摘要：Since the landmark work of R. E. Kalman in the 1960s, considerable efforts have been devoted to time series state space models for a large variety of dynamic estimation problems. In particular, parametric filters that seek analytical estimates based on a closed-form Markov-Bayes recursion, e.g., recursion from a Gaussian or Gaussian mixture （GM） prior to a Gaussian/GM posterior （termed ＇Gaussian conjugacy＇ in this paper）, form the backbone for a general time series filter design. Due to challenges arising from nonlinearity, multimodality （including target maneuver）, intractable uncertainties （such as unknown inputs and/or non-Gaussian noises） and constraints （including circular quantities）, etc., new theories, algorithms, and technologies have been developed continuously to maintain such a conjugacy, or to approximate it as close as possible. They had contributed in large part to the prospective developments of time series parametric filters in the last six decades. In this paper, we review the state of the art in distinctive categories and highlight some insights that may otherwise be easily overlooked. In particular, specific attention is paid to nonlinear systems with an informative observation, multimodal systems including Gaussian mixture posterior and maneuvers, and intractable unknown inputs and constraints, to fill some gaps in existing reviews and surveys. In addition, we provide some new thoughts on alternatives to the first-order Markov transition model and on filter evaluation with regard to computing complexity.

摘要：为了探索相对论速调管放大器(RKA)的小型化技术,开展了同轴RKA周期永磁聚焦的物理与设计技术研究。周期永磁聚焦系统采用Halbach阵列结构,产生的磁场类型为周期性会切磁场。首先给出该系统的磁场各个分量的表达式,分析该系统磁场分布的特点,并推导得出该系统聚焦强流环形电子束的稳定条件。根据该稳定条件,对Ka波段同轴RKA设计了一个周期永磁聚焦系统,并优化了周期磁场参数,确定了磁场系统设计的最佳周期和幅值。研究结果显示,周期永磁(PPM)聚焦系统在周期长度18 mm和磁场幅值0.33T的条件下可引导500kV、6kA的同轴RKA,得到1GW的微波输出功率,物理分析确定了周期永磁聚焦系统应用于高功率同轴RKA的技术可能性。

摘要：设计了题为"分散液相微萃取-高效液相色谱法测定谷物中生育酚"的综合实验,并应用于化学基础综合实验教学中。本实验以新型样品前处理技术--分散液相微萃取技术为基础,通过查阅文献,确定了合适的萃取模式、分散策略、萃取装置、萃取效果评价指标、HPLC分离分析条件等实验内容。实验设计结合了新颖的科研内容,能引起学生主动探索未知的兴趣,是对基础化学实验操作技能的强化,有利于提高学生的创新能力和综合素质。

摘要：利用有限元方法对空心散热器的性能优化进行探讨。基于ANSYS Icepak仿真软件,在机箱简化模型内模拟空心散热器实现对一恒定热源的散热过程,获得散热器空心程度对系统内温度场的影响规律,进而分析风速对热阻、风阻的影响。结果表明:当散热器壁厚为1.25 mm时,散热效果最优,散热器最高温度约降低20.4%,质量减小约14.3%;散热器上的热阻随着风速的增大而减小,且逐渐趋于平缓,而风阻随着风速的增大而增大,且趋势愈发明显。在空心散热器设计中,应权衡选取风速,以期达到最佳的散热性能。