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1.
V. V. Kokorin V. A. Chernenko J. Pons C. Segui E. Cesari 《Physics of the Solid State》1997,39(3):485-487
Anomalies have been detected in the temperature behavior of the physical properties of Ni2MnGa in the temperature interval preceding the martensitic transformation, which is attributed to TA
2 phonon mode condensation at T=T
I>T
m (T
m is the martensitic transition temperature).
Fiz. Tverd. Tela (St. Petersburg) 39, 557–559 (March 1997) 相似文献
2.
This paper describes how to obtain an analytic approximation to the transfer function of a conduction calorimeter, namely a procedure to identify the calorimetric system. In this case modulating functions are used directly on the thermogram. The method is used twice: to obtain the time constants and the amplitudes. Its feasibility is tested on two models which span the frequency range usually attained by actual calorimeters. The influence of random noise and baseline drift have also been analyzed. The results show that three or four time constants are correctly obtained. 相似文献
3.
G. Del Piero G. Perego S. Cucinella M. Cesari A. Mazzei 《Journal of organometallic chemistry》1977,136(1):13-18
The crystall and molecular structures of (ClAlN-i-Pr)6 (I), and of (Me0.83H0.17AlN-i-Pr)6(MeAlN-i-Pr)6 have been determined by single crystal three-dimensional X-ray analysis. Block-matrix least-squares refinements led to conventional R factor of 0.039 for I and 0.037 for II. The compounds are isostructural, as the cage molecules consist of a prismatic hexagonal framework, (AlN)6, similar to that observed for the parent hydrogenated analogue (HAlN-i-Pr)6.Some differences in bond distances and angles are discussed, in connection with the different Al-bonded substituents. Crystal data: I, trigonal space group R; a = 17.083(2), c = 9.652(1); Z = 3; Dc 1.46 g cm?3; II, trigonal space group R, a = 17.378(3), c = 9.706(3) »; Z = 3; Dc 1.15 g cm?3. 相似文献
4.
G. Perego G. Del Piero M. Cesari A. Zazzetta G. Dozzi 《Journal of organometallic chemistry》1975,87(1):53-60
The compound [(HAlN-i-Pr)2(H2AlNH-i-Pr)3] has been prepared and the crystal and molecular structure determined by an X-ray analysis, carried out with three-dimensional data collected on a diffractometer. The molecule is made up of a cyclohexane-type ring, [(HAlN-i-Pr)2(H2AlNH-i-Pr)], in skewboat conformation, on each side of which is bonded an -H2AlNH-i-Pr- bridging unit between a nitrogen atom and an aluminum atom of the ring. The molecule lies on a binary axis of the crystal, but this symmetry is fulfilled only by a statistical orientation of the asymmetric molecular units (the statistical model is not however completely defined). The AlN bond lengths range from 1.901 to 1.985 Å; the average NC bond length is 1.527(9) Å. Main crystal data are: monoclinic space group C2/c; a = 10.15(2), b = 21.64(3), c = 12.84(2) Å, β = 111.9(5)°; Z = 4; calculated density 1.095 g/cm3. The structure was solved by direct methods and block-matrix least-squares converged to an R value of 5.6%. 相似文献
5.
G. Perego M. Cesari G. Del Piero A. Balducci E. Cernia 《Journal of organometallic chemistry》1975,87(1):33-41
The crystal and molecular structure of the adduct (HAlN-i-Pr)6AlH3 has been determined from single-crystal and three dimensional X-ray diffraction data collected by counter methods. The cage-type molecular structure consists of two six-membered rings, (AlN)3, joined together by four adjacent transverse AlN bonds; the loss of two of these bonds allows the complexation of one alane molecule, with five-coordination of the aluminum (trigonal bipyramidal geometry), through two AlN bonds and two AlHAl bridge bonds. The AlN bond lengths range from 1.873 to 1.959 Å; the average AlH bond length is 1.50(1) Å for the four-coordinated aluminum atoms; the average distance of the two apical hydrogens from the five-coordinated aluminum atom is 1.92(5) Å. Colourless prismatic crystals of the compound have the following crystal data: triclinic space group P; a = 17.13(2); b = 10.78(2); c = 10.20(2) Å; α = 124.3(4), β = 92.0(4), γ = 92.1(5); Z = 2; calculated density 1.157 g/cm3. The structure has been refined by block-matrix, least-squares methods using 4358 independent reflections to a standard unweighted R factor of 4.9%. 相似文献
6.
G. Del Piero M. Cesari S. Cucinella A. Mazzei 《Journal of organometallic chemistry》1977,137(3):265-274
The compounds [((THF)Mg)(HA1N-t-Bu)3] (I) and [((THF)3Ca)(HA1N-t-Bu)3] · THF (II) have been structurally characterized from single-crystal diffraction data. The molecular structures are based on an (A1N)4 “cubane” type framework in which an aluminum is replaced by an alkaline earth metal. According to the size and the coordination of the “foreign” atom (four for Mg, six for Ca) the cubic geometry of the cage is increasingly distorted. Coordination is completed by one molecule of THF to the Mg atom and three molecules to the Ca atom; in II a molecule of THF crystallizes with a cage molecule. Mean MgN and CaN bond distances are 2.090(4) and 2.490(2) Å. Crystal data: I, orthorombic, space group Pbca, a 17.107(2), b 17.305(4) and c 20.220(5) Å, Z = 8, calculated density 1.031 g/cm3; II, orthorombic, space group Pbca, a 20.48(1), b 20.38(1), c 20.51(1), Z = 8, calculated density 1.081 g/cm3. 相似文献
7.
Cristiana Cesari Iacopo Ciabatti Cristina Femoni Maria Carmela Iapalucci Stefano Zacchini 《Journal of Cluster Science》2017,28(4):1963-1979
The reactions of [Ni16(C2)2(CO)23]4? and [Ni38C6(CO)42]6? with CuCl afforded mixtures of the previously reported [HNi42C8(CO)44(CuCl)]7? bimetallic octa-carbide cluster and the new [HNi43C8(CO)45]7? and [HNi44C8(CO)46]7? homo-metallic octa-carbides. The three species have very similar properties resulting always in co-crystals such as [NMe4]7[HNi42+2xC8(CO)44+2x(CuCl)1?x]·6.5MeCN (x = 0.14) (86% [HNi42C8(CO)44(CuCl)]7?, 14%[HNi43C8(CO)45]7?/[HNi44C8(CO)46]7?) and [NMe4]7[HNi42+2xC8(CO)44+2x(CuCl)1?x]·5.5MeCN (x = 0.30) (70% [HNi42C8(CO)44(CuCl)]7?, 30% [HNi43C8(CO)45]7?/[HNi44C8(CO)46]7?). The new homo-metallic octa-carbides can be obtained free from the Ni–Cu octa-carbido cluster by reacting [Ni10(C2)(CO)16]2? in thf with a stoichiometric amount of CuCl, and crystals of [NMe4]6[H2Ni43+xC8(CO)45+x]·6MeCN (x = 0.72), which contain [H2Ni44C8(CO)46]6? (72%) and [H2Ni43C8(CO)45]6? (28%), have been obtained. Despite the different charges and compositions, these anions display almost identical structures, which are also closely related to those previously reported for the bimetallic Ni–Cd octa-carbido clusters [Ni42+xC8(CO)44+x(CdCl)]7? and [HNi42+xC8(CO)44+x(CdBr)]6?. Indeed, all these clusters are based on the same Ni42C8 cage decorated by miscellaneous [CdX]+ (X = Cl, Br), [CuCl] and [Ni(CO)] fragments. 相似文献
8.
9.
Crocetti Letizia Floresta Giuseppe Nazir Shabnam Vergelli Claudia Bhogal Amrit Biancalani Claudio Cesari Nicoletta Giovannoni Maria Paola Cilibrizzi Agostino 《Structural chemistry》2022,33(3):769-793
Structural Chemistry - We report here synthetic approaches to access new classes of small molecules based on three heterocyclic scaffolds, i.e. 3,7-dihydropyrimido[4,5-d]pyridazine-4,8-dione,... 相似文献
10.
Zhihui Yi Luca Giacomo Bettini Gaia Tomasello Prajwal Kumar Paolo Piseri Irina Valitova Paolo Milani Francesca Soavi Fabio Cicoira 《Journal of Polymer Science.Polymer Physics》2017,55(1):96-103
Planar organic electrochemical transistors (OECTs) using PEDOT:PSS as the channel material and nanostructured carbon (nsC) as the gate electrode material and poly(sodium 4‐styrenesulfonate (PSSNa) gel as the electrolyte were fabricated on flexible polyethylene terephthalate (Mylar®) substrates. The nsC was deposited at room‐temperature by supersonic cluster beam deposition (SCBD). Interestingly, the OECT acts as a hybrid supercapacitor (to give a device that we indicate as transcap). The energy storage ability of transcaps has been studied with two cell configurations: one featuring PEDOT:PSS as the positive electrode and nsC as the negative electrode and another configuration with reversed electrode polarity. Potentiostatic charge/discharge studies show that both supercapacitors show good performance in terms of voltage retention, in particular, when PEDOT:PSS is used as the positive electrode. Galvanostatic charge–discharge characteristics show typical symmetric triangular shape, indicating a nearly ideal capacitive behavior with a high columbic efficiency (close to 100%). © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 96–103 相似文献