超微粒子合成方法的发展动向

全面系统地介绍了国内外合成超微粒子的基本原理和方法,并简述了超微粒子的主要品种和应用前景。     

并行计算在分子模拟中的应用

简要介绍了并行计算机的发展背景,结合网络中心搭建的Linux cluster并行机说明了此类并行机的基本架 构。对三款常用的并行分子模拟软件进行了评述,比较了不同架构并行机的运行效率。对其中一款软件在此并行 机上进行了实测,并对并行机和分子模拟软件的发展进行了合理的预测。     

CFD并行计算技术的研究进展

综述了并行计算技术在计算流体动力学(CFD)中的研究及应用进展,介绍了CFD并行化的关键技术研究近况,包括网格处理技术、并行化算法技术以及并行计算平台的研究进展.最后讨论了CFD并行技术的发展方向.     

负载药物纳米粒子制备方法和应用的研究进展

文章通过对近几年有关载药纳米粒子的研究,总结了负载药物纳米粒子的一些制备方法,包括溶剂挥发法、纳米沉淀法、微乳液法等,同时也对纳米粒子的应用方向进行了阐释和说明,展示了负载药物的纳米粒子巨大的研究价值和广阔的利用空间。     

高分子／碳酸钙纳米粒子、其功能型粒子及其制备方法

本发明涉及高分子／碳酸钙纳米粒子、其功能型粒子及其制备方法。本发明以纳米碳酸钙粒子、烯基单体、偶联剂及含有非烯基官能团的烯基单体为原料，通过以水为介质的微乳液聚合制备高分子／碳酸钙纳米复合粒子和功能型高分子／碳酸钙纳米复合粒子。前者具有以纳米碳酸钙为核、聚合物为壳、核壳间具有化学键接的球形粒子特征，粒径均一，且小于100nm;后者外表面还带有非烯基官能团。     

并行计算在化工系统中的应用

化工过程的模拟与优化得到了越来越广泛的应用,随着计算机技术的迅速发展,采用并行计算提高化工系统中计算能力已成必然.本文介绍了目前比较流行的PC机群系统及利用并行算法实现化工系统中的模拟与优化.     

PET凝胶粒子的行为特征研究与应用

鲁奇压片法可以半定量地表征ＰＥＴ切片或试样中的凝胶粒子含量,而切片机切片法只是表征了普通凝胶和陈凝胶含量,没有表征出嫩凝胶的含量。鲁奇法和切片法都需改进才能表征ＰＥＴ切片中的凝胶含量。研究结果认为：用切片机切片制试样并解决试片厚度的影响,用热处理使嫩凝胶成熟为普通凝胶,可解决全面测量凝胶的困难。嫩凝胶和普通凝胶可转化为陈凝胶     

纳米银粒子制备及应用研究进展

综述了制备纳米银粒子的方法,主要包括液相化学还原法,电化学还原法、光化学还原法和分子自组装等,分析比较了这些方法的基本原理、制备过程及优缺点,阐述了纳米银粒子在化学反应,光学领域及抗菌等领域的应用.     

管壳式换热器数值模拟的并行计算技术研究

利用并行计算原理,在FLUENT软件中对GAMBIT建模的管壳式换热器进行了数值模拟.通过对3种组合计算平台所消耗的机时进行比较,得到并行加速比和并行效率的规律,为复杂的管壳式换热器壳程设计的工程仿真和优化提供了一种新的处理方法.     

金纳米粒子的应用研究进展

近年来,由于金纳米粒子独特的物理化学性质以及良好的生物相容性和生物安全性,吸引越来越多的科研工作者对其展开广泛的研究和开发。从金纳米粒子的合成方法、特性以及应用开发等方面的对金纳米粒子近年来的研究进展进行了比较详细的综述。     

A multi-thread parallel computation method for dynamic simulation of molecular weight distribution of multisite polymerization

Molecular weight distribution (MWD) is an important quality index of polymer products. Many methods have been proposed to dynamically simulate the MWD of polymerization, but these methods are normally designed for serial computations. In this paper, a multi-thread parallel computation method was proposed for multisite free-radical polymerization. Analysis of the relationship among different subtasks revealed a combined parallel strategy by fully exploiting the parallel feature of the process. A good performance was obtained to accelerate the dynamic simulation of MWD based on Flory method. We theoretically analyzed the speedup ratio (SR) and parallel efficiency (PE). Results showed that software algorithm and hardware configuration exhibited a good match. The efficiency of the proposed parallel method was presented through industrial slurry processes that used high-density polyethylene (HDPE).     

基于粒子群算法的生活垃圾高热值成分热解动力学特性研究

以硬纸板、橡胶、松木和尼龙等典型生活垃圾(MSW)成分为研究对象,采用热重分析获得了不同升温速率下(15,40和200℃/min)各成分的热解失重特性。基于各生活垃圾成分失重曲线的特征,分别建立了有限平行反应模型,通过粒子群算法计算相应的动力学参数,并进行了交叉验证。研究表明,对于组成复杂、特性各异的生活垃圾成分,基于粒子群算法的有限平行反应模型既能准确反映各成分热解失重曲线的复杂峰结构,也能有效预测不同升温速率下失重特性的变化。     

混合粒子群优化算法及其应用

提出了一种通过改进全局最优位置粒子寻优策略而提高粒子群优化计算效率的混合粒子群优化算法。针对流程工业典型设备的状态跟踪预报等有计算时间限制的优化问题,混合粒子群优化算法在不改变原有粒子群粒子寻优策略的前提下,将粒子群整体已搜寻到的全局最优位置看作一个特殊的粒子,令该粒子执行梯度下降寻优的寻优策略。在粒子群的寻优迭代计算中增加全局最优位置粒子单独的梯度下降寻优过程,从而将粒子群优化算法的全局寻优特性与梯度下降算法的邻域寻优特性相结合,以提高粒子群优化算法的整体寻优效率,进而缩短寻优计算的时间。针对流程工业典型设备的实际应用表明,混合粒子群优化算法能够减少寻优迭代次数,进而缩短优化计算时间。     

并加法制备超细二氧化硅

以Na2O·3.27SiO2和硫酸为原料,采用并加法制备形状较好、粒度分布均匀、孔径在2~20 nm的超细二氧化硅。用吸油值、BET、SEM、FT-IR、XRD等方法对其进行表征,并考察了原料加入速度、表面活性剂、洗涤剂等对制备二氧化硅粉体的影响。结果表明,最佳反应条件为：Na2O·3.27SiO2加入速度为70 r/min,无表面活性剂加入,使用乙醇洗涤,85 ℃干燥2 h后100 ℃干燥2 h。在最佳反应条件下制得的二氧化硅粉体颗粒大部分呈圆形或椭圆形,形状较好,粒度分布比较均匀,比表面积为222.7 m2/g,平均孔径为16.95 nm。     

基于小波包分析和K-OPLS的集成方法在颗粒粒径分布检测中的应用

颗粒粒径分布的实时在线检测对于调控气固流化床中颗粒的流化特性具有重要意义。基于混料均匀设计法安排实验,以声发射(AE)技术为检测手段,结合小波包分析,提出采用K-OPLS方法构建颗粒粒径分布的声信号预测模型,定量描述小波包能量特征与颗粒粒径分布的非线性变化规律。实验结果显示,留一交叉验证法的均方根误差(RMSE)仅为0.063,表明基于K-OPLS的颗粒粒径分布声信号预测模型能准确测量气固流化床中颗粒的粒径分布,具有良好的工业应用前景。     

Constrained particle filtering methods for state estimation of nonlinear process

Increasingly in practical applications, nonlinearity, non‐Gaussianity, and constraint must be considered to obtain good state estimation. A constrained particle filter (PF) approach for state estimation, which involves three alternative strategies to impose the constraints on the prior particles, posterior particles, and state estimation has been proposed. First, to impose constraints on prior particles, a constrained Gibbs sampling method with a constrained inverse transform sampling is proposed to restrict sampling within the constraint region under cases of both univariate and coupling constraints. Second, to ensure validity of posterior particles, resampling is confined to the valid prior particles and the violated ones are discarded, which results in a similar formulation as the existing acceptance/rejection constrained PF method in literature. Third, if the state estimation violates the constraint, different from the existing methods that either discard all violated particles or accept all of them by projecting them onto the constraint region, the proposed method makes a balance between the prior and the likelihood function by adjusting the weights of violated and valid particles, respectively. Compared with the existing methods, the proposed method provides better physical interpretation and involves no restrictive assumptions about the distributions. Simulation results demonstrate effectiveness of the proposed methods. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2072–2082, 2014     

Correlations for the particle deposition rate accounting for lift forces and hydrodynamic mobility reduction

A numerical procedure is presented which allows one to predict the deposition rate of microparticles suspended in a liquid flow onto the confining walls. Particle transport is not only diffusive but also affected by hydrodynamically induced lift force and reduced particle mobility. An appropriate expression for the lift‐induced migration is introduced into the numerical procedure. Its results agree quanititatively with previously published experimental data showing a significant effect of lift‐induced particle transport. Based on the numerical results algebraic correlations are obtained, which enable to calculate the particle deposition rate in situations where lift forces and mobility reduction diminishes the particle deposition rate.     

Coupling of smoothed particle hydrodynamics and finite volume method for two-dimensional spouted beds

A coupled method with smoothed particle hydrodynamics (SPH) and finite volume method (FVM) is proposed in this work for the simulation of the particle dynamics in two-dimensional spouted beds. Based on the pseudo-fluid model, SPH is used for discrete phase to trace the movement of each individual particle and FVM for continue phase to compute the turbulent fluid. Two phases are coupled through effects of drag force, gas pressure and volume fraction of each phase. A two-dimensional tapered-based spouted bed is chosen as a case study to demonstrate the performance of the SPH–FVM coupled algorithm. The simulation results show a good agreement with the experimental data and other simulation results by the two-fluid model and discrete element method in the literature. The spouted shape, time-averaged particle velocities and particle vertical velocities in the spout are analyzed and the distribution of gas flow field and turbulent kinetic energy are then discussed. It indicates that the present method is more suitable to study the fluidization within the spouted beds.     

试论沉降法测定颗粒粒度及其分布

颗粒的粒度及其分布显著影响粉末的性质和用途，为了掌握生产中产品的质量，必须对粉末进行粒度分布的检测。详细介绍了沉降法的基本原理，实验方法、步骤和结果处理。试验和生产应用表明，粒度测定的方法多种多样，沉降法以其原理简单、易于操作而被广泛采用。     

基准轴线投测后的检测精度要求和归化计算

结合高层建筑工程施工的生产实际,在施工条件限制的情况下,以15″或20″作为投测后三点是否在一直线上的限差要求来推证投测基准轴线的检测精度指标,以及为提高轴线投测精度进行归化改正的计算简捷公式,并通过实例进行了验证分析,解决了高层建筑施工中基准轴线投测的实际问题。