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1.
DIELECTRONICRECOMBINATIONRATECOEFFICIENTSFORNEONLIKEIONSDIELECTRONICRECOMBINATIONRATECOEFFICIENTSFORNEONLIKEIONS¥ZhaoLibo;LiS...  相似文献   

2.
罗亦孝 《物理》1998,27(6):332-337
综述了近年来我国在远离稳定线原子核实验研究中取得的重要进展.这些实验研究工作主要是在中国科学院近代物理研究所(IMP)、中国原子能科学研究院(CIAE)和中国科学院上海原子核研究所(SINR)进行的.文章还简要介绍了IMP和CIAE现有加速器上研制的放射性束流线及进一步的发展计划.  相似文献   

3.
Xe偶-偶同位素低激发态性质的IBM2描述   总被引:2,自引:0,他引:2  
通过考虑同类核子相干对Sρ、Dρ间的四极相互作用,在IBMZ中对Xe偶一偶同位素116Xe—132Xe的低激发态能谱和E2跃过几率进行了理论分析.计算结果有效地改善了IBM中这些核的准γ带能谱的Staasering现象,较精确地描述了实验观察到的低激发态的性质.  相似文献   

4.
几种多环芳烃化合物EL材料性质的量子化学研究   总被引:1,自引:1,他引:0  
廖显威  任译 《发光学报》1998,19(2):164-168
采用从头算方法(RHF/4-31G)和半经验方法AM、PM3对几种多环芳烃化合物电致发光(EL)材料的性质进行了理论研究。并对三联苯作了构象分析,找出能量最低的构象,即两侧苯环分别城外各扭转41.6°±0.5°,对各优化后的构型作振杂质镁未出现虚频率,在此基础上,采用RHF/CIS方法计算其电子光谱,并给出了化合物E2,E3电子光谱的波长λ与CIS的组态数之间的民有计算结果与实验值基本吻合。  相似文献   

5.
计算机自动配色预测算法研究   总被引:5,自引:0,他引:5  
徐海松  叶关荣 《光学学报》1996,16(11):657-1661
基于配色基础理论Kubelka-Munk定律的常数形式,建立了计算机自动配色的三刺激值匹配算法,通过纺织印染自动配色预测实验表明该算法可获得色差ΔE小于0.10CIELAB的满意配方。  相似文献   

6.
应用有效折射率/有限元法(EI-FEM),考虑到LiNbO3晶体和Ti扩散的各向异性,折射率增量与寻常光、非寻常光及波长色散的关系,设计了1.55μm光波长下工作的z切y传播Ti:LiNbO3单模条波导的制备参数,计算和分析了其单模特性、模式场分布及其变化规律.扩展了EI-FEM,将其用于求解耦合波导系统,确定了方向耦合器的耦合长度及其波长色散特性.  相似文献   

7.
基于扩散速度方法粘性流场的离散涡数值模拟   总被引:1,自引:0,他引:1  
基于扩散速度方法粘性流场的离散涡数值模拟吴文权,李春,卜千里(上海机械学院上海200093)关键词:扩散速度模型,粘性流场,离散涡方法。NUMERICALSIMULATIONOFVISCOUSFLOWFIELDSUSINGDIFFUSIONVELOC...  相似文献   

8.
离子与原子碰撞中多电子转移的经典描述   总被引:1,自引:1,他引:0  
讨论了几各地独立电子模型(IEM)描述离子与原子碰撞中电子转移的经典模型,即Bohr-Lindhardt模型,过垒模型OBM和分子库仑垒模型MCBM。较详细阐述了描述碰撞过程的经典物理图象,着重讨论了MCBM描述的多电子转移过程,分析了几各模型的特点和适用性,最后在考虑了入射离子量子数亏损和出射过程电子束缚能移动的修正后,给出了修正后的MCBM的计算结果,并与Niehaus的计算结果玫实验结果进行  相似文献   

9.
液排渣粉煤旋风燃烧器内流场的数值模拟   总被引:1,自引:0,他引:1  
本文采用数值计算的方法对液排渣粉煤旋风燃烧器内的流场进行了模拟。在研究中运用分散颗粒群模型建立了燃烧器内三维等温流场的数学模型。流场的计算采用了SIMPLE及其系列方法,其中湍流计算采用k-ε模型。模型计算结果与实验结果基本吻合,证明了模型的可靠性。  相似文献   

10.
SHOCKCOMPRESSIONBEHAVIOROFBROMOFORMPengShangqianga,b,cJingFuqiana,bHuJinbiaoa,bGouQingquanba.LabforShockWaveandDetonationPhy...  相似文献   

11.
The performance of GMPLS network depends upon the various parameters such as number of channels, number of sources, traffic intensity etc. In this paper we have proposed a call blocking model for mode of operation to determine the type of applications suitable for GMPLS networks. Further we have suggested a switch model for GMPLS network and developed a mathematical model for GMPLS network for call blocking probability and call holding probability. In proposed model blocking probability of the network is reduced and then the call blocking performance of the model is compared with the call holding performance.  相似文献   

12.
In this work we propose a variational multiscale finite element approximation of thermally coupled low speed flows. The physical model is described by the low Mach number equations, which are obtained as a limit of the compressible Navier–Stokes equations in the small Mach number regime. In contrast to the commonly used Boussinesq approximation, this model permits to take volumetric deformation into account. Although the former is more general than the latter, both systems have similar mathematical structure and their numerical approximation can suffer from the same type of instabilities.  相似文献   

13.
Recently Brenner [Physica A 349, 60 (2005)] proposed a modified Navier-Stokes set of equations. Based on some theoretical arguments and some limited experiments, the model is expected to be able to describe flows with a finite Knudsen number. In this work, we apply this model to the plane Poiseuille flow driven by a force, and compare the results with the Direct Simulation Monte Carlo (DSMC) measurements. It is found that Brenner's model is inadequate for flows with a finite Knudsen number.  相似文献   

14.
黄伟超  刘丁  焦尚彬  张妮 《物理学报》2015,64(20):208102-208102
为了改善复杂对流形态下的晶体生长品质, 提出了一种改进的格子Boltzmann方法研究非稳态熔体流动和传热的耦合性质. 该方法基于不可压缩轴对称D2Q9模型, 构建了包含旋转惯性力和热浮力等外力项的演化关系, 实现了对轴对称旋转流体的速度、温度和旋转角速度的计算与分析. 结果表明, 非稳态熔体中的流、热耦合性质与格拉斯霍夫数和雷诺数的相互作用有关; 通过调节高雷诺数, 可有效抑制熔体中的自然对流, 改善温度分布, 有助于提高单晶的品质. 数值计算结果与实际硅单晶生长试验均证明了所提方法的正确性及有效性.  相似文献   

15.
In this Letter we present a new inflationary model composed of multiple scalar fields where each of them has its own DBI action. We show that the dependence of the e-folding number and of the curvature perturbation on the number of fields changes compared with the normal N-flation model. Our model is also quite different from the usual DBI N-flation which is still based on one DBI action but involves many moduli components. Some specific examples of our model have been analyzed.  相似文献   

16.
Amit Wason  R.S. Kaler 《Optik》2011,122(18):1638-1641
In this paper we have proposed a mathematical model to reduce the blocking probability of the WDM optical network. The mathematical model proposed has a closed-form expression and does not require simulated statistics, it has low implementation complexity and the computation is quite efficient. This model suggests us to choose the best path and appropriate number of free wavelengths in the network. We can go for the compromise between the path length and number of free wavelength. The model is also used to evaluate the blocking performance of NSFNet topology and hence used to improve its performance.  相似文献   

17.
The aim of this study was to present a deterministic model for approximating the vibrations and the acoustic pressure radiated when a thin elastic plate is immersed in a low Mach number flow of fluid. As a prelude to this study, a classical random model based on a wavevector integration technique was used. In the case of a low Mach number turbulent flow, the numerical study showed that the subconvective region of the turbulent excitation power spectrum contributes significantly to the response of the panel. A deterministic approximate model was developed, based on this behaviour of the system.  相似文献   

18.
幂律指数在1与3之间的一类无标度网络   总被引:2,自引:0,他引:2       下载免费PDF全文
郭进利  汪丽娜 《物理学报》2007,56(10):5635-5639
借助排队系统中顾客批量到达的概念,提出节点批量到达的Poisson网络模型.节点按照到达率为λ的Poisson过程批量到达系统.模型1,批量按照到达批次的幂律非线性增长,其幂律指数为θ(0≤θ<+∞).BA模型是在θ=0时的特例.利用Poisson过程理论和连续化方法进行分析,发现这个网络稳态平均度分布是幂律分布,而且幂律指数在1和3之间.模型2,批量按照节点到达批次的对数非线性增长,得出当批量增长较缓慢时,稳态度分布幂律指数为3.因此,节点批量到达的Poisson网络模型不仅是BA模型的推广,也为许多幂律指数在1和2之间的现实网络提供了理论依据.  相似文献   

19.
Towards a model for discrimination of broadband signals   总被引:2,自引:0,他引:2  
The conventional model for broadband discrimination assumes that resolution is limited by peripheral internal noise that is statistically independent across channels. In this paper, we extend this model in a number of directions. In particular, we compute, compare, and discuss the effects of interchannel correlation and central noise on the sensitivity index d', for discrimination of overall level and discrimination of spectral shape.  相似文献   

20.
混响室测试技术的精确性取决于混响室能够产生大量的独立测试样本。通过理论分析得到混响室的体积、搅拌器的尺寸以及腔体的工作频率与独立样本数的关系,推导出独立样本数的近似模型,并将实验数据与模型计算结果进行比较,对模型进行了改进和验证。结果表明:独立样本数与混响室的体积、品质因数、搅拌器的尺寸正相关,在一定范围内与搅拌器的电学尺寸负相关。该模型可以用于计算具有不同配置的不同混响室的独立样本数,具有良好的准确性和一般性。  相似文献   

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