In this study,uniform diamond films with a diameter of 100 mm were deposited in a 15 kW/2.45 GHz ellipsoidal microwave plasma chemical vapour deposition system.A phenomenological model previously developed by our grou...In this study,uniform diamond films with a diameter of 100 mm were deposited in a 15 kW/2.45 GHz ellipsoidal microwave plasma chemical vapour deposition system.A phenomenological model previously developed by our group was used to simulate the distribution of the electric strength and electron density of plasma.Results indicate that the electric field in the cavity includes multiple modes,i.e.TM_(02) and TM_(03).When the gas pressure exceeds 10 kPa,the electron density of plasma increases and plasma volume decreases.A T-shaped substrate was developed to achieve uniform temperature,and the substrate was suspended in air fromφ70 to 100 mm,thus eliminating vertical heat dissipation.An edge electric field was added to the system after the introduction of the T-shaped substrate.Moreover,the plasma volume in this case was greater than that in the central electric field but smaller than that in the periphery electric field of the TM_(02) mode.This indicates that the electric field above and below the edge benefits the plasma volume rather than the periphery electric field of the TM_(02) mode.The quality,uniformity and surface morphology of the deposited diamond films were primarily investigated to maintain substrate temperature uniformity.When employing the improved substrate,the thickness unevenness of theφ100 mm diamond film decreased from 22%to 7%.展开更多
Current electronic technology based on silicon is approaching its physical and scientific limits. Carbon-based devices have numer- ous advantages for next generation electronics (e.g., fast speed, low power consumptio...Current electronic technology based on silicon is approaching its physical and scientific limits. Carbon-based devices have numer- ous advantages for next generation electronics (e.g., fast speed, low power consumption and simple process), that when combined with the unique nature of the versatile allotropes of carbon elements, are creating an electronics revolution. Carbon electronics are greatly advancing with new preparations and sophisticated designs. In this perspective, representatives with various dimensions, e.g., carbon nanotubes, graphene, bulk diamond, and their extraordinary performance, are reviewed. The associated state-of-the-art devices and composite hybrid all-carbon structures are also emphasized to reveal their potential in the electronics field. Advances in commercial production have improved the cost effi-ciency, material quality, and device design, accelerating the promise of carbon materials.展开更多
This study focused on the investigation of the edge effect of diamond films deposited by microwave plasma chemical vapor de-position.Substrate bulge height△h is a factor that affects the edge effect,and it was used t...This study focused on the investigation of the edge effect of diamond films deposited by microwave plasma chemical vapor de-position.Substrate bulge height△h is a factor that affects the edge effect,and it was used to simulate plasma and guide the diamond-film deposition experiments.Finite-element software COMSOL Multiphysics was used to construct a multiphysics(electromagnetic,plasma,and fluid heat transfer fields)coupling model based on electron collision reaction.Raman spectroscopy and scanning electron microscopy were performed to characterize the experimental growth and validate the model.The simulation results reflected the experimental trends observed.Plasma discharge at the edge of the substrate accelerated due to the increase in△h(△h=0-3 mm),and the values of electron density(n_(c)),molar concentration of H(C_(H)),and molar concentration of CH_(3)(C_(CH_(3)))doubled at the edge(for the special concave sample with△h=−1 mm,the active chemical groups exhibited a decreased molar concentration at the edge of the substrate).At=0-3 mm,a high diamond growth rate and a large diamond grain size were observed at the edge of the substrate,and their values increased with.The uniformity of film thickness decreased with.The Raman spectra of all samples revealed the first-order characteristic peak of dia-mond near 1332 cm^(−1).When△h=−1 mm,tensile stress occurred in all regions of the film.When△h=1-3 mm,all areas in the film ex-hibited compressive stress.展开更多
Periodic nitrogen-doped homoepitaxial nano-multilayers were grown by microwave plasma chemical vapor deposition. The residual time of gases(such as CH4and N2) in the chamber was determined by optical emission spectros...Periodic nitrogen-doped homoepitaxial nano-multilayers were grown by microwave plasma chemical vapor deposition. The residual time of gases(such as CH4and N2) in the chamber was determined by optical emission spectroscopy to determine the nano-multilayer growth process, and thin, nanoscale nitrogen-doped layers were obtained. The highest toughness of 18.2 MPa·m^(1/2)under a Young’s modulus of1000 GPa is obtained when the single-layer thickness of periodic nitrogen-doped nano-multilayers is about 96 nm. The fracture toughness of periodic nitrogen-doped CVD layer is about 2.1 times that of the HPHT seed substrate. Alternating tensile and compressive stresses are derived from periodic nitrogen doping;hence, the fracture toughness is significantly improved. Single-crystal diamond with a high toughness demonstrates wide application prospects for high-pressure anvils and single-point diamond cutting tools.展开更多
The use of porous skeletons for encapsulating phase change materials(PCMs)is an effective approach to addressing issues such as leakage,low thermal conductivity,and poor photothermal conversion efficiency.Inspired by ...The use of porous skeletons for encapsulating phase change materials(PCMs)is an effective approach to addressing issues such as leakage,low thermal conductivity,and poor photothermal conversion efficiency.Inspired by the hollow skeletal structure found in birds in nature,high-quality 3D interconnected hollow diamond foam(HDF)was fabricated using a series of processes,including microwave plasma chemical vapor deposition(CVD),laser perforation,and acid immersion.This HDF was then used as a scaffold to encapsulate PEG2000.The results demonstrate that HDF significantly reduces the supercooling degree and latent heat discrepancy of PEG2000.Compared to pure PEG2000,the thermal conductivity of the HDF/PEG increased by 378%,while its latent heat reached 111.48 J/g,accompanied by a photothermal conversion efficiency of up to 86.68%.The significant performance improvement is mainly attributed to the combination of the excellent properties of the diamond with the inherent advantages of the 3D interconnected structure in HDF,which creates a high-conductivity transport network inside.Moreover,the HDF/PEG composite extends the temperature cycling time of electronic components by 4 times for heating and 2.3 times for cooling,thereby prolonging the operational lifetime of electronic devices.HDF/PEG offers an integrated solution for solar energy collection,photothermal conversion,heat dissipation in electronic components,and thermal energy transfer/storage.This innovative approach provides innovative ideas for the design and fabrication of composite PCMs and has great application potential,such as solar energy utilization,thermal management,and thermal energy storage.展开更多
Chemical vapor deposited(CVD)diamond as a burgeoning multifunctional material with tailored quality and characteristics can be artificially synthesized and controlled for various applications.Correspondingly,the appli...Chemical vapor deposited(CVD)diamond as a burgeoning multifunctional material with tailored quality and characteristics can be artificially synthesized and controlled for various applications.Correspondingly,the application-related“grade”concept associated with materials choice and design was gradually formulated,of which the availability and the performance are optimally suited.In this review,the explicit diversity of CVD diamond and the clarification of typical grades for applications,i.e.,from resplendent gem-grade to promising quantum-grade,were systematically summarized and discussed,according to the crystal quality and main consideration of ubiquitous nitrogen impurity content as well as major applications.Realizations of those,from quantum-grade with near-ideal crystal to electronic-grade having extremely low imperfections and then to optical,thermal as well as mechanical-grade needing controlled flaws and allowable impurities,would competently fulfill the multi-field application prospects with appropriate choice in terms of cost and quality.Exceptionally,wide range defects and impurities in the gem-grade diamond(only indicating single crystal),which are detrimental for technology applications,endows CVD crystals with fancy colors to challenge their natural counterparts.展开更多
Mitogen-activated protein kinase(MAPK) cascades play pivotal roles in plant defense against phytopathogens downstream of immune receptor complexes. The amplitude and duration of MAPK activation must be strictly contro...Mitogen-activated protein kinase(MAPK) cascades play pivotal roles in plant defense against phytopathogens downstream of immune receptor complexes. The amplitude and duration of MAPK activation must be strictly controlled, but the underlying mechanism remains unclear. Here, we identified Arabidopsis CPL1(C-terminal domain phosphatase-like 1)as a negative regulator of microbe-associated molecular pattern(MAMP)-triggered immunity via a forward-genetic screen. Disruption of CPL1 significantly enhanced plant resistance to Pseudomonas pathogens induced by the bacterial peptide fg22. Furthermore, fg22-induced MPK3/MPK4/MPK6 phosphorylation was dramatically elevated in cpl1 mutants but severely impaired in CPL1 overexpression lines, suggesting that CPL1 might interfere with fg22-induced MAPK activation. Indeed, CPL1 directly interacted with MPK3 and MPK6, as well as the upstream MKK4 and MKK5. A firefy luciferase-based complementation assay indicated that the interaction between MKK4/MKK5 and MPK3/MPK6 was significantly reduced in the presence of CPL1. These results suggest that CPL1 plays a novel regulatory role in suppressing MAMP-induced MAPK cascade activation and MAMP-triggered immunity to bacterial pathogens.展开更多
基金sponsored by National Key Research and Development Program of China(No.2019YFE03100200)National Natural Science Foundation of China(No.5210020483)+1 种基金Postdoc Research Foundation of Shunde Graduate School of University of Science and Technology Beijing(No.2020BH015)Fundamental Research Funds for the Central Universities(No.FRF-MP-20-48)。
文摘In this study,uniform diamond films with a diameter of 100 mm were deposited in a 15 kW/2.45 GHz ellipsoidal microwave plasma chemical vapour deposition system.A phenomenological model previously developed by our group was used to simulate the distribution of the electric strength and electron density of plasma.Results indicate that the electric field in the cavity includes multiple modes,i.e.TM_(02) and TM_(03).When the gas pressure exceeds 10 kPa,the electron density of plasma increases and plasma volume decreases.A T-shaped substrate was developed to achieve uniform temperature,and the substrate was suspended in air fromφ70 to 100 mm,thus eliminating vertical heat dissipation.An edge electric field was added to the system after the introduction of the T-shaped substrate.Moreover,the plasma volume in this case was greater than that in the central electric field but smaller than that in the periphery electric field of the TM_(02) mode.This indicates that the electric field above and below the edge benefits the plasma volume rather than the periphery electric field of the TM_(02) mode.The quality,uniformity and surface morphology of the deposited diamond films were primarily investigated to maintain substrate temperature uniformity.When employing the improved substrate,the thickness unevenness of theφ100 mm diamond film decreased from 22%to 7%.
基金the National Key Research and Development Program of China(No.2016YFE0133200)National Natural Science Foundation of China(No.52172037)+4 种基金European Union’s Horizon 2020 Research and Innovation Staff Exchange Scheme(No.734578)Post-doctor Research Foundation of Shunde Graduate School of University of Science and Technology Beijing(No.2021 BH006)Beijing Municipal Natural Science Foundation(Nos.2212036 and 4192038)Science and Technology Innovation Special Project of Foshan Government(Nos.BK20BE021 and BK21BE004)Special thanks to the nation-al high-level-university sponsored graduate program of China Scholarship Council(CSC),USTB-Monte Biance Joint R&D Center and joint-postdoc research program of Shunde Graduate School of USTB.
文摘Current electronic technology based on silicon is approaching its physical and scientific limits. Carbon-based devices have numer- ous advantages for next generation electronics (e.g., fast speed, low power consumption and simple process), that when combined with the unique nature of the versatile allotropes of carbon elements, are creating an electronics revolution. Carbon electronics are greatly advancing with new preparations and sophisticated designs. In this perspective, representatives with various dimensions, e.g., carbon nanotubes, graphene, bulk diamond, and their extraordinary performance, are reviewed. The associated state-of-the-art devices and composite hybrid all-carbon structures are also emphasized to reveal their potential in the electronics field. Advances in commercial production have improved the cost effi-ciency, material quality, and device design, accelerating the promise of carbon materials.
基金supported by the National Key Research and Development Program(No.2019YFE03100200)the State Key Lab for Advanced Metals and Materials,the Fund of National Key Laboratory of Solid-State Microwave Devices and Circuits,the National Natural Science Foundation of China(No.52102034)the Or-ganized Research Fund of North China University of Tech-nology(No.2023YZZKY12).The authors are very grateful for the financial support of these institutions.
文摘This study focused on the investigation of the edge effect of diamond films deposited by microwave plasma chemical vapor de-position.Substrate bulge height△h is a factor that affects the edge effect,and it was used to simulate plasma and guide the diamond-film deposition experiments.Finite-element software COMSOL Multiphysics was used to construct a multiphysics(electromagnetic,plasma,and fluid heat transfer fields)coupling model based on electron collision reaction.Raman spectroscopy and scanning electron microscopy were performed to characterize the experimental growth and validate the model.The simulation results reflected the experimental trends observed.Plasma discharge at the edge of the substrate accelerated due to the increase in△h(△h=0-3 mm),and the values of electron density(n_(c)),molar concentration of H(C_(H)),and molar concentration of CH_(3)(C_(CH_(3)))doubled at the edge(for the special concave sample with△h=−1 mm,the active chemical groups exhibited a decreased molar concentration at the edge of the substrate).At=0-3 mm,a high diamond growth rate and a large diamond grain size were observed at the edge of the substrate,and their values increased with.The uniformity of film thickness decreased with.The Raman spectra of all samples revealed the first-order characteristic peak of dia-mond near 1332 cm^(−1).When△h=−1 mm,tensile stress occurred in all regions of the film.When△h=1-3 mm,all areas in the film ex-hibited compressive stress.
基金financially supported by the National Key Research and Development Program of China (No.2018YFB0406501)the European Union’s Horizon 2020 Research and Innovation Staff Exchange (RISE) Scheme (No. 734578)the Beijing Natural Science Foundation (No. 4192038)。
文摘Periodic nitrogen-doped homoepitaxial nano-multilayers were grown by microwave plasma chemical vapor deposition. The residual time of gases(such as CH4and N2) in the chamber was determined by optical emission spectroscopy to determine the nano-multilayer growth process, and thin, nanoscale nitrogen-doped layers were obtained. The highest toughness of 18.2 MPa·m^(1/2)under a Young’s modulus of1000 GPa is obtained when the single-layer thickness of periodic nitrogen-doped nano-multilayers is about 96 nm. The fracture toughness of periodic nitrogen-doped CVD layer is about 2.1 times that of the HPHT seed substrate. Alternating tensile and compressive stresses are derived from periodic nitrogen doping;hence, the fracture toughness is significantly improved. Single-crystal diamond with a high toughness demonstrates wide application prospects for high-pressure anvils and single-point diamond cutting tools.
基金supported by the National Natural Science Foundation of China(Grant Nos.52176054,52236006,52172037,and 52350362)the Natural Science Foundation of Guangdong Province,China(Grant No.2024A1515012033).
文摘The use of porous skeletons for encapsulating phase change materials(PCMs)is an effective approach to addressing issues such as leakage,low thermal conductivity,and poor photothermal conversion efficiency.Inspired by the hollow skeletal structure found in birds in nature,high-quality 3D interconnected hollow diamond foam(HDF)was fabricated using a series of processes,including microwave plasma chemical vapor deposition(CVD),laser perforation,and acid immersion.This HDF was then used as a scaffold to encapsulate PEG2000.The results demonstrate that HDF significantly reduces the supercooling degree and latent heat discrepancy of PEG2000.Compared to pure PEG2000,the thermal conductivity of the HDF/PEG increased by 378%,while its latent heat reached 111.48 J/g,accompanied by a photothermal conversion efficiency of up to 86.68%.The significant performance improvement is mainly attributed to the combination of the excellent properties of the diamond with the inherent advantages of the 3D interconnected structure in HDF,which creates a high-conductivity transport network inside.Moreover,the HDF/PEG composite extends the temperature cycling time of electronic components by 4 times for heating and 2.3 times for cooling,thereby prolonging the operational lifetime of electronic devices.HDF/PEG offers an integrated solution for solar energy collection,photothermal conversion,heat dissipation in electronic components,and thermal energy transfer/storage.This innovative approach provides innovative ideas for the design and fabrication of composite PCMs and has great application potential,such as solar energy utilization,thermal management,and thermal energy storage.
基金This work was supported by the National Key Research and Development Program of China(Grant No.2016YFE0133200)the European Union’s Horizon 2020 Research and Innovation Staff Exchange Scheme(Grant No.734578)+6 种基金the Post-doctor Research Foundation of Shunde Graduate School of University of Science and Technology Beijing(Grant No.2021BH006)the National Natural Science Foundation of China(Grant No.52172037)the Beijing Municipal Natural Science Foundation(Grant Nos.2212036 and 4192038)the Fundamental Research Funds for the Central Universities(FRF-MP-20-49Z)the Science and Technology Innovation Special Project of Foshan Government(Grant Nos.BK20BE021 and BK21BE004)Special thanks to the Guangdong Basic and Applied Basic Research Foundation(Grant No.2021A1515110631)the national high-level-university sponsored graduate program of China Scholarship Council(CSC No.201806460089),USTB-Monte Biance Joint R&D Center.
文摘Chemical vapor deposited(CVD)diamond as a burgeoning multifunctional material with tailored quality and characteristics can be artificially synthesized and controlled for various applications.Correspondingly,the application-related“grade”concept associated with materials choice and design was gradually formulated,of which the availability and the performance are optimally suited.In this review,the explicit diversity of CVD diamond and the clarification of typical grades for applications,i.e.,from resplendent gem-grade to promising quantum-grade,were systematically summarized and discussed,according to the crystal quality and main consideration of ubiquitous nitrogen impurity content as well as major applications.Realizations of those,from quantum-grade with near-ideal crystal to electronic-grade having extremely low imperfections and then to optical,thermal as well as mechanical-grade needing controlled flaws and allowable impurities,would competently fulfill the multi-field application prospects with appropriate choice in terms of cost and quality.Exceptionally,wide range defects and impurities in the gem-grade diamond(only indicating single crystal),which are detrimental for technology applications,endows CVD crystals with fancy colors to challenge their natural counterparts.
基金supported by the National Natural Science Foundation of China (grant no. 31671991 to FC)。
文摘Mitogen-activated protein kinase(MAPK) cascades play pivotal roles in plant defense against phytopathogens downstream of immune receptor complexes. The amplitude and duration of MAPK activation must be strictly controlled, but the underlying mechanism remains unclear. Here, we identified Arabidopsis CPL1(C-terminal domain phosphatase-like 1)as a negative regulator of microbe-associated molecular pattern(MAMP)-triggered immunity via a forward-genetic screen. Disruption of CPL1 significantly enhanced plant resistance to Pseudomonas pathogens induced by the bacterial peptide fg22. Furthermore, fg22-induced MPK3/MPK4/MPK6 phosphorylation was dramatically elevated in cpl1 mutants but severely impaired in CPL1 overexpression lines, suggesting that CPL1 might interfere with fg22-induced MAPK activation. Indeed, CPL1 directly interacted with MPK3 and MPK6, as well as the upstream MKK4 and MKK5. A firefy luciferase-based complementation assay indicated that the interaction between MKK4/MKK5 and MPK3/MPK6 was significantly reduced in the presence of CPL1. These results suggest that CPL1 plays a novel regulatory role in suppressing MAMP-induced MAPK cascade activation and MAMP-triggered immunity to bacterial pathogens.
