针对连线干涉测量系统(CEI)在无模型时延或模型时延不准确条件下相位模糊度解算困难的问题,提出了利用伪码测距信号辅助的载波相位模糊解算方法。在测站距离约束下,根据两站所接收伪码信号的相对位置关系计算得到一个时延差作为解载波...针对连线干涉测量系统(CEI)在无模型时延或模型时延不准确条件下相位模糊度解算困难的问题,提出了利用伪码测距信号辅助的载波相位模糊解算方法。在测站距离约束下,根据两站所接收伪码信号的相对位置关系计算得到一个时延差作为解载波相位模糊的时延预报值。为了提高解模糊能力,引入了伪码捕获和跟踪的基本方法。仿真分析了不同信噪比下所能达到的最大精度,结果表明在信噪比高于0 d B时,可直接解算S频段的载波相位模糊;在信噪比较低时,可解算宽带群时延的相位模糊。在0 d B和-30 d B条件下重复试验1 000次,正确率分别达到99.88%和99.91%,证明了算法的有效性。展开更多
A subgroup H of finite group G is called pronormal in G if for every element x of G, H is conjugate to Hx in （H, Hx）. A finite group G is called PRN-group if every cyclic subgroup of G of prime order or order 4 is p...A subgroup H of finite group G is called pronormal in G if for every element x of G, H is conjugate to Hx in （H, Hx）. A finite group G is called PRN-group if every cyclic subgroup of G of prime order or order 4 is pronormal in G. In this paper, we find all PRN-groups and classify minimal non-PRN-groups （non-PRN-group all of whose proper subgroups are PRN-groups）. At the end of the paper, we also classify the finite group G, all of whose second maximal subgroups are PRN-groups.展开更多
A finite group G is called PN-group if G is not nilpotent and for every p-subgroup P of G, there holds that either P is normal in G or P lohtain in Z∞（G） or NG（P） is nilpotent, arbitary p ∈ π（G）. In this pap...A finite group G is called PN-group if G is not nilpotent and for every p-subgroup P of G, there holds that either P is normal in G or P lohtain in Z∞（G） or NG（P） is nilpotent, arbitary p ∈ π（G）. In this paper, we prove that PN-group is meta-nilpotent, especially, PN-group is solvable. In addition, we give an elementary, intuitionistic, compact proof of the structure theorem of PN- group.展开更多
The chemical formula of omphacite was expressed with （M<sub>Ⅱ</sub>M<sub>Ⅰ</sub>）（Si, AI）<sub>2</sub>O<sub>6</sub>.Cations that occupied the M<sub>Ⅱ</sub...The chemical formula of omphacite was expressed with （M<sub>Ⅱ</sub>M<sub>Ⅰ</sub>）（Si, AI）<sub>2</sub>O<sub>6</sub>.Cations that occupied the M<sub>Ⅱ</sub> site were large cations such as Ca or Na, and Na/（Na+Ca） ratio ranged from 0.2 to 0.8; the 6-coordinated M<sub>Ⅰ</sub> site accommodated cations such as Mg, Fe<sup>2+</sup>,Al, Fe<sup>3+</sup> ,and Al/（Al+Fe<sup>3</sup>+） ratio was more than 0.5 Omphacite space groups reported were C2/c, P2, P2/n, P2/c, cell parameters are a<sub>0</sub> = 0.9600—0.9630 nm, b<sub>0</sub> = 0.8750—0.8830 nm, C<sub>0</sub> =0.5230—0.5290 nm,β = 106°40’—107°10’. The sample was picked up from the eclogites in Zhucheng County, Shangdong Province. The intensity data were collected with the RIGAKU RASA Ⅱ -S four-circle single crystal diffractometer. The correct structure model was obtained by using the Patterson method and Fourier synthesis, SHELX-76 program, structure refinement with 905 independent diffraction points （|F<sub>0</sub>|】 3σ|F<sub>0</sub> |）. After the structure parameter refinement, the R-factor reduced to 0.0515. The crystal structure analysis indicates that omphacite has a new展开更多
文摘针对连线干涉测量系统(CEI)在无模型时延或模型时延不准确条件下相位模糊度解算困难的问题,提出了利用伪码测距信号辅助的载波相位模糊解算方法。在测站距离约束下,根据两站所接收伪码信号的相对位置关系计算得到一个时延差作为解载波相位模糊的时延预报值。为了提高解模糊能力,引入了伪码捕获和跟踪的基本方法。仿真分析了不同信噪比下所能达到的最大精度,结果表明在信噪比高于0 d B时,可直接解算S频段的载波相位模糊;在信噪比较低时,可解算宽带群时延的相位模糊。在0 d B和-30 d B条件下重复试验1 000次,正确率分别达到99.88%和99.91%,证明了算法的有效性。
基金Supported by Natural Science Foundation of China （Grant No. 10871032）, Graduate Student Research and Innovation Program of Jiangsu Province （Grant No. CX10B-028Z）
文摘A subgroup H of finite group G is called pronormal in G if for every element x of G, H is conjugate to Hx in （H, Hx）. A finite group G is called PRN-group if every cyclic subgroup of G of prime order or order 4 is pronormal in G. In this paper, we find all PRN-groups and classify minimal non-PRN-groups （non-PRN-group all of whose proper subgroups are PRN-groups）. At the end of the paper, we also classify the finite group G, all of whose second maximal subgroups are PRN-groups.
基金the National Natural Science Foundation of China （No. 10571181） the Natural Science Foundation of Guangdong Province （No. 06023728）.Acknowledgement The author wishes to thank Prof. Guo Wenbin for his help. The author also thanks the referees for their helpful comments.
文摘A finite group G is called PN-group if G is not nilpotent and for every p-subgroup P of G, there holds that either P is normal in G or P lohtain in Z∞（G） or NG（P） is nilpotent, arbitary p ∈ π（G）. In this paper, we prove that PN-group is meta-nilpotent, especially, PN-group is solvable. In addition, we give an elementary, intuitionistic, compact proof of the structure theorem of PN- group.
文摘The chemical formula of omphacite was expressed with （M<sub>Ⅱ</sub>M<sub>Ⅰ</sub>）（Si, AI）<sub>2</sub>O<sub>6</sub>.Cations that occupied the M<sub>Ⅱ</sub> site were large cations such as Ca or Na, and Na/（Na+Ca） ratio ranged from 0.2 to 0.8; the 6-coordinated M<sub>Ⅰ</sub> site accommodated cations such as Mg, Fe<sup>2+</sup>,Al, Fe<sup>3+</sup> ,and Al/（Al+Fe<sup>3</sup>+） ratio was more than 0.5 Omphacite space groups reported were C2/c, P2, P2/n, P2/c, cell parameters are a<sub>0</sub> = 0.9600—0.9630 nm, b<sub>0</sub> = 0.8750—0.8830 nm, C<sub>0</sub> =0.5230—0.5290 nm,β = 106°40’—107°10’. The sample was picked up from the eclogites in Zhucheng County, Shangdong Province. The intensity data were collected with the RIGAKU RASA Ⅱ -S four-circle single crystal diffractometer. The correct structure model was obtained by using the Patterson method and Fourier synthesis, SHELX-76 program, structure refinement with 905 independent diffraction points （|F<sub>0</sub>|】 3σ|F<sub>0</sub> |）. After the structure parameter refinement, the R-factor reduced to 0.0515. The crystal structure analysis indicates that omphacite has a new
