CMOS电路总剂量效应最劣偏置甄别

采用电路分析和解析建模方法研究了CMOS电路中甄别总剂量效应最劣辐照与测试偏置的问题。通过引入小规模模拟电路和数字电路的例子进行具体分析,获取了不同电路的最劣偏置情况。对于数字电路,引入了敏感因子的概念用于定量计算不同辐照与测试偏置组合下电路的总剂量效应敏感程度。利用实测数据或电路仿真结果对甄别结果进行了一一验证,得到相一致的结论,证明了该研究思路的正确性。     

夸克蜕定域、色屏蔽和核力的中程吸引

本文描述了在通常的夸克势模型中的夸克蜕定域、色屏蔽及核力特性,对所得核子—核子绝热近似势和散射相移进行了定性描述:既有排斥心,又有中程吸引,但没有Van der Waals力问题,变分给出蜕定域的数值也是合理的,对质心运动效应、色屏蔽形式的影响以及各种单夸克基矢的关系和选择问题进行了专门的研究。 We introduce the quark delocalization and color screening into the usual quark modeland the property of nuclear force. The resulting N-N phase shifts and the adiabatic potential aredescribed qualitatively well: there are exclusion core and also intermediate range attraction, but thereis no Van der Waals force. The delocalization parameter obtained from variational method is alsoreasonable. we consider especially the effect of mass center motion, the effect of forms of colorscreening...     

Spectroscopic properties of thulium ions in bismuth silicate glass

A new type of bismuth silicate glass (Bi2O3-SiO2-ZnO-Al2O3-La2O3) doped with Tm2O3 is prepared by melt-quenching method. The thermal stability of the glass is examined by differential scanning calorimetry. No crystallization peak is found. Using the absorption and emission spectra, the absorption and emission cross-sections are calculated. Their maximum data are 2.9×10-21cm2 at 1663 nm and 4.7×10-21cm2 at 1826 nm, respectively. Using the Judd-Ofelt theory, the radiation transition probabilities and radiative lifetimes are obtained. The extended overlap integral method is applied to analyze energy transfer process among the Tm3+ ions. The transfer constants of cross-relaxation and energy migration among the Tm3+ ions at the 3H4 level are 7.60×10-40 and 14.98×10-40 cm6 /s, respectively. The critical transfer radius for cross-relaxation is 0.99 nm. The cross relaxation process is easy to realize and is favorable for obtaining ～2-μm laser.     

二维顶盖驱动半圆腔内流动MRT-LBM研究

本文采用多弛豫时间格子玻尔兹曼方法(multi relaxation time lattice Boltzmann method—MRT LBM)对二维顶盖驱动半圆腔内流动进行了数值模拟,得到了雷诺数为500～50000范围内半圆腔内流场分布情况。在二维顶盖驱动半圆腔流场中,随雷诺数的增大,流场内旋涡的数目逐渐增加,且流动依次呈现出稳定流、周期流、混沌流等状态。本文计算结果表明,MRT-LBM模型可显著提高计算的稳定性,适用于大范围的雷诺数流动情况。     

Improving InGaN-LED performance by optimizing the patterned sapphire substrate shape

The epitaxial growths of GaN films and GaN-based LEDs on various patterned sapphire substrates (PSSes) with different values of fill factor (f) and slanted angle (θ) are investigated in detail. The threading dislocation (TD) density is lower in the film grown on the PSS with a smaller fill factor, resulting in a higher internal quantum efficiency (IQE). Also the ability of the LED to withstand the electrostatic discharge (ESD) increases as the fill factor decreases. The illumination output power of the LED is affected by both θ and f. It is found that the illumination output power of the LED grown on the PSS with a lower production of tanθ and f is higher than that with a higher production of tanθ and f.     

Interaction between graphene and the surface of SiO2

The interaction between graphene and a SiO(2) surface has been analyzed with first-principles DFT calculations by constructing the different configurations based on α-quartz and cristobalite structures. The fact that single-layer graphene can stay stably on a SiO(2) surface is explained based on a general consideration of the configuration structures of the SiO(2) surface. It is found that the oxygen defect in a SiO(2) surface can shift the Fermi level of graphene down which opens up the mechanism of the hole-doping effect of graphene adsorbed on a SiO(2) surface observed in a lot of experiments.     

快速凝固Cu-Pb过偏晶合金的性能表征

研究了Cu-Pb过偏晶合金的急冷快速凝固组织特征,定量表征了快速凝固Cu-Pb过偏晶合金的电阻率和力学性能,理论分析了冷却速率和组织形态对合金性能的影响规律. 研究结果表明,在急冷快速凝固条件下,Cu-Pb过偏晶合金中的(Cu)相和(Pb)相均以枝晶方式生长,晶体形态以均匀细小的等轴晶为特征. 随着冷却速率增大,一方面,凝固组织显著细化,晶界增多,对自由电子的散射作用增强,合金电阻率显著增大;另一方面,细晶强化作用增强,合金的抗拉强度呈线性升高,同时,伴随着晶体缺陷数量的增多,合金的伸长率降低. 关键词： Cu-Pb过偏晶合金 快速凝固 电阻率 力学性能     

Ferromagnetism in noncompensated (Mn,Ga)-codoped ZnO films

Mn/Ga noncompensated codoped ZnO films were prepared on c-cut sapphire substrates via pulsed laser deposition. The structural, magnetic, transport, and optical properties of the films were then investigated. Addition of the Ga donor increases the electron concentration and enhances the magnetization in these films because of the net negative charge of the special noncompensated codoping, which can adjust the carrier concentration as well as the magnetic moment. Moreover, the Fermi level moves into the conduction band because of the increase in electron concentration, which results in an increase in the optical band gap value, from 3.28 eV for the undoped ZnO film to 3.61 eV for the (Mn,Ga)-codoped ZnO film.     

Preservation of entanglement in a two-qubit-spin coupled system

A theoretical scheme for preserving the entanglement in a two-qubit-spin coupled system in the presence of Dzyaloshinskii–Moriya (DM) anisotropic antisymmetric interaction is proposed. On the basis of a sequence of operations performed periodically on the system, the scheme can preserve the entanglement of the system starting from any initial state with any desired high precision for any desired long duration.     

结构与参量不确定的网络与网络之间的混沌同步

进行了结构与参量不确定的网络与网络之间的混沌同步研究．通过设计适当的控制输入,不但实现了两个复杂网络之间的混沌同步,而且网络节点状态方程中的未知参量和网络内部节点之间的耦合强度也被同时确定．通过采用具有调制损耗的CO2激光器的状态方程进行仿真实验,发现网络与网络之间的同步性能非常稳定．