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   126462篇
  免费   2527篇
  国内免费   10199篇
安全科学   5907篇
废物处理   5352篇
环保管理   17297篇
综合类   36446篇
基础理论   31609篇
环境理论   84篇
污染及防治   27904篇
评价与监测   7090篇
社会与环境   5609篇
灾害及防治   1890篇
  2023年   846篇
  2022年   2009篇
  2021年   1871篇
  2020年   1514篇
  2019年   1584篇
  2018年   2203篇
  2017年   2466篇
  2016年   3355篇
  2015年   3237篇
  2014年   4624篇
  2013年   11823篇
  2012年   4846篇
  2011年   5650篇
  2010年   5313篇
  2009年   5458篇
  2008年   4838篇
  2007年   4513篇
  2006年   4436篇
  2005年   3844篇
  2004年   3896篇
  2003年   3890篇
  2002年   3349篇
  2001年   3730篇
  2000年   3160篇
  1999年   2487篇
  1998年   2112篇
  1997年   2036篇
  1996年   2103篇
  1995年   2142篇
  1994年   1875篇
  1993年   1723篇
  1992年   1633篇
  1991年   1532篇
  1990年   1452篇
  1989年   1340篇
  1988年   1181篇
  1987年   1070篇
  1986年   1041篇
  1985年   1112篇
  1984年   1206篇
  1983年   1204篇
  1982年   1206篇
  1981年   1126篇
  1980年   960篇
  1979年   963篇
  1978年   833篇
  1977年   739篇
  1976年   669篇
  1973年   682篇
  1972年   685篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Zhu  Rong  Wang  Shixin  Srinivasakannan  C.  Li  Shiwei  Yin  Shaohua  Zhang  Libo  Jiang  Xiaobin  Zhou  Guoli  Zhang  Ning 《Environmental Chemistry Letters》2023,21(3):1611-1626
Environmental Chemistry Letters - The demand for lithium is growing rapidly with the increase in electric vehicles, batteries and electronic equipments. Lithium can be extracted from brines, yet...  相似文献   
12.
Russian Journal of Ecology - In this paper, Ellenberg’s indicator values were estimated in order to soil nitrogen (N), pH (R) and soil moisture (M) in different subalpine grassland...  相似文献   
13.

It is known that globalization has led first- and second-tier cities’ urban restructuring trajectories, excreted pressures, and caused tremendous socioeconomic volatility. This resulted in marginalized communities in dire of social empowerment, employment structure variance, and industry sectoral adjustment. Moreover, recent successive climate and health crisis unfolded and affirmed the state of our urban incompetence to sustain socioeconomic resilience or otherwise; lacking swift responses in providing critical management and services, cites are facing multifaceted challenges. Urban well-being and resilience are at stake. Although the environmental and health dimensional effects are apparent, this study ascertains that the transept multi-scalar analysis within the urban socioeconomic structure is crucial in sustaining core resilience to foster health and well-being of the community. As an integral part of the investigation, the revised DPSIR assessment framework is applied to evaluate the sectoral shift; spatial structure disarray and urban codependence degree are examined within the Taipei metropolitan area (TMA), a medium size but densely populated metropolitan area in Taiwan. The place-based DPSIR analysis ascertained the states and impacts in TMA: (1) A population decline speeded the restructuring of the urban core, while the impact of demographic aging and shrinkage rate mandates proper management and planning responses to the decline process; (2) the socioeconomic state effect is determined but does not critically affect the periphery zone, while an uneven demographic shift within the urban core necessitates dynamic adjustment responses to appropriately provide intergenerational services; (3) the uneven sector redistribution stimulated the core’s spatial and structural inter-dependency with peripheral zones, requiring governance with tighter cross-administration cooperation among respective public sectors; and (4) facing the sector/temporal and demographic pressure, urban cohesiveness in the TMA is greatly affected, which in turn disrupts the resilience pathway toward a cohesion. The study ascertained that the revised DPSIR framework could provide cities facing pressing socioeconomic drivers with effective analysis to allocate pressures, states, and impacts and formulate the necessary responses. To assure the socioeconomic resilience and urban cohesiveness, planning policy should carefully monitor and evaluate socio-demographic and sector redistribution factors to promote the urban resilience.

  相似文献   
14.
Environmental Science and Pollution Research - Nutrient source and transport study in tropical creeks adjacent to megacities are sparse on a regional and global scale. High-frequency chemical data...  相似文献   
15.
Catalytic activity of spinel ferrite in breaking down toxic dye materials are promising due to their uniqueness. In this study, aluminum-doped copper zinc ferrite, Cu0.4Zn0.6-xAlxFe2O4 (x = 0.0, 0.2, 0.4, 0.6), a catalyst for toxic dye degradation is synthesized through chemical co-precipitation route. The formation of the spinel ferrite catalyst is initially confirmed by Fourier transform infrared spectra, which shows the frequency of metal-oxygen bond vibration at 539 and 427 cm−1 attributed to the tetrahedral and octahedral sites respectively. Higher intensity sharp peak of X-ray diffraction for (311) plane is the evidence for the phase purity and the formation of spinel ferrite. The crystallite size is found to decrease with the increase of Al3+ ion. The surface structure of the obtained particles is investigated using a scanning electron microscope. Analyses of the material's magnetic characteristics using a vibrating sample magnetometer (VSM) revealed that it is, in fact, a soft magnet, as evidenced by the loop of its hysteresis, which is narrow. The catalytic degradation of methylene blue dye under the mechanism of the photo-Fenton process is studied with the obtained spinel ferrites and the result is found to be as high as 96.5%. The process follows pseudo-second order kinetics and the Langmuir isotherm.  相似文献   
16.
Huang  Ying  Jiang  Qiongji  Yu  Xubiao  Gan  Huihui  Zhu  Xia  Fan  Siyi  Su  Yan  Xu  Zhirui  He  Cunrui 《Environmental science and pollution research international》2021,28(37):51251-51264
Environmental Science and Pollution Research - Trace copper ion (Cu(II)) in water and wastewater can trigger peroxymonosulfate (PMS) activation to oxidize organic compounds, but it only works under...  相似文献   
17.
Russian Journal of Ecology - A new method for assessing the response of biota to climatic changes in the ecosystem has been tested. In the Central Forest Natural Biosphere Reserve, the average...  相似文献   
18.
Environmental Science and Pollution Research - The impact of high concentrations of air pollution on COVID-19 has been a major air quality and life safety issue in recent studies. This study aimed...  相似文献   
19.
20.
针对2018年3月9—15日京津冀地区的一次空气重污染过程,进行了基于地基颗粒物激光雷达组网的星载-地基联合观测分析。颗粒物激光雷达观测到污染前期为局地污染累积过程,中期有明显的污染物区域传输过程,北京受太行山沿线城市污染输送影响较大。风廓线激光雷达观测结果表明:此次污染过程近地面主要为偏南风且风力较弱,冷空气到来时风向转为较强东北风,导致污染消散。微波辐射计观测到保定在污染过程中出现持续6 d的逆温层,同时在污染过程中近地面相对湿度较高,逆温层被打破后污染开始消散。在污染过程的各个阶段中,污染团的空间分布与变化特征均被很好地反映出来,可见地天联合观测对污染物的累积与输送研究有较大的意义,能对京津冀及周边地区的大气污染联防联控提供有力支持。  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