Mode transition process in a typical strut-based scramjet combustor based on a parametric study

The combustion performance of hydrogen fuel in a scramjet combustor has been a popular focus for scholars all over the world. In this study, the influence of the jet-to-crossflow pressure ratio on combustion performance in a scramjet combustor was investigated numerically, and the influence of a wall-mounted cavity was evaluated. The simulations were conducted using the Reynolds-averaged Navier-Stokes (RANS) equations coupled with the renormalization group (RNG) k-ε turbulence model and the single-step chemical reaction mechanism. This numerical approach was validated by comparing predicted results with published experimental shadowgraphs and velocity and temperature measurements. When the pressure of the wall-injector increases, the performance of the combustor decreases. At the same inflow condition, this may lead to a scram-to-ram mode transition. The cavity adopted in this study would prevent pre-combustion shock waves from pushing out of the isolator and help to stabilize the flow field, but it would decrease the mixing and combustion efficiencies.     

Using concept mapping to improve poor readers’ understanding of expository text

The present study examined whether the use of concept mapping is more effective in teaching expository material in comparison to a traditional, lecture only, approach. Its objective was threefold. First, to determine if multimedia concept mapping produces differential learning outcomes compared to digital text-based concept mapping. Secondly, to compare the above experimental approaches to traditional teaching and finally to demonstrate if there are significant differences in the level of satisfaction reported by children under the three instructional approaches used. Thirty fifth grade children participated from which three groups of poor readers were formed, matched on age, gender and reading ability. The two experimental groups were taught with the use of digital text-based and multimedia concept maps respectively and the control group was subjected to the traditional teaching method of expository material. Each group had three sessions of instruction on three different expository texts. The results indicated that concept mapping can be an effective means for teaching expository content. However, there were no differential learning outcomes when adding multimedia elements to concept maps. Moderate satisfaction was reported for all three approaches. The findings coincide with the body of literature emphasizing the importance of concept mapping in the learning and instruction of children with reading difficulties. The study’s results inform potential educators on the use of multimedia with poor readers in elementary school.     

Differentiating the Sources of Taiwanese High School Students’ Multidimensional Science Learning Self-Efficacy: An Examination of Gender Differences

The main purpose of this study was to investigate Taiwanese high school students’ multi-dimensional self-efficacy and its sources in the domain of science. Two instruments, Sources of Science Learning Self-Efficacy (SSLSE) and Science Learning Self-Efficacy (SLSE), were used. By means of correlation and regression analyses, the relationships between students’ science learning self-efficacy and the sources of their science learning self-efficacy were examined. The findings revealed that the four sources of the students’ self-efficacy were found to play significant roles in their science learning self-efficacy. By and large, Mastery Experience and Vicarious Experience were found to be the two salient influencing sources. Several gender differences were also revealed. For example, the female students regarded Social Persuasion as the most influential source in the “Science Communication” dimension, while the male students considered Vicarious Experience as the main efficacy source. Physiological and Affective States, in particular, was a crucial antecedent of the female students’ various SLSE dimensions, including “Conceptual Understanding,” “Higher-Order Cognitive Skills,” and “Science Communication.” In addition, the variations between male and female students’ responses to both instruments were also unraveled. The results suggest that, first, the male students perceived themselves as having more mastery experience, vicarious experience and social persuasion than their female counterparts. Meanwhile, the female students experienced more negative emotional arousal than the male students. Additionally, the male students were more self-efficacious than the females in the five SLSE dimensions of “Conceptual Understanding,” “Higher-Order Cognitive Skills,” “Practical Work,” “Everyday Application,” and “Science Communication.”     

A note on the Marcinkiewicz integral operators on Fp^a,q

In this paper, we shall prove that the Marcinkiewicz integral operator #n, when its kernel Ω satisfies the L^1-Dini condition, is bounded on the Triehel-Lizorkin spaces. It is well known that the Triehel-Lizorkin spaces are generalizations of many familiar spaces such as the Lehesgue spaces and the Soholev spaces. Therefore, our result extends many known theorems on the Marcinkiewicz integral operator. Our method is to regard the Marcinkiewicz integral operator as a vector valued singular integral. We also use another characterization of the Triehel-Lizorkin space which makes our approach more clear.     

产学研合作的治理机制设计

机会主义行为阻碍产学研合作创新效率的提高。通过对产学研合作创新的博弈分析,指出博弈的平衡预算约束与专用性资产所产生的可占用性准租是机会主义行为出现的两个根本原因;并进一步指出,通过引入第三方实施竞争性团体奖励及引入第三方参与人的关联博弈,可以有效抑制机会主义行为。     

Towards achieving the Sustainable Development Goals: Revisiting language of instruction in Tanzanian secondary schools

Research has been conducted on the detrimental effects of using a foreign language for learning in Tanzania’s secondary schools. While most studies recommend the use of a familiar language for instruction, the use of a foreign language in secondary education in Tanzania has been maintained. This has many consequences on the quality of education, and contributes to student dropout. Presenting a study carried out in the semi-rural areas of Dar es Salaam region in Tanzania, this article examines the extent to which language of instruction (LOI) contributes to school dropout. It postulates that the use of a foreign language for teaching and learning in Tanzanian secondary schools hinders the achievement of the United Nations’ Sustainable Development Goals (SDGs). The study’s findings, drawn from exploratory and qualitative narrative research, indicate that, notwithstanding the presence of several other factors, the use of a foreign language as LOI is a major contributor to student dropout. The use of an unfamiliar language of instruction contributes to students’ lack of interest in and disengagement from learning, which ultimately pushes them out of the school system. This is because students usually perform poorly when an unfamiliar language is used as the language of examination and in classroom interaction. The study also reveals that the voices of both teachers and students are not in consonance with what would be expected in an ideal classroom teaching and learning environment. Student dropout from secondary education caused by an inappropriate LOI leads to myriad further problems which, in turn, negatively affect realisation of the SDGs in Tanzania. This article, therefore, concludes that LOI needs to be strongly factored into the development agenda. In order to ensure equitable access to quality secondary education, as required by SDG 4, the Government of Tanzania needs to adopt a language policy that promotes effective teaching and equal access to quality education in secondary schools.     

对体院“特形生”学习竞技体操动作技术状况的研究

以问卷调查、专家咨询以及对反馈数据进行等级相关处理为主要研究方法,论述了学习体操动作技术的困难与学生所从事的专项练习之间的关系、“特形生”学习体操技术的障碍、“特形生”学习体操技术的态度等问题。     

海图三维离散数据分时检索算法

介绍了海图三维离散数据的分时检索算法，从而在数值变化能被及时检索到的前提下，大大节省了检索时间。     

快乐体育思想与女生体育教学

由于众所周知的原因,女生体育教学从形式到效果都不及男生,体育对女大学生的影响力十分有限,其中既有女性身体的客观因素,也有教学活动主体的主观问题.研究证明,注重兴趣的快乐体育是提高女生体育课教学效果的良方.     

外语课堂教学互动中教师的中介作用

本文重点探讨了以"学生为中心"的课堂交互活动中教师的中介作用以及实现中介作用的具体方法,对新的教育理念下教师的角色转变进行了阐释。