With the rapid development of portable electronics and electric road vehicles,high-energy-density batteries have been becoming front-burner issues.Traditionally,homogeneous electrolyte cannot simultaneously meet diame...With the rapid development of portable electronics and electric road vehicles,high-energy-density batteries have been becoming front-burner issues.Traditionally,homogeneous electrolyte cannot simultaneously meet diametrically opposed demands of high-potential cathode and low-potential anode,which are essential for high-voltage batteries.Meanwhile,homogeneous electrolyte is difficult to achieve bi-or multi-functions to meet different requirements of electrodes.In comparison,the asymmetric electrolyte with bi-or multi-layer disparate components can satisfy distinct requirements by playing different roles of each electrolyte layer and meanwhile compensates weakness of individual electrolyte.Consequently,the asymmetric electrolyte can not only suppress by-product sedimentation and continuous electrolyte decomposition at the anode while preserving active substances at the cathode for high-voltage batteries with long cyclic lifespan.In this review,we comprehensively divide asymmetric electrolytes into three categories:decoupled liquid-state electrolytes,bi-phase solid/liquid electrolytes and decoupled asymmetric solid-state electrolytes.The design principles,reaction mechanism and mutual compatibility are also studied,respectively.Finally,we provide a comprehensive vision for the simplification of structure to reduce costs and increase device energy density,and the optimization of solvation structure at anolyte/catholyte interface to realize fast ion transport kinetics.展开更多
Perovskite solar cells(PSCs)have emerged as a promising photovoltaic technology because of their high light absorption coefficient,long carrier diffusion distance,and tunable bandgap.However,PSCs face challenges such ...Perovskite solar cells(PSCs)have emerged as a promising photovoltaic technology because of their high light absorption coefficient,long carrier diffusion distance,and tunable bandgap.However,PSCs face challenges such as hysteresis effects and stability issues.In this study,we introduced a novel approach to improve film crystallization by leveraging 4-tert-butylpyridine(TBP)molecules,thereby enhancing the performance and stability of PSCs.Our findings demonstrate the effective removal of PbI_(2)from the perovskite surface through strong coordination with TBP molecules.Additionally,by carefully adjusting the concentration of the TBP solution,we achieved enhanced film crystallinity without disrupting the perovskite structure.The TBP-treated perovskite films exhibit a low defect density,improved crystallinity,and improved carrier lifetime.As a result,the PSCs manufactured with TBP treatment achieve power conversion efficiency(PCE)exceeding 24%.Moreover,we obtained the PCE of 21.39%for the 12.25 cm^(2)module.展开更多
Optical reflection anisotropy microscopy mappings of micropipe defects on the surface of a 4H-SiC single crystal are studied by the scanning anisotropy microscopy(SAM)system.The reflection anisotropy(RA)image with a&#...Optical reflection anisotropy microscopy mappings of micropipe defects on the surface of a 4H-SiC single crystal are studied by the scanning anisotropy microscopy(SAM)system.The reflection anisotropy(RA)image with a'butterfly pattern'is obtained around the micropipes by SAM.The RA image of the edge dislocations is theoretically simulated based on dislocation theory and the photoelastic principle.By comparing with the Raman spectrum,it is verified that the micropipes consist of edge dislocations.The different patterns of the RA images are due to the different orientations of the Burgers vectors.Besides,the strain distribution of the micropipes is also deduced.One can identify the dislocation type,the direction of the Burgers vector and the optical anisotropy from the RA image by using SAM.Therefore,SAM is an ideal tool to measure the optical anisotropy induced by the strain field around a defect.展开更多
The successful synthesis of the pentazolate anion(cyclo-N-5)has been a great breakthrough in the field of energetic materials.However,the detection methods for these energetic materials based on the pentazolate anion ...The successful synthesis of the pentazolate anion(cyclo-N-5)has been a great breakthrough in the field of energetic materials.However,the detection methods for these energetic materials based on the pentazolate anion are quite rare.Herein,two fluorescent probes for cyclo-N-5anion were designed.Sensor 1(TPE2N)was synthesized with a tetraphenylethylene functionalized by two cationic groups which can generate strong electrostatic interactions with pentazolate anion and result in specific fluorescent changes.Sensor 2 was designed based on sensor 1 and supramolecular cucurbit[7]uril(CB[7]).The unique structural features of CB[7]provide sites for the interaction between the cations and N-5anion in its cavity,which would generate a platform for the detection and enhance the recognition performance.Isothermal titration calorimetry(ITC)experiment and fluorescence titration experiment indicate the binding molar ratio between sensor 1 with CB[7]is 1:2.Both sensors display typical aggregation-induced emission(AIE)features and good water-solubility.The sensors demonstrate excellent sensitivity to pentazole hydrazine salt with high enhancement constant(sensor 1:1.34×10^(6);sensor 2:3.78×10^(6))and low limit of detection(LOD:sensor 1=4.33μM;sensor 2=1.54μM).The formation of an AIE-based supramolecular sensor effectively improves the sensitivity to N-5anion.In addition,the probes also have good selectivity of N-5anion salts.The research would shed some light on the design of novel fluorescent sensors to detect pentazolate-based molecules and provides an example of supramolecular chemistry combined with fluorescent probes.展开更多
We present a formalism of charge self-consistent dynamical mean field theory(DMFT)in combination with densityfunctional theory(DFT)within the linear combination of numerical atomic orbitals(LCNAO)framework.We implemen...We present a formalism of charge self-consistent dynamical mean field theory(DMFT)in combination with densityfunctional theory(DFT)within the linear combination of numerical atomic orbitals(LCNAO)framework.We implementedthe charge self-consistent DFT+DMFT formalism by interfacing a full-potential all-electron DFT code with threehybridization expansion-based continuous-time quantum Monte Carlo impurity solvers.The benchmarks on several 3d,4fand 5f strongly correlated electron systems validated our formalism and implementation.Furthermore,within the LCANOframework,our formalism is general and the code architecture is extensible,so it can work as a bridge merging differentLCNAO DFT packages and impurity solvers to do charge self-consistent DFT+DMFT calculations.展开更多
Terahertz heterodyne receivers with high sensitivity and spectral resolution are crucial for various applications.Here,we present a room-temperature atomic terahertz heterodyne receiver that achieves ultrahigh sensiti...Terahertz heterodyne receivers with high sensitivity and spectral resolution are crucial for various applications.Here,we present a room-temperature atomic terahertz heterodyne receiver that achieves ultrahigh sensitivity and frequency resolution.At a signal frequency of 338.7 GHz,we obtain a sensitivity of 2.88±0.09V·cm^(−1)·Hz^(−1/2) for electric field measurements.The calibrated linear dynamical range spans approximately 89 dB,ranging from−110 dBV/cm to−21 dBV/cm.We demodulate a 400 symbol stream encoded in 4-state phase-shift keying,demonstrating excellent phase detection capability.By scanning the frequency of the local oscillator,we realize a terahertz spectrometer with Hz level frequency resolution.This resolution is more than two orders of magnitude higher than that of existing terahertz spectrometers.The demonstrated terahertz heterodyne receiver holds promising potential for working across the entire terahertz spectrum,significantly advancing its practical applications.展开更多
Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since ...Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since the mechanical exfoliation of graphene in 2004. Starting from graphene, 2D materials now have become a big family with numerous members and diverse categories. The unique structural features and physicochemical properties of 2D materials make them one class of the most appealing candidates for a wide range of potential applications. In particular, we have seen some major breakthroughs made in the field of 2D materials in last five years not only in developing novel synthetic methods and exploring new structures/properties but also in identifying innovative applications and pushing forward commercialisation. In this review, we provide a critical summary on the recent progress made in the field of 2D materials with a particular focus on last five years. After a brief backgroundintroduction, we first discuss the major synthetic methods for 2D materials, including the mechanical exfoliation, liquid exfoliation, vapor phase deposition, and wet-chemical synthesis as well as phase engineering of 2D materials belonging to the field of phase engineering of nanomaterials(PEN). We then introduce the superconducting/optical/magnetic properties and chirality of 2D materials along with newly emerging magic angle 2D superlattices. Following that, the promising applications of 2D materials in electronics, optoelectronics, catalysis, energy storage, solar cells, biomedicine, sensors, environments, etc. are described sequentially. Thereafter, we present the theoretic calculations and simulations of 2D materials. Finally, after concluding the current progress, we provide some personal discussions on the existing challenges and future outlooks in this rapidly developing field.展开更多
Background:Postoperative care has been evolving since the concept of enhanced recovery after surgery(ERAS)was introduced in China.This study aimed to evaluate the effects of early ambulation within 24h after unilatera...Background:Postoperative care has been evolving since the concept of enhanced recovery after surgery(ERAS)was introduced in China.This study aimed to evaluate the effects of early ambulation within 24h after unilateral total knee arthroplasty(TKA)on postoperative rehabilitation and costs in a Chinese population.Methods:This cohort study of patients with knee osteoarthritis who had undergone TKA at 24 large teaching hospitals between January 2014 and November 2016 involved 2687 patients who began ambulating within 24h(Group A)and 3761 patients who began ambulating later than 24h(Group B).The outcome measurements,such as length of stay(LOS),total hospitalization costs,dynamic pain level,knee flexion range of motion(ROM),results of the 12-Item Short Form Survey(SF-12),incidence of thromboembolic events and other complications,were recorded and compared.Results:The early ambulation group(Group A)had a shorter LOS and lower hospitalization costs and pain levels than the late ambulation group(Group B).There was a favorable effect in enhancing ROM for patients in Group A compared with patients in Group B.In Group A,patients had significantly higher postoperative SF-12 scores than those in Group B.The incidence of deep venous thrombosis(DVT)and pulmonary infection was significantly lower in Group A than in Group B.The incidence of pulmonary embolism(PE)and other complications did not differ between the two groups.Conclusions:Early ambulation within 24h after TKA was associated with reduced LOS,improved knee function,lower hospitalization costs and lower incidence of DVT and pulmonary infection in the Chinese population.展开更多
Lithium sulfur batteries(LSBs)are recognized as promising devices for developing next-generation energy storage systems.In addition,they are attractive rechargeable battery systems for replacing lithium-ion batteries(...Lithium sulfur batteries(LSBs)are recognized as promising devices for developing next-generation energy storage systems.In addition,they are attractive rechargeable battery systems for replacing lithium-ion batteries(LIBs)for commercial use owing to their higher theoretical energy density and lower cost compared to those of LIBs.However,LSBs are still beset with some persistent issues that prevent them from being used industrially,such as the unavoidable dissolution of lithium polysulfide intermediates during electrochemical reactions and large volume expansion(up to 80%)upon the formation of Li_(2)S,resulting in serious battery life and safety limitations.In the process of solving these problems,it is necessary to maintain a high sulfur content in the cathode materials to ensure that the LSBs have high energy densities and excellent cycle performance.In this review,the novel preparation methods and cathode materials used for preparing LSBs in recent years are reviewed considering the sulfur content and cycle performance.In addition,the problems and difficulties in practically applying cathode materials are described,and the development trend is discussed.展开更多
基金National Natural Science Foundation of China(52202299)the Analytical&Testing Center of Northwestern Polytechnical University(2022T006).
文摘With the rapid development of portable electronics and electric road vehicles,high-energy-density batteries have been becoming front-burner issues.Traditionally,homogeneous electrolyte cannot simultaneously meet diametrically opposed demands of high-potential cathode and low-potential anode,which are essential for high-voltage batteries.Meanwhile,homogeneous electrolyte is difficult to achieve bi-or multi-functions to meet different requirements of electrodes.In comparison,the asymmetric electrolyte with bi-or multi-layer disparate components can satisfy distinct requirements by playing different roles of each electrolyte layer and meanwhile compensates weakness of individual electrolyte.Consequently,the asymmetric electrolyte can not only suppress by-product sedimentation and continuous electrolyte decomposition at the anode while preserving active substances at the cathode for high-voltage batteries with long cyclic lifespan.In this review,we comprehensively divide asymmetric electrolytes into three categories:decoupled liquid-state electrolytes,bi-phase solid/liquid electrolytes and decoupled asymmetric solid-state electrolytes.The design principles,reaction mechanism and mutual compatibility are also studied,respectively.Finally,we provide a comprehensive vision for the simplification of structure to reduce costs and increase device energy density,and the optimization of solvation structure at anolyte/catholyte interface to realize fast ion transport kinetics.
基金financial support from various entities,including the Foundation of Anhui Science and Technology University[HCYJ202201]the Anhui Science and Technology University’s Student Innovation and Entrepreneurship Training Program[S202310879115,202310879053]+4 种基金the Key Project of Natural Science Research in Anhui Science and Technology University[2021ZRZD07]the Chuzhou Science and Technology Project[2021GJ002]the Anhui Province Key Research and Development Program[202304a05020085]the Natural Science Research Project of Anhui Educational Committee[2023AH051877]The Opening Project of State Key Laboratory of Advanced Technology for Float Glass[2020KF06,2022KF06]。
文摘Perovskite solar cells(PSCs)have emerged as a promising photovoltaic technology because of their high light absorption coefficient,long carrier diffusion distance,and tunable bandgap.However,PSCs face challenges such as hysteresis effects and stability issues.In this study,we introduced a novel approach to improve film crystallization by leveraging 4-tert-butylpyridine(TBP)molecules,thereby enhancing the performance and stability of PSCs.Our findings demonstrate the effective removal of PbI_(2)from the perovskite surface through strong coordination with TBP molecules.Additionally,by carefully adjusting the concentration of the TBP solution,we achieved enhanced film crystallinity without disrupting the perovskite structure.The TBP-treated perovskite films exhibit a low defect density,improved crystallinity,and improved carrier lifetime.As a result,the PSCs manufactured with TBP treatment achieve power conversion efficiency(PCE)exceeding 24%.Moreover,we obtained the PCE of 21.39%for the 12.25 cm^(2)module.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2018YFE0204001,2018YFA0209103,2016YFB0400101,and 2016YFB0402303)the National Natural Science Foundation of China(Grant Nos.61627822,61704121,61991430,and 62074036)Postdoctoral Research Program of Jiangsu Province(Grant No.2021K599C).
文摘Optical reflection anisotropy microscopy mappings of micropipe defects on the surface of a 4H-SiC single crystal are studied by the scanning anisotropy microscopy(SAM)system.The reflection anisotropy(RA)image with a'butterfly pattern'is obtained around the micropipes by SAM.The RA image of the edge dislocations is theoretically simulated based on dislocation theory and the photoelastic principle.By comparing with the Raman spectrum,it is verified that the micropipes consist of edge dislocations.The different patterns of the RA images are due to the different orientations of the Burgers vectors.Besides,the strain distribution of the micropipes is also deduced.One can identify the dislocation type,the direction of the Burgers vector and the optical anisotropy from the RA image by using SAM.Therefore,SAM is an ideal tool to measure the optical anisotropy induced by the strain field around a defect.
基金supported by the National Natural Science Foundation of China(Grant Nos.22175093 and 22007047)the Natural Science Foundation of Jiangsu Province(Grant No.BK20200474)the China Postdoctoral Science Foundation(Grant No.2022M721615)。
文摘The successful synthesis of the pentazolate anion(cyclo-N-5)has been a great breakthrough in the field of energetic materials.However,the detection methods for these energetic materials based on the pentazolate anion are quite rare.Herein,two fluorescent probes for cyclo-N-5anion were designed.Sensor 1(TPE2N)was synthesized with a tetraphenylethylene functionalized by two cationic groups which can generate strong electrostatic interactions with pentazolate anion and result in specific fluorescent changes.Sensor 2 was designed based on sensor 1 and supramolecular cucurbit[7]uril(CB[7]).The unique structural features of CB[7]provide sites for the interaction between the cations and N-5anion in its cavity,which would generate a platform for the detection and enhance the recognition performance.Isothermal titration calorimetry(ITC)experiment and fluorescence titration experiment indicate the binding molar ratio between sensor 1 with CB[7]is 1:2.Both sensors display typical aggregation-induced emission(AIE)features and good water-solubility.The sensors demonstrate excellent sensitivity to pentazole hydrazine salt with high enhancement constant(sensor 1:1.34×10^(6);sensor 2:3.78×10^(6))and low limit of detection(LOD:sensor 1=4.33μM;sensor 2=1.54μM).The formation of an AIE-based supramolecular sensor effectively improves the sensitivity to N-5anion.In addition,the probes also have good selectivity of N-5anion salts.The research would shed some light on the design of novel fluorescent sensors to detect pentazolate-based molecules and provides an example of supramolecular chemistry combined with fluorescent probes.
文摘We present a formalism of charge self-consistent dynamical mean field theory(DMFT)in combination with densityfunctional theory(DFT)within the linear combination of numerical atomic orbitals(LCNAO)framework.We implementedthe charge self-consistent DFT+DMFT formalism by interfacing a full-potential all-electron DFT code with threehybridization expansion-based continuous-time quantum Monte Carlo impurity solvers.The benchmarks on several 3d,4fand 5f strongly correlated electron systems validated our formalism and implementation.Furthermore,within the LCANOframework,our formalism is general and the code architecture is extensible,so it can work as a bridge merging differentLCNAO DFT packages and impurity solvers to do charge self-consistent DFT+DMFT calculations.
基金supported by the National Key Research and Development Program of China(Grant No.2021YFA1402004)the Key-Area Research and Development Program of Guangdong Province,China(Grant Nos.2019B030330001 and 2020B0301030008)+2 种基金the National Natural Science Foundation of China(Grant Nos.12225405,12204182,and U20A2074)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301705)the Natural Science Foundation of Guangdong Province,China(Grant No.2022A1515012026).
文摘Terahertz heterodyne receivers with high sensitivity and spectral resolution are crucial for various applications.Here,we present a room-temperature atomic terahertz heterodyne receiver that achieves ultrahigh sensitivity and frequency resolution.At a signal frequency of 338.7 GHz,we obtain a sensitivity of 2.88±0.09V·cm^(−1)·Hz^(−1/2) for electric field measurements.The calibrated linear dynamical range spans approximately 89 dB,ranging from−110 dBV/cm to−21 dBV/cm.We demodulate a 400 symbol stream encoded in 4-state phase-shift keying,demonstrating excellent phase detection capability.By scanning the frequency of the local oscillator,we realize a terahertz spectrometer with Hz level frequency resolution.This resolution is more than two orders of magnitude higher than that of existing terahertz spectrometers.The demonstrated terahertz heterodyne receiver holds promising potential for working across the entire terahertz spectrum,significantly advancing its practical applications.
文摘Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since the mechanical exfoliation of graphene in 2004. Starting from graphene, 2D materials now have become a big family with numerous members and diverse categories. The unique structural features and physicochemical properties of 2D materials make them one class of the most appealing candidates for a wide range of potential applications. In particular, we have seen some major breakthroughs made in the field of 2D materials in last five years not only in developing novel synthetic methods and exploring new structures/properties but also in identifying innovative applications and pushing forward commercialisation. In this review, we provide a critical summary on the recent progress made in the field of 2D materials with a particular focus on last five years. After a brief backgroundintroduction, we first discuss the major synthetic methods for 2D materials, including the mechanical exfoliation, liquid exfoliation, vapor phase deposition, and wet-chemical synthesis as well as phase engineering of 2D materials belonging to the field of phase engineering of nanomaterials(PEN). We then introduce the superconducting/optical/magnetic properties and chirality of 2D materials along with newly emerging magic angle 2D superlattices. Following that, the promising applications of 2D materials in electronics, optoelectronics, catalysis, energy storage, solar cells, biomedicine, sensors, environments, etc. are described sequentially. Thereafter, we present the theoretic calculations and simulations of 2D materials. Finally, after concluding the current progress, we provide some personal discussions on the existing challenges and future outlooks in this rapidly developing field.
基金the National Health and Family Planning Commission of the People’s Republic of China(CN)program(201302007).
文摘Background:Postoperative care has been evolving since the concept of enhanced recovery after surgery(ERAS)was introduced in China.This study aimed to evaluate the effects of early ambulation within 24h after unilateral total knee arthroplasty(TKA)on postoperative rehabilitation and costs in a Chinese population.Methods:This cohort study of patients with knee osteoarthritis who had undergone TKA at 24 large teaching hospitals between January 2014 and November 2016 involved 2687 patients who began ambulating within 24h(Group A)and 3761 patients who began ambulating later than 24h(Group B).The outcome measurements,such as length of stay(LOS),total hospitalization costs,dynamic pain level,knee flexion range of motion(ROM),results of the 12-Item Short Form Survey(SF-12),incidence of thromboembolic events and other complications,were recorded and compared.Results:The early ambulation group(Group A)had a shorter LOS and lower hospitalization costs and pain levels than the late ambulation group(Group B).There was a favorable effect in enhancing ROM for patients in Group A compared with patients in Group B.In Group A,patients had significantly higher postoperative SF-12 scores than those in Group B.The incidence of deep venous thrombosis(DVT)and pulmonary infection was significantly lower in Group A than in Group B.The incidence of pulmonary embolism(PE)and other complications did not differ between the two groups.Conclusions:Early ambulation within 24h after TKA was associated with reduced LOS,improved knee function,lower hospitalization costs and lower incidence of DVT and pulmonary infection in the Chinese population.
基金the National Natural Science Foundation of China(52103093)the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(2021QNRC001)+2 种基金the Jiangxi Provincial Natural Science Foundation(20212BAB214048)Science and Technology Support Project of Shangrao(2020L009,2021J006)Science and Technological Project of Education Department of Jiangxi(GJJ211704)for funding their contributions to this paper。
文摘Lithium sulfur batteries(LSBs)are recognized as promising devices for developing next-generation energy storage systems.In addition,they are attractive rechargeable battery systems for replacing lithium-ion batteries(LIBs)for commercial use owing to their higher theoretical energy density and lower cost compared to those of LIBs.However,LSBs are still beset with some persistent issues that prevent them from being used industrially,such as the unavoidable dissolution of lithium polysulfide intermediates during electrochemical reactions and large volume expansion(up to 80%)upon the formation of Li_(2)S,resulting in serious battery life and safety limitations.In the process of solving these problems,it is necessary to maintain a high sulfur content in the cathode materials to ensure that the LSBs have high energy densities and excellent cycle performance.In this review,the novel preparation methods and cathode materials used for preparing LSBs in recent years are reviewed considering the sulfur content and cycle performance.In addition,the problems and difficulties in practically applying cathode materials are described,and the development trend is discussed.
