查询词典 null function

We also define two families of functions, named a torus height functionand an AdS-distance-squared function respectively, and use them to investigate thesingularities of the AdS-null surfaces and the torus Gauss images as applications ofsingularity theory of functions.

作为函数奇点理论的应用，利用这两个函数族来研究AdS-null曲面和环面高斯像的奇点。

In this thesis, we find that dlg is indispensible in the establishment of anterior-posterior and dorsal-ventral polarity of drosophila oocyte. Removal of Dlg function from the posterior follicle cells using the FLP/FRT system leads to disruption of oocyte skeleton reconstruction that is elicited by the failure of those posterior cells to differentiate normally in mid-oogenesis. We demonstrate that abnormity of Notch, JAK-STAT and EGFR signal pathway in dlg mutants contributes to this aberrant differentiation. dlg null mutant also blocks the normal differentiation of two groups of anterior follicle cell-stretched cell and centripetal cell, but not border cell, with a lower penetrance. However unlike the result in posterior follicle cells, Notch and JAK-STAT signaling are both undisrupted in all mutant anterior follicle cells, implying other fate determinants may be involved.

我们的研究发现，后端滤泡细胞中的Dlg在果蝇卵子发生中期卵母细胞前后轴和背腹轴建立过程中也是必须的，PFC中dlg完全缺失型突变引起PFC的分化异常，导致卵子发生中期卵母细胞骨架重组异常，Stau、Grk等极性决定蛋白定位错误。dlg突变阻碍了Notch、JAK-STAT、EGFR等调节PFC分化的信号通路的激活。dlg突变的PFC也没有获得前端滤泡细胞命运。dlg突变不影响前端滤泡细胞群中边界细胞的分化，但是在一定程度上影响伸展细胞和向心细胞的分化，并且这种影响不依赖于前端滤泡细胞Notch或JAK-STAT信号激活的异常。

Background— Protein kinase A signaling has long been known to play an important role in cardiac function. Dysregulation of the protein kinase A system, caused by mutation of the protein kinase A regulatory subunit gene PRKAR1A, causes the inherited tumor syndrome Carney complex, which includes cardiac myxomas as one of its cardinal features. Mouse models of this genetic defect have been unsatisfactory because homozygote null animals die early in development and heterozygotes do not exhibit a cardiac phenotype.

背景——蛋白激酶A信号传导在心功能中发挥了重要作用早已为人们所知蛋白激酶A调节亚基因PRKAR1A的变化引起蛋白激酶A系统失调，导致了遗传性卡尼复合肿瘤综合症，其中包括的心脏粘液瘤作为它的一个主要特征此种遗传缺陷的小鼠模式仍然不能令人满意，因其纯合体空白动物在发展中早期死亡，而杂合体不能显示心脏表型

Perutz M F Structure and Function of Haemoglobin Journal of Molecular Biology , 1965,null

王耀萍%潘冀%牛秀田我国第二次空间蛋白质晶体生长实验中国科学C辑， 1996，2

While the standard Airy function, used frequently in the uniform asymptotic formulas for classical orthogonal polynomials, behaves like the exponential function on one side and the trigonometric functions on the other side of an extreme zero,the q-Airy polynomial behaves like the q-Airy function on one side and the q-Theta function on the other side.

在经典正交多项式的一致渐近公式中我们通常要用到Airy函数，这个Airy函数在一个极端零点的一边表现为指数函数，另一边又表现为三角函数。同样地，q-Airy多项式在一边表现为q-Airy函数，另一边又表现为q-Theta函数。

This paper compares periodic set with almost periodic set, and properties of periodic function with that of almost periodic function through analysing the definitions of periodic function and almost perodic function, and then draws some important conclusions.

利用周期函数与概周期函数的定义，把周期函数的周期集与概周期函数的概周期集进行了比较，把周期函数与概周期函数的性质进行了比较，并得出一些重要结论。

A main feature in developing the theory is that the scope is expanding: from almost periodic function, asymptotically almost periodic function, weakly almost periodic function to pseudo almost periodic function which was introduced by Professor Zhang in 1992. Every extension consumedly enlarges the theory and their applications.

从概周期函数、渐进概周期函数、弱概周期函数，一直到张传义教授在上世纪九十年代初提出的伪概周期函数，每一次函数范围的扩展都大大地丰富了概周期函数的理论和其应用前景。

Methods 42 children with CP (26 males, 16 females, average age 49.5±21.5 months, 11 children with spastic quadriplegia, 22 with spastic diplegia, 5 with spastic hemiplegia, 2 with athetosis and 2 with dystonia) were assessed with Gross Motor Function Classification System and Gross Motor Function Measure for the assessment and classification of gross motor function. Pediatric Evaluation of Disability Inventory PEDD was used to assess the ADL. The ADL of children with different levels of GMFCS and the correlat ion between gross mot or function and ADL were analyzed. Results The more severe of GMFCS, the less standard score of PEDI.

方法对 42例脑瘫患儿（男性26例、女性16例，年龄49.5±21.5个月；痉挛型四肢瘫11例、痉挛型双瘫22例、痉挛型偏瘫5例、徐动型2例、肌张力障碍型2例）采用脑瘫粗大运动功能分级系统和粗大运动功能测试量表进行粗大运动功能分级和评估；采用能力低下儿童评定量表进行日常生活能力评定，分析不同GMFCS等级脑瘫患儿的日常生活能力表现，以及粗大运动功能与日常生活能力之间的相关性。

Events,Operation and Relation of Sets, Classical Probability, Geometrical Probability , Statistical Stability of a Frequency, Axioms of Probability, Conditional Probability, Total Probability Theorem, Bayes' Rule,Independent Events,Independent Repeated Trials, One Dimensional Random Variables, Discrete Random Variables, Distribution Function of a Random Variables , Continuous Random Variables, Normal Distribution, Distribution of a Function of a Random Variable, Multidimensional Random Variables, Joint Distribution Function, Marginal Distribution Function,Discrete Two—Dimensional Random Variables,Continuous Two—Dimensional Random Variables, Independent Random Variables, Distribution of Functions of Random Variables,Expectation,Variance, Covariance, Coefficient of Correlation, Bivariate Normal Distribution, Law of Large Numbers, The Central Limit Theorems, Sample and Population ,Chi—Squared, T and F Distributions , Sampling Distributions , Point Estimation , Interval Estimation , Testing Hypotheses , A Test of Significance for Parameters in a Single Sample From a Normally Distributed Population , A Test of Significance for Parameters in Two Sample From Normally Distributed Populations .

本课程的主要内容：概率的概念与运算、随机变量及其分布、随机变量的数字特征与极限定理、数理统计的基本概念、估计和检验的基本方法，随机事件与概率随机事件、事件的关系与运算、几何概率、统计概率等，条件概率、全概率公式、贝叶斯公式、事件的独立性、二项概率公式，随机变量的概念、离散型随机变量、随机变量的分布函数、连续型随机变量、随机变量函数的分布，多维随机变量及其分布函数、边缘分布函数、随机变量的独立性、二维随机变量函数的分布，数学期望、方差、协方差和相关系数、大数定律、中心极限定理，总体与样本， X 2-分布、 t-分布和 F-分布，统计量及抽样分布，假设检验的基本概念、单个正态总体参数的显著性检验、两个正态总体参数的显著性检验。

Second, in the viewpoint of crypto analysis, the practical requirement for the cryptographic function is to construct the function that can resist all the known crypto analysis and attacks. In advanced, the main cryptographic properties are compared, and the relation among these cryptographic properties is analyzed, including the trade-off ones. Get the conclusion that the construction of cryptographic Boolean function is to find out the proper Boolean function in the whole vector space under the restriction of several cryptographic properties required for the security system.

然后本文从密码分析的角度，讨论了密码函数的实际需求，即构造能够抵抗已有密码分析与攻击的布尔函数；分析了布尔函数的主要的密码学性质，并比较了这些性质之间的相互关系，包括制约的关系；得出了构造布尔函数的实质的结论，即在向量空间中构造全体布尔函数，以所需的若干密码学性质作为限制条件，用有限域上的多项式、Walsh谱、Hadamard矩阵等数学工具找出适当的布尔函数用于加密体制的设计。

A backer of an Afghan law that critics say legalizes marital rape has rejected the international outcry as foreign meddling.

饱受批评的一项法律的拥护者说合法化的婚内暴力不会受国际舆论的干涉。

Years ago, a ancient Egyptian fleet went to the Land of punt for seeking a kind of flavor named "myrrh", and aromatic plants which has dense exotic style for the queen Hatshepsut.

3500年前的一个古埃及的舰队到&彭特之地&寻找一种叫没药的香料。