全文获取类型
收费全文 | 209篇 |
免费 | 10篇 |
国内免费 | 2篇 |
专业分类
化学 | 130篇 |
晶体学 | 1篇 |
力学 | 4篇 |
数学 | 53篇 |
物理学 | 33篇 |
出版年
2024年 | 2篇 |
2021年 | 1篇 |
2020年 | 7篇 |
2019年 | 9篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 5篇 |
2013年 | 9篇 |
2012年 | 14篇 |
2011年 | 16篇 |
2010年 | 6篇 |
2009年 | 10篇 |
2008年 | 20篇 |
2007年 | 14篇 |
2006年 | 7篇 |
2005年 | 11篇 |
2004年 | 8篇 |
2003年 | 12篇 |
2002年 | 17篇 |
2001年 | 2篇 |
2000年 | 7篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1993年 | 2篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1961年 | 1篇 |
1956年 | 2篇 |
排序方式: 共有221条查询结果,搜索用时 15 毫秒
61.
23种挥发性有机化合物在3种吸附剂上漏出容量的测定评价 总被引:4,自引:0,他引:4
采用吸附热解吸-气相色谱-质谱法对23种挥发性有机化合物Chromosorb 106、Tenax TA、Tenax TG等3种吸附剂上漏出容量进行了测定。根据实验结果确定了不同的化合物应选择不同的吸附剂及相应的采样体积。结果表明,Chromosorb 106可较好地吸附低沸点的挥发性有机化合物,Tenax TA、Tenax TG均可用于沸点较高的挥发笥有机化合物吸附,这对测定大气中的有机化合物含量采样有一定的参考价值。 相似文献
62.
63.
64.
Moritz T. Lessmann Aida Calvo Christopher D. Hardie Michael Porton Nerea Ordás Carmen García-Rosales 《哲学杂志》2016,96(32-34):3570-3585
The brittle fracture strength of a self-passivating W-Cr10-Ti2 alloy (in wt.%) was measured through un-notched cantilever bending at the microscopic scale. The material behaved purely elastic and fractured catastrophically in an unstable fashion. An average nominal strength of 5.9 GPa was measured. The scatter in strength was shown to be significantly higher than the sum of all random errors indicating an inherent variability of the material’s strength. The measurements from 28 tests followed a Weibull distribution with a modulus of m = 12. Results from a size effect study at the microscopic scale were successfully predicted through Weibull scaling. Extrapolation into the macroscopic range overestimated the measured three-point bend strength, which is likely due to the presence of large-scale heterogeneities. The test technique sampled a material thickness of only several micrometres and is hence suitable for future ion irradiation studies. 相似文献
65.
Elsa Callini Zuleyha Özlem Kocabas Atakli Bjørn C. Hauback Shin-ichi Orimo Craig Jensen Martin Dornheim David Grant Young Whan Cho Ping Chen Bjørgvin Hjörvarsson Petra de Jongh Claudia Weidenthaler Marcello Baricco Mark Paskevicius Torben R. Jensen Mark E. Bowden Thomas S. Autrey Andreas Züttel 《Applied Physics A: Materials Science & Processing》2016,122(4):353
66.
In this paper, we present a theory of vector-valued growth rates for discrete- and continuous-time semiflows on Hausdorff
spaces. For a given compact flow-invariant set M and an associated growth rate, we introduce the uniform growth spectrum over M, and associated real-valued spectra via projections of the vector-valued spectrum onto one-dimensional subspaces. We show
that these real-valued spectra are closed intervals if M is additionally connected. We also define the Morse spectrum associated with a growth rate by evaluating the growth rate
along chains. Moreover, we relate the uniform growth spectrum to the Morse spectrum and we analyze the meaning of limit sets
for the long-time behavior of growth rates. 相似文献
67.
68.
69.
Markus Gruyters Torben Pingel Richard Berndt 《Applied Physics A: Materials Science & Processing》2014,114(2):363-366
Single Fe atoms are deposited on hydrogen-passivated Si(111) surfaces by decomposition of FePc molecules. The metal-organic molecules are evaporated from powder in a heated crucible of an electron beam source. Scanning tunneling microscopy (STM) indicates the incorporation of the central Fe atom of the molecule into H/Si(111) in the near-surface region. This provides a possible precursor state for implantation deeper into the semiconductor substrate. 相似文献
70.