全文获取类型
收费全文 | 714篇 |
免费 | 4篇 |
国内免费 | 8篇 |
专业分类
综合类 | 23篇 |
化学工业 | 274篇 |
金属工艺 | 11篇 |
机械仪表 | 10篇 |
建筑科学 | 12篇 |
矿业工程 | 1篇 |
能源动力 | 100篇 |
轻工业 | 87篇 |
水利工程 | 3篇 |
石油天然气 | 8篇 |
武器工业 | 1篇 |
无线电 | 63篇 |
一般工业技术 | 122篇 |
冶金工业 | 3篇 |
原子能技术 | 3篇 |
自动化技术 | 5篇 |
出版年
2023年 | 10篇 |
2022年 | 25篇 |
2021年 | 20篇 |
2020年 | 15篇 |
2019年 | 15篇 |
2018年 | 16篇 |
2017年 | 24篇 |
2016年 | 22篇 |
2015年 | 15篇 |
2014年 | 30篇 |
2013年 | 49篇 |
2012年 | 33篇 |
2011年 | 44篇 |
2010年 | 41篇 |
2009年 | 59篇 |
2008年 | 31篇 |
2007年 | 29篇 |
2006年 | 28篇 |
2005年 | 21篇 |
2004年 | 24篇 |
2003年 | 17篇 |
2002年 | 25篇 |
2001年 | 26篇 |
2000年 | 21篇 |
1999年 | 17篇 |
1998年 | 15篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 11篇 |
1994年 | 7篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1985年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有726条查询结果,搜索用时 0 毫秒
1.
《International Journal of Hydrogen Energy》2022,47(81):34387-34396
This work develops a novel magnetic photocatalysts ZnO/SrFe12O19 (ZS) synthesized with hydrothermal process. The introduction of SrFe12O19 not only enhances the photocatalytic behavior of ZnO towards Rhodamine B (RhB) decomposition, but also reinforces the recycling stability. Especially, ZS-5 composite exhibits the optimal photocatalytic performance, and the RhB decomposition reaches 99.5% after being exposed to simulative sunlight for 70 min, which is obviously superior to that of bare ZnO. Furthermore, the ZS-5 can be recovered from RhB solution by an extra magnet space and reused. After five recycles, the RhB removal efficiency can still be maintained over 90%. Such prominent photocatalytic property and stability of ZS-5 are associated with the greatly improved detachment efficiency of photoexcited carriers in a magnetic field. This study could provide a new-type recyclable photocatalyst that can effectively purify dye wastewater for convenient recovery. 相似文献
2.
Chaozhong Sun Xiaoying Guo Rui Ji Changzheng Hu Laijun Liu Liang Fang Zhenxiang Cheng Nengneng Luo 《Ceramics International》2021,47(4):5038-5043
The triboelectric effect has recently demonstrated its great potential in environmental remediation and even new energy applications for triggering a number of catalytic reactions by utilizing trivial mechanical energy. In this study, Ba4Nd2Fe2Nb8O30 (BNFN) submicron powders were used to degrade organic dyes via the tribocatalytic effect. Under the frictional excitation of three PTFE stirring rods in a 5 mg/L RhB dye solution, BNFN demonstrates a high tribocatalytic degradation efficiency of 97% in 2 h. Hydroxyl radicals (?OH) and superoxide radicals (?O2-) were also detected during the catalysis process, which proves that triboelectric energy stimulates BNFN to generate electron-hole pairs. The tribocatalysis of tungsten bronze BNFN submicron powders provides a novel and efficient method for the degradation of wastewater dye by utilizing trivial mechanical energy. 相似文献
3.
《Advanced Powder Technology》2022,33(11):103777
In this study the constructional modification of Graphitic carbon nitride nanosheet (GCN-ns) has been made with the aid of ZnCr layered double hydroxide (ZC-LDH) in a unique 2D-2D structure to enhance its visible light absorption. Optical and morphological study presents successful incorporation of ZC-LDH on the surface of GCN-ns. Through adjusting of GCN-ns by ZC-LDH lower recombination rate of e?/h+ pairs, longer lifetimes and an increase in contamination reduction was brought out. The binary nanocomposite was employed to effectively degrade Rhodamine B under UV/vis light irradiation. The improvement in photocatalytic abilities was proven to be related to in situ self-production of H2O2 on GCN-ns/ZC-LDH surface by Xe light irradiation which in return accounts for additional hydroxide radical generation. Radical quenching experiments specified the main active species involved while the consequent step-scheme (S-scheme) charge transfer mechanism was proposed. 相似文献
4.
Anton Demirev 《臭氧:科学与工程》2005,27(6):475-485
The ozonation of two differently substituted azo dyes (Schwarz GRS and Orange Acid 8) in water media is studied. The influence of pH on the effectiveness of the ozonation at various initial concentrations of each dye is explored. It was found out that the rates of decolorization for amino-group substituted dyes reflect the considerable influence by the widely varying initial pH from 4.5 to 10. Specifically, the highest effect of decolorization of this dye was obtained at the highest pH studied (pH 10) for all initial concentrations of the solutions. Considering the dye without an amino-group substitute, the rates of color disappearance in ozonation reflected to a lower degree the variations of the initial pH. Pseudo-first-order trends of decolorization were observed in all the experimental runs. Regarding the kinetic results obtained, an attempt to explain the different dyes reactivity was made based on the absolute electronegativity (Elumo + Ehomo) of both dyes. The COD/BOD analysis shows that the ozonation of both azo dyes can reduce the sample COD but it could not improve the biodegradability ratio (BOD5/COD). BOD decrease with ozonation time indicates that the intermediates of the ozonation are of lower biodegradability. Oxalic acid was found as the final product of ozonation of both dyes. 相似文献
5.
Young Sil Jeon Jing Lei Ji-Heung Kim 《Journal of Industrial and Engineering Chemistry》2008,14(6):726-731
This study examined the removal of some basic dyes, such as Methylene Blue, Malachite Green and Methyl Orange, using alginate or alginate/polyaspartate composite gel beads. The adsorption of dyes from aqueous solutions at 25 °C was examined using a batch sorption technique. The effects of CaCl2 and the dye concentration on the adsorption were examined. Type-S adsorption isotherms were obtained, which is characteristic of a weak solute–solid interaction. The ionic interaction between the dye molecule and gel matrix appears to be responsible for the efficient adsorption of cationic dyes in this system. These results suggest that an alginate/polyaspartate gel can be used as an effective sorbent for water pollutants such as dyes, and the immobilization of these organic contaminants in the hydrogels from wastewater can solve one of the most important environmental problems in the related industry. 相似文献
6.
7.
介绍了均三甲苯胺的合成工艺、反应机理、国内外产品的质量指标、提高质量与收率的途径,并对产品的应用作了讨论。 相似文献
8.
9.
纺织品印染后整理剂Fs系多羟基多胺的阳离子树脂型缩合物,不含游离甲醛。本文介绍了纺织品印染后整理剂Fs的合成方法和应用条件。 相似文献
10.
Song Wang 《Electrochimica acta》2007,53(4):1883-1889
Nanocrystalline TiO2 films are widely investigated as the electrodes of dye-sensitized solar cell(s) with different preparation methods. In this paper, thin titanium dioxide films have been prepared on titanium plates by the micro-plasma oxidation method in the sulfuric acid solution. The thin TiO2 films were sensitized with a cis-RuL2(SCN)2·2H2O (L = cis-2,2′-bipyridine-4,4′-dicarboxylic acid) ruthenium complex and implemented into a dye-sensitized solar cell configuration. The influence of reaction current density (10, 15, 20, 25 and 30 A dm−2) on the structural and the surface morphology of the films was investigated by X-ray diffraction, scanning electron microscopy, atom force microscopy and X-ray photoelectricity spectroscopy. Impedance analysis for dye-sensitized solar cells was carried out by electrochemical impedance spectroscopy. The results show that the rise of current density leads to the increase in the amount of rutile and the thickness of the TiO2 film, which makes the TiO2 films have different photovoltages and photocurrents. The relatively higher photoelectricity properties were obtained in the TiO2 films prepared at a current density of 20 A dm−2. The open-circuit voltage and the short-circuit current are 605 mV and 165 μA cm−2, respectively. 相似文献