叶轮机械设计自变数在内外环壁面上的限制条件及轴流式叶轮机械S1流面的翘曲

本文利用中心流面法的概念,指出叶轮机械的设计白变数在内、外环壁面上应有附加的限制条件,并导得其具体简明方程。同时,还定性地分析了S₁流面的翘曲情况。     

超导临界温度理论(Ⅰ)

本文求出了Eliashberg方程在T=T_c时的解,得到了下面的临界温度级数表示式: 其中α₀(μ^*),α₁(μ^*)等系数是μ^*的函数.此式表明,T_c不仅依赖于λ,〈ω²〉和μ^*,而且依赖于有效声子谱α²F(ω)的各级矩〈ω²n〉.这是区别于前人的T_c公式最重要的一点。这说明像McMillan以及Allen和Dynes的T_c公式不仅是近似的,而主要是他们没有能正确地概括出α²F(ω)对T_c的影响.     

Fiber-optic infrared reflectance spectroelectrochemical studies of osmium and ruthenium nitrosyl porphyrins containing alkoxide and thiolate ligands

We have examined the redox behavior of the osmium and ruthenium compounds (OEP)M(NO)(OEt) and (OEP)M(NO)(SEt) (OEP = octaethylporphyrinato dianion; M = Os, Ru) by cyclic voltammetry and infrared spectroelectrochemistry. The compound (OEP)Os(NO)(OEt) undergoes a single reversible oxidation process in dichloromethane. In contrast, the thiolate compound (OEP)Os(NO)(SEt) undergoes a net irreversible oxidation resulting in formal loss of the SEt ligand. Extended Hückel calculations on crystal structures of these two compounds provide insight into the nature of their HOMOs. In the case of the alkoxide compound, the HOMO is largely metal centered, with 70% of the charge located in the metal's orbital and approximately 25% on the porphyrin ring. However, the HOMO of the thiolate compound consists of a pi bonding interaction between the metal dxz orbital and the px orbital on the sulfur, and a pi antibonding interaction between the metal d orbital and a pi* orbital on NO. The redox behavior of the Ru analogues have been determined, and are compared with those of the Os compounds.     

Self-assembled chiral superstructures composed of rigid achiral molecules and molecular scale chiral induction by dopants

We explore the phase behavior of a rigid achiral bent-core model system. Nematic and smectic phases form at higher densities, whereas micelles and columns composed of chiral clusters of these molecules self-assemble at lower densities. No nucleation mechanism requiring transient chirality is possible in the formation of these chiral superstructures due to the rigid achiral nature of the substituents. We show the chiral micelles are minima of the potential energy surface using energy minimization and parallel tempering simulations. Chiral dopants were found to induce the system to adopt a consistent chiral twist direction, the first molecular scale computer simulation of this effect.     

使用色散可调啁啾光纤光栅在常规单模光纤中实现超过100km,10Gb/s的转输 *

报道了用简单的应力方法使均匀光栅成为线性啁啾光纤光栅的技术 ,并推导出了相应理论 ,发现最大色散补偿带宽与色散的乘积近似为常数 .在常规单模光纤G652,10Gb/s系统中实现超过100km的色散补偿 .     

Proteomic characterization of plasma‐derived clotting factor VIII–von Willebrand factor concentrates

Proteomic methods were used to identify the levels of impurities in three commercial plasma‐derived clotting factor VIII‐von Willebrand factor (FVIII/VWF) concentrates. In all three concentrates, significant amounts of other plasma proteins were found. In Octanate and Haemoctin, two concentrates developed in the 1990s, the major impurities identified were inter‐α inhibitor proteins, fibrinogen and fibronectin. These two concentrates were also found to contain additional components such as clotting factor II (prothrombin) that are known activators of FVIII. In Wilate, a recently developed FVIII/VWF concentrate, the amount of these impurities was significantly reduced. Batch‐to‐batch variations and differences between three investigated products were detected using iTRAQ, an isotope labeling technique for comparative MS, demonstrating the potential value of this technique for quality control analysis. The importance of thorough proteomic investigations of therapeutic FVIII/VWF preparations from human plasma is also discussed.     

三维光存储中折射率失配引起的球差补偿

为实现三维光存储中折射率失配引起的球差补偿,建立了光学存储系统模型,获得了折射率失配引起的波前偏差函数与存储深度的表达式.采用泽尔尼克循环多项式对波前偏差函数进行补偿展开.在双光子荧光和单光子共焦荧光读出方式下,均可获得读出荧光强度与存储深度的关系:在折射率失配引起的球差未得到补偿矫正的情况下,存储深度在200 μm左右读出荧光强度基本上下降为零;当折射率失配引起的初级球差被补偿矫正后,读出荧光强度随存储深度的下降得到较好改善;当折射率失配引起的二级球差被补偿矫正后,存储深度在1 mm内存储点强度随深度基本上没有明显地变化.并且对像差补偿方法进行了具体地分析.     

Unexpected nitrosyl-group bending in six-coordinate [M(NO)](6) sigma-bonded aryl(iron) and -(ruthenium) porphyrins.

The six-coordinate nitrosyl sigma-bonded aryl(iron) and -(ruthenium) porphyrin complexes (OEP)Fe(NO)(p-C(6)H(4)F) and (OEP)Ru(NO)(p-C(6)H(4)F) (OEP = octaethylporphyrinato dianion) have been synthesized and characterized. Single-crystal X-ray structure determinations reveal an unprecedented bending and tilting of the MNO group for both [MNO](6) species as well as significant lengthening of trans axial bond distances. In (OEP)Fe(NO)(p-C(6)H(4)F) the Fe-N-O angle is 157.4(2) degrees, the nitrosyl nitrogen atom is tilted off of the normal to the heme plane by 9.2 degrees, Fe-N(NO) = 1.728(2) A, and Fe-C(aryl) = 2.040(3) A. In (OEP)Ru(NO)(p-C(6)H(4)F) the Ru-N-O angle is 154.9(3) degrees, the nitrosyl nitrogen atom is tilted off of the heme normal by 10.8 degrees, Ru-N(NO) = 1.807(3) A, and Ru-C(aryl) = 2.111(3) A. We show that these structural features are intrinsic to the molecules and are imposed by the strongly sigma-donating aryl ligand trans to the nitrosyl. Density functional-based calculations reproduce the structural distortions observed in the parent (OEP)Fe(NO)(p-C(6)H(4)F) and, combined with the results of extended Hückel calculations, show that the observed bending and tilting of the FeNO group indeed represent a low-energy conformation. We have identified specific orbital interactions that favor the unexpected bending and tilting of the FeNO group. The aryl ligand also affects the Fe-NO pi-bonding as measured by infrared and (57)Fe M?ssbauer spectroscopies. The solid-state nitrosyl stretching frequencies for the iron complex (1791 cm(-)(1)) and the ruthenium complex (1773 cm(-)(1)) are significantly reduced compared to their respective [MNO](6) counterparts. The M?ssbauer data for (OEP)Fe(NO)(p-C(6)H(4)F) yield the quadrupole splitting parameter +0.57 mm/s and the isomer shift 0.14 mm/s at 4.2 K. The results of our study show, for the first time, that bent Fe-N-O linkages are possible in formally ferric nitrosyl porphyrins.     

高温高密度氦的压缩特性及其结构的分子动力学模拟

用分子动力学方法和不同参数的指数 6势函数计算了T =30 4K的高密度氦的等温压缩线和能量分布 .给出了能精确描述高密度氦原子间相互作用的指数 6势函数优化参数 .并用优化的势函数计算了高密度氦T =30 0K和T =2 98K的等温压缩线 ,计算结果和实验值非常吻合 .进一步用优化的势函数模拟了高温高密度氦的状态方程及其结构 ,发现当把 ρ限定为 1 .6 0g /cm³ 时 ,其径向分布函数的第 2个峰将在 2 0 0 0～ 30 40K区间消失 ,表明此时发生了固 液相变过程 .