Materials Literature
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A binary Lennard-Jones alloy exhibits an entropically stabilized quasicrystal state in two dimensions at elevated temperatures. We consider the ground states of this model by calculating the convex hull of cohesive energy as a function of alloy composition. Only crystalline structures with rational values of the compo…
Abstract A series of thermotropic polyesters, derived from 4,4′‐biphenol (BP), 3‐phenyl‐4,4′‐biphenol (MPBP), and 3,3′‐bis(phenyl)‐4,4′‐biphenol (DPBP), 4,4′‐oxybisbenzoic acid (4,4′‐OBBA), and other aromatic dicarboxylic acids as comonomers, were prepared by melt polycondensation and were characterized for their ther…
Results are reported on the electron field emission properties of sulfur-incorporated nanocrystalline carbon (n-C:S) thin films grown by hot-filament chemical vapor deposition technique. The lowest turn-on field values observed were around 4.0–4.5 V/μm, which are about half of those measured for films grown without su…
Strukturelle Einzelheiten des Intermediats, das 200 ms nach Beginn der Ca2+-induzierten Rückfaltung von α-Lactalbumin vorliegt, wurden durch zeitaufgelöste Photo-CIDNP-NMR-Methoden ermittelt. Die Rückfaltung bei konstanter Konzentration an Denaturierungsmittel wurde durch laserinduzierte Ionenfreisetzung aus photolabi…
PbZr 0.5 Ti 0.5 O 3 /La 0.5 Sr 0.5 CoO 3 (PZT/LSCO) heterostructures have been grown directly on (100)Si by chemical solution routes. Field-emission scanning electron microscopy and x-ray diffraction analysis show that PZT and LSCO thin films are polycrystalline and entirely perovskite phase. PZT thin films grown on L…
We calculate the low-energy tunneling density of states $\ensuremath{\nu}(\ensuremath{\epsilon},T)$ of an $N$-channel disordered wire, taking into account the electron-electron interaction nonperturbatively. The finite scattering rate $1/\ensuremath{\tau}$ results in a crossover from the Luttinger liquid behavior at h…
A large quantity of metal Zn nanobelts have been synthesized by a simple approach, which involves thermal decomposition of ZnS powder, followed by Zn deposition.
Die Photooxidation einzelner Farbstoffmoleküle (siehe Schema) konnte mit konfokaler Fluoreszenzmikroskopie verfolgt werden. Die selbstsensibilisierte Reaktion mit Singulettsauerstoff führt zu einer Reihe von Produkten, die auf diese Weise erstmals spektral nachgewiesen und unterschieden werden können. Durch quantenche…
A study of the effect of microgravity on biomineralization/remineralization by considering Ca mineral nucleation under gravity and microgravity is presented. The structure of human bone is determined to a large extent by the turnover of the bone, which included nucleation of biominerals adjacent to biosubstrates. Hete…
Sorcin is a 22 kD calcium-binding protein that is found in a wide variety of cell types, such as heart, muscle, brain and adrenal medulla.It belongs to the penta-EF-hand (PEF) protein family, which contains five EF-hand motifs that associate with membranes in a calcium-dependent manner.Prototypic members of this famil…
Among oligosaccharides, trehalose seems to be unique in nature as a bioprotector in drying and freezing processes. To understand the molecular mechanisms underlying the unusual bioprotective properties of trehalose in comparison with other disaccharides, the low-frequency dynamics of aqueous $({\mathrm{H}}_{2}\mathrm{…
We study the charge ordering (CO) in the one-dimensional (1D) extended Hubbard model at quarter filling where the nearest-neighbor Coulomb repulsion and dimerization in the hopping parameters are included. Using the cluster mean-field approximation to take into account the effect of quantum fluctuations, we determine…
The [(M+)x[18]crown-6)] supramolecular cations (SC+), in which M+ and [18]crown-6 are alkali metal ions (M+ = Li+, Na+, and Cs+) and 1,4,7,10,13,16-hexaoxacyclooctadecane, respectively, form ionic channel structures through the regular stacks of [18]crown-6 in [Ni(dmit)2]-based molecular conductors (dmit2+ = 2-thioxo-…
We report on the operation of an integrated gated cathode device using a single vertically aligned carbon nanofiber as the field emission element. This device is capable of operation in a moderate vacuum for extended periods of time without experiencing a degradation of performance. Less than 1% of the total emitted c…
Density functional calculations on oxo-manganese complexes of corrole (1) and porphyrin (2 and 3) show a fundamental difference. The ground state of I is the singlet manganese(V) state, 1A(MnV), in which corrole is a closed shell. In contrast, 2 and 3 have high-spin manganese(IV) states, 1A1u and 3A2u respectively. Th…
A novel synthesis is presented of a fourfold ethynyl-substituted perylene diimide dye 4, which acts as a core molecule for the buildup of polyphenylene dendrimers. Around the luminescent core 4, a first-generation (5), a second-generation (6), and a third-generation (7) polyphenylene dendritic environment consisting o…
Supramolecular complex formation imparts stability and substrate selectivity to a simple manganese-porphyrin-based epoxidation catalyst. Lewis acid/Lewis base directed assembly was used to encapsulate the epoxidation catalyst within a supramolecular square structure to form an enzyme-like catalyst system. The “molecul…
The strain dependence of the solution energy of substitutional species is derived by expanding the binary alloy energy with respect to concentration and strain to the second order. Within the approximation of small strain and concentration inhomogeneities, the energy change is found to be proportional to the solute-in…
The orthorhombic rare-earth cobaltate ${\mathrm{Nd}}_{0.67}{\mathrm{Sr}}_{0.33}{\mathrm{CoO}}_{3}$ is studied by neutron powder diffraction. The Co sublattice orders ferromagnetically below ${T}_{c}\ensuremath{\approx}200$ K with the magnetic moments aligned along the c axis. On cooling, ${\mathrm{Nd}}_{0.67}{\mathrm{…
The resistances of individual single-walled carbon nanotubes (SWNTs) are calculated based on Boltzmann transport equation, graphene approximation relation of electronic energy for SWNTs and weak localization (WL) theory. The theoretical results of resistance for SWNTs are compared with experimental measurements. It ha…