膜结构填料的物化特性对精馏分离异丙醇/水体系的影响

选用了三种不同材料的中空纤维膜(PP,PS和PES)构建新型膜接触器结构填料,并对异丙醇/水体系进行了精馏分离过程研究.在新型膜接触器中,液相和气相分别在管程和壳程进行逆向流动.实验结果表明:三种结构填料对异丙醇/水体系的分离效果依序为PES>PP>PS.不同材料的中空纤维膜作为结构填料对异丙醇/水溶液体系的分离效率均...     

基于有效交叉点搜索的PS边界补偿重建算法

研究了快速成形数据处理中封闭PS边界曲线补偿重建算法，分析了快速成形数据处理过程中截面多边形补偿的特点及有效交叉点形成规律。提出了基于有效交叉点搜索的补偿边界重建的新算法。该算法在已开发的RPM数据处理软件中得到成功应用，可提高已有数据处理软件的稳定性，实现了RPM的OFFSET加工轨迹的生成。     

中文PDF文档数字水印算法

针对文本文档的真实性、完整性和版权保护问题,通过分析PDF文档和PostScript页面描述文件工作机制原理,提出一种专门针对中文PDF文档的数字水印算法.将根据原始文档字符特征码而生成的水印信息嵌入到文档字符间距中,从而实现了对文档内容的保护.实验结果表明,利用该算法使得中文PDF文档具有了良好的防篡改性.     

EPDM/PS交替多层复合材料的力学性能分析

用自行设计的微纳多层共挤出体系制备了三元乙丙橡胶/聚苯乙烯(EPDM/PS)交替多层复合材料。偏光显微镜和扫描电镜分析表明, 所制备的复合材料具有规则层状交替结构。与同组分的一般共混样品相比, 64层EPDM/PS交替复合材料表现出不同的拉伸断裂行为: 初期的PS断裂行为和后期的EPDM拉伸行为。EPDM和PS层保持了较好的连续性, 且EPDM层阻止了PS层裂纹向相邻PS层的发展, 使64层样品与同组分的一般共混样品相比具有较高的拉伸强度和杨氏模量。讨论了在PS相中加入相容剂苯乙烯-乙烯-丁烯-苯乙烯嵌段共聚物(SEBS)对64层EPDM/PS交替复合材料力学性能的影响, 发现SEBS的加入提高了PS相的韧性, 并且改善了EPDM层与PS层界面的相互作用。      

微量元素对1050铝基PS版电蚀性能的影响

研究了Mg、Mn含量对PS版电蚀性能的影响。利用电化学测试仪、扫描电镜及能谱仪检测分析了不同Mg、Mn含量的PS版电解腐蚀速率和腐蚀均匀性的差异。分析表明,Mg含量从0.001%提高到0.10%时,Mg更多地富集于铝板表面,形成微小的易腐蚀的含Mg复合氧化物颗粒,促进腐蚀,进而提高板基的腐蚀速率;Mn含量的增加能提高Mg元素在板基表面的分布均匀性,减少Fe元素在铝板表面的富集,降低Fe对腐蚀均匀性的危害。     

Effect of organoclay on the mechanical / thermal properties of microcellular injection molded polystyrene–clay nanocomposites

An organically modified montmorillonite was compounded with polystyrene (PS) in a twin-screw extruder. The organoclay polystyrene nanocomposites were then injection molded by conventional and microcellular methods. Nitrogen was used as the blowing agent. The effect of organoclay content on the mechanical and thermal properties was investigated. The results showed that when the MMT content was 1 wt.%, the nanocomposites have maximum tensile strength, wear resistance, and cell density. Moreover, the addition of organoclay increases the glass transition and decomposition temperature of the nanocomposites. The XRD results showed that the layer spacing of the nanocomposites decreases by comparison with the organoclay. TEM pictures showed that MMT is well dispersed within the PS matrix.     

Interpolymer radical coupling: A toolbox complementary to controlled radical polymerization

The current review focuses on the relevance and practical benefit of interpolymer radical coupling methods. The latter are developing rapidly and constitute a perfectly complementary macromolecular engineering toolbox to the controlled radical polymerization techniques (CRP). Indeed, all structures formed by CRP are likely to be prone to radical coupling reactions, which multiply the available synthetic possibilities. Basically, the coupling systems can be divided in two main categories. The first one, including the atom transfer radical coupling (ATRC), silane radical atom abstraction (SRAA) and cobalt-mediated radical coupling (CMRC), relies on the recombination of macroradicals produced from a dormant species. The second one, including atom transfer nitroxide radical coupling (ATNRC), single electron transfer nitroxide radical coupling (SETNRC), enhanced spin capturing polymerization (ESCP) and nitrone/nitroso mediated radical coupling (NMRC), makes use of a radical scavenger in order to promote the conjugation of the polymer chains. More than a compilation of macromolecular engineering achievements, the present review additionally aims to emphasize the particularities, synthetic potential and present limitations of each system.     

Microstructure and sliding wear behavior of pseudo-alloy PS45/CuA18 composite coating sprayed by HVAA technique

A pseudo-alloy PS45/CuAl8 composite coating was sprayed on steel substrate by high-velocity activated arc spraying (HVAA) process. Its sliding wear behavior at room temperature was evaluated by M-2000 wear tester. For comparison, a single CuAl8 coating was also prepared and tested under the same conditions. It is found that the pseudo-alloy composite coating consists of α-Cu and γ-Ni metallic matrix phases together with homogenously distributed minor A12O3, Cr2O3 oxide phases. Moreover, pseudo-alloy coating possesses much better sliding wear resistance than CuA18 coating due to the enhanced hardness and microstructural homogenization. Fatigue wear and abrasive wear are responsible for the wear-down mechanism of the pseudo-alloy coating.     

包装生产线用工控机PS/2接口的网络化实现

为了可靠地远程操作食品包装生产线上的工控机,设计了一种网络化PS/2接口终端,把键盘鼠标和工控主机分离,把外设和主机间的PS/2双向传输数据网络化,使得键盘和鼠标可以远程操控主机,并且在不同操作系统的主机间快速切换。此设计方便用户对工控主机的操控,增强了使用的灵活性。