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采用火焰原子吸收光谱法对补阴药石斛、玉竹、北沙参、女贞子和补阳药肉苁蓉、杜仲、菟丝子、补骨脂8味中药进行Fe、Mg、Zn、Ca、Mn、Cu含量测定。结果表明,以平均值而论Mg、Cu含量补阴药与补阳药相当,Fe、Ca含量补阴药低于补阳药,Zn、Mn含量补阴药高于补阳药。以每味中药而论,补阳药菟丝子Fe含量最高,是其他几味中药的近10倍,补阴药石斛Zn、Mn含量最高,是其他几味中药的3~10倍。补阴药、补阳药药效是相对的,但本实验测定各微量元素含量并没有呈现相对性,因此,补阴药、补阳药的药效与Fe、Mg、Zn、Ca、Mn、Cu微量元素的相关性有待于进一步研究。 相似文献
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采用蒙特卡罗方法对闪烁光纤阵列探测器在高能X射线入射下的串扰进行了模拟研究,并且分析比较了加铅层对串扰的影响.研究中采用对表征成像系统空间分辨率参量——调制传递函数进行模拟分析和比较,得到在光纤阵列之间加入不同铅层厚度后对系统调制传递函数参量曲线的影响.研究结果表明:在高能射线下,采用闪烁光纤阵列作为成像探测器存在严重的次级粒子相互串扰的现象,而在阵列之间加入铅介质能够减少这种效应;但另一方面,若所加铅层太厚又会导致成像探测器像素过大而使得空间分辨率下降.通过模拟计算得出:只要在阵列之间加入适当厚度的铅介质,既可以有效抑止阵列之间次级粒子的串扰,同时又能提高闪烁光纤阵列探测器系统的空间分辨率. 相似文献
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Infrared absorption spectra of gaseous CH2Cl2 in the regions of 1200-12000 cm-1 were measured using a Bruker IFS 120HR Fourier transform spectrometer in conjunction with a multipass cell. 47 vibrational levels of overtone and combinational spectral lines of the CH stretching (v1, v6), bending (v2), and rocking(v8) modes were analyzed and assigned. Utilizing the normal mode model and considering the coupling among CH stretching, bending and rocking vibrations, values of the harmonic frequency ωi, the anharmonic constant xij, and the coefficients of Fermi and the Darling-Dennison resonances of v1, v6, v2 and v8 modes were also determined from experimental spectral data with nonlinear least-square fitting. These spectral constants reproduced the experimental levels very well. These results showed that Fermi resonance between CH stretching and rocking vibrations (ki88=-254.63 cm-1) is stronger than that between CH stretching and bending vibrations (k122 = 54.87 cm-1); and that Darling-Dennison resonances between CH stretching and bending vibrations (k1166=-215.28 cm-1) is also much stronger than that between CH bending and rocking vibrations (k2288=-5.72 cm-1). 相似文献
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