Ferrite-rich calcium sulfoaluminate(FCSA)cement is often used in special projects such as marine engineering due to its excellent resistance of seawater attack although the cost is a little high.Ground granulated blas...Ferrite-rich calcium sulfoaluminate(FCSA)cement is often used in special projects such as marine engineering due to its excellent resistance of seawater attack although the cost is a little high.Ground granulated blast furnace slag(GGBS),a byproduct of industrial production,is used as a mineral admixture to reduce concrete costs and provide excellent performance.This study aimed to investigate the impact of GGBS on the hydration properties of FCSA cement in seawater.Tests were conducted on heat of hydration,compressive strength,mass change,and pH value of pore solution of FCSA cement paste with a water-to-binder ratio of 0.45.X-ray diffraction(XRD)analysis and thermogravimetric analysis were used to determine the hydration products,while mercury intrusion porosimetry(MIP)was used to measure pore structure.The results indicated that the FCSA cement hydration showed a concentrated heat release at early age.The compressive strength of specimens consistently increased over time,where seawater curing enhanced the compressive strength of control samples.The pH value of pore solution decreased to 10.7−10.9 at 90 d when cured in seawater.The primary hydration products of FCSA cement included ettringite,iron hydroxide gel(FH_(3)),and aluminum hydroxide gel(AH_(3)).Moreover,when cured in seawater,Friedel’s salt was formed,which enhanced the compressive strength of the specimen and increased its coefficient of corrosion.Seawater curing gradually increased sample mass,and GGBS refined pore structure while reducing harmful pore proportions.These results suggest that while GGBS can refine pore structure and improve certain aspects of performance,its inclusion may also reduce compressive strength,highlighting the need for a balanced approach in its use for marine applications.展开更多
The use of Chinese herbal medicines can replace antibiotics that cause drug-resistance problems,which are currently necessary for disease control.In this paper,a traditional Chinese medicine compound named Ephedra hou...The use of Chinese herbal medicines can replace antibiotics that cause drug-resistance problems,which are currently necessary for disease control.In this paper,a traditional Chinese medicine compound named Ephedra houttuynia granule for the treatment of Mycoplasma galliscepticum(MG)infection was prepared.Furthermore,its action mechanism was explored through network pharmacology.The optimal extraction and granulation processes of the compound were determined by high performance liquid chromatography(HPLC)method and L9 orthogonal test,and in the treatment experiment,Ephedra houttuynia granule showed a significant therapeutic effect on MG infection.In the study of network pharmacology,the results showed that the core targets of Ephedra houttuynia granule against MG infection were vascular endothelial growth factor(VEGFA),fos proto-oncogene(FOS),prepro-coagulation factor II(F2),etc.,the gene ontology/kyoto encyclopedia of genes and genomes(GO/KEGG)analysis results indicated that the signaling pathways of neuroactive ligand receptor interaction,cAMP,IL-17,T cell receptor,and tumor necrosis factor(TNF)might involve in anti-MG infection.In conclusion,this study would provide a new idea for elucidating the action mechanism of other diseases in veterinary clinic,which had a certain guiding significance.展开更多
The experimental die apparatus of the solid granules medium forming on sheet metal was designed and manufactured.Typical parts,such as conical,parabolic,cylindrical and square-box-shaped components,were successfully t...The experimental die apparatus of the solid granules medium forming on sheet metal was designed and manufactured.Typical parts,such as conical,parabolic,cylindrical and square-box-shaped components,were successfully trial-produced as well.According to the analysis of the changing trends of the cross-section shape and the wall thickness during the process,it can be found that the shape of the free deformation zone of the sheet metal,which is the most critical thinning area,can be described as an approximately spherical cap.According to this forming feature,back pressure deep drawing technology with solid granules medium on sheet metal was proposed to restrain drastic thinning at the bottom of the part through the joint friction effect of solid granules medium,the back pressure tringle and the sheet metal.Therefore,the deep drawing limit of the sheet metal is significantly improved.In order to fabricate thin-walled rotary parts with great drawing ratio and complex cross-sections,a finite element model based on the material property test of the solid granules medium was established to optimize the scheme of the back pressure deep drawing.The effects on the forming performance of sheet metal from back pressure load and the approach of blank holding control were analyzed through this model.展开更多
The aerobic granular sludge was cultivated in a pilot-scale sequencing batch reactor （SBR）, and some of the granules were stored at 8 ℃ for 150 d. Extracellular polymeric substances （EPS） of sludge samples were e...The aerobic granular sludge was cultivated in a pilot-scale sequencing batch reactor （SBR）, and some of the granules were stored at 8 ℃ for 150 d. Extracellular polymeric substances （EPS） of sludge samples were extracted and analyzed during the granulation and storage process. The results show that the contents of protein and EPS increase along with the granulation process, while polysaccharides remain almost unchanged. The content of protein in EPS is almost two-fold larger than that of polysaccharides in granular sludge cultivated with municipal wastewater. Moreover, some of the granules disintegrate during storage, corresponding to the decrease of protein contents in EPS. Three peaks are identified in three-dimensional excitation emission matrix （EEM） fluorescence spectra of the EPS in the aerobic granules. Two peaks （A and B） are attributed to the protein-like fluorophores, and the third （peak C） is related to visible fulvic-like substances. Peak A gradually disappears during storage, while a new peak related to ultraviolet fulvic acid （peak D） is formed. The formation and the stability of aerobic granules are closely dependent on the quantity and composition of EPS proteins. Peak C has no obvious changes during granulation, while the fulvic-like substances present an increase in fluorescence intensities during storage, accompanied with an increase in structural complexity. The fulvie-like substances are also associated with the disintegration of the aerobic granules.展开更多
The new forming process of AA6061 alloy tube, including solution treatment, granule medium internal high-pressure forming and aging treatment, was developed. The AA6061 alloy tube via heat treatment satisfied the form...The new forming process of AA6061 alloy tube, including solution treatment, granule medium internal high-pressure forming and aging treatment, was developed. The AA6061 alloy tube via heat treatment satisfied the forming requirement, and the granule medium internal high pressure forming method for AA6061 alloy tube was also realized by using convenient implementation with low requirement of equipment and flexible design of product. At a solution temperature of 560℃ and time of 120 min, the elongation of the AA6061 extruded tube increases by 300% and the strength and the hardness dramatically decrease too. Therefore, the AA6061 alloy tube meets the requirement of internal high-pressure forming because of the improvement of formability. The experiments shows that the strength and hardness of AA6061 alloy workpiece recover to that of the as-received alloy at an aging temperature of 180℃ and time of 360 min, and the strength of AA6061 alloy workpiece is equal to the base alloy. The typical parts of convex ring tube, stepped shaft tube and hexagonal tube were successfully produced in lab by using the present forming method. The forming tests show that the maximum expansion ratio(MER) of the AA6061 extruded tube increases by 25.5% and the material properties of formed AA6061 alloy tube reached the performance of as-received alloy.展开更多
Hot granule medium pressure forming （HGMF） process is a new process in which granule medium replaces the medium in existing flexible-die hot forming process, such as liquids, gases or viscous medium. Hot forming of ...Hot granule medium pressure forming （HGMF） process is a new process in which granule medium replaces the medium in existing flexible-die hot forming process, such as liquids, gases or viscous medium. Hot forming of light alloy sheet parts can be realized based on the properties of granule medium, such as withstanding high temperature and pressure, filling well, sealing and loading easily. In this work, the forming of AA7075 cylindrical parts by HGMF process is taken as an example to establish the constitutive relation and forming limit diagram （FLD） of AA7075 sheet which is related to temperature by hot uniaxial tensile test of sheet metal. Based on the assumption that granule medium is applied to extended Drucker-Prager linear material model, the finite element model of HGMF process is established and the effect of technological parameters, such as forming temperature, blank-holder gap and drawing ratio, on the sheet metal formability, is studied. The limit drawing ratio curve of AA7075 cylindrical parts at forming temperature of 175-300 ℃ is obtained by HGMF process test, and the limit drawing ratio reaches the maximum value of 1.71 at 250 ℃. The results of numerical simulation are consistent with the results of process test, and the forming force, distribution of wall thichness and form of instability are predicted correctly, which provides reference for the application of HGMF process.展开更多
Hot granule medium pressure forming(HGMF) is a technology in which heat-resistant granules are used to replace liquids or gases in existing flexible-die forming technology as pressure-transfer medium. Considering the ...Hot granule medium pressure forming(HGMF) is a technology in which heat-resistant granules are used to replace liquids or gases in existing flexible-die forming technology as pressure-transfer medium. Considering the characteristic of granule medium that seals and loads easily, the technology provides a new method to realize the hot deep-drawing forming on high strength aluminum alloy sheet. Based on the pressure-transfer performance test of granule medium and the material performance test of AA7075-T6 sheet, plastic mechanics analysis is conducted for the areas, such as the flange area, force-transfer area and free deforming area, of cylindrical parts deep-drawn by HGMF technology, and the function relation of forming pressure is obtained under the condition of nonuniform distribution of internal pressure. The comparison between theoretical result and experimental data shows that larger deviation occurs in the middle and later period of forming process, and the maximum theoretical forming force is less than the experimental value by 24.6%. The variation tendency of the theoretical thickness curve is close to the practical situation, and the theoretical value basically agrees well with experimental value in the flange area and the top area of spherical cap which is in the free deforming area.展开更多
In order to reveal the force transmission features of the granules in the solid granule medium forming(SGMF) technology,the frictional characteristics of the non-metallic granule medium(NGM) under high pressure were i...In order to reveal the force transmission features of the granules in the solid granule medium forming(SGMF) technology,the frictional characteristics of the non-metallic granule medium(NGM) under high pressure were investigated by tests and simulations.And the relevant changing curves of the internal friction coefficient of the granular system under different normal pressures were obtained by self-designed shear test.By the granule volume compression test,the accurate discrete element simulation parameters were obtained,based on this,the discrete element method(DEM) was adopted to reveal the evolution law of the NGM granules movement in the sample shear process from the microscopic view.Based on the DEM,the influence of granule diameter,surface friction coefficient,normal pressure and shear velocity on the internal friction coefficient of the granular system were studied.And the parameters were conducted to be dimensionless by introducing the inertia coefficient.Finally,the expression showing power-law relationship of inertia coefficient,surface friction coefficient and internal friction coefficient is obtained.展开更多
OBJECTIVE To explore the antioxidant effect of Bufei Yishen granules on chronic obstructive pulmo⁃nary disease(COPD)and investigate its underlying mechanism.METHODS Forty-eight rats were randomly divided into normal,m...OBJECTIVE To explore the antioxidant effect of Bufei Yishen granules on chronic obstructive pulmo⁃nary disease(COPD)and investigate its underlying mechanism.METHODS Forty-eight rats were randomly divided into normal,model,Bufei Yishen granules(BY)and N-acetylcysteine(NAC)groups,12 rats in each group.The stable COPD rat model was duplicated by using repeated cigarette smoke exposure combined with Klebsiella bacterial infection for 12 weeks(week 1-12),and the corresponding drugs were administered for the next 8 weeks(week 13-20).Minute volume(MV),tidal volume(TV)and peak expiratory flow(PEF)were measured by whole body plethysmography(WBP)system every 4 weeks.Before sacrificed,forced vital capacity(FVC)and forced expiratory volume 0.1(FEV0.1)were measured byPFT system.The pathological changes of lung tissue were observed by pathological techniques.Heme oxygenase 1(HO-1),superoxide dismutase 1(SOD1)and Nrf2 in lung tissue were measured by immunohisto-hemical method.The total anti oxidizing capability(T-AOC),lipid peroxide(LPO)in rat serum were measured.The expression of Nrf2,HO-1 andγ-glutamyl cysteine synthetase(γ-GCS)mRNA in lung tissue was detected by quantitative polymerase chain reac⁃tion(qPCR).The protein expression of Keap1,Nrf2 and HO-1 in lung tissue were detected by Western blotting.RESULTS①Lung function:compared with normal group,the MV in model group was significantly decreased at week 8(P<0.01),the TV and PEF were significantly decreased at week 4(P<0.01).At week 20,compared with model group,MV,TV,and PEF in the BY and NAC groups were significantly increased(P<0.01);compared with the NAC group,MV,TV,and PEF in BY group were significantly increased(P<0.01).At the end of week 20,the FVC and FEV0.1 in model group were significantly lower than that in normal group(P<0.01).Compared with model group,the FVC and FEV0.1 in the BY and NAC groups were significantly increased(P<0.05).②Oxidative indexes:Compared with Normal group,T-AOCin serum was significantly decreased in Model group,while LPO was significantly increased(P<0.01).Compared with the Model,T-AOC in BY and NAC groups was significantly increased(P<0.01),and the LPO was significantly decreased(P<0.05,P<0.01).There were no difference between the BTG and NAC.③Nrf2 signaling:Nrf2 and HO-1 in lung tissue were mainly expressed in the cytoplasm and part of the nucleus of alveolar epithelial cells.SOD1 protein was mainly distributed in bronchial epithelial cells and alveolar septa.Compared with normal group,the expression of Nrf2 in the model group was increased(P<0.01),and HO-1 and SOD1 were decreased(P<0.01).Compared with the model,the expression of Nrf2 in the BY group was significantly increased(P<0.05),and HO-1 and SOD1 in BY and NAC groups were both increased(P<0.01).Compared with the NAC group,the expression of HO-1 in BY group was increased(P<0.01).Compared with normal group,the Nrf2 mRNA expression of lung tissue in the model was significantly increased(P<0.01),the HO-1 andγ-GCS mRNA was decreased(P<0.01).Compared with model group,the Nrf2,HO-1,andγ-GCS mRNA in the BY group were increased(P<0.01),the HO-1,andγ-GCS mRNA in NAC group were increased(P<0.01).Compared with normal group,the Nrf2 protein expression of lung tissue in the model group was significantly increased(P<0.01),and HO-1 protein expression was significantly decreased(P<0.01).Compared with the model,the Nrf2 and HO-1 protein in NAC and BY groups was significantly increased(P<0.01).CONCLUSION Bufei Yishen gran⁃ules has beneficial curative effect in COPD rats,and has the same antioxidation effect as NAC,the mechanism may be involved in upregulating Nrf2 signaling.展开更多
The granular dynamic shear strength is the same as that of the static one in nature, as found from numerous experiments and investigations. The shear strength is equal to the sum of the internal frictional force and t...The granular dynamic shear strength is the same as that of the static one in nature, as found from numerous experiments and investigations. The shear strength is equal to the sum of the internal frictional force and the cohesive force. The influences of type, shape, size distribution, pore ratio, moisture content and variation of vibration velocity on the dynamic shear strength of granules were studied. Based on numerous vibration shear experiments, the authors investigate the mechanism of dynamic shear strength in granules in terms of the fundamental principle and the relevant theory of modern tribology.展开更多
The author has observed the epithelium and basement membrane of uterus, oviduct and fimbriae in mice under the TEM by oral administration of AgNo<sub>3</sub> tracer. The results showed that there was obvio...The author has observed the epithelium and basement membrane of uterus, oviduct and fimbriae in mice under the TEM by oral administration of AgNo<sub>3</sub> tracer. The results showed that there was obvious deposit of argentum granules outside the basement membrane of mucosal epithelium of the uterus, oviduct and fimbriae as well as outside the basement membrane of uterine glands. And there was dilatation fully filled with high electron-dense argentum granules at the intercellular space just beneath the tight junction between the mucosal epithelial cells of uterus, oviduet, fimbriae. All these finding suggest that the uterus, oviduct and fimbriae serve as barriers to the heavy metal argentum ions.展开更多
The granulability and absorbtivity of sawdust and coke breeze were investigated.These properties are important within the preparation of agglomeration charge.They have a significant impact on plynodynamic batch condit...The granulability and absorbtivity of sawdust and coke breeze were investigated.These properties are important within the preparation of agglomeration charge.They have a significant impact on plynodynamic batch conditions.Ability of materials to wet is a fundamental condition of granulability of materials.Wettability and water absorption of wood with liquids is generally significantly affected by their chemical structure.The important factors affecting the wetting process are undoubtedly the wood moisture content,the value of the surface tension of liquid media and their chemical composition.With increasing moisture content of wood,the time to equilibrium rises.Determination of water absorption and granulability of sawdust was conducted to seek their possible use as a partial replacement of coke dust in the production of the agglomerate.Experiments have been realized with alder,oak and pine sawdust and reference material-coke breeze.These materials were divided to four classes of granularity:supplied material,1-2 mm,0.5-1 mm and less than 0.5 mm.And different liquid media were used:water 16°C,water 60°C,soapy water,lime milk and surfactant.展开更多
A novel method isolated microorganisms in soil granule was built. The key steps included： repeated elutriation of soil by sterilized water, inoculation on the plates with the elutriated sediments, incubation of the p...A novel method isolated microorganisms in soil granule was built. The key steps included： repeated elutriation of soil by sterilized water, inoculation on the plates with the elutriated sediments, incubation of the plates and isolation of the actinomycetes by using selected culture medium. We formulated that most microflora included the dominant actinomycetes in the soil were carried away with the sterilized water in the elutriation procedure, some rare actinomycetes and few other microflora included bacteria were remained in the elutriated sediments, the other microflora were excluded to grew into colonies on the plates by using selective culture medium for actinomycetes in the elutriated sediments. Results showed the supposition. Non-streptomycete actinomycetes were isolated both from black soil samples from Chinese northeast area and compost samples from Chinese central area. Soil fungi in granule were isolated by using the selective conditions to favor fungi. The results showed that the method was effective展开更多
Laboratory experiments were conducted to investigate the transformation and performance of a granular sequence batch reactor(SBR) under the conventional organic loading rate(OLR) condition.Aerobic granules were succes...Laboratory experiments were conducted to investigate the transformation and performance of a granular sequence batch reactor(SBR) under the conventional organic loading rate(OLR) condition.Aerobic granules were successfully cultivated in a SBR by means of alternative feeding load combined with reducing settling time after 60 d operational period.Subsequently,the black fungal granules were presented in reactor because of the filamentous overgrowth on the surface of aerobic granules.A small amount of fungal granules had no effect on the performance of granular SBR.Aerobic granules completely vanished and fungal granules eventually became the dominant species in subsequent 90 d operation after granulation.The three-dimensional excitation emission matrix(EEM) spectra result shows that the extracellular polymeric substances(EPS) component in both granules has no much difference,whereas the content of EPS in fungal granules is higher than that in bacterial granules.Due to their low bioactivity,the chemical oxidation demand(COD) and NH4-N removal efficiencies gradually decrease from 90.4%–96.5% and 99.5% to 71.8% and 32.9% respectively while the fungal granules become dominant in the SBR.展开更多
基金Project(2023DJC182)supported by the Department of Science and Technology of Hubei Province,ChinaProjects(51608402,51602229)supported by the National Natural Science Foundation of ChinaProject(2021-2075-38)supported by the Department of Housing and Urban-Rural Development of Hubei Province,China。
文摘Ferrite-rich calcium sulfoaluminate(FCSA)cement is often used in special projects such as marine engineering due to its excellent resistance of seawater attack although the cost is a little high.Ground granulated blast furnace slag(GGBS),a byproduct of industrial production,is used as a mineral admixture to reduce concrete costs and provide excellent performance.This study aimed to investigate the impact of GGBS on the hydration properties of FCSA cement in seawater.Tests were conducted on heat of hydration,compressive strength,mass change,and pH value of pore solution of FCSA cement paste with a water-to-binder ratio of 0.45.X-ray diffraction(XRD)analysis and thermogravimetric analysis were used to determine the hydration products,while mercury intrusion porosimetry(MIP)was used to measure pore structure.The results indicated that the FCSA cement hydration showed a concentrated heat release at early age.The compressive strength of specimens consistently increased over time,where seawater curing enhanced the compressive strength of control samples.The pH value of pore solution decreased to 10.7−10.9 at 90 d when cured in seawater.The primary hydration products of FCSA cement included ettringite,iron hydroxide gel(FH_(3)),and aluminum hydroxide gel(AH_(3)).Moreover,when cured in seawater,Friedel’s salt was formed,which enhanced the compressive strength of the specimen and increased its coefficient of corrosion.Seawater curing gradually increased sample mass,and GGBS refined pore structure while reducing harmful pore proportions.These results suggest that while GGBS can refine pore structure and improve certain aspects of performance,its inclusion may also reduce compressive strength,highlighting the need for a balanced approach in its use for marine applications.
基金the National Natural Science Foundation of China(32273062,31973005)。
文摘The use of Chinese herbal medicines can replace antibiotics that cause drug-resistance problems,which are currently necessary for disease control.In this paper,a traditional Chinese medicine compound named Ephedra houttuynia granule for the treatment of Mycoplasma galliscepticum(MG)infection was prepared.Furthermore,its action mechanism was explored through network pharmacology.The optimal extraction and granulation processes of the compound were determined by high performance liquid chromatography(HPLC)method and L9 orthogonal test,and in the treatment experiment,Ephedra houttuynia granule showed a significant therapeutic effect on MG infection.In the study of network pharmacology,the results showed that the core targets of Ephedra houttuynia granule against MG infection were vascular endothelial growth factor(VEGFA),fos proto-oncogene(FOS),prepro-coagulation factor II(F2),etc.,the gene ontology/kyoto encyclopedia of genes and genomes(GO/KEGG)analysis results indicated that the signaling pathways of neuroactive ligand receptor interaction,cAMP,IL-17,T cell receptor,and tumor necrosis factor(TNF)might involve in anti-MG infection.In conclusion,this study would provide a new idea for elucidating the action mechanism of other diseases in veterinary clinic,which had a certain guiding significance.
基金Project(50775197) supported by the National Natural Science Foundation of China
文摘The experimental die apparatus of the solid granules medium forming on sheet metal was designed and manufactured.Typical parts,such as conical,parabolic,cylindrical and square-box-shaped components,were successfully trial-produced as well.According to the analysis of the changing trends of the cross-section shape and the wall thickness during the process,it can be found that the shape of the free deformation zone of the sheet metal,which is the most critical thinning area,can be described as an approximately spherical cap.According to this forming feature,back pressure deep drawing technology with solid granules medium on sheet metal was proposed to restrain drastic thinning at the bottom of the part through the joint friction effect of solid granules medium,the back pressure tringle and the sheet metal.Therefore,the deep drawing limit of the sheet metal is significantly improved.In order to fabricate thin-walled rotary parts with great drawing ratio and complex cross-sections,a finite element model based on the material property test of the solid granules medium was established to optimize the scheme of the back pressure deep drawing.The effects on the forming performance of sheet metal from back pressure load and the approach of blank holding control were analyzed through this model.
基金Project(2006AA06Z318) supported by the National High-Tech Research and Development Program of China
文摘The aerobic granular sludge was cultivated in a pilot-scale sequencing batch reactor （SBR）, and some of the granules were stored at 8 ℃ for 150 d. Extracellular polymeric substances （EPS） of sludge samples were extracted and analyzed during the granulation and storage process. The results show that the contents of protein and EPS increase along with the granulation process, while polysaccharides remain almost unchanged. The content of protein in EPS is almost two-fold larger than that of polysaccharides in granular sludge cultivated with municipal wastewater. Moreover, some of the granules disintegrate during storage, corresponding to the decrease of protein contents in EPS. Three peaks are identified in three-dimensional excitation emission matrix （EEM） fluorescence spectra of the EPS in the aerobic granules. Two peaks （A and B） are attributed to the protein-like fluorophores, and the third （peak C） is related to visible fulvic-like substances. Peak A gradually disappears during storage, while a new peak related to ultraviolet fulvic acid （peak D） is formed. The formation and the stability of aerobic granules are closely dependent on the quantity and composition of EPS proteins. Peak C has no obvious changes during granulation, while the fulvic-like substances present an increase in fluorescence intensities during storage, accompanied with an increase in structural complexity. The fulvie-like substances are also associated with the disintegration of the aerobic granules.
基金Project(51305386)supported by the National Natural Science Foundation of ChinaProject(E2013203093)supported by the Natural Science Foundation of Hebei Province,China
文摘The new forming process of AA6061 alloy tube, including solution treatment, granule medium internal high-pressure forming and aging treatment, was developed. The AA6061 alloy tube via heat treatment satisfied the forming requirement, and the granule medium internal high pressure forming method for AA6061 alloy tube was also realized by using convenient implementation with low requirement of equipment and flexible design of product. At a solution temperature of 560℃ and time of 120 min, the elongation of the AA6061 extruded tube increases by 300% and the strength and the hardness dramatically decrease too. Therefore, the AA6061 alloy tube meets the requirement of internal high-pressure forming because of the improvement of formability. The experiments shows that the strength and hardness of AA6061 alloy workpiece recover to that of the as-received alloy at an aging temperature of 180℃ and time of 360 min, and the strength of AA6061 alloy workpiece is equal to the base alloy. The typical parts of convex ring tube, stepped shaft tube and hexagonal tube were successfully produced in lab by using the present forming method. The forming tests show that the maximum expansion ratio(MER) of the AA6061 extruded tube increases by 25.5% and the material properties of formed AA6061 alloy tube reached the performance of as-received alloy.
基金Projects(5130538651305385)supported by the National Natural Science Foundation of ChinaProject(E2013203093)supported by the Natural Science Foundation of Hebei Province,China
文摘Hot granule medium pressure forming （HGMF） process is a new process in which granule medium replaces the medium in existing flexible-die hot forming process, such as liquids, gases or viscous medium. Hot forming of light alloy sheet parts can be realized based on the properties of granule medium, such as withstanding high temperature and pressure, filling well, sealing and loading easily. In this work, the forming of AA7075 cylindrical parts by HGMF process is taken as an example to establish the constitutive relation and forming limit diagram （FLD） of AA7075 sheet which is related to temperature by hot uniaxial tensile test of sheet metal. Based on the assumption that granule medium is applied to extended Drucker-Prager linear material model, the finite element model of HGMF process is established and the effect of technological parameters, such as forming temperature, blank-holder gap and drawing ratio, on the sheet metal formability, is studied. The limit drawing ratio curve of AA7075 cylindrical parts at forming temperature of 175-300 ℃ is obtained by HGMF process test, and the limit drawing ratio reaches the maximum value of 1.71 at 250 ℃. The results of numerical simulation are consistent with the results of process test, and the forming force, distribution of wall thichness and form of instability are predicted correctly, which provides reference for the application of HGMF process.
基金Projects(51305386,51305385)supported by the National Natural Science Foundation of ChinaProject(E2013203093)supported by the Natural Science Foundation of Hebei Province,China
文摘Hot granule medium pressure forming(HGMF) is a technology in which heat-resistant granules are used to replace liquids or gases in existing flexible-die forming technology as pressure-transfer medium. Considering the characteristic of granule medium that seals and loads easily, the technology provides a new method to realize the hot deep-drawing forming on high strength aluminum alloy sheet. Based on the pressure-transfer performance test of granule medium and the material performance test of AA7075-T6 sheet, plastic mechanics analysis is conducted for the areas, such as the flange area, force-transfer area and free deforming area, of cylindrical parts deep-drawn by HGMF technology, and the function relation of forming pressure is obtained under the condition of nonuniform distribution of internal pressure. The comparison between theoretical result and experimental data shows that larger deviation occurs in the middle and later period of forming process, and the maximum theoretical forming force is less than the experimental value by 24.6%. The variation tendency of the theoretical thickness curve is close to the practical situation, and the theoretical value basically agrees well with experimental value in the flange area and the top area of spherical cap which is in the free deforming area.
基金Projects(51305385,51305386)supported by the National Natural Science Foundation of ChinaProject(QN20131080)supported by the Science Research Youth Foundation of Hebei Provincial Colleges and Universities,China
文摘In order to reveal the force transmission features of the granules in the solid granule medium forming(SGMF) technology,the frictional characteristics of the non-metallic granule medium(NGM) under high pressure were investigated by tests and simulations.And the relevant changing curves of the internal friction coefficient of the granular system under different normal pressures were obtained by self-designed shear test.By the granule volume compression test,the accurate discrete element simulation parameters were obtained,based on this,the discrete element method(DEM) was adopted to reveal the evolution law of the NGM granules movement in the sample shear process from the microscopic view.Based on the DEM,the influence of granule diameter,surface friction coefficient,normal pressure and shear velocity on the internal friction coefficient of the granular system were studied.And the parameters were conducted to be dimensionless by introducing the inertia coefficient.Finally,the expression showing power-law relationship of inertia coefficient,surface friction coefficient and internal friction coefficient is obtained.
基金National Natural Science Foundation of China(81130062and 81403367)
文摘OBJECTIVE To explore the antioxidant effect of Bufei Yishen granules on chronic obstructive pulmo⁃nary disease(COPD)and investigate its underlying mechanism.METHODS Forty-eight rats were randomly divided into normal,model,Bufei Yishen granules(BY)and N-acetylcysteine(NAC)groups,12 rats in each group.The stable COPD rat model was duplicated by using repeated cigarette smoke exposure combined with Klebsiella bacterial infection for 12 weeks(week 1-12),and the corresponding drugs were administered for the next 8 weeks(week 13-20).Minute volume(MV),tidal volume(TV)and peak expiratory flow(PEF)were measured by whole body plethysmography(WBP)system every 4 weeks.Before sacrificed,forced vital capacity(FVC)and forced expiratory volume 0.1(FEV0.1)were measured byPFT system.The pathological changes of lung tissue were observed by pathological techniques.Heme oxygenase 1(HO-1),superoxide dismutase 1(SOD1)and Nrf2 in lung tissue were measured by immunohisto-hemical method.The total anti oxidizing capability(T-AOC),lipid peroxide(LPO)in rat serum were measured.The expression of Nrf2,HO-1 andγ-glutamyl cysteine synthetase(γ-GCS)mRNA in lung tissue was detected by quantitative polymerase chain reac⁃tion(qPCR).The protein expression of Keap1,Nrf2 and HO-1 in lung tissue were detected by Western blotting.RESULTS①Lung function:compared with normal group,the MV in model group was significantly decreased at week 8(P<0.01),the TV and PEF were significantly decreased at week 4(P<0.01).At week 20,compared with model group,MV,TV,and PEF in the BY and NAC groups were significantly increased(P<0.01);compared with the NAC group,MV,TV,and PEF in BY group were significantly increased(P<0.01).At the end of week 20,the FVC and FEV0.1 in model group were significantly lower than that in normal group(P<0.01).Compared with model group,the FVC and FEV0.1 in the BY and NAC groups were significantly increased(P<0.05).②Oxidative indexes:Compared with Normal group,T-AOCin serum was significantly decreased in Model group,while LPO was significantly increased(P<0.01).Compared with the Model,T-AOC in BY and NAC groups was significantly increased(P<0.01),and the LPO was significantly decreased(P<0.05,P<0.01).There were no difference between the BTG and NAC.③Nrf2 signaling:Nrf2 and HO-1 in lung tissue were mainly expressed in the cytoplasm and part of the nucleus of alveolar epithelial cells.SOD1 protein was mainly distributed in bronchial epithelial cells and alveolar septa.Compared with normal group,the expression of Nrf2 in the model group was increased(P<0.01),and HO-1 and SOD1 were decreased(P<0.01).Compared with the model,the expression of Nrf2 in the BY group was significantly increased(P<0.05),and HO-1 and SOD1 in BY and NAC groups were both increased(P<0.01).Compared with the NAC group,the expression of HO-1 in BY group was increased(P<0.01).Compared with normal group,the Nrf2 mRNA expression of lung tissue in the model was significantly increased(P<0.01),the HO-1 andγ-GCS mRNA was decreased(P<0.01).Compared with model group,the Nrf2,HO-1,andγ-GCS mRNA in the BY group were increased(P<0.01),the HO-1,andγ-GCS mRNA in NAC group were increased(P<0.01).Compared with normal group,the Nrf2 protein expression of lung tissue in the model group was significantly increased(P<0.01),and HO-1 protein expression was significantly decreased(P<0.01).Compared with the model,the Nrf2 and HO-1 protein in NAC and BY groups was significantly increased(P<0.01).CONCLUSION Bufei Yishen gran⁃ules has beneficial curative effect in COPD rats,and has the same antioxidation effect as NAC,the mechanism may be involved in upregulating Nrf2 signaling.
基金TheNationalNaturalScienceFoundationofChina (No .5 0 0 74 0 34)
文摘The granular dynamic shear strength is the same as that of the static one in nature, as found from numerous experiments and investigations. The shear strength is equal to the sum of the internal frictional force and the cohesive force. The influences of type, shape, size distribution, pore ratio, moisture content and variation of vibration velocity on the dynamic shear strength of granules were studied. Based on numerous vibration shear experiments, the authors investigate the mechanism of dynamic shear strength in granules in terms of the fundamental principle and the relevant theory of modern tribology.
文摘The author has observed the epithelium and basement membrane of uterus, oviduct and fimbriae in mice under the TEM by oral administration of AgNo<sub>3</sub> tracer. The results showed that there was obvious deposit of argentum granules outside the basement membrane of mucosal epithelium of the uterus, oviduct and fimbriae as well as outside the basement membrane of uterine glands. And there was dilatation fully filled with high electron-dense argentum granules at the intercellular space just beneath the tight junction between the mucosal epithelial cells of uterus, oviduet, fimbriae. All these finding suggest that the uterus, oviduct and fimbriae serve as barriers to the heavy metal argentum ions.
基金supported by Slovak Research and Development Agency(APVV),Slovak Republic,No.APVV-0405-11Slovak research and development agency(SRDA),Slovak republic,No.VEGA1/0847/16
文摘The granulability and absorbtivity of sawdust and coke breeze were investigated.These properties are important within the preparation of agglomeration charge.They have a significant impact on plynodynamic batch conditions.Ability of materials to wet is a fundamental condition of granulability of materials.Wettability and water absorption of wood with liquids is generally significantly affected by their chemical structure.The important factors affecting the wetting process are undoubtedly the wood moisture content,the value of the surface tension of liquid media and their chemical composition.With increasing moisture content of wood,the time to equilibrium rises.Determination of water absorption and granulability of sawdust was conducted to seek their possible use as a partial replacement of coke dust in the production of the agglomerate.Experiments have been realized with alder,oak and pine sawdust and reference material-coke breeze.These materials were divided to four classes of granularity:supplied material,1-2 mm,0.5-1 mm and less than 0.5 mm.And different liquid media were used:water 16°C,water 60°C,soapy water,lime milk and surfactant.
基金Supported by the Youth Foundation of College of Resources and Environment of Northeast Agricultural University
文摘A novel method isolated microorganisms in soil granule was built. The key steps included： repeated elutriation of soil by sterilized water, inoculation on the plates with the elutriated sediments, incubation of the plates and isolation of the actinomycetes by using selected culture medium. We formulated that most microflora included the dominant actinomycetes in the soil were carried away with the sterilized water in the elutriation procedure, some rare actinomycetes and few other microflora included bacteria were remained in the elutriated sediments, the other microflora were excluded to grew into colonies on the plates by using selective culture medium for actinomycetes in the elutriated sediments. Results showed the supposition. Non-streptomycete actinomycetes were isolated both from black soil samples from Chinese northeast area and compost samples from Chinese central area. Soil fungi in granule were isolated by using the selective conditions to favor fungi. The results showed that the method was effective
基金Project(51078036) supported by the National Natural Science Foundation of China
文摘Laboratory experiments were conducted to investigate the transformation and performance of a granular sequence batch reactor(SBR) under the conventional organic loading rate(OLR) condition.Aerobic granules were successfully cultivated in a SBR by means of alternative feeding load combined with reducing settling time after 60 d operational period.Subsequently,the black fungal granules were presented in reactor because of the filamentous overgrowth on the surface of aerobic granules.A small amount of fungal granules had no effect on the performance of granular SBR.Aerobic granules completely vanished and fungal granules eventually became the dominant species in subsequent 90 d operation after granulation.The three-dimensional excitation emission matrix(EEM) spectra result shows that the extracellular polymeric substances(EPS) component in both granules has no much difference,whereas the content of EPS in fungal granules is higher than that in bacterial granules.Due to their low bioactivity,the chemical oxidation demand(COD) and NH4-N removal efficiencies gradually decrease from 90.4%–96.5% and 99.5% to 71.8% and 32.9% respectively while the fungal granules become dominant in the SBR.
