In this paper we obtained the asymptotic formula of the orthogonal rational function on the unit circle with respect to the weight function μ(z) with preasigned poles, which are in the exterior of the unit disk.
Generalizations of the geometric construction that repeatedly attaches rectangles to a square, originally given by Myerson, are presented. The initial square is replaced with a rectangle, and also the dimensionality o...Generalizations of the geometric construction that repeatedly attaches rectangles to a square, originally given by Myerson, are presented. The initial square is replaced with a rectangle, and also the dimensionality of the construction is increased. By selecting values for the various parameters, such as the lengths of the sides of the original rectangle or rectangular box in dimensions more than two and their relationships to the size of the attached rectangles or rectangular boxes, some interesting formulas are found. Examples are Wallis-type infinite-product formulas for the areas of p-circles with p > 1.展开更多
Dimethyltin dichloride-dibenzyl sulfoxide,（（CH3）2SnCl2·O=S（CH2C6H5）2）,crystallizes in the orthorhombic space group P212121 with a superstructure of dimensions a = 11.9290（1）,b = 19.50490（1）,c = 55.7390...Dimethyltin dichloride-dibenzyl sulfoxide,（（CH3）2SnCl2·O=S（CH2C6H5）2）,crystallizes in the orthorhombic space group P212121 with a superstructure of dimensions a = 11.9290（1）,b = 19.50490（1）,c = 55.7390（6） ; Z = 28. The geometry of the five-coordinated tin atom in each of the seven independent adduct molecules is a square pyramid that is displaced towards a cis-trigonal bipyramid; the extent of displacement along the Berry pseudorotation pathway ranges from 20 to 45%.展开更多
This article generalizes the famous Wallis’s formula for k ≥ 0 , to an integral over the unit sphere Sn-1. An application to the integral of polynomials over Sn-1 is discussed.
采用硅胶柱色谱分离风城稠油中的胶质,结合元素分析、红外光谱(FT-IR)、核磁共振(NMR)、X射线光电子能谱分析(XPS)等方法分析其结构组成,并用~1 H NMR/IR法计算胶质的平均结构参数和平均分子式。结果表明:风城稠油中胶质为含有杂环芳烃...采用硅胶柱色谱分离风城稠油中的胶质,结合元素分析、红外光谱(FT-IR)、核磁共振(NMR)、X射线光电子能谱分析(XPS)等方法分析其结构组成,并用~1 H NMR/IR法计算胶质的平均结构参数和平均分子式。结果表明:风城稠油中胶质为含有杂环芳烃、长碳链烷烃及N,O,S等杂原子的极性分子,其中O元素主要以醚氧健的形式存在,N原子多以吡咯和吡啶形式存在;平均相对分子质量为3 773,平均分子中结构单元数为6.57,平均结构单元式为C_(39)H_(55)O_2N。采用分子动力学模拟计算胶质在甲苯和正庚烷中的聚集形态,结果表明正庚烷有利于胶质分子聚集态形成,甲苯有利于胶质分子分散。展开更多
文摘In this paper we obtained the asymptotic formula of the orthogonal rational function on the unit circle with respect to the weight function μ(z) with preasigned poles, which are in the exterior of the unit disk.
文摘Generalizations of the geometric construction that repeatedly attaches rectangles to a square, originally given by Myerson, are presented. The initial square is replaced with a rectangle, and also the dimensionality of the construction is increased. By selecting values for the various parameters, such as the lengths of the sides of the original rectangle or rectangular box in dimensions more than two and their relationships to the size of the attached rectangles or rectangular boxes, some interesting formulas are found. Examples are Wallis-type infinite-product formulas for the areas of p-circles with p > 1.
文摘Dimethyltin dichloride-dibenzyl sulfoxide,（（CH3）2SnCl2·O=S（CH2C6H5）2）,crystallizes in the orthorhombic space group P212121 with a superstructure of dimensions a = 11.9290（1）,b = 19.50490（1）,c = 55.7390（6） ; Z = 28. The geometry of the five-coordinated tin atom in each of the seven independent adduct molecules is a square pyramid that is displaced towards a cis-trigonal bipyramid; the extent of displacement along the Berry pseudorotation pathway ranges from 20 to 45%.
文摘This article generalizes the famous Wallis’s formula for k ≥ 0 , to an integral over the unit sphere Sn-1. An application to the integral of polynomials over Sn-1 is discussed.
文摘采用硅胶柱色谱分离风城稠油中的胶质,结合元素分析、红外光谱(FT-IR)、核磁共振(NMR)、X射线光电子能谱分析(XPS)等方法分析其结构组成,并用~1 H NMR/IR法计算胶质的平均结构参数和平均分子式。结果表明:风城稠油中胶质为含有杂环芳烃、长碳链烷烃及N,O,S等杂原子的极性分子,其中O元素主要以醚氧健的形式存在,N原子多以吡咯和吡啶形式存在;平均相对分子质量为3 773,平均分子中结构单元数为6.57,平均结构单元式为C_(39)H_(55)O_2N。采用分子动力学模拟计算胶质在甲苯和正庚烷中的聚集形态,结果表明正庚烷有利于胶质分子聚集态形成,甲苯有利于胶质分子分散。
