用复合算子刻画的一族解析函数

引进用复合算子定义的一族解析函数B(λ,σ,α,β)和与Robertson函数有关的一类解析函数族R(α,β).先用在单位圆内解析函数族A上的三个算子来研究B(λ,σ,α,β),得到积分表达式、包含关系、极值点、偏差定理;并讨论实部不等式和积分平均等性质.同时推出B(λ,σ,α,β)与R(α,β)之间的关系,由此导出中函数的相应结果.     

一类固定设计方差函数模型的小波估计

考虑非参数方差模型Yi=σ(xi)εi,i=1,2,…,n,其中xi是固定设计点列,{εi}是严平稳α-混合序列.该文利用小波方法构造了方差函数σ2(x)的估计量,在设定的假设条件下,讨论了其小波估计的有偏性、方差和相合性.     

函数观点在解题中的应用（三）——用函数观点求动点轨迹方程

求动点轨迹方程主要有四种方法:直角坐标法;极坐标法;参数方程法;运用常用图形的轨迹方程的方法.本文讲述如何利用函数观点来建立动点的极标方程和参数方程.1 用函数观点求动点的极坐标方程 建立动点的极坐标方程关键在于:找出动点的极角θ与极径r之间的关系.如何找θ,r之间的关系呢?常用的思路是,联系几何图形,应用函数观点来分析,看一看任意给定θ,如何决定出r.然后把这个思路用数学语言表示出来,就得所要的解法.     

关注直线参数方程中参数的几何意义

<正>笔者在平时的教学中发现,学生普遍对直线参数方程中参数的几何意义理解得不透彻,现总结如下.直线的参数方程是由直线经过的定点和其倾斜角确定的,经过点P_0(x_0,y_0),倾斜角为α的直线的参数方程为{x=x_0+tcosα,y=y_0+tsinα(t为参数).我们通常把直线参数方程的这种形式称之为直线参数方程的标准式.一、对直线l参数方程中的参数t的深层     

特殊二元三角方程的解法探讨

我们不妨把含有两个未知角的三角方程称为二元三角方程。这类方程构思奇巧,常规解法难以奏效,对训练学生思维的灵活性和独创性很有益处。本文列举数例,介绍此类问题的几种处理方法。1 直接运用函数的有界性例1 求满足3sin2α=3 cos~2(3β)的锐角α、β的值。分析:观察方程知,左边的最大值是3,右     

关于约数和函数的一个方程

对于正整数k,设σ(k)是k的约数和函数.本文运用初等数论方法证明了:方程σx(1+[y/x])+σy(1+[x/y])=2·3 [(x+y)/2]仅有正整数解(x,y)=(t,t),其中t是任意正整数.     

直线参数方程的妙用

现行中学数学课本中,以例题的形式求出了经过点P(x_0,y_0),倾斜角为α的直线l的参数方程 x=x_0 tcosα (t为参数)(*) y=y_0 tsinα但没有介绍其应用.然而笔者发现,此参数方程能在多种场合收到神奇的解题效果.在数学过程中,尤其在总复习时,应予以重视. 一、有利于化简计算参数方程(*)的一个重要特征是参数的两个系数的平方和为1,即cos~2α sin~2α=1.我们称(*)为直线参数方程的标准形式.在这种形式下,参数t有着明显的几何     

对直线参数方程及其应用的分析

我们知道,参数方程是解析几何中的一个难点,而直线的参数方程及其应用又是该章节的重点,因此,深刻系统全面地对直线的参数方程及其应用进行分析是十分必要的.在平面直角坐标系中,经过定点P_0(x_0,y_0),倾角为α(0≤α≤π)的直线(如图)的参数方程是x=x_0 tcosα y=y_0 tsinα其中t是参数.它的几何意义是:|t|的大小等于定点P_0(x_0,y_0)到动点P(x,y)的距离,而t表示有向线段P_0P的数量,P点在P_0点的上方t为正,P点在P_0点的下方t为负.     

用H~σ算子定义的一类解析函数的Fekete-Szeg问题

本文引进了一个用Hσ算子定义的解析函数类V（σ,α,μ）,并讨论了该函数类的Fekete-Szeg问题得到了准确值.     

方程中的函数思想与函数中的方程观点

方程与函数是中学数学的重要知识点 ,又是高考和竞赛的热点 .许多方程问题常常可以运用函数思想去解决 ,而不少函数问题又往往须转化为方程来求解 .因此 ,在解决一些函数和方程问题时 ,既要善于运用函数思想解决方程问题 ,又要学会灵活运用方程的观点去观察、处理函数问题 .本文举例说明如下 :1　方程中的函数思想例 1　已知实数 ｐ、ｑ满足方程ｌｇ(ｌｏｇ3ｐ) =ｌｇ(2- ｑ) +ｌｇ(ｑ + 1) ,求 ｐ的取值范围 .简解　一个等式 ,两个变量 ,故可将 ｐ表示成 ｑ的函数 ,从而转化为求函数的值域 .原方程等价于ｌｏｇ3ｐ =(2 - ｑ) (ｑ+ 1) ,即 …     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

Western and Eastern culture differences in commercial field

The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

风的曲线

Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.