The Effects of Experience and Strategy on Visual Attention Allocation in an Automated Multiple-Task Environment

Operators and users interacting with computer environments often have to deal with multiple tasks at once, responding to each in series. Diagnostic automation, that is, automation that alerts users when and where to look, has been suggested to support the unique challenges of multiple task environments: activating tasks, switching between tasks, and tasks interfering with each other. Automation is not always reliable, however. Because of the common interaction with novel systems and the importance of training, the Simultaneous Task Environment Platform program—a multiple-task environment—was developed to understand the effects of experience on interaction with these automation-supported systems, as well as what strategies were developed. It was found that participants became more efficient with experience only when they interacted with higher reliability automation. Furthermore, the strategies participants developed focused on the differences between tasks and patterns across those tasks. Automated systems training should be sure to employ these findings.     

基于单片机的简易电子琴的设计与实现

电子琴是现代电子科技与音乐结合的产物,是一种新型的键盘乐器。它在现代音乐扮演重要的角色,单片机具有强大的控制功能和灵活的编程实现特性,它已经溶入现代人们的生活中,成为不可替代的一部分。该文的主要内容是用8253芯片为核心控制元件,设计一个简易电子琴。通过按动STAR ES598PCI单板机的G6区的1~7号键,使用单板机上的8255A芯片进行音调的选择,由8253芯片控制产生不同频率的方波,输出到单板机上D1区的蜂鸣器,使其对应于G6区的1~7号键由低到高发出1~7的音阶,并由8255A芯片控制8253芯片的工作状态,使其能够控制蜂鸣器的发声与否,从而实现简易电子琴的演奏功能。同时,也可以通过事先设置好的“乐谱”回放一段音乐,实现简易电子琴的回放功能以及对用户演奏过的一段音乐进行重放功能。用户可以通过DOS界面下的菜单对电子琴的回放和重放或是演奏功能进行选择。     

环己烷在Au-Co/SBA-15上选择性氧化的研究

以沉积-沉淀法制备了Au-Co/SBA-15催化剂,在没有任何有机溶剂或助剂的条件下,研究了以空气为氧化剂的环己烷选择性氧化。当Au-Co/SBA-15催化剂中金的质量百分含量为1.0%,催化反应在423 K 3.0 MPa下进行120 m in时,催化效果最好,此时环己烷的转化率为22.7%,环己酮和环己醇的总选择性为95.2%,酮醇比为2.9,且催化剂重复使用五次后活性基本不变。     

Isomerization Dynamics of Dicyanine A in n-Alcoholic Solution

The radiationless relaxation of dicyanine A molecules in n-alcohols methanol to butanol has been studied by picosecond fluorescence spectroscopy and time-resolved nonlinear spectroscopy. The fluorescence decay rates have been measured as a function of viscosity, temperature, and fluorescence wavelength. It is shown that the wavelength dependence can be explained by coexistence of two ground-state conformers. The intrinsic activation barrier for the nonradiative decay from the excited surface is very small, much less than 1 kcal/mol. In a particular solvent the time constants of the nonradiative relaxation show a linear dependence on the variation of viscosity. The experimental data are discussed in relation to the BFO theory (Bagchi, B.; Fleming, G.R.; Oxtoby, D.W. J. Chem. Phys. 1983, 78: 7375).     

Laminar and turbulent mass transfer simulations in a parallel plate reactor

Laminar and turbulent mass transfer in a parallel plate reactor at high Schmidt number obtained from numerical simulation is compared with literature data. In a first step, the fluid flow is determined numerically in the reactor by solving the Navier–Stokes equations. For turbulent flow, a low Reynolds number k— model is used to calculate the turbulent viscosity. Using the obtained flow field and turbulent viscosity, the current density distribution is calculated for different flow velocities by solving the equations describing the transport of multiple ions due to diffusion, convection and migration. For the laminar case, a very good agreement with literature data is obtained. For turbulent flow, different numerical models for turbulent mass transfer are proposed in the literature. A detailed study of the behaviour close to the wall of these different turbulence models is presented, together with a comparison of the calculated results with literature correlations. This allows identification of the benefits and disadvantages of each of the turbulence models for the numerical calculation of mass transfer at high Schmidt numbers in a parallel plate reactor.     

谈武术散打训练对大学生社会适应能力的影响

运用文献资料法、实验研究法,对武术散打实战教学对大学生社会适应能力的影响进行研究.结果表明:武术散打实战教学对促进大学生社会适应能力的发展有重要作用.其有助于提高学生的探索能力、培养良好的意志品质和心理承受力:有助于强化学生的规范意识,增强学生调控自己行为和态度的能力;有助于提升大学生的集体荣誉感和社会责任感.建议在教学中通过规则学习、角色扮演、情景设置等方法有针对性地提高大学生社会适应能力.     

垃圾焚烧发电在欧美的实践与在中国的推行

从欧美国家的发展实践来看,无论是环保效应还是经济社会效益,垃圾焚烧发电都是一种可行乃至优选的垃圾处理方式。垃圾焚烧发电方式在中国的推行,目前仍面临加强技术标准和政府监督监控、协调政府意志与公众诉求、做好垃圾分类等难题。     

一种多参数优化的联合信源信道编码方法*

针对JPEG2000码流的渐进传输特性,提出了一种多参数优化的联合信源信道编码方法,即MPO-JSCC。在码率分配的基础上,动态地选择Turbo码交织长度、迭代译码次数,通过优化编码器多个参数更好地执行不等差错保护策略,同时加入JPEG2000容错工具,在接收端利用错误掩藏机制以提高图像解码成功率。将该方法应用于噪声信道的图像传输系统中,仿真结果表明,MPO-JSCC既能在不增加系统复杂度及延迟时间的同时提高重建图像的质量,又能节省系统发射功率,具有一定的现实指导意义。     

发达国家食品召回机制给我们的启示

建立健全食品安全召回机制,已成为许多国家食品安全监督管理的新型理念、重要手段和发展趋势.对美国、加拿大、澳大利亚、新西兰、欧盟等发达国家和地区在食品召回的法律保障、职责分工、召回程序、信息系统等方面的主要特点进行分析和总结,就我国在食品安全召回的法律体系、机构设置、技术支撑、实施过程、应急措施等方面的现状和存在的问题进行对比研究,并就建立和完善我国食品召回机制提出了完善法律法规体系、加强技术支撑建设、明确管理协调机构、建立完备溯源体系、加强教育宣传培训、完善应急处理体系等建议和对策.     

超支化芳香族聚酰胺酯单体的合成及表征

以3,5-二羟基苯甲酸为原料合成芳香族AB2型单体2-(3,5-二羟基苯甲酰)邻氨基苯甲酸,由此作为超支化聚酰胺酯的单体,并用红外光谱和核磁共振氢谱对其结构进行表征.2-(3,5-二羟基苯甲酰)邻氨基苯甲酸单体的成功合成将为超支化聚合物的制备奠定基础.