The development and application of several flot ation reagents of rare earth minerals in China since 1960s and their performance were described. Furthermore, the development trends of flotation reagents of ra re eart...The development and application of several flot ation reagents of rare earth minerals in China since 1960s and their performance were described. Furthermore, the development trends of flotation reagents of ra re earth minerals were discussed.展开更多
By NdFeB magnetic powders treated with the silicon cou-pling agents, mechanical properties of the magnetic composite are remark-ably improved, and its magnetic properties are not affected. The experi-ments show that t...By NdFeB magnetic powders treated with the silicon cou-pling agents, mechanical properties of the magnetic composite are remark-ably improved, and its magnetic properties are not affected. The experi-ments show that the silicon coupling agents react with the oxidates in the surface of NdFeB magnetic powders so that a good adhesiveness can be formed between epoxy resin and NdFeB powders. The results still indicate that the silk or wavy morphological structures in the fracture surface of the magnetic composite are more advantageous to its mechanical properties.展开更多
In this paper, we consider multi-agent consensus problems in a decentralised fashion. The interconnection topology graph among the agents is switching and undirected. The agent dynamics is expressed in the form of a d...In this paper, we consider multi-agent consensus problems in a decentralised fashion. The interconnection topology graph among the agents is switching and undirected. The agent dynamics is expressed in the form of a double integrator model. Two different cases are considered in this study. One is the leader-following case and the other is leaderless case. Based on graph theory and common Lyapunov function method, some sufficient conditions are obtained for the consensus stability of the considered systems with the neighbour-based feedback laws in both leader-following case and leaderless case respectively. Finally, two numerical examples are given to illustrate the obtained results.展开更多
目的探讨不同垂直骨面型骨性Ⅱ类成年女性患者强支抗内收上前牙口咽气道和舌骨位置改变,为正畸临床诊治提供参考。方法本研究已通过单位医学伦理委员会审查批准,并获得患者知情同意。选取60例骨性Ⅱ类成年女性患者,根据下颌平面角将患...目的探讨不同垂直骨面型骨性Ⅱ类成年女性患者强支抗内收上前牙口咽气道和舌骨位置改变,为正畸临床诊治提供参考。方法本研究已通过单位医学伦理委员会审查批准,并获得患者知情同意。选取60例骨性Ⅱ类成年女性患者,根据下颌平面角将患者分成骨性Ⅱ类均角组和骨性Ⅱ类高角组,两组患者上颌均拔除两侧第一前磨牙强支抗内收上前牙。收集治疗前后的锥形束CT(cone beam CT,CBCT),采用三维测量软件进行测量,分析口咽气道相关指标。结果均角组强支抗内收上前牙治疗前后10个口咽气道测量指标差异没有统计学意义(P>0.05),舌骨最高点到过蝶鞍垂直线的距离(perpendicular distance from the highest point of hyoid bone to the vertical line passing through the sella,H⁃X)值减小(P<0.05);高角组治疗后口咽气道下界面积(oropharyngeal area at the level of the epiglottis tip,OPA⁃E)、口咽气道下界面前后径(anterior⁃posterior diame⁃ters of the oropharynx at the level ofthe epiglottis tip,E⁃AP)、口咽气道最小横截面面积(most constricted axial area of the oropharynx,OPA⁃MCA)、口咽气道最小横截面前后径(anterior⁃posterior diameters of MCA area of the oro⁃pharynx,MCA⁃AP)较治疗前减小(P<0.001),口咽气道体积(oropharyngeal volume,OPV)较治疗前减小(P<0.05),舌骨最高点到过蝶鞍水平线的距离(perpendicular distance from the highest point of hyoid bone to the hori⁃zontal line passing through the sella,H⁃Y)和舌骨最高点到会厌基部的距离(highest point of hyoid bone to the epi⁃glottis base,H⁃Eb)值较治疗前增大(P<0.05)。结论均角型骨性Ⅱ类成年女性患者正畸强支抗内收上前牙治疗后口咽气道无改变,骨性Ⅱ类高角型成年女性患者强支抗内收上前牙口咽气道有减小的风险。展开更多
文摘The development and application of several flot ation reagents of rare earth minerals in China since 1960s and their performance were described. Furthermore, the development trends of flotation reagents of ra re earth minerals were discussed.
文摘By NdFeB magnetic powders treated with the silicon cou-pling agents, mechanical properties of the magnetic composite are remark-ably improved, and its magnetic properties are not affected. The experi-ments show that the silicon coupling agents react with the oxidates in the surface of NdFeB magnetic powders so that a good adhesiveness can be formed between epoxy resin and NdFeB powders. The results still indicate that the silk or wavy morphological structures in the fracture surface of the magnetic composite are more advantageous to its mechanical properties.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60674071)
文摘In this paper, we consider multi-agent consensus problems in a decentralised fashion. The interconnection topology graph among the agents is switching and undirected. The agent dynamics is expressed in the form of a double integrator model. Two different cases are considered in this study. One is the leader-following case and the other is leaderless case. Based on graph theory and common Lyapunov function method, some sufficient conditions are obtained for the consensus stability of the considered systems with the neighbour-based feedback laws in both leader-following case and leaderless case respectively. Finally, two numerical examples are given to illustrate the obtained results.
文摘目的探讨不同垂直骨面型骨性Ⅱ类成年女性患者强支抗内收上前牙口咽气道和舌骨位置改变,为正畸临床诊治提供参考。方法本研究已通过单位医学伦理委员会审查批准,并获得患者知情同意。选取60例骨性Ⅱ类成年女性患者,根据下颌平面角将患者分成骨性Ⅱ类均角组和骨性Ⅱ类高角组,两组患者上颌均拔除两侧第一前磨牙强支抗内收上前牙。收集治疗前后的锥形束CT(cone beam CT,CBCT),采用三维测量软件进行测量,分析口咽气道相关指标。结果均角组强支抗内收上前牙治疗前后10个口咽气道测量指标差异没有统计学意义(P>0.05),舌骨最高点到过蝶鞍垂直线的距离(perpendicular distance from the highest point of hyoid bone to the vertical line passing through the sella,H⁃X)值减小(P<0.05);高角组治疗后口咽气道下界面积(oropharyngeal area at the level of the epiglottis tip,OPA⁃E)、口咽气道下界面前后径(anterior⁃posterior diame⁃ters of the oropharynx at the level ofthe epiglottis tip,E⁃AP)、口咽气道最小横截面面积(most constricted axial area of the oropharynx,OPA⁃MCA)、口咽气道最小横截面前后径(anterior⁃posterior diameters of MCA area of the oro⁃pharynx,MCA⁃AP)较治疗前减小(P<0.001),口咽气道体积(oropharyngeal volume,OPV)较治疗前减小(P<0.05),舌骨最高点到过蝶鞍水平线的距离(perpendicular distance from the highest point of hyoid bone to the hori⁃zontal line passing through the sella,H⁃Y)和舌骨最高点到会厌基部的距离(highest point of hyoid bone to the epi⁃glottis base,H⁃Eb)值较治疗前增大(P<0.05)。结论均角型骨性Ⅱ类成年女性患者正畸强支抗内收上前牙治疗后口咽气道无改变,骨性Ⅱ类高角型成年女性患者强支抗内收上前牙口咽气道有减小的风险。
