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   284篇
  免费   5篇
  国内免费   19篇
安全科学   13篇
废物处理   29篇
环保管理   25篇
综合类   60篇
基础理论   46篇
污染及防治   99篇
评价与监测   22篇
社会与环境   10篇
灾害及防治   4篇
  2023年   6篇
  2022年   9篇
  2021年   8篇
  2020年   3篇
  2019年   9篇
  2018年   10篇
  2017年   13篇
  2016年   12篇
  2015年   10篇
  2014年   11篇
  2013年   21篇
  2012年   16篇
  2011年   19篇
  2010年   15篇
  2009年   14篇
  2008年   20篇
  2007年   15篇
  2006年   16篇
  2005年   11篇
  2004年   6篇
  2003年   9篇
  2002年   9篇
  2001年   7篇
  2000年   6篇
  1999年   7篇
  1998年   3篇
  1997年   4篇
  1994年   4篇
  1993年   2篇
  1991年   1篇
  1990年   1篇
  1988年   1篇
  1987年   2篇
  1984年   1篇
  1981年   1篇
  1979年   1篇
  1977年   1篇
  1964年   1篇
  1961年   1篇
  1958年   2篇
排序方式: 共有308条查询结果,搜索用时 265 毫秒
171.
UASB和EGSB反应器中厌氧颗粒污泥生物学特性的比较   总被引:10,自引:0,他引:10  
测定了实验室规模的2L EGSB和UASB反应器中培养的厌氧颗粒污泥在不同基质中的比产甲烷活性、辅酶F420含量和胞外多聚酶物含量,结果表明,EGSB反应器颗粒污泥在葡萄糖上的比产甲烷活性、利用乙酸的甲烷菌和产氢产乙酸菌的活怀和胞外多聚物/含量高于UASB反应器颗粒污泥,而UASB反应器颗粒污泥中利用甲酸和氢的甲烷菌的活性以及辅酶F420的含量较EGSB反应器颗粒污泥更高,辅酶F420可以指示同种  相似文献   
172.
Environmental Science and Pollution Research - A large amount of silver-rich wastewater is generated from different industrial processes. This wastewater is not considered a waste, but a valuable...  相似文献   
173.
Following the export success of the South Korean small modular reactor (SMR), it has been investigated for the marketing strategy of nuclear power plants (NPPs). The information feedback oriented method for the social-business matters, system dynamics (SD), is applied to the assessment of the marketing strategy in which the forecasting skills are performed. Each element has the Boolean value as 0 or 1 in which the values are selected by the random number generation. If the generated values are higher than the designed value decided by the operator, it is 1. Otherwise, it is 0. The networking based dynamical modeling is discussed. The modification of the linear networking is changed by the SD algorithm where the feedback and multiple connections are added to the original network dynamics theory. This new method has shown the complexity of the marketing strategy, especially for the NPPs.  相似文献   
174.
The device performance of double-pass V-corrugated solar air heaters with external recycle was investigated experimentally and theoretically. The comparison between V-corrugated and flat-plate collectors was made to show the thermal efficiency improvement with various operating parameters. The results show that the collector efficiency improvement of the recycling double-pass V-corrugated operation is much higher than those of the other configurations under various recycle ratios and mass flow rates. However, there exists the penalty on the power consumption increment due to implementing V-corrugated channel into the solar air heaters, an economic consideration on both the heat-transfer efficiency enhancement and power consumption increment for the double-pass V-corrugated device was also delineated. The experimental setup was carried out to validate the theoretical predictions, and the fairly good agreement between both results was achieved with the error analysis of 0.48-1.83%.  相似文献   
175.
In order to understand the water quality and the genotoxicity of various surfaces in the Guangzhou section of the Pearl River during January to December of 2008, we investigated and studied the current water situation of the surface microlayer (SML) and the subsurface water (SSW) in Guanzhou section (Zhongda Dock and Yuzhu Dock) of the Pearl River by chemical analysis and biological monitoring method (Vicia faba micronucleus test). The results showed that during these months concentrations of the indexes of the two docks water such as total nitrogen (TN), total phosphorus (TP), chemical oxygen demand (COD) exceeded the national III level of surface water quality, and the indexes of SML were much higher than the ones of SSW (P?< 0.05), and the exceeding rate of TN, TP of SML was 100%. According to the eutrophic evaluation standard, the water bodies of SML and SSW in the two docks were in a eutrophication during these months. The eutrophication and pollution of SML was more serious, and the highest index of eutrophication (E value) was up to 81.9, which also had obvious difference with COD and TP (P?< 0.05). The water of SML in the two docks enriched to N, P, and chlorophyll a (Chl. a) seriously, and the enrichment factor of SML in Zhongda Dock to N, P, and Chl. a was 0.71 ?? 2.78, 0.98 ?? 1.18, and 0.49 ?? 13.99, respectively, and the one in the Yuzhu Dock was 1.09 ?? 1.52, 1 ?? 1.14, and 0.72 ?? 4.07, respectively. Through inspecting the water genotoxicity of various layers by V. faba micronucleus test, we could know that the average annual MCN?? of SML and SSW in the two docks was 6.09??, 5.53??, 5.57??, and 5.249??, respectively. In general, the above value of SML was a little higher than the one of SSW, but there was not a remarkable difference (P?> 0.05). This research shows that the water quality in a medium to heavy eutrophication in the Guangzhou section of Pearl River belongs to national III ?? IV level, and SML has the capability of enrichment to the pollutants such as N and P and induces the increase of micronucleus rate of V. faba tip cell. The study also indicates that there may be genotoxicity matters such as N, P in water body.  相似文献   
176.
● Methanol effectively reduces CO, HC, CO2, PM, and PN emissions of gasoline vehicles. ● Elemental composition of methanol directly affects the reduction of emissions. ● Several physicochemical properties of methanol help reduce vehicle emissions. The transport sector is a significant energy consumer and a major contributor to urban air pollution. At present, the substitution of cleaner fuel is one feasible way to deal with the growing energy demand and environmental pollution. Methanol has been recognized as a good alternative to gasoline due to its good combustion performance. In the past decades, many studies have investigated exhaust emissions using methanol-gasoline blends. However, the conclusions derived from different studies vary significantly, and the explanations for the effects of methanol blending on exhaust emissions are also inconsistent. This review summarizes the characteristics of CO, HC, NOx, CO2, and particulate emissions from methanol-gasoline blended fuels and pure methanol fuel. CO, HC, CO2, particle mass (PM), and particle number (PN) emissions decrease when methanol-blended fuel is used in place of gasoline fuel. NOx emission either decreases or increases depending on the test conditions, i.e., methanol content. Furthermore, this review synthesizes the mechanisms by which methanol-blended fuel influences pollutant emissions. This review provides insight into the pollutant emissions from methanol-blended fuel, which will aid policymakers in making energy strategy decisions that take urban air pollution, climate change, and energy security into account.  相似文献   
177.
Environmental Science and Pollution Research - The effects of air pollution on sleep and dementia remain unclear. The objective of this study was to investigate the effects of air pollution on...  相似文献   
178.
Environmental Science and Pollution Research - To enhance dye removal and energy recovery efficiencies in single-pair electrode photocatalytic fuel cell (PFC-AC), dual cathodes PFC (PFC-ACC) and...  相似文献   
179.
Metal capture experiments were carried out in an atmospheric fluidized bed incinerator to investigate the effect of sulfur and chlorine on metal capture efficiency and the potential for simultaneous capture of metal, sulfur and chlorine by sorbents. In addition to experimental investigation, the effect of sulfur and chlorine on the metal capture process was also theoretically investigated through performing equilibrium calculations based on the minimization of system free energy. The observed results have indicated that, in general, the existence of sulfur and chlorine enhances the efficiency of metal capture especially at low to medium combustion temperatures. The capture mechanisms appear to include particulate scrubbing and chemisorption depending on the type of sorbents. Among the three sorbents tested, calcined limestone is capable of capturing all the three air pollutants simultaneously. The results also indicate that a mixture of the three sorbents, in general, captures more metals than a single sorbent during the process. In addition, the existence of sulfur and chlorine apparently enhances the metal capture process.  相似文献   
180.
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