全文获取类型
收费全文 | 1158篇 |
免费 | 22篇 |
国内免费 | 12篇 |
专业分类
电工技术 | 105篇 |
综合类 | 4篇 |
化学工业 | 399篇 |
金属工艺 | 30篇 |
机械仪表 | 28篇 |
建筑科学 | 30篇 |
能源动力 | 63篇 |
轻工业 | 116篇 |
水利工程 | 1篇 |
无线电 | 55篇 |
一般工业技术 | 228篇 |
冶金工业 | 22篇 |
原子能技术 | 30篇 |
自动化技术 | 81篇 |
出版年
2023年 | 9篇 |
2022年 | 6篇 |
2021年 | 19篇 |
2020年 | 4篇 |
2019年 | 8篇 |
2018年 | 19篇 |
2017年 | 15篇 |
2016年 | 20篇 |
2015年 | 12篇 |
2014年 | 17篇 |
2013年 | 60篇 |
2012年 | 35篇 |
2011年 | 47篇 |
2010年 | 42篇 |
2009年 | 73篇 |
2008年 | 50篇 |
2007年 | 68篇 |
2006年 | 53篇 |
2005年 | 53篇 |
2004年 | 57篇 |
2003年 | 46篇 |
2002年 | 38篇 |
2001年 | 36篇 |
2000年 | 41篇 |
1999年 | 23篇 |
1998年 | 23篇 |
1997年 | 23篇 |
1996年 | 26篇 |
1995年 | 23篇 |
1994年 | 15篇 |
1993年 | 19篇 |
1992年 | 15篇 |
1991年 | 15篇 |
1990年 | 9篇 |
1989年 | 15篇 |
1988年 | 11篇 |
1987年 | 16篇 |
1986年 | 21篇 |
1985年 | 19篇 |
1984年 | 11篇 |
1983年 | 13篇 |
1982年 | 11篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 14篇 |
1977年 | 7篇 |
1976年 | 5篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 3篇 |
排序方式: 共有1192条查询结果,搜索用时 0 毫秒
71.
Sujittra Charoenhirunyingyos Kiyoshi Honda Daroonwan Kamthonkiat Amor V. M. Ines 《International journal of remote sensing》2013,34(23):8033-8051
Leaf area index (LAI) and actual evapotranspiration (ETa) from satellite observations were used to estimate simultaneously the soil hydraulic parameters of four soil layers down to 60 cm depth using the combined soil water atmosphere plant and genetic algorithm (SWAP–GA) model. This inverse model assimilates the remotely sensed LAI and/or ETa by searching for the most appropriate sets of soil hydraulic parameters that could minimize the difference between the observed and simulated LAI (LAIsim) or simulated ETa (ETasim). The simulated soil moisture estimates derived from soil hydraulic parameters were validated using values obtained from soil moisture sensors installed in the field. Results showed that the soil hydraulic parameters derived from LAI alone yielded good estimations of soil moisture at 3 cm depth; LAI and ETa in combination at 12 cm depth, and ETa alone at 28 cm depth. There appeared to be no match with measurement at 60 cm depth. Additional information would therefore be needed to better estimate soil hydraulic parameters at greater depths. Despite this inability of satellite data alone to provide reliable estimates of soil moisture at the lowest depth, derivation of soil hydraulic parameters using remote sensing methods remains a promising area for research with significant application potential. This is especially the case in areas of water management for agriculture and in forecasting of floods or drought on the regional scale. 相似文献
72.
Catalin Popa Yuki Okayasu Ken-ichi Katsumata Toshihiro Isobe Nobuhiro Matsushita Akira Nakajima Taisuke Kurata Kiyoshi Okada 《Journal of Materials Science》2013,48(2):941-947
Porous mullite ceramics with unidirectionally oriented pores were prepared by an extrusion method using rayon fibers as the pore formers. Rayon fibers of 8.1, 9.6, 16.8, and 37.6 μm in diameter were used as the pore formers and were kneaded with alumina powder, kaolin clay, China earthen clay, and water to form pastes. These pastes were extruded into cylindrical tubes, dried, and fired at 1500 °C for 4 h. The apparent porosities ranged from 45.7 to 48.2 %. The pore size distributions showed a sharp peak at 9.4, 10.0, 15.6, and 30 μm with increasing fiber diameters. The height of the capillary rise was 1780, 1670, 1320, and 950 mm with increasing fiber diameter. The maximum capillary rise is much higher than previously reported. The contact angle and effective pore radius that determine the capillary rise ability were calculated by fitting the capillary rise curves using the Fries and Dreyer’s equation. 相似文献
73.
Kiyoshi Minoura Shigeaki Mizushima Yasushi Asaoka Ichiro Ihara Eiji Satoh Sayuri Fujiwara Yasuhisa Itoh 《Journal of the Society for Information Display》2008,16(1):129-136
Abstract— A novel reflective color LCD without polarizers has been developed using a PDLC film and a retro‐reflector. Bright color images including moving images are achievable with ambient light. This novel LCD will enable the new application area of electronic paper. 相似文献
74.
Mikio Fukuhara Yoshiyuki Kuwano Kiyoshi Saito Taiji Hirasawa Ichiro Komura 《NDT & E International》1998,31(3):211-216
The degree of fatigue in ferritic wrought steel during cyclic bending was determined by analysis of diffracted SH ultrasonic waves with the aid of multiple regression analysis. As the degree of fatigue increases, accompanied by residual stress, the incident waves curve to the interior region with positive stress field owing to the acoustoelastic effect. As a result, the propagation time of the launched waves lengthens, leading to a modulation of the received waveform. Multiple regression analysis for the waveform modulation produces a reliable estimation, with correlation coefficient of 0.948, for the degree of fatigue. 相似文献
75.
Yoshihiro Imai Tadashi Tokumasu Hidehiro Nagamura Kiyoshi Miyaike Hisakazu Matsumoto Hiroshi Hasegawa Hiroshi Kusafuka Masatoyo Shibuya Ryukichi Takahashi 《Electrical Engineering in Japan》2007,160(2):30-38
In the combined‐cycle power plant generators are started by using the igniting arrangement up to the ignition rotational speed of the gas turbine. On the other hand, in the case of using the superconducting generator, it is difficult to apply the igniting arrangement used to generate electricity on the combined cycle for the structure as is. We examined the induction motor starting method for the superconducting generator by using the 70‐MW‐class quick‐response excitation superconducting model generator and the VVVF power supply. From the examination, we confirmed the ability to raise the rotational speed from 6 to 360 rpm. Moreover, it was found to be able to start 200‐MW‐class superconducting generators by the induction motor starting method with the analysis. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 160(2): 30– 38, 2007; Published online in Wiley InterScience ( www.interscience. wiley.com ). DOI 10.1002/eej.20283 相似文献
76.
77.
Hong Chen Ryozo Ooka Kazuo Iwamura Hong Huang Nobufusa Yoshizawa Kiyoshi Miisho Satoshi Yoshida Sanae Namatame Atsushi Sakakura Syunichi Tanaka 《Energy and Buildings》2008,40(5):782-792
“Distributed local energy systems” had been expected to rationalize the supply of energy to built-up areas, but until now very little research has been performed to estimate the effect of their application to actual cities. In this research, therefore, a future vision for the year 2030 in the Sancha Area (SANCHA VISION 2030), a typical densely built-up area in Tokyo, has been elaborated including a simulation to estimate benefits from the application of distributed energy systems in terms of reduced energy consumption and CO2 emissions as well as mitigation of the heat-island phenomenon. As a result, it was demonstrated that a “distributed local energy system”, which provides a district with both electrical power and heat through an integrated distribution system, may contribute to a considerable improvement in energy efficiency for those areas. In addition, it may also provide other benefits, including enhancement of living amenity and urban security in times of emergency. 相似文献
78.
Two kinds of composites—Ti-Ni shape-memory alloy (SMA) fiber-reinforced 6061 aluminum matrix composite and Ti-Pd(Ni) SMA-reinforced
titanium-matrix composite—were fabricated by various processing methods and their microstructure and thermomechanical behavior
were investigated. In both sets of composites, an increase in yield stress at high temperature was mainly caused by residual
compressive stress created in the matrix in association with shape-memory effects of the embedded SMAs.
For more information, contact Kiyoshi Mizuuchi, Osaka Municipal Technical Research Institute, Osaka 536-8553, Japan; e-mail:
mizuuchi@omtri.city.osaka.jp. 相似文献
79.
Sinterability of various high-purity magnesium oxide powders 总被引:3,自引:0,他引:3
Kiyoshi Itatani Masayuki Nomura Akira Kishioka Makio Kinoshita 《Journal of Materials Science》1986,21(4):1429-1435
The sinterability of high-purity MgO powders with different production histories was investigated to make clear the relationship between the powder characterization, the densification processes, and the changes in microstructure both with increasing temperature at a rate of 10° C min–1 and at a fixed temperature of 1450° C for 5 h. The densification behaviour and the changes in microstructure of these compressed bodies were affected chiefly by their original surface activity and degree of agglomeration, depending on the production histories: (i) the ultra-fine and well-dispersed powder prepared by the vapour-phase oxidation process showed that densification proceeded with an appreciable grain growth with few closed pores remaining; (ii) powder derived from the sea-water magnesia process showed that the densification behaviour was affected by the species of magnesium salt, i.e. basic magnesium carbonate or magnesium hydroxide, used as a precursor; however, whichever magnesium salt was used, its sintered compact showed similar closed porosities and grain-size distributions; (iii) powder derived from the spark-discharge process contained skeletons of the original Mg(OH)2 particles; however, the densification proceeded gradually with slow grain growth, reflecting the fact that the powder has a moderate surface area (36 m2 g–1). The sintered compact from (iii) had a small closed porosity and the smallest grain-size distribution among the compacts used in this investigation. 相似文献
80.
In the present study, an electrochemical sensor has been designed for the direct measurement of silicon content in hot metal. The sensor represents a galvanic silicon concentration cell of the type Nisat—Si(1) II silicate electrolyte (1) II Fe—C—Si(1) The tubular silica-glass sensor can be immediately immersed into the metal bath at a response time of 30 to 60 s. A reproducible EMF vs. wt.% Si relationship was obtained for measurements in carbon-saturated Fe—C—Si melts at 1400°C and Si contents from 0.05 to 1.8 wt.%. This relationship is nearly identical with the cell function calculated from thermodynamic data. 相似文献