具有阶段结构和饱和治疗的SIS模型的动力学性态

该文研究了一类具有阶段结构的SIS传染病模型,包括：定义了模型的基本再生数：讨论了模型的无病平衡点和地方病平衡平衡点的存在性;证明了无病平衡点和地方病平衡点的局部渐近稳定性;发现了饱和治疗会引起后向分支。     

一类具有饱和治愈率和饱和接触率的流行病动力学模型研究

主要建立了一类带有饱和治愈率和饱和接触率的SIRS传染病模型,研究得到了该模型的无病平衡点及地方病平衡点的局部稳定性,同时,借助构造Liapunov函数,给出了无病平衡点和地方病平衡点全局渐近稳定的条件.     

肺部免疫应答模型的稳定性分析与分支分析

考虑肺部感染初始先天系统反应的动态模型,首先根据三次多项式方程根的判别式,得到了模型有正平衡点的条件,其次利用平衡点稳定性理论和中心流形定理讨论了在该条件下模型正平衡点的具体类型及稳定性,最后考虑了在平衡点处出现的鞍结点分支.     

具有非线性传染率和垂直传染结构的SIRS模型的稳定性分析

讨论了一类带有非线性传染率和垂直传染结构的SIRS模型,给出了模型的阑值定理,分析了平衡点的稳定性,证明了疾病消除平衡点和地方病平衡点的全局渐进稳定性.     

具有心理因素影响的SVIR传染病模型的稳定性分析

研究了一类具有心理因素影响的传染率函数和有医疗限制的治疗函数的SVIR传染病模型。讨论了模型平衡点的存在性,计算了基本再生数,通过Hurwitz判据得到无病平衡点和地方病平衡点的局部稳定性,用构造Lyapunov函数的方法证明无病平衡点的全局稳定性,最后利用第二加性复合矩阵判断地方病平衡点的全局稳定性。     

具有充分接种和共同感染两种病毒的流行病模型分析

在充分接种的假设下,分析具有共同感染两种病毒的流行病模型,得到了基本再生数和侵入再生数的表达式,在一定的条件下,给出了模型的无病平衡点和边界平衡点,并证明了无病平衡点和边界平衡点的稳定性.     

一类时滞HIV模型的Hopf分支

研究了一类带时滞的HIV病毒的CD4＋细胞模型及它的平衡点的稳定性,当该模型满足一定条件时,它的平衡点稳定,当平衡点不稳定时研究了Hopf分支的存在性.     

具有分布时滞的恒化器模型的动力学分析

本文建立具有一般功能反应函数和分布时滞的恒化器模型。首先证明了模型解得正性和有界性,然后计算得到基本再生数,分析了细菌灭绝平衡点、无感染平衡点和正平衡点的存在的条件。通过构造Lyapunov函数,得到细菌灭绝平衡点、无感染平衡点的全局稳定性。     

考虑潜伏期和免疫反应的HIV模型的动力学分析

本文建立了具有C-M发生率及潜伏期的HIV传染病模型。为了能更好的描述免疫反应对感染的影响,模型中采用更为一般的免疫产生率。计算得到基本再生数及免疫再生数,分析了无病平衡点,无免疫平衡点及免疫平衡点的存在性及唯一性。通过构造Lyapunov函数,得到无病平衡点,无免疫平衡点及免疫平衡点的全局稳定性。     

具McCulloch—Pitts型双阈值二元离散神经网络模型解的渐近性

本文研究了具McCulloch-Pitts型非线性双阈值二元离散神经网络模型平衡点的动力学性质.对给定的阈值范围,通过作变换把其平衡点的稳定性转化为零解的稳定性,证明了模型平衡点是全局指数渐近稳定的.     

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.