Two types of loop algebras and their expanding Lax integrable models

Though various integrable hierarchies of evolution equations were obtained by choosing proper U in zero-curvature equation U_t-V_x+[U,V]=0, but in this paper, a new integrable hierarchy possessing bi-Hamiltonian structure is worked out by selecting V with spectral potentials. Then its expanding Lax integrable model of the hierarchy possessing a simple Hamiltonian operator \widetilde{J} is presented by constructing a subalgebra \widetilde{G } of the loop algebra \widetilde A₂. As linear expansions of the above-mentioned integrable hierarchy and its expanding Lax integrable model with respect to their dimensional numbers, their (2+1)-dimensional forms are derived from a (2+1)-dimensional zero-curvature equation.     

Ce-EU-1分子筛的合成和表征

采用水热法,以溴化六甲双铵（HMBr2）为模板剂,硅溶胶、偏铝酸钠为硅铝源,以六水硝酸铈为铈源合成了稀土Ce-EU-1分子筛,并通过XRD、FTIR、紫外-可见漫反射光谱、热重分析（TG-DTG）和氮气吸附-脱附等测试手段对合成样品的孔道结构、物化性能及Ce的存在状态进行了表征。XRD结果表明,合成样品不仅具有很高的纯度和结晶度,为典型的立方有序排列的EU-1结构,而且部分Ce已取代Si或Al进入微孔分子筛的骨架。样品的FTIR图谱在980cm-1附近有明显的Si—O—Ce特征吸收峰,证明Ce存在于分子筛的骨架中。紫外-可见漫反射图谱显示,在253nm附近出现O—Ce之间的电子跃迁特征峰,进一步证明了Ce进入了分子筛骨架。氮气吸附-脱附结果表明了Ce的掺入对分子筛的物化性能和孔道结构产生了影响。同时考察了镧系其他金属离子（Ln：La、Nd、Sm和Gd）对EU-1分子筛的影响,发现随着镧系离子半径的减小,Ln-EU-1分子筛的相对结晶度逐渐降低,晶胞体积减小。     

Preparation and properties of SnS film grown by two-stage process

SnS films have been prepared by a novel two-stage process. It involved sputtering of Sn film on glass substrate and sulfurization of the thin metallic tin precursor layers in a vacuum furnace. The X-ray diffraction results showed that the SnS layers had orthorhombic structure and (0 4 0) preferential growth is more and more obvious with the increase of sulfurization time. The SnS film obtained by this work shows high optical absorption efficiency, and the film has a direct optical band gap of about 1.3 eV. The films show p-type conductivity and the resistivity of SnS film decreased obviously under illumination.     

Volume polarization holographic recording in thick phenanthrenequinone-doped poly(methyl methacrylate) photopolymer

Volume polarization holographic recording in phenanthrenequinone-doped poly (methyl methacrylate) photopolymer is obtained. Photoinduced birefringence in a 2 mm thick sample is measured by a phase-modulated ellipsometry. The birefringence induced in this material by linearly polarized beam at 514 nm reaches 1.2×10(-5). In addition, ability for recording volume polarization grating using two different polarization configurations is demonstrated and compared. The experimental results show that the diffraction efficiency of the hologram reaches to ～40% by using two orthogonal circularly polarized beams.     

拉曼光谱对新石器时期白石斧的研究

本文采用显微拉曼光谱技术 ,对云南省永仁县菜园子出土的新石器时期白石斧的表面和截面进行了测试研究 ,结合矿物拉曼谱确定了石斧白色和黑色物质的成分。通过对白石斧截面拉曼谱的分析 ,得出了石斧拉曼主峰 (46 2cm- 1 )的强度随深度变化情况的散点图 ,实验结果发现 ,石斧表面的腐蚀层厚约为 40 0 μm。石斧截面拉曼谱给出了与石斧埋葬年代和周围环境有关的信息     

微波电子回旋共振等离子体增强化学气相沉积法沉积氟化非晶碳薄膜的研究

使用三氟甲烷和苯的混合气体,利用微波电子回旋共振等离子体增强化学气相沉积法制备了F/C比在0.11—0.62之间的α-C∶F薄膜.研究了微波功率对薄膜沉积和结构的影响,发现微波功率的升高提高了薄膜的沉积速率,降低了薄膜的F/C比,也降低了薄膜中CF和CF₃基团的密度,而使CF₂基团的密度保持不变.在高微波功率下可以获得主要由CF₂基团和C=C结构组成的α-C∶F薄膜.薄膜的介电频率关系(1×10³—1×10⁶Hz)和损耗频率关系(1×10²—1×10⁵Hz)均呈指数规律减小,是缺陷中心间简单隧穿引起的跳跃导电所致.α-C∶F薄膜的介电极化主要来源于电子极化 关键词： 氟化非晶碳薄膜 ECR等离子体沉积 键结构 介电性质     

Instanton effects on the interaction potential between light quarks and the isomultiplet mass splitting of baryons

On the basis of current assumptions of instanton theory we derive strictly the explicit dependence on the masses and spins of the instanton induced potential between a pair of light quarks in baryons, namelyV ₁₂=γ+β(m _* ^1+α )(m _* ^2+α )η(1-σ ₁ησ ₁), wherem _i ^* andσ _i (i=1.2) are respectively the mass and Pauli spin of theith quark. On the additional basis of the MIT bag model, we obtain γ=c/R ³ and β=b/R ³>0, and α>0 is independent of the radiusR of the baryon. The magnitudes of the parametersb and α are also estimated. The MIT bag model is improved by taking into account this potential. Isomultiplet mass splitting formulas are derived in good agreement with experiment.     

Observation of large CP violation in the neutral B meson system

We present a measurement of the standard model CP violation parameter sin2 phi(1) based on a 29.1 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. One neutral B meson is fully reconstructed as a J/psi K(S), psi(2S)K(S), chi(c1)K(S), eta(c)K(S), J/psi K(L), or J/psi K(*0) decay and the flavor of the accompanying B meson is identified from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we determine sin2 phi(1) = 0.99+/-0.14(stat)+/-0.06(syst). We conclude that we have observed CP violation in the neutral B meson system.     

红光InAlAs量子点的结构和光学性质

利用ＭＢＥ方法在（００１）衬底上成功地生长密度大、尺寸小、发红光的ＩｎＡｌＡｓ／ＡｌＧａＡｓ量子点结构。通过原子力显微镜观察表明,ＩｎＡｌＡｓ量子的密度和大小都随覆盖厚度的增加而增大;发现Ａｌ原子的表面迁移率决定ＩｎＡｌＡｓ量子点的形貌,光荧光谱证实了量子点的发光峰值在红光范围,并结合形貌的统计得到了量子点的发光峰展宽主要昌受量子点的横向尺寸影响。     

高温高压下纳米金刚石粉的特性研究

 研究了炸药爆轰合成的纳米金刚石粉在高温（约1 600 K）、高压（5.2 GPa）条件下的行为。将纳米金刚石粉与粉末合金（Ni₇₀Mn₂₅Co₅、100^#）混合、压制成圆片,与合金片 （Ni₇₀Mn₂₅Co₅）和人造石墨片一起交替放入高温高压合成腔体内,进行高温高压实验。实验结果表明：在高温高压条件下,纳米金刚石粉不能长大,反而石墨化了;在相同的高压和保温时间条件下,随着温度的降低,纳米金刚石粉的石墨化程度减弱,纳米金刚石粉的纳米颗粒长大,可长成0.1 mm尺寸的金刚石颗粒（温度为1 070 K左右）。而在此条件下,人造石墨不能合成金刚石,一般金刚石晶体要变成石墨相。这进一步表明,纳米金刚石颗粒表面的活性使得它可以在较低的温度下长成较大颗粒的金刚石。