全文获取类型
收费全文 | 59篇 |
免费 | 10篇 |
国内免费 | 5篇 |
专业分类
化学 | 12篇 |
数学 | 41篇 |
物理学 | 12篇 |
无线电 | 9篇 |
出版年
2022年 | 6篇 |
2021年 | 4篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 6篇 |
2013年 | 9篇 |
2012年 | 5篇 |
2011年 | 5篇 |
2010年 | 4篇 |
2009年 | 3篇 |
2008年 | 1篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 6篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1988年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有74条查询结果,搜索用时 10 毫秒
11.
Constantine M. Dafermos 《偏微分方程通讯》2013,38(7):1274-1286
Physically admissible, global BV solutions are constructed to the Cauchy problem for the equations of one-dimensional, nonlinear viscoelasticity of the Boltzmann type. The required BV bounds are derived with the help of energy estimates, in conjunction with a change of variables that redistributes the damping on an equitable basis among the equations of the system, thus exposing the dissipative effect of viscosity on the variation of solutions. 相似文献
12.
Given a simple, simply laced, complex Lie algebra
corresponding to the Lie group G, let
be thesubalgebra generated by the positive roots. In this Letter we construct aBV algebra
BV}}[\mathfrak{g}]$$
" align="middle" border="0">
whose underlying graded commutative algebra is given by the cohomology, with respect to
, of the algebra of regular functions on G with values in
. We conjecture that
BV}}[\mathfrak{g}]$$
" align="middle" border="0">
describes the algebra of allphysical (i.e., BRST invariant) operators of the noncritical
string. The conjecture is verified in the two explicitly known cases,
2 (the Virasoro string) and
3 (the
string). 相似文献
13.
We show that a planar BV homeomorphism can be approximated in the area strict sense, together with its inverse, with smooth or piecewise affine homeomorphisms. 相似文献
14.
15.
16.
The aim of this paper is to get the decomposition of distributional derivatives of functions with bounded variation in the framework of Carnot-Caratheodory spaces (C-C spaces in brievity) in which the vector fields are of Carnot type. For this purpose the approximate continuity of BV functions is discussed first, then approximate differentials of L1 functions are defined in the case that vector fields are of Carnot type and finally the 相似文献
17.
We consider a continuum-discrete model for supply chains based on partial differential equations. The state space is formed by a graph: The load dynamics obeys to a continuous evolution on each arc, while at nodes the good density is conserved, while the processing rate is adjusted. To uniquely determine the dynamics at nodes, the through flux is maximized, with the minimal possible processing rate change. Existence of solutions to Cauchy problems is proven. The latter is achieved deriving estimates on the total variation of the density flux, density and processing rate along a wave-front tracking approximate solution. Then the extension to supply networks is showed. 相似文献
18.
David E. Dobbs 《Rendiconti del Circolo Matematico di Palermo》2003,52(2):281-284
SoientA ⊆B des anneaux (commutaifs et unitaires). On dit que (A,B) est une paire d’anneaux de going-down siD est un anneau de going-down pour tout anneauD tel queA ⊆D ⊆B. On preuve que (A,B) est une paire d’anneaux de going-down si et seulement siA[b
1,b
2] est un anneau de going-down pour toutb
1,b
2 εB. 相似文献
19.
Plant-derived products have been used since the beginnings of human history to treat various pathological conditions. Practical experience as well as a growing body of research suggests the benefits of the use of turmeric (Curcuma longa) and some of its active components in the reduction of oxidative stress, a mechanism leading to neurodegeneration. In this current study, we investigated the effects of a preparation of Curcuma longa, and its constituents curcumin, tetrahydrocurcumin, and curcumenol, in one of the molecular pathways leading to oxidative stress, which is the release of NO, a free radical involved in stress conditions, using the BV2 microglial cell line. The concentration-dependent reduction of NO is linked to reduced amounts of iNOS protein- and mRNA-synthesis and is possibly mediated by the phosphorylation of mitogen-activated protein kinases (MAPK) such as p42/44 or p38 MAPK. Therefore, the use of turmeric extract is a promising therapeutic option for diseases linked to the dysregulation of oxidative stress, with fewer side-effects in comparison to the currently used pharmacotherapeutics. 相似文献
20.
§ 1.Introduction In this paper,we study the asymptotic behavior of minimizers{ uε} ε>0 (ε→ 0 ) of thevariational probleminf∫Ω[εp- 1 | Du| p + 1εW(x,u) ] dx:u∈ W1 ,p(Ω ) ,u =g,x∈ Ω (Pε)where p>1 ,N≥ 2 ,andΩ RN is a bounded open domain with Ω∈C2 . This kind of problems comes from the theory of phase transitions and are widelystudied in recent years.In [1 ]— [1 4] ,the authors investigated these problems underthe integral constraint∫Ωudx =constant,In [1 5]— [1 6] ,… 相似文献