摘要：采用超临界流体萃取技术萃取花椒油脂,通过单因素试验和正交试验设计,研究花椒粉粒度、萃取压力、萃取时间和萃取温度等因素对花椒油脂的萃取率的影响,找到最佳的工艺条件。研究结果表明最佳工艺参数为花椒粉粒度60目、萃取压力15 MPa、萃取时间1.5 h、萃取温度45℃、CO2流量5 L/h^10 L/h。在此条件下,花椒油脂的萃取率可达12.27%以上。影响提取率的主次因素为萃取温度>萃取压力>萃取时间。

摘要：Obtaining a detailed understanding of the surface modification of supports is crucial;however,it is a challenging task for the development and large-scale fabrication of supported electrocatalysts that can be used as alternatives to Pt-based catalysts for the oxygen reduction reaction(ORR).In this study,commercial silicon carbide(SiC)was modified through surface oxidization(O-SiC)to support the use of Pd nanoparticles(Pd NPs)as electrocatalysts for *** obtained Pd/O-SiC catalysts exhibited better ORR activity,stronger durability,and higher resistance to methanol poisoning than that exhibited by commercial Pt/*** role of the support in enhancing the ORR performance,especially the oxidization of SiC surfaces,was discussed in detail based on the experimental characterizations and density functional theory *** underlying mechanism of the superior ORR performance of Pd/O-SiC catalysts was attributed to the charge transfer from SiC_(x)O_(y)to Pd NPs on the surfaces of SiC and the strong metal–support interactions(SMSIs)between Pd and SiC_(x)O_(y).The charge transfer enhanced the ORR activity by inducing electron-rich Pd,increased the adsorption of the key intermediate OOH,and decreased the Gibbs free energy of the critical ORR ***,SMSIs enhanced the ORR stability of the Pd/O-SiC *** study provided a facile route for designing and developing highly active Pd-based ORR electrocatalysts.

摘要：以大豆为原料,采用超临界CO2萃取法,针对影响超临界CO2萃取大豆油的主要因素(温度、压力、萃取时间、颗粒度)进行了研究,并对实验条件进行优化设计。通过单因实验和正交实验,得到超临界萃取工艺的最优条件:温度45℃、压力25MPa、颗粒度50目、萃取时间60min。大豆中油的萃取率可高达21.48%;各因素影响大豆油萃取率的主次顺序为:颗粒度>压力>萃取时间>温度。

摘要：【目的】为研究原位测量装置的测量特性和不同环境下海底沉积物声学特性的变化机制,设计一种海底原位分层声学测量模拟装置。【方法】装置主要由分层运动控制单元、声学测量单元和计算机控制单元三部分组成,通过电动缸对声学测量探杆进行定位运动与连续运动控制,实现对声学测量探杆运动精度分析。通过在水中进行测量标定,获得装置声学测量探杆的校正距离差和扩散衰减系数。通过模拟原位分层声学测量实验,实现不同类型海底沉积物的声学特性测量。【结果与结论】声学测量探杆的校正距离差为77.14 mm,此装置发射声波的平均扩散衰减系数为(34.30±0.46)dB/m。声学测量探杆运动控制精度高,能准确运动到不同层中进行声学特性分层测量,定位测量和连续测量两种测量方式都能获得稳定的实验数据。

摘要：集中供暖系统是当前北方供暖系统中采用的主要供暖方式。随着当前社会发展中,人们对供热要求也不断的提高,使得在供热过程中能够,各种供热方式和供热手段不断的更新和变化。集中供热作为一种高效、节能、环保的采暖方式,逐步成为当前取暖的主要手段,是当前供暖中的主要方式。然而集中供热采暖系统的故障是多种多样的,是复杂多变的故障形式。本文结合当前集中供热采暖中容易出现的各种问题进行分析,提出其相应的故障处理措施。