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地下水资源在社会发展的阶段扮演着至关重要的角色,水是生命之源,但是环境的不断恶化导致地下水资源受到威胁.因此,对地下水进行环境监测是人们日常生活能否正常运行的重要一步.社会发展强调可持续,在地下水资源的发展我们也强调这一点,也在一定程度上促进了经济的发展,地下水资源的妥善管理也在保护着我们的生态环境,因此对水环境进行监测是十分重要的.下面笔者将对地下水环境的现状,要素和监测技术进行分析. 相似文献
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我国是世界上水资源比较贫乏的国家,特别是地下水更加贫乏.而我国煤矿的开采对我国地下水资源造成严重破坏,目前我国半干旱和干旱地下水资源已经因为被煤矿开采破坏而无法修复.文章结合开采煤矿对地下水破坏的现状和影响因素,提出了相应的控制煤矿开采破坏地下水的对策. 相似文献
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《资源节约与环保》2015,(10)
人类的社会生活离不开水资源。地下水是水资源的重要的组成的部分。我国地下水资源丰富,不仅分布广而且水质好,不仅供水保证程度高而且调蓄能力强。经过长时间的大规模开采,我国地下水资源面临着严峻的形势。地下水资源被超量开采,给社会和环境带来了许多不利的影响,在一些地区还诱发了地面沉降等地质灾害。地下水是宝贵的自然资源,是环境的基本要素。为了对水资源进行有效的开发利用,必须对地下水资源进行科学管理。外国发达国家在地下水资源管理方面有着丰富的经验,我们可以借鉴它们的相关经验,加强和完善我国的地下水资源管理。本文介绍了地下水资源在国民经济中的地位与作用和我国地下水资源管理中存在的问题,分析了国外地下水管理经验,提出了加强地下水资源管理的一些措施。 相似文献
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1 沈阳市地下水资源及开发利用状况1 .1 地下水资源状况沈阳市有较好的供水水文地质条件 ,全市地下水埋深较浅 ,易于开采且水质良好 ,地下水补给来源主要是大气降水入渗、河流侧渗、地下径流补给及稻田渠系回归、修建水利工程等。全市多年平均地下水综合补给量为 2 3 .7亿m3,其中降水渗入量占地下水总补给量的 44 .7% ,水田水回归入渗量约占水田总用水量的 30 %— 40 %。多年平均地下水资源可开采量为 1 9.3亿m3,占水资源可利用量的 83 .4% ,由于自 1 999年以来连续遭受干旱 ,2 0 0 1年降水量仅为多年平均值的 65 % ,受大气降水量减少的影… 相似文献
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由于人口增长速度过快,城市化进程也在不断地推进,地下水资源污染比较严重,地下水被污染后,给人类的生存造成威胁,对人类的生产和生活造成影响,因此,我们要采取措施,保护好地下水资源.文章中主要分析了城市地下水污染的状况,描述了地下水污染的特征,对此提出了治污的方法,主要采取防治相结合的方式,来治理城市的地下水的污染情况,从而使之能良好地运行,有效控制城市地下水的污染,使得城市居民能喝上放心水. 相似文献
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森林与径流关系——一致性和复杂性 总被引:17,自引:1,他引:16
@论文综述国外近一个世纪以来在配对集水区研究方面所取得的结论,从水的自然属性出发,从森林变化对径流(年径流量、洪峰与枯水径流)的影响,径流响应的干扰临界值及水文恢复各方面探讨森林变化与径流关系的一致性与复杂性。森林变化与径流关系的一致性主要表现在由较长时间尺度表达的年径流量上。绝大多数的配对集水区的试验研究表明,采伐森林就会增加年径流量,而在荒地上造林就会减少年径流量。而由较短时间尺度表达的洪峰径流与枯水流量则呈现较大的复杂性和难预估性。综述表明,对径流特别是洪峰与枯水径流的定义及分析方法的不同也是造成森林与径流关系复杂性的重要原因。森林与径流关系的复杂性要求人们在研究及应用其关系时就必须有系统观,必须考虑植被、径流与其它过程(土壤变化、气候变化等)的相互作用。论文还认为尽管配对集水区试验作为一种研究方法为研究者提供了许多可靠的结论,但由于许多研究者只把集水区看作是“黑箱”Q从而对认识森林与径流关系的复杂性有一定的局限性。未来的研究应把配对集水区的试验与其它对过程的研究技术(同位素、GIS等技术)结合起来。 相似文献
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Fuellen G 《Die Naturwissenschaften》2008,95(6):469-481
The analysis of the ever-increasing amount of biological and biomedical data can be pushed forward by comparing the data within and among species. For example, an integrative analysis of data from the genome sequencing projects for various species traces the evolution of the genomes and identifies conserved and innovative parts. Here, I review the foundations and advantages of this "historical" approach and evaluate recent attempts at automating such analyses. Biological data is comparable if a common origin exists (homology), as is the case for members of a gene family originating via duplication of an ancestral gene. If the family has relatives in other species, we can assume that the ancestral gene was present in the ancestral species from which all the other species evolved. In particular, describing the relationships among the duplicated biological sequences found in the various species is often possible by a phylogeny, which is more informative than homology statements. Detecting and elaborating on common origins may answer how certain biological sequences developed, and predict what sequences are in a particular species and what their function is. Such knowledge transfer from sequences in one species to the homologous sequences of the other is based on the principle of 'my closest relative looks and behaves like I do', often referred to as 'guilt by association'. To enable knowledge transfer on a large scale, several automated 'phylogenomics pipelines' have been developed in recent years, and seven of these will be described and compared. Overall, the examples in this review demonstrate that homology and phylogeny analyses, done on a large (and automated) scale, can give insights into function in biology and biomedicine. 相似文献
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真菌和细菌对染料的吸附脱色及再生能力的研究 总被引:9,自引:0,他引:9
进行了真菌和细菌共培养对染料的吸附脱色和吸附脱色能力再生的研究。结果表明,青霉菌G-1首先对偶氮染料S-119、蒽醌染料艳紫KN-B(C.I.Reactive violet 22)水溶液中染料进行快速吸附去除,菌丝对同种染料的吸附速度随菌丝培养液中葡萄糖浓度的增加而加快,吸附染料的G-1菌丝在与细菌的共培养中完成对染料的脱色降解,脱色速度受培养液中葡萄和氮源浓度影响较大,从吸附速率和完全脱色时间综合评价,以葡萄糖浓度为5g/L、酒石酸铵为20mmol/L的培养基中培养的菌丝对染料的吸附脱色效果最好,吸附在菌丝上的艳紫KN-B脱色后菌丝吸附脱色能力得到再生,菌丝对100mg/L的艳紫KN-B染料水溶液可重复处理4次。青霉菌G-1对酸性染料废水处理3h,色度去除率为75.9%,吸附染料的菌丝在与细菌共培养中完成对染料的脱色,对试验所用染料废水,菌丝的处理能力获得1次再生。 相似文献
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以泉水来源的伊宁市城市水系,具有特有城市标志的同时对伊宁市起着重要的生态、景观、润泽作用。近年来,城市建设的快速发展给伊宁市水系带来了新的问题。文章以如何保护好伊宁市城市水系为出发点,以现场调查及相关数据为基础,对现状问题进行分析,提出了城市水系保护方面的一些建议对策。 相似文献
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韩文峰 《安全.健康和环境》2011,11(3):40-43
以某联合站为例,根据油气集输联合站站场功能,将联合站划分为油气处理、储运及污水处理3个单元,对各单元发生火灾爆炸事故的可能条件进行分析,并利用DNV公司的SAFETI软件对事故后果进行模拟计算,根据事故影响范围数据,提出相应的安全措施。 相似文献
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Pesticides and trace elements in cannabis: Analytical and environmental challenges and opportunities
Caley B. Craven Nicholas Wawryk Ping Jiang Zhongshan Liu Xing-Fang Li 《环境科学学报(英文版)》2019,31(11):82-93
Cannabis is increasingly used for both medicinal and recreational purposes with an estimate of over 180 million users annually. Canada has recently legalized cannabis use in October 2018, joining several states in the United States of America (e.g., Colorado, California, and Oregon) and a few other countries. A variety of cannabis products including dry flowers, edibles, and oil products are widely consumed. With high demand for cannabis products worldwide, the quality of cannabis and its related products has become a major concern for consumer safety. Various guidelines have been set by different countries to ensure the quality, safety, and efficacy of cannabis products. In general, these guidelines require control of contaminants including pesticides, toxic elements, mycotoxins, and pathogens, as well as residual solvents in regard to cannabis oil. Accordingly, appropriate analytical methods are required to determine these contaminants in cannabis products for quality control. In this review, we focus on the current analytical challenges and method development for detection of pesticides and toxic elements in cannabis to meet various guidelines. 相似文献
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A total of 2931 women randomized to either transabdominal CVS, transceirvical CVS, or amniocentesis were studied. Unless intended or unintended abortion had occurred, they had completed up to 28 weeks of pregnancy. No significant difference was seen between total fetal loss in the transabdominal CVS group and the amniocentesis group (6.5 and 6.8 per cent, respectively, SE difference = 0.92 per cent, p = 0.01). The total fetal loss in the transcervical CVS group was 10.1 per cent. After pooling our data with data from the Canadian randomized study and the American non-randomized study, the difference in risk between trans-cervical CVS and amniocentesis was 1.8 per cent (SE difference = 0.64 per cent, p = 0.8). When the number of failed procedures and those cases evaluated as infeasible for the assigned method-for anatomical reasons-are compared, the overall sampling efficacy is poorer transcervically than transabdominally. 相似文献