The stable sub-angstrom resolution of the aberration-corrected scanning transmission electron microscope(ACSTEM)makes it an advanced and practical characterization technique for all materials.Owing to the prosperous a...The stable sub-angstrom resolution of the aberration-corrected scanning transmission electron microscope(ACSTEM)makes it an advanced and practical characterization technique for all materials.Owing to the prosperous advancement in computational technology,specialized software and programs have emerged as potent facilitators across the entirety of electron microscopy characterization process.Utilizing advanced image processing algorithms promotes the rectification of image distortions,concurrently elevating the overall image quality to superior standards.Extracting high-resolution,pixel-level discrete information and converting it into atomic-scale,followed by performing statistical calculations on the physical matters of interest through quantitative analysis,represent an effective strategy to maximize the value of electron microscope images.The efficacious utilization of quantitative analysis of electron microscope images has become a progressively prominent consideration for materials scientists and electron microscopy researchers.This article offers a concise overview of the pivotal procedures in quantitative analysis and summarizes the computational methodologies involved from three perspectives:contrast,lattice and strain,as well as atomic displacements and polarization.It further elaborates on practical applications of these methods in electronic functional materials,notably in piezoelectrics/ferroelectrics and thermoelectrics.It emphasizes the indispensable role of quantitative analysis in fundamental theoretical research,elucidating the structure–property correlations in high-performance systems,and guiding synthesis strategies.展开更多
In the past decade,perovskite solar cells have become a promising candidate in the photovoltaic industry owing to their high power conversion efficiency that surpasses 25%.However,there are certain limitations that ha...In the past decade,perovskite solar cells have become a promising candidate in the photovoltaic industry owing to their high power conversion efficiency that surpasses 25%.However,there are certain limitations that have hindered the development and full-scale practical application of these cells,including the high cost and degradation of perovskite caused by the dopants.Hence,there is an urgent need to develop dopant-free hole transport materials(HTMs).In recent years,HTMs based on triphenylamine(TPA-HTMs)are receiving growing interest owing to their high hole mobility,excellent film formation,and suitable energy levels.The literature here covers work relevant to TPA-HTMs in the last five years.They have been classified according to different core types.The correlations between performance and structure are summarized,and the future development trend of TPA-HTMs is highlighted.展开更多
Large-size electronic-grade polycrystalline silicon is an important material in the semiconductor industry with broad application prospects.However,electronic-grade polycrystalline silicon has extremely high requireme...Large-size electronic-grade polycrystalline silicon is an important material in the semiconductor industry with broad application prospects.However,electronic-grade polycrystalline silicon has extremely high requirements for production technology and currently faces challenges such as carbon impurity breakdown,microstructure and composition nonuniformity and a lack of methods for preparing large-size mirror-like polycrystalline silicon samples.This paper innovatively uses physical methods such as wire cutting,mechanical grinding and ion thinning polishing to prepare large-size polycrystalline silicon samples that are clean,smooth,free from wear and have clear crystal defects.The material was characterized at both macroscopic and microscopic levels using metallographic microscopy,scanning electron microscopy(SEM)with backscattered electron diffraction(EBSD)techniques and scanning transmission electron microscopy(STEM).The crystal structure changes from single crystal silicon core to the surface of the bulk in the large-size polycrystalline silicon samples were revealed,providing a technical basis for optimizing and improving production processes.展开更多
This paper focuses on the problems encountered in the production process of electronic-grade polycrystalline silicon.It points out that the characterization of electronic-grade polycrystalline silicon is mainly concen...This paper focuses on the problems encountered in the production process of electronic-grade polycrystalline silicon.It points out that the characterization of electronic-grade polycrystalline silicon is mainly concentrated at the macroscopic scale,with relatively less research at the mesoscopic and microscopic scales.Therefore,we utilize the method of physical polishing to obtain polysilicon characterization samples and then the paper utilizes metallographic microscopy,scanning electron microscopy-electron backscatter diffraction technology,and aberration-corrected transmission electron microscopy technology to observe and characterize the interface region between silicon core and matrix in the deposition process of electronic-grade polycrystalline silicon,providing a full-scale characterization of the interface morphology,grain structure,and orientation distribution from macro to micro.Finally,the paper illustrates the current uncertainties regarding polycrystalline silicon.展开更多
Large metro transfer stations have been widely constructed in China,among which the double-island station faces the serious fire safety issues owing to its large passenger flow.In this paper,simulation cases were carr...Large metro transfer stations have been widely constructed in China,among which the double-island station faces the serious fire safety issues owing to its large passenger flow.In this paper,simulation cases were carried out to investigate the effectiveness of different ventilation modes by jointly operating tunnel ventilation fan(TVF)and platform screen doors(PSD)under two typical fire scenarios in the platform.The numerical model was established by Fire Dynamics Simulator software and verified via reduced-scale model experiments.The results indicate that the TVF mode of supplying at the end near fire and exhausting at the other end is superior to that of exhausting at both ends.Besides,activating more PSD and TVF on the both sides of platform will restrict smoke in one end to the greater extent.During a fire in the middle of the platform,opening all PSD near tunnel-2 and TVF in tunnel-2 and tunnel-3 is the most appropriate mode.While during a fire at the left end of the platform,activating all PSD and TVF on both sides is the optimal operation mode.The conclusions can provide guidance for smoke control design and on-site emergency ventilation operation in double-island platform fire.展开更多
The treatment of diabetic chronic wounds remains a global challenge due to the up-regulated inflammation response,oxidant stress,and persistent infection during healing process.Developing wound dressing materials with...The treatment of diabetic chronic wounds remains a global challenge due to the up-regulated inflammation response,oxidant stress,and persistent infection during healing process.Developing wound dressing materials with ideal biocompatibility,adequate mechanical strength,considerable under-water adhesion,sufficient anti-inflammation,antioxidant,and antibacterial properties is on-demand for clinical applications.In this study,we developed a bioactive skin-mimicking hydrogel band-aid through the combination of tannic acid(TA)and imidazolidinyl urea reinforced polyurethane(PMI)(TAP hydrogel)and explored its potentials in various medical applications,including hemostasis,normal skin incision,full-thickness skin wounds,and bacterial-infection skin incision on diabetic mice.TA was loaded into PMI hydrogel network to enhance the mechanical properties of TAP hydrogels through multiple non-covalent interactions(break strength:0.28-0.64 MPa;elongation at break:650-930%),which could resist the local stress and maintain the structural integrity of wound dressings during applications.Moreover,owing to the promising moisture-resistant adhesiveness and organ hemostasis,outstanding anti-inflammation,antibacterial,and antioxidant properties,TAP hydrogels could efficiently promote the recovery of skin incision and defects on diabetic mice.To further simulate the practical situation and explore the potential in clinical application,we also verified the treatment efficiency of TAP hydrogel in S.aureus-infected skin incision model on diabetic mice.展开更多
Mammalian bone is constantly metabolized from the embryonic stage,and the maintenance of bone health depends on the dynamic balance between bone resorption and bone formation,mediated by osteoclasts and osteoblasts.It...Mammalian bone is constantly metabolized from the embryonic stage,and the maintenance of bone health depends on the dynamic balance between bone resorption and bone formation,mediated by osteoclasts and osteoblasts.It is widely recognized that circadian clock genes can regulate bone metabolism.In recent years,the regulation of bone metabolism by non-coding RNAs has become a hotspot of research.MicroRNAs can participate in bone catabolism and anabolism by targeting key factors related to bone metabolism,including circadian clock genes.However,research in this field has been conducted only in recent years and the mechanisms involved are not yet well established.Recent studies have focused on how to target circadian clock genes to treat some diseases,such as autoimmune diseases,but few have focused on the co-regulation of circadian clock genes and microRNAs in bone metabolic diseases.Therefore,in this paper we review the progress of research on the co-regulation of bone metabolism by circadian clock genes and microRNAs,aiming to provide new ideas for the prevention and treatment of bone metabolic diseases such as osteoporosis.展开更多
Development of biocompatible hydrogel adhesives with robust tissue adhesion to realize instant hemorrhage control and injury sealing,especially for emergency rescue and tissue repair,is still challenging.Herein,we rep...Development of biocompatible hydrogel adhesives with robust tissue adhesion to realize instant hemorrhage control and injury sealing,especially for emergency rescue and tissue repair,is still challenging.Herein,we report a potent hydrogel adhesive by free radical polymerization of N-acryloyl aspartic acid(AASP)in a facile and straightforward way.Through delicate adjustment of steric hindrance,the synergistic effect between interface interactions and cohesion energy can be achieved in PAASP hydrogel verified by X-ray photoelectron spectroscopy(XPS)analysis and simulation calculation compared to poly(N-acryloyl glutamic acid)(PAGLU)and poly(N-acryloyl amidomalonic acid)(PAAMI)hydrogels.The adhesion strength of the PAASP hydrogel could reach 120 kPa to firmly seal the broken organs to withstand the external force with persistent stability under physiological conditions,and rapid hemostasis in different hemorrhage models on mice is achieved using PAASP hydrogel as physical barrier.Furthermore,the paper-based Fe^(3+)transfer printing method is applied to construct PAASP-based Janus hydrogel patch with both adhesive and non-adhesive surfaces,by which simultaneous wound healing and postoperative anti-adhesion can be realized in gastric perforation model on mice.This advanced hydrogel may show vast potential as bio-adhesives for emergency rescue and tissue/organ repair.展开更多
In recent years,two-dimensional metal halide perovskites(MHPs)have attracted increased attention for radiation detection and imaging.Their detection efficiencies are almost comparable to three-dimensional(3D)perovskit...In recent years,two-dimensional metal halide perovskites(MHPs)have attracted increased attention for radiation detection and imaging.Their detection efficiencies are almost comparable to three-dimensional(3D)perovskites.Meanwhile,they demonstrate superior stability to 3D perovskites.The pursuit of high-quality,phase-pure and lead-free two-dimensional MHP materials and large-area fabrication capability for x-ray detectors are among the research hotspots.In this review,we first give a brief introduction of the crystallographic structure,optoelectronic characteristics and preparation methods of high-quality two-dimensional perovskites.In addition,we overview the general working principles of direct and indirect x-ray detection processes and the corresponding performance metrics from the perspective of detection and imaging.Furthermore,we provide a comprehensive discussion on the recent advances in 2D perovskite x-ray detectors and imaging devices.Finally,we pinpoint several major obstacles of 2D x-ray detectors that should be overcome in the near future.展开更多
基金Project supported by the financial support from the National Key R&D Program of China(Grant No.2021YFB3201100)the National Natural Science Foundation of China(Grant No.52172128)the Top Young Talents Programme of Xi’an Jiaotong University.
文摘The stable sub-angstrom resolution of the aberration-corrected scanning transmission electron microscope(ACSTEM)makes it an advanced and practical characterization technique for all materials.Owing to the prosperous advancement in computational technology,specialized software and programs have emerged as potent facilitators across the entirety of electron microscopy characterization process.Utilizing advanced image processing algorithms promotes the rectification of image distortions,concurrently elevating the overall image quality to superior standards.Extracting high-resolution,pixel-level discrete information and converting it into atomic-scale,followed by performing statistical calculations on the physical matters of interest through quantitative analysis,represent an effective strategy to maximize the value of electron microscope images.The efficacious utilization of quantitative analysis of electron microscope images has become a progressively prominent consideration for materials scientists and electron microscopy researchers.This article offers a concise overview of the pivotal procedures in quantitative analysis and summarizes the computational methodologies involved from three perspectives:contrast,lattice and strain,as well as atomic displacements and polarization.It further elaborates on practical applications of these methods in electronic functional materials,notably in piezoelectrics/ferroelectrics and thermoelectrics.It emphasizes the indispensable role of quantitative analysis in fundamental theoretical research,elucidating the structure–property correlations in high-performance systems,and guiding synthesis strategies.
基金supported by the Fundamental Research Funds for the Central Universitiesthe National Key Research and Development Program of China(2020YFB0408002)。
文摘In the past decade,perovskite solar cells have become a promising candidate in the photovoltaic industry owing to their high power conversion efficiency that surpasses 25%.However,there are certain limitations that have hindered the development and full-scale practical application of these cells,including the high cost and degradation of perovskite caused by the dopants.Hence,there is an urgent need to develop dopant-free hole transport materials(HTMs).In recent years,HTMs based on triphenylamine(TPA-HTMs)are receiving growing interest owing to their high hole mobility,excellent film formation,and suitable energy levels.The literature here covers work relevant to TPA-HTMs in the last five years.They have been classified according to different core types.The correlations between performance and structure are summarized,and the future development trend of TPA-HTMs is highlighted.
基金financially supported by the National Natural Science Foundation of China(52322309 and 52173139)the"Young Talent Support Plan"of Xi’an Jiaotong Universitythe Fundamental Research Funds for the Central Universities(xzy022022015 and xzy022023018)。
基金support from the unveiling project by Qinghai Xince Technology Co.,Ltd.,Huanghe Hydropower Development Co.,Ltd.,Project No.XCKJ-FY(2024)No.1(total No.25).
文摘Large-size electronic-grade polycrystalline silicon is an important material in the semiconductor industry with broad application prospects.However,electronic-grade polycrystalline silicon has extremely high requirements for production technology and currently faces challenges such as carbon impurity breakdown,microstructure and composition nonuniformity and a lack of methods for preparing large-size mirror-like polycrystalline silicon samples.This paper innovatively uses physical methods such as wire cutting,mechanical grinding and ion thinning polishing to prepare large-size polycrystalline silicon samples that are clean,smooth,free from wear and have clear crystal defects.The material was characterized at both macroscopic and microscopic levels using metallographic microscopy,scanning electron microscopy(SEM)with backscattered electron diffraction(EBSD)techniques and scanning transmission electron microscopy(STEM).The crystal structure changes from single crystal silicon core to the surface of the bulk in the large-size polycrystalline silicon samples were revealed,providing a technical basis for optimizing and improving production processes.
基金support of the unveiling project of“Application Research on Carbon and Other Trace Impurities and Microstructure Characterization Technology on the Surface of Electronic Grade Polysilicon”by Qinghai Xince Technology Co.,Ltd.of the Huanghe Hydropower Development Co.,Ltd.,project number:XCKJ-FY(2024)No.1(total No.25).
文摘This paper focuses on the problems encountered in the production process of electronic-grade polycrystalline silicon.It points out that the characterization of electronic-grade polycrystalline silicon is mainly concentrated at the macroscopic scale,with relatively less research at the mesoscopic and microscopic scales.Therefore,we utilize the method of physical polishing to obtain polysilicon characterization samples and then the paper utilizes metallographic microscopy,scanning electron microscopy-electron backscatter diffraction technology,and aberration-corrected transmission electron microscopy technology to observe and characterize the interface region between silicon core and matrix in the deposition process of electronic-grade polycrystalline silicon,providing a full-scale characterization of the interface morphology,grain structure,and orientation distribution from macro to micro.Finally,the paper illustrates the current uncertainties regarding polycrystalline silicon.
基金supported by the National Natural Science Foundation of China(51674152,71790613,51906123)the National Outstanding Youth Science Foundation(51425404).
文摘Large metro transfer stations have been widely constructed in China,among which the double-island station faces the serious fire safety issues owing to its large passenger flow.In this paper,simulation cases were carried out to investigate the effectiveness of different ventilation modes by jointly operating tunnel ventilation fan(TVF)and platform screen doors(PSD)under two typical fire scenarios in the platform.The numerical model was established by Fire Dynamics Simulator software and verified via reduced-scale model experiments.The results indicate that the TVF mode of supplying at the end near fire and exhausting at the other end is superior to that of exhausting at both ends.Besides,activating more PSD and TVF on the both sides of platform will restrict smoke in one end to the greater extent.During a fire in the middle of the platform,opening all PSD near tunnel-2 and TVF in tunnel-2 and tunnel-3 is the most appropriate mode.While during a fire at the left end of the platform,activating all PSD and TVF on both sides is the optimal operation mode.The conclusions can provide guidance for smoke control design and on-site emergency ventilation operation in double-island platform fire.
基金the following foundation:National Natural Science Foundation of China(NSFC 51803165)Natural Science Basic Research Plan in Shaanxi Province of China(2019JQ-167)+2 种基金Fundamental Research Funds for the Central Universities(xjj2018050 and xzy022019070)“Young Talent Support Plan”of Xi’an Jiaotong Universitythe Opening Project of Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research,College of Stomatology,Xi’an Jiaotong University(2019LHM-KFKT007)。
文摘The treatment of diabetic chronic wounds remains a global challenge due to the up-regulated inflammation response,oxidant stress,and persistent infection during healing process.Developing wound dressing materials with ideal biocompatibility,adequate mechanical strength,considerable under-water adhesion,sufficient anti-inflammation,antioxidant,and antibacterial properties is on-demand for clinical applications.In this study,we developed a bioactive skin-mimicking hydrogel band-aid through the combination of tannic acid(TA)and imidazolidinyl urea reinforced polyurethane(PMI)(TAP hydrogel)and explored its potentials in various medical applications,including hemostasis,normal skin incision,full-thickness skin wounds,and bacterial-infection skin incision on diabetic mice.TA was loaded into PMI hydrogel network to enhance the mechanical properties of TAP hydrogels through multiple non-covalent interactions(break strength:0.28-0.64 MPa;elongation at break:650-930%),which could resist the local stress and maintain the structural integrity of wound dressings during applications.Moreover,owing to the promising moisture-resistant adhesiveness and organ hemostasis,outstanding anti-inflammation,antibacterial,and antioxidant properties,TAP hydrogels could efficiently promote the recovery of skin incision and defects on diabetic mice.To further simulate the practical situation and explore the potential in clinical application,we also verified the treatment efficiency of TAP hydrogel in S.aureus-infected skin incision model on diabetic mice.
基金This work was supported by the National Natural Science Foundation of China(Nos.81901430 and 81871835)the Guangdong Provincial Natural Science Foundation of China(No.2022A1515010379)+1 种基金the Innovation Project from Department of Education of Guangdong Province(No.2021KTSCX 055)the Shanghai Frontiers Science Research Base of Exercise and Metabolic Health,and the Shanghai Key Laboratory for Human Athletic Ability Development and Support(Shanghai University of Sport)(No.11DZ2261100),China.
文摘Mammalian bone is constantly metabolized from the embryonic stage,and the maintenance of bone health depends on the dynamic balance between bone resorption and bone formation,mediated by osteoclasts and osteoblasts.It is widely recognized that circadian clock genes can regulate bone metabolism.In recent years,the regulation of bone metabolism by non-coding RNAs has become a hotspot of research.MicroRNAs can participate in bone catabolism and anabolism by targeting key factors related to bone metabolism,including circadian clock genes.However,research in this field has been conducted only in recent years and the mechanisms involved are not yet well established.Recent studies have focused on how to target circadian clock genes to treat some diseases,such as autoimmune diseases,but few have focused on the co-regulation of circadian clock genes and microRNAs in bone metabolic diseases.Therefore,in this paper we review the progress of research on the co-regulation of bone metabolism by circadian clock genes and microRNAs,aiming to provide new ideas for the prevention and treatment of bone metabolic diseases such as osteoporosis.
基金the National Natural Science Foundation of China(NSFC 52173139)the Shaanxi International Science and Technology Cooperation Program Project(2020KW-062)+1 种基金the“Young Talent Support Plan”of Xi’an Jiaotong University,and Fundamental Research Funds for the Central Universities(xzy022021040)supported by the Opening Research Fund from Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research,College of Stomatology,Xi’an Jiaotong University(2021LHM-KFKT003).
文摘Development of biocompatible hydrogel adhesives with robust tissue adhesion to realize instant hemorrhage control and injury sealing,especially for emergency rescue and tissue repair,is still challenging.Herein,we report a potent hydrogel adhesive by free radical polymerization of N-acryloyl aspartic acid(AASP)in a facile and straightforward way.Through delicate adjustment of steric hindrance,the synergistic effect between interface interactions and cohesion energy can be achieved in PAASP hydrogel verified by X-ray photoelectron spectroscopy(XPS)analysis and simulation calculation compared to poly(N-acryloyl glutamic acid)(PAGLU)and poly(N-acryloyl amidomalonic acid)(PAAMI)hydrogels.The adhesion strength of the PAASP hydrogel could reach 120 kPa to firmly seal the broken organs to withstand the external force with persistent stability under physiological conditions,and rapid hemostasis in different hemorrhage models on mice is achieved using PAASP hydrogel as physical barrier.Furthermore,the paper-based Fe^(3+)transfer printing method is applied to construct PAASP-based Janus hydrogel patch with both adhesive and non-adhesive surfaces,by which simultaneous wound healing and postoperative anti-adhesion can be realized in gastric perforation model on mice.This advanced hydrogel may show vast potential as bio-adhesives for emergency rescue and tissue/organ repair.
基金supported by the National Natural Science Foundation of China(22279083)Natural Science Foundation of Guangdong Province(2019A1515010783)+1 种基金Guangzhou Science and Technology Planning Project(202102010443)Songshan Lake Materials Laboratory.
文摘In recent years,two-dimensional metal halide perovskites(MHPs)have attracted increased attention for radiation detection and imaging.Their detection efficiencies are almost comparable to three-dimensional(3D)perovskites.Meanwhile,they demonstrate superior stability to 3D perovskites.The pursuit of high-quality,phase-pure and lead-free two-dimensional MHP materials and large-area fabrication capability for x-ray detectors are among the research hotspots.In this review,we first give a brief introduction of the crystallographic structure,optoelectronic characteristics and preparation methods of high-quality two-dimensional perovskites.In addition,we overview the general working principles of direct and indirect x-ray detection processes and the corresponding performance metrics from the perspective of detection and imaging.Furthermore,we provide a comprehensive discussion on the recent advances in 2D perovskite x-ray detectors and imaging devices.Finally,we pinpoint several major obstacles of 2D x-ray detectors that should be overcome in the near future.
