高盒形藻的有性生殖发生

从厦门沿岸分离高盒形藻，培养观察其有性生殖发生．该藻在光诱导下每天发生一次性分化，每次持续４ｈ．从海区采样观察和实验室培养，性分化在６２μｍ以下宽度的细胞中发生．每个精原孢囊产生１２８个单鞭毛精子，精子生活１９ｈ之后存活率大大下降，每个卵囊形成成对的卵子，精子和卵子几乎同步发生．结果表明，该藻可能存在小型和中型细胞分段发生性化和两次细胞复大现象．生殖中呈现的相似和相异特征，显示种间的亲缘关系．     

中华半管藻繁殖生物学研究：Ⅳ.有性生殖与生殖调控

中华半管藻有性生殖是一个卵配过程，在培养种群细胞宽４￣５０μｍ时，性细胞在４￣３０μｍ宽的细胞中产生。精子发生过程较为罕见，精原孢囊形成合胞体，每个孢囊产生３２或６４个精子，复大后藻细胞最大宽度可增至１２．５倍。整个生殖过程需经历一周左右，在弱光．短日照与正常盐度获得最高性分化率。     

中华盒形藻有性生殖的研究

中华盒形藻有性生殖中,雌雄性的分化分别在39—78μm宽度的细胞中产生.雌雄配子形成在早晨5-6时开始,14-20时进行减数分裂,22时形成精子,卵子同时成熟.受精多数在午夜之前进行.合子经过复大孢子萌发阶段发育成为新子代复大细胞,细胞宽度增大3.8—5.5倍.在温度20—24℃和光强度4500—5000lx条件下,雄配子发生全程一般需要15h,而合子萌发成为新子代复大细胞通常要经历12h以上时间.     

微生物絮凝剂对小球藻细胞氧化应激研究

小球藻作为能源藻,可以提供产生物柴油,但是小球藻生物质的获取成为能源藻发展的瓶颈.目前研究藻细胞生物质收集的方法很多,但不同收集方法对能源藻细胞的氧化应激研究却很少.分别研究絮凝功能细菌xn-1所产生物絮凝物质和离心法对能源藻——小球藻生物质在收集过程中对藻细胞的氧化应激,以期确定絮凝微生物对小球藻细胞的生物安全性.采用涂布划线法从藻际分离纯化絮凝功能微生物;通过梯度醇沉法获得絮凝物质;分别用絮凝微生物所分泌絮凝物质和离心法收集藻细胞生物质,并对藻细胞内蛋白含量、总糖含量、丙二醛含量(MDA)、过氧化氢酶(CAT)活性、谷胱甘肽(GSH)含量和抗坏血酸(AsA)含量进行测定;以分光光度计测定其吸光度值.经过测定并经过统计学显著性分析,发现离心作用下收集的藻细胞内的MDA,GSH和AsA含量显著高于利用絮凝物质絮凝得到的藻细胞.离心作用相对于絮凝作用造成藻细胞膜发生更高的脂质过氧化,产生大量的活性氧自由基,诱导非酶抗氧化系统响应.因此,离心法收集藻生物质相对于微生物絮凝对藻细胞的伤害更大,絮凝微生物比离心法更适合于收集能源藻生物质.     

鼠尾藻群体的有性生殖力影响因素研究

【目的】研究鼠尾藻(Sargassum thun bergii)有性生殖相关因子间的关系,分析鼠尾藻群体的有性生殖能力。【方法】通过统计分析方法,研究藻体长度与侧枝数、侧枝长度与生殖托数、生殖托长度与生殖托挂卵数间的关系。【结果】藻体长度与侧枝数、侧枝长度与生殖托数、生殖托长度与生殖托挂卵数间都为线性正相关,利用回归方程推算,1株成熟的鼠尾藻藻体能产生2×105~3.3×106个受精卵。【结论】1株成熟鼠尾藻的产卵量基本可满足1m2的采苗生产需要。     

模拟胞外聚合物对单细胞藻类聚集行为的影响

文章以海藻酸钠和牛血清白蛋白分别模拟胞外聚合物(extracellular polymeric substances,EPS)的主要成分多糖和蛋白质,从小球衣藻细胞的运动性和表面特性、多糖、蛋白质溶液的黏度等方面探究EPS对小球衣藻聚集行为的影响。结果表明,EPS通过降低藻细胞的表面电荷,使得细胞间排斥能峰降低,导致藻细胞运动性改变,细胞产生无序运动并发生剧烈碰撞,同时受到EPS的黏滞力的影响,最终产生聚集的现象。该研究证明了EPS可以显著地促进藻类聚集体的形成。     

梯度升温降温条件下球形棕囊藻生长和生理生化响应

球形棕囊藻(Phaeocystis globosa)藻华频繁暴发,不仅会危害海洋生态系统和渔业生产安全,还会堵塞核电站冷源取水系统产生严重安全隐患。球形棕囊藻藻华的暴发有明显的季节性特征,本研究采用梯度升温降温实验,研究不同温度(高温、低温)条件下球形棕囊藻的生理生化响应及温度胁迫诱导的细胞程序性死亡(Programmed Cell Death,PCD)过程。结果显示：低温胁迫抑制球形棕囊藻细胞的正常生长繁殖,但不会激活其进入PCD响应;高温胁迫使球形棕囊藻出现氧化应激,从而导致其发生PCD响应,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性显著提高,半胱氨酸天冬氨酸蛋白酶-3(Caspase-3)被激活后球形棕囊藻细胞出现Annexin V-FITC阳性反应。环境胁迫使球形棕囊藻细胞产生氧化应激,抗氧化酶活性快速升高,并激活Caspase-3使藻细胞发生PCD响应,表现出细胞磷脂酰丝氨酸(PS)外翻、细胞收缩和质膜从细胞壁分离等特征。本研究可为深入探讨球形棕囊藻藻华的生消机制与防治赤潮灾害提供一定的理论基础。     

底栖硅藻新月筒柱藻对锌胁迫的生理学效应

采用流式细胞仪检测细胞增长与色素含量、原子火焰吸收光谱法测定金属含量以及显微镜观察细胞状态等方法研究了红树林底栖硅藻新月筒柱藻(Cylindrotheca closterium (Ehr.) Reimann and Lewin)暴露在重金属锌96 h内的细胞增长、光合色素含量和细胞形态结构等胁迫效应,以及锌在藻细胞内外动态分布的情况.结果为:(1)在Zn2 浓度小于10 mg/L范围内,锌对新月筒柱藻的细胞增长和色素含量均无显著抑制作用.(2)1 mg/L和10 mg/L的Zn2 对藻细胞内的叶黄素和叶绿素a的产生都有促进作用.(3)在实验开始的24 h内,藻细胞处在低Zn2 浓度(1 mg/L)时,藻细胞胞内吸收的Zn2 大于胞外吸附的Zn2 .而藻细胞处在高Zn2 浓度(10 mg/L)时,胞外吸附的Zn2 较胞内吸收的大,细胞内Zn2 的含量处在较低水平,从而促进细胞的增长和色素的合成并使细胞免受外界高浓度锌的毒害.可见,新月筒柱藻正是通过改变对锌的富集方式,以保持细胞内锌含量的相对稳定来适应不同浓度锌的胁迫.     

丙溴磷对二种海洋微藻的GPx活性及GSH、CAR含量的影响

实验以三角褐指藻和青岛大扁藻为材料,进行了丙溴磷农药对海洋微藻的抗氧化防御系统成份－GPx(glutatione Peroxidase)活性和GSH（glutathione),CAR(carotionid)含量的影响研究,结果表明,在丙溴磷胁迫下,微藻的GPx活性呈现下降趋势,GSH和CAR含量也一明为下降趋势,并且胁迫的时间越长,胁迫的强度越大它们下降的幅度也越大,因此微藻细胞对抗氧化防御系统的能力被消弱,从而可能导致活性氧在体内的过量产生与积累,进而对藻细胞造成更大的伤害。     

苔状鸭毛藻（Symphyocladia marchantioides）切段再生的研究

本文报导苔状鸭毛藻(symphyocladia marchantioides)的切段再生，分别对藻体的顶端、中部、基部进行了切段的培养，研究了切段的离体培养、细胞分裂、再生以及形态发生等等。从多次试验中发现：切段后，藻体的不同细胞，再生形式不同，脉细胞长出无色的假根丝，而一般的营养细胞长出小芽。初生的小芽由小的园形细胞组成，随着小芽的不断长大，才逐渐形成和大藻体一样的构造。切段后藻体细胞分裂极为旺盛，再生的新藻体多。     

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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