The cutting performance of particulate reinforced me tallic matrix composites(PRMMCs) SiC p/Al in ultrasonic vibration cutting and c ommon cutting with carbide tools and PCD tools was researched in the paper. Mic rost...The cutting performance of particulate reinforced me tallic matrix composites(PRMMCs) SiC p/Al in ultrasonic vibration cutting and c ommon cutting with carbide tools and PCD tools was researched in the paper. Mic rostructure of machined surface was described, the relation between cutting para meters and surface roughness was presented, and characteristic of the surface re mained stress was also presented. Furthermore, wear regularity and abrasion resi stance ability of tools in ultrasonic vibration cutting and common cutting o f PRMMCs were discussed in detail. The test results show: (1) The surface config urations are obviously different when using different tools to machine such PRMM Cs. The surface machined with carbide tools looks luminous and orderly and there are seldom surface defects on it. The reason is that the soft basal body is apt to flow during cutting, therefore a layer of Al matrix film covers machined sur face. On the contrary, the surface machined with PCD tools looks lackluster. But the profile of machined surface is very clear. Superfine grooves, pits and blac k reinforce particulates can be seen easily without obvious Al film. (2) Because of unstable cutting process in common cutting, the surface is easy to produce s ome defects such as burrs, built-up edges and so on so that the quality of surf ace becomes very poor. Vibration cutting can reduce the influence of tearing, pl astic deformation and built-up edge in cutting and can restrain flutter so as t o make cutting process more stable. Therefore, surface roughness of vibration cu tting is better than that of common cutting. (3) There is an optimum value of fe ed rate in vibration cutting of PRMMCs due to the influence of material characte ristics. Whether feed rate is more than or less than this optimum value, surface roughness will increase. (4) According to analyzing the wear rate of tools in v ibration cutting PRMMCs, it can be concluded that abrasion resistance of tools w ill be improved remarkably when vibration cutting composites have a lower pe rcentage of reinforce particulate. If the percentage of reinforce particulate is higher, the influence on abrasion resistance of carbide tool in vibration cut ting will not be obvious. The research result indicates that vibration cutting effect has a close relation with material characteristics.展开更多
随着能源互联网战略的深入实施,可再生能源与微电网的参与度不断攀升,系统中不确定性因素显著增加,各参与主体间的合作与竞争关系变得愈发错综复杂。从垂直和水平两个层面建立了电网、服务商及多微电网混合博弈双层电能交易体系。在垂...随着能源互联网战略的深入实施,可再生能源与微电网的参与度不断攀升,系统中不确定性因素显著增加,各参与主体间的合作与竞争关系变得愈发错综复杂。从垂直和水平两个层面建立了电网、服务商及多微电网混合博弈双层电能交易体系。在垂直层面提出主从博弈的思想,以服务商为主导者、微电网为从属者。构建不确定性问题分阶段优化的分段鲁棒优化模型,实现不确定性的差异化调度,提高鲁棒优化的灵活性。利用布尔-列和约束生成(Bool-Column and constraint generation,B-C&CG)算法求解模型,并把整个模型分为主问题和子问题:主问题优化电价不确定性问题,子问题优化源荷不确定问题。在水平层面搭建纳什谈判模型,通过交替方向乘子(alternating direction method of multipliers,ADMM)算法求解水平层面微电网之间的电能交互模型。利用分布式求解方法得出交易价格策略,再结合拉格朗日乘子法,交替优化各分部并更新乘子,得出各微电网之间的最佳交易电价。仿真结果表明,所提方案兼顾了系统的鲁棒性、经济性及灵活性,缩减了各微电网的成本并充分保护了各微网的隐私。展开更多
目的:探究微小RNA(miR)-574-3p、序列相似家族3成员C(family with sequence similarity 3 member C,FAM3C)在食管癌组织中的表达,并分析二者与患者临床病理特征的关系。方法:选取2018年5月至2020年5月于本院行手术治疗的90例食管癌患者...目的:探究微小RNA(miR)-574-3p、序列相似家族3成员C(family with sequence similarity 3 member C,FAM3C)在食管癌组织中的表达,并分析二者与患者临床病理特征的关系。方法:选取2018年5月至2020年5月于本院行手术治疗的90例食管癌患者,收集术中留取的癌组织和癌旁组织标本。使用qRT-PCR法检测组织中miR-574-3p、FAM3C mRNA相对表达量;使用免疫组织化学法检测组织中FAM3C蛋白表达情况;采用Spearman等级相关分析食管癌组织中miR-574-3p、FAM3C的相关性;Kaplan-Meier法分析miR-574-3p、FAM3C与预后的关系。结果:食管癌患者癌组织中miR-574-3p低表达,FAM3C mRNA、FAM3C蛋白高表达(P<0.05)。食管癌组织中miR-574-3p、FAM3C蛋白表达水平具有负相关性(r=-0.420,P<0.05)。Pearson相关性分析显示,食管癌组织中miR-574-3p、FAM3C mRNA表达具有负相关性(r=-0.731,P<0.05)。miR-574-3p、FAM3C蛋白均与TNM分期、浸润程度、淋巴结转移有关(P<0.05)。miR-574-3p高表达组3年累积生存率为83.72%,显著高于miR-574-3p低表达组(53.19%);FAM3C高表达组3年累积生存率为56.86%,显著低于FAM3C低表达组(82.05%),差异均有统计学意义(log rankχ^(2)=10.175、7.290,P<0.05)。结论:食管癌组织中miR-574-3p表达水平较低,FAM3C表达水平较高,且二者具有负相关性,与临床病理特征中的TNM分期、浸润程度、淋巴结转移以及患者3年累积生存率有关。展开更多
目的:基于网状Meta分析对治疗高血压肾病(hypertensive nephropathy,HTN)的不同种类口服中成药的有效性及安全性进行评价。方法:计算机检索中国知网(CNKI)、万方(Wanfang)、维普(VIP)、中国生物医学文献服务系统(SinoMed)、PubMed、EMb...目的:基于网状Meta分析对治疗高血压肾病(hypertensive nephropathy,HTN)的不同种类口服中成药的有效性及安全性进行评价。方法:计算机检索中国知网(CNKI)、万方(Wanfang)、维普(VIP)、中国生物医学文献服务系统(SinoMed)、PubMed、EMbase、Cochrane Library、Web of Science数据库,搜索建库至2024年3月20日所发表的治疗HTN中成药的随机对照试验(randomized controlled trials,RCT),采用RoB2、Stata 18.0软件进行数据统计分析。结果:最终纳入60篇RCTs,涉及11种中成药,总样本量5 576例。网状Meta分析结果显示:(1)在降低24 h尿蛋白定量(24 h UTP)方面,累计概率排名曲线下面积(SUCRA)排名前3的干预措施为金水宝胶囊/片+西医常规、松龄血脉康胶囊+西医常规、黄葵胶囊+西医常规;(2)在降低尿微量白蛋白(mALB)方面,SUCRA排名前3的干预措施为黄葵胶囊+西医常规、六味地黄丸+西医常规、通心络胶囊+西医常规;(3)在辅助降低收缩压(SBP)方面,SUCRA排名前3的干预措施为六味地黄丸+西医常规、百令胶囊+西医常规、黄芪片/颗粒+西医常规;(4)在辅助降低舒张压(DBP)方面,SUCRA排名前3的干预措施为黄芪片/颗粒+西医常规、六味地黄丸+西医常规、松龄血脉康胶囊+西医常规;(5)在降低血肌酐(Scr)方面,SUCRA排名前3的干预措施为复方丹参滴丸+西医常规、冠心丹参滴丸+西医常规、六味地黄丸+西医常规;(6)在降低尿素氮(BUN)方面,SUCRA排名前3的干预措施为复方丹参滴丸+西医常规、冠心丹参滴丸+西医常规、六味地黄丸+西医常规;(7)在降低胱抑素-C(Cys-C)方面,SUCRA排名前3的干预措施为黄葵胶囊+西医常规、冠心丹参滴丸+西医常规、百令胶囊+西医常规;(8)在提高内生肌酐清除率(Ccr)方面,SUCRA排名前3的干预措施为复方丹参滴丸+西医常规、冠心丹参滴丸+西医常规、金水宝胶囊/片+西医常规;(9)中成药的加用与不良反应的发生情况并无显著相关性。结论:在常规西医治疗的基础上,加用中成药治疗HTN有效且各有优势,能有效降低24 h UTP、mALB、Scr、BUN、Cys-C,辅助降低SBP、DBP,提高Ccr。但鉴于研究存在一定的局限性,上述结果尚需开展更多高质量临床RCTs予以验证。展开更多
文摘The cutting performance of particulate reinforced me tallic matrix composites(PRMMCs) SiC p/Al in ultrasonic vibration cutting and c ommon cutting with carbide tools and PCD tools was researched in the paper. Mic rostructure of machined surface was described, the relation between cutting para meters and surface roughness was presented, and characteristic of the surface re mained stress was also presented. Furthermore, wear regularity and abrasion resi stance ability of tools in ultrasonic vibration cutting and common cutting o f PRMMCs were discussed in detail. The test results show: (1) The surface config urations are obviously different when using different tools to machine such PRMM Cs. The surface machined with carbide tools looks luminous and orderly and there are seldom surface defects on it. The reason is that the soft basal body is apt to flow during cutting, therefore a layer of Al matrix film covers machined sur face. On the contrary, the surface machined with PCD tools looks lackluster. But the profile of machined surface is very clear. Superfine grooves, pits and blac k reinforce particulates can be seen easily without obvious Al film. (2) Because of unstable cutting process in common cutting, the surface is easy to produce s ome defects such as burrs, built-up edges and so on so that the quality of surf ace becomes very poor. Vibration cutting can reduce the influence of tearing, pl astic deformation and built-up edge in cutting and can restrain flutter so as t o make cutting process more stable. Therefore, surface roughness of vibration cu tting is better than that of common cutting. (3) There is an optimum value of fe ed rate in vibration cutting of PRMMCs due to the influence of material characte ristics. Whether feed rate is more than or less than this optimum value, surface roughness will increase. (4) According to analyzing the wear rate of tools in v ibration cutting PRMMCs, it can be concluded that abrasion resistance of tools w ill be improved remarkably when vibration cutting composites have a lower pe rcentage of reinforce particulate. If the percentage of reinforce particulate is higher, the influence on abrasion resistance of carbide tool in vibration cut ting will not be obvious. The research result indicates that vibration cutting effect has a close relation with material characteristics.
文摘随着能源互联网战略的深入实施,可再生能源与微电网的参与度不断攀升,系统中不确定性因素显著增加,各参与主体间的合作与竞争关系变得愈发错综复杂。从垂直和水平两个层面建立了电网、服务商及多微电网混合博弈双层电能交易体系。在垂直层面提出主从博弈的思想,以服务商为主导者、微电网为从属者。构建不确定性问题分阶段优化的分段鲁棒优化模型,实现不确定性的差异化调度,提高鲁棒优化的灵活性。利用布尔-列和约束生成(Bool-Column and constraint generation,B-C&CG)算法求解模型,并把整个模型分为主问题和子问题:主问题优化电价不确定性问题,子问题优化源荷不确定问题。在水平层面搭建纳什谈判模型,通过交替方向乘子(alternating direction method of multipliers,ADMM)算法求解水平层面微电网之间的电能交互模型。利用分布式求解方法得出交易价格策略,再结合拉格朗日乘子法,交替优化各分部并更新乘子,得出各微电网之间的最佳交易电价。仿真结果表明,所提方案兼顾了系统的鲁棒性、经济性及灵活性,缩减了各微电网的成本并充分保护了各微网的隐私。
文摘目的:基于网状Meta分析对治疗高血压肾病(hypertensive nephropathy,HTN)的不同种类口服中成药的有效性及安全性进行评价。方法:计算机检索中国知网(CNKI)、万方(Wanfang)、维普(VIP)、中国生物医学文献服务系统(SinoMed)、PubMed、EMbase、Cochrane Library、Web of Science数据库,搜索建库至2024年3月20日所发表的治疗HTN中成药的随机对照试验(randomized controlled trials,RCT),采用RoB2、Stata 18.0软件进行数据统计分析。结果:最终纳入60篇RCTs,涉及11种中成药,总样本量5 576例。网状Meta分析结果显示:(1)在降低24 h尿蛋白定量(24 h UTP)方面,累计概率排名曲线下面积(SUCRA)排名前3的干预措施为金水宝胶囊/片+西医常规、松龄血脉康胶囊+西医常规、黄葵胶囊+西医常规;(2)在降低尿微量白蛋白(mALB)方面,SUCRA排名前3的干预措施为黄葵胶囊+西医常规、六味地黄丸+西医常规、通心络胶囊+西医常规;(3)在辅助降低收缩压(SBP)方面,SUCRA排名前3的干预措施为六味地黄丸+西医常规、百令胶囊+西医常规、黄芪片/颗粒+西医常规;(4)在辅助降低舒张压(DBP)方面,SUCRA排名前3的干预措施为黄芪片/颗粒+西医常规、六味地黄丸+西医常规、松龄血脉康胶囊+西医常规;(5)在降低血肌酐(Scr)方面,SUCRA排名前3的干预措施为复方丹参滴丸+西医常规、冠心丹参滴丸+西医常规、六味地黄丸+西医常规;(6)在降低尿素氮(BUN)方面,SUCRA排名前3的干预措施为复方丹参滴丸+西医常规、冠心丹参滴丸+西医常规、六味地黄丸+西医常规;(7)在降低胱抑素-C(Cys-C)方面,SUCRA排名前3的干预措施为黄葵胶囊+西医常规、冠心丹参滴丸+西医常规、百令胶囊+西医常规;(8)在提高内生肌酐清除率(Ccr)方面,SUCRA排名前3的干预措施为复方丹参滴丸+西医常规、冠心丹参滴丸+西医常规、金水宝胶囊/片+西医常规;(9)中成药的加用与不良反应的发生情况并无显著相关性。结论:在常规西医治疗的基础上,加用中成药治疗HTN有效且各有优势,能有效降低24 h UTP、mALB、Scr、BUN、Cys-C,辅助降低SBP、DBP,提高Ccr。但鉴于研究存在一定的局限性,上述结果尚需开展更多高质量临床RCTs予以验证。
