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41.
Daniel Lüert Dr. Christina M. Legendre Dr. Regine Herbst-Irmer Prof. Dr. Dietmar Stalke 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(15):e202104470
Based on the potassium [{S(tBuN)2(tBuNH)}2K3(tmeda)-K3{(HNtBu)(NtBu)2S}2] ( 1 ) and sodium precursors [S(tBuN)3(thf)3-Na3SNa3(thf)3(NtBu)3S] ( 2 ), [S(tBuN)3(thf)3Na3{(HNtBu)(NtBu)2S}] ( 3 ) and [(tmeda)3S-{Na3(NtBu)3S}2] ( 4 ) the syntheses and magnetic properties of three mixed metal triimidosulfite based alkali-lanthanide-metal-cages [(tBuNH)Dy{K(0.5tmeda)}2{(NtBu)3S}2]n ( 5 ) and [ClLn{Na(thf)}2{(NtBu)3S}2] with Ln=Dy ( 6 ), Er ( 7 ) are reported. The corresponding potassium ( 1 ) and sodium ( 2 – 4 ) based cages are characterized through XRD and NMR experiments. Preventing lithium chloride co-complexation led to a significant increase of SMM performance to previously reported sulfur-nitrogen ligands. The subsequent DyIII-complexes 5 and 6 display slow relaxation of magnetization at zero field, with relaxation barriers U=77.0 cm−1 for 5 , 512.9 and 316.3 cm−1 for 6 , respectively. Significantly, the latter complex 6 also exhibits a butterfly-shaped hysteresis up to 7 K. 相似文献
42.
Sarah V.A.-M. Legendre Martyn Jevric Julian Klepp Christopher J. Sumby Ben W. Greatrex 《Tetrahedron》2018,74(12):1229-1239
A Kornblum-DeLaMare/aza-Michael reaction of 3,6-dihydro-1,2-dioxines with primary and secondary amines has been developed which affords 4-hydroxy-3-aminoketones. The aza-Michael products were reduced using non-selective NaBH4/MeOH or diastereoselective (up to 92:8) SnCl4/NaBH4 conditions yielding (1R1,3S1)-3-amino-1,4-diols in up to 97% and 70% yield respectively. The major reduction product was converted in two steps to (±)-HPA-12, which is an inhibitor of the cytosolic ceramide transporting protein. 相似文献
43.
44.
The collision between a contaminated spherical bubble and fine particles in suspension is considered for rp/rb ? 1 (rp being the radius of the particles in suspension and rb the radius of the bubble). The collision probability or efficiency is defined as the number of particles colliding the bubble surface to the number of particles initially present in the volume swept out by the bubble. In this note we show that the collision probability can be expressed as Pc(rp/rb,Re) = g(rp/rb)f(Re) for both mobile and immobile interfaces. For partially contaminated bubbles a linear or quadratic dependency in rp/rb is found depending on the level of contamination and the value of rp/rb. These behaviors are given by the flux of particles near the surface which is controlled by the tangential velocity for mobile interfaces and by the velocity gradient for immobile interfaces. The threshold value (rp/rb)th between the rp/rb and (rp/rb)2 evolution is shown to vary as sinn(Re)(θclean/n(Re))sin(3θclean/4), θclean being the angle describing the front clean part of the bubble and n(Re) varying from n = 2 to n = 1 from small to large Reynolds number. 相似文献
45.
Piotr Szterner Bernard Legendre Mehrez Sghaier 《Journal of Thermal Analysis and Calorimetry》2010,99(1):325-335
The physicochemical properties of theophylline hydrate and anhydrous polymorphic forms I and II were evaluated using crystallographic
and calorimetric method. This study has been carried out with the following techniques: differential scanning calorimetry
(DSC), thermogravimetric analysis (TG) and X-ray diffractometry. The X-ray patterns on powder for investigated compounds are
presented. 相似文献
46.
In this paper we study the smallest non-zero eigenvalue \(\lambda _1\) of the Laplacian on toric Kähler manifolds. We find an explicit upper bound for \(\lambda _1\) in terms of moment polytope data. We show that this bound can only be attained for \(\mathbb C\mathbb P^n\) endowed with the Fubini–Study metric and therefore \(\mathbb C\mathbb P^n\) endowed with the Fubini–Study metric is spectrally determined among all toric Kähler metrics. We also study the equivariant counterpart of \(\lambda _1\) which we denote by \(\lambda _1^T\). It is the smallest non-zero eigenvalue of the Laplacian restricted to torus-invariant functions. We prove that \(\lambda _1^T\) is not bounded among toric Kähler metrics thus generalizing a result of Abreu–Freitas on \(S^2\). In particular, \(\lambda _1^T\) and \(\lambda _1\) do not coincide in general. 相似文献
47.
The aim of the action of COST 531 taking into account the eleven elements Ag,Au,Bi,Cu,In,Pb,Sb,Sn,Zr (solder), Ni and Pd (substrate) is the database assessment for candidates of lead free soldering process. We studied four of them forming the ternary systems Ag-Au-Bi and Ag-Au-Sb. First we determined experimentally their phase diagrams, then the integral enthalpy of mixing of the liquid phase along different sections at different temperatures by using a SETARAM device heat flow calorimeter of Tian-Calvet type. All these data were used to optimize the thermodynamic parameters of the different phases of both ternary systems. 相似文献
48.
Several situations in which a spherical bubble experiences a lift force are examined, especially through the use of computational results obtained by solving the full Navier–Stokes equations. The lift force is computed over a wide range of Reynolds number for the case of pure shear flow, pure strain and solid body rotation. Using these results, the validity of asymptotic solutions derived in the limit of low Reynolds number or inviscid flow is discussed. A general expression of the lift force valid for low to moderate shears is proposed. It is shown that for such shears, the lift force in a complex flow can be predicted by superposing the results obtained in pure strain flow and solid body rotation flow. Finally, the interaction force experienced by two bubbles rising side-by-side is studied. The computational results reveal that, at variance with the predictions of potential theory, the sign of this force changes when the Reynolds number or the separation distance between the bubbles decreases below a critical value. All these results are discussed in terms of vorticity. The respective role played by the vorticity generated at the bubble surface and by the one that is eventually present in the unperturbed flow is emphasized. 相似文献
49.
R. Legendre K. A. Kobe und H. Drehschmidt 《Fresenius' Journal of Analytical Chemistry》1933,93(5-6):200-202
Ohne Zusammenfassung 相似文献
50.