T1系1223相超导体的不可逆线

研究了（Ｔｌ０．５Ｐｂ０．５）（Ｓｒ０．８Ｂａ０．２）２Ｃａ２Ｃｕ３Ｏｙ超导体的不可逆场Ｈ（Ｔ），并与Ｙ系Ｂｉ系和Ｔｌ１２１２相超导体作了比较。实验表明，在７７Ｋ下Ｔｌ１２２３相的不可逆场高达５Ｔ。证明了该材料在高温下的磁通钉扎比Ｂｉ系超导体和Ｔｌ１２１２相导体强得多，并对此作了讨论，由磁滞回线估计的磁化电密度Ｊｃ在７７Ｋ和２Ｔ磁场下大于１４＾４／ｃｍ＾２。     

X-Ray Radiation Characteristics of Nested-Wire Array Implosion in Sino-Russian Joint Z-pinch Experiments on Angara-5-1

We report and discuss the results of x-ray radiation measurements in the Sino-Russian joint Z-Pinch experiments on Angara-5-1 facility with a load current of 2.5-3.6MA. The measurements were conducted by using an x-ray power meter (XRPM) and a time-resolved one-dimensional x-ray imaging system developed in China Academy of Engineering Physics. The experimental results indicate that an x-ray power-platform prior to a main peak and a less intensive sub-peak after the main peak in the waveform exist for the nested-wire array implosions, and the radiation process is relatively faster than that in the case of the single array. Laser shadowgraph of the imploding plasma suggests that the prior power-platform is a result of the collision of the inner-outer plasma layers. The faster radiation process of nested array implosion can be explained by analysing the corresponding result of the time-resolved one-dimensional imaging system, which demonstrates a better axial imploding uniformity and synchronization. In comparison with x-ray diode, the XRPM yields a higher height of x-ray power-platform due to its fiat energy response. The sub-peak after the main peak is proposed to be a result of the later-time additional implosion of plasma.     

Dromion and Multi—soliton Structures of the （2＋1）—Dimensional Higher—Order Broer—Kaup System

Using the standard truncated Painleve analysis and the Backlund transformation,we can obtain many significant exact soliton solutions of the (2 1)-dimensional higher-order Broer-Kaup(HBK) system.A special type of soliton solution is described by the variable coefficient heat-conduction-liker equation.The inclusion of three arbitrary functions in the general expressions of the solitons makes the solitons of the (2 1)-dimensional HBK system possess abundant structures such as solitoff solutions,multi-dromion solutions,ring solitons and so on.     

Effects of Magnetic Coupling on Profile of Emission Lines and Images of an Accretion Disc Around a Black Hole

The profiles of emission lines and images of an accretion disc around a black hole (13tt) are simulated by considering the effects of the magnetic coupling (MC) of a central BH with the disc. The MC effects are discussed for both slow- and fast-spinning BHs, and the following results are obtained. Firstly, the width of the emission lines and the brightness of the disc are reduced and augmented for slow- and fast-spinning BHs, respectively. Secondly,the image of the disc becomes dimmer and brighter near the inner edge of the disc for slow- and fast-spinning BHs, respectively. It turns out that all these results arise from the MC effects on the position of the dominant emission region of the accretion disc.     

Binding Energies of Excitons in Square Quantum-Well Wires in the Presence of a Magnetic Field

The binding energies of the ground state of excitons in the GaAs/Ga1-xAlxAs square quantum-well wire in the presence of a magnetic field are investigated by using the variational method. It is assumed that the magnetic field is applied parallel to the axis of the wire. The calculations of the binding energy as a fimction of the wire size have been performed for infinite and finite confinement potentials. The contribution of the magnetic field makes the binding energy larger obviously, particularly for the wide wire, and the magnetic field is much more pronounced for the binding energy in a square quantum wire than that in a cylindrical quantum wire. The mismatch of effective masses between the well and the barrier is also considered in the calculation.     

Surfactant Effects of Au on Polar ZnO Surfaces

The electronic properties of one monolayer of Au atoms on polar ZnO surfaces are examined by first-principles slab calculations. It is found that an Au ad-layer on top of the surface is energetically more favourable than other gold diffused cases, and Au capping layer on the ZnO polar surfaces may modify the growing properties of ZnO nanostructures by enhancing the binding energy.     

Theoretical Studies of O(1D)+HD (v=0, j=0, 1, 2, 3)→OD(H)+H(D) Reaction

利用准经典轨线计算方法在DK势能面上对O+HD进行了计算,获得了产物的反应截面和分支比OD/OH. 计算结果表明,当碰撞能由4.6 kJ/mol增加到46.0 kJ/mol时,产物的反应截面随着碰撞能的增加明显减小;产物的平均分支比随着转动量子数的增加逐渐减小.     

Measurement of Gamma-Rays from 11ΛB and 12ΛC

From the ^12 C（π^＋,K^＋）^12 AC reaction the γ -rays of 261.6±0.24 ke V（7/2^＋ →5/2^＋）and 1481.7±0.7 ke V（1/2^＋ →5/2^＋） of ^11 A B,and 2667.3±2.8 keV（1^- 2 → 2^- 1）of ^12 A C hypernuclei have been identified using a large germanium detector array Hyperball2 at K6 beam line of KEK. The observed energies of the transitions 1481.7keV and 261.6 keV are significantly different from the values predicted by the shell model using the △ and SN parameters determined from the ^7 △ Li data.     

Growth of Silicon Nanowires by Heating Si substrate

Amorphous silicon nanowires were prepared by heating an Si substrate at high temperatures using an Ni (or Au) catalyst.The nanowires have a diameter of 10-40nm and a length of up to several tens of micrometres.Unlike the well-known vapour-liquid-solid mechanism,a solid-liquid-solid mechanism appeared to control the nanowire growth.The heating process had a strong influence on the growth of silicon nanowires.It was found that ambient gas was necessary to grow nanowires.This method can be used to prepare other kinds of nanowires.     

Central distance of interferential mode patterns of elliptical core two-mode fiber

By means of the weakly guiding approximation, the mode spot sizes Wx and Wy of the fundamental mode along the semimajor （x-direction） and semiminor （y-direction） axes of the fiber core in elliptical core two- mode fiber are discussed. The variation of their ratio value Wx/W9 with the operation wavelength A and the length ratio a/b between the semimajor axis and the semiminor axis of the fiber core is analyzed. Based on this analysis, the distribution figures of two-lobe interferential mode patterns are evaluated and simulated quantitatively for different phase difference changes between LP01 and LP~~n modes. The two-lobe interferential mode patterns have the same profile and distribute symmetrically when the phase difference equals ~r/2. Their central distance S becomes larger when W~：/W~ augments gradually. F~rthermore, the equation about the central distance S of the two-lobe interferential mode patterns is given when the operation wavelength varies between 0.65 and 1.31 #m, which is important to applications shuch as sensors and coupling devices between different fibers.     

Effects of the Spectral Line Broadened Model on the Performance of a Floing Chemical Oxygen—Iodine Laser

A new gain saturation model of chemical oxygen-iodine lasers(COILs)is deduced from from the conservation equations of the population number of upper and lower lasing levels,The present model is compared with both the Voigt profile function model and its low-pressure limit model.The differences between the Voigt profile function model or its low-pressure limit model and the model presented here are pointed out,such as the length of power extraction,the optimal range of the thershold gain.These differences are useful for the optimization of COIL adjustable parameters.     

Binding Energy of Biexcitons in GaAs Quantum-Well Wires

The binding energy ofa biexciton in GaAs quantum-well wires is calculated variationally by use of a two-parameter trial wavefunction and a one-dimensional equivalent potential model. There is no artificial parameter added in our calculation. Our results agree fairly well with the previous results. It is found that the binding energies are closely correlative to the size of wire. The binding energy of biexcitons is smaller than that of neutral bound excitons in GaAs quantum-well wires when the dopant is located at the centre of the wires.     

h-Deformation of GL(1∣1)

An h-deformation of a (graded) Hopf algebra of functions on supergroup GL(11) is introduced via a contraction of GL _q (11). The deformation parameter h is odd (Grassmann). A related differential calculus on h-superplane is presented.     

The physics of 2 ≠ 1 + 1

One of the most surprising consequences of quantum mechanics is the entanglement of two or more distant particles. In an entangled EPR two-particle system, the value of the momentum (position) for neither single subsystem is determined. However, if one of the subsystems is measured to have a certain momentum (position), the other subsystem is determined to have a unique corresponding value, despite the distance between them. This peculiar behavior of an entangled quantum system has surprisingly been observed experimentally in two-photon temporal and spatial correlation measurements, such as “ghost” interference and “ghost” imaging. This article addresses the fundamental concerns behind these experimental observations and to explore the nonclassical nature of two-photon superposition by emphasizing the physics of 2 ≠ 1 + 1.     

A Reanalysis of theA1Π–X1Σ+Transition of AlBr

TheA¹Π–X¹Σ⁺transition of aluminum monobromide (AlBr) near 2800 Å was recorded using a Bruker IFS 120 HR Fourier transform spectrometer at nominal resolutions of 4 and 0.03 cm⁻¹. All bands showP,Q, andRbranches and all are degraded to longer wavelengths. The 0–0 band is the most intense and the Δv= 0 sequence dominates the observed spectrum. Each band appears doubled due to the natural isotopic abundances of⁷⁹Br (50.69%) and⁸¹Br (49.31%). Band origin shifts due to isotopic substitution of bromine were examined to confirm the assignments of isotopic species. The rotational structure of the 0–1, 1–2, 0–0, 1–1, and 2–2 bands was assigned and fitted. These data were merged with previously reported photographic data for the 1–0, 2–1, 3–2, 2–0, and 3–1 bands and also infrared and microwave measurements to provide an improved set of constants for both electronic states. The rotational constants for each vibrational level in theX¹Σ⁺state vary smoothly with increasing vibrational quantum number and thus an expansion of the constants in terms of equilibrium values is recommended. An expansion of theA¹Π rotational constants in terms of equilibrium values is not recommended as the distortion constants do not change smoothly with increasing vibrational quantum number. Therefore, the rotational constants for theA¹Π state were determined for each individual vibrational level. This approach leads to vastly improved vibrational constants for theA¹Π state by reducing correlations between rotational and vibrational constants. This problem is serious for theA¹Π state owing to severe departures from harmonic behavior in thev= 2 andv= 3 levels.     

SG－1FEL放大器实验中的频率和功率测量

介绍了曙光一号自由电子激光（ＳＧ－１ＦＥＬ）放大器实验中对输出微波功率高达１４０ＭＷ的信号的频率和功率的测量。分析了ｘ射线和微波器件（定向耦合器、衰减器）的窄脉冲响应对测试结果的影响。     

Photophysical characteristics of polyaniline with photochromic azobenzene side groups

Photochromic characteristics and optical molecular reorientation in conducting polymer such as polyaniline derivatives containing photochromic azobenzene moieties (PAPNPAPOA) in side chain are studied. Changes in the UV—vis absorption, refractive index, thickness, contact angle and morphology of these films after irradiation of a linearly polarized light with a wavelength of 365nm are measured. The trans-cis isomerization of PAPNPAPOA is proved irreversible even after withdrawing the UV light for a long time. That the structure of main-chain attends by the trans-cis isomerization of side-chain is confirmed by the absorption and the solution colour during the UV irradiation. These effects are discussed by taking the trans-cis isomerization of azobenzene into consideration.     

北京同步辐射装置3B1B光束线和生物光谱实验站

３Ｂ１Ｂ光束线是北京同步辐射装置（ＢＳＲＦ）３Ｂ１光刻束线的一条分支束线，其光路和布局如图１所示．从北京正负电子对撞（ＢＥＰＣ）储存环３Ｂ１弯转磁铁处引出的同步辐射水平线偏振光，光源水平方向发散角为±３．７５ｍｒａｄ，竖直方向发散角为±０．２ｍｒａｄ，在距源１３．５ｍ处由一块柱面准直扫描镜Ｍ１反射后，水平方向的汇聚角为±１．２５ｍｒａｄ，竖直方向发散角不变．在距源２４ｍ处，有一块可升降的旋转抛物面反射镜Ｍ２．它降下时，光通过供其他实验站使用；升起时，将光反射聚焦于上方０．６ｍ处生物光学实验站光栅…     

Density of states of substoichiometric TiN1−x

The electronic states of substoichiometric TiN_1–x are studied by the CPA method and both the partial and total densities of states (DOS) are calculated. The results reveal that with increasing vacancy concentrationx the Fermi levelE _F moves to higher energies and the DOS atE _F,g(E _F), increases linearly. The calculated L_{II, III} X-ray spectra of Ti compare well with experiment.Work supported by the Research Institute for Powder Metallurgy, Sumperk, Czechoslovakia.The author is indebted to Dr. B. Velický, CSc for suggestion of the method to solve the Soven's equation. The financial assistance of the Research Institute for Powder Metallurgy, umperk, Czechoslovakia is gratefully acknowledged.