全文获取类型
收费全文 | 100045篇 |
免费 | 8717篇 |
国内免费 | 4004篇 |
专业分类
电工技术 | 5473篇 |
技术理论 | 8篇 |
综合类 | 8718篇 |
化学工业 | 16895篇 |
金属工艺 | 3232篇 |
机械仪表 | 2818篇 |
建筑科学 | 14695篇 |
矿业工程 | 5264篇 |
能源动力 | 7164篇 |
轻工业 | 5440篇 |
水利工程 | 18903篇 |
石油天然气 | 7936篇 |
武器工业 | 280篇 |
无线电 | 1670篇 |
一般工业技术 | 5313篇 |
冶金工业 | 5266篇 |
原子能技术 | 1352篇 |
自动化技术 | 2339篇 |
出版年
2024年 | 144篇 |
2023年 | 1095篇 |
2022年 | 2140篇 |
2021年 | 2678篇 |
2020年 | 2890篇 |
2019年 | 2422篇 |
2018年 | 2289篇 |
2017年 | 2835篇 |
2016年 | 3266篇 |
2015年 | 3240篇 |
2014年 | 6188篇 |
2013年 | 6098篇 |
2012年 | 7603篇 |
2011年 | 7739篇 |
2010年 | 5693篇 |
2009年 | 5946篇 |
2008年 | 5160篇 |
2007年 | 6857篇 |
2006年 | 6425篇 |
2005年 | 5752篇 |
2004年 | 4593篇 |
2003年 | 4157篇 |
2002年 | 3608篇 |
2001年 | 2894篇 |
2000年 | 2373篇 |
1999年 | 1809篇 |
1998年 | 1309篇 |
1997年 | 1082篇 |
1996年 | 837篇 |
1995年 | 807篇 |
1994年 | 587篇 |
1993年 | 443篇 |
1992年 | 337篇 |
1991年 | 272篇 |
1990年 | 205篇 |
1989年 | 208篇 |
1988年 | 123篇 |
1987年 | 139篇 |
1986年 | 102篇 |
1985年 | 106篇 |
1984年 | 108篇 |
1983年 | 71篇 |
1982年 | 44篇 |
1981年 | 13篇 |
1980年 | 21篇 |
1979年 | 17篇 |
1978年 | 4篇 |
1977年 | 8篇 |
1976年 | 5篇 |
1951年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
《International Journal of Hydrogen Energy》2022,47(43):18587-18596
The development of cost-effective bifunctional catalysts with excellent performance and good stability is of great significance for overall water splitting. In this work, NiFe layered double hydroxides (LDHs) nanosheets are prepared on nickel foam by hydrothermal method, and then Ni2P(O)–Fe2P(O)/CeOx nanosheets are in situ synthesized by electrodeposition and phosphating on NiFe LDHs. The obtained self-supporting Ni2P(O)–Fe2P(O)/CeOx exhibit excellent catalytic performances in alkaline solution due to more active sites and fast electron transport. When the current density is 10 mA cm?2, the overpotential of hydrogen evolution reaction and oxygen evolution reaction are 75 mV and 268 mV, respectively. In addition, driven by two Ni2P(O)–Fe2P(O)/CeOx electrodes, the alkaline battery can reach 1.45 V at 10 mA cm?2. 相似文献
22.
《International Journal of Hydrogen Energy》2022,47(61):25511-25521
Metal/carbon composite materials are highly promising electrocatalysts for water electrolysis. In this work, three composites of metal cobalt nanoparticles highly dispersed in N-doped carbon materials were facilely constructed by pyrolysis of different phenylenediamine based Schiff base-Co complexes (PDBs). Interestingly, the composites derived from PDBs based on different phenylenediamine exhibited different morphologies. The superior case is that rodlike composite catalyst was derived from o-phenylenediamine based PDBs. The obtained catalyst exhibited remarkable performances for both cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER), as well as overall water electrolysis. Only 172 and 289 mV of overpotentials and 1.57 V of cell voltage were exhibited at 10 mA cm?2 for HER, OER and water splitting in 1.0 M KOH, respectively. The catalyst also displayed robust stability and high Faraday efficiency, and thus are potential high-performance catalyst for commercial water electrolysis. 相似文献
23.
24.
The slight-alkalization of generator internal cooling water (GICW) is widely used to inhibit the corrosion of hollow copper conductor and thereby ensure the safe operation of the generator. CO2 inleakage is increasingly identified as a potential security risk for GICW system. In this paper, the influence of CO2 inleakage on the slight-alkalization of GICW was theoretically discussed. Based on the equilibriums of the CO2-NaOH-H2O system, CO2 inleakage saturation was derived to quantify the amount of the dissolved CO2 in GICW. This parameter can be directly calculated with the measured conductivity and the [Na+] of GICW. The influence of CO2 inleakage on the slight-alkalization conditioning of GICW and the measurement of its water quality parameters were then analyzed. The more severe the inleakage, the narrower the water quality operation ranges of GICW, resulting in the more difficult the slight-alkalization conditioning of GICW. The temperature calibrations of the conductivity and the pH value of GICW show non-linear correlations with the amount of CO2 inleakage and the NaOH dosage. This study provides insights into the influence of CO2 inleakage on the slight-alkalization of GICW, which can serve as the theoretical basis for the actual slight-alkalization when CO2 inleakage occurs. 相似文献
25.
基于CFD?DEM耦合方法,研究了颗粒在水室内的流动状态,分析了不同刀盘转速、粒子水通入量和水室出口角度对造粒过程的影响,发现提高刀盘转速、增加粒子水通入量和水室出口倾斜一定的角度都有利于水室内颗粒的排出。进一步研究了颗粒与碎屑在水室内的流动,发现在水室出口处二者的流动基本呈现出一定的分离角度。 相似文献
26.
27.
《International Journal of Hydrogen Energy》2022,47(64):27481-27492
Photocatalytic water splitting has become a promising technology to solve environmental pollution and energy shortage. Exploring stable and efficient photocatalysts are highly desired. Herein, we propose novel low-dimensional InSbS3 semiconductors with good stability based on density functional theory. Such InSbS3 structures could be obtained from their bulk crystal by suitable exfoliation methods. Our calculations indicate that two-dimensional (2D) and one-dimensional (1D) InSbS3 nanostructures have moderate band gaps (2.54 and 1.97 eV, respectively) and suitable band edge alignments, which represents sufficient redox capacity for photocatalytic water splitting. 2D InSbS3 monolayer possesses oxygen evolution reaction (OER) activity and 1D InSbS3 single-nanochain possesses hydrogen evolution reaction (HER) activity under acidic conditions. Interestingly, two edge electron states can be introduced when the dimension of InSbS3 is reduced from 2D to 1D and the new electron states can exist in arbitrary-width nanoribbons, which can effectively promote the process of HER. Moreover, InSbS3 monolayer and single-nanochain also exhibit large solar-to-hydrogen efficiency, high carrier mobility, and excellent optical absorption properties, which can facilitate the process of photocatalytic reactions. Our findings can stimulate the synthesis and applications of low-dimensional InSbS3 semiconductors for overall water splitting. 相似文献
28.
29.
Jing-jie Xie Xiao-Li Zou Yan-ping Li Zhuang-Li Kang Han-jun Ma 《International Journal of Food Science & Technology》2022,57(4):2459-2466
The effects of high-pressure-modified soy 11S globulin (0.1, 200, and 400 MPa) on the gel properties, water-holding capacity, and water mobility of pork batter were investigated. The high-pressure-modified soy 11S globulin significantly increased (P < 0.05) the emulsion stability, cooking yield, hardness, springiness, chewiness, resilience, cohesiveness, the a* and b* values, and the G′ and G′′ values of pork batter at 80 °C, compared with those of 0.1 MPa-modified globulin. In contrast, the centrifugal loss and initial relaxation time of T2b, T21, and T22 significantly decreased (P < 0.05). Meanwhile, the microstructure was denser, and the voids were smaller and more uniform compared with those of 0.1 MPa-modified globulin. In addition, the sample with 11S globulin modified at 400 MPa had the best water-holding capacity, gel structure, and gel properties among the samples. Overall, the use of high-pressure-modified soy 11S globulin improved the gel properties and water-holding capacity of pork batter, especially under 400 MPa. 相似文献
30.