全文获取类型
收费全文 | 1902篇 |
免费 | 68篇 |
国内免费 | 8篇 |
专业分类
化学 | 1310篇 |
晶体学 | 15篇 |
力学 | 42篇 |
数学 | 128篇 |
物理学 | 483篇 |
出版年
2023年 | 26篇 |
2022年 | 35篇 |
2021年 | 41篇 |
2020年 | 42篇 |
2019年 | 56篇 |
2018年 | 40篇 |
2017年 | 39篇 |
2016年 | 49篇 |
2015年 | 30篇 |
2014年 | 50篇 |
2013年 | 122篇 |
2012年 | 141篇 |
2011年 | 137篇 |
2010年 | 89篇 |
2009年 | 58篇 |
2008年 | 112篇 |
2007年 | 91篇 |
2006年 | 76篇 |
2005年 | 111篇 |
2004年 | 61篇 |
2003年 | 51篇 |
2002年 | 33篇 |
2001年 | 45篇 |
2000年 | 30篇 |
1999年 | 24篇 |
1998年 | 14篇 |
1997年 | 21篇 |
1996年 | 18篇 |
1995年 | 20篇 |
1994年 | 14篇 |
1993年 | 16篇 |
1992年 | 12篇 |
1991年 | 13篇 |
1989年 | 10篇 |
1988年 | 15篇 |
1986年 | 11篇 |
1985年 | 19篇 |
1984年 | 20篇 |
1983年 | 10篇 |
1982年 | 17篇 |
1981年 | 9篇 |
1980年 | 10篇 |
1979年 | 9篇 |
1978年 | 12篇 |
1977年 | 8篇 |
1976年 | 8篇 |
1975年 | 11篇 |
1974年 | 8篇 |
1971年 | 8篇 |
1970年 | 9篇 |
排序方式: 共有1978条查询结果,搜索用时 62 毫秒
991.
992.
A K Pal A K Bhunia R N Mukherjee 《The Journal of the Operational Research Society》2005,56(1):113-118
This paper investigates a deterministic inventory system for single item with three-component demand rate. This rate is dependent on selling price, frequency of advertisement and displayed stock level (DSL) in a showroom/shop. Shortages, if any, are allowed and backlogged partially. The storage capacity of the showroom/shop is assumed to be limited (finite). Different scenarios and subscenarios of the system have been mentioned and developed. Some numerical examples are given to illustrate the model. A sensitivity analysis is performed graphically to investigate the effect of changes of the system parameters on the optimal average profit. 相似文献
993.
994.
995.
B. Saha A. N. Sil A. K. Das P. K. Mukherjee 《International journal of quantum chemistry》2005,102(2):158-164
Energy levels of two interacting mass points in an anharmonic model potential (Morse type) have been studied. Analytic expression for the energy levels has been worked out. The model potential is shown to support bound states under certain conditions. The number of such states has been found to depend on the parameters of the potential. The potential is expected to be more realistic, particularly in presence of environments for diatomic molecules and artificial atoms. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005 相似文献
996.
A stereocontrolled total synthesis of (±)-norzizanone 1 has been efficiently accomplished involving base-induced rearrangement of the mesylate 17 as the key step. Aryl participated intramolecular cyclisation of the bromophenol 11 provided the tricyclic dienone 12, which was stereoselectively converted into the mesylate 17. 相似文献
997.
Sayan Mukherjee Partha Niyogi Tomaso Poggio Ryan Rifkin 《Advances in Computational Mathematics》2006,25(1-3):161-193
Solutions of learning problems by Empirical Risk Minimization (ERM) – and almost-ERM when the minimizer does not exist – need
to be consistent, so that they may be predictive. They also need to be well-posed in the sense of being stable, so that they might be used robustly. We propose a statistical form of stability, defined as leave-one-out (LOO) stability. We prove that for bounded loss classes LOO stability is (a) sufficient for generalization, that is convergence in probability of the empirical error to the expected error, for any algorithm satisfying it and, (b)
necessary and sufficient for consistency of ERM. Thus LOO stability is a weak form of stability that represents a sufficient condition for generalization for symmetric learning
algorithms while subsuming the classical conditions for consistency of ERM. In particular, we conclude that a certain form
of well-posedness and consistency are equivalent for ERM.
Dedicated to Charles A. Micchelli on his 60th birthday
Mathematics subject classifications (2000) 68T05, 68T10, 68Q32, 62M20.
Tomaso Poggio: Corresponding author. 相似文献
998.
Acta Physica Hungarica A) Heavy Ion Physics - In this paper a solution corresponding to a static spherically symmetric anisotropic fluid distribution in presence of electromagnetic field is... 相似文献
999.
N. J. Ncapayi S. M. Mullins M. Benatar E. Gueorgueiva J. J. Lawrie G. K. Mabala S. Mukherjee S. H. T. Murray K. P. Mutshena R. T. Newman J. F. Sharpey-Schafer F. D. Smit P. Vymers 《The European Physical Journal A - Hadrons and Nuclei》2005,23(2):265-269
Excited states in 175Yb, 176Yb and 177Yb were populated via the bombardment of a 176Yb target with a 750 MeV 136Xe beam. Gamma-ray decays from these states were measured with the AFRODITE multi-detector spectrometer. The rotational band
previously assigned to the ground state of 177Yb has been reassigned to the first-excited state of 175Yb. A new rotational band based on the ground state of 177Yb is presented, and the band based on the Kπ = 4- two-quasiparticle state in 176Yb has been identified. Also a candidate for the rotational band based on the Kπ = 8-, T1/2 = 11.4(3) s two-quasiparticle state in 176Yb has been found. Comparisons of gK values derived from in-band branching ratios are consistent with the ν9/2+[624] assignment to the ground state of 177Yb, the ν2{9/2+[624] ⊗ 1/2-[510]} assignment to the Kπ = 4- state and with the ν2{9/2+[624] ⊗ 7/2-[514]} assignment to the Kπ = 8- metastable excited state in 176Yb. 相似文献
1000.