Superwetting materials have drawn unprecedented attention in the treatment of oily wastewater due to their preferable anti-fouling property and selective oil/water separation.However,it is still a challenge to fabrica...Superwetting materials have drawn unprecedented attention in the treatment of oily wastewater due to their preferable anti-fouling property and selective oil/water separation.However,it is still a challenge to fabricate multifunctional and environmentally friendly materials,which can be stably applied to purify the actual complicated wastewater.Here,a Ag/Ag/α-Fe_(2)O_(3) heterostructure anchored copper mesh was intentionally synthesized using a facile two-step hydrothermal method.The resultant mesh with superhydrophilicity and underwater superoleophobicity was capable of separating various oil/water mixtures with superior separation efficiency and high permeationflux driven by gravity.Benefiting from the joint effects of the smaller band gap of Ag/α-Fe_(2)O_(3) heterojunction,inherent antibacterial capacity of Ag/α-Fe_(2)O_(3) and Ag nanoparticles,favorable conductive substrate,as well as the hierarchical structure with superwettability,such mesh presented remarkably enhanced degradation capability toward organic dyes under visible light irradiation and antibacterial activity against both Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)compared with the pure Ag/α-Fe_(2)O_(3) coated mesh.Impressively,the mesh exhibited bifunctional water purification performance,in which organic dyes were eliminated simultaneously from water during oil/water separation in onefiltration process.More importantly,this mesh behaved exceptional chemical resistance,mechanical stability and long-term reusability.Therefore,this material with multifunctional integration may hold promising potential for steady water purification in practice.展开更多
This study aimed to investigate the mechanism of mineral spontaneous combustion in an open pit. On the study of coal and mineral mixture in open pit mines, as well as through the specifc surface area and Search Engine...This study aimed to investigate the mechanism of mineral spontaneous combustion in an open pit. On the study of coal and mineral mixture in open pit mines, as well as through the specifc surface area and Search Engine Marketing (SEM) experiments, the specifc surface area and aperture characteristics of distribution of open pit coal sample and pit mineral mixture samples were analyzed. Thermal analysis experiments were used to divide the oxidation process was divided into three stages, and the thermal behavior characteristics of experimental samples were characterized. On the basis of the stage division, we explored the transfer law of the key active functional groups of the experimental samples. The apparent activation energy calculation of the key active groups, performed by combining the Achar diferential method with the Coats–Redfern integral method, microstructural and oxidation kinetic properties were revealed. The resulted showed that the mixed sample had high ash, the fxed carbon content was reduced, the specifc surface area was far lower than the raw coal, the large aperture distribution was slightly higher than the medium hole, the micropore was exceptionally low, the gas adsorption capacity was weaker than the raw coal, the pit coal sample had the exceedingly more active functional groups, easy to react with oxygen, more likely to occur naturally, and its harm was relatively large. The mixed sample contained the highest C–O–C functional group absorbance. The functional groups were mainly infuenced by the self-OH content, alkyl side chain, and fatty hydrocarbon in the sample. The main functional groups of the four-like mixture had the highest apparent activation energy, and the two reactions were higher in the low-temperature oxidation phase.展开更多
Temperature variation and gas generation at diferent depths and positions in the coal combustion process were studied to determine the propagation and evolution of high temperature regions in the process of coal spont...Temperature variation and gas generation at diferent depths and positions in the coal combustion process were studied to determine the propagation and evolution of high temperature regions in the process of coal spontaneous combustion.This study selected coal samples from Mengcun,Shaanxi Province,People’s Republic of China,and developed a semi-enclosed experimental system(furnace)for simulating coal combustion.The thermal mass loss of coal samples under various heating rates(5,10,and 15℃/min)was analyzed through thermogravimetric analysis,and the dynamic characteristics of the coal samples were analyzed;the reliability of the semi-enclosed experimental system was verifed through the equal proportional method of fuzzy response.The results reveal that the high-temperature zone is distributed nonlinearly from the middle to the front end of the furnace,and the temperatures of points in this zone decreased gradually as the layer depth increased.The apparent activation energy of the coal samples during combustion frst increased and then decreased as the conversion degree increased.Furthermore,the proportion of mass loss and the mass loss rate in the coal samples observed in the thermogravimetric experiment is consistent with that observed in the frst and second stages of the experiment conducted using the semi-enclosed system.The research fndings can provide a theoretical basis for the prevention and control of hightemperature zones in coal combustion.展开更多
Tuning and optimization of electronic structures and related reaction energetics are critical toward the rational design of efficient electrocatalysts.Herein,experimental and theoretical calculation demonstrate the or...Tuning and optimization of electronic structures and related reaction energetics are critical toward the rational design of efficient electrocatalysts.Herein,experimental and theoretical calculation demonstrate the originally inert N site within polyaniline(PANI)can be activated for hydrogen evolution by proper d-πinterfacial electronic coupling with metal oxide.As a result,the assynthesized WO3 assemblies@PANI via a facile redox-induced assembly and in situ polymerization,exhibits the electrocatalytic production of hydrogen better than other control samples including W18O49@PANI and most of the reported nobel-metal-free electrocatalysts,with low overpotential of 74 mV at 10 mA·cm−2 and small Tafel slope of 46 mV·dec−1 in 0.5M H2SO4(comparable to commercial Pt/C).The general efficacy of this methodology is also validated by extension to other metal oxides such as MoO3 with similar improvements.展开更多
The transfer of the rural collective construction land is increasingly accelerating,and the factors affecting transfer price are manifold. In this paper,the research area is Yichang,and we establish hedonic price mode...The transfer of the rural collective construction land is increasingly accelerating,and the factors affecting transfer price are manifold. In this paper,the research area is Yichang,and we establish hedonic price model to explore and analyze the factors which affect the collective construction land transfer price. The simulation results show that in geographical factors,the higher degree of prosperity,road accessibility and soundness of infrastructure will result in higher collective construction land transfer price; in economic factors,the higher farmers' per capita net income and added value of the village's tertiary industry will lead to higher collective construction land transfer price; in ownership factors,the integrity of usufruct,disposition and possession has increasingly significant impact on collective construction land transfer price. In the process of establishing rural collective construction land circulation market,the government should gradually improve conditions of collective construction land; strengthen the construction of the rural economy,improve the economic attribute of the collective construction land; establish and improve China's rural collective construction land-related laws and regulations,make the rural collective construction land use rights clear,and give the whole rights of occupation,use,earning and disposition.展开更多
A highly sensitive electrochemiluminescence(ECL) biosensing method was developed for monitoring casein kinase Ⅱ(CK2) at subcellular level via bio-bar-code assay.A bio-bar-code probe(h-DNA/AuNPs/pDNA) prepared by conj...A highly sensitive electrochemiluminescence(ECL) biosensing method was developed for monitoring casein kinase Ⅱ(CK2) at subcellular level via bio-bar-code assay.A bio-bar-code probe(h-DNA/AuNPs/pDNA) prepared by conjugating phosphorylated DNA(p-DNA) and hairpin DNA(h-DNA) onto gold nanoparticles(AuNPs) was used as a carrier for ECL signal reagent(Ru(phen)32+) while a specific peptide was used as a recognition substance.A gold ultramicroelectrode with a diameter of 400 nm was fabricated and then modified with the specific peptide via self-assembly technique to obtain peptide modified gold ultramicroelectrode.The peptide on gold ultramicroelectrode was phosphorylated in the presence of CK2 and adenosine 5’-triphosphate,and then the phosphorylated peptide was integrated with the h-DNA/AuNPs/p-DNA through a process mediated by zirconium cations(Zr4+),and finally Ru(phen)32+ was intercalated into h-DNA.A "signal on" ECL method was developed for the detection of CK2 in the range of 0.005-0.2 U/mL with a detection limit of 0.001 U/mL.Additionally,combined efficient subcellular phosphorylation in vivo with bio-bar-code-based ECL biosensing method,the ECL method was further applied to monitor CK2 at subcellular level without tedious subcellular fractionation.It was found that the concentration of CK2 by inserting the peptide modified gold ultramicroelectrode into the nucleus was higher than that into cytoplasm of HeLa cells.A distinct heterogeneity among CK2 concentrations in single cells was observed for cellular heterogeneity assessment.展开更多
A highly selective and sensitive electrochemical method was developed for the detection of serotonin (5-hydroxytryptamine, 5-HT) at gold nanoflowers (Au NFs) and overoxidized polypyrrole (OPPy) modified carbon fiber m...A highly selective and sensitive electrochemical method was developed for the detection of serotonin (5-hydroxytryptamine, 5-HT) at gold nanoflowers (Au NFs) and overoxidized polypyrrole (OPPy) modified carbon fiber microelectrode (CFME). Carbon fiber was firstly modified with gold nanoflowers using electroless deposition method, and then modified with overoxidized polypyrrole using electrochemical polymerization and overoxidization to obtain OPPy/Au NFs/CFME. The obtained OPPy/Au NFs/CFME was characterized by field emission scanning electron microscopy and electrochemical techniques. It was found that the OPPy/Au NFs/CFME showed good sensitivity for the detection of 5-HT in the range of 10 nmol/L-7.0μmol/L with detection limit of 2.3 nmol/L, and negligible interferences from ascorbic acid, 5-hydroxyindole acetic acid and uric acid. The OPPy/Au NFs/CFME was successfully applied to the detection of 5-HT in human serum samples with good recovery. The work demonstrates that the electrochemical method, incorporating signal amplification of Au NFs with higher cation selection of OPPy, provides a promising tool for the detection of 5-HT in biological systems.展开更多
Here we report an example of a general strategy for the immobilization of various different photochromic spiropyran molecules on eco-friendly cheap nanomatrix.The spiropyrans are encapsulated in calcium salt oligomers...Here we report an example of a general strategy for the immobilization of various different photochromic spiropyran molecules on eco-friendly cheap nanomatrix.The spiropyrans are encapsulated in calcium salt oligomers-based gels by centrifugation,forming an inorganic oligomer-based gelatinous photoswitchable hybrid material.Ca^(2+)is also used to regulate the optical properties of spiropyrans through chelation.The oligomer-based gel can not only provide the space required for photoisomerization,but also reduce the interference of the surrounding environment on the photochromic properties.Moreover,a practical paper-based and colloidal flexible substrate platform is constructed for the removal and naked-eye detection of liquid and gaseous hydrazine at room temperature based on the reactivity of the formyl group on spiro-pyrans loaded in Ca3(PO4)2 oligomers.This general strategy can be used for other inorganic oligomer-based molecular switches and sensing systems.展开更多
基金This work was financially supported by the Shandong Provincial Natural Science Foundation(ZR2020QB116)the Excellent Young Talents Foundation in Universities of Anhui Province(gxyq2021223)the Key Research Project of Natural Science in Universities of Anhui Province.(KJ2020A0749).
文摘Superwetting materials have drawn unprecedented attention in the treatment of oily wastewater due to their preferable anti-fouling property and selective oil/water separation.However,it is still a challenge to fabricate multifunctional and environmentally friendly materials,which can be stably applied to purify the actual complicated wastewater.Here,a Ag/Ag/α-Fe_(2)O_(3) heterostructure anchored copper mesh was intentionally synthesized using a facile two-step hydrothermal method.The resultant mesh with superhydrophilicity and underwater superoleophobicity was capable of separating various oil/water mixtures with superior separation efficiency and high permeationflux driven by gravity.Benefiting from the joint effects of the smaller band gap of Ag/α-Fe_(2)O_(3) heterojunction,inherent antibacterial capacity of Ag/α-Fe_(2)O_(3) and Ag nanoparticles,favorable conductive substrate,as well as the hierarchical structure with superwettability,such mesh presented remarkably enhanced degradation capability toward organic dyes under visible light irradiation and antibacterial activity against both Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)compared with the pure Ag/α-Fe_(2)O_(3) coated mesh.Impressively,the mesh exhibited bifunctional water purification performance,in which organic dyes were eliminated simultaneously from water during oil/water separation in onefiltration process.More importantly,this mesh behaved exceptional chemical resistance,mechanical stability and long-term reusability.Therefore,this material with multifunctional integration may hold promising potential for steady water purification in practice.
基金Financial support for this study was kindly provided by the National Natural Science Foundation Project of China(5217-4202)Young Elite Scientists Sponsorship Program of China Association for Science,and Technology(2021QNRC001).
文摘This study aimed to investigate the mechanism of mineral spontaneous combustion in an open pit. On the study of coal and mineral mixture in open pit mines, as well as through the specifc surface area and Search Engine Marketing (SEM) experiments, the specifc surface area and aperture characteristics of distribution of open pit coal sample and pit mineral mixture samples were analyzed. Thermal analysis experiments were used to divide the oxidation process was divided into three stages, and the thermal behavior characteristics of experimental samples were characterized. On the basis of the stage division, we explored the transfer law of the key active functional groups of the experimental samples. The apparent activation energy calculation of the key active groups, performed by combining the Achar diferential method with the Coats–Redfern integral method, microstructural and oxidation kinetic properties were revealed. The resulted showed that the mixed sample had high ash, the fxed carbon content was reduced, the specifc surface area was far lower than the raw coal, the large aperture distribution was slightly higher than the medium hole, the micropore was exceptionally low, the gas adsorption capacity was weaker than the raw coal, the pit coal sample had the exceedingly more active functional groups, easy to react with oxygen, more likely to occur naturally, and its harm was relatively large. The mixed sample contained the highest C–O–C functional group absorbance. The functional groups were mainly infuenced by the self-OH content, alkyl side chain, and fatty hydrocarbon in the sample. The main functional groups of the four-like mixture had the highest apparent activation energy, and the two reactions were higher in the low-temperature oxidation phase.
基金Financial support for this study was kindly provided by the National Natural Science Foundation Project of China(No.51804246,No.52174202)Natural Science Foundation of Xinjiang Province(No.2019D01C057)the Youth Talent Promotion Program of Shaanxi University Association for Science and Technology(No.20200425).
文摘Temperature variation and gas generation at diferent depths and positions in the coal combustion process were studied to determine the propagation and evolution of high temperature regions in the process of coal spontaneous combustion.This study selected coal samples from Mengcun,Shaanxi Province,People’s Republic of China,and developed a semi-enclosed experimental system(furnace)for simulating coal combustion.The thermal mass loss of coal samples under various heating rates(5,10,and 15℃/min)was analyzed through thermogravimetric analysis,and the dynamic characteristics of the coal samples were analyzed;the reliability of the semi-enclosed experimental system was verifed through the equal proportional method of fuzzy response.The results reveal that the high-temperature zone is distributed nonlinearly from the middle to the front end of the furnace,and the temperatures of points in this zone decreased gradually as the layer depth increased.The apparent activation energy of the coal samples during combustion frst increased and then decreased as the conversion degree increased.Furthermore,the proportion of mass loss and the mass loss rate in the coal samples observed in the thermogravimetric experiment is consistent with that observed in the frst and second stages of the experiment conducted using the semi-enclosed system.The research fndings can provide a theoretical basis for the prevention and control of hightemperature zones in coal combustion.
基金The authors appreciate the supports from the National Research Foundation(NRF),Prime Minister’s Office,Singapore,under its Campus for Research Excellence and Technological Enterprise(CREATE)programme.We also acknowledge financial support from the academic research fund AcRF tier 2(M4020246,ARC10/15),Ministry of Education,Singapore.
文摘Tuning and optimization of electronic structures and related reaction energetics are critical toward the rational design of efficient electrocatalysts.Herein,experimental and theoretical calculation demonstrate the originally inert N site within polyaniline(PANI)can be activated for hydrogen evolution by proper d-πinterfacial electronic coupling with metal oxide.As a result,the assynthesized WO3 assemblies@PANI via a facile redox-induced assembly and in situ polymerization,exhibits the electrocatalytic production of hydrogen better than other control samples including W18O49@PANI and most of the reported nobel-metal-free electrocatalysts,with low overpotential of 74 mV at 10 mA·cm−2 and small Tafel slope of 46 mV·dec−1 in 0.5M H2SO4(comparable to commercial Pt/C).The general efficacy of this methodology is also validated by extension to other metal oxides such as MoO3 with similar improvements.
基金Supported by National Social Science Foundation(12CGL092)
文摘The transfer of the rural collective construction land is increasingly accelerating,and the factors affecting transfer price are manifold. In this paper,the research area is Yichang,and we establish hedonic price model to explore and analyze the factors which affect the collective construction land transfer price. The simulation results show that in geographical factors,the higher degree of prosperity,road accessibility and soundness of infrastructure will result in higher collective construction land transfer price; in economic factors,the higher farmers' per capita net income and added value of the village's tertiary industry will lead to higher collective construction land transfer price; in ownership factors,the integrity of usufruct,disposition and possession has increasingly significant impact on collective construction land transfer price. In the process of establishing rural collective construction land circulation market,the government should gradually improve conditions of collective construction land; strengthen the construction of the rural economy,improve the economic attribute of the collective construction land; establish and improve China's rural collective construction land-related laws and regulations,make the rural collective construction land use rights clear,and give the whole rights of occupation,use,earning and disposition.
基金supported by the National Natural Science Foundation of China(Nos.21775097 and 21775098)the Fundamental Research Funds for the Central Universities(No.GK201801006)。
文摘A highly sensitive electrochemiluminescence(ECL) biosensing method was developed for monitoring casein kinase Ⅱ(CK2) at subcellular level via bio-bar-code assay.A bio-bar-code probe(h-DNA/AuNPs/pDNA) prepared by conjugating phosphorylated DNA(p-DNA) and hairpin DNA(h-DNA) onto gold nanoparticles(AuNPs) was used as a carrier for ECL signal reagent(Ru(phen)32+) while a specific peptide was used as a recognition substance.A gold ultramicroelectrode with a diameter of 400 nm was fabricated and then modified with the specific peptide via self-assembly technique to obtain peptide modified gold ultramicroelectrode.The peptide on gold ultramicroelectrode was phosphorylated in the presence of CK2 and adenosine 5’-triphosphate,and then the phosphorylated peptide was integrated with the h-DNA/AuNPs/p-DNA through a process mediated by zirconium cations(Zr4+),and finally Ru(phen)32+ was intercalated into h-DNA.A "signal on" ECL method was developed for the detection of CK2 in the range of 0.005-0.2 U/mL with a detection limit of 0.001 U/mL.Additionally,combined efficient subcellular phosphorylation in vivo with bio-bar-code-based ECL biosensing method,the ECL method was further applied to monitor CK2 at subcellular level without tedious subcellular fractionation.It was found that the concentration of CK2 by inserting the peptide modified gold ultramicroelectrode into the nucleus was higher than that into cytoplasm of HeLa cells.A distinct heterogeneity among CK2 concentrations in single cells was observed for cellular heterogeneity assessment.
基金the National Natural Science Foundation of China (Nos. 21775097 and 21804106)the China Postdoctoral Science Foundation (No. 2017M620444)the Fundamental Research Funds for the Central Universities (Nos. XJJ2018247 and GK201801006)
文摘A highly selective and sensitive electrochemical method was developed for the detection of serotonin (5-hydroxytryptamine, 5-HT) at gold nanoflowers (Au NFs) and overoxidized polypyrrole (OPPy) modified carbon fiber microelectrode (CFME). Carbon fiber was firstly modified with gold nanoflowers using electroless deposition method, and then modified with overoxidized polypyrrole using electrochemical polymerization and overoxidization to obtain OPPy/Au NFs/CFME. The obtained OPPy/Au NFs/CFME was characterized by field emission scanning electron microscopy and electrochemical techniques. It was found that the OPPy/Au NFs/CFME showed good sensitivity for the detection of 5-HT in the range of 10 nmol/L-7.0μmol/L with detection limit of 2.3 nmol/L, and negligible interferences from ascorbic acid, 5-hydroxyindole acetic acid and uric acid. The OPPy/Au NFs/CFME was successfully applied to the detection of 5-HT in human serum samples with good recovery. The work demonstrates that the electrochemical method, incorporating signal amplification of Au NFs with higher cation selection of OPPy, provides a promising tool for the detection of 5-HT in biological systems.
基金supported by the National Natural Science Foundation of China(Nos.21173074 and 112074322)the Natural Science Foundation of Hunan Province(No.2018JJ2034)。
文摘Here we report an example of a general strategy for the immobilization of various different photochromic spiropyran molecules on eco-friendly cheap nanomatrix.The spiropyrans are encapsulated in calcium salt oligomers-based gels by centrifugation,forming an inorganic oligomer-based gelatinous photoswitchable hybrid material.Ca^(2+)is also used to regulate the optical properties of spiropyrans through chelation.The oligomer-based gel can not only provide the space required for photoisomerization,but also reduce the interference of the surrounding environment on the photochromic properties.Moreover,a practical paper-based and colloidal flexible substrate platform is constructed for the removal and naked-eye detection of liquid and gaseous hydrazine at room temperature based on the reactivity of the formyl group on spiro-pyrans loaded in Ca3(PO4)2 oligomers.This general strategy can be used for other inorganic oligomer-based molecular switches and sensing systems.
