一类带有出生和死亡密度制约的携带病毒不育控制模型

建立一类带有出生和死亡密度制约的携带病毒不育控制模型,讨论了系统平衡点的稳定性,得到全局渐近稳定的条件。分析了参数对害鼠种群数量的影响,提出了有价值的控制策略。     

具有阶段结构的不育控制害鼠模型

着重讨论了一类具有阶段结构的非自传播的不育害鼠模型,分析了各个平衡点的局部渐近稳定性,并给出各平衡点全局渐近稳定的数值模拟,讨论了不育比例β对于种群规模的影响。     

不育控制下的害鼠种群的动力学分析

建立了具有密度制约的不育种群的动力学模型,从理论上探讨各平衡点存在性及稳定性,并讨论了不育控制中各个参数对种群动态的影响。     

一类状态脉冲不育控制的单种群模型

建立了一类状态反馈脉冲控制的不育单种群模型,当害鼠的数量达到经济危害水平时,通过灭杀,从而控制种群数量的增长。首先利用微分方程几何理论和后继函数的方法得到系统阶1周期解得存在性,并给出了阶1周期解得渐近稳定性的充分条件。     

不育控制下的单种群动态

简单介绍了利用不育技术控制有害动物的研究现状,建立了不育控制下的单种群模型,分析了模型的动态,并讨论了不育率和移除率在控制有害动物中作用的异同。     

出生和死亡都具有密度制约的不育控制竞争模型

主要讨论了一类一种群出生和死亡都具有密度制约的不育控制下的竞争模型,得到了系统平衡点的存在条件,证明了平衡点的局部渐近稳定性和全局稳定性,最后给出了全局稳定的数值模拟。     

免疫不育控制下的种群动态分析

建立了以病毒为媒介的不育种群动力学模型,从理论上探讨各平衡点存在性,并通过构造Liapunov函数,Dulac函数等证明了各平衡点的全局稳定性。     

珠江三角洲稻作区农田害鼠的复合防治指标研究

采用混合损失模型法研究了珠江三角州稻作区农田害鼠的复合防治指标．结果表明，不同鼠类对水稻的危害程度不同，板齿鼠对水稻的危害最大．其次为黄毛鼠，小家鼠对水稻的危害较小．防治适期各种害鼠的种群密度与当季水稻的产量损失率呈多元钱性相关．并建立了害鼠复合防治指标检索表．     

两个种群共进化的志愿者困境模型

介绍两个种群共同进化机制下的志愿者困境模型,即两个种群之间的多个体志愿者博弈模型,通过复制动态方程组来研究模型在无限种群时的确定进化动态,分析平衡点的稳定性.     

人类活动影响下麻雀种群动态分析

利用系统理论讨论人类活动影响下麻雀种群动态关系，得到如下结论：麻雀种群的唯一平衡点是0，自然种群及人类活动影响下麻雀种群的年际波动周期均为3年，人为等非常因素致使麻雀种群趋于灭照的条件是其杀亡率k>1-1／(1 e)(1 e-∞)(1 e-e0e-e0e0e),其中e为麻雀种群周限增长率，e1、e0是麻雀种群相关时期的集群率和扩散率．     

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.