全文获取类型
收费全文 | 3376篇 |
免费 | 288篇 |
国内免费 | 1040篇 |
专业分类
安全科学 | 368篇 |
废物处理 | 174篇 |
环保管理 | 273篇 |
综合类 | 1937篇 |
基础理论 | 482篇 |
污染及防治 | 962篇 |
评价与监测 | 170篇 |
社会与环境 | 167篇 |
灾害及防治 | 171篇 |
出版年
2024年 | 14篇 |
2023年 | 83篇 |
2022年 | 209篇 |
2021年 | 208篇 |
2020年 | 216篇 |
2019年 | 143篇 |
2018年 | 150篇 |
2017年 | 187篇 |
2016年 | 202篇 |
2015年 | 246篇 |
2014年 | 226篇 |
2013年 | 352篇 |
2012年 | 321篇 |
2011年 | 327篇 |
2010年 | 251篇 |
2009年 | 200篇 |
2008年 | 221篇 |
2007年 | 196篇 |
2006年 | 148篇 |
2005年 | 134篇 |
2004年 | 100篇 |
2003年 | 86篇 |
2002年 | 82篇 |
2001年 | 60篇 |
2000年 | 52篇 |
1999年 | 51篇 |
1998年 | 54篇 |
1997年 | 37篇 |
1996年 | 23篇 |
1995年 | 33篇 |
1994年 | 20篇 |
1993年 | 17篇 |
1992年 | 13篇 |
1991年 | 12篇 |
1990年 | 2篇 |
1989年 | 6篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
排序方式: 共有4704条查询结果,搜索用时 0 毫秒
121.
为去除化工生产等过程中产生的酸雾废气,首先用水作用法、微波法和传统湿法对粉煤灰进行改性试验,结果显示:传统湿法中的碱法效果最佳,改性后粉煤灰的BET比表面积是改性前的8.23倍.再用改性后的粉煤灰与廉价易得的天然矿物沸石和熟石灰作为活性组分,制得一种新型的复合吸附剂.常温常压下,动态吸附盐酸雾,实验结果表明:由改性粉煤灰制作的吸附剂G对盐酸雾的吸附性能比未经改性的吸附剂W有所提高,在文中所述条件下,饱和吸附量由改性前的331.4 mg/g提高到改性后的445.2 mg/g. 相似文献
122.
In situ iron activated persulfate oxidative fluid sparging treatment of TCE contamination--a proof of concept study 总被引:1,自引:0,他引:1
In situ chemical oxidation (ISCO) is considered a reliable technology to treat groundwater contaminated with high concentrations of organic contaminants. An ISCO oxidant, persulfate anion (S(2)O(8)(2-)) can be activated by ferrous ion (Fe(2+)) to generate sulfate radicals (E(o)=2.6 V), which are capable of destroying trichloroethylene (TCE). The property of polarity inhibits S(2)O(8)(2-) or sulfate radical (SO(4)(-)) from effectively oxidizing separate phase TCE, a dense non-aqueous phase liquid (DNAPL). Thus the oxidation primarily takes place in the aqueous phase where TCE is dissolved. A bench column study was conducted to demonstrate a conceptual remediation method by flushing either S(2)O(8)(2-) or Fe(2+) through a soil column, where the TCE DNAPL was present, and passing the dissolved mixture through either a Fe(2+) or S(2)O(8)(2-) fluid sparging curtain. Also, the effect of a solubility enhancing chemical, hydroxypropyl-beta-cyclodextrin (HPCD), was tested to evaluate its ability to increase the aqueous TCE concentration. Both flushing arrangements may result in similar TCE degradation efficiencies of 35% to 42% estimated by the ratio of TCE degraded/(TCE degraded+TCE remained in effluent) and degradation byproduct chloride generation rates of 4.9 to 7.6 mg Cl(-) per soil column pore volume. The addition of HPCD did greatly increase the aqueous TCE concentration. However, the TCE degradation efficiency decreased because the TCE degradation was a lower percentage of the relatively greater amount of dissolved TCE by HPCD. This conceptual treatment may serve as a reference for potential on-site application. 相似文献
123.
二氧化铅电极的制备、表征及其电催化性能研究 总被引:9,自引:0,他引:9
以电沉积法制备了Ti/PbO2和Ti/MnO2/PbO22种电极.采用SEM、XRD和XPS等分析方法表征了电极的形貌、元素组成及元素化学态,并以罗丹明B为目标有机物,考察了所制备电极的析氧极化曲线和电催化活性以及Ti/MnO2/PbO2电极的循环伏安曲线.研究结果表明,Ti/MnO2/PbO2电极的稳定性、使用寿命、析氧电位和电催化活性较Ti/PbO2电极都有所提高,并且罗丹明B在Ti/MnO2/PbO2电极上的反应主要发生在析氧反应区,且反应不可逆. 相似文献
124.
125.
126.
动物体内乙酰胆碱酯酶(ACHE)的活性变化常被用于表征环境中有机磷农药(OPs)的污染状况.以鲅鱼脑组织AChE粗酶液为试验材料,以甲基对硫磷为OPs代表,从不同条件海水中鲅鱼AChE的活性变化人手,优化甲基对硫磷对鲅鱼AChE活性的抑制条件,获得了甲基对硫磷浓度与AChE活性抑制程度之间的关系曲线.结果表明,抑制时间为30min,温度为35℃,海水pH为7.5时,鲅鱼AChE的活性较高,甲基对硫磷对其抑制程度最强;在最佳的抑制条件下,甲基对硫磷在10~500 μg/L时,其质量浓度与AChE活性抑制率之间具有良好的线性关系(R=0.994 4),检测下限低于1.0 μg/L. 相似文献
127.
A rapid spectrophotometric determination of persulfate anion in ISCO 总被引:10,自引:0,他引:10
Due to a gradual increase in the use of persulfate as an in situ chemical oxidation (ISCO) oxidant, a simple measurement of persulfate concentration is desirable to analyze persulfate distribution at designated time intervals on/off a site. Such a distribution helps evaluate efficacy of ISCO treatment at a site. This work proposes a spectrophotometric determination of persulfate based on modification of the iodometric titration method. The analysis of absorption spectra of a yellow color solution resulting from the reaction of persulfate and iodide in the presence of sodium bicarbonate reveals an absorbance at 352 nm, without significant interferences from the reagent matrix. The calibration graph was linear in the range of persulfate solution concentration of 0-70 mM at 352 nm. The proposed method is validated by the iodometric titration method. The solution pH was at near neutral and the presence of iron activator does not interfere with the absorption measurement. Also, analysis of persulfate in a groundwater sample using the proposed method indicates a good agreement with measurements by the titration method. This proposed spectrophotometric quantification of persulfate provides a simple and rapid method for evaluation of ISCO effectiveness at a remediation site. 相似文献
128.
Sedimentary record of polycyclic aromatic hydrocarbons in Lake Erhai,
Southwest China 总被引:1,自引:0,他引:1
Jianyang Guo Zhang Liang Haiqing Liao Zhi Tang Xiaoli Zhao Fengchang Wu 《环境科学学报(英文版)》2011,23(8):1308-1315
The temporal distribution of polycyclic aromatic hydrocarbons (PAHs) was investigated in a sediment core from Lake Erhal in Southwest China using gas-chromatography/mass spectrometry (GC/MS) method.The total organic carbon (TOC) normalized total PAHs concentrations (sum of US Environmental Protection Agency proposed 16 priority PAHs) ranged from 31.9 to 269 μg/g dry weight (dw),and were characterized by a slowly increasing stage in the deeper sediments and a sharp increasing stage in the upper sediments.The PAHs in the sediments were dominated by low molecular weight (LMW) PAHs,suggesting that the primary source of PAHs was low- and moderate temperature combustion processes.However,both the significant increase in high molecular weight (HMW) PAHs in the upper sediments and the vertical profile of diagnostic ratios pointed out a change in the sources of PAHs from low-temperature combustion to high-temperature combustion.The ecotoxicological assessment based on consensus-based sediment quality guidelines implied that potential adverse biological impacts were possible for benzo(ghi)perylenelene and most LMW PAHs.In addition,the total BaP equivalent quotient of seven carcinogenic polycyclic aromatic hydrocarbons (BaA,CHr,BbF,BkF,BaP,DBA and INP) was 106.1 ng/g,according to the toxic equivalency factors.Although there was no great biological impact associated with the HMW PAlls,great attention should be paid to these PAH components based on their rapid increase in the upper sediments. 相似文献
129.
Shuai Liang Peng Gao Xiaoqi Gao Kang Xiao Xia Huang 《Frontiers of Environmental Science & Engineering》2016,10(6):9
Membrane modification is one of the most feasible and effective solutions to membrane fouling problem which tenaciously hampers the further augmentation of membrane separation technology. Blending modification with nanoparticles (NPs), owing to the convenience of being incorporated in established membrane production lines, possesses an advantageous viability in practical applications. However, the existing blending strategy suffers from a low utilization efficiency due to NP encasement by membrane matrix. The current study proposed an improved blending modification approach with amphiphilic NPs (aNPs), which were prepared through silanization using 3-(Trimethoxysilyl)propyl methacrylate (TMSPMA) as coupling agents and ZnO or SiO2 as pristine NPs (pNPs), respectively. The Fourier transform infrared and X-ray photoelectron spectroscopy analyses revealed the presence of appropriate organic components in both the ZnO and SiO2 aNPs, which verified the success of the silanization process. As compared with the pristine and conventional pNP-blended membranes, both the ZnO aNP-blended and SiO2 aNP-blended membranes with proper silanization (100% and 200%w/w) achieved a significantly increased blending efficiency with more NPs scattering on the internal and external membrane surfaces under scanning electron microscope observation. This improvement contributed to the increase of membrane hydrophilicity. Nevertheless, an extra dosage of the TMSPMA led to an encasement of NPs, thereby adversely affecting the properties of the resultant membranes. On the basis of all the tests, 100% (w/w) was selected as the optimum TMSPMA dosage for blending modification for both the ZnO and SiO2 types.
相似文献
130.
Huachang Hong Qianyun Song Asit Mazumder Qian Luo Jianrong Chen Hongjun Lin Haiying Yu Liguo Shen Yan Liang 《Environmental geochemistry and health》2016,38(6):1303-1312
The purpose of this study was to develop the multiple regression models to evaluate the formation of trihalomethanes (THMs) and haloacetonitriles (HANs) during chlorination of source water with low specific ultraviolet absorbance (SUVA) in Yangtze River Delta, China. The results showed that the regression models of THMs exhibited good accuracy and precision, and 86–97 % of the calculated values fell within ±25 % of the measured values. While the HANs models showed relatively weak evaluation ability, as only 75–83 % of the calculated values were within ±25 % of the measured values. The organic matter [dissolved organic carbon (DOC) or UV absorbance at 254 nm] and bromide exerted the most important influence on the formation of HANs. While for THMs, besides the organic matter and bromide, reaction time was also a key factor. Comparing the models for total THMs (T-THMs) in this study with others revealed that the regression models from the low SUVA waters may have low DOC coefficients, but high bromide coefficients as compared with those from the high SUVA waters. 相似文献