中华绒螯蟹育苗传统亲本选择投放关键参数的科学性

为探讨中华绒螯蟹育苗传统亲本选择投放关键参数(亲本"公3母2",选择投放雌雄性比2～3:1)的科学性,通过设置不同性比的交配实验,对中华绒螯蟹交配前后的生殖状况进行了比较研究。结果显示:在该体系下(本文代表雌雄性比为3:1组),交配后与性比1:1组一样,纳精囊内始终存乳白色精液精荚等雄性产物,抱卵个体并没有出现诸如性比5:1组中纳精囊中因缺乏精液精荚而流产现象。随着性比的提高,各组无论雄性输送还是雌性纳精囊中储存雄性产物的量均出现了较大幅度的震荡,但整体呈下降趋势。前期观察发现:这些差异可能主要与中华绒螯蟹随机交配及雌蟹未产卵之前可以多次与同一或不同雄蟹交配的生殖策略有关。因此,该参数充分兼顾了中华绒螯蟹生殖的生物学特性,保障了雌蟹交配个体均能成功抱卵,具有相当的精准性,同时这也解释了多年以来中华绒螯蟹育苗单位始终采用该参数而没有出现精子限制现象的原因。     

中国长翅目四新种记述(长翅目:新蝎蛉属,蚊蛉属)

记述中国长翅目新蝎蛉属3新种,蚊蛉属1新种.模式标本保存在浙江自然博物馆昆虫标本室.赵氏新蝎蛉Neopanorpa chaoi sp.nov图1-7.正模♂,贵州梵净山,2001-Ⅶ-26.配摸♀,副模7♂,19♀采地,采期同正模.淡瓣新蝎蛉Neopanorpa pallivalva sp.nov图1-6.正模♂,贵州梵净山,2001-Ⅶ-27.配摸♀,副模4♂,16♀采地与采期同正模.锚形新蝎蛉Neopanorpa anchoroides sp.nov图1-8.正模♂,贵州梵净山,2001-Ⅶ-30.配摸♀,副模4♂,13♀采地与采期同正模.李氏蚊蛉正模♂,Bittacus lii图1-3.贵州梵净山,2001-Ⅶ-28.配摸♀,副模4♂,采期与采地同正模.     

松材线虫与拟松材线虫种间杂交特性研究

选取来自中国、日本和美国的松材线虫(Bursaphelenchus xylophilus)4个虫株,以及中国的拟松材线虫(B.mucronatus)2个虫株进行生物学杂交和交配对象选择试验。结果表明:松材线虫和拟松材线虫的部分虫株可以发生种间杂交,正交总交配成功率为4.2%,反交总交配成功率为10%,反交成功率是正交的2倍。杂交整体发生率极低,杂交后代较难形成可持续的繁殖种群。采用松材线虫(简称Bx)/拟松材线虫(简称Bm)快速分子检测系统对杂交F1代幼虫进行分子鉴定,结果表明F1代幼虫既含有Bx分子标记也含有Bm分子标记。继代培养30 d后,杂交后代在基因型上表现出了不同趋向的分化,其中BxAN5♀×Bm JNL1 ♂、BxAN5 ♂×BmAN5♀和BxUSA ♂×Bm JNL1♀的杂交后代趋向于成为松材线虫占主导的种群,BxJNL5 ♂×BmJNL1♀的杂交后代趋向于成为拟松材线虫占主导的种群。在有种内交配资源存在情况下,无论松材线虫还是拟松材线虫均倾向于优先选择种内交配资源。研究表明松材线虫和拟松材线虫之间存在一定的生殖隔离,自然状态下种间交配可能会产生,但杂交后代较难形成可持续性繁殖的生殖后代。     

野外猪獾(Arctonyx collaris)交配行为观察

2017年3月13日-5月13日,获得猪獾在野外交配的红外相机视频463个片段,总有效时长8 057 s。交配前雄兽对雌兽有明显看护行为,时间长达30. 55 h。4月18日01:55-08:49,雌兽在洞巢外接受了雄兽1次爬跨、3次交配,每次交配持续时间分别为:731 s、1 690 s、1 494 s,交配维持时间明显大于多数已知哺乳动物的交配时间。观察初步结果显示:1)猪獾的交配时机由雌兽掌握,雌兽对雄兽有明确的邀配(sexual solici-tations)行为; 2)在一个发情周期内,雌兽可接受同一雄性个体的多次交配; 3)雄兽交配过程中有快速、持久抽插的动作。这些交配策略,支持生殖刺激(Stimulation of reproduction)假说和护卫交配权(Mate guarding)假说。     

裸小鼠在普通环境中使用IVC笼具生产繁殖的初探

目的探讨BALB/C-nu裸小鼠在普通环境中使用IVC笼具生产繁殖的效果。方法引进3对BALB/C-nu种鼠按1♂nu/+×1♀nu/+交配,再从仔代中建立血缘扩大群,按1♂nu/nu×3♀nu/+;1♂nu/nu×1♀nu/nu两种繁殖方法进行生产繁殖。结果种鼠生产10胎平均产仔8.6±1.02(裸鼠1.8±0.63)只;血缘扩大群1♂nu/nu×3♀nu/+生产42胎,平均产仔6.92±1.47(裸鼠3.52±1.29)只;1♂nu/nu×1♀nu/nu生产12胎,平均产仔4.25±1.36全裸鼠。经检测符合SPF级。结论在普通环境中应用IVC笼具,只要注意室内卫生消毒,在净化工作台上无菌操作能够繁殖合格的裸小鼠。     

不同性比交配对玉米螟雌蛾生殖力的影响

在实验室内,用人工饲养的玉米螟成虫进行了不同性比的交配试验。观察到雌蛾在生殖力方面表现出一定的差异。选择每雌产卵量做为衡量雌蛾生殖力的主要生理指标,对所产卵的孵化率也进行了观察。基本结果是:玉米螟雌蛾的生殖力随交配成虫性比的增加而有所提高,表现为每雌产卵量增加。性比的改变对产卵孵化率的影响不明显。     

科学问答

●将人的精子输到母羊体内，会不会生出一个半人半羊的怪物来？ 在生物进化的漫长过程中，通过自然选择，产生了一个物种繁殖的自我保护机制，叫做“生殖隔离机制”，这种隔离机制主要是为了保持物种的相对稳定性。其大致的含义是说，相差较大的不同物种，如果进行生殖交配，是不可能产生有活力的后代的。只有在相同或极为相近的物种之间进行生殖交配才能产生有活力的后代，比如说狮子和老虎、马和驴交配就可以产生有活力的后代。     

基于SSR分子标记检测褐飞虱交配次数及性选择

为探明褐飞虱交配次数和性选择的生殖行为特征,构建了褐飞虱生物型1和生物型Y的近交系,筛选了在不同近交系之间存在明显差异的9个SSR(Simple Sequence Repeats)分子标记用于亲子鉴定.在雌虫交配次数试验中,观察并分子鉴定到23头成功交配的雌虫,其中19头雌虫一生仅进行1次交配,4头雌虫一生进行了2次交...     

花鼠种群生态学研究(Ⅱ)——繁殖特征

报道了山西省隰县地区花鼠（Ｅｕｔａｍｉａｓｓｉｂｉｒｉｃｕｓ）种群的繁殖特征．对繁殖期、年繁殖次数、性成熟速率，不同年龄组的性比、怀孕率、胎仔数和繁殖指数等做了分析研究．花鼠种群的总性比（♀／♂）为１．０７，雌性略多于雄性，但是也随季节和年龄的不同而变化．刚出生的仔鼠性比为１．００，而幼年组则升为１．４１，到成年组Ⅰ、Ⅱ组则降为０．９２和０．８８，老年组则为１．３３，说明雌性仔鼠的成活率较高，怀胎、产仔等行为会增加成年雌鼠的死亡率，但雌鼠比雄鼠寿命长．花鼠年繁殖一次，交配、妊娠时间在３月－６月上旬．当年鼠越冬后（从出生开始计算月龄１０个月左右）参与繁殖．成年Ⅱ组繁殖力最强，繁殖指数（５．５０）高于成年Ⅰ组（４．１７）和老年组（４．１６）．花鼠胎仔数３～７只，平均为５．０４±０．１３只．     

瓦氏黄颡鱼的繁殖群体结构与生长特性

瓦氏黄颡鱼繁殖群体的雌雄性比为1:1.17,雄性群体2-3龄鱼占81.4%,雌性群体2-3龄鱼占92.5%。体长13-15㎝㎝体㎝㎝繁殖群体的㎝㎝㎝㎝,雌雄繁殖群体体㎝㎝㎝㎝㎝㎝㎝集中在30-50g和40-70g之间。不同年龄、不同性㎝、不同性腺发育阶段之间,其肥满度和脂肪系数均存在不同程度的生长差异,通常以2龄鱼和性腺发育到Ⅱ、Ⅲ期㎝体较高,发育到同期的雄性群体脂肪系数通常高于雌性群体,而肥满度略低于雌性群体。     

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

正~~