调研了美国Class Central网站发布的“2023年250门全球最受欢迎在线课程榜”19门英语写作类MOOC课程。How to Write an Essay被列为250门全球最受欢迎MOOC课程之一,源于其优质的教学设计:世界顶尖大学及其丰富的在线课程经验、优秀师资...调研了美国Class Central网站发布的“2023年250门全球最受欢迎在线课程榜”19门英语写作类MOOC课程。How to Write an Essay被列为250门全球最受欢迎MOOC课程之一,源于其优质的教学设计:世界顶尖大学及其丰富的在线课程经验、优秀师资,教学目标注重培养学习者技能、终身学习理念以及抛锚式教学模式,这对于在线课程建设和教学具有借鉴意义。展开更多
Let G be a finite group, H ≤ G and R be a commutative ring with an identity 1R. Let CRG（H）={α ∈ RG｜αh = hα for all h ∈ H）, which is called the centralizer subalgebra of H in RG. Obviously, if H=G then CRG（H...Let G be a finite group, H ≤ G and R be a commutative ring with an identity 1R. Let CRG（H）={α ∈ RG｜αh = hα for all h ∈ H）, which is called the centralizer subalgebra of H in RG. Obviously, if H=G then CRG（H） is just the central subalgebra Z（RG） of RG. In this note, we show that the set of all H- conjugacy class sums of G forms an R-basis of CRG（H）. Furthermore, let N be a normal subgroup of G and γthe natural epimorphism from G to G to G/N. Then γ induces an epimorphism from RG to RG, also denoted by % We also show that if R is a field of characteristic zero, then γ induces an epimorphism from CRG（H） to CRG（H）, that is, 7（CRG（H）） = CRG（H）.展开更多
Let F be a number field and p be a prime. In the successive approximation theorem, we prove that, for each integer n ≥ 1, finitely many candidates for the Galois group of the nth stage of the p-class tower over F are...Let F be a number field and p be a prime. In the successive approximation theorem, we prove that, for each integer n ≥ 1, finitely many candidates for the Galois group of the nth stage of the p-class tower over F are determined by abelian type invariants of p-class groups C1pE of unramified extensions E/F with degree [E : F] = pn-1. Illustrated by the most extensive numerical results available currently, the transfer kernels (TE, F) of the p-class extensions TE, F : C1pF → C1pE from F to unramified cyclic degree-p extensions E/F are shown to be capable of narrowing down the number of contestants significantly. By determining the isomorphism type of the maximal subgroups S G of all 3-groups G with coclass cc(G) = 1, and establishing a general theorem on the connection between the p-class towers of a number field F and of an unramified abelian p-extension E/F, we are able to provide a theoretical proof of the realization of certain 3-groups S with maximal class by 3-tower groups of dihedral fields E with degree 6, which could not be realized up to now.展开更多
目的了解上海市三级甲等医院经外周静脉置入的中心静脉导管(peripherally inserted central catheter,PICC)维护的现状,以期为制订针对性的干预措施提供依据。方法 2014年9月至2015年1月,采用自制的"上海市三级甲等医院PICC维护情...目的了解上海市三级甲等医院经外周静脉置入的中心静脉导管(peripherally inserted central catheter,PICC)维护的现状,以期为制订针对性的干预措施提供依据。方法 2014年9月至2015年1月,采用自制的"上海市三级甲等医院PICC维护情况问卷"对上海市所有开展PICC技术的三级甲等医院及医院内主要PICC置管科室进行调查。结果上海市37所三级甲等医院中,30所开展了PICC技术,27所(90.0%)建立了PICC门诊,13所(43.3%)开展PICC维护的时间≥10年;开展PICC置管科室的科室中,96.1%的科室在穿刺部位仅使用透明敷料,61.3%的科室使用施乐扣固定导管,90.7%的科室使用肝素帽接头,76.0%的科室使用正压接头,70.7%的科室使用75%乙醇消毒接头,61.3%的科室使用2%葡萄糖酸氯己定乙醇溶液消毒皮肤,所有科室均使用10ml以上注射器冲封管,74.7%的科室使用生理盐水封管。结论各家医院开展了很多PICC的项目,但是在普及范围、专科护士资源、信息的获得以及导管维护实践的一致性方面还不足,建议完善PICC维护标准,加大专科培训力度,促进PICC专科化的发展。展开更多
目的:为提高医院中央空调系统的管理水平、降低中央空调系统运行能耗,对某院配置和实施中央空调自动控制系统。方法:根据某院中央空调系统的实际情况,分别对冷热源系统、空调箱系统和风机盘管系统进行自动控制,采用直接数字控制器(direc...目的:为提高医院中央空调系统的管理水平、降低中央空调系统运行能耗,对某院配置和实施中央空调自动控制系统。方法:根据某院中央空调系统的实际情况,分别对冷热源系统、空调箱系统和风机盘管系统进行自动控制,采用直接数字控制器(direct digital control,DDC)系统进行个性化编程和规范管理。结果:经过严格的调试和持续的运行,中央空调自控系统实现了对中央空调设备的远程管理和节能控制,取得了良好的经济效益和社会效益。结论:作为医院建筑能耗比例最大的中央空调系统,采用现代化的节能自控手段是非常必要的,对医院节能降耗具有重要的意义,可供同行参考、借鉴。展开更多
文摘调研了美国Class Central网站发布的“2023年250门全球最受欢迎在线课程榜”19门英语写作类MOOC课程。How to Write an Essay被列为250门全球最受欢迎MOOC课程之一,源于其优质的教学设计:世界顶尖大学及其丰富的在线课程经验、优秀师资,教学目标注重培养学习者技能、终身学习理念以及抛锚式教学模式,这对于在线课程建设和教学具有借鉴意义。
基金The NSF(11071155) of Chinathe NSF(2008A03) of Shandong Province
文摘Let G be a finite group, H ≤ G and R be a commutative ring with an identity 1R. Let CRG（H）={α ∈ RG｜αh = hα for all h ∈ H）, which is called the centralizer subalgebra of H in RG. Obviously, if H=G then CRG（H） is just the central subalgebra Z（RG） of RG. In this note, we show that the set of all H- conjugacy class sums of G forms an R-basis of CRG（H）. Furthermore, let N be a normal subgroup of G and γthe natural epimorphism from G to G to G/N. Then γ induces an epimorphism from RG to RG, also denoted by % We also show that if R is a field of characteristic zero, then γ induces an epimorphism from CRG（H） to CRG（H）, that is, 7（CRG（H）） = CRG（H）.
文摘Let F be a number field and p be a prime. In the successive approximation theorem, we prove that, for each integer n ≥ 1, finitely many candidates for the Galois group of the nth stage of the p-class tower over F are determined by abelian type invariants of p-class groups C1pE of unramified extensions E/F with degree [E : F] = pn-1. Illustrated by the most extensive numerical results available currently, the transfer kernels (TE, F) of the p-class extensions TE, F : C1pF → C1pE from F to unramified cyclic degree-p extensions E/F are shown to be capable of narrowing down the number of contestants significantly. By determining the isomorphism type of the maximal subgroups S G of all 3-groups G with coclass cc(G) = 1, and establishing a general theorem on the connection between the p-class towers of a number field F and of an unramified abelian p-extension E/F, we are able to provide a theoretical proof of the realization of certain 3-groups S with maximal class by 3-tower groups of dihedral fields E with degree 6, which could not be realized up to now.
文摘目的了解上海市三级甲等医院经外周静脉置入的中心静脉导管(peripherally inserted central catheter,PICC)维护的现状,以期为制订针对性的干预措施提供依据。方法 2014年9月至2015年1月,采用自制的"上海市三级甲等医院PICC维护情况问卷"对上海市所有开展PICC技术的三级甲等医院及医院内主要PICC置管科室进行调查。结果上海市37所三级甲等医院中,30所开展了PICC技术,27所(90.0%)建立了PICC门诊,13所(43.3%)开展PICC维护的时间≥10年;开展PICC置管科室的科室中,96.1%的科室在穿刺部位仅使用透明敷料,61.3%的科室使用施乐扣固定导管,90.7%的科室使用肝素帽接头,76.0%的科室使用正压接头,70.7%的科室使用75%乙醇消毒接头,61.3%的科室使用2%葡萄糖酸氯己定乙醇溶液消毒皮肤,所有科室均使用10ml以上注射器冲封管,74.7%的科室使用生理盐水封管。结论各家医院开展了很多PICC的项目,但是在普及范围、专科护士资源、信息的获得以及导管维护实践的一致性方面还不足,建议完善PICC维护标准,加大专科培训力度,促进PICC专科化的发展。
文摘目的:为提高医院中央空调系统的管理水平、降低中央空调系统运行能耗,对某院配置和实施中央空调自动控制系统。方法:根据某院中央空调系统的实际情况,分别对冷热源系统、空调箱系统和风机盘管系统进行自动控制,采用直接数字控制器(direct digital control,DDC)系统进行个性化编程和规范管理。结果:经过严格的调试和持续的运行,中央空调自控系统实现了对中央空调设备的远程管理和节能控制,取得了良好的经济效益和社会效益。结论:作为医院建筑能耗比例最大的中央空调系统,采用现代化的节能自控手段是非常必要的,对医院节能降耗具有重要的意义,可供同行参考、借鉴。
