[Objectives]This study was conducted to explore the dynamic changes of volatile flavor compounds in prepared pork during storage at different low-temperature conditions.[Methods]Prepared pork was stored at 4,-4 and-18...[Objectives]This study was conducted to explore the dynamic changes of volatile flavor compounds in prepared pork during storage at different low-temperature conditions.[Methods]Prepared pork was stored at 4,-4 and-18℃.The volatile flavor compounds of prepared pork were determined by solid-phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS)at days 0,7,14,21 and 28,and relative odor activity value(OAV),principal component analysis(PCA)and cluster analysis(CA)were combined to analyze changes in volatile flavor compounds of prepared pork during storage.[Results]The total number of volatile flavor compounds gradually decreased with the prolongation of the storage period,and OAV analysis identified 22 key flavor compounds(OAV≥1).The results of PCA and CA showed that 2-methyl-1-butanol,1-octen-3-ol,linalool,cineole,hexanal and nonanal were the main key flavor components,and the degree of flavor degradation was low under both superchilling and freezing conditions.After 28 days of storage,the alcohol content in the chilling group was significantly higher than other two groups,and the overall content of volatile flavor compounds was also significantly higher than other two groups,indicating that the-4℃chilling storage was more favorable for maintaining the overall flavor of prepared pork.[Conclusions]This study provides a theoretical basis for finding a better storage method for prepared meat products.展开更多
With the accelerated pace of life and the demand for dietary diversification,more and more people begin to pay attention to the convenience and health of diet,and the prepared dishes market is getting more and more at...With the accelerated pace of life and the demand for dietary diversification,more and more people begin to pay attention to the convenience and health of diet,and the prepared dishes market is getting more and more attention and favor because of its characteristics of convenient and quick.In order to understand the acceptance of college students' to the prepared dishes market,this paper aimed to collect college students' views and suggestions on the prepared dishes market by means of a questionnaire survey.By analyzing the results of the survey,we found that college students' generally have a positive attitude towards prepared dishes markets,and they believe that prepared dishes provides convenient,fast and diversified dietary choices.However,some college students' have some concerns about the quality and food safety of the prepared dishes market,such as adding too many food additives and preservatives.Through the research on college students' acceptance of the prepared dishes market,we can reveal the demand and potential problems of college students' for the prepared dishes market from the consumer s point of view,so as to provide a reference for the future development of the prepared dishes market.展开更多
Influenza is one of the oldest infectious diseases affecting humans. Every influenza pandemic in history has ended with disastrous outcomes regarding public health and the social economy. This year marks the 100th ann...Influenza is one of the oldest infectious diseases affecting humans. Every influenza pandemic in history has ended with disastrous outcomes regarding public health and the social economy. This year marks the 100th anniversary of the Spanish flu (H1N1) outbreak of 1918, which is recognized as the most lethal natural event in recent history.展开更多
Sulfated zirconia-lanthana （SO4^2-/ZrO2-La2O3） precursors were prepared by ultrasonic coprecipitation method and followed by aging at different temperature. The precursors were treated by 0.5 mol/L H2SO4. Samples of...Sulfated zirconia-lanthana （SO4^2-/ZrO2-La2O3） precursors were prepared by ultrasonic coprecipitation method and followed by aging at different temperature. The precursors were treated by 0.5 mol/L H2SO4. Samples of SO4^2-/ZrO2-La2O3 nano-crystalline catalysts were obtained by baking the treated precursors at different temperatures. The acidic properties of SO4^2-/ZrO2-La2O3 were tested by the Hammett indicator method. The phase composition, specific area, particle structure, and surface state were characterized by X-ray diffraction, BET, transmission electron microscopy, infrared spectrum, and X-ray photoelectron spec- troscopy. The catalytic activities were estimated by esterification of acetic acid with glycerin. It was shown that the catalyst prepared by ultrasonic stirring and low temperature （-15 ℃） exhibited highly active sites and high catalytic property.展开更多
OBJECTIVE: To assess the efficacy and safety in 105 patients with seasonal Influenza in Beijing, the mixture prepared with Chinese medicines follows the treatment regimen of releasing exterior cold andclearing interio...OBJECTIVE: To assess the efficacy and safety in 105 patients with seasonal Influenza in Beijing, the mixture prepared with Chinese medicines follows the treatment regimen of releasing exterior cold andclearing interior heat.METHODS: Total 330 patients with seasonal influenza were enrolled and randomly and averagely divided into the Chinese herbal medicine, the western medicine and the Chinese patent medicine group. They were treated with Chinese medicine Oseltamivir Phosphate Capsules and the Scattering Wind and Resolving Toxins Capsules. The main efficacy indicators were the antifebrile onset time and recovery time of body temperature. The efficacy and safety of the mixture was scientifically evaluated. Comparisons of several variables were analyzed.RESULTS: Median antifebrile onset time of the Chinese herbal medicine group was significantly shorter than the western medicine group(P < 0.05) and the Chinese patent medicine group(P < 0.05). The median antifebrile recovery time of the Chinese herbal medicine group was significantly shorter than the Chinese patent medicine group(P <0.05). The groups evaluated by TCM symptom pattern effect, both the Chinese herbal medicine group and Western Medicine group were better than the Chinese patent medicine group(P <0.05). The disappearance rate of main symptoms and some minor symptom patterns of the Chinese herbal medicine group were higher than the other 2 groups.CONCLUSION: The mixture of releasing exterior cold and clearing interior heat could significantly shorten the fever time with safety.展开更多
A fibrous sorbent possessing abundant micropore structure was firstly prepared via post-crosslinking reaction on the PP-ST-DVB original fiber. Its micromorphology and sorptive properties were investigated, and the res...A fibrous sorbent possessing abundant micropore structure was firstly prepared via post-crosslinking reaction on the PP-ST-DVB original fiber. Its micromorphology and sorptive properties were investigated, and the results demonstrated that the novel fibrous hypererosslinked sorbent has narrow pore-size distribution, small average porous radius （1.90 nm）, high specific surface area （362.31 m^2/g）, and fine sorptive properties for small organic molecules.展开更多
Na-W-Mn-Zr-S-P/SiO2 catalysts for oxidative coupling of methane （OCM） were prepared by incipient wetness impregnation, sol-gel and mixture slurry methods. The catalyst prepared by mixture slurry method showed the be...Na-W-Mn-Zr-S-P/SiO2 catalysts for oxidative coupling of methane （OCM） were prepared by incipient wetness impregnation, sol-gel and mixture slurry methods. The catalyst prepared by mixture slurry method showed the best catalytic performance among all samples. In addition, the effects of different addition sequences of Na, W, Mn, Zr, S and P on the catalytic performance were studied. The absence of Na before the addition of Mn and Zr in the catalysts preparation depressed the formation of the active phases of Mn2O3 and ZrO2 and decreased the activities of the catalysts significantly.展开更多
Rapidly solidified 2024 aluminium alloy powders were mechanically milled, then consolidated to bulk form. The microstructural changes of the powders in mechanical milling (MM) and consolidation process were characteri...Rapidly solidified 2024 aluminium alloy powders were mechanically milled, then consolidated to bulk form. The microstructural changes of the powders in mechanical milling (MM) and consolidation process were characterized by X-ray diffraction analyses and transmission electron microscopy observations. The results showed that mechanical milling reduced the grain size to nanometer, dissolved the Al2Cu intermetallic compound into the aluminium matrix and produced an aluminium supersaturated solid solution. During consolidation process. the grain size increased to submicrometer, and the Al2Cu and Al2(Cu, Mg, Si, Fe, Mn) compounds precipitated owing to heating. Increasing consolidation temperature and time results in obvious grain growth and coarsening of second phase particles. The tensile yield strength of the consolidated alloy with submicrometer size grains increases with decreasing grain size, and it follows the famous HallPetch relation展开更多
Ti1Al2O3 Functionally Gradient Material (FGM) was prepared by an explosive compaction/SHS process. Ten sheets of the compounding powder were laminated and pressed to get a green body of FGM. It was then compacted expl...Ti1Al2O3 Functionally Gradient Material (FGM) was prepared by an explosive compaction/SHS process. Ten sheets of the compounding powder were laminated and pressed to get a green body of FGM. It was then compacted explosively By burying the explosive compaction body into a stoichiometric Al/TiO2 mixture and igniting the combustion of the stoichiometric Al/TiO2 mixture, the SHS reaction of the explosive compaction body was initiated by the heat released from the combustion of the stoichiometric Al/TiO2 mixture. In this way, Ti/Al2O3 FGM was synthesized. The adiabatic temperatures of each gradient layer were calculated when the preheating temperatures were 298 K and 1173 K, respectively The microstructure, composition and properties of Ti/Al2O3 FGM and the reaction mechanism of each gradient layer were studied. It was found that Ti/Al2O3 FGM prepared by the explosive compaction/SHS process had a high density and a high microhardness. Its structure, composition and properties showed apparent gradient distribution. The structure of the standard stoichiometric ratio gradient layer of FGM was a network structure. Its reaction mode could be described as follows: Al powder melted first, then the molten Al penetrated into the TiO2 zone and reacted with TiO2, and big pores were left in the original positions of Al powder. The reaction of gradient layers with the addition of Al3O3 as diluents was similar to that of the standard stoichiometric ratio gradient layer, so were their structure and composition. However, the reaction of gradient layers with the addition of Ti as diluents was more complex and the composition deviated slightly from the designed one展开更多
Objective: To investigate the effect of prepared rhubarb on insulin resistance in patients with pregnancy induced hypertension (PIH) and its mechanism. Methods: All the 92 patients accepted 75 g oral glucose tolerance...Objective: To investigate the effect of prepared rhubarb on insulin resistance in patients with pregnancy induced hypertension (PIH) and its mechanism. Methods: All the 92 patients accepted 75 g oral glucose tolerance test (OGTT) and insulin release test before and after treatment. These patients were divided into two groups (treated group and control group). Prepared rhubarb and nifedipine were given to the treated group, while nifedipine was given to the control group alone. Circulating endothelial cell (CEC), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) were measured and glucose area under curve (GAUC), insulin area under curve (IAUC), insulin sensitivity index (ISI) were calculated. And 30 normal pregnant women were selected as the healthy group. Results: CEC, TNF-a, IL-6, GAUC and IAUC of PIH patients were significantly higher than those of the normal healthy group; while ISI of PIH patients was significantly lower than that of the healthy group. ISI was significantly negatively correlated to CEC, TNF-a and IL-6. After treatment, CEC, TNF-α, IL-6, GAUC decreased and ISI increased significantly in the treated group; while in the control group, all above-mentioned parameters showed no change. Conclusion: Prepared rhubarb can improve insulin resistance of PIH by reducing vascular endothelial cell's damage.展开更多
The rapid development of next-generation flexible electronics stimulates the growing demand for flexible and wearable power sources with high energy density.Li metal capacitor(LMC),combining with a Li metal anode and ...The rapid development of next-generation flexible electronics stimulates the growing demand for flexible and wearable power sources with high energy density.Li metal capacitor(LMC),combining with a Li metal anode and an activated carbon cathode,exhibits extremely high energy density and high power density due to the unique energy storage mechanism,thus showing great potential for powering wearable electronic devices.Herein,a flexible LMC based on an in situ prepared PETEA-based gel polymer electrolyte(GPE)was reported for the first time.Owing to the high ionic conductivity of PETEA-based GPE(5.75×10^(−3)S/cm at 20℃),the assembled flexible LMC delivers a high capacitance of 210 F/g at 0.1 A/g within the voltage range from 1.5 V to 4.3 V vs.Li/Li^(+),a high energy density of 474 Wh/kg at 0.1 A/g and a high power density of 29 kW/kg at 10 A/g.More importantly,PETEA-based GPE endows the LMC with excellent flexibility and safety,which could work normally under abuse tests,such as bending,nail penetration and cutting.The in situ prepared PETEA-based GPE simplifies the fabrication process,avoids the risk of leakage and inhibits the growth of Li dendrite,making LMC a promising flexible energy storage device for the flexible electronic field.展开更多
Nanocrystalline CeO2 powders (particle size ≈10-15 nm), doped with up to 20 at.-% of Mg,Ca or Y were prepared by chemical precipitation under hydrothermal conditions. The particle size and shape of the powders change...Nanocrystalline CeO2 powders (particle size ≈10-15 nm), doped with up to 20 at.-% of Mg,Ca or Y were prepared by chemical precipitation under hydrothermal conditions. The particle size and shape of the powders change slightly with the dopant concentrations. The the of the dopants on the sintering of the compacted powders was investigated during heating at a constant rate of 10℃/min. The elemental composition and the concentration of the dopant has significant efFect on the densification and grain growth. Compared to undoped CeO2, the dopants produce a shift in the densification curve to higher temperatures. For the same dopant concentration and under identical sintering conditions, the Ca doped samples reach nearly full density with the smallest grain size (≈50 nm), however, the Mg doped sample has the lowest density (≈95% of the theoretical) with the largest grain size (≈1 μm)展开更多
Nitrogen oxides(NO_2 and NO)are absorbed by tributyl phosphorate(TBP)to fom a new complex mixture of TBP-NO_x. which is used as a selective oddizing agent to oxidize benzylalcohols to corresponding sldehydes or ketone...Nitrogen oxides(NO_2 and NO)are absorbed by tributyl phosphorate(TBP)to fom a new complex mixture of TBP-NO_x. which is used as a selective oddizing agent to oxidize benzylalcohols to corresponding sldehydes or ketones In high yield. In the reaction process, nitrogen oxides are llberated mildly and mainly reduced to nitrogen, while tributyl phosphorate is recovered end recycled.展开更多
Tb0.3Dy0.TFe1.95 alloys are solidified under various high magnetic field conditions. The influence of a high magnetic field on the crystal orientation, morphology and magnetostriction of the alloys are studied. The re...Tb0.3Dy0.TFe1.95 alloys are solidified under various high magnetic field conditions. The influence of a high magnetic field on the crystal orientation, morphology and magnetostriction of the alloys are studied. The results show that with the increase of magnetic flux density, the crystal orientation of the （Tb,Dy）Fe2 phase changed from （113） to （111） direction; the grains in the alloys tended to align along the magnetic field direction; and the magnetostriction of Tb0.3Dy0.7Fe1.95 alloys is remarkably improved. The change in magnetostriction of Tb0.3Dy0.TFe1.95 alloys is linked to the amount and the crystal orientation behavior of the （Tb,Dy）Fe2 phase.展开更多
The comparative study of the tensile plastic deformation of nano(n)-TiO2 ceramic prepared byphysical gas condensation (P) and chemical hydrolysis precipitation (C) methods was conductedby a gas pressure forming techni...The comparative study of the tensile plastic deformation of nano(n)-TiO2 ceramic prepared byphysical gas condensation (P) and chemical hydrolysis precipitation (C) methods was conductedby a gas pressure forming technique at 750~800℃. The results show that n-TiO2 (P) possessesexcellent property of tensile pIastic deformation comparing with n-TiO2(C). The reason for thisis attributed to the surface cleanness and soft agglomeration of n-TiO2 (P) particfe prepared inreIatively cIean vacuum condition.展开更多
Reaction-milled NiAl-TiB2 composite was fabricated by mechanical alloying elemental powders and hot pressing. TiB2 particles are distributed mostly in grain boundaries of the matrix. The compressive strain to failure ...Reaction-milled NiAl-TiB2 composite was fabricated by mechanical alloying elemental powders and hot pressing. TiB2 particles are distributed mostly in grain boundaries of the matrix. The compressive strain to failure of the composite at RT is about twice that of cast NiAl. The compressive yield stress at high temperatures is about 4.5 times higher than that of extruded NiAl, and is also much stronger than XD NiAl-TiB2 composites. Deformation behavior between 1000~1100℃ with different strain rates has been investigated展开更多
The structure and magnetic properties of SmyFe100-1.5yC0.5y(y=8～20) alloys prepared by mechanical alloying (MA) from Sm, Fe and graphite have been investigated systematically. In order to improve hard magnetic proper...The structure and magnetic properties of SmyFe100-1.5yC0.5y(y=8～20) alloys prepared by mechanical alloying (MA) from Sm, Fe and graphite have been investigated systematically. In order to improve hard magnetic properties of the alloys prepared by mechanical alloying, a new method consisting of re-milling and re-annealing was developed. After being re-milled and re-annealed, the Curie temperature TC of the Sm-Fe-C alloys changes. The TC of 2:17 phase increases, whereas the TC of 2:14:1 phase decreases. After being re-annealed at low temperatures, the grain sizes of hard phases are smaller than those in the alloys annealed at high temperatures. The effects of Co or Ti substitution for Fe are studied.展开更多
FeTi_1-O_2（= 0.00,0.05,0.10） nanocomposites are synthesized using a sol-gel method involving an ethanol solvent in the presence of ethylene glycol as the stabilizer,and acetic acid as the chemical reagent.Their stru...FeTi_1-O_2（= 0.00,0.05,0.10） nanocomposites are synthesized using a sol-gel method involving an ethanol solvent in the presence of ethylene glycol as the stabilizer,and acetic acid as the chemical reagent.Their structural and optical analyses are studied to reveal their physicochemical properties.Using the x-ray diffractometer（XRD）analysis,the size of the nanoparticles（NPs） is found to be 18-32 nm,where the size of the NPs decreases down to 18 nm when Fe impurity of up to 10% is added,whereas their structure remains unchanged.The results also indicate that the structure of the NPs is tetragonal in the anatase phase.The Fourier transform infrared spectroscopy analysis suggests the presence of a vibration bond（Ti-O） in the sample.The photoluminescence analysis indicates that the diffusion of Fe^（3＋） ions into the TiO_2 matrix results in a decreasing electron-hole recombination,and increases the photocatalytic properties,where the best efficiency appears at an impurity of10%.The UV-diffuse reflection spectroscopy analysis indicates that with the elevation of iron impurity,the band gap value decreases from 3.47 eV for the pure sample to 2.95 eV for the 10 mol% Fe-doped TiO_2 NPs.展开更多
Hydrogenated silicon carbide films (SiC:H) were deposited using the electron cyclotron resonance chemical vapour deposition (ECR-CVD) technique from a mixture of methane, silane and hydrogen, and using diborane and ph...Hydrogenated silicon carbide films (SiC:H) were deposited using the electron cyclotron resonance chemical vapour deposition (ECR-CVD) technique from a mixture of methane, silane and hydrogen, and using diborane and phosphine as doping gases. The effects of changes in the microwave power on the deposition rate and optical bandgap were investigated, and variations in the photoand dark-conductivities and activation energy were studied in conjunction with film analysis using the Raman scattering technique. In the case of boron-doped samples, the conductivity increased rapidly to a maximum, followed by rapid reduction at high microwave power. The ratio of the photo- to dark-conductivity (σph/σd) peaked at microwave power of ~600 W. Under conditions of high microwave power, Raman scattering analysis showed evidence of the formation and increase in the silicon microcrystalline and diamond-like phases in the films, the former of which could account for the rapid increase and the latter the subsequent decrease in the conductivity.In the case of phosphorusdoped SiC:H samples, it was found that increase in the microwave power has the effect of enhancing the formation of the silicon microcrystalline phase in the films which occurred in correspondence to a rapid increase in the conductivity and reduction in the activation energy The conductivity increase stabilised in samples deposited at microwave power exceeding 500 W probably as a result of dopant saturation. Results from Raman scattering measurements also showed that phosphorus doping had the effect of enhancing the formation of the silicon microcrystals in the film whereas the presence of boron had the effect of preserving the amorphous structure.展开更多
The metal vapor synthesis (MVS) methed was used to prepare activatedcarbon supported nickel electrode. The electrocatalytic activity of the electrode forhydrogen evolution reaction(HGR) in alkaline solution was studie...The metal vapor synthesis (MVS) methed was used to prepare activatedcarbon supported nickel electrode. The electrocatalytic activity of the electrode forhydrogen evolution reaction(HGR) in alkaline solution was studied. Cathodicpolarization curves showed the electrocatalytic activity of Ni/C electrode prepared byMVS method was higher than that of the one prepared by conventional method.展开更多
基金Supported by Science and Technology Achievement Transformation Program of Sichuan Province(2023ZHCG0079)Research and Application of Key Techniques for Industrialization of Frozen Prepared Meat Dishes(GCZX22-35)Sichuan Pig Innovation Team of National Agricultural Industry Technology System(scsztd-2024-08-07).
文摘[Objectives]This study was conducted to explore the dynamic changes of volatile flavor compounds in prepared pork during storage at different low-temperature conditions.[Methods]Prepared pork was stored at 4,-4 and-18℃.The volatile flavor compounds of prepared pork were determined by solid-phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS)at days 0,7,14,21 and 28,and relative odor activity value(OAV),principal component analysis(PCA)and cluster analysis(CA)were combined to analyze changes in volatile flavor compounds of prepared pork during storage.[Results]The total number of volatile flavor compounds gradually decreased with the prolongation of the storage period,and OAV analysis identified 22 key flavor compounds(OAV≥1).The results of PCA and CA showed that 2-methyl-1-butanol,1-octen-3-ol,linalool,cineole,hexanal and nonanal were the main key flavor components,and the degree of flavor degradation was low under both superchilling and freezing conditions.After 28 days of storage,the alcohol content in the chilling group was significantly higher than other two groups,and the overall content of volatile flavor compounds was also significantly higher than other two groups,indicating that the-4℃chilling storage was more favorable for maintaining the overall flavor of prepared pork.[Conclusions]This study provides a theoretical basis for finding a better storage method for prepared meat products.
基金Supported by Sichuan Science and Technology Program(2023YFN0056)A Ba Science and Technology Program(R23CGZH0004)Open Fund Project of Key Laboratory of Meat Processing of Sichuan Province(21-R-42).
文摘With the accelerated pace of life and the demand for dietary diversification,more and more people begin to pay attention to the convenience and health of diet,and the prepared dishes market is getting more and more attention and favor because of its characteristics of convenient and quick.In order to understand the acceptance of college students' to the prepared dishes market,this paper aimed to collect college students' views and suggestions on the prepared dishes market by means of a questionnaire survey.By analyzing the results of the survey,we found that college students' generally have a positive attitude towards prepared dishes markets,and they believe that prepared dishes provides convenient,fast and diversified dietary choices.However,some college students' have some concerns about the quality and food safety of the prepared dishes market,such as adding too many food additives and preservatives.Through the research on college students' acceptance of the prepared dishes market,we can reveal the demand and potential problems of college students' for the prepared dishes market from the consumer s point of view,so as to provide a reference for the future development of the prepared dishes market.
基金supported by the National Key Research and Development Program of China (grant 2017YFC1200202)the Major Special Projects for Infectious Disease Research of China (grant 2016ZX10004222003)+1 种基金the National Natural Science Foundation of China (grants 81401312 and 81373141)supported by the Excellent Young Scientist Program of the NSFC (81822040)
文摘Influenza is one of the oldest infectious diseases affecting humans. Every influenza pandemic in history has ended with disastrous outcomes regarding public health and the social economy. This year marks the 100th anniversary of the Spanish flu (H1N1) outbreak of 1918, which is recognized as the most lethal natural event in recent history.
文摘Sulfated zirconia-lanthana （SO4^2-/ZrO2-La2O3） precursors were prepared by ultrasonic coprecipitation method and followed by aging at different temperature. The precursors were treated by 0.5 mol/L H2SO4. Samples of SO4^2-/ZrO2-La2O3 nano-crystalline catalysts were obtained by baking the treated precursors at different temperatures. The acidic properties of SO4^2-/ZrO2-La2O3 were tested by the Hammett indicator method. The phase composition, specific area, particle structure, and surface state were characterized by X-ray diffraction, BET, transmission electron microscopy, infrared spectrum, and X-ray photoelectron spec- troscopy. The catalytic activities were estimated by esterification of acetic acid with glycerin. It was shown that the catalyst prepared by ultrasonic stirring and low temperature （-15 ℃） exhibited highly active sites and high catalytic property.
基金Supported by National Science and Technology Support Program:Research on unique treatment and principle of inheritance famous old traditional Chinese doctors(No.2013BAI13B021)The Beijing municipal administration of traditional Chinese medicine inheriting program:workstation of famous doctor Zhou Ping-an construction projectThe Innovative Team Project of Beijing University of Chinese Medicine(No.2011-CXTD-08)
文摘OBJECTIVE: To assess the efficacy and safety in 105 patients with seasonal Influenza in Beijing, the mixture prepared with Chinese medicines follows the treatment regimen of releasing exterior cold andclearing interior heat.METHODS: Total 330 patients with seasonal influenza were enrolled and randomly and averagely divided into the Chinese herbal medicine, the western medicine and the Chinese patent medicine group. They were treated with Chinese medicine Oseltamivir Phosphate Capsules and the Scattering Wind and Resolving Toxins Capsules. The main efficacy indicators were the antifebrile onset time and recovery time of body temperature. The efficacy and safety of the mixture was scientifically evaluated. Comparisons of several variables were analyzed.RESULTS: Median antifebrile onset time of the Chinese herbal medicine group was significantly shorter than the western medicine group(P < 0.05) and the Chinese patent medicine group(P < 0.05). The median antifebrile recovery time of the Chinese herbal medicine group was significantly shorter than the Chinese patent medicine group(P <0.05). The groups evaluated by TCM symptom pattern effect, both the Chinese herbal medicine group and Western Medicine group were better than the Chinese patent medicine group(P <0.05). The disappearance rate of main symptoms and some minor symptom patterns of the Chinese herbal medicine group were higher than the other 2 groups.CONCLUSION: The mixture of releasing exterior cold and clearing interior heat could significantly shorten the fever time with safety.
基金The authors are grateful for the support of the National Natural Science Foundation of China （No. 20574063）.
文摘A fibrous sorbent possessing abundant micropore structure was firstly prepared via post-crosslinking reaction on the PP-ST-DVB original fiber. Its micromorphology and sorptive properties were investigated, and the results demonstrated that the novel fibrous hypererosslinked sorbent has narrow pore-size distribution, small average porous radius （1.90 nm）, high specific surface area （362.31 m^2/g）, and fine sorptive properties for small organic molecules.
基金supported by the financial support from National Natural Science Foundation of China (20676116)
文摘Na-W-Mn-Zr-S-P/SiO2 catalysts for oxidative coupling of methane （OCM） were prepared by incipient wetness impregnation, sol-gel and mixture slurry methods. The catalyst prepared by mixture slurry method showed the best catalytic performance among all samples. In addition, the effects of different addition sequences of Na, W, Mn, Zr, S and P on the catalytic performance were studied. The absence of Na before the addition of Mn and Zr in the catalysts preparation depressed the formation of the active phases of Mn2O3 and ZrO2 and decreased the activities of the catalysts significantly.
文摘Rapidly solidified 2024 aluminium alloy powders were mechanically milled, then consolidated to bulk form. The microstructural changes of the powders in mechanical milling (MM) and consolidation process were characterized by X-ray diffraction analyses and transmission electron microscopy observations. The results showed that mechanical milling reduced the grain size to nanometer, dissolved the Al2Cu intermetallic compound into the aluminium matrix and produced an aluminium supersaturated solid solution. During consolidation process. the grain size increased to submicrometer, and the Al2Cu and Al2(Cu, Mg, Si, Fe, Mn) compounds precipitated owing to heating. Increasing consolidation temperature and time results in obvious grain growth and coarsening of second phase particles. The tensile yield strength of the consolidated alloy with submicrometer size grains increases with decreasing grain size, and it follows the famous HallPetch relation
文摘Ti1Al2O3 Functionally Gradient Material (FGM) was prepared by an explosive compaction/SHS process. Ten sheets of the compounding powder were laminated and pressed to get a green body of FGM. It was then compacted explosively By burying the explosive compaction body into a stoichiometric Al/TiO2 mixture and igniting the combustion of the stoichiometric Al/TiO2 mixture, the SHS reaction of the explosive compaction body was initiated by the heat released from the combustion of the stoichiometric Al/TiO2 mixture. In this way, Ti/Al2O3 FGM was synthesized. The adiabatic temperatures of each gradient layer were calculated when the preheating temperatures were 298 K and 1173 K, respectively The microstructure, composition and properties of Ti/Al2O3 FGM and the reaction mechanism of each gradient layer were studied. It was found that Ti/Al2O3 FGM prepared by the explosive compaction/SHS process had a high density and a high microhardness. Its structure, composition and properties showed apparent gradient distribution. The structure of the standard stoichiometric ratio gradient layer of FGM was a network structure. Its reaction mode could be described as follows: Al powder melted first, then the molten Al penetrated into the TiO2 zone and reacted with TiO2, and big pores were left in the original positions of Al powder. The reaction of gradient layers with the addition of Al3O3 as diluents was similar to that of the standard stoichiometric ratio gradient layer, so were their structure and composition. However, the reaction of gradient layers with the addition of Ti as diluents was more complex and the composition deviated slightly from the designed one
文摘Objective: To investigate the effect of prepared rhubarb on insulin resistance in patients with pregnancy induced hypertension (PIH) and its mechanism. Methods: All the 92 patients accepted 75 g oral glucose tolerance test (OGTT) and insulin release test before and after treatment. These patients were divided into two groups (treated group and control group). Prepared rhubarb and nifedipine were given to the treated group, while nifedipine was given to the control group alone. Circulating endothelial cell (CEC), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) were measured and glucose area under curve (GAUC), insulin area under curve (IAUC), insulin sensitivity index (ISI) were calculated. And 30 normal pregnant women were selected as the healthy group. Results: CEC, TNF-a, IL-6, GAUC and IAUC of PIH patients were significantly higher than those of the normal healthy group; while ISI of PIH patients was significantly lower than that of the healthy group. ISI was significantly negatively correlated to CEC, TNF-a and IL-6. After treatment, CEC, TNF-α, IL-6, GAUC decreased and ISI increased significantly in the treated group; while in the control group, all above-mentioned parameters showed no change. Conclusion: Prepared rhubarb can improve insulin resistance of PIH by reducing vascular endothelial cell's damage.
基金the financial support from the Natural Science Foundation of Gansu(No.20JR10RA611)the Fundamental Research Funds for the Central Universities(Nos.Lzujbky-2017-178 and lzujbky-2017-181).
文摘The rapid development of next-generation flexible electronics stimulates the growing demand for flexible and wearable power sources with high energy density.Li metal capacitor(LMC),combining with a Li metal anode and an activated carbon cathode,exhibits extremely high energy density and high power density due to the unique energy storage mechanism,thus showing great potential for powering wearable electronic devices.Herein,a flexible LMC based on an in situ prepared PETEA-based gel polymer electrolyte(GPE)was reported for the first time.Owing to the high ionic conductivity of PETEA-based GPE(5.75×10^(−3)S/cm at 20℃),the assembled flexible LMC delivers a high capacitance of 210 F/g at 0.1 A/g within the voltage range from 1.5 V to 4.3 V vs.Li/Li^(+),a high energy density of 474 Wh/kg at 0.1 A/g and a high power density of 29 kW/kg at 10 A/g.More importantly,PETEA-based GPE endows the LMC with excellent flexibility and safety,which could work normally under abuse tests,such as bending,nail penetration and cutting.The in situ prepared PETEA-based GPE simplifies the fabrication process,avoids the risk of leakage and inhibits the growth of Li dendrite,making LMC a promising flexible energy storage device for the flexible electronic field.
文摘Nanocrystalline CeO2 powders (particle size ≈10-15 nm), doped with up to 20 at.-% of Mg,Ca or Y were prepared by chemical precipitation under hydrothermal conditions. The particle size and shape of the powders change slightly with the dopant concentrations. The the of the dopants on the sintering of the compacted powders was investigated during heating at a constant rate of 10℃/min. The elemental composition and the concentration of the dopant has significant efFect on the densification and grain growth. Compared to undoped CeO2, the dopants produce a shift in the densification curve to higher temperatures. For the same dopant concentration and under identical sintering conditions, the Ca doped samples reach nearly full density with the smallest grain size (≈50 nm), however, the Mg doped sample has the lowest density (≈95% of the theoretical) with the largest grain size (≈1 μm)
文摘Nitrogen oxides(NO_2 and NO)are absorbed by tributyl phosphorate(TBP)to fom a new complex mixture of TBP-NO_x. which is used as a selective oddizing agent to oxidize benzylalcohols to corresponding sldehydes or ketones In high yield. In the reaction process, nitrogen oxides are llberated mildly and mainly reduced to nitrogen, while tributyl phosphorate is recovered end recycled.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51425401 and 51271056the Fundamental Research Funds for the Central Universities under Grant Nos N140901001 and N140902001the Doctoral Scientific Research Foundation of Liaoning Province under Grant No 20131034
文摘Tb0.3Dy0.TFe1.95 alloys are solidified under various high magnetic field conditions. The influence of a high magnetic field on the crystal orientation, morphology and magnetostriction of the alloys are studied. The results show that with the increase of magnetic flux density, the crystal orientation of the （Tb,Dy）Fe2 phase changed from （113） to （111） direction; the grains in the alloys tended to align along the magnetic field direction; and the magnetostriction of Tb0.3Dy0.7Fe1.95 alloys is remarkably improved. The change in magnetostriction of Tb0.3Dy0.TFe1.95 alloys is linked to the amount and the crystal orientation behavior of the （Tb,Dy）Fe2 phase.
文摘The comparative study of the tensile plastic deformation of nano(n)-TiO2 ceramic prepared byphysical gas condensation (P) and chemical hydrolysis precipitation (C) methods was conductedby a gas pressure forming technique at 750~800℃. The results show that n-TiO2 (P) possessesexcellent property of tensile pIastic deformation comparing with n-TiO2(C). The reason for thisis attributed to the surface cleanness and soft agglomeration of n-TiO2 (P) particfe prepared inreIatively cIean vacuum condition.
文摘Reaction-milled NiAl-TiB2 composite was fabricated by mechanical alloying elemental powders and hot pressing. TiB2 particles are distributed mostly in grain boundaries of the matrix. The compressive strain to failure of the composite at RT is about twice that of cast NiAl. The compressive yield stress at high temperatures is about 4.5 times higher than that of extruded NiAl, and is also much stronger than XD NiAl-TiB2 composites. Deformation behavior between 1000~1100℃ with different strain rates has been investigated
基金National Natural Science FOundation of China! 59725103National Natural Science FOundation of China! 59831010Sciences and
文摘The structure and magnetic properties of SmyFe100-1.5yC0.5y(y=8～20) alloys prepared by mechanical alloying (MA) from Sm, Fe and graphite have been investigated systematically. In order to improve hard magnetic properties of the alloys prepared by mechanical alloying, a new method consisting of re-milling and re-annealing was developed. After being re-milled and re-annealed, the Curie temperature TC of the Sm-Fe-C alloys changes. The TC of 2:17 phase increases, whereas the TC of 2:14:1 phase decreases. After being re-annealed at low temperatures, the grain sizes of hard phases are smaller than those in the alloys annealed at high temperatures. The effects of Co or Ti substitution for Fe are studied.
文摘FeTi_1-O_2（= 0.00,0.05,0.10） nanocomposites are synthesized using a sol-gel method involving an ethanol solvent in the presence of ethylene glycol as the stabilizer,and acetic acid as the chemical reagent.Their structural and optical analyses are studied to reveal their physicochemical properties.Using the x-ray diffractometer（XRD）analysis,the size of the nanoparticles（NPs） is found to be 18-32 nm,where the size of the NPs decreases down to 18 nm when Fe impurity of up to 10% is added,whereas their structure remains unchanged.The results also indicate that the structure of the NPs is tetragonal in the anatase phase.The Fourier transform infrared spectroscopy analysis suggests the presence of a vibration bond（Ti-O） in the sample.The photoluminescence analysis indicates that the diffusion of Fe^（3＋） ions into the TiO_2 matrix results in a decreasing electron-hole recombination,and increases the photocatalytic properties,where the best efficiency appears at an impurity of10%.The UV-diffuse reflection spectroscopy analysis indicates that with the elevation of iron impurity,the band gap value decreases from 3.47 eV for the pure sample to 2.95 eV for the 10 mol% Fe-doped TiO_2 NPs.
文摘Hydrogenated silicon carbide films (SiC:H) were deposited using the electron cyclotron resonance chemical vapour deposition (ECR-CVD) technique from a mixture of methane, silane and hydrogen, and using diborane and phosphine as doping gases. The effects of changes in the microwave power on the deposition rate and optical bandgap were investigated, and variations in the photoand dark-conductivities and activation energy were studied in conjunction with film analysis using the Raman scattering technique. In the case of boron-doped samples, the conductivity increased rapidly to a maximum, followed by rapid reduction at high microwave power. The ratio of the photo- to dark-conductivity (σph/σd) peaked at microwave power of ~600 W. Under conditions of high microwave power, Raman scattering analysis showed evidence of the formation and increase in the silicon microcrystalline and diamond-like phases in the films, the former of which could account for the rapid increase and the latter the subsequent decrease in the conductivity.In the case of phosphorusdoped SiC:H samples, it was found that increase in the microwave power has the effect of enhancing the formation of the silicon microcrystalline phase in the films which occurred in correspondence to a rapid increase in the conductivity and reduction in the activation energy The conductivity increase stabilised in samples deposited at microwave power exceeding 500 W probably as a result of dopant saturation. Results from Raman scattering measurements also showed that phosphorus doping had the effect of enhancing the formation of the silicon microcrystals in the film whereas the presence of boron had the effect of preserving the amorphous structure.
文摘The metal vapor synthesis (MVS) methed was used to prepare activatedcarbon supported nickel electrode. The electrocatalytic activity of the electrode forhydrogen evolution reaction(HGR) in alkaline solution was studied. Cathodicpolarization curves showed the electrocatalytic activity of Ni/C electrode prepared byMVS method was higher than that of the one prepared by conventional method.
