随机质心映射优化法(RCO)提取皮亚曼石榴皮中黄酮类化合物

利用随机质心映射优化法(RCO),以乙醇浓度、超声时间、提取温度和料液比为影响因子,研究新疆皮亚曼石榴皮中黄酮类化合物的超声波提取工艺。结果表明:经过RCO两轮循环后得出超声波法提取石榴皮中黄酮类物质最佳工艺:乙醇浓度为87%、超声时间为37 min、提取温度为59℃、料液比为1∶24(g/m L)。优化后皮亚曼石榴皮中总黄酮的得率为25.56%。经过相关性分析得知,提取温度和乙醇浓度对总黄酮的得率影响较大,且呈负相关,表明皮亚曼石榴皮中黄酮类化合物的极性较大。当石榴皮黄酮浓度为12 mg/m L时,对DPPH自由基的清除率可达91.6%。      

天鹅蛋中主要致腐微生物的分离与鉴定

在贮藏期间,天鹅蛋容易被环境微生物通过蛋壳表面的气孔侵染而腐败,大大降低其市场价值。该研究从腐败天鹅蛋中分离得到5株细菌,对其进行形态、生理生化特性研究,并结合16s rRNA基因序列分析和系统发育树分析,最终分别鉴定为氧化节杆菌(Arthrobacter oxydansi)、成团泛菌(Pantoea agglomerans)、麦氏弧菌(Vibrio metschnikovii)、屎肠球菌(Enterococcus faecium)和粪产碱杆菌(Alcaligenes faecalis)。本研究为天鹅蛋的抗菌防腐贮藏提供了参考。      

激光填丝焊接镍基合金/304不锈钢二次相的转变机制及其对晶间腐蚀性能的影响

为了阐明激光填丝焊接镍基合金(Hastelloy C-276)/304二次相的转变机制和晶间腐蚀机制,通过EPMA和TEM对二次相进行分析;采用双环动电位再活化法(DL-EPR)对焊接接头的晶间腐蚀性能进行评价,并采用EDS对焊接接头腐蚀表面进行成分分析.实验结果表明:p相和μ相为完全共格关系,且其共格关系为[001]...     

Experimentation of a Membrane-based Concentration Gradient Energy Storage of Liquid Desiccant Solutions Driven by Solar Energy

Solar energy storage is an indispensable and sustainable utilization mode of renewable energy; environment friendly, large-capacity, low heat loss, and long-term storage are critical to improving the integration of solar energy supply. Traditional thermal energy storage mode cannot achieve long-term storage due to the heat loss even under the excellent thermal insulation measures. In this work, a solar-powered membrane-based concentration gradient energy storage of liquid desiccant solutions is presented. In the membrane distillation process driven by solar energy under the right solar radiation conditions, the liquid desiccant solution is concentrated gradually and long-term stored as the concentration gradient energy. To this end, the measured temperature of solar hot water is in the range of 40°C to 90°C from May to September, 2018, in Xi'an, China. And then, the Li Br solution(50 wt%), the Li Cl solution(35 wt%), and the Ca Cl2 solution(40 wt%) were membrane-based concentrated in the temperature range of 42°C to 63°C, separately. The results showed that the water vapor pressure difference decides the water vapor transferred across the membrane pores from the liquid desiccant side to the air side. The energy storage density of liquid desiccant solutions increases along with the increases in temperature and the membrane area. Consequently, when the Li Br, Li Cl, and Ca Cl_2 solutions are concentrated from 50% to 55%, from 35% to 40%, and from 40% to 45%, separately, the concentration energy storage density is 245 k J/kg, 350 k J/kg, and 306 k J/kg, which is equivalent to or even higher than ice storage capacity. Due to the two independent closed cycle of the liquid desiccant solution and air, the liquid desiccant solution's concentration gradient energy storage can be long-term stored environment-friendly without any insulation measures.     

Array-level boosting method with spatial extended allocation to improve the accuracy of memristor based computing-in-memory chips

Memristor based computing-in-memory chips have shown the potentials to accelerate deep neural networks with high energy efficiency.Due to the inherent filament-...     

基于性能的钢框架结构失效模式识别及优化

该文定义了损伤和滞回耗能两个性能指标,以增量动力分析(IDA)方法为基础,提出基于性能的钢框架结构失效模式识别方法,并以性能指标为目标函数,以构件截面尺寸作为变量,建立钢框架结构失效模式多目标优化方法。在多条地震波作用下,对一个20层benchmark钢框架结构进行了失效模式识别与优化分析,结果表明,以损伤和滞回耗能作为评价指标的基于性能的钢框架结构失效模式识别方法,能有效识别最不利地震作用下的结构失效模式,基于性能的失效模式多目标优化方法能够显著提高结构整体的抗震性能。     

超微粉碎对菠萝蜜超微全粉品质的影响

为了明确超微粉碎工艺对菠萝蜜粉品质的影响,本文以真空冷冻-变温压差膨化联合干燥的菠萝蜜粗粉为原料,研究了超微粉碎时间对菠萝蜜超微全粉的各项理化和营养品质的影响。实验结果表明,超微粉碎时间对菠萝蜜的粒径的影响较小,经5min粉碎后即可达到超微粉的要求;菠萝蜜粉的溶解性指数和持水力与超微粉碎时间呈上升趋势,类胡萝卜素和维生素C含量与超微粉碎时间呈下降趋势;通过真空冷冻-变温压差膨化联合干燥方法干燥法获得的菠萝蜜粉的流动性可满足实际生产的需要,产品的吸湿性较小,不易粘结。      

明日叶/薏仁米营养保健面条的研制

为了满足人们对饮食既有营养又有保健功能的要求,本文以薏仁米粉、芭蕉芋淀粉、明日叶汁和小麦粉为主要原料制备具有保健功能的营养面条。考察了薏仁米粉、芭蕉芋淀粉、明日叶汁、黄原胶和食盐不同添加比例对明日叶/薏仁米营养面条品质的影响。通过正交实验、感官评定和物性测定确定该营养面条的最佳配方为:薏仁米粉14%,芭蕉芋淀粉10%,黄原胶0.3%,食盐1.7%,小麦粉74%的混合粉,添加混合粉质量40%的明日叶汁进行和面制作面条。按最佳配方制作的面条表面光滑、富有弹性、断条率和溶出率低、口感细腻,营养丰富且具有保健功能。      

混合菌种发酵酸马乳的降血脂功能研究

为研究混合菌种发酵酸马乳的降血脂作用,采用混合菌种发酵酸马乳对小鼠进行实验,研究其对高脂模型小鼠体重、血脂水平、脏器指数和动脉硬化（AI）指数的影响。结果表明,混合菌种发酵酸马乳中、高剂量能够显著降低高血脂症小鼠TC、TG、LDL-C、AI水平（p<0.05）,显著升高HLD-C水平（p<0.05）,并且能降低小鼠体重和肝脏指数,说明混合菌种发酵酸马乳对实验性高脂血症小鼠具有降低血脂的作用,对高脂血症及动脉粥样硬化具有一定的预防作用。      

单增李斯特菌非可培养状态的诱导与PMA-qPCR检测

在9%（w/v）NaCl条件下,通过温度、pH两种因素诱导一株单增李斯特菌进入\