氧化微晶纤维素增强淀粉基塑料的制备和性能

将微晶纤维素(MCC)经NaIO4氧化制备出双醛纤维素(DAC),并以此对热塑性淀粉(TPS)进行增强,再以马来酸酐接枝聚乙烯(MA-g-PE)为增容剂,与低密度聚乙烯(LDPE)共混,制备出DAC/TPS/LDPE复合淀粉基塑料。通过电子拉力机、吸水率测试、热重法和转矩流变仪,研究MA-g-PE用量对DAC/TPS/LDPE性能的影响。结果表明:添加MA-g-PE可有效提高复合材料的力学性能、耐水性能和加工性能,且当添加量为4%时,淀粉基塑料的综合性能最佳。     

Influence of ultrasonic treatment on the structure and emulsifying properties of peanut protein isolate

Effects of ultrasonic treatment on emulsifying properties and structure of peanut protein isolate (PPI) were evaluated by analysis of particle size distribution, protein surface hydrophobicity, SDS-PAGE, circular dichroism spectra and environmental scanning electron microscopy. The emulsifying properties of the PPI were found to be improved by ultrasonic treatment. The mean particle size decreased from 474.7 nm to 255.8 nm while the molecular weight remained unaffected. The results of intrinsic fluorescence spectroscopy and surface hydrophobicity indicated that ultrasonic treatment induced tertiary structural changes of the proteins in PPI. Emulsifying activity index and emulsion stability index were found to be correlated fairly well with surface hydrophobicity (H₀) (r = 0.712 and r = 0.668, respectively).     

硼酸三甲酯流化催化精馏工艺的研究

以负载氯化锂强酸性离子交换树脂为催化剂,对硼酸三甲酯流化催化精馏工艺进行了研究。结果表明:催化精馏塔1适宜的操作条件为:回流比为4、进料高度为0.6 m、进料速率为4.48 m L/min、全塔压降为200 mm水柱、塔釜1的反应体积为200 m L;催化精馏塔2适宜的回流比为10。催化精馏塔1中硼酸三甲酯的收率为82.4%,精馏塔2中硼酸三甲酯的收率为97.8%。     

杨木无催化甘油法制浆工艺及其性能的研究

研究了杨木无催化甘油法制浆的主要因素对成浆状况的影响规律,同时对无催化甘油法制浆的打浆性能和成纸性能进行了初步评价,比较了无催化甘油法制浆和盘磨机械浆（RMP）性能的主要差异。结果表明：杨木无催化甘油法制浆的最佳工艺条件为反应温度210℃、反应时间60min和反应液比1：8,在此条件下浆料的粗浆得率为75．9％,细浆得率为71．4％：该方法制得浆料初始打浆度为11°SR,对应的纸张裂断长1．34km,抗张指数13．10N·m／g,耐破指数1．28kpa·m2／g,松厚度2．15cm3／g以及白度12．46％ISO;杨木无催化甘油法制得浆料比杨木RMP更易打浆,成纸的裂断长和抗张强度远高于杨木RMP,但其松厚度略低于杨木RMP。通过实验得出杨木无催化甘油法制浆具有工艺简单、得率高、易打浆及强度高等优点。     

对甲基苯磺酸催化合成三乙酰没食子酸

以没食子酸与乙酸酐为原料,对甲基苯磺酸作催化剂,合成三乙酰没食子酸,考察了原料配比、催化剂用量、反应时间、反应温度对产品的影响。结果表明,酰化反应较佳的工艺条件是：n（没食子酸）∶n（乙酸酐）∶n（对甲基苯磺酸）=1∶2∶0.5,反应时间为1.5 h,反应温度为60℃,此时三乙酰没食子酸的收率为77.58%。     

[Poly(styryl)phenanthroline]palladium as heterogeneous catalyst for heck arylation using iodobenzene

The effects of different bases on Heck arylation catalyzed by the polymeric catalyst

have been studied. The yield of product and the lifetime of the catalyst are influenced by the nature of the base used. The leaching of palladium from the polymeric catalyst is caused mainly by the competitive complexation of the ligands existing in the reaction media towards the metal. When tributylamine is replaced by DMF-H₂O-NaOAc, the catalyst can be easily recovered and reused, the yields are higher and the products are found to be more pure. For the reaction of acrylamide with iodobenzene, even after ten consecutive runs the recovered catalyst still has high catalytic activity. In the DMF-H₂O-NaOAc system, the catalyst can also tolerate the presence of a variety of functional groups; acrylamide could be introduced to react with substituted iodobenzenes in good yields.     

Plasma-polymerized metal phthalocyanine films: Preparation,properties and morphology

Thin polymeric nickel phthalocyanine (NiPc) and lead phthalocyanine (PbPc) films were prepared by the plasma-polymerization method. The phthalocyanine ring structure was largely undisturbed by this process. Lead phthalocyanine deposited in the high RF flux density regime produced some lead particles incorporated in the film, which were confirmed by electron diffraction patterns. In general the crystallite size of plasma-polymerized phthalocyanine films was much smaller than that for the chemical vapor deposited (CVD) phthalocyanine films. Plasma-polymerized phthalocyanine films deposited on interdigitated electrodes were evaluated as sensors for oxidizing and reducing gases. They showed fast response and excellent sensitivity to ppm level concentrations of NO₂ in air.     

纹理图像的局部区域提取方法

纹理分析是图像处理与识别的重点和难点之一。综合运用数字图像处理和计算机视觉技术,应用VC++开发环境,以竹材横截面细胞壁晶区为具体研究对象,通过应用各种结构微型窗口,比较近距离点之间像素值的方法将图像进行分割,再运用数学形态学的方法对图像进行增强处理,将人们感兴趣的区域孤立出来,以方便对所需区域进行形状描述、收集信息和求取图像特征参数。所开发的程序可以取得较好的纹理分析效果,其界面友好、使用方便。     

Stability and growth of silicalite seeds: an observation of initial breeding

The stability of silicalite seeds in solution is shown to depend on the cations in the liquid solution and the way in which seeds have been treated. Calcined seeds dissolve in caustic solutions, whereas uncalcined seeds are stable in some solutions. Na⁺ solutions appear to have greater solvating properties for silicalite than do NH₄⁺ solutions. Fresh seeds are shown to grow in a silicalite synthesis mixture. Dried or calcined seeds grow, but also produce a new population of nuclei that results from an initial breeding mechanism.