全文获取类型
收费全文 | 2801篇 |
免费 | 182篇 |
国内免费 | 1226篇 |
专业分类
安全科学 | 216篇 |
废物处理 | 149篇 |
环保管理 | 201篇 |
综合类 | 1824篇 |
基础理论 | 486篇 |
污染及防治 | 988篇 |
评价与监测 | 142篇 |
社会与环境 | 97篇 |
灾害及防治 | 106篇 |
出版年
2024年 | 6篇 |
2023年 | 59篇 |
2022年 | 155篇 |
2021年 | 125篇 |
2020年 | 113篇 |
2019年 | 100篇 |
2018年 | 123篇 |
2017年 | 133篇 |
2016年 | 147篇 |
2015年 | 165篇 |
2014年 | 234篇 |
2013年 | 303篇 |
2012年 | 259篇 |
2011年 | 241篇 |
2010年 | 189篇 |
2009年 | 202篇 |
2008年 | 217篇 |
2007年 | 209篇 |
2006年 | 169篇 |
2005年 | 133篇 |
2004年 | 99篇 |
2003年 | 105篇 |
2002年 | 81篇 |
2001年 | 94篇 |
2000年 | 77篇 |
1999年 | 87篇 |
1998年 | 68篇 |
1997年 | 45篇 |
1996年 | 44篇 |
1995年 | 64篇 |
1994年 | 41篇 |
1993年 | 35篇 |
1992年 | 25篇 |
1991年 | 20篇 |
1990年 | 9篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1976年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有4209条查询结果,搜索用时 340 毫秒
351.
To study respiratory health effects of long-term exposure to ambient air pollutant mixture, we observed 7058 school children 5-16 years of age living in the four Chinese cities of Lanzhou, Chongqing, Wuhan, and Guangzhou. These children were enrolled from elementary schools located in eight districts, one urban district and one suburban district in each of the above cities. Ambient levels of PM(2.5), PM(10-2.5), total suspended particles (TSP), SO(2), and NO(x) were measured in these districts from 1993 to 1996. Based on a cluster analysis of arithmetic mean concentrations of PM(2.5), PM(10-2.5), (TSP-PM(10)), SO(2), and NO(x), we classified these children into four ordinal categories of exposure to ambient air pollutant mixtures. We tested for exposure-response relationships using logistic regression models, controlling for relevant covariates. We observed monotonic, positive relationships of exposure to the pollutant mixture with prevalence rates of cough with phlegm and wheeze. Other outcomes were not associated with the exposure in a monotonic exposure-response pattern. Even so, odds ratios for cough, phlegm, bronchitis, and asthma in the higher exposure district clusters were all higher than in the lowest exposure district cluster. We found evidence that exposure to the pollutant mixtures had adverse effects on children living in the four Chinese cities. 相似文献
352.
中海石油企业安全文化建设 总被引:2,自引:1,他引:1
企业安全文化建设既是中海石油自身持续、稳定发展的客观需要 ,也是新形势下企业内、外部环境变化的客观要求。通过不断完善企业安全文化系统工程及其管理体系 ,将安全生产工作提高到文化的高度去认识 ,依靠安全文化的潜移默化作用 ,提高全体员工的安全意识和整体安全文化素质 ,让“我要安全”、“我会安全”贯穿于生产经营活动的所有时空、每一个环节 ,树立“以人为本的绿色能源生产企业”的良好社会形象 ,大力推广“本质安全化”理念 ,增强企业的抗风险能力和竞争能力 相似文献
353.
介绍一种新型的SDSL(对称性数字用户环路)数据传输技术,该技术采用对称数字用户线点对点宽带传输数字信号,在利用一对电话线进行双向对称数字信号传输时,最大传输速率可达到1.5Mb/s。应用SDSL传输技术研制出煤矿多媒体救灾系统,详细阐述煤矿多媒体救灾系统的构成、功能及特点等,该系统能够实现井下灾区多媒体信息的实时传输,解决在矿山救灾的特殊环境条件下实现灾区图像\语音实时传输到井下救援基地、地面指挥中心及国家矿山救援指挥中心的难题。 相似文献
354.
Industrial complexes may release dust emissions through several to up to tens of stacks, as well as via fugitive area sources. Several diffusion models for small-scale fugitive dust sources have been developed and combined with a point source model to form a series of models for industrial complexes. The applicable area of these models and the methods for obtaining the main parameters in the models have been tested and verified using measurement data gained from several field experiments. The models developed in this paper can give quite satisfactory results when compared to other current models. 相似文献
355.
356.
357.
In this study, the content and speciation of arsenic in coal waste and gas condensates from coal waste fires were investigated,
respectively, using the digestion and sequential extraction methods. The fresh and fired-coal waste samples were collected
from Yangquan, which is one of the major coal production regions in northern China. High-performance liquid chromatography-inductively
coupled plasma-mass spectrometry (HPLC-ICP-MS) was used to determine the concentrations of four major arsenic species [As(III),
As(V), monomethylarsonic acid (MMA) and dimethylarsenic acid (DMA)] in the extracts, while ICP-MS was used to measure total
As content. Arsenic content in the investigated coal wastes and the condensate ranges between 23.3 and 69.3 mg/kg, which are
higher than its reported average content in soils. Arsenic in coal waste exists primarily in the residual fraction; this is
followed in decreasing order by the organic matter-bound, Fe–Mn oxides-bound, exchangeable, carbonates-bound, and water-soluble
fractions. The high content of arsenic in the condensates indicates that combustion or spontaneous combustion is one of the
major ways for arsenic release into the environment from coal waste. About 15% of the arsenic in the condensate sample is
labile and can release into the environment under leaching processes. The water extractable arsenic (WEA) in the fresh coal
waste, fired coal wastes, and the condensate varied between 14.6 and 341 μg/kg, with As(V) as the major species. Furthermore,
both MMA and DMA were found in fresh coal wastes, fired coal wastes, and the condensate. 相似文献
358.
359.
Cai Kui Du Juan Dai Cong Hu Huabin . Center for Rural Development Studies Yunnan University Kunming Yunnan China . Institute of Ethnology Yunnan Academy of Social Science Kunming Yunnan China . Institute of Economics Yunnan Academy of Social Science Kunming Yunnan China . Xishuangbanna Tropical Botany Garden Chinese Academy of Sciences Kunming Yunan China 《中国人口.资源与环境(英文版)》2007,5(2):78-83
A three-year study over the Bai, Jingpo and Huayaodai communities in Yunnan Province reveals that the community development is significantly influenced in various ways by such cultural factors as the concepts of development; concepts and traditions of inter-community relationships, consumption, mar- riage and gender; patterns of decision-making and production, resource and income allocation; as well as the role of information dissemination systems, religion and ritual. Based on the analysis over the interactive relevance between each factor and community development, some strategies and methods for dealing with such a cultural relevance in development projects are recommended. 相似文献
360.
针对武钢7~#焦炉存在的污染问题,进行了治理改造,采用热浮力罩除尘车,使集尘、除尘、生产于一体,运行后使除尘系统烟气净化效率得到提高,各种污染物都得到了降低。 相似文献