Land degradation,government subsidy,and smallholders’ conservation decision: the case of the loess plateau in China

Land degradation is one of the severe environmental problems in China. In order to combat land degradation, a soil conservation program was introduced since 2000 to reduce soil erosion by converting slope-cultivated land into forestry and pasture. This paper represents the first systematic attempt to investigate the impact of the soil conservation program on land degradation in the loess plateau. The results indicate that the soil conservation program to convert slope fields into forest or pasture is an effective way to combat soil erosion. However, a subsidy that is higher than profit of land use activity of slope fields before their conversion into forest and pasture is needed to encourage farmers to join the conservation program. A policy measure to encourage and assist farmers to develop sedentary livestock by using crops produced from fields as well as fodder and forage grass from the converted slope fields might contribute to combat soil erosion. Increase in off-farm job opportunities may encourage households to reduce cultivation in slope fields. That implies a policy measure to encourage rural urbanization might contribute to combat soil erosion.     

浅谈对《MATLAB程序设计》课程基础教学内容的思考

本文简要介绍了MATLAB软件和《MATLAB程序设计》课程,结合笔者的教学实践,对程序设计的重要性给出了自己的认识,最后从四个方面对《MATLAB程序设计》课程的基础教学内容进行了探讨,并且给出了自己提高学生程序设计的途径。     

关于矩阵特征值有关性质的探讨——线性代数教学思考

矩阵的特征值和特征向量是线性代数课程的重要内容,它们不仅在矩阵的可对角化问题中起着关键的作用,也在概率统计、物理、工程、经济学等领域有广泛应用。本文主要探讨矩阵的特征值的有关性质,希望能引发读者的思考,并对线性代数的教学起到一定的作用。     

双线性系统的含义及其特性

介绍了双线性系统的几类表达式，列举双线性系统在实际问题中的几个典型例子，提出双线性系统的几个特性，最后简要介绍双线性系统的研究概况．     

由Kuhn-Tucker条件看线性规划的对偶问题

利用非线性规划的kuhn-Tucker条件给对偶线性规划一个统一简洁的定义，并给出线性规划与其对偶线性规划的变量和Kuhn-Tucker乘子的完整关系。     

DELPHI串行通信编程技术与实现

介绍了基于DELPHI环境的多种串行通信编程方法及编程技术,着重讨论了采用MSComm控件实现串行通信的基本方法、技巧,并探讨了微机与多单片机系统间实时远程通信的编程实现。     

Compatibility and Complementarity of Classroom Ecology and Didactique Research Perspectives in Physical Education

ABSTRACT

A large diversity of theoretical frameworks exists in the physical education literature. This article focuses on two of those frameworks to examine their compatibility and their complementarity. The classroom ecology paradigm concentrates on the balance between three task systems, two vectors, and programs of actions proposed by the physical education teacher and negotiated by students. The didactique research program studies the teaching and learning processes using the concepts of didactic contract and didactic milieu that focus on how the knowledge content emerges within teacher and students’ joint action. The article underlines the complementarity and the compatibility of the two frameworks when analyzing teaching and learning in physical education. It argues that the gray areas left by the classroom ecology paradigm could be filled with the insights of the didactique research program. A concise example of how the two frameworks have already been utilized is presented.     

G90和G91在自动编程换刀中的应用

在应用CAM软件的自动编程中，G90和G91在自动换刀时，刀具运行轨迹对加工工件会产生不同影响。调整程序段中的相关语句，可避免换刀时发生的撞刀现象。     

传递闭包的Matlab实现

在Warshall算法基础上,基于Matlab软件,编写出求传递闭包的计算程序,并得到了新添加的序偶矩阵。     

加强应用型人才的培养——浅谈装潢艺术专业的人才培养

装潢艺术专业在职业技能方面应侧重专业基本能力和核心能力的培养，在教学内容方面更应侧重职业基础和职业技术知识的综合运用。要注重培养学生的制作、展示、设计等方面动手操作能力和图形设计软件的实际应用能力，培养具有一定理论知识和较强实践能力的高素质、技能型的装潢行业的专门人才。