Charmonium cross section from p—A production

Several extractions of the ?-N cross section from ? production in γ+A and h+A reactions have been attempted. We discuss these and the issue of charmonium formation using the recent data obtained by E866/NuSea.     

Thepp —p \bar p difference and the behaviour of phases at high energies

Predictions based on axiomatic field theory are obtained from the assumption that the difference between thepp and thep \(\bar p\) elastic scattering observed at the CERN ISR is caused by an “odderon-like” term in the scattering amplitude. A wide class of amplitudes violating the Pomeranchuk relation is considered. Contrary to common opinion, severe restrictions on the high-energy behaviour of the phase of the crossing-odd amplitude are shown to follow for the whole class. Less pronounced but still visible consequences follow for the phases of thepp andp \(\bar p\) amplitudes separately. We derive the corresponding high-energy bounds and correlations using the general frame of analyticity, crossing symmetry and unitarity. As a special case, the maximal odderon amplitude is discussed.     

类镓等电子序列PdⅩⅥ—TeⅩⅫ的4s^24p—4s4p^2,4s^24p—…

对类镓等电子序列ＧａⅠ－ＸｅⅩⅪⅤ离子４ｓ＾２４ｐ，４ｓ４ｐ＾２，４ｓ＾２５ｓ组态能级结构和组态相互作用进行了理论分析，找出沿等电子序列的变化规律。用我们提出的拟合公式预测ＳｎⅩⅩ－ＴｅⅩⅫ离子４ｓ＾２４ｐ，４ｓ４ｐ＾２，４ｓ＾２５ｓ组态能级，并给出４ｓ＾２４ｐ－４ｓ４ｐ＾２，４ｓ＾２４ｐ－４ｓ＾２５ｓ谱线波长和ＨＸＲ方法的理论计算振子强度，理论计算值与实验值进行了比较。     

Preparation and Transparent Property of the n—ZnO／p—Diamond Heterostructure

Heterostructures of an n-type ZnO film/p-type diamond film on the {111} crystalline diamond substrate have been prepared for the first time.The electrodes of the n-and p-type semiconductors are experimentally verified to be ohmic.The diode shows a good rectification characteristic and the ratio of forward current to the reverse current exceeded 200 within the range of applied voltages of -2 to 2V.The turn-on voltage of the diode is 0.34V and the highest current is about 5.0mA as the forward voltage reaches 2V.Moreover,the diode is optically transparent in the region of 500-700nm wavelength.     

p—Type Doping of GaN by Mg^＋ Implantation

Mg^ and Mg^ P^ were introduced into GaN by ion implantation.The structure and crystalline quality of the GaN samples were analysed by Rutherford backscattering and channelling spectormetry before(χmin=1.6%)and after implantation(χmin=4.1%),X-ray diffraction reveals the existence of implantation-induced damage in the case of post-implantation followed by rapid thermal annealing.The resistivtiy,average factor,carrier concentration and carrier mobility were measured by the Hall effect.The transformation from n-type to p-type for GaN was observed.     

p—HgCdTe反型层中子能带电子的基态能量

用变分自洽方法求解了ｐ－ＨｇＣｄＴｅ金属－绝缘体－半导体（ＭＩＳ）结构Ｎ型反型层子能带的基态能量Ｅ０及其与表面电子浓度的关系。计算中考虑了窄禁带半导体Ｈｇ１－ｘＣｄｘＴｅ带间相互作用所引起的非抛物带结构、波函数平均效应、共振缺陷态、Ｚｅｎｅｒ隧穿、以及电场在屏蔽长度内的衰减等因素，导出了子能带基态能量Ｅ０的计算公式并获得了与实验符合较好的结果。     

低压MOCVD生长GaN p—n结蓝光LED

简要报道了采用一种改进的低压金属有机化物化学气相沉积（ＬＰ－ＭＯＣＶＤ）方法制备ＧａＮｐ－ｎ结蓝光光发射二极管（ＬＥＤ），介绍了ＬＥＤ的基本特性，这种ＬＥＤ具有良好的Ｉ－Ｖ特性和光谱特性，室温下，在正向电压５Ｖ，正向电流３－２０ｍＡ的条件下，峰值波长为依Ｍｇ的掺杂浓度和退火条件的不同而不同，分别在４２５ｎｍ，４３５ｎｍ和４８０ｎｍ附近，发射谱的半峰宽约为５０ｎｍ。     

Preparation of p—n Junction Diode by B—Doped Diamond Film Grown on Si—Doped c—BN

A heterojunction diode has been fabricated by boron-doped p-type diamond thin film grown epitaxially on a silicon-doped n-type cubic boron nitride bulk crystal using the conventional hot filament chemical vapour deposition method.The ohmic electrode of Ti(50nm)/Mo(100nm)/Au(300nm)for the p-type diamond film and the bulk crystal of the c-BN were deposited by the rf planar magnetron method.Then the device was annealed at 410℃ in air for 1h in order to form ohmic metal alloy,The current-voltage characteristics of the heterojunction diode were measured and the result indicated that the rectification ratio reached 10^5,and the turn-on voltage and the highest current were 7V and 0.36mA,respectively.     

Colossal Magnetoresistive p—n Junctions of Te—Doped LaMnO3／Nb—doped SrTiO3

We have fabricated colossal magnetoresistive (CMR) p-n unctions made of Te-doped LaMnO3 and Nb_dopoed SrTiO3 with laser molecular beam epitaxy.The I-V characteristics of the La 0.9Te0.1MnO3/SrNb 0.01Ti0.99O3p-n junctions as a function of applied magnetic field(0-5T) wrer experimentally studied in the temperature range 77-300K.The results indicate that the p-n junction exhibited the CMR behaviour.The magnetoresistance (MR) is positive at 220K and 300K,while it displays a negative MR at 77K.For a positive bias.the MR ratios (ΔR/R0,ΔR=RH-R0)are 7.5% at 0.1T and 18% at 5T for 300K,5%at 0.1T and 33%at 5T for 220K,for 300K,5.1%at 0.1T and 15%at 3T for 220K-19%at 0.1T and -72% at 5T for 77K,The CMR behaviour of the p-n junction is different from those of the LaMnO3 compound family.     

NⅡ离子2p4f—2p3d辐射跃迁概率的理论研究

在全相对论理论框架下，利用多组态Dirac-Fock(MCDF)方法，系统计算了NⅡ离子2p4f—2p3d的辐射跃迁概率，得到的结果与已有实验值符合很好.具体计算中，详细分析了相对论效应、电子关联、弛豫效应、Breit相互作用和量子电动力学(QED)效应对能级精细结构及辐射跃迁概率的影响.结果表明：相对论效应、电子关联和弛豫效应对NⅡ 2p4f-2p3d辐射跃迁概率有很重要的影响,考虑了这些效应后计算值得到明显改善.     

RIE技术制备p—n结型GaN蓝光LEDs

自从Ｓ．Ｎａｋａｍｕｒａ等人成功地制备了ＧａＮ／ＧａＩｎＮ／ＡｌＧａＮ蓝、绿光ＬＥＤｓ以来,ＧａＮ及其相关化合物的材料生长和器件工艺得到了广泛地研究．由于ＧａＮ材料不同于传统的Ⅲ－Ⅴ族化合物半导体材料,因此其器件的加工工艺,如欧姆或肖特基接触的形成、...     

High Energy Elastic p and p p Differential Cross Sections

<正>(Updated September 2013.COMPAS group.IHEP,Protvino)Using new results from FNAL-COLLIDER-D0 experiment in pp elastic collisions at s~(1/2)=1.96 TeV[1],CERN-LHC-TOTEM experiment in p p elastic collisions at s~(1/2)=7,8 TeV[2-3]and PAO experiment in proton-air collisions at 57 TeV[4]the amplitudes of the elastic p p and p p collisions are investigated in a most broad region in s~(1/2)and t via three observables da/dt(s,t).σ~(tot)(s),and p(s).The summary of the database for dσ/dt(s,t)is presented in Figure 50.10.where projection of the dσ/dt(s~(1/2),t)to the(da/dt,—t)plane orthogonal to the s~(1/2)axis is displayed.     

Electroluminescence and Photoluminescence from Scored Si—Rich SiO2 Film／p—Si Structure

Electroluminescence(EL)is observed from the Au/Si-rich SiO2 film/p-Si diodes,in which the Si-rich SiO2 films are scroed deliberately by a diamond tip.The EL intensity of the scroed diode annelaed at 800℃ is about 6 times of that of the unscored counterpart,The EL sectrum of the usscored diode could be decomposed into two Gaussian luminescence bands with peaks at about 1.83 and 2.23eV,while for the EL spectrum of the scored diode,an additional Gaussian band at about 3.0eV appears,and the 1.83-eV peak increases significantly in intensity,The photoluminescence(PL) spectrum of an unscored Si-rich SiO2 film has only one band peaking at about 1.48eV,whereas the Pl spectrum of the scored one has two bands at about 1.48 and 1.97eV.We consider that the high-density defect regions produced by the scoring provide new luminescence centres and become some types of nonradiative centres in the Si oxide layer,which thus result in changes of the EL and PL spectra.     

On the reactions p + p↦p + Λ + K+ and p + p↦p + Σ0 + K+ near thresholds

The cross-sections for the reactions of the strange production p + p ↦ p + Λ + K⁺ and p + p ↦ p + Σ⁰ + K⁺ near thresholds of the final states pΛK⁺ and pΣ⁰K⁺ are calculated in the effective Lagrangian approach. Our approach is based on the dominant contribution of the one-pion exchange and strong interaction of the colliding protons in the initial state. The theoretical values of the cross-sections agree reasonably well with the experimental data. The polarization properties of the Λ- and Σ⁰-hyperons are discussed.