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1.
蜻蜓目昆虫既是天敌昆虫,又是药用和食用的资源昆虫,并且是研究"古翅类"系统发育关 系极好的实验材料.综述了我国蜻蜓目昆虫的研究进展,着重从分类文献专著、区域性分布调查研 究、生物学特性研究、形态结构研究、生态应用研究、稚虫方面的研究、细胞分子生物学等几个方面 作了比较系统的总结.  相似文献   

2.
爬行动物血细胞研究进展(二)   总被引:1,自引:0,他引:1  
综述了爬行动物血细胞-红细胞,有粒白细胞、淋巴细胞,单核细胞,浆细胞和血栓细胞的组织化学特性,血细胞数量及变化规律等方面的研究进展,并简要地讨论了我国开展血细胞研究的必要性,可为深入研究提供参考资料。  相似文献   

3.
昆虫的血细胞的命名和分类目前意见尚不一致,由于各人使用的染色方法不同,昆虫种类的差别,及离体血细胞在形态上易于变化等因素,使这个工作显得更困难,Yeager(1945)将Prodenia eridania(Cramer)的血细胞分为10个类型32种。Lichman(1946)(据Wiggle-sworth 1949)研究了昆虫和其他无肴椎动物之后,认为起源于同一干细胞的血细胞仅有二种:1.吞噬细胞(类淋巴细胞),2.非吞噬细胞。Wigglesworth(1959)将血细胞分为四种:1.原始血细胞,2.吞噬细胞,3.非吞噬细胞,4.类绛色细胞。Jones(1962)综述了昆虫血  相似文献   

4.
从研究方法,明渠紊流拟序结构,泥沙运动与床面形态,拟序结构与泥沙运动和拟序结构与床形态等方面,总结了近年来国内外有关研究进展,在展望了研究趋势后,提出今后应该进行更加精细的实验研究,加深对拟序结构与泥沙运动相互作用的理解。  相似文献   

5.
 从基因编辑技术在昆虫毒理学研究中的应用、杀虫剂作用机制及抗性机制研究、昆虫抗药性的分子调控机制研究、昆虫毒理相关的基因组学研究等方面,综述了2017年昆虫毒理学的主要研究进展,并展望了昆虫毒理学研究的新方向、害虫抗药性治理的新策略。  相似文献   

6.
额神经节是昆虫神经系统中的重要结构,它参与昆虫的羽化、蜕皮等多种生理行为的调节,在昆虫的生理生态中发挥重要的作用。研究额神经节的神经网络结构及功能对理解昆虫的生理学机制有重要科学意义。综述近年来关于额神经节研究的最新研究成果及进展,围绕额神经节神经网络的结构和功能展开,主要论述了额神经节的解剖学位置、形态结构、组织发育、神经元的种类、运动神经元的类型、与其他神经组织的联系的神经网络结构以及调节昼夜节律、控制前肠肌的自律性运动、控制蛋白质的新陈代谢和调控心跳等的各种生理功能。并提示额神经节可能是一个内分泌器官,通过分泌神经调节因子发挥作用,对其神经机制的进一步研究将是额神经节今后的研究方向和发展趋势。  相似文献   

7.
RAPD技术在昆虫分类学研究中的应用   总被引:1,自引:0,他引:1  
传统昆虫分类学主要从昆虫形态特征着手,是进行昆虫分类的主要方法,但形态分类的方法在较低的分类阶元中有着较大的局限性.近年来分子生物学技术同传统分类学方法相结合,在昆虫分类学研究中得到广泛的应用.本文概述了随机扩增多态性DNA(RAPD)技术的技术基础,分析了PAPD简便快捷、费用低、灵敏度高、对模板纯度要求不高、能充分反映模板的多态性等技术优势;同时指出了该技术稳定性和可重复性差、不能对纯合体杂合体加以区分、存在共迁移问题等不足之处;阐述了近年来国内外RAPD技术在同翅目、蜚蠊目、双翅目、鳞翅目、直翅目、鞘翅目等昆虫的分类鉴定及昆虫系统发育分析中的应用.本文认为,PAPD技术扩展了分子生物学技术在昆虫分类学的应用范围,该技术的成功应用,极大地提高了昆虫分类学研究的水平,并且随着技术手段的不断进步有着更为广阔的应用前景.  相似文献   

8.
大头金蝇的生物学及其在法医昆虫学上的应用   总被引:1,自引:0,他引:1  
大头金蝇Chrysomya megacephala(Fabricuis)是一种重要法医昆虫、媒介昆虫、传粉昆虫和资源昆虫。综述了大头金蝇的生物学、生态学特点,包括大头金蝇在国内外总体分布情况,各虫态形态特征、发育历期和环境因子对其生长发育的影响。重点综述了大头金蝇在法医昆虫学中推断死后间隔时间(Postmortem Interval, PMI)的应用,包括种类鉴定,生长发育中日龄指标的选定。另外,简要回顾了其作为媒介昆虫、传粉昆虫和资源昆虫方面的研究进展。最后对今后的研究提出了建议。  相似文献   

9.
氮化铁的制备及其在磁记录和磁流体中的应用进展   总被引:6,自引:0,他引:6  
综合介绍了近年来纳米氮化铁材料在制备方法、结构和性能以及应用方面的研究进展,提出了今后的研究及改进方向。  相似文献   

10.
昆虫化学生态学与植物保护   总被引:10,自引:0,他引:10  
在生态安全条件下进行植物保护,推行植物免害工程是实现可持续发展的有效途径之一。笔综述了昆虫化学生态学中昆虫与植物之间、昆虫与天敌间的化学联系,信息素与植物挥发性物质在昆虫对寄主植物定位、定居、取食和繁殖中的作用,非寄主植物对植食性昆虫寄主选择的影响等领域的研究进展,以及利用植物次生性化合物进行害虫治理的应用现状。展示了昆虫化学生态学在未来植物保护中的应用前景及昆虫化学生态学的研究方向。  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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