Phenolic contents,antioxidant activities and potential bioaccessibilities of industrial pomegranate nectar processing wastes

Antioxidant potential and bioaccessibility of co‐products from industrial pasteurised pomegranate nectar (PN) processing such as peel (PP), press cake (PC) and precipitate after clarification (PAC) in comparison with raw material (arils) and final products (CON and PN) were determined. Total phenolic (TPC), flavonoid (TFC), anthocyanin (TAC), tannin contents (TTC) and antioxidant activity (TAA) were determined besides identifying major phenolics and investigating in vitro bioaccessibility after gastrointestinal (GI) digestion. PP showed the highest values, except for TAC. Phenolics (12.7–43.0%) were found to be more stable than anthocyanins (0.6–2.1%) after in vitro GI digestion. PAC was found to be a better source for anthocyanins than CON and also showed higher phenolic bioaccessibility (28.8%) than PN (19.6%). PC and PAC possessed as much TPC, TFC, TTC and TAA levels as CON, with some exceptions. Therefore, these results indicated that not only PP but also PC and PAC should be valorised as a good source for phenolics and anthocyanins.     

Microstructure and mechanical properties of Mg-xY-1.5MM-0.4Zr alloys

Age hardening,microstructure and mechanical properties of Mg-xY-1.5MM-0.4Zr (x=0,2,4,6 wt.%) alloys (MM represents Ce-based misch-metal) were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the formed precipitates being responsible for age hardening changed from fine hexagonal-shaped equilibrium Mg12MM phase to metastable β’ phase with bco crystal structure when Y was added into Mg-1.5MM-0.4Zr alloy,and the volume fraction of precipitate phases also increased. With the increase of Y content in Mg-Y-1.5MM-0.4Zr alloys,it was found that the age hardening was enhanced,the grain sizes became finer and the tensile strength was improved. The cubic-shaped β-Mg24Y5 precipitate phases were observed at grain boundaries in Mg-6Y-1.5MM-0.4Zr alloy. It was suggested that the distribution of prismatic shaped β’ phases and cubic shaped β-Mg24Y5 precipitate phases in Mg matrix might account for the remarkable enhancement of tensile strength of Mg-Y-MM-Zr alloy. It was shown that the Mg-6Y-1.5MM-0.4Zr alloy was with maximum tensile strength at aged-peak hardness,UTS of 280 MPa at room temperature and 223 MPa at 250 oC,respectively.     

铸态Mg96Zn3Y1合金高温热处理显微结构的电子显微研究

本文应用扫描背散射电子(SEM-BSE)像和透射电子显微(TEM)像观察的方法,研究了铸态Mg96Zn3Y1(at.％)合金经过500℃高温热处理后显微组织结构的变化.结果表明铸态Mg96Zn3Y1(at.％)合金中的初生相为网格状形貌,其中多数为面心立方W(Mg3Zn3Y2)相,少数为二十面体准晶Ⅰ(Mg3Zn6Y)...     

时效处理对铸轧7050铝合金组织和性能的影响

采用透射电镜、X射线衍射、硬度测试等实验方法,研究了不同时效处理工艺对铸轧7050铝合金组织和性能的影响。结果表明：随着单级时效温度的升高,合金达到峰值硬度所需的时间缩短,合金的峰值硬度降低,晶内和晶界析出相也随温度的提高发生不同程度的长大;双级时效时,晶内有较多粗大的析出相,晶界析出相已不再连续且已经发生长大,晶界无沉淀带更加明显;回归再时效处理时,晶内析出相与单级时效时相比发生粗化,晶界上为断续的粗大长条状析出物,无偏析带加宽。     

从电子结构和成键特性分析高Cu/Mg比Al-Cu-Mg-Ag合金强化机制

提出了计算高Cu/Mg比Al-Cu-Mg-Ag合金主要析出相W相及相界面电子结构的计算模型与方法,从合金相结构因子和相界面结合因子分析了合金的强化机制。基于余氏的固体分子经验电子理论和程氏改进的TFD理论,对Al-Cu-Mg-Ag合金主要析出相Ω相及相界面电子结构进行了计算,发现合金相及相界面价电子结构与合金强化机制有密切的关系,并从电子结构层次上阐释分析了合金中θ′, Ω,θ相的竞争相析出机制及对合金强化机制的影响     

Precipitation Behavior of α Phase and Mechanical Properties in Severely Plastic Deformed Ti-15-3 Alloy

研究了大变形量冷轧Ti-15-3合金的时效析出行为和时效过程中力学性能的变化。冷变形使Ti-15-3合金中形成部分纳米晶。冷变形合金在450～650℃时效时,从β相纳米晶区析出极为细小的针状α相,而从β相非纳米晶区析出的α相随着时效温度的升高由针状逐渐长大为条状,进而演变为凸透镜状。冷变形合金在450℃时效4h后,硬度达到了峰值,HV为5328MPa。450℃时效时在硬度峰值处同样达到了强度峰值,屈服强度和抗拉强度分别可高达1483和1562MPa。时效温度升高,达到峰值硬度的时间缩短,硬度值大幅度下降。650℃时效后的强度和硬度均低于时效前,粗大的透镜状析出相、纳米晶的长大以及位错密度的急剧下降是650℃时效时硬化效果消失的主要原因。不同时效工艺下的强度和硬度的变化规律相似,性能的变化与时效过程中析出相的状态有关。     

固溶热处理对新型镍基粉末FGH98Ⅰ高温合金组织与性能的影响

对新型镍基粉末高温合金(FGH98Ⅰ)在不同温度下进行固溶热处理,采用热力学相计算、光学显微镜、场发射扫描电镜及化学相分析等研究了亚固溶和过固溶合金的析出相和显微组织,并综合分析了组织与性能的关系。结果表明:FGH98Ⅰ合金经1130℃亚固溶和1190℃过固溶处理后的析出相均为γ’、MC、M23C6和M3B2等,未发现TCP(拓扑密堆)相。FGH98Ⅰ合金亚固溶热处理后晶粒稍有长大,存在尺寸不同的初次、二次和三次γ′相;过固溶热处理合金的晶粒明显长大,存在单模分布的二次γ′相;前者由于晶粒较小使强度更高,后者因减小二次γ′相尺寸和消除初次γ′相,PPB(原始颗粒边界)和残余枝晶,提高了合金的高温塑性和持久性能,说明不同晶粒尺寸和γ′相特征是FGH98Ⅰ盘件获得双性能的关键因素。     

铜杂质在太阳电池用多晶硅中的沉淀及吸杂行为(英文)

采用扫描红外显微镜、光学显微镜、电感耦合等离子质谱仪和微波光电导衰减仪对铜杂质在多晶硅中不同缺陷状态区域的沉淀和吸杂行为进行研究。发现铜杂质沉淀行为与缺陷密度密切相关,在低缺陷密度区域铜杂质大多易于均质形核形成沉淀,而在高缺陷密度区域铜杂质通常会聚集在缺陷处异质形核而沉淀下来。当铜沾污量较高时,由于在硅基体中的肖特基二极管效应,铜沉淀会令多晶硅中的载流子寿命明显缩短。在900℃下进行快速磷吸杂处理后,这两种区域中的铜杂质都不能得到有效去除。     

铌对船板钢大热输入焊接热影响区组织与韧性的影响

采用控轧控冷工艺(TMCP)生产含铌(质量分数0.025%)和无铌两种DH36级船板钢,并进行150 kJ·cm^-1大热输入气电立焊,研究了焊接接头热影响区的组织与韧性。结果表明:铌元素的添加可推迟铁素体和珠光体相变,促进粒状贝氏体和贝氏体铁素体生成,导致含铌钢热影响区粗晶区中的晶界铁素体含量较少,粒状贝氏体和贝氏体铁素体含量较多,细晶区中的铁素体和珠光体析出缓慢。无铌钢焊接接头各区域的组织与韧性良好,-20℃冲击功单值均在102 J以上,远高于船级社规范要求;含铌钢焊接接头熔合线处-20℃冲击功出现单值低于24 J的情况,不满足船级社规范要求,其他区域-20℃冲击功单值均在143 J以上。铌的添加对DH36级船板钢大热输入焊接接头的韧性不利。     

高温氘离子辐照对低活化钢微观结构的影响

材料问题是可控核聚变能否实现商业应用从而解决人类能源问题的"瓶颈"之一。低活化铁素体/马氏体(RAFM)钢具有良好的抗辐照性能,被普遍认为是新一代聚变反应堆的候选结构材料之一。在聚变堆环境下,材料不仅会受到高能中子辐照而且氘氚也可能进入材料中。为了研究氘离子以及辐照对低活化钢的微观结构的影响,采用CLAM钢(一种RAFM钢)和FeCr模型合金,在500℃下进行58keV氘离子辐照,利用高分辨透射电镜对比分析辐照前后材料微观结构的变化,研究辐照及氘离子对低活化钢的影响。结果表明:高温氘离子辐照不仅在材料中产生大量的缺陷和缺陷集团,同时还可能产生辐照诱导析出。而CLAM钢中原有的析出物经高温离子辐照后并没有发生非晶化,对其原因进行了讨论。