共聚物电解质MA—Na2／AA—Na水溶液的粘度特性

对共聚物电解质ＭＡ－Ｎａ２（顺丁烯二酸钠）／ＡＡ－Ｎａ（丙烯酸钠）水溶液ηｓｐ／Ｃ（比浓粘度）与浓度的关系、中性盐及溶液ｐＨ对ηｓｐ／Ｃ的影响进行了研究。结果表明，稀释ＭＡ－Ｎａ２／ＡＡ－Ｎａ溶液时，ηｓｐ／Ｃ急剧上升，而稀释含中性盐（ＫＣｌ或ＣａＣｌ２）的ＭＡ－Ｎａ２／ＡＡ－Ｎａ溶液体系时（中性盐含量保持０．０１ｍｏｌ／Ｌ），ηｓｐ／Ｃ的变化却不大。添加极少量（〈０．０５％）中性盐，可使ＭＡ－Ｎ     

AMT保护青铜的研究

采用电化学方法和ＸＰＳ、ＡＥＳ法研究５－氨基－２－巯基－１、３、４－噻二唑（ＡＭＴ）在青铜表面形成的保护膜。结果表明，ＡＭＴ溶液处理后的青铜试片在ｐＨ值为７的０．５ｍｏｌ／ＬＮａ２ＳＯ４和５％ＮａＣｌ溶液中，其腐蚀过程受到了明显抑制，是由于ＡＭＴ在青铜表面形成Ｃｕ（Ｉ）ＡＭＴ络合物膜，其结构为Ｃｕ｜Ｃｕ２Ｏ｜Ｃｕ（Ｉ）ＡＭＴ。     

La、RE对Al－Mg－Si合金耐蚀性能的影响

研究了稀土元素Ｌａ和混合稀土对Ａｌ－Ｍｇ－Ｓｉ合金耐蚀性能的影响，测定了合金在３．５％（ｗｔ）ＮａＣｌ溶液和５．０％（ｗｔ）ＨＣｌ溶液中的电化学阻抗谱，并用ＸＰＳ对合金表面的成分进行了分析。结果表明，稀土元素的加入改变了钝化膜的成分，使合金的显微组织更加均匀，从而提高了合金的耐蚀性。     

RS高强Al－Zn－Mg－Cu系合金热处理温度与性能的关系

本文系统研究了ＲＳ高强Ａｌ－Ｚｎ－Ｍｇ－Ｃｕ系合金淬火温度、时效温度与性能关系，同时还分析了合金的微观组织。试验得出在４７０℃淬火峰时效（Ｔ６）的拉伸性能达到σ_ｂ＝７４０ＭＰａ，σ_（０．２）＝７０２ＭＰａ，δ_５＝１０％；双级时（Ｔ７３）可获得σ_ｂ＝６３３ＭＰａ，σ_（０．２）＝６０６ＭＰａ，δ_５＝１１．５％。合金的弥散强化相是Ｃｏ_２Ｎ_９、Ａｌ_３Ｚｒ，沉淀强化相为ＧＰ区、η＇和η。     

RS高强Al－Zn－Mg－Cu系合金热处理温度与性能的关系EI

本文系统研究了ＲＳ高强Ａｌ－Ｚｎ－Ｍｇ－Ｃｕ系合金淬火温度、时效温度与性能关系，同时还分析了合金的微观组织。试验得出在４７０℃淬火峰时效（Ｔ６）的拉伸性能达到σ_ｂ＝７４０ＭＰａ，σ_（０．２）＝７０２ＭＰａ，δ_５＝１０％；双级时（Ｔ７３）可获得σ_ｂ＝６３３ＭＰａ，σ_（０．２）＝６０６ＭＰａ，δ_５＝１１．５％。合金的弥散强化相是Ｃｏ_２Ｎ_９、Ａｌ_３Ｚｒ，沉淀强化相为ＧＰ区、η＇和η。     

1,3-戊二烯阳离子聚合引发体系(CH3)3SiCl/EtAlCl2的研究

研究了阳离子引发体系Ｍｅ３ＳｉＣｌ（ＴＭＳＣｌ）ＥｔＡｌＣＬ２在正己烷中引发的１,３－戊二烯（ＰＤ）聚合反应。研究结果表明,在ＥｔＡｌＣｌ２引发的ＰＤ聚合反应中引入ＴＭＳＣｌ后大幅主提高了聚合物产率,同时使聚合反应速率明显提高,在「ＴＭＳＣｌ」／「ＥｔＡｌＣｌ２２」＝０－１范围内,ＴＭＳＣｌ／ＥｔＡｌＣｌ２体系制备的聚合物分子量高于ＥｔＡｌＣｌ２引发制备的聚合物,这些结果表明Ｍｅ３ＳｉＣｌ／ＥｔＡ     

添加Al_2O_3对SiC板粒／Y－TZP复合材料力学性能的影响

本文以ＳｉＣ板粒、ＺｒＯＣｌ２－８Ｈ２Ｏ、ＡｌＣｌ３和Ｙ（ＭＯ）３为原料，利用共沉淀和热压烧结工艺，制备ＳｉＣ板粒／Ｙ－ＴＺＰ和（含Ａｌ２Ｏ３）ＳｉＣ板粒／Ｙ－ＴＺＰ复合材料．测试了材料的室温和高温力学性能．研究了添加Ａｌ２Ｏ３对ＳｉＣ板粒／Ｙ－ＴＺＯ复合材料的影响．结果表明，ＳｉＣ板粒／Ｙ－ＴＺＰ复合材料与Ｙ－ＴＺＰ陶瓷相比，其室温强度和韧性出现明显下降，高温强度也没有改善；而在ＳｉＣ板粒与Ｙ－ＴＺＰ复合的基础上，添加Ａｌ２Ｏ３可明显提高材料的强度和断裂韧性，同时，材料的高温强度也获得显著改善．     

α-蒎烯/苯乙烯共聚反应调控研究--催化体系和反应条件对共聚活性的影响

研究了两类阳离子聚合催化体系即ＳｂＣｌ３／ＡｌＣｌ３复合体系和高分子负载体系ＰＳ－１８８－ＳｂＣｌ３／ＡｌＣｌ３,交联ＰＳ－ＳｂＣｌ３／ＡｌＣｌ３对α－蒎烯（Ｍ１）／苯乙烯（Ｍ２）的共聚反应性能。测定了竞聚率,考察了反应条件、催化剂组分特别是ＰＳ－１８８－ＳｂＣｌ３、交联ＰＳ－１８８－ＳｂＣｌ３组分等对竞聚率的影响。结果表明,该两类催化体系对Ｍ１／Ｍ２均具有良好的共聚合性能,ｒ２和ｒ２／ｒ１大幅度降低;并可通过温度、组分比进行调控;特别是高分子负载催化体系,不但共聚活性比Ｓｂ－Ｃｌ３／ＡｌＣｌ３更高,ｒ１特别是ｒ２大幅度降低,而且共聚反应可在０～２０℃的高温下进行,共聚产物分子量大幅度提高,分布变窄。     

La,RE对Al—Mg—Si合金耐蚀性能的影响

研究了稀土元素Ｌａ和混合稀土对Ａｌ－Ｍｇ－Ｓｉ合金耐耐蚀性能的影响，测定了合金在３．０％（ｗｔ）ＮａＣｌ溶液和５．０％（ｗｔ）Ｈｃｌ溶液中的电化学阻抗谱，并用ＸＰＳ对合金表面的成分进行了分析。结果表明，稀土元素的加入改变了钝化膜的成分，使合金的显微组织更加均匀，从而提高了合金的耐蚀性。     

超负磁致伸缩晶体Sm－Fe、Sm－Dy－Fe和Sm－Dy－Fe－Al的研究

本文研究了轻稀土负磁致伸缩ＳｍＦｅ＿ｘ（１．４０＜ｘ＜１．９４），Ｓｍ＿ｘＤｙ＿（１－ｘ）Ｆｅ＿ｙ（０．８４＜ｘ＜０．９２．１．８０＜ｙ＜１．９０），Ｓｍ＿（０．９０）Ｄｙ＿（０．１０）（Ｆｅ＿（０．９５）Ａｌ＿（０．０５））＿（１．８０）晶体的制备、热处理及磁学性能，发现ＳｍＦｅ＿ｘ合金的λ－ｘ曲线存在两个峰值，峰值的ｘ点随热处理发生的变化有一定的规律性，还比较了热处理前后，Ｓｍ－Ｆｅ、Ｓｍ－Ｄｙ－Ｆｅ和Ｓｍ－Ｄｙ－Ｆｅ－Ａｌ的相组成对性能的影响。热处理用于改善磁致伸缩性能，并且制得了高磁致伸缩性能的ＳｍＦｅ＿２和（Ｓｍ，Ｄｙ）Ｆｅ＿２合金。     

Elastic properties and lattice dynamics of alkali chalcogenide compounds Na2S,Na2Se and Na2Te

We report on first principles study of the elastic, vibrational and dielectric properties of the alkali chalcogenide compounds Na₂S, Na₂Se and Na₂Te using the pseudopotential method within the local density approximation and linear response theory. The calculated lattice constants for the studied compounds are in good agreement with available experimental data as well as with other theoretical results. The phonon dispersion curves and phonon density of states are calculated by using density functional perturbation theory. For Na₂S the experimental features of lattice dynamics data are well reproduced by our calculations. The width of the acoustic frequency range decreases with increasing chalcogen atomic number. The phonon densities of states show that Na⁺ ions are involved in the lower frequency modes in Na₂S. However, the inverse occurs in the case of Na₂Se and Na₂Te. The mean-square ionic displacements show that Na⁺ ions perform large thermal vibrations even at temperatures well below the melting point. The Born effective charge increases, while the IR oscillator strength decreases with anion atomic number.     

High Na+-ion conductivity in Na5YSi4O12

Ceramic specimens of Na₅YSi₄O₁₂ with densities up to 95% of theoretical and Na⁺-ion conductivities at 300°C up to 0.15 Ω^?1 cm^?1 have been fabricated from powders synthesized by solid-state reaction of Na₂C₂O₄, Y₂(C₂O₄)₃, and SiO₂. Conductivity values obtained by complex impedance measurements on one specimen between 25 and 320°C gave an activation energy of 0.15 eV above 175°C, but the ln (σ T) versus 1/T plot was not linear at the lower temperatures.     

Na(Y1.5 Na0.5)F6 single-crystal nanorods as multicolor luminescent materials

A facile wet chemical synthesis method was used to prepare a range of single-crystal Na(Y1.5 Na0.5)F6 nanorods with controllable aspect ratios. Their novel multicolor upconversion (UC) fluorescence has been successfully realized by doping Yb3+/Er3+ (green) and Yb3+/Tm3+ (blue) ion pairs. When doped with Eu3+ and Tb3+ ions, the strong red and green downconversion (DC) fluorescence has also been observed, respectively. Being covered with oleic acids, these luminescent nanorods have been transparently dispersed in nonpolar solvent. For their unique luminescence and controllable morphology and surface properties, these nanorods may find great applications in the fields of color displays, biolabels, light-emitting diodes (LEDs), optical storage, optoelectronics, anticounterfeiting, and solid-state lasers.     

Large enhancement of the thermopower in Na(x)CoO2 at high Na doping

Research on the oxide perovskites has uncovered electronic properties that are strikingly enhanced compared with those in conventional metals. Examples are the high critical temperatures of the cuprate superconductors and the colossal magnetoresistance in the manganites. The conducting layered cobaltate Na(x)CoO2 exhibits several interesting electronic phases as the Na content x is varied, including water-induced superconductivity and an insulating state that is destroyed by field. Initial measurements showed that, in the as-grown composition, Na(x)CoO2 has moderately large thermopower S and conductivity sigma. However, the prospects for thermoelectric cooling applications faded when the figure of merit Z was found to be small at this composition (0.60.75, S undergoes an even steeper enhancement. At the critical doping x(p) approximately 0.85, Z (at 80 K) reaches values approximately 40 times larger than in the as-grown crystals. We discuss prospects for low-temperature thermoelectric applications.     

Na43+ clusters in sodalite

Anion-sodalites with the general formula Na₈[(AlO₂)₆(SiO₂)₆]A₂, where A = Cl, Br or I, were reacted with the vapour of alkali metals. In all cases the ionic cluster Na₄³⁺ was formed, together with a metallic cluster. The ionic cluster was investigated by electron spin resonance, electron spin echo and pulse-electron nuclear double resonance techniques. A modulation was observed in the electron spin echo envelope due to interaction with distant Na⁺ ions. These Na⁺ ions have hyperfine splitting constants between 0.24 and 1 MHz and are situated ∼ 5 Å from the centre of the sodium cluster.     

Stabilizing Na3SbS4/Na interface by rational design via Cl doping and aqueous processing

Solution-synthesis method is attractive for solid electrolytes because it is a facile and scalable process to be used to permeate electrodes and to construct a thin electrolyte coating layer on active materials.In this work,we report Cl-doped Na3SbS4 prepared via aqueous-solution approach.Besides decent ionic conductivity,the aqueous-solution approached electrolyte demonstrates an improved interfacial stability toward Na metal compared to the solid-state sintered one because of the residual hydrate,nanosized microstructure,and Cl incorporation.All-solid-state batteries using the solution-prepared electrolytes have enhanced cycling performance,though the performance still needs to be further improved.     

Na2O-CaO-SiO2 glass-ceramic matrix biocomposites

Na₂O-CaO-SiO₂ glass- and glass-ceramic matrix/Ti particle biocomposites have been prepared by means of two processes: pressureless sintering and hot pressing. Time and temperature sintering conditions were optimised on the basis of the thermal properties of mixed glass and Ti powders, determined by Differential Thermal Analysis, Differential Scanning Calorimetry, Hot Stage Microscopy, Dilatometry. Each sintered sample was characterised by means of X-ray diffraction, Scanning Electron Microscopy, EDS, density measurements, Young's modulus, induced crack propagation by Vickers indentations, three point bending test, K _IC measurements. The in vitro bioactivity was investigated on the sintered composites by soaking them in a simulated body fluid (SBF) with the same ion concentration of the human plasma.     

Influence of Na deposition on convoy-electron emission

The influence of surface properties on convoy-electron emission from a sputter-clean Al foil induced by H⁺ has been studied under ultrahigh-vacuum conditions. It is found that the convoy-electron yield depends strongly on the Na coverage when the downstream surface is modified by controlled Na deposition. It can be concluded that an increasing yield is observed for larger work-function values.