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1.
内蒙古乌梁素海生态恢复工程试验研究   总被引:2,自引:0,他引:2  
在典型草型富营养化湖泊内蒙古乌梁素海设立试验研究基地,进行较大规模的生态恢复工程试验,研究表明实施沉水植物收割工程是草型富营养化湖泊生态恢复的重要技术措施.以机械化方式收割沉水植物能够削减湖泊内源性营养物负荷的积累和释放,减少二次污染,抑制生物填平作用,改善水体环境.有计划、合理地运用生态恢复工程,不仅可以减轻草型湖泊所面临的巨大生态压力,延缓沼泽化演化进程,而且可以在实施生态工程的同时开发利用水生植物资源,使湖泊环境与湿地综合利用得到持续发展.  相似文献   

2.
富营养化浅水湖泊修复探讨——以巢湖水环境修复为例   总被引:1,自引:0,他引:1  
以巢湖为例,总结了营养化浅水湖泊富营养化的主要原因,并结合实际情况,提出了修复措施为污染源控制及生态恢复。污染源控制包括外源污染物控制及内源污染物清除。生态恢复的核心为在发展沉水植物的基础上,重建以生态湿地为主的生态群落。  相似文献   

3.
以典型干旱区草型湖泊乌梁素海湿地为研究区,在实地调查和试验的基础上,依据资源经济学和生态经济学的理论和方法,针对乌梁素海湿地资源的特点,对乌梁素海湿地的价值进行了货币化评估.评估结果表明:乌梁素海湿地的总价值为28.24亿元,,非使用类价值为17.51亿元.  相似文献   

4.
针对我国日益严重的水体富营养化现象,从物理化学、生物和水力学三个方面对国内外富营养化和水华控制技术的研究现状进行了综述。结果表明,基于理性的氮磷营养物控制策略仍是水体富营养化控制的优先策略,科学合理的水力调度对库湾水体、城市河道抑制富营养化和控制藻类生长具有重要作用,传统的物理和化学方法及生物技术在小范围水华应急和水质维持较为有效,但一些方法的生态安全性及理论依据仍需加强研究。实际水体修复过程中仍需要不断调整方法以适用不同水体需求。  相似文献   

5.
 本文综述了沉水植物对富营养化水体及其他受污水体中的N、P、重金属和有机物的去除,及抑制藻类生长化感等作用的研究的进展,并分析沉水植物对其的去除率,沉水植物在水域生态修复中较高的应用价值,同时指出沉水植物净化水质中存在的问题,展望了沉水植物净化水质的前景及方向。  相似文献   

6.
南湖富营养化主要控制因子分析   总被引:4,自引:0,他引:4  
分析了南湖湖水中营养物之间、营养物与藻类生长之间的相互关系,探讨了各种环境因子对南湖富营养化的影响.结合藻类增长潜力试验结果,确定南湖富营养化的主要控制因子,为南湖的综合整治提供科学依据.  相似文献   

7.
乌梁素海是内蒙古高原干旱区最典型的浅水草型湖泊也是该区富营养化最为严重的浅水草型湖泊.本研究选择当地居民日常生活中经常食用的蔬菜进行浮床栽培正交试验,从而为乌梁素海富营养化生态修复与治理提供理论依据与实验技术支撑.研究显示:香芹(Petroselinum crispum)和菠菜(Spinacia oleracea)不适于浮床栽培,空心菜(Ipomea aquatica)吸收能力强对各营养水平富营养化水体的净化都有较好的效果.木耳菜(Basella rubra)效果较空心菜差.莜麦菜(Lactuca sativa var.)和生菜(Lactuca sativa)都比较适于春秋季节栽培,莜麦菜与空心菜相比耐贫瘠,更适于中度富营养化水体的净化.浮床的栽培时间根据水体的营养水平可适当不同,高营养水平的时间可以适当延长,而中、低营养水平的则应适当缩短.中度富营养水平的乌梁素海可以应用此技术进行恢复治理.  相似文献   

8.
本实验利用淮北东湖污染水体、沉积物与沉水植物黑藻.通过室内36 d的人工模拟生态培养实验,研究了沉水植物生长过程对间隙水中NH4+-N和PO43--P浓度的动态影响,结果表明:随黑藻生长和生物量增加,污染沉积物间隙水中NH4+-N含量逐步降低,表现出沉积物-水界面氮的释放通量与黑藻生物量存在负相关性;间隙水PO43--P含量则随沉水植物生长同样呈衰减的变化趋势,磷释放通量与黑藻生物量同样存在负相关性.反映沉水植物在沉积物的生长过程中对氮磷吸收的生物地球化学机制是相似的.恢复污染湖泊水生植物生态系统是治理、调节和抑制湖泊富营养化的有效途径之一.  相似文献   

9.
长江流域重点湖泊的富营养化及防治   总被引:1,自引:0,他引:1  
 近几十年,湖泊富营养化问题严峻,限制了流域社会经济可持续发展。为实施长江大保护,修复长江生态环境,推动长江经济带可持续发展,沿程湖泊富营养化问题亟需解决。本文以长江水系沿程6个重点湖泊为对象,探讨其富营养化历史演变特征、成因及控制对策。结果表明,长江流域6个主要湖泊的富营养化指数在近几年基本呈逐渐降低趋势,富营养化程度得到进一步改善。富营养化成因复杂,外源输入与内源释放是其主要原因,湖泊形态与水文条件也起了辅助作用:6个湖泊都是浅水湖泊,且多为封闭或半封闭状态,利于营养物质积累与藻类生长。对于外源中工业和生活源输入,其控制措施相对成熟,通过扩建污水处理厂、提高污水处理率及完善配套管网建设等措施,可大大减少入湖营养物含量;而外源中的面源污染则需通过种植结构调整、平衡施肥、生态工程(湿地、塘等)防治。对于内源释放,其治理过程相对复杂,目前主要有底泥疏浚、沉积物氧化、化学沉淀、底泥覆盖、微生物制剂、生物浮床等多种物理化学生物方法。但不同湖泊因其物理化学条件差异,适用方法也不同,故各湖采取的内源控制技术有待进一步论证。控制湖泊内外源营养盐输入的同时,进行流域生态修复并保障治理与管理并重,才能确保湖泊富营养化治理的长期有效性。  相似文献   

10.
对沈阳辉山水库流域工业、生活、农业及地面径流污染源进行了详细调查,监测和分析了水质和底泥质量,并有针对性地探讨了生态整治方案.结果显示:辉山水库流域主要污染源为生活源和农业源,每年入库污染量约为CODcr 400吨、总氮6 200吨、总磷700吨、污水120万吨、粪尿4700吨、固废200吨;水库流域水质类别为劣Ⅴ类,为重度污染,水库重度富营养化;底泥受到不同程度富营养化污染,并且辉山明渠起点采样点重金属总铅含量不合格;生态整治方案能改善辉山水库流域环境质量,实现生态流域和景观流域完美结合.  相似文献   

11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
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。  相似文献   

16.
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.  相似文献   

17.
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-  相似文献   

18.
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-  相似文献   

19.
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  相似文献   

20.
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  相似文献   

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