近红外光谱温度修正定量分析模型的研究

以小麦粉末样品为实验材料,研究了环境温度对近红外光谱定量分析结果的影响。将环境温度作为外部变量,使用不同温度下的45个样品建立了测定小麦蛋白质含量的温度修正模型,预测不同温度下的小麦样品的蛋白质含量,结果同以22 ℃恒温下45个样品建立的模型进行了比较。分析结果表明：温度修正模型的预测标准差(SEP)平均为0.333,而恒温模型(22 ℃)的预测标准差随着环境温度与建模时温度差的增大而增大,当环境温度4 ℃时,SEP=0.601 6。温度修正模型可以有效的提高近红外光谱定量分析精度。     

On J-integrals in the plane fracture

In this paper,we discuss J-integrals near modelsⅠandⅡcrack tips for the plates oflinear-elastic isotropic homogeneous material and orthotropic composite material,usingthe theories of complex function and calculus,and obtain the result as follows:(1)The various J-integrals are transformed into standard form of line integrals withrespect to coordinates:J=∫_rP(x,y)dx Q(x,y)dy(2)Independence of path of the various J-integrals is proved.(3)Computing formulae of J-integrals are derived.