Role of the cluster deformations in explaining the exotic decay half-lives

We investigate the influence of nuclear deformations of the cluster and daughter nuclei on the exotic cluster decay half-lives of $\ensuremath 221\leq A \leq 242$ for the favored cluster decay of the radioactive nuclei by using the semiclassical WKB method and the Bohr-Sommerfeld quantization condition. The results have also been presented for the spherical nuclei case in order to show clearly the effects of the deformations on the exotic decay half-lives. The half-lives become close to the experimental data when both the deformation of daughter and cluster nuclei are taken into account in the calculations. Furthermore, considering cluster deformations together with the orientation angles of daughter and cluster also provides positive contributions to the results.     

p-Hertz excitation spectroscopy of an optical antenna, optical transmitter-receiver mechanism

o-Xylene sensitized biacetyl fluorescence and phosphorescence have been investigated and photosensitized fluorescence and phosphorescence lifetimes of biacetyl in the vapor phase have been determined. Attempts to detect the triplet of biacetyl by its absorption spectrum were unsuccessful, primarily due to, it is believed, the low extinction coefficients of the triplet, and the low triplet concentrations produced by the optical pumping device at room temperature.     

Electrocatalytical Application of Platinum Nanoparticles Supported on Reduced Graphene Oxide in PEM Fuel Cell: Effect of Reducing Agents of Dimethlyformamide or Hydrazine Hydrate on the Properties

Two kinds of reduced graphene oxide (rGO) were synthesized with the reducing agents of either dimethylformamide (DMF) or hydrazine hydrate (HYD). The decoration of platinum nanoparticles (Pt NPs) over these materials was provided by microwave irradiation (MWI) method. Detailed physical and electrochemical measurements were carried out. Based on the electrochemical results of both catalysts, it is not surprising the achievement of higher electrochemical active surface area (ECSA), higher oxygen reduction reaction (ORR) activity, higher electron transfer number, lower charge transfer resistance and higher fuel cell performance with the Pt/rGO (DMF) catalyst which surpasses Pt/rGO (HYD) in many ways.     

Singlet-singlet intermolecular optical energy transfer from naphthalene to benzophenone in the vapor phase

By using the exothermic energy transfer as a function of pressure, the rate constant for diffusion was evaluated for benzophenone/naphthalene and naphthalene/benzophenone systems. In principle the optical energy absorbed by a complex molecule raises that molecule to one of its excited states, and afterwards this excitation energy decays through the different relaxation channels. Initially, electronically excited naphthalene "S1" state emits photons in the fluorescence band of naphthalene and these emitted photons, as a stream of particles, are absorbed by the acceptor molecule benzophenone, then excited benzophenone fluoresces. In this investigation, sensitized fluorescence decay times in different conditions were measured for naphthalene-benzophenone system in the vapor phase, and found to be 12+/-1 ns. The ultraviolet-visible spectra of the system in the vapor phase at room temperature conditions were broad and structureless.     

Synthesis,Characterization and Investigation of Electrochemical and Spectroelectrochemical Properties of Peripherally Tetra Diethoxypropan Substituted Phthalocyanines

In this study novel peripherally tetra 1,3-diethoxy-2-propanol substituted Co(II), Cu(II), Mg(II), Ni(II) Zn(II) phthalocyanine derivatives were prepared. The characterization of the novel compounds was made by FT-IR, ¹H-NMR, UV-vis and MALDI-TOF mass. Electrochemical, in-situ spectroelectrochemical and electrocolorimetric measurements have been carried out with the aim to determine the redox properties, to illuminate reaction mechanism and the effect of substituent and metal center. Moreover, the color properties and aggregation tendency of compounds were also investigated.     

Spectral image analysis for the absorption bands of the beta-methallyl free radical in the vapor phase

The radicals formed in the flash photolysis of 2-methylbut-1-ene and subsequent reactions have been investigated by kinetic spectroscopy and gas liquid chromatography. Less than 10% of photo products are formed by a molecular made of fission of the excited olefin, and of the radical modes the relative probabilities of band fission, beta(CH):beta(CH):alpha(CC) are 13:1.37:1. The extinction coefficients of beta-methallyl radical measured experimentally for all the absorption bands. The decay of the beta-methallyl radical was second order. The rate constant for the beta-methallyl radical recombination experimentally measured was 2.6+/-0.3 x 10(10) l mol(-1)s(-1) at 295+/-2K. The spectrum image showing the absorption bands was examined by image processing techniques in order to improve the visual experience of each band by localizing to a specific region of interest. Experimental results illustrate how the exact location of absorption bands was clearly extracted from the spectral image and further improvements in the visual detection of absorption bands.     

Structure elucidation of laser dye coumarin-540A by joint application of X-ray diffraction, X-ray fluorescence, prompt fluorescence, UV and visible spectroscopy

X-ray, ultraviolet, and visible light induced photophysical changes of coumarin-540A in ethanol have been studied by the joint applications of X-ray, ultraviolet, and visible spectroscopy. Some impurities were found by X-ray fluorescence measurements. During the high power optical pumping, coumarin showed photochemical changes. Photoproduct emission spectra characteristics showed that photoproduct molecules can also be used as a laser dye at a different emission frequency in the ultraviolet region.     

Yotta-photonic excitation spectroscopy of salicylidene-m-bromo-aniline

The observation of triplet-triplet absorption and emission spectra of salicylidene-m-bromo-aniline in solution, is complicated by the possible colored isomer formation during the optical pumping for yotta-photonic excitation at room temperature. The short-lived (singlet-singlet) and long-lived (triplet-triplet) absorption spectra were recorded phographically by microsecond flash and nano-second laser flash photolysis techniques. Salicylidene-m-bromo-aniline complexes were purified by repeated recrystallization until further recrystallization produced no further changes for X-ray diffraction pattern and optical absorption, emission properties. For yotta-photon excitation system, light could be faster than usual, because of heat and to many photonic collisions in the cavity, slowed down by the molecule, and stopped or frozen in a molecular orbital for a short time from nano-second to atto-second. The physical properties of the absorbed photons, in a very high photon flux density (i.e. in a photon field) are different in photonic character, and the emitted photons by the excited states behaves differently in photon field, no splitting occurs for the absorbed or emitted lines like in electrical or magnetic fields.     

Synthesis, photophysical and photochemical properties of highly soluble phthalocyanines substituted with four 3,5-dimethylpyrazole-1-methoxy groups

The synthesis and characterization of new peripherally tetra-3,5-dimethylpyrazole-1-methoxy substituted metal-free (4), zinc (5), nickel (6), cobalt (7), copper (8) and lead (9) phthalocyanines are described for the first time in this study. The photophysical (fluorescence quantum yields and fluorescence lifetimes) and photochemical (photodegradation and singlet oxygen quantum yields) properties of metal-free (4), zinc (5) and lead (9) phthalocyanines are studied in dimethylsulfoxide (DMSO). Nickel (6), cobalt (7) and copper (8) phthalocyanines (6-8) did not evaluate for this purpose due to transition metal and paramagnetic behavior of central metals in the phthalocyanine cavity. The fluorescence quenching behavior of metal-free (4), zinc (5) and lead (9) phthalocyanines are also investigated. The fluorescence emissions of these phthalocyanines are effectively quenched by 1,4-benzoquinone in DMSO.     

Size-controlled electrochemical growth of PbS nanostructures into electrochemically patterned self-assembled monolayers

1-Hexadecanethiol self-assembled monolayers (HDT SAMs) on Au(111) were used as a molecular resist to fabricate nanosized patterns by electrochemical reductive partial desorption for subsequent electrodeposition of PbS from the same solution simultaneously. The influences of potential steps of variable pulse width and amplitude on the size and the number of patterns were investigated. The kinetics of pattern formation by reductive desorption appears to be instantaneous according to chronoamperometric and morphological investigations. PbS structures were deposited electrochemically into the patterns on HDT SAMs by a combined electrochemical technique, based on the codeposition from the same saturated PbS solution at the underpotential deposition of Pb and S. Scanning tunneling microscopy measurements showed that all of the PbS deposits were disk shaped and uniformly distributed on Au(111) surfaces. Preliminary results indicated that the diameter and the density of PbS deposits can be controlled by controlling the pulse width and amplitude of potential applied at the reductive removal stage of HDT SAMs and the deposition time during the electrochemical deposition step.