当前对于电力的使用方面越来越多,高电压的网络输电已经成为了生活中的常态。想要保证电网运行的安全稳定,需要采取良好的保障措施。过励磁是一些高电压变压器中常用的保护装置之一,对于提高变压器的运行效果有良好作用。500 k V变压器...当前对于电力的使用方面越来越多,高电压的网络输电已经成为了生活中的常态。想要保证电网运行的安全稳定,需要采取良好的保障措施。过励磁是一些高电压变压器中常用的保护装置之一,对于提高变压器的运行效果有良好作用。500 k V变压器使用过励磁进行保护,能够为人们的生产生活提供切实可靠的电力资源。该文主要从过励磁的内涵入手,对500 k V变压器过励磁的工作原理和保护特点进行细致而全面的说明和介绍。展开更多
Both governmental and non-governmental organizations are engaged in the promotion of soil and water conservation practices in Northern Ghana, but adoption is believed to be low. This study thus examines the determinan...Both governmental and non-governmental organizations are engaged in the promotion of soil and water conservation practices in Northern Ghana, but adoption is believed to be low. This study thus examines the determinants of conservation practices adoption by farming households in the area. Data for the study were collected from 445 households located in 15 communities in Northern Ghana. Univariate, bivariate and multivariate probit models were used to analyse the decision to adopt six conservation practices in the area. Results show that the major determinants of adoption are plot and cropping characteristics such as location; and socio-economic and institutional variables such as number of contacts with extension officers, membership in farmer association and distance to major market. A policy implication of the study is the strengthening of extension service in the area to significantly boost conservation adootion.展开更多
SPSS13.0 was used to process the data of the 1-6 batch of key cultural relic conservation units promulgated by the State Administration of Cultural Heritage of China;and multi-element evaluation method was used to cal...SPSS13.0 was used to process the data of the 1-6 batch of key cultural relic conservation units promulgated by the State Administration of Cultural Heritage of China;and multi-element evaluation method was used to calculate the composite distribution index.The spatial distribution of cultural relics of provinces in China can be divided into four grades,namely:very rich areas,rich areas,poor areas and very poor areas;the article analyzes the characteristics of cultural resources in spatial and temporal distribution.The paper holds that(1)the distribution of China's cultural relic tourism resources is relatively concentrated,different sharply from region to region,with more Han nation's heritage,less relics of the ethnic minorities;(2) Henan,Hebei,Shaanxi,Shanxi Province are the main regions with heavy distribution of cultural resources;(3) relics appeared in specific time periods in China's history.Ming and Qing Dynasties,Sui,Tang and Five Dynasties,Song,Liao and Jin,the Western Han,Shang and Zhou dynasties,the New Stone Age are the major periods producing more cultural relics.This paper also analyzes relationships of the emergence of cultural relics with production technology,specific historical process,specific geographical location,political system,religion,national culture,customs,architectural styles and techniques of the traditional cultural educational system.Finally,the paper discusses the development and protection of heritage.展开更多
文摘当前对于电力的使用方面越来越多,高电压的网络输电已经成为了生活中的常态。想要保证电网运行的安全稳定,需要采取良好的保障措施。过励磁是一些高电压变压器中常用的保护装置之一,对于提高变压器的运行效果有良好作用。500 k V变压器使用过励磁进行保护,能够为人们的生产生活提供切实可靠的电力资源。该文主要从过励磁的内涵入手,对500 k V变压器过励磁的工作原理和保护特点进行细致而全面的说明和介绍。
文摘Both governmental and non-governmental organizations are engaged in the promotion of soil and water conservation practices in Northern Ghana, but adoption is believed to be low. This study thus examines the determinants of conservation practices adoption by farming households in the area. Data for the study were collected from 445 households located in 15 communities in Northern Ghana. Univariate, bivariate and multivariate probit models were used to analyse the decision to adopt six conservation practices in the area. Results show that the major determinants of adoption are plot and cropping characteristics such as location; and socio-economic and institutional variables such as number of contacts with extension officers, membership in farmer association and distance to major market. A policy implication of the study is the strengthening of extension service in the area to significantly boost conservation adootion.
基金supported by Science Research Program of Hainan Provincial Education Bureau (Grant No Hj2008-79)funded by the National Natural Science Foundation of China (Grant Nos 40963001, 40061003, 40661013)Key Course Program of Natural Geography of Hainan Normal University and First-degree Course Program of Geographical Science of Hainan Province
文摘SPSS13.0 was used to process the data of the 1-6 batch of key cultural relic conservation units promulgated by the State Administration of Cultural Heritage of China;and multi-element evaluation method was used to calculate the composite distribution index.The spatial distribution of cultural relics of provinces in China can be divided into four grades,namely:very rich areas,rich areas,poor areas and very poor areas;the article analyzes the characteristics of cultural resources in spatial and temporal distribution.The paper holds that(1)the distribution of China's cultural relic tourism resources is relatively concentrated,different sharply from region to region,with more Han nation's heritage,less relics of the ethnic minorities;(2) Henan,Hebei,Shaanxi,Shanxi Province are the main regions with heavy distribution of cultural resources;(3) relics appeared in specific time periods in China's history.Ming and Qing Dynasties,Sui,Tang and Five Dynasties,Song,Liao and Jin,the Western Han,Shang and Zhou dynasties,the New Stone Age are the major periods producing more cultural relics.This paper also analyzes relationships of the emergence of cultural relics with production technology,specific historical process,specific geographical location,political system,religion,national culture,customs,architectural styles and techniques of the traditional cultural educational system.Finally,the paper discusses the development and protection of heritage.
