稀土元素Ce对水体富营养化的影响

在静态供试水体中分别添加不同浓度的Ce(IV),利用定期测定水体中N、P、DO、COD含量及藻类叶绿素水平的方法,研究Ce对富营养化水体中浮萍藻类增长的影响.结果表明,在本实验条件下,添加较低浓度Ce(0.15,0.25,0.50 mg/L)能促进红浮萍生长和实验水体的富营养化,但随着浓度的进一步升高(1.0 mg/L),则对红浮萍生长和实验水体的富营养化有抑制作用.     

水体富营养化与防治

本文对水体富营养化问题进行了综述、指出富营养化是危害水质的重要因素,而藻类在富营养化的水中会迅速繁殖和生长,导致水华和赤潮的爆发,对水体富营养化问题及对有害藻类的控制已受到国内外有关专家的关注。     

长江和嘉陵江交汇段营养限制因子的试验

重庆三峡库区富营养化发生务件与机理研究中,针对营养限制因子与富营养化的重要性和复杂性,通过藻类潜力试验（ACP试验）确定长江和嘉陵江交汇段水体营养限制因子．研究认为：单独的氮对藻类增长无明显促进作用,磷则构成水体藻类增长的限制性因子;TN／TP值高藻类现存量就小,TN／TP值低藻类现存量就大;原水中磷含量越高,添加磷对藻类增长的促进作用越大．这为重庆两江交汇段水体富营养化发生条件及机理分析提供了重要参数．     

水中叶绿素浓度偏振反射光谱特性研究

自然界的水体尤其是内陆水体常常会受到大面积污染并且富营养化,而水中藻类物质的大量繁殖是造成水体富营养化的一个重要指标。在藻类中叶绿素的含量是比较稳定的,并且测量方便,因此在水体富营养化程度监测中,将叶绿素浓度作为其重要参数来研究是科学可行的。本文通过完整测量和分析不同叶绿素浓度水体在2π空间上的偏振反射光谱数据,总结出其中的变化规律,为以后利用偏振光谱监测水体富营养化状态提供科学依据。     

莫愁湖富营养化限制性因素确定的AGP实验研究

莫愁湖作为南京市一个重要的景观类湖泊,近些年已经呈现较为严重的富营养化状态.探求影响莫愁湖水质富营养化的限制因子,对于防治莫愁湖水体富营养化,维护莫愁湖水质特别重要.本文通过莫愁湖藻类增长潜力试验研究,设立试验对照组,确定莫愁湖富营养化的主要限制因子为氮,并为防治莫愁湖水体富营养化,加强水质管理,进行水体修复提供科学依据.     

大庆湖泡浮游藻类资源调查及营养状况研究

对大庆市大龙虎泡、红旗水库、黑鱼泡、东湖水库不同水体进行了浮游藻类的采集及分类鉴定;利用浮游藻类的生物量、优势种以及藻类群落组成等指标评价了水质。结果表明:四水体有浮游藻类6门,即硅藻门、绿藻门、蓝藻门、裸藻门、黄藻门、甲藻门;四水体的优势种均为硅藻门、绿藻门、蓝藻门,水体均出现富营养化。根据研究结果,应对四水体采取相应的治理措施以改善水体富营养化状况。     

立体生态模式综合治理太湖无锡湾富营养化初探

根据太湖无锡湾的污染现状，针对不同水层采用不同处理方法来控制和改善水体的富营养化，对于表层水，主要种植一些对氮、磷等有机污染物具有高去除率的水生维管束植物和丝状藻类(水葫芦、水网藻等)，对于中层水体，主要放养一些杂食性鱼类及吊养一些蚌类.通过它们的作用，去除水体中过剩的氮、磷等有机污染物，使水体的水质恢复到正常水平，从而改善水体的富营养化，消除蓝藻藻害.与此同时，对底泥较丰富的区域进行清淤，经脱水后堆放在湖中合适的位置，营造湖中人工岛.这一方面可作为旅游资源开发利用，另一方面可作为房地产开发用地.     

3种浮床植物系统对富营养化水体中藻类的抑制效果

以叶绿素a、藻类密度表征水体藻类含量,通过静态试验,研究风车草(Cyperus alterni folius)、菖蒲(Acorus clamus)和富贵竹(Dracaena sanderiana)3种浮床植物系统对富营养化水体中藻类的抑制效果.结果表明:风车草、菖蒲和富贵竹对叶绿素a的平均抑制率分别为42.6%,36....     

冬季巢湖西半湖的富营养化及污染状况研究——基于浮游藻类的多样性分析

通过网格采样法对冬季巢湖西半湖浮游藻类进行科学采集,运用多种方法对浮游藻类的叶绿素含量、个体数量以及群落结构进行了测试、分析与鉴定,补充了巢湖水体中浮游藻类的多样性资料,系统研究了浮游藻类的分布特征.结果表明,浮游藻类叶绿素含量与藻密度呈正相关,两者分布都呈现由河流入湖口和湖中岛屿附近水体向周边降低的变化趋势.浮游藻类群落以蓝藻门为优势门,优势属主要包括微囊藻属、裸藻属、小球藻属、直链藻属和鱼腥藻属.结合多种生物评价方法,如叶绿素含量评价、特征性藻类污染指数评价和藻类群落的多样性指标(Margalef丰度指数、Shannon Weaver多样性指数、Lloyd Ghelardi均匀度指数和优势度指数)评价,对冬季巢湖西半湖的富营养化和污染状况进行了评估.结果表明,巢湖西半湖水体冬季总体处于中度营养和轻度污染的状态,河流入湖口湖区和湖中岛屿附近水体的富营养化和污染程度较高.     

富营养化水体藻类危害及其生物学特性

近年来,富营养化水体大面积爆发,带来极大的危害。本文分析讨论了富营养化水体藻类爆发的危害及其生物学特性。     

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     

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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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has