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41.
蓝色圆珠笔字迹色痕FTIR光谱解析 总被引:2,自引:2,他引:2
本文系统解析了108种油墨色痕的傅立叶变换显微红外谱图。根据红外谱图的特征峰,识别了油墨中的溶剂、色科、树脂等组分,这为字迹色痕形成时间的无损分析奠定了基础。 相似文献
42.
Yao Benlin Xiao Yiqun Jia Yanhong Meng Zhaokai Chen Hui Ye Guoan He Hui 《Journal of Solid State Electrochemistry》2021,25(2):513-526
Journal of Solid State Electrochemistry - In the last twenty years, direct electro-reduction of solid oxides in molten salt has been investigated extensively. Compared with thermodynamics, kinetics... 相似文献
43.
Guoan Zhu Changtai Tian Jimin Zheng 《Journal of Thermal Analysis and Calorimetry》1995,45(1-2):269-273
The specific heat capacity of M·NBA·DEA crystals were measured by differential scanning calorimetry. Both the direct and ratio methods of DSC were used in the determinations. The relative average deviations are 0.08% to 0.18%. The relative average deviations of ratio method are 0.23–0.69%. 相似文献
44.
细胞信号传导是近年来生命科学研究的热点之一。有关蛋白转录后修饰 (如蛋白质磷酸化、乙酰化、糖基化等 ) ,信号肽序列测定 ,信号传导途径和多通道调节方式 ,蛋白自折叠及构象变化 ,小分子脂类信号分子等研究由于质谱技术的快速发展而取得了突破性的进展 相似文献
45.
Microemulsion electrokinetic chromatography (MEEKC) and solvent modified micellar electrokinetic chromatography (MEKC) were investigated with the goal of the rapid separation of complex heroin and amphetamine samples. The rapid simultaneous separation of 17 species of heroin, amphetamine and their basic impurities and adulterants was performed within about 10 min using MEEKC for the first time, whereas solvent modified MEKCs were unable to resolve all the components. The comparisons between MEEKC and solvent modified MEKC proved internal lipophilic organic phase in microemulsions played an important role in improving the separation performance with respect to efficiency. However, the role of internal lipophilic organic phase in MEEKC was disgusted at high concentrations of cosurfactant, and the separations of MEEKC and 1-butanol modified MEKC became similar at high concentrations of 1-butanol. The evaluation of reproducibility, linearity and detection limit of optimized MEEKC method provided good results for all the analytes investigated, thus allowing its application to real controlled drug preparation analysis. 相似文献
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毛细管电泳及其质谱联用技术分析重组人促红细胞生成素 总被引:3,自引:0,他引:3
用高效毛细管电泳测定了重组人促红细胞生成素(rhEPO)的微多相性、肽图,同时采用毛细管电泳质谱联用技术鉴定了部分非糖基化胰酶消解片段和O-126糖基化肽的结构。方法简便、快速,适用于rhEPO半成品的质量控制。 相似文献
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The natural abundances of stable nitrogen isotopes in plants and soils have been viewed as recorders that can be used to reconstruct paleoclimate and ecological processes or to indicate the biogeochemical cycle of nitrogen in nature. This study systematically measured the nitrogen isotope composition (δ15N) in plants and surface soils along an altitudinal transect of elevation range of 1200 to 4500 m on the eastern slope of Mount Gongga in southwest China. The influences of photosynthetic pathways on plant δ15N as well as the effects of temperature and precipitation on δ15N altitudinal trends in plants and surface soils are discussed. Across this altitude transect, the δ15N values of C3 and C4 plants on Mount Gongga range between ?9.87‰ and 7.58‰ with a mean value of ?1.33‰, and between ?3.98‰ and 4.38‰ with a mean value of ?0.25‰, respectively. There is an evident δ15N difference between C3 plants and C4 plants. If, however, you only compare C4 plants with those C3 plants growing at the same altitudinal range, no significant difference in δ15N exists between them, suggesting that photosynthetic pathway does not have an influence on the plant δ15N values. In addition, we found that C3, C4 plants and surface soil (0–5 cm depth) all trend significantly towards more negative δ15N with increasing elevation. Furthermore, this study shows that the mean annual temperature and the mean annual precipitation positively and negatively correlate with δ15N in C3 and C4 plants, respectively. This indicates that precipitation and temperature are the main controlling factors of the δ15N variation in plants with altitude. We propose that lower δ15N values of plants and soils at higher altitude should be attributed to lower mineralization and lower net nitrification rates induced by low temperature and abundant rainfall. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献