全文获取类型
收费全文 | 196篇 |
免费 | 17篇 |
国内免费 | 32篇 |
专业分类
安全科学 | 32篇 |
废物处理 | 7篇 |
环保管理 | 38篇 |
综合类 | 105篇 |
基础理论 | 20篇 |
污染及防治 | 12篇 |
评价与监测 | 19篇 |
社会与环境 | 8篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 11篇 |
2014年 | 6篇 |
2013年 | 14篇 |
2012年 | 16篇 |
2011年 | 15篇 |
2010年 | 14篇 |
2009年 | 12篇 |
2008年 | 9篇 |
2007年 | 19篇 |
2006年 | 11篇 |
2005年 | 10篇 |
2004年 | 16篇 |
2003年 | 10篇 |
2002年 | 9篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有245条查询结果,搜索用时 15 毫秒
151.
152.
153.
154.
Organophosphate esters (OPEs), used as flame retardants and plasticizers, are widely present in environmental waters. Development of accurate determination methods for trace OPEs in water is urgent for understanding the fate and risk of this class of emerging pollutants. However, the wide use of OPEs in experimental materials results in blank interference, which influences the accuracy of analytical results. In the present work, blank contamination and recovery of pretreatment procedures for analysis of OPEs in water samples were systematically examined for the first time. Blank contaminations were observed in filtration membranes, glass bottles, solid phase extraction cartridges, and nitrogen blowing instruments. These contaminations could be as high as 6.4–64 ng/L per treatment. Different kinds of membranes were compared in terms of contamination levels left after common glassware cleaning, and a special wash procedure was proposed to eliminate the contamination from membranes. Meanwhile, adsorption of highly hydrophobic OPEs on the inside wall of glass bottles was found to be 42.4%–86.1%, which was the primary cause of low recoveries and was significantly reduced by an additional washing step with acetonitrile. This work is expected to provide guidelines for the establishment of analysis methods for OPEs in aqueous samples. 相似文献
155.
我国新的地震区划编图和中国地震烈度区划图(1990) 总被引:10,自引:1,他引:10
本文阐述了我国新的地震区划工作的科学思路和技术方法,探讨了若干重要专门术语的涵义,讨论了某些环节的处理所蕴含的假定,最后,介绍了新的地震烈度区划图的概貌. 相似文献
156.
新中国成立后,效法前苏联的中国物权立法是一种按照所有权主体分类调整的“身份型”立法,该立法模式不仅抹杀了不同类型国有财产的“个性”,而且也将自然资源的公共性和生态性消融于普通财产的财产属性和独占使用之中。鉴于“公产法定,私产推定”立法模式能够实现自然资源领域政治国家与市民社会之间的利益平衡,并且“公产法定”具有限制国家公权、保障公众对特定自然资源的平等利用权等制度功能,应以国有自然资源资产的分类管理为逻辑主线,重构自然资源国家所有权客体制度:一是明确自然资源为不动产的物权法地位,借助自然资源不动产登记单元和“复杂物”概念对具有特定生态功能的同一自然资源登记单元的不同自然资源的整合功能,将其纳入传统民法物权客体理论的调整之中。二是依据不同自然资源社会属性之强弱,将国有自然资源资产区分为公产和私产,建立分类调整的规则体系,防范公产之上的国家所有权“遁入私法”。三是物权立法应直接明确国有自然资源资产受公法和私法的双重调整,可以公法和私法相互配合的方式行使所有权。四是国家和集体所有之外的资源原则上可自由利用。 相似文献
157.
Abstract Floating population is a special population group in China resulting from the implementation of household registration system. This paper uses a set of floating population survey data, population censuses data and statistical data to analyze the increase and influence of floating population on the urban population situations in Beijing. It is found that Beijing has experienced a rapid increase of floating population since the 1990s and that the increase of this group has become the key factor of the current population expansion in the city. Its distribution in the urban regions intensified and extended the suburbanization process of the capital. In addition, the population structures of sex, age, education and employment in Beijing have changed to some extent due to the influx of floating population. 相似文献
158.
目前国内外危险与可操作(HAZOP)分析方法主要用于工艺过程风险分析,而很多伤害事故是由于人员操作过程出现偏差引起的,采用头脑风暴式的HAZOP分析可对操作规程安全性进行系统全面的系统化的审查.结合实例对比分析了操作规程HAZOP分析与工艺过程HAZOP分析的差异,对操作步骤与引导词的关系、分析成员差别、操作规程HAZOP分析风险等级确定和分析重心等问题等进行了研究分析. 相似文献
159.
Detlef Mewes Fritz Mauser 《International journal of occupational safety and ergonomics》2013,19(2):177-191
Limitation of forces can be a simple measure to safeguard crushing points at doors, machines, and vehicles. In this connection different standards define a threshold force value of 150 N. This widely accepted value refers to static forces only. The dynamic forces that arise from impact on a person are frequently ignored, although they are generally higher than the static forces.The article describes an instrument for the measurement of static and dynamic crushing forces. This instrument has a stiffness that approximates the average stiffness of human fingers as one of the most at-risk parts of the human body with regard to crushing injuries. Sensory tests were carried out to define dynamic forces considered admissible at crushing points. 相似文献
160.
Munro LT 《Disasters》2002,26(3):242-261
In 1992-3 and 1995-6, Zimbabwe used a Child Supplementary Feeding Programme (CSFP) to combat child malnutrition during drought-induced emergencies. Previous evaluations of the CSFP relied on routine administrative data and key informant interviews and made only cursory use of available household survey data. These evaluations concluded that the CSFP was effective in preventing an increase in malnutrition among children under five, especially in 1992-3. The more-detailed analysis of household surveys provided in this article suggests that CSFP coverage was generally patchy and disappointingly low, especially in 1995-6. There is little evidence that children from poor or nutritionally vulnerable households got preferential access to supplementary feeding. The CSFP failed to feed many malnourished and nutritionally vulnerable children even in areas where the programme was operating. Household survey evidence suggests that the CSFP's impact on nutritional status was likely marginal, especially in 1995-6. 相似文献