Moisture Uptake Behavior,Antibacterial Property,and Heat of Sorption of Nano Silver-Loaded Calcium Alginate Films

This work describes preparation, characterization, and a moisture uptake study of silver nanoparticle-loaded calcium alginate films. The equilibrium uptake data was interpreted by various isotherm models. In the lower moisture content range of 0.02 to 0.06, the enthalpy of sorption (ΔH) and differential entropy (ΔS) were 25.25 to 4.82 kJ/mol and 0.07521 to 0.01371 kJ/mol/K, respectively. There was fair correlation between ΔH and ΔS values. Finally, the higher value of isokinetic temperature, T_B (i.e., 336.77), as compared to the harmonic mean temperature, T_m (i.e., 302.05), indicated that moisture uptake mechanism was enthalpy driven.     

Structural and luminescence enhancement properties of Eu3＋/Ag nanocrystallites doped SiO2-TiO2 matrices

We reported here the structural and optical characterisation of silver nanocrystallites/Eu3+ :SiO2-TiO2 matrices synthesised through sol-gel route. Structural characterisations were done by using energy dispersive spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), atomic force microscope (AFM) and transmission electron microscopy (TEM) measurements and optical characterisations were performed by absorption and emission spectroscopy. The TEM and XRD measurements confirmed the presence of nanocrystals. A broad absorption band was observed due to surface plasmon resonance of silver nanocrystals. The effect of silver nanocrystals on the emission spectrum of Eu3+ doped SiO2-TiO2 matrices was discussed. An attempt was made to explain this fluorescence enhancement by invoking phenomena such as energy transfer, asymmetry ratio, surface plasmon, surface roughness, crystallinity and grain boundary. Our analysis, based on the experimental results, suggested that all the phenomena except crystallinity and grain boundary had favourable effects on fluorescence enhancement. We also estimated the relevant parameters associated with the phenomena that affected the fluorescence emission from the Eu3+ ions in the matrix. It was seen that the theoretical estimate of fluorescence enhancement agreed well with the experimental estimate.     

多壁碳纳米管修饰电极阳极溶出伏安法测定痕量银

利用多壁碳纳米管修饰玻碳电极,通过优化支持电解质及pH值、修饰剂用量、富集电位及时间等测定条件,建立了测定痕量银的线性扫描阳极溶出伏安分析法。在pH 4.0的NaAc-HAc缓冲液中,－0.10 V电位下富集5 min后,于0.46 V处出现一灵敏度高、峰形较好的银阳极溶出峰,溶出峰电流与Ag+浓度在3.0×10-8 ~5.0×10-5 mol/L的范围呈良好的线性关系,Ag+的检出限为1.0×10-8 mol/L,在选定的最佳实验条件下一些常见的金属离子几乎不干扰银的测定。该法用于环境水样及锌合金样品中痕量银的测定,平均回收率在96% ~ 103%之间。     

Control the Silver Content in the Preparation Process of Platinum Group Anti-cancer Drugs

In order to control the silver content in the preparation process of platinum group anti-cancer drugs, we put two kinds of color reagent to color in the production process of the platinum anti-cancer drugs by UV spectra measurement to control drugs production of platinum anticancer, thus we could control the silver content in the drugs so that it meets the pharmacopoeia standards of US and European     

电极银浆银粉特性对瓷介电容器性能的影响

采用不同粒径和比表面积的银粉制备了电容器电极银浆,研究了在高温烧结条件下银粉的物理化学参数对BaTiO_4瓷介电容器电容量与电容损耗的影响。利用比表面积测试仪(SSAA),激光粒度仪(LPSA),场发射扫描电子显微镜(FESEM)表征分析了样品比表面积、粒度和形貌,并进行了电容测试。结果表明,在830℃的烧结温度下选用高比表面积(7.7m~2/g)的类球型超细银粉,其制成的银浆在烧结后形成的银膜最致密,且表面最平整,选用此银浆烧结电极的电容器平均电容为9.17nF,电容损耗为0.68%。表明选用更高比表面积银粉的银浆,烧结成的银电极更加致密,电容器的性能更优。     

The availability of soluble oxalates in stir‐fried silver beet (Beta vulgaris var. cicla) leaves eaten with yoghurt

Silver beet (Beta vulgaris var. cicla) leaves contain oxalates, and the addition of yoghurt, a food rich in calcium, to stir‐fried leaves was investigated as a way of reducing the soluble oxalate content. Fourteen participants ingested 115 g stir‐fried silver beet leaves with or without standard yoghurt and low‐fat yoghurt, respectively. Stir‐fried silver beet leaves contained 209.1 ± 0.1 mg of total oxalates per meal fresh weight (FW) and 109.2 ± 0.1 mg of soluble oxalates per meal FW. The proportion of soluble oxalates was reduced from 52% to a mean of 30% of the total oxalates when standard yoghurt or low‐fat yoghurt was added. The mean absorption of oxalate was determined by measuring the output of oxalate in the urine over a 6‐h period following ingestion of the meals. The mean absorption of oxalate from stir‐fried silver beet leaves was 2.41%, which reduced to 1.10% and 0.89% when consumed with standard yoghurt and low‐fat yoghurt, respectively.     

Antimicrobial packaging of raw beef,pork and turkey using silver‐zeolite incorporated into the material

This study determined the efficacy of silver‐zeolite impregnated into wrapping paper to reduce the bacterial growth on raw beef, pork and turkey cuts. This was compared with that of regular butcher paper. The samples were inoculated with Pseudomonas putida (psychrotrophic spoilage bacterium) and stored on 4% silver‐zeolite and regular butcher paper for up to 4 days at 4 °C and 10 °C. Results showed that P. putida on the beef, pork and turkey samples did not increase in numbers after exposure to all paper packaging at 4 °C during the 4 days of storage. At 10 °C storage temperature, logarithmic growth patterns for the organisms were seen on all paper packaging. However, the growth rate was slower for the organisms on the silver‐zeolite paper. Storage on the silver‐zeolite paper accounted for one log cfu/sample mean reduction in viable cell count for the beef, pork and turkey samples when compared with the samples stored on the butcher paper at 3 days.     

银阳极泥氯化浸出回收金工艺研究

研究了银阳极泥氯化浸出回收金工艺。实验结果显示,在盐酸1.5 mol/L、硫酸0.75 mol/L、氯化钠35 g/L、氯酸钠与银阳极泥中金的质量比mNaClO