Sur l'existence des opérateurs d'onde pour l'équation de Wigner dans les espaces L2,pExistence of wave operators for the Wigner equation in L2,p spaces

Basing on the formalism established by Markovich, we show the completeness of wave operators for the Wigner equation in L². In the second part, using estimations proved by Castella and Perthame on the one hand, and the L^p→L^q estimations for the Schrödinger group on the other hand, we prove the existence of the wave operators in L^2,p spaces. To cite this article: H. Emamirad, P. Rogeon, C. R. Acad. Sci. Paris, Ser. I 334 (2002) 811–816.     

Sorption of cesium from aqueous waste solution on a SuperLigÒ644 resin

Summary The removal of cesium from aqueous waste solution was investigated in a column setup using a relatively coarse SuperLig^ò644 resin. The bed volume (BV=140) at the onset of breakthrough surpassed the design requirement of 100 BV at 50% breakthrough, and also corresponds to 99.96% cesium removal. Cesium elution with 0.5M HNO₃was satisfactory with a peak BV of 2.5. The elution BV for C/C₀=0.01 was 10, which is less than the target of 15 BV. The percent of sorbed cesium eluted was 99.88%. Further, the BV of the various solutions used for the supporting process steps was sufficient.     

60keV质子辐照对TiNi记忆合金薄膜马氏体相变的影响

 利用磁控溅射的方法在氧化后的单晶Si基片上制备了TiNi形状记忆合金薄膜，利用示差扫描量热法和原位X射线衍射研究了薄膜的马氏体相变特征。通过60keV质子注入（辐照）薄膜样品研究了H+离子对合金薄膜马氏体相变特征的影响，结果表明氢离子注入后引起了马氏体相变开始Ms和结束点Mf以及逆马氏体相变开始As和结束温度Af的下降，而对R相变开始Rs和结束温度Rf影响不大。掠入射X射线衍射表明H+离子注入后有氢化物形成。H⁺离子注入形成的氢化物是引起相变点的变化的主要因素。     

An efficient and facile one-step synthesis of highly substituted thiophenes

An efficient one-step method for the synthesis of fully substituted thiophenes, from thiomorpholides and α-halo ketones, was developed. A mechanism has also been proposed for the course of reaction.     

电感耦合等离子体发射光谱法同时测定涂料中的Pb、Cd、Cr和Hg

研究了电感耦合等离子体发射光谱法测定涂料中的重金属Pb，Cd，Cr和Hg，确定了测定涂料中的重金属Pb，Cd，Cr和Hg的最佳条件。加标回收试验和实际样品测定结果表明，方法的回收率和精密度分别在99.5％-110．0％和0．95％-1．98％范围，该方法快速、准确、可靠，各元素的检出限能满足涂料安全标准，适用于涂料的日常检验。     

On Surfaces of Finite Chen — Type

We investigate some relations concerning the first and the second Beltrami operators corresponding to the fundamental forms I, II, III of a surface in the Euclidean space E³ and we study surfaces which are of finite type in the sense of B.-Y. Chen with respect to the fundamental forms II and III.     

Lie-group method solution for two-dimensional viscous flow between slowly expanding or contracting walls with weak permeability

The non-linear equations of motion describing the laminar, isothermal and incompressible flow in a rectangular domain bounded by two weakly permeable, moving porous walls, which enable the fluid to enter or exit during successive expansions or contractions, are considered. We apply Lie-group method for determining symmetry reductions of partial differential equations. Lie-group method starts out with a general infinitesimal group of transformations under which given partial differential equations are invariant, then, the determining equations are derived. The determining equations are a set of linear differential equations, the solution of which gives the infinitesimals of the dependent and independent variables. After the group has been determined, a solution to the given partial differential equation may be found from the invariant surface condition such that its solution leads to similarity variables that reduce the number of independent variables in the system. Effect of the permeation Reynolds number R_e and the dimensionless wall dilation rate α on self-axial velocity have been studied both analytically and numerically and the results are plotted.     

MOCVD生长的GaN单晶膜透射光谱研究

采用MOCVD技术在Al2O3(0001)衬底上生长了GaN薄膜，使用透射光谱、光致发光光谱和X射线双晶衍射三种技术测试了五类GaN薄膜样品，实验结果表明：GaN薄膜透射谱反映出的GaN质量与X射线双晶衍射测量的结果一致，即透射率越大，半高宽越小，结晶质量越好；而X射线双晶衍射峰半高宽最小的样品，其PL谱的带边峰却很弱，这说明PL谱反映样品的光学性能与X射线双晶衍射获得的结晶质量不存在简单的对应关系，同时还报导了一种特殊工艺生长的高阻GaN样品的RBS／沟道结果。     

Colossal magnetoresistance manganites: A new approach

Manganites of the LA_1−x Ca _x MnO₃ family show a variety of new and poorly understood electronic, magnetic and structural effects. Here we outline a new approach recently proposed by us, where we argue that due to strong Jahn-Teller (JT) coupling with phonons the twofold degeneratee _g states at the Mn sites dynamically reorganize themselves into localised, JT polaronsl with exponentially small inter-site hopping, and band-like, nonpolaronic statesb, leading to anew 2-band model for manganites which includes strong Coulomb and Hund’s couplings. We also discuss some results from a dynamical mean-field theory treatment of the model which explains quantitatively a wide variety of experimental results, including insulator-metal transitions and CMR, in terms of the influence of physical conditions on the relative energies and occupation of thel andb states. We argue that this microscopic coexistence of the two types of electronic states, and their relative occupation and spatial correlation is the key to manganite physics. Dedicated to Professor C N R Rao on his 70th birthday