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排序方式: 共有133条查询结果,搜索用时 15 毫秒
81.
In this paper we present a product system and give a representation for consine functions with the system. Based on the formula two new algorithms are designed for computing the Discrete Cosine Transform. Both algorithms have regular recursive structure and good numerical stability and are easy to parallize. 相似文献
82.
This study established a rapid and reliable approach using liquid chromatography–tandem mass spectrometry for the simultaneous determination of cinnamic acid, vanillic acid and protocatechuic acid in rat plasma. This is the first report on a comparative pharmacokinetic study of dispensing granules and standard decoction of Cinnamomum cassia twigs in rats. After liquid–liquid extraction by ethyl acetate, the plasma samples were subjected to LC–MS/MS for multiple reaction monitoring. The standard curves showed good linear regression (r2 > 0.9991) in the range of 10.0–16000 ng/mL. The intra‐ and inter‐day accuracy and precision were found to be within 15% of the nominal concentration. The recoveries of the three phenolics ranged from 88.7 to 105.7%. Finally, this approach was successfully applied to pharmacokinetic analysis of the three phenolics after oral administration of standard decoction and dispensing granules of C. cassia twigs in rats. Although the values of AUC0–t of vanillic acid and protocatechuic acid in standard decoction group were larger than those of the dispensing granule group, no significant difference was observed for the two groups. Of note, the elimination rates of vanillic acid were slower in the standard decoction group than the dispensing granule group. 相似文献
83.
A simple and reliable liquid chromatography–mass spectrometry (LC–MS) method was developed for simultaneous determination of saikosaponin A, saikosaponin B1, saikosaponin C, saikosaponin D and saikosaponin F in rat plasma using glycyrrhetinic acid as an internal standard (IS). The separation was operated on a Waters BEH C18 column. The mobile phases of gradient elution consisted of acetonitrile (A) and 0.1% aqueous acetic acid (B). The mass spectrometric detection was accomplished in multiple reaction monitoring mode. The five saponins displayed good linearity (r2 > 0.9996). The lower limits of quantitation of saikosaponin A, saikosaponin B1, saikosaponin C, saikosaponin D and saikosaponin F were determined to be 2.9, 2.3, 3.5, 2.9 and 3.1 ng/mL, respectively. Moreover, the intra‐ and inter‐day precisions of the five saponins showed an RSD within 2.96%, whereas the accuracy (RE) ranged from ?2.28 to 2.78%. Finally, the developed method was fully validated and applied to a comparative pharmacokinetic study of the five bioactive saponins in rats following oral administration of crude and vinegar‐processed Bupleurum scorzonerifolium. 相似文献
84.
85.
In this paper, a novel lattice Boltzmann model is proposed to solve the Poisson equation through modifying equilibrium distribution function. Compared with previous models, which can be viewed as the solvers to diffusion equation, the present model is a genuine solver to the Poisson equation, and the transient term derived by previous models is eliminated. Numerical solutions agree well with analytical solutions, which indicates the potential of the present model for solving the Poisson equation. 相似文献
86.
The optical path difference (OPD) of the static polarization interference imaging spectrometer and wide-field-of-view polarization interference imaging spectrometer are calculated and analyzed, simultaneously. The analysis results show that the actual total OPD contains two parts, the Savart polariscope introduces the first part, and the second part is introduced when imaging lens reunites two beams in its focal plane. Since the first part OPD accounts for about half of the actual total OPD, it has influences on the resulting spectrum and thus cannot be neglected. The influences of the uniaxial crystal dispersion on the OPD and resulting spectrum are analyzed, and the results show that the OPD decreased with the wavelength, the spectral resolution increased with the wavelength. There are no fixed spectral resolution over the entire detection spectral region, and the spectral resolution would become worse with the increase of the wavelength. 相似文献
87.
Quantitative evaluation main of the components in Paeoniae Radix Alba–Atractylodis Macrocephalae Rhizoma herbal pair by high‐performance liquid chromatography 下载免费PDF全文
The aim of this study was to investigate the influence of compatibility on the contents of main compounds in Paeoniae Radix Alba and Atractylodis Macrocephalae Rhizoma. Ten compounds were separated on an Inertsil ODS‐SP Extend C18 column (250 mm × 4.6 mm, 5 μm) and detected by a diode array detector with the mobile phase consisting of aqueous phosphoric acid (0.1%, v/v; A) and acetonitrile (B) by linear gradient elution. All analytes showed good linearity over a wide concentration range (r2 ≥ 0.9989). The limits of detection and quantification were <8.10 and 10.80 μg/mL, respectively. The intra‐ and interday variations were <4.36%. The average recoveries were observed from 94.90 to 103.38%, with relative standard deviation ranging from 1.23 to 3.15% for the analytes. The established method was reliable enough for global quality evaluation of Paeoniae Radix Alba, Atractylodis Macrocephalae Rhizoma, and their co‐decoctions. 相似文献
88.
空间调制干涉成像光谱技术 总被引:48,自引:11,他引:48
介绍空间调制干涉成像光谱技术,提出基于实体迈克尔干涉仪的空间调制干涉成像光谱仪,推导了这种仪器的基本几何参数公式与主要误差容限计算公式,总结了其主要特点。文中还归纳出高通量大视场干涉仪原理模型。 相似文献
89.
在以前的论文中,我们从计算机模拟实验及相关的光学现象出发提出了Fabry-Perot(以下简称F-P)干涉光谱技术中的积分方程∫б1б2(x,б)do=I(x)数值求解的稳定条件。本文将进一步从数学上利用积分方程的本征值理论阐明这些稳定条件产生的原因,从而为F-P干涉光谱技术奠定坚实的基础。 相似文献
90.