To synergistically recover alumina and alkali from red mud(RM),the structural stability and conversion mechanism of hydroandradite(HA)from hydrogarnet(HG)were investigated via the First-principles,XRF,XRD,PSD and SEM ...To synergistically recover alumina and alkali from red mud(RM),the structural stability and conversion mechanism of hydroandradite(HA)from hydrogarnet(HG)were investigated via the First-principles,XRF,XRD,PSD and SEM methods,and a novel hydrothermal process based on the conversion principle was finally proposed.The crystal structure simulation shows that the HA with varied silicon saturation coefficients is more stable than HG,and the HA with a high iron substitution coefficient is more difficult to be converted from HG.The(110)plane of Fe_(2)O_(3) is easier to combine with HG to form HA,and the binding energy is 81.93 kJ/mol.The effects of raw material ratio,solution concentration and hydrothermal parameters on the conversion from HG to HA were revealed,and the optimal conditions for the alumina recovery were obtained.The recovery efficiencies of alumina and Na_(2)O from the RM are 63.06%and 97.34%,respectively,and the Na_(2)O content in the treated RM is only 0.13%.展开更多
Hydrogen peroxide(H_(2)O_(2)) has been recognized as a green and nonpolluting multifunctional oxidant with extensive applications in environmental protection,metal etching,textile printing and dyeing,chemical synthesi...Hydrogen peroxide(H_(2)O_(2)) has been recognized as a green and nonpolluting multifunctional oxidant with extensive applications in environmental protection,metal etching,textile printing and dyeing,chemical synthesis and food processing.However,over 90 % of industrial H_(2)O_(2) is currently produced through the multi-step anthraquinone oxidation process,which suffers from a process with some drawbacks such as complex,high-energy consumption,and toxic byproducts emissions.Compared to the traditional anthraquinone method,artificial photosynthesis of H_(2)O_(2) using semiconductor photocatalysts has emerged as a sustainable alternative due to its use of water and O_(2) as the clean reactants and sole energy as the driving force.In recent years,metal-free photocatalysts mainly including covalent organic frameworks(COFs),covalent triazine frameworks(CTFs) and carbon nitrile(g-C_(3)N_(4)) have garnered significant interest due to their superior thermal and chemical stability,diverse synthesis methods,tunable functionality,light weight nature and non-toxicity.These materials also exhibit adjustable band structure and unique photoelectric properties.Sustainable efforts have been made to advance metal-free photocatalysts for artificial photosynthesis of H_(2)O_(2),however,a comprehensive summary of current research status on metalfree-based photocatalytic overall H_(2)O_(2) production remain scarce.This review outlines recent process in overall H_(2)O_(2) photosynthesis based on metal-free photocatalysts.First,we introduced the fundamental concepts of photocatalytic overall H_(2)O_(2) production.Then,we analyze representative studies on photocatalytic overall H_(2)O_(2) synthesis using metal-free materials.Finally,we discuss the challenges and future perspectives in this field to guide the design and synthesis of metal-free systems for H_(2)O_(2) generation.展开更多
Introducing Ti_(2)AlC particles into TiAl alloys can effectively improve their strength,but this can also lead to stress concentration at the interface,resulting in the reduction of ductility.Therefore,Mn is adopted t...Introducing Ti_(2)AlC particles into TiAl alloys can effectively improve their strength,but this can also lead to stress concentration at the interface,resulting in the reduction of ductility.Therefore,Mn is adopted to synergistically improve the strength and ductility of the Ti_(2)AlC/TiAl composite through solid solution and interface manipulation.The first-principles calculation shows the Ti-Mn bonds are formed at the Ti_(2)AlC/TiAl interface after Mn doping,characterized primarily by metallic bonds with some covalent bonding.This combination preserves strength while enhancing ductility.Then,Ti_(2)AlC/TiAl-Mn composite is prepared.The Ti_(2)AlC,with an average size of 1.6μm,is uniformly distributed within the TiAl matrix.Mn doping reduces the lamellar colony size and lamellar thickness by 25.1%and 27.4%,respectively.A small quantity of Mn accumulates at the boundaries of the lamellar colonies.The Mn content must be controlled to avoid segregation,which may negatively impact performance.The yield stress,ultimate compressive stress,fracture strain,and product of strength and plasticity of the Ti_(2)AlC/TiAl-Mn composite have been increased by 5.5%,11.5%,10.4%,and 23.0%,respectively,compared to those of the Ti_(2)AlC/TiAl composite.The enhancement in strength is due to the combined effects of grain refinement,solid solution of Mn,and twining strengthening.Grain refinement and twin strengthening also can reduce stress concentration and improve ductility.In addition,at the electronic level,the Ti-Mn bond formed at the interface is contributed to the improvement of ductility.展开更多
Electrocatalytic conversion of renewable biomass is emerging as a promising route for sustainable chemical production;hence it urgently calls for developing efficient electrocatalysts with low potentials and high curr...Electrocatalytic conversion of renewable biomass is emerging as a promising route for sustainable chemical production;hence it urgently calls for developing efficient electrocatalysts with low potentials and high current densities.Herein,a Pr-doped Co(OH)_(2)hexagonal sheet(Pr/Co=1/9,in mole)is synthesized by electrodeposition as highly performant catalyst for 5-hydroxymethylfurfural(HMF)oxidation reaction(HMFOR)to produce 2,5-furandicarboxylic acid(FDCA).This novel and low-cost catalyst possesses a rather low onset potential of 1.05 V(vs.RHE)and requires only 1.10 V(vs.RHE)to reach a current density of 10 mA cm^(-2)for HMFOR,significantly outperforming Co(OH)_(2)benchmark(i.e.,210 mV higher to reach10 m A cm^(-2)).The origin of Pr promotion effect as well as the evolution of CoOOH catalytic sites and HMFOR process has been deeply elucidated by physical characterizations,kinetic experiments,in situ electrochemical techniques,and theoretical calculations.The unique Pr-ameliorated CoOOH active centers enable 100%conversion of HMF,99.6%selectivity of FDCA,and 99.7%Faraday efficiency,with a superior cycling durability toward HMFOR.This can be one of the most outstanding results for Co-based HMFOR catalysts to date in the literature.Thereby this work can help open up new horizons for constructing novel and efficient Co-based electrocatalysts by the utilization of lanthanide elements.展开更多
Superconducting radio-frequency(SRF)cavities are the core components of SRF linear accelerators,making their stable operation considerably important.However,the operational experience from different accelerator labora...Superconducting radio-frequency(SRF)cavities are the core components of SRF linear accelerators,making their stable operation considerably important.However,the operational experience from different accelerator laboratories has revealed that SRF faults are the leading cause of short machine downtime trips.When a cavity fault occurs,system experts analyze the time-series data recorded by low-level RF systems and identify the fault type.However,this requires expertise and intuition,posing a major challenge for control-room operators.Here,we propose an expert feature-based machine learning model for automating SRF cavity fault recognition.The main challenge in converting the"expert reasoning"process for SRF faults into a"model inference"process lies in feature extraction,which is attributed to the associated multidimensional and complex time-series waveforms.Existing autoregression-based feature-extraction methods require the signal to be stable and autocorrelated,resulting in difficulty in capturing the abrupt features that exist in several SRF failure patterns.To address these issues,we introduce expertise into the classification model through reasonable feature engineering.We demonstrate the feasibility of this method using the SRF cavity of the China accelerator facility for superheavy elements(CAFE2).Although specific faults in SRF cavities may vary across different accelerators,similarities exist in the RF signals.Therefore,this study provides valuable guidance for fault analysis of the entire SRF community.展开更多
Growth of high-quality Nb_(3)Sn thin films for superconducting radiofrequency(SRF)applications using the vapor diffusion method requires a uniform distribution of tin nuclei on the niobium(Nb)surface.This study examin...Growth of high-quality Nb_(3)Sn thin films for superconducting radiofrequency(SRF)applications using the vapor diffusion method requires a uniform distribution of tin nuclei on the niobium(Nb)surface.This study examines the mechanism underlying the observed non-uniform distribution of tin nuclei with tin chloride SnCl_(2).Electron backscatter diffraction(EBSD)analysis was used to examine the correlation between the nucleation behavior and orientation of niobium grains in the substrate.The findings of the density functional theory(DFT)simulation are in good agreement with the experimental results,showing that the non-uniform distribution of tin nuclei is the result of the adsorption energy of SnCl_(2)molecules by varied niobium grain orientations.Further analysis indicated that the surface roughness and grain size of niobium also played significant roles in the nucleation behavior.This study provides valuable insights into enhancing the surface pretreatment of niobium substrates during the growth of Nb_(3)Sn thin films using the vapor diffusion method.展开更多
BACKGROUND Pyogenic liver abscess(PLA)is a prevalent liver infection with gradual onset and severe symptoms,including fever,abdominal pain,jaundice,and vomiting.Complications like sepsis or toxic shock can also occur....BACKGROUND Pyogenic liver abscess(PLA)is a prevalent liver infection with gradual onset and severe symptoms,including fever,abdominal pain,jaundice,and vomiting.Complications like sepsis or toxic shock can also occur.AIM To investigate the clinical value of early ultrasound-guided percutaneous drainage(PCD)in PLA patients,specifically those with non-liquefied abscesses,and evaluate the feasibility of early intervention.METHODS This retrospective analysis included 143 patients with PLA who were admitted to the Department of General Surgery between January 2018 and March 2023.All patients underwent ultrasound-guided PCD.Based on the liquefaction status of the abscess,patients were divided into two groups:Liquefied group and nonliquefied group.Clinical outcomes,including puncture success rate,puncture duration,length of hospital stay,time to fever resolution,abscess shrinkage rate,and complication rates,were compared between the two groups.RESULTS The puncture success rate for all patients was 99.3%,with a postoperative complication rate of 5.59%,and no intraoperative deaths occurred.Compared to the liquefied group,the non-liquefied group had significantly shorter hospital stays(3.9±1.8 days vs 5.1±2.7 days),faster fever resolution(2.4±1.1 days vs 4.9±2.2 days),and quicker abscess shrinkage(>50%)(4.7±1.5 days vs 8.6±3.3 days)(P<0.05).There were no significant differences in puncture success rates or complication rates between the two groups.CONCLUSION Early ultrasound-guided PCD can be safely and effectively performed in PLA,even when the abscess is not fully liquefied or is non-liquefied,supporting the clinical feasibility of early intervention.展开更多
In continuation of research aimed at identifying anti-inflammatory agents from natural sesquiterpenoids,an activity-guided fractionation approach utilizing lipopolysaccharide(LPS)-mediated RAW264.7 cells was employed ...In continuation of research aimed at identifying anti-inflammatory agents from natural sesquiterpenoids,an activity-guided fractionation approach utilizing lipopolysaccharide(LPS)-mediated RAW264.7 cells was employed to investigate chemical constituents from Inula Britannica(I.britannica).Seven novel sesquiterpenoid dimers inulabritanoids A−G(1−7)and two novel sesquiterpenoid monomers inulabritanoids H(8)and I(9)were isolated from I.britannica together with eighteen known compounds(10−27).The structural elucidation was accomplished through comprehensive analysis of 1D and 2D nuclear magnetic resonance(NMR),high-resolution mass spectrometry(HR-MS),and electronic circular dichroism(ECD)spectra,complemented by quantum chemical calculations.Compounds 1,2,12,16,19,and 26 demonstrated inhibitory effects on NO production,with IC50 values of 3.65,5.48,3.29,6.91,3.12,and 5.67μmol·L^(−1),respectively.Mechanistic studies revealed that compound 1 inhibited IκB kinaseβ(IKKβ)phosphorylation,thereby blocking nuclear factorκB(NF-κB)nuclear translocation,and activated the kelch-like ECH-associated protein 1(Keap1)/nuclear factor erythroid 2-related factor 2(Nrf2)signal pathway,leading to decreased expression of NADPH oxidase 2(NOX-2),inducible nitric oxide synthase(iNOS),tumor necrosis factorα(TNF-α),interleukin-6(IL-6),monocyte chemotactic protein-1(MCP-1),IL-1β,and IL-1αand increased expression of NAD(P)H:quinone oxidoreductase 1(NQO-1)and heme oxygenase-1(HO-1),thus exhibiting anti-inflammatory effects in vitro.These results indicate that dimeric sesquiterpenoids may serve as promising candidates for anti-inflammatory drug development.展开更多
2,2',7,7'-Tetrakis(N,N-di(4-methoxyphenyl)amino)-9,9'-spirobifluorene(Spiro)is an essential hole-transport material used in perovskite solar cells(PSCs).However,the redox reaction of Spiro and its impact a...2,2',7,7'-Tetrakis(N,N-di(4-methoxyphenyl)amino)-9,9'-spirobifluorene(Spiro)is an essential hole-transport material used in perovskite solar cells(PSCs).However,the redox reaction of Spiro and its impact at the interface with the metal electrode are not yet fully understood.In this study,we introduced a crystalline additive(CA)to regulate the redox process of Spiro and its interface with an Ag electrode.Our findings indicate that CA functions as a molecular scaffold,improving the crystallinity and stability of radicals in Spiro throughout the entire redox reaction.This enhancement increases the hole mobility of Spiro and strengthens the internal electric field,thereby improving hole extraction and transport efficiency at both interfaces.Moreover,the optimized redox reaction of Spiro reduces energy loss at the Ag electrode,significantly boosting the power conversion efficiency to 25.21%.Furthermore,CA mitigates the aggregation of lithium salt and enhances the stability of the device.Our findings contribute to a deeper understanding of hole-transport mechanisms of Spiro and emphasize the importance of reducing energy loss at the Spiro/Ag electrode interface in PSCs.展开更多
As the demand for computing power in data centers continues to grow, balancing data transmitting speed and energy efficiency has emerged as a critical challenge. Highbandwidth, low-power interconnection schemes are in...As the demand for computing power in data centers continues to grow, balancing data transmitting speed and energy efficiency has emerged as a critical challenge. Highbandwidth, low-power interconnection schemes are increasingly recognized as core requirements for next-generation intelligent computing center designs^([1, 2]). For short-range optical interconnections of intra-chip and inter-chip—typically covering tens of meters or less—microring resonant modulators (MRM) are emerging as an ideal solution.展开更多
Gastric neuroendocrine tumors (GNETs) are rare lesions characterized by hypergastrinemia that arise from enterochromaffin-like cells of the stomach. GNETs consist of a heterogeneous group of neoplasms comprising tumor...Gastric neuroendocrine tumors (GNETs) are rare lesions characterized by hypergastrinemia that arise from enterochromaffin-like cells of the stomach. GNETs consist of a heterogeneous group of neoplasms comprising tumor types of varying pathogenesis, histomorphologic characteristics, and biological behavior. A classification system has been proposed that distinguishes four types of GNETs; the clinicopathological features of the tumor, its prognosis, and the patient’s survival strictly depend on this classification. Thus, correct management of patients with GNETs can only be proposed when the tumor has been classified by an accurate pathological and clinical evaluation of the patient. Recently developed cancer therapies such as inhibition of angiogenesis or molecular targeting of growth factor receptors have been used to treat GNETs, but the only definitive therapy is the complete resection of the tumor. Here we review the literature on GNETs, and summarize the classification, clinicopathological features (especially prognosis), clinical presentations and current practice of management of GNETs. We also present the latest findings on new gene markers for GNETs, and discuss the effective drugs developed for the diagnosis, prognosis and treatment of GNETs.展开更多
Thermal fatigue behaviors of two forged hot-work die steels subjected to cyclic heating （650 ℃）-water quenching were investigated. A martensitic hot-work die steel containing 10% Cr （HHD）, showing superior oxidat...Thermal fatigue behaviors of two forged hot-work die steels subjected to cyclic heating （650 ℃）-water quenching were investigated. A martensitic hot-work die steel containing 10% Cr （HHD）, showing superior oxidation resistance and thermal fatigue resistance to the commercial martensitic hot-work die steel （Uddeholm DIEVAR ）, was developed. The maximal crack length in HHD was 35% shorter than that in DIEVAR after 2000 thermal cycles, and the hot yield strength at 650℃ of HHD was 14% lower than that of DIEVAR prior to thermal fatigue testing, which is 30% higher after 1500 cycles. It is found that cracks initiated and propagated along the oxide layers in the grain boundaries, suggesting that the oxidation-induced thermal fatigue cracks can significantly reduce the mechanical performance and service life for the hot- work die steel. High-temperature oxidation behavior is crucial for thermal fatigue crack formation, while high-temperature yield strength and ductility play a less important role.展开更多
Lightweight aluminum(Al)alloys have been widely used in frontier fields like aerospace and automotive industries,which attracts great interest in additive manufacturing(AM)to process high-value Al parts.As a mainstrea...Lightweight aluminum(Al)alloys have been widely used in frontier fields like aerospace and automotive industries,which attracts great interest in additive manufacturing(AM)to process high-value Al parts.As a mainstream AM technique,laser-directed energy deposition(LDED)shows good scalability to meet the requirements for large-format component manufacturing and repair.However,LDED Al alloys are highly challenging due to their inherent poor printability(e.g.low laser absorption,high oxidation sensitivity and cracking tendency).To further promote the development of LDED high-performance Al alloys,this review offers a deep understanding of the challenges and strategies to improve printability in LDED Al alloys.The porosity,cracking,distortion,inclusions,element evaporation and resultant inferior mechanical properties(worse than laser powder bed fusion)are the key challenges in LDED Al alloys.Processing parameter optimizations,in-situ alloy design,reinforcing particle addition and field assistance are the efficient approaches to improving the printability and performance of LDED Al alloys.The underlying correlations between processes,alloy innovation,characteristic microstructures,and achievable performances in LDED Al alloys are discussed.The benchmark mechanical properties and primary strengthening mechanism of LDED Al alloys are summarized.This review aims to provide a critical and in-depth evaluation of current progress in LDED Al alloys.Future opportunities and perspectives in LDED high-performance Al alloys are also outlined.展开更多
BACKGROUND Type 1 diabetes is one of the most common chronic diseases in childhood.The number of type 1 diabetes patients in China still ranks fourth in the world.Therefore,children with type 1 diabetes in China are a...BACKGROUND Type 1 diabetes is one of the most common chronic diseases in childhood.The number of type 1 diabetes patients in China still ranks fourth in the world.Therefore,children with type 1 diabetes in China are a group that needs attention.The management of type 1 diabetes mellitus(T1DM)involves many aspects of daily life.It is extremely challenging for children and their families.T1DM children have complex medical care needs.Despite the continuous development of therapeutic medicine and treatment technologies,blood glucose control in children with T1DM is still not ideal.They and their parents need to acquire more knowledge and skills before being discharged.AIM To explore the influence of hospital discharge plan based on parental care needs of children with T1DM on discharge readiness,quality of discharge education and blood glucose control level.METHODS In total,102 parents of children with type 1 diabetes were divided into control group and intervention group according to admission time.Fifty cases from February to June 2019 were selected as the control group,and 52 cases from July to October 2019 were selected as the intervention group to implement the discharge plan.The Readiness for Hospital Discharge Scale,Hospital Discharged Education Quality Scale and children's blood glucose metabolism indicators were used to compare the differences in discharge preparation,discharge education quality and blood glucose control between the two groups of children and their parents.RESULTS On the day of discharge,the two groups of children had the following scores of readiness for discharge:The intervention group score was 225.34±32.47,and the control group score was 208.68±29.31.The P value was 0.007,and the difference was statistically significant.The discharge education quality scores were as follows:The intervention group score was 135.11±19.86,the control group score was 124.13±15.56,the P value was 0.002 and the difference was statistically significant.Three months after discharge,the blood glucose metabolism indicator showed that the glycosylated hemoglobin value of the two groups was(7.45%±1.04%),and that of the control group was(8.04%±1.27%),P=0.012.Therefore,the improvement of parents'readiness for discharge,quality of discharge education and blood glucose metabolism indicators(glycosylated hemoglobin,fasting blood glucose and postprandial blood glucose)in the intervention group were better than those in the control group(P<0.05),and the difference was statistically significant.CONCLUSION The discharge plan for children with T1DM can help the children and their families realize the transition from hospital care to home self-management and improve the parents'readiness for discharge,thereby improving children’s blood glucose control levels.展开更多
Copper matrix composites doped with ceramic particles are known to effectively enhance the mechanical properties,thermal expansion behavior and high-temperature stability of copper while maintaining high thermal and e...Copper matrix composites doped with ceramic particles are known to effectively enhance the mechanical properties,thermal expansion behavior and high-temperature stability of copper while maintaining high thermal and electrical conductivity.This greatly expands the applications of copper as a functional material in thermal and conductive components,including electronic packaging materials and heat sinks,brushes,integrated circuit lead frames.So far,endeavors have been focusing on how to choose suitable ceramic components and fully exert strengthening effect of ceramic particles in the copper matrix.This article reviews and analyzes the effects of preparation techniques and the characteristics of ceramic particles,including ceramic particle content,size,morphology and interfacial bonding,on the diathermancy,electrical conductivity and mechanical behavior of copper matrix composites.The corresponding models and influencing mechanisms are also elaborated in depth.This review contributes to a deep understanding of the strengthening mechanisms and microstructural regulation of ceramic particle reinforced copper matrix composites.By more precise design and manipulation of composite microstructure,the comprehensive properties could be further improved to meet the growing demands of copper matrix composites in a wide range of application fields.展开更多
The innovative and environmentally friendly methodologies for comprehensively enhancing the performances of high-strength steels without damage to plasticity,toughness and heat/corrosion/fatigue resistance are being d...The innovative and environmentally friendly methodologies for comprehensively enhancing the performances of high-strength steels without damage to plasticity,toughness and heat/corrosion/fatigue resistance are being developed.In recent years,nanoparticles elevate the field of high-strength steel.It is proposed that nanoparticles have the potential to replace conventional semi-coherent intermetallic compounds,carbides and alloying to optimize the steel.The fabrication process is simplified and the cost is lower compared with the traditional methods.Considerable research effort has been directed towards high-performance cast steels reinforced with nanoparticles due to potential application in major engineering.Nanoparticles are found to be capable of notably optimizing the nucleation behavior and precipitate process.The prominently optimized microstructure configuration and performances of cast steel can be acquired synchronously.In this review,the lattice matching and valence electron criterion between diverse nanoparticles and steel are summarized,and the existing various preparation methods are compared and analyzed.At present,there are four main methods to introduce nanoparticles into steel:external nanoparticle method,internal nanoparticle method,in-situ reaction method,and additive manufacturing method.These four methods have their own advantages and limitations,respectively.In this review,the synthesis,selection principle and strengthening mechanism of nanoparticles in cast steels for the above four methods are discussed in detail.Moreover,the main preparation methods and microstructure manipulation mechanism of the steel reinforced with different nanoparticles have been systematically expatiated.Finally,the development and future potential research directions of the application of nanoparticles in cast steel are prospected.展开更多
基金the financial support from the National Key R&D Program of China(No.2022YFC2904405)the National Natural Science Foundation of China(Nos.22078055,51774079)。
文摘To synergistically recover alumina and alkali from red mud(RM),the structural stability and conversion mechanism of hydroandradite(HA)from hydrogarnet(HG)were investigated via the First-principles,XRF,XRD,PSD and SEM methods,and a novel hydrothermal process based on the conversion principle was finally proposed.The crystal structure simulation shows that the HA with varied silicon saturation coefficients is more stable than HG,and the HA with a high iron substitution coefficient is more difficult to be converted from HG.The(110)plane of Fe_(2)O_(3) is easier to combine with HG to form HA,and the binding energy is 81.93 kJ/mol.The effects of raw material ratio,solution concentration and hydrothermal parameters on the conversion from HG to HA were revealed,and the optimal conditions for the alumina recovery were obtained.The recovery efficiencies of alumina and Na_(2)O from the RM are 63.06%and 97.34%,respectively,and the Na_(2)O content in the treated RM is only 0.13%.
基金supported by the National Natural Science Foundation of China (No.22409038,52473221)Zhejiang Province Postdoctoral Science Foundation (No.ZJ2024021)+2 种基金Hubei Provincial Natural Science Foundation of China (Nos.2024DJC032,2025AFB889)Key Project of Science and Technology Research of Hubei Provincial Department of Education (Nos.D20232701,D20232702)the research grant funded by the Research,Development,and Innovation Authority (RDIA)-Kingdom of Saudi Arabia (No.12615-iu-2023-IU-R-2-1-EI-)。
文摘Hydrogen peroxide(H_(2)O_(2)) has been recognized as a green and nonpolluting multifunctional oxidant with extensive applications in environmental protection,metal etching,textile printing and dyeing,chemical synthesis and food processing.However,over 90 % of industrial H_(2)O_(2) is currently produced through the multi-step anthraquinone oxidation process,which suffers from a process with some drawbacks such as complex,high-energy consumption,and toxic byproducts emissions.Compared to the traditional anthraquinone method,artificial photosynthesis of H_(2)O_(2) using semiconductor photocatalysts has emerged as a sustainable alternative due to its use of water and O_(2) as the clean reactants and sole energy as the driving force.In recent years,metal-free photocatalysts mainly including covalent organic frameworks(COFs),covalent triazine frameworks(CTFs) and carbon nitrile(g-C_(3)N_(4)) have garnered significant interest due to their superior thermal and chemical stability,diverse synthesis methods,tunable functionality,light weight nature and non-toxicity.These materials also exhibit adjustable band structure and unique photoelectric properties.Sustainable efforts have been made to advance metal-free photocatalysts for artificial photosynthesis of H_(2)O_(2),however,a comprehensive summary of current research status on metalfree-based photocatalytic overall H_(2)O_(2) production remain scarce.This review outlines recent process in overall H_(2)O_(2) photosynthesis based on metal-free photocatalysts.First,we introduced the fundamental concepts of photocatalytic overall H_(2)O_(2) production.Then,we analyze representative studies on photocatalytic overall H_(2)O_(2) synthesis using metal-free materials.Finally,we discuss the challenges and future perspectives in this field to guide the design and synthesis of metal-free systems for H_(2)O_(2) generation.
基金supported by the National Natural Science Foundation of China(Nos.52371031 and 52574435)the Science and Technology Development Program of Jilin Province,China(No.20250102103JC)+2 种基金the Science and Technology Development Program of Changchun City,China(No.23JQ03)Changbaishan Laboratory,China(No.CBS2025004-03)the Undergraduate Innovation Fund of Jilin University,China(No.S202410183310).
文摘Introducing Ti_(2)AlC particles into TiAl alloys can effectively improve their strength,but this can also lead to stress concentration at the interface,resulting in the reduction of ductility.Therefore,Mn is adopted to synergistically improve the strength and ductility of the Ti_(2)AlC/TiAl composite through solid solution and interface manipulation.The first-principles calculation shows the Ti-Mn bonds are formed at the Ti_(2)AlC/TiAl interface after Mn doping,characterized primarily by metallic bonds with some covalent bonding.This combination preserves strength while enhancing ductility.Then,Ti_(2)AlC/TiAl-Mn composite is prepared.The Ti_(2)AlC,with an average size of 1.6μm,is uniformly distributed within the TiAl matrix.Mn doping reduces the lamellar colony size and lamellar thickness by 25.1%and 27.4%,respectively.A small quantity of Mn accumulates at the boundaries of the lamellar colonies.The Mn content must be controlled to avoid segregation,which may negatively impact performance.The yield stress,ultimate compressive stress,fracture strain,and product of strength and plasticity of the Ti_(2)AlC/TiAl-Mn composite have been increased by 5.5%,11.5%,10.4%,and 23.0%,respectively,compared to those of the Ti_(2)AlC/TiAl composite.The enhancement in strength is due to the combined effects of grain refinement,solid solution of Mn,and twining strengthening.Grain refinement and twin strengthening also can reduce stress concentration and improve ductility.In addition,at the electronic level,the Ti-Mn bond formed at the interface is contributed to the improvement of ductility.
基金National Natural Science Foundation of China(No.22272149,22062025)Yunnan University’s Research Innovation Fund for Graduate Students(No.KC-23234085)+1 种基金Workstation of Academician Chen Jing of Yunnan Province(No.202105AF150012)Free Exploration Fund for Academician(No.202405AA350001)。
文摘Electrocatalytic conversion of renewable biomass is emerging as a promising route for sustainable chemical production;hence it urgently calls for developing efficient electrocatalysts with low potentials and high current densities.Herein,a Pr-doped Co(OH)_(2)hexagonal sheet(Pr/Co=1/9,in mole)is synthesized by electrodeposition as highly performant catalyst for 5-hydroxymethylfurfural(HMF)oxidation reaction(HMFOR)to produce 2,5-furandicarboxylic acid(FDCA).This novel and low-cost catalyst possesses a rather low onset potential of 1.05 V(vs.RHE)and requires only 1.10 V(vs.RHE)to reach a current density of 10 mA cm^(-2)for HMFOR,significantly outperforming Co(OH)_(2)benchmark(i.e.,210 mV higher to reach10 m A cm^(-2)).The origin of Pr promotion effect as well as the evolution of CoOOH catalytic sites and HMFOR process has been deeply elucidated by physical characterizations,kinetic experiments,in situ electrochemical techniques,and theoretical calculations.The unique Pr-ameliorated CoOOH active centers enable 100%conversion of HMF,99.6%selectivity of FDCA,and 99.7%Faraday efficiency,with a superior cycling durability toward HMFOR.This can be one of the most outstanding results for Co-based HMFOR catalysts to date in the literature.Thereby this work can help open up new horizons for constructing novel and efficient Co-based electrocatalysts by the utilization of lanthanide elements.
基金supported by the studies of intelligent LLRF control algorithms for superconducting RF cavities(No.E129851YR0)the National Natural Science Foundation of China(No.U22A20261)Applications of Artificial Intelligence in the Stability Study of Superconducting Linear Accelerators(No.E429851YR0)。
文摘Superconducting radio-frequency(SRF)cavities are the core components of SRF linear accelerators,making their stable operation considerably important.However,the operational experience from different accelerator laboratories has revealed that SRF faults are the leading cause of short machine downtime trips.When a cavity fault occurs,system experts analyze the time-series data recorded by low-level RF systems and identify the fault type.However,this requires expertise and intuition,posing a major challenge for control-room operators.Here,we propose an expert feature-based machine learning model for automating SRF cavity fault recognition.The main challenge in converting the"expert reasoning"process for SRF faults into a"model inference"process lies in feature extraction,which is attributed to the associated multidimensional and complex time-series waveforms.Existing autoregression-based feature-extraction methods require the signal to be stable and autocorrelated,resulting in difficulty in capturing the abrupt features that exist in several SRF failure patterns.To address these issues,we introduce expertise into the classification model through reasonable feature engineering.We demonstrate the feasibility of this method using the SRF cavity of the China accelerator facility for superheavy elements(CAFE2).Although specific faults in SRF cavities may vary across different accelerators,similarities exist in the RF signals.Therefore,this study provides valuable guidance for fault analysis of the entire SRF community.
基金supported by the National Natural Science Foundation of China(No.12175283)Youth Innovation Promotion Association of Chinese Academy of Sciences(2020410)Advanced Energy Science and Technology Guangdong Laboratory(HND20TDSPCD,HND22PTDZD).
文摘Growth of high-quality Nb_(3)Sn thin films for superconducting radiofrequency(SRF)applications using the vapor diffusion method requires a uniform distribution of tin nuclei on the niobium(Nb)surface.This study examines the mechanism underlying the observed non-uniform distribution of tin nuclei with tin chloride SnCl_(2).Electron backscatter diffraction(EBSD)analysis was used to examine the correlation between the nucleation behavior and orientation of niobium grains in the substrate.The findings of the density functional theory(DFT)simulation are in good agreement with the experimental results,showing that the non-uniform distribution of tin nuclei is the result of the adsorption energy of SnCl_(2)molecules by varied niobium grain orientations.Further analysis indicated that the surface roughness and grain size of niobium also played significant roles in the nucleation behavior.This study provides valuable insights into enhancing the surface pretreatment of niobium substrates during the growth of Nb_(3)Sn thin films using the vapor diffusion method.
文摘BACKGROUND Pyogenic liver abscess(PLA)is a prevalent liver infection with gradual onset and severe symptoms,including fever,abdominal pain,jaundice,and vomiting.Complications like sepsis or toxic shock can also occur.AIM To investigate the clinical value of early ultrasound-guided percutaneous drainage(PCD)in PLA patients,specifically those with non-liquefied abscesses,and evaluate the feasibility of early intervention.METHODS This retrospective analysis included 143 patients with PLA who were admitted to the Department of General Surgery between January 2018 and March 2023.All patients underwent ultrasound-guided PCD.Based on the liquefaction status of the abscess,patients were divided into two groups:Liquefied group and nonliquefied group.Clinical outcomes,including puncture success rate,puncture duration,length of hospital stay,time to fever resolution,abscess shrinkage rate,and complication rates,were compared between the two groups.RESULTS The puncture success rate for all patients was 99.3%,with a postoperative complication rate of 5.59%,and no intraoperative deaths occurred.Compared to the liquefied group,the non-liquefied group had significantly shorter hospital stays(3.9±1.8 days vs 5.1±2.7 days),faster fever resolution(2.4±1.1 days vs 4.9±2.2 days),and quicker abscess shrinkage(>50%)(4.7±1.5 days vs 8.6±3.3 days)(P<0.05).There were no significant differences in puncture success rates or complication rates between the two groups.CONCLUSION Early ultrasound-guided PCD can be safely and effectively performed in PLA,even when the abscess is not fully liquefied or is non-liquefied,supporting the clinical feasibility of early intervention.
基金supported by the National Natural Science Foundation of China(Nos.82274069,82030116,and 82141212)the Young Scientific and Technological Talents(Level Two)in Tianjin(No.QN20230212)+1 种基金Tianjin Education Commission Research Program Project(No.2024KJ004)the Eaglet Plan Project of Tianjin University of Traditional Chinese Medicine(No.XJS2024101).
文摘In continuation of research aimed at identifying anti-inflammatory agents from natural sesquiterpenoids,an activity-guided fractionation approach utilizing lipopolysaccharide(LPS)-mediated RAW264.7 cells was employed to investigate chemical constituents from Inula Britannica(I.britannica).Seven novel sesquiterpenoid dimers inulabritanoids A−G(1−7)and two novel sesquiterpenoid monomers inulabritanoids H(8)and I(9)were isolated from I.britannica together with eighteen known compounds(10−27).The structural elucidation was accomplished through comprehensive analysis of 1D and 2D nuclear magnetic resonance(NMR),high-resolution mass spectrometry(HR-MS),and electronic circular dichroism(ECD)spectra,complemented by quantum chemical calculations.Compounds 1,2,12,16,19,and 26 demonstrated inhibitory effects on NO production,with IC50 values of 3.65,5.48,3.29,6.91,3.12,and 5.67μmol·L^(−1),respectively.Mechanistic studies revealed that compound 1 inhibited IκB kinaseβ(IKKβ)phosphorylation,thereby blocking nuclear factorκB(NF-κB)nuclear translocation,and activated the kelch-like ECH-associated protein 1(Keap1)/nuclear factor erythroid 2-related factor 2(Nrf2)signal pathway,leading to decreased expression of NADPH oxidase 2(NOX-2),inducible nitric oxide synthase(iNOS),tumor necrosis factorα(TNF-α),interleukin-6(IL-6),monocyte chemotactic protein-1(MCP-1),IL-1β,and IL-1αand increased expression of NAD(P)H:quinone oxidoreductase 1(NQO-1)and heme oxygenase-1(HO-1),thus exhibiting anti-inflammatory effects in vitro.These results indicate that dimeric sesquiterpenoids may serve as promising candidates for anti-inflammatory drug development.
基金the National Natural Science Foundation of China(22209144)the Project of the Natural Science Foundation of Yunnan+4 种基金the Yunnan Revitalization Talent Support Program(202201AU070030 and 202201AT070114)the support from the National Natural Science Foundation of China(22065038)the High-Level Talents Introduction in Yunnan Province(C619300A010)the Fund for Excellent Young Scholars of Yunnan(202001AW070008)financial support from the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)under grant number RS-2024-00444389。
文摘2,2',7,7'-Tetrakis(N,N-di(4-methoxyphenyl)amino)-9,9'-spirobifluorene(Spiro)is an essential hole-transport material used in perovskite solar cells(PSCs).However,the redox reaction of Spiro and its impact at the interface with the metal electrode are not yet fully understood.In this study,we introduced a crystalline additive(CA)to regulate the redox process of Spiro and its interface with an Ag electrode.Our findings indicate that CA functions as a molecular scaffold,improving the crystallinity and stability of radicals in Spiro throughout the entire redox reaction.This enhancement increases the hole mobility of Spiro and strengthens the internal electric field,thereby improving hole extraction and transport efficiency at both interfaces.Moreover,the optimized redox reaction of Spiro reduces energy loss at the Ag electrode,significantly boosting the power conversion efficiency to 25.21%.Furthermore,CA mitigates the aggregation of lithium salt and enhances the stability of the device.Our findings contribute to a deeper understanding of hole-transport mechanisms of Spiro and emphasize the importance of reducing energy loss at the Spiro/Ag electrode interface in PSCs.
基金supported by the National Natural Science Foundation of China (Grant Nos. 61925505 and 62405070)"Pioneer" and "Leading Goose" R&D Program of Zhejiang Province (Grant No. 2024C01112)National Key Research and Development Program of China (Grant No. 2023YFB2807100)。
文摘As the demand for computing power in data centers continues to grow, balancing data transmitting speed and energy efficiency has emerged as a critical challenge. Highbandwidth, low-power interconnection schemes are increasingly recognized as core requirements for next-generation intelligent computing center designs^([1, 2]). For short-range optical interconnections of intra-chip and inter-chip—typically covering tens of meters or less—microring resonant modulators (MRM) are emerging as an ideal solution.
基金Supported by National Natural Scientific Foundation of China,No.B1070296
文摘Gastric neuroendocrine tumors (GNETs) are rare lesions characterized by hypergastrinemia that arise from enterochromaffin-like cells of the stomach. GNETs consist of a heterogeneous group of neoplasms comprising tumor types of varying pathogenesis, histomorphologic characteristics, and biological behavior. A classification system has been proposed that distinguishes four types of GNETs; the clinicopathological features of the tumor, its prognosis, and the patient’s survival strictly depend on this classification. Thus, correct management of patients with GNETs can only be proposed when the tumor has been classified by an accurate pathological and clinical evaluation of the patient. Recently developed cancer therapies such as inhibition of angiogenesis or molecular targeting of growth factor receptors have been used to treat GNETs, but the only definitive therapy is the complete resection of the tumor. Here we review the literature on GNETs, and summarize the classification, clinicopathological features (especially prognosis), clinical presentations and current practice of management of GNETs. We also present the latest findings on new gene markers for GNETs, and discuss the effective drugs developed for the diagnosis, prognosis and treatment of GNETs.
基金supported by the Project 985-High Properties Materials of Jilin University.
文摘Thermal fatigue behaviors of two forged hot-work die steels subjected to cyclic heating （650 ℃）-water quenching were investigated. A martensitic hot-work die steel containing 10% Cr （HHD）, showing superior oxidation resistance and thermal fatigue resistance to the commercial martensitic hot-work die steel （Uddeholm DIEVAR ）, was developed. The maximal crack length in HHD was 35% shorter than that in DIEVAR after 2000 thermal cycles, and the hot yield strength at 650℃ of HHD was 14% lower than that of DIEVAR prior to thermal fatigue testing, which is 30% higher after 1500 cycles. It is found that cracks initiated and propagated along the oxide layers in the grain boundaries, suggesting that the oxidation-induced thermal fatigue cracks can significantly reduce the mechanical performance and service life for the hot- work die steel. High-temperature oxidation behavior is crucial for thermal fatigue crack formation, while high-temperature yield strength and ductility play a less important role.
基金supported by the 2022 MTC Young Individual Research Grants(Grant No.M22K3c0097)the Singapore Research,Innovation and Enterprise(RIE)2025 PlanSingapore Aerospace Programme Cycle 16(Grant No.M2215a0073)。
文摘Lightweight aluminum(Al)alloys have been widely used in frontier fields like aerospace and automotive industries,which attracts great interest in additive manufacturing(AM)to process high-value Al parts.As a mainstream AM technique,laser-directed energy deposition(LDED)shows good scalability to meet the requirements for large-format component manufacturing and repair.However,LDED Al alloys are highly challenging due to their inherent poor printability(e.g.low laser absorption,high oxidation sensitivity and cracking tendency).To further promote the development of LDED high-performance Al alloys,this review offers a deep understanding of the challenges and strategies to improve printability in LDED Al alloys.The porosity,cracking,distortion,inclusions,element evaporation and resultant inferior mechanical properties(worse than laser powder bed fusion)are the key challenges in LDED Al alloys.Processing parameter optimizations,in-situ alloy design,reinforcing particle addition and field assistance are the efficient approaches to improving the printability and performance of LDED Al alloys.The underlying correlations between processes,alloy innovation,characteristic microstructures,and achievable performances in LDED Al alloys are discussed.The benchmark mechanical properties and primary strengthening mechanism of LDED Al alloys are summarized.This review aims to provide a critical and in-depth evaluation of current progress in LDED Al alloys.Future opportunities and perspectives in LDED high-performance Al alloys are also outlined.
文摘BACKGROUND Type 1 diabetes is one of the most common chronic diseases in childhood.The number of type 1 diabetes patients in China still ranks fourth in the world.Therefore,children with type 1 diabetes in China are a group that needs attention.The management of type 1 diabetes mellitus(T1DM)involves many aspects of daily life.It is extremely challenging for children and their families.T1DM children have complex medical care needs.Despite the continuous development of therapeutic medicine and treatment technologies,blood glucose control in children with T1DM is still not ideal.They and their parents need to acquire more knowledge and skills before being discharged.AIM To explore the influence of hospital discharge plan based on parental care needs of children with T1DM on discharge readiness,quality of discharge education and blood glucose control level.METHODS In total,102 parents of children with type 1 diabetes were divided into control group and intervention group according to admission time.Fifty cases from February to June 2019 were selected as the control group,and 52 cases from July to October 2019 were selected as the intervention group to implement the discharge plan.The Readiness for Hospital Discharge Scale,Hospital Discharged Education Quality Scale and children's blood glucose metabolism indicators were used to compare the differences in discharge preparation,discharge education quality and blood glucose control between the two groups of children and their parents.RESULTS On the day of discharge,the two groups of children had the following scores of readiness for discharge:The intervention group score was 225.34±32.47,and the control group score was 208.68±29.31.The P value was 0.007,and the difference was statistically significant.The discharge education quality scores were as follows:The intervention group score was 135.11±19.86,the control group score was 124.13±15.56,the P value was 0.002 and the difference was statistically significant.Three months after discharge,the blood glucose metabolism indicator showed that the glycosylated hemoglobin value of the two groups was(7.45%±1.04%),and that of the control group was(8.04%±1.27%),P=0.012.Therefore,the improvement of parents'readiness for discharge,quality of discharge education and blood glucose metabolism indicators(glycosylated hemoglobin,fasting blood glucose and postprandial blood glucose)in the intervention group were better than those in the control group(P<0.05),and the difference was statistically significant.CONCLUSION The discharge plan for children with T1DM can help the children and their families realize the transition from hospital care to home self-management and improve the parents'readiness for discharge,thereby improving children’s blood glucose control levels.
基金supported by National Natural Science Foundation of China(No.51971101)Science and Technology Development Program of Jilin Province,China(20230201146G X)Exploration Foundation of State Key Laboratory of Automotive Simulation and Control(asclzytsxm-202015)。
文摘Copper matrix composites doped with ceramic particles are known to effectively enhance the mechanical properties,thermal expansion behavior and high-temperature stability of copper while maintaining high thermal and electrical conductivity.This greatly expands the applications of copper as a functional material in thermal and conductive components,including electronic packaging materials and heat sinks,brushes,integrated circuit lead frames.So far,endeavors have been focusing on how to choose suitable ceramic components and fully exert strengthening effect of ceramic particles in the copper matrix.This article reviews and analyzes the effects of preparation techniques and the characteristics of ceramic particles,including ceramic particle content,size,morphology and interfacial bonding,on the diathermancy,electrical conductivity and mechanical behavior of copper matrix composites.The corresponding models and influencing mechanisms are also elaborated in depth.This review contributes to a deep understanding of the strengthening mechanisms and microstructural regulation of ceramic particle reinforced copper matrix composites.By more precise design and manipulation of composite microstructure,the comprehensive properties could be further improved to meet the growing demands of copper matrix composites in a wide range of application fields.
基金financially supported by the National Natural ScienceFoundation of China(Grant No.51971101 and No.51771081)the Science and Technology Development Program of Jilin Province,China(No.20190302004GX)。
文摘The innovative and environmentally friendly methodologies for comprehensively enhancing the performances of high-strength steels without damage to plasticity,toughness and heat/corrosion/fatigue resistance are being developed.In recent years,nanoparticles elevate the field of high-strength steel.It is proposed that nanoparticles have the potential to replace conventional semi-coherent intermetallic compounds,carbides and alloying to optimize the steel.The fabrication process is simplified and the cost is lower compared with the traditional methods.Considerable research effort has been directed towards high-performance cast steels reinforced with nanoparticles due to potential application in major engineering.Nanoparticles are found to be capable of notably optimizing the nucleation behavior and precipitate process.The prominently optimized microstructure configuration and performances of cast steel can be acquired synchronously.In this review,the lattice matching and valence electron criterion between diverse nanoparticles and steel are summarized,and the existing various preparation methods are compared and analyzed.At present,there are four main methods to introduce nanoparticles into steel:external nanoparticle method,internal nanoparticle method,in-situ reaction method,and additive manufacturing method.These four methods have their own advantages and limitations,respectively.In this review,the synthesis,selection principle and strengthening mechanism of nanoparticles in cast steels for the above four methods are discussed in detail.Moreover,the main preparation methods and microstructure manipulation mechanism of the steel reinforced with different nanoparticles have been systematically expatiated.Finally,the development and future potential research directions of the application of nanoparticles in cast steel are prospected.
