一类初等算子的范数等式

讨论了B(H)上初等算子Δ_(A,B)的范数等式,其中Δ_(A,B)(X)=AXB+XB(∨X∈B(H)),给出了‖I+Δ_(A,B)‖=1+‖A‖‖B‖+‖B‖成立的一个充分必要条件.     

不等式A1/p·B1/q≤A/p+B/q的推广

不等式A1/pB1/q≤A/p+B/q是一个重要的不等式.本文将这一不等式推广到一般情况,并指出一般平均值不等式是这一(推广)不等式的特例.     

Hardy-Littlewood极大算子的一个推广

本文在Lp(X,dμ)上定义非对称范数‖f‖p,(α,β),并在此基础上给出了非对称范数意义下Hardy-Little-wood极大算子的性质.     

关于HLDER不等式及MINKOUSKI不等式

Hlder不等式及Minkow ski不等式是建立L~p空间和l~p空间的理论基础,有了这两个不等式,才能在L~p空间和l~p空间中引出具有普遍意义的范数来。 引理 若p>1,1/p+1/q=1,则对于任意A≥0,B≥0,有下列不等式 AB≤A~p/p+B~q/q (1) 证明 当AB=0时,不等式(1)显然成立。 当AB≠0时,考虑函数φ(x)=x~p/p+1/q-x(x≥0),由于,φ′(x)=x~(p-1),因此φ′(x)在x<1时,小于零,在x>1时,大于零。故φ(x)在x=1达到最小值0。即对任一x≥0,φ(x)≥0。令x=AB~(-p/q),则A~pB~(-q)/p+1/q-AB~(-p/q)≥0,以B~q乘以上式并注意到q-q/p=q(1-1/q)=1,即得(1)式 注1 (1)式只有在A~p=B~q时等号成立。 注2 当p=q=2时,这时(1)变成显然等式AB≤A~2+B~2/2 一、关于H(?)lder不等式 若p>1,1/p+/q=1,则有 1、H(?)lder不等式的级数形式:对于任意p幂收敛复数列{§k},q幂收敛复数列     

一个有趣的三角不等式的类比与推广

文[1]给出了如下不等式:在△ABC中,有cosA.cos~2B/2cos~3C/3≤27/64①.经类比探究,笔者得到了一个上述不等式的"姊妹不等式":在△ABC中,有sinAsin~2B/2sin~3C/3≤1/64②,当A=B/2=C/3时等号成立.证明∵sinAsinB/2=-1/2[cos(A+b/2)-cos(A-B/2]     

关于矩阵值Lipschitz映射空间的若干研究

引入并研究了由紧的距离空间(K,d)到Mm,n(F)中的Lipschitz-α映射构成的空间Lα(K,Mm,n(F))和lα(K,Mm,n(F));并证明了它们关于范数‖f‖α=‖f‖∞ Lα(f)是Lipschitz空间;得到了lα(K,Mm,n(F))是Lα(K,Mm,n(F))的闭子空间;当0<α≤β≤1时,Lβ(K,Mm,n(F))是Lα(K,Mm,n(F))的闭子空间.     

30分钟智力冲浪

1.数p是10,12,q这3个数的平均数的23倍,则用含p的式子表示q是().(A)23p-22(B)43p-22(C)2p-22(D)2p 112.解关于x的方程a6x a=2 3x.3.若关于x的方程||x-2|-1|=m有三个整数解,则m的值是().(A)3(B)2(C)1(D)04.若关于x的方程m(x-m) n(x n)=0有无穷多个解,则m,n应满足的关系是.5.a,b,     

数学奥林匹克高中训练题（109）

第一试 一、选择题(每小题6分,共36分) 1.对于满足0≤p≤4的一切实数p,不等式x2 px>4x p-3恒成立.     

Banach空间中有界线性算子的 Drazin逆的扰动分析

设X是一Banach空间.B(X)表示X→X的有界线性算子全体构成的向量空间.T∈B(X),指标为k且R(Tk)闭,T=T+δT为T的扰动,记TD为T的Drazin逆,则在R(δT)(∈)R(Tk),N(δT)(∩)N(Tk)及△=‖TD‖‖δT‖＜1的条件下,有(-TD)-TD的简明分解式及相应的误差估计.此外还给出了(-TD)的一个与Tk+有关的表达式.作为应用,讨论了算子方程Tx=u(u∈R(TD))的解的扰动界.     

鞅p-均方函数的B-G-D双Φ-不等式

设定义在[0,∞）上Φ1,Φ2是凸函数,对于鞅的p-均方算子和极大算子,当Φ1,Φ2满足一定条件时,证明Burkholder-Gundy-Davis不等式关于Φ1,Φ2的Orlicz范数不等式,并通过构造具体的鞅说明这个条件是充分的．     

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?     

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…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

The Reader Response Approach to Teaching of English Literature

During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context.