Diacylglycerol(DAG)is a functional oil that can reduce body fat accumulation and postprandial triglycerides.In this study,lipase-catalyzed esterification of oleic acid with glycerol was investigated to elucidate the k...Diacylglycerol(DAG)is a functional oil that can reduce body fat accumulation and postprandial triglycerides.In this study,lipase-catalyzed esterification of oleic acid with glycerol was investigated to elucidate the kinetics and selectivity of each reaction step.1H NMR monitoring revealed equilibrated positional isomerization among acylglycerols:sn-1 monoolein comprised 97.3%of total monoacylglycerols,and sn-1,3 diolein comprised 73.3%of total diacylglycerols.Acyl migration(isomer equilibration)occurred faster than overall esterification.The observed rate constants for successive esterification steps(glycerol→monoacylglycerol,monoacylglycerol→diacylglycerol,diacylglycerol→triacylglycerol)were 0.01068,0.00615,and 0.00304 min^(-1),respectively,indicating progressively slower reaction rates for larger acylglycerol species.Furthermore,molecular distillation at 200–220℃ purified the DAG without altering its fatty acid profile.These findings establish a kinetic model of the three-step esterification and highlight the importance of acyl migration in enzymatic DAG synthesis.展开更多
The agglomeration-prone properties of metal oxide catalysts limit their catalytic efficiency in the isomerization of glucose to fructose.Herein,the hierarchical structure and abundant coordination groups of collagen f...The agglomeration-prone properties of metal oxide catalysts limit their catalytic efficiency in the isomerization of glucose to fructose.Herein,the hierarchical structure and abundant coordination groups of collagen fibers were used to anchor Zr^(4+),and a highly dispersed ZrO_(2)-nitrogen-doped carbon(ZrO_(2)-NC)composite catalyst was subsequently fabricated by calcination.For the catalytic glucose-to-fructose isomerization over ZrO_(2)-NC,fructose was obtained in 41.3%yield and 85.3%selectivity in a water-acetone solvent at 120℃ for 10 min.The electron-deficient environment of ZrO_(2)surface during charge transfer from ZrO_(2)-to-NC layer facilitated the preferential adsorption of glucose,which accelerated glucose isomerization and fructose desorption.The amphoteric catalyst triggered both proton transfer on the Bronsted base sites and the intramolecular hydride shift of glucose on the Lewis acid sites of ZrO_(2)-NC in the mixed solvent.The latter isomerization mechanism depended on the presence of acetone,which lowered the energy barrier and increased fructose yield.展开更多
Simultaneous identification and quantitative detection of phenylenediamine(PDA)isomers,including o-phenylenediamine(OPD),m-phenylenediamine(MPD),and p-phenylenediamine(PPD),are essential for environmental risk assessm...Simultaneous identification and quantitative detection of phenylenediamine(PDA)isomers,including o-phenylenediamine(OPD),m-phenylenediamine(MPD),and p-phenylenediamine(PPD),are essential for environmental risk assessment and human health protection.However,current visual detection methods can only distinguish individual PDA isomers and failed to identify binary or ternary mixtures.Herein,a highly active and ultrastable peroxidase(POD)-like CoPt graphitic nanozyme was used for naked-eye identification and colorimetric/fluorescent(FL)dual-mode quantitative detection of PDA isomers.The CoPt@G nanozyme effectively catalyzed the oxidation of OPD,MPD,PPD,OPD+PPD,OPD+MPD,MPD+PPD and OPD+MPD+PPD into yellow,colorless,lilac,yellow,yellow,wine red and reddish-brown products,respectively,in the presence of H_(2)O_(2).Thus,the MPD,PPD,MPD+PPD and OPD+MPD+PPD were easily identified based on the distinct color of their oxidation products,and the OPD,OPD+PPD,OPD+MPD could be further identified by the additional addition of MPD or PPD.Subsequently,CoPt@G/H_(2)O_(2)-,a 3,3′,5,5′-tetramethylbenzidine(TMB)/CoPt@G/H_(2)O_(2)-,and MPD/CoPt@G/H_(2)O_(2)-enabled colorimetric/FL dual-mode platforms for the quantitative detection of OPD,MPD and PPD were proposed.The experimental results illustrated that the constructed sensing platforms exhibit satisfactory sensitivity,comparable to that reported in previous studies.Finally,the evaluation of PDAs in water samples was realized,yielding satisfactory recoveries.This work expanded the application prospects of nanozymes in assessing environmental risks and protection of human security.展开更多
The study of nuclear isomers can deepen our understanding of nuclear structure and astrophysics.In this work,we have performed the ab initio calculations of isomers in the N=49 isotones.With a chiral two-plus three-nu...The study of nuclear isomers can deepen our understanding of nuclear structure and astrophysics.In this work,we have performed the ab initio calculations of isomers in the N=49 isotones.With a chiral two-plus three-nucleon force,the valence-space effective Hamiltonian was derived using the ab initio many-body perturbation theory named Q-box folded diagrams.The effective operators of electromagnetic operators andβ-decay were obtained using ■-box folded diagrams.With the effective Hamiltonian and operators,we studied the properties of the isomers,gaining a microscopic understanding of the single-particle behaviour of the isomers which we are interested in,showing the reliability of the ab initio calculations.展开更多
As Internet of Things(IoT)applications expand,Mobile Edge Computing(MEC)has emerged as a promising architecture to overcome the real-time processing limitations of mobile devices.Edge-side computation offloading plays...As Internet of Things(IoT)applications expand,Mobile Edge Computing(MEC)has emerged as a promising architecture to overcome the real-time processing limitations of mobile devices.Edge-side computation offloading plays a pivotal role in MEC performance but remains challenging due to complex task topologies,conflicting objectives,and limited resources.This paper addresses high-dimensional multi-objective offloading for serial heterogeneous tasks in MEC.We jointly consider task heterogeneity,high-dimensional objectives,and flexible resource scheduling,modeling the problem as a Many-objective optimization.To solve it,we propose a flexible framework integrating an improved cooperative co-evolutionary algorithm based on decomposition(MOCC/D)and a flexible scheduling strategy.Experimental results on benchmark functions and simulation scenarios show that the proposed method outperforms existing approaches in both convergence and solution quality.展开更多
1 Introduction Recently,the increasing demand for advanced telecommunication systems has spurred extensive research into bandpass filters(BPFs),with particular emphasis on miniaturization,reduction of insertion loss(I...1 Introduction Recently,the increasing demand for advanced telecommunication systems has spurred extensive research into bandpass filters(BPFs),with particular emphasis on miniaturization,reduction of insertion loss(IL),and enhancement of upper stopband rejection(Huang et al.,2021;Snyder et al.,2021;Lin et al.,2023;Zeng et al.,2023).展开更多
Binuclear complexes have attracted extensive attention in fields such as catalysis because of their likely bimetallic synergistic effect;however,the mechanism and factors influencing this synergism remain unclear.In t...Binuclear complexes have attracted extensive attention in fields such as catalysis because of their likely bimetallic synergistic effect;however,the mechanism and factors influencing this synergism remain unclear.In this work,six bis-β-ketoimine binuclear titanium complexes4a-4f containing different alkylthio sidearms and configurations were synthesized and characterized by nuclear magnetic resonance hydrogen spectrum(~1H-NMR),nuclear magnetic resonance carbon spectrum(^(13)C-NMR),Fourier transform infrared spectrum(FTIR),and elemental analysis.The intermetallic distances of isomeric complexes 4a,4d,4e and 4f determined through density functional theory(DFT)optimization were in the order 4a<4d<4e<4f and were found to significantly influence the catalytic performance for ethylene(co)polymerization.These complexes could efficiently catalyze ethylene polymerization and ethylene/1-hexene or ethylene/1-octene copolymerization with high activity to produce highmolecular-weight ethylene homo-and co-polymers.Among the three binuclear titanium complexes 4a-4c with similar structures but different lengths of alkylthio sidearms,complex 4a,which contained the shortest methylthio sidearm,exhibited the highest activity for ethylene polymerization and copolymerization with 1-hexene or 1-octene.Additionally,for ethylene/1-hexene or ethylene/1-octene copolymerization,it showed the highest comonomer incorporation compared with propylthio(4b)and octylthio(4c)derivatives because of the smaller steric hindrance of the methyl group in 4a and the more open coordination space for vinyl monomers.Furthermore,among the isomeric complexes 4a,4d,4e and4f,complex 4a with the shortest bimetallic distance also exhibited the highest activity towards ethylene(co)polymerization,and the highest 1-hexene or 1-octene incorporation in comparison with its regioisomeric counterparts 4d,4e and p-phenyl-bridged analog 4f,owing to a more appropriate bimetallic distance that is conducive to a synergistic effect.展开更多
Six coordination polymers based on 9,10-di(pyridine-4-yl)-anthracene(DPA)and 1,6-di(1H-imidazol-1-yl)pyrene(DIP)were obtained by solvothermal reactions.{[Zn(DPA)Cl_(2)]·DMF·2H_(2)O}n(1)and{[Zn_(1.5)(DPA)_(1....Six coordination polymers based on 9,10-di(pyridine-4-yl)-anthracene(DPA)and 1,6-di(1H-imidazol-1-yl)pyrene(DIP)were obtained by solvothermal reactions.{[Zn(DPA)Cl_(2)]·DMF·2H_(2)O}n(1)and{[Zn_(1.5)(DPA)_(1.5)Cl_(3)]·5H_(2)O}n(2)are framework isomers,which both contain zigzag chains formed by DPA,Zn^(2+),and Cl-.The zigzag chains in 1 are further assembled by C—H…Cl interactions into layers,and these layers exhibit two different orientations,displaying a rare 2D to 3D interpenetration mode.The zigzag chains in 2 are parallelly arranged.{[Zn_(3)(DPA)_(3)Br_(6)]·2DMF·_(1.5)H_(2)O}n(3)is isostructural to 2.3 was obtained using ZnBr_(2)instead of ZnCl_(2).[M(DPA)(formate)_(2)(H_(2)O)_(2)]n[M=Co(4),Cu(5)]are isostructural,contain chain structures formed by DPA,Cu^(2+)/Co^(2+),and for-mate ions,which were formed in situ in the solvothermal reaction.{[Zn(DIP)_(2)Cl]ClO_(4)}n(6)contains a layer structure formed by DIP and Zn^(2+).Free DPA and DIP ligands exhibited high fluorescence at room temperature,and coordina-tion polymers 3 and 6 displayed enhanced fluorescent emissions.展开更多
Fully utilizing renewable biomass energy is important for saving energy,reducing carbon emissions,and mitigating climate change.As the main hydrolysate of cellulose,a primary component of lignocellulose,glucose could ...Fully utilizing renewable biomass energy is important for saving energy,reducing carbon emissions,and mitigating climate change.As the main hydrolysate of cellulose,a primary component of lignocellulose,glucose could be employed as a starting material to prepare some other functional derivatives for improving the value of biomass resources.The isomerization of glucose to produce fructose is an important intermediate process during numerous high-value-added chemical preparations.Therefore,the development of efficient and selective catalysts for glucose isomerization is of great significance.Currently,glucose isomerase catalysts are limited by the harsh conditions required for microbial activity,which restricts further improvements in fructose yield.Additionally,heterogeneous Bronsted-base and Lewis-acid catalysts commonly employed in chemical isomerization methods often lead to the formation of undesirable by-products,resulting in reduced selectivity toward fructose.This study has demonstrated that lithium-loaded heterogeneous catalysts possess excellent isomerization capabilities under mild conditions.A highly efficient Li-C_(3)N_(4) catalyst was developed,achieving a fructose selectivity of 99.9% and a yield of 42.6% at 60℃ within 1.0 h-comparable to the performance of the enzymatic method.Characterization using X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),proton nuclear magnetic resonance(^(1)H NMR),and inductively coupled plasma(ICP)analyses confirmed that lithium was stably incorporated into the g-C_(3)N_(4) framework through the formation of Li-N bonds.Further investigations using CO_(2) temperature-programmed desorption(CO_(2)-TPD),in situ Fourier-transform infrared spectroscopy(FT-IR)and 7Li magic angle spinning nuclear magnetic resonance(^(7)Li MAS NMR)indicated that the isomerization proceeded via a base-catalyzed mechanism.The Li species were found to interact with hydroxyl groups generated through hydrolysis and simultaneously coordinated with nitrogen atoms in the C_(3)N_(4) matrix,resulting in the formation of Li-N_(6)-H_(2)O active sites.These active sites facilitated the deprotonation of glucose to form an enolate intermediate,followed by a proton transfer step that generated fructose.This mechanism not only improved the efficiency of fructose production but also provided valuable insight into the catalytic role of lithium within the isomerization process.展开更多
In this study,a pair of dicarboxylic acids as cis-trans isomerism—citraconic acid(CA)and mesaconic acid(MA),was incorporated into polymeric networks of poly(N-isopropylacrylamide)(PNIPAM)-based core-shell microgels v...In this study,a pair of dicarboxylic acids as cis-trans isomerism—citraconic acid(CA)and mesaconic acid(MA),was incorporated into polymeric networks of poly(N-isopropylacrylamide)(PNIPAM)-based core-shell microgels via semi-batch precipitation polymerization.We demonstrated that the pH-temperature dual responsiveness of the core-shell microgels is highly correlated with the structure and position of the acid isomers.Both the cis-trans molecular structure and the crosslinking position of the dicarboxylic acids significantly influenced the hydration capacity and surface charge density of the core-shell microgels.These diverse properties first influenced the swelling behavior,further affecting the interfacial behavior of the microgels,including the oil-water dynamic interfacial tension and air-water compression isotherms.Furthermore,the rheological behavior of the microgel suspensions also displayed distinct dependences on the frequency and temperature,illustrating that the cis-trans molecular structure and crosslinked position of the dicarboxylic acids also significantly influenced the interparticle clustering in the bulk solution.Our results suggest that the pH sensitivity of the cis-trans dicarboxylic acid isomer affects the ionization and surface charge distribution of the core or shell layers of individual microgels,which further determines the interparticle interaction and cooperative rearrangement at interfaces and in the bulk.展开更多
We propose a novel scheme for the population and depletion of nuclear isomers.This scheme combines the γ photons with energiesà 10 keV emitted during the interaction of a contemporary high-intensity laser pulse ...We propose a novel scheme for the population and depletion of nuclear isomers.This scheme combines the γ photons with energiesà 10 keV emitted during the interaction of a contemporary high-intensity laser pulse with a plasma and one or multiple photon beams supplied by intense lasers.Owing to nonlinear effects,two-or multiphoton absorption dominates over the conventional multistep one-photon process for an optimized γ flash.Moreover,this nonlinear effect can be greatly enhanced with the help of externally supplied low-energy photons coming from another laser.These low-energy photons act such that the effective cross-section experienced by the γ photons becomes tunable,growing with the intensity I_(0) of the beam.Assuming I_(0)~10^(18) W·cm^(-2) for the photon beam,an effective cross-section as large as 10^(-21)-10^(-28) cm^(2) for the γ photons can be achieved.Thus,with state-of-the-art 10 PW laser facilities,the yields from two-photon absorption can reach 10^(6)-10^(9) isomers per shot for selected states that are separated from their ground state by E2 transitions.Similar yields for transitions with higher multipolarities can be accommodated by multiphoton absorption with additional photons provided.展开更多
BACKGROUND Cirrhosis is a progressive condition characterized by fibrosis that can lead to severe complications and increased mortality.The mac-2 binding protein glyco-sylation isomer(M2BPGi)is a prominent biomarker f...BACKGROUND Cirrhosis is a progressive condition characterized by fibrosis that can lead to severe complications and increased mortality.The mac-2 binding protein glyco-sylation isomer(M2BPGi)is a prominent biomarker for predicting hepatocellular carcinoma(HCC)and cirrhosis-induced esophageal varices(EV).AIM To investigate thresholds of M2BPGi associated with HCC,EV,and decomp-ensation in patients with cirrhosis.METHODS This was a prospective study.A total of 153 patients with cirrhosis who met the inclusion criteria were enrolled.The patients were diagnosed with HCC and EV according to the Baveno VII and European Association for the Study of the Liver guidelines.Baseline serum M2BPGi levels were assessed along with other routine tests.The data analysis aimed to determine the cutoff values of M2BPGi for pre-dicting EV and HCC.RESULTS In the study 85.6%of patients were Child-Pugh B and C.M2BPGi mean cutoff index was 7.1±3.7,showing no significant etiological differences.However,M2BPGi levels varied significantly among Child-Pugh classes,EV classifications,and between patients with and without HCC(P<0.01).M2BPGi cutoff values for predicting HCC,EV,and decompensated cirrhosis were 6.50,6.64,and 5.25,respectively.Mul-tivariate analysis confirmed M2BPGi as an independent risk factor for EV[adjusted odds ratio(aOR):1.3,95%CI:1.08-1.64]and liver decompensation(aOR:2.11,95%CI:1.37-3.83).Area under the curve of M2BPGi for HCC differ-entiation was 0.71.An algorithm combining alpha-fetoprotein(AFP)and M2BPGi detected 26 of 28 HCC cases with 98.04%accuracy vs 10 cases by AFP alone.CONCLUSION Serum M2BPGi predicted cirrhosis complications,including decompensation and varices,especially in HCC.Combined with AFP,it enhanced HCC detection.Future liver biopsy studies are needed for tissue confirmation.展开更多
BACKGROUND Mac-2 binding protein glycosylation isomer(M2BPGi)serves as a marker of activated hepatic stellate cells and as such holds potential as a biomarker for liver fibrosis.In Viet Nam,metabolic dysfunction-assoc...BACKGROUND Mac-2 binding protein glycosylation isomer(M2BPGi)serves as a marker of activated hepatic stellate cells and as such holds potential as a biomarker for liver fibrosis.In Viet Nam,metabolic dysfunction-associated steatotic liver disease(MASLD)is rising in prevalence and there is an urgent need for better clinical management,particularly in early detection methods that will improve overall prognosis.AIM To examine M2BPGi cut-off values for staging liver fibrosis in patients with MASLD and risk factors associated with disease progression.METHODS A total of 301 individuals with ultrasound-confirmed or FibroScan-confirmed diagnosis of fatty liver were enrolled in the study.The participants were stratified according to fibrosis stage,measured via magnetic resonance elastography.M2-BPGi,Fibrosis-4(FIB-4)Index score,and routine parameters of liver function were assessed to statistically investigate the correlation of M2BPGi levels in various fibrosis stages and to identify risk factors associated with fibrosis severity.RESULTS M2BPGi levels positively correlated with fibrosis stages,with cut-off indexes of 0.57 for F0-1,0.68 for F2-3,and 0.78 for F4.M2BPGi levels in the F0-1 group were significantly different from those in both the F2-3 group(P=0.038)and the F4 group(P=0.0051);the F2-3 and F4 groups did not show a significant difference(P=0.39).Females exhibited significantly higher M2BPGi levels than males for all fibrosis stages,particularly in the F2-3 group(P=0.01)and F4 group(P=0.0006).In the F4(cirrhosis)group,individuals with diabetes had significantly higher M2BPGi levels than those without.M2BPGi,hemoglobin A1c,and FIB-4 score were identified as independent risk factors for greater fibrosis and cirrhosis.CONCLUSION M2BPGi levels varied significantly throughout fibrosis progression,from early MASLD to cirrhosis,with sex correlation.M2BPGi holds promise as an early biomarker for fibrosis characterization in MASLD adult patient populations.展开更多
Organic additives with multiple functional groups have shown great promise in improving the performance and stability of perovskite solar cells.The functional groups can passivate undercoordinated ions to reduce nonra...Organic additives with multiple functional groups have shown great promise in improving the performance and stability of perovskite solar cells.The functional groups can passivate undercoordinated ions to reduce nonradiative recombination losses.However,how these groups synergistically affect the enhancement beyond passivation is still unclear.Specifically,isomeric molecules with different substitution patterns or molecular shapes remain elusive in designing new organic additives.Here,we report two isomeric carbazolyl bisphosphonate additives,2,7-Cz BP and 3,6-Cz BP.The isomerism effect on passivation and charge transport process was studied.The two molecules have similar passivation effects through multiple interactions,e.g.,P=O···Pb,P=O···H–N and N–H···I.2,7-CzBP can further bridge the perovskite crystallites to facilitates charge transport.Power conversion efficiencies(PCEs)of 25.88%and 21.04%were achieved for 0.09 cm^(2)devices and 14 cm^(2)modules after 2,7-Cz BP treatment,respectively.The devices exhibited enhanced operational stability maintaining 95%of initial PCE after 1000 h of continuous maximum power point tracking.This study of isomerism effect hints at the importance of tuning substitution positions and molecular shapes for organic additives,which paves the way for innovation of next-generation multifunctional aromatic additives.展开更多
The fragile nature of the solid electrolyte interphase(SEI)formed on lithium metal anodes,particularly due to irregular lithium deposition and sluggish ion transport,presents a major challenge to the wider deployment ...The fragile nature of the solid electrolyte interphase(SEI)formed on lithium metal anodes,particularly due to irregular lithium deposition and sluggish ion transport,presents a major challenge to the wider deployment of lithium-sulfur(Li-S)batteries.In this study,a high halogen-containing SEI of the lithium anode was prepared and finely tuned using the variance in chlorine substitution sites as a regulatory mechanism with the positional isomerism of dichloropyridines(DCPs).Remarkably,a highly halogenated inorganic layer was composed predominantly of LiF and LiCl,reaching up to 62%coverage,which not only mitigated lithium dendrite proliferation and accommodated volume changes during cycling but also facilitated efficient Li^(+)ion conduction.Under demanding conditions with a high sulfur loading of 3.0 mg cm^(-2)and a lean electrolyte ratio(electrolyte to sulfur ratio=13.3μL mg^(-1)),the cells retained a capacity of 520.65 mA h g^(-1)after 300 cycles at 0.5 C.展开更多
In recent years,the ternary strategy of adding a vip molecule to the active layer has been proven to be effective for improving the performance of organic solar cells(OSCs).Isomerization engineering of the vip mol...In recent years,the ternary strategy of adding a vip molecule to the active layer has been proven to be effective for improving the performance of organic solar cells(OSCs).Isomerization engineering of the vip molecule is a simple method to increase the amount of promising material,but there are only limited reports,and the structure-property relationships are still unclear.In this work,we synthesized three isomers named BTA5-F-o,BTA5-F-m,and BTA5-F-p,with different fluorine substitution positions,to study the influence of isomerization on the photovoltaic performance.After introducing them as the third components to the classic host system PM6:Y6,all three ternary devices showed improved power conversion efficiency(PCEs)compared to the binary system(PCE of 17.46%).The ternary OSCs based on BTA5-F-o achieved a champion PCE of 19.11%,while BTA5-F-m and BTA5-F-p realized PCEs of 18.65%and 18.45%,respectively.Mechanism studies have shown that the dipole moment of the BTA5-F-o end group is closer to that of the Y6 end group,despite the three isomers with almost identical energy levels and optical properties.It is indicated that the electron attraction ability of BTA5-F-o best matches that of Y6,which leads to the higher charge mobility,less charge recombination,and stronger exciton dissociation and extraction ability in the ternary blend system.This study suggests that rationally adjusting the position of substituents in the terminal group can be an effective way to construct nonfullerene vip acceptors to achieve highly efficient ternary OSCs.展开更多
As more and more studies have shown that lipid molecules play an important role in the whole biology,in-depth analysis of lipid structure has become particularly important in lipidomics.Mass spectrometry(MS),as the pr...As more and more studies have shown that lipid molecules play an important role in the whole biology,in-depth analysis of lipid structure has become particularly important in lipidomics.Mass spectrometry(MS),as the preferred tool for lipid analysis,has greatly promoted the development of this field.However,the existing MS methods still face many difficulties in the in-depth or even comprehensive analysis of lipid structure.In this review,we discuss recent advances in MS methods based on double bond-specific chemistries for the resolving of C=C location and geometry isomers of lipids.This progress has greatly advanced the lipidomics analysis to a deeper structural level and facilitated the development of structural lipid biology.展开更多
This study explores the phenomenon of shape coexistence in nuclei around^(172)Hg,with a focus on the isotopes^(170)Pt,^(172)Hg,and^(174)Pb,as well as the^(170)Pt to^(180)Pt isotopic chain.Utilizing a macro-microscopic...This study explores the phenomenon of shape coexistence in nuclei around^(172)Hg,with a focus on the isotopes^(170)Pt,^(172)Hg,and^(174)Pb,as well as the^(170)Pt to^(180)Pt isotopic chain.Utilizing a macro-microscopic approach that incorporates the Lublin-Strasbourg Drop model combined with a Yukawa-Folded potential and pairing corrections,we analyze the potential energy surfaces(PESs)to understand the impact of pairing interaction.For^(170)Pt,the PES exhibited a prolate ground state,with additional triaxial and oblate-shaped isomers.In^(172)Hg,the ground-state deformation transitions from triaxial to oblate with increasing pairing interaction,demonstrating its nearlyγ-unstable nature.Three shape isomers(prolate,triaxial,and oblate)were observed,with increased pairing strength leading to the disappearance of the triaxial isomer.^(174)Pb exhibited a prolate ground state that became increasingly spherical with stronger pairing.While shape isomers were present at lower pairing strengths,robust shape coexistence was not observed.For realistic pairing interaction,the ground-state shapes transitioned from prolate in^(170)Pt to a coexistence ofγ-unstable and oblate shapes in^(172)Hg,ultimately approaching spherical symmetry in^(174)Pb.A comparison between Exact and Bardeen-Cooper-Schrieffer(BCS)pairing demonstrated that BCS pairing tends to smooth out shape coexistence and reduce the depth of the shape isomer,leading to less pronounced deformation features.The PESs for even-even^(170)-180 Pt isotopes revealed significant shape evolution.^(170)Pt showed a prolate ground state,whereas^(172)Pt exhibited both triaxial and prolate shape coexistence.In^(174)Pt,the ground state was triaxial,coexisted with a prolate minimum.For^(176)Pt,aγ-unstable ground state coexists with a prolate minimum.By 178 Pt and 180Pt,a dominant prolate minimum emerged.These results highlight the role of shape coexistence andγ-instability in the evolution of nuclear structure,especially in the mid-shell region.These findings highlight the importance of pairing interactions in nuclear deformation and shape coexistence,providing insights into the structural evolution of mid-shell nuclei.展开更多
The process of deep hydrodesulfurization(HDS)in gasoline typically results in the saturation of olefins,leading to significant reductions in octane number.In this work,Y-supported Co(Ni)-Mo catalysts that with differe...The process of deep hydrodesulfurization(HDS)in gasoline typically results in the saturation of olefins,leading to significant reductions in octane number.In this work,Y-supported Co(Ni)-Mo catalysts that with different Ni-Co content were prepared by the incipient wetness impregnation method,the structure and properties were characterized and analyzed using HRTEM,XPS,H_(2)-TPR,and NH_(3)-TPD.The isomerization of 1-hexene and 1-octene as well as the HDS of thiophene were studied by using model FCC naphtha.The incorporation of Ni was found to enhance the number of MoS_(2) stacking layers,thereby improving the degree of sulfurization in Mo and subsequently increasing the desulfurization rate,with a maximum achieved desulfurization rate of 94.7%.When employing a Ni/Co ratio of 3:2,optimal synergy between Ni and Co is achieved,resulting in a greater presence of multi-layer stacked II-Co(Ni)MoS active phases.Additionally,appropriate Brønsted acidity levels are maintained to facilitate efficient olefin isomerization while preserving high HDS activity.As a result,the current isomerization yield stands at 58.2%(mass).These understandings shed light on the development of highly HDS and olefin isomerization catalysts.展开更多
[Objective] The relationship between three isomers of microcystins and environmental factors were studied in the fields.[Method] Three isomers of microcystins （MC-LR,RR and YR） from water of five sampling spots in a...[Objective] The relationship between three isomers of microcystins and environmental factors were studied in the fields.[Method] Three isomers of microcystins （MC-LR,RR and YR） from water of five sampling spots in a northern reservoir were observed for one year with High Performance Liquid Chromatography analytical method in order to study the relationship between three isomers and environmental factors.[Result] The three isomers of microcystins showed positive correlation with chlorophyll a;LR and YR isomers all had significant linear positive correlations with the water temperature,but the RR isomer showed no significant correlation with the water temperature;LR and YR isomers had relatively significantly correlativities with the contents of total nitrogen,nitrate nitrogen and organic nitrogen,while the RR isomer only showed a significant negative correlation with the content of nitrate nitrogen;LR and RR isomers both showed significant positive correlations with the contents of total phosphorus and organic phosphorus,while the phosphorus hardly affected the YR isomer and showed no evident correlation.[Conclusion] The relationship between three isomers of microcystins and environmental factors such as chlorophyll a,water temperature,nitrogen,phosphorus were studied and investigated the reasons,which might offered a reference for controlling the growth of blue algae in water and toxin synthesis.展开更多
基金Bureau of Science and Information of Guangzhou under grant 2024A04J3254the National Key Research and Development Program of China under grant 2024YFE0214900+2 种基金the National Natural Science Foundation of China under grant 32272341,he National Key Research and Development Program of China under grant 2023YFD2100401the Opening Project of Hubei Key Laboratory of Lipid Chemistry and Nutrition under grant 202401,are gratefully acknowledged.
文摘Diacylglycerol(DAG)is a functional oil that can reduce body fat accumulation and postprandial triglycerides.In this study,lipase-catalyzed esterification of oleic acid with glycerol was investigated to elucidate the kinetics and selectivity of each reaction step.1H NMR monitoring revealed equilibrated positional isomerization among acylglycerols:sn-1 monoolein comprised 97.3%of total monoacylglycerols,and sn-1,3 diolein comprised 73.3%of total diacylglycerols.Acyl migration(isomer equilibration)occurred faster than overall esterification.The observed rate constants for successive esterification steps(glycerol→monoacylglycerol,monoacylglycerol→diacylglycerol,diacylglycerol→triacylglycerol)were 0.01068,0.00615,and 0.00304 min^(-1),respectively,indicating progressively slower reaction rates for larger acylglycerol species.Furthermore,molecular distillation at 200–220℃ purified the DAG without altering its fatty acid profile.These findings establish a kinetic model of the three-step esterification and highlight the importance of acyl migration in enzymatic DAG synthesis.
基金supported by National Natural Science Foundation of China(22478265)Sichuan Science and Technology Program(2024NSFSC0222)the Fundamental Research Funds for the Central Universities.We are thankful to Hui Wang at the Analytical&Testing Center,Sichuan University,for assisting with SEM characterization.We appreciate Dr.Xiu He and Dr.Ying Song from the College of Biomass Science and Engineering of Sichuan University for helping with experimental.
文摘The agglomeration-prone properties of metal oxide catalysts limit their catalytic efficiency in the isomerization of glucose to fructose.Herein,the hierarchical structure and abundant coordination groups of collagen fibers were used to anchor Zr^(4+),and a highly dispersed ZrO_(2)-nitrogen-doped carbon(ZrO_(2)-NC)composite catalyst was subsequently fabricated by calcination.For the catalytic glucose-to-fructose isomerization over ZrO_(2)-NC,fructose was obtained in 41.3%yield and 85.3%selectivity in a water-acetone solvent at 120℃ for 10 min.The electron-deficient environment of ZrO_(2)surface during charge transfer from ZrO_(2)-to-NC layer facilitated the preferential adsorption of glucose,which accelerated glucose isomerization and fructose desorption.The amphoteric catalyst triggered both proton transfer on the Bronsted base sites and the intramolecular hydride shift of glucose on the Lewis acid sites of ZrO_(2)-NC in the mixed solvent.The latter isomerization mechanism depended on the presence of acetone,which lowered the energy barrier and increased fructose yield.
基金supported by the National Key Research and Development Program of China(No.2022YFC2403500)the National Natural Science Foundation of China(No.22225401)+1 种基金the Science and Technology Innovation Program of Hunan Province(No.2020RC4017)the Guizhou Provincial Science and Technology Projects(No.ZK[2023]293).
文摘Simultaneous identification and quantitative detection of phenylenediamine(PDA)isomers,including o-phenylenediamine(OPD),m-phenylenediamine(MPD),and p-phenylenediamine(PPD),are essential for environmental risk assessment and human health protection.However,current visual detection methods can only distinguish individual PDA isomers and failed to identify binary or ternary mixtures.Herein,a highly active and ultrastable peroxidase(POD)-like CoPt graphitic nanozyme was used for naked-eye identification and colorimetric/fluorescent(FL)dual-mode quantitative detection of PDA isomers.The CoPt@G nanozyme effectively catalyzed the oxidation of OPD,MPD,PPD,OPD+PPD,OPD+MPD,MPD+PPD and OPD+MPD+PPD into yellow,colorless,lilac,yellow,yellow,wine red and reddish-brown products,respectively,in the presence of H_(2)O_(2).Thus,the MPD,PPD,MPD+PPD and OPD+MPD+PPD were easily identified based on the distinct color of their oxidation products,and the OPD,OPD+PPD,OPD+MPD could be further identified by the additional addition of MPD or PPD.Subsequently,CoPt@G/H_(2)O_(2)-,a 3,3′,5,5′-tetramethylbenzidine(TMB)/CoPt@G/H_(2)O_(2)-,and MPD/CoPt@G/H_(2)O_(2)-enabled colorimetric/FL dual-mode platforms for the quantitative detection of OPD,MPD and PPD were proposed.The experimental results illustrated that the constructed sensing platforms exhibit satisfactory sensitivity,comparable to that reported in previous studies.Finally,the evaluation of PDAs in water samples was realized,yielding satisfactory recoveries.This work expanded the application prospects of nanozymes in assessing environmental risks and protection of human security.
基金supported by the National Key R&D Program of China under Grant Nos.2024YFA1610900 and 2023YFA1606401the National Natural Science Foundation of China under Grant Nos.12335007 and 12035001。
文摘The study of nuclear isomers can deepen our understanding of nuclear structure and astrophysics.In this work,we have performed the ab initio calculations of isomers in the N=49 isotones.With a chiral two-plus three-nucleon force,the valence-space effective Hamiltonian was derived using the ab initio many-body perturbation theory named Q-box folded diagrams.The effective operators of electromagnetic operators andβ-decay were obtained using ■-box folded diagrams.With the effective Hamiltonian and operators,we studied the properties of the isomers,gaining a microscopic understanding of the single-particle behaviour of the isomers which we are interested in,showing the reliability of the ab initio calculations.
基金supported by Youth Talent Project of Scientific Research Program of Hubei Provincial Department of Education under Grant Q20241809Doctoral Scientific Research Foundation of Hubei University of Automotive Technology under Grant 202404.
文摘As Internet of Things(IoT)applications expand,Mobile Edge Computing(MEC)has emerged as a promising architecture to overcome the real-time processing limitations of mobile devices.Edge-side computation offloading plays a pivotal role in MEC performance but remains challenging due to complex task topologies,conflicting objectives,and limited resources.This paper addresses high-dimensional multi-objective offloading for serial heterogeneous tasks in MEC.We jointly consider task heterogeneity,high-dimensional objectives,and flexible resource scheduling,modeling the problem as a Many-objective optimization.To solve it,we propose a flexible framework integrating an improved cooperative co-evolutionary algorithm based on decomposition(MOCC/D)and a flexible scheduling strategy.Experimental results on benchmark functions and simulation scenarios show that the proposed method outperforms existing approaches in both convergence and solution quality.
基金supported by the National Natural Science Foundation of China(No.62371263)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCK25_1995).
文摘1 Introduction Recently,the increasing demand for advanced telecommunication systems has spurred extensive research into bandpass filters(BPFs),with particular emphasis on miniaturization,reduction of insertion loss(IL),and enhancement of upper stopband rejection(Huang et al.,2021;Snyder et al.,2021;Lin et al.,2023;Zeng et al.,2023).
基金financially supported by the National Natural Science Foundation of China(No.21172269)the Fundamental Research Funds for the Central Universities,SouthCentral Minzu University(No.CZH24005)。
文摘Binuclear complexes have attracted extensive attention in fields such as catalysis because of their likely bimetallic synergistic effect;however,the mechanism and factors influencing this synergism remain unclear.In this work,six bis-β-ketoimine binuclear titanium complexes4a-4f containing different alkylthio sidearms and configurations were synthesized and characterized by nuclear magnetic resonance hydrogen spectrum(~1H-NMR),nuclear magnetic resonance carbon spectrum(^(13)C-NMR),Fourier transform infrared spectrum(FTIR),and elemental analysis.The intermetallic distances of isomeric complexes 4a,4d,4e and 4f determined through density functional theory(DFT)optimization were in the order 4a<4d<4e<4f and were found to significantly influence the catalytic performance for ethylene(co)polymerization.These complexes could efficiently catalyze ethylene polymerization and ethylene/1-hexene or ethylene/1-octene copolymerization with high activity to produce highmolecular-weight ethylene homo-and co-polymers.Among the three binuclear titanium complexes 4a-4c with similar structures but different lengths of alkylthio sidearms,complex 4a,which contained the shortest methylthio sidearm,exhibited the highest activity for ethylene polymerization and copolymerization with 1-hexene or 1-octene.Additionally,for ethylene/1-hexene or ethylene/1-octene copolymerization,it showed the highest comonomer incorporation compared with propylthio(4b)and octylthio(4c)derivatives because of the smaller steric hindrance of the methyl group in 4a and the more open coordination space for vinyl monomers.Furthermore,among the isomeric complexes 4a,4d,4e and4f,complex 4a with the shortest bimetallic distance also exhibited the highest activity towards ethylene(co)polymerization,and the highest 1-hexene or 1-octene incorporation in comparison with its regioisomeric counterparts 4d,4e and p-phenyl-bridged analog 4f,owing to a more appropriate bimetallic distance that is conducive to a synergistic effect.
文摘Six coordination polymers based on 9,10-di(pyridine-4-yl)-anthracene(DPA)and 1,6-di(1H-imidazol-1-yl)pyrene(DIP)were obtained by solvothermal reactions.{[Zn(DPA)Cl_(2)]·DMF·2H_(2)O}n(1)and{[Zn_(1.5)(DPA)_(1.5)Cl_(3)]·5H_(2)O}n(2)are framework isomers,which both contain zigzag chains formed by DPA,Zn^(2+),and Cl-.The zigzag chains in 1 are further assembled by C—H…Cl interactions into layers,and these layers exhibit two different orientations,displaying a rare 2D to 3D interpenetration mode.The zigzag chains in 2 are parallelly arranged.{[Zn_(3)(DPA)_(3)Br_(6)]·2DMF·_(1.5)H_(2)O}n(3)is isostructural to 2.3 was obtained using ZnBr_(2)instead of ZnCl_(2).[M(DPA)(formate)_(2)(H_(2)O)_(2)]n[M=Co(4),Cu(5)]are isostructural,contain chain structures formed by DPA,Cu^(2+)/Co^(2+),and for-mate ions,which were formed in situ in the solvothermal reaction.{[Zn(DIP)_(2)Cl]ClO_(4)}n(6)contains a layer structure formed by DIP and Zn^(2+).Free DPA and DIP ligands exhibited high fluorescence at room temperature,and coordina-tion polymers 3 and 6 displayed enhanced fluorescent emissions.
基金supported by the National Natural Science Foundation of China(22278419)the Key Core Technology Research(Social Development)Foundation of Suzhou(2023ss06)the Suzhou National Joint Laboratory for Green and Low-carbon Wastewater Treatment and Resource Utilization Technology,Suzhou University of Science and Technology(SZLSDT202404).
文摘Fully utilizing renewable biomass energy is important for saving energy,reducing carbon emissions,and mitigating climate change.As the main hydrolysate of cellulose,a primary component of lignocellulose,glucose could be employed as a starting material to prepare some other functional derivatives for improving the value of biomass resources.The isomerization of glucose to produce fructose is an important intermediate process during numerous high-value-added chemical preparations.Therefore,the development of efficient and selective catalysts for glucose isomerization is of great significance.Currently,glucose isomerase catalysts are limited by the harsh conditions required for microbial activity,which restricts further improvements in fructose yield.Additionally,heterogeneous Bronsted-base and Lewis-acid catalysts commonly employed in chemical isomerization methods often lead to the formation of undesirable by-products,resulting in reduced selectivity toward fructose.This study has demonstrated that lithium-loaded heterogeneous catalysts possess excellent isomerization capabilities under mild conditions.A highly efficient Li-C_(3)N_(4) catalyst was developed,achieving a fructose selectivity of 99.9% and a yield of 42.6% at 60℃ within 1.0 h-comparable to the performance of the enzymatic method.Characterization using X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),proton nuclear magnetic resonance(^(1)H NMR),and inductively coupled plasma(ICP)analyses confirmed that lithium was stably incorporated into the g-C_(3)N_(4) framework through the formation of Li-N bonds.Further investigations using CO_(2) temperature-programmed desorption(CO_(2)-TPD),in situ Fourier-transform infrared spectroscopy(FT-IR)and 7Li magic angle spinning nuclear magnetic resonance(^(7)Li MAS NMR)indicated that the isomerization proceeded via a base-catalyzed mechanism.The Li species were found to interact with hydroxyl groups generated through hydrolysis and simultaneously coordinated with nitrogen atoms in the C_(3)N_(4) matrix,resulting in the formation of Li-N_(6)-H_(2)O active sites.These active sites facilitated the deprotonation of glucose to form an enolate intermediate,followed by a proton transfer step that generated fructose.This mechanism not only improved the efficiency of fructose production but also provided valuable insight into the catalytic role of lithium within the isomerization process.
基金financially supported by the National Natural Science Foundation of China(No.22303033)the Fundamental Research Funds for the Central Universities,China(No.JUSRP123017)+1 种基金Wuxi“Taihu Light”Science and Technology Project-Basic Research(No.K20231063)the Research Matching Grant Scheme at CUHK(No.8601309)。
文摘In this study,a pair of dicarboxylic acids as cis-trans isomerism—citraconic acid(CA)and mesaconic acid(MA),was incorporated into polymeric networks of poly(N-isopropylacrylamide)(PNIPAM)-based core-shell microgels via semi-batch precipitation polymerization.We demonstrated that the pH-temperature dual responsiveness of the core-shell microgels is highly correlated with the structure and position of the acid isomers.Both the cis-trans molecular structure and the crosslinking position of the dicarboxylic acids significantly influenced the hydration capacity and surface charge density of the core-shell microgels.These diverse properties first influenced the swelling behavior,further affecting the interfacial behavior of the microgels,including the oil-water dynamic interfacial tension and air-water compression isotherms.Furthermore,the rheological behavior of the microgel suspensions also displayed distinct dependences on the frequency and temperature,illustrating that the cis-trans molecular structure and crosslinked position of the dicarboxylic acids also significantly influenced the interparticle clustering in the bulk solution.Our results suggest that the pH sensitivity of the cis-trans dicarboxylic acid isomer affects the ionization and surface charge distribution of the core or shell layers of individual microgels,which further determines the interparticle interaction and cooperative rearrangement at interfaces and in the bulk.
基金supported by the Extreme Light Infrastructure Nuclear Physics(ELI-NP)Phase Ⅱ,a project co-financed by the Romanian Government and the European Union through the European Regional Development Fund—the Competitiveness Operational Programme(1/07.07.2016,COP,ID 1334)the Romanian Ministry of Research and Innovation:PN23210105(Phase 2,the Program Nucleu),ELI-RO grants Proiectul ELI-RO/RDI_2024_AMAP,ELI-RO_RDI_2024_LaLuThe,ELIRO_RDI_2024_SPARC+4 种基金ELI10/01.10.2020 of the Romanian Governmentthe European Union,the Romanian Governmentthe Health Program,within the project“Medical Applications of High-Power Lasers—Dr.LASER”SMIS Code:326475the IOSIN funds for research infrastructures of national interest.
文摘We propose a novel scheme for the population and depletion of nuclear isomers.This scheme combines the γ photons with energiesà 10 keV emitted during the interaction of a contemporary high-intensity laser pulse with a plasma and one or multiple photon beams supplied by intense lasers.Owing to nonlinear effects,two-or multiphoton absorption dominates over the conventional multistep one-photon process for an optimized γ flash.Moreover,this nonlinear effect can be greatly enhanced with the help of externally supplied low-energy photons coming from another laser.These low-energy photons act such that the effective cross-section experienced by the γ photons becomes tunable,growing with the intensity I_(0) of the beam.Assuming I_(0)~10^(18) W·cm^(-2) for the photon beam,an effective cross-section as large as 10^(-21)-10^(-28) cm^(2) for the γ photons can be achieved.Thus,with state-of-the-art 10 PW laser facilities,the yields from two-photon absorption can reach 10^(6)-10^(9) isomers per shot for selected states that are separated from their ground state by E2 transitions.Similar yields for transitions with higher multipolarities can be accommodated by multiphoton absorption with additional photons provided.
文摘BACKGROUND Cirrhosis is a progressive condition characterized by fibrosis that can lead to severe complications and increased mortality.The mac-2 binding protein glyco-sylation isomer(M2BPGi)is a prominent biomarker for predicting hepatocellular carcinoma(HCC)and cirrhosis-induced esophageal varices(EV).AIM To investigate thresholds of M2BPGi associated with HCC,EV,and decomp-ensation in patients with cirrhosis.METHODS This was a prospective study.A total of 153 patients with cirrhosis who met the inclusion criteria were enrolled.The patients were diagnosed with HCC and EV according to the Baveno VII and European Association for the Study of the Liver guidelines.Baseline serum M2BPGi levels were assessed along with other routine tests.The data analysis aimed to determine the cutoff values of M2BPGi for pre-dicting EV and HCC.RESULTS In the study 85.6%of patients were Child-Pugh B and C.M2BPGi mean cutoff index was 7.1±3.7,showing no significant etiological differences.However,M2BPGi levels varied significantly among Child-Pugh classes,EV classifications,and between patients with and without HCC(P<0.01).M2BPGi cutoff values for predicting HCC,EV,and decompensated cirrhosis were 6.50,6.64,and 5.25,respectively.Mul-tivariate analysis confirmed M2BPGi as an independent risk factor for EV[adjusted odds ratio(aOR):1.3,95%CI:1.08-1.64]and liver decompensation(aOR:2.11,95%CI:1.37-3.83).Area under the curve of M2BPGi for HCC differ-entiation was 0.71.An algorithm combining alpha-fetoprotein(AFP)and M2BPGi detected 26 of 28 HCC cases with 98.04%accuracy vs 10 cases by AFP alone.CONCLUSION Serum M2BPGi predicted cirrhosis complications,including decompensation and varices,especially in HCC.Combined with AFP,it enhanced HCC detection.Future liver biopsy studies are needed for tissue confirmation.
文摘BACKGROUND Mac-2 binding protein glycosylation isomer(M2BPGi)serves as a marker of activated hepatic stellate cells and as such holds potential as a biomarker for liver fibrosis.In Viet Nam,metabolic dysfunction-associated steatotic liver disease(MASLD)is rising in prevalence and there is an urgent need for better clinical management,particularly in early detection methods that will improve overall prognosis.AIM To examine M2BPGi cut-off values for staging liver fibrosis in patients with MASLD and risk factors associated with disease progression.METHODS A total of 301 individuals with ultrasound-confirmed or FibroScan-confirmed diagnosis of fatty liver were enrolled in the study.The participants were stratified according to fibrosis stage,measured via magnetic resonance elastography.M2-BPGi,Fibrosis-4(FIB-4)Index score,and routine parameters of liver function were assessed to statistically investigate the correlation of M2BPGi levels in various fibrosis stages and to identify risk factors associated with fibrosis severity.RESULTS M2BPGi levels positively correlated with fibrosis stages,with cut-off indexes of 0.57 for F0-1,0.68 for F2-3,and 0.78 for F4.M2BPGi levels in the F0-1 group were significantly different from those in both the F2-3 group(P=0.038)and the F4 group(P=0.0051);the F2-3 and F4 groups did not show a significant difference(P=0.39).Females exhibited significantly higher M2BPGi levels than males for all fibrosis stages,particularly in the F2-3 group(P=0.01)and F4 group(P=0.0006).In the F4(cirrhosis)group,individuals with diabetes had significantly higher M2BPGi levels than those without.M2BPGi,hemoglobin A1c,and FIB-4 score were identified as independent risk factors for greater fibrosis and cirrhosis.CONCLUSION M2BPGi levels varied significantly throughout fibrosis progression,from early MASLD to cirrhosis,with sex correlation.M2BPGi holds promise as an early biomarker for fibrosis characterization in MASLD adult patient populations.
基金financially supported by the National Science Foundation of China(62474142)Natural Science Foundation of Shandong Province(No.ZR2024YQ070)。
文摘Organic additives with multiple functional groups have shown great promise in improving the performance and stability of perovskite solar cells.The functional groups can passivate undercoordinated ions to reduce nonradiative recombination losses.However,how these groups synergistically affect the enhancement beyond passivation is still unclear.Specifically,isomeric molecules with different substitution patterns or molecular shapes remain elusive in designing new organic additives.Here,we report two isomeric carbazolyl bisphosphonate additives,2,7-Cz BP and 3,6-Cz BP.The isomerism effect on passivation and charge transport process was studied.The two molecules have similar passivation effects through multiple interactions,e.g.,P=O···Pb,P=O···H–N and N–H···I.2,7-CzBP can further bridge the perovskite crystallites to facilitates charge transport.Power conversion efficiencies(PCEs)of 25.88%and 21.04%were achieved for 0.09 cm^(2)devices and 14 cm^(2)modules after 2,7-Cz BP treatment,respectively.The devices exhibited enhanced operational stability maintaining 95%of initial PCE after 1000 h of continuous maximum power point tracking.This study of isomerism effect hints at the importance of tuning substitution positions and molecular shapes for organic additives,which paves the way for innovation of next-generation multifunctional aromatic additives.
基金the Natural Science Foundation of Shandong Province of China for the research grant number ZR2022MB118。
文摘The fragile nature of the solid electrolyte interphase(SEI)formed on lithium metal anodes,particularly due to irregular lithium deposition and sluggish ion transport,presents a major challenge to the wider deployment of lithium-sulfur(Li-S)batteries.In this study,a high halogen-containing SEI of the lithium anode was prepared and finely tuned using the variance in chlorine substitution sites as a regulatory mechanism with the positional isomerism of dichloropyridines(DCPs).Remarkably,a highly halogenated inorganic layer was composed predominantly of LiF and LiCl,reaching up to 62%coverage,which not only mitigated lithium dendrite proliferation and accommodated volume changes during cycling but also facilitated efficient Li^(+)ion conduction.Under demanding conditions with a high sulfur loading of 3.0 mg cm^(-2)and a lean electrolyte ratio(electrolyte to sulfur ratio=13.3μL mg^(-1)),the cells retained a capacity of 520.65 mA h g^(-1)after 300 cycles at 0.5 C.
基金support from the National Natural Science Foundation of China(62204146,52303259)the Start-up Grant of Henan University of Technology(2023BS035)。
文摘In recent years,the ternary strategy of adding a vip molecule to the active layer has been proven to be effective for improving the performance of organic solar cells(OSCs).Isomerization engineering of the vip molecule is a simple method to increase the amount of promising material,but there are only limited reports,and the structure-property relationships are still unclear.In this work,we synthesized three isomers named BTA5-F-o,BTA5-F-m,and BTA5-F-p,with different fluorine substitution positions,to study the influence of isomerization on the photovoltaic performance.After introducing them as the third components to the classic host system PM6:Y6,all three ternary devices showed improved power conversion efficiency(PCEs)compared to the binary system(PCE of 17.46%).The ternary OSCs based on BTA5-F-o achieved a champion PCE of 19.11%,while BTA5-F-m and BTA5-F-p realized PCEs of 18.65%and 18.45%,respectively.Mechanism studies have shown that the dipole moment of the BTA5-F-o end group is closer to that of the Y6 end group,despite the three isomers with almost identical energy levels and optical properties.It is indicated that the electron attraction ability of BTA5-F-o best matches that of Y6,which leads to the higher charge mobility,less charge recombination,and stronger exciton dissociation and extraction ability in the ternary blend system.This study suggests that rationally adjusting the position of substituents in the terminal group can be an effective way to construct nonfullerene vip acceptors to achieve highly efficient ternary OSCs.
基金financially supported by the National Natural Science Foundation of China(No.22074111)National Key Research and Development Program of China(No.2021YFC2700700)the Opening fund of Hubei Key Laboratory of Bioinorganic Chemistry&Materia Medica(No.BCMM202303)。
文摘As more and more studies have shown that lipid molecules play an important role in the whole biology,in-depth analysis of lipid structure has become particularly important in lipidomics.Mass spectrometry(MS),as the preferred tool for lipid analysis,has greatly promoted the development of this field.However,the existing MS methods still face many difficulties in the in-depth or even comprehensive analysis of lipid structure.In this review,we discuss recent advances in MS methods based on double bond-specific chemistries for the resolving of C=C location and geometry isomers of lipids.This progress has greatly advanced the lipidomics analysis to a deeper structural level and facilitated the development of structural lipid biology.
基金supported by the National Natural Science Foundation of China(Nos.12275115 and 12175097)the National Science Centre of Poland(No.2023/49/B/ST2/01294).
文摘This study explores the phenomenon of shape coexistence in nuclei around^(172)Hg,with a focus on the isotopes^(170)Pt,^(172)Hg,and^(174)Pb,as well as the^(170)Pt to^(180)Pt isotopic chain.Utilizing a macro-microscopic approach that incorporates the Lublin-Strasbourg Drop model combined with a Yukawa-Folded potential and pairing corrections,we analyze the potential energy surfaces(PESs)to understand the impact of pairing interaction.For^(170)Pt,the PES exhibited a prolate ground state,with additional triaxial and oblate-shaped isomers.In^(172)Hg,the ground-state deformation transitions from triaxial to oblate with increasing pairing interaction,demonstrating its nearlyγ-unstable nature.Three shape isomers(prolate,triaxial,and oblate)were observed,with increased pairing strength leading to the disappearance of the triaxial isomer.^(174)Pb exhibited a prolate ground state that became increasingly spherical with stronger pairing.While shape isomers were present at lower pairing strengths,robust shape coexistence was not observed.For realistic pairing interaction,the ground-state shapes transitioned from prolate in^(170)Pt to a coexistence ofγ-unstable and oblate shapes in^(172)Hg,ultimately approaching spherical symmetry in^(174)Pb.A comparison between Exact and Bardeen-Cooper-Schrieffer(BCS)pairing demonstrated that BCS pairing tends to smooth out shape coexistence and reduce the depth of the shape isomer,leading to less pronounced deformation features.The PESs for even-even^(170)-180 Pt isotopes revealed significant shape evolution.^(170)Pt showed a prolate ground state,whereas^(172)Pt exhibited both triaxial and prolate shape coexistence.In^(174)Pt,the ground state was triaxial,coexisted with a prolate minimum.For^(176)Pt,aγ-unstable ground state coexists with a prolate minimum.By 178 Pt and 180Pt,a dominant prolate minimum emerged.These results highlight the role of shape coexistence andγ-instability in the evolution of nuclear structure,especially in the mid-shell region.These findings highlight the importance of pairing interactions in nuclear deformation and shape coexistence,providing insights into the structural evolution of mid-shell nuclei.
基金supported by the National Natural Science Foundation of China(U22B20140,22021004,22325808,22393950)the National Key Research and Development Program of China(2020YFA0210900).
文摘The process of deep hydrodesulfurization(HDS)in gasoline typically results in the saturation of olefins,leading to significant reductions in octane number.In this work,Y-supported Co(Ni)-Mo catalysts that with different Ni-Co content were prepared by the incipient wetness impregnation method,the structure and properties were characterized and analyzed using HRTEM,XPS,H_(2)-TPR,and NH_(3)-TPD.The isomerization of 1-hexene and 1-octene as well as the HDS of thiophene were studied by using model FCC naphtha.The incorporation of Ni was found to enhance the number of MoS_(2) stacking layers,thereby improving the degree of sulfurization in Mo and subsequently increasing the desulfurization rate,with a maximum achieved desulfurization rate of 94.7%.When employing a Ni/Co ratio of 3:2,optimal synergy between Ni and Co is achieved,resulting in a greater presence of multi-layer stacked II-Co(Ni)MoS active phases.Additionally,appropriate Brønsted acidity levels are maintained to facilitate efficient olefin isomerization while preserving high HDS activity.As a result,the current isomerization yield stands at 58.2%(mass).These understandings shed light on the development of highly HDS and olefin isomerization catalysts.
基金Supported by Technical Innovation Project of Ministry of Water Conservancy(SCX2002-04)National Nature Science Foundation of China(50579015)~~
文摘[Objective] The relationship between three isomers of microcystins and environmental factors were studied in the fields.[Method] Three isomers of microcystins （MC-LR,RR and YR） from water of five sampling spots in a northern reservoir were observed for one year with High Performance Liquid Chromatography analytical method in order to study the relationship between three isomers and environmental factors.[Result] The three isomers of microcystins showed positive correlation with chlorophyll a;LR and YR isomers all had significant linear positive correlations with the water temperature,but the RR isomer showed no significant correlation with the water temperature;LR and YR isomers had relatively significantly correlativities with the contents of total nitrogen,nitrate nitrogen and organic nitrogen,while the RR isomer only showed a significant negative correlation with the content of nitrate nitrogen;LR and RR isomers both showed significant positive correlations with the contents of total phosphorus and organic phosphorus,while the phosphorus hardly affected the YR isomer and showed no evident correlation.[Conclusion] The relationship between three isomers of microcystins and environmental factors such as chlorophyll a,water temperature,nitrogen,phosphorus were studied and investigated the reasons,which might offered a reference for controlling the growth of blue algae in water and toxin synthesis.
