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We theoretically investigate the propagation properties of cosh-Airy beams, which can be considered as a superposition of two Airy beams with different decay factors. We find that the field distribution of cosh-Airy beams is the same as that of Airy beams. Moreover, we find that the evolution of cosh-Airy beams is determined by the parameters of the cosh modulation function, in addition to the transverse scale factor and decay factor of the Airy beams. Our results demonstrate a possible method of manipulating Airy beams in free space. They can also be extended to the study of the propagation properties of cosine-Airy beams (or sine-Airy beams). [ABSTRACT FROM PUBLISHER]

We investigate the propagation of an Airy beam along the optical axis of a uniaxial medium, and we find that the propagation property of the Airy beam is determined by the ordinary refractive index of uniaxial crystals and is independent of the ratio of the extraordinary to ordinary refractive index. We also know that the polarization state of linearly polarized Airy beams changes gradually during the propagation. This shows that the propagation properties of the Airy beam in uniaxial crystals along the optical axis is distinctly different from that orthogonal to the optical axis. [ABSTRACT FROM PUBLISHER]

As the most fundamental deformation mechanism in metallic glasses (MGs), the shear banding has attracted a lot of attention and interest over the years. However, the intrinsic properties of the shear band are affected and even substantially changed by the influence of non-rigid testing machine that cannot be completely removed in real compression tests. In particular, the duration of the shear banding event is prolonged due to the recovery of the stressed compliant frame of testing machine and therefore the temperature rise at the operating shear band is, more or less, underestimated in previous literatures. In this study, we propose a model for the ‘ideal’ shear banding in metallic glass. The compliance of the testing machine is eliminated, and the intrinsic shear banding process is extracted and investigated. Two important physical parameters, the sliding speed and the temperature of shear band, are calculated and analysed on the basis of the thermo-mechanical coupling. Strain-rate hardening is proposed to compensate thermal softening and stabilise the shear band. The maximum value of the sliding speed is found to be on the order of 10 m/s at least, and the critical temperature at which strain-rate hardening begins to take effect should reach as high as 0.9Tg(Tgis the glass transition temperature) for a stable shear banding event in metallic glass according to the early experimental data. This model can help to understand and control the shear banding and therefore the deformation in MGs. [ABSTRACT FROM PUBLISHER]

To attain the economical wheel steels with high strength, the microstructure and properties of steel with microstructure consisting of ferrite and martensite were studied. The transformation behaviour of the economical wheel steels under continuous cooling condition and stepped cooling condition were researched and the 11·0-mm thickness wheel steel strips with simple chemical composition were developed on compact strip production (CSP) line with later ultra fast cooling (UFC) system. The results indicate that the dynamic continuous cooling transformation (CCT) curves of low carbon Mn-Cr steel is characterised by a large ferrite region, and the stepped cooling pattern is more beneficial to achieve ferrite-martensite microstructure than continuous cooling pattern. In order to obtain adequate polygonal ferrite matrix during stepped cooling process, the early cooling temperature should be controlled in the range of 700-660°C and the isothermal holding time should be ensured. The 11·0-mm thickness dual phase (DP) wheel steel strips are achieved on CSP line via control cooling technology based on later UFC system. Tensile strength increment of C-Mn-Cr steels can reach 130-170 MPa when the F-P microstucture is replaced by F-M microstucture. The wheel steel strips with tensile strength above 590 MPa, yield ratio under 0·62 and elongation above 28% have been used for wheel discs, whose weight achieve reduction of 16-22%. [ABSTRACT FROM AUTHOR]

Pd modified BiOBr flower-like microspheres have been synthesised via a facile one-pot ethylene glycol assisted solvothermal process in the presence of reactable ionic liquid 1-hexadecyl-3-methylimidazolium bromide ([C16mim]Br). The as prepared samples were characterised by multiple techniques to investigate the structure, morphology and photocatalytic properties. Ionic liquid [C16mim]Br was introduced to improve the dispersity of Pd nanoparticles, so as to construct the tight junctions between Pd nanoparticles and BiOBr. The Pd nanoparticles could distribute uniformly on the surface of BiOBr. The photocatalytic abilities of the as prepared photocatalysts were evaluated using rhodamine B (RhB) and ciprofloxacin as target pollutants. After the introduction of Pd, the photocatalytic activities of Pd/BiOBr composites have been enhanced under visible light irradiation. The 0·5 wt-% Pd/BiOBr possessed the optimal photocatalytic activity, which was about 6·6 times higher than pure BiOBr for the degradation of RhB. The results of diffuse reflectance spectroscopy, photoluminescence, photocurrent and electrochemical impedance spectroscopy demonstrated the enhanced photocatalytic performance could be attributed to the introduction of Pd, which improves the separation efficiency of the photogenerated electrons and holes. The trapping experiments of radicals indicated that hole was the main reactive species for the photocatalytic degradation of RhB. A possible photocatalytic mechanism was proposed that the Pd nanoparticles promote charge transfer, and inhibit the recombination probability of the photogenerated electrons and holes, which is beneficial for improving the photocatalytic performance of BiOBr. [ABSTRACT FROM AUTHOR]

Catalytic combustion of Qiannan inferior coal added with 1% single catalyst or 1% composite catalyst was studied by thermo-gravimetric experiments, X-ray diffraction analysis, and scanning electron microscope observation. Additionally, kinetic parameters of the coal combustion with or without catalysts were calculated. The results indicated that the apparent activation energy of the coal combustion was reduced with the catalysts. The ignition temperature and burnout temperature of the coal were decreased when catalyzed by the catalysts. The composite catalyst had a more excellent behavior on catalysis. Meanwhile, the X-ray diffraction and scanning electron microscope analysis provided a basis for further mechanism discussion of catalytic combustion. [ABSTRACT FROM PUBLISHER]

Catalytic combustion of Huarun anthracite in cement industry with NaClO4, MnO2, and ZnO was studied using thermogravimetric analysis. Ignition temperature, burnout index, and the quantity of heat releasing had been put forward to describe the catalytic activity. The results indicated that the catalysts can decrease the ignition temperature and increase the burnout index simultaneously; the catalytic activity of the catalysts on the ignition and burnout characteristics were in the order of NaClO4> MnO2> ZnO and MnO2> ZnO > NaClO4, respectively. Furthermore, the quantity of heat releasing of the coal with NaClO4was the highest. Thus, NaClO4had an excellent performance among these catalysts. Catalyzed combustion mechanisms of the coal samples were also discussed.% [ABSTRACT FROM PUBLISHER]

This paper on three heteroleptic {(bpy)2Ru[2-(perylen-3-yl)-1-H-imidazo[4,5-f][1,10]-phenanthroline)]}2+, {(bpy)2Ru[2-(pyren-1-yl)-1-H-imidazo[4,5-f][1,10]phenanthroline]}2+ and {(bpy)2Ru[2-(anthracen-10-yl)-1-H-imidazo[4,5-f][1,10]phenanthroline]}2+ complexes with perylene, pyrene and anthracene appended 1-H-imidazo[4,5-f][1,10]-phenanthroline as the diimine ligands is a further demonstration of the effect of extending the diimine ligands' π-system on the absorption and emission properties. [ABSTRACT FROM AUTHOR]

Intensive greenhouse vegetable-production systems commonly utilize excessive fertilizer inputs that are inconsistent with sustainable production and may affect soil quality. Soil samples were collected from 15 commercial greenhouses used for tomato production and from neighboring fields used for wheat cropping to determine the effects of intensive vegetable cultivation on soil microbial biomass and community structure. Soil total nitrogen (N) and organic-matter contents were greater in the intensive greenhouse tomato soils than the open-field wheat soils. Soil microbial carbon (C) contents were greater in the greenhouse soils, and soil microbial biomass N showed a similar trend but with high variation. The two cropping systems were not significantly different. Soil microbial biomass C was significantly correlated with both soil total N and soil organic matter, but the relationships among soil microbial biomass N, soil total N, and organic-matter content were not significant. The Biolog substrate utilization potential of the soil microbial communities showed that greenhouse soils were significantly higher (by 14%) than wheat soils. Principal component (PC) analysis of soil microbial communities showed that the wheat sites were significantly correlated with PC1, whereas the greenhouse soils were variable. The results indicate that changes in soil microbiological properties may be useful indicators for the evaluation of soil degradation in intensive agricultural systems. [ABSTRACT FROM AUTHOR]

A laser ablation/pulsed molecular jet system has been used to record high-resolution laser excitation spectra of the [image omitted]2A'- [image omitted]2A' transition of CaSH and the [image omitted]2A'- [image omitted]2A', [image omitted]2A''- [image omitted]2A', and [image omitted]2A'- [image omitted]2A' transitions of SrSH. The rotationally-resolved data were analysed using an asymmetric top Hamiltonian (A-reduction) to determine rotational and fine structure parameters. A combined fit of all the newly measured and the previously recorded spectroscopic data for both CaSH and SrSH was performed. In the excited states observed in this study, both species were found to have a bent geometry. The spin-rotation parameters were analysed in terms of the pure precession and unique perturber approximations. In the excited electronic states of SrSH, the large spin-rotation interaction was found to cause perturbations between the Ka = 0 and 1 levels within each state. In the [image omitted]2A' and [image omitted]2A'' states of both species, the metal-sulfur bond length was found to decrease relative to the ground state, which is consistent with previous observations of other calcium and strontium radicals. [ABSTRACT FROM AUTHOR]

WITHDRAWN TO APPEAR IN SPECIAL ISSUE IN 2007 [ABSTRACT FROM AUTHOR]

Family investigation is a reliable model to study the effects of both genetic and environmental factors on human health. This article studies kidney-yang deficiency syndrome and cold syndrome through family investigation and cDNA microarray technology, exploring the effects of both genetic and environmental factors on the health of family members. Particularly, these two syndromes were first assessed by the accumulated clinical scores measured by 40-item scoring tables among 15 family members. The family patterns were obtained and the correlation of these two syndromes was determined. Then the gene differential expression profiles among 12 family members were obtained using an 18,816 clones cDNA microarray. The profiles of the patients with typical kidney-yang deficiency syndrome and cold syndrome were compared to those of normal members and 89 differential expression genes were found. Further, only 22 genes were identified as known functions, and most (16 genes) were associated with the regulation of metabolism, temperature feeling, and growth. Therefore, the formation and development of these two syndromes have not only genetic but also environmental factors, including living conditions and lifestyle. [ABSTRACT FROM AUTHOR]

Three intersection mechanisms with the gliding planes (111)[sub TB], (001)[sub TB] and (115)[sub TB] respectively have been observed by high-resolution electron microscopy in the type-I twin intersection of gamma-TiAl. It was found that the intersection mechanism that occurred was related to the thickness of the incident twin. The accommodation mechanism on the (111)[sub TB] atomic plane is preferred when the incident twin becomes very thin. The dislocation dissociations of the (111)[sub TB] plane accommodation are the most energetically unfavourable of the dissociations of the three intersection mechanisms; however, the resultant dislocations on the (111)[sub TB] planes are the easiest to propagate away from the intersection area. Accordingly, (111)[sub TB] atomic plane accommodation is considered to be the only mechanism allowing shear transmission under the small local stress of the pile-up of the incident twinning partials. [ABSTRACT FROM AUTHOR]

Nanotwins related to the type-I twin intersection in gamma-TiAl have been investigated by high-resolution electron microscopy. A triangular striated region can be formed around the twin intersection. Some nanotwins were observed to nucleate through interfacial dislocation reactions on the incoherent twin boundary of the triangular striated region. The nanotwins, which propagate by a twinning dislocation homogeneous glide mechanism, are mostly limited to the triangular striated region. [ABSTRACT FROM AUTHOR]