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建立了利用苯并[b]吖啶酮-5-乙基对甲苯磺酸酯(BAETS)作为柱前荧光标记的高灵敏和高选择性的脂肪酸分析方法,并考察了该方法的分析性能。优化了34种混合脂肪酸的衍生条件,采用Hypersil BDS C8色谱柱(200×4.6mm i.d.,5μm)分离,荧光检测激发和发射波长为λex/λem=273/503nm,对脂肪酸衍生物进行定性定量分析。多数脂肪酸的线性回归系数大于0.9996,检测限在11.71~68.26fmol之间。质谱在大气压化学电离源正离子模式下,实现了玫瑰花粉中脂肪酸组分的分离分析及鉴定。方法检测限低,重现性好,对新疆和田玫瑰花粉样品的测定结果真实可靠。 相似文献
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Raman Investigation of Sodium Titanate Nanotubes under Hydrostatic Pressures up to 26.9GPa 下载免费PDF全文
High pressure behavior of sodium titanate nanotubes (Na2Ti2O5) is investigated by Raman spectroscopy in a diamond anvil cell (DAC) at room temperature. The two pressure-induced irreversible phase transitions are observed under the given pressure. One occurs at about 4.2 GPa accompanied with a new Raman peak emerging at 834 cm-1 which results from the lattice distortion of the Ti-O network in titanate nanotubes. It can be can be assigned to Ti-O lattice vibrations within lepidocrocite-type (H0.7Ti1.825V0.175O4・H2O)TiO6 octahedral host layers with V being vacancy. The structure of the nanotubes transforms to orthorhombic lepidocrocite structure. Another amorphous phase transition occurs at 16.7 GPa. This phase transition is induced by the collapse of titanate nanotubes. All the Raman bands shift toward higher wavenumbers with a pressure dependence ranging from 1.58-5.6 cm-1/GPa. 相似文献
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High-temperature and high-pressure behaviours of β-Ga2O3 powder are studied by energy-dispersive x-ray diffrac- tion in a diamond anvil cell (DAC). It is found that the phase transition from the monoclinic β-Ga2O3 to the trigonal α-Ga2O3 occurs at around 19.2 GPa under cold compression. By heating the powder to 2000 K at 30 GPa, we confirm that α-Ga2O3 is the most stable structure at the high pressure. Furthermore, the structural transition from β-Ga2O3 to α-Ga2O3 is irreversible. After laser heating, the recrystallized Ga2O3 has a preferable (012) orientation. This interesting behaviour is also discussed. 相似文献
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对于天然镁铝石榴子石(Pyrope),在0~25.3 GPa压力条件下,在美国布鲁克海汶(Brookhaven)国家实验室国家同步辐射实验站,利用金刚石压腔装置(DAC),进行了角散X 射线粉末衍射的高压原位测量,获得了天然镁铝石榴子石随压力变化的衍射图谱。采用Materials Studio软件的Refinement模块对衍射图谱进行了分析,得到了镁铝石榴子石的晶胞参数及其随压力的变化,进而利用Birch-Murnaghan状态方程进行数值拟合,得到了镁铝石榴子石的零压体弹模量B0=199 GPa(B′0=4)。 相似文献