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考虑空气阻力时铅球最佳投掷角的参数方程和实用方程 被引量:8
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作者 蔡志东 陆建隆 《大学物理》 北大核心 2006年第10期16-22,共7页
指出了一些文章在讨论有空气阻力作用时关于球类运动的微分方程中存在的问题,得出了空气阻力与速度平方成正比时的微分方程及近似解,计算了最佳投掷角的参数方程,还导出了空气阻力与速度成正比时铅球最佳投掷角的实用方程.
关键词 变系数微分方程 近似解 参数方程 最佳投掷角 实用方程
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同步发电机电磁暂态过程的实用方程 被引量:6
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作者 陈亚民 《电力系统及其自动化学报》 CSCD 1995年第3期18-25,共8页
本文根据派克方程导出一组描述同步发电机电磁暂态过程的实用方程。这组方程计及转子转速变化对发电机电势的影响。用这组方程分析计算电力系统电磁暂态过程和机电暂态过程可以提高计算精度。
关键词 同步发电机 电磁暂态过程 实用方程 计算
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低纬度磁异常波数域化极方法机理分析与功能定位 被引量:3
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作者 柴玉璞 万海珍 《石油地球物理勘探》 EI CSCD 北大核心 2020年第4期931-937,706,共8页
基于化极算法误差方程,对三类波数域低纬度化极方法进行机理分析和功能定位。压制型化极法不能用于低纬度磁异常数据的定量解释,但可用于定性解释;反演化极法理论上可用于定量解释,但要求资料窗外的未知数据很好地被模拟(实测资料难以满... 基于化极算法误差方程,对三类波数域低纬度化极方法进行机理分析和功能定位。压制型化极法不能用于低纬度磁异常数据的定量解释,但可用于定性解释;反演化极法理论上可用于定量解释,但要求资料窗外的未知数据很好地被模拟(实测资料难以满足),因此不具有实用性;偏移抽样化极法理论上也可以用于定量解释,但该方法要求磁偏角方向上的数据(网格数)不超过64,且数据相对精度不低于0.2%。三类波数域低纬度化极方法的功能定位,可对低纬度磁测资料的解释发挥重要的指导作用。 展开更多
关键词 实用化极算法误差方程 波数域 压制型化极方法 反演化极方法 偏移抽样化极方法
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Influence of crystallographic orientation on growth behavior of spherical voids
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作者 张新明 刘文辉 +1 位作者 唐建国 叶凌英 《Journal of Central South University of Technology》 EI 2008年第2期159-164,共6页
The influence of crystallographic orientation on the void growth in FCC crystals was numerically simulated with 3D crystal plasticity finite element by using a 3D unit cell including a spherical void, and the rate-dep... The influence of crystallographic orientation on the void growth in FCC crystals was numerically simulated with 3D crystal plasticity finite element by using a 3D unit cell including a spherical void, and the rate-dependent crystal plasticity theory was implemented as a user material subroutine. The results of the simulations show that crystallographic orientation has significant influence on the growth behavior of the void. Different active slip systems of the regions around the void cause the discontinuity in lattice rotation around the void, and the corner-like region is formed. In the case of the void located at grain boundary, large heterogeneous deformation occurs between the two grains, and the equivalent plastic deformation along grain boundary near the void in the case of θ=45^o (θ is the angle between grain boundary direction and X-axis) is larger than the others. Large difference of orientation factor of the two grains leads to large equivalent plastic deformation along grain boundary, and the unit cell is more likely to fail by intergranular fracture. 展开更多
关键词 crystallographic orientation void growth crystal plasticity user subroutine finite element method
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An Utilitarianist Reading of Criminal Law
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作者 Joao Paulo Orsini Martinelli 《Sociology Study》 2014年第4期348-359,共12页
Utilitarianism is the branch of philosophy that studies the usefulness of an idea. Among the possible gains and losses, the balance must be positive to reach the intended utility. Criminal law is the most repressive b... Utilitarianism is the branch of philosophy that studies the usefulness of an idea. Among the possible gains and losses, the balance must be positive to reach the intended utility. Criminal law is the most repressive branch of legal system and therefore should be applied sparingly by the state. Its usefulness should be the protection of legal interests and minimal restriction of personal liberty. The lawmaker should seek the best way to achieve this utility with the choice of the most relevant legal interests and less repressive means before appealing to the criminal law. The legal interests protected by criminal law must be the most important ones for a social life in harmony and prohibited behaviors must be injurious or dangerous to those legal interests. The Rule of Law does not authorize criminal prohibitions without a minimum limit that allows citizens to behave according to their wishes, provided that does not harm the interests of other people. This is the calculation that legislator, judge, and interpreter should seek: more protection and less restriction to citizens. 展开更多
关键词 UTILITARIANISM legal interests personal liberty PROPORTIONALITY
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CONSTRUCTION OF THE ENCRYPTION MATRIX BASED ON CHEBYSHEV CHAOTIC NEURAL NETWORKS
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作者 Zou Ajin Wu Wei +1 位作者 Li Renfa Li Yongjiang 《Journal of Electronics(China)》 2012年第3期248-253,共6页
The paper proposes a novel algorithm to get the encryption matrix. Firstly, a chaotic sequence generated by Chebyshev chaotic neural networks is converted into a series of low-order integer matrices from which availab... The paper proposes a novel algorithm to get the encryption matrix. Firstly, a chaotic sequence generated by Chebyshev chaotic neural networks is converted into a series of low-order integer matrices from which available encryption matrices are selected. Then, a higher order encryption matrix relating real world application is constructed by means of tensor production method based on selected encryption matrices. The results show that the proposed algorithm can produce a "one-time pad cipher" encryption matrix with high security; and the encryption results have good chaos and auto-correlation with the natural frequency of the plaintext being hidden and homogenized. 展开更多
关键词 Neural network Encryption matrix CHAOS Tensor production
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