不同形貌氢氧化镁的化学合成及影响因素

对不同形貌氢氧化镁的化学合成及外部生长环境进行了综述。尤其对影响氢氧化镁结晶性能和形貌起关键作用的因素，如碱性沉淀剂的选择、合成温度的确定、不同镁盐的影响、碱和镁盐的初始浓度及配比、水热处理、反应物的混合方式、晶形控制剂的加入等，进行了详细的阐述。     

Irganox(R) HP-136的抗氧化机理及对聚丙烯加工稳定性的影响

介绍了Irganox(R) HP-136在PP加工中的作用,表明它能有效地捕获烷基自由基,与传统的受阻酚类及亚磷酸酯类抗氧剂复配与传统的二元抗氧稳定体系相比,具有添加量少、抗氧性能优等优点.比较了Irganox(R) HP-136(3-芳基-苯并呋喃酮)与传统抗氧剂的抗氧机理,并分析了在聚合物稳定体系中的作用.     

HS－900有机硅密封抗渗防水剂性能的研究

ＨＳ－９００有机硅密封抗渗防水剂是一种新型的有机硅改性硅酸盐防水材料。具有良好的抗渗性能和耐酸碱腐蚀能力。将其涂于低标号混凝土材料上，效果尤其明显。     

焙烧硫酸铁铵催化合成季戊四醇双缩苯甲醛

以硫酸铁铵经600℃高温焙烧制得一类新型固体酸催化剂，该催化剂在合成季戊四醇双缩苯甲醛中具有较高的催化活性，其优化条件是：苯甲醛与季戊四醇物质的量比为2．0：1，催化剂用量为5％(以醇的质量为准)，回流温度83℃，反应时间2．5h，在此优化条件下，反应产率为87％。且催化剂容易制备，可连续使用。     

国外ABS生产技术进展

综述了世界ＡＢＳ树脂的生产及供求，介绍了各种生产工艺的进展，对其技术特点及产品性能进行了比较。     

Preparation of superparamagnetic immunomicrospheres and application for antibody purification

A novel and effective protocol for the preparation of superparamagnetic immunomicrospheres has been developed. First, micro‐size magnetic poly (methacrylate‐divinylbenzene) (PMA‐DVB) spheres were prepared by a modified suspension polymerization method. The oleic acid coated magnetite (Fe₃O₄) nanoparticles made by coprecipitation were mixed with monomers of MA, DVB, and initiator benzoyl peroxide (BPO) to form oil in water emulsion droplets with the presence of poly (vinyl alcohol) (PVA‐1788) as a stabilizer. The polymerization reaction was carried out in a 2‐L beaker equipped with four vertical stainless steel baffleplates by increasing the temperature of the mixture at a controlled rate. The resulting magnetic microspheres are micro‐sized (less than 8μm in diameter) and 80 percent of them are in the size ranging from 1 to 5 μm. Then, they were highly functionalized via ammonolysis reaction with ethylenediamine, and the surface amino‐modified magnetic microspheres were obtained. The morphology and properties of these magnetic microspheres were examined by SEM, TEM, VSM, and FT‐IR. Affinity ligand protein A (ProtA) was covalently immobilized to the amino‐modified magnetic microspheres by the glutaraldehyde method. These ProtA‐immobilized magnetic immunomicrospheres were effective for affinity bioseparation processes, as was demonstrated by the efficient immunoaffinity purification of antibodies IgG2a (22mg per gram of microspheres) from mouse ascites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2205–2211, 2004     

Foaming and chain extension of completely biodegradable poly(propylene carbonate) using DPT as blowing agent

Completely biodegradable foams of poly(propylene carbonate) (PPC) derived from carbon dioxide and propylene oxide were fabricated using N, N′-dinitroso pentamethylene tetramine (DPT) as chemical blowing agent, and urea as the activator to lower the decomposition temperature of DPT. Thermal decomposition behavior and gas evolution behavior of the DPT composite with various urea to DPT ratios were investigated to optimize the composition of the blowing agent. The formulation of blowing agent mixture and foaming condition, the foam morphologies, the molecular weight change, as well as the mechanical properties of produced PPC foams were studied extensively. The experimental results demonstrated that the greatest blowing ratio of 14.8 can be afforded in case 12 phr blowing agent was used at 170 °C for 30 min. Gel permeation chromatography (GPC) and thermal analysis revealed that DPT acted as both chain-extension agent and blowing agent for PPC matrix. The molecular weight of PPC subjected to foaming increased by 76%. The foamed PPC exhibited superior mechanical properties and can be used as packaging material for many practical applications.     

A perceptual evaluation of grating frequencies and velocities in the analysis of dynamic images

Dynamic images that possess beauty and are user-friendly can increase the use of digital technology. In addition to information conveyance, dynamic images also act as a communication bridge in the human–machine interface. Dynamic images are widely used in the application of digital media. Therefore, understanding the visual effects of dynamic images on viewers is a very important issue. From a visual communication design perspective, dynamic images influence not only image quality, but also the viewers’ perception and impression of the displayed image. In the contemporary age characterized by universal usage of dynamic images, designers should attain synchronized knowledge and understanding of relevant media technology so as to present preferred design quality in the management of digital design such as animation design, Web page design, multimedia design, and so on. The current study noted that psychological effects such as viewers’ visual attention, preferences, and understanding were more important than image quality. Therefore, this study adopted the viewpoint of “visual design” and conducted a perceptual evaluation of grating frequency and grating velocity. The pair-comparison method and scale method were adopted in the research methodology to simplify perceptual evaluations and enhance their validity. The purpose of this study was: (1) To propose recommendations for displaying dynamic images and improving image performance using perceptual evaluation methods. (2) To examine the influence of psychological factors on viewer’s comfort when they experience dynamic images. (3) To identify the best grating feature combinations that meet viewer’s psychological characteristics and propose recommendations for dynamic images design. The study concludes that it is useful to establish criteria for evaluating users’ perception and to, develop perceptual evaluations of dynamic images. It is recommended that designers find a balance between watching a moving imaging display “clearly” and watching it “comfortably” for successful reception by the viewer.     

Development of polarization ratio model for sea surface wind field retrieval from TerraSAR-X HH polarization data

In this article, the polarization ratio (PR) of TerraSAR-X (TS-X) vertical–vertical (VV) and horizontal–horizontal (HH) polarization data acquired over the ocean is investigated. Similar to the PR of C-band synthetic aperture radar (SAR), the PR of X-band SAR data also shows significant dependence on incidence angle. The normalized radar cross-section (NRCS) in VV polarization data is generally larger than that in HH polarization for incidence angles above 23°. Based on the analysis, two PR models proposed for C-band SAR were retuned using TS-X dual-polarization data. A new PR model, called X-PR hereafter, is proposed as well to convert the NRCS of TS-X in HH polarization to that in VV polarization. By using the developed geophysical model functions of XMOD1 and XMOD2 and the tuned PR models, the sea surface field is retrieved from the TS-X data in HH polarization. The comparisons with in situ buoy measurements show that the combination of XMOD2 and X-PR models yields a good retrieval with a root mean square error (RMSE) of 2.03 m s^–1 and scatter index (SI) of 22.4%. A further comparison with a high-resolution analysis wind model in the North Sea is also presented, which shows better agreement with RMSE of 1.76 m s^–1 and SI of 20.3%. We also find that the difference between the fitting of the X-PR model and the PR derived from TS-X dual-polarization data is close to a constant. By adding the constant to the X-PR model, the accuracy of HH polarization sea surface wind speed is further improved with the bias reduced by 0.3 m s^–1. A case acquired at the offshore wind farm in the East China Sea further demonstrates that the improvement tends to be more effective for incidence angles above 40°.     

压痕残余应力对氮化硅基复合材料阻力曲线行为的影响

通过压痕小裂纹直接量测法获得了ＴｉＣ，ＴｉＮ／Ｓｉ３Ｎ４复合材料的阻力曲线，采用更具合理性的指数经验公式拟合处理实验数据，初步探讨了Ｋ∞，Ｋ＾＊Ｒ，ΔＣ，等参数的物理意义。对压痕残余应力消除前 实验结果进行比较，发现压痕残余应力的消除，提高了材料的极限断裂韧性值Ｋ＾＊Ｒ，却大大减少了裂纹稳态生长的容限，使得材料的脆性行为更为突出。