High-performance dispersant of coal–water slurry synthesized from wheat straw alkali lignin

Environmental concerns have stimulated interest in utilizing plant-derived materials in various industrial fields. The main objective of the present study was to synthesize a new type of high-performance lignin series dispersant of coal–water slurry (CWS) from wheat straw alkali lignin (WAL), and determine the affecting factors in the reaction and the application performance for CWS preparation. The experimental results showed that the inherent viscosity and the sulfonic group content of the modified wheat straw alkali lignin (MSL) are the key factors affecting its dispersing effect for CWS. In the reaction, the reactant mass concentration and the sulfonating agent amount were changed to obtain the MSL with different inherent viscosities and sulfonic group contents, and the MSL with intermediate inherent viscosity (6.0 ml/g) and higher sulfonic group content (1.80 mmol g^− 1) was found to have excellent dispersing effect for CWS. The MSL obtained from optimized process was used as dispersant for CWS preparation, the studies of the properties of CWS showed that MSL has similar dispersing effect with naphtalenesulfonate–formaldehyde condensate, and far better dispersing effect than lignosulphonate. Recently this kind of new dispersant has been applied in several power plants in China.     

塑料挤出机主辅电机联动系统设计

本文在分析国内外挤出机生产线主辅电机同步联调特点的基础上,提出了一种实用的联调控制系统设计方案,控制系统设计采用纯硬件方式,可以广泛适用于国内未采用同步联调技术的挤出生产线,进行技术改造,对原有设备改动极小,具有很高的性能/价格比。     

牙舟泥哨

牙舟泥哨作为民间陶制玩具在数百年的发展中逐渐形成了自己的风格和个性，在造型、审美上带有独特黔南地方特色。本文从造型和审美的角度对牙舟泥哨进行了分析。     

Experimental Study on the Hydrodynamics and Mass Transfer Characteristics of Ultrasonic Loop Airlift Reactor

The promoting effect of ultrasonic wave on the hydrodynamics and mass transfer characteristics of the loop airlift reactor was studied. The gas holdup, liquid circulation velocity, mixing time and overall volumetric mass transfer coefficient were examined and compared, with and without ultrasonic wave in the reactor. The experimental results show that ultrasound has almost no notable effect on the gas holdup, but has a tendency to decrease gradually the liquid circulation velocity and increase the overall volumetric mass transfer coefficient; and the effect on the mixing time is relatively complex. At low superficial gas velocity, the low powered ultrasound promotes the radial mixing of fluid; with the ultrasonic power increasing, ultrasonic vibration obstructs the axial mixing of fluid. Moreover, the effect of ultrasonic wave on the mixing time gradually decreases with the increase in the superficial gas velocity. Therefore there exists an optimal ultrasonic power for hydrodynamics and mass transfer. Correlations were also proposed for the hydrodynamics and mass transfer characteristics of the reactor.     

以数学建模为切入口的大学 公共数学课程教学改革

分析了公共数学课程在大学本科课程体系中的地位与作用,阐述了数学建模对培养提高大学生综合素质及其对大学数学课程教学改革的推动作用。     

液压仿真技术的应用与发展

本文在简单回顾液压仿真技术的发展之后,着重介绍了仿真技术及其在液压领域的应用,论述了液压建模与仿真技术的方法和几个关键问题,并从不同的侧面介绍了一些软件,最后综述了液压仿真技术未来的发展趋势。     

基于Web的高校在线心理咨询系统设计

近几年,大学生心理健康问题已经成为无法回避的问题。由于心理咨询的特殊性,传统的咨询模式在洞察心理疾病、保护个人隐私和提高服务效益方面受到种种因素的制约。而基于Web的高校在线心理咨询系统是与现代IT技术密切结合的远程心理咨询系统,能够轻易地解决传统咨询模式存在的不足。既能实时为大学生提供比较专业的心理咨询服务,又能保护学生的隐私和维护自尊心,为提高他们主动接受咨询的积极性提供了全新的方式和途径。     

北京地区中小套型住宅居住需求及对策研究

通过对北京地区中小套型住宅居住实态调研结果进行数据统计分析,探讨了住户在住宅使用过程中存在的共性问题,分析了住户的使用需求,并提出了相应的合理化建议．文中还选取两个典型实例进行改造,为以后住宅改造与设计提供了一定的借鉴与参考．     

氮化铝纳米粉末的氧化特性研究

采用直流电弧等离子体蒸发－凝聚法制备了高纯氮化铝（ＡＩＮ）纳米粉末。粉末的平均晶粒度为５０ｎｍ，纯度大于９８％。借助Ｘ射线光电子能谱、化学分析和差热失重等测试手段，探索了ＡＩＮ纳米粉末的表面化学组成和氧化特性。研究结果表明，ＡＩＮ纳米粉末易吸湿氧化，大大降低了其纯度。ＡＩＮ纳米粉末表面的氧是以两种状态即物理吸附态和化合态存在。     

基于超网络的集成工艺决策与调度问题研究

针对多工艺产品的加工路线决策与车间调度方案不能同步制定的问题,在制造车间数字化背景下,提出集成车间不同要素信息的特征—工序—机器—工人的超网络结构,建立基于超网络的加工路线决策与车间调度模型,设计一种集成工艺决策与车间调度的两阶段混合遗传算法求解模型。在工艺决策阶段,设计特征—工序双层矩阵编码染色体保持加工路线的多样性,并在遗传算法的执行过程中使用变邻域搜索方法增强算法的局部搜索能力;在车间调度阶段,采用NSGA-Ⅱ算法优化调度模型,将得到的调度方案多目标值返回至工艺决策阶段用于加工路线的适应度评价。最后通过仿真实验验证了该算法的可行性与有效性。