全文获取类型
收费全文 | 74篇 |
免费 | 2篇 |
专业分类
化学 | 27篇 |
力学 | 7篇 |
综合类 | 1篇 |
数学 | 14篇 |
物理学 | 27篇 |
出版年
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 6篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 1篇 |
2014年 | 6篇 |
2013年 | 4篇 |
2012年 | 1篇 |
2011年 | 2篇 |
2010年 | 2篇 |
2009年 | 2篇 |
2008年 | 3篇 |
2007年 | 4篇 |
2005年 | 3篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2000年 | 1篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有76条查询结果,搜索用时 649 毫秒
1.
We investigate IV-characteristics of coupled Josephson junctions which model the intrinsic Josephson junctions in high temperature superconductors under external electromagnetic radiation. A staircase structure of Shapiro steps is found in the branching region. Its origin is related to the coupling between junctions and their switching from rotating to oscillating states. This conclusion is tested by detailed analysis of the IV-characteristics as for total stack and for each junction in the stack. IV-curves of junctions in the stack are compared with the average of time derivative of phase difference. Experimental observation of this staircase structure would give us a proof of coupling between junctions and a way for precise measurement of its value. Such investigations would be also useful for a diagnostic of Josephson junctions in the stack. 相似文献
2.
Mohammad Nasser H. EL-Sherbiny Gamal M. Hammad Ali A. Askar Ahmed A. El- Nour Salwa A. Abou 《Cellulose (London, England)》2022,29(3):1791-1805
Cellulose - Antibacterial coatings based on bacterial cellulose (BC) have been widely used in many fields including food packaging and wound dressing. In this study, we aimed to synthesis of... 相似文献
3.
A method is presented for obtaining periodic solutions to forced oscillations of non-linear systems governed by equations of the form uss?uyy?εf(u,u,y,uyy…,s) = 0. The method is presented by application to the equation uss?uyy?εu2yuyy= 0 which governs the vibrations of a soil layer that is free on the top surface and is forced harmonically at the bedrock. It is shown that unlike the ODE case (Duffing equation), the PDE requires an infinite number of periodicity conditions to correctly characterize the resonant region and these conditions lead to an infinite number of branches in the dispersion spectrum. Calculations indicate that these branches tend to an envelope curve. The uniform approach presented by Millmann and Keller is discussed in order to determine in what sense it can be viewed as an effective approximation for the fundamental mode. 相似文献
4.
The paper derives the relevant non-linear integro-differential evolution equation by the method due to Collins expanding on a procedure by Keller. The quadratically non-linear case is not a trivial variation over the cubically non-linear case that was presented in preceding papers. As expected a different scaling and ordering of terms is needed and the first order perturbation solution provides no information on resonance. Nevertheless, although obtained by much longer calculations, the final equation for the present case is of identical form, with differences only in numerical coefficients, with the cubic case that was presented and solved earlier. 相似文献
5.
The phase transition during chemical lithium insertion into α-MoO3 was investigated by chemical analysis, X-ray diffraction (XRD) and electrochemical characterisation. The samples have been
prepared by reaction of various amounts of water-free lithium iodide with fine-particulate orthorhombic molybdenum trioxide
in n-hexane (non-aqueous media), which yielded materials with different Li/Mo ratio. XRD investigations of these materials proved
that the crystal structure of the layered α-MoO3 has been changed after the chemical lithiation. The phase transition ranged from 0.25 < x < 0.5 in Li
x
MoO3 upon chemical lithium insertion into α-MoO3. The XRD lines of lithium inserted phase Li
x
MoO3 grew at the expense of the XRD lines of the pristine α-MoO3 as lithium ions were chemically inserted until the disappearance of lines related to α-MoO3. The electrochemical performance of the lithiated samples is improved in comparison with the starting material (non-lithiated
α-MoO3). 相似文献
6.
The effect of gravitational and inertial forces on the precision cumulation of cavities, fast mass flows, and detonation and
shock waves is studied in stages. The possible effects of these forces on the motion of masses and waves (the velocity, direction
and structure of the waves can change) and on the properties of the medium in front of the waves that influence the change
in the parameters and refraction of the waves are noted. It is shown that it is advantageous to perform precision cumulation
experiments in zero-gravity.
Zh. éksp. Teor. Fiz. 111, 2001–2015 (June 1997) 相似文献
7.
The formation of gas channels in rotating liquids is investigated and the application of such channels as capillaries for
high-power discharges in x-ray lasers, for transporting particle and radiation fluxes, and lowering breakdown thresholds (including
with the use of metal fillings), for structural systems for microwave generation and particle acceleration, and for photochemical
and shock action on a liquid, and so on, is discussed. It is noted that tubular active elements and samples can be fabricated
by solidification and crystallization during rotation.
Pis’ma Zh. éksp. Teor. Fiz. 65, No. 3, 291–294 (10 February 1997) 相似文献
8.
9.
Durdimurod Kalandarovich Durdiev Askar Ahmadovich Rahmonov 《Mathematical Methods in the Applied Sciences》2020,43(15):8776-8796
We consider a system of hyperbolic integro-differential equations of SH waves in a visco-elastic porous medium. In this work, it is assumed that the visco-elastic porous medium has weakly horizontally inhomogeneity. The direct problem is the initial-boundary problem: the initial data is equal to zero, and the Neumann-type boundary condition is specified at the half-plane boundary and is an impulse function. As additional information, the oscillation mode of the half-plane line is given. It is assumed that the unknown kernel has the form K(x,t)=K0(t)+ϵxK1(t)+…, where ϵ is a small parameter. In this work, we construct a method for finding K0,K1 up to a correction of the order of O(ϵ2). 相似文献
10.
ABSTRACTAn algebra with identities a(bc)?=?b(ac), (ab)c?=?(ac)b is called bicommutative. We construct list of identities satisfied by commutator and anti-commutator products in a free bicommutative algebra. We give criterions for elements of a free bicommutative algebra to be Lie or Jordan. 相似文献