This work presents an integrated microsensor that combines the dual characterization capabilities of thermogravimetric analysis(TGA)and differential thermal analysis(DTA).We integrated two pairs of thermocouples,heati...This work presents an integrated microsensor that combines the dual characterization capabilities of thermogravimetric analysis(TGA)and differential thermal analysis(DTA).We integrated two pairs of thermocouples,heating resistors,and resonant drive/detection resistors into a single microcantilever,where the cantilever resonant frequency shifts respond to the mass change and the output voltage of the integrated thermocouples respond to the sample temperature.This integration enables programmable temperature control,temperature variation,and mass detection on a single chip.Our chip can achieve heating and cooling rates above 600°C/min,which is significantly faster than commercial instruments with satisfactory measurement accuracy.The integrated polysilicon thermocouples bring high power responsivity of 6 V/W,making them suitable for highly sensitive DTA measurements on a chip.Moreover,the cantilever offers picogram(10–12g)level mass resolution,reducing sample consumption from milligrams to nanogram levels.Additionally,the on-chip sample heating allows for easy observation of sample morphological evolution during heating under an optical microscope.We validated the dual functionality by conducting TGA measurements on a standard sample of calcium oxalate monohydrate(CaC2O4∙H2O)and DTA measurements on high-purity indium(In)and tin(Sn).The results indicate consistent measurements with the true values of the standard sample and high measurement efficiency.Our integrated cantilever chip is anticipated to have broad applications in high-performance and efficient TGA and DTA characterization.展开更多
Numerical weather prediction(NWP)is the core technology for weather forecast and disaster prevention and mitigation.The research and operational applications of NWP have always been highly valued in China,and have ach...Numerical weather prediction(NWP)is the core technology for weather forecast and disaster prevention and mitigation.The research and operational applications of NWP have always been highly valued in China,and have achieved great progress with an appreciable international influence in the theories,algorithms,and operational system developments.This paper first summarizes the scientific and technological evolution of NWP in China,and then focuses on the current status and recent updates of the two homemade global NWP systems:GRAPES(Global/Regional Assimilation and PrEdiction System)and YHGSM(YinHe Global Spectral Model).(1)GRAPES possesses both deterministic and ensemble forecast systems,with global(regional)model versions running on 12-50-km(3-10-km)resolutions.Significant improvements have been made on its dynamic core,four-dimensional variational(4D-Var)assimilation,satellite and radar data assimilation,ensemble forecast,and cloud microphysics schemes,and so on.It is capable to perform subseasonal to seasonal forecast and has incorporated an atmospheric chemistry model,typhoon numerical forecast model,and ocean wave model.(2)YHGSM continues to follow the development route of spectral models,featured prominently with a dry-mass conserved spectral dynamical core,ensemble 4D-Var assimilation,coupled ocean-land-atmosphere ensemble forecast,and the medium-term and monthly-extended global high-resolution forecast as the baseline.These NWP systems autonomouly developed by the China Meteorological Administration and the national defense insitution benefit from long-term adherence to the national science and technology development strategies and close research to operation practices.展开更多
In this study,the adaption of a novel three-point multi-moment constrained finite-volume transport scheme for uniform points with center constraints(MCV3_UPCC)to cubed sphere geometry is implemented and described.For ...In this study,the adaption of a novel three-point multi-moment constrained finite-volume transport scheme for uniform points with center constraints(MCV3_UPCC)to cubed sphere geometry is implemented and described.For the MCV3_UPCC scheme,the three equidistant solution points are located within a single cell and a polynomial of 4th degree can be built by imposing the multi-moment center constraints.The resultant scheme has third-order accuracy and guarantees the exact numerical conservation.The Fourier analysis of MCV3_UPCC scheme demonstrates that the novel MCV3_UPCC has better numerical dissipation and dispersion than the original 3rd order Multi-moment Constrained finite Volume(MCV3)scheme.Then it is applied to quasi-uniform cubed-sphere grid,which is designed to avoid the polar problem on the traditional latitude–longitude grid.To suppress the non-physical numerical oscillations,a bound-preserving(BP)algorithm to constrain the conserved advected tracer to within the initial maximum and minimum values is also implemented.The scheme is validated with several widely used benchmarks involving prescribed non-divergent two-dimensional flow on the sphere and different initial tracer distributions.The resulting conservative transport model with high-order accuracy and positive preserving property is comparable to other high-order schemes and has the potential for the numerical simulation of various traces in the atmosphere.展开更多
Numerical weather prediction(NWP) is a core technology in weather forecast and disaster mitigation. China’s NWP research and operational applications have been attached great importance by the meteorological communit...Numerical weather prediction(NWP) is a core technology in weather forecast and disaster mitigation. China’s NWP research and operational applications have been attached great importance by the meteorological community.Fundamental achievements have been made in the theories, methods, and NWP model development in China, which are of certain international impacts. In this paper, the scientific and technological progress of NWP in China since1949 is summarized. The current status and recent progress of the domestically developed NWP system-GRAPES(Global/Regional Assimilation and Pr Ediction System) are presented. Through independent research and development in the past 10 years, the operational GRAPES system has been established, which includes both regional and global deterministic and ensemble prediction models, with resolutions of 3-10 km for regional and 25-50 km for global forecasts. Major improvements include establishment of a new non-hydrostatic dynamic core, setup of four-dimensional variational data assimilation, and development of associated satellite application. As members of the GRAPES system, prediction models for atmospheric chemistry and air pollution, tropical cyclones, and ocean waves have also been developed and put into operational use. The GRAPES system has been an important milestone in NWP science and technology in China.展开更多
基金funded by the National Key R&D Program of China(2021YFB3200800)National Natural Science Foundation of China(62227815,61831021,62271473,62104241,U21A20500)Innovation Team and Talents Cultivation Program of National Administration of Traditional Chinese Medicine(ZYYCXTD-D-202002,ZYYCXTD-D-202003).
文摘This work presents an integrated microsensor that combines the dual characterization capabilities of thermogravimetric analysis(TGA)and differential thermal analysis(DTA).We integrated two pairs of thermocouples,heating resistors,and resonant drive/detection resistors into a single microcantilever,where the cantilever resonant frequency shifts respond to the mass change and the output voltage of the integrated thermocouples respond to the sample temperature.This integration enables programmable temperature control,temperature variation,and mass detection on a single chip.Our chip can achieve heating and cooling rates above 600°C/min,which is significantly faster than commercial instruments with satisfactory measurement accuracy.The integrated polysilicon thermocouples bring high power responsivity of 6 V/W,making them suitable for highly sensitive DTA measurements on a chip.Moreover,the cantilever offers picogram(10–12g)level mass resolution,reducing sample consumption from milligrams to nanogram levels.Additionally,the on-chip sample heating allows for easy observation of sample morphological evolution during heating under an optical microscope.We validated the dual functionality by conducting TGA measurements on a standard sample of calcium oxalate monohydrate(CaC2O4∙H2O)and DTA measurements on high-purity indium(In)and tin(Sn).The results indicate consistent measurements with the true values of the standard sample and high measurement efficiency.Our integrated cantilever chip is anticipated to have broad applications in high-performance and efficient TGA and DTA characterization.
基金Supported by the National Key Research and Development Program of China(2021YFC3101500).
文摘Numerical weather prediction(NWP)is the core technology for weather forecast and disaster prevention and mitigation.The research and operational applications of NWP have always been highly valued in China,and have achieved great progress with an appreciable international influence in the theories,algorithms,and operational system developments.This paper first summarizes the scientific and technological evolution of NWP in China,and then focuses on the current status and recent updates of the two homemade global NWP systems:GRAPES(Global/Regional Assimilation and PrEdiction System)and YHGSM(YinHe Global Spectral Model).(1)GRAPES possesses both deterministic and ensemble forecast systems,with global(regional)model versions running on 12-50-km(3-10-km)resolutions.Significant improvements have been made on its dynamic core,four-dimensional variational(4D-Var)assimilation,satellite and radar data assimilation,ensemble forecast,and cloud microphysics schemes,and so on.It is capable to perform subseasonal to seasonal forecast and has incorporated an atmospheric chemistry model,typhoon numerical forecast model,and ocean wave model.(2)YHGSM continues to follow the development route of spectral models,featured prominently with a dry-mass conserved spectral dynamical core,ensemble 4D-Var assimilation,coupled ocean-land-atmosphere ensemble forecast,and the medium-term and monthly-extended global high-resolution forecast as the baseline.These NWP systems autonomouly developed by the China Meteorological Administration and the national defense insitution benefit from long-term adherence to the national science and technology development strategies and close research to operation practices.
基金Supported by the National Natural Science Foundation of China(42275168 and 42105002)。
文摘In this study,the adaption of a novel three-point multi-moment constrained finite-volume transport scheme for uniform points with center constraints(MCV3_UPCC)to cubed sphere geometry is implemented and described.For the MCV3_UPCC scheme,the three equidistant solution points are located within a single cell and a polynomial of 4th degree can be built by imposing the multi-moment center constraints.The resultant scheme has third-order accuracy and guarantees the exact numerical conservation.The Fourier analysis of MCV3_UPCC scheme demonstrates that the novel MCV3_UPCC has better numerical dissipation and dispersion than the original 3rd order Multi-moment Constrained finite Volume(MCV3)scheme.Then it is applied to quasi-uniform cubed-sphere grid,which is designed to avoid the polar problem on the traditional latitude–longitude grid.To suppress the non-physical numerical oscillations,a bound-preserving(BP)algorithm to constrain the conserved advected tracer to within the initial maximum and minimum values is also implemented.The scheme is validated with several widely used benchmarks involving prescribed non-divergent two-dimensional flow on the sphere and different initial tracer distributions.The resulting conservative transport model with high-order accuracy and positive preserving property is comparable to other high-order schemes and has the potential for the numerical simulation of various traces in the atmosphere.
基金Supported by the National Key Research and Development Program of China(2017YFC1501900)Middle-and Long-term Development Strategic Research Project of the Chinese Academy of Engineering(2019-ZCQ-06)。
文摘Numerical weather prediction(NWP) is a core technology in weather forecast and disaster mitigation. China’s NWP research and operational applications have been attached great importance by the meteorological community.Fundamental achievements have been made in the theories, methods, and NWP model development in China, which are of certain international impacts. In this paper, the scientific and technological progress of NWP in China since1949 is summarized. The current status and recent progress of the domestically developed NWP system-GRAPES(Global/Regional Assimilation and Pr Ediction System) are presented. Through independent research and development in the past 10 years, the operational GRAPES system has been established, which includes both regional and global deterministic and ensemble prediction models, with resolutions of 3-10 km for regional and 25-50 km for global forecasts. Major improvements include establishment of a new non-hydrostatic dynamic core, setup of four-dimensional variational data assimilation, and development of associated satellite application. As members of the GRAPES system, prediction models for atmospheric chemistry and air pollution, tropical cyclones, and ocean waves have also been developed and put into operational use. The GRAPES system has been an important milestone in NWP science and technology in China.
