Antibacterial and photocatalytic behaviour of green synthesis of Zn0.95Ag0.05O nanoparticles using herbal medicine extract

The present work aimed to synthesize Zn_0.95Ag_0.05O (ZnAgO) nanoparticles using rosemary leaf extracts as a green chemistry method. The characterization of Ag-doped ZnO nanoparticles was performed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and ultraviolet–visible spectrophotometry (UV–visible). The XRD, FTIR, and UV–visible spectra confirmed the formation of the presence of hexagonal ZnAgO nanoparticles. FESEM micrograph shows that the nanoparticles have been distributed homogeneously and uniformly. The morphology of ZnAgO nanoparticles is quasi-spherical configuration. Also, the mean particle size is in the range of 22–40 nm. The photocatalytic degradation of methylene blue in the presence of Ag-doped ZnO nanoparticles is nearly 98.5% after exposing 100 min. The ultraviolet lamp was used as the light source for photocatalyst degradation. The disc diffusion method was chosen to study the antibacterial activity of as-synthesized ZnAgO nanoparticles. Antibacterial activity of Zn_0.95Ag_0.05O nanoparticles against Staphylococcus aureus and Escherichia coli revealed that the as-synthesized ZnAgO nanoparticles were efficient in inhibition of bacterial growth.     

印刷电路板缺陷检测的实际应用

电路板在我们的日常生活中非常常见,这就使得印刷电路板的缺陷检测显得尤为重要。AOI作为新兴的检测PCB板缺陷的系统,在生产实际中正在被大家熟知并且应用。相较于传统的检测方式,AOI系统比较灵活,无论是在检测时间还是系统运算上,或者是对相关技术人员的要求相较于传统方式都比较有优势,本文就AOI系统在实际中的应用展开讨论,分析并且介绍了在实际应用中的具体细则。     

五味子泡腾片的制备工艺及质量评价

研究五味子泡腾片的制备工艺,并对其进行质量评价。以崩解时限、产气量、pH值为评价指标,采用单因素和正交试验优化泡腾崩解剂配比、泡腾崩解剂质量分数、聚乙二醇(polyethylene glycol,PEG)6000的用量,并通过片剂重量差异、崩解时限、pH值、产气量、硬度及脆碎度和五味子醇甲的含量对产品进行质量控制。结果表明,柠檬酸∶碳酸氢钠最佳配比为1∶0.7(质量比),泡腾崩解剂的最佳质量分数为55%,五味子水提物浸膏质量分数26%,PEG 6000的最佳质量分数为5%,甜菊糖苷2%,氯化钠2%,乳糖10%。最优工艺条件下制备的泡腾片,外表呈浅粉色,片剂表面光滑,可迅速溶于水中,产生丰富气泡,汤色呈浅粉色,并伴有五味子特有香气,口味酸甜适中,口感良好,每片泡腾片中五味子醇甲的含量为(9.79±0.18)mg,平均片重(500±20)mg,崩解时限为(87.42±1.91)s,pH值平均值为4.63±0.071,崩解时限、pH值均符合药典规定。     

迷迭香提取物及其包结物在中式培根中的应用

研究了迷迭香提取物(RE)的化学成分、抗氧化活性及RE与其环糊精钾金属有机骨架包结物(RE-K-CD-MOF)在中式培根中的应用。结果表明:RE的主要成分为迷迭香酸等12种物质;RE具有良好的抗氧化效果,在0.5~1.5 mg/mL浓度范围内,清除DPPH自由基的能力大于BHT小于V_C,在1~5 μg/mL浓度范围内,清除OH自由基的能力大于V_C小于BHT。应用于中式培根腌制过程中脂质氧化实验表明,与对照组相比添加RE及RE-K-CD-MOF各组均具有较低的过氧化值和丙二醛含量;与添加RE各组相比,添加RE-K-CD-MOF各组表现出更好的稳定性和抑制脂质氧化效果。与添加0.3% RE相比,添加0.3% RE-K-CD-MOF时,加工结束时中式培根的过氧化值降低了17.8%,丙二醛含量降低了17.2%。     

耐热型纸吸管纸的制备及性能研究

以漂白硫酸盐针叶木浆和阔叶木浆为原料，通过湿法成形、表面施胶及涂布耐热胶黏剂制备耐热型纸吸管纸，主要采用挺度、环压强度、湿抗张强度及接触角等指标评价纸吸管纸性能；对比探究了耐热胶黏剂与普通胶黏剂对纸吸管性能及使用安全性的影响。结果表明，CW/AKD混合乳液施胶量为14 g/m²，AKD用量为0.10%（相对于原纸定量，其中里纸定量100～140 g/m²，面纸定量40～80 g/m²）时，纸吸管里纸、面纸挺度分别为3.59 mN·m和2.63 mN·m，环压强度分别为1.75 kN/m和0.37 kN/m，抗张强度分别为7.68 kN/m和3.57 kN/m，湿抗张强度分别为1.43 kN/m和0.78 kN/m，吸收性分别为29.8 g/m²和27.2 g/m²，接触角分别达到145.9°和149.4°；热水抽出物含量分别为3.252%和3.312%，浸泡液浊度均在2 NTU左右；耐热胶黏剂不仅具有普通胶黏剂一样的黏合强度，且耐热、不溶于水，可用于耐热型纸吸管纸的黏合，且满足耐热型纸吸管纸的使用安全性能要求。     

金银花提取物对冷却肉中假单胞菌黏附性的影响

研究冷却肉中假单胞菌的黏附能力及金银花提取物的降黏附效果。结果表明：从15 份市售冷却肉中分离 得到46 株假单胞菌，经16S rDNA结合VITEK 2系统鉴定为恶臭假单胞菌22 株，占47.8%；荧光假单胞菌10 株，占 21.7%；铜绿假单胞菌6 株，占13.0%；浅黄假单胞菌8 株，占17.4%；33 株（71.7%）假单胞菌具有黏附能力，具有 强黏附能力的菌株占17.4%，其中恶臭假单胞菌数量最多；金银花提取物能够降低4 种假单胞菌的黏附能力，且对 恶臭假单胞菌5-3和铜绿假单胞菌5-1作用效果更强，作用效果与金银花提取物质量浓度有关；金银花提取物质量浓 度高于最小抑菌质量浓度（minimum inhibitory concentration，MIC）时，主要通过抑制菌体生长、减少胞外多糖产 生而降低假单胞菌的黏附能力；金银花提取物质量浓度低于MIC时，主要通过溶解菌体胞外多糖、增强通透性、降 低均匀度而降低假单胞菌的黏附能力。     

The impact of supplementing goats' milk with quinoa extract on some properties of yoghurt

This study investigated the impact of supplementing goats' milk with quinoa extracts, in the range of 5, 10 and 15 g/100 g on the milk fermentation. The properties of yoghurt produced from this milk, which include viscosity, microstructure and sensory acceptability, were assessed. The supplementation of goats' milk with quinoa extracts, particularly permeate extract, reduced the fermentation time and enhanced the viability of lactic acid bacteria. Supplementation of yoghurt with increased levels of quinoa extracts increased the apparent viscosity and changed the yoghurt protein matrix. Panellists highly accepted the yoghurt that contained quinoa permeate extract.     

分析比较两种不同方式制备的无色茶香提取物风味成分

目的分析比较膜过滤、减压蒸馏两种方式制备的无色茶香近水饮料的理化及风味品质。方法采用不同孔径膜过滤、减压蒸馏两种方式制备得到3个无色茶香水提取物,通过对其香气组分、咖啡因、茶多酚等风味品质理化分析并结合感官评定,寻找最合适的无色茶香近水饮料的制备方法。结果经分析鉴定, 3个样品共鉴定出44种香气成分,膜过滤方式中共检出26种、蒸馏方式中检测有28种。其中样品1香气成分以醇类和酮类为主,两者占总香气量的80.79%;样品2和样品3以酯类和醇类香气物质为主,这两类物质占总香气比分别为90.74%和91.60%。另外茶多酚、咖啡因和儿茶素在样品2中含量最高,样品1其次,样品3中均未检出。结论通过指标分析并结合感官风味评审发现,无色透明提取物样品2中含有较高的茶特性性成分,香气浓郁带有茉莉花香,滋味饱满带回甘,在3个试样中评价最优。综合评估认为采用膜过滤方式并选择适当孔径的膜及处理工艺,可以得到风味与品质兼备的无色茶香提取物。