电化学原位拉曼光谱的应用及进展

通讯联系人：田中群The applicat ion of in_situ Raman spect roscopy , part icularly surface enhanced Raman spectroscopy ( SERS) , in electrochemistry is reviewed, including electrosorption, elect roplating,corrosion, conduct ing polymers, batteries and nonaqueous media. Recent w ork on extending Raman study to t ransit ion metal surfaces as w ell as semiconductor surfaces are also outlined. The current advance in SERS study and the prospectus are also given.国家杰出青年科学基金,国家教委跨世纪人才基

电化学原位拉曼光谱的应用及进展

常规电化学研究方法是以电信号为激励和检测手段，它提供的是电化学体系的各种微观信息的总和，难以准确地鉴别复杂体系的各反应物、中间物和产物，并解释电化学反应机理．近年来，由谱学方法（以光为激励和检测手段）与常规电化学方法相结合产生的谱学电化学技术得到迅速...作者联系地址：厦门大学化学系固体表面物理化学国家重点实验

南瓜粉的酶法制备及营养成分分析

用菠萝蛋白酶对南瓜进行酶解,研制生产南瓜粉,实验结果表明:0.04%菠萝蛋白酶pH 6.35条件下,50℃酶解5h为最佳酶解条件.并对南瓜粉进行成分分析,其水分、灰分、脂肪、糖类物质、蛋白质、果胶含量分别为8.34%,5.61%,0.41%,58.46%,13.24%,1.82%.另外比较了南瓜粉与灵芝粉和莲子粉中的一些金素元素含量.研究结果为南瓜中有效营养成分的提取和开发利用提供了科学依据

没食子酸衍生物对蘑菇酪氨酸酶的抑制机理

蘑菇褐变过程主要是由于其酪氨酸酶的催化作用引起的,寻找该酶抑制剂在食品保鲜和储藏中的应用具有重要的意义.作者在实验中,发现没食子酸十二烷基酯和没食子酸香叶酯对蘑菇酪氨酸酶有较强的抑制作用,测定它们抑制蘑菇酪氨酸酶二酚酶的酶活力下降50%的抑制剂浓度(IC50)分别为1.55和0.25 mmol/L.显示没食子酸香叶酯的抑制作用强度是没食子酸十二烷基酯的6倍.研究了这两种抑制剂对蘑菇酪氨酸酶的抑制作用动力学,结果表明:没食子酸十二烷基酯和没食子酸香叶酯对酶的抑制作用均表现为可逆反应,前者为反竞争性,其抑制常数KIS为0.636 mmol/L;而后者为混合型,抑制常数KI和KIS分别为0.133和0.453 mmol/L

Study on the spatial and temporal variation of surface chlorophyll a in Taiwan Strait and its adjacent waters

从物理过程和营养输送方面讨论了2006~2007年台湾海峡及其邻近海域表层水叶绿素A含量的时空变化特征及其调控因素.结果表明,台湾海峡表层水体从南至北叶绿素A含量的季节变化存在着明显差异.在北部海区叶绿素A含量平均值以春季居高,冬季最低;中部海区以秋季最高,夏季最低;南部较反常,以冬季最高,夏季最低.浙闽沿岸流、海峡暖流及上升流所造成的营养盐输入方式的差异可能是决定海峡叶绿素A含量季节分布南北差异的关键因素.分析结果还表明,春、夏季叶绿素A含量的分布在南部和北部海域均主要受营养盐限制,秋季叶绿素A含量在南部和北部海域分别主要受到磷酸盐含量和水温的影响,冬季叶绿素A含量在南部和北部海域分别主要受到硝酸盐含量和水温的影响.Spatial and temporal variation of chlorophyll a and their environmental factors in surface water of Taiwan Strait and its adjacent waters is discussed based on the physical process and nutrients transportation in 2006 and 2007.The results showed that seasonal variation of chlorophyll a was different remarkably from the south to the north in Taiwan Strait.The maximum mean of chlorophyll a appeared in spring and the minimum in winter in northern waters,but in the middle waters the maximum mean of chlorophyll a appeared in autumn and the minimum appeared in summer.It was abnormal in the south that the maximum value appeared in winter and the minimum in Summer.The different nutrients transportation of surface water and upwelling water by Zhe-Min along-shore water and Taiwan warm current may control the distribution of chlorophyll a in the southern and northern Taiwan Strait.The analysis also showed that nutrient concentrations was the factor that controlled the distribution of chlorophyll a in spring and summer in the southern and northern Taiwan Strait.In autumn,chlorophyll a contents were mainly influenced by temperature in northern Taiwan Strait while phosphate in southern Taiwan Strait.In winter,chlorophyll a contents were mainly influenced by temperature in northern Taiwan Strait while nitrate in southern Taiwan Strait.国家908专项基金资助项目(908-01-ST06

RV减速器摆线轮齿廓修形润滑性能分析

考虑润滑脂的压黏特性及热效应，建立摆线轮齿与针齿之间的线接触脂润滑热弹流数值模型，求得该模型的完整数值解，得到了脂膜压力分布、温升分布及脂膜形状；结合摆线轮齿廓，分析了修形方式及修形量对脂膜压力、脂膜形状、脂膜温升和摩擦损失功率的影响。结果表明，随着修形齿廓与摆线轮理论齿廓径向间隙的增大，摩擦损失功率增加，最小脂膜厚度先增加后减小；在修形齿廓与摆线轮理论齿廓同一径向间隙的条件下，反弓齿廓修形方式的润滑性能最好，正等距加正移距的组合修形方式次之，负等距加负移距的组合修形方式润滑性能最差。研究结果为考虑润滑性时RV减速器摆线轮齿廓修形提供了一种新的方法

广西柳州白莲洞石器时代洞穴遗址发掘报告

白莲洞石器时代洞穴遗址,位于广西柳州市东南郊都乐生产大队的白面山南麓,东经109度25分37秒,北纬24度12分54秒,距市中心约12公里(图一,1)。1956年,中国科学院古脊椎动物与古人类研究所的裴文中、贾兰坡两教授率领的华南调查队在广西调查巨猿和人类化石时发现了白莲洞遗址。调查队在白莲洞内的扰乱土层中发现了多量的软体动物外壳、少数鹿牙等化石和用砾石打制的石器,还发现了一件残破的骨锥

青藏高原高寒草原生态系统土壤碳氮比的分布特征

利用67个样点数据,研究了青藏高原高寒草原生态系统土壤碳氮比的分布特征。结果表明:(1)在水平方向上,土壤碳氮比呈现出西北高、东南低的总体态势和斑块状交错分布的格局,碳氮比的高值区主要集中在藏北高原腹地和喜马拉雅山北麓湖盆区,不同草地型和不同自然地带土壤碳氮比差异显著;(2)土壤剖面自上而下,不同草地型碳氮比可分为低-高-低型、由高到低型、由低到高型、高-低-高-低型和高-低-高型等5个类型。表土层(0—20 cm)与底土层(30—40 cm)土壤碳氮比差异显著;(3)土壤碳氮比与与最冷月均气温、年均蒸发量、年均相对湿度和土壤全氮含量呈极显著正相关关系,而与年均日照时数、年均气温、速效钾含量呈极显著负相关关系,这些环境因素对土壤碳氮比影响从大到小的顺序是年均相对湿度>年均日照时数>最冷月均气温>年均气温>年均蒸发量>土壤全氮含量>土壤速效钾含量

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel