青岛循环经济探析

发展循环经济已被列为青岛市“十一五”时期的重要战略任务。发展循环经济是青岛实现经济可持续发展的战略选择。推进循环经济发展是一项事关全局和长远的战略任务,政府要继续加强对循环经济的领导、充分发挥推动作用,企业要遵守行业发展规律、加强自律,市民要提高参与的意识和能力。     

顶点可迁图为star extremal的一个充要条件

一个图当它的圆色数和分色数相等称之为star extremal. 本文首先给出一个图的圆色数等于顶点数除以独立数的充要条件. 然后利用这个结果给出了顶点可迁图是star extremal的一个充要条件. 并由此得到了几类新的star extremal图.     

同尺寸弯振圆盘辐射声场指向性研究

对薄圆盘的弯曲振动和辐射声场的特性进行了研究,推导出了三种边界条件下圆盘辐射声场指向性的数值表达式,编制程序并研究其声辐射特性。结果表明,相同尺寸不同边界条件下圆盘指向性的尖锐程度不同,固定边界条件下圆盘辐射声场指向性最佳,自由边界条件下较差,并且随着圆盘模式和几何尺寸的增加各边界条件下圆盘的指向性均逐渐变差。     

Adding immersive virtual reality to a science lab simulation causes more presence but less learning

Virtual reality (VR) is predicted to create a paradigm shift in education and training, but there is little empirical evidence of its educational value. The main objectives of this study were to determine the consequences of adding immersive VR to virtual learning simulations, and to investigate whether the principles of multimedia learning generalize to immersive VR. Furthermore, electroencephalogram (EEG) was used to obtain a direct measure of cognitive processing during learning. A sample of 52 university students participated in a 2 × 2 experimental cross-panel design wherein students learned from a science simulation via a desktop display (PC) or a head-mounted display (VR); and the simulations contained on-screen text or on-screen text with narration. Across both text versions, students reported being more present in the VR condition (d = 1.30); but they learned less (d = 0.80), and had significantly higher cognitive load based on the EEG measure (d = 0.59). In spite of its motivating properties (as reflected in presence ratings), learning science in VR may overload and distract the learner (as reflected in EEG measures of cognitive load), resulting in less opportunity to build learning outcomes (as reflected in poorer learning outcome test performance).     

IT engagement as a blessing and a curse? Examining its antecedents and outcomes in organizations

Information technology (IT) engagement is defined as a need to spend more time using IT. Practice-based examples show that IT engagement can have adverse effects in organizations. Although users can potentially get more work done through IT engagement, observations show that the users might jeopardize their well-being and hamper their work performance. We aimed to investigate this complexity in the research on IT engagement by examining its potential antecedents and outcomes in organizations. Considering the potentially mixed outcomes, we developed a model to examine the effects of IT engagement on personal productivity and strain. We also aimed to explain the antecedents of IT engagement by drawing on the collective expectations for IT use. In particular, we examined the extent to which normative pressure on IT use drives users’ information load and IT engagement. Finally, we sought to understand whether users’ attempts to avert dependency on IT use reduced their IT engagement. Several hypotheses were developed and tested with survey data of 1091 organizational IT users. The findings help explain the role of normative pressure as a key driver of IT engagement and validate the positive and negative outcomes of IT engagement in organizations.     

低负荷加压训练改善自发性高血压大鼠的血压效果及机制研究

目的:探究低负荷加压训练对自发性高血压大鼠的降压效果及其作用机制。方法:选取4周龄雄性自发性高血压大鼠,随机分为对照组(高血压安静组)、低负荷训练组、低负荷加压训练组和高负荷训练组。低负荷训练组进行35%~55%1RM递进式低负荷爬梯训练,低负荷加压训练组进行30%~40%血流受限结合35%~55%1RM递进式低负荷爬梯训练,高负荷训练组进行55%~75%1RM递进式高负荷爬梯训练,训练后测定血压、血液中内皮素-1、血管内皮生长因子、一氧化氮合成酶的表达和心肌组织中内皮型一氧化氮合成酶的表达。结果:1)与对照组、高负荷训练组相比,低负荷加压训练组收缩压、舒张压显著下降(P<0.05);与低负荷训练组相比,低负荷加压训练组舒张压显著下降(P<0.05)。2)与对照组相比,低负荷加压训练组血液中内皮素-1表达显著下调(P<0.05),血管内皮生长因子和一氧化氮合成酶表达显著上调(P<0.05);3)与对照组相比,低负荷加压训练组心肌中内皮型一氧化氮合成酶表达显著上调(P<0.05);4)在低负荷加压训练组中,收缩压与内皮素-1呈正相关,相关性分析具有统计学意义(P<0.05);收缩压与一氧化氮合成酶、血管内皮生长因子、内皮型一氧化氮合成酶均呈负相关,相关性分析具有统计学意义(P<0.05)。结论:1)低负荷加压训练降压效果优于高负荷训练;2)低负荷加压训练能够通过下调血液中内皮素-1的表达,上调血液中血管内皮生长因子和一氧化氮合成酶的表达,同时上调心肌中内皮型一氧化氮合成酶表达,改善内皮细胞功能,达到降压的效果。     

关于企业铁路C62A型号货车增载的可行性探讨

随着国民经济的发展,铁路车辆的需求矛盾日益突出,从增加运输能力的角度考虑,对现有的车辆进行增载是一个投资少、见效快的途径,根据企业铁路目前使用的C62A型车辆的主要技术参数及状况,从垂直动载荷及技术指标分析,在标记载重60t的基础上增重5t是可行的,并能产生较大的经济效益,可以在企业铁路上进行推广。     

基于PSO的电力系统环境经济负荷调度

针对基于线性加权和处理成单目标优化问题的传统方法存在的缺陷,提出使用粒子群优化算法求解EELD多目标优化问题。该方法通过对粒子群算法个体极值和全局极值选取方式的改进,实现了对EELD多目标优化问题的非劣最优解集的搜索,为决策者提供了丰富的参考信息。在此基础上,应用模糊满意度方法求出的最优折衷解为调度运行人员提供了最佳调度折衷方案。最后,对一个三机系统进行了测试,并与线性加权人工神经网络法进行了比较分析,仿真结果验证了该方法的有效性。     

Expertise Reversal Effect and Its Implications for Learner-Tailored Instruction

The interactions between levels of learner prior knowledge and effectiveness of different instructional techniques and procedures have been intensively investigated within a cognitive load framework since mid-90s. This line of research has become known as the expertise reversal effect. Apart from their cognitive load theory-based prediction and explanation, patterns of empirical findings on the effect fit well those in studies of Aptitude Treatment Interactions (ATI) that were originally initiated in mid-60s. This paper reviews recent empirical findings associated with the expertise reversal effect, their interpretation within cognitive load theory, relations to ATI studies, implications for the design of learner-tailored instructional systems, and some recent experimental attempts of implementing these findings into realistic adaptive learning environments.     

我国男子高水平三级跳远运动员专项力量训练安排研究

摘要：男子三级跳远是我国参加奥运会田径比赛的潜优势项目,专项力量是影响三级跳远比赛成绩和技术水平提升的关键因素,运用文献资料法、专家访谈法、实地调查等研究方法,分析研究我国最优秀的6名男子三级跳远运动员专项力量训练安排。结论：1）我国男子高水平三级跳远运动员的力量训练内容、方法手段、计划与负荷基本符合世界潮流,但训练中缺少单腿支撑进行的蹲、拉、提、举等练习,不够贴近专项需要;2）专项力量训练器材与世界发达国家相比科技化含量不高;3）专项力量负荷调整控制主要依赖教练员经验与身体素质指标推算。