In this paper, a two level finite difference scheme of Crank-Nicholson type is constructed and used to numerically investigate nonlinear temperature distribution in biological tissues described by bioheat transfer equ...In this paper, a two level finite difference scheme of Crank-Nicholson type is constructed and used to numerically investigate nonlinear temperature distribution in biological tissues described by bioheat transfer equation of Pennes’ type. For the equation under consideration, the thermal conductivity is either depth-dependent or tem-perature-dependent, while blood perfusion is temperature-dependent. In both cases of depth- dependent and temperature-dependent thermal conductivity, it is shown that blood perfusion decreases the temperature of the living tissue. Our numerical simulations show that neither the localization nor the magnitude of peak tempera-ture is affected by surface temperature;however, the width of peak temperature increases with surface temperature.展开更多
PENN STATE/NCAR MM5 is used to simulate precipitation of the heavy rain process during 12-13 July 1994.The effects of different PBL parameterizations,resolvable scale moisture schemes and cumulus parameterization on t...PENN STATE/NCAR MM5 is used to simulate precipitation of the heavy rain process during 12-13 July 1994.The effects of different PBL parameterizations,resolvable scale moisture schemes and cumulus parameterization on the process rainfall simulation are investigated.By comparing the results of hydrostatic and nor.hydrostatic experiments,the nonhydrostatic impact upon precipitation is also examined.It is found in this study thai PENN STATE/NCAR MM5 has advantage not only in theory but also in simulating results with real data.In MM5.however,the selection of physical processes,especially water-cycle process,is very important and crucial to precipitation forecast of the case.It is concluded that the model with Grell (1993) scheme for convection and condensation method for resolvable scale precipitation captured the rainstorm during 12-13 July 1994 in Beijing area more successfully展开更多
Robert Penn Warren(1905-1989) is one of twentieth-century America's most distinguished men of letters.Honored with three Pulitzer Prizes,Warren is the only writer who has been a Pulitzer Prize winner in two differ...Robert Penn Warren(1905-1989) is one of twentieth-century America's most distinguished men of letters.Honored with three Pulitzer Prizes,Warren is the only writer who has been a Pulitzer Prize winner in two different genres-poetry and fiction.In 1986,Warren was crowned as the first American Poet Laureate.Though he is a Renaissance man of letters in many genres,the central thrust of Warren's literary career lies in the field of poetry.Love and knowledge are the two themes which penetrate his sixty years' poetic career.Based on textual analysis,applying the method of close reading,the present study intends to explore the sound patterning,metaphor,tension and the technical devices which reinforce the theme of love and knowledge in the poem of the Bearded Oaks.展开更多
Based on modified version of the Pennes' bio-heat transfer equation, a simplified one- dimensional bio-heat transfer model of the living tissues in the steady state has been applied on whole body heat transfer stu...Based on modified version of the Pennes' bio-heat transfer equation, a simplified one- dimensional bio-heat transfer model of the living tissues in the steady state has been applied on whole body heat transfer studies, and by using the Weierstrass' elliptic function, its corresponding analytic periodic and non-periodic solutions have been derived in this paper. Using the obtained analytic solutions, the effects of the thermal diffusivity, the temperature-inde- pendent perfusion component, and the temperature-dependent perfusion component in living tissues are analyzed numerically. The results show that the derived analytic solution is useful to easily and accurately study the thermal behavior of the biological system, and can be extended to applications such as parameter measurement, temperature field reconstruction and clinical treatment.展开更多
The Penn State Worry Questionnaire(PSWQ) is a measure of worry phenomena and has been demonstrated valid in cross-cultural populations. The present study examined the factor structure and psychometric properties of th...The Penn State Worry Questionnaire(PSWQ) is a measure of worry phenomena and has been demonstrated valid in cross-cultural populations. The present study examined the factor structure and psychometric properties of the Chinese version of PSWQ(Ch-PSWQ) in a Chinese college sample(n=1243). Exploratory factor analysis of the Ch-PSWQ revealed a two-factor solution(engagement of worry and absence of worry). Confirmatory factor analysis and model comparison supported that the model of one factor with method effect provided the best fit to the data. The Ch-PSWQ and its factors evidenced good internal consistency and both convergent and discriminate validity. The present study supports the opinion that the second factor of PSWQ not only contains the component of evaluating pathological worry,but also might represent other traits.展开更多
Based on the Pennes’ bioheat transfer equation, a simplified one-dimensional bioheat transfer model of the cylindrical living tissues in the steady state has been set up for application in limb and whole body heat tr...Based on the Pennes’ bioheat transfer equation, a simplified one-dimensional bioheat transfer model of the cylindrical living tissues in the steady state has been set up for application in limb and whole body heat transfer studies, and by using the Bessel’s equation, its corresponding analytic solution has been derived in this paper. With the obtained analytic solution, the effects of the thermal conductivity, the blood perfusion, the metabolic heat generation, and the coefficient of heat transfer on the temperature distribution in living tissues are analyzed. The results show that the derived analytic solution is useful to easily and accurately study the thermal behavior of the biological system, and can be extended to such applications as parameter measurement, temperature field reconstruction and clinical treatment.展开更多
In this paper we estimate relative consumer price levels as of 2008 for 36 major Chinese cities, using an innovative method purposely designed to rectify three main defects of the existing literature, which are （1） ...In this paper we estimate relative consumer price levels as of 2008 for 36 major Chinese cities, using an innovative method purposely designed to rectify three main defects of the existing literature, which are （1） the under-representation of marketized services in the sample data, （2） biased consumption weights, and （3） a mismatch between sample classification and consumption weights. Our estimation results show the ＂subnational Penn effect＂ as defined by Tang （2012）, i.e., strong inter-city correlations among population size, the relative price level, per capita nominal and real income, and human capital stock, thereby showing that the theoretical model of inter-city price dispersion proposed by Tang （2012） is applicable in China. Our conclusion, methodology, and estimation results have important implications for various aspects of the Chinese economy including the regional, urban and real-estate economies.展开更多
As an extension of the neoclassical urban systems theory （Henderson, 1974）, we develop a general theory of regional （inter-city） price dispersion which also explains the ＂subnational Penn effect,＂ i.e., cross-ci...As an extension of the neoclassical urban systems theory （Henderson, 1974）, we develop a general theory of regional （inter-city） price dispersion which also explains the ＂subnational Penn effect,＂ i.e., cross-city correlations among population size, prices, real income and human capital stock. The model is also a theory of international price dispersion that is observationally equivalent to and more appealing than the Balassa-Samuelson theory, implying that the （international） Penn effect may simply be an aggregate result of the ＂subnational Penn effect.＂ Furthermore, it shows that, contrary to the popular view, economic integration can increase as well as decrease spatial price variation.展开更多
文摘In this paper, a two level finite difference scheme of Crank-Nicholson type is constructed and used to numerically investigate nonlinear temperature distribution in biological tissues described by bioheat transfer equation of Pennes’ type. For the equation under consideration, the thermal conductivity is either depth-dependent or tem-perature-dependent, while blood perfusion is temperature-dependent. In both cases of depth- dependent and temperature-dependent thermal conductivity, it is shown that blood perfusion decreases the temperature of the living tissue. Our numerical simulations show that neither the localization nor the magnitude of peak tempera-ture is affected by surface temperature;however, the width of peak temperature increases with surface temperature.
基金This work was supported by LASGthe National Natural Science Foundation of China
文摘PENN STATE/NCAR MM5 is used to simulate precipitation of the heavy rain process during 12-13 July 1994.The effects of different PBL parameterizations,resolvable scale moisture schemes and cumulus parameterization on the process rainfall simulation are investigated.By comparing the results of hydrostatic and nor.hydrostatic experiments,the nonhydrostatic impact upon precipitation is also examined.It is found in this study thai PENN STATE/NCAR MM5 has advantage not only in theory but also in simulating results with real data.In MM5.however,the selection of physical processes,especially water-cycle process,is very important and crucial to precipitation forecast of the case.It is concluded that the model with Grell (1993) scheme for convection and condensation method for resolvable scale precipitation captured the rainstorm during 12-13 July 1994 in Beijing area more successfully
文摘Robert Penn Warren(1905-1989) is one of twentieth-century America's most distinguished men of letters.Honored with three Pulitzer Prizes,Warren is the only writer who has been a Pulitzer Prize winner in two different genres-poetry and fiction.In 1986,Warren was crowned as the first American Poet Laureate.Though he is a Renaissance man of letters in many genres,the central thrust of Warren's literary career lies in the field of poetry.Love and knowledge are the two themes which penetrate his sixty years' poetic career.Based on textual analysis,applying the method of close reading,the present study intends to explore the sound patterning,metaphor,tension and the technical devices which reinforce the theme of love and knowledge in the poem of the Bearded Oaks.
文摘Based on modified version of the Pennes' bio-heat transfer equation, a simplified one- dimensional bio-heat transfer model of the living tissues in the steady state has been applied on whole body heat transfer studies, and by using the Weierstrass' elliptic function, its corresponding analytic periodic and non-periodic solutions have been derived in this paper. Using the obtained analytic solutions, the effects of the thermal diffusivity, the temperature-inde- pendent perfusion component, and the temperature-dependent perfusion component in living tissues are analyzed numerically. The results show that the derived analytic solution is useful to easily and accurately study the thermal behavior of the biological system, and can be extended to applications such as parameter measurement, temperature field reconstruction and clinical treatment.
基金supported by the Soft Science Office of Beijing MunicipalScience and Technology Commission of China(No.Z000608100007110)the German Academic Exchange Service(No.2006-3139)
文摘The Penn State Worry Questionnaire(PSWQ) is a measure of worry phenomena and has been demonstrated valid in cross-cultural populations. The present study examined the factor structure and psychometric properties of the Chinese version of PSWQ(Ch-PSWQ) in a Chinese college sample(n=1243). Exploratory factor analysis of the Ch-PSWQ revealed a two-factor solution(engagement of worry and absence of worry). Confirmatory factor analysis and model comparison supported that the model of one factor with method effect provided the best fit to the data. The Ch-PSWQ and its factors evidenced good internal consistency and both convergent and discriminate validity. The present study supports the opinion that the second factor of PSWQ not only contains the component of evaluating pathological worry,but also might represent other traits.
文摘Based on the Pennes’ bioheat transfer equation, a simplified one-dimensional bioheat transfer model of the cylindrical living tissues in the steady state has been set up for application in limb and whole body heat transfer studies, and by using the Bessel’s equation, its corresponding analytic solution has been derived in this paper. With the obtained analytic solution, the effects of the thermal conductivity, the blood perfusion, the metabolic heat generation, and the coefficient of heat transfer on the temperature distribution in living tissues are analyzed. The results show that the derived analytic solution is useful to easily and accurately study the thermal behavior of the biological system, and can be extended to such applications as parameter measurement, temperature field reconstruction and clinical treatment.
文摘In this paper we estimate relative consumer price levels as of 2008 for 36 major Chinese cities, using an innovative method purposely designed to rectify three main defects of the existing literature, which are （1） the under-representation of marketized services in the sample data, （2） biased consumption weights, and （3） a mismatch between sample classification and consumption weights. Our estimation results show the ＂subnational Penn effect＂ as defined by Tang （2012）, i.e., strong inter-city correlations among population size, the relative price level, per capita nominal and real income, and human capital stock, thereby showing that the theoretical model of inter-city price dispersion proposed by Tang （2012） is applicable in China. Our conclusion, methodology, and estimation results have important implications for various aspects of the Chinese economy including the regional, urban and real-estate economies.
文摘As an extension of the neoclassical urban systems theory （Henderson, 1974）, we develop a general theory of regional （inter-city） price dispersion which also explains the ＂subnational Penn effect,＂ i.e., cross-city correlations among population size, prices, real income and human capital stock. The model is also a theory of international price dispersion that is observationally equivalent to and more appealing than the Balassa-Samuelson theory, implying that the （international） Penn effect may simply be an aggregate result of the ＂subnational Penn effect.＂ Furthermore, it shows that, contrary to the popular view, economic integration can increase as well as decrease spatial price variation.
