Silver-ceramics (Ag2MO2)(M=Co, Ni, or Cu) were prepared through thermal decompositionof coprecipitated oxalates. Pellets of these materials were annealed at 350℃ for different timeperiods up to 5 h. The effect of ann...Silver-ceramics (Ag2MO2)(M=Co, Ni, or Cu) were prepared through thermal decompositionof coprecipitated oxalates. Pellets of these materials were annealed at 350℃ for different timeperiods up to 5 h. The effect of annealing time on the transport properties was studied. IR andX-ray spectra were also studied.展开更多
Birefringent materials with large optical anisotropy,which can be used to modulate the polarization of light,play a key role in laser techniques and science.However,the exploration studies of new,superior birefringent...Birefringent materials with large optical anisotropy,which can be used to modulate the polarization of light,play a key role in laser techniques and science.However,the exploration studies of new,superior birefringent materials develop extremely slowly due to the lack of effective guidelines for rational design.Herein,three antimony(Ⅲ)fluoride oxalates,namely,Na_(2)Sb_(2)(C_(2)O_(4))F_(6),K_(2)Sb_(2)(C_(2)O_(4))F_(6),and Cs_(2)Sb_(2)-(C_(2)O_(4))_(2)F_(4)·H_(2)O,were successfully synthesized through a rational combination ofπ-conjugated C_(2)O_(4)^(2-)anions and Sb^(3+)cations with stereochemically active lone pairs.These oxalates feature unique quasi-one-dimensional chain structures that induce large optical anisotropy.Remarkably,Cs_(2)Sb_(2)(C_(2)O_(4))_(2)-F_(4)·H_(2)O exhibits the largest birefringence(0.325@546 nm)among all reported antimony(Ⅲ)-based oxysalts.Detailed structural analysis and theoretical calculations confirmed that the optical anisotropy of these oxalates could be tuned through the synergetic interactions of templated cations and anionic functional groups.This work may open the door to efficiently designing excellent birefringent materials and guide the further discovery of other novel structure-driven functional materials.展开更多
All-perovskite tandem solar cells(ATSCs) have the potential to surpass the Shockley-Queisser efficiency limit of conventional single-junction devices. However, the performance and stability of mixed tin–lead(Sn–Pb) ...All-perovskite tandem solar cells(ATSCs) have the potential to surpass the Shockley-Queisser efficiency limit of conventional single-junction devices. However, the performance and stability of mixed tin–lead(Sn–Pb) perovskite solar cells(PSCs), which are crucial components of ATSCs, are much lower than those of lead-based perovskites. The primary challenges include the high crystallization rate of perovskite materials and the susceptibility of Sn^(2+) oxidation, which leads to rough morphology and unfavorable p-type self-doping. To address these issues, we introduced ethylhydrazine oxalate(EDO) at the perovskite interface, which effectively inhibits the oxidation of Sn^(2+) and simultaneously enhances the crystallinity of the perovskite. Consequently, the EDO-modified mixed tin-lead PSCs reached a power conversion efficiency(PCE) of 21.96% with high reproducibility. We further achieved a 27.58% efficient ATSCs by using EDO as interfacial passivator in the Sn-Pb PSCs.展开更多
The structure-performance relationship of Cu/Al_(2)O_(3) catalysts in the hydrogenation of diethyl oxalate(DEO)for the synthesis of alcohol ether esters has been investigated by various characterization techniques inc...The structure-performance relationship of Cu/Al_(2)O_(3) catalysts in the hydrogenation of diethyl oxalate(DEO)for the synthesis of alcohol ether esters has been investigated by various characterization techniques including XRD,XPS,N2O titration,and 27Al MAS-NMR.The results showed that when the crystal configurations of Al_(2)O_(3) were the same,increasing the specific surface area could effectively refine the size of copper nanoparticles(Cu NPs),and ultimately improve the conversion of DEO.Meanwhile,the smaller size ofγ-Al_(2)O_(3)(HSAl and SBAl)loaded Cu NPs promotes the reaction towards the deep hydrogenation to produce ethanol(EtOH)and ethylene glycol(EG).Besides,the larger size of Cu NPs on the surface of amorphous Al_(2)O_(3)(HTAl and SolAl)resulted in a lower conversion rate,where ethyl glycolate(Egly)is the main product.Despite there are differences in Al^(3+)ionic coordination in Al_(2)O_(3) with different crystal structures,the experimental data showed that the differences in Al^(3+)ionic coordination did not significantly affect the catalytic performance in the hydrogenation reaction.The formation of alcohol-ether ester chemicals is critically dependent on the interactions between Cu sites and acidic sites.Among them,EG and EtOH were dehydrated to form 2-ethoxyethanol via the SN2 mechanism,while Egly and EtOH were reacted to form ethyl ethoxyacetate(EEA)via the SN2 mechanism.This study provides a theoretical basis for the optimization of the coal-based glycol processes to achieve a diversified product portfolio.展开更多
Objective:Several therapeutic modalities for the prevention of calcium oxalate(CaOx)stones have been studied,but only a select few of these modalities have been incorporated into the American Urological Association gu...Objective:Several therapeutic modalities for the prevention of calcium oxalate(CaOx)stones have been studied,but only a select few of these modalities have been incorporated into the American Urological Association guidelines.Our study aimed to organize and interrogate existing research that may be promising for CaOx prevention.Methods:A literature search was conducted using MEDLINE and Embase from inception to November 16,2022.Our study population included adults with or without a history of CaOx kidney stones.Studies in which patients were treated with pharmacotherapies,herbal supplements,or uncategorized research chemicals that are not included in the current American Urological Association guidelines for preventing CaOx stones were included.Nonoriginal research was excluded.Results:Out of the 6155 identified articles,38 were included in the final analysis.The five distinct categories of interventions for stone prevention were“medications”,“herbal supplements”,“food and macronutrients”,“micronutrients”,and“enzymes and probiotics”.Modalities that were found to reduce known urinary risk factors were tolvaptan,cranberry juice,magnesium citrate,oxalate-degrading enzyme ALLN-177,and malic acid.Prophylaxis that reduced stone formation were sodium-glucose cotransporter-2 inhibitors,eicosapentaenoic acid,ethane-1-hydroxy-1,1-disphosphonate.Therapies that reduced urinary risk factors and stone formation were Phyllanthus niruri,rice bran,and magnesium hydroxide.Conclusion:Several of the identified therapies may provide prophylactic benefits for CaOx stone formation and may be useful for inclusion in guidelines for kidney stone prevention.展开更多
Molybdenum carbide has shown great potential in various hydrogenation reactions,and serves as a primary active species for synthesis of ethanol from dimethyl oxalate hydrogenation process which is a crucial step in th...Molybdenum carbide has shown great potential in various hydrogenation reactions,and serves as a primary active species for synthesis of ethanol from dimethyl oxalate hydrogenation process which is a crucial step in the efficient utilization of coal resources.In this study,a molybdenum carbide catalyst with a three-dimensional mesh-like hollow structure and lattice defects was carefully designed.The MoO_(3)precursor with abundant oxygen vacancies and defects was prepared by flame spray pyrolysis,and a structural modifier,Cu,was introduced by sputtering.The Cu deposited by sputtering affected the carburization and phase evolution processes.A three-dimensional mesh-like hollow structure composed of defective molybdenum carbide is formed,with theβ-Mo_(2)C exhibiting lattice distortions and defects.This defectiveβ-Mo_(2)C exhibits high reactivity,and facilitates the C=O hydrogenation process,showing a high reactivity of 83.1%yield in the hydrogenation of dimethyl oxalate.This work provides a new approach to the design and application of molybdenum carbide catalysts.展开更多
Oxalate content in spinach is a key trait of interest due to its relevance to human health.Understanding the genetic basis of it can facilitate the development of spinach varieties with reduced oxalate levels.In pursu...Oxalate content in spinach is a key trait of interest due to its relevance to human health.Understanding the genetic basis of it can facilitate the development of spinach varieties with reduced oxalate levels.In pursuit of understanding the genetic determinants,a diverse panel comprising 288 spinach accessions underwent thorough phenotyping of oxalate content and were subjected to whole-genome resequencing,resulting in a comprehensive dataset encompassing 14386 single-nucleotide polymorphisms(SNPs).Leveraging this dataset,we conducted a genome-wide association study(GWAS)to identify noteworthy SNPs associated with oxalate content.Furthermore,we employed genomic prediction(GP)via cross-prediction,utilizing five GP models,to assess genomic estimated breeding values(GEBVs)for oxalate content.The observed normal distribution and the wide range of oxalate content,exceeding 600.0 mg$100 g^(-1),underscore the complex and quantitative nature of this trait,likely influenced by multiple genes.Additionally,our analysis revealed distinct stratification,delineating the population into four discernible subpopulations.Furthermore,GWAS analysis employing five models in GAPIT 3 and TASSEL 5 unveiled nine significant SNPs(four SNPs on chromosome 1 and five on chromosome 5)associated with oxalate content.These loci exhibited associations with six candidate genes,which might have potential contribution to oxalate content regulation.Remarkably,our GP models exhibited notable predictive abilities,yielding average accuracies of up to 0.51 for GEBV estimation.The integration of GWAS and GP approaches offers a holistic comprehension of the genetic underpinnings of oxalate content in spinach.These findings offered a promising avenue for the development of spinach cultivars and hybrids optimized for oxalate levels,promoting consumer health.展开更多
In this paper,the research progress of Cu-based catalyst and the activity enhancement strategies in the hydrogenation of dimethyl oxalate(DMO)to ethylene glycol(EG)was reviewed.As a green and economical ethylene glyco...In this paper,the research progress of Cu-based catalyst and the activity enhancement strategies in the hydrogenation of dimethyl oxalate(DMO)to ethylene glycol(EG)was reviewed.As a green and economical ethylene glycol production path,the core of DMO hydrogenation of EG lies in the rational design and optimization of catalysts.This paper first introduces the background of the DMO hydrogenation system EG significance and the important effect of Cu-based catalyst in the reaction,particularly emphasizing the coordination with the Cu^(+)-Cu^(0) species catalytic effect.Then,many factors affecting the activity of Cu-based catalysts were analyzed in detail,including the equilibrium effect between Cu^(0) and Cu+species,the surface dispersion of Cu species,the interaction between metal and support,and the morphology effect of the catalyst.Regarding strategies for improving catalyst performance,this paper summarized effective measures such as optimizing support structure,adding promoters and optimizing preparation methods,and demonstrated the practical application effects of these strategies through representative catalyst examples.In addition,this paper also discusses the complex relationship between the influencing factors and catalyst performance.It points out the key directions for future research,with in-depth exploration of the correlation between catalyst structure and performance,the development of new catalysts,and the application of machine learning and big data technology in the catalyst research and development.In summary,this paper provides comprehensive theoretical guidance and practical reference for the performance optimization of Cu-based catalysts for DMO hydrogenation to EG.展开更多
Abstract:In today’s economy,determining accessible and affordable techniques to remove Heavy Metals(HMs)from wastewater is crucial.Activated carbon is highly effective in adsorbing HMs due to its large surface area a...Abstract:In today’s economy,determining accessible and affordable techniques to remove Heavy Metals(HMs)from wastewater is crucial.Activated carbon is highly effective in adsorbing HMs due to its large surface area and porous structure.It works by attracting and binding HM ions to its surface.Okoubaka is known for its medicinal properties and some studies suggest it has detoxifying effects.However,its specific role in HM removal would likely involve binding mechanisms like other plant-based materials.This study examines the efficiency of activated charcoal,charred versus uncharred Okoubaka plant materials,eggshells and oxalic acid to remove HMs like copper,lead,and zinc from contaminated water.展开更多
Herein,we present the electrocatalytic four-electron hydrogenation of oxalic acid into glycolic acid using black TiO_(2)as an electrocatalyst.Oxalic acid is an abundant compound found in several sources of organic was...Herein,we present the electrocatalytic four-electron hydrogenation of oxalic acid into glycolic acid using black TiO_(2)as an electrocatalyst.Oxalic acid is an abundant compound found in several sources of organic waste.The results showed a high selectivity of black TiO_(2)toward glycolic acid,with the formation of glyoxylic acid being the rate-limiting step (glyoxylic acid is the two-electron intermediate).The highest Faradaic efficiency (FE) of 69.6%±8.3% was achieved at 10.2 mA cm^(-2)in 4 h of electrolysis using an H-type cell operated at room temperature,with 50.2%±3.8% of oxalic acid conversion (degradation kinetic constant k=0.0042±0.0001 min-1),58.8%±7.0%of reaction yield and 1.2±0.18 g L-1of glycolic acid production.A theoretical model of black TiO_(2)coming from anatase TiO_(2)was implemented by introducing Ti3+defects,which gave black TiO_(2)the theoretical capability to easily transform oxalic acid into glycolic acid as experimentally observed.The reaction mechanism was supported and described in detail by density functional theory calculations,which revealed that surface Ti^(3+)states were the main catalytic sites.This is the first time that a detailed step-by-step mechanism at the atomic level has been proposed for this electrocatalytic reaction,which represents a valuable contribution to the understanding of this process of high energy/environmental interest.This is also the first time that black TiO_(2)has been used as an electrocatalyst for this sustainable process.展开更多
Ethanol synthesis via dimethyl oxalate hydrogenation has garnered increasing attention in the fields of syngas utilization.Althoughε-Fe_(2)C has been identified as a promising active species for DMO hydrogenation to ...Ethanol synthesis via dimethyl oxalate hydrogenation has garnered increasing attention in the fields of syngas utilization.Althoughε-Fe_(2)C has been identified as a promising active species for DMO hydrogenation to ethanol,its formation is kinetically challenging during carbonization.In this work,a Fe_(4)N phase was first synthesized by pretreating a 30Fe/SiO_(2)catalyst in an ammonia environment,followed by carbonization in a methanol-H_(2) flow to obtain ε-Fe_(2)C as the active phase.Fe_(4)N,rather than Fe-O-Si,facilitates the transformation into iron carbide during the carbonization process.The transformation pathway of iron nitride(Fe_(x)N)is mediated by intermediate iron carbonyl species(Fe-CO),ultimately leading to the formation of iron carbide as the active phase.The resulting catalyst exhibited 40 times higher catalytic activity than the untreated catalyst in DMO hydrogenation.Combined structure properties and DFT calculation revealed that the lower energy barrier ofε-Fe_(2)C for ester hydrogenation underpins/strengthens its superior performance,while the STY of ε-Fe_(2)C is 2.8 times that ofε'-Fe_(2.2)C and 58 times that ofχ-Fe_(5)C_(2).This study provides a novel strategy for designing highly efficient iron carbide catalysts for the esters hydrogenation system.展开更多
Nano zero-valent iron(nZVI)is a promising phosphate adsorbent for advanced phosphate removal.However,the rapid passivation of nZVI and the low activity of adsorption sites seriously limit its phosphate removal perform...Nano zero-valent iron(nZVI)is a promising phosphate adsorbent for advanced phosphate removal.However,the rapid passivation of nZVI and the low activity of adsorption sites seriously limit its phosphate removal performance,accounting for its inapplicability to meet the emission criteria of 0.1 mg P/L phosphate.In this study,we report that the oxalate modification can inhibit the passivation of nZVI and alter the multi-stage phosphate adsorption mechanism by changing the adsorption sites.As expected,the stronger antipassivation ability of oxalate modified nZVI(OX-nZVI)strongly favored its phosphate adsorption.Interestingly,the oxalate modification endowed the surface Fe(III)sites with the lowest chemisorption energy and the fastest phosphate adsorption ability than the other adsorption sites,by in situ forming a Fe(III)-phosphate-oxalate ternary complex,therefore enabling an advanced phosphate removal process.At an initial phosphate concentration of 1.00 mg P/L,pH of 6.0 and a dosage of 0.3 g/L of adsorbents,OX-nZVI exhibited faster phosphate removal rate(0.11 g/mg/min)and lower residual phosphate level(0.02 mg P/L)than nZVI(0.055 g/mg/min and 0.19 mg P/L).This study sheds light on the importance of site manipulation in the development of high-performance adsorbents,and offers a facile surface modification strategy to prepare superior iron-basedmaterials for advanced phosphate removal.展开更多
Oxalic acid salts(oxalate)were recently developed as C1 synthon,potent single-electron-transfer(SET)reductant,and hole scavengers via generation of CO_(2) and CO_(2) radical anion(CO_(2)·^(-))under mild photochem...Oxalic acid salts(oxalate)were recently developed as C1 synthon,potent single-electron-transfer(SET)reductant,and hole scavengers via generation of CO_(2) and CO_(2) radical anion(CO_(2)·^(-))under mild photochemical conditions.A series of challenging reductive transformations were realized with oxalic dianion under catalytic photoredox conditions or through an electron-donor-acceptor(EDA)complex formation process.As a chemical intermediate for carbon capture and utilization(also a cheap and readily available reagent),oxalate salts could release one electron easily(E_(ox)=+0.06 V vs.SCE)via visible-light irradiation to give CO_(2) and CO_(2)·^(-) and therefore opened a new arena for reductive carboxylation reactions with highly expanded reaction diversity and chemical space to realize challenging C-X bond activation,alkenes cross coupling,and reductive carboxylation of unsaturated chemical bonds in a more sustainable and efficient way.This review features the recently developed aspects with oxalate salts and also an outlook for its further application in organic radical transformations.展开更多
Pathological mineralizations in breast lesions are closely associated with disease progression and serves as a critical diagnostic indicator.However,systematic understanding remains lacking regarding the phase categor...Pathological mineralizations in breast lesions are closely associated with disease progression and serves as a critical diagnostic indicator.However,systematic understanding remains lacking regarding the phase categories,distribution patterns,and proportional occurrences of mineral phases across different breast lesion types.The diagnostic implications of specific phases,such as calcium oxalate,for distinguishing benign and malignant lesions remain controversial.This study employed polarizing microscopy,environmental scanning electron microscopy(SEM)with energy dispersive spectroscopy(EDS),transmission electron microscopy(TEM),Fourier transform infrared spectroscopy(FTIR),and Raman spectroscopy to analyze the phase composition of 61 mineralized samples from three lesion types:Invasive carcinoma,carcinoma in situ and benign lesions.Results demonstrate that breast lesion mineralizations predominantly comprise calcium phosphates,including hydroxyapatite(HA),amorphous calcium phosphate(ACP),and whitlockite,occasionally accompanied by calcium oxalate(monohydrate or dihydrate).Distinct distribution patterns and proportional occurrences of minerals were observed among the three types of lesion mineralizations.HA,as the predominant phase,was ubiquitously present across all three lesion categories.ACP,a mineralization precursor phase,emerged during early mineralization stages across all lesion types.Notably,whitlockite exclusively occurred in benign lesions and carcinoma in situ,with higher prevalence in benign cases,suggesting a progressive decline in Mg^(2+)concentration within the lesion microenvironment as malignancy advances.Calcium oxalate coexisted with HA in mineralized regions across all lesion types,and its presence in invasive carcinoma specimens warrants heightened clinical attention.展开更多
The hydrogenation of dimethyl oxalate(DMO)to ethanol(Et OH)represents a promising avenue for syngas conversion and plays a pivotal role in advancing sustainable energy economies.Nevertheless,designing catalysts with h...The hydrogenation of dimethyl oxalate(DMO)to ethanol(Et OH)represents a promising avenue for syngas conversion and plays a pivotal role in advancing sustainable energy economies.Nevertheless,designing catalysts with high Et OH yields at low temperatures remains a significant challenge.This study introduces an efficient catalyst featuring a rich SiO_(2)-Ni_(3)Mo_(3)N interface,which achieved a remarkable 97.5%Et OH yield at 210°C and 2 MPa.Impressively,an Et OH yield of 95%was also obtained at 210°C and 1.5 MPa.The research demonstrates that the addition of SiO_(2)fosters the development of a rich SiO_(2)-Ni_(3)Mo_(3)N interface,which enhances the concentration of Lewis acid sites(L-acid)and Brønsted acids sites(B-acid)within the catalyst.This enhancement promotes the adsorption of raw material and intermediate products while increasing H_(2)adsorption,thereby boosting the catalyst's deep hydrogenation capacity.Density functional theory(DFT)simulations indicate that SiO2incorporation modifies the catalyst's metal d-band center through electron transfer,increasing its adsorption capability for raw materials and intermediates and facilitating Et OH production.Consequently,this study achieves high Et OH yields at low temperatures,advances the industrialization process of syngas to Et OH conversion,and offers novel insights into constructing highly active catalytic interfaces for DMO hydrogenation.展开更多
Lanthanum oxalate hydrate La2（C2O4）3·10H2O,the precursor of La2O3 ultrafine powders,was prepared by impinging stream reactor method with PEG 20000 as surfactant.Thermal decomposition of La2（C2O4）3·10H2O ...Lanthanum oxalate hydrate La2（C2O4）3·10H2O,the precursor of La2O3 ultrafine powders,was prepared by impinging stream reactor method with PEG 20000 as surfactant.Thermal decomposition of La2（C2O4）3·10H2O from room temperature to 900 °C was investigated and intermediates and final solid products were characterized by FTIR and DSC-TG.Results show that the thermal decomposition process consists of five consecutive stage reactions.Flynn-Wall-Ozawa（FWO） and Kissinger-Akahira-Sunose（KAS） methods were implemented for the calculation of energy of activation（E）,and the results show that E depends on α,demonstrating that the decomposition reaction process of the lanthanum oxalate is of a complex kinetic mechanism.The most probable mechanistic function,G（α）=[1-（1＋α）1/3]2,and the kinetic parameters were obtained by multivariate non-linear regression analysis method.The average E-value that is compatible with the kinetic model is close to value which was obtained by FWO and KAS methods.The fitting curve matches the original TG curve very well.展开更多
Red-mud is the residue from the Bayer process, in which the iron minerals should be removed before red-mud is used to produce refractory materials. The iron minerals in red-mud were extracted by oxalic acid solution. ...Red-mud is the residue from the Bayer process, in which the iron minerals should be removed before red-mud is used to produce refractory materials. The iron minerals in red-mud were extracted by oxalic acid solution. The content of Fe （calculated in Fe203） in red-mud was reduced from 17.6% to less than 1% after being treated by 1 mol/L oxalic acid solution at 75 ℃ for 2 h. The Fe（Ⅲ） oxalate solution obtained was then irradiated by UV light, resulting in the precipitation of Fe（Ⅱ） oxalate. Under UV photocatalysis, more than 90% of Fe（Ⅲ） oxalate in the extracted solution was transformed into the precipitation of Fe（Ⅱ） oxalate crystallite （fl-FeC2O4·2H2O）. The filtrate from the Fe（Ⅱ） oxalate precipitate filtration could be reused in the next cycle. The mechanism ofUV photocatalysis precipitation was also discussed.展开更多
A pot experiment was conducted to study the influences of foliar application of glycine,alanine,lysine,and glutamic acid in 200 mg/kg or 500 mg/kg upon the quality and enzyme activity of flowering Chinese cabbage（Bra...A pot experiment was conducted to study the influences of foliar application of glycine,alanine,lysine,and glutamic acid in 200 mg/kg or 500 mg/kg upon the quality and enzyme activity of flowering Chinese cabbage（Brassica parachinensis Bailey）.The results showed that all the application of these four amino acids could increase the yield of flowering Chinese cabbage,significantly raise the content of soluble sugar,and reduce the accumulation of nitrate.The applications of three other amino acids except alanine can increase the content of soluble proteins and decrease the accumulation of oxalic acid.However,the application of amino acid has insignificant influences on the SPAD number of chlorophyll,and causes the decrease of Vitamin C content.Meanwhile,the application of amino acid can improve the activity of nitrate reductase（NR） and glutamate dehydrogenase（GDH） as well.It shows that the application of amino acid is beneficial to improve ammonia metabolism,reduce the accumulation of nitrate and oxalic acid,increase the content of soluble sugar and soluble proteins,and improve the quality of flowering Chinese cabbage.展开更多
According to the principles of simultaneous equilibrium and mass equilibrium, a series of thermodynamic equilibrium equations in Ni（II）-Co（II）-C2O4^2--NH3-NH4^＋-H2O system at ambient temperature were deduced. The...According to the principles of simultaneous equilibrium and mass equilibrium, a series of thermodynamic equilibrium equations in Ni（II）-Co（II）-C2O4^2--NH3-NH4^＋-H2O system at ambient temperature were deduced. The diagrams of logarithm ion concentrations versus pH values at different solution compositions were drawn. The results show that Ni^2＋ and Co^2＋ can completely precipitate at pH less than 5.0 and the predefined Ni/Co ratios can be well kept in the precursor. The precursor morphology is granular aggregation. However, rod aggregation precursor is obtained in the pH range of 5.0-8.0, and fibre-shape precursor is got at pH value higher than 8.0. The Ni/Co ratios in the above two precursors are not reproduced as that in the feed due to the formhtion of multi-coordinated Ni（NH3）n^2＋ and Co（NH3）n^2＋ （n=1-6）. Modification of precipitation medium is favorable for the precursors to keep the predefined Ni/Co ratios of the feed in the pH range of 2.0-8.6. Meanwhile, the precursors with fibrous morphology can be obtained.展开更多
Rate constants for the reactions of NO3 and SO4 radicals with oxalic acid and oxalate anions in aqueous solution have been measured using pulse radiolysis and laser flash photolysis.
文摘Silver-ceramics (Ag2MO2)(M=Co, Ni, or Cu) were prepared through thermal decompositionof coprecipitated oxalates. Pellets of these materials were annealed at 350℃ for different timeperiods up to 5 h. The effect of annealing time on the transport properties was studied. IR andX-ray spectra were also studied.
基金supported by the National Natural Science Foundation of China(22122106,22071158,21971171,and21875146)National Research Foundation of Korea(NRF)funded by the Ministry of Science and International Cooperation of Technology(2019R1A2C3005530)。
文摘Birefringent materials with large optical anisotropy,which can be used to modulate the polarization of light,play a key role in laser techniques and science.However,the exploration studies of new,superior birefringent materials develop extremely slowly due to the lack of effective guidelines for rational design.Herein,three antimony(Ⅲ)fluoride oxalates,namely,Na_(2)Sb_(2)(C_(2)O_(4))F_(6),K_(2)Sb_(2)(C_(2)O_(4))F_(6),and Cs_(2)Sb_(2)-(C_(2)O_(4))_(2)F_(4)·H_(2)O,were successfully synthesized through a rational combination ofπ-conjugated C_(2)O_(4)^(2-)anions and Sb^(3+)cations with stereochemically active lone pairs.These oxalates feature unique quasi-one-dimensional chain structures that induce large optical anisotropy.Remarkably,Cs_(2)Sb_(2)(C_(2)O_(4))_(2)-F_(4)·H_(2)O exhibits the largest birefringence(0.325@546 nm)among all reported antimony(Ⅲ)-based oxysalts.Detailed structural analysis and theoretical calculations confirmed that the optical anisotropy of these oxalates could be tuned through the synergetic interactions of templated cations and anionic functional groups.This work may open the door to efficiently designing excellent birefringent materials and guide the further discovery of other novel structure-driven functional materials.
基金financially supported by National Key R&D Program of China (2025YFE0100300)the National Natural Science Foundation of China (52202293 and 52330004)the Fundamental Research Funds for the Central Universities (WUT: 2023IVA075 and 2023IVB009)。
文摘All-perovskite tandem solar cells(ATSCs) have the potential to surpass the Shockley-Queisser efficiency limit of conventional single-junction devices. However, the performance and stability of mixed tin–lead(Sn–Pb) perovskite solar cells(PSCs), which are crucial components of ATSCs, are much lower than those of lead-based perovskites. The primary challenges include the high crystallization rate of perovskite materials and the susceptibility of Sn^(2+) oxidation, which leads to rough morphology and unfavorable p-type self-doping. To address these issues, we introduced ethylhydrazine oxalate(EDO) at the perovskite interface, which effectively inhibits the oxidation of Sn^(2+) and simultaneously enhances the crystallinity of the perovskite. Consequently, the EDO-modified mixed tin-lead PSCs reached a power conversion efficiency(PCE) of 21.96% with high reproducibility. We further achieved a 27.58% efficient ATSCs by using EDO as interfacial passivator in the Sn-Pb PSCs.
文摘The structure-performance relationship of Cu/Al_(2)O_(3) catalysts in the hydrogenation of diethyl oxalate(DEO)for the synthesis of alcohol ether esters has been investigated by various characterization techniques including XRD,XPS,N2O titration,and 27Al MAS-NMR.The results showed that when the crystal configurations of Al_(2)O_(3) were the same,increasing the specific surface area could effectively refine the size of copper nanoparticles(Cu NPs),and ultimately improve the conversion of DEO.Meanwhile,the smaller size ofγ-Al_(2)O_(3)(HSAl and SBAl)loaded Cu NPs promotes the reaction towards the deep hydrogenation to produce ethanol(EtOH)and ethylene glycol(EG).Besides,the larger size of Cu NPs on the surface of amorphous Al_(2)O_(3)(HTAl and SolAl)resulted in a lower conversion rate,where ethyl glycolate(Egly)is the main product.Despite there are differences in Al^(3+)ionic coordination in Al_(2)O_(3) with different crystal structures,the experimental data showed that the differences in Al^(3+)ionic coordination did not significantly affect the catalytic performance in the hydrogenation reaction.The formation of alcohol-ether ester chemicals is critically dependent on the interactions between Cu sites and acidic sites.Among them,EG and EtOH were dehydrated to form 2-ethoxyethanol via the SN2 mechanism,while Egly and EtOH were reacted to form ethyl ethoxyacetate(EEA)via the SN2 mechanism.This study provides a theoretical basis for the optimization of the coal-based glycol processes to achieve a diversified product portfolio.
文摘Objective:Several therapeutic modalities for the prevention of calcium oxalate(CaOx)stones have been studied,but only a select few of these modalities have been incorporated into the American Urological Association guidelines.Our study aimed to organize and interrogate existing research that may be promising for CaOx prevention.Methods:A literature search was conducted using MEDLINE and Embase from inception to November 16,2022.Our study population included adults with or without a history of CaOx kidney stones.Studies in which patients were treated with pharmacotherapies,herbal supplements,or uncategorized research chemicals that are not included in the current American Urological Association guidelines for preventing CaOx stones were included.Nonoriginal research was excluded.Results:Out of the 6155 identified articles,38 were included in the final analysis.The five distinct categories of interventions for stone prevention were“medications”,“herbal supplements”,“food and macronutrients”,“micronutrients”,and“enzymes and probiotics”.Modalities that were found to reduce known urinary risk factors were tolvaptan,cranberry juice,magnesium citrate,oxalate-degrading enzyme ALLN-177,and malic acid.Prophylaxis that reduced stone formation were sodium-glucose cotransporter-2 inhibitors,eicosapentaenoic acid,ethane-1-hydroxy-1,1-disphosphonate.Therapies that reduced urinary risk factors and stone formation were Phyllanthus niruri,rice bran,and magnesium hydroxide.Conclusion:Several of the identified therapies may provide prophylactic benefits for CaOx stone formation and may be useful for inclusion in guidelines for kidney stone prevention.
文摘Molybdenum carbide has shown great potential in various hydrogenation reactions,and serves as a primary active species for synthesis of ethanol from dimethyl oxalate hydrogenation process which is a crucial step in the efficient utilization of coal resources.In this study,a molybdenum carbide catalyst with a three-dimensional mesh-like hollow structure and lattice defects was carefully designed.The MoO_(3)precursor with abundant oxygen vacancies and defects was prepared by flame spray pyrolysis,and a structural modifier,Cu,was introduced by sputtering.The Cu deposited by sputtering affected the carburization and phase evolution processes.A three-dimensional mesh-like hollow structure composed of defective molybdenum carbide is formed,with theβ-Mo_(2)C exhibiting lattice distortions and defects.This defectiveβ-Mo_(2)C exhibits high reactivity,and facilitates the C=O hydrogenation process,showing a high reactivity of 83.1%yield in the hydrogenation of dimethyl oxalate.This work provides a new approach to the design and application of molybdenum carbide catalysts.
基金supported by USDA-SCRI(Grant Nos.2017-51181-26830 and 2023-51181-41321)USDA-AMS SCMP(Grant No.16SCCMAR0001)+1 种基金Arkansas Department of Agriculture SCBGP(Grant No.AM22SCBGPAR1130-00)USDA NIFA Hatch project(Grant Nos.ARK0VG2018 and ARK02440).
文摘Oxalate content in spinach is a key trait of interest due to its relevance to human health.Understanding the genetic basis of it can facilitate the development of spinach varieties with reduced oxalate levels.In pursuit of understanding the genetic determinants,a diverse panel comprising 288 spinach accessions underwent thorough phenotyping of oxalate content and were subjected to whole-genome resequencing,resulting in a comprehensive dataset encompassing 14386 single-nucleotide polymorphisms(SNPs).Leveraging this dataset,we conducted a genome-wide association study(GWAS)to identify noteworthy SNPs associated with oxalate content.Furthermore,we employed genomic prediction(GP)via cross-prediction,utilizing five GP models,to assess genomic estimated breeding values(GEBVs)for oxalate content.The observed normal distribution and the wide range of oxalate content,exceeding 600.0 mg$100 g^(-1),underscore the complex and quantitative nature of this trait,likely influenced by multiple genes.Additionally,our analysis revealed distinct stratification,delineating the population into four discernible subpopulations.Furthermore,GWAS analysis employing five models in GAPIT 3 and TASSEL 5 unveiled nine significant SNPs(four SNPs on chromosome 1 and five on chromosome 5)associated with oxalate content.These loci exhibited associations with six candidate genes,which might have potential contribution to oxalate content regulation.Remarkably,our GP models exhibited notable predictive abilities,yielding average accuracies of up to 0.51 for GEBV estimation.The integration of GWAS and GP approaches offers a holistic comprehension of the genetic underpinnings of oxalate content in spinach.These findings offered a promising avenue for the development of spinach cultivars and hybrids optimized for oxalate levels,promoting consumer health.
基金supported by Guangxi Science and Technology Major Program(GuikeAA23062018)the Academic Newcomer Award Project of Guangxi University(2025GXUXSXR07)。
文摘In this paper,the research progress of Cu-based catalyst and the activity enhancement strategies in the hydrogenation of dimethyl oxalate(DMO)to ethylene glycol(EG)was reviewed.As a green and economical ethylene glycol production path,the core of DMO hydrogenation of EG lies in the rational design and optimization of catalysts.This paper first introduces the background of the DMO hydrogenation system EG significance and the important effect of Cu-based catalyst in the reaction,particularly emphasizing the coordination with the Cu^(+)-Cu^(0) species catalytic effect.Then,many factors affecting the activity of Cu-based catalysts were analyzed in detail,including the equilibrium effect between Cu^(0) and Cu+species,the surface dispersion of Cu species,the interaction between metal and support,and the morphology effect of the catalyst.Regarding strategies for improving catalyst performance,this paper summarized effective measures such as optimizing support structure,adding promoters and optimizing preparation methods,and demonstrated the practical application effects of these strategies through representative catalyst examples.In addition,this paper also discusses the complex relationship between the influencing factors and catalyst performance.It points out the key directions for future research,with in-depth exploration of the correlation between catalyst structure and performance,the development of new catalysts,and the application of machine learning and big data technology in the catalyst research and development.In summary,this paper provides comprehensive theoretical guidance and practical reference for the performance optimization of Cu-based catalysts for DMO hydrogenation to EG.
基金The Sherman Fairchild Foundation Undergraduate Research GrantThe National Science Foundation Award#1912400:HBCU-UP Implementation Project:Improving Minority Participation and Completion through STEM at Dillard University(IMPACTS@DU Ⅱ)Dillard University Endowed Professorship,funds。
文摘Abstract:In today’s economy,determining accessible and affordable techniques to remove Heavy Metals(HMs)from wastewater is crucial.Activated carbon is highly effective in adsorbing HMs due to its large surface area and porous structure.It works by attracting and binding HM ions to its surface.Okoubaka is known for its medicinal properties and some studies suggest it has detoxifying effects.However,its specific role in HM removal would likely involve binding mechanisms like other plant-based materials.This study examines the efficiency of activated charcoal,charred versus uncharred Okoubaka plant materials,eggshells and oxalic acid to remove HMs like copper,lead,and zinc from contaminated water.
基金DGAPA (Dirección General de Asuntos del Personal Acadé-mico) under Projects No. IA103521, IA209223 and IN111722Supercomputing Department of the Universidad Nacional Autónoma de México for the computing resources under Projects No. LANCAD-UNAM-DGTIC-427 and LANCAD-UNAM-DGTIC-370CONAHCYT-México for their postdoctoral fellowships。
文摘Herein,we present the electrocatalytic four-electron hydrogenation of oxalic acid into glycolic acid using black TiO_(2)as an electrocatalyst.Oxalic acid is an abundant compound found in several sources of organic waste.The results showed a high selectivity of black TiO_(2)toward glycolic acid,with the formation of glyoxylic acid being the rate-limiting step (glyoxylic acid is the two-electron intermediate).The highest Faradaic efficiency (FE) of 69.6%±8.3% was achieved at 10.2 mA cm^(-2)in 4 h of electrolysis using an H-type cell operated at room temperature,with 50.2%±3.8% of oxalic acid conversion (degradation kinetic constant k=0.0042±0.0001 min-1),58.8%±7.0%of reaction yield and 1.2±0.18 g L-1of glycolic acid production.A theoretical model of black TiO_(2)coming from anatase TiO_(2)was implemented by introducing Ti3+defects,which gave black TiO_(2)the theoretical capability to easily transform oxalic acid into glycolic acid as experimentally observed.The reaction mechanism was supported and described in detail by density functional theory calculations,which revealed that surface Ti^(3+)states were the main catalytic sites.This is the first time that a detailed step-by-step mechanism at the atomic level has been proposed for this electrocatalytic reaction,which represents a valuable contribution to the understanding of this process of high energy/environmental interest.This is also the first time that black TiO_(2)has been used as an electrocatalyst for this sustainable process.
基金supported by the National Natural Science Foundation of China(21878227,22278309)。
文摘Ethanol synthesis via dimethyl oxalate hydrogenation has garnered increasing attention in the fields of syngas utilization.Althoughε-Fe_(2)C has been identified as a promising active species for DMO hydrogenation to ethanol,its formation is kinetically challenging during carbonization.In this work,a Fe_(4)N phase was first synthesized by pretreating a 30Fe/SiO_(2)catalyst in an ammonia environment,followed by carbonization in a methanol-H_(2) flow to obtain ε-Fe_(2)C as the active phase.Fe_(4)N,rather than Fe-O-Si,facilitates the transformation into iron carbide during the carbonization process.The transformation pathway of iron nitride(Fe_(x)N)is mediated by intermediate iron carbonyl species(Fe-CO),ultimately leading to the formation of iron carbide as the active phase.The resulting catalyst exhibited 40 times higher catalytic activity than the untreated catalyst in DMO hydrogenation.Combined structure properties and DFT calculation revealed that the lower energy barrier ofε-Fe_(2)C for ester hydrogenation underpins/strengthens its superior performance,while the STY of ε-Fe_(2)C is 2.8 times that ofε'-Fe_(2.2)C and 58 times that ofχ-Fe_(5)C_(2).This study provides a novel strategy for designing highly efficient iron carbide catalysts for the esters hydrogenation system.
基金supported by the National Key Research and Development Program of China(Nos.2022YFA1205602,and 2023YFC3707801)the National Natural Science Foundation of China(Nos.U22A20402,22376073,21936003 and 22306119)China Postdoctoral Science Foundation(No.2023T160419).
文摘Nano zero-valent iron(nZVI)is a promising phosphate adsorbent for advanced phosphate removal.However,the rapid passivation of nZVI and the low activity of adsorption sites seriously limit its phosphate removal performance,accounting for its inapplicability to meet the emission criteria of 0.1 mg P/L phosphate.In this study,we report that the oxalate modification can inhibit the passivation of nZVI and alter the multi-stage phosphate adsorption mechanism by changing the adsorption sites.As expected,the stronger antipassivation ability of oxalate modified nZVI(OX-nZVI)strongly favored its phosphate adsorption.Interestingly,the oxalate modification endowed the surface Fe(III)sites with the lowest chemisorption energy and the fastest phosphate adsorption ability than the other adsorption sites,by in situ forming a Fe(III)-phosphate-oxalate ternary complex,therefore enabling an advanced phosphate removal process.At an initial phosphate concentration of 1.00 mg P/L,pH of 6.0 and a dosage of 0.3 g/L of adsorbents,OX-nZVI exhibited faster phosphate removal rate(0.11 g/mg/min)and lower residual phosphate level(0.02 mg P/L)than nZVI(0.055 g/mg/min and 0.19 mg P/L).This study sheds light on the importance of site manipulation in the development of high-performance adsorbents,and offers a facile surface modification strategy to prepare superior iron-basedmaterials for advanced phosphate removal.
基金financially supported by the Jiangsu Province Shuangchuang Ph.D.award(No.JSSCBS20211267,Pei Xu)the Natural Science Research Project of Jiangsu Universities(No.23KJB150037,Pei Xu)+2 种基金sponsored by the Jiangsu Specially-Appointed Professor Program(Xu Zhu)the Start-up Funding provided by Xuzhou Medical UniversityThe Public Experimental Research Center of Xuzhou Medical University is also acknowledged。
文摘Oxalic acid salts(oxalate)were recently developed as C1 synthon,potent single-electron-transfer(SET)reductant,and hole scavengers via generation of CO_(2) and CO_(2) radical anion(CO_(2)·^(-))under mild photochemical conditions.A series of challenging reductive transformations were realized with oxalic dianion under catalytic photoredox conditions or through an electron-donor-acceptor(EDA)complex formation process.As a chemical intermediate for carbon capture and utilization(also a cheap and readily available reagent),oxalate salts could release one electron easily(E_(ox)=+0.06 V vs.SCE)via visible-light irradiation to give CO_(2) and CO_(2)·^(-) and therefore opened a new arena for reductive carboxylation reactions with highly expanded reaction diversity and chemical space to realize challenging C-X bond activation,alkenes cross coupling,and reductive carboxylation of unsaturated chemical bonds in a more sustainable and efficient way.This review features the recently developed aspects with oxalate salts and also an outlook for its further application in organic radical transformations.
基金financially supported by the National Natural Science Foundation of China(41772033,41272048).
文摘Pathological mineralizations in breast lesions are closely associated with disease progression and serves as a critical diagnostic indicator.However,systematic understanding remains lacking regarding the phase categories,distribution patterns,and proportional occurrences of mineral phases across different breast lesion types.The diagnostic implications of specific phases,such as calcium oxalate,for distinguishing benign and malignant lesions remain controversial.This study employed polarizing microscopy,environmental scanning electron microscopy(SEM)with energy dispersive spectroscopy(EDS),transmission electron microscopy(TEM),Fourier transform infrared spectroscopy(FTIR),and Raman spectroscopy to analyze the phase composition of 61 mineralized samples from three lesion types:Invasive carcinoma,carcinoma in situ and benign lesions.Results demonstrate that breast lesion mineralizations predominantly comprise calcium phosphates,including hydroxyapatite(HA),amorphous calcium phosphate(ACP),and whitlockite,occasionally accompanied by calcium oxalate(monohydrate or dihydrate).Distinct distribution patterns and proportional occurrences of minerals were observed among the three types of lesion mineralizations.HA,as the predominant phase,was ubiquitously present across all three lesion categories.ACP,a mineralization precursor phase,emerged during early mineralization stages across all lesion types.Notably,whitlockite exclusively occurred in benign lesions and carcinoma in situ,with higher prevalence in benign cases,suggesting a progressive decline in Mg^(2+)concentration within the lesion microenvironment as malignancy advances.Calcium oxalate coexisted with HA in mineralized regions across all lesion types,and its presence in invasive carcinoma specimens warrants heightened clinical attention.
基金the financial support from the National Natural Science Foundation of China(No.21962015)the Bingtuan Graduate Innovation Project 2024(No.BTYJXM-2024-K12)。
文摘The hydrogenation of dimethyl oxalate(DMO)to ethanol(Et OH)represents a promising avenue for syngas conversion and plays a pivotal role in advancing sustainable energy economies.Nevertheless,designing catalysts with high Et OH yields at low temperatures remains a significant challenge.This study introduces an efficient catalyst featuring a rich SiO_(2)-Ni_(3)Mo_(3)N interface,which achieved a remarkable 97.5%Et OH yield at 210°C and 2 MPa.Impressively,an Et OH yield of 95%was also obtained at 210°C and 1.5 MPa.The research demonstrates that the addition of SiO_(2)fosters the development of a rich SiO_(2)-Ni_(3)Mo_(3)N interface,which enhances the concentration of Lewis acid sites(L-acid)and Brønsted acids sites(B-acid)within the catalyst.This enhancement promotes the adsorption of raw material and intermediate products while increasing H_(2)adsorption,thereby boosting the catalyst's deep hydrogenation capacity.Density functional theory(DFT)simulations indicate that SiO2incorporation modifies the catalyst's metal d-band center through electron transfer,increasing its adsorption capability for raw materials and intermediates and facilitating Et OH production.Consequently,this study achieves high Et OH yields at low temperatures,advances the industrialization process of syngas to Et OH conversion,and offers novel insights into constructing highly active catalytic interfaces for DMO hydrogenation.
基金Project (IRT0974) supported by Program for Changjiang Scholars and Innovative Research Team in University,ChinaProject (50974098) supported by the National Natural Science Foundation of China
文摘Lanthanum oxalate hydrate La2（C2O4）3·10H2O,the precursor of La2O3 ultrafine powders,was prepared by impinging stream reactor method with PEG 20000 as surfactant.Thermal decomposition of La2（C2O4）3·10H2O from room temperature to 900 °C was investigated and intermediates and final solid products were characterized by FTIR and DSC-TG.Results show that the thermal decomposition process consists of five consecutive stage reactions.Flynn-Wall-Ozawa（FWO） and Kissinger-Akahira-Sunose（KAS） methods were implemented for the calculation of energy of activation（E）,and the results show that E depends on α,demonstrating that the decomposition reaction process of the lanthanum oxalate is of a complex kinetic mechanism.The most probable mechanistic function,G（α）=[1-（1＋α）1/3]2,and the kinetic parameters were obtained by multivariate non-linear regression analysis method.The average E-value that is compatible with the kinetic model is close to value which was obtained by FWO and KAS methods.The fitting curve matches the original TG curve very well.
基金Project (2010AA101703) supported by the National Hi-tech Research and Development Program of China
文摘Red-mud is the residue from the Bayer process, in which the iron minerals should be removed before red-mud is used to produce refractory materials. The iron minerals in red-mud were extracted by oxalic acid solution. The content of Fe （calculated in Fe203） in red-mud was reduced from 17.6% to less than 1% after being treated by 1 mol/L oxalic acid solution at 75 ℃ for 2 h. The Fe（Ⅲ） oxalate solution obtained was then irradiated by UV light, resulting in the precipitation of Fe（Ⅱ） oxalate. Under UV photocatalysis, more than 90% of Fe（Ⅲ） oxalate in the extracted solution was transformed into the precipitation of Fe（Ⅱ） oxalate crystallite （fl-FeC2O4·2H2O）. The filtrate from the Fe（Ⅱ） oxalate precipitate filtration could be reused in the next cycle. The mechanism ofUV photocatalysis precipitation was also discussed.
基金Supported by National Scientific and Technological Supporting Project(2008BADA4B04-09)Guangdong Province Scientific and Technological Project(2008A020100017)Guangdong Province Department of Finance Project[(2006)143]~~
文摘A pot experiment was conducted to study the influences of foliar application of glycine,alanine,lysine,and glutamic acid in 200 mg/kg or 500 mg/kg upon the quality and enzyme activity of flowering Chinese cabbage（Brassica parachinensis Bailey）.The results showed that all the application of these four amino acids could increase the yield of flowering Chinese cabbage,significantly raise the content of soluble sugar,and reduce the accumulation of nitrate.The applications of three other amino acids except alanine can increase the content of soluble proteins and decrease the accumulation of oxalic acid.However,the application of amino acid has insignificant influences on the SPAD number of chlorophyll,and causes the decrease of Vitamin C content.Meanwhile,the application of amino acid can improve the activity of nitrate reductase（NR） and glutamate dehydrogenase（GDH） as well.It shows that the application of amino acid is beneficial to improve ammonia metabolism,reduce the accumulation of nitrate and oxalic acid,increase the content of soluble sugar and soluble proteins,and improve the quality of flowering Chinese cabbage.
基金Project (20090162120080) supported by Research Fund for the Doctoral Program of Higher Education of China Project (20070410989) supported by China Postdoctoral Science Foundation+1 种基金 Project (2010FJ3012) supported by the Program of Science and Technology of Hunan Province, China Project (09JJ4028) supported by Natural Science Foundation of Hunan Province, China
文摘According to the principles of simultaneous equilibrium and mass equilibrium, a series of thermodynamic equilibrium equations in Ni（II）-Co（II）-C2O4^2--NH3-NH4^＋-H2O system at ambient temperature were deduced. The diagrams of logarithm ion concentrations versus pH values at different solution compositions were drawn. The results show that Ni^2＋ and Co^2＋ can completely precipitate at pH less than 5.0 and the predefined Ni/Co ratios can be well kept in the precursor. The precursor morphology is granular aggregation. However, rod aggregation precursor is obtained in the pH range of 5.0-8.0, and fibre-shape precursor is got at pH value higher than 8.0. The Ni/Co ratios in the above two precursors are not reproduced as that in the feed due to the formhtion of multi-coordinated Ni（NH3）n^2＋ and Co（NH3）n^2＋ （n=1-6）. Modification of precipitation medium is favorable for the precursors to keep the predefined Ni/Co ratios of the feed in the pH range of 2.0-8.6. Meanwhile, the precursors with fibrous morphology can be obtained.
文摘Rate constants for the reactions of NO3 and SO4 radicals with oxalic acid and oxalate anions in aqueous solution have been measured using pulse radiolysis and laser flash photolysis.
