单位球面上仿Blaschke张量的特征值为常数的超曲面

设x:M~n→S~(n+1)是(n+1)-维单位球面上不含脐点的超曲面,在S~(n+1)的Moebius变换群下浸入x的四个基本不变量是:一个黎曼度量g称为Moebius度量;一个1-形式Φ称为Moebius形式;一个对称的(0,2)张量A称为Blaschke张量和一个对称的(0,2)张量B称为Moebius第二基本形式.对称的(0,2)张量D=A+λB也是Moebius不变量,称为浸入x的仿Blaschke张量,其中λ是常数,仿Blaschke张量的特征值称为仿Blaschke特征值.李海中和王长平(2003)研究了满足如下条件的超曲面:(i)Φ=0;(ii)存在可微函数λ和μ,使A+λg+μB=0.他们证明了λ和μ都是常数,并且给出了这类超曲面的分类,也就是D的特征值全相等的超曲面的分类.本文对满足如下条件的超曲面进行了分类:(i)Φ=0,(ii)对某一个常数λ,D具有两个互异的常数特征值.     

Aerodynamic optimization of 3D wing based on iSIGHT

A method for combining the CFD software,Fluent,with the iSIGHT design platform is presented to optimize a three-dimensional wing to ameliorate its aerodynamics performance.In the optimization design,two kinds of genetic algorithms,the Neighborhood Cultivation Genetic Algorithm（NCGA）and the Non-dominated Sorting Genetic Algorithm（NSGAII）,are employed and the Navier-Stoke（N-S）equations are adopted to derive the aerodynamics functions of the 3D wing.The aerodynamic performance of the optimized wing has been significantly improved,which shows that the approach can be extended and employed in other cases.     

带干扰的积分高斯过程的破产概率

本文研究了带干扰的积分高斯过程的破产概率.利用经典大偏差的方法,在一定的条件下,得到了相应概率的对数渐近式及测度族的大偏差原理.结果表明在不带干扰的情形下与已有结果一致.     

MODERATE DEVIATIONS AND LARGE DEVIATIONS FOR A TEST OF SYMMETRY BASED ON KERNEL DENSITY ESTIMATOR

Let fn be a non-parametric kernel density estimator based on a kernel function K. and a sequence of independent and identically distributed random variables taking values in R. The goal of this article is to prove moderate deviations and large deviations for the statistic sup ｜fn（x） - fn（-x） ｜.     

关于稳定单变度曲线自动判别的一种简便的普适性方法

无变度点周围各单变度曲线稳定性的自动判别，是多体系稳定平衡相图计算机成图理论中十分关键而棘手的问题。它既令化学家感兴趣，更为地质地球化学家、冶金学家、材料学家所关注。在这方面，已有不少学者做过探讨，其基本依据是“等温等压下达到平衡时体系的Ｇｉｂｂｓ自...     

简洁普适的多体系稳定平衡相图计算机成图理论与方法--SFM法

提出了单变度曲线稳定部分相应变量区间的简易求法及无变度点稳定性的新判别方法，此法与前文方法一起构成了一套完整、普适、简洁的多体系稳定平衡相图计算机成图理论──符号函数矩阵（ＳＦＭ）判别法．其主要步骤有：△_ｒＧ_ｍ导数（或差分）法确定稳定单变度曲线的排列格式；曲线相互关系比较法将单变度曲线分组；坐标值比较法确定曲线稳定存在的变量区间；公有曲线与无变度点关系比较法确定无变度点的稳定性．该法适用于封闭或开放体系、二维或多维相图“空间”中的各类相图．     

三氟乙酸对氨基酸催化不对称直接Aldol反应的影响

研究了三氟乙酸(TFA)对各种L-α-氨基酸催化环己酮与对硝基苯甲醛的不对称直接Aldol反应的影响.结果表明:在TFA作用下,所测试的绝大部分氨基酸的催化性能都有显著变化,多数情况下能提高收率和对映选择性;对非对映选择性的影响无明显规律.     

公众聚集场所火灾风险的模糊综合评价方法研究

公众聚集场所的火灾风险有其自身的特点.在分析公众聚集场所火灾风险因素的基础上,探讨了该场所火灾风险的模糊综合评价方法,为该场所火灾风险评价提供一种方法尝试,为火灾风险管理提供理论上的、量化的依据.     

Investigation of a Microcalorimeter for Thin-Film Heat Capacity Measurement

A microcalorimeter is studied for testing heat capacity of thin films. The microcalorimeter is a suspended membrane supported by six microbridges, which is fabricated by the front-side surface micromachining. Compared to the bulk micro-machined one, the microcalorimeter has excellent mechanical strength and precisely controlled pattern size as well as good thermal characteristics that are essential to a microcalorimeter. The heating rate of the microcalorimeter is up to 2 × 10^5Kis with 4.5mW heating power in vacuum, and the heat capacity of the corresponding empty microcalorimeter is about 23.4nJ/K at 30OK. By a pulse calorimetry, the heat capacity of A1 thin films with thickness of 40-1150nm are measured in the temperature range from 300K to 420K in vacuum. The mass of each sample is evaluated and the specific heat capacity is calculated. The results show that specific heat capacity of the 1150-nm A1 film agrees well with the data of bulk A1 reported in the literature. For the thinner films, enhanced heat capacity is observed.     

扑热息痛的光化学荧光特性及其分析应用

研究了扑热息痛（ＰＲ）的在线光化学荧光特性。发现丙酮可提高ＰＲ的光化学反应速率并增强其光化学荧光强度；反应介质的ＰＨ值（７．７～１１．２）对光化学反应的速率影响不大，但对光化学荧光的强度影响明显。以含有０．０４％丙酮的ＰＨ９．６硼砂硼砂缓冲液作为反应介质，建立了流动注射在线光化学荧光测定扑热息痛的新方法，检测限（３σ）为１９μｇ／Ｌ，相对标准偏差为０．６％，分析速度达６０次／ｈ。应用本法测定了４种