Heavy metal pollution is a widespread phenomenon in many countries of the world.In this study,we conducted a field investigation to assess the status of heavy metal pollution in urban soils of Dushanzi,a district of K...Heavy metal pollution is a widespread phenomenon in many countries of the world.In this study,we conducted a field investigation to assess the status of heavy metal pollution in urban soils of Dushanzi,a district of Karamay city in Xinjiang,China.A total of 56 soil samples in the topsoil layer of 0–15 cm were collected within the urban area and seven elements(Cu,Zn,Cd,Pb,Cr,As and Ni) were analyzed.The mean concentrations of these metals were all higher than their corresponding background values of soils in Xinjiang.We used the pollution index and ecological risk index to assess the degree of heavy metal pollution and the potential ecological risk of urban soils.The pollution index values of Cu,Zn,Cd,Pb,Cr,As and Ni were 1.81,1.35,4.64,1.27,1.80,1.39 and 1.22,respectively;and the potential ecological risk index values for them were 12.03,1.79,185.05,8.39,4.78,18.44 and 1.79,respectively.These results indicated that urban soils in Dushanzi were polluted by heavy metals to some extent and demonstrated a high ecological risk,as influenced by industrial activities.Cd was the key element for the metal pollution of urban soils in the study area.Correlation analyses,principal component analysis coupled with the spatial distribution maps of element concentrations further revealed that heavy metal pollution of urban soils can be mainly attributed to petrochemical industry,coal chemical industry,traffic and commercial activities.展开更多
Au-Ag alloy nanoparticles with different cavity sizes have great potential for improving photocatalytic performance due to their tunable plasmon effect.In this study,galvanic replacement was combined with co-reduction...Au-Ag alloy nanoparticles with different cavity sizes have great potential for improving photocatalytic performance due to their tunable plasmon effect.In this study,galvanic replacement was combined with co-reduction with the reaction kinetics processes regulated to rapidly synthesize Au-Ag hollow alloy nanoparticles with tunable cavity sizes.The position of the localized surface plasmon resonance(LSPR)peak could be effectively adjusted between 490 nm and 713 nm by decreasing the cavity size of the Au-Ag hollow nanoparticles from 35 nm to 20 nm.The plasmon-enhanced photocatalytic H2 evolution of alloy nanoparticles with different cavity sizes was investigated.Compared with pure P25(TiO2),intact and thin-shelled Au-Ag hollow nanoparticles(HNPs)-supported photocatalyst exhibited an increase in the photocatalytic H2 evolution rate from 0.48μmol h^−1 to 4μmol h^−1 under full-spectrum irradiation.This improved photocatalytic performance was likely due to the plasmon-induced electromagnetic field effect,which caused strong photogenerated charge separation,rather than the generation of hot electrons.展开更多
Three inexpensive and air-/moisture-stable Salen-Cu complexes 1-3 were evaluated to be a novel class of catalysts for the N-arylation of imidazoles with aryl halides. A variety of aryl iodides, bromides underwent the ...Three inexpensive and air-/moisture-stable Salen-Cu complexes 1-3 were evaluated to be a novel class of catalysts for the N-arylation of imidazoles with aryl halides. A variety of aryl iodides, bromides underwent the coupling with imida-zoles, promoted by the complex 3, in moderate to excellent yields without the protection by an inert gas.展开更多
Novel CaCO_(3)-enhanced Mn-Fe mixed metal oxides(CMFC)were successfully prepared for the first time by a simple-green hydrothermal strategy without any surfactant or template combined with calcination process.These ox...Novel CaCO_(3)-enhanced Mn-Fe mixed metal oxides(CMFC)were successfully prepared for the first time by a simple-green hydrothermal strategy without any surfactant or template combined with calcination process.These oxides were then employed as an adsorbent for adsorptive removal of excess fluoride ions.The adsorbent was characterized by SEM,XPS,XRD,FTIR,and BET analysis techniques.The adsorption property of CMFC toward fluoride ion was analyzed by batch experiments.In fact,CMFC exhibited adsorption capacity of 227.3 mg∙g^(-1)toward fluoride ion.Results showed that ion exchange,electrostatic attraction and chemical adsorption were the main mechanism for the adhesion of large amount of fluoride ion on the CMFC surface,and the high adsorption capacity responded to the low pH of the adsorption system.When the fluoride ion concentration was increased from 20 to 200 mg∙L^(-1),Langmuir model was more in line with experimental results.The change of fluoride ion adsorption with respect to time was accurately described by pseudosecond-order kinetics.After five cycles of use,the adsorbent still maintains a performance of 70.6%of efficiency,compared to the fresh adsorbent.Therefore,this material may act as a potential candidate for adsorbent with broad range of application prospects.展开更多
The lanthanum ricinoleate(abbreviated as Lari3) of rare earth heat stabilizer was synthesized by the reaction of ricinoleic acid, lanthanum nitrate and sodium hydroxide. The IR and fluorescence spectra methods confirm...The lanthanum ricinoleate(abbreviated as Lari3) of rare earth heat stabilizer was synthesized by the reaction of ricinoleic acid, lanthanum nitrate and sodium hydroxide. The IR and fluorescence spectra methods confirmed the structure of the product. The thermal stability of PVC in the presence of Lari3 was studied by the Congo method and using TG analysis. The results showed that Lari3 could be used as a thermal stabilizer for PVC. When the ratio of Lari3/pentaerythritol was 3:1, the complex exhibited better synergistic effect. Incorporation of Lari3 to PVC resulted in a marked increase of maximum and onset degradation temperature as well as elongation and impact strength of PVC. Lari3 might replace the labile chlorine atoms to interrupt the formation of conjugated double bonds in PVC chains and act as HCl scavenger to restrain the self-catalyticdehydrochlorination.展开更多
Phenolic-metal complexation coatings have been discovered to be a universal route for the deposition of multifunctional coatings. However, most complexation coatings have been prepared by the immersion method, which l...Phenolic-metal complexation coatings have been discovered to be a universal route for the deposition of multifunctional coatings. However, most complexation coatings have been prepared by the immersion method, which limits their practical large-scale application. Herein, we describe a facile and green engineering strategy that involves spraying phenolic compound and metal ions on substrate to form in-situ complexation coating with different coordination states. The coating is formed within minutes and it can be achieved in large scale by the spray method. The pyrogallol-Fem complexation coating is prepared at pH 7.5, which consists predominantly of biscoordination complexation with a small amount of tris-coordination complexation. It displays that the water contact angle is near zero due to the generation of rough hierarchical structures and massive hydroxyl groups. The superhydrophilic cotton resulting from the deposition of the pyrogallol-Fe^Ⅲ complexation can separate oil/water mixtures and surfactant-stabilized oil-in-water emulsions with high separation efficiency. The formation of the phenolic-metal complexation coating by using spray technique constitutes a cost-effective and environmentally friendly, strategy with potential to be applied for large-scale surface engineering processes and green oil/water separation.展开更多
3-(Diphenylphosphino)propanoic acid(L2) has proved to be an efficient ligand for the copper-catalyzed C–N coupling reactions.N-arylation of imidazoles with aryl iodides catalyzed by CuCl/L2 was smoothly carried out i...3-(Diphenylphosphino)propanoic acid(L2) has proved to be an efficient ligand for the copper-catalyzed C–N coupling reactions.N-arylation of imidazoles with aryl iodides catalyzed by CuCl/L2 was smoothly carried out in DMSO at 100 8C with a yield up to 98%.N-arylation of 1H-pyrazole with aryl iodides and bromides catalyzed by Cu(OAc)2/L2 in 1 4-dioxane also gave the corresponding products with yields of40%–98%.展开更多
The variation of interlayer coupling can greatly affect the bandstructure of few layered transition metal dichalcogenides(TMDs),for instance,transition of indirect-to-direct bandgap and vice versa,which is correlated ...The variation of interlayer coupling can greatly affect the bandstructure of few layered transition metal dichalcogenides(TMDs),for instance,transition of indirect-to-direct bandgap and vice versa,which is correlated with the charge carrier and optical density.However,methods that can modulate the coupling strength in a controllable way are still lacking.Here,we report a fluidic dynamic strategy to tune the interlayer coupling of folded bi-layer MoS_(2).By controlling the flow direction and particle size of the fluid,mono-layer MoS_(2)can be folded into bi-layer with a controlled folding direction for designated twist angles as well as tunable interlayer coupling.Compared with normally folded bi-layer MoS_(2),the photoluminescence(PL)peak of the direct-bandgap transition for folded bi-layer MoS_(2)by fluid flow is weakened accompanied with the re-appearance of indirect-bandgap transition peak.Besides,the fluid flow creates a clear trajectory on the folded MoS_(2),exhibiting various degrees of interlayer coupling along it.Field-effect transistors(FETs)were further fabricated on tunably coupled folded-bi-layers,proving that the bandstructure and electrical property is strongly correlated with the degree of interlayer coupling.This fluidic dynamic strategy can be extended to other TMDs on any substrate,and together with its excellent capability in controlled interlayer coupling,it will provide a new way for the development of TMDs optoelectronics.展开更多
Herein,an organoboron photocatalyst,aminoquinolate diarylboron(AQDAB),is utilized collaboratively with a nickel catalyst in metallaphotoredox catalyzed C(sp^(2))–P and C(sp^(2))–S cross-coupling reactions.This strat...Herein,an organoboron photocatalyst,aminoquinolate diarylboron(AQDAB),is utilized collaboratively with a nickel catalyst in metallaphotoredox catalyzed C(sp^(2))–P and C(sp^(2))–S cross-coupling reactions.This strategy effectively couples aryl halides with diarylphosphine oxides and thiols at room temperature under an air atmosphere,affording the corresponding triarylphosphine oxides and thioethers in generally moderate to good yields.展开更多
基金funded by the National Natural Science Foundation of China(21267020,21467026)
文摘Heavy metal pollution is a widespread phenomenon in many countries of the world.In this study,we conducted a field investigation to assess the status of heavy metal pollution in urban soils of Dushanzi,a district of Karamay city in Xinjiang,China.A total of 56 soil samples in the topsoil layer of 0–15 cm were collected within the urban area and seven elements(Cu,Zn,Cd,Pb,Cr,As and Ni) were analyzed.The mean concentrations of these metals were all higher than their corresponding background values of soils in Xinjiang.We used the pollution index and ecological risk index to assess the degree of heavy metal pollution and the potential ecological risk of urban soils.The pollution index values of Cu,Zn,Cd,Pb,Cr,As and Ni were 1.81,1.35,4.64,1.27,1.80,1.39 and 1.22,respectively;and the potential ecological risk index values for them were 12.03,1.79,185.05,8.39,4.78,18.44 and 1.79,respectively.These results indicated that urban soils in Dushanzi were polluted by heavy metals to some extent and demonstrated a high ecological risk,as influenced by industrial activities.Cd was the key element for the metal pollution of urban soils in the study area.Correlation analyses,principal component analysis coupled with the spatial distribution maps of element concentrations further revealed that heavy metal pollution of urban soils can be mainly attributed to petrochemical industry,coal chemical industry,traffic and commercial activities.
基金supported by the National Natural Science Foundation of China(No.61704114)the Key areas of Science and Technology Program of Xinjiang Production and Construction Corps,China(No.2018AB004)the National Science Foundation(CBET-1803256).
文摘Au-Ag alloy nanoparticles with different cavity sizes have great potential for improving photocatalytic performance due to their tunable plasmon effect.In this study,galvanic replacement was combined with co-reduction with the reaction kinetics processes regulated to rapidly synthesize Au-Ag hollow alloy nanoparticles with tunable cavity sizes.The position of the localized surface plasmon resonance(LSPR)peak could be effectively adjusted between 490 nm and 713 nm by decreasing the cavity size of the Au-Ag hollow nanoparticles from 35 nm to 20 nm.The plasmon-enhanced photocatalytic H2 evolution of alloy nanoparticles with different cavity sizes was investigated.Compared with pure P25(TiO2),intact and thin-shelled Au-Ag hollow nanoparticles(HNPs)-supported photocatalyst exhibited an increase in the photocatalytic H2 evolution rate from 0.48μmol h^−1 to 4μmol h^−1 under full-spectrum irradiation.This improved photocatalytic performance was likely due to the plasmon-induced electromagnetic field effect,which caused strong photogenerated charge separation,rather than the generation of hot electrons.
文摘Three inexpensive and air-/moisture-stable Salen-Cu complexes 1-3 were evaluated to be a novel class of catalysts for the N-arylation of imidazoles with aryl halides. A variety of aryl iodides, bromides underwent the coupling with imida-zoles, promoted by the complex 3, in moderate to excellent yields without the protection by an inert gas.
基金the Shihezi Science and Technology Plan Project of Eight Division(Grant No.2019GY04)the Double First-Class Counterpart Support University Cooperation Project(Grant No.SHYL-DK201802)the Major Science and Technology Project of Xinjiang Bingtuan(Grant No.2017AA007).
文摘Novel CaCO_(3)-enhanced Mn-Fe mixed metal oxides(CMFC)were successfully prepared for the first time by a simple-green hydrothermal strategy without any surfactant or template combined with calcination process.These oxides were then employed as an adsorbent for adsorptive removal of excess fluoride ions.The adsorbent was characterized by SEM,XPS,XRD,FTIR,and BET analysis techniques.The adsorption property of CMFC toward fluoride ion was analyzed by batch experiments.In fact,CMFC exhibited adsorption capacity of 227.3 mg∙g^(-1)toward fluoride ion.Results showed that ion exchange,electrostatic attraction and chemical adsorption were the main mechanism for the adhesion of large amount of fluoride ion on the CMFC surface,and the high adsorption capacity responded to the low pH of the adsorption system.When the fluoride ion concentration was increased from 20 to 200 mg∙L^(-1),Langmuir model was more in line with experimental results.The change of fluoride ion adsorption with respect to time was accurately described by pseudosecond-order kinetics.After five cycles of use,the adsorbent still maintains a performance of 70.6%of efficiency,compared to the fresh adsorbent.Therefore,this material may act as a potential candidate for adsorbent with broad range of application prospects.
基金Project supported by Bureau of Science and Technology of Xinjiang Production and Construction Corps(2011BC008)
文摘The lanthanum ricinoleate(abbreviated as Lari3) of rare earth heat stabilizer was synthesized by the reaction of ricinoleic acid, lanthanum nitrate and sodium hydroxide. The IR and fluorescence spectra methods confirmed the structure of the product. The thermal stability of PVC in the presence of Lari3 was studied by the Congo method and using TG analysis. The results showed that Lari3 could be used as a thermal stabilizer for PVC. When the ratio of Lari3/pentaerythritol was 3:1, the complex exhibited better synergistic effect. Incorporation of Lari3 to PVC resulted in a marked increase of maximum and onset degradation temperature as well as elongation and impact strength of PVC. Lari3 might replace the labile chlorine atoms to interrupt the formation of conjugated double bonds in PVC chains and act as HCl scavenger to restrain the self-catalyticdehydrochlorination.
基金the National Natural Science Foundation of China (U1703351 and 51663021)the Bingtuan Excellent Young Scholars (CZ027205).
文摘Phenolic-metal complexation coatings have been discovered to be a universal route for the deposition of multifunctional coatings. However, most complexation coatings have been prepared by the immersion method, which limits their practical large-scale application. Herein, we describe a facile and green engineering strategy that involves spraying phenolic compound and metal ions on substrate to form in-situ complexation coating with different coordination states. The coating is formed within minutes and it can be achieved in large scale by the spray method. The pyrogallol-Fem complexation coating is prepared at pH 7.5, which consists predominantly of biscoordination complexation with a small amount of tris-coordination complexation. It displays that the water contact angle is near zero due to the generation of rough hierarchical structures and massive hydroxyl groups. The superhydrophilic cotton resulting from the deposition of the pyrogallol-Fe^Ⅲ complexation can separate oil/water mixtures and surfactant-stabilized oil-in-water emulsions with high separation efficiency. The formation of the phenolic-metal complexation coating by using spray technique constitutes a cost-effective and environmentally friendly, strategy with potential to be applied for large-scale surface engineering processes and green oil/water separation.
基金financial support of this work by the National Basic Research Program of China (973 Program, No. 2012CB722603)the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT1161)+1 种基金the National Natural Science Foundation of China (No. 21103114)the Doctor Foundation of Xinjiang Bingtuan (No. 2012BB010)
文摘3-(Diphenylphosphino)propanoic acid(L2) has proved to be an efficient ligand for the copper-catalyzed C–N coupling reactions.N-arylation of imidazoles with aryl iodides catalyzed by CuCl/L2 was smoothly carried out in DMSO at 100 8C with a yield up to 98%.N-arylation of 1H-pyrazole with aryl iodides and bromides catalyzed by Cu(OAc)2/L2 in 1 4-dioxane also gave the corresponding products with yields of40%–98%.
基金supported by the National Natural Science Foundation of China(51362026)the Technological Innovation Youth Training Project of Xinjiang Uyghur Autonomous Region of China(QN2015YX004)+1 种基金Qun Jing would like to acknowledge the support from the Foundation for High-level Talents in Shihezi University(RCZX201511)the Applied Basic Research Foundation of Science and Technology in Shihezi University(2015ZRKXYQ07)
基金National Natural Science Foundation of China(Nos.21903007 and 22072006)Young Thousand Talents Program(No.110532103)+2 种基金Beijing Normal University Startup funding(No.312232102)the Fundamental Research Funds for the Central Universities(No.310421109)Double First Class General Science and Technology Projects from School of Chemistry and Chemical Engineering,Shihezi University(No.SHYL-YB201903).
文摘The variation of interlayer coupling can greatly affect the bandstructure of few layered transition metal dichalcogenides(TMDs),for instance,transition of indirect-to-direct bandgap and vice versa,which is correlated with the charge carrier and optical density.However,methods that can modulate the coupling strength in a controllable way are still lacking.Here,we report a fluidic dynamic strategy to tune the interlayer coupling of folded bi-layer MoS_(2).By controlling the flow direction and particle size of the fluid,mono-layer MoS_(2)can be folded into bi-layer with a controlled folding direction for designated twist angles as well as tunable interlayer coupling.Compared with normally folded bi-layer MoS_(2),the photoluminescence(PL)peak of the direct-bandgap transition for folded bi-layer MoS_(2)by fluid flow is weakened accompanied with the re-appearance of indirect-bandgap transition peak.Besides,the fluid flow creates a clear trajectory on the folded MoS_(2),exhibiting various degrees of interlayer coupling along it.Field-effect transistors(FETs)were further fabricated on tunably coupled folded-bi-layers,proving that the bandstructure and electrical property is strongly correlated with the degree of interlayer coupling.This fluidic dynamic strategy can be extended to other TMDs on any substrate,and together with its excellent capability in controlled interlayer coupling,it will provide a new way for the development of TMDs optoelectronics.
基金We acknowledge the financial support by the National Natural Science Foundation of China(No.21963010)Shihezi University(funding to L.X.,CXRC201602).
文摘Herein,an organoboron photocatalyst,aminoquinolate diarylboron(AQDAB),is utilized collaboratively with a nickel catalyst in metallaphotoredox catalyzed C(sp^(2))–P and C(sp^(2))–S cross-coupling reactions.This strategy effectively couples aryl halides with diarylphosphine oxides and thiols at room temperature under an air atmosphere,affording the corresponding triarylphosphine oxides and thioethers in generally moderate to good yields.