日本大学中物理学导论的教育

此文系中山正敏教授在1992年9月9日于日本东海大学举办的ASPEN国际会议上的报告     

Exchange Coupling and Stability of SmCo7-xHfx

Electronic structure of SmCo7-xHfx compound is calculated by using the multi-scattering Xα method. It is shown that a few of electrons can transfer to the Sm 5d orbital due to orbital hybridization between Sm and Co atoms. The 3d-5d coupling is stronger, which is the main reason to result in the long-range ferromagnetic order between Sm and Co atoms in SmCo7-xHfx. According to the Stoner criterion, the result of spin-unpolarized calculation for the Sm5Co32Hf2 duster could lead to a better understanding of why the ferromagnetic SmCo7-xHfx is a stable phase. For the Sm5Co32Hf2 duster the Fermi level is situated at the overall maximum of the density of states. Moreover the duster wavefunctions at EF are antibonding and hence highly localized in real space, which would lead to a large value for the duster Stoner integral. Thus a rationalization for the magnetic stability of SmCo7-xHfx has been obtained.     

Z-pinch内爆等离子体时空分辨诊断技术

 为了深入认识和理解Z-pinch物理机制并对物理实验进行优化设计，需要研究内爆等离子体及其辐射的时空分布特性诊断技术，建立诊断装置与设备，通过实验研究等离子体内爆时间过程及其空间分布特性，利用所获得的实验诊断数据校核数值模拟程序。简要介绍近几年开展的X光空间积分功率谱测量、X光时间积分针孔照相、X光时分幅针孔照相、X光时间分辨1维空间分布、紫外探针阴影照相等时空分辨诊断技术研究工作，并给出在1~3 MA电流驱动装置上进行的喷气和丝阵内爆实验中获得的部分时空分辨诊断结果，包括辐射功率、拉链速度、内爆速度、收缩比等。     

丝阵Z箍缩1维X射线辐射功率分布的数据处理

 在丝阵Z箍缩实验中利用CCD记录X射线辐射功率的1维时空分布图像，对光纤传输效率、图像聚焦、MCP与CCD的耦合效率等因素造成的图像失真进行了处理，利用实验实测的单光纤点扩展图像和光传输效率曲线对辐射功率分布图像进行处理，并修正光纤传输效率以及MCP和CCD间耦合效率不均匀性的影响以还原X射线辐射功率的1维空间分布信息。处理后将图像沿空间积分获得了与X射线功率谱仪相吻合的X射线辐射功率脉冲波形，同时不同发次由两系统得到的X射线波形的前沿之间也表现出了良好的一致性。     

Determination of Tungsten Layer Profiles in Bilayer Structures Using X-Ray Reflectivity Method

An effectual method is presented to determine the profiles of a tungsten （W） layer, such as the density, the thickness and the roughness in the multilayer structures, using the x-ray reflectivity technique. To avoid oxidation effects of tungsten, a B4 C capping layer is deposited onto to the W layer. To observe the profiles of the tungsten layer with different thicknesses, three groups of W/B4 C bilayers with different thicknesses are prepared by using ultra high vacuum dc magnetron sputtering and measured by an x-ray diffractometer. A type of genetic algorithm called the differential evolution is used to simulate the measurement data so as to obtain the parameters of bilayers. According to the simulation, it is shown that the W layer density varies from 95.26% to 97.51% compared to the bulk. In our experiment, the deposition rate is 0.044 nm/s, and the thickness is varied in the range of 9.8-19.4 nm.     

Super-Resolution Recording by an Organic Photochromic Mask Layer

By using the super-resolution near-field structure （super-RENS） method, the super-resolution recording marks are obtained practically by an organic photochromic diarylethene mask layer, under much lower recording laser power of 0.45roW. The size of recording marks is decreased by 60% （from 1.6μm to 0.7μm） for a diarylethene （photo-mode） recording layer by the optical detection method （limited by optical diffraction）, or decreased by 97% （from 160Onto to 5Onto） for a heptaoxyl copper phthalocyanine （thermo-optical） recording layer, the latter is much smaller than the limitation of optical diffraction. In order to obtain a desirable result, a proper extent of photochemistry reaction in the mask layer is needed. Thus, the super-resolution recording marks can be obtained by adjusting the concentration of diarylethene in the mask layer, the recording laser power, and the moving speed of the sample disc.     

Meso-四(3,5-二溴-4-羟基苯基)卟啉褪色光度法测定蛋白质的研究与应用

采用吸光光度法研究了meso-四(3,5-二溴-4-羟基苯基)卟啉[T(DBHP)P]作为新型光谱探针与蛋白质相互作用的光谱行为。发现在pH 4.17 Britton-Robinson缓冲液中,吐温-80(Tween-80)微乳液介质可以显著增强了体系的灵敏度。在最佳实验条件下,考察了T(DBHP)P-蛋白质体系的吸收光谱特性,于425 nm处蛋白质的浓度在一定范围内与吸光度A呈良好的线性关系。分别用于测定牛血清白蛋白(BSA)和卵血清白蛋白(Ova),线性范围分别为0.50～6.00 μg·mL-1和0.05～0.60 μg·mL-1,检出限分别为0.11和0.039 μg·mL-1。实验结果表明,该方法具有较高的灵敏度、选择性和稳定性,成功地用于牛奶样品中蛋白质的测定,回收率为99.56%～100.2%,相对标准偏差低于2.2%。从而建立了一种测定蛋白质的灵敏方法并用于食品分析领域中。另外考察了离子强度及温度对体系的影响。     

荧光光谱法研究二溴羟基卟啉与蛋白质的结合作用机理

应用荧光光谱法研究了meso-四(3,5-二溴-4-羟基苯基)卟啉[T(DBHP)P]与牛血清白蛋白(BSA)之间的结合反应,基于T(DBHP)P对BSA内源荧光的猝灭机理,测定了两者之间在不同温度下的结合常数,温度为27 ℃时,荧光猝灭法测得反应的结合常数为K=1.30×106 L·mol-1,温度为48 ℃时,K=6.32×105 L·mol-1,结合常数随温度升高而减小,由此判定该猝灭类型为静态猝灭。根据Frster非辐射能量转移理论,确定了T(DBHP)P与BSA之间的能量转移效率E=0.91,能量给体(BSA)与受体[T(DBHP)P]之间的结合距离r=2.39 nm<7 nm,符合非辐射能量转移条件。依据热力学参数ΔG<0,ΔH<0,ΔS>0确定了T(DBHP)P与BSA之间的作用力主要是静电引力。同时,利用同步荧光光谱,考察了T(DBHP)P对BSA构象的影响,结果发现,T(DBHP)P的加入使BSA构象发生变化,BSA内部残基所处环境的疏水性降低。     

色散缓变光纤中飞秒光脉冲的调制不稳定性研究

研究了色散缓变光纤中飞秒光脉冲的调制不稳定性 ,发现当色散缓变光纤的色散参量满足一定关系式时 ,增益谱的谱宽最宽 ,获得了增益谱的表达式 ;三阶色散对调制不稳定性不起作用 ;自变陡效应使增益谱的谱宽变窄 ,振幅的增长速度减漫 ;拉曼效应改变了调制不稳定性的产生区域。