In order to produce low-cost titanium(Ti)with high productivity,fundamental studies on producing metallic Ti from titanium dioxide(TiO_(2))in the cold pressed pellets were conducted by metallothermic reduction with an...In order to produce low-cost titanium(Ti)with high productivity,fundamental studies on producing metallic Ti from titanium dioxide(TiO_(2))in the cold pressed pellets were conducted by metallothermic reduction with an indirect contact method.This paper focuses on discussing the mechanism of the reduction process and the relationships of RM(a revised reduction index)with reduction temperature,reduction time,and mole ratio of TiO_(2) to CaCl_(2)(nTiO_(2)/nCaCl_(2))in the pellets.The results show that metallic Ti was obtained from the reduction of TiO_(2) in the pellets by calcium(Ca)vapor;pellets were reduced homogenously and Ca vapor diffused into the porous pellets by Knudsen diffusion or the mixing diffusion of molecular diffusion and Knudsen diffusion at 1273 K;RM increased with the increases of temperature and reduction time and was 96.34%when T_(Redu)=1273 K,t_(Redu)=6 h,and nTiO_(2)/nCaCl_(2)=4;the reasonable nTiO_(2)/nCaCl_(2) value is 3−5 for the pellets with enough strength and high RM.展开更多
The effects of Si content on combinations of important properties such as hardness, hardenability, and weldability in addition to strength increment were systematically investigated to develop a Mo and V free low allo...The effects of Si content on combinations of important properties such as hardness, hardenability, and weldability in addition to strength increment were systematically investigated to develop a Mo and V free low alloy cast steel for automobile cold pressing die insert. For the evaluation of the applicability as the die insert, the mechanical properties were measured after spheroidization annealing （SA）, quenching and tempering （Q/T）, and flame hardening （FH） treatments, respectively. The developed 0.8%-1.6%Si containing Mo and V free alloy cast steels showed excellent matrix strengthening effect, hardenability, and weldability, fulfilling the industrial criterion of the mechanical properties for the die insert.展开更多
Pressing process is a manufacturing method that obtained work piece with certain dimension, shape and capability through die forcing roughcast to produce plastic deformation or separate. This paper focuses on the key ...Pressing process is a manufacturing method that obtained work piece with certain dimension, shape and capability through die forcing roughcast to produce plastic deformation or separate. This paper focuses on the key problems of visualization simulation in pressing die. The final aim is that numerical simulation system can simulate the process of processing forming technique, which can supply some necessary and accurate key parameters for die design. The detail description of mechanical characteristic and key technique of sheet forming technique is discussed. Pressing forming method is one of the most important forming techniques of metal forming, which has special mechanical characteristics. The character of sheet pressing forming is that the deformation of thickness direction is very small in contrast to other directions. The deformation mode of sheet forming mainly has the following kinds: bi-directional stretch, plane stress, stretches, depths extend, bending and counter-bending. The essence of press forming is the transferring course that the transferring region of rough comes to deformation by outside force, which is main researching principle in forming and the transferring field. The analysis of pressing forming course, disclose the feature of stress-strain and their changing rule, then pressing process and forming parameters could be obtained. So the states of force and deformation of transferring region is key to determine character about the varieties of pressing transferring. The paper analyzes these factors, which may influence forming precision in pressing process. In traditional methods, some key parameter such as spring-back, bending radius for die design are calculated by experience formula or select from data table. The paper brings forward the calculation methods of key parameter in the case of drawing finite element method and numerical simulation into pressing die design. In order to calculate the value of key parameters based on data supplied by FEM, a numerical simulation application is finished combined with two descriptions of work piece deformation NURBS and discrete piece. The numerical simulation is programmed on Microsoft Visual C++ with OpenGL as the graphics tool. It establishes numerical simulation program, dynamically simulates the process of sheet pressing figuration, and gets good effects.展开更多
The main objective of this research was to determine the amount of oil fish were extracted from fish west resulted from butchering,cutting and splitting processes before salmon smoking by using cold pressing methods.T...The main objective of this research was to determine the amount of oil fish were extracted from fish west resulted from butchering,cutting and splitting processes before salmon smoking by using cold pressing methods.The amount and the characteristics of extracted of oil were tested at Regional Centre for food and feed the USDA Agricultural Research Center laboratory.The samples were used from fresh Salmon waste about 1000g from each of the(head,skin,viscera,backbone,frames and cuts off).This waste recorded more than 22%of the total mass from salmon fish with used modern extract machine.in this experiment the results revealed the fresh salmon waste have more than 16%of oil fish per one kg of salmon waste.The oil weight from Salmon waste for(head,skin,viscera,backbone,frames and cuts off).was increased with pressing time increase as well as oil productivity increased.The optimum conditions at pressing time was 200 min,for all salmon waste components.Oil productivity fluctuated according to waste sources was 190,210,86,188,178 and 90 g.oil/1000 g.by head,skin,off cuts,terming,,viscera,and backbone frames,Salmon by-products,oil productivity was ranged between 8.60 to 21.00%at constant pressure.High contents of functional EPA(20:5ω3)and DHA(22:6ω3)for oil fish.展开更多
Bio-jet fuel produced from non-edible oilseeds can be an alternative to fossil fuels with the benefits of increasing national energy security, reducing environmental impact, and fostering rural economic growth. Effici...Bio-jet fuel produced from non-edible oilseeds can be an alternative to fossil fuels with the benefits of increasing national energy security, reducing environmental impact, and fostering rural economic growth. Efficient oil extraction from oilseeds is critical for economic production of bio-jet fuels. Oil extractions from camelina (sativa) and canola (Brassica napus) seeds were conducted using a cold press method. The effect of the frequency controlling the screw rotation speed on the oil recovery and quality was discussed. Characterization of the produced raw vegetable oils, such as heating value, elemental content and main chemical compositions, was carried out. The results showed that the oil recovery increased when the frequency decreased. The highest oil recoveries for camelina and canola seeds were 88.2% and 84.1% respectively, both at 15 Hz. The cold press frequency and processing temperature (97.2°C - 106.0°C) had a minor influence on the qualities and recovery of both camelina and canola oils. In addition, camelina and canola oils produced at 15 Hz underwent catalytic cracking to examine potential hydrocarbon fuels production. It was observed that some of oil physicochemical properties were improved after catalytic cracking. Although more study is needed for further improvement of oil recovery and qualities, cold press could be an efficient method for oil extraction from non-edible oilseeds. Additionally, the preliminary results of upgrading the oils produced show very promising for future bio-jet fuels production.展开更多
A combined method of selective laser sintering （SLS） and cold isostatic pressing （CIP） was applied to manufacturing metal parts rapidly. Finite element method was used to predict final dimensions and decrease cost...A combined method of selective laser sintering （SLS） and cold isostatic pressing （CIP） was applied to manufacturing metal parts rapidly. Finite element method was used to predict final dimensions and decrease cost. The simulations of CIP of selective laser sintered parts were carried out by Drucker-Prager-Cap constitutive model with ABAQUS computer program. The property of metal powder was measured by CIP experiments. The results show the rubber bag and the friction coefficient have little influence on results of simulations. The parts only have uniform shrinkage and have no obvious distortion in shape. The results of simulations show a good agreement with the experimental results and the calculated results, indicating that the Drucker-Prager-Cap model is an effective model to simulate CIP process. The simulations could give a useful direction to forming process of the CIP of selective laser sintered components. K展开更多
Aim The piezoelectric properties and cytotoxicity of a porous lead-free piezoelectric ceramic for use as a direct bone substitute were investigated. Methodology Cold isostatic pressing （CIP） was applied to fabricate...Aim The piezoelectric properties and cytotoxicity of a porous lead-free piezoelectric ceramic for use as a direct bone substitute were investigated. Methodology Cold isostatic pressing （CIP） was applied to fabricate porous lithium sodium potassium niobate （Li0.06Na0.5K0.44） NbO3 specimens using a pore-forming method. The morphologies of the CIP-processed specimens were characterized and compared to those of specimens made by from conventional pressing procedures. The effects of the ceramic on the attachment and proliferation of osteoblasts isolated from the cranium of 1-day-old Sprague- Dawley rats were examined by a scanning electron microscopy （SEM） and metbylthiazol tetrazolium （MTT） assay. Results The results showed that CIP enhanced piezoelectricity and biological performance of the niobate specimen, and also promoted an extracellular matrix-like topography of it. In vitro studies showed that the CIP-enhanced material had positive effects on the attachment and proliferation of osteoblasts. Conclusion Niobate ceramic generated by CIP shows a promise for being a piezoelectric composite bone substitute.展开更多
31 cases of common cold were treated with paper-separated moxibustion. An ig-nited moxa-stick was quickly and repeatedly applied to press the paper-separated acupoints until theskin surrounding acupoints being flushed...31 cases of common cold were treated with paper-separated moxibustion. An ig-nited moxa-stick was quickly and repeatedly applied to press the paper-separated acupoints until theskin surrounding acupoints being flushed.Points Fengfu (GV 16), Fengchi (GB 20), Dazhui (GV14), Dazhu (BL 11), Fengmen (BL 12) and Feishu (BL 13) were selected alternatively for moxi-bustion, once a day. Among 31 cases, 14 (45. 1 % ) were cured after one session of treatment, and 15(48. 4% ) cured after two sessions, with the total effective rate of 93.5 %. Its effect was similar tothat of the control drugs (" Xiang Feng Tea" and Sang Ju Ganmao Tablet", P】0. 05). Resultsshowed that this method was quite effective for treatment of common cold with either cold or heatsyndromes and also could reduce acute attacks of chronic bronchitis.展开更多
Passive daytime radiative cooling has great potential for energy conservation and sustainable development.Polymer-based radiative cooling materials have received much attention due to their excellent cooling performan...Passive daytime radiative cooling has great potential for energy conservation and sustainable development.Polymer-based radiative cooling materials have received much attention due to their excellent cooling performance and scalable potential.However,the use of large amounts of organic solvents,the long cycle time,and the complexity of the preparation process have limited their development.Herein,we report a two-step cold-press sintering method for the preparation of a polymer radiative cooler,which is free of organic solvents.For demonstration,a polyvinylidene fluoride-hexafluoropropylene copolymer(PVDF-HFP)coating with a solar reflectance of 97.4%and an emissivity of 0.969 within the atmospheric window is prepared,which can achieve a sub-ambient cooling phenomenon with a temperature reduction of 4.8℃.Besides,the maximal radiative cooling power of 50.2 W/m^(2)is also obtained under sunlight.After the implementation of the proposed sintered PVDF-HFP coating in buildings,more than 10%of annual energy consumption can be saved in China.This work proposes a simple,environmentally friendly,and scalable processing method for the preparation of radiative cooling materials,facilitating the large-scale application of radiative cooling technology.展开更多
基金Projects(51774071,50804007,51974073)supported by the National Natural Science Foundation of China。
文摘In order to produce low-cost titanium(Ti)with high productivity,fundamental studies on producing metallic Ti from titanium dioxide(TiO_(2))in the cold pressed pellets were conducted by metallothermic reduction with an indirect contact method.This paper focuses on discussing the mechanism of the reduction process and the relationships of RM(a revised reduction index)with reduction temperature,reduction time,and mole ratio of TiO_(2) to CaCl_(2)(nTiO_(2)/nCaCl_(2))in the pellets.The results show that metallic Ti was obtained from the reduction of TiO_(2) in the pellets by calcium(Ca)vapor;pellets were reduced homogenously and Ca vapor diffused into the porous pellets by Knudsen diffusion or the mixing diffusion of molecular diffusion and Knudsen diffusion at 1273 K;RM increased with the increases of temperature and reduction time and was 96.34%when T_(Redu)=1273 K,t_(Redu)=6 h,and nTiO_(2)/nCaCl_(2)=4;the reasonable nTiO_(2)/nCaCl_(2) value is 3−5 for the pellets with enough strength and high RM.
文摘The effects of Si content on combinations of important properties such as hardness, hardenability, and weldability in addition to strength increment were systematically investigated to develop a Mo and V free low alloy cast steel for automobile cold pressing die insert. For the evaluation of the applicability as the die insert, the mechanical properties were measured after spheroidization annealing （SA）, quenching and tempering （Q/T）, and flame hardening （FH） treatments, respectively. The developed 0.8%-1.6%Si containing Mo and V free alloy cast steels showed excellent matrix strengthening effect, hardenability, and weldability, fulfilling the industrial criterion of the mechanical properties for the die insert.
文摘Pressing process is a manufacturing method that obtained work piece with certain dimension, shape and capability through die forcing roughcast to produce plastic deformation or separate. This paper focuses on the key problems of visualization simulation in pressing die. The final aim is that numerical simulation system can simulate the process of processing forming technique, which can supply some necessary and accurate key parameters for die design. The detail description of mechanical characteristic and key technique of sheet forming technique is discussed. Pressing forming method is one of the most important forming techniques of metal forming, which has special mechanical characteristics. The character of sheet pressing forming is that the deformation of thickness direction is very small in contrast to other directions. The deformation mode of sheet forming mainly has the following kinds: bi-directional stretch, plane stress, stretches, depths extend, bending and counter-bending. The essence of press forming is the transferring course that the transferring region of rough comes to deformation by outside force, which is main researching principle in forming and the transferring field. The analysis of pressing forming course, disclose the feature of stress-strain and their changing rule, then pressing process and forming parameters could be obtained. So the states of force and deformation of transferring region is key to determine character about the varieties of pressing transferring. The paper analyzes these factors, which may influence forming precision in pressing process. In traditional methods, some key parameter such as spring-back, bending radius for die design are calculated by experience formula or select from data table. The paper brings forward the calculation methods of key parameter in the case of drawing finite element method and numerical simulation into pressing die design. In order to calculate the value of key parameters based on data supplied by FEM, a numerical simulation application is finished combined with two descriptions of work piece deformation NURBS and discrete piece. The numerical simulation is programmed on Microsoft Visual C++ with OpenGL as the graphics tool. It establishes numerical simulation program, dynamically simulates the process of sheet pressing figuration, and gets good effects.
文摘The main objective of this research was to determine the amount of oil fish were extracted from fish west resulted from butchering,cutting and splitting processes before salmon smoking by using cold pressing methods.The amount and the characteristics of extracted of oil were tested at Regional Centre for food and feed the USDA Agricultural Research Center laboratory.The samples were used from fresh Salmon waste about 1000g from each of the(head,skin,viscera,backbone,frames and cuts off).This waste recorded more than 22%of the total mass from salmon fish with used modern extract machine.in this experiment the results revealed the fresh salmon waste have more than 16%of oil fish per one kg of salmon waste.The oil weight from Salmon waste for(head,skin,viscera,backbone,frames and cuts off).was increased with pressing time increase as well as oil productivity increased.The optimum conditions at pressing time was 200 min,for all salmon waste components.Oil productivity fluctuated according to waste sources was 190,210,86,188,178 and 90 g.oil/1000 g.by head,skin,off cuts,terming,,viscera,and backbone frames,Salmon by-products,oil productivity was ranged between 8.60 to 21.00%at constant pressure.High contents of functional EPA(20:5ω3)and DHA(22:6ω3)for oil fish.
文摘Bio-jet fuel produced from non-edible oilseeds can be an alternative to fossil fuels with the benefits of increasing national energy security, reducing environmental impact, and fostering rural economic growth. Efficient oil extraction from oilseeds is critical for economic production of bio-jet fuels. Oil extractions from camelina (sativa) and canola (Brassica napus) seeds were conducted using a cold press method. The effect of the frequency controlling the screw rotation speed on the oil recovery and quality was discussed. Characterization of the produced raw vegetable oils, such as heating value, elemental content and main chemical compositions, was carried out. The results showed that the oil recovery increased when the frequency decreased. The highest oil recoveries for camelina and canola seeds were 88.2% and 84.1% respectively, both at 15 Hz. The cold press frequency and processing temperature (97.2°C - 106.0°C) had a minor influence on the qualities and recovery of both camelina and canola oils. In addition, camelina and canola oils produced at 15 Hz underwent catalytic cracking to examine potential hydrocarbon fuels production. It was observed that some of oil physicochemical properties were improved after catalytic cracking. Although more study is needed for further improvement of oil recovery and qualities, cold press could be an efficient method for oil extraction from non-edible oilseeds. Additionally, the preliminary results of upgrading the oils produced show very promising for future bio-jet fuels production.
基金Project(2007AA03Z115) supported by the High-Tech Research and Development Program of China
文摘A combined method of selective laser sintering （SLS） and cold isostatic pressing （CIP） was applied to manufacturing metal parts rapidly. Finite element method was used to predict final dimensions and decrease cost. The simulations of CIP of selective laser sintered parts were carried out by Drucker-Prager-Cap constitutive model with ABAQUS computer program. The property of metal powder was measured by CIP experiments. The results show the rubber bag and the friction coefficient have little influence on results of simulations. The parts only have uniform shrinkage and have no obvious distortion in shape. The results of simulations show a good agreement with the experimental results and the calculated results, indicating that the Drucker-Prager-Cap model is an effective model to simulate CIP process. The simulations could give a useful direction to forming process of the CIP of selective laser sintered components. K
基金supported by the National Natural Science Foundation of China (59972020)
文摘Aim The piezoelectric properties and cytotoxicity of a porous lead-free piezoelectric ceramic for use as a direct bone substitute were investigated. Methodology Cold isostatic pressing （CIP） was applied to fabricate porous lithium sodium potassium niobate （Li0.06Na0.5K0.44） NbO3 specimens using a pore-forming method. The morphologies of the CIP-processed specimens were characterized and compared to those of specimens made by from conventional pressing procedures. The effects of the ceramic on the attachment and proliferation of osteoblasts isolated from the cranium of 1-day-old Sprague- Dawley rats were examined by a scanning electron microscopy （SEM） and metbylthiazol tetrazolium （MTT） assay. Results The results showed that CIP enhanced piezoelectricity and biological performance of the niobate specimen, and also promoted an extracellular matrix-like topography of it. In vitro studies showed that the CIP-enhanced material had positive effects on the attachment and proliferation of osteoblasts. Conclusion Niobate ceramic generated by CIP shows a promise for being a piezoelectric composite bone substitute.
文摘31 cases of common cold were treated with paper-separated moxibustion. An ig-nited moxa-stick was quickly and repeatedly applied to press the paper-separated acupoints until theskin surrounding acupoints being flushed.Points Fengfu (GV 16), Fengchi (GB 20), Dazhui (GV14), Dazhu (BL 11), Fengmen (BL 12) and Feishu (BL 13) were selected alternatively for moxi-bustion, once a day. Among 31 cases, 14 (45. 1 % ) were cured after one session of treatment, and 15(48. 4% ) cured after two sessions, with the total effective rate of 93.5 %. Its effect was similar tothat of the control drugs (" Xiang Feng Tea" and Sang Ju Ganmao Tablet", P】0. 05). Resultsshowed that this method was quite effective for treatment of common cold with either cold or heatsyndromes and also could reduce acute attacks of chronic bronchitis.
基金supported by the National Natural Science Foundation of China(NSFC 52130601 and 52106276)the Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)+1 种基金the University of Science and Technology of China-Southwest University of Science and Technology Counterpart Cooperation and Development Joint Fund(24LHJJ09)the USTC Center for Micro and Nanoscale Research and Fabrication。
文摘Passive daytime radiative cooling has great potential for energy conservation and sustainable development.Polymer-based radiative cooling materials have received much attention due to their excellent cooling performance and scalable potential.However,the use of large amounts of organic solvents,the long cycle time,and the complexity of the preparation process have limited their development.Herein,we report a two-step cold-press sintering method for the preparation of a polymer radiative cooler,which is free of organic solvents.For demonstration,a polyvinylidene fluoride-hexafluoropropylene copolymer(PVDF-HFP)coating with a solar reflectance of 97.4%and an emissivity of 0.969 within the atmospheric window is prepared,which can achieve a sub-ambient cooling phenomenon with a temperature reduction of 4.8℃.Besides,the maximal radiative cooling power of 50.2 W/m^(2)is also obtained under sunlight.After the implementation of the proposed sintered PVDF-HFP coating in buildings,more than 10%of annual energy consumption can be saved in China.This work proposes a simple,environmentally friendly,and scalable processing method for the preparation of radiative cooling materials,facilitating the large-scale application of radiative cooling technology.
