全文获取类型
收费全文 | 204篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 18篇 |
化学工业 | 64篇 |
金属工艺 | 8篇 |
机械仪表 | 6篇 |
建筑科学 | 2篇 |
能源动力 | 5篇 |
轻工业 | 21篇 |
无线电 | 8篇 |
一般工业技术 | 39篇 |
冶金工业 | 9篇 |
原子能技术 | 4篇 |
自动化技术 | 23篇 |
出版年
2023年 | 1篇 |
2022年 | 5篇 |
2021年 | 8篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 6篇 |
2015年 | 3篇 |
2014年 | 2篇 |
2013年 | 11篇 |
2012年 | 7篇 |
2011年 | 13篇 |
2010年 | 5篇 |
2009年 | 9篇 |
2008年 | 9篇 |
2007年 | 7篇 |
2006年 | 7篇 |
2005年 | 10篇 |
2004年 | 6篇 |
2003年 | 12篇 |
2002年 | 5篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 6篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 7篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1993年 | 7篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 7篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 3篇 |
排序方式: 共有207条查询结果,搜索用时 0 毫秒
31.
Yasuhiro Yamada Hajime Yasuda Kazumasa Murota Masashi Nakamura Toshiaki Sodesawa Satoshi Sato 《Journal of Materials Science》2013,48(23):8171-8198
X-ray photoelectron spectroscopy (XPS) is among the most powerful methods to determine the surface chemical properties of carbon materials. Because heat-treated graphite oxide includes various defects, analyses of the structure by XPS help us understand the structures of various carbon materials. Thus, XPS spectra of graphene-related materials containing various functional groups and other defects on edges and in the basal plane were simulated and full width at half maximums (FWHMs) and peak shifts were obtained by density functional theory calculation. Shifts of whole C1s spectra were influenced by the electron-withdrawing functional groups such as C=O-containing functional groups. FWHMs of the main peak of C1s spectra were influenced by mainly electron-withdrawing functional groups in addition to defects such as vacancy, pentagons, and heptagons. Analyses using only XPS provide us limited information, even though the peak tops and FHWMs of simulated XPS spectra are used for assignment. Combination use of peak shifts and FWHMs of XPS spectra, infrared spectroscopy, and density functional theory calculation provided more reliable assignments of defects including oxygen-containing functional groups of carbon materials than commonly used methods using only peak shifts of XPS spectra. 相似文献
32.
An active optical access network architecture with our newly developed PLZT ((Pb,La)(Zr,Ti)O3) high-speed optical switch is introduced, with a view to realizing the next-generation high capacity scalable access network. This system is developed based on the latest IEEE standard of PON (10G-EPON; IEEE802.3av) in consideration of the coordination with future high capacity PON. PLZT high-speed optical switches are able to switch an optical signal at nano-second speed (<5-10 ns). Generally, the merits of using optical switches are increasing the number of subscribers and transmission distance easily, preventing malicious ONUs from interfacing with the communication between OLT and the other ONUs, realizing fast fiber and OLT protection/restoration and providing various services by controlling optical switches dynamically. This paper focuses on two key technologies; a PLZT optical switch and a new discovery process for active optical access network based on MPCP defined at IEEE802.3. A major challenge in designing active optical access network is supporting the discovery process of MPCP because it does not offer broadcast transmission unlike the regular PON. We propose here a new discovery process; it has been tested successfully in an implementation of our proposed system. 相似文献
33.
Hideo Noda Takeichiro Takamatsu Kazumasa Aso Tosinari Nakanishi Kazufumi Yoshida Masaru Nakaiwa Tadahiro Mukaida Nobuyuki Kuratani 《Korean Journal of Chemical Engineering》2000,17(5):593-596
Various configurations of a column for performing the principle of HIDiC can be proposed, but a coaxial column which is installed
a packing in an inside tube and outer side may be one of the simplest columns for HIDiC. In order to examine whether or not
the configuration of the packed column mentioned above is appropriate to HIDiC, an experimental apparatus has been set up
and heat and mass transfer rates have been measured by using benzene-toluene system.
This paper was presented at The 5th International Symposium on Separation Technology-Korea and Japan held at Seoul between
August 19 and 21, 1999. 相似文献
34.
A prototype 3 kW horizontal upwind type wind turbine generator of 4 m in diameter has been designed and examined under real wind conditions. The machine was designed based on the concept that even small wind turbines should have a variable pitch control system just as large wind turbines, especially in Japan where typhoons occur at least once a year. A characteristic of the machine is the use of a worm and gear system with a stepping motor installed in the center of the hub, and the rotational main shaft. The machine is constructed with no mechanical breaking system so as to avoid damage from strong winds. In a storm, the wind turbine is slowed down by adjusting the pitch angle and the maximum electrical load. Usually the machine is controlled at several stages depending on the rotational speed of the blades. Two control methods have been applied: the variable pitch angle, and regulation of the generator field current. The characteristics of the generator under each rotational speed and field current are first investigated in the laboratory. This paper describes the performances of the wind turbine in terms of the functions of wind turbine rotational speed, generated outputs, and its stability for wind speed changes. The expected performances of the machine have been confirmed under real wind conditions and compared with numerical simulation results. The wind turbine showed a power coefficient of 0.257 under the average wind speed of 7.3 m/s. 相似文献
35.
Kanichi Kamiya Toshinobu Yoko Keiji Moroishi Kazumasa Matusita Sumio Sakka 《Journal of Materials Science》1986,21(1):131-136
The behaviour of copper ions in low thermal expansion glass-ceramics prepared from Cu2O · Al2O3 ·nSiO2 glasses, or in-spodumene type Cu2O · Ae2O3 ·nSiO2 crystals included in the glass-ceramics on heating in air was investigated. On hewing at 300 to 500° C, the copper ions behaved as in the corresponding glasses. Cuprous ions in the glass-ceramics or-spondumene type crystals were oxidized into the cupric state, and at the same time an equal amount of cuprous ions to those oxidized were expelled out of the specimen for the requirement of electrical charge neutrality and then reacted with oxygen to form CuO on the surface. The oxidation of cuprous ions and the decrease of the copper content of the-spondumene type crystals brought about a considerable decrease in the lattice spooings. 相似文献
36.
Gaigo Kato Kazumasa Takahashi Takashi Kikuchi Toru Sasaki 《Electrical Engineering in Japan》2023,216(3):e23440
We have demonstrated a capacitively coupled Hall-type MHD generator using ECR plasma. To clarify the characteristics of the fabricated MHD generator, we measured the power generation characteristics as a function of magnetic field strength using a DC Hall-type MHD power generation experiment. The results showed that the output power decreased due to magnetic pressure at the higher magnetic field. However, the output power corresponded to the theoretical value at the lower magnetic field. An AC Hall-type MHD power generation experiment was conducted using an AC magnetic field. As a result, full-wave rectification voltage was observed as per theory. Finally, capacitively coupled Hall-type MHD power generation experiments were conducted, and full-wave rectified waveforms were observed as in AC Hall-type MHD power generation. These waveforms were similar to the output waveforms predicted from theory. These results show that the capacitively coupled Hall-type MHD generator is feasible. 相似文献
37.
38.
Kazumasa Narumi Yoshikazu Fujii Kenji Kimura Michi-hiko Mannami 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》1994,90(1-4):266-269
The angular distributions and the energy spectra of scattered H+ ions are studied at glancing angle incidence of 30 keV H+ ions on the (001) surface of KCl single crystal. Discrete energy loss spectra of the scattered ions are observed. The observed exit angle distributions of the ions which have lost anomalous large amounts of energy at various angles of incidence do not depend on the angle of incidence. From the observed results, it is concluded that skipping motion occurs on the surface of KCl. 相似文献
39.
Hitoshi Kitaguchi Hiroaki Kumakura Kazumasa Togano Tsukasa Kiyoshi Kiyoshi Inoue Hiroshi Maeda Naruaki Tomita Junichiro Kase Eiji Yanagisawa Koki Kato 《Journal of Electronic Materials》1995,24(12):1883-1886
We fabricated a Bi-2212/Ag double stacked pancake coil of 13 mmØ) in inner bore and of 46.5 mmØ in outer diameter, by using Bi-2212/Ag tapes prepared by the combination of continuous dip-coating process and melt-solidification technique. This small superconducting magnet was used as an insert magnet of a conventional superconducting magnet system and tested at saturated superfluid helium temperature (~ 1.8K) in various bias fields. The generated field of Bi2212/Ag coil was 0.9 T, with Ic of 310 A(criterion 10-13Ω·m), in the bias field of 20.9 T. Thus, this superconducting magnet system achieved generation of magnetic field of 21.8 T in the full superconducting state. 相似文献
40.
We have successfully fabricated molecular rings of (n-Bu4N)2[(dcbdt)2VO] (dcbdt = 4,5-dicyanobenzene-1,2-dithiolato) and (n-Bu4N)[(dmit)2Zn] (dmit = 2-thioxo-1,3-dithiole-4,5-dithiolate) on a silicon substrate using simple and easy deposition method under ambient
or highly humidified conditions. For (n-Bu4N)2[(dcbdt)2VO] changing the process from ambient to highly humidified condition diminishes the size of molecular rings by 10 times smaller.
Furthermore each molecular ring has same crystallinity as the corresponding single crystal. 相似文献