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51.
Shape of the quantum diffusion front 总被引:1,自引:0,他引:1
Zhong J Diener RB Steck DA Oskay WH Raizen MG Plummer EW Zhang Z Niu Q 《Physical review letters》2001,86(12):2485-2489
We show that quantum diffusion has well-defined front shape. After an initial transient, the wave packet front (tails) is described by a stretched exponential P(x,t) = A(t)exp(-absolute value of [x/w](gamma)), with 1 < gamma < infinity, where w(t) is the spreading width which scales as w(t) approximately t(beta), with 0 < beta < or = 1. The two exponents satisfy the universal relation gamma = 1/(1-beta). We demonstrate these results through numerical work on one-dimensional quasiperiodic systems and the three-dimensional Anderson model of disorder. We provide an analytical derivation of these relations by using the memory function formalism of quantum dynamics. Furthermore, we present an application to experimental results for the quantum kicked rotor. 相似文献
52.
Esra Dilek Nesrin Dogancay Bulent Caglar Onur Sahin Ahmet Tabak 《Journal of Coordination Chemistry》2017,70(16):2833-2852
The mononuclear six metal(II) complexes ([Co(mef)2(3-pic)2(CH3OH)2] (1), [Ni(mef)2(3-pic)2(CH3OH)2] (2), [Cu(mef)2(3-pic)2] (3), [Co(mef)2(4-pic)2] (4), [Ni(mef)2(4-pic)2] (5), and [Cu(mef)2(4-pic)2] (6) with mefenamic acid and picoline ligands were synthesized, characterized, and their carbonic anhydrase inhibitory activities were evaluated. The six complexes were characterized by elemental analysis, FT-IR spectroscopy, and thermal analyses. The crystal structures of 1, 3, and 6 were determined by X-ray crystallography. The complexes have octahedral geometry. In 1, the mefenamato ligand behaved as monodentate whereas in 3 and 6, the mefenamato ligand acted as a bidentate ligand. Complexes 3 and 6 consist of the mefenamate and 4-picoline ligands. In 1, unlike the other complexes, methanol acted as a ligand and was involved in the coordination. Carbonic anhydrase I and II isoenzymes were purified from human erythrocytes. The in vitro effects of mefenamic acid, 3-picoline, 4-picoline, and the six metal(II) complexes on these isoenzymes were evaluated. 相似文献
53.
Mujdat Caglar Yasemin Caglar Seval Aksoy Saliha Ilican 《Applied Surface Science》2010,256(16):4966-178
Undoped and lithium (Li)-doped ZnO films were prepared by sol-gel method using spin coating technique. The effects of Li content on the crystallinity and morphological properties of ZnO films were assessed by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). XRD patterns of the films showed the hexagonal wurtzite type polycrystalline structure and that the incorporation of lithium leads to substantial changes in the structural characteristics of ZnO films. The SEM and AFM measurements showed that the surface morphology of the films was affected from the lithium incorporation. The wrinkle network was observed on the surface from both SEM and AFM results for undoped ZnO. The wrinkle structure disappeared with increasing Li content. The absorption spectra of the ZnO and 5% Li-doped ZnO (LZO5) films were carried out between 140 and 400 K temperatures. The optical band gap of ZnO and LZO5 films (calculated at various temperatures) showed a linear dependence on the temperature. The absolute zero value optical band gap and the rate of change of the band gap with temperature of the ZnO and LZO5 films were found to be 3.339 and 3.322 eV, and 2.95 × 10−4 and 1.60 × 10−4 eV/K, respectively. The transport mechanisms in the ZnO and LZO5 films have been investigated by analyzing of the temperature (80-300 K) dependence of the conductivity. The activation energies of the ZnO film increased with Li content. 相似文献
54.
Michalopoulou ZH Yardim C Gerstoft P 《The Journal of the Acoustical Society of America》2012,131(1):EL74-EL80
Seabed interface depths and fathometer amplitudes are tracked for an unknown and changing number of sub-bottom reflectors. This is achieved by incorporating conventional and adaptive fathometer processors into sequential Monte Carlo methods for a moving vertical line array. Sediment layering information and time-varying fathometer response amplitudes are tracked by using a multiple model particle filter with an uncertain number of reflectors. Results are compared to a classical particle filter where the number of reflectors is considered to be known. Reflector tracking is demonstrated for both conventional and adaptive processing applied to the drifting array data from the Boundary 2003 experiment. The layering information is successfully tracked by the multiple model particle filter even for noisy fathometer outputs. 相似文献
55.
Caglar P Tuncel SA Malcik N Landers JP Ferrance JP 《Analytical and bioanalytical chemistry》2006,386(5):1303-1312
A newly designed glass-PDMS microchip-based sensor for use in the determination of Ca2+ ions has been developed, utilizing reflectance measurements from arsenazo III (1,8-dihydroxynaphthalene-3,6-disulfonic acid-2,7-bis[(azo-2)-phenyl
arsenic acid]) immobilized on the surface of polymer beads. The beads, produced from cross-linked poly(p-chloromethylstyrene) (PCMS), were covalently modified with polyethylenimine (PEI) to which the Arsenazo III could be adsorbed.
The maximum amount of Arsenazo III which could be immobilized onto the PEI-attached PCMS beads was found to be 373.71 mg g−1 polymer at pH 1. Once fabricated, the beads were utilized at the detection point of the microfluidic sensor device with a
fiber optic assembly for reflectance measurements. Samples were mobilized past the detection point in the sensor where they
interact with the immobilized dye. The sensor could be regenerated and re-used by rinsing with HCl solution. The pH, voltage,
linear range, and the effect of interfering ions were evaluated for Ca2+ determination using this microchip sensor. At the optimum potential, 0.8 kV, and pH 9.0, the linear range of the microchip
sensor was 3.57 × 10−5 – 5.71 × 10−4 M Ca2+, with a limit of detection (LOD) of 2.68 × 10−5 M. The microchip biosensor was then applied for clinical analysis of calcium ions in serum with good results.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
56.
Atac A Karabacak M Kose E Karaca C 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,83(1):250-258
The spectroscopic properties of the nicotinamide N-oxide (abbreviated as NANO, C(6)H(6)N(2)O(2)) were examined by FT-IR, FT-Raman, NMR and UV techniques. FT-IR and FT-Raman spectra in solid state were observed in the region 4000-400 cm(-1) and 3500-50 cm(-1), respectively. The (1)H and (13)C NMR spectra were recorded in DMSO. The UV absorption spectrum of the compound that dissolved in water was recorded in the range of 200-800 nm. The structural and spectroscopic data of the molecule in the ground state were calculated by using Density Functional Theory (DFT) employing B3LYP methods with the 6-311++G(d,p) basis set. The geometry of the molecule was fully optimized, vibrational spectra were calculated and fundamental vibrations were assigned on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and PQS program. The optimized structure of compound was interpreted and compared with the reported experimental values. The observed vibrational wavenumbers, absorption wavelengths and chemical shifts were compared with calculated values. As a result, the optimized geometry and calculated spectroscopic data show a good agreement with the experimental results. 相似文献
57.
When droplets enter a junction they sort to the channel with the highest flow rate at that instant. Transport is regulated by a discrete time-delayed feedback that results in a highly periodic behavior where specific patterns can continue to cycle indefinitely. Between these highly ordered regimes are chaotic structures where no pattern is evident. Here we develop a model that describes droplet sorting under various asymmetries: branch geometry (length, cross-section), droplet resistance and pressures. First, a model is developed based on the continuum assumption and then, with the assistance of numerical simulations, a discrete model is derived to predict the length and composition of the sorting pattern. Furthermore we derive all unique sequences that are possible for a given distribution and develop a preliminary estimation of why chaotic regimes form. The model is validated by comparing it to numerical simulations and results from microfluidic experiments in PDMS chips with good agreement. 相似文献
58.
The shifts of the SiOSi stretching and the SiOAl and SiOSi bending modes, as well as the free silica peak in the IR spectra and the strengthening of the XRD reflections due to the quartz and alpha-cristobalite components of the Al-pillared bentonites (Wyoming and Resadiye), are ascribed to the formation of new SiOAl groups of covalent character. The mass losses in the temperature range 150-700 degrees C correspond to the dehydration and dehydroxylation processes. The total mass losses of the Al-pillared bentonites (Wyoming and Resadiye) are close to each other at an OH/Al ratio of 2.2, but calcination from 400 to 600 degrees C causes the surface area of the latter composite to decrease by 13%. 相似文献
59.
Fatma Karipcin Yasemin Caglar Bülent Dede 《Journal of organometallic chemistry》2007,692(12):2473-2481
4-Benzylaminobiphenylglyoxime ligand and its Cu(II) and Co(II) complexes were prepared. -bridge containing 4-benzylaminobiphenylglyoxime complexes were obtained by replacing of the bridging protons of the dioxime complexes with BF2 group. These compounds have been characterized by elemental analysis, spectroscopic (ICP-OES, infra-red) and magnetic susceptibility measurements. Thermal decomposition of the complexes is studied in nitrogen atmosphere. The final decomposition products are found to be the corresponding metal oxides. The optical constants such as optical conductivity, dielectric constant, refractive index were determined for the complexes. The analysis of the optical absorption data revealed that the band gap Eg was direct transitions. The optical dispersion parameters were determined according to Wemple and Didomenico method. 相似文献
60.
Veysel T. Yilmaz Sema Caglar William T. A. Harrison 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):m35-m38
The structures of trans‐bis[2‐(aminomethyl)pyridine‐κ2N,N′]bis(saccharinato‐κN)zinc(II), [Zn(C7H4NO3S)2(C6H8N2)2], (I), and [2‐(aminoethyl)pyridine‐κ2N,N′]bis(saccharinato‐κN)zinc(II), [Zn(C7H4NO3S)2(C7H10N2)], (II), exhibit octa‐ and tetrahedrally coordinated ZnII atoms, respectively. The diamine ligands behave as N,N′‐bidentate ligands, while saccharinate (sac) is coordinated through the N atom. In (I), the complex lies about an inversion centre with the Zn atom disordered and displaced by 0.256 (2) Å from a centre of symmetry towards a sac N atom. The crystal structure of (I) is stabilized by N—H⋯O hydrogen bonds and the crystal packing of (II) is determined by hydrogen bonding as well as weak π–π stacking interactions between the sac ligands. 相似文献