强度调制偏振光谱仪解调系数参考光测量方法

针对由理论计算得到的解调系数无法实现强度调制偏振光谱仪实验系统(以下简称“实验系统”)测量数据解调处理的问题,提出了测量参考光获取实验系统解调系数的解决方法.该方法通过测量已知偏振态参考光经过实验系统调制器后输出的强度谱,结合傅里叶变换、滤波和逆傅里叶变换等数字信号处理过程,可从测量结果中分离出实验系统的真实解调系数.分析了该方法的理论依据,给出了实验系统解调系数的实测结果,并利用得到的解调系数,对实验系统测量典型待测光源(近似自然光和完全线偏振光)的测量数据进行了解调处理.解调处理结果显示:在有效测量波段范围内(550～650 nm),以卤钨灯为光源的平行光管直接输出光的偏振度值约为10％;经过线偏振器起偏后,其偏振度值接近1O0％,与实际分析结果完全相符.验证了强度调制系统解调系数参考光测量方法的可行性.     

基于二阶摄动法求解区间参数结构动力响应

在处理区间参数结构动力响应问题时,现有的分析方法大多局限于一阶区间分析方法. 如果参数的不确定量稍大,采用一阶区间分析方法对结构动力响应范围进行估计可能会失效,所以需要考虑二阶区间分析方法.但是采用基于区间运算的二阶区间分析方法得到的结果将会对动力响应范围过分高估. 为了克服以上缺点,首先基于二阶摄动法得到结构动力响应广义函数. 然后通过求解此动力响应函数的最大和最小值,将结构动力响应区间的问题转化为序列低维箱型约束下的二次规划问题. 最后采用DC 算法(di erence of convex functionsalgorithm) 对这些箱型约束下的二次规划问题进行求解. 这样可以在不引入过多计算量的情况下,避免了对动力响应范围的过分估计. 通过数值算例,将该方法和其他区间分析方法进行比较,验证了该方法的有效性与精确性.     

红外紫外双色光谱的产生

本文给出了在红外光谱多外利用热受激后的原子材料产生紫外光谱的方法。文中给出了计算数据和实验结果。     

多肟基柚皮素衍生物的合成与细胞毒活性

以天然产物柚皮素(1)为原料,分别与α-溴代苯乙酮、α-溴代-4-氯苯乙酮、1-(2-溴乙基)-3-吲哚甲醛、α-溴代丙酮进行醚化反应得到7-(2-氧代-2-苯基乙氧基)柚皮素、7-(2-氧代-2-(4-氯苯基)乙氧基)柚皮素、7-(2-(3-甲酰基吲哚)乙氧基)柚皮素、7,4'-二(2-氧代丙氧基)柚皮素,然后分别与...     

玻璃钢渔船结构的特点

介绍了玻璃钢作为造船材料的特点与成型工艺、玻璃钢渔船结构中的板材、骨材以及玻璃钢渔船结构的类型。     

New method for lightning location using optical ground wire

A new technology of lightning location is described, which is based on detecting the state of polarization(SOP) fluctuation of the laser light in the optic ground wire (OPGW). Compared with the conventional lightning location method, the new method is more accurate, more stable, and cheaper. Theories of Stokes generated by lightning strike can still be accurately identified by detecting the velocity of polarization motion. A new algorithm to quantify the velocity is also introduced.     

Numerical computation of stress induced microstructure

The mesh transformation method is applied on a two-dimensional elastic crystal model to study the formation of laminated microstructure in austenite-martensite phase transition when certain external loads are applied. Numerical experiments show that simple laminated microstructures with various volume fractions and twin width can be obtained by varying the loads. Numerical experiments also show that second order laminated microstructure with branched needle-like laminates can also be obtained by certain loads.     

Glycerol-salt Mediated Stacking of Nucleic Acids in CZE

Nucleic acid samples with high concentrations of salt could be stacked and well separated during capillary zone electrophoresis (CZE) by adding glycerol into the samples and using a Tris-Borate-EDTA (TBE) buffer (pH 8.3) as the separation medium. The so-called glycerol-salt mediated stacking was found applicable to different types of nucleic acids. Three nucleic acids: a 16s rRNA (1,542 nt), a double stranded DNA (1.6 k bp), and a single stranded DNA (30 nt), were tested as demos in the experiments. When the sample matrix contained 50 mM KCl and 50% (w/v) glycerol, the 16s rRNA sample could be stacked as high as 30 times compared with the sample without KCl. All the nucleic acids could be stacked effectively when high concentrations of glycerol (>50%) and salt (more than 50 mM) were present in the sample matrix, while the dsDNA could be stacked with high concentrations of glycerol (>50%) alone. Cen Qi and Hongping Wei contributed equally to this work.     

Qualitative classification of COVID-19 by Raman spectra based on convolution neural networkEI北大核心CSCD

Taking the Raman spectra data of healthy people and sick people as experimental samplesa classification method of COVID-19 by Raman spectra based on convolution neural networkCNNwas proposed. In the training processit only needs to simply expand the sample data without complex preprocessing work. The training efficiency is higher than that of the traditional machine learning algorithms which depend on complex data preprocessing. Compared with K nearest neighborlogistic regression and support vector machinethe CNN has the highest classification accuracy of 96.77%. It's a new method for the detection of COVID-19. © 2022, Youke Publishing Co.,Ltd. All rights reserved.