To investigate the effect of bowed/leaned vane configurations on the aerodynamic performance and aerodynamic excitation in transonic high-pressure turbine, the full three-dimensional viscous unsteady numerical simulat...To investigate the effect of bowed/leaned vane configurations on the aerodynamic performance and aerodynamic excitation in transonic high-pressure turbine, the full three-dimensional viscous unsteady numerical simulation was performed by solving N-S equations based on SAS SST method.The influence of bowed/leaned vanes on turbine efficiency and efficiency fluctuation was investigated. The action of vane modelling to the overall aerodynamic fluctuation level and the amplitude of each vane passing frequency were analyzed. By comparing instantaneous pressure fluctuation contours in the blade passage with space-time maps, the link of the pressure fluctuation on blade surface with flow distortions was achieved, which can reveal the mechanism of the impact of the vane modelling. As the results suggest, the turbine efficiency is promoted with positively leaned and bowed vane modelling, and the fluctuation of stage turbine efficiency is repressed, which contributes to the smooth running of the turbine stage. The blade aerodynamic excitation on the rotor blade is characterized by the motion of vane trailing edge shock system, and the vane configurations can reduce the fluctuation level on the rotor blade surface effectively. For the positively leaned vane configuration, the aerodynamic excitations at the root and tip region are affected by the impact of the amplitude of the first harmonic, whereas they are reduced with the decrease of the amplitude of the second and higher harmonics at midspan. For the positively bowed vane, aerodynamic excitation is repressed by reducing the amplitude of the third harmonic at the root region, and the first harmonic at the tip region, and the amplitude of each harmonic is reduced at the middle region.展开更多
Dear Editor,The Hans Chinese(HC)ethnic group,comprising approximately 1.4 billion individuals,represents the largest workforce globally.Historically,HC has been predominantly isolated from other ethnic groups for over...Dear Editor,The Hans Chinese(HC)ethnic group,comprising approximately 1.4 billion individuals,represents the largest workforce globally.Historically,HC has been predominantly isolated from other ethnic groups for over 3 millennia,resulting in distinct genetic and physiological characteristics[1,2].Consequently,the energy required to maintain essential functions,represented by the basal metabolic rate(BMR),cannot be accurately assessed in HC with algorithms developed for European-American(EA)populations,even when controlling for diff erences in body size[3].Notably,the widely used Harris-Benedict equation tends to overestimate BMR,relative to measured BMR via indirect calorimetry,in more than 50%of HC individuals[3].Hence,HC generally expends less energy than EA under basal(resting)conditions.This raises an important question:does HC require lower energy expenditure than EA for equivalent external work?Th e present aimed to address this inquiry,while adjusting for key confounding factors such as age,sex,physical activity,aerobic capacity,BMR,and body composition.展开更多
Lithium-sulfur batteries(LSBs)hold significant promise as advanced energy storage systems due to their high energy density,low cost,and environmental advantages.However,despite recent advancements,their practical ener...Lithium-sulfur batteries(LSBs)hold significant promise as advanced energy storage systems due to their high energy density,low cost,and environmental advantages.However,despite recent advancements,their practical energy density still falls short of the levels required for commercial viability.The energy density is critically dependent on both sulfur loading and the amount of electrolyte used.Highsulfur loading coupled with lean electrolyte conditions presents several challenges,including the insulating nature of sulfur and Li_(2)S,insufficient electrolyte absorption,degradation of the cathode structure,severe lithium polysulfide shuttling,slow redox reaction kinetics,and instability of the Li metal anode.MXenes-based materials,with their metallic conductivity,large polar surfaces,and abundant active sites,have been identified as promising electrocatalysts to improve the redox reactions in LSBs.This review focuses on the significance and challenges associated with high-sulfur loading and lean electrolytes in LSBs,highlighting recent advancements in MXenes-based electrocatalysts aimed at optimizing sulfur cathodes and lithium anodes.It provides a comprehensive discussion on MXenes as both active materials and substrates in LSBs,with the goal of enhancing understanding of the regulatory mechanisms that govern sulfur conversion reactions and lithium plating/stripping behavior.Finally,the review explores future opportunities for MXenes-based electrocatalysts,paving the way for the practical application of LSBs.展开更多
Over the past few years,the Cu element has attracted much attention in duplex stainless steels.It undoubtedly holds advantageous in regulating the two-phase proportion and austenite stability and is also one of the cr...Over the past few years,the Cu element has attracted much attention in duplex stainless steels.It undoubtedly holds advantageous in regulating the two-phase proportion and austenite stability and is also one of the crucial factors affecting the corrosion resistance.However,the systematic research on the impact of Cu addition to lean duplex stainless steels remains insufficient.In this study,a novel Cu-alloyed Mn-N-type 20Cr lean duplex stainless steel was developed and the effect of Cu on the strain hardening capacity and corrosion resistance was analyzed.The results show that the Cu addition increases the volume fraction and stability of the austenite,retards the martensitic transformation,and extends the transformation-induced plasticity effect to a wider strain range.Compared to the Cu-free steel,the plasticity of Cu-containing steel can be increased by~26%.Additionally,the addition of Cu redistributes the Cr and N elements in the ferrite and austenite phases,thereby improving the corrosion resistance of the lean duplex stainless steel.展开更多
Objective:To evaluate the application value of lean management in the management of flexible endoscopes.Methods:From January to December 2023,routine management was implemented,and 200 flexible endoscopes used for exa...Objective:To evaluate the application value of lean management in the management of flexible endoscopes.Methods:From January to December 2023,routine management was implemented,and 200 flexible endoscopes used for examination and treatment were included in the control group;from January to December 2024,lean management was implemented,and 200 flexible endoscopes used for examination and treatment were included in the observation group.The average daily usage frequency,management effectiveness,and failure rate of flexible endoscopes were compared between the two groups.Results:The average daily usage frequency of flexible endoscopes in the observation group was higher than that in the control group(P<0.05);the 3S retrieval rate and spot-check qualification rate of endoscopes in the observation group were higher than those in the control group(P<0.05);the failure rate of flexible endoscopes in the observation group was lower than that in the control group(P<0.05).Conclusion:Implementing lean management during the management of flexible endoscopes can improve the efficiency of endoscope retrieval,increase the average daily usage frequency of flexible endoscopes,and reduce endoscope failures.展开更多
This study systematically investigated the Lean Blowoff(LBO)limits of Two-Dimensional(2D)bluff-body stabilized premixed flames by varying the air mass flow rate,inflowtemperature,bluff-body width,and fuel type.The dat...This study systematically investigated the Lean Blowoff(LBO)limits of Two-Dimensional(2D)bluff-body stabilized premixed flames by varying the air mass flow rate,inflowtemperature,bluff-body width,and fuel type.The data of LBO limits were analyzed and fittedaccording to the Damk?hler(Da)and Reynolds(Re)numbers,and the fitting accuracy of LBO datawas highly improved by a modified characteristic length simultaneously considering the length andwidth of the bluff body,which is usually neglected in the previous studies.Moreover,to our knowl-edge,this is the first time that simultaneous transverse and spanwise OH*-Chemiluminescence(CL)imaging has been performed to examine the three-dimensional behavior of the LBO process.The flame stability is heavily affected by the mass and energy transport between reactants andproducts in both directions,potentially leading to the flame pinch-off.The intensity and positionof the upstream flame after pinch-off are decisive to the occurrence of the following LBO.Whenthe upstream flame after pinch-off is weak and close to the bluff body,it cannot re-ignite thedownstream unburnt gas.Subsequently,a permanent downstream extinction occurs,and theLBO takes place.The results help understand the LBO mechanism of 2D bluff-body stabilizedflames.展开更多
The prevalence of metabolic-associated fatty liver disease(MAFLD)has increased substantially in recent years because of the global obesity pandemic.MAFLD,now recognized as the number one cause of chronic liver disease...The prevalence of metabolic-associated fatty liver disease(MAFLD)has increased substantially in recent years because of the global obesity pandemic.MAFLD,now recognized as the number one cause of chronic liver disease in the world,not only increases liver-related morbidity and mortality among sufferers but also worsens the complications associated with other comorbid conditions such as cardiovascular disease,type 2 diabetes mellitus,obstructive sleep apnoea,lipid disorders and sarcopenia.Understanding the interplay between MAFLD and these comorbidities is important to design optimal therapeutic strategies.Sarcopenia can be either part of the disease process that results in MAFLD(e.g.,obesity or adiposity)or a consequence of MAFLD,especially in the advanced stages such as fibrosis and cirrhosis.Sarcopenia can also worsen MAFLD by reducing exercise capacity and by the production of various muscle-related chemical factors.Therefore,it is crucial to thoroughly understand how we deal with these diseases,especially when they coexist.We explore the pathobiological interlinks between MAFLD and sarcopenia in this comprehensive clinical update review article and propose evidence-based therapeutic strategies to enhance patient care.展开更多
Background Pediatric cancer survivors are at increased risk of muscle weakness and low areal bone mineral density(aBMD).However,the prevalence of muscle strength deficits is not well documented,and the associations of...Background Pediatric cancer survivors are at increased risk of muscle weakness and low areal bone mineral density(aBMD).However,the prevalence of muscle strength deficits is not well documented,and the associations of muscle strength with aBMD are unknown in this population.Therefore,this study aimed to investigate the prevalence of upper-and lower-body muscle strength deficits and to examine the associations of upper-and lower-body muscle strength with age-,sex,and race-specific aBMD Z-scores at the total body,total hip,femoral neck,and lumbar spine.Methods This cross-sectional study included 116 pediatric cancer survivors(12.1±3.3 years old,mean±SD;42.2%female).Upper-and lower-body muscle strength were assessed by handgrip and standing long jump test,respectively.Dual‑energy X‑ray absorptiometry was used to measure aBMD(g/cm2).Associations between muscle strength and aBMD were evaluated in multivariable linear regression models.Logistic regression was used to evaluate the contribution of muscle strength(1-decile lower)to the odds of having low aBMD(Z-score≤1.0).All analyses were adjusted for time from treatment completion,radiotherapy exposure,and body mass index.Results More than one-half of survivors were within the 2 lowest deciles for upper-(56.9%)and lower-body muscle strength(60.0%)in comparison to age-and sex-specific reference values.Muscle strength deficits were associated with lower aBMD Z-scores at all sites(B=0.133–0.258,p=0.001–0.032).Each 1-decile lower in upper-body muscle strength was associated with 30%–95%higher odds of having low aBMD Z-scores at all sites.Each 1-decile lower in lower-body muscle strength was associated with 35%–70%higher odds of having low aBMD Z-scores at total body,total hip,and femoral neck.Conclusion Muscle strength deficits are prevalent in young pediatric cancer survivors,and such deficits are associated with lower aBMD Z-scores at all sites.These results suggest that interventions designed to improve muscle strength in this vulnerable population may have the added benefit of improving aBMD.展开更多
Proper matching of cold-rolled deformation and low-temperature short-term aging can simultaneously enhance the strength and ductility of the lean duplex stainless steel. To investigate this, the microstructure evoluti...Proper matching of cold-rolled deformation and low-temperature short-term aging can simultaneously enhance the strength and ductility of the lean duplex stainless steel. To investigate this, the microstructure evolution of cold-rolled and aging steels was observed by using scanning electron microscopy, transmission electron microscopy and electron backscattered diffraction. Additionally, the phase volume fraction was measured using X-ray diffraction. In this study, it was observed that the elongation of 21Cr lean duplex stainless steel significantly increased to 16.7% after undergoing moderate cold deformation (~ 40% reduction) and subsequent aging treatment at 550 ℃ for 30 min. Remarkably, the material still maintained a high yield strength of 1045 MPa. Such an excellent mechanical property was attributed to a unique microstructure combination of fine α'-martensite, twins, coarsened austenite resulting from partial martensite reverse transformation, and two-phase fine layered structure. The result of this study may open up new horizons for the alloy development in order to overcome the low ductility of cold-rolled high-strength lean duplex stainless steel.展开更多
The effects of nano-CaO contents on the microstructure,mechanical properties and corrosion resistance of lean Mg-1Zn alloy were investigated.The results showed that the addition of nano-CaO significantly refined the g...The effects of nano-CaO contents on the microstructure,mechanical properties and corrosion resistance of lean Mg-1Zn alloy were investigated.The results showed that the addition of nano-CaO significantly refined the grain size and improved mechanical properties of the Mg-1Zn alloy.At the same time,CaO reacted with molten Mg in situ to form nano-MgO,whose corrosion product in SBF solution was the same with the degradation product of Mg matrix,resulting in the enhanced compactness of the Mg(OH)_(2) layer and reduced corrosion rate of matrix.The Mg-1Zn alloy had lower corrosion resistance due to excessively large grain size and shedding of corrosion products.The composite with 0.5 wt.%CaO had the best corrosion resistance with a weight loss of 9.875 mg·y^(-1)·mm^(-2)due to the small number of Ca_(2)Mg_(6)Zn_(3) phase and suitable grain size.While for composites with high content of CaO(0.7 wt.%and 1.0 wt.%),they had lower corrosion resistance due to the coexistence of large number of Ca_(2)Mg_(6)Zn_(3) and Mg_(2)Ca at grain boundaries,especially for 1.0 wt.%CaO composite,resulting from the strong micro-galvanic corrosion.展开更多
Epilepsy can be defined as a dysfunction of the brain network,and each type of epilepsy involves different brain-network changes that are implicated diffe rently in the control and propagation of interictal or ictal d...Epilepsy can be defined as a dysfunction of the brain network,and each type of epilepsy involves different brain-network changes that are implicated diffe rently in the control and propagation of interictal or ictal discharges.Gaining more detailed information on brain network alterations can help us to further understand the mechanisms of epilepsy and pave the way for brain network-based precise therapeutic approaches in clinical practice.An increasing number of advanced neuroimaging techniques and electrophysiological techniques such as diffusion tensor imaging-based fiber tra ctography,diffusion kurtosis imaging-based fiber tractography,fiber ball imagingbased tra ctography,electroencephalography,functional magnetic resonance imaging,magnetoencephalography,positron emission tomography,molecular imaging,and functional ultrasound imaging have been extensively used to delineate epileptic networks.In this review,we summarize the relevant neuroimaging and neuroelectrophysiological techniques for assessing structural and functional brain networks in patients with epilepsy,and extensively analyze the imaging mechanisms,advantages,limitations,and clinical application ranges of each technique.A greater focus on emerging advanced technologies,new data analysis software,a combination of multiple techniques,and the construction of personalized virtual epilepsy models can provide a theoretical basis to better understand the brain network mechanisms of epilepsy and make surgical decisions.展开更多
BACKGROUND A new nomenclature consensus has emerged for liver diseases that were previously known as non-alcoholic fatty liver disease(NAFLD)and metabolic dysfunction-associated fatty liver disease(MAFLD).They are now...BACKGROUND A new nomenclature consensus has emerged for liver diseases that were previously known as non-alcoholic fatty liver disease(NAFLD)and metabolic dysfunction-associated fatty liver disease(MAFLD).They are now defined as metabolic dysfunction-associated steatotic liver disease(MASLD),which includes cardiometabolic criteria in adults.This condition,extensively studied in obese or overweight patients,constitutes around 30%of the population,with a steady increase worldwide.Lean patients account for approximately 10%-15%of the MASLD population.However,the pathogenesis is complex and is not well understood.AIM To systematically review the literature on the diagnosis,pathogenesis,characteristics,and prognosis in lean MASLD patients and provide an interpretation of these new criteria.METHODS We conducted a comprehensive database search on PubMed and Google Scholar between January 2012 and September 2023,specifically focusing on lean NAFLD,MAFLD,or MASLD patients.We include original articles with patients aged 18 years or older,with a lean body mass index categorized according to the World Health Organization criteria,using a cutoff of 25 kg/m2 for the general population and 23 kg/m2 for the Asian population.RESULTS We include 85 studies in our analysis.Our findings revealed that,for lean NAFLD patients,the prevalence rate varied widely,ranging from 3.8%to 34.1%.The precise pathogenesis mechanism remained elusive,with associations found in genetic variants,epigenetic modifications,and adaptative metabolic response.Common risk factors included metabolic syndrome,hypertension,and type 2 diabetes mellitus,but their prevalence varied based on the comparison group involving lean patients.Regarding non-invasive tools,Fibrosis-4 index outperformed the NAFLD fibrosis score in lean patients.Lifestyle modifications aided in reducing hepatic steatosis and improving cardiometabolic profiles,with some medications showing efficacy to a lesser extent.However,lean NAFLD patients exhibited a worse prognosis compared to the obese or overweight counterpart.CONCLUSION MASLD is a complex disease comprising epigenetic,genetic,and metabolic factors in its pathogenesis.Results vary across populations,gender,and age.Limited data exists on clinical practice guidelines for lean patients.Future studies employing this new nomenclature can contribute to standardizing and generalizing results among lean patients with steatotic liver disease.展开更多
Batteries that utilize low-cost elemental sulfur and light metallic lithium as electrodes have great potential in achieving high energy density.However,building a lithium-sulfur(Li-S)full battery by controlling the el...Batteries that utilize low-cost elemental sulfur and light metallic lithium as electrodes have great potential in achieving high energy density.However,building a lithium-sulfur(Li-S)full battery by controlling the electrolyte volume generally produces low practical energy because of the limited electrochemical Li-S redox.Herein,the high energy/high performance of a Li-S full battery with practical sulfur loading and minimum electrolyte volume is reported.A unique hybrid architecture configured with Ni-Co metal alloy(NiCo)and metal oxide(NiCoO_(2))nanoparticles heterogeneously anchored in carbon nanotube-embedded selfstanding carbon matrix is fabricated as a host for sulfur.This work demonstrates the considerable improvement that the hybrid structure's high conductivity and satisfactory porosity promote the transport of electrons and lithium ions in Li-S batteries.Through experimental and theoretical validations,the function of NiCo and NiCoO_(2) nanoparticles as an efficient polysulfide mediator is established.These particles afford polysulfide anchoring and catalytic sites for Li-S redox reaction,thus improving the redox conversion reversibility.Even at high sulfur loading,the nanostructured Ni-Co metal alloy and metal oxide enable to have stable cycling performance under lean electrolyte conditions both in half-cell and full-cell batteries using a graphite anode.展开更多
Confucius said,“To know what you know and what you do not know, that is true knowledge.”Hartemink (2006) edited a prescient book on the future of soil science, the contents of which are worthy of consideration today...Confucius said,“To know what you know and what you do not know, that is true knowledge.”Hartemink (2006) edited a prescient book on the future of soil science, the contents of which are worthy of consideration today. Since then, there has been a growing emphasis on soil carbon, soil health, and soil security, as well as increased capability of technology related to machine leaning and soil sensing and measurement.SOIL KNOWLEDGE DISCOVERY CATEGORISATION Based on the above ancient aphorism attributed to Confucius, the author writing in Hartemink (2006) classified soil knowledge and knowledge discovery into 4 categories. An updated version is given in Fig. 1.展开更多
The practical energy density of lithium-sulfur batteries(LSBs)is seriously limited by the high electrolyte-to-sulfur ratios(E/S).The E/S can be reduced by employing hosts with easy-to-infiltrate structure that ensures...The practical energy density of lithium-sulfur batteries(LSBs)is seriously limited by the high electrolyte-to-sulfur ratios(E/S).The E/S can be reduced by employing hosts with easy-to-infiltrate structure that ensures the uniform distribution of a lean electrolyte and high catalytic activity that can suppress"shuttle effect"via accelerating the slow conversion of soluble poly sulfides to insoluble sulfides.Among the easy-to-infiltrate structures,the three-dimensional-ordered macroporous(3DOM)structure is easier to scale preparation and more suitable for the existing industrial processes.However,it is difficult to obtain the 3DOM with(1)high penetrability due to the high viscosity of frequently-used organic polymer precursors and(2)high catalytic activity due to the low confinement effect,meaning that uniformly dispersed small-sized catalytic materials are difficult to load on 3DOM.Herein,using carbon dots(CDs)with both organic and inorganic properties as a precursor and aggregation limiting agent,a 3DOM host with high penetrability and homodispersed Ni particles of small sizes(Ni-CDs-3DOM)was synthesized.In this host:(1)CDs precursor with suitable viscosity can improve the penetrability.(2)CDs can effectively inhibit the agglomeration of Ni particles.(3)Uniformly dispersed small-size Ni particles offer high-efficiency catalytic activity toward sulfur reactions.Consequently,the Ni-CDs-3DOM/sulfur cathode exhibits high sulfur utilization and stable cycling performance even under high sulfur loading(5.5 mg·cm^(-2))and low E/S(6.5μl·mg^(-1)).This work indicates the usefulness of CDs in constructing hosts for LSBs with high energy density.展开更多
Background:The association between non-obese or lean nonalcoholic fatty liver disease(NAFLD)and gallbladder polyps(GBPs)has not yet been evaluated.We aimed to determine whether NAFLD is an independent risk factor for ...Background:The association between non-obese or lean nonalcoholic fatty liver disease(NAFLD)and gallbladder polyps(GBPs)has not yet been evaluated.We aimed to determine whether NAFLD is an independent risk factor for the development of GBPs,even in non-obese and lean individuals.Methods:We analyzed a cohort of 331208 asymptomatic adults who underwent abdominal ultrasonography(US).The risk of GBP development was evaluated according to the obesity and NAFLD status.Results:The overall prevalence of NAFLD and GBPs≥5 mm was 28.5%and 2.9%,respectively.The prevalence of NAFLD among 160276 lean,77676 overweight and 93256 obese participants was 8.2%,31.2%,and 61.1%,respectively.Individuals with NAFLD had a significantly higher incidence of GBPs with a size of≥5 mm[adjusted odds ratio(OR)=1.18;95%confidence interval(CI):1.11–1.25].A higher body mass index and its categories were also significantly associated with an increased risk of GBPs≥5 mm.Moreover,risk of GBPs≥5 mm was significantly increased even in NAFLD individuals who are not obese(lean:adjusted OR=1.36,95%CI:1.19-1.54;overweight:adjusted OR=1.14,95%CI:1.03–1.26,respectively).Conclusions:Non-obese/lean NAFLD is an independent risk factor for GBP development,suggesting that NAFLD may play an important role in the pathogenesis of GBPs regardless of the obesity status.Therefore,a more thorough evaluation for GBPs may be necessary when hepatic steatosis is detected on abdominal US,even in non-obese or lean individuals.展开更多
The use of lithium-sulfur batteries under high sulfur loading and low electrolyte concentrations is severely restricted by the detrimental shuttling behavior of polysulfides and the sluggish kinetics in redox processe...The use of lithium-sulfur batteries under high sulfur loading and low electrolyte concentrations is severely restricted by the detrimental shuttling behavior of polysulfides and the sluggish kinetics in redox processes.Two-dimensional(2D)few layered black phosphorus with fully exposed atoms and high sulfur affinity can be potential lithium-sulfur battery electrocatalysts,which,however,have limitations of restricted catalytic activity and poor electrochemical/chemical stability.To resolve these issues,we developed a multifunctional metal-free catalyst by covalently bonding few layered black phosphorus nanosheets with nitrogen-doped carbon-coated multiwalled carbon nanotubes(denoted c-FBP-NC).The experimental characterizations and theoretical calculations show that the formed polarized P-N covalent bonds in c-FBP-NC can efficiently regulate electron transfer from NC to FBP and significantly promote the capture and catalysis of lithium polysulfides,thus alleviating the shuttle effect.Meanwhile,the robust 1D-2D interwoven structure with large surface area and high porosity allows strong physical confinement and fast mass transfer.Impressively,with c-FBP-NC as the sulfur host,the battery shows a high areal capacity of 7.69 mAh cm^(−2) under high sulfur loading of 8.74 mg cm^(−2) and a low electrolyte/sulfur ratio of 5.7μL mg^(−1).Moreover,the assembled pouch cell with sulfur loading of 4 mg cm^(−2) and an electrolyte/sulfur ratio of 3.5μL mg^(−1) shows good rate capability and outstanding cyclability.This work proposes an interfacial and electronic structure engineering strategy for fast and durable sulfur electrochemistry,demonstrating great potential in lithium-sulfur batteries.展开更多
As a prominent contributor to air pollution,nitric oxide(NO)has emerged as a critical agent causing detrimental environmental and health ramifications.To mitigate emissions and facilitate downstream utilization,adsorp...As a prominent contributor to air pollution,nitric oxide(NO)has emerged as a critical agent causing detrimental environmental and health ramifications.To mitigate emissions and facilitate downstream utilization,adsorption-based techniques offer a compelling approach for direct NO capture from both stationary and mobile sources.In this study,a comprehensive exploration of NO capture under oxygen-lean and oxygenrich conditions was conducted,employing Ni ion-exchanged chabazite(CHA-type)zeolites as the adsorbents.Remarkably,Ni/Na-CHA zeolites,with Ni loadings ranging from 3 to 4 wt%,demonstrate remarkable dynamic uptake capacities and exhibit exceptional NO capture efficiencies(NO-to-Ni ratio)for both oxygen-lean(0.17-0.31 mmol/g,0.32-0.43 of NO/Ni)and oxygen-rich(1.64-1.18 mmol/g)under ambient conditions.An NH3 reduction methodology was designed for the regeneration of absorbents at a relatively low temperature of 673 K.Comprehensive insights into the NO_(x) adsorption mechanism were obtained through temperature-programmed desorption experiments,in situ Fourier transform infrared spectroscopy,and density functional theory calculations.It is unveiled that NO and NO_(2) exhibit propensity to coordinate with Ni^(2+) via N-terminal or O-terminal,yielding thermally stable complexes and metastable species,respectively,while the low-temperature desorption substances are generated in close proximity to Na^(+).This study not only offers micro-level perspectives but imparts crucial insights for the advancement of capture and reduction technologies utilizing precious-metal-free materials.展开更多
文摘To investigate the effect of bowed/leaned vane configurations on the aerodynamic performance and aerodynamic excitation in transonic high-pressure turbine, the full three-dimensional viscous unsteady numerical simulation was performed by solving N-S equations based on SAS SST method.The influence of bowed/leaned vanes on turbine efficiency and efficiency fluctuation was investigated. The action of vane modelling to the overall aerodynamic fluctuation level and the amplitude of each vane passing frequency were analyzed. By comparing instantaneous pressure fluctuation contours in the blade passage with space-time maps, the link of the pressure fluctuation on blade surface with flow distortions was achieved, which can reveal the mechanism of the impact of the vane modelling. As the results suggest, the turbine efficiency is promoted with positively leaned and bowed vane modelling, and the fluctuation of stage turbine efficiency is repressed, which contributes to the smooth running of the turbine stage. The blade aerodynamic excitation on the rotor blade is characterized by the motion of vane trailing edge shock system, and the vane configurations can reduce the fluctuation level on the rotor blade surface effectively. For the positively leaned vane configuration, the aerodynamic excitations at the root and tip region are affected by the impact of the amplitude of the first harmonic, whereas they are reduced with the decrease of the amplitude of the second and higher harmonics at midspan. For the positively bowed vane, aerodynamic excitation is repressed by reducing the amplitude of the third harmonic at the root region, and the first harmonic at the tip region, and the amplitude of each harmonic is reduced at the middle region.
基金supported by the Research Grant Council of Hong Kong-Early Career Scheme(106210224)and the Seed Fund(104006024).
文摘Dear Editor,The Hans Chinese(HC)ethnic group,comprising approximately 1.4 billion individuals,represents the largest workforce globally.Historically,HC has been predominantly isolated from other ethnic groups for over 3 millennia,resulting in distinct genetic and physiological characteristics[1,2].Consequently,the energy required to maintain essential functions,represented by the basal metabolic rate(BMR),cannot be accurately assessed in HC with algorithms developed for European-American(EA)populations,even when controlling for diff erences in body size[3].Notably,the widely used Harris-Benedict equation tends to overestimate BMR,relative to measured BMR via indirect calorimetry,in more than 50%of HC individuals[3].Hence,HC generally expends less energy than EA under basal(resting)conditions.This raises an important question:does HC require lower energy expenditure than EA for equivalent external work?Th e present aimed to address this inquiry,while adjusting for key confounding factors such as age,sex,physical activity,aerobic capacity,BMR,and body composition.
基金supported by the Research Funding of Hangzhou International Innovation Institute of Beihang University(Grant No.2024KQ102 and 2024KQ131)the National Natural Science Foundation of China(Grant No.524B2020,51925202,U22A20141,52432004,U23A20575,52472183,and 22379039).
文摘Lithium-sulfur batteries(LSBs)hold significant promise as advanced energy storage systems due to their high energy density,low cost,and environmental advantages.However,despite recent advancements,their practical energy density still falls short of the levels required for commercial viability.The energy density is critically dependent on both sulfur loading and the amount of electrolyte used.Highsulfur loading coupled with lean electrolyte conditions presents several challenges,including the insulating nature of sulfur and Li_(2)S,insufficient electrolyte absorption,degradation of the cathode structure,severe lithium polysulfide shuttling,slow redox reaction kinetics,and instability of the Li metal anode.MXenes-based materials,with their metallic conductivity,large polar surfaces,and abundant active sites,have been identified as promising electrocatalysts to improve the redox reactions in LSBs.This review focuses on the significance and challenges associated with high-sulfur loading and lean electrolytes in LSBs,highlighting recent advancements in MXenes-based electrocatalysts aimed at optimizing sulfur cathodes and lithium anodes.It provides a comprehensive discussion on MXenes as both active materials and substrates in LSBs,with the goal of enhancing understanding of the regulatory mechanisms that govern sulfur conversion reactions and lithium plating/stripping behavior.Finally,the review explores future opportunities for MXenes-based electrocatalysts,paving the way for the practical application of LSBs.
基金supported by the Jilin Scientific and Technological Development Program(No.YDZJ202201ZYTS669)the National Natural Science Foundation of China(Nos.51974032,52174355,51874043 and 51604034).
文摘Over the past few years,the Cu element has attracted much attention in duplex stainless steels.It undoubtedly holds advantageous in regulating the two-phase proportion and austenite stability and is also one of the crucial factors affecting the corrosion resistance.However,the systematic research on the impact of Cu addition to lean duplex stainless steels remains insufficient.In this study,a novel Cu-alloyed Mn-N-type 20Cr lean duplex stainless steel was developed and the effect of Cu on the strain hardening capacity and corrosion resistance was analyzed.The results show that the Cu addition increases the volume fraction and stability of the austenite,retards the martensitic transformation,and extends the transformation-induced plasticity effect to a wider strain range.Compared to the Cu-free steel,the plasticity of Cu-containing steel can be increased by~26%.Additionally,the addition of Cu redistributes the Cr and N elements in the ferrite and austenite phases,thereby improving the corrosion resistance of the lean duplex stainless steel.
文摘Objective:To evaluate the application value of lean management in the management of flexible endoscopes.Methods:From January to December 2023,routine management was implemented,and 200 flexible endoscopes used for examination and treatment were included in the control group;from January to December 2024,lean management was implemented,and 200 flexible endoscopes used for examination and treatment were included in the observation group.The average daily usage frequency,management effectiveness,and failure rate of flexible endoscopes were compared between the two groups.Results:The average daily usage frequency of flexible endoscopes in the observation group was higher than that in the control group(P<0.05);the 3S retrieval rate and spot-check qualification rate of endoscopes in the observation group were higher than those in the control group(P<0.05);the failure rate of flexible endoscopes in the observation group was lower than that in the control group(P<0.05).Conclusion:Implementing lean management during the management of flexible endoscopes can improve the efficiency of endoscope retrieval,increase the average daily usage frequency of flexible endoscopes,and reduce endoscope failures.
基金the financial support of the National Natural Science Foundation of China(Nos.U2141221 and 52076136)the National Science and Technology Major Project,China(Nos.J2019-Ⅲ-0004-0047 and Y2022-Ⅲ-0001-0010)+1 种基金the Center for Basic Science of Aero Engines and Gas Turbines Project,China(No.P2022-B-Ⅱ019-001)the Natural Science Foundation of Shanghai,China(Nos.22ZR1467900 and 23ZR1481400)。
文摘This study systematically investigated the Lean Blowoff(LBO)limits of Two-Dimensional(2D)bluff-body stabilized premixed flames by varying the air mass flow rate,inflowtemperature,bluff-body width,and fuel type.The data of LBO limits were analyzed and fittedaccording to the Damk?hler(Da)and Reynolds(Re)numbers,and the fitting accuracy of LBO datawas highly improved by a modified characteristic length simultaneously considering the length andwidth of the bluff body,which is usually neglected in the previous studies.Moreover,to our knowl-edge,this is the first time that simultaneous transverse and spanwise OH*-Chemiluminescence(CL)imaging has been performed to examine the three-dimensional behavior of the LBO process.The flame stability is heavily affected by the mass and energy transport between reactants andproducts in both directions,potentially leading to the flame pinch-off.The intensity and positionof the upstream flame after pinch-off are decisive to the occurrence of the following LBO.Whenthe upstream flame after pinch-off is weak and close to the bluff body,it cannot re-ignite thedownstream unburnt gas.Subsequently,a permanent downstream extinction occurs,and theLBO takes place.The results help understand the LBO mechanism of 2D bluff-body stabilizedflames.
文摘The prevalence of metabolic-associated fatty liver disease(MAFLD)has increased substantially in recent years because of the global obesity pandemic.MAFLD,now recognized as the number one cause of chronic liver disease in the world,not only increases liver-related morbidity and mortality among sufferers but also worsens the complications associated with other comorbid conditions such as cardiovascular disease,type 2 diabetes mellitus,obstructive sleep apnoea,lipid disorders and sarcopenia.Understanding the interplay between MAFLD and these comorbidities is important to design optimal therapeutic strategies.Sarcopenia can be either part of the disease process that results in MAFLD(e.g.,obesity or adiposity)or a consequence of MAFLD,especially in the advanced stages such as fibrosis and cirrhosis.Sarcopenia can also worsen MAFLD by reducing exercise capacity and by the production of various muscle-related chemical factors.Therefore,it is crucial to thoroughly understand how we deal with these diseases,especially when they coexist.We explore the pathobiological interlinks between MAFLD and sarcopenia in this comprehensive clinical update review article and propose evidence-based therapeutic strategies to enhance patient care.
基金support by the Spanish Ministry of Science and Innovation(Ref:PID2020-117302RA-I00)La Caixa Foundation(Ref:LCF/BQ/PR19/11700007)+3 种基金the University of Granada Plan Propio de Investigación 2021-Excellence actions:Unit of Excellence on Exercise,Nutrition,and Health(UCEENS)and by CIBEROBN,Centro de Investigación Biomédica en Red(CB22/3/00058)Instituto de Salud Carlos III,Ministerio de Ciencia e Innovación and Unión Europea-European Regional Development FundAMP was also recipient of a predoctoral fellowship(FPU20/05530)by the Spanish Ministry of Education,Culture and SportEUG was supported by the Maria Zambrano fellowship by the Ministerio de Universidades y la Unión Europea-NextGenerationEU.
文摘Background Pediatric cancer survivors are at increased risk of muscle weakness and low areal bone mineral density(aBMD).However,the prevalence of muscle strength deficits is not well documented,and the associations of muscle strength with aBMD are unknown in this population.Therefore,this study aimed to investigate the prevalence of upper-and lower-body muscle strength deficits and to examine the associations of upper-and lower-body muscle strength with age-,sex,and race-specific aBMD Z-scores at the total body,total hip,femoral neck,and lumbar spine.Methods This cross-sectional study included 116 pediatric cancer survivors(12.1±3.3 years old,mean±SD;42.2%female).Upper-and lower-body muscle strength were assessed by handgrip and standing long jump test,respectively.Dual‑energy X‑ray absorptiometry was used to measure aBMD(g/cm2).Associations between muscle strength and aBMD were evaluated in multivariable linear regression models.Logistic regression was used to evaluate the contribution of muscle strength(1-decile lower)to the odds of having low aBMD(Z-score≤1.0).All analyses were adjusted for time from treatment completion,radiotherapy exposure,and body mass index.Results More than one-half of survivors were within the 2 lowest deciles for upper-(56.9%)and lower-body muscle strength(60.0%)in comparison to age-and sex-specific reference values.Muscle strength deficits were associated with lower aBMD Z-scores at all sites(B=0.133–0.258,p=0.001–0.032).Each 1-decile lower in upper-body muscle strength was associated with 30%–95%higher odds of having low aBMD Z-scores at all sites.Each 1-decile lower in lower-body muscle strength was associated with 35%–70%higher odds of having low aBMD Z-scores at total body,total hip,and femoral neck.Conclusion Muscle strength deficits are prevalent in young pediatric cancer survivors,and such deficits are associated with lower aBMD Z-scores at all sites.These results suggest that interventions designed to improve muscle strength in this vulnerable population may have the added benefit of improving aBMD.
基金supported by the Jilin Scientific and Technological Development Program(No.YDZJ202201ZYTS669)the National Natural Science Foundation of China(Nos.51974032,52174355,51874043 and 51604034).
文摘Proper matching of cold-rolled deformation and low-temperature short-term aging can simultaneously enhance the strength and ductility of the lean duplex stainless steel. To investigate this, the microstructure evolution of cold-rolled and aging steels was observed by using scanning electron microscopy, transmission electron microscopy and electron backscattered diffraction. Additionally, the phase volume fraction was measured using X-ray diffraction. In this study, it was observed that the elongation of 21Cr lean duplex stainless steel significantly increased to 16.7% after undergoing moderate cold deformation (~ 40% reduction) and subsequent aging treatment at 550 ℃ for 30 min. Remarkably, the material still maintained a high yield strength of 1045 MPa. Such an excellent mechanical property was attributed to a unique microstructure combination of fine α'-martensite, twins, coarsened austenite resulting from partial martensite reverse transformation, and two-phase fine layered structure. The result of this study may open up new horizons for the alloy development in order to overcome the low ductility of cold-rolled high-strength lean duplex stainless steel.
基金the financial support for this work from the National Natural Science Foundation of China(Nos.52171241,52201301 and 51871166)。
文摘The effects of nano-CaO contents on the microstructure,mechanical properties and corrosion resistance of lean Mg-1Zn alloy were investigated.The results showed that the addition of nano-CaO significantly refined the grain size and improved mechanical properties of the Mg-1Zn alloy.At the same time,CaO reacted with molten Mg in situ to form nano-MgO,whose corrosion product in SBF solution was the same with the degradation product of Mg matrix,resulting in the enhanced compactness of the Mg(OH)_(2) layer and reduced corrosion rate of matrix.The Mg-1Zn alloy had lower corrosion resistance due to excessively large grain size and shedding of corrosion products.The composite with 0.5 wt.%CaO had the best corrosion resistance with a weight loss of 9.875 mg·y^(-1)·mm^(-2)due to the small number of Ca_(2)Mg_(6)Zn_(3) phase and suitable grain size.While for composites with high content of CaO(0.7 wt.%and 1.0 wt.%),they had lower corrosion resistance due to the coexistence of large number of Ca_(2)Mg_(6)Zn_(3) and Mg_(2)Ca at grain boundaries,especially for 1.0 wt.%CaO composite,resulting from the strong micro-galvanic corrosion.
基金supported by the Natural Science Foundation of Sichuan Province of China,Nos.2022NSFSC1545 (to YG),2022NSFSC1387 (to ZF)the Natural Science Foundation of Chongqing of China,Nos.CSTB2022NSCQ-LZX0038,cstc2021ycjh-bgzxm0035 (both to XT)+3 种基金the National Natural Science Foundation of China,No.82001378 (to XT)the Joint Project of Chongqing Health Commission and Science and Technology Bureau,No.2023QNXM009 (to XT)the Science and Technology Research Program of Chongqing Education Commission of China,No.KJQN202200435 (to XT)the Chongqing Talents:Exceptional Young Talents Project,No.CQYC202005014 (to XT)。
文摘Epilepsy can be defined as a dysfunction of the brain network,and each type of epilepsy involves different brain-network changes that are implicated diffe rently in the control and propagation of interictal or ictal discharges.Gaining more detailed information on brain network alterations can help us to further understand the mechanisms of epilepsy and pave the way for brain network-based precise therapeutic approaches in clinical practice.An increasing number of advanced neuroimaging techniques and electrophysiological techniques such as diffusion tensor imaging-based fiber tra ctography,diffusion kurtosis imaging-based fiber tractography,fiber ball imagingbased tra ctography,electroencephalography,functional magnetic resonance imaging,magnetoencephalography,positron emission tomography,molecular imaging,and functional ultrasound imaging have been extensively used to delineate epileptic networks.In this review,we summarize the relevant neuroimaging and neuroelectrophysiological techniques for assessing structural and functional brain networks in patients with epilepsy,and extensively analyze the imaging mechanisms,advantages,limitations,and clinical application ranges of each technique.A greater focus on emerging advanced technologies,new data analysis software,a combination of multiple techniques,and the construction of personalized virtual epilepsy models can provide a theoretical basis to better understand the brain network mechanisms of epilepsy and make surgical decisions.
文摘BACKGROUND A new nomenclature consensus has emerged for liver diseases that were previously known as non-alcoholic fatty liver disease(NAFLD)and metabolic dysfunction-associated fatty liver disease(MAFLD).They are now defined as metabolic dysfunction-associated steatotic liver disease(MASLD),which includes cardiometabolic criteria in adults.This condition,extensively studied in obese or overweight patients,constitutes around 30%of the population,with a steady increase worldwide.Lean patients account for approximately 10%-15%of the MASLD population.However,the pathogenesis is complex and is not well understood.AIM To systematically review the literature on the diagnosis,pathogenesis,characteristics,and prognosis in lean MASLD patients and provide an interpretation of these new criteria.METHODS We conducted a comprehensive database search on PubMed and Google Scholar between January 2012 and September 2023,specifically focusing on lean NAFLD,MAFLD,or MASLD patients.We include original articles with patients aged 18 years or older,with a lean body mass index categorized according to the World Health Organization criteria,using a cutoff of 25 kg/m2 for the general population and 23 kg/m2 for the Asian population.RESULTS We include 85 studies in our analysis.Our findings revealed that,for lean NAFLD patients,the prevalence rate varied widely,ranging from 3.8%to 34.1%.The precise pathogenesis mechanism remained elusive,with associations found in genetic variants,epigenetic modifications,and adaptative metabolic response.Common risk factors included metabolic syndrome,hypertension,and type 2 diabetes mellitus,but their prevalence varied based on the comparison group involving lean patients.Regarding non-invasive tools,Fibrosis-4 index outperformed the NAFLD fibrosis score in lean patients.Lifestyle modifications aided in reducing hepatic steatosis and improving cardiometabolic profiles,with some medications showing efficacy to a lesser extent.However,lean NAFLD patients exhibited a worse prognosis compared to the obese or overweight counterpart.CONCLUSION MASLD is a complex disease comprising epigenetic,genetic,and metabolic factors in its pathogenesis.Results vary across populations,gender,and age.Limited data exists on clinical practice guidelines for lean patients.Future studies employing this new nomenclature can contribute to standardizing and generalizing results among lean patients with steatotic liver disease.
基金supported by the National Research Foundation of Korea (NRF)grant funded by the Korean government (MSIT) (NRF-2022R1C1C1011058)supported by the Korea Institute for Advancement of Technology (KIAT)grant funded by the Korean Government (MOTIE) (P0012748,HRD Program for Industrial Innovation).
文摘Batteries that utilize low-cost elemental sulfur and light metallic lithium as electrodes have great potential in achieving high energy density.However,building a lithium-sulfur(Li-S)full battery by controlling the electrolyte volume generally produces low practical energy because of the limited electrochemical Li-S redox.Herein,the high energy/high performance of a Li-S full battery with practical sulfur loading and minimum electrolyte volume is reported.A unique hybrid architecture configured with Ni-Co metal alloy(NiCo)and metal oxide(NiCoO_(2))nanoparticles heterogeneously anchored in carbon nanotube-embedded selfstanding carbon matrix is fabricated as a host for sulfur.This work demonstrates the considerable improvement that the hybrid structure's high conductivity and satisfactory porosity promote the transport of electrons and lithium ions in Li-S batteries.Through experimental and theoretical validations,the function of NiCo and NiCoO_(2) nanoparticles as an efficient polysulfide mediator is established.These particles afford polysulfide anchoring and catalytic sites for Li-S redox reaction,thus improving the redox conversion reversibility.Even at high sulfur loading,the nanostructured Ni-Co metal alloy and metal oxide enable to have stable cycling performance under lean electrolyte conditions both in half-cell and full-cell batteries using a graphite anode.
文摘Confucius said,“To know what you know and what you do not know, that is true knowledge.”Hartemink (2006) edited a prescient book on the future of soil science, the contents of which are worthy of consideration today. Since then, there has been a growing emphasis on soil carbon, soil health, and soil security, as well as increased capability of technology related to machine leaning and soil sensing and measurement.SOIL KNOWLEDGE DISCOVERY CATEGORISATION Based on the above ancient aphorism attributed to Confucius, the author writing in Hartemink (2006) classified soil knowledge and knowledge discovery into 4 categories. An updated version is given in Fig. 1.
基金financially supported by the National Natural Science Foundation of China(Nos.52122308 and 52102318)Fellowship of China Postdoctoral Science Foundation(Nos.2021TQ0287 and 2022M722855)。
文摘The practical energy density of lithium-sulfur batteries(LSBs)is seriously limited by the high electrolyte-to-sulfur ratios(E/S).The E/S can be reduced by employing hosts with easy-to-infiltrate structure that ensures the uniform distribution of a lean electrolyte and high catalytic activity that can suppress"shuttle effect"via accelerating the slow conversion of soluble poly sulfides to insoluble sulfides.Among the easy-to-infiltrate structures,the three-dimensional-ordered macroporous(3DOM)structure is easier to scale preparation and more suitable for the existing industrial processes.However,it is difficult to obtain the 3DOM with(1)high penetrability due to the high viscosity of frequently-used organic polymer precursors and(2)high catalytic activity due to the low confinement effect,meaning that uniformly dispersed small-sized catalytic materials are difficult to load on 3DOM.Herein,using carbon dots(CDs)with both organic and inorganic properties as a precursor and aggregation limiting agent,a 3DOM host with high penetrability and homodispersed Ni particles of small sizes(Ni-CDs-3DOM)was synthesized.In this host:(1)CDs precursor with suitable viscosity can improve the penetrability.(2)CDs can effectively inhibit the agglomeration of Ni particles.(3)Uniformly dispersed small-size Ni particles offer high-efficiency catalytic activity toward sulfur reactions.Consequently,the Ni-CDs-3DOM/sulfur cathode exhibits high sulfur utilization and stable cycling performance even under high sulfur loading(5.5 mg·cm^(-2))and low E/S(6.5μl·mg^(-1)).This work indicates the usefulness of CDs in constructing hosts for LSBs with high energy density.
文摘Background:The association between non-obese or lean nonalcoholic fatty liver disease(NAFLD)and gallbladder polyps(GBPs)has not yet been evaluated.We aimed to determine whether NAFLD is an independent risk factor for the development of GBPs,even in non-obese and lean individuals.Methods:We analyzed a cohort of 331208 asymptomatic adults who underwent abdominal ultrasonography(US).The risk of GBP development was evaluated according to the obesity and NAFLD status.Results:The overall prevalence of NAFLD and GBPs≥5 mm was 28.5%and 2.9%,respectively.The prevalence of NAFLD among 160276 lean,77676 overweight and 93256 obese participants was 8.2%,31.2%,and 61.1%,respectively.Individuals with NAFLD had a significantly higher incidence of GBPs with a size of≥5 mm[adjusted odds ratio(OR)=1.18;95%confidence interval(CI):1.11–1.25].A higher body mass index and its categories were also significantly associated with an increased risk of GBPs≥5 mm.Moreover,risk of GBPs≥5 mm was significantly increased even in NAFLD individuals who are not obese(lean:adjusted OR=1.36,95%CI:1.19-1.54;overweight:adjusted OR=1.14,95%CI:1.03–1.26,respectively).Conclusions:Non-obese/lean NAFLD is an independent risk factor for GBP development,suggesting that NAFLD may play an important role in the pathogenesis of GBPs regardless of the obesity status.Therefore,a more thorough evaluation for GBPs may be necessary when hepatic steatosis is detected on abdominal US,even in non-obese or lean individuals.
基金Jiangsu Provincial Department of Science and Technology,Grant/Award Number:BK20201190Fundamental Research Funds for“Young Talent Support Plan”of Xi'an Jiaotong University,Grant/Award Number:HG6J003+1 种基金“1000-Plan program”of Shaanxi Province and the Velux Foundations through the research center V-Sustain,Grant/Award Number:9455National Key R&D Program of China,。
文摘The use of lithium-sulfur batteries under high sulfur loading and low electrolyte concentrations is severely restricted by the detrimental shuttling behavior of polysulfides and the sluggish kinetics in redox processes.Two-dimensional(2D)few layered black phosphorus with fully exposed atoms and high sulfur affinity can be potential lithium-sulfur battery electrocatalysts,which,however,have limitations of restricted catalytic activity and poor electrochemical/chemical stability.To resolve these issues,we developed a multifunctional metal-free catalyst by covalently bonding few layered black phosphorus nanosheets with nitrogen-doped carbon-coated multiwalled carbon nanotubes(denoted c-FBP-NC).The experimental characterizations and theoretical calculations show that the formed polarized P-N covalent bonds in c-FBP-NC can efficiently regulate electron transfer from NC to FBP and significantly promote the capture and catalysis of lithium polysulfides,thus alleviating the shuttle effect.Meanwhile,the robust 1D-2D interwoven structure with large surface area and high porosity allows strong physical confinement and fast mass transfer.Impressively,with c-FBP-NC as the sulfur host,the battery shows a high areal capacity of 7.69 mAh cm^(−2) under high sulfur loading of 8.74 mg cm^(−2) and a low electrolyte/sulfur ratio of 5.7μL mg^(−1).Moreover,the assembled pouch cell with sulfur loading of 4 mg cm^(−2) and an electrolyte/sulfur ratio of 3.5μL mg^(−1) shows good rate capability and outstanding cyclability.This work proposes an interfacial and electronic structure engineering strategy for fast and durable sulfur electrochemistry,demonstrating great potential in lithium-sulfur batteries.
基金supported by the National Natural Science Foundation of China(22302100,22025203,22121005)the Fundamental Research Funds for the Central Universities(Nankai University).
文摘As a prominent contributor to air pollution,nitric oxide(NO)has emerged as a critical agent causing detrimental environmental and health ramifications.To mitigate emissions and facilitate downstream utilization,adsorption-based techniques offer a compelling approach for direct NO capture from both stationary and mobile sources.In this study,a comprehensive exploration of NO capture under oxygen-lean and oxygenrich conditions was conducted,employing Ni ion-exchanged chabazite(CHA-type)zeolites as the adsorbents.Remarkably,Ni/Na-CHA zeolites,with Ni loadings ranging from 3 to 4 wt%,demonstrate remarkable dynamic uptake capacities and exhibit exceptional NO capture efficiencies(NO-to-Ni ratio)for both oxygen-lean(0.17-0.31 mmol/g,0.32-0.43 of NO/Ni)and oxygen-rich(1.64-1.18 mmol/g)under ambient conditions.An NH3 reduction methodology was designed for the regeneration of absorbents at a relatively low temperature of 673 K.Comprehensive insights into the NO_(x) adsorption mechanism were obtained through temperature-programmed desorption experiments,in situ Fourier transform infrared spectroscopy,and density functional theory calculations.It is unveiled that NO and NO_(2) exhibit propensity to coordinate with Ni^(2+) via N-terminal or O-terminal,yielding thermally stable complexes and metastable species,respectively,while the low-temperature desorption substances are generated in close proximity to Na^(+).This study not only offers micro-level perspectives but imparts crucial insights for the advancement of capture and reduction technologies utilizing precious-metal-free materials.
