全文获取类型
收费全文 | 595954篇 |
免费 | 7118篇 |
国内免费 | 2007篇 |
专业分类
化学 | 320635篇 |
晶体学 | 8902篇 |
力学 | 27392篇 |
综合类 | 23篇 |
数学 | 69935篇 |
物理学 | 178192篇 |
出版年
2020年 | 4608篇 |
2019年 | 5142篇 |
2018年 | 6216篇 |
2017年 | 6141篇 |
2016年 | 9878篇 |
2015年 | 6648篇 |
2014年 | 10026篇 |
2013年 | 26490篇 |
2012年 | 20521篇 |
2011年 | 25158篇 |
2010年 | 17116篇 |
2009年 | 17340篇 |
2008年 | 23314篇 |
2007年 | 23565篇 |
2006年 | 22100篇 |
2005年 | 19991篇 |
2004年 | 18261篇 |
2003年 | 16314篇 |
2002年 | 16131篇 |
2001年 | 17834篇 |
2000年 | 13699篇 |
1999年 | 10658篇 |
1998年 | 8716篇 |
1997年 | 8639篇 |
1996年 | 8479篇 |
1995年 | 7647篇 |
1994年 | 7414篇 |
1993年 | 7070篇 |
1992年 | 7951篇 |
1991年 | 7964篇 |
1990年 | 7448篇 |
1989年 | 7406篇 |
1988年 | 7573篇 |
1987年 | 7220篇 |
1986年 | 6945篇 |
1985年 | 9662篇 |
1984年 | 9756篇 |
1983年 | 8047篇 |
1982年 | 8447篇 |
1981年 | 8323篇 |
1980年 | 7977篇 |
1979年 | 8371篇 |
1978年 | 8426篇 |
1977年 | 8580篇 |
1976年 | 8481篇 |
1975年 | 8168篇 |
1974年 | 7906篇 |
1973年 | 8222篇 |
1972年 | 5347篇 |
1971年 | 4269篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
991.
This paper presents an evaluation of the capability of turbulence models available in the commercial CFD code FLUENT 6.0 for their application to hydrofoil turbulent boundary layer separation flow at high Reynolds numbers. Four widely applied two‐equation RANS turbulence models were assessed through comparison with experimental data at Reynolds numbers of 8.284×106 and 1.657×107. They were the standard k–εmodel, the realizable k–εmodel, the standard k–ωmodel and the shear‐stress‐transport (SST) k–ωmodel. It has found that the realizable k–εturbulence model used with enhanced wall functions and near‐wall modelling techniques, consistently provides superior performance in predicting the flow characteristics around the hydrofoil. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
992.
K.B. Welter Q. Wu Y. You K. Abel D. McCreary S.M. Bajorek J.N. Reyes Jr 《International Journal of Multiphase Flow》2004,30(12):407-1484
This article describes a comprehensive literature review of liquid entrainment in horizontal pipes with vertical-up branches. Deficiencies in the available data and correlations were identified. The Air–water Test Loop for Advanced Thermal–hydraulic Studies (ATLATS) was constructed and entrainment onset and steady-state data were collected for a wide range of flow conditions. Using new insights gained from experimental testing, the authors developed a model for predicting the onset of entrainment and steady-state entrainment rate. Previously published correlations, along with the new model, are compared against all available data. The new model shows very good agreement with the onset data, but is not very good at predicting branch quality at high liquid flow rates. 相似文献
993.
994.
995.
The natural modes of a discrete linear system are orthogonal with respect to the mass and stiffness matrices in a generalized sense. However, these modes are usually not orthogonal to each other in the ordinary sense. The purpose of this paper is to document a number of conditions under which the modes are also orthogonal in an ordinary fashion. 相似文献
996.
An experimental method is developed to examine the near tip deformation at the mesoscopic scale level. The differential interference contrast (DIC) method is used by application of the Nomarski prism in polarized microscope for measuring the out of surface deformation. The method is very sensitive to small height changes detected by different interference color. Discussed are results for the crack tip deformation field. 相似文献
997.
998.
999.
Kerstin Paech Adrian Dumitru Jürgen Schaffner-Bielich Stefan Schramm Horst Stöcker Gebhard Zeeb Detlef Zschiesche 《Acta Physica Hungarica A》2004,21(2-4):151-156
The measured particle ratios in central heavy-ion collisions are investigated within a chemical and thermal equilibrium chiral SU(3) σ?ω approach. Contrary to the commonly adopted non-interacting gas calculations, the chiral SU(3) model predicts modified effective hadron masses and effective chemical potentials in the medium and a transition to a chirally restored phase at high temperatures or chemical potentials. the influence of three different types of phase transitions is investigated. We show that the deduced freeze-out values considerably depend on the underlying model while the quality of the fit is approximately the same. 相似文献
1000.