With the quick development of urbanization, urban expansion has been paid more and more attention to by researchers from westem countries and China. Here Wuxi City of China is selected as a case study. Located in the ...With the quick development of urbanization, urban expansion has been paid more and more attention to by researchers from westem countries and China. Here Wuxi City of China is selected as a case study. Located in the core-area of Changjiang （Yangtze） River Delta, as the sources of Chinese township enterprise, Wu culture, and national industry, Wuxi has experienced great change in the urban spatial structure, especially in the land use structure, and urban shape and scale. The ratio of industrial land was about one-third of the construction land in 2003. Residential and public infrastructure land had decreased a little from 1956 to 2003, but it remains to be the main construction land at present. Green land has increased at the highest speed due to the demand of sustainable development. After the reform and opening to the outside world, this kind of evolvement of urban spatial expansion is helpful for sustainable development. Economic development, transportation, and administrative planning are the main reasons for these changes. During different periods, the main drives are different. Economic development is the basic factor that influences urban expansion. Transportation influences urban evolvement in different times, but now the importance is not as great as 30 years ago, because administrative force plays an important function in urban planning of China and influences urban evolvement.展开更多
In the beetle Goliathus cacicus, male elytra show silky luster with iridescence while female ones appear lusterless white without iridescence to our perception. We revealed by structural characterizations and optical ...In the beetle Goliathus cacicus, male elytra show silky luster with iridescence while female ones appear lusterless white without iridescence to our perception. We revealed by structural characterizations and optical measurements that elytral coloration and luster of both male and female beetles stem from the tubular scales on the elytra, whose interior is filled with a random structure. Distinct differences between male and female scales reside in the cortex thickness and the filling fraction of the random structure, which are important factors in the determination of the sexual dichromatic luster and iridescence. In additional to reflection peaks in the visible range, spectral measurements indicate that both male and female elytra display also strong iridescent ultraviolet (UV) reflections. Scattering spectra show that both male and female elytra display UV luster, although it is absent for female ones in the visible range.展开更多
In this paper, the structured trajectory planning of lane change in collision-free road environment is studied and validated using the vehicle-driver integration data, and a new trajectory planning model for lane chan...In this paper, the structured trajectory planning of lane change in collision-free road environment is studied and validated using the vehicle-driver integration data, and a new trajectory planning model for lane change is proposed based on linear offset and sine function to balance driver comfort and vehicle dynamics. The trajectory curvature of the proposed model is continuous without mutation, and the zero-based curvature at the starting and end points during lane change assures the motion direction of end points in parallel with the lane line. The field experiment are designed to collect the vehicle-driver integration data, such as steering angle, brake pedal angel and accelerator pedal angel. The correction Correlation analysis of lane-changing maneuver and influencing variables is conducted to obtain the significant variables that can be used to calibrate and test the proposed model. The results demonstrate that vehicle velocity and Y-axis acceleration have significant effects on the lane-changing maneuver, so that the model recalibrated by the samples of different velocity ranges and Y-axis accelerations has better fitted performance compared with the model calibrated by the sample trajectory. In addition, the proposed model presents a decreasing tendency of the lane change trajectory fitted MAE with the increase of time span of calibrating samples at the starting stage.展开更多
基金U nderthe auspices ofthe N ationalN aturalScience Foundation of C hina (N o.40201014)and K now ledge Innova-tion Program ofC hinese A cadem y ofSciences (N o.K ZC X 2-SW -318-03)
文摘With the quick development of urbanization, urban expansion has been paid more and more attention to by researchers from westem countries and China. Here Wuxi City of China is selected as a case study. Located in the core-area of Changjiang （Yangtze） River Delta, as the sources of Chinese township enterprise, Wu culture, and national industry, Wuxi has experienced great change in the urban spatial structure, especially in the land use structure, and urban shape and scale. The ratio of industrial land was about one-third of the construction land in 2003. Residential and public infrastructure land had decreased a little from 1956 to 2003, but it remains to be the main construction land at present. Green land has increased at the highest speed due to the demand of sustainable development. After the reform and opening to the outside world, this kind of evolvement of urban spatial expansion is helpful for sustainable development. Economic development, transportation, and administrative planning are the main reasons for these changes. During different periods, the main drives are different. Economic development is the basic factor that influences urban expansion. Transportation influences urban evolvement in different times, but now the importance is not as great as 30 years ago, because administrative force plays an important function in urban planning of China and influences urban evolvement.
基金supported by the National Basic Research Program of China (2011CB922004)supported by the National Natural Science Foundation of Chinathe Shanghai Science and Technology Commission
文摘In the beetle Goliathus cacicus, male elytra show silky luster with iridescence while female ones appear lusterless white without iridescence to our perception. We revealed by structural characterizations and optical measurements that elytral coloration and luster of both male and female beetles stem from the tubular scales on the elytra, whose interior is filled with a random structure. Distinct differences between male and female scales reside in the cortex thickness and the filling fraction of the random structure, which are important factors in the determination of the sexual dichromatic luster and iridescence. In additional to reflection peaks in the visible range, spectral measurements indicate that both male and female elytra display also strong iridescent ultraviolet (UV) reflections. Scattering spectra show that both male and female elytra display UV luster, although it is absent for female ones in the visible range.
基金supported by the National Natural Science Foundation of China(Grant No.61473028)the National Basic Research Program of China("973" Program)(Grant No.2012CB725403)the National High Technology Research and Development Program of China("863" Program)(Grant No.2015AA124103)
文摘In this paper, the structured trajectory planning of lane change in collision-free road environment is studied and validated using the vehicle-driver integration data, and a new trajectory planning model for lane change is proposed based on linear offset and sine function to balance driver comfort and vehicle dynamics. The trajectory curvature of the proposed model is continuous without mutation, and the zero-based curvature at the starting and end points during lane change assures the motion direction of end points in parallel with the lane line. The field experiment are designed to collect the vehicle-driver integration data, such as steering angle, brake pedal angel and accelerator pedal angel. The correction Correlation analysis of lane-changing maneuver and influencing variables is conducted to obtain the significant variables that can be used to calibrate and test the proposed model. The results demonstrate that vehicle velocity and Y-axis acceleration have significant effects on the lane-changing maneuver, so that the model recalibrated by the samples of different velocity ranges and Y-axis accelerations has better fitted performance compared with the model calibrated by the sample trajectory. In addition, the proposed model presents a decreasing tendency of the lane change trajectory fitted MAE with the increase of time span of calibrating samples at the starting stage.
