全文获取类型
收费全文 | 308篇 |
免费 | 12篇 |
专业分类
电工技术 | 13篇 |
化学工业 | 62篇 |
金属工艺 | 13篇 |
机械仪表 | 22篇 |
建筑科学 | 3篇 |
能源动力 | 9篇 |
轻工业 | 41篇 |
水利工程 | 1篇 |
石油天然气 | 2篇 |
无线电 | 22篇 |
一般工业技术 | 41篇 |
冶金工业 | 72篇 |
原子能技术 | 9篇 |
自动化技术 | 10篇 |
出版年
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 6篇 |
2014年 | 7篇 |
2013年 | 8篇 |
2012年 | 13篇 |
2011年 | 15篇 |
2010年 | 19篇 |
2009年 | 11篇 |
2008年 | 12篇 |
2007年 | 10篇 |
2006年 | 9篇 |
2005年 | 12篇 |
2004年 | 9篇 |
2003年 | 9篇 |
2002年 | 10篇 |
2001年 | 8篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 20篇 |
1997年 | 23篇 |
1996年 | 10篇 |
1995年 | 7篇 |
1994年 | 8篇 |
1993年 | 5篇 |
1992年 | 7篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1980年 | 3篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1974年 | 1篇 |
1967年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有320条查询结果,搜索用时 15 毫秒
1.
Y Setsu K Oka Y Naoi R Nagayama T Moriya T Matsumoto Y Yatabe N Mori 《Canadian Metallurgical Quarterly》1997,193(3):219-22; discussion 223-4
A 49 year-old female had been suffering from primary myelofibrosis since February 1987 without receiving any treatment. In 1994, a breast mass was detected. Breast tumor biopsy revealed tubular carcinoma with intraductal components and multinucleated giant cells in the loose and myxoid stroma. The giant cells were thought to be megakaryocytes because both Factor VIII and platelet glycoprotein GP IIIa were detected in their cytoplasm. While additional mastectomy specimens and the axillary lymph nodes also revealed prominent myeloid metaplasia, there was no proliferation of the cancer cells. Granulocytic series stained for chloroacetate esterase and very few erythrocytic series were observed. This is the first case in which breast carcinoma and myeloid metaplasia coexisted in the same breast tumor. 相似文献
2.
Crystallization of potassium titanate from the amorphous phase 总被引:1,自引:0,他引:1
Tadashi Endo Hiroyuki Nagayama Tsugio Sato Masahiko Shimada 《Journal of Materials Science》1988,23(2):694-698
By using amorphous potassium titanates as the starting materials, a sintered body of K2Ti4O9 or K2Ti6O13 with porous and fibrous textures was prepared. K2Ti2O5 and a new phase, K6Ti4O11 were synthesized by the thermal reaction of KNO3 with TiO2 at 1000° C for 10 to 20 h. On leaching in water to expel excess of potassium ions, both phases became amorphous. After mixing and moulding these amorphous materials in the desired proportion, a sintered body containing fibrous crystals of K2Ti4O9 was readily fabricated by heating at 1000° C for 12 h. When 5 wt % B2O3 was added to the amorphous phases, single phase K2Ti6O13, with a fibrous texture grew well on heating at 1000° C for 12 h. Addition of PVA polymer to the amorphous phases was responsible for controlling the porosity of the sintered body, e.g. about 52% theoretical density at 20 wt% PVA polymer. The optimum conditions for preparing the amorphous phases were systematically examined and the effect of the chemical reaction environments, such as different crucible materials on the calcination of KNO3 and TiO2 were also discussed. 相似文献
3.
Cathodic polarization curves were measured for copper in cupric pyrophosphate solutions of different concentrations and temperatures. A rotating disc electrode was used to eliminate concentration polarization. For all solutions, two potential regions are distinguishable in the polarization curve; one is less negative than a critical potential Eb around ?0.75 V vs sce (Region I) and the other more negative than Eb (Region II). A weak adsorption of pyrophosphate ions and hence some inhibition of the electrodeposition of copper is expected for Region I but there is no adsorption in Region II. The exchange current density io for the copper deposition was obtained by extrapolating the Tafel relation observed in Region II to the rest potential corresponding to the equilibrium potential. The following reaction mechanisms are proposed to explain the dependence of io on the concentration of Cu(P2O7)6?2 and P2O4?7 ions. Apparent activation energies are estimated to be about 11 kcal/mol in both cases. 相似文献
4.
An imaging method was developed based on null ellipsometry with a white-light source. It is useful for visualizing the kinetics of fast surface phenomena on the nanometer scale. 相似文献
5.
Junko Hatori Yasumitsu Matsuo Masaru Komukae Seiichiro Ikehata 《Materials Chemistry and Physics》2006,100(2-3):520-523
We have carried out the optical observation, electrical conductivity and 205Tl NMR measurements, and subsequently investigated the origin of the large conductivity above ferroelastic phase transition temperature Tc (=661 K) on the basis of the domain structure and the crystal structure. Electrical conductivity exhibits the discontinuous increase around Tc with increasing temperature and becomes approximately 5 × 10−3 S m−1 above Tc. Moreover, from the 205Tl NMR measurements, it is found that mobile Tl ions exist above Tc. Furthermore, from the analysis of the domain structure based on the crystal structure in the low-temperature ferroelastic phase, it is also found that the anomalously large fluctuations of SeO4 tetrahedrons exist above Tc. It is deduced from these results that the high electrical conductivity above Tc is caused by the mobile Tl ions closely related to the anomalously large fluctuations of SeO4 tetrahedrons accompanied by the ferroelastic phase transition. 相似文献
6.
Hall Gordon C. Nagayama; Teten Andra L.; DeGarmo David S.; Sue Stanley; Stephens Kari A. 《Canadian Metallurgical Quarterly》2005,73(5):830
Explanatory models of sexual aggression were examined among mainland Asian American (n = 222), Hawaiian Asian American (n = 127), and European American men (n = 399). The Malamuth et al. (N. M. Malamuth, D. Linz, C. L. Heavey, G. Barnes, & M. Acker, 1995; N. M. Malamuth, R. J. Sockloskie, M. P. Koss, & J. S. Tanaka, 1991) confluence model of sexual aggression, which posits impersonal sex and hostile masculinity as paths to sexual aggression, was consistently supported. Culture-specific moderators of sexual aggression were also identified. Whereas loss of face was a protective factor against sexual aggression in the Asian American samples, it generally was not a protective factor among European Americans. These findings are not a function of actual or perceived minority status. An implication is that theoretical models may need to be augmented with cultural constructs for optimal application in certain ethnic group contexts. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
7.
Currently, the development of leading‐edge technology for recording and loading human motion on the basis of haptic information is required in the fields of manufacturing and human support. Human movement is an assembly of motion components. Since human movements should be supported by a robot in real time, it is necessary to integrate the motion components that were saved earlier. Once such motion integration is realized, future technology for use in daily human life can be developed. This paper proposes the integrated reproduction of the decomposed components of human motion by using a motion copying system. This system is the key technology for the realization of the acquisition, saving, and reproduction of real‐world haptic information. By using the proposed method, it is possible not only to achieve expert skill acquisition, skill transfer to robots, and power assist for each motion component, but also to open up new areas of applications. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 181(1): 28–35, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21263 相似文献
8.
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
9.
Extracellular α-amylases I and II, produced by a facultative thermophile Bacillus thermoamyloliquefaciens KP 1071 capable of growing at 30–66°C, were purified to homogeneity. α-Amylase I consisted of a single polypeptide with methionine residue at the NH2-terminus. α-Amylase II consisted of two equivalent polypeptides each comprising a methionine at the NH2-terminus. α-Amylase I hydrolyzed endotypically α-1,4-bonds in glycogen, amylopectin and β-limit dextrin, but not their α-1,6-bonds. α-Amylase II degraded amylopectin and β-limit dextrin in exo-fashion by cleaving preferentially α-maltose units from the non-reducing ends and hydrolyzing their α-1,6-branch points. α-Amylase II hydrolyzed maltotriose, phenyl-α-maltoside, α- and β-cyclodextrins and pullulan, whereas α-amylase I had no activity for all these sugars. α-Amylases I and II hydrolyzed maltotetraose, maltopentaose, α-limit dextrin and amylose, but they were inactive for maltose, isomaltose and panose. It was suggested that α-amylase I is the most thermostable type of hitherto known maltotriogenic endo-acting α-amylases, and α-amylase II is the first maltogenic exo-acting α-amylase able to split α-1,6-bonds in amylopectin. 相似文献
10.
The combustion characteristics of high burn rate azide polymer composite propellant were examined by using a chimney type strand burner, a Ø 80 mm × 140 mm small rocket motor and a L/D = 16 of Ø 70 mm heavy-wall rocket motor. The propellant, BAMO/NMMO copolymer was used as a fuel binder and AP as an oxidizer, burned approximately 29 mm/s at a pressure range of 7 MPa to 20 MPa with a plateau-mesa burning behavior. However, the pressure exponent rapidly increased at above the pressure of 20 MPa and was 0.52 between 20 MPa and 25 MPa. The low pressure exponent and high burn rate of the azide polymer propellant are suitable to the short burn time at the maximum expected operating pressure range of 15 MPa to 20 MPa. The high L/D heavywall rocket motor with volumeric mass fraction of 83% showed stable combustion without any pressure oscillation and severe erosive burning. The average burn rate in the high L/D motor was 10% larger than that estimated from the strand data. The theoretically calculated pressure-vs-time and thrust-vs-time curves were well consistent with the measured data. α = 20 and β = 180 for the Lenoir-Robillard equation were used to estimate the burn rate. 相似文献