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941.
Six air issues are currently on science and policy agendas in Canadaand elsewhere. These are climate change, stratospheric ozone depletion(increased UV-B radiation), acidic deposition, SMOG (increasedground-level ozone), suspended particulate matter, and hazardous airpollutants. Atmospheric scientists and decision makers have largelyaddressed these issues individually resulting in single-issue policies. However, it is now recognized that these issues are inter-related, andthey may interact to cause negative as well as some beneficial effects,not only on the state of the atmosphere but also on societal andecological systems. This paper illustrates through several examples theatmospheric dysfunction caused by the linkages among the six airissues. It also points to potentially conflicting policies arising from thesingle-issue approach, and it emphasizes the need for better integrationof air issues. The linkages are summarized qualitatively in Table I. 相似文献
942.
Little EE Calfee RD Fabacher DL Carey C Blazer VS Middleton EM 《Environmental science and pollution research international》2003,10(3):167-172
Background Exposure to harmful levels of ultraviolet-B radiation (UVB), a component of solar radiation, has been suggested as a potential
cause of amphibian declines.
Methods We measured solar radiation (UVB, ultraviolet-A, and visible) wavebands in breeding ponds of Bufo boreas (boreal toad, a montane species that has undergone severe population declines) and Bufo woodhousii (Woodhouse’s toad, a plains toad that has not experienced declines) and examined tolerances of these species to simulated
solar UVB exposures in the laboratory.
Results We found larvae of both species to be tolerant of simulated solar UVB in excess of solar UVB levels observed in their breeding
ponds. B. boreas tadpoles were more tolerant of simulated solar UVB exposure than B. woodhousii tadpoles, possibly because of greater amounts of photoprotective melanin in B. boreas skin.
Conclusions UVB levels observed in B. boreas habitats do not currently appear to constitute a threat to the survival of these animals; however, long-term (>1 month) exposure
to UVB levels comparable to levels associated with the water interface appears to reduce survival in B. woodhousii tadpoles. Therefore, future increases in surface and water column UVB radiation in bufonid habitats might pose significant
survival risks to B. boreas or B. woodhousii populations. 相似文献
943.
944.
945.
家用电器工频电磁辐射水平分析 总被引:2,自引:0,他引:2
对电磁波的产生机理以及对人体的危害进行了分析阐述,对人们日常生活中的家用电器电磁辐射水平进行了调查测量,分析了不同家用电器的电磁辐射水平,并有针对性提出了一些科学有效的防护措施。 相似文献
946.
947.
电子设备的电磁兼容性设计 总被引:1,自引:0,他引:1
电磁兼容性在电子设备中占有重要的地位,电磁干扰直接影响到电子设备能否正常、可靠的工作.为了提高电子设备的工作稳定性,必须解决电子设备在电磁环境中的适应能力,对电子设备进行电磁兼容性设计. 相似文献
948.
重庆雾的声雷达回波与大气SO2浓度的对比分析 总被引:1,自引:0,他引:1
本文分析了重庆1989年12月30日雾的声雷达回波特征与浓雾天气的关系,讨论了雾日大气SO2地面浓度状况。结果表明,声雷达回波与雾的定变有较好的对应;地面污染物浓度与声雷达回波所反应的大气层结状况关系密切,300-400米高度上的逆温层维持较长时间是加重当日大气SO2地面浓度的重要原因。 相似文献
949.
Samara Teixeira Pereira Elisngela Maria Rodrigues Rocha Elson Santos da Silva Giulia Beatriz Mota da Silva Maria Luisa Palitot Remigio Alves 《环境质量管理》2020,29(3):43-49
The present work investigated color and biochemical oxygen demand (COD) removal from treated landfill leachate via advanced oxidative processes (AOPs) artificially emitted. The AOP H2O2/UV, TiO2/UV, and photolysis were tested in two bench‐scale photoreactors: The first one with UV‐C lamp and the other with UV‐A lamp associated or not with coagulation / flocculation pretreatment. Crude leachate samples with pH ranging from 8 to 3 were used, and time varied in 30, 45, and 60 minutes. Experiments were performed in two stages: step 1 with a 20 mL volume from each sample and step 2 with repetition of the best results from the previous step, adopting the 150 mL volume. In step 1, the AOP applied in the crude leachate sample showed the best results, standing out H2O2/UV‐C with 30 minutes and TiO2/UV‐A with 60 minutes. In step 2, H2O2/UV‐C had a 60% color removal and 25% COD reduction, while TiO2/UV‐A had a 10% color removal and 20% COD reduction. Therefore, the H2O2/UV‐C process was the most efficient, because the complex characteristics of the effluent interfered in the TiO2/UV‐A efficiency, but it is necessary to eliminate the process interferences. The use of artificial radiation is a viable alternative; however, it can be costly, being relevant in the associations between processes with artificial UV and solar UV, as the natural radiation becomes more attractive and allows the process operating costs reduction. 相似文献
950.
通过对 6个震例的分析研究 ,总结出电磁辐射源来自陆域空间和海域空间的规律 ;震前电磁异常的识别及非震异常的特征与排除 ,并成功地进行了一次临震预报。 相似文献