摘要：A dynamic quantitative theory and measurement of power or dominance structures are *** power structures are represented as directed networks.A graph somewhat similar to the Lorenz curve for inequality measurement is *** changes in the graph resulting from network dynamics are *** are operationalized in terms of added nodes and *** of dynamic aspects of networks is essential for potential applications in many fields such as business management,politics,and social *** such,we provide examples of a dominance structure in a directed,acyclic *** calculate the change in the D-measure,which is a measure expressing the degree of dominance in a network when nodes are added to an existing simple network.

摘要：当前在线学习存在学习者大多缺乏在线自主学习能力、以自主学习为主要学习方式的在线学习坚持率比较低、学习质量不高等突出问题。本研究借鉴国外引领式在线学习(Instructor-Led Online Learning)的理念,依托陕西师范大学教育技术学专业课程"教学系统设计",开展了引领式在线学习活动的设计与实施,并对学习活动设计及实施的成效进行了检测和验证。结果表明,引领式在线学习活动对学习者的学习态度、学习行为以及元认知能力等方面均有不同程度的正向积极影响。

摘要：Jet pulse assembly is one of the main components of jet hydraulic *** pressure wave characteristics produced by jet pulse assembly have an important influence on the performance of the *** this paper,the structure and working principle of jet pulse assembly are studied,the mechanical analysis model of piston rod is established,the dynamic resistance ratio formula of jet pulse assembly is deduced,and the numerical simulation test of 89-mm jet pulse assembly structure parameters is carried *** results show that the piston rod downward stroke is driven by both the jet element driving force and the throttle plate load driving force,and can stably *** driving force of the piston rod upward stroke jet element is opposite to the load acting force of the throttle disc,and the jet driving force needs to be greater than the load resistance of the throttle disc to stably *** dynamic resistance ratio formula is *** the area of the end of the piston rod is reduced,the resistance of the throttle disc is reduced and the jet power is increased,thus solving the problem of insufficient power of the piston rod in the upstroke and ensuring the normal operation of the *** groups of numerical simulation tests were carried out,and it was found that the pressure amplitude and pressure drop of the tool decreased significantly with the increase of the tool size,and the error between the numerical simulation value and the theoretical calculation value was less than 9%,which verified the correctness of the *** is suggested to select tools on site according to the drilling construction situation to ensure the drilling effect.

摘要：长链末端环氧化物(LCTE)由于大位阻侧基的存在,难以高选择性地与二氧化碳(CO_(2))共聚并得到高碳酸酯单元含量的聚合物.本研究通过在卟啉meso苯环不同位置引入大位阻有机碱1,5,7-三叠氮双环[4.4.0]癸-5-烯(TBD),设计了一系列双功能卟啉铝催化剂,旨在调控TBD基团与铝中心的空间协同作用.其中TBD连接在meso苯环间位上的催化剂m-4展现出最佳的催化效果,可高选择性(99%)催化1,2-环氧丁烷或1,2-环氧己烷与CO_(2)完全交替共聚,制备得到分子量大于32 kg/mol的聚碳酸酯.通过原位红外光谱对反应进行动力学研究证明该催化剂分子内协同的催化特征.本文工作探究了双功能催化剂分子内催化位点的空间分布与所产生协同作用的关系,为LCTE/CO_(2)高效交替共聚合成聚碳酸酯提供了一种新思路.

摘要：This paper discusses the design of a customer satisfaction measurement index system of erpress mail service. It presents objectives and principles of the design based on hierarchical structures. We have devised a diagram for modeling customer satisfaction, and a detailed analysis of customer satisfaction is conducted. This paper presents our customer satisfaction model and analysis results.

摘要：受天然酶启发,协同作用被广泛应用于小分子的识别及其催化转化,但在聚合物合成领域的研究仍然有限.本文报道了一种柔性桥联双核卟啉铝催化剂(FTBC),成功实现了CO_(2)与环氧丙烷(PO)的高效交替共聚.该策略的关键在于通过调控柔性链的长度使得活性位点相互靠近,从而促进分子内协同作用.受益于活性位点的协同效应,以―CH_(2)―为柔性链的C_(1)-Al_(2)表现出优异的催化活性(380 h^(−1))及较高的聚合物选择性(96%),优于相同条件下的单分子卟啉铝(活性为300 h^(−1),聚合物选择性为78%).即使在低催化剂浓度下,C_(1)-Al_(2)也能保持较好催化活性(250 h^(−1)).动力学实验表明C_(1)-Al_(2)反应级数为一级,证实催化剂的分子内协同催化主导共聚过程.本文报道了一种柔性桥联双核催化剂的构筑策略,为模块化设计高性能催化剂提供了新方向.

摘要：近几年,虚拟广告系统在全球广播电视行业中得到广泛的应用。首先通过介绍虚拟广告系统的基本原理,结合作者实现的小型虚拟广告系统的具体环节,对系统中涉及的关键技术在理论上进行了探讨。然后详细介绍了作者实现的小型虚拟广告系统的软硬件开发环境,体系结构,以及在工程实践中采用的具体设计方案。最后对该系统性能进行了分析说明。

摘要：A new type of sample cell specially designed for micro-Raman spectra study on volatile melts is described. The cell is made of quartz. The lower section of the cell is circular ring-shaped and the one-end-closed hole in the cell is used for locating the heating body. The tube attached to the cell lid for placing the thermal couple is inserted into the sample, which ensures that the temperature measurement accuracy is good. The cell can be sealed for reducing the effect of the composition change caused by the in_homogeneous volatilization. During the Raman spectra scanning, the laser beam is transmitted into the cell through the side but not the top. Meanwhile, a furnace has been designed to match the cell. The heating body is closely coupled with the sample cell, and there is a hole on the side wall of the furnace for the entrance of the microlens. The assembly has performed well in the tested Raman spectrum measurement of molten NaNO3 at 602 ℃.

摘要：目的让没有物像、色彩概念的视障者在多感官体验辅助下,通过触感颜料实现绘画艺术表达,拓宽特殊教育在艺术教学中的方式与工具。方法以实践验证设计成果,通过材料感官分析法,完成触感颜料的设计与制作。基于广州市启明学校三次艺术绘画表达课的观察测试,依托DIY材料法推动迭代与优化,最终实现触感颜料系统的设计。结论触感颜料打破了嗅觉、触觉与视觉多感官间的界线,不仅能够提升视障者的绘画体验,更能激发他们的跨感官创作灵感,获得积极心理艺术治疗,最终实现视障者与普通人之间的艺术交流与分享,促进社会福祉品质的提升。

摘要：为解决自动化装配过程中工件定位难,安装精度差等问题,设计了一种对点云质量适应性强的高精度、高效率的盘盖类工件自动化装配视觉引导系统。首先使用点云包围盒提取点云数据ROI,并对其进行去噪及降采样的预处理步骤。接着提出了一种使用有限元网格中心点制作点云模板的方法,并对PCA算法进行了主轴及质心矫正的改进,提高了算法对点云质量的容忍度,实现了点云数据快速准确配准。最后对点云模板制作方法的有效性、改进PCA算法的配准效果、算法对点云质量的容忍度、算法对不同零件的鲁棒性及系统整体精度进行了实验验证。系统最终的平移误差均值为0.80 mm,RMSE小于0.089 mm;旋转误差均值为1.24 mm,RMSE小于0.116 mm,完全满足了自动化装配的要求。实验结果表明,所提出的方法在点云质量容忍度、配准的精度及效率方面具有优越的综合性能。