According to the statistical data in the years 2004-2008,both Shift-Share Analysis and Location Quotient Analysis are used to compare the economic development status of counties(districts)in Dingxi City in the years 2...According to the statistical data in the years 2004-2008,both Shift-Share Analysis and Location Quotient Analysis are used to compare the economic development status of counties(districts)in Dingxi City in the years 2004 and 2008.Advantages and disadvantages of industrial structure and competitiveness are analyzed,as well as the impacts of existing industrial structure on economic growth.Development direction and development focus of primary,secondary and tertiary industries are found out.Countermeasures for accelerating the economic development of counties(districts)in Dingxi City are put forward,such as increasing the inputs in characteristic agriculture,promoting the development of primary industry,speeding up the construction of large and medium industrial enterprises,enhancing the development of secondary industry,strengthening comprehensive environmental improvement in tourist area,and actively developing tertiary industry.展开更多
Recreational Ecosystem Services(RES)are among the most frequently evaluated ecosystem services.RES are seen as a major opportunity for sustainable development in areas of high ecological value resulting from the prese...Recreational Ecosystem Services(RES)are among the most frequently evaluated ecosystem services.RES are seen as a major opportunity for sustainable development in areas of high ecological value resulting from the presence of emblematic species,habitats or scenery,often integrated in conservation areas,in particular in mountain areas affected by depopulation,rising environmental risks and poverty.Economically,the assessment of RES has been based on Contingent Valuation and Choice Experiments,methods with limitations related to their subjectivity.Alternatively,Input-Output(IO)models provide a very accurate and effective way of valuation of RES with regional information regarding interindustry transactions.Whilst data on nature tourist expenditure may be only available annually,tourism inflows have a strong seasonal behavior,which impacts the profitability of several local economic activities.In this paper,we firstly constructed a novel regionalized IO-model based on Cross-Industry Location Quotients using employment data and,secondly,based on Monte Carlo simulation,we estimated nature tourist expenditure monthly using data on nature tourism inflows.This method allowed for a more precise RES evaluation,estimating direct,indirect and induced monthly economic impacts of nature-based tourism.The method was applied to the Ordesa and Monte Perdido(OMP)National Park in the Spanish Pyrenees.To estimate the average tourist expenditure,we collected and analyzed spending on commerce,hospitality and restaurants,leisure,and transport of 385 visitors.Results suggest that using a regionalized IO model leads to a considerable reduction of over-estimation of the economic impact of tourist expenditure estimated by conventional methods.Taking into consideration the direct,indirect and induced effects of tourist expenditure in 2016-2018,the total annual output effect in the OMP National Park amounted to€208.8 million,while the total income effect amounted to€86.29 million.Also,a total of 2,429 jobs were created which indicates that for each thousand annual visitors to the National Park,3.8 jobs are created in the surrounding area.Overall,the proposed methodology can be easily applied to the remaining National Parks in Spain or other regions in the world,making it a valuable tool to estimate the value of RES in areas affects by strong seasonality,to set priorities and support regional policies for mountain sustainable development.展开更多
Using data from the Economic Advisory Center of the State Information Center(SIC), we examined the spatial patterns of car sales in China at the prefectural level in 2012. We first analyzed the spatial distributions o...Using data from the Economic Advisory Center of the State Information Center(SIC), we examined the spatial patterns of car sales in China at the prefectural level in 2012. We first analyzed the spatial distributions of car sales of different kinds of automakers(foreign automakers, Sino-foreign joint automakers, and Chinese automakers), and then identified spatial clusters using the local Moran's indexes. Location quotient analysis was applied to examine the relative advantage of each type of automaker in the local markets. To explain the variations of car sales across cities, we collected several socioeconomic variables and conducted regression analyses. Further, factor analysis was used to extract independent variables to avoid the problem of multicollinearity. By incorporating a spatial lag or spatial error in the models, we calibrated our spatial regression models to address the spatial dependence problem. The analytical results show that car sales varied significantly across cities in China, and most of the cities with higher car sales were the developed cities. Different automakers exhibit diverse spatial patterns in terms of car sales volume, spatial clusters, and location quotients. The scale and incomes factor were extracted and verified as the two most significant and positive factors that shape the spatial distributions of car sales, and together with the spatial effect, explained most of the variations of car sales across cities.展开更多
Taking Chongzuo City of Guangxi Zhuang Autonomous Region as an example, the employment effect of the resource-abundant industrial cluster in southwestern Guangxi Province is analyzed according to the data from the Cho...Taking Chongzuo City of Guangxi Zhuang Autonomous Region as an example, the employment effect of the resource-abundant industrial cluster in southwestern Guangxi Province is analyzed according to the data from the Chongzuo Statistical Yearbook , Guangxi Statistical Yearbook from 2003 to 2008 and the data from the relevant sections of Chongzuo City, and the four employment effects of industrial cluster--the spatial expansion effect of employment chain, optimizing effect of employment structure, the multiplier effect of employment absorption and the effect of improving the quality of labors and the degree of the intensity of employment and location quotient of employment. Results show that the employment absorption of sugar industry in Chongzuo City is stable and upward slightly, and it shows strong employment effect; the sugar industry in Chongzuo is not only competitive, but also has a great share of market in employment, so it owns strong absorption of employment. The countermeasures for improving the employment level of resource-abundant and industrial cluster in southwest of Guangxi Province are put forward, including elongating industrial chain and widening employment space; strengthening various kinds of formal and informal training to improve the employment capability of laborers; laying stress on industrial structure and optimizing the employment structure; strengthening the construction of the industrial economic zone towards ASEAN(Association of Southeast Asian Nations), and fully displaying the regional advantages of the offshore border.展开更多
Based on introducing the basic conditions of the ethnic regions in northwest Sichuan Province,the thesis analyzes its agricultural development status,which can be classified into two aspects--rich natural resources an...Based on introducing the basic conditions of the ethnic regions in northwest Sichuan Province,the thesis analyzes its agricultural development status,which can be classified into two aspects--rich natural resources and slow agricultural economic growth.Through the analysis on the agricultural structure of northwest Sichuan Province,it is found that the production efficiency and economic benefits of crop planting in this region are low,animal husbandry,as a major industry in pastoral region,sees high production efficiency,the agricultural production is still at the resource-oriented stage;its agricultural structure is still the farming-pastoral structure relying mainly on animal husbandry,planting is dominated by crop planting and potato planting,animal husbandry mainly produces dairy and beef;the ethnic regions in northwest Sichuan Province is endowed with the advantages to grow crops,beans and fruits as well as to produce beef,mutton and milk,among which,three industries,say fruit,beef and dairy are with increasing location quotient and gradually strengthening industrial comparative advantage,while the location quotient of the other industries is declining and their industrial comparative advantages are more stable.In order to promote the agriculture in northwest Sichuan Province to develop in breadth and depth,the thesis proposes the following measures and suggestions:the first one is to adhere to the development strategy of modern animal husbandry;the second is to appropriately improve the proportion of economic crops;the third is to accelerate the development of green food processing industry.展开更多
On the basis of input-output table of Henan Province and China in 2007,this paper advances a simple method of constructing two-region input-output model using MRIO model,to research the economic link between the indus...On the basis of input-output table of Henan Province and China in 2007,this paper advances a simple method of constructing two-region input-output model using MRIO model,to research the economic link between the industries of Henan Province and the industries of other regions.I summarize the characteristics of this method based on this as follows:when researching inter-regional economic link,the multi-region or two-region input-output model has prominent superiority,and we can conduct preliminary estimation on the multi-region input-output model using location quotient approach.展开更多
Firstly,agriculture,industry and tourism in the Yangtze River Delta,Pearl River Delta and Bohai Economic Rim were chosen to represent the primary,secondary and tertiary industries respectively,and industrial agglomera...Firstly,agriculture,industry and tourism in the Yangtze River Delta,Pearl River Delta and Bohai Economic Rim were chosen to represent the primary,secondary and tertiary industries respectively,and industrial agglomeration in the three economic zones was analyzed using location quotient coefficient method.Afterwards,the critical factors influencing industrial agglomeration were discussed using gray correlation analysis.The results showed that industrial agglomeration of agriculture,industry and tourism formed gradually in the three economic zones,and the critical factors influencing industrial agglomeration were human capital,science and technology progress,and natural resources.Meanwhile,environmental pollution affected and restricted the development of industrial agglomeration.展开更多
On the basis of analyzing yearly data and spatial relationships between tourism spots, star hotels and travel agencies of Hainan Province, and comparing all the methods of measuring industrial spatial agglomeration, t...On the basis of analyzing yearly data and spatial relationships between tourism spots, star hotels and travel agencies of Hainan Province, and comparing all the methods of measuring industrial spatial agglomeration, this paper chose Hefindahl index, Location Quotient, nearest neighbor index, spatial connection index and geographic concentration index to measure Hainan tourism agglomeration. By applying these methods, total tourism agglomeration, agglomeration of tourism factors and regional agglomeration differences were studied. The results showed that the overall agglomeration increases as time flows, and the eastern part is the most agglomerated, the west takes the second, with the middle ranking the least. The large-scale agglomeration regions are Sanya and Haikou. The influencing factors of Hainan tourism spatial agglomeration were concluded as tourism resource endowment, industrial attributes, geographic conditions, governmental policies and the overall economic development level, etc. In addition, the paper proposed tourism spatial agglomeration modes of Hainan Province at various spatial scales.展开更多
In order to study the development status of kelp industry in Rongcheng in recent years, the centralization degree of kelp industry clusters and the comparative advantage of kelp industry in Rongcheng, Xiapu and Jinpu ...In order to study the development status of kelp industry in Rongcheng in recent years, the centralization degree of kelp industry clusters and the comparative advantage of kelp industry in Rongcheng, Xiapu and Jinpu from 2010 to 2020 were compared and analyzed by indicators such as location quotient index, industrial agglomeration index, coefficient of concentration, scale advantage index, efficiency advantage index, and comprehensive advantage index, and the deep-seated factors affecting the competitiveness of kelp industry in Rongcheng were analyzed. Meanwhile, measures of improving the competitiveness of the kelp industry cluster in Rongcheng were put forward.展开更多
Based on the 16 central cities＇ Panel Data in Yangtze River Delta, location quotient index is used in this paper to measure and analyze the current cluster situation of producer services in Yangtze River Delta, fixed...Based on the 16 central cities＇ Panel Data in Yangtze River Delta, location quotient index is used in this paper to measure and analyze the current cluster situation of producer services in Yangtze River Delta, fixed effects model of Panel Data model is also used in this paper, and the industrial structure is taken as the dependent variable, while the core explanatory variables is the degree of producer services＇ cluster development, which is calculated by location quotient, moreover, three control variables introduced in this paper and they are technology advantage, education level and R＆D spending, and the mentioned above is to empirically study the impacts of producer services＇ cluster development to the regional industrial structure. As a result, producer services＇ cluster development has a significant positive role in promoting the regional industrial structure optimization and upgrading, though the extent is not yet a big push and is still to be further strengthened. In this paper, it has provided a strong evidence that under China＇ s new normal economy, producer services is badly needed to promote regional industrial structure, and finally it makes specific suggestions based on the current cluster situation of producer services in Yangtze River Delta.展开更多
In order to achieve the model-based fault monitoring and diagnosis,an accurate model for the rotor system is necessary to locate and quantify faults.Since the dynamic characteristics of a blade-rotor system is influen...In order to achieve the model-based fault monitoring and diagnosis,an accurate model for the rotor system is necessary to locate and quantify faults.Since the dynamic characteristics of a blade-rotor system is influenced by foundation flexibility,the modeling and dynamic analyses on the foundation were sequentially investigated.Firstly,the effect of element size on the model convergence was investigated using the forward difference quotient as the slope of the frequency difference,which found that the model converged when the element size refined to 4mm.Secondly,a modal analysis and a harmonic response analysis were performed to obtain the dynamic characteristics of the foundation structure.Finally,an optimization to the foundation utilizing an additional stiffener was conducted to reduce the foundation response and make the critical speed far away from the working frequency band of 20—50Hz.展开更多
China's requisition-compensation balance strategy has dramatically reshaped cropland spatial patterns,drawing multidisciplinary research attention.However,existing studies predominantly emphasize horizontal distri...China's requisition-compensation balance strategy has dramatically reshaped cropland spatial patterns,drawing multidisciplinary research attention.However,existing studies predominantly emphasize horizontal distribution,overlooking the significant influence of slope gradient on cropland spatial patterns.This paper proposes a slope location quotient(SLQ)index that reflects the relative advantage of cropland distribution and explores the slope grade difference of cropland spatial patterns in China at the county scale.The analysis adopts 30-m resolution digital elevation model with land cover data,taking 2672 counties with cropland ratio>1%as study units.The temporal scope covers 1990 and 2020,with slope gradients categorized into five grades:0°~2°,2°~6°,6°~15°,15°~25°,and 25°~90°.Results show that:1)The inverse correlation between cropland area and slope gradient remained stable throughout the study period,with the variation in cropland area frequency across slope grades being less than 1%.2)The spatial patterns of SLQ in 1990 and 2020 both transited stepwise with slope gradient,while≤2°and>6°slopes exhibited opposing patterns.3)The mean absolute variation of SLQ during 1990-2020 increased with slope gradient(R2=0.926,p<0.01).Particularly for slope grades>15°,the mean absolute variation reached 0.26(for 15°~25°)and 0.43(for 25°~90°),respectively,and displayed a distinct southward-increasing and northwarddecreasing pattern.This study offers novel slopegradient perspectives for analyzing cropland spatial patterns.To enhance cropland protection benefits,reversing the steep cropland SLQ surge in southern China is recommended.展开更多
The digital creative industry(DCI)has become increasingly integral to China’s digital economy and industrial restructuring landscape.This study scrutinized the spatial distribution patterns of four subindustries with...The digital creative industry(DCI)has become increasingly integral to China’s digital economy and industrial restructuring landscape.This study scrutinized the spatial distribution patterns of four subindustries within DCI sector,leveraging county/district-level enterprise data from 2022.Our findings reveal a distinct geographical pattern characterized by a gradual decline in DCI concentration from the southeastern to the northwestern regions.Additionally,by analyzing the location quotient of each province,we identify specific provinces that demonstrate comparative advantages across each subindustry within the DCI sector.展开更多
Through scientific researches and analysis of large quantities of detailed data of Northwestern China’s (NWC). The article illustrates position and present situation and advantages of NWC in Chinese economic developi...Through scientific researches and analysis of large quantities of detailed data of Northwestern China’s (NWC). The article illustrates position and present situation and advantages of NWC in Chinese economic developing, and studies the development opportvnities and challenges facing the NWC. factly, on the basic of the above analysic. The paper puts forword the development model and development means in the NWC.展开更多
基金Supported by the National Natural Science Foundation of China(40871061)
文摘According to the statistical data in the years 2004-2008,both Shift-Share Analysis and Location Quotient Analysis are used to compare the economic development status of counties(districts)in Dingxi City in the years 2004 and 2008.Advantages and disadvantages of industrial structure and competitiveness are analyzed,as well as the impacts of existing industrial structure on economic growth.Development direction and development focus of primary,secondary and tertiary industries are found out.Countermeasures for accelerating the economic development of counties(districts)in Dingxi City are put forward,such as increasing the inputs in characteristic agriculture,promoting the development of primary industry,speeding up the construction of large and medium industrial enterprises,enhancing the development of secondary industry,strengthening comprehensive environmental improvement in tourist area,and actively developing tertiary industry.
基金financial support from the Organismo Autónomo de Parques Nacionales(Project V09-Cátedra de Parques Nacionales)。
文摘Recreational Ecosystem Services(RES)are among the most frequently evaluated ecosystem services.RES are seen as a major opportunity for sustainable development in areas of high ecological value resulting from the presence of emblematic species,habitats or scenery,often integrated in conservation areas,in particular in mountain areas affected by depopulation,rising environmental risks and poverty.Economically,the assessment of RES has been based on Contingent Valuation and Choice Experiments,methods with limitations related to their subjectivity.Alternatively,Input-Output(IO)models provide a very accurate and effective way of valuation of RES with regional information regarding interindustry transactions.Whilst data on nature tourist expenditure may be only available annually,tourism inflows have a strong seasonal behavior,which impacts the profitability of several local economic activities.In this paper,we firstly constructed a novel regionalized IO-model based on Cross-Industry Location Quotients using employment data and,secondly,based on Monte Carlo simulation,we estimated nature tourist expenditure monthly using data on nature tourism inflows.This method allowed for a more precise RES evaluation,estimating direct,indirect and induced monthly economic impacts of nature-based tourism.The method was applied to the Ordesa and Monte Perdido(OMP)National Park in the Spanish Pyrenees.To estimate the average tourist expenditure,we collected and analyzed spending on commerce,hospitality and restaurants,leisure,and transport of 385 visitors.Results suggest that using a regionalized IO model leads to a considerable reduction of over-estimation of the economic impact of tourist expenditure estimated by conventional methods.Taking into consideration the direct,indirect and induced effects of tourist expenditure in 2016-2018,the total annual output effect in the OMP National Park amounted to€208.8 million,while the total income effect amounted to€86.29 million.Also,a total of 2,429 jobs were created which indicates that for each thousand annual visitors to the National Park,3.8 jobs are created in the surrounding area.Overall,the proposed methodology can be easily applied to the remaining National Parks in Spain or other regions in the world,making it a valuable tool to estimate the value of RES in areas affects by strong seasonality,to set priorities and support regional policies for mountain sustainable development.
基金Under the auspices of National Natural Science Foundation of China(No.41301143)
文摘Using data from the Economic Advisory Center of the State Information Center(SIC), we examined the spatial patterns of car sales in China at the prefectural level in 2012. We first analyzed the spatial distributions of car sales of different kinds of automakers(foreign automakers, Sino-foreign joint automakers, and Chinese automakers), and then identified spatial clusters using the local Moran's indexes. Location quotient analysis was applied to examine the relative advantage of each type of automaker in the local markets. To explain the variations of car sales across cities, we collected several socioeconomic variables and conducted regression analyses. Further, factor analysis was used to extract independent variables to avoid the problem of multicollinearity. By incorporating a spatial lag or spatial error in the models, we calibrated our spatial regression models to address the spatial dependence problem. The analytical results show that car sales varied significantly across cities in China, and most of the cities with higher car sales were the developed cities. Different automakers exhibit diverse spatial patterns in terms of car sales volume, spatial clusters, and location quotients. The scale and incomes factor were extracted and verified as the two most significant and positive factors that shape the spatial distributions of car sales, and together with the spatial effect, explained most of the variations of car sales across cities.
基金Supported by Important Special Research Projects of Guilin University of Electronic Technology (UF09022y)Special Subjects of Guangxi Human Social Science Research Center (XWSKYB2010006)Natural Science Fund of Guangxi Normal University for Nationalities(XYYB2010006)
文摘Taking Chongzuo City of Guangxi Zhuang Autonomous Region as an example, the employment effect of the resource-abundant industrial cluster in southwestern Guangxi Province is analyzed according to the data from the Chongzuo Statistical Yearbook , Guangxi Statistical Yearbook from 2003 to 2008 and the data from the relevant sections of Chongzuo City, and the four employment effects of industrial cluster--the spatial expansion effect of employment chain, optimizing effect of employment structure, the multiplier effect of employment absorption and the effect of improving the quality of labors and the degree of the intensity of employment and location quotient of employment. Results show that the employment absorption of sugar industry in Chongzuo City is stable and upward slightly, and it shows strong employment effect; the sugar industry in Chongzuo is not only competitive, but also has a great share of market in employment, so it owns strong absorption of employment. The countermeasures for improving the employment level of resource-abundant and industrial cluster in southwest of Guangxi Province are put forward, including elongating industrial chain and widening employment space; strengthening various kinds of formal and informal training to improve the employment capability of laborers; laying stress on industrial structure and optimizing the employment structure; strengthening the construction of the industrial economic zone towards ASEAN(Association of Southeast Asian Nations), and fully displaying the regional advantages of the offshore border.
基金Supported by"Research on Evaluation of Agricultural Resources and Construction of Industrial Aggregation Model in Sichuan Province"(08ZQ026-005)Sichuan Youth Foundation
文摘Based on introducing the basic conditions of the ethnic regions in northwest Sichuan Province,the thesis analyzes its agricultural development status,which can be classified into two aspects--rich natural resources and slow agricultural economic growth.Through the analysis on the agricultural structure of northwest Sichuan Province,it is found that the production efficiency and economic benefits of crop planting in this region are low,animal husbandry,as a major industry in pastoral region,sees high production efficiency,the agricultural production is still at the resource-oriented stage;its agricultural structure is still the farming-pastoral structure relying mainly on animal husbandry,planting is dominated by crop planting and potato planting,animal husbandry mainly produces dairy and beef;the ethnic regions in northwest Sichuan Province is endowed with the advantages to grow crops,beans and fruits as well as to produce beef,mutton and milk,among which,three industries,say fruit,beef and dairy are with increasing location quotient and gradually strengthening industrial comparative advantage,while the location quotient of the other industries is declining and their industrial comparative advantages are more stable.In order to promote the agriculture in northwest Sichuan Province to develop in breadth and depth,the thesis proposes the following measures and suggestions:the first one is to adhere to the development strategy of modern animal husbandry;the second is to appropriately improve the proportion of economic crops;the third is to accelerate the development of green food processing industry.
基金Supported by Project of Henan Provincial Department of Science and Technology(112400410017)Project of Henan Provincial Department of Education(2010-QN-008)
文摘On the basis of input-output table of Henan Province and China in 2007,this paper advances a simple method of constructing two-region input-output model using MRIO model,to research the economic link between the industries of Henan Province and the industries of other regions.I summarize the characteristics of this method based on this as follows:when researching inter-regional economic link,the multi-region or two-region input-output model has prominent superiority,and we can conduct preliminary estimation on the multi-region input-output model using location quotient approach.
基金Supported by the Major Program of Humanities and Social Sciences,Ministry of Education of China(10JYC790312)
文摘Firstly,agriculture,industry and tourism in the Yangtze River Delta,Pearl River Delta and Bohai Economic Rim were chosen to represent the primary,secondary and tertiary industries respectively,and industrial agglomeration in the three economic zones was analyzed using location quotient coefficient method.Afterwards,the critical factors influencing industrial agglomeration were discussed using gray correlation analysis.The results showed that industrial agglomeration of agriculture,industry and tourism formed gradually in the three economic zones,and the critical factors influencing industrial agglomeration were human capital,science and technology progress,and natural resources.Meanwhile,environmental pollution affected and restricted the development of industrial agglomeration.
基金Sponsored by National Natural Science Foundation of China(51309134)Research Starting Funds for Imported TalentsNingxia University(BQD2012011)
文摘On the basis of analyzing yearly data and spatial relationships between tourism spots, star hotels and travel agencies of Hainan Province, and comparing all the methods of measuring industrial spatial agglomeration, this paper chose Hefindahl index, Location Quotient, nearest neighbor index, spatial connection index and geographic concentration index to measure Hainan tourism agglomeration. By applying these methods, total tourism agglomeration, agglomeration of tourism factors and regional agglomeration differences were studied. The results showed that the overall agglomeration increases as time flows, and the eastern part is the most agglomerated, the west takes the second, with the middle ranking the least. The large-scale agglomeration regions are Sanya and Haikou. The influencing factors of Hainan tourism spatial agglomeration were concluded as tourism resource endowment, industrial attributes, geographic conditions, governmental policies and the overall economic development level, etc. In addition, the paper proposed tourism spatial agglomeration modes of Hainan Province at various spatial scales.
文摘In order to study the development status of kelp industry in Rongcheng in recent years, the centralization degree of kelp industry clusters and the comparative advantage of kelp industry in Rongcheng, Xiapu and Jinpu from 2010 to 2020 were compared and analyzed by indicators such as location quotient index, industrial agglomeration index, coefficient of concentration, scale advantage index, efficiency advantage index, and comprehensive advantage index, and the deep-seated factors affecting the competitiveness of kelp industry in Rongcheng were analyzed. Meanwhile, measures of improving the competitiveness of the kelp industry cluster in Rongcheng were put forward.
文摘Based on the 16 central cities＇ Panel Data in Yangtze River Delta, location quotient index is used in this paper to measure and analyze the current cluster situation of producer services in Yangtze River Delta, fixed effects model of Panel Data model is also used in this paper, and the industrial structure is taken as the dependent variable, while the core explanatory variables is the degree of producer services＇ cluster development, which is calculated by location quotient, moreover, three control variables introduced in this paper and they are technology advantage, education level and R＆D spending, and the mentioned above is to empirically study the impacts of producer services＇ cluster development to the regional industrial structure. As a result, producer services＇ cluster development has a significant positive role in promoting the regional industrial structure optimization and upgrading, though the extent is not yet a big push and is still to be further strengthened. In this paper, it has provided a strong evidence that under China＇ s new normal economy, producer services is badly needed to promote regional industrial structure, and finally it makes specific suggestions based on the current cluster situation of producer services in Yangtze River Delta.
基金supported by the National Key Research and Development Plan(No.2016YFF0203300)
文摘In order to achieve the model-based fault monitoring and diagnosis,an accurate model for the rotor system is necessary to locate and quantify faults.Since the dynamic characteristics of a blade-rotor system is influenced by foundation flexibility,the modeling and dynamic analyses on the foundation were sequentially investigated.Firstly,the effect of element size on the model convergence was investigated using the forward difference quotient as the slope of the frequency difference,which found that the model converged when the element size refined to 4mm.Secondly,a modal analysis and a harmonic response analysis were performed to obtain the dynamic characteristics of the foundation structure.Finally,an optimization to the foundation utilizing an additional stiffener was conducted to reduce the foundation response and make the critical speed far away from the working frequency band of 20—50Hz.
基金supported by the project of the National Natural Science Foundation of China entitled“Distribution and change characteristics of construction land on slope gradient in mountainous cities of southern China”(No.41961039)。
文摘China's requisition-compensation balance strategy has dramatically reshaped cropland spatial patterns,drawing multidisciplinary research attention.However,existing studies predominantly emphasize horizontal distribution,overlooking the significant influence of slope gradient on cropland spatial patterns.This paper proposes a slope location quotient(SLQ)index that reflects the relative advantage of cropland distribution and explores the slope grade difference of cropland spatial patterns in China at the county scale.The analysis adopts 30-m resolution digital elevation model with land cover data,taking 2672 counties with cropland ratio>1%as study units.The temporal scope covers 1990 and 2020,with slope gradients categorized into five grades:0°~2°,2°~6°,6°~15°,15°~25°,and 25°~90°.Results show that:1)The inverse correlation between cropland area and slope gradient remained stable throughout the study period,with the variation in cropland area frequency across slope grades being less than 1%.2)The spatial patterns of SLQ in 1990 and 2020 both transited stepwise with slope gradient,while≤2°and>6°slopes exhibited opposing patterns.3)The mean absolute variation of SLQ during 1990-2020 increased with slope gradient(R2=0.926,p<0.01).Particularly for slope grades>15°,the mean absolute variation reached 0.26(for 15°~25°)and 0.43(for 25°~90°),respectively,and displayed a distinct southward-increasing and northwarddecreasing pattern.This study offers novel slopegradient perspectives for analyzing cropland spatial patterns.To enhance cropland protection benefits,reversing the steep cropland SLQ surge in southern China is recommended.
文摘The digital creative industry(DCI)has become increasingly integral to China’s digital economy and industrial restructuring landscape.This study scrutinized the spatial distribution patterns of four subindustries within DCI sector,leveraging county/district-level enterprise data from 2022.Our findings reveal a distinct geographical pattern characterized by a gradual decline in DCI concentration from the southeastern to the northwestern regions.Additionally,by analyzing the location quotient of each province,we identify specific provinces that demonstrate comparative advantages across each subindustry within the DCI sector.
文摘Through scientific researches and analysis of large quantities of detailed data of Northwestern China’s (NWC). The article illustrates position and present situation and advantages of NWC in Chinese economic developing, and studies the development opportvnities and challenges facing the NWC. factly, on the basic of the above analysic. The paper puts forword the development model and development means in the NWC.
