Using foxtail millet (Setaria italica (L.) Beauv.) male-sterile line 1066A as female parent and Yugu 1 primary trisomic series (1 - 7) and tetrasomics 8, 9 as male parents, chromosome location of gene for male-sterili...Using foxtail millet (Setaria italica (L.) Beauv.) male-sterile line 1066A as female parent and Yugu 1 primary trisomic series (1 - 7) and tetrasomics 8, 9 as male parents, chromosome location of gene for male-sterility and yellow seedling in line 1066A was studied by primary trisomic analysis. The plants of F-1 generation of trisomics 2 - 9 were obtained by crossing with a great many plants of 1066A. F-1 generation of trisomics was similar to their male parent in morphologic characters, the color of their seedling was green, and pollen was partially fertile. The segregation ratio of fertility to sterility is 3:1 in F-2 generation of trisomics 2, 3, 4, 5, 7, 8 and 9; and 14:1 only in F-2 generation of trisomic 6 (chi(0.05)(2) = 0.012). The segregation ratio of green seedling to yellow seedling is 12:1 only in F-2 generation of trisomic 7 (chi(0.05)(2) = 0.31), but in other cases, this ratio is 3:1. The results indicated that the male-sterility gene was located on chromosome 6, and the gene for yellow seedling was monogenic recessive and located on chromosome 7. The rate of trisomics transmission by pollen was tested, trisomics 8 and 9 were the highest in rates of trisomics transmission and followed by trisomics 6 and 4.展开更多
In view of the relative positioning problem between non-regular quadrilateral grids and regular rectangle grid nodes in the wave front construction method, concrete realization problems with four grid positioning meth...In view of the relative positioning problem between non-regular quadrilateral grids and regular rectangle grid nodes in the wave front construction method, concrete realization problems with four grid positioning methods （vector cross product judgment, angle sum, intersection-point, and signs comparison algorithms） in wave front construction which are commonly used in computer graphics are compared and analyzed in this paper. Based on the stability analysis of the location method, the calculation examples show that the vector cross product judgment method is faster and more accurate than other methods in the realization of the relative positioning between non-regular quadrilateral grids and regular rectangle grid nodes in wave front construction. It provides precise grid point attribute values for the next steps of migration and demigration.展开更多
Caving in coal mines releases significant amounts of dust and gas. This is exhausted from the mine by forcing the air to travel through the caved zones into a set of roadways known as bleeders. These bleeder entries a...Caving in coal mines releases significant amounts of dust and gas. This is exhausted from the mine by forcing the air to travel through the caved zones into a set of roadways known as bleeders. These bleeder entries are operated for the life of the mine, and therefore, they have to be kept in stable condition. Caving operations in coal mines are associated with Iongwall mines and complete pillar extraction. The pillars adjoining the caved zone sometimes show rib failures, posing a hazard for mine personnel travelling through the entry. In this paper, we present the results from analyses of bleeder pillars that are near the caved zones and are susceptible to damage because of the transfer of load during the caving process. In this study, bleeder pillars were simulated in a displacement discontinuity program. Results showed that the vertical stresses on bleeder pillars increased while the safety factor of bleeder pillar decreased during the caving process; however, when the caved zone completely consolidated, both the stresses and safety factor did not change for the remaining extraction. When similar extraction was performed at deeoer denths, vertical stress on pillars increased significantly_展开更多
The paper briefly describes the range and methods of the research on the stability of frozen wall. Using the Back Analysis Method combining with the model test of frozen wall, the comprebensive study on the stability ...The paper briefly describes the range and methods of the research on the stability of frozen wall. Using the Back Analysis Method combining with the model test of frozen wall, the comprebensive study on the stability of frozen wail is firstly carried out by the authors. Finally, a new viewpoint of adopting limited strain as the major eriteria of stability in frozen soil engineering is proposed.展开更多
As the strict limitation of primary structure in traditional force method and displacement method in indeterminate analysis may lead to complicated high-order linear equations, a breakthrough of the limitation, i.e., ...As the strict limitation of primary structure in traditional force method and displacement method in indeterminate analysis may lead to complicated high-order linear equations, a breakthrough of the limitation, i.e., the application of irregular force method and irregular displacement method, would be introduced in this paper to ease the difficulty of hand computations. By using hyperstatic primary structures and partly chained primary structures, the primary structures of force method and displacement method are reformed, and the order of the system is decreased. The technique is explained through examples. The significance of the new method is summarized.展开更多
The steered response power-phase transform (SRP-PHAT) sound source localization algorithm is robust in a real environment. However, the large computation complexity limits the practical application of SRP-PHAT. For a ...The steered response power-phase transform (SRP-PHAT) sound source localization algorithm is robust in a real environment. However, the large computation complexity limits the practical application of SRP-PHAT. For a microphone array, each location corresponds to a set of time differences of arrival (TDOAs), and this paper collects them into a TDOA vector. Since the TDOA vectors in the adjacent regions are similar, we present a fast algorithm based on clustering search to reduce the computation complexity of SRP-PHAT. In the training stage, the K-means or Iterative Self-Organizing Data Analysis Technique (ISODATA) clustering algorithm is used to find the centroid in each cluster with similar TDOA vectors. In the procedure of sound localization, the optimal cluster is found by comparing the steered response powers (SRPs) of all centroids. The SRPs of all candidate locations in the optimal cluster are compared to localize the sound source. Experiments both in simulation environments and real environments have been performed to compare the localization accuracy and computational load of the proposed method with those of the conventional SRP-PHAT algorithm. The results show that the proposed method is able to reduce the computational load drastically and maintains almost the same localization accuracy and robustness as those of the conventional SRP-PHAT algorithm. The difference in localization performance brought by different clustering algorithms used in the training stage is trivial.展开更多
文摘Using foxtail millet (Setaria italica (L.) Beauv.) male-sterile line 1066A as female parent and Yugu 1 primary trisomic series (1 - 7) and tetrasomics 8, 9 as male parents, chromosome location of gene for male-sterility and yellow seedling in line 1066A was studied by primary trisomic analysis. The plants of F-1 generation of trisomics 2 - 9 were obtained by crossing with a great many plants of 1066A. F-1 generation of trisomics was similar to their male parent in morphologic characters, the color of their seedling was green, and pollen was partially fertile. The segregation ratio of fertility to sterility is 3:1 in F-2 generation of trisomics 2, 3, 4, 5, 7, 8 and 9; and 14:1 only in F-2 generation of trisomic 6 (chi(0.05)(2) = 0.012). The segregation ratio of green seedling to yellow seedling is 12:1 only in F-2 generation of trisomic 7 (chi(0.05)(2) = 0.31), but in other cases, this ratio is 3:1. The results indicated that the male-sterility gene was located on chromosome 6, and the gene for yellow seedling was monogenic recessive and located on chromosome 7. The rate of trisomics transmission by pollen was tested, trisomics 8 and 9 were the highest in rates of trisomics transmission and followed by trisomics 6 and 4.
基金This research work is supported by the Projects of National Science Foundation of China （Grant No, 40574052 and 40437018） and National Basic Research Program of China （973 Program） （Grant No. 2007CB209603）.Acknowledgements We wish to thank Researcher Xu Tao for his advice and comment. We also thank Mrs. Wang Kun for her help in the process of translation.
文摘In view of the relative positioning problem between non-regular quadrilateral grids and regular rectangle grid nodes in the wave front construction method, concrete realization problems with four grid positioning methods （vector cross product judgment, angle sum, intersection-point, and signs comparison algorithms） in wave front construction which are commonly used in computer graphics are compared and analyzed in this paper. Based on the stability analysis of the location method, the calculation examples show that the vector cross product judgment method is faster and more accurate than other methods in the realization of the relative positioning between non-regular quadrilateral grids and regular rectangle grid nodes in wave front construction. It provides precise grid point attribute values for the next steps of migration and demigration.
基金CERB (Coal and Energy Research Bureau) for supporting this research work
文摘Caving in coal mines releases significant amounts of dust and gas. This is exhausted from the mine by forcing the air to travel through the caved zones into a set of roadways known as bleeders. These bleeder entries are operated for the life of the mine, and therefore, they have to be kept in stable condition. Caving operations in coal mines are associated with Iongwall mines and complete pillar extraction. The pillars adjoining the caved zone sometimes show rib failures, posing a hazard for mine personnel travelling through the entry. In this paper, we present the results from analyses of bleeder pillars that are near the caved zones and are susceptible to damage because of the transfer of load during the caving process. In this study, bleeder pillars were simulated in a displacement discontinuity program. Results showed that the vertical stresses on bleeder pillars increased while the safety factor of bleeder pillar decreased during the caving process; however, when the caved zone completely consolidated, both the stresses and safety factor did not change for the remaining extraction. When similar extraction was performed at deeoer denths, vertical stress on pillars increased significantly_
文摘The paper briefly describes the range and methods of the research on the stability of frozen wall. Using the Back Analysis Method combining with the model test of frozen wall, the comprebensive study on the stability of frozen wail is firstly carried out by the authors. Finally, a new viewpoint of adopting limited strain as the major eriteria of stability in frozen soil engineering is proposed.
文摘As the strict limitation of primary structure in traditional force method and displacement method in indeterminate analysis may lead to complicated high-order linear equations, a breakthrough of the limitation, i.e., the application of irregular force method and irregular displacement method, would be introduced in this paper to ease the difficulty of hand computations. By using hyperstatic primary structures and partly chained primary structures, the primary structures of force method and displacement method are reformed, and the order of the system is decreased. The technique is explained through examples. The significance of the new method is summarized.
基金supported by the National Natural Science Foundation of China(Grant Nos. 60971098 and 61201345)the Beijing Key Laboratory of Advanced Information Science and Network Technology(Grant No.XDXX1308)
文摘The steered response power-phase transform (SRP-PHAT) sound source localization algorithm is robust in a real environment. However, the large computation complexity limits the practical application of SRP-PHAT. For a microphone array, each location corresponds to a set of time differences of arrival (TDOAs), and this paper collects them into a TDOA vector. Since the TDOA vectors in the adjacent regions are similar, we present a fast algorithm based on clustering search to reduce the computation complexity of SRP-PHAT. In the training stage, the K-means or Iterative Self-Organizing Data Analysis Technique (ISODATA) clustering algorithm is used to find the centroid in each cluster with similar TDOA vectors. In the procedure of sound localization, the optimal cluster is found by comparing the steered response powers (SRPs) of all centroids. The SRPs of all candidate locations in the optimal cluster are compared to localize the sound source. Experiments both in simulation environments and real environments have been performed to compare the localization accuracy and computational load of the proposed method with those of the conventional SRP-PHAT algorithm. The results show that the proposed method is able to reduce the computational load drastically and maintains almost the same localization accuracy and robustness as those of the conventional SRP-PHAT algorithm. The difference in localization performance brought by different clustering algorithms used in the training stage is trivial.
