红外测温技术在离心复合铸造轧辊生产上的应用

本文分析了离心复合铸造轧辊生产过程中离心机停机温度和时间对轧辊质量的影响 ,提出了用先进的红外测温技术来预报停机温度和时间 ,以实现微机监控适时停机 ,保证轧辊内外层熔合良好 ;同时指出了红外测温技术在离心复合铸造轧辊生产上的应用前景     

稀土含量对喷熔层组织及耐蚀性的影响

本文通过在镍基自熔合金粉末中加入不同含量的稀土，研究了稀土含量对喷熔层组织及耐蚀性的影响规律及其作用机制。结果表明，在喷熔材料中加入适量稀土，可使喷熔层组织细化、晶界净化，从而使腐蚀过程中的表面活性点减少，耐蚀性提高。     

汽车后市场准入门槛亟需设防

任何市场都是有规则的,没有标准的市场是短暂的.经销商要有一个好的经营环境,必须把这个门槛设好. 汽车后市场还需要准入门槛? 李庆云现任天津环渤海汽车城董事长并身兼天津市交易市场协会会长,在没有跨进汽车行业之前,一直觉得这样的问题多余:哪个行业没有准入门槛?等自己在天津建立环渤海汽车城之后,才意识到,中国的汽车后市场是多么需要"设防".     

Properties of poly(n‐butyl methacrylate) prepared by reverse atom transfer radical polymerization in an aqueous dispersed system

Reverse atom transfer radical polymerization (ATRP) of n‐butyl methacrylate (BMA) in waterborne media using Cu(II) complexes with azo initiators (i.e., reverse ATRP) was conducted. The influence of several factors, such as surfactant, catalyst, and reaction time, on the stability of the emulsion, the particle size, the morphology of the emulsion particles, and the control of the polymerization was investigated. The results showed great differences between ATRP and conventional emulsion polymerization, especially the nucleation mechanism and the kinetics. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1542–1547, 2003     

人胎盘泌乳素的提纯及裂解片断免疫学特性的研究

采用人胎盘泌乳素（hPL）-亲和层析和抗人血清抗体-亲和层析技术，从胎盘匀浆中提取hPL纯品，经圆盘电泳、免疫电泳及交叉试验证实为单一成分。溴化氰水解后的产物，以高效液相色谱分析。分离出7个肽链片断峰，分别用hPL和人生长激素（hGH）放免法检测其活性，其中第6肽链片断无hGH免疫活性，若用此片断制备特异抗体，可避免与hGH出现交叉反应。     

碱土金属在萃取剂与树脂间反应平衡常数的测定

研究了碱土金属离子在Ｄ００１树脂与８－羟基喹啉三氯甲烷溶液间的平衡常数Ｏ－ｔＫ的测定。其值依Ｍｇ、Ｃａ、Ｓｒ、Ｂａ次序减小。并得出萃取剂浓度［ＨＡ］。与金属离子在两相分配的关系。     

异丁烯两段催化氧化制甲基丙烯酸催化剂研究 Ⅰ．异丁烯气相氧化制甲基丙烯醛多元复合氧化物催化剂的研究

本文报导用于异丁烯（叔丁醇）选择氧化制ＭＡＬ（甲基丙烯醛）的多元复合氧化物催化剂的研究结果。同共沉淀法制备的催化剂的活性主要决定于其化学组成，同时受到制备条件的影响。最佳催化剂的主要物相组成为ＰｂＯ３，Ｂｉ２ＭｏＯ３．３、ＮｉＭｏＯ４、Ｓｂ２Ｏ３及ａ－Ｆｅ２Ｏ３小颗粒。在３５５℃，１０００～２５００ｈ－１空速范围，叔丁醇：水：空气＝１：３．３：７（摩尔比）的条件下可获得异丁烯转化率达９６％，ＭＡＬ选择性达８９％的结果。     

氯化聚丙烯改性胶粘剂的合成及粘附性能研究

以甲苯为溶剂，过氧化二苯甲酰(BP0)为引发剂，通过自由基聚合，采用甲基丙烯酸羟乙酯(HEMA)和苯乙烯(St)接枝改性氯化聚丙烯(CPP)。研究了不同苯乙烯用量、不同反应温度、不同反应时间、不同引发剂用量对改性氯化聚丙烯胶粘剂粘附性能的影响，得出较佳的工艺条件为反应温度90℃，反应时问2h，原料配比m(CPP)：m(HEMA)：m(St)：m(BPO)=50：0．5：0．6：0．15。     

PVA-based activated carbon fibers with lotus root-like axially porous structure

A novel method was developed for the fabrication of activated carbon fiber (ACF) with wet spinning polyvinyl alcohol (PVA) fibers as the precursors. Through a combination of preoxidation, dehydration, carbonization and activation under a certain tension, PVA-based ACFs (PVA-ACFs) with high yields and good mechanical properties were obtained. The surface and cross-section morphologies, pore structures, surface geometries, surface functional groups and crystal structures of the PVA-ACFs were characterized using field emission scanning electron microscopy, low temperature nitrogen adsorption, Fourier transformed infrared spectrophotometry, X-ray photoelectron spectroscopy and X-ray power diffraction. All the PVA-ACF samples prepared had lotus root-like axially meso- and macroporous structures with the domination of micropores. Fractal geometries of PVA-ACFs deduced from nitrogen adsorption isotherms indicates that capillary force dominated in the interactions between nitrogen and the PVA-ACFs. The surface functional groups of the PVA-ACFs depend on the activating agents. Graphitoidal crystal structures were observed for the PVA-ACFs. The small crystal size and short range ordering between the crystallites ensured a high specific surface area of the PVA-ACFs.     

Effect of Product Conductivity on Field-Activated Combustion Synthesis

Experimental and modeling results on the field-activated combustion synthesis (FACS) of Nb₅Si₃ are reported. In the absence of an electric field and without reactant preheating, Nb₅Si₃ cannot be prepared by self-propagating high-temperature synthesis (SHS). Under the influence of a field a self-sustaining combustion wave is established whose rate of propagation decreases with traveled distance. For relatively low field values, the wave propagation mode changes from a continuous (smooth) to a spin mode. The product of synthesis depends on the mode of propagation. Synthesis during continuous wave propagation results in the formation of Nb₅Si₃, primarily in the α-modification. In contrast, when the wave propagates in a spin mode, the product is NbSi₂ with unreacted niobium. The present observations demonstrate a case where the field effect is not localized, as was the case in previous studies. The difference in behavior is attributed to differences in the electrical conductivities of the product phases.