与透视和相似相关的一个定理

1问题介绍单墫教授在文[1]第43、44题的解答中分别构造了反例来说明:(i)透视且相似的两个三角形不一定位似;(ii)透视且全等的两个三角形不一定位似,并随后提出了如下两个问题:     

Recent results from HERA

After the end of data taking in 2007,the experiments H1 and ZEUS have entered into an intense phase of data analysis.Recent results of this effort on neutral （NC） and charged current （CC） cross sections at high Q 2,the longitudinal structure function F L,inclusive diffraction,heavy flavour production and on searches for glueballs are presented.Also shown are results of a combined analysis on inclusive NC and CC cross sections performed by H1 and ZEUS using HERA-I data.     

Bonding Interface Imaging and Shear Strength Prediction by Ultrasound1

The propagation of a longitudinal ultrasonic wave normally incident upon an adhesively bonded structure is stud- ied. The structure consists of adherend and adhesive layers with finite thickness. Interfaces between adherend and adhesive are regarded as distributed springs. Theoretical and experimental results show that resonant frequencies of the bonded structure vary sensitively with the interface stiffness constants and adhesive thickness, and these interface characteristics are inversed by the simulation annealing （SA） method. Furthermore, the distribution image of interface stiffnesses is compared with the state of fracture interface, and quantitative prediction of shear strength is achieved based on the distribution of interface stiffnesses and adhesive thicknesses by using a back- propagation neutral network. The average relative error of the shear strength from prediction to real value is 10.7%.     

开链配体及手性冠醚仿生化学研究现状

综述了部分开链配体的络合行为，对手性冠醚的合成、分子识别及仿生功能的研究进行了评述，开链配体在络合行为上与环状化合物很相似，能与金属离子、中性分子形成络合物，手性冠醚的合成是一个活跃的研究领域，将手性冠醚用于手性识别、手性催化及仿生化学的研究日趋活跃，前景十分诱人。     

关于离散代数Riccati方程的扰动分析

1．引言若不特别说明,以下记号都是常规的,可参见山．在最优控制中占有核心地位的代数Xiccati方程（ARE）有两种基本形式：连续型的ARE（CARE）：离散型的＊＊E（＊＊RE）：其中只兄见NE贮””,GIE皿””m,GZE＊m”m,in＜2,＊T二K＞风＊T二N＞几＊2二＊2＞凡从应用角度看,主要关心＊＊E的对称半正定解．对于＊＊RE,已有大量的研究工作．特别,陈春晖门、徐树方问、Ghwimi－Laub同等研究了扰动理论．对于DARE,它与＊＊＊E的一个明显区别是：＊＊M是二次矩阵方程而＊＊＊E具有高度非线性．这种区别使得DARE远为复杂…     

分子束技术及其应用

介绍了分子束源,对超音速分子束的物理性能进行了描述,在此基础上介绍了分子不技术在气－固界面散动力学、分子反应动力学和分子束与激光相互作用等方面的应用现状及前景。     

A Novel Gravito-Optical Surface Trap for Neutral Atoms

We propose a novel gravito-optical surface trap （COST） for neutral atoms based on one-dimensional intensity gradient cooling. The surface optical trap is composed of a blue-detuned reduced semi-Gaussian laser beam （SGB）, a far-blue-detuned dark hollow beam and the gravity field. The SGB is produced by the diffraction of a collimated Gaussian laser beam passing through the straight edge of a semi-infinite opaque plate and then is reduced by an imaging lens. We calculate the intensity distribution of the reduced SGB, and study the dynamic process of the SGB intensity-gradient induced Sisyphus cooling for ^87Rb atoms by using Monte Carlo simulations. Our study shows that the proposed GOST can be used not only to trap cold atoms loaded from a standard magneto-optical trap, but also to cool the trapped atoms to an equilibrium temperature of 3.47μK from ～120μK, even to realize an all-optical two-dimensional Bose-Einstein condensation by using optlcal-potential evaporative cooling.     

Poincaré线性连续统直觉概念的公式化(英文)

本文研究了Poincaré著名注记中“内束”观念的数学表述法问题,通过构建Poincaré连续统模型,得到了这一问题的一种解答。文中还论述了有关数理哲学及方法论问题;文末特别指出了须继续研究的数学问题。     

一类具约束选址模型的组合算法

针对一般具闭凸集约束的单址选址模型,提出具全局收敛性的组合算法．算法在迭代中先采用信赖域技巧,当出现“内循环”时,则改用不做线搜索的梯度法．该算法既具有信赖域算法的优越性,又避免了出现“内循环”时速成的隐迭代．同时,该算法通常不需进行线搜索,较之其它组合算法更加简捷实用．