紫外扫描式水质COD测量技术与仪器研制

介绍了一种基于紫外全波段扫描的水质化学需氧量（COD）测量技术以及运用该技术设计开发的在线COD测量仪器.该仪器采用嵌入式微机系统实时采集与计算由紫外分光扫描系统得到的多个紫外吸光度，运用反相传播（BP）神经网络建立紫外吸光度和COD的数学模型.在实际使用时利用该模型的Levenberg-Marquardt快速算法，根据实际水样的吸光度值可以快速推算出水样的COD值.实验结果表明，该COD测量仪器具有测量精度高、无二次污染等特点.     

Selection of NF membrane to improve quality of chemically treated surface water

The requirement for higher quality drinking water necessitates the application of more efficient water treatment techniques. Nanofiltration is one promising option for enhanced water treatment, for example, in enhanced organic matter removal. The characteristics of different nanofiltration membranes vary remarkably, and the selection of a membrane has to be made according to the requirements of an application. In this study six nanofiltration membranes (NF70, NF255, NTR-7450, NTR-7410, Desal-5 and TFC-S) were evaluated in improving the quality of chemically pre-treated surface water in a pilot-scale process. The results indicate that the membrane with high organics removal and slightly reduced ion removal characteristics (NF255) performed best in terms of product water quality as well as membrane productivity and fouling. The most permeable membrane (NTR-7410) suffered intensive fouling and insufficient product water quality. An interesting finding was that the permeates of all the tested membranes possessed a significant potential for microbial growth, despite the low nutrient contents.     

Thermal, Optical, and Electrical Properties of Gel Grown ZMTC

The bimetallic thiocyanate of the group IIB divalent d¹⁰ ions Zn²⁺ and Hg²⁺ having unique characteristics: The pale color and high thermal stability—Zinc Mercury tetrathiocyanate (ZMTC) is chosen for growth and study. ZMTC is grown in silica gel by chemical reaction method and characterized by single crystal XRD, FTIR, FT-Raman, UV-Vis-NIR, NLO, TGA/DTG, DSC, AC conductivity, and dielectric studies. It has wide transparency window and possesses high second harmonic generation efficiency. Its thermal stability is very high. The dielectric permittivity of this material is very low.     

连翘花黄色素的提取及其对光热稳定性的研究

研究了连翘花中黄色素的提取方法 ,并对色素溶液在光照及加热等条件下的稳定性进行了初步研究。结果表明 :该黄色素易溶于乙醇、乙醚、乙酸乙酯等有机溶剂。当选用乙醇为溶剂时 ,色素提取的最佳条件为 :在 70℃、用 1g干花加 10 0mL体积分数为 95 %的乙醇的料液比浸提 3次、每次浸提 2h ,可将色素基本提取完全。该色素对强光的稳定性很差 ,而对弱光及热有较好的稳定性。不同波长的光对色素稳定性的影响也不相同。     

Changes in strawberry phenolics, anthocyanins, and antioxidant capacity in response to high oxygen treatments

Changes in fruit quality, decay, phenolic and anthocyanin content, and antioxidant capacity of strawberries (Fragaria × ananassa Duch. cv. Allstar) stored under air and high oxygen atmospheres at 5 °C were investigated. Freshly harvested strawberries were placed in jars and ventilated continuously with air or with 40, 60, 80, or 100 kPa O₂ at 5 °C for up to 14 days. Samples were taken initially, and after 3, 7, 10 and 14 days of storage. While fruit quality parameters such as titratable acidity, total soluble solids and surface color were only slightly affected by differing levels of O₂, the higher oxygen concentration treatments significantly reduced decay. Oxygen concentrations higher than 60 kPa also promoted increases in ORAC values, total phenolics and total anthocyanins as well as individual phenolic compounds analysed by HPLC during the initial 7 days of storage. However, this effect diminished with prolonged storage. No significant differences in ORAC values, total phenolics, total anthocyanins, or the individual phenolic compounds were observed among the high O₂ and air-stored fruits after 14 days of storage. These results indicate that high oxygen treatments exert the most effects on fruit quality and antioxidant capacity of strawberry fruit in the first 7 days of storage.     

Use of nanoparticles to make mineral oil lubricants feasible for use in a residential air conditioner employing hydro-fluorocarbons refrigerants

The application of nano-fluids in refrigerating systems is considered to be a potential way to improve the energy efficiency and reliability of HVAC&R facilities and to make economic the use of environment-friendly refrigerants. In this paper, we report a method that uses nanoparticles to enhance the energy efficiency of retrofitted residential air conditioners (RAC) employing HFCs as alternative refrigerants. The reliability and performance of RAC with nanoparticles in the working fluid have been investigated experimentally. A new mineral-based nano-refrigeration oil (MNRO), formed by blending some nanoparticles (NiFe₂O₄) into naphthene based oil B32, was employed in the RAC using R410a as refrigerant. A method showing how to disperse the NiFe₂O₄ nanoparticles in the mineral oil refrigeration lubricants is presented together with an investigation of their stability. The solubilities of the new MNRO in R134a, R407C, R410a and R425a were measured. The performances of the RAC, such as the cooling/heating capacity, the power input and the energy efficiency ratio, were determined. The results indicate that the mixture of R410a/MNRO works normally in the RAC. The cooling/heating EER of the RAC increased about 6% by replacing the Polyol-Easter oil VG 32 lubricant with MNRO.     

催化裂化汽油组成对其储存安定性的影响

 通过对催化裂化（FCC）汽油组成、诱导期、吸光度等性质指标的跟踪测试，考察了影响FCC汽油安定性的主要因素。结果表明，FCC汽油中除按产品质量要求严格控制含量的烯烃、总硫及硫醇是影响FCC汽油不安定的主要因素外，共轭二烯烃的存在严重影响FCC汽油的储存安定性，含氮化合物是油品变色的关键物质，而大部分酚类化合物具有抗氧化性，它们的存在有利于延长氧化变质诱导期，但对FCC汽油生胶、变色具有酸性催化剂作用。酚含量越多的FCC汽油，其诱导期越长，但油品变色也越快。FCC汽油的酚含量较高（＞200μg/g）时，其诱导期随着二烯值的增大而缩短，储存吸光度随着二烯值、碱性氮含量的增大而增加；酚含量较低（＜120μg/g＝时，汽油颜色稳定，二烯值、碱性氮含量的变化对储存吸光度影响不大，二烯值小至0.7μg/g也可导致诱导期缩短。通过优化催化原料和操作条件、优化调合和添加抗氧防胶剂等措施，可有效地提高FCC汽油的储存安定性。     

Changes in the catechin and epicatechin content of grape seeds on storage under different water activity (aw) conditions

Storage effect on antioxidant content and capacity of grape seeds under different a_w conditions (a_w 0.33; 0.53; 0.75/50 days, 25 °C) was examined. Total phenol content (determined by the Folin–Ciocalteu method) decreased during storage though changes were trivial for samples stored at 33% or 53% RH. High level of humidity (75%) accelerated degradation and resulted in a ∼50% reduction of total phenol content. Minor loss of the DPPH radical scavenging activity (%RSA) of the extracts was observed. Catechin and epicatechin content monitored by RP-HPLC was reduced during storage, particularly at 75% RH. Epicatechin content proved to be less sensitive to water activity conditions than catechin content. Results of various in vitro assays (Folin–Ciocalteu, FRAP, DPPH, ABTS, CBA, ORAC and copper induced liposome oxidation) did not support difference in terms of resistance to oxidation. Based on the continuous release of gallic acid, our finding was related to hydrolytic reactions. Control of a_w of grape seeds can be of practical importance for the wine industry.     

热处理对苦荞麦粉总抗氧化能力的影响

采用分光光度计法和抗氧化能量指数法对来自重庆市城口县的苦荞麦粉中总黄酮含量和抗氧化能力进行了分析。样品加热(100℃,20min,样品:水=1:2,w/v)前后,总黄酮含量为83.52mg芦丁当量/100g干重和67.38mg芦丁当量/100g干重,ORAC值为76.45μmol TE/g干重和63.93μmol TE╱g干重,损失分别达到19.32％、16.38％,呈显著差异(P<0.05)。但热处理前后的苦荞麦粉都表现出良好的抗氧化性。     

Fruit‐based functional foods II: the process for identifying potential ingredients

Developing functional food products requires a structured approach for screening potential ingredients. Using the development of a product with antioxidant properties as a model, eight fruit juice concentrates were screened, including New Zealand fruits. The total phenolic content and the antioxidant capacity, using chemical‐based assays (ferric reducing antioxidant power and oxygen radical absorbance capacity assays), were determined. The potential to protect against oxidative stress in Jurkat cells was also determined. Results indicate that the total phenolic content and antioxidant capacity in chemical‐based assays were strongly correlated. However, the total phenolic content did not dictate the level of protection from oxidative stress in this cell‐based model, suggesting that the type of phenolic compounds present and interactions between them may be important, although the activity of other compounds, such as vitamin C or carotenoids, may also be implicated. This model for screening ingredients may be used to design synergistic combinations of ingredients, and results may provide supportive evidence in the development of functional foods for this and other health targets.