全文获取类型
收费全文 | 410篇 |
免费 | 11篇 |
专业分类
电工技术 | 45篇 |
化学工业 | 91篇 |
金属工艺 | 10篇 |
机械仪表 | 1篇 |
建筑科学 | 6篇 |
能源动力 | 37篇 |
轻工业 | 34篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 34篇 |
一般工业技术 | 66篇 |
冶金工业 | 34篇 |
原子能技术 | 11篇 |
自动化技术 | 50篇 |
出版年
2023年 | 8篇 |
2022年 | 11篇 |
2021年 | 11篇 |
2020年 | 7篇 |
2019年 | 6篇 |
2018年 | 9篇 |
2017年 | 4篇 |
2016年 | 6篇 |
2015年 | 11篇 |
2014年 | 12篇 |
2013年 | 25篇 |
2012年 | 20篇 |
2011年 | 33篇 |
2010年 | 20篇 |
2009年 | 33篇 |
2008年 | 15篇 |
2007年 | 18篇 |
2006年 | 18篇 |
2005年 | 15篇 |
2004年 | 12篇 |
2003年 | 26篇 |
2002年 | 6篇 |
2001年 | 13篇 |
2000年 | 3篇 |
1999年 | 8篇 |
1998年 | 4篇 |
1997年 | 6篇 |
1996年 | 8篇 |
1995年 | 7篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1992年 | 9篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1988年 | 1篇 |
1986年 | 2篇 |
1985年 | 8篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1974年 | 2篇 |
1967年 | 1篇 |
排序方式: 共有421条查询结果,搜索用时 15 毫秒
31.
Seonwoo Kim Kuniko Suzuki Ai Sugie Hiroyuki Yoshida Masafumi Yoshida 《Science and Technology of Advanced Materials》2018,19(1):486-494
Charge trap in amorphous perfluoro-polymer electret is studied, focusing on electron trap site and trap energy. Low-energy inverse photoelectron spectroscopy is adopted to measure solid-state electron affinity (EA) of cyclic transparent optical polymer (CYTOP). EA of CYTOP CTL-S is discovered by compensating the unwanted charge-up effect. Negatively-charged electret materials (polyethylene, ethylene-tetra-fluoro-ethylene, poly-tetra-fluoro-ethylene, and CYTOP) are analyzed by quantum mechanical calculation. Density functional theory with long-range correction is adopted to analyze orbital energies of single molecular systems. Intramolecular distribution of trapped electron and EA are investigated. Calculated electron affinities of CYTOP polymers with different end group are qualitatively in accordance with trapped charge stability measured with thermal stimulated discharge, signifying that electron affinities obtained with the present simulation can be used as an index of amorphous polymer electret. 相似文献
32.
33.
Satoru Hiroshige Hirotoshi Asano Masafumi Uchida Hideto Ide 《Artificial Life and Robotics》2009,14(1):67-70
Recently, there has been much interest in the study of the formation of groups of agents that cause interactions between agents and invent new functions. We gave some agents an action rule based on the interactions of human feelings by using a circumplex model. It had been decided that the parameters of feelings in this model should have only two axes. In this report, eight basic action dimensions and pure feelings on four corresponding axes were given to agents as a model of feelings and actions based on the multiple factor analysis theory of R. Plutchik, and the behavioral characteristics of the group of agents were examined. 相似文献
34.
Hiroshi Kanbe Mami Hirose Tatsuya Ito Masafumi Taniwaki 《Journal of Electronic Materials》2010,39(8):1248-1255
Ge/Si heterojunctions formed by wet wafer bonding were observed using transmission electron microscopy and energy-dispersive
x-ray spectroscopy. For the samples annealed at 880°C, there was a transition layer at the heterointerface with modified regions
in the Si and Ge extending 20 nm to 30 nm from the interface. In these modified regions, crystal defects were observed, and
a large amount of Ge was detected on the Si side of the junction. For the samples annealed at 250°C or 350°C, the transition
layers had an amorphous-like structure with a thickness of about 10 nm. No modified layer or enlargement of lattice spacing
was observed. 相似文献
35.
Phase relations for the Al2O3-CaF2-SiO2 system were investigated from 1673 to 1723 K. The hotfilament technique was applied to observe a two-liquid region and liquidus
for the ternary system. The liquidus saturated with SiO2 was investigated at 1673 K by using the hot-filament technique and the chemical equilibrium technique. In this system, the
addition of Al2O3 to the CaF2-SiO2 system reduces the congruent temperature. A small substitution of Al2O3 for CaF2 increases the solubility of SiO2, namely, if the region of liquid phase could be enlarged. These results suggest that Al2O3 would be an effective substitute of CaF2 in slag for steelmaking. 相似文献
36.
Yoshihiko Nakata Satoshi Ninomiya Chikage Imada Masafumi Nagai Takaaki Aoki Jiro Matsuo Nobutsugu Imanishi 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2005,230(1-4):489-494
We have measured both secondary neutral and ionized particles from an InSb target under 3.0 MeV Si ion bombardment. Measurements of both ions and neutrals have not been carried out so far in the MeV-energy range. The mass spectra and axial emission energy distributions of secondary particles were investigated. Secondary ions were measured with a linear- and a reflective-type time-of-flight technique, whereas secondary neutral particles were photo-ionized by a UV pulsed laser (ArF: 193 nm) and measured with a reflective-type time-of-flight technique. Different results were obtained for neutral particles in comparison with ionized particles. The mean energy of neutral Sb atoms was much lower than that of neutral In atoms, whereas the mean energies of secondary In and Sb ions were nearly equal. 相似文献
37.
MATSUDA Hisashi CHIBA Takahiro YAGAMI Masaki TAJIMA Yusuke WATANABE Nobuyoshi SATO Hideaki TAKEYAMA Masafumi 《热科学学报(英文版)》2022,31(1):72-81
The plasma actuation (PA) effect on the snow falling flow was investigated using a plasma electrode with weather resistant design and the natural snow wind facility of the Hokkaido University of Science. NACA0015 test blade with chord length c of 300 mm was used. Wind tunnel tests were carried out under the angle of the attack of the blade was fixed at 15 degrees, and the main flow velocity is U=5 m/s. PIV (Particle image velocimetry) measurements were conducted on various PA conditions using natural dry snowflakes as a tracer. When the actuator was driven under the condition of the fundamental frequency of F=50 kHz, and the pulsed modulated frequency f of fc/U=1 and Duty ratio (Ratio of plasma ON time to pulse duration time) =1%, movement of snowflakes was controlled the most effectively tested. It was clarified that the fundamental frequency of PA also affects the control of snow flow. Under snowfall conditions, the weather resistant designed plasma electrode has suffered no damage and operated successfully. 相似文献
38.
Tomohiro Itoh Kenji Ohguchi Chizuru Nakajima Masayoshi Oyama Munekazu Iinuma Yoshinori Nozawa Yukihiro Akao Masafumi Ito 《Food chemistry》2011
We found that two distinct flavonoid glycosides isolated from the peel of Japanese persimmon (Diospyros kaki Fuyu), isoquercitrin (Isq) and hyperin (Hyp), are capable of inhibiting antigen-stimulated degranulation in rat basophilic leukaemia RBL-2H3 cells. In order to elucidate the underlying mechanisms, we examined effects of Isq and Hyp on cellular responses induced by antigen stimulation. Treatment with both Isq and Hyp markedly inhibited antigen-stimulated elevation of intracellular free Ca2+ concentration and reactive oxygen species (ROS). Isq and Hyp did not affect NADPH oxidase (NOX) activity, but they possessed DPPH radical-scavenging activity similar to that of epigallocatechin gallate, a potent anti-oxidant, Finally, Isq and Hyp showed little or no effects on Ag-stimulated Syk activation or phosphorylation of signalling molecules. These results indicate that inhibition of antigen-stimulated degranulation by Isq and Hyp is mainly due to suppression of intracellular Ca2+ elevation, which is caused by direct scavenging of ROS that are generated by NOX. Our findings suggest that Isq and Hyp, isolated from the peel of persimmon, would be beneficial for alleviating symptoms of type I allergy. 相似文献
39.
Kan‐Hua Lee Kenji Araki Li Wang Nobuaki Kojima Yoshio Ohshita Masafumi Yamaguchi 《Progress in Photovoltaics: Research and Applications》2016,24(10):1310-1318
The paper presents a quantitative approach to the investigation and comparison of the material qualities of III–V on silicon (III–V/Si) solar cells by using external radiative efficiencies. We use this analysis to predict the limiting efficiencies and evaluate the criteria of material quality in order to achieve high‐efficiency III–V/Si solar cells. This result yields several implications for the design of high‐efficiency III–V/Si solar cells. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
40.
Operation of a two-stage fermentation process producing hydrogen and methane from organic waste 总被引:7,自引:0,他引:7
A pilot-scale experimental plant for the production of hydrogen and methane by a two-stage fermentation process was constructed and operated using a mixture of pulverized garbage and shredded paper wastes. Thermophilic hydrogen fermentation was established at 60 degrees C in the first bioreactor by inoculating with seed microflora. Following the hydrogenogenic process, methanogenesis in the second bioreactor was conducted at 55 degrees C using an internal recirculation packed-bed reactor (IRPR). After conducting steady-state operations under a few selected conditions, the overall hydraulic retention time was optimized at 8 d (hydrogenogenesis, 1.2 d; methanogenesis, 6.8 d), producing 5.4 m3/m3/d of hydrogen and 6.1 m3/m3/d of methane with chemical oxygen demand and volatile suspended solid removal efficiencies of 79.3% and 87.8%, respectively. Maximum hydrogen production yield was calculated to be 2.4 mol/mol hexose and 56 L/kg COD loaded. The methanogenic performance of the IRPR was stable, although the organic loading rate and the composition of the effluent from the hydrogenogenic process fluctuated substantially. A clone library analysis of the microflora in the hydrogenogenic reactor indicated that hydrogen-producing Thermoanaerobacterium-related organisms in the inoculum were active in the hydrogen fermentation of garbage and paper wastes, although no aseptic operations were applied. We speculate that the operation at high temperature and the inoculation of thermophiles enabled the selective growth of the introduced microorganisms and gave hydrogen fermentation efficiencies comparable to laboratory experiments. This is the first report on fermentative production of hydrogen and methane from organic waste at an actual level. 相似文献