全文获取类型
收费全文 | 2233篇 |
免费 | 196篇 |
国内免费 | 760篇 |
专业分类
安全科学 | 216篇 |
废物处理 | 136篇 |
环保管理 | 163篇 |
综合类 | 1454篇 |
基础理论 | 307篇 |
环境理论 | 1篇 |
污染及防治 | 565篇 |
评价与监测 | 98篇 |
社会与环境 | 157篇 |
灾害及防治 | 92篇 |
出版年
2024年 | 8篇 |
2023年 | 40篇 |
2022年 | 136篇 |
2021年 | 138篇 |
2020年 | 117篇 |
2019年 | 91篇 |
2018年 | 110篇 |
2017年 | 124篇 |
2016年 | 110篇 |
2015年 | 129篇 |
2014年 | 175篇 |
2013年 | 233篇 |
2012年 | 198篇 |
2011年 | 206篇 |
2010年 | 172篇 |
2009年 | 161篇 |
2008年 | 155篇 |
2007年 | 109篇 |
2006年 | 161篇 |
2005年 | 97篇 |
2004年 | 65篇 |
2003年 | 58篇 |
2002年 | 58篇 |
2001年 | 51篇 |
2000年 | 56篇 |
1999年 | 41篇 |
1998年 | 37篇 |
1997年 | 25篇 |
1996年 | 22篇 |
1995年 | 32篇 |
1994年 | 13篇 |
1993年 | 14篇 |
1992年 | 12篇 |
1991年 | 10篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有3189条查询结果,搜索用时 15 毫秒
731.
有机磷农药对海洋微藻致毒性的生物学研究Ⅰ.四种海洋微藻对久效磷的耐受力与其SOD活性的相关性 总被引:8,自引:0,他引:8
本文研究了久效磷农药对扁藻、三角褐指藻、金藻和盐藻的毒性实验。结果表明,四种海洋微藻对久效磷的耐受力依次为:盐藻>三角褐指藻>金藻>扁澡。对微藻细胞内过氧化物歧化酶(SOD)活性的测定表明,四种海洋微藻对久效磷的耐受力与其SOD活性具相关性,耐受力最强的盐藻其细胞内SOD活性较高,并在久效磷的胁迫下保持相对稳定;耐受力较弱的三角褐指藻和金藻其细胞内SOD活性随着久效磷浓度的提高逐渐下降;而耐受力弱的扁藻在久效磷胁迫下,其细胞内SOD活性迅速下降。因此,可从SOD活性及其变化规律上判断久效磷对海洋环境污染的程度以及海洋微藻的耐受力。 相似文献
732.
有害废弃物几种固化方法 总被引:4,自引:0,他引:4
木文介绍了有害废弃物5种固化—稳定化方法,并给出实例以及固化效果的影响因素分析. 相似文献
733.
论现代战争与环境污染 总被引:1,自引:0,他引:1
收集了大量有关海湾战争等现代战争造成的环境污染,包括空气、水和土壤污染的来源、种类以及污染程度等资料,分析了现代战争对环境的严重污染和巨大破坏作用,论述了如何正确处理战争与环境保护的关系。 相似文献
734.
水相催化芳香氯化物脱氯研究 总被引:4,自引:0,他引:4
通过把起相转移作用的聚乙二醇(PEG)链,键合到硅胶上,再将聚乙烯吡咯烷酮(PVP)络合双金属Pd-Cu后负载其上,制成一种新型双负载双金属催化剂PVP-PdCl2/SiO2-PEG600,以甲酸钠为氢转移试剂,在水相催水芳香氯化物脱氯,当反应温度80℃左右,n(Pd):n(Cu)=2:1,反应介质pH值11.7左右时,具有较高的催化脱卤活性,催化剂不但易于制备,便于分离,且具有良好的重复使用性能,经重复使用六次,转化率仍在70%以上。 相似文献
735.
Wenjuan Liao Hao-Jie Cui Yaqi Ning Cong Wu Wei Peng Dong Cheng Lichu Yin Weijun Zhou 《环境科学学报(英文版)》2023,35(2):688-698
It has been documented that organic contaminants can be degraded by hydroxyl radicals ( • OH) produced by the activation of H2 O2 by Fe(II)-bearing clay. However, the interfacial electron transfer reactions between structural Fe(II) and H 2 O 2 for • OH generation and its effects on contaminant remediation are unclear. In this study, we first investigated the relation between • OH generation sites and sulfamethoxazole (SMX) degradation by activating H2O2 using nontronite with different reduction extents. SMX (5.2–16.9 μmol/L) degradation first increased and then decreased with an increase in the reduction extent of nontronite from 22% to 62%, while the • OH production increased continually. Passivization treatment of edge sites and structural variation results revealed that interfacial electron transfer reactions between Fe(II) and H 2 O 2 occur at both the edge and basal plane. The enhancement on basal plane interfacial electron transfer reactions in a high reduction extent rNAu-2 leads to the enhancement on utilization efficiencies of structural Fe(II) and H 2 O 2 for • OH generation.However, the • OH produced at the basal planes is less efficient in oxidizing SMX than that of at edge sites. Oxidation of SMX could be sustainable in the H 2 O 2 /rNAu-2 system through chemically reduction. The results of this study show the importance role of • OH generation sites on antibiotic degradation and provide guidance and potential strategies for antibiotic degradation by Fe(II)-bearing clay minerals in H 2 O 2 -based treatments. 相似文献
736.
该文分析了企业实施清洁生产的重要意义,阐述了政府组织、企业实施和政策配套是推进清洁生产的三个主要环节,并结合福建省建设生态省的环境保护工作要求,提出依法推进清洁生产工作的对策建议。 相似文献
737.
738.
739.
Excessive nitrate(NO_3~-) is among the most problematic surface water and groundwater pollutants.In this study,a type of magnetic cationic hydrogel(MCH) is employed for NO_3~-adsorption and well characterized herein.Its adsorption capacity is considerably pHdependent and achieves the optimal adsorption(maximum NO_3~--adsorption capacity is95.88±1.24 mg/g) when the pH level is 5.2-8.8.The fitting result using the homogeneous surface diffusion model indicates that the surface/film diffusion controls the adsorption rate,and NO_3~-approaches the center of MCH particles within 30 min.The diffusion coefficient(D_s) and external mass transfer coefficient(k_F) in the liquid phase are1.15 × 10~(-6) cm~2/min and 4.5 × 10~(-6) cm/min,respectively.The MCH is employed to treat surface water that contains 10 mg/L of NO_3~-,and it is found that the optimal magnetic separation time is 1.6 min.The high-efficiency mass transfer and magnetic separation of MCH during the adsorption-regeneration process favors its application in surface water treatment.Furthermore,the study of the mechanism involved reveals that both-N~+(CH_3)_3 groups and NO_3~-are convoluted in adsorption via electrostatic interactions.It is further found that ion exchange between NO_3~-and chlorine occurs. 相似文献
740.
Mineral dust particles play an important role in the formation of secondary inorganic aerosols, which largely contribute to haze pollution in China.During this study, a haze episode(haze days) and a typical haze process mixed with sandstorm(sandy haze days)were observed in Zhengzhou with a series of high-time-resolution monitoring instruments from November 22 to December 8, 2018.Concentrations of PM_(10) and crustal elements clearly increased in the sandy haze days.Concentrations of gaseous pollutants, metallic elements emitted from anthropogenic sources, nitrate, and ammonium during sandy haze days were slightly lower than those during the haze days but still obviously higher than those during the non-haze days.The sulfate concentrations, the sulfate fractions in PM_(2.5),and the sulfur oxidation ratios significantly increased in the sandy haze days.Heterogeneous reactions dominated the conversion of SO_2 during the haze and sandy haze days.Enhanced SO_2 conversion during the sandy haze days may be attributed to the high concentrations of transition metal ions from the sandstorm when the values of relative humidity(RH) were in 30%–70%, and high O_3 at certain time points.Gas-phase NO_2 oxidation reactions were the main pathways for nitrate formation.In the sandy haze days,higher nitrogen oxidation ratio(NOR) at daytime may be associated with higher RH and lower temperature than those in the haze days, which facilitate the gas-to-particle partitioning of nitrate; higher NOR values at night may be attributed to the higher O_3 concentrations, which promoted the formation of N_2O_5. 相似文献