稀土配合物的核磁共振（NMR）系列研究（2）邻菲罗啉—甲基苯甲酸铕（Eu3＋）二、三元配合物的NMR和IR研究

本文报道了稀土铕（Ｅｕ３＋）与甲基苯甲酸（包括邻位ｏ－ＭＢＡ，间位ｍ－ＭＢＡ，对位ｐ－ＭＢＡ）及邻菲罗啉（ｐｈｅｎ）形成的二元和三元固体配合物的制备，对它们进行了元素分析，确定该配合物的组成为：二元：Ｅｕ（ＣＨ３Ｃ６Ｈ５ＣＯＯ）３，三元：Ｅｕ（ｐｈｅｎ）（ＣＨ３Ｃ６Ｈ５ＣＯＯ）３。对上述配合物的结构作了核磁共振氢谱（１ＨＮＭＲ）和碳谱（１３ＣＮＭＲ）的研究，并用红外光谱（ＩＲ）作了进一步确定     

稀土配合物的核磁共振（NMR）系列研究（2）：邻菲罗啉—甲基苯甲酸…

本文报道了稀土铕（Ｅｕ＾３＋）与甲基苯甲酸（包括邻位ｏ－ＭＢＡ，间位ｍ－ＭＢＡ，对位ｐ－ＭＢＡ）及邻菲罗啉（ｐｈｅｎ）形成的二元和三元固体配合物的制备，对它们进行了元素分析，确定该配合物的组成为：二元：Ｅｕ（ＣＨ３Ｃ６Ｈ５ＣＯＯ）３，三元：Ｅｕ（ｐｈｅｎ）（ＣＨ３Ｃ６Ｈ５ＣＯＯ）３。对上述配合物的结构作了核磁共振氢谱（＾１ＨＮＭＲ）和碳谱（＾１３ＣＮＭＲ）的研究，并用红外光谱（ＩＲ）作了进一步确定     

R－（Cu，Ni）二元和三元体系相图及相形成规律

根据Ｒ－（Ｃｕ，Ｎｉ）二元和三元体系的相图及其所存在的金属化合物，探讨了这些体系的相形成规律。     

部分稀土与邻苯二甲酸及邻菲罗啉三元配合物的荧光性质

研究了部分稀土与邻苯二甲酸及邻菲罗林的三元配合物（ＲＥ（ＨＬ）３．Ｌ１．３Ｈ２Ｏ）的荧光性质，并与稀土的二元配合物ＲＥ（ＨＬ）３进行了比较，探讨了邻菲罗林对Ｔｂ和Ｅｕ的三元配合物发射光谱的增强作用及Ｔｂ三元配合物的发光机理。在Ｔｂ（ＨＬ）３．Ｌ１．３Ｈ２Ｏ，由于ＨＬ＾－与Ｌ１能量的双重传递使Ｔｂ的荧光强度大为增强。     

Ni75Al10V15合金早期沉淀过程的原子尺度计算机模拟

基于二元合金沉淀动力学相场方程的微观离散格点形式建立三元体系模型,在倒易空间中求解方程.用此模型对实际三元Ni75Al10V15合金的早期沉淀过程进行了模拟,计算γ′有序相的成分序参数和长程序参数.结果表明:Ni75Al10V15合金中γ′相的沉淀机制为非经典形核长大,先形成非化学计量比有序相,然后才形成化学计量比有序相,其中非化学计量比有序相并非热力学意义上的亚稳相;DO22结构的非化学计量比θ有序相在γ′相界处形成,其成分和有序化程度较低,且距离相界越远,有序程度越低,θ有序畴存在两种类型:水平分布和垂直分布,和它所依附的γ′相界面取向有关;该模型无须预先设定新相结构和沉淀类型,可在原子水平模拟三元体系的两个有序相析出、成分簇聚等过程.     

丙二酰二异羟肟酸稀土配合物的结构与性质

合成了丙二酰二异羟肟酸及其稀土离子的二元和三元配合物,用元素分析等方法确定其化学式为ＲＥ２（ＭＨＡ）３．ｘＨ２Ｏ,报导了丙二酰二异羟肟酸的离子解常数,利用红外、紫外和荧光等方法研究了两类配合物的结构和性质。     

有序三元系超大集的进一步结果

本文对有序三元系超大集的存在性进行了进一步讨论，得到了ｖ≡１２（ｍｏｄ２４）及ｖ＝３．４＾ｋ．５＾ｎ＋４＾ｋ（ｋ≥０，ｎ≥１），ｖ＝６３．５＾ｎ＋１（ｎ≥０）时，ＯＬＭＴＳ（ｖ）及ＯＬＤＴＳ（ｖ）的存在性。     

Sm（ClO4）3—Ala—H2O三元体系在35℃时的相平衡研究

测定了Ｓｍ（ＣｌＯ４）３－Ａｌａ－Ｈ２Ｏ三元体系在３５℃时的溶解度和饱和溶液２折光率，构制了相应的溶解度图和饱和溶液折光率曲线。溶解度曲线与折光率曲线均由４支组成，分别与Ｓｍ（ＣｌＯ４）３．８Ｈ２Ｏ，Ｓｍ（Ａｌａ）４（ＣｌＯ４）．２Ｈ２Ｏ（Ａ），ｓｍ（Ａｌａ）３（ＣＯ４）３．３Ｈ２Ｏ（Ｂ）和Ａｌａ的晶体相对应。     

LaCl3-BAPOA-H2O体系(30℃)的溶度测定

测定了三元体系ＬａＣｌ３－ＢＡＰＯＡ－Ｈ２Ｏ在３０℃时的溶度及饱和溶液的折光率．发现该体系在３０℃时有一个组成为Ｌａ（ＢＡＰＯＡ）Ｃｌ３的新固相生成,该固相在水中为不一致溶解化合物．     

Gd（NO3）3／Er（NO3）3—Gly—H2O三元体系的研究（25℃）

测定了Ｇｄ（ＮＯ３）３／Ｅｒ（ＮＯ３）３－Ｇｌｙ－Ｈ２Ｏ三元体系在２５℃时的溶度和饱和溶液折光率。各体系的溶度和饱和溶液折光率曲线均由４支组成，分别与ＲＥ（ＮＯ３）３；ｎＨ２Ｏ配合物ＲＥ（Ｇｌｙ）２（ＮＯ３）３．２Ｈ２Ｏ，ＲＥ（Ｇｌｙ）４（ＮＯ３）３；Ｈ２Ｏ及Ｇｌｙ相对应。     

Atomic-scale computer simulation for ternary alloy Ni-Cr-Al during early precipitation process

The aging behaviors of Ni-Cr-Al ternary alloy are studied at temperature 873 K based on the mean-field theory, and the early precipitation process is simulated at atomic-scale with microscopic phase-field model. The precipitation mechanism of the low supersaturated alloy Ni-12.2at.%Cr-7.8at.%Al is non-classical nucleation and growth, the L12 structure (Ni3Al) and D022 structure (Ni3Cr) phases precipitate simultaneously, a part of D022 phase transmits to L12 structure phase, and other part retains its previous structure. For high supersaturated alloy, congruent ordering appears first, then followed by spinodal decomposition, the nonstoicheometric ordered phases are produced in this process, which occurs before clustering. The precipitation mechanism of Ni-8at.%Cr-18at.%Al alloy is similar to Ni-10at.%Cr-12at.%Al alloy, but the ordering process of the former is ahead of the latter.     

1000℃MgO—B2O3—SiO2三元相关系研究

ＭｇＯ－Ｂ２Ｏ３－ＳｉＯ２三元系１０００℃时，３５％≤ＭｇＯ％〈６０％组成范围内平衡相均为固相，其相关系可由Ｍｇ３Ｂ２Ｏ６－Ｍｇ２ＳｉＯ４－Ｍｇ２Ｂ２Ｏ５，Ｍｇ２Ｂ２Ｏ５－Ｍｇ２ＳｉＯ４－ＭｇＳｉＯ３，Ｍｇ２Ｂ２Ｏ５－ＭｇＳｉＯ３－ＳｉＯ２三个结线三角形表示。各平衡相量之间关系可应用ＸＲＤ定量相分析或重心规则计算。     

Ce0.6Zr0.35RE0.05O2（RE=Y，La，Nd，Pr）固溶体的性能研究

采用共沉淀法制备了不同稀土元素改性的Ce0.6Zr0.35RE0.05O2(RE=Y,La,Nd,Pr)固溶体,并用XRD,H2-TPR等方法对其晶相结构、还原性能和高温热稳定性进行研究.结果表明,稀土元素Y,La,Nd,Pr掺入Ce0.6Zr0.4O2固溶体,所形成的三元混合氧化物均为萤石型立方晶相结构的均相固溶体,并未出现所掺杂稀土氧化物的晶相,且高温老化后,物相结构稳定.与Ce0.6Zr0.4O2固溶体比较,稀土元素的掺杂,明显改善了其还原性能及高温热稳定性.     

A thermodynamic model of calculating mass action concentrations for structural units or ion couples in NaClO_4-H_2O and NaF-H_2O binary solutions and NaClO_4-NaF-H_2O ternary solution

A thermodynamic model of calculating mass action concentrations for structural units or ion couples in NaClO4-H2O and NaF-H2O binary solutions and NaClO4-NaF-H2O ternary strong electrolyte aqueous solutions was developed based on the ion and molecule coexistence theory (IMCT). A transformation coefficient was needed to compare the calculated mass action concentration and the reported activity, because they were usually obtained at different standard states and concentration units. The results show that transformation coefficients between the calculated mass action concentrations and the reported activities of the same components change in a very narrow range. The transformed mass action concentrations of structural units or ion couples in NaClO4-H2O and NaF-H2O binary solutions agree well with the reported activities. The transformed mass action concentrations of structural units or ion couples in NaClO4-NaF-H2O ternary solution are also in good agreement with the reported activities in a total ionic strength range from 0.1 to 0.9 mol/kg H2O by the 0.1 mol/kg step with different ionic strength fractions of 0, 0.2, 0.4, 0.5, 0.6, 0.8, and 1, respectively. The results indicate that the developed thermodynamic model can reveal the structural characteristics of binary and ternary strong electrolyte aqueous solutions, and the calculated mass action concentrations of structural units or ion couples also strictly follow the mass action law.     

结构因子的计算及晶格衍射消光规律

从理论上定义几何结构因子.结合定义介绍几种常见晶格几何结构因子的求法,并总结出一种针对复式晶格几何结构因子的更为简单的求法.最后以面心立方为例,对其X射线衍射曲线应用说明,并对该晶格衍射消光规律进行总结.     

Growth characteristics of directionally solidified Al2O3/YAG/ZrO2 ternary hypereutectic in situ composites under ultra-high temperature gradient

Oxide eutectic ceramic in situ composites have attracted significant interest in the application of high-temperature structural materials because of their excellent high-temperature strength,oxidation and creep resistance,as well as outstanding microstructural stability.The directionally solidified ternary Al2O3/YAG/ZrO2 hypereutectic in situ composite was successfully prepared by a laser zone remelting method,aiming to investigate the growth characteristic under ultra-high temperature gradient.The microstructures and phase composition of the as-solidified hypereutectic were characterized by using scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),and X-ray diffraction(XRD).The results show that the composite presents a typical hypereutectic lamellar microstructure consisting of fine Al2O3 and YAG phases,and the enriched ZrO2 phases with smaller sizes are randomly distributed at the Al2O3/YAG interface and in Al2O3 phases.Laser power and scanning rate strongly affect the sample quality and microstructure characteristic.Additionally,coarse colony microstructures were also observed,and their formation and the effect of temperature gradient on the microstructure were discussed.     

Atomic-scale computer simulation for early precipitation process of Ni75Al10V15 alloy

The kinetic model for a ternary system is introduced based on the microscopic diffusion form of the phase-field equations for a binary alloy. The equation is solved in the reciprocal space. This model is used to investigate the early precipitation process of Ni75-Al10V15 by simulating the atomic pictures of the two ordered phases and calculating the order parameters of γ′(Ni3Al) phase. Simulation results show that the γ′ ordered phases precipitate from the disordered matrix by a non-classical nucleation mechanism, and the nonstoichiometric γ′ ordered phase appears first and then transforms into the stoichiometric one. Clusters of V atoms appear at the γ′ phase boundaries followed by the formation of the nonstoichiometric θ ordered phase. The farther the location from γ′ phase boundary is, the lower the order degree of θ phase is. There exist two kinds of DO22 ordered domains: a horizontal one and a vertical one, related to their adjacent γ′ phase boundaries. The model could describe the atomic ordering and composition clustering simultaneously, and any a priori assumption about the new phase structure and precipitation mechanism etc. is unnecessary.     

A thermodynamic model of calculating mass action concentrations for structural units or ion couples in NaClO4-H2O and NaF-H2O binary solutions and NaClO4-NaF-H2O ternary solution

A thermodynamic model of calculating mass action concentrations for structural units or ion couples in NaClO₄-H₂O and NaF-H₂O binary solutions and NaClO₄-NaF-H₂O ternary strong electrolyte aqueous solutions was developed based on the ion and molecule coexistence theory (IMCT). A transformation coefficient was needed to compare the calculated mass action concentration and the reported activity, because they were usually obtained at different standard states and concentration units. The results show that transformation coefficients between the calculated mass action concentrations and the reported activities of the same components change in a very narrow range. The transformed mass action concentrations of structural units or ion couples in NaClO₄-H₂O and NaF-H₂O binary solutions agree well with the reported activities. The transformed mass action concentrations of structural units or ion couples in NaClO₄-NaF-H₂O ternary solution are also in good agreement with the reported activities in a total ionic strength range from 0.1 to 0.9 mol/kg H₂O by the 0.1 mol/kg step with different ionic strength fractions of 0, 0.2, 0.4, 0.5, 0.6, 0.8, and 1, respectively. The results indicate that the developed thermodynamic model can reveal the structural characteristics of binary and ternary strong electrolyte aqueous solutions, and the calculated mass action concentrations of structural units or ion couples also strictly follow the mass action law.     

电渣重熔用CaO-Al_2O_3-SiO_2三元无氟渣系的研究

根据电渣重熔工艺要求和渣相平衡的特点,提出电渣重熔用渣化学组成的设计原则。据此原则,研究了CaO-Al_2O_3-SiO_2,三元系中8个共晶组成和二个同分化合物的性质,测定了其电导率和导热系数。根据其性质和电渣重熔实验,从中选出了两个适于电渣重熔用无氟渣系,其共晶组成(wt％):49.5％CaO-43.7％Al_2O_3-6.8％SiO_2和52.0％CaO-41.2％Al_2O_3-6.8％SiO_2。工业实验表明,其冶金性能与ANF-6渣相当,而电耗可降低30％,从根本上消除了氟化物对环境的污染。     

Anomalous properties in ferroelectrics induced by atomic ordering.

Complex insulating perovskite alloys are of considerable technological interest because of their large dielectric and piezoelectric responses. Examples of such alloys include (Ba1-xSrx)TiO3, which has emerged as a leading candidate dielectric material for the memory-cell capacitors in dynamic random access memories; and Pb(Zr1-xTix)O3 (PZT), which is widely used in transducers and actuators. The rich variety of structural phases that these alloys can exhibit, and the challenge of relating their anomalous properties to the microscopic structure, make them attractive from a fundamental point of view. Theoretical investigations of modifications to the atomic ordering of these alloys suggest the existence of further unexpected structural properties and hold promise for the development of new functional materials with improved electromechanical properties. Here we report ab initio calculations that show that a certain class of atomic rearrangement should lead simultaneously to large electromechanical responses and to unusual structural phases in a given class of perovskite alloys. Our simulations also reveal the microscopic mechanism responsible for these anomalies.