大豆油制取加工过程中废气异味治理工艺技术实践应用

在大豆油制取和加工过程中会散发出废气异味,对环境造成一定的污染。为此,设计开发了一套适合大豆油制取和加工工艺的废气异味治理工艺系统,并已应用实践,效果良好。全套工艺设备设计选型包括湿式净化塔、脱水除雾装置、循环捕集泵、复合光催化装置、异味控制系统(除臭母片)、调频离心引风机、循环水箱(New Bio-C生物脱臭液)等。     

大型海工绕桩吊机吊臂激光冲击强化选材研究

吊臂是大型海工绕桩吊机的主要承重部件之一,吊臂材料的表面强化和优选研究对绕桩吊机的高质量、高强度制造起着重要作用。选取Q235、Q345、Q550三种钢材作为吊臂制造的研究材料,采用激光冲击强化技术进行表面处理,对比冲击前后材料的表面残余应力、表面粗糙度、显微硬度和抗拉强度。结果表明:三种钢材经激光冲击强化后,残余应力分别提高500%、346.7%、192.9%,表面粗糙度值分别提高15.5%、3.5%、13.3%,显微硬度分别提高15.9%、17.3%、13.2%,抗拉强度分别提高6.1%、7.5%、5.0%。通过综合考虑三种钢材的性能指标数据及吊臂的实际应用场景,选择Q345钢作为吊臂制造材料的加工效果最优。     

Amphiphilic starch with 3-(trimethylammonium chloride)-2-hydroxypropyl and octenylsuccinyl substituents for strong adhesion to fibers

Amphiphilic starch derivatives with oleophilic octenylsuccinyl (OS) and hydrophilic 3-(trimethylammonium chloride)-2-hydroxypropyl (TMACHP) substituents were derived by the quaternization of acid-treated maize starch with N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride followed by the octenylsuccinylation with octenylsuccinic anhydride. Two series of amphiphilic starches with differential degrees of substitution (DS) and mole percentages of OS to the total substituents introduced onto the starch were characterized by elemental analysis, chemical titration, and FTIR spectroscopy. The effects of the DS and mole percentage on the adhesion of the starch to fibers were investigated using a legal method (FZ/T 15001-2008). The modification was able to significantly improve the adhesion of starch to cotton and polyester fibers due to the reduced surface tension of the cooked starch paste. The adhesion depended not only on the DS of OS and TMACHP substituents, but also on the mole percentage of the OS. The amphiphilic starch had superior adhesion to acid-treated and TMACHP-functionalized starches. The adhesion of the amphiphilic starch was found to reach its maximum at a mole percentage of 70.6% OS. An increase in the total DS reduced the surface tension and favored adhesion, but disfavored reaction efficiency. Based on the adhesion and reaction efficiencies, the amphiphilic starch with a total DS in the range of 0.029–0.051 and a mole percentage of 70.6% OS showed potential for use in warp sizing.     

浇注式导电沥青混凝土传导热效果

为实现浇注式沥青混凝土钢桥面铺装融雪化冰的目的,制备了浇注式导电沥青混凝土,提出了其传导热效果的测试方法,全面研究了电极布设方式、碳纤维撒布量、导电相材料掺量对浇注式导电沥青混凝土传导热效果的影响规律,对比评价了不同类型浇注式导电沥青混凝土单层板传导热效果,并回归拟合了浇注式导电沥青混凝土温度随通电时间变化的曲线。结果表明:浇注式导电沥青混凝土电极材料宜采用铝电极,电压输出方式为交流电源,输出大小宜为54 V;浇注式导电沥青混凝土最佳电极布设方式为竖向、碳纤维撒布量为170 g/m²、导电相材料掺量为0.8%;五种浇注式导电沥青混凝土中,竖向置入铜丝网混凝土传导热效果最优,铺设碳纤维带混凝土次之;在同一环境温度条件下,各类型混凝土中部的温度变化趋势与面层温度相同,基本呈线性变化。从而为浇注式导电沥青混凝土的工程应用奠定基础。     

双定子涡流制动器电磁参数对制动力矩的影响

介绍了双定子涡流制动器(DSECB)的工作原理。根据等效磁路法推导了DSECB制动力矩公式。利用有限元法对DSECB进行了3D仿真分析。详细分析了DSECB各电磁参数对制动力矩特性曲线的影响,为DSECB优化设计提供了参考依据。     

基于FPGA的SSL VPN加速器的设计与实现

SSL VPN是一种新兴的安全远程接入的实现方式,SSL VPN采用SSL协议实现身份认证以及加密通道的建立等网络安全机制,目前正广泛地被企事业单位采用.SSL协议是互联网广泛使用的安全协议,身份认证主要是依靠非对称算法,而加密通道采用的是对称算法.采用复旦大学自主研发的FPGA产品FDK250-Ⅱ实现SSL VPN加速器.一般来说,SSL协议主要采用DES和3DES等对程算法,因此加速器的实现主要是对称算法的加速.数据表明,加密过程的性能是不加密过程性能的50%,而通过采用FDK250,实现了TCP协议超过30%性能的提高.     

对称转子辅助槽对内置式永磁同步电机齿槽转矩的影响

为减小内置式双层永磁体结构永磁同步电机齿槽转矩,研究了关于转子开辅助槽的方法.首先从理论上分析了齿槽转矩的产生机理,指出了转子开辅助槽降低齿槽转矩的可行性.然后运用有限元分析的方法,建立了8极48槽内置式V一型永磁同步电机仿真模型,并在转子表面关于永磁体中心线开设对称半圆形辅助槽,分析了辅助槽位置、半径,及单变量参数化...     

纯电动城市客车EMB执行机构驱动电机制动性能分析

传统气压制动系统存在压缩机、制动油箱和空气管路,占据较大空间,而采用电子机械制动(EMB)系统代替,不但可以减小空间,还能实现对夹紧力的快速响应和精确控制。以纯电动城市客车为目标车型,讨论了EMB执行机构方案,根据传统气压盘式制动器最大夹紧力推导出电机的堵转转矩和空载转速。据此设计了永磁无刷直流驱动电机,堵转转矩为10 N·m,空载转速为370 r/min。在Maxwell 2D中搭建驱动电机有限元模型,分析电机在消除间隙阶段和夹紧力增加阶段的制动性能。结果表明所设计的驱动电机制动性能可满足要求。     

钒基储氢合金的研究进展

钒基固溶体储氢合金具有高的储氢密度,并且室温下可以吸放氢,具有良好的动力学性能,因此被认为是最有潜力的车载储氢材料之一.介绍了金属钒吸放氢特性,概述了钒基储氢合金的研究进展,就近年来改善钒基储氢合金性能的方法进行了总结,并对钒基储氢合金的稳定性及应用成本等问题进行了探讨.最后,对铳基储氢合金亟待解决的问题及发展方向进行了展望.     

Ultrafine tuning of the pore size in zeolite A for efficient propyne removal from propylene

The removal of trace propyne (C3H4) from propyne/propylene (C3H4/C3H6) mixtures is a technical and challenging task during the production of polymer-grade propylene in view of their very similar size and physical properties.While some progress has been made,it is still very challenging to use some highly stable and commercially available porous materials via an energy-efficient adsorptive separation process.Herein,we report the ultrafine tuning of the pore apertures in type-A zeolites for the highly effi-cient removal of trace amounts of C3H4 from C3H4/C3H6 mixtures.The resulting ion-exchanged zeolite 5A exhibits a large C3H4 adsorption capacity (2.3 mmol g-1 under 10-4 MPa) and high C3H4/C3H6 selectivity at room temperature,which were mainly attributed to the ultrafine-tuned pore size that selectively blocks C3H6 molecules,while maintaining the strong adsorption of C3H4 at low pressure region.High pur-ity of C3H6 (＞99.9999％) can be directly obtained on this material under ambient conditions,as demon-strated by the experimental breakthrough curves obtained for both 1/99 and 0.1/99.9 (V/V) C3H4/C3H6 mixtures.