Tracking Pre-service Teachers’ Changing Conceptions of Good Science Teaching: The Role of Progressive Reflection with the Same Video

A CD-ROM consisting of videos of two lessons by different teachers demonstrating exemplary science teaching was used to elicit, develop and track the changing conceptions of good science teaching of student teachers enrolled for the one-year Postgraduate Diploma in Education (PGDE) at several stages during the programme. It was found that the videos acted as an effective probe to elicit student teachers’ conceptions and had significant impact on those conceptions at different stages of the programme through the provision of teacher models demonstrating exemplary teaching. The experience has extended novice teachers’ awareness of alternative teaching methods and approaches not experienced in their own schooling, broadened their awareness of different classroom situations, provided proof of existence of good practices and prompted them to reflect on their current conceptions of good science teaching. Most importantly, the strategy of asking student teachers to watch the same videos on three separate occasions at different times of the course was recognized by them as a crucial element in facilitating their reflection on their changing conceptions of good science teaching. PGDE is the standard form of pre-service teacher education in Hong Kong. It provides qualified teacher status within Hong Kong. Student teachers enrolled for the PGDE have completed a relevant undergraduate degree.     

科学假说和艺术想象

科学和艺术是人类在社会发展过程中所创造的精神财富。表面上如此遥远的两大文化领域 ,却有着久远的亲缘关系 ,而且显示着共同的美感。这其中包括科学假说和艺术想象显示的空灵美。     

The impact of reading at rapid rates on inference generation

Aims

Speed reading is advertised as a way to increase reading speed without any loss in comprehension. However, research on speed reading has indicated that comprehension suffers as reading speed increases. We were specifically interested in how processes of inference generation were affected by speed reading.

Methods

We examined how reading speed influenced inference generation in typical readers, trained speed readers and participants trained to skim read passages. Passages either strongly or weakly promoted a bridging or predictive inference. After reading, participants performed a lexical decision task on either a nonword, neutral or inference‐related word.

Results

Typical readers responded to strong and weak inference words faster than neutral words. There were no statistical differences in reaction time between inference‐related and neutral words for speed and skim readers.

Conclusions

These findings provide no substantive evidence that the appropriate inferences are generated when reading at rapid speeds. Thus, speed reading may be detrimental to normal integrative comprehension processes.     

Successive reversals of a discriminated preference for signaled tailshock

Three rats received unmodifiable tailshock at random intervals in a shuttlebox. In a continuous-choice situation, Ss could choose between an auditory signal immediately preceding or immediately following the tailshock. Over repeated daily 3-h sessions, each S acquired a spatial discrimination indicating a strong preference for the signal preceding tailshock. This preference continued undiminished through two successive reversals of the position associated with signaled shock. This demonstration precludes explanations of the preference-for-signaled-shock phenomenon based upon primary reinforcement value or acquired value of the signal, position preferences, and overt modification of the aversiveness of the reinforcer through such means as postural adjustments. An explanation of recent failures to obtain the preference-for-signaled-shock effect is offered.     

Numerical investigation of cavitating flow behind the cone of a poppet valve in water hydraulic system

Computational Fluid Dynamics (CFD) simulations of cavitating flow through water hydraulic poppet valves were performed using advanced RNGk-epsilon turbulence model. The flow was turbulent, incompressible and unsteady, for Reynolds numbers greater than 43000. The working fluid was water, and the structure of the valve was simplified as a two dimensional axisymmetric geometrical model. Flow field visualization was numerically achieved. The effects of inlet velocity, outlet pressure, opening size as well as poppet angle on cavitation intensity in the poppet valve were numerically investigated. Experimental flow visualization was conducted to capture cavitation images near the orifice in the poppet valve with 30° poppet angle using high speed video camera. The binary cavitating flow field distribution obtained from digital processing of the original cavitation image showed a good agreement with the numerical result. Project supported by the National Natural Science Foundation of China (No. 59835160) and Scientific Research Foundation for Returned Overseas Chinese Scholars, State Education Ministry of China (No. 50175097)     

网络时代的高校思想政治教育工作的挑战与对策

网络技术的普及和发展,像一把双刃剑,给高校思想政治教育工作带来了机遇与挑战,它拓宽了高校思想政治工作的渠道,同时也引发许多问题,如何趋利避害进行网络思政教育是一个重要而迫切的课题.     

分布式技术在教材管理系统中的应用

本介绍了多层分布式结构的特点及采用分布式技术开发的高校教材管理系统。     

扰动的线性方程组通解的Huang算法

本文给出了求解扰动后新方程组的直接方法，它简捷，计算量和存贮量都不大，数值结果也表明它是相当有效的。对于替换多个方程的情况，用本方法均可直接处理。     

Do all roads really lead to Rome? The case of spelling acquisition

The French orthographic code is complex, and its acquisition is laborious (Catach, 2008; Fayol & Jaffré, 2008). Three hypotheses attempt to explain orthographic knowledge acquisition (OKA). For some, exposure to the code leads to OKA through a self-learning process (Share, 2004). For others, OKA benefits from graphophonological processes (Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001). Finally, some authors suggest that OKA is possible thanks to visual specific processes (Ans, Carbonnel, & Valdois, 1998). The main goal of this study was to test these hypotheses in a classroom context with comparable samples. In total, 143 2nd-grade children participated in this quasi-experimental study with a pretest, immediate posttest, and delayed posttest design. We assigned participants to one of four conditions. For three conditions, we created three teaching procedures based on each of the hypotheses: frequency of contacts with target words; explicit teaching of graphophonological properties of words; explicit teaching of visual properties of words. The fourth served as a control group. ANOVA analyses indicated that all three experimental conditions favored OKA, showing that the different teaching procedures led to spelling development. However, the visual condition was the most favorable. Three main conclusions can be drawn from this study: (a) models of OKA should account for the different paths that can lead to spelling acquisition; (b) visual properties of words and their acquisition need additional research, and (c) applied research in real classroom contexts is not only relevant for informing teaching practices but also for better understanding how learning takes place.

     

双壁钢围堰吸泥下沉、清基及水下封底过程中有关问题的处理办法

系统概述了介绍芜湖长江大桥11号主墩双壁钢围堰吸泥下沉、清基及水下封底过程和应注意的事项及有关问题的解决办法。