The influence of thermally assisted tunneling on the performance of charge trapping memory

We evaluate the influence of the thermally assisted tunneling (TAT) mechanism on charge trapping memory (CTM) cell performance by numerical simulation, and comprehensively analyse the effects of the temperature, trap depth, distribution of trapped charge, gate voltage and parameters of TAT on erasing/programming speed and retention performance. TAT is an indispensable mechanism in CTM that can increase the detrapping probability of trapped charge. Our results reveal that the TAT effect causes the sensitivity of cell performance to temperature and it could affect the operational speed, especially for the erasing operation. The results show that the retention performance degrades compared with when the TAT mechanism is ignored.     

Spectroscopy and scattering matrices with nitrogen atom: Rydberg states and optical oscillator strengths

The scattering matrices of ${\rm e}+ {\rm N}^{+}$ with $J^\pi=1.5^{+}$ in discrete energy regions are calculated using the eigenchannel R-matrix method. We obtain good parameters of multichannel quantum defect theory (MQDT) that vary smoothly as the function of the energy resulting from the analytical continuation property of the scattering matrices. By employing the MQDT, all discrete energy levels for N could be calculated accurately without missing anyone. The MQDT parameters (i.e., scattering matrices) can be calibrated with the available precise spectroscopy values. In this work, the optical oscillator strengths for the transition between the ground state and Rydberg series are obtained, which provide rich data for the diagnostic analysis of plasma.     

离化态原子基态电子结构特征与轨道竞争规律

离化态原子广泛存在于等离子体物质中,其相关性质是天体物理、受控核聚变等前沿科学研究领域的重要基础.基于独立电子近似,本文系统研究了扩展周期表元素(2 Z 119)所有中性和离化态原子的基态电子结构.基于设计的原子轨道竞争图,系统总结了各周期元素轨道竞争的规律,并结合离化态原子的局域自洽势阐明了其轨道竞争(即轨道塌陷)的机制;在此基础上,说明了部分元素性质与轨道竞争的关系.利用本文研究得到的离化态原子基态电子结构,可建立更精密计算相关原子的能级结构、跃迁几率等物理量之基础,从而满足高功率自由电子激光实验分析、原子核质量精密测量等前沿研究的需求.     

化学亚胺化程度对正性光敏聚酰亚胺影响

选用2,2′-双三氟甲基-4,4′-联苯二胺(TFDB)与二苯醚四甲酸二酐(ODPA)作为聚合物的基本骨架进行缩聚反应生成聚酰胺酸,再经过化学亚胺化得到可溶性聚酰亚胺(PI)。通过调节2-甲基吡啶在亚胺化试剂中的含量以达到控制酰亚胺化程度的目的,探讨不同亚胺化程度的PI胶的显影性能。结果表明,当n(2-甲基吡啶)∶n(乙酸酐)=1∶5时,所合成的光敏聚酰亚胺的显影性能最优。