C10芳烃的开发利用

Ｃ１０芳芳烃资源集中，用途广泛，蕴茂着巨大经济效益。Ｃ１０芳烃的开发已引起国内外的重视。本文重点概述了国内我生产技术和今后发展趋势，以及Ｃ１０芳烃综合利用的经济效益，为Ｃ１０芳烃的开发利用提供可参考的意见。     

T-ZnO晶须增强环氧树脂复合材料的抗静电性

研究了T—ZnO晶须增强环氧树脂复合材料的抗静电性。结果表明：具有半导体性的T—ZnO晶须在复合材料中，相互搭接形成导电通路，以价带传导方式传导电荷，而起抗静电作用，使环氧树脂材料的体积电阻率降低了8个数量级，用比表面因子修正了网络形成临界体积分数模型。T—ZnO晶须的网络形成临界体积分数(0．057)是球形粒子的网络形成临界体积分数(0．38)的1／10。     

乙醇-水体系渗透汽化分离过程的影响因素

为了考察乙醇-水体系渗透汽化实验中影响因素对亲水性PAA-Al2O3复合膜分离性能的影响,采用中心组合旋转设计方法设计实验,以渗透通量和选择性为实验响应,建立了以接枝丙烯酸单体浓度、操作温度和料液浓度为变量的回归模型方程.通过回归模型的分析,发现在乙醇-水渗透汽化脱水实验过程中,对渗透通量影响最明显的是操作温度,其次是料液浓度;对选择性影响最明显的则是操作温度与料液浓度间的交互作用,其次是接枝丙烯酸单体浓度.为了对乙醇-水体系的渗透通量和选择性进行优化,运用满意度函数方法分析了回归模型方程.结果表明,料液浓度为95％(wt)的乙醇-水共沸混合物的优化条件为接枝丙烯酸单体浓度为8％(wt)和操作温度为55.9℃,其总体满意度函数值为0.50,优化结果是令人满意的.     

Classic and local analysis of corrosion behaviour of graphite and stainless steels in polluted phosphoric acid

In phosphoric acid solution (40% H₃PO₄), the corrosion behaviour of graphite and stainless steels was studied by the use of different electrochemical methods, namely polarization curve analysis, electrochemical impedance spectroscopy (EIS) and scanning vibrating electrode technique (SVET). The combined effect of chemical impurities and the increase of medium temperature was studied to approach the real conditions in the process of phosphoric acid manufacturing. It was found that the current density measured by polarization curves increased with the presence of chloride and sulphate ions in the acid solution whatever the tested material. Compared to stainless steels, graphite had the best corrosion resistance in polluted phosphoric acid. However, for graphite the increase of temperature from 20 to 80 °C induced an increase of the corrosion rate and potential and a decrease of the resistance confirmed by EIS results. Subsequently, local currents were detected at the surface of the sample by using the scanning vibrating electrode technique. From the data obtained, graphite surface manifested a distinctive behaviour from that of stainless steels. A generalized corrosion was occurred on graphite whereas a localized corrosion was observed for stainless steels. These results show a clear interest of graphite as component material in some of the equipments of the phosphoric acid industry.     

Drag force on a circular cylinder midway between two parallel plates at very low Reynolds numbers—Part 1: Poiseuille flow (numerical)

At very low Reynolds numbers, we calculate the drag force exerted on a circular cylinder in cross flow fixed midway between two parallel plane walls which are fixed while the fluid experiences a Poiseuille profile at upstream and downstream. The drag wall correction factor is numerically investigated from a very weak interaction to the lubrication regime. The Navier-Stokes and continuity equations are expressed in the stream function and vorticity formulation and are rewritten in an orthogonal system of curvilinear co-ordinates. These equations are solved with using a finite differences method. The generation of the grid was carried out by the singularities method. We calculated the separate contributions of the pressure and viscous forces numerically. At very weak interactions, our numerical results are in good agreement with those obtained analytically by Harrison (Trans. Camb. Phil. Soc. 23 (1924) 71) and Faxèn (Proc. Roy. Swed. Acad. Eng. Sci. 187 (1946) 1). In the lubrication regime these numerical calculations are in very good agreement with those we carried out by asymptotic expansion. So that, the accuracy of the numerical code is tested. This analysis allowed us to show how that the pressure term prevails over the viscosity term in the lubrication regime. At very weak interaction, these forces have the same value.     

一种改进的快速图像修复算法

目前基于结构的图像修复算法中,基于快速行进的图像修复算法能够简单快速的修复数字图像中的破损区域,但是修复效果一般,特别是边缘区域的保持效果较差.在快速行进算法中引入了梯度权函数和距离权函数,通过对邻近点的加权计算进行排序,然后按权值大小对破损区域进行逐步修复,并利用梯度排序对边缘进行保持.实验结果表明该算法修复效果要优...     

Linear alkylbenzene

Linear alkylbenzene (LAB) was introduced in the mid-1960s as a raw material for cleaning products. Since then, continuing and explosive research on its biodegradation and on its environmental and human toxicity has been performed. The efficiency of linear alkylbenzene sulfonate as surfactant is clearly established, and it is one of the safest and most cost-effective products in widespread commercial use. The aim of the present paper is to survey the most important developments and understandings of the chemistry of LAB production and of its physical and environmental properties. The expected consequence of this analytical survey is to envisage the continuous challenges for the detergents industry in catalytic production of LAB, better control of selectivity, replacement of corrosive and mineral liquid acid catalyst by heterogeneous acid catalyst and the maintenance of competitiveness of LAB with respect to natural alcohols.     

高压微雾在蒸发冷却空调机组中的应用

为了得到填料-高压微雾对组合式空调机组的降温效果,测试1台55 000m3/h风量的填料-高压微雾组合式空调机组.采用对比方法,将5种不同的测试的降温效果进行对比.实验数据表明,高压微雾和填料上采用三维布水相结合对空调机组的降温最为显著.从研究结果上看,高压微雾不仅是人们传统认识上的加湿器,还是一台良好的冷却器,能够对空气进行降温,满足一些场所降温的需要,具有广泛的应用范围.     

IEEE 802.11的DCF机制媒介接入延时分析与仿真*

在改进的马尔可夫模型的基础上引入Z变换,分析了802.11的DCF机制 MAC延时性能,研究了从非饱和到饱和信道状态的延时性能。通过MATLAB数值分析和OPENT 10.0网络仿真,基于马尔可夫模型的MAC延时分析能够与网络仿真的MAC延时很好地吻合,验证了分析模型在预测媒介接入延时方面的有效性,为无线分布式系统的进一步设计提供理论依据和数据参考。     

高职教育转型期:思想流变和人才培养体系创新

实用主义教育思想与“实用教育”思想是2种对立的教育思想。近代中国职业教育受到2种思想的影响,当前高职教育是在社会效率主义范式下发展的“实用教育”。随着全球经济减缓,我国经济发展速度减慢,社会对应用性人才需求特点转变,高职教育“实用教育”范式正在向实用主义教育范式演化。浙江纺织服装职业技术学院作为纺织服装特色鲜明的高职院校,针对国内外经济环境变化,行业内人才需求的变化,对原“班-项-厂-团”式人才培养体系进行了重新的审视,认为应在原有体系中融入更多实用主义教育元素,而实施两创人才战略就是其中的方法之一。