世界航天发射运输的发展趋势

 针对世界航天发射运输系统，梳理了国内外发展现状和发展特点，综合对比了国内外航天发射场、运载火箭、火箭发动机的发展现状，并提出了未来发展趋势和展望。提出了低成本进入空间将改变世界航天发展的基本格局，航天远程跨域运输将突破航空领域运输效率的极限，指出了天地往返运输将成为维系空间环境的必然选择，轨道的多样性将催生多样态全域发射能力，同时传统液氧/煤油、液氢/液氧、液氧/甲烷等推进体制的主力运用领域将会迎来重大变革。     

利用SRTM数据修测高山区地貌的探讨

在高海拔区域测制地形图,如青藏高原地区,所获取的遥感影像局部存在着大范围的高山阴影或云雪覆盖,造成立体观测地貌困难的现象,探讨应用SRTM数据对这类特殊区域地貌进行修测补绘。介绍了数据处理的作业过程,并对实验区SRTM与SPOT5影像立体测图成果进行实验对比分析,成果符合要求。     

Parameter estimation for dual-rate sampled Hammerstein systems with dead-zone nonlinearity

The identification of nonlinear systems with multiple sampled rates is a difficult task.The motivation of our paper is to study the parameter estimation problem of Hammerstein systems with dead-zone characteristics by using the dual-rate sampled data.Firstly,the auxiliary model identification principle is used to estimate the unmeasurable variables,and the recursive estimation algorithm is proposed to identify the parameters of the static nonlinear model with the dead-zone function and the parameters of the dynamic linear system model.Then,the convergence of the proposed identification algorithm is analyzed by using the martingale convergence theorem.It is proved theoretically that the estimated parameters can converge to the real values under the condition of continuous excitation.Finally,the validity of the proposed algorithm is proved by the identification of the dual-rate sampled nonlinear systems.     

创新生态战略与创新效率关系：基于创新生态网络视角

基于创新生态系统理论，通过引入创新生态环境和创新生态位，构建一个有调节的中介效应模型，并基于长三角制造业企业调研数据，采用Bootstrap方法进行检验，探究创新生态战略通过创新生态网络对企业创新效率的作用机理。研究结果表明：创新生态战略对企业创新效率具有正向影响；创新生态网络在创新生态战略与企业创新效率关系中发挥中介作用；并且创新生态环境和创新生态位调节该中介效应。研究结果从创新生态网络视角构建了创新生态战略向企业创新效率转化的中间机制，丰富了创新生态系统理论研究。     

串联系统备件满足率分配及配置优化

备件作为装备维修保障的重要物质资源,装备研制单位需要将使用方提出的备件满足率要求进行合理分配,为合理制定备件配置方案提供输入,已成为目前装备研制阶段急需解决的重要问题之一.针对备件满足率只有统计定义的问题,论文研究了单备件满足率和串联系统备件满足率的概率性质,给出了其概率模型,揭示了备件满足率的内涵和工程意义.在此基础之上,以串联系统备件满足率的概率模型为基础,研究了系统备件满足率的两种分配方法,即线性代数分配模型和以备件总重量最小为目标的备件配置优化模型,为合理制定串联系统备件保障方案提供了理论依据.     

基于沉积数值模拟的辫状河心滩演化

选取黄骅坳陷新近系典型辫状河沉积解剖区,利用密井网区动静态资料相结合识别和刻画心滩及其内部结构,在此基础上通过沉积数值模拟探究研究区心滩形成过程,并建立研究区心滩顺流迁移和横向迁移演化模式。结果表明:顺流加积、垂向加积、侧向加积和侵蚀作用共同塑造心滩的形态和内部结构;滩头侵蚀、滩尾顺流加积和垂向加积形成了心滩的顺流生长和垂向生长;侧向加积与侵蚀作用控制心滩的不对称侧向生长过程。     

The Convergence of Least-Squares Progressive Iterative Approximation for Singular Least-Squares Fitting System

Data fitting is an extensively employed modeling tool in geometric design. With the advent of the big data era, the data sets to be fitted are made larger and larger, leading to more and more leastsquares fitting systems with singular coefficient matrices. LSPIA (least-squares progressive iterative approximation) is an efficient iterative method for the least-squares fitting. However, the convergence of LSPIA for the singular least-squares fitting systems remains as an open problem. In this paper, the authors showed that LSPIA for the singular least-squares fitting systems is convergent. Moreover, in a special case, LSPIA converges to the Moore-Penrose (M-P) pseudo-inverse solution to the leastsquares fitting result of the data set. This property makes LSPIA, an iterative method with clear geometric meanings, robust in geometric modeling applications. In addition, the authors discussed some implementation detail of LSPIA, and presented an example to validate the convergence of LSPIA for the singular least-squares fitting systems.     

Simulation of dynamic recrystallization for an Al-Zn-Mg-Cu alloy using cellular automaton

A cellular automata (CA) model has been developed to predict and control the microstructure evolution during hot deformation on 7085 aluminum alloy. The initial microstructure and thermal-mechanical parameters were used as the input data of the CA model. To link microstructure evolution with macroscopic flow stress, dislocation density was set as an important internal state variable. The hot deformation behavior of 7085 aluminum alloy was studied by isothermal compression tests under a deformation temperature range of 623–723 K and a strain rate range of 0.001-1s^?1 up to true strains of 0.53–1.20. Electron backscattered diffraction technique and the CA model were utilized to systematically investigate the effects of strain, strain rate and deformation temperature on the microstructure evolution, and further to predict the average grain diameter and the recrystallization fraction after deformation. The simulated results were validated by the experimental data to demonstrate the feasibility and predictability of the CA model.