全文获取类型
收费全文 | 1022篇 |
免费 | 49篇 |
国内免费 | 365篇 |
专业分类
安全科学 | 76篇 |
废物处理 | 67篇 |
环保管理 | 99篇 |
综合类 | 538篇 |
基础理论 | 152篇 |
污染及防治 | 362篇 |
评价与监测 | 53篇 |
社会与环境 | 51篇 |
灾害及防治 | 38篇 |
出版年
2023年 | 22篇 |
2022年 | 48篇 |
2021年 | 41篇 |
2020年 | 32篇 |
2019年 | 38篇 |
2018年 | 49篇 |
2017年 | 45篇 |
2016年 | 51篇 |
2015年 | 48篇 |
2014年 | 64篇 |
2013年 | 98篇 |
2012年 | 74篇 |
2011年 | 95篇 |
2010年 | 74篇 |
2009年 | 57篇 |
2008年 | 60篇 |
2007年 | 64篇 |
2006年 | 54篇 |
2005年 | 47篇 |
2004年 | 31篇 |
2003年 | 35篇 |
2002年 | 34篇 |
2001年 | 22篇 |
2000年 | 43篇 |
1999年 | 30篇 |
1998年 | 28篇 |
1997年 | 28篇 |
1996年 | 24篇 |
1995年 | 16篇 |
1994年 | 16篇 |
1993年 | 7篇 |
1992年 | 12篇 |
1991年 | 12篇 |
1990年 | 17篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有1436条查询结果,搜索用时 156 毫秒
971.
Yaoyin Lou Zhi-Long Ye Shaohua Chen Xin Ye Yujun Deng Jianqiao Zhang 《环境科学学报(英文版)》2018,30(3):144-152
Tetracyclines(TCs) discharged from livestock wastewater have aroused public concerns due to their pharmacological threats to ecosystems and human health. As an important medium in the wastewater, suspended organic matters(SOMs) play vital roles in antibiotics transport and degradation. However, limited information has been reported in the relevant literature. This study investigated TCs sorption behavior on SOM, withdrawn from swine wastewater. High TCs sorption capacities were detected, with the maximum values ranging from 0.337 to 0.679 mg/g. Increasing p H and temperature led to the decline of sorption capacity. Results from three-dimensional excitation–emission matrix fluorescence spectroscopy and Fourier transform infrared spectrometry revealed that amide and carboxyl groups were the main functional groups for TCs adsorption. The interactions between SOM and TCs were clarified as predominated by hydrogen-bonding and cation-exchange in acid conditions, and electrostatic repulsion in neutral or alkaline conditions. Adsorption kinetics modeling was conducted, and a satisfactory fitting was achieved with the Freundlich equation. These results indicated that the adsorption process was a rather complex process, involving a combination of cation-exchange and hydrogen-bonding. The results will provide a better understanding of the capability of SOM for TCs transport and abatement in the wastewater treatment process. 相似文献
972.
Fast screening compositions of PM2.5 by ATR-FTIR: Comparison with results from IC andOC/EC analyzers
Xu Yu Wei Song Qingqing Yu Sheng Li Ming Zhu Yanli Zhang Wei Deng Weiqiang Yang Zhonghui Huang Xinhui Bi Xinming Wang 《环境科学学报(英文版)》2018,30(9):76-88
Chemical speciation of fine particles or PM_(2.5) collected on filters is still a costly and timeconsuming task. In this study, filter-based PM_(2.5) samples were collected during November–December 2013 at four sites in Guangzhou, and the major components were fast screened(~7 min per filter sample) by Attenuated Total Reflectance(ATR)-Fourier Transform Infrared Spectroscopic(FTIR) in comparison with that measured by Organic carbon/Element carbon(OC/EC) analyzer and Ion Chromatography(IC). The concentrations of nitrate, ammonium, sulfate,primary organic carbon(POC) and secondary organic carbon(SOC) measured by OC/EC and IC analyzers were better correlated with their infrared absorption peak heights at 1320 cm~(-1) for nitrate, 1435, 3045 and 3215 cm~(-1) for ammonium, 615 cm~(-1) for sulfate, 690, 760 and 890 cm~(-1) for POC and 1640 and 1660 cm~(-1) for SOC respectively, during polluted days(PM_(2.5) 75 μg/m~3) than during clean days(PM_(2.5)≤ 75 μg/m~3). With the evolution of a haze episode during our field campaign, the concentrations of the major PM_(2.5) components displayed consistent variations with their infrared absorption peak heights, suggesting ATR-FTIR could be a fast and useful technique to characterize filter-based PM_(2.5) compositions particularly during pollution events although cautions should be taken when PM_(2.5) levels are low. Notably, elevated PM_(2.5) mass concentrations occurred with enhanced ratios of [NO_(-3)]/[SO_4~(2-)] and [NH~(+4)]/[SO_4~(2-)], implying that nitrogenous components play vital roles in the PM_(2.5) pollution events in the study region. 相似文献
973.
974.
AdultActinopyga echinites (Jaeger) were collected from northern Taiwan in September 1989. Oocytes were induced to mature by bathing them in ovary juice (ovary-induced ova) or in 10–2
M dithiothreitol (DTT-induced ova). The percentage of germinal vesicle breakdown (GVBD) increased from 0.4 to 6.4% in the former treatment and to 84% in the latter. After artificial fertilization, the embryos were cultured in seawater (35 S) at 25 to 28°C. Larvae were fed with the algaIsochysis aff.galbana at 104–5 cells/ml. Larvae from ovary-induced ova developed faster (18 d to the doliolaria stage) and grew to a larger size (1.13 mm length) than those from DTT-induced ova (20 d to the doliolaria stage and 0.62 mm in length). On the twelfth day, larvae from ovary-induced ova bear lipid spheres. The number of spheres is positively correlated with larval size. Lipid spheres may provide nutrient reserves for larvae during metamorphosis. 相似文献
975.
近几年,环保经济成为中国经济社会可持续发展的必然趋势和内在要求。但由于中国环保经济起步晚,在发展过程中逐渐显露出许多问题,阻碍了环保经济发展步伐,因此针对这些问题,对其进行了改进,以期实现环境与经济和谐发展。为充分发挥环保经济优势,对其发展趋势进行了判断,并分析发展过程中出现的问题,针对这些问题,对其进行改进。然后利用熵值法对某市在实施方法改进后的环保经济发展情况进行实证研究,结果表明:在实施方法改进后,某市的环保经济发展水平得到了极大的提高,方法改进具有一定的成效。 相似文献
976.
广西钦州湾近岸海域“十一·五”期间营养盐变化趋势分析及污染控制重点 总被引:1,自引:0,他引:1
通过2006年-2010年N、P、Si数据分析广西钦州湾海域N、P、Si的变化趋势、富营养化状况以及限制因子。分析表明:钦州外湾DIN、DIP、SiO3-Si含量呈波浪形变化并有所下降,钦州外湾2006年-2010年均为贫营养,外湾海水水质良好。茅尾海DIN值含量较高,海域受到N的影响。茅尾海2006年-2010年为轻度~中度富营养。茅尾海属于磷中等限制富营养,磷酸盐仅表现为相对不足,仍然有爆发赤潮的危险。控制茅尾海富营养化的关键在于控制磷的入海量。 相似文献
977.
排污权交易目前在中国非常受重视,但其中也存在一些问题,主要是企业和政府尚没有处理好经济发展和环境保护的关系,也存在着制度设置不合理的问题。今后应重视排污权交易中的内部和外部条件的建设。内部条件主要有排污总量的确定和排污许可证的发放,外部条件主要包括政府加强环境执法力度和提供有效的排污信息。 相似文献
978.
979.
As the topmost predator in Antarctica, the seal is a unique indicator of Antarctic environment and climate changes. In this study, we collected a sediment core from the Fildes Peninsula of West Antarctica, and used cholesterol, cholestanol, epicoprostanol, coprostanol, and seal hair numbers as the proxy indicators of seal population size and phytol as of general vegetation, and we reconstructed the 20th century history of variation of the seal population and vegetation abundance on this island. The sealing industry in the early 20th century caused the dramatic decline of seal population, and the ban of seal hunting since the 1960s led to its recovery of seal population. The seal population during the past century was primarily controlled by human activities and krill density. The reconstructed relation between seal population and vegetation abundance may oifer new insights into Antarctic environment and ecology. 相似文献
980.