具动力边界和正初始能量的高阶波方程整体解的不存在性

讨论一类高阶非线性双曲方程整体解的不存在性.利用凸性分析方法,在方程具有边界条件和正初始能量情况下得到整体解不存在的充分条件.     

一类非线性积分方程连续解的存在性

研究了一类非线性分方程连续解的存在性与唯一性,给出了在不同条件下连续解的存在性与唯一性定理.     

一类三阶两点边值问题解的存在性

研究了一类三阶隐式微分方程两点边值问题解的存在性,利用上下解方法和迭代技巧得到了解的存在性结果.     

一类三阶两点边值问题解的存在性

文中研究了一类三阶隐式微分方程两点边值问题解的存在性,利用上下解方法和迭代技巧得到了解的存在性结果.     

一类源于各向异性板振动模型的四阶非线性椭圆偏微分方程解的存在性

研究非线性四阶椭圆边值问题解的存在性.该问题是作为一类刚性纤维编织材料的振动模型而提出的.运用上下解方法证明了上述方程解的存在性.     

基于中心流形的三维多项式微分系统极限环的存在性与稳定性

1963年,Sherman构造了三维多项式微分系统,并给出了周期解的存在性和稳定性条件.1989年,李德明等人用Liapunov-Schmidt reduction方法给出了此系统Hopf分支后周期解的存在性条件.本文将利用中心流形研究此系统极限环的存在性与稳定性.     

二阶隐式微分方程四点积分边值问题解的存在性

本文研究了一类二阶隐式微分方程四点积分边值问题解的存在性,利用上下解方法和迭代技巧获得到了解的存在性结果.     

两类分段对称系统周期解的存在性

本文研究了两类分段对称系统周期解的存在性,得到了系统相应的周期解存在的充分条件.作为应用,证明了一类具有分段对称性的时滞微分方程的周期解的存在性,推广了文[1]、[3]和[4]的有关结果.     

具源项和退化阻尼项的非线性波动方程解的整体不存在性

研究了非线性波动方程整体解的不存在性,该方程具有源项和退化阻尼项.通过构造不稳定集,利用常微分不等式证明了初始能量为正时整体解的不存在性.     

用强伪压缩映像不动点方法求解线性方程组

线性方程组理论是研究物资管理及其企业管理数量化的基本数学方法,线性方程组的研究包括解的存在性和计算方法两个方面.应用非线性泛函分析理论中非线性算子来研究线性方程组解的存在性和计算方法,而强伪压缩映像是一重要的非线性算子.应用强伪压缩映像的不动点方法研究线性方程组解的存在性和迭代计算方法,得到了相应的解的存在性定理和解的有效迭代计算方法.     

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.