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The dynamics of polarization switching have been investigated over extremely broad time (10-8< t< 10² s) and field ranges for (001) c, (110) c, and (111) c-oriented Pb (Zn 1/3 Nb 2/3) O 3-4.5%PbTiO 3 crystals. The results demonstrate the presence of broad relaxation time distributions that can extend over a decade (s) in orders of magnitude in time, and which sharpen significantly with increasing field. The polarization transients have been fit to stretched exponential functions, which are typical of disordered systems. [ABSTRACT FROM AUTHOR]

Highlights • The IGC resistance difference of the Al-Cu-Li alloys with different Zn-additions is investigated. • Three types of phase at GBs were confirmed. • Zn exists in the coarsen phase at the GBs. The quantity and space of the coarse phases at the GBs are attached to Zn-addition. • The potential difference between the conversed coarse phase and adjacent zone decreases contributing to the increasing corrosion resistance. Abstract The influence of various amounts of Zn addition on the microstructure and associated intergranular corrosion of Al-2.8Cu-1.7Li-0.4Mg-0.3Mn-0.12Zr alloys was studied using transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy, and corrosion and electrochemical techniques. The added Zn was incorporated into the precipitates at the grain boundaries (GBs). Three types of phases at the GBs were confirmed. The quantity and space of the coarse phases at the GBs were related to Zn addition. The Zn addition decreased the potential difference between the conversed coarse phase (containing Zn) and the adjacent matrix, which improved the intergranular corrosion resistance. [ABSTRACT FROM AUTHOR]

Degradation of organic pollutants in industrial wastewater has become one of the biggest problems that are threatening the environment, and correspondingly it is a priority for scientists to find a solution. In this work, we study the effect of the iron content in Fe-based amorphous ribbon catalysts (Fe 78+x Si 9 B 13-x , x = 0, 1 and 2) in degradation of Direct Blue 6 (DB 6) azo dye by Fenton-like process. We evaluated the catalytic efficiency by changing experimental conditions with the aim to optimize the degradation performance. The amorphous Fe 80 Si 9 B 11 ribbon showed the highest catalytic activity with its ability to degrade DB 6 by 94.65% within 15 min Fe 80 Si 9 B 11 ribbon provides more reactive sites than what generates the most hydroxyl radicals (. OH) and thus increases the degradation reaction. Degradation efficiency can be improved by increasing the reaction temperature and ribbons dosage, a correct amount of H 2 O 2 but decreases with increasing initial pH value and concentration of DB 6. Fe 80 Si 9 B 11 amorphous ribbons can be reused up to 12 times in optimal conditions, which confirms a good reusability. The excellent performance in catalytic activity and reusability of Fe-based amorphous alloy catalysts will contribute to wastewater treatment. [Display omitted] • Fe-based amorphous ribbons with different Fe contents were prepared. • The ribbons are good catalysts in degradation of DB 6 by Fenton-like reaction. • A slightly higher Fe content can improve the catalytic property significantly. • The kinetic of dye degradation process was studied. • High reusability with acceptable dye degradation efficiency was illustrated. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations based on an embedded-atom-method potential were performed to examine the structural and dynamical properties of the solid-liquid interfaces in the Cu-Ni alloy system with different orientations of the solid, i.e. (1 0 0), (1 1 0) and (1 1 1). The profiles of local order parameter, atomic number density, diffusion coefficients and Lindemann indices were evaluated and the interface widths were determined based on them. The widths are found to depend on the orientation of the underlying solid, while the orientation dependence for widths based on different criteria differs. The ones based on the local order parameter, given as the difference between an actual local atomic configuration and a referential ideal crystalline one, are found to be able to reflect the transitions across the interface in terms of both geometry and atomic motility, and are therefore most reliable. The interfacial layers are found to be composed of mixtures of both solid and liquid phases, the tempo-spatial variations of their relative amounts play an important role in determining the interfacial properties, including the interfacial widths. These findings can lend support to model the behavior of the solid-liquid interfaces at coarse grained scales, such as phase field modelling of dendrite growths. [ABSTRACT FROM AUTHOR]

The influence of 0.42 and 0.72 wt.% Zn on the intergranular corrosion (IGC) of Al–3.7Cu–1.15Li–0.5Mg and Al–2.7Cu–1.7Li–0.3Mg alloys (representing different Cu/Li ratios) was investigated. IGC dependence on ageing time was studied and a primitive IGC diagram established. With ageing, the potential of the Al –x Cu –y Li alloys lowered due to precipitation, accompanied by grain boundary precipitate coarsening. Concomitantly, corrosion mode evolved with ageing from pitting and local IGC (early ageing), general IGC (under-aged), local IGC (near peak-aged) and pitting (over-aged). Of key interest is that Zn additions remarkably decreased the IGC sensitivity of the Al–2.7Cu–1.7Li–0.3Mg. [ABSTRACT FROM AUTHOR]

• Cr3+ substituted ZnFe 2 O 4 nano-ferrites have been successfully prepared by co-precipitation method. • XRD studies confirmed the formation of cubic spinel structure. • Magnetic properties were influenced significantly by Cr3+ substituted zinc nano-ferrites. • The photocatalytic degradation efficiency of methyl orange were enhanced with increased Cr3+ substitution. In this paper, the Cr3+ substituted zinc ferrite (ZnCr x Fe 2-x O 4 with x = 0, 0.15 and 0.25) nanoparticles with single cubic spinel structure (Fd-3 m space group) were prepared by chemical co-precipitation method, and their structure and optical, magnetic and photocatalytic performaces were investigated. With Cr added, the lattice parameter and average grain size of the ferrites remarkably changed. High-quality nanostructured ferrite with an average particle size of 22–31 nm are revealed by TEM and SEM. The vibrational stretching modes of tetrahedral and octahedral sites were confirmed by FTIR. The optical studies proved a gradual decrease in the optical band gap which indicated the emergence of sub-band-gap energy levels by the chromium content. The magnetic properties were investigated through magnetization technique. The saturation magnetization measured from M-H hysteresis plot show decreasing trend with increase in Cr3+ content. The photocatalytic degradation of aqueous solution of Methyl Orange (MO) in the presence of prepared nano-ferrite under visible-light irradiation has been studied and discussed. The photodegradation efficiency of MO over ZnCr x Fe 2-x O 4 photocatalysts is enhanced; (69%, 74% and 82% with increasing Cr3+content, respectively) compared with its modest value 12% without addition. [Display omitted] [ABSTRACT FROM AUTHOR]

Characteristic of dislocations in TiB 2 particles associated with hypervelocity impact craters in 65 vol.% TiB 2 /Al composite were investigated by transmission electron microscopy (TEM). Two kinds of dislocation networks in as-impacted TiB 2 particles were identified. One is hexagonal dislocation networks including 1 / 3 〈 1 ¯   2   1 ¯   0 〉 , 〈0 0 0 1〉, 1 / 3 〈 1 ¯   2   1 ¯   3 〉 type dislocations on {0 0 0 1}, { 1   0   1 ¯   0 }, and { 1   2   3 ¯   0 } planes. Another one is the hexagonal dislocation networks including 1 / 3 〈 1   1   2 ¯   0 〉 , 〈0 0 0 1〉, and 1 / 3 〈 11 2 ¯ 3 〉 type dislocations on {0 0 0 1}, { 1   0   1 ¯   0 }, and { 1   1 ¯   0   0 } planes. Formation of dislocation network should be contributed to the parallel sets of “a” type dislocations ( 1 / 3 〈 1   1   2 ¯   0 〉 or 1 / 3 〈 1 ¯   2   1 ¯   0 〉 type dislocations) reacting with parallel sets of “b” type dislocations (〈0 0 0 1〉 type dislocations) to form “c” type dislocations ( 1 / 3 〈 1   1   2 ¯   3 〉 or 1 / 3 〈 1 ¯   2   1 ¯   3 〉 type dislocations). Moreover, dislocations reaction processes do not result in an energy reduction, and are called quasi-equilibrium configurations. Formation of dislocations may result from high temperature or pressure generated by hypervelocity impact. During the cooling from high temperature and unloading from high pressure, dislocations in TiB 2 particles rearranged and transformed to dislocation networks to lower the defect energy. [ABSTRACT FROM AUTHOR]

The effects of spongy graphene on the latent heat and thermal conductivity of the phase change material consisting of docosane and spongy graphene were studied. The latent heat and thermal conductivity of docosane/graphene composites were simultaneously enhanced in contrast to that of pure docosane. The latent heat increased from 256.1 J/g to 262.8 J/g, and the thermal conductivity increased more than 2 times in a low graphene concentration of ~3 mg/cm 3 . X-ray diffractometer, scanning electron microscopy, and Fourier-transform infrared spectrometer were used to characterize the microstructure of docosane and docosane/graphene composite. It is found that the crystallinity of layered docosane was enhanced in the presence of spongy graphene sheets acting as a nucleating agent, which resulted in the increase of latent heat. The enhancement of thermal conductivity for docosane/graphene composite is attributed to the high thermal conductivity of graphene. [ABSTRACT FROM AUTHOR]

Abstract: A series of Y2O3-promoted NiO/SBA-15 (9 wt% Ni) catalysts (Ni:Y weight ratio = 9:0, 3:1, 3:2, 1:1) were prepared using a sol–gel method. The fresh as well as the catalysts used in CO2 reforming of methane were characterized using N2-physisorption, XRD, FT-IR, XPS, UV, HRTEM, H2-TPR, O2-TPD and TG techniques. The results indicate that upon Y2O3 promotion, the Ni nanoparticles are highly dispersed on the mesoporous walls of SBA-15 via strong interaction between metal ions and the HO–Si-groups of SBA-15. The catalytic performance of the catalysts were evaluated at 700 °C during CH4/CO2 reforming at a gas hourly space velocity of 24 L gcat −1 h−1(at 25 °C and 1 atm) and CH4/CO2molar ratio of 1. The presence of Y2O3 in NiO/SBA-15 results in enhancement of initial catalytic activity. It was observed that the 9 wt% Y–NiO/SBA-15 catalyst performs the best, exhibiting excellent catalytic activity, superior stability and low carbon deposition in a time on stream of 50 h. [Copyright &y& Elsevier]

Highlights: [•] Orientation dependent ordering is induced in liquid Cu adjacent to solid Ta. [•] Intermixing of Cu and Ta as well as prefreezing of Cu are found on Ta (100). [•] Unexpected negative interfacial energy is deduced, as a result of the enhanced ordering of interfacial Cu layers. [•] Prefreezing of Cu leads to a double-interface for specific orientation. [•] Orientation dependence in structure in turn results in orientation dependence in interfacial energies and other profiles. [Copyright &y& Elsevier]

Highlights: [•] Ag grease, solder joint and Ag, Sn foils as TIMs all degrade remarkably at 170°C. [•] The degradation can be attributed to evolution of microstructure at interfaces. [•] The degradation challenges finding of TIMs for high temperature power electronics. [ABSTRACT FROM AUTHOR]

• (Co 1−x Ni x) 79.3 B 20.7 (x = 0, 0.25, 0.5, 0.75, 1) alloys were solidified at different undercoolings. • Partial substitution of Co by Ni reduces the possibility for metastable M 2 B. • All the Co-Ni-B alloys solidify into single metastable M 23 B 6 phase at large undercooling. • The stability of metastable M 23 B 6 phase becomes worse as the Ni content increases. • A vertical section of the Co-Ni-B phase diagram with a content of 20.7 at% B was drawn. [Display omitted] (Co 1−x Ni x) 79.3 B 20.7 (x = 0, 0.25, 0.5, 0.75, 1) alloys were solidified at different undercoolings, aimed at the effect of Co/Ni atomic ratio on the metastable phase formation and stability. Substitution of Co by Ni reduces the possibility for metastable M 2 B (M = Co or/and Ni) phase to form as primary solid at medium undercoolings. As a result, M 2 B phase completely disappears from the solidification of the alloys with x = 0.5, 0.75 and 1. All the Co-Ni-B alloys investigated solidify into single metastable M 23 B 6 phase at large undercooling. The stability of metastable M 23 B 6 phase however becomes worse as the Ni content increases, due to which it is decomposed into α-M and M 3 B phases in the post-solidification cooling process when x ≥ 0.75. A vertical section of the Co-Ni-B phase diagram with a content of 20.7 at% B was drawn, including the liquidus temperatures of M 3 B, M 2 B and M 23 B 6 phases and the eutectic temperatures of L → α-M + M 3 B and L → α-M + M 2 B. [ABSTRACT FROM AUTHOR]

Abstract: A fixed-grid source-based numerical method has been developed to simulate the diffusion-controlled growth of Cu6Sn5 and Cu3Sn intermetallic compounds (IMCs) and other many layers of IMCs. Data fittings of measured thicknesses of the IMCs to the simulated results can be further employed to determine the interdiffusion coefficients for the IMCs. Compared with the existing analytical methods, the present numerical method is not only more accurate, but also applicable to a wider range of experimental results. We report here the detailed formulation of the relevant equations, and compare and validate the present numerical method using experimental thicknesses of Cu6Sn5 and Cu3Sn IMCs from both the existing literature and the experiment of our own. The results obtained provide new insight into the interdiffusion coefficients for the Cu6Sn5 and Cu3Sn IMCs formed between Cu and Sn or Sn-based solders, or other many layers of IMCs formed in similar metal/metal systems. [Copyright &y& Elsevier]

Abstract: This paper reports the effect of the addition of 1wt% Al into 100Sn, 96.5Sn–3.5Ag (SA) and 95.5Sn–3.8Ag–0.7Cu (SAC) solders, on growth rates of intermetallic compound (IMC) layers between the solders and a Cu substrate. During reflow at 260°C under 2%H298%N2 forming gas for 5–120min, the most pronounced reduction in IMC growth was observed in the SAC–1Al/Cu system. This was accompanied with the evolution of a layer of η 2 (AlCu) IMC which was first formed within the bulk of the solder, then migrated towards and gradually replaced the previously formed η (Cu6Sn5) and ε (Cu3Sn) IMCs at the solder/Cu interface, and was finally transformed into δ (Al2Cu3) IMC and dispersed into the bulk of the solder again. A similar reduction in growth and associated evolution of IMCs was observed in the SAC–1Al/Cu samples subjected to thermal ageing at 170°C under air for 24–2096h. [Copyright &y& Elsevier]

Abstract: The use of flood cutting fluids in machining processes has been questioned lately due to the several negative effects on environment and health. Considerable attention has been given to reduce or completely omit the cutting fluids, and meet the demands for environment-friendly cutting processes. The low cooling capacity of the air limits the application of minimum quantity lubrication (MQL) in machining Inconel 718. The minimum quantity cooling lubrication (MQCL) system which combines the advantages of the cryogenic air and MQL, can improve the machinability of Inconel 718. In this work, dry cutting and MQCL cutting with biodegradable vegetable oil are associated to study tool wear and cutting forces during end milling Inconel 718 with coated cutting tools. Meantime, the relationship between tool wear propagation and the cutting force variations under different cutting conditions is also explored. The experimental results have shown that MQCL cutting with biodegradable vegetable oil can effectively improve the machinability of Inconel 718, such as extension of tool life and reduction of cutting forces. From an environmental point of view, MQCL cutting with biodegradable vegetable oil meet the increasing demands for cleaner manufacturing of Inconel 718, and is an alternative of MQL cutting and dry cutting. [Copyright &y& Elsevier]

Abstract: Co–24.0at.% Sn eutectic alloy melt was undercooled to different degrees below the equilibrium eutectic temperature. The dependence of solidification behavior on undercooling was established based on the experimental results of the solidification microstructure, crystal orientation and crystal growth velocity. In the entire undercooling range studied (0–203K), coupled eutectic growth of the α-Co and β-Co3Sn2 phases invariably takes place during the rapid solidification stage. The eutectic solidification interface advances in the alloy melt in seaweed morphologies rather than the well-known dendritic mode due to the weak interface energy anisotropy. But a critical undercooling of 175K exists, from which the eutectic solidification interface changes from a fractal into a compact seaweed pattern, accompanied with an abrupt increase of growth velocity. At high undercoolings the enhancement of the interface tip stability with the rise of crystal growth velocity should be responsible for the growth mode transition. [Copyright &y& Elsevier]

Abstract: A series of Zr–Cu glassy ribbons were fabricated, and the compositional dependence of microhardness in the as-quenched and annealed state was systematically investigated. The as-quenched microhardness exhibits a positive deviation from linearity at the compositions which correspond to local maximum in glass forming ability (GFA). Upon annealing, the microhardness change is relatively smaller for the high GFA compositions. High atomic packing density at the special compositions should be responsible for the microhardness behavior. [Copyright &y& Elsevier]

Abstract: The corrosion behavior of an Al–0.63Mg–0.28Si alloy under droplets of MgCl2 solution in environments of 75% and 33% RH was studied using a Kelvin Probe. The equilibrium chloride concentrations in these two environments are 5.8 and 9.8M chloride, respectively. In the 33% RH environment, metastable pitting was the main form of corrosion. In some cases at 75% RH, the potential baseline decreased slowly by hundreds of millivolts and remained at the lower value. These samples exhibited filiform-like corrosion inside micro-droplets that formed outside of the main MgCl2 drop. A model for the filiform-like attack in a micro-droplet is presented. [Copyright &y& Elsevier]

Abstract: A thin interlayer of pure Sn foil has been sandwiched between two pieces of Cu foil base metal and reflowed at 260, 300 and 340°C, under 2%H2/98%N2 forming gas, for 5 – 480min. We report here: (i) the interfacial microstructures to show Cu6Sn5 scallops and Cu3Sn columnar crystals; (ii) the pronounced difference in the thicknesses of the Cu6Sn5 and Cu3Sn layers formed at the two original boundary planes in the Cu/Sn/Cu samples; (iii) the diffusion-kinetic constants for the Cu6Sn5 and Cu3Sn growth derived from the Cu/Sn/Cu samples for a range of Sn interlayer thicknesses; and (iv) a type of grain boundary/molten channel-controlled growth of Cu6Sn5 with a time dependence similar to that for the volume diffusion-controlled growth. These results provide new insight into the mechanism and kinetics of the interfacial reaction between liquid Sn and solid Cu, and other similar metallic liquid/solid systems. [Copyright &y& Elsevier]

Abstract: The kinetics of the interfacial reaction of a thin layer of Sn sandwiched between two pieces of Ag foil has been investigated at temperatures of 260°C, 300°C and 340°C. A time dependence of the form t 1/ n with n =3 was obtained for the kinetics of both the consumption of the Sn remaining and the thickening growth of the Ag3Sn scallops formed between Sn and Ag. Such a result can be explained well using the model of grain boundary/molten channel-controlled growth of intermetallic compounds. In this case, the diffusion of Ag atoms through the molten channels existing between the previously formed Ag3Sn scallops is the controlling mechanism for the kinetics. We also report here the derived kinetic constants including reaction constants and the associated activation energy for guiding the practical transient liquid phase soldering of the Ag–Sn–Ag system. [Copyright &y& Elsevier]

Abstract: Cold sprayed Sn–Cu coatings approximately 40 and 25μm in average thickness were deposited on aluminium and direct bonded copper (DBC) substrates respectively. Both a statistical analysis of coating thickness and a roughness analysis of the coating/substrate interface and the coating surface were carried out for the as-sprayed coatings using scanning electron microscope images. The results obtained can be related to substrate types and spraying conditions. Tin oxide on the surfaces of the as-sprayed coatings was revealed by employing X-ray photoelectron spectroscopy analyses and transmission electron microscopy. It came from an oxide shell around feedstock powder particles and was only locally broken down during cold spraying. Although the tin oxide inhibited fluxless soldering, flux-supported reflow of cold sprayed Sn on the DBC substrate produced Cu/Sn/Cu solder joints that were acceptable for application in electronic packaging and interconnects. In general, measures which can avoid or remove the tin oxide are needed to achieve improved solder joints using cold sprayed Sn coatings as the solder layers. [Copyright &y& Elsevier]

Comments have recently been made by Yuan et al. [1] to deny one statement in our paper [2], Eq. (21) in Wagner's paper [3] can be used to accurately calculate the integrated interdiffusion coefficient for an incremental diffusion couple only under the assumption of constant Molar volume for all phases. We respond here to explain how they misunderstood our mathematical deduction, made a mistake in deriving a couple of equations, falsely cited our work and employed unjustifiable assumption. As a result, we believe that their comments are invalid to deny our statement. [ABSTRACT FROM AUTHOR]

We report a family of Sr-based bulk metallic glasses (BMGs) with good glass-forming ability and many unique properties, such as ultralow glass transition temperature T g, elastic moduli and less fragility than known BMGs. The T g of Sr60Li11Mg9Zn20 BMG is at room temperature (∼299K). Remarkably, the BMGs have tunable degradation behavior in water and the corrosion rate can be controlled by simply minor alloying, so that the full degradation time can be effectively modulated from minutes to more than weeks. [Copyright &y& Elsevier]

Abstract: The tensile properties, exfoliation corrosion behavior and microstructures of the retrogression and re-aging (RRA) treated aluminum (Al) alloy AA7150 were studied. AA7150 was retrogressed at different temperatures (175°C, 185°C and 195°C) for various times. It is found that as the hardness of the retrogressed AA7150 approaches the near-peak condition, the corresponding RRA treated AA7150 possesses good exfoliation corrosion resistance without strength loss. By retrogressing at 175°C, the retrogression time can be extended to 3h, the RRA treated AA7150 possesses a strength as high as that of conventional AA7150-T6, and its exfoliation corrosion resistance is in the vicinity to that of AA7150-T73. This enhanced exfoliation corrosion resistance was associated with the more separated η precipitates at the grain boundary. AA7150-T6 is mainly strengthened by fine GP zones with high number density, while the intra-grain micro-structure of AA7150-RRA retrogressed at 175°C for 3h is characterized by relatively coarse η′ precipitates. [Copyright &y& Elsevier]

Abstract: Ag–Cu eutectic alloy was undercooled by the glass flux method and the solidification structure was investigated. It is revealed that when undercooling is not more than 70 K, the large difference in composition between two eutectic phases and very large thermal diffusion coefficient of the liquid result in cellular growth of the lamellar eutectics from the nucleation site. The variation in interface temperature during rapid solidification gives rise to a systematic change in microstructure within the sample. With the distance along the growth direction increasing, the finest lamellar spacing across the cellular eutectic rises, which indicates a gradually decreasing growth velocity of the primary eutectics. The primary lamellar eutectics near the nucleation site solidify under conditions far from equilibrium, and therefore are supersaturated with solute, and then partially remelted and ripened into anomalous eutectics. As undercooling increases, the area of the anomalous eutectics enlarges. [Copyright &y& Elsevier]

Abstract: A theoretical model for lamellar eutectic growth in undercooled eutectic alloy melts with a third element has been developed; it was assumed that no other phase forms. It is found that the tip radius of eutectic dendrite decreases with increasing content of the third element so as to diffuse away its enriched atoms ahead of the solidifying interface easily. A critical content exists below which the eutectic growth is accelerated within a certain undercooling range due to the third element addition, but slowed down otherwise. When more of the third element is contained, the growth velocity is always reduced. However, the eutectic lamellar spacing varies with the content in an opposite way. The influence of the third element addition is enhanced when the difference in distribution coefficients of the third element in two eutectic phases becomes greater. [Copyright &y& Elsevier]

Abstract: The microstructural evolution of the Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glass during annealing and rolling deformation was studied. After annealing at 680K for 0.5h, phase separation is observed, and nanocrystallization is further induced by the subsequent rolling deformation. Increasing annealing time to 1.5h leads to the formation of both nanocrystals and large-size particles of the Zr–Cu fcc phase. After rolling, the volume fraction of nanocrystals increases slightly while the Zr–Cu particles disappear. The presence of phase separation and nanocrystals during annealing reduce the thermal stability of the glass and accelerate the subsequent crystallization driven by rolling. During rolling the two annealed specimens exhibit the good ductility. [Copyright &y& Elsevier]

Abstract: The mode and mechanism of the interaction of morphine chloride, an important alkaloid compound to calf thymus deoxyribonucleic acid (ct DNA) was investigated from absorption and fluorescence titration techniques. Hypochromic effect was founded in the absorption spectra of morphine when concentration of DNA increased. The decreased fluorescence study revealed non-cooperative binding of the morphine to DNA with an affinity of 3.94×103 M−1, and the stoichiometry of binding was characterized to be about one morphine molecule per nucleotide. Stern–Volmer plots at different temperatures proved that the quenching mechanism was static. Ferrocyanide quenching study showed that the magnitude of K SV of the bound morphine was lower than that of the free one. In addition, it was found that ionic strength could affect the binding of morphine and DNA. Fluorescence polarization and denatured DNA studies also applied strong evidences that morphine molecule was partially intercalated between every alternate base pairs of ct DNA. As observed from above experiments, intercalation was well supported as the binding mode of morphine and ct DNA. [Copyright &y& Elsevier]

Abstract: The microstructure and stored energy of Cu60Zr20Ti20 bulk metallic glass rolled at cryogenic temperature in a wide strain rate range 1.0×10−4 −5.0×10−1 s−1 have been investigated. As the specimen is rolled to be thinner, the stored energy first increases linearly, and then saturates above a critical thickness reduction at lower strain rates, or decreases at high strain rates. At the initial stage of rolling, no phase transformation except shear bands appears in the glass. Phase transformation occurs only when the specimen is severely deformed at strain rates higher than 1.0×10−4 s−1. As strain rate increases, the critical strain for the stored energy to saturate increases, but the critical strain for phase separation to occur decreases, and meanwhile the type of the phase transformation changes from phase separation to nanocrystallization. The stored energy does not change with the occurrence of phase separation, but decreases due to nanocrystallization. It is proposed that coalescence of more free volume in shear bands into nano-voids should be principally responsible for the saturation of the stored energy, which balances the results from the increase in shear band number at higher strains. [Copyright &y& Elsevier]

Bulk Cu47.5Zr47.5Al5 metallic glass was rolled at different strain rates and temperatures. No phase transformation occurs in the as-rolled specimens except for shear bands. Free volume monotonously increases with increasing strain, and the rate of increase becomes larger with increasing strain rate or decreasing temperature. However, after an initial rise, the microhardness drops when the strain exceeds a critical value dependent on the rolling conditions. The increase in hardness is proved to result from the interaction of shear bands. [Copyright &y& Elsevier]

Abstract: The microstructure and hardness evolutions of the as-cast and annealed Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glass during rolling deformation were studied. It is revealed that nanocrystals and new glassy phases with sizes in the range of 5–20nm form in the as-cast/rolled sample when the reduction in thickness exceeds 90%. If the glass is isothermally pre-annealed, the deformability decreases due to the precipitation of the crystalline phases. However, the samples with the fraction of crystalline phases less than 36% still possess a good ductility during rolling. The hardness of the material decreases with the rolling proceeding, and the decrease is more significant in the pre-annealed samples. [Copyright &y& Elsevier]

Abstract: The primary crystallization of Al87Ni6RE7 and Al85Ni6RE9 (RE=La, Ce, Nd and Y) amorphous alloys was investigated by X-ray diffraction and differential scanning calorimetry. With decreasing the atomic radius of RE, i.e., in an order of La>Ce>Nd>Y, the thermal stability first remains almost unchanged for RE=La and Ce, and then gradually decreases when RE changes through Nd to Y. Meanwhile, the supercooled liquid region gradually enlarges in the Al85Ni6RE9, but changes complicatedly in the Al87Ni6RE7. The primary phase consists of fcc-Al plus metastable phase(s) for RE=La and Ce in the Al87Ni6RE7 or single metastable phase for RE=La, Ce and Y in the Al85Ni6RE9, but only fcc-Al in the other alloys. Except the Al85Ni6Nd9 alloy whose primary crystallization process is interface-controlled in growth, the primary crystallization processes of the other alloys are diffusion-controlled. With increasing the content of RE, the thermal stability, supercooled liquid region and nucleation rate increase. Meanwhile, metastable phases are prone to precipitate. [Copyright &y& Elsevier]

Abstract: When a single-phase alloy solidifies in a low-undercooling range or above a critical undercooling, grain-refined structures are obtained. Taking Ni75Pd25 alloy as an example, the microscopic orientation of the refined grains was investigated by electron backscattered diffraction technology. It is revealed that the refined grains at low undercooling are completely randomly distributed. In the refined structure at high undercooling, certain grain boundaries with misorientation angles less than 5° can be observed, while most of the grain boundaries have large misorientation angles. The inverse pole figure indicates that the refined grains at high undercooling have a textured crystallographic orientation. The fact that twins exist in the refined structure at high undercooling and the dendritic substructure arms exhibit no misorientation supports such an argument that the grain refinement at high undercooling results from the recrystallization of the solidification dendrites. [Copyright &y& Elsevier]

Abstract: To clarify the corrosion mechanism associated with T1 and T2 precipitates in Al–Cu–Li alloys, the simulated bulk precipitates of T1 and T2 were fabricated through melting and casting, their electrochemical behaviors and coupling behaviors with α(Al) in NaCl solution were investigated. Meanwhile, simulated Al–Cu–Li alloys containing T1 and T2 particles, respectively, were prepared and their corrosion morphologies were observed. A corrosion conversion mechanism associated with the precipitates of T1 and T2 was advanced. The precipitates of T1 and T2 are anodic to the alloy base and corrosion occurs on their surface at the beginning. While, during their corrosion process, the preferential dissolution of Li and the enrichment of noble element Cu make their potential move to a positive direction. As a result, the corroded T1 and T2 precipitates become cathodic to the alloy base at a later stage, leading to the anodic dissolution and corrosion of the alloy base at their adjacent periphery. However, due to more amount of active element Li and much less amount of noble element Cu in the precipitate of T2, the electrode conversion of T2 from anode to cathode is more superficial than that of T1, and the corrosion mainly occurs in T2. [Copyright &y& Elsevier]

Abstract: Effects of replacing Ni by Co on the crystallization behaviors of three Al–Ni–La amorphous alloys, i.e. Al85Ni9La6, Al86Ni9La5 and Al87Ni8La5 were investigated by X-ray diffraction and differential scanning calorimeter. The results show that the glass-forming ability decreases when Ni is replaced by excessive Co. Meanwhile replacing Ni by Co improves the thermal stability, enlarges the supercooled liquid region ΔTx and promotes the precipitation of the metastable phase(s) as the primary phase. The apparent activation energy E a1 of the first reaction changes complicatedly during the replacement and is strongly dependent on the type of the primary phase, i.e. diffusion of atoms. [Copyright &y& Elsevier]

Abstract: Two bulk Ni–Pd alloys Ni75Pd25 and Ni54.8Pd45.2 have been undercooled beyond their hypercooling limits. As undercooling increases, two grain refinements, occurring at low and high undercooling, respectively, were observed in the solidification of both alloys, even though the equilibrium crystallization temperature range of the latter is only 5K. Reaching of the hypercooling limit did not change the microstructural morphology abruptly, and dendritic substructure could still be found in the refined grains. Such experimental results cannot be interpreted satisfactorily by the theory that the break-up of dendrites during solidification is dominated by capillary force. It is proposed that the grain refinement at low undercooling results from the remelting associated with chemical superheating, but that at high undercooling is due to the post-solidification recrystallization. [Copyright &y& Elsevier]

Abstract: The fluorescence properties of a newly synthesized compound, 1,5-diphenyl-3-(N-ethylcarbazole-3-yl)-2-pyrazoline (DEP) have been studied. On excitation at 352nm, the fluorescence spectrum exhibits a large red shift with an increase in the polarity of solvents. The intensity of the band is different in different solvents as well. The change in the dipole moment in various solvents at room temperature has been characterized by the absorption and steady state fluorescence techniques and calculated based on the Lippert–Mataga equation. DEP has an increase of dipole moment of 2.83D units on excitation to the lowest singlet state. It is concluded that photo-induced charge transfer from N (1) to C (3) actually exists in the excited state of the pyrazoline moiety. Its fluorescence property is relative to viscosity and temperature of solvents. The ϕ f of DEP in neutral medium or basic medium is higher than acidic medium. In addition, when the concentration of DEP is higher than 10−3 M, its fluorescence is quenched by the collision of each molecule. The red shift of the maximum emission of DEP attributes to the formation of aggregates and the conjugate system is strengthened. [Copyright &y& Elsevier]

Abstract: The dissolution and interfacial reaction of Nb in contact with the molten 52In–48Sn solder has been investigated in the temperature range 192–260°C for periods ranging up to 1 year. Intermetallic compounds (IMCs) grow at the interface between the Nb and the solder, after a latency time required for Nb to diffuse in the solder, and these have been identified by X-ray diffraction as NbSn2 hexagonal platelet crystals, with a highly preferred orientation. The crystal sizes have been found to follow a log-normal distribution and crystal growth begins first at the corners of the substrate, followed by the edges and then finally in the centre. The Nb/solder system is unusual in that the IMC growth is several orders of magnitude slower than observed in other solder–substrate systems, and the limiting size of the IMC layer actually decreases with increasing temperature. A model explaining these observations is presented where the IMC nucleation and growth are controlled by diffusion of Nb atoms in the liquid solder. Low meta-stable concentration of Nb at the interface, a critical supersaturated concentration of Nb very close to the meta-stable concentration required before the IMC can grow and negligible solid state diffusion in the IMC are identified as the key factors responsible for the observed kinetics of dissolution and interfacial reaction. [Copyright &y& Elsevier]

Abstract: Effects of La content on the glass transition and crystallization process of Al94−x Ni6La x (x =3–9) amorphous alloys were investigated by X-ray diffraction and differential scanning calorimeter. The results show that the thermal stability increases with increasing the La content. The crystallization changes from a two-stage process without glass transition at x =3–6 to a three-stage one with obvious glass transition at x =7–9. The first crystallization process results in precipitation of single fcc-Al at x =3–5, fcc-Al plus metastable phase(s) at x =6 and 7, and single metastable phase at x =8 and 9. The first crystallization process at x =4 and 5 is the growth of quenched-in nuclei, whereas that at x =6, 7 and 9 is the diffusion-controlled growth with a decreasing, constant and increasing nucleation rate, respectively. The activation energy for the first crystallization process is larger in the eutectic reaction than that in the primary reaction, and is the highest when the number of the products is the most. [Copyright &y& Elsevier]

Abstract: The phase formation and crystallization kinetics during the thermal treatment of amorphous Zr60Al15Ni25 alloy were investigated by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). By lowering the isothermal annealing temperatures, it is revealed that the crystallization of the amorphous Zr60Al15Ni25 alloy consists of a primary transformation followed by a polymorphic transformation, corresponding to the precipitations of hexagonal Zr6Al2Ni and the Zr5AlNi4 with a U3Si2-typed superstructure. The primary phase being Zr6Al2Ni rather than Zr5AlNi4 in the crystallization is because the latter has a complex structure and its formation requires the diffusion of Al and Zr atoms on a large scale. [Copyright &y& Elsevier]

Abstract: Ni54.6Pd45.4, a solid solution alloy without crystallization temperature range, has been undercooled by glass flux method up to the hypercooling limit. It was found that it solidified as pure metals. As undercooling increases, the secondary dendrite arm spacing decreases monotonously until a undercooling of 135K, above which the secondary branches considerably degenerate. The solidification with undercoolings higher than 160K leads to grain-refined structures. In this case, their average grain sizes continuously decrease with increasing undercooling even if the alloy has been hypercooled. The fact that grain refinement still takes place in the solidification of the hypercooled alloy indicates that the solidification time after recalescence is not a factor to dominate the grain refinement at large undercooling. Recrystallization of the solid in the post-solidification period should be responsible for the grain refinement. [Copyright &y& Elsevier]

Abstract: The function mechanism of different types of aging precipitates in localized corrosion of Al alloys was studied. The function mechanism of the precipitates of θ (Al2Cu) and η (MgZn2) is validated. The precipitate of θ containing noble element Cu is cathodic to the alloy base, resulting in the anodic dissolution and corrosion of the alloy base at its adjacent periphery. The precipitate of η containing active element Mg is anodic to the alloy base, anodic dissolution and corrosion occur on its surface. Meanwhile, a localized corrosion mechanism conversion associated with the precipitate of T1 (Al2CuLi) is advanced, which contains noble element Cu and active element Li simultaneously. The precipitate of T1 is anodic to the alloy base and corrosion occurs on its surface at the beginning. However, during its corrosion process, the preferential dissolution of Li and the enrichment of noble element Cu make its potential move to a positive direction. As a result, the corroded T1 precipitate becomes cathodic to the alloy base at a later stage, leading to the anodic dissolution and corrosion of the alloy base at its adjacent periphery. [Copyright &y& Elsevier]

Abstract: Mechanical strength evolutions during rolling the Cu60Zr20Ti20 bulk metallic glass (BMG) at room temperature (RT) and cryogenic temperature (CT) have been investigated by measuring the microhardness. The hardness slightly increases during the initial rolling stage as a result of the gradually enhanced microinhomogeneity of chemical composition, and then dramatically rises owing to phase separation at CT or phase separation plus nanocrystallization at RT. It is revealed that the Cu-rich separated amorphous phases from the matrix possess higher strengths than the original and Cu-poor separated amorphous phases. As the deformation-induced nanocrystallites contain lots of crystal defects, their resistance to yielding is deteriorated. Consequently, as partial phase-separated regions crystallize during RT-rolling, the increase rate of microhardness slows down as compared with that in CT-rolling. It is proposed that phase separation may be a more effective way to strengthen the BMG than the incorporation of the nanocrystallites with crystal defects. [Copyright &y& Elsevier]

Abstract: Anatase TiO2 films were prepared by micro-arc oxidation of TiN films in a Na3PO4 electrolytic solution, while TiN films were obtained by ion beam assisted deposition on Ti substrates. The crystal structure, surface morphology and optical property of the films were investigated by X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), scanning electron microscopy (SEM) and UV–vis spectroscopy, respectively. The photocatalytic activity of the films was evaluated by the decomposition of methylene blue. Mechanisms for micro-arc oxidation and band gap narrowing of N-doped TiO2 were discussed. [Copyright &y& Elsevier]

Abstract: In order to improve the photocatalytic activity, N-doped titanium oxide (TiO2) films were obtained by thermal oxidation of TiN films, which were prepared on Ti substrates by ion beam assisted deposition (IBAD). The dominating rutile TiO2 phase was found in films after thermal oxidation. According to the results of X-ray photoelectron spectroscopy (XPS), the residual N atoms occupied O-atom sites in TiO2 lattice to form Tih name="sbnd" />N bonds. UV–vis spectra revealed the N-doped TiO2 film had a red shift of absorption edge. The maximum red shift was assigned to the sample annealed at 750°C, with an onset wavelength at 600nm. The onset wavelength corresponded to the photon energy of 2.05eV, which was nearly 1.0eV below the band gap of pure rutile TiO2. The effect of nitrogen was responsible for the enhancement of photoactivity of N-doped TiO2 films in the range of visible light. [Copyright &y& Elsevier]

Abstract: A time dependence of the form t 1/n with n >3 was observed for the thickening kinetics of the Ni3Sn4 scallops formed in both the Sn–58Bi/Ni and Sn–58Bi/Ni–P systems, which can be attributed to the radial growth kinetics of the Ni3Sn4 scallops and grain boundary diffusion due to the existence of molten channels between the previously formed Ni3Sn4 scallops. Evidence is presented suggesting that highly scattered pores within the Ni3P layer play an important role in the seemingly random fluctuations of the Ni3Sn4 thickness in the Sn–58Bi/Ni–P system with respect to reaction temperature and time. By contrast, the thickness of the Ni3Sn4 layer in the Sn–58Bi/Ni system increased with increasing reaction temperature and time. Addition of 1wt.% Cu into the basic Sn–58Bi solder led to the formation of (Cu,Ni)6Sn5, instead of Ni3Sn4, and hence significantly reduced the consumption rates of both the Ni and Ni–P layers during high-temperature storage. Pure electroplated Ni will not survive appreciably longer than electroless Ni–P when in contact with either molten Sn–58Bi or Sn–Bi–Cu. [Copyright &y& Elsevier]

Abstract: A Mg–10.02Li–3.86Zn–2.54Al–1.76Cu alloy was prepared and its corrosion-resistant coating was obtained in 25g/L K2Cr2O7 +25g/L H2SO4 solution through galvanic anodizing. It is found that the alloy displays age-softening behavior. The micro-hardness of the quenched alloy increases with quenching temperature, which is caused by increased solution degree of Mg and Al in β phase. Its tensile strength increases as quenching temperature increases to 250°C, due to the same reason. However, further temperature increase leads to the coarsening of β phase grains and a decrease in the tensile strength. The coating thickness increases with pH value decrease and operating temperature increase, while its corrosion resistance decreases. The results show that coatings obtained at room temperature with pH 4.5 and (or) pH 5.5 possess better corrosion resistance. [Copyright &y& Elsevier]

Abstract: Nanocrystalline titania films on titanium substrate were prepared by micro-arc oxidation in an electrolytic solution containing Na3PO4 and NaF. The process was carried out at high voltages and currents using a DC power supply. The crystal structure, chemical composition, surface morphology and optical property of the films were investigated by X-ray diffraction, X-ray fluorescence spectroscopy, scanning electron microscopy and UV–VIS spectroscopy, respectively. The photocatalytic activity of the films was evaluated by the decomposition of methylene blue. The relation between the concentration of NaF in the electrolyte and the property of the titania films was also discussed in the paper. [Copyright &y& Elsevier]

Abstract: Bulk Cu60Zr20Ti20 metallic glass has been rolled at room temperature (RT) and cryogenic temperature (CT) up to 97% in thickness reduction, and the dependences of microstructure on the strain and temperature have been investigated. It is revealed that as the deformation proceeds below a critical thickness reduction, which is 87% at RT and 89% at CT, only the shear band density and the free-volume content increase, whereas the thermal stability of the deformed glass remains unchanged. Deformation above the critical thickness reduction results in phase separation plus nanocrystallization at RT, but only phase separation at CT, indicating that lowering the temperature can effectively retard the deformation-driven crystallization, and that phase separation is the precursor of crystallization. The appearances of phase separation and especially nanocrystallization reduce the thermal stability of the glass since they create advantages in chemical composition and topological structure for the primary crystalline phase to nucleate and grow. [Copyright &y& Elsevier]

Abstract: This paper reports on the interfacial reaction kinetics between molten Sn–58Bi solder and Cu substrates for extended temporal scales. Also studied are the effects of a series of elemental additions of 1–2wt.% Al, Cr, Cu, Si, Zn, Ag, Au, Pt and Nb into the basic Sn–58Bi solder, in an attempt to produce a barrier layer that slows down intermetallic compound (IMC) growth. At temperatures between 200 and 240°C, grain boundary-/molten channel-controlled growth of η-phase (Cu6Sn5), followed by diffusion-controlled simultaneous growth of the ε-phase (Cu3Sn) and η-phase (Cu6Sn5), between the molten Sn–58Bi solder and the Cu substrate was observed, and a layer of 6μm Cu could survive for approximately 24–48h. Addition of 1wt.% Zn resulted in a layer of γ-Cu5Zn8, instead of Cu3Sn and Cu6Sn5, forming at the interface, leading to an increase in the lifetime of the Cu substrate to greater than 120h at 200°C, while the other additions failed to slow down IMC formation. [Copyright &y& Elsevier]