一种380 V交流输入的多路输出开关电源

介绍了一种用于大功率IGBT厚膜驱动电路的380V系统输入、多路输出辅助开关电源。该开关电源采用新颖的双管串联模式，解决了高电压输入条件下开关管的选用难题。与传统供电电源相比，该电源电路简单、体积小、重量轻、效率高、允许输入电压范围宽，具有很高的实用价值。该电源已研制成功并已投入实际应用。     

项目驱动法运用于《个人理财》课程教学探析

高校《个人理财》课程旨在培养学生能够综合运用理财知识对处于经济社会中的个人和家庭进行理财规划的能力。因此,不仅要向学生传授个人理财的知识与技巧,更要培养他们的实际应用能力。本文针对高校《个人理财》课程的教学特点,通过项目驱动教学法在课程教学中的运用,提出教师可以在实现教育目标方面,提高学生自主学习方面,以及提高学生关键能力方面,给予学生有针对性地培养与指导。     

中国美丽乡村建设驱动机制研究

强劲的驱动机制是推进我国美丽乡村建设的重要保障。基于网络治理和系统论的学术资源,尝试构建了美丽乡村建设驱动机制系统模型,对其形成机理和主体驱动力特点进行分析。在宏观层面,政府、农民、资本和社会力量在推进美丽乡村建设的进程中要充分地互动协同和有效整合,以形成强大、可持续的合力。在中微观层面,要促进驱动要素层次的协调优化;不仅要注重发挥法律与公共政策、资金与利益的驱动作用,更要重视和增强科技与人才、文化与教育对美丽乡村建设的基础性动力。     

广东省终端能源消费碳排放增长的驱动因素

将居民能源消费的二氧化碳排放纳入研究范围,采用LMDI分解法对2000—2011年广东省终端能源消费碳排放增长的驱动因素进行分析。结果显示:在影响碳排放增长的各种因素中,经济规模、人口规模和收入对碳排放增加整体上表现为正效应;产业结构、生产部门能源强度、生产部门能源结构和能源碳排放因子整体表现为负效应;生活部门的能源强度和能源结构的效应不确定;总体上正向驱动效应超过负向驱动效应,致使广东省的碳排放量呈不断上升态势。     

厚煤层大倾角煤顶下掘进围岩控制数值模拟研究

为研究大倾角煤层开采过程中巷道围岩的稳定状况,以青东矿837机、风巷为工程背景,进行煤层顶底板岩石力学参数实验室测试,利用FLAC3D软件建立不同掘进工艺条件下的数值计算模型,分析软弱特厚煤层巷道分别在跟顶板掘进、全煤层掘进、破底掘进(不同破底深度)条件下巷道围岩破坏范围和变形特征。结果表明：跟顶板掘进方式下,围岩的塑性破坏主要发生在巷道底板下方,需要特别注意加强对底板的支护;跟底板掘进时,底板中部靠近帮脚处产生严重底鼓,应当加强对帮脚和巷帮的支护;在全煤层掘进时,巷道主要变形为底鼓与顶板下沉,顶底板破坏严重。研究成果对于指导大倾角厚煤层开采围岩控制具有一定的理论与工程意义。     

主产区粮食生产时空格局及驱动因素

在国内国际双循环背景下厘清现阶段粮食生产的时空格局及驱动因素的空间分异规律,以更好地发挥粮食主产区对保障中国粮食安全的战略作用.基于粮食主产区2001—2017年粮食生产面板数据,利用探索性空间数据分析检验粮食主产区粮食生产格局的空间模式,采用地理加权回归模型分析粮食主产区粮食产量驱动因素的空间异质性.结果显示:主产区粮食产量处于高-高和低-低集聚的省份较多,处于高-低和低-高集聚的省份较少,且空间相关性随着时间波动下降;2001年及2017年种粮人数对粮食产量的驱动作用呈现出明显的空间异质性,其他因素对各地区粮食产量的驱动作用基本一致.基于上述研究结论,必须在充分考虑粮食主产区地域发展差异的基础上,从提升粮食单产、坚守耕地红线、规范化肥使用、推进农业科技化、防范农业灾害等方面着力改善,以期为中国粮食安全提供科学保障.     

Socially optimal replacement of conventional with electric vehicles for the US household fleet

In this study, a framework is proposed for minimizing the societal cost of replacing gas-powered household passenger cars with battery electric ones (BEVs). The societal cost consists of operational costs of heterogeneous driving patterns' cars, government investments for charging deployment, and monetized environmental externalities. The optimization framework determines the timeframe needed for conventional vehicles to be replaced with BEVs. It also determines the BEVs driving range during the planning timeframe, as well as the density of public chargers deployed on a linear transportation network over time. We leverage data sets that represent US household driving patterns, as well as the automobile and the energy markets, to apply the model. Results indicate that it takes 8 years for 80% of our conventional vehicle sample to be replaced with electric vehicles, under the base case scenario. The socially optimal all-electric driving range is 204 miles, with chargers placed every 172 miles on a linear corridor. All public chargers should be deployed at the beginning of the planning horizon to achieve greater savings over the years. Sensitivity analysis reveals that the timeframe for the socially optimal conversion of 80% of the sample varies from 6 to 12 years. The optimal decision variables are sensitive to battery pack and vehicle body cost, gasoline cost, the discount rate, and conventional vehicles' fuel economy. Faster conventional vehicle replacement is achieved when the gasoline cost increases, electricity cost decreases, and battery packs become cheaper over the years.     

顾客虚假忠诚前置因素研究

本文依据行为和态度两个维度对顾客虚假忠诚的内涵进行了界定，并指出其与顾客真正忠诚的区别。通过对现有文献的梳理。将顾客虚假忠诚的前置因素划分为态度、行为驱动因素和外部、内部情景调节因素，通过深入分析，提出了顾客虚假忠诚的形成机理模型，并提出了维系现有顾客的策略建议。     

城市边缘区空间重构的驱动机理研究述评

20世纪70年代以来,全球生产方式变革和资本积累体制变迁推动着我国快速城市化进程中社会经济体制转型和城市空间重构,城市边缘区作为城市空间增长的前沿阵地和社会异质性最强的地域类型,其驱动机理研究成为当前世界城市研究的热点。西方相关研究在结构-行为-社会行动者三个维度上不断实现理论整合,但考虑到我国独特的制度演化路径和社会经济结构,城市边缘区空间重构机理的构成和运作方式迥异于国外。国内当前研究成果偏重于宏观结构性驱动因素分析,而在相对微观的行为因素和关系因素研究方面还有待深入。因此,强化空间重构的行为过程和社会行动者关系研究,对于推动城市边缘区空间整合与社会融合,研拟空间重构调控策略具有非常重要的理论价值和现实意义。     

Macroforces driving change into the new millennium — major challenges for the hospitality professional

The fast pace of change will present many challenges in the new millennium. The success of the leader of tomorrow will depend on how well he or she is able to identify the forces that will drive change, invest in industry leading competitive methods that will take advantage of the opportunities presented by these forces and consistently allocate resources to these methods. Identifying the forces driving change is the most challenging aspect of this co-alignment concept. This paper explores the macroforces, which can be expected to drive change, and possible impact they will have on the hospitality organization. These forces include: globalization and economic change, a knowledge-based environment, the future of labor and quality in service delivery systems, and the growing consumer desire for improved well-being. These forces are presented along with the key variables making them up with the goal of understanding their complexities and interdependencies.