This study investigates the potential formation of subglacial lakes beneath the glaciers of the Franz Josef Land archipelago,Russian Arctic,under current and future climatic conditions.Using a one-dimensional heat and...This study investigates the potential formation of subglacial lakes beneath the glaciers of the Franz Josef Land archipelago,Russian Arctic,under current and future climatic conditions.Using a one-dimensional heat and mass transfer model,the research evaluates the influence of geothermal heat flow,ice thickness,and surface temperature on basal melting.The model incorporates enthalpy formulation and boundary conditions derived from field data,including temperature profiles and geothermal measurements.Results indicate that subglacial lakes could form under ice masses exceeding 300 m thickness,driven by geothermal heating,though current basal temperatures remain below the melting point.Simulations under the IPCC SSP1-2.6 scenario suggest a gradual warming trend,highlighting the long-term thermal inertia of Arctic glaciers.The study underscores the need for enhanced observational data to validate models and improve predictions of glacial dynamics in response to climate change.展开更多
We have performed a full numerical calculation of the Franz-Keldysh （FK） effect on magnetoexcitons in a bulk GaAs semiconductor. By employing an initial wlue method in combination with the application of a perfect m...We have performed a full numerical calculation of the Franz-Keldysh （FK） effect on magnetoexcitons in a bulk GaAs semiconductor. By employing an initial wlue method in combination with the application of a perfect matched layer, the numerical effort and storage size are dramatically reduced due to a significant reduction in both computed domain and number of base functions. In the absence of an electric field, the higher magnetoexcitonic peaks show distinct Fano lineshape due to the degeneracy with continuum states of the lower Landau levels. The magnetoexcitons that belong to the zeroth Landau level remain in bound states and lead to Lorentzian lineshape, because they are not degenerated with continuum states. In the presence of an electric field, the FK effect on each magnetoexcitonic resonance can be identified for high magnetic fields. However, for low magnetic fields, the FK oscillations dominate the spectrum structure in the vicinity of the bandgap edge and the magnetoexcitonic resonances dominate the spectrum structure of higher energies. In the moderate electric fields, the interplay of FK effect and magnetoexcitonic resonance leads to a complex and rich structure in the absorption spectrum.展开更多
In this paper the influence of superconducting correlations on the thermal and charge conductances in a normal metal-superconductor （NS） junction in the clean limit is studied theoretically. First we solve the quasi...In this paper the influence of superconducting correlations on the thermal and charge conductances in a normal metal-superconductor （NS） junction in the clean limit is studied theoretically. First we solve the quasiclassical Eilenberger equations, and using the obtained density of states we can acquire the thermal and electrical conductances for the NS junction. Then we compare the conductance in a normal region of an NS junction with that in a single layer of normal metal （N）. Moreover, we study the Wiedemann-Franz （WF） law for these two cases （iN and NS）. From our calculations we conclude that the behaviour of the NS junction does not conform to the WF law for all temperatures. The effect of the thickness of normal metal on the thermal conductivity is also theoretically investigated in the paper.展开更多
In this paper, the author mainly discusses the life of Franz Boas and Edward Sapir and their major contributions. Then does further discussions on Sapir-Whorf Hypothesis from different aspects.
The problem of "life and death" has been a confusing proposition of philosophy since long ago,for which philosophers both at home and abroad take great pains to pursue the answer.The problem of"life and...The problem of "life and death" has been a confusing proposition of philosophy since long ago,for which philosophers both at home and abroad take great pains to pursue the answer.The problem of"life and death"is also attractive for litterateurs.This paper attempts to scrutinize the works of Franz Kafka and based on comments of different critics,simply analyzing the theory of survival and the theory of death and exploring the aesthetic value.Through analysis,the author of this paper concludes that the theory of survival in the works of Kafka tends to express hating of not being favored by chances and the fright and anxiety of the time;on the contrary,the theory of death in his works tends to express worship and belief.Both life and death are expressed vividly in his works,showing the brave pursuit of senior artistic forms of Kafka and the essence of its aesthetic value.展开更多
Traditional Chinese medicine(TCM)is the cultural heritage of all humankind.TCM not only embodies the cultural crystallization of the region and the nation,but also performs the important mission of curing the lives,sa...Traditional Chinese medicine(TCM)is the cultural heritage of all humankind.TCM not only embodies the cultural crystallization of the region and the nation,but also performs the important mission of curing the lives,saving the sick and maintaining the health of the people.In the history of the spread of Chinese medicine to the West,foreign missionaries have played an important role,and researches about this role have continued in China.In the history of Chinese medicine in Germany,there is a pivotal figure named Franz Hübotter(1881-1967),who broke through the deadlock in the academic research of Chinese medicine in the 19th century in Germany,but the discussion on his contribution has been comparatively rare in China.His works and translations are not only of medical value,but are also valuable historically,culturally,and socially.The historical development of TCM has the authenticity of history,the integrity of the environment,and the richness of the times.Medical experts have explored and verified the value of medicine.Translators and scholars are mainly concerned with the dissemination of knowledge from an intercultural perspective.This paper provides a primitive and objective introduction to Franz Hübotter,hoping to trigger off the secondary research among scholars of different professional backgrounds and to expand professional thinking,and then get over the barriers of disciplines.展开更多
The Wiedemann–Franz(WF)law,a foundational principle in condensed matter physics,posits a direct proportionality between the electronic contributions to thermal and electrical conductivity.However,recent experimental ...The Wiedemann–Franz(WF)law,a foundational principle in condensed matter physics,posits a direct proportionality between the electronic contributions to thermal and electrical conductivity.However,recent experimental observations,particularly in materials like vanadium dioxide(VO2),have revealed significant violations of this law.Furthermore,a growing body of evidence indicates its inapplicability under cryogenic conditions,highlighting the need for a more comprehensive theoretical framework.This study addresses this discrepancy by deriving a generalized WF law.Beginning with the thermodynamic potential of a relativistic degenerate electron gas and electron density functions,we employ a swallowtail catastrophe model grounded in structural stability principles,in conjunction with non-dimensional analysis.The resulting formulation yields a general WF law that correctly satisfies the boundary conditions at both cryogenic and infinite-temperature limits.Our findings reveal that the relationship between thermal and electrical conductivity is fundamentally nonlinear,intrinsically dependent on the material’s relaxation time and chemical potential.To validate our framework,we have applied the derived law to calculate the thermal conductivity of VO_(2),achieving excellent agreement with previously reported experimental data.This generalized WF law provides a robust theoretical tool for analyzing electron transport phenomena and holds significant potential for investigating phase transitions in metals and superconductors.展开更多
基金supported by the Shanghai Science and Technology Innovation Action Plan(Grant no.23230712200).
文摘This study investigates the potential formation of subglacial lakes beneath the glaciers of the Franz Josef Land archipelago,Russian Arctic,under current and future climatic conditions.Using a one-dimensional heat and mass transfer model,the research evaluates the influence of geothermal heat flow,ice thickness,and surface temperature on basal melting.The model incorporates enthalpy formulation and boundary conditions derived from field data,including temperature profiles and geothermal measurements.Results indicate that subglacial lakes could form under ice masses exceeding 300 m thickness,driven by geothermal heating,though current basal temperatures remain below the melting point.Simulations under the IPCC SSP1-2.6 scenario suggest a gradual warming trend,highlighting the long-term thermal inertia of Arctic glaciers.The study underscores the need for enhanced observational data to validate models and improve predictions of glacial dynamics in response to climate change.
基金Project supported by the Major Program of the National Natural Science Foundation of China （Grant No 10390160）, and the National Natural Science Foundation of China （Grant No 30370420）.
文摘We have performed a full numerical calculation of the Franz-Keldysh （FK） effect on magnetoexcitons in a bulk GaAs semiconductor. By employing an initial wlue method in combination with the application of a perfect matched layer, the numerical effort and storage size are dramatically reduced due to a significant reduction in both computed domain and number of base functions. In the absence of an electric field, the higher magnetoexcitonic peaks show distinct Fano lineshape due to the degeneracy with continuum states of the lower Landau levels. The magnetoexcitons that belong to the zeroth Landau level remain in bound states and lead to Lorentzian lineshape, because they are not degenerated with continuum states. In the presence of an electric field, the FK effect on each magnetoexcitonic resonance can be identified for high magnetic fields. However, for low magnetic fields, the FK oscillations dominate the spectrum structure in the vicinity of the bandgap edge and the magnetoexcitonic resonances dominate the spectrum structure of higher energies. In the moderate electric fields, the interplay of FK effect and magnetoexcitonic resonance leads to a complex and rich structure in the absorption spectrum.
文摘In this paper the influence of superconducting correlations on the thermal and charge conductances in a normal metal-superconductor （NS） junction in the clean limit is studied theoretically. First we solve the quasiclassical Eilenberger equations, and using the obtained density of states we can acquire the thermal and electrical conductances for the NS junction. Then we compare the conductance in a normal region of an NS junction with that in a single layer of normal metal （N）. Moreover, we study the Wiedemann-Franz （WF） law for these two cases （iN and NS）. From our calculations we conclude that the behaviour of the NS junction does not conform to the WF law for all temperatures. The effect of the thickness of normal metal on the thermal conductivity is also theoretically investigated in the paper.
文摘In this paper, the author mainly discusses the life of Franz Boas and Edward Sapir and their major contributions. Then does further discussions on Sapir-Whorf Hypothesis from different aspects.
文摘The problem of "life and death" has been a confusing proposition of philosophy since long ago,for which philosophers both at home and abroad take great pains to pursue the answer.The problem of"life and death"is also attractive for litterateurs.This paper attempts to scrutinize the works of Franz Kafka and based on comments of different critics,simply analyzing the theory of survival and the theory of death and exploring the aesthetic value.Through analysis,the author of this paper concludes that the theory of survival in the works of Kafka tends to express hating of not being favored by chances and the fright and anxiety of the time;on the contrary,the theory of death in his works tends to express worship and belief.Both life and death are expressed vividly in his works,showing the brave pursuit of senior artistic forms of Kafka and the essence of its aesthetic value.
文摘Traditional Chinese medicine(TCM)is the cultural heritage of all humankind.TCM not only embodies the cultural crystallization of the region and the nation,but also performs the important mission of curing the lives,saving the sick and maintaining the health of the people.In the history of the spread of Chinese medicine to the West,foreign missionaries have played an important role,and researches about this role have continued in China.In the history of Chinese medicine in Germany,there is a pivotal figure named Franz Hübotter(1881-1967),who broke through the deadlock in the academic research of Chinese medicine in the 19th century in Germany,but the discussion on his contribution has been comparatively rare in China.His works and translations are not only of medical value,but are also valuable historically,culturally,and socially.The historical development of TCM has the authenticity of history,the integrity of the environment,and the richness of the times.Medical experts have explored and verified the value of medicine.Translators and scholars are mainly concerned with the dissemination of knowledge from an intercultural perspective.This paper provides a primitive and objective introduction to Franz Hübotter,hoping to trigger off the secondary research among scholars of different professional backgrounds and to expand professional thinking,and then get over the barriers of disciplines.
文摘The Wiedemann–Franz(WF)law,a foundational principle in condensed matter physics,posits a direct proportionality between the electronic contributions to thermal and electrical conductivity.However,recent experimental observations,particularly in materials like vanadium dioxide(VO2),have revealed significant violations of this law.Furthermore,a growing body of evidence indicates its inapplicability under cryogenic conditions,highlighting the need for a more comprehensive theoretical framework.This study addresses this discrepancy by deriving a generalized WF law.Beginning with the thermodynamic potential of a relativistic degenerate electron gas and electron density functions,we employ a swallowtail catastrophe model grounded in structural stability principles,in conjunction with non-dimensional analysis.The resulting formulation yields a general WF law that correctly satisfies the boundary conditions at both cryogenic and infinite-temperature limits.Our findings reveal that the relationship between thermal and electrical conductivity is fundamentally nonlinear,intrinsically dependent on the material’s relaxation time and chemical potential.To validate our framework,we have applied the derived law to calculate the thermal conductivity of VO_(2),achieving excellent agreement with previously reported experimental data.This generalized WF law provides a robust theoretical tool for analyzing electron transport phenomena and holds significant potential for investigating phase transitions in metals and superconductors.
