最小二乘直线函数的特性分析

证明了最小二乘直线函数是一种严格的凸函数。F(a,b)=∑(y-ax_i-b)~2是一个椭圆抛物面。a=[n∑x_iy_i-∑x_i∑y_i]/[n∑x_i^2-(∑x_i)~2]和b=[∑x_i^2∑y_i-∑x_i∑x_i∑y_i]/[n∑x_i^2-(∑x_i)~2]仅表示极值点。a=∑x_iy_i/∑x_i和 b=[∑x_i^2∑y_i-∑x_i∑x_iy_i]/[n∑x_i^2]在某些情况下可以是极值点,但不是在每种情况下都是极值点。     

光栅信号时钟脉冲细分的误差分析

简介时钟脉冲细分技术的原理，着重分析其细分误差因素，给出了计算实际最大细分数的理论公式，并论述了光栅最大运动速度、时钟脉冲分频数和实际最大细分数之间的关系，对光栅信号时钟脉冲细分系统的参数设计具有指导意义。     

综合运用"四个机制"促进航空装备研制

根据航空武器装备研制应当建立竞争、评价、监督、激励“四个机制“的规定,结合本企业实际,就综合运用“四个机制“、促进航空装备研制提出了见解与建议.     

k-ε-g紊流燃烧模型数值研究

本文对k-ε-g紊流燃烧模型中模型系数C_R,C_(g1),C_(g2)的选定和计算浓度脉动均方值g的不同方法进行数值研究。计算结果表明模型系数值的选定直接与化学反应速率有关,而其中C_R影响最大。g的计算虽然可有不同方法,而其中微分方程求解最佳。并用实验数据来验证计算结果。     

通用模拟示波器故障的分析与诊断

本文将通用模拟示波器电路分成五部分，总结和分析了每一部分电路故障可能引起的几种异常显示，给出了每一部分电路故障诊断方法及在相应电路中出现故障的常见器件，对有些故障与故障现象之间的因果关系做了进一步分析。     

多点法测量形状误差的补偿控制系统

经过对误差分离技术理论进行了分析之后,又对误差补偿技术进行了研究,并建立了多点法测量形状误差的补偿控制系统。通过补偿主轴径向误差运动,提高了工件的圆度误差和圆柱度误差。     

企业本质、企业绩效与会计分析的逻辑关系

企业本质被界定为不完备要素使用权资本化交易合约履行的过程，从价值角度可以描述为财务资本、人力资本、组织资本与社会资本的一个不完全契约组合。正确认识企业本质是探讨企业绩效决定因素的关键，会计分析必须从企业资本有机构成角度来衡量企业绩效。     

The Genesis Solar Wind Concentrator Target: Mass Fractionation Characterised by Neon Isotopes

The concentrator on Genesis provided samples of increased fluences of solar wind ions for precise determination of the oxygen isotopic composition. The concentration process caused mass fractionation as a function of the radial target position. This fractionation was measured using Ne released by UV laser ablation and compared with modelled Ne data, obtained from ion-trajectory simulations. Measured data show that the concentrator performed as expected and indicate a radially symmetric concentration process. Measured concentration factors are up to ∼30 at the target centre. The total range of isotopic fractionation along the target radius is 3.8%/amu, with monotonically decreasing ²⁰Ne/²²Ne towards the centre, which differs from model predictions. We discuss potential reasons and propose future attempts to overcome these disagreements.     

CFG桩复合地基应力比数值分析

本文采用有限元ANSYS程序对CFG桩复合地基的单桩桩体荷载传递规律、应力比及影响因素进行了分析,得出了减小应力比的方法和措施,对工程可起借鉴的作用。     

General relativistic radiation hydrodynamics: Mixed-frame approach

I show how general relativistic 3D radiation hydrodynamic equations can be derived from the tensor formulation. Radiation quantities are differentiated with respect to the fixed coordinates while the interaction between matter and radiation is described by the comoving frame quantities. The formulation is covariant, and can be applied to any coordinates or spacetime; I show the derivation for the Schwarzschild spacetime as an example.