Sensitivity analysis for probabilistic anti-resonance design of aeronautical hydraulic pipelines

In an uncertainty scheme, reliability and global sensitivity analysis is studied in this work, to provide helpful information for probabilistic anti-resonance design of vibration systems.Discussions show that the resonance failure problem can be viewed as a series system, in which input uncertainties are modeled by random variables. In order to quantitatively measure the contributions of input variables to the system reliability, a global sensitivity index is proposed, the properties of which are also discussed. Then the proposed index is tested with an aeronautical hydraulic pipeline system, which is under the excitation of pump vibration and at a risk of resonance failure. Sensitivity results under different failure criteria and variation coefficients are obtained and studied, from which significant and insignificant input variables can be identified.The proposed method provides a relatively new insight for anti-resonance design of engineering structures.     

超导重力仪器:机遇与挑战

超导重力仪器是利用超导电性构建的精密相对重力测量仪器，其工作于4.2K液氦温度，具有仪器固有噪声低、稳定性好的特点。阐述了超导重力仪和超导重力梯度仪两种仪器的工作原理与技术特征，简要介绍了作者所在课题组超导重力仪器研制的进展情况。分析了我国资源勘查用航空超导重力梯度仪研制所面临的机遇与挑战，提出了应对技术挑战的策略方法。     

面向下一代运载火箭的综合电子系统集成技术

介绍了面向下一代运载火箭分布式模块化电子系统(DIMA)的集成技术及系统架构。针对下一代运载火箭复杂电子系统的特点，按照系统集成的路线，对系统设计目标、系统功能需求分析、系统抽象机制、系统综合技术等多方面进行论述。首先，根据电气系统功能获得系统需求，采用功能抽象和层次抽象定义系统抽象模型，提取出高内聚低耦合的原子功能模块，并对模块的属性、交换关系、时序约束关系等进行定义；然后采用可视化表征方法对系统进行深入分析，利用系统综合技术实现了从系统功能到硬件资源的映射，从而给出了集成控制单元和模块的种类；随后采用分时分区的设计理念对系统节点分区划分方案及容错架构进行了定义，并对分区操作系统的调度模型和交换式的数据交互网络进行了论述，最终给出了系统软硬件架构。     

装备激励约束定价模式机理对比分析与设计

激励约束定价模式能够极大调动承包商积极性，是控制装备成本的一种重要方法。通过深入分析美军激励约束定价模式和我军激励约束定价模式的设计机理，提出了承包商的期望利润和军方期望价格的计算方法，并通过对比不同定价模式的特点，在借鉴2种激励约束定价模式优点基础上，设计了一种新的激励约束定价策略，提出了指导装备激励约束定价模式改革的对策建议。最后，通过算例对本文方法进行了解释，同时验证了本文方法的有效性。     

2024铝合金浸镍层的制备及生长过程

利用磷酸的全面腐蚀特性和氯离子的活化作用，设计了磷酸-氯化镍浸镍反应体系，通过表面电位监测及微观形貌表征对不同磷酸浓度与反应温度下的浸镍过程进行分析。结果表明:磷酸浓度是影响浸镍层表面电位及微观形貌的关键因素，当磷酸浓度为25%，反应温度为30℃时，可制得化学性质稳定、包覆性良好且晶粒尺寸均匀的浸镍层。在此反应体系下，浸镍层在形核后通过球状方式叠层生长，在反应进行600 s后得到厚度约1 μm的浸镍层，其表面电位可达到-0.51 V左右。      

(70~100)MeV准单能中子参考辐射场设计

国内基于串列加速器建立了144keV~15MeV的单能中子参考辐射场，解决了20MeV以下能区中子探测器注量、剂量等参数的量值溯源，但尚未建立20MeV以上能区准单能中子参考辐射场。随着航天空间中子探测任务的需要以及地面高能质子加速器的发展，20MeV以上能区准单能中子参考辐射场需求越来越突出。发展20MeV以上能区高能中子参考辐射场对于满足国防需求、推动中子计量学科发展具有重要意义。     

A two-step weighted least-squares method for joint estimation of source and sensor locations: A general framework

It is well known that the Two-step Weighted Least-Squares(TWLS) is a widely used method for source localization and sensor position refinement. For this reason, we propose a unified framework of the TWLS method for joint estimation of multiple disjoint sources and sensor locations in this paper. Unlike some existing works, the presented method is based on more general measurement model, and therefore it can be applied to many different localization scenarios.Besides, it does not have the initialization and local convergence problem. The closed-form expression for the covariance matrix of the proposed TWLS estimator is also derived by exploiting the first-order perturbation analysis. Moreover, the estimation accuracy of the TWLS method is shown analytically to achieve the Cramér-Rao Bound(CRB) before the threshold effect takes place. The theoretical analysis is also performed in a common mathematical framework, rather than aiming at some specific signal metrics. Finally, two numerical experiments are performed to support the theoretical development in this paper.     

行星着陆大气进入段自适应滑模抗扰控制方法

针对行星探测器着陆过程可能存在的干扰影响着陆精度问题，提出了一种抗干扰控制方法。首先建立行星探测器着陆控制模型，利用非线性干扰观测器实现对系统外部干扰的估计；在此基础上提出一种自适应滑模控制律，使得系统状态快速收敛到平衡点附近。最后，将该方法应用于火星着陆场景进行仿真。结果表明，提出的自适应滑模控制方法能够在未知扰动存在的情况下，有效实现行星探测器安全着陆，提高着陆任务的成功率。