The negative magnetization and dielectric relaxation in (La0.3Pr0.7)1-xCaxCrO3 ceramics

The (La_0.3Pr_0.7)_1-xCa_xCrO₃ (x = 0, 0.1, 0.3 and 0.5) ceramics have been synthesized by a sol-gel method. The compounds crystalize in orthorhombic structure with space group Pnma at room temperature. The magnetic measurements confirm that the materials form canted antiferromagnetic (AFM) ordering from 254.1, 231.2, 118.5, 49.3 K for the samples of x = 0, 0.1, 0.3 and 0.5, accompanied by a spin reorientation transition at 191.4, 145.1, 55.8, 38.9 K because of the Pr³⁺-Cr³⁺ interaction. Meanwhile, a positive exchange bias effect is observed due to the antiparallel coupling between the Pr³⁺ and the canted AFM structure of Cr³⁺. The Néel temperature, compensation temperature as well as the coupling strength of Pr³⁺-Cr³⁺ monotonously decrease with the increase of Ca²⁺ concentration. For the samples of x = 0.1 and 0.3, there exists a field induced Pr³⁺-Pr³⁺ AFM ordering. By means of dielectric measurements, large permittivity at room temperature and dielectric relaxation are observed in all the samples. The permittivity is decreased and dielectric relaxation moves to low temperature range with the increase of Ca²⁺ concentration. A relaxor-like ferroelectric transition is observed in the measuring temperature range in Ca²⁺ doped samples.     

CAD/CAE技术在长春光机所的应用

叙述了CAD/CAE技术在长春光机所的应用、开发、交流和人材培养,展示了CAD/CAE技术作为第一生产力的巨大潜力和作用。     

试论股票流通配额制度

本文提出了一项关于金融体制转换的建议:实行股票流通与交换配额制度。方案的特点主要在以现实条件为依托,逐步打破资金统配,采用凭借流通券交易股票的方式,克服垄断和严重的资源浪费等资本主义发展中常见的痼疾。     

Properties of lnAsxP1-x layer formed by P-As exchange reaction on (001)lnP surface exposed to As4 beam

The P-As exchange reaction on InP surface exposed to As₄ beam was studied using photoluminescence (PL) and x-ray diffraction measurements as well as ultra-high vacuum scanning tunneling microscopy observation. It was found that as high as 90–95% of P can be exchanged by As and that the average depth of exchange reaction increases with the increase of As exposure time, being as deep as 5.5 ML for a long exposure. The splitting of PL peak takes place when the reaction depth exceeds 2 ML and the number of the split subpeaks increases with the increase of As exposure time. The PL peak splitting originates from the fluctuation of well thickness, caused by formation of InAs islands for strain relief during the exchange reaction.     

基于Netware IPX的后台实时通信

本文介绍了Ｎｅｔｗａｒｅｎ ＩＰＸ的特点及编程方法，详细论述了利用ＢＩＯＳ １ＣＨ中断实现网上工作站间的点对点、点对面的后台实时通信的思想和方法。     

5454铝水箱在洗氨塔内的应用

基于合成氨厂洗氨塔的换热设备碳钢水箱换热效果不理想的问题，提出了在洗氨塔内采用5454铝水箱替代碳钢水箱的解决方案，以增强水箱的换热效果，改善了塔内作业状况，提高了产气量，节约冷却用水量，同时又延长了水箱的使用寿命，减少水箱的清洗、更换次数，有良好的经济效益。通过相关的测量及计算数据，分析了此方案的可行性。     

A study of intramolecular electron exchange in copper-radical complexes involved in catalysis using ESR spectroscopy

ESR simulation and experimental results have been presented to show that transition metal-radical complexes can engage in intramolecular electron exchange and that the exchange gives rise to ESR asymmetric line broadening effect. Depending on the relative concentration of the redox-exchange pair, metal or radical-like spectrum can be obtained. Simulation results show that a metal-radical complex can be masked by its redox counterpart upto a relative concentration of 1:2 at a modest exchange rate of 3 x 10⁸/s. Asymmetric line broadening was predicted to occur upon such metal-radical complexation. Experimentally, a pronounced ESR asymmetric line broadening was observed for Cu(II) complexes of various redox-active ligands. Cu(II) complex with redox-inert ammonia, however, showed no such evidence. Ligand displacement experiments established the reversibility of metalradical complexation and the associated ESR line broadening.     

也谈Word与AutoCAD相互调用

分析了在实际应用中Word与AutoCAD间相互调用的必要性，分别对AutoCAD中插入Word文本，及Word中插入AutoCAD图形的方法进行了介绍，对使用WMF图形格式的方法进行了详细的分析。     

多媒体课件的模块化设计与数据交换

本文主要论述多媒体课件开发中如何运用模块化设计原理优化程序结构，对模块间数据交换的技术问题进行探讨，用时以Authorware为例阐述了以内部函数、外部文件及数据库进行数据交换的接口程序的编写方法。     

织物用聚酯酰胺热熔胶的研制

研究了以聚酯胶和聚酰胺胶为原料在催化剂的作用下加热共熔,通过大分子链交换反应制备织物用聚酯酰胺热熔胶的方法。用聚酯胶的溶剂对所得产品进行溶取试验并且通过红外光谱分析都证明了链交换反应的存在。用该法所得产品粘接强度大,既耐水洗又耐干洗,适用于粘合衬生产。