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31.
采用傅里叶变换红外光谱结合相关性分析、二阶导数谱和二维相关谱对13种常见野生蘑菇进行鉴别研究。结果显示13种野生蘑菇的红外光谱光谱特征相似,主要由蛋白质、多糖的吸收组成,13种样品的相关系数最小为0.779,最大值为0.960。在1 700~1 400和1 400~800 cm-1范围的二阶导数光谱中,各样品吸收峰的强度、位置和形状均有明显差异。二维相关红外光谱在1 380~1 680 cm-1范围的强自动峰整体相近,但自动峰和交叉峰位置、形状存在差异;在920~1 230 cm-1的范围,各样品的自动峰和交叉峰的数量、强度和位置差异明显。结果表明傅里叶变换红外光谱结合相关性分析、二阶导数谱和二维相关谱有望发展为区分不同种类蘑菇的快速方法。 相似文献
32.
Taking flood catastrophe risk in China as the research background, aiming at the characteristics of flood loss ``low frequency and high loss', Bayesian inference method is used to fit the loss distribution, and Bayesian inference is used to obtain the loss frequency distribution and loss quota distribution of flood in China.
On this basis, Monte Carlo simulation method is used to calculate the probability distribution of annual flood loss in China under different trigger conditions, and then CAPM is used to study the pricing of flood catastrophe bonds in China. It is concluded that under different trigger conditions, as the trigger value increases gradually, the corresponding trigger is triggered. Comparing the three types of bonds, it can be found that the price of bonds decreases with the decrease of principal guarantee ratio and the increase of principal loss ratio, that is, the investment risk is directly proportional to the return, which provides reference for
issuing flood catastrophe bonds in China. 相似文献
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Correlation between Chaotic Dynamics and Level Spacings: the Lyapunov and Dixon Dip Approaches to Highly Excited Vibration of Deuterium Cyanide 下载免费PDF全文
Chaotic dynamics of highly excited vibration of deuterium cyanide is explored by two independent approaches: (1) the Lyapunov analysis, based on the classical phase space for the levels, and (2) the Dixon dip analysis based on the concepts of pendulum dynamics and quantized levels. The results show that there is evident correlation between these two algorithms. We also propose that the reciprocal of energy difference between two nearby Dixon dips can be taken as a qualitative measure for the degree of dynamical chaos. 相似文献
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Background
Major depression is a serious mood disorder affecting millions of adults and children worldwide. While the etiopathology of depression remains obscure, antidepressant medications increase synaptic levels of monoamine neurotransmitters in brain regions associated with the disease. Monoamine transmitters activate multiple signaling cascades some of which have been investigated as potential mediators of depression or antidepressant drug action. However, the diacylglycerol arm of phosphoinositide signaling cascades has not been systematically investigated, even though downstream targets of this cascade have been implicated in depression. With the ultimate goal of uncovering the primary postsynaptic actions that may initiate cellular antidepressive signaling, we have examined the antidepressant-induced production of CDP-diacylglycerol which is both a product of diacylglycerol phosphorylation and a precursor for the synthesis of physiologically critical glycerophospholipids such as the phosphatidylinositides. For this, drug effects on [3H]cytidine-labeled CDP-diacylglycerol and [3H]inositol-labeled phosphatidylinositides were measured in response to the tricyclics desipramine and imipramine, the selective serotonin reuptake inhibitors fluoxetine and paroxetine, the atypical antidepressants maprotiline and nomifensine, and several monoamine oxidase inhibitors. 相似文献39.
Disentangling the Effects of Thickness of the Neutron Skin and Symmetry Potential in Nucleon Induced Reactions on Sn Isotopes 下载免费PDF全文
The effects of density dependence of symmetry energy and the thickness of the neutron skin in proton (neutron) induced reactions on Sn isotopes are investigated by means of the improved molecular dynamics model. The investigation shows that the target size dependence of the reaction cross sections for proton induced reactions on Sn isotopes is sensitive to the density dependence of the symmetry energy and less sensitive to the thickness of the neutron skin of the target nuclei, but that, for neutron induced reactions on Sn isotopes, it is less sensitive to the density dependence of the symmetry energy and sensitive to the thickness of the neutron skin of the target nucleus. 相似文献
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一类奇摄动方程的PLK方法 总被引:1,自引:0,他引:1
通过对坐标作包含因变量的非线性泛函的变换,以首项渐近解和相应的坐标变换给出原问题的二阶的近似解,并把这种思想进一步推广到更复杂的非线性方程,用较为简洁的方法求得了一类非线性方程的二阶渐近解. 相似文献