全文获取类型
收费全文 | 919篇 |
免费 | 5篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 3篇 |
综合类 | 1篇 |
化学工业 | 67篇 |
金属工艺 | 9篇 |
机械仪表 | 7篇 |
建筑科学 | 16篇 |
矿业工程 | 10篇 |
能源动力 | 34篇 |
轻工业 | 17篇 |
石油天然气 | 1篇 |
无线电 | 13篇 |
一般工业技术 | 37篇 |
冶金工业 | 676篇 |
原子能技术 | 6篇 |
自动化技术 | 28篇 |
出版年
2020年 | 4篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2015年 | 9篇 |
2014年 | 6篇 |
2013年 | 13篇 |
2012年 | 14篇 |
2011年 | 11篇 |
2010年 | 7篇 |
2009年 | 9篇 |
2008年 | 9篇 |
2007年 | 10篇 |
2006年 | 10篇 |
2005年 | 11篇 |
2003年 | 7篇 |
2002年 | 9篇 |
2001年 | 4篇 |
2000年 | 7篇 |
1999年 | 25篇 |
1998年 | 194篇 |
1997年 | 101篇 |
1996年 | 90篇 |
1995年 | 39篇 |
1994年 | 41篇 |
1993年 | 50篇 |
1992年 | 12篇 |
1991年 | 11篇 |
1990年 | 11篇 |
1989年 | 11篇 |
1988年 | 12篇 |
1987年 | 11篇 |
1986年 | 5篇 |
1985年 | 9篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1982年 | 8篇 |
1981年 | 10篇 |
1980年 | 13篇 |
1979年 | 5篇 |
1978年 | 4篇 |
1977年 | 21篇 |
1976年 | 31篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1972年 | 5篇 |
1971年 | 5篇 |
1970年 | 6篇 |
1959年 | 2篇 |
1946年 | 2篇 |
排序方式: 共有925条查询结果,搜索用时 15 毫秒
31.
The formation of single textured low density polyethylene by unidirectional rolling has been investigated. It was found to be associated with the shear of the sample during annealing, which is a reversal of the shear imparted by the rolling process. Single texture could be produced from double texture by compressing it obliquely in such a way as to simulate this shear. It is concluded that the material probably contains another component besides the single orientation of lamellae which would need to be taken into account when using it as a model for the study of lamellar properties. 相似文献
32.
33.
J. G. C. Pope 《JOM Journal of the Minerals, Metals and Materials Society》1964,16(6):520-521
The growing need for a means of rapidly melting scrap in steelmaking practice is briefly discussed. The Shell Toroidal burner designed for melting such cold charges is described, and its application to open-hearth furnaces and Fuel-Oxygen-Scrap (FOS) furnaces is discussed. 相似文献
34.
When equilibration with a gas phase containing CO-CO2 was used to establish the oxygen activity of BaTiO3 at 800°C, a considerable solubility of the second component of the gas mixture (namely carbon) was thermogravimetrically measured. The substantial solubility of this dopant is offered as a possible explanation of the anomalous behavior in the electrical conductivity at low oxygen pressures which has been reported. The results have been interpreted in terms of a defect model proposing that the electrical compensation of the interstitial carbon occurs by a “filling” of the oxygen vacancies and an increase in the number of conduction electrons. 相似文献
35.
Pope Benjamin; Blass Thomas; Cheek Judith; Siegman Aron W.; Bradford Norman H. 《Canadian Metallurgical Quarterly》1971,36(1):152
Attempted to replicate earlier findings by B. Pope and A. W. Siegman (see PA, Vol. 39:13386, and Vol. 40:509) that there is an inverse relationship between interviewer specificity and both interviewee productivity and uncertainty, through the use of more naturalistic interviewers. 24 18-40 yr. old psychiatric inpatients were interviewed 3 times in a low specificity, high specificity, and an uncontrolled interview. Previous findings were supported. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
36.
Thyroid carcinoma after high-dose external radiotherapy for Hodgkin's disease: report of three cases
IR McDougall CN Coleman JS Burke W Saunders HS Kaplan 《Canadian Metallurgical Quarterly》1980,45(8):2056-2060
Three patients (two female and one male), who had received mantle irradiation for Hodgkin's disease eight, ten, and twelve years previously, developed papillary thyroid carcinoma. The radiation doses to the necks overlying the site of thyroid cancers were 3000, 4000, and 4100 rads, respectively. It has been stated that there is no risk of developing thyroid cancer with such high doses of external irradiation but apparently this complication will be encountered in a small number of patients. 相似文献
37.
38.
39.
Temper embrittlement of Ni-Cr Steels by phosphorus 总被引:1,自引:0,他引:1
R. A. Mulford C. J. Mcmahon D. P. Pope H. C. Feng 《Metallurgical and Materials Transactions A》1976,7(7):1183-1195
Temper embrittlement in 3.5 pct Ni, 1.7 pct Cr steels doped with P and isothermally aged at several temperatures was studied
by measurements of ductile-to-brittle transition temperature and hardness, which were correlated with observations of the
intergranular fracture surfaces by Auger electron spectroscopy and scanning electron fractography. It is shown that if all
other factors remain constant, the effect of a small change in the matrix hardness can be very large; “overaging” (a maximum
in embrittlement with respect to aging time) was found to result from softening rather than from a reversal of segregation
of P. Nickel was found to be segregated at the grain boundaries, and both Ni and Cr appear to enhance the amount of segregated
P. The major role of Cr was found to be its effect of increasing matrix hardness (by enhancing hardenability and resistance
to softening during tempering), resulting in an increased susceptibility to temper embrittlement. The effect of variations
in the roughness of grain boundary topography appears to be small. It is shown that the segregation of P to grain boundaries
can be accounted for by diffusion from the matrix and is consistent with the hypothesis of equilibrium (Gibbsian) segregation.
The results are in qualitative agreement with the thermo-dynamic theory of Guttmann.
Formerly a Research Fellow at the Department of Materials Science, University of Pennsylvania, Philadelphia, PA 19174. 相似文献
40.
Z. Wang V.N. Daggupati G. Marin K. Pope Y. Xiong E. Secnik G.F. Naterer K.S. Gabriel 《International Journal of Hydrogen Energy》2012
The thermochemical copper–chlorine (Cu–Cl) cycle is a promising technology that can utilize various energy sources such as nuclear and solar energy to produce hydrogen with minimal or no emissions of greenhouse gases. Past investigations have primarily focused on the design and testing of individual unit operations of the Cu–Cl cycle. This paper investigates the chemical streams flowing through each individual process from the aspect of system integration. The interactions between each of the two immediate upstream and downstream processes are examined. Considering the integration of electrolytic hydrogen production and cupric chloride hydrolysis steps, it is evident that an intermediate step to concentrate CuCl2 and reduce HCl composition is required. Spray drying and crystallization, serving as the intermediate steps, are examined from the aspects of energy requirements and viability of engineering. Regarding the integration of the hydrolysis and oxygen production steps, thermodynamic and XRD analysis results are presented to study the mutual impacts of these two steps on each other. Within the hydrolysis reactor, high conversion of CuCl2 to Cu2OCl2 is preferable for the integration because it reduces the release of chlorine gas during the oxygen production. Considering the integration of the oxygen production step and electrolysis of CuCl, pulverization is needed for the solidified CuCl. The recovery of CuCl vapour entrained in oxygen gas requires further research. Residual CuCl2 introduced from the hydrolysis step into the oxygen production step may be further entrained by CuCl into the electrolytic hydrogen production cell. Additionally, thermal energy integration patterns are briefly discussed while integrating the various chemical streams of the Cu–Cl cycle. Steam generated from the heat recovery of cuprous chloride can be introduced into the hydrolysis reactor to serve as a reactant. 相似文献