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Toshiyuki Sanada Yuki Mitsuhashi Hiroya Mizutani Takayuki Saito 《Nuclear Engineering and Design》2010,240(12):3974-3983
In this study, the flow structure of a steam–water mixed spray is studied both numerically and experimentally. The velocity and pressure profiles of single-phase flow are calculated using numerical methods. On the basis of the calculated flow fields, the droplet behavior is predicted by a one-way interaction model. This numerical analysis reveals that the droplets are accelerated even after they are sprayed from the nozzle. Experimentally, the mixed spray is observed using an ultra-high-speed video camera, and the velocity field is measured by using the oarticle image velocimetry (PIV) technique. Along with this PIV velocity field measurement, the velocities and diameters of droplets are measured by phase Doppler anemometry. Furthermore, the mixing process of steam and water and the atomization process of a liquid film are observed using a transparent nozzle. High-speed photography observations reveal that the flow inside the nozzle is annular flow and that most of the liquid film is atomized at the nozzle throat and nozzle outlet. Finally, the optimum mixing method for steam and water is determined. 相似文献
64.
The isothermal crystallization process of amorphous indium tin oxide films was investigated by examining the peak intensity, obtained through high-temperature X-ray diffraction analysis. The introduction of water vapor (5 × 10− 5 Torr) during sputtering-deposition significantly reduced the rate of crystallization. This can be attributed to the presence of chemically bonded hydrogen. Classical kinetic analysis based on the Kolmogorov-Johnson-Mehl-Avrami equation indicated three distinct changes caused by the introduction of water vapor: it reduced the kinetic exponent (n) from approximately 5/2 (2.59 ± 0.12) to 3/2 (1.53 ± 0.10), increased the activation energy (Ea) from 79.9 to 116 kJ/mol, and increased the average crystallite size from 54 to 93 nm. Site-saturated and continuous nucleation models are tentatively proposed, to account for the crystallization of amorphous ITO films deposited in the presence and absence of water vapor, respectively. 相似文献
65.
Ueki Kosuke Ueda Kyosuke Nakai Masaaki Nakano Takayoshi Narushima Takayuki 《Metallurgical and Materials Transactions A》2018,49(6):2393-2404
Metallurgical and Materials Transactions A - Microstructural changes were observed during the plastic deformation of ASTM F90 Co-20Cr-15W-10Ni (mass pct) alloy heat-treated at... 相似文献
66.
In Japan, to satisfy the steadily increasing demand for electricity in urban areas, 1100 kV substation equipment have been developed, and a part of the 1100 kV transmission lines were constructed. 1100 kV substations would be located in the mountainous areas, so they must be made as compact as possible to meet installation space constraints and to harmonize with the natural environment. Thus, 1100 kV substations adopt Gas Insulated Switchgear (GIS) as the main circuit from transmission line entrance to transformer bushings. Because the substation is one of the most important items in a 1100 kV system, the equipment in 1100 kV substations requires to be of extremely high reliability. Additionally, various technologies that have not been used in 500 kV and lower systems are applied. To establish carefully the 1100 kV equipment technologies, TEPCO constructed a UHV Equipment Test Station (in the 500 kV Shin-Haruna substation), which has the minimum component of a 1100 kV substation-3 single-phase transformers (3000 MVA bank) and 1 bay of GIS (8000 A). Connecting these facilities to the actual grid in 1996, a field verification test has been carried out. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
67.
利用基于密度泛函理论的第一性原理的方法研究了超薄钛酸铅(PbTiO3)纳米管的铁电性及力电耦合特性。研究发现对于钛酸铅铁电纳米管结构, 即使在其特征尺寸小于铁电薄膜的铁电临界尺寸时, 依然存在自发极化。钛酸铅铁电纳米管结构不存在铁电临界尺寸。对纳米管力电耦合效应的研究发现, 轴向应变作用会引起包括极化沿轴向方向的铁电相、顺电相和极化沿周向方向的铁电相在内的丰富的相转变。这种相的转变是由于轴向应力所导致的Pb-O共价键的变化所引起的。另一方面, 研究了钛酸铅纳米管结构的机械强度, 明确了在轴向拉伸和压缩作用下纳米管的临界载荷。 相似文献
68.
Masami Tsubota Satoshi Hino Hironobu Fujii Chie Oomatsu Masashi Yamana Takayuki Ichikawa Yoshitsugu Kojima 《International Journal of Hydrogen Energy》2010
The possibility of using ammonia as a hydrogen carrier is examined for the reaction between magnesium ammine complex MgCl2(NH3)6 and lithium hydride LiH. Sample was milled at low temperature of −40 °C to avoid decomposition of MgCl2(NH3)6 during the milling. The effects of milling time, milling speed (revolutions per minute), and catalysts on hydrogen storage properties were investigated by thermogravimetry, thermal desorption mass spectroscopy, and X-ray diffraction experiments. Experimental results indicated that a milled composite of Mg(NH3)6Cl2 and catalyzed-LiH desorbed the ∼100% H2 gas even at 125 °C in a closed system. The reverse reaction also proceeded by separately cooling MgCl2 at lower temperature than 100 °C and heating LiNH2 at 300 °C in the closed system. 相似文献
69.
Takashi Sasaoka Hideki Shimada Takayuki Sasaki Masatomo Ichinose Kikuo Matsui 《煤炭学报(英文版)》2008,14(3):365-368
The size distribution of a muck pile depends not on only the blasting standard but also on the mechanical properties, joint
system, and crack density of the rock mass. As, the cracks in the rock masses are especially heavily developed at the limestone
quarries in Japan, they, along with the joints, have a large impact on the effects of blasting, such as the size of the muck
pile. Therefore, if the joint system and/or crack density in a rock mass can be determined and quantitatively evaluated, the
blasting operation can be conducted more effectively, efficiently and safely. However, guidelines for designing appropriate
blasting standards based on the rock mass conditions have not yet been scientifically developed. Therefore, blasting tests
were conducted on different mines and faces, under different geological conditions and blasting standards, in order to determine
the impacts of each factor on the effects of blasting. Summarized the results of a series of blasting tests and described
the impacts of geological conditions on the size of the muck pile produced by blast.
Bhandari S. Engineering rock blasting operations, 1997. 相似文献
70.
Shin-ichi Shimakawa Yasuhiro Hashimoto Shigeo Hayashi Takuya Satoh Takayuki Negami 《Solar Energy Materials & Solar Cells》2008,92(9):1086-1090
Annealed Zn1−xMgxO/Cu(In,Ga)Se2 (CIGS) interfaces have been characterized by ultraviolet light excited time-resolved photoluminescence (TRPL). The TRPL lifetime of the Zn1−xMgxO/CIGS film increased on increasing the annealing temperature to 250 °C, whereas the TRPL lifetime of the CdS/CIGS film had little change by annealing at temperatures lower than 200 °C. This is attributed to the recovery of physical damages by annealing, induced by sputtering of the Zn1−xMgxO film. The TRPL lifetime abruptly decreased with annealing at 300 °C. The diffusion of excess Zn from the Zn1−xMgxO film into the CIGS interface is clearly observed in secondary ion mass spectroscopy (SIMS) depth profiles. These results indicate that excess Zn at the vicinity of the CIGS surface acts as non-radiative centers at the interface. The TRPL lifetime of the Zn1−xMgxO/CIGS film annealed at 250 °C reached values to be comparable to that of the as-deposited CdS/CIGS film. Performance of the Zn1−xMgxO/CIGS cells varied with the annealing temperature in the same manner as the TRPL lifetime. The highest efficiency of the Zn1−xMgxO/CIGS solar cells was achieved for annealing at 250 °C. The results of the TRPL lifetime on annealing show that the cell efficiency is strongly influenced by the Zn1−xMgxO/CIGS interface states related to the damages and diffusion of Zn. 相似文献