Study on divertor plasma behavior through sweeping strike point in new lower divertor on EAST

A series of L-mode discharges have been conducted in the new ‘corner slot’ divertor on the Experimental Advanced Superconducting Tokamak (EAST) to study the divertor plasma behavior through sweeping strike point. The plasma control system controls the strike point sweeping from the horizontal target to the vertical target through poloidal field coils, with keeping the main plasma stability. The surface temperature of the divertor target cools down as the strike point moves away, indicating that sweeping strike point mitigates the heat load. To avoid the negative effect of probe tip damage, a method based on sweeping strike point is used to get the normalized profile and study the decay length of particle and heat flux on the divertor target λ_js, λ_q. In the discharges with high radio-frequency (RF) heating power, electron temperature T_e is lower and λ_js is larger when the strike point locates on the horizontal target compared to the vertical target, probably due to the corner effect. In the Ohmic discharges, λ_js, λ_q are much larger compared to the discharges with high RF heating power, which may be attributed to lower edge T_e.     

每个忙期中第一个顾客被拒绝服务的M／M/1排队模型的其他特征值

研究每个忙期中第一个顾客被拒绝服务的M／M／1排队模型的主算子在左半复平面中的特征值,证明对一切θ∈（0,1）,（2√λμ-λ—μ）θ是该主算子的几何重数为1的特征值．     

茶叶定性和定量近红外光谱分析方法研究

分别采集了茉莉花茶、苦丁茶、龙井和铁观音4个种类茶叶共120个样本,利用NIRSystems6500型近红外光谱分析仪对样本进行光谱测量,应用近红外光谱分析技术对茶叶进行定性和定量分析.采用主成分分析法,结合聚类分析法,对4种类别的茶叶进行定性鉴别,通过对不同光谱数据预处理方式和不确定因子系数进行比较,确立了最优定性判别定标模型.同时,采用修正的偏最小二乘法,比较不同光谱预处理方法对定标模型的影响,建立了茶叶中水分、茶多酚和咖啡碱含量的定量分析模型,并对未知样本进行预测.定性分析模型的种类识别准确率达到100%,定量分析模犁的决定系数均大于0.91,相对分析误差RPD均大于3.结果表明,利用NIRS分析技术可以快速定性和定量分析鉴别茶叶的类别和成分含量.     

应用广义阶梯函数解变刚度超静定梁的弯曲问题

变刚度超静定梁的弯曲问题,可以近似的以受分段均布荷载(包括集中荷载、集中力偶)作用下的阶梯梁来代替.本文推广Heaviside函数{x-a}~0的概念,定义一个新的函数{x-a}~n,n=0,1,2…,称为广义阶梯函数,并给出{x-a}~n{x-b}~0的运算法则.然后将抗弯刚度的倒数1/EJ和弯矩方程M(x)都用{x-a}~n来表示.代入挠曲线近似微分方程,从而建立一套适用于各类直梁弯曲问题的统一解法,并给出一般情况下挠曲线方程的通式.     

阶梯形杆的临界载荷的截面优化设计

首先对阶梯形截面压杆导出一组适用于各种支承条件的决定临界载荷的方程。然后利用它在压杆体积保持为常量,并具有最高临界载荷的条件下对截面尺寸进行优化。讨论了满足条件I=CA~2的截面(包括实心的正方形和圆形截面等)以及空心圆截面。文中给出了一些结果,可供工程设计者参考。 为了避免解三角方程可能带来的困难,介绍了用最佳一致逼近原理将三角方程转换成代数方程的解法。     

Applying the Generalized Step-function to Solve the Bending Problems of Nonuniform Beams with Variable Cross Section

The bending problems of nonuniform beams with variable cross-sectioncan be approximated by that of a step beam under sectionally uniform load(including both concentrated forces and couples).In this paper,the conceptof Heaviside function{x-a}~0 will be generalized,and a new function{x-a}~n,n=0,1,2……,will be defined,which may be named as a generalized stepfunction.The rules of operation will also be given to{x-a}~n{x-b}~0.Thereciprocal of the flexural of rigidity1/EJ and the bending moment M(x)can all be expressed in terms of{x-a}~n,and substituted into the differentialequation of the elastic curve of the beam respectively.Thus we mayestablish a set of unified method to solve various types of bending problemsof straight beams.The general solution of the deflection equation will begiven.     

用2D NMR研究异戊烯类取代黄酮化合物的结构

借助2DNMR技术，研究并总结了10个含异戊烯类取代基的黄酮化合物的(13)CNMR谱，着重就取代基与黄酮骨架的连接点进行了探讨，认为C-8位和C-5’位异戊烯类取代基取代将直接影响C-8和C-5’位及周围碳的化学位移值，这一现象可以直接用于该类化合物的结构鉴定     

平均值原理

特称命题(也称存在命题) ■xP(x),即“至少有一个x满足性质P”有两种证法:一种是构造性的,即把满足性质P的对象x找出来;一种是非构造性的,即不找出那个对象,但利用某种原理证实这种对象是存在的。非构造     

关于光学制图法的国际标准概要

本文叙述了光学制图法的最新国际标准。包括光学零件的基本绘图方法以及光学材料的缺陷允差、球面面形误差、零件的中心偏差、球面疵病允差、表面粗糙度、表面处理和镀层等的表示方法。