Micro-scale Al-Zn-Mg/Fe composite powders (MAF) with high reactivity and good storage properties were prepared by reducing iron onto the surface of Al-Zn-Mg alloy powders. Experimental results show that MAF as advance...Micro-scale Al-Zn-Mg/Fe composite powders (MAF) with high reactivity and good storage properties were prepared by reducing iron onto the surface of Al-Zn-Mg alloy powders. Experimental results show that MAF as advanced zero-valent iron are highly effective for degradation of chlorinated organic compounds. The efficiency of degradation for carbon tetrachloride and perchloroethylene is higher than 99% within a period of 2 h. The efficiency of degradation for trichloroethylene by MAF after storing for one month is equivalent to that by freshly prepared nano-size zero-valent iron particles.展开更多
Protein powders from Eisenia foetida were prepared using different drying processes and fractionation. Differential scanning calorimetry was used to show that heat denaturation occurred during the drying process above...Protein powders from Eisenia foetida were prepared using different drying processes and fractionation. Differential scanning calorimetry was used to show that heat denaturation occurred during the drying process above 42°C. Protein solubility was also studied. The addition of dissociating reagents allowed concluding that solubility was decreased during oven drying due to thermo denaturation including hydrogen bonds. The volatile compounds of the different powders were extracted by solid phase micro-extraction and identified by mass spectrometry. Volatile compounds were related to lipid oxidation and Maillard reactions occurring during the preparation of the powders. High drying temperatures led to more volatile compounds resulting from Maillard reactions. In the protein powder preparation process, a fractionation step led to a “pulp fraction” and a “juice fraction” of earthworms. The “pulp fraction” contained less odorant volatile compounds resulting from Maillard reactions than the “juice fraction” did.展开更多
Spray-drying was used to produce the high emissivity NiCr2O4 powders with a spinel structure. Preliminary investigations focused on fabricating the high emissivity powders for infrared radiation coatings and finding t...Spray-drying was used to produce the high emissivity NiCr2O4 powders with a spinel structure. Preliminary investigations focused on fabricating the high emissivity powders for infrared radiation coatings and finding the relationship between microstructure and emissivity. The NiCr2O4 powders were characterized for composition, microstructure, and infrared emissivity by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared radiant instrument, and Fourier transform infrared spectra (FT-IR). Thermogravimetry and differential thermal analysis show that the appropriate baking temperature for NiCr2O4 powder preparation is about 1200?C. The emissivity measurement and FT-IR spectra show that, because of the special spinel structure, the NiCr2O4 powders have a high emissivity about 0.91. Spray-drying is a suitable method to produce the high emissivity ceramic powders.展开更多
Nanosized copper powders were prepared by a gel-casting method using copper nitrate, acrylamide(AM) and N, N′-methylenebisacrylamide(MBAM) as the main raw materials. The as-prepared copper powders were characteri...Nanosized copper powders were prepared by a gel-casting method using copper nitrate, acrylamide(AM) and N, N′-methylenebisacrylamide(MBAM) as the main raw materials. The as-prepared copper powders were characterized by X-ray diffractometry and scanning electron microscopy, and then added into a 48# industrial white oil. Dispersion and wear properties of the compounded lubricating oil were tested. The results show that the copper powders prepared are of high purity, fine dispersibility with mean particle size of about 60 nm and with a narrow particle size distribution. The nanosized copper powders can be well dispersed in the lubricating oil. The addition of the copper powders obviously improves the anti-wear properties of the lubricating oil owing to their good self-repairing performance. Compared with 48# industrial white lubricating oil, the friction coefficient of GCr15 steel with the compounded oil containing 0.6% copper powders reduces by 0.07 and nearly no wear chippings are found in the scratches of the friction counter parts.展开更多
The oxidation behavior of different SiAlON phases(β-SiAlON,X-phase SiAlON and 12H powders) synthesized from coal gangue in air atmosphere was investigated using isothermal thermogravimetry(TG) and field-emission ...The oxidation behavior of different SiAlON phases(β-SiAlON,X-phase SiAlON and 12H powders) synthesized from coal gangue in air atmosphere was investigated using isothermal thermogravimetry(TG) and field-emission scanning electron microscopy(FE-SEM).The effect of ferric oxide impurities in coal gangue was studied.The results show that ferric oxide contributes to the growth of SiAlON crystalline during the synthesis process.In the oxidation experiment,the existence of ferric oxide decreases the oxidation resistance of SiAlON.The reason is that the impurity causes the formation of a liquid phase at a higher temperature.At 1423-1623 K,the oxidation of SiAlON powders is diffusion controlled and it can be described by Chou's model.A fair agreement is found between theoretical calculations and the experimental data.展开更多
It was shown by TEM and X-ray analysis that there are four types of grains of the main Ni3Al phase in the structure of the intermetallic obtained by the self-propagation high temperature method (SHS). Every type of gr...It was shown by TEM and X-ray analysis that there are four types of grains of the main Ni3Al phase in the structure of the intermetallic obtained by the self-propagation high temperature method (SHS). Every type of grains has its own domain and dislocation structure. There are mono- and polydomains with and without dislocations. The grains of the main phase of monoand polydomains without dislocations and polydomains with dislocations were formed by diffusion in the solid phase. In these conditions NiAl3 phase is located on the grain boundary of the main phase. The Ni2Al3 phase is located at the triple joints of the main phase.展开更多
The Ni_3B phase was formed when boron (0.5 at. pct B) was added to the intermetallic of sto- ichiometric and off-stoichiometric (Ni-24 at. pct Al) compounds. In the alloy of stoichiometric composition the particles o...The Ni_3B phase was formed when boron (0.5 at. pct B) was added to the intermetallic of sto- ichiometric and off-stoichiometric (Ni-24 at. pct Al) compounds. In the alloy of stoichiometric composition the particles of Ni_3B phase has the size around 0.1μm and is located on the grain boundary of the main phase. The decreasing of concentrations of Al in the ofF-stoichiometric alloy leads to increase in the degree of the long-range order parameter, increasing the concen- trations of boron in the solid solution and decreasing its localization on the grain boundary. Microalloying of boron leads to increasing in the fraction of grain monodomains with disloca- tions up to 0.7 in the alloy of the off-stoichiometric composition and up to 1 in the alloy of the stoichiometric composition. It was established the correlation between the degree of the concentration inhomogeneity, average density of the dislocations and the average long range-order parameter.展开更多
A new compound Ba6Ti7Nb9O42 was prepared for the first time by solid state reaction in BaO-TiO2-Nb2O5, ternary system. The X-ray powder diffraction data of the title compound was determined. Ba6Ti7Nb9O42 crystallizes ...A new compound Ba6Ti7Nb9O42 was prepared for the first time by solid state reaction in BaO-TiO2-Nb2O5, ternary system. The X-ray powder diffraction data of the title compound was determined. Ba6Ti7Nb9O42 crystallizes in the hexagonal system -with unit cell parameters a=9.0527(4) A,c=11.790(1) A,and space group P63/mcm(193),z=1. The calculated and measured densities are 5. 293 g/cm3 and 5.285 g/cm3, respectively.展开更多
According to the proportion of 1:1, konjac flour and mulberry leaf powder are compounded into a kind of dietary fiber source(KMCP). It is found to be good for anti-inflammation. However, its precise anti-allergic rhin...According to the proportion of 1:1, konjac flour and mulberry leaf powder are compounded into a kind of dietary fiber source(KMCP). It is found to be good for anti-inflammation. However, its precise anti-allergic rhinitis effect and mechanism remain unknown. In our work, the effect of KMCP on allergic rhinitis(AR)induced by ovalbumin(OVA)was investigated. We found that the number of nasal rubbing and sneezing, the eosinophil(EOS)count in the nasal mucosa, and the serum levels of histamine(HIS), OVA-specific immunoglobulin E(OVA-sIgE)and interleukin-4(IL-4)were decreased, and the histopathological changes of nasal mucosa were inhibited. Additionally, the experiments further proved that the KMCP treatment could exert substantial effects on short-chain fatty acids(SCFAs)metabolism in the cecum as well. Overall findings suggest that KMCP could suppress the inflammatory response in AR mice, and serve as a novel curative therapeutic for AR without side effects.展开更多
Chronic refractory w ounds are common and frequently-seen diseases in surgery.Due to their long course of disease and complex pathogeneses,chronic refractory w ounds arouse high attention in clinic.With the preliminar...Chronic refractory w ounds are common and frequently-seen diseases in surgery.Due to their long course of disease and complex pathogeneses,chronic refractory w ounds arouse high attention in clinic.With the preliminary results of clinical research of their pathogeneses and new treatments achieved,traditional Chinese medicine(TCM),w ith its unique concept,breaks the limitation commonly existing in the methods of w estern medicine,especially obtaining certain achievements in chronic refractory w ounds.This paper review ed the therapeutic effects of compound Baiyu pow der in the treatment of chronic refractory w ounds to prove to be effective,convenient to use and save medical costs.展开更多
Carbonated recycled powder as cementitious auxiliary material can reduce carbon emissions and realize high-quality recycling of recycled concrete.In this paper,microscopic property of recycled powder with three carbon...Carbonated recycled powder as cementitious auxiliary material can reduce carbon emissions and realize high-quality recycling of recycled concrete.In this paper,microscopic property of recycled powder with three carbonation methods was tested through XRD and SEM,the mechanical property and microstructure of recycled powder mortar with three replacement rates were studied by ISO method and SEM,and the strengthening mechanism was analyzed.The results showed that the mechanical property of recycled powder mortar decreased with the increasing of replacement rate.It is suggested that the replacement rate of recycled powder should not exceed 20%.The strength index and activity index of carbonated recycled powder mortar were improved,in which the flexural strength was increased by 27.85%and compressive strength was increased by 20%at the maximum.Recycled powder can be quickly and completely carbonated,and the improvement effect of CH pre-soaking carbonation was the best.The activity index of carbonated recycled powder can meet the requirements of Grade II technical standard for recycled powder.Microscopic results revealed the activation mechanism of carbonated recycled powder such as surplus calcium source effect,alkaline polycondensation effect and carbonation enhancement effect.展开更多
The Al-Si-Mg alloy which can be strengthened by heat treatment is widely applied to the key components of aerospace and aeronautics. Iron-rich intermetallic compounds are well known to be strongly influential on mecha...The Al-Si-Mg alloy which can be strengthened by heat treatment is widely applied to the key components of aerospace and aeronautics. Iron-rich intermetallic compounds are well known to be strongly influential on mechanical properties in Al-Si-Mg alloys. But intermetallic compounds in cast Al-Si-Mg alloy intermetallics are often misidentified in previous metallurgical studies. It was described as many different compounds, such as AlFeSi, Al8Fe2Si, Al5(Fe, Mn)3Si2 and so on. For the purpose of solving this problem, the intermetallic compounds in cast Al-Si alloys containing 0.5% Mg were investigated in this study. The iron-rich compounds in Al-Si-Mg casting alloys were characterized by optical microscope(OM), scanning electron microscope(SEM), energy dispersive X-ray spectrometer(EDS), electron backscatter diffraction(EBSD) and X-ray powder diffraction(XRD). The electron backscatter diffraction patterns were used to assess the crystallographic characteristics of intermetallic compounds. The compound which contains Fe/Mg-rich particles with coarse morphologies was Al8FeMg3Si6 in the alloy by using EBSD. The compound belongs to hexagonal system, space group P6_2m, with the lattice parameter a=0.662 nm, c=0.792 nm. The β-phase is indexed as tetragonal Al3FeSi2, space group I4/mcm, a=0.607 nm and c=0.950 nm. The XRD data indicate that Al8FeMg3Si6 and Al3FeSi2 are present in the microstructure of Al-7Si-Mg alloy, which confirms the identification result of EBSD. The present study identified the iron-rich compound in Al-Si-Mg alloy, which provides a reliable method to identify the intermetallic compounds in short time in Al-Si-Mg alloy. Study results are helpful for identification of complex compounds in alloys.展开更多
In this study, rat models of Parkinson's disease induced by substantia nigra injection of 6-hydroxy-dopamine were intragastrically administered Zhichan powder daily for 50 days. Reverse transcription PCR results show...In this study, rat models of Parkinson's disease induced by substantia nigra injection of 6-hydroxy-dopamine were intragastrically administered Zhichan powder daily for 50 days. Reverse transcription PCR results showed that tyrosine hydroxylase mRNA expression in the rat substantia nigra was significantly increased, while monoamine oxidase B mRNA expression was significantly decreased in the Zhichan powder group, compared with the model group. In addition, the levels of striatal dopamine and homovanillic acid, the ratio of dopamine to homovanillic acid, and the activity of blood superoxide dismutase were all higher in the Zhichan powder group than in the model group but the content of malondialdehyde in blood was lower. Our experimental findings indicate that Zhichan powder has an antioxidant effect, it can regulate the expression of monoamine oxidase B and tyrosine hydroxylase in the substantia nigra of Parkinson's disease rats, and it can facilitate the secretion of striatal dopamine and its metabolite homovanillic acid.展开更多
The production of Y2O3-ZrO2 powder by the reaction of zirconium salt and yttrium salt, combined in a certain proportion, with sodium nitrate under molten state was described. The effects of adding Cl-, Br- and CO2-3 a...The production of Y2O3-ZrO2 powder by the reaction of zirconium salt and yttrium salt, combined in a certain proportion, with sodium nitrate under molten state was described. The effects of adding Cl-, Br- and CO2-3 anions, as well as introducing ultrasonic vibration during the reaction on the crystallite size of Y2O3-Zr2O3 powder were investigated.展开更多
Ultrafine alumina power was obtained by calcining the precursor at 1 200 ℃ for 2 h, which was prepared by homogeneous precipitation method using aluminium salts and urea as raw materials. The effects of anions on the...Ultrafine alumina power was obtained by calcining the precursor at 1 200 ℃ for 2 h, which was prepared by homogeneous precipitation method using aluminium salts and urea as raw materials. The effects of anions on the morphology, particle size, surface area and configuration of the precursors were studied. The results show that the reactions of urea with aluminium nitrate and aluminium chloride result in agglomerates gels with bad filtering performance, the morphology is fibrillar. Aluminium sulphate-urea reactions result in the direct formation of amorphous powders with good filtering performance, of which morphology are regular spherical particles with larger granularity and smaller surface area. The reaction of mutual compound of aluminium sulphate and aluminium nitrate with molar ratio of 40:60 with urea can produce precursor with good filtering performance, spherical morphology, and uniform granularity distribution in the particle size range of 2-3 μm.展开更多
To satisfy practical requirements from industrial applications, an alternate route for synthesis compound ultrafine CeO2 powders by wet-solid-phase mechanochemical modification using industrial grade hydrated cerium c...To satisfy practical requirements from industrial applications, an alternate route for synthesis compound ultrafine CeO2 powders by wet-solid-phase mechanochemical modification using industrial grade hydrated cerium carbonate as raw material was proposed.The effect of modifier reaction percentage, reaction time, calcining temperature and modifier amount on particle size, density, suspensibility, and hardness of compound CeO2 powder was investigated.The phase evolutions of preparation process were characterized by XRD.SEM micrograph of the final product shows that compound CeO2 powders obtained are well-dispersed, spherically-shaped, uniformly-sized and submicron-sized particles.The method is readily available in raw material, low in cost, simple in process, and has great potential for industrialization.The compound CeO2 powders of different physical properties can be synthesized by controlling the above-mentioned influence factors in preparation process.展开更多
Objective:To assess the efficacy of compound Bai Yu San(CBYS)as a new treatment option,in healing diabetic skin ulcer.Materials and Methods:A total of 64 diabetic patients with skin ulcer were enrolled and randomly as...Objective:To assess the efficacy of compound Bai Yu San(CBYS)as a new treatment option,in healing diabetic skin ulcer.Materials and Methods:A total of 64 diabetic patients with skin ulcer were enrolled and randomly assigned to experimental group(n=33)and control group(n=31).In the control group,normal saline(NS)was used to cleanse the wound.After debridement,the wound was dressed with modern materials.In the experimental group,the NS‑cleansed wound was dressed with CBYS.The infection rate,healing rate,treatment cost,and patient satisfaction between the two groups were compared.Results:On the 35th day after treatment,the infection rate and healing rate showed no between‑group difference(P>0.05);the experimental group showed lower treatment cost and higher satisfaction than the control group(P<0.05).Conclusion:As a new treatment option for diabetes‑induced skin ulcer,CBYS can effectively control the infection,promote the healing,reduce treatment cost,and increase patient satisfaction.Dressing with CBYS can be clinically replicated in the treatment of diabetic skin ulcer.展开更多
The mixture of Fe and Al powder was mechanically activated and sintered to study a non-melting methodof producing the intermetallics Fe3Al. High-energy ball milling was used as an activation method, X-ray diffractiona...The mixture of Fe and Al powder was mechanically activated and sintered to study a non-melting methodof producing the intermetallics Fe3Al. High-energy ball milling was used as an activation method, X-ray diffractionand SEM were chosen to analyze the materials variation before and after activation and sintering, and hot press ofFe-Al powder was inveshgated to compare mechanical activation with sintering. The results show that combiningmechanical activation with reaction sintering can complete the transformation from pure Fe and Al powder to intermetallics. It is difficult to do the transformation by either mechanical activation or hot press.展开更多
文摘Micro-scale Al-Zn-Mg/Fe composite powders (MAF) with high reactivity and good storage properties were prepared by reducing iron onto the surface of Al-Zn-Mg alloy powders. Experimental results show that MAF as advanced zero-valent iron are highly effective for degradation of chlorinated organic compounds. The efficiency of degradation for carbon tetrachloride and perchloroethylene is higher than 99% within a period of 2 h. The efficiency of degradation for trichloroethylene by MAF after storing for one month is equivalent to that by freshly prepared nano-size zero-valent iron particles.
文摘Protein powders from Eisenia foetida were prepared using different drying processes and fractionation. Differential scanning calorimetry was used to show that heat denaturation occurred during the drying process above 42°C. Protein solubility was also studied. The addition of dissociating reagents allowed concluding that solubility was decreased during oven drying due to thermo denaturation including hydrogen bonds. The volatile compounds of the different powders were extracted by solid phase micro-extraction and identified by mass spectrometry. Volatile compounds were related to lipid oxidation and Maillard reactions occurring during the preparation of the powders. High drying temperatures led to more volatile compounds resulting from Maillard reactions. In the protein powder preparation process, a fractionation step led to a “pulp fraction” and a “juice fraction” of earthworms. The “pulp fraction” contained less odorant volatile compounds resulting from Maillard reactions than the “juice fraction” did.
文摘Spray-drying was used to produce the high emissivity NiCr2O4 powders with a spinel structure. Preliminary investigations focused on fabricating the high emissivity powders for infrared radiation coatings and finding the relationship between microstructure and emissivity. The NiCr2O4 powders were characterized for composition, microstructure, and infrared emissivity by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared radiant instrument, and Fourier transform infrared spectra (FT-IR). Thermogravimetry and differential thermal analysis show that the appropriate baking temperature for NiCr2O4 powder preparation is about 1200?C. The emissivity measurement and FT-IR spectra show that, because of the special spinel structure, the NiCr2O4 powders have a high emissivity about 0.91. Spray-drying is a suitable method to produce the high emissivity ceramic powders.
基金Project(51674095)supported by the National Natural Science Foundation of China
文摘Nanosized copper powders were prepared by a gel-casting method using copper nitrate, acrylamide(AM) and N, N′-methylenebisacrylamide(MBAM) as the main raw materials. The as-prepared copper powders were characterized by X-ray diffractometry and scanning electron microscopy, and then added into a 48# industrial white oil. Dispersion and wear properties of the compounded lubricating oil were tested. The results show that the copper powders prepared are of high purity, fine dispersibility with mean particle size of about 60 nm and with a narrow particle size distribution. The nanosized copper powders can be well dispersed in the lubricating oil. The addition of the copper powders obviously improves the anti-wear properties of the lubricating oil owing to their good self-repairing performance. Compared with 48# industrial white lubricating oil, the friction coefficient of GCr15 steel with the compounded oil containing 0.6% copper powders reduces by 0.07 and nearly no wear chippings are found in the scratches of the friction counter parts.
基金supported by the National Natural Science Foundation of China(No.50874013)the support from the Key Lab. of the Ministry of Education of China for Ecologic & Recycle Metallurgy,University of Science and Technology Beijing
文摘The oxidation behavior of different SiAlON phases(β-SiAlON,X-phase SiAlON and 12H powders) synthesized from coal gangue in air atmosphere was investigated using isothermal thermogravimetry(TG) and field-emission scanning electron microscopy(FE-SEM).The effect of ferric oxide impurities in coal gangue was studied.The results show that ferric oxide contributes to the growth of SiAlON crystalline during the synthesis process.In the oxidation experiment,the existence of ferric oxide decreases the oxidation resistance of SiAlON.The reason is that the impurity causes the formation of a liquid phase at a higher temperature.At 1423-1623 K,the oxidation of SiAlON powders is diffusion controlled and it can be described by Chou's model.A fair agreement is found between theoretical calculations and the experimental data.
文摘It was shown by TEM and X-ray analysis that there are four types of grains of the main Ni3Al phase in the structure of the intermetallic obtained by the self-propagation high temperature method (SHS). Every type of grains has its own domain and dislocation structure. There are mono- and polydomains with and without dislocations. The grains of the main phase of monoand polydomains without dislocations and polydomains with dislocations were formed by diffusion in the solid phase. In these conditions NiAl3 phase is located on the grain boundary of the main phase. The Ni2Al3 phase is located at the triple joints of the main phase.
文摘The Ni_3B phase was formed when boron (0.5 at. pct B) was added to the intermetallic of sto- ichiometric and off-stoichiometric (Ni-24 at. pct Al) compounds. In the alloy of stoichiometric composition the particles of Ni_3B phase has the size around 0.1μm and is located on the grain boundary of the main phase. The decreasing of concentrations of Al in the ofF-stoichiometric alloy leads to increase in the degree of the long-range order parameter, increasing the concen- trations of boron in the solid solution and decreasing its localization on the grain boundary. Microalloying of boron leads to increasing in the fraction of grain monodomains with disloca- tions up to 0.7 in the alloy of the off-stoichiometric composition and up to 1 in the alloy of the stoichiometric composition. It was established the correlation between the degree of the concentration inhomogeneity, average density of the dislocations and the average long range-order parameter.
基金Fund by International Centre for diffraction Data.
文摘A new compound Ba6Ti7Nb9O42 was prepared for the first time by solid state reaction in BaO-TiO2-Nb2O5, ternary system. The X-ray powder diffraction data of the title compound was determined. Ba6Ti7Nb9O42 crystallizes in the hexagonal system -with unit cell parameters a=9.0527(4) A,c=11.790(1) A,and space group P63/mcm(193),z=1. The calculated and measured densities are 5. 293 g/cm3 and 5.285 g/cm3, respectively.
基金financially supported by Chongqing Undergraduate Training Programs for Innovation and Entrepreneurship (S201910635126)approved by the Natural Science Foundation of Chongqing Province-Level Municipality,China (cstc2018jcyjAX0527)。
文摘According to the proportion of 1:1, konjac flour and mulberry leaf powder are compounded into a kind of dietary fiber source(KMCP). It is found to be good for anti-inflammation. However, its precise anti-allergic rhinitis effect and mechanism remain unknown. In our work, the effect of KMCP on allergic rhinitis(AR)induced by ovalbumin(OVA)was investigated. We found that the number of nasal rubbing and sneezing, the eosinophil(EOS)count in the nasal mucosa, and the serum levels of histamine(HIS), OVA-specific immunoglobulin E(OVA-sIgE)and interleukin-4(IL-4)were decreased, and the histopathological changes of nasal mucosa were inhibited. Additionally, the experiments further proved that the KMCP treatment could exert substantial effects on short-chain fatty acids(SCFAs)metabolism in the cecum as well. Overall findings suggest that KMCP could suppress the inflammatory response in AR mice, and serve as a novel curative therapeutic for AR without side effects.
基金Jiangsu Province Natural Science Foundation Item(BK20161606)Special Fund for Improving Academic Ability of Nursing of Integrated Traditional Chinese and Western Medicine(TG20180003d)
文摘Chronic refractory w ounds are common and frequently-seen diseases in surgery.Due to their long course of disease and complex pathogeneses,chronic refractory w ounds arouse high attention in clinic.With the preliminary results of clinical research of their pathogeneses and new treatments achieved,traditional Chinese medicine(TCM),w ith its unique concept,breaks the limitation commonly existing in the methods of w estern medicine,especially obtaining certain achievements in chronic refractory w ounds.This paper review ed the therapeutic effects of compound Baiyu pow der in the treatment of chronic refractory w ounds to prove to be effective,convenient to use and save medical costs.
基金Funded by Joint Funds of the National Natural Science Foundation of China(No.U1904188)Jiangxi Provincial Department of Education Science and Technology Project(Nos.GJJ171079,GJJ181023 and GJJ181022)。
文摘Carbonated recycled powder as cementitious auxiliary material can reduce carbon emissions and realize high-quality recycling of recycled concrete.In this paper,microscopic property of recycled powder with three carbonation methods was tested through XRD and SEM,the mechanical property and microstructure of recycled powder mortar with three replacement rates were studied by ISO method and SEM,and the strengthening mechanism was analyzed.The results showed that the mechanical property of recycled powder mortar decreased with the increasing of replacement rate.It is suggested that the replacement rate of recycled powder should not exceed 20%.The strength index and activity index of carbonated recycled powder mortar were improved,in which the flexural strength was increased by 27.85%and compressive strength was increased by 20%at the maximum.Recycled powder can be quickly and completely carbonated,and the improvement effect of CH pre-soaking carbonation was the best.The activity index of carbonated recycled powder can meet the requirements of Grade II technical standard for recycled powder.Microscopic results revealed the activation mechanism of carbonated recycled powder such as surplus calcium source effect,alkaline polycondensation effect and carbonation enhancement effect.
基金supported by National Natural Science Foundation of China (Grant No. 50864002)Guangxi Provincial Natural Science Foundation of China (Grant No. 0991001)
文摘The Al-Si-Mg alloy which can be strengthened by heat treatment is widely applied to the key components of aerospace and aeronautics. Iron-rich intermetallic compounds are well known to be strongly influential on mechanical properties in Al-Si-Mg alloys. But intermetallic compounds in cast Al-Si-Mg alloy intermetallics are often misidentified in previous metallurgical studies. It was described as many different compounds, such as AlFeSi, Al8Fe2Si, Al5(Fe, Mn)3Si2 and so on. For the purpose of solving this problem, the intermetallic compounds in cast Al-Si alloys containing 0.5% Mg were investigated in this study. The iron-rich compounds in Al-Si-Mg casting alloys were characterized by optical microscope(OM), scanning electron microscope(SEM), energy dispersive X-ray spectrometer(EDS), electron backscatter diffraction(EBSD) and X-ray powder diffraction(XRD). The electron backscatter diffraction patterns were used to assess the crystallographic characteristics of intermetallic compounds. The compound which contains Fe/Mg-rich particles with coarse morphologies was Al8FeMg3Si6 in the alloy by using EBSD. The compound belongs to hexagonal system, space group P6_2m, with the lattice parameter a=0.662 nm, c=0.792 nm. The β-phase is indexed as tetragonal Al3FeSi2, space group I4/mcm, a=0.607 nm and c=0.950 nm. The XRD data indicate that Al8FeMg3Si6 and Al3FeSi2 are present in the microstructure of Al-7Si-Mg alloy, which confirms the identification result of EBSD. The present study identified the iron-rich compound in Al-Si-Mg alloy, which provides a reliable method to identify the intermetallic compounds in short time in Al-Si-Mg alloy. Study results are helpful for identification of complex compounds in alloys.
文摘In this study, rat models of Parkinson's disease induced by substantia nigra injection of 6-hydroxy-dopamine were intragastrically administered Zhichan powder daily for 50 days. Reverse transcription PCR results showed that tyrosine hydroxylase mRNA expression in the rat substantia nigra was significantly increased, while monoamine oxidase B mRNA expression was significantly decreased in the Zhichan powder group, compared with the model group. In addition, the levels of striatal dopamine and homovanillic acid, the ratio of dopamine to homovanillic acid, and the activity of blood superoxide dismutase were all higher in the Zhichan powder group than in the model group but the content of malondialdehyde in blood was lower. Our experimental findings indicate that Zhichan powder has an antioxidant effect, it can regulate the expression of monoamine oxidase B and tyrosine hydroxylase in the substantia nigra of Parkinson's disease rats, and it can facilitate the secretion of striatal dopamine and its metabolite homovanillic acid.
文摘The production of Y2O3-ZrO2 powder by the reaction of zirconium salt and yttrium salt, combined in a certain proportion, with sodium nitrate under molten state was described. The effects of adding Cl-, Br- and CO2-3 anions, as well as introducing ultrasonic vibration during the reaction on the crystallite size of Y2O3-Zr2O3 powder were investigated.
基金Project(5JJ3010) supported by the Natural Science Foundation of Hunan Province, China
文摘Ultrafine alumina power was obtained by calcining the precursor at 1 200 ℃ for 2 h, which was prepared by homogeneous precipitation method using aluminium salts and urea as raw materials. The effects of anions on the morphology, particle size, surface area and configuration of the precursors were studied. The results show that the reactions of urea with aluminium nitrate and aluminium chloride result in agglomerates gels with bad filtering performance, the morphology is fibrillar. Aluminium sulphate-urea reactions result in the direct formation of amorphous powders with good filtering performance, of which morphology are regular spherical particles with larger granularity and smaller surface area. The reaction of mutual compound of aluminium sulphate and aluminium nitrate with molar ratio of 40:60 with urea can produce precursor with good filtering performance, spherical morphology, and uniform granularity distribution in the particle size range of 2-3 μm.
基金Project supported by the National Natural Science Foundation of China (20163002)and the Jianxi Natural Science Foundation( 0220004 )
文摘To satisfy practical requirements from industrial applications, an alternate route for synthesis compound ultrafine CeO2 powders by wet-solid-phase mechanochemical modification using industrial grade hydrated cerium carbonate as raw material was proposed.The effect of modifier reaction percentage, reaction time, calcining temperature and modifier amount on particle size, density, suspensibility, and hardness of compound CeO2 powder was investigated.The phase evolutions of preparation process were characterized by XRD.SEM micrograph of the final product shows that compound CeO2 powders obtained are well-dispersed, spherically-shaped, uniformly-sized and submicron-sized particles.The method is readily available in raw material, low in cost, simple in process, and has great potential for industrialization.The compound CeO2 powders of different physical properties can be synthesized by controlling the above-mentioned influence factors in preparation process.
基金Jiangsu TCM Bureau Project(YB2015043)Jiangsu Science and Technology Department Project(BK20161606).
文摘Objective:To assess the efficacy of compound Bai Yu San(CBYS)as a new treatment option,in healing diabetic skin ulcer.Materials and Methods:A total of 64 diabetic patients with skin ulcer were enrolled and randomly assigned to experimental group(n=33)and control group(n=31).In the control group,normal saline(NS)was used to cleanse the wound.After debridement,the wound was dressed with modern materials.In the experimental group,the NS‑cleansed wound was dressed with CBYS.The infection rate,healing rate,treatment cost,and patient satisfaction between the two groups were compared.Results:On the 35th day after treatment,the infection rate and healing rate showed no between‑group difference(P>0.05);the experimental group showed lower treatment cost and higher satisfaction than the control group(P<0.05).Conclusion:As a new treatment option for diabetes‑induced skin ulcer,CBYS can effectively control the infection,promote the healing,reduce treatment cost,and increase patient satisfaction.Dressing with CBYS can be clinically replicated in the treatment of diabetic skin ulcer.
文摘The mixture of Fe and Al powder was mechanically activated and sintered to study a non-melting methodof producing the intermetallics Fe3Al. High-energy ball milling was used as an activation method, X-ray diffractionand SEM were chosen to analyze the materials variation before and after activation and sintering, and hot press ofFe-Al powder was inveshgated to compare mechanical activation with sintering. The results show that combiningmechanical activation with reaction sintering can complete the transformation from pure Fe and Al powder to intermetallics. It is difficult to do the transformation by either mechanical activation or hot press.