全文获取类型
收费全文 | 283篇 |
免费 | 8篇 |
国内免费 | 119篇 |
专业分类
安全科学 | 13篇 |
废物处理 | 26篇 |
环保管理 | 13篇 |
综合类 | 152篇 |
基础理论 | 59篇 |
污染及防治 | 115篇 |
评价与监测 | 6篇 |
社会与环境 | 15篇 |
灾害及防治 | 11篇 |
出版年
2023年 | 11篇 |
2022年 | 8篇 |
2021年 | 9篇 |
2020年 | 11篇 |
2019年 | 8篇 |
2018年 | 11篇 |
2017年 | 21篇 |
2016年 | 20篇 |
2015年 | 9篇 |
2014年 | 31篇 |
2013年 | 28篇 |
2012年 | 30篇 |
2011年 | 28篇 |
2010年 | 17篇 |
2009年 | 19篇 |
2008年 | 22篇 |
2007年 | 23篇 |
2006年 | 13篇 |
2005年 | 11篇 |
2004年 | 6篇 |
2003年 | 4篇 |
2002年 | 7篇 |
2001年 | 10篇 |
2000年 | 7篇 |
1999年 | 9篇 |
1998年 | 11篇 |
1997年 | 4篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1994年 | 6篇 |
1993年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有410条查询结果,搜索用时 828 毫秒
111.
Pei-wen Zheng Jian-bing Wang Zhen-yu Zhang Peng Shen Peng-fei Chai Die Li Ming-juan Jin Meng-Ling Tang Huai-chu Lu Hong-bo Lin Kun Chen 《Environmental science and pollution research international》2017,24(23):18860-18869
Acute upper and lower respiratory infections are main causes of mortality and morbidity in children. Air pollution has been recognized as an important contributor to development and exacerbation of respiratory infections. However, few studies are available in China. In this study, we investigated the short-term effect of air pollution on hospital visits for acute upper and lower respiratory infections among children under 15 years in Ningbo, China. Poisson generalized models were used to estimate the associations between air pollution and hospital visits for acute upper and lower respiratory infections adjusted for temporal, seasonal, and meteorological effects. We found that four pollutants (PM2.5, PM10, NO2, and SO2) were significantly associated with hospital visits for acute upper and lower respiratory infections. The effect estimates for acute upper respiratory infections tended to be higher (PM2.5 ER = 3.46, 95% CI 2.18, 4.76; PM10 ER = 2.81, 95% CI 1.93, 3.69; NO2 ER = 11.27, 95% CI 8.70, 13.89; SO2 ER = 15.17, 95% CI 11.29, 19.19). Significant associations for gaseous pollutants (NO2 and SO2) were observed after adjustment for particular matter. Stronger associations were observed among older children and in the cold period. Our study suggested that short-term exposure to outdoor air pollution was associated with hospital visits for acute upper and lower respiratory infections in Ningbo. 相似文献
112.
为研究深基坑开挖对邻近建筑物的影响特征并评价其安全性,以厦门市某车站深基坑工程为例,通过构建三维有限元模型,考虑土体小应变刚度行为以及基坑-地基-基础-上部结构共同作用,计算基坑开挖引起邻近建筑物的变形值,并将柱底支座变位作为上部结构的强迫位移施加到上部结构上,然后进行结构内力分析和构件配筋验算,评价邻近建筑物的安全。研究表明:邻近建筑物越靠近基坑部分受基坑开挖影响越大,基坑开挖后,邻近建筑物结构变形主要表现为沉降和指向基坑的水平位移,结构最大水平位移为6.6 mm,自顶部向下逐渐减小,即结构发生微量倾斜;邻近建筑物地下室以沉降变形为主,主要受影响区域约为基坑围护墙后3倍的基坑开挖深度范围,沉降急剧变化区域约为1.5倍基坑开挖深度范围,地下室最大沉降为15.9 mm;受到邻近基坑开挖影响,上部结构虽然因支座变位产生内力重分布,但经检算认为整个结构仍然安全可靠。 相似文献
113.
114.
苯胺在水体悬浮颗粒物上吸附特征 总被引:5,自引:0,他引:5
通过批量平衡法实验,比较了作为有机碱离子化有机污染物之一的苯胺在酸性、天然水和碱性水体中悬浮颗粒物上的吸附特征,并观察了水体颗粒物中腐殖酸含量对苯胺吸附行为的影响。结果表明,苯胺在水体悬浮颗粒物上的吸附遵守Fre-undlich方程:在pH5—10范围内苯胺被吸附的能力随介质pH值和颗粒物中有机质含量的升高而增大. 相似文献
115.
116.
117.
118.
采用清罐含油污泥资源化综合利用技术,处理后的含油污泥经检测其灰渣重金属含量均小于我国GB 15618-1995《土壤环境质量标准》和GB 4284-84《农用污泥中污染物控制标准》,灰渣浸出液达到GB5085.3-2007《危险废物鉴别标准浸出毒性鉴别》二级标准、燃烧后产生的废气和烟尘达到GB 13271-2001《锅炉大气污染物排放标准》。解决了清罐油泥处理难的问题,同时符合国家推行清洁生产,大力发展循环经济的要求,使生产过程中的废物减量化、资源化、无害化,减小了油泥排污费用,具有显著环境效益和社会效益。 相似文献
119.
Wan-Lan Chai Jing-Dong Chow Chien-Chung Chen Fu-Sheng Chuang Wei-Chuan Lu 《Journal of Polymers and the Environment》2009,17(2):71-82
Polyvinyl alcohol (PVA) and starch are both biodegradable polymers. These two polymers can be prepared as biodegradable plastics
that are emerging as one of the environmental friendly materials available now. In this study, after reacting with sodium
trimetaphosphate (STMP), modified corn starch was blended with PVA in different ratios by a barbender. Test samples were prepared
for mechanical and thermal properties measurements. The surface roughness and morphology of fractured surface of the samples
were observed by an atomic force microscopy (AFM) and scanning electron microscope (SEM) measurements. Aqueous degradation
by enzyme, water absorption and biodegradability behavior were evaluated for the degradability. The biodegradability of these
materials was followed by bio-reactivity kinetics models. Results showed that the addition of modified starch could enhance
its water uptake. With an addition of 20 wt% of modified starch, the blend had a maximum weight loss during enzymatic degradation.
It was found that the degradability was enhanced with the addition of the starch. Analyzing the results of the biodegradability
based on the kinetic models, the growth rate of the microorganism was found to be increasing with the increase of the content
of starch in the PVA/starch blends in the first order reaction fashion. In our biodegradability analysis, i.e., based on the
China national standards (CNS) 14432 regulations, we estimated the decomposition behavior based on the mentioned first order
reaction. We found that the PVA/starch blends would take 32.47, 16.20 and 12.47 years to degrade by 70% as their starch content
0, 20 and 40 wt%, respectively. 相似文献
120.
二元有机酸的络合萃取研究 总被引:2,自引:0,他引:2
研究了磷酸三丁酯(TBP)和甲基异丁基酮(MIBK)对乙二酸,丙二酸,丁二酸和己二酸等二元有机酸的萃取及其影响因素。结果表明,萃取反应为中性络合萃取机理,有机相中生成1:2的萃合物;空腔效应,偶极作用和氢键等是影响萃取性能的主要因素;稀释剂,无机盐,温度及二元有机酸结构等对萃取性能都有重要影响。 相似文献