早晚弱光下不同基因型小麦光合碳同化酶活性差异的研究

研究了三个基因型小麦早晚弱光下旗叶的光合速率及其碳同化酶活性．结果表明：早晚弱光下光合速率存在基因型差异．对造成这种差异的原因进行分析表明，早晚弱光下光合速率差异（尤其是早弱光下）主要与RuBP羧化酶的活性有关，与PEP羧化酶的相关不显著，与PEP羧化酶与RuBP羧化酶的比值无关．     

锰离子对微球藻(Nannochloris)和杜氏藻(Dunaliella)光下气体交换的影响

锰离子在光合作用中可以促进氧的释放,由于其高氧还电位,在光系统Ⅱ的氧化侧充当电子传递体。曾有人报告光合细胞在某些情况下,在光下存在某些和光呼吸不同的吸氧反应,这种光推动下的氧的吸收可能是一种光还原作用。特别是当存在某种抑制光合碳循环的因子和缺乏Calvin循环的某种基质时,这种吸氧作用表现得更为明显,部分平衡了光合中氧的释放,使光合作用中氧的净交换量在某一段时间内可能趋于零。曾有人报告氯化锰(6×10~(-6)M)可促进甜菜分离叶绿体的光下氧还原作用。此外,Mn~(++)在光下和有充足的O_2的条件下,可以促进C_3植物光呼吸中乙醛酸的酶促或非酶促氧化,产生二氧化碳。然而在藻类中光呼吸是否存在,研究的结果甚不一     

SOD与酪氨酸酶共存时各自的活性

本文采用NBT(氮兰四唑)光还原法,测定了在酪氨酸酶存在下SOD酶的活性,并采用生成DOPA红的方法测定了SOD酶存在下酪氨酸酶的活性.并做了一系列干扰实验,实验结果指出:在酪氨酸酶存在下SOD催化O_2~??+O_2~??+2H~+??H_2O_2+O_2的反应活性降低,而在SOD存在下酪氨酸酶催化DOPA生成DOPA红的反应有明显抑制作用.     

一定强度的UVC辐射对玉米幼苗活性氧成分及抗氧化系统的影响

通过一定强度UVC照射,对玉米幼苗叶片内几种活性氧成分及几种抗氧化酶的活性变化进行检测,以探究玉米幼苗对UVC照射进行应答的可能机理。实验步骤:玉米幼苗经一定强度的UVC照射5h/d,连续照射5d后,测定超氧阴离子(O_2~-)产生速率及H_2O_2含量,并测定超氧化物歧化酶(SOD)、过氧化氢酶(CAT)及过氧化物酶(POD)的酶活力。结果显示:UVC单独照射时,玉米幼苗叶片内O_2~-产生速率极显著升高(P0.01),SOD活性、H_2O_2含量及POD活性表现均为极显著降低(P0.01),CAT活性无明显改变;日光—UVC混合方式照射时,O_2~-产生速率继续升高,SOD活性进一步下降,H_2O_2含量和POD活性则表现为增升(P0.01),CAT活性极显著降低(P0.01)。结论:UVC照射对玉米幼苗的损伤主要来自O_2~-,混合光照可加剧这种损伤;混合光照可使H_2O_2含量升高,主要由CAT进行清除;混合光照不是降低UVC对玉米幼苗负面效应的有效措施。     

超氧自由基对人红细胞膜脂流动性的影响

超氧自由基(O_2~-)是生物体内主要的自由基,在很多情况下,对机体产生损伤作用.近年来关于O_2~-与炎症、衰老,致癌及致突变的关系已有不少报道,在生物学和医学研究领域中受到广泛的重视.进一步研究O_2~-对细胞的作用,并采取措施保护细胞不受O_2~-的损伤,在理论上和实践上都有重要的意义.目前认为,O_2~-对细胞的损伤作用主要是由O_2~-引发的一系列自由基反应造成膜脂质过氧化导致膜结构及功能的改变.由于细胞过氧化反应在体内的进程很难掌握,故本文在离体条件下,研究O_2~-对红细胞膜脂流动性的影响,以进一步阐明O_2~-对细胞膜结构的关系.     

瑞香素及其铜(Ⅱ)、锌(Ⅱ)配合物对超氧自由基的清除作用

本文以健康人血红细胞及细胞膜为实验材料,利用核黄素-蛋氨酸光照体系产生O_D~-,考察了瑞香素及其铜(Ⅱ)、锌(Ⅱ)配合物时O_2~-的清除作用。结果表明:瑞香素及其铜(Ⅱ)、锌(Ⅱ)配合物对O_2~-都有明显清除作用,以钢(Ⅱ)配合物活性最高;O_2~-可使Hb氧化,使膜中过氧化脂质含量增加,SOD、瑞香素及其铜(Ⅱ)、锌(Ⅱ)配合物对此均有一定的抑制作用,其中以SOD活性最高。     

花生网斑病菌对白沙1016植株活性氧代谢和防御酶活性的影响

通过对受网斑病菌侵染的花生植株内主要防御酶活性和细胞损伤因子含量测定,探讨白沙1016抗网斑病的生理生化机制,为白沙1016品种改良及抗性品种培育提供理论依据。实验对白沙1016进行了花生网斑病抗性鉴定,并测定了感染网斑病菌的白沙1016植株在0～144 h期间O_2~-、MDA含量及4种防御酶活性的变化。结果显示:白沙1016对于花生网斑病属于感病品种,在接种网斑病菌144 h内,O_2~-和MDA含量均呈先上升后下降趋势,4种防御酶活性变化显著,POD活性变化程度最大,其次为CAT、PAL和SOD。得出结论:白沙1016的活氧代谢系统对网斑病菌的侵染有明显反应,清除病菌侵染而产生的活性氧是植株内进行最为强烈的生理生化反应,其次是对受病菌侵染的组织进行修复和防止病菌扩散的反应。     

H_2O_2诱导小麦叶片光合功能衰退的研究

采用不同浓度的H2O2处理小麦,研究H2O2对小麦叶片光合功能的影响.结果表明:1 mmol.L-1H2O2对小麦叶片光合作用基本无影响,10、100、200 mmol.L-1H2O2对小麦离体和连体叶片的光合作用均有不同程度的抑制作用,表现为光合速率、叶绿素含量下降.叶绿体超微结构显示10 mmol.L-1H2O2对其有影响,200 mmol.L-1H2O2处理后基粒明显破坏,类囊体膜无序.核酮糖-1,5-二磷酸羧化酶加氧酶(Rubisco)大小亚基和羧化活性在20 mmol.L-1H2O2逆境下变化小,100 mmol.L-1H2O2处理,Rubisco大小亚基降解明显,羧化活性微弱.说明H2O2诱导小麦叶片光合功能衰退.     

超氧自由基对人红细胞膜脂流动性的影响

超氧自由基(O_2~-)是生物体内主要的自由基,在很多情况下,对机体产生损伤作用。近年来关于O_2~-与炎症、衰老,致癌及致突变的关系已有不少报道,在生物学和医学研究领域中受到广泛的重视。进一步研究O_2~-对细胞的作用,并采取措施保护细胞不受O_2~-的损伤,在理论上和实践上都有重要的意义。目前认为,O_2~-对细胞的损伤作用主要是由O_2~-引发的一系列自由基反应造成膜脂质过氧化导致膜结构及     

5-azaC处理对低温弱光胁迫下黄瓜幼苗抗氧化酶活性的影响

为了研究5-azaC处理与植物耐冷性机理之间的关系,本实验以黄瓜幼苗为试材,研究了不同浓度5-azaC处理对低温弱光(10℃/6℃,300(μmol/m~2)/s)胁迫下黄瓜幼苗抗氧化酶活性的影响。结果表明:与对照相比,喷施500~800μmol/L的5-azaC处理可以显著降低幼苗叶片内MDA含量(P0.05),在低温24 h时分别降低了19.45%、19.83%,低温48 h时分别降低了12.19%、16.20%;提高SOD、CAT、APX和GR抗氧化酶活性,有效降低了黄瓜幼苗在低温弱光胁迫下活性氧(H_2O_2和O_2~-)的产生和积累;但随着浓度的升高,1000~5000μmol/L的5-azaC处理导致黄瓜叶片膜脂过氧化产生,使抗氧化酶活性显著降低,导致植物产生氧化损伤。     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-