分光计的调整研究

分光计装置结构精密,调整操作技术较复杂,使用时必须要按要求做到仔细熟练调整,才能获得较精确的实验结果。     

北京谱仪上D物理研究中的粒子鉴别

使用北京谱仪在质心系能量3.097 GeV和3.773 GeV附近采集的数据样本,研究了对D介子衰变产生的不同种类的带电粒子和中性粒子的准确鉴别问题。     

核酸碱基配对与错配的拉曼光谱——A-U与A-C的比较研究

采用激光拉曼光谱技术对碱基配对与错配形成的核酸复合物(即PolyA.PolyU和PolyA.PolyC)进行了研究,并比较了复合前后的光谱改变以及此二种复合物形态结构的差异.研究表明,在所研究的溶液环境下二者在分子构象和形成前后光谱改变的特征上都存在着一定的相似性;但在参与复合的两条单链结构改变和碱基氢键配位结构上存在明显差异.这对于需要准确预测配对碱基与非配对碱基的数目和种类的基因芯片测序技术来说无疑具有重要意义.     

金刚石薄膜的制备和结构分析

金刚石薄膜的制备与热丝温度、衬底温度、工作室压强及反应气体浓度有关,氢原子具有抑制石墨生长的作用,衬底的表面处理对金刚石薄膜的生长有很大影响。本文还试图用晶体生长和相变理论解释金刚石薄膜的生长过程。     

一种新的拉曼散射——表面增强拉曼散射

阐述了拉曼散射的原理,重点介绍了表面增强拉曼散射(SERS)的特点、增强原理、衬底特点以及最新进展.指出目前普遍接受的增强机理是电磁增强机制和化学增强机制同时存在,只是两者在不同实验体系中所占的比重不同.     

傅立叶变换型红外光谱仪中的双光路技术

分析了普通光谱测量技术的弊端,设计了一种新的双光路红外光谱测量技术。这种新的技术不仅可以同步测量背景和样品光谱,从而降低实验误差,提高实验灵敏度,而且在保证小角度反射光谱测量的基础上,方便地实现了大角度测量,增加了实验仪器的适用范围。     

B2H6分子声子态及声子间耦合的群论分析与Mathematica应用

利用群论和对称性分析的方法研究了具有D3d对称性构型的B2H6分子的声子态及其声子间耦合等问题。研究发现,B2H6存在5种不同的声子态,它们分别具有D3d群下的a1g、a1u、a2u、eg与eu对称性,其中a2u与eu具有红外活性,a1g和eg具有拉曼活性,而a1u是非活性的;在B2H6的声子态中只有eg是活跃的声子态;活跃声子态eg与eg之间的耦合作用将会产生耦合声子态a1g和eg;B2H6分子的电声耦合作用一定会导致B2H6分子发生杨-泰勒畸变,畸变致使B2H6分子从D3d对称性降低到C2h对称性。     

表面增强拉曼光谱检测系统在实验教学中的应用

根据表面增强拉曼光谱检测技术在医学研究中的一些研究方法和内容,设计和实践了一组适合本科低年级学生学习的教学实验,探索了科研仪器设备在教学实验中的应用的具体方法。实践表明,该实验有利于培养学生的实践能力、创新能力和科研能力。     

When Glass and Metal Corrode Together,VI: Chalconatronite

ABSTRACT

Chalconatronite, Na₂[Cu(CO₃)]₂·3H₂O, is formed as a corrosion product when copper alloys are exposed to sodium carbonate solutions in the air. This also happens when metals come into contact with corroding soda glass which forms alkaline surface films in reaction with humidity from clean air. More often, substantial amounts of formaldehyde are present indoors which react to formate via the Cannizzarro reaction and accumulate over time in the films. Twenty cases of chalconatronite (including two mentioned in the literature) are reported as occurring on heritage objects with glass in contact with copper alloys: Baroque reliquaries with set glass gems, enamel on metal (sixteenth century and a modern replica of intentionally unstable composition), Christmas tree glass baubles with wires, glass buttons with metal shanks, a glass figure with a wire support, miners’ lamps, and a glass framed daguerreotype. These confirmed identifications might help conservators in investigating similar cases to shed more light on the formation conditions.     

When Glass and Metal Corrode Together,V: Sodium Copper Formate

A sodium copper formate, first described in 2002, can also form on copper alloys with sodium originating from soda glass hydrolysis. The frequent occurrence (50% of 250 cases of glass-induced metal corrosion) is due to the presence of formaldehyde emissions in storage and its direct reaction to formate in the alkaline surface films. The compound can be produced without the presence of acetate when chalconatronite or metal coupons immersed in soda solution are exposed to formaldehyde vapours. The crystal structure, derived from X-ray powder diffraction, yielded the sum formula Cu₄Na₄O(HCOO)₈(OH)₂·4H₂O. Except for the absence of acetate in the structure, this is in good agreement with the 2002 publication. To assess which kind of combined glass/metal objects are affected, a number of large museum collections were surveyed. Sodium copper formate was detected as a corrosion product using mainly micro-Raman spectroscopy, for instance, on 18 painted Limoges enamels, eight glass vessels with metal mountings, glass beads on metal wire from 11 bridal crowns, nine Christmas tree balls with wire decoration, 40 pieces of jewellery with glass gems, three daguerreotypes, and one miniature with cover glasses.