全文获取类型
收费全文 | 1556篇 |
免费 | 83篇 |
国内免费 | 644篇 |
专业分类
安全科学 | 66篇 |
废物处理 | 121篇 |
环保管理 | 105篇 |
综合类 | 914篇 |
基础理论 | 270篇 |
环境理论 | 2篇 |
污染及防治 | 563篇 |
评价与监测 | 78篇 |
社会与环境 | 51篇 |
灾害及防治 | 113篇 |
出版年
2024年 | 1篇 |
2023年 | 24篇 |
2022年 | 85篇 |
2021年 | 80篇 |
2020年 | 43篇 |
2019年 | 46篇 |
2018年 | 51篇 |
2017年 | 60篇 |
2016年 | 76篇 |
2015年 | 93篇 |
2014年 | 118篇 |
2013年 | 124篇 |
2012年 | 112篇 |
2011年 | 144篇 |
2010年 | 121篇 |
2009年 | 102篇 |
2008年 | 102篇 |
2007年 | 70篇 |
2006年 | 93篇 |
2005年 | 51篇 |
2004年 | 64篇 |
2003年 | 48篇 |
2002年 | 58篇 |
2001年 | 48篇 |
2000年 | 57篇 |
1999年 | 56篇 |
1998年 | 56篇 |
1997年 | 63篇 |
1996年 | 46篇 |
1995年 | 44篇 |
1994年 | 28篇 |
1993年 | 36篇 |
1992年 | 19篇 |
1991年 | 13篇 |
1990年 | 10篇 |
1989年 | 5篇 |
1988年 | 8篇 |
1987年 | 10篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 5篇 |
1930年 | 1篇 |
排序方式: 共有2283条查询结果,搜索用时 15 毫秒
71.
利用遂宁市2017年1月份4个国控环境空气自动监测数据,分析了遂宁市主城区环境空气质量现状,与整个成渝地区和周边城市的空气质量进行了横向比较,并阐述了遂宁市空气质量变化的原因.结果发现遂宁市主城区2017年1月份空气质量指数的范围为32~203,优良率为54.8%,首要污染物为PM2.5,空气质量同比下降了22.8%,环比下降了26.1%,但均显著优于成渝地区和周边城市的平均水平,并从4个方面阐述了空气质量下降的原因.最后,根据遂宁市大气污染现状,提出了4条针对性的防治措施. 相似文献
72.
镉是一种对人类和动物健康危害严重的重金属。土壤镉污染问题已经成为全球研究热点。重点分析了镉污染土壤中镉的来源,镉对动植物、人体的危害,并提出了对镉污染土壤的修复的方法。 相似文献
73.
The adsorption behavior of 2-mercaptobenzothiazole onto organo-bentonite was investigated.Natural bentonite from Gaozhou in Guangdong Province,China was collected.Organo-bentonite was prepared by intercalation of cetyltrimethyl ammonium bromide into the natural bentonite.The physicochemical properties of the prepared organo-bentonite were characterized by X-ray diffraction,N2 adsorption-desorption isotherm and Fourier transform infrared spectroscopy.The results showed that montmorillonite is the main component of the natural bentonite.The basal spacing of the natural bentonite is 1.47 nm,which increased to 1.98 nm on intercalation with cetyltrimethyl ammonium bromide.Moreover,both the surface area and pore volume increased with intercalation.Clear CH2 stretching(3000-2800 cm-1) and scissoring(1480-1450 cm-1) modes of the intercalated surfactants were observed for organobentonite.Compared with the pseudo first-order kinetic model,the pseudo second-order kinetic model is more suitable to describe the adsorption kinetics of 2-mercaptobenzothiazole onto organo-bentonite.The adsorption capacity of 2-mercaptobenzothiazole onto organo-bentonite increased with increasing initial concentration of 2-mercaptobenzothiazole,but decreased with increasing adsorbent dosage.The adsorption isotherm of 2-mercaptobenzothiazole onto organo-bentonite fits well with the Langmuir model.The maximum adsorption capacity of organo-bentonite for 2-mercaptobenzothiazole was 33.61 mg/g,indicating that organo-bentonite is a promising adsorbent for 2-mercaptobenzothiazole. 相似文献
74.
Supercritical water oxidation of polyvinyl alcohol and desizing wastewater:Influence of NaOH on the organic decomposition 总被引:1,自引:0,他引:1
Jie Zhang Shuzhong Wang Yang Guo Donghai Xu Yanmeng Gong Xingying Tang 《环境科学学报(英文版)》2013,25(8):1583-1591
Polyvinyl alcohol is a refractory compound widely used in industry. Here we report supercritical water oxidation of polyvinyl alcohol solution and desizing wastewater with and without sodium hydroxide addition. However, it is difficult to implement complete degradation of organics even though polyvinyl alcohol can readily crack under supercritical water treatment. Sodium hydroxide had a significant catalytic effect during the supercritical water oxidation of polyvinyl alcohol. It appears that the OH ion participated in the C-C bond cleavage of polyvinyl alcohol molecules, the CO2-capture reaction and the neutralization of intermediate organic acids, promoting the overall reactions moving in the forward direction. Acetaldehyde was a typical intermediate product during reaction. For supercritical water oxidation of desizing wastewater, a high destruction rate (98.25%) based on total organic carbon was achieved. In addition, cases where initial wastewater was alkaline were favorable for supercritical water oxidation treatment, but salt precipitation and blockage issues arising during the process need to be taken into account seriously. 相似文献
75.
76.
77.
分析了ABS树脂生产装置丁二烯缓冲罐中丁二烯自聚物的生成原因,提出了预防措施,避免丁二烯自聚物的生成,保证装置的安全平稳运行。 相似文献
78.
79.
安全是石化生产永恒的主题.怎样才能使人们在生产活动中始终绷紧安全弦,牢固树立安全意识,自觉遵守安全操作规程呢?实践证明:积极创建安全文化,是保证安全生产的一条有效途径. 相似文献
80.
Chih Ming M Ya Wen Lee Gui Bing Hong Te Li Su Je Lueng Shie Chang Tang Chang 《环境科学学报(英文版)》2011,23(4):687-692
TiO2 nanoparticles, doped with di erent Pt contents, were prepared by a modified photodeposition method using Degussa P-25 TiO2,
H2PtCl6 6H2O and methanol as the solvents. The physicochemical properties of Pt/TiO2 were investigated by the nitrogen adsorption
and desorption isotherm measurement technique, X-ray di raction analysis and photoluminescence spectra, respectively. Reaction rates
from photocatalytic removal of dichloromethane over Degussa P-25 TiO2 and Pt/TiO2 were evaluated. The average diameter and BET
surface area of the TiO2 catalyst particles were 300 nm and 50 m2/g, respectively. The degradation e ciency was 99.0%, 82.7%, 55.2%,
and 57.9% with TiO2 at inlet concentrations of 50, 100, 200, and 300 ppm, respectively. And the degradation e ciency was 99.3%,
79.7%, 76.5%, and 73.4% with a 0.005 wt.% Pt/TiO2 at inlet concentrations of 50, 100, 200, and 300 ppm, respectively. In addition, we
found that the photoluminescence emission peak intensities decreased with increases in the doping amount of Pt, which indicates that
the irradiative recombination was weakened. Furthermore, the results showed that the UV/0.005 wt.% Pt/TiO2 process was capable of
e ciently decomposing gaseous DCM in air. 相似文献