介形类生物环境监测与评价研究进展

随着环境污染问题被人重视,生物监测方法得到广泛关注,介形类因具有可反映环境污染且分布广泛等特点被应用于环境监测与评价。本研究详细总结介形类的3种常见毒性实验具体步骤及适用对象:介形类经典急性毒性实验通常用于水体环境安全监测;6 d免培养/免维护直接接触实验用于土壤、沉积物等固体介质毒性研究;14 d慢性毒性实验较多用于道路粉尘毒性安全评估。系统分析国内外利用该生物毒性实验结果,表明介形类死亡率与环境污染呈正相关,明确其对毒物具有较强敏感性,可作为一种良好环境指示生物。     

东洞庭湖介形类现生种的定量生态信息

以东洞庭湖介形类现生种为研究对象,对其进行野外生态调查,获取该生物定量生态信息,以此为该湖水体污染程度监测与评价奠定必要基础,同时丰富我国介形类现生种生境数据。本研究共发现东洞庭湖介形类现生种4属4种,它们为比利时舍氏玻璃介(相似种)Schellencandona cf.belgica、豆形豆形玻璃介Fabaeformiscandona fabaeformis、克氏丽星介 Cypria kraepelini及喙盲星介(相似种)Typhlocypris cf.rostrata,前三种为主要分子,T.cf.rostrata仅少量出现,未发现地方种。该湖介形类属种数量春季明显少于秋季,与太湖该生物属种数量季节分布相似。C.kraepelini与F.fabaeformis比S.cf.belgica与T.cf.rostrata可能具更强的抗污能力,水体重金属污染对介形类生存造成了明显不利影响,表明可利用该生物敏感指示水体重金属污染状况。     

重金属联合毒性对蚤类与鱼类敏感性的影响及预测模型研究进展

通过阅读文献了解各类重金属在联合作用情况下对水生生物产生的毒性效应并讨论了联合毒性的作用机制。研究了水环境中重金属污染对水生生物的敏感性影响,介绍了联合毒性作用的具体表现形式,总结了包括蚤类、鱼类等常见水生生物的收集与培养、联合毒性实验的具体步骤与结果讨论,对联合毒性的两种基本模型原理与预测结果进行了阐述。结果表明,水生生物存活率与重金属污染程度有着直接关系,重金属在联合作用时能够表现出不同的毒性影响。     

浅谈重金属在线监测设备的应用

随着工农业的迅速发展,我国的重金属污染事件频频发生。重金属具有毒性大,在环境中不易被分解、易被生物富集并有生物放大效应等特点,重金属污染已经导致了严重的环境问题和社会问题,并对人类的健康造成威胁,重金属的准确快速监测变得十分迫切。结合重金属在线监测的迫切需求,对重金属检测技术进行了介绍,对重金属在线分析采用的化学比色法和电化学方法作了较为详细的阐述,并对重金属在线监测技术未来的发展趋势进行了预测。     

底泥中持久性有毒物质研究现状与展望

将持久性有毒物质(PTS)分为持久性有机污染物(POPs)和重金属两类.分别慨述了这两类PTS在底泥中的来源与进入的方式;指出它们具有长期残留性、生物累积性、半挥发性和高毒性特征.重点分析了PTS在生态系统中的循环,对生物的生殖及器官的危害;介绍了监测POPs的4种化学仪器分析方法与生物分析方法,监测重金属的化学与生物...     

利用小球藻监测污染水体中重金属污染和小球藻对重金属的吸附效应研究

本文利用藻类生长抑制试验方法进行试验,探讨了污染水体中重金属对普通小球藻生长的影响,及普通小球藻对污染水体中重金属的吸附作用,为污染水体的生物监测提供科学的数据支撑,利用水生生物检测水质的同时检测水体中藻类的群落变化,全面监测水质变化。结果表明:高浓度的重金属污染会抑制藻类细胞的生长,小球藻对水体中的一些重金属离子等污染物具有较好的吸附与去除作用。     

应用微生物发光法检测水体中的砷、镉、铬污染

采用细菌发光抑制实验,研究水体中As3+、Cd2+、Cr6+3种重金属的单一毒性和联合毒性.研究发现,在一定剂量范围内,As3+、Cd2+、Cr6+浓度与相对发光强度呈负相关;根据处理液对细菌发光强度的抑制效应,3种重金属的毒性大小依次为As3+>Cr6+>Cd2+,2种或3种重金属的联合毒性明显大于单一毒性,表现为相加或协同作用.研究结果表明,在一定浓度范围内,细菌发光强度的变化与重金属浓度具有剂量-效应关系,可利用发光细菌对水体重金属污染进行监测.     

重金属Zn、Cu和Hg对基因重组发光菌的综合毒性及其联合效应

本文主要分析了三种常见重金属(Zn2+、Cu2+、Hg2+)对基因重组发光菌(E. coli HB101 pUCD607)的单一毒性和不同浓度比下的联合毒性作用,并采用毒性单位法(Toxic Unit)、Marking相加指数法(Additional Index)和混合毒性指数法(Mixture Toxicity Index)来评价混合体系的联合毒性作用类型。Zn2+、Cu2+和Hg2+三种的重金属对发光细菌的15分钟半数效应浓度(EC50)分别为:4.16、6.00和0.98mg/L。多元重金属混合体系主要呈现不同程度的拮抗作用,不同的评价方法对3种重金属的联合效应评价结果具有较好的一致性。上述重金属联合毒性作用可为重金属复合污染控制和生物毒性测试提供参考。     

重金属急性毒性研究进展

由于人类对重金属的开采、冶炼、加工及其他工业制造活动的日益增多,使得重金属人为地扩散进入大气、水、土壤中,从而引起严重的环境污染。重金属污染目前正成为一个全球范围内的广泛关注的焦点。特别是在我国,随着近年来经济的快速发展,相应产生的重金属污染已经到了不可忽视的地步。本文介绍了近年来国内外重金属毒性的研究进展,并着重介绍重金属对不同生物的毒性效应及差异以及不同重金属对同一生物的毒性差异。并对目前国外有关重金属的毒性测试标准以及生态评估做了简要介绍。     

共存重金属和含氧阴离子对U(VI)生物沉淀过程的影响

以硫酸盐还原菌生物还原法消除模拟地浸废水中的放射性铀污染,分别研究了主要共污染离子Zn2+、Cu2+、SO42-和NO3-对铀生物沉淀过程的影响。厌氧序批式实验结果表明,初始Cu浓度低于10 mg/L或Zn浓度低于20 mg/L时对铀生物沉淀过程影响不大,当初始Cu浓度超过15 mg/L或Zn浓度超过25 mg/L时,该过程会因重金属的生物毒性作用被完全抑制。初始SO42-浓度低于4000 mg/L时对铀生物沉淀过程影响很小,超过5000 mg/L时会产生明显的抑制作用,且抑制作用随着SO42-浓度的上升而加强。研究还表明,含有NO3-的氧化性环境不利于铀的生物沉淀过程,通过反硝化反应彻底去除环境中的NO3-成为消除环境中铀污染的前提。本实验结果可望为我国核污染水环境的修复提供生物技术思路。     

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.     

A computer generator for randomly layered structures

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

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

正~~     

An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

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.     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.