全文获取类型
收费全文 | 1575篇 |
免费 | 20篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 103篇 |
化学工业 | 430篇 |
金属工艺 | 27篇 |
机械仪表 | 31篇 |
建筑科学 | 33篇 |
矿业工程 | 1篇 |
能源动力 | 60篇 |
轻工业 | 118篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 115篇 |
一般工业技术 | 326篇 |
冶金工业 | 98篇 |
原子能技术 | 52篇 |
自动化技术 | 203篇 |
出版年
2022年 | 25篇 |
2021年 | 23篇 |
2020年 | 8篇 |
2019年 | 13篇 |
2018年 | 11篇 |
2017年 | 18篇 |
2016年 | 29篇 |
2015年 | 15篇 |
2014年 | 39篇 |
2013年 | 75篇 |
2012年 | 58篇 |
2011年 | 89篇 |
2010年 | 62篇 |
2009年 | 57篇 |
2008年 | 81篇 |
2007年 | 78篇 |
2006年 | 67篇 |
2005年 | 57篇 |
2004年 | 53篇 |
2003年 | 57篇 |
2002年 | 56篇 |
2001年 | 44篇 |
2000年 | 31篇 |
1999年 | 34篇 |
1998年 | 70篇 |
1997年 | 45篇 |
1996年 | 34篇 |
1995年 | 29篇 |
1994年 | 24篇 |
1993年 | 33篇 |
1992年 | 22篇 |
1991年 | 22篇 |
1990年 | 19篇 |
1989年 | 16篇 |
1988年 | 22篇 |
1987年 | 13篇 |
1986年 | 18篇 |
1985年 | 19篇 |
1984年 | 20篇 |
1983年 | 9篇 |
1982年 | 10篇 |
1981年 | 12篇 |
1980年 | 11篇 |
1979年 | 17篇 |
1978年 | 12篇 |
1977年 | 4篇 |
1976年 | 12篇 |
1974年 | 5篇 |
1973年 | 8篇 |
1970年 | 4篇 |
排序方式: 共有1599条查询结果,搜索用时 15 毫秒
991.
Endo T Hisamichi Y Kimura O Haraguchi K Baker CS 《The Science of the total environment》2008,401(1-3):73-80
Total mercury (T-Hg), methyl mercury (M-Hg), cadmium (Cd), selenium (Se), zinc (Zn) and copper (Cu) concentrations in the organs of melon-headed whales from a mass stranding on the Japanese coast were analyzed. The mean concentration of T-Hg in the liver (126+/-97 microg/wet g, n=13) was markedly higher than those in kidney (6.34+/-2.36 microg/wet g, n=12) and muscle (4.90+/-2.33 microg/wet g, n=15). In contrast, the mean concentration of M-Hg in the liver (9.08+/-2.24 microg/wet g) was similar to those in the kidney (3.47+/-0.91 microg/wet g) and muscle (3.78+/-1.53 microg/wet g). The mean percentage of M-Hg in the T-Hg found in the liver (13.1+/-10.3) was significantly lower than those in the kidney (58.3+/-15.0) and muscle (78.9+/-8.4). The molar ratio of T-Hg to Se in the liver was effectively 1.0, but those in the kidney and muscle were markedly lower. Conversely, the mean concentration of Cd was markedly higher in the kidney (24.4+/-7.4 microg/wet g) than in the liver (7.24+/-2.08 microg/wet g) and muscle (less than 0.05 microg/wet g). These results suggest that the formation of Hg-Se compounds mainly occurs in the liver after the demethylation of M-Hg, and Cd preferentially accumulates in the kidney of melon-headed whales. 相似文献
992.
Osamu Ohtaka Shoichi Kume Tsutomu Iwami Kazunori Urabe 《Journal of the American Ceramic Society》1988,71(3):164-C
A mixture of tetragonal and monoclinic 2Y˙ZrO2 (2 mol% Y2 O3 –ZrO2 ) powder was treated from 400° to 800°C and from 4 to 7 GPa for 30 min. The products were identified by powder XRD, Raman spectroscopy, and TEM. Results indicated that an orthorhombic phase was synthesized at T=400° to 600°C and P>4 GPa. The lattice parameters were obtained as a=0.505, b=0.525, and c=0.509 nm; the density was 6.17 Mg/m3 . The orthorhombic phase always coexisted with the tetragonal phase in the products. The amounts of the tetragonal phase before and after treatment remained largely unchanged, whereas the amount of new orthorhombic phase was nearly the same as the decreased amount of the monoclinic phase. It was assumed, therefore, that only the monoclinic phase transformed into the orthorhombic phase. 相似文献
993.
Katsumi Kushiya Muneyori Tachiyuki Yoshinori Nagoya Atsushi Fujimaki Baosheng Sang Daisuke Okumura Masao Satoh Osamu Yamase 《Solar Energy Materials & Solar Cells》2001,67(1-4)
Applying basically the same innovative and robust fabrication technologies which, for the first time, led to the achievement of remarkably high efficiency of 14.2% at an aperture area of 51.7 cm2 with a Zn(O,S,OH)x buffer layer, the following goals have been targeted: (1) 13% efficiency on a 30 cm×30 cm module and (2) establishment of the fabrication technologies to attain 140 yen/Wp in the annual production capacity of 100 MWp/a. The main focus is currently on the technology development (1) to increase the Voc related to the CIGS absorber and (2) to improve the Jsc related to the DC-sputtered ZnO window layer with a multilayered structure. This contribution well explains the status and strategy of Showa Shell Sekiyu K.K. on the R&D of CIGS-based thin-film modules to achieve the above two goals by the end of FY2000. 相似文献
994.
Mark G. Beckett Paul Coddington Bálint Joó Chris M. Maynard Dirk Pleiter Osamu Tatebe Tomoteru Yoshie 《Computer Physics Communications》2011,(6):1208-1214
We present the International Lattice Data Grid (ILDG), a loosely federated grid-of-grids for sharing data from Lattice Quantum Chromodynamics (LQCD) simulations. The ILDG comprises of metadata, file-format and web-service standards, which can be used to wrap regional data-grid interfaces, allowing seamless access to catalogues and data in a diverse set of collaborating regional grids. We discuss the technological underpinnings of the ILDG, primarily the metadata and the middleware, and offer a critique of its various aspects with the hindsight of the design work and the two years of production. 相似文献
995.
996.
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
997.
Teams and teamwork are indispensable, especially when tackling difficult and complex tasks that cannot be easily addressed
by a single individual. Because breakdowns in team cooperation can cause accidents, much research attention has been devoted
to studies on team cooperation and many teamwork models and theories have been proposed. These models and theories are concerned
with observable team behaviors like closed-loop communication, backup-behaviors, and a few traits demonstrating good leadership;
however, they do not provide a clear explanation for the mechanism behind them. To better understand team cooperation, it
is believed to be additionally necessary to clarify the cognitive factors behind team behaviors. This study aims to examine
the factors of cognition underlying cooperation and to propose a team cognition model that can describe and explain these
factors in team cooperation. As a method to examine the underlying cognitive factors for cooperation, we analyzed participants’
reflection on cooperation and elicited several important factors for cooperation. Then, based on these factors and the findings
of both previous studies by team researchers and human cognitive abilities, a team cognition model that can capture a part
of the cognitive factors for team cooperation was developed. Suggestive evidence for the importance of metacognition on cooperation
was also provided. 相似文献
998.
Makoto Tanaka Kazumi Kashiwagi Naoki Kawashima Satoshi Kitaoka Osamu Sakurada Yutaka Ohya 《Corrosion Science》2012
The effect of grain boundary cracks on the corrosion behaviour of non-doped aluminium titanate (AT) ceramics was evaluated in a molten Al alloy containing a slight amount of Mg. The corrosion of AT ceramics, in which the AT grains decomposed and subsequently reacted with liquid and/or gaseous Mg to produce MgAl2O4, proceeded not only on sample surfaces in contact and non-contact with the melt, but also on open grain boundary crack surfaces in the ceramic interior. Therefore, the corrosion resistance of AT ceramics can be improved by control of their grain size to close open cracks in the molten alloys. 相似文献
999.
1000.