全文获取类型
收费全文 | 181篇 |
免费 | 8篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 20篇 |
综合类 | 1篇 |
化学工业 | 49篇 |
金属工艺 | 15篇 |
机械仪表 | 10篇 |
建筑科学 | 5篇 |
能源动力 | 9篇 |
轻工业 | 17篇 |
无线电 | 3篇 |
一般工业技术 | 28篇 |
冶金工业 | 11篇 |
原子能技术 | 6篇 |
自动化技术 | 22篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2019年 | 1篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 6篇 |
2015年 | 4篇 |
2014年 | 5篇 |
2013年 | 26篇 |
2012年 | 5篇 |
2011年 | 13篇 |
2010年 | 7篇 |
2009年 | 6篇 |
2008年 | 8篇 |
2007年 | 6篇 |
2006年 | 11篇 |
2005年 | 7篇 |
2004年 | 8篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 6篇 |
1997年 | 10篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1976年 | 2篇 |
排序方式: 共有196条查询结果,搜索用时 31 毫秒
41.
Quantitatively evaluating the fatigue strength of ductile iron (DI) with casting surfaces involves several complicated factors such as surface roughness, transition of microstructures from surface to interior, several types of defects and residual stresses. Tension–compression fatigue tests have been performed using DI having casting surfaces composed of a ferritic structure, a ferrite‐pearlitic structure and a pearlitic structure. Residual stresses were relieved by annealing in order to separately evaluate each factor. The parameter model was applied for quantitative evaluation of fatigue strength. Surface roughness was considered to be mechanically equivalent to a defect, and the effective defect size due to the interaction between the surface roughness and a defect was defined. The present study proposes a method of evaluating the maximum defect size using statistics of extremes and the lower bound of the scatter of fatigue strength, for practical design. 相似文献
42.
Atsuko SHINOHARA Takehisa MATSUKAWA Momoko CHIBA Toshio KUMASAKA Jun KOBAYASHI Kenji TAKAMORI Shozo ICHINOSE Kazuhito YOKOYAMA 《中国稀土学报(英文版)》2010,(Z1):507-509
Distribution of Sm and Ce in mice was investigated after inhalation exposure to their oxide particles of 5 μm diameter and 15 mg/m3.Sm and Ce were mainly distributed in lung,their concentrations decreased with passing time,and their concentrations in lung were correlated with exposure periods.Concentrations of Ce were lower than that of Sm in each point.Sm was also distributed in the other organs and bone but Ce was scarcely detected.These results suggest that the behaviors of Sm and Ce inhaled were different,although their chemical properties are similar. 相似文献
43.
由于对环境的关注和废料的处理问题,近些年对工业废料进行了积极的回收.回收废料作为混合材被广泛应用在GRC混凝土中.本文对使用了工业废料混合材的GRC的基本物理性能和耐久性所进行了研究.我们的结论是:粉煤灰、矿渣和硅灰的使用可以提高GRC的耐久性.在这些结论的基础上,提出将耐久性好的GRC配合比与回收废料结合在一起.经加速老化试样的抗折强度相当于暴露在日本室外10年时间的试件的强度,高于最初的强度,等于传统GRC的强度.由于火山灰反应消耗了基体中的Ca(OH)2,分别通过热分析和X射线衍射分析,在加速老化的含有矿渣和硅灰的砂浆中没有发现Ca(OH)2. 相似文献
44.
Kohei TANAKA L Junchang Yoshitsugu KOBAYASHI Darla K. ZELENITSKY XU Li JIA Songhai QIN Shuang TANG Min'an 《Canadian Metallurgical Quarterly》2011,85(1)
Here, we examine 145 dinosaur eggshells from a new fossil locality in the Qiupa Formation (Upper Cretaceous) of the Luanchuan area in western Henan Province, China. The eggshells display elongatoolithid macro- and microstructures, including ridges and nodes on the outer surface, two ultrastrncturai layers, and an undulatory boundary between the mammiilary and continuous layers.A phylogenic analysis shows that the Luanchuan eggshells belong to the ooclade Eiongatoolithidae.Within Elongatoolithidae, the thickness ratio of the mammillary layer to the entire eggshell, and the porosity of the Luanchuan eggshells are comparable to the oogenera Macroolithus and Elongatoolithus. There is no direct evidence for the taxonomic identity of the Luanchuan eggshells;however, they were likely laid by oviraptorids based on their phyiogenetic position and their similarities with known oviraptorid eggs. 相似文献
45.
Identification of Cross-linking Site(s) of Myosin Heavy Chains in Oxidatively Stressed Chicken Myofibrils 总被引:3,自引:0,他引:3
ABSTRACT: The cross-linking site(s) of myosin heavy chains (MHC) in chicken myofibrils exposed to non-enzymatic, hydroxyl radical-generation oxidizing systems (HRGS) was investigated by means of chymotryptic digestion and subsequent electrophoresis. Oxidation of the chymotryptic digests resulted in cross-linking of the rod or light meromyosin (LMM) segment of MHC mostly via disulfide bonds, while subfragment-1 (S-1) or heavy meromyosin (HMM) was not affected. A mixture of cross-linked rod or LMM and uncross-linked S-1 or HMM was also produced when myofibrils were 1st oxidized and then digested with chymotrypsin, confirming that cross-linking of myosin in HRGS-oxidized myofibrils occurred initially in the LMM portion of the myosin rod. 相似文献
46.
KOJI AIZAWA SOTA KOBAYASHI HIROSHI ISHIWARA KAZUYUKI SUZUKI KAZUMI KATO 《Integrated ferroelectrics》2013,141(1):169-174
Fabrication and characterization of metal-ferroelectric-insulator-semiconductor field-effect-transistors (MFIS FETs) using (Y,Yb)MnO3/Y2O3/Si structures were introduced for the first time. P-channel MFIS FETs were fabricated on n-type Si(111) substrates, in which an Y0.5Yb0.5MnO3(200 nm)/Y2O3(25 nm) structure was used as gate insulator. The Y0.5Yb0.5MnO3 and Y2O3 films were prepared by chemical solution deposition. A fabricated MFIS FETs showed the hysteresis loop due to spontaneous polarization in the ID-VGS characteristic, in which the memory window was about 0.9V when the applied gate voltage was swept between 8 V and ?8 V. Especially, the alternative drain current was retained after applying a single voltage pulse with a magnitude of +9 V or ?9 V. 相似文献
47.
Shuzo KOBAYASHI Mitsuko MIYAMOTO Hajime KURUMATANI Machiko OKA Kyoko MAESATO Tsutomu MANO Ryota IKEE Hidekazu MORIYA Takayasu OHTAKE 《Hemodialysis international. International Symposium on Home Hemodialysis》2009,13(3):286-292
Little data are available on the role of blood rheology in atherosclerosis in hemodialysis (HD) patients. This study sought to assess the relationship between leukocytes conjugated with platelets (leukocyte aggregates [LA]) and atherosclerosis in patients with HD. The present study included 118 patients on HD. As surrogate markers of atherosclerosis, aortic stiffness measured by brachial-ankle pulse wave velocity, and carotid intima-media thickness (IMT) were measured. As an assessment of LA, a method, microchannel array flow analyzer, which makes it possible to directly observe the flow of blood cell elements through the microchannel, was used. We measured a number of LA during 50 μL flow of whole blood through microchannels. In 12 age-matched healthy individuals, a number of LA during 50 μL flow of whole blood was 25.7±5.4, whereas in HD patients it was significantly increased up to 48.2±16.4 (P<0.001). Flow cytometry demonstrated that LA were predominantly monocytes. Leukocyte aggregates were positively associated with plasma levels of fibrinogen (P<0.01), or serum high-sensitive C-reactive protein (P<0.01). Moreover, LA had highly significant associations with brachial-ankle pulse wave velocity (P<0.001) and IMT (P<0.001). In conclusion, we demonstrated hemorheologically that monocyte-platelet conjugates play an important role in aortic stiffness and IMT in HD patients. 相似文献
48.
49.
RYO ISHIDA YASUSHI YAMANO SHINICHI KOBAYASHI ATSUSHI KOJIMA MASAYA HANADA YOSHIO SAITO 《Electrical Engineering in Japan》2016,196(3):3-12
Dark current based on field emission current is considered to be a factor causing the vacuum electrical breakdown between multiaperture acceleration grids in the JT‐60 negative ion source. In this paper, we focus on field enhancement factor, which is a key parameter of field emission from the electrode. Vacuum breakdown testing for small‐sized electrodes simulating the multiaperture acceleration grids of the negative ion source was performed. We found the field enhancement factor and breakdown field for multiaperture electrodes, and we investigated the dependence of each parameter on the number of apertures. The results revealed that an increase in the average field enhancement factor after the end of conditioning resulting from an increase in the number of apertures led to a decrease in the dielectric strength of the multiaperture electrodes. 相似文献
50.
KIYOSHI NAGATA TOMOYUKI OHYAMA HIROAKI SATO TOMOAKI ITO ATSUSHI ETO TAKAYUKI KOBAYASHI 《Electrical Engineering in Japan》2016,196(4):32-39
We developed the 550‐kV disconnectors that strengthened earthquake proofing by the addition of the damper unit and weight reduction of conductive part based on the damage of the 550‐kV disconnectors by the Great East Japan earthquake (March 11, 2011) and inspected the earthquake proofing performance by shake table test. In shake table test, we performed the test by the artificial seismic wave that varied in phase characteristic in addition to the test by resonance method. And, in a high‐level earthquake area, we analyzed it about the influence that a phase characteristic of the artificial seismic wave gave to stress to occur in disconnectors. As a result, it is thought that the stress to occur in disconnectors is decided by a primary natural frequency basically because a bending strain to occur to the disconnectors in the time when the resonance frequency ingredient becomes the big acceleration response value grows big. But, on a particular phase condition, it was confirmed that the bending strain to occur in disconnectors might grow big conspicuously. As for this, the possibility is thought about by influence of higher natural frequency doing superposition. 相似文献