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非金属有序大孔磷酸硼晶体合成及催化丙烷氧化脱氢反应性能 被引量:7
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作者 陆文多 高新芊 +4 位作者 王泉高 李文翠 赵侦超 王东琪 陆安慧 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第12期1837-1845,共9页
有序大孔材料具有大的比表面积和有序开放的立体孔道结构,有利于暴露更多的活性位点,促进传质扩散,从而提高催化活性.目前,已有报道的有序大孔材料包括金属及氧化物、氧化硅、炭、聚合物等.非金属含氧化合物具有耐氧化的结构特点,适合... 有序大孔材料具有大的比表面积和有序开放的立体孔道结构,有利于暴露更多的活性位点,促进传质扩散,从而提高催化活性.目前,已有报道的有序大孔材料包括金属及氧化物、氧化硅、炭、聚合物等.非金属含氧化合物具有耐氧化的结构特点,适合应用于高温氧化反应,但是体相非金属含氧化合物的比表面积低,并且孔道极不发达,因此亟需合成有利于传质的有序大孔非金属含氧化合物晶体材料.最近研究者发现,硼基催化剂在催化低碳烷烃氧化脱氢制烯烃反应中呈现出高的反应活性、选择性和稳定性,且我们发现B-O(B-OH)位点在硼基催化材料中起着至关重要的作用.三元非金属磷酸硼晶体由BO4和PO4四面体组成,具有优异的热稳定性和抗氧化性能,有可能适合于催化丙烷氧化脱氢制丙烯的反应.但制备磷酸硼晶体过程通常需要经过高温焙烧,从而导致产物结构密实、无孔、外表面积低.此外,丙烷氧化脱氢反应具有强放热特性,易在催化剂表面形成热点,引起烯烃产物的二次反应,降低目标产物选择性,因此解决传质传热问题尤为重要.如果能充分利用磷酸硼的高导热性,同时调控孔结构以改善传质,减少接触时间,则有望设计一种具有良好催化选择性和产率的非金属催化剂,助力丙烷氧化脱氢制丙烯研究领域的发展.本文设计合成了结构稳定的三维有序大孔磷酸硼晶体材料,在丙烷氧化脱氢反应中表现出优异的催化活性及选择性.在515℃反应丙烷转化率达14.3%,丙烯选择性达82.5%,烯烃选择性达91.5%,同时,深度氧化的产物CO2选择性不超过1%.由于有序大孔的结构改善了传质,并暴露出更多的活性位点,该催化剂可在高空速下展现出较高的烯烃产率(~16 golefin gcat^-1 h^-1),是目前报道的大部分丙烷氧化脱氢催化剂所能得到的烯烃产率的2-100倍.本文采用电镜、X射线衍射、红外、固体核磁及X射线光电子能谱等手段探究了有序大孔磷酸硼催化剂在丙烷氧化脱氢反应中的结构稳定性及活性位点.结果表明,有序大孔磷酸硼骨架在反应过程中稳定性好,反应后作为活性位的磷酸硼催化剂表面的三配位硼物种有所增加.本文为制备结构稳定、抗氧化性强且催化活性优异的新型非金属催化剂提供了新的途径,为促进氧化脱氢制烯烃研究领域的发展提供了材料支撑平台. 展开更多
关键词 有序大孔材料 非金属催化剂 磷酸硼 氧化脱氢 丙烷
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MODIFIED CLASSIC RISK FACTORS FOR CORONARY ARTERY DISEASE IN CHINESE HAN POPULATION 被引量:2
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作者 Han-bin Cui Sheng-huang wang +7 位作者 dong-qi wang Chang-cong Cui Xin-yi Chen Xiao-min Chen Zheng Zhang Hong-kao Zhang Feng Bai Joseph B Muhlestein 《Chinese Medical Sciences Journal》 CAS CSCD 2007年第4期216-223,共8页
Objective To investigate the levels of cardiovascular disease risk factors and their relations to clinical phenotype associated with coronary artery disease(CAD).Methods The subjects were recruited from five independe... Objective To investigate the levels of cardiovascular disease risk factors and their relations to clinical phenotype associated with coronary artery disease(CAD).Methods The subjects were recruited from five independent cardiovascular centers.Coronary angiography was employed to define the CAD with stenosis in each major vessel ≥70% and control with stenosis <10% in every lesion.The classic risk factors including family history,body mass index,smoking habits,hypertension,diabetes mellitus,and serum lipid levels were surveyed according to established criteria.Associations between risk levels and clinical phenotypes were assessed by case control and correlation analysis.Results A total of 762 individuals were collected,including 481 men and 281 women,aged from 17 to 81(mean 60±10) years.The patients with CAD accounted for 55.5% of all participants,and controls 44.5%,respectively.Compared with the pattern in published data,our study showed that mean serum high density lipoprotein cholesterol(HDL-C) level was significantly lower(P<0.001) and triglycerides was significantly higher(P<0.001),while total cholesterol(TC) and low density lipoprotein cholesterol levels were comparative(both P>0.05).The prevalence of low HDL-C(<40 g/L) and hypertriglyceridemia(>150 g/L) were 27.2% and 41.4%,respectively.Mean serum levels of HDL-C and apolipoprotein A1 were significantly higher in female subjects than in male(P<0.001).Lower HDL-C functioned as an independent risk factor for CAD only in men(RR=2.8,95%CI:1.5-4.2,P<0.001),yet increased non-HDL cholesterol combined with diabetes mellitus and obesity seemed to play a key role in the development ofCAD in women.Similarity in risk association with CAD was found for hypertension and TC/HDL ratio in male and female subjects,while family history had no relationship with the presence of CAD.Conclusion It is remarkable that emphasis of intervention in future should be given on the prevalent low serum HDL-C and its strong risk correlation with the presence of CAD in male subjects of Chinese Han population. 展开更多
关键词 中国人 汉族 冠心病 高密度脂蛋白胆固醇 风险因子
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Prediction and programming of microemulsion phase behavior simulation
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作者 dong-qi wang Dai-Yin Yin +2 位作者 Jun-Da wang Ya-Zhou Zhou Cheng-Li Zhang 《Petroleum Science》 SCIE CAS CSCD 2022年第3期1401-1410,共10页
In the process of microemulsion flooding,microemulsion phase state may be affected by the adsorption of core and the distribution of oil and water,and the upper phase,the middle phase or the lower phase microemulsion ... In the process of microemulsion flooding,microemulsion phase state may be affected by the adsorption of core and the distribution of oil and water,and the upper phase,the middle phase or the lower phase microemulsion will appear.Accurate description of microemulsion phase state and quantitative discrimination of equilibrium phase composition are of great theoretical value and research significance for the design of microemulsion flooding system and improving the recovery efficiency of microemulsion.Therefore,in this paper,microemulsion phase model is deeply studied.Aiming at the difficulty of solving the existing Hand model and the unknown parameters of the improved HLD-NAC model,we introduce the binodal curve range parameter D and the asymmetric migration degree parameter B,and establish a new phase behavior description method of the binodal curve,the two-phase plait point lines and the III-phase node line.Then the phase discrimination programming of microemulsion was carried out,and the change laws of phase number,phase type and mass fraction of equilibrium phases of any microemulsion system under different salinity were revealed.The results show that the simulation results of microemulsions accord with the salinity scanning law,and can accurately identify the complex microemulsion phase states. 展开更多
关键词 MICROEMULSION Phase model Conditions for phase discrimination PROGRAMMING Salinity scanning
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Evaluation of Safety and Efficacy of Qinming8631 DR Implantable Cardiac Pacemaker in Chinese Patients: A Prospective, Multicenter, Randomized Controlled Trial of the First Domestically Developed Pacemaker of China 被引量:2
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作者 Mei-Xiang Xiang dong-qi wang +12 位作者 Jing Xu Zheng Zhang Jian-Xin Hu Dong-Mei wang Xiang Gu He-Ping Liu Tao Guo Xiang-Jun Yang Feng Ling Jia-Feng Lin Shang-Lang Cai Guo-Bin Zhu Jian-An wang 《Chinese Medical Journal》 SCIE CAS CSCD 2016年第22期2659-2665,共7页
Background:High cost of imported pacemakers is a main obstacle for Chinese patients suffering from bradyarrhythmia,and a domestically developed pacemaker will help lower the burden.This study aimed to evaluate the sa... Background:High cost of imported pacemakers is a main obstacle for Chinese patients suffering from bradyarrhythmia,and a domestically developed pacemaker will help lower the burden.This study aimed to evaluate the safety and efficacy ofQinming8631 DR (Qinming Medical,Baoji,China),the first domestically developed dual-chamber pacemaker of China,compared with a commercially available pacemaker Talos DR (Biotronik,Berlin,Germany) in Chinese patients.Methods:A prospective randomized trial was conducted at 14 centers in China.Participants were randomized into trial (Qinming8631 DR) and control (Talos DR) groups.Parameters of the pacing systems were collected immediately after device implantation and during follow-ups.The effective pacing rate at 6-month follow-up was recorded as the primary end point.Electrical properties,magnet response,single-and double-pole polarity conversion,rate response function,and adverse events of the pacing system were analyzed.The Cochran-Mantel-Haenszel Chi-square test,paired t-test,and Wilcoxon signed-rank test were used for measuring primary qualitative outcomes and comparing normally and abnormally distributed measurement data.Results:A total of 225 patients with a diagnosis ofbradyarrhythmia and eligible for this study were randomly enrolled into the trial (n =113) and control (n =112) groups.They underwent successful pacemaker implantation with acceptable postoperative pacing threshold and sensitivity.Effective pacing rates of trial and control groups were comparable both in the full analysis set and the per protocol set (81.4% vs.79.5%,P =0.712 and 95.4% vs.89.5%,P =0.143,respectively).In both data sets,noninferiority of the trial group was above the predefined noninferiority limit(-9.5%).Conclusions:This study established the noninferiority ofQinming8631 DR to Talos DR.The safety and efficacy ofQinming8631 DR pacemaker were comparable to those of Talos DR in treating patients with cardiac bradyarrhythmia. 展开更多
关键词 BRADYARRHYTHMIA Cardiac Pacemaker Qinming8631 Safety and Efficacy
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