全文获取类型
收费全文 | 1664篇 |
免费 | 56篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 14篇 |
综合类 | 1篇 |
化学工业 | 597篇 |
金属工艺 | 48篇 |
机械仪表 | 18篇 |
建筑科学 | 38篇 |
能源动力 | 106篇 |
轻工业 | 105篇 |
水利工程 | 10篇 |
石油天然气 | 7篇 |
无线电 | 113篇 |
一般工业技术 | 336篇 |
冶金工业 | 94篇 |
原子能技术 | 24篇 |
自动化技术 | 214篇 |
出版年
2024年 | 6篇 |
2023年 | 18篇 |
2022年 | 43篇 |
2021年 | 60篇 |
2020年 | 42篇 |
2019年 | 44篇 |
2018年 | 77篇 |
2017年 | 59篇 |
2016年 | 71篇 |
2015年 | 24篇 |
2014年 | 51篇 |
2013年 | 117篇 |
2012年 | 81篇 |
2011年 | 115篇 |
2010年 | 75篇 |
2009年 | 68篇 |
2008年 | 81篇 |
2007年 | 66篇 |
2006年 | 66篇 |
2005年 | 47篇 |
2004年 | 35篇 |
2003年 | 26篇 |
2002年 | 37篇 |
2001年 | 15篇 |
2000年 | 20篇 |
1999年 | 19篇 |
1998年 | 20篇 |
1997年 | 14篇 |
1996年 | 13篇 |
1995年 | 22篇 |
1994年 | 14篇 |
1993年 | 23篇 |
1992年 | 21篇 |
1991年 | 15篇 |
1990年 | 26篇 |
1989年 | 15篇 |
1988年 | 15篇 |
1987年 | 21篇 |
1986年 | 16篇 |
1985年 | 19篇 |
1984年 | 15篇 |
1983年 | 18篇 |
1982年 | 17篇 |
1981年 | 21篇 |
1980年 | 10篇 |
1979年 | 8篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1967年 | 2篇 |
排序方式: 共有1725条查询结果,搜索用时 15 毫秒
1.
2.
The graft copolymerization of methyl methacrylate onto natural rubber (NR) was carried out varying the concentration of monomer, initiator, thiourea, and silver nitrate over a wide range. The grafting reaction was temperature-dependent. From the Arrhenius plot, the overall energy of activation was computed. A suitable reaction scheme and rate expression for the rate of polymerization was suggested. 相似文献
3.
The mechanism of the hypolipidemic effect of n-3 fatty acids was studied using isolated rat hepatocytes maintained in culture. EPA and DHA caused a significant reduction in the incorporation of 3[H]-leucine into apoB associated with the VLDL produced by hepatocytes in culture when compared to that in presence of palmitic acid. Presence of indomethacin, an inhibitor of cyclo-oxygenase reversed the effect of EPA on VLDL synthesis while diethyl carbamazine an inhibitor of lipoxygenase did not show any effect suggesting that the effect of EPA may be mediated through prostaglandins. This was further tested by invivo experiments where animals were fed fish oil containing diet with and without aspirin, which inhibits formation of prostaglandins. The incorporation of 3[H]-leucine into apo B and 14[C]-acetate into cholesterol of VLDL produced by hepatocytes from aspirin treated animals were significantly high. The reversal of the effect of n-3 fatty acids by agents which inhibit the formation of prostaglandin suggests that the n-3 fatty acids may exert their effect on VLDL production by liver cells through prostaglandins. 相似文献
4.
5.
In this paper we design a dynamic dictionary for
the priced information model initiated by Charikar et al. Assume that a set S consisting of n elements is given such that
each element has an associated price, a positive real number. The cost of performing an operation on elements of S is a function
of their prices. The cost of an algorithm is the sum of the costs of
all operations it performs. The objective is to design algorithms
which incur low cost. In this model we propose a dynamic dictionary, supporting
search, insert and delete, for keys drawn from a linearly ordered set.
As an application we show that the dictionary can be used in
computing the trapezoidal map of a set of line segments, a fundamental problem in
computational geometry. 相似文献
6.
7.
8.
Anil Kumar William R. Leo Lawrence Green Gene L. Woodruff 《Journal of Fusion Energy》1989,8(1-2):107-126
The neutron spectra transmitted across a fission-suppressed hybrid blanket and its components, driven by a low intensity 14 MeV Haefely neutron generator, were measured with a 2×2 NE213 detector at LOTUS facility. These experiments have been analyzed with 2D and 3D codes DOT3.5 and MCNP, respectively. The spectral integrals between 15 to 1 MeV show good agreement among the 2D, the 3D, and the NE213 for 15 cm lead, 18 cm beryllium, and 25 cm graphite slabs. However, there are large discrepancies for 6.2 cm stainless steel and 15 cm lithium carbonate slabs. The assemblies involving two or more of these slabs reflect these tendencies. We observe also considerable disagreement over pointwise spectra for a number of assemblies.Work done while on visiting assignment to Institut de Génie Atomique, E.P.F.L. 相似文献
9.
Viscosity data over a temperature range of 37-115°C and a pressure range of 0-10 MPa gauge are presented for a Cold Lake bitumen sample. These data show that the compression of Cold Lake bitumen results in a significant increase in its viscosity. Results are compared with those from a similar study on an Athabasca bitumen sample. Also presented are two correlations for the effects of pressure and temperature on the viscosity of Cold Lake bitumen. 相似文献
10.
A predictive model was developed for the fully developed zone of a circulating fluidized bed (CFB) riser reactor operating in the fast fluidization regime that overcomes limitations of existing models. The model accounts for the upward flow of gas and solids in the core and downward flow of the two phases in the annulus. Additionally, a numerical solution methodology for the simulation of a riser reactor employing the hydrodynamic model was devised. A simulation was performed using the fast, main Claus reaction to demonstrate the effects of backmixing in the fast fluidization regime. It was found that the molar flow rates of the reactants leaving a fast fluidized CFB riser reactor were significantly higher than those leaving an identical reactor operating in the pneumatic transport regime. 相似文献