In this study,we derived atmospheric profiles of temperature,moisture,and ozone,along with surface emissivity,skin temperature,and surface pressure,from infrared-sounder radiances under clear sky (cloudless) condition...In this study,we derived atmospheric profiles of temperature,moisture,and ozone,along with surface emissivity,skin temperature,and surface pressure,from infrared-sounder radiances under clear sky (cloudless) condition.Clouds were detected objectively using the Atmospheric Infrared Sounder under a relatively low spatial resolution and cloud-mask information from the Moderate Resolution Imaging Spectroradiometer under a high horizontal resolution;this detection was conducted using space matching.Newton’s nonlinear physical iterative solution technique is applied to the radiative transfer equation (RTE) to retrieve temperature profiles,relative humidity profiles,and surface variables simultaneously.This technique is carried out by using the results of an eigenvector regression retrieval as the background profile and using corresponding iterative forms for the weighting functions of temperature and water-vapor mixing ratio.The iterative forms are obtained by applying the variational principle to the RTE.We also compared the retrievals obtained with different types of observations.The results show that the retrieved atmospheric sounding profile has great superiority over other observations by accuracy and resolution.Retrieved profiles can be used to improve the initial conditions of numerical models and used in areas where conventional observations are sparse,such as plateaus,deserts,and seas.展开更多
The Qinling-Dabie orogen is an important tectonic belt that trends east-west and divides continental China into northern and southern parts.Due to its strong deformation,complicated structure,multiphase structural sup...The Qinling-Dabie orogen is an important tectonic belt that trends east-west and divides continental China into northern and southern parts.Due to its strong deformation,complicated structure,multiphase structural superposition and the massive exposed high and ultrahigh metamorphic rocks,its tectonic formation and geodynamical evolution are hot research topics worldwide.Previous studies mainly focused on the regional geological or geochemical aspects,whereas the geophysical constraints are few and isolated,in particular on the orogenic scale.Here,we integrate the available P- and S-wave seismic and seismicity data,and construct the rheological structures along the Qinling-Dabie orogen.The results demonstrate that:(1)there are strong lateral variations in the crustal velocity between the western and eastern sections of the Qinling-Dabie orogen,indicating the different origin and tectonic evolution between these two parts;(2) the lateral variations are also manifested in the rheological structure.The rigid blocks,such as South China and Ordos basin(North China Craton),resist deformation and show low seismicity.The weak regions,such as the margin of Tibet and western Qinling-Dabie experience strong deformation and accumulated stress,thus show active seismicity;(3) in the lower crust of most of the HP/UHP terranes the values of P-wave velocity are higher than the global average ones;finally(4) low P- and S-wave velocities and low strength in the lower crust and lithospheric mantle beneath Dabie indicate lithospheric delamination,and/or high temperature,and partial melting condition.展开更多
Besides safety and low-cost,the start/shutdown/restarting and throttling ability are the other two significant advantages of hy-brid rocket motors(HRMs) compared with liquid and solid ones.In this study,a two-stage va...Besides safety and low-cost,the start/shutdown/restarting and throttling ability are the other two significant advantages of hy-brid rocket motors(HRMs) compared with liquid and solid ones.In this study,a two-stage variable thrust and non-toxic 98%HP/HTPB hybrid rocket motor(VTHRM) is designed and applied in a sounding rocket,and the design parameters of the motor are analyzed and optimized.A computational program is developed to design the motor system structure,to predict the interior ballistics and the ballistic trajectory.A star grain and a wheel grain are compared.The design of experiment(DOE),variance analysis and the main effect analysis are employed to investigate the influence of the main design parameters on mo-tor performance.The multidiscipline feasible(MDF) approach is applied to establish the optimization procedure after analyz-ing the system design structure matrix.A modified differential evolution algorithm is employed to maximize the load mass.The results indicate that the wheel grain could obtain a larger load mass and a lower length to diameter ratio,and that throttling markedly meliorates the motor and rocket performance.The conclusions drawn from the analysis and optimization could pro-vide instructive guide and theoretical basis for engineering designs.展开更多
This is a qualitative study of the types of segmental repair that maintain mutual intelligibility in English-as-a-Lingua-Franca interactions among Chinese and Japanese speakers of English （Jenkins, 2000; Matsumoto 20...This is a qualitative study of the types of segmental repair that maintain mutual intelligibility in English-as-a-Lingua-Franca interactions among Chinese and Japanese speakers of English （Jenkins, 2000; Matsumoto 2011; O＇Neal 2015a, 2015b, 2015c, 2015d, 2016, in press）. Repair refers to a set of practices through which conversation participants stop the ongoing action to attend to actual or potential problems 1：o the maintenance of mutual intelligibility （Schegloff, 2007; N^meth, 2012）. Although anything can potentially be a problem to the maintenance of mutual intelligibility, this study focuses only on instances of the repair of segmental phonemes so that the pronunciation remains mutually intelligible. Using conversation analytic methodology to examine a corpus of repair sequences concerning pronunciation among Chinese and Japanese students at a Japanese university, this study claims that three segmental repair strategies are used in the interactions to maintain mutually intelligible pronunciation： segmental phoneme modification, segmental phoneme insertion, and segmental phoneme deletion.展开更多
基金project of the Ministry of Sciences and Technology of the People’s Republic of China (GYHY200706020)projects of National Natural Science Foundation of China ((40975034, 40505009)project of State Key Laboratory of Severe Weather (2008LASW-A01)
文摘In this study,we derived atmospheric profiles of temperature,moisture,and ozone,along with surface emissivity,skin temperature,and surface pressure,from infrared-sounder radiances under clear sky (cloudless) condition.Clouds were detected objectively using the Atmospheric Infrared Sounder under a relatively low spatial resolution and cloud-mask information from the Moderate Resolution Imaging Spectroradiometer under a high horizontal resolution;this detection was conducted using space matching.Newton’s nonlinear physical iterative solution technique is applied to the radiative transfer equation (RTE) to retrieve temperature profiles,relative humidity profiles,and surface variables simultaneously.This technique is carried out by using the results of an eigenvector regression retrieval as the background profile and using corresponding iterative forms for the weighting functions of temperature and water-vapor mixing ratio.The iterative forms are obtained by applying the variational principle to the RTE.We also compared the retrievals obtained with different types of observations.The results show that the retrieved atmospheric sounding profile has great superiority over other observations by accuracy and resolution.Retrieved profiles can be used to improve the initial conditions of numerical models and used in areas where conventional observations are sparse,such as plateaus,deserts,and seas.
基金support offered by the Strategic Priority Research Program(B) of the Chinese Academy of Sciences(Grant No.XDB18030101)the National Natural Science Foundation of China(Grant No.41504069) and the Italian Projects PRIN 2010-2011, PRIN 2015
文摘The Qinling-Dabie orogen is an important tectonic belt that trends east-west and divides continental China into northern and southern parts.Due to its strong deformation,complicated structure,multiphase structural superposition and the massive exposed high and ultrahigh metamorphic rocks,its tectonic formation and geodynamical evolution are hot research topics worldwide.Previous studies mainly focused on the regional geological or geochemical aspects,whereas the geophysical constraints are few and isolated,in particular on the orogenic scale.Here,we integrate the available P- and S-wave seismic and seismicity data,and construct the rheological structures along the Qinling-Dabie orogen.The results demonstrate that:(1)there are strong lateral variations in the crustal velocity between the western and eastern sections of the Qinling-Dabie orogen,indicating the different origin and tectonic evolution between these two parts;(2) the lateral variations are also manifested in the rheological structure.The rigid blocks,such as South China and Ordos basin(North China Craton),resist deformation and show low seismicity.The weak regions,such as the margin of Tibet and western Qinling-Dabie experience strong deformation and accumulated stress,thus show active seismicity;(3) in the lower crust of most of the HP/UHP terranes the values of P-wave velocity are higher than the global average ones;finally(4) low P- and S-wave velocities and low strength in the lower crust and lithospheric mantle beneath Dabie indicate lithospheric delamination,and/or high temperature,and partial melting condition.
文摘Besides safety and low-cost,the start/shutdown/restarting and throttling ability are the other two significant advantages of hy-brid rocket motors(HRMs) compared with liquid and solid ones.In this study,a two-stage variable thrust and non-toxic 98%HP/HTPB hybrid rocket motor(VTHRM) is designed and applied in a sounding rocket,and the design parameters of the motor are analyzed and optimized.A computational program is developed to design the motor system structure,to predict the interior ballistics and the ballistic trajectory.A star grain and a wheel grain are compared.The design of experiment(DOE),variance analysis and the main effect analysis are employed to investigate the influence of the main design parameters on mo-tor performance.The multidiscipline feasible(MDF) approach is applied to establish the optimization procedure after analyz-ing the system design structure matrix.A modified differential evolution algorithm is employed to maximize the load mass.The results indicate that the wheel grain could obtain a larger load mass and a lower length to diameter ratio,and that throttling markedly meliorates the motor and rocket performance.The conclusions drawn from the analysis and optimization could pro-vide instructive guide and theoretical basis for engineering designs.
文摘This is a qualitative study of the types of segmental repair that maintain mutual intelligibility in English-as-a-Lingua-Franca interactions among Chinese and Japanese speakers of English （Jenkins, 2000; Matsumoto 2011; O＇Neal 2015a, 2015b, 2015c, 2015d, 2016, in press）. Repair refers to a set of practices through which conversation participants stop the ongoing action to attend to actual or potential problems 1：o the maintenance of mutual intelligibility （Schegloff, 2007; N^meth, 2012）. Although anything can potentially be a problem to the maintenance of mutual intelligibility, this study focuses only on instances of the repair of segmental phonemes so that the pronunciation remains mutually intelligible. Using conversation analytic methodology to examine a corpus of repair sequences concerning pronunciation among Chinese and Japanese students at a Japanese university, this study claims that three segmental repair strategies are used in the interactions to maintain mutually intelligible pronunciation： segmental phoneme modification, segmental phoneme insertion, and segmental phoneme deletion.
