Numerical determination of yield surfaces of Al/SiC laminated composite plates

In this study the elastic-plastic properties of an aluminum alloy reinforced by unidirectional SiC-fibers are computed by using nonlinear finite element simulations. In order to carry out these computations, a representative volume element assuming a regular quadratic arrangement of the fibers is used. The plastic properties of the composite are described by a quadratic flow criterion which is able to consider both direction and tension-compression anisotropy. Additionally, the flow rule takes into account plastic volume changes. The hardening of the material is defined by a mixed isotropic-kinematic hardening model. By using this modeling yield surfaces of multi-layer laminated composite plates under an in-plane loading are determined.     

Methods for identifying emerging General Purpose Technologies: a case study of nanotechnologies

Nanotechnology is an emerging field of science with the potential to generate new and enhance existing products and transform the production process. US patent data is used to track the emergence of nanotechnologies since 1978. The nanotechnologies that have undergone the most development are identified using patent citation data and co-citation patterns of patents are examined to define clusters of related nanotechnologies. The potential for economic impact of the emerging nanotechnologies is assessed using a generality index.     

利用可持续指标监测与调控"大昆明区"区域城镇发展

本文针对昆明的发展特征及面临的挑战,引入了一种全覆盖的综合规划方法来从整体上协调空间的各种职能及保护自然潜力.对大昆明区采用基于GIS的区域模型模拟了这些政策和方法的潜在影响力.结果显示,污染减少、土地利用成本和基础设施的建设成本降低,同时城市的竞争力提高.     

Identification of 130 kDa cell surface LDL-binding protein from smooth muscle cells as a partially processed T-cadherin precursor

Atypical cell surface lipoprotein-binding proteins of 105 kDa and 130 kDa are present in membranes of vascular smooth muscle cells. We recently identified the 105 kDa protein from human aortic media as T-cadherin, an unusual glycosylphosphatidylinositol (GPI)-anchored member of the cadherin family of cell adhesion proteins. The goal of the present study was to determine the identity of 130 kDa lipoprotein-binding protein of smooth muscle cells. We applied different approaches that included protein sequencing of purified protein from human aortic media, the use of human T-cadherin peptide-specific antisera, and enzymatic treatment of cultured cells with trypsin and GPI-specific phospholipase C. Our results indicate that the 130 kDa protein is a partially processed form of T-cadherin which is attached to the membrane surface of smooth muscle cells via a GPI anchor and contains uncleaved N-terminal propeptide sequence. Our data disclose that, in contrast to classical cadherins, T-cadherin is expressed on the cell surface in both its precursor (130 kDa) and mature (105 kDa) forms.     

Passivity of polycrystalline NiMnGa alloys for magnetic shape memory applications

The corrosion and passivation behaviour of bulk polycrystalline martensite Ni₅₀Mn₃₀Ga₂₀ and austenite Ni₄₈Mn₃₀Ga₂₂ alloys was compared in electrolytes with different pH values. Linear anodic and cyclic potentiodynamic polarisation methods and anodic current transient measurements have been conducted for the alloys and their constituents to analyze free corrosion, anodic dissolution and passive layer formation processes. Electrochemically treated alloy surfaces were characterized with scanning electron microscopy (SEM) and angle-resolved x-ray photoelectron spectroscopy (XPS). The electrochemical response of both alloys is in principal similar and is dominated by the Ni oxidation. In acidic solutions (pH 0.5 and 5) a slightly higher reactivity is detectable for the martensitic alloy which is mainly attributed to enhanced dissolution processes at the multiple twin boundaries. In weakly acidic to strongly alkaline solutions (pH 5-11) both alloys exhibit a low corrosion rate and a stable anodic passivity. While air-formed films comprise NiOOH, Ga₂O₃ and MnO₂, passive films formed in near neutral media (pH 5-8.4) are composed of Ni(OH)₂, NiOOH and Ga₂O₃ in the outer region and of NiO, MnO₂ and MnO in the metal-near region.     

Steps toward passively safe, proliferation-resistant nuclear power

After about a 30-year hiatus of construction in the US but not in all involved countries, the designs for an improved water-cooled nuclear reactor will hopefully be developed by a consortium of nuclear reactor builders and users under an agreement with the US Department of Energy (DOE) and review by the Nuclear Regulatory Commission (NRC). The construction of high-temperature, helium-cooled pebble-bed or prismatic reactors may herald the entry of new, safer, and less costly types of reactors to replace the water-cooled reactors of the past and current types. Nuclear breeder reactors hold the promise of limitless energy supplies without the use of fossil fuels or renewables at acceptable costs but this development program has been stalled periodically, especially in the US, when abundant low-cost uranium sources were added to the supply side.     

Family structure and the externalizing behavior of children from economically disadvantaged families.

This study examined the relations among family structure, caregiver relationship history, aspects of environmental adversity, and teacher reports about the externalizing behaviors of 6- and 7-year-old children from economically disadvantaged families. Family structure contrasted intact families, stepfamilies, single-parent families, and cohabiting families. Problem behaviors were more frequent for children from unmarried families than from married families and were more frequent for boys than for girls from cohabiting families. Relationship history reduced the effects for family structure. Children's adjustment varied with both the current status and past stability of caregiver intimate relationships for disadvantaged families. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The adsorption behaviour of faba bean proteins at a sunflower oil-water interface

The present study aims at investigating the absorption behaviour of acetylated (AFBPI) and non-acetylated (FBPI) faba bean protein isolate at a sunflower oil-water interface in dependence on different environmental conditions (protein concentration, pectin addition).