Lithium-ion batteries(LIBs),while dominant in energy storage due to high energy density and cycling stability,suffer from severe capacity decay,rate capability degradation,and lithium dendrite formation under low-temp...Lithium-ion batteries(LIBs),while dominant in energy storage due to high energy density and cycling stability,suffer from severe capacity decay,rate capability degradation,and lithium dendrite formation under low-temperature(LT)operation.Therefore,a more comprehensive and systematic understanding of LIB behavior at LT is urgently required.This review article comprehensively reviews recent advancements in electrolyte engineering strategies aimed at improving the low-temperature operational capabilities of LIBs.The study methodically examines critical performance-limiting mechanisms through fundamental analysis of four primary challenges:insufficient ionic conductivity under cryogenic conditions,kinetically hindered charge transfer processes,Li+transport limitations across the solidelectrolyte interphase(SEI),and uncontrolled lithium dendrite growth.The work elaborates on innovative optimization approaches encompassing lithium salt molecular design with tailored dissociation characteristics,solvent matrix optimization through dielectric constant and viscosity regulation,interfacial engineering additives for constructing low-impedance SEI layers,and gel-polymer composite electrolyte systems.Notably,particular emphasis is placed on emerging machine learning-guided electrolyte formulation strategies that enable high-throughput virtual screening of constituent combinations and prediction of structure-property relationships.These artificial intelligence-assisted rational design frameworks demonstrate significant potential for accelerating the development of next-generation LT electrolytes by establishing quantitative composition-performance correlations through advanced data-driven methodologies.展开更多
This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0...This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.1)Mo_(0.05)O_(3-δ)(B S CNM_(0.05)),Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.05)Mo_(0.1)O_(3-δ)(BSCNM_(0.1)),and Ba_(0.6)Sr_(0.4)Co_(0.85)Mo_(0.15)O_(3-δ)(BSCM)—with Mo doping contents of 5mol%,10mol%,and15mol%,respectively,were successfully prepared using the sol-gel method.The effects of Mo doping on the crystal structure,conductivity,thermal expansion coefficient,oxygen reduction reaction(ORR)activity,and electrochemical performance were systematically evaluated using X-ray diffraction analysis,thermally induced characterization,electrochemical impedance spectroscopy,and single-cell performance tests.The results revealed that Mo doping could improve the conductivity of the materials,suppress their thermal expansion effects,and significantly improve the electrochemical performance.Surface chemical state analysis using X-ray photoelectron spectroscopy revealed that 5mol%Mo doping could facilitate a high adsorbed oxygen concentration leading to enhanced ORR activity in the materials.Density functional theory calculations confirmed that Mo doping promoted the ORR activity in the materials.At an operating temperature of 600℃,the BSCNM_(0.05)cathode material exhibited significantly enhanced electrochemical impedance characteristics,with a reduced area specific resistance of 0.048Ω·cm~2,which was lower than that of the undoped BSCN matrix material by 32.39%.At the same operating temperature,an anode-supported single cell using a BSCNM_(0.05)cathode achieved a peak power density of 1477 mW·cm^(-2),which was 30.71%,56.30%,and 171.50%higher than those of BSCN,BSCNM_(0.1),and B SCM,respectively.The improved ORR activity and electrochemical performance of BSCNM_(0.05)indicate that it can be used as a cathode material in low-temperature solid oxide fuel cells.展开更多
BACKGROUND Postoperative delirium(POD)is a common and serious complication in surgical patients,particularly older adults.Alterations in cholinergic function have been implicated in its pathophysiology.AIM To evaluate...BACKGROUND Postoperative delirium(POD)is a common and serious complication in surgical patients,particularly older adults.Alterations in cholinergic function have been implicated in its pathophysiology.AIM To evaluate the association between preoperative serum cholinesterase(ChE)activity—specifically butyrylcholinesterase(BuChE)and acetylcholinesterase(AChE)—and the risk of POD in adult surgical patients in a meta-analysis.METHODS A systematic search was conducted in PubMed,EMBASE,and Web of Science up to March 28,2025 for studies reporting preoperative serum BuChE or AChE activity in relation to subsequent POD incidence.Standardized mean differences(SMDs)and odds ratios(ORs)with 95%confidence intervals(CIs)were pooled using random-effects models.Subgroup and sensitivity analyses were performed based on follow-up duration and analytic models.RESULTS Thirteen studies(n=2730 patients)were included.Patients who developed POD had significantly lower preoperative BuChE activity than those who did not(SMD=-0.28;95%CI:-0.39 to-0.16;I²=18%).Higher BuChE activity was associated with a reduced risk of POD(OR per 100 unit increment=0.97;95%CI:0.95-0.99;I2=0%).In contrast,pooled AChE activity did not differ significantly between POD and non-POD groups(SMD=-0.25;95%CI:-0.53 to 0.03;P=0.08;I2=80%),and the ORs per 1 unit increment in AChE activity were not statistically significant(OR=0.98;95%CI:0.95-1.01).CONCLUSION Lower preoperative serum BuChE activity is associated with an increased risk of POD in adults undergoing surgery.BuChE activity may serve as a potential preoperative biomarker for POD risk stratification.展开更多
Conductive materials(CM)can improve methane production(MP)efficiency in many methanogenic systems.However,several types of CM exist,and there are uncertainties regarding whether they all improve MP efficiency to the s...Conductive materials(CM)can improve methane production(MP)efficiency in many methanogenic systems.However,several types of CM exist,and there are uncertainties regarding whether they all improve MP efficiency to the same extent and modulate microbial communities in a similar way.To investigate that,different microbial enrichments with and without activated carbon(AC),magnetite(Mag),and zeolites(Zeo)(at 0.5 g/L)were developed.MP profiles and microbial composition changes were compared among enrichments.The behavior of all enrichments was different,although the initial inoculum sludge was the same.Lag phase duration was lower in AC enrichment,while the complete conversion of butyrate to methane was faster in Mag enrichment.Syntrophomonas was the most abundant bacterial genus in all enrichments,but changes in the methanogenic community were evident.Acetoclastic methanogens were more diverse in Mag enrichment,with microorganisms assigned to Methanosarcina and Methanothrix gener1,but Methanothrix was the only acetoclastic methanogen in the other enrichments.On the other hand,different species of hydrogenotrophic methanogens prevailed in distinct enrichments.The metatranscriptomics results revealed that the dominant mechanism of interspecies electron transfer in the AC enrichment utilized hydrogen as the electron carrier,and no evidences of direct interspecies electron transfer(DIET)could be found.These results showed how different CM modulate microbial communities and affect MP efficiency through mechanisms that do not necessarily involve DIET or mediation via CM.展开更多
BACKGROUND Major depressive disorder(MDD)and obesity(OB)are bidirectionally comorbid conditions with common neurobiological underpinnings.However,the neurocognitive mechanisms of their comorbidity remain poorly unders...BACKGROUND Major depressive disorder(MDD)and obesity(OB)are bidirectionally comorbid conditions with common neurobiological underpinnings.However,the neurocognitive mechanisms of their comorbidity remain poorly understood.AIM To examine regional abnormalities in spontaneous brain activity among patients with MDD-OB comorbidity.METHODS This study adopted a regional homogeneity(ReHo)analysis of resting-state functional magnetic resonance imaging.The study included 149 hospital patients divided into four groups:Patients experiencing their first episode of drug-naive MDD with OB,patients with MDD without OB,and age-and sex-matched healthy individuals with and without OB.Whole-brain ReHo analysis was conducted using SPM12 software and RESTplus toolkits,with group comparisons via ANOVA and post-hoc tests.Correlations between ReHo values and behavioral measures were examined.RESULTS ANOVA revealed significant whole-brain ReHo differences among the four groups in four key regions:The left middle temporal gyrus(MTG.L),right cuneus,left precuneus,and left thalamus.Post-hoc analyses confirmed pairwise differences between all groups across these regions(P<0.05).OB was associated with ReHo alterations in the MTG.L,right cuneus,and left thalamus,whereas abnormalities in the precuneus suggested synergistic pathological mechanisms between MDD and OB.Statistically significant correlations were found between the drive and fun-seeking dimensions of the behavioral activation system,as well as behavioral inhibition and the corresponding ReHo values.CONCLUSION Our findings provide novel evidence for the neuroadaptive mechanisms underlying the MDD-OB comorbidity.Further validation could lead to personalized interventions targeting MTG.L hyperactivity and targeting healthy food cues.展开更多
The intrinsic pressure framework,which treats self-propelling force as an external force,provides a convenient and consistent description of mechanical equilibrium in active matter.However,direct experimental evidence...The intrinsic pressure framework,which treats self-propelling force as an external force,provides a convenient and consistent description of mechanical equilibrium in active matter.However,direct experimental evidence is still lacking.To validate this framework,here we employ a programmable robotic platform,where a single light-controlled wheeled robot travels in an activity landscape.Our experiments quantitatively demonstrate that the intrinsic pressure difference across the activity interface is balanced by the emerged polarization force.This result unambiguously confirms the theoretical predictions,thus validating the intrinsic pressure framework and laying the experimental foundation for the intrinsic pressure-based mechanical description of dry active matter.展开更多
Hierarchical Fe-Beta obtained by hydrothermal synthesis exhibited higher low-temperature NH_3-SCR activity than conventional Fe-Beta. In order to identify the main factors leading to the difference in catalytic activi...Hierarchical Fe-Beta obtained by hydrothermal synthesis exhibited higher low-temperature NH_3-SCR activity than conventional Fe-Beta. In order to identify the main factors leading to the difference in catalytic activity, we investigated the pore structure, acidity and Fe sites of the hierarchical Fe-Beta and conventional Fe-Beta. The enhanced activity of hierarchical Fe-Beta was mainly due to the increase of the quantity of active Fe species. NH_3-TPD and DRIFTS results of NH_3 adsorption clearly verified that hierarchical Fe-Beta had more Lewis acid sites, which is beneficial to the adsorption and activation of NH_3. The H_2-TPR, UV–vis DRS, and EPR results confirmed that the hierarchical Fe-Beta had more isolated active Fe species, which may be associated with that the hierarchical structure introduced more structural defects as ion-exchange sites. Based on the analysis of kinetics experiments and the abovementioned characterizations, it can be concluded that the improvement of NH_3-SCR activity was not due to an intrinsic effect of the specific structural characteristics, but was related to more Fe active sites and better dispersion of Fe species in the hierarchical Fe-Beta.展开更多
Active inflammation in“inactive”progressive multiple sclerosis:Traditionally,the distinction between relapsing-remitting multiple sclerosis and progressive multiple sclerosis(PMS)has been framed as an inflammatory v...Active inflammation in“inactive”progressive multiple sclerosis:Traditionally,the distinction between relapsing-remitting multiple sclerosis and progressive multiple sclerosis(PMS)has been framed as an inflammatory versus degenerative dichotomy.This was based on a broad misconception regarding essentially all neurodegenerative conditions,depicting the degenerative process as passive and immune-independent occurring as a late byproduct of active inflammation in the central nervous system(CNS),which is(solely)systemically driven.展开更多
Developing efficient and stable cathodes for low-temperature solid oxide fuel cells(LT-SOFCs) is of great importance for the practical commercialization.Herein,we propose a series of Sm-modified Bi_(0.7-x)Sm_xSr_(0.3)...Developing efficient and stable cathodes for low-temperature solid oxide fuel cells(LT-SOFCs) is of great importance for the practical commercialization.Herein,we propose a series of Sm-modified Bi_(0.7-x)Sm_xSr_(0.3)FeO_(3-δ) perovskites as highly-active catalysts for LT-SOFCs.Sm doping can significantly enhance the electrocata lytic activity and chemical stability of cathode.At 600℃,Bi_(0.675)Sm_(0.025)Sr_(0.3)FeO_(3-δ)(BSSF25) cathode has been found to be the optimum composition with a polarization resistance of 0.098 Ω cm^2,which is only around 22.8% of Bi_(0.7)Sr_(0.3)FeO_(3-δ)(BSF).A full cell utilizing BSSF25 displays an exceptional output density of 790 mW cm^(-2),which can operate continuously over100 h without obvious degradation.The remarkable electrochemical performance observed can be attributed to the improved O_(2) transport kinetics,superior surface oxygen adsorption capacity,as well as O_(2)p band centers in close proximity to the Fermi level.Moreover,larger average bonding energy(ABE) and the presence of highly acidic Bi,Sm,and Fe ions restrict the adsorption of CO_(2) on the cathode surface,resulting in excellent CO_(2) resistivity.This work provides valuable guidance for systematic design of efficient and durable catalysts for LT-SOFCs.展开更多
We extracted marine low-temperature lysozyme (MLTL),a novel lysozyme,from a marine microorganism through fermentation.Our previous study suggested that a low molecular weight (16 kDa) may exert anti-tumor activity thr...We extracted marine low-temperature lysozyme (MLTL),a novel lysozyme,from a marine microorganism through fermentation.Our previous study suggested that a low molecular weight (16 kDa) may exert anti-tumor activity through antiangiogenesis.In this study,we extracted a high weight (39 kDa) and investigated its antiangiogenic activity in vivo and in vitro.Using zebrafish embryos as an in vivo study model,we found that treatment with MLTL significantly inhibited the growth of subintestinal vessels (SIVs) in a dose-dependent manner and that 400 μg/ml MLTL was sufficient to block the growth of SIVs.An in vitro study conducted using human umbilical vein endothelial cells (HUVECs) revealed that MLTL suppressed the proliferation,migration and tube formation of HUVECs in a dose-dependent manner.Interestingly,assays by flow cytometry and DNA electrophoresis indicated that MLTL was able to induce apoptosis of HUVECs.Moreover,further study demonstrated that the disruption of intracellular Ca2+ homeostasis may play an important role in MLTL induced apoptosis of HUVECs.Taken together,the results of this study demonstrate for the first time that MLTL inhibits angiogenesis through its pleiotropic effects on vascular endothelial cells and induces apoptosis through regulation of cellular Ca2+ levels.The results of this study also revealed a possible mechanism underlying the antiangiogenic effect of MLTL and suggested that MLTL may be a promising new antiangiogenic agent for use in cancer therapy.展开更多
A series of TiO_(2)-Al_(2)O_(3) composites with Al/Ti molar ratios of 0.1,0.2,and 0.4 were synthesized by a coprecipitation method and used as supports to prepare supported MnCeO_(x) catalysts by an impregnation metho...A series of TiO_(2)-Al_(2)O_(3) composites with Al/Ti molar ratios of 0.1,0.2,and 0.4 were synthesized by a coprecipitation method and used as supports to prepare supported MnCeO_(x) catalysts by an impregnation method.The physico-chemical properties of the samples were extensively characterized by N_(2) physisorption,X-ray diffraction,Raman spectroscopy,scanning electron micro scopy and energy-dispersive Xray spectroscopy element mapping,X-ray photoelectron spectroscopy,H_(2)-temperature programmed reduction,ammonia temperature programmed desorption,and in-situ diffuse reflectance infrared Fourier transform spectroscopy.The catalytic activity and resistance to water vapor and SO_(2) of the asprepared catalysts for the SCR of NO_(x) with NH_(3) were evaluated at 50-250℃ and GHSV of 80000 mL/(gcat·h).The results reveal that MnCeO_(x)/TiO_(2)-Al_(2)O_(3) exhibits higher activity and better SO_(2) tolerance than MnCeO_(x)/TiO_(2).Combining with the characterization results,the enhanced activity and SO_(2) tolerance of MnCeO_(x)/TiO_(2)-Al_(2)O_(3) can be mainly attributed to higher relative concentrations of Mn4+and chemisorbed oxygen species,stronger reducibility,and larger adsorption capacity for NH_(3) and NO,which originate from the larger specific surface area and pore volume,higher dispersion of Mn and Ce species compared with MnCeO_(x)/TiO_(2).Moreover,in situ DRIFTS was used to investigate the reaction mechanism,and the results indicate that the NH_(3)-SCR reaction over MnCeO_(x)/TiO_(2) and MnCeO_(x)/TiO_(2)-Al_(2)O_(3) takes place by both the E-R and L-H mechanisms.展开更多
A series of CeO_(2)-TiO_(2)mixed oxides supports with various Ce/Ti molar ratio were synthesized by modified coprecipitation method. The corresponding Pt loaded(0.5 wt% Pt) catalysts were prepared by electronless depo...A series of CeO_(2)-TiO_(2)mixed oxides supports with various Ce/Ti molar ratio were synthesized by modified coprecipitation method. The corresponding Pt loaded(0.5 wt% Pt) catalysts were prepared by electronless deposition method and evaluated for the deep oxidation of n-hexane as a model VOCs. The results show that the CeO_(2)and TiOxnanoparticles can highly disperse into each other and form Ce_(2)Ti_(2)O_(7)solid solution with appropriate Ce/Ti molar ratio, which significantly improves their redox ability by enhancing the interaction between CeO_(2)and TiO_(x). The dispersibility of Pt species can also be adjusted by altering the Ce/Ti molar ratio, and Pt/CeTi-2/1 catalyst with Ce/Ti molar ratio of 2:1 exhibits the best Pt dispersibility that Pt species mainly exist as Pt single atoms. The high dispersion of Pt species in the Pt/CeO_(2)-TiO_(2)catalysts would promote the catalytic activity of VOCs oxidation with low T90% values(1000 ppm, GHSV = 15,000 h^(-1)), such as for n-hexane degradation with T90% of 139℃. The characterizations reveal that the superior activity is mainly related to possessing the more Pt2+species,adsorbed oxygen species and higher low-temperature reducibility owing to the strong interaction between highly dispersed Pt species and CeO_(2)-TiO_(2)as well as the promoted migration of lattice oxygen by the formation of more Ce_(2)Ti_(2)O_(7)species. Furthermore, the Pt/CeTi-2/1 catalyst also exhibits excellent stability for chlorinated and other non-chlorinated VOCs oxidation, making it very promising for real application under various operating conditions.展开更多
The distinctive distribution of acoustic emission(AE)characteristic parameters generated during tensile testing of low-temperature tempered AISI 4140 steel was investigated.Two clusters of acoustic emission signals we...The distinctive distribution of acoustic emission(AE)characteristic parameters generated during tensile testing of low-temperature tempered AISI 4140 steel was investigated.Two clusters of acoustic emission signals were distinguished using power-law distribution fitting and k-means clustering methods.These clusters were identified as resulting from dislocation motion during yielding and dislocation entanglement during uniform plastic deformation.The conclusion is further confirmed by transmission electron microscopy images at different strains.In particular,the unique"arch-shaped"distribution of the acoustic emission energy during yielding implies a change in unusual dislocation motion modes.The effect of carbide precipitation was qualitatively discussed as not considering the primary cause of the formation of this arch-shaped distribution.The evolution of dislocation motion modes during yielding of low-temperature tempered martensite was elucidated by comparing the significant difference in cumulative energy values during yielding of annealed and low-temperature tempered specimens.Dislocations emit from Frank–Read or grain boundary sources and slip along short free paths,contributing to the initial increase in AE signals energy.Subsequently,the primary source of acoustic emission energy“arch-shaped”peak during yielding was generated by the avalanche behavior of accumulated dislocations,leading to the accelerated dislocation motion.展开更多
The distributions of framework aluminum(Al)in zeolites critically govern the location and speciation of active copper(Cu)centers,thereby influencing their performance in ammonia selective catalytic reduction(NH_(3)-SC...The distributions of framework aluminum(Al)in zeolites critically govern the location and speciation of active copper(Cu)centers,thereby influencing their performance in ammonia selective catalytic reduction(NH_(3)-SCR)of nitrogen oxides(NO_(x)).Conventional Cu-SSZ-39(Cu-SSZ-39-T)exhibits excellent hydrothermal stability but limited low-temperature activity(150–225℃)due to a low concentration of Al in 8-membered rings(8MRs)that inhibits the formation of active[Cu(OH)]^(+)-Z species.Herein,an SSZ-39 zeolite synthesized with potassium ions(SSZ-39-K)achieved a significantly higher 8MR Al fraction(37.6%).Density functional theory calculations and H_(2)-temperature-programmed reduction analyses confirmed that the increased 8MR Al population facilitated the formation of[Cu(OH)]^(+)-Z species.Aged Cu-SSZ-39-K exhibited nearly twice the NO_(x)conversion of aged Cu-SSZ-39-T in the 150–225℃range while maintaining comparable high-temperature activity(250–550℃)under a gas hourly space velocity of 250,000 h^(-1).Enhanced low-temperature performance is particularly beneficial for mitigating NO_(x)emissions during cold-start phase.Moreover,SSZ-39-K was synthesized with a high crystallization yield(~65%),nearly double the highest yield(33%)reported for direct synthesis routes.This work establishes a robust strategy for tailoring Al distributions in SSZ-39 zeolites,offering an effective pathway to improve low-temperature NH_(3)-SCR performance and promote practical implementation.展开更多
Developing a high-efficiency catalyst with both superior low-temperature activity and good N_(2)selectivity is still challenging for the NH_(3)selective catalytic reduction(SCR)of NO_(x)from mobile sources.Herein,we d...Developing a high-efficiency catalyst with both superior low-temperature activity and good N_(2)selectivity is still challenging for the NH_(3)selective catalytic reduction(SCR)of NO_(x)from mobile sources.Herein,we demonstrate the improved low-temperature activity and N_(2)selectivity by regulating the redox and acidic properties of MnCe oxides supported on etched ZSM-5 supports.The etched ZSM-5 enables the highly dispersed state of MnCeOx species and strong interaction between Mn and Ce species,which promotes the reduction of CeO2,facilitates electron transfer from Mn to Ce,and generates more Mn^(4+)and Ce^(3+)species.The strong redox capacity contributes to forming the reactive nitrate species and-NH_(2)species from oxidative dehydrogenation of NH_(3).Moreover,the adsorbed NH_(3)and-NH_(2)species are the reactive intermediates that promote the formation of N_(2).This work demonstrates an effective strategy to enhance the low-temperature activity and N_(2)selectivity of SCR catalysts,contributing to the NO_(x)control for the low-temperature exhaust gas during the cold-start of diesel vehicles.展开更多
Sn-based metal organic complexes with coordination bonds,multi-active sites,and high theoretical capacity have attracted much attention as promising anodes for lithium ion batteries.However,the low electrical conducti...Sn-based metal organic complexes with coordination bonds,multi-active sites,and high theoretical capacity have attracted much attention as promising anodes for lithium ion batteries.However,the low electrical conductivity and huge volume changes restricted their electrochemical stability and practical utilization.Herein,Snbased anode with superior electrochemical performance,including a high reversible capacity of 1050.1 mAh·g^(-1)at 2 A·g^(-1)and a stable capacity of 1105.5 mAh·g^(-1)after 500 cycles at 1 A·g^(-1),was fabricated via a low-temperature calcination strategy from Sn metal organic complexes.The low-temperature calcination process regulates Sn-O bond and prevents the agglomeration of SnO_(2),generating highly dispersed SnO_(2) decorated metal organic complexes and providing sufficient active sites for ion storage.Ex situ characterizations expound that the undecomposed Sn-based metal organic complexes could be transformed into SnO_(2) during lithiation and delithiation,which enhances the electrical conductivity and induces a strong pseudo-capacitive behavior,accelerating the electrochemical kinetics;the multiple solid electrolyte interface with inflexible LiF and flexible ROCO_(2)Li buffers the volume variation of the electrode,resulting in its high electrochemical stability.This work provides a simple strategy for preparing excellent Sn-based anodes from metal organic complexes and reveals the lithium storage mechanism of the prepared Snbased anode.展开更多
Correlations among free radicals, apparent activation energy, and functional groups during lowtemperature oxidation of Jurassic coal in Northern Shaanxi were investigated by examining three coal samples collected from...Correlations among free radicals, apparent activation energy, and functional groups during lowtemperature oxidation of Jurassic coal in Northern Shaanxi were investigated by examining three coal samples collected from the Ningtiaota, Jianxin, and Shigetai coal mines. Free radical concentrations at less than 120 ℃ were investigated by electron spin resonance experiments while the thermogravimetric experiments were conducted to analyze apparent activation energies. In addition, Fourier transform infrared spectroscopy was employed to study the spectrum of functional groups generated in coal. The results indicated that, in decreasing order, the apparent activation energies were Shigetai 〉Jianxin 〉 Ningtiaota, indicating that, from 50 to 120 ℃, the Ningtiaota coal sample most easily absorbed and reacted with oxygen while the most resistant was the Shigetai coal sample. Free radical concentrations and line heights increased with increased temperature, and the line width and Lande factor showed irregular fluctuations. Functional group variations were different among these coals, and the phenol and alcohol-associated OHs, carboxyls, and aromatic ring double bonds might have had a major impact on free radical concentrations. These results were meaningful for better consideration and management of coal oxidation at low temperatures.展开更多
The killing logarithms index in killing a vegetative form in an explosure of about 90s and a spore in an explosure of about 120s, by using a low-temperature plasma produced by dielectric barrier discharge （DBD）, rea...The killing logarithms index in killing a vegetative form in an explosure of about 90s and a spore in an explosure of about 120s, by using a low-temperature plasma produced by dielectric barrier discharge （DBD）, reached 5. The speed in killing the strains tested, by using a low-temperature plasma, was the highest with E. Coli, then S. Aureus and B. Subtilis var niger spore. The results of the scanning electron microscope showed that the low-temperature plasma destroyed the outer structure of the bacteria and that the vegetative form was more susceptible to the inactivation effect of the low-temperature plasma than was the spore. This indicated that the effects of the high voltage and high velocity particle flow, in plasma, penetrating through the outer structure of the bacteria might play a dominant role during the inactivation of the bacteria.展开更多
To expand the study on the structures and biological activities of the anthracyclines anticancer drugs and reduce their toxic side effects,the new anthraquinone derivatives,9‑pyridylanthrahydrazone(9‑PAH)and 9,10‑bisp...To expand the study on the structures and biological activities of the anthracyclines anticancer drugs and reduce their toxic side effects,the new anthraquinone derivatives,9‑pyridylanthrahydrazone(9‑PAH)and 9,10‑bispyridylanthrahydrazone(9,10‑PAH)were designed and synthesized.Utilizing 9‑PAH and 9,10‑PAH as promising anticancer ligands,their respective copper complexes,namely[Cu(L1)Cl_(2)]Cl(1)and{[Cu_(4)(μ_(2)‑Cl)_(3)Cl_(4)(9,10‑PAH)_(2)(DMSO)_(2)]Cl_(2)}_(n)(2),were subsequently synthesized,where the new ligand L1 is formed by coupling two 9‑PAH ligands in the coordination reaction.The chemical and crystal structures of 1 and 2 were elucidated by IR,MS,elemental analysis,and single‑crystal X‑ray diffraction.Complex 1 forms a mononuclear structure.L1 coordinates with Cu through its three N atoms,together with two Cl atoms,to form a five‑coordinated square pyramidal geometry.Complex 2 constitutes a polymeric structure,wherein each structural unit centrosymmetrically encompasses two five‑coordinated binuclear copper complexes(Cu1,Cu2)of 9,10‑PAH,with similar square pyramidal geometry.A chlorine atom(Cl_(2)),located at the symmetry center,bridges Cu1 and Cu1A to connect the two binuclear copper structures.Meanwhile,the two five‑coordinated Cu2 atoms symmetrically bridge the adjacent structural units via one coordinated Cl atom,respectively,thus forming a 1D chain‑like polymeric structure.In vitro anticancer activity assessments revealed that 1 and 2 showed significant cytotoxicity even higher than cisplatin.Specifically,the IC_(50)values of 2 against HeLa‑229 and SK‑OV‑3 cancer cell lines were determined to be(5.92±0.32)μmol·L^(-1)and(6.48±0.39)μmol·L^(-1),respectively.2 could also block the proliferation of HeLa‑229 cells in S phase and significantly induce cell apoptosis.In addition,fluorescence quenching competition experiments suggested that 2 might interact with DNA by an intercalative binding mode,offering insights into its underlying anticancer mechanism.CCDC:2388918,1;2388919,2.展开更多
Diabetes mellitus(DM)has become one of the most serious and common chronic diseases around the world,leading to various complications and a reduction in life expectancy.Increased sedentary behavior(SB)and decreased ph...Diabetes mellitus(DM)has become one of the most serious and common chronic diseases around the world,leading to various complications and a reduction in life expectancy.Increased sedentary behavior(SB)and decreased physical activity(PA)are important contributors to the rising prevalence of DM.This article reviews the research progress on the pathogenesis of DM,the effects of SB and PA on the risk of DM,aiming to explore the influence of different PA intensities,amounts,frequencies,durations and types on the incidence of DM.Research has shown that blood glucose levels tend to increase with the prolongation of SB.Within a certain range,PA intensity and PA amount are negatively correlated with the risk of DM;Performing PA for more than 3 days per week maintains normal glucose tolerance and lower blood pressure;Engaging in 150–300 min of moderate intensity exercise or 75–150 min of high-intensity exercise per week reduces the risk of DM;PA during leisure time reduces the risk of DM,while PA during work increases the risk of DM;Both aerobic training and resistance training reduce the risk of DM,and the combination of the two training methods produces better benefits;Various types of exercises,such as cycling,soccer,aerobics,yoga,tai chi,all reduce the risk of DM.In summary,prolonged SB increases the risk of DM,while appropriate PA reduces the risk of DM.As the intensity,amount,and frequency of PA increase,the effect of reducing DM risk becomes more significant.Different exercise methods have different effects on reducing DM risk.展开更多
基金the financial support from the Key Project of Shaanxi Provincial Natural Science Foundation-Key Project of Laboratory(2025SYS-SYSZD-117)the Natural Science Basic Research Program of Shaanxi(2025JCYBQN-125)+8 种基金Young Talent Fund of Xi'an Association for Science and Technology(0959202513002)the Key Industrial Chain Technology Research Program of Xi'an(24ZDCYJSGG0048)the Key Research and Development Program of Xianyang(L2023-ZDYF-SF-077)Postdoctoral Fellowship Program of CPSF(GZC20241442)Shaanxi Postdoctoral Science Foundation(2024BSHSDZZ070)Research Funds for the Interdisciplinary Projects,CHU(300104240913)the Fundamental Research Funds for the Central Universities,CHU(300102385739,300102384201,300102384103)the Scientific Innovation Practice Project of Postgraduate of Chang'an University(300103725063)the financial support from the Australian Research Council。
文摘Lithium-ion batteries(LIBs),while dominant in energy storage due to high energy density and cycling stability,suffer from severe capacity decay,rate capability degradation,and lithium dendrite formation under low-temperature(LT)operation.Therefore,a more comprehensive and systematic understanding of LIB behavior at LT is urgently required.This review article comprehensively reviews recent advancements in electrolyte engineering strategies aimed at improving the low-temperature operational capabilities of LIBs.The study methodically examines critical performance-limiting mechanisms through fundamental analysis of four primary challenges:insufficient ionic conductivity under cryogenic conditions,kinetically hindered charge transfer processes,Li+transport limitations across the solidelectrolyte interphase(SEI),and uncontrolled lithium dendrite growth.The work elaborates on innovative optimization approaches encompassing lithium salt molecular design with tailored dissociation characteristics,solvent matrix optimization through dielectric constant and viscosity regulation,interfacial engineering additives for constructing low-impedance SEI layers,and gel-polymer composite electrolyte systems.Notably,particular emphasis is placed on emerging machine learning-guided electrolyte formulation strategies that enable high-throughput virtual screening of constituent combinations and prediction of structure-property relationships.These artificial intelligence-assisted rational design frameworks demonstrate significant potential for accelerating the development of next-generation LT electrolytes by establishing quantitative composition-performance correlations through advanced data-driven methodologies.
基金financially supported by the National Natural Science Foundation of China(No.22309067)the Open Project Program of the State Key Laboratory of Materials-Oriented Chemical Engineering,China(No.KL21-05)the Marine Equipment and Technology Institute,Jiangsu University of Science and Technology,China(No.XTCX202404)。
文摘This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.1)Mo_(0.05)O_(3-δ)(B S CNM_(0.05)),Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.05)Mo_(0.1)O_(3-δ)(BSCNM_(0.1)),and Ba_(0.6)Sr_(0.4)Co_(0.85)Mo_(0.15)O_(3-δ)(BSCM)—with Mo doping contents of 5mol%,10mol%,and15mol%,respectively,were successfully prepared using the sol-gel method.The effects of Mo doping on the crystal structure,conductivity,thermal expansion coefficient,oxygen reduction reaction(ORR)activity,and electrochemical performance were systematically evaluated using X-ray diffraction analysis,thermally induced characterization,electrochemical impedance spectroscopy,and single-cell performance tests.The results revealed that Mo doping could improve the conductivity of the materials,suppress their thermal expansion effects,and significantly improve the electrochemical performance.Surface chemical state analysis using X-ray photoelectron spectroscopy revealed that 5mol%Mo doping could facilitate a high adsorbed oxygen concentration leading to enhanced ORR activity in the materials.Density functional theory calculations confirmed that Mo doping promoted the ORR activity in the materials.At an operating temperature of 600℃,the BSCNM_(0.05)cathode material exhibited significantly enhanced electrochemical impedance characteristics,with a reduced area specific resistance of 0.048Ω·cm~2,which was lower than that of the undoped BSCN matrix material by 32.39%.At the same operating temperature,an anode-supported single cell using a BSCNM_(0.05)cathode achieved a peak power density of 1477 mW·cm^(-2),which was 30.71%,56.30%,and 171.50%higher than those of BSCN,BSCNM_(0.1),and B SCM,respectively.The improved ORR activity and electrochemical performance of BSCNM_(0.05)indicate that it can be used as a cathode material in low-temperature solid oxide fuel cells.
文摘BACKGROUND Postoperative delirium(POD)is a common and serious complication in surgical patients,particularly older adults.Alterations in cholinergic function have been implicated in its pathophysiology.AIM To evaluate the association between preoperative serum cholinesterase(ChE)activity—specifically butyrylcholinesterase(BuChE)and acetylcholinesterase(AChE)—and the risk of POD in adult surgical patients in a meta-analysis.METHODS A systematic search was conducted in PubMed,EMBASE,and Web of Science up to March 28,2025 for studies reporting preoperative serum BuChE or AChE activity in relation to subsequent POD incidence.Standardized mean differences(SMDs)and odds ratios(ORs)with 95%confidence intervals(CIs)were pooled using random-effects models.Subgroup and sensitivity analyses were performed based on follow-up duration and analytic models.RESULTS Thirteen studies(n=2730 patients)were included.Patients who developed POD had significantly lower preoperative BuChE activity than those who did not(SMD=-0.28;95%CI:-0.39 to-0.16;I²=18%).Higher BuChE activity was associated with a reduced risk of POD(OR per 100 unit increment=0.97;95%CI:0.95-0.99;I2=0%).In contrast,pooled AChE activity did not differ significantly between POD and non-POD groups(SMD=-0.25;95%CI:-0.53 to 0.03;P=0.08;I2=80%),and the ORs per 1 unit increment in AChE activity were not statistically significant(OR=0.98;95%CI:0.95-1.01).CONCLUSION Lower preoperative serum BuChE activity is associated with an increased risk of POD in adults undergoing surgery.BuChE activity may serve as a potential preoperative biomarker for POD risk stratification.
基金supported by the Portuguese Foundation for Science and Technology(FCT)under the scope of the strategic funding of UIDB/04469/2020 unit and by the CM4Methane project(Ref:PTDC/BTA-BTA/2249/2021,DOI 10.54499/PTDC/BTABTA/2249/2021)FCT and European Union(EU),through the Portuguese State Budget and the European Social Fund under the scope of Norte2020-Programa Operacional Regional do Norte,also funded the SFRH/BD/132003/2017 and COVID/BD/152431/2022 grants held by Cátia S.N.Braga.,and the SFRH/BD/147271/2019 grant held by João C.Sequeira.M.SaloméDuarte acknowledges FCT for the Junior Research contract obtained under the scope of the Scientific Stimulus Employment 2022(ref:2022.06569.CEECIND/CP1718/CT0004,doi:https://doi.org/10.54499/2022.06569.CEECIND/CP1718/CT0004)PhD M.Fernando R.Pereira and PhD O.SaloméG.Soares from the Laboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials,Faculty of Engineering(University of Porto),for providing the AC used in this study.
文摘Conductive materials(CM)can improve methane production(MP)efficiency in many methanogenic systems.However,several types of CM exist,and there are uncertainties regarding whether they all improve MP efficiency to the same extent and modulate microbial communities in a similar way.To investigate that,different microbial enrichments with and without activated carbon(AC),magnetite(Mag),and zeolites(Zeo)(at 0.5 g/L)were developed.MP profiles and microbial composition changes were compared among enrichments.The behavior of all enrichments was different,although the initial inoculum sludge was the same.Lag phase duration was lower in AC enrichment,while the complete conversion of butyrate to methane was faster in Mag enrichment.Syntrophomonas was the most abundant bacterial genus in all enrichments,but changes in the methanogenic community were evident.Acetoclastic methanogens were more diverse in Mag enrichment,with microorganisms assigned to Methanosarcina and Methanothrix gener1,but Methanothrix was the only acetoclastic methanogen in the other enrichments.On the other hand,different species of hydrogenotrophic methanogens prevailed in distinct enrichments.The metatranscriptomics results revealed that the dominant mechanism of interspecies electron transfer in the AC enrichment utilized hydrogen as the electron carrier,and no evidences of direct interspecies electron transfer(DIET)could be found.These results showed how different CM modulate microbial communities and affect MP efficiency through mechanisms that do not necessarily involve DIET or mediation via CM.
基金Supported by Provincial Key Research Project of Henan Province,No.232102310081.
文摘BACKGROUND Major depressive disorder(MDD)and obesity(OB)are bidirectionally comorbid conditions with common neurobiological underpinnings.However,the neurocognitive mechanisms of their comorbidity remain poorly understood.AIM To examine regional abnormalities in spontaneous brain activity among patients with MDD-OB comorbidity.METHODS This study adopted a regional homogeneity(ReHo)analysis of resting-state functional magnetic resonance imaging.The study included 149 hospital patients divided into four groups:Patients experiencing their first episode of drug-naive MDD with OB,patients with MDD without OB,and age-and sex-matched healthy individuals with and without OB.Whole-brain ReHo analysis was conducted using SPM12 software and RESTplus toolkits,with group comparisons via ANOVA and post-hoc tests.Correlations between ReHo values and behavioral measures were examined.RESULTS ANOVA revealed significant whole-brain ReHo differences among the four groups in four key regions:The left middle temporal gyrus(MTG.L),right cuneus,left precuneus,and left thalamus.Post-hoc analyses confirmed pairwise differences between all groups across these regions(P<0.05).OB was associated with ReHo alterations in the MTG.L,right cuneus,and left thalamus,whereas abnormalities in the precuneus suggested synergistic pathological mechanisms between MDD and OB.Statistically significant correlations were found between the drive and fun-seeking dimensions of the behavioral activation system,as well as behavioral inhibition and the corresponding ReHo values.CONCLUSION Our findings provide novel evidence for the neuroadaptive mechanisms underlying the MDD-OB comorbidity.Further validation could lead to personalized interventions targeting MTG.L hyperactivity and targeting healthy food cues.
基金supported by the National Natural Science Foundation of China (Grant Nos.T2325027,12274448,T2350007,12404239,12174041,12325405,12090054,and T2221001)the National Key R&D Program of China (Grant No.2022YFF0503504)。
文摘The intrinsic pressure framework,which treats self-propelling force as an external force,provides a convenient and consistent description of mechanical equilibrium in active matter.However,direct experimental evidence is still lacking.To validate this framework,here we employ a programmable robotic platform,where a single light-controlled wheeled robot travels in an activity landscape.Our experiments quantitatively demonstrate that the intrinsic pressure difference across the activity interface is balanced by the emerged polarization force.This result unambiguously confirms the theoretical predictions,thus validating the intrinsic pressure framework and laying the experimental foundation for the intrinsic pressure-based mechanical description of dry active matter.
基金financial supports from the National Natural Science Foundation of China (Nos. 51822811, 21637005)the National Key R&D Program of China (Nos. 2017YFC0212502, 2017YFC0211101)the Young Talent Project of the Center for Excellence in Regional Atmospheric Environment, CAS (No. CERAE201806)
文摘Hierarchical Fe-Beta obtained by hydrothermal synthesis exhibited higher low-temperature NH_3-SCR activity than conventional Fe-Beta. In order to identify the main factors leading to the difference in catalytic activity, we investigated the pore structure, acidity and Fe sites of the hierarchical Fe-Beta and conventional Fe-Beta. The enhanced activity of hierarchical Fe-Beta was mainly due to the increase of the quantity of active Fe species. NH_3-TPD and DRIFTS results of NH_3 adsorption clearly verified that hierarchical Fe-Beta had more Lewis acid sites, which is beneficial to the adsorption and activation of NH_3. The H_2-TPR, UV–vis DRS, and EPR results confirmed that the hierarchical Fe-Beta had more isolated active Fe species, which may be associated with that the hierarchical structure introduced more structural defects as ion-exchange sites. Based on the analysis of kinetics experiments and the abovementioned characterizations, it can be concluded that the improvement of NH_3-SCR activity was not due to an intrinsic effect of the specific structural characteristics, but was related to more Fe active sites and better dispersion of Fe species in the hierarchical Fe-Beta.
文摘Active inflammation in“inactive”progressive multiple sclerosis:Traditionally,the distinction between relapsing-remitting multiple sclerosis and progressive multiple sclerosis(PMS)has been framed as an inflammatory versus degenerative dichotomy.This was based on a broad misconception regarding essentially all neurodegenerative conditions,depicting the degenerative process as passive and immune-independent occurring as a late byproduct of active inflammation in the central nervous system(CNS),which is(solely)systemically driven.
基金supported by the National Natural Science Foundation of China(22279025,21773048)the Natural Science Foundation of Heilongjiang Province(LH2021A013)+1 种基金the Sichuan Science and Technology Program(2021YFSY0022)the Fundamental Research Funds for the Central Universities(2023FRFK06005,HIT.NSRIF202204)。
文摘Developing efficient and stable cathodes for low-temperature solid oxide fuel cells(LT-SOFCs) is of great importance for the practical commercialization.Herein,we propose a series of Sm-modified Bi_(0.7-x)Sm_xSr_(0.3)FeO_(3-δ) perovskites as highly-active catalysts for LT-SOFCs.Sm doping can significantly enhance the electrocata lytic activity and chemical stability of cathode.At 600℃,Bi_(0.675)Sm_(0.025)Sr_(0.3)FeO_(3-δ)(BSSF25) cathode has been found to be the optimum composition with a polarization resistance of 0.098 Ω cm^2,which is only around 22.8% of Bi_(0.7)Sr_(0.3)FeO_(3-δ)(BSF).A full cell utilizing BSSF25 displays an exceptional output density of 790 mW cm^(-2),which can operate continuously over100 h without obvious degradation.The remarkable electrochemical performance observed can be attributed to the improved O_(2) transport kinetics,superior surface oxygen adsorption capacity,as well as O_(2)p band centers in close proximity to the Fermi level.Moreover,larger average bonding energy(ABE) and the presence of highly acidic Bi,Sm,and Fe ions restrict the adsorption of CO_(2) on the cathode surface,resulting in excellent CO_(2) resistivity.This work provides valuable guidance for systematic design of efficient and durable catalysts for LT-SOFCs.
基金Supported by the National High Technology Research and Development Program (863 Program) (No.2003AA625070)the Research Fund Program of Qingdao University (No.20051102)
文摘We extracted marine low-temperature lysozyme (MLTL),a novel lysozyme,from a marine microorganism through fermentation.Our previous study suggested that a low molecular weight (16 kDa) may exert anti-tumor activity through antiangiogenesis.In this study,we extracted a high weight (39 kDa) and investigated its antiangiogenic activity in vivo and in vitro.Using zebrafish embryos as an in vivo study model,we found that treatment with MLTL significantly inhibited the growth of subintestinal vessels (SIVs) in a dose-dependent manner and that 400 μg/ml MLTL was sufficient to block the growth of SIVs.An in vitro study conducted using human umbilical vein endothelial cells (HUVECs) revealed that MLTL suppressed the proliferation,migration and tube formation of HUVECs in a dose-dependent manner.Interestingly,assays by flow cytometry and DNA electrophoresis indicated that MLTL was able to induce apoptosis of HUVECs.Moreover,further study demonstrated that the disruption of intracellular Ca2+ homeostasis may play an important role in MLTL induced apoptosis of HUVECs.Taken together,the results of this study demonstrate for the first time that MLTL inhibits angiogenesis through its pleiotropic effects on vascular endothelial cells and induces apoptosis through regulation of cellular Ca2+ levels.The results of this study also revealed a possible mechanism underlying the antiangiogenic effect of MLTL and suggested that MLTL may be a promising new antiangiogenic agent for use in cancer therapy.
基金Project supported by the Alliance Project of Shanghai City in China(LM201641)。
文摘A series of TiO_(2)-Al_(2)O_(3) composites with Al/Ti molar ratios of 0.1,0.2,and 0.4 were synthesized by a coprecipitation method and used as supports to prepare supported MnCeO_(x) catalysts by an impregnation method.The physico-chemical properties of the samples were extensively characterized by N_(2) physisorption,X-ray diffraction,Raman spectroscopy,scanning electron micro scopy and energy-dispersive Xray spectroscopy element mapping,X-ray photoelectron spectroscopy,H_(2)-temperature programmed reduction,ammonia temperature programmed desorption,and in-situ diffuse reflectance infrared Fourier transform spectroscopy.The catalytic activity and resistance to water vapor and SO_(2) of the asprepared catalysts for the SCR of NO_(x) with NH_(3) were evaluated at 50-250℃ and GHSV of 80000 mL/(gcat·h).The results reveal that MnCeO_(x)/TiO_(2)-Al_(2)O_(3) exhibits higher activity and better SO_(2) tolerance than MnCeO_(x)/TiO_(2).Combining with the characterization results,the enhanced activity and SO_(2) tolerance of MnCeO_(x)/TiO_(2)-Al_(2)O_(3) can be mainly attributed to higher relative concentrations of Mn4+and chemisorbed oxygen species,stronger reducibility,and larger adsorption capacity for NH_(3) and NO,which originate from the larger specific surface area and pore volume,higher dispersion of Mn and Ce species compared with MnCeO_(x)/TiO_(2).Moreover,in situ DRIFTS was used to investigate the reaction mechanism,and the results indicate that the NH_(3)-SCR reaction over MnCeO_(x)/TiO_(2) and MnCeO_(x)/TiO_(2)-Al_(2)O_(3) takes place by both the E-R and L-H mechanisms.
基金supported by a grant from the National Key Research and Development Program of China (2016YFC0204300)the National Nature Science Foundation of China (21477109)。
文摘A series of CeO_(2)-TiO_(2)mixed oxides supports with various Ce/Ti molar ratio were synthesized by modified coprecipitation method. The corresponding Pt loaded(0.5 wt% Pt) catalysts were prepared by electronless deposition method and evaluated for the deep oxidation of n-hexane as a model VOCs. The results show that the CeO_(2)and TiOxnanoparticles can highly disperse into each other and form Ce_(2)Ti_(2)O_(7)solid solution with appropriate Ce/Ti molar ratio, which significantly improves their redox ability by enhancing the interaction between CeO_(2)and TiO_(x). The dispersibility of Pt species can also be adjusted by altering the Ce/Ti molar ratio, and Pt/CeTi-2/1 catalyst with Ce/Ti molar ratio of 2:1 exhibits the best Pt dispersibility that Pt species mainly exist as Pt single atoms. The high dispersion of Pt species in the Pt/CeO_(2)-TiO_(2)catalysts would promote the catalytic activity of VOCs oxidation with low T90% values(1000 ppm, GHSV = 15,000 h^(-1)), such as for n-hexane degradation with T90% of 139℃. The characterizations reveal that the superior activity is mainly related to possessing the more Pt2+species,adsorbed oxygen species and higher low-temperature reducibility owing to the strong interaction between highly dispersed Pt species and CeO_(2)-TiO_(2)as well as the promoted migration of lattice oxygen by the formation of more Ce_(2)Ti_(2)O_(7)species. Furthermore, the Pt/CeTi-2/1 catalyst also exhibits excellent stability for chlorinated and other non-chlorinated VOCs oxidation, making it very promising for real application under various operating conditions.
基金The authors acknowledge financial support from the National Natural Science Foundation of China(Grant Nos.51771114,51371117).
文摘The distinctive distribution of acoustic emission(AE)characteristic parameters generated during tensile testing of low-temperature tempered AISI 4140 steel was investigated.Two clusters of acoustic emission signals were distinguished using power-law distribution fitting and k-means clustering methods.These clusters were identified as resulting from dislocation motion during yielding and dislocation entanglement during uniform plastic deformation.The conclusion is further confirmed by transmission electron microscopy images at different strains.In particular,the unique"arch-shaped"distribution of the acoustic emission energy during yielding implies a change in unusual dislocation motion modes.The effect of carbide precipitation was qualitatively discussed as not considering the primary cause of the formation of this arch-shaped distribution.The evolution of dislocation motion modes during yielding of low-temperature tempered martensite was elucidated by comparing the significant difference in cumulative energy values during yielding of annealed and low-temperature tempered specimens.Dislocations emit from Frank–Read or grain boundary sources and slip along short free paths,contributing to the initial increase in AE signals energy.Subsequently,the primary source of acoustic emission energy“arch-shaped”peak during yielding was generated by the avalanche behavior of accumulated dislocations,leading to the accelerated dislocation motion.
文摘The distributions of framework aluminum(Al)in zeolites critically govern the location and speciation of active copper(Cu)centers,thereby influencing their performance in ammonia selective catalytic reduction(NH_(3)-SCR)of nitrogen oxides(NO_(x)).Conventional Cu-SSZ-39(Cu-SSZ-39-T)exhibits excellent hydrothermal stability but limited low-temperature activity(150–225℃)due to a low concentration of Al in 8-membered rings(8MRs)that inhibits the formation of active[Cu(OH)]^(+)-Z species.Herein,an SSZ-39 zeolite synthesized with potassium ions(SSZ-39-K)achieved a significantly higher 8MR Al fraction(37.6%).Density functional theory calculations and H_(2)-temperature-programmed reduction analyses confirmed that the increased 8MR Al population facilitated the formation of[Cu(OH)]^(+)-Z species.Aged Cu-SSZ-39-K exhibited nearly twice the NO_(x)conversion of aged Cu-SSZ-39-T in the 150–225℃range while maintaining comparable high-temperature activity(250–550℃)under a gas hourly space velocity of 250,000 h^(-1).Enhanced low-temperature performance is particularly beneficial for mitigating NO_(x)emissions during cold-start phase.Moreover,SSZ-39-K was synthesized with a high crystallization yield(~65%),nearly double the highest yield(33%)reported for direct synthesis routes.This work establishes a robust strategy for tailoring Al distributions in SSZ-39 zeolites,offering an effective pathway to improve low-temperature NH_(3)-SCR performance and promote practical implementation.
基金the National Natural Science Foundation of China(Nos.22125604,22106100,21976117,22276119)Shanghai Rising-Star Program(No.22QA1403700).
文摘Developing a high-efficiency catalyst with both superior low-temperature activity and good N_(2)selectivity is still challenging for the NH_(3)selective catalytic reduction(SCR)of NO_(x)from mobile sources.Herein,we demonstrate the improved low-temperature activity and N_(2)selectivity by regulating the redox and acidic properties of MnCe oxides supported on etched ZSM-5 supports.The etched ZSM-5 enables the highly dispersed state of MnCeOx species and strong interaction between Mn and Ce species,which promotes the reduction of CeO2,facilitates electron transfer from Mn to Ce,and generates more Mn^(4+)and Ce^(3+)species.The strong redox capacity contributes to forming the reactive nitrate species and-NH_(2)species from oxidative dehydrogenation of NH_(3).Moreover,the adsorbed NH_(3)and-NH_(2)species are the reactive intermediates that promote the formation of N_(2).This work demonstrates an effective strategy to enhance the low-temperature activity and N_(2)selectivity of SCR catalysts,contributing to the NO_(x)control for the low-temperature exhaust gas during the cold-start of diesel vehicles.
基金financially supported by the Program for Science&Technology Innovation Talents in Universities of Henan Province(No.24HASTIT006)the Natural Science Foundations of China(No.42002040)+2 种基金Natural Science Foundations of Henan Province(No.222300420502)Key Science and Technology Program of Henan Province(No.222102240044)Key Scientific Research Projects in Colleges and Universities of Henan Province(No.21B610010)。
文摘Sn-based metal organic complexes with coordination bonds,multi-active sites,and high theoretical capacity have attracted much attention as promising anodes for lithium ion batteries.However,the low electrical conductivity and huge volume changes restricted their electrochemical stability and practical utilization.Herein,Snbased anode with superior electrochemical performance,including a high reversible capacity of 1050.1 mAh·g^(-1)at 2 A·g^(-1)and a stable capacity of 1105.5 mAh·g^(-1)after 500 cycles at 1 A·g^(-1),was fabricated via a low-temperature calcination strategy from Sn metal organic complexes.The low-temperature calcination process regulates Sn-O bond and prevents the agglomeration of SnO_(2),generating highly dispersed SnO_(2) decorated metal organic complexes and providing sufficient active sites for ion storage.Ex situ characterizations expound that the undecomposed Sn-based metal organic complexes could be transformed into SnO_(2) during lithiation and delithiation,which enhances the electrical conductivity and induces a strong pseudo-capacitive behavior,accelerating the electrochemical kinetics;the multiple solid electrolyte interface with inflexible LiF and flexible ROCO_(2)Li buffers the volume variation of the electrode,resulting in its high electrochemical stability.This work provides a simple strategy for preparing excellent Sn-based anodes from metal organic complexes and reveals the lithium storage mechanism of the prepared Snbased anode.
基金supported by the Key Projects of the National Natural Science Foundation of China (Nos. 51504187, 51774233, and 51704226)Shaanxi Province Industrial Science and Technology Research Project (No. 2016GY-192)the China Postdoctoral Science Foundation (No. 2016-M-590963)
文摘Correlations among free radicals, apparent activation energy, and functional groups during lowtemperature oxidation of Jurassic coal in Northern Shaanxi were investigated by examining three coal samples collected from the Ningtiaota, Jianxin, and Shigetai coal mines. Free radical concentrations at less than 120 ℃ were investigated by electron spin resonance experiments while the thermogravimetric experiments were conducted to analyze apparent activation energies. In addition, Fourier transform infrared spectroscopy was employed to study the spectrum of functional groups generated in coal. The results indicated that, in decreasing order, the apparent activation energies were Shigetai 〉Jianxin 〉 Ningtiaota, indicating that, from 50 to 120 ℃, the Ningtiaota coal sample most easily absorbed and reacted with oxygen while the most resistant was the Shigetai coal sample. Free radical concentrations and line heights increased with increased temperature, and the line width and Lande factor showed irregular fluctuations. Functional group variations were different among these coals, and the phenol and alcohol-associated OHs, carboxyls, and aromatic ring double bonds might have had a major impact on free radical concentrations. These results were meaningful for better consideration and management of coal oxidation at low temperatures.
文摘The killing logarithms index in killing a vegetative form in an explosure of about 90s and a spore in an explosure of about 120s, by using a low-temperature plasma produced by dielectric barrier discharge （DBD）, reached 5. The speed in killing the strains tested, by using a low-temperature plasma, was the highest with E. Coli, then S. Aureus and B. Subtilis var niger spore. The results of the scanning electron microscope showed that the low-temperature plasma destroyed the outer structure of the bacteria and that the vegetative form was more susceptible to the inactivation effect of the low-temperature plasma than was the spore. This indicated that the effects of the high voltage and high velocity particle flow, in plasma, penetrating through the outer structure of the bacteria might play a dominant role during the inactivation of the bacteria.
文摘To expand the study on the structures and biological activities of the anthracyclines anticancer drugs and reduce their toxic side effects,the new anthraquinone derivatives,9‑pyridylanthrahydrazone(9‑PAH)and 9,10‑bispyridylanthrahydrazone(9,10‑PAH)were designed and synthesized.Utilizing 9‑PAH and 9,10‑PAH as promising anticancer ligands,their respective copper complexes,namely[Cu(L1)Cl_(2)]Cl(1)and{[Cu_(4)(μ_(2)‑Cl)_(3)Cl_(4)(9,10‑PAH)_(2)(DMSO)_(2)]Cl_(2)}_(n)(2),were subsequently synthesized,where the new ligand L1 is formed by coupling two 9‑PAH ligands in the coordination reaction.The chemical and crystal structures of 1 and 2 were elucidated by IR,MS,elemental analysis,and single‑crystal X‑ray diffraction.Complex 1 forms a mononuclear structure.L1 coordinates with Cu through its three N atoms,together with two Cl atoms,to form a five‑coordinated square pyramidal geometry.Complex 2 constitutes a polymeric structure,wherein each structural unit centrosymmetrically encompasses two five‑coordinated binuclear copper complexes(Cu1,Cu2)of 9,10‑PAH,with similar square pyramidal geometry.A chlorine atom(Cl_(2)),located at the symmetry center,bridges Cu1 and Cu1A to connect the two binuclear copper structures.Meanwhile,the two five‑coordinated Cu2 atoms symmetrically bridge the adjacent structural units via one coordinated Cl atom,respectively,thus forming a 1D chain‑like polymeric structure.In vitro anticancer activity assessments revealed that 1 and 2 showed significant cytotoxicity even higher than cisplatin.Specifically,the IC_(50)values of 2 against HeLa‑229 and SK‑OV‑3 cancer cell lines were determined to be(5.92±0.32)μmol·L^(-1)and(6.48±0.39)μmol·L^(-1),respectively.2 could also block the proliferation of HeLa‑229 cells in S phase and significantly induce cell apoptosis.In addition,fluorescence quenching competition experiments suggested that 2 might interact with DNA by an intercalative binding mode,offering insights into its underlying anticancer mechanism.CCDC:2388918,1;2388919,2.
基金Key Project of Undergraduate Teaching Reform Research of Shandong Normal University(No.2024ZJ12)sixth batch of"Sports and Health"special topic of Education Research of Chinese Society of Education。
文摘Diabetes mellitus(DM)has become one of the most serious and common chronic diseases around the world,leading to various complications and a reduction in life expectancy.Increased sedentary behavior(SB)and decreased physical activity(PA)are important contributors to the rising prevalence of DM.This article reviews the research progress on the pathogenesis of DM,the effects of SB and PA on the risk of DM,aiming to explore the influence of different PA intensities,amounts,frequencies,durations and types on the incidence of DM.Research has shown that blood glucose levels tend to increase with the prolongation of SB.Within a certain range,PA intensity and PA amount are negatively correlated with the risk of DM;Performing PA for more than 3 days per week maintains normal glucose tolerance and lower blood pressure;Engaging in 150–300 min of moderate intensity exercise or 75–150 min of high-intensity exercise per week reduces the risk of DM;PA during leisure time reduces the risk of DM,while PA during work increases the risk of DM;Both aerobic training and resistance training reduce the risk of DM,and the combination of the two training methods produces better benefits;Various types of exercises,such as cycling,soccer,aerobics,yoga,tai chi,all reduce the risk of DM.In summary,prolonged SB increases the risk of DM,while appropriate PA reduces the risk of DM.As the intensity,amount,and frequency of PA increase,the effect of reducing DM risk becomes more significant.Different exercise methods have different effects on reducing DM risk.
