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   648篇
  免费   31篇
  国内免费   236篇
安全科学   44篇
废物处理   50篇
环保管理   46篇
综合类   349篇
基础理论   136篇
污染及防治   210篇
评价与监测   26篇
社会与环境   26篇
灾害及防治   28篇
  2023年   10篇
  2022年   28篇
  2021年   23篇
  2020年   15篇
  2019年   18篇
  2018年   21篇
  2017年   25篇
  2016年   23篇
  2015年   41篇
  2014年   52篇
  2013年   72篇
  2012年   48篇
  2011年   61篇
  2010年   45篇
  2009年   35篇
  2008年   38篇
  2007年   53篇
  2006年   36篇
  2005年   29篇
  2004年   18篇
  2003年   26篇
  2002年   21篇
  2001年   18篇
  2000年   23篇
  1999年   27篇
  1998年   17篇
  1997年   16篇
  1996年   15篇
  1995年   9篇
  1994年   9篇
  1993年   9篇
  1992年   10篇
  1991年   7篇
  1990年   7篇
  1989年   3篇
  1988年   1篇
  1987年   1篇
  1986年   2篇
  1982年   2篇
  1981年   1篇
排序方式: 共有915条查询结果,搜索用时 31 毫秒
321.
采用鼓泡法研究了海水及浓海水对二氧化硫的吸收效果,并考察了吸收液温度、气体流量、盐度及碱度等因素的影响.结果表明,相同条件下,浓海水对二氧化硫的吸收能力较海水明显提高,且温度越高浓海水优势越明显,气体流量为200 mL/min,二氧化硫浓度为3 140 mg/m3,25℃时,浓海水的穿透时间较原海水延长20 min,60℃时则延长30 min.相同碱度条件下,盐度的增加对海水吸收二氧化硫无明显影响;而在相同盐度条件下,碱度的增加可显著提高海水吸收二氧化硫的能力.  相似文献   
322.
研究了吸附剂浓度(Cs)对Zn(Ⅱ)和Cd(Ⅱ)在高岭土上吸附的影响。结果表明,随Cs增大,吸附等温线下降,呈现出明显的吸附剂浓度效应(Cs-effect)。采用经典Langmuir和Freundlich吸附等温式对吸附数据进行拟合表明,在给定Cs下,Zn(Ⅱ)和Cd(Ⅱ)的吸附等温线分别符合Langmuir和Freundlich等温式;但这2个等温式不能描述或预测Cseffect,模型参数与Cs有关,与模型理论预测相悖。为解释和描述固/液界面吸附中的Cs-effect,我们近期提出了表面组分活度(SCA)模型,并推导出了Langmuir-SCA和Freundlich-SCA等温式。采用SCA模型等温式对吸附数据进行拟合表明,Langmuir-SCA和Freundlich-SCA等温式可分别准确地描述Zn(Ⅱ)和Cd(Ⅱ)在高岭土上吸附的Cs-effect结果,证明SCA模型是合理的。  相似文献   
323.
济南市大气水平能见度与环境污染相关性分析   总被引:1,自引:0,他引:1  
利用济南市2011年1月1日至12月31日大气水平能见度在线监测小时数据和对应细颗粒物(PM2.5)、PM2.5中碳组分(EC和OC)、挥发性有机物(VOC)及气象参数资料,分析污染物、气象参数等对能见度的影响。结果显示,相对湿度和PM2.5是影响能见度的主要因子,能见度与相对湿度及PM2.5浓度主要呈指对数关系。结合相对湿度条件对PM2.5浓度与能见度关系进行综合分析,得到相关经验模型公式,并利用2010年6月1日至11月30日的相应数据资料进行实例关系验证,结果表明,建立的经验模型公式有较好的实际应用价值。  相似文献   
324.
In many locations across the world, land contamination poses a serious threat to human health and the wider environment. For instance, a report published on April 17, 2014, revealed that China now has 16.1 percent of its land contaminated by various organic and inorganic contaminants, posing a range of challenges from human health risk to food security. The innovation and adoption of suitable remediation technologies is critical for solving land contamination issues. However, little is known about the pattern of remediation technology adoption, as well as its determining factors. This study uses a questionnaire survey in the United States, United Kingdom, and China to examine the spatial variation of remediation technology adoption. It further explores the temporal trend of remediation technology adoption using secondary data from the U.S. Superfund program. The study identified significant differences in remediation technology adoption among these countries, which are attributed to the different environmental, social, economic, and regulatory contexts. It is argued that the full implications of remediation technology adoption to sustainable development should be further studied, and policy instruments should be designed accordingly to promote those remediation technologies that align the best with long‐term sustainability. Technology developers may also use these implications to adjust their research and development priorities. © 2014 Wiley Periodicals, Inc.  相似文献   
325.
The accumulation of heavy metals in farmland has become an important issue related to food security and environmental risk. The annual inputs of heavy metals (As, Cd, Hg, Pb, Cr, Cu, and Zn) to agricultural soil for a full year in Hainan Island have been studied. Three fluxes through the cultivated horizon were considered: (1) atmospheric depositions, (2) fertilization, and (3) irrigation water. The corresponding samples were collected and analyzed on a large regional scale. The total input fluxes show obvious spatial variability among different regions. The inventory of heavy metal inputs to agricultural land demonstrates that agricultural soil is potentially at risk of heavy metal accumulation from irrigation water. The potential at risk of heavy metal accumulation from atmospheric deposition and fertilizer is relatively low compared to irrigation. The results indicate that Hg is the element of prior concern for agricultural soil, followed by Cd and As, and other heavy metal elements represent little threat to the environment in the study area. This work provides baseline information to develop policies to control and reduce toxic elements accumulated in agricultural soil.  相似文献   
326.
Industrialization and urbanization have led to a great deterioration of air quality and provoked some serious environmental concerns. One hundred and five samples of atmospheric deposition were analyzed for their concentrations of 13 trace elements (As, Cd, Cu, Fe, Al, Co, Cr, Hg, Mn, Mo, Pb, Se, and Zn) in Shanxi Basin, which includes six isolate basins. The input fluxes of the trace elements in atmospheric deposition were observed and evaluated. Geostatistical analysis (EF, PCA, and CA ) were conducted to determine the spatial distribution, possible sources, and enrichment degrees of trace elements in atmospheric deposition. Fe/Al and K/Al also contribute to identify the sources of atmospheric deposition. The distribution of trace elements in atmospheric deposition was proved to be geographically restricted. The results show that As, Cd, Pb, Zn, and Se mainly come from coal combustion. Fe, Cu, Mn, Hg, and Co originate mainly from interactions between local polluted soils and blowing dust from other places, while the main source of Al, Cr, and Mo are the soil parent materials without pollution. This work provides baseline information to develop policies to control and reduce trace elements, especially toxic elements, from atmospheric deposition. Some exploratory analytical methods applied in this work are also worth considering in similar researches.  相似文献   
327.
通过检测活性污泥的电子传递体系活性以及生物多样性,研究Ni2+对活性污泥微生物活性及群落多样性的影响。结果表明:与对照系统相比,5mg/L的Ni2+对2,3,5-lriphenylteItrazoliumchloride(TTC.ETS)活性未产生显著的影响;但当Ni2+的浓度进一步增大到10、20和40mg/L后,其对序批式反应器内活性污泥TTC—ETS活性的抑制率分别达到(36.794-11.14)%、(55.88±13.90)%和(70.97±6.78)%。低浓度Ni2+.能增强活性污泥微生物对碳源的利用,但高于10mg/L的Ni2+则显著抑制了活性污泥微生物对碳源的利用。各个SBR系统中微生物群落最常见的物种相近,物种丰富度和均一性则均有所不同,其中群落物种丰富度随着Ni2+浓度的增加而逐渐减小。TTC—ETS活性、平均每孔颜色变化率、Shan—liOn指数和Simpson指数,与Ni2+的胁迫浓度之间的显著相关性表明,它们均可有效地表征Ni2+胁迫对活性污泥微生物活性及群落多样性的影响程度。  相似文献   
328.
There has been a growing movement within the environmental industry to develop more sustainable approaches in environmental remediation. These have generally included carbon footprint analysis, life cycle assessment, and best management practices to reduce the overall net environmental, social, and economic impacts of investigation and remediation activities. One of the foundational reasons net environmental impacts are currently evaluated is to identify and, subsequently, reduce contributions to climate change, primarily greenhouse gas emissions. While this trend toward sustainability and reduction in impact to the global environment is both important and admirable, the approach to remediation design and long‐term planning now needs to evolve further to better incorporate climate resilience into sustainable remediation design and implementation: designing remediation solutions that account for the projected impacts of climate change, as well as have the capacity to adapt to changing conditions. As a global population, we are now beyond the point of being able to prevent climate change and instead need to plan for adapting to it. In remediation, the effects of climate change create both risks and opportunities which should be considered during remedial design and long‐term planning. Responsible parties may see the push for—and management of—these considerations through their internal corporate risk management. The authors of this paper propose a simple framework for climate adaptation and resilience evaluations and plan development for remediation projects. ©2015 Wiley Periodicals, Inc.  相似文献   
329.
洗毛废水是洗毛生产工艺排出的兼具高COD、高悬浮固体浓度、高色度、难固液分离等典型特征,且对环境存在潜在污染的一类工业废水。通过摇瓶实验,研究了预酸化条件下,生物沥浸技术对洗毛废水的处理效果。结果表明,当洗毛废水经预酸化至p H 5.5、营养剂浓度≥4 g/L、回流比例为1∶1的情况下,3个批次实验内复合菌群生物沥浸过程稳定,洗毛废水能够很好地完成生物沥浸过程。反应结束后体系p H稳定在3.0左右,COD去除率高达90%以上,色度由原来的1 875倍降到20倍,沉淀中油脂去除率高于65%,且比阻降低至原来的0.2%~0.3%。而在对照处理中,体系p H值稳定在8.0左右,COD去除率小于10%,油脂去除率不足10%,洗毛废水比阻仅降低20%。因此,采用预酸化及生物沥浸作用有利于洗毛废水酸化处理的连续运行并具有良好的应用前景。  相似文献   
330.
通过监测西安可口可乐饮料有限公司污水处理站的上流式厌氧污泥床(UASB)反应器,探讨饮料废水厌氧处理过程中COD去除率、沼气组分、氢分压、出水挥发性脂肪酸、产甲烷活性以及污泥形态。结果表明,UASB反应器对饮料废水中的COD去除率达到84.55%,产生的沼气中甲烷组分含量高达74.5%。反应器内的氢分压仅2.5 Pa,为水解发酵和产氢产乙酸过程创造了良好的条件。UASB反应器中污泥具有较高的产甲烷活性,以乙酸、丙酸和丁酸为基质时,最大比产甲烷活性分别为407.14、331.74和241.27 m L CH4/(g VSS·d)。UASB反应器中的污泥形态主要为絮状,甲烷菌中的优势菌为甲烷丝菌,同时存在少量甲烷杆菌。针对该厂UASB反应器中污泥的现状,提出了影响颗粒化的因素和控制措施,为后期的运行和管理提供了参考依据。  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