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1.
DyeLaser-pumpedCr:LiSrAIF_6Laser¥WUXing(Dept.ofPrecisionInstrumentEngineering,Tianjin300072,China)T.Okada,K.Kaeda(Dept.ofElec?..  相似文献   

2.
评介TheArtofExperimentalPhysics一书曹建庭(高等教育出版社)该书书名可译作《实验物理艺术》,它是DarylW.Preston和EricR.Dietz合著,由JohnwileyandSonsInc.于1991年出版.该书是D....  相似文献   

3.
MOCVD法在金属基体上制备YBCO超导带   总被引:2,自引:0,他引:2  
本报道了用MOCVD静态和动态沉积两种工艺制备YBCO超导带的实验结果。以Y(TMHD)3、Ba(TMHD)2和Cu(TMHD)2为挥发源,O2气为反应剂,高纯Ar气为载流气体,在静止和以10-15cm/h带速移动的金属银基体上,制出了有强烈c-轴取向的YBCO超导带。静态沉积样品的Jc达到1.04×10^4A/cm^2,动态沉积样品的Jc达到1.4×10^4A/cm^2(78K,0T)。对改…  相似文献   

4.
Phase-Mixture Algorithm Applied to Design of Pure Phase Elements   总被引:3,自引:0,他引:3  
Phase-MixtureAlgorithmAppliedtoDesignofPurePhaseElementsDENGXuegong ̄1;LIYongping(Y.P.LI) ̄(1,2)( ̄1PhysicsDepartment,University...  相似文献   

5.
BifurcationofDickeModelDrivenbyLaserFieldandScalingTheoryofCriticalExponentsFarfromEquilibriumOUFa(CCAST(WorldLaboratory)P.O....  相似文献   

6.
DesignofMetal-cladTi:LiNbO_3PolarizerHUH.Z.,CHENGG.(DepartmentofappliedPysics,TianjinUniversity,Tianjin300072,China)GENF;SONG...  相似文献   

7.
LaserDiodePumpedUnidirectionalRingLaserResonatorwithAOMQ┐switchJ.Chen1)A.Dehn2)H.J.Eichler2)A.Haase2)O.Mehl2)(1)NationalKeyL...  相似文献   

8.
析相光度法测定铜(Ⅱ)的研究   总被引:3,自引:0,他引:3  
本文研究了Cu-PEG-DDTC(铜试剂)(NH4)2SO4体系的析相光度法并应用于测定Cu。最宜酸度为3.6-9.0(NaAc-HAc,NH4Cl-NH3.H2O)缓冲溶液,其络合物的最大吸收位于450nm,表观摩尔吸光系数为9.05×10^3L.mol^-1.cm^-1,Cu浓度在0-30μg/L范围内服从比耳定律,铜与DDTC形成组成为1:2的稳定络合物。该方法用于铝合金中铜的测定,获得了满  相似文献   

9.
首次报道了单功能化氮氧杂大环化合物的合成和晶体结构,该化合物晶体属三方晶系,R3空间群,其晶胞参数为;a=3.5194(1),c=1.0397(1)nm,V=11.153(6),Z=18,Mr=552.8,Dc=1.482g/cm^3,最终偏差因子R=0.0491,R=0.0597。  相似文献   

10.
在Na-K混合蒸汽中,利用染料激光器,将基态Na原子双光子激发到5S态。用荧光法测量了过程Na(5S)+K(4S)→Na(3S)+K(8D,10S)的碰撞转移截面,K8D,10S对Na5S的荧光比中,含有K8D10S碰撞转移的影响。第2个实验可以消除这个影响,双光子激发K原子到8D(或10S)探测8D(10S)对10S(8D)的荧光比,Na(5S)→K(8D,10S)碰撞转移截面(10-15cm2)分别是10.5±4.2和9.5±3.8  相似文献   

11.
差分吸收激光雷达回波信号统计模型的研究   总被引:3,自引:0,他引:3  
差分吸收激光雷达回波信号统计模型是研究差分吸收激光雷达系统的基础,但是现有的统计模型中均没有考虑大气湍流导致的激光闪烁对回波信号的影响。针对已有统计模型的缺陷和应用需要,综合考虑了大气湍流导致的激光闪烁、目标反射斑纹、接收噪声以及发射功率波动对回波信号统计特性的影响,提出了一种改进的长程差分吸收激光雷达回波信号统计模型,分析了该模型的统计特性。仿真结果表明大气湍流导致的激光闪烁对回波信号统计特性的影响十分显著,同时也验证了该统计模型比已有统计模型更精确、更符合实际。  相似文献   

12.
A purely statistical characterization of measurements of observables (described by spectral measures in conventional formalism of quantum mechanics) is given in the framework of the general statistical (convex) approach. The relation to physical premises underlying the conventional notion of observable is discussed. Structural aspects of general statistical models such as central decomposition and characterization of classical models are considered. It is shown by explicit construction that an arbitrary statistical model admits a formal introduction of “hidden variables” preserving the structural properties of a single statistical model. The relation of this result to other theorems on hidden variables is discussed.  相似文献   

13.
A new interpretation of the statistical bootstrap model is proposed, on the basis of which the statistical bootstrap equation is modified. A deep relationship between the statistical bootstrap model and the Pomeranchuk model for multiple hadron production is established and as a result the significance of the volume V in the statistical bootstrap model is elucidated.  相似文献   

14.
In this paper, a modification of the diffusion model for room acoustics is proposed to account for sound transmission between two rooms, a source room and an adjacent room, which are coupled through a partition wall. A system of two diffusion equations, one for each room, together with a set of two boundary conditions, one for the partition wall and one for the other walls of a room, is obtained and numerically solved. The modified diffusion model is validated by numerical comparisons with the statistical theory for several coupled-room configurations by varying the coupling area surface, the absorption coefficient of each room, and the volume of the adjacent room. An experimental comparison is also carried out for two coupled classrooms. The modified diffusion model results agree very well with both the statistical theory and the experimental data. The diffusion model can then be used as an alternative to the statistical theory, especially when the statistical theory is not applicable, that is, when the reverberant sound field is not diffuse. Moreover, the diffusion model allows the prediction of the spatial distribution of sound energy within each coupled room, while the statistical theory gives only one sound level for each room.  相似文献   

15.
A family of probability distributions (i.e. a statistical model) is said to be sufficient for another, if there exists a transition matrix transforming the probability distributions in the former to the probability distributions in the latter. The Blackwell-Sherman-Stein (BSS) Theorem provides necessary and sufficient conditions for one statistical model to be sufficient for another, by comparing their information values in statistical decision problems. In this paper we extend the BSS Theorem to quantum statistical decision theory, where statistical models are replaced by families of density matrices defined on finite-dimensional Hilbert spaces, and transition matrices are replaced by completely positive, trace-preserving maps (i.e. coarse-grainings). The framework we propose is suitable for unifying results that previously were independent, like the BSS theorem for classical statistical models and its analogue for pairs of bipartite quantum states, recently proved by Shmaya. An important role in this paper is played by statistical morphisms, namely, affine maps whose definition generalizes that of coarse-grainings given by Petz and induces a corresponding criterion for statistical sufficiency that is weaker, and hence easier to be characterized, than Petz’s.  相似文献   

16.
针对光电武器对机动目标跟踪精度较差的问题,在"当前"统计模型的基础上,形成了机动目标"当前"统计模型下强跟踪滤波算法。该算法通过引入强跟踪滤波器的渐消因子,实时调节滤波器增益,增强了系统对突发机动目标的跟踪能力,同时保留了"当前"统计模型跟踪算法对一般机动目标跟踪精度高的特点。仿真结果表明,该算法对机动目标具有较好的跟踪精度和适中的计算复杂度,是一种较好的光电跟踪算法。  相似文献   

17.
As is well-known, there are two contrasting and fundamental models for simulating actual random processes with time series: a multiplication model and an addition model. In this letter, two explicit expressions of the probability density function for a non-stationary non-negative random process (a statistical Laguerre expansion type and a statistical Hermite expansion type) are derived from the above two fundamental viewpoints of modeling a time series, in relation to the statistical method described in a previous paper by the authors, in which the analysis was based on the use of a Hankel transform type characteristic function. The unified theory introduced in this previous paper can be obtained by a very simplified calculation as compared with that of the previous study, by the natural introduction of a random time series multiplication model.  相似文献   

18.
The diffusion of quantum particles is investigated within a generalized Haken-Strobl-Reinecker model. The stochastic part in this model is assumed to be the result of a nonthermal vibration in the system. Transport is modified since the statistical properties of nonthermal vibrations differ significantly from those of thermal ones. To determine these statistical properties an equation for the characteristic functional is solved. Applying the result to a special model one obtains that the mean square displacement of quantum particle increases as the 3/2th power of time, instead of the usual first power of time.  相似文献   

19.
A path-integral method is extended and developed to investigate the statistical physics of one-dimensional random systems. Evaluation of the one-particle partition function and density matrix is simplified to finding a solution for a second-order ordinary differential equation. This makes it possible to obtain analytic solutions or conduct accurate numerical calculations for the random systems. With this approach, an analytical solution for the Gaussian model is obtained and the statistical physics of the Frisch–Lloyd model is studied.  相似文献   

20.
The collision between two heavy ions at high energies is discussed within the framework of a statistical model which is developed step by step so that it can be followed by a reader unfamiliar with this approach. As we hope to show, the statistical model forms a comprehensive framework for investigating various aspects of such collisions. When statistical thermodynamics is coupled with a one and two fireball model or a firestreak model, single particle and multiparticle inclusive cross sections can be evaluated. Specifically, single particle proton, deuteron, triton and pion cross sections are calculated and compared with experiment. Two particle correlations are discussed using the microcanonical ensemble. Multiplicity distributions are evaluated using the canonical ensemble and composite particle formation is simply obtained from the grand canonical ensemble. The power law behaviour of composite particle cross sections is studied. The thermodynamic model is justified by calculating various reaction rates. Many comparisons with experimental data are made.  相似文献   

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