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   131篇
  免费   25篇
  国内免费   87篇
安全科学   17篇
废物处理   17篇
环保管理   8篇
综合类   117篇
基础理论   34篇
污染及防治   40篇
评价与监测   5篇
社会与环境   1篇
灾害及防治   4篇
  2024年   1篇
  2023年   4篇
  2022年   22篇
  2021年   9篇
  2020年   24篇
  2019年   9篇
  2018年   9篇
  2017年   11篇
  2016年   16篇
  2015年   18篇
  2014年   21篇
  2013年   11篇
  2012年   13篇
  2011年   13篇
  2010年   17篇
  2009年   10篇
  2008年   7篇
  2007年   2篇
  2006年   7篇
  2005年   2篇
  2004年   3篇
  2003年   1篇
  2002年   1篇
  2000年   2篇
  1999年   3篇
  1998年   1篇
  1997年   1篇
  1996年   2篇
  1994年   2篇
  1988年   1篇
排序方式: 共有243条查询结果,搜索用时 156 毫秒
21.
Photovoltaic (PV) power generation has high investment costs and long payback periods. Therefore, during early deployment, subsidies are fundamental and necessary to accelerate its development. We consider the question of how to promote PV industry development and which supporting policy is more efficient in accelerating adoption. Based on real options method, we establish a subsidy efficiency model for electricity price subsidies and carbon-trading subsidies under two sources of uncertainty power demand for PV and the investment cost-reduction probability. This study aims to compare the two forms of subsidies from the perspective of promoting immediate investment and maximizing the subsidy policy efficiency for the government (minimizing the unit carbon-mitigation cost) and advance relevant policy proposals. An example of China is provided to test the effectiveness of the model and to illustrate the implications of the solutions. The results show that a carbon-trading subsidy is better than an electricity price subsidy and that it is essential to improve the demand for the power produced by the PV power-generation projects. Lower market risk and driving technology progress are both conducive to improving the subsidy efficiency. This study also provides a meaningful reference for governments worldwide to formulate subsidy programs to support PV power-generation projects.  相似文献   
22.
Photodegradation mechanism of deltamethrin and fenvalerate   总被引:1,自引:0,他引:1  
To understand the degradation and environmental fate of pyrethroids, the process of their photodegradation under simulated natural conditions was investigated. The results showed that the degradation process follows first-order kinetics. The degradation intermediates were identified with gas chromatography-mass spectrometry. A plausible mechanism was discussed to explain the process. Several influences on degradation process were investigated and reported such as the e ects of initial concentration of pyrethroids, total time of light irradiation, solvents, and light source, as well as the e ect of a few substances that exist in the environment. This study could be a good reference for the degradation of pyrethroids in practical circumstances.  相似文献   
23.
印染污泥混燃特性及其燃烧动力学模型   总被引:1,自引:0,他引:1  
采集了广东某印染污泥(YR)、造纸污泥(ZZ)及两种市政污水污泥(LJ、KFQ),利用热重法对不同来源污泥的单一及混合样在不同焚烧条件下进行了热重实验研究,并通过TG-DTG曲线计算了各试样的综合燃烧特性指数,获得了其燃烧动力学参数.结果表明,各单一试样的燃烧主要分为水分析出、挥发分析出、固定碳燃烧和残留物的燃烧和分解4个燃烧阶段,其中挥发分的析出制约着YR、KFQ、LJ污泥的整个燃烧过程,而ZZ污泥还受到固定碳燃烧阶段的显著影响.当向印染污泥中加入50%的KFQ市政污泥后,YR污泥的综合燃烧特性指数和可燃性指数分别提高了将近2倍和1.6倍.富氧(CO2/O2)燃烧可以提高印染污泥的后期燃烧强度,降低印染污泥燃烧阶段活化能,促进印染污泥的综合燃烧性能.采用积分法(Coats-Redfern方程)计算得到各燃烧阶段反应的机理方程及相应的活化能参数,发现第一挥发分峰前取反应级数n=0.5、峰后n=2,可描述各自阶段的燃烧反应机理,而第二挥发分峰没有显著规律.  相似文献   
24.
A laboratory study was conducted to investigate volatile organic compound(VOC) emissions from agricultural soil amended with wheat straw and their associations with bacterial communities for a period of 66 days under non-flooded and flooded conditions. The results indicated that ethene, propene, ethanol, i-propanol, 2-butanol, acetaldehyde, acetone,2-butanone, 2-pentanone and acetophenone were the 10 most abundant VOCs, making up over 90% of the total VOCs released under the two water conditions. The mean emission of total VOCs from the amended soils under the non-flooded condition(5924 ng C/(kg·hr)) was significantly higher than that under the flooded condition(2211 ng C/(kg·hr)). One "peak emission window" appeared at days 0–44 or 4–44, and over 95% of the VOC emissions occurred during the first month under the two water conditions. Bacterial community analysis using denaturing gradient gel electrophoresis(DGGE) showed that a relative increase of Actinobacteria, Bacteroidetes, Firmicutes and γ-Proteobacteria but a relative decrease of Acidobacteria with time were observed after straw amendments under the two water conditions. Cluster analysis revealed that the soil bacterial communities changed greatly with incubation time, which was in line with the variation of the VOC emissions over the experimental period. Most of the above top 10 VOCs correlated positively with the predominant bacterial species of Bacteroidetes, Firmicutes and Verrucomicrobia but correlated negatively with the dominant bacterial species of Actinobacteria under the two water conditions. These results suggested that bacterial communities might play an important role in VOC emissions from straw-amended agricultural soils.  相似文献   
25.
从审核方案策划和审核实施策划两个方面就审核策划的增值方案制订、实施方式和途径进行了探讨。  相似文献   
26.
环境风险评价研究进展   总被引:2,自引:0,他引:2  
环境风险评价是环境管理决策过程的重要组成部分,更是社会经济可持续发展的需要,也是环境科学发展的必然结果。经过几十年的发展,环境风险评价的科学理论体系已基本形成。主要介绍了环境风险评价的相关概念和发展情况,包括环境风险评价的研究内容、一般程序和评价方法,讨论了环境风险评价中的不确定性问题,给出了处理不确定性问题的两种方法-概率论和模糊理论,最后,在此基础上提出加强应用研究,以及多学科交叉和不确定性研究是今后环境风险评价的重要发展方向。  相似文献   
27.
在简要介绍目前含有高浓度油脂废水的产生和排放现状之后,总结分析了最近几年来一些具有一定代表性的生物处理方法的研究成果,同时提出了今后油脂废水处理技术的一点建议。  相似文献   
28.
转炉烟气净化系统中烟气的分析和量的计算   总被引:1,自引:0,他引:1  
转炉煤气干法净化回收技术已被认定为转炉煤气处理技术的今后发展方向。我国在转炉煤气干法净化回收技术方面已经做了全面深入的研究,并于2006年创新性地开发出了完全适合我国转炉炼钢的转炉煤气干法净化回收系统。设计转炉煤气干法净化回收系统的第一步也是最关键的一步,就是转炉烟气的分析和烟气量的准确计算。  相似文献   
29.
基因工程菌的发酵及偶氮染料脱色研究   总被引:3,自引:0,他引:3  
考察了本实验室自行构建的基因工程菌pGEX-AZR/E.coli JM-109的培养条件(碳源、氮源及其量的选择,接种量、温度、pH值);并考察其偶氮染料脱色能力范围。  相似文献   
30.
Cai  Yujie  Zhang  Xinhua  Xue  Ruiying  Wang  Ming  Deng  Qing 《Environmental Fluid Mechanics》2022,22(4):839-863
Environmental Fluid Mechanics - Based on the mechanism of landslide dam failure caused by overtopping, a simplified mathematical model for simulating dam breach overtopping flow processes was...  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