高精度数控直流电流源的设计

本设计实现了直流电流源的数字化控制。整个系统由线性受控直流源、精密测量控制电路和人机接口三部分组成。电流源为双环控制系统,通过控制调整管的驱动电流,可精确控制电流源输出值的大小。测试表明该电流源具有良好的稳压稳流性能和极低的电流纹波。     

电子鼻在两种类型浓香菜籽油识别中的应用

采用电子鼻对6种不同炒籽温度和7种不同原料产地油菜籽分别制取的两种类型浓香菜籽油进行了分析。结果表明:通过采集各样品气味信息,电子鼻能够灵敏地检测到浓香菜籽油的香气差异,经数据主成分分析判定,电子鼻既可以很好地区分不同炒籽温度的菜籽油样品,又可以区分不同原料产地的菜籽油样品,因此利用电子鼻技术能建立一种客观、快速区分不同工艺或不同原料浓香菜籽油的评价方法。     

就在你身边——信息设计

在视觉传达设计中,信息的传递是一项基本功能,如何保证良好的信息沟通是设计者极应重视的,尤其是伴随着我国信息化的发展,对信息设计的探究逐渐成为一个独立的、引人瞩目的热点。本文首先介绍信息设计的起源与发展;然后分析信息设计的现状;最后提出我国信息设计研究与应用方面存在的问题。     

就在你身边——信息设计

在视觉传达设计中,信息的传递是一项基本功能,如何保证良好的信息沟通是设计者极应重视的,尤其是伴随着我国信息化的发展,对信息设计的探究逐渐成为一个独立的、引人瞩目的热点。本文首先介绍信息设计的起源与发展;然后分析信息设计的现状;最后提出我国信息设计研究与应用方面存在的问题。     

The construction of a hospital disease tracking and control system with a disease infection probability model

With relatively short latency and rapid propagation, viral diseases could be transmitted through the air to medical personnel or the public during the incubation period. To reduce the possibilities of spread, this research creates an infection probability model based on the settling velocity and concentration distribution of infectious droplets. Then, radio frequency identification (RFID) technology is employed to track the travel history (time, date and place) of the infected patients. A tree structure algorithm and an infection probability model are applied to trace the transmission routes, discover the correlations between carriers and suspected cases, and finally calculate the infection probability on the basis of time interval. In case of an epidemic outbreak or once an infected case is confirmed, the disease tracking and control system could be initiated by accessing RFID logs to plot the carriers’ time of onset and to trace possible routes of transmission via tree diagrams. The disease tracking and control system developed in this research can assist hospitals in assessing the risk of infection among medical personnel, as well as in prompt implementation of infection prevention and control measures, in order to reduce hospital acquired infections and provide a safe health care setting.     

3D Foam Strutted Graphene Carbon Nitride with Highly Stable Optoelectronic Properties

Controlled morphology modulation of graphene carbon nitride (g‐C₃N₄) is successfully realized from bulk to 3D loose foam architecture via the blowing effect of a bubble, which can be controlled by heating rate. The loose foam network is comprised by spatially scaffolded few‐atom‐layer interconnected flakes with the large specific surface area, as supporters to prevent agglomeration and provide a pathway for electron/phonon transports. The photocatalytic performance of 3D foam strutted g‐C₃N₄ toward RhB decomposition and hydrogen evolution is significantly enhanced with the morphology optimization while its excellent optoelectronic properties are maintained simultaneously. Herein, the ultrathin, mono‐, and high‐quality foam g‐C₃N₄ interconnected flakes with controlled layer are facilely obtained through ultrasonic, thus overcoming the drawbacks of a traditional top–down approach, opening a wide horizon for diverse practical usages. Additionally, the layer control mechanism of 3D hierarchical structure has been explored by means of bubble growth kinetics analysis and the density functional theory calculations.     

基于多代理技术的有源配电网供电恢复策略

针对有源配电网发生故障后的快速供电恢复需求,提出基于多代理技术的自愈恢复系统。该系统采用分层协调的恢复模式,由下层区域代理为本区域发起供电恢复进程,上层馈线代理协调处理下层代理间的冲突。提出功率平衡度和转供容量裕度指标,基于该指标,当配电网故障隔离后,非故障失电馈线被分解为多个独立的区域,自愈系统能通过微网聚合恢复失电区域的供电,还可利用联络开关对孤岛区域进行负荷转供,达成综合恢复供电的目标。在供电恢复过程中,同时考虑馈线电压和电流的约束限制,保证系统在故障恢复后的安全稳定运行。在DIgSILENT软件上搭建含分布式电源的4馈线配电系统,仿真结果验证了所提策略的可行性和有效性。     

Understanding student simultaneous smartphone use in learning settings: A conceptual framework

Smartphone use in learning settings is a common behaviour amongst college students. Building on the theory of consumerism, self-efficacy and addictive behaviours, the current study developed a three-component conceptual framework to understand college students' smartphone use in organizational as well as self-directed learning settings. One thousand and thirty-three students in Shenzhen completed an online survey that measured their frequency of using smartphones in learning settings, motivation for using smartphones in learning settings, behavioural control self-efficacy, smartphone use time, problematic smartphone use, multitask habit and impulsiveness. Regression and configurational analytical approaches were used to examine linear and nonlinear relationships. Results support the use of the proposed framework to explain students' smartphone use behaviour in learning settings.     

一种改进的并行蝙蝠算法

针对蝙蝠算法存在易陷入局部最优、后期收敛速度慢及收敛精度低等问题,提出一种改进的并行蝙蝠算法(IPBA).设计一种基于免疫浓度的混沌初始化,选择出适应度高、浓度低的个体组成更高质量的初始群体;引入并行策略,将种群分为探索与开发两个子群体,采用不同的惯性权重和停滞变异策略分别进化,可有效防止早熟,并加快算法收敛速度.此外,子群体间定期进行个体迁移和信息交换,充分发挥并行优势,提高算法的整体性能.通过对经典函数仿真测试,将IPBA与基本算法和其他改进算法的优化结果进行对比,经过相关分析,验证了IPBA的可行性和有效性.     

An ergonomics study of computerized emergency operating procedures: Presentation style, task complexity, and training level

Emergency operating procedures (EOPs) are widely used in nuclear power plants (NPPs). With the development of information technology, computerized EOPs are taking the place of paper-based ones. Unlike paper-based EOPs, the industrial practice of computerized EOPs is still quite limited. Ergonomics issues of computerized EOPs have not been studied adequately. This study focuses on the effects of EOP presentation style, task complexity, and training level on the performance of the operators in the execution of computerized EOPs. One simulated computerized EOP system was developed to present two EOPs, each with different task complexity levels, by two presentation styles (Style A: one- and two-dimensional flowcharts combination; Style B: two-dimensional flowchart and success logic tree combination). Forty subjects participated in the experiment of EOP execution using the simulated system. Statistical analysis of the experimental results indicates that: (1) complexity, presentation style, and training level all can significantly influence the error rate. High-complexity tasks and lack of sufficient training may lead to a higher error rate. Style B caused a significantly higher error rate than style A did in the skilled phase. So the designers of computerized procedures should take the presentation styles of EOPs into account. (2) Task complexity and training level can significantly influence operation time. No significant difference was found in operation time between the two presentation styles. (3) Training level can also significantly influence the subjective workload of EOPs operations. This implies that adequate training is very important for the performance of computerized EOPs even if emergency responses with computerized EOPs are much more simple and easy than that with paper-based EOPs.