The strength and failure characteristics of most natural rock mass are influenced by discontinues such as fissures, joints, and weak surfaces. In the present study, the strength and failure behavior of ubiquitous- joi...The strength and failure characteristics of most natural rock mass are influenced by discontinues such as fissures, joints, and weak surfaces. In the present study, the strength and failure behavior of ubiquitous- joint rock-l!ke specimens under uniaxial loading have been investigated by DIC （digital image correlation） and discrete element numerical method （PFC2D）. The results are obtained. Firstly, the UCSJ of spec- imens with γ= 15° or 30° shows similar tendency while α goes from 0° to 75°. With γ= 45° or 60°, the UCSJ of specimens increases when α goes from 0° to 30° and decreases after α goes beyond 30°. With γ=75°, the peak UCSJ value is reached when α=0°. The UCSJ value shows an increasing trend when α goes from 60° to 75°. Secondly, the ubiquitous-joint specimens present different failure modes for various levels of α and γ（β-α）. Based on the experimental results, the failure mode of ubiquitous-joint specimens can be classified into three categories： stepped path failure, failure through parallel plane, and failure through cross plane.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
A computable expression of the asymptotic expansion of the return map for a degenerate singular point of a class of planar differential system is given, and hence the stability and the type of the singular point can b...A computable expression of the asymptotic expansion of the return map for a degenerate singular point of a class of planar differential system is given, and hence the stability and the type of the singular point can be decided. These results generalize the corresponding results in [Nonlinearity, 13 （2000）, p.709].展开更多
Aiming at the low speed of traditional scale-invariant feature transform(SIFT) matching algorithm, an improved matching algorithm is proposed in this paper. Firstly, feature points are detected and the speed of featur...Aiming at the low speed of traditional scale-invariant feature transform(SIFT) matching algorithm, an improved matching algorithm is proposed in this paper. Firstly, feature points are detected and the speed of feature points matching is improved by adding epipolar constraint; then according to the matching feature points, the homography matrix is obtained by the least square method; finally, according to the homography matrix, the points in the left image can be mapped into the right image, and if the distance between the mapping point and the matching point in the right image is smaller than the threshold value, the pair of matching points is retained, otherwise discarded. Experimental results show that with the improved matching algorithm, the matching time is reduced by 73.3% and the matching points are entirely correct. In addition, the improved method is robust to rotation and translation.展开更多
基金funding from Project (Nos.51474249 and 51404179) supported by National Natural Science Foundation of ChinaProject Supported by Innovation Driven Plan of Central South University of China (No.2016CX019)Project (No. SKLGDUEK1405) funded by the Open Projects of State Key Laboratory for Geo-mechanics and Deep Underground Engineering of China University of Mining and Technology,in China
文摘The strength and failure characteristics of most natural rock mass are influenced by discontinues such as fissures, joints, and weak surfaces. In the present study, the strength and failure behavior of ubiquitous- joint rock-l!ke specimens under uniaxial loading have been investigated by DIC （digital image correlation） and discrete element numerical method （PFC2D）. The results are obtained. Firstly, the UCSJ of spec- imens with γ= 15° or 30° shows similar tendency while α goes from 0° to 75°. With γ= 45° or 60°, the UCSJ of specimens increases when α goes from 0° to 30° and decreases after α goes beyond 30°. With γ=75°, the peak UCSJ value is reached when α=0°. The UCSJ value shows an increasing trend when α goes from 60° to 75°. Secondly, the ubiquitous-joint specimens present different failure modes for various levels of α and γ（β-α）. Based on the experimental results, the failure mode of ubiquitous-joint specimens can be classified into three categories： stepped path failure, failure through parallel plane, and failure through cross plane.
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.
基金The work is supported by Zhejiang Provincial Natural Science Foundations(No.Y604359) National Natural Science Foundation of China (No.10371123,10471130).
文摘A computable expression of the asymptotic expansion of the return map for a degenerate singular point of a class of planar differential system is given, and hence the stability and the type of the singular point can be decided. These results generalize the corresponding results in [Nonlinearity, 13 （2000）, p.709].
基金supported by the National Natural Science Foundation of China(Nos.60808020 and 61078041)the National Science and Technology Support(No.2014BAH03F01)+1 种基金the Tianjin Research Program of Application Foundation and Advanced Technology(No.10JCYBJC07200)the Technology Program of Tianjin Municipal Education Commission(No.20130324)
文摘Aiming at the low speed of traditional scale-invariant feature transform(SIFT) matching algorithm, an improved matching algorithm is proposed in this paper. Firstly, feature points are detected and the speed of feature points matching is improved by adding epipolar constraint; then according to the matching feature points, the homography matrix is obtained by the least square method; finally, according to the homography matrix, the points in the left image can be mapped into the right image, and if the distance between the mapping point and the matching point in the right image is smaller than the threshold value, the pair of matching points is retained, otherwise discarded. Experimental results show that with the improved matching algorithm, the matching time is reduced by 73.3% and the matching points are entirely correct. In addition, the improved method is robust to rotation and translation.
