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Summary The relative X-ray fluorescence (XRF) intensities for annular source and various annular specimen are measured with a Ge-Li
detection system and calculated by the Monte Carlo numerical techniques (MCNT).Kα X-ray intensities of annular specimens with different radii prepared from a pure-molybdenum foil are measured and it is
seen that the measured values are in good agreement with the values calculated by MCNT. The variation of the fluorescence
intensity due to the collimator radius is also studied. The differences between the MCNT and experimental results are discussed
in terms of the possible sources of errors. 相似文献
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A discrete variable representation (DVR) made from distributed Gaussians gn(x) = e, (n = ?∞, …, ∞) and its infinite grid limit is described. The infinite grid limit of the distributed Gaussian DVR (DGDVR) reduces to the sinc function DVR of Colbert and Miller in the limit c → 0. The numerical performance of both finite and infinite grid DGDVRs and the sinc function DVR is compared. If a small number of quadrature points are taken, the finite grid DGDVR performs much better than both infinite grid DGDVR and sinc function DVR. The infinite grid DVRs lose accuracy due to the truncation error. In contrast, the sinc function DVR is found to be superior to both finite and infinite grid DGDVRs if enough grid points are taken to eliminate the truncation error. In particular, the accuracy of DGDVRs does not get better than some limit when the distance between Gaussians d goes to zero with fixed c, whereas the accuracy of the sinc function DVR improves very quickly as d becomes smaller, and the results are exact in the limit d → 0. An analysis of the performance of distributed basis functions to represent a given function is presented in a recent publication. With this analysis, we explain why the sinc function DVR performs better than the infinite grid DGDVR. The analysis also traces the inability of Gaussians to yield exact results in the limit d → 0 to the incompleteness of this basis in this limit. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005 相似文献
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E. M. Köksal N. Çelebi B. Ataksor A. Ulug M. Taşdelen G. Kopuz B. Akar M. T. Karabulut 《Journal of Radioanalytical and Nuclear Chemistry》2004,259(2):213-216
As part of a national program to determine public exposure to natural radiation, indoor air 222Rn concentrations were determined in dwellings of Turkey. The 222Rn concentrations were measured with time-integrating passive nuclear etched track detectors in 27 provincial centers. The
indoor radon concentrations were found to be in the range of 10-380 Bq.m-3.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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Margaux Fresnais Seda Karabulut Yasmin Abou Zeed Johannes Ungermann Julia Benzel Kristian W. Pajtler Stefan M. Pfister Walter E. Haefeli Jürgen Burhenne Rmi Longuespe 《Molecules (Basel, Switzerland)》2022,27(3)
Desorption/ionization mass spectrometry (DI-MS) approaches allow for the rapid quantification of drugs in biological matrices using assays that can be validated according to regulatory guidelines. However, specific adaptations must be applied to create reliable quantification methods, depending on the approach and instrumentation used. In the present article, we demonstrate the importance of the molecular weight, the fragmentation pattern, and the purity of the internal standard for the development of matrix-assisted laser desorption/ionization (MALDI)-ion mobility (IM)-tandem MS and MS/MS methods. We present preliminary results of method development for the quantification of selinexor in microdialysis fluids with a stable isotopically labeled internal standard. In addition, we discuss the selection of internal standards for MALDI-MS assays using different instrumentations. 相似文献
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İ. Karabulut Ü. Atav H. Şafak M. Tomak 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,55(3):283-288
The linear and nonlinear intersubband optical absorptions
in AlxlGa1-xlAs/GaAs/Alxr Ga1-xrAs asymmetric rectangular
quantum well are studied within the framework of the density matrix
formalism. We have calculated the electron energy levels and the envelope
wave functions using the effective mass approach. In addition, we have
obtained an expression for saturation intensity. It is shown that the
parameters such as asymmetry and width of potential well not only shift the
peak positions in absorption spectrum but also considerably modify their
height. These results suggest that the absorption process can be easily
controlled by the structure parameters of an asymmetric rectangular quantum
well. Also, the incident optical intensity has a great effect on the total
absorption spectrum. We have seen that the absorption peak is reduced by
half when the optical intensity is approximately 0.8 MW/cm2 for well
width L=90 ? and β=0.5. Moreover, it is seen that the
saturation intensity is quite sensitive to the structure parameters of an
asymmetric rectangular quantum well. Thus, the results presented here can be
useful for electro-optical modulators and photodetectors in the infrared
region. 相似文献
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Emel Yildiz Sadet Karabulut Neslihan S. Pinar Yusuf Karatas Figen Doran 《无机化学学报》2010,26(10):1743-1749
3,3,4,7-四羟基黄酮与1,3-二环己基碳二亚胺在4-二甲胺吡啶存在下反应,得到2,2-双(3,3,4,7-四羟基黄酮)1,3-二环己基碳二亚胺。三价金属离子与上述合成得到的配体螯合,对此四面体结构的双核Fe(Ⅲ)配合物的血液学及病理学数据进行了讨论,同时研究了合成的配体作为螯合剂清除鼠肝胰组织中超载的铁的能力。结果表明作为口服药其作为双齿配体的螯合能力与市售用于治疗地中海贫血的药物"去铁敏"相近。 相似文献
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Christian Hammer Benjamin Walther Hikmet Karabulut Manuel M. Lohrengel 《Journal of Solid State Electrochemistry》2011,15(9):1885-1891
Anodic Ta oxide films are said to inhibit oxygen evolution. In industry, however, large amounts of gas are evolved during
the anodization of tantalum anodes for electrolytic capacitor fabrication. We quantified the oxygen by fluorescence quenching
in a flow-through cuvette and found that 4% of the anodic charge are consumed for oxygen evolution. In wires or sheets, this
oxygen is removed by diffusion without bubble formation and, thus, not recognized. Due to the large inner area of the sintered
Ta anodes, the oxygen evolution causes strong oscillations of the current density and bubble formation. The amount of oxygen
is proportional to the oxide amount formed in parallel. This is explained by a model where mobile ions during oxide growth
form interband states which allow electron tunneling. Accordingly, stationary no oxygen evolution is observed. 相似文献
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