This paper presents an accurate small-signal model for multi-gate GaAs pHEMTs in switching-mode.The extraction method for the proposed model is developed.A 2-gate switch structure is fabricated on a commercial 0.5μm ...This paper presents an accurate small-signal model for multi-gate GaAs pHEMTs in switching-mode.The extraction method for the proposed model is developed.A 2-gate switch structure is fabricated on a commercial 0.5μm AlGaAs/GaAs pHEMT technology to verify the proposed model.Excellent agreement has been obtained between the measured and simulated results over a wide frequency range.展开更多
In this paper,we study minimal Legendrian surfacesΣimmersed in the tangent sphere bundle T_(1)R^(3).We classify(1)totally geodesic Legendrian surfaces,(2)closed minimal Legendrian surfaces of genus smaller than or eq...In this paper,we study minimal Legendrian surfacesΣimmersed in the tangent sphere bundle T_(1)R^(3).We classify(1)totally geodesic Legendrian surfaces,(2)closed minimal Legendrian surfaces of genus smaller than or equal to 1 and complete minimal Legendrian surfaces with the non-negative Gauss curvature,and(3)complete stable minimal Legendrian surfaces.展开更多
In this paper,we first introduce a boundary problem for Lagrangian submanifolds,analogous to the problem for free boundary hypersurfaces and capillary hypersurfaces.Then we present several interesting examples of Lagr...In this paper,we first introduce a boundary problem for Lagrangian submanifolds,analogous to the problem for free boundary hypersurfaces and capillary hypersurfaces.Then we present several interesting examples of Lagrangian submanifolds satisfying this boundary condition and we prove a Lagrangian version of the Nitsche(or Hopf)type theorem.Some problems are proposed at the end of this paper.展开更多
This is a survey about our recent works on the Gauss-Bonnet-Chern （GBC） mass for asymptotically flat and asymptotically hyperbolic manifolds. We first introduce the GBC mass, a higher order mass, for asymptotically ...This is a survey about our recent works on the Gauss-Bonnet-Chern （GBC） mass for asymptotically flat and asymptotically hyperbolic manifolds. We first introduce the GBC mass, a higher order mass, for asymptotically flat and for asymptotically hyperbolic manifolds, respectively, by using a higher order scalar curvature. Then we prove its positivity and the Penrose inequality for graphical manifolds. One of the crucial steps in the proof of the Penrose inequality is the use of an Alexandrov-Fenchel inequality, which is a classical^inequality in the Euclidean space. In the hyperbolic space, we have established this new Alexandrov-Fenchel inequality. We also have a similar work for asymptotically locally hyperbolic manifolds. At the end, we discuss the relation between the GBC mass and Chern＇s magic form.展开更多
Toxicity assessment is a major problem in pharmaceutical candidates and industry chemicals development.However,due to the lack of practical analytical methods for DNA adduct analysis,the safety evaluation of drug and ...Toxicity assessment is a major problem in pharmaceutical candidates and industry chemicals development.However,due to the lack of practical analytical methods for DNA adduct analysis,the safety evaluation of drug and industry chemicals was severely limited.Here,we develop a DNAzyme-based method to detect DNA adduct damage for toxicity assessment of drugs and chemicals.Among 18 structural variants of G4 DNAzyme,EA2 DNAzyme exhibits an obvious DNA damaging effect of styrene oxide(SO)due to its unstable structure.The covalent binding of SO to DNAzyme disrupts the Hoogsteen hydrogen bonding sites of G-plane guanines and affects the formation of the G4 quadruplex.DNA damage chemicals reduce the peroxidase activity of the G4 DNAzyme to monitor the DNA adduct damage by disrupting the structural integrity of the G4 DNAzyme.Our method for genotoxic assessment of pharmaceutical candidates and industrial chemicals can elucidate the complex chemical pathways leading to toxicity,predict toxic effects of chemicals,and evaluate possible risks to human health.展开更多
We show that on a Sasakian 3-sphere the Sasaki-Ricci flow initiating from a Sasakian metric of positive transverse scalar curvature converges to a gradient Sasaki-Ricci soliton.We also show the existence and uniquenes...We show that on a Sasakian 3-sphere the Sasaki-Ricci flow initiating from a Sasakian metric of positive transverse scalar curvature converges to a gradient Sasaki-Ricci soliton.We also show the existence and uniqueness of gradient Sasaki-Ricci soliton on each Sasakian 3-sphere.展开更多
文摘This paper presents an accurate small-signal model for multi-gate GaAs pHEMTs in switching-mode.The extraction method for the proposed model is developed.A 2-gate switch structure is fabricated on a commercial 0.5μm AlGaAs/GaAs pHEMT technology to verify the proposed model.Excellent agreement has been obtained between the measured and simulated results over a wide frequency range.
基金supported by National Natural Science Foundation of China(Grant No.11901534)。
文摘In this paper,we study minimal Legendrian surfacesΣimmersed in the tangent sphere bundle T_(1)R^(3).We classify(1)totally geodesic Legendrian surfaces,(2)closed minimal Legendrian surfaces of genus smaller than or equal to 1 and complete minimal Legendrian surfaces with the non-negative Gauss curvature,and(3)complete stable minimal Legendrian surfaces.
基金supported by SPP 2026:Geometry at Infinity of Deutsche Forschungsgemeinschaft.A part of this work was carried out when the second author visited the University of British Columbia。
文摘In this paper,we first introduce a boundary problem for Lagrangian submanifolds,analogous to the problem for free boundary hypersurfaces and capillary hypersurfaces.Then we present several interesting examples of Lagrangian submanifolds satisfying this boundary condition and we prove a Lagrangian version of the Nitsche(or Hopf)type theorem.Some problems are proposed at the end of this paper.
基金Acknowledgements The most part of this survey was talked in the conference ＂Metric Riemannian Geometry Workshop＂ held in Shanghai Jiao Tong University, Shanghai, China. The authors would like to take this opportunity to thank the organizers both from China and from Germany. This work was partly supported by SFB/TR71 ＂Geometric partial differential equations＂ of DFG. JW was supported by the National Natural Science Foundation of China （Grant No. 11401553） and CX in part by the Fundamental Research Funds for the Central Universities （Grant No. 20720150012） and the National Natural Science Foundation of China （Grant No. 11501480）.
文摘This is a survey about our recent works on the Gauss-Bonnet-Chern （GBC） mass for asymptotically flat and asymptotically hyperbolic manifolds. We first introduce the GBC mass, a higher order mass, for asymptotically flat and for asymptotically hyperbolic manifolds, respectively, by using a higher order scalar curvature. Then we prove its positivity and the Penrose inequality for graphical manifolds. One of the crucial steps in the proof of the Penrose inequality is the use of an Alexandrov-Fenchel inequality, which is a classical^inequality in the Euclidean space. In the hyperbolic space, we have established this new Alexandrov-Fenchel inequality. We also have a similar work for asymptotically locally hyperbolic manifolds. At the end, we discuss the relation between the GBC mass and Chern＇s magic form.
基金This work was supported by National Natural Science Foundation of China(81803720)Natural Science Foundation of Hunan Province(2019JJ50383)+3 种基金Natural Science Foundation of Changsha(kq2202256)Huxiang High-Level Talent Innovation Team(2018RS3072)Scientific and Technological Projects for Collaborative Prevention and Control of Birth Defect in Hunan Province(2019SK1012)Key Grant of Research and Development in Hunan Province(2020DK2002).Dr.Zhang acknowledges the support from Harvard/MIT.
文摘Toxicity assessment is a major problem in pharmaceutical candidates and industry chemicals development.However,due to the lack of practical analytical methods for DNA adduct analysis,the safety evaluation of drug and industry chemicals was severely limited.Here,we develop a DNAzyme-based method to detect DNA adduct damage for toxicity assessment of drugs and chemicals.Among 18 structural variants of G4 DNAzyme,EA2 DNAzyme exhibits an obvious DNA damaging effect of styrene oxide(SO)due to its unstable structure.The covalent binding of SO to DNAzyme disrupts the Hoogsteen hydrogen bonding sites of G-plane guanines and affects the formation of the G4 quadruplex.DNA damage chemicals reduce the peroxidase activity of the G4 DNAzyme to monitor the DNA adduct damage by disrupting the structural integrity of the G4 DNAzyme.Our method for genotoxic assessment of pharmaceutical candidates and industrial chemicals can elucidate the complex chemical pathways leading to toxicity,predict toxic effects of chemicals,and evaluate possible risks to human health.
文摘We show that on a Sasakian 3-sphere the Sasaki-Ricci flow initiating from a Sasakian metric of positive transverse scalar curvature converges to a gradient Sasaki-Ricci soliton.We also show the existence and uniqueness of gradient Sasaki-Ricci soliton on each Sasakian 3-sphere.
