全文获取类型
收费全文 | 481篇 |
免费 | 21篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 43篇 |
综合类 | 4篇 |
化学工业 | 139篇 |
金属工艺 | 6篇 |
机械仪表 | 9篇 |
建筑科学 | 3篇 |
能源动力 | 25篇 |
轻工业 | 40篇 |
水利工程 | 1篇 |
石油天然气 | 2篇 |
无线电 | 33篇 |
一般工业技术 | 125篇 |
冶金工业 | 11篇 |
原子能技术 | 11篇 |
自动化技术 | 52篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 13篇 |
2020年 | 3篇 |
2019年 | 9篇 |
2018年 | 5篇 |
2017年 | 11篇 |
2016年 | 12篇 |
2015年 | 10篇 |
2014年 | 22篇 |
2013年 | 32篇 |
2012年 | 26篇 |
2011年 | 32篇 |
2010年 | 26篇 |
2009年 | 29篇 |
2008年 | 37篇 |
2007年 | 25篇 |
2006年 | 34篇 |
2005年 | 33篇 |
2004年 | 17篇 |
2003年 | 12篇 |
2002年 | 20篇 |
2001年 | 8篇 |
2000年 | 6篇 |
1999年 | 8篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有504条查询结果,搜索用时 31 毫秒
311.
312.
Hironobu Makitsubo Takehiko Wada Hirokazu Kataza Makoto Mita Toyoaki Suzuki Keita Yamamoto 《Journal of Infrared, Millimeter and Terahertz Waves》2017,38(2):206-214
We propose an all-silicon multi-layer interference filter composed solely of silicon with sub-wavelength structure (SWS) in order to realize high performance optical filters operating in the THz frequency region with robustness against cryogenic thermal cycling and mechanical damage. We demonstrate fabrication of a three-layer prototype using well-established common micro-electro-mechanical systems (MEMS) technologies as a first step toward developing practical filters. The measured transmittance of the three-layer filter agrees well with the theoretical transmittances calculated by a simple thin-film calculation with effective refractive indices as well as a rigorous coupled-wave analysis simulation. We experimentally show that SWS layers can work as homogeneous thin-film interference layers with effective refractive indices even if there are multiple SWS layers in a filter. 相似文献
313.
314.
315.
Akiyama H Ito A Sato M Kawabe Y Kamihira M 《International journal of molecular sciences》2010,11(8):2910-2920
Here we applied a magnetic force-based tissue engineering technique to cardiac tissue fabrication. A mixture of extracellular matrix precursor and cardiomyocytes labeled with magnetic nanoparticles was added into a well containing a central polycarbonate cylinder. With the use of a magnet, the cells were attracted to the bottom of the well and allowed to form a cell layer. During cultivation, the cell layer shrank towards the cylinder, leading to the formation of a ring-shaped tissue that possessed a multilayered cell structure and contractile properties. These results indicate that magnetic tissue fabrication is a promising approach for cardiac tissue engineering. 相似文献
316.
Hirokazu Masai Takahiro Ueno Yoshihiro Takahashi Takumi Fujiwara 《Optical Materials》2011,33(12):1980-1983
Crystallization behavior of the oxide semiconductor ZnO in zinc borate glass was investigated. The precipitated crystalline phase of glass ceramics containing a small amount of Al2O3 was α-Zn3B2O6 whereas that of the glass ceramics containing a large amount of Al2O3 was ZnO. It was found that the c-oriented precipitation of ZnO in a glass ceramic was brought about by the in-plane crystal growth of needle-like ZnO crystallites along the a-axis. Amount of Al2O3 that can make glass network affected the coordination state of B2O3 in the glass, and a three-coordinated BO3 unit was preferentially formed in the glass containing a higher amount of Al2O3. The present results suggest that crystallization of ZnO from multi-component glass is dominated by the local coordination state of the mother glass. 相似文献
317.
Zschieschang U Yamamoto T Takimiya K Kuwabara H Ikeda M Sekitani T Someya T Klauk H 《Advanced materials (Deerfield Beach, Fla.)》2011,23(5):654-658
Organic transistors and circuits are fabricated directly on the surface of banknotes. The transistors operate with voltages of 3 V and have a field-effect mobility of about 0.2 cm2 V?1s?1. For an array of 100 transistors a yield of 92% is obtained. 相似文献
318.
Hirokazu Kitaura 《Electrochimica acta》2010,55(28):8821-8828
LiNi1/3Co1/3Mn1/3O2 was applied as a promising material to the all-solid-state lithium cells using the 80Li2S·19P2S5·1P2O5 (mol%) solid electrolyte. The cell showed the first discharge capacity of 115 mAh g−1 at the current density of 0.064 mA cm−2 and retained the reversible capacity of 110 mAh g−1 after 10 cycles. The interfacial resistance was observed in the impedance spectrum of the all-solid-state cell charged to 4.4 V (vs. Li) and the transition metal elements were detected on the solid electrolyte in the vicinity of LiNi1/3Co1/3Mn1/3O2 by the TEM observations with EDX analyses. The electrochemical performance was improved by the coating of LiNi1/3Co1/3Mn1/3O2 particles with Li4Ti5O12 film. The interfacial resistance was decreased and the discharge capacity was increased from 63 to 83 mAh g−1 at 1.3 mA cm−2 by the coating. The electrochemical performance of LiNi1/3Co1/3Mn1/3O2 was compared with that of LiCoO2, LiMn2O4 and LiNiO2 in the all-solid-state cells. The rate capability of LiNi1/3Co1/3Mn1/3O2 was lower than that of LiCoO2. However, the reversible capacity of LiNi1/3Co1/3Mn1/3O2 at 0.064 mA cm−2 was larger than that of LiCoO2, LiMn2O4 and LiNiO2. 相似文献
319.
Satoshi Yamamoto Osamu Nukaga Hiroyuki Wakioka Tatsuo Suemasu Hirokazu Hashimoto 《Electrical Engineering in Japan》2012,179(1):54-62
Crank‐shaped and Y‐shaped through‐hole interconnections (THI) filled with Au‐Sn solder are demonstrated in this study. They are expected to realize a higher‐density wafer‐level package (WLP) for electrical devices including the fields of MEMS (Micro Electro‐Mechanical Systems) and MOEMS (Micro Optical Electro‐Mechanical Systems) compared with conventional WLP using THI consisting of straight through‐holes. In this paper, formation techniques for crank‐shaped and Y‐shaped THI are described. In order to make crank‐shaped and Y‐shaped through‐holes in a substrate, both femtosecond laser irradiation and wet chemical etching are used. Crank‐shaped through‐holes with an 80‐μm opening and 400 μm deep have also been achieved. Gold (Au)‐tin (Sn) solder was filled into the holes using the molten metal suction method (MMSM). Airtightness of the THI was examined using the helium leakage test, and the estimated leakage rate was less than 1.0 × 10?9 Pa·m3/s, which is sufficient for use in WLP applications. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 179(1): 54–62, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com) . DOI 10.1002/eej.21134 相似文献
320.
Taniguchi M Kato K Matsui O Ping X Nakayama H Usuki Y Ichimura A Fujita K Tanaka T Tarui Y Hirasawa E 《Journal of Bioscience and Bioengineering》2005,100(2):207-211
Cross-linked poly-gamma-glutamic acid (C-L gamma-PGA) at 5 microg/ml flocculated bentonite suspension pretreated with polyaluminum chloride (PAC) at 2 microg/ml Al3+-PAC to a transparency of approximately 30% after 30 min and more than 90% after 4 h, while Al3+ concentration in the upper phase of the suspension decreased with incubation time. When pretreated with FeCl3 at 16 microg/ml Fe3+-FeCl3, similar results were obtained. In the case of Escherichia coli suspension, the combination of C-L gamma-PGA and FeCl3 demonstrated a more marked flocculating activity with a satisfactory transparency occurring after 30 min of treatment, accompanied by a decrease in residual Fe3+ concentration. In the above two suspensions pretreated with FeCl3, small visible floats appeared in the early stage of incubation. These floats were found to be due to the direct interaction between FeCl3 and C-L gamma-PGA, indicating the formation of a water-insoluble complex. After allowing the suspension to stand for a long time, elemental analysis and inductively coupled plasma spectroscopy of the precipitates produced suggested that not only the complex was formed due to the interaction between Fe3+ in FeCl3 and COO- in the C-L gamma-PGA molecule, but also Fe2O3 and Fe(OH)3 might be entrapped in this complex. This could be applied to scavenge metal ions including Fe3+ from polluted water. 相似文献