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161.
半导体行业含氟废水处理的研究   总被引:3,自引:0,他引:3  
在过去几年,中国的半导体工业得到了迅速的发展,同时也带来了新的环境问题,其中尤以含氟废水的危害最为严重。文章详细介绍了某半导体企业含氟废水处理站,包括含氟废水的来源,危害,常用的处理方法,实验情况,本工程采用的工艺流程和运行情况等。实验数据和工程运行情况都证明,pH值为7.5—8.5时,以化学沉淀法和混凝沉淀法处理含氟废水效果最好。实践证明利用强酸强碱调节废水pH值后,采用CaCl2处理含氟废水,具有操作简便和处理费用低等优点,同时针对CaF2沉淀对处理设备的影响提出了有效措施。  相似文献   
162.
内蒙古自治区煤炭储量位居全国首位,同时又属于严重缺水地区,煤化工、盐化工等化工废水零排放为成了热点话题。浓盐水的处理成为制约化工废水零排放的关键技术。介绍了浓盐水的处理技术及存在的问题同时对主要处理技术的投资行进了比较分析。  相似文献   
163.
The use of lead poses significant hazardous occupational exposure to workers in the electronics industry, and also causes environmental challenges at the end of product life. For the past decade, there has been a global effort in the electronics industry to initiate a move towards using lead-free materials for the production of printed circuit boards. However, there are technical and economic challenges, such as long term reliability and rework capability, that remain to hinder the universal implementation of lead-free materials. As a result, many electronics products are still currently manufactured and assembled using materials containing lead.The costs for investigating and evaluating the various lead-free electronics materials and manufacturing processes can be cost prohibitive for an individual company to undertake alone. Consequently, the New England Lead-free Electronics Consortium was formed as a collaborative effort of New England companies spanning the electronics supply chain to help move the industry towards lead-free electronics. The Consortium is a working collaboration of industry, government, and academia. For the past several years, the Consortium has conducted research and testing for using various lead-free materials for the manufacture of printed circuit boards. The Consortium has been successful in identifying lead-free materials and processes to address the challenges of assembly and rework. The Consortium is currently conducting research to address the long-term reliability challenge of lead-free electronics.  相似文献   
164.
Over the past two decades, the combination of molecular and field methods has revealed considerable variation in the level of extrapair fertilizations among socially monogamous birds. Models predicting extrapair young range in scale from a single population to multiple Orders, and there is no single, unifying theory for these reproductive tactics. We investigated proximate explanations of extrapair fertilizations in two subspecies of the swamp sparrow, Melospiza georgiana georgiana and Melospiza georgiana nigrescens, across a range of social and environmental conditions. The presence of extrapair young was best predicted by the size of two male plumage badges (one correlated with parental care and one with territorial aggression) relative to the badge size of their immediate neighbors, the interaction of these two measures, mean territory size, and the maximum size of the aggression badge among neighbors. The size of the male’s parental care badge (relative to neighbors) was negatively correlated with the probability of lost paternity. The relative size of the aggression badge was positively correlated with the presence of extrapair young when the parental care badge was small and negatively correlated when the badge was large. Controlling for these crown measures, males with larger territories were less likely to suffer losses in paternity. There was no effect of breeding density, breeding synchrony, their interaction, subspecies, or weather during the fertile period on the presence of extrapair young. These results suggest that female preference for males that provide more parental care (or preference for genes that convey this trait) plays a dominant role in extrapair interactions among swamp sparrows. Models based on female assessments of relative mate quality offer a promising explanation of patterns in extrapair fertilizations among bird species.  相似文献   
165.
集约化畜禽养殖业的发展在提高人民生活水平的同时也给环境带来了巨大的压力。清洁生产是基于污染预防的一种环境保护的战略措施,它体现了废弃物的减量化、资源化、无害化原则。实施畜禽养殖业清洁生产是保证畜禽养殖业健康可持续发展的根本途径。分析了畜禽养殖业实施清洁生产的必要性.并根据当前畜禽养殖业清洁生产进展中存在的问题,提出了相应的对策。  相似文献   
166.
拉链排咪、塑料制品和印刷行业VOCs排放特征比对分析   总被引:1,自引:0,他引:1  
采用GC-MS法测定拉链排咪、塑料制品、包装印刷行业的生产车间无组织VOCs排放,得到3个工业源VOCs源成分谱。结果表明:不同工业源排放的VOCs组分存在明显差异,拉链排咪以苯系物为主,占比3529%,主要污染物为正己烷、二氯甲烷、甲苯;塑料制品中苯系物占比为4735%,甲苯、乙酸乙酯、正己烷为主要污染物;包装印刷中苯系物质量分数高达6367%,甲苯、1,2,4-三甲苯、丙酮为主要污染物  相似文献   
167.
阐述了当前我国大型危险化工企业危险源监测及预警系统建设的现状与不足,以泰州梅兰集团为例,提出了大型危险化工企业危险源监测及预警系统的建设目标及原则,应急预警处置系统的主要内容、标准与要求。  相似文献   
168.
赵薇 《环境保护科学》2007,33(6):89-90,93
目前沈阳市畜禽养殖污染严重,COD年排放量已达88万t,畜牧业发展过程中的排放物已成为不可忽视的污染源。因此,解决畜牧业环境污染问题已成为沈阳市现阶段环境保护和可持续发展的紧迫任务和重要内容。  相似文献   
169.
In recent decades, intensive techniques of livestock raising have flourished, which has largely replaced traditional farming practices such as transhumance. These changes may have affected scavengers’ behaviour and ecology, as extensive livestock is a key source of carrion. This study evaluates the spatial responses of avian scavengers to the seasonal movements of transhumant herds in south-eastern Spain. We surveyed the abundance of avian scavengers and ungulates, and analysed the factors affecting the space use by 30 GPS-tracked griffon vultures (Gyps fulvus). Griffons’ foraging activity increased in the pasturelands occupied by transhumant herds, which implied greater vulture abundance at the landscape level during the livestock season. In contrast, facultative scavengers were more abundant without transhumant livestock herds, and the abundance of wild ungulates did not change in relation to livestock presence. We conclude that fostering transhumance and other traditional farming systems, to the detriment of farming intensification, could favour vulture conservation.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01668-x.  相似文献   
170.
Females of many cercopithecine primates live in stable dominance hierarchies that create long-term asymmetries among sets of female relatives (matrilines) in access to limiting resources and shelter from psychosocial stress. Rank-related differences in fitness components are widely documented, but their causes are unclear. Predicted breeding values from an animal model for female age of first reproduction are used to discriminate between shared additive genetic and shared environmental effects among the members of matrilines in a population of free-ranging rhesus macaques (Macaca mulatta). While age of first reproduction has a modest heritability (≈0.2), breeding values are distributed in a largely random fashion among matrilines and contribute little to the observed rank-related differences in average age of first reproduction. These results support the long-held, but previously unverified, contention that rank-related life history differences in female cercopithecine primates are the result of environmental rather than genetic differences among them.  相似文献   
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