8mol％CeO_2－ZrO_2中的贝氏体相变

测定８ｍｏｌ％ＣｅＯ２－ＺｒＯ２在连续冷却中变温ｔ→ｍ的Ｍｓ，在Ｍｓ以上及以下的等温相变动力学曲线和相变产物的点阵常数等．温相变产物（贝氏体）的点阵常数小于变温马氏体的点阵常数．参照金属材料中的贝氏体相变，建议８ｍｏｌ％ＣｅＯ２—ＺｒＯ２的等温相变为扩散过程控制的贝氏体相变．贝氏体可能在母相晶界形核．     

陶瓷中的相变

提出陶瓷中相变的分类，引述ｓｐｉｎｏｄｅｌ分解的热力学判据和动力学判据，评述含ＺｒＯ２陶瓷马氏体相变尺寸效应的热力学推导和象理论在ＭｇＯ－ＰＳＺ，ＣｅＯ２－ＴＺＰ，Ｙ２Ｏ３－ＴＺＰ，ＢａＴｉＯ３；ＫＴＮ，ＰｂＴｉＯ３及ＹＢａ２Ｃｕ３Ｏ７－ｘ马氏体相变中的应用，指出含ＺｒＯ２陶瓷及ＹＢａ２Ｃｕ３Ｏｙ的等温相变可能属扩散机制的贝氏体相变。     

氧化锆陶瓷的可逆相变及铁弹性畴转变

本文通过对成分（ｍｏｌ％）为８ＣｅＯ２－１Ｙ２Ｏ３－９１ＺｒＯ２陶瓷材料Ｃｅ－Ｙ－ＴＺＰ的应力应变关系的研究，配合Ｘ身线衍射分析，发现材料中ｔ＾→←ｍ的可逆相变及不可逆铁弹性畴转变。在此基础上提出了Ｃｅ－Ｙ－ＴＺＰ陶瓷材料的增韧公式。     

2Y2O3—ZrO2陶瓷中t→m相变

用热膨胀分析仪和Ｘ射线衍射仪研究了２＾（ｍｏｌ百分数，下同）Ｙ２Ｏ３－ＺｒＯ２陶瓷中ｔ→ｍ等温和变温相变动力学及相结构。发现其中存在的低温和中温ｔ→ｍ相变。前者发生在液氮温度附近或更低温度，具有爆发性转变特征，不能被快速冷却抑制。后者发生在室温以上，具有等温相变特征。相变过程中仅与温度有关，而且受时间控制，ＴＴＴ曲线具有Ｃ形特征。相变温度范围取决于ｔ相晶粒尺寸和冷速，足够快的冷速可抑制中温相变。Ｘ     

粒径与掺杂对ZrO2纳米粉相结构的影响

用Ｘ射线衍射仪和透射电镜研究了粒径和Ｙ，Ｃｅ掺杂元素对ＺｒＯｗ纳米粉相结构的影响。结果表明，在室温下平均粒径为￣１０ｎｍ的ＺｒＯ２粉单斜相不足２０ｖ．％，而加入２ｍｏｌ％Ｙ２Ｏ３或２ｍｏｌ％ＣｅＯ２可使单斜相更少，试验测得纯ＺｒＯ２，ＺｒＯ２－２ｍｏｌ％ＣｅＯ２，ＺｒＯ２－２ｍｏｌ％Ｙ２Ｏ３纳米粉在室温下单斜相和四方相保持平衡共存的临界粒径分别为１７．５，２１．０和３２．５ｎｍ。     

2Y2O3—xCeO2对ZTM复相陶瓷相组成,显微结构,力学性能的影响

采用原位反应烧结工艺制备了ＺｒＯ２增韧莫来石（ＺＴＭ）复相陶瓷。研究和分析了在Ｙ２Ｏ３为２ｆｍｏｌ％的情况下，ＣｅＯ２添加量（用２Ｙ２Ｏ３－ｘＣｅＯ２）对ＺＴＭ复相陶瓷相组成，显微结构及力学性能的影响，结果表明，当ＣｅＯ２添加量（用２Ｙ２Ｏ３－ｘＣｅＯ２）对ＺＴＭ复相陶瓷相组成、显微结构及力学性能的影响。结果表明，当ＣｅＯ２添加量在１．５～４．５ｍｏｌ％时，ＺｒＯ２晶格畸变，晶胞长大，缺陷增加，Ｃ     

ZrO2—30mol?O2陶瓷粉末的高能球磨过程

本文研究了ＺｒＯ２－３０ｍｏｌ％ＣｅＯ２陶瓷粉末的高能球磨过程，首先发现陶瓷材料在高能球磨过程中，有机械合金化（ＭＡ）发生。     

ZrO_2－30mol％CeO_2陶瓷粉末的高能球磨过程

本文研究了ＺｒＯ２－３０ｍｏｌ％ＣｅＯ２陶瓷粉末的高能球磨过程，首先发现陶瓷材料在高能球磨过程中，有机械合金化（ＭＡ）发生．     

三元系ZrO3固溶体的XPS和XRD研究

对ＣｅＯ２－ＭｇＯ－ＺｒＯ２系固溶体的ＸＰＳ和ＸＲＤ研究结果表明：在１７００℃烧结和随后的１２００℃处理过程中。Ｃｅ＾４＋被还原成Ｃ＾３＋，离子半径的差别使立方相的晶格常数增大，氧的的结合能增大，镁的结合能减小，热处理时，Ｃｅ离子在ＭｇＯ偏析后仍稳定存在于ＺｒＯ２晶格中，使立方ＺｒＯ２发生与会传统Ｍｇ－ＰＳＺ不同的分解反应：ｃ－ＺｒＯ２→ｃ′－ＺｒＯ２＋ｔ－ＺｒＯ２＋ＭｇＯ。     

ZrO2的加入对(CeO2)0.86(SmO1.5)0.14陶瓷性能的影响

探讨了添加ＺｒＯ２和ＣｅＯ２／Ｓｍ２Ｏ３体系电导率和力学性能的影响,并用ＸＲＤ、ＳＥＭ等对材料的微观性能进行了试验分析,结果发现,添加ＺｒＯ２使材料的电导率降低,主要是因为ＺｒＯ２的固溶使得ＣｅＯ２电解质材料的晶格常数减小,活化能增加造成的;添加ＺｒＯ２可提加ＺｒＯ２促进了致密烧结,使晶界结合紧密。实验确定,外加２．５ｍｏｌ％ＺｒＯ２的ＣｅＯ２电解质具有适中的强度和电导率,可以作为电解质材料应用。     

VLE data for CO2-CF2Cl2, N2-CO2, N2-CF2Cl2 and N2-CO2-CF2Cl

Knowledge about vapour-liquid (VLE) is required as a basis of reliable calculations for separation processes. Correlations available for the prediction of T, p, x, y data are less accurate for mixtures at high pressures and mixtures containing supercritical components. The results of VLE experiments are reported and compared with data calculated with equations of state.     

Thermal diffusion in binary mixtures H2-CCl2F2 and H2-CHClF2

Thermal diffusion coefficients were measured in two gaseous mixtures, in which one component was close to the critical temperature, in the pressure range (19.6–127.4)·10⁴ N/m² and at a freon concentration of 0.25–0.8.     

Preparation of ZrO2-CeO2 and HfO2-CeO2 nanopowders

We prepared weakly agglomerated powders of ZrO₂-CeO₂ and HfO₂-CeO₂ solid solutions 5–8 nm in particle size, consisting of monoclinic and tetragonal phases. After heat treatment at 1200°C, the crystallite size was 30 and 14 nm, respectively. We also examined the effect of precipitate freeze drying on the crystallization of hafnia-based solid solutions containing up to 20 mol % CeO₂.     

Comparison of the Electronic Structures of La2CuO4, Sr2CuO2Cl2, and Sr2CuO2F2

First-principles cluster calculations are reported of the local electronic structure of the three compounds: La₂CuO₄, Sr₂CuO₂Cl₂, and Sr₂CuO₂F₂. The copper ${\text{3d}}_{x^2 - y^2 } $ and the planar oxygen 2p _σ atomic orbitals exhibit a similar degree of covalency. The out-of-plane orbitals, however, are quite different with the ${\text{3}}d_{3z^2 - r^2 } $ atomic orbital lowered significantly in energy for chlorine and fluorine apical positions.     

Radial GRIN glasses in Li2O-Na2O-Al2O3-TiO2-SiO2 systems

A series of GRIN glass rods have been developed in Li2O-Na2O-Al2O3-TiO2-SiO2 systems. Negative radial refractive index profiles were generated by exchanging Na+ for Li+ ions in these glass rods. It has been observed that TiO2 plays a vital role in increase in the profile depth and maximum change in the refractive index because of its ambivalent nature. Change in the refractive index can be further increased by increasing the concentration of exchanging cation in the base glass.     

Elastic and Electronic Properties of Superconducting CaPd 2 As 2 and SrPd 2 As 2 vs. Non-superconducting BaPd 2 As 2

The first-principles calculations were performed to predict the elastic and electronic properties of the superconducting ThCr₂Si₂-type phases CaPd₂As₂ and SrPd₂As₂ in comparison with the non-superconducting CeMg₂Si₂-type phase BaPd₂As₂. Besides, the same properties were compared for CeMg₂Si₂- and ThCr₂Si₂-type polymorphs of BaPd₂As₂. We found that all these phases are mechanically stable and belong to soft materials with low hardness. The near-Fermi region is formed by the valence states of the blocks [Pd₂As₂] with decisive contributions of Pd 4d states. The values of N(E _F) increase in the sequence: CaPd₂As₂ < SrPd₂As₂ < BaPd₂As₂, i.e. in the reverse sequence relative to the transition temperatures T _C. Thus, the change in T _C cannot be explained by the electronic factor, i.e. by the simple correlation T _C～N(E _F). Most likely the decrease in T _C in the sequence CaPd₂As₂ → SrPd₂As₂ and the absence of a superconducting transition in BaPd₂As₂ are related to the structural factors and the peculiarities of the electron–phonon coupling mechanism.     

Si_2N_2O-Al_2O_3-La_2O_3和Si_2N_2O-Al_2O_3-CaO系统的亚固相关系

本文给出了 Si_2N_2O-Al_2O_3-La_2O_3和 Si_2N_2O-Al_2O_3-CaO 系统的亚固相图。实验结果表明:在 Si_2N_2O-Al_2O_3-CaO 系统中有一个未知结构的新化合物 CaO·Si_2N_2O,在3CaO·Si_2N_2O 和3CaO·Al_2O_3两化合物之间形成连续立方固溶体。而 Si_2N_2O-Al_2O_3-La_2O_3系统中则没有发现新化合物。在两个系统的富 Si_2N_2O区,过量的 Si_2N_2O 与 La_2O_3和 CaO 分别反应形成 Si_3N_4与 La_(10)[SiO_4]_(?)N_2(H-相)(和 CaSiO_3。所研究的这两个三元系统中,分别形成了如下几个四元相容性区。在 Si_2N_2O-Al_2O_3-La_2O_3系统内有:H-Si_3N_4-La_2O_3·Si_2N_2O-La_2O_3·Al_2O_3;H-Si_3N_4-La_2O_3·Al_2O_3-La_2O_3·11 Al_2O_3;H-Si_3N_4-La_2O_3·11 Al_2O_3-Al_2O_3;H-Si_3N_4-Al_2O_3-O′s.s;H-Si_3N_4-O′s.s-Si_2N_2O在 Si_2N_2O-Al_2O_3-CaO 系统内有:Si_3N_4-CaSiO_3-CaO·Si_2N_2O-3CaO·Al_2O_3;Si_3N_3-CaSiO_3-3CaO·Al_2O_3-2CaO·Al_2O_3·SiO_(?);Si_(?)N_(?)-CaSiO_3-2CaO·Al_2O_3·SiO_2-Al_2O_3;Si_3N_4-CaSiO_3-Al_2O_(?)-O′s.s;Si_3N_4-CaSiO_3-O′s.s-Si_(?)N_(?)O