An intensive earthquake, the Wenchuan Earthquake of 8.0 on the Richter scale, struck western Sichuan, China on May 12, 2008. The earthquake has tremendously affected all industries in the quake-hit areas, with no exce...An intensive earthquake, the Wenchuan Earthquake of 8.0 on the Richter scale, struck western Sichuan, China on May 12, 2008. The earthquake has tremendously affected all industries in the quake-hit areas, with no exception of the local tourism. The study of the effect of the earthquake on tourism enriches the theory of tourism, and more importantly, it well serves as the foundation for policy making. The objective of this study is to outline for readers the empirical findings on the various ways that the earthquake affected the operations and viability of tourism in the quake-hit areas. This paper is mainly divided into 3 parts. The first part is to discuss the importance of tourism in the quake-hit areas. The second is to analyze the influencing factors of tourism. The third is to assess the impact of the earthquake on tourism in Sichuan in different seasons.展开更多
Tropical cyclones(TCs) have a significant impact on China's Mainland.The purpose of this study is to develop an impact index which correlates with both the strong wind and heavy rainfall/flood damage caused by TCs...Tropical cyclones(TCs) have a significant impact on China's Mainland.The purpose of this study is to develop an impact index which correlates with both the strong wind and heavy rainfall/flood damage caused by TCs in China's Mainland.By considering the radius of TCs,we first define the total destructiveness index(TDI) and total column water vapor index(TVI).Economic loss is used to represent the impact of landfalling TCs.The analysis is based on 30 landfalling TCs between 2001 and 2007,and identified significant correlations between the impact of landfalling TCs and the TVI(TDI).The correlations between the impact of landfalling TCs and TVI,TDI and maximum wind speed of TCs before landfall are 0.751,0.59 and 0.345,respectively.This study also shows that landfalling TCs with a higher TVI usually bring heavier rainfall,and result in more economic losses in China.A TC impact index is defined as a function of TVI and TDI.The correlation between TC impact index and economic loss was found to be significant(r=0.769).Tropical storm Bilis in 2006 is classified as the landfalling TC with the highest impact index between 2001 and 2007 and Matsa,in 2005,as the second highest impact index in this same interval.Using a system cluster analysis method,30 landfalling TCs in this study were graded into five categories according to their impact indices.Category 5,which is the highest level,included only one TC,which constituted 4% of the total TCs studied.Category 4 included three TCs(10%).Categories 3 and 2 included seven TCs each(23%) and Category 1 included 12 TCs(40%).展开更多
This paper presents the result and analysis of the composition of energy loss occurring in the hydro turbine. Two new types of energy losses,namely the hydraulic loss in the flow channel and the impact loss,are define...This paper presents the result and analysis of the composition of energy loss occurring in the hydro turbine. Two new types of energy losses,namely the hydraulic loss in the flow channel and the impact loss,are defined. All losses within the hydro turbine are divided into four types and the loss coefficients are defined accordingly. Expressions or characteristic descriptions of these losses as well as the calibration method of the loss coefficients are presented. Furthermore,the torque model of the hydro turbine where the inner energy loss takes place is established. The developed model has been used to calculate the power loss due to the mechanical friction generated by the units’ rotation to solve the difficulty of measurements of the mechanical friction loss in the hydro turbine. The definition of the impact loss explains the phenomenon that the loss of no-load is greater than that of the rated operation. A set of conversion coefficients are defined using the characteristic parameters at the rated operation,which are used to transform the parameters in the torque model into those that are easily measured. Therefore,the expression of the hydro turbine power is converted into a function that has the main servomotor displacement as its single variable. This makes the proposed model be convenient to use. Finally,the proposed model and methods are calibrated and verified using the measured data of a hydropower plant. Good agreement between the modeled results and the measurements indicates that the proposed model can represent the inner energy loss characteristics of the hydro turbine.展开更多
No failure, moderate failure, severe failure, and slight failure are the four failure modes generalized observed in the dynamic response of the single-layer reticulated dome under vertical impact load on apex. TE (the...No failure, moderate failure, severe failure, and slight failure are the four failure modes generalized observed in the dynamic response of the single-layer reticulated dome under vertical impact load on apex. TE (the time that the end of impact force) and TF (the time that members are broken) are two key times in the failure process. Characteristics of dynamic responses at the two key times are shown in order to make the failure mechanism clear. Then three steps of energy transfer are summarized, i.e. energy applying, energy loss and energy transfer, energy consump-tion. Based on the three steps, energy transfer process for the failure reticulated dome under once impact is introduced. Energy transmissibility and local loss ratio are put forward firstly to obtain EL F(the energy left in the main reticulated dome) from the initial kinetic energy of impactor. More-over, the distribution of failure modes is decided by EL F which leads to the maximum dynamic re-sponse of the reticulated dome, but not by the initial impact kinetic energy of impactor.展开更多
基金the Second Phase of the CAS Action-plan for West Development(KZCX2-XB2-02-03-02)the National Science and Technology Supporting Program in the Eleventh Five-year Plan(No.2006BACo1A11)
文摘An intensive earthquake, the Wenchuan Earthquake of 8.0 on the Richter scale, struck western Sichuan, China on May 12, 2008. The earthquake has tremendously affected all industries in the quake-hit areas, with no exception of the local tourism. The study of the effect of the earthquake on tourism enriches the theory of tourism, and more importantly, it well serves as the foundation for policy making. The objective of this study is to outline for readers the empirical findings on the various ways that the earthquake affected the operations and viability of tourism in the quake-hit areas. This paper is mainly divided into 3 parts. The first part is to discuss the importance of tourism in the quake-hit areas. The second is to analyze the influencing factors of tourism. The third is to assess the impact of the earthquake on tourism in Sichuan in different seasons.
基金supported by National Basic Research Program of China (Grant No.2009CB421500)National Natural Science Foundation of China (Grant Nos.40975059,40921160380)
文摘Tropical cyclones(TCs) have a significant impact on China's Mainland.The purpose of this study is to develop an impact index which correlates with both the strong wind and heavy rainfall/flood damage caused by TCs in China's Mainland.By considering the radius of TCs,we first define the total destructiveness index(TDI) and total column water vapor index(TVI).Economic loss is used to represent the impact of landfalling TCs.The analysis is based on 30 landfalling TCs between 2001 and 2007,and identified significant correlations between the impact of landfalling TCs and the TVI(TDI).The correlations between the impact of landfalling TCs and TVI,TDI and maximum wind speed of TCs before landfall are 0.751,0.59 and 0.345,respectively.This study also shows that landfalling TCs with a higher TVI usually bring heavier rainfall,and result in more economic losses in China.A TC impact index is defined as a function of TVI and TDI.The correlation between TC impact index and economic loss was found to be significant(r=0.769).Tropical storm Bilis in 2006 is classified as the landfalling TC with the highest impact index between 2001 and 2007 and Matsa,in 2005,as the second highest impact index in this same interval.Using a system cluster analysis method,30 landfalling TCs in this study were graded into five categories according to their impact indices.Category 5,which is the highest level,included only one TC,which constituted 4% of the total TCs studied.Category 4 included three TCs(10%).Categories 3 and 2 included seven TCs each(23%) and Category 1 included 12 TCs(40%).
基金supported by the National Natural Science Foundation of China(Grant Nos.50839003,50949037)the Natural Science Foundation of Yunnan Province(Grant No.2008GA027)partly by the Talent Training Foundation of Kunming University of Science and Technology(Grant No.KKZ3200906019)&University of Aberdeen
文摘This paper presents the result and analysis of the composition of energy loss occurring in the hydro turbine. Two new types of energy losses,namely the hydraulic loss in the flow channel and the impact loss,are defined. All losses within the hydro turbine are divided into four types and the loss coefficients are defined accordingly. Expressions or characteristic descriptions of these losses as well as the calibration method of the loss coefficients are presented. Furthermore,the torque model of the hydro turbine where the inner energy loss takes place is established. The developed model has been used to calculate the power loss due to the mechanical friction generated by the units’ rotation to solve the difficulty of measurements of the mechanical friction loss in the hydro turbine. The definition of the impact loss explains the phenomenon that the loss of no-load is greater than that of the rated operation. A set of conversion coefficients are defined using the characteristic parameters at the rated operation,which are used to transform the parameters in the torque model into those that are easily measured. Therefore,the expression of the hydro turbine power is converted into a function that has the main servomotor displacement as its single variable. This makes the proposed model be convenient to use. Finally,the proposed model and methods are calibrated and verified using the measured data of a hydropower plant. Good agreement between the modeled results and the measurements indicates that the proposed model can represent the inner energy loss characteristics of the hydro turbine.
基金Supported by National Natural Science Foundation of China(No.90715034)
文摘No failure, moderate failure, severe failure, and slight failure are the four failure modes generalized observed in the dynamic response of the single-layer reticulated dome under vertical impact load on apex. TE (the time that the end of impact force) and TF (the time that members are broken) are two key times in the failure process. Characteristics of dynamic responses at the two key times are shown in order to make the failure mechanism clear. Then three steps of energy transfer are summarized, i.e. energy applying, energy loss and energy transfer, energy consump-tion. Based on the three steps, energy transfer process for the failure reticulated dome under once impact is introduced. Energy transmissibility and local loss ratio are put forward firstly to obtain EL F(the energy left in the main reticulated dome) from the initial kinetic energy of impactor. More-over, the distribution of failure modes is decided by EL F which leads to the maximum dynamic re-sponse of the reticulated dome, but not by the initial impact kinetic energy of impactor.
