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101.
Shi S. K. Kang R. Q. Li J. L. Bai Y. Dang D. B. 《Russian Journal of Coordination Chemistry》2020,46(7):513-520
Russian Journal of Coordination Chemistry - A new V-centered Keggin polyoxometalate-based inorganic-organic hybrid (HPpz)3[VW12O40] (I) (Ppz = piperazine) has been hydrothermal synthesized and... 相似文献
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Jun Dang Yurong Du Qi Wang YangZom Dawa Chengbiao Chen Qilan Wang Jianbin Ma Yanduo Tao 《Journal of separation science》2020,43(16):3233-3241
Reversed‐phase liquid chromatography coupled with middle chromatogram isolated gel column was employed for the efficient preparative separation of the arylbutanoid‐type phenol [(‐)‐rhododendrin] from Saxifraga tangutica. Universal C18 (XTerra C18) and XCharge C18 columns were compared for (‐)‐rhododendrin fraction analysis and preparation. Although tailing and overloading occurred on the XTerra C18 column, the positively charged reversed‐phase C18 column (XCharge C18) overcame these drawbacks, allowing for favorable separation resolution, even when loading at a on a preparative scale (3.69 mg per injection). The general separation process was as follows. First, 365.0 mg of crude (‐)‐rhododendrin was enriched from 165 g Saxifraga tangutica extract via a middle chromatogram isolated gel column. Second, separation was performed on an XTerra C18 preparative column, from which 73.8 mg of the target fraction was easily obtained. Finally, the 24.0 mg tailing peak of (‐)‐rhododendrin on XTerra C18 column was selectively purified on the XCharge C18 analytical column. These results demonstrate that the tailing nonalkaloid peaks can be effectively used for preparative isolation on XCharge C18 columns. 相似文献
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Andy K. W. Ma Ali A. Alghamdi Kassem Tofailli Nicholas M. Spyrou 《Journal of Radioanalytical and Nuclear Chemistry》2012,291(2):353-357
Early detection of the red palm weevils (RPW) is a major challenge in agriculture among all kinds of palm trees due to the
nature of the insect and the difficulty to trace them through their life stages associated with the tree life. Many methods
have been applied for the weevil detection such as X-ray diffraction techniques, fluoroscopy and ultrasound. On the other
hand, the idea of tomography has been used for other purposes such as the determination of the age of the tree and for applied
environmental studies. Such technology can also reveal the weevil in principle. In this study, we explore the use of X-ray
CT for weevil detection with the Monte Carlo method. A model of the stem of a palm tree is developed for simulations. MCNPX
is chosen to carry out the simulations for the radiography tally in the code. The tally records the 2D data of the X-ray beams
irradiating the tree model. An iterative reconstruction method for cone beam CT is applied to obtain the 3D slices of the
tree model. We are exploring the minimum number of projection angles and the detectability of the weevil. We shall also report
the sensitivity of weevil detection using X-ray CT with a large set of simulations with different weevil sizes and tree diameters. 相似文献
106.
Andy Buckley Hendrik Hoeth Heiko Lacker Holger Schulz Jan Eike von Seggern 《The European Physical Journal C - Particles and Fields》2010,65(1-2):331-357
In this article we describe Professor, a new program for tuning model parameters of Monte Carlo event generators to experimental data by parameterising the per-bin generator response to parameter variations and numerically optimising the parameterised behaviour. Simulated experimental analysis data is obtained using the Rivet analysis toolkit. This paper presents the Professor procedure and implementation, illustrated with the application of the method to tunes of the Pythia 6 event generator to data from the LEP/SLD and Tevatron experiments. These tunes are substantial improvements on existing standard choices, and are recommended as base tunes for LHC experiments, to be themselves systematically improved upon when early LHC data is available. 相似文献
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