我国油田土壤重金属污染与修复的研究现状

简要阐述了当前我国油田土壤重金属污染的现状及特征,并分析了其来源和危害;综述了土壤重金属污染修复的相关技术方法,并着重介绍了生物修复及其发展前景;同时对油田防治重金属污染提出了两点建议,指出土壤重金属污染的防治要以预防为主,以期实现油田的生态文明。     

土壤重金属污染的治理途径及其研究进展

由于工业“三废”的排放，使农田遭受不同程度重金属的污染，重金属通过在作物体内富集进入食物链，对人畜健康构成了威胁，章对土壤重金属的污染现状、治理途径及其原理、优缺点、可行性作了简要的回顾，对土壤重金属污染植物修复技术类型、原理、特点以及基因工程等现代生物技术在镉污染植物修复技术中的应用前景作了进一步的展望，为实现对重金属污染土壤进行有效的生态整治与安全高效益的利用提供了新的技术途径。     

抚顺西露天矿区土壤重金属污染及潜在风险评价

通过对矿区地上典型区域土壤重金属含量的测定,确定了Cd是矿区土壤中重金属污染的特征元素;利用单因子污染指数法、内梅罗污染指数法和潜在生态危害指数法评估该区域土壤重金属污染程度和潜在生态风险.结果表明: Cd的单元素污染负荷指数和内梅罗污染指数平均值分别为4.06和5.32,属于重度污染水平.3个生态修复区域的内梅罗污染指数在2.07~4.57之间,其中南帮自然生态恢复区(SNER)属于重度污染,其他区域为中度污染;矿区土壤重金属潜在生态风险指数介于98.62~224.55之间,SNER区域达到中等危害水平,其余区域为轻度生态危害.     

论土壤重金属污染修复技术研究进展

本文主要简述重金属在土壤中的存在形态以及对动植物和人的危害机理,分别从植物修复,微生物修复,化学修复和物理修复几方面介绍进年来重金属污染土壤的修复技术和最新研究进展,对这些修复技术的原理,实例和优缺点进行阐述和对比,以求为重金属污染土壤修复工作的实施提供一些理论依据。     

矿区土壤重金属污染修复技术研究进展

本文分析了土壤重金属污染较严重的几种典型矿区的污染来源及污染现状,发现金属矿区的重金属污染较煤矿区污染更为严重,往往为多金属复合污染,修复较为困难,土壤重金属污染的治理已刻不容缓。并重点评述了应用于矿区重金属污染土壤主要修复技术的国内外研究现状,了解到土壤淋洗技术、土壤固定化技术、植物修复技术和多种修复技术相结合的复合修复技术为现今国内外研究的重点。在此基础上指出了我国在今后的矿区土壤重金属修复方向的研究重点为高效环保的土壤添加剂的研究,超累积植物或大生物量重金属富集植物的筛选和培育以及土壤修复技术的高效联合使用。     

金沙江攀枝花河段土壤重金属污染状况及生态风险评价

为清晰了解金沙江攀枝花河段土壤重金属污染状况，以丰、平、枯不同水期下金沙江攀枝花河段岸边土壤为研究对象，采用单因子污染指数法、内梅罗综合污染指数法以及潜在生态风险指数法对金沙江攀枝花河段土壤重金属污染状况以及可能存在的生态风险进行评价，并提出了相关风险管控建议.研究结果表明，丰、平、枯不同水期下V,Cd, Cu, Ni等重金属质量含量均值超过四川省表层土壤背景值；丰水期与枯水期下重金属内梅罗综合污染指数均值分别为3.10,3.14,综合污染等级达到Ⅴ级重度污染，平水期下重金属内梅罗综合污染指数均值为2.94,综合污染等级达到Ⅳ级中度污染，土壤中Cd, V污染值得进一步关注；丰、平、枯不同水期下金沙江攀枝花河段岸边土壤重金属的潜在生态风险系数均值分别为144.04,110.88和147.15,总体呈现轻微生态风险，重金属Cd存在的危害较为严重，潜在生态风险指数分别为103.92,84.81和111.71,呈现强生态风险，Cd存在的生态风险值得进一步去关注.     

土壤重金属污染治理与修复方法研究进展

土壤重金属污染的治理和修复的基本原理是将重金属清除或改变其在土壤中的存在形态,降低迁移性和生物可利用性。根据土壤的性质和重金属在土壤中的赋存形态不同,目前重金属污染土壤治理和修复方法可分为工程物理化学法、土壤农化调控法和生物学修复法。通过对重金属污染治理与修复方法的综述,得出了各种方法的优缺点和适用范围,并对重金属治理的方法进行了展望。     

植物对重金属污染土壤的生态修复

为了有效修复和美化污染的土壤环境,降低重金属的污染,筛选4种植物,通过重金属含量检测法、抗性菌检测、微生物群落分析法和土壤酶活性等研究方法,提取菌根孢子;分离重金属抗性菌;检测土壤中菌脲酶、过氧化氢酶、脱氢酶、碱性磷酸酶含量和土壤微生物数量;酶活性显著变化、重金属抗性菌抗性降低、生态多样性增加。研究结果表明所筛选是植物对重金属污染的土壤有较好的修复作用,为营建景观技术研究的提供了科学的依据。     

土壤重金属的污染与治理进展研究

土壤重金属是土壤环境污染最主要的一个方面.介绍了重金属污染的特点和危害机理,并针对污染途径提出了"减源""截流"和"修复"治理措施,控制流入环境中的重金属的绝对值;重点介绍了土壤重金属污染修复的各种方法.     

重金属污染对土壤动物的影响

讨论了土壤重金属污染的内涵,从酶活性和分子结构两方面来说明重金属对土壤动物危害的机理。重金属对土壤动物机体酶活性产生诱导和抑制作用,重金属会破坏组织细胞的微结构,使土壤动物的群落结构呈现简单化和不稳定化,土壤动物对重金属的防御,主要包括土壤动物的特殊解毒策略和回避策略,可通过释放土壤动物来修复被重金属污染的土壤。     

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-