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1.
建立黑顺片中6种酯型生物碱含量的高效液相测定方法。采用岛津C18色谱柱(250 mm×4.6 mm,5μm),以乙腈–四氢呋喃(体积比为25∶15)为流动相A,以0.1 mol/L乙酸铵溶液(每1 000 m L加冰乙酸0.5 m L)为流动相B梯度洗脱,流量为1.0 ml/min,检测波长为235 nm,柱温为35℃。苯甲酰新乌头原碱、苯甲酰乌头原碱、苯甲酰次乌头原碱、新乌头碱、次乌头碱、乌头碱进样量分别在0.222~4.430,0.060~1.119,0.144~2.878,0.015~0.297,0.025~0.496,0.011~0.229μg范围内与色谱峰面积线性呈良好的线性关系,相关系数r均大于0.999 5,检出限分别为2.10,2.70,2.20,2.60,1.60,3.10 ng,样品在12 h内稳定。苯甲酰新乌头原碱、苯甲酰乌头原碱、苯甲酰次乌头原碱、新乌头碱、次乌头碱、乌头碱的加标回收率分别为98.7%~102.2%,98.6%~102.3%,99.0%~101.9%,102.0%~97.3%,102.1%~98.3%,95.7%~103.5%,测定结果的相对标准偏差分别为2.5%,2.5%,2.2%,2.3%,2.2%,1.7%(n=6)。该方法简便,测定结果准确、可靠,可为黑顺片的质量评价和质量控制提供参考。 相似文献
2.
为了实现对3~5μm中红外光的完美吸收,仿真设计了一种基于W/VO2周期性纳米盘阵列的可调中红外宽频吸收器,利用时域有限差分法模拟计算了结构参数对吸收器性能的影响.在最佳结构参数条件下,吸收器表现出偏振无关和广角吸收的特性,在3.1~3.6μm范围内吸收率达99%以上,峰值吸收率为99.99%.低温时入射光的磁场被束缚在各单元VO2介质层的中心并得到完美吸收;高温时VO2发生相变表现为金属相,抑制吸收,高低温的吸收率差值可达78.8%.该吸收器有效弥补了传统吸收器吸收频带窄、吸收率不可调的缺陷,对中红外光电器件的应用有参考价值. 相似文献
3.
Chenglong Yu a b Xin Hao a Hongtao Jiang a Lili Wang a a School of Materials Science Engineering Shaanxi University of Science & Technology Xi’an China b Research Laboratory of Hydrothermal Chemistry Faculty of Science Kochi University Kochi Japan 《中国颗粒学报》2011,9(1)
Fe 3 O 4 nano-whiskers were synthesized via ultrasonic-aided reduction of FeCl 2 ·4H 2 O with N 2 H 4 ·H 2 O in concentrated NaOH solution. Phase identification and morphology observation were conducted by X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM). Face scanning energy dispersive spectrum (face scanning EDS) and two-dimensional fast Fourier transform (2DFFT) for element distribution were carried out for confirming compos... 相似文献
4.
5.
Xuexi Tie a Junji Cao b a National Center for Atmospheric Research Boulder CO USA b SKLLQG Institute of Earth Environment Chinese Academy of Sciences No. Fenghui South Road High-Tech Zone Xi’an China 《中国颗粒学报》2010,8(1)
PARTICUOLOGY regrets that the above paper was mistakenly classified as a ‘Review’ rather than an ‘Invited paper’ when originally published in volume 7, issue 6, 426–431. 相似文献
6.
W18Cr4V 总被引:2,自引:1,他引:1
The frictionand
wear characteristics of the surfa ce compound layer of W18Cr4V steel by combined treatment
of ion nitrocarburizing-ion sulphurizing were investigated. The friction coefficient of
the compound l ayer against GCr15 steel was determined witha block-ring friction tester.
The wear test was carried out with a reciprocating wear tester. The worn surface was
analyzedby scanning electron microscopy(SEM). The experimental results reveale d that the
friction coefficient was lower for treatedW18Cr4V steel against GCr1 5 steel. The wear
resistance of the compound layer was higher because the nitroc arbonide andthe sulphide in
the compound layer were capable of friction-reduct ion and adhesion-inhibition. 相似文献
7.
Low Density Self-Assembled InAs/GaAs Quantum Dots Grown by Metal Organic Chemical Vapour Deposition 下载免费PDF全文
The self-assembled InAs quantum dots (QDs) on GaAs substrates with low density (5×10^8 cm^-2) are achieved using relatively higher growth temperature and low InAs coverage by low-pressure metal-organic chemical vapour deposition. The macro-PL spectra exhibit three emission peaks at 1361, 1280 and 1204nm, corresponding to the ground level (GS), the first excited state (ES1) and the second excited state (ES2) of the QDs, respectively, which are obtained when the GaAs capping layer is grown using triethylgallium and tertiallybutylarsine. As a result of micro-PL, only a few peaks from individual dots have been observed. The exciton-biexciton behaviour was clearly observed at low temperature. 相似文献
8.
构建了一种基于羧基化单壁碳纳米角(oxSWCNHs)的简单、灵敏的荧光传感体系用于胰蛋白酶的检测。实验中合成了水溶性的oxSWCNHs,并设计了一段羧基荧光素(FAM)标记肽段作为胰蛋白酶的底物,该底物能与胰蛋白酶进行特异性反应。当体系中没有胰蛋白酶存在时,FAM标记的肽段可以被oxSWCNHs强烈吸附,致使体系具有较低的荧光背景;当体系中有胰蛋白酶存在时,胰蛋白酶可以与其底物肽段发生特异性水解反应,导致FAM标记的肽段水解为单个氨基酸,致使FAM远离oxSWCNHs表面,FAM荧光不能被oxSWCNHs淬灭,体系具有较强的荧光强度,从而实现荧光传感体系对胰蛋白酶的检测。该传感体系线性范围为0~2.5μg/mL,可用于尿液中胰蛋白酶的测定。 相似文献
9.
YANG Jian-Guoa PAN Fu-Youb② SHAO Hongb a 《结构化学》2005,24(11):1286-1289
1 INTRODUCTION Azole derivatives, such as the derivatives of pyra- zole, imidazole, triazole including benzotriazole, te- trazole and indole, have extensive biological activi- ties. They have become the central focus of studies of agricultural chemicals, medicines, plant growth regulating agents and so on[1, 2]. Schiff bases also constitute a good type of biologically active sub- structures. Studies on pyrazole Schiff base-type fun- gicides have been reported[3, 4]. However, some struc- … 相似文献
10.
KAN Zi-Guia b CHENG Wen-Dana? WU Dong-Shenga ZHANG Haoa GONG Ya-Jinga ZHU Jinga TONG Hua-Nana a 《结构化学》2005,24(12):1468-1475
1 INTRODUCTION stand the chemical bonding properties and electronic origins of optical transition for solid In(PO3)3, the During the past decades, many indium phosphates crystal energy band and optical response functions have been reported and researched on their conduc- are also calculated. tivity anisotropy, band structure and optical proper- ties[1, . However, to our current knowledge, the com- 2] 2 EXPERIMENTALAND pounds containing alkaline-earth metals are rarely COMPUTATIO… 相似文献