用粘土矿物合成4A型分子筛

A型分子筛的结构、合成和鉴定,以前已有报道。近年A型分子筛在我国石油、化工、冶金、电子技术、医疗卫生等部门中广泛应用,需要量愈来愈大。但由于在合成分子筛过程中耗用大量烧碱、氢氧化铝、水玻璃等     

Phase Retrieval from 4N−4 Measurements: A Proof for Injectivity

We prove by means of elementary methods that phase retrieval of complex polynomials p of degree less than N is possible with 4N − 4 phaseless Fourier measurements of p and p′. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

基于“否定假设法”设计综合与实践活动——以“一张A4纸的故事”为例

<正>1研究缘起数学是一门充满创造性的学科,纵观其发展历史,尽是数学家在挫折中不断创造的过程.丘成桐指出:“数学上最大的进步不在于解决难题,因为这样只会使某些研究领域完结,而在于开辟全新的各式各样的问题以供探索.”[1]然而,中小学生对数学学习的感知则多是按照既定规则分析并解决那些源于课本、出自教师或印在试卷上的问题.无论是从培养创造性人才的国家战略出发,还是从促进学生理解数学的学科要求着眼。     

A q-congruence for a truncated 4φ3 series

Czechoslovak Mathematical Journal - Let $${Phi _n}(q)$$ denote the nth cyclotomic polynomial in q. Recently, Guo, Schlosser and Zudilin proved that for any integer n &gt; 1 with n ≡ 1...     

Group of automorphisms of the ring ℤA4

The structure of the group of automorphisms of the integer group ring of the group A₄ is studied in terms of a semidirect product. We show that the Zassenhaus conjecture on the structure of automorphisms of integer group rings of finite groups for the group Aut ?A₄ holds.     

A NOTE ON THE RELATIVE CANONICAL IMAGE OF A NON－HYPERELLIPTIC FIBRATION OF GENUS 4

ＡＮＯＴＥＯＮＴＨＥＲＥＬＡＴＩＶＥＣＡＮＯＮＩＣＡＬＩＭＡＧＥＯＦＡＮＯＮ－ＨＹＰＥＲＥＬＬＩＰＴＩＣＦＩＢＲＡＴＩＯＮＯＦＧＥＮＵＳ４￥ＣＨＥＮＺＨＩＪＩＥＡｂｓｔｒａｃｔ：Ｔｈｉｓｐａｐｅｒｉｎｖｅｓｔｉｇａｔｅｓｔｈｅｒｅｌａｔｉｖｅ１－ｃａ...     

CHINESE ANNALS OF MATHEMATICS Vol.4 Ser.A No.4 CONTENTS AND ABSTRACTS

兀aounary Polynomial SPline InterPolation with班idPoint Condition.W叭g几哪召入刁”g(王建忠)(WuhanU垃ver滋ty) In this Pa详r,the author studies thel朗unary和lynomial sPllne in怕rPOla桩on with midpointinterPolation eonditions.The theorem of existence and uniqueness ises七abl坛hed,and the estimates forthe interPolation errors are obtalned. This ty邵of interPOlation may be applled to even degTee laounary interPOlation,wlii“hw朗rarelydjsCussed.p(二)很adiCals of Alternative Rings皿aZh记a(…     

A New 4 × 4 AKNS Spectral Problem and Its Associated Integrable Decomposition of the AKNS Equation

A new approach to construct a new 4×4 matrix spectral problem from a normal 2×2 matrix spectral problem is presented.AKNS spectral problem is discussed as an example.The isospectral evolution equation of the new 4×4 matrix spectral problem is nothing but the famous AKNS equation hierarchy.With the aid of the binary nonlino earization method,the authors get new integrable decompositions of the AKNS equation. In this process,the r-matrix is used to get the result.     

A construction of D-optimal designs for N≡2 mod 4

D-optimal design of order 6 is used to construct D-optimal designs of order 42 and 66.     

手帕纸中的数学问题

妈妈买回来一大包"心相印"牌手帕纸,我拿起一小包就要往口袋里装.爸爸忙指着包装袋上的"产品规格:21cm×21cm 10张×2层"问我:"你能解释这两道乘法算式吗?"     

A Markoff-type chain for the view-obstruction problem for spheres in ℝ4

In the view-obstruction problem, congruent, closed, convex bodies centred at the points in ⁿ are expanded uniformly until they block all rays from the origin into the open positive cone. The central problem is to determine the minimal blocking size. In the case of spheres of diameter 1, this value is denoted byv(n) and is known for dimensionsn=2,3. Here we show that and obtain a Markoff type chain of isolated extreme values.     

A Family of Asymmetrical Orthogonal Arrays with Run Sizes 4p^2

Nowadays orthogonal arrays play important roles in statistics, computer science, coding theory and cryptography. The usual difference matrices are essential for the construction of many mixed orthogonal arrays. But there are also many orthogonal arrays, especially mixed-level or asymmetrical which can not be obtained by the usual difference matrices. In order to construct these asymmetrical orthogonal arrays, a class of special matrices, so-called generalized difference matrices, were discovered by Zhang（1989, 1990, 1993） by the orthogonal decompositions of projective matrices. In this article, an interesting equivalent relationship between the orthogonal arrays and the generalized difference matrices is presented. As an application, a family of orthogonal arrays of run sizes 4p2, such as L36（6^13^42^10）, are constructed.