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161.
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163.
The finite temperature properties of self-assembled dipole chains of polar molecules in strongly confined pancake traps are investigated. The single-chain vibrations at finite temperature, which become important for long chains in a strongly interacting regime, are found to lower the transition temperature and to shift the chain distribution by less than 10%. We also propose experimental parameters to observe such quantum phase transition. 相似文献
164.
Bunch lengthening phenomenon is resulted from one of the most severe single bunch instabilities in storage rings. We develop a new code to calculate the single bunch length and energy spread in storage rings using FORTRAN. In this code, wake field is calculated using an analytical formula, which is different from the previous ones. The bunch length and energy spread under different bunch currents are calculated for BEPCII by using this code, and the tracking results are in good agreement with those from other codes. The calculated energy spread clearly shows that the longitudinal microwave instability threshold is around 65 mA for BEPCII storage ring. 相似文献
165.
基于三代近贴式像增强器,设计了磁镜阵列装置的结构,从理论上计算了该装置的调制传递函数以及将其引入像增强器后整体的调制传递函数,以此来分析对成像质量的影响.通过对实际参量绘制的调制传递函数曲线分析,得出磁镜阵列装置在X、Y方向的极限分辨率分别为117lp/mm、121lp/mm,奈奎斯特频率处的调制传递函数值分别为0.55、0.59,同时磁镜阵列像增强器的极限分辨率也分别达到了87lp/mm、89lp/mm,相应的奈奎斯特频率处的调制传递函数值为0.49和0.52.结果表明X和Y方向的调制传递函数曲线之间差异较之磁镜阵列装置变小,这对保证成像质量起到了积极的作用.文章为进一步深入研究磁镜阵列像增强器提供了重要的理论依据. 相似文献
166.
由衍射理论模型出发,分析了子孔径布局对光学系统点扩散函数的影响,从而进行傅里叶变换计算出其对光学系统光学传递函数的影响;并由光学设计软件内嵌程序将子孔径布局实际地加入到设计的光学系统中,分析各种不同子孔径布局对光学系统像质的影响.通过由衍射理论出发的计算结果与设计软件内嵌程序的模拟仿真结果的对比,软件内嵌程序的模拟仿真结果得以验证.针对子孔径布局对具有相同相对孔径光学系统的影响进行了仿真计算,对与子孔径拼接原理样机具有相同相对孔径和中心遮拦比的反射式光学系统,针对相同孔径布局对其光学传递函数的影响进行了实际测试,通过仿真计算结果与测试结果的对比分析表明,孔径布局对具有相同相对孔径拼接光学系统的光学传递函数影响趋势一致的结论,从而为子孔径拼接原理样机研究的实用性及像质检测提供了理论依据. 相似文献
167.
Polyelectrolyte multilayer (PEM) films offer a method to functionalize substrates with specific properties that enable the films to be used for a variety of purposes. Desirable qualities of PEM films can include mechanical strengths, ease of preparations, flexibility, and their abilities to have their properties tailored to suit a particular process. We present a simple method to fabricate a class of PEM films that incorporate cubic silsesquioxane nanoparticles (CSSQ). Through a spin self-assembly (SSA) process, a hybrid multilayered film with two-components, namely, poly(styrene sulfonate) (PSS) and octaammonium cubic silsesquioxane (CSSQ) nanoparticle have been fabricated. The formation of this multilayer film is further verified by ellipsometry, contact angle studies, and atomic force microscopy (AFM). The water contact angle and ellipsometric measurements exhibit that the (PSS/OA-CSSQ) films are deposited onto the substrate. The surface topography of the deposited bilayers of PSS/OA-CSSQ film appears to be uniformly distributed with extremely small granules but the film uniformity of the granular surface is diminished and clusters of granules are observed at above 5 bilayers due to the aggregation of the OA-CSSQ nanoparticles. 相似文献
168.
Effects of Rapid Thermal Processing on Microstructure and Optical Properties of As-Deposited Ag2O Films by Direct-Current Reactive Magnetron Sputtering 下载免费PDF全文
(111) preferentially oriented Ag2O film deposited by direct current reactive magnetron sputtering is annealed by rapid thermal processing at different annealing temperatures for 5 min. The film microstructure and optical properties are then characterized by x-ray diffractometry, scanning electron microscopy, and spectrophotometry, respectively. The results indicate that no clear Ag diffraction peak is discernable in the Ag2O film annealed below 200°C. In comparison, the Ag2O film annealed at 200°C begins to exhibit characteristic Ag diffraction peaks, and in particular the Ag2O film annealed at 250°C can demonstrate enhanced Ag diffraction peaks. This implies that the threshold of the thermal decomposition reaction to produce Ag particles is approximately 200°C for the Ag2O film. In addition, an evolution of the film surface morphology from compact and pyramid-like to a rough and porous structure clearly occurred with increasing annealing temperature. The porous structure might be attributable to the escape of the oxygen produced during annealing, while the rough surface might originate from the reconstruction of the surface. The dispersion of interference peak intensity in the reflectance and transmission spectra could be attributed to the Ag particles produced. The lowered crystallinity and Ag particles produced induce a lattice defect, which results in an enhanced transmissivity in the violet region and a weakened transmissivity in the infrared region. 相似文献
169.
Theoretical Study of Interesting Fine-Structure Splittings Based on a Scenario for Precise Calculations 下载免费PDF全文
Based on the multi-configuration Dirac-Fock self-consistent field method, a scenario has been presented to calculate the fine-structure energy levels of C^2+ and Si^2+ excited states (31 D2 and 33D1,2,3). The Breit interactions and quantum electrodynamics corrections are added as perturbations. The present calculation results are found to be in excellent agreement with the experimental data. By means of the precise calculation procedure, we elucidate that four competitive mechanisms influence the interesting fine-structure splittings in C^2+ and Si^2+, such as spin-orbit interactions, relativistic corrections of exchange interactions, the Breit interactions and electron correlation effects. Furthermore, the mechanism of relativistic correction of exchange interactions has been studied clearly. We elucidate that the inner shell 2p1/2,3/2 orbitals are essential to relativistic corrections of exchange interactions which are crucial for the final anomalous fine-structure splittings. 相似文献
170.
Chong Li 《Physics letters. A》2010,374(29):2994-10714
The effect of different vacancies on the morphology of the O-terminated Cu2O(111) surface has been studied through the first-principles calculations. Our results show that Cu and O vacancies trigger large relaxations and formation of two different facets. Our emulated STM images are in consistent with the experimental STM patterns. A sizeable magnetic moment (∼1.0 μB) was found for surfaces with either Cu or O vacancies. The calculated formation energies of surface vacancies indicate that the deficient surfaces are more stable than the stoichiometric O-terminated (1×1) surface, which is also in line with our results obtained from ab initio atomistic thermodynamics studies. 相似文献