CORIS®: Literatur-Datenbank

CORIS™: Literature database The literature database integrated in the CORIS system supports the user with additional information. It includes about 70 000 abstracts which come from the DECHEMA e.V., NACE and METADEX. The DECHEMA Corrosion Thesaurus is also implemented in German and English. The user can initiate a full text search as well as a field specific search. A data input form (mask) is programmed for the user's own data implementation.     

苏里格气田全数字地震勘探技术及应用

苏里格气田是迄今为止中国陆上发现的最大天然气田,该气田的主要含气目标层系内,有效储层(气层)厚度小、横向变化快,钻井风险很大。从有效储层的地质及地球物理特征分析出发,论证了有效储层地震预测的思路和可行性,从而有针对性地提出了全数字地震野外资料采集方法。在资料处理中,强调对叠前道集动力学特征的保持性处理,获得了可用于叠前反演输入的高品质CDP道集。在此基础上,利用叠前反演和AVO分析预测天然气有效储层。2006年在苏里格气田100km2的范围内,通过全数字地震的配套技术,共提供开发井位30口,钻探评价结果显示,钻井成功率由以前的60%提高到90%,气层钻遇率达到100%,极大地提高了气田开发的经济效益。     

Extremely Efficient Cross‐Coupling of Benzylic Halides with Aryltitanium Tris(isopropoxide) Catalyzed by Low Loadings of a Simple Palladium(II) Acetate/Tris(p‐tolyl)phosphine System

Highly efficient coupling reactions of benzylic bromides or chlorides with aryltitanium tris(isopropoxide) [ArTi(O‐i‐Pr)₃] catalyzed by a simple palladium(II) acetate/tris(p‐tolyl)phosphine [Pd(OAc)₂/ P(p‐tolyl)₃] system are reported. The coupling reactions proceed in general at room temperature employing low catalyst loadings of 0.02 to 0.2 mol%, affording coupling products in excellent yields of up to 99%. For benzylic bromides bearing strong electron‐withdrawing cyano (CN) or trifluoromethyl (CF₃) substituents, the reactions require a higher catalyst loading of 1 mol%, or the reactions are carried out at 60 °C. The catalytic system also tolerates (1‐bromoethyl)benzene bearing β‐hydrogen atoms while using a catalyst loading of 1 mol% to afford the coupling product in a 70% yield.     

Effects of poly(methyl methacrylate)‐based low‐profile additives on the properties of cured unsaturated polyester resins. I. Miscibility,curing behavior,and glass‐transition temperatures

The effects of three series of self‐synthesized poly(methyl methacrylate) (PMMA)‐based low‐profile additives (LPAs), including PMMA, poly(methyl methacrylate‐co‐butyl acrylate), and poly(methyl methacrylate‐co‐butyl acrylate‐co‐maleic anhydride), with different chemical structures and MWs on the miscibility, cured‐sample morphology, curing kinetics, and glass‐transition temperatures for styrene (ST)/unsaturated polyester (UP) resin/LPA ternary systems were investigated by group contribution methods, scanning electron microscopy, differential scanning calorimetry (DSC), and dynamic mechanical analysis, respectively. Before curing at room temperature, the degree of phase separation for the ST/UP/LPA systems was generally explainable by the calculated polarity difference per unit volume between the UP resin and LPA. During curing at 110°C, the compatibility of the ST/UP/LPA systems, as revealed by cured‐sample morphology, was judged from the relative magnitude of the DSC peak reaction rate and the broadness of the peak. On the basis of Takayanagi's mechanical models, the effects of LPA on the final cure conversion and the glass‐transition temperature in the major continuous phase of ST‐crosslinked polyester for the ST/UP/LPA systems was also examined. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3369–3387, 2004     

Effects of poly(vinyl acetate) and poly(vinyl chloride‐co‐vinyl acetate) low‐profile additives on properties of cured unsaturated polyester resins. II. glass‐transition temperatures and mechanical properties

Three series of self‐synthesized poly(vinyl acetate)‐based low‐profile additives (LPAs), including poly(vinyl acetate), poly(vinyl chloride‐co‐vinyl acetate), and poly(vinyl chloride‐co‐vinyl acetate‐co‐maleic anhydride), with different chemical structures and molecular weights were studied. Their effects on the glass‐transition temperatures and mechanical properties for thermoset polymer blends made from styrene, unsaturated polyester, and LPAs were investigated by an integrated approach of the static phase characteristics, cured sample morphology, reaction kinetics, and property measurements. Based on Takayanagi mechanical models, the factors that control the glass‐transition temperature in each phase region of the cured samples and the mechanical properties are discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3347–3357, 2003     

The coupling influence of size effects and strain rates on the formability of austenitic stainless steel 304 foil

In order to understand the coupling influence of size effects and strain rates on the formability of the austenitic stainless steel 304 foils in micro scale, a series of micro scale limited dome height (LDH) tests were designed and conducted in three different speeds without lubricant on the annealed and as-received austenitic stainless steel 304 foils. In this study, a technique was developed to coat a layer of pure chromium (≈0.3 μm thick) on the foils and by using the etching process to make the micro square grids (50 μm × 50 μm) on the foils. Then, the foils were annealed at different temperatures for obtaining different microstructures. A set of the forming limit curves (FLC) of the foils were obtained and they can be used by industry right away for product design, process design and development, die design, and simulations, etc. Besides, the coupling influence of the size effects and the strain rates on the formability of the austenitic stainless steel 304 foils has been studied, observed and understood.     

Idiopathic perforation of the colon in a newborn

Although infrequent, idiopathic perforation of the colon in the newborn is a surgical emergency. Etiology remains obscure. Diagnosis of a pneumoperitoneum, prompt operative intervention, and the use of antibiotic therapy are essential to the survival of these infants.     

Optimal short‐term scheduling of shunt compensators via a decomposition algorithm

Abstract

The short term (one day) scheduling of VAr controllers involves the setting of shunt compensators, EHV taps and generator voltages. A decomposition approach is presented to solve the problem of optimal short‐term scheduling of shunt compensators in this paper. The entire problem is decomposed into two levels: the master and the slave levels. The master level deals with minimization of the depreciation cost of compensators in order to reduce the control actions for compensators while satisfying operating constraints. The slave level treats minimization of capitalized MW losses while satisfying system security constraints by adjusting generator voltages and taps. These two levels interact through linear constraints in the iteration process. The IEEE 30‐bus and a practical 265‐bus systems, namely Taiwan Power System, are used to serve as samples to show the applicability of the presented approach.     

Identification of material and geometrical parameters for microstructures by dynamic finite element model updating

This paper describes a procedure to identify material and geometrical parameters for microstructures using the concept of finite element model updating. This scheme utilizes measured and finite element analysis (FEA) natural frequencies that are paired together according to their mode shapes, and it incorporates an optimization sequence that formulates the frequency differences as an error vector to be minimized. To demonstrate the effectiveness of the proposed procedure, two examples are shown in this paper. One example involves a microcantilever fabricated from a single-crystalline silicon wafer, and the updating process is applied on the cantilever to identify its Young’s modulus. The identified Young’s modulus (along <100> direction) of 130.29 GPa is very comparable to those in the literature. The other example concerns a commercial, V-shaped silicon nitride probe used in an atomic force microscope. The natural frequencies and mode shapes of the probe are measured, the FEA performed, and the probe thickness and the Young’s modulus of the silicon nitride substrate determined. The identified thickness is also verified by SEM images of the probe. Both examples show that the updating procedure converged in just a few iterations.     

镁合金压铸件的生产

叙述了镁合金的特性,并讨论了镁合金贮存、熔炼、精炼以及压铸模具等对生产优质镁压铸件的影响。