pH Dependence of Surface Enhanced FT-Raman Scattering of Ω-Mercaptoalkanols on Silver Surface

Fourier transform surface enhanced Raman spectrometer is used to characterize Ω-mercaptoalkanols (HO(CH₂)_nSH, n=2, 6) chemisorption on silver surface from their aqueous solution of different pH values.     

VIBRATIONAL SPECTRA AND NORMAL COORDINATE ANALYSIS OF 1,2-BIS(2-FORMYLGLYCINEBENZENESULFENYL) ETHANE Pd(II) DICHLORIDE COMPLEX

The normal coordinate analysis of the title complex, 1,2-bis(2-formylglycinebenzenesulfenyl) ethane Pd(II) dichloride has been carried out by using the Urey-Bradley force field. According to the molecular structure determined by x-ray crystallographic analysis, 182 internal coordinates were established and 112 theoretical vibration frequencies agree well with the observed values with the average difference of 2.53 cm^?1 and the maximum deviation of 16.0 cm^?1.     

Challenges in uncovering the origin of the proton's spin

One of the most fascinating challenges facing modern strong interaction physics is to understand the origin of the spin of the nucleon in terms of the spin and orbital angular momentum of the quarks and gluons. We review recent progress on this problem as well as some of the uncertainties associated with state of the art lattice QCD simulations. In particular, we explain the importance of the corrections associated with chiral extrapolation and finite volume corrections, especially for the term B(0) extracted from the appropriate low moment of the deeply virtual Compton scattering amplitude.     

Dynamic light scattering study of the ultrasonication of P(VDF-TrFE): A new model

The purpose of this paper is to understand the mechanisms occurring during the ultrasonication of the copolymer poly(vinylidenedifluoride-trifluoroethylene). In these experimental conditions, the polymer adopts a core–shell structure and its hydrodynamic diameter is measured by dynamic light scattering. The results show that, without covalent bonds breakage, the hydrodynamic diameter decreases with ultrasonication time and a smaller size population appears. This evolution is reversible in a matter of days. A new two-step mechanism is proposed to describe this phenomenon: first the erosion of a core–shell structure and second the contraction of the core. Beyond shedding a new light on the phenomena occurring during the sonication of polymers used in nanocomposites elaboration, this work also strongly questions the traditional techniques used to study the degradation of polymers, which use the hydrodynamic diameter measurement to determine the molecular weight.     

A novel demonstration of photoacoustic Raman spectroscopy with combined stimulated Raman pumping in H2 molecule

We present the experimental demonstration of a novel, efficient, and vibrational selective technique to prepare population in vibrational level v″ = 1 using the stimulated Raman pumping. Photoacoustic Raman signal has been studied in non-radiative transitions in the molecule H₂ (v″ = 0) and (v″ = 1). The population fraction in the v″ = 1 level can be estimated by using combined photoacoustic Raman spectroscopy with stimulated Raman pumping for the first time.     

Influence of standoff distance on the structure and properties of carbon coatings deposited by atmospheric plasma jet

Carbon coatings were deposited by atmospheric plasma jet. Influence of the distance between the exit of the plasma gun and a substrate (consequently temperature of the substrate) on properties of the coatings was investigated. The coatings deposited near to the exit of the plasma gun are porous with columnar structure, moderate hardness (∼10 GPa), and the lowest hydrogen (∼7 at.%) concentration. The coatings deposited at the larger standoff distance (>5 mm) have higher hydrogen (≤25 at.%) content and graphite-like structure. Most of the hydrogen in all coatings is bonded to the sp³ carbon (70-60 at.%) and predominantly forms methylene compounds. Decrease of standoff distance yields lower concentration of sp³ CH₃ compounds and relative increase of amount of hydrogenated sp² rings.     

Short-range interaction in three-dimensional quantum mechanics

We show that it is possible to define shape-independent three-dimensional short-range quantum interactions in two-parameter form for non-spherical angular momentum channels through double rescaling of potential strength. Unlike the special case of l=0, where the zero-range limit of the system is renormalizable, the effective ranges diverge for l≠0 channels, and the system becomes trivial at zero-size limit. It is also shown that the two-parameter representation with finite interaction range is useful in analyzing phase shifts and describing resonances with accuracy in non-spherical scatterings.     

A new method for resolving combinatorial ambiguities at hadron colliders

We present a new method for resolving combinatorial ambiguities that arise in multi-particle decay chains at hadron colliders where the assignment of visible particles to the different decay chains has ambiguities. Our method, based on selection cuts favoring high transverse momentum and low invariant mass pairings, is shown to be significantly superior to the more traditional hemisphere method for a large class of decay chains, producing an increase in signal retention of up to a factor of 2. This new method can thus greatly reduce the combinatorial ambiguities of decay chain assignments.