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   1237篇
  免费   78篇
  国内免费   540篇
安全科学   89篇
废物处理   57篇
环保管理   128篇
综合类   717篇
基础理论   228篇
污染及防治   442篇
评价与监测   71篇
社会与环境   60篇
灾害及防治   63篇
  2024年   5篇
  2023年   30篇
  2022年   81篇
  2021年   62篇
  2020年   61篇
  2019年   50篇
  2018年   59篇
  2017年   74篇
  2016年   66篇
  2015年   75篇
  2014年   91篇
  2013年   122篇
  2012年   101篇
  2011年   128篇
  2010年   87篇
  2009年   84篇
  2008年   76篇
  2007年   67篇
  2006年   78篇
  2005年   56篇
  2004年   38篇
  2003年   27篇
  2002年   50篇
  2001年   38篇
  2000年   47篇
  1999年   40篇
  1998年   18篇
  1997年   27篇
  1996年   17篇
  1995年   18篇
  1994年   15篇
  1993年   23篇
  1992年   13篇
  1991年   12篇
  1990年   4篇
  1989年   3篇
  1988年   2篇
  1987年   4篇
  1986年   1篇
  1983年   2篇
  1982年   2篇
  1973年   1篇
排序方式: 共有1855条查询结果,搜索用时 0 毫秒
671.
大孔吸附树脂对烷基酚聚氧乙烯醚的吸附行为   总被引:2,自引:0,他引:2  
烷基酚聚氧乙烯醚(APEOn)是一类重要的非离子表面活性剂,由于其生物代谢产物被证实具有较大的毒性,因此引起人们广泛关注.本文使用两种不同的大孔吸附树脂XAD-4、NDA-804对APEOn类物质NP10进行吸附,该技术可为使用大孔吸附树脂去除此类污染物提供理论依据.研究结果表明:XAD-4、NDA-804对NP10都有较好的吸附效果,温度对吸附有较大的影响,升高温度吸附量增大.NDA-804对NP10的吸附效果要好于XAD-4,这与它的化学特性以及孔结构有关.NP1O在两种树脂上的吸附都能用Langmuir吸附等温线方程很好的拟合,表明属于单层分子吸附.吸附热力学参数计算结果表明,XAD-4、NDA-804对NP10的吸附过程是吸热和自发的.吸附动力学拟合结果表明,NP10在XAD-4、NDA-804上的吸附都符合假二级反应动力学.  相似文献   
672.
The deformation of microstructure of tailings caused by seepage is the main factor that leads the tailings dam to be damaged and lose stability. The effect of seepage on microstructure of tailings has been studied by a self-made observation testing apparatus of micro-mechanics and deformation of tailings, and its mechanism also has been explained in mechanics of particulate matter. The results show that the deformation response to microstructure of tailings is fast under load. The settlement of sample increases stepwise. Firstly, the fine particles crumble, then skeleton particles move, so as to noticeable settlement. Because the loose particles migrate taken by seepage water, the upper pores become bigger and lower pores become smaller. The relation of seepage water and settlement changing with time could be divided into two stages. In each stage, the rates of seepage and settlement reduce with time, and between the two stages, the rate of settlement increases significantly and the rate of seepage reduces with time. The seepage has significant effect on the particle size distribution of tailings in different depths, which has a little effect on the coarse tailings; the proportion of fine tailings increases significantly with the depth increasing; the minimum particle size decreases gradually and median diameter reduces stepwise with the depth increasing.  相似文献   
673.
含硫油品储罐腐蚀产物FeS的氧化自燃是引起储罐火灾爆炸事故的主要原因。用同步热分析仪(STA)在30~900℃范围内对FeS进行热重热流分析,从物理吸附和化学反应的角度分析了不同粒径和不同升温速率FeS的自然氧化倾向性,计算了不同升温速率FeS的活化能。结果表明,FeS样品粒径越小,越容易发生氧化自燃反应;升温速率越大,FeS越不容易氧化。同时,不同升温速率条件下的FeS反应机制各不相同。从实验得出的动力学参数看出,FeS的氧化反应较复杂,而非简单的放热反应。  相似文献   
674.
实验以处理金属表面所产生的磷化废水为研究对象,系统地分析了在新型混凝剂的使用过程中,pH值、温度、石灰投入量、沉降时间、助剂A等因素对脱磷效果的影响。结果表明,含磷量为18mg/L、COD为300mg/L、SS为150mg/L、pH值为5.7~6.5的废水,石灰投入量为300mg/L、沉降时间为10min左右、温度为25℃、pH值调节至9.0、加入5mL助剂A处理后,废水中磷含量为0.25~0.35mg/L、COD为80mg/L、SS为60mg/L,满足《污水综合排放标准》(GB8978—1996)中的一级标准。  相似文献   
675.
林恒  徐银  张晖 《化工环保》2015,35(4):333-338
介绍了几个国家在地表水、污水处理厂进出水等水环境中检测出的人工甜味剂的含量,简介了人工甜味剂对人体的危害,综述了基于臭氧氧化和紫外光照射的高级氧化技术处理水中人工甜味剂的研究进展,剖析了人工甜味剂的降解产物和降解路径以及在降解过程中的矿化效果和毒性变化,对后续的研究方向进行了展望。  相似文献   
676.
Yang  Sheng  Cheng  Yanping  Liu  Tong  Huang  Shaoping  Yin  Lihong  Pu  Yuepu  Liang  Geyu 《Environmental Chemistry Letters》2022,20(5):2951-2970
Environmental Chemistry Letters - During the Corona Virus Disease 2019 (COVID-19) pandemic, protective equipment, such as masks, gloves and shields, has become mandatory to prevent person-to-person...  相似文献   
677.

Local governments are the dominant players in haze pollution control; furthermore, financial power reconstruction affects the effectiveness of haze control. Government innovation preference achieves win-win results for environmental protection and economic development by increasing innovation support. Therefore, a moderating variable for government innovation preference was added to the fiscal decentralization effect on haze pollution, and their interactive effect on haze pollution was studied. This study was conducted in 30 provincial regions. Thus, the severity of regional haze pollution differs because of temporal heterogeneity and asynchronous development. Furthermore, we analyzed the impact on haze pollution from the perspectives of the temporal and spatial differences in different regions of China. The results indicate that (1) fiscal decentralization increases haze pollution, while government innovation preferences control it. (2) In a local evaluation model with a diversified background, fiscal decentralization restrains haze pollution, and pollution source complexity reduces government innovation preference’s control pollution function. The interaction term revealed that government innovation preferences had a significant moderating effect. (3) Fiscal decentralization and government innovation preferences control the heterogeneity of haze pollution in different regions.

  相似文献   
678.
Yin  Li  Wang  Juan  Shi  Kaipian  Zhang  Yong  Xu  Ying  Kong  Desheng  Ni  Lixiao  Li  Shiyin 《Environmental science and pollution research international》2022,29(55):83211-83219
Environmental Science and Pollution Research - The protective mechanism of extracellular polymeric substance (EPS) secreted by a harmful cyanobacteria against tannins allelochemicals was explored...  相似文献   
679.
In lizards, males are predicted to sprint faster and run for longer than females by virtue of higher testosterone levels and differences in morphology. Consequently, escape behaviour is also predicted to be associated with sex and locomotor performance, yet these links have rarely been explored. Here, we tested whether escape behaviour is associated with locomotor performance in the toad-headed agama, Phrynocephalus vlangalii, and whether it is sex-dependent. This species is also characterized by elaborate tail displays, which we examined as a potential pursuit-deterrent signal. Tail waves were performed by a very small proportion (2/58, 3 %) of individuals during predatory trials, suggesting that tail signalling functions exclusively in a social context. To understand the relationships between sex, escape behaviour and performance, we first measured escape behaviour (flight initiation distance, flight distance—measured differently compared to previous studies of lizard escape behaviour, and refuge use) in the field before measuring maximal sprint speed and endurance on the same individuals in the laboratory. Flight initiation distance did not differ between the sexes and was unrelated to performance capacity (maximal endurance and sprint speed) but was positively related to body size with larger individuals fleeing earlier. Males fled farther than females, but flight distance was also unrelated to either endurance or sprint speed. Interestingly, faster females were less likely to enter a refuge than slower females, whereas sprint speed and the probability of taking refuge were unrelated for males. Our results suggest that when males and females are not obviously sexually dimorphic, they are more likely to overlap in escape tactics.  相似文献   
680.
Fungal trophic modes and substrates utilization ability was observed in composting. Fungi had the higher diversity and more trophic types in thermophilic phase. Fungi had the higher metabolic potential in fresh swine manure and mature production. Redox potential, organics and moisture are main factors impacting fungal community. Composting reduced pathogenic fungi and enrich dung saprotroph fungi in swine manure. The succession of fungal community, trophic mode and metabolic characteristics were evaluated in 60 days composting of swine manure by high-throughput sequencing, FUNGuild and Biolog method, respectively. The result showed that the fungal community diversity reached to the highest level (76 OTUs) in the thermophilic phase of composting, then sustained decline to 15 OTUs after incubation. There were 10 fungal function groups in the raw swine manure. Pathotroph-saprotroph fungi reached to 15.91% on Day-10 but disappeared on Day-60. Dung saprotroph-undefined saprotroph fungi grown from 0.19% to 52.39% during the treatment. The fungal community had more functional groups but the lower substrate degradation rates in the thermophilic phase. The fungal communities on Day-0 and Day-60 had the highest degradation rates of amino acids and polymers, respectively. Redundancy analysis showed that ORP (49.6%), VS/Ash (45.3%) and moisture (39.2%) were the main influence factors on the succession of fungal community in the swine manure composting process.  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