Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Three high-level correlated ab initio studies have recently been performed on the electronic absorption spectrum of free base porphin (FBP), but significant differences between the various assignments of the low-lying bands remain. In view of the importance of FBP as the basic building block of the porphyrins, further…
Atmospheric pressure glow plasma was used to modify the inner surface of a commercially available poly(vinyl chloride) (PVC) tube sample to enhance the biocompatible properties by polymerizing tetrafluoroethylene (TFE). The composition and properties of the modified surface were similar to those of PTFE. X-ray photoel…
The preparation and coating of nickel on amorphous and crystallized alumina were carried out by employing a sonochemical method. The interaction between the nickel as well as its oxide and the alumina core was then studied by TEM, XRD, DSC, DRS, FTIR, and magnetization measurements. The following were found: (1) Amorp…
Strongly distorted RNiO 3 (R = Gd, Dy) perovskites, containing Ni 3+, have been prepared under high-pressure conditions: 90 MPa of O 2 pressure (R = Gd) or 2 GPa of hydrostatic pressure in the presence of KClO 4 (R = Dy). These materials have been characterized by X-ray diffraction, neutron powder diffraction (NPD) (f…
Room-temperature single-crystal X-ray structure determinations are recorded for a number of adducts of hydrated lanthanoid(III) chlorides with 2,2'-bipyridine, ‘bpy’, crystallized from water/ethanol solutions, which contain mononuclear arrays with 1 : 1 Ln/bpy stoichiometry. Extended isomorphous series have been defin…
Room-temperature single-crystal X-ray structure determinations are recorded for (hydrated) lanthanoid(III) nitrate/2,2':6',2"-terpyridine (‘tpy’) (1 : 1) complexes; all are of the form Ln(NO3)3/tpy/H2O(1 : 1 : x ), [(tpy)Ln(O2NO)2(OH2)y](NO3)(. z H2O), and form two series of compounds. For Ln = La(-)Gd, the complexes…
Room-temperature single-crystal X-ray structural characterizations are recorded for hydrated lan- thanoid(III) bromide/2,2':6',2"-terpyridine (tpy) (1 : 1) complexes, showing all to be ionic and of the form [(tpy)Ln(OH2) x ]Br3. y H2O, where x and y are 6 and 1 for the isomorphous series Ln = La(-)Er (and intermediate…
Room-temperature single-crystal X-ray structure determinations carried out on rare earth bromides crystallized from water at room temperature define three series of hydrates LnBr3.nH2O. For Ln = La, Ce, a heptahydrate phase ( n = 7) is defined, triclinic P 1, a ˜ 8·6, b ˜ 9·4, c ˜ 8·3 Å, a ˜ 108, ß ˜ 99, ? ˜ 72°, isom…
Extension/augmentation of preexisting work carried out in respect of room-temperature single-crystal X-ray structural characterization of trivalent rare earth acetates, crystallized as ‘maximal’ hydrates, Ln(ac)3. x H2O, from aqueous solution under local ambience, suggests the following array to be prevalent: For Ln =…
Room-temperature single-crystal X-ray structure determinations carried out on ‘maximally’ hydrated rare earth(III) trifluoroacetates, Ln(tfa)3. x H2O, crystallized at room temperature, show the Ln = La, Ce adducts to be isomorphous and monoclinic, P 21/ c , a ˜ 11·9, b ˜ 12·8, c ˜ 9·8 8 Å, ß ˜ 103·7°, Z = 4; they are…
Room-temperature single-crystal X-ray structure determinations are known for a number of ‘maximally hydrated" nitrates of, in particular, the lighter lanthanoid elements; in all cases, all nitrates coordinate as O , O '-bidentate ligands so that the series may be represented at the outset as Ln(O2NO)3. x H2O. Two dist…
The spreading behavior of microdrops of surfactant solutions at solid surfaces has been studied. The influence on the spreading of different factors, such as the drop lifetime prior to surface contact, surface tension dynamics, surface energy, and surfactant properties, was systematically investigated. The results obt…
Room-temperature single-crystal X-ray structure determinations of the 1 : 3 adducts of the trivalent lanthanoid perchlorates with 2,2':6',2"-terpyridine (‘tpy’) as crystallized from acetonitrile are recorded. The Ln = La complex is the only one of its structural type, being modelled as La(ClO4)3/tpy/MeCN/H2O (1 : 3 :…
Understanding the properties of complex systems requires the analysis of their energy landscape. Using simple models for the crystalline compounds MgF 2 and CaF 2 as example landscapes, we show that, in addition to the construction of tree-graph approximations of the landscape, the threshold algorithm can be employed…
The effect of sodium dodecyl benzenesulfonate (SDBS) surfactant micelles on the Ostwald ripening was investigated by several experiments and by computer simulation. The experimental ripening rates determined by dynamic light scattering were about 2 times higher than the one predicted by the Lifshitz−Slyozov−Wagner (LS…
Room-temperature single-crystal X-ray studies carried out on trivalent rare earth sulfate hydrates, Ln2(SO4)3. x H2O, crystallized at local ambience suggest the following arrays to be prevalent. For Ln = La, the nonahydrate is found, hexagonal P 63/ m , with conventional R on | F | 0·023 for N o 1159 ‘observed’ ( I &a…
Neutron powder diffraction has been used to examine the structural phase transitions in the perovskite-like NaTaO 3 , from room temperature to 933 K. The room temperature orthorhombic structure ( Pbnm , a = 5.4768(1), b = 5.5212(1), c = 7.7890(2)) transforms to orthorhombic Cmcm at around 700 K, then to tetragonal P 4…
The formation of transition-metal surface precipitates may occur during sorption to clay minerals under ambient soil conditions. This process may lead to significant long-term stabilization of the metal within the soil profile. However, the rates and mechanisms controlling surface precipitate formation are poorly unde…
New regulations for emission control require the improvement of the system composed by spark ignition internal combustion engine and three-way catalytic converter (TWC). In particular, an important problem is to minimize harmful emissions during the transient warm-up phase where the TWC is not working yet and, hence,…
The enantiomerically pure dendritic receptors with cleft-type recognition sites (dendroclefts) of generation zero ((−)-G0), one ((−)-G1), and two ((−)-G2) (Fig. 1) were prepared for the complexation of monosaccharides via H-bonding. They incorporate a rigid, optically active 9,9′-spirobi[9H-fluorene] core bearing 2,6-…