全文获取类型
收费全文 | 1321篇 |
免费 | 53篇 |
国内免费 | 14篇 |
专业分类
电工技术 | 13篇 |
综合类 | 3篇 |
化学工业 | 289篇 |
金属工艺 | 65篇 |
机械仪表 | 45篇 |
建筑科学 | 26篇 |
矿业工程 | 2篇 |
能源动力 | 95篇 |
轻工业 | 75篇 |
水利工程 | 8篇 |
石油天然气 | 5篇 |
无线电 | 114篇 |
一般工业技术 | 318篇 |
冶金工业 | 175篇 |
原子能技术 | 21篇 |
自动化技术 | 134篇 |
出版年
2024年 | 6篇 |
2023年 | 34篇 |
2022年 | 51篇 |
2021年 | 59篇 |
2020年 | 60篇 |
2019年 | 51篇 |
2018年 | 70篇 |
2017年 | 70篇 |
2016年 | 70篇 |
2015年 | 33篇 |
2014年 | 59篇 |
2013年 | 109篇 |
2012年 | 49篇 |
2011年 | 84篇 |
2010年 | 63篇 |
2009年 | 55篇 |
2008年 | 50篇 |
2007年 | 49篇 |
2006年 | 28篇 |
2005年 | 26篇 |
2004年 | 19篇 |
2003年 | 23篇 |
2002年 | 13篇 |
2001年 | 18篇 |
2000年 | 14篇 |
1999年 | 13篇 |
1998年 | 21篇 |
1997年 | 25篇 |
1996年 | 17篇 |
1995年 | 18篇 |
1994年 | 8篇 |
1993年 | 9篇 |
1992年 | 10篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1987年 | 14篇 |
1986年 | 15篇 |
1985年 | 8篇 |
1984年 | 12篇 |
1983年 | 9篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 6篇 |
1978年 | 2篇 |
1976年 | 3篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 2篇 |
排序方式: 共有1388条查询结果,搜索用时 265 毫秒
91.
H. R. Kotadia N. Hari Babu H. Zhang S. Arumuganathar Z. Fan 《Metallurgical and Materials Transactions A》2011,42(4):1117-1126
The effect of the processing temperature on the microstructural and mechanical properties of Al-Si (hypoeutectic) alloy solidified
from intensively sheared liquid metal has been investigated systematically. Intensive shearing gives a significant refinement
in grain size and intermetallic particle size. It also is observed that the morphology of intermetallics, defect bands, and
microscopic defects in high-pressure die cast components are affected by intensive shearing the liquid metal. We attempt to
discuss the possible mechanism for these effects. 相似文献
92.
93.
T. Lolla J. Siefert S. S. Babu D. Gandy 《Science & Technology of Welding & Joining》2014,19(6):476-486
In recent years, several incidents of cracking and failures have been observed in Stellite (Stellite is a registered trademark of the Deloro-Stellite Corporation) hardfacing used in valves of modern high temperature combined cycle gas fired power plants. These hardfacing layers are applied as an overlay onto a steel substrate, such as CrMo steel (i.e. Grade 22, WC9) or creep strength enhanced ferritic steel (i.e. Grade 91, C12A). Cracking has been observed in valve components at the Stellite/steel interface and in the weld dilution zone formed between the steel and clad. Ultimately, disbonding or delamination of the weld hardfacing from the valve body occurs and has resulted in collateral damage to components in the plant (such as to the turbine) or valve failure. In this study, the microstructure formed near the Stellite/steel interface is investigated. Based on thermodynamic modelling, microstructure formed at these regions is hypothesised and a simple methodology is proposed to predict the occurrence of these failures. 相似文献
94.
95.
Nadendla Hari Babu Wai Lo David A. Cardwell 《Journal of the American Ceramic Society》2000,83(10):2622-2624
The dependence of growth rate on isothermal undercooling and composition has been investigated for Nd-Ba-Cu-O single grains containing various amounts of nonsuperconducting Nd4 Ba2 Cu2 O10 (Nd-422) phase inclusions and fabricated under a 1% O2 in N2 atmosphere using a top seeded melt growth technique. The growth rate along the crystallographic c -direction is observed to exceed that along the a / b direction at all undercooling temperatures and exhibits a maximum for a Nd-422 content of ∼10 mol%. The samples have been examined by optical microscopy and the results interpreted within an established planar solidification model. 相似文献
96.
97.
Kayala Mallikharjuna Babu P Martin Jebaraj M P Chowdiah 《Bulletin of Materials Science》1990,13(3):227-234
A full factorial 23 matrix was designed to study the bending strength, permeability and hoop-stress of investment moulds. A novel method of ethyl-silicate
hydrolysis; two-step hydrolysis, was used. The results indicate that the bending strength is directly proportional to the
quantity of filler material in the slurry. Grain size of stucco material appears to exert the least effect on bending and
hoop strength, whereas permeability increases slightly when coarser grain is used. 相似文献
98.
Incineration, in spite of being a costly option, is widely used for the treatment and disposal of solid, liquid, and gaseous wastes. Use of fluidized beds paved the way for less polluting incinerators. Circulating fluidized bed systems can burn low-heat-content watery wastes without (or with minimum) auxiliary fuel. Equations of heat transfer and heat balance for different zones of a recirculating fluidized bed (RCFB) incineration system are presented along with a computational procedure to predict the performance details of the system. The method presented is applied to compute the performance of an RCFB incineration system burning distillery spent wash. Results show that RCFB incinerators are capable of burning a spent wash of solids content considerably lower than 60%. The incineration units in operation at present concentrate spent wash to about 60% solids content in external evaporators for autogenous burning. This costly and difficult operation can be minimized by the use of RCFB for incineration. 相似文献
99.
100.
Micromechanical modeling of hybrid composites 总被引:1,自引:0,他引:1
The main aim of this work is to study the effective elastic modulus of hybrid composites through micromechanical modeling. The micromechanical framework based on the generalized method of cells has been employed for this study. The predictions based on the present model are compared with an assortment of experimental and other theoretical predictions. The effect of two types; sequential mode and mixed mode of filler additions on the effective elastic modulus of the hybrid composite are studied. Moreover, the effect of other microstructural parameters such as the concentration, shape and aspect ratio of fillers in altering the hybridization effects are also investigated. 相似文献