高职计算机实践课与“任务驱动”教学

高职计算机实践课程具有较强的实践性、应用性。基于这一特点,"问题(任务)驱动"是一种将传统教学方式转变为以解决问题、完成任务为主的多维互动式的教学理念;采用实际生活中的典型案例开头(提出问题、明确目标),逐渐展开(分析解决问题),将知识点融入任务之中,完成任务的同时又掌握相应的基本知识。是将再现式教学转变为探究式学习的一种方式。     

乳胶涂料中填料粒径测定与分散剂的选择

介绍了重力沉降法和容量沉降法两种测定乳胶涂料中填料粒径的方法。通过比较粉体粒径结果显示：沉降法比激光法更形象直观，更能代表体系粒径真实情况。以滑石粉、重钙、轻钙粉体为基准，采用不同用量、不同类型的分散剂的容量沉降法进行比较得出：用容量沉降法能定量地对分散剂性能做出评价。     

Fractional partial differential equation denoising models for texture image

In this paper,a set of fractional partial differential equations based on fractional total variation and fractional steepest descent approach are proposed to address the problem of traditional drawbacks of PM and ROF multi-scale denoising for texture image.By extending Green,Gauss,Stokes and Euler-Lagrange formulas to fractional field,we can find that the integer formulas are just their special case of fractional ones.In order to improve the denoising capability,we proposed 4 fractional partial differential equation based multiscale denoising models,and then discussed their stabilities and convergence rate.Theoretic deduction and experimental evaluation demonstrate the stability and astringency of fractional steepest descent approach,and fractional nonlinearly multi-scale denoising capability and best value of parameters are discussed also.The experiments results prove that the ability for preserving high-frequency edge and complex texture information of the proposed denoising models are obviously superior to traditional integral based algorithms,especially for texture detail rich images.     

Theoretical assessment of the catalytic (Pt/TiO2) oxidation of formaldehyde at ambient temperature

A recent article [C. Zhang, H. He, K. Tanaka, Catal. Commun. 6 (2005) 211] investigates the use of a Pt/TiO₂ catalyst for the oxidation of formaldehyde. The findings demonstrate nearly complete oxidation at ambient temperature (25 °C) for values of the surface velocity in the range 5–10 × 10⁴ h⁻¹ and a 45% destruction when using a surface velocity of 20 × 10⁴ h⁻¹.In the present communication, this oxidation was assessed by theoretical considerations of the reaction kinetics. The destruction efficiency was predicted using a first-order reaction rate expression, combined with different theoretical or semi-empirical equations for the intrinsic reaction rate constant. Predicted and experimental data are in fair agreement, thus validating the theoretical approach and confirming the experimental results.     

NETEM阅读部分的真实性分析

从真实性的角度出发,利用Bachman的任务特征框架分析了NETEM阅读理解部分对考生交际语言能力的测试.分析表明,NETEM在输入材料方面有较高的真实性,任务涉及的语言能力的真实性也有很大的提高.但从输入与回答之间的关系看,个别题目未能体现交际语言能力的特点,仍有待改进.     

基于均衡接近度灰关联的Slope One算法

作为一种基于项目的协同过滤推荐算法,Slope One算法易于实现且高效。但由于Slope One算法未考虑用户相似性,导致其在处理涉及用户关系的个性化推荐任务时性能不高。针对以上问题,提出了改进的Slope One算法。提出一种均衡接近度灰关联分析方法计算用户之间的均衡接近度,利用均衡接近度度量用户间的相似程度,然后将均衡接近度值融入到Slope One算法中进行评分预测,在MovieLens和Epinions数据集下的对比实验表明,该算法具有更低的平均绝对误差（MAE）和均方根误差（RMSE）,提高了预测的准确度和推荐质量。     

波浪对圆柱外接圆弧型防波堤绕射的解析计算

在微幅波绕射理论的基础上,使用特征函数展开法,推导了圆柱外接圆弧型防波堤复合结构的水波绕射的解析解,并据此计算了该结构所受到的波浪载荷以及绕射波面分布。计算结果表明:与单一圆柱相比,外接圆弧型防波堤的存在可明显降低作用于圆柱的波浪载荷和圆柱表面的波浪爬高;采用外接堤表面密实或透空而内圆柱表面透空的结构形式可以取得圆柱防浪的较佳效果;结构透空系数、波浪入射角度、外接堤张角、外堤半径与水深比、水深与波长比等因素的变化对绕射波浪作用均存在一定影响。     

弧形短导航墙对船闸下游引航道内水流结构的影响

通过物理模型试验,结合理论分析,研究了在不同下游水深条件下,直导航墙长度L变化对船闸下游引航道保护长度的影响,并在此基础上研究了增设弧形短导航墙对水流结构的调整与影响。物理模型试验研究表明:直导航墙长度的增加有利于改善船闸引航道口门区的通航条件,但在达到一定长度之后,再增加直导航墙长度对引航道口门区水流结构的改善效果减弱;弧形短导航墙对改善下游引航道保护区域内水流结构有很好的效果,选用较小纵向参数a和较大横向参数b效果更好,但张角不宜过大。     

Numerical analysis of rainfall effects in external overburden dump

The effect of slope angle for external overburden dump in response to average and heavy rainfall has been analyzed using a two dimensional finite difference method of transient water flow through unsaturated–saturated soil. The external dump stability is evaluated for five geomaterial types on the basis of globally accepted safety factor analysis technique, based on shear strength reduction approach using finite difference method. The results obtained from the finite difference method of analysis indicate that the external dump with more than 30° slope angle is greatly influenced by the rainfall under the studied conditions for geomaterial 3, 4 and 5, whereas dumps with geomaterial 1 and 2 remain safe. The analysis shows that major slope failure is out of preview for the studied rainfall conditions.