七彩神仙鱼胚胎及仔鱼发育研究

对七彩神仙鱼(Symphysodon aequifasciata)胚胎及仔鱼发育进行了研究,详细描述了发育各期的形态特征和所需时间.结果显示,七彩神仙鱼受精卵为红褐色粘性卵,在(29.0±0.5)℃时,孵化所需时间为52.5h.初孵仔鱼体长(3.52±0.19)mm,体高(1.27±0.07)mm,身体透明,头部粘附在产卵基上,尾部随着水流颤动.仔鱼出膜5d后亲鱼开始"奶子",到第13d基本发育完善.     

澳洲宝石斑鱼的胚胎发育

采用体视解剖镜、显微镜对澳洲宝石斑鱼的胚胎发育进行观察,描述了各个发育时期的主要形态特征.结果显示:(1)宝石斑鱼的卵和受精卵较小,受精卵径平均1.5mm;(2)受精卵吸水后呈圆形,为浮性卵;(3)胚胎卵黄囊表面有一个大的圆形脂肪球;(4)在水温23-29℃条件下,受精卵历时24 h脱膜孵出仔鱼,再经3.5 d开口摄食,转入混合营养时期;(5)胚胎发育主要经历卵裂期、囊胚至原肠期、神经胚期、器官形成期和孵出期5个主要时期.     

半滑舌鳎的育苗效果及生物学特征的观察

在水温为21.0～23.7 ℃,盐度为33.5的条件下,用约7.8×105粒受精卵孵出仔鱼约55万尾,孵化率达70 %左右,再经过79 d的培育,培育出幼鱼2.287×105尾,成活率达到41.5 %.初孵仔鱼平均全长(3.16±0.22)mm;初孵仔鱼至孵化后3日龄为前期仔鱼,冠状幼鳍形成,大部分仔鱼已开口,逐渐建立...     

鲶胚胎和幼鱼发育的研究

鲶受精卵呈圆球形、绿色，吸水膨大后直径４．０５～５．５７ｍｍ．用胰蛋白酶液处理受精卵后观察受精卵和幼鱼阶段的发育．温度在２７．５～３１℃时，幼鱼孵出需要２９．５ｂ，初孵仔鱼体全长约４．６４～５．３２ｍｍ．幼鱼生长速度较快，孵出９ｄ后，体全长可达３２～３６ｍｍ．还讨论了鲶胚胎和幼鱼的形态结构以及胚胎细胞分化等特点．     

鲈鲤胚胎发育特征观察

观察了水温（18±0．5）℃条件下,鲈鲤[Percocypris pingi pingi（ T chang ）]的胚胎发育特征。结果显示：成熟鲈鲤卵呈球形、桔黄色,为粘性卵,卵径2．2mm,卵膜遇水膨胀后,最大外膜径达3．2-3．8mm。受精卵在水温（18±0．5）℃条件下,受精2h28min后开始第1次卵裂,受精后45h23min开始形成器官,受精后126h28min孵出仔鱼。初孵仔鱼全长为10．4mm,卵黄囊大而侧扁。根据胚胎发育过程的形态特征,可将鲈鲤胚胎发育过程分为受精卵、卵裂、囊胚、原肠胚、神经胚、器官发生和出膜7个连续阶段。32个时期。     

涪江下游唇胚胎发育研究

涪江下游唇鱼骨每年3～4月,在水温12～24℃范围内均可产卵繁殖.成熟卵圆形,橘黄色或橙黄色,卵径160～190mm,平均175mm,遇水能普遍激动,但始终不分裂.受精卵具粘性,卵膜吸水膨胀后达240～270mm,并在卵膜外形成一层胶膜.受精卵在125～185℃下历时约195h孵化,胚胎的孵化与孵化腺细胞的出现密切相关.低温下可出现“宕延孵出”的现象,发育的下限温度为102℃.初孵仔鱼全长650～680mm,平均662mm,眼色素和胸鳍原基已出现.     

双棘黄姑鱼的早期发育研究

对双棘黄姑鱼(Nibea diacan thus(Lacépède))的胚胎和仔、稚、幼鱼各发育阶段的形态特征进行了描述.双棘黄姑鱼的受精卵为圆球形浮性卵,无色透明.在水温25.9~27.0℃、盐度26.6的条件下,经19.2 h陆续孵出仔鱼.胚胎发育可分为24期.培育水温25.4~29.4℃、盐度26.6~30.6时,初孵仔鱼至孵化后3日龄为仔鱼前期,2日龄仔鱼开口;孵化后4~16日龄为仔鱼后期;孵化后17~24日龄为稚鱼期;孵化后25日龄进入早期幼鱼期.     

舟山近海鮸鱼胚胎和早期仔鱼的发生及与盐度的关系

2005年10月,在浙江华兴海水种苗有限公司舟山大沙基地,对舟山近海鮸鱼胚胎和早期仔鱼的发生及盐度对其发育的影响进行了连续观察,并较为详细地描述了舟山近海鮸鱼胚胎和早期仔鱼发育各期的形态特征。结果表明:受精卵为圆球形,透明,油球1个位于卵中央,卵径1 000μm左右,油球直径330μm左右。在水温22～23℃、盐度26.6时,孵化时间约22.5 h;初孵仔鱼,肌节约32对,全长2 075μm,心跳116次/min;孵出后第3天开始开口,第5天卵黄囊完全消失,第7天油球完全消失。在盐度10.0～50.0范围内,鮸鱼胚胎发育的快慢无显著差异,均在22.5～23 h之间。胚胎在此盐度范围内都能孵出仔鱼,但盐度对孵化后仔鱼成活及畸形率影响较大,孵化率与盐度变化呈正抛物线形分布,畸形率呈反抛物线形分布。     

团头鲂的胚胎发育与观察方法优化

通过人工繁殖获得团头鲂受精卵,在体视显微镜下对其胚胎和早期仔鱼发育过程进行了连续观察、拍照与测量.结果显示,团头鲂受精卵呈圆球形,具黏性,卵径(1.18±0.09)mm;在水温(21±1)℃条件下,团头鲂胚胎发育从受精到孵化历时39h10min,经历了胚盘形成、卵裂期、囊胚期、原肠胚期、神经胚期、器官形成期和出膜期7个发育阶段;初孵仔鱼体长(3.44±0.29)mm,出膜后第4d仔鱼鳔完全充气,卵黄囊消失;观察时,受精卵至尾鳍出现期胚胎置0.7%生理盐水中,肌肉效应期和后面各时期的胚胎经4%多聚甲醛固定后置3%甲基纤维素中拍照可获得良好效果.该工作为研究团头鲂胚胎早期发育过程提供了实时和动态的图像资料,并为鱼类胚胎发育观察提供了基本技术参考.     

翘嘴红鮊胚胎发育研究

采用连续观察法研究翘嘴红鲌(Culter alburnus Basilewsky)人工授精的去膜受精卵的发育.结果显示,翘嘴红鲌胚胎发育可分为受精卵、胚盘形成、卵裂期、囊胚期、原肠期、神经胚期、胚孔封闭期、眼基和眼囊出现期、尾芽至肌肉效应期、心脏原基期至心脏博动期、出膜前期共11个时期.受精卵呈灰黄或青灰色,直径0.8mm左右,吸水后直径可达1.2mm左右,在水温27℃条件下,受精卵历时1560min孵化,积温702℃·h;初孵仔鱼全长2.3mm左右.     

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.     

Design and analysis of generic LBS application developing platform

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.     

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