Effect of polarization on population transfer in H2 by stimulated Raman transition with partially overlapping laser pulses

Polarization effects on population transfer by stimulated Raman transition using overlapping time dependent pump and Stokes laser pulses from the ground X ¹Σ _g ^/+ (v _g=0, J _g=1) level of H₂ to the final X ¹Σ _g ^/+ (v _f=1, J _f=1) level via the intermediate B ¹Σ _u ^/+ (v _i=14, J _i=0,2), C ¹Π _u ^/+ (v _i=3, J _i=2) and C ¹Π _u ^/− (v _i=3, J _i=1) levels have been theoretically investigated by applying the density matrix formalism. We have studied in detail the dependence of the population transfer on time delay between two pulses for the cases of on-resonance excitations considering linear parallel and same-sense circular polarizations of the fields. The pump and Stokes fields are taken as having Gaussian pulse shapes with peak intensities I _P ^/0 (I _S ^/0 )=2 × 10⁶ and 1 × 10⁷ W/cm². Density matrix equations have been solved for each value of the magnetic quantum number M _g(0, ±1) of the initial ground level taking into account the M _g dependence of the Rabi frequencies. M _g — averaged population transfer to the final level has also been calculated. For resonance excitations to the B(14, 0) or C(3, 1) levels, appreciable population transfer is achieved for intuitive pulse order for some particular values of M _g and M _i (magnetic quantum number of the resonant intermediate level) depending on the nature of polarizations. The calculated values of M _g — averaged population transfer for the two cases of polarizations show that for on-resonance excitation to the B(14, 0) or the C(3, 1) level, linear parallel polarization of the laser fields yield more transfer efficiency whereas for resonance excitation to the B(14, 2) level, larger population transfer results from the same-sense circular polarizations. For resonance excitation to the C(3, 2) level, M _g — averaged population is found to be almost polarization independent. The calculations for the six-level H₂ system reveal some interesting features of polarization effects on the population transfer efficiency.     

Electrochemical Aptasensors for Biological and Chemical Analyte Detection

Aptamers are short length, single-stranded DNA or RNA affinity molecules which interact with any desired targets such as biomarkers, cells, biological molecules, drugs or chemicals with high sensitivity. They have been extensively employed for medical applications due to having more advantages than the antibodies such as easier preparation and modification, higher stability, lower batch-to-batch variability and cost. Moreover, aptamers can be easily integrated efficiently with sensors, biosensors, actuators and other devices. In this review article, different applications of aptamers for biological and chemical molecules detection within the scope of electrochemical methods were presented with recent studies. In addition, the present status and future perspectives for highly-effective aptasensors for specific and selective analyte detection were discussed. As in stated throughout the review, combining of extraordinary properties of aptamers with the electrochemical-based biosensors could have improved the sensitivity of the assay and reduced limit of detection.     

Synthesis,structures, photophysical properties,and catalytic characteristics of 2,9-dimesityl-1,10-phenanthroline (dmesp) transition metal complexes

The syntheses of the 2,9-dimesityl-1,10-phenanthroline ( dmesp ) metal complexes, [Cu(dmesp)(MeCN)]PF₆ ( 1 ), [Cu(dmesp)₂]PF₆ ( 2 ), Fe(dmesp)Cl₂ ( 3 ), Co(dmesp)Cl₂ ( 4 ), Ni(dmesp)Cl₂ ( 5 ), Zn(dmesp)Cl₂ ( 6 ), Pd(dmesp)MeCl ( 7 ), Cu(dmesp)Cl ( 8 ), and Pd(dmesp)₂Cl₂ ( 9 ), in good to high yields are described. These complexes were characterized by ¹H and ¹³C NMR spectroscopy, HR–MS (ESI and/or APPI), and elemental analysis (CHN). The solid-state structures of complexes 1 – 8 were determined by single-crystal X-ray analysis and their photophysical properties were also characterized. To demonstrate the versatility of this new platform, complexes 3 – 5 , 8 , and 9 were employed in the catalytic oligomerization of ethylene using modified methyl aluminoxane (MMAO) as the cocatalyst, where Co(II) and Ni(II) complexes ( 4 and 5 , respectively) were found to exhibit moderate selectivity for catalytic dimerization of ethylene to butenes over tri- or tetramerization. Complex 8 is an effective catalyst of both the commonly encountered “click” reaction and amine arylation chemistries. Complexes 6 and 9 were found to be excellent catalysts for Friedel-Crafts alkylation and Suzuki-Miyaura coupling, respectively.     

Optically stimulated luminescence dating of Holocene alluvial fans,East Anatolian Fault System,Turkey

In this study, the optically stimulated luminescence dating technique was used to determine the time of deposition of alluvial sediment samples from the Türko?lu-Antakya segment of the East Anatolian Fault System (EAFS) in Turkey. The double-single aliquot regenerative dose protocol on fine grain samples was used to estimate equivalent doses (D_e). Annual dose rate was computed using elemental concentration of uranium (U) and thorium (Th) determined by using thick-source alpha counting and potassium (K) concentrations using X-ray fluorescence and/or atomic absorption spectroscopy. The environmental dose was measured in situ using α-Al₂O₃:C chips inside plastic tubes for a year. The two different bulk sediment samples collected from the Islahiye trench yielded ages of 4.54?±?0.28 and 2.91?±?0.23?ka. We also obtained a 2.60?±?0.18?ka age for the alluvial deposit in the K?ranyurdu trench and 2.31?±?0.14?ka age for an excavation area called Malzeme Oca??. These ages were consistent with the corresponding calibrated Carbon-14 (¹⁴C) ages of the region. The differences between the determined ages were insufficient to clearly distinguish the disturbance event from the effects of bioturbation, biological mixing, or other sources of D_e variation in the region. They provide a record of alluvial aggradation in the region and may determine undocumented historical earthquake events.     

THE HADAMARD INEQUALITY FOR CONVEX FUNCTION VIA FRACTIONAL INTEGRALS

In this paper, we establish several inequalities for some differantiable mappings that are connected with the Riemann-Liouville fractional integrals. The analysis used in the proofs is fairly elementar...     

Experimental and theoretical studies on the identification of p-biphenyloxycarbonylphenyl acrylate

This study presents the identification of a title compound, p-biphenyloxycarbonylphenyl acrylate by means of experimental and theoretical evidences. The spectroscopic properties of the compound were experimentally investigated by Fourier transformation-infrared spectra (in the region 400-4000 cm(-1)) and nuclear magnetic resonance (NMR) chemical shifts (with a frequency of 400 MHz). Moreover, the optimized molecular structures, vibrational frequencies including infrared intensities and Raman activities, corresponding vibrational spectra interpreted with the aid of normal coordinate analysis based on scaled density functional force field, thermodynamic properties, atomic charges and ultraviolet-visible (UV-vis) spectra were analyzed utilizing ab initio Hartree-Fock (HF) and Density Functional Theory (B3LYP) methods at 6-31G(d,p) calculation level. It was found that the vibrational frequencies and chemical shifts obtained were shown to have a good agreement with available experimental results. We not only simulated frontier molecular orbitals (FMO) and molecular electrostatic potential (MEP) but also evaluated the transition state and energy band gap clearly.     

Queue length estimation from probe vehicle location and the impacts of sample size

Probe vehicles are increasingly receiving more attention as an alternative means of collecting real-time traffic data needed for system optimization. This paper focuses on real-time estimation of queue lengths from the location information of probe vehicles in a queue at an isolated and undersaturated intersection. The paper also addresses the evaluation of the accuracy of such estimates as a function of the market penetration of probe vehicles. An analytical formulation based on conditional probability distributions is developed for estimating the expected queue length and its variance. It is found that, for the given settings, only the location information of the last probe vehicle in the queue is sufficient for the estimation. Exact expressions for the conditional mean and variance of queue length are derived. Various numerical results are documented to show how estimation errors behave by the volume to capacity ratio and by market penetration.     

THE SINGULARLY PERTURBED NONLOCAL REACTION DIFFUSION SYSTEM

In this paper the singularly perturbed initial boundary value problems for the nonlocal reaction diffusion system are considered. Unsing the iteration method and the comparison theorem, the existence, uniqueness and its asymptotic behavior of solution for the problem are studied.     

Analytic evaluation of periodic responses of a forced nonlinear oscillator

The periodic responses of a strongly nonlinear, single-degree-of-freedom forced oscillator with weak excitation and damping are examined. The presented methodology is based on a regular perturbation expansion, whose first term is the solution of the unforced, and undamped nonlinear problem. Higher order approximations are computed by explicitly solving linear differential equations possessing a periodically varying coefficient. The general theory is used for studying the periodic steady state motions of the periodically forced system. Moreover, it is shown that the presented analysis can be used to analytically study the orbital stability of the identified steady state motions. The proposed method can also be used for studying periodic responses due to nonperiodic transient forces, provided that these responses are close to the O(1) periodic generating solution.