Evidence for a biogenic, microorganismal origin of rock varnish from the Gangdese Belt of Tibet

In the present study we examined material from the Ashikule Basin of Tibet. Chemical analyses were performed by use of energy dispersive X-ray spectroscopy and electron probe microanalysis to clarify whether the varnish layers that had developed on the surface of the rhyolite are indeed composed of varnish bodies and silica glaze. Electron microscopic analyses revealed that the surface of the varnish is covered both by filamentous hyphae bacterial and cocci-shaped forms. Within the varnish mineral layer in those samples two forms of bacteria-like microorganisms exist; cocci as tightly packed bacterial aggregates [within varnish bodies], and bacillus-like microorganisms [within the varnish matrix, that surrounds the varnish bodies]. The bacillus-like forms are embedded in a network of filaments that have diameters between 35 and 45 nm. These bacilli with the surrounding filaments are assumed to have been involved in biofilm formation (synthesis of extracellular polymeric substances) prior to their live burial. We concluded that the formation of the varnish layers was for the most part biogenically driven by microorganisms.     

基于液体基质材料的有机电致发光器件的制备及性能分析

利用液体基质材料9-(2-ethylhexyl)carbazole(EHCz)掺杂有机染料分子5,6,11,12-tetraphenyl-nathacene(rubrene)制备了具有液体发光层的有机电致发光器件,其结构为:ITO/PEDOT:PSS/EH Cz:rubrene/Cs2CO3/ITO,PEDOT:PSS...     

Global regularity for modified critical dissipative quasi-geostrophic equations

We consider the n-dimensional modified quasi-geostrophic (SQG) equations

t_∂θ + u . ∇θ + κΛαθ = 0,${\partial }_t\theta \hspace{0.17em}+\hspace{0.17em}u\hspace{0.17em}.\hspace{0.17em}\nabla \theta \hspace{0.17em}+\hspace{0.17em}\kappa {\Lambda }^{\alpha }\theta \hspace{0.17em}=\hspace{0.17em}0,$

u = Λα-1 R^⊥θ$u\hspace{0.17em}=\hspace{0.17em}{\Lambda }^{\alpha -1}\hspace{0.17em}{R}^{\perp }\theta$

with κ > 0, α ∈ (0,1] and θ₀ ∈ W1, ∞ (?ⁿ). In this paper, we establish a different proof for the global regularity of this system. The original proof was given by Constantin, Iyer, and Wu [5], who employed the approach of Besov space techniques to study the global existence and regularity of strong solutions to modified critical SQG equations for two dimensional case. The proof provided in this paper is based on the nonlinear maximum principle as well as the approach in Constantin and Vicol [2].     

纳米复合永磁Pr9Fe74Co12B5Snx(x=0, 0.5)的磁化行为与磁黏滞性

用熔体快淬法制备了纳米复合永磁样品Pr₉Fe₇₄Co₁₂B₅ 与Pr₉Fe₇₄Co₁₂B₅Sn_0.5，分析了样品的起始磁化、反磁化过程，测得样品的总磁化率、可逆磁化率以及样品的磁黏滞性.结果表明，两样品在室温下均表现为单一硬磁相磁化行为，在低温下表现为双相行为，且由于添加Sn后使晶粒均匀化从而导致样品低温下的双相行为更加明显.添加Sn后引起样品中软磁相含量和软磁相晶粒尺寸的增加，使磁化反转中可逆磁化部分增多，且使反磁化形核场降低.磁黏滞性研究表明，热激活体积与软磁相晶粒的大小有关. 关键词： 纳米复合永磁 磁化反转 磁粘滞     

k＜1时Cartan-Hartogs域上的极值问题

本文讨论两种类型的极值问题,其中一种类型的极值问题可以认为是复平面上经典的Schwarz引理在高维的一个推广;另一种类型的极值是某空间上的度量,可以用来考虑域的双全纯等价分类问题．在本文中,k＜1时Cartan-Hartogs域与单位超球间的极值与极值映照被得到。     

采用拉曼光谱技术研究纳米锐钛矿到金红石的相转变

采用化学沉淀法制备出40nm的锐钛矿，并用拉曼光谱对纳米和块体锐钛矿到金红石的相转变过程进行了研究。实验结果表明：对于块体锐钛矿，在950℃保温1h，金红石的特征峰446cm^-1开始出现，随着温度的升高，金红石的特征峰446，610和231cm^-1继续增强，锐钛矿的特征峰639，515和397cm^-1逐渐减弱。在1100℃保温1h，锐钛矿转变为金红石；对于纳米锐钛矿，在900℃保温1h后几乎全部转变为金红石，比块体（微米级）锐钛矿到金红石的相转变温度降低了200℃。     

钩藤中异钩藤碱在TLC原位的FT-SERS研究

本文报道了将薄层色谱（TLC）与傅里叶变换表面增强拉曼散射（FT－SERS）联用，获得了中草药钩藤中的异钩藤碱光谱研究的新方法。研究表明，在薄层原位，2.5μg钩藤总碱可将异钩藤碱等8种生物碱完全分离。应用薄层原位的薄层色谱傅里叶变换表面增强拉曼散射（TLC－FT－SERS）技术，获得异钩藤碱分子的特征振动谱带，进而阐述了样品分子在银胶表面的吸附模式，异钩藤碱以分子中氧化吲哚基团上N原子的孤子电子对和吲哚环π电子共同吸附于银晶体微粒表面,1.615cm^-1与芳环骨架振动和氧化吲哚N－H变形振动相关的峰获得最大增强。说明TLC－FT－SERS对中草药化学成分进行高灵敏度示踪指纹检测的可靠性和优越性。     

C~*-代数的实完全等距映射

C*-代数的*-同构一定是(完全)等距映射,反之不然.本文证明了C*-代数的实完全等距映射能够完全决定C*-代数*-同构的结论.