Degree of crosslinking and mechanical properties of crosslinked poly(vinyl alcohol) beads for use in solid-phase organic synthesis

The limited swellability in polar media of the commonly used polystyrene/divinylbenzene (PS-DVB) support materials for solid-phase organic synthesis has led to the development of novel, highly swellable hydrophilic gels designed for use in aqueous or polar media. Poly(vinyl alcohol) beads crosslinked with epichlorohydrin (PVA-EP) were prepared by a two-step inverse-suspension polymerization method. While it is known that the morphology of the resulting beads can be controlled by the ratio of EP versus PVA as well as by the pre-crosslinking time, the actual degree of crosslinking of the beads and their mechanical properties remain unknown. It is therefore the purpose of this study to evaluate the actual degree of crosslinking of beads prepared with different quantities of crosslinker in the feed by spectroscopic (Raman, nuclear magnetic resonance) and chemical (functional group loading) methods. The mechanical properties of these swollen PVA-EP beads will be evaluated by single-bead unconfined compression in solvents such as water, N,N-dimethylformamide (DMF), and tetrahydrofuran (THF) and compared to model PS-DVB beads commonly used for solid phase synthesis.     

三乙醇胺系矿渣复合助磨剂的研究

采用了数种三乙醇胺系复合助磨剂,在相同的粉磨条件下与矿渣共磨,每隔0.5h测定其比表面积并与空白样品对比;然后对所得矿粉用图像分析仪和扫描电镜进行了形貌分析;同时研究了三乙醇胺系复合助磨剂对矿渣-水泥体系标准稠度用水量、凝结时间和胶砂强度等各项性能的影响。结果表明三乙醇胺系复合助磨剂对矿渣的助磨效果好于单一助磨剂,且对矿渣-水泥体系各项性能无不良影响。     

立磨矿渣水泥生产线的建设

立磨技术已在水泥、矿渣粉磨领域得到成功的应用。国内只有部分水泥厂使用立磨粉磨原料和煤,用于水泥粉磨较少,特别是国产立磨尚无成功粉磨较高磨蚀性的水泥、矿渣的实例。目前高质量矿渣水泥的优越性逐渐被人们所认识,采用屯磨分别粉磨矿渣和熟料生产矿渣水泥能更有效地利用矿渣,生产过程高效、节能。为此介绍近几年来此类生产线建设的主要方案、建设经验,以期使行业对目前采用立磨分别粉磨矿渣、熟料生产优质矿渣水泥生产线建设的基本情况有进一步的了解。     

Alcohol consumption detection through behavioural analysis using intelligent systems

We describe in this paper a new methodology for blood alcohol content (BAC) estimation of a subject. Rather than using external devices to determine the BAC value of a subject, we perform a behaviour analysis of this subject using intelligent systems. We monitor the user’s actions in an ordinary task and label those data to various measured BAC values. The obtained data-set is then used to train learning systems to detect alcoholic consumption and perform BAC estimation. We obtain good results on a mono-user base, and lower results with multiple users. We improve the results by combining multiple classifiers and regression algorithms.     

水泥棒磨机预粉磨技术的增产节能效果

随着水泥工业结构调整，传统的一级圈流短磨水泥粉磨系统已经难以满足高产、优质、低耗的产业政策要求，必须进行必要的技术改造。文章分析了一级圈流磨存在的技术问题及其产生原因，介绍了对其实施增产节能改造的系统工艺技术方案和主机设备的内部结构改造方案。从两个厂的改造实施情况看，技改效果显著。     

粗品四氢呋喃的除醇与抗氧化技术

介绍了粗品四氢呋喃的除醇技术，过氧化物的生成机理与抗氧化技术。     

AA-MA共聚物制备工艺对助磨作用影响的研究

采用溶液聚合的方法,制备了丙烯酸(AA)、马来酸酐(MA)聚合物钠盐,系统地研究了单体种类、用量、反应温度、引发剂种类和浓度等助磨剂合成工艺对其助磨效果的影响规律.结果表明:所制备的助磨剂对石英、滑石和锆英石等硬质陶瓷原料具有明显的助磨效果,优于传统的工业助磨剂.较佳的助磨剂制备工艺为:以丙烯酸为单体,过硫酸胺-亚硫酸氢钠为引发剂,MA∶AA=2∶8(wt%);反应温度为65℃;丙烯酸溶液质量百分比浓度为2%;反应时间为4h;引发剂过硫酸胺 亚硫酸氢钠质量百分比为2%.     

Water sorption of poly(vinyl alcohol)/ poly(diallyldimethylammonium chloride) interpenetrating polymer network hydrogels

Temperature‐responsive interpenetrating polymer network (IPN) hydrogels constructed with poly(vinyl alcohol) and poly(diallyldimethylammonium chloride) using the sequential IPN method were studied. The characteristics of IPN hydrogels were investigated using the dynamic vapor sorption system. IPN hydrogels exhibited a relatively high sorption ratio, 180–360% at room temperature. The sorption ratio of hydrogels depended on temperature. Diffusion coefficients were calculated according to the Fickian Law at several temperatures. The apparent activation energy was 5.43 kJ mol^?1, which corresponds to typical diffusion processes. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1389–1392, 2003     

提高炼厂气综合利用水平的途径

公司将进行催化裂化装置、气体分馏装置改造。预计改造后的丙烯产量将达到5．0万t／a，丁烯等C4产品大大增加。聚丙烯是公司目前丙烯化工利用的唯一产品，年产量2万t，C4的化工利用尚属空白。因此开辟过剩丙烯利用新途径，带动C4产业发展，形成化工产业链，提高公司炼厂气的综合利用水平，具有重要意义。合成异丙醇或环氧丙烷，就是这样一个突破口。     

Ethanol production from raw starch by a recombinant yeast having saccharification and fermentation activities

In order to develop a method for converting raw starch into ethanol efficiently, direct fermentation of ozonized raw starch using a recombinant yeast was investigated. Ozonolysis was carried out as a pretreatment to convert raw starch into ethanol rapidly and efficiently, and then the effect of the ozone degradation conditions on the degree of polymerization and the amount of amylose in a raw starch was determined. Since the degree of polymerization was low and the amount of amylose was high, raw starch treated with an ozone concentration of 40 gm^?3 and an ozonation time of 30 min was the material chosen for alcohol fermentation. Though the recombinant yeast could not convert the untreated raw starch, it converted the soluble starch and the ozonized raw starch at a comparatively high yield into ethanol. About 56% of the ozonized raw starch decomposed, and the ethanol concentration obtained from the ozonized raw starch was markedly greater than that obtained from untreated raw starch. The dynamic behavior of cell growth, substrate degradation, and ethanol production was examined in a continuous culture under various dilution rates, and the optimal dilution rate, ie 0.15 h^?1, was determined for maximizing the ethanol productivity (amount of ethanol produced per unit time). © 2002 Society of Chemical Industry