Marked length rigidity of rank one symmetric spaces and their product

In this paper we show that if two Zariski dense representations, from a group G into Iso(X) where X is rank one symmetric space, have the proportional marked length spectrum, then they are conjugate. As a generalization we show that a Zariski dense representation into the isometry group of the product of rank one symmetric spaces is determined by the marked cross ratio.     

Understanding Symmetric and Asymmetric DNA Patterns by Water Flow on a Solid Surface

In order to use DNA for making molecular device, specific DNA patterns on a solid surface should be constructed. In this paper, we will show that the random interactions between the DNA segments and the solid surface play an important role in the final symmetric and asymmetric DNA patterns obtained by water flow.     

Influence of the Native Oxide Layer on the Silicon Surface During Initial Stages of Nitridation

 Thin SiO₂ layers were produced by thermal oxidation of Si wafer material. To study the effect of nitridation on the oxide layers, the specimens were nitrided in a furnace at high temperature. Non-destructive ion beam analysis was performed to determine changes in the elemental concentrations and depth profiles of the major components. In particular, N and O concentrations were measured using the non-resonant nuclear reactions ¹⁴N(d, α)¹²C and ¹⁶O(d, p)¹⁷O, respectively. To obtain depth profiles of the as-prepared and nitrided specimens, the samples were measured with RBS and heavy ion elastic recoil detection analysis. The ion beam analyses revealed an increase in thickness of the SiO₂ layers with temperature. The specimens nitrided at 1200 °C were almost free of N. Surface topology investigations with scanning electron microscopy revealed concentric annular artificial patterns at the surfaces. In the centre of the pattern, only silicon was measured. Additionally, a band consisting of Si, O, and N surrounding the pattern was discovered. The findings are in agreement with specimens prepared at higher temperatures. Received June 19, 2000. Revision December 9, 2000.     

Density functional studies of AnF6 (An=U,Np, and Pu) and UF6−nCln (n=1–6) using hybrid functionals: geometries and vibrational frequencies

We have compared the performance of widely used hybrid functionals for calculating the bond lengths and harmonic vibrational frequencies of AnF₆ (An=U, Np, and Pu) and UF_6?nCl_n (n=1–6) molecules using “small‐core” relativistic effective core potentials and extended basis sets. The calculated spectroscopic constants compare favorably with experimental data for the bond lengths (average error ≤ 0.01 Å) and vibrational frequencies (average error ≤ 7 cm^?1) of the AnF₆ molecules. The experimental vibrational frequencies of the stretching modes were available for most of the UF_6?nCl_n (n=1–6) molecules. The calculated vibrational frequencies are in good agreement with the experimental data to within 4.6 cm^?1 and 7.6 cm^?1 for selected Becke1 and Lee, Yang, Parr (B1LYP), and Becke3 and Perdew, Wang (B3PW91) functionals, respectively. We conclude that one can predict reliable geometries and vibrational frequencies for the unknown related systems using hybrid density functional calculations with the RECPs. The geometries and vibrational frequencies of the UF_6?nCl_n (n=1–6) molecules that have not been determined experimentally are also presented and discussed. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 2010–2017, 2001     

Metric Properties of Factor Space of Molecular Shapes

Molecular shape equivalence classes defined with respect to equivalence of geometrical and topological properties are represented by logical models. Consequently, the factor space of molecular shapes is provided by a metric useful in shape comparisons.     

Nonmonotonic pattern of the critical percolation temperature due to variations of additive chain length in water-in-oil microemulsions

The nonmonotonic variation of the critical percolation temperature (T _c) of ternary nonionic (C₁₄E₅) water-in-oil microemulsions was studied as a function of the alkyl chain length of an ionic additive (n-alkyl sulfonate sodium salt). A thermodynamic approach shows the relationship between T _c and additive chain length, which is supplemented by a consideration of a possible molecular mechanism of the observed phenomenon. Received: 20 October 2000 Accepted: 7 November 2000     

对绿洲生态学范式的哲学思考

拟结合绿洲生态学研究在哲学理论方面的最新进展,对干旱区绿洲生态学范式进行分析,并对涉及到的绿洲生态系统平衡与非平衡,同质性与异质性,等级缀块等生态范式等问题加以探讨。     

港口城市形态与布局规律──以浙江省沿海港口城市为例

以浙江沿海港口城市为研究对象,通过对实地调查所取得的大量具体资料的分析,系统地探讨了浙江沿海港口城市发展的区域背景条件、优势条件和制约因素,分析了浙江沿海港口城市总体布局特征,内部结构形态和外部形态的演变发展规律,提出了浙江沿海港口城市形态与布局变化趋势,为港口城市进一步发展提供理论依据．     

Full hemispherical photoelectron diffraction and Fermi surface mapping

The routine measurement of full hemispherical photoemission intensity maps gives us the possibility for the combined investigation of structural and electronic phenomena at surfaces. As an example the growth of ultrathin films of Co on Cu(111) is studied as a function of film thickness. While X-ray photoelectron diffraction (XPD) shows the early appearance of stacking faults as a precursor of the hcp structure, Fermi surface maps reveal the very fast evolution of the Co Fermi surface that can be compared to measurements on a clean Co(0001) crystal. For the system O/Rh(111), XPD brings up important structural clues, relating changes in surface reactivity to small amounts of subsurface oxygen, which forces adjacent oxygen atoms to occupy new and more reactive adsorption sites. In the course of this last study we observed for the first time the weak backscattering signals in the angular pattern of adsorbate emission. These cone-like features are extremely sensitive to the adsorbate–substrate bond length.     

Indicator space configuration for early warning of violent political conflicts by genetic algorithms

Recognition of preconflict situations has a powerful potential for early warning of violent political conflicts. This paper focuses on the design and application of artificial neural networks as classifiers of preconflict situations. Achieving a desired level of performance of the neural network relies on the appropriate construction of recognition space (selection of indicators) and the choice of network architecture. A fast and effective method for the design of reliable neural recognition systems is described. It is based on genetic algorithm techniques and optimizes both the configuration of input space and the network parameters. The implementation of the methodology provides for increased performance of the classifier in terms of accuracy, generalization capacity, computational and data requirements. This revised version was published online in June 2006 with corrections to the Cover Date.