两种变截面的高压纳秒电阻分压器

文章介绍了一种具有完全横向电容补偿功能的特殊结构的电阻分压器——扇形分压器,以及另一种同时具有横向电容补偿和减小趋肤效应功能的锥形薄壁分压器,用于测量纳秒上升沿的脉冲高电压。简述了它们的补偿原理和结构。刻度表明,它们具有良好的响应特性,并给出了它们在脉冲加速器上测到的电压波形。     

热模锻成形7075铝合金平头锥壳实验研究

采用热模锻制备７０７５铝合金导弹锥壳模拟试件，研究了锻后锻件各部位金相组织和硬度值分布情况。结果表明，采用热模锻制务的导弹锥壳模拟件在成形过程中，金属流动比较均匀，锥壳具有较均匀的组织性能。     

锥型分布器床层的起始喷流速度和相间传质

本文对气固流化床内锥型气体分布器进行了研究，在实验的基础上提出了一个能描述床层在起始喷流点附近的气体行为的的数学模型。并用此模型，利用实验数据，进一步提出了计算起始喷流速度Ｕ（ｍｓｆ）和相间质量交换系数的经验关联式。     

圆锥印刷四臂螺旋天线的分析与设计

提出了一种应用于全球定位系统(GPS)的宽波束圆极化圆锥印刷四臂螺旋天线。数值分析表明螺旋角和螺旋臂的长度是影响波瓣宽度的两个主要因素,文中给出了其变化规律。基于此,我们设计了一个中心频率为1.57542GHz的圆极化圆锥印刷四臂螺旋天线,并制作了模型天线。测试结果显示该天线在中心频率处的3dB波瓣宽度约为200°,满足半球覆盖特性;3dB轴比带宽约为0.35GHz;驻波比在1.5以下的频率范围为1.47~1.6GHz。实验结果和仿真结果吻合良好。     

酸轧机组卡罗塞尔卷取机卷筒圆锥面过盈联接失效分析与对策

针对卡罗塞尔卷取机存在的卷筒轴与空心套联接螺栓频繁断裂问题,通过现场调查和理论分析。认为断裂原因由卷筒轴与空心套联接的圆锥配合面过盈量不足所致。为保证卷筒轴工作扭矩的传递,通过分析保证传递扭矩所需的圆锥配合面最小过盈量,并经圆锥配合面的试装,检测过盈量对轴承游隙的影响,最终确定了既能满足轴承游隙要求,又能有效传递工作扭矩的卷筒轴与空心套圆锥配合面的过盈量数据,在现场实施后,取得了满意效果。     

锥壳结构轴向刚度研究

从壳体的薄膜理论出发,推导锥壳的轴向刚度计算公式并利用有限元分析进行验证。根据公式,分析半锥角、锥壳高度等结构参数变化对轴向刚度的影响,为锥壳结构的设计提供参考。     

Pattern Synthesis and Polarization Optimization of a Conical Array

A feasible method for synthesizing millimeter-wave conical array and optimizing low cross-polarization is proposed.Starting from the far-field superposition principle,an efficient approach including element mutual coupling and mounted platform effects is used to calculate the far-field patterns.A coordinate transform is applied to create polarization quantities,and a general process for the element polarized pattern transformation is performed.Corresponding numerical example is given and the desired sidelobe level and low cross-polarization are optimized.The numerical results indicate the proposed method is valid.     

Optimum absorber temperature of a once-reflecting full conical concentrator of a low temperature differential Stirling engine

This paper provides a theoretical investigation on the optimum absorber temperature of a once-reflecting full conical concentrator for maximizing overall efficiency of a solar-powered low temperature differential Stirling engine. A mathematical model for the overall efficiency of the solar-powered Stirling engine is developed. The optimum absorber temperature for maximum overall efficiency for both limiting conditions of maximum possible engine efficiency and maximum possible engine power output is determined. The results indicated that the optimum absorber temperatures calculated from these two limiting cases are not significantly different. For a given concentrated solar intensity, the maximum overall efficiency characterized by the condition of maximum possible engine power output is very close to that of the real engine of 55% Carnot efficiency, approximately.     

Investigation into wall wrinkling in deep drawing process of conical cups

Wrinkling phenomenon has been one of the major limiting failure modes in sheet metal forming processes. Wrinkling phenomenon in sidewall area of the cup formed in the conical cup test was considered both experimentally and numerically. A new deflection function is developed in this research and the effects of material anisotropy on the onset of wrinkling are studied using Hosford and Hill-1948 yield criteria under isotropy, normal anisotropy and planar anisotropy conditions. It was observed that application of Hosford yield criterion resulted in better prediction of wrinkling onset. It was also found that as the effective stress increases, consistency between predicted results and experimental data at the onset of wrinkling improves. Also, a good agreement between experimental data and predictions using proposed deflection function is obtained.     

Asymptotic solutions of axisymmetric laminated conical shells

The three-dimensional (3D) solution of laminated conical shells subjected to axisymmetric loads is presented using the method of perturbation. The formulation begins with the basic 3D elasticity equations without making any static or kinematic assumptions in advance. After introducing a set of proper dimensionless variables, asymptotically expanding the field variables and then successively integrating the resulting equations through the thickness direction, we obtain the recursive sets of governing equations for various orders. The edge boundary conditions at each order level are derived as the resultant forms by following the variational approach. The method of differential quadrature (DQ) is used to determine the present asymptotic solution for various orders. For illustration purposes, the simply supported laminated conical shells under uniformly and sinusoidally distributed lateral pressure and the clamped laminated conical shells under edge torsion, are studied. It is shown that the present asymptotic DQ solution can be obtained order-by-order in a hierarchic and consistent manner and asymptotically approaches to the 3D elasticity solution.