SO_4~(2-)/ZrO_2-Al_2O_3催化合成脂肪酸季戊四醇酯的研究

以脂肪酸和季戊四醇为原料,三甲苯为带水剂,SO42-/ZrO2-Al2O3固体超强酸催化,合成脂肪酸季戊四醇酯。实验结果表明,控制酯化温度(180～200)℃、醇酸物质的量比为1∶5.6、催化剂加入量为原料总量的0.9%和反应时间为4h时,可获得最佳反应结果,酯化率达99.88%。IR谱表明,产品中羟基吸收峰基本消失,证明酯化反应较充分和完全。     

Reaction-formed W2B5/C composites with high performance

Highly densified W₂B₅/C composites with W₂B₅ content from 30 to 70 vol% were fabricated by reaction hot pressing of the powder mixture of B₄C, WC and carbon black. The reaction products were identified by XRD analysis to consist of only W₂B₅ and carbon, regardless of carbon content. The reaction formed composites have excellent mechanical properties (the maximum flexural strength and fracture toughness of 786 MPa and 8.9 MPa m^1/2 respectively), electrical conductivity (the highest electrical conductivity of 1.64 × 10⁶ Ω⁻¹ m⁻¹), and resistance to both wear and oxidation because of the presence of the plate-like W₂B₅ grains. In this paper, the preparation, microstructure and properties of this new composite are investigated, and the strengthening, toughening, conduction mechanisms are discussed.     

Morphology and characterization of conductive films based on polyaniline‐coated polystyrene latexes

The polyaniline (PANI)‐coated polystyrene (PS) latexes were synthesized, and the electrically conductive films were prepared thereafter. The weight ratio of PANI was 5%. Thermal analysis of the latices was performed using DSC and TGA. In this study, the electrically conductive films were prepared above the PS glass transition temperature (T_g). During the film formation, the effects of the annealing temperature and atmosphere (air or N₂) on the film resistance were investigated. In addition, the film morphology was observed utilizing scanning electron microscopy. The film resistance decreased in the initial heating stage due to the increasing temperature and the compaction of film. Then the film resistance increased with further annealing due to the aging of PANI. Typically, the film resistance was about 6000 Ω/sq, and the conductivity was 0.3 S/cm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5406–5413, 2006     

Nanocrystalline CeO2 in SBA-15: Performance of Pt/CeO2/SBA-15 Catalyst for Water-gas-shift Reaction

CeO₂ particles confined within the pores of an SBA-15 mesoporous silica host were prepared by incipient wetness impregnation (IMP) and deposition precipitation (DP) methods. The materials were characterized by XRD, N₂-adsorption and temperature programmed reduction (TPR) to evaluate the structure, texture, and redox properties. The preparation procedure had significant impact on the assembling mode of CeO₂ inside the SBA-15 mesopores. A high dispersion of CeO₂ particles was achieved via DP, whereas the dispersion of CeO₂ prepared by IMP was found to be inhomogeneous and CeO₂ partially blocked the pores. The CO conversion in the water-gas-shift reaction was enhanced over 1 wt% Pt supported on CeO₂-modified SBA-15 obtained by DP.     

Response surface methodology study on electrochemical adsorption regeneration of water-based drilling fluid waste

ABSTRACT

This study explores an electrochemical adsorption method on the regeneration of aqueous drilling fluid waste. Response surface analysis was applied to investigating the electrochemical factors on the adsorption performance. The response surface polynomial model optimized the preferred electrochemical adsorption conditions with adsorption time of 20 min, spacing electrodes of 5 cm, adsorption concentration of 5% and NaCl concentration of 2 g/L. The model calculated electrochemical adsorption amount of drilling fluid showed only 1.3% deviation from the experimental results. Thus, the model could provide effective support for the device design and application of drilling fluid electrochemical adsorption process.     

b型流感嗜血杆菌多糖结合疫苗的研制

［摘 要］目的 研制b型流感嗜血杆菌（Hib）结合疫苗并考察其稳定性。方法 用溴化氰活化提纯Hib荚膜多糖抗原，通过己二酰肼（ADH）与破伤风类毒素（TT）蛋白共价结合，制备b型流感嗜血杆菌结合物，并考察放置在2～8℃及室温9个月和37℃　3个月后的稳定性。结果 用本工艺提取的多糖，合成的多糖衍生物，多糖蛋白结合物的化学组成及结构特性均达到了国外同类产品的质控要求。结合物在2～8℃及室温放置9个月后基本无降解。结论 为临床评价Hib结合疫苗的安全性和保护效果及确定效期提供了实验基础。     

基于校企融合创新提升高职教师应用科研能力的实践研究

提高高职院校教师的应用科研能力是提高教师整体素质、培养优秀人才的有效途径。论文通过创新实施“ICT行业应用创新基地”的建设实践,采取深化创新基地的科研机制、强化团队建设以及推进应用科研与人才培养的融合创新等举措,形成科研与教学协同发展的职业教育新模式,有效提升高职教师的应用科研能力。     

塑料啤酒瓶开发现状

介绍了塑料啤酒瓶的优点,详细介绍了各种以PET为基础的改性啤酒瓶材料,并列举了大量的开发实例。     

基于神经网络和遗传算法的薄壳件注塑成型工艺参数优化

建立了基于神经网络和遗传算法并结合正交试验的薄壳件注塑成型工艺参数优化系统。正交试验法用来设计神经网络的训练样本，人工神经网络有效的创建了翘曲预测模型；遗传算法完成了对影响薄壳塑件翘曲变形的工艺参数（模具温度、注射温度、注射压力、保压时间、保压压力和冷却时间等）的优化，并计算出了它们的优化值。按该参数进行试验，效果良好，可以有效地减小薄壳塑件翘曲变形，其试验数值与计算数值基本相符，说明所提出的方法是可行的。     

C语言程序设计课程教学方法实践

针对C语言教学中存在的问题与现状,介绍如何通过改进教学方式方法,激发学生学习兴趣,取得较好的教学效果的教学实践。