全文获取类型
收费全文 | 602篇 |
免费 | 68篇 |
国内免费 | 324篇 |
专业分类
安全科学 | 97篇 |
废物处理 | 25篇 |
环保管理 | 78篇 |
综合类 | 532篇 |
基础理论 | 71篇 |
污染及防治 | 165篇 |
评价与监测 | 11篇 |
社会与环境 | 12篇 |
灾害及防治 | 3篇 |
出版年
2024年 | 1篇 |
2023年 | 19篇 |
2022年 | 22篇 |
2021年 | 35篇 |
2020年 | 28篇 |
2019年 | 27篇 |
2018年 | 24篇 |
2017年 | 43篇 |
2016年 | 47篇 |
2015年 | 54篇 |
2014年 | 58篇 |
2013年 | 40篇 |
2012年 | 58篇 |
2011年 | 54篇 |
2010年 | 45篇 |
2009年 | 51篇 |
2008年 | 41篇 |
2007年 | 49篇 |
2006年 | 58篇 |
2005年 | 44篇 |
2004年 | 28篇 |
2003年 | 26篇 |
2002年 | 21篇 |
2001年 | 26篇 |
2000年 | 19篇 |
1999年 | 13篇 |
1998年 | 13篇 |
1997年 | 13篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1978年 | 2篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1970年 | 1篇 |
排序方式: 共有994条查询结果,搜索用时 15 毫秒
111.
Zhuang Yahui Zhang Hongxun Wang Xiaoke & Fang JinyunResearch Center for Eco-Environmental Sciences 《中国人口.资源与环境(英文版)》2004,2(2)
This report summarizes the surveys on carbon inventories and initiatives on sustainable carbon cycling taken by RCEES. The first part of this report deals with the concept of sustainable carbon cycling, the historical evolution of carbon cycling processes in China, carbon pool enhancement, value addition, carbon sequestration and carbon balance. The second part covers the modeling of carbon dynamics, emission inventories of various carbon containing greenhouse gases and their potential abatement measures. 相似文献
112.
113.
结合砂尘的产生和运动机理,对砂尘试验箱的设计原理和应用特点进行了说明,着重对吹砂程中空气的温度和湿度、砂尘颗粒直径比例进行了分析,对气固两相流中颗粒浓度的均匀性进行了探讨。基于砂尘的运动特性,国内应用较普遍采用的闭式循环吹砂试验设备,无法实现砂的有效分离,导致吹砂试验箱试验过程中颗粒直径比例不满足GJB 150.12A要求。在MIL-STD-810H中,已经取消了对吹砂试验相对湿度≤30%的要求。基于吹尘和吹砂引起的不同环境效应,结合吹尘和吹砂试验设备原理和国内已有设备的现状,对现有试验方法和校准规范的完善、砂尘试验箱的改进设计提出了建议和意见。同时文中也介绍了国外开式、闭式循环、可变循环等几种不同类型的砂尘试验箱作为参考,基于砂尘试验的破坏机理提出了砂尘试验箱的分类和选型建议。 相似文献
114.
海上石油泄漏常规的处理方法是原位燃烧,加速其燃烧并使其燃尽是降低其对生态环境影响的重要措施之一。以正庚烷为燃料,在油池内插入竖直铝板,研究不同高度铝板对池火燃烧行为的影响。结果表明,插板对池火燃烧速率以及火焰高度具有明显的增强作用,随着板的高度的增加,增强作用先增大后减小,当H_p/D(板高与油池直径之比)为3.5时,增强作用最大。火焰高度、板的温度、热通量以及燃烧速率的变化趋势一致,它们的临界点均在H_p/D=3.5附近。插板后燃烧速率增大主要是因为插板自身的热传导导致了燃料的核态沸腾,使燃料接受的热反馈增大,从而加快了燃料的蒸发,增大了燃烧速率。 相似文献
115.
人工曝气复氧整治污染河流 总被引:16,自引:0,他引:16
向受到严重有机污染的河流充入溶解氧可以有效消除水体的黑臭,改善水质和恢复生态平衡。文章总结了纯氧增氧系统、鼓风机———微孔布气管曝气系统、叶轮吸气推流式曝气器和水下射流曝气设备等多种使用于河道人工曝气复氧的技术;并列举大量国内外的相关工程实例说明这些技术在实践中的有效性。 相似文献
116.
Common pool resources often insure individual livelihoods against the collapse of private endeavors. When endeavors based on private and common pool resources are interconnected, investment in one can put the other at risk. We model Senegalese pastoralists who choose whether to grow crops, a private activity, or raise livestock on common pool pastureland. Livestock can increase the likelihood of locust outbreaks via ecological processes related to grassland degradation. Locust outbreaks damage crops, but not livestock, which are used for savings and insurance. We show the incentive to self-protect (reduce grazing pressure) or self-insure (increase livestock levels) changes with various property rights schemes and levels of ecological detail. If the common pool nature of insurance exacerbates the ecological externality even fully-informed individuals may make risk management decisions that increase the probability of catastrophe, creating an “insurance trap.” 相似文献
117.
The flash point temperature of Tri-n-butyl phosphate(TBP) and Tri-iso-amyl phosphate(TiAP) in n-dodecane binary mixture has been measured for the entire concentration range using the continuously closed cup flash point apparatus based on the ASTM D6450 method. The flash point was predicted using the UNIFAC group contribution model. The measured flash point was also compared with the prediction from the NRTL, UNIQUAC and Ideal solution models. The UNIFAC model is able to predict the flash point fairly well for the TBP–dodecane mixture and for TiAP–dodecane mixture no improvements is obtained over the ideal solution assumption. The flash point shows positive deviation from ideal solution behavior for both the binary mixture. 相似文献
118.
悬挂链曝气技术应用于河流污染治理 总被引:7,自引:0,他引:7
王涛 《城市环境与城市生态》2003,16(5):16-18
在介绍了悬挂链曝气技术的特点和在复氧曝气方面的适用性的基础上,对该技术的局限性进行了阐述,并认为悬挂链技术为河流污染治理提供了一种新选择。 相似文献
119.
M. A. C. Veer 《Journal of Coastal Conservation》1997,3(1):41-48
The encroachment of some tall grass species in open dune vegetation, as observed in a Dutch dry dune area, is considered unfavourable
from a conservation viewpoint. This paper investigates differences in vegetation and soil properties between grass-dominated
and still existing open dune grassland plots at four locations along the coast. Soil properties studied include nitrogen and
phosphorus pools and nitrogen availability by mineralization. Vegetation properties included are above and below-ground biomass
and nitrogen and phosphorus concentrations in above-ground biomass.
Systematic differences in N-pools between grass-dominated and open dune grassland plots were not observed. However, N-availability
by mineralization and its turnover rates are higher in grass-dominated plots than in open dune grassland plots, as well as
above and below-ground biomass. In open dune grassland plots, atmospheric N-input is an important source of N, whereas in
grass-dominated plots mineralization largely exceeds atmospheric N-input. However, these observations do not explain the mosaic-like
vegetation pattern. Grazing intensity is most likely the determinant factor in the dry dune system. It is concluded, that
grass encroachment is probably triggered by atmospheric deposition and is enhanced by positive feedbacks in the N-cycle. The
relevance of these results for restoration management is briefly discussed. 相似文献
120.