Feasibility analysis of high excess pressure cockpit using material substitution based on strain energy

The design concept of high excess pressure cockpit has been proposed as a solution to solve the ergonomics problems caused by cockpit environment.To address the contradiction among mass,economy,maneuverability and environment ergonomics,considering the composite advantages of high strength and lightweight,the feasibility analysis concept of high excess pressure cockpit based on material substitution is proposed in the paper.Based on the strain energy analysis on finite element model,the iteration design method of equal stiffness and lightening effect analysis on material substitution are presented,The weight reduction effect after material substitution can be evaluated intuitively by using equal stiffness curve.The calculation result of cockpit indicates that the lightening effect can reach 35.09%.Because of the complexity of cockpit design,bi-level optimization method is proposed and performed by means of the First-Order Radio algorithm.The research shows that the method can achieve good result.The feasibility of high excess pressure cockpit is studied from the aspect of the relationship between excess pressure and mass,and the research demonstrates that,due to the utilization of T300/4211 in place of 6061 alloy,the excess pressure of cockpit increases from 35 to 45 kPa,a 28.57%increase,while the cockpit mass is decreased by 12.56%.Thus,the contradiction among mass,economy and environment ergonomics can be coordinated,which can provide a reference for the design of high excess pressure cockpit.     

Novel way to research nonlinear feedback shift register

In this paper,we regard the nonlinear feedback shift register（NLFSR） as a special Boolean network,and use semi-tensor product of matrices and matrix expression of logic to convert the dynamic equations of NLFSR into an equivalent algebraic equation. Based on them,we propose some novel and generalized techniques to study NLFSR. First,a general method is presented to solve an open problem of how to obtain the properties（the number of fixed points and the cycles with different lengths） of the state sequences produced by a given NLFSR,i.e.,the analysis of a given NLFSR. We then show how to construct all 2^2^n-（l-n）/2^2^n-lshortest n-stage feedback shift registers（nFSR） and at least 2^2^n-（l-n）-1/2^2^n-l-1shortest n-stage nonlinear feedback shift registers（nNLFSR） which can output a given nonperiodic/periodic sequence with length l. Besides,we propose two novel cycles joining algorithms for the construction of full-length nNLFSR. Finally,two algorithms are presented to construct 2^2^n-2-1different full-length nNLFSRs,respectively.     

重型组合式多轴挂车转向机构的优化设计

对重型组合式多轴挂车的转向机构进行了分析,推导出了转向机构各部件之间的运动关系式,在此基础上建立了这类挂车转向系统机构的优化设计模型。应用复合形优化算法对建立的优化模型进行优化求解,并使用Ⅶ语言编写了图形用户界面程序。使用该优化程序对某专用车辆厂生产的多轴挂车转向机构进行了优化设计,计算结果表明该方法正确实用。     

Heat transfer of micro-droplet during free fall in drop tube

To explore the heat transfer of micro-droplet during free fall in the drop tube, the falling velocity and microgravity level are calculated. The Newtonian heat transfer formulation is coupled with the classical heat conduction equation to predict the heat transfer process within micro-droplet. Based on the numerical solution by finite difference method with implicit Euler scheme, the temporal evolution of thermal information inside micro-droplet is obtained including the temperature distribution, cooling rate, temperature difference and gradient. To quantitatively reveal the mechanism how the various factors affect the heat transfer of micro-droplet, the effects of physical properties of liquid metal and cooling gas as well as the micro-droplet size are studied. As the important indicators of heat transfer process, the cooling rate and temperature difference are acquired to systematically investigate the relationship between thermophysical properties and heat transfer process of different metallic micro-droplets.     

对传统建筑空间中模糊空间的初探

通过分析传统建筑中的模糊空间,探求了模糊空间在中国传统建筑中的模式和相应的处理手法,希望有助于吸取传统建筑文化营养,启发设计思路,创作出具有时代性和民族特色的建筑.     

纳米技术及其在精细化工中的应用

介绍了纳米物质的特性、制备方法及其在精细化工中的应用,对其发展前景进行了展望。     

Soft ionic-hydrogel electrodes for electroencephalography signal recording

Wet gel electrodes have been widely used for electroencephalography(EEG) signal recording, which generally causes skin abrasion and longer preparation time. In this paper, we present soft ionic-hydrogel based electrodes to overcome such drawbacks.In order to conveniently measure the EEG signals, we design the claw-like and patch-like structures for robust connection between metal(Ag/Ag Cl) electrodes and skin scalps. Next, we experimentally show that the soft ionic-hydrogel based electrodes have similar performance with the conventional wet gel electrodes in terms of the short-circuit noise, electrical impedance, and skin-electrode contact impedance on unprepared human skin, significantly better than dry electrodes and water-based electrodes.We further perform the EEG measurements and steady-state visual evoked potentials(SSVEP) experiments with five subjects to verify the effectiveness of the soft ionic-hydrogel based electrodes. The experimental results demonstrate that our developed soft ionic-hydrogel electrodes can record high-quality EEG signals in a fast and clean way, being a compelling option for EEG-based brain-computer interfaces.     

AZ91D镁合金管件挤压成形技术研究

采用在5000kN液压机上进行了AZ91D合金管件的挤压成形工艺生产试验研究，研究了挤压温度、模具预热温度、润滑剂、挤压比等工艺参数在镁合金管件挤压过程中的影响并确定了管件挤压合理的工艺参数。试验得出，挤压成形镁合金管件具有较好的力学性能：抗拉强度吼在289．7～308．9MPa之间，屈服强度σ。在276．106-288．795MPa之间，伸长率占在7．5％～10．1％之间。     

刍议长隧道建设中的变更管理策略

本文从长隧道建设中的围岩变更的具体管理操作方法、变更管理原则和程序、变更管理应注意的几个问题等方面出发,对福永码头至洲石路道路工程凤凰山长隧道建设中的变更管理策略进行了浅要地分析和探讨。