Porous silicon thin film as CO sensor

This work presents the electric behavior of porous silicon (PS) thin films when the material's surface is exposed to carbon monoxide. PS thin films were fabricated by the electrochemical anodization method of Si-c (1 0 0) substrates with resistivity . The samples were prepared at 20 min anodization time and anodization current. Aluminum electrodes were deposited on the surface of the material by high vacuum evaporation, such that the electric conduction was parallel to the substrate's surface. The detector was placed in vacuum during 1 h and then CO was allowed into the vacuum chamber. Measurements of the I-V characteristic were carried out at atmospheric pressure, in vacuum and with CO. Changes in the resistance of the material, of about MΩ, were observed in the different samples, indicating that the material is sensitive to the presence of CO and therefore suitable as gas sensor.     

扬州漆器家具——第23届深圳国际家具展系列报道

扬州漆器源于战国,兴于汉唐,盛于明清。其工艺齐全、技术精湛、风格独特、驰名中外,是中国传统的工艺品种。早在秦汉时期,扬州彩绘和镶嵌漆器制作工艺就有相当高的水平,扬州北郊天山汉墓、北京老山汉墓、长沙马王堆汉墓出土的文物中都有扬州漆器的早期作品;唐代扬州漆艺还被鉴真大师传播至日本;到明清时代,扬州业已成为全国的漆器制作中心,盛极一时。     

Synbiotic potential of carrot juice supplemented with Lactobacillus spp. and inulin or fructooligosaccharides

BACKGROUND: The influence of the addition of two probiotic strains, Lactobacillus rhamnosus and Lactobacillus bulgaricus, and the prebiotic components inulin and fructooligosaccharides on carrot juice was investigated in order to evaluate the possibility of producing a functional vegetal beverage. RESULTS: Both bacterial strains were capable of growing in carrot juice, reaching nearly 5 × 10⁹ colony‐forming units after a 48 h fermentation, and the pH was reduced to 3.5–3.7 or below. The viable cell counts of the two lactobacilli in the fermented juice after 4 weeks of storage at 4 °C, demonstrated good survival of the two strains at low pH. Some biochemical characteristics of the fermented juice, such as β‐carotene content and antioxidant activity, were also preserved, indicating that the metabolism of the Lactobacillus spp. did not degrade these nutritional components after 4 weeks of storage at 4 °C. The positive effect was more evident when the juice was inoculated with Lactobacillus rhamnosus. The presence of inulin and fructooligosaccharides did not alter the cell counts or the biochemical characteristics of the fermented juice. CONCLUSION: We propose this as a health juice and functional beverage for vegetarians or consumers who are allergic to dairy products. Copyright © 2008 Society of Chemical Industry     

Some aspects of the modeling balanced fetacidic structure in sprets

Information about the development of a method of fatty basis of food inverse emulsion (spread) modeling is given in the article. Theoretical substantiation of creation of a balanced fatty product of functional purpose is described in the article. Practical research results of spread fatty basis creation from palm, soya and rape oil are presented.     

Pectin methylesterase in Citrus bergamia R.: purification, biochemical characterisation and sequence of the exon related to the enzyme active site

Three forms of pectin methylesterase (PME) were purified, from bergamot fruit (Citrus bergamia R.), to homogeneity by ion-exchange and affinity chromatography. The isoforms, named PME I, PME II and PME III, according their elution order on a heparin–sepharose column, were characterized for their relative molecular mass, activity kinetic parameters and thermostability. The molecular mass was estimated to be 42 kDa for the three forms, and the apparent K_m values for citrus pectin were 0.9 mg/ml for PME I and 0.5 mg/ml for PME II and PME III. The optimum pH values lie within the range 6.5–9.0, depending on salt concentration. Thermal behaviours of the three PME isoforms were studied in a temperature range from 65 °C to 80 °C with the less abundant PME I isoform showing a higher heat resistance. Moreover, the complete exon 2 sequence of PME gene was acquired (GenBank accession no. DQ458770) using a PCR-based approach on well-known Citrus genomic DNA present in the NCBI database.     

Phenolic composition and biological activities of Salvia halophila and Salvia virgata from Turkey

The aerial parts of Salvia halophila and Salvia virgata were subjected to Soxhlet extraction with different solvents such as n-hexane, ethyl acetate, methanol, and aqueous methanol (50%). Plants were also extracted with water under reflux. The effects of the extracts were studied in p-benzoquinone-induced abdominal constriction test for the assessment of antinociceptive activity and carrageenan-induced hind paw edema and 12-O-tetradecanoyl-13-acetate (TPA)-induced ear edema models in mice for the anti-inflammatory activity. The extracts were analysed using a HPLC–PDA method. Results showed that methanol extract of S. virgata significantly inhibited carrageenan-induced paw edema and p-benzoquinone-induced abdominal constriction at 100 mg/kg dose, while it showed no effect in the TPA-induced ear edema. On the other hand, the other extracts did not show any inhibitory antinociceptive and anti-inflammatory activities in these in vivo models. Rosmarinic acid was found as main constituent in the extracts, while caffeic acid and luteolin derivatives were also detected.     

Postmortem changes in the adductor muscle of Pacific lions-paw scallop (Nodipecten subnodosus) during ice storage

Postmortem biochemical, chemical, and physical changes of the adductor muscle of Pacific lions-paw scallop were studied during a 15-day storage period at 0 °C (ice). Content of ATP and breakdown products, K value, pH, trimethylamine, total volatile bases, water-holding capacity, colour, and texture changes were examined. K value increased logarithmically (r² = 0.95) from an initial value of 40.3–79.7% on day 15. The spoilage indicators trimethylamine and total volatile bases increased from 15.6 to 30.7 and 1.3 to 6.8 mg N/100 g of sample, respectively, which indicated spoilage at the end of the storage period. Texture, colour, and pH were not affected; however, water-holding capacity decreased significantly, from 96.0% on day 1 to 86.0% on day 15. Overall results indicated that quality of Pacific lions-paw scallop adductor muscle was maintained during at least 12 days of ice storage.     

西藏：雪域甘泉铸丰碑

这是一个无论谁经历了都会铭刻在心的场面。通水那天．村民们一大早就起来。在水龙头上系上洁白的哈达,男女老少连续数日盛装载歌载舞,家家户户端着酥油茶、青稞酒．排着长长的队伍虔诚地向技术员敬献哈达,表达心中的谢意。     

反应溅射AlN薄膜的动态特性

反应磁控溅射方法制备AlN薄膜是一种很普遍的方法,但采用该方法制备时,各个参数相互作用使过程复杂化.为了增强对该过程的理解,建立了反应溅射过程的动态模型.应用该模型分析了当氮流量增加或减少时,过程中的各个参数随时间变化的瞬态行为.计算出的溅射参数与实测值相符.模型清楚地表明,过程的初始状态对其动态行为有显著的影响.     

螺旋槽式牵引泵过渡流态抽气特性的直接蒙特卡洛模拟

为研究螺旋槽式牵引分子泵(DMP)过渡流态下的抽气特性,采用直接模拟蒙特卡罗(DSMC)方法对抽气通道内的流动规律进行了数值模拟.通过数值模拟,考察了抽气通道几何参数:入口、出口槽深,槽长,螺旋升角以及螺旋槽数量与泵抽气特性参数:传输几率的关系.模拟结果表明:增加抽气通道入口槽深可提高泵的抽速;出口槽深、螺旋倾角均存在最佳值,可获得大的抽速和压缩比;延长槽长、增加槽数对抽速影响不大,可以提高压缩比.本文的研究结果表明,直接模拟蒙特卡罗方法可以较好地模拟牵引分子泵三维抽气通道内过渡流态的流动特性,可用于优化设计抽气通道几何参数,提高牵引分子泵的抽气性能.