This thesis gives overview of the connotation of rural spatial structure,indicating 4 kinds of elements,namely nodus,passage,region and flow.Their spatial arrangement and interaction lead to the corresponding rural sp...This thesis gives overview of the connotation of rural spatial structure,indicating 4 kinds of elements,namely nodus,passage,region and flow.Their spatial arrangement and interaction lead to the corresponding rural spatial structure.This thesis also offers panorama of the related theoretical progress of intra-county and rural areas,indicating that the research theories of regional spatial structure at present,mainly focus on macroscopic region or urban space,but there is shortage of researches on county spatial structure,especially microscopic rural spatial structure.On such basis,4 kinds of theoretical models and characteristics of regional spatial structure have been introduced.We build analysis index system of rural structural elements on the basis of 4 elements,and conduct rural spatial structural analysis,taking Jinhu County as an example.The result shows that rural spatial structure in Jinhu County is still at stage of nucleus-cluster development and rural system is not so sound.In addition,the passage network system of infrastructure has not taken shape,and county economy presents diseconomy of scale.The spatial interaction and association among towns in Jinhu County are weak.The characteristic analysis model of spatial structure in this research can objectively reflect regional characteristic of spatial structure.展开更多
Economic English is a significant tool for students. This research intends to analyze the lexical characteristics of eco nomic English on vocabulary size, lexical density, word length, and frequency distribution from ...Economic English is a significant tool for students. This research intends to analyze the lexical characteristics of eco nomic English on vocabulary size, lexical density, word length, and frequency distribution from two sources aspects: BROWN Corpus and another corpus built by author, named CEE.展开更多
Chinese Pidgin English is a variety of the English language.It is one product of language contact.It is a blend;in vocabulary,pronunciation and grammar,it is simplified and localized.It is one kind of spoken language ...Chinese Pidgin English is a variety of the English language.It is one product of language contact.It is a blend;in vocabulary,pronunciation and grammar,it is simplified and localized.It is one kind of spoken language without formal rules,but it plays an important part in the evolution of language.展开更多
Channel structure has a significant effect on the heat transfer performance of PCHE.In this study,a set of rectangular straight channel PCHEs with different cross-section aspect ratios had been tested on S-CO_(2) heat...Channel structure has a significant effect on the heat transfer performance of PCHE.In this study,a set of rectangular straight channel PCHEs with different cross-section aspect ratios had been tested on S-CO_(2) heat transfer experimental platform,the effect of mass flow rate in both cold and heat sides,as well as the cross-section aspect ratio of the rectangular straight channel,on the heat transfer performance of PCHE was investigated.The results show that the comprehensive heat transfer performance of the rectangular cross-section is better than that of the semicircular cross-section;increasing the aspect ratio can improve the comprehensive heat transfer performance of PCHE,but the strengthening effect diminishes as the aspect ratio increases.Increasing the mass flow rate on both sides not only enhances the pre-cooler's cooling capacity and heat transfer,but also raises the pressure drop.In addition,an improved heat transfer correlation for rectangular cross-section PCHE was proposed,considering the effects of cross-sectional aspect ratio and pseudo-critical temperature is proposed in the range of Re from 3169 to 48474 and Pr from 0.98 to 12.5,the fited results better predict the local Nu and f magnitudes and trends in the pre-cooler under different cooling conditions,outperforming the simulated data and Gnielinski and Blasius correlation.展开更多
1 Background Taxonomy is the branch of science dedicated to discovering,characterizing,naming,and classifying objects or organisms so as to understand relationships between them and the factors of their formation.The ...1 Background Taxonomy is the branch of science dedicated to discovering,characterizing,naming,and classifying objects or organisms so as to understand relationships between them and the factors of their formation.The aims of classification are to identify and understand the objects for establishing an orderly system for the grouping objects.展开更多
基金Supported by Huaiyin Institute of Technology Young Talent Project of Science Foundation(HGQN0707)
文摘This thesis gives overview of the connotation of rural spatial structure,indicating 4 kinds of elements,namely nodus,passage,region and flow.Their spatial arrangement and interaction lead to the corresponding rural spatial structure.This thesis also offers panorama of the related theoretical progress of intra-county and rural areas,indicating that the research theories of regional spatial structure at present,mainly focus on macroscopic region or urban space,but there is shortage of researches on county spatial structure,especially microscopic rural spatial structure.On such basis,4 kinds of theoretical models and characteristics of regional spatial structure have been introduced.We build analysis index system of rural structural elements on the basis of 4 elements,and conduct rural spatial structural analysis,taking Jinhu County as an example.The result shows that rural spatial structure in Jinhu County is still at stage of nucleus-cluster development and rural system is not so sound.In addition,the passage network system of infrastructure has not taken shape,and county economy presents diseconomy of scale.The spatial interaction and association among towns in Jinhu County are weak.The characteristic analysis model of spatial structure in this research can objectively reflect regional characteristic of spatial structure.
文摘Economic English is a significant tool for students. This research intends to analyze the lexical characteristics of eco nomic English on vocabulary size, lexical density, word length, and frequency distribution from two sources aspects: BROWN Corpus and another corpus built by author, named CEE.
文摘Chinese Pidgin English is a variety of the English language.It is one product of language contact.It is a blend;in vocabulary,pronunciation and grammar,it is simplified and localized.It is one kind of spoken language without formal rules,but it plays an important part in the evolution of language.
基金supported by the National Natural Science Foundation of China(52276150).
文摘Channel structure has a significant effect on the heat transfer performance of PCHE.In this study,a set of rectangular straight channel PCHEs with different cross-section aspect ratios had been tested on S-CO_(2) heat transfer experimental platform,the effect of mass flow rate in both cold and heat sides,as well as the cross-section aspect ratio of the rectangular straight channel,on the heat transfer performance of PCHE was investigated.The results show that the comprehensive heat transfer performance of the rectangular cross-section is better than that of the semicircular cross-section;increasing the aspect ratio can improve the comprehensive heat transfer performance of PCHE,but the strengthening effect diminishes as the aspect ratio increases.Increasing the mass flow rate on both sides not only enhances the pre-cooler's cooling capacity and heat transfer,but also raises the pressure drop.In addition,an improved heat transfer correlation for rectangular cross-section PCHE was proposed,considering the effects of cross-sectional aspect ratio and pseudo-critical temperature is proposed in the range of Re from 3169 to 48474 and Pr from 0.98 to 12.5,the fited results better predict the local Nu and f magnitudes and trends in the pre-cooler under different cooling conditions,outperforming the simulated data and Gnielinski and Blasius correlation.
文摘1 Background Taxonomy is the branch of science dedicated to discovering,characterizing,naming,and classifying objects or organisms so as to understand relationships between them and the factors of their formation.The aims of classification are to identify and understand the objects for establishing an orderly system for the grouping objects.
