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151.
高效液相色谱法检测肉类食品中4种嘌呤碱 总被引:4,自引:1,他引:3
建立了肉类食品中嘌呤含量的多组分高效液相色谱分析方法。采用V(三氟乙酸)∶V(甲酸)∶V(水)=5∶5∶1溶液在90℃下水解样品12min,水解液浓缩后过膜,以0.02mol/LKH2PO4(pH=3.8)为流动相进行色谱分离;流速1.0mL/min;柱温30℃;DAD二极管矩阵检测器检测,检测波长254nm;进样量10μL。在0.4~40mg/L的浓度范围内,各嘌呤的响应峰面积与其相应浓度呈良好相关性,r>0.9999,通过水解条件实验证实,90℃下12min能够使样品中嘌呤完全水解为游离态,且不破坏嘌呤物质,相对标准偏差<16.0%。本方法分离度好,能够快速检测肉类食品中4种主要的嘌呤组分。 相似文献
152.
153.
采用3种不同的方式制备ZnO薄膜籽晶层:旋涂、喷雾热解和脉冲激光沉积。对于每一种制备方式,其薄膜的晶体结构、形貌、表面粗糙度等性能分别用X射线衍射(XRD)、扫描电子显微镜(SEM)和原子力显微镜(AFM)进行了表征。之后,通过水热合成方法,在3种籽晶层衬底上制备得到具有不同结构和形貌特征的ZnO纳米棒阵列。结果表明,ZnO纳米棒生长和籽晶层制备方式具有极强的相关性。最后,对两者相关性的生长机理进行了解释。 相似文献
154.
Yan Wan Jia-Qi Ma Chao Hong Mei-Chao Li Li-Qun Jin Xin-Quan Hu Bao-Xiang Hu Wei-Min Mo Nan Sun Zhen-Lu Shen 《中国化学快报》2018,29(8):1269-1272
A simple and efficient method for preparation of imines by the oxidative coupling of alcohols and amines using ABNO/KOH as the catalysts, and air as the economic and green oxidant was developed. 相似文献
155.
用四硫富瓦烯作为酶与电极之间的电子传递体,通过Nafion水溶液把葡萄糖氧化酶固定在Nafion-TTF修饰玻碳电极上,最后在电极上装饰一层Nafion膜,制备成葡萄糖传感器。Nafion膜不仅能防止四硫富瓦烯流失,而且能把抗坏血酸、尿酸等电活性物质阻挡在电极外,防止其干扰,同时具有防污性能。通过实验表明TTF^+1、TTT^+2都能够氧化葡萄糖氧化酶中的辅酶。该传感器的线性范围为3.0×10^- 相似文献
156.
Zhao Chen-Zi Duan Hui Huang Jia-Qi Zhang Juan Zhang Qiang Guo Yu-Guo Wan Li-Jun 《中国科学:化学(英文版)》2019,62(10):1286-1299
Li-metal anodes are one of the most promising energy storage systems that can considerably exceed the current technology to meet the ever-increasing demand of power applications. The apparent cycling performances and dendrite challenges of Li-metal anodes are highly influenced by the interface layer on the Li-metal anode because the intrinsic high reactivity of metallic Li results in an inevitable solid-state interface layer between the Li-metal and electrolytes. In this review, we summarize the recent progress on the interfacial chemistry regarding the interactions between electrolytes and ion migration through dynamic interfaces. The critical factors that affect the interface formation for constructing a stable interface with a low resistance are reviewed. Moreover, we review emerging strategies for rationally designing multiple-structured solid-state electrolytes and their interfaces, including the interfacial properties within hybrid electrolytes and the solid electrolyte/electrode interface. Finally, we present scientific issues and perspectives associated with Li-metal anode interfaces toward a practical Li-metal battery. 相似文献
157.
Yi-Hao Chen Shih-Ji Chen Jia-Qi Li Zhenqiang Wu Gene-Hsiang Lee Yi-Hung Liu Wei-Ting Cheng Chen-Yu Yeh Chi-How Peng 《Journal of polymer science. Part A, Polymer chemistry》2020,58(1):101-113
A series of cobalt(II) phenoxy-imine complexes (CoII(FI)2) have been synthesized to mediate the radical polymerization of vinyl acetate (VAc) and methyl acrylate (MA) to evaluate the influence of chelating atoms and configuration to the control of polymerization. The VAc polymerizations showed the properties of controlled/living radical polymerization (C/LRP) with complexes 1a and 3a , but the catalytic chain transfer (CCT) behaviors with complexes 2a , 1b , 2b , and 3b . The control of VAc polymerization mediated by complex 1a could be improved by decreasing the reaction temperature to approach the molecular weights that not only linearly increased with conversions but also matched the theoretical values and relatively narrow molecular weight distributions. The catalytic chain transfer polymerizations (CCTP) mediated by complexes 2a , 1b , 2b , and 3b were characterized by Mayo plots and the polymer chain end double bonds were observed by 1H NMR spectra. The tendency toward C/LRP or CCTP in VAc polymerization mediated by CoII(FI)2 could be determined by the ligand structure. Cobalt complex coordinated by the ligand with more steric hindered and less electron-donating substituents favored the controlled/living radical polymerization. In contrast, the efficiency of CCT process could be enhanced by less steric hindered, more electron-donating ligands. The controlled/living radical polymerization of MA, however, could not be achieved by the mediation of these cobalt(II) phenoxy-imine complexes. Associated with the results of polymerization mediated by other cobalt complexes, this study implied that the configuration and spin state of cobalt complexes were more critical than the chelating atoms to the control behavior of radical polymerization. © 2019 Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58, 101–113 相似文献
158.
Jia-Qi Li Alexander Paptchikhine Thavendran Govender Pher G. Andersson 《Tetrahedron: Asymmetry》2010,21(11-12):1328-1333
New bicyclic thiazole-based chiral N,P-chelating ligands were developed. High activities and enantioselectivities were achieved in the iridium-catalyzed asymmetric hydrogenation of olefins with the new ligands. 相似文献
159.
Wei-De Zhang Jin Chen Liao-Chuan Jiang Yu-Xiang Yu Jia-Qi Zhang 《Mikrochimica acta》2010,168(3-4):259-265
A highly sensitive and selective glucose biosensor has been constructed by using highly dispersed NiO nanoparticles supported on well-aligned MWCNTs (NiO/MWCNTs) as sensing interface. The NiO/MWCNTs nanocomposite was synthesized by magnetron sputtering deposition of NiO nanoparticles on vertically aligned carbon nanotubes. The nanocomposite electrode showed high electrochemical activity towards the oxidation of glucose in 0.20 M NaOH solution. At an applied potential of +0.50 V, it gives a fast response time (< 5 s) and a linear dependence (R?=?0.997) on the glucose concentration up to 7.0 mM with an extraordinarily high sensitivity of 1.77 mA mM-1 cm-2 and a detection limit of 2 μM. The interference by the oxidation of common interfering species such as ascorbic acid, dopamine, uric acid, lactose, and fructose is effectively avoided. The electrode was used to analyze glucose concentration in human serum samples. It allows highly sensitive, stable, and fast amperometric sensing of glucose, which is promising for the development of nonenzymatic glucose sensors. 相似文献
160.
Wei-De Zhang Bin Xu Yu-Xiang Hong Yu-Xiang Yu Jian-Shan Ye Jia-Qi Zhang 《Journal of Solid State Electrochemistry》2010,14(9):1713-1718
In this paper, an electrochemical sensor for sensitive and convenient determination of salicylic acid (SA) was constructed
using well-aligned multiwalled carbon nanotubes as electrode material. Compared to the glassy carbon electrode, the electro-oxidation
of SA significantly enhanced at the multiwalled carbon nanotube (MWCNT) electrode. The MWCNT electrode shows a sensitivity
of 59.25 μA mM−1, a low detection limit of 0.8 × 10−6 M and a good response linear range with SA concentration from 2.0 × 10−6 to 3.0 × 10−3 M. In addition, acetylsalicylic acid was determined indirectly after hydrolysis to SA and acetic acid, which simplified the
detection process. The mechanism of electrochemical oxidation of SA at the MWCNT electrode is also discussed. 相似文献