相干态的相反态的量子：相位分布

研究了相干态｜α〉的相位相反态｜-α〉的量子相位分布，通过数值计算比较分析了相干态｜α〉的相位相反态｜-α〉的量子相位分布．结果发现相位相反态｜-α〉的量子相位分布量子相位分布振幅峰值移动的位置相差为π．     

Evolution of Generalized Sizing for Evaluation of Converter Fed Machines

lintroductionOnetraditionalmethodofevaluationistousetheDa'L.sizingequation,WhichevaluatesthemachinepoweronthebasisofairgapsurfacediameterD,andeffectivestacklengthL,'Formanyyears,researchershavebeeninterestedinconsidering,instead,themachineoutersurfacediam…     

中国人口增长预测模型

本文以Logistic人口阻滞增长模型为基础建立了我国人口增长的预测模型,对各年份全国人口总量增长的短、中、长期趋势作出了预测.从而为我国人口的控制与管理提供了一定的依据.     

碳氢化合物的密度与折光指数之间关系的探讨

本文分析了大量的碳氢化合物(烷烃、烯烃、炔烃、芳烃)密度和折光指数实验数据,发现各类碳氢化合物的密度ρ和折光指数n_D间存在着良好的线性关系 n_D=α+bρ式中a、b为常数。这种良好的线性关系对于碳氢化合物密度的测定以及推测分子结构具有一定意义。     

概率密度函数法研究重构吸引子的结构

Probability density function (PDF) method is proposed for analysing the structure of the reconstructed attractor in computing the correlation dimensions of RR intervals of ten normal old men.PDF contains important information about the spatial distribution of the phase points in the reconstructed attractor.To the best of our knowledge, it is the first time that the PDF method is put forward for the analysis of the reconstructed attractor structure.Numerical simulations demonstrate that the cardiac systems of healthy old men are about 6-6.5 dimensional complex dynamical systems.It is found that PDF is not symmetrically distributed when time delay is small, while PDF satisfies Gaussian distribution when time delay is big enough.A cluster effect mechanism is presented to explain this phenomenon.By studying the shape of PDFs, that the roles played by time delay are more important than embedding dimension in the reconstruction is clearly indicated.Results have demonstrated that the PDF method represents a promising numerical approach for the observation of the reconstructed attractor structure and may provide more information and new diagnostic potential of the analyzed cardiac system.     

电容式硅微加速度计系统的性能分析

介绍了微加速度计的工作原理,得出了不同方向上的加速度计的等效刚度.基于加速度计的集总模型分析,从能量和运动角度推导得出了加速度计的等效质量、精度和灵敏度的具体表达形式.从力学观点,总结了加速度计阻尼的影响因素.对开环和闭环加速度计系统的机械热噪声的特性和它们各自检测的动态范围进行研究后发现,电容式微加速度计的噪声主要由机械热噪声决定,并取决于加速度计系统的温度和阻尼.对闭环加速度计系统的测量结果表明,系统的精度可以达到mg数量级,量程为±50g的范围.     

糯玉米皖单5号高产栽培模式研究

采用二次回归正交旋转组合设计,对糯玉米皖单5号高产栽培的三项主要农艺措施进行田间试验.对数据利用电子计算机进行处理,得出数学栽培模式,并建立了模拟优化密度、氮肥和磷肥实施方案数学模型.结果表明:皖单5号种植密度为4408株/667m2;尿素为33.83kg/667m2;磷酸二铵为14.62kg/667m2,可获得258.37kg/667m2的产量.     

Inhibitory effects of jujuboside A on EEG and hippocampal glutamate in hyperactive rat

In this study, the inhibitory effect ofjujuboside A (JuA) on a penicillin sodium (Na-PCN) induced hyperactivity model was investigated. Cortical EEG (electroencephalogram) and the concentration of hippocampal Glutamate (Glu) were monitored simultaneously in vivo as indicators of rat's excitatory state. Power spectral density (PSD) and gravity frequency of PSD were calculated. JuA (0.05 g/L and 0.1 g/L) inhibited the EEG excitation effect caused by Na-PCN by increasing the power of δ1 and δ2bands (P＜0.01 vs model) and lowering the gravity frequency of PSD (P＜0.01 vs model). JuA also remarkably reduced the Glu elevation induced by Na-PCN (P＜0.05 vs model). Diazepam also depressed Glu concentration and lowered the gravity frequency,but it showed a different EEG pattern in increased β2-activity (P＜0.01 vs model). EEG excitation caused by Na-PCN correlated with Glu elevation during the first hour. Neurophysiological inhibitory effects of JuA and diazepam were more persistent than their Glu inhibitoty effects.     

宇宙质量密度与减速参量q0

通过对标准宇宙结构质量密度分析，讨论了宇宙质量密度对减速参量q0以及减速参量对确定宇宙学年龄、宇宙结构——是有限封闭的还是无限开放的的影响。     

人口老龄化与我国老龄产业发展问题的思考

党的十七大报告将以人为本的理念具体化为一项项民生政策,将目标明确为使全体人民"学有所教、劳有所得、病有所医、老有所养、住有所居",这为应对人口快速老龄化的挑战奠定了指导思想。随着科学技术的进步和人民生活水平的提高,人口平均寿命的延长,我国正迎来一个前所未有的"银发浪潮"。如何未雨绸缪应对"银发浪潮"的冲击,大力发展老龄产业,是值得各级人民政府、企事业单位和社会各界高度关注、重视和思考的问题。