共查询到20条相似文献,搜索用时 109 毫秒
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本文应用数学理论推导出不等精度测量中的最可信赖值及误差 ,使测量中使用公式在理论上得以证明 相似文献
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高一物理现行课本简谐振动的周期一节,对简谐振动周期公式,只给出了结果没有推导过程,学生学过之后印象不深,如果教师在讲授时用实验验证一下,可以收到事半功倍的效果. 多数学校都有如图1所示的演示弹簧振子.如果用弹簧振子验证公式,则公式中的m表示振子锤的质量,k表示弹簧的倔强系数. 相似文献
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根据波动光学的理论,对菲涅耳近场衍射公式误差相位的影响进行了分析。以单缝衍射为例,讨论了误差相位与计算精度的联系。结合菲涅耳线波带片焦面光强分布的计算,对比了菲涅耳衍射公式与基尔霍夫衍射公式的计算结果,说明在不满足误差相位近似条件下使用菲涅耳衍射公式带来的影响。最后对影响波带片焦面光强分布的几个因素进行了讨论。 相似文献
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在实验数据的处理中。估算问接测得量的误差时。经常引用加减运算、乘除运算的代数误差公式。但是。代数误差公式并不是普遍适用的。本证明。代数误差公式适用的充分条件是取误差的各量相互独立。 相似文献
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本文提出一种测定显色反应焓变的简单实验方法,推导出吸光度与温度的关系式,用Tween-80介质中的硫氰酸钴(Ⅱ)配合物显色反应验证了关系式的线性关系,得到相关系数r为0.9957,ΔH=-44.7kJ.moL^-1,同Vant Hoff方程得到的结果基本一致。 相似文献
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In enhanced oil recovery by chemical flooding within tertiary oil recovery, it is often necessary to choose optimal viscous profiles of the injected displacing fluids that reduce growth rates of hydrodynamic instabilities the most thereby substantially reducing the well-known fingering problem and improving oil recovery. Within the three-layer Hele–Shaw model, we show in this paper that selection of the optimal monotonic viscous profile of the middle-layer fluid based on well known theoretical upper bound formula [P. Daripa, G. Pasa, A simple derivation of an upper bound in the presence of a viscosity gradient in three-layer Hele–Shaw flows, Journal of Statistical Mechanics (2006) 11. http://dx.doi.org/10.1088/1742-5468/2006/01/P01014] agrees very well with that based on the computation of maximum growth rate of instabilities from solving the linearized stability problem. Thus, this paper proposes a very simple, fast method for selection of the optimal monotonic viscous profiles of the displacing fluids in multi-layer flows. 相似文献
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用半径经典方法计算类Li离子电偶极跃迁的碰撞强度。用碰撞参数为b的双曲线轨道描述入射电子的运动,用时间有关的微扰理论方法描述靶态的跃迁几率,通过对碰撞参数的积分求出电子碰撞激发截面。碰撞强度可表示成与振子强度成线性关系的简单公式。计算了若干个类Li离子2s-2p1/2、2p3/2的碰撞强度。结果表明,除在阈能附近以外,大部分数据与用较精确的相对论扭曲波的计算结果符合得很好。所用方法简单,而且可以进行快速计算,有很大的实用价值和参考价值 相似文献
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Tomasz Kozacki 《Optics Communications》2008,281(17):4219-4223
In the paper the numerical determination of diffraction patterns using plane wave spectrum decomposition (PWS) is investigated. The simple formula for sampling selection for error-free numerical computation is proposed and its applicability is discussed. The usage of this formula presents practical difficulty for some diffraction problems due to required large memory load. A new multi-Fourier transform PWS (MPWS) method is elaborated which overcomes memory requirement of the PWS method. The performances of the PWS and MPWS methods are verified through extensive numerical simulations. 相似文献
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建立了有阻尼项的摆方程,在小信号情况下,对方程进行了迭代求解.由解得的结果得到了增益函数的表达式.特别对弱阻尼和过阻尼情况进行了计算,分别得到了相应的增益函数简化公式.对阻尼项的来源和物理意义进行了详细的讨论.
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One of the most challenging features of underwater acoustic (UWA) channel in comparison with its terrestrial radio frequency counterpart is highly frequency-dependent path loss. Thus, utilizing efficient carrier frequencies in UWA systems can considerably reduce the path loss. In this context, this paper presents an approximate formula for determining the best carrier frequency based on both the system and environmental parameters. To achieve this goal, this research first addresses a simple algorithm including general steps for tuning the parameters of Francois and Garrison (FG) formula in the frequency range of 10 to 100 kHz based on the appropriate experimental data which can be acquired from any interest region. Second, for a more accurate modeling of path loss, this paper considers the loss due to the reflections of sound from both the rough surface and bottom of the sea by employing the ray theory. Third, this study presents a general algorithm for modification of the power spectral density (PSD) of ambient noise based on Wenz formula in the frequency range of 10 to 100 kHz and the required experimental measurements which can be simply collected from any interest channel. Moreover, it is mathematically demonstrated that the ambient noise in the frequency range of 10 to 100 kHz, can be generally approximated with a strict sense stationary (SSS) colored normal stochastic process which is ergodic not only in mean and covariance but also in distribution. Finally, an approximate formula for the best carrier frequency is derived by maximizing the sound to noise intensity ratio (SNR). To verify the validity of simplifications and approximations utilized in this study and to assess the performance of our proposed algorithms and formulas, experimental results obtained in the Strait of Hormuz (SoH) are compared with the original, simplified, and modified models under different scenarios. 相似文献
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Karl Kummerer 《Zeitschrift für Physik A Hadrons and Nuclei》1962,169(1):166-177
For the evaluation of float measurements all individual steps of the calculations are comprised under the expression of “precise float formula”. From this simplified approximations can be deduced. Their errors are estimated under little restraining conditions. The rather simple “difference formula” in the range of high D2O-concentration together with a density scale for pure D2O gained by interpolation suffice for most practical purposes. This is proved by numerical comparing with the precise formula. 相似文献