3'(,3")-(二)甲酰基(二)苯并冠醚的2D NMR研究

测定了3'(,3")-(二)甲酰基(二)苯并冠醚(1~7)的¹H、¹³C谱,首次结合¹H-¹H COSY、¹³C-¹H COSY、COLOC二维谱对这些化合物的¹H、¹³C化学位移进行了归属。用NOESY谱确定了合成产物冠4、冠5的结构,并对溶液中的构象异构体及其溶剂影响进行了初探。作者以冠1~8的¹H、¹³C谱的归属为参照,提出了正确归属冠醚醚环上次甲基¹H、¹³C化学位移的一般规则。     

Advances in melt-processed HTS applications at politecnico di torino

Summary This paper deals with a comparison of chemical, physical and mechanical characterisation of YBCO samples obtained with Temporary-Liquid-Densification Melt Growth (TLDMG). Ba₂YCu₃O_7-x +50% excess BaY₂CuO₅ pellets were prepared from different Ba-Y-Cu-O system phases, suitable to produce during the heat treatment temporary liquids at temperatures lower than 1000°C. A mechanical characterisation was performed in zero-field-cooling and field-cooling condition, showing hysteretic behaviour and creep of the levitation force. Measurements of magnetic hysteresis cycles in low fields and a.c. susceptibility were also performed. Some mechanical applications (high-speed electric motor and flywheel energy accumulator) were built and tested. The work now proceeds on two new industrial applications of melt-processed HTSC materials. Paper presented at the “VII Congresso SATT? Torino, 4–7 October 1994.     

Spectral analysis and trend of total ozone observations at Vigna di Valle

Summary Time series analyses of measurements of total ozone make possible an in-depth climatological study of this important stratospheric gas. The Italian Air Force's Vigna di Valle Observatory (42°N, 12°E, 262 m a.s.l.) provided a time series of monthly averages (January 1958–December 1988) of total ozone. Spectral analysis and running averages were combined to detect medium-(QBOs of estimated (4÷5) DU amplitudes) and long-term fluctuations (possible correlation to 11-year solar cycle) and to filter them, leaving any overlapping trends unaltered. Total ozone trend estimates produced by the present study were +0.1% per decade for the 1959–1987 period and a decrease of −0.4% per decade for the more recent 1970–1987 span, over which a pronounced ozone depletion caused mainly by CFCs is assumed. This study has supported by the CNR-ENEL Project ?Interaction of energy system with human health and environment?.     

Self-organisation of di(perfluorohexyl)hexane in Langmuir and LB films

Symmetrical triblock semifluorinated n-alkane, di(perfluorohexyl)hexane of the formula F(CF₂)₆(CH₂)₆(CF₂)₆F (abbreviated F₆H₆F₆), has been synthesised and investigated at the air/water interface. Our results show for the first time that this unusual film-forming material, completely hydrophobic in nature and possessing no polar group, is capable of stable film formation at the free water surface. The surface pressure–area isotherm of the studied compound exhibited two regions: corresponding to monotonous pressure rise, followed by a pseudo-plateau region. Visualisation of film structure with Brewster angle microscope (BAM) proved the formation of domains within the pseudo-plateau region. A closer insight into the structure of these domains with atomic force microscope (AFM) proved their ordered, circular shape. The average area of F₆H₆F₆ domain was found to depend on surface pressure value, as it is 4.98 ± 1.75 μm² at π = 1.2 mN/m to 16.54 ± 0.31 μm² at π = 1.7 mN/m. Following performed quantum-chemical calculations, it can be concluded that the observed surface aggregates from F₆H₆F₆ are formed by linear conformers with shifted CF and CH parts. The calculated domain thickness is between 20 and 21 Å, which perfectly agrees with the experimental value estimated from AFM measurements (20.3 ± 1.4 Å).     

Mechanism of manganese (mono and di) telluride thin-film formation and properties

Mechanistic studies on the electrocrystallization of manganese telluride (MnTe) thin film are reported using aqueous acidic solution containing MnSO₄ and TeO₂. Tartaric acid was used for the inhibition of hydrated manganese oxide anodic growth at counter electrode. A detailed study on the mechanistic aspect of electrochemical growth of MnTe using cyclic voltametry is carried out. Conditions for electrochemical growth of manganese mono and di telluride thin films have been reported using cyclic voltammetric scans for Mn²⁺, Te⁴⁺ and combined Mn²⁺ and Te⁴⁺. X-ray diffraction showed the formation of polycrystalline MnTe films with cubic, hexagonal and orthorhombic mixed phases. MnTe film morphology was studied using scanning electron microscope. Susceptibility and electrical characterization supports the anti-ferromagnetic behavior of the as-deposited MnTe thin film.     

Photoluminescent properties of di(8-hydroxyquinolato) zinc impregnated in nanoporous glass

Photoluminescent properties of a metal-organic complex, di(8-hydroxyquinolato) zinc, impregnated in nanoporous glass were investigated. In comparison with those in the normal organic fluorescent material,the emission band of the impregnated organic phosphor became wider. Blueshift (14 nm) was observed due to π* → n emission transition. The excitation band of the embedded organic phosphor had a larger blueshift and was divided into several sub-bands. The intensity in the short wavelength end of the embedded organic fluorescent material became much stronger.     

Krichever Maps,Faà di Bruno Polynomials,and Cohomology in KP Theory

We study the geometrical meaning of the Faà di Bruno polynomials in the context of KP theory. They provide a basis in a subspace W of the universal Grassmannian associated to the KP hierarchy. When W comes from geometrical data via the Krichever map, the Faà di Bruno recursion relation turns out to be the cocycle condition for (the Welters hypercohomology group describing) the deformations of the dynamical line bundle on the spectral curve together with the meromorphic sections which give rise to the Krichever map. Starting from this, one sees that the whole KP hierarchy has a similar cohomological meaning.     

The contribution of IFSI (Istituto di Fisica dello Spazio Interplanetario) to the ISO Project

Summary We describe the participation of the “Istituto di Fisica dello Spazio Interplanetario? in the Infrared Space Observatory (ISO) Project. We comtribute to the international consortium of Institutes to build the Long Wavelength Spectrometer (LWS): in particular we have responsability for the construction of the data processing unit,i.e. the on-board computer. To speed up publication, the proofs were not sent to the authors and were supervised by the Scientific Committee.