Hydrothermal Synthesis and Crystal Structure of Inorganic-organic Hybrid Compound [H3NC2H4NH2]VOPO4

An inorganic-organic hybrid compound, [H_3NC_2H_4NH_2]VOPO_4 was synthesized by means of the hydrothermal method. It was crystallized in a monoclinic system, a space group P2_1/c, with the crystal cell parameters: a=0.92285(11) nm, b=0.72994(9) nm, c=0.98495(11) nm, β=101.280(3)°, V=0.65067(13) nm~3, M_r=223.02 g/mol, D_c=2.277 g/cm~3, Z=4, R=0.0315, ωR=0.0865, GOF=1.085. The VO_5N octahedra chains are corner-linked by PO_4 tetrahedra; the VO_5N octahedra are all trans-linked with V—O bonds being alternately short and long. The monoprotonated ethylenediamine was intercalated between the layers with one end coordinating to V and the other end as an H-bond donor interacting with a terminal O atom of PO_4 from a neighboring sheet. The elementary analysis, infrared spectrum characters and thermal stability were also given.     

Squares of Primes and Powers of 2

 As an extension of the Linnik-Gallagher results on the “almost Goldbach” problem, we prove, among other things, that there exists a positive integer k ₀ such that every large even integer is a sum of four squares of primes and k ₀ powers of 2. (Received 7 September 1998; in revised form 3 May 1999)     

某些N-芳基-(1′-羧甲基二茂铁基)乙酰胺的合成与表征

以二茂铁为起始原料,经多步反应,合成了1,1’-二茂铁二乙酸酐,后者与取代苯胺反应,合成了十四种新型二茂铁二乙酸单酰胺,并由元素分析、红外光谱和核磁共振氢谱鉴定了化合物的结构。此外,对二茂铁二羧酸单酰胺与过渡金属的螯合反应进行了初步研究。     

Synthesis and structure of a novel complex [LCo(OH)2(HCO3)CoL]2[(NC)5Cr(CN)Cr(CN)2].4H2O

A novel complex containing a (μ-bicarbonato)-bis(μ-hydroxo)dicobalt(II) cation and a (μ-cyano)dichromium(III) anion has been obtained and characterized by single crystal X-ray diffraction. The cations have a confacial bioctahedral structure and the anion contains an octahedral Cr(CN)₆³⁻ unit bridging to the second Cr which has trigomal planar geometry.     

Synthesis,spectral and magnetic properties of binuclear copper(II)/nickel(II) and copper(II) complexes bridged by glyoximate groups

Three new dinuclear complexes, [(tmen) (H2O)2Ni (Hdmg)(dmg)Cu]·ClO4, [(dien)(H2O)Ni (Hdmg)(dmg) Cu]·ClO4 and [(tmen)Cu(Hdmg)(dmg) Cu] ClO4·H2O (H2dmg=dimethylglyoxime, tmen=tetramethylene diamine), have been prepared. Variable-temperature- magnetic susceptibility measurements (75–300K) on the complexes reveal the presence of intramolecular antiferromagnetic interactions through the oximate bridges. The formation of mononuclear, dinuclear complexes has been confirmed by spectrophotometry.     

Norm inequalities related to operator monotone functions

Let A,B be positive semidefinite matrices and any unitarily invariant norm on the space of matrices. We show for any non-negative operator monotone function f(t) on , and for non-negative increasing function g(t) on with g(0) = 0 and , whose inverse function is operator monotone. Received: 1 February 1999     

RIBLL中的TOF测量

描述了一种为兰州放射性核束流线(AIBLL)研制的时间拾取装置.次级束引起闪烁薄膜发光,椭球面镜聚焦,光电倍增管读出,CAMACTDC记录次级束的飞行时间.其时间分辨可以达到140ps,计数率可以达到10⁸pps.     

无穷维L1空间至连续函数空间的等距逼近问题

证明了无穷维Ｌ~１空间至连续函数空间的等距逼近问题的回答是否定的．     

一类赋p范空间上的等距扩张问题

该文讨论了Ｌ~ｐ（Ω,Ｘ）（０＜ｐ＜１）的一类子空间上的单位球面等距扩张问题．     

完备非紧具非负曲率流形之拓扑结构

本文给出完备非紧具非负曲率的Ｒｉｅｍａｎｎ流形具有限拓扑型的一个简单证明