闪锌矿GaN/AIGaN耦合量子点中的类氢杂质态

在有效质量近似下,运用变分法计算了闪锌矿GaN/AIGaN耦合量子点中类氢杂质的施主束缚能.数值结果显示了类氢杂质的施主束缚能很大程度依赖于杂质位置和耦合量子点结构参数,当杂质位于量子点中心时,施主束缚能最大,而且随着中间垒宽的增加,杂质束缚能保持着先增加,然后不变的趋势.     

金属掺杂对半导体薄膜光学性质的影响

研究了射频溅射法制备的半导体膜的光学特性.通过样品透射谱分析,发现在半导体In2O3材料中掺入金属Fe颗粒的薄膜中,电子的带间跃迁由In2O3的直接跃迁变为间接跃迁;随Fe所占体积份数的增加,局域态尾变宽,带隙变窄.这是由于掺入Fe颗粒后,母体材料与金属颗粒的界面处表面态增多,以及母体材料的非晶化引起的.     

岩石抗拉强度试验方法的探讨

采用不同的试验方法 ,分别对大理岩、砂岩及花岗岩进行了抗拉强度试验。在对各种试验结果进行分析和比较的基础上 ,指出了每一种岩石抗拉强度试验方法的特点及适用条件     

试论20世纪社会主义国家对世界和平的贡献

社会主义国家自诞生以来，为争取世界和平做出了巨大的贡献。与此同时，社会主义国家也创制了如和平共处五项原则、不结盟政策等有利于世界和平的外交政策和原则     

NaI晶体能态密度的研究

EHMO方法结合特殊点方案,利用自包容子程序,计算了NaI晶体的态密度,确定了价级位置,得出了其能隙和价带宽度。     

近似决策规则的形成及其应用

Ziarko在变精度粗糙集的基础上提出近似约简，进而形成决策规则．该文是在研究Ziarko的决策规则的基础上提出了近似决策规则，并与Ziarko形成的决策规则进行了比较．     

EHMO方法对KI晶体电子结构的研究

ＥＨＭＯ方法结合特殊点方案，利用自包容子程序，计算了ＫＩ晶体的态密度，确定了价级位置，得出了其能隙和价带宽度。     

不协调信息的协调近似表示空间故障诊断方法

针对不协调、不完备信息条件下的故障诊断难题,研究了基于协调近似表示空间的故障诊断方法。采用不协调诊断信息系统描述不协调故障信息,并将不协调诊断信息系统转化为协调近似表示空间,进而对其进行属性约简;设计了基于包含度的针对完备信息对象的故障诊断方法,采用向量补齐方法设计了针对不完备信息对象的协调近似表示空间故障诊断方法。最后,将该方法应用于航空发动机故障诊断,验证了该方法可有效处理不协调、不完备信息,显著提高了故障诊断准确率。     

Two-dimensional linear connected-k system with trinary states and its reliability

Existing studies about two-dimensional consecutivek-out-of-n:F system is dealt with two states(either component or system):working or failure.A new model for two-dimensional linear consecutive-k-out-of-n:F system is proposed,in which the components and systems can be at any of the three states:full working,derating working,and failure.Furthermore,two engineering concrete instances of the new system are given.By using the finite Markov chain imbedding approach,the system reliability is presented in a unified formula with the product of matrices for the case of independent and identically distributed component states which can be extended to the independent but non-identical case easily.Finally,an example is given to illustrate the effectiveness of the above approach and tractability of various problems.     

Simulation of phase transition process using lattice Boltzmann method

A new lattice Boltzmann model based on SC model, is proposed to describe the liquid-vapor phase transitions. The new model is validated through the simulation of the one-component phase transition process. Compared with the simulation results of van der Waals gas and the Maxwell equal-area construction, the results of the new model have a better agreement with the analytical solutions than those of SC and Zhang models. Since the obtained temperature range and the maximum density ratio in this model are expanded, and the magnitude of maximum spurious current is only between those of SC and Zhang models, it is believed that this new model has better stability than SC and Zhang models. Consequently, the application scope of this new model is expanded compared with the existing phase transition models. According to the principle of the corresponding states in engineering thermodynamics, the simulations of ammonia and water phase transition process were implemented using this new model with different equations of state. Compared with the experimental data of ammonia and water, the results show that the Peng-Robinson is the best equation of state to describe the phase transition process of ammonia and water. Especially, the simulation results of ammonia with Peng-Robinson equation of state have an excellent agreement with its experimental data. Therefore these simulation results have a significant influence on the real engineering applications.