全文获取类型
收费全文 | 121285篇 |
免费 | 7578篇 |
国内免费 | 5850篇 |
专业分类
化学 | 56012篇 |
晶体学 | 1269篇 |
力学 | 9223篇 |
综合类 | 391篇 |
数学 | 36867篇 |
物理学 | 30951篇 |
出版年
2024年 | 70篇 |
2023年 | 840篇 |
2022年 | 881篇 |
2021年 | 1431篇 |
2020年 | 1732篇 |
2019年 | 1637篇 |
2018年 | 11509篇 |
2017年 | 11237篇 |
2016年 | 7928篇 |
2015年 | 2837篇 |
2014年 | 2827篇 |
2013年 | 3501篇 |
2012年 | 7659篇 |
2011年 | 14287篇 |
2010年 | 8350篇 |
2009年 | 8629篇 |
2008年 | 9474篇 |
2007年 | 11255篇 |
2006年 | 2689篇 |
2005年 | 3334篇 |
2004年 | 3271篇 |
2003年 | 3309篇 |
2002年 | 2423篇 |
2001年 | 1403篇 |
2000年 | 1330篇 |
1999年 | 1185篇 |
1998年 | 1030篇 |
1997年 | 884篇 |
1996年 | 1018篇 |
1995年 | 804篇 |
1994年 | 698篇 |
1993年 | 639篇 |
1992年 | 541篇 |
1991年 | 465篇 |
1990年 | 396篇 |
1989年 | 311篇 |
1988年 | 295篇 |
1987年 | 270篇 |
1986年 | 207篇 |
1985年 | 214篇 |
1984年 | 185篇 |
1983年 | 160篇 |
1982年 | 123篇 |
1981年 | 105篇 |
1980年 | 98篇 |
1979年 | 85篇 |
1978年 | 66篇 |
1976年 | 44篇 |
1975年 | 48篇 |
1914年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
131.
Assisted Cloning and Orthogonal Complementing of an Arbitrary Unknown Two-Qubit Entangled State 总被引:1,自引:0,他引:1
Based on A.K. Pati‘s original idea [Phys. Rev. A 61 (2000) 022308] on single-qubit-state-assisted clone, very recently Zhan has proposed two assisted quantum cloning protocols of a special class of unknown two-qubit entangled states [Phys. Lett. A 336 (2005) 317]. In this paper we further generalize Zhan‘s protocols such that an arbitrary unknown two-qubit entangled state can be treated. 相似文献
132.
Using elementary graded automorphisms of polytopal algebras (essentially the coordinate rings of projective toric varieties)
polyhedral versions of the group of elementary matrices and the Steinberg and Milnor groups are defined. They coincide with
the usual K-theoretic groups in the special case when the polytope is a unit simplex and can be thought of as compact/polytopal substitutes
for the tame automorphism groups of polynomial algebras. Relative to the classical case, many new aspects have to be taken
into account. We describe these groups explicitly when the underlying polytope is 2-dimensional. Already this low-dimensional
case provides interesting classes of groups.
Received: 13 December 2001 / Revised version: 24 June 2002
The second author was supported by the Deutsche Forschungsgemeinschaft, INTAS grant 99-00817 and TMR grant ERB FMRX CT-97-0107
Mathematics Subject Classification (2000): 14L27, 14M25, 19C09, 52B20 相似文献
133.
王巨平 《中国科学A辑(英文版)》2002,45(7):827-835
This paper verifies the singularity conjecture for Jacobi forms with higher degree in some typical cases, and gives constructions
for the Jacobi cusp forms whose Fourier coefficients can be expressed by some kind of Rankin-typeL-series. 相似文献
134.
135.
It is explicitly shown that if phase transition occurs at the core of a newborn neutron star with moderately strong magnetic
field strength, which populates only the electron’s Landau levels, then in the β -equilibrium condition, the quark core is
energetically much more unstable than the neutron matter of identical physical condition. 相似文献
136.
137.
贝克曼Allegra^TM 21R型超高速离心机开机后,操作面板上出现错误代码“28”,离心机不旋转。离心机的电机采用无刷感应驱动,由电机驱动电源模块BSMl0GD60DN2驱动离心机的电机。故障是由于电源模块BSMl0GD60DN2损坏引起的。采用东芝三相桥式IGBT电源模块MG25Q6ES42代替BSMl0GD60DN2,并更换已烧毁的栅极电阻后。开机试验,仪器恢复正常。 相似文献
138.
For more than 25 yearsJΨ production has helped to sharpen our understanding of QCD. In proton induced reaction some observations are rather well understood
while others are still unclear. The current status of the theory ofJΨ production will be sketched, paying special attention to the issues of formation time andJΨ re-interaction in a nuclear medium. 相似文献
139.
在伽利略的运动学研究中,自由落体运动是一个重要课题.他敏锐地认识到,通过打开自由落体运动这个缺口,会导致一门新科学的诞生.他在《两门新科学》(即《关于两门新科学的数学证明的对话》)一书中写道:"我的目的,是要阐述一门崭新的科学,它研究的却是非常古老的课题.也许,在自然界中最古老的课题莫过于运动了. 相似文献
140.
During the course of our investigation of the electron transfer properties of some redox species through highly hydrophobic
long chain alkanethiol molecules on gold in aqueous and non-aqueous solvents, we obtained some intriguing results such as
unusually low interfacial capacitance, very high values of impedance and film resistance, all of which pointed to the possible
existence of a nanometer size interfacial gap between the hydrophobic monolayer and aqueous electrolyte. We explain this phenomenon
by a model for the alkanethiol monolayer—aqueous electrolyte interface, in which the extremely hydrophobic alkanethiol film
repels water molecules adjacent to it and in the process creates a shield between the monolayer film and water. This effectively
increases the overall thickness of the dielectric layer that is manifested as an abnormally low value of interfacial capacitance.
This behaviour is very much akin to the ‘drying transition’ proposed by Lum, Chandler and Weeks in their theory of length
scale dependent hydrophobicity. For small hydrophobic units consisting of apolar solutes, the water molecules can reorganize
around them without sacrificing their hydrogen bonds. Since for an extended hydrophobic unit, the existence of hydrogen bonded
water structure close to it is geometrically unfavourable, there is a net depletion of water molecules in the vicinity leading
to the possible creation of a hydrophobic interfacial gap. 相似文献