混凝土框架结构负弯矩区围板型粘钢加固节点抗震空间效应研究

本文以某办公楼改造工程为实例,对框架结构负弯矩区围板型粘钢加固方法的空间效应进行研究。通过ANSYS有限元软件,采用模态分析、谱分析、时程分析对3组模型进行仿真计算,对3组模型的抗震空间效应结果进行对比分析,结果均显示围板型粘钢加固方法具有较好的抗震性能。本文结果对多层或高层结构某区域梁负弯矩加固后的局部效应具有指导意义。     

基于改进Faster R-CNN及YOLO的大角度车牌识别算法

随着大数据时代的到来,智慧城市等一系列概念的提出,人工智能开始在城市各个角落得到广泛应用。其中,车牌识别作为城市道路交通重要的一环,也取得了重大突破。基于深度学习的车牌识别一经提出,各类算法应用于车牌检测及识别上,对比于传统的车牌识别,大大提高了识别的速率和准确率。然而,在非限制条件下,如大角度车牌识别准确率仍有提升的空间。提出了一种改进的FasterR-CNN与YOLO的深度学习车牌识别算法,将对大角度下的车牌识别准确率达到了99.7%。由于是轻量型的框架,为后续的移动设备部署工作提供了便利。     

破浪板对FPSO大型LPG储罐晃动的抑制作用

为缓和浮式生产储卸油装置(Floating Production Storage and Offloading,FPSO)晃动时液化石油气(Liquefied Petroleum Gas,LPG)大型储罐内的液体介质对壳体的冲击影响,在LPG储罐内设置破浪板。采用计算流体力学(Computational Fluid Dynamics,CFD)软件分析破浪板对流体晃动的抑制作用并进行受力计算。利用流体体积(Volume of Fluid,VOF)气液两相模型建立六面体与四面体网格混合划分模型,通过CFD的动网格功能模拟船体晃动。结果表明,选取的数值计算模型与试验结果吻合较好。数值模拟结果表明设置破浪板能够有效降低晃动幅度,稳定气液界面,稳定压力分布和波动,减小罐体受液体冲击力,从而确保LPG储罐在FPSO上的使用安全。     

Ultrasonic Fabrication of Polymer Plate Reactors with a Surface Coating

Microreactors offer several advantages compared to the industrial scale when developing new chemical processes. Especially the production and investment costs are low if polymer microreactors are generated by ultrasonic processes. In order to observe the chemical reaction and the flow configuration, these microreactors need to be optically transparent, mechanically stable, and chemically inert to several reagents. The manufacturing process of a transparent polymer plate reactor with a chemically inert surface coating by ultrasonic fabrication is described. Experimental characterization of the microreactors showed that they are leak tight up to a pressure difference of at least 300 kPa and the mixing times are in the range of milliseconds.     

Hall current impacts on unsteady MHD free convective flow past an infinite vertical porous surface

In this paper, the magnetohydrodynamic free convective flow of an incompressible electrically conducting fluid over a vertical plate embedded in a porous medium is considered. A homogeneous transverse magnetic field is applied in the presence of a heat source and chemical reaction in a rotating frame, taking Hall current effects into account. The momentum equations for the fluid flow in a porous medium were determined by Brinkman modeling. At the undisturbed state, both the plate and fluid have an rigid body rotation due to the constant angular velocity, perpendicular to the infinite vertical plane surface. The vertical surface is subject to the homogeneous constant suction and the heat on the surface vary by time about a nonzero constant rate whereas the temperature of free stream is engaged to be constant. The accurate solutions for the velocity, temperature, and concentration distributions were acquired systematically using the perturbation method. The consequences of an assortment of governing flow parameters on the velocity, temperature, and concentration were analyzed through graphical profiles. The computational results for the skin friction, Nusselt number, and Sherwood number in a tabular format were also examined.     

3-D Elasticity Solutions of Layered Rectangular Plates Subjected to Thermo-Loads

According to the exact three-dimensional (3D) thermoelasticity theory, the elasticity solution of the simply-supported layered rectangular plates subjected to steady temperature loads was studied. An analytical method was developed to solve the temperature, stress and displacement fields in the plate. Firstly, the general solutions of the temperature, displacements and stresses in a simply-supported isotropic layer were obtained by solving the 3-D heat conduction equation and the 3-D equations of elasticity respectively, which were expressed in the form of double Fourier series. Then, the temperature, displacement and stress relationships between the upper surface and the lower surface of the isotropic layer were derived. Based on the continuity of the temperature, the heat flux, the displacements and the stresses on the interface of two adjacent layers with different material properties, the recursive formulae of temperature, displacements and stresses between the bottom layer and the top layer of the layered plate were obtained by using the transfer matrix method. The unknown coefficients in the solutions for every layer were uniquely determined by the upper surface and lower surface conditions of the plate. The distributions of the temperature, displacements and stresses in the plate were given by substituting the unknown coefficients obtained back to the recurrence formulae and the solutions. The convergence of the solutions was checked with respect to the number of the terms of series. Comparing the results with those obtained from the finite element method, the correctness of the present method was verified. Finally, the effects of surface temperatures, plate thickness, layer number and material properties of each layer on the distributions of the temperature, displacements and stresses in the plates were discussed in detail.     

110t钢包滑板及其机构的改进与优化

通过优化滑板材质、调整滑板体积、优化滑板形状、改进钢包滑动机构等措施对原滑板进行了改进,改进后的滑板连滑率达到了100%,使用寿命达到了4次,基本上满足了生产要求。     

加压灰熔聚气化炉工业运行分析

以天溪煤制油分公司灰熔聚气化炉的生产运行为例,分析了对入炉原料煤的指标要求,介绍了灰熔聚气化炉设备结构及流化床的物料循环机理,分析了灰熔聚气化炉在不同的分布板气速、中心管气速、氧气浓度条件下的运行状况。工业运行结果表明,首套加压灰熔聚气化炉生产运行稳定,且能满足相关地区就地取材的要求。     

降低矸石带煤率的方法

中国目前入选原煤中60%左右是跳汰洗选。在跳汰选煤过程中,影响跳汰机分选效率的因素有入料原煤特性,跳汰机风阀周期特性(跳汰频率及进、排气时间),矸石段、中煤段排料情况,各室顶水情况,风压、水压等,并且诸因素间相互制约,再加上人为因素的影响,既兼顾精煤质量又提高分选效率非常困难。以济三煤矿选煤厂BATAC跳汰机为例,通过改善风量与水量的配比,改造跳汰机筛板,稳定床层的同时,保证了精煤灰分,矸石带煤率由原先的6%降至5%以下,提高了精煤回收率,为选煤厂带来明显的经济效益。