首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
Elastic proton-40Ca scattering at Tp = 200 MeV is calculated within the Glauber theory on the basis of the α-particle model. The results are compared with the experimental data and those calculated in the relativistic model.  相似文献   

2.
解文方 《中国物理 C》1997,21(5):465-469
采用不同的模型,揭示三粒子系统内部振动能和集体转动能的竞争对系统组态的几何结构和空间取向的影响.  相似文献   

3.
Abstract

In this article, light reflection spectrums for different one-dimensional multi-layer structures are obtained. Optical reflectivities for periodic, superperiodic, and quasiperiodic structures have been calculated using the transfer matrix method. PBGs of each structure have been obtained using the optical reflectivity pattern. From a comparison of reflectivity and standard dense wavelength division multiplexing grids, it is demonstrated that narrow and dense band filters can be built from generalized Fibonacci quasiperiodic structures. Reflectivity of these structures contains bands that meet the ITU-T dense wavelength division multiplexing standard. Reflectivity of other multi-layer structures has poor or less potential to be used in dense wavelength division multiplexing systems.  相似文献   

4.
利用外差干涉仪的光学系统准直方法   总被引:1,自引:1,他引:0  
张琢  孙东松  乔立杰  南京达 《光学学报》1997,17(12):1759-1763
描述了基于外差干涉仪原理的用于精密空间光学的准直方法,分析了该方法进行光学系统准直的系统误差;结果表明,只要较好地控制倾斜误差和照明光源的质量,系统误差就可以消除。实验结果说明,系统的测量误差接近探测元件的分辨率。  相似文献   

5.
First-principles methods based on the density functional theory (DFT) are used in order to calculate the structural and optical properties of α-SiO2 cluster with the non-bridging oxygen hole centers (NBOHC) and NBOHC-E' defects. We clarify the stable structure of the NBOHC-E' point defects for the first time using the functional B3LYP, which is also tested to investigate the influence of electronic properties. The calculation is carried out for cluster configurations extracted from supercell. The results of optical absorption peak for Si2O7H6 and Si5O16H12 with NBOHC-E' defects are found at 2.66 eV, which is higher than the often observed OA peak at 2.0 eV for the NBOHC defect in α-SiO2. The overall absorption spectra are in qualitative agreement with the experiment.  相似文献   

6.
Abstract Within the framework of the estended optical model, the gross resonant structures of the fusion escitation functions and the elastic scattering excitation functions for the 12C+12C and the 16O+20Ne systems are described well by using deep optical potentials. The origin of the gross resonant structures and the effect of the deep potential and the parity-dependent potential are discussed.  相似文献   

7.
8.
The K-nucleus differential elastic scattering cross section for 12C and 40 Ca at pκ = 800 Me V/c is calculated with three momentum-dependent optical potential models,which are density-dependent,relativistic mean field,and hybrid model,respectively.It is found that the forms of momentum-dependent optical potential models proposed by us are reasonable and gain success in the calculations and the momentum-dependent hybrid model is the best model for the K- nucleus elastic scattering.  相似文献   

9.
The experimental data of the neutron total cross section σt,nonelastic cross section σnon and elastic scattering angular distribution σel(θ) for ten target nuclei ranging from 12C to 238U with incident energies En=20—1000MeV were used to optimize the relativistic phenomenological optical potential (RPOP) through automatic search of the best parameters by computer.In addition,a relativistic microscopic optical potential (RMOP) based on Walecka model were also used to analyze the same data and compare with the RPOP.
Through comparison between these two kinds of relativistic optical potential hints in improving both the RMOP and RPOP is indicated.  相似文献   

10.
In this paper, quantum teleportatlon of one-to-many using (n +1)-particle entanglement is presented. If the sender (Alice) wants to transmit an unknown quantum state to a distant receiver (Bob), similar to the previous schemes, Alice performs Bell-state measurement on particles belonging to herself and informs the receiver the results through the classical channel. After that, it needs to perform the Hadamard operation on the other (n - 1) particles and measure them as well. With the aid of the measurement results, Bob can operate a corresponding unitary transformation on his particle to reconstruct the original state. Of course, the reconstruction may realize at either location of n, but it cannot realize at all locations at the same time.  相似文献   

11.
李菲  侯再红  吴毅 《光学学报》2012,32(9):906003-46
无线光通信(FSO)系统的性能受大气湍流影响会产生剧烈波动。根据系统和大气参数评估系统差错性能的研究具有现实意义。以大气湍流信道和光电探测模型为基础,使用拟合概率分布替换常用的对数正态分布,建立了FSO系统差错性能的数学仿真模型,改进了湍流条件下系统误码率计算公式,并且进行全天的验证实验。实验结果显示,光强概率分布对系统性能有显著的影响,原有公式在某些情况下的计算结果有较大偏差,而改进公式的计算结果具有更好的适应性和准确性。该改进公式可有效评估湍流条件下FSO系统性能,并为相关理论研究提供参考。  相似文献   

12.
混入逃逸函数的实数编码遗传算法优化光学系统   总被引:2,自引:0,他引:2  
王泽民  吕丽军 《光子学报》2014,43(6):622001
为了得到超多参量光学系统的最佳设计,将标准遗传算法的二进制编码改为实数编码以提高算法的鲁棒性和计算效率,并在评价函数中混入逃逸函数避免优化过程陷入局部极值.用改进后的遗传算法和CODE V对鱼眼镜头光学系统和折反射全景成像系统的设计案例进行光学参量优化,并应用Zemax对两种优化结果进行光线追迹成像模拟.计算结果表明,应用改进遗传算法比混入逃逸函数的遗传算法或CODE V软件优化所得到光学系统的成像质量有明显提高,在优化超多参量光学系统时具有较为理想的鲁棒性和计算效率.  相似文献   

13.
A multi-beam module using optical waveguides has been studied for a laser scanning optical system. Laser diodes with a wavelength of 780 nm are assembled on a silicon substrate. The beams emitted from the laser diodes are directly coupled into waveguides. This multi-beam module is assembled on a metal substrate with a photodiode. The photodiode controls the power of each laser diode on the silicon substrate. The multi-beam module is able to increase the output speed of high-density image printings, and the speed for high-speed color printings. We have developed the four-beam module with beam divergence angles of 11 degrees and spatial beam interval of 24 μm. Additional heat sink and optimizing tip-bonding between the laser diode and solder pad on the silicon substrate is useful to stabilize laser power against rising temperature.  相似文献   

14.
Series of exactly solvable non-trivial complex potentials (possessing real spectra) are generated by applying the Darboux transformation to the excited eigenstates of a non-Hermitian potential V(x). This method yields an infinite number of non-trivial partner potentials, defined over the whole real line, whose spectra are nearly exactly identical to the original potential.  相似文献   

15.
A new optical communication system exhibiting a double security level is presented. Information coding is based on combined modulation formats of two data streams over the same optical carrier. Incoherent and coherent optical encryption algorithms are presented and are theoretically analyzed. The optical encryption method is transparent to data bit rates. Furthermore, it requires "on-line" data decoding with no possibility of recording and further processing. The incoherent scheme is very practical and can be implemented in existing optical communications systems, using currently available technology. Computer experiments of the incoherent method indicate less than 25 dB of signal to noise ratio required for 10-9 bit error rate and ineligible information decoding time of more than 10 8 years.  相似文献   

16.
Gold and silver nanomaterials (NMs) such as nanoparticles (NPs) and nanoclusters (NCs) possessing interesting optical properties have become popular sensing materials. With strong surface plasmon resonance (SPR) absorption, extraordinary stability, ease in preparation, conjugation, and biocompatibility, Au NPs are employed to develop sensitive and selective sensing systems for a variety of analytes. However, small sizes of Au and Ag NCs with interesting photoluminescence (PL) properties are used in many PL‐based sensing systems for the detection of important analytes. In addition, many bimetallic AuM NMs possessing strong catalytic activity are used to develop highly sensitive fluorescent sensors. This review article is categorized in four sections based on the NMs used in the sensing systems, including Au NPs, bimetallic AuM NMs, Au NCs, and DNA–Ag NCs. In each section, synthetic strategies and optical properties of the NMs are provided briefly, followed by emphasis on their analytical applications in the detection of small molecules, metal ions, DNA, proteins, and cells. Current challenges and future prospects of these NMs‐based sensing systems will be addressed.  相似文献   

17.
利用原子力显微镜(AFM)、X射线衍射仪(XRD)研究了在氧化硅衬底上生长的α-四噻吩(α-4T)薄膜的表面形貌及分子取向。在低温下,获得了大尺寸、高有序的α-4T薄膜,为横向生长模式。衬底温度35 ℃以上转为纵向生长模式。晶体结构分析发现,α-4T薄膜属于单斜晶系,分子c-轴垂直基板排列。强的衍射峰和高有序的衍射峰意味着α-4T薄膜具有高的有序性和结晶性。电性能研究发现,提高衬底温度有利于提高薄膜的迁移率,衬底温度为35 ℃时器件迁移率为3.53×10-2 cm2·V-1·s-1。但衬底温度进一步增加,迁移率反而下降,与原子力分析结果一致。低温退火可以降低器件的亚阈值陡度,从13.27 V·dec-1降低到3.83 V·dec-1,使器件的界面缺陷降低,电性能提高。  相似文献   

18.
We consider weakly bound two-body systems. We study the behavior of the ground state mean square radius as the binding energy tends to zero in the case of complex potentials. We show that the asymptotic law, obtained with real potentials, is modified by the occurrence of a finite width in the case of finite-range potentials. The case of the PT-symmetric potentials is also discussed. We complete our study with few remarks concerning the same problem for three weakly bound particles.  相似文献   

19.
20.
Starting from the Walecka model about relativistic nucleon-meson field theory,the effect of interaction range in the relativistic microscopic optical potentials for nucleon-nucleus is included by folding the optical potentials in Local Density Approximity with nucleon-nucleon interaction potentials from the Walecka model.The present potentials are used to analyze the proton elastic scattering from nuclei.The agreement of the present calculation with experiment data is better than that of LDA.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号