全文获取类型
收费全文 | 56篇 |
免费 | 0篇 |
国内免费 | 3篇 |
专业分类
化学 | 25篇 |
力学 | 6篇 |
数学 | 18篇 |
物理学 | 10篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 1篇 |
2012年 | 5篇 |
2011年 | 1篇 |
2010年 | 3篇 |
2009年 | 3篇 |
2008年 | 1篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1998年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1974年 | 2篇 |
1972年 | 1篇 |
1970年 | 2篇 |
1968年 | 1篇 |
排序方式: 共有59条查询结果,搜索用时 15 毫秒
1.
Atomic-scale friction of a tungsten tip on a graphite surface 总被引:1,自引:0,他引:1
2.
We construct two bases of the natural numbers B1 and B2, eachof order two, such that (B1 + B2 (n) <n+c/(log n). For alower estimate, it is proved that if B2 and are two bases, eachof order two, then (B1+B2)(n) > n. Generalisations to sumsof bases of order h > 2 are also given. 相似文献
3.
Data are presented which show that when a polymer contains an appreciable amount of low molecular weight species below the diffusion limit of the osmometer membrane, the osmotic molecular weight, M?n, is generally higher than the M?n calculated from gel-permeation chromatography (GPC). Experiments were performed on samples of poly(vinyl chloride) (PVC) and high-cis polybutadiene polymers. Osmotic data were obtained in the usual manner, while GPC data were obtained using the universal calibration approach. It was found that when all polymer species below approximately 10,000 molecular weight were excluded from the calculation of M?n by GPC, agreement in M?n was obtained between membrane osmometry and GPC. The data obtained suggest that the choice of M?n as measured by membrane osmometry in the calibration of the GPC should not be done casually, as the measured M?n may not reflect the “true” value of that sample, especially when the polymer sample contains an appreciable amount of low molecular weight material. 相似文献
4.
Mate Wierdl 《Israel Journal of Mathematics》1988,64(3):315-336
The pointwise ergodic theorem is proved for prime powers for functions inL
p,p>1. This extends a result of Bourgain where he proved a similar theorem forp>(1+√3)/2.
This paper is a part of the author’s Ph.D. thesis supervised by V. Bergelson. 相似文献
5.
Roger?L.?JonesEmail author Joseph?M.?Rosenblatt Máté?Wierdl 《Israel Journal of Mathematics》2003,135(1):1-27
In this paper we continue our investigations of square function inequalities. The results in [9] are primarily one dimensional,
and here we extend all the results to multi-dimensional averages. Our basic tool is still a comparison of the ergodic averages
with various dyadic (reversed) martingales, but the Fourier transform arguments are replaced by more geometric almost orthogonality
arguments.
The results imply the pointwise ergodic theorem for the action of commuting measure preserving transformations, and give additional
information such as control of the number of upcrossings of the ergodic averages. Related differentiation results are also
discussed.
R. Jones is partially supported by NSF Grant DMS-9531526.
J. Rosenblatt is partially supported by NSF Grant DMS-9705228.
M. Wierdl is partially supported by NSF Grant DMS-9801602. 相似文献
6.
In this Note, we present a new formalism for nonlinear and non-separable multiscale representations. The new formalism we propose brings about similarities between existing nonlinear multiscale representations and also allows us to alleviate the classical hypotheses made to prove the convergence of the multiscale representations. 相似文献
7.
8.
Balint Farkas Mate Matolcsi Peter Mora 《Journal of Fourier Analysis and Applications》2006,12(5):483-494
Recent methods developed by Tao [18], Kolountzakis and Matolcsi [7] have led to counterexamples to Fugelde’s Spectral Set
Conjecture in both directions. Namely, in
Tao produced a spectral set which is not a tile, while Kolountzakis and Matolcsi showed an example of a nonspectral tile.
In search of lower dimensional nonspectral tiles we were led to investigate the Universal Spectrum Conjecture (USC) of Lagarias
and Wang [14]. In particular, we prove here that the USC and the "tile → spectral" direction of Fuglede’s conjecture are equivalent
in any dimensions. Also, we show by an example that the sufficient condition of Lagarias and Szabó [13] for the existence
of universal spectra is not necessary. This fact causes considerable difficulties in producing lower dimensional examples
of tiles which have no spectra. We overcome these difficulties by invoking some ideas of Révész and Farkas [2], and obtain
nonspectral tiles in
. Fuglede’s conjecture and the Universal Spectrum Conjecture remains open in 1 and 2 dimensions. The one-dimensional case
is closely related to a number theoretical conjecture on tilings by Coven and Meyerowitz [1]. 相似文献
9.
Journal of Nonlinear Science - The isothermal quasistatic (i.e. acceleration neglected) hardening-free plasticity at large strains is considered, based on the standard multiplicative decomposition... 相似文献
10.
Ivar M. McDonald Robert Mate Alicia Ng Hyunsoo Park Richard E. Olson 《Tetrahedron letters》2018,59(8):751-754
Three novel tricyclic diamines (1,7-diazaisoadamantane, 1,5-diazaisoadamantane and 1,6-diazahomobrendane) were prepared. A flexible synthetic strategy was employed which used flat, aromatic azaindoles as the starting materials. The requisite azaindoles were prepared by a tandem Sonogashira coupling/intramolecular cyclization reaction. Ring saturation, appropriate functionalization and intramolecular alkylation provided the three novel tricyclic diamines cores. 相似文献