饰纹姬蛙早期胚胎发育的研究

研究了饰纹姬蛙（Ｍｉｃｒｏｈｙｌａｏｒｎａｔａ）的早期胚胎发育．经雌雄成体腹腔注射ＬＲＨ－Ａ，促使其抱对、产卵．受精卵在水温２７±０．５℃的条件下进行培养．结果表明：在我国的蛙类中，饰纹姬蛙是早期胚胎发育最为迅速的种类之一；胚体纵轴伸长出现在原肠末期；在鳃循环期即可明显地观察到尾循环；出水孔的形成始于鳃盖完成时的腹中部，并逐渐移向腹后部．     

媒体纵览

正英成功培育出自然界"伪装大师"近日,英国牛津郡科茨沃尔德野生动物园成功培育出了8只稀有的越南棱皮树蛙,这也是该公园首次成功培育该品种蛙类。越南棱皮树蛙原产越南北部深山中,首次发现于1903年。它的皮肤棕绿相间,好似披着一层苔藓,堪称自然界"伪装大师"。这种蛙最长可达9厘米,通常雌性蛙体积比雄性蛙大。越南棱皮树蛙非常罕见,世界自然保护联盟曾将其列为"受威胁物种"。(来源:《英国每日邮报》2016年3月11日)     

南昌近郊黑斑蛙(Rana nigromaculata Hallowell)产卵习性的初步调查

1.以黑斑蛙(Rana nigromaculata Hallowell)为对象,从57年3月15日到5月10日在南昌近郊进行了产卵习性的初步调查。 2.调查是以九个不同环境条件的区域作为恒定工作对象来进行的。同时,还对调查期间内气温(干度)、湿度和水温进行了记载。(以上午6:30—8:30的为准)。 3.调查证明:黑斑蛙喜欢产卵于腐植质少Co_2含量较少的清洁坏境内,PH值为5.9—6.9之间,产卵地区与浅水沟的存在或农田的耕作也有密切的关系。 4.产卵温度幅度(以上午6:30—8:30为标准)为11.5—22℃,而以11.5—17℃为适宜温度。产卵湿度幅度为45—64％,而以45—54％左右最为适宜。产卵是在温度上升突然下降的刺激下进行的。由此推知:在南昌近郊,黑斑蛙产卵是在清明节前十天到清明节后十五天内进行的,而以清明节这几天产卵最多。 5.产卵是在水深浅于10公分以下的浅水稻田内进行的,这是因为:(1)浅水水温容易上升。(2)浅水能够溶解大量的氧,大量氧的存在才能适合胚胎发育时期的需要。 6.黑斑蛙产卵地区与蟾蜍产卵地区截然不同,这可能与成蛙的生活习性有关。 7.黑斑蛙是一次产卵的,产卵的数目为786—5,114个,这与王希成先生所报导的略有不同,这可能是因为地区不同的关系。     

中华蟾蜍指名亚种(Bufo gargarizan gargarizan)早期胚胎发育

2006年1—2月份对中华蟾蜍指名亚种的早期胚胎发育和产卵行为进行观察.结果表明,蟾蜍整个产卵时间为6.18±0.73 h(N=4),其中雌性产卵8.00±1.20次,雄性射精9.25±1.31次.产卵中,雌性产卵的时间间隔为0.75±0.06 h(N=39),抱对的蟾蜍要游到水面上呼吸,两次呼吸间隔为1.39±0.23 h(N=11).雌蟾蜍最后一次产卵到雌雄分开所需时间为0.96±0.19 h(N=7).从受精卵期至鳃盖完成期,胚胎发育可分为23个时期,在6℃～10℃的水温条件下,历时1111.23±21.64 h(N=7).     

饰纹姬蛙Microhyla ornata(Dumeril et Bibron)生殖频次初探

本文首次报告了饰纹姬蛙Microhyla ornata的生殖频次。在实验室人工鉰养条件下,从五月至九月上旬。5只供试的雌蛙中有两只产卵3次,一只产卵4次,一只产卵5次,一只产卵6次。事实表明饰纹姬蛙是一年多次产卵的蛙类。     

中国林蛙Rana temporaria chensinensis David胚胎发育时期

关于蛙的正常胚胎发育,国内、外先后曾由Pollister&Moore(1937)对树蛙Rana sylvatica Shumway(1940, 1942)对豹纹蛙Rana pipiens、朱治平和施履吉(1957)、和王应天(1958)对黑斑蛙Rana nigromaculata等进行了研究。本文所用材料系广布于内蒙古     

湿地生态恢复性林蛙养殖技术实践分析

实践过程中针对养殖方法、产卵期、孵化期、变态期以及黑龙江林蛙日活动规律进行了对比分析并得出结论,在每年4月28日至5月12日期间出现产卵高峰;在5-7℃、10-12℃、14-15℃池水温度范围有较高孵化率;采用混合饲料喂养的蝌蚪变态率均在68%以上;黑龙江林蛙每天9-11时和15-17时活动频繁,是最佳喂食时间。激发林蛙适应生态环境的潜在习性;四龄成蛙放归自然,改善并维持湿地生态环境的平衡关系。     

通辽地区鲢鱼、鳙鱼、草鱼提早产卵繁殖的技术措施

利用电厂余热控制水温,提早亲鱼培育时间,可将链鱼、鳙鱼、草鱼产卵时间提前40～50d,从而延长生长期,培育出大规格鱼种.     

安徽省泛树蛙属物种分类归属初探

泛树蛙属(Polypedates)的物种广泛分布于安徽省皖南山区和皖西大别山地区,此前安徽省所分布的泛树蛙类一直被记为斑腿泛树蛙P.megacephalus.鉴于近期安徽省内泛树蛙属物种的归属有存疑,笔者在大别山区和皖南山区广泛采集泛树蛙类的标本,并利用分子系统发育分析的手段,确定上述标本均为布氏泛树蛙Polypedates braueri.研究表明安徽省可能仅分布一种泛树蛙属物种——布氏泛树蛙,此前安徽省所记录的斑腿泛树蛙可能是对布氏泛树蛙的误判.     

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.     

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     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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