China is in the process of rapid urbanization,and wise land use is critical to the long-term sustainability of Chinese cities.Promotion of a compact city is typically believed to be helpful for sustainable land use ma...China is in the process of rapid urbanization,and wise land use is critical to the long-term sustainability of Chinese cities.Promotion of a compact city is typically believed to be helpful for sustainable land use management.However,given the fact that Chinese cities are characterized by high population densities,the applicability of a more compact solution to expand cities in China remains questionable;there is little evidence to support the many claims in its favor.In seeking to provide empirical data to explore the application of compact city theory in China,one of the key problems researchers face is the task of measuring the urban compactness,in order to objectively investigate the current characteristics of urban compactness.To meet this need,indices were developed for measuring the urban land use compactness,by which the spatial distribution characteristics of urban land use compactness were identified and applied to the Chaoyang District of Beijing.The conclusions can be made as follows:(1) comprehensive land use compactness in Chaoyang District has increased during the period of 2001-2007,especially the population density;(2) the spatial distribution of land use compactness has the characteristics of a ring structure,which shows a decreasing trend with its distance to the city center;(3) there is a strong positive correlation between urban land use compactness and location.The better the location is,the higher the land use compactness is.展开更多
The wavelength modulation indices are measured based on harmonic amplitude ratio of 4famp/6famp (4famp and 6famp are the 4- and 6-th harmonic central peak amplitudes correspondingly) with the Doppler-free selective re...The wavelength modulation indices are measured based on harmonic amplitude ratio of 4famp/6famp (4famp and 6famp are the 4- and 6-th harmonic central peak amplitudes correspondingly) with the Doppler-free selective reflection modulation spectroscopy. The experiments for the 6S1/2(F = 4) → 6P3/2(F' = 5) transition of cesium D2 line with 30-MHz linewidth were carried out. The 4f- and 6f-harmonic signals were detected with two digital lock-in amplifiers separately. The maximum error for modulation indices measurement was ±0.1 within the range of m from 3 to 6. The non-linear modulation behaviour of an external cavity diode laser induced by voltage tuning was studied with this method. The method for modulation indices measurement does not require a solid etalon as usual for measuring the wavelength modulation depth and the absorption linewidth correspondingly.展开更多
As China will change from a large industrial power into a strong industrial power in the 21stcentury, theinevitabledemand isfor industrialmodernization. Thispaperputs forward three criteria for judging the degree of r...As China will change from a large industrial power into a strong industrial power in the 21stcentury, theinevitabledemand isfor industrialmodernization. Thispaperputs forward three criteria for judging the degree of realization of industrialmodernization: industrial growth efficiency, industrial structure and industrial environment. Together with these, it constructsan indicatorsystem and indicesforevaluating thelevelofindustrialmodernization, and uses this indicator system to evaluate the level of China’s industrial modernization at theturn ofthecentury. TheresultingcomprehensiveindexofChina’sindustrialmodernization is28.72. This indicatesthat, through the rapid industrialization which hastaken place over more than 20 years of reform and opening up, China has commenced its industrial modernization, which is now in the primarystage of development. Thecore of thestrategy forfurther development should be to accelerate the process of industrial modernization.展开更多
基金financed by the National Natural Science Foundation of China(Grant nos.40635026and40901068)Special Fund from the Science and Technology Department of Beijing Municipality(Grant no.zz0922)the Postdoctoral Science Foundation of China(Grant no.200902133)
文摘China is in the process of rapid urbanization,and wise land use is critical to the long-term sustainability of Chinese cities.Promotion of a compact city is typically believed to be helpful for sustainable land use management.However,given the fact that Chinese cities are characterized by high population densities,the applicability of a more compact solution to expand cities in China remains questionable;there is little evidence to support the many claims in its favor.In seeking to provide empirical data to explore the application of compact city theory in China,one of the key problems researchers face is the task of measuring the urban compactness,in order to objectively investigate the current characteristics of urban compactness.To meet this need,indices were developed for measuring the urban land use compactness,by which the spatial distribution characteristics of urban land use compactness were identified and applied to the Chaoyang District of Beijing.The conclusions can be made as follows:(1) comprehensive land use compactness in Chaoyang District has increased during the period of 2001-2007,especially the population density;(2) the spatial distribution of land use compactness has the characteristics of a ring structure,which shows a decreasing trend with its distance to the city center;(3) there is a strong positive correlation between urban land use compactness and location.The better the location is,the higher the land use compactness is.
基金This work was supported in part by the National Natural Science Foundation of China (Grant No. 10174047, 60078009) Natural Science Foundation of Shanxi Province.
文摘The wavelength modulation indices are measured based on harmonic amplitude ratio of 4famp/6famp (4famp and 6famp are the 4- and 6-th harmonic central peak amplitudes correspondingly) with the Doppler-free selective reflection modulation spectroscopy. The experiments for the 6S1/2(F = 4) → 6P3/2(F' = 5) transition of cesium D2 line with 30-MHz linewidth were carried out. The 4f- and 6f-harmonic signals were detected with two digital lock-in amplifiers separately. The maximum error for modulation indices measurement was ±0.1 within the range of m from 3 to 6. The non-linear modulation behaviour of an external cavity diode laser induced by voltage tuning was studied with this method. The method for modulation indices measurement does not require a solid etalon as usual for measuring the wavelength modulation depth and the absorption linewidth correspondingly.
基金The paper is based on the word under the Chinese Academy of Social Sciences major research projict "Strdy of the Interaction of Industrialization , Industrialization and Industrial Modernization"
文摘As China will change from a large industrial power into a strong industrial power in the 21stcentury, theinevitabledemand isfor industrialmodernization. Thispaperputs forward three criteria for judging the degree of realization of industrialmodernization: industrial growth efficiency, industrial structure and industrial environment. Together with these, it constructsan indicatorsystem and indicesforevaluating thelevelofindustrialmodernization, and uses this indicator system to evaluate the level of China’s industrial modernization at theturn ofthecentury. TheresultingcomprehensiveindexofChina’sindustrialmodernization is28.72. This indicatesthat, through the rapid industrialization which hastaken place over more than 20 years of reform and opening up, China has commenced its industrial modernization, which is now in the primarystage of development. Thecore of thestrategy forfurther development should be to accelerate the process of industrial modernization.
