全文获取类型
收费全文 | 652篇 |
免费 | 20篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 26篇 |
综合类 | 3篇 |
化学工业 | 131篇 |
金属工艺 | 11篇 |
机械仪表 | 9篇 |
建筑科学 | 14篇 |
能源动力 | 28篇 |
轻工业 | 44篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 93篇 |
一般工业技术 | 106篇 |
冶金工业 | 138篇 |
原子能技术 | 7篇 |
自动化技术 | 62篇 |
出版年
2023年 | 4篇 |
2022年 | 12篇 |
2021年 | 11篇 |
2020年 | 9篇 |
2019年 | 7篇 |
2018年 | 13篇 |
2017年 | 8篇 |
2016年 | 10篇 |
2015年 | 10篇 |
2014年 | 11篇 |
2013年 | 23篇 |
2012年 | 21篇 |
2011年 | 29篇 |
2010年 | 24篇 |
2009年 | 38篇 |
2008年 | 36篇 |
2007年 | 23篇 |
2006年 | 15篇 |
2005年 | 14篇 |
2004年 | 19篇 |
2003年 | 14篇 |
2002年 | 19篇 |
2001年 | 13篇 |
2000年 | 8篇 |
1999年 | 20篇 |
1998年 | 68篇 |
1997年 | 47篇 |
1996年 | 25篇 |
1995年 | 13篇 |
1994年 | 17篇 |
1993年 | 15篇 |
1992年 | 4篇 |
1991年 | 13篇 |
1990年 | 9篇 |
1989年 | 7篇 |
1988年 | 10篇 |
1987年 | 1篇 |
1986年 | 5篇 |
1985年 | 7篇 |
1984年 | 1篇 |
1983年 | 5篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1974年 | 1篇 |
排序方式: 共有674条查询结果,搜索用时 15 毫秒
61.
N. K. Sheridon E. A. Richley J. C. Mikkelsen D. Tsuda J. M. Crowley K. A. Oraha M. E. Howard M. A. Rodkin R. Swidler R. Sprague 《Journal of the Society for Information Display》1999,7(2):141-144
Abstract— The Gyricon display consists of hemispherical black and white (bichromal) balls contained in individual liquid-filled cavities and disposed to orient in an electrical field. This bistable reflective light display currently has a diffuse reflectance of more than 18% and a contrast ratio of more than 6:1. The viewing angle approaches that of paper. A new method of fabricating the bichromal balls has enabled practical realization of large-area high-quality displays. 相似文献
62.
63.
K Kajiwara E Sugaya N Yuyama H Nagasawa T Tsuda A Sugaya M Motoki K Shimizu-Nishikawa M Kimura 《Canadian Metallurgical Quarterly》1997,47(1-2):49-58
To determine the molecular mechanism of regulation of pentylenetetrazol (PTZ)-induced calcium entry by the seizure-related gene, PTZ-17, the role of the 3'-untranslated region (3'UTR) and also interaction between 3'UTR and intracellular factors were investigated. PTZ-induced calcium inward current in Xenopus oocytes injected with PTZ-17 RNA varied in magnitude among strains of mice: RNA derived from the DBA/2 mouse, which has a high susceptibility to convulsions, showed the largest current and that from the BALB/c mouse with a low susceptibility to convulsions showed no PTZ response. The sequence of 3'UTR showed alterations among mouse strains: 3'UTR of BALB/c showed a sequence alteration from T to G and that of DBA/2 showed a GTG insertion compared with that of B6. The 3'UTR also regulated the translation of chloramphenicol acetyltransferase (CAT) RNA depending on its sequence. A particular region within the 3'UTR demonstrated interaction with 60- and 47-kDa proteins. Sequence alterations in this region corresponded to disappearance or increase in PTZ-induced calcium entry. These findings suggest that a particular region within 3'UTR of the seizure-related gene, PTZ-17, is involved in PTZ-induced calcium entry via interaction between mRNA and specific RNA-binding proteins. 相似文献
64.
A novel cytokine termed osteoclastogenesis inhibitory factor (OCIF) was purified to homogeneity from conditioned medium of human embryonic lung fibroblasts. OCIF is a heparin-binding basic glycoprotein with Mr of 60 kDa for a monomer and 120 kDa for a homodimer. OCIF specifically inhibits osteoclastogenesis in vitro and increases bone mineral density and bone volume in normal rats. The cloning of OCIF cDNA revealed that OCIF is a soluble member of the tumor necrosis factor receptor (TNFR) superfamily consisting of four cystein-rich domains, two death domain homologous regions (DDHs), and C-terminal basic domain. Mutational analysis of OCIF revealed that N-terminal portion of OCIF consisting of four cystein-rich domains is sufficient to inhibit osteoclastogenesis. OCIF inhibits osteoclastogenesis by binding to the sites expressed on osteoblastic cells and interrupting cell-to-cell signaling between osteoblastic cells and osteoclast progenitors. 相似文献
65.
H. Tsuda K. Hirabayashi Y. Tohmori T. Kurokawa 《Photonics Technology Letters, IEEE》1991,3(6):504-506
A tunable light source with a liquid-crystal Fabry-Perot interferometer (LC-FPI) tuning element that emits a laser beam with a tuning range of 41 nm has been constructed. Incorporating a multiple quantum well (MQW) laser diode with a phase control (PC) section enables the selection of almost all external modes. Stable single-mode emission is obtained for the region, except where the slope of the lasing wavelength versus applied voltage to the liquid crystal is quite large.<> 相似文献
66.
We report a rare case with rupture of thymic cyst including mediastinal hemorrhage and hemothorax. A 68-year-old man was referred to our hospital for the treatment of right hemothorax. A chest roentgenogram following thoracentesis demonstrated a widened mediastinum. Chest computed tomograms revealed a large anterior mediastinal mass extending to the right pleural cavity and bilateral pleural effusion. Digital subtraction angiography showed a normal aorta and great vessels. A median stenotomy revealed a large encysted hematoma along the thymic cyst extending from the right anterior mediastinum into the right pleural cavity and ending with rupture. Pathological examination demonstrated that the largest thymic cyst was continued to the hematoma resulting from partial destruction of its epithelial lining. To our knowledge, only five cases including our's with ruptured thymic tumors were reported, and this is the first report of ruptured thymic cyst resulting in mediastinal hemorrhage and hemothorax. 相似文献
67.
Yasutaka Nagai Takashi Yamamoto Tsunehiro Tanaka Satohiro Yoshida Takamasa Nonaka Tokuhiko Okamoto Akihiko Suda Masahiro Sugiura 《Catalysis Today》2002,74(3-4):225-234
Three types of CeO2–ZrO2 (Ce:Zr=1:1 molar ratio) compounds with different oxygen storage/release capacities (OSCs) were characterized by means of the Ce K-edge and Zr K-edge X-ray absorption fine structure (XAFS). In order to investigate the relationship between the OSC and local structure, the quantitative EXAFS curve-fitting analysis was applied. By enhancing the homogeneity of the Ce and Zr atoms in the CeO2–ZrO2 solid solution, the OSC performance increased. Especially, the atomically homogeneous Ce0.5Zr0.5O2 solid solution exhibited the highest OSC among these CeO2–ZrO2 samples. Additionally, the local oxygen environment around Ce and Zr was remarkably modified by enhancing the homogeneity of the CeO2–ZrO2 solid solution. It was postulated that the enhancement of the homogeneity of the CeO2–ZrO2 solid solution and the modification of the oxygen environment would be the source for the OSC improvement. 相似文献
68.
An investigation of how the stimulated Brillouin scattering threshold of dispersion compensating fibres is affected by Raman amplification is presented. Experimental data is in good agreement with the threshold values predicted by the theoretical approach 相似文献
69.
To clarify the feasibility of introducing solar total energy system into various factories, an experimental facility was constructed at Tsukuba Second Research Center on March 1982. Long-term experimental studies are presently being continued to determine the operating characteristic of the facility. This facility is constructed to improve the system availability and to collect effectively solar energy under fairly bad weather conditions as experienced in Japan. To accomplish this purpose, it is operated by selecting one of three operating modes according to the intensity of insolation and the thermal condition of the heat storage unit. In this paper, the outline of the facility is described. Experimental results show that in this facility the operating rate increases and useful energy, such as electricity, can be obtained from solar energy if the operating mode is selected according to the weather condition at 8:00 a.m. 相似文献
70.
Seiichi Kiyama Shingo Nakano Yoichi Domoto Hitoshi Hirano Hisaki Tarui Kenichiro Wakisaka Makoto Tanaka Shinya Tsuda Shoichi Nakano 《Solar Energy Materials & Solar Cells》1997,48(1-4)
This paper proposes a new advanced fabrication technology for a low-cost integrated-type a-Si solar cell. Integrated-type cells provide many advantages and have been industrialized with a laser patterning method. However, a higher throughput and more efficient patterning method was required for applying a-Si solar cells to a power generating system. Plasma CVM (Chemical Vaporization Machining) was first applied to advanced patterning because of its advantages of high speed and selectivity. In this method, a plasma generated under high pressure localizes near the wire electrode and concentrates reactive radicals. As a result, we achieved an etching rate of more than 1 μm/s and selective patterning of a 200 μm-wide a-Si layer in 1 s multiline patterning was also developed for large-area modules. 相似文献