共查询到20条相似文献,搜索用时 31 毫秒
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Yoshiaki Hattori Shinobu Mukasa Hiromichi Toyota Shinfuku Nomura 《Current Applied Physics》2013,13(6):1050-1054
The electrical breakdown of microwave plasma in water was investigated between 1 and 30 kPa. The dependency of the ignition power for generating plasma on the size of coaxial electrode was measured. The ignition power decreases with a decrease of the diameter of the inner electrode. The behavior of microwave plasma in water was observed using a high-speed camera. The plasma ignites in a bubble generated by microwave heating. The model for calculating the electric field was created on the basis of the captured images of the bubble just before plasma ignition. The method presented can be used to visualize the electrical field distribution in the bubble. The electric field breakdown was calculated using the measured ignition power. The electric field breakdown of plasma in water is of the same order as gas phase plasma. 相似文献
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研究了球形目标之间的电磁相互作用,得到了目标二次散射场的表达式,给出了目标的复合散射场以及双站复合散射截面,并在Ku波段进行了数值仿真.结果表明:目标的尺寸对前向散射和后向散射均有较大的影响,周围目标的影响呈现出一定的周期性,二次散射随着目标间距的增大而减小,周围目标离前向散射方向越近,对前向散射的影响也越大.目标的二次散射场与一次散射场强度之比在10-4数量级以上.在研究多粒子的相互影响时,周围的粒子可近似看作尺寸一定的粒子.利用所得结果以及坐标变换可以研究三维体系内粒子间的电磁相
关键词:
散射截面
二次电磁散射
电磁相互作用 相似文献
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M. I. Ryazanov A. A. Tishchenko 《Journal of Experimental and Theoretical Physics》2006,103(4):539-545
The dielectric properties of a quasi-two-dimensional molecular monolayer are analyzed. The dielectric function of the monolayer is expressed in terms of molecular polarizability and monolayer characteristics. The expression is analogous to the well-known Clausius-Mossotti equation for three-dimensional systems. The response of the monolayer to an external field is calculated. The case of a planar array of nanoparticles is also considered. The solution is obtained in the framework of a local-field theory. 相似文献
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Antonio Zecca 《International Journal of Theoretical Physics》2000,39(2):377-387
The massless field equations for arbitrary spin in curved space-time arereconsidered. The general solution of the field equation in Robertson-Walkerspace-time that was previously determined is briefly discussed after explicitlyshowing that the Weyl spinor vanishes. The case of the Lemaître-Tolman-Bondispace-time is studied in detail. The general expression of the corresponding Weylspinor is obtained and some particular situations exploited. The spin-3/2 andspin-2 massless field equations are solved explicitly. The solutions are simplifiedby the existence of nontrivial algebraic constraints. The angular part of theequations is separated by the usual separation method and integrated directly.The other equations that are not separated in the radial and time dependence arereduced to a simple form. The results obtained are extended, as a consequenceof previous results, to the case of arbitrary spin. The solution of the general caseessentially reduces to the treatment of spin 3/2 and spin 2. 相似文献
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The mathematical model for a racetrack microtron with an output energy of 50 MeV is described. The number of orbits is five.
The increment of energy beam increase is 10 MeV per turn. The frequency rate of acceleration is four. One feature of the accelerator
is injection directly into the acceleration section with a rather low kinetic energy beam of 0.8–1 MeV. The parameters that
affect the capture region in the acceleration mode are determined. The region of capture is calculated. The basic properties
of the focusing system are studied. The conditions for the optimum passage of the beam are substantiated for all orbits. 相似文献
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The optically transparent nonlinear optical single crystals of l-alanine strontium chloride trihydrate (LASCT) were grown by slow evaporation solution growth method using water as solvent. The purity of the crystals was increased by the method of recrystallization. The grown crystals were analyzed by the single crystal X-ray diffraction pattern which proved that LASCT belongs to monoclinic crystal system. The presence of various functional groups and modes of vibrations were identified by FTIR spectroscopy. The optical absorption study confirms the suitability of the crystal for device applications. The thermal strength and the decomposition of the grown crystals were studied using TG/DTA analyses. The dielectric constant and dielectric loss measurements of the grown crystals at different frequencies of the applied field were measured and reported. The mechanical strength of the crystal is estimated by Vicker's hardness test. The nonlinear optical properties of the grown crystals were confirmed by second harmonic generation test which shows the suitability of NLO applications. 相似文献
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Maryam I. Daneshvar Guillermo A. Casay Gabor Patonay Malgorzata Lipowska Lucjan Strekowski Lawrence Evans III Leila Tarazi Abraham George 《Journal of fluorescence》1996,6(2):69-75
The design and application of a fluorescent fiber-optic immunosensor (FFOI) are reported. The FFOI is utilized for the detection of antibody/antigen binding within the near-infrared (NIR) spectral region. The technique is developed through the combined use of fiber-optic, semiconductor laser-excitation, fluorescence detection, NIR dye, and immunochemical techniques. The antibody is immobilized on the FFOI and utilized as a recognition component for trace amounts of specific antigen. The FFOI is constructed to utilize an antibody sandwich technique. The assay involves the immobilization of the capture antibody on the sensing tip of the FFOI followed by the exposure of the immobilized sensing tip to the antigen. The antigen-coated FFOI is then introduced to a second antibody previously labeled with the NIR dye. Typical measurements are performed in about 15 min. A semiconductor laser provides the excitation (780 nm) of the immune complex. The resulting emission is detected by a silicon photodiode detector (820 nm). The intensity of the resulting fluorescence is directly proportional to the concentration of the antigen. The sensitivity of the analysis reaches 10 ng/ml and the response time is 10–15 min. 相似文献
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采用蒙特-卡罗(Monte Carlo)方法, 模拟了激光烧蚀粒子输运动力学过程, 在环境气体压强为100 Pa的情况下, 研究了环境气体种类(He, Ne, Ar和假想气体等)对烧蚀粒子速度劈裂的影响. 研究结果表明, 在四种环境气体中传输的烧蚀粒子均出现了速度劈裂现象, 形成速度劈裂所需时间按He, Ne, 假想气体和Ar的次序减小. 还研究了环境气体分子的质量和半径对烧蚀粒子速度劈裂的影响, 形成速度劈裂所需时间随环境气体分子半径(或质量)增大而减小. 在假想气体中, 两速度峰强度相等时的强度最小. 结合欠阻尼振荡模型和惯性流体模型, 对劈裂的形成时间进行了解释. 所得结论可为进一步定量研究纳米晶粒生长机理提供基础. 相似文献
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《Journal of magnetism and magnetic materials》1987,68(2):171-176
The spin model of single domain ferromagnetic film is considered. Only the nearest-neighbor interactions are taken into account. The interactions depend on distances from surfaces. The external magnetic field is applied perpendicular to the easy axis lying in the plane of the film. The thermodynamic behaviour of the model is studied near the second-order ferro-paramagnetic phase transition for the component of the magnetization in the direction of the easy axis. The molecular-field theory is used. The phase diagram and profiles of the order parameter are obtained. Different feasible investigations of the phase transition are compared. 相似文献
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为实现μs档条纹相机扫描非线性标定,建立了基于延时可调信号源和外触发激光器的条纹相机μs档扫描非线性标定系统,弥补了标准具法的不足。系统通过延时值的递增,得到条纹相机扫描速度在全扫程的变化。系统中时间关系抖动来源主要是测试设备延时抖动和条纹相机触发延时抖动。时间抖动测试与分析显示,条纹相机延时抖动±0.6ns,测试设备延时抖动±0.3ns,系统总时间抖动±0.7ns。系统时间抖动会造成最终时间轴信息的起伏。大量数值模拟分析表明,时间轴起伏对系统时间抖动的影响±2ns,在可以接受的范围内。因此,该系统能够胜任条纹相机μs扫程时间信息的测量标定。 相似文献
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YANG Xiao-Dong MAO Li-Jun LI Guo-Hong LI Jie MA Xiao-Ming YAN Tai-Lai YUAN You-Jin SONG Ming-Tao YANG Jian-Cheng LIU Yong ZHAO Tie-Cheng XIA Jia-Wen ZHANG Wei GAO Da-Qing ZHOU Zhong-Zu YAN Hong-Bin MAO Rui-Shi HE Yuan HAN Shao-Fei ZHENG Jian-Hua YANG Xiao-Tian ZHAO Hong-Wei XIAO Guo-Qing YIN Da-Yu LI Peng JIA Huan Parkhomchuk Vasily Reva Vladimir Skorobogatov Dmitry 《中国物理C(英文版)》2010,34(7)
The 400 MeV/u 12C6+ion beam was successfully cooled by the intensive electron beam near 1 A in CSRe.The momentum cooling time was estimated near 15 s.The cooling force was measured in the cases of different electron beam profiles,and the different angles between the ion beam and electron beam.The lifetime of the ion beam in CSRe was over 80 h.The dispersion in the cooling section was confirmed as positive close to zero.The beam sizes before cooling and after cooling were measured by the moving screen.The beam diameter after cooling was about 1 mm.The bunch length was measured with the help of the signals from the beam position monitor.The diffusion was studied in the absence of the electron beam. 相似文献
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旋涡的场特征与物质性──离散涡方法基础 总被引:6,自引:1,他引:5
旋涡的场特征与物质性──离散涡方法基础吴文权(华东工业大学,上海,200093)关键词旋涡动力学,旋涡场性,旋涡物质性众人关注的不稳定、非定常、分离流动无不与旋涡有关。因而对旋涡的研究吸引了人们的注意。尤其是近来非线性科学的发展,提供了新的思想、方法... 相似文献
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旋翼的流场呈现很强的非定常现象.目前,对旋翼定常流场的计算已经基本成熟,非定常流场的计算仍在探索之中。本文基于有限体积法的思想,利用较成熟的商用软件NUMECA/IGG生成计算所需的网格。对N-S方程进行离散,选用Baldwin-Lomax湍流模型,Dual-Time时间推进格式模拟了旋翼的非定常流场。计算的结果与文献给出的实验结果符合得较好。 相似文献
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The transverse vibrations of a plane system of rods is considered. The analysis of internal resonance in the system is a primary purpose of the paper. The internal resonance analyzed has an autoparametric nature. The couplings of the elements of the system through internal longitudinal forces, which are transverse forces at the ends of neighbouring rods, are taken into account. The amplitudes of the vibrations in the stationary states of internal resonance are investigated. Non-linear terms appear in the equations of motion. These terms are non-linear damping and non-linear inertia, and have a geometrical nature. The approximate method of calculation gives formulae for the vibration amplitudes of the rods. Plots of the amplitudes against frequency are presented. The stabilizing effect of masses placed at the articulated joints of the system is shown. The influences of the inertia and damping values on the character of the curves is considered. The results obtained are of a qualitative character. 相似文献
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不同季节的虎杖根茎中8种矿质元素的光谱测定 总被引:4,自引:2,他引:2
采用空气-乙炔火焰原子吸收法,测定虎杖根茎的K,Ca,Na,Mg,Fe,zn,Mn,Cu等8种矿质元素的含量。对测定条件进行了实验,选择了最佳电离抑制剂和酸性介质。实验以氯化铯为电离抑制剂,盐酸浓度控制在2%以内,用氯化锶消除磷对Ca的干扰,使吸光值稳定,用标准曲线法进行测定,获得了满意效果。该方法简单、快速、准确,加标回收率为90.5%~108.2%,相对偏差为0.3%~0.7%,适合于植物矿质元素的分析。实验结果表明:虎杖根茎中含有丰富的矿质元素,其中以K,Ca元素含量最高。这与虎杖的药用效果相符。同时,每种元素含量随季节变化而变化,与其生长发育密切相关。 相似文献