全文获取类型
收费全文 | 2269篇 |
免费 | 119篇 |
国内免费 | 783篇 |
专业分类
安全科学 | 181篇 |
废物处理 | 134篇 |
环保管理 | 163篇 |
综合类 | 1274篇 |
基础理论 | 399篇 |
污染及防治 | 713篇 |
评价与监测 | 84篇 |
社会与环境 | 60篇 |
灾害及防治 | 163篇 |
出版年
2024年 | 3篇 |
2023年 | 45篇 |
2022年 | 126篇 |
2021年 | 109篇 |
2020年 | 65篇 |
2019年 | 74篇 |
2018年 | 80篇 |
2017年 | 109篇 |
2016年 | 118篇 |
2015年 | 149篇 |
2014年 | 159篇 |
2013年 | 230篇 |
2012年 | 186篇 |
2011年 | 196篇 |
2010年 | 152篇 |
2009年 | 127篇 |
2008年 | 148篇 |
2007年 | 123篇 |
2006年 | 112篇 |
2005年 | 78篇 |
2004年 | 63篇 |
2003年 | 78篇 |
2002年 | 65篇 |
2001年 | 59篇 |
2000年 | 61篇 |
1999年 | 80篇 |
1998年 | 62篇 |
1997年 | 60篇 |
1996年 | 54篇 |
1995年 | 50篇 |
1994年 | 27篇 |
1993年 | 38篇 |
1992年 | 31篇 |
1991年 | 25篇 |
1990年 | 14篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1984年 | 3篇 |
1981年 | 2篇 |
1958年 | 1篇 |
排序方式: 共有3171条查询结果,搜索用时 31 毫秒
991.
Yan MA Naiyun GAO Wenhai CHU Cong LI 《Frontiers of Environmental Science & Engineering》2013,7(2):158-165
In this study, the adsorption performance of powdered activated carbon (PAC) on phenol was investigated in aqueous solutions. Batch adsorption studies were performed to evaluate the effects of various experimental parameters like PAC type, PAC dose, initial solution pH, temperature and pre-oxidation on the adsorption of phenol by PAC and establish the adsorption kinetics, thermodynamics and isothermal models. The results indicated that PAC adsorption is an effective method to remove phenol from water, and the effects of all the five factors on adsorption of phenol were significant. The adsorption rate of phenol by PAC was rapid, and more than 80% phenol could be absorbed by PAC within the initial 10 min. The adsorption process can be well described by pseudo-second-order adsorption kinetic model with rate constant amounted to 0.0313, 0.0305 and 0.0241 mg·μg -1·min -1 with coal, coconut shell and bamboo charcoal. The equilibrium data of phenol absorbed onto PAC were analyzed by Langmuir, Freundlich and Tempkin adsorption isotherms and Freundlich adsorption isotherm model gave the best correlation with the experimental data. Thermodynamic parameters such as the standard Gibbs free energy (?G o), enthalpy (?H o) and entropy (?S o) obtained in this study indicated that the adsorption of phenol by PAC is spontaneous, exothermic and entropy decreasing. 相似文献
992.
In this paper, a method using solid-phase extraction (SPE) and gas chromatography-mass spectrometry (GC-MS) was developed to simultaneously analyze five taste and odor compounds in surface water, i.e., 2-methylisoborneol (2-MIB), 2,4,6-trichloroanisole (TCA), 2-isopropyl-3-methoxy pyrazine (IPMP), 2-isobutyl-3-methoxy pyrazine (IBMP), and trans -1,10-dimethyl-trans -9-decalol (geosmin, GSM). The mass spectrometry was operated in selective ion monitoring (SIM) mode. Three kinds of SPE columns and three eluting solvents were compared, the C18 column was chosen as optimum SPE column, and methanol was chosen as the optimum eluting solvent. It was found that the method showed good linearity in the range of 1–200 ng·L-1 and gave detection limits of 0.5–1.5 ng·L-1 for individual compounds. Good recoveries (93.5%–108%) and relative standard deviations (1.58%–7.31%) were also obtained. Additionally, concentrations of these taste and odor compounds in Jinan’s surface and drinking water were analyzed by applying this method, and the results showed that GSM and 2-MIB were the dominant taste and odor compounds in Jinan’s raw water. 相似文献
993.
脉冲电晕等离子体降解有毒气体 总被引:1,自引:0,他引:1
采用脉冲电晕放电等离子体对化学毒剂模拟剂氯膦酸二乙酯(DECP)进行降解,结果表明,对初始浓度为70 mg·m-3的DECP降解率为96.4%.通过GC-MS和离子色谱分析,其降解产物主要有CHCl2-CH2Cl、CHCl2-CHCl2、二氯膦酸乙酯、HCl和H3PO4,并根据降解产物探讨了等离子体对DECP的降解反应机理.DECP分子中的P—Cl和C—O键断裂促使DECP矿化为H3PO4和HCl,而C—O键断裂形成的乙基与氯自由基反应形成CHCl2-CH2Cl和CHCl2-CHCl2;同时DECP分子中的一个P—O键发生断裂后与氯自由基结合形成了二氯膦酸乙酯.对DECP的反应动力学进行了分析讨论,得到其反应速率常数为0.0516 m.3(W.h)-1. 相似文献
994.
Wei Gao Ritsu Dobashi Toshio Mogi Jinhua Sun Xiaobo Shen 《Journal of Loss Prevention in the Process Industries》2012,25(6):993-999
To reveal the effects of particle characteristics on the mechanisms of flame propagation during organic dust explosions clearly, three long chain monobasic alcohols which are solids at room temperature and have similar physical–chemical properties were chosen to carry out experiments in a half-closed small chamber. A high-speed video camera was used to record the flame propagation process and to obtain the direct light emission photographs. Flame temperature was detected by a fine thermocouple. Based on the experimental results above, analysis was conducted on flame propagation characteristics and temperature profiles of organic particle cloud. As a result, it was found that the particle materials, especially volatility, strongly affected the flame propagation behavior. Particle concentration also affects the combustion zone propagation process significantly. With increasing the particle concentration, the maximum temperature of the combustion zone increases at the lower concentration, reaches a maximum value, and then decreases at the higher concentration. The propagation velocity of the combustion zone has a linear relationship with the maximum temperature, which implies conductive heat transfer is dominant in the flame propagation process of the three different volatile dusts. 相似文献
995.
请为救灾勇士多准备些"粮草" 总被引:1,自引:0,他引:1
这是写给各类灾害发生后而成立的救灾指挥部的话。“粮草”是古话,有“人马未到,粮草先行”之说,古代打仗用马,故“草”很重要。“粮草”用现代话讲指的就是物资。 相似文献
996.
阐述企业安全文化的起源、内容与建设的必要性,提出从营造安全文化氛围、全面提高员工安全文化素质、再造企业安全工程人手,进行企业安全文化建设。 相似文献
997.
高建洲 《安全.健康和环境》2004,4(11):20-23
结合EPC模式下分包商及劳务用工HSE管理方面存在的问题,对工程分包管理中的HSE控制进行了探讨. 相似文献
998.
模糊ISODATA聚类在矿山环境评价中的应用 总被引:1,自引:0,他引:1
矿山开采一方面繁荣了一方经济,另一方面也对生态环境造成了破坏和污染。被破坏和污染的矿山环境需要治理,治理的前提是如何适时监测和正确评价矿山环境。本文运用模糊数学中的模糊ISODATA聚类.建立模糊关系矩阵,使问题从地质变量空间向评语空间转换,通过对云南个旧某地区的废弃矿区土壤进行测试,应用该方法进行地质环境评价,提供了科学合理的治理依据。 相似文献
999.
1000.
In this paper, the evolution of cooperation is studied by a spatially structured evolutionary game model in which the players are located on a two-dimensional square lattice. Each player can choose one of the following strategies: “always defect” (ALLD), “tit-for-tat” (TFT), and “always cooperate” (ALLC). Players merely interact with four immediate neighbors at first and adjust strategies according to their rewards. First, the evolutionary dynamics of the three strategies in non-spatial population is investigated, and the results indicate that cooperation is not favored in most settings without spatial structure. Next, an analytical method, which is based on comparing the local payoff structures, is introduced for the spatial game model. Using the conditions derived from the method as criteria, the parameter plane for two major parameters of the spatial game model is divided and nine representative regions are identified. In each parameter region, a distinct spatiotemporal dynamics is characterized. The spatiotemporal dynamics not only verify that the spatial structure promote the evolution of cooperation but also reveal how cooperation is favored. Our results show that spatial structure is the keystone of the evolution of intraspecific diversity. 相似文献