全文获取类型
收费全文 | 215篇 |
免费 | 29篇 |
国内免费 | 1篇 |
专业分类
综合类 | 11篇 |
化学工业 | 67篇 |
金属工艺 | 4篇 |
机械仪表 | 2篇 |
建筑科学 | 22篇 |
矿业工程 | 46篇 |
能源动力 | 6篇 |
轻工业 | 2篇 |
水利工程 | 1篇 |
石油天然气 | 9篇 |
一般工业技术 | 19篇 |
冶金工业 | 44篇 |
原子能技术 | 1篇 |
自动化技术 | 11篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 7篇 |
2015年 | 10篇 |
2014年 | 2篇 |
2013年 | 12篇 |
2012年 | 16篇 |
2011年 | 20篇 |
2010年 | 19篇 |
2009年 | 26篇 |
2008年 | 21篇 |
2007年 | 12篇 |
2006年 | 16篇 |
2005年 | 13篇 |
2004年 | 6篇 |
2003年 | 8篇 |
2002年 | 4篇 |
2001年 | 1篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有245条查询结果,搜索用时 25 毫秒
31.
Degradation of DMSO by ozone-based advanced oxidation processes 总被引:2,自引:0,他引:2
The present study investigates the oxidation of dimethyl sulfoxide (DMSO) by conventional ozonation and the advanced oxidation processes (AOPs). The major degradation products identified were methanesulfinate, methanesulfonate, formaldehyde, and formic acid in ozonation process. The subsequent degradation of intermediates shows that methanesulfonate is more resistance to ozonation, which reduces the mineralization rate of DMSO. The effect of t-butanol addition and ozone gas flow dosage on the degradation rate was evaluated. The rate constant of the reaction of ozone (k(D)) with DMSO was found to be 0.4162 M(-1)S(-1). In the second part of this study, DMSO degradation and TOC mineralization were investigated using O(3)/UV, O(3)/H(2)O(2) and UV/H(2)O(2) processes. In all theses processes the degradation of target organics is more pronounced than TOC removal. The efficiencies of these processes were evaluated and discussed. The formation of sulfate ion in all AOPs have been identified and compared with other processes. Overall it can be concluded that ozonation and ozone-based AOPs are promising processes for an efficient removal of DMSO in wastewater. 相似文献
32.
湘西花垣民乐锰矿床属沉积型碳酸锰矿床,地层古构造、岩相古地理、古气候、古生物和地球化学等诸因素决定其成矿机理。文章对该矿床地质特征、成矿条件和成矿物质来源进行了论述。 相似文献
33.
胶西北金矿集中区的控矿作用与深部过程密切相关。华北东部地区在经历了古生代漫长的稳定地台演化阶段后,于燕山运动时期进入了地幔热柱演化阶段,而胶西北成矿集中区则进入了以莱阳地幔亚热柱与其外围郭家店幔枝构造的发展演化阶段。核幔源Au元素以气—液的形式,经过地幔热柱—地幔亚热柱—幔枝构造—有利构造扩容带,迁移到幔枝构造的有利部位集聚成矿,从而构成了环绕郭家岭幔枝构造的一系列大、中型金矿床。同时,提出了焦家断裂为幔枝构造北西缘的主拆离(断裂蚀变岩)带,三山岛断裂是拆离带上盘铲状断裂的基本认识,并据此指出了该区进一步找矿方向。 相似文献
34.
祁雨沟金矿床为典型的角砾岩型金矿床,J 4角砾岩体是祁雨沟金矿区最重要的角砾岩体之一。重点阐述了J 4角砾岩体的地质特征,总结了矿化富集规律,为在河南省嵩县地区角砾岩型金矿床的找矿勘查工作提供了依据。 相似文献
35.
矿区位于滇黔川铅锌成矿区之巧家-金沙厂成矿带之上,处于金沙厂、茂租-东坪两大矿化集中区之间。区内震旦系灯影组上部硅质条带白云岩、顶部含藻白云岩为矿区赋矿地层,矿体呈似层状、透镜状及沿断裂带呈脉状产于以上地层中,其控矿因素为地层-岩性(相)-构造。找矿标志为灯影组上部、顶部的硅质条带白云岩、含藻白云岩,莲峰-茂租区域控矿断裂上盘和旁侧的次级断裂,相应的围岩蚀变发育的地区(段)。 相似文献
36.
37.
Zhixi Gan Zheng Cui Hairong Yue Siyang Tang Changjun Liu Chun Li Bin Liang Heping Xie 《中国化学工程学报》2016,24(11):1541-1551
The issues of reducing CO2 emissions, sustainably utilizing natural mineral resources, and dealing with industrial waste offer challenges for sustainable development in energy and the environment. We propose an efficient methodology via the co-reaction of K-feldspar and phosphogypsum for the extraction of soluble potassium salts and recovery of SO2 with reduced CO2 emission and energy consumption. The results of characterization and reactivity evaluation indicated that the partial melting of K-feldspar and phosphogypsum in the high-temperature co-reaction significantly facilitated the reduction of phosphogypsum to SO2 and the exchange of K+(K-feldspar) with Ca2+(CaSO4 in phosphogypsum). The reaction parameters were systematical y investigat-ed with the highest sulfur recovery ratio of~60%and K extraction ratio of~87.7%. This novel methodology possesses an energy consumption reduction of~28%and CO2 emission reduction of~55%comparing with the present typical commercial technologies for utilization of K-feldspar and the treatment of phosphogypsum. 相似文献
38.
Satoshi Horikoshi Takashi Miura Masatsugu Kajitani Natsuko Horikoshi Nick Serpone 《Applied catalysis. B, Environmental》2008,84(3-4):797-802
The photoassisted degradation (HPLC-UV absorption), dehalogenation (HPLC-IC) and mineralization (TOC decay) of the flame retardants tetrabromobisphenol-A (TBBPA) and tetrachlorobisphenol-A (TCBPA) were examined in UV-irradiated alkaline aqueous TiO2 dispersions (pH 12), and for comparison the parent bisphenol-A (BPA, an endocrine disruptor) in pH 4–12 aqueous media to assess which factor impact most on the photodegradative process. Complete degradation (2.7–2.8 × 10−2 min−1) and dehalogenation (1.8 × 10−2 min−1) of TBBPA and TCBPA occurred within 2 h of UV irradiation, whereas only 45–60% mineralization (2.3–2.7 × 10−3 min−1) was complete within 5 h for the flame retardants at pH 12 and ca. 80% for the parent BPA. Factors examined in the pH range 4–12 that impact the degradation of BPA were the point of zero charge of TiO2 particles (pHpzc; electrophoretic method), particle or aggregate sizes of TiO2 (light scattering), and the relative number of OH radicals (as DMPO–OH adducts; ESR spectroscopy) produced in the UV-irradiated dispersion. Dynamics of BPA degradation (2.0–2.4 × 10−2 min−1) were pH-independent and independent of particle/aggregate size, but did correlate with the number of OH radicals, at least at pHs 4 to 8–9, after which the rates decreased somewhat at pH > 9 with decreasing adsorption owing to Coulombic repulsive forces between the very negative TiO2 surface and the anionic forms of BPA (pKas ca. 9.6–11.3), even though the number of OH radicals continued to increase at the higher pHs. 相似文献
39.
40.
Mineralization of flumequine in acidic medium by electro-Fenton and photoelectro-Fenton processes 总被引:1,自引:0,他引:1
Garcia-Segura S Garrido JA Rodríguez RM Cabot PL Centellas F Arias C Brillas E 《Water research》2012,46(7):2067-2076
The mineralization of flumequine, an antimicrobial agent belonging to the first generation of synthetic fluoroquinolones which is detected in natural waters, has been studied by electrochemical advanced oxidation processes (EAOPs) like electro-Fenton (EF) and photoelectro-Fenton (PEF) with UVA light. The experiments were performed in a cell containing a boron-doped diamond (BDD) anode and an air-diffusion cathode to generate H2O2 at constant current. The Fe2+ ion added to the medium increased the solubility of the drug by the formation of a complex of intense orange colour and also reacted with electrogenerated H2O2 to form hydroxyl radical from Fenton reaction. Oxidant hydroxyl radicals at the BDD surface were produced from water oxidation. A partial mineralization of flumequine in a solution near to saturation with optimum 2.0 mM Fe2+ at pH 3.0 was achieved by EF. The PEF process was more powerful, giving an almost total mineralization with 94-96% total organic carbon removal. Increasing current accelerated both treatments, but with decreasing mineralization current efficiency. Comparative treatments using a real wastewater matrix led to similar degradation degrees. The kinetics for flumequine decay always followed a pseudo-first-order reaction and its rate constant, similar for both EAOPs, raised with increasing current. Generated carboxylic acids like malonic, formic, oxalic and oxamic acids were quantified by ion-exclusion HPLC. Fe(III)-oxalate and Fe(III)-oxamate complexes were the most persistent by-products under EF conditions and their quicker photolysis by UVA light explains the higher oxidation power of PEF. The release of inorganic ions such as F−, NO3− and in lesser extent NH4+ was followed by ionic chromatography. 相似文献