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   1883篇
  免费   264篇
  国内免费   1080篇
安全科学   90篇
废物处理   200篇
环保管理   197篇
综合类   1640篇
基础理论   441篇
污染及防治   549篇
评价与监测   42篇
社会与环境   60篇
灾害及防治   8篇
  2024年   3篇
  2023年   37篇
  2022年   61篇
  2021年   73篇
  2020年   88篇
  2019年   87篇
  2018年   85篇
  2017年   87篇
  2016年   108篇
  2015年   122篇
  2014年   136篇
  2013年   262篇
  2012年   209篇
  2011年   170篇
  2010年   146篇
  2009年   146篇
  2008年   123篇
  2007年   185篇
  2006年   181篇
  2005年   141篇
  2004年   141篇
  2003年   118篇
  2002年   90篇
  2001年   53篇
  2000年   76篇
  1999年   70篇
  1998年   50篇
  1997年   45篇
  1996年   29篇
  1995年   25篇
  1994年   20篇
  1993年   26篇
  1992年   7篇
  1991年   7篇
  1990年   6篇
  1989年   3篇
  1988年   2篇
  1986年   6篇
  1984年   1篇
  1981年   1篇
  1977年   1篇
排序方式: 共有3227条查询结果,搜索用时 15 毫秒
101.
Anthropogenic environmental impacts can disrupt the sensory environment of animals and affect important processes from mate choice to predator avoidance. Currently, these effects are best understood for auditory and chemosensory modalities, and recent reviews highlight their importance for conservation. We examined how anthropogenic changes to the visual environment (ambient light, transmission, and backgrounds) affect visual communication and camouflage and considered the implications of these effects for conservation. Human changes to the visual environment can increase predation risk by affecting camouflage effectiveness, lead to maladaptive patterns of mate choice, and disrupt mutualistic interactions between pollinators and plants. Implications for conservation are particularly evident for disrupted camouflage due to its tight links with survival. The conservation importance of impaired visual communication is less documented. The effects of anthropogenic changes on visual communication and camouflage may be severe when they affect critical processes such as pollination or species recognition. However, when impaired mate choice does not lead to hybridization, the conservation consequences are less clear. We suggest that the demographic effects of human impacts on visual communication and camouflage will be particularly strong when human‐induced modifications to the visual environment are evolutionarily novel (i.e., very different from natural variation); affected species and populations have low levels of intraspecific (genotypic and phenotypic) variation and behavioral, sensory, or physiological plasticity; and the processes affected are directly related to survival (camouflage), species recognition, or number of offspring produced, rather than offspring quality or attractiveness. Our findings suggest that anthropogenic effects on the visual environment may be of similar importance relative to conservation as anthropogenic effects on other sensory modalities.  相似文献   
102.
以钛酸四正丁酯和石墨为原料,通过水热法制备了锐钛矿型为主的纳米TiO2复合光催化剂(纳米TiO2-石墨烯),并采用XRD,FTIR,FESEM,TEM技术对其进行了表征。通过紫外光照射降解溶液中的罗丹明B(RhB)研究了TiO2-石墨烯的光催化活性,分析了初始罗丹明B质量浓度、催化剂加入量、溶液pH和催化剂使用次数等影响降解效果的因素。实验结果表明:在初始RhB质量浓度为20 mg/L、溶液pH为7.10、催化剂加入量为1.000 g/L的条件下,紫外光照射30 min时,纳米TiO2-石墨烯对RhB的降解率高达98.69%,明显高于纳米TiO2的44.69%;纳米TiO2-石墨烯稳定性较强,可多次重复使用。  相似文献   
103.
This paper explores the notion of environmentally induced spatial stigma through an analysis of data from interviews across public attitudes to pollution within the Asopos river basin in central Greece. The area has a 40 year plus history of legal and illicit industrial waste disposal and public debate on the associated environmental degradation. The study focuses on the perceptions and beliefs of a sector of the community likely to be directly and negatively affected by stigma, that is small business owners in the tourism and hospitality sector. The qualitative analysis explores awareness and viewpoints on environmental degradation and water quality within the local context, implications for the local economy and the individual's own enterprise, views on industrial environmental management as well as corporate responsibility and future prospects for the environmental problems of Asopos. Findings reveal a noticeable variation in views on industrial pollution and ecosystem deterioration among the respondents, but overall a strong environmentally induced stigmatization of the area. They also uncover an information asymmetry and lack of credible commitment by government bodies and industry members in disclosing accurate information, a situation likely to increase speculation and uncertainty within the community. The paper concludes by addressing implications of the findings to policy-making and managerial considerations, along with future research perspectives which aim to increase considerations of sustainability aspects for local development.  相似文献   
104.
Fipronil is a broad-spectrum insecticide that has a good control effect on pests of commercial poultry. Although many studies have reported the environmental fate of fipronil, the influence of residual fipronil in poultry waste on biogas production has not been further explored yet. In this article, an experimental comparative study on anaerobic digestion (AD) of chicken manure (CM) and corn straw (CS) with different fipronil concentrations (FCs) was carried at 8% of total solid (TS) and mid-temperature (35?±?1)°C. The results showed that fipronil had a significant effect on biogas production during AD of CM and CS. When the FC is at a low level (≤10?mg·kg?1), the biogas production rate is increased and the digestion period was shortened, while higher FC (≥ 20?mg·kg?1) showed an inhibitory effect. During the monitoring of enzyme activity, low FC showed no significant effect on cellulase and saccharase, but the urease activity increased in the early stage. High FC showed inhibition of activity of cellulase and urease, but the saccharase activity was significantly inhibited until FC reached 40?mg·kg?1. This study also confirms that the environment in anaerobic digester is favorable for the degradation of fipronil, and its half-life is about 15.83?days.  相似文献   
105.
微生物电化学技术能同时实现污染物去除和能量回收,但存在污染物去除种类有限及产能效率低的局限,近几年将可再生的太阳能引入微生物电化学技术的微生物-光-电化学耦合技术应运而生。本文简要介绍了微生物-光-电化学耦合技术的发展背景和研究现状,对该技术现有的耦合形式进行分类,并对各种形式的耦合机理进行详细的阐释,最后对其未来的发展进行了展望。  相似文献   
106.
周礼  司士辉 《化工环保》2014,34(1):84-89
采用聚合物前驱体法制备了Ti/SnO2-Sb2O3电极,再通过恒电流电沉积法制备了 Ti/SnO2-Sb2O3/PbO2和Ti/SnO2-Sb2O3/MnO2电极。采用SEM技术对3种金属氧化物电极表面的形貌进行了表征,并分别以3种电极为阳极进行了苯酚的电催化氧化实验。实验结果表明:电解时间为2.5 h时,Ti/SnO2-Sb2O3电极、Ti/SnO2-Sb2O3/PbO2电极和Ti/SnO2-Sb2O3/MnO2电极对苯酚的降解率分别为85.9%,83.2%,44.6%;苯酚在3种电极上的电催化氧化反应均遵循一级反应动力学方程;苯酚在Ti/SnO2-Sb2O3 电极和Ti/SnO2-Sb2O3/PbO2电极上的反应速率较快,并具有较高的析氧电位;Ti/SnO2-Sb2O3/PbO2电极具有更好的耐腐蚀性和更长的使用寿命。  相似文献   
107.
李俊杰  丁灯  季东  昝菱 《化工环保》2019,39(4):413-420
在自制反应器内,通过喷射法将纳米TiO_2分散成气溶胶形式,用以降解空气中的芥子气模拟剂二乙基硫醚(DES)。利用自行设计的一套气溶胶沉降行为评价装置,对TiO_2气溶胶的释放条件进行了优化。系统研究了相对湿度、反应温度、光强、催化剂加入量、反应物浓度等因素对DES降解速率和彻底矿化速率的影响。结果表明:TiO_2气溶胶对2.80 mg/L(近似芥子气快速致死浓度)DES降解的半衰期由涂覆型TiO_2的34.5 min缩短至8.5 min;TiO_2气溶胶光催化降解DES的最佳相对湿度为35%,此时CO_2最快生成速率可达34.64μg/(L·min),150 min内彻底矿化比例达66.1%;对于1.5 L反应器,催化剂加入量为30 mg时降解DES的量效比达到最佳状态;TiO_2气溶胶光催化适用于含低浓度DES空气的快速净化。  相似文献   
108.
• PAM degradation in thermophilic AD in comparison with mesophilic AD. • PAM degradation and its impact on thermophilic and mesophilic AD. • Enhanced methane yield in presence of PAM during thermophilic and mesophilic AD. • PAM degradation and microbial community analysis in thermophilic and mesophilic AD. Polyacrylamide (PAM) is generally employed in wastewater treatment processes such as sludge dewatering and therefore exists in the sludge. Furthermore, it degrades slowly and can deteriorate methane yield during anaerobic digestion (AD). The impact or fate of PAM in AD under thermophilic conditions is still unclear. This study mainly focuses on PAM degradation and enhanced methane production from PAM-added sludge during 15 days of thermophilic (55°C) AD compared to mesophilic (35°C) AD. Sludge and PAM dose from 10 to 50 g/kg TSS were used. The results showed that PAM degraded by 76% to 78% with acrylamide (AM) content of 0.2 to 3.3 mg/L in thermophilic AD. However, it degraded only 27% to 30% with AM content of 0.5 to 7.2 mg/L in mesophilic AD. The methane yield was almost 230 to 238.4 mL/g VSS on the 8th day in thermophilic AD but was 115.2 to 128.6 mL/g VSS in mesophilic AD. Mechanism investigation revealed that thermophilic AD with continuous stirring not only enhanced PAM degradation but also boosted the organics release from the sludge with added PAM and gave higher methane yield than mesophilic AD.  相似文献   
109.
MCM-41分子筛负载铁铈催化降解甲基橙   总被引:1,自引:0,他引:1       下载免费PDF全文
采用等体积浸渍法制备了负载型有序介孔Fe-Ce/MCM-41催化剂。研究了该催化剂降解甲基橙的适宜工艺条件,并采用XPS,XRD,TEM技术对该催化剂进行了表征。实验结果表明,该催化剂Fenton氧化降解甲基橙的较适宜工艺条件为:溶液pH 5.0、甲基橙溶液初始质量浓度100 mg/L、催化剂加入量2.0 g/L、H_2O_2浓度20 mmol/L,在此适宜条件下反应120 min时,甲基橙去除率接近100%。表征结果显示:Fe-Ce/MCM-41催化剂主要由铁、铈、氧、碳4种元素组成;铁与铈的摩尔比接近3∶1;铁和铈主要以Fe_3O_4和CeO_2的形态存在于催化剂表面。  相似文献   
110.
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