Microglia,the resident immune cells of the central nervous system,exhibit a wide array of functional states,even in their so-called“homeostatic”condition,when they are not actively responding to overt pathological s...Microglia,the resident immune cells of the central nervous system,exhibit a wide array of functional states,even in their so-called“homeostatic”condition,when they are not actively responding to overt pathological stimuli.These functional states can be visualized using a combination of multi-omics techniques(e.g.,gene and protein expression,posttranslational modifications,mRNA profiling,and metabolomics),and,in the case of homeostatic microglia,are largely defined by the global(e.g.,genetic variations,organism’s age,sex,circadian rhythms,and gut microbiota)as well as local(specific area of the brain,immediate microglial surrounding,neuron-glia interactions and synaptic density/activity)signals(Paolicelli et al.,2022).While phenomics(i.e.,ultrastructural microglial morphology and motility)is also one of the key microglial state-defining parameters,it is known that cells with similar morphology can belong to different functional states.展开更多
It is well known that coarse-grained super-elastic NiTi shape memory alloys(SMAs)exhibit localized rather than homogeneous martensite transformation(MT),which,however,can be strongly influenced by either internal size...It is well known that coarse-grained super-elastic NiTi shape memory alloys(SMAs)exhibit localized rather than homogeneous martensite transformation(MT),which,however,can be strongly influenced by either internal size(grain size,GS)or the external size(geometric size).The coupled effect of GS and geometric size on the functional properties has not been clearly understood yet.In this work,the super-elasticity,one-way,and stress-assisted two-way shape memory effects of the polycrystalline NiTi SMAs with different aspect ratios(length/width for the gauge section)and different GSs are investigated based on the phase field method.The coupled effect of the aspect ratio and GS on the functional properties is adequately revealed.The simulated results indicate that when the aspect ratio is lower than about 4:1,the stress biaxiality and stress heterogeneity in the gauge section of the sample become more and more obvious with decreasing the aspect ratio,which can significantly influence the microstructure evolution in the process involving external stress.Therefore,the corresponding functional property is strongly dependent on the aspect ratio.With decreasing the GS and the aspect ratio(to be lower than 4:1),both the aspect ratio and GS can affect the MT or martensite reorientation in each grain and the interaction among grains.Thus,due to the strong internal constraint(i.e.,the constraint of grain boundary)and the external constraint(i.e.,the constraint of geometric boundary),the capabilities of the functional properties of NiTi SMAs are gradually weakened and highly dependent on these two factors.展开更多
Fe-Mo functionally graded materials(FGMs)with different composition-change rates from 100%304 stainless steel to 100%Mo along the composition gradient direction were prepared by electron beam-directed energy depositio...Fe-Mo functionally graded materials(FGMs)with different composition-change rates from 100%304 stainless steel to 100%Mo along the composition gradient direction were prepared by electron beam-directed energy deposition(EB-DED)technique,including three samples with composition mutation of 100%,composition change rate of 10%and 30%.Results show that the composition-change rate significantly affects the microstructure and mechanical properties of the samples.In the sample with abrupt change of composition,the sharp shift in composition between 304 stainless steel and Mo leads to a great difference in the microstructure and hardness near the interface between the two materials.With the increase in the number of gradient layers,the composition changes continuously along the direction of deposition height,and the microstructure morphology shows a smooth transition from 304 stainless steel to Mo,which is gradually transformed from columnar crystal to dendritic crystal.Elements Fe,Mo,and other major elements transform linearly along the gradient direction,with sufficient interlayer diffusion between the deposited layers,leading to good metallurgical bonding.The smaller the change in composition gradient,the greater the microhardness value along the deposition direction.When the composition gradient is 10%,the gradient layer exhibits higher hardness(940 HV)and excellent resistance to surface abrasion,and the overall compressive properties of the samples are better,with the compressive fracture stress in the top region reaching 750.05±14 MPa.展开更多
Edible mushroom proteins are the promising ones with the advantages of complete essential amino acid profile and multiple functional activities.To reinforce their applications in functional food development,this study...Edible mushroom proteins are the promising ones with the advantages of complete essential amino acid profile and multiple functional activities.To reinforce their applications in functional food development,this study comprehensively evaluated the physicochemical and functional properties of protein isolates from 5 mushroom species,i.e.,Pleurotus eryngii(PEP),Pleurotus ostreatus(POP),Lentinula edodes(LEP),Flammulina velutipes(FVP)and Hypsizygus marmoreus(HMP).Results showed that PEP,LEP,FVP,POP and HMP exhibited better protein solubility(PS),water holding capacity(WHC),emulsification activity index(EAI),and foaming capacity(FC)than those of soybean protein and pea protein isolates(PPI).PEP(51.95%)and POP(49.15%)had a higher amount ofβ-sheet structure.Principal component analysis and correlation analysis showed that the seven proteins could be divided into 3 clusters,and WHC,EAI and FC were significantly positively correlated with PS andβ-sheet.The least gelation concentration of PEP(16%)and FVP(16%)at p H 6.0 and 7.0 was similar to PPI,and PEP showed better hardness,springiness and rheological properties than other proteins gels.Overall,our study showed that 5 edible mushroom proteins possessed excellent functionalities(except for gelling capacity),which provided novel insights on unexploited sources of mushroom proteins used as protein-based foods in the food industry.展开更多
Exogenous neural stem cell transplantation has become one of the most promising treatment methods for chronic stroke.Recent studies have shown that most ischemia-reperfusion model rats recover spontaneously after inju...Exogenous neural stem cell transplantation has become one of the most promising treatment methods for chronic stroke.Recent studies have shown that most ischemia-reperfusion model rats recover spontaneously after injury,which limits the ability to observe long-term behavioral recovery.Here,we used a severe stroke rat model with 150 minutes of ischemia,which produced severe behavioral deficiencies that persisted at 12 weeks,to study the therapeutic effect of neural stem cells on neural restoration in chronic stroke.Our study showed that stroke model rats treated with human neural stem cells had long-term sustained recovery of motor function,reduced infarction volume,long-term human neural stem cell survival,and improved local inflammatory environment and angiogenesis.We also demonstrated that transplanted human neural stem cells differentiated into mature neurons in vivo,formed stable functional synaptic connections with host neurons,and exhibited the electrophysiological properties of functional mature neurons,indicating that they replaced the damaged host neurons.The findings showed that human fetal-derived neural stem cells had long-term effects for neurological recovery in a model of severe stroke,which suggests that human neural stem cells-based therapy may be effective for repairing damaged neural circuits in stroke patients.展开更多
The electronic property of pyrite supercell containing As,Se,Te,Co or Ni hetero atoms were calculated using density functional theory（DFT）,and the reactivities of pyrite with oxygen and xanthate were discussed by fr...The electronic property of pyrite supercell containing As,Se,Te,Co or Ni hetero atoms were calculated using density functional theory（DFT）,and the reactivities of pyrite with oxygen and xanthate were discussed by frontier orbital methods.The cell volume expands due to the presence of impurity.Co and Ni mainly affect the bands near Fermi levels,while As mainly affects the shallow and deep valence bands,and Se and Te mainly affect the deep valence bands.Electronic density analysis suggests that there exists a strong covalent interaction between hetero atom and its surrounding atoms.By frontier orbital calculation,it is suggested that As,Co and Ni have greater influence on the HOMO and LUMO of pyrite than Se and Te.In addition,pyrite containing As,Co or Ni is easier to oxidize by oxygen than pyrite containing Se or Te,and pyrite containing Co or Ni has greater interaction with collector.These are in agreement with the observed pyrite practice.展开更多
We study the geometries, stabilities, electronic and magnetic properties of （MgO）n （n=2-10） clusters doped with a single Mn atom using the density functional theory with the gener- alized gradient approximation. T...We study the geometries, stabilities, electronic and magnetic properties of （MgO）n （n=2-10） clusters doped with a single Mn atom using the density functional theory with the gener- alized gradient approximation. The optimized geometries show that the impurity Mn atom prefers to replace the Mg atom which has low coordination number in all the lowest-energy MnMgn-1On （n=2-10） structures. The stability analysis clearly represents that the average binding energies of the doped clusters are larger than those of the corresponding pure （MgO）n clusters. Maximum peaks of the second order energy differences are observed for MnMg~_1On clusters at n=6, 9, implying that these clusters exhibit higher stability than their neighboring clusters. In addition, all the Mn-doped Mg clusters exhibit high total magnetic moments with the exception of MnMgO2 which has 3.00μB. Their magnetic behavior is attributed to the impurity Mn atom, the charge transfer modes, and the size of MnMgn- 1On clusters.展开更多
[Objective] This study aimed to investigate the functions and properties of the preliminarily determined characteristics listed in DUS test guideline of Tagetes L., and explore the representativeness and comprehensive...[Objective] This study aimed to investigate the functions and properties of the preliminarily determined characteristics listed in DUS test guideline of Tagetes L., and explore the representativeness and comprehensiveness of this group of characteristics in DUS test. [Method] Based on the functions and properties of the characteristics, the described plant part （s）, observation stage, expression pattern and observation method of each characteristic were analyzed to illustrate the representativeness and comprehensiveness of the combination of this group of characteristics in above functions and properties. [Result] As for described plant part（s）, there are 5 characteristics describing plant as a whole, 3 characteristics describing stem, 6 characteristics describing leaf, 23 characteristics describing flower and 1 characteristic describing physiological feature. As for observation stage, there are 1 characteristic needing to be observed in the stage of seedling, 1 characteristic in the stage of beginning of flowering and other 36 characteristics in the stage of fully flowering. As for the expression pattern, there are 10 qualitative characteristics, 9 pseudo-qualitative characteristics and 19 quantitative characteristics. As for the observation method, there are 30 characteristics using VG as the observation method, and 8 characteristics using MS. [Conclusion] In view of the variation and morphological properties of marigold, this group of characteristics are representative and comprehensive, and ensure the accuracy and easiness of DUS test of Tagetes L., thereby achieving the reasonable combination of characteristics in described plant parts, observation stages, expression patterns and observation methods.展开更多
In this paper, we introduce new subclasses Sp,q,^mj,l λ[A,B;γ]and Hp,q,λ^m,j,l（α,β）of certain p-valent analytic functions defined by a generalized differential operator. Majorizationproperties for functions bel...In this paper, we introduce new subclasses Sp,q,^mj,l λ[A,B;γ]and Hp,q,λ^m,j,l（α,β）of certain p-valent analytic functions defined by a generalized differential operator. Majorizationproperties for functions belonging to the classes Sp,q,^mj,l λ[A,B;γ]and Hp,q,λ^m,j,l（α,β）are investigated. Also, we point out some new or known consequences of our main results.展开更多
In this study, the Alaska pollock protein isolate(APPI) was hydrolyzed by Neutrase for 20, 40, 80, 120, 160, 200, and 240 min. Hydrolysates with different molecular weights were produced and they were named as H1–H7....In this study, the Alaska pollock protein isolate(APPI) was hydrolyzed by Neutrase for 20, 40, 80, 120, 160, 200, and 240 min. Hydrolysates with different molecular weights were produced and they were named as H1–H7. Furthermore, the effects of hydrolysis on the average molecular weights, functional properties(solubility, oil-holding capacities, foaming activities, and emulsifying properties), and antioxidant activities(1, 1-diphenyl-2-picrylhydrazyl, superoxide, and hydroxyl free radical-scavenging activities) were determined. It was found that when the degree of hydrolysis(DH) increased, the average molecular weights of the hydrolysates decreased significantly. The functional properties of APPI were also significantly improved. The hydrolysates of APPI exhibited better solubility, emulsifying activities, and foaming activities. Hydrolysates with low molecular weights(<1 kDa) had better solubility, oil-holding capacities, and emulsifying activities, while hydrolysates with higher molecular weights(>1 kDa) had better foaming activities. In addition, the hydrolysates exhibited excellent antioxidant properties, while the inhibition values of 1, 1-diphenyl-2-picryl hydroxyl(DPPH), superoxide, and hydroxyl free radical-scavenging activities, were 85.22%, 53.56%, and 75.00% respectively, when the concentration of the hydrolysates was 5.0 mg mL^(-1). The lower the average molecular weight was, the higher was the antioxidant activity. These results indicated that hydrolysis with Neutrase is an effective method for improving the functional and antioxidant properties of APPI. The hydrolysates of APPI displayed great potentials to be used as natural antioxidants in protein-rich aqueous foods such as nutrient supplements and sports beverages.展开更多
Conventional intermetallics are strong but brit-tle.However,multi-principal element intermetallics,also termed as high-entropy intermetallics(HEIs)in the recent high-entropy alloy literature,are strong but malleable,s...Conventional intermetallics are strong but brit-tle.However,multi-principal element intermetallics,also termed as high-entropy intermetallics(HEIs)in the recent high-entropy alloy literature,are strong but malleable,some of which even show appreciable ductility and fracture toughness at room temperature.In this article,we provide a focused review on the recent researches on HEIs,from the fundamentals,such as the concept of HEIs,the formation rules to the structural and functional properties of HEIs.The results hitherto reported clearly show that the HEIs with distinct properties could be a promising material for future structural and functional applications.展开更多
Giant red sea cucumber (Parastichopus californicus) is an under-utilized species due to its high tendency to autolysis.The aim of this study was to evaluate the functional properties of collagen hydrolysates from this...Giant red sea cucumber (Parastichopus californicus) is an under-utilized species due to its high tendency to autolysis.The aim of this study was to evaluate the functional properties of collagen hydrolysates from this species.The degree of hydrolysis (DH),amino acid composition,SDS-PAGE,emulsion activity index (EAI),emulsion stability index (ESI),foam expansion (FE),and foam stability (FS) of hydrolysates were investigated.The effects of pH on the EAI,ESI FE and FS of hydrolysates were also inves-tigated.The results indicated that the β and α1 chains of the collagen were effectively hydrolyzed by trypsin at 50℃ with an En-zyme/Substrate (E/S) ration of 1:20 (w:w).The DH of collagen was up to 17.3% after 3 h hydrolysis with trypsin.The hydrolysates had a molecular weight distribution of 1.1 17 kDa,and were abundant in glycine (Gly),proline (Pro),glutamic acid (Glu),alanine (Ala) and hydroxyproline (Hyp) residues.The hydrolysates were fractionated into three fractions (< 3 kDa,3 10 kDa,and > 10 kDa),and the fraction of 3 10 kDa exhibited a higher EAI value than the fraction of > 10 kDa (P<0.05).The fraction of > 10 kDa had higher FE and FS values than other fractions (P<0.05).The pH had an important effect on the EAI,ESI,FE and FS.All the fractions showed undesirable emulsion and forming properties at pH 4.0.Under pH 7.0 and pH 10.0,the 3 10 kDa fraction showed higher EAI value and the fraction of > 10 kDa showed higher FE value,respectively.They are hoped to be utilized as functional ingredients in food and nutraceutical industries.展开更多
For functional difference equations with unbounded delay,we characterized the existence of totally stable and asymptotically almost periodic solution by using stability properties of a bounded solution in a certain li...For functional difference equations with unbounded delay,we characterized the existence of totally stable and asymptotically almost periodic solution by using stability properties of a bounded solution in a certain limiting equation.展开更多
The phase transition of gallium phosphide （GAP） from zinc-blende （ZB） to a rocksalt （RS） structure is investigated by the plane-wave pseudopotential density functional theory （DFT）. Lattice constant a0, elasti...The phase transition of gallium phosphide （GAP） from zinc-blende （ZB） to a rocksalt （RS） structure is investigated by the plane-wave pseudopotential density functional theory （DFT）. Lattice constant a0, elastic constants cij, bulk modulus B0 and the pressure derivative of bulk modulus B0 are calculated. The results are in good agreement with numerous experimental and theoretical data. From the usual condition of equal enthalpies, the phase transition from the ZB to the RS structure occurs at 21.9 GPa, which is close to the experimental value of 22.0 GPa. The elastic properties of GaP with the ZB structure in a pressure range from 0 GPa to 21.9 GPa and those of the RS structure in a pressure range of pressures from 21.9 GPa to 40 GPa are obtained. According to the quasi-harmonic Debye model, in which the phononic effects are considered, the normalized volume V/Vo, the Debye temperature 8, the heat capacity Cv and the thermal expansion coefficient a are also discussed in a pressure range from 0 CPa to 40 GPa and a temperature range from 0 K to 1500 K.展开更多
Functionally graded material(FGM)can tailor properties of components such as wear resistance,corrosion resistance,and functionality to enhance the overall performance.The selective laser melting(SLM)additive manufactu...Functionally graded material(FGM)can tailor properties of components such as wear resistance,corrosion resistance,and functionality to enhance the overall performance.The selective laser melting(SLM)additive manufacturing highlights the capability in manufacturing FGMs with a high geometrical complexity and manufacture flexibility.In this work,the 316L/CuSn10/18Ni300/CoCr four-type materials FGMs were fabricated using SLM.The microstructure and properties of the FGMs were investigated to reveal the effects of SLM processing parameters on the defects.A large number of microcracks were found at the 316L/CuSn10 interface,which initiated from the fusion boundary of 316L region and extended along the building direction.The elastic modulus and nano-hardness in the 18Ni300/CoCr fusion zone decreased significantly,less than those in the 18Ni300 region or the CoCr region.The iron and copper elements were well diffused in the 316L/CuSn10 fusion zone,while elements in the CuSn10/18Ni300 and the 18Ni300/CoCr fusion zones showed significantly gradient transitions.Compared with other regions,the width of the CuSn10/18Ni300 interface and the CuSn10 region expand significantly.The mechanisms of materials fusion and crack generation at the 316L/CuSn10 interface were discussed.In addition,FGM structures without macro-crack were built by only altering the deposition subsequence of 316L and CuSn10,which provides a guide for the additive manufacturing of FGM structures.展开更多
It has been reported that fresh edible rice has more bioactive compounds and its protein is easier to digest and has lower hypoallergenic than mature rice. In this paper, the changes in structure and functional proper...It has been reported that fresh edible rice has more bioactive compounds and its protein is easier to digest and has lower hypoallergenic than mature rice. In this paper, the changes in structure and functional properties of proteins at five different stages, including early milky stage(EMS), middle milky stage(MMS), late milky stage(LMS), waxy ripe stage(WS)and ripening stage(RS), during the seed development were investigated. It was found that with the seed developing, the molecular weight of fresh rice protein gradually become larger while the secondary structure changed from the highest content of disordered structure at MMS to the highest content of ordered structure at RS, which affect the surface hydrophobicity and then the functional properties of proteins, including foaming properties, emulsifying properties and oil holding capacity. Fresh rice protein at MMS has the strongest surface hydrophobicity while fresh edible rice protein at RS has the strongest oil holding capability. The results of our study can provide a theoretical basis for the application of fresh rice protein in the food industry and help to develop new fresh edible rice food.展开更多
A first-principles density functional approach is used to study the electronic and the elastic properties of Nb15X （X = Ti, Zr, Hf, V, Ta, Cr, Mo, and W） alloys. The elastic constants cn and c12, the shear modulus C...A first-principles density functional approach is used to study the electronic and the elastic properties of Nb15X （X = Ti, Zr, Hf, V, Ta, Cr, Mo, and W） alloys. The elastic constants cn and c12, the shear modulus CI, and the elastic modulus E（lOO） are found to exhibit similar tendencies, each as a function of valence electron number per atom （EPA）, while c44 seems unclear. Both cu and c12 of Nb15X alloys increase monotonically with the increase of EPA. The C/ and E000） also show similar tendencies. The elastic constants （except c44） increase slightly when alloying with neighbours of a higher d-transition series. Our results are supported by the bonding density distribution. When solute atoms change from Ti（Zr, Hf） to V（Ta） then to Cr（Mo, W）, the bonding electron density between the central solute atom and its first neighbouring Nb atoms is increased and becomes more anisotropic, which indicates the strong interaction and thus enhances the elastic properties of Nb-Cr（Mo, W） alloys. Under uniaxial {100） tensile loading, alloyed elements with less （more） valence electrons decrease （increase） the ideal tensile strength.展开更多
The objective of present work is to apply the friction stir processing （FSP） to fabricate functionally graded SiC particulate reinforced Al6061 composite and investigate the effect of SiC particle mass fraction dist...The objective of present work is to apply the friction stir processing （FSP） to fabricate functionally graded SiC particulate reinforced Al6061 composite and investigate the effect of SiC particle mass fraction distribution on the mechanical properties and wear behavior ofAl6061/SiC composite. Regarding the obtained results in this work, with increasing SiC mass fraction, elongation decreased, but hardness enhanced. However, the optimized functionally graded composite with the highest tensile strength and wear resistance was achieved for composite with 10 wt% surface SiC. Also, the results showed that wear resistance and tensile strength decreased for composite with 13 wt% surface SiC, due to reinforcement particle clustering depending on high SiC mass fraction.展开更多
Functionally graded Al/B_4C, Al/Si C, Al/Al_2O_3 and Al/TiB_2 composites with constant 12%(mass fraction) of reinforcement were fabricated by centrifugal casting and hollow cylindrical components were obtained. Micros...Functionally graded Al/B_4C, Al/Si C, Al/Al_2O_3 and Al/TiB_2 composites with constant 12%(mass fraction) of reinforcement were fabricated by centrifugal casting and hollow cylindrical components were obtained. Microstructural characteristics were investigated at outer surface of all composites and segregation of reinforcement particles was observed. Graded property of the composites with different reinforcements was investigated through hardness and tensile measurements. Results revealed that the outer peripheries of all composites exhibit higher hardness except in Al/B_4C composite and the outer zones of all composites show higher tensile strength. Abrasive wear test was conducted on the outer peripheries of all composites and Al/TiB_2 composite exhibits less wear rate.展开更多
Molten salt synthesis （MSS） method has advantages of the simplicity in the process equipment, versatile and large-scale synthesis, and friendly environment, which provides an excellent approach to synthesize high pu...Molten salt synthesis （MSS） method has advantages of the simplicity in the process equipment, versatile and large-scale synthesis, and friendly environment, which provides an excellent approach to synthesize high pure oxide powders with controllable compositions and morphologies. Among these oxides, perovskite oxides with a composition of ABO3 exhibit a broad spectrum of physical properties and functions （e.g. ferroelectric, piezoelectric, magnetic, photovoltaic and photocatalytic properties）. The downscaling of the spatial geometry of perovskite oxides into nanometers result in novel properties that are different from the bulk and film counterparts. Recent interest in nanoscience and nanotechnology has led to great efforts focusing on the synthesis of low-dimensional perovskite oxide nanostructures （PONs） to better understand their novel physical properties at nanoscale. Therefore, the low-dimensional PONs such as perovskite nanoparticles, nanowires, nanorods, nanotubes, nanofibers, nanobelts, and two dimensional oxide nanostructures, play an important role in developing the next generation of oxide electronics. In the past few years, much effort has been made on the synthesis of PONs by MSS method and their structural characterizations. The functional applications of PONs are also explored in the fields of storage memory, energy harvesting, and solar energy conversion. This review summarizes the recent progress in the synthesis of low-dimensional PONs by MSS method and its modified ways. Their structural char- acterization and physical properties are also scrutinized. The potential applications of low-dimensional PONs in different fields such as data memory and storage, energy harvesting, solar energy conversion, are highlighted. Perspectives concerning the future research trends and challenges of low-dimensional PONs are also outlined. ~ 2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.展开更多
基金supported by Deutsche Forschungsgemeinschaft,German Research Foundation grant GA 654/13-2 to OG.
文摘Microglia,the resident immune cells of the central nervous system,exhibit a wide array of functional states,even in their so-called“homeostatic”condition,when they are not actively responding to overt pathological stimuli.These functional states can be visualized using a combination of multi-omics techniques(e.g.,gene and protein expression,posttranslational modifications,mRNA profiling,and metabolomics),and,in the case of homeostatic microglia,are largely defined by the global(e.g.,genetic variations,organism’s age,sex,circadian rhythms,and gut microbiota)as well as local(specific area of the brain,immediate microglial surrounding,neuron-glia interactions and synaptic density/activity)signals(Paolicelli et al.,2022).While phenomics(i.e.,ultrastructural microglial morphology and motility)is also one of the key microglial state-defining parameters,it is known that cells with similar morphology can belong to different functional states.
基金supported by the National Natural Science Foundation of China (Grant Nos.12202294 and 12022208)the Project funded by China Postdoctoral Science Foundation (Grant No.2022M712243)the Fundamental Research Funds for the Central Universities (Grant No.2023SCU12098).
文摘It is well known that coarse-grained super-elastic NiTi shape memory alloys(SMAs)exhibit localized rather than homogeneous martensite transformation(MT),which,however,can be strongly influenced by either internal size(grain size,GS)or the external size(geometric size).The coupled effect of GS and geometric size on the functional properties has not been clearly understood yet.In this work,the super-elasticity,one-way,and stress-assisted two-way shape memory effects of the polycrystalline NiTi SMAs with different aspect ratios(length/width for the gauge section)and different GSs are investigated based on the phase field method.The coupled effect of the aspect ratio and GS on the functional properties is adequately revealed.The simulated results indicate that when the aspect ratio is lower than about 4:1,the stress biaxiality and stress heterogeneity in the gauge section of the sample become more and more obvious with decreasing the aspect ratio,which can significantly influence the microstructure evolution in the process involving external stress.Therefore,the corresponding functional property is strongly dependent on the aspect ratio.With decreasing the GS and the aspect ratio(to be lower than 4:1),both the aspect ratio and GS can affect the MT or martensite reorientation in each grain and the interaction among grains.Thus,due to the strong internal constraint(i.e.,the constraint of grain boundary)and the external constraint(i.e.,the constraint of geometric boundary),the capabilities of the functional properties of NiTi SMAs are gradually weakened and highly dependent on these two factors.
基金National Natural Science Foundation of China(51975286)。
文摘Fe-Mo functionally graded materials(FGMs)with different composition-change rates from 100%304 stainless steel to 100%Mo along the composition gradient direction were prepared by electron beam-directed energy deposition(EB-DED)technique,including three samples with composition mutation of 100%,composition change rate of 10%and 30%.Results show that the composition-change rate significantly affects the microstructure and mechanical properties of the samples.In the sample with abrupt change of composition,the sharp shift in composition between 304 stainless steel and Mo leads to a great difference in the microstructure and hardness near the interface between the two materials.With the increase in the number of gradient layers,the composition changes continuously along the direction of deposition height,and the microstructure morphology shows a smooth transition from 304 stainless steel to Mo,which is gradually transformed from columnar crystal to dendritic crystal.Elements Fe,Mo,and other major elements transform linearly along the gradient direction,with sufficient interlayer diffusion between the deposited layers,leading to good metallurgical bonding.The smaller the change in composition gradient,the greater the microhardness value along the deposition direction.When the composition gradient is 10%,the gradient layer exhibits higher hardness(940 HV)and excellent resistance to surface abrasion,and the overall compressive properties of the samples are better,with the compressive fracture stress in the top region reaching 750.05±14 MPa.
基金supported by the special fund of Jiangsu Province for the transformation of scientific and technological achievements(BA2021062)Jiangsu agricultural science and technology independent innovation fund(CX(22)2007)。
文摘Edible mushroom proteins are the promising ones with the advantages of complete essential amino acid profile and multiple functional activities.To reinforce their applications in functional food development,this study comprehensively evaluated the physicochemical and functional properties of protein isolates from 5 mushroom species,i.e.,Pleurotus eryngii(PEP),Pleurotus ostreatus(POP),Lentinula edodes(LEP),Flammulina velutipes(FVP)and Hypsizygus marmoreus(HMP).Results showed that PEP,LEP,FVP,POP and HMP exhibited better protein solubility(PS),water holding capacity(WHC),emulsification activity index(EAI),and foaming capacity(FC)than those of soybean protein and pea protein isolates(PPI).PEP(51.95%)and POP(49.15%)had a higher amount ofβ-sheet structure.Principal component analysis and correlation analysis showed that the seven proteins could be divided into 3 clusters,and WHC,EAI and FC were significantly positively correlated with PS andβ-sheet.The least gelation concentration of PEP(16%)and FVP(16%)at p H 6.0 and 7.0 was similar to PPI,and PEP showed better hardness,springiness and rheological properties than other proteins gels.Overall,our study showed that 5 edible mushroom proteins possessed excellent functionalities(except for gelling capacity),which provided novel insights on unexploited sources of mushroom proteins used as protein-based foods in the food industry.
文摘Exogenous neural stem cell transplantation has become one of the most promising treatment methods for chronic stroke.Recent studies have shown that most ischemia-reperfusion model rats recover spontaneously after injury,which limits the ability to observe long-term behavioral recovery.Here,we used a severe stroke rat model with 150 minutes of ischemia,which produced severe behavioral deficiencies that persisted at 12 weeks,to study the therapeutic effect of neural stem cells on neural restoration in chronic stroke.Our study showed that stroke model rats treated with human neural stem cells had long-term sustained recovery of motor function,reduced infarction volume,long-term human neural stem cell survival,and improved local inflammatory environment and angiogenesis.We also demonstrated that transplanted human neural stem cells differentiated into mature neurons in vivo,formed stable functional synaptic connections with host neurons,and exhibited the electrophysiological properties of functional mature neurons,indicating that they replaced the damaged host neurons.The findings showed that human fetal-derived neural stem cells had long-term effects for neurological recovery in a model of severe stroke,which suggests that human neural stem cells-based therapy may be effective for repairing damaged neural circuits in stroke patients.
基金Project (50864001) supported by the National Natural Science Foundation of China
文摘The electronic property of pyrite supercell containing As,Se,Te,Co or Ni hetero atoms were calculated using density functional theory（DFT）,and the reactivities of pyrite with oxygen and xanthate were discussed by frontier orbital methods.The cell volume expands due to the presence of impurity.Co and Ni mainly affect the bands near Fermi levels,while As mainly affects the shallow and deep valence bands,and Se and Te mainly affect the deep valence bands.Electronic density analysis suggests that there exists a strong covalent interaction between hetero atom and its surrounding atoms.By frontier orbital calculation,it is suggested that As,Co and Ni have greater influence on the HOMO and LUMO of pyrite than Se and Te.In addition,pyrite containing As,Co or Ni is easier to oxidize by oxygen than pyrite containing Se or Te,and pyrite containing Co or Ni has greater interaction with collector.These are in agreement with the observed pyrite practice.
文摘We study the geometries, stabilities, electronic and magnetic properties of （MgO）n （n=2-10） clusters doped with a single Mn atom using the density functional theory with the gener- alized gradient approximation. The optimized geometries show that the impurity Mn atom prefers to replace the Mg atom which has low coordination number in all the lowest-energy MnMgn-1On （n=2-10） structures. The stability analysis clearly represents that the average binding energies of the doped clusters are larger than those of the corresponding pure （MgO）n clusters. Maximum peaks of the second order energy differences are observed for MnMg~_1On clusters at n=6, 9, implying that these clusters exhibit higher stability than their neighboring clusters. In addition, all the Mn-doped Mg clusters exhibit high total magnetic moments with the exception of MnMgO2 which has 3.00μB. Their magnetic behavior is attributed to the impurity Mn atom, the charge transfer modes, and the size of MnMgn- 1On clusters.
基金Supported by Special R&D Fund for National Public Service Sectors(Agriculture)of China(200903008-14)National 948 Project of China(2009-Z11)~~
文摘[Objective] This study aimed to investigate the functions and properties of the preliminarily determined characteristics listed in DUS test guideline of Tagetes L., and explore the representativeness and comprehensiveness of this group of characteristics in DUS test. [Method] Based on the functions and properties of the characteristics, the described plant part （s）, observation stage, expression pattern and observation method of each characteristic were analyzed to illustrate the representativeness and comprehensiveness of the combination of this group of characteristics in above functions and properties. [Result] As for described plant part（s）, there are 5 characteristics describing plant as a whole, 3 characteristics describing stem, 6 characteristics describing leaf, 23 characteristics describing flower and 1 characteristic describing physiological feature. As for observation stage, there are 1 characteristic needing to be observed in the stage of seedling, 1 characteristic in the stage of beginning of flowering and other 36 characteristics in the stage of fully flowering. As for the expression pattern, there are 10 qualitative characteristics, 9 pseudo-qualitative characteristics and 19 quantitative characteristics. As for the observation method, there are 30 characteristics using VG as the observation method, and 8 characteristics using MS. [Conclusion] In view of the variation and morphological properties of marigold, this group of characteristics are representative and comprehensive, and ensure the accuracy and easiness of DUS test of Tagetes L., thereby achieving the reasonable combination of characteristics in described plant parts, observation stages, expression patterns and observation methods.
基金Supported by the National Natural Science Foundation of China(Grant No.11271045)the Funds of Doctoral Programme of China(Grant No.20100003110004)the Natural Science Foundation of Inner Mongolia Province(Grant No.2010MS0117)
文摘In this paper, we introduce new subclasses Sp,q,^mj,l λ[A,B;γ]and Hp,q,λ^m,j,l（α,β）of certain p-valent analytic functions defined by a generalized differential operator. Majorizationproperties for functions belonging to the classes Sp,q,^mj,l λ[A,B;γ]and Hp,q,λ^m,j,l（α,β）are investigated. Also, we point out some new or known consequences of our main results.
基金supported by grants from the China Postdoctoral Science Foundation to Dr.Chuyi Liu(No.2016M592251)
文摘In this study, the Alaska pollock protein isolate(APPI) was hydrolyzed by Neutrase for 20, 40, 80, 120, 160, 200, and 240 min. Hydrolysates with different molecular weights were produced and they were named as H1–H7. Furthermore, the effects of hydrolysis on the average molecular weights, functional properties(solubility, oil-holding capacities, foaming activities, and emulsifying properties), and antioxidant activities(1, 1-diphenyl-2-picrylhydrazyl, superoxide, and hydroxyl free radical-scavenging activities) were determined. It was found that when the degree of hydrolysis(DH) increased, the average molecular weights of the hydrolysates decreased significantly. The functional properties of APPI were also significantly improved. The hydrolysates of APPI exhibited better solubility, emulsifying activities, and foaming activities. Hydrolysates with low molecular weights(<1 kDa) had better solubility, oil-holding capacities, and emulsifying activities, while hydrolysates with higher molecular weights(>1 kDa) had better foaming activities. In addition, the hydrolysates exhibited excellent antioxidant properties, while the inhibition values of 1, 1-diphenyl-2-picryl hydroxyl(DPPH), superoxide, and hydroxyl free radical-scavenging activities, were 85.22%, 53.56%, and 75.00% respectively, when the concentration of the hydrolysates was 5.0 mg mL^(-1). The lower the average molecular weight was, the higher was the antioxidant activity. These results indicated that hydrolysis with Neutrase is an effective method for improving the functional and antioxidant properties of APPI. The hydrolysates of APPI displayed great potentials to be used as natural antioxidants in protein-rich aqueous foods such as nutrient supplements and sports beverages.
基金financially supported by the General Research Fund (GRF) from Research Grant Council,the Hong Kong Government (Nos.CityU11213118 and CityU11200719)the fund from City University of Hong Kong (No.7005438)
文摘Conventional intermetallics are strong but brit-tle.However,multi-principal element intermetallics,also termed as high-entropy intermetallics(HEIs)in the recent high-entropy alloy literature,are strong but malleable,some of which even show appreciable ductility and fracture toughness at room temperature.In this article,we provide a focused review on the recent researches on HEIs,from the fundamentals,such as the concept of HEIs,the formation rules to the structural and functional properties of HEIs.The results hitherto reported clearly show that the HEIs with distinct properties could be a promising material for future structural and functional applications.
基金supported by the National Key Technology Research and Development Program of China (Grant No.2006BAD30B01)the Research Award Fund for Excellent Young Scientist of Shandong Province,China (Grant No.BS2009HZ005)
文摘Giant red sea cucumber (Parastichopus californicus) is an under-utilized species due to its high tendency to autolysis.The aim of this study was to evaluate the functional properties of collagen hydrolysates from this species.The degree of hydrolysis (DH),amino acid composition,SDS-PAGE,emulsion activity index (EAI),emulsion stability index (ESI),foam expansion (FE),and foam stability (FS) of hydrolysates were investigated.The effects of pH on the EAI,ESI FE and FS of hydrolysates were also inves-tigated.The results indicated that the β and α1 chains of the collagen were effectively hydrolyzed by trypsin at 50℃ with an En-zyme/Substrate (E/S) ration of 1:20 (w:w).The DH of collagen was up to 17.3% after 3 h hydrolysis with trypsin.The hydrolysates had a molecular weight distribution of 1.1 17 kDa,and were abundant in glycine (Gly),proline (Pro),glutamic acid (Glu),alanine (Ala) and hydroxyproline (Hyp) residues.The hydrolysates were fractionated into three fractions (< 3 kDa,3 10 kDa,and > 10 kDa),and the fraction of 3 10 kDa exhibited a higher EAI value than the fraction of > 10 kDa (P<0.05).The fraction of > 10 kDa had higher FE and FS values than other fractions (P<0.05).The pH had an important effect on the EAI,ESI,FE and FS.All the fractions showed undesirable emulsion and forming properties at pH 4.0.Under pH 7.0 and pH 10.0,the 3 10 kDa fraction showed higher EAI value and the fraction of > 10 kDa showed higher FE value,respectively.They are hoped to be utilized as functional ingredients in food and nutraceutical industries.
文摘For functional difference equations with unbounded delay,we characterized the existence of totally stable and asymptotically almost periodic solution by using stability properties of a bounded solution in a certain limiting equation.
文摘The phase transition of gallium phosphide （GAP） from zinc-blende （ZB） to a rocksalt （RS） structure is investigated by the plane-wave pseudopotential density functional theory （DFT）. Lattice constant a0, elastic constants cij, bulk modulus B0 and the pressure derivative of bulk modulus B0 are calculated. The results are in good agreement with numerous experimental and theoretical data. From the usual condition of equal enthalpies, the phase transition from the ZB to the RS structure occurs at 21.9 GPa, which is close to the experimental value of 22.0 GPa. The elastic properties of GaP with the ZB structure in a pressure range from 0 GPa to 21.9 GPa and those of the RS structure in a pressure range of pressures from 21.9 GPa to 40 GPa are obtained. According to the quasi-harmonic Debye model, in which the phononic effects are considered, the normalized volume V/Vo, the Debye temperature 8, the heat capacity Cv and the thermal expansion coefficient a are also discussed in a pressure range from 0 CPa to 40 GPa and a temperature range from 0 K to 1500 K.
基金Project(2020B090922002)supported by Guangdong Provincial Key Field Research and Development Program,ChinaProjects(51875215,52005189)supported by the National Natural Science Foundation of ChinaProject(2019B1515120094)supported by Guangdong Provincial Basic and Applied Basic Research Fund,China。
文摘Functionally graded material(FGM)can tailor properties of components such as wear resistance,corrosion resistance,and functionality to enhance the overall performance.The selective laser melting(SLM)additive manufacturing highlights the capability in manufacturing FGMs with a high geometrical complexity and manufacture flexibility.In this work,the 316L/CuSn10/18Ni300/CoCr four-type materials FGMs were fabricated using SLM.The microstructure and properties of the FGMs were investigated to reveal the effects of SLM processing parameters on the defects.A large number of microcracks were found at the 316L/CuSn10 interface,which initiated from the fusion boundary of 316L region and extended along the building direction.The elastic modulus and nano-hardness in the 18Ni300/CoCr fusion zone decreased significantly,less than those in the 18Ni300 region or the CoCr region.The iron and copper elements were well diffused in the 316L/CuSn10 fusion zone,while elements in the CuSn10/18Ni300 and the 18Ni300/CoCr fusion zones showed significantly gradient transitions.Compared with other regions,the width of the CuSn10/18Ni300 interface and the CuSn10 region expand significantly.The mechanisms of materials fusion and crack generation at the 316L/CuSn10 interface were discussed.In addition,FGM structures without macro-crack were built by only altering the deposition subsequence of 316L and CuSn10,which provides a guide for the additive manufacturing of FGM structures.
基金the financial support from the Postdoctoral Research Project of Heilongjiang Provincial Department of Human Resources and Social Security (LBH-Q21156)Heilongjiang BaYi Agricultural University Support Program for San Zong San Heng (ZDZX202104)+3 种基金Science Foundation Project of Heilongjiang Province (QC2015028)National Natural Science Foundation of China (32072258)Major Science and technology Program of Heilongjiang (2019ZX08B02,2020ZX08B02)Central financial support for the development of local colleges and universities,Graduate research and innovation project of Harbin University of Commerce (YJSCX2020636HSD)。
文摘It has been reported that fresh edible rice has more bioactive compounds and its protein is easier to digest and has lower hypoallergenic than mature rice. In this paper, the changes in structure and functional properties of proteins at five different stages, including early milky stage(EMS), middle milky stage(MMS), late milky stage(LMS), waxy ripe stage(WS)and ripening stage(RS), during the seed development were investigated. It was found that with the seed developing, the molecular weight of fresh rice protein gradually become larger while the secondary structure changed from the highest content of disordered structure at MMS to the highest content of ordered structure at RS, which affect the surface hydrophobicity and then the functional properties of proteins, including foaming properties, emulsifying properties and oil holding capacity. Fresh rice protein at MMS has the strongest surface hydrophobicity while fresh edible rice protein at RS has the strongest oil holding capability. The results of our study can provide a theoretical basis for the application of fresh rice protein in the food industry and help to develop new fresh edible rice food.
基金Project supported by the National Natural Science Foundation of China(Grant No.50771004)
文摘A first-principles density functional approach is used to study the electronic and the elastic properties of Nb15X （X = Ti, Zr, Hf, V, Ta, Cr, Mo, and W） alloys. The elastic constants cn and c12, the shear modulus CI, and the elastic modulus E（lOO） are found to exhibit similar tendencies, each as a function of valence electron number per atom （EPA）, while c44 seems unclear. Both cu and c12 of Nb15X alloys increase monotonically with the increase of EPA. The C/ and E000） also show similar tendencies. The elastic constants （except c44） increase slightly when alloying with neighbours of a higher d-transition series. Our results are supported by the bonding density distribution. When solute atoms change from Ti（Zr, Hf） to V（Ta） then to Cr（Mo, W）, the bonding electron density between the central solute atom and its first neighbouring Nb atoms is increased and becomes more anisotropic, which indicates the strong interaction and thus enhances the elastic properties of Nb-Cr（Mo, W） alloys. Under uniaxial {100） tensile loading, alloyed elements with less （more） valence electrons decrease （increase） the ideal tensile strength.
文摘The objective of present work is to apply the friction stir processing （FSP） to fabricate functionally graded SiC particulate reinforced Al6061 composite and investigate the effect of SiC particle mass fraction distribution on the mechanical properties and wear behavior ofAl6061/SiC composite. Regarding the obtained results in this work, with increasing SiC mass fraction, elongation decreased, but hardness enhanced. However, the optimized functionally graded composite with the highest tensile strength and wear resistance was achieved for composite with 10 wt% surface SiC. Also, the results showed that wear resistance and tensile strength decreased for composite with 13 wt% surface SiC, due to reinforcement particle clustering depending on high SiC mass fraction.
基金Department of Science and Technology (India) for the financial support (Grant No.SR/S3/MERC/0116/2012)
文摘Functionally graded Al/B_4C, Al/Si C, Al/Al_2O_3 and Al/TiB_2 composites with constant 12%(mass fraction) of reinforcement were fabricated by centrifugal casting and hollow cylindrical components were obtained. Microstructural characteristics were investigated at outer surface of all composites and segregation of reinforcement particles was observed. Graded property of the composites with different reinforcements was investigated through hardness and tensile measurements. Results revealed that the outer peripheries of all composites exhibit higher hardness except in Al/B_4C composite and the outer zones of all composites show higher tensile strength. Abrasive wear test was conducted on the outer peripheries of all composites and Al/TiB_2 composite exhibits less wear rate.
基金the financial support from the National Natural Science Foundation of China(Grant Nos.11674161,11174122 and 11134004)the Six Big Talent Peak Project from Jiangsu Province(Grant No.XCL-004)open project of National Laboratory of Solid State Microstructures,Nanjing University(Grant No.M28026)
文摘Molten salt synthesis （MSS） method has advantages of the simplicity in the process equipment, versatile and large-scale synthesis, and friendly environment, which provides an excellent approach to synthesize high pure oxide powders with controllable compositions and morphologies. Among these oxides, perovskite oxides with a composition of ABO3 exhibit a broad spectrum of physical properties and functions （e.g. ferroelectric, piezoelectric, magnetic, photovoltaic and photocatalytic properties）. The downscaling of the spatial geometry of perovskite oxides into nanometers result in novel properties that are different from the bulk and film counterparts. Recent interest in nanoscience and nanotechnology has led to great efforts focusing on the synthesis of low-dimensional perovskite oxide nanostructures （PONs） to better understand their novel physical properties at nanoscale. Therefore, the low-dimensional PONs such as perovskite nanoparticles, nanowires, nanorods, nanotubes, nanofibers, nanobelts, and two dimensional oxide nanostructures, play an important role in developing the next generation of oxide electronics. In the past few years, much effort has been made on the synthesis of PONs by MSS method and their structural characterizations. The functional applications of PONs are also explored in the fields of storage memory, energy harvesting, and solar energy conversion. This review summarizes the recent progress in the synthesis of low-dimensional PONs by MSS method and its modified ways. Their structural char- acterization and physical properties are also scrutinized. The potential applications of low-dimensional PONs in different fields such as data memory and storage, energy harvesting, solar energy conversion, are highlighted. Perspectives concerning the future research trends and challenges of low-dimensional PONs are also outlined. ~ 2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.
