全文获取类型
收费全文 | 306篇 |
免费 | 21篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 19篇 |
综合类 | 1篇 |
化学工业 | 86篇 |
金属工艺 | 22篇 |
机械仪表 | 3篇 |
建筑科学 | 3篇 |
能源动力 | 10篇 |
轻工业 | 17篇 |
无线电 | 26篇 |
一般工业技术 | 74篇 |
冶金工业 | 35篇 |
原子能技术 | 8篇 |
自动化技术 | 24篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 8篇 |
2020年 | 8篇 |
2019年 | 6篇 |
2018年 | 7篇 |
2017年 | 8篇 |
2016年 | 13篇 |
2015年 | 4篇 |
2014年 | 7篇 |
2013年 | 21篇 |
2012年 | 10篇 |
2011年 | 21篇 |
2010年 | 15篇 |
2009年 | 27篇 |
2008年 | 14篇 |
2007年 | 13篇 |
2006年 | 9篇 |
2005年 | 14篇 |
2004年 | 11篇 |
2003年 | 10篇 |
2002年 | 8篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 9篇 |
1998年 | 15篇 |
1997年 | 10篇 |
1996年 | 1篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1982年 | 2篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1976年 | 4篇 |
排序方式: 共有328条查询结果,搜索用时 15 毫秒
81.
Improvement of stability for organic solar cells by using molybdenum trioxide buffer layer 总被引:1,自引:0,他引:1
We demonstrated that the stability of organic solar cells (OSCs) under light irradiation is markedly enhanced by inserting a molybdenum trioxide (MoO3) buffer layer between an anode layer of indium tin oxide (ITO) and a p-type layer of 5,10,15,20-tetraphenylporphyrin (H2TPP) or N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (α-NPD). The use of the MoO3 layer also enhanced open-circuit voltages and power conversion efficiencies of the OSCs due to an increase in built-in potential. From results of stability test of hole-only α-NPD devices, we concluded that the OSC degradation occurs near the ITO/p-type layer interface and that the use of the MoO3 layer can prevent the degradation at this interface. 相似文献
82.
Noriyuki Hayashi Tetsuo Sugahara Shin‐Ichiro Tsuru Masanori Hara 《IEEJ Transactions on Electrical and Electronic Engineering》2006,1(2):194-206
A centrifugal method was used to fabricate large‐scale functionally graded materials (FGMs) from solid‐particles/viscous‐matrix mixtures at room temperature. The conventional simulation procedure of the centrifugal process was improved by considering the dependency of the viscosity η of the mixture on the packing fraction νp of particle, the effects of arbitrary shape of the actual fillers on η, the statistical dispersion of the diameters of the actual fillers, and the formation and growth of the fully packed layer (FPL) near the FGM bottom. The new simulation method was applied to three centrifugal processes employed for experimental FGM fabrications from alumina/epoxy mixtures. The numerical profiles of νp are in good agreement with the experimental ones regardless of the shapes of fillers and 'ponding viscosity of the solutions without fillers, the total amount of fillers loaded, and the centrifugal conditions. The saturating nature of νp near the far end of the FGM column is also simulated with reasonable precision. Finally, the manner in which the particles exert varying influences on the gradient of νp is demonstrated: the particles exhibit different movements depending on their size. On the basis of these results, the effectiveness of the new simulation method proposed is confirmed for the modeling of similar processes involved in the fabrication of FGMs from solid‐particles/viscous‐matrix mixtures by the centrifugal method. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
83.
84.
Yosuke Abe Tomohito Tsuru Shi Shi Naoko Oono Shigeharu Ukai 《Journal of Nuclear Science and Technology》2016,53(10):1528-1534
Various types of nanometric defects such as voids and helium (He) bubbles produced by high-energy neutron irradiations are known to degrade the mechanical properties of irradiated materials. In this study, we have evaluated the obstacle strength of He bubbles to the mobility of an edge dislocation in α-iron for 2 and 4 nm bubbles with He-to-vacancy (He/V) ratios ranging from 0 to 1 at 300 and 500 K, by molecular dynamics simulation. Results showed that as the He/V ratio increases, the obstacle strength needed for the release of a dislocation from the bubble becomes stronger up to a moderate He/V ratio (0.6 and 0.4 for 2 and 4 nm bubbles, respectively, at both temperatures), and a further increase in the He/V ratio leads to weakening of the obstacle strength. For He/V = 1, the obstacle strengths are 10–30% weaker than those at moderate He/V ratios depending on the bubble size and temperature. The extent of obstacle strength was found to be correlated with the dilation caused by He bubbles depending on the bubble size, He/V ratio, and temperature. 相似文献
85.
Norihiro Moriyama Kenji Haraya Hiroki Nagasawa Masakoto Kanezashi Toshinori Tsuru 《American Institute of Chemical Engineers》2020,66(7):e16250
Permeance and permeance ratio in binary separation generally are obtained from experimental data using an analytical permeance equation consisting of the logarithmic average of the partial pressure difference (hereafter, approximate permeance equation). The aim of the present study was to clarify the applicable range for this equation. First, the separation performance of a membrane module was calculated with various given membrane properties (permeance, permeance ratio) and operation conditions (pressure, flow rate) via numerical computation. The obtained concentrations and flow rates in the retentate and permeate were used to calculate permeances via approximate permeance equation, and the validity was discussed by comparing permeances used for numerical computation with obtained ones. The present work clarifies the validity of the approximate permeance equation, and yields a general guideline stipulating that the partial pressure difference across the membrane at the inlet and outlet should maintain more than 60% to obtain the correct permeance. 相似文献
86.
Xin Yu Lie Meng Hiroki Nagasawa Masakoto Kanezashi Masato Machida Toshinori Tsuru 《Journal of the American Ceramic Society》2019,102(11):6946-6956
The decomposition of sulfur trioxide to produce sulfur dioxide and oxygen using a catalytic membrane reactor is technology that promises to improve the economic viability of the thermochemical water-splitting Iodine-Sulfur (IS) process for large-scale CO2-free hydrogen production. The chemical stability of membrane materials under SO3, however, is a significant challenge for this strategy. In this study, microporous membranes with a layered structure that consisted of a membrane support prepared from α-Al2O3, an intermediate layer prepared from silica-zirconia, and a top layer prepared from bis (triethoxysilyl)ethane-derived organosilica sols, were examined for stability under SO3 and for use in SO3/O2 separation. An α-Al2O3 support that features SiO2–ZrO2 intermediate layers with large pore sizes and a high Si/Zr molar ratio showed excellent resistance to SO3, which was confirmed by N2 adsorption, Energy Dispersive X-ray Spectroscopy (EDS), and Scanning Electron Microscopy (SEM). These membranes also demonstrated a negligible change in gas permeance before and after SO3 exposure. Subsequently, in binary-component gas separation at 550°C, microporous organosilica-derived membranes achieved an O2/SO3 selectivity of 10 (much higher than the Knudsen selectivity of 1.6) while maintaining a high O2 permeance of 2.5 × 10−8 mol m–2 s–1 Pa–1. 相似文献
87.
Yoshinobu Nayatani Toshinori Mori Kenjiro Hashimoto Kotaro Takahama Hiroaki Sobagaki 《Color research and application》1990,15(5):272-284
The color-appearance models developed by R. W. G. Hunt (model H) and Y. Nayatoni and his collaborators (model N) are compared. The following color perceptions are analyzed: (1) colorfulness under illuminant C for NCS samples, (2) colorfulness change by changing illuminant C to illuminant A, (3) colorfulness change by changing adaptign illuminance, (4) Helson-Judd effect on achromatic colors under saturated chromatic illuminants, and (5) brightness and lightness. Special features of each model are made clear. In addition, a deatailed discussion is given on the mechanism introbucing the Helson-Judd effect and on the model formulations, especially in model H. 相似文献
88.
Yoshinori Kitatsuji Masato Tsuru Tetsuya Takine Yuji Oie 《Telecommunication Systems》2008,37(1-3):97-108
In traffic engineering (TE), it is vital to take traffic characteristics of the flows into account in appropriately assigning the flows to multiple network paths to achieve better delay performance as a whole in order to effectively distribute traffic flows over the paths. This paper presents a novel traffic characteristic-aware flow assignment method to reduce the queuing delay in a fundamental case where two types of flows with distinct traffic characteristics (e.g., burstiness) are distributed into two paths. First, we extensively analyze the queuing delays in assigning flows in the manner of various combinations of flows in terms of minimizing the worst queuing delay among two paths and show that it is not easy to find the optimal flow assignment when the paths have different bandwidths. Second, we propose an on-line flow assignment method for the different-bandwidth paths and show that the numerical simulation with the method finds a nearly optimal flow assignment and outperforms up to 40% compared with the conventional path-bandwidth-based flow assignment. Our evaluation suggests that considering the traffic characteristics in the flow distribution over multiple paths significantly improves the delay performance when the flows have distinct characteristics. 相似文献
89.
Yasuhiko Ito Kiyoshi Tsuru Jun Oishi Yoshinori Miyazaki Teruo Kodama 《Journal of power sources》1985,16(1):75-82
An Li2CO3/Na2CO3/K2CO3 eutectic melt has been selected as an example of a molten-carbonate system and the suitability of a stabilized zirconia—air electrode as an oxide-ion concentration indicator for this melt has been confirmed.With this indicator, the dissociation constant of the reaction CO32? (?) = CO2(g) + O2? (?) in this melt has been determined to be Kd = PCO2 [O2?] = 4.03 × 10?3 Pa at 873 KReproducible measurements were obtained throughout the experiment and this method might find further application in the study of reactions related to the oxide ion in carbonate melts. 相似文献
90.