全文获取类型
收费全文 | 232篇 |
免费 | 5篇 |
专业分类
化学 | 117篇 |
晶体学 | 2篇 |
力学 | 3篇 |
数学 | 13篇 |
物理学 | 102篇 |
出版年
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 6篇 |
2017年 | 4篇 |
2016年 | 8篇 |
2015年 | 9篇 |
2014年 | 5篇 |
2013年 | 9篇 |
2012年 | 17篇 |
2011年 | 28篇 |
2010年 | 13篇 |
2009年 | 9篇 |
2008年 | 11篇 |
2007年 | 12篇 |
2006年 | 12篇 |
2005年 | 15篇 |
2004年 | 5篇 |
2003年 | 8篇 |
2002年 | 5篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1985年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1961年 | 1篇 |
1960年 | 1篇 |
1959年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有237条查询结果,搜索用时 312 毫秒
11.
The nearside distribution of particles at intermediate transverse momentum, associated with a high momentum trigger hadron produced in a high energy heavy-ion collision, is broadened in rapidity compared with the jet cone. This broadened distribution is thought to contain the energy lost by the progenitor parton of the trigger hadron. We show that the broadening can be explained as the final-state deflection of the gluons radiated from the hard parton inside the medium by soft, transversely oriented, turbulent color fields that arise in the presence of plasma instabilities. The magnitude of the effect is found to grow with medium size and density and diminish with increasing energy of the associated hadron. 相似文献
12.
Barun Majumder 《Physics letters. [Part B]》2011,701(4):384-387
Recently Ali et al. (2009) [13] proposed a Generalized Uncertainty Principle (or GUP) with a linear term in momentum (accompanied by Planck length). Inspired by this idea we examine the Wheeler-DeWitt equation for a Schwarzschild black hole with a modified Heisenberg algebra which has a linear term in momentum. We found that the leading contribution to mass comes from the square root of the quantum number n which coincides with Bekenstein?s proposal. We also found that the mass of the black hole is directly proportional to the quantum number n when quantum gravity effects are taken into consideration via the modified uncertainty relation but it reduces the value of mass for a particular value of the quantum number. 相似文献
13.
14.
M. Jain S.B. Majumder R.S. Katiyar A.S. Bhalla F.A. Miranda F.W. Van Keuls 《Applied Physics A: Materials Science & Processing》2005,80(3):645-647
Sol–gel deposition of highly oriented Ba0.5Sr0.5TiO3:MgO composite thin films has shown desirable dielectric constant reduction and higher figure of merit for phase-shifter applications. In this multilayer configuration, MgO distributed homogeneously through the Ba0.5Sr0.5TiO3 (BST50) matrix, and it helped in tailoring the dielectric constant and reducing the loss tangent significantly. In the present study, the high-frequency dielectric behavior of the films has been evaluated by fabricating an eight-element coupled microstrip phase shifter and measuring the degree of phase shift and insertion loss as a function of applied voltage at room temperature. An increase in phase-shifter figure of merit (degree of phase shift per dB insertion loss) from 28°/dB for pure BST50 to 71°/dB for a BST50:MgO film (at 14 GHz and 333 kV/cm) has been observed. PACS 77.55.+f; 81.20.Fw; 73.40.-c; 85.50.-n 相似文献
15.
Majumder G Abe K Abe K Adachi I Aihara H Asano Y Aulchenko V Aushev T Bahinipati S Bakich AM Banerjee S Bedny I Bitenc U Bizjak I Blyth S Bondar A Bozek A Bracko M Brodzicka J Browder TE Chang MC Chang P Chao Y Chen A Chen KF Chen WT Cheon BG Chistov R Choi Y Chuvikov A Cole S Dalseno J Danilov M Dash M Drutskoy A Eidelman S Enari Y Fratina S Gabyshev N Gershon T Go A Gokhroo G Golob B Gorisek A Haba J Hara T Hastings NC Hayasaka K Hayashii H Hazumi M Hinz L Hokuue T Hoshi Y Hou S Hou WS 《Physical review letters》2005,95(4):041803
We report evidence for B(0) --> D(0)D(-) and the first observation of the decay modes B(-) --> D(0)D(-) and B(-) --> D(0)D(*-) based on a sample of 152 x 10(6) BB events collected by the Belle detector at KEKB. The branching fractions for B(0) --> D(+) D(-), B--->D(0)D(-), and B--> D(0)D(*-) are found to be (1.91 +/- 0.51 +/- 0.30) x10(-4), (4.83 +/- 0.78 +/- 0.58) x 10(-4), and (4.57 +/- 0.71 +/- 0.56) x 10(-4), respectively. Charge asymmetries in the B---> D(0)D(-) and B(-) --> D(0)D(*-) channels are consistent with zero. 相似文献
16.
We show that, when a turbid medium with a layered fluorophore distribution is excited by linearly polarized light, measurement of angle-resolved polarized fluorescence can provide depth-resolved fluorescence measurements. 相似文献
17.
M.?Jain S.B.?Majumder R.S.?Katiyar Email author S.B.?Desu 《Applied Physics A: Materials Science & Processing》2003,77(6):789-792
We have investigated the relations between microstructure and dielectric properties in order to fabricate sol-gel-derived highly (100) oriented Ba0.5Sr0.5TiO3 (BST 50/50) thin films with properties comparable to those of the bulk material. For the first time, we were able to fabricate BST thin films which exhibited the orthorhombic-to-tetragonal transition in addition to the commonly observed tetragonal-to-cubic transition. We were successful in explaining the commonly observed degradation of the dielectric behavior of BST thin films, when compared to that of the bulk material, in terms of grain size, compositional inhomogeneity (measured in terms of Sr/Ba ratio) between the grain bulk and grain boundary, and mechanical stresses. PACS 77.55.+f; 77.22Gm; 77.80.Bh; 77.80.Dj 相似文献
18.
19.
We investigate orthogonal and symplectic bundles with parabolic structure, over a curve. 相似文献
20.
Susanta Hazra Samit Majumder Michel Fleck Núria Aliaga-Alcalde Sasankasekhar Mohanta 《Polyhedron》2009,28(17):3707-3714
Synthesis, molecular and supramolecular structures, electrochemistry and magnetic properties of two diphenoxo-bridged dicopper(II) compounds [CuII2L(H2O)(ClO4)]·ClO4·2H2O (1) and [CuII2L(N3)2]·2H2O (2) derived from a tetraimino diphenolate macrocyclic ligand H2L, obtained on [2+2] condensation of 4-methyl-2,6-diformylphenol and 2,2′-dimethyl-1,3-diaminopropane, are presented. Supramolecular structure of both 1 and 2 are three-dimensional resulting from hydrogen bonding interactions. Interestingly, the 3-D self-assembly of 2 contains micropores having the dimension of 0.35 nm. Electrochemical analyses reveal that both of these compounds exhibit two-step couples in the reduction window. Variable-temperature (2–300 K) magnetic susceptibilities measurements of the two compounds reveal that the metal centers in both of the complexes are coupled by strong antiferromagnetic interactions with J values (H = ?JS1·S2) ?776 and ?836 cm?1 for 1 and 2, respectively. 相似文献