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。
A layered manganese oxide nanocomposite (PDDAMO) with poly(diallyldimethylammonium chloride), PDDA, incorporated between manganese oxide sheets, was synthesized by a delamination/reassembling process. The product was characterized by powder X-ray diffraction, elemental analysis, thermal analysis, FT-IR spectroscopy, a…
We report a study of second-order combination and overtone modes in highly ordered pyrolytic graphite (HOPG), in single-wall carbon nanotube (SWNT) bundles and in isolated SWNTs. We found both dispersive and nondispersive Raman bands in the range $1650--2100{\mathrm{cm}}^{\ensuremath{-}1},$ and we show that the appear…
In this paper, the three-dimensional Landau model of austenite-martensite transformations constructed in Part I is generalized to include transformations between an arbitrary number of martensitic variants. The model can incorporate all temperature-dependent thermomechanical properties of both phases for arbitrary cry…
The harmonic Frenkel-Kontorova model is used to illustrate with an exactly solvable example a general technique of mapping a coherently strained epitaxial system with continuous atomic displacements onto a lattice gas model (LGM) with only discrete variables. The misfit strain of the original model is transformed into…
The persistence length of a single, intrinsically rigid polyelectrolyte chain, above the Manning condensation threshold is investigated theoretically in presence of added salt. Using a loop expansion method, the partition function is consistently calculated, taking into account corrections to mean-field theory. Within…
The microscopic structure of a prismatic $\ensuremath{\Sigma}3(101\ifmmode\bar\else\textasciimacron\fi{}0)$ twin boundary in $\ensuremath{\alpha}\ensuremath{-}{\mathrm{Al}}_{2}{\mathrm{O}}_{3}$ is characterized by combining ab initio local-density-functional theory, electron energy-loss spectroscopy measuring energy-l…
Kinetics of dislocations is studied by means of computer simulation during intensive plastic deformation. The dynamical effect in the form of soliton-like wave of sharply disrupted interparticle bonds is observed. Along with it, micropores similar to steam bubbles at water boiling are formed. After some deformation th…
Results on the chemical composition, structure and growth kinetics of titanium nitride (TiN) films deposited on mild steel substrates by pyrolytic laser-induced chemical vapour deposition (LCVD) are presented. Golden coloured lines of TiN were deposited from a reactive gas mixture of TiCl4, N2 and H2 using a continuou…
A 30 nm Pt thin film evaporated onto a Si wafer was sputtered by 8 keV Ar$^{+}$ ions at various ion doses. The evolution of the modified sputtered films was monitored by atomic force microscopy (AFM), high resolution scanning electron microscopy (HRSEM) and Rutherford backscattering spectrometry (RBS). The most intere…
A three-dimensional Landau theory of stress-induced martensitic phase transformations is presented. It describes transformations between austenite and martensitic variants and transformations between martensitic variants. The Landau free energy incorporates all temperature-dependent thermomechanical properties of both…
We present the structural and optical characterization of colloidal PbSe nanocrystals. The lowest-energy exciton transitions in these structures, with diameters between 3 and 8 nm, occur at wavelengths between 1.0 and 1.85 μm. Band-edge luminescence spectra with quantum yields as high as 80% are observed. Unexpectedly…
The crystal structure of chlorofluoromethane, CH(2)ClF, has been determined at 100 and 30 K using indexing, packing considerations and Rietveld refinement of neutron powder profiles. There is only one phase, in monoclinic space group P2(1) and with two molecules in the unit cell occupying general positions. The struct…
The title compound, SrZnCoFe(16)O(27) (ZnCo-W), strontium zinc cobalt hexadecairon oxide, crystallizes in space group P6(3)/mmc, with the Sr atom at a site with -6 m 2 symmetry and Zn(2+) located at two tetrahedral sites (4e and 4f, each with 3m symmetry) of the spinel blocks. The Zn occupancy is 36% on equipoint 4e a…
A simple, new TEM specimen holder to detect cathodoluminescence (CL) in a transmission electron microscope has been developed. This holder accommodates a flat light-collecting reflector below the specimen and CL signals are guided to an optical spectrometer outside of the microscope through a quartz optical fibre. The…
We introduce two new sulfur functionalised phosphines P(C6H4SMe)3L1 and PPh2C6H4SMe L2. Using them as ligands, four new copper selenium clusters were synthesized. The compounds [Cu15Se3(SePh)9(P(C6H4SMe)3)6] 1, [Cu22Se6(SePh)10(PPh2C6H4SMe)8] 2, [Cu20Se(SePh)12(OAc)6(PPh2C6H4SMe)2] 3 and [Cu38Se4(SePh)24(OAc)6(PPh2C6H…
Thin films of barium aluminate (BaAl 2 O) 4 ) doped separately with thulium, terbium, and europium were deposited by a spray pyrolysis method. The effects of preparation conditions on the structural and luminescence properties of the films were investigated. Polycrystalline BaAl 2 O 4 films were formed at an annealing…
The enzyme hydroxymethylbilane synthase (HMBS, EC 4.3.1.8), 313 amino acid residues and MW 34 kDa, also known as porphobilinogen deaminase (PBGD), catalyses the stepwise polymerization of four molecules of porphobilinogen (PBG) to the linear tetrapyrrole 1-hydroxymethylbilane. Several crystallographic structures of HM…
Protoporphyrin reacts with diazomethane to give pyrazolines which at long wavelength (approximately 630 nm) extrude nitrogen to give the corresponding cyclopropyl derivatives.
This study discusses the development of an atmospheric pressure glow discharge enhanced CVD system for the catalytic growth of carbon nanotubes (CNTs). He/H 2 /CH 4 (900 : 100 : 0–20 scc min −1 ) gas mixture was processed in the barrier discharge reactor operated at 760 Torr. Ni-coated (20 nm) quartz substrate was use…
Electrical conduction in non-conjugated insulating polymers such as Kapton (R) films was studied as a function of temperature, T (15–500 K) and electric field F (⩽16 kV cm −1 ). The time dependent isothermal transient currents (ITC) were also studied at different temperatures (15 K< T <500 K). Thermally stimulated dis…