油茶鲜果预处理方式对低温压榨油茶籽油品质的影响

为更 多地保留活性成分，提高油茶籽油品质，研究了油茶鲜果6种不同预处理方式(剥壳-摊晒、直接摊晒、堆沤-摊晒、剥壳-烘干、直接烘干、堆沤-烘干)对油茶籽主要成分以及低温压榨油茶籽油中3种理化指标(酸值、过氧化值、多环芳烃)和4种微量活性成分(维生素E、维生素K1、角鲨烯、多酚)的影响。结果表明：油茶鲜果预处理方式对油茶籽主要成分(脂肪、蛋白质、淀粉）影响不大;6种不同预处理方式对低温压榨油茶籽油的理化指标和微量活性成分均有一定的影响，其中剥壳-烘干处理油茶鲜果在油茶籽油的酸值、多环芳烃、维生素E、角鲨烯指标上较其他预处理方式存在一定优势。综上，采用剥壳-烘干对油茶鲜果进行预处理，可在一定程度上提高油茶籽油品质。 In order to retain more active components and improve the quality of oil-tea camellia seed oil, the effects of six different pretreatment methods of fresh Camellia oleifera fruit(shelling-spreading, direct spreading, retting-spreading, shelling-drying, direct drying, and retting-drying) on the main components of oil-tea camellia seed, as well as three physicochemical indexes (acid value, peroxide value, and polycyclic aromatic hydrocarbons) and four trace active components (vitamin E, vitamin K1, squalene, and polyphenols) of low-temperature pressed oil-tea camellia seed oil were studied. The results showed that the different pretreatment methods had little effects on the main components (fat, protein, starch) of oil-tea camellia seed, and had certain effects on the physicochemical indexes and trace active components of low-temperature pressed oil-tea camellia seed oil. The shelling-drying method had certain advantages over other pretreatment methods in acid value, polycyclic aromatic hydrocarbons, vitamin E, and squalene of oil-tea camellia seed oil. In conclusion, the shelling-drying pretreatment of fresh Camellia oleifera fruit can improve the quality of oil-tea camellia seed oil to a certain extent

应用^137Cs示踪技术破译黄土丘陵区小流域坝库沉积赋存的产沙记录

根据泥沙的137Cs和黏粒含量变化,厚28.12m的云台山沟坝库沉积剖面,区分出44次洪水沉积旋迴.剖面中部旋迴27的137Cs含量最高,加权平均值12.65Bq·kg-1,为1963年沉积;向上、向下137Cs含量逐渐降低,次顶部旋迴2.15Bq·kg-1,底部旋迴0.92Bq·kg-1.通过坝库修建、运行历史,旋迴泥沙137Cs含量的变化,次洪水产沙量和降水资料的对比分析,确定了这些洪水沉积旋迴的对应暴雨.云台山沟1960~1970年期间,共发生产沙洪水44次,产沙2.36×106m3.年产沙次数1~10次不等,1961~1964年为多雨年份,秋季降水多,年产沙洪水7~10次;1960,1965~1969和1970年为少雨年份,每年仅1~3次洪水.年均产沙模数1.29×104t·km-2·a-1,略高于甘谷驿水文站以上的延河上游的同期产沙模数1.11×104t·km-2·a-1,略低于相邻的纸坊沟1980年前的实测产沙模数1.40×104t·km-2·a-1.年产沙模数和汛期降水量(6~9月)相关较好

Novel Electrochemical Method for Synthesis of Nanostructured Materials of Noble Metals Based on Poly(N-Vinylpyrrolidone) (PVP)

以不同聚合度的聚乙烯吡咯烷酮(PVP)作为金纳米团簇的稳定剂和形状控制剂,应用电化学还原方法制备尺寸可控的金纳米晶体.借助PVP聚合物的动态伸缩和卷曲特性将电化学还原得到的金纳米粒子前驱体组装成线状和环状的纳米粒子聚集体,再由不稳定前驱体粒子的定向聚集制备厚度为几十纳米的金纳米棱柱.并用分步电化学还原法合成核壳结构的金银纳米复合粒子.本文为制备不同形状和结构的贵金属纳米结构材料提供了一种可行的电化学合成新方法.Gold nanocrystals with controllable size were synthesized through a simple electroreduction method using poly(N-vinylpyrrolidone)(PVP) of different polymerization degree as both stabilizer and shape-controller for gold nanoclusters.Individual gold nanoparticles spontaneously assembled into the wire-and ring-shaped nanoparticle aggregates depending on the PVP's dynamic stretching and curling,and precursor nanoparticles grew into flat,single-crystalline nanoprisms with thickness of dozens of nanometers based on the oriented aggregation between particles.Besides,core-shell Au/Ag nanoparticles were conveniently synthesized through two-step electroreduction of noble metal ions in the presence of PVPK30.The electrochemical synthetic method based on PVP provides a new path for preparation of noble metal nanostructured materials with different shape and structure.作者联系地址：山东大学化学与化工学院,山东师范大学理化分析测试中心,哈尔滨工业大学(威海)海洋学院,山东大学化学与化工学院,山东大学化学与化工学院,山东大学化学与化工学院 山东济南250100,山东济南250014,山东威海264209,山东济南250100,山东济南250100,山东济南250100Author's Address: 1,ZHANG Xiao-kai~2,HUANG Ming-hu~3,HUANG Shao-xin~1,FENG Xing-li~1,MA Hou-yi~*11.School of Chemistry and Chemical Engineering,Shandong University,Jinan 250100,Shandong,China,2.Analysis and Testing Center,Shandong Normal University,Jinan 250014,Shandong,China,3.School of the Ocean,Harbin Institute of Technology at Weihai,Weihai 264209, Shandong,Chin

Phase-Transfer Technique for Polymer-Protected Noble Metal Nanoparticles

依据聚乙烯吡咯烷酮(PVP)在水中的溶解度随温度升高而降低的特性,建立了将PVP保护的金、银、铂纳米粒子从水相转移到油相的简单而有效的相转移技术.方法是利用电化学还原法先于水溶液中制备粒度均匀的金属纳米粒子,然后向电化学合成后的金属纳米水溶胶中加入适量正丁醇,在搅拌条件下升温至80℃即可使金属纳米粒子从水相转移至有机相.纳米粒子的相转移效率很高,而且相转移后粒子在油相中分散很好,没有团聚现象发生.在此基础上进一步建立在油水混合体系电化学合成金属纳米粒子的实验方法,为收集纳米粒子和制备纳米粒子薄膜提供了新的有效途径.A novel phase-transfer method was developed based on the decrease of PVP's solubility in water with increasing temperature,by means of which PVP-protected gold,silver and platinum nanoparticles can be conveniently transferred from aqueous phase to 1-butanol phase.Monodispersed metal nanoparticles were electrochemically synthesized at first in the aqueous,and then 1-butanol of appropriate volume was added to the aqueous phase.Heating the oil-water mixture to 80 ℃ under vigorous stirring would make metal nanoparticles leave the aqueous phase and enter into the 1-butanol phase,with high phasetransfer efficiency and without aggregation between nanoparticles.An electrochemical method to synthesize metal nanoparticles in the oil-water mixtures was further established,which provides a new path for collection of nanoparticles and preparation of metal nanofilms.作者联系地址：山东大学化学与化工学院,哈尔滨工业大学(威海)海洋学院,山东师范大学理化分析测试中心,山东大学化学与化工学院,山东大学化学与化工学院,山东大学化学与化工学院 山东济南250100,山东威海264209,山东济南250014,山东济南250100,山东济南250100,山东济南250100Author's Address: 1,HUANG Ming-hu~2,ZHANG Xiao-kai~3, HUANG Shao-xin~1,PAN Wei~1,MA Hou-yi~*11.School of Chemistry and Chemical Engineering,Shandong University,Jinan 250100,Shandong,China,2.School of the Ocean,Harbin Institute of Technology at Weihai,Weihai 264209,Shandong,China;3.Analysis and Testing Center,Shandong Normal University,Jinan 250014,Shandong,Chin