To advance hierarchical equations of motion as a standard theory for quantum dissipative dynamics, we put forward a mixed Heisenberg-SchrSdinger scheme with block-matrix implementation on efficient evaluation of nonli...To advance hierarchical equations of motion as a standard theory for quantum dissipative dynamics, we put forward a mixed Heisenberg-SchrSdinger scheme with block-matrix implementation on efficient evaluation of nonlinear optical response function. The new approach is also integrated with optimized hierarchical theory and numerical filtering algorithm. Different configurations of coherent two-dimensional spectroscopy of model excitonic dimer systems are investigated, with focusing on the effects of intermolecular transfer coupling and bi-exciton interaction.展开更多
Mountain forests are managed for various purposes. Of these, recreation, leisure, and ecotourism are increasingly gaining prominence. Yet, with the development of new techniques for creating and managing urban forests...Mountain forests are managed for various purposes. Of these, recreation, leisure, and ecotourism are increasingly gaining prominence. Yet, with the development of new techniques for creating and managing urban forests, the perception of the public with regard to mountain forests and such urban forests is narrowing. For the purpose of this study, eight mountain forests and urban forests located in Zurich(Switzerland), Vienna(Austria) and Freiburg(Germany) were shortlisted. These places are renowned for their well-functioning management of mountain forests and creation of urban forests. As the study was to focus on the comparison of the perceptions of visitors in terms of their satisfaction in urban and mountain forests, the interview covered the following questions:(i) how satisfactory was the nature experience;(ii) how satisfactory were the outdoor recreational activities;(iii) whether the nature experiences influenced the mental and physical health of visitors. Responses thus received for each of the mountain forests and urban forests were assessed, with the total number of respondents being 247. Tourists visiting the selected areas were randomly chosen for a one-on-one interview survey. Results of the survey show that there is a clear perceptions of visitors differed between urban and mountain forests. However, the gap is insignificant or almost nonexistent with respect to satisfaction level of outdoor recreational activities and health benefits. These results are contrary to the findings of previous studies, which argued that the natural landscape of mountain areas is superior to other artificially built green spaces. Visitors did not perceive significant differences in outdoor recreational activities and health effects between the two spaces.展开更多
In the present paper, we investigate the quantum phase transition in a spatially anisotropic antiferrornagnetic Heisenberg model of S =1 with single-ion energy anisotropy. By using the Schwinger boson representation, ...In the present paper, we investigate the quantum phase transition in a spatially anisotropic antiferrornagnetic Heisenberg model of S =1 with single-ion energy anisotropy. By using the Schwinger boson representation, we calculate the Gaussian correction to the critical value J⊥^c caused by quantum spin fluctuations. We find that, for the positive single-ion energy, a nonzero value of J⊥^c is always needed to stabilize the antiferromagnetic long-range order in this model. It resolves a difference among literature and shows clearly that the effect of quantum fluctuations may qualitatively change a result obtained by the mean-field theories on lower-dimensional systems.展开更多
Santa Barbara castle is one of the largest fortified complexes of the Spanish Mediterranean coast. Set in a strategic enclave in the city of Alicante. It has been transformed over the centuries since its origin, so th...Santa Barbara castle is one of the largest fortified complexes of the Spanish Mediterranean coast. Set in a strategic enclave in the city of Alicante. It has been transformed over the centuries since its origin, so that nowadays includes numerous buildings inside its area. The fortified area contains several lines bastioned and some medieval and Muslim fronts, composed of quadrangular towers. During the years 2007 and 2008, a research team composed of members from the University of Alicante, the University of Burgos and the Polytechnic University of Catalonia has developed a study on the conservation status of the Castle. This study has been funded through research grants from thc Genemlitat Valenciana （Project GV reference 2007/150）, and an agreement with Manuel PeIAez Foundation. We have generated a 3D object of the whole, composed by clouds of millions points, through laser-scanner in order to manage the analysis of the architectural element＇s conservation status that make up the huge fortified complex. This tool reduced greatly the architectural survey work, providing an extremely accurate. They were developed through the program Pointools View, generating JPEG files, which were imported from Autocad. Later we undertook a comprehensive making of photos -- some 7,000 photographs, which we linked to the 3D object. Thus we have immediate access to the photographs of each element of the Castle from the program Pointools View with a simple click on each 3D element. The graphic representation of damages was done on screen with programs Pointools View and Autocad open simultaneously. This technique has meant better accuracy in the study of conservation status and has greatly reduced the time commitment.展开更多
基金This work was supported by the National Natural Science Foundation of China （No.21033008 and No.21073169）the National Basic Research Program of China （No.2010CB923300 and No.2011CB921400）and the Hong Kong RGC （No.604709） and UGC （AoE/P04/08-2） is gratefully acknowledged.
文摘To advance hierarchical equations of motion as a standard theory for quantum dissipative dynamics, we put forward a mixed Heisenberg-SchrSdinger scheme with block-matrix implementation on efficient evaluation of nonlinear optical response function. The new approach is also integrated with optimized hierarchical theory and numerical filtering algorithm. Different configurations of coherent two-dimensional spectroscopy of model excitonic dimer systems are investigated, with focusing on the effects of intermolecular transfer coupling and bi-exciton interaction.
基金supported by the 2012 Yeungnam University Research Grant
文摘Mountain forests are managed for various purposes. Of these, recreation, leisure, and ecotourism are increasingly gaining prominence. Yet, with the development of new techniques for creating and managing urban forests, the perception of the public with regard to mountain forests and such urban forests is narrowing. For the purpose of this study, eight mountain forests and urban forests located in Zurich(Switzerland), Vienna(Austria) and Freiburg(Germany) were shortlisted. These places are renowned for their well-functioning management of mountain forests and creation of urban forests. As the study was to focus on the comparison of the perceptions of visitors in terms of their satisfaction in urban and mountain forests, the interview covered the following questions:(i) how satisfactory was the nature experience;(ii) how satisfactory were the outdoor recreational activities;(iii) whether the nature experiences influenced the mental and physical health of visitors. Responses thus received for each of the mountain forests and urban forests were assessed, with the total number of respondents being 247. Tourists visiting the selected areas were randomly chosen for a one-on-one interview survey. Results of the survey show that there is a clear perceptions of visitors differed between urban and mountain forests. However, the gap is insignificant or almost nonexistent with respect to satisfaction level of outdoor recreational activities and health benefits. These results are contrary to the findings of previous studies, which argued that the natural landscape of mountain areas is superior to other artificially built green spaces. Visitors did not perceive significant differences in outdoor recreational activities and health effects between the two spaces.
基金The project partially supported by National Natural Science Foundation of China under Grant No. 90403003 We thank Prof. Xiao-Qun Wang and Prof. Tao Li for useful discussions. Numerical computation of this work was carried out on the Parallel Computer Cluster of Insti- tute for Condensed Matter Physics （ICMP） at School of Physics, Peking University.
文摘In the present paper, we investigate the quantum phase transition in a spatially anisotropic antiferrornagnetic Heisenberg model of S =1 with single-ion energy anisotropy. By using the Schwinger boson representation, we calculate the Gaussian correction to the critical value J⊥^c caused by quantum spin fluctuations. We find that, for the positive single-ion energy, a nonzero value of J⊥^c is always needed to stabilize the antiferromagnetic long-range order in this model. It resolves a difference among literature and shows clearly that the effect of quantum fluctuations may qualitatively change a result obtained by the mean-field theories on lower-dimensional systems.
文摘Santa Barbara castle is one of the largest fortified complexes of the Spanish Mediterranean coast. Set in a strategic enclave in the city of Alicante. It has been transformed over the centuries since its origin, so that nowadays includes numerous buildings inside its area. The fortified area contains several lines bastioned and some medieval and Muslim fronts, composed of quadrangular towers. During the years 2007 and 2008, a research team composed of members from the University of Alicante, the University of Burgos and the Polytechnic University of Catalonia has developed a study on the conservation status of the Castle. This study has been funded through research grants from thc Genemlitat Valenciana （Project GV reference 2007/150）, and an agreement with Manuel PeIAez Foundation. We have generated a 3D object of the whole, composed by clouds of millions points, through laser-scanner in order to manage the analysis of the architectural element＇s conservation status that make up the huge fortified complex. This tool reduced greatly the architectural survey work, providing an extremely accurate. They were developed through the program Pointools View, generating JPEG files, which were imported from Autocad. Later we undertook a comprehensive making of photos -- some 7,000 photographs, which we linked to the 3D object. Thus we have immediate access to the photographs of each element of the Castle from the program Pointools View with a simple click on each 3D element. The graphic representation of damages was done on screen with programs Pointools View and Autocad open simultaneously. This technique has meant better accuracy in the study of conservation status and has greatly reduced the time commitment.
