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1.
硒汞相互作用研究在过去近半个世纪以来一直都是汞(硒)环境化学和毒理学及相关学科研究的重要领域之一,尤其在近10年内,对该领域的研究和认识取得了重要突破, 国际上几乎每年都会出现与之相关的综述或评论。相比之下,国内期刊报道与之相关的综述文献并不多见。本文对这一领域的研究进展进行了尽可能详尽的系统介绍,并就重要问题阐述了相关观点并提出建议。内容上涵盖了"自然条件环境下硒汞相互作用及机理(包括水生生态系统和陆地生态系统)"、"哺乳动物(及人体)的硒汞相互作用及机理",以及"汞污染风险的新评估模式及相关建议"等三大部分。希望能对国内感兴趣的相关科研人员和环境管理工作者了解该领域的发展和动态起到一定的帮助。  相似文献   

2.
干旱和半干旱荒漠矿区环境问题与治理对策   总被引:1,自引:0,他引:1  
介绍了我国西部干旱和半干旱荒漠地区的煤炭在长期的开发活动中引发的一系列的环境问题。通过对这些问题的分析,提出了系统性、持续性的环境保护对策,以使荒漠矿区的环境得到持续性改善,实现可持续发展。  相似文献   

3.
PhotochemistryofchryseneadsorbedonseveraltypesofparticleZhongJinxian;MauldinR.F.;Dunstan,T.D.T,Sanders,J.K.,Hipps,A.D.,Wehry,...  相似文献   

4.
端头多半圆弯曲件比较常见,但质量难以保证。此文通过对成形弯曲工艺的分析,提出了改进措施,并介绍了两种典型模具结构,及其零部件的设计。  相似文献   

5.
丁冰  陈健  王彬  伊力塔 《地球与环境》2016,44(1):130-138
随着城市化和工业化的发展,城市环境中日益增多的PM_(2.5)对人类健康造成了严重威胁。本文旨在分析总结目前PM_(2.5)空间分布的相关监测方法以及空气质量预测模型。当下,PM_(2.5)浓度的监测不仅涉及大气化学、污染物的源解析、大气化学运输模型、线性及非线性空气质量模拟等方面,还涉及地理信息系统与卫星遥感等新技术的运用。本文在比较传统PM_(2.5)监测与新型监测方法不同的基础上,分析了各自的优劣,为空气质量监测提供建议和指导。  相似文献   

6.
高水分蔬菜废物和花卉废物批式进料联合堆肥的中试   总被引:9,自引:2,他引:9  
以滇池流域典型农业废物蔬菜(西芹)和花卉废物(石竹)为原料,进行了2种配比的蔬菜废物和花卉废物联合堆肥的中试研究.堆肥一次发酵采用批式进料温度反馈通气量控制的静态好氧技术,发酵周期15d.对于西芹与石竹废物各占一半的堆肥试验,在一次发酵阶段,堆体温度在55℃以上保持10d,最高温度达65℃,可有效杀灭致病菌,堆体含水率从64.2%减少为46.3%,有机质含量从74.7%下降到55.6%,体积减少为原来的一半,pH值稳定在7左右.二次发酵采用周期性翻堆,自然腐熟,周期30d.对堆肥产物的腐熟度和养分分析表明,堆肥产物稳定性好,养分含量高.这表明,采用温度反馈通气量控制的静态好氧堆肥技术,蔬菜废物和花卉废物联合堆肥可以在45d内获得高质量的堆肥产品,将堆肥产品返还土壤能有效减少固体废物非点源污染、提高土壤肥力.  相似文献   

7.
节能分析篇(章)在工业固定资产投资项目节能评估和审查中占有重要的地位,节能分析篇(章)是否全面、是否规范不仅决定了项目节能评估和审查的最终结论,也对项目投运后的能源管理产生着决定的作用。文章针对某重型机械有限公司大型高效水、火、核电及轧辊等大型轴类锻件加工基地建设项目节能分析情况进行了探讨。  相似文献   

8.
本文在系统分析珠江三角洲水环境水资源特点与经济发展需求的基础上,按照确保水源与合理利用水环境容量并重的原则,提出了三角洲各城市的供水与污水控制的总体布局。这种按水系的整体性确定区域各城市水污染整治战略的方法,对经济开发强度大的地区是普遍适用的,可以收到事半功倍的效果。   相似文献   

9.
Environmental Impact Assessment (EIA) is an important tool to help decision-makers balance the environmental impacts of a proposed built development with its potential economic benefits. Used in most countries across the globe, EIA commonly includes an ecological component (Ecological Impact Assessment, or EcIA). However, despite considerable changes in relevant legislation, policy and guidance, there has been no recent review of UK EcIA chapter content, with the latest review having been published in 2000.This study attempts to determine the procedural effectiveness of EcIA chapters over time by comparing a new review of 112 English EcIA chapters from 2000 onwards with earlier reviews. This was achieved through the novel use of inferential statistics, an approach previously lacking in the EIA and EcIA review literature.The limitations and advantages of the use of quantitative methods are discussed. In general, there has been an improvement in the information content of EcIA chapters over time, for example in the percentage of EcIA chapters stating the size of the development and estimating the likely effectiveness of proposed mitigation measures. However, the earlier reviews highlighted such severe information deficiencies that the progress seen in the post-2000 EcIA chapter review still leaves considerable scope for improvement.Changes in the EU’s EIA Directive in force since May 2014 (and to be transposed into Member State legislation by May 2017) have the potential to encourage the use of inferential statistics in EIA and EcIA review: the requirement for Member States to provide central access to EIA information should enable representative samples to be analysed.  相似文献   

10.
天山污水厂除臭工程试验研究   总被引:2,自引:0,他引:2  
介绍了上海天山污水厂污泥浓缩池采用天然植物提取液进行除臭的试验研究,针对污泥产生的恶臭气体,复配的天然植物提取液经净化器挥发后,在半封闭的空间内实现了H2S气体平均去除率96%以上,彻底改善了周边居民的生活环境.  相似文献   

11.
12.
High-performance permanent magnets   总被引:2,自引:0,他引:2  
 High-performance permanent magnets (pms) are based on compounds with outstanding intrinsic magnetic properties as well as on optimized microstructures and alloy compositions. The most powerful pm materials at present are RE–TM intermetallic alloys which derive their exceptional magnetic properties from the favourable combination of rare earth metals (RE=Nd, Pr, Sm) with transition metals (TM=Fe, Co), in particular magnets based on (Nd,Pr)2Fe14B and Sm2(Co,Cu,Fe,Zr)17. Their development during the last 20 years has involved a dramatic improvement in their performance by a factor of >15 compared with conventional ferrite pms therefore contributing positively to the ever-increasing demand for pms in many (including new) application fields, to the extent that RE–TM pms now account for nearly half of the worldwide market. This review article first gives a brief introduction to the basics of ferromagnetism to confer an insight into the variety of (permanent) magnets, their manufacture and application fields. We then examine the rather complex relationship between the microstructure and the magnetic properties for the two highest-performance and most promising pm materials mentioned. By using numerical micromagnetic simulations on the basis of the Finite Element technique the correlation can be quantitatively predicted, thus providing a powerful tool for the further development of optimized high-performance pms.  相似文献   

13.
Arsenic (As) is ubiquitous in the environment in the carcinogenic inorganic forms, posing risks to human health in many parts of the world. Many microorganisms have evolved a series of mechanisms to cope with inorganic arsenic in their growth media such as transforming As compounds into volatile derivatives. Bio-volatilization of As has been suggested to play an important role in global As biogeochemical cycling, and can also be explored as a potential method for arsenic bioremediation. This review aims to provide an overview of the quality and quantity of As volatilization by fungi, bacteria, microalga and protozoans. Arsenic bio-volatilization is influenced by both biotic and abiotic factors that can be manipulated/elucidated for the purpose of As bioremediation. Since As bio- volatilization is a resurgent topic for both biogeochemistry and environmental health, our review serves as a concept paper for future research directions.  相似文献   

14.
长沙大气降水中稳定同位素变化及过量氘指示水汽来源   总被引:3,自引:1,他引:2  
基于2010 年1 月1 日至2012 年5 月31 日长沙日降水同位素资料,对长沙降水中稳定同位素、过量氘(记为d) 的变化特征以及它们与降水、温度和湿度的关系进行了分析。研究发现:①在季风系统下, 降水中稳定同位素、d 均具有明显的季节变化,表现出夏半年的低值与冬半年的高值交替变化的特点;②降水中稳定同位素在不同时段均存在降水量效应和湿度效应,另外,夏半年中表现为反温度效应,冬半年则表现出温度效应;③综合考虑降水中d 和δ18O 与大气湿度的关系, 可认为影响长沙降水中稳定同位素变化的主要原因与降水的气团性质有关。夏半年中,夏季风盛行,降水的水汽主要来源于西南季风、东南季风所携带的海洋水汽,空气湿度大,d 小,重同位素在水汽输送过程中因不断冷凝而大大贫化,从而降水中δ18O(δD) 较小;冬半年中,长沙受大陆性气团控制,降水的水汽则主要来源于西风带及当地蒸发,空气湿度小,降水中δ18O(δD) 以及d 均较高。  相似文献   

15.
To understand the effects of long-term amendment of organic manure and N fertilizer on N2O emission in the North China Plain, a laboratory incubation at different temperatures and soil moistures were carried out using soils treated with organic manure (OM), half organic manure plus half fertilizer N (HOM), fertilizer NPK (NPK), fertilizer NP (NP), fertilizer NK (NK), fertilizer PK (NK) and control (CK) since 1989. Cumulative N2O emission in OM soil during the 17 d incubation period was slightly higher than in NPK soil under optimum nitrification conditions (25℃ and 60% water-filled pore space, WFPS), but more than twice under the optimum denitrification conditions (35℃ and 90% WFPS). N2O produced by denitrification was 2.1-2.3 times greater than that by nitrification in OM and HOM soils, but only 1.5 times greater in NPK and NP soils. These results implied that the long-term amendment of organic manure could significantly increase the N2O emission via denitrification in OM soil as compared to NPK soil. This is quite different from field measurement between OM soil and NPK soil. Substantial inhibition of the formation of anaerobic environment for denitrification in field might result in no marked difference in N2O emission between OM and NPK soils. This is due in part to more rapid oxygen diffusion in coarse textured soils than consumption by aerobic microbes until WFPS was 75% and to low easily decomposed organic C of organic manure. This finding suggested that addition of organic manure in the tested sandy loam might be a good management option since it seldom caused a burst of N2O emission but sequestered atmospheric C and maintained efficiently applied N in soil.  相似文献   

16.
Agrobiodiversity with emphasis on plant genetic resources   总被引:1,自引:0,他引:1  
The science of agrobiodiversity has emerged during the last 10 years. We review here the most important aspects of biodiversity for conservation. One of the aims of agrobiodiversity research is to introduce or to re-introduce into present-day agriculture and horticulture more diversity from gene banks, botanical or zoological gardens, and other secondary sources of diversity. To enlarge the basis of agricultural and horticultural resources for human and animal nutrition, a sustainable use of these native and cultivated resources is necessary, including animal and plant genetic resources. The total number of botanical plant species cultivated as agricultural or horticultural crops is estimated at almost 7,000. However, only 30 major crop species "feed the world". Comparable numbers of animal species have been lost. The reduction in crop species and variety diversity, in particular, has led to the establishment of germplasm collections, so called gene banks, or ex situ collections. Six million plant accessions are conserved in gene banks worldwide. All these accessions belong to a very limited number of species. About half of them are advanced cultivars or breeders' lines, and only a third are landraces or old cultivars. Approximately 15% are wild relatives of crop species and weeds. Among other obvious gaps, minor crops and underutilized species are underrepresented in these collections, particularly primitive cultivars and wild relatives from the centers of origin, diversity, and cultivation. To date, only a third of all gene bank accessions have been fully characterized.  相似文献   

17.
Evolutionary theory has been likened to a “universal acid” (Dennett 1995) that eats its way into more and more areas of science. Recently, developmental biology has been infused by evolutionary concepts and perspectives, and a new field of research—evolutionary developmental biology—has been created and is often called EvoDevo for short. However, this is not the first attempt to make a synthesis between these two areas of biology. In contrast, beginning right after the publication of Darwin’s Origin in 1859, Ernst Haeckel formulated his biogenetic law in 1872, famously stating that ontogeny recapitulates phylogeny. Haeckel was in his turn influenced by pre-Darwinian thinkers such as Karl Ernst von Baer, who had noted that earlier developmental stages show similarities not seen in the adults. In this review, written for an audience of non-specialists, we first give an overview of the history of EvoDevo, especially the tradition emanating from Haeckel and other comparative embryologists and morphologists, which has often been neglected in discussions about the history of EvoDevo and evolutionary biology. Here we emphasize contributions from Russian and German scientists to compensate for the Anglo-American bias in the literature. In Germany, the direct influence of Ernst Haeckel was felt particularly in Jena, where he spent his entire career as a professor, and we give an overview of the “Jena school” of evolutionary morphology, with protagonists such as Oscar Hertwig, Ludwig Plate, and Victor Franz, who all developed ideas that we would nowadays think of as belonging to EvoDevo. Franz ideas about “biometabolic modi” are similar to those of a Russian comparative morphologist that visited Jena repeatedly, A. N. Sewertzoff, who made important contributions to what we now call heterochrony research—heterochrony meaning changes in the relative timing of developmental events. His student I. I. Schmalhausen became an important contributor to the synthetic theory of evolution in Russia and is only partly known outside of the Russian-reading world because only one of his many books was translated into English early on. He made many important contributions to evolutionary theory and we point out the important parallels between Schmalhausen’s ideas (stabilizing selection, autonomization) and C. H. Waddington’s (canalization, genetic assimilation). This is one of the many parallels that have contributed to an increased appreciation of the internationality of progress in evolutionary thinking in the first half of the twentieth century. A direct link between German and Russian evolutionary biology is provided by N. V. Timoféeff-Ressovsky, whose work on, e.g., fly genetics in Berlin is a crucial part of the history of evo-devo. To emphasize the international nature of heterochrony research as predecessor to the modern era of EvoDevo, we include Sir G. R. de Beer’s work in the UK. This historical part is followed by a short review of the discovery and importance of homeobox genes and of some of the major concepts that form the core of modern EvoDevo, such as modularity, constraints, and evolutionary novelties. Major trends in contemporary EvoDevo are then outlined, such as increased use of genomics and molecular genetics, computational and bioinformatics approaches, ecological developmental biology (eco-devo), and phylogenetically informed comparative embryology. Based on our survey, we end the review with an outlook on future trends and important issues in EvoDevo.  相似文献   

18.
Energy efficiency in the Japanese industry is one of the highest in the world. As a consequence, reduction of CO2 emissions is considered to be difficult and costly. However little attention has been paid as of yet to changes related to so-called non-energy use of fossil fuels. The analysis in this paper suggests that a large number of options exist for emission reduction in the Japanese petrochemical industry. This includes the introduction of biomass feedstocks, the introduction of new catalytic production processes, and changes in waste handling. The use of bioplastics and the use of CO2 feedstocks seem costly options for GHG emission reduction that should not be applied on the short term. Japanese GHG emissions can be reduced by 7.7% if the optimal set of emission mitigation options is applied. About 60 Mt emission reduction (4.9%) can be achieved by changes on the supply side, another 35 Mt emission reduction (2.8%) can be achieved by changes in waste management. While changes in waste management can be implemented before 2010, biomass introduction on the supply side will probably require a longer lead-time. About half of the emission reduction is cost–effective, but will require further technology development. The other half can be achieved at a cost level of 10,000 yen/t CO2 (80 US$/t CO2). The latter part is based on proven technology that is currently not cost–effective.  相似文献   

19.
SWOT分析法在城市环境规划中的应用——以安庆市为例   总被引:1,自引:0,他引:1  
基于优势、劣势、机会、威胁的SWOT分析法能将内部条件和外部环境结合,运用于城市环境规划。文章采用模糊综合评判法、矩阵分析法、价值工程、四半维平面坐标、强度梯度等数学方法,构建了适合于城市环境规划的SWOT定量模型,并以安庆市为例,引入该模型对城市环境规划进行指导,找出安庆市环境规划的发展方向和相应对策,为该市可持续发展提供理论支持。  相似文献   

20.
行政办公室内PBDEs污染特征及人体暴露量   总被引:1,自引:0,他引:1  
为研究普通行政办公场所内多溴联苯醚(PBDEs)的污染现状、同类物分布特征及办公人群吸入暴露量,于2013年3月~8月期间在杭州市行政办公场所采集20个空气样品,用GC-ECD分析样品中14种PBDEs同类物.结果发现:杭州市办公场所空气中PBDEs总平均浓度达9.57×102pg/m3,与欧洲国家相比处于较高污染水平,其中BDE-209是主要污染成分,占总含量的57.4%,说明杭州市办公场所PBDEs的主要工业品来源是十溴联苯醚.与家庭住宅空气样品对照发现,办公场所PBDEs平均浓度是家庭住宅的1.26倍,并且这一浓度差异主要体现在BDE-209单体上.办公场所各采样点同类物气固相对百分含量在50.0%左右,说明空气中PBDEs一半以气态形式存在,一半则吸附在空气颗粒物中,这可能是PBDEs气固分配还未平衡所致.此外,杭州市普通行政办公人群BDE-99的总摄入量为2.03′102pg/(kg×d),比国际标准BDE-99每日允许摄入量低21.7%.  相似文献   

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