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21.
为了掌握傣族与汉族中学生的身体素质现状,文章运用文献资料法、对比分析法、数理统计法等,对汉族与傣族中学生的速度素质、耐力素质、力量素质、柔韧素质进行对比分析,结果表明:在速度素质方面,汉族男生优于傣族男生,傣族女生则优于汉族女生;在耐力素质中方面,13岁这个年龄段傣族男女生均优于汉族男女生,14、15岁则汉族男女生优于傣族男女生;力量素质方面,傣族男女生总体上优于汉族男女生;柔韧素质方面,汉族男女生优于傣族男女生。  相似文献   
22.
ABSTRACT

Many museums are housed in historic buildings, sometimes the building itself is part of the museum collection. Creating a stable environment by providing a nearly constant temperature and relative humidity at correct levels decreases the risk of object degradation. Maintaining this steady indoor environment, however, increases energy consumption and risks to the historic building. Museum display cases offer a solution to the mitigation of risks to which valuable objects may be subjected by providing an extra layer of protection to indoor climate fluctuations. The Anne Frank House is a historic house museum located in Amsterdam. The museum has undergone several renovations in the last years to deal with an increase in the number of visitors to over 1.2 million a year. The original diaries and other documents of Anne Frank are permanently on display in the Anne Frank House. With the recent refurbishment the possibility arose to design a new state-of-the-art display case. This study presents the results of the experimental research related to the design, performed in-situ. The temperature and relative humidity in the new exhibition space and inside the new display cases were monitored to gain insight into the hygrothermal behavior of these controlled environments. A complementary numerical study was performed to investigate effects of dynamic climate control of the exhibition gallery and climate conditions in the display case under various circumstances. Four main conclusions are presented in this paper. The investigated display case design is able to provide a stable relative humidity environment by means of silica gel, while using an active box-in-box climate control system to create stable temperature conditions. The inner case temperature depends on the temperature supplied by the display case air handling unit. Protocols must be in place in case of malfunction or failure of the climate control system of the display case. The air handling unit of the case needs to be shut off to create a passive environment for the objects on display until necessary actions are taken. Exhibition gallery set points can be less stringent when susceptible museum objects are on display in the display case. The environments are separated and provide an opportunity for energy saving set point strategies. The last conclusion drawn is that the numerical study provides valuable insight into imposing dynamic control of set points for temperature and relative humidity in the exhibition gallery and the effect on the display case environment.  相似文献   
23.
This study enhances the existing literature on online trust by integrating the consumers’ product evaluations model and technology adoption model in e-commerce environments. In this study, we investigate how perceived value influences the perceptions of online trust among online buyers and their willingness to repurchase from the same website. This study proposes a research model that compares the relative importance of perceived value and online trust to perceived usefulness in influencing consumers’ repurchase intention. The proposed model is tested using data collected from online consumers of e-commerce. The findings show that although trust and e-commerce adoption components are critical in influencing repurchase intention, product evaluation factors are also important in determining repurchase intention. Perceived quality is influenced by the perceptions of competitive price and website reputation, which in turn influences perceived value; and perceived value, website reputation, and perceived risk influence online trust, which in turn influence repurchase intention. The findings also indicate that the effect of perceived usefulness on repurchase intention is not significant whereas perceived value and online trust are the major determinants of repurchase intention. Major theoretical contributions and practical implications are discussed.  相似文献   
24.
Research on the adoption of systems for big data analytics has drawn enormous attention in Information Systems research. This study extends big data analytics adoption research by examining the effects of system characteristics on the attitude of managers towards the usage of big data analytics systems. A research model has been proposed in this study based on an extensive review of literature pertaining to the Technology Acceptance Model, with further validation by a survey of 150 big data analytics users. Results of this survey confirm that characteristics of the big data analytics system have significant direct and indirect effects on belief in the benefits of big data analytics systems and perceived usefulness, attitude and adoption. Moreover, there are mediation effects that exist among the system characteristics, benefits of big data analytics systems, perceived usefulness and the attitude towards using big data analytics system. This study expands the existing body of knowledge on the adoption of big data analytics systems, and benefits big data analytics providers and vendors while helping in the formulation of their business models.  相似文献   
25.
Students in the same class can differ considerably in their perceptions of teaching quality, but little is known about the drivers of this lack of agreement. In this study, we relied on within-class consensus as a measure of agreement in students' perceptions and explored both student-reported predictors (Sample 1) and teacher-reported predictors (Sample 2) of consensus in students’ ratings of six goal structures dimensions (task, autonomy, recognition, grouping, evaluation, time). Classroom-level results from multi-level models indicated that student-perceived differential teacher treatment negatively predicted consensus regarding evaluation, as well as achievement heterogeneity, whereas instructional clarity positively predicted consensus for recognition, grouping, and evaluation, as well as class-average achievement (Sample 1). Mediating effects of achievement heterogeneity and achievement were not statistically significant. In Sample 2, negative effects of teacher-reported emotional exhaustion and teaching-related anxiety on consensus were observed for several dimensions. Teaching-related enjoyment had no effect.  相似文献   
26.
针对早高峰短时交通流量预测数据少、波动大的特点,提出用灰色模型进行预测。将灰色GM(2,1)改进为灰色GM(2,1,λ,ρ)预测模型,以提高预测精度。针对粒子群算法(PSO)的早熟现象,将Logistic混沌搜索嵌入到PSO算法,应用混沌粒子群算法(CPSO)寻找灰色GM(2,1,λ,ρ)预测模型最优的参数λ和ρ。结合两者提出了基于CPSO–GM(2,1,λ,ρ)的早高峰短时交通流预测模型。利用VISSIM对研究路网进行微观交通仿真,通过VISSIM–Excel、VBA–Matlab平台实现了短时交通流量预测和路网微观交通仿真数据的交互,对集成交通控制系统的架构进行了方案设计。仿真结果表明,结合流量预测的路网优于固定信号配时下的路网仿真。  相似文献   
27.
确保计算机应用基础教学效能得到有效发挥,已成为中职教育工作者关注的焦点。文章探讨项目教学法在计算机应用基础教学中的应用,指出教师要以学生兴趣为出发点,实现任务情境的创设;以实践探究为驱动点,注重学生技能的锻炼;以开放环境为切入点,倡导创新能力的培养。  相似文献   
28.
With the prevalence of digital technologies, various services have grown digitalized. Specific to the marketing section, multichannel has been gradually replaced by omnichannel, which aims to integrate all the physical and digital channels tightly. Although omnichannel has received considerable attention, there is still a dearth of research that theorizes the multi-faceted impacts of digitalization on omnichannel. This study thus extends social cognitive theory (SCT) to the digitalized context and contextualizes the digitalized customer and digitalized environment as mobile identity and channel integration quality, respectively. Moreover, based on the self-regulation process of human agency, we incorporate omnichannel self-efficacy, satisfaction, and habit as the agentic factors to interpret a customer’s conscious (ability and expectancy beliefs) and unconscious (automatic behavioral tendency) decision-making under the omnichannel setting. Through an online survey of 401 omnichannel customers, we find support for all the proposed hypotheses. Implications and limitations of this study are further discussed.  相似文献   
29.
目的观察12周惯性哑铃练习对轻度认知损害(MCI)老年人认知功能、身体活动能力、生活质量和睡眠质量的影响,并探讨认知改善与其他功能改变之间的关系。方法将45名MCI老年人随机分为干预组(n=22)和对照组(n=23)。干预组受试者进行惯性哑铃练习(3次/周,60 min/次,持续12周),对照组不进行运动干预。结果 12周后,干预组受试者阿尔茨海默病评定量表-认知部分(ADAS-Cog)总分/指令得分、蒙特利尔认知评估量表(MoCA)评分、起立行走计时(TUG)和SF-36健康调查问卷(SF-36)心理总得分均显著改善(均P<0.05)。与对照组相比,干预组受试者ADAS-Cog总分/单词回忆得分/注意力得分、简明精神量表(MMSE)评分、TUG和匹兹堡睡眠指数(PSQI)的改善程度均具有显著差异(P<0.05或P=0.05)。偏相关分析结果显示,SF-36心理总得分改变(r=-0.712)、PSQI改变(r=-0.380)与认知改善程度均呈显著负相关。结论 12周惯性哑铃练习可显著提高MCI老年人的认知功能,并对其移动能力、生活质量和睡眠质量具有积极影响,且心理和睡眠改变程度可能影响认知功能的改善效果。  相似文献   
30.
Soybean accounts for more than half of the global production of oilseed and more than a quarter of the protein used globally for human food and animal feed. Soybean domestication involved parallel increases in seed size and oil content, and a concomitant decrease in protein content. However, science has not yet discovered whether these effects were due to selective pressure on a single gene or multiple genes. Here, re-sequencing data from >800 genotypes revealed a strong selection during soybean domestication on GmSWEET10a. The selection of GmSWEET10a conferred simultaneous increases in soybean-seed size and oil content as well as a reduction in the protein content. The result was validated using both near-isogenic lines carrying substitution of haplotype chromosomal segments and transgenic soybeans. Moreover, GmSWEET10b was found to be functionally redundant with its homologue GmSWEET10a and to be undergoing selection in current breeding, leading the the elite allele GmSWEET10b, a potential target for present-day soybean breeding. Both GmSWEET10a and GmSWEET10b were shown to transport sucrose and hexose, contributing to sugar allocation from seed coat to embryo, which consequently determines oil and protein contents and seed size in soybean. We conclude that past selection of optimal GmSWEET10a alleles drove the initial domestication of multiple soybean-seed traits and that targeted selection of the elite allele GmSWEET10b may further improve the yield and seed quality of modern soybean cultivars.  相似文献   
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