Based on the nonmeasured morphological features of their skulls, the present papermakes a racio-typological comparative study of the Qinghai Lijiashan people of the Kayue culture andpopulations in the surrounding area...Based on the nonmeasured morphological features of their skulls, the present papermakes a racio-typological comparative study of the Qinghai Lijiashan people of the Kayue culture andpopulations in the surrounding areas. The results show that morphologically the Lijianshan people areclose to modern northern groups such as the Evenki, Mongolians, North Chinese, Japanese and Buryatsand differ from the Neolithic populations in Qinghai. There is hardly a hereditary relationship betweenthe Neolithic Qinghai populations and the Lijiashan people with the general character of primitive Mongoloids, which indicates their similarity to the modern East Tibetans. The retention of such primitivemorphological character is believed to have possibly been the result of the “genetic drift” appearing whenhuman societies lived in relative isolation.展开更多
目的观测一组汉族大学生人群上颌恒磨牙卡氏尖的表达情况。方法根据美国亚利桑那州立大学牙齿人类学系统(Arizona State University Dental Anthropology System,ASUDAS)的卡氏尖分级标准,对803名汉族大学生的口内照和石膏模型进行观测...目的观测一组汉族大学生人群上颌恒磨牙卡氏尖的表达情况。方法根据美国亚利桑那州立大学牙齿人类学系统(Arizona State University Dental Anthropology System,ASUDAS)的卡氏尖分级标准,对803名汉族大学生的口内照和石膏模型进行观测和分析。卡氏尖出现率的性别和牙位差异采用卡方检验分析,表达强度的双侧相关性采用Kendall相关性检验分析。结果卡氏尖的人群出现率在上颌第一、二恒磨牙分别为37.61%、3.99%,上颌第一恒磨牙显著高于上颌第二恒磨牙(P<0.01);男性上颌第一、二恒磨牙卡氏尖的出现率分别为46.73%、6.30%,女性上颌第一、二恒磨牙卡氏尖的出现率分别为27.95%、1.54%,男性显著高于女性(P<0.01);阳性表达以低强度表达(1~4级)为主,在上颌第一、二恒磨牙中分别占比67.37%和59.52%;卡氏尖的表达在上颌第一、二恒磨牙均具有一定的双侧相关性(tau⁃b=0.756,P<0.01;tau⁃b=0.477,P<0.01)。结论卡氏尖在该组汉族人群中主要发生于上颌第一恒磨牙,以低强度表达为主,掌握我国人群中卡氏尖的表达情况有重要的人类学和临床指导意义。展开更多
There is a remarkable difference in stress distribution between a specimen and a plate removed from the specimen.The plate presents a uniform stress distribution whereas the specimen presents a non-uniform stress dist...There is a remarkable difference in stress distribution between a specimen and a plate removed from the specimen.The plate presents a uniform stress distribution whereas the specimen presents a non-uniform stress distribution.Firstly,the real stress distributions in plates with thickness of 30,40 and 50 mm and then in the specimens were obtained through simulation and X-ray surface stress measurement.Secondly,in order to study the impact of specimens shapes and processing ways on the results accuracy,two irregular shapes (parallelogram and trapezoid) and two processing ways (saw and electron discharge machining (EDM)) were compared and analyzed by simulation and experiment using layer removal method,then the specimen effects on measurement results were evaluated.The results show that:1) the non-uniform stress distribution characteristics of the specimen near the surface of the cut is significant,the range of non-uniform stress distribution is approximately one-thickness distance away from the cut,and it decreases gradually along the depth;2) In order to ensure the stability in the results,it is suitable to take the specimen plane size 2-3 times of its thickness;3) Conventional processing methods have little effect on experimental results and the average deviation is less than 5%.展开更多
This paper presents a nonlinear multidimensional scaling model, called kernelized fourth quantifica- tion theory, which is an integration of kernel techniques and the fourth quantification theory. The model can deal w...This paper presents a nonlinear multidimensional scaling model, called kernelized fourth quantifica- tion theory, which is an integration of kernel techniques and the fourth quantification theory. The model can deal with the problem of mineral prediction without defining a training area. In mineral target prediction, the pre-defined statistical cells, such as grid cells, can be implicitly transformed using kernel techniques from input space to a high-dimensional feature space, where the nonlinearly separable clusters in the input space are ex- pected to be linearly separable. Then, the transformed cells in the feature space are mapped by the fourth quan- tifieation theory onto a low-dimensional scaling space, where the sealed cells can be visually clustered according to their spatial locations. At the same time, those cells, which are far away from the cluster center of the majority of the sealed cells, are recognized as anomaly cells. Finally, whether the anomaly cells can serve as mineral potential target cells can be tested by spatially superimposing the known mineral occurrences onto the anomaly ceils. A case study shows that nearly all the known mineral occurrences spatially coincide with the anomaly cells with nearly the smallest scaled coordinates in one-dimensional sealing space. In the case study, the mineral target cells delineated by the new model are similar to those predicted by the well-known WofE model.展开更多
文摘Based on the nonmeasured morphological features of their skulls, the present papermakes a racio-typological comparative study of the Qinghai Lijiashan people of the Kayue culture andpopulations in the surrounding areas. The results show that morphologically the Lijianshan people areclose to modern northern groups such as the Evenki, Mongolians, North Chinese, Japanese and Buryatsand differ from the Neolithic populations in Qinghai. There is hardly a hereditary relationship betweenthe Neolithic Qinghai populations and the Lijiashan people with the general character of primitive Mongoloids, which indicates their similarity to the modern East Tibetans. The retention of such primitivemorphological character is believed to have possibly been the result of the “genetic drift” appearing whenhuman societies lived in relative isolation.
文摘目的观测一组汉族大学生人群上颌恒磨牙卡氏尖的表达情况。方法根据美国亚利桑那州立大学牙齿人类学系统(Arizona State University Dental Anthropology System,ASUDAS)的卡氏尖分级标准,对803名汉族大学生的口内照和石膏模型进行观测和分析。卡氏尖出现率的性别和牙位差异采用卡方检验分析,表达强度的双侧相关性采用Kendall相关性检验分析。结果卡氏尖的人群出现率在上颌第一、二恒磨牙分别为37.61%、3.99%,上颌第一恒磨牙显著高于上颌第二恒磨牙(P<0.01);男性上颌第一、二恒磨牙卡氏尖的出现率分别为46.73%、6.30%,女性上颌第一、二恒磨牙卡氏尖的出现率分别为27.95%、1.54%,男性显著高于女性(P<0.01);阳性表达以低强度表达(1~4级)为主,在上颌第一、二恒磨牙中分别占比67.37%和59.52%;卡氏尖的表达在上颌第一、二恒磨牙均具有一定的双侧相关性(tau⁃b=0.756,P<0.01;tau⁃b=0.477,P<0.01)。结论卡氏尖在该组汉族人群中主要发生于上颌第一恒磨牙,以低强度表达为主,掌握我国人群中卡氏尖的表达情况有重要的人类学和临床指导意义。
基金Project(2005CB623708) supported by the National Basic Research Program of China
文摘There is a remarkable difference in stress distribution between a specimen and a plate removed from the specimen.The plate presents a uniform stress distribution whereas the specimen presents a non-uniform stress distribution.Firstly,the real stress distributions in plates with thickness of 30,40 and 50 mm and then in the specimens were obtained through simulation and X-ray surface stress measurement.Secondly,in order to study the impact of specimens shapes and processing ways on the results accuracy,two irregular shapes (parallelogram and trapezoid) and two processing ways (saw and electron discharge machining (EDM)) were compared and analyzed by simulation and experiment using layer removal method,then the specimen effects on measurement results were evaluated.The results show that:1) the non-uniform stress distribution characteristics of the specimen near the surface of the cut is significant,the range of non-uniform stress distribution is approximately one-thickness distance away from the cut,and it decreases gradually along the depth;2) In order to ensure the stability in the results,it is suitable to take the specimen plane size 2-3 times of its thickness;3) Conventional processing methods have little effect on experimental results and the average deviation is less than 5%.
基金supported by National Natural Science Foundation of China (No.40872193)
文摘This paper presents a nonlinear multidimensional scaling model, called kernelized fourth quantifica- tion theory, which is an integration of kernel techniques and the fourth quantification theory. The model can deal with the problem of mineral prediction without defining a training area. In mineral target prediction, the pre-defined statistical cells, such as grid cells, can be implicitly transformed using kernel techniques from input space to a high-dimensional feature space, where the nonlinearly separable clusters in the input space are ex- pected to be linearly separable. Then, the transformed cells in the feature space are mapped by the fourth quan- tifieation theory onto a low-dimensional scaling space, where the sealed cells can be visually clustered according to their spatial locations. At the same time, those cells, which are far away from the cluster center of the majority of the sealed cells, are recognized as anomaly cells. Finally, whether the anomaly cells can serve as mineral potential target cells can be tested by spatially superimposing the known mineral occurrences onto the anomaly ceils. A case study shows that nearly all the known mineral occurrences spatially coincide with the anomaly cells with nearly the smallest scaled coordinates in one-dimensional sealing space. In the case study, the mineral target cells delineated by the new model are similar to those predicted by the well-known WofE model.
