Objective : To evaluate the value of signal intensity ( SI ) and signal intensity ratio ( SIR ) on in-phase ( IP ) and opposed-phase ( OP ) chemical shift imaging in distinguishing benign and malignant vertebral lesions. 目的:评价同、反相位化学位移成像中的信号改变及信号强度比在鉴别脊柱良、恶性病变中的应用价值。
Frequency shift image in nc-AFM is studied by silicon tip scanning over rutile TiO2 ( 001 ) surface in vertical route and superposition s1 route with different parameters. 以等垂直距离路径和径向叠加s1路径,非接触原子力显微镜微悬臂Si针尖在金红石TiO2(001)面各种形状量子点表面沿[110]方向扫描,研究不同参数下的自振频率位移图像。
The gradual shift of the IR absorbing peak of samples in the course of carbonation from one characterizing the Si & O bond in calcium silicate hydrate to the one in SiO_2 gel has also been studied. 此外,在碳化过程中红外吸收峰由表征水化硅酸钙的SiO键向硅胶的SiO键逐渐转变。
IR spectra reveal that T-O-T antisymmetric stretch and ring stretch shift to lower wavenumber side with increasing the W content, this fact coincides with that the Si-O bond is substituted by longer W-O bond in the zeolite framework. 红外光谱研究表明,T-O-T反对称伸缩振动吸收峰和环振动吸收峰均随产物中W含量的增加而向低波数方向移动,这与分子筛骨架中W对Si的取代相一致。
The red shift of the Raman signals is due to the decrease of the bond-length because of stress existing in the samples. This situation causes a decrease in the oscillator strength of the Fe-Si bonds and leads to the red shift of the Raman signals. 拉曼信号的红移现象是由于样品中的应力的存在使得FeSi键长减小,从而引起FeSi键振子强度减少的结果。