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101.
针对仪器分析实验学生仪器操作时间少、积极性不高、教学效果不佳的情况,从教学模式、教学内容、教学方法、教学管理等方面提出了具体的改进措施,有效地提高仪器分析实验教学质量。 相似文献
102.
Social commerce is becoming an important hub for product sourcing, which helps companies to connect with customers and to gain competitive advantages. However, very little empirical research that focuses on small-and medium-sized enterprises (SMEs) has been conducted to date. This study examines factors that affect social commerce adoption by SMEs. Using the Technology-Organisation-Environment (TOE) as the theoretical framework, the researchers tested the model and related hypotheses, employing structural equation modelling. The results from a survey of 181 SMEs in Saudi Arabia indicate that trading partner pressure in the environmental context, followed by top management support in the organisational context, and perceived usefulness in the technological context, have the most significant influence on behavioural intention to use social commerce. The research contributions and conclusion as well as limitations and future research directions are presented. 相似文献
103.
For this critical intercultural inquiry, I as an Asian/Japanese transnational cisgendered gay man write my autoethnography of queer (or non-heteronormative) Asian–Black (dis)connections. Specifically, I challenge, interrogate, and problematize my queer intercultural production of desire and attraction as I engage in my critical autoethnographic interrogation of dialogues with five Asian/Japanese transnational gay men who have previously engaged in queer Asian–Black relationality. In so doing, I intend to create a potential point of departure to decenter the discursive and material effects of White gay normativity in the knowledge production of Asian queer male desire and attraction. 相似文献
104.
近代欧洲西方国家来华的商贾、传教士、旅行家,以葡萄牙人、西班牙人为最早。他们对中国的文字记载中,不乏对长城的涉及与描述,因此,伊比利亚文献对于我们了解基督教文化对长城的评价及其在旧世界传播的起始时间具有决定性意义。本文比较详细地爬梳了16-17世纪伊比利亚史料中关于长城的各种记载,分析了几部主要历史著作的史料来源。 相似文献
105.
BackgroundHealth-related fitness knowledge (HRFK) has been an essential concept for many health and physical education programs. There has been limited understanding and longitudinal investigation on HRFK growth. This longitudinal study examined HRFK growth and its individual- and school-level correlates in middle school years under 1 curriculum condition: Five for Life.MethodsParticipants were 12,044 students from 47 middle schools. Data were collected at both individual/participant and school/institution levels. Individual-level variables included gender, grade, and HRFK test scores. School-level variables included percentage of students receiving free and reduced meals (FARM), student-to-faculty ratio for physical education, and school academic performance (SAP). We used hierarchical linear modeling to examine HRFK 3-year growth in relation to individual- and school-level correlates.ResultsThe average HRFK score at 6th grade for females was 42.81% ± 1.32%. The predicted HRFK growth was 17.06% ± 1.02% per year, holding other factors constant. A 1-standard deviation increase in FARM correlated with a 14.68%-point decrease in predicted test score (p = 0.02). A 1-standard deviation increase in SAP was associated with an 11.90%-point increase in HRFK score. Males had a significantly lower growth rate than females during the middle school years (0.78%/year, p = 0.02).ConclusionThe result showed that both individual- and school-level variables such as gender, FARM, and SAP influenced HRFK growth. Educators should heed gender differences in growth curves and recognize the correlates of school-level variables. 相似文献
106.
考虑到生鲜品的易腐性、高时效性和对运输环境要求高的特点,为减少生鲜品配送企业的配送成本,提高客户满意度,在车辆载重、时间窗、生鲜品保质期等约束条件下,提出将配送总成本最小化和生鲜品新鲜度最大化的多目标车辆路径优化模型。利用改进的非支配排序遗传算法(non-dominated sorting genetic algorithmⅡ,NSGAⅡ)对模型进行求解。求出满足配送总成本最小和生鲜品新鲜度最大的相对较优解,证明模型的有效性。该模型在大规模配送和客户地理位置分布较为分散的情况下,对生鲜品新鲜度的优化较为明显。 相似文献
107.
为研究固体表面结构对液滴撞击液膜后演变行为的影响规律,采用CLSVOF方法模拟液滴撞击不同尺寸槽道上的表面液膜的流动过程,获得不同槽道高度和宽度时液滴撞击液膜后的演变行为,探索撞击速度、液膜黏度和表面张力对撞击后液膜铺展行为、水花飞溅高度和二次液滴形成的影响。结果表明,槽道结构对液滴撞击液膜后的动态行为具有显著影响,随着槽道高度的增加,冠状水花厚度越薄,越容易产生二次液滴;随着液膜黏度的增大,则抑制冠状水花形成与二次液滴的产生;液膜表面张力减小时,射流更加明显,二次液滴数更多,飞溅现象提前,冠状水花消失时间延后。 相似文献
108.
为解决航空发动机空心涡轮叶片陶瓷型芯的3D打印难题,研究基于图像投影的复杂结构陶瓷型芯光固化成型(mask-image projection stereolithography,MIP-SLA)方法。搭建MIP-SLA工艺系统平台,对陶瓷浆料的制备和打印工艺参数的配置进行研究。分析利用球磨机将光敏树脂和陶瓷颗粒进行混合制备陶瓷浆料时,光敏树脂类型、固相含量、陶瓷颗粒粒径、分散剂含量和球磨时间对陶瓷浆料性能的影响。对不同配置参数下的打印效果进行对比分析,对确定的最佳打印工艺参数进行打印效果验证。 相似文献
109.
Junzhen Ren Pengqing Bi Jianqi Zhang Jiao Liu Jingwen Wang Ye Xu Zhixiang Wei Shaoqing Zhang Jianhui Hou 《国家科学评论(英文版)》2021,8(8)
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. 相似文献
110.
Youngtae Choi 《Journal of Intercultural Communication Research》2019,48(3):292-313
This study explores how horizontal/vertical individualism and collectivism (HVIC) orientations influence electronic word-of-mouth (eWOM) (i.e., opinion leadership and opinion seeking) in social media. Online survey panel data through Amazon MTurk were collected from American social media users to address the research purpose. The results, using the structural equation modeling, show that the paths from horizontal individualism to opinion leadership, vertical individualism to opinion leadership and opinion seeking, horizontal collectivism to opinion leadership, and vertical collectivism to opinion leadership and opinion seeking were significant. This study provides theoretical and managerial implications regarding the influence of HVIC orientations on eWOM in social media. 相似文献