Studies of the Rheological Behavior of Polypropylene/Polyamide-6 Blend by Capillary Rheometer

The theological behavior of blend, e. g. polypropylene, PP, with polyamide - 6, PA6, has been investigated. Results show that this blend is a pseudo plastic fluid and the amount of PA6 seems to be a dominator to influence all theological properties. In addition to the expected influence by temperature generally for polymer, it has been found the amount of PA6 is valid in a range, e. g. 0 - 20% corresponding to the PP amount, i. e. in this range, the larger the PA6 added, the larger is the non-Newtonian index, n, and this is obviously especially for PP/PA6 blend with the high shear stress.     

Development and Performance Study of CaCO3 Modified PP Spun-Bonded Nonwovens

The manufacturing process of CaCO3 modified Polypropylene (PP) spun-bonded nonwovens was studied.Then the effect of the additive amount of CaCO3 on mechanical properties of the product was analyzed,and a compatible mechanism between CaCO3 partides and the main component of PP was established.In the end,the mechanical performance of the products was studied when the natural light degradation was changed.The experiment results show that after adding CaCO3 to the PP spun-bonded nonwovens and through the application of complex coupling agent and organic modification,hardcore of rigid particles and polymer composite elastomers can be combined together tightly and disperse rapidly and evenly in the main part of PP.In addition,CaCO3 can catalyze the light degradation of PP spun-bonded nonwovens.The larger the content of CaCO3 is,the faster the light degradation will be.     

PROJECTION-PURSUIT BASED PRINCIPAL COMPONENT ANALYSIS： A LARGE SAMPLE THEORY

The principal component analysis （PCA） is one of the most celebrated methods in analysing multivariate data. An effort of extending PCA is projection pursuit （PP）, a more general class of dimension-reduction techniques. However, the application of this extended procedure is often hampered by its complexity in computation and by lack of some appropriate theory. In this paper, by use of the empirical processes we established a large sample theory for the robust PP estimators of the principal components and dispersion matrix.     

PP333对荸荠试管苗增殖调控的研究

在增殖培养基中添加0.25 mg.L-1~1.0 mg.L-1PP333能有效调控荸荠试管苗的形态发生能力,提高增殖系数,减少繁殖代数。培养壮苗后,一次性供试生根苗多,缩小了试管苗生长差异,提高了试管苗炼苗的成活率。     

PP－g－GMA反应增容剂对PP／PA6共混物的形态及力学性能的影响

研究了ＰＰ－ｇ－ＧＭＡ对ＰＰ／ＰＡ６（羧端基尼龙）共混物的反应增容作用及其对共混物力学性能的影响，考察了反应增容与非反应增容的优劣．研究结果表明，ＰＰ－ｇ－ＧＭＡ对ＰＰ／ＰＡ６共混物具有显著的反应增容作用，并且增容效果优于ＰＰ－ｇ－ＭＡＨ的非反应增容效果；ＰＰ－ｇ－ＧＭＡ的反应增容对共混物力学性能的影响远大于ＰＰ－ｇ－ＭＡＨ的非反应增容对共混物力学性能的影响．     

Present random computations in a uniform way

Some equivalent definitions for PP are introduced, which allows us to present the randomized complexity classses RP, NP, PP, BPP in a uniform format.     

Effects of Porosity on Structure and Performance of PP Meshes for Reparing Pelvic Floor Defects

Currently, polypropylene （PP） synthetic mesh is a kind of common material used for pelvic floor＇s repairing and reconstruction. The repairing mesh is generally made with different hole shape and size. Porosity is one of the most important indicators of PP mesh. Two different-structure PP meshes are selected through adopting corresponding target density in the heat setting process for meshes owning different porosity. Then performance and structure of two kinds meshes with different porosity are tested. The results showed that： the increase of porosity leaded to the decreases of meshes＇ thickness, tensile strength and bursting strength. Meshes＇ bending stiffness was reduced and they became softer, but there was no significant change in suture pulling-out force, which maybe associated with the large aperture of PP meshes.     

基于JPEG硬编码的嵌入式无线图像传输处理终端

针对多媒体教学中, 图像信息因距离等因素而不能清晰地获取数据且不能对教师的授课内容进行自动接收存储问题, 将嵌入式处理器与图像采集模块及WiFi(Wireless Fidelity)相结合, 并引入了JPEG(Joint Photographic ExpertsGroup)硬件编解码及PP(Post Processor)支持图像缩放及格式转换技术, 设计了基于JPEG硬编码的嵌入式无线图像传输处理终端。给出了整体方案, 并进行了编程调试, 验证了系统的整体架构、 通信协议及核心算法的可行性与完备性。通过实验证明, 学生端能自动接收显示并存储教师端广播的图像数据, 提高了学习效率, 实现了终端之间图像信息的交互。终端之间连接实时高效、 图像数据的采集压缩显示速度及无线模块的传输速度达到了预期效果。     

纳米SiO2修饰玻纤表面对玻纤/聚丙烯复合材料界面性能的影响

借助纳米颗粒的高比表面积特性,将纳米二氧化硅通过化学接枝方法修饰玻璃纤维表面,制备玻璃纤维/聚丙烯（PP）热塑复合材料。通过SEM表征纳米二氧化硅在玻璃纤维表面的分布形态,结果表明纳米颗粒在纤维表面分散良好;通过界面剪切强度测试（IFSS）和界面断裂韧性测试（G_ⅡC）表征复合材料界面的静态力学性能,结果显示材料的界面剪切强度与界面断裂韧性同时获得了较大的提升;动态热机械分析测试（DMA）的结果表明复合材料在动态测试下的综合界面结合性能均得到较大的提升。     

水稻磷酸酯酶2A基因蛋白的原核表达载体构建、表达和纯化

利用PCR技术,从水稻品种日本晴幼穗cDNA中扩增磷酸酯酶2A的基因ORF片段,并将其克隆入原核表达载体pGEX-6p-1中构建重组质粒pGEX-6p-1-PP-2A,经限制性内切酶酶切鉴定以及测序结果表明成功构建了原核表达载体pGEX-6p-1-PP2A。转化E.coli JM109并通过终浓度为0．4mmol／L的IPTG诱导,表达出39kD的CST-PP2A融合蛋白,并用蛋白亲和层析柱GSTrap FF对表达产物进行纯化,为下一步的研究打下了实验基础。