全文获取类型
收费全文 | 2389篇 |
免费 | 48篇 |
国内免费 | 10篇 |
专业分类
化学 | 1798篇 |
晶体学 | 16篇 |
力学 | 33篇 |
数学 | 171篇 |
物理学 | 429篇 |
出版年
2023年 | 10篇 |
2022年 | 13篇 |
2021年 | 12篇 |
2020年 | 24篇 |
2019年 | 20篇 |
2018年 | 16篇 |
2017年 | 20篇 |
2016年 | 40篇 |
2015年 | 38篇 |
2014年 | 52篇 |
2013年 | 112篇 |
2012年 | 112篇 |
2011年 | 144篇 |
2010年 | 70篇 |
2009年 | 104篇 |
2008年 | 117篇 |
2007年 | 150篇 |
2006年 | 146篇 |
2005年 | 127篇 |
2004年 | 118篇 |
2003年 | 105篇 |
2002年 | 94篇 |
2001年 | 54篇 |
2000年 | 56篇 |
1999年 | 38篇 |
1998年 | 26篇 |
1997年 | 34篇 |
1996年 | 26篇 |
1995年 | 24篇 |
1994年 | 37篇 |
1993年 | 23篇 |
1992年 | 30篇 |
1991年 | 31篇 |
1990年 | 35篇 |
1989年 | 17篇 |
1988年 | 24篇 |
1987年 | 21篇 |
1986年 | 20篇 |
1985年 | 45篇 |
1984年 | 37篇 |
1983年 | 22篇 |
1982年 | 29篇 |
1981年 | 19篇 |
1980年 | 19篇 |
1979年 | 32篇 |
1978年 | 16篇 |
1977年 | 19篇 |
1976年 | 11篇 |
1975年 | 13篇 |
1974年 | 12篇 |
排序方式: 共有2447条查询结果,搜索用时 78 毫秒
1.
2.
Toshiyuki Sugawa 《Monatshefte für Mathematik》2003,139(1):61-68
The inner radius of univalence of a domain D with Poincaré density ρ
D
is the possible largest number σ such that the condition ∥ S
f
∥
D
= sup
w∈ D
ρ
D
(w)
−2∥ S
f
(z) ∥ ≤ σ implies univalence of f for a nonconstant meromorphic function f on D, where S
f
is the Schwarzian derivative of f. In this note, we give a lower bound of the inner radius of univalence for strongly starlike domains of order α in terms
of the order α.
The author was partially supported by the Ministry of Education, Grant-in-Aid for Encouragement of Young Scientists, 11740088.
A part of this work was carried out during his visit to the University of Helsinki under the exchange programme of scientists
between the Academy of Finland and the JSPS.
Received November 26, 2001; in revised form September 24, 2002
Published online May 9, 2003 相似文献
3.
Regularity of Harmonic Functions in Cheeger-Type Sobolev Spaces 总被引:3,自引:0,他引:3
We give a geometric approach to the study of the regularity of harmonic functions in Cheeger-type Sobolev spaces, and prove the Hölder continuity of such functions. In the proof, we give a definition of an upper curvature bound of the unit sphere of a Banach space, which seems to be of independent interest. 相似文献
4.
We have investigated the photoluminescence (PL) properties of trace amounts of Pr and Tb in single-crystal samples of yttria-stabilized zironia (YSZ), and found that Pr of the order of 10−6 mass% and Tb of the order of 10−5 mass% in YSZ can be detected by the PL spectroscopy. The PL spectra of the YSZ samples for the 280 nm excitation were comprised of several peaks and a broad emission. The peaks were attributed to transitions of Pr3+ and Tb3+ in the YSZ samples, whereas the broad emission seemed to be attributed to the yttria-associated oxygen vacancies. The peak intensities corresponded to the amounts of Pr and Tb in the YSZ samples, the amounts of which were analyzed by glow discharge mass spectrometry. In the PL excitation spectra, but not in the photoabsorption spectra, small peaks at 376 and 381 nm were observed, and were attributed to the transitions of Tb3+ in the YSZ samples. The results of the PL excitation spectra corresponding to the Pr3+ line emissions suggest that the charge transfer occurs between the YSZ and Pr ion in it. The trace amounts of these lanthanoids in YSZ would disturb the decay process of the photoinduced electrons to the yttria-associated oxygen vacancies. 相似文献
5.
Toshiyuki Kuruma 《Zeitschrift fur Physik C Particles and Fields》1993,57(4):551-558
The top quark, once produced, should be an important window to the electroweak symmetry breaking sector. We compute electroweak radiative corrections to the decay processt→b+W + in order to extract information on the Higgs sector and to fix the background in searches for a possible new physics contribution. The large Yukawa coupling of the top quark induces a new form factor through vertex corrections and causes discrepancy from the tree-level longitudinalW-boson production fraction, but the effect is of order 1% or less form H<1 TeV. 相似文献
6.
This article concerns several geometric properties of metricmeasure spaces satisfying the measure contraction property (MCP),which can be considered as a generalized notion of lower Riccicurvature bounds. We prove that the MCP of spaces descends totheir products and Euclidean cones. We also show that a positivelycurved space in terms of the MCP with a maximal diameter canbe represented as the spherical suspension of some topologicalmeasure space. 相似文献
7.
A new 20-membered macrolide designated exiguolide has been isolated from the marine sponge Geodia exigua, and its structure determined by interpretation of spectroscopic data. Exiguolide specifically inhibited fertilization of sea urchin (Hemicentrotus pulcherrimus) gametes but not embryogenesis of the fertilized egg. 相似文献
8.
Hoon Kim Toshihiko Koseki Tomohiro Ohta Hiroshi Sato Yukihiro Shimogaki 《Applied Surface Science》2006,252(11):3938-3942
The adhesion of Cu on Ru substrates with different crystal orientations was evaluated. The crystal orientation of sputter deposited Ru could be changed from (1 0 0) to (0 0 1) by annealing at 650 °C for 20 min. The adhesion of Cu was evaluated by the degree of Cu agglomeration on Ru. Cu films on annealed Ru films with the (0 0 1) crystal orientation showed 28% lower RMS values and 50% lower Ru surface coverage than Cu as-deposited on Ru having the (1 0 0) crystal orientation after annealing at 550 °C for 30 min, which suggest that Cu wettability on the Ru(0 0 1) was better than that on the Ru(1 0 0) plane. The low lattice misfit of 4% between Cu(1 1 1) and Ru(0 0 1) may be the reason for this good adhesion property. 相似文献
9.
Toshiyuki Kobayashi 《Mathematische Annalen》1989,285(2):249-263
Partially supported by Grant-in-Aid for Scientific Research (No. 63740074) 相似文献
10.