To understand the mechanism of fluoride removal from the simulated zinc sulfate solution by the La(III)-modified zeolite,the adsorbent was characterized by XRD,SEM and EDS.The effects of absorbent dose and contact tim...To understand the mechanism of fluoride removal from the simulated zinc sulfate solution by the La(III)-modified zeolite,the adsorbent was characterized by XRD,SEM and EDS.The effects of absorbent dose and contact time,the adsorption isotherms and the sorption kinetics were investigated.The experimental results were compatible with the Langmuir isotherm model.The theoretical maximum adsorption capacities are 20.83 and 23.04 mg/g at 303 and 313 K,respectively.And the physisorption is revealed using the Temkin isotherm model and the D-R isotherm model.The sorption process is more suitable by the pseudo-second-order kinetic models.Thermodynamic parameters such as standard free energy change(ΔGΘ<0 kJ/mol),standard enthalpy change(ΔHΘ=8.28 kJ/mol)and standard entropy change(ΔSΘ=0.030 kJ/(mol?K))indicate the spontaneity of adsorption and endothermic physical sorption.Furthermore,the fluoride concentration in the industrial zinc sulfate solution decreases from 98.05 to 44.09 mg/L with the adsorbent dosage of 15 g/L.展开更多
The adsorption equilibrium of a fluoride solution on 1-2 mm granular activated alumina modified by Fe2(SO4)3 solution was investigated.The experiments were conducted using a wide range of initial fluoride concentratio...The adsorption equilibrium of a fluoride solution on 1-2 mm granular activated alumina modified by Fe2(SO4)3 solution was investigated.The experiments were conducted using a wide range of initial fluoride concentrations(0.5 to 180 mg·L-1 at pH～7.0) and an adsorbent dose of 1.0 g·L-1.The application of Langmuir and Freundlich adsorption isotherm models(linear and nonlinear forms) generally showed that a single Langmuir or Freundlich equation cannot fit the entire concentration gap.Experimental data on low equilibrium concentrations(0.1 to 5.0 mg·L-1) was in line with both Langmuir and Freundlich isotherm models,whereas that of high equilibrium concentrations(5.0 to 150 mg·L-1) was more in line with the Freundlich isotherm model.A new LangmuirFreundlich function was used for the entire concentration gap,as well as for low and high concentrations.展开更多
The ZrB 2 particles firstly modified Mg_(94)Zn_(2.5)Y_(2.5)Mn 1 alloy.And the microstructures and mechanical performances of the modified alloys were studied systematically.The results showed that the moderate additio...The ZrB 2 particles firstly modified Mg_(94)Zn_(2.5)Y_(2.5)Mn 1 alloy.And the microstructures and mechanical performances of the modified alloys were studied systematically.The results showed that the moderate addition of ZrB 2 accelerated the development of long-period stacking ordered(LPSO)structure and refined the grain size.The grains in ZrB 2-modified alloys were nearly equiaxed with a homogeneous size.When 0.0075 wt%ZrB 2 was added,the as-cast alloy with the finest grains(24.87μm)presented desirable mechanical properties(especially ductility)with maximum tensile strength and ductility of 225 MPa and 17.5%,respectively.展开更多
This work proved that biomass-based polyols (sorbitol, xylitol, erythritol, glycerol and ethanediol) were able to be converted into high-value chemical (p-xylene) by catalytic cracking of polyols, alkylation of aromat...This work proved that biomass-based polyols (sorbitol, xylitol, erythritol, glycerol and ethanediol) were able to be converted into high-value chemical (p-xylene) by catalytic cracking of polyols, alkylation of aromatics, and the isomerization of xylenes over the SiO2-modified zeolites. Compared to the conventional HZSM-5 zeolite, the SiO2-containing zeolites considerably increased the selectivity and yield of p-xylene due to the reduction of external surface acidity and the narrowing of pore entrance. The influences of the methanol additive, reaction temperature, and types of polyols on the selectivity and yield of p-xylene were investigated in detail. Catalytic cracking of polyols with methanol significantly enhanced the production of p-xylene by the alkylation of toluene with methanol. The highest p-xylene yield of 10.9 C-mol% with a p-xylene/xylenes ratio of 91.1% was obtained over the 15wt%SiO2/HZSM-5 catalyst. The reaction pathway for the formation of p-xylene was addressed according to the study of the key reactions and the characterization of catalysts.展开更多
We investigate the dielectric and ferroelectric properties of Sr1-xBixTi1-xFex03 solid solutions （x =0, 0.05, 0.1, 0.15 and 0.2） together with their structures. Through the analysis of Rietveld refinement of powder ...We investigate the dielectric and ferroelectric properties of Sr1-xBixTi1-xFex03 solid solutions （x =0, 0.05, 0.1, 0.15 and 0.2） together with their structures. Through the analysis of Rietveld refinement of powder x-ray diffraction, a cubic structure in space group Pm3m is determined for all the compositions. An obvious dielectric relaxation peak differing from SrTiO3 is observed in the present ceramics. The peak temperature Tm increases with increasing x, and it approaches room temperature at x =0.2. The Vogel Fulcher law and Curie Weiss law fittings further confirm the relaxor ferroelectricity in the present ceramics.展开更多
Na^(+)/K^(+)-ATPase is a transmembrane protein that has important roles in the maintenance of electrochemical gradients across cell membranes by transporting three Na^(+)out of and two K^(+)into cells.Additionally,Na^...Na^(+)/K^(+)-ATPase is a transmembrane protein that has important roles in the maintenance of electrochemical gradients across cell membranes by transporting three Na^(+)out of and two K^(+)into cells.Additionally,Na^(+)/K^(+)-ATPase participates in Ca^(2+)-signaling transduction and neurotransmitter release by coordinating the ion concentration gradient across the cell membrane.Na^(+)/K^(+)-ATPase works synergistically with multiple ion channels in the cell membrane to form a dynamic network of ion homeostatic regulation and affects cellular communication by regulating chemical signals and the ion balance among different types of cells.Therefo re,it is not surprising that Na^(+)/K^(+)-ATPase dysfunction has emerged as a risk factor for a variety of neurological diseases.However,published studies have so far only elucidated the important roles of Na^(+)/K^(+)-ATPase dysfunction in disease development,and we are lacking detailed mechanisms to clarify how Na^(+)/K^(+)-ATPase affects cell function.Our recent studies revealed that membrane loss of Na^(+)/K^(+)-ATPase is a key mechanism in many neurological disorders,particularly stroke and Parkinson's disease.Stabilization of plasma membrane Na^(+)/K^(+)-ATPase with an antibody is a novel strategy to treat these diseases.For this reason,Na^(+)/K^(+)-ATPase acts not only as a simple ion pump but also as a sensor/regulator or cytoprotective protein,participating in signal transduction such as neuronal autophagy and apoptosis,and glial cell migration.Thus,the present review attempts to summarize the novel biological functions of Na^(+)/K^(+)-ATPase and Na^(+)/K^(+)-ATPase-related pathogenesis.The potential for novel strategies to treat Na^(+)/K^(+)-ATPase-related brain diseases will also be discussed.展开更多
Sc and Zn were introduced into O3-NaMn_(0.5)Ni_(0.5)O_(2)(NaMN)using the combination of solution combustion and solid-state method.The effect of Sc and Zn dual-substitution on Na^(+) diffusion dynamics and structural ...Sc and Zn were introduced into O3-NaMn_(0.5)Ni_(0.5)O_(2)(NaMN)using the combination of solution combustion and solid-state method.The effect of Sc and Zn dual-substitution on Na^(+) diffusion dynamics and structural stability of NaMN was investigated.The physicochemical characterizations suggest that the introduction of Sc and Zn broaden Na^(+) diffusion channels and weaken the Na—O bonds,thereby facilitating the diffusion of sodium ions.Simulations indicate that the Sc and Zn dual-substitution decreases the diffusion barrier of Na-ions and improves the conductivity of the material.The dual-substituted NaMn_(0.5)Ni_(0.4)Sc_(0.04)Zn_(0.04)O_(2)(Na MNSZ44)cathode delivers impressive cycle stability with capacity retention of 71.2%after 200 cycles at 1C and 54.8%after 400 cycles at 5C.Additionally,the full cell paired with hard carbon anode exhibits a remarkable long-term cycling stability,showing capacity retention of 64.1%after 250 cycles at 1C.These results demonstrate that Sc and Zn dual-substitution is an effective strategy to improve the Na^(+) diffusion dynamics and structural stability of NaMN.展开更多
Magnesium ion batteries(MIBs)are a potential field for the energy storage of the future but are restricted by insufficient rate capability and rapid capacity degradation.Magnesium-sodium hybrid ion batteries(MSHBs)are...Magnesium ion batteries(MIBs)are a potential field for the energy storage of the future but are restricted by insufficient rate capability and rapid capacity degradation.Magnesium-sodium hybrid ion batteries(MSHBs)are an effective way to address these problems.Here,we report a new type of MSHBs that use layered sodium vanadate((Na,Mn)V_(8)O_(20)·5H_(2)O,Mn-NVO)cathodes coupled with an organic 3,4,9,10-perylenetetracarboxylic diimide(PTCDI)anode in Mg^(2+)/Na^(+)hybrid electrolytes.During electrochemical cycling,Mg^(2+)and Na^(+)co-participate in the cathode reactions,and the introduction of Na^(+)promotes the structural stability of the Mn-NVO cathode,as cleared by several ex-situ characterizations.Consequently,the Mn-NVO cathode presents great specific capacity(249.9 mA h g^(−1)at 300 mA g^(−1))and cycling(1500 cycles at 1500 mA g^(−1))in the Mg^(2+)/Na^(+)hybrid electrolytes.Besides,full battery displays long lifespan with 10,000 cycles at 1000 mA g^(−1).The rate performance and cycling stability of MSHBs have been improved by an economical and scalable method,and the mechanism for these improvements is discussed.展开更多
基金Projects(51474238,51674301)supported by the National Natural Science Foundation of China
文摘To understand the mechanism of fluoride removal from the simulated zinc sulfate solution by the La(III)-modified zeolite,the adsorbent was characterized by XRD,SEM and EDS.The effects of absorbent dose and contact time,the adsorption isotherms and the sorption kinetics were investigated.The experimental results were compatible with the Langmuir isotherm model.The theoretical maximum adsorption capacities are 20.83 and 23.04 mg/g at 303 and 313 K,respectively.And the physisorption is revealed using the Temkin isotherm model and the D-R isotherm model.The sorption process is more suitable by the pseudo-second-order kinetic models.Thermodynamic parameters such as standard free energy change(ΔGΘ<0 kJ/mol),standard enthalpy change(ΔHΘ=8.28 kJ/mol)and standard entropy change(ΔSΘ=0.030 kJ/(mol?K))indicate the spontaneity of adsorption and endothermic physical sorption.Furthermore,the fluoride concentration in the industrial zinc sulfate solution decreases from 98.05 to 44.09 mg/L with the adsorbent dosage of 15 g/L.
基金Supported by the Major National Science and Technology Special Project on Treatment and Control of Water Pollution(2009ZX07425-006)the State Key laboratory of Environmental Simulation and Pollution Control (09K04ESPCT)
文摘The adsorption equilibrium of a fluoride solution on 1-2 mm granular activated alumina modified by Fe2(SO4)3 solution was investigated.The experiments were conducted using a wide range of initial fluoride concentrations(0.5 to 180 mg·L-1 at pH～7.0) and an adsorbent dose of 1.0 g·L-1.The application of Langmuir and Freundlich adsorption isotherm models(linear and nonlinear forms) generally showed that a single Langmuir or Freundlich equation cannot fit the entire concentration gap.Experimental data on low equilibrium concentrations(0.1 to 5.0 mg·L-1) was in line with both Langmuir and Freundlich isotherm models,whereas that of high equilibrium concentrations(5.0 to 150 mg·L-1) was more in line with the Freundlich isotherm model.A new LangmuirFreundlich function was used for the entire concentration gap,as well as for low and high concentrations.
基金support of Shanxi key laboratory of advanced magnesium-based material,Na-tional Natural Science Foundation of China(No.51474153 and 51574175)Ph.D.Programs Foundation of Ministry of Education of China(20111402110004)。
文摘The ZrB 2 particles firstly modified Mg_(94)Zn_(2.5)Y_(2.5)Mn 1 alloy.And the microstructures and mechanical performances of the modified alloys were studied systematically.The results showed that the moderate addition of ZrB 2 accelerated the development of long-period stacking ordered(LPSO)structure and refined the grain size.The grains in ZrB 2-modified alloys were nearly equiaxed with a homogeneous size.When 0.0075 wt%ZrB 2 was added,the as-cast alloy with the finest grains(24.87μm)presented desirable mechanical properties(especially ductility)with maximum tensile strength and ductility of 225 MPa and 17.5%,respectively.
基金supported by the National Key R&D Program of China (No.2018YFB1501404)
文摘This work proved that biomass-based polyols (sorbitol, xylitol, erythritol, glycerol and ethanediol) were able to be converted into high-value chemical (p-xylene) by catalytic cracking of polyols, alkylation of aromatics, and the isomerization of xylenes over the SiO2-modified zeolites. Compared to the conventional HZSM-5 zeolite, the SiO2-containing zeolites considerably increased the selectivity and yield of p-xylene due to the reduction of external surface acidity and the narrowing of pore entrance. The influences of the methanol additive, reaction temperature, and types of polyols on the selectivity and yield of p-xylene were investigated in detail. Catalytic cracking of polyols with methanol significantly enhanced the production of p-xylene by the alkylation of toluene with methanol. The highest p-xylene yield of 10.9 C-mol% with a p-xylene/xylenes ratio of 91.1% was obtained over the 15wt%SiO2/HZSM-5 catalyst. The reaction pathway for the formation of p-xylene was addressed according to the study of the key reactions and the characterization of catalysts.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51332006,11274270,and 51272233
文摘We investigate the dielectric and ferroelectric properties of Sr1-xBixTi1-xFex03 solid solutions （x =0, 0.05, 0.1, 0.15 and 0.2） together with their structures. Through the analysis of Rietveld refinement of powder x-ray diffraction, a cubic structure in space group Pm3m is determined for all the compositions. An obvious dielectric relaxation peak differing from SrTiO3 is observed in the present ceramics. The peak temperature Tm increases with increasing x, and it approaches room temperature at x =0.2. The Vogel Fulcher law and Curie Weiss law fittings further confirm the relaxor ferroelectricity in the present ceramics.
基金supported by the National Natural Science Foundation of China,No.82173800 (to JB)Shenzhen Science and Technology Program,No.KQTD20200820113040070 (to JB)。
文摘Na^(+)/K^(+)-ATPase is a transmembrane protein that has important roles in the maintenance of electrochemical gradients across cell membranes by transporting three Na^(+)out of and two K^(+)into cells.Additionally,Na^(+)/K^(+)-ATPase participates in Ca^(2+)-signaling transduction and neurotransmitter release by coordinating the ion concentration gradient across the cell membrane.Na^(+)/K^(+)-ATPase works synergistically with multiple ion channels in the cell membrane to form a dynamic network of ion homeostatic regulation and affects cellular communication by regulating chemical signals and the ion balance among different types of cells.Therefo re,it is not surprising that Na^(+)/K^(+)-ATPase dysfunction has emerged as a risk factor for a variety of neurological diseases.However,published studies have so far only elucidated the important roles of Na^(+)/K^(+)-ATPase dysfunction in disease development,and we are lacking detailed mechanisms to clarify how Na^(+)/K^(+)-ATPase affects cell function.Our recent studies revealed that membrane loss of Na^(+)/K^(+)-ATPase is a key mechanism in many neurological disorders,particularly stroke and Parkinson's disease.Stabilization of plasma membrane Na^(+)/K^(+)-ATPase with an antibody is a novel strategy to treat these diseases.For this reason,Na^(+)/K^(+)-ATPase acts not only as a simple ion pump but also as a sensor/regulator or cytoprotective protein,participating in signal transduction such as neuronal autophagy and apoptosis,and glial cell migration.Thus,the present review attempts to summarize the novel biological functions of Na^(+)/K^(+)-ATPase and Na^(+)/K^(+)-ATPase-related pathogenesis.The potential for novel strategies to treat Na^(+)/K^(+)-ATPase-related brain diseases will also be discussed.
基金financial support from the National Natural Science Foundation of China(No.52377220)the Natural Science Foundation of Hunan Province,China(No.kq2208265)。
文摘Sc and Zn were introduced into O3-NaMn_(0.5)Ni_(0.5)O_(2)(NaMN)using the combination of solution combustion and solid-state method.The effect of Sc and Zn dual-substitution on Na^(+) diffusion dynamics and structural stability of NaMN was investigated.The physicochemical characterizations suggest that the introduction of Sc and Zn broaden Na^(+) diffusion channels and weaken the Na—O bonds,thereby facilitating the diffusion of sodium ions.Simulations indicate that the Sc and Zn dual-substitution decreases the diffusion barrier of Na-ions and improves the conductivity of the material.The dual-substituted NaMn_(0.5)Ni_(0.4)Sc_(0.04)Zn_(0.04)O_(2)(Na MNSZ44)cathode delivers impressive cycle stability with capacity retention of 71.2%after 200 cycles at 1C and 54.8%after 400 cycles at 5C.Additionally,the full cell paired with hard carbon anode exhibits a remarkable long-term cycling stability,showing capacity retention of 64.1%after 250 cycles at 1C.These results demonstrate that Sc and Zn dual-substitution is an effective strategy to improve the Na^(+) diffusion dynamics and structural stability of NaMN.
基金the financial support from the National Natural Science Foundation of China, China (22005207, 52261160384)the Guangdong Basic and Applied Basic Research Foundation, Guangdong Province, China (2019A1515011819)+2 种基金the Outstanding Youth Basic Research Project of Shenzhen, Shenzhen, China (RCYX20221008092934093)the Joint Funds of the National Natural Science Foundation of China, China (U22A20140)the Science and Technology Development Fund, Macao SAR (0090/2021/A2 and 0049/2021/AGJ)
文摘Magnesium ion batteries(MIBs)are a potential field for the energy storage of the future but are restricted by insufficient rate capability and rapid capacity degradation.Magnesium-sodium hybrid ion batteries(MSHBs)are an effective way to address these problems.Here,we report a new type of MSHBs that use layered sodium vanadate((Na,Mn)V_(8)O_(20)·5H_(2)O,Mn-NVO)cathodes coupled with an organic 3,4,9,10-perylenetetracarboxylic diimide(PTCDI)anode in Mg^(2+)/Na^(+)hybrid electrolytes.During electrochemical cycling,Mg^(2+)and Na^(+)co-participate in the cathode reactions,and the introduction of Na^(+)promotes the structural stability of the Mn-NVO cathode,as cleared by several ex-situ characterizations.Consequently,the Mn-NVO cathode presents great specific capacity(249.9 mA h g^(−1)at 300 mA g^(−1))and cycling(1500 cycles at 1500 mA g^(−1))in the Mg^(2+)/Na^(+)hybrid electrolytes.Besides,full battery displays long lifespan with 10,000 cycles at 1000 mA g^(−1).The rate performance and cycling stability of MSHBs have been improved by an economical and scalable method,and the mechanism for these improvements is discussed.
