全文获取类型
收费全文 | 527篇 |
免费 | 23篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 56篇 |
综合类 | 2篇 |
化学工业 | 176篇 |
金属工艺 | 12篇 |
机械仪表 | 27篇 |
建筑科学 | 12篇 |
能源动力 | 16篇 |
轻工业 | 36篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 43篇 |
一般工业技术 | 86篇 |
冶金工业 | 18篇 |
原子能技术 | 18篇 |
自动化技术 | 48篇 |
出版年
2023年 | 7篇 |
2022年 | 8篇 |
2021年 | 17篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 14篇 |
2017年 | 7篇 |
2016年 | 10篇 |
2015年 | 15篇 |
2014年 | 21篇 |
2013年 | 37篇 |
2012年 | 22篇 |
2011年 | 40篇 |
2010年 | 21篇 |
2009年 | 15篇 |
2008年 | 26篇 |
2007年 | 17篇 |
2006年 | 14篇 |
2005年 | 19篇 |
2004年 | 17篇 |
2003年 | 17篇 |
2002年 | 16篇 |
2001年 | 15篇 |
2000年 | 9篇 |
1999年 | 10篇 |
1998年 | 11篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1994年 | 7篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1989年 | 6篇 |
1987年 | 5篇 |
1986年 | 9篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 5篇 |
1976年 | 6篇 |
1975年 | 4篇 |
1974年 | 5篇 |
1972年 | 5篇 |
1971年 | 3篇 |
1970年 | 5篇 |
1969年 | 3篇 |
排序方式: 共有552条查询结果,搜索用时 15 毫秒
1.
Multimedia Tools and Applications - 相似文献
2.
Power devices with high capability have been developed. 8‐kV/3.5‐kA‐class light‐triggered thyristors have the highest capability among power devices. These devices are used in the Kii Channel HVDC transmission system in Japan. In this paper, we report the extracted problems of conventional testing methods of 8‐kV/3.5‐kA‐class light‐triggered thyristors among manufacturers, and the proposed unified testing methods on the basis of element characteristics and operating conditions in the Kii Channel HVDC system. Furthermore, we propose a figure of merit for power devices for the practical use, and try to extract elements used at the Kii Channel HVDC system with small margins and low withstand capabilities. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 140(3): 61–70, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10024 相似文献
3.
Namsin Park Takeyuki Shiraishi Kazuyoshi Kamisugi Yoshitaka Hara Keita Iizuka Takashi Kado Shuzi Hayase 《Journal of Applied Electrochemistry》2008,38(3):371-375
A direct ethanol fuel cell (DEFC), which is less prone to ethanol crossover, is reported. The cell consists of PtRu/C catalyst as the anode, Nafion® 117 membrane, and Ni–Co–Fe (NCF) composite catalyst as the cathode. The NCF catalyst was synthesized by mixing Ni, Co, and Fe complexes into a polymer matrix (melamine-formaldehyde resins), followed by heating the mixture at 800 °C under inert atmosphere. TEM and EDX experiments suggest that the NCF catalyst has alloy structures of Ni, Co and Fe. The catalytic activity of the NCF catalyst for the oxygen reduction reaction (ORR) was compared with that of commercially available Pt/C (CAP) catalyst at different ethanol concentrations. The decrease in open circuit voltage (Voc) of the DEFC equipped with the NCF catalysts was less than that of CAP catalyst at higher ethanol concentrations. The NCF catalyst was less prone to ethanol oxidation at cathode even when ethanol crossover occurred through the Nafion®117 film, which prevents voltage drop at the cathode. However, the CAP catalyst did oxidize ethanol at the cathode and caused a decrease in voltage at higher ethanol concentrations. 相似文献
4.
The activities of FexO in CaO + CaF2 + SiO2 + FexO quaternary slags were measured by means of solid-oxide galvanic cell. The FexO activities in the slags are influenced by CaF2 as well as SiO2. At constant FexO mole fractions, e.g., , at low SiO2 mole fractions i.e., , the substitution of CaF2 for CaO has an effect of raising the FexO activity. At higher SiO2 mole fractions, e.g., , however, such an effect becomes insignificant. 相似文献
5.
Hitomi Natomi Toshihito Saitoh Kentaro Sugano Masao Iwamori Masahisa Fukayama Yoshitaka Nagai 《Lipids》1993,28(8):737-742
The composition of the glycosphingolipids of the human gastrointestinal tract was studied. The major neutral glycosphingolipids
were ceramide monohexosides (e.g., GalCer, GlcCer), LacCer, Gb3Cer, Gb4Cer and more polar ones with more than four sugars, whereas neither Gg3Cer nor Gg4Cer were present. The acidic glycosphingolipids consisted of sulfatides and gangliosides such as GM3, GM1, GD3 and GD1a. Also a large amount of sulfatides was found in the gastric mucosa and duodenum. The concentrations of sulfatides in the
fundic mucosa, antral mucosa and duodenum amounted to 416.0, 933.8 and 682.9 nmol/g of dry weight, respectively, exceeding
those in the gastric mucosa and kidney of other mammals. The major molecular species of the sulfatides were identified as
I3SO3-GalCer with hydroxylated longer-chain fatty acids based on the analyses by gas-liquid chromatography and negative ion fast-atom
bombardment mass spectrometry. In contrast, gangliosides in these regions showed a tendency to be lower than sulfatides, and
the molar ratios of sulfatides to gangliosides were about 2.0, whereas those in other parts were less than 0.5. A high content
of sulfatides in the gastric and duodenal mucosa, where mucosa is easily insulted by acid, pepsin and bile salts, may be closely
related to their roles in mucosal protection.
The nomenclature used for gangliosides and other glycosphingolipids follows the system of Svennerholm (Ref. 1) and the recommendation
of the IUPAC-IUB Commission (Ref. 2), respectively. 相似文献
6.
In photo-induced graft copolymerization of methyl methacrylate onto cellulose, the effect of metallic ions as sensitizer was investigated. Some metallic ions were effective in their adsorbed states and accelerated the formation of grafts in the order Fe2+ > Ag+ > Fe3+. However, Cu2+ acted negatively, and little effect was observed for Co2+, Ni2+, Mn2+, Zn2+, and Cr3+. In the systems in which aqueous metallic salt solutions were added, the formation of grafts was generally depressed, but Fe3+ was an exception. The effect of metallic ions on the scission reaction of cellulose main chains did not necessarily agree with the effect on the formation of grafts. This is attributed to the varied interaction between cellulose and the different active species produced by irradiation, depending on the type of metallic ions used. 相似文献
7.
The effect of sodium thiosulfate on the graft copolymerization of methyl methacrylate to cellulose in the hydrogen peroxide initiator system was investigated. The addition of sodium thiosulfate in general was effective for decreasing the per cent grafting and the average molecular weight of grafts and increasing the formation of homopolymer, and the effects became pronounced with increasing hydrogen peroxide concentration. Moreover, the addition of sodium thiosulfate slightly suppressed the formation of grafts at a hydrogen peroxide concentration of 3 mmole/l., but greatly promoted it at 20 mmole/l. Traces of metallic ions present in cellulose could not be eliminated sufficiently by treatment with 3N hydrochloric acid. Such ions were found to interact with hydrogen peroxide and thus participate directly in the initiation and termination of the polymerization reaction. EDTA, the chelating agent, was highly effective for suppressing such participation of metallic ions. In the hydrogen peroxide initiator system applied to the EDTA-treated samples, sodium thiosulfate caused an effective initiation of graft formation. 相似文献
8.
To develop insulating materials with a high thermally conductive anisotropy, planarly aligned mesogenic epoxy (ME) resin film was fabricated by uniaxial coating on a hydrophobic polyethylene terephthalate substrate. Grazing incidence small-angle X-ray scattering (GISAXS) and transmission SAXS measurements exhibited that the films spontaneously formed uniaxially aligned monodomain-like smectic structures by curing on the hydrophobic substrate. Then, an in- and out-of-plane thermal conductivity of 10 and 0.048 W m−1 K−1 and outstanding thermal conductivity anisotropy of 208 have been confirmed, respectively. The ME resin films with high thermal conductivity can be applied as insulating materials for multiple-layer electrical and electronic devices. 相似文献
9.
Jiangyan Zhang Tielong Shen Junichi Kako Shozo Yoshida 《International Journal of Control, Automation and Systems》2009,7(4):659-667
In this paper, the speed control problem of internal combustion engines is investigated based on mean-value engine models.
The dynamics of internal combustion engines is a complicated nonlinear system, and usually, it is difficult to know the exact
values of the physical parameters. First, a Lyapunov-based design method is shown without requiring the full information of
the physical parameters. Then, to improve transient performance, the design method is extended to several cases under different
operation conditions. Numerical simulation results are presented for comparing the proposed design methods. Finally, experiments
are conducted on an engine test bench and the results demonstrate the validity of the proposed design methods.
Recommended by Editorial Board member Myotaeg Lim under the direction of Editor Hyun Seok Yang. The authors are grateful to
Kai Zheng for his assistance of the model identification experiments.
Jiangyan Zhang received the B.E. and M.E. degrees in Electrical Engineering, Yanshan University, China, in 2005 and 2008, respectively.
Now, she is a Ph.D. candidate with the Department of Engineering and Applied Sciences, Sophia University, Tokyo, Japan. Her
current research interests include nonlinear system control theory and applications to powertrain system control.
Tielong Shen received the Ph.D. degree in Mechanical Engineering from Sophia University, Tokyo, Japan, March, 1992. From April 1992, he
has been a faculty member of the Chair of Control Engineering in Department of Mechanical Engineering, Sophia University,
where he currently serves as professor of the Department of Engineering and Applied Science. His research interests include
control theory and application in mechanical systems, power systems, and automotive powertrain. Currently, he is an Associate
Editor for the IEEE Control System Society Conference Editorial Board, and is serving as Associate Editor of Journal of Control
Theory and Applications, and the Regional Editor Asia-Pacific for International Journal of Modeling, Identification and Control
etc.
Junichi Kako received the B.E. degree from Nagoya Institute of Technology, Nagoya, Japan. He joined Toyota Motor Corporation, Tokyo, Japan
in 1989. He worked on various aspects of automotive powertrain control. From 1989 to 1994, he took part in the team for the
development of Laboratory Automation (LA) system, Engineering Office Automation (EOD) system, and embedded system of powertrain
control. During 1995–2001, he focused on the engine control systems in Powertrain Management Engineering Division. In 2002,
he was with Future Project Division in which he was responsible for the R&D of model-based engine control system. Currently,
he is developing engine control systems in the Powertrain Management Engineering Division, Toyota Motor Corporation.
Shozo Yoshida received the M.S. degree in Engineering from Kyoto University, Kyoto, Japan. He joined Toyota Motor Corporation, Tokyo, Japan
in 2000. From 2000 to 2004, he was with Future Project Division and worked on physical combustion modeling for Model-based
Control Development. Since 2005, he has been with the Powertrain Management Engineering Division Toyota Motor Corporation,
and is a member of the R&D of Model-based Engine Calibration. 相似文献
10.
The effect of small dose of topiroxostat on serum uric acid in patients receiving hemodialysis 下载免费PDF全文
Yume Nagaoka Yoshiko Tanaka Hiroshi Yoshimoto Rie Suzuki Kakei Ryu Mio Ueda Minako Akiyama Miho Nagai Yoshitaka Miyaoka Eiichiro Kanda Shinnichi Iwai Michio Nagaoka Yoshihiko Kanno 《Hemodialysis international. International Symposium on Home Hemodialysis》2018,22(3):388-393
Introduction : Topiroxostat, a recently developed xanthine oxidase inhibitor, is expected to have fewer adverse effects than allopurinol because it has different mechanism of action from alloprinol. However, its dosage, usage and safety have not been established in patients with impaired renal function or those undergoing dialysis at the development since no studies was conducted in these patients. Methods : Cross over clinical trial using 3 months of allopurinol and topiroxostat on 27 maintain Japanese HD patients were carried out. The effects on oxidative stress status of both drugs were also evaluated by measuring oxidation reduction potential. Findings : Twenty‐five of twenty‐seven patients completed study. The mean serum uric acid levels in the topiroxostat‐treated arm was significantly lower than it in the allopurinol‐treated arm time‐dependently (P < 0.0001). Corrected oxidative stress ratio defined as biological antioxidant potential/diacron reactive oxygen metabolites was significantly increased in topiroxostat‐arm (*P = 0.0035), but not in allopurinol‐arm (P = 0.1429). No significant difference was seen in diacron reactive oxygen metabolites, biological antioxidant potential, static oxidation‐reduction potential, and capacity oxidation‐reduction potential between pre and post treatment of both drugs. Discussion : It is suggested that a low dose of topiroxostat decreased serum uric acid sufficiently to maintain it below 7.0 mg/dL in patients receiving hemodialysis. 相似文献