伪脐点子流形的一个Simons型公式

研究了局部对称共形平坦黎曼流形的伪脐点子流形，得到了这种子流形有的一个Simons型公式，作为应用改进了S.T.Yau的一个相应结果。     

某些三维Hopf流形的性质

利用流形上漉和万有覆盖理论,构造了特殊Hopf流形上的一个叶状结构,并讨论了这个叶状结构与此流形上符合一定条件的函数的联系.另外,又证明了某类Hopf流形上不存在闭的(1,1)阶微分形式.     

局部对称共形平坦黎曼流形中的伪脐点子流形

研究了局部对称共形平坦黎曼流形的伪脐点子流形，得到了这种子流形的一个内蕴积分不等式，从而推广改进了B.Y.Chen一个相应结果。     

判定局部共形Khler流形为Vaisman流形的若干定理

利用覆盖映射和局部共形Khler流形理论,证明了满足某些条件的局部共形Khler流形一定为Vaisman流形的若干定理.如:Lee向量场为一个群S(eit,t∈R)作用诱导下的向量场一定为Vaisman流形.同时文中也给出判断Vaisman流形的若干充要条件.     

伪黎曼流形上的Simons型不等式

f:Mn→Npn+p(c)是n维黎曼流形到n+p维伪黎曼流形Npn+p的等距浸入.通过计算Ricci张量长度平方的拉普拉斯算子,得到了伪黎曼流形上的一个Simons型积分不等式.     

判定局部共形K(a)hler流形为Vaisman流形的若干定理

利用覆盖映射和局部共形K(a)hler流形理论,证明了满足某些条件的局部共形K(a)hler流形一定为Vaisman流形的若干定理.如:Lee向量场为一个群S(eu,t∈R)作用诱导下的向量场一定为Vaisman流形.同时文中也给出判断Vaisman 流形的若干充要条件.     

伪黎曼流形中具有平行第二基本形式的子流形

讨论了伪黎曼流形中具有平行第二基本形式的类空子流形,得到了它的第二基本形式模长平方有界的一个拼挤条件,推广了已有结论.     

伪黎曼流形中具有平行第二基本形式的子流形

讨论了伪黎曼流形中具有平行第二基本形式的类空子流形,得到了它的第二基本形式模长平方有界的一个拼挤条件,推广了已有结论.     

局部对称共形平坦黎曼流形中伪脐子流形

研究了局部对称共形平坦黎曼流形中紧致的伪脐子流形,给出了一个Simons型积分不等式.将[1,2]中的积分不等式推广到局部对称共形平坦黎曼流形中的伪脐子流形.     

弱阻尼Schrodinger方程的近似惯性流形

1.引言 对于耗散发展方程而言,描述非稳定永久流的动力学性质的一个最自然的工具是引入整体吸引子,这方面已有大量的文献。对惯性流形的研究,使人们更加深入地研究耗散系统。这些流形是光滑的有限维不变流形,它们包含了整体吸引子,当时间趋于无穷时,它指数吸引所有解,把发展方程限制在惯性流形上考虑时,它将变为一个有限维的常微分方程,从而完全地描述了耗散发展方程的长时间性态。这种流形的存在性结果可参见〔1〕,〔2〕等。但是仍有许多耗散的偏微分方程的惯性流形的存在性还未知,甚至在某些情况下不存在惯性流形。同时,尽管惯性流形比吸引子的计算更为满意,但它们的计算仍是一个艰难的工作。     

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.