A 4H-SiC trench gate metal-oxide-semiconductor field-effect transistor(UMOSFET)with semi-super-junction shiel-ded structure(SS-UMOS)is proposed and compared with conventional trench MOSFET(CT-UMOS)in this work.The adv...A 4H-SiC trench gate metal-oxide-semiconductor field-effect transistor(UMOSFET)with semi-super-junction shiel-ded structure(SS-UMOS)is proposed and compared with conventional trench MOSFET(CT-UMOS)in this work.The advantage of the proposed structure is given by comprehensive study of the mechanism of the local semi-super-junction structure at the bottom of the trench MOSFET.In particular,the influence of the bias condition of the p-pillar at the bottom of the trench on the static and dynamic performances of the device is compared and revealed.The on-resistance of SS-UMOS with grounded(G)and ungrounded(NG)p-pillar is reduced by 52%(G)and 71%(NG)compared to CT-UMOS,respectively.Additionally,gate ox-ide in the GSS-UMOS is fully protected by the p-shield layer as well as semi-super-junction structure under the trench and p-base regions.Thus,a reduced electric-field of 2 MV/cm can be achieved at the corner of the p-shield layer.However,the quasi-intrinsic protective layer cannot be formed in NGSS-UMOS due to the charge storage effect in the floating p-pillar,resulting in a large electric field of 2.7 MV/cm at the gate oxide layer.Moreover,the total switching loss of GSS-UMOS is 1.95 mJ/cm2 and is reduced by 18%compared with CT-UMOS.On the contrary,the NGSS-UMOS has the slowest overall switching speed due to the weakened shielding effect of the p-pillar and the largest gate-to-drain capacitance among the three.The proposed GSS-UMOS plays an important role in high-voltage and high-frequency applications,and will provide a valuable idea for device design and circuit applications.展开更多
New generation passive optical network aims at providing more than 100 Gb/s capacity. Thanks to recent progress enabling a variety of optical transceivers up to 40 Gb/s, many evolution possibilities to 200G PONs （pas...New generation passive optical network aims at providing more than 100 Gb/s capacity. Thanks to recent progress enabling a variety of optical transceivers up to 40 Gb/s, many evolution possibilities to 200G PONs （passive optical network） could be investigated. This work proposes two directly deployable cases of evolution to 200G PON based on the combination of these improved optical transceivers and WDM （wavelength division multiplexing）. The physical layer of the optical network has been simulated with OptiSystem software to show the communication links performances behavior when considering key components parameters in order to achieve good network design for a given area. The complexity of the proposed architectures and financial cost comparisons are also discussed.展开更多
Objective To introduce the experience of professor YIN Ke-jing,a national senior and famous doctor of traditional Chinese medicine,in treatment of abdominal distension after abdominal surgery with warming-needle moxib...Objective To introduce the experience of professor YIN Ke-jing,a national senior and famous doctor of traditional Chinese medicine,in treatment of abdominal distension after abdominal surgery with warming-needle moxibustion at Gōngsūn（公孙 SP 4）.Methods Bilateral SP 4 were selected,and warming-needle moxibustion was adopted.The treatment was conducted for twice a day,and treatment for 3 days was considered as 1 course of treatment.The efficacy was evaluated after 2 courses.Results The total effective rate was 96.9% of the 32 patients after treatment and observation for 2 courses.Conclusion This therapeutic method was easy and simple with less acupoints selected and rapid onset of effect.With definite clinical efficacy,this method was worthy of being popularized.展开更多
A 1942 meeting of T.S.Eliot in a BBC recording studio with George Orwell,alongside several Caribbean and British Indian writers of color,suggests a multicultural vision of high modernism that never quite happened.The ...A 1942 meeting of T.S.Eliot in a BBC recording studio with George Orwell,alongside several Caribbean and British Indian writers of color,suggests a multicultural vision of high modernism that never quite happened.The exemplary modernism of Eliot's The Waste Land prompted a number of imitations,extensions,and experiments,only some of which made it into subsequent literary history.This paper concerns two modernist nonhappenings,Epistle to Prometheus by Babette Deutsch and F.M.S.R.by Francis P.Ng.Epistle to Prometheus^a book-length poem combining Eliotic modernist ambition and broadly left politics,was suppressed by the author almost immediately after publication for reasons that remain obscure.F.M.S.R.,a long poem in the Eliot tradition addressing a train journey between Singapore and Kuala Lumpur,was completely lost until recently discovered and the author(Teo Poh Leng)identified.The diversity of approaches in these poems shows how,in the postwar years,modernism was retroactively unified,and how many approaches,including some taking Eliot's influences in unusual directions,have been lost to history.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.62104222)the Natural Science Foundation of Fujian Province of China for Distinguished Young Scholars(Grant No.2020J06002)+3 种基金the Science and Technology Project of Fujian Province of China(Grant No.2020I0001)the Science and Technology Key Projects of Xiamen(Grant No.3502ZCQ20191001)Shenzhen Science and Technology Program(Grant No.JSGG20201102-155800003)Jiangxi Provincial Natural Science Foundation(Grant No.20212ACB212005).
文摘A 4H-SiC trench gate metal-oxide-semiconductor field-effect transistor(UMOSFET)with semi-super-junction shiel-ded structure(SS-UMOS)is proposed and compared with conventional trench MOSFET(CT-UMOS)in this work.The advantage of the proposed structure is given by comprehensive study of the mechanism of the local semi-super-junction structure at the bottom of the trench MOSFET.In particular,the influence of the bias condition of the p-pillar at the bottom of the trench on the static and dynamic performances of the device is compared and revealed.The on-resistance of SS-UMOS with grounded(G)and ungrounded(NG)p-pillar is reduced by 52%(G)and 71%(NG)compared to CT-UMOS,respectively.Additionally,gate ox-ide in the GSS-UMOS is fully protected by the p-shield layer as well as semi-super-junction structure under the trench and p-base regions.Thus,a reduced electric-field of 2 MV/cm can be achieved at the corner of the p-shield layer.However,the quasi-intrinsic protective layer cannot be formed in NGSS-UMOS due to the charge storage effect in the floating p-pillar,resulting in a large electric field of 2.7 MV/cm at the gate oxide layer.Moreover,the total switching loss of GSS-UMOS is 1.95 mJ/cm2 and is reduced by 18%compared with CT-UMOS.On the contrary,the NGSS-UMOS has the slowest overall switching speed due to the weakened shielding effect of the p-pillar and the largest gate-to-drain capacitance among the three.The proposed GSS-UMOS plays an important role in high-voltage and high-frequency applications,and will provide a valuable idea for device design and circuit applications.
文摘New generation passive optical network aims at providing more than 100 Gb/s capacity. Thanks to recent progress enabling a variety of optical transceivers up to 40 Gb/s, many evolution possibilities to 200G PONs （passive optical network） could be investigated. This work proposes two directly deployable cases of evolution to 200G PON based on the combination of these improved optical transceivers and WDM （wavelength division multiplexing）. The physical layer of the optical network has been simulated with OptiSystem software to show the communication links performances behavior when considering key components parameters in order to achieve good network design for a given area. The complexity of the proposed architectures and financial cost comparisons are also discussed.
文摘Objective To introduce the experience of professor YIN Ke-jing,a national senior and famous doctor of traditional Chinese medicine,in treatment of abdominal distension after abdominal surgery with warming-needle moxibustion at Gōngsūn（公孙 SP 4）.Methods Bilateral SP 4 were selected,and warming-needle moxibustion was adopted.The treatment was conducted for twice a day,and treatment for 3 days was considered as 1 course of treatment.The efficacy was evaluated after 2 courses.Results The total effective rate was 96.9% of the 32 patients after treatment and observation for 2 courses.Conclusion This therapeutic method was easy and simple with less acupoints selected and rapid onset of effect.With definite clinical efficacy,this method was worthy of being popularized.
文摘A 1942 meeting of T.S.Eliot in a BBC recording studio with George Orwell,alongside several Caribbean and British Indian writers of color,suggests a multicultural vision of high modernism that never quite happened.The exemplary modernism of Eliot's The Waste Land prompted a number of imitations,extensions,and experiments,only some of which made it into subsequent literary history.This paper concerns two modernist nonhappenings,Epistle to Prometheus by Babette Deutsch and F.M.S.R.by Francis P.Ng.Epistle to Prometheus^a book-length poem combining Eliotic modernist ambition and broadly left politics,was suppressed by the author almost immediately after publication for reasons that remain obscure.F.M.S.R.,a long poem in the Eliot tradition addressing a train journey between Singapore and Kuala Lumpur,was completely lost until recently discovered and the author(Teo Poh Leng)identified.The diversity of approaches in these poems shows how,in the postwar years,modernism was retroactively unified,and how many approaches,including some taking Eliot's influences in unusual directions,have been lost to history.
