Heavy metal pollution has become a pervasive environmental issue affecting numerous regions worldwide.Recently,there has been significant attention given to the application of nano-enabled technologies with the purpos...Heavy metal pollution has become a pervasive environmental issue affecting numerous regions worldwide.Recently,there has been significant attention given to the application of nano-enabled technologies with the purpose of enhancing plant development and alleviating heavy metal stress.This study aimed to illustrate the potential of zinc oxide nanoparticles(ZnO-NPs)to enhance the morphological traits of D.huoshenense exposed to cadmium(Cd)stress.The chemical structure and elemental composition of the ZnO-NPs were characterised by a series of analytical methods,including X-ray diffraction,UV-Vis spectrometry,XPS,andTEM.Plant samples usedwere collected at 0,5,and 15 days in order to assess physiological and biochemical parameters under different Cd treatments.ZnONPs administered in pot experiments have been shown to enhance plant proliferation through the modulation of Cd enrichment levels.The results revealed that ZnO-NPs enhanced plant growth by increasing soluble sugars and proline levels,enhancing activities of antioxidant enzymes(SOD,POD,CAT,APX)and reducing electrolyte leakage(EL)and malondialdehyde(MDA)content.Furthermore,ZnO-NPs enhanced the net photosynthetic rate,transpiration,stomatal conductance,and chlorophyll content in leaves subjected to Cd stress at the 10-day sampling stage.Exogenous ZnO-NPs significantly elevated the expression of genes associated with flavonoid biosynthesis,potentially facilitating the accumulation of medicinal compounds to mitigate Cd stress.Taken together,these findings provide a novel perspective on the strategies employed by medicinal plants in response to Cd.展开更多
The composite oxides xAg/Co_（0.93）Ce_（0.07）（x=Ag/（Co＋Ce） molar ratio）,intended for use as high performance catalytic materials,were successfully prepared via citric acid complexation.The effects of silver on ...The composite oxides xAg/Co_（0.93）Ce_（0.07）（x=Ag/（Co＋Ce） molar ratio）,intended for use as high performance catalytic materials,were successfully prepared via citric acid complexation.The effects of silver on the performance of these substances during soot combustion were subsequently investigated.Under O_2,the 0.3Ag/Co_（0.93）Ce_（0.07） catalyst resulted in the lowest ignition temperature,T_（10）,of197 ℃,while the minimum light-off temperature was obtained from both 0.2Ag/Co_（0.93）Ce_（0.07） and0.3Ag/Co_（0.93）Ce_（0.07） in the NO_x atmosphere.These materials were also characterized by various techniques,including H_2,soot and NO_x temperature programmed reduction,X-ray diffraction,and electron paramagnetic resonance,Raman,X-ray photoelectron,and Fourier transform infrared spectroscopic analyses.The results demonstrated that silver significantly alters the catalytic behavior under both O_2 and NO_x,even though the lattice structure of the mixed oxide is not affected.Surface silver oxides generated under the O_2 atmosphere favor soot combustion by participating in the redox cycles between soot and the silver oxide,whereas the AgNO_3 that forms in a NO_x-rich atmosphere facilitates soot abatement at a lower temperature.The inferior activity of AgNO_3 relative to that of Ag_2O results in the different catalytic performance in the presence of NO_x or O_2.展开更多
This study describes a new effective adsorbent for cadmium removal from aqueous solution synthesized by coating a shellac layer, a natural biodegradable and renewable resin with abundant hydroxyl and carboxylic groups...This study describes a new effective adsorbent for cadmium removal from aqueous solution synthesized by coating a shellac layer, a natural biodegradable and renewable resin with abundant hydroxyl and carboxylic groups, on the surface of iron oxide magnetic nanoparticles. Transmission Electron Microscopy （TEM） imaging showed shellac-coated magnetic nanoparticle （SCMN） adsorbents had a core-shell structure with a core of 20 nm and shell of 5 nm. Fourier Transform Infrared Spectroscopic analysis suggested the occurrence of reaction between carboxyl groups on the SCMN adsorbent surface and cadmium ions in aqueous solution. Kinetic data were well described by pseudo second-order model and adsorption isotherms were fitted with both Langmuir and Freundlich models with maximum adsorption capacity of 18.80 mg]g. SCMN adsorbents provided a favorable adsorption capacity under high salinity conditions, and cadmium could easily be desorbed using mild organic acid solutions at low concentration.展开更多
The effect of calcium chloride （CaCl2） on rice seedling growth under cadmium chloride （CdCl2） stress, as well as the possible role of endogenous nitric oxide （NO） in this process, was studied. The growth of rice...The effect of calcium chloride （CaCl2） on rice seedling growth under cadmium chloride （CdCl2） stress, as well as the possible role of endogenous nitric oxide （NO） in this process, was studied. The growth of rice seedlings was seriously inhibited by CdCl2, and the inhibition was significantly mitigated by CaCl2. However, hemoglobin （Hb） and 2-（4-carboxyphenyl）-4, 4,5,5-tetramethylimidazoline- l-oxyl-3-oxide （cPTIO） weakened the promotion effect of CaCl2. The results of NO fluorescence localization suggest that growth accelerated by CaCl2 might be associated with elevated NO levels. The content of Cd, protein thiols （PBT）, and nonprotein thiols （NPT） in cell walls, cell organelles, and soluble fractions, respectively, of rice seedlings decreased considerably in the presence of CaCl2, whereas the content of pectin, hemicellulose 1 （HC1）, and hemicellulose 2 （HC2） increased significantly. Elimination of endogenous NO in Cd＋Ca treatment could promote the transportation of Cd2＋ to cell organelles and soluble fractions and increase the content of NPT and PBT in leaves. In addition, transportation of Cd2＋ to cell organelles and soluble fractions was retarded in roots, the content of NPT increased, and the content of PBT decreased. With elimination of endogenous NO in Cd＋Ca treatment, the content of pectin, HC1, and HC2 decreased significantly. Thus, Ca may alleviate Cd toxicity via endogenous NO with variation in the levels of NPT, PBT, and matrix polysaccharides.展开更多
Silver catalyst has been extensively investigated for photocatalytic and electrochemical CO_(2)reduction.However,its high activity for selective hydrogenation of CO_(2)to methanol has not been confirmed.Here,the feasi...Silver catalyst has been extensively investigated for photocatalytic and electrochemical CO_(2)reduction.However,its high activity for selective hydrogenation of CO_(2)to methanol has not been confirmed.Here,the feasibility of the indium oxide supported silver catalyst was investigated for CO_(2)hydrogenation to methanol by the density functional theoretical(DFT)study and then by the experimental investigation.The DFT study shows there exists an intense Ag-In_(2)O_(3)interaction,which causes silver to be positively charged.The positively charged Ag species changes the electronic structure of the metal,facilitates the formation of the Ag-In_(2)O_(3)interfacial site for activation and dissociation of carbon dioxide.The promoted CO_(2)dissociation leads to the enhanced methanol synthesis via the CO hydrogenation route as CO_(2)^(*)→CO^(*)→HCO^(*)→H_(2)CO^(*)→H_(3)CO^(*)→H_(3)COH^(*).The Ag/In_(2)O_(3)catalyst was then prepared using the deposition-precipitation method.The experimental study confirms the theoretical prediction.The methanol selectivity of CO_(2)hydrogenation on Ag/In_(2)O_(3)reaches 100.0%at reaction temperature of 200℃.It remains more than 70.0%between 200 and 275℃.At 300℃and 5 MPa,the methanol selectivity still keeps 58.2%with a CO_(2)conversion of 13.6%and a space-time yield(STY)of methanol of 0.453 g_(methanol)g_(cat)^(-1)h^(-1),which is the highest methanol STY ever reported for silver catalyst.The catalyst characterization confirms the intense Ag-In_(2)O_(3)interaction as well,which causes high Ag dispersion,increases and stabilizes the oxygen vacancies and creates the active Ag-In_(2)O_(3)interfacial site for the enhanced CO_(2)hydrogenation to methanol.展开更多
Silver tin oxide composite powders were synthesized by the hydrothermal method with a silver ammine solution and a Na2SnO3 solution as raw materials. H2C2O4 was used as the co-precipitator of silver ions and tin ions....Silver tin oxide composite powders were synthesized by the hydrothermal method with a silver ammine solution and a Na2SnO3 solution as raw materials. H2C2O4 was used as the co-precipitator of silver ions and tin ions. The co-precipitation conditions were investigated. The results show that the co-precipitate of Ag2C2O4 and Sn（OH）4 is available when the pH value of the solution is 4.27-8.36. Using the obtained precipitate as precursor,the reduction of Ag＋ and the crystallization of tin oxide were carried out simultaneously by the hydrothermal method and silver tin oxide composite powders were obtained. The composite powders were characterized by X-ray diffraction （XRD） analysis,scanning electron microscope （SEM）,and energy spectrum analysis. The results show that the silver tin oxide composite powders are small with a diameter of about 2 μm and with homogeneous distribution of tin.展开更多
A new calcium-modified and starch-stabilized ferromanganese binary oxide (Ca-SFMBO)sorbent was fabricated with different Ca concentrations for the adsorption of arsenic (As)and cadmium (Cd) in water.The maximum As(Ⅲ)...A new calcium-modified and starch-stabilized ferromanganese binary oxide (Ca-SFMBO)sorbent was fabricated with different Ca concentrations for the adsorption of arsenic (As)and cadmium (Cd) in water.The maximum As(Ⅲ) and Cd(Ⅱ) adsorption capacities of 1%CaSFMBO were 156.25 mg/g and 107.53 mg/g respectively in single-adsorption systems.The adsorption of As and Cd by the Ca-SFMBO sorbent was pH-dependent at values from 1 to 7,with an optimal adsorption pH of 6.In the dual-adsorbate system,the presence of Cd(Ⅱ) at low concentrations enhanced As(Ⅲ) adsorption by 33.3%,while the adsorption of As(Ⅲ) was inhibited with the increase of Cd(Ⅱ) concentration.Moreover,the addition of As(Ⅲ) increased the adsorption capacity for Cd(Ⅱ) up to two-fold.Through analysis by X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR),it was inferred that the mechanism for the co-adsorption of Cd(Ⅱ) and As(Ⅲ) included both competitive and synergistic effects,which resulted from the formation of ternary complexes.The results indicate that the Ca-SFMBO material developed here could be used for the simultaneous removal of As(Ⅲ) and Cd(Ⅱ) from contaminated water.展开更多
The mechanical decomposing and mechanochemical reductions of silver oxide for preparation of nanocrystalline silver powders by high planetary ball mill was investigated. XRD and HRSEM techniques were used to character...The mechanical decomposing and mechanochemical reductions of silver oxide for preparation of nanocrystalline silver powders by high planetary ball mill was investigated. XRD and HRSEM techniques were used to characterize the structural evolution and morphological changes of products. The results show that the nanostructured silver with an average crystallite size of 14 nm and internal strain of 0.75% is synthesized by mechanical decomposing of Ag2O after 95 h milling. While, the product of mechanochemical reduction of silver oxide using graphite after 22 h milling is nanostructured silver with an average crystallite size of 28 nm and internal strain of 0.44%.展开更多
The rapid industrial growth and increasing population have led to significant pollution and deterioration of the natural atmospheric environment.Major atmospheric pollutants include NO_(2)and CO_(2).Hence,it is impera...The rapid industrial growth and increasing population have led to significant pollution and deterioration of the natural atmospheric environment.Major atmospheric pollutants include NO_(2)and CO_(2).Hence,it is imperative to develop NO_(2)and CO_(2)sensors for ambient conditions,that can be used in indoor air quality monitoring,breath analysis,food spoilage detection,etc.In the present study,two thin film nanocomposite(nickel oxide-graphene and nickel oxide-silver nanowires)gas sensors are fabricated using direct ink writing.The nano-composites are investigated for their structural,optical,and electrical properties.Later the nano-composite is deposited on the interdigitated electrode(IDE)pattern to form NO_(2)and CO_(2)sensors.The deposited films are then exposed to NO_(2)and CO_(2)gases separately and their response and recovery times are determined using a custom-built gas sensing setup.Nickel oxide-graphene provides a good response time and recovery time of 10 and 9 s,respectively for NO_(2),due to the higher electron affinity of graphene towards NO_(2).Nickel oxide-silver nanowire nano-composite is suited for CO_(2)gas because silver is an excellent electrocatalyst for CO_(2)by giving response and recovery times of 11 s each.This is the first report showcasing NiO nano-composites for NO_(2)and CO_(2)sensing at room temperature.展开更多
Nitric oxide （NO） is a gaseous signaling molecule in plants that plays a key role in mediating a wide range of physiological processes and responses to biotic and abiotic stresses. The present study was conducted to...Nitric oxide （NO） is a gaseous signaling molecule in plants that plays a key role in mediating a wide range of physiological processes and responses to biotic and abiotic stresses. The present study was conducted to investigate the effects of the exogenous application of sodium nitroprusside （SNP）, an NO donor, on cadmium （Cd）-induced oxidative stress and Cd uptake in rice plants. Rice plants were exposed to Cd stress （0.2 mmol L^-1 CdC12） and different concentrations of SNP （0.05, 0.1, 0.2, and 0.4 mmol L^-1）. A SNP concentration of 0.1 mmol L^-1 （SNP 10） significantly reduced the Cd-induced decrease in shoot and root dry weights and leaf chlorophyll concentrations. The addition of NO also reduced the malondialdehyde （MDA）, hydrogen peroxide （H202） and ascorbic acid （ASA） concentrations. However, the reduction in glutathione （GSH） concentration was inhibited by NO treatment. Moreover, NO prevented the Cd-induced increase in antioxidative enzyme activity. The amount of Cd accumulation in rice plants was also influenced by the addition of NO. The NO supplied by the SNP enhanced the Cd tolerance of the rice by increasing the Cd uptake by the roots and decreasing the Cd accumulation by the shoots. However, the application of potassium ferrocyanide （Cd＋Fe） or sodium nitrate and nitrite （Cd＋N） （without NO release）, did not exhibit the effects of the SNP. Furthermore, the effects of the SNP were reversed by the addition of hemoglobin （an NO scavenger）. Our results suggested that exogenous NO was involved in the resistance of rice to Cd-toxicity.展开更多
Natural surface coatings collected from natural substances （NSCsNS） were employed to study the roles of the main chemical components （iron oxides, manganese oxides, and other components） in controlling the adsorpt...Natural surface coatings collected from natural substances （NSCsNS） were employed to study the roles of the main chemical components （iron oxides, manganese oxides, and other components） in controlling the adsorption of lead（Pb） and cadmium（Cd） in aquatic environments. The selective chemical extraction followed by the adsorption of Pb and Cd experiments and statistical analysis, were used to investigate the adsorption property of each component. Hydroxylamine hydrochloride was used to remove manganese oxides selectively, and sodium dithionite was used to extract iron oxides and manganese oxides. The result indicated that iron oxides and manganese oxides played an important role in the adsorption of Pb and Cd on NSCsNS, and the relative contribution was about two-thirds. The contribution of manganese oxides was the greatest, with a lesser role indicated for other components. The adsorption ability of manganese oxides for Pb and Cd was greater than that of iron oxides or other components for Pb and Cd. The Pb adsorption observed in each component was greater than Cd adsorption.展开更多
In this paper, silver nanoparticles （AgNPs） and AgNPs/reduced graphene oxide （RGO） nanocomposites were prepared using lemon juice under microwave irradiation （MWI） and UV light irradiation. AgNPs with face-cente...In this paper, silver nanoparticles （AgNPs） and AgNPs/reduced graphene oxide （RGO） nanocomposites were prepared using lemon juice under microwave irradiation （MWI） and UV light irradiation. AgNPs with face-centered cubic structure RGO peaks were observed by X-ray diffraction. The UV-Vis spectrum showed modifications in the absorption peaks of the AgNPs with the concentration of the precursor solution and irradiation time, and the optimized condition was obtained for 20 min MWI and 60 s of UV light. Raman analysis confirmed the presence of RGO as D and G bands in the spectrum. Transmission electron microscopy analyses confirmed that the AgNPs of size ranging from 3 to 8 nm were anchored onto the RGO sheets. The antibacterial properties of the AgNPs/RGO nanocomposites were investigated using gram-negative bacteria. The results revealed that AgNPs/RGO nanocomposites consisting of approximately 5 wt% AgNPs can achieve antibacterial performance similar to that of neat AgNPS. This method can be useful for the applications of AgNPs-based nanocomposites, where minute amount of silver will be utilized.展开更多
A series of acyls （Ac, Bz and Ts） were introduced regioselectively to the 2-hydroxyl in methyl and ally 3-O-benzyl-α-L-rhamnopyranosides mediated by silver（I） oxide in the presence of a catalytic amount of potass...A series of acyls （Ac, Bz and Ts） were introduced regioselectively to the 2-hydroxyl in methyl and ally 3-O-benzyl-α-L-rhamnopyranosides mediated by silver（I） oxide in the presence of a catalytic amount of potassium iodide in 56-78% yields.展开更多
Thermodynamic analysis of the possibility of silver nanocrystalline preparation by high energy milling silver oxide was investigated. The molar Gibbs free energy function of mechanically activated samples was calculat...Thermodynamic analysis of the possibility of silver nanocrystalline preparation by high energy milling silver oxide was investigated. The molar Gibbs free energy function of mechanically activated samples was calculated from the structural defects such as amorphization, dislocation and surface energy. According to the molar Gibbs free energy function, the equilibrium temperature of mechanical reduction of silver oxide milled for 21 h was estimated at about 304 K. Consequently, at this temperature silver oxide cannot be stable and will transform to silver during the milling.展开更多
We fabricated flexible transparent conductive films composed of silver nanowires(AgNWs)and reduced graphene oxide(rGO)as hybrid transparent electrode and mixed cellulose eater(MCE)as substrate by a vacuum-filtrating m...We fabricated flexible transparent conductive films composed of silver nanowires(AgNWs)and reduced graphene oxide(rGO)as hybrid transparent electrode and mixed cellulose eater(MCE)as substrate by a vacuum-filtrating method.Effect of rGO on the electrical,optical and mechanical properties of the flexible transparent films were studied.The results show that with the increase of rGO deposition density,the optical transmission at 550 nm has a little decrease,while the sheet resistance(Rs)gradually decreases.Tape tests up to 200 cycles and bending fatigue tests up to 200 cycles were performed by monitoring the in-situ resistance change.The film sustains excellent reliability of the AgNWs/rGO hybrid conductive networks,where the fractional resistance change is little overt increase after tape tests and less than 3%after bending test.The exc ellent mechanical properties of the AgNWs/rGO film can be attributed to the burying of the AgNWs and RGO film at the surface of mixed cellulose eaters(MCEs).展开更多
New flame-retardant polyimide-silver nanocomposite containing phosphine oxide moiety in the main chain was synthesized by a convenient ultraviolet irradiation technique.A precursor such as AgNO_3 was used as the sourc...New flame-retardant polyimide-silver nanocomposite containing phosphine oxide moiety in the main chain was synthesized by a convenient ultraviolet irradiation technique.A precursor such as AgNO_3 was used as the source of the silver particles.Polyimide 6 as a source of polymer was synthesized by polycondensation reaction of bis（3-aminophenyl） phenyl phosphine oxide 4 with pyromellitic anhydride 5 in the presence of iso-quinoline as base and in m-cresol solution.The resulting composite film was characterized by FTIR spectroscopy,X-ray diffraction（XRD）,transmission electron microscopy（TEM）,thermogravimetry（TGA） and differential scanning calorimetry（DSC）.The average size of the nanometer Ag particles is about 10 nm.The temperature of 5 and 10%weight loss and also the char yield at 600℃of polyimide-silver nanocomposite 6a were higher than the pure PI 6.展开更多
Due to the discharge of industrialwastewater,urban domestic sewage,and intensive marine aquaculture tailwater,nitrate(NO_(3)^(−))pollution has emerged as a significant issue in offshore waters.Nitrate pollution affect...Due to the discharge of industrialwastewater,urban domestic sewage,and intensive marine aquaculture tailwater,nitrate(NO_(3)^(−))pollution has emerged as a significant issue in offshore waters.Nitrate pollution affects aquatic life and may interact with other pollutants,leading to comprehensive toxicity.Cadmium(Cd^(2+))is the most widespread metal contaminant,adversely affecting aquatic life in the coastal waters of China.Despite this,few studies have focused on the synergistic toxicity of NO_(3)^(−)and Cd^(2+)in marine organisms.This study conducted a 30-day exposure experiment on marine Japanese flounder(Paralichthys olivaceus)to explore the synergistic toxicity of NO_(3)^(−)and Cd^(2+).Our results demonstrated that the exposure to Cd^(2+)alone induced slight histopathological changes in the liver.However,malformations such as hepatic vacuolar degeneration and sinusoid dilatationwere exacerbated under co-exposure.Moreover,co-exposure induced the downregulation of antioxidants and the upregulation of the product malonaldehyde(MDA)from lipid peroxidation,indicating potent oxidative stress in the liver.The increased mRNA expression of IL-8,TNF-α,and IL-1β,along with the decreased expression level of TGF-β,indicated a synergistic inflammatory response in the organisms.Furthermore,the co-exposure led to an abnormal expression of P53,caspase-3,caspase-9,Bcl-2,and Bax,and disturbed the apoptosis in the liver through TUNEL staining analysis.Overall,our results imply that co-exposure synergistically affects inflammation,redox status,and apoptosis in flounders.Therefore,the findings from this study provide valuable perspectives on the ecological risk assessment of marine teleosts co-exposure to NO_(3)^(−)and Cd^(2+).展开更多
篢he oxidative coupling reaction of isorhapontigenin using sliver oxide as oxidant afforded a major product, named shegansu B（2）， which was isolated from the roots of Belamcanda chinensis (L．)DC. Both the natural ...篢he oxidative coupling reaction of isorhapontigenin using sliver oxide as oxidant afforded a major product, named shegansu B（2）， which was isolated from the roots of Belamcanda chinensis (L．)DC. Both the natural and synthetic Shegansu B have the same potent antagonism activities of leukotriene B4，D4 receptor．展开更多
Nitrogen doping of silver oxide （AgxO） film is necessary for its application in transparent conductive film and diodes because intrinsic AgxO film is a p-type semiconductor with poor conductivity. In this work, a se...Nitrogen doping of silver oxide （AgxO） film is necessary for its application in transparent conductive film and diodes because intrinsic AgxO film is a p-type semiconductor with poor conductivity. In this work, a series of AgxO films is deposited on glass substrates by direct-current magnetron reactive sputtering at different flow ratios （FRs） of nitrogen to 02. Evolutions of the structure, the refiectivity, and the transmissivity of the film are studied by X-ray diffractometry and sphectrophotometry, respectively. The specular transmissivity and the specular refiectivity of the film decreasing with FR increasing can be attributed to the evolution of the phase structure of the film. The nitrogen does not play the role of an acceptor dopant in the film deposition.展开更多
A series of zinc borotellurite glass co-doped with lanthanum and silver oxide with the chemical formula of [{[(TeO2)0.7(B2O3)0.3]0.7(ZnO)0.3}0.96(La2O3)0.04]1-x(Ag2O)x where the molar frac-tion of silver oxide, x = 0....A series of zinc borotellurite glass co-doped with lanthanum and silver oxide with the chemical formula of [{[(TeO2)0.7(B2O3)0.3]0.7(ZnO)0.3}0.96(La2O3)0.04]1-x(Ag2O)x where the molar frac-tion of silver oxide, x = 0.02, 0.04, 0.06, 0.08 and 0.10 had been successfully prepared via the conventional melt-quenching technique. The structural properties of the glasses were unveiled through X-ray Diffraction (XRD) and Fourier Transform Infra-Red (FTIR) spectroscopy while optical properties of the glasses were investigated with Ultra Violet Visible (UV-Vis) spectropho-toscopy. The short range periodic atomic arrangement in the glass matrix that implies the amorphous nature of the glass was confirmed with the presence of a broad hump in the XRD pattern. On the other hand, the three absorption bands observable in the FTIR spectra had proven the existence of BO4, BO3 as well as TeO4 units in the glass network. The absorbance values retrieved from UV-Vis spectroscopy were utilized to calculate the indirect energy band gap and Urbach energy values of the fabricated glass. By employing the equations proposed by Mott and Davis, the obtained indirect energy band gap have val-ues ranging from 2.16 to 4.16 eV.The decreasing trend in indirect energy band gap and increasing Urbach energy values were related to the increasing num-ber of nonbridging oxygen (NBO) in the glass that is created from the breaking of Te-O-Te or B-O-B bonds after lanthanum as well as silver oxide are incor-porated into the zinc borotellurite glass network.展开更多
基金supported by the Open Fund of Anhui Engineering Research Center for Ecoagriculture of Traditional Chinese Medicine(WXZR202318)High-level Talents Research Initiation Fund of West Anhui University(WGKQ2022025)+3 种基金Quality Engineering Project of West Anhui University(wxxy2024011)Quality Engineering Project of Anhui Province(2024zybj032)Development of Big Data Integration and Analysis Platform for Traditional Chinese Medicine Genomics(0045025050)Anhui Innovation and Entrepreneurship Training Program for College Students(S202510376030).
文摘Heavy metal pollution has become a pervasive environmental issue affecting numerous regions worldwide.Recently,there has been significant attention given to the application of nano-enabled technologies with the purpose of enhancing plant development and alleviating heavy metal stress.This study aimed to illustrate the potential of zinc oxide nanoparticles(ZnO-NPs)to enhance the morphological traits of D.huoshenense exposed to cadmium(Cd)stress.The chemical structure and elemental composition of the ZnO-NPs were characterised by a series of analytical methods,including X-ray diffraction,UV-Vis spectrometry,XPS,andTEM.Plant samples usedwere collected at 0,5,and 15 days in order to assess physiological and biochemical parameters under different Cd treatments.ZnONPs administered in pot experiments have been shown to enhance plant proliferation through the modulation of Cd enrichment levels.The results revealed that ZnO-NPs enhanced plant growth by increasing soluble sugars and proline levels,enhancing activities of antioxidant enzymes(SOD,POD,CAT,APX)and reducing electrolyte leakage(EL)and malondialdehyde(MDA)content.Furthermore,ZnO-NPs enhanced the net photosynthetic rate,transpiration,stomatal conductance,and chlorophyll content in leaves subjected to Cd stress at the 10-day sampling stage.Exogenous ZnO-NPs significantly elevated the expression of genes associated with flavonoid biosynthesis,potentially facilitating the accumulation of medicinal compounds to mitigate Cd stress.Taken together,these findings provide a novel perspective on the strategies employed by medicinal plants in response to Cd.
基金supported by the National Natural Science Foundation of China(21577088)~~
文摘The composite oxides xAg/Co_（0.93）Ce_（0.07）（x=Ag/（Co＋Ce） molar ratio）,intended for use as high performance catalytic materials,were successfully prepared via citric acid complexation.The effects of silver on the performance of these substances during soot combustion were subsequently investigated.Under O_2,the 0.3Ag/Co_（0.93）Ce_（0.07） catalyst resulted in the lowest ignition temperature,T_（10）,of197 ℃,while the minimum light-off temperature was obtained from both 0.2Ag/Co_（0.93）Ce_（0.07） and0.3Ag/Co_（0.93）Ce_（0.07） in the NO_x atmosphere.These materials were also characterized by various techniques,including H_2,soot and NO_x temperature programmed reduction,X-ray diffraction,and electron paramagnetic resonance,Raman,X-ray photoelectron,and Fourier transform infrared spectroscopic analyses.The results demonstrated that silver significantly alters the catalytic behavior under both O_2 and NO_x,even though the lattice structure of the mixed oxide is not affected.Surface silver oxides generated under the O_2 atmosphere favor soot combustion by participating in the redox cycles between soot and the silver oxide,whereas the AgNO_3 that forms in a NO_x-rich atmosphere facilitates soot abatement at a lower temperature.The inferior activity of AgNO_3 relative to that of Ag_2O results in the different catalytic performance in the presence of NO_x or O_2.
基金supported by the National Natural Science Foundation of China (No. 50808070, 51039001)the Program for New Century Excellent Talents in University from the Ministry of Education of China (No. NCET-09-0328)+4 种基金the Postdoctoral Science Foundation of China (No.20070410301, 200902468)the Program for Changjiang Scholars and Innovative Research Team in University(No. IRT0719)the Hunan Provincial Natural Science Foundation of China (No. 08JJ4006, 10JJ7005)the Xiangjiang Water Environmental Pollution Control Project subjected to the National Key Science and Technology Project for Water Environmental Pollution Control (No.2009ZX07212-001-02, 2009ZX07212-001-06)the Hunan Key Scientific Research Project (No. 2009FJ1010)
文摘This study describes a new effective adsorbent for cadmium removal from aqueous solution synthesized by coating a shellac layer, a natural biodegradable and renewable resin with abundant hydroxyl and carboxylic groups, on the surface of iron oxide magnetic nanoparticles. Transmission Electron Microscopy （TEM） imaging showed shellac-coated magnetic nanoparticle （SCMN） adsorbents had a core-shell structure with a core of 20 nm and shell of 5 nm. Fourier Transform Infrared Spectroscopic analysis suggested the occurrence of reaction between carboxyl groups on the SCMN adsorbent surface and cadmium ions in aqueous solution. Kinetic data were well described by pseudo second-order model and adsorption isotherms were fitted with both Langmuir and Freundlich models with maximum adsorption capacity of 18.80 mg]g. SCMN adsorbents provided a favorable adsorption capacity under high salinity conditions, and cadmium could easily be desorbed using mild organic acid solutions at low concentration.
基金supported by the Zhejiang Provincial Natural Science Foundation of China (No. Y3100246)the Innovation Team of the Safety Standards and Testing Technology for Agricultural Products of Zhejiang Province(No. 2010R50028)
文摘The effect of calcium chloride （CaCl2） on rice seedling growth under cadmium chloride （CdCl2） stress, as well as the possible role of endogenous nitric oxide （NO） in this process, was studied. The growth of rice seedlings was seriously inhibited by CdCl2, and the inhibition was significantly mitigated by CaCl2. However, hemoglobin （Hb） and 2-（4-carboxyphenyl）-4, 4,5,5-tetramethylimidazoline- l-oxyl-3-oxide （cPTIO） weakened the promotion effect of CaCl2. The results of NO fluorescence localization suggest that growth accelerated by CaCl2 might be associated with elevated NO levels. The content of Cd, protein thiols （PBT）, and nonprotein thiols （NPT） in cell walls, cell organelles, and soluble fractions, respectively, of rice seedlings decreased considerably in the presence of CaCl2, whereas the content of pectin, hemicellulose 1 （HC1）, and hemicellulose 2 （HC2） increased significantly. Elimination of endogenous NO in Cd＋Ca treatment could promote the transportation of Cd2＋ to cell organelles and soluble fractions and increase the content of NPT and PBT in leaves. In addition, transportation of Cd2＋ to cell organelles and soluble fractions was retarded in roots, the content of NPT increased, and the content of PBT decreased. With elimination of endogenous NO in Cd＋Ca treatment, the content of pectin, HC1, and HC2 decreased significantly. Thus, Ca may alleviate Cd toxicity via endogenous NO with variation in the levels of NPT, PBT, and matrix polysaccharides.
基金supported by the National Key Research and Development Program of China(2016YFB0600902)。
文摘Silver catalyst has been extensively investigated for photocatalytic and electrochemical CO_(2)reduction.However,its high activity for selective hydrogenation of CO_(2)to methanol has not been confirmed.Here,the feasibility of the indium oxide supported silver catalyst was investigated for CO_(2)hydrogenation to methanol by the density functional theoretical(DFT)study and then by the experimental investigation.The DFT study shows there exists an intense Ag-In_(2)O_(3)interaction,which causes silver to be positively charged.The positively charged Ag species changes the electronic structure of the metal,facilitates the formation of the Ag-In_(2)O_(3)interfacial site for activation and dissociation of carbon dioxide.The promoted CO_(2)dissociation leads to the enhanced methanol synthesis via the CO hydrogenation route as CO_(2)^(*)→CO^(*)→HCO^(*)→H_(2)CO^(*)→H_(3)CO^(*)→H_(3)COH^(*).The Ag/In_(2)O_(3)catalyst was then prepared using the deposition-precipitation method.The experimental study confirms the theoretical prediction.The methanol selectivity of CO_(2)hydrogenation on Ag/In_(2)O_(3)reaches 100.0%at reaction temperature of 200℃.It remains more than 70.0%between 200 and 275℃.At 300℃and 5 MPa,the methanol selectivity still keeps 58.2%with a CO_(2)conversion of 13.6%and a space-time yield(STY)of methanol of 0.453 g_(methanol)g_(cat)^(-1)h^(-1),which is the highest methanol STY ever reported for silver catalyst.The catalyst characterization confirms the intense Ag-In_(2)O_(3)interaction as well,which causes high Ag dispersion,increases and stabilizes the oxygen vacancies and creates the active Ag-In_(2)O_(3)interfacial site for the enhanced CO_(2)hydrogenation to methanol.
文摘Silver tin oxide composite powders were synthesized by the hydrothermal method with a silver ammine solution and a Na2SnO3 solution as raw materials. H2C2O4 was used as the co-precipitator of silver ions and tin ions. The co-precipitation conditions were investigated. The results show that the co-precipitate of Ag2C2O4 and Sn（OH）4 is available when the pH value of the solution is 4.27-8.36. Using the obtained precipitate as precursor,the reduction of Ag＋ and the crystallization of tin oxide were carried out simultaneously by the hydrothermal method and silver tin oxide composite powders were obtained. The composite powders were characterized by X-ray diffraction （XRD） analysis,scanning electron microscope （SEM）,and energy spectrum analysis. The results show that the silver tin oxide composite powders are small with a diameter of about 2 μm and with homogeneous distribution of tin.
基金supported by the National Key Technology R&D Program (No.2018YFD0800202)。
文摘A new calcium-modified and starch-stabilized ferromanganese binary oxide (Ca-SFMBO)sorbent was fabricated with different Ca concentrations for the adsorption of arsenic (As)and cadmium (Cd) in water.The maximum As(Ⅲ) and Cd(Ⅱ) adsorption capacities of 1%CaSFMBO were 156.25 mg/g and 107.53 mg/g respectively in single-adsorption systems.The adsorption of As and Cd by the Ca-SFMBO sorbent was pH-dependent at values from 1 to 7,with an optimal adsorption pH of 6.In the dual-adsorbate system,the presence of Cd(Ⅱ) at low concentrations enhanced As(Ⅲ) adsorption by 33.3%,while the adsorption of As(Ⅲ) was inhibited with the increase of Cd(Ⅱ) concentration.Moreover,the addition of As(Ⅲ) increased the adsorption capacity for Cd(Ⅱ) up to two-fold.Through analysis by X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR),it was inferred that the mechanism for the co-adsorption of Cd(Ⅱ) and As(Ⅲ) included both competitive and synergistic effects,which resulted from the formation of ternary complexes.The results indicate that the Ca-SFMBO material developed here could be used for the simultaneous removal of As(Ⅲ) and Cd(Ⅱ) from contaminated water.
文摘The mechanical decomposing and mechanochemical reductions of silver oxide for preparation of nanocrystalline silver powders by high planetary ball mill was investigated. XRD and HRSEM techniques were used to characterize the structural evolution and morphological changes of products. The results show that the nanostructured silver with an average crystallite size of 14 nm and internal strain of 0.75% is synthesized by mechanical decomposing of Ag2O after 95 h milling. While, the product of mechanochemical reduction of silver oxide using graphite after 22 h milling is nanostructured silver with an average crystallite size of 28 nm and internal strain of 0.44%.
文摘The rapid industrial growth and increasing population have led to significant pollution and deterioration of the natural atmospheric environment.Major atmospheric pollutants include NO_(2)and CO_(2).Hence,it is imperative to develop NO_(2)and CO_(2)sensors for ambient conditions,that can be used in indoor air quality monitoring,breath analysis,food spoilage detection,etc.In the present study,two thin film nanocomposite(nickel oxide-graphene and nickel oxide-silver nanowires)gas sensors are fabricated using direct ink writing.The nano-composites are investigated for their structural,optical,and electrical properties.Later the nano-composite is deposited on the interdigitated electrode(IDE)pattern to form NO_(2)and CO_(2)sensors.The deposited films are then exposed to NO_(2)and CO_(2)gases separately and their response and recovery times are determined using a custom-built gas sensing setup.Nickel oxide-graphene provides a good response time and recovery time of 10 and 9 s,respectively for NO_(2),due to the higher electron affinity of graphene towards NO_(2).Nickel oxide-silver nanowire nano-composite is suited for CO_(2)gas because silver is an excellent electrocatalyst for CO_(2)by giving response and recovery times of 11 s each.This is the first report showcasing NiO nano-composites for NO_(2)and CO_(2)sensing at room temperature.
基金supported by the Key Technologies R&D Program of China during the 11th Five-Year Plan period (2006BAD02A03)the the Foundation of Key Program of Jiangsu Province (2007JA148)the Natural Science Foundation of Jiangsu Province, China (BK2010449)
文摘Nitric oxide （NO） is a gaseous signaling molecule in plants that plays a key role in mediating a wide range of physiological processes and responses to biotic and abiotic stresses. The present study was conducted to investigate the effects of the exogenous application of sodium nitroprusside （SNP）, an NO donor, on cadmium （Cd）-induced oxidative stress and Cd uptake in rice plants. Rice plants were exposed to Cd stress （0.2 mmol L^-1 CdC12） and different concentrations of SNP （0.05, 0.1, 0.2, and 0.4 mmol L^-1）. A SNP concentration of 0.1 mmol L^-1 （SNP 10） significantly reduced the Cd-induced decrease in shoot and root dry weights and leaf chlorophyll concentrations. The addition of NO also reduced the malondialdehyde （MDA）, hydrogen peroxide （H202） and ascorbic acid （ASA） concentrations. However, the reduction in glutathione （GSH） concentration was inhibited by NO treatment. Moreover, NO prevented the Cd-induced increase in antioxidative enzyme activity. The amount of Cd accumulation in rice plants was also influenced by the addition of NO. The NO supplied by the SNP enhanced the Cd tolerance of the rice by increasing the Cd uptake by the roots and decreasing the Cd accumulation by the shoots. However, the application of potassium ferrocyanide （Cd＋Fe） or sodium nitrate and nitrite （Cd＋N） （without NO release）, did not exhibit the effects of the SNP. Furthermore, the effects of the SNP were reversed by the addition of hemoglobin （an NO scavenger）. Our results suggested that exogenous NO was involved in the resistance of rice to Cd-toxicity.
基金Supported by the National Natural Science Foundation of China(No.20477014).
文摘Natural surface coatings collected from natural substances （NSCsNS） were employed to study the roles of the main chemical components （iron oxides, manganese oxides, and other components） in controlling the adsorption of lead（Pb） and cadmium（Cd） in aquatic environments. The selective chemical extraction followed by the adsorption of Pb and Cd experiments and statistical analysis, were used to investigate the adsorption property of each component. Hydroxylamine hydrochloride was used to remove manganese oxides selectively, and sodium dithionite was used to extract iron oxides and manganese oxides. The result indicated that iron oxides and manganese oxides played an important role in the adsorption of Pb and Cd on NSCsNS, and the relative contribution was about two-thirds. The contribution of manganese oxides was the greatest, with a lesser role indicated for other components. The adsorption ability of manganese oxides for Pb and Cd was greater than that of iron oxides or other components for Pb and Cd. The Pb adsorption observed in each component was greater than Cd adsorption.
基金supported by the Internal Research Grant,Alfaisal University(IRG 2014,No.4050101011410)
文摘In this paper, silver nanoparticles （AgNPs） and AgNPs/reduced graphene oxide （RGO） nanocomposites were prepared using lemon juice under microwave irradiation （MWI） and UV light irradiation. AgNPs with face-centered cubic structure RGO peaks were observed by X-ray diffraction. The UV-Vis spectrum showed modifications in the absorption peaks of the AgNPs with the concentration of the precursor solution and irradiation time, and the optimized condition was obtained for 20 min MWI and 60 s of UV light. Raman analysis confirmed the presence of RGO as D and G bands in the spectrum. Transmission electron microscopy analyses confirmed that the AgNPs of size ranging from 3 to 8 nm were anchored onto the RGO sheets. The antibacterial properties of the AgNPs/RGO nanocomposites were investigated using gram-negative bacteria. The results revealed that AgNPs/RGO nanocomposites consisting of approximately 5 wt% AgNPs can achieve antibacterial performance similar to that of neat AgNPS. This method can be useful for the applications of AgNPs-based nanocomposites, where minute amount of silver will be utilized.
基金financially supported by the National Natural Science Foundation of China(No.30300434)the 0utstanding Youth Foundation of Sichuan Province(No.04ZQ026-039).
文摘A series of acyls （Ac, Bz and Ts） were introduced regioselectively to the 2-hydroxyl in methyl and ally 3-O-benzyl-α-L-rhamnopyranosides mediated by silver（I） oxide in the presence of a catalytic amount of potassium iodide in 56-78% yields.
文摘Thermodynamic analysis of the possibility of silver nanocrystalline preparation by high energy milling silver oxide was investigated. The molar Gibbs free energy function of mechanically activated samples was calculated from the structural defects such as amorphization, dislocation and surface energy. According to the molar Gibbs free energy function, the equilibrium temperature of mechanical reduction of silver oxide milled for 21 h was estimated at about 304 K. Consequently, at this temperature silver oxide cannot be stable and will transform to silver during the milling.
基金National Natural Science Foundation of China(61302044,61671140)Zhongshan Science and Technology Projects(2015B2312,2015B2300)
文摘We fabricated flexible transparent conductive films composed of silver nanowires(AgNWs)and reduced graphene oxide(rGO)as hybrid transparent electrode and mixed cellulose eater(MCE)as substrate by a vacuum-filtrating method.Effect of rGO on the electrical,optical and mechanical properties of the flexible transparent films were studied.The results show that with the increase of rGO deposition density,the optical transmission at 550 nm has a little decrease,while the sheet resistance(Rs)gradually decreases.Tape tests up to 200 cycles and bending fatigue tests up to 200 cycles were performed by monitoring the in-situ resistance change.The film sustains excellent reliability of the AgNWs/rGO hybrid conductive networks,where the fractional resistance change is little overt increase after tape tests and less than 3%after bending test.The exc ellent mechanical properties of the AgNWs/rGO film can be attributed to the burying of the AgNWs and RGO film at the surface of mixed cellulose eaters(MCEs).
文摘New flame-retardant polyimide-silver nanocomposite containing phosphine oxide moiety in the main chain was synthesized by a convenient ultraviolet irradiation technique.A precursor such as AgNO_3 was used as the source of the silver particles.Polyimide 6 as a source of polymer was synthesized by polycondensation reaction of bis（3-aminophenyl） phenyl phosphine oxide 4 with pyromellitic anhydride 5 in the presence of iso-quinoline as base and in m-cresol solution.The resulting composite film was characterized by FTIR spectroscopy,X-ray diffraction（XRD）,transmission electron microscopy（TEM）,thermogravimetry（TGA） and differential scanning calorimetry（DSC）.The average size of the nanometer Ag particles is about 10 nm.The temperature of 5 and 10%weight loss and also the char yield at 600℃of polyimide-silver nanocomposite 6a were higher than the pure PI 6.
基金supported by the National Natural Science Foundation of China(No.32202963)the Natural Science Foundation of Jiangsu Province(No.BK20220681)+3 种基金the Doctoral Program of Entrepreneurship and Innovation in Jiangsu Province(No.JSSCBS20221625)the Scientific Research Foundation Program of Jiangsu Ocean University(No.KQ22009)the Undergraduate Innovation&Entrepreneurship Training Program of Jiangsu Province,China(No.SY202411641631001)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX2023-112).
文摘Due to the discharge of industrialwastewater,urban domestic sewage,and intensive marine aquaculture tailwater,nitrate(NO_(3)^(−))pollution has emerged as a significant issue in offshore waters.Nitrate pollution affects aquatic life and may interact with other pollutants,leading to comprehensive toxicity.Cadmium(Cd^(2+))is the most widespread metal contaminant,adversely affecting aquatic life in the coastal waters of China.Despite this,few studies have focused on the synergistic toxicity of NO_(3)^(−)and Cd^(2+)in marine organisms.This study conducted a 30-day exposure experiment on marine Japanese flounder(Paralichthys olivaceus)to explore the synergistic toxicity of NO_(3)^(−)and Cd^(2+).Our results demonstrated that the exposure to Cd^(2+)alone induced slight histopathological changes in the liver.However,malformations such as hepatic vacuolar degeneration and sinusoid dilatationwere exacerbated under co-exposure.Moreover,co-exposure induced the downregulation of antioxidants and the upregulation of the product malonaldehyde(MDA)from lipid peroxidation,indicating potent oxidative stress in the liver.The increased mRNA expression of IL-8,TNF-α,and IL-1β,along with the decreased expression level of TGF-β,indicated a synergistic inflammatory response in the organisms.Furthermore,the co-exposure led to an abnormal expression of P53,caspase-3,caspase-9,Bcl-2,and Bax,and disturbed the apoptosis in the liver through TUNEL staining analysis.Overall,our results imply that co-exposure synergistically affects inflammation,redox status,and apoptosis in flounders.Therefore,the findings from this study provide valuable perspectives on the ecological risk assessment of marine teleosts co-exposure to NO_(3)^(−)and Cd^(2+).
文摘篢he oxidative coupling reaction of isorhapontigenin using sliver oxide as oxidant afforded a major product, named shegansu B（2）， which was isolated from the roots of Belamcanda chinensis (L．)DC. Both the natural and synthetic Shegansu B have the same potent antagonism activities of leukotriene B4，D4 receptor．
基金Project supported by the National Natural Science Foundation of China (Grant No. 60807001)the Foundation of Henan Educational Committee,China (Grant No. 2010A140017)the College Young Teachers Program of Henan Province and the Graduate Innovation Fund of Zhengzhou University (Grant No. 11L10102)
文摘Nitrogen doping of silver oxide （AgxO） film is necessary for its application in transparent conductive film and diodes because intrinsic AgxO film is a p-type semiconductor with poor conductivity. In this work, a series of AgxO films is deposited on glass substrates by direct-current magnetron reactive sputtering at different flow ratios （FRs） of nitrogen to 02. Evolutions of the structure, the refiectivity, and the transmissivity of the film are studied by X-ray diffractometry and sphectrophotometry, respectively. The specular transmissivity and the specular refiectivity of the film decreasing with FR increasing can be attributed to the evolution of the phase structure of the film. The nitrogen does not play the role of an acceptor dopant in the film deposition.
文摘A series of zinc borotellurite glass co-doped with lanthanum and silver oxide with the chemical formula of [{[(TeO2)0.7(B2O3)0.3]0.7(ZnO)0.3}0.96(La2O3)0.04]1-x(Ag2O)x where the molar frac-tion of silver oxide, x = 0.02, 0.04, 0.06, 0.08 and 0.10 had been successfully prepared via the conventional melt-quenching technique. The structural properties of the glasses were unveiled through X-ray Diffraction (XRD) and Fourier Transform Infra-Red (FTIR) spectroscopy while optical properties of the glasses were investigated with Ultra Violet Visible (UV-Vis) spectropho-toscopy. The short range periodic atomic arrangement in the glass matrix that implies the amorphous nature of the glass was confirmed with the presence of a broad hump in the XRD pattern. On the other hand, the three absorption bands observable in the FTIR spectra had proven the existence of BO4, BO3 as well as TeO4 units in the glass network. The absorbance values retrieved from UV-Vis spectroscopy were utilized to calculate the indirect energy band gap and Urbach energy values of the fabricated glass. By employing the equations proposed by Mott and Davis, the obtained indirect energy band gap have val-ues ranging from 2.16 to 4.16 eV.The decreasing trend in indirect energy band gap and increasing Urbach energy values were related to the increasing num-ber of nonbridging oxygen (NBO) in the glass that is created from the breaking of Te-O-Te or B-O-B bonds after lanthanum as well as silver oxide are incor-porated into the zinc borotellurite glass network.
