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Dynamic heterogeneity as one of the most important properties in supercooled liquids has been found for several decades. However, its structural origin remains open for many systems. Here, we propose a new structural parameter to characterize local atomic packing in metallic liquids. It is found that the new parameter in a simulated metallic glass-forming liquid is closely correlated with potential energy and atomic mobility. It also exhibits significant spatial heterogeneities and these structural fluctuations show close correlation with the spatial distribution of the long-time dynamic propensities. Therefore, our results provide a direct evidence of the correlation between atomic structure and dynamical heterogeneity. The new structural parameter might be used to reflect the structural “defect” in metallic liquids and glasses and further play an important role to uncover the structure-property relationship in these disordered systems. [ABSTRACT FROM AUTHOR]

Since the structural characterization of Fe-based disordered system is less than other metallic glasses, we investigate the Fe 76 − 2 x Y 4 + x B 20 + x ( x = 0 and 2) glasses and melts via the variation of tri-capped triangular prism (TTP) polyhedron with changing the composition. B-centered clusters mainly appear in the manner of TTP polyhedron in both alloys, which is strengthened by increasing yttrium and boron contents ( c Y and c B ) and considered as the network/backbone in the Fe-based glassy alloys. Increasing c Y and c B improves the onset temperature of the first crystallization event with decreasing its activation energy, deteriorates the corrosion resistance of present alloys in NaCl and H 2 SO 4 solutions, and triggers the formation of nanoscale network structure. These experimental results can be ascribed to the strengthened network/backbone in the alloys. [ABSTRACT FROM AUTHOR]

The dealloying performances of the free side and roller side of the Al 50 Au 50 ribbons are investigated under different dealloying conditions. The free side consisting of Al 2 Au, AlAu, and AlAu 2 phases undergoes more severe corrosion than the monophasic AlAu roller side. The Al 2 Au phase not only acts as an anodic electrode in galvanic corrosion of free side but also leaves nanoporous Au behind and induces further dealloying of AlAu by the capillary action. The oxide film is confirmed as Al–O film with solubilized Au atoms. During corrosion, the Au atoms in oxide film tend to segregate into Au-rich and Au-lacked regions. The Au-rich region remained can enhance the Au-content on surface and impede the further corrosion. [Display omitted] • The Al 50 Au 50 ribbon exhibits different microstructures in its two sides. • The Al 2 Au in free side promotes the dealloying of AlAu. • Au is solubilized in oxide film and tends to segregate during dealloying. [ABSTRACT FROM AUTHOR]

Abstract: The corrosion behavior of Fe78Si9B13 glassy ribbons in 0.3M NaCl+0.06M NaOH solution under magnetic field has been studied by immersion and electrochemical tests such as electrochemical impedance spectroscopy (EIS) technique and polarization scanning, and the corroded morphology and products of ribbons have been measured by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS). It is found that the added magnetic field induces a severe corrosion behavior of the Fe-based glassy ribbons despite being in immersion or electrochemical corrosion, reflecting in a larger corrosion rate and a lower pitting potential. In addition, the magnetic field can decrease the charge transfer resistance (R t) in the equivalent circuit of the electrochemical reaction, can trigger the occurrence of filiform corrosion and cracks, and can hinder the formation of silicon dioxide on the sample surface. The severe electrochemical corrosion of Fe-based glass alloy under magnetic field is explained by the effects of magnetohydrodynamic (MHD). [Copyright &y& Elsevier]

Highlights: [•] E corr of samples increases but E pit decreases with increasing S C. [•] Si distribution on corroded surfaces depends on the quick growth of iron oxides. [•] Thickness of oxidation film decreases with increasing S C. [•] Critical concentration is found at 0.6M in NaCl immersion experiments. [ABSTRACT FROM AUTHOR]

Highlights: [•] Mechanical and autoclave compression induce crystallization of amorphous sample. [•] Mechanical and autoclave compression affects amorphous alloys differently. [•] Mechanical and autoclave compression can improve hardness of amorphous alloy. [•] Compression effects can be explained by percolation of backbone clusters. [ABSTRACT FROM AUTHOR]

Abstract: To clarify the relation between the thermodynamics and metastable pitting behavior of Al–Ni–Gd glassy alloys, the as-spun ribbons were investigated using various experimental methods and ab initio molecular dynamic simulations. The results show that the relative area of main peak shoulder in XRD patterns, onset crystallization temperature, contraction degree of samples increase with increasing c Ni. The peak for the metastable pitting events in the polarization curves with Cl− containing solutions is accelerated by increasing c Ni. The variation of thermal and electrochemical properties of samples is attributed to the strong interaction of Al–Ni bond based on the atomic structure analysis. [Copyright &y& Elsevier]

Abstract: The equiatomic multiprincipal CoCrFeNiCuAl high-entropy alloy was prepared using a vacuum arc melt casting method. The as-cast alloy was subsequently annealed at 1000°C for 2h and the annealing effects on the structure and properties evolution were investigated. The as-cast alloy is composed of simple BCC and FCC solid solutions. The “2” FCC phase precipitates from the ordered BCC matrix and the FCC phases become dominated after the alloy was annealed. Both alloys show typical cast-dendrite morphology and similar elemental segregation. The as-annealed alloy exhibits high strength and excellent ductility of 1.63GPa and 34%, respectively. Both alloys possess high saturated magnetization and undergo a ferromagnetic transition. [Copyright &y& Elsevier]

Abstract: The (Fe0.78Si0.09B0.13)100−x Zr x (x =0, 1 and 2) glassy alloys have been investigated in this paper. The experimental results show that the minor addition of Zr can improve the thermal stability of the Fe-based alloy. The thermal contraction process of the ribbons is mainly dependent on the crystallization process. With increasing Zr content (c Zr), the difference (Δd) between the nearest neighbor distance (d exp) deduced from the X-ray diffraction pattern and the estimated nearest neighbor distance d cal, the onset crystalline temperature (T x), the reduced crystalline temperature (T rx), the apparent activation energy (E p1) for the first crystallization, and the difference (Δα) between the expansion coefficients of amorphous ribbons (α amor) and fully crystallized counterparts (α cryst) of the Fe-based glassy alloys first increase and then decrease, which is opposite to the change of the saturation magnetization (M s). The variation of these parameters can be explained by the deviation degree from the equilibrium state of the amorphous ribbons. Besides the M–T measurement, the Curie temperature (T c) of the Fe-based glassy alloys can also be scaled by the bump and inflection temperatures (T c,dsc and T k) in differential scanning calorimetric and dilatometric curves, respectively, showing a slight decreasing tendency with increasing c Zr. [Copyright &y& Elsevier]

Abstract: The equiatomic multicomponent CoCrFeNiTiAl high-entropy solid solution alloy was synthesized by mechanical alloying (MA). The effects of milling duration and subsequent annealing on the structure and morphology evolution were investigated. Supersaturated BCC and FCC solid solutions appear when the blended powder is ball milled more than 18h. The 30h ball milled alloy powder shows excellent chemical homogeneity and refined morphology with mean particle size of less than 5μm. The microscaled particles are actually hard agglomerations of nanoscaled crystallines with crystal size of about 40nm. The phase composition transforms to two BCC solid solutions when the 30h mechanically alloyed powder was annealed at 600°C for 1h. The simple solid solution structure can be maintained even after the alloy was annealed at 1000°C. The 30h milled alloy powder was subsequently consolidated by spark plasma sintering (SPS) at 800°C for 10min. The sintered sample Exhibits 98% in relative density and 432 HV in Vickers hardness. [Copyright &y& Elsevier]

Abstract: CoCrFeNiTiAl x (x values in molar ratio, x =0, 0.5, 1.0, 1.5 and 2.0) high-entropy alloys were prepared using a vacuum arc melting method. The effects of Al addition on microstructure and mechanical properties were investigated. The results show that only a face-centered cubic (FCC) crystal structure phase is observed in the CoCrFeNiTi alloy. The phase composition transforms to stabilized body-centered cubic (BCC) structure phases and typically cast dendrite structure appears when Al is added. The dendrite region is rich in Co, Ni, Ti and Al elements while the interdendrite region is rich in Fe and Cr elements. Subgrains and nanosized precipitates are observed in the as-cast CoCrFeNiTiAl alloy. These CoCrFeNiTiAl x high-entropy alloys exhibit excellent room-temperature mechanical properties. For CoCrFeNiTiAl1.0 alloy, the compressive strength and elastic modulus reach as high as 2.28GPa and 147.6GPa, respectively. High density of dimple-like structure is observed from the fracture surfaces of the Al0 alloy, while alloys with Al addition show typical cleavage fractures with river-like patterns and cleavage steps. [Copyright &y& Elsevier]

Abstract: Liuwei Dihuang, whose compatibility to prescription was well established as Traditional Chinese Medicine (TCM), has been demonstrated useful for the treatment of diseases in China. However, the absorption and effect of the raw plant materials of Liuwei Dihuang were not consistent. To optimize the physicochemical and medicinal characterization of Liuwei Dihuang, the raw plant materials of Liuwei Dihuang were ground to 161.9 nm particles by HSCS (High Speed Centrifugal Sheering) pulverizer. The nano particles were characterized by polarizing microscope and SEM. Paeonol was analyzed by HPLC (High Performance Liquid Chromatography). The plasma concentrations of paeonol were determined to evaluate the characterization of nano Liuwei Dihuang in rats. The results showed that the plant cell walls were broken into pieces and the extraction efficiency of paeonol was increased by 23.5% after nano pulverization. The maximal plasma concentration (c max) was increased from 32.7 μg/mL to 61.6 μg/mL, while the time (t max) to the maximum plasma concentration was decreased from 3.5 h to 1.5 h. Nano pulverization can obviously increase the absorption speed and absorbing capacity of Liuwei Dihuang in rats. [Copyright &y& Elsevier]

Abstract: About 133.5 nm Radix salvia miltiorrhiza nanoparticles were prepared by high speed centrifugal sheering pulverizer and the nanoparticles were characterized by TEM in this study. Microcapsules containing R. salvia miltiorrhiza nanoparticles were produced by spray-drying technique using different proportions of gelatin and sodium salt of carboxymethylcellulose (CMC-Na) as wall materials. The effects of inlet temperature, flow rate, spray-gas flow and the ratio of M core/M wall on encapsulation yield (EY) and encapsulation efficiency (EE) were investigated. The EE was determined by reverse high performance liquid chromatography (HPLC); the resulting microcapsules were characterized by FT-IR, SEM, and X-ray diffraction analysis. In addition, in vitro release characters of R. salvia miltiorrhiza raw powder, spray-dried powder and microcapsules were also studied. The results showed that spray-dried microcapsules had a regular spherical shape but the majority presented rough surfaces or invaginations with a diameter of 2–5 μm. R. salvia miltiorrhiza nanoparticles were embedded in the wall system consisting of gelatin and CMC-Na. Higher EE and EY were obtained under the inlet temperature of 80 °C and the ratio of M core/M wall of 1/4. In vitro release study showed that R. salvia miltiorrhiza microcapsules could regulate drug release. This study may be helpful to the pharmaceutical application of R. salvia miltiorrhiza. [Copyright &y& Elsevier]

Abstract: Microhybridization as a surface modification method was used to prepare TiB2/Al2O3 core/shell particles in this paper. The experiment included two parts. One part was that TiB2 (micron)/Al2O3 (nano) core/shell particles were fabricated directly by hybridization. Another part was that TiB2 (micron)/Al2O3 (sub-micron) composite particles were prepared using PE-wax as a transition layer, which has good binding capacity for both of them. PE-wax particles were first coated onto TiB2 particles by hybridization, and then the sub-micron Al2O3 particles were coated onto the surface of TiB2/PE-wax particles again. The coating process, effects of the transition layer and the structure of core/shell particles were investigated. The core/shell particle features were characterized by SEM, TEM, EDS, XPS and XRD. Results showed that after hybridization nano-Al2O3 particles were coated directly on the surface of TiB2 particles, but the sub-micron Al2O3 could not. When adding PE-wax as a transition layer, PE-wax was filmed on the surface of TiB2 particles and the sub-micron Al2O3 particles were coated successfully on the surface of TiB2/PE-wax particles by hybridization. The PE-wax transition layer plays a role of binder in forming TiB2(PE-wax)/Al2O3 core/shell particles. [Copyright &y& Elsevier]

We report the study on the MEMS rf switches with low actuated voltage. The switch structure has been optimized by the calculation on the dependence of actuated voltage on the Young’s modulus of membrane materials and geometrical sizes. Compared with gold material, AlSi0.04 is a good movable film material having lower actuated voltage (5 V). The switches array is made on the coplanar waveguide (CPW) transmission lines, which were fabricated on quartz, high resistivity (>2 kΩ cm) silicon and porous silicon substrates respectively. The pull-in voltage of the variable capacitor was below 20 V. Furthermore, the 21 bridges MEMS switch array had 372°/3.5 mm phase shift operating at 35 GHz. The chip is compacted into a size of 3.5 mm×0.5 mm. [Copyright &y& Elsevier]

• The corrosion resistance of Fe-Si-B amorphous alloy can be improved by adding Nb • The hardness of Fe-Si-B-Nb ribbons increases and the coercivity decreases • Nb can increase the size and number of ordered clusters • The segregation of Nb and B occurs below the surface of the ribbon Nb is a noble and important element for the Fe based glass manufacture. The mechanical properties, magnetic properties and corrosion behavior of (Fe 78 Si 9 B 13) 100- x Nb x (x = 0, 7 and 10) glassy ribbons have been studied by various experimental methods. With the addition of Nb element, the hardness of the Fe-based glasses increases and their coercivity decreases, which is attributed to the ordering tendency of atomic structure by adding Nb atoms. In the potentiodynamic polarization and Mott-Schottky plots, Fe-based glassy ribbons with x = 7 and 10 have a wide passivation platform and an n-type semiconductive surface, while the ribbon with x = 0 does not. By XPS analysis, Nb and B tend to segregate beneath the ribbon surface and form the stable passive film. The Nb addition can improve the hardness, soft magnetism and corrosion resistance of Fe based glasses and will help us to seek for the new type Fe based glasses. [ABSTRACT FROM AUTHOR]

• Two stages can be distinguished in dealloying process of Al 2 Au ribbon. • Multi-resolution analysis on OCP is performed in an innovative way. • The Al 2 Au first undergoes local corrosion and then global corrosion. Two stages, induction stage and pore-formed stage, were distinguished in Al 2 Au's dealloying process in HCl solutions by OCP, SEM and XPS characterization. In induction stage, the Au state with binding energy 85.4 eV (labelled as Al 2 Au (I)) was transformed into the state 84.7 eV (Al 2 Au (II)); in pore-formed stage, nanoporous structure started to be formed, Al 2 Au (II) and residual Al 2 Au (I) were transformed into the state 83.7 eV (pure Au). Multi-resolution analysis on OCP noise revealed that the induction stage and pore-formed stage undergo different corrosion modes: the former is local corrosion and the latter is global corrosion. [ABSTRACT FROM AUTHOR]

The effect of Nb element on the corrosion resistance of Fe-based metallic glasses in the alkaline environment has been investigated with various techniques like potentiodynamic polarization test, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS) and potentiostatic tests. With increasing the Nb content, the passivation stability of as spun Fe 87- x B 13 Nb x (x = 0, 7 and 10) glassy ribbons increases and the thickness of their passive film decreases according to XPS analysis. In the potentiostatic test, the ribbons have a transition potential E trans of −0.58, −0.47 and −0.38 V SCE with x = 0, 7 and 10 respectively, showing an increasing passivation stability with increasing x , which is more sensible than the potentiodynamic parameters like i pass and E pit. Meanwhile, Nb element has the ability to repair pitting holes. In potentiostatic test, the long constant potential treatment below E trans may enhance the generation of ribbon's passivation film, indicating that the potentiostatic test can tune the passivation behavior of metallic alloys. • With increasing the Nb content, the Fe0 and Nd0 XPS peaks rise. • In potentiostatic test, the ribbons have a transition potential E trans. • Nb element has the ability to repair pitting holes. • Potentiostatic test can indirectly reflect the passivation behavior of alloys. [ABSTRACT FROM AUTHOR]

• Monophasic Al 50 Au 50 ribbon has a wide passivation region in HCl solution. • The passive film of monophasic ribbon has a double-layer structure. • Monophasic ribbon has a higher corrosion resistance than multiphasic one. • Al 2 Au phase in multiphasic ribbon promotes corrosion in HCl solution. Monophasic Al 50 Au 50 ribbons (labelled as S 2ann) were obtained by melt spinning and annealing. The corrosion properties of S 2ann were investigated in AlCl 3 + HCl solution with as-spun multiphasic ribbons (labelled as S 2sp) for comparison. S 2ann is self-passivated and has a wide passivation region, while S 2sp tends to undergo Al 2 Au-induced selective dissolution under anodic polarization. Besides, S 2ann has a fluctuant open-circuit potential and a passive film with p-type semiconductor feature, which are not found in S 2sp. The passive film of S 2ann is examined to be Au-contained Al 2 O 3 with a double-layer structure. [ABSTRACT FROM AUTHOR]

Repair and maintenance services are among the most lucrative aspects of the entire automobile business chain. However, in the context of fierce competition, customer churns have led to the bankruptcy of several 4S (sales, spare parts, services, and surveys) shops. In this regard, a six-year dataset is utilized to study customer behaviors to aid managers identify and retain valuable but potential customer churn through a customized retention solution. First, we define the absence and presence behaviors of customers and thereafter generate absence data according to customer habits; this makes it possible to treat the customer absence prediction problem as a classification problem. Second, the repeated absence and presence behaviors of customers are considered as a whole from a lifecycle perspective. A modified recurrent neural network (RNN-2L) is proposed; it is more efficient and reasonable in structure compared with traditional RNN. The time-invariant customer features and the sequential lifecycle features are handled separately; this provides a more sensible specification of the RNN structure from a behavioral interpretation perspective. Third, a customized retention solution is proposed. By comparing the proposed model with those that are conventional, it is found that the former outperforms the latter in terms of area under the curve (AUC), confusion matrix, and amount of time consumed. The proposed customized retention solution can achieve significant profit increase. This paper not only elucidates the customer relationship management in the automobile aftermarket (where the absence and presence behaviors are infrequently considered), but also presents an efficient solution to increase the predictive power of conventional machine learning models. The latter is achieved by considering behavioral and business perspectives. [ABSTRACT FROM AUTHOR]

• Dendritic degree of α-Mg phase in ingots changes with their composition. • Amorphous fraction of ribbons agrees with α-Mg dendritic degree. • Reusability of ribbons in methyl blue decolorization agrees with amorphous fraction. • Structural heredity of alloys exists in solidification and decolorization processes. The AZ91D (AZ91), Mg 78 Zn 22 (MZ) and Mg 73 Zn 22 Ca 5 (MZC) alloys are cast in ingots and then spun in ribbons with crystalline, semi-amorphous and fully amorphous structures, respectively. The α-Mg dendritic degree of ingots ranks as AZ91 ≤ MZ ≤ MZC. Three as-spun ribbons have a similar decolorization rate constant k on methyl blue (MB) solution; the immersed amorphous MZC ribbon has a much higher k than its as-spun counterpart, while the immersed AZ91 and MZ ribbons have a much lower k than their as-spun counterparts. The immersed MZC ribbon has an excellent reusability in MB decolorization due to the developed nanoporous luffa-sponge-like structures on ribbon surface, which possibly can be ascribed to the intrinsic netlike structural units in the amorphous and liquid states and to the structural heredity during solidification. This work not only provides a benign, efficient and low-cost decolorizer for the synthetic dyes, but also expands the application field of Mg-based amorphous alloys. [ABSTRACT FROM AUTHOR]