In this paper,the occurrence and development mechanism of strain on the cross-section during the wood drying is explored.Therefore,strain regularity on the cross-section of 50 mm thickness elm(Ulmus rubra)board at the...In this paper,the occurrence and development mechanism of strain on the cross-section during the wood drying is explored.Therefore,strain regularity on the cross-section of 50 mm thickness elm(Ulmus rubra)board at the temperature of 40℃and 80℃is detected via digital image correlation technology.Hence,the difference between tangential and radial strain at surface and core layers was denoted.The results showed that strain distribution in the width direction of the board is uneven.Moreover,a large drying shrinkage strain occurs at the near-core layer,while the maximum strain difference reaches 4.08%.Hence,the surface of the board is cracked along the thickness direction.The radial strain of the board is higher than the tangential strain in the early stage of drying,while these strains are reversed in the later stage of drying.The temperature is related to the difference between the tangential and radial strains of the elm board.These differences at the core layer are larger than those of the surface layer.The conducted research results provide a theoretical basis for process optimization.展开更多
Background:The protein/energy ratio is important for the production performance and utilization of available feed resources by animals.Increased protein consumption by mammals leads to elevated feed costs and increase...Background:The protein/energy ratio is important for the production performance and utilization of available feed resources by animals.Increased protein consumption by mammals leads to elevated feed costs and increased nitrogen release into the environment.This study aimed to evaluate the effects of dietary protein/energy ratio on the growth performance,carcass traits,meat quality,and plasma metabolites of pigs of different genotypes.Methods:Bama mini-pigs and Landrace pigs were randomly assigned to two dietary treatment groups(Chinese conventional diet with low protein/energy ratio or National Research Council diet with high protein/energy ratio;n = 24 per treatment) in a 2x2 factorial arrangement.Blood and muscle samples were collected at the end of the nursery,growing,and finishing phases.Results:We observed significant interactions(P< 0.05) between breed and diet for total fat percentage,intramuscular fat(IMF) content,protein content in biceps femoris(BF) muscle,and plasma urea nitrogen(UN) concentration in the nursery phase;for average daily gain(ADG),average daily feed intake(ADFI),dry matter,IMF content in psoas major(PM) muscle,and plasma total protein and albumin concentrations in the growing phase;and for drip loss and plasma UN concentration in the finishing phase.Breed influenced(P < 0.05) growth performance,carcass traits,and meat quality,but not plasma metabolites.Throughout the trial,Landrace pigs showed significantly higher(P < 0.05) ADG,ADFI,dressing percentage,lean mass rate,and loin-eye area than did Bama mini-pigs,but significantly lower(P< 0.05)feed/gain ratio,fat percentage,backfat thickness,and IMF content.Dietary protein/energy ratio influenced the pH value,chemical composition of BF and PM muscles,and plasma activities of glutamic-pyruvic transaminase and gamma-glutamyl transpeptidase,and plasma concentration of UN.Conclusions:Compared with Landrace pigs,Bama mini-pigs showed slower growth and lower carcass performance,but had better meat quality.Moreover,unlike Landrace pigs,the dietary protein/energy ratio did not affect the growth performance of Bama mini-pigs.These results suggest that,in swine production,low dietary protein/energy ratio may be useful for reducing feed costs and minimizing the adverse effects of ammonia release into the environment.展开更多
Background: To investigate the effects of dietary crude protein(CP) restriction on muscle fiber characteristics and key regulators related to protein deposition in skeletal muscle, a total of 18 growing-finishing pigs...Background: To investigate the effects of dietary crude protein(CP) restriction on muscle fiber characteristics and key regulators related to protein deposition in skeletal muscle, a total of 18 growing-finishing pigs(62.30 ± 0.88 kg)were allotted to 3 groups and fed with the recommended adequate protein(AP, 16 % CP) diet, moderately restricted protein(MP, 13 % CP) diet and low protein(LP, 10 % CP) diet, respectively. The skeletal muscle of different locations in pigs, including longissimus dorsi muscle(LDM), psoas major muscle(PMM) and biceps femoris muscle(BFM) were collected and analyzed.Results: Results showed that growing-finishing pigs fed the MP or AP diet improved(P < 0.01) the average daily gain and feed: gain ratio compared with those fed the LP diet, and the MP diet tended to increase(P = 0.09) the weight of LDM. Moreover, the ATP content and energy charge value were varied among muscle samples from different locations of pigs fed the reduced protein diets. We also observed that pigs fed the MP diet up-regulated(P < 0.05) muscular m RNA expression of all the selected key genes, except that myosin heavy chain(My HC) IIb,My HC IIx, while m RNA expression of ubiquitin ligases genes was not affected by dietary CP level. Additionally, the activation of mammalian target of rapamycin complex 1(m TORC1) pathway was stimulated(P < 0.05) in skeletal muscle of the pigs fed the MP or AP diet compared with those fed the LP diet.Conclusion: The results suggest that the pigs fed the MP diet could catch up to the growth performance and the LDM weight of the pigs fed the AP diet, and the underlying mechanism may be partly due to the alteration in energy status, modulation of muscle fiber characteristics and m TORC1 activation as well as its downstream effectors in skeletal muscle of different locations in growing-finishing pigs.展开更多
Post-combustion CO_2 capture(PCC) process faces significant challenge of high regeneration energy consumption.Biphasic absorbent is a promising alternative candidate which could significantly reduce the regeneration e...Post-combustion CO_2 capture(PCC) process faces significant challenge of high regeneration energy consumption.Biphasic absorbent is a promising alternative candidate which could significantly reduce the regeneration energy consumption because only the CO_2-concentrated phase should be regenerated. In this work, aqueous solutions of triethylenetetramine(TETA) and N,N-diethylethanolamine(DEEA) are found to be efficient biphasic absorbents of CO_2. The effects of the solvent composition, total amine concentration, and temperature on the absorption behavior, as well as the effect of temperature on the desorption behavior of TETA–DEEA–H2 O system were investigated. An aqueous solution of 1 mol·L-1 TETA and 4 mol·L-1 DEEA spontaneously separates into two liquid phases after a certain amount of CO_2 is absorbed and it shows high CO_2 absorption/desorption performance.About 99.4% of the absorbed CO_2 is found in the lower phase, which corresponds to a CO_2 absorption capacity of 3.44 mol·kg-1. The appropriate absorption and desorption temperatures are found to be 30 °C and 90 °C,respectively. The thermal analysis indicates that the heat of absorption of the 1 mol·L-1 TETA and 4 mol·L-1 DEEA solution is-84.38 kJ·(mol CO_2)-1 which is 6.92 kJ·(mol CO_2)-1 less than that of aqueous MEA. The reaction heat, sensible heat, and the vaporization heat of the TETA–DEEA–H2 O system are lower than that of the aqueous MEA, while its CO_2 capacity is higher. Thus the TETA–DEEA–H2 O system is potentially a better absorbent for the post-combustion CO_2 capture process.展开更多
An efficient catalyst SO4^2--TiO2(ST) from industrial metatitanic acid has been successfully prepared to catalyze hydrolysis of ball-milling cellulose. The results show that the highest catalytic efficiency is obtaine...An efficient catalyst SO4^2--TiO2(ST) from industrial metatitanic acid has been successfully prepared to catalyze hydrolysis of ball-milling cellulose. The results show that the highest catalytic efficiency is obtained for ST calcined at 450 ℃(ST-450) with the yield of 21.8% glucose, 13.0% 5-HMF and 4.2% furfural at 200 ℃ for30 min. The ball milling of cellulose and solid acid catalyst significantly enhances the cellulose hydrolysis. The high Lewis to Bronsted acid sites ratio for ST-450 induced by bidentate ligands between SO4^2-and TiO2 benefits high organics yield, and high total acid sites contribute to the high cellulose conversion. The large pore volume of 0.29 cm^3·g^-1 and appropriate pore size of 7.35 nm of ST-450 also contribute to the high performance. High reaction temperature over 200 ℃ exhibits negative effect on glucose and 5-HMF yield due to undesired side reactions, while furfural product is stable in the reaction system. The bidentate ligands between SO4^2-and TiO2 are considered as active acid sites for cellulose hydrolysis in water–ethanol solvents.展开更多
BACKGROUND:Previous studies have demonstrated that homocysteine is an independent risk factor for ischemic stroke,as determined by detection of apoptosis and oxygen-free radical scavengers following cerebral ischemia....BACKGROUND:Previous studies have demonstrated that homocysteine is an independent risk factor for ischemic stroke,as determined by detection of apoptosis and oxygen-free radical scavengers following cerebral ischemia.However,the mechanisms of homocysteine remain unclear.Several reports have addressed the effects of homocysteine on ischemic stroke.OBJECTIVE:To analyze the effects of homocysteine on apoptosis,intracellular superoxide dismutase(SOD) activity,and malondialdehyde content in tissue surrounding hematoma in rats with cerebral hemorrhage,and to determine the action pathway of malondialdehyde following cerebral hemorrhage.DESIGN,TIME AND SETTING:The randomized,controlled,animal experiment was performed at the Laboratory of Molecular Biology,Hospital Affiliated to Luzhou Medical College,China from April 2007 to April 2008.MATERIALS:In situ apoptosis detection kit(Roche,Mannheim,Germany),SOD detection kit and malondialdehyde detection kit(Nanjing Jiancheng Bioengineering Institute,China),and homocysteine(Sigma,St Louis,MO,USA) were used in the present study.METHODS:A total of 75 Sprague Dawley rats were equally and randomly assigned to sham surgery,model,and homocysteine groups.Autologous blood was infused into the caudate putamen of rats to establish models of cerebral hemorrhage in model and homocysteine groups.Homocysteine was injected directly into the brain through the skull at the hematoma hemisphere at 30 minutes after model induction in the homocysteine group.MAIN OUTCOME MEASURES:At 6,12,24,and 72 hours,as well as 1 week,post-surgery,neurological deficits were observed in each group.Brain water content was measured using the dry-wet weight method.Cell apoptosis in tissue surrounding the hematoma was detected utilizing terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling(TUNEL).SOD activity and malondialdehyde content in tissue surrounding the hematoma were respectively measured using the xanthine oxidase and thiobarbituric acid methods.RESULTS:Neurological function was similar between model and homocysteine groups following cerebral hemorrhage(P > 0.05).Brain water content was increased at 12 hours post-surgery,peaked at 3 days,and remained unchanged at 7 days in the model group.Brain edema was not significantly aggravated following homocysteine intervention(P > 0.05),but SOD activity significantly decreased and malondialdehyde content significantly increased(P < 0.05).The number of apoptotic cells increased in rats with cerebral hemorrhage at 12 hours(P < 0.05),and numbers peaked at 72 hours following model establishment(P < 0.05).The time of peak value was identical between model and homocysteine groups.Brain water content was negatively associated with SOD activity(rmodel group =-0.448,P < 0.05;rhomocysteine group =-0.612,P < 0.05),but was positively associated with malondialdehyde content(rmodel group = 0.542,P < 0.05;rhomocysteine group = 0.684,P < 0.05) in brain tissues surrounding the hematoma following surgery in model and homocysteine groups.CONCLUSION:Homocysteine aggravates neurological dysfunction and brain edema in rats with cerebral hemorrhage.The mechanisms of action are likely associated with production of oxygen-free radical and cellular apoptosis following cerebral hemorrhage.展开更多
Amine-based carbon dioxide(CO2)capture is still limited by high desorption energy consumption.Fixing CO2 into carbonate is a safer and more permanent method.In this work,calcium oxide(CaO)is introduced to perform chem...Amine-based carbon dioxide(CO2)capture is still limited by high desorption energy consumption.Fixing CO2 into carbonate is a safer and more permanent method.In this work,calcium oxide(CaO)is introduced to perform chemical desorption instead of thermal desorption on 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU)aqueous solution after CO2 absorption.The X-ray diffraction(XRD)patterns of solid products show the formation of calcite calcium carbonate(CaCO3),which prove the feasibility of this method.The effects of reaction temperature,reaction time and Ca2+/CO32-molar ratios on the related reactions in CO2 absorption-mineralization process and CaCO3 precipitation are discussed,and purer CaCO3 is obtained by ultrasonic treatment.The CaCO3 content can be increased to 95.8%and the CO2 desorption ratio can achieve 80%by 30 min ultrasonic dispersion treatment under the conditions(40℃,180 min,Ca2+/CO32-molar ratio=1.0).After five cycles,DBU aqueous solution shows stable CO2 absorption and mineralization ability.Fourier transform infrared spectroscopy(FT-IR)spectra of the reaction process also indicate the regeneration of the solvent.Compared with thermal desorption,this process is exothermic,almost without no additional heat.展开更多
Gas–liquid mass transfer of rotating disk reactor was studied in CO2 absorption using 1,8-diazabicyclo-[5.4.0]-undec-7-ene(DBU)-glycerol solution as solvent. Effects of the rotating disk structure and various operati...Gas–liquid mass transfer of rotating disk reactor was studied in CO2 absorption using 1,8-diazabicyclo-[5.4.0]-undec-7-ene(DBU)-glycerol solution as solvent. Effects of the rotating disk structure and various operation parameters on the CO2 absorption rate and CO2 removal efficiency were investigated. The rotating disk with optimal holes is conducive to mass transfer of CO2 and the formation of thin liquid film at the opening increases the gas–liquid contact area. With the increase of rotating speed, the liquid flow pattern on the rotating disk surface changes from thin film flow to separated streams and creates extra liquid lines attached to the rim of the disk,which leads to a very complicated change on the CO2 absorption rate and CO2 removal efficiency. The overall gas-phase mass transfer coefficient increases 138% as the rotating speed increasing from 250 to 1400 r·min^-1.Increasing temperature from 298 to 338 K can enhance the CO2 absorption rate due to lowering the viscosity of the solvent. The rate-determined step for the absorption is focused on the gas side. The rotating disk reactor can effectively enhance the absorption of CO2 with viscous DBU-glycerol solvents.展开更多
Digestion with aqua regia in a Carius tube and separation of Re with anion exchange resin is commonly employed for Re–Os dating of molybdenite and pyrite.However, the recovery of Re is extremely low when this routine...Digestion with aqua regia in a Carius tube and separation of Re with anion exchange resin is commonly employed for Re–Os dating of molybdenite and pyrite.However, the recovery of Re is extremely low when this routine anion exchange method is applied to galena,causing difficulty in Re–Os dating of galena. In this study,we investigated the mechanism of Re loss during sample preparation and tested a revised procedure for Re–Os dating of galena and sphalerite.展开更多
Biodiesel, which is a renewable and environmentally friendly fuel, has been studied widely to help remedy increasing environmental problems. One of the key processes of biodiesel production is oil extraction from oils...Biodiesel, which is a renewable and environmentally friendly fuel, has been studied widely to help remedy increasing environmental problems. One of the key processes of biodiesel production is oil extraction from oilseed materials. Switchable solvents can reversibly change from molecular to ionic solvents under atmospheric CO_2,and can be used for oil extraction. N, N-dimethylcyclohexylamine(DMCHA), a switchable solvent, was used to extract oil from Jatropha curcas L. oil seeds to produce biodiesel. The appropriate extraction conditions were:1:2 ratio of seed mass to DMCHA volume, 0.3–1 mm particle size, 200 r·min-1agitation speed, 60 min extraction time, and 30 °C extraction temperature. The extraction ratio was about 83%. This solvent extracted the oil more efficiently than hexane, and is much less volatile. By bubbling CO_2 under 1 atm and 25 °C for 5 h, the oil was separated, and DMCHA was recovered after releasing CO_2 by bubbling N_2 under 1 atm and 60 °C for 2 h. The residual solvent content in oil was about 1.7%. Selectivity of DMCHA was evaluated by detecting the protein and sugar content in oil. Using the oil with residual solvent to conduct transesterification process, the oil conversion ratio was approximately 99.5%.展开更多
The hydrogenation of dimethyl oxalate(DMO) for the producing of C2-C4 alcohols with methanol as solvent was researched at the temperature of 270 °C to 310 °C. Ethylene glycol(EG) was the main product at low ...The hydrogenation of dimethyl oxalate(DMO) for the producing of C2-C4 alcohols with methanol as solvent was researched at the temperature of 270 °C to 310 °C. Ethylene glycol(EG) was the main product at low temperature and the selectivity of which was 61.9% at 230 °C. However, EG selectivity decreased sharply with the increase of temperature while ethanol became the main liquid products with the selectivity of 43.5% at 270 °C. It can be ascribed to a thorough hydrogenation of DMO at a high temperature. In addition, the promotion of Guerbet reaction led to the production of propanol and butanol. Simultaneously, the amount of gas products including CO, CO_2 and dimethyl ether(DME) also increased, which became a competition factor in the conversion of DMO to liquid products including C2-C4 alcohols. The blank test was carried out with pure methanol as feedstock with and without Cu/SiO_2 catalyst, which revealed that methanol was involved in the formation of gas products and higher alcohols on Cu-based catalyst, and the main gas product was CO.展开更多
This paper introduces the implementation and data analysis associated with a state-wide power quality monitoring and analysis system in China. Corporation specifications on power quality monitors as well as on communi...This paper introduces the implementation and data analysis associated with a state-wide power quality monitoring and analysis system in China. Corporation specifications on power quality monitors as well as on communication protocols are formulated for data transmission. Big data platform and related technologies are utilized for data storage and computation. Compliance verification analysis and a power quality performance assessment are conducted, and a visualization tool for result presentation is finally presented.展开更多
Osmotic stress promotes somatic embryogenesis of Fraxinus mandshurica,which leads to accumulation of reactive oxygen species(ROS).The single pieces of cotyledons of F.mandshurica were used as explants to induce somati...Osmotic stress promotes somatic embryogenesis of Fraxinus mandshurica,which leads to accumulation of reactive oxygen species(ROS).The single pieces of cotyledons of F.mandshurica were used as explants to induce somatic embryogenesis in osmotic-stress medium.Furthermore,the hydrogen peroxide H_(2)O_(2) content of explanted cells was varied by adding exogenous H_(2)O_(2) or catalase solution to assess the effects of the exogenous H_(2)O_(2)on somatic embryogenesis,intracellular H_(2)O_(2)accumulation,and the relationship between signaling mediated by ROS or reactive nitrogen species.The results revealed that exogenous H_(2)O_(2)(100?300μmol L^(–1))increased the number of somatic embryos.On 60th day of exogenous H_(2)O_(2)(200μmol L^(–1))treatment,the number of somatic embryos of explants treated,which was 136.54%,was higher than the control.Moreover,exogenous H_(2)O_(2)(100μmol L^(–1))significantly increased the intracellular H_(2)O_(2)content and enhanced the activities of superoxidase dismutase and peroxidase.Finally,exogenous H_(2)O_(2)(100μmol L^(–1))activated the intracellular non-enzymatic pathway for nitric oxide(NO)synthesis.The somatic embryogenesis in broadleaf trees increases with the change of endogenic ROS content,and depends on the upregulation of antioxidant enzymes.Both H_(2)O_(2)and NO,as signaling molecules,were found to be involved in the process of somatic embryogenesis in broadleaf trees.In the process of exogenous H_(2)O_(2)promoting somatic embryogenesis,NO synthesis depended on non-enzymatic reactions.These results provide a scientific basis for resolving the mechanism by which ROS levels are regulated during somatic embryogenesis of broadleaf trees and establish a reasonable and efficient technology system for regulating somatic embryogenesis of trees.展开更多
Evolution laws of microstructures,mechanical properties,and fractographs after different solution temperatures were investigated through various analysis methods.With the increasing solution temperatures,contents of t...Evolution laws of microstructures,mechanical properties,and fractographs after different solution temperatures were investigated through various analysis methods.With the increasing solution temperatures,contents of the primaryαphase decreased,and contents of transformedβstructures increased.Lamellarαgrains dominated the characteristics of transformedβstructures,and widths of secondaryαlamellas increased monotonously.For as-forged alloy,large silicides with equiaxed and rod-like morphologies,and nano-scale silicides were found.Silicides with large sizes might be(Ti,Zr,Nb)_(5)Si_(3) and(Ti,Zr,Nb)_(6)Si_(3).Rod-like silicides with small sizes precipitated in retainedβphase,exhibiting near 45°angles withα/βboundaries.Retainedβphases in as-heat treated alloys were incontinuous.980STA exhibited an excellent combination of room temperature(RT)and 650°C mechanical properties.Characteristics of fracture surfaces largely depended on the evolutions of microstructures.Meanwhile,silicides promoted the formation of mico-voids.展开更多
Density functional theory has been confirmed as a reliable approach in the descriptions of inhomogeneous fluids.By integrating the density functional theory into the revised local average density model, a theoretical ...Density functional theory has been confirmed as a reliable approach in the descriptions of inhomogeneous fluids.By integrating the density functional theory into the revised local average density model, a theoretical approach is constructed to investigate the local shear viscosity in the confined conditions. In the density functional theory,the weighted density approximation for attractive part and the modified fundamental measure theory for repulsion contribution are adopted to accurately describe the inhomogeneous systems. By comparing with simulation data, the theoretical model is tested. In this work, the shear viscosities of methane are calculated in different external fields(on a hard wall, a solvophobic wall and in slit pores with different widths). In addition, the effects of temperature on the local density and viscosity are also considered. It shows that the effect of temperature on the shear viscosity is more obvious on solid surfaces. The calculation provides an approach to determine the viscosity under confined conditions, which is extremely significant in real industrial applications.展开更多
Previous studies of integrin αVβ3 have focused on ischemic brain damage,although the role of integrin αVβ3 in ischemic preconditioning(IP) has rarely been reported.The present study analyzed the effects of IP on i...Previous studies of integrin αVβ3 have focused on ischemic brain damage,although the role of integrin αVβ3 in ischemic preconditioning(IP) has rarely been reported.The present study analyzed the effects of IP on integrin αVβ3 mRNA expression following cerebral ischemia through the use of hematoxylin-eosin staining and real-time quantitative polymerase chain reaction techniques.Integrin αVβ3 mRNA expression in the ischemia group peaked at 24 hours after ischemia-reperfusion.In the IP + ischemia group,integrin αVβ3 mRNA expression increased after 24 hours,but remained significantly less than the ischemia group,and expression continued to increase until 7 days after ischemia/reperfusion.These results demonstrate that IP effectively attenuated upregulation of integrin αVβ3 mRNA expression at 24 hours after ischemia.展开更多
基金supported by the National Natural Science Foundation of China(No.31901242)Heilongjiang Science Foundation Project(No.LH2020C038)National Undergraduate Training Programs for Innovations(No.202110225074)。
文摘In this paper,the occurrence and development mechanism of strain on the cross-section during the wood drying is explored.Therefore,strain regularity on the cross-section of 50 mm thickness elm(Ulmus rubra)board at the temperature of 40℃and 80℃is detected via digital image correlation technology.Hence,the difference between tangential and radial strain at surface and core layers was denoted.The results showed that strain distribution in the width direction of the board is uneven.Moreover,a large drying shrinkage strain occurs at the near-core layer,while the maximum strain difference reaches 4.08%.Hence,the surface of the board is cracked along the thickness direction.The radial strain of the board is higher than the tangential strain in the early stage of drying,while these strains are reversed in the later stage of drying.The temperature is related to the difference between the tangential and radial strains of the elm board.These differences at the core layer are larger than those of the surface layer.The conducted research results provide a theoretical basis for process optimization.
基金supported by the National Basic Research Program of China(No.2012CB124704 and 2013CB127305)KC.Wong Education Foundation,Hong Kong
文摘Background:The protein/energy ratio is important for the production performance and utilization of available feed resources by animals.Increased protein consumption by mammals leads to elevated feed costs and increased nitrogen release into the environment.This study aimed to evaluate the effects of dietary protein/energy ratio on the growth performance,carcass traits,meat quality,and plasma metabolites of pigs of different genotypes.Methods:Bama mini-pigs and Landrace pigs were randomly assigned to two dietary treatment groups(Chinese conventional diet with low protein/energy ratio or National Research Council diet with high protein/energy ratio;n = 24 per treatment) in a 2x2 factorial arrangement.Blood and muscle samples were collected at the end of the nursery,growing,and finishing phases.Results:We observed significant interactions(P< 0.05) between breed and diet for total fat percentage,intramuscular fat(IMF) content,protein content in biceps femoris(BF) muscle,and plasma urea nitrogen(UN) concentration in the nursery phase;for average daily gain(ADG),average daily feed intake(ADFI),dry matter,IMF content in psoas major(PM) muscle,and plasma total protein and albumin concentrations in the growing phase;and for drip loss and plasma UN concentration in the finishing phase.Breed influenced(P < 0.05) growth performance,carcass traits,and meat quality,but not plasma metabolites.Throughout the trial,Landrace pigs showed significantly higher(P < 0.05) ADG,ADFI,dressing percentage,lean mass rate,and loin-eye area than did Bama mini-pigs,but significantly lower(P< 0.05)feed/gain ratio,fat percentage,backfat thickness,and IMF content.Dietary protein/energy ratio influenced the pH value,chemical composition of BF and PM muscles,and plasma activities of glutamic-pyruvic transaminase and gamma-glutamyl transpeptidase,and plasma concentration of UN.Conclusions:Compared with Landrace pigs,Bama mini-pigs showed slower growth and lower carcass performance,but had better meat quality.Moreover,unlike Landrace pigs,the dietary protein/energy ratio did not affect the growth performance of Bama mini-pigs.These results suggest that,in swine production,low dietary protein/energy ratio may be useful for reducing feed costs and minimizing the adverse effects of ammonia release into the environment.
基金financially supported by the National Basic Research Program of China(2013CB127305)the Nature Science Foundation of Hunan Province(S2014J504I)+1 种基金the Major Project of Hunan Province(2015NK1002)the National Science and Technology Ministry(2014BAD08B11)
文摘Background: To investigate the effects of dietary crude protein(CP) restriction on muscle fiber characteristics and key regulators related to protein deposition in skeletal muscle, a total of 18 growing-finishing pigs(62.30 ± 0.88 kg)were allotted to 3 groups and fed with the recommended adequate protein(AP, 16 % CP) diet, moderately restricted protein(MP, 13 % CP) diet and low protein(LP, 10 % CP) diet, respectively. The skeletal muscle of different locations in pigs, including longissimus dorsi muscle(LDM), psoas major muscle(PMM) and biceps femoris muscle(BFM) were collected and analyzed.Results: Results showed that growing-finishing pigs fed the MP or AP diet improved(P < 0.01) the average daily gain and feed: gain ratio compared with those fed the LP diet, and the MP diet tended to increase(P = 0.09) the weight of LDM. Moreover, the ATP content and energy charge value were varied among muscle samples from different locations of pigs fed the reduced protein diets. We also observed that pigs fed the MP diet up-regulated(P < 0.05) muscular m RNA expression of all the selected key genes, except that myosin heavy chain(My HC) IIb,My HC IIx, while m RNA expression of ubiquitin ligases genes was not affected by dietary CP level. Additionally, the activation of mammalian target of rapamycin complex 1(m TORC1) pathway was stimulated(P < 0.05) in skeletal muscle of the pigs fed the MP or AP diet compared with those fed the LP diet.Conclusion: The results suggest that the pigs fed the MP diet could catch up to the growth performance and the LDM weight of the pigs fed the AP diet, and the underlying mechanism may be partly due to the alteration in energy status, modulation of muscle fiber characteristics and m TORC1 activation as well as its downstream effectors in skeletal muscle of different locations in growing-finishing pigs.
基金Supported by the National Natural Science Foundation of China(21606154)
文摘Post-combustion CO_2 capture(PCC) process faces significant challenge of high regeneration energy consumption.Biphasic absorbent is a promising alternative candidate which could significantly reduce the regeneration energy consumption because only the CO_2-concentrated phase should be regenerated. In this work, aqueous solutions of triethylenetetramine(TETA) and N,N-diethylethanolamine(DEEA) are found to be efficient biphasic absorbents of CO_2. The effects of the solvent composition, total amine concentration, and temperature on the absorption behavior, as well as the effect of temperature on the desorption behavior of TETA–DEEA–H2 O system were investigated. An aqueous solution of 1 mol·L-1 TETA and 4 mol·L-1 DEEA spontaneously separates into two liquid phases after a certain amount of CO_2 is absorbed and it shows high CO_2 absorption/desorption performance.About 99.4% of the absorbed CO_2 is found in the lower phase, which corresponds to a CO_2 absorption capacity of 3.44 mol·kg-1. The appropriate absorption and desorption temperatures are found to be 30 °C and 90 °C,respectively. The thermal analysis indicates that the heat of absorption of the 1 mol·L-1 TETA and 4 mol·L-1 DEEA solution is-84.38 kJ·(mol CO_2)-1 which is 6.92 kJ·(mol CO_2)-1 less than that of aqueous MEA. The reaction heat, sensible heat, and the vaporization heat of the TETA–DEEA–H2 O system are lower than that of the aqueous MEA, while its CO_2 capacity is higher. Thus the TETA–DEEA–H2 O system is potentially a better absorbent for the post-combustion CO_2 capture process.
基金Supported by the Key Program of National Natural Science Foundation of China(No.21336008).
文摘An efficient catalyst SO4^2--TiO2(ST) from industrial metatitanic acid has been successfully prepared to catalyze hydrolysis of ball-milling cellulose. The results show that the highest catalytic efficiency is obtained for ST calcined at 450 ℃(ST-450) with the yield of 21.8% glucose, 13.0% 5-HMF and 4.2% furfural at 200 ℃ for30 min. The ball milling of cellulose and solid acid catalyst significantly enhances the cellulose hydrolysis. The high Lewis to Bronsted acid sites ratio for ST-450 induced by bidentate ligands between SO4^2-and TiO2 benefits high organics yield, and high total acid sites contribute to the high cellulose conversion. The large pore volume of 0.29 cm^3·g^-1 and appropriate pore size of 7.35 nm of ST-450 also contribute to the high performance. High reaction temperature over 200 ℃ exhibits negative effect on glucose and 5-HMF yield due to undesired side reactions, while furfural product is stable in the reaction system. The bidentate ligands between SO4^2-and TiO2 are considered as active acid sites for cellulose hydrolysis in water–ethanol solvents.
文摘BACKGROUND:Previous studies have demonstrated that homocysteine is an independent risk factor for ischemic stroke,as determined by detection of apoptosis and oxygen-free radical scavengers following cerebral ischemia.However,the mechanisms of homocysteine remain unclear.Several reports have addressed the effects of homocysteine on ischemic stroke.OBJECTIVE:To analyze the effects of homocysteine on apoptosis,intracellular superoxide dismutase(SOD) activity,and malondialdehyde content in tissue surrounding hematoma in rats with cerebral hemorrhage,and to determine the action pathway of malondialdehyde following cerebral hemorrhage.DESIGN,TIME AND SETTING:The randomized,controlled,animal experiment was performed at the Laboratory of Molecular Biology,Hospital Affiliated to Luzhou Medical College,China from April 2007 to April 2008.MATERIALS:In situ apoptosis detection kit(Roche,Mannheim,Germany),SOD detection kit and malondialdehyde detection kit(Nanjing Jiancheng Bioengineering Institute,China),and homocysteine(Sigma,St Louis,MO,USA) were used in the present study.METHODS:A total of 75 Sprague Dawley rats were equally and randomly assigned to sham surgery,model,and homocysteine groups.Autologous blood was infused into the caudate putamen of rats to establish models of cerebral hemorrhage in model and homocysteine groups.Homocysteine was injected directly into the brain through the skull at the hematoma hemisphere at 30 minutes after model induction in the homocysteine group.MAIN OUTCOME MEASURES:At 6,12,24,and 72 hours,as well as 1 week,post-surgery,neurological deficits were observed in each group.Brain water content was measured using the dry-wet weight method.Cell apoptosis in tissue surrounding the hematoma was detected utilizing terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling(TUNEL).SOD activity and malondialdehyde content in tissue surrounding the hematoma were respectively measured using the xanthine oxidase and thiobarbituric acid methods.RESULTS:Neurological function was similar between model and homocysteine groups following cerebral hemorrhage(P > 0.05).Brain water content was increased at 12 hours post-surgery,peaked at 3 days,and remained unchanged at 7 days in the model group.Brain edema was not significantly aggravated following homocysteine intervention(P > 0.05),but SOD activity significantly decreased and malondialdehyde content significantly increased(P < 0.05).The number of apoptotic cells increased in rats with cerebral hemorrhage at 12 hours(P < 0.05),and numbers peaked at 72 hours following model establishment(P < 0.05).The time of peak value was identical between model and homocysteine groups.Brain water content was negatively associated with SOD activity(rmodel group =-0.448,P < 0.05;rhomocysteine group =-0.612,P < 0.05),but was positively associated with malondialdehyde content(rmodel group = 0.542,P < 0.05;rhomocysteine group = 0.684,P < 0.05) in brain tissues surrounding the hematoma following surgery in model and homocysteine groups.CONCLUSION:Homocysteine aggravates neurological dysfunction and brain edema in rats with cerebral hemorrhage.The mechanisms of action are likely associated with production of oxygen-free radical and cellular apoptosis following cerebral hemorrhage.
基金the National Natural Science Foundation of China(No.21878190)National Key R&D Program of China(2018YFB0605700)for financial support。
文摘Amine-based carbon dioxide(CO2)capture is still limited by high desorption energy consumption.Fixing CO2 into carbonate is a safer and more permanent method.In this work,calcium oxide(CaO)is introduced to perform chemical desorption instead of thermal desorption on 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU)aqueous solution after CO2 absorption.The X-ray diffraction(XRD)patterns of solid products show the formation of calcite calcium carbonate(CaCO3),which prove the feasibility of this method.The effects of reaction temperature,reaction time and Ca2+/CO32-molar ratios on the related reactions in CO2 absorption-mineralization process and CaCO3 precipitation are discussed,and purer CaCO3 is obtained by ultrasonic treatment.The CaCO3 content can be increased to 95.8%and the CO2 desorption ratio can achieve 80%by 30 min ultrasonic dispersion treatment under the conditions(40℃,180 min,Ca2+/CO32-molar ratio=1.0).After five cycles,DBU aqueous solution shows stable CO2 absorption and mineralization ability.Fourier transform infrared spectroscopy(FT-IR)spectra of the reaction process also indicate the regeneration of the solvent.Compared with thermal desorption,this process is exothermic,almost without no additional heat.
基金Supported by the National Natural Science Foundation of China(21606154,21878190).
文摘Gas–liquid mass transfer of rotating disk reactor was studied in CO2 absorption using 1,8-diazabicyclo-[5.4.0]-undec-7-ene(DBU)-glycerol solution as solvent. Effects of the rotating disk structure and various operation parameters on the CO2 absorption rate and CO2 removal efficiency were investigated. The rotating disk with optimal holes is conducive to mass transfer of CO2 and the formation of thin liquid film at the opening increases the gas–liquid contact area. With the increase of rotating speed, the liquid flow pattern on the rotating disk surface changes from thin film flow to separated streams and creates extra liquid lines attached to the rim of the disk,which leads to a very complicated change on the CO2 absorption rate and CO2 removal efficiency. The overall gas-phase mass transfer coefficient increases 138% as the rotating speed increasing from 250 to 1400 r·min^-1.Increasing temperature from 298 to 338 K can enhance the CO2 absorption rate due to lowering the viscosity of the solvent. The rate-determined step for the absorption is focused on the gas side. The rotating disk reactor can effectively enhance the absorption of CO2 with viscous DBU-glycerol solvents.
基金supported by the 12th Five-Year Plan Project of State Key Laboratory of Ore Deposit Geochemistry, Chinese Academy of Sciences (SKLODG-ZY125-09 SKLODGZY125-02)+1 种基金the National Natural Science Foundation of China (Nos. 41373064 41430315)
文摘Digestion with aqua regia in a Carius tube and separation of Re with anion exchange resin is commonly employed for Re–Os dating of molybdenite and pyrite.However, the recovery of Re is extremely low when this routine anion exchange method is applied to galena,causing difficulty in Re–Os dating of galena. In this study,we investigated the mechanism of Re loss during sample preparation and tested a revised procedure for Re–Os dating of galena and sphalerite.
基金Supported by Doctoral Fund of Ministry of Education of China(20130181130006)the National Natural Science Foundation of China(No.21476150)
文摘Biodiesel, which is a renewable and environmentally friendly fuel, has been studied widely to help remedy increasing environmental problems. One of the key processes of biodiesel production is oil extraction from oilseed materials. Switchable solvents can reversibly change from molecular to ionic solvents under atmospheric CO_2,and can be used for oil extraction. N, N-dimethylcyclohexylamine(DMCHA), a switchable solvent, was used to extract oil from Jatropha curcas L. oil seeds to produce biodiesel. The appropriate extraction conditions were:1:2 ratio of seed mass to DMCHA volume, 0.3–1 mm particle size, 200 r·min-1agitation speed, 60 min extraction time, and 30 °C extraction temperature. The extraction ratio was about 83%. This solvent extracted the oil more efficiently than hexane, and is much less volatile. By bubbling CO_2 under 1 atm and 25 °C for 5 h, the oil was separated, and DMCHA was recovered after releasing CO_2 by bubbling N_2 under 1 atm and 60 °C for 2 h. The residual solvent content in oil was about 1.7%. Selectivity of DMCHA was evaluated by detecting the protein and sugar content in oil. Using the oil with residual solvent to conduct transesterification process, the oil conversion ratio was approximately 99.5%.
基金Supported by the National Natural Science Foundation of China(51661145011,51476142)the National Science and Technology Supporting Plan Through Contract(2015BAD15B06)the Program of Introducing Talents of Discipline to University(B08026)
文摘The hydrogenation of dimethyl oxalate(DMO) for the producing of C2-C4 alcohols with methanol as solvent was researched at the temperature of 270 °C to 310 °C. Ethylene glycol(EG) was the main product at low temperature and the selectivity of which was 61.9% at 230 °C. However, EG selectivity decreased sharply with the increase of temperature while ethanol became the main liquid products with the selectivity of 43.5% at 270 °C. It can be ascribed to a thorough hydrogenation of DMO at a high temperature. In addition, the promotion of Guerbet reaction led to the production of propanol and butanol. Simultaneously, the amount of gas products including CO, CO_2 and dimethyl ether(DME) also increased, which became a competition factor in the conversion of DMO to liquid products including C2-C4 alcohols. The blank test was carried out with pure methanol as feedstock with and without Cu/SiO_2 catalyst, which revealed that methanol was involved in the formation of gas products and higher alcohols on Cu-based catalyst, and the main gas product was CO.
基金supported by the State Grid Science and Technology Project (GEIRI-DL-71-17-002)
文摘This paper introduces the implementation and data analysis associated with a state-wide power quality monitoring and analysis system in China. Corporation specifications on power quality monitors as well as on communication protocols are formulated for data transmission. Big data platform and related technologies are utilized for data storage and computation. Compliance verification analysis and a power quality performance assessment are conducted, and a visualization tool for result presentation is finally presented.
基金supported by the National Natural Science Foundation of China(31570596 and 31400535)the Fundamental Research Funds for the Central Universities(2572018BW02)+1 种基金the Innovation Project of State Key Laboratory of Tree Genetics and Breeding(Northeast Forestry University,2016C01)the National Key R&D Program of China(2017YFD0600600)。
文摘Osmotic stress promotes somatic embryogenesis of Fraxinus mandshurica,which leads to accumulation of reactive oxygen species(ROS).The single pieces of cotyledons of F.mandshurica were used as explants to induce somatic embryogenesis in osmotic-stress medium.Furthermore,the hydrogen peroxide H_(2)O_(2) content of explanted cells was varied by adding exogenous H_(2)O_(2) or catalase solution to assess the effects of the exogenous H_(2)O_(2)on somatic embryogenesis,intracellular H_(2)O_(2)accumulation,and the relationship between signaling mediated by ROS or reactive nitrogen species.The results revealed that exogenous H_(2)O_(2)(100?300μmol L^(–1))increased the number of somatic embryos.On 60th day of exogenous H_(2)O_(2)(200μmol L^(–1))treatment,the number of somatic embryos of explants treated,which was 136.54%,was higher than the control.Moreover,exogenous H_(2)O_(2)(100μmol L^(–1))significantly increased the intracellular H_(2)O_(2)content and enhanced the activities of superoxidase dismutase and peroxidase.Finally,exogenous H_(2)O_(2)(100μmol L^(–1))activated the intracellular non-enzymatic pathway for nitric oxide(NO)synthesis.The somatic embryogenesis in broadleaf trees increases with the change of endogenic ROS content,and depends on the upregulation of antioxidant enzymes.Both H_(2)O_(2)and NO,as signaling molecules,were found to be involved in the process of somatic embryogenesis in broadleaf trees.In the process of exogenous H_(2)O_(2)promoting somatic embryogenesis,NO synthesis depended on non-enzymatic reactions.These results provide a scientific basis for resolving the mechanism by which ROS levels are regulated during somatic embryogenesis of broadleaf trees and establish a reasonable and efficient technology system for regulating somatic embryogenesis of trees.
基金The authors would like to gratefully acknowledge the support of Industrial Strengthen Foundation Project of Ministry of Industry and Information Technology,PRC(TC150B5C0-02).
文摘Evolution laws of microstructures,mechanical properties,and fractographs after different solution temperatures were investigated through various analysis methods.With the increasing solution temperatures,contents of the primaryαphase decreased,and contents of transformedβstructures increased.Lamellarαgrains dominated the characteristics of transformedβstructures,and widths of secondaryαlamellas increased monotonously.For as-forged alloy,large silicides with equiaxed and rod-like morphologies,and nano-scale silicides were found.Silicides with large sizes might be(Ti,Zr,Nb)_(5)Si_(3) and(Ti,Zr,Nb)_(6)Si_(3).Rod-like silicides with small sizes precipitated in retainedβphase,exhibiting near 45°angles withα/βboundaries.Retainedβphases in as-heat treated alloys were incontinuous.980STA exhibited an excellent combination of room temperature(RT)and 650°C mechanical properties.Characteristics of fracture surfaces largely depended on the evolutions of microstructures.Meanwhile,silicides promoted the formation of mico-voids.
基金Supported by the National Natural Science Foundation of China(21506114,21276141)the Excellent Middle-Aged and Young Scientist Award Foundation of Shandong(BS2014CL034)Scientific Research Foundation of Qufu Normal University(BSQD20130116)
文摘Density functional theory has been confirmed as a reliable approach in the descriptions of inhomogeneous fluids.By integrating the density functional theory into the revised local average density model, a theoretical approach is constructed to investigate the local shear viscosity in the confined conditions. In the density functional theory,the weighted density approximation for attractive part and the modified fundamental measure theory for repulsion contribution are adopted to accurately describe the inhomogeneous systems. By comparing with simulation data, the theoretical model is tested. In this work, the shear viscosities of methane are calculated in different external fields(on a hard wall, a solvophobic wall and in slit pores with different widths). In addition, the effects of temperature on the local density and viscosity are also considered. It shows that the effect of temperature on the shear viscosity is more obvious on solid surfaces. The calculation provides an approach to determine the viscosity under confined conditions, which is extremely significant in real industrial applications.
基金the National Natural Science Foundation of China,No. 30870849,81071068the Science and Technology Planning Project of Guangdong Province,No. 2009B030801101
文摘Previous studies of integrin αVβ3 have focused on ischemic brain damage,although the role of integrin αVβ3 in ischemic preconditioning(IP) has rarely been reported.The present study analyzed the effects of IP on integrin αVβ3 mRNA expression following cerebral ischemia through the use of hematoxylin-eosin staining and real-time quantitative polymerase chain reaction techniques.Integrin αVβ3 mRNA expression in the ischemia group peaked at 24 hours after ischemia-reperfusion.In the IP + ischemia group,integrin αVβ3 mRNA expression increased after 24 hours,but remained significantly less than the ischemia group,and expression continued to increase until 7 days after ischemia/reperfusion.These results demonstrate that IP effectively attenuated upregulation of integrin αVβ3 mRNA expression at 24 hours after ischemia.
