全文获取类型
收费全文 | 223篇 |
免费 | 21篇 |
国内免费 | 79篇 |
专业分类
安全科学 | 19篇 |
废物处理 | 16篇 |
环保管理 | 14篇 |
综合类 | 136篇 |
基础理论 | 38篇 |
污染及防治 | 52篇 |
评价与监测 | 20篇 |
社会与环境 | 8篇 |
灾害及防治 | 20篇 |
出版年
2023年 | 2篇 |
2022年 | 16篇 |
2021年 | 21篇 |
2020年 | 16篇 |
2019年 | 17篇 |
2018年 | 17篇 |
2017年 | 17篇 |
2016年 | 11篇 |
2015年 | 15篇 |
2014年 | 15篇 |
2013年 | 18篇 |
2012年 | 19篇 |
2011年 | 16篇 |
2010年 | 24篇 |
2009年 | 19篇 |
2008年 | 8篇 |
2007年 | 7篇 |
2006年 | 11篇 |
2005年 | 10篇 |
2004年 | 6篇 |
2003年 | 9篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 7篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1990年 | 1篇 |
排序方式: 共有323条查询结果,搜索用时 343 毫秒
91.
A bed-type filter composed of thin metal alloy fiber was closely examined with dust capturing in cold and hot runs. The investigation of an individual mechanism across the filter bed indicated that the aerated dust could be initially collected by depth filtration, and after a while, surface filtration dominated the overall dust collection. The present metal fiber bed was comparable to the conventional ceramic filters because of its good collection efficiency with low pressure drop. It also showed potential to be used as a prefilter in a diesel exhaust trapping system. 相似文献
92.
An empirical investigation of construction and demolition waste generation rates in Shenzhen city, South China 总被引:1,自引:0,他引:1
The construction and demolition waste generation rates (C&D WGRs) is an important factor in decision-making and management of material waste in any construction site. The present study investigated WGRs by conducting on-site waste sorting and weighing in four ongoing construction projects in Shenzhen city of South China. The results revealed that WGRs ranged from 3.275 to 8.791 kg/m2 and miscellaneous waste, timber for formwork and falsework, and concrete were the three largest components amongst the generated waste. Based on the WGRs derived from the research, the paper also discussed the main causes of waste in the construction industry and attempted to connect waste generation with specific construction practices. It was recommended that measures mainly including performing waste sorting at source, employing skilful workers, uploading and storing materials properly, promoting waste management capacity, replacing current timber formwork with metal formwork and launching an incentive reward program to encourage waste reduction could be potential solutions to reducing current WGRs in Shenzhen. Although these results were derived from a relatively small sample and so cannot justifiably be generalized, they do however add to the body of knowledge that is currently available for understanding the status of the art of C&D waste management in China. 相似文献
93.
94.
西海固地区可持续发展中的生态环境问题及对策 总被引:8,自引:1,他引:7
米文宝 《中国人口.资源与环境》2000,10(3):79-81
本文分析了宁夏西海固贫困少数民族地区生态环境的基本特征和影响因素,提出了生态环境整治与建设的基本对策。 相似文献
95.
用数理统计的原理,当样本容量满足检验方法要求时,用柯尔莫哥洛夫--斯米尔诺夫、皮尔逊、概率纸等法对绵阳市城区SO2监测值进行分布类型的统计检验。其结果SO2的时空分布类型为近似对数正态。用几何均数代表样本的平均值,例行监测时段的SO2测值与增加采样频率后的测值基本无差异。而用算术均数表示平均值时,均值则落在总体均值的置信区间外。故当样本分布类型确定后,样本的主要特征数应由分布类型确定。 相似文献
96.
本文通过中俄两国在水质铁锰测定结果的差异问题,对采样后不同的保存和预处理方法对测定结果的影响进行了实验研究。研究指出了目前对重金属分析测试结果与《地表水环境质量标准》中标准限值的涵义之间存在的问题,并提出了相应解决问题的方式方法。 相似文献
97.
98.
Sulfate-containing aerosol (SCA) dry deposition at the highway intersection, coastal location, and suburban area in Taiwan were analyzed and compared. Sampling was accomplished with a surrogate surface technique. Samples particles were coated with barium chloride (BaCl(2)) in a vacuum evaporator and then exposed to a relative humidity of 85% for 2 h to form distinctive products of SCAs. Treated samples were examined by a scanning electron microscopy. SCA dry deposition fluxes were 10.2, 4.1, 3.4 microgm(-2)s(-1) and nonsulfate-containing aerosol (NSCA) dry deposition fluxes were 23.3, 8.2, 13.5 microgm(-2)s(-1) at the highway intersection, coastal, and suburban areas. At the highway intersection, both SCA and NSCA dry deposition fluxes were much higher than those at the other two sites. The dry deposition of particles was also analyzed with a traditional technique. The number median diameters (NMDs) of SCA were 0.41, 0.82, and 1.2 mum at the highway intersection, coastal, and suburban sites, respectively. The highway intersection site had a small NMD, which showed that most sulfate-containing deposited aerosols existed in fine diameter range. The mass median diameters (MMDs) of SCA were 8.8, 19.5, and 14.9 mum at the highway intersection, coastal, and suburban sites, which were much higher than NMDs. Average numbers of SCAs in total particulate were 33%, 33%, and 22% at the highway intersection, coastal and suburban areas Most deposited particulates were nonsulfate-containing at the three sampling sites. SCAs less than 10 mum contributed 29%, 8%, and 7% to the total dry deposition at the highway intersection, coastal, and suburban areas, respectively. The contribution of fine particulate was significantly higher at the highway intersection site. 相似文献
99.
降雨入渗对基坑工程安全性影响的研究 总被引:10,自引:0,他引:10
很多市政工程以及基坑工程在降雨入渗后 ,出现滑坡等事故 ,本文应用非饱和土壤水分运动基本理论 ,建立了降雨入渗模型并编制了计算程序。在计算模型中 ,考虑了降雨过程中土壤入渗能力的变化 ,在此基础上 ,采用非饱和土强度理论 ,编制了可考虑基质吸力影响的边坡安全系数计算程序 ;讨论了降雨强度、降雨持续时间、土壤初始含水量和土的渗透系数等参数对降雨入渗及边坡安全性的影响。 相似文献
100.
Yuji Sakuno Esteban R. Miño Satoshi Nakai Hidemi Mutsuda Tetsuji Okuda Wataru Nishijima Rolando Castro Amarillis García Rosanna Peña Marcos Rodríguez G. Conrado Depratt 《Environmental monitoring and assessment》2014,186(7):4181-4193
This study aims to study the distribution of contaminants in rivers that flow into the Caribbean Sea using chlorophyll-a (Chl-a) and suspended sediment (SS) as markers and ALOS AVNIR-2 satellite sensor data. The Haina River (HN) and Ozama and Isabela Rivers (OZ-IS) that flow through the city of Santo Domingo, the capital of the Dominican Republic, were chosen. First, in situ spectral reflectance/Chl-a and SS datasets obtained from these rivers were acquired in March 2011 (case A: with no rain influence) and June 2011 (case B: with rain influence), and the estimation algorithm of Chl-a and SS using AVNIR-2 data was developed from the datasets. Moreover, the developed algorithm was applied to AVNIR-2 data in November 2010 for case A and August 2010 for case B. Results revealed that for Chl-a and SS estimations under cases A and B conditions, the reflectance ratio of AVNIR-2 band 4 and band 3 (AV4/AV3) and the reflectance of AVNIR-2 band 4 (AV4) were effective. The Chl-a and SS mapping results obtained using AVNIR-2 data corresponded with the field survey results. Finally, an outline of the distribution of contaminants at the mouth of the river that flows into the Caribbean Sea was obtained for both rivers in cases A and B. 相似文献