全文获取类型
收费全文 | 2410篇 |
免费 | 59篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 10篇 |
综合类 | 2篇 |
化学工业 | 375篇 |
金属工艺 | 45篇 |
机械仪表 | 27篇 |
建筑科学 | 4篇 |
矿业工程 | 1篇 |
能源动力 | 74篇 |
轻工业 | 108篇 |
水利工程 | 5篇 |
石油天然气 | 11篇 |
无线电 | 77篇 |
一般工业技术 | 385篇 |
冶金工业 | 1251篇 |
原子能技术 | 7篇 |
自动化技术 | 89篇 |
出版年
2023年 | 17篇 |
2022年 | 32篇 |
2021年 | 35篇 |
2020年 | 43篇 |
2019年 | 27篇 |
2018年 | 49篇 |
2017年 | 50篇 |
2016年 | 40篇 |
2015年 | 43篇 |
2014年 | 50篇 |
2013年 | 99篇 |
2012年 | 89篇 |
2011年 | 101篇 |
2010年 | 57篇 |
2009年 | 57篇 |
2008年 | 55篇 |
2007年 | 64篇 |
2006年 | 32篇 |
2005年 | 34篇 |
2004年 | 20篇 |
2003年 | 31篇 |
2002年 | 21篇 |
2001年 | 11篇 |
2000年 | 10篇 |
1999年 | 47篇 |
1998年 | 336篇 |
1997年 | 198篇 |
1996年 | 140篇 |
1995年 | 103篇 |
1994年 | 80篇 |
1993年 | 89篇 |
1992年 | 18篇 |
1991年 | 21篇 |
1990年 | 25篇 |
1989年 | 25篇 |
1988年 | 34篇 |
1987年 | 34篇 |
1986年 | 16篇 |
1985年 | 18篇 |
1984年 | 7篇 |
1983年 | 12篇 |
1982年 | 13篇 |
1981年 | 20篇 |
1980年 | 19篇 |
1979年 | 3篇 |
1978年 | 7篇 |
1977年 | 42篇 |
1976年 | 85篇 |
1975年 | 4篇 |
1971年 | 2篇 |
排序方式: 共有2471条查询结果,搜索用时 15 毫秒
1.
Patil Rupesh C. Jagdale Ashutosh A. Patil Uttam P. Ghodake Jeevan S. Mali Sawanta S. Hong Chang K. Patil Suresh S. 《Catalysis Letters》2021,151(12):3617-3631
Catalysis Letters - We converted agro-waste Custard Apple Peels (CAP) to ash via thermal treatment, on which Pd(OAc)2 was immobilized easily that produced a low-cost, highly efficient Pd/CAP-ash... 相似文献
2.
3.
4.
Chammi Miller Badr S. Bageri Tongzhou Zeng Shirish Patil Kishore K. Mohanty 《Journal of surfactants and detergents》2020,23(6):1159-1167
In enhanced oil recovery applications, surfactants are injected into reservoirs along with polymers and salts. The effluents eluted from lab experiments and field tests are analyzed by HPLC methods using an evaporative light scattering detector (ELSD) detector. When the surfactant concentrations are less than 100 ppm, HPLC methods are inaccurate. A novel two-phase titration method is developed where surfactant concentrations can be quantified using a calibration curve constructed with UV/vis absorption. This method can analyze surfactant concentrations 5–80 ppm where dilution eliminates any high-salinity interferences with the absorption measurements. The method is based on formation of a dye-surfactant complex and the light absorption of the complex has a linear correlation with the surfactant concentration. Anionic surfactant concentrations lower than 100 ppm can be accurately quantified using this method with methylene blue. The method was also developed for low concentrations (<50 ppm) of cationic surfactants using methyl orange and indigo carmine. The indigo carmine method can be used without the use of an organic phase. All methods are applicable at salinities up to 3 wt%. Both the methylene blue method and the methyl orange method can be used to detect zwitterionic surfactants. These methods can be used in the presence of polymers without any prior treatments. 相似文献
5.
Patil Y. S. Salunkhe P. H. Navale Y. H. Patil V. B. Ubale V. P. Ghanwat A. A. 《Polymer Bulletin》2020,77(5):2205-2226
Polymer Bulletin - 2,5-Bis(4-(2-aminothiazole) phenyl)-3 and 4-diphenyltetraphenyl thiophene (TPTPThDA) are fine processed in three steps. A series of polyazomethines containing... 相似文献
6.
7.
Shailesh J. Patil 《Chemical Engineering Communications》2019,206(5):605-618
Jatropha oil is a promising nonedible feedstock for producing renewable diesel. In this work, the hydrotreatment processing of jatropha oil was investigated. Instead of using conventional alumina-supported Co–Mo, Ni–Mo, and Ni–W catalysts that need sulfidation pretreatment, noble metals such as Pd and Ru were chosen. Trials were performed in an isothermal trickle-bed reactor and the reaction conditions were as follows: temperature 603–663?K, weight hourly space velocity (WHSV) 1 to 4/h, pressure 1.5–3?MPa, and H2/oil ratio 200–800 (v/v). Yield of n-C15 to n-C18 hydrocarbons was maximized (70.3 and 43.8% for Pd/Al2O3 and Ru/Al2O3, respectively) at the following conditions: T?=?663 K, WHSV?=?2/h, P?=?3?MPa, and H2/oil ratio?=?600 (v/v). Since Ru favored cracking reactions to a larger extent than Pd, the yield of C15 to C18 hydrocarbons over Ru/Al2O3 was lowered. Using simple first-order plots for oil conversion, activation energies for the hydrotreating process over Pd/Al2O3 and Ru/Al2O3 were found and they were equal to 109 and 121?kJ/mol, correspondingly. 相似文献
8.
Sanjeev Kumar Pandey S. L. Patil Praveen V. Pol S. B. Phadke 《International Journal of Electronics》2020,107(10):1682-1703
ABSTRACT In this paper, two control schemes for boost converters affected by uncertainties in input voltage and load are proposed. The boost converter dynamics is redefined in terms of new state variables to facilitate the use of a disturbance observer that can estimate matched and unmatched disturbances. A sliding surface, which is new in the context of boost converters, is proposed to enable tracking and regulation of output voltage without requiring measurement of input voltage and load current. The stability of the overall system including the disturbance observer, the sliding variable and the output is proved. The performance of the schemes is assessed for regulation of output voltage and tracking of reference voltage by simulation as well as experimentation in which various types of uncertainties and various types of reference voltages are considered. 相似文献
9.
Abhinav Sharma Yashodhan Patil Ravi Krishnaiah PhD B. Ashok PhD Akhil Garg PhD Liang Gao PhD 《亚洲传热研究》2020,49(8):4626-4656
Lithium-ion cells are preferred in the electrical powertrain due to high-power density, compactness, and modularity. In real driving conditions, the cells undergo discharge rates as high as 4 C resulting in high heat generation affecting the performance. To obtain the maximum performance the pack construction and thermal management of cells are crucial parameters. In our work, air-cooled technique with diverse air inlet and staggered scheme with a two-channel partition approach for thermal management of the cylindrical lithium-ion cells are studied in computational fluid dynamics. The simulation model is validated with experimental results. The obtained results demonstrate that the cells in the dual-directional air inlet arrangement had low maximum temperature difference among and within the cells and required least fan work. This arrangement required least fan work to generate optimal air inlet velocity of 2 m/s for 1, 2, and 3 C and 4 m/s for 4 C discharge rates. There is a reduction of 50% and 33% fan work for 3 and 4 C discharge rates, which are the majority operating points. Also, it shows that the temperature uniformity within the cells has improved. The results of this study can used to optimize parameters for designing an enhanced thermal management system. 相似文献
10.
In this study, the stagnation point flow of a magnetized Williamson fluid past a stretching sheet in the presence of nonlinear thermal radiation and buoyancy effect is studied. The present situation is remodeled using similarity transformation that transforms the flow model of partial differential equations into the set of nonlinear ordinary differential equations. The fourth-order Runge-Kutta scheme and shooting method are employed to solve these reduced equations. The effects of various associated parameters over the velocity and temperature profiles are plotted and the outcome of each associated parameter is discussed through graphs. The key findings are noted as follows: the velocity profile declines with an increase in the magnetic force number, and an increment in buoyancy parameter leads to the increase in the boundary layer thickness and decrease in the thickness of the thermal boundary layer. 相似文献