碳纳米管在汽车上的应用

碳纳米管具有独特的结构和优异的物理与力学性能,在众多领域有广阔的应用前景,在汽车上的应用也倍受关注。本文对碳纳米管在汽车上的已有应用及潜在的应用进行了综述,包括汽车新能源动力系统、轻量化结构材料、多功能复合材料等。     

一种基于SEA方法的舰艇防空作战电子对抗作战效能评估模型研究

文章运用SEA方法对舰载电子对抗作战构建了一个效能评估模型,并对评估参数提供了量化分析工具。利用实例计算对评估参数进行了分析,对电子对抗作战提出了参考意见。     

基于变权重的多因子来袭导弹威胁评估

为了能有效地对复杂战场态势进行估计,确定导弹阵地面临的威胁等级,文章提出了变权重的多因子来袭导弹威胁评估。能很好地反映战场的真实情况,为决策者提供有效快速的防护决策依据。通过仿真实例验证了该算法的有效性。     

D-S证据理论及其改进算法研究

在多传感器数据融合中,D-S证据理论对于处理不确定性问题是一种有效的方法。但是,当证据严重冲突或完全冲突时,利用D-S证据理论法计算容易给出错误的结果。改进的证据理论法虽然解决了上述问题,但通过分析数据试验发现改进方法在处理一般的证据时效果不理想。文章将经典证据理论和改进方法相结合,发挥两种方法的优点,以达到更好的识别效果。     

预制沉箱表面缺陷的成因分析及其改善对策

沉箱预制是重力式码头的主要分项工程,其预制质量直接影响码头的整体质量。结合汕头港广澳一期工程沉箱重力式码头的施工监理实践,分析大型沉箱预制表观质量缺陷常出现的位置;实际使用的材料、施工环境、人员操作等因素对表观质量缺陷成因的影响;并介绍采取的对策和取得的效果。     

Numerical solutions for a two-dimensional airfoil undergoing unsteady motion

Continuous vorticity panels are used to model general unsteady inviscid, incompressible, and two-dimensional flows. The geometry of the airfoil is approximated by series of short straight segments having endpoints that lie on the actual surface. A piecewise linear, continuous distribution of vorticity over the airfoil surface is used to generate disturbance flow. The no-penetration condition is imposed at the midpoint of each segment and at discrete times. The wake is simulated by a system of point vortices, which move at local fluid velocity. At each time step, a new wake panel with uniform vorticity distribution is attached to the trailing edge, and the condition of constant circulation around the airfoil and wake is imposed. A new expression for Kutta condition is developed to study (i) the effect of thickness on the lift build-up of an impulsively started airfoil, (ii) the effects of reduced frequency and heave amplitude on the thrust production of flapping airfoils, and (iii) the vortex-airfoil interaction. This work presents some hydrodynamic results for tidalstream turbine.     

Time-fuel synthetic optimal control of ship-borne special crane based on predictive average dynamic

Ship-bome special crane, a multi-joints and foldaway one, is important to study the most effective energy-saving ( i. e. synthetic time-fuel optimal) operation control mode. In this paper, by introducing weighted parameters, a time-fuel synthetic optimal criterion is obtained, and configuration of the optimal controller is verified. Furthermore, a predictive average dynamic method is put forward, and applied to treat nonlinearity and coupling of the crane. Finally, an optimal controller with feedback is designed. The validity of this approach is verified by simulation results.     

Analysis and experiment of a vessels shell cover in submarine structure

This paper aims to achieve analysis and experiment results that relate to mechanics capability and structural parameter of a special saddle shell of revolution. Theoretically speaking, the saddle shell of revolution consists of a toroidal shell and a spherical shell. The shells simultaneous equations can he solved with harmonious terms. Where, the fundamental equations can be solved by asymptotic exponential perturbation method. The equations of special solution can be solved by Hovozhilovs special solution. This new idea is from a study of some existing solutions of the toroidal shell. The results have heen proved by eompared with some experimental results. The experiments aims to study the effect caused by change of material parameter,or by change of different geometrie dimensions of the saddle shell,which include the ehange of thickness, the change of radius of shell, and the change of ribs. Finally, the accepted product of the saddle shell were reinforeed by a toroidal rib has been submitted.     

高黎贡山平导隧道TBM护盾延伸技术

大瑞铁路高黎贡山平导隧道TBM在掘进过程中遭遇断层破碎带地层,发生3次较严重的卡机事故。为降低施工风险,加快施工进度,节约施工成本,采用调研、工程对比与专家论证的方法,分析刀盘被卡的原因,研究护盾延伸的必要性与可行性,制定护盾延伸方案,即将护盾与刀盘的间距由原来的360 mm缩减为50 mm。实践表明： 护盾延伸改造效果明显,在Ⅳ、Ⅴ级围岩实际占比达到67%的情况下,继续掘进近1 500 m,未再发生卡机事故,大大提高了TBM的掘进效率。     

白沙湖大桥深水钻孔桩施工(5#墩)

介绍了白沙湖大桥水中5#墩钻孔桩施工的方案要点,即浮式钻孔平台在深水基础施工中的应用.