东方杯叶吸虫精巢和精子发生的超微结构研究

本文应用透射电镜研究了东方杯叶吸虫精巢和精子的超微结构及精子发生过程,并与体外培养成虫进行比较,提出一种精子结构模式图.精子的形成经历了由精原细胞,初级精母细胞、次级精母细胞、精子细胞和精子的发育等过程.精子细胞形成后,胞质突起形成一分化区,并发育成精子鞘,核向鞘中旋转、浓缩和迁移,两根鞭毛轴丝由鞘中基体发出;鞭毛为9+“1”结构.体外培养成虫尚有几种不正常的成熟精子,可作为体外培养的评价指标.     

短尾鮠精子发生的超微结构研究

用透射电镜观察了短尾鮠的精原细胞、初级精母细胞、次级精母细胞、精子细胞和精子的形态以及细胞核、拟染色体和线粒体等的结构变化规律．结果表明：精原细胞时期细胞器较丰富，到精子细胞后期，细胞器的形态和数量发生了较大变化；随着精母细胞的发育，核质凝聚程度逐渐增强．短尾鮠的精子具有椭圆的头部和复杂的中片，近侧中心粒和远侧中心粒靠近核的中央，鞭毛呈9＋2轴丝结构，并具有由外膜折迭形成的波浪形的结构．表明短尾鮠精子发生中具有某些区别于其它鱼类精子的不同结构．     

孔雀鱼精子发生的显微与超微结构

对卵胎生硬骨鱼孔雀鱼精子的发生进行了显微与超微结构研究.成鱼精巢呈肾形,腹面有输精管伸出,内部构造为小管型.孔雀鱼精子发生经过精原细胞,初级精母细胞,次级精母细胞,精子细胞及变态精子阶段;初级精母细胞和精子细胞高尔基体和囊泡丰富;从精母细胞到精子细胞有细胞质不完全分裂现象;成熟精子头部较长,袖套部分长度是头部的2倍,直径与精子头部相同,线粒体多.鞭毛有侧鳍,其轴丝为典型的“9+2”结构.     

赤点石斑鱼精子发生和形成的超微结构研究

用透射电镜研究了赤点石斑鱼Epinephelus妇精子发生和精子形成过程。结果表明，赤点石斑鱼精子发生经历了初级精原细胞、次级精原细胞、初级精母细胞、次级精母细胞、精子细胞阶段。精子细胞再经过精子形成过程成为精子。在初级精原细胞、次级精原细胞阶段，细胞核释放出拟染色体。拟染色体分布于精原细胞和前期Ⅰ的初级精母细胞的细胞质中。初级精母细胞减数分裂早期同源染色体配对明显可见，并形成联会复合体。精子细胞之间存在细胞联系（桥粒）。赤点石斑鱼成熟精子的特点是细胞核圆形，核内染色质致密，没有核泡（核空隙）。精子尾部细长，横切面为典型的“9＋2”轴丝结构。     

瓦氏黄颡鱼精巢发育及精子生物学研究

瓦氏黄颡鱼精巢呈栉状分支，每一分支内部结构为叶型，精巢小叶由许多壶腹状的精小囊组成，精巢发育分为精原细胞增殖期、精母细胞生长期、精母细胞成熟期、精子细胞变态期、精子成熟期和精子退化吸收期，精子的发生和形成经历了精原细胞、精母细胞、精子细胞到成熟精子的一系列过程，精巢后1／3的精巢尾区由上皮细胞构成，既无生精功能也无贮精作用，成熟精子在0.45％～0.55％盐溶液和pH7.5的弱碱性的自然河水环境中保持的活性最好，并具有相当长的寿命。     

日本弓背蚁精子发生观察

对日本弓背蚁(Camponotusjaponic)精子的发生动态过程进行了连续观察和描述.精母细胞形态和细胞核形态变化特征性指标显示:日本弓背蚁精子发生过程总体可分为5个阶段:精原细胞时期、初级精母细胞时期、次级精母细胞时期、精子细胞时期和精子形成时期,最终成熟的精子通过交配活动排出体外.     

蟋蟀雄性生殖系统的结构和精子发生

研究了蟋蟀雄性生殖系统的结构和精子发生的动态过程 .成熟的雄性生殖系统主要由一对精巢 ,一对输精管 ,一对附腺 ,一对储精囊和一根射精管组成 .精巢乳白色由许多精巢管盘曲组成 ,精巢管包括原精区、生长区、成熟区和变形区四个区域 .其主要特点是处于不同发育时期的精母细胞呈放射状密集排列在圆球形的育精囊中 .精子发生的动态是 :一龄期 ,精巢小管仅具一些精原细胞 ;二～三龄期 ,精原细胞不断通过有丝分裂增殖 ;四龄期 ,初级精母细胞形成 ,并由减数分裂形成次级精母细胞 ;五龄期 ,精细胞大量形成 ,并变形成为精子 .其主要特点是成虫期的精巢管中存在所有各期生殖细胞 ,当下端的精子成熟时 ,上端部分的精母细胞再发育形成精子 ,表明从五龄开始蟋蟀便能连续不断地产生精子     

合浦珠母贝精子发生过程的超微结构观察

报道了透射电镜下合浦珠母贝精子发生过程超微结构的观察结果。描述了精子发生过程中线粒体，中心体（鞭毛），顶体泡和细胞核的演变过程。精子细胞核内染色质以颗粒状形式凝集，精子核呈圆桶状，圆形的顶体泡迁移到顶体部位后变形成为圆锥形顶体。合浦珠母贝精子经过精度原细胞，精母细胞和精子细胞，最终发育成为成为成熟的精子，成熟的精子由头部（长约２μｍ），中段（长约０．６８μｍ，宽约１．６μｍ）和尾部（长约５０－６０     

大瓶螺精子发生的超微结构研究

用透射电镜研究了大瓶螺精子发生中精原细胞,初级精母细胞,次级精母细胞,精细胞,精子超微结构特点及精细胞变态为精子的过程,成熟精子由头部和尾鞭两部分组成,头部包括顶体复合物和核,尾鞭可分为中段和尾段,中段有线粒体鞘螺旋围绕在轴丝外面,尾鞭中心的轴丝具9＋2微管结构。     

鳜精巢的组织学和超微结构观察

对鳜精巢的组织学结构和超微结构进行观察．鳜精巢呈叶型结构,由精原细胞、初级精母细胞、次级精母细胞、精细胞、成熟精子等生殖细胞和支持细胞、间质细胞、边界细胞、类肌细胞、成纤维细胞、内皮细胞等非生殖细胞组成．鳜精子形成过程,精细胞大致经历了鞭毛发生,核质凝缩及核位置的改变,线粒体迁移等过程．鳜成熟精子无顶体结构,头短而圆,主要为核占据,核凹窝发达,尾细长,具侧鳍,尾部轴丝为“9 2”结构．     

Markedness and its Interpretation in Language Use

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.     

Features of Women's language

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

Achieving Unusual States of Matter Under High Pressure

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-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the