Effect of Hydrogen Implantation on SIMOX SOI Materials

Hydrogen ions were implanted into separation by implantation of oxygen (SIMOX) silicon-on-insulator (SOI) wafers near the oxygen-implantation-induced damage peak under different conditions of energy and dose. It was found that the implanted hydrogen ions not only accelerate the diffusion of oxygen atoms from the annealing ambience into the wafer but also cause an outward diffusion of oxygen atoms in the buried oxide (BOX) layer. Thus, greatly broadened buried oxygen-rich (BOR) layers were formed in our experiments, which are 18%-79% broader than the BOX layer of standard SIMOX SOI wafers under the same conditions of oxygen implantation. The mechanism was discussed. A potential low cost method to fabricate SIMOX SOI wafers is proposed.     

Yb:FAP和Yb:C3S2-FAP晶体光谱的温度特性和选择激发

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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.     

Equation of State of Dense Liquid Nitrogen in the Region of the Dissociative Phase Transition

We have measured the equation of state for liquid nitrogen compressed dynamically to a pressure of 10-60 GPa by employing a two-stage light-gas gun.The data show a continuous phase transition above the shock pressure of 33GPa,as indicated previously by shock wave experiments.A theoretical model has been derived to examine the experimental data by inducing a molecular dissociative fraction.According to theoretical and experimental date the phase transition was thought to be a molecular dissociative phase transition.     

类氢类氦类锂镁离子双电子复合的旁观电子角动量研究

类氢类氦类锂镁离子经中间双激发态进行的双电子复合过程在研究惯性约束聚变电子温度中占有很重要的地位.用准相对论方法计算了双电子复合经不同Rydberg态跃迁通道的复合速率系数,并给出不同离化度离子的双电子复合速率系数随电子温度的变化规律.显示出离子的相关能对峰值的电子温度有很大影响,当类氢离子跃迁通道的旁观电子角动量为1时双电子复合系数最大,而类锂离子是旁观电子角动量为3时最大. 关键词： 双电子复合 镁离子 角动量     

第一届掺杂纳米材料发光性质学术会议

该会议为中国物理学会发光分会、中国稀土学会发光专业委员主办的国内首次纳米材料发光性质专题学术研讨会，旨在通过大会报告、专题研讨等活动，总结、交流近年来掺杂纳米发光材料及其相关应用领域所取得的研究进展和成果。在此基础上凝练科学目标、探讨和规划未来的学科发展方向并集中国内的优势资源攻克难点的科学问题，使我国在该研究领域更具国际竞争力。会议诚邀请该领域知名的专家和学者参加；在探索纳米世界之余，也将带您领略海南美丽而独特的自然景观和人文奇迹。     

相互作用玻色子模型中相变特征量的玻色子数N依赖行为

研究了相互作用玻色子模型中各种对相变比较敏感的特征量相对于总玻色子数N的依赖行为. 通过比较这些特征量在U(5)-SU(3)过渡区以及U(5)-O(6)过渡区在不同N情况下的临界行为, 发现BE(2)比值B(E2;4₁→2₁)/B(E2};2₁→0₁)和B(E2;0₂→2₁)/B(E2;2₁→0₁)等可以作为完全区分一级相变和二级相变的有效序参量.     

精密垫片精冲工艺有限元分析与模具设计

精密垫片零件，如图1所示，零件材料为1Cr18Ni9Ti，强度大（σb=650MPa），有一定塑性。从零件尺寸精度看，φ4mm外圆为IT7级精度，φ4mm外圆与φ2mm内孔有很高的同轴度要求，冲裁断面与零件两端面有垂直度要求，普通冲压不能达到零件精度：从工序的角度看，有冲孔和落料工序，剪切面粗糙度Ra≤3．2μm，属于光洁冲裁范畴；另外，技术条件中要求零件两大面不得有任何划伤，且光滑平整。总体上看，该零件的冲压加工性不好，难度较大，对模具的设计、选材、制造要求都较高。