CALCULATION OF THE FUNDAMENTAL SOLUTION FOR THE THEORY OF SHALLOW SHELLS CONSIDERING SHEAR DEFORMATION

In this paper, some formulas are derived for the numerical computation of the fundamental solution obtained in ref [1] and relevant computer methods are also discussed in detail. As an application of the fundamental solution, problems of a concentrated normal force acting on infinite shallow shells having positive, zero and negative Gaussian curvatures are calculated according to the numerical methods given in the paper.     

Characterization of PolyA and PolyC mismatches by Raman spectroscopy

A.C mismatches are studied by Raman spectral characterization of PolyA, PolyC, and their equimolar complex in solution of 0.14 mol/L Na ,pH7.0.Experimental results show that A·C mismatches occur to be A/B (mainly A) conformers, and unlike Watson-Crick base pairing, this kind of mismatches is stabilized by only one hydrogen bond involving cytosine N4H2 and adenine N7.The formation of A·C complex makes the base stacking interactions much stronger, and conformation of the backbone more ordered, which leads to obvious Raman hypochromic effect with some shifts in corresponding bands.     

Enhanced electron screening in d (d, p)t for deuterated Ta*

The recent observation of a large electron screening effect in the d(d, p)t reaction using a deuterated Ta target has been confirmed using somewhat different experimental approaches: U _e = 309±12 eV for the electron screening potential energy. The high U _e value arises from the environment of the deuterons in the Ta matrix, but a quantitative explanation is missing. Received: 21 December 2001 / Accepted: 29 January 2002     

Open path atmospheric spectroscopy using room temperature operated pulsed quantum cascade laser

We report the application of a distributed feedback quantum cascade laser for 5.8 km long open path spectroscopic monitoring of ozone, water vapor and CO(2). The thermal chirp during a 140 or 200 ns long excitation pulse is used for fast wavelength scanning. The fast wavelength scanning has the advantage of the measured spectra not being affected by atmospheric turbulence, which is essential for long open path measurements. An almost linear tuning of about 0.6 and 1.2 cm(-1) is achieved, respectively. Lines from the nu(3) vibrational band of the ozone spectra centered at 1,031 and 1,049 cm(-1) is used for ozone detection by differential absorption. The lowest column densities (LCD) for ozone of the order of 0.3 ppmm retrieved from the absorption spectra for averaging times less than 20s are better then the LCD value of 2 ppmm measured with UV DOAS systems. The intrinsic haze immunity of mid-IR laser sources is an additional important advantage of mid-IR open path spectroscopy, compared with standard UV-vis DOAS. The third major advantage of the method is the possibility to measure more inorganic and organic atmospheric species compared to the UV-vis DOAS.     

Sobolev and strict continuity of general hysteresis operators

The most natural and important topologies connected with hysteresis operators are those induced by uniform convergence, W^{1, 1}‐convergence, and strict convergence. Indeed the supremum norm and the variation are invariant under reparameterization. We prove a general result that implies that if a hysteresis operator is continuous with respect to the topology of W^{1, 1}, then it is continuous with respect to the strict topology. Copyright © 2009 John Wiley & Sons, Ltd.     

Proton-proton scattering without Coulomb force renormalization

We demonstrate numerically that proton-proton (pp scattering observables can be determined directly by standard short-range methods using a screened pp Coulomb force without renormalization. In the examples the appropriate screening radii are given. We also numerically investigate solutions of the 3-dimensional Lippmann-Schwinger (LS) equation for a screened Coulomb potential alone in the limit of large screening radii and confirm analytically predicted properties for off-shell, half-shell and on-shell Coulomb t -matrices. These 3-dimensional solutions will form a basis for a novel approach to include the pp Coulomb interaction into the 3N Faddeev framework.     

Effect of projectile structure in incomplete fusion in <Superscript>24</Superscript>Mg + <Superscript>59</Superscript>Co reaction

Integrated cross-section data for proton-proton bremsstrahlung including the points with the phase-space singularity, which occurs close to the maximum non-coplanarity angle, are presented. A numerical integration of theoretical cross-sections is performed over the non-coplanarity angle to integrate out this singularity. Furthermore, a comparison is made between measured cross-sections and predictions of two soft-photon models. All features observed for the data far from the singularity, including the overestimation of the cross-section by 30% by the theoretical calculations, emerge as well for the data close to and including the singularity.     

Neutron excess nuclei of hydrogen and helium at ACCULINNA

Attempt to observe a ⁷H resonance produced in the reaction ²H(⁸He,³He)⁷H resulted only in setting a limit dσ/dΩ≤ 20 μb/sr for the reaction exit channel which could populate a resonance lying between 0 and 3 MeV above the ⁷H decay threshold. The quasi-free scattering of the α core bound in ⁶He was explored keeping in mind the possible study of the cluster structure of this halo nucleus. For the first time coincident particles emitted in the ⁴He(⁶He, 2α)nn reaction were detected in wide angular ranges giving a wide kinematical range of the measured angular and momentum distributions. The contribution of processes, competing with QFS in the α+ α+n+n output channel, was considerably suppressed by the selection of events with E_α1(2)-nn>10 MeV. A number of experimental distributions, relevant to the reaction mechanism and to the ⁶He structure, were compared with the results of MC simulations based on the PWIA formalism. The PWIA predictions showed consistency with the experimental data.     

pp → ppπnear threshold in pionless effective theory

The total cross-section of the pp → ppπ⁰ reaction near threshold is calculated in pionless effective field theory with a di-baryon and external pions. The amplitudes for a leading one-body and subleading contact neutral pion production vertex are obtained including the initial- and final-state interactions. After estimating a low-energy constant in the contact vertex, we compare our results for the total cross-section with the experimental data.