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。
We investigate the degree of grain boundary positional disorder in computer generated fcc nc-Ni samples, as a function of grain size. We find that these grain boundary atoms display a lack of a second peak in the pair distribution function by virtue of their classification, and find further that such a class of atoms…
A series of organogelator salts has been prepared from n -alkylamines by the rapid in situ and isothermal (at room temperature) uptake of a neutral triatomic molecule, CO 2, NO 2, SO 2, or CS 2 . The organogels have been examined by differential scanning calorimetry, optical microscopy, and X-ray diffraction methods.…
A new bidentate “building block”, N,N ‘ -bis(3-pyridylformyl)piperazine (bpfp), was synthesized. X-ray diffraction studies reveal that the piperazine ring in bpfp forms a chairlike structure conformation. bpfp self-assembled into two-dimensional layered rhombohedral grid polymers {[Mn(H 2 O) 2 (SO 4 )(bpfp)](H 2 O) 3…
The formation of polyelectrolyte multilayers using the layer-by-layer sequential self-assembly of a weak polybase and polyacid onto a surface of Si crystal and their stability under acidic conditions were studied. The system was 12%, 20%, 25%, 37%, 90%, or 98% quaternized poly-4-vinylpyridine (Q12, Q20, Q25, Q37, Q90,…
Density functional theory geometry optimizations and reduction potential calculations are reported for all five known oxidation states of [Fe(4)S(4)(SCH(3))(4)](n)()(-) (n = 0, 1, 2, 3, 4) clusters that form the active sites of iron-sulfur proteins. The geometry-optimized structures tend to be slightly expanded relati…
The introduction of neutron spallation-source instruments, such as the General Materials Diffractometer (GEM) at ISIS, allows measurement of pair distribution function (PDF) data at significantly higher rates than previously possible. As a result of the increased rate, a single experiment can produce over a hundred in…
The most popular estimator of structural similarity is the root-mean-square distance (r.m.s.d.) between equivalent atoms, computed after optimal superposition of the two structures that are compared. It is known that r.m.s.d. values do not depend only on conformational differences but also on other features, for examp…
We calculate the photonic band gap of triply periodic bicontinuous cubic structures and of tubular structures constructed from the skeletal graphs of triply periodic minimal surfaces. The effect of the symmetry and topology of the periodic dielectric structures on the existence and the characteristics of the gaps is d…
The electronic properties of thin metallic films deviate from the corresponding bulk ones when the film thickness is comparable with the wavelength of the electrons at the Fermi level due to quantum size effects (QSE). QSE are expected to affect the film morphology and structure leading to the low temperature (LT) ``e…
Thermoelectric effects in Kondo insulators are attracting interests because of the emerging possibility of developping better thermoelectric materials for a portable refrigerator without liquid coolant. In this article, the theory of thermoelectric effects are reinvestigated for insulators or semiconductors at low tem…
We show that in mixed-valence 3d transition metal oxides undergoing a structural transition, the low temperature phase results from an effective ordering of the charge. This arrangement and the quantitative evaluation of the atomic charges are determined by using resonant x-ray scattering experiments further analyzed…
Often a number of precipitation processes in steels and alloys occur simultaneously (they have the same origin in time) albeit at different rates. Consequently, isothermic transformations are accompanied, in this case, by the occurrence of second processes of precipitation that influence the changes of the macroscopic…
We discuss the triple-$\vec{q}^X$ structures for the ordered cubic phase of NpO$_2$, which are $Pn{\bar 3}m$ and $Pa{\bar 3}$. A special care should be taken to discriminate between these two cases. We analyze the relevant structure-factor amplitudes and the effect of domains on resonant X-ray scattering experiments.…
SUMMARY: Protein topology cartoons are a representation of structural data commonly used by structural biologists to illustrate the relationship between one-dimensional sequence and three-dimensional structural data in a convenient two-dimensional format. TopDraw is a simple, freely available TCL/Tk based drawing prog…
A quadrupole coupling induced $^{\mathrm{47}}\mathrm{T}\mathrm{i}$ and $^{\mathrm{49}}\mathrm{T}\mathrm{i}$ satellite background which transforms into well-defined satellite lines below ${T}_{c}$ in the ferroelectric phase has been observed in the cubic phase of an ultrapure ${\mathrm{B}\mathrm{a}\mathrm{T}\mathrm{i}\…
The computer program ANIZC has been developed using the Pascal programming language for the calculation of diffraction contrast factors of dislocations in elastically anisotropic cubic, hexagonal and trigonal crystals. The contrast factor is obtained numerically by integrating the angular part of the distortion tensor…
Abstract The nonisothermal crystallization of multiwall carbon nanotube (MWNT)/isotactic polypropylene (iPP) nanocomposites was investigated. The results derived from the differential scanning calorimetry curves (onset temperature, melting point, supercooling, peak temperature, half‐time of crystallization, and enthal…
Hydrophobic cotton fibers, obtained by acylation of cellulose with fatty acid using microwaves radiations, have a high selective affinity for vegetable or mineral oil, fuel, and petroleum, in aqueous medium. Their sorption capacity (SC) (weight of liquid picked up by a given weight of sorbent) is about 20 g/g, after d…
The results of a single-crystal structure determination when in CIF format can now be validated routinely by automatic procedures. In this way, many errors in published papers can be avoided. The validation software generates a set of ALERTS detailing issues to be addressed by the experimenter, author, referee and pub…
A straightforward electrical technique for determining the thermal time constant of microbolometer structures is presented. An impedance measurement of a microbolometer using an LCR meter shows that the phase lag/lead reaches a maximum as a function of frequency. It is shown that the frequency of maximum phase differe…