4种小肽衍生物的非水毛细管电泳分离研究

以咔唑-9-乙基氯甲酸酯为柱前衍生试剂,采用非水毛细管电泳对衍生小肽进行分离.以甲醇和乙腈为溶剂,乙酸-乙酸铵为缓冲体系,采用235 nm二极管阵列检测.在甲醇与乙腈体积比为60 ∶ 40,乙酸铵浓度60 mmol/L,乙酸浓度0.8 mol/L,柱温20 ℃,分离电压30 kV条件下,实现了4种小肽衍生物的基线分离.     

Experimental investigation of loss and gain characteristics of an abnormal In_xGa_(1-x)As/GaAs quantum well structure

In this Letter, the loss and gain characteristics of an unconventional InxGa1-xAs∕Ga As asymmetrical step well structure consisting of variable indium contents of InxGa1-xAs materials are measured and analyzed for the first time, to the best of our knowledge. This special well structure is formed based on the indium-rich effect from the material growth process. The loss and gain are obtained by optical pumping and photoluminescence(PL)spectrum measurement at dual facets of an edge-emitting device. Unlike conventional quasi-rectangle wells, the asymmetrical step well may lead to a hybrid strain configuration containing both compressive and tensile strains and, thus, special loss and gain characteristics. The results will be very helpful in the development of multiple wavelength In Ga As-based semiconductor lasers.     

变式课本例题 考查思维能力

中考压轴题考什么?是初三学生、教师及家长普遍关心的问题.数学是学思维、用思维的学科,中考题理应考查学生的思维能力.现     

一种有效解决离轴数字全息相图倾斜畸变的数字参考平面方法

离轴数字全息中使用倾斜的平面参考波以消除成像中的零级衍射和共轭像是一种简捷和常用的方法,然而该方法遇到的一个困扰是,由于倾斜参考波引入了附加的载波频率并很难通过实验测量准确地获得附加的载波频率值或倾角,因此会导致重建的相图出现一定的倾斜畸变而无法完全修正.本文提出了一种数字参考平面算法以解决这一问题.该算法利用重建相图的平坦区域选点构建一个能准确表征相图倾斜的数字参考平面,并建立该平面参量与参考波载波频率的数学关系和作为随后相图畸变修正迭代计算的判据.该算法简单有效,不仅能实现对倾斜相位畸变的准确修正,而且能准确地获得倾斜平面参考波的附加载波频率.由于在相位解包裹重建中结合了抑噪处理,因此该方法在环境和系统噪声的影响下仍然有效,实验结果验证了理论设计的有效性.