The Bluest Eye is Toni Morrison’s first novel.After its publication,it receives many criticisms.This article aims to ana lyze Pecola and Claudia’s understandings about black culture,then to clarify that different in...The Bluest Eye is Toni Morrison’s first novel.After its publication,it receives many criticisms.This article aims to ana lyze Pecola and Claudia’s understandings about black culture,then to clarify that different interpretations of the very name"the bluest eye"lead to different fates.With different visions of the black heritage,Pecola and Claudia have different perception of the world and thus have widely divergent outcomes in the painful circumstances.展开更多
The present paper reports eight heteropoty blues of double 2:17 motybdophosphates tanthanide comptexes with tacunary Dawson structure, i.e., K_(17)H_2[Ln(P_2Mo_2~ⅤMo_(15)~ⅥO_(16))_2], nH_2O and K_(17)H_4 [Ln(P_2Mo~...The present paper reports eight heteropoty blues of double 2:17 motybdophosphates tanthanide comptexes with tacunary Dawson structure, i.e., K_(17)H_2[Ln(P_2Mo_2~ⅤMo_(15)~ⅥO_(16))_2], nH_2O and K_(17)H_4 [Ln(P_2Mo~Ⅴ_4Mo_(13)~ⅥO_(61))_2], nH_2O(Ln=La, Pr, Sm, Yb). They were characterized by etementat anatyses, potentiometric titration, IR, UV, potarography, cyclic vottammetry, X-ray photoelectron spectra, X-ray powder diffraction, thermat analyses and ESR. The results show that the properties of these heteropoty btues are different from those of heteropoty blues with saturated Dawson structure and other tacunary series. They are more stabte than their parent heteropoty acids in aqueous sotution and have the abitity of anti-base decomposition.展开更多
The 1991 Booker Prize--winning novelist Ben Okri, while traveling in the Deep South after Barack Obama＇s victory in the November 2008 presidential election, wrote that Elvis Presley was a lingering deity in the city ...The 1991 Booker Prize--winning novelist Ben Okri, while traveling in the Deep South after Barack Obama＇s victory in the November 2008 presidential election, wrote that Elvis Presley was a lingering deity in the city of Memphis. The images of Elvis Presley, who earned the sobriquet ＂King of Rock＂ early in his career, and that of B. B. King, the exemplar extraordinaire of the Blues, are ubiquitous in the city of Memphis, which may be regarded as a metonym for the Blues and Rock ＇n Roll. The byline for the city of Memphis is, ＂Home of the Blues, Birthplace of Rock ＇n Roll＂, and this fact announces itself to the visitor as soon as he/she enters the arrivals concourse of the Memphis International Airport. As one proceeds towards the baggage claims area, the images which saturate the walkway create an aura that is redolent of the city＇s vibrant Rock ＇n Roll era. Drawing on Foucault＇s notion of heterotopias, as well as Jakobson＇s work on metonymy, this paper explores the hybrid musical spatiality of the city of Memphis and its environs, as well as its iconic status in the evolution of Rock ＇n Roll which was engendered by the Blues.展开更多
Chinese from all walks of life face the bite of inflation as the country’s consumer price index(CPI) soars DATA of the National Bureau of Statistics (NBS) show the country’s consumer price index(CPI),a broad measure...Chinese from all walks of life face the bite of inflation as the country’s consumer price index(CPI) soars DATA of the National Bureau of Statistics (NBS) show the country’s consumer price index(CPI),a broad measure of inflation, grew 5.3 percent in April,after recording a 32-month-high growth of 5.4 percent in展开更多
LIKE Christmas in the West, Chinese New Year, or Spring Festival, remains the most important social and economic holiday in China. But a survey conducted by Horizon Key Research at the end of 2012. two months before C...LIKE Christmas in the West, Chinese New Year, or Spring Festival, remains the most important social and economic holiday in China. But a survey conducted by Horizon Key Research at the end of 2012. two months before Chinese New Year, which fell on Febru- ary 10 this year. indicated that over 70 percent of young people in China feel stressed about the celebration. Due to a clash between centuries-old traditions and modern life. China＇s young people have increas- ingly complex feelings about Spring Festival, and now observe and spend the holiday in a very different man- her than previous generations.展开更多
For eight kinds of acidic potassium salts of hetcropoly blues which have not been reported in literature,the isomeri/.ation reaction in solution for these two-and four-electron hcteropoly blue solids were investigated...For eight kinds of acidic potassium salts of hetcropoly blues which have not been reported in literature,the isomeri/.ation reaction in solution for these two-and four-electron hcteropoly blue solids were investigated by means of polarograms,cyclic voltammetry,31P NMR and X-ray diffraction methods.The heteropolynier of PMo12 and AsMo12 converte to their β-isomers during isomerization reaction which were found to have antiacidolysis property.展开更多
In this study,sawdust served as a carbon source and urea as a nitrogen source to synthesize carbonsupported,nitrogen-doped TiO_(2)composites via a one-pot solvothermal method.The composites were characterized using FT...In this study,sawdust served as a carbon source and urea as a nitrogen source to synthesize carbonsupported,nitrogen-doped TiO_(2)composites via a one-pot solvothermal method.The composites were characterized using FTIR,powder X-ray diffraction,X-ray photoelectron spectroscopy,ultraviolet-visible diffuse reflectance spectroscopy,thermogravimetry-derivative thermogravimetry,scanning electron microscopy-energy dispersive spectroscopy,and transmission electron microscopy.Results indicated that all synthesized composites exhibit the anatase phase,with those calcined at 800℃ demonstrating enhanced crystallinity.Nitrogen is incorporated into the TiO_(2)lattice,while carbon is predominantly located on the surface.Photodegradation experiments showed that 20 mg of composite N-TiO_(2)/C-800 achieved degradation rates of 93.4% for methylene blue(20 mg·L^(-1),50 mL)and 99.4% for oxytetracycline(20 mg·L^(-1),50 mL)within 30 min.Free radical capture experiments indicated that h+was the primary active species in the photocatalytic degradation process.展开更多
A machine learning-based APP may quickly and non-destructively evaluate the quality of parameters,such as hardness and anthocyanin content in blue honeysuckle berries(Lonicera caerulea L.,BHB),based on changes in peri...A machine learning-based APP may quickly and non-destructively evaluate the quality of parameters,such as hardness and anthocyanin content in blue honeysuckle berries(Lonicera caerulea L.,BHB),based on changes in pericarp color characteristics.The color feature information of the BHB pericarp was extracted,and the corresponding hardness and anthocyanin content were determined at various growing stages.Correlation analysis of BHB quality indexes was conducted by single and combined components of BHB epidermal color features.The results showed that fruit hardness had a significantly negative correlation with color feature parameter R-G,and its anthocyanin content had a significantly positive correlation with color feature parameter R.Comparing the eight models,random forest(RF)was established to evaluate the hardness and anthocyanin content of BHB according to the correlation between pericarp color features and hardness and anthocyanin content on BHB quality evaluation APP on the WeChat platform.The credibility of APP embedding RF model for evaluating hardness and anthocyanin content in BHB was validated with the determination coefficient of 0.89 and 0.93 in practice.This approach could efficiently and conveniently evaluate the quality indexes of BHB in real time and serve as a technical reference for the detection of quality indicators of other berries using smartphones.展开更多
In this study,Palm kernel shell(PKS)is utilized as a raw material to produce activated biochar as adsorbent for dye removal from wastewater,specifically methylene blue(MB)dye,by utilizing a simplified and costeffectiv...In this study,Palm kernel shell(PKS)is utilized as a raw material to produce activated biochar as adsorbent for dye removal from wastewater,specifically methylene blue(MB)dye,by utilizing a simplified and costeffective approach.Production of activated biocharwas carried out using both a furnace and a domesticmicrowave oven without an inert atmosphere.Three samples of palm kernel shell(PKS)based activated biochar labeled as samples A,B and C were carbonized inside the furnace at 800℃ for 1 h and then activated using the microwave-heating technique with varying heating times(0,5,10,and 15 min).The heating was conducted in the absence of an inert gas.Fourier Transform Infrared Spectroscopy(FTIR)highlighted a significant Si-O stretching vibration between 1040.5 to 692.7 cm−1,indicating the presence of key components(Silica and Alumina)in all PKS-based activated biochar samples.For wastewater treatment,activated biochar samples were tested against a 20 mg/LMethylene Blue(MB)solution,and the MB percentage removal was calculated for each run using a standard curve.Central Composite Design(CCD)experiments were conducted for optimization,with activated biochar Sample C exhibiting the highest adsorption capacity at 88.14%MB removal under specific conditions.ANOVA analysis confirmed the significance of the quadratic model,with a p-value of 0.0222 and R^(2)=0.9438.In conclusion,the results demonstrated the efficiency of PKS-based activated biochar as an adsorbent for MB removal in comparison to other commercial adsorbents.展开更多
Prussian blue analogs(PBAs)are considered one of the excellent cathode materials for sodium-ion batteries due to their low cost and high theoretical specific capacity,especially sodium-rich iron-based PBAs(FeHCF)can p...Prussian blue analogs(PBAs)are considered one of the excellent cathode materials for sodium-ion batteries due to their low cost and high theoretical specific capacity,especially sodium-rich iron-based PBAs(FeHCF)can provide higher energy density.FeHCF has a poor charge/discharge platform stability at high voltages(FeC_(6)moiety),which is mainly affected by its coordination environment.In this research,Cu^(+)(six-coordinated),which is close to the ionic radius of Fe^(2+),was used for substitution,the FeC_(6)vacancies of FeHCF were reduced,and the coordination environment was optimized.The low Cu^(+)-substituted FeHCF(Cu^(+)0.625)has an optimal electrochemical performance at 8.5 mA/g with a reversible specific capacity of 142 mA h/g and FeC_(6)moiety contribution of more than 68 mA h/g,which is superior to that of unmodified and other Cu^(2+)-substituted FeHCFs.In situ tests demonstrate the reversible structural stability of the Cu^(+)0.625,supporting the stability of their high-voltage platform capacity.This Cu^(+)substitution strategy further enriches the approach to optimize the coordination environment of sodium-rich FeHCF.展开更多
Manganese-based Prussian blue analogues(MnFePBAs),renowned for their high redox potential and dual redox-active sites,often fail to fully realize their intrinsic performance in zinc-ion batteries(ZIBs).In this work,th...Manganese-based Prussian blue analogues(MnFePBAs),renowned for their high redox potential and dual redox-active sites,often fail to fully realize their intrinsic performance in zinc-ion batteries(ZIBs).In this work,the underlying causes of the instability of monoclinic K^(+) -containing MnFePBA(KMnFePBA)cathodes in aqueous electrolytes were investigated.To prevent irreversible phase transitions,a lowconcentration,flame-retardant organic electrolyte operable under open-air conditions was developed.Utilizing triethyl phosphate(TEP)as the electrolyte solvent,the KMnFePBA cathode exhibited two distinct redox peaks at approximately 1.83 and 1.70 V,coupled with a high reversible capacity of -130 m A h g^(-1).The TEP electrolyte offers not only flame-retardant and anti-drying properties but also benefits from the inclusion of trace amounts of water,which enhances the redox kinetics.The optimized electrolyte enables Zn||KMnFePBA batteries to operate reversibly without structural degradation,function effectively across a wide temperature range,and suppress Zn dendrite formation by modulating the zinc-ion solvation structure and interfacial environment.This study presents a practical electrolyte engineering strategy for stabilizing monoclinic MnFePBA cathodes while simultaneously extending the lifespan of Zn anodes in ZIBs.展开更多
Hybrid local and charge-transfer(HLCT)states offer an effective pathway for developing efficient blue organic light-emitting diodes(OLEDs).In HLCT emitters,locally excited(LE)states enhance radiative transitions and p...Hybrid local and charge-transfer(HLCT)states offer an effective pathway for developing efficient blue organic light-emitting diodes(OLEDs).In HLCT emitters,locally excited(LE)states enhance radiative transitions and photoluminescence quantum yield,while charge-transfer(CT)states facilitate exciton harvesting via reverse intersystem crossing.Here,we propose an HLCT-oriented molecular design strategy to achieve efficient blue emission.Pyrene-imidazole(PyI)was employed as a weak donor and linked to benzoxazole(BO)acceptors through para-and meta-benzene π-bridges,affording two D-π-A molecules,p-PyI-PBO and m-PyI-PBO.The π-bridges strengthen conjugation and stabilize the HLCT state,while the para-to-meta linkage transforms a linear"I-shaped"geometry into a twisted"V-shaped"configuration,shortening conjugation and modulating donoracceptor coupling.This structural regulation produces a more balanced LE/CT distribution,suppressing excessive LE character while retaining sufficient CT contribution for efficient exciton utilization.As a result,m-PyI-PBO exhibits more favorable excited-state properties and delivers efficient blue emission with high color purity.Benefiting from its balanced HLCT characteristics and robust photophysical and thermal stability,the nondoped OLED based on m-PyI-PBO shows bright blue emission with CIE coordinates of(0.15,0.13),a maximum external quantum efficiency(EQE_(max))of 9.52%,and a low roll-off of 3.36%at 1000 cd^(-2).The doped device further emits deep blue with CIE coordinates of(0.16,0.06),close to the European Broadcasting Union standard,and achieves an EQE_(max)of 13.22%with an exciton utilization efficiency of 79.72%.This work demonstrates thatπ-bridge engineering combined with meta-linkage is an effective strategy for constructing efficient HLCT-type blue emitters.展开更多
Prussian blue analogs(PBAs)have emerged as environmentally friendly and structurally tunable cathode materials for aqueous ammonium-ion batteries(AIBs).However,the fundamental role of crystalline H_(2)O in regulating ...Prussian blue analogs(PBAs)have emerged as environmentally friendly and structurally tunable cathode materials for aqueous ammonium-ion batteries(AIBs).However,the fundamental role of crystalline H_(2)O in regulating ammonium-ion storage and transport remains poorly understood.In this study,we present a comprehensive comparison between hydrated NH_(4)NiHCF-H_(2)O and its anhydrous counterpart NH_(4)NiHCF,revealing the critical contribution of interstitial water to electrochemical performance.Structural and spectroscopic analyses confirm that interstitial water forms robust hydrogen bonds with NH_(4)+ions,stabilizing the PBA framework and mitigating structural degradation during cycling.Electrochemical measurements show that NH_(4)NiHCF-H_(2)O delivers a significantly higher specific capacity of 61 mA h g^(−1)at 0.2 C and markedly improved rate performance compared to NH_(4)NiHCF(48 mA h g^(−1)at 0.2 C).Kinetic analysis reveals that interstitial water enhances NH_(4)+diffusion,as evidenced by higher diffusion coefficients.Furthermore,density functional theory(DFT)calculations demonstrate that crystal water acts as a hydrogen bond acceptor,preferentially interacting with NH_(4)+and reducing the migration energy barrier,thereby facilitating fast ion transport.This work provides fundamental insights into the role of crystal water in PBAs and offers a rational design strategy for improving the kinetics,structural stability of PBAs cathodes for AIBs.展开更多
In the hilly regions of Oudomxay Province,Laos,rows of deep blue photovoltaic panels are converting the scorching sunlight into clean electricity.They are part of the first phase of the Northern Laos Interconnected Cl...In the hilly regions of Oudomxay Province,Laos,rows of deep blue photovoltaic panels are converting the scorching sunlight into clean electricity.They are part of the first phase of the Northern Laos Interconnected Clean Energy Base,which was developed by China General Nuclear Power Group and became operational at the end of 2025.展开更多
Although manganese Prussian blue analogues(Mn-PBAs)offer advantages as cost-effective,high-energy-density cathode materials for sodium-ion batteries,their practical application is severely constrained by substantial c...Although manganese Prussian blue analogues(Mn-PBAs)offer advantages as cost-effective,high-energy-density cathode materials for sodium-ion batteries,their practical application is severely constrained by substantial capacity degradation during long-term cycling.This performance deterioration is closely associated with the structural instability of the material during the cycling process,which is mainly attributed to the gradual dissolution of the active material into the electrolyte and severe lattice distortion during Na+intercalation/deintercalation.Fortunately,the aforementioned challenges can be effectively addressed by fabricating an in situ engineered nickel cage(ISE-NC)on Mn-PBAs(denoted as Mn-PBAs-NC).Experimental characterization combined with theoretical calculations reveals that this spontaneously formed nickel cage not only suppresses the diffusion of Mn-PBAs into the electrolyte but also acts as a structural stabilizer,significantly alleviating lattice distortion during cycling.This dual stabilization mechanism ensures remarkable cycling stability,with Mn-PBAs-NC delivering a retained capacity of 96.4 mA h g^(−1)(80%capacity retention)over 2,300 cycles at 2 C,elevating the cycle life of Mn-PBAs to unprecedented levels.展开更多
Report highlights job fears sweeping China unemployment fears are rising across China amid the worsening global financial crisis, according to a recent report. The Society Blue Paper,
China’s KTV industry could shrink as a result of rising costs Arise in karaoke club copyright charges could cause major ripples in China’s booming KTV industry.In early August 2008, China Audio-Video Copyright Assoc...China’s KTV industry could shrink as a result of rising costs Arise in karaoke club copyright charges could cause major ripples in China’s booming KTV industry.In early August 2008, China Audio-Video Copyright Association(CAVCA) publicized new karaoke charges across China, with Shanghai topping the charge rates at 11.1 yuan ($1.6) per day for each karaoke room.展开更多
文摘The Bluest Eye is Toni Morrison’s first novel.After its publication,it receives many criticisms.This article aims to ana lyze Pecola and Claudia’s understandings about black culture,then to clarify that different interpretations of the very name"the bluest eye"lead to different fates.With different visions of the black heritage,Pecola and Claudia have different perception of the world and thus have widely divergent outcomes in the painful circumstances.
文摘The present paper reports eight heteropoty blues of double 2:17 motybdophosphates tanthanide comptexes with tacunary Dawson structure, i.e., K_(17)H_2[Ln(P_2Mo_2~ⅤMo_(15)~ⅥO_(16))_2], nH_2O and K_(17)H_4 [Ln(P_2Mo~Ⅴ_4Mo_(13)~ⅥO_(61))_2], nH_2O(Ln=La, Pr, Sm, Yb). They were characterized by etementat anatyses, potentiometric titration, IR, UV, potarography, cyclic vottammetry, X-ray photoelectron spectra, X-ray powder diffraction, thermat analyses and ESR. The results show that the properties of these heteropoty btues are different from those of heteropoty blues with saturated Dawson structure and other tacunary series. They are more stabte than their parent heteropoty acids in aqueous sotution and have the abitity of anti-base decomposition.
文摘The 1991 Booker Prize--winning novelist Ben Okri, while traveling in the Deep South after Barack Obama＇s victory in the November 2008 presidential election, wrote that Elvis Presley was a lingering deity in the city of Memphis. The images of Elvis Presley, who earned the sobriquet ＂King of Rock＂ early in his career, and that of B. B. King, the exemplar extraordinaire of the Blues, are ubiquitous in the city of Memphis, which may be regarded as a metonym for the Blues and Rock ＇n Roll. The byline for the city of Memphis is, ＂Home of the Blues, Birthplace of Rock ＇n Roll＂, and this fact announces itself to the visitor as soon as he/she enters the arrivals concourse of the Memphis International Airport. As one proceeds towards the baggage claims area, the images which saturate the walkway create an aura that is redolent of the city＇s vibrant Rock ＇n Roll era. Drawing on Foucault＇s notion of heterotopias, as well as Jakobson＇s work on metonymy, this paper explores the hybrid musical spatiality of the city of Memphis and its environs, as well as its iconic status in the evolution of Rock ＇n Roll which was engendered by the Blues.
文摘Chinese from all walks of life face the bite of inflation as the country’s consumer price index(CPI) soars DATA of the National Bureau of Statistics (NBS) show the country’s consumer price index(CPI),a broad measure of inflation, grew 5.3 percent in April,after recording a 32-month-high growth of 5.4 percent in
文摘LIKE Christmas in the West, Chinese New Year, or Spring Festival, remains the most important social and economic holiday in China. But a survey conducted by Horizon Key Research at the end of 2012. two months before Chinese New Year, which fell on Febru- ary 10 this year. indicated that over 70 percent of young people in China feel stressed about the celebration. Due to a clash between centuries-old traditions and modern life. China＇s young people have increas- ingly complex feelings about Spring Festival, and now observe and spend the holiday in a very different man- her than previous generations.
文摘For eight kinds of acidic potassium salts of hetcropoly blues which have not been reported in literature,the isomeri/.ation reaction in solution for these two-and four-electron hcteropoly blue solids were investigated by means of polarograms,cyclic voltammetry,31P NMR and X-ray diffraction methods.The heteropolynier of PMo12 and AsMo12 converte to their β-isomers during isomerization reaction which were found to have antiacidolysis property.
文摘In this study,sawdust served as a carbon source and urea as a nitrogen source to synthesize carbonsupported,nitrogen-doped TiO_(2)composites via a one-pot solvothermal method.The composites were characterized using FTIR,powder X-ray diffraction,X-ray photoelectron spectroscopy,ultraviolet-visible diffuse reflectance spectroscopy,thermogravimetry-derivative thermogravimetry,scanning electron microscopy-energy dispersive spectroscopy,and transmission electron microscopy.Results indicated that all synthesized composites exhibit the anatase phase,with those calcined at 800℃ demonstrating enhanced crystallinity.Nitrogen is incorporated into the TiO_(2)lattice,while carbon is predominantly located on the surface.Photodegradation experiments showed that 20 mg of composite N-TiO_(2)/C-800 achieved degradation rates of 93.4% for methylene blue(20 mg·L^(-1),50 mL)and 99.4% for oxytetracycline(20 mg·L^(-1),50 mL)within 30 min.Free radical capture experiments indicated that h+was the primary active species in the photocatalytic degradation process.
基金Supported by the National Natural Science Foundation of China(32072352)the National Key Research and Development Program Project of China(2022YFD1600500)。
文摘A machine learning-based APP may quickly and non-destructively evaluate the quality of parameters,such as hardness and anthocyanin content in blue honeysuckle berries(Lonicera caerulea L.,BHB),based on changes in pericarp color characteristics.The color feature information of the BHB pericarp was extracted,and the corresponding hardness and anthocyanin content were determined at various growing stages.Correlation analysis of BHB quality indexes was conducted by single and combined components of BHB epidermal color features.The results showed that fruit hardness had a significantly negative correlation with color feature parameter R-G,and its anthocyanin content had a significantly positive correlation with color feature parameter R.Comparing the eight models,random forest(RF)was established to evaluate the hardness and anthocyanin content of BHB according to the correlation between pericarp color features and hardness and anthocyanin content on BHB quality evaluation APP on the WeChat platform.The credibility of APP embedding RF model for evaluating hardness and anthocyanin content in BHB was validated with the determination coefficient of 0.89 and 0.93 in practice.This approach could efficiently and conveniently evaluate the quality indexes of BHB in real time and serve as a technical reference for the detection of quality indicators of other berries using smartphones.
文摘In this study,Palm kernel shell(PKS)is utilized as a raw material to produce activated biochar as adsorbent for dye removal from wastewater,specifically methylene blue(MB)dye,by utilizing a simplified and costeffective approach.Production of activated biocharwas carried out using both a furnace and a domesticmicrowave oven without an inert atmosphere.Three samples of palm kernel shell(PKS)based activated biochar labeled as samples A,B and C were carbonized inside the furnace at 800℃ for 1 h and then activated using the microwave-heating technique with varying heating times(0,5,10,and 15 min).The heating was conducted in the absence of an inert gas.Fourier Transform Infrared Spectroscopy(FTIR)highlighted a significant Si-O stretching vibration between 1040.5 to 692.7 cm−1,indicating the presence of key components(Silica and Alumina)in all PKS-based activated biochar samples.For wastewater treatment,activated biochar samples were tested against a 20 mg/LMethylene Blue(MB)solution,and the MB percentage removal was calculated for each run using a standard curve.Central Composite Design(CCD)experiments were conducted for optimization,with activated biochar Sample C exhibiting the highest adsorption capacity at 88.14%MB removal under specific conditions.ANOVA analysis confirmed the significance of the quadratic model,with a p-value of 0.0222 and R^(2)=0.9438.In conclusion,the results demonstrated the efficiency of PKS-based activated biochar as an adsorbent for MB removal in comparison to other commercial adsorbents.
基金supported by the Key Talent Project of Gansu Province(2025RCXM017)the National Natural Science Foundation of China(52261040)+2 种基金the Postgraduate Innovation Star Program of Gansu Province(2025CXZX-476)the Major Science and Technology Project of Gansu Province(22ZD6GA008)the Innovation Driven Assistance Engineering Project of Gansu Association for Science and Technology(GXH20250325-5).
文摘Prussian blue analogs(PBAs)are considered one of the excellent cathode materials for sodium-ion batteries due to their low cost and high theoretical specific capacity,especially sodium-rich iron-based PBAs(FeHCF)can provide higher energy density.FeHCF has a poor charge/discharge platform stability at high voltages(FeC_(6)moiety),which is mainly affected by its coordination environment.In this research,Cu^(+)(six-coordinated),which is close to the ionic radius of Fe^(2+),was used for substitution,the FeC_(6)vacancies of FeHCF were reduced,and the coordination environment was optimized.The low Cu^(+)-substituted FeHCF(Cu^(+)0.625)has an optimal electrochemical performance at 8.5 mA/g with a reversible specific capacity of 142 mA h/g and FeC_(6)moiety contribution of more than 68 mA h/g,which is superior to that of unmodified and other Cu^(2+)-substituted FeHCFs.In situ tests demonstrate the reversible structural stability of the Cu^(+)0.625,supporting the stability of their high-voltage platform capacity.This Cu^(+)substitution strategy further enriches the approach to optimize the coordination environment of sodium-rich FeHCF.
基金supported by the National Natural Science Foundation of China(22409002,62371003)the Open Research Fund of Songshan Lake Materials Laboratory(2023SLABFN18)+1 种基金Anhui Provincial Natural Science Foundation(2308085QB46)Scientific Research Foundation of Education Department of Anhui Province of China(2023AH051109,2022AH010025)。
文摘Manganese-based Prussian blue analogues(MnFePBAs),renowned for their high redox potential and dual redox-active sites,often fail to fully realize their intrinsic performance in zinc-ion batteries(ZIBs).In this work,the underlying causes of the instability of monoclinic K^(+) -containing MnFePBA(KMnFePBA)cathodes in aqueous electrolytes were investigated.To prevent irreversible phase transitions,a lowconcentration,flame-retardant organic electrolyte operable under open-air conditions was developed.Utilizing triethyl phosphate(TEP)as the electrolyte solvent,the KMnFePBA cathode exhibited two distinct redox peaks at approximately 1.83 and 1.70 V,coupled with a high reversible capacity of -130 m A h g^(-1).The TEP electrolyte offers not only flame-retardant and anti-drying properties but also benefits from the inclusion of trace amounts of water,which enhances the redox kinetics.The optimized electrolyte enables Zn||KMnFePBA batteries to operate reversibly without structural degradation,function effectively across a wide temperature range,and suppress Zn dendrite formation by modulating the zinc-ion solvation structure and interfacial environment.This study presents a practical electrolyte engineering strategy for stabilizing monoclinic MnFePBA cathodes while simultaneously extending the lifespan of Zn anodes in ZIBs.
基金supported by the Natural Science Foundation of Hei-longjiang Province(No.YQ2023B001)the"Academic Backbone"Project of Northeast Agricultural University(No.20xG19).
文摘Hybrid local and charge-transfer(HLCT)states offer an effective pathway for developing efficient blue organic light-emitting diodes(OLEDs).In HLCT emitters,locally excited(LE)states enhance radiative transitions and photoluminescence quantum yield,while charge-transfer(CT)states facilitate exciton harvesting via reverse intersystem crossing.Here,we propose an HLCT-oriented molecular design strategy to achieve efficient blue emission.Pyrene-imidazole(PyI)was employed as a weak donor and linked to benzoxazole(BO)acceptors through para-and meta-benzene π-bridges,affording two D-π-A molecules,p-PyI-PBO and m-PyI-PBO.The π-bridges strengthen conjugation and stabilize the HLCT state,while the para-to-meta linkage transforms a linear"I-shaped"geometry into a twisted"V-shaped"configuration,shortening conjugation and modulating donoracceptor coupling.This structural regulation produces a more balanced LE/CT distribution,suppressing excessive LE character while retaining sufficient CT contribution for efficient exciton utilization.As a result,m-PyI-PBO exhibits more favorable excited-state properties and delivers efficient blue emission with high color purity.Benefiting from its balanced HLCT characteristics and robust photophysical and thermal stability,the nondoped OLED based on m-PyI-PBO shows bright blue emission with CIE coordinates of(0.15,0.13),a maximum external quantum efficiency(EQE_(max))of 9.52%,and a low roll-off of 3.36%at 1000 cd^(-2).The doped device further emits deep blue with CIE coordinates of(0.16,0.06),close to the European Broadcasting Union standard,and achieves an EQE_(max)of 13.22%with an exciton utilization efficiency of 79.72%.This work demonstrates thatπ-bridge engineering combined with meta-linkage is an effective strategy for constructing efficient HLCT-type blue emitters.
基金supported by the National Natural Science Foundation of China (52172227)the Natural Science Foundation of Hubei Province (2023AFA114)+2 种基金the Guizhou Provincial Key Technology R&D Program (ZD[2025]019)provided by the Startup Fund (20QD80 and 22QD28)support from the Science&Technology Top Talents Program of Guizhou Province ([2024]349)
文摘Prussian blue analogs(PBAs)have emerged as environmentally friendly and structurally tunable cathode materials for aqueous ammonium-ion batteries(AIBs).However,the fundamental role of crystalline H_(2)O in regulating ammonium-ion storage and transport remains poorly understood.In this study,we present a comprehensive comparison between hydrated NH_(4)NiHCF-H_(2)O and its anhydrous counterpart NH_(4)NiHCF,revealing the critical contribution of interstitial water to electrochemical performance.Structural and spectroscopic analyses confirm that interstitial water forms robust hydrogen bonds with NH_(4)+ions,stabilizing the PBA framework and mitigating structural degradation during cycling.Electrochemical measurements show that NH_(4)NiHCF-H_(2)O delivers a significantly higher specific capacity of 61 mA h g^(−1)at 0.2 C and markedly improved rate performance compared to NH_(4)NiHCF(48 mA h g^(−1)at 0.2 C).Kinetic analysis reveals that interstitial water enhances NH_(4)+diffusion,as evidenced by higher diffusion coefficients.Furthermore,density functional theory(DFT)calculations demonstrate that crystal water acts as a hydrogen bond acceptor,preferentially interacting with NH_(4)+and reducing the migration energy barrier,thereby facilitating fast ion transport.This work provides fundamental insights into the role of crystal water in PBAs and offers a rational design strategy for improving the kinetics,structural stability of PBAs cathodes for AIBs.
基金findings from the Research on the Innovative Mechanism for Coordinated Development of Ecological Security between China’s Yunnan Province and the Vietnam-LaosMyanmar Region,a general project of Yunnan Provincial Philosophy and Social Sciences Planning。
文摘In the hilly regions of Oudomxay Province,Laos,rows of deep blue photovoltaic panels are converting the scorching sunlight into clean electricity.They are part of the first phase of the Northern Laos Interconnected Clean Energy Base,which was developed by China General Nuclear Power Group and became operational at the end of 2025.
基金financially supported by the Ten-thousand Talents Programthe K. C. Wong Pioneer Talent Program+3 种基金China Three Gorges Corporation (WWKY-2021–0027)Inner Mongolia Science and Technology Plan (2021ZD0033)the National Natural Science Foundation of China (52202121)funded by China Petroleum&Chemical Corporation (123091)
文摘Although manganese Prussian blue analogues(Mn-PBAs)offer advantages as cost-effective,high-energy-density cathode materials for sodium-ion batteries,their practical application is severely constrained by substantial capacity degradation during long-term cycling.This performance deterioration is closely associated with the structural instability of the material during the cycling process,which is mainly attributed to the gradual dissolution of the active material into the electrolyte and severe lattice distortion during Na+intercalation/deintercalation.Fortunately,the aforementioned challenges can be effectively addressed by fabricating an in situ engineered nickel cage(ISE-NC)on Mn-PBAs(denoted as Mn-PBAs-NC).Experimental characterization combined with theoretical calculations reveals that this spontaneously formed nickel cage not only suppresses the diffusion of Mn-PBAs into the electrolyte but also acts as a structural stabilizer,significantly alleviating lattice distortion during cycling.This dual stabilization mechanism ensures remarkable cycling stability,with Mn-PBAs-NC delivering a retained capacity of 96.4 mA h g^(−1)(80%capacity retention)over 2,300 cycles at 2 C,elevating the cycle life of Mn-PBAs to unprecedented levels.
文摘Report highlights job fears sweeping China unemployment fears are rising across China amid the worsening global financial crisis, according to a recent report. The Society Blue Paper,
文摘China’s KTV industry could shrink as a result of rising costs Arise in karaoke club copyright charges could cause major ripples in China’s booming KTV industry.In early August 2008, China Audio-Video Copyright Association(CAVCA) publicized new karaoke charges across China, with Shanghai topping the charge rates at 11.1 yuan ($1.6) per day for each karaoke room.
