Jensen's inequality for g-expectation: part 1

Briand et al. (Electron. Comm. Probab. 5 (2000) 101–117) gave a counterexample and proposition to show that given g,g-expectations usually do not satisfy Jensen's inequality for most of convex functions. This yields a natural question, under which conditions on g, do g-expectations satisfy Jensen's inequality for convex functions? In this paper, we shall deal with this question in the case that g is convex and give a necessary and sufficient condition on g under which Jensen's inequality holds for convex functions. To cite this article: Z. Chen et al., C. R. Acad. Sci. Paris, Ser. I 337 (2003).     

Analysis on Shack–Hartmann wave-front sensor with Fourier optics

In Shack–Hartmann wavefront sensor (SHWS), the behavior of the irradiance pattern produced by the micro-lens array is important for an accurate centroid estimation. In this paper, the behavior of a micro-lens array in SHWS is analyzed using Fourier optics, and reveals that in addition to the main, expected spots, secondary spots with smaller intensities also appeared as a result of diffraction by the small dimensions of the micro-lens and interference from the different micro-lenses. This result is confirmed by comparing with a irradiance pattern taken from an actual SHWS. The additional error in centroid estimation caused by these secondary spots is discussed and relationship to the parameters of the micro-lens of SHWS is analyzed.     

PVC基活性炭的制备及其吸附性能的研究Ⅰ——PVC沥青的制备及其预氧化

以PVC树脂为原料,采用两个恒温段的程序升温方法加热脱氯制备PVC沥青,并通过空气预氧化法,对所制备的PVC沥青进行了预氧化处理.实验结果表明,PVC树脂在流速为100 mL/min氮气气氛中,以10℃/min速率程序升温至270℃,恒温脱氯150 min后再程序升温至410℃并恒温芳化120 min,可以制备出脱氯率和得率均较高的PVC沥青.该PVC沥青在300℃温度下,采用空气预氧化法预氧化120min,可获得增重率约为11%,氧化交联度较高、耐热性能较好的预氧化PVC沥青.FT-IR光谱分析结果表明,PVC沥青在预氧化的过程中,主要发生了氧化脱氢、脱水、CO2缩聚交联反应,使沥青形成耐热型的氧桥结构,从而达到预氧化目的.     

精选实验素材加强实验教学

多年来人们对实验教学加以重视的同时却陷入了一个误区：只重视做好课堂演示实验和学生分组实验，而忽视了课外小实验的作用．其实，经常性地引导学生自己动手，就地取材，开展课外小实验、小制作，对加强物理实验教学，加深对物理知识的理解，提高学生的分析解决问题的能力，将会起到重要的作用．     

半导体激光器发射光谱实验仪

设计了一种半导体激光器发射光谱实验仪 ,可以用来观测LD发射的荧光光谱、激光光谱 ,以及了解光栅外腔选取单纵模、压窄线宽、波长调谐的机理 .该实验仪结构紧凑 ,物理概念清晰 ,适用于大专院校的光学实验教学     

Buckling of a stiff thin film on a compliant substrate in large deformation

A finite-deformation theory is developed to study the mechanics of thin buckled films on compliant substrates. Perturbation analysis is performed for this highly nonlinear system to obtain the analytical solution. The results agree well with experiments and finite element analysis in wavelength and amplitude. In particular, it is found that the wavelength depends on the strain. Based on the accurate wavelength and amplitude, the membrane and peak strains in thin films, and stretchability and compressibility of the system are also obtained analytically.     

The effect of micro-morphology of Bi2O3 on catalytic properties of Co/Bi catalyst for wet air oxidation of acetic acid

The novel phase transfer catalysts S-8 [4-(dimethyloctylammonium) propansultan] and DB-X [1,4-bis(triethylmethylammonium)benzene dibromide] were synthesized and employed for high conversion synthesis of dichlorocyclopropane from various olefins.This revised version was published online in December 2005 with corrections to the Cover Date.     

一种改进的进化规划算法

本对于全局优化问题提出一个改进的进化规划算法，该算法以概率p接收基于电磁理论求出合力方向作为随机搜索方向，以概率1-p接收按正态分布产生的随机搜索方向。改进算法不仅克服了传统进化规划算法随机搜索的盲目性，而且保留了传统进化规划算法全局搜索性。本算法应用于几个典型例题，数值结果表明本算法是可行的，有效的。     

Crystallographic report: Diiodo[tris(2‐pyridyl)amine]mercury(II), [(C5H4N)3N]HgI2

In mononuclear HgI₂[(C₅H₄N)₃N], mercury is tetrahedrally coordinated by two nitrogen atoms of a tris(2‐pyridyl)amine ligand and two iodides. The coordination moieties are connected by weak intermolecular Hg(II)···I interactions to give a one‐dimensional structure. Copyright © 2003 John Wiley & Sons, Ltd.     

Control of self‐organized low‐dimensional morphology in poly(styrene‐b‐4vinylpyridine)/polystyrene blend thin films

The surface morphologies of poly(styrene‐b‐4vinylpyridine) (PS‐b‐P4VP) diblock copolymer and homopolystyrene (hPS) binary blend thin films were investigated by atomic force microscopy as a function of total volume fraction of PS (?_PS) in the mixture. It was found that when hPS was added into symmetric PS‐b‐P4VP diblock copolymers, the surface morphology of this diblock copolymer was changed to a certain degree. With ?_PS increasing at first, hPS was solubilized into the corresponding domains of block copolymer and formed cylinders. Moreover, the more solubilized the hPS, the more cylinders exist. However, when the limit was reached, excessive hPS tended to separate from the domains independently instead of solubilizing into the corresponding domains any longer, that is, a macrophase separation occurred. A model describing transitions of these morphologies with an increase in ?_PS is proposed. The effect of composition on the phase morphology of blend films when graphite is used as a substrate is also investigated. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3496–3504, 2004