全文获取类型
收费全文 | 2626篇 |
免费 | 170篇 |
国内免费 | 494篇 |
专业分类
安全科学 | 329篇 |
废物处理 | 46篇 |
环保管理 | 278篇 |
综合类 | 1402篇 |
基础理论 | 407篇 |
环境理论 | 1篇 |
污染及防治 | 249篇 |
评价与监测 | 130篇 |
社会与环境 | 226篇 |
灾害及防治 | 222篇 |
出版年
2024年 | 7篇 |
2023年 | 45篇 |
2022年 | 66篇 |
2021年 | 87篇 |
2020年 | 72篇 |
2019年 | 60篇 |
2018年 | 80篇 |
2017年 | 101篇 |
2016年 | 110篇 |
2015年 | 100篇 |
2014年 | 128篇 |
2013年 | 190篇 |
2012年 | 156篇 |
2011年 | 201篇 |
2010年 | 140篇 |
2009年 | 159篇 |
2008年 | 93篇 |
2007年 | 181篇 |
2006年 | 182篇 |
2005年 | 160篇 |
2004年 | 106篇 |
2003年 | 150篇 |
2002年 | 108篇 |
2001年 | 103篇 |
2000年 | 75篇 |
1999年 | 67篇 |
1998年 | 65篇 |
1997年 | 51篇 |
1996年 | 39篇 |
1995年 | 47篇 |
1994年 | 36篇 |
1993年 | 30篇 |
1992年 | 33篇 |
1991年 | 16篇 |
1990年 | 11篇 |
1989年 | 2篇 |
1988年 | 12篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有3290条查询结果,搜索用时 20 毫秒
931.
为提高高位裂隙钻孔抽采采空区瓦斯的效果,必须掌握采空区"三带"特征。在理论分析的基础上,现场考察黄陵2号煤矿107工作面冒落带分布,结果表明:冒落带呈拱形分布,并且沿采空区横向对称,最大冒落高度为19 m。通过Fluent数值模拟方法,得出采空区瓦斯抽采的最佳区域,验证了现场考察冒落带非等值高度的正确性。这表明,在分析采空区"三带"特征时,应考虑冒落高度的非等值性,进而通过理论分析、现场考察、数值模拟等手段得出采空区抽采的最佳区域。 相似文献
932.
Zhang Juntao & Li Jin School of Public Administration Dongbei University of Finance Economics Dalian China 《中国人口.资源与环境(英文版)》2004,2(3)
The vulnerable eco-area is one of the important research targets in the field of sustainable development. It is the requirement of building a well-off society in an all-round way that we should study more on the vulnerable eco-areas, deal with the relationship between environmental protection and economic development, speed up the economic development in these areas and increase the living standard of the local people. This paper puts forward the countermeasures of environment---economy coordination, on the basis of the recognition of eco-environment features and social economic conditions in the vulnerable eco-areas of China, in view of the progress in sustainable development studies of the vulnerable ones, taking the transitional areas of farming and pasturing in northeast China as an example to study the regional environment vulnerability. 相似文献
933.
Ye Hanxiong Wu Xiangling School of Political Science Public Management Wuhan University Wuhan Hubei China 《中国人口.资源与环境(英文版)》2007,5(2):84-87
Nowadays, the disparity of the basic pension in local regions of China can be described as follows: the low level of the unification of the basic pension systems, the large disparity of the level of the basic pension, and unfairness of the enterprises’ payment for the basic pension in different local regions in China. These have already brought many negative influences, which have greatly held back the development of the society and national economy. We should build the basic pension system in all local regions of China as a whole, which can cover all people and decrease the disparity in different local regions in China. 相似文献
934.
935.
通过对昌吉州三工镇和榆树沟镇、米泉市古牧地镇和柏杨河乡种植区土壤、空气质量、灌溉水的监测分析与调查研究,对比清洁区蔬菜基地与污灌区蔬菜基地环境现状,探讨了灌溉用水对蔬菜质量的影响,提出切实可行的防治措施. 相似文献
936.
/ The Itapiranga Sustainable Logging Plan provides an example of how Brazil's licensing system functions for logging companies in the state of Amazonas. Two questions need to be dealt with: "How sustainable can logging in the Amazon be?" and "What and how effective are existing legal mechanisms to deal with logging projects?" The environmental impact assessment (EIA) and environmental impact statement (EIS, known as the RIMA in Brazil), present relatively detailed accounts of biodiversity and the need to adopt conservation strategies to protect it. However, social and health impacts are only superficially addressed. The economic sustainability of the operation over multiple cycles is not demonstrated. The multidisciplinary teams responsible for the EIA and EIS (RIMA) reports are hired by the project proponent, an arrangement inherently carrying the risk of biasing the result. Logging reduces biodiversity, releases greenhouse gases and inflicts social and health costs. These impacts reduce the ability of Amazonian forests to provide environmental services and to supply food and livelihood security to local populations. The reports inflate positive effects such as employment: the estimated number of jobs was cut by more than half in a revision made after the EIA and EIS (RIMA) had been approved. Not only do the reports need to be more realistic in assessing both positive and negative consequences of proposed projects, but better means are needed to ensure that promised mitigatory measures are enforced in practice. Many of the lessons that can be drawn from the Itapiranga Plan are not unique to logging projects and apply to licensing of development activites generally in Brazil and elsewhere. 相似文献
937.
While basic guidelines on HIV prevention in emergencies have been available for several years, international agencies involved in the provision of health services have not placed sufficient priority on the prevention of the human immune deficiency virus (HIV) and other sexually transmitted infections (STIs) in complex emergencies. This paper reviews the factors that may increase the risk of HIV transmission in populations affected by complex emergencies and outlines recommendations for research and programmes. Research into the most appropriate methods of carrying out HIV surveillance and interventions in these settings is needed. In the post-emergency phase programmes need to be far more extensive than those offered under the Minimal Initial Services Package (MISP). While the potential for stigmatization represents an important constraint, there is a need to prioritize HIV/STI interventions in order to prevent HIV transmission in emergency-affected populations themselves, as well as to contribute to regional control of the epidemic. 相似文献
938.
中国火灾最佳灰色回归组合预测模型 总被引:4,自引:6,他引:4
火灾现象具有随机性、模糊性,是个复杂的灰色系统行为。研究火灾发生的规律及发展趋势,具有实用价值。笔者给出最小二乘估计意义下的最佳组合预测模型的定义,并求得其权的公式和证明权的惟一性;用回归分析方法建立多个回归模型,并按3条标准即①回归指数大、②系统误差小、③模型精度高,选定最佳非线性回归模型;用灰色理论建立多个灰色模型,并按3条标准即①后验差比值小、②小误差概率大、③预测关联度大,选定最佳灰色模型;再将最佳回归模型与最佳灰色模型有机地结合起来建立中国火灾最佳灰色回归组合预测模型。组合预测模型综合利用前两者提供的不同的有用信息,改善了单一模型的局限性,提高了预测精度,减少了预测误差。组合模型预测中国年火灾起数处于动态增长过程。 相似文献
939.
基于人的认知可靠性(HCR)模型的人因操作失误研究 总被引:7,自引:4,他引:7
以人的认知可靠性(HCR)模型为指导,选择包含技能型、规则型和知识型3种认知类型,结合大连化工集团公司影响运行安全的17个异常事件,对54名操纵员的时间响应状况和允许操作时间进行录像、记录与分析;依据IAEA提供的指标[1],找出操纵员在生产过程中可能出现的操作失误类别及其可能造成的危害;基于3参数威布尔模型推导出操纵员操作响应失误概率模型,并从人机工程学角度提出了具体预防事故的安全对策措施。结果表明,基于HCR模型的大化集团公司操纵员的人因操作失误模型实用、有效,为实现操作者与机器系统相协调的目标、正确评估操作着实时操作的响应时间提供了重要参考依据。 相似文献
940.
企业员工安全文化素质的层次分析 总被引:1,自引:1,他引:1
建设良好的企业安全文化可以预防企业的事故发生,而企业员工安全文化素质则是企业安全文化的根基,也是企业安全文化的具体体现。通过建立员工安全文化层次渐近模型,分析企业员工安全文化素质的5个层次,即安全的无意识、体制约束下的安全意识、自我的安全意识、自我的可控安全意识、超越自我的安全意识。从中得出,员工安全文化素质的培养是一个长期的渐进的过程,是相互协作的结果。员工安全意识的培养是企业安全文化的标志,它需要良好的氛围,并且体现了企业安全文化的核心本质。因此,培养员工安全文化意识对解决企业安全文化建设及保证企业安全运转具有十分重要的意义。 相似文献