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This paper reports on the development of constructive EAP CALL courseware, and its integration into blended learning contexts, as a solution to the problems in EAP courses in Chinese universities. A case study of a defining skills package, developed for undergraduates at the University of Science and Technology Beijing (USTB), is used to illustrate the design and integration of the courseware. Guided by constructivist learning theory, the design draws on a synthesis of language-centered, academic skills-centered, content-based and task-based approaches. The integration is evaluated through the quality of students' written work and evidence of their satisfaction with their defining skills improvement and the CALL courseware, based upon the data from a questionnaire survey. Web-based digital tools and multimodal media have been exploited to devise and produce CALL materials on defining skills. After three weeks of blended learning, students' learning outcomes and satisfaction with the courseware and its integration were significantly positive.

This article reports the design of a course blended through a small private online course in a Chinese university EFL context, with an emphasis on the blended learning environment created thereby and on learners' perceptions of their blended learning. In a survey-based approach, 1603 students' experiences of blended EFL learning in two consecutive terms were examined. The questionnaire survey focused on the participants' perceptions of their engagement with blended learning, their motivation, learning autonomy and overall satisfaction. An analysis of students' responses reveals that the blended design can create an efficient EFL learning environment and gain positive learner perceptions.

The ultra-long gravity heat pipe has a long heat transfer distance and narrow working fluid flow channel within its tube. Due to these unique design features, the vapor–liquid counter-flow and heat transfer characteristics of these heat pipes are more complex than those found in conventional-size heat pipes. This paper innovatively proposes the design of a segmented visualization window structure of an ultra-long gravity heat pipe, which successfully overcomes the challenge of visualizing the internal flow during operations. A visualization experimental platform, measuring 40 m in height with an inner diameter of 7 mm and the aspect ratio up to 5714, was built to investigate the evolving characteristics of two-phase flows with an increasing heat input and the impact of the phase change flow characteristics on the thermal performance of ultra-long gravity heat pipes. The results obtained can provide guidance for the development of the internal structure of ultra-long gravity heat pipes that are being applied in exploiting geothermal energy. The results show that, at low heat input (200 W, 250 W), there are separate flow paths between the condensate return and the steam, but the high hydrostatic pressure due to the height of the liquid injection results in the presence of an unsaturated working fluid with a higher temperature in the liquid pool area, which has a lower evaporation rate, limiting the heat transfer through the heat pipe. It is found that if increasing the heat input up to 300 W, the evaporative phase change in the heating section becomes intense and stable. At the same time, despite the intermittent formation of liquid columns in the adiabatic section due to the vapor–liquid rolls, which increases the resistance to the vapor–liquid counter-flow, the liquid columns are blocked for a short period of time, and the path of steam rises and the condensate return is smooth, which does not seriously affect the steam condensation and liquid return evaporation. At this point, the overall temperature of the heat pipe is evenly distributed along the tube and the heat transfer performance is optimal. When the heat input further increases (350 W, 400 W), a large amount of condensate is trapped in the upper part of the adiabatic section and the condensing section by long liquid plugs for a long time. At this point, the condensate flow back to the heating section is significantly reduced, and the steam is seriously prevented from entering the condensation section, resulting in a significant increase in the temperature gradient between the lower part of the evaporating section and the upper part of the adiabatic section and deterioration of the heat transfer performance. [ABSTRACT FROM AUTHOR]