热传导方程有限差分逼近的数学Stencil及其新型迭代格式

将Stencil应用于偏微分方程有限元差分逼近过程，以两类差分格式为基础建立了求解热传导方程的两种新型迭代算法.此两种算法与经典的Jacobi方法同样具有并行的性质，但比Jacobi方法收敛快.给出的算例说明方法的适用性.     

关于两类复微分-差分方程组的超越解

利用复差分方程和复微分方程理论,讨论两类复微分-差分方程组的有限级超越整函数解问题,得到两个结果。     

带有小参数的抛物型方程的多过渡点差分格式

讨论两类时间上带有小参数的抛物型方程,介绍了多过渡点的选取方法,依此法构造不等距差分格式并证明新的差分格式关于摄动参数是一阶一致收敛.多过渡点差分格式的收敛阶与Bakhvalov法相同,高于Shishkin网格法,但计算量比Bakhvalov法小得多,在实际应用中相当有效.     

一类n阶差分方程边值问题的多解性

利用twin solution不动点定理与Lcggett-Williams不动点定理对一类n阶差分方程边值问题分别进行了讨论,得到该问题有两解与三解的结果．其中本文所讨论的n阶差分方程边值问题比以往讨论的该类问题要一般（本文方程中非线性项允许含有直到n-2阶差分）．     

关于差分方程(组)两类问题的探讨

<正> 本文在对差分方程(组)两类问题的探讨中,给出了非定常差分方程组零解稳定性的两类反例的简捷构造法;提供了n阶常系数非齐次线性差分方程特解的简便求法。一、非定常差分方程组零解稳定性的两类反例的简捷构造法对于定常差分方程组零解的稳定性已有定论,即系数矩阵的特征根若都在单位园内,则其零解渐近稳定;若特征根在单位园内外都有,则其零解不稳定。而对于非定常差分方程组,其系数矩阵一致有界,那么非定常差分方程组是否有类似结果吗?回答是不一定的。文1]给出了反例的一种构造公式,并用公式举出了具体例子。但这种公式化的构造方法较烦,     

两类高阶高次非线性差分方程的精确解

利用独立通解法(UGS)研究2类非线性差分方程的精确解,得到了一类非线性齐次差分方程的精确解,它由若干个独立通解共同构成,且独立通解的个数与差分方程的阶数n和方程的次数m的乘积mm无关;还得到了一类非线性非齐次差分方程的一组特解.     

差分方程的不变子空间

研究了差分方程的不变子空间,讨论了多项式形式的子空间及三角函数型的子空间,并将这两类不变子空间运用到了拟线性演化方程和方程组。得到了以下结果:若已有的微分算子允许某一类不变子空间,则对应的差分方程也允许相应的不变子空间,且其系数满足一样的动力系统。     

奇摄动抛物型方程的一致收敛差分格式

讨论两类奇摄动抛物型方程,构造相应的拟合网格差分格式,并证明差分格式关于小参数是一致收敛,数值例子显示数值解很好地逼近精确解．     

一类二阶非线性差分方程的振动性

差分方程反映的是关于离散变量的变化规律.通过分析方程解的特别性质,可以把握离散变量的变化过程的规律.方程的振动性是研究方程定性理论的重要组成部分,从理论上探讨解的形态变化一直是近年来研究的热点.文章对已有文献中的线性差分方程进行了改进,研究了更普遍的方程,一类二阶非线性多时滞差分方程打振动性,利用分析的方法及积分中值定理,得到了该类方程振动的几个充分条件,并且应用差分方程的振动理论,研究了这类方程在特殊情形下解的一价差分的振动性,得到了一阶差分振动的充分条件,从而丰富了这类方程的研究成果.     

求解广义KdV方程的非标准有限差分格式

对广义KdV方程建立了非标准有限差分格式,并给出了该格式的局部截断误差.数值结果表明,在相同条件下非标准有限差分格式比标准有限差分格式局部误差小,且保持了原方程本身所具有的守恒性.     

氯胺酮在蚊媒感染实验中的应用

目的　了解受疟原虫感染的实验猴肌注氯胺酮后供蚊吸血 ,氯胺酮是否会影响疟原虫在蚊体内的发育。方法　给已感染疟原虫的供血猴肌注氯胺酮之前及之后 ,各供大劣按蚊吸血一批 ,于吸血后第 9天 ,解剖蚊胃 ,第 12天解剖唾腺 ,观察卵囊和子孢子发育情况 ,共作了 5个不同剂量的重复实验。结果　各对照组和用药组之间 ,卵囊和子孢子感染阳性率无差别 ,均为 10 0 % ,卵囊感染密度和卵囊平均大小及子孢子平均感染度均无显著性差异 (P>0 1)。结论　给受疟原虫感染猴肌注氯胺酮后供蚊吸血 ,不影响疟原虫在蚊体内的发育 ,还能提高蚊媒吸血效果 ,缩短实验时间     

Harmonic synchronization model of the mating dengue vector mosquitoes

When two mosquitoes meet to mate, each modulates its flight tones such that the female’s 3rd and the male’s 2nd harmonic frequencies are equivalent. We show that this phenomenon is an example of synchronization, which is common in nature. The mosquito’s flight tone acts as an external signal, stimulating its partner to adjust the wing beat rhythm to achieve the synchronization state. A simplified model, which is based on the frequency ratio difference feedback mechanism, is proposed to describe the harmonic convergence of mosquitoes. Furthermore, we proposed a method to characterize the energy dissipation in the frequency alteration, and the results demonstrate that 3/2 frequency locking is an optimal selection to mosquitoes. When compared with other possible ratios, the mosquitoes expend minimum energy if they lock the synchronizing state at a ratio of 3/2.     

具有发育阶段结构的野生与不育蚊子交互作用的数学模型

Using the sterile insect technique,in which sterile mosquitoes are released to reduce or eradicate the wild mosquito population,is an effective weapon to prevent transmission of mosquito-borne diseases. To study the impact of the sterile insect technique on the disease transmissions,we formulate stage-structured discrete-time mathematical models,based on difference equations,for the interactive dynamics of the wild and sterile mosquitoes. We incorporate different strategies for releasing sterile mosquitoes,investigate the model dynamics,and compare the impact of the different release strategies.Numerical examples are also provided to demonstrate dynamical features of the models.     

具有发育阶段结构的野生与不育蚊子交互作用的数学模型（英文）

Using the sterile insect technique,in which sterile mosquitoes are released to reduce or eradicate the wild mosquito population,is an effective weapon to prevent transmission of mosquito-borne diseases. To study the impact of the sterile insect technique on the disease transmissions,we formulate stage-structured discrete-time mathematical models,based on difference equations,for the interactive dynamics of the wild and sterile mosquitoes. We incorporate different strategies for releasing sterile mosquitoes,investigate the model dynamics,and compare the impact of the different release strategies.Numerical examples are also provided to demonstrate dynamical features of the models.     

大理学院校园内蚊类的组成及分布

目的：调查和了解大理学院校园内蚊类的组成及分布，为大理州蚊类研究及蚊媒疾病的防控提供流行病学依据。方法：以大理学院古城和下关校区校园为调查点，选择校园内蚊虫孳生地和人群密集区为采样点，采用紫外灯诱捕法对夜间活动的成蚊进行通宵取样，对所捕成蚊进行分类、计数和统计分析。结果：共捕获成蚊619只，隶属2属11种。其中，库蚊属Culex7种，按蚊属Anopheles4种。捕获成蚊中以致倦库蚊Cx．qsuinqueascitus为优势蚊种（占捕蚊总数的87．72％），以三带喙库蚊民．tritaeniorhynchus为较常见蚊种，其他蚊类数量均较少。结论：致倦库蚊为大理学院校园内的优势蚊种。     

187菌株灭蚊有效成份的研究

本文对187菌株灭蚊有效成份进行了研究。结果表明:187菌株的伴孢晶体对蚊幼虫有较高的毒力;滤液与芽孢无毒力;高浓度未形成晶体与芽孢的菌体(培养11小时),虽有较低毒力,但死亡速度缓慢。     

Robust and regulatory expression of defensin A gene driven by vitellogenin promoter in transgenic Anopheles stephensi

The use of genetically modified mosquitoes to reduce or replace field populations is a new strategy to control mosquito-borne diseases. The precondition of the implementation of this strategy is the ability to manipulate the genome of mosquitoes and to induce specific expression of the effector molecules driven by a suitable promoter. The objective of this study is to evaluate the expression of defensin A gene of Anopheles sinensis under the control of a vitellogenin promoter in transgenic Anopheles ste- phensi. The regulatory region of Anopheles gambiae vitellogenin was cloned and subcloned into transfer vector pSLFa consisting of an expression cassette with defensin A coding sequence. Then, the expression cassette was transferred into transformation vector pBac[3xP3-DsRedafm] using Asc I di- gestion. The recombinant plasmid DNA of pBac[3xP3DsRed-AgVgT2-DefA] and helper plasmid DNA of phsp-pBac were micro-injected into embryos of An. stephensi. The positive transgenic mosquitoes were screened by observing specific red fluorescence in the eyes of G1 larvae. Southern blot analysis showed that a single-copy transgene integrated into the genome of An. stephensi. RT-PCR analysis showed that the defensin A gene expressed specifically in fat bodies of female mosquitoes after a blood meal. Interestingly, the mRNA of defensin A is more stable compared with that of the endogenous vitellogenin gene. After multiple blood meals, the expression of defensin A appeared as a reducible and non-cycling type, a crucial feature for its anti-pathogen effect. From data above, we concluded that the regulatory function of the Vg promoter and the expression of defensin A gene were relatively con- served in different species of anopheles mosquitoes. These molecules could be used as candidates in the development of genetically modified mosquitoes.     

Ultra-prolonged activation of CO2-sensing neurons disorients mosquitoes

Carbon dioxide (CO(2)) present in exhaled air is the most important sensory cue for female blood-feeding mosquitoes, causing activation of long-distance host-seeking flight, navigation towards the vertebrate host and, in the case of Aedes aegypti, increased sensitivity to skin odours. The CO(2) detection machinery is therefore an ideal target to disrupt host seeking. Here we use electrophysiological assays to identify a volatile odorant that causes an unusual, ultra-prolonged activation of CO(2)-detecting neurons in three major disease-transmitting mosquitoes: Anopheles gambiae, Culex quinquefasciatus and A. aegypti. Importantly, ultra-prolonged activation of these neurons severely compromises their ability subsequently to detect CO(2) for several minutes. We also identify odours that strongly inhibit CO(2)-sensitive neurons as candidates for use in disruption of host-seeking behaviour, as well as an odour that evokes CO(2)-like activity and thus has potential use as a lure in trapping devices. Analysis of responses to panels of structurally related odours across the three mosquitoes and Drosophila, which have related CO(2)-receptor proteins, reveals a pattern of inhibition that is often conserved. We use video tracking in wind-tunnel experiments to demonstrate that the novel ultra-prolonged activators can completely disrupt CO(2)-mediated activation as well as source-finding behaviour in Aedes mosquitoes, even after the odour is no longer present. Lastly, semi-field studies demonstrate that use of ultra-prolonged activators disrupts CO(2)-mediated hut entry behaviour of Culex mosquitoes. The three classes of CO(2)-response-modifying odours offer powerful instruments for developing new generations of insect repellents and lures, which even in small quantities can interfere with the ability of mosquitoes to seek humans.     

三带喙库蚊和致倦库蚊实验感染流行性乙型脑炎病毒的研究

目的：探讨流行性乙型脑炎病毒对我国三带喙库蚊和致倦库蚊的易感性。方法：用乙型脑炎病毒（Nak株）经口和胸腔接种感染实验室养殖的三带喙库蚊和致倦库蚊，应用空斑实验方法检测蚊虫体内的病毒存在情况和病毒滴度。结果：经口感染的两种库蚊，共计19组，有14组发生感染，空斑形成单位在3．18～4．7910gPFH/ml；在胸腔接种的两种库蚊中，致倦库蚊在10^0-10^-5稀释滴度时发生感染，最高PFU为6．59 logPFU／ml，三带喙库蚊在10^0-10^-4稀释滴度时发生感染，最PFU为5．74 logPFU／ml。结论：三带喙库蚊和致倦库蚊均对乙型脑炎病毒高度易感，胸腔接种的易感性高于经口感染。     

Transgenic anopheline mosquitoes impaired in transmission of a malaria parasite

Malaria is estimated to cause 0.7 to 2.7 million deaths per year, but the actual figures could be substantially higher owing to under-reporting and difficulties in diagnosis. If no new control measures are developed, the malaria death toll is projected to double in the next 20 years. Efforts to control the disease are hampered by drug resistance in the Plasmodium parasites, insecticide resistance in mosquitoes, and the lack of an effective vaccine. Because mosquitoes are obligatory vectors for malaria transmission, the spread of malaria could be curtailed by rendering them incapable of transmitting parasites. Many of the tools required for the genetic manipulation of mosquito competence for malaria transmission have been developed. Foreign genes can now be introduced into the germ line of both culicine and anopheline mosquitoes, and these transgenes can be expressed in a tissue-specific manner. Here we report on the use of such tools to generate transgenic mosquitoes that express antiparasitic genes in their midgut epithelium, thus rendering them inefficient vectors for the disease. These findings have significant implications for the development of new strategies for malaria control.