首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1674篇
  免费   99篇
  国内免费   424篇
安全科学   116篇
废物处理   72篇
环保管理   157篇
综合类   945篇
基础理论   243篇
污染及防治   414篇
评价与监测   94篇
社会与环境   93篇
灾害及防治   63篇
  2024年   1篇
  2023年   20篇
  2022年   83篇
  2021年   80篇
  2020年   65篇
  2019年   70篇
  2018年   73篇
  2017年   86篇
  2016年   80篇
  2015年   98篇
  2014年   138篇
  2013年   171篇
  2012年   148篇
  2011年   152篇
  2010年   111篇
  2009年   105篇
  2008年   106篇
  2007年   106篇
  2006年   77篇
  2005年   56篇
  2004年   41篇
  2003年   58篇
  2002年   45篇
  2001年   53篇
  2000年   31篇
  1999年   28篇
  1998年   21篇
  1997年   23篇
  1996年   14篇
  1995年   11篇
  1994年   6篇
  1993年   10篇
  1992年   12篇
  1991年   10篇
  1990年   3篇
  1989年   1篇
  1988年   1篇
  1987年   2篇
  1982年   1篇
排序方式: 共有2197条查询结果,搜索用时 296 毫秒
991.
Environmental Science and Pollution Research - A green and-easy to operate method, the microwave technology, was developed to promote the desulfurization process of phosphate rock, systematically...  相似文献   
992.
• The Large scale Urban Consumption of energY model was updated and coupled with WRF. • Anthropogenic heat emissions altered the precipitation and its spatial distribution. • A reasonable AHE scheme could improve the performance of simulated PM2.5. • AHE aggravated the O3 pollution in urban areas. Anthropogenic heat emissions (AHE) play an important role in modulating the atmospheric thermodynamic and kinetic properties within the urban planetary boundary layer, particularly in densely populated megacities like Beijing. In this study, we estimate the AHE by using a Large-scale Urban Consumption of energY (LUCY) model and further couple LUCY with a high-resolution regional chemical transport model to evaluate the impact of AHE on atmospheric environment in Beijing. In areas with high AHE, the 2-m temperature (T2) increased to varying degrees and showed distinct diurnal and seasonal variations with maxima in night and winter. The increase in 10-m wind speed (WS10) and planetary boundary layer height (PBLH) exhibited slight diurnal variations but showed significant seasonal variations. Further, the systematic continuous precipitation increased by 2.1 mm due to the increase in PBLH and water vapor in upper air. In contrast, the precipitation in local thermal convective showers increased little because of the limited water vapor. Meanwhile, the PM2.5 reduced in areas with high AHE because of the increase in WS10 and PBLH and continued to reduce as the pollution levels increased. In contrast, in areas where prevailing wind direction was opposite to that of thermal circulation caused by AHE, the WS10 reduced, leading to increased PM2.5. The changes of PM2.5 illustrated that a reasonable AHE scheme might be an effective means to improve the performance of PM2.5 simulation. Besides, high AHE aggravated the O3 pollution in urban areas due to the reduction in NOx.  相似文献   
993.
Environmental Science and Pollution Research - Microplastics (MPs) and chemical pollutants usually coexist in aquatic environments. The bioaccumulation and metabolism of pollutants in aquatic...  相似文献   
994.
Environmental Science and Pollution Research - To comprehensively understand the toxic risks of phthalates to aquatic ecosystems, we examined the acute toxicity of di-(2-ethylhexyl) phthalate...  相似文献   
995.
利用单颗粒气溶胶质谱仪(SPAMS)于2018年1月1日—2019年12月31日对上海市浦东新区环境空气PM2.5开展高时间分辨化学成分监测。结果表明,2019年监测点空气质量总体优于2018年,AQI达标率由74.8%升高至86.6%。通过对PM2.5成分分类,最终确定了8类颗粒物,相较于2018年,2019年富钾颗粒物升幅较为明显,左旋葡聚糖、重金属和元素碳有小幅增加,其余各组分相对减少。对PM2.5排放源分类分析显示,机动车尾气源占比>25%,其中2018年3月、2018年7月、2019年2和3月贡献超过40%;二次无机源和燃煤源呈现一定的季节变化特点,整体秋冬季高于春夏季,2019年燃煤源占比较2018年下降了41%;工业排放源2018年5和10月、2019年1和5月占比相对较高,其余各月份占比相对较为稳定。  相似文献   
996.
火力发电厂煤粉锅炉炉膛爆炸原因解析   总被引:1,自引:0,他引:1  
夏术军  任嘉 《安全》2006,27(3):12-14
文章论述火力发电厂锅炉炉膛爆炸产生的原因,并采用事故树分析方法对锅炉炉膛爆炸原因做定性分析,采用布尔代数运算法则确定各基本事件引起炉膛爆炸事故的排列顺序.  相似文献   
997.
Four popular thermally desorbable adsorbents used for air sampling (Tenax TA, Tenax GR, Carbopack B, and Carbopack X) are examined for the potential to form artifacts with ozone (O3) at environmental concentrations. The performance of these adsorbents for the ketone and aldehyde species identified as O3-adsorbent artifacts was also characterized, including recovery, linearity, and method detection limits (MDLs). Using gas chromatography/mass spectrometry, 13 different artifacts were identified and confirmed for both Tenax TA and Tenax GR, 9 for Carbopack B, but none for Carbopack X. Several O3 artifacts not reported previously were identified, including: pentanal, 3-hexanone, 2-hexanone, hexanal, 3-heptanone, and heptanal with Tenax TA; pentanal, 3-hexanone, 2-hexanone, hexanal, and 3-heptanone on Tenax GR; and 1-octene and 1-nonene with Carbopack B. Levels of straight-chain aldehyde artifacts rapidly diminished after a few cycles of adsorbent conditioning/O3 exposure, and concentrations could be predicted using a first-order model. Phenyl-substituted carbonyl artifacts (benzaldehyde and acetophenone) persisted on Tenax TA and GR even after 10 O3 exposure-conditioning cycles. O3 breakthrough through the adsorbent bed was most rapid in adsorbents that yielded the highest levels of artifacts. Overall, artifact composition and concentration are shown to depend on O3 concentration and dose, conditioning method, and adsorbent type and age. Calibrations showed good linearity, and most compounds had reasonable recoveries, for example, 90 +/- 15% for Tenax TA, 97 +/- 23% for Tenax GR, 101 +/- 24% for Carbopack B, and 79 +/- 25% (91 +/- 9% for n-aldehydes) for Carbopack X. Benzeneacetaldehyde recovery was notably poorer (22-63% across the four adsorbents). MDLs for several compounds were relatively high, up to 5 ng. By accounting for both artifact formation and method performance, this work helps to identify which carbonyl compounds can be measured using thermally desorbable adsorbents and which may be prone to bias because of the formation of O3-adsorbent artifacts.  相似文献   
998.
为了研究苯并(b)荧蒽这一典型的多环芳烃化合物对水生生物的毒性效应,测定了不同浓度(2.0、10.0和50.0 μg· L-1)苯并(b)荧蒽胁迫15 d和清水释放10 d后翡翠贻贝(Perna viridis)内脏团组织中抗氧化酶(CAT、SOD和GPx)活性和MDA含量的变化.结果表明,2.0 μg· L-1浓度组...  相似文献   
999.
Increasing populations are causing an increase in food demands, and the area of cultivated land expands every year. Inappropriate land transition from ecology to production results in the constant decline of the ecological security level and influences the regional sustainable development. Adjusting unreasonable land use mode and reconstructing natural land cover are important ways to maintain and improve the ecological environment. Also reclaiming farmland as areas for forests and grasslands (FRFG) is another way. Successful implementation of FRFG in China is the result of comprehensive effect of the multi-scales driving forces. This paper analyses the driving forces of FRFG in China on a national (country) -regional (province) - local (county) - household (farmer) level scale, and the results are: driving forces at the national scale include ecological and food security and the western development of China; at the regional scale, ecological and economic benefits become the main factors to influence the dimension of FRFG under the same policy. The driving forces can be divided into 6 types: industrial structure adjustment, water source protection, flood prevention, the Three-Gorge Project protection, reduction of the amount of sediment flowing into the Yellow River and wind erosion desertification prevention. The driving forces at the local scale can be divided into 12 types with developing leading industries, increasing farmers' income and improving agricultural production conditions as the main types; at the household scale, the national policy meeting farmers' demands and the optimization of individual interests are all driving forces.  相似文献   
1000.
介绍了端点衍射波的产生及其计算自身高度的原理,采用常规仪器及探头测量的方法及体会。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号