浆液法制备催化剂涂层自动吹扫设备及工艺

结构催化剂涂层常采用浆液法涂敷制备,但是,采用手工涂敷由于制备工艺差异大、可重复性差,导致制备过程中还存在涂层脱落、堵塞、涂层均匀性差、工业生产放大困难等问题。针对上述问题,文中设计搭建了一套自动化浆液吹扫装置,研究吹扫气流量、吹扫角度和气流移动速度等工艺参数对涂层负载量、脱落率和涂层一致性的影响。结果表明:研发的自动化吹扫设备及工艺有效提高了涂层涂敷过程的一致性和均匀性,气体流量逐渐增加,涂层的负载量与脱落率呈现下降的趋势。当气体流量为40 L/min,气流与丝网的夹角为90°,滑块的移动速度为600 mm/min时,制备得到的催化剂涂层的负载量为18.33%,脱落率(质量分数)低于2%,涂层表面平整光滑、无堵孔,综合指标优于文献现有报导水平,满足使用要求。开发的催化剂涂层自动化制备技术为丝网结构催化剂的工业化规模制备和应用提供了可行性。

Clinical study of impedance cardiography combined with passive leg raise test for non-invasive hemodynamic monitoring and treatment in patients with acute myocardial infarction complicated with heart failure

Background Active and effective treatment of acute myocardial infarction(AMI)with heart failure will significantly improve the patient’s prognosis and quality of life.The selection of clinical heart failure drugs is guided by the comprehensive judgment of central venous pressure,chest X-ray lung congestion degree,serum B-type natriuretic peptide(BNP)value,echocardiogram,blood pressure,etc.,which is currently the most commonly used method in clinical practice.However,the prolonged results of chest X-ray,serum BNP value and echocardiogram affect the real-time judgment of hemodynamics,which affect the accuracy of drug selection for patients with heart failure.The impedance cardiography(ICG)for hemodynamic monitoring technology can supply immediately hemodynamic results,which has been used less for the patients of AMI with heart failure at home and abroad.Therefore,this study was to evaluate the application value of ICG combined with the passive leg raise test(PLR)in AMI patients with heart failure.Methods 110 patients with AMI combined with killip grade 2 and above were randomly divided into a control group(n=55)and an ICG group(n=55).In the ICG group,heart failure treatment drugs were selected according to some parameters measured by ICG.In the control group,the treatment drugs for heart failure were selected according to routine symptoms,signs,BNP,etc.The associations of some ICG parameters of all patients with BNP,left ventricular ejection fraction(LVEF)values were analyzed.The value of BNP,LVEF value and the 6-minute walking distance(6 MWD)were determined between the two groups,on the 7th day after surgery.Results BNP value was negatively correlated with cardiac output(CO),cardiac output index(CI),stroke volume(SV),stroke output index(SI),left ventricular stroke work(LSW),left ventricular stroke work index(LSWI),left ventricular ejection time(LVET),ejection period contraction index(EPCI)(P<0.05)and positively correlated with stroke system vascular resistance(SSVR)/index(SSVRI),system volume resistance(SVR),pre-ejection period(PEP),shrink time ratio(STR)(P<0.05).Moreover,LVEF value was positively correlated with CO,CI,SV,SI,heart rate rhythm,LSW,LSWI,LVET,EPCI(P<0.05),and negatively correlated with SSVR,SSVRI,SVR,vascular elasticity,PEP,STR(P<0.05).On the 7 thpostoperative day,the BNP levels were decreased in the both two groups,and the BNP values were decreased more significantly in the ICG group compared to the control group(P<0.05).Moreover,the 6 MWD in the ICG group were significantly increased compared to the control group(P<0.05).Conclusions Some ICG parameters can reflect the early cardiac function of patients with AMI and heart failure after PCI treatment.By using ICG technology,the patient’s hemodynamics and cardiac function can be more accurately judged,and the drugs for heart failure can be further adjusted to promote the patient’s early recovery and improve the quality of life.