Quadratic Growth Conditions and Uniqueness of Optimal Solution to Lasso

Journal of Optimization Theory and Applications - In the previous paper Bello-Cruz et al. (J Optim Theory Appl 188:378–401, 2021), we showed that the quadratic growth condition plays a key...     

Eliashberg theory for disordered superconductors. II. Tunneling into disordered two-dimensional Pb films

A series ofc-axis oriented YBa₂Cu₃O _x -films with different oxygen content were prepared by laser deposition. The oxygen contentx was determined by X-ray diffraction and by resonant Rutherford-back-scattering (RRBS) measurements. Thec-axis length in these films of YBa₂Cu₃O _x is about 0.5% larger compared to bulk values. We describe transport measurements in magnetic fields up to 7 Tesla between room temperature andT _c in samples with an oxygen content between the orthorhombic-to-tetragonal transition (x6.4) and full oxygenation (x7). The ratio /R _H was investigated with respect to the two-dimensional Luttinger liquid theory and the model of the two-dimensional ionic metal. We report on deviations from the expected quadratic temperature behaviour of /R _H , especially in films with high oxygen content.     

Resonances in low-energy rare-gas atom scattering

Precise values of energies and widths of low-lying resonances in some rare-gas atom systems (Ar-Ar, Ne-Kr, Ne-Xe) are reported.     

Combination of three analytical techniques for speciation of Al in environmental samples

An analytical scheme is proposed which combines three speciation techniques for determination of particular Al species in soil extracts and percolating waters. A cation-exchange fast protein liquid chromatography — inductively coupled plasma atomic emission spectrometry (FPLC-ICP-AES) procedure, a microcolumn chelating ion-exchange chromatography- atomic absorption spectrometry (MCC-ETAAS) technique and the 8-hydroxyquinoline spectrophotometric method (8HQ-spectrophotometry) were employed. The FPLC-ICP-AES procedure offers determination of Al³⁺ (retention time 4.5 min) and Al(OH)²⁺ species (retention time 4.0 min) which are separated from Al(OH)⁺ ₂ (retention time 1.5min). AlF²⁺ coelutes with Al(OH)²⁺ species, while Al(SO₄)⁺, AlF⁺ ₂ and negatively charged Al organic complexes coelute with Al(OH)⁺ ₂ species. The MCC-ETAAS technique enables determination of the sum of positively charged monomeric aqua- and hydroxy-Al species plus sulphate- and fluoro-Al complexes. Employing the 8HQ-spectrophotometry the sum of positively charged monomeric aqua- and hydroxy-Al species plus sulphato- and most of the labile organic Al species are determined. The sensitivities of these selected techniques were adequate for speciation of Al in the samples analyzed. On the basis of the specific selectivity of a particular technique various groups of Al species may be determined. Thus, the comparison of analytical data from complementary procedures provides more comprehensive information on Al species present in soil extracts and percolating waters.     

Enhanced emission and its switching in fluorescent organic nanoparticles

A new class of organic nanoparticles (CN-MBE nanoparticles) with a mean diameter of ca. 30-40 nm, which exhibit a strongly enhanced fluorescence emission, were prepared by a simple reprecipitation method. CN-MBE (1-cyano-trans-1,2-bis-(4'-methylbiphenyl)ethylene) is very weakly fluorescent in solution, but the intensity is increased by almost 700 times in the nanoparticles. Enhanced emission in CN-MBE nanoparticles is attributed to the synergetic effect of intramolecular planarization and J-type aggregate formation (restricted excimer formation) in nanopaticles. On/off fluorescence switching for organic vapor was demonstrated with CN-MBE nanoparticles.     

A solvothermal synthesis and the structure of K4Ag2Sn3S9 x 2KOH

A novel layered K(4)Ag(2)Sn(3)S(9) x 2KOH was synthesized solvothermally. A mixture of ethanol and HSCH(2)CH(SH)CH(2)OH was used for the synthesis. The HSCH(2)CH(SH)CH(2)OH plays an important role and appears to serve as a mineralizer for the solvothermal reaction. A layer comprises Sn(3)S(9)(6)(-) clusters linked by Ag(+) ions and possesses two types of 1D channels in which potassium ions are located. The compound crystallizes in the monoclinic P2(1)/m space group [a = 7.8071(2) A, b = 27.3508(1) A, c = 10.5008(2) A, alpha = 90 degrees, beta = 103.874(1) degrees, gamma = 90 degrees, Z = 4]. Its crystal structure, composition analysis, and IR are presented.     

Studium des gegenseitigen Einflusses der Bindungen in Thiocyanat-Kupfer(II)-Komplexen mit Methyl- und Dimethylpyridinen mittels Infrarotspektroskopie

The infrared spectra of thiocyanato-copper(II) complexes of the type Cu(NCS)₂ L ₂ with all isomeric picolines and lutidines (L) as well as those of the type Cu(NCS)₂ L ₃ withL=3- and 4-picoline, 3,4- and 3,5-lutidine were measured. The behaviour of the (CN) stretching vibrations of the Cu(NCS)₂ L ₂ complexes led to conclusions on the different kind of coordination of the NCS groups in dependence on the ligandL. The mutually conditioned strength of the Cu–NCS and Cu–N(L) bonds in the equatorial plane, especially in the presence of ligandsL with the steric effect, was determined from the frequency shift of the Cu–NCS and Cu–N(L) stretching vibrations with regard to the vibrations for Cu(NCS)₂(pyridine)₂.

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Extraction of americium,lanthanides and some fission product elements by bidentate phosphonates

The extraction of Am, Eu, Ce(III), Zr(IV), and Sr from aqueous nitric acid— nitrate media by dibutyl N,N-diethylcarbamylphosphonate and dibutyl N,N-diethylcar-bamylmethylenephosphonate dissolved in carbon tetrachloride was studied. The trivalent actinide and lanthanide elements may be separated in certain aqueous phase acidity regions from Fe(III), Zr(IV), and Sr, whereas the separation of actinide elements from the lanthanide elements is poor. The extractant to metal ratio in the extracted complexes of Am, Eu, and Ce(III) is 3. The interferences in the extraction due to acidic impurities in the extracting agent are discussed.