全文获取类型
收费全文 | 221篇 |
免费 | 7篇 |
国内免费 | 1篇 |
专业分类
化学 | 155篇 |
晶体学 | 6篇 |
力学 | 2篇 |
数学 | 9篇 |
物理学 | 57篇 |
出版年
2022年 | 3篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 8篇 |
2013年 | 7篇 |
2012年 | 8篇 |
2011年 | 10篇 |
2010年 | 3篇 |
2009年 | 7篇 |
2008年 | 12篇 |
2007年 | 8篇 |
2006年 | 19篇 |
2005年 | 11篇 |
2004年 | 10篇 |
2003年 | 10篇 |
2002年 | 6篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 4篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1944年 | 1篇 |
1942年 | 3篇 |
1941年 | 4篇 |
1935年 | 2篇 |
排序方式: 共有229条查询结果,搜索用时 31 毫秒
61.
Reduction of Ordering Temperature of FePt-Al2O3 Thin Films by N2 Addition During Sputtering
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We investigate the effect of N2 addition during sputtering on the microstructure and magnetic properties of FePt-Al2O3 thin films. The texture of FePt phase in FePt-Al2O3 thin films changes from (111) to a more random orientation by N2 addition during sputtering. The ordering temperature of FePt phase reduces about 100℃ with appropriate N2 partial pressure. A larger coercivity of 6.0 × 10^5 Aim is obtained with N2 partial pressure about 15%. Structural analysis reveals that a small quantity of Fe3N phase forms during sputtering and the release of N atoms during the post annealing induces a large number of vacancies in the films, which benefits to the transformation of FePt phase from fcc to fct. 相似文献
62.
63.
64.
65.
A surface-adsorbed monolayer of cap-shaped gold particles upon submicrometer-sized polystyrene spheres exhibits pronounced absorption in the visible region. When the surrounding refractive index was altered by immersion in a fluid, the direction of the shift in the absorption spectrum was dependent on the incidence angle of the irradiation. When a thiol molecule, known to adsorb selectively on gold upon polystyrene, was added, the resultant shift in the absorption spectrum's peak was consistently toward longer wavelengths. Consequently, at certain incidence angles, a change in the refractive index of the surrounding fluid produces no shift, whereas thiol adsorption results in a clear shift, apparently reflecting the different spatial regions in which the refractive index is altered by these two procedures. 相似文献
66.
Takei I Nishibayashi Y Ishii Y Mizobe Y Uemura S Hidai M 《Chemical communications (Cambridge, England)》2001,(22):2360-2361
Chiral ruthenium(II) complexes, RuCl2(PPh3)(oxazolinylferrocenylphosphine), have been found to be effective catalysts for asymmetric hydrosilylation of ketoximes to give the corresponding primary amines in good yields with high enantioselectivities (up to 89% ee) after acid hydrolysis. 相似文献
67.
[structure: see text]. Michael addition of various enolates toward gamma-CH(3-n)F(n)-alpha,beta-unsaturated ketones (n = 1-3) was proven to smoothly furnish the 1,4-adducts with high si face selectivities which monotonously decreased by reduction in the number of fluorines. Although the Felkin-Anh model correctly anticipates the present stereochemical outcome only with E-acceptors, the hyperconjugative stabilization of transition states by electron donation from the allylic substituents (the Cieplak rule) successfully explains the pi-facial preference of both acceptors at least in a qualitative level. 相似文献
68.
A new reconstruction method called sampled pattern matching (SPM) was applied to the image reconstruction of an electrical
capacitance computed tomography in powder flow in a vertical pipe for petroleum refinery process. This new method is able
to achieve stable convergence without the use of an empirical value. Experiments were carried out using fluid catalytic cracking
(FCC) catalysts as powder with two air volume flow rates and four powder volume flow rates to measure the capacitance of a
pipe cross section. The SPM method is compared with conventional methods in terms of volume fraction, residual capacitance,
and correlation capacitance. Overall, the SPM method proved superior to conventional methods without any empirical value because
SPM achieves accurate reconstruction by using an objective function that is calculated as the inner product calculation between
the experimental capacitance and the reconstructed image capacitance. 相似文献
69.
The reaction of anilines, benzaldehydes, and ethyl 3,3-diethoxypropionate in the presence of Yb(OTf)3 proceeded under mild reaction conditions to give dihydropyridines (DHPs). We have found that the reaction depended on the solvent and the DHPs were obtained selectively in 1,4-dioxane as a solvent. Various 2,6-unsubstituted DHPs were synthesized in one pot in satisfactory yields. 相似文献
70.
We develop the exact WKB analysis of an M2P1T (merging two simple poles and one simple turning point) Schrödinger equation. Our emphasis is put on the analysis of the singularity structure of its Borel transformed WKB solutions near fixed singular points relevant to the two simple poles contained in the potential of the equation. In Part I, we focus our attention on the construction and analytic properties of a WKB-theoretic transformation that transforms an M2P1T equation to an algebraic Mathieu equation. That transformation plays an important role in Part II ([7]) when we discuss the singularity structure of Borel transformed WKB solutions of an M2P1T equation. 相似文献