粘球藻(Gloeocapsa sp.)细胞粗提物放氢特性研究

粘球藻培养物细胞破碎后,经一段时间的厌氧保温处理,可诱导出较高的氢酶放氢活性。在常温厌氧条件下放置数日后,这种酶粗制剂仍可利用连二亚硫酸钠/甲基紫精作为电子供体放氢。内源电子供体放氢活性的高低与细胞破碎前内部光合产物积累水平有关,前期的暗饥饿可明显降低这种放氢,细胞破碎前后外加糖源均可提高放氢。酶反应最适温度为55℃,最适pH在6.5左右,不依赖于光,受CO、O_2和C_2H_2的抑制。这种氢酶放氧活性的诱导出现受蛋白合成抑制剂的阻止。     

螺旋藻(Spirulina platensis)放氢的研究

螺旋藻含有可逆性氢酶,在合适的条件下能催化放氢．研究表明：当培养基的ｐＨ值为８．５～９．５,气相氧浓度为１％的条件时,能使螺旋藻放氢达到最大效率．外加葡萄糖、蔗糖有利于放氢,葡萄糖、蔗糖的最适浓度为０．１ｍｏｌ／Ｌ,而ａ－酮戊二酸、柠檬酸等对螺旋藻的放氢没有促进作用．     

螺旋藻放氢的研究

螺旋藻含有可逆性氢酶，在合适的条件下能催化放氢。研究表明：当培养基的ｐＨ值为８．５￣９．５，气相氧浓度为１％的条件时，能使螺旋藻放氢达到最大效率。外加葡萄糖、蔗糖有利于放氢，葡萄糖，蔗糖的最适浓度为０．１ｍｏｌ／Ｌ，而α－酮戊二酸，柠檬酸等对螺旋藻的放氢没有促进作用。     

4种钝顶螺旋藻生长与放氢的比较研究

针对4种钝顶螺旋藻品种的生长条件,以及放氢情况进行实验比较研究,其目的是要探索螺旋藻的放氢资源,进一步深入地研究和利用螺旋藻的氢能.结果表明,不同品种的钝顶螺旋藻有不同的最佳生长条件,而且在放氢的时间和量上也有很大的差异,由此可以推论品种的筛选和改良可以作为研究提高螺旋藻放氢量的途径之一.     

CO2对亚心形扁藻生长及光合放氢的影响

利用鼓泡式光生物反应器,比较通入空气及不同φ(CO2)(1%、3%、5%、10%、15%)对亚心形扁藻生长及光合放氢的影响.实验结果表明:CO2含量对扁藻生长及光合放氢均有影响,其中φ(CO2)为3%时培养及光合放氢的效果最好,培养的藻细胞10d细胞密度倍增3.8倍,比生长速率为0.134d-1;培养到第7d,细胞密度调整为6×106个/mL,暗诱导12h后,在15μmol/L解偶联剂羰基氰化物间氯苯腙(CCCP)作用下连续光照24h,培养的藻细胞产氢量提高70%,最大比产氢速率为3.24mmol/(g·h).代谢分析表明,φ(CO2)为3%时培养的藻细胞淀粉含量最高,是对照组的2.1倍,CO2作为惟一碳源时淀粉含量与产氢量密切相关.利用CO2培养提高扁藻细胞产氢量的工艺有利于温室效应气体的减排.     

胞外ATP影响ZnCl_2诱导烟草悬浮细胞活性和呼吸速率的降低

以烟草悬浮细胞BY-2为材料,探讨细胞外ATP对ZnCl_2诱导的细胞活性降低和呼吸抑制的调节作用.结果表明,随着ZnCl_2浓度逐渐增加,细胞活性、胞外ATP浓度和细胞呼吸速率均随之降低.在400 mmol/L ZnCl_2胁迫细胞的条件下,研究了细胞外ATP对ZnCl_2诱导的细胞活性降低和呼吸抑制的调节作用.结果发现,与400 mmol/L ZnCl_2胁迫下的细胞相比,加入20μmol/L外源ATP到ZnCl2胁迫下的细胞中,会使细胞的活性、胞外ATP浓度和细胞呼吸速率均有显著升高.胞外ATP浓度的变化可能是造成ZnCl_2胁迫下细胞活性受抑制的原因之一,同时胞外ATP对ZnCl_2胁迫下细胞的活性具有一定的调节作用.     

过氧化氢对不同光质下盐藻SZ-05生长及代谢产物积累的影响

研究不同浓度的过氧化氢对在不同光质(白、红、黄、蓝光)下生长的杜氏盐藻SZ-05(Dunaliella salina SZ-05)生长与代谢产物积累的影响.结果表明,当过氧化氢浓度从10-6 mol·L-1增至10-4 mol·L-1时,对盐藻的生长有微弱的促进作用,各种光质培养条件下盐藻的细胞密度均逐渐增大至最大值,其中红光下的盐藻细胞密度最大,为6.19×106 ml-1;当过氧化氢的浓度增加到10-3 mol·L-1时,细胞密度减小,表现为抑制作用.在过氧化氢浓度为10-6 mol·L-1时,不同光质培养条件下盐藻的单个细胞内β胡萝卜素的含量均达到最大值,其中红光单个细胞内的β胡萝卜素的含量最大,为0.790 pg.当过氧化氢浓度继续增加时,单个细胞内β胡萝卜素的含量降低,表现为抑制作用.在过氧化氢浓度为10-3 mol·L-1时,红光条件下生长的盐藻胞外多糖含量获得最大值,为5.97 pg.     

光合细菌Chromatium vinosum可溶性氢酶的某些理化性质

光合细菌Chromatium vinosum含有一种可溶性氢酶和一种膜结合态氢酶。在培养基中加入终浓度为1μmol/L的Se,细胞中可溶性氢酶的含量增加1.7倍。C.vinosum可溶性氢酶可以利用甲基紫精、苄基紫精和细胞色素C为电子载体催化吸氢与放氢,但不能利用NAD,NADH,NADP和NADPH等进行催化放氢和吸氢。可溶性氢酶易被CO所抑制,在反应系统中加入终浓度为2.5μmol/L的CO时,可抑制氢酶最大放氢活性的一半。与C.vinosum膜结合态氢酶相比,可溶性氢酶较易被胰蛋白酶降解而使氢酶催化吸氢和放氢的活性降低。     

新型平板反应器内光暗周期的仿真优化

利用Fluent软件,对加入扰流柱的新型平板光生物反应器内的微藻细胞运动轨迹进行仿真,基于Cornet模型计算微藻细胞经历的光暗周期. 根据藻液浓度变化,优化入射光强,以保证在不同藻液浓度下藻细胞平均光暗周期始终保持最小,约4.25s. 根据仿真结果,对不同藻液浓度下达到最优平均光暗周期所需的入射光强进行拟合,相关系数（R²）达到0.9994,为平板反应器的进一步优化设计提供了新的思路.     

培养条件对蓝细菌生长及PHB积累的影响

对蓝细菌集胞藻 (Synechocystis) sp. PCC6 80 3的细胞生长及胞内聚 -β-羟基丁酸酯 (PHB)的积累进行了研究 ,以探索提高蓝细菌 PHB积累水平的可能性。野生型集胞藻于 BG- 11培养基中通气培养 ,改变氮源浓度、碳源种类、光照强度 ,测定细胞的生长及胞内 PHB的浓度。结果表明 :只有在氮饥饿培养时 ,胞内 PHB水平才会有明显提高。氮饥饿条件下 ,混养生长时收获的细胞量最多 ,弱光自养时细胞几乎不生长 ,两种条件下 PHB的积累水平相近 ,低于细胞干重的 0 .5 %。异养时细胞生长与混养时相近 ,PHB可积累至细胞干重的 1.0 %。强光自养最有利于 PHB的积累 ,生长 7d后可积累至细胞干重的 4.1%。该研究的结果可为进一步提高蓝细菌中 PHB的积累水平提供参考     

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.     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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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