全文获取类型
收费全文 | 528篇 |
免费 | 48篇 |
国内免费 | 182篇 |
专业分类
安全科学 | 47篇 |
废物处理 | 19篇 |
环保管理 | 110篇 |
综合类 | 315篇 |
基础理论 | 94篇 |
污染及防治 | 104篇 |
评价与监测 | 31篇 |
社会与环境 | 36篇 |
灾害及防治 | 2篇 |
出版年
2024年 | 6篇 |
2023年 | 17篇 |
2022年 | 24篇 |
2021年 | 39篇 |
2020年 | 24篇 |
2019年 | 14篇 |
2018年 | 26篇 |
2017年 | 25篇 |
2016年 | 29篇 |
2015年 | 28篇 |
2014年 | 40篇 |
2013年 | 81篇 |
2012年 | 46篇 |
2011年 | 47篇 |
2010年 | 30篇 |
2009年 | 32篇 |
2008年 | 27篇 |
2007年 | 38篇 |
2006年 | 30篇 |
2005年 | 20篇 |
2004年 | 24篇 |
2003年 | 21篇 |
2002年 | 17篇 |
2001年 | 16篇 |
2000年 | 11篇 |
1999年 | 4篇 |
1998年 | 7篇 |
1997年 | 9篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1979年 | 1篇 |
排序方式: 共有758条查询结果,搜索用时 812 毫秒
391.
Mahmoud Elafify Maha Al-Ashmawy Mohammed Elsherbini Amera Abd El Latif Takashi Okanda 《Journal of environmental science and health. Part. B》2020,55(3):265-272
AbstractFood contaminated with Shiga toxin-producing Escherichia coli (STEC) represents a hazardous public health problem worldwide. Therefore, the present study was performed to elucidate the virulent and antimicrobial resistance characteristics of STEC isolated from milk and dairy products marketed in Egypt. A total of 125 samples (raw market milk, bulk tank milk, Kareish cheese, white soft cheese, and small scale-produced ice cream, 25 each) were collected for determination the prevalence and antimicrobial resistance profiling of STEC. Thirty-six STEC isolates were recovered from milk and dairy products. Serological analysis illustrated that three isolates were E. coli O157:H7 and 33 isolates belonged to different serotypes. Molecular examination indicated that all isolates harboured stx1 and/or stx2 genes, 14 isolates expressed eaeA gene and 3 isolates possessed rfbE gene. Antimicrobial resistance profiling of the isolates was both phenotypically and genetically examined. Interestingly, 31 out of 36 (86.11%) isolates were multidrug-resistant and harboured the extended-spectrum β-lactamase encoding genes, namely, blaCTX-M-15, blaSHV-12 and blaCTX-M-14. Moreover, 12 isolates (33.33%) harboured plasmid-mediated quinolone resistant gene, qnrS. The overall conclusion of the current investigation indicated insufficient hygienic measures adopted during milking, handling, and processing leading to development of pathogenic and multidrug-resistant STEC. 相似文献
392.
我国新时期生态保护修复总体战略与重大任务 总被引:2,自引:2,他引:0
生态保护修复是美丽中国建设的重大任务,是加快推进生态文明建设的优先行动,是推动生态产品价值实现的重要基础。近年来,我国生态保护修复取得显著进展,但生态系统本底脆弱、保护修复基础薄弱、管理机制不协调等问题依然突出。在大力推进生态文明建设的新的历史时期,面对百年未有之大变局,我国生态保护修复工作所面临的形势更加严峻,与实现国家生态治理体系和治理能力现代化的要求依然存在较大差距,尚难以满足人民日益增长的优质生态产品需要。本文在总结近年来我国生态保护修复主要进展基础上,分析了未来一段时期生态保护修复面临的问题与挑战,提出新时期生态保护修复应以习近平生态文明思想为统领,以提升生态系统服务功能、协同改善生态环境质量、维护国家生态安全为核心,探索构建生态保护修复与污染防治统筹推进机制,强化监管制度设计、示范样板引领、体制机制创新,加快实现山水林田湖草整体保护、系统修复、综合治理,筑牢美丽中国生态根基。 相似文献
393.
Worawat Jansomboon Narin Boontanon Chongrak Polprasert 《Journal of environmental science and health. Part. B》2018,53(2):108-115
The goals of this study were to determine the levels of three antibiotics – enrofloxacin, flumequine and sulfamethoxazole – in Pangasius catfish products imported into Thailand and to assess the health risks from consumption. To extract these antibiotic residues, acetonitrile, methanol and a small amount of formic acid were used as solvents. Determination of the antibiotics after extraction steps was carried out by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) technique. The results showed that 14 and 3 samples of Pangasius catfish products were contaminated with enrofloxacin and sulfamethoxazole, respectively. No flumequine residue was found. While the concentration levels of these antibiotics in most contaminated samples were lower than the European Union (EU) standard, one sample was found to contain sulfamethoxazole at 245.91 µg kg?1, which was higher than the EU standard (100 µg kg?1), indicating the likelihood that some contaminated freshwater fish products are widely distributed in Thai markets. Notably, the concentration levels of enrofloxacin in samples of Pangasius catfish with skin were higher than in non-skin products, suggesting that products with skin might retain more antibiotic residues than non-skin products. Although the hazard quotient showed that consuming imported Pangasius catfish products, based on the current consumption rate, will not adversely affect consumer health, antibiotic residues in Pangasius catfish products imported into Thailand should be continually monitored. 相似文献
394.
当电工电子产品陷入火灾后因燃烧而产生的烟雾,除含有毒性物质外,其模糊性(不透明性)会妨碍受害者逃生而造成伤亡.烟模糊试验适用于测量和评估这种危险性. 相似文献
395.
396.
397.
火焰原子吸收分光光度法测定生活垃圾堆肥产品中铬 总被引:1,自引:0,他引:1
通过试验研究,建立了硝酸-氢氟酸-高氯酸消解、火焰原子吸收分光光度法测定生活垃圾堆肥产品中的铬。该方法的检出限为5mg/kg(按称取0.5g试样消解定容至50ml计算),用于不同地域堆肥样品中铬的测定,其相对标准偏差(RSD)均在8.90%以下,加标回收率介于90.9%~105.8%之间,可作为一种较理想的检验堆肥产品质量的方法。 相似文献
398.
Bluish green staining in domestic fixtures was observed in three to 9-year-old houses in the city of Talca, located 256 km.
south of Santiago, the capital of Chile. The houses contained copper pipes which were exposed to soft well water, with low
pH and low buffer capacity. The aim of this paper is to establish the chemical composition of the stains and to determine
the conditions by which they were formed. X-ray diffraction analysis of the stains revealed the presence of malachite, a copper
compound that caused green coloring in kettles and water boilers. Dioptase, which is deep green in coloring, was identified
in a bathtub tile. In one house, where blue stains were found in a toilet bowl, the presence of chrysocolla was suggested
by means of X-ray fluorescence. In the field conditions studied it was concluded that the bluish green stains in bathroom
home appliances were generated by the precipitation of copper compounds in places were leakages occur. 相似文献
399.
400.