膀胱移行细胞癌患者人类白细胞抗原G的表达及其与临床病理学特征的相关性

目的探讨膀胱移行细胞癌组织中人类白细胞抗原G （HLA- G）的表达及其与临床病理特征的关系。方法选取62例膀胱移行细胞癌手术切除标本组织，另取术中癌旁正常膀胱黏膜组织标本作为对照，采用免疫组织化学Envision方法检测两种组织中HLA- G的表达情况，并分析其与临床病理特征的关系。结果62例膀胱移行细胞癌患者中43例（69.4%）HLA- G阳性表达，20例癌旁正常膀胱黏膜组织中均未见HLA- G阳性表达。HLA- G的表达水平与膀胱移行细胞癌患者性别、年龄、肿瘤数目、临床分期、组织学分级均无明显相关性（均P＞0.05）。结论膀胱移行细胞癌组织中HLA- G表达上调，HLA- G高表达与膀胱移行细胞临床病理特征无关。     

三次Pythagorean Hodograph 曲线在给定总弧长下的$G^2$拼接

Pythagorean-hodograph (PH)曲线因其在弧长和等距线计算方面的优势而被广泛应用于曲线建模中.本文讨论了在总弧长约束下的三次PH曲线$G^2$连续拼接问题.具体地说,给定两个端点和一个拼接点,构造两条三次PH曲线,使其在指定总弧长下插值两个端点,并且在连接点处是$G^2$连续的.这也可以看作是一个曲线延拓问题.根据三次PH曲线的弧长公式和$G^2$连续条件,最终将问题转化为了一个带有约束的极小值问题,同时我们给出了几个具体例子来说明该方法.     

一个结论与三个难题

我在课外书上看到这样一道几何题:如图1所示,在平行四边形ABCD中,两条邻边长分别为a、b,两条对角线长分别为m、n,试探求两条邻边长与两条对角线长之间的数量关系.     

一题三变看“弦长”

<正>圆的弦长问题是圆的重点内容之一.求弦长一般有两种途径:(1)代数法:即由弦所在的直线与圆的方程联立,求出弦两端点的坐标,然后利用两点间的距离公式求弦长(有时由根与系数的关系,设而不求,利用弦长公式求弦长);(2)几何法:由于弦心距、弦长的一半和圆的半径可以构成一个直角三角形,因此可借助于勾股定理(即几何法)求得弦长.下面结合例题对比学习这两种解题方法.     

多角度证明不等式一例

例题设a,b为直角三角形的两直角边的长,c为斜边的长,m,n为任意实数,求证:ma+nb/（m2+n2）^1/2≤c.方法一（综合法）证明:因为a,b为直角三角形的两直角边的长,c为斜边的长,所以a2+b2=c2.     

例析涉及三角形高线的数学竞赛题

三角形的高线是三角形中的重要线段,近年来涉及三角形高线的题目在多类数学竞赛中屡屡出现.本文采撷几例,分类进行解析.一、利用面积的不变性解题例1(2011年全国初中数学联合竞赛)已知△ABC的两条高线的长分别为5、20.若第三条高线的长也是整数,则第三条高线长     

一道椭圆问题的解法探究

<正>最近在研究直线与椭圆位置关系问题时,发现求弦长的问题解法颇多,与大家分享.题目已知直线l:y=x-1与椭圆C:x²/3+y2/3+y²/2=1交于A,B两点,求弦AB的长度.分析1这是一道弦长问题.可以直接求出A,B两点坐标,然后利用两点间的距离公式.     

188Pb形状共存的研究

用角动量投影壳模型研究了188Pb核素的形状共存.实验数据经过计算结果的分析,指出188Pb的低位激发态中存在着对应于不同内部粒子组态的球形基态、扁椭球和长椭球3种形状的共存;预言了质子h9/2两粒子-两空穴扁椭球带;指出长椭球带是两种多粒子-空穴组态的混合,推导出了混合系数.根据这些系数,说明中子i13/2对破裂引起的顺排对长椭球带的影响是一个渐进过程,指出了长椭球带2+态的能量范围为804～880keV.     

牵“相似形”之手,进“分类讨论”之园

<正>分类讨论是我们常用的一种数学思想方法.在数学题目中,有许多问题需要分不同情况加以考察,这就是分类讨论思想.其一般步骤是:(1)确定同一标准,(2)对全体对象进行分类,做到"不重,不漏",(3)分类讨论,得出结论.下面就相似形中的几个问题加以说明.一、由于对应边不确定,需要分类讨论例1要做两个形状相同的三角形框架,其中一个三角形框架的三边长为4、5、6,另一个三角形框架的一边长为2,问其余两边长是多少时,可使这两个三角形相似?思路点拨要使两个三角形相似,已知一个三角形的三边和另一个三角形的一边,则我     

岭回归估计的向量参数方法

本文提出岭回归估计的向量参数方法,选择均方误差函数的负梯度方向作为参数向量方向,根据均方误差与拟合误差的预期约束条件选择确定参数向量模长.文中获得了两个单调性结论,向量参数岭回归估计的均方误差是参数向量模长的单调减函数,而拟合误差是参数向量模长的单调增函数.基于两类误差的单调性结论,本文创建了关于两类误差的预期约束条件,预期条件约束下的向量参数岭回归方法有望成为兼备均方误差次优与拟合误差适度的双赢估计.文章最后是一个应用实例.     

Study on ride comfort of tractor with tandem suspension based on multi-body system dynamics

The aim of the paper is to report a systematic methodology which is used to evaluate and improve the ride comfort. An accurate model is necessary for further investigation and optimization. The vehicle dynamics model of tractor with tandem suspension is modeled and simulated in dynamics software ADAMS, which is redeveloped to add a function of automatic parametric modeling and simulation. The modeling methods of nonlinear characteristic components and various road excitation inputs, which can be simply seen as the implementation means for the model solution, are introduced. A new index called annoyance rate is presented to indicate the quantitative correlation between objective method and subjective comment. The quantitative correlation between them, which is quite different from the qualitative “comfortable” or “uncomfortable” results attained by objective evaluation, can be defined by function and regarded as a basis to scientifically evaluate and improve the ride comfort. According to the request of performance-based design, the parameter sensitive analysis and structure optimization have been carried out to find the trade-off among ride comfort, maneuverability and safety. The approach has proved to be very effective for predicting and improving the ride comfort by experiment results. The methodology can be also used for any other specific category of vehicle.     

最小度不小于3的图的圈长问题

Bondy和Vince曾证明最小度不小于3的图包含两个长度相差为1或者2的圈,这个结果回答了ErdSs提出的问题．Haggkvist和scott证明了除肠外,所有的3-正则图都包含两个长度相差2的圈．通过不同的方法,我们得到了下面的结论：除了每个端块都是硒的图外,所有最小度不小于3的图都包含两个长度相差2的圈．     

单调有界数列必有极限定理的一个直接证明及其作用

利用实数十进制无限小数表示直接构造性地给出"单调有界数列必有极限"定理的一种简洁的新证明,并且从新视角揭示数学分析中的实数完备性和高等数学中的数列极限存在准则.     

A methodology for estimating expected distances between nodes on a network

Transportation, distribution, and logistics professionals often need to estimate the distances that are used for the arc lengths between nodes on a network model. For example, a network model might be representative of roads and cities in which the actual distance from one city to the next may vary depending upon the actual source and destination within each of the respective cities. Hence, estimates for the arc lengths within the network model will contain error. This research presents two new models to estimate these inter-nodal distances for cases in which complete nodal representation of every source and destination is computationally prohibitive.     

Vibration control of active vehicle suspension system using fuzzy logic algorithm

Vehicle suspension along with tires and steering linkages is designed for safe vehicle control and to be free of irritating vibrations. Therefore the suspension system designs are a compromise between ride softness and handing ability. However, this work is concerned with a theoretical investigation into the ride behavior of actively suspended vehicles. It is based on using fuzzy logic control (FLC) to implement a new sort of active suspension system. Comparisons between the behavior of active suspension system with FLC with those obtained from active systems with linear-quadratic regulator (LQR), ideal skyhook system and the conventional passive suspension systems. Results are introduced in such a way to predict the benefits that could be achieved from a fuzzy logic system over other competing systems. Furthermore, a controller is designed and made by using results of FLC system, theoretical inputs are used to examine the validity of this controller. Moreover, comparison between actual outputs from this controller with those obtained theoretically is made to judge the validity of the controller. The results indicate that the controller has a good capability in simulation of the theoretical model.     

On the Joint Path Length Distribution in Random Binary Trees

During the 10th Seminar on Analysis of Algorithms , MSRI, Berkeley, June 2004, Knuth posed the problem of analyzing the left and the right path length in a random binary tree. In particular, Knuth asked about properties of the generating function of the joint distribution of the left and the right path lengths. In this paper, we mostly focus on the asymptotic properties of the distribution of the difference between the left and the right path lengths. Among other things, we show that the Laplace transform of the appropriately normalized moment generating function of the path difference satisfies the first Painlevé transcendent . This is a nonlinear differential equation that has appeared in many modern applications, from nonlinear waves to random matrices. Surprisingly, we find out that the difference between path lengths is of the order n ^5/4 where n is the number of nodes in the binary tree. This was also recently observed by Marckert and Janson. We present precise asymptotics of the distribution's tails and moments. We will also discuss the joint distribution of the left and right path lengths. Throughout, we use methods of analytic algorithmics such as generating functions and complex asymptotics, as well as methods of applied mathematics such as the Wentzel, Kramers, Brillouin (WKB) method.     

基于基尼系数的停车换乘拥挤收费定价模型

许多大城市提倡停车换乘的组合出行方式,目的是减少出行车辆,缓解交通拥挤状况.应用双层规划模型对停车换乘拥挤收费进行研究.下层模型采用弹性需求SUE模型,上层模型考虑了交通公平因素.以各出行方式占用的道路资源为公平指标,应用基尼系数对传统上层模型进行改造,构建一个用户盈余尽可能大而基尼系数尽可能小的上层模型,并利用基尼系数控制参数,实现在不同公平要求下的拥挤收费设计.算例表明,基于基尼系数的停车换乘拥挤收费设计,能改善道路的拥挤状况,且兼顾了用户盈余与公平.     

关于完全C＊置换子群

设H≤G,称H为G的完全C＊置换子群,如果对G的任意素数幂阶子群K,恒有x∈（H,K〉,使得HKx=KxH．本文利用素数幂阶子群的完全C＊置换性给出了一个群属于给定群系的的若干充要条件．     

Fuzzy multi-objective optimization of passive suspension parameters

The paper proposed a systematic and effective optimization process to optimize a 3-D vehicle suspension dynamic model with eight DOF, including seat vertical motion, suspension vertical, pitching and rolling motions and wheels vertical motions using fuzzy optimization, to attain the best compromise between ride comfort and vehicle-generated road damage. The results show a substantial improvement in the vertical ride quality is obtained while keeping the suspension deflections within their allowable clearance when the vehicle moves at a constant velocity v = 20m/s, and the comfort performance of a suspension seat can be considerably enhanced.     

中介数学系统已建立,为什么还会产生模糊数学危机

构造了两个例子,当试图用扎德的＂隶属函数＂的定义去表述例子中的模糊信息时发现,对于列举的例子,＂隶属函数＂的定义根本＂无法确切表达＂甚至根本＂无法表达＂其中所蕴含的模糊信息.进而发现,模糊数学危机产生的原因不是因为其基础理论不完善,而是因为某些定义在当初人们定义它时,定义的不准确造成的.所以要从根本上解决模糊数学的危机...