全文获取类型
收费全文 | 1546篇 |
免费 | 26篇 |
国内免费 | 27篇 |
专业分类
电工技术 | 10篇 |
综合类 | 24篇 |
化学工业 | 599篇 |
金属工艺 | 107篇 |
机械仪表 | 25篇 |
建筑科学 | 19篇 |
矿业工程 | 61篇 |
能源动力 | 386篇 |
轻工业 | 11篇 |
水利工程 | 1篇 |
石油天然气 | 7篇 |
无线电 | 36篇 |
一般工业技术 | 182篇 |
冶金工业 | 94篇 |
原子能技术 | 19篇 |
自动化技术 | 18篇 |
出版年
2024年 | 1篇 |
2023年 | 39篇 |
2022年 | 58篇 |
2021年 | 61篇 |
2020年 | 62篇 |
2019年 | 49篇 |
2018年 | 46篇 |
2017年 | 50篇 |
2016年 | 28篇 |
2015年 | 15篇 |
2014年 | 69篇 |
2013年 | 64篇 |
2012年 | 38篇 |
2011年 | 142篇 |
2010年 | 109篇 |
2009年 | 109篇 |
2008年 | 110篇 |
2007年 | 93篇 |
2006年 | 68篇 |
2005年 | 60篇 |
2004年 | 48篇 |
2003年 | 34篇 |
2002年 | 35篇 |
2001年 | 29篇 |
2000年 | 30篇 |
1999年 | 30篇 |
1998年 | 19篇 |
1997年 | 25篇 |
1996年 | 19篇 |
1995年 | 8篇 |
1994年 | 14篇 |
1993年 | 11篇 |
1992年 | 9篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有1599条查询结果,搜索用时 15 毫秒
31.
电化学法处理废硬质合金直接回收金属钴和碳化钨 总被引:4,自引:0,他引:4
首次采用电化学法处理废硬质合金直接回收金属钴和碳化钨,工艺简单可靠,具有较好的环境和经济效益。 相似文献
32.
DMTAM光度法同时测定钯和钴 总被引:1,自引:0,他引:1
以硫脲作为掩蔽剂,在pH3.75~5.0的HAc—NaAc缓冲介质中,Pd、Co(Ⅱ)和DMTAM均能形成稳定的1∶2型配合物,其表观摩尔吸光系数分别为ε_(Pd)=6.14×10~4,ε_(Co)=6.20×10~4,遵守比尔定律的线性范围分别为Pd0~35μg/25ml,Co0~15μg/25ml。研究了30余种共存离子的影响。可应用于分子筛和矿样中Pd、Co的同时测定。 相似文献
33.
I. Povstugar C. H. Zenk R. Li S. Neumeier O. Dolotko 《Materials Science & Technology》2016,32(3):220-225
Novel Cr containing Co-Al-W base superalloys were studied by atom probe tomography and neutron diffraction. Cr is found to predominantly partition to the γ matrix and decrease partitioning of W to γ′. Furthermore, Cr significantly enhances the γ′ volume fraction, decreases the γ/γ′ lattice misfit and deteriorates the creep resistance. Addition of Ni to the Cr containing alloys affects partitioning of W and Al, further decreases the lattice misfit and results in the formation of irregularly shaped precipitates. Al, W and Cr tend to occupy the ‘B'sublattice in the γ′-A3B phase (L12 type), while Co and Ni reside in the ‘A' sublattice. 相似文献
34.
《材料科学技术学报》2019,35(8):1797-1802
A new insight into the promotion action of Co2+ on both particle and metal deposition in Ni-diamond composite electrodeposition system was analyzed according to electrochemical measurements. The results showed that the addition of Co2+ made particles content in deposits increased remarkably. The change of particles content in deposits was related inversely to the change of cathodic zero potential with the increase of the concentration of cobalt sulfate. Zero charge potential of cathode was shifted to much more negative region. The negative shift of the zero potential, combining with positive shift of the zeta potential, increased the electrostatic force between the particle-adsorbed metallic cations and the cathode. It not only benefits to the transportation of particles in solution towards cathode, but also shortens their residence time on cathodic surface. Meanwhile, entry of particles is also promoted. For metals deposition, reduction resistance of metallic cations rises greatly and deposition current at cathodic potentiodynamic polarization decreases after cobalt sulfate has been added into electrolyte. These factors are favorable for increasing particles content in deposits. In addition, physical model of diamond particles deposition state before and after the addition of Co2+ has been discussed. 相似文献
35.
有机溶剂分离法处理废旧锂离子电池 总被引:10,自引:0,他引:10
针对现有废旧锂电池回收钴金属工艺中铝钴分离的问题,采用特定的有机溶剂分离法,使锂电池正极材料中的钴酸锂从铝箔上溶解下来,直接分离钴酸锂和铝箔,铝箔经清洗后直接回收,所用的有机溶剂通过蒸馏方式脱除粘结剂,实现循环使用。该工艺简化废旧锂电池正极材料的回收处理工艺流程,有效地回收钴与铝。 相似文献
36.
草酸钴的氧化条件对氧化钴及还原钴粉性能的影响 总被引:2,自引:1,他引:2
利用X-衍射、扫描电镜研究了草酸钴氧化温度对氧化产物、及其相应还原钴粉性能的影响。结果表明,氧化条件影响了钴粉的粒度,草酸钴直接还原的钴粉具有更小的粒度。 相似文献
37.
考察了硫酸钴体系沉淀法合成异辛酸钴工艺中皂化反应温度及皂化时间、复分解反应时间、物料比、水洗温度和搅拌速度等因素对合成的影响,确定了合成的最佳工艺条件,建立了水相中钴的回收利用新工艺和测定方法。将整个工艺应用于全流程小试试验中,可保证钴的转化率达96.5%以上。 相似文献
38.
陈浩 《武汉理工大学学报(材料科学英文版)》2003,18(3):30-32
1 IntroductionCobalt basedalloyiswidelyusedingasturbineair craftenginesandvalvespumpshaftsofpressurevessels[1,2 ] ,duetoitshighflowstressesandoutstandingresistancetooxidationandwearuptotemperaturesclosingtoitsmeltingpoint.Thehighsolidificationrateoflasercladdingtendstoresultinfinemicrostructures ,non equi libriumphasesandsupersaturatedsolidsolutions ,whichleadtohighhardnessandwearandcorrosionresi stance[3 -5] .However,crackingfrequentlyappearsinthelasercladdinglayerwhichlimitstheuseofthissurf… 相似文献
39.
O.V. Netskina E.S. Tayban V.A. Rogov A.M. Ozerova S.A. Mukha V.I. Simagina O.V. Komova 《International Journal of Hydrogen Energy》2021,46(7):5459-5471
Hydrogen generation from tablets of sodium borohydride with chlorides of nickel and cobalt was studied. The nickel catalysts were shown to be less active in the borohydride hydrolysis than the cobalt catalysts. One of the reasons for the lower activity of the nickel catalyst was the presence of hydrogen on its surface, which hampered the adsorption of reactants. The addition of cobalt to the nickel catalyst increases the hydrogen generation rate. This is due to the introduction of active metal with low adsorption capacity for hydrogen and the higher dispersion of the active component. 相似文献
40.
E. Papadopoulou D. Delimaris A. Denis A. Machocki T. Ioannides 《International Journal of Hydrogen Energy》2012
Co–MnO catalysts have been prepared by pyrolytic decomposition of the corresponding fumarate or gluconate salts and examined in the reactions of methanol and ethanol reforming. The synthesis parameters were the type of organic salt, the Co:Mn ratio and the temperature of decomposition. The decomposition pathway depends on the type of carboxylate, with the fumarate group being more stable than the gluconate. In-situ XRD measurements of salt decomposition showed that the reducing atmosphere prevailing during thermal treatment, as well as the presence of solid carbon, facilitates reduction of cobalt oxides towards metallic cobalt at temperatures above ∼500 °C. Thus, the reduced form of the catalyst, consisting mainly of metallic cobalt and MnO dispersed in a carbonaceous matrix can be prepared in a single step. It was found that reforming of both methanol and ethanol proceeds under comparable reaction conditions and hydrogen yield is maximized at temperatures of 400–450 °C. The activity of catalysts prepared under an inert atmosphere was considerably higher than the one of catalysts prepared through oxidative pre-treatment. 相似文献