A nonnormal look at polychoric correlations: modeling the change in correlations before and after discretization

Two algorithms for establishing a connection between correlations before and after ordinalization under a wide spectrum of nonnormal underlying bivariate distributions are developed by extending the iteratively found normal-based results via the power polynomials. These algorithms are designed to compute the polychoric correlation when the ordinal correlation is specified, and vice versa, along with the distributional properties of latent, continuous variables that are subsequently ordinalized through thresholds dictated by the marginal proportions. The method has broad applicability in the simulation and random number generation world where modeling the relationships between these correlation types is of interest.     

邻井距离随钻电磁探测系统的设计与实现

虚拟二维激光雷达是激光雷达扩展应用的组成部分,可以结合3D场景点云特征进行二维激光雷达扫描障碍物模拟。提出根据光线传导特征建立积分方程得到了在多障碍物场景下的激光雷达图生成的解析解,利用AutoCAD与Visual C#联合编程的方法进行了虚拟激光雷达的实现。最后,实验结果与真实二维激光雷达比对,虚拟激光雷达能从3D场景中准确提取物体的位置和距离信息。     

Influence of the bridging ligand on the substitution behaviour of dinuclear Pt(II) complexes. An experimental and theoretical approach

A series of dinuclear Pt(II) complexes of the type [Pt2(N,N,N',N'-tetrakis(2-pyridylmethyl)diamine(H2O)2]4+ were synthesized. Acid-base titrations, and concentration and temperature dependent stopped-flow measurements of the reaction with chloride were performed to study the thermodynamic and kinetic behaviour of the dinuclear bridged complexes. The results indicate that there is a clear interaction between the two Pt(II) centres, which becomes weaker as the aliphatic chain increases in length. From a certain chain length onwards, the Pt(II) centres become independent of each other and exhibit identical thermodynamic and kinetic properties. The experimental results are discussed in reference to structures obtained by DFT (BP86/LACVP*) calculations.     

LaH分子的X1∑+态的势能函数

应用原子分析反应静力学原理导出ＬａＨ分子的电子状态和可能的离解极限,考虑相对论紧致有效势ＰＣＥＰ（Ｒｅｌａｔｉｖｉｓｔｉｃ Ｃｏｍｐａｃｔ Ｅｆｆｅｃｔｉｖｅ Ｐｏｔｅｎｔｉａｌ）近似下,用ＱＣＩＳＤ方法计算了ＬａＨ分子基态Ｘ＾１Σ＾＋的平衡几何Ｒｅ和离解能Ｄｅ为２．１２５Ａ和２．６２３ｅＶ,并在计算出来的一系列背地里点势能基础上,用正规方程组拟合Ｍｕｒｒｅｌｌ－Ｓｏｒｂｉｅ（Ｍ－Ｓ）势能函数,得     

铜蒸气激光器扩散系数的研究

推导了铜蒸气激光器带电粒子的双极扩散系数。结合铜蒸气激光器动力学模型对铜蒸气激光器动力学过程中的铜亚稳态粒子热扩散去激发及带电粒子双极扩散进行了分析。定量地给出了粒子热扩散项对铜亚稳态粒子密度及电子的双极扩散对电子密度的影响。     

Dynamic emulation of mechanical loads using a vector-controlledinduction motor-generator set

This paper addresses the problem of electronic emulation of both linear and nonlinear mechanical loads using a vector-controlled induction machine dynamometer. It is shown that a basic emulation scheme where the dynamometer torque demand is derived from the inverse dynamics of the emulated load is not generally viable, especially if the emulated load is part of a closed-loop speed control system. A new feedforward speed-tracking control scheme for the dynamometer is presented, which preserves the load dynamics and allows for emulation of a large class of nonlinear loads. An experimental rig is described using vector-controlled induction machines as the drive motor and dynamometer, and experimental results showing excellent emulation of both linear and nonlinear load dynamics are presented     

Isomerization of (all‐E)‐Cucurbitaxanthin A

Cucurbitaxanthin A (=(all‐E,3S,5R,6R,3′R)‐3,6‐epoxy‐5,6‐dihydro‐β,β‐carotene‐5,3′‐diol; 1 ) was submitted to thermal isomerization and to I₂‐catalysed photoisomerization. The structure of the main reaction products (9Z)‐ ( 2 ), (9′Z)‐ ( 3 ), (13Z)‐ ( 4 ), and (13′Z)‐cucurbitaxanthin A ( 5 ) was determined by their UV/VIS, CD, ¹H‐NMR, and mass spectra.     

Aesculaxanthin,a New Carotenoid Isolated from Pollens of Aesculus hippocastanum

From the pollens of Aesculus hippocastanum, a new apocarotenoid was isolated as the main carotenoid and, based on the spectroscopic data, identified as (all-E,3R)-3-hydroxy-6′-apo-β-caroten-6′-al ( 4 , aesculaxanthin). In addition, (all-E)-lutein ( 3 ) and (all-E)-β-citraurin ( 5 ) were isolated. Furthermore, 6 (aesculaxanthol) was prepared by reduction of 4 with NaBH₄ and tentatively identified as natural carotenoid.     

Preparation of Partially Acetylated Carotenoids

Partially acetylated carotenoids were prepared from fully acetylated carotenoids by reaction with NaBH₄, and were characterized by UV/VIS, CD, ¹H‐NMR and mass spectra. The 3,6′‐diacetate, 3′,6′‐diacetate, and 6′‐acetate 10 – 12 , respectively, of (6′R)‐capsanthol (=(3R,3′S,5′R,6′R)‐β,κ‐carotene‐3,3′,6′‐triol; 4 ) were obtained from (6′R)‐capsanthol‐3,3′,6′‐triacetate ( 9 ), and the 3‐ and 3′‐acetates 13 and 14 , respectively, of 4 from (6′R)‐capsanthol 3,3′‐diacetate ( 8 ). The utility of this method was also demonstrated by the preparation of zeaxanthin and lutein monoacetates 16, 19 , and 20 .