摘要：In this work, the synthesis of epichlorohydrin(ECH) from 1,3-dichloropropanol(DCP) by using solid sodium hydroxide(NaOH) is carefully investigated. Inert organic solvent, 1-octanol, is introduced to ensure reaction intensity under control. The reaction performances with respect to apparent kinetics and selectivity are determined to explore optimized reaction conditions and confirm potentials for enhancing productivity in one batch. The dissolution and liquid phase reaction mechanism and instant reaction assumption are proposed and verified through process analysis. A process design towards free additional water is schematically figured out to manipulate solid NaOH, by-product,and unreacted starting materials to realize a nearly closed circuit. This process allows high selectivity over 97% and complete DCP conversion at 323.2 K within a reaction time less than 20 min. Other advantages include near-zero wastewater emission, economically possible NaOH regeneration from NaCl, and robust operating condition window.

摘要：为调控聚集太阳光在容积式吸热芯内部的吸收分布,建立玻璃管束与多孔介质双层吸热芯光路传输模型与实验模型。在实验验证的基础上,采用加速蒙特卡洛法(MCM),模拟聚集太阳光在双层吸热芯内部的镜反射、各项异性散射和介质吸收过程,分析玻璃管束与多孔介质的结构参数等因素对聚集太阳光辐射传输性质的影响。结果表明,90%以上入射聚集太阳光能够穿透石英玻璃管束进入多孔介质吸热芯,太阳吸收热源项峰值位于吸热芯内部的多孔介质入口段,实现太阳吸收热源项分布梯度增加,且双层吸热芯的吸收比/发射比峰值达到3.05。

摘要：针对当前纵卧辊式玉米收获机作业存在籽粒啃伤严重和落粒损失大的问题,以激振理论为指导,以玉米果穗与茎秆分离为条件,建立了适于玉米机械化收获的玉米激振摘穗理论模型;以该激振摘穗模型为指导,构建并优化了适于玉米激振运动的摘穗辊外形结构和配置方式,开发了相应的激振摘穗试验台;采用Box-Behnken试验设计方法,研究了激振摘穗辊棱边数、振幅、摘穗辊转速对果穗摘穗过程籽粒破损率和落粒损失率的影响规律,建立了试验因素与考察指标之间的回归方程,并生成了相应的响应曲面。结果表明,激振摘穗装置中棱边数、振幅和摘穗辊转速对收获过程果穗籽粒破损率和落粒损失率有显著的影响。以非线性规划理论为指导,确定了最佳组合为摘穗辊转速950 r/min、棱边数8、振幅0. 75 cm,在该条件下进行了试验验证,得出平均籽粒破损率为0. 124%,平均落粒损失率为0. 228%,均低于国家玉米收获机械技术标准要求。

摘要：文章基于PLC设计了8层电梯控制系统,该系统以西门子s7-200PLC为控制核心,西门子编程软件V4.0 STEP 7 Micro进行I/O分配和电梯控制系统程序编写,利用组态王组态软件制作仿真测试模型模拟小区电梯运行。结果表明:所设计的8层电梯控制系统,能够实现电梯的延时开关门、平层泊车、实时楼层位置显示、上下行控制、超载检测以及防夹人、呼梯登记、顺向截梯等功能,控制效果良好。