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   711篇
  免费   21篇
  国内免费   88篇
安全科学   105篇
废物处理   19篇
环保管理   73篇
综合类   308篇
基础理论   88篇
污染及防治   131篇
评价与监测   83篇
社会与环境   8篇
灾害及防治   5篇
  2024年   1篇
  2023年   11篇
  2022年   18篇
  2021年   31篇
  2020年   48篇
  2019年   13篇
  2018年   17篇
  2017年   13篇
  2016年   21篇
  2015年   26篇
  2014年   37篇
  2013年   37篇
  2012年   30篇
  2011年   40篇
  2010年   24篇
  2009年   58篇
  2008年   57篇
  2007年   45篇
  2006年   42篇
  2005年   25篇
  2004年   23篇
  2003年   31篇
  2002年   23篇
  2001年   23篇
  2000年   26篇
  1999年   19篇
  1998年   17篇
  1997年   15篇
  1996年   13篇
  1995年   9篇
  1994年   6篇
  1993年   6篇
  1992年   6篇
  1990年   3篇
  1989年   1篇
  1987年   1篇
  1986年   1篇
  1983年   1篇
  1982年   1篇
  1968年   1篇
排序方式: 共有820条查询结果,搜索用时 15 毫秒
91.
The impact of air masses motion on marine aerosol properties was investigated using an on-board single particle mass spectrometer(SPAMS) deployed for the determination of single particle size resolved chemical composition over Southeast China Sea. Two aerosol blooms(E1 and E2) were observed during the cruise. High average particle number count occurred in E1(7320), followed by E2(5850), which was more than 100–150 times of the average particle number count during normal periods. Particles were classified as four major sources, including continental source, shipping source, marine source, and transport source based on the mass spectral similarity. Transport source was identified as those particles with high particle number count occurred only during aerosol bloom period. Three sub-types of EC-Ca, OC-Ca, and Al-rich were classified as transport source.EC-Ca was the dominant particles of the transport source, accounting for more than 70%of the total particles in aerosol bloom events. A uni-modal size distribution in the size range of 0.1–2.0 μm was observed during normal period, while a bimodal distribution with a tiny mode(0.3 μm) and a coarse mode between 0.4 and 0.6 μm was present during aerosol bloom. The variation of aerosol source is consistent with air masses back trajectories, for the reason that most of the long-range air trajectories are from the ocean,while short air trajectories originate in the continental regions, which means that air masses have a significant impact on the aerosol physical–chemical properties along their tracks.  相似文献   
92.
动态膜压法测定江、污混合水体中有机物含量的探讨   总被引:3,自引:1,他引:2  
用双驱动动态膜压仪测定江、污混合水中有机物含量。通过测定白龙港污水和长江水混合后的膜压和滞回环面积,用它们与相应的经典法CODCr作图,获得了滞回环面积和CODCr之间良好地线性关系,表明用动态膜压法可快速测定混合水中的有机物含量,不须加任何试剂,不会产生二次污染。同时,对实验结果进行了初步的机理探讨。  相似文献   
93.
Sexual selection by competition for mates is a formidable force that has led to extraordinary adaptations in males. Here we present results suggesting a novel case of pheromone mimicry in males of Lariophagus distinguendus, a parasitic wasp of beetle larvae that develop in stored grain. Females of L. distinguendus produce a pheromone even before they emerge from a grain. Males are attracted to the parasitised grain and wait for females to emerge. Males emerging later than others are under enormous selection pressure since females mate only once. We show evidence that developing males fool their earlier emerging competitors by mimicking the female pheromone. Males exposed to pupae of either sex exhibit typical courtship behaviour. Searching males are not only arrested by grains containing developing females but spend as much time on grains containing developing males. Hence, by distracting their competitors away from receptive females late males may increase their own chance to mate with these females. After emergence, males decompose the active compounds within 32 h probably to decrease molestation during their own search for mates. Chemical analyses of active pheromone extracts and bioassays using fractions demonstrate that the active compounds are among the cuticular hydrocarbons.  相似文献   
94.
Wastewater management in small and medium-sized enterprises representing the chemical and food industries was investigated. The results showed that wastewater discharged from an ink-production factory was highly contaminated with organic pollutants. Anaerobic biological treatment followed by chemical coagulation using ferric chloride aided with lime proved to be very effective and produced an effluent that complied with national regulatory standard for wastewater discharge into public sewage network. Also, management of wastewater from a confectionery factory representing the food sector was carried out. Aerobic biological treatment using plastic-packed trickling filter proved to be an effective treatment method. However, application of in-plant control measures alleviated the requirement for the construction of a wastewater treatment plant. The applied pollution prevention and cleaner production measures involved good housekeeping, recovery of spent chocolate, modification of floor cleaning and installation of suction devices for the removal of sugar and starch powders. All improvement measures were documented by cost/benefit analysis.  相似文献   
95.
Impacts on industry of Europe's emerging chemicals policy REACh   总被引:1,自引:0,他引:1  
For Europe, a new regime in chemicals regulation is about to start. After the proposal of the European Commission concerning the Registration, Evaluation and Authorization of Chemicals (REACh) passed its readings in the European Parliament and some differences with the European Council of Ministers were resolved, the regulation will come into force in June 2007. This paper is focused on the question how serious the cost burdens for industry induced by REACh will be, and whether the New European Member States (NMS) which joined the European Union in May 2004 will be able to cope with the regulation. This evaluation has been done by assessing the legislative, administrative and economic framework in New Member States and by analysing real business cases in companies. The empirical showcase business impact studies are at the same time of interest for companies of EU-15 states, other European countries who may implement the regulation, and even for exporters of raw materials and chemicals outside Europe, who will also have to comply with REACh if they market in the European Community. The results give no indications that REACh adoption will bring significant drawbacks to companies in the NMS. The emerging regulation will bring challenges for individual companies, especially for small and medium-sized ones, but for the European chemical industry as a whole, there is no question that it will be able to cope with REACh burdens without losing its global competitiveness.  相似文献   
96.
Dyestuffresidue, a type of hazardous waste, is incinerated in the tubular furnace, and thermodynamic equilibrium model is used to calculate and analyze the chlorine behavior. The HCI emission and its effects on the behaviors of heavy metals are studied. Meanwhile, the effects of three dechlorine reagents are predicted at a high temperature. Results show that HCI emission is dependent on incineration temperature. The HCl evaporated mainly derives from the organic chlorine. Under the working condition of 500-- 900℃, the main products of rig, Pb, Cu, Ni, Zn, and Mn in reaction with HCl are HgCl2 (g), PbCl4(g), PbCI2 (g), (CuCl)3 (g), NiCl2 (s), NiCl2 (g), ZnCl2 (s), ZnCl2 (g), Zn (g), MnCl2 (s), and MnCl2 (g), respectively. Among the three dechlorine reagents, CaCO3 is optimal to remove chlorine at high temperature, little of HCl is released below 800℃, whereas Fe3O4 is unstable at high temperature.  相似文献   
97.
The pure decomposition behavior of 2,2′-azobis (isobutyronitrile) (AIBN) and its physical phase transformation were examined and discussed. The thermal decomposition of this self-reactive azo compound was explored using differential scanning calorimetry (DSC) to elucidate the stages in the progress of this chemical reaction. DSC was used to predict the kinetic and process safety parameters, such as self-accelerating decomposition temperature (SADT), time to maximum reaction rate under adiabatic conditions (TMRad), and apparent activation energy (Ea), under isothermal and adiabatic conditions with thermal analysis models. Moreover, vent sizing package 2 (VSP2) was applied to examine the runaway reaction combined with simulation and experiments for thermal hazard assessment of AIBN. A thorough understanding of this reaction process can identify AIBN as a hazardous and vulnerable chemical during upset situations. The sublimation and melting of AIBN near its apparent onset decomposition temperature contributed to the initial steps of the reaction and explained the exothermic attributes of the peaks observed in the calorimetric investigation.  相似文献   
98.
陈珊珊  蒋勇  邱榕 《火灾科学》2012,21(3):137-146
建立了基于重要性分析的详细化学机理分析平台,利用耦合组分化学存活时间和敏感性系数的重要性参数,确定详细机理中的准稳态组分,通过移除这些组分及其相关反应,得到了计算精度较高的框架机理。针对目前燃烧学界较为关注的混合燃烧问题,以甲烷、乙烯这两种典型低碳碳氢燃料为研究对象,对其详细化学反应机理进行了分析,利用重要性分析法构筑框架机理,并对甲烷/空气和甲烷/乙烯/空气预混火焰进行了数值计算。与详细机理相比,框架机理所涉及的组分数与基元反应数都得到了大幅度的降低,计算时间明显减少,但对火焰温度及反应物、生成物、中间组分浓度的预测与采用详细机理得到的结果吻合良好,证明了重要性分析法的有效性与可靠性。  相似文献   
99.
Chemical industry park plays an important role in optimizing the allocation of resources, but an emergency may make a great deal of personnel casualty and property loss. Many casualties are not the result of accidents but are caused by extreme behavior because of the non-adaptive psychology of the evacuees. Panic is one of the non-adaptive psychological behaviors during an evacuation, which is influenced by a variety of factors. Based on the consideration of the disaster environment and the evolution of crowd emotion, a system dynamics model of panic spread is established by using Anylogic software, and simulation experiments are carried out for different disaster severity, visibility, and groups. The results show that the number of people with severe panic increase when visibility decreases or disaster diffuses. Besides, the appropriate proportion of groups can effectively reduce the cooling time of crowd and ease the fears. However, continue to increase the number of groups has no significant effect on the panic control. This work can provide some reasonable guidance for regional emergency evacuation in chemical park.  相似文献   
100.
Dissatisfaction with the responses of the responsible corporation, Union Carbide, and the Indian government to Bhopal resulted in a campaign by national and international NGOs (non-governmental organisations) over the past three decades. While initially the Indian and international campaigns were separate, over time greater international cooperation took place. In the immediate aftermath of the disaster local NGOs prioritised health, justice and rehabilitation issues, while international NGOs used Bhopal to question chemical industry process and environmental safety in their own countries, as well as internationally. Indian NGOs called on international NGO resources to gain legitimacy for their campaign, to use NGOs as proxies and to extend the geographical scope of the campaign, while international NGOs used Bhopal as an example to advance NGOs analyses and policies. Over the period of the campaign, Indian NGOs became more sophisticated in their campaigning. The international campaign has increasingly become an online campaign, involved in an image or reputational war with Dow Chemical, which took over Union Carbide, while the original campaign issues of justice and reparations over the process safety disaster were joined by similar issues related to environmental safety of abandoned toxic waste.  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