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提出了一种利用单光束照明二元π相位板与透镜组合系统实现冷原子或冷分子囚禁的可控制光学四阱新方案.计算了四阱的光强分布,讨论了从光学四阱到双阱或到单阱的演化过程,并导出了四阱和双阱几何参数、光强分布、强度梯度及其曲率与光学透镜系统参数间的解析关系.研究表明,通过相对移动二元π相位板可实现光学四阱到双阱或到单阱的连续双向演化,获得了四阱或双阱间距与相位板移动距离的关系.该方案在超冷原子物理、冷分子物理、原子光学、分子光学和量子光学,甚至量子计算及信息处理等领域中有着广阔的应用前景.
关键词:
二元π相位板
可控制光学四阱
原子分子囚禁
原子光学 相似文献
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提出了一种利用单束平面光波照明二元订相位板与透镜组合系统实现冷原子或冷分子囚禁的可控制光学八阱的新方案,计算与分析了该方案产生的势阱光强分布和八阱的特征参数、强度梯度及其曲率,讨论了从光学八阱到四阱或到双阱的演化过程。研究表明通过相对移动二元订相位板可实现光学八阱到四阱或到双阱的连续双向演化。该方案在超冷原子物理、冷分子物理、原子光学、分子光学与量子光学甚至量子计算与信息处理等领域中有着广阔的应用前景。 相似文献
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基于计算流体力学(CFD)理论,研究了不同曲率半径的螺旋导流片的托卡马克真空室内线圈水冷管道接头。利用湍流数值模拟方法,分析了线圈管道接头导流片曲率半径比、冷却水入口流速对线圈管道内流体平均雷诺数分布的影响。结果表明,不同导流片曲率半径比的线圈管道内的流体雷诺数分布曲线相似,平均雷诺数随入口流速的增加而增大,管道接头出口雷诺数随导流片曲率半径比的增大而减小,导流片曲率半径比小的管接头更适用于线圈水冷曲线管的二次流强化。此外,还为导流片曲率半径比为0.2的管接头拟合了管接头出口雷诺数与入口流速的关系式,为进一步研究类似于托卡马克真空室内线圈管道的曲线管接头的二次流强化提供理论基础。 相似文献
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运用FLUNET软件对ITER屏蔽模块上的前集箱进行了数值模拟计算。计算结果表明,前集箱盖板存在冷却不均匀和冷却不够充分的问题。根据数值模拟的结果,对前集箱中的导流板进行了改进,并给出了改进后导流板的几何尺寸和结构。改进后的数值分析结果表明,采用改进后的T型导流板,前集箱盖板的冷却可以满足ITER的要求。 相似文献
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提出了一种采用单光束照明二元π相位板与透镜组合系统产生的适用于冷原子与分子囚 禁的可控制光学双阱方案.计算了双阱的光强分布,研究了双阱到单阱的演化过程,并导出了双阱几何参数、光强分布、强度梯度及其曲率与光学系统参数间的解析关系.研究发现, 通过相对移动二元相位板可实现光学双阱到单阱的连续双向演化,得到了双阱间距与相位板移动距离的关系.该方案不仅简单可行、操作方便,而且在原子物理、原子光学、分子光学和量子光学领域中有着广阔的应用前景.
关键词:
二元相位板
可控制光学双阱
原子囚禁
原子光学
分子光学 相似文献
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提出了一种新颖的实现冷原子(或冷分子)囚禁的可控制纵向光学双阱方案,它由一个二元π相位板及一会聚透镜所组成,其π相位板由两个面积相等的具有0和π相位的同心圆环组成. 当一平面光波通过此光学系统时将在光轴上透镜焦点两侧形成一个光学双阱,如果调节入射到二元π相位板上光束横截面的半径大小,即可实现从光学双阱到单阱的连续演变,或由单阱到双阱的连续变化. 介绍了本方案产生可控制光学双阱的基本原理,给出了形成光学双阱的最佳几何参数,研究了双阱、单阱及其演化过程的光阱参数、光强分布等与光学系统参数间的关系. 该方案不仅可用于双样品原子(分子)的光学囚禁及其全光型玻色-爱因斯坦凝聚(BEC)的实现,而且可用于研究超冷原子(或分子)物质波的干涉,或构成双层2D光阱列阵,甚至用于制备新颖的双层2D光学晶格.
关键词:
二元π相位板
可控制光学双阱
双样品囚禁
光学晶格 相似文献
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《中国光学与应用光学文摘》2006,(4)
O43 2006042812实现冷原子或冷分子囚禁的可控制光学四阱=Controlla-ble four-well optical trap for cold atoms or molecules[刊,中]/陆俊发(华东师范大学物理系,光谱学与波谱学教育部重点实验室.上海(200062)) ,纪宪明…∥物理学报.—2006 ,55(4) .—1740-1750提出了一种利用单光束照明二元π相位板与透镜组合系统实现冷原子或冷分子囚禁的可控制光学四阱新方案。计算了四阱的光强分布,讨论了从光学四阱到双阱或到单阱的演化过程,并导出了四阱和双阱几何参数、光强分布、强度梯度及其曲率与光学透镜系统参数间的解析关系。研究表明,通过… 相似文献
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A compound expansion-chamber muffler, which consists of a sound absorbing chamber and a switch valve, the chamber integrating structural features of impedance muffler and micropunch plate muffler, is proposed to diminish impulse exhaust noise of pneumatic friction clutch and pneumatic friction brake (PFC/B) in mechanical presses. The structure decreases the impulse exhaust noise of PFC/B over 30 dB(A). A one-dimensional flow model is applied to study the aerodynamic characteristics of compound exhaust process of the single acting cylinder and muffler because the exhaust time is a critical factor for application of muffler in PFC/B. The volume of sound absorbing chamber is found to be an important design parameter to minimize the exhaust resistance of pneumatic cylinder. Experiments are also conducted to validate analytical results. Then the effects of diameter of exhaust ducts and volume of muffler on the exhaust time are discussed in detail. The proposed one-dimensional computational method, which considers the coupling of air-flow field and sound field, gives satisfactory results for the preliminary design of an expansion-chamber muffler. This method has been applied to an existing model HKM3-40MN to reduce its impulse noise. 相似文献
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D. A. Vnuchkov V. I. Zvegintsev D. G. Nalivaichenko V. I. Smolyaga A. V. Stepanov 《Thermophysics and Aeromechanics》2018,25(4):605-611
A design of an axisymmetric solid fuel ramjet consisting of a multi wedges nose air intake, solid fuel gas gene-rator, combustion chamber, and a nozzle, was developed. According to this design, a ramjet model for tests in the ground wind-tunnel facilities was fabricated. Experiments with solid fuel combustion were carried out in the Transit-M and T-313 wind tunnels, ITAM SB RAS, at air-flow Mach numbers М = 2.5?5.0. High values of the internal and net excess thrust were obtained. 相似文献
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Dragonetti R Ianniello C Romano RA 《The Journal of the Acoustical Society of America》2011,129(2):753-764
Air-flow resistivity is a main parameter governing the acoustic behavior of porous materials for sound absorption. The international standard ISO 9053 specifies two different methods to measure the air-flow resistivity, namely a steady-state air-flow method and an alternating air-flow method. The latter is realized by the measurement of the sound pressure at 2 Hz in a small rigid volume closed partially by the test sample. This cavity is excited with a known volume-velocity sound source implemented often with a motor-driven piston oscillating with prescribed area and displacement magnitude. Measurements at 2 Hz require special instrumentation and care. The authors suggest an alternating air-flow method based on the ratio of sound pressures measured at frequencies higher than 2 Hz inside two cavities coupled through a conventional loudspeaker. The basic method showed that the imaginary part of the sound pressure ratio is useful for the evaluation of the air-flow resistance. Criteria are discussed about the choice of a frequency range suitable to perform simplified calculations with respect to the basic method. These criteria depend on the sample thickness, its nonacoustic parameters, and the measurement apparatus as well. The proposed measurement method was tested successfully with various types of acoustic materials. 相似文献
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W. Neise 《Journal of sound and vibration》1975,43(1):53-60
Measurements were made to determine the effect of air-flow on the sensitivity of microphone phobes. Standard condenser microphones fitted with either a standard nose cone or a slit-tube were investigated. A slit-tube is a special device to suppress the turbulent noise signal when sound measurements are to be made within a flow. The experiments show that there is a loss of the acoustic sensitivity due to the air-flow. However, the mean sensitivity loss is less than 0·5 dB up to 40 m/s and within a frequency range from 40 Hz to 1250 Hz. Therefore the loss in sensitivity may be neglected for most practical measurements. 相似文献
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A zeolite plate with push contacts is placed in a chamber filled with air at a controllable pressure, and the current-voltage characteristics of the zeolite plate are measured as a function of the air pressure in the chamber. It is found that the gas in zeolite pores ionizes and, accordingly, the number of electrons in the pores grows. It is shown that such a plate used as a cathode in a planar gas-discharge cell considerably reduces the ignition voltage of the gas discharge. 相似文献
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Ernesto Lopez 《Journal of sound and vibration》2011,330(4):685-702
Free vibration analysis of a thin tensioned plate, wrapped around a cylindrical guide in a helical manner is presented. The system is a model of a thin, flexible web wrapped around a turn-bar. The equation of motion of the wrapped plate is derived by using the energy method and with the Kirchhoff-Love assumptions. The weak form of the equation of motion was obtained by the finite element method and the eigenvalue problem was solved numerically. The effects of parameters such as plate tension, guide radius, longitudinal and helical wrap angles, plate width, and the lengths of the non-wrapped segments were investigated. Eigenmodes with same mode numbers were observed in symmetric and anti-symmetric fashion about the center of the plate, for symmetrically wrapped plates. It was shown that the plate/shell boundary of the wrapped plate effectively acts like a support. For non-helically wrapped plates the free edges cause a frequency clustering of the lateral modes about the dominant longitudinal mode. The frequency clustering diminishes when helical wrap is introduced. 相似文献
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从背光模组的基本结构出发,通过理论分析确定了影响导光板散射网点排布的公式,证明了散射网点的排布规律对背光模组出光均匀度有影响。对一款背光模组商品建立了简化模型,通过光学软件TracePro模拟分析以及实验验证,证明了背光模组商品的出光均匀度还有提升的可能性。在此基础上,又重点分析了散射网点行间距的变化值,散射网点直径和散射网点初始行间距对导光板出光均匀度的影响。经过反复仿真模拟,取得了一组参数值,可以使优化后的导光板出光均匀度比背光模组商品的出光均匀度好。研究的结论可作为导光板散射网点设计的参考,对背光模组的设计具有指导意义。 相似文献
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This article experimentally investigates the thermal performance of the vapor chamber module applied to the high-power light-emitting diodes in natural convection. The flat-plate-type vapor chamber and the lamp-type vapor chamber are provided to solve the heat dissipation problem of the high-power light-emitting diodes. The results show that the spreading resistance and the corresponding temperature difference of the flat-plate-type vapor chamber at 30 W are lower than those of the copper plate by 34% and 4°C, respectively, and are lower than those of the aluminum plate by 56% and 6°C, respectively. Compared with the copper and aluminum plates, the lamp-type vapor chamber at 15 W is reduced about 8% and 12% for the total thermal resistance, respectively. In addition, it is also about 3°C and 5°C lower for the central wall temperature of the lighting side, respectively. This study provides a new thermal management method to solve the heat dissipation of the high-power light-emitting diodes. Furthermore, the vapor chamber can effectively lower the spreading resistance and diminish the hotspot effect. 相似文献