自内射环的余Hopf性

本文证明了自内射环R是余Hopf的当且仅当R满足stablerangeone.于是得到了Varadarajan在[9]中的公开总是对于自内射环是成立的,即M_n(R)是余Hopf的当且仅当R是余Hopf的.作为应用证明了Goodeal的一个公开问题对于自内射正则环有肯定的回答.     

季戊四醇-偏苯三酸酐-环氧氯丙烷合成超支化聚合物

以季戊四醇为“中心核”,与1,2,4-偏苯三甲酸酐和环氧氯丙烷反应合成超支化碱溶性聚酯,利用合成聚合物分子外围的羧基与甲基丙烯酸缩水甘油酯反应,在超支化聚合物分子外围引入反应性甲基丙烯酰氧基.研究了树脂组成对感光性和碱溶性的影响.结果表明:通过调整分子外围的羧基及反应性甲基丙烯酰氧基含量,可以获得较好的碱溶性和光固化性能.     

张量积的代数K－理论及其应用

本文研究了两个代数张量积的Ｇｒｏｔｈｅｎｄｉｅｃｋ群和Ｗｈｉｔｅｈｅａｄ群首先构作三个群同态，并证明：若Ｒ为增广Ａ－代数，则存在的子群Ｃ使得，并存在的子群Ｄ使得．然后给出在群代数和包络代数方面的应用，最后考虑的增广代数的情形．     

Electronic density distorsion of NiO2 due to intercalation by Li

High resolution measurements of Compton profiles of Li_xNiO₂ have been carried out using 60 keV photons at ESRF (Grenoble, France). Theoretical profiles are obtained using the plane wave expansion of wave functions calculated using ab-initio SCF method. Theory and experiment are in good agreement. We have further decomposed the charge density modification into a rigid charge transfer from lithium to e_g¹ states of NiO₂ and the distorsion of NiO₂ charge density mainly due to Ni–O bond changes resulting from lattice parameter change and Jahn-Teller effect.     

TA-EG-GMA合成超支化碱溶性感光聚合物

通过1,2,4-偏苯三酸酐和乙二醇反应合成超支化聚合物,利用合成聚合物分子外围的羧基与甲基丙烯酸缩水甘油酯反应,在超支化聚合物分子外围引入反应性甲基丙烯酰氧基.研究了树脂组成对感光性和碱溶性的影响.结果表明:调整反应物料配比及反应性甲基丙烯酰氧基含量,可以获得较好的碱溶性和光固化性能.     

Analysis of dark current contributions in mercury cadmium telluride junction diodes

An analytical approach to analyze the dark current–voltage (I–V) and dynamic impedance vs reverse bias voltage (R_d–V) characteristics of an HgCdTe junction diode is presented in this paper. Application to the experimental data is discussed to illustrate the approach. It is shown that the relative contributions of the various dark current contributing mechanisms viz. diffusion, generation–recombination, thermal trap assisted tunneling, band-to-band tunneling, avalanche multiplication and ohmic current component can all be isolated, if present.     

On the precision of calculations of initial state radiation in the LEP Z line-shape fits

Calculation of initial state radiation (ISR) in the fitting program MIZA and in the Standard Model program BHM is improved within the analysis of the Z line-shape measurements at LEP. The uncertainty on the determination of the Z line-shape parameters coming from the precision of ISR calculations is 2×10⁻⁴ on σ₀ and 0.1 MeV on m_Z and Γ_Z.     

Inclusive one- and two-jet cross sections in γγ reactions at e+e− colliders

We have calculated inclusive one- and two jet production in photon-photon collisions superimposing direct, single-resolved and double-resolved cross sections for center of mass energies of the LEP1, LEP2 and NLC range. The direct and single-resolved cross sections are calculated up to next-to-leading order. The double-resolved two-jet cross section is calculated only in LO with a k factor estimated from the NLO one jet cross section. Various differential cross sections as functions of transverse momenta and rapidities of the jets are evaluated.     

On the quark-antiquark potential at short distances

We investigate the static quark-antiquark potential up to distances of 8 lattice units for pure SU(2) gauge theory on lattices with anisotropic couplings. The action is the Wilson action with a coupling for time-like plaquettes which differs from those for space-like ones. Numerical simulations are performed in a large range of β The potential is obtained by fitting “cooled” Wilson loops with up to four exponential terms. An interpolation of the potentials by a sum of a perturbative term, a linear term and by lattice artifacts shows poor scaling in comparison with he isotropic case. If the coupling in the time-like region is reduced, the linear term is much smaller than in the isotropic case, and vice versa. Consequences for the bag picture for hadrons are discussed.     

可调节活动导叶的形状解析

贯流式水轮机的活动导叶和转轮叶片都是可调节的,活动导叶开度角γG与转轮叶片角φR的协联关系相当重要,协联关系对水轮机设计及运行能够提供有效的帮助.至目前为止,γG和φR的协联关系即协联工况只能在水轮机设计完成后通过模型试验得到。本文在给定转轮叶片角φR的情况下,通过对活动导叶叶栅流道进行形状解析,进而在设计平台上预测对应协联工况开度角γG.