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151.
内蒙古乌兰浩特索伦镇地区中生代侵入岩特征研究   总被引:1,自引:0,他引:1  
内蒙古乌兰浩特索伦镇地区位于大兴安岭中南段。该区中生代侵入岩广泛发育。开展侵入岩的年代学、地球化学特征研究能为深入探讨区域构造背景提供依据。3个样品K-Ar全岩法测年结果(93.39Ma~108.48Ma)证明侵入岩形成于早白垩世,略晚于其南侧同一构造带上的杜尔基地区侵入岩年龄(100.15Ma~120.29Ma),符合太行山——大兴安岭早白垩世侵入岩时代自南向北由老变新的演化趋势。岩石地球化学分析结果显示岩石属于碱性系列,具有高硅、高钾、富碱、过铝、贫钙、镁、铁等特征。稀土元素总量为(77.96~241.29)μg/g,平均值为158.92μg/g,与杜尔基地区早白垩世侵入岩的稀土总量平均值(146.85μg/g)及华北克拉通内碱性系列岩石的稀土总量平均值(163.32μg/g)都非常接近。稀土元素球粒陨石标准化曲线整体右倾,因Eu负异常而呈"V"型形态,与太行山-大兴安岭地区早白垩世典型岩体的稀土配分型式极为相似。侵入岩的成因类型为A-型,形成于伸展构造环境。  相似文献   
152.
上推流厌氧反应器连续干发酵猪粪产沼气试验研究   总被引:9,自引:0,他引:9  
陈闯  邓良伟  信欣  郑丹  刘刈  孔垂雪 《环境科学》2012,33(3):1033-1040
为解决猪粪连续干发酵存在的氨抑制和出料难等难题,在温度(25±2)℃、有机负荷为干物质(TS)4.44 g.(L.d)-1的条件下,采用上推流式厌氧反应器(UPAR)对猪粪进行连续干式发酵试验,研究了猪粪干发酵过程的产气情况、氨抑制现象和出料流动性,并考察了上推流厌氧反应器进行猪粪干发酵的可行性.试验采用4种不同TS质量分数(20%、25%、30%、35%)的猪粪作为原料,经160 d的运行.结果表明,进料TS质量分数对发酵过程有很大的影响,4种不同进料TS质量分数稳定的池容产气率分别为2.40、1.73、0.89、0.62 L.(L.d)-1,进料TS质量分数为20%、25%和30%的产气效率明显优于进料TS=35%的产气效率.随着进料TS质量分数从20%增加到35%,氨氮质量浓度>2 300 mg.L-1会出现明显的产气抑制.在进料TS=35%时,氨氮质量浓度能达到3 800 mg.L-1,产气速率相对于进料TS=20%递减74.1%.当进料TS达到35%、出料TS质量分数达到17.1%、流速<0.002 m.s-1时,UPAR不能顺利出料.  相似文献   
153.
The post‐earthquake psychopathological investigation (PEPSI) was designed to probe the short‐and long‐term effects of the earthquake in northern Armenia on 7 December 1988 on survivors' mental and physical health. Four phases of this study have been conducted to date, and, overall, more than 80 per cent of a sub‐sample of 1,773 drawn from an initial cohort of 32,743 was successfully followed during 2012. This paper describes the methodology employed in the evaluation, summarises previous findings, details the current objectives, and examines the general characteristics of the sample based on the most recent follow‐up phase outcomes. Despite a significant decrease in psychopathology rates between 1990 and 2012, prevalence rates of post‐traumatic stress disorder and depression among study participants in 2012 were greater than 15 and 26 per cent, respectively. The paper also notes the strengths and limitations of the study vis‐à‐vis future research and highlights the importance and potential practical implications of similar assessments and their outcomes.  相似文献   
154.
Abstract: The International Union for Conservation of Nature (IUCN) Red List of Threatened Species was increasingly used during the 1980s to assess the conservation status of species for policy and planning purposes. This use stimulated the development of a new set of quantitative criteria for listing species in the categories of threat: critically endangered, endangered, and vulnerable. These criteria, which were intended to be applicable to all species except microorganisms, were part of a broader system for classifying threatened species and were fully implemented by IUCN in 2000. The system and the criteria have been widely used by conservation practitioners and scientists and now underpin one indicator being used to assess the Convention on Biological Diversity 2010 biodiversity target. We describe the process and the technical background to the IUCN Red List system. The criteria refer to fundamental biological processes underlying population decline and extinction. But given major differences between species, the threatening processes affecting them, and the paucity of knowledge relating to most species, the IUCN system had to be both broad and flexible to be applicable to the majority of described species. The system was designed to measure the symptoms of extinction risk, and uses 5 independent criteria relating to aspects of population loss and decline of range size. A species is assigned to a threat category if it meets the quantitative threshold for at least one criterion. The criteria and the accompanying rules and guidelines used by IUCN are intended to increase the consistency, transparency, and validity of its categorization system, but it necessitates some compromises that affect the applicability of the system and the species lists that result. In particular, choices were made over the assessment of uncertainty, poorly known species, depleted species, population decline, restricted ranges, and rarity; all of these affect the way red lists should be viewed and used. Processes related to priority setting and the development of national red lists need to take account of some assumptions in the formulation of the criteria.  相似文献   
155.
在土壤环境质量监测点位布设工作中,利用高分辨率遥感影像等数据和资料,可以增强点位布设结果的规范性和合理性。基于环境保护部和中国环境监测总站下发的土壤环境质量监测点位布设技术方案,分别介绍了基础点位、风险点位和背景点位的总体布设方式和布设要求,以及高分辨率遥感影像在各类点位理论布设中的具体应用方法。  相似文献   
156.
磷钼蓝法测定水中总磷,所用的抗坏血酸溶液很不稳定,只能保存数周。为延长抗坏血酸溶液的有效使用时间,节约试剂、提高工作效率,提出改进抗坏血酸溶液的配制方法,即在配制抗坏血酸溶液时,加入适量的EDTA和冰乙酸。经实验,该溶液贮于棕色玻璃瓶,放在冰箱中可稳定3个月,使用效果符合测定要求。  相似文献   
157.
统计了2014年以来江苏省国控企业不达标情况。从企业和环境保护部门两方面对国控企业不达标原因进行了分析。指出,企业应承担起污染治理的主体责任,健全企业环境保护制度;加强污染治理技术的研发及提高运维管理队伍的专业化水平,以适应新环保法的要求;环境监管部门强化执法宣传及违法行为的查处力度,让企业主动守法;加强国控企业环境信息的公开及宣传力度,形成良好的社会公众监督氛围;省级人民政府应积极落实国家生态文明建设的总规划,开启新的里程碑。  相似文献   
158.
结合我国污染场地的普遍特征以及场地初步调查的基本目标,从布点前期准备、布点原则、布点程序和布点方法等方面详细探讨了污染场地土壤初步调查的点位布设方法;并从采样准备、采集方法、采集程序以及现场记录等环节探讨了现场样品采集的注意事项和要求,以期为污染场地环境调查的土壤监测和采样提供借鉴。  相似文献   
159.
Abstract:  We identified 100 scientific questions that, if answered, would have the greatest impact on conservation practice and policy. Representatives from 21 international organizations, regional sections and working groups of the Society for Conservation Biology, and 12 academics, from all continents except Antarctica, compiled 2291 questions of relevance to conservation of biological diversity worldwide. The questions were gathered from 761 individuals through workshops, email requests, and discussions. Voting by email to short-list questions, followed by a 2-day workshop, was used to derive the final list of 100 questions. Most of the final questions were derived through a process of modification and combination as the workshop progressed. The questions are divided into 12 sections: ecosystem functions and services, climate change, technological change, protected areas, ecosystem management and restoration, terrestrial ecosystems, marine ecosystems, freshwater ecosystems, species management, organizational systems and processes, societal context and change, and impacts of conservation interventions. We anticipate that these questions will help identify new directions for researchers and assist funders in directing funds.  相似文献   
160.
渗灌——设施园艺先进的节水灌溉技术   总被引:19,自引:0,他引:19  
渗灌具有降低室内湿度、改善土壤环境、节约灌溉用水、减少肥料用量、省工省时、价格适中等优点,是目前设施园艺先进的节水灌溉技术。详细介绍了渗灌系统的结构,渗灌管的种类以及使用维护方法。  相似文献   
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