改进欧拉算法在油液光谱分析趋势预测中的应用

基于原子发射光谱油液分析是大型机械设备磨损状态监测与故障诊断的重要技术,由于灰预测理论在趋势预测方面具有明显的优势,文章利用油液原子发射光谱分析结果,结合灰预测理论,建立了某综合传动油液中金属元素Fe趋势变化的灰预测模型。在模型参数辨识求解上首次引入了改进欧拉算法,解决了避免原灰预测模型在实际应用过程中出现的预测结果主要依赖于第一个实测值的问题,使得预测结果更准确。将该算法结合原子发射光谱分析Fe元素浓度的阈值制定,有效地捕捉到综合传动发生故障的征兆信息,及时采取措施防止综合传动的故障,具有很好的推广应用价值。     

Application of Gray codes to the study of the theory of symbolic dynamics of unimodal maps

In this paper we provide a closed mathematical formulation of our previous results in the field of symbolic dynamics of unimodal maps. This being the case, we discuss the classical theory of applied symbolic dynamics for unimodal maps and its reinterpretation using Gray codes. This connection was previously emphasized but no explicit mathematical proof was provided. The work described in this paper not only contributes to the integration of the different interpretations of symbolic dynamics of unimodal maps, it also points out some inaccuracies that exist in previous works.     

2-Groupoid Enrichments in Homotopy Theory and Algebra

The use of groupoid enrichments in abstract homotopy theory is well known and classical. Recently enrichments by higher-dimensional groupoids have been considered. Here we will describe enrichment by 2-groupoids with respect to the Gray tensor product and will examine several examples (2-groupoids, 2-crossed complexes, chain complexes, etc.) from an elementary view-point. The enrichment of the category of chain complexes is examined in detail and questions of the existence of analogues of classical constructions (categories over B, under A, etc.) are explored.     

一类Z2k-线性的二元码

我们记Tk为Galois环GR（2^k,m)到Z2^k的迹映射，ξ是GR（2^k,m)中的本原元，ξ2^m-1=1,ιk,m={0,1,ξ，…，ξ2^m-2}，来讨论一类Z2^k-线性码{Tk(a0x 2^k-2a1x^3 2^k-1,a2x^5) b|a0∈GR(2^k,m),a1∈ιk,m 2ιk,m,a2∈ιk,m,b∈Z2^k}x∈ιk的广义Gray映射下的象所构成的二元码，这类二元码也具有很好的参数性质，优于一些已知的二元码，例如广义的Kerdock码或广义的Delsarte-Goethals码。     

沙地沙枣花挥发油和净油化学成份的研究

沙枣(Elaeagnus angustufolia L.)又名香柳、桂香柳,属胡颓子科胡颓子属的乔木,具有抗旱,耐盐碱,抗风沙的特性,分布于我国     

On binary reflected Gray codes and functions

The binary reflected Gray code function b is defined as follows: If m is a nonnegative integer, then b(m) is the integer obtained when initial zeros are omitted from the binary reflected Gray code of m.This paper examines this Gray code function and its inverse and gives simple algorithms to generate both. It also simplifies Conder's result that the jth letter of the kth word of the binary reflected Gray code of length n is

     

Equipartitions of measures in

A well-known problem of B. Grünbaum (1960) asks whether for every continuous mass distribution (measure) on there exist hyperplanes dividing into parts of equal measure. It is known that the answer is positive in dimension (see H. Hadwiger (1966)) and negative for (see D. Avis (1984) and E. Ramos (1996)). We give a partial solution to Grünbaum's problem in the critical dimension by proving that each measure in admits an equipartition by hyperplanes, provided that it is symmetric with respect to a -dimensional affine subspace of . Moreover we show, by computing the complete obstruction in the relevant group of normal bordisms, that without the symmetry condition, a naturally associated topological problem has a negative solution. The computation is based on Koschorke's exact singularity sequence (1981) and the remarkable properties of the essentially unique, balanced binary Gray code in dimension ; see G. C. Tootill (1956) and D. E. Knuth (2001).

     

超声搅拌悬浮液进样FAAS法测定铁皮石斛(枫斗)中的铜

研究了铁皮石斛 (枫斗 )中铜的分析方法。样品在 80± 2℃烘干 4h ,研磨过 2 0 0目筛 ,然后加入 5mL 0 1 5 %琼脂悬浮液 ,用超声搅拌混匀后直接上机测定。测定结果与传统湿法一致 ,t检验表明两者无显著性差异 ,相对误差小于 0 96%。该法简便、快速、准确。     

Structural stability and stabilization of solutions of the reversible three‐component Gray‐Scott system

This paper is concerned with the structural stability and stabilization of solutions to the three‐component reversible Gray‐Scott system under the Dirichlet or Neumann boundary conditions defined in a bounded domain of for 1 ≤ n ≤ 3. We prove that each solution depends on changes in a coefficient of the ratio of the reverse and forward reaction rates for the autocatalytic reaction as well as proving the continuous dependence on the initial data. We also prove that under Dirichlet's boundary conditions, the system is stabilized to the stationary solution by finitely many Fourier modes.