全文获取类型
收费全文 | 306篇 |
免费 | 7篇 |
国内免费 | 34篇 |
专业分类
安全科学 | 97篇 |
废物处理 | 14篇 |
环保管理 | 26篇 |
综合类 | 108篇 |
基础理论 | 32篇 |
污染及防治 | 51篇 |
评价与监测 | 18篇 |
社会与环境 | 1篇 |
出版年
2023年 | 11篇 |
2022年 | 6篇 |
2021年 | 16篇 |
2020年 | 16篇 |
2019年 | 11篇 |
2018年 | 5篇 |
2017年 | 5篇 |
2016年 | 9篇 |
2015年 | 27篇 |
2014年 | 9篇 |
2013年 | 22篇 |
2012年 | 16篇 |
2011年 | 17篇 |
2010年 | 5篇 |
2009年 | 16篇 |
2008年 | 23篇 |
2007年 | 25篇 |
2006年 | 15篇 |
2005年 | 7篇 |
2004年 | 11篇 |
2003年 | 11篇 |
2002年 | 9篇 |
2001年 | 4篇 |
2000年 | 9篇 |
1999年 | 4篇 |
1998年 | 6篇 |
1997年 | 9篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 8篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
排序方式: 共有347条查询结果,搜索用时 187 毫秒
151.
对用亚甲基蓝分光光度法测定大气中硫化氢的标准溶液、样品的稳定性、温度对试剂空白的影响等问题进行了一些研究。得出:硫化氢标准使用液用磁性锌氨络盐吸收液配制,冰箱保存至少可稳定2个月;温度对试剂空白值有影响,应根据不同显色温度,确定不同显色时间;绘制标准曲线和样品测定应用同一量器迅速加入显色剂,以提高其灵敏度。 相似文献
152.
A novel mitigation system against hydrogen-air deflagrations in nuclear power plant buildings is proposed and developed through a series of field experiments using explosion vessels of different volume sizes. The mitigation system is installed on the outer surface of the vessels, and it comprises flame arrester and explosion air bag. The flame arrester is made by stacking 10–20 sheets of fine-mesh wire screens, and the air bag is connected for holding explosion gas. The successful mitigation mechanism is the sequence of pressure-rise reduction by the air bag expansion, flame quenching by the flame arrester, and the slow burning of the gas mixture sucked from the air bag back into the vessel due to the negative pressure caused by the rapid condensation of water vapor inside the vessel. Necessary conditions for the successful mitigation system are discussed, and the practical unit size of flame arrester sheet is recommended. 相似文献
153.
S. Shiva Kumar S.U.B. Ramakrishna B. Rama Devi 《International Journal of Green Energy》2018,15(10):558-567
PEM water electrolysis is one of the most efficient methods for the production of hydrogen because of produced high purity of the gases and environmentally friendly. In the present study, Phosphorus-doped Graphene (PG) was synthesized by thermal annealing of triphenylphosphine (TPP) and graphene oxide (GO). The PG supported palladium (Pd/PG) electrocatalysts were synthesized by chemical reduction method and used as the cathode for hydrogen evolution reaction (HER) electrode. Structural properties and electrochemical performances of the synthesized Pd/PG electrocatalyst were studied by FE-SEM, EDS, ICP, FT-IR, XRD, and Cyclic voltammetry (CV) methods, respectively. The membrane electrode assemblies (MEA’s) were fabricated using Pd/PG as cathode for HER electrode and RuO2 as anode for OER electrode. Also, their electrochemical performances along with the corresponding hydrogen yields were evaluated in single cell PEM water electrolyzer at various experimental conditions such as different current densities from 0.1 to 2.0 A cm?2 and temperatures (28–80°C). The synthesized Pd/PG electrocatalyst was observed a current density of 1 A cm?2 with 1.95 V at 80°C. Further, long-term stability studies were carried out continuously up to 2000 h which showed a reasonable stability. Hence, the synthesized Pd/PG can be used as an alternative to Pt-based electrocatalysts for the HER in PEM water electrolysis. 相似文献
154.
155.
We report the first use of vacuum ultraviolet (VUV) treatment to decompose 1,4-dioxane, a persistent organic contaminant that is difficult to remove by conventional drinking water treatment processes. The efficiency of VUV treatment was compared to that of VUV- and UV-based advanced oxidation processes (AOPs) (VUV/TiO2, VUV/H2O2, UV/TiO2, and UV/H2O2), and by-product formation was investigated. VUV treatment decomposed 1,4-dioxane more rapidly than did UV and UV/TiO2 treatments. The decomposition rate was enhanced when VUV irradiation was combined with TiO2 or H2O2. VUV/H2O2 decomposed 1,4-dioxane more rapidly than UV/H2O2 at a low H2O2 dose (1 mg/L), but the rate difference became small at a high H2O2 dose (5 mg/L). Electrical energy per order analysis revealed that VUV treatment, and the VUV- and UV-based AOPs, were economically feasible for 1,4-dioxane decomposition. Using raw water samples, we investigated by-product formation during VUV treatment and the effect of VUV irradiation on chlorinated disinfection by-product formation potential. Although the samples contained high concentrations of bromide, no bromate was produced by VUV treatment. VUV treatment slightly decreased trihalomethane formation potential (THMFP), whereas haloacetic acid formation potential (HAAFP) was unchanged, and total aldehyde concentration increased. The trend in HAAFP agreed with that had been reported for the VUV irradiation with much higher dose (Buchanan et al., 2006), whereas the trend in THMFP was different from that with much higher dose. THMFP, HAAFP, and aldehyde concentration were reduced by subsequent treatment with granular activated carbon (GAC) or biological activated carbon (BAC). Nitrite was produced by VUV treatment but disappeared after subsequent BAC treatment. These results suggest that VUV treatment should be combined with GAC or BAC treatment to suppress by-product formation. 相似文献
156.
Biotreatment of various ratios of H2S and NH3 gas mixtures was studied using the biofilters, packed with co-immobilized cells (Arthrobacter oxydans CH8 for NH3 and Pseudomonas putida CH11 for H2S). Extensive tests to determine removal characteristics, removal efficiency, removal kinetics, and pressure drops of the biofilters were performed. To estimate the largest allowable inlet concentration, a prediction model was also employed. Greater than 95% and 90% removal efficiencies were observed for NH3 and H2S, respectively, irrespective of the ratios of H2S and NH3 gas mixtures. The results showed that H2S removal of the biofilter was significantly affected by high inlet concentrations of H2S and NH3. As high H2S concentration was an inhibitory substrate for the growth of heterotrophic sulfur-oxidizing bacteria, the activity of H2S oxidation was thus inhibited. In the case of high NH3 concentration, the poor H2S removal efficiency might be attributed to the acidification of the biofilter. The phenomenon was caused by acidic metabolite accumulation of NH3. Through kinetic analysis, the presence of NH3 did not hinder the NH3 removal, but a high H2S concentration would result in low removal efficiency. Conversely, H2S of adequate concentrations would favor the removal of incoming NH3. The results also indicated that maximum inlet concentrations (model-estimated) agreed well with the experimental values for space velocities of 50–150 h−1. Hence, the results would be used as the guideline for the design and operation of biofilters. 相似文献
157.
活性炭吸附硫化氢及微波辐照解吸研究 总被引:13,自引:0,他引:13
研究了两种活性炭对硫化氢的平衡吸附性能力,并对活性炭床层的穿透性进行了考察;吸附饱和和活性炭在微波辐射的作用下进行解吸。实验表明,解吸效率与微波作用时间及温度有关,在本实验条件下H2S解吸效率达90.1%。 相似文献
158.
S.M. Frolov M. Emans V.S. Ivanov B. Basara V.V. Leshevich O.G. Penyazkov 《Journal of Loss Prevention in the Process Industries》2013,26(6):1558-1568
Low-temperature (at T < 900–950 K) ignition delays of hydrogen–air mixtures are mainly measured in rapid compression machines (RCM). This communication is aimed at numerical simulation of ignition delays of hydrogen–air mixtures in the RCM by means of a coupled three-dimensional (3D) Unsteady Reynolds-Averaged Navier–Stokes (URANS) – Particle Method (PM) simulation of RCM operation capable of catching turbulence–chemistry interaction. The study indicates that the time history of piston motion in an RCM affects the final state of a test mixture at the end of compression stroke and therefore influences the phenomena relevant to test mixture ignition. More specifically, the calculations show that different laws of piston motion at a fixed average piston velocity (i.e., fixed piston displacement and fixed compression time) and fixed compression ratio result in different evolution of mean pressure, temperature and velocity fields in the RCM test section leading to different ignition behavior. The reasons for the arising differences lie in the fact that the local instantaneous piston velocity determines the roll-up vortex structure, strength and turbulence dissipation in it, heat transfer in test-section walls, and mass leakage through piston rings. 相似文献
159.
《International Journal of Green Energy》2013,10(1):129-145
Attempts to improve engine performance are often accompanied by increased emissions. An effective approach to reduce emissions without necessarily a significant penalty in fuel economy is through operating S.I. engines on a range of gaseous fuels, and either leaning the operating mixture or diluting it with some exhaust gases. The emission characteristics of an engine operated in turn on CH4, H2, CO and some of their mixtures are examined experimentally. The role of changes in some key factors affecting the production of the pollutants CO, NOx and unburned hydrocarbons were investigated. Guidelines for reducing the undesirable emissions are outlined. 相似文献
160.
Yang Yang Qi Zhang Baiyang Chen Liangchen Long Guan Zhang 《Frontiers of Environmental Science & Engineering》2022,16(5):55