伊犁谷地野核桃林下土壤的形成特点及其系统分类

伊犁谷地野核桃林下的土壤有均腐殖质性，Ｒｈ０．３１￣０．３９，腐殖质组成以胡敏酸为主，Ｅ４值较高，弱粘化，钙积现象，Ｂａ值较高，粘土矿物以伊利石，蛭石，蒙脱石为主，淋溶较弱，风化程度不高，四个研究剖面分类为均腐土纲，干润均腐土亚纲，粘化干润均腐土类，钙积干润均腐土类，简育干润均腐土类，根据暗沃表层的厚度，划分相关的亚种。     

The effect of a single vortex generator jet on the characteristics of a turbulent boundary layer

A flat plate experiment was performed in a water tunnel to determine the effects of a vortex generator jet on the characteristics of a turbulent boundary layer at various wall normal locations. The results show that the characteristic distributions of the turbulent fluctuation quantities are nearly unaffected by the induced vortex structures neither in the steady nor in the dynamic blowing case. The shear layer interaction between the turbulent main flow and the jet flow produces less turbulent fluctuations than it is expected from a turbulent free jet flow. Thus, the mixing process of this flow control strategy is based only on a large-scale momentum transport superimposed by the turbulent fluctuation quantities. This allows a separation of scales for physical interpretation and numerical simulations.     

昆明西郊行道绿化植物五种有毒重金属元素含量特下分析

对昆明西郊行道绿化植物“五毒”重金属元素含量特征进行了分析，结果显示，在地道绿化植物中，元素含量的相对离散度为Ｃｄ〉Ａｓ〉Ｈｇ〉Ｃｒ〉Ｐｂ，与含量变化顺序不匹配，元素间仅Ｐｂ与Ｃｒ呈现十分正相关。     

含弥散核废料污染问题特征有限元方法

研究可压缩核废料污染问题，考虑包含分子扩散和弥散的一般情形．从问题的原始数学模型出发，构造了特征线有限元全离散格式．对通常使用的构造误差方程的方法进行了改进，证明了格式的最佳L∞（J；H1（Ω））收敛性．     

Pictet-Spengler酶及其相关生物学特性

Pictet-Spengler(P-S)反应在合成异唪啉和β-咔啉衍生物的过程中起着重要作用,它作为多种生物碱合成过程中最基础的一步反应,近年来受到人们广泛的关注.在新形成的杂环体系中,P-S反应催化醛基碳原子形成为新的手性中心.简单P-S反应得到的是外消旋混合物,但具有重要生物活性的物质通常具有立体专一性,因此寻找能...     

The Generalized Nonlinear Galerkin Method Applied to Hydrodynamics of the Open Sea

In this paper we present new numerical algorithms based on a generalized nonlinear Galerkin method in order to solve coastal and oceanic circulation problems. The equations system is based on the primitive equations of the ocean under Boussinesq and hydrostatic approximations. These equations are transformed using, at the same time, the classical σ transformation and an original homogenization of the boundary conditions. We use a well adapted special basis to apply the usual Galerkin method and the nonlinear Galerkin method. This basis is built on a modelization of the energetic transfers through the different scales of flow. Two approaches are proposed to solve the continuity equation: the (nonlinear) Galerkin method and the method of the characteristics. We present the advantages and drawbacks of both methods.     

不同结构光子晶体的带隙特性

基于平面波展开法研究光子晶体的带隙特性,数值模拟了横磁波和横电波在三角晶格和正方晶格构成的二维光子晶体中的带隙特性,得到了三角晶格较正方晶格更容易出现带隙,且三角晶格的横电波光子带隙较大.实验结果为光子晶体器件的设计提供理论依据.     

特征光谱法研究贵州两类不同香型风格烟叶

利用三维荧光和紫外-可见吸收光谱对贵州典型植烟区烤烟石油醚提取液进行光谱测定,获得烟叶化学物质总体特征光谱信息。光谱总体相似,但强度存在差异。三维荧光光谱中观察到三个特征峰,分别为峰Ⅰ:Ex/Em=297/326nm,峰Ⅱ:Ex/Em=250/330nm,峰Ⅲ:Ex/Em=225/336nm。峰强度表现为峰Ⅰ峰Ⅲ峰Ⅱ;紫外-可见吸收光谱在300~500nm波段呈现4个特征吸收峰,最大吸收波长λmax分别为329,419,445和472nm。根据三维荧光及紫外-可见吸收光谱特征峰的相对强度得到表征不同香型风格烟叶的总体化学物质相对含量的差异。利用三维荧光强度分数(D)及强度比值(R)的光谱数据进行聚类分析,在一定的距离系数范围内,能清晰划分贵州典型区域的"清甜香"和"醇甜香"两类特征香型烤烟。用荧光强度比值聚类较强度分数聚类更能在较小的距离系数内实现分类;三维荧光法较紫外-可见光谱法聚类的特征性更好。     

分析光纤特性的新颖方法

本文从波动理论出发,引入用于分析微波传输线的方法-二维CC-FD-TD方法对光纤的色散特性进行研究。并利用电磁场的叠加原理对分析光纤时在圆心处出现的奇点进行了处理,最后利用计算例证明这一方法的可行性。     

Utilization of the method of characteristics to solve accurately two-dimensional transport problems by finite elements

A new finite element method is presented for the solution of two-dimensional transport problems. The method is based on a weighted residual formulation in which the method of characteristics is combined with the finite element method. This is achieved by orienting sides of the space-time elements joining the nodes at subsequent time levels along the characteristics of the pure advection equation associated with the transport problem. The method is capable of solving numerically the advection--diffusion equation without generating oscillations or numerical diffusion for the whole spectrum of dispersion from diffusion only through mixed dispersion to pure convection. The utility and accuracy of the method are demonstrated by a number of examples in two space dimensions and a comparison of the numerical results with the exact solution is presented in one case. A very favourable feature of the method is the capability of solving accurately advection dominated transport problems with very large time steps for which the Courant number is well over one.