全文获取类型
收费全文 | 1988篇 |
免费 | 81篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 18篇 |
综合类 | 16篇 |
化学工业 | 518篇 |
金属工艺 | 45篇 |
机械仪表 | 48篇 |
建筑科学 | 61篇 |
矿业工程 | 2篇 |
能源动力 | 25篇 |
轻工业 | 356篇 |
水利工程 | 8篇 |
石油天然气 | 1篇 |
无线电 | 106篇 |
一般工业技术 | 339篇 |
冶金工业 | 274篇 |
原子能技术 | 25篇 |
自动化技术 | 230篇 |
出版年
2022年 | 23篇 |
2021年 | 33篇 |
2020年 | 22篇 |
2018年 | 39篇 |
2017年 | 36篇 |
2016年 | 36篇 |
2015年 | 44篇 |
2014年 | 42篇 |
2013年 | 97篇 |
2012年 | 61篇 |
2011年 | 68篇 |
2010年 | 70篇 |
2009年 | 62篇 |
2008年 | 58篇 |
2007年 | 70篇 |
2006年 | 63篇 |
2005年 | 51篇 |
2004年 | 46篇 |
2003年 | 38篇 |
2002年 | 41篇 |
2001年 | 37篇 |
2000年 | 23篇 |
1999年 | 31篇 |
1998年 | 92篇 |
1997年 | 60篇 |
1996年 | 53篇 |
1995年 | 47篇 |
1994年 | 46篇 |
1993年 | 29篇 |
1992年 | 32篇 |
1991年 | 21篇 |
1990年 | 30篇 |
1989年 | 27篇 |
1988年 | 29篇 |
1987年 | 30篇 |
1986年 | 20篇 |
1985年 | 25篇 |
1984年 | 27篇 |
1983年 | 24篇 |
1982年 | 24篇 |
1981年 | 24篇 |
1980年 | 25篇 |
1979年 | 21篇 |
1978年 | 33篇 |
1977年 | 32篇 |
1976年 | 36篇 |
1975年 | 20篇 |
1974年 | 23篇 |
1973年 | 24篇 |
1971年 | 18篇 |
排序方式: 共有2072条查询结果,搜索用时 15 毫秒
1.
Marcus Heinze Sandra Starke Marcel Händler Hartmut Komber Marco Drache Norbert Moszner Brigitte Voit Doris Pospiech 《应用聚合物科学杂志》2019,136(48):48256
We demonstrate in this study that the combination of modern inline monitoring methods [here: inline nuclear magnetic resonance (NMR)] with simulations gains more exact and profound kinetic results than previously used methods like linearization without that combination. The 1H-NMR spectroscopic data (more than 100 data points) are used to construct the copolymerization diagram. The reactivity ratios are obtained applying the van Herks nonlinear least square method. The examination of the radical copolymerization of 2-hydroxyethyl methacrylate (HEMA) with (2-{[2-(ethoxycarbonyl)prop-2-en-1-yl]oxy}ethyl) phosphonic acid (ECPPA) as important adhesive monomer used in dentistry yields reactivity ratios of rHEMA = 1.83; rECPPA = 0.42. The copolymerization diagram reflects nonideal, non-azeotropic copolymerization. The sequence distribution of the obtained by Monte Carlo simulation indicates the generation of statistical copolymers. As an important finding, it is demonstrated that the repeating units responsible for etching and adhesion are arranged over the whole polymer chain, which is necessary to achieve proper functionality. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48256. 相似文献
2.
Makrina A. Chairopoulou Fabian Kratzer Roland Gross Michael Herrmann Ulrich Teipel 《化学工程与技术》2020,43(5):904-912
Thermogravimetric analysis of a coccolith-containing biogenic broth showed a three-step degradation process. According to this system behavior, the biogenic broth was heated to specific temperatures and characterized in terms of its morphology, surface chemistry, and crystallinity. The elemental and organic composition of the treated samples was also evaluated and compared to the reference material. The presented results were acquired in an effort to exploit pretreatment scenarios for such a biogenic system that would improve and support a separation process. 相似文献
3.
Direct charging of thin slabs of low carbon steel (0.05%C) was investigated by using laboratory tests on a thin-slab-casting Simulator linked with the hot deformation Simulator (Wumsi). Starting with a different initial thickness of simulated thin slabs (45 down to 25 mm) the total strain ?∑ was varied. Hot deformation schedules (with and without roughing) with different finishing temperatures TF lead to some differences in the hot strip microstructure. Nevertheless, after cold rolling and batch annealing, a rather uniform pancake-structure and a pronounced {111}-texture were achieved in the cold strip without any significant relation to the processing routs. The measurement of final mechanical properties proved that a good deep drawability of cold strip can be achieved with direct charging of thin slabs, well comparable to that after a conventional cold charging of thick slabs. 相似文献
4.
Computing surfaces invariant under subdivision 总被引:3,自引:0,他引:3
In this paper, we propose a general subdivision algorithm for generating surfaces. The algorithm has as motivation our earlier work on the design of free form curves where similar ideas were investigated. Here we describe some properties of uniform refinement algorithms for surface generation. A detail analysis of their properties will be given later by one of us. 相似文献
5.
Herrmann C. 《Information and Computation》1995,122(2)
The implication and finite implication problems for embedded multivalued database dependencies are both shown to be algorithmically undecidable. The proof is by an interpretation of semigroup word problems via systems of permuting equivalence relations into database dependencies. In contrast, it is shown that for each fixed premise H one has a decision procedure for implications H F. 相似文献
6.
The choice of a highly resistive substrate for silicon millimeter-wave integrated circuits (SIMMWIC) imposed by the requirement of low RF-substrate losses requires the adaptation of a CMOS process on float zone silicon (FZ). A comparison of n- and p-channel devices realized on high resistivity substrate (p-type, 5000 Ω·cm) and standard CMOS substrates (CZ, n-type, 4-6 Ω·cm) is given. Using careful process design, we obtained device characteristics on FZ-substrates that are closely similar to those on standard material, thus allowing direct transfer of existing circuit designs 相似文献
7.
Neben der Gestaltung technischer Systeme zur Unterstützung des Wissensmanagements ist die Ausgestaltung organisatorischer
Ma?nahmen gleichbedeutend wichtig. 相似文献
8.
9.
10.