Synthesis,structure, spectroscopic and magnetic properties of a novel two-dimensional copper(II) complex Na2[Cu(pba)] · 6H2O [pba = 1,3-propylenebis(oxamato)]

The copper(II) complex Na₂[Cu(pba)] · 6H₂O has been synthesized and its structure determined. It consists of a novel two-dimensional network of [Cu(pba)]^2– anions connected to each other through the sodium ion as a bridge. Spectroscopic and magnetic properties have been measured and a spin distribution calculation has been carried out with the GAUSSIAN-94. Theoretical calculations indicate the rather larger spin density on nitrogen atoms should be responsible for the satellite lines appearing beside the main hyperfine coupling signs of copper(II). The antiferromagnetic interaction may be due to the intermolecular interaction and/or different copper(II) ions through the Na⁺ bridge in the same layer.     

作业成本法数学模型的创新

随着企业产品价格竞争愈演愈烈，成本的合理分配、计算日显重要，但在间接费用的分摊上，传统成本会计对成本信息反映失真的局限性日益显露，会计理论界和实务界开始寻求一种新的准确的成本计算方法，作业成本法应运而生。本将由作业成本法基本原理推导出其数学模型，并将对其数学模型进一步改进，建立比较数学模型。使作业成本法向实际应用更进一步。     

BP神经网络在上海住宅市场需求预测中的应用

人工神经网络是近期发展最快的人工智能领域研究成果之一 ,本文在介绍 BP神经网络的有关原理的基础上 ,建立了一个上海住宅市场的 BP神经网络模型 ,并通过该模型对上海住宅市场的需求进行了预测和分析 .分析结果表明人工神经网络方法在住宅市场需求预测中的应用是可行的并且是有效的 .     

Yellow‐light‐emitting cyano‐substituted poly[(1,3‐phenylene vinylene)‐alt‐(1,4‐phenylene vinylene)] derivative: Its synthesis and optical properties

A soluble cyano‐substituted poly[(1,3‐phenylene vinylene)‐alt‐(1,4‐phenylene vinylene)] derivative ( 9 ) was synthesized and characterized. Comparison between 9 and its model compound ( 10 ) showed that the chromophore in 9 remained to be well defined as a result of a π‐conjugation interruption at adjacent m‐phenylene units. The attachment of a cyano substituent only at the β position of the vinylene allowed the maximum electronic impact of the cyano group on the optical properties of the poly(p‐phenylene vinylene) material. At a low temperature (?108 or ?198 °C), the vibronic structures of 9 and 10 were partially resolved. The absorption and emission spectra of a film of 9 were less temperature‐dependent than those of a film of 10 , indicating that the former had a lower tendency to aggregate. A light‐emitting diode (LED) based on 9 emitted yellow light (λ_max ≈ 578 nm) with an external quantum efficiency of 0.03%. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3149–3158, 2003     

Transport properties of acetone aqueous solutions: molecular dynamics simulation and NMR studies

Two quantities η_rel and are applied to study the nonideal acetone–water association mixture. An all-atom acetone model and a TIP5P water model have been adopted for molecular dynamics simulation. We study the transport properties of the system comparing the 's of strong hydrogen bond and weak contact based on transport properties, MD simulations together with NMR experimental data and find good agreement of concentration dependence, which exhibits the cooperation effect.     

Resonance-stabilized phenoxy-like radicals formed by NO-mediated mono-nitration of coumarins containing a hydroxy group

Stable aminoxyls and an iminoxyl were observed by spin trapping and EPR techniques during the nitration of coumarins containing a hydroxy group by nitric oxide. The trapped free radicals are deduced to be the resonance stabilized phenoxy-like radicals. The mechanisms for the nitrations are suggested.     

高功率LDA紧密侧面抽运Nd:YLF两级双程离轴放大系统实验研究

 介绍了一台10mm口径两级双程离轴放大系统，实现了对5mm×5mm口径光束的激光放大，耦合系统采用高功率LDA紧密侧面直接抽运棒状Nd:YLF方式。分析并实验研究了在不同抽运电流、放大脉冲与放大器LDA抽运时刻的不同延时及不同注入能量条件下，放大系统及光束每次放大时放大特性的规律。实验得到：在放大系统5mm×5mm软光阑处注入1.58mJ能量时，放大系统可输出129.2mJ能量，能量提取效率达到19.5%，满足该系统的设计指标。     

聚焦慢速高荷态重离子束微束斑X射线源

利用电子束离子源(EBIS)或者电子束离子陷阱(EBIT)产生的慢速高电荷态重离子束轰击金属靶面,离子束与靶面作用并复合辐射特征X射线;并将高荷态离子束采用离子光学系统会聚为微细束后再与靶面作用,能够辐射出微米甚至亚微米级、纳米级的微束斑X射线.本文介绍这一新型微束斑X射线源的结构、机理及其特性等.     

RuH2和RuN2电子组态与光谱性质的从头计算

用量子化学从头算方法在B3LYP/6 311G 的水平上 ,研究了RuH2 和RuN2 可能的电子组态和光谱性质 .结果表明 ,RuH2 的3 B2 和5Σ-态对应于静电作用的物理吸附态 .RuN2 的一重态和三重态的计算结果跟钌单晶面上的实验值相接近 .而RuN2 在C∞v对称性时 ,五重态5Σ-的计算频率比实验值稍低 .在C2v对称性时 ,五重态的计算频率值则更低 ,3 B2 和5A1态不能稳定存在