Numerical solutions of generalized Burgers–Fisher and generalized Burgers–Huxley equations using collocation of cubic B-splines

In this work, we propose a numerical scheme to obtain approximate solutions of generalized Burgers–Fisher and Burgers–Huxley equations. The scheme is based on collocation of modified cubic B-spline functions and is applicable for a class of similar diffusion–convection–reaction equations. We use modified cubic B-spline functions for space variable and for its derivatives to obtain a system of first-order ordinary differential equations in time. We solve this system by using SSP-RK54 scheme. The stability of the method has been discussed and it is shown that the method is unconditionally stable. The approximate solutions have been computed without using any transformation or linearization. The proposed scheme needs less storage space and execution time. The test problems considered by the different researchers have been discussed to demonstrate the strength and utility of the proposed scheme. The computed numerical solutions are in good agreement with the exact solutions and competent with those available in the literature. The scheme is simple as well as computationally efficient. The scheme provides approximate solution not only at the grid points but also at any point in the solution range.     

Sadakichi artmann,essayist and critic

Abstract

During the last two years of his life, Ralph Eugene Meatyard assembled a series of photographs into a book titled The Family Album of Lucybelle Crater. The album's main subject is his wife Madelyn Meat yard who wore one mask for the title role of Lucybelle Crater, and appeared in sixtyfour photographs accompanied in each by a different person wearing one other mask. Madelyn Meat yard's mask, an opaque representation of a grotesque hag, is described as resembling ‘Mammy Yokum from Outer Space’.¹ The other mask is transformed by its wearer, for it is a translucent representation of an androgynous older person. Only two images are titled, and the real names of the masked people are revealed in a listing at the end of the book.     

一种低黏高切油基钻井液体系

针对传统油包水钻井液黏度高、切力低、携岩能力差的问题,合成了一种Gemini主乳化剂,其与辅乳化剂有较好的协同效应,钙皂分散性好,兼具润湿功能,在2.0%~3.5%的低加量下具有好的乳化能力。研制出了密度在1.0~2.0 g/cm3之间、抗温达170℃的低黏、高切油基钻井液。室内研究结果表明,该钻井液密度为1.00~1.70 g/cm3时,塑性黏度小于40 m Pa s,动塑比为0.35~0.50 Pa/m Pa s,具有低黏高切的特点;破乳电压在800 V以上;抗水达15%,抗钻屑达10%,并且润滑性能好,密度在2.0 g/cm3以下时润滑系数小于0.085。在焦页54-1HF井水平段的应用表明,该钻井液性能稳定,具有突出的低黏高切流变特性,破乳电压高,保证了施工顺利、井壁稳定、井眼通畅。     

Optimal policies for electromobility: Joint assessment of transport and electricity distribution costs in Norway

This paper develops a stylized economic model for passenger transport in the greater Oslo area, in which the agents' choices of car ownership, transport pattern, and electric vehicle (EV) charging are jointly determined. If enough EVs charge during peak hours, costly grid expansions may be needed. We examine how the distribution system operators can mitigate these costs with different pricing schemes and how this, in turn, affects the transport market equilibrium. We find that applying tariffs differentiated between peak and off-peak periods will help strike a better balance between grid investment costs and EV-owners’ disutility of charging during off-peak hours.     

石井和纮——新一代日本建筑师

石井和纮,极具个性色彩的建筑师,设计思维独特、新颖。作品最突出的特点就是“历史的借用”,以求创造出具有时代精神的日本化建筑。他不拘泥于日本的文脉,与世界上所有的历史和文化都保持等距离,创造出由传统的形态和构想发展而来的充满生气的建筑。     

工业无线局域网在料卷传输车上的实际应用

在长距离,非直线行走的运料小车控制通讯系统中,工业无线局域网具有其他有线通讯方式无法比拟的优势。在一些特殊环境下有效地弥补了有线网络的不足,方便灵活地利用移动节点或有线难以访问的节点进行控制信号的通讯。无线解决方案的主要优点就是移动站的简单性和灵活性,对目前传统的拖链式或微波管道式的小车通讯是一次比较大的突破,具有较好的应用推广价值。同时,工业无线局域网技术是基于IEEE802.11国际标准,拥有高达54Mbps的数据传输率,因此具有传输稳定可靠、访问安全性高、维护工作量少等优点。它随时、随地提供信息访问的能力,将在工业通讯市场发挥越来越大的作用。     

Electrical properties of ITO/benzylated cyclodextrins (-CDs (Bz))/Al diode structures

Investigations of the electrical characteristics of benzylated cyclodextrins (β-CDs (Bz)) diodes are reported. We present current–voltage characteristics and impedance spectroscopy measurements performed on partially benzylated cyclodextrins β-CDs (Bz) thin films in sandwich structures ITO/β-CDs (Bz)/Al. The static electrical characterizations show a space charge limited conduction (SCLC) and a conductivity with power low frequency behavior characteristic of a hopping transport in disordered materials. The impedance spectra can be discussed in terms of an equivalent circuit model designed as a parallel resistor R_P and capacitor C_P network in series with resistor R_S. We extract numerical values of these parameters by fitting experimental data. Their evolution with bias voltages has shown that the SCLC mechanism is characterized by an exponential trap distribution. We estimated from the capacitance voltage characteristic an acceptor concentration of about due to trap states.     

不同蛋白含量大豆品种氮代谢关键酶活性及叶片氮同化物含量变化

以高蛋白野生大豆、普通野生大豆和栽培大豆为材料,研究大豆籽粒蛋白质含量与各生育期叶片谷氨酰胺合成酶活性（GSA）、硝酸还原酶活性（NRA）以及叶片不同氮同化物含量之间的关系。结果表明：高蛋白野生大豆在V6期到R8期的NRA、R3期开始各个时期的GSA都明显高于其它品种。R3期以外的其它各生育期,高蛋白野生大豆可溶性蛋白含量高于其它品种。叶片游离氨基酸含量则表现为R2期之前野生大豆高于栽培大豆,R2期及以后各个时期又明显低于栽培大豆。籽粒蛋白质含量与R3期到R8期的NRA以及R3、R8期的GSA呈正相关关系。V3期可溶性蛋白质含量和V6期游离氨基酸含量与籽粒蛋白质含量呈正相关。叶片硝态氮含量与籽粒蛋白质含量没有相关性。     

一种工程中实用的WGS-84到BJ-54坐标系转换方法

在规划设计等工程应用中经常使用GPS卫星定位系统来确定现状及规划线路,得到的是以大地坐标系为基础的WGS-84坐标系数据,而目前规划设计项目中普遍使用的又是以1954年北京坐标系为基础的坐标数据,因此必须给出WGS-84坐标转换到BJ-54坐标系的转换方法,本文对这两种坐标系转换模型进行了分析,并给出了在AutoCAD工程设计中的一个实用LSP描点程序,通过工程实践,得到了很好的工程效果.