A composition and size controllable approach for Au-Ag alloy nanoparticles

ABSTRACT: A capillary micro-reaction was established for the synthesis of Au-Ag alloy nanoparticles (NPs) with a flexible and controllable composition and grain size by tuning the synthesis temperature, the residence time, or the mole ratio of Au3+:Ag+. By extending the residence time from 5 to 900 s, enhancing the temperature from 120degreesC to 160degreesC, or decreasing the mole ratio of Au3+:Ag+ from 1:1 to 1:20, the composition of samples was changed continuously from Au-rich to Ag-rich. The particles became large with the increase of the residence time; however, synthesis temperatures showed less effect on the particle size change. The particle size of the Au-Ag alloy NPs with various composition could be kept by adjusting the mole ratio of Au3+:Ag+. TEM observation displayed that the as-obtained NPs were sphere-like with the smallest average size of 4.0 nm, which is half of those obtained by the traditional flask method.     

钢质药筒热处理技术研究

对药筒力学性能进行了简单的分析,介绍了钢质药筒的成形工艺。结合钢材的超强韧热处理原理,阐述了钢的2种超细化方法。根据钢质药筒的冲压成型过程,重点探讨了如何改进钢质药筒热处理工艺,提高体部、底部力学性能的新途径。     

Evolution of phenols and pigments in extra virgin olive oil from irrigated super‐intensive orchard

Phenolic compounds have a high importance in olive oil because of their effect on shelf life and sensory properties. This study reports on the HPLC profiles of the phenolic compounds of virgin olive oils obtained from Arbequina olives from the harvesting in a super‐intensive orchard under a linear irrigation system. In addition, phenolic content, carotenoid and chlorophyllic pigments, and oxidative stability were analyzed. Total phenol content and 3,4‐DHPEA‐EDA increased up to a maximum throughout the ripening process. The simple phenols tyrosol and hydroxytyrosol acetate increased throughout the ripening process, however, there was not found a clear trend in hydroxytyrosol content. Minor constituents such as vanillic acid and p‐coumaric acid increased up to a maximum and then decreased, since vanillin decreased progressively throughout the time of harvest. 3,4‐DHPEA‐EDA and lignans were present in considerable amounts in the studied samples, while oleuropein aglycone was present in a low amount. Total phenol content and oil stability followed the same trend throughout the study, so a very good correlation was established between them. Total secoiridoids and, specifically, 3,4‐DHPEA‐EDA seemed to be responsible for oil stability. The pigment content decreased during ripening, and not a positive correlation was found between pigments and oil stability. Practical applications : The results can be used to determine the best time for harvesting in order to obtain olive oils with different phenols and pigment contents. This is important for sensory characteristics of the olive oils and also for olive oil stability.     

不规则钣金件加工

对一不规则钢板零件的加工方法进行分析,此钢板零件设计时摆放位置主要考虑装配要求,在机械加工和检验时有很大的难度,容易产生变形尺寸。分别从设计基准与工艺基准转换和选择加工方式、装夹方式来解决加工和检验难题。     

基于就业岗位的城市总体规划人口规模预测初探 ——以重庆市长寿城市总体规划为例*

快速城镇化进程中,城市发展的不确定因素越来越多,现有的以人口自然增长率和机械增长率为基本变量的总体规划人口规模预测方法已经难以适应这一客观趋势。针对人口的超常规增长,本文以重庆市长寿区中心城区人口预测为例,从常住人口产生的本质动因入手,提出基于就业岗位的人口预测方法,并对长寿区中心城区的人口进行了预测。     

浅议建筑钢结构发展

本文简要地叙述了我国建筑钢结构发展现状,仅从钢结构先进技术的角度对"鸟巢"、"水立方"等具有代表性的钢结构建筑进行了评价和赞扬。以建筑结构的表现形式为题材,说明改革开放以来我国钢结构行业取得了辉煌的成就。     

基于Optistruct的地铁构架有限元强度分析及优化

建立地铁构架的有限元模型,根据UIC515-4、UIC615 4和EN13749标准对构架进行静强度和疲劳强度评定.结果表明,构架符合静强度和疲劳强度要求.此外还使用Optistruct软件对构架板材厚度进行尺寸优化,优化结果符合构架静强度和疲劳强度评定要求,优化结果可行.优化结果相比初始设计,减重达到12.3％.     

物联网/智能地球:海量/大数据流新产业(Ⅰ)

硅谷的国家实验室SLAC发明与创建了可不断升级、标准化的"超级仪器",用于获取、判选、重组、分析"粒子、宇宙、生命"等微观信息,引导硅谷发展生命产业。其4维海量/大数据流,又造就了下游企业群如IBM创新"蓝色基因"计算机及"互联网数据中心"系列,为海量/大数据流新产业"物联网/智能地球"打下高技术基础,而海量/大数据流新产业中的"绿色智能互联网数据中心"亦是自动化应用的新领域。     

后注浆超长大直径灌注桩承载性能试验研究

以软土地区桥梁桩基础为工程依据,进行了普通和后注浆超长大直径灌注桩的静载试验和桩身轴力测试,对比分析了普通灌注桩和后注浆灌注桩的承载性状,发现在软土地区后注浆技术能有效地改善超长大直径灌注桩桩端和桩侧土层特性,增加桩侧摩阻力和桩端阻力,使单桩承载能力得到明显提高,此项试验研究可为软土地区的类似工程提供参考和借鉴。     

斜撑转换结构在超限高层建筑中的应用——厦门观音山公寓结构设计

厦门观音山公寓为百米高层建筑,本文介绍了该工程结构体系、超限情况判定、抗震性能化设计原则及相应的抗震加强措施;着重介绍了斜撑转换结构设计的关键问题,可为结构设计人员借鉴参考。