以木聚糖为抗菌剂的木质地板抗菌性能

随着生活水平的提高,人们越来越重视室内家居环境的健康、环保问题.因此,研究、开发抗菌实木地板具有现实意义.采用贴膜法检测抗菌地板的抗菌性能:以木聚糖为抗菌剂,用8%浓度溶液浸泡杨木单板,接种一定数量的大肠杆菌和金色葡萄球菌.经过一段时间培养后,检测地板细菌数量.结果表明:经过木聚糖溶液处理的地板对大肠杆菌和金色葡萄球菌的抗菌率为73.58%和90.09%,抗菌等级达到Ⅱ级.     

基于滑移/非滑移异质界面的动压润滑性能优化

合理布置的滑移/非滑移异质界面可以提高流体动压润滑性能,但目前滑移区和非滑移区的组合方式大多采用单一的直线拼接法,没有针对流体润滑摩擦副的各类工况设计出相应的优化方案,为此本文建立了一组离散式二次方程来描述滑移区和非滑移区拼接轨迹,并引入计算域单元的宽长比作为优化变量,分别以液膜刚度和摩擦因数作为优化目标,通过MATLAB数值仿真求解不同宽长比条件下滑移区和非滑移区的最优拼接轨迹。结果表明,与直线拼接法相比,选取二次方程所描述的抛物线作为滑移区和非滑移区拼接轨迹的方法使流体润滑摩擦副在摩擦因数和液膜刚度等性能指标上都有所改善,而且根据不同的优化目标参数可以方便地绘制出最优拼接方案,验证了本文方法在改善动压润滑性能上的可行性和普适性。     

On implementing the symbolic preprocessing function over Boolean polynomial rings in Gröbner basis algorithms using linear algebra

Some techniques using linear algebra was introduced by Faugère in F4 to speed up the reduction process during Gr?bner basis computations.These techniques can also be used in fast implementations of F5 and some other signature-based Gr?bner basis algorithms.When these techniques are applied,a very important step is constructing matrices from critical pairs and existing polynomials by the Symbolic Preprocessing function(given in F4).Since multiplications of monomials and polynomials are involved in the Symbolic Preprocessing function,this step can be very costly when the number of involved polynomials/monomials is huge.In this paper,multiplications of monomials and polynomials for a Boolean polynomial ring are investigated and a specific method of implementing the Symbolic Preprocessing function over Boolean polynomial rings is reported.Many examples have been tested by using this method,and the experimental data shows that the new method is very efficient.     

基于MATLAB矩阵运算的大整数乘法设计与实现

大整数运算在信息安全、数学验证、基因工程等领域有着广泛的应用,设计有效的方案提高运算效率成为学者关注的热点。大整数乘法是大整数运算中的核心运算,对如何提高大整数乘法运算效率进行了分析总结,并利用MATLAB矩阵运算结合格子乘法等算法进行了设计与实现。实验表明通过MATLAB矩阵运算进行大整数乘法运算能有效的提高运算效率。     

Advance selling in the presence of product diffusion effect

Product diffusion refers to the phenomenon that the later demand is dependent on the early sales. To investigate how a firm’s advance selling strategy is affected by the effect of product diffusion, we consider a monopolist seller who sells a fashionable product in a market that comprises of myopic and strategic consumers over two periods (i.e., the advance selling season and the regular selling season). For a linear product diffusion effect we find that, when the effect of product diffusion is positive, the seller may set an extremely high advance selling price to induce the strategic consumers to purchase in the regular selling season, which is counter-intuitive. Moreover, the optimal procurement quantity for the seller may increase in the negative effect of product diffusion and decrease in the amount of strategic consumers. When we extend our model to consider a concave quadratic product diffusion effect, however, the optimal procurement quantity is concave in the amount of strategic consumers. Numerical studies are further presented to discuss the managerial insights.     

Isogeometric Analysis-Based Topological Optimization for Heterogeneous Parametric Porous Structures

Porous structures widely exist in nature and artifacts, which can be exploited to reduce structural weight and material usage or improve damage tolerance and energy absorption. In this study,the authors develop an approach to design optimized porous structures with Triply Periodic Minimal Surfaces(TPMSs) in the framework of isogeometric analysis(IGA)-based topological optimization.In the developed method, by controlling the density distribution, the designed porous structures can achieve the opt...