共查询到20条相似文献,搜索用时 78 毫秒
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使用微波回旋共振离子源,研究Ar+离子束在不同角度、不同入射能量下对蓝宝石表面的刻蚀效果及光学性能。结果表明:所用能量800 eV,1 000 eV及1 200 eV时透过率都有很大的提升,由原来的50%提高到70%~80%,在能量为1 000 eV时增幅最大,能量为1 200 eV时增幅最小;在相同能量、不同角度下刻蚀后蓝宝石粗糙度呈先增大后减小的趋势,而在相同角度、不同能量下粗糙度方面无明显规律。刻蚀后表面形貌测试表明:角度不变,能量为1 000 eV时出现点状纳米结构,能量为1 200 eV时出现柱状纳米结构;能量不变,角度为10、50及80时出现了规律较明显的点状或条状纳米结构,角度为30时表面较为光滑。 相似文献
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本文在有效质量近似下,通过自洽地求解薛定鄂方程及泊松方程计算了在温度T=273 K,磁感应强度B=25 T,Si均匀掺杂的GaAs/AlGaAs量子阱系统的电子态结构.研究了温度与外磁场对子带能量,本征包络函数,自洽势,电子密度分布,及费米能量的影响.发现在给定磁感应强度B=fi0下,随温度升高子带能量单调增加,费米能量单调递减,自洽势的势阱变深变陡,电子密度分布变宽,峰值降低;在给定温度下,随磁感应强度的增加子带能量及费米能量单调递增,自洽势阱变浅变宽,电子密度分布变窄,峰值升高. 相似文献
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本文叙述了在神光装置中测量激光能量的体吸收能量计的特点,给出了其工作参数。实测了神光装置中激光系统末级输出能量、激光系统前部和中部定点发射能量及激光系统放大的自发辐射能量。并作了分析和讨论。 相似文献
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基于蒙特卡罗软件Geant4,探讨质子与硅的库仑散射和核反应及中子与硅的核反应产生反冲原子沉积非电离能量的过程,建立质子和中子在硅中的非电离能量阻止本领计算方法。在此方法中,描述了原子间库仑散射的物理过程,模拟带电粒子与晶格原子之间的屏蔽库仑散射。计算得到不同能量质子和中子在硅中因库仑散射和核反应产生反冲原子的非电离能量沉积及阻止本领的等效性,计算结果与中子ASTM标准及文献计算得到的质子数据符合很好。 相似文献
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在综述电化学近50年来比能量提高情况的基础上,讨论了现代科技发展对电池比能量的要求,以及当今电池能在多大程度上满足这些要求,并讨论了进一步提高电池比能量的可能性及可能途径. 相似文献
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本工作使用高分辨快电子能量损失谱仪,在入射电子能量1 500 eV、能量分辨200 meV和散射角度0.5°~ 4.0°的实验条件下,测量了氦原子在电离连续区24.5~28.5 eV的双重微分散射截面.通过与理论及其它入射能量实验结果的比较,认为在入射电子能量为1 500 eV 时一阶Born近似成立. 相似文献
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根据原型装置主放大系统组合式四程放大结构的特点,计算分析了放大过程中注入能量、放大增益及损耗的微小起伏对系统输出能量稳定性的影响。根据原型装置集成实验结果,分析了目前原型装置单路输出能量稳定性水平。研究结果表明:注入能量越大,其变化对输出能量影响越小;小信号增益系数对输出能量的影响明显大于注入能量;系统输出能量稳定性对腔内光学元件的透过率变化要求高于腔外光学元件。在3 ns基频光输出达标点处要使输出能量不稳定性控制在5%以内,注入能量起伏要低于10%,腔内放大片小信号增益系数起伏要低于1%,腔内光学系统损耗起伏要低于2%。 相似文献
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Changqing Xiang Cheng-Wei Wu Wu-Xing Zhou Guofeng Xie Gang Zhang 《Frontiers of Physics》2022,17(1):13202
In recent years, lithium ion (Li-ion) batteries have served as significant power sources in portable electronic devices and electric vehicles because of their high energy density and rate capability. There are growing concerns towards the safety of Li-ion batteries, in which thermal conductivities of anodes, cathodes, electrolytes and separator play key roles for determining the thermal energy transport in Li-ion battery. In this review, we summarize the state-of-the-art studies on the thermal conductivities of commonly used anodes, cathodes, electrolytes and separator in Li-ion batteries, including both theoretical and experimental reports. First, the thermal conductivities of anodes and cathodes are discussed, and the effects of delithiation degree and temperature of materials are also discussed. Then, we review the thermal conductivities of commonly used electrolytes, especially on solid electrolytes. Finally, the basic concept of interfacial thermal conductance and simulation methods are presented, as well as the interfacial thermal conductance between separator and cathodes. This perspective review would provide atomic perspective knowledge to understand thermal transport in Li-ion battery, which will be beneficial to the thermal management and temperature control in electrochemical energy storage devices. 相似文献
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A.Y. Vorobyev V.M. Kuzmichev N.G. Kokody P. Kohns J. Dai Chunlei Guo 《Applied Physics A: Materials Science & Processing》2006,82(2):357-362
A comparative study of residual thermal effects in aluminum following ns- and fs-laser ablation shows a surprisingly similar
trend in their behavior, despite many differences between ns and fs laser-matter interactions. At laser fluences above the
ablation threshold where plasmas are produced and at a sufficiently high ambient gas pressure, an enhanced coupling of pulsed
laser energy to the sample occurs. This effect appears to be a universal phenomenon for both ns- and fs-laser ablation in
gas media. Furthermore, in contrast to the common belief that residual thermal energy is negligible in fs-laser ablation,
our study shows that up to 70% of the incident pulse energy can be retained in the sample following single-pulse fs-laserablation
in 1-atm air. In both ns- and fs-laser ablation, the major factors governing thermal energy coupling to the sample are the
laser fluence and ambient gas pressure. Residual thermal energy deposition decreases with reducing ambient gas pressure.
PACS 78.20; 81.05.Bx 相似文献
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Behnam Pourhassan Mir Faizal Sudhaker Upadhyay Lina Al Asfar 《The European Physical Journal C - Particles and Fields》2017,77(8):555
In this paper, we study the effect of thermal fluctuations on the thermodynamics of a black geometry with hyperscaling violation. These thermal fluctuations in the thermodynamics of this system are produced from quantum corrections of geometry describing this system. We discuss the stability of this system using specific heat and the entire Hessian matrix of the free energy. We will analyze the effects of thermal fluctuations on the stability of this system. We also analyze the effects of thermal fluctuations on the criticality of the hyperscaling-violation background. 相似文献
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A. Umantsev 《Interface Science》2001,9(3-4):349-356
Dynamical Ginzburg-Landau theory is applied to the study of thermal effects of motion of interfaces that appear after different phase transitions. These effects stem from the existence of the surface internal energy, entropy and temperature gradients in the interfacial transition region. Evolution equations for the interfacial motion are derived. For the experimental verification of the thermal effects the expression is derived for the amplitude of temperature waves during continuous ordering. 相似文献
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In this paper, the energy flow analysis (EFA) method is developed to predict the high-frequency response of beams in a thermal environment, which is a topic of concern in aerospace and automotive industries. The temperature load applied on the structures can generate thermal stresses and change material properties. The wavenumber and group velocity associated with the in-plane axial force arising from thermal stresses are included in the derivation of the governing energy equation, and the input power is obtained from the derived effective bending stiffness. In addition, effect of temperature-dependent material properties is considered in the EFA model. To verify the proposed formulation, numerical simulations are performed for a pinned–pinned beam in a uniform thermal environment. The EFA results are compared with the modal solutions for various frequencies and damping loss factors, and good correlations are observed. The results show that the spatial distributions and levels of energy density can be affected by the thermal effects, and the vibration response of beams increases with temperature. 相似文献
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Michael J. Aziz 《Applied Physics A: Materials Science & Processing》2008,92(3):579-587
This paper reviews our recent studies of the fundamentals of growth morphology evolution in Pulsed Laser Deposition in two
prototypical growth modes: metal-on-insulator island growth and semiconductor homoepitaxy. By comparing morphology evolution
for pulsed laser deposition and thermal deposition in the same dual-use chamber under identical thermal, background, and surface
preparation conditions, and varying the kinetic energy by varying the laser fluence or using an inert background gas, we have
isolated the effect of kinetic energy from that of flux pulsing in determining the differences between morphology evolution
in these growth methods. In each growth mode analytical growth models and Kinetic Monte Carlo simulations for thermal deposition,
modified to include kinetic energy effects, are successful at explaining much of what we observe experimentally. 相似文献
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从小尺度热晕线性理论出发,在non-Kolmogorov谱的基础上,得到了non-Kolmogorov谱湍流下热晕相位补偿的Strehl比表达式,分析了湍流谱对高能激光的相位补偿的影响.研究结果表明湍流谱对湍流热晕效应的相位补偿有重要的影响.在相同的湍流菲涅耳数下,当谱指数越接近于3时补偿效果越差,谱指数接近于4时补偿效果越好.在相同大气相干长度条件下或在相同湍流折射率常量条件下,当谱指数接近于3时,Strehl比随热晕效应的增强而下降变快,当湍流谱指数逐渐接近于4时,Strehl比下降速度变慢.其原因是随着湍流谱指数的增大,湍流热晕相互作用引起的对数振幅起伏增长变慢. 相似文献
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We report on thermal expansion measurements at low temperatures of pure Y and
RE (RE: Er, Dy, Tb and Gd) single crystals. We estimate the electronic and lattice contributions for the thermal expansion of pure yttrium. For the dilute
RE alloys, the thermal expansion exhibits crystal field effects. These are explained with a free energy including crystal field, elastic and magnetoelastic terms. 相似文献
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