Bar code recognition is a matter of edge detection , which has long been done through the maximum value of the first derivative or zero crossing of the second derivative 条码识别是一个边缘检测问题。长期以来，边缘检测都是通过一阶导数极大值或二阶导数零交叉进行的。
Combining principal factors scores , a * and first derivative of 555nm reflectance , we discussed modem sediment environment in shelf of the yellow sea and east china sea 结合主因子得分、 a ~ *和re555nm一阶导数的分布，讨论了黄海、东海陆架的现代沉积环境(氧化还原环境) 。
Pls algorithm was applied in the establishment of analytical models showing the relationships between the 2nd derivatives of nir spectra with the contents of the respective components mentioned above 用pls计算法建立了表示上述组分的二阶导数近红外光谱与其含量间关系的分析模型。
The symmetrical part uses the source distribution on the center plane of the body whereas the asymmetrical part is achieved through the doublet distribution on the camber surface 求解完毕得到速度势后，对其求一阶导数得到物面上的速度分布，进而通过伯努利方程求出物面上的压力分布。
In view of theproperties of infrared thermal images , narrow - range zero - crossing edge detection method was applied to detect the edges of welding flaws and good results were obtained 针对红外热图象的灰度特性，提出了窄范围二阶导数过零边缘检测用于焊接缺陷的边缘提取，获得了较好的效果。
Mostly , traditional arithmetic of image edge detection distill edge using gradient maximum or zero - crossing which base on gray discontinuousness on edge . they are affected easily by noise 传统的边缘检测算子大都是基于边缘的灰度不连续性利用梯度局部最大值或二阶导数过零点来检测边缘，容易受噪声干扰。
An existence theorem of solution is established for a class of fourth - ordet two - point boundary value problems with all order derivatives by using integral equation and considering the " height " of nonlinear term 摘要通过运用积分方程并考察非线性项的“高度”对一类含有各阶导数的四阶两点边值问题建立了一个解的存在定理。
The theory on well - posedness and regularity of solutions to such class of degenerate problems , plays a crucial role in the above fields . anyway , such equations are deserved to be investigated vastly 进而通过解常微分方程，可以得到弱解关于退化方向的一阶导数的一种积分表达式，从而在两种不同情形下建立了两个基本引理。
Thirdly , the effects on the cv rational interpolating splines from the perturbation of the two boundary conditions are analyzed . from this the error bounds of first and second derivatives of cv rational interpolating spline are given 然后,分析了两类端点条件的扰动对cv有理插值样条函数的影响,给出了它们在非均匀节点处的一阶和二阶导数值的误差界
The solution was divided two portios and equal dilution with 2ml of 0 . 45mol / l naoh and 2ml 0 . 6mol / l kc1 - h3bo3 buffer obtained ph14 and ph10 solution respectively . the 2nd derivative spectrum of ph14 solution was measurement with phio solution as reference solution Oml0石mol l氯化钾一硼酸缓冲溶液制成ph14及ph10的溶液，以ph10的溶液为参比，测定ph14溶液的二阶导数光谱图。
