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Lu Huang Xin Wen Yan Wang Yongde Zou Baohua M Xindi Liao Juanboo Liang Yinbao Wu 《环境科学学报(英文版)》2014,26(10):2001-2006
Effects of antibiotic residues on methane production in anaerobic digestion are commonly studied using the following two antibiotic addition methods:(1) adding manure from animals that consume a diet containing antibiotics, and(2) adding antibiotic-free animal manure spiked with antibiotics. This study used chlortetracycline(CTC) as a model antibiotic to examine the effects of the antibiotic addition method on methane production in anaerobic digestion under two different swine wastewater concentrations(0.55 and 0.22 mg CTC/g dry manure). The results showed that CTC degradation rate in which manure was directly added at 0.55 mg CTC/g(HSPIKE treatment) was lower than the control values and the rest of the treatment groups. Methane production from the HSPIKEtreatment was reduced(p 〈 0.05) by 12% during the whole experimental period and 15% during the first 7 days. The treatments had no significant effect on the pH and chemical oxygen demand value of the digesters, and the total nitrogen of the0.55 mg CTC/kg manure collected from mediated swine was significantly higher than the other values. Therefore, different methane production under different antibiotic addition methods might be explained by the microbial activity and the concentrations of antibiotic intermediate products and metabolites. Because the primary entry route of veterinary antibiotics into an anaerobic digester is by contaminated animal manure, the most appropriate method for studying antibiotic residue effects on methane production may be using manure from animals that are given a particular antibiotic, rather than adding the antibiotic directly to the anaerobic digester. 相似文献
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以3-氨基丙基三甲氧基硅烷为修饰剂,利用修饰方法,制备出氨基修饰SBA-15,并命名为N-SBA-15。采用XRD、FT-IR、N2吸附-脱附对样品进行表征,批量实验研究吸附剂对水中Cu2+的吸附性能,动力学实验数据采用拟一阶动力学方程、拟二阶动力学方程和内扩散方程进行分析。研究结果表明:N-SBA-15对Cu2+的吸附遵循液膜扩散和颗粒内扩散机理,且整个吸附过程更符合拟二阶动力学方程,45℃时Cu2+的最大吸附量达到0.812 mmol/g。Langmuir等温模型可较好地描述Cu2+在N-SBA-15上的吸附行为。热力学研究表明该吸附过程是一个自发、吸热过程,高温有利于吸附。 相似文献
575.
Characteristics of toluene decomposition and formation of nitrogen oxide(NOx) by-products were investigated in a dielectric barrier discharge(DBD) reactor with/without catalyst at room temperature and atmospheric pressure. Four kinds of metal oxides, i.e., manganese oxide(Mn Ox), iron oxide(Fe Ox), cobalt oxide(Co Ox) and copper oxide(Cu O), supported on Al2O3/nickel foam, were used as catalysts. It was found that introducing catalysts could improve toluene removal efficiency, promote decomposition of by-product ozone and enhance CO2 selectivity. In addition, NOx was suppressed with the decrease of specific energy density(SED) and the increase of humidity, gas flow rate and toluene concentration, or catalyst introduction. Among the four kinds of catalysts, the Cu O catalyst showed the best performance in NOx suppression. The Mn Ox catalyst exhibited the lowest concentration of O3 and highest CO2 selectivity but the highest concentration of NOx. A possible pathway for NOx production in DBD was discussed. The contributions of oxygen active species and hydroxyl radicals are dominant in NOx suppression. 相似文献
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Effect of deposit age on adsorption and desorption behaviors of ammonia nitrogen on municipal solid waste 总被引:1,自引:0,他引:1
Yan Liao Yu-Qiang Yang Dong-Sheng Shen Yu-Yang Long 《Environmental science and pollution research international》2013,20(3):1546-1555
Ammonia nitrogen pollution control is an urgent issue of landfill. This research aims to select an optimal refuse for ammonia nitrogen removal in landfill from the point of view of adsorption and desorption behavior. MSW (municipal solid waste) samples which deposit ages were in the range of 5 to 15 years (named as R15, R11, R7, and R5) were collected from real landfill site. The ammonia nitrogen adsorption behaviors of MSW including equilibrium time, adsorption isotherms, and desorption behaviors including equilibrium time were determined. Furthermore, the effects of pH, OM, Cu(II), Zn(II), and Pb(II) on adsorption and desorption behavior of ammonia nitrogen were conducted by orthogonal experiment. The equilibrium time of ammonia nitrogen adsorption by each tested MSW was very short, i.e., 20 min, whereas desorption process needed 24 h and the ammonia nitrogen released from refuses was much lesser than that adsorbed, i.e., accounted for 3.20 % (R15), 14.32 % (R11), 20.59 % (R7), and 20.50 % (R5) of each adsorption quantity, respectively. The maximum adsorption capacity estimated from Langmuir isotherm appeared in R15-KCl, i.e., 25,000 mg kg?1. The best condition for ammonia nitrogen removal from leachate was pH >7.5, OM 23.58 %, Cu(II) <5 mg L?1, Zn(II) <10 mg L?1, and Pb(II) <1 mg L?1. Ammonia nitrogen in landfill leachate could be quickly and largely absorbed by MSW but slowly and infrequently released. The refuse deposited for 15 years could be a suitable material for ammonia nitrogen removal. 相似文献
579.
HaiRong Zhang Hao Pang Lei Zhang Xinde Chen Bing Liao 《Journal of Polymers and the Environment》2013,21(2):329-334
Polyurethane foam (PUF) was prepared from liquefied wood with polymethylene polyphenylisocyanate by one-shot method, with organosilicon as surfactant, water as blowing agent and stannous octoate and triethylene diamine as co-catalyst. The biodegradability of the PUF was studied by soil burial for a period of 12 months. The Fourier transform infrared (FT-IR) study, morphological observation and percent weight loss were used to discuss the biodegradability of polyurethane foam from liquefied wood. The FT-IR analyses showed that the PUF had biodegraded via oxidation of the ether soft segment or degradation of wood components. The weight loss rate showed that the addition of liquefied wood could accelerate the degradation of PUF. 相似文献
580.
本文介绍了摩托车排气净化催化转化器的研究情况 ,包括催化剂的研制及转化器的结构设计 ,经过实验室模拟尾气活性评价、转鼓台架检测、实车试验 ,证明所研制的催化转化器具有较好的催化活性和实用性。同时讨论了催化转化器与二冲程、四冲程摩托车匹配的问题。 相似文献