Impact of Yb3+/Er3+ions on crystallization of phosphosilicate glass melts

Transparent glass ceramics were prepared from the phosphosilicate system by melt-quenching devitrification(MQD) method, i.e., nanocrystals spontaneously form during cooling of the melts. Introduction of 2.5 wt.% Yb2O3 and 0.5 wt.% Er2O3 into the glass melt induced the change of type and concentration of crystals. The comparison of rheological and thermodynamic properties of both undoped and Yb3+/Er3+ doped melts showed that addition of Yb3+/Er3+ oxides caused increase of liquid fragility, and degree of medium-range order. In addition, the thermodynamic barriers for nucleation ΔG* as a function of reduced temperature T/Tm were calculated with an assumption of wetting angle θ=90o, Yb3+/Er3+ doped melt tended to firstly nucleate as compared to undoped melt at small undercooling.     

在教指委指导下,积极开展专业建设活动

自2003年在教育部高等学校电子科学与技术专业教学指导分委员会的指导下,认真研究和制订了专业发展规划。从2003年开始,在原有的电子材料与元器件方向上先后发展了光电子方向和微电子方向,2007年成立了独立招生的微电子本科专业。并建立健全本科各方面专业实验室和实践基地,在专业建设和人才培养方面取得了较大的进步。     

氢键分子链中扭结—反扭结孤子的非对称特性

采用微扰方法研究了氢键分子链中原子间存在非简谐相互作用时，对扭结-反扭结孤子的影响，得到了3次方到6次方非简谐项下的扭结-反扭结孤子的非对称解，计算了由非简谐项引起的扭结-反扭结孤子的能量和有效质量．     

新型光刻技术的现状与进展

大尺寸、细线宽、高精度、高效率、低成本成为IC产品发展的趋势,随着集成度的提高,芯片制造中最关键的制造工艺--光刻技术也面临着愈来愈多的难题.新兴的193 nm浸入式技术、157 nm极短紫外光刻(Euv)、电子束投影光刻(EPL)、纳米压印光刻等技术将是解决这些问题的关键.介绍了193nm浸入式技术、157nm光刻技术、电子束投影(EPL)光刻技术以及纳米压印光刻技术.指出纳米压印光刻技术具有生产效率高、成本低、工艺过程简单等优点,能实现分辨率达5 nm以下的水平,是最具发展前途的下一代光刻技术之一.     

固相法制备BaTiO3基细晶陶瓷粉体

通过传统的固相法制备BaTiO3基细晶陶瓷粉体，讨论了在预烧温度和烧结温度相同的情况下，探讨不同施主元素的添加量对陶瓷晶粒及电性能的影响；在预烧温度和烧结温度相同的情况下，探讨不同受主杂质对陶瓷晶粒及电性能的影响；在施、受主掺杂量及烧结温度相同的情况下，探讨不同的预烧温度对陶瓷晶粒及电性能的影响．为了制备高升阻比、晶粒细小的BaTi03陶瓷，选取的材料配方为Ba1.0Ti1.01O3＋0.4％（摩尔分数）Y2O3＋0.03％（摩尔分数）Mn（NO3）2＋2％S102，粉体在1200℃预烧，保温2h，样品在1280℃烧成。上电极后测得常温电阻率为4937Ω·cm，升阻比为7．116×10^3，温度系数为14．03％，居里温度为128．4℃．     

校企联合，完善工科专业的实践教学体系

针对本科生的实践能力、创新能力和就业实践竞争力不足等工科教学改革面临的主要问题,本文研究了强化校企合作;利用硕士生的实践过程带动本科生的实践;在企业实现工科专业毕业实习-毕业设计-就业的产学合作教育实践教学模式。探索了以企业实践活动为中心,带动课程改革及用创新基金带动学生实践活动的实践模式。     

四量子比特Heisenberg XX开链中的成对纠缠

研究外加磁场作用下的四量子比特Heisenberg XX开链中的成对纠缠,得到了纠缠度量Concurrence的解析表达．研究发现在外加均匀磁场系统中边界比特间的纠缠值可达到0．28．此外,在外加磁场作用在边界比特上的Heisenberg XX模型中,低温时通过增大磁场强度可以使两个非边界比特处于最大纠缠．     

掺锆SnO_2陶瓷的乙醇气敏特性研究

在研究SnO_2乙醇气体敏感陶瓷中,比较添加物,发现ZrO_2对乙醇气体有较高的灵敏度。进而从工艺上研究了添加ZrO_2时的最佳烧结温度和预烧温度。分析了烧结温度与测试初始电阻的关系。总结出不同条件下乙醇的分解物不同。提出ZrO_2的催化机理是活化表面羟基,释放占有的电子,释放表面的吸附位,从而提高氧离子的效率。     

铌掺杂Ba（ZrxTi1-x）O3弛豫铁电陶瓷介电性质的研究

采用传统的固相反应法制备了Ba（Zr0.25Ti0.75）03＋xat％Nb2O5（x=0，0．05，0．1，0．15）弛豫铁电陶瓷，研究了Nb2O5加入量对Ba（Zr，Ti）03（BZT）基电容器陶瓷性能的影响，得到了Nb2O5影响其性能的规律。结果表明：当x=0．15时介电常数最大，当x=0．10时介电损耗最小；适量Nb2O5能使材料的介温曲线更加平缓，移峰作用明显。     

Dielectric properties of Bi<Subscript>4</Subscript>Ti<Subscript>3</Subscript>O<Subscript>12</Subscript> ceramics by impedance spectroscopic method

Various lead-free ceramics have been investigated in search for new high-temperature dielectrics. In particular, Bi₄Ti₃O₁₂ is a type of ferroelectric ceramics, which is supposed to replace leadcontaining ceramics for its outstanding dielectric properties in the near future. Ferroelectric ceramics of Bi₄Ti₃O₁₂ made by conventional mixed oxide route have been studied by impedance spectroscopy in a wide range of temperature. X-ray diffraction patterns show that Bi₄Ti₃O₁₂ ceramics are a single-phase of ferroelectric Bi-layered perovskite structure whether it is calcined at 800 °C or after sintering production. This study focused on the effect of the grain size on the electric properties of BIT ceramics. The BIT ceramics with different grain sizes were prepared at different sintering temperatures. Grain becomes coarser with the sintering temperature increasing by 50 °C, relative permittivity and dielectric loss also change a lot. When sintered at 1 100 °C, r values peak can reach 205.40 at a frequency of 100 kHz, the minimum dielectric losses of four different frequencies make no difference, all close to 0.027. The values of E _a range from 0.52 to 0.68 eV. The dielectric properties of the sample sintered at 1 100 °C are relatively better than those of the other samples by analyzing the relationship of the grain, the internal stresses, the homogeneity and the dielectric properties. SEM can better explain the results of the dielectric spectrum at different sintering temperatures. The results show that Bi₄Ti₃O₁₂ ceramics are a kind of dielectrics. Thus, Bi₄Ti₃O₁₂ can be used in high-temperature capacitors and microwave ceramics.