矩阵模型在稻纵卷叶螟预测预报中的应用

根据稻纵卷叶螟迁入量数据和生命表资料,提出矩阵模型模拟卷叶螟种群动态,预测发生期,并试图预报发生量,预报防治适期.模型预报田间发生期是准确的.预报发生量仍需改进.     

稻纵卷叶螟的数据库管理系统

以dB ASEⅢ建立了稻纵卷叶螟的数据库管理系统。本系统容易查向和检索害虫管理的资料,也便于从数据库中提取数据,进行运算和作图。最后列举了应用的实例.     

稻纵卷叶螟—水稻生态系统的模拟及分析

稻纵卷叶螟—水稻生态系统包括如下成份:卷叶螟,水稻,自然天敌,天气,管理措施。根据系统成份的分析,建立了该系统的模拟模型,包括:卷叶螟Leslie矩阵模型,发育率模型、产卵模型,水稻生长发育预测模型,叶面积及产量损失模型,日温度变化模拟模型。系统模拟结果表明:系统对成虫期和5龄幼虫期比较敏感.捕食天敌和极端天气对系统影响很大,采用化学防治措施虽然可以降照当代虫口密度,但下代种群数量反而增加。系统验证结果基本符合田间实际情况.     

稻纵卷叶螟的经济损害水平和经济阈值

以室内接虫、剪叶模拟以及田间调查等方法研究稻纵卷叶螟的为害对水稻产量的影响.初步确定了该虫在综合防治区的经济损害水平为39条幼虫/百丛(剑叶期)和58条/百丛(分蘖期).并提出用害虫种群潜在密度确定卷叶螟经济阈值的方法.     

鲁山县粮食作物重要害虫发生特点研究

对鲁山县不同气侯类型的粮食作物重要害虫粘虫、地下害虫、小麦沟牙甲、小麦吸浆虫、稻纵卷叶螟、二化螟、玉米螟等的发生特点进行了系统的研究,为农作物害虫的防治提供了依据.     

鲁山县粮食作物重要害虫发生特点研究

对鲁山县不同气侯类型的粮食作物重要害虫粘虫、地下害虫、小麦沟牙甲、小麦吸浆虫、稻纵卷叶螟、二化螟、玉米螟等的发生特点进行了系统的研究，为农作物害虫的防治提供了依据。     

稻纵卷叶螟综合管理决策

以净收益最大作为最优的管理目标,提出了稻纵卷叶螟的临界管理决策模型和多阶段综合管理的决策模型.讨论了不同虫口密度,不同的市场价格,不同的约束条件以及水稻不同生长时期对决策的影响.结果表明:当卷叶螟幼虫密度为10000—15000条/亩,采取‘杀虫单’根施是最优的;当田间成虫密度为500—1000头/亩,欲控制下代种群密度低于当代水平,则最优的控制方案是在成虫期采取诱杀,卵期释放赤眼蜂,幼虫期自然防治,蛹期田间浸蛹等农业措施.     

稻纵卷叶螟一个DELTA家族谷胱甘肽S-转移酶基因的克隆、序列分析与表达模式

谷胱甘肽S-转移酶（glutathione S-transferases ,GSTs）在昆虫代谢各种内源和外源性有害化合物的过程中起关键作用。重要水稻害虫稻纵卷叶螟（Cnaphalocrocis medinalis）的GST基因目前尚无研究。本实验克隆了一个稻纵卷叶螟delta家族GST基因的全长cDNA序列,命名为CmGSTd3（Genbank登录号KM433686）。CmGSTd3包含681 bp的开放阅读框,编码一个由226个氨基酸组成的蛋白。CmGSTd3蛋白是一个胞质GST ,与已知的昆虫delta家族GST 具有较高的同源性。在系统进化分析中,CmGSTd3与家蚕的delta家族GST聚在同一进化分支上。实时荧光定量PCR结果显示,CmGSTd3基因在稻纵卷叶螟幼虫阶段表达量最高,且主要表达于幼虫的中肠和脂肪体,由此推测其可能参与了体内异源毒物的代谢。本研究为探索CmGSTd3的生理功能奠定了前期基础。     

稻纵卷叶螟实验种群模拟模型

通过5种温度处理(19℃,22℃,25℃,28℃和31℃),探讨稻.卷叶螟实验种群的数量动态.25℃度温度处理组的世代存活率最高(19.7%),种群增长指数最大(14.9倍)。上述两项指标最低的是19℃温度处理组,分别为3.59b和1.18.根据实验结果,组建了该虫实验种群生命表,并建立了模拟种群数量变化的连续模型和等龄期结构的矩阵模型。     

稻纵卷叶螟nAChRs的分子特征及对杀虫剂的响应

烟碱型乙酰胆碱受体(nAChRs)是脊椎动物和无脊椎动物中的主要兴奋性神经递质受体.在昆虫中,nAChRs是杀虫剂的重要分子靶点,如新烟碱类和多杀菌素.在此研究中,根据稻纵卷叶螟(Cnaphalocrocis medinalis)转录组数据库和生物信息学方法鉴定两个稻纵卷叶螟nAChRs基因(Cmα8和Cmα9).Cmα8和Cmα9的开放阅读框(ORF)分别由1,650和999个核苷酸组成,这两种基因都具有nAChR家族成员的典型特征.系统发育树分析显示,Cmα8与丽蝇蛹集金小蜂(Nasonia vitripennis)的Nvα8同源性最高,Cmα9与家蚕Bombyx moriα9(Bmα9)的同源性最高.组织表达模式分析表明两个基因在中肠和脂肪体中高度表达,在蛹和成虫阶段,Cmα8和Cmα9的表达量最高,最低的表达量则位于幼虫阶段.此外,吡虫啉在中肠中显著诱导Cmα8和Cmα9的表达,而在脂肪体中则没有明显变化.综上所述,本文将为理解稻纵卷叶螟(C.medinalis)中nAChRs的功能提供有用的信息.     

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.