位移谐振子模型对三(2-苯基吡啶)合铱磷光光谱影响的理论研究

采用谐振子模型理论探讨了振动模式对Ir(ppy)₃配合物的磷光光谱的影响.多原子分子发射光谱的一般形式可以从两个绝热电子态之间的热振动关联函数推导出,相应地势能面之间的位移和Duschinsky转动的影响也被包含在多维谐振子模型的表达式中,所得关系式模拟出了Ir(ppy)₃较为精细的磷光发射光谱.计算结果表明T₁态到S₀态之间的0→1振动跃迁对发射光谱贡献较大,尤其振动频率小于1600 cm^-1的振动模贡献更多,配体中苯和吡啶环上C=C和C=N的呼吸振动,是Ir(ppy)₃出现肩峰的主要原因.玻耳兹曼分布使得主峰和肩峰的强度下降,并且两峰相互接近.该谐振子模型与密度泛函理论(DFT)结合,可以较好地定量描述多原子分子光物理过程的发射光谱以及详细了解光谱谱图的细节.     

金属表面荧光增强的物理增强机制

具有特殊形貌及构型的表面(如金属薄膜)能够使位于其邻近的荧光分子的荧光信号得到增强, 这种现象被称之为表面增强荧光(Surface Enhanced Fluorescence, SEF)。有关表面增强荧光效应的研究探讨已有许多报道,并先后提出了多种增强机理以试图理解和解释观测到的实验现象。本文将在总结归纳已有机理研究的基础上,从物理学的角度出发分析理解局域场增强、能量转移以及辐射衰减速率增加等理论模型,并对衬底表面与荧光分子之间的间距变化对增强效果的影响进行探讨。     

共价作用于自组装膜修饰电极表面的多巴胺电化学行为研究

在过去的半个世纪里,由于多巴胺 (DA)在神经传导中的重要作用,引起了分析工作者尤其是电分析工作者的广泛兴趣.     

研究性实验教学探索与应用型人才培养——以巯基聚倍半硅氧烷的制备及其吸附性能实验为例

从应用型人才培养角度出发,以“巯基聚倍半硅氧烷的制备及其吸附性能”实验为教学案例,阐述了在高分子材料与工程专业中采用研究性实验教学的必要性,并从课程设计、教学过程等方面对研究性实验教学模式进行了探索.     

Magnetic properties of misch-metal partially substituted Nd–Fe–B magnets sintered by dual alloy method

The misch-metal(MM) partially substituted Nd–Fe–B sintered magnets were fabricated by the dual alloy method,and the crystal structure, microstructure, and magnetic properties were analyzed comprehensively. X-ray diffraction(XRD)reveals that the increasing content of the MM has an inconsiderable effect on the crystallographic alignment of the magnets.Grains of the two main phases are uniformly distributed, and slightly deteriorate on the grain boundary. Due to the diffusion between the adjacent grains, the MM substituted Nd–Fe–B magnets contain three types of components with different Ce/La concentrations. Moreover, the first-order reversal curve(FORC) diagram is introduced to analyze the magnetization reversal process, coercivity mechanism, and distribution of reversal field in magnetic samples. The analysis indicates that there are two major reversal components, corresponding to the two different main phases. The domain nucleation and growth are determined to be the leading mechanism in controlling the magnetization reversal processes of the magnets sintered by the dual alloy method.     

不同驱动力对Cz硅生长中熔体对流影响的数值模拟研究

为了确定Cz单晶硅生长各种驱动力对熔体对流及固/液界面形状的影响,利用CGSim软件,对典型的Cz单晶硅生长中的熔体对流进行数值模拟.研究了重力、表面张力、平流力、晶转、埚转和氩气剪切力等各种驱动力的大小对熔体对流涡胞、涡胞强度、界面形状、温度分布的影响.结果表明:各种驱动力对熔体对流的影响大小依次为:浮力＞表面张力＞晶转力＞氩气剪切力＞埚转力＞平流力;浮力和表面张力使熔体产生一沿坩埚壁上升、从固/液界面附近下降的涡胞,晶转力和氩气剪切力使熔体产生与前面反方向的涡胞,而埚转力产生多个不同流向的对流涡胞,使熔体混合更加均匀,熔体凝固引起的平流力对熔体对流影响不大;增大埚转,熔体中涡胞数量更多、对流换热更充分、温度梯度更小、熔体内的最高温度更低,有利于减少石英坩埚氧的熔解,但界面更向下凹;增大晶转,熔体内的最高温度无明显变化;固定埚转Ωc=-10 r/min,晶转存在一临界值Ωs(C)=60～ 80 r/min,当Ωs＜Ωs(C)时,增大晶转,固/液界面更向上凹,当Ωs＞Ωs(C)时,增大晶转,固/液界面更向下凹.     

A vertical test system for China-ADS project injector II superconducting cavities

To test superconducting cavities, a vertical test system has been designed and set up at the Institute of Modern Physics （IMP）. The system design is based on VCO-PLL hardware and the NI Labview software. The test of the HWR010#2 superconducting cavity shows that the function of this test system is satisfactory for testing the low frequency cavity.     

A vertical test system for China-ADS project injector Ⅱ superconducting cavities

To test superconducting cavities, a vertical test system has been designed and set up at the Institute of Modern Physics (IMP). The system design is based on VCO-PLL hardware and the NI Labview software. The test of the HWR010#2 superconducting cavity shows that the function of this test system is satisfactory for testing the low frequency cavity.     

Imaginary Part of the Surface Tension of Water

We report a direct measurement of the imaginary part of the surface tension of water through a dynamic scheme using a thin vertical glass fiber of diameter of 3 tun with one end glued onto a cantilever beam and the other end touching a water-air interface. The frequency dependence of the dissipation factor experienced by the glass fiber is exactly calculated through measuring the phase delay with various frequencies when the glass fiber is forced to oscillate vertically. We find the same intercept at the dissipation factor axis for different frequency dependences of the dissipation factor for different depths by which the glass fiber is dipped into water. This nonzero dissipation factor at zero frequency presents direct evidence of the existence of the imaginary part of surface tension of water and yields a complex surface tension of water σ^＊ = 0.073 ＋ i（0.017 ± 0.002） N/m at room temperature.     

基于纳米金自组装膜固定辣根过氧化物酶的生物传感研究

将辣根过氧化物酶(HRP)通过纳米技术和自组装技术固定于电极表面,制得了酶修饰电极.纳米金与HRP形成了静电复合物并高效地保持了HRP的生物活性,以对苯二酚作为电子媒介体,差示脉冲伏安法(DPV)研究生物酶电极测定H2O2的线性范围为5.0×10-6～1.0×10-3 mol/L,检测限为2.5×10-6 mol/L,线性方程为△I=0.34765+4.05553CH2O2(mM).酶电极的表观米氏常数(K(app))为0.0675 mmol/L.实验同时证明该生物酶电极具有良好的稳定性和使用寿命.