蛇鮈的产卵习性及胚胎发育

蛇　每年３～４月产卵，产卵下限温度１２℃．产卵环境特点：微流水，底质为卵石和沙质的浅水河滩．集群产卵，繁殖群体的性比为♀：♂＝８：１．卵微粘性，卵径１．０～１．１ｍｍ，比重略大于水．在水温１５．０～１８．３℃条件下，观察了胚胎及胚后发育过程：受精后１ｈ６ｍｉｎ，胚盘形成；再过２５ｈ４ｍｉｎ后，胚孔封闭．从受精到孵化历时８１～８２ｈ，初孵仔鱼全长４．５ｍｍ．孵出后第１０ｄ，卵黄囊消失，全长６．４ｍｍ．讨论了蛇　卵的类型和配对方式等问题     

蛇Ju的产卵习性及胚胎发育

蛇Ｊｕ每年３－４月产卵，产卵下限温度１２℃，产卵环境特点：微流水，底质为卵石和沙质的浅水河滩，集群产卵，繁殖群体性比为♀：♂＝８：１，卵微粘性，卵径１．０－１．１ｍｍ，比重略大于水，在水温１５．０－１８．３℃条件下，观察了胚胎及胚后发育过程，：受精后１ｈ６ｍｉｎ，胚盘形成；再过２５ｈ４ｍｉｎ后，胚孔封闭，从受精到孵化历时８１－８２ｈ，初孵仔鱼全长４．５ｍｍ，孵出后第１０ｄ，卵黄囊消失，全长６．４ｍ     

粗唇鮠生物学的初步研究

１９９１年１０月至１９９２年７月，在嘉陵江下游采集粗唇标本２１１尾，进行了生物学性状的测量和统计运算．用胸鳍棘脱钙切片法鉴定年龄．体长与棘切片半径呈直线正相关．渔获物中８０％为２龄和３龄鱼，雌鱼的体重和肥满度均较同体长的雄鱼高．粗唇属一次性产卵的鱼类，产卵期为５～７月，雌鱼性成熟最小型为２龄，体长１０．６ｃｍ，体重２２．２ｇ．绝对繁殖力为１３７２（５８３～２３９２）粒，且与体长、体重、年龄和成熟系数成正相关。受精卵卵径２．０～２．２ｍｍ．强粘性．在２６．５～３０．５℃的水温下，经５０小时４２分孵出．初孵仔全鱼长５．２～５．８ｍｍ．     

花鲈胚胎发育的研究

描述了人工繁殖的花鲈胚胎的发育过程。花鲈的卵为圆球形、浮性，吸水膨胀后卵径为１．３８￣１．５１ｍｍ；大多具１￣２个油球，少数具３￣４个油球。在温度为１２．２￣１４．０℃、盐度为２２‰的天然海水中，花鲈胚胎发育历时的８６小时孵出仔鱼。胚胎发育分为５个阶段，共３０个发育期。     

暗纹东方鲀胚胎发育的观察

详细记叙了暗纹东方　胚胎发育各阶段的形态特征及早期发育的生物学资料．暗纹东方　的卵为沉性卵，入水后具粘性，其粘度与受精效果有关．卵径为１．１１８～１．２７４ｍｍ，具油球２８０～３９０个，油球径为０．０２６～０．０７８ｍｍ．作者采用连续法对受精卵的发育进行观察．在水温１８．７～２１．２℃时，受精卵历时１３９ｈ１０ｍｉｎ开始孵出仔鱼．其发育过程划分为３５个时期．本研究可为开展暗纹东方　的人工育苗提供必要的参考资料．     

The Effects of Different Culture Systems on the Quality of Bovine In Vitro Fertilized Embryos

研究探讨了不同体外培养条件下牛体外受精胚胎的发育速度及囊胚细胞数，从而了解不同体外培养系统对牛体外受精胚胎质量的影响．实验一中将体外受精卵分别在ＳＯＦ＋牛输卵管上皮细胞（ＢＯＥＣ）和ＴＣＭ１９９＋ＢＯＥＣ两种培养系统内培养，在这两种培养条件下囊胚发育率分别为２２．２％和２１．２％，囊胚细胞数分别为１１３．３±５．０和９７．９±８．３，受精后第６～９ｄ的囊胚出现率分别为４０．１％ａ、３７．０％、１９．２％ｂ、２．７％和１３．５％ｃ、３２．７％、３６．５％ｄ、１７．３％（ａ＞ｃ，Ｐ＜０．０１，ｄ＞ｂ，Ｐ＜０．０５），表明牛体外受精卵在ＳＯＦ＋ＢＯＥＣ中的发育速度快于在ＴＣＭ１９９＋ＢＯＥＣ中．实验二中将体外受精卵分别培养于ＳＯＦ＋ＢＯＥＣ、ＳＯＦ＋牛卵丘细胞、ＳＯＦ＋ＢＳＡ三种培养系统中，结果囊胚发育率分别为３５．５％ｅ、２９．４％和２２．４％ｆ（ｅ＞ｆ，Ｐ＜０．０１），囊胚细胞数分别为１１７．３±８．０ｇ、９４．２±９．３和９０．２±９．４ｈ（ｇ＞ｈ，Ｐ＜０．０５）．实验三观察了体外受精胚胎在ＳＯＦ＋ＢＯＥＣ培养条件下发育速度与囊胚细胞数的关系，结果第６～９ｄ的囊胚细胞数分别为１１０．８±１０．２ｉ、１２８．     

鲂鱼_Megalobramaskolkovii_早期发育的研究

卵圆球形，浅绿色，具粘性，卵径１．１－１．２毫米，在水温３０．６－３１．４℃情况下，受精卵经２２小时４５分钟后孵化出膜．眼、嗅囊、耳石和心脏搏动均出现在孵出之前，初孵仔鱼全长４．０－４．７毫米，肌节４１－４２对，在水温２５．２－３３．６℃情况下，出膜后５天卵黄囊全部被吸收，１２天后腹鳍条形成，３０天后形态发育完全，全身被鳞，接近成鱼形态．     

河川沙塘鳢的胚胎和胚后发育以及温度对胚胎发育的影响

本文描述了河川沙塘鳢的胚胎和胚后发育以及温度与胚胎发育的关系。根据外形和内部主要特征，将胚胎发育分为３０个发育期。在胚胎发育期间，许多器官分化形成，至孵化时，胚胎已具有较完善的内部器官，各鳍亦已形成。胚后发育以卵黄囊的消失和鳞被的形成为依据，划分为仔鱼期、稚鱼期和幼鱼期。胚后发育不经过浮游生活期。在自然水温中，胚胎约经２１天发育孵出仔鱼。胚胎发育的最高临界温度为３０．０℃，最低临界温度为１０．０℃，适宜温度范围为１５．０～２７．０℃，其中２１．０～２７．０℃为胚胎发育的最适温度范围。     

大弹涂鱼受精卵孵化技术

在水温２３．０－２８．０℃,盐度２０．８－２３．５,ＰＨ８．０－８．１的条件下,大弹涂鱼受精卵经９６ｈ胚胎发育后开始孵出仔鱼,孵化时间延长至１６８ｈ。人工授精卵在筛绢网上上的平均孵化率为４．２－２０．５％;在塑料桶内的平均孵化率为３６．３％－７０．６％。     

盐度对秋冬季生殖真鲷的胚胎发育和仔鱼成活的影响

本研究采用不同盐度的海水，以秋冬季生殖真鲷的受精卵和仔鱼为材料，观察不同盐度下真鲷的受精卵的沉浮性；不同盐度对胚胎的孵化时间和孵化率的影响；不同盐度下仔鱼的分布状态和死亡率，研究结果表明，真鲷受精卵在盐度２７．８％以下的海水中呈沉性；在３１．２％以上的海水中则呈浮住；盐度２８．１５‰～３０．２‰．则为由沉性变为浮性的过渡阶段。真鲷受精卵在盐度１１．０８‰～４８．８５‰范围内均能孵化，但孵化的适盐范围为２７．１％～３８．０５‰，而孵化的最适盐度为２８．１５‰～３２．７０‰，从仔鱼的分布状态和仔鱼的成活率综合分析，真鲷仔鱼培育的最适盐度范围为２８．１５‰－３２．７０‰。     

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