用于再生伪码测距时钟恢复的新型码片跟踪环性能分析

为了提高低信噪比条件下再生伪码测距系统中的复合伪码时钟恢复性能,采用了一种新型的码片跟踪环.此码片跟踪环是一种改进型的数据转换跟踪环,两者之间的区别在于,码片跟踪环的Q路输出直接乘上了时钟分量,而数据转换跟踪环乘上了I路的转换检测器输出.在准方波伪码测距信号的情况下,详细分析了码片跟踪环的跟踪(均方定时抖动)性能.分析对比了不同码片信噪比条件下的码片跟踪环和数据转换跟踪环跟踪性能.分析表明,码片跟踪环和数据转换跟踪环在大信噪比条件下性能一致;而在小信噪比条件下,码片跟踪环性能明显好于数据转换跟踪环.     

0.9Pb(Sc_(0.5)Ta_(0.5))O_3-0.1PbTiO_3/PbTiO_3多层薄膜制备及铁电性研究

以LaNiO3做缓冲层,用射频磁控溅射法在SiO2/Si(100)衬底上制备出0.9Pb(Sc0.5Ta0.5)O3-0.1PbTiO3/PbTiO3铁电多层薄膜.采用两步法在峰值温度750℃对薄膜进行退火.通过电滞回线和漏电流曲线对薄膜的铁电性能进行了测量.研究发现,原位生长的薄膜已经具备了较好的铁电性,这为(1-x)Pb(Sc0.5Ta0.5)O3-x0.1PbTiO3薄膜的低温制备提供了可能性.经过退火后,薄膜的铁电性略有下降,高温下铅的损失可以很好的解释这一现象.     

Feedback loops and the longer-term: towards feedback spirals

A key challenge for feedback practice involves promoting student uptake through the closing of feedback loops. This paper investigates feedback loops by using the concepts of single and double-loop learning to interrogate student responses to feedback. Single-loop learning tackles an identified problem or task, whereas double-loop learning additionally re-evaluates how the problem or task is approached. Evidence from a five-year longitudinal enquiry into four undergraduate students’ experiences of feedback is used to analyse feedback loops. Students reported a variety of experiences: failing to engage significantly with end-of-semester comments; short-term uptake within modules which had two assignments; and longer-term efforts at improving their learning strategies. A model of long-term student engagement with feedback is proposed, including single-loop feedback processes, double-loop feedback processes and unresolved learning puzzles. Whereas feedback loops are mainly focused on the shorter-term, it is suggested that feedback spirals represent an alternative way of analysing complex, iterative longer-term learning processes. Implications for practice focus on student self-regulation and the development of student feedback literacy.     

一种新的闭合环自动搜索算法

在测量控制网数据自动化处理过程中,搜索闭合环是平差程序设计首先要解决的问题.探讨最小独立闭合环自动搜索的一种新算法——"余枝搜索法",并提出"正向搜索,反向提取"的方法来解决在搜索时不易记录路线的问题.基于MATLAB编写闭合环自动搜索的函数,经过实践验证,该算法切实可行.     

6岁儿童的类别学习能力: 类别表征、注意和分类策略

在实验室条件下对人类的学习进行心理学研究,通常的做法是在一定时间内让被试习得一项新的世界知识,因此类别学习成了主要的任务范式,一直是认知心理学最热点的研究领域之一。首先,梳理了类别学习的认知和神经研究;然后,分析了皮质—纹状体回路与类别学习的关系,进而提出类别学习的神经机制是以基底核为纽带,皮质—纹状体的四条回路为实现途径的理论设想;最后,讨论了如何从学习条件、学习过程和学习结果三方面去探讨类别学习的认知神经机制。     

对短跑运动员手掌纹、指纹的调查研究

通过对安徽省107名(男64人、女43人)短跑运动员、安徽师大体院200名学生(男100人、女100人)及安徽师大公共系200名学生(男100名、女100名)的手掌、指纹进行调查研究，短跑运动员的手掌、指纹指标与普通组间有若干统计学差异，这些手掌、指纹特征可为短跑运动员选材提供参考指标。     

A multi-study examination of intra-individual feedback loops between competence and value beliefs,procrastination, and goal achievement

In the present study, we tested intra-individual feedback loops between competence beliefs, value beliefs, and goal achievement (virtuous circles), and intra-individual feedback loops between goal failure and procrastination (vicious circle). We analyzed data from five independent intensive longitudinal studies with university students (N = 841, k = 23,448 observations). Pre-registered hypotheses were tested across the five studies and aggregated using meta-analytic methods. Results provided support for virtuous circles in self-regulated learning: Students who reported higher competence and value beliefs in one study session reported higher goal achievement, and higher goal achievement predicted higher competence and value beliefs in the subsequent study session. Results provided only partial support for a vicious circle: Procrastination was associated with lower goal achievement but goal achievement did not predict subsequent procrastination. The results have theoretical implications for models of self-regulated learning and methodological implications for the design of experience sampling studies.     

Multilingual students’ use of translanguaging in science classrooms

ABSTRACT

This study describes multilingual students’ authentic use of their first and second languages in a translanguaging science classroom, from a sociocultural perspective. The study is ethnographic, and has followed some lessons each month in a translanguaging science classroom at a primary school for three years. The observed lessons were documented by four video cameras and four audio recorders, while field notes and different types of students’ texts and other teaching materials were also collected. In order investigate how language operates, and to realise the meaning semantically, we analysed the students’ use of both first and second language to tie paradigmatic relations, and how they move in linguistic loops between languages and discourses. The results illustrate the ways in which a translanguaging science classroom constitutes a resource in joint negotiations of the scientific content and its related language for multilingual students, and benefits the students’ ability to relate and contextualise the science content to prior experience. The creation of translanguaging science classrooms, in which students’ experiences and diverse cultural and linguistic resources interweave with school science, and in which multilingual students are enabled and encouraged to use all available language resources, has important implications for science education.     

MOORE353 复杂批量控制程序开发应用

MOORE353智能调节器具有强大的控制功能,在现代企业中应用广泛.阐述了使用MOORE353进行复杂批量程序的编程组态方式和结构,以及MOORE353回路的分配等问题.经过编程组态,MOORE353能进行反馈回路控制和复杂的批量生产过程控制,减轻了的劳动强度,提高了操作可靠性.开发的控制方案适于在中、小型的生产装置中大量推广.