非灰介质中辐射直接交换面积的计算

用宽带胶其修正模型模拟非灰介质的辐射特性，并将它用于区域法模型，计算了非灰气体介质中表面一表面之间的辐射直接交换面积。结果表明，修正的宽带模型对气体辐射特性的描述是比较准确的，且它易于与区域法相结合。     

软X光辐射烧蚀实验方法研究

 用强激光辐照金箔靶，以金箔背侧软X光辐射为基础，提出了软X光辐射烧蚀研究的新靶型、新方法，做了C₈H₈样品辐射烧蚀初步实验。     

e-A深度非弹性散射中胶子辐射振幅的新计算方法

在e-A深度非弹性散射过程中, 喷注穿过冷核介质时, 多重散射诱导胶子辐射会导致对碎裂函数的修正及喷注的能量损失.前期研究中关于计算e-A深度非弹性散射中胶子辐射振幅的两种方法: 螺旋振幅近似和微扰QCD严格计算都异常繁杂. 本文发展了一种新的方法, 可以方便计算出多重散射导致胶子辐射的振幅, 得到的碎裂函数的修正以及能量损失与严格计算的结果一致.     

密度泛函估计的重对数律，中心极限定理和不变原理

设X_1,…,X_n是从分布密度为f(单变量实值函数)的总体中抽出的iid.样本.μ=EX_1。本文研究了密度泛函θ=f(μ)的核型估计为通常的Rosenblatt-Parzen核估计)的大样本性质。     

Total Dose Radiation Tolerance of Phase Change Memory Cell with GeSbTe Alloy

Phase change memory （PCM） cell array is fabricated by a standard complementary metal-oxide-semiconductor process and the subsequent special fabrication technique. A chalcogenide Ge2Sb2Te5 film in thickness 50hm deposited by rf magnetron sputtering is used as storage medium for the PCM cell. Large snap-back effect is observed in current-voltage characteristics, indicating the phase transition from an amorphous state （higher resistance state） to the crystalline state （lower resistance state）. The resistance of amorphous state is two orders of magnitude larger than that of the crystalline state from the resistance measurement, and the threshold current needed for phase transition of our fabricated PCM cell array is very low （only several μA）. An x-ray total dose radiation test is carried out on the PCM cell array and the results show that this kind of PCM cell has excellent total dose radiation tolerance with total dose up to 2 ×10^6 rad（Si）, which makes it attractive for space-based applications.     

中国科学院超快现象和太赫兹辐射学术研讨会简讯

“中国科学院超快现象和太赫兹辐射学术研讨会”于 2 0 0 2年 7月 2 2日至 2 5日在北京中国科学院物理研究所举行 .本次会议由中国科学院主办 ,中国科学院物理研究所承办 ,中国科学院上海微系统与信息技术研究所、美国伦斯勒理工学院共同协办 .会议的三位主席分别是物理所张杰研究员、美国伦斯勒理工学院的张希成教授和上海微系统与信息技术研究所的封松林研究员 .物理所的翁羽翔研究员担任会议秘书长 .这次大会是我国在超快现象和太赫兹辐射领域组织的第一次专业学术会议 ,是对国内在超快现象和太赫兹辐射领域研究水平的一次较全面的检阅 .…     

Spectrum Simulation of Li-Like Aluminium Plasma

X-ray emission spectra for L-shell of Li-like aluminium ions are simulated by using the flexible atomic code based on the collisional radiative model. Atomic processes including radiative recombination, dielectronic recombination, collisional ionization and resonance excitation from the neighbouring ion （Al^9＋ and Al^11＋ ） charge states of the target ion （Al^10＋） are considered in the model. In addition, the contributions of different atomic processes to the x-ray spectrum are analysed. The results show that dielectronic recombination, radiative recombination, collisional ionization and resonance excitation, other than direct collisional excitation, are very important processes.     

吸积盘的X射线辐射对周围星际物质的离化研究

利用辐射流体力学程序对三倍频纳秒激光与靶物质相互作用进行了模拟研究，得到了可以产生黑体辐射谱分布的激光等离子体X射线辐射靶的最佳厚度；数值模拟研究了黑体谱分布的X射线辐射场对等离子体系统平均离化度分布的影响，它有助于深入理解天体物理中吸积盘对它周围星际物质的离化影响. 关键词： 辐射流体力学 激光等离子体 X射线辐射 吸积盘 离化     

Interferences in Photodetachment of a Negative Molecular Ion

The photodetachment of a negative molecular ion is studied theoretically using a two-center model. The detached electron wave function is obtained as a superposition of two coherent waves originating from each center. The photo-detached electron flux is evaluated on a screen placed at a large distance from the negative molecular ion. The electron flux on the screen displays strong interferences, the peak positions are related to the distance between the two centers in the negative molecular ion. We a/so obtained a simple analytical formula for the total photodetachment cross section. It approaches one and two times of the cross section for the one-center system in the high and lowphoton energy limits respectively.     

Effect of Nonradiative Recombination on Carrier Dynamics in GaInNAs/GaAs Quantum Wells

The nonradiative recombination effect on carrier dynamics in GalnNAs/GaAs quantum wells is studied by timeresolved photoluminescence （TRPL） and polarization-dependent TRPL at various excitation intensities. It is found that both recombination dynamics and spin relaxation dynamics strongly depend on the excitation intensity. Under moderate excitation intensities the PL decay curves exhibit unusual non-exponential behaviour. This result is well simulated by a rate equation involving both the radiative and non-radiative recombinations via the introduction of a new parameter of the effective concentration of nonradiative recombination centres in the rate equation. In the spin dynamics study, the spin relaxation also shows strong excitation power dependence. Under the high excitation power an increase of spin polarization degree with time is observed. This new finding provides a useful hint that the spin process can be controlled by excitation power in GaInNAs systems.