Simultaneous attainment of high electron and ion temperatures in discharges with internal transport barriers in ASDEX upgrade

Internal transport barriers have been demonstrated to exist also under conditions with T(e) approximately T(i) approximately 10 keV and predominant electron heating of the tokamak core region. Central electron cyclotron heating was added to neutral beam injection-heated ASDEX Upgrade discharges with a preexisting internal transport barrier, established through programmed current ramping leading to shear reversal. Compared to a reference internal transport barrier discharge without electron cyclotron resonance heating, the electron heat conductivity in the barrier region was found not to increase, in spite of a fivefold increase in electron heat flux, and also angular momentum and ion energy transport did not deteriorate.     

Electronic localization at mesoscopic length scales: different definitions of localization and contact effects in a heuristic DNA model

In this work we investigate the electronic transport along model disordered DNA molecules using an effective tight-binding approach, addressing the localization properties. Different tools to investigate the degree of localization are examined as a function of system length, energy dependence and DNA to electrode coupling: localization length, participation number and sensitivity to boundary conditions. Combining the results obtained from these different tools, a thermodynamic limit for the model DNA molecule, within the mesoscopic length scale, can be established. Furthermore, three aspects are investigated: (i) the influence of strongly localized resonances on the localization length is discussed as an important mechanism defining the degree of localization for sizes below the thermodynamic limit; (ii) the dependence on the Hamiltonian parameters on a possible diffusive regime for short systems; and, finally, (iii) possible length dependent origins for the large discrepancies among experimental results for the electronic transport in DNA samples.     

Pole model for nonlepton and radiative hyperon decay

Nonlepton and weak radiative decays of hyperons are analyzed on the basis of the pole model. In contrast with other analyses, the contributions from both baryon and meson poles are taken into account. Experimental information on these decays is used to find the parameters of the effective weak two-baryon interaction.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 8, pp. 17–22, August, 1969.The author thanks V. A. Filimonov and G. M. Radutskii for stimulating discission of this study.     

共光路移相单频激光干涉测长系统

单频激光干涉系统采用偏振光移相方法,用来解决常规单频激光干涉仪中的光强"零漂"问题。共光路设计提高了干涉系统的测量稳定性和重复性。采用光程差放大技术提高了干涉系统的分辨力。在构造了一套实验布局的基础上,分析了影响系统测长精度的主要因素,并对干涉系统的测量误差分量做了定量的分析,完成了系统的精度测试。     

Holographic interferometry and speckle photography for strain measurement: A comparison

Holographic interferometry and speckle photography are essentially described by the same equations. The sensitivity and the range of displacements at which the methods are applicable are different however. The accuracy of strain measurement, using high resolution opto-electronic evaluation in both cases, is estimated and compared.     

Endoscopy system for length measurement by manual pointing with an electromagnetic tracking sensor

We propose a practical and simple measurement function of three dimensional (3D) length for endoscopy based on triangulation using manually pointed correspondences. This system is a novel combination of conventional methods. 3D length information is useful for many medical purposes and the burden of manual procedures can be reduced by focusing on length. We employed a novel combination for length measurement, that is, a monocular endoscope with an electromagnetic tracking sensor. The proposed method can measure the length without any equipment for light projection and changing the current procedure of endoscopy. Our method is made more robust and reliable than the automatic correspondence techniques through the best use of the expertise of endoscopists. We developed a prototype system and evaluated its accuracy. From experimental results, we showed that the proposed method can measure the 3D length of static objects accurately as long as the measurement geometry is suitable.     

A strategy for the development and standardisation of measurement methods for high power/cavitating ultrasonic fields: review of high power field measurement techniques

This review was compiled as part of a project to formulate a UK strategy for the development and standardisation of measurement methods for high power/cavitating ultrasonic fields. It reviews the scientific literature relating to various methods of measuring high power fields which have been developed for application in health care, sonochemistry and industrial ultrasonics, and compares these methods in terms of attributes such as spatial resolution, bandwidth and sensitivity.     

Muon decay: measurement of the transverse polarization of the decay positrons and its implications for the fermi coupling constant and time reversal invariance

The two transverse polarization components P(T1) and P(T2) of the e(+) from the decay of polarized mu(+) have been measured as a function of the e(+) energy. Their energy averaged values are P(T1)=(6.3+/-7.7+/-3.4) x 10(-3) and P(T2)=(-3.7+/-7.7+/-3.4) x 10(-3). From the energy dependence of P(T1) and P(T2) the decay parameters eta,eta(') and alpha(')/A,beta(')/A are derived, respectively. Assuming only one additional coupling besides the dominant V-A interaction one gets improved limits on eta, beta(')/A, and the scalar coupling constant g(S)(RR): eta=(-2.1+/-7.0+/-1.0) x 10(-3), beta(')/A=(-1.3+/-3.5+/-0.6) x 10(-3), Re{g(S)(RR)}=(-4.2+/-14.0+/-2.0) x 10(-3), and Im{g(S)(RR)}=(5.2+/-14.0+/-2.4) x 10(-3).     

薄凸透镜焦距测量方法的改进

本文分析了薄凸透镜焦距测量中存在的问题,并利用消除视差的方式来测量薄透镜焦距,第一种用消视差自准直法,用眼睛来代替目镜系统,将对像清晰程度的调节变为对横向的物与像视差的调节,可以大大的减少由焦深带来的误差.第二种用消视差共轭法,利用物与像的对称性,来测量焦距,同时巧妙的利用消除视差的方式.测量结果表明,利用消视差的方式得到的测量结果更精确,可达到0.4%.     

Random flight theory and the measurement of fibre length with special reference to the length of DNA

A sort of the random flight theory is applied to the measurement of the fibre length with special reference to the length of a bipolymer DNA from its image contour in an electron micrograph.     

Asymptotic formulas for calculating the decay length of linearly polarized groups in optical fibers with step-index profile

We obtain asymptotic expressions for the eigenvalue difference of the waveguide modes of an optical fiber with step-index profile. The estimation of accuracy of the formulas is presented. Relationship between the indices of the modes that form linearly polarized groups and the roots of the characteristic equation and the principal mode number is considered. Estimates for the difference between the eigenvalues and the decay length of linearly polarized groups in a perfect dielectric fiber are obtained. The results of experimental studies of the integral degree of linear polarization of the output radiation are shown for different input angles and their comparison with the theory is carried out. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 50, No. 5, pp. 426–440, May 2007.     

A geminate recombination model for photoluminescence decay in plasma-deposited amorphous Si:H

We develop a model of geminate electron-hole recombination, including tunnelling and diffusion, to account for photoluminescence decay in amorphous semiconductors. The model correctly predicts the shape of the decay, the luminescence quantum efficiency, and the microscopic electron mobility.     

KARMEN: Neutrino oscillation limits and new results with the upgrade

The neutrino experiment KARMEN is situated at the beam stop neutrino source ISIS which provides ν_μ's, ν_e's and from the π⁺−μ⁺-decay at rest. The oscillation channels ν_{μ → νe} and are investigated with a 56 t liquid scintillation calorimeter. No evidence for oscillations could be found with KARMEN, resulting in 90% CL exclusion limits of sin²(2Θ) < 8.5 · 10⁻³ ( ) and sin²(2Θ) < 4.0 · 10⁻² (ν_μ → ν_e) for Δm² > 100 eV². In 1996, the experiment has been upgraded by an additional veto counting system with a total coverage of 300 m². The new system allows the identification of cosmic muons in the vicinity of the detector. Vetoing these muons suppresses energetic neutrons from deep inelastic scattering of muons as well as from μ-capture by a factor of 40. Up to 1996, these neutrons represented the main background for oscillation search. The experimental sensitivity for will be significantly enhanced towards sin²(2Θ) 1.0 · 10⁻³ after a further measuring period of 2–3 years.     

激光散斑的亚像素位移法计算及比较

根据激光散斑相关测量中采用的插值法、梯度算法和牛顿一拉夫森迭代法3种亚像素位移算法的特点,逐一在亚像素尺度计算出磁流体干燥过程中的同一激光散斑图的偏均值和标准差变化曲线。基于得到的偏差均值和标准差讨论了3种算法处理激光散斑图的特点,比较了3种算法处理散斑图的计算精度、稳定性和计算用时。结果显示,在小变形的亚像素位移测量时,梯度算法的精度较高,且较为稳定,计算效率也较牛顿一拉夫森算法快约9倍。因此,在进行小变形亚像素位移测量时,采用梯度算法计算激光散斑是有效的。     

Hard-hexagon model: Anisotropy of correlation length and interfacial tension

The directional dependence of the correlation length of the hard-hexagon model is calculated by a new method which introduces the shift operator into the usual transfer matrix method. This method is also applied to the calculation of the interfacial tension of the hard-hexagon model, which is anisotropic. In addition, the equilibrium droplet shape of one phase embedded inside another is obtained from the analysis of the interfacial tension by the use of Wulff's construction.