A first-principles study of dihydroazulene as a possible optical molecular switch

By applying nonequilibrium Green’s function formalism combined with first-principles density functional theory, we investigate the electronic transport properties of the dihydroazulene optical molecular switch. Three kinds of adsorption sites including the hollow, bridge and top sites are studied. The two forms of this molecule, namely the open form and the closed form, can reversibly switch from each other upon photoexcitation. Their transmission spectra are remarkably distinctive. Theoretical results show...     

An Analogue of Beurling’s Theorem for NA Groups

In this paper, we prove Beurling’s theorem for NA groups, from which we derive some other versions of uncertainty principles.     

Green’s function for T-stress of semi-infinite plane crack

Green’s function for the T-stress near a crack tip is addressed with an analytic function method for a semi-infinite crack lying in an elastical, isotropic, and infinite plate. The cracked plate is loaded by a single inclined concentrated force at an interior point. The complex potentials are obtained based on a superposition principle, which provide the solutions to the plane problems of elasticity. The regular parts of the potentials are extracted in an asymptotic analysis. Based on the regular parts, Gre...     

ONSET CONDITION OF STRAIN LOCALIZATION IN MATRIX OF SATURATED POROUS MEDIA

Introduction Strainlocalizationofgeomaterialsisoneofmostpopularfailuretypesinnature,which canbeshowedaslandslidesandmudflowsinmountainousareasunderincessantorheavy raining,especiallythevegetationisseverelydamagedbywoodsharvest;pipingeffect,a typeoflocalfa…     

气液两相流泄漏扩散的数值模拟

采用Eulerian-Lagrangian方法数值模拟过热液体丙烷从喷嘴释放后射流的发展过程。其中,对丙烷蒸汽与空气的气相混合物采用欧拉法求解,利用拉格朗日法跟踪丙烷液滴的运动轨迹,并加入颗粒随机轨道模型来考虑液滴的湍流扩散效应,数值计算所得的物理参量与实验测量结果相吻合。在此基础上,本文将此数值模型和方法应用于开放空间、常温高压下储存液化气(丙烷)的容器发生小孔泄漏时,两相射流在大气中的扩散过程,计算结果符合实际情况。文中还讨论了影响两相流扩散过程的主要因素,为预测可能发生的火灾爆炸事故提供理论依据。     

GIBBS-APPELL’S EQUATIONS OF VARIABLE MASS NONLINEAR NONHOLONOMIC MECHANICAL SYSTEMS

In this paper,the Gibbs-Appell’s equations of motion are extended to the most generalvariable mass nonholonomic mechanical systems.Then the Gibbs-Appell’s equations ofmotion in terms of generalized coordinates or quasi-coordinates and an integral variationalprinciple of variable mass nonlinear nonholonomic mechanical systems are obtained.Finally,an example is given.     

AN APPLICATION OF SCHAUDER’S FIXED POINT THEOREM TO THEEXISTENCE OF SOLUTlONS OF IMPULSIVELYDIFFERENTIAL EQUATIONS

In this paper the existence of solutions of a boundary value problem forimpulsively differential equations that is difficult to solve by the upper and lowersolution method will be proved by means of Schauder’s fixed point theorem,whichimproves some existing results.     

Investigation of the dynamic behavior of two collinear anti-plane shear cracks in a piezoelectric layer bonded to two half spaces by a new method

The dynamic behavior of two collinear anti-plane shear cracks in a piezoelectric layer bonded to two half spaces subjected to the harmonic waves is investigated by a new method. The cracks are parallel to the interfaces in the mid-plane of the piezoelectric layer. By using the Fourier transform, the problem can be solved with two pairs of triple integral equations. These equations are solved by using Schmidt’s method. This process is quite different from that adopted previously. Numerical examples are provided to show the effect of the geometry of cracks, the frequency of the incident wave, the thickness of the piezoelectric layer and the constants of the materials upon the dynamic stress intensity factor of cracks.     

利用Newton多项式求解结构动力响应的新方法

 提出了一种求解线性、确定性系统动力响应的新方法, 和现在 常用的逐步积分法相比，本文方法不但具有较高的计算精度，避免了 收敛性和稳定性的问题，而且大大减少了计算工作量.