目的:研究MRI 3D CUBE T_(2)序列检查在踝关节外伤患者韧带损伤诊断中的价值。方法:选择2020年4月—2023年4月于白银市第一人民医院就诊的226例踝关节外伤拟行手术术前患者作为研究对象,按照不同检查方式将患者分为观察组(n=126)与对照...目的:研究MRI 3D CUBE T_(2)序列检查在踝关节外伤患者韧带损伤诊断中的价值。方法:选择2020年4月—2023年4月于白银市第一人民医院就诊的226例踝关节外伤拟行手术术前患者作为研究对象,按照不同检查方式将患者分为观察组(n=126)与对照组(n=100)。观察组采用MRI 3D CUBE T_(2)序列检查,对照组采取常规MRI检查。比较两组患侧、健侧距腓前韧带测量结果、诊断效能。结果:两组患侧、健侧距腓前韧带宽度及厚度比较,差异无统计学意义(P>0.05)。观察组Ⅰ级踝关节外伤患者韧带损伤诊断准确度、敏感度、特异度、阳性预测值、阴性预测值高于对照组,Ⅱ级患者准确度、敏感度、阴性预测值高于对照组,Ⅲ级患者准确度、特异度、阳性预测值高于对照组,差异有统计学意义(P<0.05)。结论:MRI 3D CUBE T_(2)序列检查踝关节外伤患者韧带损伤诊断效能高于常规MRI检查,可作为治疗效果评价及康复治疗的重要依据。展开更多
By using scanning tunneling microscopy,we investigated the electronic evolution of T_(d)-WTe_(2) via in-situ surface alkali K atoms deposition.The T_(d)-WTe_(2) surface is electron doped upon K deposition,and as the K...By using scanning tunneling microscopy,we investigated the electronic evolution of T_(d)-WTe_(2) via in-situ surface alkali K atoms deposition.The T_(d)-WTe_(2) surface is electron doped upon K deposition,and as the K coverage increases,two gaps are sequentially opened near Fermi energy,which probably indicates that two phase transitions concomitantly occur during electron doping.The two gaps both show a dome-like dependence on the K coverage.While the bigger gap shows no prominent dependence on the magnetic field,the smaller one can be well suppressed and thus possibly corresponds to the superconducting transition.This work indicates that T_(d)-WTe_(2) exhibits rich quantum states closely related to the carrier concentration.展开更多
Two-dimensional(2D)perovskites solar cells(PSCs)have attracted considerable attention owing to their excellent stability against humidity;however,some imperfectness of 2D perovskites,such as poor crystallinity,disorde...Two-dimensional(2D)perovskites solar cells(PSCs)have attracted considerable attention owing to their excellent stability against humidity;however,some imperfectness of 2D perovskites,such as poor crystallinity,disordered orientation,and inferior charge transport still limit the power conversion efficiency(PCE)of 2D PSCs.In this work,2D Ti3C2Tx MXene nanosheets with high electrical conductivity and mobility were employed as a nanosized additive to prepare 2D Ruddlesden–Popper perovskite films.The PCE of solar cells was increased from 13.69(without additive)to 15.71%after incorporating the Ti_(3)C_(2)T_(x) nanosheets with an optimized concentration.This improved performance is attributed to the enhanced crystallinity,orientation,and passivated trap states in the 3D phase that result in accelerated charge transfer process in vertical direction.More importantly,the unencapsulated cells exhibited excellent stability under ambient conditions with 55±5%relative humidity.展开更多
The actual manufacture of supercapacitors(SCs)is restricted by the inadequate energy density,and the energy density of devices can be properly promoted by assembling zinc-ion capacitors(ZICs)which used capacitive cath...The actual manufacture of supercapacitors(SCs)is restricted by the inadequate energy density,and the energy density of devices can be properly promoted by assembling zinc-ion capacitors(ZICs)which used capacitive cathode and battery-type anode.Two-dimensional(2D)MXene has brought great focuses in the electrode research on the foundation of large redox-active surface,but the specific capacitance is still affected by the tight stacking of interlaminations.Ti_(3)C_(2)T_(x)@polyaniline(PANI)heterostructures are prepared by uniformly depositing the conductive polymer PANI nanorods as the intercalation agent into the external of Ti_(3)C_(2)T_(x)nanosheets to inhibit stacking.Subsequently,by using graphene oxide(GO)-assisted low-temperature hydrothermal self-assembly manufacture,2D heterostructures are assembled into the three-dimensional(3D)porous crosslinked Ti_(3)C_(2)T_(x)@PANI-reduced graphene oxide(RGO)hydrogels.Attributed to the synergistic work of PANI nanorods,Ti_(3)C_(2)T_(X)nanosheets,and 3D crosslinking frameworks of RGO to match capacitive and battery effects,3D porous hierarchical Ti_(3)C_(2)T_(x)@PANI-RGO heterostructure hydrogels have rich ion transport channels,a large number of active sites,and excellent reaction kinetics.ZIC is assembled by using Ti_(3)C_(2)T_(x)@PANI-RGO heterostructure hydrogels as cathodes and zinc foil as anodes.In this work,Ti_(3)C_(2)T_(x)@PANI-RGO//Zn ZIC exhibits a wide working window(2.0 V),marked specific capacitance(589.89 F·g^(−1)at 0.5 A·g−1),salient energy density(327.71 Wh·kg^(−1)at 513.61 W·kg^(−1)and 192.20 Wh·kg^(−1)at 13,005.87 W·kg^(−1)),and durable cycling stability(97.87%capacitance retention after 10,000 cycles at 10 A·g^(−1)).This study emphasizes the device design of ZICs and the broad prospect of Ti_(3)C_(2)T_(x)-based hydrogels as viable cathodes for ZICs.展开更多
Catalysis has been regarded as an effective strategy to mitigate sluggish reaction kinetics and serious shuttle effect of Li-S batteries.Herein,a spherical structure consists of ultrathin layered Ti_(3)C_(2)T_(x)-TiN ...Catalysis has been regarded as an effective strategy to mitigate sluggish reaction kinetics and serious shuttle effect of Li-S batteries.Herein,a spherical structure consists of ultrathin layered Ti_(3)C_(2)T_(x)-TiN heterostructures(MX-TiN)through in-situ nitridation method is reported.Through controllable nitridation,highly conductive TiN layer grew on the surface and close coupled with interior MXene to form unique 2D heterostructures.The ultrathin heterostructure with only several nanometers in thickness enables outstanding ability to shorten electrons diffusion distance during electrochemical reactions and enlarge active surface with abundant adsorptive and catalytic sites.Moreover,the(001)surface of TiN is dominated by metallic Ti-3d states,which ensures fast transmitting electrons from high conductive MX-TiN matrix and thus guarantees efficient catalytic performance.Calculations and experiments demonstrate that polysulfides are strongly immobilized on MX-TiN,meanwhile the bidirectional reaction kinetics are catalytically enhanced by reducing the conversion barrier between liquid LiPSs and solid Li_(2)S_(2)/Li_(2)S.As a result,the S/MX-TiN cathode achieves excellent long-term cyclability with extremely low-capacity fading rate of 0.022%over 1000 cycles and remarkable areal capacity of 8.27 mAh cm^(−2) at high sulfur loading and lean electrolytes.展开更多
Lithium-sulfur(Li-S) batteries are one of the most promising rechargeable storage devices due to the high theoretical energy density.However,the low areal sulfur loading impedes their commercial development.Herein,a 3...Lithium-sulfur(Li-S) batteries are one of the most promising rechargeable storage devices due to the high theoretical energy density.However,the low areal sulfur loading impedes their commercial development.Herein,a 3 D free-standing sulfur cathode scaffold is rationally designed and fabricated by coaxially coating polar Ti_3 C_2 T_x flakes on sulfur-impregnated carbon cloth(Ti_3 C_2 T_x@S/CC) to achieve high loading and high energy density Li-S batteries,in which,the flexible CC substrate with highly porous structure can accommodate large amounts of sulfur and ensure fast electron transfer,while the outer-coated Ti_3 C_2 T_x can serve as a polar and conductive protective layer to further promote the conductivity of the whole electrode,achieve physical blocking and chemical anchoring of lithium-polysulfides as well as catalyze their conversion.Due to these advantages,at a sulfur loading of 4 mg cm^(-2),Li-S cells with Ti_3 C_2 T_x@S/CC cathodes can deliver outstanding cycling stability(746.1 mAh g^(-1) after 200 cycles at1 C),superb rate performance(866.8 mAh g^(-1) up to 2 C) and a high specific energy density(564.2 Wh kg^(-1) after 100 cycles at 0.5 C).More significantly,they also show the commercial potential that can compete with current lithium-ion batteries due to the high areal capacity of 6.7 mAh cm^(-2) at the increased loading of 8 mg cm^(-2).展开更多
Two-/three-dimensional(2D/3D)heterojunction-based photodetectors have attracted much attention due to their highly efficient photoelectric conversion driven by the built-in electric field for high-speed photoresponse....Two-/three-dimensional(2D/3D)heterojunction-based photodetectors have attracted much attention due to their highly efficient photoelectric conversion driven by the built-in electric field for high-speed photoresponse.However,a large dark current induced by unexpected surface states at the interface between 2D materials and 3D bulks is widely observed in such structures,greatly degrading their optoelectronic performance.Herein,a heterojunction of proton acid HCl treated MXene(H-MXene)/TiO_(2)/Si via integrating surface and interface engineering is fabricated,which exhibits decreased dark current and improved environmental stability.A feasible strategy to optimize the interface properties between MXene and Si is proposed by an in-situ oxidation process of MXene into TiO_(2),resulting in a suppressed dark current as well as high specific detectivity.Benefitting from the enhanced light absorption of MXene on the bulk Si substrate,the photoresponse of as-fabricated devices in the near-infrared region is also elevated.Moreover,the treatment of proton acid HCl on the surface of MXene brings better conductivity and environmental stability due to the decreased layer spacing of MXene,which is further confirmed by both experimental and theoretical methods.This work opens a unique way to comprehensively boost the optoelectronic performance of MXene-based photodetectors.展开更多
This work proposes a facile fabrication strategy for thermally conductive graphite nanosheets/poly(lactic acid) sheets with ordered GNPs(o-GNPs/PLA) via fused deposition modeling(FDM) 3 D printing technology.Further c...This work proposes a facile fabrication strategy for thermally conductive graphite nanosheets/poly(lactic acid) sheets with ordered GNPs(o-GNPs/PLA) via fused deposition modeling(FDM) 3 D printing technology.Further combinations of o-GNPs/PLA with Ti_(3) C_(2) T_(x) films prepared by vacuum-assisted filtration were carried out by "layer-by-layer stacking-hot pressing" to be the thermally conductive Ti_(3) C_(2) T_(x)/(oGNPs/PLA) composites with superior electromagnetic interference shielding effectiveness(EMI SE).When the content of GNPs was 18.60 wt%and 4 layers of Ti_(3) C_(2) T_(x)(6.98 wt%) films were embedded,the in-plane thermal conductivity coefficient(λ_(Ⅱ)) and EMI SE(EMI SE_(Ⅱ)) values of the thermally conductive Ti_(3) C_(2) T_(x)/(o-GNPs/P LA) composites significantly increa sed to 3.44 W·m^(-1)·K^(-1) and 65 d B(3.00 mm),increased by 1223.1% and2066.7%,respectively,compared with λ_(Ⅱ)(0.26 W·m^(-1)·K^(-1)) and EMI SE_(Ⅱ)(3 d B) of neat PLA matrix.This work offers a novel and easily route for designing and manufacturing highly thermally conductive polymer composites with superior EMI SE for broader application.展开更多
文摘目的:研究MRI 3D CUBE T_(2)序列检查在踝关节外伤患者韧带损伤诊断中的价值。方法:选择2020年4月—2023年4月于白银市第一人民医院就诊的226例踝关节外伤拟行手术术前患者作为研究对象,按照不同检查方式将患者分为观察组(n=126)与对照组(n=100)。观察组采用MRI 3D CUBE T_(2)序列检查,对照组采取常规MRI检查。比较两组患侧、健侧距腓前韧带测量结果、诊断效能。结果:两组患侧、健侧距腓前韧带宽度及厚度比较,差异无统计学意义(P>0.05)。观察组Ⅰ级踝关节外伤患者韧带损伤诊断准确度、敏感度、特异度、阳性预测值、阴性预测值高于对照组,Ⅱ级患者准确度、敏感度、阴性预测值高于对照组,Ⅲ级患者准确度、特异度、阳性预测值高于对照组,差异有统计学意义(P<0.05)。结论:MRI 3D CUBE T_(2)序列检查踝关节外伤患者韧带损伤诊断效能高于常规MRI检查,可作为治疗效果评价及康复治疗的重要依据。
基金financially supported by the National Natural Science Foundation of China(Grants Nos.11790311,92165205,51902152,11874210,and 11774149)the National Key R&D Program of China(Grants No.2021YFA1400403)。
文摘By using scanning tunneling microscopy,we investigated the electronic evolution of T_(d)-WTe_(2) via in-situ surface alkali K atoms deposition.The T_(d)-WTe_(2) surface is electron doped upon K deposition,and as the K coverage increases,two gaps are sequentially opened near Fermi energy,which probably indicates that two phase transitions concomitantly occur during electron doping.The two gaps both show a dome-like dependence on the K coverage.While the bigger gap shows no prominent dependence on the magnetic field,the smaller one can be well suppressed and thus possibly corresponds to the superconducting transition.This work indicates that T_(d)-WTe_(2) exhibits rich quantum states closely related to the carrier concentration.
基金the National Natural Science Foundation of China(No.11974129 to X.-F.W.)“the Fundamental Research Funds for the Central Universities,Jilin University.”。
文摘Two-dimensional(2D)perovskites solar cells(PSCs)have attracted considerable attention owing to their excellent stability against humidity;however,some imperfectness of 2D perovskites,such as poor crystallinity,disordered orientation,and inferior charge transport still limit the power conversion efficiency(PCE)of 2D PSCs.In this work,2D Ti3C2Tx MXene nanosheets with high electrical conductivity and mobility were employed as a nanosized additive to prepare 2D Ruddlesden–Popper perovskite films.The PCE of solar cells was increased from 13.69(without additive)to 15.71%after incorporating the Ti_(3)C_(2)T_(x) nanosheets with an optimized concentration.This improved performance is attributed to the enhanced crystallinity,orientation,and passivated trap states in the 3D phase that result in accelerated charge transfer process in vertical direction.More importantly,the unencapsulated cells exhibited excellent stability under ambient conditions with 55±5%relative humidity.
基金the National Key Research and Development Program of China(No.2022YFC2105900)the National Natural Science Foundation of China(No.52073022).
文摘The actual manufacture of supercapacitors(SCs)is restricted by the inadequate energy density,and the energy density of devices can be properly promoted by assembling zinc-ion capacitors(ZICs)which used capacitive cathode and battery-type anode.Two-dimensional(2D)MXene has brought great focuses in the electrode research on the foundation of large redox-active surface,but the specific capacitance is still affected by the tight stacking of interlaminations.Ti_(3)C_(2)T_(x)@polyaniline(PANI)heterostructures are prepared by uniformly depositing the conductive polymer PANI nanorods as the intercalation agent into the external of Ti_(3)C_(2)T_(x)nanosheets to inhibit stacking.Subsequently,by using graphene oxide(GO)-assisted low-temperature hydrothermal self-assembly manufacture,2D heterostructures are assembled into the three-dimensional(3D)porous crosslinked Ti_(3)C_(2)T_(x)@PANI-reduced graphene oxide(RGO)hydrogels.Attributed to the synergistic work of PANI nanorods,Ti_(3)C_(2)T_(X)nanosheets,and 3D crosslinking frameworks of RGO to match capacitive and battery effects,3D porous hierarchical Ti_(3)C_(2)T_(x)@PANI-RGO heterostructure hydrogels have rich ion transport channels,a large number of active sites,and excellent reaction kinetics.ZIC is assembled by using Ti_(3)C_(2)T_(x)@PANI-RGO heterostructure hydrogels as cathodes and zinc foil as anodes.In this work,Ti_(3)C_(2)T_(x)@PANI-RGO//Zn ZIC exhibits a wide working window(2.0 V),marked specific capacitance(589.89 F·g^(−1)at 0.5 A·g−1),salient energy density(327.71 Wh·kg^(−1)at 513.61 W·kg^(−1)and 192.20 Wh·kg^(−1)at 13,005.87 W·kg^(−1)),and durable cycling stability(97.87%capacitance retention after 10,000 cycles at 10 A·g^(−1)).This study emphasizes the device design of ZICs and the broad prospect of Ti_(3)C_(2)T_(x)-based hydrogels as viable cathodes for ZICs.
基金supported by the National Natural Science Foundation of China (Grant Nos.52225204, 11974074, and 11804048)the Innovation Program of Shanghai Municipal Education Commission (2021-01-07-00-03-E00109)+3 种基金the Fundamental Research Funds for the Central Universities (2232022G-07 and 2232021D-28)Graduate Student Innovation Fund of Donghua University (CUSF-DH-D-2022007)the Program Innovative Research Team in University (IRT_16R13)the International Joint Laboratory for Advanced fiber and Low- dimension Materials (18520750400).
文摘Catalysis has been regarded as an effective strategy to mitigate sluggish reaction kinetics and serious shuttle effect of Li-S batteries.Herein,a spherical structure consists of ultrathin layered Ti_(3)C_(2)T_(x)-TiN heterostructures(MX-TiN)through in-situ nitridation method is reported.Through controllable nitridation,highly conductive TiN layer grew on the surface and close coupled with interior MXene to form unique 2D heterostructures.The ultrathin heterostructure with only several nanometers in thickness enables outstanding ability to shorten electrons diffusion distance during electrochemical reactions and enlarge active surface with abundant adsorptive and catalytic sites.Moreover,the(001)surface of TiN is dominated by metallic Ti-3d states,which ensures fast transmitting electrons from high conductive MX-TiN matrix and thus guarantees efficient catalytic performance.Calculations and experiments demonstrate that polysulfides are strongly immobilized on MX-TiN,meanwhile the bidirectional reaction kinetics are catalytically enhanced by reducing the conversion barrier between liquid LiPSs and solid Li_(2)S_(2)/Li_(2)S.As a result,the S/MX-TiN cathode achieves excellent long-term cyclability with extremely low-capacity fading rate of 0.022%over 1000 cycles and remarkable areal capacity of 8.27 mAh cm^(−2) at high sulfur loading and lean electrolytes.
基金supported by the National Natural Science Foundation of China (51772069)。
文摘Lithium-sulfur(Li-S) batteries are one of the most promising rechargeable storage devices due to the high theoretical energy density.However,the low areal sulfur loading impedes their commercial development.Herein,a 3 D free-standing sulfur cathode scaffold is rationally designed and fabricated by coaxially coating polar Ti_3 C_2 T_x flakes on sulfur-impregnated carbon cloth(Ti_3 C_2 T_x@S/CC) to achieve high loading and high energy density Li-S batteries,in which,the flexible CC substrate with highly porous structure can accommodate large amounts of sulfur and ensure fast electron transfer,while the outer-coated Ti_3 C_2 T_x can serve as a polar and conductive protective layer to further promote the conductivity of the whole electrode,achieve physical blocking and chemical anchoring of lithium-polysulfides as well as catalyze their conversion.Due to these advantages,at a sulfur loading of 4 mg cm^(-2),Li-S cells with Ti_3 C_2 T_x@S/CC cathodes can deliver outstanding cycling stability(746.1 mAh g^(-1) after 200 cycles at1 C),superb rate performance(866.8 mAh g^(-1) up to 2 C) and a high specific energy density(564.2 Wh kg^(-1) after 100 cycles at 0.5 C).More significantly,they also show the commercial potential that can compete with current lithium-ion batteries due to the high areal capacity of 6.7 mAh cm^(-2) at the increased loading of 8 mg cm^(-2).
基金H.P.W.from Tsinghua University contributed to the theoretical calculation.All the authors discussed and participated into the paper writing.The authors are grateful for the financial support from the National Natural Science Foundation of China(Nos.62104017 and 62074015)the project funded by China Postdoctoral Science Foundation under Grant 2022M720422Beijing Institute of Technology Research Fund Program for Young Scholars.
文摘Two-/three-dimensional(2D/3D)heterojunction-based photodetectors have attracted much attention due to their highly efficient photoelectric conversion driven by the built-in electric field for high-speed photoresponse.However,a large dark current induced by unexpected surface states at the interface between 2D materials and 3D bulks is widely observed in such structures,greatly degrading their optoelectronic performance.Herein,a heterojunction of proton acid HCl treated MXene(H-MXene)/TiO_(2)/Si via integrating surface and interface engineering is fabricated,which exhibits decreased dark current and improved environmental stability.A feasible strategy to optimize the interface properties between MXene and Si is proposed by an in-situ oxidation process of MXene into TiO_(2),resulting in a suppressed dark current as well as high specific detectivity.Benefitting from the enhanced light absorption of MXene on the bulk Si substrate,the photoresponse of as-fabricated devices in the near-infrared region is also elevated.Moreover,the treatment of proton acid HCl on the surface of MXene brings better conductivity and environmental stability due to the decreased layer spacing of MXene,which is further confirmed by both experimental and theoretical methods.This work opens a unique way to comprehensively boost the optoelectronic performance of MXene-based photodetectors.
基金financial support from the National Natural Science Foundation of China (Nos. 51773169 and 51973173)Technical Basis Scientific Research Project (Highly Thermally Conductive Non-metal Materials)+2 种基金Guangdong Basic and Applied Basic Research Foundation (No. 2019B1515120093)Natural Science Basic Research Plan for Distinguished Young Scholars in Shaanxi Province of China (No. 2019JC-11)financially supported by Polymer Electromagnetic Functional Materials Innovation Team of Shaanxi Sanqin Scholars。
文摘This work proposes a facile fabrication strategy for thermally conductive graphite nanosheets/poly(lactic acid) sheets with ordered GNPs(o-GNPs/PLA) via fused deposition modeling(FDM) 3 D printing technology.Further combinations of o-GNPs/PLA with Ti_(3) C_(2) T_(x) films prepared by vacuum-assisted filtration were carried out by "layer-by-layer stacking-hot pressing" to be the thermally conductive Ti_(3) C_(2) T_(x)/(oGNPs/PLA) composites with superior electromagnetic interference shielding effectiveness(EMI SE).When the content of GNPs was 18.60 wt%and 4 layers of Ti_(3) C_(2) T_(x)(6.98 wt%) films were embedded,the in-plane thermal conductivity coefficient(λ_(Ⅱ)) and EMI SE(EMI SE_(Ⅱ)) values of the thermally conductive Ti_(3) C_(2) T_(x)/(o-GNPs/P LA) composites significantly increa sed to 3.44 W·m^(-1)·K^(-1) and 65 d B(3.00 mm),increased by 1223.1% and2066.7%,respectively,compared with λ_(Ⅱ)(0.26 W·m^(-1)·K^(-1)) and EMI SE_(Ⅱ)(3 d B) of neat PLA matrix.This work offers a novel and easily route for designing and manufacturing highly thermally conductive polymer composites with superior EMI SE for broader application.
