PCL一839卡在FDM位置控制系统的应用研究

概述了FDM位置控制系统和PCL一839卡的特点,并详细介绍了如何在FDM位置控制系统中应用PCL一839卡,包括硬件连接和软件的设计。     

发展特色鲜明的一般本科院校信息与计算科学专业——以成都信息工程学院为例

成都信息工程学院信息与计算科学专业结合培养目标和社会实际需求,在专业定位上,突出＂数学基础扎实,理工融合＂的特色;在课程设置上,合理设置专业必修课程,优化选修课程,调整理论教学与实验教学的比例,对课程进行模块化设计;在专业实践教学上,建立＂课内实验—课内实验与课外实践—课外实践—综合实践＂的多层次、逐步递进的阶梯型实践教学体系。实践表明,找准专业定位,明确专业办学特色对办好本专业起到至关重要的作用。     

学前师范类高职高专化学教学困境与对策探讨

学前师范教育专注于培养幼儿教师,使幼儿教师能够通过不同的方法、实物,系统化地对幼儿进行教育。高等职业教育学院和高等专科学科教育的师范类专业,是培养实用型幼教人才的重要基地。在培养幼儿教师的各类课程中,化学是非常重要的一门课程,高职高专应重视对化学教师的教育改革问题。本文对学前师范类高职高专化学教育的困境提出合理建议,为其未来发展寻求新的出路。     

Development of a space cold atom clock

Atomic clocks with cold atoms play important roles in the field of fundamental physics as well as primary frequency standards. Operating such cold atom clocks in space paves the way for further exploration in fundamental physics, for example dark matter and general relativity. We developed a space cold atom clock (SCAC), which was launched into orbit with the Space Lab TG-2 in 2016. Before it deorbited with TG-2 in 2019, the SCAC had been working continuously for almost 3 years. During the period in orbit, many scientific experiments and engineering tests were performed. In this article, we summarize the principle, development and in-orbit results. These works provide the basis for construction of a space-borne time-frequency system in deep space.     

On the Performance of Semi- and Nonparametric Item Response Functions in Computer Adaptive Tests

Large-scale assessments often use a computer adaptive test (CAT) for selection of items and for scoring respondents. Such tests often assume a parametric form for the relationship between item responses and the underlying construct. Although semi- and nonparametric response functions could be used, there is scant research on their performance in a CAT. In this work, we compare parametric response functions versus those estimated using kernel smoothing and a logistic function of a monotonic polynomial. Monotonic polynomial items can be used with traditional CAT item selection algorithms that use analytical derivatives. We compared these approaches in CAT simulations with a variety of item selection algorithms. Our simulations also varied the features of the calibration and item pool: sample size, the presence of missing data, and the percentage of nonstandard items. In general, the results support the use of semi- and nonparametric item response functions in a CAT.     

现代城市管理若干理论述评

近年来国内外影响较大的现代城市管理理论有:生态城市管理理论,新城市主义管理理论,城市营销理论,经营城市理论,城市竞争力理论和数字城市理论等等。现代城市管理论的繁荣促进了城市管理科学向更深层次、更高层次的发展,但是仍然有许多不足。当代城市管理,尤其是我国的城市管理,理论研究有余,而实证研究不足。未来,城市管理的研究必将呈现进一步综合化、系统化的趋势。     

集训对舞龙队女大学生血常规及内皮祖细胞的影响

目的:分析舞龙运动对女大学生血常规及内皮祖细胞含量的影响。方法:选取2017级舞龙队女大学生10人为训练组,2017级普通女大学生10人作为对照组。舞龙队女大学生备战比赛进行连续4周,每周3次,每次90min的赛前集训,普通女大学生除日常活动外,没有额外进行任何其他运动队的集训。集训结束后,在受试者都处于空腹状态下对两组受试者进行静脉采血并进行血常规、早期内皮祖细胞和晚期内皮祖细胞的检测。所得数据进行统计学分析。结果:参加舞龙集训的女大学生的血常规指标与普通女大学生的血常规指标无显著差异,早期EPCs和晚期EPCs无显著性差异,但在数值上显示出不同的趋势。结论:参加舞龙集训的女大学生身体处于健康状态。参加舞龙集训有可能增强运动员血管的自我修复能力。     

长治学院大学生乒乓球爱好者消费的现状研究

随着1890年乒乓球运动的诞生,乒乓球的普及范围和程度越来越高,它是一项全身型体育运动项目,具有极大的锻炼价值。培养思维操作能力、增强智力、培养心理素质、治疗近视等这些优势已成为长治学院大学生乒乓球爱好者选择这一运动的主要因素,近年来乒乓球在各大高校发展日益壮大,乒乓球运动越来越受欢迎,一是让学生掌握乒乓球锻炼的技能和方法;二是增强体质、增进健康,体验乐趣;除此之外,乒乓球技术的灵活性与多样性,让大学生的课外学习生活变得更加具有趣味性。为了更好的使乒乓球运动的开设在高校得到普及,让更多的乒乓球爱好者参与其中。本文主要采用文献资料法、问卷调查法、访谈法、数理统计法、逻辑分析法,对长治学院大学生乒乓球爱好者消费的现状进行了相关研究。     

我国高等职业教育的发展战略研究

本文分析了我国高等职业教育发展中取得的主要成就和存在的主要问题,提出了我国高等职业教育在今后一个时期内的总体发展目标,和加快发展高等职业教育的战略措施与保障条件。     

Molecular design revitalizes the low-cost PTV-polymer for highly efficient organic solar cells

Developing photovoltaic materials with simple chemical structures and easy synthesis still remains a major challenge in the industrialization process of organic solar cells (OSCs). Herein, an ester substituted poly(thiophene vinylene) derivative, PTVT-T, was designed and synthesized in very few steps by adopting commercially available raw materials. The ester groups on the thiophene units enable PTVT-T to have a planar and stable conformation. Moreover, PTVT-T presents a wide absorption band and strong aggregation effect in solution, which are the key characteristics needed to realize high performance in non-fullerene-acceptor (NFA)-based OSCs. We then prepared OSCs by blending PTVT-T with three representative fullerene- and NF-based acceptors, PC₇₁BM, IT-4F and BTP-eC9. It was found that PTVT-T can work well with all the acceptors, showing great potential to match new emerging NFAs. Particularly, a remarkable power conversion efficiency of 16.20% is achieved in a PTVT-T:BTP-eC9-based device, which is the highest value among the counterparts based on PTV derivatives. This work demonstrates that PTVT-T shows great potential for the future commercialization of OSCs.