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151.
A new approach for tree-level amplitudes with multiple fermion lines is presented. It primarily focuses on the simplification of fermion lines. By calculating two vectors recursively without any matrix multiplications, the result of a fermion line is reduced to a very compact form depending only on the two vectors. Comparisons with other packages are presented, and the results show that our package FDC provides a very good performance in the processes of multiple fermion lines with this new approach and some other improvements. A further comparison with WHIZARD shows that this new approach has a competitive efficiency in computing pure amplitude squares without phase space integration. 相似文献
152.
Jean Richert 《Physica B: Condensed Matter》2012,407(4):729-734
The propagation of an external transverse magnetic signal acting locally on a 1d chain of spins generates a disturbance which runs through the system. This quantum effect can be interpreted as a classical travelling wave which contains a superposition of a large set of frequencies depending on the size of the chain. Its local amplitude fixes the size of the z-component of the spins at any location in the chain. The average and maximum value of the group velocity are determined and compared with the transmission velocity fixed by the Lieb-Robinson upper bound inequality. 相似文献
153.
154.
针对中国散裂中子源快同步环上束团纵向长度和束流强度的测量工作以及973束流损失控制实验课题中束团时间结构的测量工作,研制了用于上述两台质子加速器的壁电流探头。介绍了使探头达到足够的带宽所做的改进工作。用高频电磁场仿真软件对探头的性能进行了模拟,验证了适用于壁电流探头的一些理论模型和加入屏蔽腔对探头高频响应曲线产生的影响以及做出相应的改进后所带来的效果。对实物探头的性能进行了测量实验,发现测量系统自身的不匹配对实验结果产生了影响,改进匹配后得到探头的幅频响应曲线在300 kHz~2 GHz的频率范围内基本保持一致。时域上对500 ns脉冲矩形波的测量结果也显示出探头良好的低频响应。 相似文献
155.
156.
The growing interest in sonochemistry as a tool for environmental remediation leads to the need for process optimization. Sonochemistry is a complex process, which depends on physical parameters and also on the process conditions. Physical parameters are interrelated and therefore a systematic approach has to be taken to optimize the process. The effect of physical parameters on the destruction of seven estrogen hormones (17α-estradiol, 17β-estradiol, estriol, 17α-ethinylestradiol, 17α-dihydroequilin, estrone and equilin) is reported in this study. Artificial neural networks (ANN) was used as a tool to identify the correlations between these process parameters. ANN enabled the establishment of relationship between sonication parameters such as power density, power intensity, ultrasound amplitude, as well as the reactor design parameters. The major significance was attributed to the area-specific power density and the volume-specific power intensity. The results of this work provide a sound basis to design pilot and full-scale ultrasound treatment systems. Process optimization lead to a 5-fold decrease in energy consumption as compared to the commercially available reactors, thereby making the process attractive for field applications. 相似文献
157.
岩石破裂电磁辐射幅值与岩石属性参数的关系 总被引:1,自引:0,他引:1
基于岩石破裂电磁辐射是由岩石破裂时传播裂纹引起原子扰动产生的假说,
通过断裂力学理论计算了岩石破裂时的裂纹扩展长度及裂纹面积. 由电磁辐射幅值与裂纹长度
及裂纹面积之间的关系,给出了电磁辐射幅值与岩石属性参数之间的关系表达式. 讨论了主
要的不同属性参数对电磁辐射幅值的影响. 发现电磁辐射幅值随岩石弹性模量增大而增大;岩石破
裂的电磁辐射与岩石的尺寸有关,且岩石尺寸因素影响大于岩性因素影响. 本文的研究结果与现有的
实验结果是吻合的. 相似文献
158.
A new tracking error detection method using amplitude difference detection for signal waveform modulation multi-level discs
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The sub-land/sub-pit affects the characteristic of the tracking error signal which is generated by the conventional differential phase detection (DPD) method in the signal waveform modulation multi-level (SWML) read-only disc. To solve this problem, this paper proposes a new tracking error detection method using amplitude difference. Based on the diffraction theory, the amplitude difference is proportional to the tracking error and is feasible to be used for obtaining the off-track information. The experimental system of the amplitude difference detection method is developed. The experimental results show that the tracking error signal derived from the new method has better performance in uniformity and signal-to-noise ratio than that derived from the conventional DPD method in the SWML read-only disc. 相似文献
159.
Noisy teleportation of qubit states via the Greenberger-Horne-Zeilinger state or the W state
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The effects of distributing entanglement through the amplitude
damping channel or the phase damping channel on the teleportation of
a single-qubit state via the Greenberger--Horne--Zeilinger state and the W
state are discussed. It is found that the average fidelity of
teleportation depends on the type and rate of the damping in the
channel. For the one-qubit affected case, the
Greenberger--Horne--Zeilinger state is as robust as the W state,
i.e., the same quantum information is preserved through
teleportation. For the two-qubit affected case, the W state is more robust
when the entanglement is distributed via the amplitude damping
channel; if the entanglement is distributed via the phase damping
channel, the W state is more robust when the noisy parameter is
small while the Greenberger--Horne--Zeilinger state becomes more
robust when it is large. For the three-qubit affected case, the
Greenberger--Horne--Zeilinger state is more robust than the W
state. 相似文献
160.
ZHOUTian-Shou ZHANGSuo-Chun 《理论物理通讯》2001,35(6):657-660
We theoretically analyze the organizing filament of small amplitude scroll waves in general excitable media by perturbation method and explicitly give the expressions of coefficients in Keener theory.In particular for the excitable media with equal diffusion,we obtain a close system for the motion of the filament.With an example of the Oregonator Model,our results are in good agreement with those simulated by Windree. 相似文献