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Pathogenic microorganisms are one of the main environmental factors causing biological diseases, and their rapid spread and variety may lead to the outbreak of animal infectious diseases or plant diseases. However, the air environment is complex, the pathogen fungal infectious disease outbreak early concentration is low and the shape and size is small. There is a lack of rapid, accurate, portable and low-cost early detection methods for pathogenic fungi. Here, we construct a multispectral diffraction microfluidic sensing system for pathogenic fungi. Firstly, a microfluidic chip with the function of targeted purification of pathogenic fungi was designed, and the diffraction fingerprint of purified pathogenic fungi was collected on the chip. By analyzing the light diffraction spectrum, the morphological and absorption characteristics of different fungi at different wavelengths were obtained, and different kinds of pathogenic microorganisms in complex environment were identified. Then, seven weighting schemes were compared to select the characteristic wavelength that best reflects spore differences. Dispersion intensity compared of fingerprint (DICF) and Relative superimposed light intensity (RSLI) were defined as training indexes. To obtain higher recognition accuracy, two parameters of cluster centroid distance and dispersion are defined as evaluation indexes. Finally, 5 kinds of pathogenic fungi and particles with similar characteristics were selected for experimental verification, and the identification accuracy was 98.7%. We can foresee potential applications for this approach in disease control and environmental monitoring of airborne pathogens. • Pathogenic fungi in complex environment are low in concentration, which is difficult to capture and distinguish. • The microfluidic chip is designed to integrate separation, enrichment, detection and verification on chip. • The multi-spectral diffraction sensing system enables rapid and accurate identification of pathogenic bacteria. • It has a broad prospect in restraining the recessive spread of pathogenic microorganisms and environmental monitoring. [ABSTRACT FROM AUTHOR]

In this study, PyC coating with different thickness was prepared on SiC fibers via chemical vapor deposition method. Uncoated and PyC coated SiC fibers were heat treated in Ar atmosphere under different annealing condition. The effects of PyC coating on the mechanical properties of SiC fibers at room temperature were investigated. The morphology, composition, structure and mechanical properties of SiC fibers after high temperature treatment were also studied. The results showed that PyC coating could reduce the dispersion of tensile strength for SiC fibers. Weibull modulus increased from 4.19 (SiC fiber) to 5.59 (PyC700 fiber), while the tensile strength decreased a little with the increment of PyC coating thickness. Furthermore, PyC coating could remarkably retard Si sublimation from SiC fiber at high temperature. Uncoated SiC fiber was converted to porous pure-carbon fiber after being annealed at 2000 °C for 5 h, while PyC700 fiber still showed relative dense SiC core after the same treatment. To a certain extent, the inhibition ability was improved with increment of PyC coating thickness. In addition, PyC coated SiC fibers could maintain more tensile strength after being annealed at 1800 °C for 1 h. The tensile strength retention of uncoated SiC fiber was 27.3%, while that of PyC700 fiber could reach up to 43.2%. [ABSTRACT FROM AUTHOR]

In this work, a copper–brass hetero-laminate with dual-heterostructured interfaces was fabricated by diffusion welding in combination with cold deformation and annealing. These dual-heterostructured interfaces possess the characteristics of both gradient interface and sharp interface. The evolutions of geometrically necessary dislocations (GNDs) and local strains near these dual-heterostructured interfaces were investigated by in-situ and quasi in-situ tests. By employing a constitutive model, the evolutions of GND density and the HDI synergistic strengthening mechanism were systematically explored. The results demonstrated that the distribution of GNDs and local strains near the coarse/fine-grained interface exhibited a gradient feature, without any obvious concentrations of GNDs and strains, which can be attributed to the transition effect of the gradient interface. Furthermore, the density of sample-scale GNDs accumulated near the coarse/fine-grained interface was found to be at least one order of magnitude lower than that of grain-scale GNDs accumulated near grain boundaries. Both the constitutive model and experimental results confirmed that grain-scale GNDs serve as the primary origins of significant HDI stress, rather than the sample-scale GNDs. • GND density and local strains distribute in gradient manner near the coarse/fine-grained interface. • Numerous grain-scale GNDs accumulate around GBs to accommodate the strain gradient between adjacent grains. • A small number of sample-scale GNDs accumulate around the coarse/fine-grained interface. • HDI strengthening originates largely from the accumulation of grain-scale GNDs, rather than the sample-scale GNDs. [ABSTRACT FROM AUTHOR]

This paper investigates zero-determinant (ZD) strategies for iterated multi-player multi-action games with multiple memories. First, using the semi-tensor product (STP) of matrices, an equivalent algebraic model for the iterated game is proposed. Based on the algebraic expression, ZD strategies are derived for repeated finite games with multiple memories, allowing players to unilaterally apply a linear relationship among their augmented expected payoffs regardless of their opponents' strategies. Furthermore, ZD strategies for repeated symmetric and skew-symmetric games are considered, based on which the coupling correlations among players' payoffs, as well as the structure of the payoff vectors, are clarified. It is found that in repeated symmetric games, any player can get the same augmented expected payoff by employing a ZD strategy. In repeated skew-symmetric games, it is possible for all participants to achieve a zero-sum outcome. To execute the aforementioned ZD strategies, some identical elements are required in each augmented payoff vector for symmetric games, whereas the payoff vector for skew-symmetric games must contain zero elements. [ABSTRACT FROM AUTHOR]

• The WNZ re-precipitates η′ and η particles and forms the PFZ in the vicinity of grain boundaries. • Intergranular microcracks initiate from the WNZ due to the local strain incompatibility. • Low-cycle fatigue failure occurs at the WNZ instead of the LHZ. High-temperature ratcheting fatigue behavior of a friction stir welding (FSW) Al-Zn-Mg-Cu alloy was investigated. The substructured grains in the weld nugget zone (WNZ) undergo continuous dynamic recrystallization (CDRX) during ratcheting fatigue. The WNZ re-precipitates intragranular η′ and η particles and forms the precipitate free zone (PFZ) in the vicinity of the grain boundaries. At high mean stress or stress amplitude, ratcheting failure with obvious necking takes place due to large ratcheting strain. At low stress levels, intergranular fatigue microcracks initiate from grain boundaries of the WNZ due to the local strain incompatibility between the PFZ and grain interiors. The fatigue microcracks coalesce along grain boundaries and propagate via typical striation formation mechanisms. Low-cycle fatigue failure occurs at the WNZ instead of the low hardness zone (LHZ). [ABSTRACT FROM AUTHOR]

A bi-layer environmental barrier coating (EBC) consisting of silicon(Si) bond coat/mixed ytterbium disilicate (Yb 2 Si 2 O 7) and ytterbium monosilicate (Yb 2 SiO 5) topcoats has been successfully prepared to completely wrap up the SiC f /SiC composites and the protective effects of such EBC have been evaluated by soaking them in a mixed 50% O 2 and 50% H 2 O corrosive gases at 1300 °C for various times. In topcoats, Yb 2 Si 2 O 7 is the major phase, providing good thermal expansion coefficient (CTE) matching with composite substrate and thus excellent thermal shock resistance, whereas Yb 2 SiO 5 is the dispersing minor phase, providing improved water vapor corrosion resistance. The completely wrapping up of SiC f /SiC composites by above EBC system is employed to avoid direct exposure to the corrosive conditions, making it possible to evaluate the genuine protection effects of current EBCs. Under 1300 °C water vapor corrosion, the mass change, the phase composition and the evolution of microstructure are investigated, which suggest that the bi-layer EBC has excellent performance on protecting SiC f /SiC composites from water vapor corrosion at 1300 °C. [ABSTRACT FROM AUTHOR]

Bis(diphenyl phosphate) imine(Htpop) was synthesized as an adsorbent for the effective removal of U(VI) from aqueous solutions using triphenyl phosphate(TPP) as the starting material. Htpop possesses notable polarity, characterized by the presence of -P O(phosphoryl) and -N-H(imino) functional groups, along with other bulky substituents. It has the capability to form chelates with metal ions, thus enabling the removal of radionuclide U(VI) from aqueous solution. The overall adsorption experiment shows that both phosphoryl and imino groups interact with uranyl ions, and the removal rate reaches 99.53 % at pH 6.0. The adsorption process conforms to the Pseudo-second-order kinetic model and Langmuir isotherm model. [ABSTRACT FROM AUTHOR]

Effect of a wide range of shot peening (SP) coverage on hydrogen diffusion and hydrogen embrittlement (HE) of a steel consisting of ferrite and pearlite was investigated. Conventional SP (CSP) reduces diffusivity and HE because of increase of dislocation trapping sites. Although severe SP (SSP), which uses higher coverages than CSP, increases the area of ferrite grain boundaries as a result of grain refinement, it cannot suppress further the diffusion and HE, as it cannot induce a further evident increase in strong hydrogen trapping sites such as dislocations. However, when coverage is increased to so high that causes the breaking and refinement of pearlite phase, diffusion and HE is suppressed further, because the dispersed distribution of ultrafine pearlite particles within ferrite matrix provides more strong interface trapping sites. SP-induced change of trapping sites plays a more critical role in HE and diffusion, in comparison with induced residual compressive stresses. Image 1 • A very wide shot peening coverage range was considered for a ferrite-pearlite steel. • SP-induced increase of trapping sites plays a more critical role in HE and diffusion. • Conventional shot peening suppresses HE because of increase of dislocation traps. • Severe shot peening cannot suppress HE further if it cannot increase strong H traps. • Using a very high coverage to produce more interface traps can suppress HE further. [ABSTRACT FROM AUTHOR]

During tensile deformation, nanostructured (NS) metals often fail soon after yielding by forming a localized shear band. Here we report the observation of high density of shear bands that are homogeneously dispersed in the NS layer of a gradient Ni sample. These shear bands were nucleated at early elastic/plastic strain stage, reached number saturation at ∼3% strain, and remained arrested by the central coarse-grained (CG) matrix during the entire plastic deformation, resulting in a uniform tensile plasticity comparable to that of CG matrix. The formation of dispersed shear bands was promoted by the elastic/plastic interaction between NS surface layer and CG matrix, and affected by the surface roughness and the hardness variation in the NS surface layer. The width of shear bands remained constant, but the intensity of strain accumulation increased almost linearly with applied tensile strain, suggesting a stable shear banding process. Microstructure examination revealed that the strain in shear bands was accommodated by mechanically driven grain boundary migration and grain coarsening. These results clarify the fundamental questions: why/how does the NS layer supported by CG matrix achieve large uniform elongation? Moreover, the findings demonstrate the possibility of activating dispersed stable shear bands by synthesizing gradient architecture for optimized mechanical performances, i.e., a new strategy for evading the strength-ductility tradeoff in NS metals. Image 1 • Questions 'why/how does the NS layer supported by CG matrix achieve large uniform elongation?' are clarified. • Dense shear bands are homogeneously dispersed in the NS layer of gradient Ni. • Shear bands evolved stably during deformation, resulting in large uniform elongation. • Elastic/plastic interaction between NS and CG layers promoted the nucleation of shear bands. • Strain in shear bands is accommodated by mechanically driven grain coarsening. [ABSTRACT FROM AUTHOR]

In this paper the long-term oxidation resistance of SiC f /SiC composites manufactured by a single PIP technique and a hybrid CVI-PIP technique at 1200 °C in a static air has been systematically studied. It has been found that after oxidation at 1200 °C for 200 h, SiC f /SiC composites by the hybrid CVI-PIP technique can retain flexural strength as high as 76% and still exhibit a typical quasi-plastic fracture. In contrast, after oxidation for 100 h, SiC f /SiC composites produced by the single PIP technique can only keep 31.8% of their initial flexural strength and demonstrate a typical brittle fracture. An insertion of a dense and crystalline CVI derived SiC layer between fibers/interphase and PIP derived matrix makes the difference. To be specific, for those single PIP derived composites, i.e. without this CVI SiC layer, the fibers/interphase are totally exposed to oxidative environments due to the nature of PIP derived matrix that is porous and full of micro-cracks. Worse still, the oxidized products of PIP derived matrix, viscous and sticky SiO 2 , tends to tightly wrap up fibers, forming a strong fiber/matrix bond. On the contrary, for those hybrid CVI-PIP derived composites, the dense CVI SiC layer serves as an oxidation barrier, not only blocking the inward flowing of oxygen to invade interphase/fibers, but also precluding the viscous and sticky SiO 2 reach fiber surface. The superior properties of SiC f /SiC composites produced by hybrid CVI-PIP technique suggest it be a desirable manufacture technique for industrial applications. [ABSTRACT FROM AUTHOR]

Peripheral nerve injury (PNI) and the limitations of current treatments often result in incomplete sensory and motor function recovery, which significantly impact the patient's quality of life. While exosomes (Exo) derived from stem cells and Schwann cells have shown promise on promoting PNI repair following systemic administration or intraneural injection, achieving effective local and sustained Exo delivery holds promise to treat local PNI and remains challenging. In this study, we developed Exo-loaded decellularized porcine nerve hydrogels (DNH) for PNI repair. We successfully isolated Exo from differentiated human adipose-derived mesenchymal stem cells (hADMSC) with a Schwann cell-like phenotype (denoted as dExo). These dExo were further combined with polyethylenimine (PEI), and DNH to create polyplex hydrogels (dExo-loaded pDNH). At a PEI content of 0.1%, pDNH showed cytocompatibility for hADMSCs and supported neurite outgrowth of dorsal root ganglions. The sustained release of dExos from dExo-loaded pDNH persisted for at least 21 days both in vitro and in vivo. When applied around injured nerves in a mouse sciatic nerve crush injury model, the dExo-loaded pDNH group significantly improved sensory and motor function recovery and enhanced remyelination compared to dExo and pDNH only groups, highlighting the synergistic regenerative effects. Interestingly, we observed a negative correlation between the number of colony-stimulating factor-1 receptor (CSF-1R) positive cells and the extent of PNI regeneration at the 21-day post-surgery stage. Subsequent in vitro experiments demonstrated the potential involvement of the CSF-1/CSF-1R axis in Schwann cells and macrophage interaction, with dExo effectively downregulating CSF-1/CSF-1R signaling. Exo-loaded decellularized nerve hydrogels were fabricated by integrating exosomes, PEI, and decellularized nerve matrix for peripheral nerve repair based on improvement of remyelination and disruption of CSF-1R expression. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract A gradient-structured Cu sample composed of grain-size gradient surface layer (GSL) and homogeneous coarse-grained (CG) core was fabricated by surface severe plastic deformation. Microhardness measurements revealed that both tension-induced softening in the top nanograined surface layer and hardening in the subsurface layer of integrated gradient sample were far more pronounced than that of a freestanding GSL, i.e. extraordinary softening and hardening occurred in gradient sample. The synergetic deformation between GSL and CG core produced accumulation of geometrically necessary dislocations and thereby back stress strengthening, resulting in extra flow stress and hardening. The extraordinary softening was attributed to the extra flow stress-assisted grain coarsening in nanograined layer. Furthermore, strain measurements proved that the CG matrix plays critical roles in stabilizing the grain coarsening and homogenizing the strain distribution in nanograined layer, which were favorable for the uniform ductility. [ABSTRACT FROM AUTHOR]

Abstract Austenite stainless steels (ASSs) may suffer from both cold deformation and sensitization prior to hydrogen exposure. There is scant data in literature on the combined effect of prior deformation and sensitization on the hydrogen embrittlement (HE) of ASSs. The present study investigated the combined effects of tensile plastic prestrain (PS) and 650 °C sensitization (ST) on the HE of 304 steel by hydrogen pre-charging and tensile testing. The results are explained by terms of pre-existing α′ martensite content. PS higher than 10% can enhance HE significantly by inducing severe α′ transformation prior to hydrogen exposure. Prior ST also enhances HE, but submitting the prestrained and α′-containing 304 steel to short-time ST can diminish the enhancement of HE by prestraining, as ST can cause the reversion of α′ to austenite, reducing pre-existing α′ content. It is inadvisable to make 304 steel be sensitized/welded firstly and deformed subsequently, even if the ST time is short such as what happens during welding, because this treating sequence can induce more α′ than prestraining alone, enhancing HE more significantly. Apparent hydrogen diffusivity can be related quantitatively to pre-existing α′ content, proving directly that α′ platelets can act as diffusion "highways" in ASSs. It is indicated that pre-existing α′ can enhance subsequently the HE of ASSs is because it can lead to a large amount of hydrogen entering the ASSs during hydrogen exposure by acting as diffusion "highways". HE is enhanced by increasing hydrogen amount rather than by pre-existing α′ itself. Highlights • α′ induced by prestrain higher than 10% enhances significantly HE of 304 steel. • Short-time sensitization can diminish the enhancement of HE by prestrain alone. • Because it can lead to reversion from α′ to γ, reducing pre-existing α′ content. • First sensitization then plastic deformation can enhance HE more significantly. • Hydrogen diffusivity is described quantitatively as a function of α′ content. [ABSTRACT FROM AUTHOR]

Abstract The yttrium heavily doped La 2 Zr 2 O 7 solid solutions coatings, with a Y to La molar ratio of 1:1, have been successfully prepared by air plasma spraying technique. The evolution of phase composition, phase structure and thermal conductivity of such coatings with annealing at 1300 °C has been investigated. The results show that, a single pyrochlore structure can be retained for coating after annealing up to 48 h, beyond which the fluorite phase begins to precipitate out. By comparing thermal conductivities to those undoped counterparts at a similar porosity level, we find a considerably flat thermal conductivity versus temperature (k-T) curve, suggesting the existence of a strong phonon scattering source, which is inferred as rattlers. In addition, after the segmentation of the fluorite phase, the thermal conductivity of corresponding coatings rises considerably, indicating that the fluorite phase has a higher thermal conductivity than that of pyrochlore phase. Moreover, while the as-sprayed coatings show a clear indication of radiative thermal conduction beyond 1000 °C, the thermal conductivity of annealed coatings do not show such an uprising trend after 1000 °C, suggesting that the radiative thermal conduction has been greatly suppressed. The reason is proposed as the formation of local dipoles due to local enrichment of certain elements influences the propagation of electromagnetic waves and thus suppresses the radiative thermal conduction. [ABSTRACT FROM AUTHOR]

Highlights • Hydroxypropylmethylcellulose (HPMC) were hybridised with hydroxypropyl starch (HPS). • The rheological, gel and film properties were tailored by HPMC/HPS contents. • HPS displayed reduced viscosity and increased compatibility with HPMC. • HPS exhibited less chain rearrangement and lower film crystallinity and rigidity. • Starch hydroxypropylation reduced film density and oxygen permeability in blends. Abstract This work investigates the rheology, structure, and properties of novel thermal/cooling-gel biphasic systems formed by hybridization of hydroxypropyl methylcellulose (HPMC) as a thermal gel and hydroxypropyl starch (HPS) as a cooling gel. Due to the different gelation properties, HPS became the dispersed phase in the other continuous phase at low temperatures, and so did HPMC at high temperatures. However, the dispersed phase could play a dominant role in the viscosity, thixotropy, and gel properties of the blends, and subsequently affect the crystalline structure, fractal structure, mechanical properties, oxygen permeability, and thermal stability of the blend films. Moreover, the rheological properties and the film structure and performance could also be varied by the chemical modification of starch. Hydroxypropylation could break the starch intermolecular hydrogen bonding, disrupt its ordered structure, inhibit the molecular rearrangement, and result in a softer gel texture that was more compatible with HPMC. With a higher degree of hydroxypropyl substitution, the resultant blend films were more amorphous and flexible but exhibited decreased mechanical properties and oxygen permeability. The knowledge obtained from this work could provide guidance to further developing various thermal/cooling-gel multi-phasic systems with desired properties and functionality. [ABSTRACT FROM AUTHOR]

Abstract The thermal shock properties of mixed Yb 2 Si 2 O 7 and Yb 2 SiO 5 composite environmental barrier coating (EBC) topcoat, with various Yb 2 Si 2 O 7 -to-Yb 2 SiO 5 ratios, are investigated between room temperature and 1500 °C. The results show that, with more Yb 2 Si 2 O 7 introduced, the mixed Yb 2 Si 2 O 7 and Yb 2 SiO 5 composite topcoats exhibit an increasing thermal shock property. This may be attributed to that, while Yb 2 Si 2 O 7 mole fraction increases, the thermal expansion coefficient of the mixed Yb 2 Si 2 O 7 and Yb 2 SiO 5 composite ceramics becomes smaller, more matched to substrates and the fracture toughness of the mixed Yb 2 Si 2 O 7 and Yb 2 SiO 5 composite ceramics becomes larger, both of which are favoring the improvement of thermal shock resistance. Highlights • Yb 2 Si 2 O 7 and 3Yb 2 Si 2 O 7 •Yb 2 SiO 5 exhibit better durability compared with other EBC samples. • TEC and fracture toughness for five compositions of ytterbium silicates have been studied. • The failure mechanisms are probably unveiled as TEC and TGO. [ABSTRACT FROM AUTHOR]

The poor fracture toughness limits the wide application of the cubic lanthanum zirconate (La 2 Zr 2 O 7 ) ceramics. The current study reports a dramatic fracture toughness improvement of lanthanum zirconates by the introduction of lanthanum aluminates (LaAlO 3 ), a ferroelastic second phase. A composite ceramic with the composition of x LaAlO 3 / (1- x ) La 2 Zr 2 O 7 , where x  = 10, 20, 30, 40, 50 mol%, has been fabricated by a spark plasma sintering method. It is found that, the ferroelastic domains of LaAlO 3 in x LaAlO 3 /(1- x )La 2 Zr 2 O 7 composite ceramics clearly switch towards a direction that is normal to a propagating crack. In addition, the processing zone width of ferroelastic domains is found to decrease with an increase of LaAlO 3 inclusion, attributing to that the residual tensile stress in LaAlO 3 caused by the thermal expansion coefficient mismatch, which helps to expand the processing zone, decreases with more LaAlO 3 included. [ABSTRACT FROM AUTHOR]

• An optimum grain size (d o p t i m u m) on the order of a few micrometers exist ubiquitously for strength-ductility synergy, at which the strain energy density limit reaches a maximum while maintaining high yield strength. • Theoretical models on the grain size-dependence of uniform elongation and ultimate strength are developed, which accurately predict the d o p t i m u m. • The d o p t i m u m ≈ 2 l G b a r , where l G b a r ≈ k H P R 3 / 2 2 M G b is the characteristic width of grain boundary affected region. • The d o p t i m u m is the critical grain size having the strongest intragranular plastic strain gradient effect. • The d o p t i m u m is the limiting dimension that allows toughening by grain refinement. A strength-ductility trade-off usually occurs when grains are refined to increase strength. A question arises on if there exists a grain size for the best strength-ductility combination, i.e., with the highest possible strain energy density limit and strength simultaneously. This issue is crucial for guiding the design of strong and tough structural materials. Here we reveal an optimum grain size (d o p t i m u m) on the order of a few micrometers, at which the strain energy density limit, estimated as the product of strength and uniform elongation, reaches a maximum while maintaining reasonably high yield strength. The d o p t i m u m is found to exist in a series of single-phase FCC, BCC and HCP materials, indicating it as a universal phenomenon. Theoretical models on the grain size-dependence of uniform elongation and ultimate strength are developed by considering dislocation accumulation in grain boundary affected region (Gbar) and grain interior based on the classical Kocks-Mecking-Estrin model. Combined with the Hall-Petch relationship, the models accurately predict the d o p t i m u m. Importantly, the models disclose this d o p t i m u m to be close to twice of the characteristic width of Gbar (l G b a r), suggesting that it is exactly at or near the critical grain size with the strongest intragranular strain gradient effects. [Display omitted] [ABSTRACT FROM AUTHOR]

The effect of back stress on the mechanical behaviors of heterogeneous material is studied in two modeled heterogeneous laminates, i.e. laminated structure with a nanostructured (NS) Cu-Zn alloy layer sandwiched between two coarse-grained (CG) pure Cu layers. The improved tensile ductility of NS layer is revealed and attributed to the constraint from the stable CG layers. It is found that the elastic/plastic interaction between NS and CG layers is capable of significantly improving the back stress, which makes a significant contribution to the synergetic strain hardening in low strain stage. Furthermore, a higher mechanical incompatibility permits stronger and longer mutual interaction between layers, i.e. coupling effect, which contributes to a higher back stress. These results improve our understanding about the role of back stress on mechanical behaviors of heterogeneous laminate materials. [ABSTRACT FROM AUTHOR]

We study problems associated with seismic data decomposition and migration imaging. We first represent the seismic data utilizing Gaussian beam basis functions, which have nonzero curvature, and then consider the sparse decomposition technique. The sparse decomposition problem is an l 0 -norm constrained minimization problem. In solving the l 0 -norm minimization, a polynomial Radon transform is performed to achieve sparsity, and a fast gradient descent method is used to calculate the waveform functions. The waveform functions can subsequently be used for sparse Gaussian beam migration. Compared with traditional sparse Gaussian beam methods, the seismic data can be properly reconstructed employing fewer Gaussian beams with nonzero initial curvature. The migration approach described in this paper is more efficient than the traditional sparse Gaussian beam migration. [ABSTRACT FROM AUTHOR]

The poor fracture toughness of La 2 Zr 2 O 7 hinders its practical application as a thermal barrier coating topcoat material. To toughen La 2 Zr 2 O 7 , metastable tetragonal 8 wt% yttria-stabilized zirconia ( t ’-8YSZ), has been introduced into the La 2 Zr 2 O 7 matrix by plasma spray quenching of 8YSZ powders and spark plasma sintering. An evident fracture toughness improvement has been achieved due to ferroelastic domains switching. The resulting toughness increase has a quadratic relationship with t ’ phase volume fraction below a critical value (30 vol%), beyond which it is far smaller to what expected owing to the residual stress being smaller than the ferroelastic coercive stress. [ABSTRACT FROM AUTHOR]

Solid-liquid equilibrium (SLE) of Na + //Cl − , NO 3 − , SO 4 2− -H 2 O quaternary system at 373.15 K was determined via isothermal solubility equilibrium method. The dry-salt phase diagram and the tri-prism stereogram of this system were obtained found on the solubility data. Without any solid solutions or double salts, the phase diagram is the simplest one of the quaternary system, consisting of one invariant point, three univariant curves, three crystallization fields of single salts, three cocrystallization fields for two salts and one cocrystallization field for three salts. At the same time, the physicochemical properties (density and conductivity) of this system were measured in the experiment. Moreover, comparing with the equilibrium phase diagrams in the temperature range from 258.15 K to 373.15 K, it could be found that the crystallization field of the double salt D (NaNO 3 .Na 2 SO 4 .10H 2 O) reduces with the temperature increases, and disappears at 373.15 K. With the growing temperature, the crystallization field of Na 2 SO 4 enlarges while the crystallization fields of NaNO 3 and NaCl both reduce. All above the experimental results obtained can be applied to solve the salt separation of the relative brine system mainly containing the four aforementioned ions as well as conduct further theoretical studies. [ABSTRACT FROM AUTHOR]

For the unconfined natural gas hydrate deposits in Shenhu area, in-situ electrical heating methods are proposed to assist depressurization for promoting gas production, such as wellbore and low-frequency electrical heating (WBEH, LFEH). To determine the optimal exploitation method, three LFEH assisted depressurization schemes are designed under dual horizontal wells in this work, whose recovery performances are compared with only depressurization (OD) and WBEH through numerical simulations. Results indicate that LFEH significantly promotes hydrate dissociation and gas production, leading to a halved exploitation time of the two-wells depressurization scheme compared with OD. Besides, the brine flooding scheme recovers more gas and net energy over OD (16.6% and 25.2% higher, respectively) by the enhanced heat convection, validating the potential of LFEH for developing the unconfined hydrate deposits. However, the LEFH huff-puff method does not show obvious superiority over OD due to the reduction of net production time. In addition, more uniform heat distribution of LEFH leads to much lower formation temperature than WBEH, which can avoid wellbore instability by continuous high temperature. Finally, sensitivity analyses show that low-frequency electrical heating should be terminated in advance to avoid unnecessary energy waste and increasing electrical heating power is beneficial to gas and energy recovery. • Low-frequency electrical heating (LFEH) is proposed to develop the unconfined hydrate deposits. • The feasibility of LFEH is verified by numerical simulations. • LFEH is compared with wellbore electrical heating. • Sensitivity analyses of heating parameters on production and costs are conducted. [ABSTRACT FROM AUTHOR]

[Display omitted] • A heterostructure in CrCoNi alloy with nanograins dispersed around coarse-grains in size of a few micrometers is prepared. • It is fabricated by cold-rolling followed by sequential flash-annealing at increasing temperatures. • It is as strong as recovered nanostructure and at the same time as ductile/tough as homogeneous coarse-grains. • Hetero-zone interaction activates strain partitioning, mechanical twinning and long-range internal stress development, resulting in a multistage work hardening. • A strategy to retain ductility/toughness at ultrahigh strength: deploying dispersed heterostructrure and manipulating the grain size of soft zone. Here we advocate the strategic design of dispersed heterostructure to retain ductility and toughness in high-strength metals, using the equiatomic CrCoNi alloy as an example. Dispersed heterostructure, with nanograins and/or ultrafine grains (the hard zone) dispersed around micrometer-sized grain (the soft zone), is fabricated by cold-rolling followed by sequential flash-annealing at increasing temperatures. It displays a decent uniform elongation of ∼ 20 % and an exceptional strain energy density limit up to ∼ 240 mJ/mm3 at the strength level of ∼ 1.2 GPa, which is unattainable by its homogeneous as well as clustered heterogeneous counterparts. Grain size-dependent heterogeneous deformation evokes inter-zone interactions, which induce strain partitioning, activate additional mechanical twinning and promote developments of dislocation gradient and long-range internal stress near zone boundary sequentially, imparting a multistage work hardening with extraordinary strain hardening rate up-turn followed by slow attenuation. Dispersed heterostructure provides a higher density of zone boundary, ensuring more extensive inter-zone interaction and thus maximizing the extraordinary strain hardening to improve ductility. [ABSTRACT FROM AUTHOR]

Edible films from the blending hydroxypropyl methylcellulose (HPMC) with hydroxypropyl starch (HPS) have been developed. This work focuses on the relationship between morphologies and mechanical properties of such systems. To aid understanding of blend morphology, a new technique used to identify the two phases through dying of the HPS by iodine has been developed, which provided a simple and convenient way to clearly distinguish between HPMC and HPS phases. It was found that the blend system is immiscible and there is phase transition point depending on blending ratio and solution concentration. The lower transparency point of the blend and phase transition reign of HPMC from continuous phase to separated phase correspond with the variation of tensile modulus. The modulus and elongation decreased with increased solution concentration, which is correlatable with the morphologies present, where it was found that the HPMC gradually changed from a continuous phase to a distinct phase. [ABSTRACT FROM AUTHOR]

The electric double layer capacitances for a series of titanium dioxide based composite nanotube-arrays (TNTAs, Pt/TNTAs, CdS/TNTAs, CdS/Pt/TNTAs) in aqueous solutions were examined at the polarized potential. As a result, the capacitance increases with a decrease in the ac-frequency, obeying the inverse of the power law of the frequency. The power law is demonstrated to be equivalent to the constant phase element. The intensity of frequency dispersion varies with nanoarrays as to different nano architectonics and materials. The CdS coated TNTAs yield the largest specific capacitance of 2.33 mF cm − 2 at a frequency of 1 Hz, which is about 9 times higher than the capacitance obtained from bare TNTAs at the same condition. The coating of Pt, however, shows less capacitive behavior with more obvious frequency-dispersion. [ABSTRACT FROM AUTHOR]

The miscibility between two gels with largely different gelation behaviors is an interesting topic both scientifically and practically. This paper reports a novel bi-phasic system based on two natural polymers, hydroxypropyl methylcellulose (HPMC) which has a thermal gelation behavior, and hydroxypropyl starch (HPS) which has a cooling gelation property. While both biopolymers have the same glucose unit grafted with propylene oxide, and are compatible to a certain degree, they were observed immiscible because of their different gelation behaviors. The immiscibility of these two compatible polymers could result in special structures leading to different blend film properties. Regarding this, the morphology, thermal transition, mechanical properties and oxygen barrier property could be well tailored by the ratio of two biopolymers and the environmental conditions. The knowledge obtained from this work could be useful for understanding other similar systems with desirable structure and properties. [ABSTRACT FROM AUTHOR]

[Display omitted] Heterostructured metals possess superior mechanical properties exceeding the prediction by the rule-of-mixtures. However, it remains a challenge to understand the key microstructural factor that controls the extra work hardening. Here aided by a newly developed mechanism-based plasticity model that incorporates the constitutive law of the back stress induced by zone-scale deformation heterogeneity, we reveal that the hetero-zone boundary affected region (Hbar) plays the key role in controlling the synergistic mechanical responses of heterostructure. Specifically, the Hbar, characterized by high strain gradient with a constant characteristic width, is formed to coordinate inter-zone deformation heterogeneity. The extra work hardening originates primarily in the Hbar, where the accumulation of geometrically necessary dislocations develops back stress and forest hardening. Importantly, the extra work hardening increases proportionally with Hbar volume fraction, and the best strength-ductility combination is reached when Hbar approaches saturation. In addition, the influences of zone configuration, mechanical incompatibility, and zone volume fraction on Hbar effect are analyzed, which sheds light on potential strategies to enhance the Hbar effect for optimizing strength-ductility combination. [ABSTRACT FROM AUTHOR]

Mycotoxins are chemicals with diverse toxicities that are produced by fungi. Aflatoxin B1 is commonly found in plant food, and is generally regarded as one of the most toxic mycotoxins. In the present study, pregnant ICR mice were given p.o. daily doses of aflatoxin B1 at 0, 0.05, 0.5, 5 mg/kg for 4 days (from E13.5 to E16.5). Compared to the control group, time of delivery was shortened and low birth weight was induced in mice treated with 0.5 and 5 mg aflatoxin B1/kg, respectively. Placental tissue isolated from pregnant mice at E17.5 showed that the mRNA expression of crh was increased in aflatoxin-treated groups. This upregulation might signify premature delivery. Further analysis indicated that Pkc proteins were activated and Bcl-2 was reduced in the placental tissue of the aflatoxin-treated groups. Reduction of the anti-apoptotic proteins, on the other hand, might affect the morphorgenesis and maintenance of the placenta. [ABSTRACT FROM AUTHOR]

Hydrogen-assisted cracking (HAC) is a coupled phenomenon between crack growth rate and hydrogen diffusion to the region ahead of crack tip. To understand the cracking mechanism and to control or predict the HAC rate, knowledge of hydrogen diffusion around a crack tip is essential. Metastable austenitic stainless steels can be severely embrittled by hydrogen due to strain-induced α′ martensite transformation around crack tip, as the hydrogen diffusivity in α′ martensite is much higher than in γ austenite while the solubility is lower. However, the effect of induced α′ martensite on local diffusion of hydrogen around a loaded crack tip has not been intuitively demonstrated. This study first reveals the quantitative relations of hydrogen diffusivity and solubility with induced α′ martensite amount, and then performs FE analysis of hydrogen diffusion around a crack tip in a 304L ASS cylinder storing high pressure gaseous hydrogen with considering the combined effect of α′ martensite transformation and hydrostatic stress on diffusion. The hydrostatic stress exhibits a peak value at a distance away from crack tip, while the peak α′ martensite volume fraction locates at the crack tip. Compared to the analysis only considering stress effect, the presence of induced α′ martensite can not only significantly accelerate the hydrogen transport to the critical region ahead of crack tip, but also markedly elevate the level that the peak hydrogen concentration reaches. The peak hydrogen concentration doesn't locate at the peak hydrostatic stress site as generally expected, but at the site in the γ austenite-rich region abutting the α′ martensite-rich region at crack tip vicinity, because this site possesses very high hydrogen solubility and close to the high hydrogen diffusivity region, consequently accommodating the hydrogen getting off the α′ martensite diffusion “highway”. [ABSTRACT FROM AUTHOR]

China has undergone a dramatic transition echoed the unprecedented urbanization and economic growth since the late 1970s. The current research on urbanization has overlooked the transformation consistency between urban and rural areas. Although the Chinese central government has focused on improving rural residents' livelihood, it is still far from achieving coordinated urban–rural development. This paper provides a comprehensive assessment of China's urban–rural development transformation (URDT) based on three indicator systems, namely the urban–rural development level (URDL), the urban–rural structure level (URSL), and the urban–rural coordination level (URCL). Findings from this investigation show that universal and intense URDT has taken place in China over the last two decades. This has been accompanied by growth of URDL and URSL and deterioration of URCL. There are, however, obvious spatial disparities in the different aspects of URDT. The western and northeastern regions of China have experienced slower transformation than other regions between 1990 and 2010. Correlation analysis among the sub-index shows that coordinated urban–rural development needs a certain initial socioeconomic level and moderate changes of URDL and URSL. This paper suggests that more attentions should be paid to rural areas and lagging areas in central and western China. Given the regional disparities of URDT, the most effective way to achieve urban–rural integration in China is by taking the overall considerations of development policies of both region and urban–rural areas aimed at various urban–rural development transformation characteristics. [ABSTRACT FROM AUTHOR]

Well-dispersed Pt quantum dots (QDs) with an average diameter of 2 nm were homogeneously decorated on TiO 2 nanotube arrays (TNTAs) by a modified photo irradiation–reduction method. The effect of the precursor concentration between 0.3 mM and 2.0 mM on the decorated Pt QD content was investigated. The synthesized nanostructures with different Pt QD contents were characterized by XRD, SEM, TEM, XPS, UV–vis and PL. The Pt QDs, acting as electron sinks, reduced the recombination of electrons and holes and extended their lifetime, leading to a greatly enhanced photocatalytic performance. In a 1.0 mM concentration, the fabricated nanocomposite with excellent durability exhibited favorable photocurrent density and efficiency of degrading Rhodamine B. According to EPR analysis, the corresponding mechanism of the UV-driven photocatalytic process is proposed. Furthermore, the nanocomposite is easier to be recycled compared to the powder catalysts. [ABSTRACT FROM AUTHOR]

The gelation process in Polyacrylonitrile (PAN)/Dimethyl Sulfoxide (DMSO)/Water (H 2 O) systems was studied by rheology. Chambon–Winter criterion was used to detect the critical gelation temperature variation. Interestingly, we found that the loss tangent coincided at two different temperatures in different frequency periods with the temperature decreased. By using the physical and mathematical analysis, we were able to tell that the first one was the critical sol–gel transition temperature, which appeared at higher temperatures under lower frequencies; and the second point was an indication of another self-similar structure, which appeared at lower temperatures under higher frequencies. We analyzed the coarsening mechanism in the gelation process of ternary blends, and considered that the volume growth of the physical linkage can interpret this unusual phenomenon. A ‘Joint Point to Joint Section’ model, similar to nucleation process, was proposed to interpret the mechanism of the growth of the physical linkages. Based on the above data, phase boundaries of critical gel and the second self-similar structure can be drawn. As the PAN or water content increased, both transition temperatures increased, which indicated the non-solvent water favored the aggregation of PAN molecules and promoted the forming of the second self-similar structure. [ABSTRACT FROM AUTHOR]

[Display omitted] • Simultaneous NH 4 +/NO 3 – removal was achieved in a PADB system. • Synergistic NH 4 +/NO 3 – removal occurred through Anammox/nitrification and PAD. • Sulfur and iron cycles in the PADB system reduced their effluent production. • Ferritrophicum , Thiobacillus, and Candidatus_Brocadia were found in PADB. Pyrite is one kind of cost-effective electron donors for nitrate denitrification. In this study, a pyrite-driven autotrophic denitrification biofilter was applied for simultaneous removal of NH 4 + and NO 3 – over the 150-day. The influent NH 4 +/NO 3 – ratio (0.3–1.7) had less effect on system performance, while for the hydraulic retention times (HRTs, 24–3 h), the removal percentage of both > 90% and removal loading rates of 52.8 and 59.4 mg N/(L·d) for NH 4 + and NO 3 – removal were obtained at the HRT of 6 h. The 16S rRNA genes analysis showed that Ferritrophicum , Thiobacillus , Candidatus_Brocadia , and unidentified_Nitrospiraceae were predominant. Analyses of nitrogen and sulfur metabolism showed that ammonia was removed by complete nitrification, nitrate was reduced to N 2 , and sulfide was oxidized to sulfate. Dynamics of pollutants within the reactor and microbial activity showed nitrification/Anammox and pyrite-driven autotrophic denitrification were responsible for the synergistic removal of NH 4 +/NO 3 – in this system. [ABSTRACT FROM AUTHOR]

• Hydroxypropyl methylcellulose (HPMC) was blended with hydroxypropyl starch (HPS) • The continuous phase of HPMC-HPS mixed hydrocolloid changed with HPMC/HPS ratio. • Hydroxypropylation promoted HPMC gelation. • Good compatibility between HPMC and HPS enhanced the HPMC-HPS gel strength. • HPMC hydroxypropylation improved the oxygen barrier effect of HPMC-HPS film. This work investigates the structure, processability, and film performance of hydroxypropyl methylcellulose (HPMC) hydrocolloids affected by hydroxypropy substitution degree and blending with hydroxypropyl starch (HPS). The hydroxypropylation of HPMC could increase inter-chain hydrogen bonding, thereby promoting its gelation, and improve film-forming, but reduce the mechanical properties of the films. HPMC-HPS mixed hydrocolloid system showed a typical "sea-island" morphology with the continuous phase changing with blend ratio. The content of hydroxypropy groups of HPMC affected the compatibility between HPMC and HPS, the morphology of the discrete phase, and the rheological properties of the blends. The fluid-like HPS enhanced the gel strength of HPMC when they had better compatibility. With a higher degree of hydroxypropy substitution, blend films exhibited a much denser structure, better oxygen barrier property, and appropriate mechanical properties. The knowledge obtained from this work could guide the development of edible packaging materials with desired properties and functionality. [ABSTRACT FROM AUTHOR]

In this study, we consider the inexact Newton method using the trust-region and line search globalization strategies when solving the large-scale full waveform inversion problem. An elaborate stopping criterion or forcing term is introduced in order to avoid oversolvings of Newton equation. We develop an efficient method to compute (pseudo) Hessian vector products. In addition, a diagonal preconditioner based on the pseudo-Hessian approach is employed to further accelerate the solution of Newton equation. We discuss the specific parameter choices for these present methods. Numerical experiments based on the Marmousi2, BP 2004, and Sigsbee models are conducted to show the numerical performance of proposed inexact Newton methods. Numerical experiments demonstrate that the trust-region can perform better than the line search globalization strategy in the presence of nonlinearity and nonconvexity of the full waveform problem, especially for high contrast velocity models. • Inexact Newton methods with the trust-region and line search are analyzed. • A new method for efficiently computing the Hessian-vector products is presented. • A stopping criterion is proposed to avoid oversolvings of Newton equation. • Specific parameter choices for these methods are discussed. [ABSTRACT FROM AUTHOR]

Aflatoxins pose a major threat to food safety. These toxins are classified as hepatocarcinogens; however, their effect on the other tissues is unclear. During pregnancy, the fetus and placental tissues are especially sensitive to toxin exposure. In the present study aflatoxin B1 was found to induce the mRNA expression of corticotrophin-releasing hormone (CRH) in placental cells. A corresponding increase in CRH peptide in the culture medium was also observed. Since signal transduction pathways have been described previously in the control of CRH transcription, the status of protein kinase Cs (PKCs) and mitogen-activated protein kinases (MAPKs) were determined by Western analysis. In the aflatoxin B1-treated cultures, PKC α/βII/δ and ERK-1/2 were activated. As the PKC inhibitor bisindolylmaleimide I and the ERK inhibitor PD98059 could revert the induced CRH expression, the pathways dictated by PKC and ERK were likely involved in the transcriptional regulation. Electrophoretic mobility shift assay showed that C/EBP could be the ultimate activated transcription factor. Taken together, this study demonstrated that aflatoxin B1 could increase the parturition-related placental hormone in vitro . These findings might have significant implications for public health. [ABSTRACT FROM AUTHOR]

CdS quantum dots (QDs) have been successfully deposited on TiO 2 nanotube arrays (TNTAs) by successive ionic layer adsorption and reaction (SILAR) method for visible-light-driven hydrogen production and organic compound degradation. The composition, morphology and optical property have been characterized by the X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV–vis absorption spectra. The loading amount of CdS can be adjusted by controlling the deposition cycles which demonstrates correspondingly optical behaviors. CdS-TNTAs sample prepared by SILAR deposition with 15 cycles gives the highest hydrogen production rate of 1.89 μmol h −1 cm −2 for 15 mL solutions and the highest degrading rate. Moreover, a transfer mechanism of photo-generated electrons on CdS-TNTAs during the visible-light photocatalytic process is proposed based on the experimental analysis. Furthermore, the prepared sample has good stability and can be more easily reused than the powder catalyst. [ABSTRACT FROM AUTHOR]

A series of yttrium-doped lanthanum zirconate (La 1−x Y x ) 2 Zr 2 O 7 (0 ≤ x ≤ 1) bulk samples were prepared and their ionic conductivities were studied by impedance spectroscopy. It is found that intermixing of Y and La ions increases the conductivity of the end members pyrochlore-type La 2 Zr 2 O 7 and fluorite-type Y 2 Zr 2 O 7. Highest conductivity which is 2–3 orders of magnitude higher than that of La 2 Zr 2 O 7 and Y 2 Zr 2 O 7 is achieved in a two-phase sample which consists of both pyrochlore and fluorite phases. The enhanced conductivity in the two-phase sample is attributed to the presence of the pyrochlore-fluorite phase boundary, which has higher conductivity than the pyrochlore and the fluorite phase grains. The effect of the conductive phase boundary has been confirmed by a 2-dimensional finite element modelling. [ABSTRACT FROM AUTHOR]

The effect of the pre-strain on hydrogen embrittlement (HE) of high strength steels was investigated by slow strain-rate tensile (SSRT). The specimens were electrochemically hydrogen-charged in 0.5 mol/L H 2 SO 4 with 1 g/L CH 4 N 2 S at room temperature for 24 h. It is found that the amount of hydrogen increases linearly with the exponent of pre-strain, i.e., C H = 11.963 + 0.00385 exp ( 1.144 ε P ) . The HE susceptibility of the alloy initially decreases and then increases with increasing pre-strain. The ultimate tensile strength for the hydrogen-charged specimen is highest in the 3% pre-strain, which is interpreted by competition between strain hardening and Hydrogen Enhanced Decohesion (HEDE) mechanism. The fracture mode shows a mixed mode fracture of quasi-cleavage and intergranular fracture for hydrogen-charged specimens while the fracture mode exhibits dimples for hydrogen-free specimens. [ABSTRACT FROM AUTHOR]

Prior plastic deformation introduced by fabrication process such as cold working is an important factor for hydrogen embrittlement (HE) of austenitic stainless steels. In order to clarify the relationship between HE susceptibility of type 304L stainless steel and prior tensile plastic deformation, a group of flat specimens with different degrees of pre-strain (0 i.e. without pre-strain, 3, 6, 10, 15, 20 and 25% true strain) was catholically hydrogen charged and then was strained immediately to fracture by means of tensile testing. The resulting tensile properties and fracture morphologies were compared with those of a second reference group of specimens without charging. The results reveal a detrimental effect of high degrees of pre-strain on HE of the steel. When the pre-strain was less than 6%, the effect of pre-strain on HE of the steel was minor. While when the pre-strain was higher than 10%, the pre-strain greatly enhanced HE of the steel. This occurrence could be attributed to strain-induced α′ martensite transformation during pre-straining. The higher the pre-strain, the higher the content of α′ martensite transformed and so the HE occurred. Fracture morphology investigations suggest that the pre-strain-induced α′ martensite greatly enhanced the hydrogen diffusivity, and the mode of brittle fracture due to hydrogen strongly depended on the pre-strain level. [ABSTRACT FROM AUTHOR]

• A program was developed to analyze the fruit motion in high-speed videos. • Most litchi fruit were detached at quasi-static tilting test without traction. • Stress exceeding ultimate stress was a main detachment reason. • Inducing large tilting angles was advantageous for increasing detachment speed. A high-speed camera was used to study the motions of litchi fruit during vibrational harvesting to investigate fruit detachment patterns. The quasi-static traction and tilting tests, as well as vibrational detachment tests using frequencies of 9, 12 and 15 Hz and amplitudes of 100 and 130 mm, were conducted on 'Huaizhi' litchi. A MATLAB program was developed to estimate the motion parameters of the fruit during shaking. The quasi-static tests indicated that the detachment force decreased as the tilting angle increased from 0° to 60° and that most fruit would detach at a certain tilting angle (average value of 62.6°) without traction. The vibrational detachment tests suggested two main reasons for fruit detachment: the stress exceeded the ultimate stress at the fruit–stem junction and fatigue induced by the alternating stress at the junction. Inducing a large tilting angle during shaking was advantageous for creating a high degree of stress at the fruit–stem junction and for achieving a high detachment speed. In general, appropriate increases in the vibration amplitude and frequency decreased the degree of fruit damage by causing fewer impacts. In this study, 12 Hz/130 mm and 15 Hz/100 mm were the optimal parameter combinations to achieve limited litchi fruit damage and high detachment speeds. [ABSTRACT FROM AUTHOR]

• The NS surface layer supported by CG substrate displays significant strain delocalization and achieves improved uniform elongation. • The strain delocalization is realized by forming dispersed stable strain bands (SBs) and promoting the deformation of non-strain banding zone. • The intra-layer microstructure inhomogeneity and the limited strain hardening capability of intra-layer domains lead to SBs nucleation. • The inter-layer microstructure inhomogeneity causes extra inter-layer shear constraints, which stabilize SBs and promotes the deformation of non-strain banding zone. • The NS indeed becomes ductile, due to the extensive nanotwinning and dislocation activity enabled by strain delocalization. How to suppress strain localization in tensioned nanograined layer and make it ductile? This remains a great challenge. Here we explore the effects of microstructure inhomogeneity on the plastic behavior of nanostructured layer. A nanostructured CrMnFeCoNi high entropy alloy layer supported by coarse-grained substrate (in gradient architecture) is taken as an example. In the tensile deformation, strain examinations find that the nanostructure layer experiences significant strain delocalization by activating dispersed stable strain bands (SBs) and promoting the deformation of non-strain banding zone. Finite element analysis reveals that it is the intra-layer microstructure inhomogeneity which enables dispersed SBs nucleation from the mechanical weak sites. The inter-layer microstructure inhomogeneity introduces extra shear constraints from the coarse-grained substrate, which stabilizes SBs and improves the stress of non-strain banding zone, thereby suppressing the early catastrophic strain localization. Importantly, the strong nanostructure layer indeed becomes ductile (enables further work hardening) due to the activation of hierarchical nanotwinning and dislocation activity. [Display omitted] [ABSTRACT FROM AUTHOR]

Polymer-derived SiC fibers are critical structural and functional materials for high-temperature applications, whose service performance can be further improved by introduction of certain heterogeneous elements. Herein, flexible and thermal stable SiC fiber mats were prepared from boron-doped polyaluminocarbosilane (PACS) precursor by electro-spinning, curing and pyrolysis. Two boron-containing compounds o-carborane (oCB) and phenylboronic acid (PBA) were used as the boron sources and their effects on the properties and structure of the SiC fiber mats were investigated. The introduced oCB and PBA had obviously improved the ceramic yield of the cured fiber mats and the flexibility of the SiC fiber mats. However, PBA introduced more boron, but also more oxygen, which leaded to formation of more amorphous SiC x O y phases. Although only a small amount of boron was introduced by oCB, a more significant improvement in the thermal stability of the SiC fiber mat was obtained. This work provided a practical approach for fabrication of flexible and thermally stable SiC fiber mats. [ABSTRACT FROM AUTHOR]

The low strength of pure Ti significantly limits its biomedical applications, although its biocompatibility is the best. Here, by controlled annealing and cryogenic drawing after rolling, we synthesize a set of pure Ti combining the strength of ultrafine-grained Ti and the ductility of coarse-grained Ti. The microstructure is characterized with fine grains (a few microns), abundant twins, and high dislocation density, which enable both short dislocation-slip path for strengthening and enough defects accumulation room for work hardening. Twins provide strengthening due to the subdivision effect of twin lamella on grains and dislocations accumulation near the twin boundaries. High flow stress helps to activate FCC phase transformation at large-strain stage. The excellent ductility is originated from the sustained work hardening enabled by the initial texture, fine grains, the interaction among dislocations, FCC lamellae, and twins. [ABSTRACT FROM AUTHOR]

Understanding the inter-zone interaction-dependent mechanical behavior of constituent zones in heterostructured material is fundamental but challenging. Here we report quantitative investigations on the mechanical response of a nanostructured Cu-10Zn layer constrained by coarse-grained Cu layers in a laminate. The nanostructure layer displays large uniform elongation, moderate work hardening but gradually reduced engineering stress. Such unique responses are primarily attributed to the inter-layer constraint, which leads to the formation of dispersed stable strain bands and thus enables extensive activation of mechanical twinning and stacking faults. These findings provide new insights into the deformation and load-bearing mechanisms of heterostructures. [Display omitted] [ABSTRACT FROM AUTHOR]

β-Amyloid (Aβ) triggered proteopathic and immunopathic processes are a postulated cause of Alzheimer's disease (AD). Monomeric Aβ is derived from amyloid precursor protein, whereupon it aggregates into various assemblies, including oligomers and fibrils, which disrupt neuronal membrane integrity and induce cellular damage. Aβ is directly neurotoxic/synaptotoxic, but may also induce neuroinflammation through the concomitant activation of microglia. Previously, we have shown that furosemide is a known anthranilate-based drug with the capacity to downregulate the proinflammatory microglial M1 phenotype and upregulate the anti-inflammatory M2 phenotype. To further explore the pharmacologic effects of furosemide, this study reports a series of furosemide analogs that target both Aβ aggregation and neuroinflammation, thereby addressing the combined proteopathic-immunopathic pathogenesis of AD. Forty compounds were synthesized and evaluated. Compounds 3c , 3g , and 20 inhibited Aβ oligomerization; 33 and 34 inhibited Aβ fibrillization. 3g and 34 inhibited the production of TNF-α, IL-6, and nitric oxide, downregulated the expression of COX-2 and iNOS, and promoted microglial phagocytotic activity, suggesting dual activity against Aβ aggregation and neuroinflammation. Our data demonstrate the potential therapeutic utility of the furosemide-like anthranilate platform in the development of drug-like molecules targeting both the proteopathy and immunopathy of AD. [Display omitted] • Five series of furosemide analogs were synthesize. • Activities against Aβ aggregation were optimized. • Two novel furosemide analogs concurrently inhibit both Aβ aggregation and neuroinflammation. • A known non-CNS drug was used as a starting point in the development of a novel AD therapeutic. [ABSTRACT FROM AUTHOR]

Here the combination of synergistic strengthening and strain delocalization effects is realized in high-manganese steel by gradient microstructure designing, which results in an excellent strength-ductility synergy. Specifically, the gradient structure consists of two gradient surface layers sandwiching a coarse-grained center. Hardness and microstructure examinations reveal that the synergistic strengthening is originated from the enhanced twinning behavior and extra work hardening in gradient layers. The formation of dispersed strain concentration bands is found in the nanostructured surface layer, which evolves steadily and undertakes large applied strain, thereby leading to delocalized straining response. The formation and stabilization mechanisms of strain concentration bands are analyzed in depth with respect to the microstructure gradient. These findings shed light on the deformation fundamentals of gradient structure, especially on the hetero-deformation induced effects. [ABSTRACT FROM AUTHOR]

[Display omitted] Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized, in part, by the misfolding, oligomerization and fibrillization of amyloid-β (Aβ). Evidence suggests that the mechanisms underpinning Aβ oligomerization and subsequent fibrillization are distinct, and may therefore require equally distinct therapeutic approaches. Prior studies have suggested that amide derivatives of ferulic acid, a natural polyphenol, may combat multiple AD pathologies, though its impact on Aβ aggregation is controversial. We designed and synthesized a systematic library of amide derivatives of ferulic acid and evaluated their anti-oligomeric and anti-fibrillary capacities independently. Azetidine tethered, triphenyl derivatives were the most potent anti-oligomeric agents (compound 2i : IC 50 = 1.8 µM ± 0.73 µM); notably these were only modest anti-fibrillary agents (20.57% inhibition of fibrillization), and exemplify the poor correlation between anti-oligomeric/fibrillary activities. These data were subsequently codified in an in silico QSAR model, which yielded a strong predictive model of anti-Aβ oligomeric activity (κ = 0.919 for test set; κ = 0.737 for validation set). [ABSTRACT FROM AUTHOR]

It is common to hybridize biopolymers for developing materials with combined properties or functionality. However, biopolymers are usually not fully compatible despite their chemical similarity, posing challenges to create mixed systems. Herein, we investigated how the gelation behavior and rheological properties of hydroxypropyl methylcellulose (HPMC), a thermal gel, and hydroxypropyl starch (HPS), a cooling gel, affect their miscibility and the phase structure of their mixed system. The dependence of the zero-shear viscosity for HPMC/HPS paste on biopolymer concentration in a double-logarithmic coordinate can be divided into two parts with the slopes being 11.9 and 2.8 respectively, indicating different degrees of intermolecular entanglement. A typical "sea-island" morphology was shown in the blends, and the phase structure (continuous or discrete) changed with varying HPMC/HPS blend ratio and temperature. This phase structure change can be well correlated to rheological parameters such as zero-shear viscosity, loss tangent, complex viscosity, and the Arrhenius equation correction coefficient (α). Biopolymer concentration, HPMC/HPS ratio, and temperature together controlled rheological properties and phase distribution for the mixed system. The relationship between rheological behavior and phase structure for HPMC/HPS understood from this work provides an insight into designing mixed biopolymer systems with desirable processability, structure, and properties. Image 1 • Hydroxypropyl methylcellulose (HPMC) and hydroxypropyl starch (HPS) mixture studied. • Strong rheological and gelation effects on the phase structure of HPMC/HPS shown. • HPMC/HPS blend ratio and temperature controls continuous/discrete phase change. • Phase structure correlated to zero-shear viscosity and Arrhenius coefficient α. • A schematic model to describe the temperature-induced conformational change. [ABSTRACT FROM AUTHOR]