Materials Literature
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The temperature and field dependence of alternating-current (ac) susceptibility in a Ni 50 Mn 25 Ga 25 single crystal was measured using an ac susceptometer with a dc magnetic field oriented in the [100] and [110] directions, respectively. It is found that even at very low fields the premartensitic transition temperat…
The luminescence enhancement of Tb 3+ ion bound to amphiphilic linear−dendritic block copolymers [poly(acrylic acid)−dendritic polyether, PAA−Dendr.PE] was investigated. Tb 3+ ion complexes with a PAA chain of block copolymer to form a supramolecular luminophore. The observed prominent enhancement in luminescence prop…
Free-exciton recombination emission of 235 nm in wavelength is obtained by current injection at room temperature from a diamond-based pn junction diode composed of B-doped crystal grown by high-temperature, high-pressure synthesis and a S-doped homoepitaxial layer grown by the chemical vapor deposition method. The dio…
Absorption of far-infrared (FIR) radiation in very small CdSe crystallites (quantum dots, QDs) via excitation of confined dipolar vibrational modes was studied, both theoretically and experimentally. Spatial quantisation of optical phonons was analysed in the framework of a continuum model, which couples the phonon am…
The new anionic carbon sulfides C6S10(2-) and C12S16(2-) are described and crystallographically characterized. The C12S16(2-) anion consists of two C6S8 units connected by an exceptionally long (2.157(12) A) S-S bond. In solution, C12S16(2-) exists in equilibrium with the radical C6S8(-*). The equilibrium constant for…
Powder mixtures of SmxCo5 (x=0.65–1.3)+20 wt % α-Fe were mechanically milled. Annealing these as-milled powders results in the formation of a mixture of the hard phase Sm–(Co, Fe) and the soft phase Fe–Co. For the as-milled Sm1Co5+20 wt % α-Fe powder, the hard phase changes with the increase of annealing temperatures.…
The mechanism of the ferroelectric transition in KH 2 PO 4 -type crystals has been probed using magic angle spinning 31 P NMR on single crystals. The higher resolution thus obtained has enabled us to detect a marked change in the 31 P isotropic chemical shift around the transition temperature T c , with a clear jump a…
Up to now, liquid crystalline elastomers have been strenuously studied to obtain high orientation induced by mechanical fields. It is known that a uniaxial mechanical field is sufficient to obtain macroscopically uniform alignment for nematic and smectic A liquid crystalline elastomers having uniaxial symmetry. Here t…
The tensile and compressive behaviours of knitted composites in the wale and course directions were studied for their dependence upon knit architecture and varying knit/structural parameters, such as loop length and stitch density. Strength, modulus and strain-to-failure were investigated. In addition, Poisson’s ratio…
In the case of ultrasound application in biological tissues, gas bubbles might form and collapse within cells, in the intercellular spaces and on tissue surfaces. In this work the effect of confined space on the behavior of the gas bubble in the presence of ultrasonic field is studied. A numerical model for bubble pul…
An engineering function to describe the AC loss of BSCCO/Ag tape conductors is developed. For a wide range of transport currents and magnetic fields (with different orientation) the loss is described with an uncertainty of 10%. The equation is based on the analytical expressions available, BSCCO/Ag tapes used in power…
Aluminum-doped zinc oxide films are promising candidates for economic transparent conducting oxide (TCO) applications. To reach high deposition rates (about 7 nm/s at 4.5 W/cm2) in combination with optimum TCO properties by using the reactive mid-frequency sputtering technique, the process window must be precisely con…
Interconnected‐phase mullite–aluminum metal–ceramic composites were processed using the indirect fused‐deposition process. In this process, controlled‐porosity ceramic preforms were fabricated via the lost‐mold process. The molds were designed with computer aided design (CAD) software and fabricated using a fused‐depo…
The analysis of the phase behavior of a smectic A (SA) elastomer reveals a nematic phase existing within a small temperature range below the isotropic state. Stress-optical measurements in the pretransformational regime of the isotropic state indicate smectic as well as nematic fluctuations yielding a critical exponen…
While theoretical and experimental efforts have thoroughly addressed microphase-ordered AB diblock copolymer blends with a parent homopolymer (hA or hB) or a second block copolymer, surprisingly few studies have considered comparable ABA triblock copolymers in the presence of hB or an AB diblock copolymer. In this stu…
The radial, circular, and axial components /spl sigma//sub r/, /spl sigma//sub /spl phi//, and /spl sigma//sub x/, of the residual stress tensor in amorphous wires made by quenching in rotating water are derived from the classical elasticity theory on the assumption that the density decreases from the wire surface (r=…
The second-order nonlinear-optical coefficients of CsLiB6O10 have been absolutely determined for visible-to-ultraviolet second-harmonic wavelengths. The measurements were made by use of the wedge technique at the fundamental wavelengths of 0.532, 0.852, and 1.064 µm. The following values were obtained: d36=0.92 pm/V a…
Nanocrystalline carbon films possessing a prevailing diamond character are deposited by a direct current glow discharge chemical vapor deposition method using a 9:91 vol % methane to hydrogen gas mixture. In the present work the evolution and properties of nanodiamond films deposited by this method onto silicon substr…
The water-gas shift (WGS) reactor is a key component in fuel processors, but existing WGS catalysts are unsuitable for transportation applications, since the iron-chrome catalysts used at high temperatures are relatively inactive, and the copper-based catalysts used at low temperature tend to degrade under the severe…
Aqueous solutions of boehmite and hydrofluoric acid (HF) were used to prepare homogeneous mixtures of alumina and aluminum fluoride. Calcination at temperatures as low as 1000°C resulted in the formation of well‐defined hexagonal‐shaped α‐alumina platelets. Containment of the aluminum fluoride by covering the calcinat…