In order to comprehend the applicability of microwave irradiation for recovering coalbed methane,it is necessary to evaluate the microwave irradiation-induced alterations in coals with varying levels of metamorphism.I...In order to comprehend the applicability of microwave irradiation for recovering coalbed methane,it is necessary to evaluate the microwave irradiation-induced alterations in coals with varying levels of metamorphism.In this work,the carbon molecular sieve combined with KMnO_(4)oxidation was selected to fabricate carbon molecular sieve with diverse oxidation degrees,which can serve as model substances toward coals.Afterwards,the microwave irradiation dependences of pores,functional groups,and highpressure methane adsorption characteristics of model substances were studied.The results indicated that microwave irradiation causes rearrangement of oxygen-containing functional groups,which could block the micropores with a size of 0.40-0.60 nm in carbon molecular sieve;meanwhile,naphthalene and phenanthrene generated by macro-molecular structure pyrolysis due to microwave irradiation could block the micropores with a size of 0.70-0.90 nm.These alterations in micropore structure weaken the saturated methane adsorption capacity of oxidized carbon molecular sieve by 2.91%-23.28%,suggesting that microwave irradiation could promote methane desorption.Moreover,the increased mesopores found for oxidized carbon molecular sieve after microwave irradiation could benefit CH4 diffusion.In summary,the oxidized carbon molecular sieve can act as model substances toward coals with different ranks.Additionally,microwave irradiation is a promising technology to enhance coalbed methane recovery.展开更多
This study investigated the effects of superheated steam(SS)treatment at different temperatures(120℃,150℃,180℃)on the physicochemical properties of broken rice flour and the quality of broken rice cakes.SS treatmen...This study investigated the effects of superheated steam(SS)treatment at different temperatures(120℃,150℃,180℃)on the physicochemical properties of broken rice flour and the quality of broken rice cakes.SS treatment at 120℃ significantly enhanced the moisture content of broken rice flour(P<0.05).In contrast,treatments at 150℃ and 180℃ caused decrease of moisture content,amylose leaching,and reduction of damaged starch content.After SS treatment,the pasting properties of broken rice flour increased,along with the rising of storage modulus and loss modulus.The proportion of short chains(DP 6-12)in amylopectin increased from 29.42%to 34.80%(P<0.05),which could delay starch retrogradation.Compared with untreated ones,the SS-150 broken rice cakes showed a significantly higher specific volume(2.96 mL/g,P<0.05),more uniform cell structure,and lower hardness(1.66 N)and chewiness(10.22 mJ).After 7 days of storage,cakes from SS-treated rice flour(150℃ and 180℃)had significantly reduced hardness and chewiness.The study demonstrated that SS treatment could improve the properties of broken rice flour and enhance the quality of broken rice cakes,especially at 150℃ and 180℃.This study presents a method for improving the quality of broken rice flour and rice cakes using superheated steam treatment,addressing challenges related to poor flour characteristics and suboptimal cake quality.The findings offer technical and theoretical support for enhancing rice cake production,contributing to the comprehensive utilization of rice resources.展开更多
Goji berry(Lycium barbarum L.)is substantially dependent on nitrogen fertilizer application,which can signifi-cantly enhance fruit yield and Goji berry industrial development in Ningxia,China.This study aimed to analyz...Goji berry(Lycium barbarum L.)is substantially dependent on nitrogen fertilizer application,which can signifi-cantly enhance fruit yield and Goji berry industrial development in Ningxia,China.This study aimed to analyze the functions of differential nitrogen application rates including low(N1),medium(N2),and high(N3)levels in soil microbial community structure(bacterial and fungal)at 2 diverse soil depths(0-20,20-40 cm)through high-throughput sequencing technology by targeting 16S RNA gene and ITS1&ITS2 regions.All the observed physicochemical parameters exhibited significant improvement(p<0.05)with increased levels of nitrogen and the highest values for most parameters were observed at N2.However,pH decreased(p<0.05)gradually.The alpha and beta diversity analyses for bacterial and fungal communities’metagenome displayed more similarities than differences among all groups.The top bacterial and fungal phyla and genera suggested no obvious(p>0.05)differences among three group treatments(N1,N2,and N3).Furthermore,the functional enrichment analysis demonstrated significant(p<0.05)enrichment of quorum sensing,cysteine and methionine metabolism,and transcriptional machinery for bacterial communities,while various saprotrophic functional roles for fungal communities.Conclusively,moderately reducing the use of N-supplemented fertilizers is conducive to increasing soil nitrogen utilization rate,which can contribute to sustainable agriculture practices through improved soil quality,and microbial community structure and functions.展开更多
A Pickering emulsion based on sodium starch octenyl succinate(SSOS)was prepared and its effects on the physicochemical properties of hairtail myofibrillar protein gels(MPGs)subjected to multiple freeze-thaw(F-T)cycles...A Pickering emulsion based on sodium starch octenyl succinate(SSOS)was prepared and its effects on the physicochemical properties of hairtail myofibrillar protein gels(MPGs)subjected to multiple freeze-thaw(F-T)cycles were investigated.The whiteness,water-holding capacity,storage modulus(G')and texture properties of the MPGs were significantly improved by adding 1%-2%Pickering emulsion(P<0.05).Meanwhile,Raman spectral analysis demonstrated that Pickering emulsion promoted the transformation of secondary structure,enhanced hydrogen bonds and hydrophobic interactions,and promoted the transition of disulfide bond conformation from g-g-g to g-g-t and t-g-t.At an emulsion concentration of 2%,theα-helix content decreased by 10.37%,while theβ-sheet content increased by 7.94%,compared to the control.After F-T cycles,the structure of the MPGs was destroyed,with an increase in hardness and a decrease in whiteness and water-holding capacity,however,the quality degradation of MPGs was reduced with 1%-2%Pickering emulsion.These findings demonstrated that SSOS-Pickering emulsions,as potential fat substitutes,can enhance the gel properties and the F-T stability of MPGs.展开更多
The physicochemical characteristics of Khaya senegalensis seed oil were investigated. Iodine value, saponification value, percentage free fatty acid (FFA), acid value, and peroxide value were the chemical parameters e...The physicochemical characteristics of Khaya senegalensis seed oil were investigated. Iodine value, saponification value, percentage free fatty acid (FFA), acid value, and peroxide value were the chemical parameters examined in the oil analysis, while specific gravity and refractive index were examined as physical parameters. The results showed that the acid value was 1.18 ± 0.01, the saponification value was 191.76 ± 0.01 mgKOH/gm, and the iodine value was 102.79 ± 0.01. It contained 0.59 ± 0.01 percent free fatty acid. The value of peroxide was 6.83 ± 0.01 meq/kg. The results showed that the refractive index was 1.462 ± 0.02 and the specific gravity was 0.9194 ± 0.04. The established parameters fell within the worldwide and Nigerian vegetable oil industry standards.展开更多
Soil nutrient depletion as a result of continuous cultivation with insufficient external nutrient replenishment is a major challenge in sub-Saharan Africa (SSA). A trial using the organic and mineral fertilizer was es...Soil nutrient depletion as a result of continuous cultivation with insufficient external nutrient replenishment is a major challenge in sub-Saharan Africa (SSA). A trial using the organic and mineral fertilizer was established in the cassava cropping system of the Pissa and Damara areas to address the declining soil fertility. The study aimed to evaluate the effect of cow manure and mineral fertilizer in combination or sole application on soil physico-chemical properties and macronutrients. The experimental trial adopted a randomized complete block design (RCBD) replicated four times. The treatments comprised of;T1 (Control), T2 (Peasant practice), T3 (sole NPK), and T4 (Cow manure + NPK). The data on soil physicochemical analysis was subjected to a one-way analysis of variance in SAS 9.4 and the mean was separated by Tukey’s HSD test at p < 0.005. The soil pH values ranged from 4.20 to 4.91;and 4.53 to 5.28 in Pissa and Damara respectively. According to the treatments, a low pH value is observed in T3 (4.13) in the Pissa. Combined use of cow manure and the mineral fertilizer resulted in higher Mg K and N in the Pissa region and higher soil pH in Damara. The use of sole NPK (T3) gave a higher soil carbon and CN ratio. In the Pissa region the CEC, Cu, Fe, and Zn were higher in the treatments with mineral fertilizer compared to the control. Conclusively, the use of mineral fertilizer and cow manure can be used with optimum rates to improve soil physico-chemical properties on a sustainable basis.展开更多
The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this wo...The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this work.The following properties were determined:density,self-diffusion coefficient,excess molar volume,and radial distribution function.The results show that with an increase in the mole fraction of[HPy][BF_(4)],the self-diffusion coefficient decreases.Additionally,the excess molar volume initially decreases,reaches a minimum,and then increases.The rules of radial distribution functions(RDFs)of characteristic atoms are different.With increasing the mole fraction of[HPy][BF_(4)],the first peak of the RDFs of HA1-F decreases,while that of CT6-CT6 rises at first and then decreases.This indicates that the solvent molecules affect the polar and non-polar regions of[HPy][BF_(4)]differently.展开更多
In order to investigate the effect of solid particles dopants on physicochemical properties of α-PbO2 electrodes, a-PbO2 composite electrodes doped with nano-TiO2 and nano-CeO2 particles were respectively prepared on...In order to investigate the effect of solid particles dopants on physicochemical properties of α-PbO2 electrodes, a-PbO2 composite electrodes doped with nano-TiO2 and nano-CeO2 particles were respectively prepared on A1/conductive coating electrodes in 4 mol/L NaOH solution with addition of PbO until saturation by anodic codeposition. The electrodeposition mechanism, morphology, composition and structure of the composite electrodes were characterized by cyclic voltarnmogram (CV), SEM, EDAX and XRD. Results show that the doping solid particles can not change reaction mechanism of α-PbO2 electrode in alkaline or acid plating bath, but can improve deposition rate and reduce oxygen evolution potential. The doping solid particles can inhibit the growth of a-PbO2 unit cell and improve specific surface area. The diffraction peak intensity of a-PbO2-CeO2-TiO2 composite electrode is lower than that of pure a-PbO2 electrode. The electrocatalytic activity of a-PbO2-2.12%CEO2-3.71%TIO2 composite electrode is the best. The Guglielmi model for CeO2 and TiO2 codeposition with a-PbO2 is also pronosed.展开更多
[Objective] This study aimed to investigate the artificial vegetations on soil physicochemical properties of sandy land. [Method] The soil physicochemical proper- ties in five representative lands respectively covered...[Objective] This study aimed to investigate the artificial vegetations on soil physicochemical properties of sandy land. [Method] The soil physicochemical proper- ties in five representative lands respectively covered by Artemisia ordosica, Salix cheilophila, Hedysarum scoparium, Populus simonii and Amorpha fruticosa, all of which were planted artificially at the same year were measured in the present study, using a bare soil as the control. [Result] Artificial vegetation improved the soil physicochemical properties by different extents in the lands covered by different plants. The soil physicochemical properties such as bulk density under A. Fruticosa and H. Scoparium were improved greatly. The frequency distribution of soil particle size under artificial vegetations exhibited a bimodal curve. The average soil particle size under A. fruticosa was the smallest, and the soil was very poorly sorted. The soil nutrients in the sandy land were not significantly improved by artificial vegeta- tion. [Conclusion] Artificial vegetation has a certain impact on soil properties in sandy land, as it greatly improves the soil physical properties but not the chemical properties.展开更多
Orthogonal test was used to evaluate the effects of synthetic such as temperature (120-140 ℃), reaction time (4-6) and substrate molar ratio of methyl oleate to sucrose (8:1-12:1) on the percent quantity conv...Orthogonal test was used to evaluate the effects of synthetic such as temperature (120-140 ℃), reaction time (4-6) and substrate molar ratio of methyl oleate to sucrose (8:1-12:1) on the percent quantity conversion to sucrose polyester. Sucrose polyester was synthesized by a solvent-free one-stage interesterification. The optimum reaction conditions are as follows: methyl oleate/sucrose =10: 1 (mol/mol); reaction temperature is 140 ℃; reaction time is 5 hours. The product yield reaches 88.15%, and the degree of esterification (DE) is over 7 in the conditions. Thin layer chromatography (TLC), column chromatography (CC), High-performance liquid chromatography (HPLC) were used to analyze the product, the results show that the percent of sucrose polyoleate is over 70% in the product. The physicochemical properties of sucrose polyesters were compared with cooking oil. The results show that the qualities of sucrose polyesters are all up to the triglyceride.展开更多
The remarkable push of technologies increasingly recommends materials for their constructions.Hence the extraction of alumina is for different uses.The exploitation of bauxite pollutes the surrounding areas in this ca...The remarkable push of technologies increasingly recommends materials for their constructions.Hence the extraction of alumina is for different uses.The exploitation of bauxite pollutes the surrounding areas in this case the discharge of mud wheel.Furthermore,the excessive use of dangerous conventional synthetic insecticides continues to be in circulation in Cameroon despite the known adverse effects.These problems lead us to formulate bio insecticides from rejection of the extraction of alumina and extracts of S.aromaticum and Citrus sinensis which respectively offer us essential oils eugenol and limonene having insecticidal properties against the main insects,pests of corn stocks,Sitophilus zeamais.From the kinetic point of view of the adsorption of the extracts of eugenol,limonene and their association by the red mud,the adsorption curve shows that the Eu/Li mixture(30/70)is better by 0.36 mg/g during the 24 h.The results showed a high toxicity of the Eu-Li binary mixture of ratio 30/70 with respective mortality rates of 95.88%after 8 days of exposure to the concentration of 5 mL/L on the adults of Sitophilus zeamais.The other composites induce an average rate of 80%.The results from the physicochemical analysis of corn before and after treatment with formulated insecticides showed a slight loss in nutritional quality of 14.90%in ash,12.5%in protein,16.14%in lipids and 13.63%in total sugars for 180 days.The powdery formulation from red mud and Eu-Li(30/70)mixture can therefore ensure the protection of corn stocks against Sitophilus zeamais in a farming environment.展开更多
[Objective] Effects of different contents of calcium oxide on physicochemi- cal properties of spray-dried bayberry powder were studied. [Method] Bayberry pow- der produced from bayberry juice adding 0, 2 and 4 g/L cal...[Objective] Effects of different contents of calcium oxide on physicochemi- cal properties of spray-dried bayberry powder were studied. [Method] Bayberry pow- der produced from bayberry juice adding 0, 2 and 4 g/L calcium oxide using the spray drying technique has been selected. The physicochemical properties of the spray-dried bayberry powder were investigated by determining moisture content, colour, apparent density, wettability, angle of repose and moisture absorption rate of bayberry powder. [Result] The results showed that the content of calcium oxide had a significant effect on the moisture content and colour of bayberry powder. Effects of different contents of calcium oxide on the apparent density of spray-dried bayber- ry powder were not obvious. Adding calcium oxide had a significant effect on the wettability, angle of repose and moisture absorption rate of spray-dried bayberry powder, nevertheless, there was not obvious difference on these properties between adding 2 and 4 g/L calcium oxide. [Conclusion] The results confirmed that the con- tent of calcium oxide had a significant effect on the properties of spray-dried bay- berry powder.展开更多
For the thorough research on coal metamorphism impact on gas adsorption capacity, this paper collected and summarized parameters of experimental adsorption isotherms, coal maceral, proximate analysis and ultimate anal...For the thorough research on coal metamorphism impact on gas adsorption capacity, this paper collected and summarized parameters of experimental adsorption isotherms, coal maceral, proximate analysis and ultimate analysis obtained from National Engineering Research Center of Coal Gas Control and related literatures at home and abroad, systematically discussed the coal rank effect on its physicochemical properties and methane adsorption capacity, in which the coal rank was shown in Vitrinite reflectance, furthermore, obtained the Semi-quantitative relationship between physicochemical properties of coal and methane adsorption capacity.展开更多
Physicochemical properties of arsenic sulfide sludge(ASS) from copper smelter(ASS-I) and lead-zinc smelter(ASS-II) were examined by XRD, Raman spectroscopy, SEM-EDS, TG-DTA, XPS and chemical phase analysis method. The...Physicochemical properties of arsenic sulfide sludge(ASS) from copper smelter(ASS-I) and lead-zinc smelter(ASS-II) were examined by XRD, Raman spectroscopy, SEM-EDS, TG-DTA, XPS and chemical phase analysis method. The toxicity characteristic leaching procedure(TCLP), Chinese standard leaching tests(CSLT), three-stage sequential extraction procedure(BCR) and batch leaching experiments(BLE) were used to investigate the environmental stability. The ASSs from different smelters had obviously different physicochemical and environmental properties. The phase composition and micrograph analysis indicate that ASS-I mainly consists of super refined flocculent particles including amorphous arsenic sulfide adhered with amorphous sulfur and that ASS-II mainly consists of amorphous arsenic sulfide. The valence state of arsenic in both sludges is trivalent, but the valence composition of sulfur is quite different. The ASSs have thermal instability properties. The results of TCLP and CSLT indicate that the concentrations of As and Pd in the leaching solution exceed the standard limits. More than 5% and 90% of arsenic are in the form of acid soluble and oxidizable fractions, respectively, which explains the high arsenic leaching toxicity and environmental activity of ASS. This research provides comprehensive information for the disposal of ASS from copper and lead-zinc smelter.展开更多
Physicochemical properties and leaching behaviors of two typical arsenic-bearing lime?ferrate sludges(ABLFS),waste acid residue(WAR)and calcium arsenate residue(CAR),are comprehensively described.The chemical composit...Physicochemical properties and leaching behaviors of two typical arsenic-bearing lime?ferrate sludges(ABLFS),waste acid residue(WAR)and calcium arsenate residue(CAR),are comprehensively described.The chemical composition,morphological features,phase composition and arsenic occurrence state of WAR and CAR are analyzed by ICP?AES,SEM?EDS,XRD,XPS and chemical phase analysis.The toxicity leaching test and three-stage BCR sequential extraction procedure are utilized to investigate arsenic leaching behaviors.The results show that the contents of arsenic in WAR and CAR are2.5%and21.2%and mainly present in the phases of arsenate and arsenic oxides dispersed uniformly or agglomerated in amorphous particles.The leaching concentrations of arsenic excess119and1063times of TCLP standard regulatory level with leaching rates of47.66%and50.15%for WAR and CAR,respectively.About90%of extracted arsenic is in the form of acid soluble and reducible,which is the reason of high arsenic leaching toxicity and environmental activity of ABLFS.This research provides comprehensive information on harmless disposal of ABLFS from industrial wastewater treatment of lime?ferrate process.展开更多
The development of advanced air transportation has raised new demands for high-performance liquid hydrocarbon fuels.However,the measurement of fuel properties is time-consuming,cost-intensive,and limited to the operat...The development of advanced air transportation has raised new demands for high-performance liquid hydrocarbon fuels.However,the measurement of fuel properties is time-consuming,cost-intensive,and limited to the operating conditions.The physicochemical properties of aerospace fuels are directly infl uenced by chemical composition.Thus,a thorough investigation should be conducted on the inherent relationship between fuel properties and composition for the design and synthesis of high-grade fuels and the prediction of fuel properties in the future.This work summarized the eff ects of fuel composition and hydrocarbon molecular structure on the fuel physicochemical properties,including density,net heat of combustion(NHOC),low-temperature fl uidity(viscosity and freezing point),fl ash point,and thermal-oxidative stability.Several correlations and predictions of fuel properties from chemical composition were reviewed.Additionally,we correlated the fuel properties with hydrogen/carbon molar ratios(n H/C)and molecular weight(M).The results from the least-square method implicate that the coupling of H/C molar ratio and M is suitable for the estimation of density,NHOC,viscosity and eff ectiveness for the design,manufacture,and evaluation of aviation hydrocarbon fuels.展开更多
Microemulsion systems, composed of water, isopropyl myristate (IPM), polyoxyethylene sorbitan trioleate (Tween 85 ), and ethanol, were investigated as transdermal drug delivery vehicles for a lipophilic model drug...Microemulsion systems, composed of water, isopropyl myristate (IPM), polyoxyethylene sorbitan trioleate (Tween 85 ), and ethanol, were investigated as transdermal drug delivery vehicles for a lipophilic model drug( meloxicam). The purpose of this study was to investigate the physicochemieal properties of the tested microemulsion and to find the correlation between the physicoehemical properties and the skin permeation rate of the microemulsion. Pseudo-ternary phase diagram of the investigated system at a constant surfactant/cosurfactant mass ratio ( Km = 1 : 1 ) was constructed by titration at 20℃, and the five fommlations were selected for further research in the o/w microemulsion domains. The values of electrical conductivity and viscosity showed that the selected systems were bicontinuous or non-spherical o/w microemulsion, and the electrical conductivity and viscosity were increased with increasing the content of water. These results suggest that the optimum formulation of microemulsion, containing 0. 375 meloxicam, 5% isopropyl myristate, 25% Tween 85. 25% ethanol, and water, showed the maximum permeation rate. It had a high electrical conductivity, small droplet size, and proper viscocity.展开更多
A major challenge in modern rice production is to achieve the dual goals of high yield and good quality with low environmental costs.This study was designed to determine whether optimized nitrogen(N)fertilization coul...A major challenge in modern rice production is to achieve the dual goals of high yield and good quality with low environmental costs.This study was designed to determine whether optimized nitrogen(N)fertilization could fulfill these multiple goals.In two-year experiments,two high yielding‘super’rice cultivars were grown with different N fertilization management regimes,including zero N input,local farmers’practice(LFP)with heavy N inputs,and optimized N fertilization(ONF).In ONF,by reducing N input,increasing planting density,and optimizing the ratio of urea application at different stages,N use efficiency and the physicochemical and textural properties of milled rice were improved at higher yield levels.Compared with LFP,yield and partial factor productivity of applied N(PFP)under ONF were increased(on average)by 1.70 and 13.06%,respectively.ONF increased starch and amylose content,and significantly decreased protein content.The contents of the short chains of A chain(degree of polymerization(DP)6-12)and B1 chain(DP 13-25)of amylopectin were significantly increased under ONF,which resulted in a decrease in the stability of rice starch crystals.ONF increased viscosity values and improved the thermodynamic properties of starch,which resulted in better eating and cooking quality of the rice.Thus,ONF could substantially compensate the negative effects caused by N fertilizer and achieve the multiple goals of higher grain quality and nitrogen use efficiency(NUE)at high yield levels.These results will be useful for applications of high quality rice production at high yield levels.展开更多
The intercropping system of tree with soybean in juvenile plantations, as a short-term practice, was applied at Lao Shan Experimental Station in Mao'er Shan Forest of Northeast Forestry University, Harbin, China. The...The intercropping system of tree with soybean in juvenile plantations, as a short-term practice, was applied at Lao Shan Experimental Station in Mao'er Shan Forest of Northeast Forestry University, Harbin, China. The larch (Larix gmelinii)lsoybean (Glycine max.) and ash (Fraxinus mandshurica) intercropping systems were studied in the field to assess the effects of the intercropping on soil physicochemical properties. The results showed that soil physical properties were improved after soybean intercropping with larch and ash in one growing season. The soil bulk density in larch/soybean and ash/soybean systems was 1.112 g·cm^-3 and 1.058 g·cm^ 3, respectively, which was lower than that in the pure larch or ash plantation without intercropping. The total soil porosity also increased after intercropping. The organic matter amount in larch/soybean system was 1.77 times higher than that in the pure larch plantation, and it was 1.09 times higher in ash/soybean system than that in the pure ash plantation. Contents of total nitrogen and hydrolyzable nitrogen in larch/soybean system were 4.2% and 53.0% higher than those in the pure larch stand. Total nitrogen and hydrolyzable nitrogen contents in ash/soybean system were 75.5% and 3.3% higher than those in the pure ash plantation. Total phosphorus content decreased after intercropping, while change of available phosphorus showed an increasing trend. Total potassium and available potassium contents in the larch/soybean system were 0.6% and 17.5% higher than those in the pure larch stand. Total potassium and available potassium contents in the ash/soybean system were 56.4% and 21.8% higher than those in the oure ash plantation.展开更多
α‐,β‐,δ‐,andγ‐MnO2nanocrystals are successfully prepared.We then evaluated the NH3selective catalytic reduction(SCR)performance of the MnO2catalysts with different phases.The NOx conversion efficiency decrease...α‐,β‐,δ‐,andγ‐MnO2nanocrystals are successfully prepared.We then evaluated the NH3selective catalytic reduction(SCR)performance of the MnO2catalysts with different phases.The NOx conversion efficiency decreased in the order:γ‐MnO2>α‐MnO2>δ‐MnO2>β‐MnO2.The NOx conversion with the use ofγ‐MnO2andα‐MnO2catalysts reached90%in the temperature range of140–200°C,while that based onβ‐MnO2reached only40%at200°C.Theγ‐MnO2andα‐MnO2nanowire crystal morphologies enabled good dispersion of the catalysts and resulted in a relatively high specific surface area.We found thatγ‐MnO2andα‐MnO2possessed stronger reducing abilities and more and stronger acidic sites than the other catalysts.In addition,more chemisorbed oxygen existed on the surface of theγ‐MnO2andα‐MnO2catalysts.Theγ‐MnO2andα‐MnO2catalysts showed excellent performance in the low‐temperature SCR of NO to N2with NH3.展开更多
基金supported by the National Natural Science Foundation of China(42272202 and 52264001)the Yunnan Fundamental Research Projects(202201AT070144)+1 种基金the Yunnan Ten Thousand Talents Plan Young&Elite Talents Project(YNWRQNBJ-2019-164)Training Programmes of Innovation and Entrepreneurship for Undergraduates of Yunnan Province(S202210674128).
文摘In order to comprehend the applicability of microwave irradiation for recovering coalbed methane,it is necessary to evaluate the microwave irradiation-induced alterations in coals with varying levels of metamorphism.In this work,the carbon molecular sieve combined with KMnO_(4)oxidation was selected to fabricate carbon molecular sieve with diverse oxidation degrees,which can serve as model substances toward coals.Afterwards,the microwave irradiation dependences of pores,functional groups,and highpressure methane adsorption characteristics of model substances were studied.The results indicated that microwave irradiation causes rearrangement of oxygen-containing functional groups,which could block the micropores with a size of 0.40-0.60 nm in carbon molecular sieve;meanwhile,naphthalene and phenanthrene generated by macro-molecular structure pyrolysis due to microwave irradiation could block the micropores with a size of 0.70-0.90 nm.These alterations in micropore structure weaken the saturated methane adsorption capacity of oxidized carbon molecular sieve by 2.91%-23.28%,suggesting that microwave irradiation could promote methane desorption.Moreover,the increased mesopores found for oxidized carbon molecular sieve after microwave irradiation could benefit CH4 diffusion.In summary,the oxidized carbon molecular sieve can act as model substances toward coals with different ranks.Additionally,microwave irradiation is a promising technology to enhance coalbed methane recovery.
基金supported by the Postdoctoral Innovation Project of Shandong Province (SDCX-ZG-202303090).
文摘This study investigated the effects of superheated steam(SS)treatment at different temperatures(120℃,150℃,180℃)on the physicochemical properties of broken rice flour and the quality of broken rice cakes.SS treatment at 120℃ significantly enhanced the moisture content of broken rice flour(P<0.05).In contrast,treatments at 150℃ and 180℃ caused decrease of moisture content,amylose leaching,and reduction of damaged starch content.After SS treatment,the pasting properties of broken rice flour increased,along with the rising of storage modulus and loss modulus.The proportion of short chains(DP 6-12)in amylopectin increased from 29.42%to 34.80%(P<0.05),which could delay starch retrogradation.Compared with untreated ones,the SS-150 broken rice cakes showed a significantly higher specific volume(2.96 mL/g,P<0.05),more uniform cell structure,and lower hardness(1.66 N)and chewiness(10.22 mJ).After 7 days of storage,cakes from SS-treated rice flour(150℃ and 180℃)had significantly reduced hardness and chewiness.The study demonstrated that SS treatment could improve the properties of broken rice flour and enhance the quality of broken rice cakes,especially at 150℃ and 180℃.This study presents a method for improving the quality of broken rice flour and rice cakes using superheated steam treatment,addressing challenges related to poor flour characteristics and suboptimal cake quality.The findings offer technical and theoretical support for enhancing rice cake production,contributing to the comprehensive utilization of rice resources.
基金This work was funded by Ningxia Hui Autonomous Region Key Research and Development Project(2021BEF02004),Central Finance Forestry Reform and Development Fund“Forest Seed Cultivation”.
文摘Goji berry(Lycium barbarum L.)is substantially dependent on nitrogen fertilizer application,which can signifi-cantly enhance fruit yield and Goji berry industrial development in Ningxia,China.This study aimed to analyze the functions of differential nitrogen application rates including low(N1),medium(N2),and high(N3)levels in soil microbial community structure(bacterial and fungal)at 2 diverse soil depths(0-20,20-40 cm)through high-throughput sequencing technology by targeting 16S RNA gene and ITS1&ITS2 regions.All the observed physicochemical parameters exhibited significant improvement(p<0.05)with increased levels of nitrogen and the highest values for most parameters were observed at N2.However,pH decreased(p<0.05)gradually.The alpha and beta diversity analyses for bacterial and fungal communities’metagenome displayed more similarities than differences among all groups.The top bacterial and fungal phyla and genera suggested no obvious(p>0.05)differences among three group treatments(N1,N2,and N3).Furthermore,the functional enrichment analysis demonstrated significant(p<0.05)enrichment of quorum sensing,cysteine and methionine metabolism,and transcriptional machinery for bacterial communities,while various saprotrophic functional roles for fungal communities.Conclusively,moderately reducing the use of N-supplemented fertilizers is conducive to increasing soil nitrogen utilization rate,which can contribute to sustainable agriculture practices through improved soil quality,and microbial community structure and functions.
基金supported by the National Natural Science Foundation of China(U20A2067,32272360)。
文摘A Pickering emulsion based on sodium starch octenyl succinate(SSOS)was prepared and its effects on the physicochemical properties of hairtail myofibrillar protein gels(MPGs)subjected to multiple freeze-thaw(F-T)cycles were investigated.The whiteness,water-holding capacity,storage modulus(G')and texture properties of the MPGs were significantly improved by adding 1%-2%Pickering emulsion(P<0.05).Meanwhile,Raman spectral analysis demonstrated that Pickering emulsion promoted the transformation of secondary structure,enhanced hydrogen bonds and hydrophobic interactions,and promoted the transition of disulfide bond conformation from g-g-g to g-g-t and t-g-t.At an emulsion concentration of 2%,theα-helix content decreased by 10.37%,while theβ-sheet content increased by 7.94%,compared to the control.After F-T cycles,the structure of the MPGs was destroyed,with an increase in hardness and a decrease in whiteness and water-holding capacity,however,the quality degradation of MPGs was reduced with 1%-2%Pickering emulsion.These findings demonstrated that SSOS-Pickering emulsions,as potential fat substitutes,can enhance the gel properties and the F-T stability of MPGs.
文摘The physicochemical characteristics of Khaya senegalensis seed oil were investigated. Iodine value, saponification value, percentage free fatty acid (FFA), acid value, and peroxide value were the chemical parameters examined in the oil analysis, while specific gravity and refractive index were examined as physical parameters. The results showed that the acid value was 1.18 ± 0.01, the saponification value was 191.76 ± 0.01 mgKOH/gm, and the iodine value was 102.79 ± 0.01. It contained 0.59 ± 0.01 percent free fatty acid. The value of peroxide was 6.83 ± 0.01 meq/kg. The results showed that the refractive index was 1.462 ± 0.02 and the specific gravity was 0.9194 ± 0.04. The established parameters fell within the worldwide and Nigerian vegetable oil industry standards.
文摘Soil nutrient depletion as a result of continuous cultivation with insufficient external nutrient replenishment is a major challenge in sub-Saharan Africa (SSA). A trial using the organic and mineral fertilizer was established in the cassava cropping system of the Pissa and Damara areas to address the declining soil fertility. The study aimed to evaluate the effect of cow manure and mineral fertilizer in combination or sole application on soil physico-chemical properties and macronutrients. The experimental trial adopted a randomized complete block design (RCBD) replicated four times. The treatments comprised of;T1 (Control), T2 (Peasant practice), T3 (sole NPK), and T4 (Cow manure + NPK). The data on soil physicochemical analysis was subjected to a one-way analysis of variance in SAS 9.4 and the mean was separated by Tukey’s HSD test at p < 0.005. The soil pH values ranged from 4.20 to 4.91;and 4.53 to 5.28 in Pissa and Damara respectively. According to the treatments, a low pH value is observed in T3 (4.13) in the Pissa. Combined use of cow manure and the mineral fertilizer resulted in higher Mg K and N in the Pissa region and higher soil pH in Damara. The use of sole NPK (T3) gave a higher soil carbon and CN ratio. In the Pissa region the CEC, Cu, Fe, and Zn were higher in the treatments with mineral fertilizer compared to the control. Conclusively, the use of mineral fertilizer and cow manure can be used with optimum rates to improve soil physico-chemical properties on a sustainable basis.
文摘The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this work.The following properties were determined:density,self-diffusion coefficient,excess molar volume,and radial distribution function.The results show that with an increase in the mole fraction of[HPy][BF_(4)],the self-diffusion coefficient decreases.Additionally,the excess molar volume initially decreases,reaches a minimum,and then increases.The rules of radial distribution functions(RDFs)of characteristic atoms are different.With increasing the mole fraction of[HPy][BF_(4)],the first peak of the RDFs of HA1-F decreases,while that of CT6-CT6 rises at first and then decreases.This indicates that the solvent molecules affect the polar and non-polar regions of[HPy][BF_(4)]differently.
基金Project(51004056) supported by the National Natural Science Foundation of ChinaProject(KKZ6201152009) supported by the Opening Foundation of Key Laboratory of Inorganic Coating Materials,Chinese Academy of Sciences+2 种基金Project(2010ZC052) supported by the Applied Basic Research Foundation of Yunnan Province,ChinaProject(20125314110011) supported by the Specialized Research Fund for the Doctoral Program of Higher EducationProject(2010247) supported by Analysis & Testing Foundation of Kunming University of Science and Technology,China
文摘In order to investigate the effect of solid particles dopants on physicochemical properties of α-PbO2 electrodes, a-PbO2 composite electrodes doped with nano-TiO2 and nano-CeO2 particles were respectively prepared on A1/conductive coating electrodes in 4 mol/L NaOH solution with addition of PbO until saturation by anodic codeposition. The electrodeposition mechanism, morphology, composition and structure of the composite electrodes were characterized by cyclic voltarnmogram (CV), SEM, EDAX and XRD. Results show that the doping solid particles can not change reaction mechanism of α-PbO2 electrode in alkaline or acid plating bath, but can improve deposition rate and reduce oxygen evolution potential. The doping solid particles can inhibit the growth of a-PbO2 unit cell and improve specific surface area. The diffraction peak intensity of a-PbO2-CeO2-TiO2 composite electrode is lower than that of pure a-PbO2 electrode. The electrocatalytic activity of a-PbO2-2.12%CEO2-3.71%TIO2 composite electrode is the best. The Guglielmi model for CeO2 and TiO2 codeposition with a-PbO2 is also pronosed.
基金Supported by National Key Technology Research and Development Program during the 12th Five-year Plan Period(2012BAD16B0202)Special Fund for Forest Scientific Research in the Public Interest(201004018)~~
文摘[Objective] This study aimed to investigate the artificial vegetations on soil physicochemical properties of sandy land. [Method] The soil physicochemical proper- ties in five representative lands respectively covered by Artemisia ordosica, Salix cheilophila, Hedysarum scoparium, Populus simonii and Amorpha fruticosa, all of which were planted artificially at the same year were measured in the present study, using a bare soil as the control. [Result] Artificial vegetation improved the soil physicochemical properties by different extents in the lands covered by different plants. The soil physicochemical properties such as bulk density under A. Fruticosa and H. Scoparium were improved greatly. The frequency distribution of soil particle size under artificial vegetations exhibited a bimodal curve. The average soil particle size under A. fruticosa was the smallest, and the soil was very poorly sorted. The soil nutrients in the sandy land were not significantly improved by artificial vegeta- tion. [Conclusion] Artificial vegetation has a certain impact on soil properties in sandy land, as it greatly improves the soil physical properties but not the chemical properties.
文摘Orthogonal test was used to evaluate the effects of synthetic such as temperature (120-140 ℃), reaction time (4-6) and substrate molar ratio of methyl oleate to sucrose (8:1-12:1) on the percent quantity conversion to sucrose polyester. Sucrose polyester was synthesized by a solvent-free one-stage interesterification. The optimum reaction conditions are as follows: methyl oleate/sucrose =10: 1 (mol/mol); reaction temperature is 140 ℃; reaction time is 5 hours. The product yield reaches 88.15%, and the degree of esterification (DE) is over 7 in the conditions. Thin layer chromatography (TLC), column chromatography (CC), High-performance liquid chromatography (HPLC) were used to analyze the product, the results show that the percent of sucrose polyoleate is over 70% in the product. The physicochemical properties of sucrose polyesters were compared with cooking oil. The results show that the qualities of sucrose polyesters are all up to the triglyceride.
文摘The remarkable push of technologies increasingly recommends materials for their constructions.Hence the extraction of alumina is for different uses.The exploitation of bauxite pollutes the surrounding areas in this case the discharge of mud wheel.Furthermore,the excessive use of dangerous conventional synthetic insecticides continues to be in circulation in Cameroon despite the known adverse effects.These problems lead us to formulate bio insecticides from rejection of the extraction of alumina and extracts of S.aromaticum and Citrus sinensis which respectively offer us essential oils eugenol and limonene having insecticidal properties against the main insects,pests of corn stocks,Sitophilus zeamais.From the kinetic point of view of the adsorption of the extracts of eugenol,limonene and their association by the red mud,the adsorption curve shows that the Eu/Li mixture(30/70)is better by 0.36 mg/g during the 24 h.The results showed a high toxicity of the Eu-Li binary mixture of ratio 30/70 with respective mortality rates of 95.88%after 8 days of exposure to the concentration of 5 mL/L on the adults of Sitophilus zeamais.The other composites induce an average rate of 80%.The results from the physicochemical analysis of corn before and after treatment with formulated insecticides showed a slight loss in nutritional quality of 14.90%in ash,12.5%in protein,16.14%in lipids and 13.63%in total sugars for 180 days.The powdery formulation from red mud and Eu-Li(30/70)mixture can therefore ensure the protection of corn stocks against Sitophilus zeamais in a farming environment.
基金Supported by the Project of Natural Science Fund of Zhejiang Province(Y3110376)~~
文摘[Objective] Effects of different contents of calcium oxide on physicochemi- cal properties of spray-dried bayberry powder were studied. [Method] Bayberry pow- der produced from bayberry juice adding 0, 2 and 4 g/L calcium oxide using the spray drying technique has been selected. The physicochemical properties of the spray-dried bayberry powder were investigated by determining moisture content, colour, apparent density, wettability, angle of repose and moisture absorption rate of bayberry powder. [Result] The results showed that the content of calcium oxide had a significant effect on the moisture content and colour of bayberry powder. Effects of different contents of calcium oxide on the apparent density of spray-dried bayber- ry powder were not obvious. Adding calcium oxide had a significant effect on the wettability, angle of repose and moisture absorption rate of spray-dried bayberry powder, nevertheless, there was not obvious difference on these properties between adding 2 and 4 g/L calcium oxide. [Conclusion] The results confirmed that the con- tent of calcium oxide had a significant effect on the properties of spray-dried bay- berry powder.
文摘For the thorough research on coal metamorphism impact on gas adsorption capacity, this paper collected and summarized parameters of experimental adsorption isotherms, coal maceral, proximate analysis and ultimate analysis obtained from National Engineering Research Center of Coal Gas Control and related literatures at home and abroad, systematically discussed the coal rank effect on its physicochemical properties and methane adsorption capacity, in which the coal rank was shown in Vitrinite reflectance, furthermore, obtained the Semi-quantitative relationship between physicochemical properties of coal and methane adsorption capacity.
基金Projects(51904354,51634010)supported by the National Natural Science Foundation of ChinaProject(51825403)supported by the National Science Fund for Distinguished Young Scholars,ChinaProjects(2018YFC1903301,2018YFC1900301)supported by the National Key R&D Program of China。
文摘Physicochemical properties of arsenic sulfide sludge(ASS) from copper smelter(ASS-I) and lead-zinc smelter(ASS-II) were examined by XRD, Raman spectroscopy, SEM-EDS, TG-DTA, XPS and chemical phase analysis method. The toxicity characteristic leaching procedure(TCLP), Chinese standard leaching tests(CSLT), three-stage sequential extraction procedure(BCR) and batch leaching experiments(BLE) were used to investigate the environmental stability. The ASSs from different smelters had obviously different physicochemical and environmental properties. The phase composition and micrograph analysis indicate that ASS-I mainly consists of super refined flocculent particles including amorphous arsenic sulfide adhered with amorphous sulfur and that ASS-II mainly consists of amorphous arsenic sulfide. The valence state of arsenic in both sludges is trivalent, but the valence composition of sulfur is quite different. The ASSs have thermal instability properties. The results of TCLP and CSLT indicate that the concentrations of As and Pd in the leaching solution exceed the standard limits. More than 5% and 90% of arsenic are in the form of acid soluble and oxidizable fractions, respectively, which explains the high arsenic leaching toxicity and environmental activity of ASS. This research provides comprehensive information for the disposal of ASS from copper and lead-zinc smelter.
基金Project(201509050)supported by Special Program on Environmental Protection for Public Welfare,ChinaProjects(51474247,51634010)supported by the National Natural Science Foundation of ChinaProject(2015CX001)supported by Grants from the Project of Innovation-driven Plan in Central South University,China
文摘Physicochemical properties and leaching behaviors of two typical arsenic-bearing lime?ferrate sludges(ABLFS),waste acid residue(WAR)and calcium arsenate residue(CAR),are comprehensively described.The chemical composition,morphological features,phase composition and arsenic occurrence state of WAR and CAR are analyzed by ICP?AES,SEM?EDS,XRD,XPS and chemical phase analysis.The toxicity leaching test and three-stage BCR sequential extraction procedure are utilized to investigate arsenic leaching behaviors.The results show that the contents of arsenic in WAR and CAR are2.5%and21.2%and mainly present in the phases of arsenate and arsenic oxides dispersed uniformly or agglomerated in amorphous particles.The leaching concentrations of arsenic excess119and1063times of TCLP standard regulatory level with leaching rates of47.66%and50.15%for WAR and CAR,respectively.About90%of extracted arsenic is in the form of acid soluble and reducible,which is the reason of high arsenic leaching toxicity and environmental activity of ABLFS.This research provides comprehensive information on harmless disposal of ABLFS from industrial wastewater treatment of lime?ferrate process.
基金This work was supported by the Scientific Research Projects of the Ministry of Education of China(6141A02033522)the National Natural Science Foundation of China(No.21978200).
文摘The development of advanced air transportation has raised new demands for high-performance liquid hydrocarbon fuels.However,the measurement of fuel properties is time-consuming,cost-intensive,and limited to the operating conditions.The physicochemical properties of aerospace fuels are directly infl uenced by chemical composition.Thus,a thorough investigation should be conducted on the inherent relationship between fuel properties and composition for the design and synthesis of high-grade fuels and the prediction of fuel properties in the future.This work summarized the eff ects of fuel composition and hydrocarbon molecular structure on the fuel physicochemical properties,including density,net heat of combustion(NHOC),low-temperature fl uidity(viscosity and freezing point),fl ash point,and thermal-oxidative stability.Several correlations and predictions of fuel properties from chemical composition were reviewed.Additionally,we correlated the fuel properties with hydrogen/carbon molar ratios(n H/C)and molecular weight(M).The results from the least-square method implicate that the coupling of H/C molar ratio and M is suitable for the estimation of density,NHOC,viscosity and eff ectiveness for the design,manufacture,and evaluation of aviation hydrocarbon fuels.
基金Supported by of the "863" Program of China(No 2003AA2Z347C)
文摘Microemulsion systems, composed of water, isopropyl myristate (IPM), polyoxyethylene sorbitan trioleate (Tween 85 ), and ethanol, were investigated as transdermal drug delivery vehicles for a lipophilic model drug( meloxicam). The purpose of this study was to investigate the physicochemieal properties of the tested microemulsion and to find the correlation between the physicoehemical properties and the skin permeation rate of the microemulsion. Pseudo-ternary phase diagram of the investigated system at a constant surfactant/cosurfactant mass ratio ( Km = 1 : 1 ) was constructed by titration at 20℃, and the five fommlations were selected for further research in the o/w microemulsion domains. The values of electrical conductivity and viscosity showed that the selected systems were bicontinuous or non-spherical o/w microemulsion, and the electrical conductivity and viscosity were increased with increasing the content of water. These results suggest that the optimum formulation of microemulsion, containing 0. 375 meloxicam, 5% isopropyl myristate, 25% Tween 85. 25% ethanol, and water, showed the maximum permeation rate. It had a high electrical conductivity, small droplet size, and proper viscocity.
基金financially supported by the National Natural Science Foundation of China (32071943 and 31872853)the Priority Academic Program Development of Jiangsu Higher Education Institutions, China (PAPD)
文摘A major challenge in modern rice production is to achieve the dual goals of high yield and good quality with low environmental costs.This study was designed to determine whether optimized nitrogen(N)fertilization could fulfill these multiple goals.In two-year experiments,two high yielding‘super’rice cultivars were grown with different N fertilization management regimes,including zero N input,local farmers’practice(LFP)with heavy N inputs,and optimized N fertilization(ONF).In ONF,by reducing N input,increasing planting density,and optimizing the ratio of urea application at different stages,N use efficiency and the physicochemical and textural properties of milled rice were improved at higher yield levels.Compared with LFP,yield and partial factor productivity of applied N(PFP)under ONF were increased(on average)by 1.70 and 13.06%,respectively.ONF increased starch and amylose content,and significantly decreased protein content.The contents of the short chains of A chain(degree of polymerization(DP)6-12)and B1 chain(DP 13-25)of amylopectin were significantly increased under ONF,which resulted in a decrease in the stability of rice starch crystals.ONF increased viscosity values and improved the thermodynamic properties of starch,which resulted in better eating and cooking quality of the rice.Thus,ONF could substantially compensate the negative effects caused by N fertilizer and achieve the multiple goals of higher grain quality and nitrogen use efficiency(NUE)at high yield levels.These results will be useful for applications of high quality rice production at high yield levels.
文摘The intercropping system of tree with soybean in juvenile plantations, as a short-term practice, was applied at Lao Shan Experimental Station in Mao'er Shan Forest of Northeast Forestry University, Harbin, China. The larch (Larix gmelinii)lsoybean (Glycine max.) and ash (Fraxinus mandshurica) intercropping systems were studied in the field to assess the effects of the intercropping on soil physicochemical properties. The results showed that soil physical properties were improved after soybean intercropping with larch and ash in one growing season. The soil bulk density in larch/soybean and ash/soybean systems was 1.112 g·cm^-3 and 1.058 g·cm^ 3, respectively, which was lower than that in the pure larch or ash plantation without intercropping. The total soil porosity also increased after intercropping. The organic matter amount in larch/soybean system was 1.77 times higher than that in the pure larch plantation, and it was 1.09 times higher in ash/soybean system than that in the pure ash plantation. Contents of total nitrogen and hydrolyzable nitrogen in larch/soybean system were 4.2% and 53.0% higher than those in the pure larch stand. Total nitrogen and hydrolyzable nitrogen contents in ash/soybean system were 75.5% and 3.3% higher than those in the pure ash plantation. Total phosphorus content decreased after intercropping, while change of available phosphorus showed an increasing trend. Total potassium and available potassium contents in the larch/soybean system were 0.6% and 17.5% higher than those in the pure larch stand. Total potassium and available potassium contents in the ash/soybean system were 56.4% and 21.8% higher than those in the oure ash plantation.
基金supported by the National Natural Science Foundation of China(51502221)~~
文摘α‐,β‐,δ‐,andγ‐MnO2nanocrystals are successfully prepared.We then evaluated the NH3selective catalytic reduction(SCR)performance of the MnO2catalysts with different phases.The NOx conversion efficiency decreased in the order:γ‐MnO2>α‐MnO2>δ‐MnO2>β‐MnO2.The NOx conversion with the use ofγ‐MnO2andα‐MnO2catalysts reached90%in the temperature range of140–200°C,while that based onβ‐MnO2reached only40%at200°C.Theγ‐MnO2andα‐MnO2nanowire crystal morphologies enabled good dispersion of the catalysts and resulted in a relatively high specific surface area.We found thatγ‐MnO2andα‐MnO2possessed stronger reducing abilities and more and stronger acidic sites than the other catalysts.In addition,more chemisorbed oxygen existed on the surface of theγ‐MnO2andα‐MnO2catalysts.Theγ‐MnO2andα‐MnO2catalysts showed excellent performance in the low‐temperature SCR of NO to N2with NH3.