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Ni 77 Ga 23 alloys were undercooled and rapidly solidified using glass fluxing treatment. An in situ diagnosis of dendrite growth velocity during rapid solidification processing suggests crystallization of a disordered solid solution from low to high undercoolings. While this diagnosis is consistent with an X-ray diffraction analysis, a neutron diffraction analysis suggests the formation of Ni 3 Ga phase in addition to the disordered solid solution. An EBSD analysis shows the formation of an equiaxed microstructure at a high undercooling. A HAADF-STEM study of equiaxed grains reveals a superalloy-like substructure, where cuboidal coherent precipitates of Ni 3 Ga phase are dispersed in the matrix of the disordered solid solution. A HRTEM study further reveals disordered nanodomains in the lattice of Ni 3 Ga phase. It is concluded that rapid solidification processing can lead to facile formation of a superalloy-like microstructure without an aging treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

Crystal structure, magnetoelastic coupling, magnetization and magnetocaloric effects of Mn3SnC0.94 and Mn3SnC0.81 were investigated. Temperature-dependent high-resolution X-ray diffraction measurements showed that a larger carbon deficiency of Mn3SnC0.81 reduces lattice distortions more significantly than it reduces the lattice parameter. Resonant ultrasound spectroscopy measurements showed that the larger carbon deficiency has no effect on the lattice stiffening across a ferromagnetic transition, whereas it reduces the lattice softening across a low-temperature transition. Magnetic measurements showed that the larger carbon deficiency doubles high-field magnetization and improves the refrigeration capacity. It is suggested that the larger carbon deficiency of Mn3SnC0.81 weakens antiferromagnetic interactions more significantly than it enhances ferromagnetic interactions. However, the magnetocaloric effect of each sample includes a contribution from the lattice entropy change, which is not sensitive to the carbon deficiency. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Tip velocities of Pd dendrites under static magnetic fields were measured. • The data showed depressions and a recovery of tip velocities by the magnetic fields. • The data fully verified effects of TEMHD flows on tip velocities. • Observations of the effects agreed with recent numerical simulations. Abstract Magnetohydrodynamic flows can be driven by Lorentz forces acting on thermoelectric currents. Their effects on tip velocities of Pd dendrites solidifying from an undercooled melt under magnetic field intensities of up to 6 T were investigated by in-situ observations using a high-speed camera. At low undercoolings, the tip velocities are depressed by magnetic fields of low and high intensities, but recover under an intermediate magnetic field intensity. At high undercoolings, the tip velocities are also depressed, but their recovery is shifted to a higher magnetic field intensity. These observations on Pd dendrites support and extend the findings obtained in previous studies on Ni and Fe dendrites, and fully verify the convection effects on dendritic growth due to three thermoelectric magnetohydrodynamic flow patterns as predicted in recent numerical simulations. [ABSTRACT FROM AUTHOR]

Undercooling of Cu-based alloys often induces metastable liquid phase separation followed by rapid solidification of separated liquids. The rapid solidification can help freeze in the morphology of a higher-melting liquid and eases difficulties in studies of liquid phase separation kinetics. In the present work, the influence of static magnetic fields on liquid phase separation in bulk Cu84Co16 composition was investigated. Inductively melted samples were glass-fluxed, undercooled and solidified under uniform and non-uniform magnetic fields generated by a superconducting magnet. Solidification microstructure of the phase-separated samples was examined using an optical microscope. The imposition of the magnetic fields, both uniform and non-uniform, altered the morphology, segregation pattern and size distribution of Co-rich droplets due to liquid phase separation. The imposition of the non-uniform magnetic fields with positive and negative gradients brought about segregation of the Co-rich droplets at the top and the bottom side of the samples, respectively. Such influence of the static magnetic fields is interpreted by assuming intensification of convective flow and Kelvin force-controlled migration of the Co-rich droplets. This article is part of the theme issue 'Heterogeneous materials: metastable and non-ergodic internal structures'. [ABSTRACT FROM AUTHOR]

This paper reports a comparative study of the magnetization, magnetocaloric effects, and crystal lattices of an as-cast sample and an annealed sample of the CoMnSi compound. Magnetic measurements showed that the annealed sample has high magnetization and a doubled maximum magnetic entropy change with respect to the as-cast sample. X-ray diffraction studies determined that both samples crystallize into an orthorhombic lattice. However, there are remarkable differences in the lattice parameters and one of the nearest Mn–Mn distances between the samples. Spectroscopic measurements of the X-ray absorption near-edge structure revealed that Co–Si bonds of the annealed sample are shorter than those of the as-cast sample due to stronger ${p}$ – ${d}$ hybridization of Co and Si atoms, while other chemical bonds do not show any difference. It is concluded that high-temperature annealing enhances ferromagnetic interactions in the lattice of CoMnSi by chemical ordering of Co atoms. [ABSTRACT FROM AUTHOR]

Four novel metal-free organic dyes (CFB1, CFB2, CFT1 and CFT2) based on indeno[2,1-b]carbazole donors were synthesized and their absorption spectra, photovoltaic performances, and electrochemical properties were evaluated. The differences in linking mode and the number of thiophene units led to variations in absorptivity, electron injection efficiency, and charge recombination. Among the four dyes, CFT1 with a π-bridge at the indeno[2,1-b]carbazole ring and a bridge of thiophene showed the best photovoltaic performance with a JSC of 12.34 mA cm−2, VOC of 0.71 V, and FF of 0.68, corresponding to an overall conversion efficiency η of 5.97% under standard AM 1.5 G irradiation. [ABSTRACT FROM AUTHOR]

Metastable solidification of undercooled Co 60 Si 40 melts was investigated by microstructural studies and in-situ high-energy X-ray diffraction. Five solidification paths were identified. Three of them were observed at low undercoolings, which show uncoupled and coupled growth of stable β-Co 2 Si and CoSi compounds. The other paths were observed at high undercoolings, which show peritectic and primary crystallization of a metastable Co 5 Si 3 compound. The β-Co 2 Si and Co 5 Si 3 compounds crystallize into a hexagonal crystal structure and experience solid-state decomposition. Microstructure formation depends on solidification path. The coupled and uncoupled growth of the stable compounds produces a regular lamellar eutectic structure and an anomalous eutectic structure, respectively. The crystallization and solid-state decomposition of the metastable Co 5 Si 3 compound brings about a fine-grained two-phase mixture, which represents another type of anomalous eutectic structure. The results provide proof of two rare mechanisms of anomalous eutectic formation and shed light onto metastable phase relations in the undercooled region of the Co Si system. [ABSTRACT FROM AUTHOR]

Dendritic growth velocities of pure Fe under static magnetic fields of intensity ranging from B = 0 T to B = 6 T were measured using a high speed camera. The data measured at undercoolings up to Δ T = 190 K show a depression followed by a recovery of the growth velocities as the magnetic field intensity increased from a low range, B = 1–3 T to a high range, B = 4–6 T. These magnetic field effects are similar to those previously observed for pure Ni and can be attributed to competing thermoelectric magnetohydrodynamic (TEMHD) convection patterns in the local liquid. The experimental measurements for the two metals were modelled using a three-dimensional dendritic growth theory taking into account convection to estimate the effective flow velocities in the tip growth direction. The calculated effective flow velocities identify two undercooling dependences and a distinct type of magnetic field intensity dependence in common for the two metals. In comparison, the calculated effective flow velocities for pure Fe are generally smaller in magnitude. This difference between the two metals can be related to their differences in material-dependent properties as is revealed by a simple model proposed for a transverse TEMHD flow. [ABSTRACT FROM AUTHOR]

Melt flow is often quoted as the reason for a discrepancy between experiment and theory on dendritic growth kinetics at low undercoolings. But this flow effect is not justified for glass-fluxed melts where the flow field is weaker. In the present work, we modeled the thermal history, flow pattern and dendritic structure of a glass-fluxed nickel sample by magnetohydrodynamics calculations. First, the temperature distribution and flow structure in the molten and undercooled melt were simulated by reproducing the observed thermal history of the sample prior to solidification. Then the dendritic structure and surface temperature of the recalescing sample were simulated. These simulations revealed a large thermal gradient crossing the sample, which led to an underestimation of the real undercooling for dendritic growth in the bulk volume of the sample. By accounting for this underestimation, we recalculated the dendritic tip velocities in the glass-fluxed nickel melt using a theory of three-dimensional dendritic growth with convection and concluded an improved agreement between experiment and theory. [ABSTRACT FROM AUTHOR]

3-Heterocyclic coumarins were prepared in one-pot three-component reaction without catalyst. The mixture of salicylaldehydes, ethyl cyanoacetate, and o-aminophenols or o-phenylenediamines in refluxing n-butanol gave title compounds with good yields and high purity. Short reaction time, mild reaction condition, simple workup, and less waste are significant advantages of the presented method. [ABSTRACT FROM AUTHOR]

Dendritic growth velocities in an undercooled melt of pure nickel under static magnetic fields up to 6 T were measured using a high-speed camera. The growth velocities for undercoolings below 120 K are depressed under low magnetic fields, but are recovered progressively under high magnetic fields. This retrograde behavior arises from two competing kinds of magnetohydrodynamics in the melt and becomes indistinguishable for higher undercoolings. The measured data is used for testing of a recent theory of dendritic growth with convection. A reasonable agreement is attained by assuming magnetic field-dependent flow velocities. As is shown, the theory can also account for previous data of dendritic growth kinetics in pure succinonitrile under normal gravity and microgravity conditions. These tests demonstrate the efficiency of the theory which provides a realistic description of dendritic growth kinetics of pure substances with convection. [ABSTRACT FROM AUTHOR]

A class of novel carbazole sensitizers was synthesized with carbazole derivatives as the electron donor, 4-phenyl-2-(thiophen-2-yl) thiazole as π-bridge and cyanoacetic acid as the electron acceptor. Their absorption spectra, photovoltaic performance and electrochemical properties were evaluated. These carbazole sensitizers share the same π-bridge and electron acceptor and display the similar absorption spectra. However, the differences in link mode and substituent bring about the absorptivity variation. It is observed that the link mode of π-bridge at the benzene ring instead of N atom of the carbazole unit favors improving the light absorptivity and lowering the charge recombination. Those carbazole sensitizers show the optimal photovoltaic performance with a J sc of 10.01 mA/cm 2 , V oc of 0.66 V, and ff of 0.72, corresponding to an overall conversion efficiency η of 4.72% under standard AM 1.5G irradiation. [ABSTRACT FROM AUTHOR]

Coumarin unit is introduced into triarylamine and three organic sensitizers are designed and synthesized with triarylamine bearing coumarin moiety as the electron donor, conjugated system containing thiophene unit as the π-bridge, and cyanoacetic acid moiety as the electron acceptor. The light-harvesting capabilities and photovoltaic performance of these dyes are investigated systematically with the comparison of different π-bridges. High molar extinction coefficients are observed in these triarylamine dyes and the photocurrent and photovoltage are increased with the introduction of another thiophene or benzene. Optimal photovoltaic performance ( η = 6.24%, V oc = 690 mV, J sc = 14.33 mA cm −2 , and ff = 0.63) is observed in the DSSC based on dye with thiophene-phenyl unit as the π-conjugated bridge under 100 mW cm −2 simulated AM 1.5 G solar irradiation. [ABSTRACT FROM AUTHOR]

Free eutectic growth and its competition with single-phase growth in solidification of undercooled near-eutectic alloys are not yet fully understood. In this paper, the historical development of eutectic growth models was reviewed. The LZ model of free eutectic growth was evaluated using recent data of eutectic growth velocities in an undercooled Ni81.3Sn18.7 eutectic composition. An excellent agreement was achieved between the LZ model and the data. Crystal growth velocities in off-eutectic Ni83Sn17 and Ni80Sn20 compositions were measured using a high-speed camera technique. The present data of the off-eutectic compositions and the recent data of the eutectic composition were modeled using the LZ model and the LKT/BCT model of free dendritic growth. The modeling revealed that the competition between the free eutectic growth and the single-phase growth is controlled by the highest interface temperature criterion. A coupled zone of the α-Ni-Ni3Sn eutectic was calculated using this criterion. The coupled zone agrees well with studies of solidified structures of undercooled samples. [ABSTRACT FROM AUTHOR]

The size distribution and composition of Co-rich particles in phase-separated Cu75Co25 alloys under magnetic fields of up to 4T were investigated. The results indicate that forced convective flow is suppressed effectively under a suitable magnetic field, whereas the thermoelectric magnetic convection under a high magnetic field cannot be neglected. The diffusive growth of Co-rich particle has a strong relation with the undercooling and a weak dependence on the magnetic field. The magnetic field does not alter the asynchronous crystallization behavior of Co-rich particles. [ABSTRACT FROM AUTHOR]

Abstract: Melts of the intermetallic compound Ni3Sn were undercooled using the glass fluxing technique with and without imposition of a static magnetic field of 1T. Dendritic growth velocities in the undercooled melts were measured by in-situ monitoring of the recalescence process with a high-speed camera. The measured growth velocities show an abrupt increase at a critical undercooling of 190K independent of the magnetic field. This observation presents evidence for complete disorder trapping in the Ni3Sn compound. The imposition of the magnetic field lowers the growth velocities for undercoolings below 190K, but it does not alter the growth velocities for higher undercoolings. This impeding effect of the magnetic field can be explained within the framework of the current theory on dendritic growth by considering damped thermal transport in the undercooled melts. [Copyright &y& Elsevier]

The growth dynamics of a three-phase eutectic during solidification of a Zn−3Mg−4Al (wt.%) alloy was investigated using synchrotron X-radiography. It was observed in situ that the three-phase eutectic grows with a macrofaceted morphology after nucleating on primary Mg 2 Zn 11. The facets of the three-phase eutectic are due to the leading growth of Mg 2 Zn 11. Density functional theory based calculations confirm that this leading phase has a highly anisotropic equilibrium shape. It was also observed that the eutectic−liquid interface destabilizes in solidification, generating macrosteps into the constitutionally undercooled liquid. The onset of the interfacial instability may have an orientation dependence due to the crystalline anisotropy of Mg 2 Zn 11. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • The Ge substitution for 50% Sn enlarges the magnetovolume effect in Mn 3 SnC. • The Ge substitution increases high field magnetization at Curie temperature. • The Ge substitution reduces the magnetocaloric effect. • The Ge substitution perhaps causes a change of the electronic structure. The effects of a Ge substitution for 50% Sn on the crystal structure, magnetization and the magnetocaloric effect of Mn 3 SnC were investigated using high-resolution X-ray diffraction, magnetic and calorimetric measurements. Results show that the Ge substitution enlarges the magnetovolume effect, though it reduces the lattice parameter. On the other hand, the Ge substitution increases high field magnetization and reduces the Curie temperature. The Ge substitution also reduces latent heat during the ferrimagnetic transition and the magnetocaloric effect at the magnetic field change 0–5 T. It is suggested that the Ge substitution perhaps reduces the electronic entropy change via a change of the electronic structure and its stability against an external magnetic field. This effect is dominant over an increase of the magnetic entropy change leading to the reduction of the magnetocaloric effect. [ABSTRACT FROM AUTHOR]

Abstract: A novel class of phosphorous–nitrogen containing quaternary ammonium salts (PNQAS) were synthesized and used as modifiers for sodium montmorillonite (Na-MMT). Montmorillonites modified by PNQAS (PNQAS-MMT) were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), dispersibility measurement and thermogravimetric analysis (TGA). The results show that the PNQAS have been intercalated into the montmorillonite layers successfully and the basal spacing of PNQAS-MMT is 1.70–2.65nm. The XRD results show that the basal spacing of PNQAS-MMT reaches a maximum when PNQAS/CEC molar ratio is above 1.2. The increase of chain length of PNQAS is beneficial to expand the interlayer space of the MMT. The TEM and dispersibility measurement results show that PNQAS-MMT have stronger hydrophobicity and better dispersion than Na-MMT. The TGA results reveal that the thermal stability for PNQAS-MMT is affected by the structure and composition of intercalated PNQAS cations. The T inital of PNQAS-MMT is between 286°C and 385°C, which can be applied to the modification of the polymer as a halogen-free flame retardant. [Copyright &y& Elsevier]

Phase relations and microstructure of LaFe13-xSix alloys (x= 0.5 to 3.0) were investigated. In induction-melted alloys, α-(Fe,Si) and LaFe2Si2 crystallized primarily in sequence of increasing x. In arc-melted alloys, α-(Fe,Si) and the tetragonal La(Fe,Si)13 compound crystallized primarily instead. The cubic La(Fe,Si)13 compound was found to crystallize as a peritectic phase following primary α-(Fe,Si) formation in some of the alloys. The results were discussed with respect to phase formation during rapid solidification of the La(Fe,Si)13 material for magnetic refrigeration. [ABSTRACT FROM AUTHOR]

Abstract: Mesoporous MCM-41 silica functionalized with sulfonic acid groups (SO3H-MCM-41) was prepared through the condensation of MCM-41 with benzyl alcohol followed with sulfonation, which was characterized by XRD, FT-IR and nitrogen adsorption analyses. One-pot Fischer indole synthesis of tryptophols under the catalysis of SO3H-MCM-41 was reported with phenylhydrazine hydrochlorides and 2,3-dihydrofuran. The acidity and amount of sulfur loading were surveyed and also were the catalytic performance of SO3H-MCM-41. The results showed that higher amount of sulfur loading leads to higher acidity and consequently better yields of tryptophols. Moreover, SO3H-MCM-41 displayed good shape-selectivity in Fischer indole synthesis and inhibited the production of bulky byproduct polyindoles which were generally found in traditional acid catalysis. A series of tryptophols were synthesized with SO3H-MCM-41 in better yields than those of conventional methods reported. [Copyright &y& Elsevier]

Abstract: The 2-(2-(5,5-dimethyl-1,3,2-dioxaphosphinyl-2-ylamino)ethy-amino)-N,N,N-triethyl-2-oxoethanaminium chloride (compound c ) containing phosphorus–nitrogen structure was synthesized and characterized. A novel intumescent flame retardant, namely montmorillonite (MMT) by modified with compound c ( c -MMT), was prepared by ion exchanging of the nanometer Na+-montmorillonite (Na-MMT) with compound c . Both FTIR and X-ray diffraction (XRD) indicated that compound c had intercalated with Na-MMT and exfoliated c -MMT/PU nanocomposites have obtained by in-situ polymerization. TEM results further support the formation of the exfoliated nanocomposites. The thermal stability and flammability of c -MMT/PU composites were investigated by thermogravimetric analysis (TGA) and cone calorimeter test respectively. The results showed that the addition of flame retardant c -MMT enhanced the thermal stability and flame retardancy of PU significantly. SEM results indicated that c -MMT can achieve better dispersion in the chars after combustion and the compact and dense intumescent char is formed for c -MMT/PU composites after combustion. It is found that the char structure plays an important role for c -MMT in PU resin. The thermal stability and flame retardancy of PU resin were also significantly improved by an addition of c -MMT in PU resin. [Copyright &y& Elsevier]

Electromagnetically levitated Cu–Cr alloy melts containing 5–70 at.% Cr were splat-quenched onto a chill substrate. The microstructure of the solidified alloys was investigated by scanning electron microscopy. The alloys containing 5–60 at.% Cr showed a droplet-shaped microstructure consisting of Cr-rich spheroids or and dendrites in a Cu-rich matrix, whereas those containing 65 and 70 at.% Cr showed a banded microstructure consisting of alternative Cu-rich and Cr-rich bands. Both types of microstructure presented evidence for metastable phase separation in Cu–Cr alloy compositions, thus verifying the existence of a broad miscibility gap in the undercooled liquid. However, the results suggested that the miscibility gap has a Cr-rich critical composition and a skewed geometry. [ABSTRACT FROM AUTHOR]

Abstract: Six D–π–A–π–D anthracenedione derivatives were synthesized and characterized by UV, IR, 1H NMR and elemental analysis. The third-order nonlinear optical properties of the compounds were measured using femtosecond degenerate four-wave mixing. The third-order nonlinear optical susceptibilities χ (3) of the compounds were 2.64–3.83×10−13 esu. The second-order hyperpolarizabilities γ of the molecules were 2.86–3.84×10−31 esu. The response times were 86–108fs. [Copyright &y& Elsevier]

Abstract: We synthesized four symmetrical benzodifuranone compounds. Their structures were confirmed by UV, IR, 1H NMR and elemental analysis. The off-resonant third-order nonlinear optical properties of the compounds were investigated via femtosecond time-resolved degenerate four-wave mixing technique with 80fs pulse width at 800nm. The third-order nonlinear optical susceptibilities X (3) were 2.86–3.21×10−13 esu. The nonlinear refractive index n 2 were 5.26–5.91×10−12 esu. The second-order hyperpolarizabilities γ of the molecules were 2.92–3.42×10−31 esu. The response times were 88–91fs. These results show that symmetrical benzodifuranone compounds have potential nonlinear optical applications. [Copyright &y& Elsevier]

Eutectic colony formation in near-eutectic alloys is often attributed to independent nucleation of eutectic grains on the surface of primary dendrites. In this paper, we report an in-situ study of eutectic solidification in hypoeutectic Zn–Al alloys using synchrotron X-radiography. While the α-Al/η-Zn eutectic is observed to grow from a single nucleus in the interdendritic liquid, a cellular instability at the eutectic front is observed for the first time. The cellular instability is induced by an impurity dissolved in the liquid, while a flow effect is negligible. This observation confirms an alternative mechanism of eutectic colony formation. [ABSTRACT FROM AUTHOR]

• Tip velocities of undercooled Ti dendrites were modeled using a theory. • A forced flow effect on tip velocities is significant only at low undercoolings. • An oxygen impurity effect on tip velocities is evident at low and high undercooling. • The modeling reconciled discrepancies in literature data. Tip velocities of undercooled dendrites in electromagnetically levitated melt droplets of pure Ti were modeled using a theory on three-dimensional dendritic growth with fluid flow and a dilute solute. The modeling shows that a forced flow due to electromagnetic stirring depresses tip velocities of the dendrites at low undercoolings and that its effect becomes negligible at high undercoolings. In contrast, an oxygen impurity dissolved in liquid Ti depresses tip velocities of the dendrites over a broad range of undercooling while it coarsens tip radii. Such modeling results allowed for reconciliation of discrepancies in literature data by considering an oxygen impurity effect. The modeling also predicts that the effect of the oxygen impurity becomes insignificant when its concentration is reduced below 50 ppm in atomic fraction. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Abstract: Nanocomposites based on poly(vinyl alcohol) (PVA) and graphene nanosheets have been prepared by polymer solution blending and their flame retardant properties have been evaluated by a cone calorimetry test. It has been shown that there is a strong influence of graphene nanosheets on the fire behaviour of the composites with a significant reduction in peak heat release rate (PHRR) and a much longer time to ignition. Compared to pure PVA, the PHRR of PVA filled with 3wt.% graphene is reduced by 49%. The flame retardancy of graphene for PVA matrix surpasses that of both Na-MMT and MWNTs with the same addition content. Such a remarkable behaviour might be explained by the forming of a compact, dense and uniform char during combustion. [Copyright &y& Elsevier]

Crystal structure and magnetic properties of the quaternary Gd 4 Nd 1 Si 2 Ge 2 compound were investigated using synchrotron X-ray diffraction and magnetic measurements. The compound crystallized into an orthorhombic structure in the temperature range 200–300 K. In zero field cooling, the compound undergoes a spin reorientation following a ferromagnetic-like transition at 276 K. The spin reorientation is hinted at by nonlinear changes of lattice parameters but is suppressed in a high magnetic field of 6 T. Magnetic measurements revealed a magnetocaloric effect with a high relative cooling power. It is suggested that Nd substitution for Gd enlarges magnetic anisotropy and induces a canted spin structure. Image 1 • The compound shows a ferrimagnetic transition. • The compound shows a spin reorientation transition. • The compound shows forced magnetostriction. • The compound forms a canted spin structure. • The compound shows an improved and broadened magnetocaloric effect. [ABSTRACT FROM AUTHOR]

Crystal structure and magnetic properties of Gd 5 Si 1.5 Ge 2.5 and Gd 4.9 Zr 0·1 Si 1.5 Ge 2.5 were investigated using high-energy X-ray diffraction and magnetic measurements. Results showed that a Zr substitution for 2% Gd reduces unit cell volumes of a room-temperature monoclinic and a low-temperature orthorhombic lattice and a difference between them at a magnetostructural transition. At a microscopic level, the Zr substitution increases length of disconnected interlayer T–T bonds of the monoclinic lattice at the expense of length of connected interlayer T–T bonds (T = Si, Ge). These opposing changes of the interlayer T–T bonds provided evidence for existence of a short-range chemical order of Ge atoms in lattices of Gd 5 Si 1.5 Ge 2.5 and its weakening by the Zr substitution. Magnetic measurements revealed that the Zr substitution brings about a change of the magnetic structure and a reduction of a giant magnetocaloric effect of Gd 5 Si 1.5 Ge 2.5. Based on such structural and magnetic changes due to the Zr substitution, we propose a relation between the short-range chemical order and the total entropy change at the magnetostructural transition. Using this relation, a giant magnetocaloric effect and an annealing effect observed over a wide range of Gd 5 (Si,Ge) 4 composition can be explained quantitatively. Image 1 • A minor Zr substitution for Gd brings about signifiscant lattice contraction. • Opposing changes of interlayer Ge–Ge bond length provide proofs of a chemical order. • Zr substitution reduces a magnetocaloric effect at a magnetostructural transition. • A structural entropy change is related to a change of the population of Ge–Ge bonds. • Giant magnetocaloric effects of Gd 5 (Si,Ge) 4 are explained quantitatively. [ABSTRACT FROM AUTHOR]

Dengue has been a serious public health burden and dengue virus-1 (DENV-1) is the predominant strain in Guangdong province, China. Differences exist in the transmission dynamics among Aedes albopictus and DENV in different geographical regions. However, little is known about the vector competence of indigenous Aedes albopictus for the predominant dengue strain in Guangdong province, China. In this study, the field-derived Aedes albopictus collected from Guangzhou city, Guangdong province were infected with the predominant DENV endemic strain DENV-1 GZ201401 by feeding on serially diluted artificial infectious blood or infected suckling mice. DENV-infected mosquitoes were evaluated for viral load at five-time intervals in three tissues, the head, body and legs using reverse transcription-quantitative PCR (RT-qPCR). The vertical transmission of DENV in Ades albopictus was also analysed. Suckling mice were used to assess the transmission of DENV by Aedes albopictus. There was no difference in infection rates between mosquitoes infected by infected suckling mice or by artificial infectious blood. The proportion of DENV-1 positive mosquitoes increased over time after an infectious blood meal, but there was no difference in the positive rate beyond 7days after the blood meal. The positive rate of DENV-1 infected mosquitoes increased with the DENV titer in the blood meal. Most of the infections the infected mosquitoes were disseminated more than 7 days after imbibing the artificial infectious blood. The median infective doses (MID50) at 7,14,21 and 28 days after artificial infectious blood meal [7, 14, 21 and 28 days post-infection (dpi)] were 7.86 × 107, 1.57 × 107, 6.39 × 106 and 4.96 × 106 TCID 50 (50% tissue culture infective dose)/ml, respectively. The mosquitoes can spread DENV-1 GZ201401 to hosts as early as 3 dpi. The vertical transmission of DENV-1 was documented with a cumulative rate of 17.61%. Our results demonstrated that Aedes albopictus mosquitoes are competent vectors for DENV-1, and are capable of maintaining autochthonous dengue outbreaks in Guangdong province, China, which may have been promoted by vertical transmission. [ABSTRACT FROM AUTHOR]

Presents a study which melted and solidified neodymium[sub15]iron[sub77.5]boron[sub7.5] alloys using the electromagnetic levitation technique. Experimental details; Results and discussion; Conclusion.

Electromagnetic levitation was used to melt and solidify containerlessly Nd-Fe-B alloys. A method was developed to reduce and evaporate stable solid Nd oxides at the surface of the liquid samples. The oxides otherwise limit the undercoolability of the highly reactive Nd-based alloys. In such a way, undercoolings up to 150 K of the levitation processed samples were achieved. Owing to the large undercooling range, the intermetallic Nd[sub 2]Fe[sub 14]B[sub 1] phase with the hard magnetic properties was primarily crystallized at undercoolings exceeding 50 K. Solidification of the pro-peritectic γ-Fe with soft magnetic properties was successfully suppressed. At the largest undercoolings, a metastable phase, likely to be of the composition Nd[sub 2]Fe[sub 17]B[sub x] (x≈l) is primarily formed while the crystallization of Nd[sub 2]Fe[sub l4]B[sub 1] phase is followed up in a subsequent step. [ABSTRACT FROM AUTHOR]

Anomalous eutectic formation in undercooled Ni–Sn alloys was investigated by in situ X-ray diffraction and ex situ remelting and annealing experiments. Dynamic recrystallization and partial remelting of primary solids followed by repeated nucleation and growth of eutectic grains in the mushy zone were revealed by time-resolved X-ray diffraction. Ex situ experiments demonstrated that partial remelting of near-equilibrium solidified alloys of eutectic or near-eutectic composition can convert regular lamellar eutectic into anomalous eutectic, whereas high-temperature annealing of splat-quenched alloys of similar composition can convert eutectic or two-phase dendrites into anomalous eutectic. It is concluded that compared to ripening in solid-states, partial remelting of eutectic or two-phase dendrites in a mushy zone provides a more realistic mechanism for anomalous eutectic formation in undercooled solidification of Ni–Sn eutectic alloys. Image, graphical abstract [ABSTRACT FROM AUTHOR]

The novel poly(hydroxy-p-phenylenebenzobisoxazole) (HPBO) was synthesized by different polymerization routes, including hydroxy-orderly distributed polymer ( ord -HPBO) and hydroxy-randomly distributed polymer ( ran -HPBO). Surface elemental composition, thermal stability, intrinsic viscosity, UV resistance, surface morphology, mechanical and interfacial properties of HPBO fiber were investigated. ATR-FTIR and EDS spectrums identify the formation of mono-hydroxyl modified polymer. Excellent thermal stability (up to 600 °C), mechanical properties (tensile strength of 4.32 GPa, modulus of 169.7 GPa) and rheological spinnability of ran-HPBO-AS via HD self-polymerization route were obtained. Meanwhile, the SEM after UV irradiation indicated that the photostability of HPBO is better than PBO. The interfacial shear strength (IFSS) between HPBO-AS fiber and epoxy resin is 21.7 MPa, 87.1% higher than that of PBO-AS fiber. Comparing different HPBO synthesis routes, the self-polymerization of HD salt route is believed to be a feasible route for industrial production and the ran-HPBO is expected to become a new generation of high-performance fiber. [ABSTRACT FROM AUTHOR]

Three D–D–π-A triphenylamine–coumarin sensitizers were designed and synthesized with a triphenylamine and coumarin double donor and a cyanoacrylic acid acceptor. Thiophene, bithiophene and phenylthiophene were used as π-bridges, respectively, and the effects of different π-bridges on the photophysical properties and photovoltaic performance were investigated. With the incorporation of an additional thiophene unit, the bithiophene π-bridge contributes to better light absorption and hence superior JSC compared with the thiophene π-bridge. Although the dye with phenylthiophene π-bridge exhibits an inferior absorption spectrum to that with the thiophene π-bridge, it gives a photoelectrical conversion efficiency of 4.99% and exhibits the best photovoltaic performance of the three sensitizers, ascribed to its efficient photon-to-current conversion efficiency, slow charge recombination rate and good electron injection efficiency. [ABSTRACT FROM AUTHOR]

A series of third-order nonlinear optical chromophores containing identical π -bridge and electron-donating groups, but with different electron-withdrawing groups have been designed and synthesized. The ultraviolet absorption, density functional theory calculations, and the third-order nonlinear optical (NLO) properties of these materials have been investigated and systematically studied. A theoretical study showed that the third-order NLO properties were enhanced by the increasing electron-withdrawing ability in accordance with the decreasing energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital. The transferred charge to the substituent is increased and the affect on the electronic reallocation is reinforced with the increasing ability of the compounds to attract electrons. The third-order NLO susceptibilities, the second-order hyperpolarizabilities and response times of compounds were 2.829–6.034 × 10 −13 esu, 0.737–2.005 × 10 −31 esu, 41.92–68.71 fs Our results can be used to develop an efficient design strategy for NLO materials. [ABSTRACT FROM AUTHOR]

Herein we reported the preparation of a new type of ferrocene-based compounds with large conjugated system containing symmetrical aromatic vinyl and Schiff base moieties and the study of their third-order nonlinear optical (NLO) properties. Their third-order NLO properties were measured using femtosecond laser and degenerate four-wave mixing (DFWM) technique. The obtained χ (3) , n 2 and γ values of these molecules were found in the range of 0.998–1.429 × 10 −12 esu,1.847–2.646 × 10 −11 esu and 1.026–1.449 × 10 −30 esu, respectively. The response time ranged from 43.65 fs to 61.71 fs. The results indicate that these compounds have potential nonlinear optical applications. [ABSTRACT FROM AUTHOR]

Background: Preeclampsia (PE) is a multi-system disorder of pregnancy that poses a serious threat to maternal and perinatal health worldwide. This study aims to evaluate the global alterations of protein expression and N-glycosylations that are crucial for PE pathogenesis. Here, tandem mass tag labeling combined with LC-MS/MS was employed to determine the global expression of all proteins and intact glycopeptide in placentas from three healthy pregnant women, three patients with early-onset severe PE, and three patients with late-onset severe PE. Results: A total of 2260 proteins were quantified across 9 placental tissues, of which 37 and 23 were differentially expressed in the early-onset and late-onset PE groups, compared to the controls. A total of 789 glycopeptides were accurately quantified, which were derived from 204 glycosylated sites in 159 glycoproteins and were modified by 59 N-Linked glycans. A total of 123 differently expressed glycopeptides, which were from 47 glycoproteins were identified among three groups. Through a combined analysis of proteomic and glycoproteomic data, it was found that the changes in 10 glycoproteins were caused by the difference in glycosylation level but not in the protein abundance level. Conclusion: This is the first study to conduct an integrated proteomic and glycoproteomic characterization of placental tissues of PE patients. Our findings suggest that glycosylation modification may affect the molecular function of proteins through changes in the glycosylation structure or the occupancy of glycosylation, which will provide new insights to help elucidating the pathogenic mechanism of PE. [ABSTRACT FROM AUTHOR]

Magnetoresistance (MR) and Hall resistivity of TbCo2 and DyCo2 with a Co Kagome lattice were investigated. Apart from giant negative magnetoresistance (MR) at TC, plateau-like MR and a topological Hall effect (THE) are observed at a low magnetic field for each compound below respective TC. The plateau-like MR is attributed to a compensation of negative MR with a ferromagnetically ordered structure of Tb atoms by positive MR with a noncoplanar spin structure of the Co Kagome lattice. The THE is attributed to the noncoplanar spin structure of the Co Kagome lattice only. The MR and the Hall resistivity of each compound are reduced dramatically and undergo a reversal of its sign during cooling. The reversal phenomenon at the low temperature can be related to the freezing of spins of Co atoms. The transport in DyCo2 is more sensitive to magnetic fields than that in TbCo2 which is consistent with a stronger 4f–3d interaction. Observations of these transport phenomena make RCo2 compounds promising for functional applications in spintronic devices. [ABSTRACT FROM AUTHOR]

Six symmetrical ferrocenyl Schiff base materials were synthesized and characterized by UV, 1 H NMR, mass spectrometry (MS) and elemental analysis. Their off-resonant third-order nonlinear optical properties were measured using femtosecond laser and degenerate four-wave mixing (DFWM) technique. The third-order nonlinear optical susceptibilities χ (3) were 1.961–6.363 × 10 −13 esu. The nonlinear refractive indexes n 2 were 3.609–11.716 × 10 −12 esu. The second-order hyperpolarizabilities γ of these molecules were 1.967–6.388 × 10 −31 esu. The response time were 45.759–73.079 fs. The results indicate that these materials have potential nonlinear optical applications. [ABSTRACT FROM AUTHOR]

A novel intumescent flame retardant-polyacrylamide (IFR-PAM)was prepared by the copolymerization of N1-(5,5-dimethyl-1,3,2-dioxaphosphinyl-2-yl)-acrylamide(DPAA) and acrylamide and was used to prepare various IFR-PAM/grapheneoxide (GO) thin films via layer-by-layer (LbL) assembly as a flameretardant coating system for cotton fabric. Films assembled with IFR-PAMand GO nanosheets show linear growth as a function of the number ofbilayer deposited. Higher hydrophobe DPAA content of IFR-PAM resultsin much thicker assemblies due to hydrophobic association. The resultsfrom X-ray diffraction (XRD), atomic force microscopy (AFM), and scanningelectronic microscopy (SEM) indicate that the IFR-PAM/GO ultrathinfilms with high homogeneity and orientation are formed by LbL assemblydriven by hydrogen interaction. The thermogravimetric analysis (TGA)results indicate that the IFR-PAM/GO coating improves the thermalstability of cotton fabric. Cone calorimeter testing shows that theIFR-PAM/GO-coated fabrics become less flammable with lower peak heatrelease rate (PHRR) and longer time to ignition (TTI). SEM imagesdemonstrate that the surface of the IFR-PAM/GO-coated fabrics is coveredby a layer of continuous and compact char after combustion. [ABSTRACT FROM AUTHOR]

Abstract: Post-treatments of the micro-molded poly(4-styrenesulfonic acid-co-maleic acid, 1:1 SS:MA) sodium salt (PSSMA)/poly(diallyldimethylammonium chloride) (PDADMAC) multilayers in water or at elevated temperature were conducted to disclose the stability and transformation of patterns prepared at different conditions. The compression induced patterns kept unchanged regardless of the incubation time, while the lateral flow induced patterns disappeared rapidly within 10min in water. Results showed that the pattern disappearance was not caused by the remodeling or swelling of the multilayers, but caused by mass loss of the uncompressed region. Heat treatment of the high ridge patterns could greatly decrease their height and stabilize the pattern structure. The double strip patterns could be transformed to the high ridge patterns and the linear patterns by annealing at 70°C for 3h and 6h, respectively. Therefore, the pattern features and stability against water etching can be effectively modulated by the post-treatment time at elevated temperature. [Copyright &y& Elsevier]

3H-Benzo[1,2]-dithiole-3-thiones were prepared from potassium sulfide and 2-halobenzaldehydes in moderate-to-good yields, and a plausible mechanism for this catalyst-free intramolecular heteroannulation reaction has been proposed. The Knoevenagel condensation reactions of 3H-benzo[1,2]dithiole-3-thiones with active methylene compounds such as ethyl 2-cyanoacetate and diethyl malonate, and the three-component one-pot reactions of potassium sulfide, 2-halobenzaldehydes, and ethyl 2-cyanoacetate, affording the corresponding products, have been developed. GRAPHICAL ABSTRACT [ABSTRACT FROM AUTHOR]

Abstract: Two new nickel(II) complexes were synthesized and characterized by UV, MS and elemental analysis. Their off-resonant third-order nonlinear optical properties were measured using femtosecond laser and degenerate four-wave mixing technique. The third-order nonlinear optical susceptibilities χ (3) are 3.38×10−13 esu and 3.64×10−13 esu. The nonlinear refractive index n 2 are 6.22×10−12 esu and 6.70×10−12 esu. The second-order hyperpolarizabilities γ of the molecules are 3.38×10−31 esu and 3.65×10−31 esu. The response times are 61fs and 74fs. The results show that the two complexes have potential nonlinear optical applications. [ABSTRACT FROM AUTHOR]

Abstract: A novel, piperidene-catalysed, one-pot synthesis of 3-(2′-benzothiazolyl)coumarins was undertaken, starting from salicylaldehydes, ethyl cyanoacetate and o-aminobenzenethiols in ethanol. Salicylaldehydes with electron-donating group gave optimum yields. The novel method is characterized by mild reaction conditions, simple procedure and low waste. All compounds were fluorescent in solution emitting either green light (490 nm) or blue light (440–460 nm). Two typical fluorescence peaks were found in the three-dimensional fluorescence spectra. [Copyright &y& Elsevier]

Abstract: Ten new organic donor-π-acceptor compounds were synthesized and characterized by UV, IR, 1H NMR and elemental analysis. Off-resonant third-order nonlinear optical properties of the compounds were measured using femtosecond laser and degenerate four-wave mixing technique. The third-order nonlinear optical susceptibilities χ (3) were 3.50–4.29×10−13 esu. The nonlinear refractive indexes n 2 were 6.42–7.89×10−12 esu. The second-order hyperpolarizabilities γ of the molecules were 3.63–4.47×10−31 esu. The response times were 69–112fs. The results show that these compounds have potential nonlinear optical applications. [Copyright &y& Elsevier]

A series of new 3-(indol-3-yl)-4-(pyrazolo[3,4-c]pyridazin-3-yl)-maleimides were synthesized and evaluated for their inhibitory activity against IDH1-R132H. Most compounds exhibited significant potency to IDH1-R132H inhibition. Among these, 3-(1-(3-(1H-imidazol-1-yl)propyl)-6-bromo-1H-indol-3-yl)-4-(1-methyl-1H-pyrazolo[3,4-c]pyridazin-3-yl)-1H-pyrrole-2,5-dione (compound IXb), was the most promising IDH1-R132H inhibitor (IC50 = 0.031 μM) and could significantly inhibit the production of 2-HG in U87MG IDH1-R132H cells. Preliminary structure–activity relationships and molecular modeling studies are discussed based on the experimental data obtained. [ABSTRACT FROM AUTHOR]

Rapid solidification of the intermetallic Ni 3 Sn compound from an undercooled liquid was investigated using time-resolved synchrotron X-ray diffraction. Primary growth of an ordered and a disordered cubic solid was observed in situ at a low and a high undercooling, respectively. The disordered cubic solid was reordered after rapid solidification and experienced a solid-state transformation in cooling. A HRTEM study revealed high density of crystal defects and nanodomains in the transformed matrix. A HAADF-STEM study determined that the nanodomains are antiphase domains with chemical disorder. These observations indicated a possibility of online control of mechanical properties in additively manufactured intermetallics. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Pseudobinary Gd 5 (Si,Ge) 4 compounds show a giant magnetocaloric effect due to an intriguing structure-magnetism interplay. Here, we report a high resolution transmission electron microscopic study of microstructure in a melt-grown compound of Gd 5 Si 1.5 Ge 2.5. Electron diffraction showed that mesoscopic microstructure of the compound consists of crystals of a monoclinic structure and two kinds of orthorhombic structure. However, atomic-level imaging revealed a coexistence of mosaic-like nanodomains of these structures in each crystal. The nanodomains have twin-like interfaces along the b axis of the crystal but have semicoherent interfaces along a perpendicular axis due to stacking faults. Such a nanoscale structural heterogeneity is due to covalent bond-controlled phase separation at elevated temperatures. This finding offers insights into phase relations and abnormal magnetic behavior of Gd 5 (Si,Ge) 4 compounds and points out a route of synthesizing bulk nanocomposites via nanoscale phase separation. Image, graphical abstract [ABSTRACT FROM AUTHOR]