Novel high torque bearingless two-sided rotary ultrasonic motor

Applications are limited at present because the currently available ultrasonic motors (USMs) do not provide suffi-ciently high torque and power. The conventional travelling-wave USM needs the bearing to support, which required lubricant. To solve the above problem, a bearingless travelling-wave USM is designed. First, a novel structure of the two-sided USM consisting of a two-sided teeth stator and two disk-type rotors is designed. And the excitation principle of the two-sided travelling-wave USM is analyzed. Then, using ANSYS software, we set up the model of the stator to predict the excitation frequency and modal response of the stator. The shape of the vibration mode was obtained. Last, the load characteristics of the USM are measured using ex-perimental method. The maximum stall torque and the no-load speed were obtained. The results showed that the characteristics of the two-sided USM are better than those of the conventional one-sided USM.     

教科文组织视域中的国际理解教育课程

教科文组织为推动国际理解教育在各国的各级各类学校充分落实,不但发布了一系列规范性国际文书,而且组织专家制定了在学校课程中开发国际维度的指导方针和标准,从目标确定、内容选择和教学方式等方面提出了具体的要求和建议,为各国国际理解教育课程的设置和实施提供了依据和指导。     

GLABROUS INFLORESCENCE STEMS regulates trichome branching by genetically interacting with SIM in Arabidopsis

Arabidopsis trichomes are large branched single cells that protrude from the epidermis. The first morphological indication of trichome development is an increase in nuclear content resulting from an initial cycle of endoreduplication. Our previous study has shown that the C2H2 zinc finger protein GLABROUS INFLORESCENCE STEMS (GIS) is required for trichome initiation in the inflorescence organ and for trichome branching in response to gibberellic acid signaling, although GIS gene does not play a direct role in regulating trichome cell division. Here, we describe a novel role of GIS, controlling trichome cell division indirectly by interacting genetically with a key endoreduplication regulator SIAMESE (SIM). Our molecular and genetic studies have shown that GIS might indireclty control cell division and trichome branching by acting downstream of SIM. A loss of function mutation of SIM signficantly reduced the expression of GIS. Futhermore, the overexpression of GIS rescued the trichome cluster cell phenotypes of sim mutant. The gain or loss of function of GIS had no significant effect on the expression of SIM. These results suggest that GIS may play an indirect role in regulating trichome cell division by genetically interacting with SIM.     

我国高校工程训练中心的建设与发展

工程训练中心是在工科高校内实施工程实践教学的基础性平台,是中国高等教育改革发展中出现的一个新事物,近10年来得到快速发展。基于国家级工程训练示范中心的相关数据统计,对工程训练中心的发展历程及其建设现状进行了介绍和分析。     

“酮粉法”连续一年监测大群奶牛酮病试验简报

为探寻监测奶牛酮病的方法,试验用“酮粉法”快速检验酮病的效果,探讨安徽省奶牛酮病的发病规律,为防治本病提供科学依据,在一年时间内,连续对安徽合肥保健奶牛场和淮南奶牛一场、二场的泌乳母牛,进行了全面的,每月一次的监测。通过对近一万头次的监测发现,这几个场奶牛酮病的发病率在头年的十一月份到第二年的四月份发病率较高(平均为3.7%),其中二月份发病率最高(6.62%)。     

The curriculum potential of Darwin's Theory of Evolution

Unity and diversity are best reconciled by Darwin's Theory of Evolution. Two major dilemmas related to the study of Evolution are described. The first, concerning pedagogy, can be solved by teaching the topic at an elementary level in the middle school so that the Theory may serve as an advanced oragnizer and returning with in-depth study in the last two years of high school. The second, concerning Faith, is a sensitive issue. Some successful approaches are discussed. The place of Darwin's Theory in the all-elective high school biology curriculum is described as well. The role of the Theory regarding explanations is especially highlighted.     

Cooperative Learning and the Organization of Secondary Schools

This article describes the inter‐relationship between school organization and classroom instructional style. Two distinct models of school organization, the bureaucratic and open‐systems models, are characterized in terms of three major dimensions of school life; a. the behavior of administrators, teachers and students, b. work design and tasks, and c. space‐time allocations. It is shown that the bureaucratic model of school organization parallels, and sustains, the traditional whole‐class method of teaching in all of the three dimensions. An open‐systems model of staff organization at the school level is required to sustain an alternative form of classroom instruction such as cooperative learning. The approach presented here emphasizes the inter‐relatedness of all three dimensions of schooling at the organizational and classroom levels. It also claims that the implementation of genuine instructional change, that entails new patterns of interpersonal relations in the classroom, is contingent upon similar changes being made at the level of the school as an organization. Lack of attention to school organizational change may explain why efforts at changing instruction at the classroom level frequently fail to yield results.     

Scaling-up Sustainable Land Management Practices through the Concept of the Rural Resource Centre: Reconciling Farmers' Interests with Research Agendas

Abstract

Purpose: Formal agricultural research has generated vast amount of knowledge and fundamental insights on land management, but their low adoption has been attributed to the use of public extension approach. This research aims to address whether and how full participation of farmers through the concept of Rural Resource Centre (RRC) provides new insights for the development of alternative and farmers-based extension methods.

Design/Methodology/Approach: Using the Concept of RRC, this research assesses the role of farmers in on-farm demonstrations and scaling-up of land management practices, and investigates effective ways to enhance beneficial interactions between researchers, extension workers and farmers in view of improving adoption.

Findings: The findings suggest that farmers can effectively participate in demonstrations and scaling-up of agricultural practices. This participation is enhanced by judicious incentives such as higher crop yields that motivate farmers and influence adoption. The current success of the approach stems from the fact that farmers, extension workers and researchers jointly implement the activities and their different aims were achieved simultaneously: scientific results for researchers, better agricultural practices for extension workers, and economic success and free choice for farmers.

Practical implications: This research concludes that farmers have the capacities to play an innermost role in demonstrations and scaling-up of agricultural practices. However, there is a need to build and strengthen their capacities to facilitate their participation and contribution.

Originality/Value: The article demonstrates the value of the preponderant role of farmers in on-farm demonstrations and scaling-up practices by exhibiting the beneficial interactions between researchers, extension workers and farmers.     

A customised Total Quality Management Framework for schools

Abstract

Research has revealed that many of the historically disadvantaged schools in South Africa experience difficulty in implementing policies aimed at restoring the quality of teaching and learning. The difficulty has been attributed to several factors such as poor conceptualisation and implementation of quality management systems at school level. This article reports on empirical research that investigated the possibility of applying Total Quality Management principles in schools for the purpose of restoring the culture of learning and teaching. Data was collected through qualitative and quantitative methods in selected schools situated in the Tshwane North District. The findings revealed that there is a gap between what is provided in the policy framework on the management of quality teaching and learning. It is recommended that in order to fill the gap, schools need to apply customised principles of Total Quality Management. The primary aim of this research was to develop such an integrated framework that is not only theoretically sound but that has been customised for schools’ contexts and conditions.