Gas chromatography-mass spectrometry characterization of the varnish and glue of an ancient 18th century double bass

A GC-MS investigation is conducted on the double bass "Panormus", property of Conservatorio di Musica "Vincenzo Bellini" in Palermo. The most important components of the varnish (fatty acids) and of the glue (proteinaceous amino acids), with which the musical instrument was treated in the past, are determined. The analyses are carried out by prior derivatization of fatty acids by acidic methanol and of amino acids by acidic methanol and trifluoroacetic anhydride (TFAA). Analytes identification is achieved by direct comparison with several reference materials and the use of a digitized library.     

The Quasiregular Model and the Phase Equilibrium Diagram with a Minimum Point for a Binary System

Using the quasiregular model, some characteristics of the phase diagram with a minimum point were studied for a binary system. We obtained the inequalities which must be satisfied by these parametera W_S,W_L,V_S and V_L in various models.     

Multiple ionization of argon in coincidence with projectile ions in 60–120 MeV Si q+-Ar collisions

A projectile ion-recoil ion coincidence technique has been employed to study the multiple ionization and the charge transfer processes in collisions of 60–120 MeV Si ^q+ (q = 4−14) ions with neutral argon atoms. The relative contribution of different ionization channels, namely; direct ionization, electron capture and electron loss leading to the production of slow moving multiply charged argon recoil ions have been investigated. The data reported on the present collision system result from a direct measurement in the considered impact energy for the first time. The total ionization cross-sections for the recoil ions are shown to scale as q ^1.7/E _p ^0.5 , where E _p is the energy in MeV of the projectile and q its charge state. The recoil fractions for the cases of total- and direct ionizations are found to decrease with increasing recoil charge state j. The total ionization fractions of the recoils are seen to depend on q and to show the presence of a ‘shell-effect’ of the target. Further, the fractions are found to vary as 1/j ² upto j = 8+. The average recoil charge state 〈j〉 increases slowly with q and with the number of lost or captured electrons from or into the projectile respectively. The projectile charge changing cross-sections σ _qq′ are found to decrease with increasing q for loss ionization and to increase with q for direct-and capture ionization processes respectively. The physics behind various scaling rules that are found to follow our data for different ionization processes is reviewed and discussed.     

Transfer measurements for the Ti+Ni systems at near barrier energies

Large enhancements have been observed in the sub-barrier fusion cross sections for Ti+Ni systems in our previous studies. Coupled channel calculations incorporating couplings to 2⁺ and 3⁻ states failed to explain these enhancements completely. A possibilty of transfer channels contributing to the residual enhancements had been suggested. In order to investigate the role of relevant transfer channels, measurements of one- and two-nucleon transfer were carried out for ^46,48Ti+⁶¹Ni systems. The present paper gives the results of these studies.     

Structural,optical, and electrical properties of Cu2SnS3 thin films produced by sol gel method

Physics of the Solid State - The structural, optical, and electrical properties of p-type Cu2SnS3 thin films produced by the deposition of a dimethylsulfoxide-based sol gel solution using the...     

Water-soluble porphyrin detection in a pure-silica photonic crystal fiber

Aqueous solutions of the water-soluble porphyrin 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrinatomanganese(III) acetate were inserted into the holes of a photonic crystal fiber, and the porphyrin absorption bands were identified. Results were obtained for three concentrations. The porphyrins in water show no surface interactions with the silica walls of the capillary channels. We discuss the implications for future hybrid electronic and photonic fiber devices.     

一维热传导方程热源反问题基于最小二乘法的正则化方法

研究一维热传导方程热源反问题.给出基于最小二乘支持向量机（LS-SVM）求解的半解析表达式,此外还给出一种参数调节方法以及算法稳定性的证明.数值实验表明该方法具有较高的数值精度和稳定性.     

Heterocyclic photorearrangements. Photochemical behaviour of some 3,5-disubstituted 1,2,4-oxadiazoles in methanol at 254 nm

Photochemical behaviour of some 3,5-disubstituted 1,2,4-oxadiazoles in methanol at 254 nm has been investigated. Ring photoisomerization to the 1,3,4-oxadiazole heterocycle or formation of open chain compounds involving the nucleophilic solvent was shown to depend on the nature and the position of the substituent. Photoinduced ring closure into the benzimidazole system, involving a 3-N-phenylamino side chain sequence and a photolytic intermediate of the oxadiazole heterocycle, is also reported.     

Conformations of laulimalide in DMSO-d6

Laulimalide is one of the newest naturally occurring macrolides known to act as a microtubule stabilizing agent with properties similar to Taxol. It also stands as being one of the most flexible with 18 rotatable bonds. This large number of rotatable bonds allows for approximately 3(18) potential conformers. To examine the conformational energy surface of laulimalide, we have performed an NAMFIS deconvolution analysis for laulimalide in DMSO-d6. The latter has been supplemented with a post-NAMFIS energy analysis at the Becke3LYP/6-31G level that examines the opposing effects of internal hydrogen bonding and syn-pentane interactions. In this way, we have identified 15 laulimalide conformations that can be classified into 5 different families: Supine, Convex, Cobra, Stretch, and Concave motifs.