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Structural Types (structural + type)
Selected AbstractsChamigrenelactone, a Polyoxygenated Sesquiterpene with a Novel Structural Type and Devoid of Halogen from Laurencia obtusa.CHEMINFORM, Issue 1 2005Enrique Dorta No abstract is available for this article. [source] An Analysis of Tenure and House Structure Type by Household CompositionFAMILY & CONSUMER SCIENCES RESEARCH JOURNAL, Issue 2 2007Stephanie E. Vanderford This study examined the relation of household composition and characteristics with each of two variables, tenure status and structural type of residence. Past research related to tenure status has considered household composition and characteristics in a limited manner, and very little empirical work has addressed the relations of those variables with house structure type. The three structure types assessed were manufactured housing, multifamily site-built homes, and single-family site-built homes. The authors extended past research by considering more complicated household compositions and also identified the importance of knowing more complete information about all the residents of a home to understand both tenure and house structure type. Family composition and the presence of extended family members, an unmarried partner, and other unrelated individuals all explained di ferences in tenure and house structure type. The findings suggest the significance of family and household characteristics when understanding variations in tenure and house structure type. [source] A structural proteomics filter: prediction of the quaternary structural type of hetero-oligomeric proteins on the basis of their sequencesJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 6 2007Oliviero Carugo A protein chain can correspond to a monomeric protein or it can form, together with other chains, oligomeric assemblies, which can be either homo-oligomers or hetero-oligomers. In the latter case, the three-dimensional structure of the single protein chain is unlikely to be determined, since it will probably be difficult to express and crystallize. A computational method is presented here that allows one to predict if a chain participates in hetero-oligomeric assemblies, on the basis of its amino acid composition, with accuracy close to 80%. Such a technique should improve the success rate of structural biology projects. [source] In situ X-ray diffraction analysis of iron ore sinter phasesJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 3 2004Nicola V. Y. Scarlett Owing to the depletion of world lump iron ore stocks, pre-treated agglomerates of fine ores are making up a growing proportion of blast-furnace feedstock (,80%). These agglomerations, or `sinters', are generally composed of iron oxides, ferrites (most of which are silicoferrites of calcium and aluminium, SFCAs), glasses and dicalcium silicates (C2S). SFCA is the most important bonding phase in iron ore sinter, and its composition, structural type and texture greatly affect its physical properties. Despite its prevalence and importance, the mechanism of SFCA formation is not fully understood. In situ powder X-ray diffraction investigations have been conducted into the formation of SFCA, allowing the study of the mechanism of its formation and the observation of intermediate phases with respect to time and temperature. Studies have been carried out to investigate the effects of changing the substitution levels of aluminium for iron. The use of the Rietveld method for phase quantification gives an indication of the order and comparative rates of phase formation throughout the experiments. [source] Crystal structure of the new quaternary copper manganese and zirconium chalcogenidesPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 4 2007V. P. Sachanyuk Abstract The compounds Cu2MnZrS4 and Cu2MnZrSe4 were obtained by solid-state synthesis method. It was established using an XRD powder method that they crystallize in the hexagonal structural type (space group P3m1) with unit cell parameters a = 0.37427(2) nm, c = 0.61004(3) nm (Cu2MnZrS4); a = 0.39085(2) nm, c = 0.63709(3) nm (Cu2MnZrSe4). Atomic parameters were calculated using the anisotropic approximation (RI = 0.0523 and RI = 0.0473 for Cu2MnZrS4 and Cu2MnZrSe4, respectively). (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Synthesis and characterization of some dibutylbis{5-[(E)-2-(aryl)-1-diazenyl]-2-hydroxybenzoato}tin(IV) compounds.APPLIED ORGANOMETALLIC CHEMISTRY, Issue 5 2003Toxicity studies of di-, tri-organotin complexes on the second instar of Aedes aegypti mosquito larvae Abstract The preparation and spectroscopic characterization of some complexes of the type Bu2Sn(LH)2 (LH = 5-[(E)-2-(aryl)-1-diazenyl]-2-hydroxybenzoate) are reported. On the basis of spectroscopic evidence (1H, 13C, 119Sn NMR, IR and 119mSn Mössbauer) the compounds were judged to adopt the usual dicarboxylato structural type with a skew trapezoidal arrangement. This was further confirmed by X-ray crystallography in the case of Bu2Sn(L5H)2 (L5H = 5-[(E)-2-(4-chlorophenyl)-1-diazenyl]-2-hydroxybenzoate). Toxicity studies of the di- and tri-organotin compounds on the second larval instar of Aedes aegypti mosquito larvae are reported. Copyright © 2003 John Wiley & Sons, Ltd. [source] The iron phosphate NaZnFe2(PO4)3ACTA CRYSTALLOGRAPHICA SECTION C, Issue 11 2002Mourad Hidouri Crystals of sodium zinc diiron(III) triphosphate, NaZnFe2(PO4)3, have been synthesized and structurally characterized by single-crystal X-ray diffraction. The compound features a new structural type built up from ZnO6 octahedra, FeO6 octahedra and FeO4 tetrahedra, linked together via the corners and edges of PO4 tetrahedra to form a three-dimensional framework, with tunnels running along [100]. Within these tunnels, Na+ cations occupy a highly distorted cubic site. [source] Design and Synthesis of Novel Pyrazino[2,1- a]isoquinolin Derivatives with Potent Antifungal ActivityARCHIV DER PHARMAZIE, Issue 6 2010Hui Tang Abstract A series of novel pyrazino[2,1- a]isoquinolin compounds were designed, synthesized, and their antifungal activities in vitro were evaluated. The results showed that all of the title compounds exhibited antifungal activities. Most of them exhibited stronger antifungal activities than the lead compounds; compound 7c is more potent than fluconazole against two of the three tested fungal strains. The studies presented here provide a new structural type for the development of novel antifungal agents. [source] Protein structure preference, tRNA copy number, and mRNA stem/loop contentBIOPOLYMERS, Issue 6 2004Liaofu Luo Abstract From statistical analyses of protein sequences for humans and Escherichia coli we found that the messenger RNA segment of m -codons (for m=2 to 6) with average high tRNA copy number (TCN) (larger than ,10.5 for humans or ,1.95 for E. coli) preferably code for the , helix and that with low TCN (smaller than ,7.5 for humans or ,1.7 for E. coli) preferably code for coil. Between them there is an intermediate region without correlation to structure preference. For the , strand the preference/ avoidance tendency is not obvious. All strong preference-modes of TCN for protein secondary structures have been deduced. The mutual interaction between two factors,protein secondary structural type and codon TCN,is tested by F distribution. A phenomenological model on the relation between structure preference and translational efficiency or accuracy is proposed. It is pointed out that the structure preference of codons is related to the distribution of mRNA stem/loop content in three TCN regions. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004 [source] Effect of train dynamics on seismic response of steel monorail bridges under moderate ground motionEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 10 2006Chul-Woo Kim Abstract This study is intended to investigate the seismic response of steel monorail bridges using three-dimensional dynamic response analysis. We particularly consider monorail bridge,train interaction when subjected to ground motion that occurs with high probability. A monorail train car with two bogies with pneumatic tires for running, steering and stabilizing wheels is assumed to be represented sufficiently by a discrete rigid multi-body system with 15 degrees of freedom (DOFs). Bridges are considered as an assemblage of beam elements with 6 DOFs at each node. Modal analysis is used for dynamic response analysis under moderate earthquakes. The seismic response of an advanced monorail bridge that adopts a simplified structural system and composite girders is investigated through comparison with seismic responses of a conventional bridge. The acceleration response of a monorail train is also calculated to investigate the effect of structural types of bridges on the train's dynamic response during earthquakes. Results show that the seismic responses of the advanced bridges are greater than those of the conventional monorail bridge because of the simplified structural system and increased girder weight that is attributable to composite girders of the advanced bridge. Moreover, the train on the advanced bridge shows greater dynamic response than that on the conventional bridge. Observations reveal that the dynamic monorail train system acts as a damper on the monorail bridge. That fact shows that the existing design, which considers a train as additional mass, yields a conservative result. Copyright © 2006 John Wiley & Sons, Ltd. [source] An Efficient Route to Group 6 and 8 Metallaborane Compounds: Synthesis of arachno -[Cp*Fe(CO)B3H8] and closo -[(Cp*M)2B5H9] (M = Mo, W)EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 11 2009K. Geetharani Abstract Reaction of [Cp*Fe(CO)2I] (Cp* = ,5 -C5Me5) with an excess amount of BH3·thf in toluene at 75 °C or with LiBH4 at ,78 °C leads to the isolation of hydrogen-rich ferraborane arachno -[Cp*Fe(CO)B3H8] in good yield. In a similar fashion, reaction of [Cp*M(CO)3Cl] (M = Mo and W) with an excess amount of BH3·thf at 80 °C or at ,78 °C with LiBH4 yielded metallaboranes [(Cp*M)2B5H9] (M = Mo, W). Isolated yields of closo -[(Cp*M)2B5H9], (M = Mo and W), both from LiBH4 and BH3·thf, are good. All compounds were characterized in solution by IR, 1H, 11B, and 13C NMR spectroscopy and mass spectrometry and the structural types were unequivocallyestablished by crystallographic analysis of arachno -[Cp*Fe(CO)B3H8].(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Synthesis and Structure of [nPr3N(CH2)6NnPr3][CuFe3Br3(SePh)6], [Cu5Fe(SePh)7(PPh3)4] and [Cu4Fe3(SePh)10(PPh3)4],EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2007Andreas Eichhöfer Abstract CuBr and Fe(OOCCH3)2 react with PhSeSiMe3 in acetonitrile in the presence of the diammonium salt [nPr3N(CH2)6NnPr3]Br2 to yield ionic [nPr3N(CH2)6NnPr3][CuFe3Br3(SePh)6]. The neutral complexes [Cu5Fe(SePh)7(PPh3)4] and [Cu4Fe3(SePh)10(PPh3)4] were obtained by similar reactions of different stoichiometric mixtures of CuOOCCH3 and FeCl2 with PPh3 and PhSeSiMe3. The crystal structures of the compounds were determined by single-crystal X-ray analysis to give new structural types of molecular cluster compounds formed by copper, iron and selenium. Thermal treatment of [Cu5Fe(SePh)7(PPh3)4] and [Cu4Fe3(SePh)10(PPh3)4] resultsin the formation of mixtures of binary Cu2Se and ternaryCuFeSe2.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Structure-Dependent Electrochemical Behavior of Thienylplatinum(II) Complexes of N,N-HeterocyclesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2004Feng Zhao Abstract trans -[Pt(MeCN)(PPh3)2(2-thienyl)]BF4 (1) serves as a convenient precursor to bifunctional mononuclear trans -[Pt(PPh3)2(,1 - N - N)(2-thienyl)]BF4 [N - N = pyrazine (2); 2-chloropyrazine, (3)] and dinuclear trans,trans -[Pt2(PPh3)4(,- N - N)(2-thienyl)2](BF4)2 [(N - N = 4,4, -bipyridine (4); 4,4, -vinylenedipyridine (5)] complexes. The nuclear selectivity is conveniently controlled by the choice of the heterocyclic ligands or spacers. Both structural types 3 and 5 were confirmed by single-crystal X-ray crystallographic analyses. Their solution identities were established by positive-ion Electrospray Mass Spectrometry (ESMS). The electroactivities of these complexes were studied by cyclic voltammetry (CV). Continuous CV scans of 4 and 5 revealed variations in the redox waves with the number of scans. While the initial oxidative scan exhibited only a broad, irreversible wave, further cycling showed the growth of two additional redox couples up to about the tenth cycle. The peak currents of these redox couples began to decay with prolonged potential cycling beyond the tenth cycle. These findings are consistent with the formation of electroactive oligomers/polymers, and this conclusion is supported by visible thin film formation on the electrodes. In contrast, the mononuclear complexes (2 and 3) do not show such behavior. The films formed were further studied by repetitive potential cycling and XPS. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Achieving efficient delivery of morpholino oligos in cultured cellsGENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 3 2001Paul A. Morcos Abstract Summary: One of the many features that make morpholino oligos unique among the antisense structural types is an uncharged backbone. While this feature eliminates the nonspecific interactions of traditional S-oligos, it also renders the morpholino undeliverable via the traditional lipid-based delivery systems. This article describes a highly efficient method of delivering morpholino oligos into adherent and nonadherent cultured cells. In this system, a nonionic morpholino oligo is paired to a complementary DNA "carrier." The DNA is then bound electrostatically to a partially ionized, weakly-basic ethoxylated polyethylenimine (EPEI). This morpholino/DNA/EPEI complex is efficiently endocytosed, and when the pH drops within the endosome, the EPEI more fully ionizes, resulting in permeabilization of the endosomal membrane and release of the morpholino into the cytosol. This article describes optimization of delivery in HeLa cells and provides the basis for delivery in any cultured endocytic cell type. genesis 30:94,102, 2001. © 2001 Wiley-Liss, Inc. [source] Elephant calling patterns as indicators of group size and composition: the basis for an acoustic monitoring systemAFRICAN JOURNAL OF ECOLOGY, Issue 1 2003Katharine B. Payne The paper gives evidence that the vocal activity of elephants varies with group size, composition and reproductive status, and that elephants' calling patterns could therefore provide the basis for a remote monitoring system. We examined a 3-week set of array-based audio recordings of savanna elephants (Loxodonta africana), searching for diagnostic acoustic parameters. An acoustic array made it possible to locate recorded sounds and attribute the calls to particular elephants or elephant groups. Simultaneous video recordings made it possible to document visible behaviour and roughly correlate it with vocalizations. We compared several measures of call density in elephant groups containing up to 59 individuals, and found that rates of calling increased with increasing numbers of elephants. We divided all call events into three structural types (single-voice low-frequency calls, multiple-voice clustered low-frequency calls, and single-voice high frequency calls), and found that the incidence of these varies predictably with group composition. These results suggest the value of a network of listening systems in remote areas for the collection of information on elephant abundance and population structure. Résumé Cet article donne des preuves du fait que l'activité vocale des éléphants varie avec la taille du groupe, sa composition et le statut reproducteur, et que le schéma des appels des éléphants pourrait donc constituer la base d'un système de contrôle continu à distance. Nous avons examiné trois semaines d'enregistrements audio d'éléphants de savane (Loxodonta africana) pour chercher des paramètres de diagnostic acoustique. Un arrangement acoustique permit de localiser les sons enregistrés et d'attribuer les appels à des éléphants identifiés ou à des groupes. Des enregistrements vidéo simultanés ont permis de documenter un comportement visible et de le mettre grossièrement en rapport avec les vocalisations. Nous avons comparé plusieurs mesures d'intensité d'appel dans des groupes qui comptaient jusqu'à 59 individus et nous avons constaté que le taux des appels augmentait avec le nombre d'éléphants. Nous avons classé tous les appels en trois types structuraux (appels à basse fréquence d'une voix unique, appels à basse fréquence de voix multiples, appels à haute fréquence d'une voix unique) et nous avons constaté que l'incidence de ceux-ci varie de façon prévisible selon la composition du groupe. Ces résultats incitent à croire qu'un réseau de systèmes d'écoute dans des endroits éloignés serait très utile pour la récolte d'informations sur l'abondance des éléphants et la structure de leurs populations. Introduction [source] Differential correlates of diet and phylogeny on the shape of the premaxilla and anterior tooth in sparid fishes (Perciformes: Sparidae)JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 5 2004M. Linde Abstract We explore the correlational patterns of diet and phylogeny on the shape of the premaxilla and anterior tooth in sparid fishes (Perciformes: Sparidae) from the western Mediterranean Sea. The premaxilla is less variable, and in spite of the presence of species-specific features, a common structural pattern is easily recognizable in all species (i.e. the ascending and the articular processes are fused in a single branch, as in many percoid fishes). In contrast, tooth shape is more variable, and different structural types can be recognized (e.g. canine-like or incisive). Coupling geometric morphometric and comparative methods we found that the relationship between shape, diet and phylogeny also differs between premaxilla and tooth. Thus, the shape of the premaxilla is significantly correlated with food type, whereas the shape of the teeth is not correlated with diet, and probably reflects the species phylogenetic relationships. Two biological roles, resistance against compressive forces generated in the buccal cavity and the size of the oral gape, would explain the ecomorphological patterns of the premaxilla. The premaxilla and anterior tooth appear to evolve at different rates (mosaic evolution) and represent an example of morphological traits belonging to the same functional unit but following uncoupled evolutionary pathways. [source] Later Prehistory in South-East Scotland: A Critical ReviewOXFORD JOURNAL OF ARCHAEOLOGY, Issue 4 2001D.W. Harding This paper reviews the progress of research over the past twenty years, with particular reference to enclosed and unenclosed settlement, agricultural patterns, domestic structural types and burial practices of the Iron Age in the south-eastern Borders. The concept of a ,trend towards enclosure' in the first millennium BC is reviewed and rejected, not least on the grounds of evidence from excavation for the dating sequences of major enclosed sites. In consequence a new overview of the later prehistoric settlement of the region is now possible, consistent with the accumulating archaeological and environmental data. [source] Probability-based protein secondary structure identification using combined NMR chemical-shift dataPROTEIN SCIENCE, Issue 4 2002Yunjun Wang Abstract For a long time, NMR chemical shifts have been used to identify protein secondary structures. Currently, this is accomplished through comparing the observed 1H,, 13C,, 13C,, or 13C, chemical shifts with the random coil values. Here, we present a new protocol, which is based on the joint probability of each of the three secondary structural types (,-strand, ,-helix, and random coil) derived from chemical-shift data, to identify the secondary structure. In combination with empirical smooth filters/functions, this protocol shows significant improvements in the accuracy and the confidence of identification. Updated chemical-shift statistics are reported, on the basis of which the reliability of using chemical shift to identify protein secondary structure is evaluated for each nucleus. The reliability varies greatly among the 20 amino acids, but, on average, is in the order of: 13C,>13C,>1H,>13C,>15N>1HN to distinguish an ,-helix from a random coil; and 1H,>13C, >1HN ,13C,,13C,,15N for a ,-strand from a random coil. Amide 15N and 1HN chemical shifts, which are generally excluded from the application, in fact, were found to be helpful in distinguishing a ,-strand from a random coil. In addition, the chemical-shift statistical data are compared with those reported previously, and the results are discussed. A JAVA User Interface program has been developed to make the entire procedure fully automated and is available via http://ccsr3150-p3.stanford.edu. [source] Structural characterization of constituents with molecular diversity in fractions from Lysidice brevicalyx by liquid chromatography/diode-array detection/electrospray ionization tandem mass spectrometry and liquid chromatography/nuclear magnetic resonance,RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 6 2008Jing Qu A combination of electrospray ionization tandem mass spectrometry with high-performance liquid chromatography (HPLC/ESI-MSn), and hyphenation of liquid chromatography to nuclear magnetic resonance spectroscopy (HPLC/NMR), have been extensively utilized for on-line analysis of natural products, analyzing metabolite and drug impurity. In our last paper, we reported an on-line analytical method for structural identification of trace alkaloids in the same class. However, the structural types of the constituents in plants were various, such as flavanoids, terpenoids and steroids. It is important to establish an effective analytical method for on-line structural identification of constituents with molecular diversity in extracts of plants. So, in the present study, the fragmentation patterns of some isolated stilbenes, phloroglucinols and flavanoids from Lysidice rhodostegia were investigated by ESI-MSn. Their fragmentation rules and UV characteristics are summarized, and the relationship between the spectral characteristics, rules and the structures is described. According to the fragmentation rules, NMR and UV spectral characteristics, 24 constituents of different types in the fractions from L. brevicalyx of the same genus were structurally characterized on the basis of HPLC/HRMS, HPLC-UV/ESI-MSn, HPLC/1H NMR and HPLC/1H- 1H COSY rapidly. Of these, six (10, 13, 14, 16, 17 and 23) are new compounds and all of them are reported from L. brevicalyx for the first time. The aim is to develop an effective analytical method for on-line structural identification of natural products with molecular diversity in plants, and to guide the rapid and direct isolation of novel compounds by chemical screening. Copyright © 2008 John Wiley & Sons, Ltd. [source] Oil and Gas Accumulation in the Foreland Basins, Central and Western ChinaACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 2 2010Yan SONG Abstract: Foreland basin represents one of the most important hydrocarbon habitats in central and western China. To distinguish these foreland basins regionally, and according to the need of petroleum exploration and favorable exploration areas, the foreland basins in central and western China can be divided into three structural types: superimposed, retrogressive and reformative foreland basin (or thrust belt), each with distinctive petroleum system characteristics in their petroleum system components (such as the source rock, reservoir rock, caprock, time of oil and gas accumulation, the remolding of oil/gas reservoir after accumulation, and the favorable exploration area, etc.). The superimposed type foreland basins, as exemplified by the Kuqa Depression of the Tarim Basin, characterized by two stages of early and late foreland basin development, typically contain at least two hydrocarbon source beds, one deposited in the early foreland development and another in the later fault-trough lake stage. Hydrocarbon accumulations in this type of foreland basin often occur in multiple stages of the basin development, though most of the highly productive pools were formed during the late stage of hydrocarbon migration and entrapment (Himalayan period). This is in sharp contrast to the retrogressive foreland basins (only developing foreland basin during the Permian to Triassic) such as the western Sichuan Basin, where prolific hydrocarbon source rocks are associated with sediments deposited during the early stages of the foreland basin development. As a result, hydrocarbon accumulations in retrogressive foreland basins occur mainly in the early stage of basin evolution. The reformative foreland basins (only developing foreland basin during the Himalayan period) such as the northern Qaidam Basin, in contrast, contain organic-rich, lacustrine source rocks deposited only in fault-trough lake basins occurring prior to the reformative foreland development during the late Cenozoic, with hydrocarbon accumulations taking place relatively late (Himalayan period). Therefore, the ultimate hydrocarbon potentials in the three types of foreland basins are largely determined by the extent of spatial and temporal matching among the thrust belts, hydrocarbon source kitchens, and regional and local caprocks. [source] Basic Types and Structural Characteristics of Uplifts: An Overview of Sedimentary Basins in ChinaACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 2 2009Dengfa HE Abstract: The uplift is a positive structural unit of the crust It is an important window for continental dynamics owing to its abundant structural phenomena, such as fault, fold, unconformity and denudation of strata. Meanwhile, it is the very place to store important minerals like oil, natural gas, coal and uranium. Giant and large-scale oil and gas fields in China, such as the Daqing Oilfield, Lunnan-Tahe Oilfield, Penglai 19,3 Oilfield, Puguang Gas Field and Jingbian Gas Field, are developed mainly on uplifts. Therefore, it is the main target both for oil and gas exploration and for geological study. The uplift can be either a basement uplift, or one developed only in the sedimentary cover. Extension, compression and wrench or their combined forces may give rise to uplifts. The development process of uplifting, such as formation, development, dwindling and destruction, can be taken as the uplifting cycle. The uplifts on the giant Precambrian cratons are large in scale with less extensive structural deformation. The uplifts on the medium- and small-sized cratons or neo-cratons are formed in various shapes with strong structural deformation and complicated geological structure. Owing to changes in the geodynamic environment, uplift experiences a multi-stage or multi-cycle development process. Its geological structure is characterized in superposition of multi-structural layers. Based on the basement properties, mechanical stratigraphy and development sequence, uplifts can be divided into three basic types , the succession, superposition and destruction ones. The succession type is subdivided into the maintaining type and the lasting type. The superposition type can be subdivided into the composite anticlinal type, the buried-hill draped type, the faulted uplift type and the migration type according to the different scales and superimposed styles of uplifts in different cycles. The destruction type is subdivided into the tilting type and the negative inverted type. The development history of uplifts and their controlling effects on sedimentation and fluids are quite different from one another, although the uplifts with different structural types store important minerals. Uplifts and their slopes are the main areas for oil and gas accumulation. They usually become the composite oil and gas accumulation zones (belts) with multiple productive formations and various types of oil and gas reservoirs. [source] From Metallaborane to Borylene Complexes: Syntheses and Structures of Triply Bridged Ruthenium and Tantalum Borylene ComplexesCHEMISTRY - A EUROPEAN JOURNAL, Issue 37 2010K. Geetharani Abstract Reaction of [1,2-(Cp*RuH)2B3H7] (1; Cp*=,5 -C5Me5) with [Mo(CO)3(CH3CN)3] yielded arachno -[(Cp*RuCO)2B2H6] (2), which exhibits a butterfly structure, reminiscent of 7 sep B4H10. Compound 2 was found to be a very good precursor for the generation of bridged borylene species. Mild pyrolysis of 2 with [Fe2(CO)9] yielded a triply bridged heterotrinuclear borylene complex [(,3 -BH)(Cp*RuCO)2(,-CO){Fe(CO)3}] (3) and bis-borylene complexes [{(,3 -BH)(Cp*Ru)(,-CO)}2Fe2(CO)5] (4) and [{(,3 -BH)(Cp*Ru)Fe(CO)3}2(,-CO)] (5). In a similar fashion, pyrolysis of 2 with [Mn2(CO)10] permits the isolation of ,3 -borylene complex [(,3 -BH)(Cp*RuCO)2(,-H)(,-CO){Mn(CO)3}] (6). Both compounds 3 and 6 have a trigonal-pyramidal geometry with the ,3 -BH ligand occupying the apical vertex, whereas 4 and 5 can be viewed as bicapped tetrahedra, with two ,3 -borylene ligands occupying the capping position. The synthesis of tantalum borylene complex [(,3 -BH)(Cp*TaCO)2(,-CO){Fe(CO)3}] (7) was achieved by the reaction of [(Cp*Ta)2B4H8(,-BH4)] at ambient temperature with [Fe2(CO)9]. Compounds 2,7 have been isolated in modest yield as yellow to red crystalline solids. All the new compounds have been characterized in solution by mass spectrometry; IR spectroscopy; and 1H, 11B, and 13C,NMR spectroscopy and the structural types were unequivocally established by crystallographic analysis of 2,6. [source] | ||||||||||||||||