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291.
石家庄市冬季大气中VOCs污染特征分析 总被引:5,自引:3,他引:2
为弄清石家庄市冬季大气中VOCs的污染特征,采用美国环保局TO-15方法对石家庄市冬季大气中VOCs组成进行了定性和定量分析。在此基础上,进行了VOCs的月度变化分析、春节期间的变化分析,并进行了VOCs与空气质量指数AQI、PM2.5等之间的相关性分析;根据VOCs组成及变化情况和相关性,分析了其可能的来源。结果表明,石家庄市冬季大气中VOCs的质量浓度为145.7~1 410.7μg/m3,VOCs组分主要有丙酮、二氯甲烷、苯、乙酸乙酯、甲苯、1,2-二氯丙烷、三氯甲烷。春节期间,大气中VOCs的浓度有大幅的下降,比日常均值下降了40.9%。AQI较高时,大气中VOCs浓度有所升高。石家庄市冬季大气中丙酮、二氯甲烷、乙酸乙酯等主要来源于医药化工生产活动,苯、甲苯主要来源于煤燃烧。 相似文献
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The present study evaluates the toxicity of 34 propargylic alcohols, including primary, primary homo-, secondary, and tertiary alcohols, based on their effects on phytoplankton. A closed-system algal toxicity test was applied because the closed-system technique presents more realistic concentration-response relationships for the above compounds than the conventional batch tests. The green alga, Pseudokirchneriella subcapitata, was the test organism and final yield and growth rate were chosen as the test endpoints. Among all the propargylic alcohols tested, 1-pentyn-3-ol is the most toxic compound with its EC50 equal to 0.50 mg L(-1), which can be classified as a "R50" compound (very toxic to aquatic organisms, EC50/LC50 < 1 mg L(-1)), following the current practice for classification of chemicals in the European Union (EU). There are several other compounds including 2-decyn-1-ol, 3-decyn-1-ol, 1-hexyn-3-ol, 3-butyn-2-ol, and 3-hexyne-2,5-diol, which deserve more attention for their possible adverse impact on the aquatic environment, because these alcohols can be classified as "R51" compounds (toxic to aquatic organisms, EC50/LC50 between 1 and 10 mg L(-1)). Compared to the base-line toxicity relationship (narcosis QSAR) derived previously, tertiary propargylic alcohols can be identified as nonpolar narcotic chemicals, while secondary alcohols and primary alcohols with low molecular weight generally exhibit obvious excess toxicity in relation to the base-line toxicity. Finally, quantitative structure-activity relationships were established for deriving a preliminary estimation of the toxicity of other propargylic alcohols. 相似文献
295.
珠江口表层水中多环芳烃的分布特征及健康风险评估 总被引:1,自引:0,他引:1
分别于2015年2、5、8、11月在珠江八大入海口采集表层水体样品,应用固相萃取富集法对该区域表层水体中16种USEPA优控多环芳烃(PAHs)的时空分布特征进行分析,并利用终生致癌风险增量模型(ILCR)对该区域的饮水健康风险进行评价。结果表明:珠江口4个季度所采集的水样中,∑15PAHs的浓度范围为18.0~50.3 ng/L,含量处于中等水平。其中7种强致癌性∑7PAHs的浓度范围为1.53~3.73 ng/L,占∑15PAHs的5.89%~11.1%,∑15PAHs和∑7PAHs在枯水期(2、11月)样品中明显高于丰水期(5、8月)。就组成特征而言,各采样点PAHs以3、4环为主。珠江口表层水中非致癌类PAHs的危害商数值为0.99×10~(-5)~2.73×10~(-5),远低于USEPA规定的阈值(1);致癌类PAHs产生的健康风险为6.50×10~(-8)~2.37×10~(-7),其中Ba P导致的饮水途径健康风险最高,所有点位致癌类PAHs的健康风险均低于USEPA推荐的对致癌物质最大可接受风险水平(10~(-6)),表明珠江口表层水中PAHs尚不具备严重的致癌风险,但是仍然存在潜在的健康风险,需要重点控制和管理。 相似文献
296.
Y. Chen H. R. Jia S. Niu X. Zhang H. L. Wang Y. Z. Ye Q. S. Chen Z. L. Yuan 《Russian Journal of Ecology》2018,49(1):40-46
Species turnover patterns can be inconsistent due to differences in the dispersal ability of different growth forms. Here, species of trees, shrubs, herbs, and bryophytes in the Xiaoqinling National Nature Reserve in China were analyzed to determine patterns of species turnover along an elevation and spatial gradient. Variance partitioning was used to assess the relative contribution of topographic heterogeneity and dispersal limitation to species turnover. Our results suggest that the effect of dispersal limitation is more important than topographic heterogeneity on species turnover in temperate mountane ecosystems in the study area. Dispersal limitation has a greater effect on trees species turnover than on shrubs, herbs or bryophytes species turnover. 相似文献
297.
Wenli Feng Zhiqiang Wu Liangliang Huang Yang Ding Ruidan Shi 《Russian Journal of Ecology》2018,49(3):260-267
To evaluate the effect of abiotic factors on larval and juvenile fish assemblage in shallow waters of middle reaches of Li River, Guilin, China. Samplings were taken monthly at 7 stations in the mainstream and 2 stations in 3 tributaries from May 2014 to April 2015. Synchronously, temperature, pH, turbidity, conductivity, dissolved oxygen rainfall and discharge were obtained. In all, 11.886 larval and juvenile fish from 18 species belonging to 8 families, 16 genera was captured. Principal Component Analysis (PCA) showed obvious significant difference between the environmental variables across sampling areas and months. The results of Canonical Correspondence Analysis (CCA) indicated that water temperature, turbidity, discharge and rainfall were dominant factors on larval and juvenile fish assemblage. 相似文献
298.
采用溶胶-凝胶法制备了Mn掺杂钙钛矿型催化剂LaFexMn1-xO3,并以其为催化剂催化湿式双氧水氧化处理煤气化废水纳滤浓缩液。采用XRD,SEM,FTIR技术对催化剂进行了表征。表征结果显示:制备的催化剂均具有标准的钙钛矿型结构,其中,LaFe0.9Mn0.1O3的结构稳定,比表面积大。实验结果表明:制备的催化剂中LaFe0.9Mn0.1O3的催化活性最高,且稳定性好,连续使用5次后催化活性未见明显减弱;在H2O2投加量3.0 g/L、n(H2O2)∶n(LaFe0.9Mn0.1O3)=12∶1、反应温度160 ℃、反应压力1 MPa、浓缩液pH 3、反应时间60 min的最优条件下,COD、UV254和TOC的去除率分别达到80.9%、95.2%和68.0%,BOD5/COD由0.02提升至0.40,可生化性大幅提高。 相似文献
299.
Wen-Jun Hong Hongliang Jia Yongsheng Ding Wen-Long Li Yi-Fan Li 《Journal of Material Cycles and Waste Management》2018,20(1):80-90
The present study investigated the occurrence of polychlorinated biphenyls (PCBs) and halogenated flame retardants (HFRs) in soil, water, reed, air and dust samples collected from the e-waste recycling region in Ziya Town, Northern China. The results showed that the concentrations of PCBs reached relative high level in environmental matrices in the study area. HFRs including polybrominated diphenyl ethers (PBDEs), dechlorane plus (DP), allyl 2,4,6-tribromophenyl ether (ATE), tetrabromoethylcyclohexane (TBECH), pentabromotoluene (PBT), pentabromoethylbenzene (PBEB), 2,3-dibromopropyl 2,4,6-tribromophenyl ether (DPTE), 1,2-bis-(2,4,6-tribromophenoxy) ethane (BTBPE) and so on were also widely detected in multi-matrices. Long-range atmospheric transport (LRAT) potentials of non-BDE HFRs were assessed to address the LRAR abilities of these compounds. Analysis of soil–air exchange of PCBs and HFRs showed that soil acted as a secondary source to the atmosphere only for a few low molecular weight compounds, while the direction of the flux of most detected chemicals was from air to soil. 相似文献
300.
生态文明制度体系是由制度构成的一个相互配合、有机联系的整体。本文基于文献统计分析与实地调研咨询,从广义和狭义层面,分别对生态文明制度进行梳理。根据国家生态文明建设需求与省级层面实际情况,本文将广义的生态文明制度体系分为源头保护制度体系、损害赔偿与激励体系、追责考评制度体系和污染治理制度体系四大板块,并针对国家与省级重点生态文明制度,构建生态资源保护制度链与污染防治制度链。同时,对制度地位、制度衔接、相互关系及其优化选择进行分析,以提高环境管理效能,推进生态文明研究纵深发展。 相似文献