Clifford分析中Isotonic柯西型积分的边界性质

本文主要刻画了定义于偶数维欧氏空间中光滑曲面而取值于复Clifford代数的isotonic柯西型积分的边界性质.对具有H(o|¨)lder密度函数的isotonic柯西型积分,得到了Privalov定理和Sokhotskii-Plemelj公式,并证明了多复变函数论中经典Bochner-Martinelli型积分的Privalov定理和Sokhotskii-Plemelj公式为其特殊情形.     

机械设计在CAD中图表资料的处理

机械设计中，有许多复杂的数据信息需要处理，本文主要探讨了齿轮传动中有关数据，表格和线圈的程序化处理方法。     

How delocalized is N,N,N',N'-tetraphenylphenylenediamine radical cation? An experimental and theoretical study on the electronic and molecular structure

The electronic and molecular structure of N,N,N',N'-tetraphenylphenylenediamine radical cation 1(+) is in focus of this study. Resonance Raman experiments showed that at least eight vibrational modes are strongly coupled to the optical charge resonance band which is seen in the NIR. With the help of a DFT-based vibrational analysis, these eight modes were assigned to symmetric vibrations. The contribution of these symmetric modes to the total vibrational reorganization energy is dominant. These findings are in agreement with the conclusions from a simple two-state two-mode Marcus-Hush analysis which yields a tiny electron-transfer barrier. The excellent agreement of the X-ray crystal structure analysis and the DFT computed molecular structure of 1(+) on one hand as well as the solvent and solid-state IR spectra and the DFT-calculated IR active vibrations on the other hand prove 1(+) adopts a symmetrical delocalized Robin-Day class III structure both in the solid state and in solution.     

Preparation of AChE Inhibitors From Jujubogenin

The advanced medical technology has lengthened the life expectancy of human beings.This makes some previously ignored diseases prominent, such as Alzheimer disease(AD). The low level of acetylcholine (ACh) in brain is considered to be one of mainreasons for suffering such memory loss disease. Thereby, how to elevate ACh level inbrain and enhance the cognition has become a main issue l'2. One of the approaches is toinvestigate acetylcholinesterase (AChE) inhibitors, which can prevent the hy…     

Suppression of excitation and spectral broadening induced by interactions in a cold gas of Rydberg atoms

We report on the observation of ultralong range interactions in a gas of cold rubidium Rydberg atoms. The van der Waals interaction between a pair of Rydberg atoms separated as far as 100,000 Bohr radii features two important effects: spectral broadening of the resonance lines and suppression of excitation with increasing density. The density dependence of these effects is investigated in detail for the S- and P-Rydberg states with principal quantum numbers n approximately 60 and n approximately 80 excited by narrow-band continuous-wave laser light. The density-dependent suppression of excitation can be interpreted as the onset of an interaction-induced local blockade.     

Electronic coupling in tetraanisylarylenediamine mixed-valence systems: the interplay between bridge energy and geometric factors

We have investigated three organic mixed-valence systems that possess nearly identical inter-redox site distances and differ by the nature of the bridging units benzene, naphthalene, and anthracene: the N,N,N',N'-tetra(4-methoxyphenyl)-1,4-phenylenene-diamine radical cation (1+), the 1,4-bis(N,N-di(4-methoxyphenyl)-amino)naphthalene radical cation (2+), and the 9,10-bis(N,N-di(4-methoxyphenyl)amino)anthracene radical cation (3+). The electronic interactions in these systems have been studied by means of gas-phase ultraviolet photoelectron spectroscopy, vis/NIR spectroscopy, and electronic-structure calculations. The experimental and theoretical results concur to indicate that the strength of electronic interaction decreases in the following order of bridging units: benzene > naphthalene > anthracene. This finding contradicts the usual expectation that anthracene is superior to benzene as a driving force for electronic communication. We explain these results in terms of a super-exchange mechanism and its strong dependence on steric interactions.     

关于求各向异性介质中电磁场的格林张量函数的一个方法

本文提出一个方法,来推求在(3)式中所定义的、在全空间中的格林张量函数。它有时亦称为对应微分方程的基本解。这个方法是以富氏变换为基础。由于问题的复杂性,我们不得不作某些近似。首先,把各向异性介质分为两类,一类是磁迴旋介质,另一类是电迴旋介质。对于磁迴旋介质,如铁氧体,取μ为张量而ε为标量。而对电迴旋介质,如等离子体,取ε为张量而μ为标量。其次,由于矩阵μ_p非常小(在(15)式中定义),我们可以把解展为μ_p的冪级数,并计算出一级近似。具体结果在式(23)、(25)、(28)、(32)和(33)中表示。最后对Г函数的物理意义和它的渐近展开式的有效范围作了讨论。     

Orientational Distribution of Fibres in Sheared Fibre Suspensions

Motion of fibres in sheared fibre suspensions is simulated numerically by using the lattice Boltzmann method. The orientational distributions of the fibres are presented for different Reynolds numbers, Stokes numbers, shear rate and fibre aspect ratio. Some computational results are compared with the experimental data of pipe flow, and the qualitative agreement is achieved. The results show that the orientational distributions are greatly affected by the Reynolds numbers, while relatively insensitive to the fibre aspect ratio. The Stokes number and shear rate have obvious influence on the orientation distribution.     

THREE-DIMENSIONAL VISCOUS FLOW THROUGH A ROTATING CHANNEL: A PSEUDOSPECTRAL MATRIX METHOD APPROACH

A Fourier–Chebyshev pseudospectral method is used for the numerical simulation of incompressible flows in a three-dimensio nal channel of square cross-section with rotation. Realistic, non-periodic boundary conditions that impose no-slip conditions in two directions (spanwis e and vertical directions) are used. The Navier–Stokes equations are integrated in time using a fractional step method. The Poisson equations for pressure and the Helmholtz equation for velocity are solved using a matrix diagonalization (eigenfunction decomposition) method, through which we are able to reduce a three-dimensional matrix problem to a simple algebraic vector equation. This results in signficant savings in computer storage requirement, particularly for large-scale computations. Verification of the numerical algorithm and code is carried out by comparing with a limiting case of an exact steady state solution for a one-dimensional channel flow and also with a two-dimensional rotating channel case. Two-cell and four-cell two-dimensional flow patterns are observed in the numerical experiment. It is found that the four-cell flow pattern is stable to symmetri cal disturbances but unstable to asymmetrical disturbances.     

湖北十堰红褐色条纹绿松石的谱学特征

条纹绿松石是湖北十堰绿松石市场出现的一种深受消费者喜欢的品种,该研究对象为一块基底为浅蓝绿色,条纹为红褐色的绿松石样品,红褐色条纹在浅缘蓝色基底上规律性分布。对样品进行显微观察、能谱仪成分测定、显微紫外-可见-近红外光谱仪测试和显微激光拉曼光谱仪测试。研究结果表明,样品的红褐色条带由呈近圆形的赤铁矿集合体在绿松石中规律性聚集形成,赤铁矿颗粒细小,呈圆点状、雪花状集合体在绿松石中浸染状分布;化学成分测试结果表明条带处比基底处铁含量高,且杂质矿物中FeO_T含量约为56.06%～59.13％;显微紫外-可见-近红外光谱显示杂质矿物中的致色离子主要为Fe3+,可见374 nm附近由Fe3+的d电子跃迁[6A₁→4E(4D)]所致的弱吸收、429和418 nm附近由Fe3+的d电子跃迁（6A₁→4E, 4A₁(4G)）所致的双吸收、475 nm附近和544 nm附近由Fe3+对｛[6A₁+6A₁→4T₁(4G)+4T₁(4G)]｝电子跃迁所致的弱吸收;杂质矿物的显微激光拉曼光谱在225,296,411,612,659和1 320 cm-1处显示赤铁矿的典型拉曼峰。条纹绿松石中杂质矿物的谱学特征表明该杂质矿物为赤铁矿。绿松石中的赤铁矿为绿松石矿床中的伴生矿物,绿松石中赤铁矿的存在为绿松石的产地鉴别以及古代绿松石的产地溯源提供数据支撑,条纹绿松石中杂质矿物赤铁矿的周期性出现表明绿松石形成环境的不稳定及周期性。