全文获取类型
收费全文 | 489篇 |
免费 | 16篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 22篇 |
综合类 | 1篇 |
化学工业 | 151篇 |
金属工艺 | 27篇 |
机械仪表 | 16篇 |
建筑科学 | 3篇 |
能源动力 | 14篇 |
轻工业 | 37篇 |
石油天然气 | 1篇 |
无线电 | 17篇 |
一般工业技术 | 128篇 |
冶金工业 | 58篇 |
原子能技术 | 6篇 |
自动化技术 | 28篇 |
出版年
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 4篇 |
2018年 | 10篇 |
2017年 | 14篇 |
2016年 | 13篇 |
2015年 | 7篇 |
2014年 | 9篇 |
2013年 | 40篇 |
2012年 | 21篇 |
2011年 | 42篇 |
2010年 | 26篇 |
2009年 | 35篇 |
2008年 | 28篇 |
2007年 | 27篇 |
2006年 | 23篇 |
2005年 | 15篇 |
2004年 | 17篇 |
2003年 | 15篇 |
2002年 | 12篇 |
2001年 | 11篇 |
2000年 | 14篇 |
1999年 | 12篇 |
1998年 | 17篇 |
1997年 | 14篇 |
1996年 | 3篇 |
1995年 | 14篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1984年 | 1篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 7篇 |
1974年 | 1篇 |
排序方式: 共有509条查询结果,搜索用时 0 毫秒
1.
2.
Nobukazu Kinomura Kiyoshi Onda Masayuki Kobayashi Nobuhiro Kumada Fumio Muto 《Journal of Materials Science》1989,24(5):1814-1818
Ion exchange of Na
x
WOP2O7 ·nH2O (x 1.4) prepared from WOP2O7 was attempted, using alkaline and alkaline earth ions. The degree of exchange was observed to be >50% at 90° C except for Mg2+. The basal spacing of ion-exchanged materials for the hydrated phase were dependent on the number of water molecules in the interlayer spaces, while those for the dehydrated phase increased with the size of ions in the interlayer spaces. The network of water molecules linked by the hydrogen bond in the interlayer spaces seems to determine the basal spacing. By the ion-exchange reaction,n-alkylammonium ions were intercalated into the interlayer spaces of Na
x
WOP2O7 ·nH2O (x 1.4) and Sn
x
H
y
WOP2O7 ·nH2O (2x +y 0.5). In spite of the difference in the charge density of the host layer, a similar arrangement of alkyl chains in the interlayer spaces resulted, and neutral amines were considered to be intercalated as well as ammonium ions. Direct reaction ofn-alkylamine with WOP2O7 produced an intercalation compound without reduction of tungsten. The arrangement of the amines in the interlayer spaces is similar to that supposed to the ion-exchanged derivatives when heated at 140° Cin vacuo. 相似文献
3.
Upper and lower critical solution temperatures have been determined for solutions of poly(ethylene glycol) in t-butyl acetate and water over the molecular weight range of Mη = 2.18 × 103 to ~1020 × 103. The phase diagram for solutions of poly(ethylene glycol) (Mη = 719 × 103) in t-butyl acetate was expressed as the ‘hour glass’ type, while the phase diagram for solution of poly(ethylene glycol) (Mη = 2.18 × 103 to ~2.29 × 103) in water was expressed as the ‘closed loop’ type. The value of the pressure dependence of the lower critical solution temperature in the poly(ethylene glycol) (Mη = 1020 × 103)/water system over the pressure range of 0 to ~50 atm was negligibly small and positive. 相似文献
4.
Satoru Iwamori Takehiro Miyashita Shin Fukuda Shouhei Nozaki Nobuhiro Fukuda Kazufuyu Sudoh 《The Journal of Adhesion》1997,63(4):309-321
Peel strength between a copper (Cu) thin film and a polyimide (pyromellitic dianhydride-oxydianiline, or PMDA-ODA) substrate is reduced by heat treatment at 150°C in air. In this work, we investigated the peel strength, the morphology of the interface between Cu films and polyimide substrates using optical microscopy and electron microscopy, and chemical change of the interface using Auger electron spectroscopy (AES) and micro X-ray photoelectron spectroscopy (XPS). The analysis showed that CuO “lumps” were present on the peeled surface of PMDA-ODA after heat treatment at 150°C in air. The peeled surfaces of other polyimide substrates were also analyzed: biphenyl dianhydride-para phenylene diamine (BPDA-PDA) and biphenyl dianhydride-oxydianiline (BPDA-ODA). CuO lumps were present on the peeled surface of BPDA-ODA after the heat treatment, but not that of BPDA-PDA. Compared with the adhesion strength for the Cu thin film, the adhesion strength was high for the Cu/PMDA-ODA and Cu/BPDA-ODA laminates, but the adhesion strength was very low for the Cu/BPDA-PDA laminate. This low strength is the reason that CuO lumps were not detected on the peeled surface of the BPDA-PDA substrate. These CuO lumps were related to the adhesion degradation of the Cu/polyimide laminates after the heat treatment. 相似文献
5.
Lijia Zhao Nokeun Park Yanzhong Tian Akinobu Shibata Nobuhiro Tsuji 《Advanced Engineering Materials》2018,20(7)
6.
Keisuke Ichida Kiyotaka Izumi Keigo Watanabe Nobuhiro Uchida 《Artificial Life and Robotics》2008,12(1-2):258-263
In general, manipulators used for industry and in academic laboratories have actuators to drive each joint. On the other hand,
underactuated manipulators handled by our research have some passive or free joints without actuators and brakes. We recently
developed a switching method of fuzzy energy regions to control such manipulators. In such a method, it is necessary to design
parameters related to energy regions and the gains of some partly stable controllers based on the computed torque method.
Here, the switching method is applied for a three-link underactuated manipulator. We optimize such design parameters related
to fuzzy energy regions by a genetic algorithm. The effectiveness of the present method is illustrated with some simulations.
This work was presented in part at the 12th International Symposium on Artificial Life and Robotics, Oita, Japan, January
25–27, 2007 相似文献
7.
Focused electron beam induced chemical vapor deposition was performed in a scanning electron microscope with a field emission
gun using a precursor of iron carbonyl. Due to the longer deposition time and higher gas pressure than those of our previous
electron beam-induced deposition method, a new type of deposition occurred. A large amount of nanosized crystals were produced
around the focused beam irradiation point on a carbon substrate at room temperature. The nanocrystals were systematically
characterized using transmission electron microscopy with electron energy loss spectroscopy (EELS), and were identified to
be single crystals of α-Fe. 相似文献
8.
Koichiro Hirano Masafumi Fukuda Mikio Takano Yoshio Yamazaki Toshiya Muto Sakae Araki Nobuhiro Terunuma Masao Kuriki Mitsuo Akemoto Hitoshi Hayano Junji Urakawa 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2006,560(2):233-239
A multi-bunch photo-cathode RF gun system has been developed as an electron source for the production of intense quasi-monochromatic X-rays based on inverse Compton scattering. The desired multi-bunch beam is 100 bunches/pulse with a total charge of 500 nC and a bunch spacing of 2.8 ns. We modified the gun cavity of a ‘BNL-type IV’ RF gun to allow a CsTe cathode plug in the end plate. The system uses a four-dipole chicane beam line to allow the injection of laser light normal to the cathode surface. We compensate the gun cavity beam loading caused by the high-intensity multi-bunch electron beam by injecting the laser pulse before RF power has filled the cavity. We have achieved a total intensity of 220 nC in 100 bunches with a bunch-to-bunch energy spread under 1.3% (peak-to-peak). This paper concentrates on experiments to generate the high-intensity multi-bunch beam with compensation of the bunch-to-bunch energy spread due to heavy beam loading. 相似文献
9.
10.
Yoshihiko Hangai Hiroaki Yoshida Nobuhiro Yoshikawa 《Metallurgical and Materials Transactions A》2012,43(3):802-805
A new friction powder compaction (FPC) process by the sintering and dissolution process (SDP) route for fabricating open-cell
aluminum (Al) foam, which requires no external heat sources, was developed. Foams with porosities of 74 and 83 pct were successfully
fabricated and their compressive responses were investigated. The sintered mixture during the removal process was observed
nondestructively by X-ray computed tomography (CT) to reveal the progress of the removal of soluble particles and to confirm
that they were completely dissolved. 相似文献