柚子活性成分的提取及其功能研究进展

柚子不仅具有丰富的营养价值,而且具有重要的生物学功能。对柚子的有效部位进行简要说明,着重对柚子的活性成分及其生理功能进行详细阐述,并对其发展前景进行展望,以期为我国柚子资源的开发利用提供参考。     

次氯酸钠溶液中游离碱含量测定的改进

介绍了测定次氯酸钠溶液中游离碱含量的新方法,阐述了改进要点.     

Microbial quality of water in Barekese reservoir and feeder streams in Ghana

Concern is growing in Ghana about the high incidence of water‐related diseases and deaths resulting from use of water contaminated with microorganisms. This water often remains unsafe for human consumption because of inadequate decontamination of microbially infected water. Data are presented in this study on the microbial quality of Barekese reservoir, which is the main drinking water reservoir for the city of Kumasi and its environs (population = 2, 5 million), and nine feeder streams in its catchment. Water samples were collected from 13 sampling sites and analysed for Escherichia coli, total and faecal coliforms. Furthermore, 18 faecal coliform isolates were randomly selected from all sampling sites and confirmed as E. coli using Analytical Profile Index 20E system. Escherichia coli, total and faecal coliforms were enumerated using the most probable number method. Mean bacterial indicator numbers from all sampling sites ranged from 1.45 × 10⁴ to 9.50 × 10⁷ 100 mL^?1 for total coliforms, 1.60 × 10³ to 9.00 × 10⁵ 100 mL^?1 for faecal coliforms and 1.50 × 10¹ to 9.50 × 10³ 100 mL^?1 for E. coli. Indicator numbers exceeded the World Health Organization (0.100 mL^?1) for E. coli and Ghana Water Resources Commission‐Target Water Quality Range of 5–100 100 mL^?1 for total coliforms and 0.100 mL^?1 for faecal coliforms in water used for domestic purposes. The identified isolates in Barekese Reservoir and its feeder streams belonged to Serratia, Enterobacter, Citrobacter, Salmonella and Klebsiella genera. Bacterial numbers were significantly (P < 0.05) higher in the feeder streams, compared with Barekese Reservoir water. This finding indicates the feeder streams pose health risks to local communities that withdraw water from them. The results of this study highlight the urgent need to raise public awareness on the adverse effects of water‐quality degradation through improper waste disposal methods in order to decrease the cost of treating the reservoir water.     

Zooplankton as an indicator of trophic conditions in two large reservoirs in Brazil

The physical and chemical variables of the water, and the composition and structure of the zooplankton communities, in Três Marias and Furnas Reservoirs in Minas Gerais, Brazil, were compared to characterize these environments in relation to their trophic state. Higher values of electrical conductivity and chlorophyll‐a, total solids, suspended organic matter and total nitrogen concentrations were recorded in Três Marias Reservoir. Higher water transparency and nitrite and nitrate concentrations were observed in Furnas (P < 0.000). Higher zooplankton densities were always obtained in Três Marias Reservoir and, during the rainy period (P < 0.000), with mean values in the dry and rainy periods of 23 721 and 90 872 org m^?3, respectively, in Três Marias Reservoir and 9022 and 40 434 org m^?3, respectively, in Furnas Reservoir. Copepoda was the dominant group in both reservoirs, mainly the younger stages (nauplii and copepodids). Based on the absolute and relative values, the contribution of rotifers was higher in Três Marias Reservoir than in Furnas Reservoir. Although the Trophic State Index, based on water transparency and chlorophyll‐a and total phosphorus concentrations, indicated an oligotrophic state for both reservoirs, the higher densities of the zooplankton community in Três Marias Reservoir, as well as the predominance of cyclopoids and smaller‐sized species such as bosminids, characterized this environment as mesotrophic. Larger‐sized species such as calanoids, daphniids and sidids in Furnas Reservoir characterized the better water quality of this reservoir.     

染整用水的处理工艺及应用

利用临近河水资源通过处理，可大大降低生产成本。阐述印染用水浊度、色度、pH值、硬度、铁锰离子、耗氧量和总固体等指标对染色的影响，介绍河水处理的解决方案和染色用水常用处理工艺流程。     

新型锚杆激光指向仪在巷道掘进中的推广应用

介绍了YBJ-500(A)型隔爆激光指向仪在巷道施工中的安装调试方法和具体应用,以及分析仪器的指向精度极其仪器使用的注意事项。     

钢铁生产中钙镁化学分析方法的探讨

分析了目前钢铁生产中钙镁化学分析的各种类型，并对钙镁化学分析方法在实验过程中的差异作了一些有益的探讨。     

石油钻井指重表检定装置的研制

石油钻井指重表是石油钻井专用的检测仪器,近年来国内同行一直在寻找和摸索一种准确有效的检测方法。本文针对石油钻井指重表检定的特殊情况和要求,从检测方法、检测手段入手,研制了一套使用方便、有效的石油钻井指重表检定装置,对国内石油行业指重表检测方法的研究具有重要的促进作用。     

塔河油田油气成因和运移的氦同位素证据

塔里木盆地塔河油田是目前我国在海相碳酸盐岩层系中发现的最大油田。为明确勘探方向和目标，通过测试该油田原油伴生气的氦同位素组成，探讨了该油田的油气成因和运移问题。研究结果表明，该油田原油伴生气的³He/⁴He比值分布在2.99×10^-8~8.27×10^-8之间，平均为4.89×10^-8；R/Ra比值为0.02~0.06，平均为0.035。这反映了壳源成因特征，说明该油田油气在形成和运移聚集过程中缺乏地幔流体的参与。该油田原油伴生气中氦同位素组成在区域分布上具有一定的规律性，研究认为这种分布特征起因于油气运移过程中伴生气的扩散作用和水、油溶解作用的氦同位素分馏，因而氦同位素组成及其分布特征可能是一种可以表征油气运移情况的新指标。据此指标揭示出该油田的油气由南向北运移，说明油气主要来自该油田南部满加尔坳陷及其邻近地区的烃源岩区。     

Preparation,characterization, and morphology of on/off detection indicator based on rhodamine 6G-adamantanamine loaded onto nonwoven polyethylene terephthalate

Traditionally, food quality is evaluated by consumers through comparison of the production and expiration dates of the product. However, product shelf life cannot be the real and only parameter of food quality, especially within a variety of storage environments. Therefore, new indicators of food quality are needed to provide food safety to the consumer. In this work, we reported a detection indicator based on rhodamine 6G-adamantanamine and β-cyclodextrin (β-CD) polyelectrolyte cross-linked onto a nonwoven polyethylene terephthalate textile support, which can be used as the indication of food quality by means of the irreversible change of fluorescence. The relationship between the increase of fluorescence and pH variation was also reported. Considering food safety, a migration experiment was carried out using a food simulation system. When pH changed to 6.8, the evident fluorescence can be observed by naked eye at 650-nm excitation wavelength. β-CD can not only act as a good carrier of rhodamine 6G-adamantanamine but also enhanced the fluorescence to indicate whether rhodamine 6G-adamantanamine was loaded onto β-CD polyelectrolyte or nonwoven polyethylene terephthalate. After 250 h of migration experiment at 25°C, it was found that the fluorescent substances slightly migrated, and the migration under acidic conditions was almost negligible. The fluorescence enhancement performance and migratory behavior indicated that the material had the potential as a fluorescent intelligent indicator for food packaging.