BACKGROUND Endoscopic healing(EH)is a key therapeutic target in Crohn’s disease(CD).Proximal small bowel(SB)lesions in patients with CD are associated with a significant risk of strictures and bowel resection.Assessi...BACKGROUND Endoscopic healing(EH)is a key therapeutic target in Crohn’s disease(CD).Proximal small bowel(SB)lesions in patients with CD are associated with a significant risk of strictures and bowel resection.Assessing SB in patients with CD is necessary because of its significant therapeutic implications.The advent of biologic therapies,including infliximab,ustekinumab,and vedolizumab,has significantly altered CD treatment.However,data on the efficacy of biologics in achieving EH,specifically in the proximal SB of patients with CD,remain limited.AIM To assess the effectiveness of biologics for EH in patients with jejunal and/or proximal ileal CD.METHODS Between 2017 and 2023,we retrospectively included 110 consecutive patients with isolated proximal SB CD,identified through baseline balloon-assisted enteroscopy.These patients completed 1-year of treatment with infliximab,ustekinumab,or vedolizumab,and underwent a second balloon-assisted enteroscopy at 1 year.Complete EH was defined as a modified Simple Endoscopic Score for CD(SES-CD)of<3,while EH of the jejunum and proximal ileum was defined as a segmental modified SES-CD of 0.RESULTS In total,64 patients were treated with infliximab,28 with ustekinumab,and 18 with vedolizumab.The complete EH rate at 1 year was 20.9%(23/110),with 29.6%(19/64)for infliximab,10.7%(3/28)for ustekinumab,and 5.5%(1/18)for vedolizumab.The median modified SES-CD significantly decreased compared to baseline[5(2-8)vs 8(6-9),P<0.001].The jejunal and proximal ileal EH rates at 1 year were 30.8%(12/39)and 15.5%(16/103),respectively.Multiple logistic regression analysis showed that stricturing or penetrating disease[odds ratio(OR)=0.261,95%CI:0.087-0.778,P=0.016],prior exposure to biologics(OR=0.080,95%CI:0.010-0.674,P=0.020),and moderate-tosevere endoscopic disease(OR=0.277,95%CI:0.093-0.829,P=0.022)were associated with a lower likelihood of achieving EH at 1 year.CONCLUSION Only 20.9%of patients with isolated proximal SB CD achieved complete EH after 1 year of biologic therapy.展开更多
The strategy of N-doping in carbon materials could provide additional Li-ion storage sites to improve their electrochemical properties. Heteroatom-containing polymers could serve as good precursors to fabricate doped ...The strategy of N-doping in carbon materials could provide additional Li-ion storage sites to improve their electrochemical properties. Heteroatom-containing polymers could serve as good precursors to fabricate doped carbons due to the capability to in situ dope heteroatoms into the structures, In this work, electrospun heterocyclic polyimide （PI） nanofiber membranes containing biphenyl and pyrimidine rings were carbonized to fabricate freestanding and flexible heteroatoms-containing carbon membranes. When the polymer membranes were subjected to various calcination temperatures （from 550℃ to 950 ℃） and durations （0.5-10 h）, the structural evolutions strongly affect their electrochemical properties as anodes for lithium ion batteries. It demonstrated that the reversible specific capacity of obtained sample treated at 650 ℃ for 3 h could achieve 695 mAh/g at 0.1 A/g and retain 245 mAh/g at 1.5 A/g after 300 cycles. Furthermore, the electrospun membrane maintains a good electrochemical performance at bending state as a flexible electrode.展开更多
Selective hydrogenation of biomass-derived maleic anhydride(MAH)to succinic anhydride(SA)is valuable but remains a challenge due to the complicated reaction network.We here report that single Pt atoms decorated onto t...Selective hydrogenation of biomass-derived maleic anhydride(MAH)to succinic anhydride(SA)is valuable but remains a challenge due to the complicated reaction network.We here report that single Pt atoms decorated onto the edges of two-dimensional(2D)1Tphase MoS_(2)(Pt1/1T-MOS_(2)SAC)as a proof-of-concept catalyst can efficiently convert biomass-derived MAH to SA with 100%conversion and 100%selectivity under mild conditions.The kinetic data and characterization results suggest that the catalytic performance of the edge-anchored Pt1/1T-MoS_(2)SAC originates from the facile H_(2)dissociation induced by the electron-deficient Pt1atoms and the pocket-like configuration of Pt1active site confines the adsorption configuration of MAH by the steric effect.The strategy of fabricating edge-confined catalysts offers a new direction to design novel SACs for biomass-derived transformations.展开更多
[ Objective] A method was developed for the analysis of main metabolites in aromatic rice seeds by gas chromatography-mass spectrometry （GC-MS）. [ Method] The main metabolites in seeds of 9 different aromatic rice v...[ Objective] A method was developed for the analysis of main metabolites in aromatic rice seeds by gas chromatography-mass spectrometry （GC-MS）. [ Method] The main metabolites in seeds of 9 different aromatic rice varieties were compared and analyzed with two methods. Method 1 ： the compound was extracted by the mixture of anhydrous ethanol and methylene chloride （ WV = 1：1 ） at 60 ℃ for 3 h in water bath; the extract was isolated and detected by gas chromatography-mass spectrometry using HP-5 capillary column with scan monitoring mode. Method 2： the main metabolites in aromatic rice seeds were detected using headspaee solid phase micro-extraction and gas chromatography mass spectrometry （GC-MS）. [ Result ] Fifteen types of common metabolites were found in 9 different aromatic rice varieties. Method 1 was more effective than method 2 in detecting the main metabolites in aromatic rice seeds. [ Conclusion] This study provides an important reference for clarifying the metabolic pathway of main metabolites in aromatic rice and lays the foundation for further rice breeding.展开更多
Shipboard radiosonde soundings are important for detecting and quantifying the multiscale variability of atmosphere-ocean interactions associated with mass exchanges.This study evaluated the accuracies of shipboard Gl...Shipboard radiosonde soundings are important for detecting and quantifying the multiscale variability of atmosphere-ocean interactions associated with mass exchanges.This study evaluated the accuracies of shipboard Global Positioning System(GPS)soundings in the eastern tropical Indian Ocean and South China Sea through a simultaneous balloon-borne inter-comparison of different radiosonde types.Our results indicate that the temperature and relative humidity(RH)measurements of GPS-TanKong(GPS-TK)radiosonde(used at most stations before 2012)have larger biases than those of ChangFeng-06-A(CF-06-A)radiosonde(widely used in current observation)when compared to reference data from Vaisala RS92-SGP radiosonde,with a warm bias of 5℃and dry bias of 10%during daytimes,and a cooling bias of-0.8℃and a moist bias of 6%during nighttime.These systematic biases are primarily attributed to the radiation effects and altitude deviation.An empirical correction algorithm was developed to retrieve the atmospheric temperature and RH profiles.The corrected profiles agree well with that of RS92-SGP,except for uncertainties of CF-06-A in the stratosphere.These correction algorithms were applied to the GPS-TK historical sounding records,reducing biases in the corrected temperature and RH profiles when compared to radio occultation data.The correction of GPS-TK historical records illustrated an improvement in capturing the marine atmospheric structure,with more accurate atmospheric boundary layer height,convective available potential energy,and convective inhibition in the tropical ocean.This study contributes significantly to improving the quality of GPS radiosonde soundings and promotes the sharing of observation in the eastern tropical Indian Ocean and South China Sea.展开更多
Dear Editor, Task allocation strategies are important in multi-robot systems and have been intensely investigated by researchers because they are critical in determining the performance of the system. In this letter, ...Dear Editor, Task allocation strategies are important in multi-robot systems and have been intensely investigated by researchers because they are critical in determining the performance of the system. In this letter, a novel competition-based coordination model is proposed to solve the multi-robot task allocation problem and applied to a multi-robot object tracking scenario.展开更多
China’s lakes are plagued by cadmium(Cd)pollution.Dissolved organic matter(DOM)significantly regulates Cd(II)transport properties at the sediment-water interface.Understanding the effects of different DOM components ...China’s lakes are plagued by cadmium(Cd)pollution.Dissolved organic matter(DOM)significantly regulates Cd(II)transport properties at the sediment-water interface.Understanding the effects of different DOM components on the transportation properties of Cd(II)at the sediment-water interface is essential.In this study,typical DOM from different sources was selected to study Cd(II)mobility at the sediment-water interface.Results showed that terrestrial-derived DOM(fulvic acids,FA)and autochthonous-derived DOM(α-amylase,B1)inhibit Cd(II)sequestration by sediments(42.5%and 5.8%,respectively),while anthropogenic-derived DOM(sodium dodecyl benzene sulfonate,SDBS)increased the Cd(II)adsorption capacity by sediments by 2.8%.Fluorescence quenching coupling with parallel factor analysis(EEM-PARAFAC)was used to characterize different DOM components.The results showed that FA contains three kinds of components(C1,C3:protein-like components,C2:humic-like components);SDBS contains two kinds of components(C1,C2:protein-like components);B1 contains three kinds of components(C1,C2:protein-like components,C3:humic-like components).Three complex reaction modelswere used to characterize the ability of Cd(II)complex with DOM,and it was found that the humic-like component could hardly be complex with Cd(II).Accordingly,humic-like components compete for Cd(II)adsorption sites on the sediment surface and inhibit Cd(II)adsorption fromsediments.Fourier transform infrared spectroscopy(FTIR)of the sediment surface before and after Cd(II)addition was analyzed and proved the competitive adsorption theory.This study provides a better understanding of the Cd(II)mobilization behavior at the sediment-water interface and indicates that the input of humic-like DOM will increase the bioavailability of Cd.展开更多
As surgical procedures transition from conventional resection to advanced tissue-regeneration technologies,human disease therapy has witnessed a great leap forward.In particular,three-dimensional(3D)bioprinting stands...As surgical procedures transition from conventional resection to advanced tissue-regeneration technologies,human disease therapy has witnessed a great leap forward.In particular,three-dimensional(3D)bioprinting stands as a landmark in this setting,by promising the precise integration of biomaterials,cells,and bioactive molecules,thus opening up a novel avenue for tissue/organ regeneration.Curated by the editorial board of Bio-Design and Manufacturing,this review brings together a cohort of leading young scientists in China to dissect the core functionalities and evolutionary trajectory of 3D bioprinting,by elucidating the intricate challenges encountered in the manufacturing of transplantable organs.We further delve into the translational pathway from scientific research to clinical application,emphasizing the imperativeness of establishing a regulatory framework and rigorously enforcing quality-control measures.Finally,this review outlines the strategic landscape and innovative achievements of China in this field and provides a comprehensive roadmap for researchers worldwide to propel this field collectively to even greater heights.展开更多
We developed a pulsar search pipeline based on PulsaR Exploration and Search TOolkit(PRESTO).This pipeline simply runs dedispersion,Fast Fourier Transform(FFT)and acceleration search in process-level parallel to short...We developed a pulsar search pipeline based on PulsaR Exploration and Search TOolkit(PRESTO).This pipeline simply runs dedispersion,Fast Fourier Transform(FFT)and acceleration search in process-level parallel to shorten the processing time.With two parallel strategies,the pipeline can highly shorten the processing time in both normal searches and acceleration searches.This pipeline was first tested with Parkes Multibeam Pulsar Survery(PMPS)data and discovered two new faint pulsars.Then,it was successfully applied in processing the Five-hundred-meter Aperture Spherical radio Telescope(FAST)drift scan data with tens of new pulsar discoveries up to now.The pipeline is only CPU-based and can be easily and quickly deployed in computing nodes for testing purposes or data processing.展开更多
<div style="text-align:justify;"> In this study, a two-dimensional model describing thermal stress on a charge-coupled device (CCD) induced by ms laser pulses was examined. Considering the nonlinearity...<div style="text-align:justify;"> In this study, a two-dimensional model describing thermal stress on a charge-coupled device (CCD) induced by ms laser pulses was examined. Considering the nonlinearity of the CCD’s material parameters and the melting phase transition process of aluminum electrode materials was considered by using equivalent specific heat capacity method, the physical process where a laser pulse irradiating a CCD pixel array was simulated using COMSOL Multiphysics software. The temperature field and thermal stress field were calculated and analyzed. In order to clarify the mechanism producing damage on the CCD detector, Raman spectra from silicon were measured with a micro-Raman spectrometer to determine stress change in the CCD chip. The procedure presented herein illustrates a method for evaluating strain in a CCD after laser irradiation. </div>展开更多
On January 7,2025,an Ms6.8 earthquake struck Dingri County,XigazêCity,in the Xizang Autonomous Region.The epicenter,located near the Shenzha-Dingjie fault zone at the boundary between the Qinghai-Xizang Plateau a...On January 7,2025,an Ms6.8 earthquake struck Dingri County,XigazêCity,in the Xizang Autonomous Region.The epicenter,located near the Shenzha-Dingjie fault zone at the boundary between the Qinghai-Xizang Plateau and the Indian Plate,marked the largest earthquake in the region in recent years.The Shenzha-Dingjie fault zone,situated at the boundary between the Qinghai-Xizang Plateau and the Indian Plate,is a key tectonic feature in the India-Eurasia collision process,exhibiting both thrust and strike-slip faulting.This study analyzed the disaster characteristics induced by the earthquake using Differential Synthetic Aperture Radar Interferometry(DIn SAR)to process Sentinel-1 satellite data and derive pre-and post-earthquake surface deformation information.Additionally,high-resolution optical remote sensing data,UAV(unmanned aerial vehicle)imagery,and airborne Li DAR(light detection and ranging)data were employed to analyze the spatial distribution of the surface rupture zone,with field investigations validating the findings.Key results include:(1)Field verification confirmed that potential landslide hazard points identified via optical image interpretation did not exhibit secondary landslide activity;(2)D-In SAR revealed the co-seismic surface deformation pattern,providing detailed deformation information for the Dingri region;(3)Integration of Li DAR and optical imagery further refined and validated surface rupture characteristics identified by optical-In SAR,indicating a predominantly north-south rupture zone.Additionally,surface fracture features extending in a near east-west direction were observed on the southeast side of the epicenter,accompanied by some infrastructure damage;(4)Surface fracture was most severe in high-intensity seismic areas near the epicenter,with the maximum surface displacement approximately 28 km from the epicenter.The earthquake-induced surface deformation zone spanned approximately 6 km by 46 km,with deformation concentrated primarily on the western side of the Dingmucuo Fault,where maximum subsidence of 0.65 m was detected.On the eastern side,uplift was dominant,reaching a maximum of 0.75 m.This earthquake poses significant threats to local communities and infrastructure,underscoring the urgent need for continued monitoring in affected areas.The findings highlight the effectiveness of multi-source data fusion(space-air-ground based observation)in seismic disaster assessment,offering a methodological framework for rapid post-earthquake disaster response.providing a valuable scientific foundation for mitigating secondary disasters in the region.展开更多
Arsenic(As)contamination in paddy soils has posed a prominent threat to rice production in Asia.Recycling of silicon(Si)from Si-rich combusted rice husk(CRH)could serve as a sustainable strategy to mitigate rice As up...Arsenic(As)contamination in paddy soils has posed a prominent threat to rice production in Asia.Recycling of silicon(Si)from Si-rich combusted rice husk(CRH)could serve as a sustainable strategy to mitigate rice As uptake through their shared transport pathway.Root(soil)application of CRH alone,however,was insufficient to decrease inorganic As(iAs)in polished rice below Chinese food standards(0.2 mg kg^(-1)).In this study,an aqueous Si solution derived from CRH was used for synergistic foliar application over the highest Si-demanding stage(reproductive stage)of rice,following root application of Si,to investigate rice As uptake in both pot and field experiments.In the pot experiment,on the basis of root application of CRH,Si supplementation before the reproductive stage of rice led to a 51%decrease in As concentration on root surface along with a prominent reduction of Fe plaque due to enhanced root suberization,relative to single root application of CRH treatment.In parallel,the expression of OsLis6 gene in the root was downregulated by 91%than that with only root application of CRH.These changes decreased As influx into root by 56%and led correspondingly to 41%lower As transfer to the straw,as compared with root application of CRH treatment.In node I,the expression of OsLis6 decreased concurrently by 71%,leading ultimately to 28%lower iAs accumulation in grains than that with root application of CRH alone.In the field experiment,with single foliar Si,the mitigation of grain iAs occurred only at lower soil As level of 40 mg kg^(-1),while promoted iAs unloading into grains was determined under higher soil As level(80 mg kg^(-1))relative to the control without Si application.It was,therefore,concluded that the mitigation of grain iAs accumulation with soil application of CRH can be strengthened critically by synergistic supply of foliar Si,serving as a more reliable pathway to secure rice production in As-contaminated paddy fields.展开更多
BACKGROUND Liver transplantation(LT)is recognized as an effective approach that offers survival benefits for patients with acute-on-chronic liver failure(ACLF).However,controversies remain regarding the LT selection c...BACKGROUND Liver transplantation(LT)is recognized as an effective approach that offers survival benefits for patients with acute-on-chronic liver failure(ACLF).However,controversies remain regarding the LT selection criteria,and meta-analyses reporting overall survival outcomes across different ACLF severity grades are lacking.AIM To depict a comprehensive postoperative picture of patients with ACLF of varying severity and contribute to updating LT selection.METHODS Systematic searches in Web of Science,EMBASE,PubMed,and Cochrane databases were performed,from inception to December 26,2023,for studies exploring post-transplant outcomes among ACLF patients,stratified by severity grades as identified by the European Association for the Study of the Liver-Chronic Liver Failure criteria.The primary outcome of interest was the survival rate within one year,with post-transplant complications as secondary outcomes.Additionally,the subgroup analysis examined region-specific one-year survival rates.RESULTS A total of 17 studies involving 28025 participants were included.Patients with ACLF-1 and ACLF-2 have favorable survival within one year,with survival rates reaching 87%[95%confidence interval(CI):84%-91%]and 86%(95%CI:81%-91%),respectively.Despite the relatively lower survival(73%,95%CI:66%-80%)and higher incidence of infection(48%,95%CI:29%-67%)observed in ACLF-3 patients,their survival exceeds that of those who do not undergo LT.Moreover,post-transplant survival was highest in North America across all ACLF grades.CONCLUSION LT can provide survival advantages for ACLF patients.To optimize the utilization of scarce donor organs and improve prognosis,comprehensive preoperative health evaluations are essential,especially for ACLF-3 patients.展开更多
BACKGROUND Patients with acute-on-chronic liver failure(ACLF)experience severe immune dysfunction.Liver transplantation(LT)significantly improves survival outcomes.However,the characteristics of peripheral blood lymph...BACKGROUND Patients with acute-on-chronic liver failure(ACLF)experience severe immune dysfunction.Liver transplantation(LT)significantly improves survival outcomes.However,the characteristics of peripheral blood lymphocyte subsets(PBLSs)in this patient population are not well defined,and the dynamics of immune reconstitution post-LT are insufficiently understood.AIM To characterize PBLSs in patients with ACLF prior to LT and to evaluate PBLS reconstitution after LT.METHODS Clinical data from patients undergoing LT in the Transplantation Center,The Third Xiangya Hospital from January 2022 to December 2023 were analyzed retrospectively.Our cohort comprised 44 patients with ACLF,16 patients with acute decompensation of cirrhosis,and 23 patients with compensated cirrhosis.Twenty healthy volunteers were included as controls.PBLSs were evaluated across all groups.The relationship between PBLSs and post-LT prognosis was assessed,and dynamic changes in PBLSs among patients with ACLF were analyzed at different time points.RESULTS Patients with ACLF exhibited a marked reduction in PBLSs compared with healthy volunteers.Natural killer(NK)cell counts were further reduced in patients with ACLF when compared with patients with compensated cirrhosis.PBLSs did not correlate with the etiology or severity of ACLF or with established liver failure scores.Following LT,a rapid restoration of NK cells and B cells was observed in patients with ACLF.However,the cluster of differentiation(CD)3+T cell and CD4+T cell counts decreased 14 days post-LT and subsequently returned to preoperative levels by day 21.CONCLUSION Patients with ACLF exhibited markedly reduced PBLSs,with decreased NK cells potentially linked to progression from compensated cirrhosis to liver failure.NK and B cell were rapidly restored after LT.展开更多
Sodium-ion batteries are the prominent device for stationary energy storage system and low-speed electric vehicles.However,the practical application is still limited by the unsatisfied performance and high cost of the...Sodium-ion batteries are the prominent device for stationary energy storage system and low-speed electric vehicles.However,the practical application is still limited by the unsatisfied performance and high cost of the cathode side,which strictly requires the development of high voltage,high capacity,and earth-abundant cathode material.Ni-Fe-Mn ternary layered oxide has been recognized as one of the most promising standard type of cathodes.However,the composition and phase structure on high-voltage characteristics have not been well investigated.Herein,selecting the typically high-voltage cathode of P2-Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2)as a parent material,we fabricate ten Ni-Fe-Mn ternary layered oxides through replacing the Ni,Mn,or both Ni and Mn by Fe.The thermodynamically stable phase diagram for those materials is presented.The electrochemical properties for all the samples are investigated in detail.Three potential Ni-Fe-Mn ternary layered oxides are picked up considering the energy density,cycle stability,kinetics,cost price,and working voltage,which demonstrate great potential for surpassing the performance of lithium iron phosphate.The related electrochemical reaction and fading mechanism are well revealed.This work provides some new foundational Ni-Fe-Mn ternary layered materials for high-voltage sodium-ion batteries.展开更多
The effects of rejuvenation heat treatment(RHT)on the serrated flow behavior and fracture mode of nickel-based superalloys(R26)were investigated by tensile tests and microstructural characterization.The serrated flow ...The effects of rejuvenation heat treatment(RHT)on the serrated flow behavior and fracture mode of nickel-based superalloys(R26)were investigated by tensile tests and microstructural characterization.The serrated flow activation energies were determined to be 41−72 and 64−81 kJ/mol before and after RHT,respectively.Dynamic strain aging in the alloy is caused by the diffusion of carbon atoms into dislocation channels in the nickel matrix.Before RHT,carbides are concentrated at the grain boundaries.Cracks initiate from these carbides and propagate along the grain boundaries.RHT dissolves carbides at grain boundaries,transferring crack initiation to the precipitated phase group in the grains.RHT increases carbon atom concentration in the nickel matrix,enhancing dynamic strain aging and serrated flow behavior.展开更多
The Cu/1010 steel bimetal laminated composites(BLCs)were rolled to different thicknesses to investigate the effect of rolling direction and reduction on the microstructure evolution and mechanical properties.The diffe...The Cu/1010 steel bimetal laminated composites(BLCs)were rolled to different thicknesses to investigate the effect of rolling direction and reduction on the microstructure evolution and mechanical properties.The difference of mechanical properties between the Cu and 1010 steel causes different thickness reductions,percentage spread,and cladding ratios.The formation of strong texture induces larger strength of the rolled samples,and as the volume fraction of 1010 steel is larger in Route-A,its strength is consistently greater than that in Route-B.The obstruction of interface to crystal and dislocation slip results in the formation of interface distortion,inducing dislocation density gradient when the rolling reduction is low in Route-A.The slip planes of the Cu and 1010 steel are more prone to suffer the normal strain,while the shear strain of other crystal planes is obviously larger than the normal strain under rolling load near the interface.展开更多
In our current study,the impact of pre-creep treatment at 300℃ and 560 MPa for 1000 h on the subsequent creep behavior and properties at an elevated temperature of 400℃ have been examined.The characterization of the...In our current study,the impact of pre-creep treatment at 300℃ and 560 MPa for 1000 h on the subsequent creep behavior and properties at an elevated temperature of 400℃ have been examined.The characterization of the resulting creep deformation structure,including twins and dislocation morphology,was conducted using scanning electron microscopy(SEM),electron backscatter diffraction(EBSD),and transmission electron microscopy(TEM).Additionally,we have focused on the fine crystallization behavior of theαphase during creep,as well as the study and discussion of the<α>dislocations and pyramidal<c+α>dislocations.Our findings indicate that the creep life at 400℃and 560 MPa is significantly lower,by an order of magnitude,compared to samples without pre-creep treatment.During the pre-creep process at 300℃,<α>dislocations were found to be active.Furthermore,the creep temperature was observed to reduce the critical resolved shear stress(CRSS)of pyramidal<c+α>dislocations,leading to increased dislocation activity at 400℃compared to 300℃.However,a substantial number of<α>dislocations activated during the pre-creep process were unable to accommodate the subsequent heating process,resulting in extensive intergranular fractures.Simultaneously,during the creep process,theαphase underwent marginal fine grain formation in the form of continuous dynamic recrystallization(CDRX),with its internal fine grain promoted by pyramidal<c+α>dislocations assisting<α>dislocation to form dislocation locks.These findings offer valuable insights into potential deformation mechanisms and failure causes of PM-HIP Ti-6Al-4 V alloy when subjected to elevated temperatures during creep.展开更多
The Zoige Plateau,situated on the eastern edge of the Qinghai-Tibet Plateau,exhibits complex groundwater dynamics influenced by alpine hydrological processes and climatic variability.This study investigates the spatio...The Zoige Plateau,situated on the eastern edge of the Qinghai-Tibet Plateau,exhibits complex groundwater dynamics influenced by alpine hydrological processes and climatic variability.This study investigates the spatiotemporal evolution of groundwater in the Zoige alpine basin from 2002 to 2024 using an integrated approach that combines in-situ monitoring,GRACE satellite observations,and GLDAS model outputs.Using the Innovative Trend Analysis(ITA)method alongside conventional statistical techniques,we identified both seasonal fluctuations and long-term depletion trends.Groundwater levels exhibited clear wet–dry season contrasts and a cumulative decline of up to 2.3 m in grassland flatlands,corresponding to a long-term depletion rate of 0.4 cm/a as indicated by GRACE-derived groundwater storage.The most significant declines occurred in grassland zones,driven by wetland degradation and elevated evapotranspiration,while mountain regions showed slower losses(~0.1 cm/a)primarily supported by sustained snowmelt recharge.Through the integration of multi-source datasets,this study highlights the spatial heterogeneity and key drivers of groundwater variation,providing a robust framework for sustainable groundwater management under climatic and anthropogenic pressures in alpine wetland systems.展开更多
基金Supported by the Program of Guangdong Provincial Clinical Research Center for Digestive Diseases,No.2020B1111170004.
文摘BACKGROUND Endoscopic healing(EH)is a key therapeutic target in Crohn’s disease(CD).Proximal small bowel(SB)lesions in patients with CD are associated with a significant risk of strictures and bowel resection.Assessing SB in patients with CD is necessary because of its significant therapeutic implications.The advent of biologic therapies,including infliximab,ustekinumab,and vedolizumab,has significantly altered CD treatment.However,data on the efficacy of biologics in achieving EH,specifically in the proximal SB of patients with CD,remain limited.AIM To assess the effectiveness of biologics for EH in patients with jejunal and/or proximal ileal CD.METHODS Between 2017 and 2023,we retrospectively included 110 consecutive patients with isolated proximal SB CD,identified through baseline balloon-assisted enteroscopy.These patients completed 1-year of treatment with infliximab,ustekinumab,or vedolizumab,and underwent a second balloon-assisted enteroscopy at 1 year.Complete EH was defined as a modified Simple Endoscopic Score for CD(SES-CD)of<3,while EH of the jejunum and proximal ileum was defined as a segmental modified SES-CD of 0.RESULTS In total,64 patients were treated with infliximab,28 with ustekinumab,and 18 with vedolizumab.The complete EH rate at 1 year was 20.9%(23/110),with 29.6%(19/64)for infliximab,10.7%(3/28)for ustekinumab,and 5.5%(1/18)for vedolizumab.The median modified SES-CD significantly decreased compared to baseline[5(2-8)vs 8(6-9),P<0.001].The jejunal and proximal ileal EH rates at 1 year were 30.8%(12/39)and 15.5%(16/103),respectively.Multiple logistic regression analysis showed that stricturing or penetrating disease[odds ratio(OR)=0.261,95%CI:0.087-0.778,P=0.016],prior exposure to biologics(OR=0.080,95%CI:0.010-0.674,P=0.020),and moderate-tosevere endoscopic disease(OR=0.277,95%CI:0.093-0.829,P=0.022)were associated with a lower likelihood of achieving EH at 1 year.CONCLUSION Only 20.9%of patients with isolated proximal SB CD achieved complete EH after 1 year of biologic therapy.
基金financially supported by the DHU Distinguished Young Professor Programthe National Natural Science Foundation of China (No. 51403036)
文摘The strategy of N-doping in carbon materials could provide additional Li-ion storage sites to improve their electrochemical properties. Heteroatom-containing polymers could serve as good precursors to fabricate doped carbons due to the capability to in situ dope heteroatoms into the structures, In this work, electrospun heterocyclic polyimide （PI） nanofiber membranes containing biphenyl and pyrimidine rings were carbonized to fabricate freestanding and flexible heteroatoms-containing carbon membranes. When the polymer membranes were subjected to various calcination temperatures （from 550℃ to 950 ℃） and durations （0.5-10 h）, the structural evolutions strongly affect their electrochemical properties as anodes for lithium ion batteries. It demonstrated that the reversible specific capacity of obtained sample treated at 650 ℃ for 3 h could achieve 695 mAh/g at 0.1 A/g and retain 245 mAh/g at 1.5 A/g after 300 cycles. Furthermore, the electrospun membrane maintains a good electrochemical performance at bending state as a flexible electrode.
基金financially supported by the National Natural Science Foundation of China(Nos.21908079,21872145 and U21A20326)Jiangsu Specially-Appointed Professor Fund(No.1046010241211400)+4 种基金Natural Science Foundation of Jiangsu Province(Nos.BK20211239,BK20221541 and BK20201345)the State Key Laboratory of Fine ChemicalsDalian University of Technology(No.KF2005)Dalian Institute of Chemical Physics(No.DICP 1201943)the Central Laboratory,School of Chemical and Material Engineering,Jiangnan University。
文摘Selective hydrogenation of biomass-derived maleic anhydride(MAH)to succinic anhydride(SA)is valuable but remains a challenge due to the complicated reaction network.We here report that single Pt atoms decorated onto the edges of two-dimensional(2D)1Tphase MoS_(2)(Pt1/1T-MOS_(2)SAC)as a proof-of-concept catalyst can efficiently convert biomass-derived MAH to SA with 100%conversion and 100%selectivity under mild conditions.The kinetic data and characterization results suggest that the catalytic performance of the edge-anchored Pt1/1T-MoS_(2)SAC originates from the facile H_(2)dissociation induced by the electron-deficient Pt1atoms and the pocket-like configuration of Pt1active site confines the adsorption configuration of MAH by the steric effect.The strategy of fabricating edge-confined catalysts offers a new direction to design novel SACs for biomass-derived transformations.
基金Supported by National Natural Science Foundation of China(U1604110,31600992,U1404319,31270727)Key Science and Technology Program of Henan Province(152102110100,152102110036)+6 种基金Major Project of Science and Technology of Henan Province(121100110200)Project of Scientific and Technological Innovation Team for Colleges and Universities in Henan Province(14IRTSTHN012)Students Innovation and Training Program of Institution of Higher Learning in Henan Province(201710477018Y)Key Research Projects of Henan Higher Education Institutions(15A180059,16B180006)Students Innovation and Training Program of XYNU(201710477032)Nanhu Scholars Program for Young Scholars of XYNY(2016054)Open Project of the Institute for Conservation and Utilization of Agro-bioresources in Dabie Mountains
文摘[ Objective] A method was developed for the analysis of main metabolites in aromatic rice seeds by gas chromatography-mass spectrometry （GC-MS）. [ Method] The main metabolites in seeds of 9 different aromatic rice varieties were compared and analyzed with two methods. Method 1 ： the compound was extracted by the mixture of anhydrous ethanol and methylene chloride （ WV = 1：1 ） at 60 ℃ for 3 h in water bath; the extract was isolated and detected by gas chromatography-mass spectrometry using HP-5 capillary column with scan monitoring mode. Method 2： the main metabolites in aromatic rice seeds were detected using headspaee solid phase micro-extraction and gas chromatography mass spectrometry （GC-MS）. [ Result ] Fifteen types of common metabolites were found in 9 different aromatic rice varieties. Method 1 was more effective than method 2 in detecting the main metabolites in aromatic rice seeds. [ Conclusion] This study provides an important reference for clarifying the metabolic pathway of main metabolites in aromatic rice and lays the foundation for further rice breeding.
基金The Second Tibetan Plateau Scientific Expedition and Research Program under contract No.2019QZKK0102-02the National Natural Science Foundation of China under contract Nos 42230402,92158204,42176026,42076201,41049903,41149908,41249906,41249907,and 41249910+2 种基金the Guangdong Basic and Applied Basic Research Foundation under contract No.2022A1515240069the Marine Economic Development Special Program of Guangdong Province(Six Major Marine Industries):Research and Demonstration of Critical Technologies for Comprehensive Prevention and Control of Natural Disaster in Offshore Wind Farms,China under contract No.29[2023]the Fund of Fujian Provincial Key Laboratory of Marine Physical and Geological Processes under contract No.KLMPG-22-02.
文摘Shipboard radiosonde soundings are important for detecting and quantifying the multiscale variability of atmosphere-ocean interactions associated with mass exchanges.This study evaluated the accuracies of shipboard Global Positioning System(GPS)soundings in the eastern tropical Indian Ocean and South China Sea through a simultaneous balloon-borne inter-comparison of different radiosonde types.Our results indicate that the temperature and relative humidity(RH)measurements of GPS-TanKong(GPS-TK)radiosonde(used at most stations before 2012)have larger biases than those of ChangFeng-06-A(CF-06-A)radiosonde(widely used in current observation)when compared to reference data from Vaisala RS92-SGP radiosonde,with a warm bias of 5℃and dry bias of 10%during daytimes,and a cooling bias of-0.8℃and a moist bias of 6%during nighttime.These systematic biases are primarily attributed to the radiation effects and altitude deviation.An empirical correction algorithm was developed to retrieve the atmospheric temperature and RH profiles.The corrected profiles agree well with that of RS92-SGP,except for uncertainties of CF-06-A in the stratosphere.These correction algorithms were applied to the GPS-TK historical sounding records,reducing biases in the corrected temperature and RH profiles when compared to radio occultation data.The correction of GPS-TK historical records illustrated an improvement in capturing the marine atmospheric structure,with more accurate atmospheric boundary layer height,convective available potential energy,and convective inhibition in the tropical ocean.This study contributes significantly to improving the quality of GPS radiosonde soundings and promotes the sharing of observation in the eastern tropical Indian Ocean and South China Sea.
基金supported by the Key Cooperation Project of Chongqing Municipal Education Commission (HZ2021008, HZ2021017)the Project of “Fertilizer Robot” of Chongqing Committee on Agriculture and Rural Affairs。
文摘Dear Editor, Task allocation strategies are important in multi-robot systems and have been intensely investigated by researchers because they are critical in determining the performance of the system. In this letter, a novel competition-based coordination model is proposed to solve the multi-robot task allocation problem and applied to a multi-robot object tracking scenario.
基金supported by the National Natural Science Foundation of China(Nos.42307524,and 51879103).
文摘China’s lakes are plagued by cadmium(Cd)pollution.Dissolved organic matter(DOM)significantly regulates Cd(II)transport properties at the sediment-water interface.Understanding the effects of different DOM components on the transportation properties of Cd(II)at the sediment-water interface is essential.In this study,typical DOM from different sources was selected to study Cd(II)mobility at the sediment-water interface.Results showed that terrestrial-derived DOM(fulvic acids,FA)and autochthonous-derived DOM(α-amylase,B1)inhibit Cd(II)sequestration by sediments(42.5%and 5.8%,respectively),while anthropogenic-derived DOM(sodium dodecyl benzene sulfonate,SDBS)increased the Cd(II)adsorption capacity by sediments by 2.8%.Fluorescence quenching coupling with parallel factor analysis(EEM-PARAFAC)was used to characterize different DOM components.The results showed that FA contains three kinds of components(C1,C3:protein-like components,C2:humic-like components);SDBS contains two kinds of components(C1,C2:protein-like components);B1 contains three kinds of components(C1,C2:protein-like components,C3:humic-like components).Three complex reaction modelswere used to characterize the ability of Cd(II)complex with DOM,and it was found that the humic-like component could hardly be complex with Cd(II).Accordingly,humic-like components compete for Cd(II)adsorption sites on the sediment surface and inhibit Cd(II)adsorption fromsediments.Fourier transform infrared spectroscopy(FTIR)of the sediment surface before and after Cd(II)addition was analyzed and proved the competitive adsorption theory.This study provides a better understanding of the Cd(II)mobilization behavior at the sediment-water interface and indicates that the input of humic-like DOM will increase the bioavailability of Cd.
基金supported by the National Natural Science Foundation of China(Nos.52325504,52235007,and T2121004).
文摘As surgical procedures transition from conventional resection to advanced tissue-regeneration technologies,human disease therapy has witnessed a great leap forward.In particular,three-dimensional(3D)bioprinting stands as a landmark in this setting,by promising the precise integration of biomaterials,cells,and bioactive molecules,thus opening up a novel avenue for tissue/organ regeneration.Curated by the editorial board of Bio-Design and Manufacturing,this review brings together a cohort of leading young scientists in China to dissect the core functionalities and evolutionary trajectory of 3D bioprinting,by elucidating the intricate challenges encountered in the manufacturing of transplantable organs.We further delve into the translational pathway from scientific research to clinical application,emphasizing the imperativeness of establishing a regulatory framework and rigorously enforcing quality-control measures.Finally,this review outlines the strategic landscape and innovative achievements of China in this field and provides a comprehensive roadmap for researchers worldwide to propel this field collectively to even greater heights.
基金supported by the National Key R&D Program of China(2017YFA0402600)State Key DevelopmentProgram for Basic Research(2015CB857100)+4 种基金National Basic Research Program of China(973 program,No.2015CB857101)National Natural Science Foundation of China(Grant Nos.11703047,11773041,U1631132and U1831131)supported by the CAS“Light of West China”Programby the CAS Key Laboratory of FAST,National Astronomical Observatories,Chinese Academy of Sciencessupported in part by the Youth Innovation Promotion Association of CAS(id.2018075)。
文摘We developed a pulsar search pipeline based on PulsaR Exploration and Search TOolkit(PRESTO).This pipeline simply runs dedispersion,Fast Fourier Transform(FFT)and acceleration search in process-level parallel to shorten the processing time.With two parallel strategies,the pipeline can highly shorten the processing time in both normal searches and acceleration searches.This pipeline was first tested with Parkes Multibeam Pulsar Survery(PMPS)data and discovered two new faint pulsars.Then,it was successfully applied in processing the Five-hundred-meter Aperture Spherical radio Telescope(FAST)drift scan data with tens of new pulsar discoveries up to now.The pipeline is only CPU-based and can be easily and quickly deployed in computing nodes for testing purposes or data processing.
文摘<div style="text-align:justify;"> In this study, a two-dimensional model describing thermal stress on a charge-coupled device (CCD) induced by ms laser pulses was examined. Considering the nonlinearity of the CCD’s material parameters and the melting phase transition process of aluminum electrode materials was considered by using equivalent specific heat capacity method, the physical process where a laser pulse irradiating a CCD pixel array was simulated using COMSOL Multiphysics software. The temperature field and thermal stress field were calculated and analyzed. In order to clarify the mechanism producing damage on the CCD detector, Raman spectra from silicon were measured with a micro-Raman spectrometer to determine stress change in the CCD chip. The procedure presented herein illustrates a method for evaluating strain in a CCD after laser irradiation. </div>
基金supported by the National Natural Science Foundation of China(No.42477170)the Major Project of the National Natural Science Foundation of China(No.42090054)+1 种基金the Research Fund Program of Hubei Key Laboratory of Resources and Eco-Environment Geology(No.HBREGKFJJ-202411)Innovative Group Project of Natural Science Foundation of Hubei Province(No.2024AFA015)。
文摘On January 7,2025,an Ms6.8 earthquake struck Dingri County,XigazêCity,in the Xizang Autonomous Region.The epicenter,located near the Shenzha-Dingjie fault zone at the boundary between the Qinghai-Xizang Plateau and the Indian Plate,marked the largest earthquake in the region in recent years.The Shenzha-Dingjie fault zone,situated at the boundary between the Qinghai-Xizang Plateau and the Indian Plate,is a key tectonic feature in the India-Eurasia collision process,exhibiting both thrust and strike-slip faulting.This study analyzed the disaster characteristics induced by the earthquake using Differential Synthetic Aperture Radar Interferometry(DIn SAR)to process Sentinel-1 satellite data and derive pre-and post-earthquake surface deformation information.Additionally,high-resolution optical remote sensing data,UAV(unmanned aerial vehicle)imagery,and airborne Li DAR(light detection and ranging)data were employed to analyze the spatial distribution of the surface rupture zone,with field investigations validating the findings.Key results include:(1)Field verification confirmed that potential landslide hazard points identified via optical image interpretation did not exhibit secondary landslide activity;(2)D-In SAR revealed the co-seismic surface deformation pattern,providing detailed deformation information for the Dingri region;(3)Integration of Li DAR and optical imagery further refined and validated surface rupture characteristics identified by optical-In SAR,indicating a predominantly north-south rupture zone.Additionally,surface fracture features extending in a near east-west direction were observed on the southeast side of the epicenter,accompanied by some infrastructure damage;(4)Surface fracture was most severe in high-intensity seismic areas near the epicenter,with the maximum surface displacement approximately 28 km from the epicenter.The earthquake-induced surface deformation zone spanned approximately 6 km by 46 km,with deformation concentrated primarily on the western side of the Dingmucuo Fault,where maximum subsidence of 0.65 m was detected.On the eastern side,uplift was dominant,reaching a maximum of 0.75 m.This earthquake poses significant threats to local communities and infrastructure,underscoring the urgent need for continued monitoring in affected areas.The findings highlight the effectiveness of multi-source data fusion(space-air-ground based observation)in seismic disaster assessment,offering a methodological framework for rapid post-earthquake disaster response.providing a valuable scientific foundation for mitigating secondary disasters in the region.
基金supported by the National Natural Science Foundation of China(No.42377024)the Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province,Chinathe Key Project of Developmental Biology and Breeding from Hunan Province of China(No.2022XKQ0207).
文摘Arsenic(As)contamination in paddy soils has posed a prominent threat to rice production in Asia.Recycling of silicon(Si)from Si-rich combusted rice husk(CRH)could serve as a sustainable strategy to mitigate rice As uptake through their shared transport pathway.Root(soil)application of CRH alone,however,was insufficient to decrease inorganic As(iAs)in polished rice below Chinese food standards(0.2 mg kg^(-1)).In this study,an aqueous Si solution derived from CRH was used for synergistic foliar application over the highest Si-demanding stage(reproductive stage)of rice,following root application of Si,to investigate rice As uptake in both pot and field experiments.In the pot experiment,on the basis of root application of CRH,Si supplementation before the reproductive stage of rice led to a 51%decrease in As concentration on root surface along with a prominent reduction of Fe plaque due to enhanced root suberization,relative to single root application of CRH treatment.In parallel,the expression of OsLis6 gene in the root was downregulated by 91%than that with only root application of CRH.These changes decreased As influx into root by 56%and led correspondingly to 41%lower As transfer to the straw,as compared with root application of CRH treatment.In node I,the expression of OsLis6 decreased concurrently by 71%,leading ultimately to 28%lower iAs accumulation in grains than that with root application of CRH alone.In the field experiment,with single foliar Si,the mitigation of grain iAs occurred only at lower soil As level of 40 mg kg^(-1),while promoted iAs unloading into grains was determined under higher soil As level(80 mg kg^(-1))relative to the control without Si application.It was,therefore,concluded that the mitigation of grain iAs accumulation with soil application of CRH can be strengthened critically by synergistic supply of foliar Si,serving as a more reliable pathway to secure rice production in As-contaminated paddy fields.
基金Supported by National Natural Science Foundation of China,No.82300857.
文摘BACKGROUND Liver transplantation(LT)is recognized as an effective approach that offers survival benefits for patients with acute-on-chronic liver failure(ACLF).However,controversies remain regarding the LT selection criteria,and meta-analyses reporting overall survival outcomes across different ACLF severity grades are lacking.AIM To depict a comprehensive postoperative picture of patients with ACLF of varying severity and contribute to updating LT selection.METHODS Systematic searches in Web of Science,EMBASE,PubMed,and Cochrane databases were performed,from inception to December 26,2023,for studies exploring post-transplant outcomes among ACLF patients,stratified by severity grades as identified by the European Association for the Study of the Liver-Chronic Liver Failure criteria.The primary outcome of interest was the survival rate within one year,with post-transplant complications as secondary outcomes.Additionally,the subgroup analysis examined region-specific one-year survival rates.RESULTS A total of 17 studies involving 28025 participants were included.Patients with ACLF-1 and ACLF-2 have favorable survival within one year,with survival rates reaching 87%[95%confidence interval(CI):84%-91%]and 86%(95%CI:81%-91%),respectively.Despite the relatively lower survival(73%,95%CI:66%-80%)and higher incidence of infection(48%,95%CI:29%-67%)observed in ACLF-3 patients,their survival exceeds that of those who do not undergo LT.Moreover,post-transplant survival was highest in North America across all ACLF grades.CONCLUSION LT can provide survival advantages for ACLF patients.To optimize the utilization of scarce donor organs and improve prognosis,comprehensive preoperative health evaluations are essential,especially for ACLF-3 patients.
基金Supported by the National Natural Science Foundation of China,No.82300857.
文摘BACKGROUND Patients with acute-on-chronic liver failure(ACLF)experience severe immune dysfunction.Liver transplantation(LT)significantly improves survival outcomes.However,the characteristics of peripheral blood lymphocyte subsets(PBLSs)in this patient population are not well defined,and the dynamics of immune reconstitution post-LT are insufficiently understood.AIM To characterize PBLSs in patients with ACLF prior to LT and to evaluate PBLS reconstitution after LT.METHODS Clinical data from patients undergoing LT in the Transplantation Center,The Third Xiangya Hospital from January 2022 to December 2023 were analyzed retrospectively.Our cohort comprised 44 patients with ACLF,16 patients with acute decompensation of cirrhosis,and 23 patients with compensated cirrhosis.Twenty healthy volunteers were included as controls.PBLSs were evaluated across all groups.The relationship between PBLSs and post-LT prognosis was assessed,and dynamic changes in PBLSs among patients with ACLF were analyzed at different time points.RESULTS Patients with ACLF exhibited a marked reduction in PBLSs compared with healthy volunteers.Natural killer(NK)cell counts were further reduced in patients with ACLF when compared with patients with compensated cirrhosis.PBLSs did not correlate with the etiology or severity of ACLF or with established liver failure scores.Following LT,a rapid restoration of NK cells and B cells was observed in patients with ACLF.However,the cluster of differentiation(CD)3+T cell and CD4+T cell counts decreased 14 days post-LT and subsequently returned to preoperative levels by day 21.CONCLUSION Patients with ACLF exhibited markedly reduced PBLSs,with decreased NK cells potentially linked to progression from compensated cirrhosis to liver failure.NK and B cell were rapidly restored after LT.
基金financially supported by the National Natural Science Foundation of China(Grant No.52402215)the Anhui Provincial Natural Science Foundation(2408085QB036)+1 种基金the Natural Science Research Project of Anhui Province Education Department(Grant Nos.2022AH050334,2022AH030046,2023AH051119)the Scientific Research Foundation of Anhui University of Technology for Talent Introduction(DT2200001211)。
文摘Sodium-ion batteries are the prominent device for stationary energy storage system and low-speed electric vehicles.However,the practical application is still limited by the unsatisfied performance and high cost of the cathode side,which strictly requires the development of high voltage,high capacity,and earth-abundant cathode material.Ni-Fe-Mn ternary layered oxide has been recognized as one of the most promising standard type of cathodes.However,the composition and phase structure on high-voltage characteristics have not been well investigated.Herein,selecting the typically high-voltage cathode of P2-Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2)as a parent material,we fabricate ten Ni-Fe-Mn ternary layered oxides through replacing the Ni,Mn,or both Ni and Mn by Fe.The thermodynamically stable phase diagram for those materials is presented.The electrochemical properties for all the samples are investigated in detail.Three potential Ni-Fe-Mn ternary layered oxides are picked up considering the energy density,cycle stability,kinetics,cost price,and working voltage,which demonstrate great potential for surpassing the performance of lithium iron phosphate.The related electrochemical reaction and fading mechanism are well revealed.This work provides some new foundational Ni-Fe-Mn ternary layered materials for high-voltage sodium-ion batteries.
基金supported by the National Natural Science Foundation of China(No.52175286)the Tribology Science Fund of State Key Laboratory of Tribology in Advanced Equipment,Tsinghua University,China(No.SKLTKF20B16).
文摘The effects of rejuvenation heat treatment(RHT)on the serrated flow behavior and fracture mode of nickel-based superalloys(R26)were investigated by tensile tests and microstructural characterization.The serrated flow activation energies were determined to be 41−72 and 64−81 kJ/mol before and after RHT,respectively.Dynamic strain aging in the alloy is caused by the diffusion of carbon atoms into dislocation channels in the nickel matrix.Before RHT,carbides are concentrated at the grain boundaries.Cracks initiate from these carbides and propagate along the grain boundaries.RHT dissolves carbides at grain boundaries,transferring crack initiation to the precipitated phase group in the grains.RHT increases carbon atom concentration in the nickel matrix,enhancing dynamic strain aging and serrated flow behavior.
基金the National Key Research and Development Program of China(No.2018YFE0306103)the National Natural Science Foundation of China(No.52071050)+1 种基金the Science and Technology Innovation Project of Ningbo,China(No.2021Z032)the Program of China Scholarships Council(No.202106060148).
文摘The Cu/1010 steel bimetal laminated composites(BLCs)were rolled to different thicknesses to investigate the effect of rolling direction and reduction on the microstructure evolution and mechanical properties.The difference of mechanical properties between the Cu and 1010 steel causes different thickness reductions,percentage spread,and cladding ratios.The formation of strong texture induces larger strength of the rolled samples,and as the volume fraction of 1010 steel is larger in Route-A,its strength is consistently greater than that in Route-B.The obstruction of interface to crystal and dislocation slip results in the formation of interface distortion,inducing dislocation density gradient when the rolling reduction is low in Route-A.The slip planes of the Cu and 1010 steel are more prone to suffer the normal strain,while the shear strain of other crystal planes is obviously larger than the normal strain under rolling load near the interface.
基金supported by the National Key R&D Program of China(No.2023YFB3710700)the National Natural Science Foundation of China(No.52074229)the Major Scientific Research Projects in Panxi Experimental Area,and the Key R&D Plan of Sichuan Province(Nos.SC2022A1C01J and 23ZDZX0031).
文摘In our current study,the impact of pre-creep treatment at 300℃ and 560 MPa for 1000 h on the subsequent creep behavior and properties at an elevated temperature of 400℃ have been examined.The characterization of the resulting creep deformation structure,including twins and dislocation morphology,was conducted using scanning electron microscopy(SEM),electron backscatter diffraction(EBSD),and transmission electron microscopy(TEM).Additionally,we have focused on the fine crystallization behavior of theαphase during creep,as well as the study and discussion of the<α>dislocations and pyramidal<c+α>dislocations.Our findings indicate that the creep life at 400℃and 560 MPa is significantly lower,by an order of magnitude,compared to samples without pre-creep treatment.During the pre-creep process at 300℃,<α>dislocations were found to be active.Furthermore,the creep temperature was observed to reduce the critical resolved shear stress(CRSS)of pyramidal<c+α>dislocations,leading to increased dislocation activity at 400℃compared to 300℃.However,a substantial number of<α>dislocations activated during the pre-creep process were unable to accommodate the subsequent heating process,resulting in extensive intergranular fractures.Simultaneously,during the creep process,theαphase underwent marginal fine grain formation in the form of continuous dynamic recrystallization(CDRX),with its internal fine grain promoted by pyramidal<c+α>dislocations assisting<α>dislocation to form dislocation locks.These findings offer valuable insights into potential deformation mechanisms and failure causes of PM-HIP Ti-6Al-4 V alloy when subjected to elevated temperatures during creep.
基金supported by the projects"Investigation of Groundwater Resources in the Yellow River Basin of Sichuan Province(2023-2025)"(N5100012023000974)"Dynamic Evolution and Driving Mechanisms of Water Resources in the Zoige Wetland Based on Multi-Source Remote Sensing"(KJ-2025-062),funded by the Department of Natural Resources of Sichuan Province.
文摘The Zoige Plateau,situated on the eastern edge of the Qinghai-Tibet Plateau,exhibits complex groundwater dynamics influenced by alpine hydrological processes and climatic variability.This study investigates the spatiotemporal evolution of groundwater in the Zoige alpine basin from 2002 to 2024 using an integrated approach that combines in-situ monitoring,GRACE satellite observations,and GLDAS model outputs.Using the Innovative Trend Analysis(ITA)method alongside conventional statistical techniques,we identified both seasonal fluctuations and long-term depletion trends.Groundwater levels exhibited clear wet–dry season contrasts and a cumulative decline of up to 2.3 m in grassland flatlands,corresponding to a long-term depletion rate of 0.4 cm/a as indicated by GRACE-derived groundwater storage.The most significant declines occurred in grassland zones,driven by wetland degradation and elevated evapotranspiration,while mountain regions showed slower losses(~0.1 cm/a)primarily supported by sustained snowmelt recharge.Through the integration of multi-source datasets,this study highlights the spatial heterogeneity and key drivers of groundwater variation,providing a robust framework for sustainable groundwater management under climatic and anthropogenic pressures in alpine wetland systems.
