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991.
团状雪灵芝三种提取工艺的红外光谱跟踪分析 总被引:1,自引:0,他引:1
为了建立一种基于红外光谱跟踪分析的过程分析方法用于团状雪灵芝(AP)提取分离过程的宏观指导,从同一工艺不同提取物及不同工艺同一提取物两个方面,对三种提取工艺各四种提取物进行红外光谱跟踪测试,并对红外光谱及相应二阶导数谱进行了深入的对比分析研究。光谱分析结果显示,同一工艺的不同提取物具有明显不同的光谱吸收特征;不同工艺同一提取物的吸收特征总体相似,但彼此之间也存在明显的光谱差异。1 603和1 123cm-1的特征峰表明,提取法一中,黄酮类及其糖苷主要进入了酯提物,余者进入了醇提物。相反,方法二、三中,大部分黄酮类进入了醇提物,水提物中还存在微量黄酮苷。此外,根据2 850cm-1峰强可知,方法二酯提物中苷元及高级饱和烃基含量较高。类似的,1 066和2 927cm-1等特征吸收峰表明方法三的醇提物中糖苷及多糖含量较高。研究结果表明,AP组分在不同提取工艺中的迁移规律不尽相同,提取过程中的物质迁移信息可以通过各提取物红外光谱的跟踪分析进行记录和直观解析。红外光谱跟踪分析法是一种快速、有效、低碳、环保的过程分析方法,对于诸如AP等植物提取分离过程的质量控制或工艺优化具有宏观指导意义。 相似文献
992.
Abstract Dielectric barrier discharge is a nonequilibrium plasma, and its industrial application has been on a large scale. Similarly, its prominent features of high dissociation ability at low working temperature and low power consumption, simple and adjustable configuration, ambient working conditions, and long lifetime are favorable for developing a wide array of analytical devices as well. This review addresses the basics of dielectric barrier discharge and emphasizes their analytical applications in analytical atomic spectrometry, chemiluminescence, gas chromatographic detectors, ion source for mass spectrometry, and ion mobility spectrometry with 103 references. 相似文献
993.
根据现代搜索理论的发展,对船载直升机在目标搜索中的具体运用进行了研究,建立了船载直升机目标搜索时搜索力的最优配置模型,解决了在已知目标分布的条件下船载直升机搜索中选择初始探测点、确定搜索路径、确定搜索次数以及搜索效率评估等问题. 相似文献
994.
995.
Modeling the qubit by a two-level semiclassical detector coupled to a massless scalar field, we investigate how the Unruh effect affects the nonlocality and entanglement of two-qubit and three-qubit states when one of the entangled qubits is accelerated. Two distinct differences with the results of free field model in non-inertial frames are (i) for the two-qubit state, the CHSH inequality cannot be violated for sufficiently large but finite acceleration, furthermore, the concurrence will experience “sudden death”; and (ii) for the three-qubit state, not only does the entanglement vanish in the infinite acceleration limit, but also the Svetlichny inequality cannot be violated in the case of large acceleration. 相似文献
996.
Chao Zhang Yongzhong Jia Yan Jing Ying Yao Jun Ma Jinhe Sun 《Physica B: Condensed Matter》2012,407(24):4649-4654
The electronic structures and optical properties of N-doped, S-doped and N/S co-doped SrTiO3 have been investigated on the basis of density functional theory (DFT) calculations. Through band structure calculation, the top of the valence band is made up of the O 2p states for the pure SrTiO3. When N and S atoms were introduced into SrTiO3 lattice at O site, the electronic structure analysis shows that the doping of N and S atoms could substantially lower the band gap of SrTiO3 by the presence of an impurity state of N 2p on the upper edge of the valence band and S 2p states hybrid with O 2p states, respectively. When the N/S co-doped, the energy gap has further narrowing compared with only N or S doped SrTiO3. The calculations of optical properties also indicate a high photo response for visible light for N/S co-doped SrTiO3. Besides, we find a new impurity state which separates from the O 2p states could improve the photocatalytic efficiency and we also propose a model for light electron-hole transportation which can explain the experiment results well. All these conclusions are in agreement with the recent experimental results. 相似文献
997.
Dynamic pricing is widely adopted in inventory management for perishable items, and the corresponding price adjustment cost should be taken into account. This work assumes that the price adjustment cost comprises of a fixed component and a variable one, and attempts to search for the optimal dynamic pricing strategy to maximize the firm’s profit. However, considering the fixed price adjustment cost turns this dynamic pricing problem to a non-smooth optimal control problem which cannot be solved directly by Pontryagin’s maximum principle. Hence, we first degenerate the original problem into a standard optimal control problem and calculate the corresponding solution. On the basis of this solution, we further propose a suboptimal pricing strategy which simultaneously combines static pricing and dynamic pricing strategies. The upper bound of profit gap between the suboptimal solution and the optimal one is obtained. Numerical simulation indicates that the suboptimal pricing strategy enjoys an efficient performance. 相似文献
998.
We study the initial-boundary value problem for the one dimensional EulerBoltzmann equation with reflection boundary condition. For initial data with small total variation, we use a modified Glimm scheme to construct the global approximate solutions(U_(△t,d), I_(△t,d)) and prove that there is a subsequence of the approximate solutions which is convergent to the global solution. 相似文献
999.
1000.
在强流直线感应加速器中,电子束质心位置的控制是一项重要技术,要达到较好的控制效果,前提是对电子束质心位置进行准确的测量和定位。针对具有时间分辨的电子束质心位置的测量和确定,介绍了测量实验系统的建立和数据处理两个方面的研究工作。该处理方法在实际应用时能够将电子束质心位置的误差控制在1~2个像素内。用高速分幅相机以10 ns的时间间隔、3 ns的曝光时间获得了神龙一号加速器在漂移段出口处的电子束质心运动情况。结果表明:束的质心主要在半径为0.5 mm的区域内运动,束斑直径dFWHM值分别为8.4,8.8,8.5,9.3和7.6 mm,测量结果可以为束的调控提供准确参数。 相似文献