可溶性共聚取代聚醚酰亚胺的H2／CH4和H2／N2的分离性能

本文合成了一系列可溶性共聚取代聚醚酰亚胺（ＨＱＤＥＡ／６ＦＤＡＤＭＭＤＡ），研究了它们的Ｈ２／ＣＨ４和Ｈ２／Ｎ２分离性能。随着６ＦＤＡ含量的增多，伴随着自由体积的增大，透Ｈ２系数呈线性增大，Ｈ２／ＣＨ４和Ｈ２／Ｎ２的分离系数均呈线性减小。当６ＦＤＡ含量占二酐组分的２０ｍｏｌ％和３０ｍｏｌ％时，共聚取代聚醚酰亚胺兼具有高的透Ｈ２性和Ｈ２／ＣＨ４及Ｈ２／Ｎ２选择性，是比较理想的Ｈ２分离与回收的膜材料。     

双醚二酐型聚醚酰亚胺的分子结构与透气性能

合成了一系列单环芳二胺型聚醚酰亚胺，研究了它们对Ｈ２、Ｏ２和Ｎ２３种气体的透过性能。这类双醚二酐（ＨＱＤＥＡ）型聚醚酰亚胺的分子结构对其透气性和透气选择性有很大的影响，随着二胺单体分子中甲基的增多，聚醚酰亚胺的透气性增大，透气选择性减小；由３，５－二氨基苯甲酸合成的ＨＱＥＤＡ－ＤＡＢ具有较高的透Ｈ２系数和很高的Ｈ２／Ｎ２分离系数。     

刚性二酐改性HQDEA—MDA型聚醚酰亚胺的透气性能

合成了一系列刚性二酐改性ＨＱＤＥＡ－ＭＤＡ型聚醚酰亚胺，研究了Ｈ２，Ｏ２和Ｎ２的透过性能与分子结构之间的关系，结果表明，在ＨＱＤＥＡ－ＭＤＡ分子中引入刚性或半刚必的第二种二酐单体后，在透Ｈ２系数有所提高的情况下，聚醚酰亚胺的Ｈ２／Ｎ２选择性明显改善，基中ＢＰＤＡ改性的聚醚酰亚胺ＨＱＤＥＡ／ＢＰＤＡ－ＭＤＡ的透气选择性最好。     

二胺改性BPDA－ODA型聚酰亚胺的H_2／N_2分离性能

本文合成了一系列二胺改性的ＢＰＤＡ－ＯＤＡ型共聚酰亚胺膜，改性聚酰亚胺与未改性的ＢＰＤＡ－ＯＤＡ相比，透气性得到了明显的改善，改善的程度与第二种二胺单体的结构和用量有关。３０℃时，在ＢＰＤＡ－ＯＤＡ中加入２０ｍｏｌ％三甲基间苯二胺（３ＭＰＤＡ）或四甲基对苯二胺（４ＭＰＤＡ）时，共聚酰亚胺ＢＰＤＡ－ＯＤＡ／３ＭＰＤＡ（８０／２０）或ＢＰＤＡ－ＯＤＡ／４ＭＰＤＡ（８０／２０）的透Ｈ２系数和Ｈ２／Ｎ２分离系数分别大于６．５ｂａｒｒｅｒ和１６０，是比较好的气体分离膜材料。     

二胺改性BPDA—ODA型聚酰亚胺的H2／N2分离性能

本文合成了一系列二胺改性的ＢＰＤＡ－ＯＤＡ型共聚酰亚胺膜，改性聚酰亚胺与未改性的ＢＰＤＡ－ＯＤＡ相比，透气性得到了明显的改善，改善的程度与第二种二胺单体的结构和用量有关。３０℃时，在ＢＰＤＡ－ＯＤＡ中加入２０ｍｏｌ％三甲基间苯二胺（３ＭＰＤＡ）或四甲基对苯二胺（４ＭＰＤＡ）时，共聚酰亚胺ＢＰＤＡ－ＯＤＡ／３ＭＰＤＡ（８０／２０）或ＢＰＤＡ－ＯＤＡ／４ＭＰＤＡ（８０／２０）的透Ｈ２系数和Ｈ２／Ｎ２分     

含氨酯键双马来酰亚胺的合成反应和性能研究

本文以糠醇Ｎ－苯基马来酰亚胺，２，４－甲苯二异氰酸酯（２，４－ＴＤＩ），甲苯二异氰酸酯（ＴＤＩ－２０／８０），六次甲基二异氰酸酯（ＨＤＩ）和二苯甲烷双马来酰亚胺（ＢＭＩ）为原料，研究并确定了经由Ｄｉｅｌｓ－Ａｌｄｅｒ反应合成含氨酯键双马一为酰亚胺的合成路线和工艺条件，制备了两种含不同氨酯键结构的新型双马来酰亚胺ＢＭＵ－Ｈ和ＢＭＵ－Ｔ。实验结果表明，采用Ｄｉｅｌｓ－Ａｌｄｅｒ反应合成含氨酸键双马来酸     

HMW—HDPE与LMW—HDPE的共混改性

选用一种高分子量高密度聚乙烯（ＨＭＷ－ＨＤＰＥ）和一种低分子量高密度聚乙烯（ＬＭＷ－ＨＤＰＥ），对它们的共混行为和共混物的热性能、流动性能和力学性能进行了研究。结果表明，在研究的共混比范围内，由ＤＳＣ发现双组分体系可能存在共晶相。ＨＭＷ－ＨＤＰＥ／ＬＭＷ－＝ＨＤＰＥ共混体系的熔体指数基本符合Ａｒｒｈｅｎｉｕｓ粘度加和方程：ＭＩ＝ＭＩ．ＭＩ２。在ＬＭＷ－ＨＤＰＥ质量百分含量为２０％时，共混体系的拉伸     

聚醚砜微孔膜制备中非溶剂添加剂作用研究

以聚醚砜（ＰＥＳ）为膜材料，ＤＭＡｃ为溶剂，研究了３种非溶剂加剂（ＮＳＡ）－ＥｇＯＨ，ＤｅＯＨ和ＢｕＯＨ在水和ＮＳＡ中凝胶对于板微孔膜性能的影响，利用浊点法得到ＰＥＳ／ＤＭＡｃ／ＮＳＡ和ＰＥＳ／ＤＭＣｓ／ＮＳＡ／Ｈ２Ｏ体系２５℃的相图，并以邻近比α值来表征膜溶液组成点靠近相分离的程度，添加了ＮＳＡ的铸膜液在水中凝胶制备微孔膜，以ＥｇＯＨ为非溶剂添加物，在相同聚合物浓度，相同凝胶条件下，仅仅改变铸膜     

1－十二酰胺基－1－甲基乙膦酸钠及其微乳液的缓蚀作用

用静态失重法、稳态极化曲线和扫描电镜初步研究了ＤＡＭＥＰＮａ＿２－及ＤＡＭＥＰＮａ＿２－庚烷－戊醇－自来水微乳液对２０￣＃碳钢的缓蚀性能，结果表明（１）两者都为抑制阳极为主的混合型缓蚀剂，（２）该微乳液具有较好的缓蚀性能，缓蚀率可达９９％以上，而单一ＤＡＭＥＰＮａ＿２－的缓蚀率仅为１６．２％。     

HDPE／顺丁橡胶共混材料磨蚀速率的研究

用自制的旋臂式磨蚀实验仪，研究了高密度聚乙烯（ＨＤＰＥ）／顺丁橡胶、高密度聚乙烯和４５＾＃钢在攀枝花尾矿矿浆中的磨蚀速率与磨蚀温度和磨蚀时间的关系。结果表明，在２０－４８℃时，Ｗ（ＨＤＰＥ／ｃｉｓ－ＢＲ）和Ｗ（ＨＤＰＥ）分别保持在０．１７－０．２０ｍｍ／ａ和０．２２－０．３０ｍｍ／ａ。在５５℃时，Ｗ（ＨＤＰＥ／ｃｉｓ－ＢＲ和Ｗ（ＨＤＰＥ）分别增加至０．２８和０．３９ｍｍ／ａ，在２０－５５℃时，Ｗ（     

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.     

Thermoelectric power of single-phase samples of Tl2CaBa2Cu2O y and Ba2CaSr2Cu2O y

Single-phase 2122 samples of thallium and bismuth superconductors were made by the precursor matrix method. The thermopower of these samples was measured in the temperature range 250 K-T _c . The thermopower was positive and decreased linearly with increasing temperature aboveT _c (onset). The exponential enhancement of thermopower seen in the undoped and doped YBCO was not observed in these samples. The linear variation of thermopower can be explained on the basis of either a two-band model or a narrow band model.     

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.     

SiO2—TiO2—ZrO2系涂层的制备及其特性

用溶胶－凝胶法（sol-gel method）在不锈钢表面制备了SiO2-TiO2-ZrO2系无机氧化膜（STZ）。用DTA／TG、IR、XRD和SEM等手段研究了涂层制备时由凝胶向玻璃态的转变以及涂层薄膜的显微结构特点，考察了涂层对基体的保护效果。试验结果表明，在溶胶至凝胶最终转变为无机氧化物的过程中形成了无机网络，Si^4 和Zr^4 充当了网络骨架的形成离子。涂层为无定型玻璃态，其间混有石英、锐钛矿或金红石等微晶。     

Structure of Na2O·2TiO2 glass

X-ray radial distribution analysis and Raman spectroscopic measurement were carried out on Na₂O-2TiO₂ glass prepared by twin-roller quenching method. It is found that four-coordinated Ti⁴⁺ ions may be predominant over six-coordinated ones in the present glass. It is also found that the fraction of six-coordinated Ti⁴⁺ ions is larger in the present glass than in K₂O·2TiO₂ and Cs₂O·2TiO₂ glasses. Poorer glass-forming ability of the Na₂O-TiO₂ system compared with the K₂O-TiO₂ and Cs₂O-TiO₂ systems is ascribed to a larger fraction of TiO₆ octahedron for the former system.     

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.     

掺杂Bi_2Ti_2O_7对Y_2O_3-2TiO_2系微波介质陶瓷材料性能的影响

目前国内外对εr范围在40～80左右的中介电常数微波介质陶瓷体系的研究还很缺乏。为适应现代微波通讯技术发展需求,本实验研究开发了新型中介电常数Y2O3-2TiO2系微波介质陶瓷,并在此基础上添加Bi2Ti2O7陶瓷粉料进行复相掺杂。利用网络分析仪,阻抗分析仪,XRD,SEM等方法,本文重点研究了不同Bi2Ti2O7掺杂量对Y2O3-2TiO2系微波介质陶瓷材料烧结性能和介电性能的影响。通过分析发现适量掺杂能够有效降低材料的烧结温度,并使材料致密化。同时由于Bi3+置换主晶相中的Y3+形成了固溶体,材料主晶相为烧绿石结构并未改变。当添加质量分数为8wt%时获得介电性能较好的陶瓷材料,烧结温度从未掺杂的1460℃降低到1320℃。在1M下:εr≈62.14,tanδ≈1.22×10-3,微波频率(4.55GHz)下εr≈62.85,Q.f=4122.8GHz,τf=-7ppm/℃。     

Spectroscopic investigations of Cu2+ in Li2O-Na2O-B2O3-Bi2O3 glasses

Pure and copper doped glasses with composition,x Li ₂ O-(40-x)Na ₂ O-50B ₂ O ₃-10Bi ₂ O ₃,have been prepared over the range 0 ≤ x ≤ 40. The electron paramagnetic resonance (EPR) spectra of Cu²⁺ ions of these glasses have been recorded in the X-band at room temperature. Spin Hamiltonian parameters have been calculated. The molecular bonding coefficients, α² and β², have been calculated by recording the optical absorption spectra in the wavelength range 200–1200 nm. It has been observed that the site symmetry around Cu²⁺ ions is tetragonally distorted octahedral. The density and glass transition temperature variation with alkali content shows non-linear behaviour. The IR studies show that the glassy system contains BO₃ and BO₄ units in the disordered manner.