On the well-posedness of the Degasperis-Procesi equation

We investigate well-posedness in classes of discontinuous functions for the nonlinear and third order dispersive Degasperis-Procesi equation

(DP)     

Explicit solutions of the (2 + 1)-dimensional AKNS shallow water wave equation with variable coefficients

Using an improved direct reduction method, we find the equivalence transformations of (2 + 1)-dimensional AKNS shallow water wave equation with variable coefficients, and obtain the corresponding relationship between explicit solutions of AKNS equation and those of the corresponding reduced equation. In addition, we get some new explicit solutions of AKNS equation by applying Lie symmetry method.     

Potential method applied to Boussinesq equation

In this paper a solution of the nonlinear Boussinesq equation is presented using the potential similarity transformation method. The equation is first written in a conserved form, a potential function is then assumed reducing it to a system of equations which is further solved through the group transformation method. New transformations are found.     

On the non-classical mathematical models of coupled problems of thermo-elasticity for multi-layer shallow shells with initial imperfections

Mathematical modeling of evolutionary states of non-homogeneous multi-layer shallow shells with orthotropic initial imperfections belongs to one of the most important and necessary steps while constructing numerous technical devices, as well as aviation and ship structural members. In first part of the paper fundamental hypotheses are formulated which allow us to derive Hamilton–Ostrogradsky equations. The latter yield equations governing shell behavior within the applied hypotheses and modified Pelekh–Sheremetev conditions. The aim of second part of the paper is to formulate fundamental hypotheses in order to construct coupled boundary problems of thermo-elasticity which are used in non-classical mathematical models for multi-layer shallow shells with initial imperfections. In addition, a coupled problem for multi-layer shell taking into account a 3D heat transfer equation is formulated. Third part of the paper introduces necessary phase spaces for the second boundary value problem for evolutionary equations, defining the coupled problem of thermo-elasticity for a simply supported shallow shell. The theorem regarding uniqueness of the mentioned boundary value problem is proved. It is also proved that the approximate solution regarding the second boundary value problem defining condition for the thermo-mechanical evolution for rectangular shallow homogeneous and isotropic shells can be found using the Bubnov–Galerkin method.     

Hydration in drug design. 2. Influence of local site surface shape on water binding

Summary If water molecules are strongly bound at a protein-ligand interface, they are unlikely to be displaced during ligand binding. Such water molecules can change the shape of the ligand binding site and thus affect strategies for drug design. To understand the nature of water binding, and factors influencing it, water molecules at the ligand binding sites of 26 high-resolution protein-ligand complexes have been examined here. Water molecules bound in deep grooves and cavities between the protein and the ligand are located in the indentations on the protein-site surface, but not in the indentations on the ligand surface. The majority of the water molecules bound in deep indentations on the protein-site surface make multiple polar contacts with the protein surface. This may indicate a strong binding of water molecules in deep indentations on protein-site surfaces. The local shape of the site surface may influence the binding of water molecules that mediate protein-ligand interactions.     

BPR树脂对Au(Ⅰ)、Ag(Ⅰ)等氰合离子的离子交换与吸附研究(Ⅱ)——内扩散系数的测定及传质过程研究

测定了不同温度下Au(Ⅰ)、Ag(Ⅰ)、Ni(Ⅱ)、Cu(Ⅰ)、Fe(Ⅲ)氰合离子在Cl、NO₃、OH型BPR树脂中的内扩散系数和扩散活化能,BPR树脂提取Au(Ⅰ)、Ag(Ⅰ)等氰合离子的机理为离子交换过程,并求得了几种氰合离子的活化熵差值(△S-△S)。     

地面地震CT在浅层勘探中的应用

在地表面沿研究区域的四周布置激发点和检波器 ,进行人工地震观测记录。地震能量由激发点到达接收点 ,利用直达波、反射波和折射波等多震相 ,进行 CT反演 ,得到波速地震 CT图像。该图像给出浅层波速横向分布 ,反映了覆盖层分区及基底岩性特点与构造分布。该方法应用于某工程场地的浅层勘探中 ,所得波速 CT图像与地质露头及开挖相吻合。该方法将地震 CT技术从钻孔和巷道中解放出来。     

三峡库区巫山移民新城址松散堆积体成因机制研究

以巫山移民新城址松散堆积体成因类型为例 ,对三峡库区分布较广的松散堆积体进行了研究。通过对大量新开挖剖面的调查测绘 ,在许多地段发现了堆积与基岩之间的滑坡主滑带 ,说明了在该区分布较广的松散堆积体成因具有复合性。它是构造和岩溶作用前提下形成的滑坡体、崩塌体、泥石流堆积体和岩溶坍陷堆积体。运用高分辨率浅层地震勘探揭示堆积体发育深度可达 40 m至 6 0 m ,通过面波测试可按波速将之划分为三层。最后 ,建立了松散堆积体形成演化的概念模型 ,并运用目前最新版本的离散元软件 (UDEC3.0 )对其中最为重要的一种类型滑崩堆积体的形成演化过程进行了模拟。结果表明 ,该区的层状岩体在长江河流下切过程中 ,形成了区域性的卸荷松动 ,而在岩体下部形成压碎张裂带 ;地下水沿卸荷拉裂带渗入 ,并与压裂带贯通 ,形成了岩溶发育带 ,为滑坡、崩塌、塌陷等表生改造提供了条件。     

浅水声速剖面用经验正交函数(EOF)表示的可行性研究

本文研究利用经验正交函数（Ｅ０Ｆ）及少量参数以近似表示实测浅水声速剖面的方法,研究了样本数,不同浅水域的样杜和算法的关系,并得出结论：一定区域的浅水声速剖面,以经验正交函数（Ｅ０Ｆ）近似表示,仍可以达到较好的精度,这对于声场层析及被动定位总理２有着很重要的意义。