全文获取类型
收费全文 | 252篇 |
免费 | 13篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 24篇 |
废物处理 | 2篇 |
环保管理 | 77篇 |
综合类 | 89篇 |
基础理论 | 26篇 |
污染及防治 | 14篇 |
评价与监测 | 16篇 |
社会与环境 | 7篇 |
灾害及防治 | 13篇 |
出版年
2023年 | 3篇 |
2021年 | 2篇 |
2020年 | 6篇 |
2019年 | 5篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 11篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 8篇 |
2012年 | 15篇 |
2011年 | 19篇 |
2010年 | 10篇 |
2009年 | 20篇 |
2008年 | 8篇 |
2007年 | 27篇 |
2006年 | 15篇 |
2005年 | 11篇 |
2004年 | 11篇 |
2003年 | 12篇 |
2002年 | 14篇 |
2001年 | 8篇 |
2000年 | 6篇 |
1999年 | 2篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 5篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 2篇 |
排序方式: 共有268条查询结果,搜索用时 328 毫秒
211.
中国能源安全及其资源开发与利用的策略研究 总被引:8,自引:0,他引:8
通过采用“霍夫曼系数”的分析方法,提出能源危机是国家在工业化过程中的必经阶段,并从资源经济理论角度认识我国经济增长对资源消耗的关系,剖析国际能源危机背景与经济格局的成因。中国目前和今后主要受制于国内资源不足,要应对能源危机,只有实现多元化的策略,才能保障能源的供应,实现我国经济社会和谐、稳定、可持续发展。因此,能源资源开发与利用策略的研究具有极其重要的现实意义。 相似文献
212.
快速测定地面水中阴离子表面活性剂 总被引:3,自引:0,他引:3
通过比对实验来探讨用孔雀绿试剂法测定地面水中阴离子表面活性剂的可行性。实验结果证明,该方法精密度与准确性均达到现行监测规范要求,与国标亚甲基蓝分光光度法相比具有操作简单,不用萃取剂,分析时间短的优点,可适用于地面水的监测。 相似文献
213.
David Werner Hrissi K. Karapanagioti Patrick Hhener 《Journal of contaminant hydrology》2009,108(1-2):54-63
A partitioning tracer test based on gas-phase diffusion in the vadose zone yields estimates of the residual nonaqueous phase liquid (NAPL) saturation. The present paper investigates this technique further by studying diffusive tracer breakthrough curves in the vadose zone for a heterogeneous NAPL distribution. Tracer experiments were performed in a lysimeter with a horizontal layer of artificial kerosene embedded in unsaturated sand. Tracer disappearance curves at the injection point and tracer breakthrough curves at some distance from the injection point were measured inside and outside of the NAPL layer. A numerical code was used to generate independent model predictions based on the physicochemical sand, NAPL, and tracer properties. The measured and modeled tracer breakthrough curves were in good agreement confirming the validity of important modeling assumptions such as negligible sorption of chlorofluorocarbon (CFC) tracers to the uncontaminated sand and their fast reversible partitioning between the soil air and the NAPL phase. Subsequently, the model was used to investigate different configurations of NAPL contamination. The experimental and model results show that the tracer disappearance curves of a single-well diffusive partitioning tracer test (DPTT) are dominated by the near-field presence of NAPL around the tip of the soil gas probe. In contrast, breakthrough curves of inter-well tracer tests reflect the NAPL saturation in between the probes, although there is no unique interpretation of the tracer signals if the NAPL distribution is heterogeneous. Numerical modeling is useful for the planning of a DPTT application. Simulations suggest that several cubic meters of soil can be investigated with a single inter-well partitioning tracer test of 24-hour duration by placing the injection point in the center of the investigated soil volume and probes at up to 1 m distance for the monitoring of gaseous tracers. 相似文献
214.
215.
科学地评估中国发展非粮燃料乙醇减排CO2的潜力对于制定应对气候变化措施和燃料乙醇发展政策具有重要的现实意义。论文提出了基于占地属性的燃料乙醇原料划分方法,并指出低质宜耕边际性土地与农作物副产品资源可作为占地型原料的种植空间和非占地型原料的来源。随后,构建了燃料乙醇替代的CO2减排潜力的评估模型,并对2015年和2030年中国发展非粮乙醇的减排潜力进行了评估。评估结果表明,在2015和2030年我国非粮燃料乙醇可产生1 094.7×104 t和4 902.7×104 t的CO2减排潜力,且形成以非占地型原料乙醇为主的减排结构。从减排潜力空间分布上看,我国在2015年和2030年将分别呈现出以微度、低度减排区为主和极高、高度减排区为主、"∏"型的空间结构。 相似文献
216.
西部生态旅游模式的市场研究 总被引:5,自引:0,他引:5
西部地区具有丰富的生态旅游资源,中国名山资源的23%都集中在西部地区,西部少数民族文化旅游资源也极为丰富。我国正在西部实施可持续战略,发展生态旅游模式正顺应了这一战略。作者对在西部建立生态旅游的要素市场、国内外游客市场、资金市场进行了考察研究,并结合西部大开发战赂,论证了生态旅游在西部的市场可行性。 相似文献
217.
石油勘探开发中的石油类污染及其监测分析技术 总被引:15,自引:2,他引:15
首先介绍了陆地石油勘探开发过程对环境的影响 ,并总结出这种影响集中体现在油田附近水体和土壤受到石油类的污染。然后针对石油类监测分析方法展开探讨 ,并分水中石油类和土壤中石油类两部分 ,把我国和美国的监测方法进行了对比研究。在此基础上提出了在进行油田环境现状评价和石油类污染物环境变迁规律研究中使用石油类分析方法的建议 相似文献
218.
219.
There has been considerable public interest regarding the toxicity of chemicals used in hydraulic fracturing, but little is known about its sister technique, acidizing. Little to no research has been done on what the chemicals of acidization are and what impact they could have on humans and the environment. This paper discusses the differences between three acidizing techniques (acid maintenance, matrix acidization, and acid fracturing) and quantifies the amounts of the chemicals used for each. Washington State's Quick Chemical Assessment Tool is used to identify F-graded toxins, which are known carcinogens, mutagens, reproductive toxins, developmental toxins, endocrine disruptors, or high acute toxicity chemicals. The analysis of the present data shows that there have been over 600 instances of acidizing in urbanized Southern and Central California from April 2013 to August 2015. Although most of the chemicals of acidizing are similar to hydraulic fracturing, those used most frequently are different. There are close to 200 specific chemicals used in acidization, with at least 28 of them being F-graded hazardous chemicals. Some are used frequently in the range of 100–1000 kg per treatment, such as hydrofluoric acid, xylene, diethylene glycol, and ethyl benzene. Close to 90 more chemicals are identified using non-specific names as trade secrets or reported with no quantity. Unlike hydraulic fracturing the chemical concentrations in acidizing are high, ranging from 6% to 18%, and the waste returns can be highly acidic, in the range of pH 0–3. With this paper it is hoped that acidization becomes part of the larger discussion on concerns with oil exploration and be evaluated by appropriate authorities. 相似文献
220.
石油和天然气是国民经济运行与发展的“血液”,但出于种种原因,我国目前尚未出台专门规范整个油气行业领域的《石油天然气法》,只有一些位阶较低、效力有限的行政性规章与政策。通过研究美国石油天然气法律的具体制度安排,结合我国油气资源的现行制度与政策,为我国油气资源法律制度的完善提出建议。 相似文献