相比于以单波束测深原理为基础的ICCP、TERCOM等一维序列匹配辅助导航方法,基于多波束测深系统的二维阵列匹配算法增加了原始地形信息的丰富度,可以用来提高地形辅助匹配导航系统的精度和适用性。通过归一化灰度转换,使实时扫测地形和...相比于以单波束测深原理为基础的ICCP、TERCOM等一维序列匹配辅助导航方法,基于多波束测深系统的二维阵列匹配算法增加了原始地形信息的丰富度,可以用来提高地形辅助匹配导航系统的精度和适用性。通过归一化灰度转换,使实时扫测地形和原始数据库地形分别形成待匹配的模板灰度图和背景灰度图,采用圆窗口化搜索策略,分别计算实时图和子图的Hu矩,保证了相同地形特征的旋转不变性。通过归一化互相关算法衡量两个地形的相似性,得到匹配地形,实时的辅助主惯导修正误差。仿真表明,利用此匹配算法在实时扫测地形平坦区域和特征明显区域均能成功匹配;位置误差均在5个网格以内,能容忍的系统信噪比最小为9 d B,抗噪声能力强;Hu矩的抗旋转特性大大提高了此方法的适用性,能够满足高精度水下地形匹配辅助导航系统的苛刻要求。展开更多
Picea mongolica is an endemic and endangered species in China. Ecosystem made of Picea mongolica is a special sandy forest ecosystem in China. It is found at ecotone between forest and steppe, or agricultural district...Picea mongolica is an endemic and endangered species in China. Ecosystem made of Picea mongolica is a special sandy forest ecosystem in China. It is found at ecotone between forest and steppe, or agricultural district and pastoral area. Based on investigation, this paper discussed the formation and distribution of Picea mongolica and studied its nature according to ecotone theory. It is clarified that Picea mongolica belongs to Picea meyeri series. That is to say, it became a local race through long-term adaptation to the local climate, then formed allopatric semi-species, and finally turned into a taxonomical species. Picea mongolica forest is a super zonal climax community developing in ecotone between forest zone and steppe zone.展开更多
This study proposes a novel approach to study stress field distribution and overlying ground pressure behavior in shallow seam mining in gully terrain.This approach combines numerical simulations and field tests based...This study proposes a novel approach to study stress field distribution and overlying ground pressure behavior in shallow seam mining in gully terrain.This approach combines numerical simulations and field tests based on the conditions of gully terrain in the Chuancao Gedan Mine.The effects of gully terrain on the in situ stress field of coal beds can be identified by the ratio of self-weight stress to vertical stress(η) at the location corresponding to the maximum vertical stress.Based on the function η =j(h),the effect of gully terrain on the stress field of overlying strata of the entire field can be characterized as a significantly affected area,moderately affected area,or non-affected area.Working face 6106 in the Chuancao Gedan Mine had a coal bed Jepth <80 m and was located in what was identified as a significantly affected area.Hence,mining may cause sliding of the gully slope and increased loading(including significant dynamic loading) on the roof strata.Field tests suggest that significant dynamic pressures were observed at the body and foot of the gully slope,and that dynamic loadings were observed upslope of the working face expansion,provided that the expanding direction of the working face is parallel to the gully.展开更多
In order to determine the planar and volume distribution of sand bodies of the Jurassic Badaowan formation in Block T13 of Junggar basin,we used analysis of field outcrop and 3D seismic data,which play an essential ro...In order to determine the planar and volume distribution of sand bodies of the Jurassic Badaowan formation in Block T13 of Junggar basin,we used analysis of field outcrop and 3D seismic data,which play an essential role in areas of sparse well coverage.We describe sedimentary facies characteristics,sand body planforms,width and connectivity patterns of sand bodies,and vertical associations and successions by acoustic impedance inversion technology and sedimentological theory.Results of our study show braided fluvial strata deposits in the Jurassic Badaowan formation.Each sand body is approximately lenticular in shape.The width of each sand body falls in the range 100～800 m,with most between 200 and 400 m.The sand bodies vary in thickness from 4 to 13 m,with most below 9 m.The width/thickness ratios lie in the range 20～55.The connectivity of braided fluvial channel sand bodies is controlled by changes of accommodation space.One fining-upward sedimentary cycle of base-level rise is recognized in Badaowan formation,representing an upward rise of base level.The connectivity of sand bodies was found to be greatest in the early stage of base-level rise,becoming progressively worse with increasing base-level rise.展开更多
We combined the similar simulation with numerical simulation to analyze the movement and deforma- tion features of overlying strata caused by paste backfill mining, study the movement and deformation laws of the overl...We combined the similar simulation with numerical simulation to analyze the movement and deforma- tion features of overlying strata caused by paste backfill mining, study the movement and deformation laws of the overlying strata in paste backfill mining, structural movement of the stope strata as well as the stope stress distribution laws. Furthermore, authors also explored the key factors to the movement and deformation of the overlying strata in paste backfill mining. The results indicate that a caving zone existed in the bending zone only in the overlying strata of the paste backfill mining. Compared with the roof caving mining, the degree of stress concentration and area of influence in the paste filling stope were apparently smaller. And the degree of destruction and area of the overlying strata decreased prominently. Also, there was no apparent strata behavior in the working face. Lastly, the filling ratio was the key to control the movement and deformation of the overlying strata. Combined with a specific engineering example, the author proved the reliability of the simulation results and provided a theoretical basis for the further extension of the paste backfill mining.展开更多
文摘相比于以单波束测深原理为基础的ICCP、TERCOM等一维序列匹配辅助导航方法,基于多波束测深系统的二维阵列匹配算法增加了原始地形信息的丰富度,可以用来提高地形辅助匹配导航系统的精度和适用性。通过归一化灰度转换,使实时扫测地形和原始数据库地形分别形成待匹配的模板灰度图和背景灰度图,采用圆窗口化搜索策略,分别计算实时图和子图的Hu矩,保证了相同地形特征的旋转不变性。通过归一化互相关算法衡量两个地形的相似性,得到匹配地形,实时的辅助主惯导修正误差。仿真表明,利用此匹配算法在实时扫测地形平坦区域和特征明显区域均能成功匹配;位置误差均在5个网格以内,能容忍的系统信噪比最小为9 d B,抗噪声能力强;Hu矩的抗旋转特性大大提高了此方法的适用性,能够满足高精度水下地形匹配辅助导航系统的苛刻要求。
基金National Natural Science Foundation of China (39670133 39900019 30070129).
文摘Picea mongolica is an endemic and endangered species in China. Ecosystem made of Picea mongolica is a special sandy forest ecosystem in China. It is found at ecotone between forest and steppe, or agricultural district and pastoral area. Based on investigation, this paper discussed the formation and distribution of Picea mongolica and studied its nature according to ecotone theory. It is clarified that Picea mongolica belongs to Picea meyeri series. That is to say, it became a local race through long-term adaptation to the local climate, then formed allopatric semi-species, and finally turned into a taxonomical species. Picea mongolica forest is a super zonal climax community developing in ecotone between forest zone and steppe zone.
基金supported by the Fundamental Research Funds for the Central Universities of China University of Mining and Technology(No.2014ZDPY21)
文摘This study proposes a novel approach to study stress field distribution and overlying ground pressure behavior in shallow seam mining in gully terrain.This approach combines numerical simulations and field tests based on the conditions of gully terrain in the Chuancao Gedan Mine.The effects of gully terrain on the in situ stress field of coal beds can be identified by the ratio of self-weight stress to vertical stress(η) at the location corresponding to the maximum vertical stress.Based on the function η =j(h),the effect of gully terrain on the stress field of overlying strata of the entire field can be characterized as a significantly affected area,moderately affected area,or non-affected area.Working face 6106 in the Chuancao Gedan Mine had a coal bed Jepth <80 m and was located in what was identified as a significantly affected area.Hence,mining may cause sliding of the gully slope and increased loading(including significant dynamic loading) on the roof strata.Field tests suggest that significant dynamic pressures were observed at the body and foot of the gully slope,and that dynamic loadings were observed upslope of the working face expansion,provided that the expanding direction of the working face is parallel to the gully.
基金Financial support for this work,provided by the National Basic Research Program of China(No.2006 CB202300),
文摘In order to determine the planar and volume distribution of sand bodies of the Jurassic Badaowan formation in Block T13 of Junggar basin,we used analysis of field outcrop and 3D seismic data,which play an essential role in areas of sparse well coverage.We describe sedimentary facies characteristics,sand body planforms,width and connectivity patterns of sand bodies,and vertical associations and successions by acoustic impedance inversion technology and sedimentological theory.Results of our study show braided fluvial strata deposits in the Jurassic Badaowan formation.Each sand body is approximately lenticular in shape.The width of each sand body falls in the range 100～800 m,with most between 200 and 400 m.The sand bodies vary in thickness from 4 to 13 m,with most below 9 m.The width/thickness ratios lie in the range 20～55.The connectivity of braided fluvial channel sand bodies is controlled by changes of accommodation space.One fining-upward sedimentary cycle of base-level rise is recognized in Badaowan formation,representing an upward rise of base level.The connectivity of sand bodies was found to be greatest in the early stage of base-level rise,becoming progressively worse with increasing base-level rise.
基金supported by the National Natural Science Foundation of China (No. 50774077)the Special Funds of Universities Outstanding Doctoral Dissertation (No. 200760)+1 种基金the Independent Research Funding of the State Key Laboratory of Coal Resources and Mine Safety (No. SKLCRSM10X02)the Fundamental Research Funds for the Central Universities (Nos. 2010QNA31 and2010QNA32)
文摘We combined the similar simulation with numerical simulation to analyze the movement and deforma- tion features of overlying strata caused by paste backfill mining, study the movement and deformation laws of the overlying strata in paste backfill mining, structural movement of the stope strata as well as the stope stress distribution laws. Furthermore, authors also explored the key factors to the movement and deformation of the overlying strata in paste backfill mining. The results indicate that a caving zone existed in the bending zone only in the overlying strata of the paste backfill mining. Compared with the roof caving mining, the degree of stress concentration and area of influence in the paste filling stope were apparently smaller. And the degree of destruction and area of the overlying strata decreased prominently. Also, there was no apparent strata behavior in the working face. Lastly, the filling ratio was the key to control the movement and deformation of the overlying strata. Combined with a specific engineering example, the author proved the reliability of the simulation results and provided a theoretical basis for the further extension of the paste backfill mining.
