全文获取类型
收费全文 | 2103篇 |
免费 | 91篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 36篇 |
综合类 | 4篇 |
化学工业 | 587篇 |
金属工艺 | 67篇 |
机械仪表 | 27篇 |
建筑科学 | 102篇 |
矿业工程 | 12篇 |
能源动力 | 35篇 |
轻工业 | 198篇 |
水利工程 | 4篇 |
石油天然气 | 3篇 |
无线电 | 145篇 |
一般工业技术 | 453篇 |
冶金工业 | 208篇 |
原子能技术 | 16篇 |
自动化技术 | 302篇 |
出版年
2023年 | 25篇 |
2022年 | 28篇 |
2021年 | 55篇 |
2020年 | 40篇 |
2019年 | 32篇 |
2018年 | 51篇 |
2017年 | 38篇 |
2016年 | 55篇 |
2015年 | 51篇 |
2014年 | 69篇 |
2013年 | 106篇 |
2012年 | 107篇 |
2011年 | 127篇 |
2010年 | 96篇 |
2009年 | 99篇 |
2008年 | 107篇 |
2007年 | 95篇 |
2006年 | 77篇 |
2005年 | 65篇 |
2004年 | 73篇 |
2003年 | 54篇 |
2002年 | 52篇 |
2001年 | 39篇 |
2000年 | 45篇 |
1999年 | 36篇 |
1998年 | 50篇 |
1997年 | 33篇 |
1996年 | 36篇 |
1995年 | 33篇 |
1994年 | 23篇 |
1993年 | 16篇 |
1992年 | 32篇 |
1991年 | 19篇 |
1990年 | 27篇 |
1989年 | 17篇 |
1988年 | 15篇 |
1987年 | 18篇 |
1986年 | 22篇 |
1985年 | 26篇 |
1984年 | 16篇 |
1983年 | 16篇 |
1982年 | 11篇 |
1981年 | 8篇 |
1980年 | 13篇 |
1979年 | 13篇 |
1978年 | 8篇 |
1977年 | 16篇 |
1976年 | 20篇 |
1974年 | 10篇 |
1971年 | 11篇 |
排序方式: 共有2199条查询结果,搜索用时 0 毫秒
61.
Rainer Steegmüller Jochen Ulmer Michael Quellmalz Markus Wohlschlögel Andreas Schüßler 《Journal of Materials Engineering and Performance》2014,23(7):2450-2456
New ingot qualities, processed by optimized vacuum arc remelting (VAR), optimized vacuum induction melting followed by VAR and VAR followed by electron beam remelting, were compared with standard quality. Finished components as well as diamond-shaped samples representing a typical dimension of self-expanding stents were produced using Nitinol tubing drawn from the new ingot qualities. Metallographic longitudinal sections were prepared and analyzed to determine inclusion size and distributions of the various ingot qualities. Radial force and uniaxial tensile tests were used to determine the mechanical properties of fully processed material and tubing, respectively. Transformation temperatures of tubing as delivered from supplier and processed stents were measured by differential scanning calorimetry and deformation-and-free-recovery testing. Finally, fatigue tests were performed on diamond-shaped samples to evaluate the strain-life characteristics of the new ingot qualities. Results of this study are compared to ADMEDES historical data from standard Nitinol materials to gain an assessment of the new improved ingot qualities with regard to the production of Nitinol vascular implants. The latest developments in Nitinol ingot quality are highlighted and the results of the comparison from technical point of view are shown. 相似文献
62.
63.
64.
Rainer Dahlhaus 《时间序列分析杂志》2012,33(1):13-31
In this article, we consider frequency and phase estimation in a noisy oscillation with potentially non‐constant phase increments resulting from an underlying non‐constant frequency. A maximum periodogram method on segments is used to estimate the time‐varying frequency and a subsequent least squares approach to estimate the phase. A key problem addressed in this article is the question how to set up a meaningful concept of asymptotic statistics for this model. This problem is solved by a special infill asymptotics concept. We use this concept to prove consistency and asymptotic normality of the estimates. Furthermore, the phase estimate is compared to the Hilbert transform in a simulation. 相似文献
65.
66.
Electronic Markets - The restaurant technology market is rapidly evolving and is transforming the restaurant business as a significant sector of tourism and hospitality. Enabled by artificial... 相似文献
67.
Electronic Markets - 相似文献
68.
Digital Twins are new solution elements to enable ongoing digital monitoring and active functional improvement of interconnected products, devices and machines. In addition, benefits of horizontal and vertical integration in manufacturing are targeted by the introduction of Digital Twins. Using the test environment of smart factory cells, this paper investigates methodological, technological, operative, and business aspects of developing and operating Digital Twins. The following Digital Twin dimensions are considered in scientific and application oriented analysis: (1) integration breadth, (2) connectivity modes, (3) update frequency, (4) CPS intelligence, (5) simulation capabilities, (6) digital model richness, (7) human interaction, and (8) product lifecycle. From this, design elements for the development of Digital Twins are derived and presented. 相似文献
69.
Software and Systems Modeling - 相似文献
70.
Rainer Alt 《Electronic Markets》2018,28(2):123-128