全文获取类型
收费全文 | 1444篇 |
免费 | 30篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 120篇 |
化学工业 | 334篇 |
金属工艺 | 45篇 |
机械仪表 | 38篇 |
建筑科学 | 35篇 |
能源动力 | 32篇 |
轻工业 | 103篇 |
水利工程 | 5篇 |
石油天然气 | 1篇 |
无线电 | 114篇 |
一般工业技术 | 266篇 |
冶金工业 | 191篇 |
原子能技术 | 50篇 |
自动化技术 | 147篇 |
出版年
2023年 | 11篇 |
2022年 | 28篇 |
2021年 | 31篇 |
2020年 | 18篇 |
2019年 | 19篇 |
2018年 | 22篇 |
2017年 | 21篇 |
2016年 | 32篇 |
2015年 | 17篇 |
2014年 | 31篇 |
2013年 | 75篇 |
2012年 | 56篇 |
2011年 | 80篇 |
2010年 | 59篇 |
2009年 | 42篇 |
2008年 | 67篇 |
2007年 | 60篇 |
2006年 | 44篇 |
2005年 | 54篇 |
2004年 | 42篇 |
2003年 | 53篇 |
2002年 | 36篇 |
2001年 | 30篇 |
2000年 | 29篇 |
1999年 | 25篇 |
1998年 | 74篇 |
1997年 | 67篇 |
1996年 | 38篇 |
1995年 | 37篇 |
1994年 | 35篇 |
1993年 | 34篇 |
1992年 | 15篇 |
1991年 | 18篇 |
1990年 | 19篇 |
1989年 | 15篇 |
1988年 | 14篇 |
1987年 | 13篇 |
1986年 | 15篇 |
1985年 | 9篇 |
1984年 | 18篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 12篇 |
1980年 | 11篇 |
1979年 | 11篇 |
1978年 | 5篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1973年 | 7篇 |
1971年 | 2篇 |
排序方式: 共有1481条查询结果,搜索用时 15 毫秒
51.
Jun Koyanagi Hideo Nagayama Satoru Yoneyama Takahira Aoki 《Mechanics of Time-Dependent Materials》2016,20(2):219-232
This paper presents the time dependence of the mesoscopic strain of a triaxial woven carbon-fiber-reinforced polymer under creep loading measured using digital image correlation (DIC). Two types of DIC techniques were employed for the measurement: conventional subset DIC and mesh DIC. Static tensile and creep tests were carried out, and the time dependence of the mesoscopic strain distribution was investigated by applying these techniques. The ultimate failure of this material is dominated by inter-bundle decohesion caused by relative rigid rotation and relating shear stress. Therefore, these were focused on in the present study. During the creep tests, the fiber directional strain, shear strain, and rotation were monitored using the DIC, and the mechanism for the increase in the specimen’s macro-strain over time was investigated based on the results obtained by the DIC measurement. 相似文献
52.
Satoru Okamoto 《机械工程与自动化:英文版》2014,(10):770-780
The tendency for air column resonance generation in structures with a constant volume behind a tube array like that of an exhaust gas economizer has been reported, but many points remain unclear with respect to the mechanism and conditions that generate acoustical resonance. When acoustical resonance is generated, in reality, prevention and suppression measures are implemented by inserting a baffle plate into the ducts through a process of trial and error. The purpose of this study is to clarify the mechanism of generation of acoustical resonance, and to establish an appropriate measure to prevent such resonance. Noise generated in an exhaust gas economizer was correlated with the flow inside the tube array and experimentally analyzed, and the mechanism for resonance generation was considered. In addition, the effectiveness of a baffle plate positioned in order to prevent resonance was investigated. We have successfully employed a single baffle plate to suppress resonance. 相似文献
53.
54.
Yasuhiro Yogo Michiaki Kamiyama Takamichi Iwata Noritoshi Iwata Takashi Ishikawa 《Metallurgical and Materials Transactions A》2012,43(3):893-899
In this article, the isothermal flow stress in supercooled austenite was measured for a high hardenability steel. Supercooled
austenite forms at the nonequilibrium phase and changes into other phases within a short time. It was confirmed that conventional
tensile tests, which require maintaining a constant temperature before stretching, cannot accurately measure the flow stress
in supercooled austenite. Therefore, a new tensile test named “the continuous cooling tensile test” was developed. In this
test, stretching is conducted during continuous cooling. In the continuous cooling tensile test, the flow stress between 673 K
and 973 K (400 °C and 700 °C) was measured. Microscopic observations of the continuous cooling test results verified that
the microstructures were supercooled austenite. 相似文献
55.
Boron and nitrogen-incorporated graphene thin films were grown on polycrystalline Ni substrates by thermal chemical vapor deposition using separate boron- and nitrogen-containing feedstocks. Boron and nitrogen atoms were incorporated in the film in almost equal amounts and the total content reached ∼28%. The film predominantly consisted of separate graphene and boron nitride domains. Carrier concentration in the graphene domains was estimated to be about 1 × 10−3 e/atom (3.8 × 1012 cm−2) from G band shift in Raman spectra. 相似文献
56.
Shizue Furukawa Mikimasa Iwata Kazuo Adachi Tadashi Amakawa 《Electrical Engineering in Japan》2010,170(2):46-52
We investigated by numerical analysis the dependence of vaporization behavior of aluminum particles injected into transferred type arc plasma on injection conditions in synthesis of aluminum nitride ultra fine particles. On the basis of calculation results, we chose one proper injection condition where aluminum particles vaporized more. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(2): 46–52, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20852 相似文献
57.
Satoshi?KameokaEmail author Satoru?Wakabayashi Eiji?Abe An?Pang?Tsai 《Catalysis Letters》2016,146(7):1309-1316
58.
The mechanical force to polymeric materials in vacuum at 77 K produces mechano radicals, mechano anions and mechano cations due to homogeneous and heterogeneous scissions of the covalent bonds comprising polymer main chain. The ionic degree of the covalent bond was estimated by calculating the “absolute ΔMulliken atomic charge,” which was defined as the difference between the Mulliken atomic charges of the two adjacent atoms comprising the covalent bond of the polymer main chain. The ionic yield of the covalent bond increased with increasing the absolute ΔMulliken atomic charge. The empirical formula for the ionic yield was obtained with the absolute ΔMulliken atomic charge, and indicates that the ionic yield could be estimated from its chemical structure. 相似文献
59.
Junya Hanaguri Harumasa Yokota Akifumi Kushiyama Sakura Kushiyama Masahisa Watanabe Satoru Yamagami Taiji Nagaoka 《International journal of molecular sciences》2022,23(3)
We investigated the effect of tofogliflozin, a sodium-dependent glucose cotransporter 2 inhibitor (SGLT2i), on retinal blood flow dysregulation, neural retinal dysfunction, and the impaired neurovascular coupling in type 2 diabetic mice. Tofogliflozin was added to mouse chow to deliver 5 mg/kg/day and 6-week-old mice were fed for 8 weeks. The longitudinal changes in the retinal neuronal function and blood flow responses to systemic hyperoxia and flicker stimulation were evaluated every 2 weeks in diabetic db/db mice that received tofogliflozin (n =6) or placebo (n = 6) from 8 to 14 weeks of age. We also evaluated glial activation and vascular endothelial growth factor (VEGF) expression by immunofluorescence. Tofogliflozin treatment caused a sustained decrease in blood glucose in db/db mice from 8 weeks of the treatment. In tofogliflozin-treated db/db mice, both responses improved from 8 to 14 weeks of age, compared with vehicle-treated diabetic mice. Subsequently, the electroretinography implicit time for the oscillatory potential was significantly improved in SGLT2i-treated db/db mice. The systemic tofogliflozin treatment prevented the activation of glial fibrillary acidic protein and VEGF protein expression, as detected by immunofluorescence. Our results suggest that glycemic control with tofogliflozin significantly improved the impaired retinal neurovascular coupling in type 2 diabetic mice with the inhibition of retinal glial activation. 相似文献
60.
Based on the subsite structure of an α-amylase from Bacillus subtilis, production of glucose from a substrate maltohexaose in the amylase-catalyzed reaction was theoretically predicted as a function of time. The theoretical time course was found consistent with the experimental results, which were obtained by the determination of a product glucose with a commercial assay-kit. Hence, glucose, product from a substrate maltohexaose, will be a useful probe for the amylase-catalyzed reaction. 相似文献