无针搅拌摩擦点焊技术

为了消除搅拌摩擦点焊固有的“匙孔”缺陷,采用无针搅拌摩擦点焊（probeless friction stir spot welding,P-FSSW）工艺,在不同的焊接参数下对新型铝锂合金2198-T8进行了点焊试验,并分析了点焊接头的金相组织及其力学性能。结果表明,无针搅拌摩擦点焊工艺可以有效消除“匙孔”缺陷,但受工艺限制,无针搅拌摩擦点焊焊接工艺较适用于低熔点合金及薄板焊接。     

环保型石墨易切削钢的研究进展

石墨易切削钢是一种不添加铅的环境友好型机械结构用易切削钢。介绍了国内外石墨易切削钢的研发现状。     

TA15钛合金双重热处理工艺及其微观组织演化的EBSD研究

针对航空航天工业中广泛应用的近a TA15钛合金,开展了不同热处理参数下的双重热处理实验研究。利用背散射电子技术（Electronic backscatter diffraction, EBSD）表征了不同热处理参数下微观组织形貌特征和晶体学取向分布及规律。对比分析了热处理处保温时间对微观组织形貌及取向分布的影响规律。揭示了双重热处理过程中球化的等轴晶粒,条状次生as晶粒及b转变组织的形成演化过程;分析了不同组织间的晶体取向与位置分布关系。研究表明：双重热处理过程中一次保温时间对等轴初生ap形貌及分布等影响较大;热处理过程中球化的等轴晶粒来源于未转变的ap 相;二次保温时间对as形貌、尺寸等具有显著影响;二次保温过程中细条状as表现为先增长再增厚的生长模式;ap与相邻的as晶体学取向关系表现出一定的统计性规律。     

Effect of Extreme Pressure Additives on the Deformation Behavior of Oxide Scale during the Hot Rolling of Ferritic Stainless Steel Strips

High-speed steel (HSS) materials are universally used as work rolls for the hot rolling of stainless steels. Their use has increased the output of the rolling mill and decreased roll material consumption and grinding. Sticking defects often occur, however, during the hot rolling process. In this article, extreme pressure (EP) additives were dropped on the HSS samples at high temperature. Zinc dialkyl dithiophosphate (ZDDP) was chosen as the most effective EP additive by scratch tests on the HSS samples. In order to determine the optimum proportion of ZDDP in the lubricant, two reduction rates were tested on a Hille 100 experimental rolling mill by hot rolling ferritic stainless steel 445J1M at five different concentrations of ZDDP. The mechanism of EP additive action during the hot rolling process was also investigated. By analyzing the deformation behavior of the oxide scale of samples after hot rolling using different proportions of ZDDP, it was found that 20% ZDDP in the lubricant is the preferred concentration for industrial application.     

江苏省市际断面水文监测系统设计与研究

为实现水利工程联合运行、水污染联合防控探索,推进跨区域水生态补偿,形成河湖水环境治理良性发展机制,江苏省市际断面水文监测系统项目应运而生。采用水文现状调查与信息研究相结合的方法,设计基础设施、数据资源、应用支撑、业务应用 4 个层面,以及信息安全和标准规范两大体系的总体框架,分析基于数据汇聚平台与实验室数据资源的数据资源层、应用支撑层、业务应用层的主要建设内容,从而构建省域、市域、县域边界重要河段水量水质统一监测与监控系统。江苏省市际断面水文监测系统的设计与研究,不仅为江苏省流域的精密监测、精细管理、精准调度提供有力支持,也为省内外类似水文监测系统建设提供参考和借鉴。     

Solid-state additive manufacturing and repairing by cold spraying: A review

High-performance metal additive manufacturing (AM) has been extensively investigated in recent years because of its unique advantages over traditional manufacturing processes. AM has been applied to form complex components of Ti, Fe or Ni alloys. However, for other nonferrous alloys such as Al alloys, Mg alloys and Cu alloys, AM may not be appropriate because of its melting nature during processing by laser, electron beam, and/or arc. Cold spraying (CS) has been widely accepted as a promising solid-state coating technique in last decade for its mass production of high-quality metals and alloys, and/or metal matrix composites coatings. It is now recognized as a useful and powerful tool for AM, but the related research work has just started. This review summarized the literature on the state-of-the-art and problems for CS as an AM and repairing technique.     

基于区域卫生信息平台的食源性疾病预警系统设计

目的研究食源性疾病预警系统的设计模式,为政府部门防控食源性疾病提供信息化支撑。方法在人口健康信息化总体框架内,基于地级市区域卫生信息平台采集食源性疾病患者信息,应用地理编码技术对监测数据赋予空间位置属性,应用空间分析方法进行可视化展现和统计分析。结果系统在设计上突破了哨点医院的瓶颈,将采集范围扩展到中山市所有医疗机构和社区卫生服务中心,自动获取符合食源性疾病定义的主诉病例,从个体上掌握全市疑似食源性疾病患者就诊和用药情况,每日夜间汇总当天所有疑似食源性疾病病例,基于空间统计分析模型辅助研判,对疑似聚集性食源性疾病暴发事件进行预警。结论基于区域卫生信息平台的系统设计模式有助于解决我国食源性疾病预警中滞后性的问题,对推进基层公共卫生信息化建设,创新预警防控模式将产生积极的作用。     

文艺复兴时期神心态到大众审美需求研究——以城市广场演变为例

在城市设计中,城市广场是其中很重要的一块。本文以文艺复兴时期城市广场的演变为研究对象,从城市广场的社会品质(非物质要素)和空间品质(物质要素)两个方面,阐述了神心态到大众审美需求的转变。最后提出了对现代中国广场建设的几点建议。     

一氧化氮熏蒸延缓杏干贮藏期间品质的下降

以新疆赛买提鲜杏为试材,研究了一氧化氮(nitric oxide,NO)和二氧化硫(sulfur dioxide,SO₂)气体分别对鲜杏熏蒸后制干对杏干常温(25±1.0℃)下贮藏品质和抗氧化性的影响。结果表明,NO和SO₂熏蒸均能减缓杏干色泽和可溶性糖含量的下降,延缓失重率的上升。贮藏60 d,NO处理组杏干L*、b*、类胡萝卜素、可溶性糖、抗坏血酸(vitamin C,Vc)及总酚、类黄酮含量分别较对照组高9.20%、15.87%、25.20%、39.05%、19.43%和23.08%、11.42%;DPPH·、ABTS⁺·清除率及FRAP值较对照组高45.75%、19.50%、18.07%,较SO₂组高31.77%、9.28%、5.89%。可见NO处理显著减缓杏干营养品质的下降(p<0.05),维持较高的抗氧化能力。此外,NO₂^-和NO₃^-残留量均远低于欧洲委员会和国家标准中规定的最小值,且降解速率快...