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71.
采用高效液相色谱法对斑头雁卵、肌肉和羽毛中17种氨基酸进行了含量的测定,并分析其中必需氨基酸的含量,为斑头雁的保护和利用提供依据。结果表明,斑头雁的卵、腿肌、胸肌和羽毛中均含有17种氨基酸,必需氨基酸含量较高,配比合理,有较高的营养价值。  相似文献   
72.
This paper presents a multi-functional all-optical device performs simultaneous chromatic dispersion (CD) monitoring, extinction ratio (ER) improvement and tunable wavelength conversion using four-wave mixing (FWM) in a single piece of highly nonlinear optical fiber (HNLF). The multi-functional ability arises from the nonlinear power transfer function (PTF) between the input signal and the output idler wave, which not only maps the CD information of the signal onto the average power of idler wave, but also transfers the data information to the idler wave with ER enhancement, making the device compact and cost effective. Furthermore within the wavelength tuning range the monitoring sensitivity and output ER can be much higher compared to all optical monitors and regenerators proposed before. Numerical simulations are then used to demonstrate the efficiency of this method.  相似文献   
73.
黄家辉  盛正卯 《中国物理 B》2010,19(1):10316-010316
This paper uses the background field method to calculate one-loop divergent corrections to the gauge field propagators in noncommutative U(1) gauge theory with scalar fields. It shows that for a massless scalar field, the gauge field propagators are renormalizable to θ2-order, but for a massive scalar field they are renormalizable only to θ-order.  相似文献   
74.
The angular distribution of the 12C(7Li,6He)13N reaction at E(7Li) = 44.0 MeV was measured at the HI-13 tandem accelerator of Beijing, China. The asymptotic normalization coefficient (ANC) of 13N → 12C + p was derived to be (1.64 ± 0.11) fm-1/2 through the distorted wave Born approximation (DWBA) analysis. The ANC was then used to deduce the astrophysical S (E) factors and reaction rates for the 12C(p,γ)13N direct capture reaction at energies of astrophysical relevance.  相似文献   
75.
针对DV-Hop定位算法在节点随机分布的网络拓扑环境下存在误差较大的问题,文中通过分析平均跳距估计、未知节点坐标估计区域求解对定位精度的影响,提出了一种基于跳距修正L-M优化的WSN定位算法CLDV-Hop(Correct L-M DV-Hop)。仿真结果表明,在不增加额外开销且仿真环境相同的条件下,CLDV-Hop算法比现有改进的算法具有更高的定位精度,与DV-Hop算法相比精度提高了约33%——41%。  相似文献   
76.
耿丽  屈胜 《应用声学》2019,38(6):969-979
目前,全面屏手机已经成为一种趋势。为提升全面屏的用户体验效果,业界开发了屏下指纹识别、伸缩式摄像头等技术,对于音频(主要是语音通话),则开发了基于压电陶瓷和电磁激励器的两种屏幕发声方案,其代表产品分别为小米MIX与VIVO NEX。该文针对电磁激励器屏幕发声技术,分别从平板弯曲振动、平板声辐射、电磁激励器阵列驱动等模型出发,推导电磁激励器驱动屏幕振动发声的原理以及简化的力电类比等效线路图;给出仿真与实测频响曲线以及某型号手机语音通话测试数据;最后简要归纳电磁激励器屏幕发声的设计指南以及进一步的研究方向。  相似文献   
77.
Sheng Liu 《哲学杂志》2013,93(29):3382-3397
The escaped probability density of the photo-detached electron in an annular nanomicrocavity shows strong oscillations as a function of the length of the escape orbits. We present a semiclassical theory that describes theses oscillations in terms of bundles of escape orbits. Due to the interference effects of the electron waves travelling along different escaped orbits, oscillatory structures appear in the escaped probability density. In addition, the calculation results suggest that the escaped probability density of the photo-detached electron is not only related to the inner radius of the annular microcavity, but also related to the laser polarization. In order to show the correspondence between the escaped probability density and the detached electron’s escaped orbits clearly, we calculate the Fourier transformed semiclassical wave function and find that the peak positions agree well with the length of the detached electron’s orbits. We hope that our results will be useful in understanding the escape and propagation process of particles through semiconductor microjunctions or ballistic microstructure.  相似文献   
78.
The directional drifting of particles/molecules with broken symmetry has received increasing attention. Through molecular dynamics simulations, we investigate the effects of various solvents on the time-dependent directional drifting of a particle with broken symmetry. Our simulations show that the distance of directional drift of the asymmetrical particle is reduced while the ratio of the drift to the mean displacement of the particle is enhanced with increasing mass, size, and interaction strength of the solvent atoms in a short time range. Among the parameters considered, solvent atom size is a particularly influential factor for enhancing the directional drift of asymmetrical particles, while the effects of the interaction strength and the mass of the solvent atoms are relatively weaker. These findings are of great importance to the understanding and control of the Brownian motion of particles in various physical, chemical, and biological processes within finite time spans.  相似文献   
79.
In this paper, we present a unified finite volume method preserving discrete maximum principle (DMP) for the conjugate heat transfer problems with general interface conditions. We prove the existence of the numerical solution and the DMP-preserving property. Numerical experiments show that the nonlinear iteration numbers of the scheme in [24] increase rapidly when the interfacial coefficients decrease to zero. In contrast, the nonlinear iteration numbers of the unified scheme do not increase when the interfacial coefficients decrease to zero, which reveals that the unified scheme is more robust than the scheme in [24]. The accuracy and DMP-preserving property of the scheme are also veried in the numerical experiments.  相似文献   
80.
针对专用集成电路(ASIC)设计中功能验证的效率和完备性问题,以验证方法学手册(VMM)为基础搭建了串行高级技术附件(SATA)控制器分层式验证平台.验证组件的实现大量重用验证知识产权核(VIP),在采用随机激励的基础上以覆盖率统计驱动验证的过程,根据SATA控制器的功能设计记分牌进行结果的自动化比对.实验结果表明,这些方法提高了功能验证的效率,保证了验证的完备性,最终功能覆盖率达到98.25%.  相似文献   
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