海南火山金钗石斛不同部位的红外光谱法结构解析

运用红外光谱法对海南火山金钗石斛的商业干粉、新鲜植株的叶片、茎干、根须四种样品进行红外光谱分析,并对红外光谱图进行解析。傅里叶变换红外光谱图表明,四种样品的一维红外光谱图非常相似,具有多个相似的特征峰和官能团,但峰强有所不同。二阶导数处理红外光谱图能进一步提高光谱分辨率、增加光谱灵敏度。对一维红外光谱进行二阶求导后,二阶导数红外光谱图进一步验证了以上结果,石斛样品中均含有脂类、芳香类和淀粉类成分,但石斛部位不同,其含量有所差异。红外光谱解析能够验证海南火山口地区金钗石斛样品不同部位所含物质结构的差异,对于探究高效快速的石斛鉴定方法具有重要意义,其结果表明火山口地区种植的金钗石斛各部位均含有大量的活性成分,具有良好的药用价值。     

不同产地桔梗的红外光谱整体成分鉴别研究

采用傅里叶变换红外光谱法和显微红外光谱技术对不同产地桔梗进行鉴别.结果表明,不同产地桔梗的一阶红外光谱图整体上差别并不明显,二阶导数处理后,各产地的特征峰差异得以显现,显微红外光谱图则进一步直观清晰地显现出桔梗皂苷d的含量多少与分布区域,进一步佐证了不同产地桔梗间桔梗皂苷d的含量差异的结果.根据不同产地地理远近来分析,...     

地骨皮及其混伪品的红外指纹图谱鉴别

采用红外光谱法结合二阶导数光谱法对地骨皮及混伪品的红外光谱特征进行分析与鉴定。地骨皮正品的一维和二阶导数指纹图谱分别有14个和34个共有峰。混伪品与正品间的共有峰减少,并产生新的吸收峰。本文明确了地骨皮正品的一维和二阶导数红外共有峰模式,找到了地骨皮正品与混伪品的红外指纹图谱区别特征。本法具有准确、简便、直观等优点,适合地骨皮及混伪品的鉴别与区分。     

聚乙烯C–H伸缩振动二维红外光谱研究

在293~393 K范围内,分别测定聚乙烯(PE)的一维红外光谱、二阶导数红外光谱和去卷积红外光谱来确定PE分子结构。进一步采用二维红外光谱研究了聚乙烯亚甲基C–H伸缩振动模式(νCH2)的模式。研究发现,PE分子中存在晶区和非晶区。随着测定温度的升高,PE分子中νCH2红外吸收强度变化快慢顺序为:2 920 cm-1(νas(CH2)crystalline)2 930 cm-1(νas(CH2)amorphous)2 850 cm-1(νs(CH2)crystalline)2 858 cm-1(νs(CH2)amorphous)。此项研究显示出二维红外光谱在高分子材料热变性分析中的重大作用。     

聚氯乙烯亚甲基弯曲振动ATR二维红外光谱研究

在303~393 K的温度范围内,利用变温傅里叶变换衰减全反射红外光谱(ATR-FTIR),分别研究了聚氯乙烯亚甲基弯曲振动模式δ_(CH_2)的一维红外光谱、二阶导数红外光谱、四阶导数红外光谱、去卷积红外光谱和二维红外光谱。结果表明:当温度低于玻璃化转变温度时,聚氯乙烯分别在1420、1425、1430、1435和1447 cm~(-1)处出现红外吸收峰,随着温度的升高,聚氯乙烯δCH_2红外吸收强度的变化快慢顺序为1447 cm~(-1)1420 cm~(-1)1430cm~(-1)1425 cm~(-1)1435 cm~(-1);当温度超过玻璃化转变温度后,聚氯乙烯在1420、1425、1430和1435 cm~(-1)处出现红外吸收峰,而随着温度的升高,聚氯乙烯δCH_2红外吸收强度的变化快慢顺序为1425 cm~(-1)1420 cm~(-1)1430 cm~(-1)1435 cm~(-1)。此项研究拓展了ATR-FTIR技术在聚氯乙烯热变性方面的应用范围。     

异丙硫醇产品的红外和核磁共振等的分析

利用元素分析仪、红外光谱仪、核磁共振波谱和气相色谱仪,对以2-溴丙烷和硫脲为原料,通过硫脲法制备的异丙硫醇产品进行了结构表征,结果表明该产品为目的产物,且纯度较高,质量分数可达到99.49％.     

纤维的红外光谱定性分析

本文概述了红外光谱在纤维定性分析中的应用,并对各常用纤维的红外特征谱带及其制样方法均作详尽解析。     

红外光谱法鉴定爆炸物

依据爆炸物的种类,介绍了烟火药剂、硝酸钾类爆炸物、硝酸铵类炸药的分离方法。根据化学分离方法进行分离定量,利用红外光谱技术对各爆炸物分离组分进行定性,鉴定爆炸物的种类。     

氟橡胶的红外光谱研究

采用红外(IR)光谱,包括一维红外光谱、二阶导数红外光谱、四阶导数红外光谱和去卷积红外光谱对氟橡胶(FKM)的分子结构进行了研究。试验发现:氟橡胶的红外吸收模式主要包括CH2不对称伸缩振动模式(νasCH2-FKM)、CH2对称伸缩振动模式(νsCH2-FKM)、CH2弯曲伸缩振动模式(δCH2-FKM)、CF2不对称伸缩振动模式(νasCF2-FKM)、CF2对称伸缩振动模式(νsCF2-FKM)和CFCl伸缩振动模式(νCFCl-FKM)等。研究发现:氟橡胶的去卷积IR光谱的谱图分辨能力要优于相应的一维IR光谱、二阶导数IR光谱和四阶导数IR光谱。此研究拓展了IR光谱在氟橡胶结构及应用研究的范围。     

傅里叶变换红外光声光谱在火炸药研究领域中的应用

阐述了傅里叶变换红外光声光谱（FTIR－PAS）的基本原理，测试条件及其在火炸药研究领域中的应用，证实了该技术在含能材料分析和研究中的实用价值。     

巯基聚醚聚氨酯橡胶的制备及温敏性谱学研究

以过量甲苯二异氰酸酯和聚乙二醇为主要原料制备预聚物;以三乙烯二胺为催化剂,聚乙二醇二丙烯酸酯为交联剂,预聚物和巯基乙醇反应制备巯基聚醚聚氨酯橡胶。考察了催化剂用量和交联剂用量对产物性能的影响,采用变温红外光谱和拉曼光谱对其温敏性进行了研究。结果表明:催化剂用量0. 8%,交联剂用量1. 0%,产物性能最佳;200℃以下样品的红外吸收峰受温度变化影响不大;200℃时,样品在2 273 cm-1处出现-N==C==O特征吸收峰,同时2 583 cm-1处的―SH特征伸缩振动吸收峰消失。     

Isomer Identification of Monohydroxylated Polycyclic Aromatic Hydrocarbon Metabolites by Gas Chromatography/Fourier Transform Infrared Spectroscopy and Carbon-13 Nuclear Magnetic Resonance Spectroscopy

The foundation for a systematic approach utilizing spectral/structural correlations was established for unambiguous identification of monohydroxylated polyaromatic hydrocarbon metabolite (PAHm) isomers. Using elements of a theoretical/empirical valence-bond model developed earlier in our laboratory for isomer identification of chlorinated dibenzo- p -dioxin isomers, both gas chromatography/Fourier transform infrared spectroscopy (GC/FTIR) and carbon-13 nuclear magnetic resonance ( 13 C NMR) spectroscopy were employed for PAHm isomer identification. Results indicate that PAHm isomers also can be systematically identified by these techniques. However, many of the parameters leading to the success of the dioxin analysis (high symmetry of the parent dioxin molecule and laterally stabilized delocalization from chlorine substituents through ether linkage oxonium ions) are not generally present in the PAHm ring systems under investigation. The observed infrared parameters in PAH metabolites are C--O stretch, O--H stretching and bending vibrations, along with C=C skeletal stretching vibrations. In addition, 13 C NMR parameters such as chemical shift perturbations for carbons adjacent to functional groups have been observed.     

超细硼酸锌对LDPE/IFR体系热稳定性的影响

采用热重-差热联机分析和傅里叶变换红外光谱研究了超细硼酸锌(UZB)对膨胀型阻燃剂阻燃低密度聚乙烯的热降解过程的影响。结果表明:UZB对膨胀阻燃低密度聚乙烯体系具有明显的热稳定作用,可使体系起始热失重温度提高,并且显著增加残炭量。差热分析结果表明,UZB可进一步降低膨胀阻燃低密度聚乙烯体系热分解的放热量,降低热降解速度;红外光谱分析表明,UZB与膨胀型阻燃剂阻燃低密度聚乙烯复合体系热解残余物具有芳烃结构的类石墨炭层及含P-O-P、P-O-C、B-B的复杂炭层结构,对内部基材具有良好的高温保护作用。     

红外光谱法分析复方丹参片品质的研究

研究了复方丹参片质量品质的傅立叶红外光谱法（FTIR）分析.结果表明：1610 cm-1附近的特征吸收峰可作为分析复方丹参片中有效成分相对含量的依据,相对峰强度越大,有效成分含量越高.986 cm-1和1016 cm-1附近的特征吸收峰可作为分析复方丹参片中辅料添加类型和相对含量的依据,相对峰强度越大,辅料添加量越多.傅立叶红外光谱法可用于复方丹参片品质的快速分析.     

漫反射傅立叶变换红外光谱法在结构胶粘剂匹配性研究中的应用

本文应用漫反射傅立叶变换红外光谱（Ｄｉｆｆｕｓｅ　Ｒｅｆｌｅｃｔａｎｃｅ　Ｉｎｆｒａｒｅｄ　Ｆｏｕｒｉｅｒ　Ｔｒａｎｓｆｏｒｍ）法对Ｊ－３０Ｇ高温固化结构胶粘剂与双马来酰亚胺（ＢＭＩ）胶粘剂的匹配性进行了定性的讨论．     

Role of Ozone Concentrations and Exposure Times in Extending Shelf Life of Strawberry

Efficiency of three aqueous ozone concentrations (0.075 ppm, 0.15 ppm, 0.25 ppm) and two exposure times (2 and 5 min) were investigated for maintaining strawberry quality. Exposure to 0.075 ppm and 0.15 ppm ozone delayed the changes in pH, total soluble solids, firmness and electrical conductivity. All ozone treatments prevented mold growth during storage. However, the 0.25 ppm ozone treatment caused loss of strawberry quality due to high ozone concentration. The results have shown that; low (0.075 ppm) and middle (0.15 ppm) ozone concentrations can be applied to extend the shelf-life of strawberries by at least 3 weeks under refrigerated conditions.     

Evaluation of Low‐Cost Separators for Increased Power Generation in Single Chamber Microbial Fuel Cells with Membrane Electrode Assembly

We compared novel size‐selective separators, namely the textile fabrics of polyphenylene sulfide (PPS) and sulfonated polyphenylene sulfide (S‐PPS), and the nonwoven fabrics of polypropylene80 (PP 80) and PP 100, with commonly used ion exchange separators (Nafion 117 and cation exchange membane‐7000; CMI‐7000) in terms of power generation, oxygen diffusion, and biofilm formation in a single chamber microbial fuel cell. Size‐selective separators exhibited more power generation than ion selective separators. MFC operation with size‐selective separators generated power output ranging 0.407 to 0.591 V (1000 Ω), whereas with Nafion it was 0.272 V. In polarization analysis, S‐PPS resulted in the highest power density of 190 mW/m², whereas it was 24 mW/m² with Nafion‐117. Size selective separators showed similar or higher proton conductivity than Nafion 117. Oxygen mass transfer coefficients of size‐selective separators (K_O = 3.7 ∼ 7.5 × 10⁻⁵) were lower or similar to Nafion (K_O = 7.5 × 10⁻⁵). Fourier‐transform infrared spectroscopy and scanning electron microscopy analysis revealed that all separators (PP80, S‐PPS, and Nafion) contained proteins or carbon chain compounds after 300‐day operation, and however, Nafion 117 seems to be more susceptible to biofouling than the other separators.     

Rheological analysis of the gelation behavior of tetraethylorthosilane/ vinyltriethoxysilane hybrid solutions

The gelation behavior of tetraethylorthosilane (TEOS) sol in the presence of a silane coupling agent vinyltriethoxysilane (VTES) was investigated experimentally. Specifically, the gel time and gel structure were analyzed by the rheological multiwave test of Fourier transform mechanical spectroscopy (FTMS) for the mixtures of TEOS/ VTES with various molar ratios at different temperatures. Gelation was accomplished through the sol-gel reactions of the silicon alkoxide TEOS in aqueous acidic solution. The results showed that, at elevated temperatures, the gel point was scattered and obscured by the noise in low frequencies owing to the enhanced thermal agitations. In this case, the statistical method was used to find the exact gel time. The activation energy of gelation and the gel exponent ranged from 25 to 30 kJ/mol and from 0.581 to 0.771, respectively, depending on the TEOS/VTES composition. The fractal dimension was estimated from the gel exponent and indicated the gel structure and that the TEOS/VTES solutions formed a relatively open and coarse gel structure.     

Effect of alkalis on fresh C-S-H gels. FTIR analysis

The present study addresses the effect of different concentrations of Na₂O on the structure of a composition of fresh C-S-H gels. The gels were synthesized from laboratory reagents, using calcium nitrate as the source of calcium and a sodium silicate solution for the silicon. A 10-M solution of NaOH was used to maintain a pH of over 13 throughout. The synthesized gels were exposed to different amounts of 8-M NaOH to determine their chemical stability and subsequently characterized with Fourier transform IR spectroscopy. The results showed that the addition of different concentrations of sodium leads to C-S-H gel modification even in the very short term.