在白噪声分析中的广义维里拉普拉斯

一类广义维里拉普拉斯，把在白噪声分析构架中通常定义的维里拉普拉斯作为特殊情形而包含。     

浅海温跃层声散射实验研究

本文给出１９８８、１９８９和１９９２年夏季南黄海海域三站位（水深３４米、４４米和３９米）处的温跃层声脉冲反向散射实验结果。实验用窄带脉冲声源的中心频率分别为１２０ｋＨｚ、１６０ｋＨｚ和２００ｋＨｚ。实验过程中同时用ＣＴＤ仪昼夜分段记录温、盐、深参数和分层拖网采集浮游生物样本。作者根据Ｒ．Ｋｉｎｄ关于平面波在任意分布不均匀层系上反射系数谱的计算方法，求出以实测温、盐垂直分布构成的不均匀层系上反射系数谱，得到跃层散射在时域上的数值模拟散射信号，与海上实测记录在时域和幅度进行对比。三年同期重复实验结果表明：实测跃层散射波到达接收点的时间与按温度剖面所做数值模拟计算结果相符。浮游生物样品分析数据与声信号记录看不出确定的对应关系，说明声散射主要是海水介质的物理不均匀性引起。     

Some Results on Evolutionary Equations Involving Functions of the Curvatures of the Graph

51.Introducti0nandMainResultlnthepaperL1J,Caffarelli,NirenbergandSpruckdiscussedtheDirichletproblemforthenonlinearellipticequationforunknownu=u(x):{':<;;>:,<";>:are,vxeD,(1-1)where0lsab0undedstrictlyconvexdomaininR"withsmoothboundaryare,K(u)=(K,(u),Kz(u),..',K"(u))denotestheprincipalcurvaturesofthegraph(x,u(x))andfisofaspecialnatureasinL2J'L3j.Typicalcasesoftheequationin(1.l),whichweretreatedaswellbyIvochkina[4J,isf=Sl/*(K),whereS*(K)arethee1ementarysymmetricfunctions,Recently,Ivochki…     

A SECOND-ORDER PERIODIC BOUNDARY VALUE PROBLEM WITH SINGULAR AND DISCONTINUOUS NONLINEARITY

1. Introduction and Main ResultsIn recent years, singular nonlinear two-point boundary value problems have been studied. For details, see, for instance, [1--14] and references therein. However, the periodicboundary problems with singlllar and discontinuous nonlinearity are quite rarely studied.Motivated by [12,14], we study in this paper a periodic boundary value problem with singularand discontinuous nonlinearity of the form{;<;';<2;::<'> =:<u:>::<,.>,, 5 t 5 27, (1 1)where p is a positi…     

Synthesis and structural characterization of Znb3Nb2 powder

Science China Physics, Mechanics & Astronomy - Zinc nitride (Znb3Nb2) powder has been synthesized through the nitridation reaction of Zn powder with NH3 gas (at the flow rate of 500 ml/min) at...     

Karman vortex street assisted patterning in the growth of silicon nanowires

A Karman vortex street was employed to pattern catalysts and grow nanomaterial arrays, which were made of a disk-like superstructure built of silicon nanowires; there also existed nanowires connected with the disks.     

The Cauchy Problem of the Porous Medium Equation with Absorption

In this paper we study the existence of solution for the following Cauchy problem {u_t = Δu^m - u^p u(x,0) = u_0(x) We show how the growth condition of initial trace is determined by the absorption.     

Some Results on Evolutionary Equations Involving Functions of the Eigenvalues of the Hessian

How to design the parabolic counterpart of the nonlinear elliptic equation involving function of the eigenvalues of the Hessian is discussed and the first initial-boundary value problem for such a parabolic equation is studied.     

Characterization of ZnO nanorods grown on Si substrates coated with NiCl2

ZnO nanorods were synthesized on NiCl₂‐coated Si substrates via a chemical vapor deposition (CVD) process. The as‐fabricated nanorods with diameters ranging from 150 nm to 200 nm and lengths up to several tens of micrometers grew preferentially arranged along [0001] direction, perpendicular to the (0002) plane. The clear lattice fringes in HRTEM image demonstrated the growth of good quality hexagonal single‐crystalline ZnO. Room temperature photoluminescence (PL) spectra illustrated that the ZnO nanorods exhibit strong UV emission peak and green emission peak, peak centers located at 388 nm and 506 nm. A possible growth mechanism based on the study of our X‐ray diffraction (XRD), electron microscopy and PL spectroscopy was proposed, emphasizing the effect of NiCl₂ solution (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Periodic boundary value problem of functional differential equations with perturbation

By coincidence degree, the existence of solution to the periodic boundary value problem of functional differential equations with perturbation