一维线性非共轭石墨烯基(CH2)n分子链的电子输运

一维非共轭烷烃链虽不具富电子或少电子特征,但常存在于单分子器件或多肽、蛋白质等生物分子中,对电子传输产生重要影响.为理解这类物质的电子输运特征,本研究设计了一维线性非共轭(CH2)n分子结模型,并利用密度泛函理论结合非平衡态格林函数的方法,对(CH2)n(n=1—12)线性分子链与两个石墨烯电极耦合而成的分子结进行了第...     

Point processes and multivariate extreme values

A new model for point processes is developed which assumes that the interarrival times are exponentially distributed and follow joint multivariate extreme value distributions. It is shown that such processes may arise via natural generating procedures, and that, under very weak assumptions, that they can be approximated as closely as desired by appropriate finite models.     

Jordan函数r次方Jrk（n）的均值误差项研究

设ｋ，ｒ分别是自然数和非零整数，Ｊｋ（ｎ）是Ｊｏｒｄａｎ函数．文［３］求出了和式∑ｎ≤ｘＪｒｋ（ｎ）的渐近公式．以Ｅ（ｘ；ｋ，ｒ）表示该公式中的误差项，本文研究了Ｅ（ｘ；ｋ，ｒ）的算术均值和积分均值     

Lagrange乘数法与规划问题

本文运用Ｌａｇｒａｎｇｅ乘数法论证了线性规划问题中的对偶定理与“悖论”现象，并分析了为什么不用此方法解线性规划问题。     

Magnetic properties of the low dimensional spin system (VO)PO:ESR and susceptibility

Experimental results on magnetic resonance (ESR) and magnetic susceptibility are given for single crystalline (VO)₂P₂O₇. The crystal growth procedure is briefly discussed. The susceptibility is interpreted numerically using a model with alternating spin chains. We determine J =51 K and . Furthermore we find a spin gap of meV from our ESR measurements. Using elastic constants no indication of a phase transition forcing the dimerization is seen below 300 K. Received: 22 December 1997 / Accepted: 17 March 1998     

A note on Cesàro-Orlicz sequence spaces

The condition δ₂ in Cesàro-Orlicz sequence spaces equipped with the Luxemburg norm is discussed. The comparison theorem for these spaces is presented. Some counterexamples are provided.     

Existence results for dynamic adhesive contact of a rod

The existence and uniqueness of the weak solution to the model for the dynamics of a viscoelastic rod which is in adhesive contact with an obstacle is established. The model consists of a hyperbolic equation for the vibrations of the rod coupled with a nonlinear ordinary differential equation (ODE) for the evolution of the bonding function. The model allows for failure, i.e., complete debonding, in finite time. The existence of the weak solution is established by using an existence result for ODEs and the Schauder fixed-point theorem. The limit of an elastic rod when the viscosity vanishes is studied, too.     

Uniqueness of meromorphic functions whose derivatives share four small functions

In this paper, we will prove some uniqueness theorems of meromorphic functions whose derivatives share four distinct small functions. The results in this paper improve those given by R. Nevanlinna, L. Yang, G.D. Qiu, and other authors. An example is provided to show that the results in this paper are best possible.     

Permutable entire functions satisfying algebraic differential equations

In this paper we characterize the relation between two entire functions which are permutable and satisfy certain algebraic differential equations.     

Poincaré like inequalities for semigroups, cosine and sine operator functions

Here we present Poincaré type general L _p inequalities regarding semigroups, cosine and sine operator functions.