Aqueous zinc metal batteries(ZMBs)which are environmentally benign and cheap can be used for grid-scale energy storage,but have a short cycling life mainly due to the poor reversibility of zinc metal anodes in mild aq...Aqueous zinc metal batteries(ZMBs)which are environmentally benign and cheap can be used for grid-scale energy storage,but have a short cycling life mainly due to the poor reversibility of zinc metal anodes in mild aqueous electrolytes.A zincophilic carbon(ZC)layer was deposited on a Zn metal foil at 450°C by the up-stream pyrolysis of a hydrogen-bonded supramolecular substance framework,as-sembled from melamine(ME)and cyanuric acid(CA).The zincophilic groups(C=O and C=N)in the ZC layer guide uniform zinc plating/stripping and eliminate dendrites and side reactions.so that assembled symmetrical batteries(ZC@Zn//ZC@Zn)have a long-term service life of 2500 h at 1 mA cm^(−2) and 1 mAh cm^(−2),which is much longer than that of bare Zn anodes(180 h).In addition,ZC@Zn//V2O5 full batteries have a higher capacity of 174 mAh g^(−1) after 1200 cycles at 2 A g^(−1) than a Zn//V_(2)O_(5) counterpart(100 mAh g^(−1)).The strategy developed for the low-temperat-ure deposition of the ZC layer is a new way to construct advanced zinc metal anodes for ZMBs.展开更多
In this study,composite films consisting of polylactic acid(PLA),ethyl cellulose(EC),and zein were prepared by solution casting method,and their performance and application in chilled fresh meat preservation were inve...In this study,composite films consisting of polylactic acid(PLA),ethyl cellulose(EC),and zein were prepared by solution casting method,and their performance and application in chilled fresh meat preservation were investigated.The results showed that the three materials had satisfactory compatibility in the composite film.Addition of EC and zein effectively improved the mechanical properties,thermodynamic properties,surface hydrophilicity,oxygen permeability,and degradation properties of PLA films.When the ratio of PLA to EC was 3:7,the tensile strength and elongation at break reached maximum values of 16.6 MPa and 30.5%,respectively.Moreover,under different conditions,the composite film exhibited better degradability than the PLA film.The composite film with a 3:7 ratio of PLA to EC had the best performance,with a degradation rate of 21.75%after 84 days.Chilled fresh meat wrapped with the composite film showed significantly improved antioxidant,antibacterial,and water-holding properties.展开更多
A process was proposed to convert and separate selenium and arsenic in copper anode slime(CAS) by low-temperature alkali fusion process.Central composite design was employed to optimize the effective parameters,in whi...A process was proposed to convert and separate selenium and arsenic in copper anode slime(CAS) by low-temperature alkali fusion process.Central composite design was employed to optimize the effective parameters,in which Na OH/CAS mass ratio,fusion temperature and fusion time were selected as variables,and the conversion ratio of selenium and arsenic as responses.Second-order polynomial models of high significance and 3D response surface plots were constructed to show the relationship between the responses and the variables.Optimum area of >90% selenium conversion ratio and >90% arsenic conversion ratio was obtained by the overlaid contours at Na OH/CAS mass ratio of 0.65-0.75,fusion temperature of 803-823 K and fusion time of 20-30 min.The models are validated by experiments in the optimum area,and the results demonstrate that these models are reliable and accurate in predicting the fusion process.展开更多
A gram negative bacterium,named JDC-16,which can grow well on the substrate of phthalic acid esters(PAEs) as the sole source of carbon and energy,was isolated from river sludge.Based on the morphology,physiological an...A gram negative bacterium,named JDC-16,which can grow well on the substrate of phthalic acid esters(PAEs) as the sole source of carbon and energy,was isolated from river sludge.Based on the morphology,physiological and biochemical properties and analysis of 16S rRNA gene sequence,it was preliminarily identified belonging to the genus Acinetobacter.The result of substrates utilization range indicates that strain JDC-16 can utilize a variety of phthalates except for diisononyl phthalate(DINP) .The degradation tests using diethyl phthalate(DEP) as the model compound show that the optimal pH and temperature for DEP degradation by Acinetobacter sp.JDC-16 is 8.0 and 35℃,respectively.Meanwhile,degradation kinetics under various initial concentrations of DEP reveals that substrate depletion curves fit well with the modified Gompertz model with high correlation coefficient(R 2 >0.99) .Furthermore,the substrate induction test indicates that DEP-induction can apparently shorten the lag phase and enhance the degradation rate.This work highlights the potential of this isolate for bioremediation of phthalates-contaminated environments.展开更多
Asphalt mixture pavement reheating is one of the important steps in hot in-place recycling(HIR).To improve the heating speed of asphalt pavement in HIR,based on the numerical analysis model of asphalt mixture heating ...Asphalt mixture pavement reheating is one of the important steps in hot in-place recycling(HIR).To improve the heating speed of asphalt pavement in HIR,based on the numerical analysis model of asphalt mixture heating process,a new multi-layer low-temperature heating method(MLHM)was proposed.Considering input heat flux,the thermal capacity and thermal resistance of asphalt mixture,the heat transfer model was established based on energy conservation law.By heating the asphalt mixture in layers,it changes the situation that the heat energy can only be input from the upper surface of the asphalt mixture pavement.Through the simulation of the heating method of asphalt mixture in the existing technology,the result shows that the existing heating methods lead to serious aging or charring of the asphalt mixture.By MLHM,the upper and the bottom of the asphalt mixture are heated at the same time,and the heating temperature is lower than other heat methods,which not only reduces the heating thickness and increases the heating area of the asphalt mixture pavement,but also improves the heating speed,saves the energy resource and ensures the heating quality.Especially,by MLHM,the heating uniformity is better and speed is faster.展开更多
Three varieties were employed as materials to study changes of photosynthetic traits under low-temperature stress. The results showed that Pn, Gs and Tr decreased under low-temperature treatment. Ci decreased under lo...Three varieties were employed as materials to study changes of photosynthetic traits under low-temperature stress. The results showed that Pn, Gs and Tr decreased under low-temperature treatment. Ci decreased under low-temperature treatment 18℃/ 9℃, and 16℃/7℃, and it decreased in earlier stage after increased under 14℃/5℃. WUE was increased in earlier stage and after stabilized. The order of the three varieties of cold resistance were Jinyu 5〉Xingken 3〉Jidan 198. They could make self-regulation through adjusting Gs, Tr, Ci and WUE.展开更多
Ethylthionocarbamates （ETC）, which is the most widely used as collectors in the flotation of sulfide, is known to cause serious pollution to soil and groundwater. The potential biodegradation of ETC was evaluated b...Ethylthionocarbamates （ETC）, which is the most widely used as collectors in the flotation of sulfide, is known to cause serious pollution to soil and groundwater. The potential biodegradation of ETC was evaluated by applying a mixed culture of iron-reducing bacteria （IRB） enriched from tailings dam sediments. The results showed that ETC can be degraded by IRB coupled to Fe（III） reduction, both of which can be increased in the presence of anthraquinone-2,6-disulfonate （AQDS）. Moreover, Fe（III）-EDTA was found to be a more favorable terminal electron acceptor compared to α-Fe2O3, e.g., within 30 d, 72% of ETC was degraded when α-Fe2O3＋AQDS was applied, while it is 82.67% when Fe（III）-EDTA＋AQDS is added. The dynamic models indicated that the kETC degradation was decreased in the order of Fe（III）-EDTA＋AQDS〉α-Fe2O3＋AQDS〉Fe（III）-EDTA〉α-Fe2O3, with the corresponding maximum biodegradation rates being 2.6, 2.45, 2.4 and 2.0 mg/（L·d）, respectively, and positive parallel correlations could be observed between kFe（III） and kETC. These findings demonstrate that IRB has a good application prospect in flotation wastewater.展开更多
The influences of BaCu（B2O5） （BCB） addition on sintering, microstructure and microwave dielectric properties of Li2MgTi308 ceramics were investigated using X-ray diffractometry, scanning electron microscopy and mi...The influences of BaCu（B2O5） （BCB） addition on sintering, microstructure and microwave dielectric properties of Li2MgTi308 ceramics were investigated using X-ray diffractometry, scanning electron microscopy and microwave dielectric measurements. The experimental results show that a small amount of BaCu（B2O5） addition can effectively reduce the sintering temperature to 900℃, and induce only a limited degradation of the microwave dielectric properties. Typically, the best microwave dielectric properties of er24.5, Q×f =24 622 GHz, rf=4.2×10-6℃ -1 are obtained for 1.0% BCB-doped Li2MgTi3O8 ceramics sintered at 900℃ for 3 h. The BCB-doped Li2MgTi3O8 ceramics can be compatible with Ag electrode, which may be a strong candidate for low temperature co-fired ceramics applications.展开更多
A novel low-temperature alkaline smelting process is proposed to convert and separate amphoteric metals in crushed metal enrichment originated from waste printed circuit boards. The central composite design was used t...A novel low-temperature alkaline smelting process is proposed to convert and separate amphoteric metals in crushed metal enrichment originated from waste printed circuit boards. The central composite design was used to optimize the operating parameters,in which mass ratio of Na OH-to-CME, smelting temperature and smelting time were chosen as the variables, and the conversions of amphoteric metals tin, lead, aluminum and zinc were response parameters. Second-order polynomial models of high significance and3 D response surface plots were constructed to show the relationship between the responses and the variables. Optimum area of80%-85% Pb conversion and over 95% Sn conversion was obtained by the overlaid contours at mass ratio of Na OH-to-CME of4.5-5.0, smelting temperature of 653-723 K, smelting time of 90-120 min. The models were validated experimentally in the optimum area, and the results demonstrate that these models are reliable and accurate in predicting the smelting process.展开更多
The hot compression test of 6063 Al alloy was performed on a Gleeble-1500 thermo-simulation machine, and the forming of 6063 rod cxtrudate in low-temperature high-speed extrusion was simulated with extrusion ratio of ...The hot compression test of 6063 Al alloy was performed on a Gleeble-1500 thermo-simulation machine, and the forming of 6063 rod cxtrudate in low-temperature high-speed extrusion was simulated with extrusion ratio of 25 on the platform of DEFORM 2D successfully. From the compression experimental results, the flow stress model of this Al alloy is obtained which could be the constitutive equation in the simulation of low-temperature high-speed extrusion process. From the numerical simulation results, there is a higher strain concentration at the entrance of the die and the exit temperature reaches up to 522 ℃ in low-temperature high-speed extrusion, which approaches to the quenching temperature of the 6063 Al alloy. The results show that the low-temperature high-speed extrusion method as a promsing one can reduce energy consumption effectively.展开更多
As a major component of lignin and abundantly existing in softwood and hardwood, ferulic acid has been used as a lignin-related compound for lignin biodegradation study. Biodegradation of ferulic acid by Cupriavidus s...As a major component of lignin and abundantly existing in softwood and hardwood, ferulic acid has been used as a lignin-related compound for lignin biodegradation study. Biodegradation of ferulic acid by Cupriavidus sp. B-8, a newly isolated strain, was studied. This strain is able to utilize a wide range of lignin-related aromatic compounds as the sole carbon and energy source, including guaiacol, veratric acid, vanillic acid, cinnamic acid, p-coumaric acid, ferulic acid, and sinapic acid. In addition, the effects of different concentrations of ferulic acid on growth of Cupriavidus sp. B-8 were studied. The growth of Cupriavidus sp. B-8 is better under the condition of lower concentration. High-performance liquid chromatography （HPLC） analysis reveals that above 95% of ferulic acid is degraded within 12 h by Cupriavidus sp. B-8. Based on identification of biodegradation intermediates and further metabolites, the biodegradation pathway of ferulic acid by Cupriavidus sp. B-8 was proposed. Ferulic acid is initially converted to 4-vinylguaiacol, and further oxidized to vanillic acid and protocatechuic acid.展开更多
The features of organic pollutants degradation mainly characterized by bio-flocculation for step-A of adsorption-biodegredation（AB） process were studied. By investigating the relationship of extracellular polymeric ...The features of organic pollutants degradation mainly characterized by bio-flocculation for step-A of adsorption-biodegredation（AB） process were studied. By investigating the relationship of extracellular polymeric substances（EPS） with bioflocculation and introducing kinetic model of organic pollutant degradation into EPS, the kinetic model of organic pollutant degradation for step-A hioflocculation was deducted. And through the experiments, the kinetic constants were calculated as follows： k1 =0. 005 3; kc1 =1 710.7 and vmax1=10 min^-1.展开更多
Studies on the cold-responsive genes and cold signaling of woody species drop far behind in comparison to herbaceous plants.Due to similar lignified structure,perennial characteristic,and enhanced tolerance,it seems m...Studies on the cold-responsive genes and cold signaling of woody species drop far behind in comparison to herbaceous plants.Due to similar lignified structure,perennial characteristic,and enhanced tolerance,it seems much easier to find strongly antifreeze genes and obtain effective results in transgenic woody plants.In this study,Ammopiptanthus mongolicus,an evergreen,broadleaf and cold-resist leguminous shrub growing in the desert of Inner Mongolia,was used as a material for low-temperature induced gene isolation.Through differential expression analysis induced by low-temperature,thirteen up-regulated cDNAs were identified.One of them,AmEBP1,(accession number:DQ519359)confers enhanced cold-tolerance to both transgenic E.coli and transgenic Arabidopsis.Results suggest that AmEBP1 can stimulate the synthesis of ribosome and the dephosphyration of the α-subunit of initiation factor 2(eIF2α),and subsequently promote the translation process.By which the transgenic plants obtained increased cold-resistant ability.展开更多
In this study,Mg-based composites,by the addition of ZnO,Ca_(2)ZnSi_(2)O_(7),Ca_(2)MgSi_(2)O_(7),and CaSiO_(3)as bioactive agents,were fabricated using friction stir processing.The microstructure and in vitro assessme...In this study,Mg-based composites,by the addition of ZnO,Ca_(2)ZnSi_(2)O_(7),Ca_(2)MgSi_(2)O_(7),and CaSiO_(3)as bioactive agents,were fabricated using friction stir processing.The microstructure and in vitro assessment of bioactivity,biodegradation rate,and corrosion behavior of the resultant composites were investigated in simulated body fluid(SBF).The results showed that during the immersion of composites in SBF for 28 d,due to the release of Ca^(2+)and PO_(4)^(3-)ions,hydroxyapatite(HA)crystals with cauliflower shaped morphology were deposited on the surface of composites,confirming good bioactivity of composites.In addition,due to the uniform distribution of bioceramic powders throughout Mg matrix,grain refinement of the Mg matrix,and uniform redistribution of secondary phase particles,the polarization resistance increased,and the biodegradation rate of composites significantly reduced compared to monolithic Mg matrix.The polarization corrosion resistance of Mg-ZnO increased from 0.216 to 2.499 kΩ/cm^(2)compared to monolithic Mg alloy.Additionally,Mg-ZnO composite with the weight loss of 0.0217 g after 28 d immersion showed lower weight loss compared to other samples with increasing immersion time.Moreover,Mg-ZnO composite with the biodegradation rate of 37.71 mm/a exhibited lower biodegradation rate compared to other samples with increasing immersion time.展开更多
Fatigue and tensile behaviors of homogenized WE 54 magnesium alloy before and after immersion in simulated body fluid(SBF)were investigated.According to the tensile test,the alloy without immersion in SBF solution has...Fatigue and tensile behaviors of homogenized WE 54 magnesium alloy before and after immersion in simulated body fluid(SBF)were investigated.According to the tensile test,the alloy without immersion in SBF solution has the highest tensile strength of 278 MPa,which decreased to 190 MPa after 336 h of immersion..The fatigue life of the homogenized WE 54 magnesium alloy before immersion in the SBF solution under a constant stress of 15 MPa is 3598 cycles.However,the fatigue life of the alloy decreased to 453 cycles after 336 h of immersion in the SBF solution under the same stress.Examination of the fracture surface of the samples by SEM reveals that the origin of the fatigue crack before immersion is micro-pores and defects.While corrosion pits and cracks are the main reasons for forming the initial fatigue crack after immersion.Moreover,the results obtained from practical work were evaluated and compared to theoretical calculations.The area of the hysteresis loops of the samples after the fatigue test,determined using Triangles and Monte Carlo methods,decreased from 4954.5 MPa and 4842.9 MPa before immersion to 192.0 MPa and 175.8 MPa after 336 h of immersion,respectively.展开更多
聚羟基脂肪酸酯(PHA)具有良好的生物降解性、生物相容性和可持续性,在包装、食品和医疗等领域具有广泛的应用前景。因此,亟待对国内外近二十余年来的有关PHA的研究进行总结和梳理,为PHA领域的协同发展提供理论依据。本研究以Web of Scie...聚羟基脂肪酸酯(PHA)具有良好的生物降解性、生物相容性和可持续性,在包装、食品和医疗等领域具有广泛的应用前景。因此,亟待对国内外近二十余年来的有关PHA的研究进行总结和梳理,为PHA领域的协同发展提供理论依据。本研究以Web of Science(WOS)核心合集数据库和中国知网(CNKI)全文数据库为数据检索源,借助CiteSpace和VOSviewer文献计量工具,对2000-2023年PHA领域的相关文献进行知识图谱的可视化分析。结果表明,在2000-2023年间,国内外对PHA领域的研究目前处于快速增长阶段,且英文文献的发文量和年增长率均显著高于中文文献。国际对该领域的关注度和研究要早于国内,并且我国在PHA领域的研究对全球贡献较大,但有影响力的研究较为缺乏,亟待进一步提高。关键词聚类和时空突现分析表明,未来的研究热点主要集中在以下3个方面:1)降低PHA生产成本以实现工业化生产;2)关注PHA降解酶的筛选与鉴定,以及PHA降解过程中的微生物群落结构和功能研究;3)PHA的共聚改性、复合改性以及与其他生物材料的功能化改性。展开更多
基金partially supported by the National Natural Science Foundation of China(22479022)Liaoning Revitalization Talents Program(XLYC2007129)。
文摘Aqueous zinc metal batteries(ZMBs)which are environmentally benign and cheap can be used for grid-scale energy storage,but have a short cycling life mainly due to the poor reversibility of zinc metal anodes in mild aqueous electrolytes.A zincophilic carbon(ZC)layer was deposited on a Zn metal foil at 450°C by the up-stream pyrolysis of a hydrogen-bonded supramolecular substance framework,as-sembled from melamine(ME)and cyanuric acid(CA).The zincophilic groups(C=O and C=N)in the ZC layer guide uniform zinc plating/stripping and eliminate dendrites and side reactions.so that assembled symmetrical batteries(ZC@Zn//ZC@Zn)have a long-term service life of 2500 h at 1 mA cm^(−2) and 1 mAh cm^(−2),which is much longer than that of bare Zn anodes(180 h).In addition,ZC@Zn//V2O5 full batteries have a higher capacity of 174 mAh g^(−1) after 1200 cycles at 2 A g^(−1) than a Zn//V_(2)O_(5) counterpart(100 mAh g^(−1)).The strategy developed for the low-temperat-ure deposition of the ZC layer is a new way to construct advanced zinc metal anodes for ZMBs.
文摘In this study,composite films consisting of polylactic acid(PLA),ethyl cellulose(EC),and zein were prepared by solution casting method,and their performance and application in chilled fresh meat preservation were investigated.The results showed that the three materials had satisfactory compatibility in the composite film.Addition of EC and zein effectively improved the mechanical properties,thermodynamic properties,surface hydrophilicity,oxygen permeability,and degradation properties of PLA films.When the ratio of PLA to EC was 3:7,the tensile strength and elongation at break reached maximum values of 16.6 MPa and 30.5%,respectively.Moreover,under different conditions,the composite film exhibited better degradability than the PLA film.The composite film with a 3:7 ratio of PLA to EC had the best performance,with a degradation rate of 21.75%after 84 days.Chilled fresh meat wrapped with the composite film showed significantly improved antioxidant,antibacterial,and water-holding properties.
基金Project(51234009)supported by the National Natural Science Foundation of ChinaProject(2014DFA90520)supported by International Cooperation Program of Ministry of Science of ChinaProject(2013A100003)supported by the Production,Teaching and Research Program of Guangdong Province,China
文摘A process was proposed to convert and separate selenium and arsenic in copper anode slime(CAS) by low-temperature alkali fusion process.Central composite design was employed to optimize the effective parameters,in which Na OH/CAS mass ratio,fusion temperature and fusion time were selected as variables,and the conversion ratio of selenium and arsenic as responses.Second-order polynomial models of high significance and 3D response surface plots were constructed to show the relationship between the responses and the variables.Optimum area of >90% selenium conversion ratio and >90% arsenic conversion ratio was obtained by the overlaid contours at Na OH/CAS mass ratio of 0.65-0.75,fusion temperature of 803-823 K and fusion time of 20-30 min.The models are validated by experiments in the optimum area,and the results demonstrate that these models are reliable and accurate in predicting the fusion process.
基金Project(30770388) supported by the National Natural Science Foundation of China
文摘A gram negative bacterium,named JDC-16,which can grow well on the substrate of phthalic acid esters(PAEs) as the sole source of carbon and energy,was isolated from river sludge.Based on the morphology,physiological and biochemical properties and analysis of 16S rRNA gene sequence,it was preliminarily identified belonging to the genus Acinetobacter.The result of substrates utilization range indicates that strain JDC-16 can utilize a variety of phthalates except for diisononyl phthalate(DINP) .The degradation tests using diethyl phthalate(DEP) as the model compound show that the optimal pH and temperature for DEP degradation by Acinetobacter sp.JDC-16 is 8.0 and 35℃,respectively.Meanwhile,degradation kinetics under various initial concentrations of DEP reveals that substrate depletion curves fit well with the modified Gompertz model with high correlation coefficient(R 2 >0.99) .Furthermore,the substrate induction test indicates that DEP-induction can apparently shorten the lag phase and enhance the degradation rate.This work highlights the potential of this isolate for bioremediation of phthalates-contaminated environments.
基金Project(2017JM5077)supported by the Natural Science Basic Research Plan in Shaanxi Province,ChinaProjects(300102259109,300102259306)supported by the Fundamental Research Funds for the Central Universities,China。
文摘Asphalt mixture pavement reheating is one of the important steps in hot in-place recycling(HIR).To improve the heating speed of asphalt pavement in HIR,based on the numerical analysis model of asphalt mixture heating process,a new multi-layer low-temperature heating method(MLHM)was proposed.Considering input heat flux,the thermal capacity and thermal resistance of asphalt mixture,the heat transfer model was established based on energy conservation law.By heating the asphalt mixture in layers,it changes the situation that the heat energy can only be input from the upper surface of the asphalt mixture pavement.Through the simulation of the heating method of asphalt mixture in the existing technology,the result shows that the existing heating methods lead to serious aging or charring of the asphalt mixture.By MLHM,the upper and the bottom of the asphalt mixture are heated at the same time,and the heating temperature is lower than other heat methods,which not only reduces the heating thickness and increases the heating area of the asphalt mixture pavement,but also improves the heating speed,saves the energy resource and ensures the heating quality.Especially,by MLHM,the heating uniformity is better and speed is faster.
基金Supported by the Science and Technology Foundation(2008BADB3B09-03)
文摘Three varieties were employed as materials to study changes of photosynthetic traits under low-temperature stress. The results showed that Pn, Gs and Tr decreased under low-temperature treatment. Ci decreased under low-temperature treatment 18℃/ 9℃, and 16℃/7℃, and it decreased in earlier stage after increased under 14℃/5℃. WUE was increased in earlier stage and after stabilized. The order of the three varieties of cold resistance were Jinyu 5〉Xingken 3〉Jidan 198. They could make self-regulation through adjusting Gs, Tr, Ci and WUE.
基金Project(51708561)supported by the National Natural Science Foundation of ChinaProjects(CZP17097,CZW15037)supported by the Fundamental Research Funds for the Central Universities,China
文摘Ethylthionocarbamates （ETC）, which is the most widely used as collectors in the flotation of sulfide, is known to cause serious pollution to soil and groundwater. The potential biodegradation of ETC was evaluated by applying a mixed culture of iron-reducing bacteria （IRB） enriched from tailings dam sediments. The results showed that ETC can be degraded by IRB coupled to Fe（III） reduction, both of which can be increased in the presence of anthraquinone-2,6-disulfonate （AQDS）. Moreover, Fe（III）-EDTA was found to be a more favorable terminal electron acceptor compared to α-Fe2O3, e.g., within 30 d, 72% of ETC was degraded when α-Fe2O3＋AQDS was applied, while it is 82.67% when Fe（III）-EDTA＋AQDS is added. The dynamic models indicated that the kETC degradation was decreased in the order of Fe（III）-EDTA＋AQDS〉α-Fe2O3＋AQDS〉Fe（III）-EDTA〉α-Fe2O3, with the corresponding maximum biodegradation rates being 2.6, 2.45, 2.4 and 2.0 mg/（L·d）, respectively, and positive parallel correlations could be observed between kFe（III） and kETC. These findings demonstrate that IRB has a good application prospect in flotation wastewater.
基金Project(2010GXNSFA013029) supported by the Natural Science Foundation of Guangxi Province,ChinaProject(101059529) supported by National Undergraduate Innovation Program of the Ministry of Education of China
文摘The influences of BaCu（B2O5） （BCB） addition on sintering, microstructure and microwave dielectric properties of Li2MgTi308 ceramics were investigated using X-ray diffractometry, scanning electron microscopy and microwave dielectric measurements. The experimental results show that a small amount of BaCu（B2O5） addition can effectively reduce the sintering temperature to 900℃, and induce only a limited degradation of the microwave dielectric properties. Typically, the best microwave dielectric properties of er24.5, Q×f =24 622 GHz, rf=4.2×10-6℃ -1 are obtained for 1.0% BCB-doped Li2MgTi3O8 ceramics sintered at 900℃ for 3 h. The BCB-doped Li2MgTi3O8 ceramics can be compatible with Ag electrode, which may be a strong candidate for low temperature co-fired ceramics applications.
基金Projects(51074190,51234009)supported by the National Natural Science Foundation of ChinaProject(2014DFA90520)supported by International Cooperation Program of Ministry of Science of ChinaProject(20110162110049)supported by the Doctoral Scientific Fund Project of the Ministry of Education of China
文摘A novel low-temperature alkaline smelting process is proposed to convert and separate amphoteric metals in crushed metal enrichment originated from waste printed circuit boards. The central composite design was used to optimize the operating parameters,in which mass ratio of Na OH-to-CME, smelting temperature and smelting time were chosen as the variables, and the conversions of amphoteric metals tin, lead, aluminum and zinc were response parameters. Second-order polynomial models of high significance and3 D response surface plots were constructed to show the relationship between the responses and the variables. Optimum area of80%-85% Pb conversion and over 95% Sn conversion was obtained by the overlaid contours at mass ratio of Na OH-to-CME of4.5-5.0, smelting temperature of 653-723 K, smelting time of 90-120 min. The models were validated experimentally in the optimum area, and the results demonstrate that these models are reliable and accurate in predicting the smelting process.
基金Project(2008A09030004) supported by the Major Science and Technology Project of Guangdong Province,ChinaProject(30815009) supported by the Foundation of State Key Laboratory of Advanced Design and Manufacture for Vehicle Body
文摘The hot compression test of 6063 Al alloy was performed on a Gleeble-1500 thermo-simulation machine, and the forming of 6063 rod cxtrudate in low-temperature high-speed extrusion was simulated with extrusion ratio of 25 on the platform of DEFORM 2D successfully. From the compression experimental results, the flow stress model of this Al alloy is obtained which could be the constitutive equation in the simulation of low-temperature high-speed extrusion process. From the numerical simulation results, there is a higher strain concentration at the entrance of the die and the exit temperature reaches up to 522 ℃ in low-temperature high-speed extrusion, which approaches to the quenching temperature of the 6063 Al alloy. The results show that the low-temperature high-speed extrusion method as a promsing one can reduce energy consumption effectively.
基金Foundation item： Project（50925417） supported by the National Science Fund for Distinguished Young Scholars of China Project（50830301） supported by the National Natural Science Foundation of China Project（2011467062） supported by National Research Fund for Public Benefit （Environmental Protection） Industries, China
文摘As a major component of lignin and abundantly existing in softwood and hardwood, ferulic acid has been used as a lignin-related compound for lignin biodegradation study. Biodegradation of ferulic acid by Cupriavidus sp. B-8, a newly isolated strain, was studied. This strain is able to utilize a wide range of lignin-related aromatic compounds as the sole carbon and energy source, including guaiacol, veratric acid, vanillic acid, cinnamic acid, p-coumaric acid, ferulic acid, and sinapic acid. In addition, the effects of different concentrations of ferulic acid on growth of Cupriavidus sp. B-8 were studied. The growth of Cupriavidus sp. B-8 is better under the condition of lower concentration. High-performance liquid chromatography （HPLC） analysis reveals that above 95% of ferulic acid is degraded within 12 h by Cupriavidus sp. B-8. Based on identification of biodegradation intermediates and further metabolites, the biodegradation pathway of ferulic acid by Cupriavidus sp. B-8 was proposed. Ferulic acid is initially converted to 4-vinylguaiacol, and further oxidized to vanillic acid and protocatechuic acid.
基金project (2004B4604A01-01) supported by the Mega-projects of Science Research for the 10th Five-Year Plan
文摘The features of organic pollutants degradation mainly characterized by bio-flocculation for step-A of adsorption-biodegredation（AB） process were studied. By investigating the relationship of extracellular polymeric substances（EPS） with bioflocculation and introducing kinetic model of organic pollutant degradation into EPS, the kinetic model of organic pollutant degradation for step-A hioflocculation was deducted. And through the experiments, the kinetic constants were calculated as follows： k1 =0. 005 3; kc1 =1 710.7 and vmax1=10 min^-1.
文摘Studies on the cold-responsive genes and cold signaling of woody species drop far behind in comparison to herbaceous plants.Due to similar lignified structure,perennial characteristic,and enhanced tolerance,it seems much easier to find strongly antifreeze genes and obtain effective results in transgenic woody plants.In this study,Ammopiptanthus mongolicus,an evergreen,broadleaf and cold-resist leguminous shrub growing in the desert of Inner Mongolia,was used as a material for low-temperature induced gene isolation.Through differential expression analysis induced by low-temperature,thirteen up-regulated cDNAs were identified.One of them,AmEBP1,(accession number:DQ519359)confers enhanced cold-tolerance to both transgenic E.coli and transgenic Arabidopsis.Results suggest that AmEBP1 can stimulate the synthesis of ribosome and the dephosphyration of the α-subunit of initiation factor 2(eIF2α),and subsequently promote the translation process.By which the transgenic plants obtained increased cold-resistant ability.
文摘In this study,Mg-based composites,by the addition of ZnO,Ca_(2)ZnSi_(2)O_(7),Ca_(2)MgSi_(2)O_(7),and CaSiO_(3)as bioactive agents,were fabricated using friction stir processing.The microstructure and in vitro assessment of bioactivity,biodegradation rate,and corrosion behavior of the resultant composites were investigated in simulated body fluid(SBF).The results showed that during the immersion of composites in SBF for 28 d,due to the release of Ca^(2+)and PO_(4)^(3-)ions,hydroxyapatite(HA)crystals with cauliflower shaped morphology were deposited on the surface of composites,confirming good bioactivity of composites.In addition,due to the uniform distribution of bioceramic powders throughout Mg matrix,grain refinement of the Mg matrix,and uniform redistribution of secondary phase particles,the polarization resistance increased,and the biodegradation rate of composites significantly reduced compared to monolithic Mg matrix.The polarization corrosion resistance of Mg-ZnO increased from 0.216 to 2.499 kΩ/cm^(2)compared to monolithic Mg alloy.Additionally,Mg-ZnO composite with the weight loss of 0.0217 g after 28 d immersion showed lower weight loss compared to other samples with increasing immersion time.Moreover,Mg-ZnO composite with the biodegradation rate of 37.71 mm/a exhibited lower biodegradation rate compared to other samples with increasing immersion time.
文摘Fatigue and tensile behaviors of homogenized WE 54 magnesium alloy before and after immersion in simulated body fluid(SBF)were investigated.According to the tensile test,the alloy without immersion in SBF solution has the highest tensile strength of 278 MPa,which decreased to 190 MPa after 336 h of immersion..The fatigue life of the homogenized WE 54 magnesium alloy before immersion in the SBF solution under a constant stress of 15 MPa is 3598 cycles.However,the fatigue life of the alloy decreased to 453 cycles after 336 h of immersion in the SBF solution under the same stress.Examination of the fracture surface of the samples by SEM reveals that the origin of the fatigue crack before immersion is micro-pores and defects.While corrosion pits and cracks are the main reasons for forming the initial fatigue crack after immersion.Moreover,the results obtained from practical work were evaluated and compared to theoretical calculations.The area of the hysteresis loops of the samples after the fatigue test,determined using Triangles and Monte Carlo methods,decreased from 4954.5 MPa and 4842.9 MPa before immersion to 192.0 MPa and 175.8 MPa after 336 h of immersion,respectively.
文摘聚羟基脂肪酸酯(PHA)具有良好的生物降解性、生物相容性和可持续性,在包装、食品和医疗等领域具有广泛的应用前景。因此,亟待对国内外近二十余年来的有关PHA的研究进行总结和梳理,为PHA领域的协同发展提供理论依据。本研究以Web of Science(WOS)核心合集数据库和中国知网(CNKI)全文数据库为数据检索源,借助CiteSpace和VOSviewer文献计量工具,对2000-2023年PHA领域的相关文献进行知识图谱的可视化分析。结果表明,在2000-2023年间,国内外对PHA领域的研究目前处于快速增长阶段,且英文文献的发文量和年增长率均显著高于中文文献。国际对该领域的关注度和研究要早于国内,并且我国在PHA领域的研究对全球贡献较大,但有影响力的研究较为缺乏,亟待进一步提高。关键词聚类和时空突现分析表明,未来的研究热点主要集中在以下3个方面:1)降低PHA生产成本以实现工业化生产;2)关注PHA降解酶的筛选与鉴定,以及PHA降解过程中的微生物群落结构和功能研究;3)PHA的共聚改性、复合改性以及与其他生物材料的功能化改性。
