全文获取类型
收费全文 | 138篇 |
免费 | 11篇 |
国内免费 | 42篇 |
专业分类
安全科学 | 11篇 |
废物处理 | 3篇 |
环保管理 | 16篇 |
综合类 | 72篇 |
基础理论 | 15篇 |
污染及防治 | 40篇 |
评价与监测 | 11篇 |
社会与环境 | 13篇 |
灾害及防治 | 10篇 |
出版年
2023年 | 3篇 |
2022年 | 1篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 6篇 |
2017年 | 4篇 |
2016年 | 8篇 |
2015年 | 9篇 |
2014年 | 13篇 |
2013年 | 13篇 |
2012年 | 11篇 |
2011年 | 11篇 |
2010年 | 10篇 |
2009年 | 9篇 |
2008年 | 8篇 |
2007年 | 8篇 |
2006年 | 5篇 |
2005年 | 3篇 |
2004年 | 5篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1994年 | 5篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1982年 | 2篇 |
1981年 | 1篇 |
排序方式: 共有191条查询结果,搜索用时 437 毫秒
121.
大气细菌粒子与飘尘粒子的关系 总被引:3,自引:0,他引:3
本研究用ANDERSEN生物粒子采样器和光散射气溶胶粒子计数器,在北京西单和丰台对大气细菌粒子与飘尘粒子的浓度和浓度分布及两者之间的关系进行了观测。结果表明,大气细菌粒子的日平均浓度为2.882个/l,浓度分布是从第6级至第1级逐级增大;飘尘粒子的平均浓度为149464个/l,浓度分布是从0.5~32μm依次减小:大气细菌粒子浓度与≥2.0μm的飘尘粒子有非常明显的正相关关系。 相似文献
122.
123.
124.
125.
126.
127.
Nini Pang Jian Gao Fei Che Tong M Su Liu Yan Yang Pusheng Zhao Jie Yuan Jiayuan Liu Zhongjun Xu Fahe Chai 《环境科学学报(英文版)》2020,32(9):201-209
To investigate the cause of fine particulate matter (particles with an aerodynamic diameter less than 2.5 µm, PM2.5) pollution in the heating season in the North China Plain (specifically Beijing, Tianjin, and Langfang), water-soluble ions and carbonaceous components in PM2.5 were simultaneously measured by online instruments with 1-hr resolution, from November 15, 2016 to March 15, 2017. The results showed extreme severity of PM2.5 pollution on a regional scale. Secondary inorganic ions (SNA, i.e., NO3?+SO42+ NH4+) dominated the water-soluble ions, accounting for 30%-40% of PM2.5, while the total carbon (TC, i.e., OC + EC) contributed to 26.5%-30.1% of PM2.5 in the three cities. SNA were mainly responsible for the increasing PM2.5 pollution compared with organic matter (OM). NO3? was the most abundant species among water-soluble ions, but SO42- played a much more important role in driving the elevated PM2.5 concentrations. The relative humidity (RH) and its precursor SO2 were the key factors affecting the formation of sulfate. Homogeneous reactions dominated the formation of nitrate which was mainly limited by HNO3 in ammonia-rich conditions. Secondary formation and regional transport from the heavily polluted region promoted the growth of PM2.5 concentrations in the formation stage of PM2.5 pollution in Beijing and Langfang. Regional transport or local emissions, along with secondary formation, made great contributions to the PM2.5 pollution in the evolution stage of PM2.5 pollution in Beijing and Langfang. The favourable meteorological conditions and regional transport from a relatively clean region both favored the diffusion of pollutants in all three cities. 相似文献
128.
电厂输煤系统配置静电和布袋除尘设备的比较分析 总被引:1,自引:0,他引:1
文章分析了电厂输煤系统产生粉尘污染的原因及其特性,提出了选择配置除尘器的基本原则,是在保证“两头不冒尘”的前提下,做到“室内外达标”。对输煤系统常用的布袋、静电两种除尘配置方式以及设备布置方式进行了比较分析,建议应综合比较系统的初投资、运行费用以及运行率,即系统寿命期成本来选择除尘设备,着重考虑选择长期运行维护工作量低和运行费用低的设备。建议优先采用尘源就地控制以及“干式除尘一于尘回收”的方式,列举了2×300MW机组输煤系统配套布袋除尘器和电除尘器技术参数与经济指标比较表,得出采用静电除尘方式的综合性价比优于布袋除尘方式的结论。 相似文献
129.
Distribution of Chironomidae (Insecta: Diptera) in polluted rivers of the Juru
River Basin, Penang, Malaysia 总被引:1,自引:0,他引:1
Salman A. Al-Shami Che Salmah Md Rawi Abu HassanAhm Siti Azizah Mohd Nor 《环境科学学报(英文版)》2010,22(11):1718-1727
The influence of physical and chemical parameters on the abundance and diversity of chironomids was studied in six rivers with
moderate to highly polluted water in the Juru River Basin. The rivers: Ceruk Tok Kun (CTKR) as reference site, and polluted rivers
of Pasir (PR), Juru (JR), Permatang Rawa (PRR), Ara (AR) and Kilang Ubi (KUR) were sampled over a period of five months
(November 2007–March 2008). Nine chirnomid species: Chironimus kiiensis, C. javanus, Polypedilum trigonus, Microchironomus sp.,
Dicrotendipes sp., Tanytarsus formosanus, Clinotanypus sp., Tanypus punctipennis and Fittkauimyia sp. were identified. Assessment
of their relationships with several environmental parameters was performed using the canonical correspondence analysis (CCA).
Tanytarsus formosanus was the most dominant in the relatively clean CTKR and moderately polluted JR with mean densities of
19.66 and 25.32 m?2, respectively while C. kiiensis was abundant in more polluted rivers. Tanytarsus formosanus, Dicrotendipes sp.
and Microchironomus sp. were grouped under moderate to high water temperature, total organic matter (TOM), total suspended solids
(TSS), velocity, pH, phosphates and sulphates. However, Tanypus punctipennis, Fittkauimyia sp., and Clinotanypus sp. were associated
with high contents of river sediment such as TOM, Zn and Mn and water ammonium-N and nitrate-N and they were associated with
higher dissolved oxygen (DO) content in the water. Chironomus kiiensis, C. javanus and P. trigonus showed positive relationships with
TOM, ammonium-N and nitrate-N as well as trace metals of Zn, Cu and Mn. These three species could be considered as tolerant species
since they have the ability to survive in extreme environmental conditions with low DO and high concentrations of pollutants. Based on
the water parameter scores in all rivers, the highest diversity of chironomid larvae was reported in CTKR. With higher concentrations
of organic and/or inorganic pollutants as reported in PPR, KUR and AR, the chironomid larval diversity decreased, and the abundance
of tolerant species, mainly Chironomus spp., increased. 相似文献
130.
土地整理规划中的自然生态补偿评价方法探讨 总被引:5,自引:1,他引:4
土地整理对生态系统有正负两方而的影响,在规划设计过程中要增加生态补偿设计以减少负而影响.生态补偿的程度直接影响土地整理的让态效益,足衡量土地整理成功与否的一个重要指标.自然生态补偿评价是一个新的课题,其理论与方法体系均有待探讨.文章结合土地整理实践探讨了土地整理规划中的自然生态补偿评价的方法.该方法遵循科学性、系统性、实用性、定量性与可比性的原则,以递阶层次综合评价法为基础,从生态结构合理性、生态功能稳定性与生态环境适宜性3方面选掸17个指标量对土地整理规划中的自然生态补偿进行了评价.结合土地整理实践确定了指标权重与分级标准,并将生态补偿效果分为5个基本等级.该研究建市的生态补偿评价指标体系力求综合反映土地整理规划中的生态对自然生态系统的系统的稳定与可持续性、系统的生产力、生态环境的改善及系统抵御自然灾害能力的贡献. 相似文献