全文获取类型
收费全文 | 6459篇 |
免费 | 549篇 |
国内免费 | 304篇 |
专业分类
电工技术 | 420篇 |
综合类 | 356篇 |
化学工业 | 902篇 |
金属工艺 | 407篇 |
机械仪表 | 359篇 |
建筑科学 | 296篇 |
矿业工程 | 155篇 |
能源动力 | 237篇 |
轻工业 | 581篇 |
水利工程 | 104篇 |
石油天然气 | 141篇 |
武器工业 | 83篇 |
无线电 | 448篇 |
一般工业技术 | 645篇 |
冶金工业 | 1322篇 |
原子能技术 | 92篇 |
自动化技术 | 764篇 |
出版年
2024年 | 49篇 |
2023年 | 131篇 |
2022年 | 269篇 |
2021年 | 332篇 |
2020年 | 240篇 |
2019年 | 216篇 |
2018年 | 209篇 |
2017年 | 211篇 |
2016年 | 230篇 |
2015年 | 214篇 |
2014年 | 315篇 |
2013年 | 431篇 |
2012年 | 456篇 |
2011年 | 437篇 |
2010年 | 389篇 |
2009年 | 348篇 |
2008年 | 334篇 |
2007年 | 338篇 |
2006年 | 276篇 |
2005年 | 190篇 |
2004年 | 143篇 |
2003年 | 98篇 |
2002年 | 71篇 |
2001年 | 71篇 |
2000年 | 53篇 |
1999年 | 63篇 |
1998年 | 355篇 |
1997年 | 218篇 |
1996年 | 150篇 |
1995年 | 86篇 |
1994年 | 80篇 |
1993年 | 64篇 |
1992年 | 12篇 |
1991年 | 15篇 |
1990年 | 13篇 |
1989年 | 11篇 |
1988年 | 9篇 |
1987年 | 4篇 |
1986年 | 7篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 49篇 |
1976年 | 86篇 |
1975年 | 3篇 |
排序方式: 共有7312条查询结果,搜索用时 15 毫秒
1.
2.
Anjan Biswas Sonmezoglu Abdullah Ekici Mehmet Alzahrani Abdullah Khamis Belic Milivoj R. 《Journal of Communications Technology and Electronics》2020,65(12):1384-1398
Journal of Communications Technology and Electronics - This paper implements mathematically rigorous extended trial function algorithm to address cubic–quartic optical solitons in... 相似文献
3.
Nur Lina Rashidah Mohd Rashid Abdullah Abdul Samat Abdul Azim Jais Mahendra Rao Somalu Andanastuti Muchtar Nurul Akidah Baharuddin Wan Nor Roslam Wan Isahak 《Ceramics International》2019,45(6):6605-6615
The performance of low-to-intermediate temperature (400–800?°C) solid oxide fuel cells (SOFCs) depends on the properties of electrolyte used. SOFC performance can be enhanced by replacing electrolyte materials from conventional oxide ion (O2-) conductors with proton (H+) conductors because H+ conductors have higher ionic conductivity and theoretical electrical efficiency than O2- conductors within the target temperature range. Electrolytes based on cerate and/or zirconate have been proposed as potential H+ conductors. Cerate-based electrolytes have the highest H+ conductivity, but they are chemically and thermally unstable during redox cycles, whereas zirconate-based electrolytes exhibit the opposite properties. Thus, tailoring the properties of cerate and/or zirconate electrolytes by doping with rare-earth metals has become a main concern for many researchers to further improve the ionic conductivity and stability of electrolytes. This article provides an overview on the properties of four types of cerate and/or zirconate electrolytes including cerate-based, zirconate-based, single-doped cerate–zirconate and hybrid-doped cerate–zirconate. The properties of the proton electrolytes such as ionic conductivity, chemical stability and sinterability are also systematically discussed. This review further provides a summary of the performance of SOFCs operated with cerate and/or zirconate proton conductors and the actual potential of these materials as alternative electrolytes for proton-conducting SOFC application. 相似文献
4.
Guankui Long Yecheng Zhou Mingtao Zhang Randy Sabatini Abdullah Rasmita Li Huang Girish Lakhwani Weibo Gao 《Advanced materials (Deerfield Beach, Fla.)》2019,31(17)
Hybrid organic–inorganic perovskites (HOIPs), in particular 3D HOIPs, have demonstrated remarkable properties, including ultralong charge‐carrier diffusion lengths, high dielectric constants, low trap densities, tunable absorption and emission wavelengths, strong spin–orbit coupling, and large Rashba splitting. These superior properties have generated intensive research interest in HOIPs for high‐performance optoelectronics and spintronics. Here, 3D hybrid organic–inorganic perovskites that implant chirality through introducing the chiral methylammonium cation are demonstrated. Based on structural optimization, phonon spectra, formation energy, and ab initio molecular dynamics simulations, it is found that the chirality of the chiral cations can be successfully transferred to the framework of 3D HOIPs, and the resulting 3D chiral HOIPs are both kinetically and thermodynamically stable. Combining chirality with the impressive optical, electrical, and spintronic properties of 3D perovskites, 3D chiral perovskites is of great interest in the fields of piezoelectricity, pyroelectricity, ferroelectricity, topological quantum engineering, circularly polarized optoelectronics, and spintronics. 相似文献
5.
图形点阵式液晶显示器MSP-G320240在高速处理器DSP中的应用 总被引:1,自引:1,他引:0
介绍了内置SD1335控制器的图形液晶显示器MSP-G320240的工作原理及应用方法,给出了MSP-G320240液晶显示器同DSP的简单接口电路,同时给出了相应的液晶显示器的初始化和清显示区的具体程序。 相似文献
6.
7.
8.
9.
10.
Comparison evaluation of the methods of treatment was based on the analysis of the results of management of 347 patients with general purulent decompensated peritonitis with polyorganic insufficiency. The efficacy of closed drainage in 98 patients, continuous flow irrigation (dialysis) in 126, stage programmed irrigation and inspection of the abdominal cavity in 99, and open drainage in 24 patients was compared. The causes of peritonitis were: complications after acute surgical diseases (in 156 cases), in planned operations (59), and in obstetrical and gynecological diseases (132). Most of the patients were brought to the clinic from other hospitals because of unsuccessful treatment of peritonitis and absence of means for performing hemodialysis and management of polyorganic insufficiency. The incidence of the last-named reached 71.0 to 91.0% in the different groups of patients. In monotypic complex treatment, stage programmed irrigation was marked by a much lesser number of abscesses and other complications and a lower mortality (20.2%) as compared to flow irrigation (30.0%, closed drainage (27.5%), and open (laparostomy) treatment (37.5%). Despite the very serious contingent of patients, total mortality (27.0%) in the application of the indicated methods was quite low. 相似文献