Liquid Metal Corrosion Effects on Conventional Metallic Alloys Exposed to Eutectic Gallium–Indium Alloy Under Various Temperature States

The effects of liquid metal corrosion on the thermophysical properties of three conventional metallic alloys, including T2 copper, 304 stainless steel and anodized 6061 aluminum alloy, in the range of 100–400 °C were comprehensively clarified in this paper. It was experimentally found that the corrosion products on the copper surface existed as the intermetallic compound of CuGa₂, and that FeGa₃ and Cr₃Ga₄ were formed on the surface of stainless steel. The heat conductivity of copper plate decreased with the increasing corrosion temperature. The heat conductivity of the corroded copper sample sharply decreased at the beginning stage. When the copper plate was exposed in liquid eutectic gallium–indium over 12 h, the trend of the tested heat conductivity changing curve showed a smooth tendency and reached a steady state finally. The heat conductivity of the corroded copper plate was decided by the corrosion speed with an exponential function of \( v = a^{t} (0.4 < a < 0.6) \). Corrosion phenomena were not found on the surface of the anodized 6061 aluminum alloy according to the experimental results from ambient temperature to 400 °C, which disclosed their suitability as the structural material. The present findings would serve as an important reference for the use of liquid metal cooling in high-power electronic devices and high-temperature systems.     

Heterogeneous Single‐Atom Catalyst for Visible‐Light‐Driven High‐Turnover CO2 Reduction: The Role of Electron Transfer

Visible‐light‐driven conversion of CO₂ into chemical fuels is an intriguing approach to address the energy and environmental challenges. In principle, light harvesting and catalytic reactions can be both optimized by combining the merits of homogeneous and heterogeneous photocatalysts; however, the efficiency of charge transfer between light absorbers and catalytic sites is often too low to limit the overall photocatalytic performance. In this communication, it is reported that the single‐atom Co sites coordinated on the partially oxidized graphene nanosheets can serve as a highly active and durable heterogeneous catalyst for CO₂ conversion, wherein the graphene bridges homogeneous light absorbers with single‐atom catalytic sites for the efficient transfer of photoexcited electrons. As a result, the turnover number for CO production reaches a high value of 678 with an unprecedented turnover frequency of 3.77 min^?1, superior to those obtained with the state‐of‐the‐art heterogeneous photocatalysts. This work provides fresh insights into the design of catalytic sites toward photocatalytic CO₂ conversion from the angle of single‐atom catalysis and highlights the role of charge kinetics in bridging the gap between heterogeneous and homogeneous photocatalysts.     

寒冷地区医院病房设计——缩短护理单元初探

本文就现有医院护理单元设计中存在的弊端探索现代化医院护理单元设计新布局,以数个方案进行分析比较,说明从现有经济条件出发,结合寒冷地区的气候特点,在最大限度利用南向的前提下,适当利用东西向,突破原有一字形布局,使护理单元长度缩短,分区明确,减少干扰,为实现医院现代化创造最佳治疗环境.     

利用废聚乙烯薄膜制造石蜡的研究

本文主要讨论了用废聚乙烯薄膜制石蜡的可行性.采用高温、低压的反应条件,加入自制的催化剂;可制得石蜡,其熔点在54～57(℃)产率达80％以上.该研究给塑料的利用,净化环境提供了可靠的依据.     

基于用户访问模式的数据挖掘技术在大型图书网站中应用的研究

数据挖掘技术分支很多,其中,基于用户访问模式的挖掘(也称Web日志挖掘或使用记录的挖掘)对于一个企业网站的建设有重要的意义.本文结合一个大型图书网站的建设,来研究基于用户访问模式的数据挖掘技术在大型网站中的应用.首先介绍了用户访问模式(Web使用记录)挖掘的基本流程,接着详细介绍了数据结构的设计,数据顸处理,挖掘算法的应用,规则的生成等关键性的数据挖掘技术,最后介绍了产生的规则的应用.     

周口市气象局网络实时监控系统的设计与实现

随着网络技术的迅猛发展,对网络运行状态的实时监控显得十分重要。通过综合分析我局整个网络拓扑结构,开发了基于delphi语言环境的实时网络监控系统,介绍了该系统的实现必要性、功能、设计原理和实现流程。投入业务应用的实践表明,该系统实用性强,对网络系统实时监控效果很好,大大提高了网络的有效性和可靠性。     

浅论教育信息化对教师发展的新要求

教育信息化就是将信息技术在教育领域加以开发利用,教师在教育信息化的过程当中起着重要的媒介作用。信息化教育的发展,教师职能、教学方法和角色等都发生了转变,要求教师必须不断通过思想提升、加强信息技术学习、提高信息运用能力和学习创新等方法不断充实和完善自身素质。     

基于Django快速开发Web应用

Django是Python的一个优秀的开源Web开发框架,在Web开发方面具有简洁、清晰、高效、安全的优点,特别适合快速构建各类Web应用。通过一个留言板的开发实例,论述了基于Django快速开发Web应用的基本原理和过程。     

A Link-Node Discrete-Time Dynamic Second Best Toll Pricing Model with a Relaxation Solution Algorithm

Dynamic congestion pricing has become an important research topic because of its practical implications. In this paper, we formulate dynamic second-best toll pricing (DSBTP) on general networks as a bilevel problem: the upper level is to minimize the total weighted system travel time and the lower level is to capture motorists’ route choice behavior. Different from most of existing DSBTP models, our formulation is in discrete-time, which has very distinct properties comparing with its continuous-time counterpart. Solution existence condition of the proposed model is established independent of the actual formulation of the underlying dynamic user equilibrium (DUE). To solve the bilevel DSBTP model, we adopt a relaxation scheme. For this purpose, we convert the bilevel formulation into a single level nonlinear programming problem by applying a link-node based nonlinear complementarity formulation for DUE. The single level problem is solved iteratively by first relaxing the strick complementarity by a relaxation parameter, which is then progressively reduced. Numerical results are also provided in this paper to illustrate the proposed model and algorithm. In particular, we show that by varying travel time weights on different links, DSBTP can help traffic management agencies better achieve certain system objectives. Examples are given on how changes of the weights impact the optimal tolls and associated objective function values.

消除尖峰脉冲对数据采集干扰的设计与实现

介绍了一种基于现场可编程门阵列(FPGA)和状态比较方法的数据采集系统;通过详细分析A、B两相信号的状态变化特征和比较这两相信号在其1/4周期内的状态变化情况,将比较结果作为计数判据,设计了对光电传感器数据信号进行四倍频以及辨向计数的系统,并给出基于FPGA实现的方法;该方法的优势在于采用状态采样和比较的方法实现计数操作,避免了尖峰脉冲干扰,极大地提高了系统的稳定性和精确性.