Flow and temperature patterns in an inductively coupled plasma reactor: Experimental measurements and CFD simulations

Measurements of temperature patterns in an inductively coupled plasma (ICP) have been carried out experimentally. Plasma torch was operated at different RF powers in the range of 3–14 kW at near atmospheric pressure and over a wide range of sheath gas flow rate (3–25 lpm). Measurements were made at five different axial positions in ICP torch. The chordal intensities were converted into a radial intensity profile by Abel Inversion technique. Typical radial temperature profile shows an off‐axis temperature peak, which shifts toward the wall as the power increases. Temperatures in the range of 6000–14,000 K were recorded by this method. The temperature profiles in the plasma reactor were simulated using computational fluid dynamics (CFD). A good agreement was found between the CFD predictions of the flow and temperature pattern with those published in the literature as well as the temperature profiles measured in the present work. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3647–3664, 2014     

LDA measurements and CFD simulations of an in‐line high shear mixer with ultrafine teeth

Hydrodynamics of a pilot‐scale in‐line high shear mixer (HSM) with double rows of ultrafine rotor and stator teeth, including the velocity profiles and power consumptions, were measured using laser Doppler anemometry and a torque transducer, respectively. Computational fluid dynamics simulations were conducted using the standard k‐ε turbulence model with first‐ and second‐order accuracy and large eddy simulation (LES) with the standard Smagorinsky–Lilly subgrid scale model. Predictive capabilities of the different turbulence models and discretization schemes were assessed based on the experimental data. It is found that the current LES can predict accurately the flow patterns for the strongly rotating and locally anisotropic turbulent flows in the complex in‐line HSM. The results obtained are fundamental to explore potential applications of the in‐line teethed HSMs to intensify chemical reaction processes. © 2013 American Institute of Chemical Engineers AIChE J, 60: 1143–1155, 2014     

准二维聚(环氧乙烷)超薄薄膜中线状和树枝状结晶生长的在线观察简

Crystal growth processes of poly（ethylene oxide） were followed from the original nucleation sites by using atomic force microscopy. Two distinct quasi-2-dimensional crystals about 4 nm thick were obtained from as-spun polymer ultrathin films： fibrous crystals, generated by the sheafing field via spin-coating, coexist with con- ventional dendrites. The growth of the two structures is dominated by diffusion limited aggregation, though the growth rate of the fibrous crystals is around one order of magnitude faster than that of the dendrites. The fibrous crystals are more stable than the dendritic ones.     

14.00R20 18PR TRY66全钢载重子午线轮胎的设计

介绍14.00R20 18PR TRY66全钢载重子午线轮胎的设计。结构设计:外直径1 237mm,断面宽373mm,行驶面宽度286mm,行驶面弧度高10.2mm,胎圈着合直径508mm,胎圈着合宽度267mm,断面水平轴位置(H1/H2)1.028,采用越野花纹,花纹深度25mm,花纹饱和度53.2%,花纹周节数42。施工设计:胎面采用两方两块设计,胎体采用0.25+6+12×0.225HT钢丝帘线,1#和2#带束层采用3+8×0.33ST钢丝帘线,3#带束层采用3×4×0.22HE钢丝帘线,0°带束层采用3×7×0.20HE钢丝帘线,采用三鼓式一次法成型机成型、热板双模硫化机硫化。成品性能试验结果表明,成品轮胎的外缘尺寸、强度性能和耐久性能均达到国家标准要求。     

基于改进型延时观测器的电热炉温度复合控制方法

电热炉温控系统自身具有大时滞和大惯性的特点,常规控制方法难以实现炉温预期的控制效果。针对此问题,提出一种基于改进型延时观测器的电热炉温度复合控制方法,将扰动观测器与延时观测器相结合,在消除系统集总扰动的同时,估计出时滞前的状态变量,简化滑模控制器的设计,提高系统的抗干扰能力,消除时滞危害。将所提控制方法与GPC控制、基于Smith预估器的模糊自适应PID控制进行仿真对比,结果表明：所提控制方案的响应速度更快,超调量几乎为零,抗干扰能力更强,鲁棒性更好。     

胜利油田稠油热采开发技术研究进展

针对胜利油田稠油油藏地质特点及开发难点,重点介绍了中深层特超稠油油藏、浅薄层超稠油油藏、敏感性稠油油藏和低渗透稠油油藏等复杂稠油油藏的开发技术,并对其提高采收率机理和现场应用效果进行了总结概括。在此基础上,根据目前研究进展指出了稠油热采开发技术的发展方向,重点介绍了超深层低渗稠油和浅薄层特超稠油的开发技术及其应用。     

型钢-钢纤维混凝土组合梁抗弯性能试验研究

为解决型钢混凝土结构中型钢与钢筋相互干扰、混凝土浇筑困难等施工难题,将型钢混凝土梁中的钢筋笼完全或部分替换成钢纤维,形成型钢–钢纤维混凝土组合梁。完成12个型钢钢纤维混凝土组合梁和1个未添加钢纤维、未设置钢筋笼对比试件的抗弯性能试验。主要研究钢纤维掺量、型钢配钢率、箍筋设置和主筋设置对抗弯性能的影响。增加钢纤维用量能够在一定程度上提高承载力,其影响程度与型钢配钢率有重要的相关性,型钢配钢率越大,钢纤维的影响越突出。纵筋的设置能够大幅提升承载力,箍筋和钢纤维能够使纵筋对承载力的增强效果更为突出。试验结果表明：在相似用钢量的情况下,无配筋的型钢钢纤维混凝土组合梁不但能够解决型钢混凝土结构的施工困难,而且能够大幅提升延性性能,但由于未配置纵筋,正截面抗弯能力有所削弱;减小保护层厚度,提高型钢配钢率,能够充分发挥型钢翼缘良好的抗弯能力,弥补未设置主筋对承载力的影响,同时增加钢纤维用量,解决因保护层减小而导致的钢与混凝土界面黏结性能变差的问题;在设置钢纤维的情况下,钢纤维掺量较多试件的损伤发展快于掺量较少的试件,并且随着钢纤维掺量的增加,峰值荷载的损伤度越来越大;钢纤维用量越多,试件在峰值荷载状态下的耐损伤性能越好,即使在较严重的损伤状态下也依然能够保持极限承载能力。     

线性文化遗产的空间格局构建——以明长城大同段为例

线性文化遗产保护的重要性和迫切性已成为共识。以明长城大同段为研究案例,综合现有文化遗产分类方法进行遗产要素分类与识别,利用空间信息技术和不同遗产价值评价体系进行资源评价与分析,并总结多级别遗产点的地理空间分布规律。基于"核心保护与多级别缓冲"保护格局,结合实际问题和相关法规文件从宏观层面提出横向层级式、纵向组团式的空间格局,最后针对不同层次的遗产区域组合,制定实操性较强的保护策略。借此为中国线性文化遗产保护的空间格局规划理论与技术研究提供经验,以完善中国文化遗产保护体系。     

基于改进引力模型的成都城市圈引力格局划分研究

通过研究区域内各个城市之间的引力关系,能够探索城市之间的经济关系,这是合理划分城市圈内城市组团,实现城市组团协同发展的基础。基于城市竞争力和矢量的城市引力模型,通过加入心理距离相关理论对模型进行了改善,并以成都城市圈为例,阐述成都城市圈引力格局现状及经济联系。结果表明:通过改进后的城市引力模型计算的引力结果,反映出城市相对引力现状基本符合客观事实;成都城市圈明显呈现出“一家独大”的经济格局,成都市的城市竞争力和引力远远超出平均水平,整个城市的经济联系过于分散,区域内各城市发展不均衡,有待未来改善。