The interdependence of electrical parameters has long inhibited the progress of bismuth telluride(Bi_(2)Te3),limiting its widespread application in thermoelectric cooling and power generation.This work investigates th...The interdependence of electrical parameters has long inhibited the progress of bismuth telluride(Bi_(2)Te3),limiting its widespread application in thermoelectric cooling and power generation.This work investigates the n-type Bi_(2)Te_(2.79)Se_(0.21)I_(0.004)(Bi_(2)(Te,Se)_(3),BTS)system with light Zn doping,revealing that Zn addition simultaneously enhances the Seebeck coefficient(S)and electrical conductivity(σ)through the modulation of defect composition and multi-level band regulation.The substitution of Zn atoms at Bi sites enhances S via bandgap(E_(g))widening,band flattening,and band splitting effects,contributing to a competitive power factor(PF)of∼60μW⋅cm^(−1)⋅K^(−2).Additionally,thermal conductivity is maintained at a low level,leading to an extraordinary figure-of-merit(ZT)value of∼1.3 at room temperature.Furthermore,the Bi_(2)Zn_(0.01)Te_(2.79)Se_(0.21)I_(0.004) system demonstrates impressive thermoelectric device performance,with a maximum cooling temperature difference(ΔT_(max))of∼70.0 K at 300 K,rising to∼78.0 K at 323 K and∼85.7 K at 343 K,as well as a maximum conversion efficiency(η_(max))of∼6.2%under aΔT of 200 K.This study clarifies the mechanism of Zn doping and presents a cost-effective strategy for enhancing the performance of n-type BTS thermoelectrics and their devices.展开更多
Objective To study feasibility and value of repair of oral mandibular defects with rib composite flap pedicled with internal thoracic vessels in basic level hospitals. Methods The clinical materials in 13 cases uith m...Objective To study feasibility and value of repair of oral mandibular defects with rib composite flap pedicled with internal thoracic vessels in basic level hospitals. Methods The clinical materials in 13 cases uith mandibular defects which were repaired with rib compos-展开更多
Aim: Composite tissue defects encompassing bone and/or isolated bony defects can pose a surgical challenge;however, their reconstruction is critical for successful functional limb salvage. These cases become increasin...Aim: Composite tissue defects encompassing bone and/or isolated bony defects can pose a surgical challenge;however, their reconstruction is critical for successful functional limb salvage. These cases become increasingly problematic as secondary defects, following multiple nonvascularized grafting attempts resulting in complex bony nonunion. Herein, our experience utilizing fibula vascularized bone grafts (VBGs) for bone restoration will be presented to demonstrate their utility in a variety of reconstructions for limb salvage. Methods: This is a case series describing a series of vascularized fibula grafts for extremity reconstruction performed by a single academic surgeon over multiple institutions in seven years. Results: Twenty-seven (27) total VBGs met inclusion criteria and underwent reconstruction for traumatic (16), oncologic (6) and chronic degenerative (5) etiologies. Bony union was achieved in 26 of 27 cases. Conclusion: The decision-making process for bony reconstruction in these scenarios is difficult and multivariable. Fibula VBGs can provide a single-stage solution for autologous bony and soft tissue replacement of large or complex bone defects and can often be superior options compared with non-vascularized bone grafts or non-bone internal fixation techniques. Their osteogenic potential is unmatched by allogenic or synthetic substitutions. These benefits are evident in a variety of clinical settings such as pediatrics, oncology and trauma.展开更多
基金supported by the National Key Research and Development Program of China (Grant No.2024YFA1210400)the National Science Fund for Distinguished Young Scholars (Grant No.52525101)+3 种基金the National Natural Science Foundation of China (Grant Nos.52450001 and 22409014)the International Cooperation and Exchange of the National Natural Science Foundation of China (Grant No.52411540237)the Tencent Xplorer Prizethe support of the National High-Level Talent Special Support Programs—Young Talents。
文摘The interdependence of electrical parameters has long inhibited the progress of bismuth telluride(Bi_(2)Te3),limiting its widespread application in thermoelectric cooling and power generation.This work investigates the n-type Bi_(2)Te_(2.79)Se_(0.21)I_(0.004)(Bi_(2)(Te,Se)_(3),BTS)system with light Zn doping,revealing that Zn addition simultaneously enhances the Seebeck coefficient(S)and electrical conductivity(σ)through the modulation of defect composition and multi-level band regulation.The substitution of Zn atoms at Bi sites enhances S via bandgap(E_(g))widening,band flattening,and band splitting effects,contributing to a competitive power factor(PF)of∼60μW⋅cm^(−1)⋅K^(−2).Additionally,thermal conductivity is maintained at a low level,leading to an extraordinary figure-of-merit(ZT)value of∼1.3 at room temperature.Furthermore,the Bi_(2)Zn_(0.01)Te_(2.79)Se_(0.21)I_(0.004) system demonstrates impressive thermoelectric device performance,with a maximum cooling temperature difference(ΔT_(max))of∼70.0 K at 300 K,rising to∼78.0 K at 323 K and∼85.7 K at 343 K,as well as a maximum conversion efficiency(η_(max))of∼6.2%under aΔT of 200 K.This study clarifies the mechanism of Zn doping and presents a cost-effective strategy for enhancing the performance of n-type BTS thermoelectrics and their devices.
文摘Objective To study feasibility and value of repair of oral mandibular defects with rib composite flap pedicled with internal thoracic vessels in basic level hospitals. Methods The clinical materials in 13 cases uith mandibular defects which were repaired with rib compos-
文摘Aim: Composite tissue defects encompassing bone and/or isolated bony defects can pose a surgical challenge;however, their reconstruction is critical for successful functional limb salvage. These cases become increasingly problematic as secondary defects, following multiple nonvascularized grafting attempts resulting in complex bony nonunion. Herein, our experience utilizing fibula vascularized bone grafts (VBGs) for bone restoration will be presented to demonstrate their utility in a variety of reconstructions for limb salvage. Methods: This is a case series describing a series of vascularized fibula grafts for extremity reconstruction performed by a single academic surgeon over multiple institutions in seven years. Results: Twenty-seven (27) total VBGs met inclusion criteria and underwent reconstruction for traumatic (16), oncologic (6) and chronic degenerative (5) etiologies. Bony union was achieved in 26 of 27 cases. Conclusion: The decision-making process for bony reconstruction in these scenarios is difficult and multivariable. Fibula VBGs can provide a single-stage solution for autologous bony and soft tissue replacement of large or complex bone defects and can often be superior options compared with non-vascularized bone grafts or non-bone internal fixation techniques. Their osteogenic potential is unmatched by allogenic or synthetic substitutions. These benefits are evident in a variety of clinical settings such as pediatrics, oncology and trauma.
