不同颜色蚕豆的红外光谱研究     

董盈红 《保山师专学报》2012,31(2):5-6

蚕豆是世界上第六大食用豆类作物,具有较高的营养价值和药用价值。蚕豆常见的颜色有白色和绿色,两者在口感上稍有区别,在经济价值上也不同,利用傅里叶变换红外光谱对同一产地同一年份的两种颜色的蚕豆进行光谱研究。结果表明,两种颜色的蚕豆在子叶的吸收峰上有区别。根据红外光谱的谱峰形状和位置,可以判断两种蚕豆的主要化学成分。利用该方法可以快速、简捷地区分两种蚕豆。  相似文献   

乙醇玻璃化转变的介电谱研究     

张尚  鹿桂花  张武智  周兰兰  赵怀芳  张惠珍  周恒为 《新疆教育学院学报》2012,(2):118-120

文章采用介电谱方法对升温过程中乙醇的复介电常数实部ε’和虚部ε″随温度T的变化进行了测量。结果表明,升温过程中在100K～180K的温度范围内ε’主要有两个变化过程Kα和Cd,而ε″也有两个变化过程Pα和Ld。  相似文献   

表面增强拉曼光谱检测系统在实验教学中的应用     

吴宝平  曲典  王燕  陶蔷  刘文艳  满梓焱 《实验技术与管理》2014,31(5):55-57,70

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。  相似文献   

Light-induced color changes and chemical modification of treated and untreated chestnut wood surface     

none 《文物保护研究》2013,58(2):131-139

Abstract

The aim of this work is to study the surface modifications of chestnut (Castanea sativa Mill.) wood by reflectance spectrophotometry and Fourier transform infrared spectroscopy (FTIR) in order to understand the mechanisms that cause changes and to suggest possible solutions to avoid degradation phenomena. The experimental data were statistically treated to evaluate their significance. Concerning the surface protection of wood, starting from the results obtained by testing different commercial products, attention was focused on a novel organic preservative/consolidant product (Linfoil^®) that has attracted great interest in the field of conservation of wooden artifacts. Color monitoring showed that wood surface color undergoes an important variation due to photoirradiation, occurring within the first 24 hours and mainly due to L* decrease and b* increase. Though the protective treatment modifies wood color, nevertheless the product tested seems to protect the wood surface by reducing photoyellowing. FTIR analysis indicated that irradiation caused the degradation of lignin and increased the concentration of the chromophore groups on the wood surface. Changes in the chromaticity coordinates can be linked to the degradation of lignin and to increase of the concentration of carbonyl groups.  相似文献   

pH对黄芩苷与牛血清白蛋白相互作用的影响     

高平章  曾炜  黄金水  吴洪 《泉州师范学院学报》2013,(6):9-13

运用荧光光谱法研究pH对黄芩苷与牛血清白蛋白（BSA）相互作用的影响,结果表明：黄芩苷浓度的增加引起BSA在345am处荧光有规律地猝灭．荧光猝灭光谱及Stem—Volme方程分析发现,在pH为2．5、4．5和7．4体系中均为静态猝灭,且两者猝灭常数随pH增加而增加;Lineweaver—Burk双倒数方程计算pH7．4、温度为290K和310K下,黄芩苷和BSA的结合常数K分别为：K_（290）K=1．2894×10。L·mol^（-1）和K。。：1．0979×10。L·mol^（-2）由热力学参数确定黄芩苷与BSA之间的作用力类型为静电作用力．同步荧光光谱表明,黄芩苷使BSA芳香性氨基酸（Trp,Tyr）残基微环境的变化．  相似文献   

近红外光谱术测量肌氧含量拐点方法的比较     

田庆平  张中兴  王帮德  龚辉 《北京体育大学学报》2011,34(1):58-60

随着运动强度逐渐增大,近红外光谱术测量的肌氧含量发生非线性变化的"拐点"可用于评价无氧阈。对赛艇运动员做渐增负荷运动时的肌氧含量和呼吸参数的变化进行了研究,旨在比较两种确定肌氧拐点的方法:1)基于氧合血红蛋白和还原血红蛋白的相对浓度差Δ[O2Hb-HHb]的变化趋势进行判断;2)利用还原血红蛋白的相对浓度Δ[HHb]的变化趋势确定。研究发现,这两种方法确定的肌氧拐点都与通气无氧阈显著相关(r=0.980,0.965;p<0.001);且两者间高度相关(r=0.985;p<0.001),无统计差异(p>0.05)。结果表明,这两种方法确定的肌氧拐点都可用于评价无氧阈。  相似文献   

PEO-PPO-PEO嵌段共聚物的聚集行为及其在胶团萃取中的应用     

苏延磊  刘会洲 《中国科学院大学学报》2005,22(6):767-772

从分子水平研究了PEO-PPO-PEO嵌段共聚物聚集过程中分子基团微环境和构象的变化.FTIR光谱给出了温度、溶剂、嵌段共聚物组成等影响PEO-PPO-PEO嵌段共聚物胶团结构的定量信息。用无机盐和脂肪醇调控PEO-PPO-PEO嵌段共聚物聚集,荧光光谱技术提供了降低PPO链段与水的相互作用,推动嵌段共聚物在水中胶团化的证据。用水凝胶包埋PEO-PPO-PEO嵌段共聚物,实现了萃取水中低浓度多环芳烃的工艺循环。  相似文献   

Study of the stability of a series of synthetic colorants applied with styrene-acrylic copolymer, widely used in contemporary paintings, concerning the effects of accelerated ageing     

Zoe Eirini Papliaka  Konstantinos S. Andrikopoulos  Evangelia A. Varella 《Journal of Cultural Heritage》2010,11(4):381-391

This study examines the materials of a contemporary pictorial artwork, belonging to the Macedonian Museum of Contemporary Art in Thessaloniki (Greece), and needing conservation. The combined use of micro-FTIR and micro-Raman spectroscopy allowed the identification of almost all painting materials. Moreover, the stability of a series of synthetic pigments towards accelerated ageing is investigated in applications using the contemporary binding medium styrene-acrylic copolymer. The pigments in question are: Hansa yellow PY3 and PY74, quinacridone PV19 and PR122, naphthol AS PR112, phthalocyanine green PG7 and blue PB15, dioxazine PV37, van Dyck brown PBk11, ivory black PBk9, and titanium dioxide PW6. The organic pigments were applied alone or mixed with titanium dioxide, in rutile form or as a mixture of rutile/anatase. The experimental swatches were subjected to ageing tests, and subsequently studied as to colour changes by means of colorimetric measurements, and as to the molecular structure differentiations by infrared spectroscopy in reflectance mode. The ageing tests included exposure to high temperature and humidity (90 °C, 60% RH) and to ultraviolet radiation (350 nm, 30 °C and 50% RH, with a substantial temperature increase at 90 °C for 3 days). The greater colour difference is caused by high temperature and humidity, whereas paint layers containing TiO₂, and especially the mixture of the forms rutile/anatase, prove very susceptible to ultraviolet radiation, demonstrating a significant colour difference and extended molecular changes.  相似文献   

When Glass and Metal Corrode Together,VI: Chalconatronite     

Andrea Fischer  Gerhard Eggert  Jörg Stelzner 《文物保护研究》2020,65(3):152-159

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.  相似文献   

Near-infrared spectroscopy-derived total haemoglobin as an indicator of changes in muscle blood flow during exercise-induced hyperaemia     

Thiago Silveira Alvares  Gustavo Vieira de Oliveira  Rogério Soares  Juan Manuel Murias 《Journal of sports sciences》2020,38(7):751-758

ABSTRACT

Blood flow changes in response to exercise have been attributed, among other factors, to the effect of vasodilators factors on the microvasculature, suggesting a close relationship between small blood vessels and conducting arteries. The main purpose of this study was to determine the relationship between the changes in near infrared spectroscopy (NIRS)-derived total haemoglobin ([tHb]) and muscle oxygen saturation (SmO₂) signals and femoral artery blood flow in response to resistance exercise at fast- and slow-velocity muscle contraction. The study randomised crossover design included twelve participants. NIRS and blood flow measurements were continuously monitored before, during, and 5 min after the exercise protocol. There was a significant correlation between [tHb] reperfusion slope ([tHb]_slope) and peak blood flow (BF_peak) after slow- and fast-velocity muscle contraction (r = 0.83, p = 0.0008 and r = 0.72, p = 0.0080, respectively). No significant correlation existed between the SmO₂ reperfusion slope (SmO_{2_slope}) and BF_peak after both slow- and fast-velocity muscle contraction exercise (r = ?0.46, p = 0.1253 and r = 0.33, p = 0.2841, respectively). This study demonstrated a strong relationship between the NIRS-derived [tHb] and Doppler ultrasound BF during the recovery period of dynamic resistance exercise at both slow- and fast-velocity contraction.  相似文献