In this paper the projective semi symmetric connection D is studied, which is projectively equivalent to the Levi_Civita connection . An intrinsic projective invariant is found out and a necessary and suffici...In this paper the projective semi symmetric connection D is studied, which is projectively equivalent to the Levi_Civita connection . An intrinsic projective invariant is found out and a necessary and sufficient condition is given. Furthermore, another condition is obtained when the convariant derivative of the projective invariant is kept.展开更多
This paper deals with the study of CR-submanifolds of a nearly trans-Sasakian manifold with a semi symmetric non-metric connection. Nijenhuis tensor, integrability conditions for some distributions on CR-submanifolds ...This paper deals with the study of CR-submanifolds of a nearly trans-Sasakian manifold with a semi symmetric non-metric connection. Nijenhuis tensor, integrability conditions for some distributions on CR-submanifolds of a nearly trans-Sasakian manifold with a semi symmetric non- metric connection are discussed.展开更多
In this work,it is proved that every isotropic Weyl manifold with a semi- symmetric connection is locally conformal to an Einstein manifold with a semi-symmetric connection.
In this paper, we obtain Chen’s inequalities in (k,?μ)-contact space form with a semi-symmetric non-metric connection. Also we obtain the inequalites for Ricci and K-Ricci curvatures.
In this work,it is proved that every isotropic Weyl manifold with a semi- symmetric connection is locally conformal to an Einstein manifold with a semi-symmetric connection.
To enhance the reverse blocking capability with low specific on-resistance,a novel vertical metal-oxidesemiconductor field-effect transistor（MOSFET） with a Schottky-drian（SD） and SD-connected semisuperjunctions（S...To enhance the reverse blocking capability with low specific on-resistance,a novel vertical metal-oxidesemiconductor field-effect transistor（MOSFET） with a Schottky-drian（SD） and SD-connected semisuperjunctions（SDD-semi-SJ）,named as SD-D-semi-SJ MOSFET is proposed and demonstrated by two-dimensional（2D） numerical simulations.The SD contacted with the n-pillar exhibits the Schottky-contact property,and that with the p-pillar the Ohmic-contact property.Based on these features,the SD-D-semi-SJ MOSFET could obviously overcome the great obstacle of the ineffectivity of the conventional superjunctions（SJ） or semisuperjunctions（semi-SJ） for the reverse applications and achieve a satisfactory trade-off between the reverse breakdown voltage（BV） and the specific on-resistance（R_（on）A）.For a given pillar width and n-drift thickness,there exists a proper range of n-drift concentration（N）,in which the SD-D-semi-SJ MOSFET could exhibit a better trade-off of R_（on）A-BV compared to the predication of SJ MOSFET in the forward applications.And what is much valuable,in this proper range of N,the desired BV and good trade-off could be achieved only by determining the pillar thickness,with the top assist layer thickness unchanged.Detailed analyses have been carried out to get physical insights into the intrinsic mechanism of R_（on）A-BV improvement in SD-D-semi-SJ MOSFET.These results demonstrate a great potential of SD-D-semi-SJ MOSFET in reverse applications.展开更多
文摘In this paper the projective semi symmetric connection D is studied, which is projectively equivalent to the Levi_Civita connection . An intrinsic projective invariant is found out and a necessary and sufficient condition is given. Furthermore, another condition is obtained when the convariant derivative of the projective invariant is kept.
文摘This paper deals with the study of CR-submanifolds of a nearly trans-Sasakian manifold with a semi symmetric non-metric connection. Nijenhuis tensor, integrability conditions for some distributions on CR-submanifolds of a nearly trans-Sasakian manifold with a semi symmetric non- metric connection are discussed.
文摘In this work,it is proved that every isotropic Weyl manifold with a semi- symmetric connection is locally conformal to an Einstein manifold with a semi-symmetric connection.
文摘In this paper, we obtain Chen’s inequalities in (k,?μ)-contact space form with a semi-symmetric non-metric connection. Also we obtain the inequalites for Ricci and K-Ricci curvatures.
文摘In this work,it is proved that every isotropic Weyl manifold with a semi- symmetric connection is locally conformal to an Einstein manifold with a semi-symmetric connection.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61574112,61334002,61306017,61474091,and 61574110)the Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.605119425012)
文摘To enhance the reverse blocking capability with low specific on-resistance,a novel vertical metal-oxidesemiconductor field-effect transistor（MOSFET） with a Schottky-drian（SD） and SD-connected semisuperjunctions（SDD-semi-SJ）,named as SD-D-semi-SJ MOSFET is proposed and demonstrated by two-dimensional（2D） numerical simulations.The SD contacted with the n-pillar exhibits the Schottky-contact property,and that with the p-pillar the Ohmic-contact property.Based on these features,the SD-D-semi-SJ MOSFET could obviously overcome the great obstacle of the ineffectivity of the conventional superjunctions（SJ） or semisuperjunctions（semi-SJ） for the reverse applications and achieve a satisfactory trade-off between the reverse breakdown voltage（BV） and the specific on-resistance（R_（on）A）.For a given pillar width and n-drift thickness,there exists a proper range of n-drift concentration（N）,in which the SD-D-semi-SJ MOSFET could exhibit a better trade-off of R_（on）A-BV compared to the predication of SJ MOSFET in the forward applications.And what is much valuable,in this proper range of N,the desired BV and good trade-off could be achieved only by determining the pillar thickness,with the top assist layer thickness unchanged.Detailed analyses have been carried out to get physical insights into the intrinsic mechanism of R_（on）A-BV improvement in SD-D-semi-SJ MOSFET.These results demonstrate a great potential of SD-D-semi-SJ MOSFET in reverse applications.
