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分析了喷雾干燥技术的应用现状,指出了喷雾干燥技术在功能性产品制备方面的重要作用。以产品质量作为最终的目标函数,对喷雾干燥技术提出了更高的要求,特别是利用喷雾干燥技术制备高品质功能性材料,要求喷雾干燥技术的内涵更丰富,与交叉学科的联系更广泛。介绍了以喷雾干燥技术为平台的微胶囊制备、复合离子制备、超细化离子制备、喷雾热解法等新方法的基本原理以及制备实例。指出了喷雾干燥技术新的研究发展方向。 相似文献
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纳米SiO2水溶胶的制备技术研究及应用 总被引:2,自引:0,他引:2
分别介绍了分散法与凝聚法制备纳米SiO2水溶胶的制备技术以及SiO2水溶胶在工业中的应用。分析了分散法、凝聚法中的离子交换法和酸盐水解法各自的反应原理、工艺流程及特点,列出了3种方法制备出的SiO2水溶胶的性能,对比得出了3种方法的优缺点。 相似文献
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纳米技术和纳米高分子复合材料 总被引:2,自引:0,他引:2
华道本 《现代塑料加工应用》1999,11(6):52-56
介绍了纳米粒子的特性、制备方法及其用于聚合物纳米复合材料的研究开发现状 ,重点讨论和比较了化学气相沉积法 ,液相化学合成法、固体法及聚合物法等制备方法的优缺点 ,并展望了纳米材料的发展前景 相似文献
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阐述了磷酸二氢钾的主要制备方法——中和法、直接法、萃取法、复分解法、离子交换法及电解法。通过比较各种方法的生产流程、原料消耗、生产成本、操作及产品质量等,认为萃取法、复分解法是目前较先进、具有发展前途的工业生产方法。 相似文献
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A method is proposed to determine optimal multiperiod operation policies for binary and general multicomponent batch distillation of a given feed mixture, with several main products and intermediate off-specification cuts. A two-level optimal control formulation is presented so as to maximize a general profit function for the multiperiod operation, subject to general constraints. The solution of this problem determines the optimal amount of each main and off cut, the optimal duration of each distillation step and the optimal reflux ratio profiles during each production period. The outer level optimization maximizes the profit function by manipulating carefully selected decision variables. These are chosen in such a manner that the need of specifying the mole fractions of all the components in the products, as required by previous methods is avoided. For values of the decision variables fixed by the outer loop, the multiperiod operation is decomposed into a sequence of independent optimal control problems, one for each production step. In the inner loop, a minimum time problem is then solved for each step to generate the optimal reflux ratio values, reflux switching times and duration of the step. The procedure permits the use of very general distillation models described by differential and algebraic equations, including rigorous thermodynamics if desired. The model equations are integrated by using an efficient Gear's type method, the inner loop optimal control problems are solved using a variational method, and all optimisations are solved using a robust and efficient successive quadratic programming code (Chen, Ph.D. Thesis, Imperial College, 1988).
Several example problems (involving binary and multicomponent mixtures) are used to demonstrate the idea and to show the effect of the cost functions used (in particular the value of the main products) on the optimal solutions. 相似文献
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A new method is proposed for generating a sequence of sparse approximation to the second-derivative matrix. The method uses the Powell-Symmetric-Broyden (PSB) formula in an implicit fashion to generate such a sequence of matrices. It is closely related to a method recently suggested by Toint.The main result of the new method is that we do not have to solve an associated linear system of equations at each step. Preliminary numerical test are very encouraging. 相似文献
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双钙钛矿型复合氧化物是一种新型的无机非金属材料,在电磁学和催化等方面具有好的应用前景,近年来引起了研究者极大的关注。本文介绍了双钙钛矿型复合氧化物A2B'B'O6的结构以及目前国内外传统和最新的合成方法。在结构上,单双钙钛矿型复合氧化物有相同点也有不同点,它们都具有稳定的骨架结构,最大的不同是双钙钛矿结构中B位原子的八面体结构由B'O6和B'O6交替排列而成,形成B'-O-B'的结合,从而产生了超交换作用。传统的合成方法着重介绍了高温固相法、溶胶-凝胶法和水热合成法;最新的合成方法主要叙述了微波烧结法、溶胶-凝胶自燃法、化学溶液沉积法、静电纺丝法、冷冻干燥法、非晶态合金法和脉冲激光沉积法。本文针对每一种方法的合成步骤及主要特征进行了详细阐述,对未来的双钙钛矿合成方法研究进行了展望,指出探索研发更加优越的合成方法是未来的研究热点。 相似文献
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介绍振动测试的重要意义和904数据采集器的使用方法及在各主要设备振动测试中的应用,阐述了机械振动的分析方法和对设备检修的指导作用。 相似文献
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Alexander Vikhansky 《Chemical engineering science》2005,60(4):963-967
A Monte Carlo stochastic simulation algorithm based on a single-particle method is suggested to describe steady-state particle coagulation processes. The method does not require any information on nearby particles; instead a fictitious coalescence partner with a given size is generated. The main drawback that limited applicability of this method in the past was that for each control volume the particle size distribution function had to be sampled and stored. In the present study we applied a discrete representation of the distribution function that requires only small memory resources and allows fast updating. 相似文献
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本文提出单点校正因子迭代法,改进了气相色谱测定涂料中水的定量分析方法,并对部分实验操作步骤进行了改进。用改进后的气相色谱法测定了16个水性涂料样品的水含量,对单点校正因子法、单点校正因子迭代法、卡尔-费休滴定法、气压法测定结果进行了比较。实验结果表叫,经过改进的气相色谱单点校正因子迭代法明显优于单点校正因子法,与卡尔-费休滴定法、气压法测定结果有可比性。对改进后的气相色谱法测量不确定度进行了评估。测量误差的主要来源是样品校正曲线拟合误差、样品测定重复性标准偏差。测试各环节的不确定度分量合成计算数据表明,气相色谱法测定水性涂料中水的分析结果标准相对不确定度为0.033。 相似文献