泡沫塑料吸附—石墨炉原子吸收光谱法测定地质物料中痕量铊

本文研制定了一种泡沫塑料吸附－石墨炉原子吸收光谱法测定地质物料中痕量铊的分析，在所先定的实验条件下，方法检出限为０．０５μｇ／ｇ、样准曲线范围为１０－３００ｎｇ／ｍＬ，Ｔｌ含量水平为０．７１μｇ／ｇ时的测定精度为６．０％，方法回收率９９．０％－１００．０％。经标样及大量样品分析验证，分析方法准确可靠。     

Synthesis of Heterocyclic Ring Systems for Heat-Resistant Plastics from Polyisocyanates

Investigations on space flight and rockets carried out in particular in the United States have aroused great interest in plastics with enhanced thermal stability. It has become possible to pass far beyond the expected limits of thermal stability with organic plastics, and to synthesize plastics and polymers that can be used at temperatures between about 200 and about 500 °C, a range that formerly appeared to be the exclusive province of inorganic materials.     

Weighted allocation rules for standard fixed tree games

In this paper we consider standard fixed tree games, for which each vertex unequal to the root is inhabited by exactly one player. We present two weighted allocation rules, the weighted down-home allocation and the weighted neighbour-home allocation, both inspired by the painting story in Maschler et al. (1995) . We show, in a constructive way, that the core equals both the set of weighted down-home allocations and the set of weighted neighbour allocations. Since every weighted down-home allocation specifies a weighted Shapley value (Kalai and Samet (1988)) in a natural way, and vice versa, our results provide an alternative proof of the fact that the core of a standard fixed tree game equals the set of weighted Shapley values. The class of weighted neighbour allocations is a generalization of the nucleolus, in the sense that the latter is in this class as the special member where players have all equal weights.     

An axiomatization of the inner core

We axiomatize the inner core in a similar way as the one proposed by Aumann (1985) in order to characterize the NTU value. Received: March 2002/Revised: March 2003     

Mechanical Characterization of Angle-Ply Composite Laminates by Differential Moiré Method: The Influence of Specimens' Length-to-Width Ratio

The influence exerted by the specimen proportions on the measured performance of angle-ply [+45°/–45°]_s composite laminates is studied. Three kinds of specimens are considered, having different length-to-width ratios, made with glass/epoxy unidirectional or fabric laminae. The static tensile characteristics are measured by means of load cells, electric strain gauges and through the Moiré fringes method. The strain fields are analysed and the effects of stress concentration at the laminate-free edges are evaluated, as well as their influence on the strain distribution and the measured strength and stiffness. The results are summarized as diagrams of ultimate load and elastic modulus versus length-to-width ratio of the different specimens investigated. These diagrams allow the designer to evaluate the influence exerted by specimen proportions on the measured performance, as well as to compare characteristics which are heterogeneous, as obtained with different kinds of specimen.     

Nanoscopic scale studies of LiFePO4 as cathode material in lithium-ion batteries for HEV application

We present a review of the structural properties of LiFePO₄. Depending on the mode of preparation, different impurities can poison this material. These impurities are identified and a quantitative estimate of their concentrations is deduced from the combination of X-ray diffraction analysis, Fourier transform infrared spectroscopy, Raman spectroscopy, and magnetic measurements. An optimized preparation provides samples with carbon-coated particles free of any impurity phase, insuring structural stability and electrochemical performance that justify the use of this material as a cathode element a new generation of lithium secondary batteries.     

新型有机空穴传输材料氟代四苯基联苯二胺的合成与表征

设计和合成了一种新型的有机空穴传输材料N,N'-二苯基-N,N'-双(2-氟苯基)-[1.1'-联苯]-4,4'-二胺(FTPB),通过熔点测试、元素分析、FTIR光谱和1H NMR谱等手段对其分子结构进行了表征.采用循环伏安法(CV)结合UV-Vis吸收光谱测试了其能级结构.结果表明,其HOMO能级为-5.36eV,带隙为3.20eV,有望成为优良的空穴传输材料.     

On The Maximum Friction Law for Rigid/Plastic,Hardening Materials

For a rigid/plastic, hardening material model, it is shown that the velocity fields adjacent to surfaces of maximum friction must satisfy the sticking condition. This means that the stress boundary condition, the maximum friction law, may be replaced by the velocity boundary condition. Axisymmetric flows without rotation and planar flows are considered.     

The Chemistry of the Noncrystalline State

This article sets out to describe and account for the chemical and physical consequences of the presence of gross disorder in solids. Knowledge of the structure of such disordered materials is an obvious prerequisite to a further understanding of other properties and behavior, and our current knowledge of the structure of various noncrystalline systems is discussed together with the experimental techniques which need to be employed in order to obtain such information. The so-called glass transition, which takes place as a liquid is supercooled below the crystallization temperature, is discussed in terms of the various models which have been proposed to account for this phenomenon. The effect of noncrystallinity on electronic properties is also discussed, and we highlight new developments in the understanding of electron localization and transport processes. Finally, two applications of amorphous solids are considered in some detail: optical fibers for use in communication networks and “superionic” glasses for possible use in solid-state batteries.