全文获取类型
| 收费全文 | 269篇 |
| 免费 | 23篇 |
| 国内免费 | 21篇 |
专业分类
| 安全科学 | 5篇 |
| 废物处理 | 10篇 |
| 环保管理 | 78篇 |
| 综合类 | 43篇 |
| 基础理论 | 119篇 |
| 环境理论 | 2篇 |
| 污染及防治 | 31篇 |
| 评价与监测 | 6篇 |
| 社会与环境 | 15篇 |
| 灾害及防治 | 4篇 |
出版年
| 2024年 | 10篇 |
| 2023年 | 15篇 |
| 2022年 | 14篇 |
| 2021年 | 21篇 |
| 2020年 | 26篇 |
| 2019年 | 11篇 |
| 2018年 | 11篇 |
| 2017年 | 8篇 |
| 2016年 | 14篇 |
| 2015年 | 11篇 |
| 2014年 | 8篇 |
| 2013年 | 15篇 |
| 2012年 | 15篇 |
| 2011年 | 25篇 |
| 2010年 | 12篇 |
| 2009年 | 17篇 |
| 2008年 | 10篇 |
| 2007年 | 8篇 |
| 2006年 | 10篇 |
| 2005年 | 6篇 |
| 2004年 | 6篇 |
| 2003年 | 6篇 |
| 2002年 | 6篇 |
| 2001年 | 3篇 |
| 2000年 | 1篇 |
| 1999年 | 3篇 |
| 1998年 | 3篇 |
| 1997年 | 1篇 |
| 1996年 | 1篇 |
| 1995年 | 2篇 |
| 1994年 | 1篇 |
| 1992年 | 2篇 |
| 1991年 | 1篇 |
| 1989年 | 1篇 |
| 1987年 | 3篇 |
| 1986年 | 2篇 |
| 1985年 | 1篇 |
| 1984年 | 1篇 |
| 1982年 | 1篇 |
| 1975年 | 1篇 |
排序方式： 共有313条查询结果，搜索用时 15 毫秒
141.
Ethical Opportunities in Global Agriculture, Fisheries, and Forestry: The Role for FAO 总被引：1，自引：0，他引：1
Darryl R.J. Macer Minakshi Bhardwaj Fumi Maekawa Yuki Niimura 《Journal of Agricultural and Environmental Ethics》2003,16(5):479-504
FAO has a unique and essential rolein addressing the ethical problems facinghumanity and in making these problems intoopportunities for practical resolution. A broadrange of ethical issues in agriculture,fisheries, and forestry were identified byanalysis of the literature and by interviewswith FAO staff. Issues include sharing accessto and preserving natural resources,introduction of new technology, conservatismover the use of genetic engineering, ethics inanimal agriculture, access to information, foodsecurity, sustainable rural development,ensuring participation of all people indecision making and in receiving benefits ofagriculture, reducing corruption, andinvolvement of private and public sectors indecision making. Rather than viewing theseissues as problems, they should be viewed asopportunities for debate, learning aboutothers' views, and resolution. The UnitedNations has an important role to play in howdecisions are made in the global ethical debatein food and agriculture. The ethical role ofFAO is to promote global food security,balanced conservation, management andutilization of natural resources, andsustainable rural development. FAO should fullyand publicly assume its ethicalresponsibilities, gathering and sharinginformation on ethics in its areas of mandate,acting as an interactive forum, and providingexpert guidance on policy options and choicesbased on practical ethical analysis. 相似文献
142.
Menghan Li Yao Zhang Jiancheng Yang Xiaori Liu Zhenguo Li Qiang Zhang 《环境科学学报(英文版)》2021,33(5):157-171
Selective catalytic reduction is the most efficient and reliable equipment for NOx control in current diesel engines. However, the issue of urea crystallization becomes increasingly serious with the implement of the new emissions standards. In this paper, urea deposit samples collected from engine test bed and tube furnace were characterized by thermogravimetric analysis and Fourier transform-infrared analysis to aid the comprehension of urea deposit formation. Moreover, thermogravimetric tests were conducted to disclose the effects of catalyst on the thermal decomposition processes of urea deposit. The results indicated that less temperature resistant species are formed in the engine test bed than in the tube furnace at conditions with the same temperatures. The main compositions in the World Harmonized Transient Cycle (WHTC) urea deposits are urea, cyanuric acid (CYA) and ammelide, implying that accelerating the decomposition of these species could prevent the accumulation of urea deposit. CuWTi, Cuβ and CuZSM catalysts could lead to increased yield of CYA during pure urea thermolysis. Cuβ, CuWTi and VWTi catalysts tend to promote the thermolysis of CYA while VWTi has the most significant catalytic effects on the thermal decomposition of ammelide and ammeline. 相似文献
143.
选择性沉淀法处理含镍氯化铁废液 总被引：4，自引：0，他引：4
研究了选择性沉淀法处理含镍氮化铁废液的工艺条件，结果表明，采用该工艺可再生三氯化铁腐蚀剂并上镍盐，Ｆｅｃｌ３含量达４４％以上，含镍量为２～４ｇ／Ｌ，镍回收率为８２％－８６％，处理后出水达排放。 相似文献
144.
《环境科学学报(英文版)》2023,35(7):115-127
The selective recovery of copper from strongly acidic wastewater containing mixed metal ions remains a significant challenge. In this study, a novel reagent zinc dimethyldithiocarbamate (Zn(DMDC)2) was developed for the selective removal of Cu(II). The removal efficiency of Cu(II) reached 99.6% after 120 min reaction at 30°C when the mole ratio Zn(DMDC)2/Cu(II) was 1:1. The mechanism investigation indicates that the Cu(DMDC)2 products formed as a result of the displacement of Zn(II) from the added Zn(DMDC)2 by Cu(II) in wastewater, due to the formation of stronger coordination bonds between Cu(II) and the dithiocarbamate groups of Zn(DMDC)2. Subsequently, we put forward an innovative process of resource recovery for strongly acidic wastewater. Firstly, the selective removal of Cu(II) from actual wastewater using Zn(DMDC)2, with a removal efficiency of 99.7%. Secondly, high-value CuO was recovered by calcining the Cu(DMDC)2 at 800°C, with a copper recovery efficiency of 98.3%. Moreover, the residual As(III) and Cd(II) were removed by introducing H2S gas, and the purified acidic wastewater was used to dissolve ZnO for preparation of valuable ZnSO4·H2O. The total economic benefit of resource recovery is estimated to be 11.54 $/m3. Accordingly, this study provides a new route for the resource recovery of the treatment of copper-containing acidic wastewater. 相似文献
145.
Selective catalytic reduction (SCR) denitration may increase the emission of NH4+ and NH3. The removal and transformation characteristics of ammonium sulfate aerosols and ammonia slip during the wet flue gas desulfurization (WFGD) process, as well as the effect of desulfurization parameters, were investigated in an experimental system equipped with a simulated SCR flue gas generation system and a limestone-based WFGD system. The results indicate that the ammonium sulfate aerosols and ammonia slip in the flue gas from SCR can be partly removed by slurry scrubbing, while the entrainment and evaporation of desulfurization slurry with accumulated NH4+ will generate new ammonium-containing particles and gaseous ammonia. The ammonium-containing particles formed by desulfurization are not only derived from the entrainment of slurry droplets, but also from the re-condensation of gaseous ammonia generated by slurry evaporation. Therefore, even if the concentration of NH4+ in the desulfurization slurry is quite low, a high level of NH4+ was still contained in the fine particles at the outlet of the scrubber. When the accumulated NH4+ in the desulfurization slurry was high enough, the WFGD system promoted the conversion of NH3 to NH4+ and increased the additional emission of primary NH4+ aerosols. With the decline of the liquid/gas ratio and flue gas temperature, the removal efficiency of ammonia sulfate aerosols increased, and the NH4+ emitted from entrainment and evaporation of the desulfurization slurry decreased. In addition, the volatile ammonia concentration after the WFGD system was reduced with the decrease of the NH4+ concentration and pH values of the slurry. 相似文献
146.
车用柴油机选择性催化还原技术研究进展 总被引：2，自引：0，他引：2
选择性催化还原技术(SCR)是目前唯一可以同时改善柴油机排放和燃油经济性的氮氧化物(NOX)净化技术,而以NH3作为还原剂的SCR技术(NH3-SCR)又是目前最成熟,最具推广前景的SCR技术。文章详细阐述了用于车用柴油机的NH3-SCR技术的反应机理,介绍了温度对SCR反应的影响;列举了典型SCR系统的主要部件并介绍了各部分的功能,以及法规中对车用尿素水溶液(AdBlue)主要指标的规定;总结了目前应用较多的开环、闭环两种控制策略的工作流程及特点,并且分析了各自的优缺点;在柴油机后处理系统集成的角度对SCR与颗粒捕集器(DPF)的两种整合方案进行了分析,对比了两种方案的优缺点;最后分析了SCR技术目前存在的几个问题。 相似文献
147.
Ion-exchange polymer and modified carbonization bacterial cellulose(CBC) electrodes were fabricated using varying amounts of cation-exchange polymers(glutaric acid(GA) and sulfosuccinic acid(SSA)) and assembled within an asymmetric capacitive deionization unit(p-CDI).The performance of selective NO2-electro-adsorption was studied.The AC/CBCSSA group showed a better salt adsorption capacity(14.56 mg/g) and nitrite removal efficiency(71.01%) than the AC/CBC-GA(10.72 mg/g,47.8... 相似文献
148.
The development of bio-adsorbents with highly selective immobilization properties for specific heavy metals is a great challenge,but has important application value.Biogenic whewellite(BW)with high selectivity for Pb(Ⅱ)was synthesized by mineral microbial trans-formation.The selective immobilization properties and mechanism of BW for Pb(Ⅱ)were analyzed by combining mineral characterization technology and batch adsorption research methods.The results indicated that BW can efficiently and selectively immobilize Pb(Ⅱ)in single or composite heavy metal adsorption solutions,and the immobilized Pb(Ⅱ)is dif-ficult to desorb.BW undergoes monolayer adsorption on Pb(Ⅱ),Qmax≈1073.17 mg/g.The immobilization of Pb(Ⅱ)by BW is a physico-chemical adsorption process with spontaneous heat absorption and an accompanying increase in entropy.In addition,the sequestration of Pb(Ⅱ)by BW remains around 756.99 mg/g even at pH=1.The excellent selective im-mobilization properties of BW for Pb(Ⅱ)are closely related to its smaller Ksp,electrostatic repulsion effect,organic-inorganic composite structure,acid resistance and the formation of Pb(Ⅱ)oxalate.This study provides beneficial information about the recycling of lead in acidic lead-containing wastewater and composite heavy metal contaminated water bodies. 相似文献
149.
Ping Chen Yalan Wang Xiaoqin Zhuang Haijin Liu Guoguang Liu Wenying Lv 《环境科学学报(英文版)》2023,35(2):268-280
Zr-based metal-organic frameworks(MOFs) have been developed in recent years to treat heavy metals,e.g.hexavalent chromium Cr6+ pollution,which damages the surrounding ecosystem and threaten human health.This kind of MOF is stable and convenient to prepare,but has the disadvantage of low adsorption capacity,limiting its wide application.To this end,a novel formic acid and amino modified MOFs were prepared,referred to as FormUiO-66-NH2.Due to the modification of formic acid,i... 相似文献
150.
Following intense overfishing in the 1970s, the western stock of Atlantic bluefin tuna (Thunnus thynnus) experienced a long period of depressed abundance, which has been attributed to failure of the population to periodically produce large numbers of juveniles, the western stock mixing with the more highly exploited eastern stock (fisheries in the Northeast Atlantic Ocean and Mediterranean Sea), and regime shift in the population's ecosystem resulting in lower replacement rates. To evaluate the presence of relatively strong years of juvenile production, we analyzed age structure from a recent sample of otoliths (ear stones) collected from the western stock (2011–2013, North Carolina, U.S.A., winter fishery). Mixing levels for the recent sample were analyzed using otolith stable isotopes to test whether age structure might be biased through immigration of eastern stock bluefin tuna. Age structure from historical samples collected from United States and Canadian fisheries (1975–1981) was compared with more recent samples (1996–2007) to examine whether demographic changes had occurred to the western stock that might have disrupted juvenile production. Relatively high juvenile production occurred in 2003, 2005, and 2006. Otolith stable isotope analysis showed that these recruitments were mostly of western stock origin. However, these high recruitments were >2‐fold less than historical recruitment. We found substantial age truncation in the sampled fisheries. Half the historical sample was >20 years old (mean age = 20.1 [SD 3.7]; skewness = ?0.3), whereas <5% of the recent sample was >20 years old (mean age = 13.4 [SD 3.8]; skewness = 1.3). Loss of age structure is consistent with changes in fishing selectivity and trends in the stock assessment used for management. We propose that fishing, as a forcing variable, brought about a threshold shift in the western stock toward lower biomass and production, a shift that emulates the regime shift hypothesis. An abbreviated reproductive life span compromised resilience by reducing the period over which adults spawn and thereby curtailing the stock's ability to sample year‐to‐year variability in conditions that favor offspring survival (i.e., storage effect). Because recruitment dynamics by the western stock exhibit threshold dynamics, returning it to a higher production state will entail greater reductions in exploitation rates. 相似文献