On C classifications of hyperbolic vector fields

In this paper we study smooth classification of hyperbolic vector fields based on their linear approximations only and obtain the following. On Rⁿ, n?5, with only two kinds of exceptions, any two hyperbolic vector fields with generic nonlinear parts and where A_i are n×n matrices, are C¹ conjugate to each other if and only if A₁ and A₂ are strictly similar, and they are C¹ orbitally equivalent if and only if A₁ and A₂ are similar.     

Degradation of pyrene and characterization of<Emphasis Type="Italic">Saccharothrix</Emphasis> sp. PYX-6 from the oligotrophic Tianchi Lake in Xinjiang Uygur Autonomous Region,China

Bacterial strain PYX-6 that utilizes anthracene,phenanthrene, or pyrene for carbon and energy sources for growth was isolated from a non-polluted lake (Tianchi Lake) in Xinjiang Uygur Autonomous Region of China. Its morphology, physiological and biochemical properties, cell wall pattern and G C mol% content of DNA molecules were characterized. The 16S rRNA gene of strain PYX-6 was sequenced and analyzed for similarities to related bacterial species. Results indicated that strain PYX-6 is a member of the Genus Saccharothrix, and the strain was named Saccha-rothrix sp. PYX-6. When pyrene was the sole carbon source in cultural medium, the strain PYX-6 assimilated pyrene for growth and 0.005% of yeast extract stimulated pyrene degradation and assimilation. The optimal pH of cultural medium and the optimal shaking frequency during cultivation were 6-8 and 200 r/m, respectively. It was found that the disappearance of pyrene in medium occurred before significant growth of strain PYX-6 took place. Phthalic acid, benzylacetic acid, and benzylpropenoic acid were detected as catabolic intermediates during pyrene degradation with mass spectroscopy and this result indicated that Saccharothrix sp.PYX-6 adopted a pathway that is different from the pathway of the previously reported pyrene-degrading Mycobacterium sp. PYR-1.     

Mutual attraction of laser beams in plasmas: braided light

The energy loss of slow ions during grazing scattering from a LiF(100) surface as a function of the projectile atomic number Z1 is observed to show oscillations similar to those occurring in metals. A model of stopping of ions in an electron gas where screening is calculated from density functional theory reproduces well the experimental data. The same model gives good agreement with the energy loss obtained in transmission experiments performed with H and He projectiles. Analysis of these results allows us to gain new insights in the stopping of slow ions in ionic crystals.     

基于XRD的镀锌钝化膜残余应力试验研究

利用XRD技术测试了镀锌钝化膜结合界面的残余应力，同时通过电解抛光法检测了其厚度方向残余应力的分布规律，分析了残余应力对镀锌钝化膜结合强度的影响. 试验结果表明，镀锌钝化膜的残余应力均表现为压应力，并随着基体表面残余应力的增大而减小；钝化膜在2—10μm厚度方向的残应力为-274.5—-428.3MPa，其应力为梯度分布；镀锌钝化膜与基体的界面结合强度与其残余应力成反比，减小薄膜残余应力，有利于提高镀锌钝化膜与基体的结合强度. 关键词： X射线衍射法(XRD) 镀锌钝化膜 结合强度 残余应力     

铁磁/有机半导体/铁磁系统的电流自旋极化性质研究

根据有机半导体中的电流自旋极化注入和输运实验现象，理论上研究了铁磁/有机半导体/铁磁系统的电流自旋极化性质.考虑到有机半导体的具体特性，从自旋扩散理论和欧姆定律出发，得到了系统的电流自旋极化率.假设自旋极化子和不带自旋的双极化子为有机半导体中的载流子.通过计算发现，极化子为实现有机半导体中电流极化注入和输运的有效自旋载流子，即使它只占总载流子很少一部分.还进一步研究了自旋相关界面电阻和电导率匹配以及有机半导体长度等因素对系统电流自旋极化的影响. 关键词： 自旋电子学 自旋注入 有机半导体 极化子     

衬底温度对MOCVD法沉积ZnO透明导电薄膜的影响

研究了衬底温度对MOCVD技术制备的ZnO薄膜的微观结构和光电特性影响. XRD和SEM的研究结果表明，衬底温度对ZnO薄膜的微观结构有显著影响，明显的形貌转变温度大约发生在175℃，低于175℃，薄膜呈镜面结构，晶粒为球状，高于177℃的较高温度范围，薄膜从“类金字塔”状的绒面结构演化为“岩石”状显微组织；随着温度增加，薄膜的晶粒尺寸明显增大.绒面结构的未掺杂ZnO薄膜具有17.96 cm²/V·s的高迁移率和3.28×10^-2 Ω·cm的低电阻率，对ZnO薄膜的进一步掺杂和结构优化有望应用于Si薄膜太阳电池的前电极. 关键词： MOCVD ZnO薄膜 透明导电氧化物 太阳电池     

(2+1)维非对称 Nizhnik-Novikov-Veselov系统的新映射解及其局域结构

映射法是一种非常经典、有效和成熟的求解非线性演化方程的方法，其最大的特点是可以有多种不同形式的设解，使得最终求得的解丰富多彩. 利用改进的 Riccati 方程映射法和变量分离法，得到了(2+1)维非对称 Nizhnik-Novikov-Veselov 系统的新显式精确解.根据得到的孤波解，构造出该系统的峰孤子和分形孤子等局域结构，研究了两个孤立波的“追碰”现象. 关键词： 改进的映射法 (2+1)维非对称 Nizhnik-Novikov-Veselov 系统 局域结构 “追碰”现象     

SrBi2Ta2O9/Bi4Ti3O12复合铁电薄膜的制备与特性研究

采用溶胶凝胶工艺在p-Si衬底上制备了SrBi₂Ta₂O₉/Bi₄Ti₃O₁₂复合铁电薄膜. 研究了SrBi₂Ta₂O₉/Bi₄Ti₃O₁₂复合薄膜的微观结构与生长行为、铁电性能和疲劳特性. 研究表明: Si衬底Bi₄Ti< 关键词： 2Ta₂O₉')" href="#">SrBi₂Ta₂O₉ 4Ti₃O₁₂')" href="#">Bi₄Ti₃O₁₂ 复合铁电薄膜 溶胶凝胶工艺     

基于GIS的内蒙古中部区域洪水灾害风险评价

本文综合考虑自然以及社会的作用,从洪水危险性和社会易损性两个角度出发,选取地理高程、人口密度、人均GDP和历史灾情数据为指标,采用快易的叠加分析法对研究区(内蒙古中部)进行区域洪水灾害风险评价,实现了各种指标定性与定量的组合,得出研究区洪水灾害风险评价图.结果表明,研究区南部靠近黄河的河套平原地区,由于地势较为平缓、靠近河流、经济发达,洪水灾害风险较大.在研究区北部,由于经济不发达,人口较少,洪水灾害风险较小.与实际基本相符.