Some milk-associated proteins are known to be nutritionally valuable and form bioactive peptides that exhibit activity against hypertension and oxidative stress. Consumption of cheeses, such as the popular Hispanic-st...Some milk-associated proteins are known to be nutritionally valuable and form bioactive peptides that exhibit activity against hypertension and oxidative stress. Consumption of cheeses, such as the popular Hispanic-style cheese Queso Fresco (QF), may be a vehicle for delivery of these milk-associated peptides. This paper describes the effects of high-pressure processing (HPP) on the antioxidative activity (ORAC- FL value) of water-soluble proteins extracted from QF samples. QFs were manufactured according to a commercial-make procedure using pasteurized, homogenized milk, without added starter cultures. The cheese was cut into 45 × 45 × 150 mm3 blocks, double packaged in vacuum bags, and received the following HPP treatments: 200, 400, or 600 MPa for either 0, 5, 10, or 20 min, with warming to an internal temperature of either 22℃ or 40℃ prior to HPP treatment. Results show that the core temperature of the cheese during HPP directly affects the ORAC-FL value. The activities of the lower temperature cheeses are independent of time and pressure, and have a median ORAC-FL value of 27 trolox equivalents (TE). The higher temperature cheeses have higher ORAC-FL values ranging from 21.5 to 96.0 TE;the highest activity corresponded to the cheese held at 400 MPa for the longest time under pressure (20 min). The 600 MPa cheeses increase in activity with increasing time under pressure, but are less active than the control cheese. These results indicate that processing temperature and pressure are important factors in the antioxidative activity of these QF samples and further understanding of the roles of these variables may lead to the manufacture of healthier and more nutritious cheeses and dairy products.展开更多
The application of high pressure favors many chemical processes, providing higher yields or improved rates in chemical reactions and improved solvent power in separation processes, and allowing activation barriers to ...The application of high pressure favors many chemical processes, providing higher yields or improved rates in chemical reactions and improved solvent power in separation processes, and allowing activation barriers to be overcome through the increase in molecular energy and molecular collision rates. High pressures-up to millions of bars using diamond anvil cells-can be achieved in the laboratory, and lead to many new routes for chemical synthesis and the synthesis of new materials with desirable thermody- namic, transport, and electronic properties. On the industrial scale, however, high-pressure processing is currently limited by the cost of compression and by materials limitations, so that few industrial processes are carried out at pressures above 25 MPa. An alternative approach to high-pressure processing is pro- posed here, in which very high local pressures are generated using the surface-driven interactions from a solid substrate. Recent experiments and molecular simulations show that such interactions can lead to local pressures as high as tens of thousands of bars （1 bar=1×10^5 Pa）, and even millions of bars in some cases. Since the active high-pressure processing zone is inhomogeneous, the pressure is different in dif- ferent directions. In many cases, it is the pressure in the direction parallel to the surface of the substrate （the tangential pressure） that is most greatly enhanced. This pressure is exerted on the molecules to be processed, but not on the solid substrate or the containing vessel. Current knowledge of such pressure enhancement is reviewed, and the possibility of an alternative route to high-pressure processing based on surface-driven forces is discussed. Such surface-driven high-pressure processing would have the advantage of achieving much higher pressures than are possible with traditional bulk-phase processing, since it eliminates the need for mechanical compression. Moreover, no increased pressure is exerted on the containing vessel for the process, thus eliminating concerns about materials failure.展开更多
Background and objectives:High-pressure processing(HPP)is a promising assistive method to extract pectic polysaccharides with high rhamnogalacturonan I(RG-I)domain and berries are sources of such pectic polysaccharide...Background and objectives:High-pressure processing(HPP)is a promising assistive method to extract pectic polysaccharides with high rhamnogalacturonan I(RG-I)domain and berries are sources of such pectic polysaccharides.This study extracts pectic polysaccharides from goji berry,raspberry,and cranberry,examines how HPP influences the pectic polysaccharide structure of three berries,and provides a basis for the extraction and modification of pectic polysaccharides with specific structure and bioactivity.Materials and methods:An orthogonal test was performed to optimize the HPP-assisted alkali method to extract the high yield and high RG-I content pectic polysaccharides from three berries.Structural information of pectic polysaccharides extracted by the HPP method and conventional methods were compared from the perspectives of monosaccharide composition,molecular weight,Fourier transform infrared spectroscopy,andnuclearmagneticresonancespectroscopy.Results:For raspberry,the optimal conditions consisted of a pressure of 50o MPa,a pH of 13,and a pressure-holding time of 12 min,while the optimal conditions for goji berry and cranberry were both 40o MPa,pH 13,and 15 min.Under the optimal conditions,the yields for goji berry,raspberry,and cranberry were 10.49%,16.63%,and 17.52%,respectively,and RG-l contents were 81.85%,83.30%,and 63.22%,respectively.HPP showed an effect to degrade homogalacturonan backbones and side chains and increase the RG-I content to some extent.Conclusion:HPP-assisted alkali method was revealed to be an efficient method to extract high RG-I content pectic polysaccharides,especially for cranberry,and was a potential method to modify pectic polysaccharide structure in a certain way.展开更多
Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim ...Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of signifi cant,novel,and high-impact research in the fi elds of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.展开更多
Oxide dispersion strengthened(ODS)alloys are extensively used owing to high thermostability and creep strength contributed from uniformly dispersed fine oxides particles.However,the existence of these strengthening pa...Oxide dispersion strengthened(ODS)alloys are extensively used owing to high thermostability and creep strength contributed from uniformly dispersed fine oxides particles.However,the existence of these strengthening particles also deteriorates the processability and it is of great importance to establish accurate processing maps to guide the thermomechanical processes to enhance the formability.In this study,we performed particle swarm optimization-based back propagation artificial neural network model to predict the high temperature flow behavior of 0.25wt%Al2O3 particle-reinforced Cu alloys,and compared the accuracy with that of derived by Arrhenius-type constitutive model and back propagation artificial neural network model.To train these models,we obtained the raw data by fabricating ODS Cu alloys using the internal oxidation and reduction method,and conducting systematic hot compression tests between 400 and800℃with strain rates of 10^(-2)-10 S^(-1).At last,processing maps for ODS Cu alloys were proposed by combining processing parameters,mechanical behavior,microstructure characterization,and the modeling results achieved a coefficient of determination higher than>99%.展开更多
The objectives of this study are to research the relationship between pectin and the softening of peach by soaking in citric acid solutions for 24 h at 35 ℃, pressurizing for 30 rain at 500 MPa or heating for 10 min....The objectives of this study are to research the relationship between pectin and the softening of peach by soaking in citric acid solutions for 24 h at 35 ℃, pressurizing for 30 rain at 500 MPa or heating for 10 min. Also, comparing high-pressure-induced jam （HP-jam） and heat-induced jam （H-jam） were evaluated. It was found that firmness of the peach decreased greatly when soaked at pH 2.0 〉 heated 〉 soaked at pH 2.2 or 2.5 〉 pressurized, respectively. About 88% of the peach pectin was water-soluble-pectin and high-methoxyl pectin, while low-methoxyl pectin was slight. During pressurization, the pectin did not change. However, pectin degraded through hydrolysis during heating; consequently, the middle lamella separated. Also, eight kinds of peach jam （65% sugar, pH 2.0 or pH 2.2, and 50% or 60% sugar, pH 2.5） were compared. Both color and flavor of HP-jam were better than H-jam. As the pH values were lower, L-, a-, b-values of jam became higher, and the jam became pinker. Raw peach contained about 0.3%-0.4% pectin, therefore, an addition of 0.6% pectin was needed for both HP- and H-jams. However, there was no great difference in rheology or sensory evaluation between HP- and H-jams.展开更多
Recently published in Joule,Feng Liu and colleagues from Shanghai Jiaotong University reported a record-breaking 20.8%power conversion efficiency in organic solar cells(OSCs)with an interpenetrating fibril network act...Recently published in Joule,Feng Liu and colleagues from Shanghai Jiaotong University reported a record-breaking 20.8%power conversion efficiency in organic solar cells(OSCs)with an interpenetrating fibril network active layer morphology,featuring a bulk p-in structure and proper vertical segregation achieved through additive-assisted layer-by-layer deposition.This optimized hierarchical gradient fibrillar morphology and optical management synergistically facilitates exciton diffusion,reduces recombination losses,and enhances light capture capability.This approach not only offers a solution to achieving high-efficiency devices but also demonstrates the potential for commercial applications of OSCs.展开更多
The gating system and the overflow system were designed according to the casting structure during high pressure die casting(HPDC) process. The simulation was carried out by ProCAST software to visualize the injection ...The gating system and the overflow system were designed according to the casting structure during high pressure die casting(HPDC) process. The simulation was carried out by ProCAST software to visualize the injection chamber pre-crystallization and the flow of molten metal. The main work is to research four die casting process parameters, i.e. injection temperature, low-pressure velocity, high-and low-pressure velocity’s switching position, and high-pressure velocity. Experimental results show that the higher injection temperature and lowpressure velocity can mitigate the pre-crystallization of the injection chamber. However, when the low-pressure velocity exceeds 0.2 m·s-1, the air entrapment in the chamber occurs. Besides, when the high-pressure velocity is greater than 2.5 m·s-1, the overflow channel at the final filling position is covered by the liquid metal too early. Finally, the injection temperature of 650 °C, the low-pressure velocity of 0.2 m·s-1, the high-and low-pressure velocity’s switching position of 320 mm and the high-pressure velocity of 2 m·s-1 are obtained as the optimal parameters by the software simulation, which has been verified by actual production.展开更多
High-pressure torsion(HPT)processing under a pressure of 6.0 GPa was applied to Ti29.7Ni50.3Hf20(at.%)alloy.Two types of structure were observed after HPT with 3 revolutions:first one is the mixture of amorphous phase...High-pressure torsion(HPT)processing under a pressure of 6.0 GPa was applied to Ti29.7Ni50.3Hf20(at.%)alloy.Two types of structure were observed after HPT with 3 revolutions:first one is the mixture of amorphous phase and retained nanocrystalline;second is the alternating bands of amorphous phase and high defect density crystalline.As a result,post deformation annealing(PDA)at 500-700℃leads to the non-uniform distribution of martensite and parent phase grains.The grains of martensite are twice larger compared to that of parent phase.The nanocrystalline and ultrafine grains form after annealing at 500-600℃and 700℃,respectively.The twinning mechanism does not change with the reduction of martensitic grains up to^35 nm.The relationship between strength and grain size in Ti29.7Ni50.3Hf20 alloy obeys the classical Hall-Petch relationship with a coefficient of 10.80±0.39 GPa nm^1/2.展开更多
The evolution of microstructure and microhardness was studied in a commercial tungsten-25%rhenium(mass fraction)(W-25Re)alloy processed by the high pressure torsion(HPT)procedure under a pressure of7.7GPa up to10revol...The evolution of microstructure and microhardness was studied in a commercial tungsten-25%rhenium(mass fraction)(W-25Re)alloy processed by the high pressure torsion(HPT)procedure under a pressure of7.7GPa up to10revolutions at different temperatures.The results show that the samples processed by10revolutions at room temperature could have the smallest grain size at around0.209μm.High saturation hardness(HV^1200)could be achieved after the rapid strengthening stage for samples processed by10revolutions both at room temperature and at573K.Microstructural observation and analysis from Hall-Patch relationship could reveal that grain refinement and grain boundaries strengthening are the main factors of hardening mechanism in W-25Re alloy.It is also demonstrated that sintered W-25Re sample may have brittle phase separation phenomenon after HPT processing.展开更多
High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile industry.Mg can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress aro...High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile industry.Mg can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress arouses the deformation of large integrated die-castings.Herein,the development of non-heat treatment Al alloys is becoming the hot topic.In addition,HPDC contains externally solidified crystals(ESCs),which are detrimental to the mechanical properties of castings.To achieve high strength and toughness of non-heat treatment die-casting Al-Si alloy,we used AlSi9Mn alloy as matrix with the introduction of Zr,Ti,Nb,and Ce.Their influences on ESCs and mechanical properties were systematically investigated through three-dimensional reconstruction and thermodynamic simulation.Our results reveal that the addition of Ti increased ESCs'size and porosity,while the introduction of Nb refined ESCs and decreased porosity.Meanwhile,large-sized Al_3(Zr,Ti)phases formed and degraded the mechanical properties.Subsequent introduction of Ce resulted in the poisoning effect and reduced mechanical properties.展开更多
The deformation process in the material volume under high-pressure torsion(HPT)was studied.As a model object for the observation of deformation process,we used a composite comprising a bronze matrix and niobium filame...The deformation process in the material volume under high-pressure torsion(HPT)was studied.As a model object for the observation of deformation process,we used a composite comprising a bronze matrix and niobium filaments.The arrangements of the niobium filaments in the bronze matrix and their size have regular geometry.This allows us to monitor and measure the displacement of the niobium filaments in the sample volume,which results from HTP.The bronze/niobium composite samples were subjected to HPT at room temperature and 6 GPa,and the number of revolutions N=1/4,1/2,1,2,3 and 5.It was shown that HPT with revolution number of 1 leads to the 360° rotation of entire sample volume without sample slippage.Similar deformational behavior during HPT can be expected for high-ductility metallic materials.The increase in the number of revolutions more than 2 leads to twisting the niobium filaments in the sample volume and the formation of 'vortex' multilayer structure.The mechanisms for the formation of such structures were discussed.展开更多
Burial dissolution is a critical diagenetic process influencing ultra-deep carbonate reservoir development and preservation.Artificial carbonate samples with different internal structures were prepared,and high-temper...Burial dissolution is a critical diagenetic process influencing ultra-deep carbonate reservoir development and preservation.Artificial carbonate samples with different internal structures were prepared,and high-temperature and highpressure dissolution kinetic simulations were conducted.The results demonstrate that the intensity of burial dissolution is controlled by temperature and pressure,while tectonic-fluid activity influences the development pattern of burial dissolution,ultimately determining the direction of its differential modification.Extensive burial dissolution is likely to occur primarily at relatively shallow depths,significantly influencing reservoir formation,preservation,modification,and adjustment.The development of faults facilitates the maintenance of the intensity of burial dissolution.The maximum intensity of burial dissolution occurs at the tips and overlap zones of faults and intersections of multiple faults.The larger the scale of the faults,the more conducive it is to the development of burial dissolution.Burial dissolution fosters the formation of fault networks characterized by enhanced reservoir capacity and permeability.Burial dissolution controlled by episodic tectonic-fluid activity is a plausible explanation for forming the Tarim Basin's ultra-deep fault-controlled“stringbead-like”reservoirs.展开更多
Degradable metals,represented by magnesium and magnesium alloys,have attracted significant attention as fracture internal fixation and bone defect repairing materials due to their good biocompatibility,suitable elasti...Degradable metals,represented by magnesium and magnesium alloys,have attracted significant attention as fracture internal fixation and bone defect repairing materials due to their good biocompatibility,suitable elastic modulus and degradable properties.The Mg-3Zn-1Ca-0.5Sr(wt%)alloy is considered a competitor in the biomaterial field thanks to its unique composition of essential nutrients and excellent mechanical properties.However,the presence of coarse second-phase particles in the alloy accelerates its degradation rate and causes excessive gas formation during implantation,which restricts the alloy's potential for clinical device applications.In order to further optimize the properties of the alloy,extrusion combined with high-pressure torsion(HPT)was adopted for deformation processing.The results show that by optimizing the material processing means,the grain can be refined and broken,and the second-phase distribution can be improved,thus improving the microstructure,mechanical properties,and corrosion resistance of the alloy.After 15 cycles of HPT processing,the grains of the alloy are significantly refined to the nanometer scale,reaching approximately 98 nm.Additionally,the second-phase distribution is greatly improved,transforming the original streamlined structure into a more dispersed distribution.This change in microstructure leads to a significant strengthening effect on the alloy,with a noticeable increase in hardness from 60.3 HV in the as-extruded state to 98.5 HV.展开更多
To improve the comprehensive mechanical properties of Al-Si-Cu alloy,it was treated by a high-pressure torsion process,and the effect of the deformation degree on the microstructure and properties of the Al-Si-Cu allo...To improve the comprehensive mechanical properties of Al-Si-Cu alloy,it was treated by a high-pressure torsion process,and the effect of the deformation degree on the microstructure and properties of the Al-Si-Cu alloy was studied.The results show that the reinforcements(β-Si andθ-CuAl_(2)phases)of the Al-Si-Cu alloy are dispersed in theα-Al matrix phase with finer phase size after the treatment.The processed samples exhibit grain sizes in the submicron or even nanometer range,which effectively improves the mechanical properties of the material.The hardness and strength of the deformed alloy are both significantly raised to 268 HV and 390.04 MPa by 10 turns HPT process,and the fracture morphology shows that the material gradually transits from brittle to plastic before and after deformation.The elements interdiffusion at the interface between the phases has also been effectively enhanced.In addition,it is found that the severe plastic deformation at room temperature induces a ternary eutectic reaction,resulting in the formation of ternary Al+Si+CuAl_(2)eutectic.展开更多
To thoroughly study the extinguishing effect of a high-pressure water mist fire extinguishing system when a transformer fire occurs,a 3D experimental model of a transformer is established in this work by employing Fir...To thoroughly study the extinguishing effect of a high-pressure water mist fire extinguishing system when a transformer fire occurs,a 3D experimental model of a transformer is established in this work by employing Fire Dynamics Simulator(FDS)software.More specifically,by setting different parameters,the process of the highpressure water mist fire extinguishing system with the presence of both diverse ambient temperatures and water mist sprinkler laying conditions is simulated.In addition,the fire extinguishing effect of the employed high-pressure water mist system with the implementation of different strategies is systematically analyzed.The extracted results show that a fire source farther away fromthe centerline leads to a lower local temperature distribution.In addition,as the ambient temperature increases,the temperature above the fire source decreases,while the temperature and the concentrationof theupperflue gas layer bothdecrease.Interestingly,after thehigh-pressurewatermist sprinkler begins to operate,both the temperature distribution above the fire source and the concentration of the flue gas decrease,which indicates that the high-pressure water mist system plays the role of cooling and dust removal.By comparing various sprinkler laying methods,it is found that the lower sprinkler height has a better effect on the temperature above the fire source,the temperature of the upper flue gas layer,and the concentration of the flue gas.Moreover,when the sprinkler is spread over thewhole transformer,the cooling effect on both the temperature above the fire source and the temperature of the upper flue gas layer is good,whereas the change in the concentration of the flue gas above the fire source is not obvious compared to the case where the sprinkler is not fully spread.展开更多
In general,the rapid growth of α-Fe clusters is a challenge in high Fe-content Fe-based amorphous alloys,negatively affecting their physical properties.Herein,we introduce an efficient and rapid post-treatment techni...In general,the rapid growth of α-Fe clusters is a challenge in high Fe-content Fe-based amorphous alloys,negatively affecting their physical properties.Herein,we introduce an efficient and rapid post-treatment technique known as ultrasonic vibration rapid processing(UVRP),which enables the formation of high-density strong magnetic α-Fe clusters,thereby enhancing the soft magnetic properties of Fe_(78)Si(13)B_(9) amorphous alloy ribbon.展开更多
Thin walls of an AZ91 magnesium alloy with fine equiaxed grains were fabricated via cold arc-based wire arc additive manufacturing(CA-WAAM),and the droplet transfer behaviours,microstructures,and mechanical properties...Thin walls of an AZ91 magnesium alloy with fine equiaxed grains were fabricated via cold arc-based wire arc additive manufacturing(CA-WAAM),and the droplet transfer behaviours,microstructures,and mechanical properties were investigated.The results showed that the cold arc process reduced splashing at the moment of liquid bridge breakage and effectively shortened the droplet transfer period.The microstructures of the deposited samples exhibited layered characteristics with alternating distributions of coarse and fine grains.During layer-by-layer deposition,the β-phase precipitated and grew preferentially along grain boundaries,while the fineη-Al_(8)Mn_(5)phase was dispersed in the α-Mg matrix.The mechanical properties of the CA-WAAM deposited sample showed isotropic characteristics.The ultimate tensile strength and elongation in the building direction(BD)were 282.7 MPa and 14.2%,respectively.The microhardness values of the deposited parts were relatively uniform,with an average value of HV 69.6.展开更多
Agricultural Products Processing and Storage (ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature) is an international,pect-review ed open access journal with the a...Agricultural Products Processing and Storage (ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature) is an international,pect-review ed open access journal with the aim to offer a platform for the rapid dissemination of significant,novel,and high-impact research in the fields of agricultural product processing science,technology,engineering,and nutrition.Additio nally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.展开更多
Ti-10V-2Fe-3Al alloy with fine-grainedβphases was fabricated by friction stir processing with opti-mized processing parameters.The superplastic behavior of the specimens was investigated by tensile deformation at dif...Ti-10V-2Fe-3Al alloy with fine-grainedβphases was fabricated by friction stir processing with opti-mized processing parameters.The superplastic behavior of the specimens was investigated by tensile deformation at different strain rates and temperatures,and an optimal superplastic elongation of 634%was achieved at 700℃ and 3×10^(-4)/s.An annealing treatment at 650℃ for 60 min showed a mi-crostructure withαprecipitates distributed in theβmatrix in the friction stir specimen.Such pre-heat treatment improves the superplasticity of the specimen,achieving an elongation of up to 807%at 750℃ and 3×10^(-4)/s.The influences of tensile temperatures and strain rates on the microstructural evolution,such as grain size variation,grain morphology,and phase transformations,were discussed.The super-plastic deformation behavior of fine-grained Ti-10V-2Fe-3Al alloy is controlled by grain boundary sliding and accompanied by dynamic phase transformation and recrystallization.展开更多
文摘Some milk-associated proteins are known to be nutritionally valuable and form bioactive peptides that exhibit activity against hypertension and oxidative stress. Consumption of cheeses, such as the popular Hispanic-style cheese Queso Fresco (QF), may be a vehicle for delivery of these milk-associated peptides. This paper describes the effects of high-pressure processing (HPP) on the antioxidative activity (ORAC- FL value) of water-soluble proteins extracted from QF samples. QFs were manufactured according to a commercial-make procedure using pasteurized, homogenized milk, without added starter cultures. The cheese was cut into 45 × 45 × 150 mm3 blocks, double packaged in vacuum bags, and received the following HPP treatments: 200, 400, or 600 MPa for either 0, 5, 10, or 20 min, with warming to an internal temperature of either 22℃ or 40℃ prior to HPP treatment. Results show that the core temperature of the cheese during HPP directly affects the ORAC-FL value. The activities of the lower temperature cheeses are independent of time and pressure, and have a median ORAC-FL value of 27 trolox equivalents (TE). The higher temperature cheeses have higher ORAC-FL values ranging from 21.5 to 96.0 TE;the highest activity corresponded to the cheese held at 400 MPa for the longest time under pressure (20 min). The 600 MPa cheeses increase in activity with increasing time under pressure, but are less active than the control cheese. These results indicate that processing temperature and pressure are important factors in the antioxidative activity of these QF samples and further understanding of the roles of these variables may lead to the manufacture of healthier and more nutritious cheeses and dairy products.
基金the US National Science Foundation (CBET-1603851 and CHE-1710102) for support of this workthe National Science Center of Poland (DEC-2013/09/B/ST4/03711) for support
文摘The application of high pressure favors many chemical processes, providing higher yields or improved rates in chemical reactions and improved solvent power in separation processes, and allowing activation barriers to be overcome through the increase in molecular energy and molecular collision rates. High pressures-up to millions of bars using diamond anvil cells-can be achieved in the laboratory, and lead to many new routes for chemical synthesis and the synthesis of new materials with desirable thermody- namic, transport, and electronic properties. On the industrial scale, however, high-pressure processing is currently limited by the cost of compression and by materials limitations, so that few industrial processes are carried out at pressures above 25 MPa. An alternative approach to high-pressure processing is pro- posed here, in which very high local pressures are generated using the surface-driven interactions from a solid substrate. Recent experiments and molecular simulations show that such interactions can lead to local pressures as high as tens of thousands of bars （1 bar=1×10^5 Pa）, and even millions of bars in some cases. Since the active high-pressure processing zone is inhomogeneous, the pressure is different in dif- ferent directions. In many cases, it is the pressure in the direction parallel to the surface of the substrate （the tangential pressure） that is most greatly enhanced. This pressure is exerted on the molecules to be processed, but not on the solid substrate or the containing vessel. Current knowledge of such pressure enhancement is reviewed, and the possibility of an alternative route to high-pressure processing based on surface-driven forces is discussed. Such surface-driven high-pressure processing would have the advantage of achieving much higher pressures than are possible with traditional bulk-phase processing, since it eliminates the need for mechanical compression. Moreover, no increased pressure is exerted on the containing vessel for the process, thus eliminating concerns about materials failure.
基金the Project of National Natural Science Foundation of China(32202071)Zhejiang Basic Public Welfare Research Project(LQ22C200003)+1 种基金Zhejiang Province Key R&D Project(2021C02001)the Key Research and Development Program of Ningxia Province(2022BBF02006),China.
文摘Background and objectives:High-pressure processing(HPP)is a promising assistive method to extract pectic polysaccharides with high rhamnogalacturonan I(RG-I)domain and berries are sources of such pectic polysaccharides.This study extracts pectic polysaccharides from goji berry,raspberry,and cranberry,examines how HPP influences the pectic polysaccharide structure of three berries,and provides a basis for the extraction and modification of pectic polysaccharides with specific structure and bioactivity.Materials and methods:An orthogonal test was performed to optimize the HPP-assisted alkali method to extract the high yield and high RG-I content pectic polysaccharides from three berries.Structural information of pectic polysaccharides extracted by the HPP method and conventional methods were compared from the perspectives of monosaccharide composition,molecular weight,Fourier transform infrared spectroscopy,andnuclearmagneticresonancespectroscopy.Results:For raspberry,the optimal conditions consisted of a pressure of 50o MPa,a pH of 13,and a pressure-holding time of 12 min,while the optimal conditions for goji berry and cranberry were both 40o MPa,pH 13,and 15 min.Under the optimal conditions,the yields for goji berry,raspberry,and cranberry were 10.49%,16.63%,and 17.52%,respectively,and RG-l contents were 81.85%,83.30%,and 63.22%,respectively.HPP showed an effect to degrade homogalacturonan backbones and side chains and increase the RG-I content to some extent.Conclusion:HPP-assisted alkali method was revealed to be an efficient method to extract high RG-I content pectic polysaccharides,especially for cranberry,and was a potential method to modify pectic polysaccharide structure in a certain way.
文摘Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of signifi cant,novel,and high-impact research in the fi elds of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.
基金financial support of the National Natural Science Foundation of China(No.52371103)the Fundamental Research Funds for the Central Universities,China(No.2242023K40028)+1 种基金the Open Research Fund of Jiangsu Key Laboratory for Advanced Metallic Materials,China(No.AMM2023B01).financial support of the Research Fund of Shihezi Key Laboratory of AluminumBased Advanced Materials,China(No.2023PT02)financial support of Guangdong Province Science and Technology Major Project,China(No.2021B0301030005)。
文摘Oxide dispersion strengthened(ODS)alloys are extensively used owing to high thermostability and creep strength contributed from uniformly dispersed fine oxides particles.However,the existence of these strengthening particles also deteriorates the processability and it is of great importance to establish accurate processing maps to guide the thermomechanical processes to enhance the formability.In this study,we performed particle swarm optimization-based back propagation artificial neural network model to predict the high temperature flow behavior of 0.25wt%Al2O3 particle-reinforced Cu alloys,and compared the accuracy with that of derived by Arrhenius-type constitutive model and back propagation artificial neural network model.To train these models,we obtained the raw data by fabricating ODS Cu alloys using the internal oxidation and reduction method,and conducting systematic hot compression tests between 400 and800℃with strain rates of 10^(-2)-10 S^(-1).At last,processing maps for ODS Cu alloys were proposed by combining processing parameters,mechanical behavior,microstructure characterization,and the modeling results achieved a coefficient of determination higher than>99%.
文摘The objectives of this study are to research the relationship between pectin and the softening of peach by soaking in citric acid solutions for 24 h at 35 ℃, pressurizing for 30 rain at 500 MPa or heating for 10 min. Also, comparing high-pressure-induced jam （HP-jam） and heat-induced jam （H-jam） were evaluated. It was found that firmness of the peach decreased greatly when soaked at pH 2.0 〉 heated 〉 soaked at pH 2.2 or 2.5 〉 pressurized, respectively. About 88% of the peach pectin was water-soluble-pectin and high-methoxyl pectin, while low-methoxyl pectin was slight. During pressurization, the pectin did not change. However, pectin degraded through hydrolysis during heating; consequently, the middle lamella separated. Also, eight kinds of peach jam （65% sugar, pH 2.0 or pH 2.2, and 50% or 60% sugar, pH 2.5） were compared. Both color and flavor of HP-jam were better than H-jam. As the pH values were lower, L-, a-, b-values of jam became higher, and the jam became pinker. Raw peach contained about 0.3%-0.4% pectin, therefore, an addition of 0.6% pectin was needed for both HP- and H-jams. However, there was no great difference in rheology or sensory evaluation between HP- and H-jams.
基金Technology Development Program of Jilin Province(YDZJ202201ZYTS640)the National Key Research and Development Program of China(2022YFB4200400)funded by MOST+4 种基金the National Natural Science Foundation of China(52172048 and 52103221)Shandong Provincial Natural Science Foundation(ZR2021QB024 and ZR2021ZD06)Guangdong Basic and Applied Basic Research Foundation(2023A1515012323,2023A1515010943,and 2024A1515010023)the Qingdao New Energy Shandong Laboratory open Project(QNESL OP 202309)the Fundamental Research Funds of Shandong University.
文摘Recently published in Joule,Feng Liu and colleagues from Shanghai Jiaotong University reported a record-breaking 20.8%power conversion efficiency in organic solar cells(OSCs)with an interpenetrating fibril network active layer morphology,featuring a bulk p-in structure and proper vertical segregation achieved through additive-assisted layer-by-layer deposition.This optimized hierarchical gradient fibrillar morphology and optical management synergistically facilitates exciton diffusion,reduces recombination losses,and enhances light capture capability.This approach not only offers a solution to achieving high-efficiency devices but also demonstrates the potential for commercial applications of OSCs.
基金financially supported by the National Key Research and Development Program of China(No.2016YFB0301003)
文摘The gating system and the overflow system were designed according to the casting structure during high pressure die casting(HPDC) process. The simulation was carried out by ProCAST software to visualize the injection chamber pre-crystallization and the flow of molten metal. The main work is to research four die casting process parameters, i.e. injection temperature, low-pressure velocity, high-and low-pressure velocity’s switching position, and high-pressure velocity. Experimental results show that the higher injection temperature and lowpressure velocity can mitigate the pre-crystallization of the injection chamber. However, when the low-pressure velocity exceeds 0.2 m·s-1, the air entrapment in the chamber occurs. Besides, when the high-pressure velocity is greater than 2.5 m·s-1, the overflow channel at the final filling position is covered by the liquid metal too early. Finally, the injection temperature of 650 °C, the low-pressure velocity of 0.2 m·s-1, the high-and low-pressure velocity’s switching position of 320 mm and the high-pressure velocity of 2 m·s-1 are obtained as the optimal parameters by the software simulation, which has been verified by actual production.
基金supported by National Key R&D Program of China[grant number 2017YFE0123500]National Natural Science Foundation of China[grant number 51971072,51671064]+2 种基金the Fundamental Research Funds for the Central University[grant number HEUCFG201836]the support from the RFBR-CNPq-DST research project№19-58-80018the support in part from the Russian Foundation for Basic Research(project No.20-03-00614)。
文摘High-pressure torsion(HPT)processing under a pressure of 6.0 GPa was applied to Ti29.7Ni50.3Hf20(at.%)alloy.Two types of structure were observed after HPT with 3 revolutions:first one is the mixture of amorphous phase and retained nanocrystalline;second is the alternating bands of amorphous phase and high defect density crystalline.As a result,post deformation annealing(PDA)at 500-700℃leads to the non-uniform distribution of martensite and parent phase grains.The grains of martensite are twice larger compared to that of parent phase.The nanocrystalline and ultrafine grains form after annealing at 500-600℃and 700℃,respectively.The twinning mechanism does not change with the reduction of martensitic grains up to^35 nm.The relationship between strength and grain size in Ti29.7Ni50.3Hf20 alloy obeys the classical Hall-Petch relationship with a coefficient of 10.80±0.39 GPa nm^1/2.
基金Project(11402264)supported by the National Natural Science Foundation of ChinaProject(BK20160182)supported by the Natural Science Foundation of Jiangsu Province,ChinaProjects(JUSRP116027,JUSRP51732B)supported by the Fundamental Research Funds from Jiangnan University,China
文摘The evolution of microstructure and microhardness was studied in a commercial tungsten-25%rhenium(mass fraction)(W-25Re)alloy processed by the high pressure torsion(HPT)procedure under a pressure of7.7GPa up to10revolutions at different temperatures.The results show that the samples processed by10revolutions at room temperature could have the smallest grain size at around0.209μm.High saturation hardness(HV^1200)could be achieved after the rapid strengthening stage for samples processed by10revolutions both at room temperature and at573K.Microstructural observation and analysis from Hall-Patch relationship could reveal that grain refinement and grain boundaries strengthening are the main factors of hardening mechanism in W-25Re alloy.It is also demonstrated that sintered W-25Re sample may have brittle phase separation phenomenon after HPT processing.
基金financially supported by the National Natural Science Foundation of China(Nos.52175284 and 52474396)the National Key Research and Development Program of China(No.2022YFB3404201)。
文摘High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile industry.Mg can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress arouses the deformation of large integrated die-castings.Herein,the development of non-heat treatment Al alloys is becoming the hot topic.In addition,HPDC contains externally solidified crystals(ESCs),which are detrimental to the mechanical properties of castings.To achieve high strength and toughness of non-heat treatment die-casting Al-Si alloy,we used AlSi9Mn alloy as matrix with the introduction of Zr,Ti,Nb,and Ce.Their influences on ESCs and mechanical properties were systematically investigated through three-dimensional reconstruction and thermodynamic simulation.Our results reveal that the addition of Ti increased ESCs'size and porosity,while the introduction of Nb refined ESCs and decreased porosity.Meanwhile,large-sized Al_3(Zr,Ti)phases formed and degraded the mechanical properties.Subsequent introduction of Ce resulted in the poisoning effect and reduced mechanical properties.
基金financial support from the Ministry of Science and Higher Education of the Russian Federation in the framework of Increase Competitiveness Program of NUST “MISi S” (No. K2-2019-008)
文摘The deformation process in the material volume under high-pressure torsion(HPT)was studied.As a model object for the observation of deformation process,we used a composite comprising a bronze matrix and niobium filaments.The arrangements of the niobium filaments in the bronze matrix and their size have regular geometry.This allows us to monitor and measure the displacement of the niobium filaments in the sample volume,which results from HTP.The bronze/niobium composite samples were subjected to HPT at room temperature and 6 GPa,and the number of revolutions N=1/4,1/2,1,2,3 and 5.It was shown that HPT with revolution number of 1 leads to the 360° rotation of entire sample volume without sample slippage.Similar deformational behavior during HPT can be expected for high-ductility metallic materials.The increase in the number of revolutions more than 2 leads to twisting the niobium filaments in the sample volume and the formation of 'vortex' multilayer structure.The mechanisms for the formation of such structures were discussed.
基金supported by the National Natural Science Foundation of China(Grant No.U21B2062)supported by the Key Laboratory for Carbonate Reservoirs of China National Petroleum Corporation。
文摘Burial dissolution is a critical diagenetic process influencing ultra-deep carbonate reservoir development and preservation.Artificial carbonate samples with different internal structures were prepared,and high-temperature and highpressure dissolution kinetic simulations were conducted.The results demonstrate that the intensity of burial dissolution is controlled by temperature and pressure,while tectonic-fluid activity influences the development pattern of burial dissolution,ultimately determining the direction of its differential modification.Extensive burial dissolution is likely to occur primarily at relatively shallow depths,significantly influencing reservoir formation,preservation,modification,and adjustment.The development of faults facilitates the maintenance of the intensity of burial dissolution.The maximum intensity of burial dissolution occurs at the tips and overlap zones of faults and intersections of multiple faults.The larger the scale of the faults,the more conducive it is to the development of burial dissolution.Burial dissolution fosters the formation of fault networks characterized by enhanced reservoir capacity and permeability.Burial dissolution controlled by episodic tectonic-fluid activity is a plausible explanation for forming the Tarim Basin's ultra-deep fault-controlled“stringbead-like”reservoirs.
基金National Key Research and Development Program of China(2021YFB3701004)。
文摘Degradable metals,represented by magnesium and magnesium alloys,have attracted significant attention as fracture internal fixation and bone defect repairing materials due to their good biocompatibility,suitable elastic modulus and degradable properties.The Mg-3Zn-1Ca-0.5Sr(wt%)alloy is considered a competitor in the biomaterial field thanks to its unique composition of essential nutrients and excellent mechanical properties.However,the presence of coarse second-phase particles in the alloy accelerates its degradation rate and causes excessive gas formation during implantation,which restricts the alloy's potential for clinical device applications.In order to further optimize the properties of the alloy,extrusion combined with high-pressure torsion(HPT)was adopted for deformation processing.The results show that by optimizing the material processing means,the grain can be refined and broken,and the second-phase distribution can be improved,thus improving the microstructure,mechanical properties,and corrosion resistance of the alloy.After 15 cycles of HPT processing,the grains of the alloy are significantly refined to the nanometer scale,reaching approximately 98 nm.Additionally,the second-phase distribution is greatly improved,transforming the original streamlined structure into a more dispersed distribution.This change in microstructure leads to a significant strengthening effect on the alloy,with a noticeable increase in hardness from 60.3 HV in the as-extruded state to 98.5 HV.
基金Funded by the National Natural Science Foundation of China(No.51905215)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCX23_1233)+1 种基金Major Scientific and Technological Innovation Project of Shandong Province of China(No.2019JZZY020111)the National College Students Innovation and Entrepreneurship Training Program of China(No.CX2022415)。
文摘To improve the comprehensive mechanical properties of Al-Si-Cu alloy,it was treated by a high-pressure torsion process,and the effect of the deformation degree on the microstructure and properties of the Al-Si-Cu alloy was studied.The results show that the reinforcements(β-Si andθ-CuAl_(2)phases)of the Al-Si-Cu alloy are dispersed in theα-Al matrix phase with finer phase size after the treatment.The processed samples exhibit grain sizes in the submicron or even nanometer range,which effectively improves the mechanical properties of the material.The hardness and strength of the deformed alloy are both significantly raised to 268 HV and 390.04 MPa by 10 turns HPT process,and the fracture morphology shows that the material gradually transits from brittle to plastic before and after deformation.The elements interdiffusion at the interface between the phases has also been effectively enhanced.In addition,it is found that the severe plastic deformation at room temperature induces a ternary eutectic reaction,resulting in the formation of ternary Al+Si+CuAl_(2)eutectic.
基金supported by Science and Technology Projects Funded by State Grid Corporation of China (5200202024105A0000).
文摘To thoroughly study the extinguishing effect of a high-pressure water mist fire extinguishing system when a transformer fire occurs,a 3D experimental model of a transformer is established in this work by employing Fire Dynamics Simulator(FDS)software.More specifically,by setting different parameters,the process of the highpressure water mist fire extinguishing system with the presence of both diverse ambient temperatures and water mist sprinkler laying conditions is simulated.In addition,the fire extinguishing effect of the employed high-pressure water mist system with the implementation of different strategies is systematically analyzed.The extracted results show that a fire source farther away fromthe centerline leads to a lower local temperature distribution.In addition,as the ambient temperature increases,the temperature above the fire source decreases,while the temperature and the concentrationof theupperflue gas layer bothdecrease.Interestingly,after thehigh-pressurewatermist sprinkler begins to operate,both the temperature distribution above the fire source and the concentration of the flue gas decrease,which indicates that the high-pressure water mist system plays the role of cooling and dust removal.By comparing various sprinkler laying methods,it is found that the lower sprinkler height has a better effect on the temperature above the fire source,the temperature of the upper flue gas layer,and the concentration of the flue gas.Moreover,when the sprinkler is spread over thewhole transformer,the cooling effect on both the temperature above the fire source and the temperature of the upper flue gas layer is good,whereas the change in the concentration of the flue gas above the fire source is not obvious compared to the case where the sprinkler is not fully spread.
基金supported by the Major Science and Technology Project of Zhongshan City(No.2022AJ004)the Key Basic and Applied Research Program of Guangdong Province(Nos.2019B030302010 and 2022B1515120082)Guangdong Science and Technology Innovation Project(No.2021TX06C111).
文摘In general,the rapid growth of α-Fe clusters is a challenge in high Fe-content Fe-based amorphous alloys,negatively affecting their physical properties.Herein,we introduce an efficient and rapid post-treatment technique known as ultrasonic vibration rapid processing(UVRP),which enables the formation of high-density strong magnetic α-Fe clusters,thereby enhancing the soft magnetic properties of Fe_(78)Si(13)B_(9) amorphous alloy ribbon.
基金supported by the National Natural Science Foundation of China(No.51805265)the Fundamental Research Funds for the Central Universities,China(No.30922010921).
文摘Thin walls of an AZ91 magnesium alloy with fine equiaxed grains were fabricated via cold arc-based wire arc additive manufacturing(CA-WAAM),and the droplet transfer behaviours,microstructures,and mechanical properties were investigated.The results showed that the cold arc process reduced splashing at the moment of liquid bridge breakage and effectively shortened the droplet transfer period.The microstructures of the deposited samples exhibited layered characteristics with alternating distributions of coarse and fine grains.During layer-by-layer deposition,the β-phase precipitated and grew preferentially along grain boundaries,while the fineη-Al_(8)Mn_(5)phase was dispersed in the α-Mg matrix.The mechanical properties of the CA-WAAM deposited sample showed isotropic characteristics.The ultimate tensile strength and elongation in the building direction(BD)were 282.7 MPa and 14.2%,respectively.The microhardness values of the deposited parts were relatively uniform,with an average value of HV 69.6.
文摘Agricultural Products Processing and Storage (ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature) is an international,pect-review ed open access journal with the aim to offer a platform for the rapid dissemination of significant,novel,and high-impact research in the fields of agricultural product processing science,technology,engineering,and nutrition.Additio nally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.
基金financially supported by the National Natural Science Foundation of China(No.52105373)the China Scholarship Council(No.202106020094).
文摘Ti-10V-2Fe-3Al alloy with fine-grainedβphases was fabricated by friction stir processing with opti-mized processing parameters.The superplastic behavior of the specimens was investigated by tensile deformation at different strain rates and temperatures,and an optimal superplastic elongation of 634%was achieved at 700℃ and 3×10^(-4)/s.An annealing treatment at 650℃ for 60 min showed a mi-crostructure withαprecipitates distributed in theβmatrix in the friction stir specimen.Such pre-heat treatment improves the superplasticity of the specimen,achieving an elongation of up to 807%at 750℃ and 3×10^(-4)/s.The influences of tensile temperatures and strain rates on the microstructural evolution,such as grain size variation,grain morphology,and phase transformations,were discussed.The super-plastic deformation behavior of fine-grained Ti-10V-2Fe-3Al alloy is controlled by grain boundary sliding and accompanied by dynamic phase transformation and recrystallization.
