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North China (north + china)
Terms modified by North China Selected AbstractsTHE INDIVIDUAL AND TRANSFORMATION OF BRIDEWEALTH IN RURAL NORTH CHINATHE JOURNAL OF THE ROYAL ANTHROPOLOGICAL INSTITUTE, Issue 4 2005Yunxiang Yan Drawing on data collected from longitudinal fieldwork, this article explores how the practice of bridewealth in a north China village has been transformed into a new form of property division within the groom's family and how the bride has replaced her parents as the recipient of bridewealth. At the individual level, this transformation has evolved through a long process during which individual brides and grooms negotiated with their parents over control of bridewealth. A misunderstanding about Western individualism provides village youths with a new ideological tool to justify their relentless extraction of money from their parents. At the level of family life, the changing norm of bridewealth has shaped and in turn has helped to re-shape mate choice, family division, and support for the elderly. These family changes occurred within the context of other social changes at the macro level and are closely linked to the role of the powerful state. While emphasizing the active role of the individual in transforming the practice of bridewealth, an important phenomenon that by and large has been overlooked in most studies of marriage transactions, the article also examines the specific strategies by which individuals exercise their agency, choosing to take advantage of the custom of bridewealth instead of abandoning it when it affords them greater autonomy in mate choice and marriage negotiations. [source] Magnetostratigraphic constraints on the Gondwanan origin of North China: Cambrian/Ordovician boundary resultsGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 1 2002Zhenyu Yang Summary A significant gap in the middle Palaeozoic apparent polar wander (APW) path precludes polarity definition of the early Palaeozoic palaeopole for North China. This problem can in part be resolved by the intercontinental correlation of magnetic polarity patterns across small time intervals. A magnetostratigraphic study was carried out on upper Cambrian to lower Ordovician sediments near Zhaogezhuang (long. 118.5°E, lat. 39.7°N), North China. After stepwise thermal or thermal and alternating field demagnetizations, a characteristic magnetic component with normal and antipodal reversed directions was identified. These data, drawn from 49 samples, yield a north palaeopole at long. 294.6°E, lat. 32.9°N (dp = 3.0°, dm = 5.3°). A concordant magnetic polarity pattern around the Cambrian,Ordovician boundary and lowest Ordovician obtained from different continents favours a Southern Hemisphere origin (,17°) formation site. Using the Cambrian,Ordovician APW paths between North China and Gondwana, we suggest that the North China block (NCB) was part of Gondwana during the Cambro,lowest Ordovician, and started breaking away from Gondwana in the lower Ordovician. This finding is contrary to some palaeomagnetic models where the NCB was quite separate from Gondwana in the late Proterozoic, and was attached to the ,Pacific' side of Antarctica. [source] Evaluation of coalbed methane reservoirs from geophysical log data using an improved fuzzy comprehensive decision method and a homologous neural networkGEOPHYSICAL PROSPECTING, Issue 5 2002J. Hou The evaluation of coalbed methane reservoirs using log data is an important approach in the exploration and development of coalbed methane reservoirs. Most commonly, regression techniques, fuzzy recognition and neural networks have been used to evaluate coalbed methane reservoirs. It is known that a coalbed is an unusual reservoir. There are many difficulties in using regression methods and empirical qualitative recognition to evaluate a coalbed, but fuzzy recognition, such as the fuzzy comprehensive decision method, and neural networks, such as the back-propagation (BP) network, are widely used. However, there are no effective methods for computing weights for the fuzzy comprehensive decision method, and the BP algorithm is a local optimization algorithm, easily trapped in local minima, which significantly affect the results. In this paper, the recognition method for coal formations is developed; the improved fuzzy comprehensive decision method, which uses an optimization approach for computing weighted coefficients, is developed for the qualitative recognition of coalbed methane reservoirs. The homologous neural network, using a homologous learning algorithm, which is a global search optimization, is presented for the quantitative analysis of parameters for coalbed methane reservoirs. The applied procedures for these methods and some problems related to their application are also discussed. Verification of the above methods is made using log data from the coalbed methane testing area in North China. The effectiveness of the methods is demonstrated by the analysis of results for real log data. [source] Demographic variation and biomass allocation of Agropyron cristatum grown on steppe and dune sites in the Hunshandake Desert, North ChinaGRASS & FORAGE SCIENCE, Issue 1 2005R. Z. Wang Abstract Demographic and biomass allocation patterns of Agropyron cristatum were measured on steppe and dune sites in the Hunshandake desert of North China in 2001 and 2002. Total plant population, reproductive shoot densities and its differentiation rates were significantly higher in the steppe sites in both years. Plant heights for both vegetative and reproductive shoots were greater in the year with the higher rainfall. The dune sites had a higher biomass allocation to vegetative shoots and roots, while the steppe sites had a higher biomass allocation to reproductive shoots and seed production. It is suggested that the population demography and biomass allocation of the species responded to the differences in the soil variables in the steppe and dune sites. [source] Water crises and hydrology in North ChinaHYDROLOGICAL PROCESSES, Issue 12 2004Changming Liu No abstract is available for this article. [source] Water problems and hydrological research in the Yellow River and the Huai and Hai River basins of ChinaHYDROLOGICAL PROCESSES, Issue 12 2004Changming Liu Abstract This paper deals with hydrological research in regard to the water resources crisis in the vulnerable areas found in the northern part of China. This area includes three main river basins, namely the basins of the Yellow (Huang) River, the Hai River and the Huai River. Several water problems are becoming very severe. Among them, two are the most critical: the Yellow River has been drained dry in the main course of its lower reaches and along its major tributaries, and the groundwater table has rapidly declined in the floodplains of the three rivers' downstream areas. To counter the problems, particularly the critical issues mentioned above, hydrological research, which serves as the basis of water development and management, has been carried out in the last two decades. This paper addresses three basic scientific problems in North China, namely: (a) water consumption and the capacity for saving water; (b) the changes in hydrological processes and water resources caused by natural change and human activities; and (c) the ability to supply water resources and water safety in terms of both quantity and quality within a changing environment. However, opportunities and challenges for ameliorating the problems exist, and new ideas and methodology to solve the problems have been proposed, such as the interface process study on the interactions in the soil,root interface, the plant,atmosphere interface, the soil,atmosphere interface, and the interface of soil water and groundwater. In order to manage water resources in a sustainable manner, the study of water resources' renewal ability as affected by natural change and human activity is addressed from the viewpoint of both water quantity and quality, and their integration. To reduce the vulnerability of water resources in regional water management, a paradigm of sustainable water resources utilization is also proposed, using water,heat balance, water,salt balance, water,sediment balance, and water supply,demand balance. This approach may help reveal the basic problems and point to possible approaches to solving the water problems in North China in the 21st century. Copyright © 2004 John Wiley & Sons, Ltd. [source] Tectonic and stratigraphic significance of the Middle Ordovician carbonate breccias in the Ogcheon Belt, South KoreaISLAND ARC, Issue 3 2002In-Chang Ryu Abstract Carbonate breccias occur sporadically in the Lower,Middle Ordovician Maggol Limestone exposed in the Taebacksan Basin in the northeastern part of the northeast,southwest-trending Ogcheon Belt, South Korea. These carbonate breccias have been previously interpreted as intraformational or fault-related breccias. Thus, little attention has been focused on tectonic and stratigraphic significance of these carbonate breccias. The present study, however, indicates that the majority of these carbonate breccias are solution,collapse breccias, which are causally linked to paleokarstification. Carbonate facies analysis in conjunction with conodont biostratigraphy suggests that an overall regression toward the top of the Maggol Limestone probably culminated in subaerial exposure of platform carbonates during the early Middle Ordovician (earliest Darriwilian). Extensive subaerial exposure of platform carbonates resulted in paleokarst-related solution,collapse breccias in the upper Maggol Limestone. This subaerial exposure event is manifested as a major paleokarst unconformity at the Sauk,Tippecanoe sequence boundary elsewhere beneath the Middle Ordovician succession and its equivalents, most notably North America and North China. Due to its global extent, this paleokarst unconformity has been viewed as a product of second- or third-order eustatic sealevel drop during the early Middle Ordovician. Although a paleokarst breccia zone is recognized beneath the Middle Ordovician succession in South Korea, the Sauk,Tippecanoe sequence boundary appears to be a conformable transgressive surface on the top of the paleokarst breccia zone in the upper Maggol Limestone. The paleokarst breccia zone beneath the conformable transgressive surface is represented by a thinning-upward stack of exposure-capped tidal flat-dominated cycles that are closely associated with multiple occurrences of paleokarst-related solution,collapse breccias. This paleokarst breccia zone was a likely consequence of repeated fourth- and fifth-order sealevel fluctuations. It suggests that second- and third-order eustatic sealevel drop may have been significantly tempered by substantial tectonic subsidence near the end of the Maggol deposition. The tectonic subsidence in the basin is also evidenced by the occurrence of coeval off-platform lowstand siliciclastic quartzite lenses as well as debris flow carbonate breccias (i.e. the Yemi Breccia). With the continued tectonic subsidence, subsequent rise in the eustatic cycle caused drowning and deep flooding of carbonate platform, forming a transgressive surface on the top of the paleokarst breccia zone. This tectonic implication contrasts notably with the slowly subsiding carbonate platform model for the basin as has been previously interpreted. Thus, it is proposed that the Taebacksan Basin in the northeastern part of the Ogcheon Belt evolved from a slowly subsiding carbonate platform to a rapidly subsiding intracontinental rift basin during the early Middle Ordovician. The proposed tectonic model in the basin gives much better insight to unravel the stratigraphic response to tectonic evolution of the Ogcheon Belt, which remains an enigmatic feature in formulating a tectonic framework of the Korean peninsula. The present study also provides a good example that the falling part of the eustatic sealevel cycle may not produce a significant event in a rapidly subsiding basin where the rate of eustatic fall always remained lower than the rate of subsidence. [source] Effect of Seasonality on Distribution of Macroalgae in a Stream System (Xin'an Spring) in Shanxi Province, North ChinaJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 8 2006Bian-Fang Hu Abstract A survey of the seasonal distribution of macroalgae in a stream system in Shanxi Province, north China, was undertaken from July 2004 to April 2005. The relative abundance and percentage cover of macroalgae, and several environmental factors were monitored along a 20-m stretch at each of four sites, at intervals of approximately three months (one sampling per season). Several stream conditions were relatively constant over the sampling period (pH, maximum width and maximum depth), whereas others exhibited a distinct seasonal pattern (water temperature and specific conductance), and some fluctuated with no discernable seasonal pattern (current velocity and dissolved oxygen). Forty-two species of macroalgae were found, with a predominance of Chlorophyta (26 species, 61.9%). Rhodophyta and Charophyta represented the smallest proportion (1 species each, 2.38%). Six macroalgae species were the most widespread, occurring in all four sampling sites. Twelve species were found at only one site each. In terms of seasonality, eight species occurred throughout the year, whereas 16 species were found in only one season each. The macroalgal community at Xin'an Spring was species rich relative to other streams. Species richness per sampling site was negatively correlated with pH. Principal component analysis revealed that no single variable had much influence on the macroalgal seasonal dynamics. We calculated Sorensen similarity indices to compare our study with other continent-wide surveys of stream macroalgae, but the similarity indices were all very low. This study also shows that macroalgae in different locations have significant reproductive isolation. (Managing editor: Ya-Qin Han) [source] Micro-structural characterization of red decorations of red and green color porcelain (Honglvcai) in ChinaJOURNAL OF RAMAN SPECTROSCOPY, Issue 8 2009Lihua Wang Abstract Red and green color porcelain (Honglvcai) is an important type of polychrome porcelains invented in North China during Song and Jin Dynasties. One of its great successes is its red decoration painted on the surface of glaze and fired at low temperature. Raman spectroscopy and X-ray absorption fine structure (XAFS) at Fe K-edge, were used to characterize the microstructure of red decorations from Song and Jin Dynasties to Ming Dynasty. The analyzing results on eight samples showed that hematite (,-Fe2O3) was the main chromogenic substance in red decorations from different dynasties, which indicated a similar technological skill among the investigated samples. The oxidation state of iron in red decorations was determined to be mainly trivalent, indicating that red decorations were fired under oxidizing atmosphere. Besides, it was found that the hematite (,-Fe2O3) in red decorations had a distorted structure, which was presumed to be an important factor influencing the color of red decorations. Copyright © 2009 John Wiley & Sons, Ltd. [source] The Role of Climate and Human Influences in the Dry-Up of the Jinci Springs, China,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 5 2009Yonghong Hao Abstract:, One of the largest karst springs in North China, the Jinci Springs, dried up and has remained dry since 1994. We develop a correlation analysis with time-lag and a regression analysis with time-lag to study the relation between spring flow and precipitation. This allows us to obtain a better understanding of karst hydrological processes by differentiating the contribution of variation in precipitation from anthropogenic impacts on the dry-up of Jinci Springs. We divided the karstic hydrological processes into two phases: pre-1961 and post-1961. In the first phase (i.e., 1954-1960) the groundwater recharge was affected by precipitation alone, and in the second phase (i.e., 1961-1994) the groundwater recharge was influenced by both precipitation and human activities. Using precipitation and groundwater recharge data in the first phase, we set up a groundwater recharge model with time-lags. By running the time-lags model, we acquired the groundwater recharge likely to occur under the sole effect of precipitation in the second phase. Using a water-balance calculation, we conclude that the groundwater recharge exhibited statistical stationarity, and the Jinci Springs dry-up was the result of anthropogenic activities. At least three specific types of anthropogenic activities contributed to the drying-up of Jinci Springs: (1) groundwater pumping accounts for 51%, (2) the dewatering from coal mining accounts for 33%, (3) and dam-building 14%. The drying-up of Jinci Springs meant that the groundwater drained from the aquifer's fractures, and subsequently changed the structure of the karst aquifer. Although groundwater exploitation has been reduced, the flow at Jinci Springs has not reoccurred. [source] Spatial patterns and associations in a Quercus-Betula forest in northern ChinaJOURNAL OF VEGETATION SCIENCE, Issue 3 2004J.H. Hou Abstract: Question: Are species-specific regeneration strategies and competition the dominant processes facilitating species coexistence in a Quercus liaotungensis dominated temperate deciduous forest? Location: Dongling Mountains, North China, 1300 m a.s.l. Methods: Ripley's K -function was used to characterize the spatial patterns and spatial associations of two dominant tree species, Quercus liaotungensis and Betula dahurica, and a common subcanopy species, Acer mono, at different growth stages (adult, sapling, seedling). Results: Seedlings, saplings and adults of all three species exhibited clumped distributions at most spatial scales. Quercus seedlings and saplings were positively associated with conspecific adult trees and spatially independent of dead trees suggesting that seed dispersal and vegetative regeneration influenced the spatial patterning of Quercus trees. Betula seedlings and saplings were positively associated with both live and dead trees of conspecific adults at small scales (<5 m) but negatively associated with live and dead trees of other species indicating sprouting as an important mechanism of reproduction. Saplings of Acer had a strong spatial dependence on the distribution of conspecific adult trees indicating its limited seed dispersal range. Negative associations between adult trees of Betula and Quercus demonstrated interspecific competition at local scales (<5 m). Conclusions: Different regeneration strategies among the three species play an important role in regulating their spatial distribution patterns, while competition between individuals of Betula and Quercus at the adult stage also contributes to spatial patterning of these communities. The recruitment limitations of Betula and Quercus may affect the persistence of these species and the long-term dynamics of the forest. [source] Geo,tectonic Position of Tin Polymetallic Mineralization Zone in the Southern Da Hinggan Mountains Area, Inner Mongolia, China: An Introduction to This Special IssueRESOURCE GEOLOGY, Issue 4 2001Shihua SUN Abstract: As a part of the main activities of Japan-China technical cooperation project, a test survey area, approximately 5,000 km2, was established for the implement of its geological and geochemical research program. A major mineralization zone called Huanggang,Ganzhuermiao,Wulanhaote Sn-Cu polymetallic mineralization zone is recognized in the southern Da Hinggan Mountains area. The southern half of this zone is known as the sole Sn-mineralization zone in North China. The survey area lies in this prominent zone. As the most of the papers presented in this issue have concerns to the geology and mineralization in this survey area, this report was prepared to introduce geo-tectonic situation of the Sn-Cu polymetallic mineralization zone in the Inner Mongolia orogenic belt. The belt is divided into four tectonic facies (from NW to SE); I: Wuliyasitai volcano-plutonic zone, II: Hegenshan ophiolite mélange zone, III: Sunitezuoqi volcano-plutonic zone, IV: Wenduermiao ophiolite mélange zone. The subject Sn-Cu polymetallic mineralization zone is situated in the southeastern part of the Sunitezuoqi magmatic zone. About this Sunitezuoqi magmatic zone, three geo-tectonic characteristics are pointed out. In late Carboniferous to early Permian period, subduction of Hegenshan oceanic crust occurred, which accelerated volcano-plutonic activities and brought about basic to intermediate volcanic rocks of tholeiitic to calc-alkaline series represented by Dashizhai Group in the Sunitezuoqi magmatic zone. Late Jurassic to early Cretaceous acidic rocks representing the most culminated volcanism and plutonism in Mesozoic era in the Da Hinggan Moutains area are distributed very extensively in and around the Sn-Cu polymetallic mineralization zone. The Proterozoic metamorphic basement rocks called Xilinhaote complex are distributed close to the mineralized area in the Sunitezuoqi magmatic zone. Although the real mineralization was known associated with Mesozoic acidic to intermediate volcano-plutonic activities, it is thought that the lower Permian Dashizhai volcanic rocks and pre-Cambrian basement rocks might have played certain significant role in the process respectively of extraction of elements and formation of the magma favorable for such mineralization in the Sunitezuoqi magmatic zone. It would be necessary to give further considerations to these three geological units in relation to the Sn-Cu polymetallic mineralization. [source] Taxonomic Characterization of Two Marine Peritrichous Ciliates, Pseudovorticella clampi n. sp. and Zoothamnium pararbuscula n. sp. (Ciliophora: Peritrichia), from North ChinaTHE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 2 2005DAODE JI Abstract. The morphology, infraciliature, and silverline system of two new peritrichous ciliates, Pseudovorticella clampi n. sp. and Zoothamnium pararbuscula n. sp., have been investigated based on both living and silver-impregnated specimens. Partial sequence of 18S-ITS1-5.8S rDNA of Z. pararbuscula is also determined in order to compare it with the closely related congener, Zoothamnium arbuscula. Zoothamnium pararbuscula can be distinguished from its close form Z. arbuscula by the different habitats, the appearance of the main stalk, the position of the contractile vacuole, and the information derived from 18S-ITS1-5.8S rDNA sequence analysis. Pseudovorticella clampi n. sp. is distinguished from its congeners by its body shape and size, pellicle granules, habitat, and number of transverse silverlines. [source] Late Carboniferous-Early Permian Sequence Stratigraphy and Depositional Evolution in the Northeast Ordos Basin, North ChinaACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 5 2010YANG Minghui Abstract: Sequence stratigraphical analysis was applied to the Upper Carboniferous-Lower Permian sedimentary succession of the northeastern Ordos Basin, north China based on data acquired from ten entire logging curves and eight outcrops. The facies framework of the lithostratigraphical unit, the Taiyuan Formation comprises seven facies in two facies associations, varying from fluvio-delta to shelf-barrier islands. The facies are presented within a chronostratigraphical framework, linked by systems tract, which in turn are limited by flooding surfaces and sequence boundaries. Six third-order depositional sequences are recognised, bounded by six type 2 unconformities. An upwards-shallowing epicontinental sea sedimentary model is created, which consists of a sandstone, coal seam and carbonate succession. [source] Sedimentary Features and Their Implications of Microdigital Stromatolites from the Mesoproterozoic Wumishan Formation at the Jixian Section in North ChinaACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 3 2010Mingxiang MEI Abstract: The Mesoproterozoic Wumishan Formation at the Jixian section in Tianjin is a set of more than 3000-m-thick stromatolitic carbonate succession. In this succession, several lithofacies units, that is, the subtidal stromatolitic biostrome, the thrombolitic bioherm, tidal-flat micritic dolomite and lagoon dolomitic shale, make up many meter-scale cycles of the peritidal carbonate type that have been nominated as the Wumishan cycles. Importantly, many microdigital stromatolites make up the stromatolitic biostrome unit of the Wumishan cycles in the lower part of the Wumishan Formation. These microdigital stromatolites have been grouped as a stromatolitic assemblage by paleontologists, that is, "Pseudogymnosolen mopanyuensis-Scuphus-Yangzhuang columnaris" assemblage. These microdigital stromatolites had also been interpreted as the aragonite (tufa) sea-floor precipitates by sedimentologists, and has further been thought as the special products of the transitional period from the sea-floor aragonite precipitates of the Archean to the clastic and muddy carbonates of the Neoproterozoic. Although there are some restrictions for the stratigraphic meaning of the concept of the stromatolitic assemblage, detailed studies on classification by paleontologists provide an important clue to understand the sedimentological meaning of the microdigital stromatolites. Furthermore, an important and obvious horizon for the end of the microdigital stromatolites was recorded in the Mesoproterozoic Wumishan Formation at the Jixian section, which provides useful information to understand the stromatolite decline occurred at c.1250 Ma and the evolving carbonate world of the Precambrian. [source] Late Cenozoic Geomorphology, Geochronology and Physiography of Yuntaishan in Southern Taihang Mountain, North ChinaACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 1 2010Zhonghai WU Abstract: The late Cenozoic geomorphic features and geochronologic data of the Zhingfang River catchment in the Yuntaishan World Geopark are studied. Several quarternary geochronologic methods, including electron spin resonance (ESR), optically stimulated luminescence (OSL), thermo-luminescence (TL) and U-series are presented in this paper. The results suggest that there are two planation surfaces, named as the Taihang surface which is a peneplain of Taihang stage formed during Oligocene or Oligocene to early-middle Miocene period, and Tang-hien surface which is a mature wide valley of Tang-hien stage formed during late Miocene-Pliocene or Pliocene-early Pleistocene period and probably ended prior to 2.2,2.6 Ma based on ESR dating. After the Tang-hien stage, the incision and aggradation of the river formed six stream terraces with heights of 3,5 m, 8,12 m, 22,24 m, 28,38 m, 50,62 m and 80,85 m above the river bottom, respectively. The dating results of the alluvium sediments suggest that these terraces were formed during Holocene, 20,23 ka B.P., 110,120 ka B.P., 200,240 ka B.P., 840,1200 ka B.P. or ,450 ka B.P. and 1600,1800 ka B.P. or ,1100 ka B.P., respectively. These results indicate that episodic incision of the river, which controls the formation of the scenery in the Yuntaishan World Geopark, was mainly influenced by the periodic dry-wet climate change during late Cenozoic mountain uplift. [source] Reclassification of the Meso- and Neoproterozoic Chronostratigraphy of North China by SHRIMP Zircon AgesACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 6 2009GAO Linzhi Abstract: High-quality zircon U-Pb ages acquired from Meso- and Neoproterozoic strata in North China in recent years has provided a high-resolution chronostratigraphic framework for dating. A basis of this high-level chronostratigraphic system provides the foundation for a global Precambrian study and stratigraphic correlation and so recent geological studies have focused attention on systemic SHRIMP zircon dating. A chronology of Meso- and Neoproterozoic strata and the time of origin of the overlying Changcheng System is given on the basis of new SHRIMP zircon dating from the Qianxi Complex and diabase of the Chuanlinggou Formation. A new tectonostratigraphy for a Neoproterozoic chronostratigraphic framework in the southeastern margin of the North China continent is underpinned by the new SHRIMP zircon dating of a Neoproterozoic mafic magma diabase in the Jiao-Liao-Xu-Huai Sub-Province. [source] Temporal Distribution of Diagnostic Biofabrics in the Lower and Middle Ordovician in North China: Clues to the Geobiology of the Great Ordovician Biodiversification EventACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 3 2009Jianbo LIU Abstract: The temporal distribution of the diagnostic biofabrics in the Lower and Middle Ordovician in North China distinctly illustrates that the sedimentary systems on the paleoplate have been changed markedly as consequences of the Great Ordovician Biodiversification Event (GOBE). The pre-GOBE sedimentary systems deposited in Tremadoc display widespread microbialite and flat-pebble conglomerates, and a less extent of bioturbation. Through the transitional period of early Floian, the sedimentary systems in the rest of the Early and Mid- Ordovician change to GOBE type and are characterized by intensive bioturbation and vanishing flat-pebble conglomerates and subtidal microbial sediments. The irreversible changes in sedimentary systems in North China are linked to the GOBE, which conduced the increase in infaunal tiering, the expansion of infaunal ecospace, and the appearance of new burrowers related to the development of the Paleozoic Evolutionary Fauna during the Ordovician biodiversification. Thus, changes in sedimentary systems during the pivotal period of the GOBE were consequences of a steep diversification of benthic faunas rather than the GOBE's environmental background. [source] Coalbed Methane-bearing Characteristics and Reservoir Physical Properties of Principal Target Areas in North ChinaACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 3 2004TANG Shuheng Abstract, The coalbed methane (CBM) resources in North China amounts up to 60% of total resources in China. North China is the most important CBM accumulation area in China. The coal beds of the Upper Paleozoic Taiyuan and Shanxi formations have a stable distribution. The coal reservoir of target areas such as Jincheng, Yanquan-Shouyang, Hancheng, Liulin, etc. have good CBM-bearing characteristics, high permeability and appropriate reservoir pressure, and these areas are the preferred target areas of CBM developing in China. The coal reservoirs of Wupu, Sanjiaobei, Lu'an, Xinmi, Anyang-Hebi, Jiaozuo, Xinggong and Huainan also have as good CBM-bearing characteristics, but the physical properties of coal reservoirs vary observably. So, further work should be taken to search for districts with high pressure, high permeability and good CBM-bearing characteristics. Crustal stresses have severe influence on the permeability of coal reservoirs in North China. From west to east, the crustal stress gradient increases, while the coal reservoirs permeability decreases. [source] Conodonts from the Upper Cambrian Sesong and Hwajeol Formations in the Sabuk Area, South KoreaACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 2 2002LEE Byung-Su Abstract, This paper presents a conodont biostratigraphic study on the Upper Cambrian Sesong and Hwajeol Formations in the Sabuk area, Korea. Two samples near the base of the Sesong Slate at the Pukil section contain lower Upper Cambrian conodonts, comprising Furnishina furnishi, F. kranzae, F. pernical?, F. triangulata, Hertzina elongata, Laiwugnathus doidyxus?, Phakelodus elongatus, Muellerodus? obliquus, Westergaardodina matsushitai and W. moessebergensis. This is the first conodont record of the Upper Cambrian formations recovered yet in the northern limb of the Paekunsan syncline. The faunal assemblage is correlatable with the lower Upper Cambrian W. matsushitai Zone of North China. Four local biozones are recognized in the Hwajeol Formation, i.e. the Proconodontus, Eoconodontus notchpeakensis, Cambrooistodus minutus and Cordylodus proavus Zones in ascending order. This zonal scheme is essentially equivalent to that of the southern limb of the Paekunsan syncline and they are correlatable with zones in other parts of the world, including North America, Australia, Iran and China. [source] Property rights, labour markets, and efficiency in a transition economy: the case of rural ChinaCANADIAN JOURNAL OF ECONOMICS, Issue 4 2002Dwayne Benjamin We investigate the consequences of imperfect factor market development for farm efficiency in North China. We estimate the extent to which an inverse relationship in farm productivity can be attributed to the administrative (as opposed to market) allocation of land, combined with unevenly developed off,farm opportunities. Using a new household survey, we find considerable inefficiency in the use of labour. This inefficiency is alleviated by external labour markets and, to a limited degree, by administrative reallocations. The reallocations do not go far enough, however, which raises important questions about constraints on rental activity and property rights formation more generally. JEL Classification: Q15, O12 Droits de propriété, marchés du travail et efficacité dans une économie en transition : le cas de la Chine rurale. Ce mémoire analyse les conséquences du développement de marchés imparfaits des facteurs de production sur l'efficacité des fermes dans le nord de la Chine. On examine jusqu'à quel point la relation inverse entre la productivité des fermes et leur taille est attribuable à l'allocation administrative de la terre (par opposition à l'allocation par le marché), en combinaison avec le développement inégal des opportunités en dehors de la ferme. Les auteurs utilisent une nouvelle enquête sur les ménages qui révèle une grande inefficacité dans l'utilisation du travail. Cette inefficacité est atténuée par des marchés de travail externes, et, à un moindre degré, par des ré,allocations administratives. Les ré,allocations ne vont pas assez loin cependant. Voilà qui soulève des questions importantes à propos des contraintes sur les activités de location et la formation des droits de propriété en général. [source] A Rb/Sr record of catchment weathering response to Holocene climate change in Inner MongoliaEARTH SURFACE PROCESSES AND LANDFORMS, Issue 3 2006Zhangdong Jin Abstract Variation in the rubidium to strontium (Rb/Sr) ratio of the loess,palaeosol sequences has been proposed to reflect the degree of pedogenesis and weathering in the northwestern region of China. To characterize the Rb/Sr ratio of the dissolved loads of a single catchment, we analysed a 12·08 m sediment core from Daihai Lake in Inner Mongolia, north China. Dating control was provided by 210Pb, 137Cs and AMS- 14C. Sequential extraction experiments were conducted to investigate the concentrations of Rb and Sr on various chemical fractions in the lake sediments. Down-core variation in the Rb/Sr ratios provides a record of Holocene weathering history. From 9 to 3·5 ka bp, accelerated chemical weathering was experienced throughout the Daihai catchment under mainly warm and humid conditions, and this reached a maximum at c. 5 ka bp. However, weathering was reduced between c. 8·25 and 7·90 ka bp, which may reflect the global 8·2 ka cooling event. After c. 2·5 ka bp, increased Rb/Sr ratios with higher frequency of fluctuations indicate reduced weathering within the Daihai catchment. The highest Rb/Sr ratios in the Little Ice Age lake sediments indicate the weakest phase of Holocene chemical weathering, resulting from a marked reduction in Sr flux into the basin. The Rb/Sr record also shows an enhancement of chemical weathering under today's climate, but its intensity is less than that of the Medieval Warm Period. Increased Rb/Sr in lake sediment corresponding to reduced catchment weathering is in striking contrast to Rb/Sr decrease in the glacial loess layers in the loess,palaeosol sequence. Copyright © 2005 John Wiley & Sons, Ltd. [source] The origins of food production in north China: A different kind of agricultural revolution,EVOLUTIONARY ANTHROPOLOGY, Issue 1 2010Robert L. Bettinger Abstract By roughly 8,000 calendar years before the present (calBP), hunter-gatherers across a broad swath of north China had begun small-scale farming of broomcorn millet (Panicum miliaceum) and foxtail millet (Setaria italica).1,6 According to traditional wisdom, this early millet farming evolved from the intensive hunter-gatherer adaptation represented by the late Pleistocene microblade tradition of northern China,2, 7 termed here the North China Microlithic. The archeological record of this hunter-gatherer connection is poorly documented, however, and as a result the early agricultural revolution in north China is not as well understood as those that occurred in other parts of the world. The Laoguantai site of Dadiwan, in the western Loess Plateau, Gansu Province, PRC, furnishes the first complete record of this transition, which unfolded quite differently from other, better known, agricultural revolutions. [source] Using an airgun array in a land reservoir as the seismic source for seismotectonic studies in northern China: experiments and preliminary resultsGEOPHYSICAL PROSPECTING, Issue 4 2008Yong Chen ABSTRACT This paper reports the field setup and preliminary results of experiments utilizing an airgun array in a reservoir in north China for a seismotectonic study. Commonly used in offshore petroleum resource exploration, the airgun source was found to be more useful than a traditional explosive source for large-scale and long offset land seismic surveys. The airgun array, formed by four 1,500 in3 airguns (a total of 6,000 in3 in volume) was placed at a depth of 6,9 m into the reservoir to generate the pressure impulse. No direct evidence was found that the airgun source adversely affected the fish in the reservoir. The peak ground acceleration recorded on the top of the reservoir dam 100 m away was 17.8 gal in the horizontal direction; this is much less than the designed earthquake-resistance threshold of 125 gal for this dam. The energy for one shot of this airgun array is about 6.68 MJ, equivalent to firing a 1.7 kg explosive. The seismic waves generated by the airgun source were recorded by receivers of the regional seismic networks and a temporary wide-angle reflection and refraction profile formed by 100 short-period seismometers with the maximum source-receiver offset of 206 km. The seismic wave signature at these long-offset stations is equivalent to that generated by a traditional blast source in a borehole with a 1,000,2,000 kg explosive. Preliminary results showed clear seismic phases from refractions from the multi-layer crustal structures in the north China region. Forward modelling using numerical simulation confirms that the seismic arrivals are indeed from lower crustal interfaces. The airgun source is efficient, economical, environmentally friendly and suitable for being used in urbanized areas. It has many advantages over an explosive source for seismotectonic studies such as the high repeatability that is supreme for stacking to improve signal qualities. The disadvantage is that the source is limited to existing lakes or reservoirs, which may restrict experimental geometry. [source] Water fluxes at a fluctuating water table and groundwater contributions to wheat water use in the lower Yellow River flood plain, ChinaHYDROLOGICAL PROCESSES, Issue 6 2007Jianfeng Yang Abstract Capillary upflow from and deep percolation to a water table may be important in crop water supply in irrigated areas of the lower Yellow River flood plain, north China. These fluxes at the water table and the variations of the capillary upflow in relation to crop evapotranspiration need to be investigated to quantify the effect of a water table on soil water balance and to improve agricultural water management. A large weighing lysimeter was used to determine daily crop evapotranspiration, daily capillary upflow from and daily percolation to a fluctuating water table during a rotation period with wheat growing in a dry season and maize in a rainy season. The water table depth varied in the range 0·7,2·3 m during the maize growth period and 1·6,2·4 m during the wheat growth period. Experimental results showed that the capillary upflow and the percolation were significant components of the soil water balance. Three distinctly different phases for the water fluxes at the water table were observed through the rotation period: water downward period, the period of no or small water fluxes, and water upward period. It implied that the temporal pattern of these water fluxes at the water table was intimately associated with the temporal distribution of rainfall through the rotation period. An empirical equation was determined to estimate the capillary upflow in relation to wheat evapotranspiration and root zone soil water content for local irrigation scheduling. Coupled with the FAO-Penman,Monteith equation, the equation offers a fast and low cost solution to assess the effect of capillary upflow from a water table on wheat water use. Copyright © 2007 John Wiley & Sons, Ltd. [source] Features of cross-Pacific climate shown in the variability of China and US precipitationINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 13 2005Q. Li Abstract In this study, we have analyzed the climate features of China and the United States with a focus on the differences, similarities, connectivity, and predictability of precipitation and the relationships between precipitation and large-scale patterns of natural variability. China precipitation is characterized by large seasonality, with a maximum in summer and a minimum in winter. The seasonality of precipitation shows an increasing linear tendency in northwest China, with a change of about 20% from 1901 to 1998. A relatively weaker increasing tendency also appears in the Big Bend of Yellow River (BBYR) and the Tibetan Plateau, while southwest China experiences a decreasing tendency. Furthermore, the seasonality in the BBYR shows particularly significant interdecadal variability, while that of southern and eastern China has decreased slightly in the recent decades. Compared to China, the United States as a whole has less precipitation in summer but more precipitation in other seasons. Here, the seasonality of precipitation is only about 24% of that in China. The annual mean precipitation is 64.1 mm per month in the United States, compared to 54.6 mm per month in China. The seasonality of precipitation exhibits a decreasing tendency in the southeast, Pacific Northwest, and Gulf Coast and an increasing tendency in the Great Lakes. The seasonality in the Great Plains exhibits large interdecadal variability. The long-term variations of precipitation are highly seasonally dependent. In summer, a decreasing trend is observed in north China and an increasing trend is found in eastern-central China. However, these trends are almost opposite in spring. In addition, the fall precipitation decreases with time nearly everywhere in China except for the middle and lower reaches of the Yangtze River Valley. Results also indicate that the El Niño/Southern Oscillation (ENSO), the Arctic Oscillation (AO), the North Atlantic Oscillation (NAO), the Pacific Decadal Oscillation (PDO), and the North Pacific (NP) fluctuation affect strongly the variations of China and US precipitation. Although these influences vary with regions and seasons, we in particular emphasize the importance of AO and NAO for China precipitation and NP and PDO for US precipitation. In fall, ENSO and PDO are the two phenomena that influence predominantly precipitation variability in both China and the United States We also identify the common phenomena that influence China and US regional precipitation and provide a better understanding of the physical mechanism for precipitation variability through the associated changes in atmospheric and oceanic conditions. Furthermore, we develop a linear regression model, based on multiple regression method by combining the regionally and seasonally varying impacts, to increase the skill of precipitation prediction. Copyright © 2005 Royal Meteorological Society [source] K- and Si-rich glasses in harzburgite from Damaping, north ChinaISLAND ARC, Issue 4 2008Yongfeng Zhu Abstract A study of potassium- and silica-rich glass (SiO2 = 65.3,67.4%, K2O = 7.1,9.8%, Na2O = 4.4,6.5%) in spongy clinopyroxene rims from anhydrous spinel harzburgite, collected from Damaping (Hannuoba, north China), is reported here. The corroded surface of clinopyroxene along with clear chemical zonation (homogeneous core and partially melted rim) suggests that incongruent melting of primary clinopyroxene is responsible for generating the Si-rich glass in clinopyroxene rims. The degree of clinopyroxene melting is estimated to be higher than 15%. In order to generate glass with K2O contents of 7.0 to 9.8% by clinopyroxene melting at a degree of 15% in a closed system, K2O contents in the primary clinopyroxene should be greater than 1.0 wt%, suggesting a very deep origin for the Damaping harzburgite. [source] Plant species as indicators of the extent of desertification in four sandy rangelandsAFRICAN JOURNAL OF ECOLOGY, Issue 1 2007Ping An Abstract We examined the distribution of plants in sandy rangelands with different degrees of desertification in (i) Horqin and Mu Us sandy lands in north China, (ii) Darfur district in north-west Sudan and (iii) southern Tunisia. The severity of desertification in these areas was classified as light, moderate, severe or extreme. The following vegetation changes were observed with increasing severity of desertification: a decrease in the number of plant species, an increase in drought-tolerant plants, a decrease in the proportion of palatable grasses and the occurrence of some species in only one category of desertification, whereas other species occurred in several categories. Plant species with unique niche requirements were identified and recommended as indicators of the degree of desertification for particular areas. We discuss the characteristics of species in areas with severe desertification and the method of using plant species as indicators of the extent of desertification. Résumé Nous avons examiné la distribution des plantes dans des régions sableuses touchées à différents degrés par la désertification 1) dans les terres sableuses de Horqin et de Mu Us, dans le nord de la Chine, 2) dans le district du Darfur, au nord-ouest du Soudan et 3) dans le sud de la Tunisie. La gravité de la désertification était classifiée comme légère, modérée, sévère ou extrême. Les changements de végétation suivants ont été observés en fonction de l'accroissement de la désertification: une diminution du nombre d'espèces de plantes, une augmentation des plantes supportant la sécheresse, une diminution de la proportion de plantes appétantes, et l'occurrence de certaines espèces qui ne vivent que dans une catégorie de désertification, alors que d'autres espèces apparaissent dans plusieurs catégories. On a identifié les espèces végétales qui exigent une niche précise et on les a recommandées comme indicateurs du degré de désertification dans des zones particulières. Nous discutons des caractéristiques des espèces dans des régions où la sécheresse est sévère et de la méthode pour utiliser les espèces végétales comme indicateurs de la gravité de la désertification. [source] Effect of Seasonality on Distribution of Macroalgae in a Stream System (Xin'an Spring) in Shanxi Province, North ChinaJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 8 2006Bian-Fang Hu Abstract A survey of the seasonal distribution of macroalgae in a stream system in Shanxi Province, north China, was undertaken from July 2004 to April 2005. The relative abundance and percentage cover of macroalgae, and several environmental factors were monitored along a 20-m stretch at each of four sites, at intervals of approximately three months (one sampling per season). Several stream conditions were relatively constant over the sampling period (pH, maximum width and maximum depth), whereas others exhibited a distinct seasonal pattern (water temperature and specific conductance), and some fluctuated with no discernable seasonal pattern (current velocity and dissolved oxygen). Forty-two species of macroalgae were found, with a predominance of Chlorophyta (26 species, 61.9%). Rhodophyta and Charophyta represented the smallest proportion (1 species each, 2.38%). Six macroalgae species were the most widespread, occurring in all four sampling sites. Twelve species were found at only one site each. In terms of seasonality, eight species occurred throughout the year, whereas 16 species were found in only one season each. The macroalgal community at Xin'an Spring was species rich relative to other streams. Species richness per sampling site was negatively correlated with pH. Principal component analysis revealed that no single variable had much influence on the macroalgal seasonal dynamics. We calculated Sorensen similarity indices to compare our study with other continent-wide surveys of stream macroalgae, but the similarity indices were all very low. This study also shows that macroalgae in different locations have significant reproductive isolation. (Managing editor: Ya-Qin Han) [source] Evolution of the southern Mu US desert in north China over the past 50 years: an analysis using proxies of human activity and climate parametersLAND DEGRADATION AND DEVELOPMENT, Issue 4 2005X. Wang Abstract Many previous studies have attributed the degradation in the Mu Us Desert in China to many centuries of human activity. The present study includes analysis of proxies of human activity such as arable land area, population and livestock number, and variations of precipitation, evaporation, temperature, sand-driving wind and dust events, covering the period since 1950. It is demonstrated that desertification and vegetation rehabilitation during this period were principally related to the climatic variation, especially correlated to sand-driving winds. It also suggests that the desert evolution in the past 2000 years was controlled by climate change rather than human activity. Although human activity was significant in the desert evolution processes over the past 50 years, the impacts seems to be overestimated in previous studies. Desertification and desert evolution in the Mu Us Desert are mainly in response to climatic trends and fluctuations. Copyright © 2005 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||||||||||||||