R^3中一类二次齐次向量场的拓扑结构

讨论了Ｒ３中的二次齐次向量场Ｑ（ｘ）的拓扑结构．当它只有孤立奇点时,利用向量场ＷＱ（ｘ）的相图,得到Ｑ（ｘ）的轨线共有１２种不同的拓扑等价类．     

Effect of the modification of silica on thermal properties and flammability of cross-linked butadiene-acrylonitrile rubbers

The paper presents the results of testing the thermal stability and flammability of butadiene-acrylonitrile rubber vulcanizates with different contents of combined acrylonitrile: Perbunan NT 1845 and Perbunan NT 3945 from Bayer, containing unmodified and bromine- or iodine-modified silica. The test results were obtained with the use of a derivatograph, measurements of flammability by the method of oxygen index, in air and also with the use of a cone calorimeter. The effect of the modification on the zeta potential was also examined. A considerable reduction in the flammability of nitrile rubber vulcanizates filled with silica can be obtained by the modification of filler with bromine or iodine. All the vulcanizates containing modified silica are self-extinguishing. An appropriate filling of NBR 39 vulcanizates with bromine-modified silica makes it possible to obtain non-flammable polymeric materials. They neither ignite nor glow under the action of a flame source for 30 s. The findings can be a rational basis for the synthesis of modified silica that can act as active filler and effective flame-retardant agent at the same time.     

Facets for the cut cone I

We study facets of the cut coneC _n , i.e., the cone of dimension 1/2n(n – 1) generated by the cuts of the complete graph onn vertices. Actually, the study of the facets of the cut cone is equivalent in some sense to the study of the facets of the cut polytope. We present several operations on facets and, in particular, a lifting procedure for constructing facets ofC _n+1 from given facets of the lower dimensional coneC _n . After reviewing hypermetric valid inequalities, we describe the new class of cycle inequalities and prove the facet property for several subclasses. The new class of parachute facets is developed and other known facets and valid inequalities are presented.     

Analytical chemistry and the cone penetrometer: In situ chemical characterization of the subsurface

The development of novel microanalytical techniques forin situ chemical characterization of the terrestrial subsurface environment has grown significantly over the last decade, particularly those instruments that are interfaced to the cone penetrometer. Cone penetrometer testing (CPT) has emerged as an effective means to introduce samplers and probes forin situ analysis of contaminants in soil and groundwater matrices. A variety ofin situ chemical samplers for CPT have been developed that can be driven into the subsurface to collect soil gas, groundwater, or soil samples at depth, thus providing a means of determining the vertical and horizontal extent of contamination. Cone penetrometer testing is also being explored as a means to deliverin situ subsurface sensor probes, including probes based on laser-induced fluorescence, Raman, and infrared spectroscopies for organics; on laser-induced breakdown and X-ray fluorescence spectroscopies for heavy metals; and on passive gamma-ray spectroscopy for radionuclides. The range of analytical technologies used in CPT for the determination of organic and inorganic species in the subsurface is described.     

一类非线性方程的迭代解及应用

利用锥理论和单调迭代方法研究了一类非线性方程解的存在唯一性及其迭代过程，对所述的映射没有作连续性、紧性或具有上、下解的假定．作为应用，把所获得的结果用到Banach空间一阶微分方程．     

非线性算子方程的迭代求解方法

在较弱的条件下,利用锥理论和单调迭代方法,建立了Banach空间中一类非线性算子方程的最大最小藕合解的存在性定理和不动点定理,并给出了相应的迭代逼近式及误差估计式,改进了一些相应结果.     

电纺丝制备高聚物纳米纤维

通过自制的电纺丝装置获得高聚物纳米纤维，发现不同高聚物纳米纤维具有不同的直径范围。对影响所得纳米纤维直径的静电压、高聚物溶液浓度等过程参数作分析，认为静电压与高聚物溶液浓度是影响试验进行的关键因素，并制约着其他工艺参数的调整。同时，结合静电喷雾及高速纺丝的理论对纺丝电子流体动力学过程作了一定探讨。     

集值映射序列的极限映射的锥弱次微分的若干性质

在文的基础上，给出了集值映射序列的极限映射的锥弱次微分的闭凸性和连通性。     

一类非单调二元算子方程的迭代解法

利用锥和半序理论，研究Banach空间一类不具有单调性的算子方程A（x,x）=x，其中A可表示A=A1＋A2,A1是混合单调的，A2是反向混合单调的，并得到了可解性定理．     

相交柱锥表面展开图的计算机绘制

根据曲面到平面的等距变换原理，运用可展曲面及其曲面上的截交线或相贯线变换到平面上的方法，使曲面展开变得更为简捷、精确，且更有利于计算机辅助几何设计中建立曲面展开的数学模型和合理的算法，尤其对开展精度要求高的曲面展开更为有利。通过对轴线相交的圆柱体和圆锥体数学模型的研究，建立了展开曲线方程，用VBA语言结合Atutomation技术编制了通用的计算机程序，将展开图在AutoCAD2000上加以绘制，实现了任意大小的圆柱与圆锥展开图的参数化CAD，从而在理论上开发了面向对象的参数化设计系统，并介绍了具体实现的方法、过程。在实际工程中，对计算机在相贯件下料中的应用，具有快速、准确、修改方便的特点。