Phenacoccus solenopsis has been recognized as an aggressively invasive species on cotton plants in different countries.This study was conducted to investigate the effect of green synthesized Cu/Zn-nanoparticles using ...Phenacoccus solenopsis has been recognized as an aggressively invasive species on cotton plants in different countries.This study was conducted to investigate the effect of green synthesized Cu/Zn-nanoparticles using aqueous leaf extract of Prosopis juliflora(mezquite)against P.solenopsis.The scanning electron microscope(SEM)showed bimetallic nanoparticles of Cu/Zn-NPs with spherical shape with varying size of 74.33 nm to 59.46 nm.More than 30%mortality of P.solenopsis was observed with Cu/Zn-nanoparticles(100 ppm)at 96 hours after treatment.Negligible mortality of P.solenopsis was recorded with Cu/Zn solution(100 ppm)and aqueous P.juliflora extracts.The results of the viability test for Cu/Zn-nanoparticles of P.juliflora showed a significant reduction of the cell viability by 50%in insect exposed to Cu/Zn-nanoparticles-P.juliflora.Therefore studies about nanotoxicity of Cu/Zn-NPs of P.juliflora are needed to reveal the mechanism of toxicity this phytonanoparticles in P.solenopsis.展开更多
In present study invasion of Parthenium hysterophorus L. and its impacts on agriculture fields will be done in different cultivated crops in Bilaspur. The present work deals with diversity and distribution of weeds sp...In present study invasion of Parthenium hysterophorus L. and its impacts on agriculture fields will be done in different cultivated crops in Bilaspur. The present work deals with diversity and distribution of weeds species in cultivated fields of Bilaspur C.G. A total number of 28 species under 27 genera and 16 families was distributed in three study sites (Koni, Sakri & Kota) of cultivated fields in Bilaspur C.G. These study sites were located in different altitudinal zones responding different conditions in the this study. The number of species per sites ranged from 13 to 24. In the Sakri, number of species was ranged from 17 to 27, and the relative density of plant species ranged between 0.77 (Heteropogon contortus, Solanum surratense, Vernonia cinneria and Leucas aspera) and 22.92 (Parthenium hysterophorus). In the Kota, number of species was ranged from 14 to 28, and the relative density of plant species ranged between 0.85 (Ageratum conyzoides, Heteropogon contortus, Triticum aestivum) and 29.06 (Zea mays) and 30.91 (Parthenium hysterophorus). In the Agriculture field, number of species was ranged from 15 to 28, and the relative density of plant species ranged between 0.58 (Leucas aspera) and 26.23 (Triticum aestivum). Present work will give the information that weeds are harmful to herbs, crops and medicinal plants. Parthenium weed can suppress and crowd out other weed species, and could form a single dominant population in the invasion area, causing serious threat to plant community biological diversity.展开更多
There has been an increase of community studies that incorporate the use of functional diversity indices. The incorporation of these indices in the analysis of marine communities is recent, however, could contribute w...There has been an increase of community studies that incorporate the use of functional diversity indices. The incorporation of these indices in the analysis of marine communities is recent, however, could contribute with relevant information about the health of those communities. The lagoon of La Paz is a body of water located in La Paz, B.C.S., México. Despite its regional importance, there are not recent studies about its fish communities. Therefore, the aim of the present study was to analyze the temporal and spatial structure of the functional diversity of fish communities associated to soft bottoms, from August 2016 to July 2017, as well as important environmental variables. Functional diversity indices showed significant differences between months. Spatial analysis did not show significant differences perhaps due to low variability of the type of substrate. Temperature showed temporal differences as well. Therefore, temperature may be a limiting environmental variable for many fish species inhabiting coastal lagoons.展开更多
An analysis of the variation of the density and biomass of the fish communities of the lagoon of La Paz, Mexico was carried out from November 2016 to September 2017. A total of 2763 organisms were collected with a tot...An analysis of the variation of the density and biomass of the fish communities of the lagoon of La Paz, Mexico was carried out from November 2016 to September 2017. A total of 2763 organisms were collected with a total biomass of 211,422.93 g in an area of 5022 m<sup>2</sup>, a density and biomass of 0.550 lnd/m<sup>2</sup> and 44.091 g/m<sup>2</sup>. The site with the largest biomass was recorded in Zacatecas (11.179 g/m<sup>2</sup>) located north of the lagoon, while Grand Plaza recorded the lowest biomass (2.732 g/m<sup>2</sup>). Regarding the density, the maximum value was recorded in the site Yate Hundido, located northwest of the lagoon (0.129 lnd/m<sup>2</sup>) and the lowest was Las Palmas (0.036 lnd/m<sup>2</sup>) located north of the lagoon. The most abundant species was Diapterus peruvianus with 683 individuals and a biomass of 37,507.57 g. The physicochemical variables showed two seasons with significant change where we can observe higher temperatures in the summer (average of 27.45<span style="white-space:normal;"><span style="font-family:;" "=""><span style="white-space:nowrap;">°C) and minimum in winter (average of 22.49<span style="white-space:nowrap;">°C). The Shannon-Weaver diversity index showed a difference (p = 0.050) between months, with the highest value recorded in April (H<span style="white-space:normal;"><span style="font-family:;" "="">'<span style="white-space:normal;"><span style="font-family:;" "=""> = 2.133 bits/ind) and the lowest in June (H<span style="white-space:normal;"><span style="font-family:;" "="">'<span style="white-space:normal;"><span style="font-family:;" "=""> = 1.041 bits/ind). The biomass and density values recorded in the lagoon were found to be associated with the spatio-temporal variation of temperature of the lagoon, as well as the resident and transitory species located in the area of study. In addition, the body sizes recorded corresponded to juvenile and young adult individuals.展开更多
In C?te d’Ivoire, ginger (Zingiber officinale Rosc.), generally used to make a drink called “Gnamankoudji”, has become an important source of agricultural income diversification. In order to assess the agromorpholo...In C?te d’Ivoire, ginger (Zingiber officinale Rosc.), generally used to make a drink called “Gnamankoudji”, has become an important source of agricultural income diversification. In order to assess the agromorphological diversity of a ginger collection from different regions of C?te d’Ivoire, a survey collection of accessions was carried out in the different production zones of the country. One hundred and eighty-eight ginger accessions were collected in 15 regions and one autonomous district of C?te d’Ivoire. Analysis of variance revealed that all the variables used in this study discriminated between the ginger accessions collected. Principal component analysis revealed morphological variability of 45.931% for the first two components. Ascending Hierarchical Classification was used to classify these accessions into three groups based on fourteen quantitative characters. These three groups were formed independently of collection areas and are characterized by moderate morphological variability. This variability has been structured into three distinct agromorphological groups, with thallus (rhizome) length and width, finger width, secondary finger length and yield in tons per hectare as distinctive characters. This revealed genetic diversity could be exploited in ginger breeding and improvement programs in C?te d’Ivoire.展开更多
Abnormal levels of plasma lipid have been linked to atherosclerosis, strokes and heart conditions. Variations in high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol levels are considered as ri...Abnormal levels of plasma lipid have been linked to atherosclerosis, strokes and heart conditions. Variations in high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol levels are considered as risk factors for coronary artery disease (CAD). Furthermore, triglycerides are a leading cause of cardiovascular disease. Therefore, measurement of plasma lipid levels is an important mortality predictor. Several factors were associated with irregularity in plasma lipids such as genetic alterations. Recent researches have linked single nucleotides polymorphism (SNP) in ApoA5 gene with these deviations. In this study, we reported the effects of the genetic variant c.553G>T in ApoA5 on the levels of plasma lipids. To explore these effects, a case-control study including 280 male and female subjects (44 of them were assigned as CAD cases while the remaining subjects were categorized as control) was established. All patients in the study were recruited from the western region in KSA. The results have detected minor variations in LDL, HDL and cholesterol levels between CAD patients carrying T allele and CAD patients carrying the WT allele. However, there were no significant effects due to these variations. TG levels in the wild type carriers reached up to 291 mg/dl while T allele carriers, the cases, presented lower levels of TG (170 mg/dl and 71 mg/dl). Although, T allele showed no effects on plasma lipids with the exception of TG levels. We suggest by this study that T allele in this SNP might be considered as a valuable tool in the diagnosis of CAD.展开更多
在“碳达峰”“碳中和”背景下,碳足迹是生命周期评价(life cycle assessment,LCA)体系中最受关注的指标。LCA背景数据库是开展碳足迹计算的必要前提,中国数据的缺失对全球碳足迹计算影响巨大。基于此,首次提出了建设中国钢铁行业本土化...在“碳达峰”“碳中和”背景下,碳足迹是生命周期评价(life cycle assessment,LCA)体系中最受关注的指标。LCA背景数据库是开展碳足迹计算的必要前提,中国数据的缺失对全球碳足迹计算影响巨大。基于此,首次提出了建设中国钢铁行业本土化LCA背景数据库的方法。背景数据库采用的LCA方法学体系是建设数据库的核心,通过分析不同方法计算钢铁产品碳足迹结果的差异性,提出了分别采用归因法、归果法和EN15804标准建设中国钢铁行业背景数据库,以适用不同应用场景。采用欧盟提出的ILCD(international reference life cycle data system)数据库格式,对数据全过程的处理进行记录和审核,确保数据质量,保证了背景数据库的透明可追溯和国际交互性。依据所提出的方法开发了钢铁行业生命周期背景数据库HiQLCD,采用3种方法各生成1套数据,每套数据包含5815条数据集,共计17445条数据集。对比了采用本土数据库和国外某数据库计算铁水碳足迹的结果,结果显示本土数据库更符合中国产品生产工艺特点,技术代表性、地理代表性、时间代表性、准确性等反映背景数据质量的指标都有显著提升,计算结果更准确,更能反映实际情况,以更真实的数据科学地支撑企业算碳、减碳。同时,规则的透明性为实现碳足迹计算结果的国际互认奠定了基础。后续研究将致力于持续拓展钢铁产品数据库的覆盖范围,高频次迭代,逐步提升国内高质量数据在背景数据中的比例,同时开展复杂度更高的供应链数据库建设的研究。展开更多
The rich resources and unique environment of the Moon make it an ideal location for human expansion and the utilization of extraterrestrial resources.Oxygen,crucial for supporting human life on the Moon,can be extract...The rich resources and unique environment of the Moon make it an ideal location for human expansion and the utilization of extraterrestrial resources.Oxygen,crucial for supporting human life on the Moon,can be extracted from lunar regolith,which is highly rich in oxygen and contains polymetallic oxides.This oxygen and metal extraction can be achieved using existing metallurgical techniques.Furthermore,the ample reserves of water ice on the Moon offer another means for oxygen production.This paper offers a detailed overview of the leading technologies for achieving oxygen production on the Moon,drawing from an analysis of lunar resources and environmental conditions.It delves into the principles,processes,advantages,and drawbacks of water-ice electrolysis,two-step oxygen production from lunar regolith,and one-step oxygen production from lunar regolith.The two-step methods involve hydrogen reduction,carbothermal reduction,and hydrometallurgy,while the one-step methods encompass fluorination/chlorination,high-temperature decomposition,molten salt electrolysis,and molten regolith electrolysis(MOE).Following a thorough comparison of raw materials,equipment,technology,and economic viability,MOE is identified as the most promising approach for future in-situ oxygen production on the Moon.Considering the corrosion characteristics of molten lunar regolith at high temperatures,along with the Moon's low-gravity environment,the development of inexpensive and stable inert anodes and electrolysis devices that can easily collect oxygen is critical for promoting MOE technology on the Moon.This review significantly contributes to our understanding of in-situ oxygen production technologies on the Moon and supports upcoming lunar exploration initiatives.展开更多
Dibromoethane is a widespread,persistent organic pollutant.Biochars are known mediators of reductive dehalogenation by layered Fe^(Ⅱ)-Fe^(Ⅲ)hydroxides(green rust),which can reduce 1,2-dibromoethane to innocuous brom...Dibromoethane is a widespread,persistent organic pollutant.Biochars are known mediators of reductive dehalogenation by layered Fe^(Ⅱ)-Fe^(Ⅲ)hydroxides(green rust),which can reduce 1,2-dibromoethane to innocuous bromide and ethylene.However,the critical characteristics that determine mediator functionality are lesser known.Fifteen biochar substrates were pyrolyzed at 600℃and 800℃,characterized by elemental analysis,X-ray photo spectrometry C and N surface speciation,X-ray powder diffraction,specific surface area analysis,and tested for mediation of reductive debromination of 1,2-dibromoethane by a green rust reductant under anoxic conditions.A statistical analysis was performed to determine the biochar properties,critical for debromination kinetics and total debromination extent.It was shown that selected plant based biochars can mediate debromination of 1,2-dibromoethane,that the highest first order rate constant was 0.082/hr,and the highest debromination extent was 27%in reactivity experiments with 0.1μmol(20μmol/L)1,2-dibromoethane,≈22 mmol/L Fe^(Ⅱ)GR,and 0.12 g/L soybean meal biochar(7 days).Contents of Ni,Zn,N,and P,and the relative contribution of quinone surface functional groups were significantly(p<0.05)positively correlated with 1,2-dibromoethane debromination,while adsorption,specific surface area,and the relative contribution of pyridinic N oxide surface groups were significantly negatively correlated with debromination.展开更多
This paper examines the effect of Fe addition on the microstructure characterized by scanning electron microscopy/electron backscattered diffraction,neutron diffraction,and synchrotron X-ray tomography and the mechani...This paper examines the effect of Fe addition on the microstructure characterized by scanning electron microscopy/electron backscattered diffraction,neutron diffraction,and synchrotron X-ray tomography and the mechanical properties of Al-Mg-Mn-Fe-Cu alloys.The findings reveal that the microstructures of the alloys consisted of an Al matrix,Al_(6)(FeMn),and Al_(2)CuMg phase particles.The addition of Fe significantly increased the yield strength(YS),and ultimate tensile strength(UTS)of the alloys,while reducing elongation.The transformation of the 3D morphology of the Al_(6)(FeMn)phase from separated and fine particles with Chinese-script morphology to interconnected rod-like structure as Fe content increased from 0.1%to 0.8%.This strengthening effect was attributed to the slip lines being blocked at the vicinity of the inter-connected Fe-rich phase,leading to grain rotation and dislocation density increment around the Fe-rich phase,ultimately improving the strength of the alloys.However,the Fe-rich phases and Al_(2)CuMg phases were found to be prone to cracking under tensile stress,resulting in decreased elongation of the alloys.This study provides a potential application in the design and manufacturing of new non-heat-treatable Al alloys for the automotive industry.展开更多
文摘Phenacoccus solenopsis has been recognized as an aggressively invasive species on cotton plants in different countries.This study was conducted to investigate the effect of green synthesized Cu/Zn-nanoparticles using aqueous leaf extract of Prosopis juliflora(mezquite)against P.solenopsis.The scanning electron microscope(SEM)showed bimetallic nanoparticles of Cu/Zn-NPs with spherical shape with varying size of 74.33 nm to 59.46 nm.More than 30%mortality of P.solenopsis was observed with Cu/Zn-nanoparticles(100 ppm)at 96 hours after treatment.Negligible mortality of P.solenopsis was recorded with Cu/Zn solution(100 ppm)and aqueous P.juliflora extracts.The results of the viability test for Cu/Zn-nanoparticles of P.juliflora showed a significant reduction of the cell viability by 50%in insect exposed to Cu/Zn-nanoparticles-P.juliflora.Therefore studies about nanotoxicity of Cu/Zn-NPs of P.juliflora are needed to reveal the mechanism of toxicity this phytonanoparticles in P.solenopsis.
文摘In present study invasion of Parthenium hysterophorus L. and its impacts on agriculture fields will be done in different cultivated crops in Bilaspur. The present work deals with diversity and distribution of weeds species in cultivated fields of Bilaspur C.G. A total number of 28 species under 27 genera and 16 families was distributed in three study sites (Koni, Sakri & Kota) of cultivated fields in Bilaspur C.G. These study sites were located in different altitudinal zones responding different conditions in the this study. The number of species per sites ranged from 13 to 24. In the Sakri, number of species was ranged from 17 to 27, and the relative density of plant species ranged between 0.77 (Heteropogon contortus, Solanum surratense, Vernonia cinneria and Leucas aspera) and 22.92 (Parthenium hysterophorus). In the Kota, number of species was ranged from 14 to 28, and the relative density of plant species ranged between 0.85 (Ageratum conyzoides, Heteropogon contortus, Triticum aestivum) and 29.06 (Zea mays) and 30.91 (Parthenium hysterophorus). In the Agriculture field, number of species was ranged from 15 to 28, and the relative density of plant species ranged between 0.58 (Leucas aspera) and 26.23 (Triticum aestivum). Present work will give the information that weeds are harmful to herbs, crops and medicinal plants. Parthenium weed can suppress and crowd out other weed species, and could form a single dominant population in the invasion area, causing serious threat to plant community biological diversity.
文摘There has been an increase of community studies that incorporate the use of functional diversity indices. The incorporation of these indices in the analysis of marine communities is recent, however, could contribute with relevant information about the health of those communities. The lagoon of La Paz is a body of water located in La Paz, B.C.S., México. Despite its regional importance, there are not recent studies about its fish communities. Therefore, the aim of the present study was to analyze the temporal and spatial structure of the functional diversity of fish communities associated to soft bottoms, from August 2016 to July 2017, as well as important environmental variables. Functional diversity indices showed significant differences between months. Spatial analysis did not show significant differences perhaps due to low variability of the type of substrate. Temperature showed temporal differences as well. Therefore, temperature may be a limiting environmental variable for many fish species inhabiting coastal lagoons.
文摘An analysis of the variation of the density and biomass of the fish communities of the lagoon of La Paz, Mexico was carried out from November 2016 to September 2017. A total of 2763 organisms were collected with a total biomass of 211,422.93 g in an area of 5022 m<sup>2</sup>, a density and biomass of 0.550 lnd/m<sup>2</sup> and 44.091 g/m<sup>2</sup>. The site with the largest biomass was recorded in Zacatecas (11.179 g/m<sup>2</sup>) located north of the lagoon, while Grand Plaza recorded the lowest biomass (2.732 g/m<sup>2</sup>). Regarding the density, the maximum value was recorded in the site Yate Hundido, located northwest of the lagoon (0.129 lnd/m<sup>2</sup>) and the lowest was Las Palmas (0.036 lnd/m<sup>2</sup>) located north of the lagoon. The most abundant species was Diapterus peruvianus with 683 individuals and a biomass of 37,507.57 g. The physicochemical variables showed two seasons with significant change where we can observe higher temperatures in the summer (average of 27.45<span style="white-space:normal;"><span style="font-family:;" "=""><span style="white-space:nowrap;">°C) and minimum in winter (average of 22.49<span style="white-space:nowrap;">°C). The Shannon-Weaver diversity index showed a difference (p = 0.050) between months, with the highest value recorded in April (H<span style="white-space:normal;"><span style="font-family:;" "="">'<span style="white-space:normal;"><span style="font-family:;" "=""> = 2.133 bits/ind) and the lowest in June (H<span style="white-space:normal;"><span style="font-family:;" "="">'<span style="white-space:normal;"><span style="font-family:;" "=""> = 1.041 bits/ind). The biomass and density values recorded in the lagoon were found to be associated with the spatio-temporal variation of temperature of the lagoon, as well as the resident and transitory species located in the area of study. In addition, the body sizes recorded corresponded to juvenile and young adult individuals.
文摘In C?te d’Ivoire, ginger (Zingiber officinale Rosc.), generally used to make a drink called “Gnamankoudji”, has become an important source of agricultural income diversification. In order to assess the agromorphological diversity of a ginger collection from different regions of C?te d’Ivoire, a survey collection of accessions was carried out in the different production zones of the country. One hundred and eighty-eight ginger accessions were collected in 15 regions and one autonomous district of C?te d’Ivoire. Analysis of variance revealed that all the variables used in this study discriminated between the ginger accessions collected. Principal component analysis revealed morphological variability of 45.931% for the first two components. Ascending Hierarchical Classification was used to classify these accessions into three groups based on fourteen quantitative characters. These three groups were formed independently of collection areas and are characterized by moderate morphological variability. This variability has been structured into three distinct agromorphological groups, with thallus (rhizome) length and width, finger width, secondary finger length and yield in tons per hectare as distinctive characters. This revealed genetic diversity could be exploited in ginger breeding and improvement programs in C?te d’Ivoire.
文摘Abnormal levels of plasma lipid have been linked to atherosclerosis, strokes and heart conditions. Variations in high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol levels are considered as risk factors for coronary artery disease (CAD). Furthermore, triglycerides are a leading cause of cardiovascular disease. Therefore, measurement of plasma lipid levels is an important mortality predictor. Several factors were associated with irregularity in plasma lipids such as genetic alterations. Recent researches have linked single nucleotides polymorphism (SNP) in ApoA5 gene with these deviations. In this study, we reported the effects of the genetic variant c.553G>T in ApoA5 on the levels of plasma lipids. To explore these effects, a case-control study including 280 male and female subjects (44 of them were assigned as CAD cases while the remaining subjects were categorized as control) was established. All patients in the study were recruited from the western region in KSA. The results have detected minor variations in LDL, HDL and cholesterol levels between CAD patients carrying T allele and CAD patients carrying the WT allele. However, there were no significant effects due to these variations. TG levels in the wild type carriers reached up to 291 mg/dl while T allele carriers, the cases, presented lower levels of TG (170 mg/dl and 71 mg/dl). Although, T allele showed no effects on plasma lipids with the exception of TG levels. We suggest by this study that T allele in this SNP might be considered as a valuable tool in the diagnosis of CAD.
文摘在“碳达峰”“碳中和”背景下,碳足迹是生命周期评价(life cycle assessment,LCA)体系中最受关注的指标。LCA背景数据库是开展碳足迹计算的必要前提,中国数据的缺失对全球碳足迹计算影响巨大。基于此,首次提出了建设中国钢铁行业本土化LCA背景数据库的方法。背景数据库采用的LCA方法学体系是建设数据库的核心,通过分析不同方法计算钢铁产品碳足迹结果的差异性,提出了分别采用归因法、归果法和EN15804标准建设中国钢铁行业背景数据库,以适用不同应用场景。采用欧盟提出的ILCD(international reference life cycle data system)数据库格式,对数据全过程的处理进行记录和审核,确保数据质量,保证了背景数据库的透明可追溯和国际交互性。依据所提出的方法开发了钢铁行业生命周期背景数据库HiQLCD,采用3种方法各生成1套数据,每套数据包含5815条数据集,共计17445条数据集。对比了采用本土数据库和国外某数据库计算铁水碳足迹的结果,结果显示本土数据库更符合中国产品生产工艺特点,技术代表性、地理代表性、时间代表性、准确性等反映背景数据质量的指标都有显著提升,计算结果更准确,更能反映实际情况,以更真实的数据科学地支撑企业算碳、减碳。同时,规则的透明性为实现碳足迹计算结果的国际互认奠定了基础。后续研究将致力于持续拓展钢铁产品数据库的覆盖范围,高频次迭代,逐步提升国内高质量数据在背景数据中的比例,同时开展复杂度更高的供应链数据库建设的研究。
基金financially supported by the National Natural Science Foundation of China(Nos.52404328,52274412,and 52374418)the China Postdoctoral Science Foundation(No.2024M753248)。
文摘The rich resources and unique environment of the Moon make it an ideal location for human expansion and the utilization of extraterrestrial resources.Oxygen,crucial for supporting human life on the Moon,can be extracted from lunar regolith,which is highly rich in oxygen and contains polymetallic oxides.This oxygen and metal extraction can be achieved using existing metallurgical techniques.Furthermore,the ample reserves of water ice on the Moon offer another means for oxygen production.This paper offers a detailed overview of the leading technologies for achieving oxygen production on the Moon,drawing from an analysis of lunar resources and environmental conditions.It delves into the principles,processes,advantages,and drawbacks of water-ice electrolysis,two-step oxygen production from lunar regolith,and one-step oxygen production from lunar regolith.The two-step methods involve hydrogen reduction,carbothermal reduction,and hydrometallurgy,while the one-step methods encompass fluorination/chlorination,high-temperature decomposition,molten salt electrolysis,and molten regolith electrolysis(MOE).Following a thorough comparison of raw materials,equipment,technology,and economic viability,MOE is identified as the most promising approach for future in-situ oxygen production on the Moon.Considering the corrosion characteristics of molten lunar regolith at high temperatures,along with the Moon's low-gravity environment,the development of inexpensive and stable inert anodes and electrolysis devices that can easily collect oxygen is critical for promoting MOE technology on the Moon.This review significantly contributes to our understanding of in-situ oxygen production technologies on the Moon and supports upcoming lunar exploration initiatives.
文摘Dibromoethane is a widespread,persistent organic pollutant.Biochars are known mediators of reductive dehalogenation by layered Fe^(Ⅱ)-Fe^(Ⅲ)hydroxides(green rust),which can reduce 1,2-dibromoethane to innocuous bromide and ethylene.However,the critical characteristics that determine mediator functionality are lesser known.Fifteen biochar substrates were pyrolyzed at 600℃and 800℃,characterized by elemental analysis,X-ray photo spectrometry C and N surface speciation,X-ray powder diffraction,specific surface area analysis,and tested for mediation of reductive debromination of 1,2-dibromoethane by a green rust reductant under anoxic conditions.A statistical analysis was performed to determine the biochar properties,critical for debromination kinetics and total debromination extent.It was shown that selected plant based biochars can mediate debromination of 1,2-dibromoethane,that the highest first order rate constant was 0.082/hr,and the highest debromination extent was 27%in reactivity experiments with 0.1μmol(20μmol/L)1,2-dibromoethane,≈22 mmol/L Fe^(Ⅱ)GR,and 0.12 g/L soybean meal biochar(7 days).Contents of Ni,Zn,N,and P,and the relative contribution of quinone surface functional groups were significantly(p<0.05)positively correlated with 1,2-dibromoethane debromination,while adsorption,specific surface area,and the relative contribution of pyridinic N oxide surface groups were significantly negatively correlated with debromination.
基金support from the Natural Science Foundation of China(Nos.52104373,52074131,and 51974092)the Basic and Applied Basic Foundation of Guangdong Province(No.2020B1515120065)。
文摘This paper examines the effect of Fe addition on the microstructure characterized by scanning electron microscopy/electron backscattered diffraction,neutron diffraction,and synchrotron X-ray tomography and the mechanical properties of Al-Mg-Mn-Fe-Cu alloys.The findings reveal that the microstructures of the alloys consisted of an Al matrix,Al_(6)(FeMn),and Al_(2)CuMg phase particles.The addition of Fe significantly increased the yield strength(YS),and ultimate tensile strength(UTS)of the alloys,while reducing elongation.The transformation of the 3D morphology of the Al_(6)(FeMn)phase from separated and fine particles with Chinese-script morphology to interconnected rod-like structure as Fe content increased from 0.1%to 0.8%.This strengthening effect was attributed to the slip lines being blocked at the vicinity of the inter-connected Fe-rich phase,leading to grain rotation and dislocation density increment around the Fe-rich phase,ultimately improving the strength of the alloys.However,the Fe-rich phases and Al_(2)CuMg phases were found to be prone to cracking under tensile stress,resulting in decreased elongation of the alloys.This study provides a potential application in the design and manufacturing of new non-heat-treatable Al alloys for the automotive industry.
