Symmetrical quasi-classical （SQC） method based on mapping Hamiltonian is an efficient approach that is potentially useful to treat the nonadiabatic dynamics of very large systems. We try to evaluate the performance ...Symmetrical quasi-classical （SQC） method based on mapping Hamiltonian is an efficient approach that is potentially useful to treat the nonadiabatic dynamics of very large systems. We try to evaluate the performance of this method in the ultrafast electron transfer processes involving a few of electronic states and a large number of vibrational modes. The multilayer multiconfigurational time-dependent Hartree （ML-MCTDH） method was used to get the accurate dynamical results for benchmark. Although the population dynamics in the long- time limit show differences in the ML-MCTDH and SQC calculations, the SQC method gives acceptable results.展开更多
METASTATIC gastric tumors are clinically uncommon,and metastatic gastric cancer from breast cancer was rarely reported.Here we report a case of gastric metastasis of atypical medullary carcinoma from breast.
Around two thirds of the Swedish rural areas experienced positive net migration during the period 2003-2005. This paper examines the development in the Swedish rural areas from the perspective of the ＂new rurality＂ ...Around two thirds of the Swedish rural areas experienced positive net migration during the period 2003-2005. This paper examines the development in the Swedish rural areas from the perspective of the ＂new rurality＂ or the new rural economic order with regard to migratory movements. The paper analyzes determinants of net migration to rural areas in general and to different types of regions, and the impacts of in-migration on rural labor markets, self-employment and other socio-economic conditions. The determinants of the migration pattern were mainly the size of adjacent local and regional centers, income and education levels that all had positive impacts, while commuting distance and unemployment rate had contrary effects. In comparison with the original inhabitants, the newcomers had lower incomes, a lower employment ratio and a lower degree of entrepreneurial activities, but higher education levels. These differences might be explained by the age differences between stayers （older） and in-migrants （younger）. This indicates that the two groups were in different stages of their life cycles. One central conclusion drawn from the paper is that the effect of in-migration on the composition of the rural population is about the same in rural areas all over Sweden.展开更多
Athens, a metropolis characterized by agglutination and compactness, but at the same time facing numerous urban and transport issues, saw its population swell during the 20th century which led to extensive urbanizatio...Athens, a metropolis characterized by agglutination and compactness, but at the same time facing numerous urban and transport issues, saw its population swell during the 20th century which led to extensive urbanization phenomena. This continued urbanization increases profoundly all urban activities with transportation being the key driver in energy consumption. Theories for sustainable cities prerequisite are the integration of a number of acts in order to reduce energy consumption, with mobility being the first consideration among others. The aim of this paper is to critically explore implemented policies and plans as well as forthcoming strategic plans in terms of sustainable mobility as imposed in large scale regeneration plans in contemporary Athens. Research focuses on strategic interventions since the 1980s, such as the Athenian Daktylios （ring road for circulation management） and its later adjustments, the upcoming pedestrianization and unification of the commercial triangle and its subsequent tram line extension as well as the notable implementation of the metropolitan cycling network. Moreover, the discussion takes into consideration the implications of the Greek economic crisis in mobility choices, as aimless travels have been reduced to a minimum, several cars have been abandoned and cyclists seem to tentatively claim some space in the urban environment. What will likely be the next day in the Athenian historic centre？ Considering the transformations that are expected in the immediate future, this research paper explores their potential to enhance urban environment, reduce climate change impacts and amplify resilience.展开更多
The semiclassical limit in the transient quantum drift-diffusion equations with isentropic pressure in one space dimension is rigorously proved. The equations are supplemented with homogeneous Neumann boundary conditi...The semiclassical limit in the transient quantum drift-diffusion equations with isentropic pressure in one space dimension is rigorously proved. The equations are supplemented with homogeneous Neumann boundary conditions. It is shown that the semiclassical limit of this solution solves the classical drift-diffusion model. In the meanwhile, the global existence of weak solutions is proved.展开更多
By recording nocturnally migrating passerines with tracking radar we have investigated how coastlines affect the migrants＇ flight paths. Birds could use coastlines as an orientation aid or as a reference cue to compe...By recording nocturnally migrating passerines with tracking radar we have investigated how coastlines affect the migrants＇ flight paths. Birds could use coastlines as an orientation aid or as a reference cue to compensate for wind drift while mi- grating. However, on the small scale of Falsterbo Peninsula in southern Sweden, we found very little effect of coastlines on migrants flight paths, irrespective of altitude. We tracked 2 930 migrants in three autumn and two spring seasons, at altitudes from 60 up to 3 000 meters. We compared tracks of migrants flying in three different areas, which correspond to the three main coastlines, and can demonstrate that the orientation of the tracks did not differ in a way consistent with the coastlines between the areas in autumn, and showed only a slight effect in spring. This is in accordance with earlier infrared device monitoring in Falsterbo, but contrary to earlier visual observations. It supports the view of nocturnally migrating passerines as mainly broad-front migrants. Even though the coastlines on the scale of the peninsula affected the flight paths very little, it is possible that the coastline has an effect on a larger regional scale, by migrants avoiding long sea crossings and thereby being funneled towards the peninsula, but this remains to be investigated [Current Zoology 60 （5）： 660-669, 2014].展开更多
文摘Symmetrical quasi-classical （SQC） method based on mapping Hamiltonian is an efficient approach that is potentially useful to treat the nonadiabatic dynamics of very large systems. We try to evaluate the performance of this method in the ultrafast electron transfer processes involving a few of electronic states and a large number of vibrational modes. The multilayer multiconfigurational time-dependent Hartree （ML-MCTDH） method was used to get the accurate dynamical results for benchmark. Although the population dynamics in the long- time limit show differences in the ML-MCTDH and SQC calculations, the SQC method gives acceptable results.
文摘METASTATIC gastric tumors are clinically uncommon,and metastatic gastric cancer from breast cancer was rarely reported.Here we report a case of gastric metastasis of atypical medullary carcinoma from breast.
文摘Around two thirds of the Swedish rural areas experienced positive net migration during the period 2003-2005. This paper examines the development in the Swedish rural areas from the perspective of the ＂new rurality＂ or the new rural economic order with regard to migratory movements. The paper analyzes determinants of net migration to rural areas in general and to different types of regions, and the impacts of in-migration on rural labor markets, self-employment and other socio-economic conditions. The determinants of the migration pattern were mainly the size of adjacent local and regional centers, income and education levels that all had positive impacts, while commuting distance and unemployment rate had contrary effects. In comparison with the original inhabitants, the newcomers had lower incomes, a lower employment ratio and a lower degree of entrepreneurial activities, but higher education levels. These differences might be explained by the age differences between stayers （older） and in-migrants （younger）. This indicates that the two groups were in different stages of their life cycles. One central conclusion drawn from the paper is that the effect of in-migration on the composition of the rural population is about the same in rural areas all over Sweden.
文摘Athens, a metropolis characterized by agglutination and compactness, but at the same time facing numerous urban and transport issues, saw its population swell during the 20th century which led to extensive urbanization phenomena. This continued urbanization increases profoundly all urban activities with transportation being the key driver in energy consumption. Theories for sustainable cities prerequisite are the integration of a number of acts in order to reduce energy consumption, with mobility being the first consideration among others. The aim of this paper is to critically explore implemented policies and plans as well as forthcoming strategic plans in terms of sustainable mobility as imposed in large scale regeneration plans in contemporary Athens. Research focuses on strategic interventions since the 1980s, such as the Athenian Daktylios （ring road for circulation management） and its later adjustments, the upcoming pedestrianization and unification of the commercial triangle and its subsequent tram line extension as well as the notable implementation of the metropolitan cycling network. Moreover, the discussion takes into consideration the implications of the Greek economic crisis in mobility choices, as aimless travels have been reduced to a minimum, several cars have been abandoned and cyclists seem to tentatively claim some space in the urban environment. What will likely be the next day in the Athenian historic centre？ Considering the transformations that are expected in the immediate future, this research paper explores their potential to enhance urban environment, reduce climate change impacts and amplify resilience.
基金the National Natural Science Foundation of China(Nos.10401019,10701011,10541001)
文摘The semiclassical limit in the transient quantum drift-diffusion equations with isentropic pressure in one space dimension is rigorously proved. The equations are supplemented with homogeneous Neumann boundary conditions. It is shown that the semiclassical limit of this solution solves the classical drift-diffusion model. In the meanwhile, the global existence of weak solutions is proved.
文摘By recording nocturnally migrating passerines with tracking radar we have investigated how coastlines affect the migrants＇ flight paths. Birds could use coastlines as an orientation aid or as a reference cue to compensate for wind drift while mi- grating. However, on the small scale of Falsterbo Peninsula in southern Sweden, we found very little effect of coastlines on migrants flight paths, irrespective of altitude. We tracked 2 930 migrants in three autumn and two spring seasons, at altitudes from 60 up to 3 000 meters. We compared tracks of migrants flying in three different areas, which correspond to the three main coastlines, and can demonstrate that the orientation of the tracks did not differ in a way consistent with the coastlines between the areas in autumn, and showed only a slight effect in spring. This is in accordance with earlier infrared device monitoring in Falsterbo, but contrary to earlier visual observations. It supports the view of nocturnally migrating passerines as mainly broad-front migrants. Even though the coastlines on the scale of the peninsula affected the flight paths very little, it is possible that the coastline has an effect on a larger regional scale, by migrants avoiding long sea crossings and thereby being funneled towards the peninsula, but this remains to be investigated [Current Zoology 60 （5）： 660-669, 2014].
