全文获取类型
收费全文 | 727篇 |
免费 | 7篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 46篇 |
化学工业 | 107篇 |
金属工艺 | 24篇 |
机械仪表 | 14篇 |
建筑科学 | 14篇 |
能源动力 | 13篇 |
轻工业 | 45篇 |
水利工程 | 3篇 |
无线电 | 96篇 |
一般工业技术 | 128篇 |
冶金工业 | 207篇 |
原子能技术 | 22篇 |
自动化技术 | 17篇 |
出版年
2023年 | 2篇 |
2022年 | 12篇 |
2021年 | 14篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 6篇 |
2017年 | 6篇 |
2016年 | 7篇 |
2015年 | 9篇 |
2014年 | 15篇 |
2013年 | 24篇 |
2012年 | 14篇 |
2011年 | 22篇 |
2010年 | 19篇 |
2009年 | 13篇 |
2008年 | 17篇 |
2007年 | 23篇 |
2006年 | 21篇 |
2005年 | 24篇 |
2004年 | 18篇 |
2003年 | 19篇 |
2002年 | 15篇 |
2001年 | 26篇 |
2000年 | 13篇 |
1999年 | 16篇 |
1998年 | 83篇 |
1997年 | 48篇 |
1996年 | 41篇 |
1995年 | 28篇 |
1994年 | 16篇 |
1993年 | 22篇 |
1992年 | 6篇 |
1991年 | 11篇 |
1990年 | 17篇 |
1989年 | 7篇 |
1988年 | 11篇 |
1987年 | 7篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 13篇 |
1982年 | 3篇 |
1981年 | 9篇 |
1980年 | 8篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1976年 | 10篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1971年 | 2篇 |
排序方式: 共有736条查询结果,搜索用时 15 毫秒
111.
I.Vinyar A.Geraud H.Yamada R.Sakamoto Y.Oda A.Lukin A.Umov S.Skoblikov G.Gros G.Saksaganskii P.Reznichenko I.Krasilnikov V.Panchenko 《等离子体科学和技术》2004,6(3):2286-2290
Pneumatic and centrifugal injectors for steady-state plasma refuelling by solid hydrogen, deuterium and tritium pellets have been designed at the PELIN Laboratory to meet requirements of LHD, TORE SUPRA, and ITER. Presented here is a review of these injectors‘ designs and results. 相似文献
112.
Increased remineralization of tooth enamel by milk containing added casein phosphopeptide-amorphous calcium phosphate 总被引:1,自引:0,他引:1
Walker G Cai F Shen P Reynolds C Ward B Fone C Honda S Koganei M Oda M Reynolds E 《The Journal of dairy research》2006,73(1):74-78
Casein phosphopeptide amorphous calcium phosphate nano-complexes (CPP-ACP) in chewing gum, lozenges and mouthrinses have been shown to re-mineralize enamel subsurface lesions in human in situ experiments. The aim of this double-blind, randomized clinical study was to investigate the capacity of CPP-ACP added to bovine milk to re-mineralize enamel subsurface lesions in situ. Ten subjects drank milk containing either 2.0 or 5.0 g CPP-ACP/l or a control milk whilst wearing removable appliances with enamel slabs containing subsurface demineralized lesions. Each 200 ml milk sample was consumed once a day for each weekday over three consecutive weeks. After each treatment and one weeks rest the subjects crossed over to the other treatments. At the completion of the treatments the enamel slabs were removed and remineralization determined using microradiography and microdensitometry. The results demonstrated that all three milk samples re-mineralized enamel subsurface lesions. However, the milk samples containing CPP-ACP produced significantly greater remineralization than the control milk. The re-mineralizing effect of CPP-ACP in milk was dose-dependent with 2.0 and 5.0 g CPP-ACP/l producing an increase in mineral content of 70 and 148%, respectively, relative to the control milk. The differences in remineralization following exposure to the three milk samples were all statistically significant (P<0.001). In conclusion, this study shows that the addition of 2.0-5.0 g CPP-ACP/l to milk substantially increases its ability to re-mineralize enamel subsurface lesions. 相似文献
113.
N. Momono T. Kurosawa Y. Amakai Y. Sato T. Suzuki H. Takano S. Murayama A. Sakai M. Oda M. Ido 《Journal of Superconductivity and Novel Magnetism》2010,23(5):785-787
The Raman scattering experiments were carried out in Zn-doped and Zn-free Bi2Sr2CaCu2O8+y
with optimal hole concentration below and above T
c
. The energy of pair-breaking peak in the B
1g
Raman spectrum, corresponding to the magnitude of superconducting gap 2Δ
0, is suppressed by 1% Zn-doping. In the normal state, the B
1g
Raman spectrum for Zn-doped sample shows no pseudogap behaviour, suggesting that the pseudogap is strongly smeared by Zn-doping. 相似文献
114.
To investigate the effects of hydrogen on crack propagation in the extremely low growth rate range, fully reversed bending fatigue tests were performed on low carbon steel (JIS S10C) in hydrogen and in nitrogen gas environments at a low pressure. A crack showed almost the same non-propagation behavior in nitrogen as that in air. However, a crack in hydrogen continued to propagate even near $10^{7}$ cycles in the same testing strain range as that in nitrogen. In hydrogen gas, a crack grew intermittently by coalescing with a new micro-crack generated by slip behavior. This implies that hydrogen could inhibit the action of any factor affecting non-propagation. 相似文献
115.
Yoshinao Mishima 《Science and Technology of Advanced Materials》2013,14(4):533-535
A new doctoral course, Project Managing Course, has been established as of April, 2003 for the graduate students in the four Departments involved in the 21st Century COE program supported by Japanese Government. The aim of the course is to let selected doctoral students learn the basic knowledge and skill necessary to bring the technology seeds into the business. Besides the requirement for the thesis work for their doctoral degree of Materials Science, they have to fulfill the unit requirements on the lectures offered by guest professors who are currently active at the front of financing, market analysis, venture capitals and technology management consulting. The attempt is unique in Management of Technology (MOT) education in Japan, probably even world-wide, in a sense that the course is offered to the doctoral students. 相似文献
116.
Takayuki Kobayashi Akihiko Isayama Koichi Hasegawa Sadaaki Suzuki Shinichi Hiranai Fumiaki Sato Kenji Wada Kenji Yokokura Mitsugu Shimono Masayuki Sawahata Masayuki Terakado Jun Hinata Koji Takahashi Ken Kajiwara Yasuhisa Oda Keishi Sakamoto Katsumichi Hoshino Shinichi Moriyama 《Fusion Engineering and Design》2011,86(6-8):763-767
Structural, mechanical and optical design work on antennas/launchers for the electron cyclotron range of frequency heating and current drive system in JT-60 Super Advanced (JT-60SA) have been advanced based on a linear motion antenna concept. A CAD model of the launcher was built with realistic component sizes. A mock-up of the steering structure consisting of two different bellows sections for poloidal and toroidal beam scanning was fabricated to test movement of the bellows. The poloidal (?40° to +20°) and toroidal (?15° to +15°) injection angle ranges required in JT-60SA were shown to be realized by this steering structure and mirrors. 相似文献
117.
Makoto Shiota Toshiaki Uchida Taishi Oda Hiroshi Kawakami 《Journal of food science》2006,71(3):C120-C123
ABSTRACT: We investigated the oxidative stability of soybean oil and fish oil fortified with iron solubilized by lactoferrin (FeLF). Oxidative stability was evaluated by measuring the induction period of the Rancimat test. The induction time of soybean oil added FeCl3 was decreased; however, that of added FeLF was not. This effect of lactoferrin was also observed in the iron-catalyzed oxidation offish oil at temperatures ranging from 50°C to 120°C, and at concentrations of iron ranging from 0 to 500 ppm. Thus, lactoferrin is considered useful as a natural iron stabilizer for food products containing polyunsaturated fatty acids. 相似文献
118.
119.
The existence states of deuterium in LiAlO2 were analyzed by in situ IR absorption spectroscopy during irradiation with 3 keV at room temperature. Multiple IR absorption peaks that were related to O-D stretching vibrations were observed, mainly at 2650 cm−1 (O-Dα), 2600 cm−1 (O-Dβ), and 2500 cm−1 (O-Dγ). The O-Dα was assigned to the surface O-D. The O-Dβ and O-Dγ were interpreted as two distinct O-D states for three candidates: O-D of substitutional D+ for Li+; O-D of substitutional D+ for Al3+; and O-D of interstitial D+. O-Dβ was the dominant O-D state for deuterium irradiated into LiAlO2, and had higher stability than O-Dγ. Heating after ion irradiation led to the desorption of D2 and an increase in the intensity of O-Dβ, which implies that some of the deuterium irradiated into LiAlO2 exists in non-O-D states, such as D− captured by F centers. 相似文献
120.
Effects of the base layer in Si3N4/SiON stack gate dielectrics, in particular, the physical thickness of the base layer, on the dielectric reliability, MOSFET performance and process controllability are investigated. It is found that the electrical characteristics such as TDDB lifetime as well as the Si3N4 film property in Si3N4/SiON stack dielectrics with the same capacitance oxide equivalent thickness strongly depend on the SiON-base layer thickness. From the TDDB measurements for both stress polarities and from the Si3N4 stoichiometry by the X-ray photoelectron spectroscopy analysis, the optimum SiON-base layer thickness is determined to be approximately 1 nm, in order to obtain longer TDDB lifetime and surperior n-ch MOSFET performance. The obtained results are considered to attribute to the nitrogen profile in the Si3N4/SiON stack dielectrics and the strained layer thickness near SiON/Si interface. 相似文献