局部积流形的半不变子流形

本文讨论了局部积流形的半不变子流形，得到了关于这类子流形的微分几何方面的一些重要结果．     

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。     

局部对称黎曼流形的伪脐点子流形

研究了局部对称黎曼流形的伪脐子流形，得到了这种子流形的一个内蕴刚性定理，从而推广了献[3]中的结果。     

一类流行病模型的奇异流形和分岔

利用微分方程定性理论，研究了一类基于家庭检测和追踪的最小流行病模型的奇异流形的存在性和稳定性，给出了奇异流形存在性和稳定性的充要条件，讨论了在奇异流形附近发生的非参数跨临界分岔，同时利用Matlab进行数值模拟，验证了基本再生数大于或小于1时流形的稳定性.     

局部积流形的超曲面

研究了局部积流形的超曲面，给出了局部积流形的超曲面为一个P-Sasakian流形的充分必要条件，     

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.     

关于接触流形及其辛化

研究了接触流形的性质，它的辛化以及辛流形的接触化．     

黎曼流形上的Toponogov定理在Finsler流形上的推广

在Finsler流形上利用活动标架法，通过沿某一方向提升，获得了弧长第二变分的表达式。将黎曼流形上的Toponogov定理推广到Finsler流形上，由此可进一步将黎曼几何中与之有关的一些定理进行推广而无须通过繁杂的张量运算。     

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.     

Leibniz流形上的几种运算

通过Leibniz代数的理论来研究Leibniz流形上的运算.首先验证了Leibniz流形上分级张量代数是Leibniz代数,然后由Leibniz代数理论给出Leibniz流形上的三种运算及其性质,为深入研究Leibniz流形理论提供了运算工具,从而进一步完善了Leibniz流形的理论。     

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.