全文获取类型
收费全文 | 1902篇 |
免费 | 286篇 |
国内免费 | 281篇 |
专业分类
化学 | 1548篇 |
晶体学 | 26篇 |
力学 | 88篇 |
综合类 | 23篇 |
数学 | 260篇 |
物理学 | 524篇 |
出版年
2024年 | 2篇 |
2023年 | 30篇 |
2022年 | 34篇 |
2021年 | 40篇 |
2020年 | 62篇 |
2019年 | 69篇 |
2018年 | 66篇 |
2017年 | 55篇 |
2016年 | 75篇 |
2015年 | 93篇 |
2014年 | 99篇 |
2013年 | 136篇 |
2012年 | 175篇 |
2011年 | 179篇 |
2010年 | 126篇 |
2009年 | 112篇 |
2008年 | 132篇 |
2007年 | 123篇 |
2006年 | 111篇 |
2005年 | 103篇 |
2004年 | 96篇 |
2003年 | 72篇 |
2002年 | 88篇 |
2001年 | 69篇 |
2000年 | 48篇 |
1999年 | 51篇 |
1998年 | 31篇 |
1997年 | 22篇 |
1996年 | 26篇 |
1995年 | 16篇 |
1994年 | 22篇 |
1993年 | 19篇 |
1992年 | 13篇 |
1991年 | 12篇 |
1990年 | 11篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 8篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1977年 | 1篇 |
排序方式: 共有2469条查询结果,搜索用时 78 毫秒
991.
On the <Emphasis Type="Italic">L</Emphasis><Superscript><Emphasis Type="Italic">p</Emphasis></Superscript>-consistency of wavelet estimators 下载免费PDF全文
This paper deals with the L p -consistency of wavelet estimators for a density function based on size-biased random samples. More precisely, we firstly show the L p -consistency of wavelet estimators for independent and identically distributed random vectors in R d . Then a similar result is obtained for negatively associated samples under the additional assumptions d = 1 and the monotonicity of the weight function. 相似文献
992.
993.
Lian R. Hutchings Jonathon M. Dodds Susan J. Roberts-Bleming 《Macromolecular Symposia》2006,240(1):56-67
We describe here a new strategy for the synthesis of polymers with highly branched architectures. The strategy involves the synthesis by anionic polymerization of well-defined AB2 polystyrene macromonomers with molecular weights from 3,600 to 94,000 gmol−1, which are then converted via a one-pot polycondensation reaction into high molecular weight, long-chain (hyper)branched architectures. Since the Hyperbranched structures are built up from condensation Macromonomers we have coined the term ‘HyperMac’ to describe these branched polymers. In this paper we report the synthesis of the HyperMacs, the optimal conditions for the polycondensation reaction and some preliminary characterization studies. 相似文献
994.
This paper presents a method for analyzing both linear and nonlinear seismic responses of multistoreyed buildings composed of nonorthogonal structural members under the action of bi-directional horizontal earthquake waves. Different kinds of restoring force model are used. An efficient computer programme for the computation of nonlinear seismic response of the structure was worked out. In order to illustrate the application of this method, an example of a ten-storeyed building of such sort is given. 相似文献
995.
Summary: A novel poly(p‐phenylene vinylene) (PPV)/poly(p‐phenylene ethynylene) (PPE) block‐copolymer was synthesized by a cross‐coupling polycondensation with Pd(PPh3)2Cl2 and a phase‐transfer catalyst, and was confirmed by 1H NMR and IR spectroscopy and elemental analysis. The thermal, electrochemical, and photoluminescent properties of the new copolymer have been investigated. The incorporation of triple bonds into the cyano‐substituted PPV (CN‐PPV) backbone leads to higher oxidation and reduction potentials than poly(2‐methoxy‐5‐(2‐ethylhexyloxy)‐p‐phenylene vinylene) (MEH‐PPV) and CN‐PPV, potentially making the copolymer a good electron‐transporting material for use in a light‐emitting‐diode device.
996.
997.
998.
Incompressible multiphase flow and encapsulation simulations using the moment‐of‐fluid method 下载免费PDF全文
Guibo Li Yongsheng Lian Yisen Guo Matthew Jemison Mark Sussman Trevor Helms Marco Arienti 《国际流体数值方法杂志》2015,79(9):456-490
A moment‐of‐fluid method is presented for computing solutions to incompressible multiphase flows in which the number of materials can be greater than two. In this work, the multimaterial moment‐of‐fluid interface representation technique is applied to simulating surface tension effects at points where three materials meet. The advection terms are solved using a directionally split cell integrated semi‐Lagrangian algorithm, and the projection method is used to evaluate the pressure gradient force term. The underlying computational grid is a dynamic block‐structured adaptive grid. The new method is applied to multiphase problems illustrating contact‐line dynamics, triple junctions, and encapsulation in order to demonstrate its capabilities. Examples are given in two‐dimensional, three‐dimensional axisymmetric (R–Z), and three‐dimensional (X–Y–Z) coordinate systems. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
999.
1000.
Caixia An Xilan Feng Ning Zhao Ping Liu Tianxi Wang Zhaoxun Lian 《Journal of Cluster Science》2015,26(3):889-900