不同“发汗”工艺处理茯苓及茯苓皮的UPLC指纹图谱研究

目的:对不同“发汗”方式处理的茯苓进行超高液相色谱法(UPLC)指纹图谱的比较研究,阐述不同“发汗”方式对茯苓、茯苓皮化学成分的影响,以期筛选出适合茯苓、茯苓皮的“发汗”方法。方法:对所采集的鲜茯苓进行不同“发汗”工艺处理,干燥后对其甲醇提取物进行UPLC分析,建立用以评价“发汗”方法优劣的指纹图谱体系。采用Agilent-ZORBAX SB-C_(18)色谱柱(250 mm×4.6 mm,5μm),以乙腈-0.2%乙酸水溶液为流动相梯度洗脱;流量为1.0 mL·min^(-1),柱温为30℃,检测波长分别为254、210 nm。结果:研究了茯苓“发汗”工艺,发现模拟“发汗”4 d的茯苓整体质量较优,并建立了评价茯苓、茯苓皮优劣的UPLC指纹图谱,茯苓、茯苓皮分别确定了21、23个共有峰;不同“发汗”时间中,茯苓中茯苓酸、猪苓酸C的含量存在总体先升高再降低最后趋于平稳的变化趋势,茯苓皮中的茯苓酸、猪苓酸C的含量存在先降低后升高再降低的变化趋势,茯苓皮中次生代谢产物含量显著高于茯苓。结论:建立的UPLC指纹图谱分析法可同时用于茯苓、茯苓皮有效成分的定性和定量测定,该方法重复性好、可操作性强,可较全面地反映新型模拟“发汗”与蒸制“发汗”工艺处理的茯苓、茯苓皮之间的差异,通过比较醇溶性浸出物、总三萜、茯苓酸、猪苓酸C的含量,证明模拟“发汗”茯苓品质优于蒸制“发汗”茯苓。

某多层框架隔震结构采用橡胶支座和摩擦摆支座的比较分析

《建设工程抗震管理条例》推行以来,设计人员广泛面临多层框架隔震结构设计方法不明确、不完善的问题,为了探究隔震计算中一些关键设计参数,本文以某8度(0.2g)区重点设防类的多层框架隔震结构为例,采用橡胶支座和摩擦摆支座两种方案,从设计方法和分析结果两方面比较了两种支座隔震结构的异同点。结果表明:摩擦摆支座的反应谱法还有待进一步的研究,橡胶支座的反应谱法较为完善;摩擦摆支座隔震结构和橡胶支座隔震结构的底部剪力比接近;摩擦摆支座水平滑动时产生竖向位移,该竖向位移引起的加速度基本可以忽略;摩擦摆支座传给支柱的弯矩要考虑球冠体的竖向位移;摩擦摆支座的连接螺栓只受剪,没有水平力产生的弯矩,而橡胶支座的连接螺栓承受剪力和水平力产生的弯矩。上述结论对于多层框架隔震结构的设计应用有一定的工程借鉴和理论参考价值。

Collaborative optimization of exhaust gas recirculation and Miller cycle of two-stage turbocharged marine diesel engines based on particle swarm optimization

To meet increasingly stringent emission standards and lower the brake-specific fuel consumption(BSFC)of marine engines,a collaborative optimization study of exhaust gas recirculation(EGR)and a Miller cycle coupled turbocharging system was carried out.In this study,a one-dimensional numerical model of the EGR,Miller cycle,and adjustable two-stage turbocharged engine based on WeiChai 6170 marine diesel engine was established.The particle swarm optimization algorithm was used to achieve multi-input and multi-objective comprehensive optimization,and the effects of EGR-coupled Miller regulation and high-pressure turbine bypass regulation on NO_(x)and BSFC were investigated.The results showed that a medium EGR rate-coupled medium Miller degree was better for the comprehensive optimization of NO_(x)and BSFC.At medium EGR rate and low turbine bypass rates,NO_(x)and BSFC were relatively balanced and acceptable.Finally,an optimal steady-state control strategy under full loads was proposed.With an increase in loads,the optimized turbine bypass rate and Miller degree gradually increased.Compared with the EGRonly system,the optimal system of EGR and Miller cycle coupled turbine bypass reduced NO_(x)by 0.87 g/(kW·h)and BSFC by 17.19 g/(kW·h)at 100%load.Therefore,the EGR and Miller cycle coupled adjustable two-stage turbocharging achieves NO_(x)and BSFC optimization under full loads.