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   1203篇
  免费   85篇
  国内免费   408篇
安全科学   106篇
废物处理   49篇
环保管理   100篇
综合类   737篇
基础理论   216篇
污染及防治   311篇
评价与监测   63篇
社会与环境   57篇
灾害及防治   57篇
  2024年   6篇
  2023年   24篇
  2022年   77篇
  2021年   57篇
  2020年   46篇
  2019年   40篇
  2018年   57篇
  2017年   48篇
  2016年   59篇
  2015年   62篇
  2014年   81篇
  2013年   98篇
  2012年   73篇
  2011年   91篇
  2010年   75篇
  2009年   74篇
  2008年   75篇
  2007年   50篇
  2006年   71篇
  2005年   53篇
  2004年   35篇
  2003年   56篇
  2002年   69篇
  2001年   63篇
  2000年   35篇
  1999年   38篇
  1998年   52篇
  1997年   29篇
  1996年   26篇
  1995年   14篇
  1994年   23篇
  1993年   14篇
  1992年   11篇
  1991年   4篇
  1990年   3篇
  1988年   2篇
  1987年   2篇
  1984年   1篇
  1983年   2篇
排序方式: 共有1696条查询结果,搜索用时 0 毫秒
351.
环境风险评价研究进展   总被引:2,自引:0,他引:2  
本文论述了环境风险评价研究的有关基本概念,以及主要研究内容的发展,指出了风险评价中存在的不足,并在比基础上提出了一些建议  相似文献   
352.
炼油厂轻污染水回用试验研究   总被引:2,自引:0,他引:2  
针对某炼油厂轻污染废水水质情况,选用了BAF(生物曝气滤池)工艺+SF(砂滤)工艺对该废水进行净化处理。通过试验研究,得到了BAF工艺合适的运行参数,取得了满意的试验结果。经BAF工艺处理后,出水COD和油平均浓度分别为9.78mg/L和0.24mg/L,再经SF工艺进一步去除SS后,出水SS平均浓度为3.8mg/L,系统处理出水完全达到工业回用水水质要求。试验证明:BAF工艺是一种高效的处理方法,适合炼油厂轻污染水的净化处理。  相似文献   
353.
膜生物反应器的研究及在废水处理中的应用   总被引:5,自引:0,他引:5  
综合论述了膜生物反应器的发展概况、基本原理、技术特点及分类等。  相似文献   
354.
对纺织染整、化工、制药、食品加工各行业生产废水及城镇污水厂处理设施出水中的TOC(自动仪器监测)与COD(实验室手工分析)测定值进行回归分析,并检验一元线性回归方程的显著性和有效性。结果表明,各行业生产废水中TOC与COD值均存在非常显著的相关性,且废水组成成分越单一稳定,其相关性越好,同行业废水中TOC与COD回归方程的斜率b较为接近。利用TOC自动在线监测值换算所得的COD值,准确性和稳定性高,能满足水质实时连续监测的需要。  相似文献   
355.
Mercury (Hg) could be microbially methylated to the bioaccumulative neurotoxin methylmercury (MeHg), raising health concerns. Understanding the methylation of various Hg species is thus critical in predicting the MeHg risk. Among the known Hg species, mercury sulfide (HgS) is the largest Hg reservoir in the lithosphere and has long been considered to be highly inert. However, with advances in the analytical methods of nanoparticles, HgS nanoparticles (HgS NPs) have recently been detected in various environmental matrices or organisms. Furthermore, pioneering laboratory studies have reported the high bioavailability of HgS NPs. The formation, presence, and transformation (e.g., methylation) of HgS NPs are intricately related to several environmental factors, especially dissolved organic matter (DOM). The complexity of the behavior of HgS NPs and the heterogeneity of DOM prevent us from comprehensively understanding and predicting the risk of HgS NPs. To reveal the role of HgS NPs in Hg biogeochemical cycling, research needs should focus on the following aspects: the formation pathways, the presence, and the environmental behaviors of HgS NPs impacted by the dominant influential factor of DOM. We thus summarized the latest progress in these aspects and proposed future research priorities, e.g., developing the detection techniques of HgS NPs and probing HgS NPs in various matrices, further exploring the interactions between DOM and HgS NPs. Besides, as most of the previous studies were conducted in laboratories, our current knowledge should be further refreshed through field observations, which would help to gain better insights into predicting the Hg risks in natural environment.  相似文献   
356.
BOD5测定中的影响因素   总被引:1,自引:0,他引:1  
BOD5的测定方法众多,文中从实验用水的质量、接种稀释液的要求、COD5值的确定、计算结果的取舍等方面予以分析.提出经验性的建议和办法。  相似文献   
357.

Green finance is not just a global trend, but it has become an important channel for industrialized countries to achieve sustainable growth. However, few studies have discussed the environmental governance effects of green finance from the micro-firm level. Based on the data of Chinese A-share listed firms in heavily polluting industries, we, combining with property rights and environmental regulation, empirically research the influence of green finance on corporate environmental responsibility (CER) performance. Results indicate that green finance has a significant negative effect on the environmental responsibility of heavily polluting firms. The result remains after a series of robustness tests. In addition, property rights and environmental regulation play a moderating role in the above relationship. The negative impact of green finance on CER is stronger in private firms and firms in areas with low environmental regulation intensity. Moreover, we observe that green finance decreases the CER performance of heavily polluting firms by increasing financing constraints, reducing environmental investment, and diminishing technological innovation. This study identifies the external factors that influence CER and also provides implications and theoretical support for the government to improve the setting and the implementation of green finance policy in the future.

  相似文献   
358.
● Environmental parameters affected functional bacteria and network associations. ● The structure and interactions of AS networks changed greatly within tanks. ● Anoxic co-occurrence network was more unstable and easily influenced. ● Composition of functional bacteria had a seasonal succession pattern. Tetrasphaera was the major PAO in spring and winter leading a better P removal. Understanding the structures and dynamics of bacterial communities in activated sludge (AS) in full-scale wastewater treatment plants (WWTPs) is of both engineering and ecological significance. Previous investigations have mainly focused on the AS communities of WWTP aeration tanks, and the differences and interactions between the communities in anaerobic and anoxic tanks of the AS system remain poorly understood. Here, we investigated the structures of bacterial communities and their inter-connections in three tanks (anaerobic, anoxic, and aerobic) and influent from a full-scale WWTP with conventional anaerobic/anoxic/aerobic (A/A/O) process over a year to explore their functionality and network differentiation. High-throughput sequencing showed that community compositions did not differ appreciably between the different tanks, likely due to the continuous sludge community interchange between tanks. However, network analysis showed significant differences in inter-species relationships, OTU topological roles, and keystone populations in the different AS communities. Moreover, the anoxic network is expected to be more unstable and easily affected by environmental disturbance. Tank-associated environmental factors, including dissolved oxygen, pH, and nutrients, were found to affect the relative abundance of functional genera (i.e., AOB, NOB, PAOs, and denitrifiers), suggesting that these groups were more susceptible to environmental variables than other bacteria. Therefore, this work could assist in improving our understanding of tank-associated microbial ecology, particularly the response of functional bacteria to seasonal variations in WWTPs employing A/A/O process.  相似文献   
359.
光离子检测器测定大气中溴甲烷   总被引:1,自引:0,他引:1  
用Tenax作为吸附剂捕集大气中的痕量溴甲烷,用气相色谱法和光离子检测器,对其进行检测,相对偏差为0.0521,最小检测限为10pg。室内外大气中的浓度分别为24×10(-12)(V/V)和77.4×10(-12)(V/V),污染在10(-11)(V/V)水平。  相似文献   
360.
采用不同质量浓度的溴氰菊酯(0.0070 mg·L~(-1)、0.014 mg·L~(-1)、0.020 mg·L~(-1)、0.027 mg·L~(-1))对菲律宾蛤仔进行20 d半静置染毒,测定不同时间淋巴液中乙酰胆碱酯酶(ACh E)和钠离子-钾离子-三磷酸腺苷酶(Na~+-K~+-ATPase)活性、鳃和肝脏中谷胱甘肽转硫酶(GST)活性的变化,并观察染毒20 d后鳃丝组织和消化盲囊组织的损伤情况。酶活性分析结果显示,与对照组相比,低浓度组(0.0070 mg·L~(-1))试验期间酶活性均无显著差异(P0.05);中浓度组(0.014 mg·L~(-1)、0.020 mg·L~(-1))淋巴液中ACh E和Na~+-K~+-ATPase均呈先激活后抑制的变化规律(P0.05),鳃和肝脏中GST活性均呈上升趋势(P0.05);高浓度组(0.027mg·L~(-1))淋巴液中ACh E和Na~+-K~+-ATPase、肝脏中GST活性在试验期间持续下降(P0.01),而鳃中GST活性呈先抑制后升高的趋势(P0.05)。研究表明,低中浓度的溴氰菊酯对菲律宾蛤仔体内的酶活性表现为先诱导后抑制,具有明显的时间、剂量效应;高浓度的溴氰菊酯对菲律宾蛤仔体内酶活持续抑制,且染毒浓度越高,组织细胞变异越显著,表现为鳃丝上皮细胞纤毛层萎缩、纤毛脱落,消化盲囊上皮细胞膨胀,出现包涵体样结构。  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