Developing efficient energy storage for sodium-ion batteries(SIBs)by creating high-performance heterojunctions and understanding their interfacial interaction at the atomic/molecular level holds promise but is also ch...Developing efficient energy storage for sodium-ion batteries(SIBs)by creating high-performance heterojunctions and understanding their interfacial interaction at the atomic/molecular level holds promise but is also challenging.Besides,sluggish reaction kinetics at low temperatures restrict the operation of SIBs in cold climates.Herein,cross-linking nanoarchitectonics of WS_(2)/Ti_(3)C_(2)T_(x) heterojunction,featuring built-in electric field(BIEF),have been developed,employing as a model to reveal the positive effect of heterojunction design and BIEF for modifying the reaction kinetics and electrochemical activity.Particularly,the theoretical analysis manifests the discrepancy in work functions leads to the electronic flow from the electron-rich Ti_(3)C_(2)T_(x) to layered WS_(2),spontaneously forming the BIEF and“ion reservoir”at the heterogeneous interface.Besides,the generation of cross-linking pathways further promotes the transportation of electrons/ions,which guarantees rapid diffusion kinetics and excellent structure coupling.Consequently,superior sodium storage performance is obtained for the WS_(2)/Ti_(3)C_(2)T_(x) heterojunction,with only 0.2%decay per cycle at 5.0 A g^(-1)(25℃)up to 1000 cycles and a high capacity of 293.5 mA h g^(-1)(0.1A g^(-1)after 100 cycles)even at-20℃.Importantly,the spontaneously formed BIEF,accompanied by“ion reservoir”,in heterojunction provides deep understandings of the correlation between structure fabricated and performance obtained.展开更多
The combined effects of salinity with low root zone temperature(RZT) on plant growth and photosynthesis were studied in tomato(Solanum lycopersicum) plants.The plants were exposed to two different root zone temperatur...The combined effects of salinity with low root zone temperature(RZT) on plant growth and photosynthesis were studied in tomato(Solanum lycopersicum) plants.The plants were exposed to two different root zone temperatures(28/20 C,12/8 C,day/night temperature) in combination with two NaCl levels(0 and 100 mmol L-1).After 2 wk of treatment,K+and Na+concentration,leaf photosynthetic gas exchange,chlorophyll fluorescence and leaf antioxidant enzyme activities were measured.Salinity significantly decreased plant biomass,net photosynthesis rate,actual quantum yield of photosynthesis and concentration of K+,but remarkably increased the concentration of Na+.These effects were more pronounced when the salinity treatments were combined with the treatment of low RZT conditions.Either salinity or low RZT individually did not affect maximal efficiency of PSII photochemistry(Fv/Fm),while a combination of these two stresses decreased Fv/Fm considerably,indicating that the photo-damage occurred under such conditions.Non-photochemical quenching was increased by salt stress in accompany with the enhancement of the de-epoxidation state of the xanthophyll cycle,in contrast,this was not the case with low RZT applied individually.Salinity stress individually increased the activities of SOD,APX,GPOD and GR,and decreased the activities of DHAR.Due to the interactive effects of salinity with low RZT,these five enzyme activities increased sharply in the combined stressed plants.These results indicate that low RZT exacerbates the ion imbalance,PSII damage and photosynthesis inhibition in tomato plants under salinity.In response to the oxidative stress under salinity in combination with low RZT,the activities of antioxidant enzymes SOD,APX,GPOD,DHAR and GR were clearly enhanced in tomato plants.展开更多
A new preparation method for a highly sinterable Y 2O 3 powder was developed, using the mixture of the powder with Al 2O 3 powder, a transparent yttrium aluminum garnet(YAG) ceramic was prepared at relatively low temp...A new preparation method for a highly sinterable Y 2O 3 powder was developed, using the mixture of the powder with Al 2O 3 powder, a transparent yttrium aluminum garnet(YAG) ceramic was prepared at relatively low temperature by a solid state reaction method. Yttrium nitrate was used as a mother salt, and aqueous ammonia was used as a precipitant reagent, the fine and dendritic precursor crystalline was prepared by adding 0.5% ammonium sulfate into the precipitation reaction system. The highly pure and low agglomerated Y 2O 3 powders were obtained by calcinating the precursor at 1 100 ℃, the primary particles are spherical and 60 nm in diameter. The mixture of Y 2O 3 and Al 2O 3 powders was calcinated, and the resulting mixture compact pressed in mold could be sintered to transparency under vacuum at 1 700 ℃. The sintered transparent YAG polycrystalline exhibits a homogeneous microstructure and its transmittance reaches 45% in the visible light region and 70% in the near infrared wavelength region.展开更多
This paper deals with the profile measurement of impurity ion temperature and toroidal rotation velocity that can be achieved by using the charge exchange recombination spectrum(CXRS) diagnostics tool built on the HL-...This paper deals with the profile measurement of impurity ion temperature and toroidal rotation velocity that can be achieved by using the charge exchange recombination spectrum(CXRS) diagnostics tool built on the HL-2A tokamak.By using CXRS,an accurate impurity ion temperature and toroidal plasma rotation velocity profile can be achieved under the condition of neutral beam injection(NBI) heating.Considering the edge effect of the line of CVI 529.06 nm(n = 8～7),which contains three lines(active exciting spectral line(ACX),passivity exciting spectral line(PCX) and electron exciting spectral line(ICE)),and using three Gaussian fitted curves,we obtain the following experimental results:the core ion temperature of HL-2A device is nearly thousands of eV,and the plasma rotation velocity reaches about 10 4 m·s-1.At the end of paper,some explanations are presented for the relationship between the curves and the inner physical mechanism.展开更多
The changes of plasmalemma permeability and some primary inorganic ions of Antarctic ice microalgae (Chlamydomonas sp. ICE-L) in the low-temperature stress were examined. The plasmalemma of ICE-L could maintain the st...The changes of plasmalemma permeability and some primary inorganic ions of Antarctic ice microalgae (Chlamydomonas sp. ICE-L) in the low-temperature stress were examined. The plasmalemma of ICE-L could maintain the stability at the freezing condition of -6 ℃. That signifies that it could maintain the proper function of plasmalemma and stability of the intracellular environment during sea ice formation. The function of inorganic ions on low-temperature adaptation of ICE-L was investigated by using the X-ray microanalysis method. Low temperature (0～ -6 ℃) induces Ca~ 2+ concentration increment of cytoplasm, but after 24 h the content decrease quickly to normal value. As a matter of fact, Ca~ 2+ plays an important role as the second messenger in the low temperature adaptation of ICE-L. In addition, low temperature also influences on the other primary inorganic ions transfer and the cell maintains activity by keeping ratio balance among different ions. Above all, it is necessary for Antarctic ice microalgae to survive and breed by maintaining the stability of K^+ content and the balance of Na^+/Cl^-.展开更多
Magnesium-lithium hybrid ion batteries have emerged as a new class of energy storage systems owing to dendrite free cycling of magnesium anode and possibility of practice of numerous conventional lithium cathodes.In p...Magnesium-lithium hybrid ion batteries have emerged as a new class of energy storage systems owing to dendrite free cycling of magnesium anode and possibility of practice of numerous conventional lithium cathodes.In present work,we used hybrid ion strategy to analyze the performance of lithium titanate based lithium cathode,magnesium metal anode,and all-phenyl complex(APC)electrolytes at different temperatures(25℃,10℃,0℃,-10℃,and-20℃).The hybrid ion battery exhibited excellent rate performance(228 m Ah g^(-1)/20 m A g^(-1) and 163 mAh g^(-1)/1000 mA g^(-1))with stable voltage plateaus at 0.90 and 0.75 V,which corresponds to specific energy of 178 Wh kg^(-1) at room temperature(25℃).Experimental results revealed that APC-THF solutions have strong potential to suppress the freezing of electrolyte solutions owing to low boiling point of THF.The low temperature electrochemical testing revealed the reversible capacities of 213.4,165.5,143.8,133.2 and 78.56 mAh g^(-1) at 25,10,0,-10,and-20℃,respectively.Furthermore,ex-situ XRD,SEM,and EIS tests were carried out to understand the reaction kinetics of both Mg2+and Li+ions inside the lithium titanate cathode.We hope this work will shed light on low temperature prospective of electrochemical devices for use in cold environments.展开更多
In this paper, we report a method by which the ion quantity is estimated rapidly with an accuracy of 4%. This finding is based on the low-temperature ion density theory and combined with the ion crystal size obtained ...In this paper, we report a method by which the ion quantity is estimated rapidly with an accuracy of 4%. This finding is based on the low-temperature ion density theory and combined with the ion crystal size obtained from experiment with the precision of a micrometer. The method is objective, straightforward, and independent of the molecular dynamics(MD)simulation. The result can be used as the reference for the MD simulation, and the method can improve the reliability and precision of MD simulation. This method is very helpful for intensively studying ion crystal, such as phase transition,spatial configuration, temporal evolution, dynamic character, cooling efficiency, and the temperature limit of the ions.展开更多
Rechargeable aqueous Zn-ion batteries (ZIBs) have attracted great attention due to their costeffectiveness,high safety,and environmental friendliness.However,some issues associated with poor structural instability of ...Rechargeable aqueous Zn-ion batteries (ZIBs) have attracted great attention due to their costeffectiveness,high safety,and environmental friendliness.However,some issues associated with poor structural instability of cathode materials and fast self-discharge hinder the further development of ZIBs.Herein,a new configuration is introduced by placing a reduced graphene oxide film as a block layer between the separator and the V2O5·nH2O cathode.This layer prevents the free diffusion of dissolved active materials to the anode and facilitates the transport of Zn ion and electrons,largely improving the cyclic stability and alleviating the self-discharge.Accordingly,the optimized battery delivers a remarkable capacity of 191 mAh g^-1 after 500 cycles at 2 A g^-1.Moreover,a high capacity of 106 mAh g^-1 is achieved after 100 cycles at-20℃.The strategy proposed is expected to be applicable to other electrode systems,thus offering a new approach to circumvent the critical challenges facing aqueous batteries.展开更多
Polytetrafluoroethylene(PTFE)is a low-background polymer that is applied to several applications in rare-event detection and underground low-background experiments.PTFE-based electronic substrates are important for re...Polytetrafluoroethylene(PTFE)is a low-background polymer that is applied to several applications in rare-event detection and underground low-background experiments.PTFE-based electronic substrates are important for reducing the detection limit of high-purity germanium detectors and scintillator calorimeters,which are widely applied in dark matter and 0υββdetection experiments.The traditional adhesive bonding method between PTFE and copper is not conducive to working in liquid nitrogen and extremely low-temperature environments.To avoid adhesive bonding,PTFE must be processed for surface metallization owing to the mismatch between the PTFE and copper conductive layer.Low-background PTFE matrix composites(m-PTFE)were selected to improve the electrical and mechanical properties of PTFE by introducing SiO_(2)/TiO_(2) particles.The microstructures,surface elements,and electrical properties of PTFE and m-PTFE were characterized and analyzed following ion implantation.PTFE and m-PTFE surfaces were found to be broken,degraded,and cross-linked by ion implantation,resulting in C=C conjugated double bonds,increased surface energy,and increased surface roughness.Comparably,the surface roughness,bond strength,and conjugated double bonds of m-PTFE were significantly more intense than those of PTFE.Moreover,the interface bonding theory between PTFE and the metal copper foil was analyzed using the direct metallization principle.Therefore,the peel strength of the optimized electronic substrates was higher than that of the industrial standard at extremely low temperatures,while maintaining excellent electrical properties.展开更多
The ion exchange resin Amberlite IRA-400 in iodide and bromide form where equilibrated separately with the respective labeled iodide and bromide ion solution of different concen-trations varying from 0.005M to 0.100M ...The ion exchange resin Amberlite IRA-400 in iodide and bromide form where equilibrated separately with the respective labeled iodide and bromide ion solution of different concen-trations varying from 0.005M to 0.100M in the temperature range of 32.0 oC to 48.0 oC. The dis-tribution coefficient Kd values calculated for iodide and bromide ion exchange increases with rise in ionic concentration of the external solution, however with rise in temperature the Kd values calculated where found to decrease. Also the Kd values calculated where higher for iodide exchange than bromide exchange. Among the different alternative techniques available for obtaining the Kd values, the radio-active tracer technique used in the present ex-perimental work offers high detection sensitivity. It is expected that the distribution coefficient data obtained from such experimental work will significant in environmental impact assessment on the disposal of radioactive waste.展开更多
(Ba0.66Sr0.33)Mg0.8Al11.47O19:Tm0.013+(BSMA:Tm3+) phosphor was synthesized by solid-state reactions. The sample was characterized by X-ray diffraction (XRD), scanning electronic microscope (SEM), vacuum ultraviolet (V...(Ba0.66Sr0.33)Mg0.8Al11.47O19:Tm0.013+(BSMA:Tm3+) phosphor was synthesized by solid-state reactions. The sample was characterized by X-ray diffraction (XRD), scanning electronic microscope (SEM), vacuum ultraviolet (VUV) spectra, ultraviolet (UV) spectra and FT-IR spectrum. XRD pattern reveals that BSMA:Tm3+ has the same structure as BaAl12O19 phase. SEM image illustrates that the phosphor has the hexagonal shape and deep slice structure. VUV and UV emission spectra at 20, 50 and 100 K show that the low temperature luminescence intensities become weak gradually with the increasing of the temperature under 147 and 254 nm excitation. The strong broadband peaks at around 357 and 397 nm and the peak at 516 nm under 147 nm excitation all correspond to the characteristic transitions of Tm3+ ions. However, under UV (254 nm) excitation, the main peak becomes 530 nm which has very high line intensity, and the peaks at about 362 and 403 nm are very weak. The excitation spectrum at 20 K shows that there are three absorption peaks at around 153, 186 and 193 nm when 516 nm emission is monitored. The absorption peaks of [AlO4], [AlO6] and Al-O can be observed in FT-IR spectrum.展开更多
Low temperature plasma was used to treat sludge,and the effects of discharge time on the content of different forms of heavy metals in the sludge were studied. The results showed that Cu and Zn content in the domestic...Low temperature plasma was used to treat sludge,and the effects of discharge time on the content of different forms of heavy metals in the sludge were studied. The results showed that Cu and Zn content in the domestic sludge could basically meet the requirements of GB 4284-2018,GB/T 23486-2009,CJ/T 362-2011 and CJ/T 309-2009. There were big differences between different forms of the heavy metals. According to the proportions of different forms of Cu in the sludge,different forms of Cu are arranged as follows: organic state > carbonate bound state> residual state > exchangeable state > iron-manganese oxidation state,and Cu mainly existed in an organic state. Various forms of Zn are arranged in order of the proportion as follows: iron-manganese oxidation state > residual state > carbonate bound state > exchangeable state > organic state,and Zn mainly existed in an iron-manganese oxidation state. After the treatment of sludge by low temperature plasma,the content of exchangeable Cu and Zn in the sludge increased,while the content and proportion of residual Cu and Zn all reduced.展开更多
Characteristics of ion temperature measured with charge-exchange recombinationspectroscopy （CXRS） were studied in Ohmic,lower-hybrid-wave （LHW） driven and ion-cyclotron-resonance-frequency （ICRF） heated plasmas ...Characteristics of ion temperature measured with charge-exchange recombinationspectroscopy （CXRS） were studied in Ohmic,lower-hybrid-wave （LHW） driven and ion-cyclotron-resonance-frequency （ICRF） heated plasmas in HT-7.The results indicate that the central iontemperature Ti0 follows the one-third power law in the product of central line-averaged densityne and plasma current Ip in Ohmic discharges and is therefore consistent with the Artsimovichscaling law Ti0 = K· （Ip· Bt·ne · R2）1/3.It is shown that there is an appreciable increase ofion temperature during the operation with both LHW and ICRF and that the increment of iontemperature in those shots is mainly due to the energy transfer via collisions between ions andelectrons rather that by direct heating of the ions.展开更多
基金supported by the faculty startup funds from the Yangzhou Universitythe Natural Science Foundation of Jiangsu Province(BK20210821)+1 种基金the National Natural Science Foundation of China(22102141)the Lvyangjinfeng Talent Program of Yangzhou。
文摘Developing efficient energy storage for sodium-ion batteries(SIBs)by creating high-performance heterojunctions and understanding their interfacial interaction at the atomic/molecular level holds promise but is also challenging.Besides,sluggish reaction kinetics at low temperatures restrict the operation of SIBs in cold climates.Herein,cross-linking nanoarchitectonics of WS_(2)/Ti_(3)C_(2)T_(x) heterojunction,featuring built-in electric field(BIEF),have been developed,employing as a model to reveal the positive effect of heterojunction design and BIEF for modifying the reaction kinetics and electrochemical activity.Particularly,the theoretical analysis manifests the discrepancy in work functions leads to the electronic flow from the electron-rich Ti_(3)C_(2)T_(x) to layered WS_(2),spontaneously forming the BIEF and“ion reservoir”at the heterogeneous interface.Besides,the generation of cross-linking pathways further promotes the transportation of electrons/ions,which guarantees rapid diffusion kinetics and excellent structure coupling.Consequently,superior sodium storage performance is obtained for the WS_(2)/Ti_(3)C_(2)T_(x) heterojunction,with only 0.2%decay per cycle at 5.0 A g^(-1)(25℃)up to 1000 cycles and a high capacity of 293.5 mA h g^(-1)(0.1A g^(-1)after 100 cycles)even at-20℃.Importantly,the spontaneously formed BIEF,accompanied by“ion reservoir”,in heterojunction provides deep understandings of the correlation between structure fabricated and performance obtained.
基金supported by the National Natural Science Foundation of China(31101585)the Cucurbit Vegetable Innovation Strategic Alliance Fund of Zhejiang Province,China(20101107)+1 种基金the Vegetable Innovation Group Fund of Zhejiang Province,China(2009R50026)the Zhejiang A&F University Science Development Fund,China(2009FR059)
文摘The combined effects of salinity with low root zone temperature(RZT) on plant growth and photosynthesis were studied in tomato(Solanum lycopersicum) plants.The plants were exposed to two different root zone temperatures(28/20 C,12/8 C,day/night temperature) in combination with two NaCl levels(0 and 100 mmol L-1).After 2 wk of treatment,K+and Na+concentration,leaf photosynthetic gas exchange,chlorophyll fluorescence and leaf antioxidant enzyme activities were measured.Salinity significantly decreased plant biomass,net photosynthesis rate,actual quantum yield of photosynthesis and concentration of K+,but remarkably increased the concentration of Na+.These effects were more pronounced when the salinity treatments were combined with the treatment of low RZT conditions.Either salinity or low RZT individually did not affect maximal efficiency of PSII photochemistry(Fv/Fm),while a combination of these two stresses decreased Fv/Fm considerably,indicating that the photo-damage occurred under such conditions.Non-photochemical quenching was increased by salt stress in accompany with the enhancement of the de-epoxidation state of the xanthophyll cycle,in contrast,this was not the case with low RZT applied individually.Salinity stress individually increased the activities of SOD,APX,GPOD and GR,and decreased the activities of DHAR.Due to the interactive effects of salinity with low RZT,these five enzyme activities increased sharply in the combined stressed plants.These results indicate that low RZT exacerbates the ion imbalance,PSII damage and photosynthesis inhibition in tomato plants under salinity.In response to the oxidative stress under salinity in combination with low RZT,the activities of antioxidant enzymes SOD,APX,GPOD,DHAR and GR were clearly enhanced in tomato plants.
文摘A new preparation method for a highly sinterable Y 2O 3 powder was developed, using the mixture of the powder with Al 2O 3 powder, a transparent yttrium aluminum garnet(YAG) ceramic was prepared at relatively low temperature by a solid state reaction method. Yttrium nitrate was used as a mother salt, and aqueous ammonia was used as a precipitant reagent, the fine and dendritic precursor crystalline was prepared by adding 0.5% ammonium sulfate into the precipitation reaction system. The highly pure and low agglomerated Y 2O 3 powders were obtained by calcinating the precursor at 1 100 ℃, the primary particles are spherical and 60 nm in diameter. The mixture of Y 2O 3 and Al 2O 3 powders was calcinated, and the resulting mixture compact pressed in mold could be sintered to transparency under vacuum at 1 700 ℃. The sintered transparent YAG polycrystalline exhibits a homogeneous microstructure and its transmittance reaches 45% in the visible light region and 70% in the near infrared wavelength region.
基金supported by ITER Research Project of China Matched Program (No.2009GB107004)the Fundamental Research Funds for the Central Universities of China (No.ZYGX2010J056)Natural Natural Science Foundation of China (No.11205027)
文摘This paper deals with the profile measurement of impurity ion temperature and toroidal rotation velocity that can be achieved by using the charge exchange recombination spectrum(CXRS) diagnostics tool built on the HL-2A tokamak.By using CXRS,an accurate impurity ion temperature and toroidal plasma rotation velocity profile can be achieved under the condition of neutral beam injection(NBI) heating.Considering the edge effect of the line of CVI 529.06 nm(n = 8～7),which contains three lines(active exciting spectral line(ACX),passivity exciting spectral line(PCX) and electron exciting spectral line(ICE)),and using three Gaussian fitted curves,we obtain the following experimental results:the core ion temperature of HL-2A device is nearly thousands of eV,and the plasma rotation velocity reaches about 10 4 m·s-1.At the end of paper,some explanations are presented for the relationship between the curves and the inner physical mechanism.
文摘The changes of plasmalemma permeability and some primary inorganic ions of Antarctic ice microalgae (Chlamydomonas sp. ICE-L) in the low-temperature stress were examined. The plasmalemma of ICE-L could maintain the stability at the freezing condition of -6 ℃. That signifies that it could maintain the proper function of plasmalemma and stability of the intracellular environment during sea ice formation. The function of inorganic ions on low-temperature adaptation of ICE-L was investigated by using the X-ray microanalysis method. Low temperature (0～ -6 ℃) induces Ca~ 2+ concentration increment of cytoplasm, but after 24 h the content decrease quickly to normal value. As a matter of fact, Ca~ 2+ plays an important role as the second messenger in the low temperature adaptation of ICE-L. In addition, low temperature also influences on the other primary inorganic ions transfer and the cell maintains activity by keeping ratio balance among different ions. Above all, it is necessary for Antarctic ice microalgae to survive and breed by maintaining the stability of K^+ content and the balance of Na^+/Cl^-.
基金JUST Research Start-Up Fund(1062921905)supported。
文摘Magnesium-lithium hybrid ion batteries have emerged as a new class of energy storage systems owing to dendrite free cycling of magnesium anode and possibility of practice of numerous conventional lithium cathodes.In present work,we used hybrid ion strategy to analyze the performance of lithium titanate based lithium cathode,magnesium metal anode,and all-phenyl complex(APC)electrolytes at different temperatures(25℃,10℃,0℃,-10℃,and-20℃).The hybrid ion battery exhibited excellent rate performance(228 m Ah g^(-1)/20 m A g^(-1) and 163 mAh g^(-1)/1000 mA g^(-1))with stable voltage plateaus at 0.90 and 0.75 V,which corresponds to specific energy of 178 Wh kg^(-1) at room temperature(25℃).Experimental results revealed that APC-THF solutions have strong potential to suppress the freezing of electrolyte solutions owing to low boiling point of THF.The low temperature electrochemical testing revealed the reversible capacities of 213.4,165.5,143.8,133.2 and 78.56 mAh g^(-1) at 25,10,0,-10,and-20℃,respectively.Furthermore,ex-situ XRD,SEM,and EIS tests were carried out to understand the reaction kinetics of both Mg2+and Li+ions inside the lithium titanate cathode.We hope this work will shed light on low temperature prospective of electrochemical devices for use in cold environments.
基金supported by the National Basic Research Program of China(Grant Nos.2012CB821301 and 2010CB832803)the National Natural Science Foundation of China(Grant Nos.11004222 and 91121016)the Chinese Academy of Sciences
文摘In this paper, we report a method by which the ion quantity is estimated rapidly with an accuracy of 4%. This finding is based on the low-temperature ion density theory and combined with the ion crystal size obtained from experiment with the precision of a micrometer. The method is objective, straightforward, and independent of the molecular dynamics(MD)simulation. The result can be used as the reference for the MD simulation, and the method can improve the reliability and precision of MD simulation. This method is very helpful for intensively studying ion crystal, such as phase transition,spatial configuration, temporal evolution, dynamic character, cooling efficiency, and the temperature limit of the ions.
基金financially supported by the Hong Kong Polytechnic University(Grant 1-ZE83,Area of Excellence Project 1ZE30)。
文摘Rechargeable aqueous Zn-ion batteries (ZIBs) have attracted great attention due to their costeffectiveness,high safety,and environmental friendliness.However,some issues associated with poor structural instability of cathode materials and fast self-discharge hinder the further development of ZIBs.Herein,a new configuration is introduced by placing a reduced graphene oxide film as a block layer between the separator and the V2O5·nH2O cathode.This layer prevents the free diffusion of dissolved active materials to the anode and facilitates the transport of Zn ion and electrons,largely improving the cyclic stability and alleviating the self-discharge.Accordingly,the optimized battery delivers a remarkable capacity of 191 mAh g^-1 after 500 cycles at 2 A g^-1.Moreover,a high capacity of 106 mAh g^-1 is achieved after 100 cycles at-20℃.The strategy proposed is expected to be applicable to other electrode systems,thus offering a new approach to circumvent the critical challenges facing aqueous batteries.
基金supported by the National Natural Science Foundation of China(Nos.12141502 and 12005017).
文摘Polytetrafluoroethylene(PTFE)is a low-background polymer that is applied to several applications in rare-event detection and underground low-background experiments.PTFE-based electronic substrates are important for reducing the detection limit of high-purity germanium detectors and scintillator calorimeters,which are widely applied in dark matter and 0υββdetection experiments.The traditional adhesive bonding method between PTFE and copper is not conducive to working in liquid nitrogen and extremely low-temperature environments.To avoid adhesive bonding,PTFE must be processed for surface metallization owing to the mismatch between the PTFE and copper conductive layer.Low-background PTFE matrix composites(m-PTFE)were selected to improve the electrical and mechanical properties of PTFE by introducing SiO_(2)/TiO_(2) particles.The microstructures,surface elements,and electrical properties of PTFE and m-PTFE were characterized and analyzed following ion implantation.PTFE and m-PTFE surfaces were found to be broken,degraded,and cross-linked by ion implantation,resulting in C=C conjugated double bonds,increased surface energy,and increased surface roughness.Comparably,the surface roughness,bond strength,and conjugated double bonds of m-PTFE were significantly more intense than those of PTFE.Moreover,the interface bonding theory between PTFE and the metal copper foil was analyzed using the direct metallization principle.Therefore,the peel strength of the optimized electronic substrates was higher than that of the industrial standard at extremely low temperatures,while maintaining excellent electrical properties.
文摘The ion exchange resin Amberlite IRA-400 in iodide and bromide form where equilibrated separately with the respective labeled iodide and bromide ion solution of different concen-trations varying from 0.005M to 0.100M in the temperature range of 32.0 oC to 48.0 oC. The dis-tribution coefficient Kd values calculated for iodide and bromide ion exchange increases with rise in ionic concentration of the external solution, however with rise in temperature the Kd values calculated where found to decrease. Also the Kd values calculated where higher for iodide exchange than bromide exchange. Among the different alternative techniques available for obtaining the Kd values, the radio-active tracer technique used in the present ex-perimental work offers high detection sensitivity. It is expected that the distribution coefficient data obtained from such experimental work will significant in environmental impact assessment on the disposal of radioactive waste.
基金Project supported by MOST of China (2006CB601104)Synchrotron Radiation Fund of Innovation Project of Ministry of Education (20041213S)
文摘(Ba0.66Sr0.33)Mg0.8Al11.47O19:Tm0.013+(BSMA:Tm3+) phosphor was synthesized by solid-state reactions. The sample was characterized by X-ray diffraction (XRD), scanning electronic microscope (SEM), vacuum ultraviolet (VUV) spectra, ultraviolet (UV) spectra and FT-IR spectrum. XRD pattern reveals that BSMA:Tm3+ has the same structure as BaAl12O19 phase. SEM image illustrates that the phosphor has the hexagonal shape and deep slice structure. VUV and UV emission spectra at 20, 50 and 100 K show that the low temperature luminescence intensities become weak gradually with the increasing of the temperature under 147 and 254 nm excitation. The strong broadband peaks at around 357 and 397 nm and the peak at 516 nm under 147 nm excitation all correspond to the characteristic transitions of Tm3+ ions. However, under UV (254 nm) excitation, the main peak becomes 530 nm which has very high line intensity, and the peaks at about 362 and 403 nm are very weak. The excitation spectrum at 20 K shows that there are three absorption peaks at around 153, 186 and 193 nm when 516 nm emission is monitored. The absorption peaks of [AlO4], [AlO6] and Al-O can be observed in FT-IR spectrum.
基金Supported by International Science&Technology Cooperation Program of China(2015DFR70390)Science and Technology Platform and Base Construction Project of Chongqing City,China(cstc2014gjhz20001)Science and Technology Planning Project of Chongqing City,China(cstc2011pt-gc80019)
文摘Low temperature plasma was used to treat sludge,and the effects of discharge time on the content of different forms of heavy metals in the sludge were studied. The results showed that Cu and Zn content in the domestic sludge could basically meet the requirements of GB 4284-2018,GB/T 23486-2009,CJ/T 362-2011 and CJ/T 309-2009. There were big differences between different forms of the heavy metals. According to the proportions of different forms of Cu in the sludge,different forms of Cu are arranged as follows: organic state > carbonate bound state> residual state > exchangeable state > iron-manganese oxidation state,and Cu mainly existed in an organic state. Various forms of Zn are arranged in order of the proportion as follows: iron-manganese oxidation state > residual state > carbonate bound state > exchangeable state > organic state,and Zn mainly existed in an iron-manganese oxidation state. After the treatment of sludge by low temperature plasma,the content of exchangeable Cu and Zn in the sludge increased,while the content and proportion of residual Cu and Zn all reduced.
基金supported by the Instruments R&D Project of the Chinese Academy of Sciences (title: Active Beam Spectra Diagnostic)partially supported by National Natural Science Foundation of China (Nos. 10725523, 10975155)the ITER Relevant Foundation in China(No. 2009GB104003)
文摘Characteristics of ion temperature measured with charge-exchange recombinationspectroscopy （CXRS） were studied in Ohmic,lower-hybrid-wave （LHW） driven and ion-cyclotron-resonance-frequency （ICRF） heated plasmas in HT-7.The results indicate that the central iontemperature Ti0 follows the one-third power law in the product of central line-averaged densityne and plasma current Ip in Ohmic discharges and is therefore consistent with the Artsimovichscaling law Ti0 = K· （Ip· Bt·ne · R2）1/3.It is shown that there is an appreciable increase ofion temperature during the operation with both LHW and ICRF and that the increment of iontemperature in those shots is mainly due to the energy transfer via collisions between ions andelectrons rather that by direct heating of the ions.
