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1.
Europium (Eu+) ions were confined in a Paul trap and detected by non-destructive method. Storage time of Eu+ ions achieved in vacuum was improved by orders of magnitude employing buffer gas cooling. The experimentally detected signal
was fitted to the ion response signal and the total number of ions trapped was estimated. It is found that the peak signal
amplitude as well as the product of FWHM and the peak signal amplitude is proportional to the total number of trapped ions.
The trapped ion secular frequency was swept at different rates and its effect on the absorption line profile was studied both
experimentally and theoretically. 相似文献
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Summary A column chromatography was developed using a nonionic, polar adsorbent resin Amberlite XAD-7 for routine radiochemical separation of 67Ga from Zn and Cu. 7M HCl was found to be the optimum concentration for adsorption of 67Ga and elution of both Zn and Cu. Distilled water was used for elution of 67Ga from the column. The optimum flow rate of the solutions on to the column was 5 ml/min. The concentrations of Zn and Cu in the final product (30 ml), measured by a polarography method, were 2.0 and 0.5 ppm, respectively. A solvent extraction method, using diisopropyl ether/7M HCl system was also tested to perform the same separation and a comparison between the two methods was made. The radiochemical chromatographic separation system is simple in design and easy to operate for separations in a hot cell. 相似文献
4.
Cold expansion is a useful process for imposing compressive residual stresses around the holes in riveted and bolted connections. These stresses increase the fatigue life of holed parts. Distribution and amount of exerted residual stress dependent on various parameters as material, distance of adjacent holes, hole diameter, cold expansion ratio and plate thickness. In this study, experimental and numerical results for two different aluminum alloys and various holes distances are investigated and compared. Effects of mentioned parameters on the residual stress are studied. 相似文献
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Amirali Sadeqi Shapour Moradi Kourosh Heidari Shirazi 《Mathematical and Computer Modelling of Dynamical Systems: Methods, Tools and Applications in Engineering and Related Sciences》2020,26(1):55-79
ABSTRACTThe scope of output-only/blind identification is restricted to stochastic/statistical processes, but for the first time in this study, the detectability conditions for general output-only subspace identification are investigated. This aids the range of input sources to be extended in a much realistic manner, beyond the only stochastic inputs. For this purpose, the subspace framework is assigned to make a connection between the output signal contents and the LTI system order. A few substantial hypotheses and algebraic statements are propounded affirming the sufficiency of the genuine output sequences for the identification purpose. This can be perceived as the cornerstone of state-space model reconstruction. In order to consolidate the notions according to reality, several examples are studied and examined for different input classes with stochastic disturbance. 相似文献
7.
Rahim Hekmatshoar Akram Rezaei S. Y. Shirazi Beheshtiha 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):2491-2496
Synthesis of substituted coumarin-3-carboxylic acid via Knoevenagel condensation of meldrum's acid with ortho-hydroxyaryl aldehydes in solventless system is described. 相似文献
8.
Shirazi Muhammad Faizan Wijesinghe Ruchire Eranga Ravichandran Naresh Kumar Kim Pilun Jeon Mansik Kim Jeehyun 《Optical Review》2017,24(2):219-225
Optical Review - A dual-path handheld system is proposed for cornea and retina imaging using spectral domain optical coherence tomography. The handheld sample arm is designed to acquire two images... 相似文献
9.
Fernando Castañeda Paul Silva M. Teresa Garland Ata Shirazi Clifford A. Bunton 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):2152-2168
The phosphonium ylidic diesters, methyl and ethyl isopropyl and, methyl and ethyl t-butyl triphenylphosphoranylidene malonates, 1a,b and 2a,b , respectively, have the syn-anti conformation in solution, as in the crystal, and the bulkier alkoxy group is oriented towards phosphorus. The 1 H NMR spectra show that in 1a,b , the isopropyl group is oriented towards the face of a phenyl group, consistent with π shielding in the 1 H signals, and examination of the 1 H coupled 13 C NMR spectra allows assignment of the acyl carbon signals. Computed bond lengths and angles for isolated molecules are similar to those in the crystal, and the geometry and the NMR spectra indicate extensive ylidic resonance. Estimated partial atomic charges on the ester oxygens are more negative when they are oriented towards, rather than away from, phosphorus. 相似文献
10.
Farnoush Mousavizadeh Seyed Yahya Shirazi Beheshtiha Reyhaneh Rahnamafar 《合成通讯》2014,44(10):1483-1491
A facile protocol for the one-pot, multicomponent reaction of indole, 4-hydroxycoumarin, and aromatic aldehydes was developed using copper octoate as an inexpensive, commercially available, and efficient catalyst. This highly selective reaction eliminates the formation of homodimeric by-products (bisindoles and biscoumarins) and selectively results in the formation of heterodimeric adducts containing both indole and coumarin heterocycles. 相似文献