改性EPS功能胶粘剂的研制

本文介绍了采用混合溶剂溶解法，将废聚苯乙烯泡沫塑料（ＥＰＳ）中引入活性基因，研制出一种性能优良、用途广泛、价格低廉的功能胶粘剂的方法．通过筛选，确定了混合溶剂的配方及各种添加剂的比例．并对胶粘剂的性能和主要技术指标进行了测试．同时，对其用做涂料的防水性能进行了一定的研究．初步探索出一种新的综合利用废聚苯乙烯泡沫塑料的方法．     

多元醇还原法制备Co-Ni和Fe-Co-Ni磁粉

通过多元醇还原法可以制得尺寸范围从几微米到几十纳米的球形、单分散和Co-Ni系和Fe-Co-Ni系磁粉,并在2～18GHz频率范围内研究其微波磁特性。实验表明,此法制得的Co-Ni系和Fe-Co-Ni系磁粉的物理化学特性随着Co含量的不同而呈现出一定规律性变化。     

A rapid forecasting method for mountain flood disaster based on machine learning algorithmsEI北大核心CSCD

基于高精度水动力模型与机器学习技术,运用极限随机树(ERT)及KNN算法,构建了高分辨率山洪灾害快速预报模型。利用确定系数、平均绝对误差和均方根误差3种指标评估模型的整体可靠性,同时,截取流域出口断面流量验证模型的预报性能。结果表明:所建模型预报结果与水动力模型模拟结果淹没范围基本一致,流域淹没范围平均相对误差低于5%,模型整体稳定可靠;流域出口断面流量平均相对误差低于10%,断面平均水深、流速平均相对误差低于5%,模型预报性能良好;模型可在10s内完成最大淹没情况计算并输出淹没范围图,能为紧急决策提供足够的前置时间,协助决策者更好地采取应对措施。     

Preparation and characterization of polyacrylonitrile-based membranes: Effects of internal coagulant on poly(acrylonitrileco-malefic acid) ultrafiltration hollow fiber membranes

Ultrafiltration hollow-fiber membranes (UHFMs) ofpoly(acrylonitrile-co-malefic acid) (PANCMA) were prepared by a dry-wet phase inversion process. The morphologies of inner surface and cross section for these hollow fibers were inspected with scanning electron microscopy. It was found that, by increasing the amount of solvent DMSO in internal coagulant, the number and size of macrovoid underneath the inner surface decreased. The water flux of the UHFMs also decreased while the bovine serum albumin rejection increased minutely. These results were interpreted based on the ternary phase diagrams for the PANCMA/DMSO/(H₂O+DMSO) system, which was obtained from the experimental cloud point measurements and empirical linearized cloud point relation. It was envisaged that the membrane surface could be further modified by the reaction of acid groups with poly(ethylene glycol).     

Polyaniline/FE3O4 magnetic nanocomposite prepared by ultrasonic irradiation

Ultrasonic irradiation is employed to assist the chemical oxidative polymerization of aniline in the presence of Fe₃O₄ nanoparticles in order to prepare a polyaniline (PANI)/Fe₃O₄ magnetic nanocomposite. In the chemical oxidative polymerization of aniline in the initially neutral medium, the optimum molar ratio of the oxidant ammonium persulfate to the monomer aniline is 2 : 1. The prepared PANI is in the emeraldine form and is doped by sulfate anions. Fe₃O₄ particles are encapsulated by PANI and dispersed well in PANI. Fe₃O₄ increases the doping level and decreases the crystallinity of PANI. The PANI/Fe₃O₄ nanocomposite possesses conductivity and magnetic properties. Increasing the Fe₃O₄ content increases the magnetization of the PANI/Fe₃O₄ composite but decreases its conductivity. © 2006 Wiley Periodicals Inc. J Appl Polym Sci 102: 2107–2111, 2006     

超细氧化铁的制备进展

超细氧化铁制备工艺和进程的研究与控制,对其微观结构和宏观性能具有重要影响。综述了新型超细材料—氧化铁的主要类别、现有的制备方法以及研究现状,并分析了不同方法制备超细氧化铁的优缺点。同时,针对目前制备超细氧化铁存在的一些问题,也提出了今后进一步的研究方向。     

炭毡/炭复合材料的氧化防护

以磷酸和氢氧化铝为原料，配制了不同P／Al摩尔比的酸式磷酸盐溶液，通过浸溃法，对炭毡／炭复合材料的氧化防护进行了研究。结果表明，提高P／Al摩尔比可以增加材料抗氧化性。经P／A1摩尔比23：1的溶液浸溃，800□热处理后的炭毡／炭复合材料在600□下氧化几乎没有失重。     

Controlled grafting from poly(vinylidene fluoride) microfiltration membranes via reverse atom transfer radical polymerization and antifouling properties

A reverse atom transfer radical polymerization (RATRP) with benzoyl peroxide (BPO)/CuCl/2,2-bipyridine (Bpy) was applied onto grafting of poly(methyl methacrylate) (PMMA) and poly(poly(ethylene glycol) methyl ether methacrylate) (PPEGMA) from poly(vinylidene fluoride) (PVDF) microfiltration (MF) membrane surfaces, including the pore surfaces. The introduction of peroxide and hydroperoxide groups onto the PVDF membranes was achieved by ultraviolet (UV) irradiation in nitrogen, followed by air exposure. RATRP from UV pretreated hydrophobic PVDF membranes was then performed for attaching well-defined homopolymer. The chemical composition of the modified PVDF membrane surfaces was characterized by attenuated total reflectance (ATR) FT-IR spectroscopy and X-ray photoelectron spectroscopy (XPS). The surface and cross-section morphology of membranes were studied by scanning electron microscopy (SEM). The pore sizes of the pristine PVDF and the PMMA grafted PVDF membranes were measured using micro-image analysis and process software. With increase of graft concentration, the pore size of the modified membranes decreased and became uniform. Kinetic studies of homogeneous (in toluene solution) system revealed a linear increase in molecular weight with the reaction time and narrow molecular weight distribution, indicating that the chain growth from the membrane surface was a “controlled” or “living” grafting process. The introduction of the well-defined PMMA on the PVDF membrane gave rise to hydrophilicity. Protein adsorption and protein solution permeation experiments revealed that the UV pretreated hydrophobic PVDF membrane subjected to surface-initiated RATRP of methyl methacrylate (MMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) exhibited good antifouling property.     

Tailor‐made controlled rheology polypropylenes from metallocene and Ziegler–Natta resins

Production of controlled rheology polypropylenes (CRPPs) is practiced industrially by modifying existing commodity Ziegler–Natta resins through peroxide‐induced β‐scission reactions, resulting in materials with controlled rheological properties and accompanying narrower molecular weight distributions (MWDs). In this work, this methodology was studied using both metallocene‐based polypropylenes (mPPs) and Ziegler–Natta‐based polypropylenes (ZN‐PPs). Numerical simulations based on a previously proposed kinetic model indicated that the nature of the starting resin has a significant effect on the control of MWD polydispersity index (PDI) and weight‐average molecular weight ( ${\overline{M}}_W$) of the resulting CRPP. Based on these observations, experiments were carried out to demonstrate the feasibility of producing CRPP with targeted molecular and rheological characteristics. Commercial mPP and ZN‐PP resins were selected to produce CRPP with similar ${\overline{M}}_W$ or melt flow rates (MFRs) but varying PDIs. The rheological properties and MWDs of these materials were evaluated through oscillatory shear and gel permeation chromatography (GPC) measurements and their extrusion behavior was briefly studied and assessed with respect to these properties. POLYM. ENG. SCI., 59:1114–1121 2019. © 2019 Society of Plastics Engineers     

区域逻辑运算实现复杂形状目标区域孔径填充

本文研究了图像的区域编码和区域逻辑运算，并利用此运算在保持目标轮廓不变的情况下实现了目标区域孔径的填充。研究结果表明，该算法可以广泛应用于复杂轮廓目标区域的填充和图像检测。