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1.
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。  相似文献   

2.
本文运用生化测定、放射性同位素标记及显微放射自显影等技术方法研究了灭幼脲Ⅰ号对致倦库蚊DNA代射的影响。结果表明,灭幼脲Ⅰ号抑制了致倦库蚊的DNA合成,降低DNA含量。  相似文献   

3.
分析了厦门地区常见的三种蚊虫─—迷走库虫(Culexvagansi)、白纹伊蚊(Aedesal-bopictus)和雷氏按蚊(Anopheleslesteri)染色体核型,三种蚊虫的染色体二倍体数都是2n=6,迷走库蚊与白纹伊蚊的Ⅰ、Ⅱ、Ⅲ号染色体全部都是中部着丝粒,而雷氏按蚊的Ⅰ号染色体为亚中部着丝粒,Ⅱ号与Ⅲ号染色体为中部着丝粒。从核型分析来看,白纹伊蚊的染色体最长大,迷走库蚊次之,雷氏按蚊最短小  相似文献   

4.
为确定多裂叶荆芥有丝分裂过程及核型情况,以唇形科植物多裂叶荆芥(Nepeta multifida(L.)Briq)为材料,采用常规压片制片法进行多裂叶荆芥有丝分裂过程观察,并对有丝分裂中期染色体进行核型分析研究。结果表明:多裂叶荆芥在有丝分裂间期→前期核膜先消失,继而核仁消失;在后期→末期核膜的形成早于核仁。有丝分裂中期染色体核型公式为2n=2x=12=12sm(2SAT),其中第2对染色体短臂具随体。多裂叶荆芥所有染色体均为亚中部着丝粒染色体,核型类型为2A型,属于基本对称型。  相似文献   

5.
本文首次报道亚洲玉米螟Ostrinia furnacalis Guenée(Lepidoptera:Pyralidae)的染色体核型。试验采用了压片法、空气干燥法和HSG显带法,观察并研究了亚洲玉米螟精巢中精母细胞的减数分裂和有丝分裂。五龄中期幼虫是减数分裂观察的最佳时期。染色体单倍体数目n=31,呈大小不等的小棒状或点状,有主缢痕。核型性别不明,性别决定机制不清。文中还对亚洲玉米螟精母细胞分化为精子过程中的各个分裂时期做了描述。  相似文献   

6.
氟化钠对洋葱根尖细胞有丝分裂的影响   总被引:1,自引:0,他引:1  
用不同浓度的氟化钠溶液,分别处理洋葱根尖,发现在有丝分裂的细胞中,出现了滞后染色体、染色体桥和多极化现象。有些细胞中还出现了微核。同时,在实验中还观察到,随着溶液浓度的增加和染毒时间的延长,细胞增殖率下降,有丝分裂指数递减。  相似文献   

7.
观察了雄菜粉蝶生殖细胞细胞分裂的染色体,并对其G带核型进行了研究。染色体制片采用涂片法,G带显示采用尿素法。结果表明:2n=50,染色体上无明显的着丝粒,有丝分裂早中期染色体上显示了较为清晰的带纹,依据染色体的相对长度和G带带纹,排出了G带核型。  相似文献   

8.
本文报道了高粱染色体G—显带核型的研究.实验结果表明,供试材料有丝分裂早中期相的每条染色体均显示多重的G—带带纹.根据带纹着色深浅和粗细,可分为两种不同类型的带纹,即深色粗带和浅色细带.在同源染色体之间,带纹特征及其数目相同,而在非同源染色体之间,则互有差异.本文对高粱染色体的核型和染色体G—带带型进行了分析,并对G—显带在高粱核型分析及其它研究中的应用、ASG显带方法等问题进行了讨论.  相似文献   

9.
草间小黑蛛的核型   总被引:1,自引:0,他引:1  
报道了草间小黑蛛的核型,包括染色体数目、形态结构和性染色体组成.材料采自石家庄市郊区.细胞学数据主要来自对混合胚胎细胞有丝分裂中期的观察.实验结果表明:草间小黑蛛细胞的染色体数是雄体细胞2n=24,雌体细胞2n=26,性别决定机制为X1X2O系统.X染色体为全部染色体中最小的和次最小的一个(对).对其C-显带标本观察表明,所有染色体均为端或亚端着丝粒染色体,每个染色体都有其特点.  相似文献   

10.
镉对蒜根尖细胞分裂的影响   总被引:2,自引:0,他引:2  
蒜小鳞茎在不同浓度的镉溶液中处理24-48小时后,观察到随着Cd浓度的递增或培养时间的延长,根尖细胞有丝分裂的指数下降,分裂细胞异常率增高,分裂细胞异常主要表现为低毒的染色体C-有丝分裂,染色体桥等。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

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