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81.
82.
X.F. Hu 《Applied Surface Science》2006,252(13):4625-4627
The synthetic antiferromagnets (SAF) have been used in spin-valve sensor in data storage industry [1]. We report a new hard/Ru/soft sandwich structure (SHBL) fabricated by pulsed lased deposition to replace current single layer structure for information recording application. SHBL consists of two magnetic layers separated by thin nonmagnetic layers, typically with Ru layers of 0.7-1.2 nm, through which antiferromagnetic coupling is induced. Varying the relative thickness of the magnetic layers, the spacer layers, and the type of magnetic materials can alter magnetic properties of CoCrPt/Ru/CoFe superlattice. The coercivity Hc and grain size of magnetic layer is also dependent on the laser fluence. High laser fluence results in both small grain size and high Hc. The observed phenomena are related to high quenching and deposition rates during PLD at high fluence, resulting in more pronounced phase segregation. 相似文献
83.
Hu Haiyan 《Acta Mechanica Solida Sinica》1994,7(2):137-150
This paper deals with the numerical solution of high dimensional dynamic systems with nonsmooth characteristics, such as structural elastoplasticity, mechanical clearance and dry friction. As a stable periodic response of the system attracts its transient response, it may be extracted from the transient response somehow. The paper suggests a novel iteration scheme to extrapolate the periodic response from a short time history of its transient response by curve fitting. Compared with the current schemes such as shooting and incremental harmonic balancing, the present scheme makes full use of the information within the transient response and the system characters, then its computation efficiency has increased by an order and the numerical convergence depending on the initial iteration has greatly improved.The subject supported by the Chinese Foundation of Aeronautical Science 相似文献
84.
Indirect and direct boundary integral equations equivalent to the original boundary value problem of differential equation of plane elasticity are established rigorously. The unnecessity or deficiency of some customary boundary integral equations is indicated by examples and numerical comparison. 相似文献
85.
气体放电击穿过程的物理和数值研究 总被引:1,自引:0,他引:1
胡希伟 《核聚变与等离子体物理》1994,14(1):44-50
本文对低气压(10^-2Pa)热阴极气体放电的击穿过程给出了物理描述和相应的双流体数学型,并发展了一种选择和调整未知初始条件的有效算法,可以通过伴随试射法得到对初始条件十分敏感的非线性两点边值常微分方程组的数值解,从而给出这类气体放电中击穿过程的定量描述。 相似文献
86.
线性嵌套阵可以很好地在很宽的频率(N个倍频程,N=7)上实现恒定束宽。这种方法设计简单,又节省线阵阵元。本文给出了线性嵌套阵具体的数字化实现方法,解决了FIR滤波器设计,滤波器时间延迟等问题。由于数字化实现过程中使用了很多组FIR滤波器,计算量很大,文章采用了DSP信号处理板实现数字化算法,利用DSP处理板可以多任务同时处理优势,解决了计算量大的问题。经过实验验证,在DSP上实现的数字化的线性嵌套阵宽带恒定束宽方法满足了工程上实时处理的需要。 相似文献
87.
The study of bed-load transport is of great significance both in theory and in practice. This paper discusses the saltation
of bed-load solid grains in flowing water. Experiments and theoretic analysis have been made by means of high-speed photographing
and advanced data processing technique with a combined method based on mechanical and statistical theories. It indicates that
the saltation is the main form of the bed-load transport under ordinary flowing conditions. In the meantime, taking successive
saltation as the model of bed-load transport, systematic analysis has been made with regard to the kinematic properties and
mechanism of saltation. The statistical analysis shows that the probability density functions of the relative height and length
of saltation are in conformity with Γ-type distribution, while the probability density functions of the relative velocities
of saltation are in conformity with the Gaussian distribution.
The project supported by National Natural Science Foundation of China 相似文献
88.
Hu Gang 《Zeitschrift für Physik B Condensed Matter》1986,64(2):247-252
The master equation and the Fokker-Planck equation are compared thoroughly in both of the stationary and the time-dependent cases for a one-dimensional system. The comparison includes the master equation without detailed balance. 相似文献
89.
纯生跳跃扩散型交换期权定价公式 总被引:1,自引:0,他引:1
在假定标的资产价格服从纯生跳跃过程的条件下,研究一类多资产期权——资产权重不同的交换期权,并在风险中性的条件下建立相应的定价方程,运用条件期望等相关知识得出交换期权的解析公式。文中最后列出一些特殊纯生跳跃扩散型交换期权的定价的例子. 相似文献
90.
Three-dimensional astigmatic resonators, typical examples of which are the resonators bounded by cylindrical-spherical mirrors and cylindrical-cylindrical mirrors oriented at an arbitrary crossed angle, are investigated in detail by using a complex curvature tensor concept and generalized tensor ABCD law. Computerized numerical calculations illustrate some interesting characteristics of these astigmatic resonators. 相似文献