全文获取类型
收费全文 | 2957篇 |
免费 | 115篇 |
国内免费 | 126篇 |
专业分类
安全科学 | 1985篇 |
废物处理 | 28篇 |
环保管理 | 229篇 |
综合类 | 535篇 |
基础理论 | 98篇 |
环境理论 | 4篇 |
污染及防治 | 93篇 |
评价与监测 | 36篇 |
社会与环境 | 54篇 |
灾害及防治 | 136篇 |
出版年
2024年 | 4篇 |
2023年 | 18篇 |
2022年 | 27篇 |
2021年 | 83篇 |
2020年 | 75篇 |
2019年 | 96篇 |
2018年 | 21篇 |
2017年 | 304篇 |
2016年 | 123篇 |
2015年 | 371篇 |
2014年 | 37篇 |
2013年 | 63篇 |
2012年 | 182篇 |
2011年 | 100篇 |
2010年 | 104篇 |
2009年 | 114篇 |
2008年 | 100篇 |
2007年 | 186篇 |
2006年 | 243篇 |
2005年 | 235篇 |
2004年 | 188篇 |
2003年 | 137篇 |
2002年 | 55篇 |
2001年 | 38篇 |
2000年 | 58篇 |
1999年 | 36篇 |
1998年 | 32篇 |
1997年 | 21篇 |
1996年 | 21篇 |
1995年 | 31篇 |
1994年 | 10篇 |
1993年 | 10篇 |
1992年 | 12篇 |
1991年 | 5篇 |
1990年 | 7篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 5篇 |
1970年 | 1篇 |
排序方式: 共有3198条查询结果,搜索用时 15 毫秒
191.
Ronald A. Chadderton Robert G. Traver Jayaram N. Rao 《Journal of the American Water Resources Association》1992,28(6):1069-1076
ABSTRACT: This paper presents a study which used a standard, hydraulic computer model to generate detailed design information to support conflict analysis of a water resource use issue. As an extension of previous studies, the conflict analysis in this case included several scenarios for stability analysis - all of which reached the conclusion that compromising, shared access to the water resources available would result in the most benefits to society. This expected equilibrium outcome was found to maximize benefit-cost estimates. 相似文献
192.
Neil L. Drobny 《Journal of the American Water Resources Association》1971,7(6):1180-1193
Applications of linear programming to water quality and water quantity problems are discussed, and a fairly comprehensive sample of recent literature in these areas is reviewed. Basic elements of linear programming are also discussed. Emphasis is placed on the elements of linear programming that make it a useful tool for analyzing water resource problems and the basic features of various water resource problems that render them amenable to meaningful analysis by linear programming. 相似文献
193.
Clifford W. Randall Bruce S. Huloher Paul H. King 《Journal of the American Water Resources Association》1970,6(4):648-660
The activated sludge process can remove significant amounts of phosphorus from sewage, but the removal efficiency is usually significantly reduced by the release of phosphate back to solution during subsequent treatment steps. This research presents a study of soluble phosphate release from activated sludge with emphasis on defining the factors that affect such release and the actual release mechanisms. Laboratory units were used for experimental purposes. The experiments were designed to study the relationship between soluble phosphate release and various environmental factors such as redox potential (ORP), dissolved oxygen (DO), pH, solids concentration, solids destruction, and sulfate salt addition. The effect of substrate utilization on phosphate uptake and the relationship between uptake characteristics and subsequent phosphate release were also studied. The results show that some phosphate storage occurs during aerobic substrate utilization. Following substrate utilization, activated sludge phosphate release is directly related to the amount of biological stress the organisms are subjected to, and the mechanism of release is primarily cell lysis. The phosphate released per unit sludge under anoxic conditions is relatively constant. Under normal environmental conditions, neither ORP or pH change have a significant affect on phosphate release. 相似文献
194.
虚拟现实技术在安全工程中的应用 总被引:23,自引:2,他引:21
论述了虚拟现实技术(VirtualReality)的基本原理、应用范围。结合大空间公用建筑火灾虚拟现实系统,提出了安全工程中应用虚拟现实技术的基本结构及程序设计关键技术,给出了大空间公用建筑火灾虚拟现实系统编制实例 相似文献
195.
经济结构变动对环境污染物排放的影响分析 总被引:11,自引:0,他引:11
王海建 《中国人口.资源与环境》1999,9(3):30-33
本文利用投入产出技术给出一类经济结构变动对环境污染物排放的影响分析模型,该方法着重分析了各产业部门的生产技术变动、最终需求变动及收入变动对环境污染物排放量的影响。 相似文献
196.
陈吉余 《长江流域资源与环境》1995,4(2):106-109
探讨了连接上海,崇明和江苏海门的长江河口桥隧工程在连接河口岛屿间交通,发挥崇明的区位优势,促进地区经济发展以及在上海港建设中的作用。详细论述了越江工程完成后上海新港的扩建,根据河口河水岸线的分布,提出了在横沙岛东滩修建人工岛的设想,最后对几种越江方案进行了分析比较,提出了作者的看法。 相似文献
197.
通才式安全工程专业课程设置的探讨 总被引:8,自引:2,他引:6
根据安全工程专业所处的学科结构体系 ,讨论了通才式安全工程专业高等教育课程设置所考虑的因素。提出了通才式安全工程专业高等教育课程的设置思想、专业基础课和主干课的学时比以及实践与理论相结合的实习方法。 相似文献
198.
199.
北京沙尘天气与源地气象条件的关系 总被引:11,自引:0,他引:11
本介绍了影响北京地区沙尘天气的沙尘源地,沙尘暴发生的条件和传输路径,分析了沙尘暴源地的气候要素特征及其对北京地区沙尘天气的影响,说明了北京沙尘天气发生和加剧的原因,影响北京地区沙尘天气的境外源地主要位于哈萨克斯坦,俄罗斯以及蒙古国境内,境内源地主要位于内蒙古和新疆,以及甘肃和青海的部分地区,沙尘天气发生必须具备三个条件:沙源,大风,气流辐合(垂直对流),有沙源不一定起沙,但无沙源一定不起沙,沙尘暴源地的气候特征主要表现为冬季寒冷,夏季炎热,全年降水稀水,影响北京的沙尘传输路径,最主要的有两条,即西路传输和北路传输,北京沙尘天气与沙尘暴源地的春季降水比较结果表明,北京地区沙尘暴和浮尘天气发生次数与沙尘源区春季大气降水量有比较显的负相关关系,北京扬沙天气的发生与沙源区冬春季降水量相关关系不显,说明北京扬沙天气起因与源区降水没有明显的关系,北京扬沙天气主要受本地的自然条件和人为活动的影响。 相似文献
200.
This paper describes a fuzzy hierarchical analytic approach to determine the weighting of subjective judgments. In addition,
it presents a nonadditive fuzzy integral technique to evaluate a green engineering industry case as a fuzzy multicriteria
decision-making (FMCDM) problem. When the investment strategies are evaluated from various aspects, such as economic effectiveness,
technical feasibility, and environmental regulation, it can be regarded as an FMCDM problem. Since stakeholders cannot clearly
estimate each considered criterion in terms of numerical values for the anticipated alternatives/strategies, fuzziness is
considered to be applicable. Consequently, this paper uses triangular fuzzy numbers to establish weights and anticipated achievement
values. By ranking fuzzy weights and fuzzy synthetic utility values, we can determine the relative importance of criteria
and decide the best strategies. This paper applies what is called a λ fuzzy measure and nonadditive fuzzy integral technique
to evaluate the synthetic performance of green engineering strategies for aquatic products processors in Taiwan. In addition,
we demonstrate that the nonadditive fuzzy integral is an effective evaluation and appears to be appropriate, especially when
the criteria are not independent. 相似文献