Let us call a ring R (without identity) to be right symmetric if for any triple a,b,c,∈R?abc = 0 then acb = 0. Such rings are neither symmetric nor reversible (in general) but are semicommutative. With an idempotent ...Let us call a ring R (without identity) to be right symmetric if for any triple a,b,c,∈R?abc = 0 then acb = 0. Such rings are neither symmetric nor reversible (in general) but are semicommutative. With an idempotent they take care of the sheaf representation as obtained by Lambek. Klein 4-rings and their several generalizations and extensions are proved to be members of such class of rings. An extension obtained is a McCoy ring and its power series ring is also proved to be a McCoy ring.展开更多
This short exposition is about some commutativity conditions on a semiprime right Goldie Ck-ring. In particular, it is observed here that a semiprime right Goldie Ck-ring with symmetric quotient is commutative. The st...This short exposition is about some commutativity conditions on a semiprime right Goldie Ck-ring. In particular, it is observed here that a semiprime right Goldie Ck-ring with symmetric quotient is commutative. The statement holds if the symmetric ring is replaced by reduced, 2-primal, left duo, right duo, abelian, NI, NCI, IFP, or Armendariz ring.展开更多
本文阐述了两例犬血管环异常(vascular ring anomaly,VRA)的CT血管造影(CT angiography,CTA)诊断及手术治疗。通过术前对患犬进行CTA诊断,进行经左侧第4肋间开胸动脉韧带切断的手术治疗,并在术后对病例1进行食道球囊扩张。CTA显示两只...本文阐述了两例犬血管环异常(vascular ring anomaly,VRA)的CT血管造影(CT angiography,CTA)诊断及手术治疗。通过术前对患犬进行CTA诊断,进行经左侧第4肋间开胸动脉韧带切断的手术治疗,并在术后对病例1进行食道球囊扩张。CTA显示两只犬均存在持久性右主动脉弓(persistent right aortic arch,PRAA),并分别伴有右侧颈动脉异位发育和持久性左前腔静脉。手术治疗后,食道狭窄基本得到纠正,返流消失。CTA可对VRA进行更精确地诊断,并有助于制订具体手术方案;犬PRAA的手术治疗效果良好。展开更多
The potential for probing the impacts of the left-right symmetric model (LRM) on the process e + e-→μ + μ-at a proposed Z 0-factory is investigated.Under different electron-positron polarization collision modes,we ...The potential for probing the impacts of the left-right symmetric model (LRM) on the process e + e-→μ + μ-at a proposed Z 0-factory is investigated.Under different electron-positron polarization collision modes,we calculate and compare the deviations of various observables in the framework of the LRM from the standard model (SM) predictions,such as the total cross section,the distribution of the transverse momentum of μ-,and the forward-backward charge asymmetry of μ-.In addition,we present the relations between the observables and the LRM parameters.We conclude that it is possible to observe the effects of the LRM on the process e + e-→μ + μ-by using optimal observables and favorable parameters at a Z 0-factory.展开更多
文摘Let us call a ring R (without identity) to be right symmetric if for any triple a,b,c,∈R?abc = 0 then acb = 0. Such rings are neither symmetric nor reversible (in general) but are semicommutative. With an idempotent they take care of the sheaf representation as obtained by Lambek. Klein 4-rings and their several generalizations and extensions are proved to be members of such class of rings. An extension obtained is a McCoy ring and its power series ring is also proved to be a McCoy ring.
文摘This short exposition is about some commutativity conditions on a semiprime right Goldie Ck-ring. In particular, it is observed here that a semiprime right Goldie Ck-ring with symmetric quotient is commutative. The statement holds if the symmetric ring is replaced by reduced, 2-primal, left duo, right duo, abelian, NI, NCI, IFP, or Armendariz ring.
文摘本文阐述了两例犬血管环异常(vascular ring anomaly,VRA)的CT血管造影(CT angiography,CTA)诊断及手术治疗。通过术前对患犬进行CTA诊断,进行经左侧第4肋间开胸动脉韧带切断的手术治疗,并在术后对病例1进行食道球囊扩张。CTA显示两只犬均存在持久性右主动脉弓(persistent right aortic arch,PRAA),并分别伴有右侧颈动脉异位发育和持久性左前腔静脉。手术治疗后,食道狭窄基本得到纠正,返流消失。CTA可对VRA进行更精确地诊断,并有助于制订具体手术方案;犬PRAA的手术治疗效果良好。
基金supported in part by the National Natural Science Foundation of China (Grant Nos.10875112 and 10675110)
文摘The potential for probing the impacts of the left-right symmetric model (LRM) on the process e + e-→μ + μ-at a proposed Z 0-factory is investigated.Under different electron-positron polarization collision modes,we calculate and compare the deviations of various observables in the framework of the LRM from the standard model (SM) predictions,such as the total cross section,the distribution of the transverse momentum of μ-,and the forward-backward charge asymmetry of μ-.In addition,we present the relations between the observables and the LRM parameters.We conclude that it is possible to observe the effects of the LRM on the process e + e-→μ + μ-by using optimal observables and favorable parameters at a Z 0-factory.
