全文获取类型
收费全文 | 548篇 |
免费 | 24篇 |
国内免费 | 35篇 |
专业分类
安全科学 | 39篇 |
废物处理 | 21篇 |
环保管理 | 80篇 |
综合类 | 118篇 |
基础理论 | 115篇 |
环境理论 | 2篇 |
污染及防治 | 155篇 |
评价与监测 | 32篇 |
社会与环境 | 38篇 |
灾害及防治 | 7篇 |
出版年
2023年 | 11篇 |
2022年 | 23篇 |
2021年 | 21篇 |
2020年 | 10篇 |
2019年 | 24篇 |
2018年 | 25篇 |
2017年 | 23篇 |
2016年 | 33篇 |
2015年 | 26篇 |
2014年 | 34篇 |
2013年 | 51篇 |
2012年 | 22篇 |
2011年 | 39篇 |
2010年 | 29篇 |
2009年 | 23篇 |
2008年 | 27篇 |
2007年 | 20篇 |
2006年 | 21篇 |
2005年 | 16篇 |
2004年 | 13篇 |
2003年 | 17篇 |
2002年 | 19篇 |
2001年 | 15篇 |
2000年 | 16篇 |
1999年 | 6篇 |
1998年 | 8篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1982年 | 1篇 |
1979年 | 2篇 |
1973年 | 1篇 |
1966年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有607条查询结果,搜索用时 984 毫秒
321.
This article describes the feasibility of researchinto the relation between values of farmers andsustainability for the Dutch Ministry of Agricultureand the Dutch Federation of Agricultural andHorticultural Organisations.Firstly, a theoretical framework describes differentlevels of motivation behind conduct and choices. Itenables exploration and analysis of individualinterviews with small groups of conventional andecological farmers. The aim is to find out what theirbasic convictions regarding nature and sustainabilityare, and to analyze the relation between theseconvictions and the actual choices they make in theirfarming practice. The research shows that for somefarmers, differences in farming practice go back to themotivation level of moral convictions about what is`good farming'. For others, the motivations for aspecific farming practice are more pragmatic or`superficial'. This knowledge can be of significancefor the process of policy making.Secondly, this research demonstrates thatinvestigation into the relation between values andbehavioral choices is possible. The analysis ofinterviews among a small group of farmers gives anidea of the importance of personal values in additionto (and sometimes of more importance than) economicconsiderations. Due to the restricted size of theresearch population, however, these conclusions are oflimited generalizability. Finally, in order to make alarger research agenda possible, the research methodology isevaluated on the basis of scientific criteria. 相似文献
322.
Ben Mepham 《Journal of Agricultural and Environmental Ethics》2000,13(1):65-78
If respect for the dignity ofnon-human creatures is to be an element of publicpolicy it needs, as a first step, to be assimilatedinto the common morality. It is suggested that suchrespect may be based on several philosophicalpremises. Limiting the discussion to sentient animals,the paper reviews three of these: the concept ofanimal telos; the application of Rawlsiancontractarianism to the case of non-human animals asmoral patients; and human attitudes to animals in thelight of virtue theory. Consideration is then given tothe extent to which, by accommodating respect for thedignity of animals within the common morality, theseprinciples might find more substantive expression inpublic policy. 相似文献
323.
采用微卫星分子标记技术对海南近海点带石斑鱼野生和养殖群体的遗传变异进行了研究.实验所用点带石斑鱼分别于2005年6月和9月取自海南万宁石斑鱼养殖基地和三亚近海,均为20尾,取全血以酚-氯仿抽提方法提取基因组DNA,利用微卫星引物进行PCR扩增,反应产物经8%非变性聚丙烯酰胺凝胶电泳分离、银染显色,并计算了相应的遗传学参数.结果表明,在野生和养殖群体中, 7个基因座位的等位基因平均数(A)分别为3.29和3.29,每个基因座位有效等位基因数(ae)分别为1.90~3.68和1.83~4.06,野生和养殖群体平均杂合度(Ho)分别为0.790 4和0.833 7;两个群体间的遗传相似性系数为0.832 5,遗传距离为0.183 4.由此可知,点带石斑鱼野生群体的等位基因数、平均有效等位基因数等于养殖群体,而杂合度两群体相当(P=0.637>0.05),说明海南近海点带石斑鱼野生和养殖群体的种质资源较好. 相似文献
324.
针对手烧锅炉的烟尘特性,开发了一种新型湿式除尘器。运行测试结果表明,该装置能够有效地净化手烧燃煤锅炉的烟尘,避免除尘废水的二次污染。 相似文献
325.
Boughariou Emna Allouche Nabila Ben Brahim Fatma Nasri Ghada Bouri Salem 《Environment, Development and Sustainability》2021,23(10):14749-14774
Environment, Development and Sustainability - Groundwater in semiarid regions is of extreme importance due to limited water resources and increasing population demand. Hence, a better knowledge of... 相似文献
326.
Tunisia has very limited potential of surface and groundwater resources which are subject to different quantitative and qualitative forms of degradation. The risk of groundwater pollution results from the interaction between the vulnerability of aquifers to pollution and anthropogenic activities. Our research focuses on the study of the Sers water table water quality (northwest Tunisia) following the inputs used for agricultural activities in the region. Water samples were extracted from 40 wells to analyze the main physicochemical parameter indicators of the groundwater quality. The results obtained show that these waters have two major facies: Na-Cl and Ca-Mg-SO4. The nitrate contents are relatively high suggesting that the agricultural activities are probably the most important anthropogenic source of water contamination. The results of the Standardized Principal Component Analysis (SPCA) confirm the geochemical methods and results and provide further information about the water quality of the Sers El Kef aquifer. In addition, the pollution degree differs from one site to another depending on the spreading rate of nitrogen fertilizers and the distance from the pollution source. 相似文献
327.
Ait-Mouheb Nassim Bahri Akiça Thayer Bechir Ben Benyahia Boumediene Bourrié Guilhem Cherki Brahim Condom Nicolas Declercq Rémi Gunes Adem Héran Marc Kitir Nurgul Molle Bruno Patureau Dominique Pollice Alfieri Rapaport Alain Renault Pierre Riahi Khalifa Romagny Bruno Sari Tewfik Sinfort Carole Steyer Jean-Philippe Talozi Samer Topcuoglu Bulent Turan Metin Wéry Nathalie Yıldırım Ertan Harmand Jérôme 《Regional Environmental Change》2018,18(3):693-705
Regional Environmental Change - Climate change and a growing population around the Mediterranean Rim are increasing the need for water and, consequently, the pressure on resources in terms of both... 相似文献
328.
Benáková Martina Ahmadi Hassan Dučaiová Zuzana Tylová Edita Clemens Stephan Tůma Jiří 《Environmental science and pollution research international》2017,24(25):20705-20716
Environmental Science and Pollution Research - Clarifying the connection between metal exposure and anatomical changes represents an important challenge for a better understanding of plant... 相似文献
329.
上海郊区农田,林地,湿地(池塘)三类典型生境是两栖类最主要的栖息地,生境的差异以及两栖类生态特征的不同造成了两栖类在分布上的差异。2014年和2016年5~8月对上海郊区三类典型生境的30个研究样点两栖类生物多样性进行调查,并运用单因素方差分析对三类生境的两栖类群落结构进行比较,通过层次聚类法分析不同生境的两栖类组成相似性。结果显示:(1)两年间共记录到上海郊区两栖类动物1目4科4属5种5 397只,其中泽陆蛙(Fejervarya multistriata),金线侧褶蛙(Pelophylax plancyi)为优势种。黑斑侧褶蛙(Pelophylax nigromaculata),中华蟾蜍(Bufo gargarizans),饰纹姬蛙(Microhyla fissipes)为常见种。这5种两栖类都为广型分布种。(2)三类生境的两栖类物种丰富度无显著性差异,而两栖类多度差异显著。(3)泽陆蛙,饰纹姬蛙的种群密度在三类生境中差异显著,且在农田生境中最高。黑斑侧褶蛙,金线侧褶蛙的种群密度在三类生境中差异显著且在池塘生境中最高。中华蟾蜍在三类生境中的种群密度无显著性差异。(4)聚类结果为30个研究样点中林地生境与池塘生境被聚为一类,农田生境被单独聚为一类。建议通过对不同生境的保护与恢复达到对上海郊区两栖类生物多样性保护的目的。 相似文献
330.
Héctor Miguel Aviña Jiménez Gabriel León de los Santos Miguel Ángel Benítez Torreblanca 《International Journal of Sustainable Engineering》2017,10(2):90-98
In this article, the comparison of the energetic performance of a binary cycle and a modified binary cycle with flash evaporation is presented, both using a low-enthalpy geothermal resource. The comparative analysis is based on two main discourses: the first one evaluates a conventional binary cycle (CBC) with isopentane as working fluid in order to validate and compare the generated data with those reported in similar studies; the second one uses the same input parameters for both cycles, obtaining the cases in which the modified binary cycle is the most viable choice to use. In addition to the above, several aspects are considered when selecting the most suitable working fluid, and the use of water as working fluid is introduced. When the temperature of the geothermal resource is below 140 °C, and the ambient temperature is 25 °C, the flash evaporation binary cycle, using water as working fluid, shows an improved performance compared to a CBC, with a theoretical output over 1000 kWe. This may encourage new areas of opportunity for power generation, not only with low- and medium-enthalpy geothermal energy, but also with other renewable energy sources such as solar. 相似文献