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   4243篇
  免费   431篇
  国内免费   1561篇
安全科学   464篇
废物处理   136篇
环保管理   345篇
综合类   3008篇
基础理论   717篇
污染及防治   909篇
评价与监测   267篇
社会与环境   248篇
灾害及防治   141篇
  2024年   39篇
  2023年   110篇
  2022年   274篇
  2021年   278篇
  2020年   310篇
  2019年   201篇
  2018年   236篇
  2017年   261篇
  2016年   235篇
  2015年   272篇
  2014年   308篇
  2013年   396篇
  2012年   403篇
  2011年   408篇
  2010年   344篇
  2009年   328篇
  2008年   295篇
  2007年   305篇
  2006年   220篇
  2005年   158篇
  2004年   124篇
  2003年   117篇
  2002年   109篇
  2001年   119篇
  2000年   109篇
  1999年   60篇
  1998年   41篇
  1997年   38篇
  1996年   32篇
  1995年   19篇
  1994年   33篇
  1993年   19篇
  1992年   15篇
  1991年   1篇
  1990年   7篇
  1989年   4篇
  1988年   3篇
  1987年   2篇
  1985年   1篇
  1984年   1篇
排序方式: 共有6235条查询结果,搜索用时 15 毫秒
101.
China’s large population and deteriorating environment have created great concern related to the sustainability of food production, especially since details related to this topic remain poorly studied. Thus, an integrated analysis of both crop yield and cultivated area is essential for gaining a better understanding of cereal grain production in China and for making corresponding policies designed to achieve food security. In this study, we adopt trend analysis of both provincial yield and cultivated area to assess the subsequent provincial-level cereal production sustainability between 1980 and 2011 with the goal of providing a better understanding of regional agricultural development. The results indicate that while maize shows the most promise for yield improvement, rice and wheat production is experiencing substantial yield stagnation among most provinces across mainland China. In addition, the trends in spatial patterns are prominently different from those of yields. The sizes of the main rice- and wheat-growing areas in China have declined greatly, suggesting that the related production of these cereals should attract more attention from land management planners and farmers. Specifically, the south-eastern coastal provinces have largely failed to sustain both crop yield and area, while the north-eastern provinces have witnessed thriving agricultural production during the last three decades. Moreover, we find that cereal production in China is significantly affected by governmental policies related to the agricultural sector. Thus, this analysis of food production in China will help policymakers to better understand how the potential implications of food security in China may be applicable to countries worldwide.  相似文献   
102.
Environmental Science and Pollution Research - A large amount of biochar-derived dissolved organic matter (BDOM) will be released into the environment with biochars application into repairing...  相似文献   
103.
Environmental Science and Pollution Research - Nitrogen-doped carbon nanotubes (N-CNTs) were synthesized via a hydrothermal method and further modified with magnetic Co0.5Cu0.5Fe2O4 nanoparticles...  相似文献   
104.
Environmental Science and Pollution Research - In the process of water treatment, excessive nitrogen and phosphorus pollutants are of great concern. Therefore, we prepared nanoscale zerovalent iron...  相似文献   
105.
Environmental Science and Pollution Research - Considering the bargaining power of enterprises, this paper distinguishes between “Offering Bribes Voluntarily” (OBV) and “Offering...  相似文献   
106.

Characterization of the typical petroleum pollutants, polycyclic aromatic hydrocarbons (PAHs) and n-alkanes, and indigenous microbial community structure and function in historically contaminated soil at petrol stations is critical. Five soil samples were collected from a petrol station in Beijing, China. The concentrations of 16 PAHs and 31 n-alkanes were measured by gas chromatography-mass spectrometry. The total concentrations of PAHs and n-alkanes ranged from 973 ± 55 to 2667 ± 183 μg/kg and 6.40 ± 0.38 to 8.65 ± 0.59 mg/kg (dry weight), respectively, which increased with depth. According to the observed molecular indices, PAHs and n-alkanes originated mostly from petroleum-related sources. The levels of ΣPAHs and the total toxic benzo[a]pyrene equivalent (ranging from 6.41 to 72.54 μg/kg) might exert adverse biological effects. Shotgun metagenomic sequencing was employed to investigate the indigenous microbial community structure and function. The results revealed that Proteobacteria and Actinobacteria were the most abundant phyla, and Nocardioides and Microbacterium were the important genera. Based on COG and KEGG annotations, the highly abundant functional classes were identified, and these functions were involved in allowing microorganisms to adapt to the pressure from contaminants. Five petroleum hydrocarbon degradation-related genes were annotated, revealing the distribution of degrading microorganisms. This work facilitates the understanding of the composition, source, and potential ecological impacts of residual PAHs and n-alkanes in historically contaminated soil.

  相似文献   
107.
Environmental Science and Pollution Research - The pollution of heavy metals (HMs) in the soil has become one of the important factors affecting the national environment and human health....  相似文献   
108.
Environmental Science and Pollution Research - With the increasingly serious pollution of plastics, biodegradable plastics (BDPs) have attracted attention as a new material that can replace...  相似文献   
109.
Environmental Science and Pollution Research - This paper analyzes the theoretical mechanism and transmission channel for the impact of air pollution on firms’ domestic value-added ratio...  相似文献   
110.
Environmental Science and Pollution Research - Polycyclic aromatic hydrocarbons (PAHs) in air, soil, and cultivated plants at e-waste disposal sites in Taizhou, Zhejiang Province, were determined...  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