计算离散动力系统不稳定周期轨道的精英子空间差异演化算法

通过把探索周期轨道的问题转化为一个非负函数的极小化问题,基于空间收缩的思想,反复重新初始化种群以提高群体的差异性,提高对可行域探测的有效性,提出一类精英子空间差异演化算法求解不同类型非线性映射的不稳定周期轨道,对典型离散动力系统的初步仿真结果表明该算法是一种计算不稳定周期轨道的稳健有效算法.     

模型误差与轨道精度

应用模型与实际模型总是存在差异,如何从理论上探讨这种差异的影响以及在实际处理中如何进行选择是非常困难的。本文中分析了差异的主要原因,明确了模型误差的概念,并从理论上探讨了模型误差对轨道估计精度的影响,给出了具体的影响误差计算公式;在此基础上,提出了轨道参数的估计效率和客户效率的概念,并由此导出了模型误差处理原则,从而回答了实际数据处理中,模型误差处理方案的选择问题。最后,给出了一个应用实例     

航天用锂离子电池性能评估

通过对额定容量为10Ah电池的研究，评价了电池的比能量、高低温放电性能、循环性能及电池内阻等．实验表明，电池的能量密度超过150Wh／kg；室温与50℃的对比实验表明，随着放电倍率的增大，50℃时放电平台电压下降得更快；-10℃、-20℃及-30℃时电池放电容量分别为初始容量的97．1％、91．7％及83．3％；0．5C倍率充放电1000次循环后，电池容量仍为初始容量的86．6％；以25％、30％及40％放电深度模拟低轨道卫星做循环寿命实验，表现出良好的循环性能，已达到航天用锂离子电池性能指标．     

关于多项式周期轨道的乘子的计算

设Ｋ为有理数域Ｑ的有限扩张,ｆ是系数在Ｋ中的多项式．令Ωｋ＝｛αｋ,ｆ（αｋ）,…,ｆｎ－１（αｋ）｝,ｋ＝１,２,…,ｍ,用Ｈｎ,ｆ表示以ｆ的周期点（周期为ｎ）为根的多项式．如果Ｈｎ,ｆ在Ｋ上不可约,且所有轨道Ωｋ（ｋ＝１,２,…,ｍ）的乘子互不相同,则Ｖａｖａｌｄｉ和Ｈａｔｊｉｓｐｙｒｏｓ给出了一个计算轨道Ωｋ（ｋ＝１,２,…,ｍ）的乘子而无需计算这些轨道本身的算法,在本文中我们证明了Ｖａｖａｌｄｉ和Ｈａｔｊｉｓｐｙｒｏｓ所给的条件是多余的,为此我们证明了对于给定的多项式ｆ＝ｂｋｘｋ＋…＋ｂ１ｘ＋ｂ０,存在一个次数ｋ为的多项式序列ｆｌ＝ｂｋ（ｌ）ｘｋ＋…＋ｂ１（ｌ）ｘ＋ｂ０（ｌ）（ｉ∈Ｎ）使得ｂｊ（ｌ）→ｈｊ（ｌ→∞）,ｊ＝０,１,２,…,ｋ,并且Ｈｎ,ｆｌ在Ｑ（ｂ０（ｌ）,…,ｂｋ（ｌ））上不可约（ｌ∈Ｎ）．此外,如果ｘ０是ｆ的周期为ｎ的周期点,则（ｘ－ｘ０）ｘｌ是Ｈｎ,ｆ的一个因子当且仅当（ｘ－ｆ（ｘ０））ｉ是Ｈｎ,ｆ的一个因子．     

Orbit determination of Chang＇E-3 and positioning of the lander and the rover

Chang＇E-3 landed on the east of Sinus Iridum area on December 14, 2013, performing China＇s first successful soft landing on the lunar surface. We present the results on precision orbit determination and positioning of the lander and the rover. We and methods used to achieve period December 2-21, 2014. describe the data, modeling, position knowledge over the In addition to the radiometric X-band range and Doppler tracking data, delta differential one-way ranging data are also used in the calculation, which show that they strongly improve the accuracy of the orbit reconstruction. Total position overlap differences are about 20 and 30m for the 100km × 100km and 100 kmx 15 km lunar orbit, respectively, increased by ,- 50 % with respect to CE-2 and at the same level as other lunar spacecrafts of recent era such as SELENE and lunar reconnaissance orbiter （LRO）. The position error of the soft landing trajectory is less than 100 m. A kinematic statistical method is applied to determine the position of the lander and relative position of the rover with respect to the lander. The position difference of the lander is better than 50 m compared to LRO photograph result. Compared with the delta very long baseline interferometry （VLBI） group delay between the lander and the rover, the delta VLBI phase delay can improve the relative position of the rover from ～ 1,000 to ～1 m.     

High-precision orbit prediction and error control techniques for COMPASS navigation satellite

A new satellite orbit prediction method based on artificial neural network （ANN） model is proposed to improve the precision of orbit prediction. In order to avoid the difficulty of amending the dynamical model, it is attempted to use ANN model to learn the variation of orbit prediction error, and then the prediction result of ANN model is used to compensate the predicted orbit based on dynamic model to form a final predicted orbit. The experiment results showed that the orbit prediction error based on ANN model was less than that based on dynamical model, and the ent satellites and different improvement effects for differtime were different. The maximum rates of improvement of predicting 8, 15, 30 d were respectively 80 %, 77.77 %, 85 %. The orbit prediction error control technique based on the method of back overlap arc compare was brought forward to avoid the risk that the precision of predicted orbit is even worse after it is compensated by ANN model. The phenomena of failure were basically eliminated based on this technique, and the rate of failure was reduced from 30 % to 5 %. This technique could ensure that the engineering application of ANN model could come true.     

n—方体上的三角形映射的拓扑熵及分歧

本文给出了ｎ－方体上的三角形映射的拓扑熵的下确界，证明了存在ｎ－方体上的一个具有无穷拓扑熵的２∞型映射，此外，还构造了ｎ－方体上的一个单参数的三角形映射的Ｃｏ－族，它具有如下性质，随着其参数的单调变化，映射族无穷多次地经历了从混沌到有序又返回到混沌并最终返回到有序的动力学过程．     

空间目标的雷达识别技术

空间雷达目标识别在航天技术和战略预警中具有广阔的应用前景 ,它也是目前雷达目标识别技术应用较为成功的领域。总结了目前国内外该领域已有的研究成果 ,结合空间目标的动力学特性和电磁散射特性 ,探讨了在窄带和宽带雷达信号体制下的各种空间目标识别方法 ,并展望了该领域的技术发展趋势。     

K-M Fuzzy度量空间中一类更广泛的不动点定理

提出并证明了Ｋ－Ｍ Ｆｕｚｚｙ度量空间中另一类更广泛的不动点定理。     

加速器输出粒子的能量和轨道异常现象的实验分析——兼答陈绍光教授

作者完全运用狭义相对论分析,合肥、台湾、汉堡加速器输出的电子能量,其实没有狭义相对论专家计算的这么高,在恒定磁场中弯转的轨道半径也不是他们计算的值。