In this paper,the gluon distribution is extracted from the KLR-AdS/CFT saturation model and used to investigate net-baryon and net-kaon rapidity distributions in ultrarelativistic heavy-ion collisions.With the same pa...In this paper,the gluon distribution is extracted from the KLR-AdS/CFT saturation model and used to investigate net-baryon and net-kaon rapidity distributions in ultrarelativistic heavy-ion collisions.With the same parameters of the saturation model fitting to HERA data and an χ 2 analysis of the overall constant C,the theoretical results are in good agreement with RHIC data in Au+Au collisions at √ s = 0.2 TeV.Then,we present the predictive results for net-baryon rapidity distributions in central Pb+Pb collisions at LHC energies of √ s = 2.76,3.94,and 5.52 TeV,and give the corresponding values of dN/dy for net-baryon at y = 0.展开更多
Rapidity distributions of both E895 proton data at AGS energies and NA49 net proton data at SPS energies can be described reasonably well with a potential version of the Ur QMD in which mean-field potentials for both ...Rapidity distributions of both E895 proton data at AGS energies and NA49 net proton data at SPS energies can be described reasonably well with a potential version of the Ur QMD in which mean-field potentials for both pre-formed hadrons and confined baryons are considered, with the help of a traditional coalescence afterburner in which one parameter set for both relative distance R_0 and relative momentum P_0,(3.8 fm, 0.3 Ge V/c), is used. Because of the large cancellation between the expansion in R_0 and the shrinkage in P_0 through the Lorentz transformation, the relativistic effect in clusters has little effect on the rapidity distribution of free(net) protons. Using a Woods-Saxon-like function instead of a pure logarithmic function as seen by FOPI collaboration at SIS energies, one can fit well both the data at SIS energies and the Ur QMD calculation results at AGS and SPS energies. Further, it is found that for central Au+Au or Pb+Pb collisions at top SIS, SPS and RHIC energies, the proton fractions in clusters are about33%, 10%, and 0.7%, respectively.展开更多
The features of nuclear stopping power and multi-hadron production systematically are studied by making an analysis of rapidity distributions of pion and proton at AGS, SPS and RHIC in this work. It is found that nucl...The features of nuclear stopping power and multi-hadron production systematically are studied by making an analysis of rapidity distributions of pion and proton at AGS, SPS and RHIC in this work. It is found that nuclear stopping power increases linearly with project rapidity yp at AGS and SPS, but that is not liner at RHIC. It is argued that the average rapidity loss is saturated at central rapidity region at RHIC. For pion distribution, it is found that the phase space of pion distribution distributes uniformly in the longitudinal direction,and a linear relationship of <βγ >L with log s is given at AGS and SPS. Non-uniform flow model may explain the features of the distribution at AGS and SPS, but may not ex- plain those of at RHIC.展开更多
The centrality, azimuthal and rapidity dependence of two-particle transverse-momentum correlations are studied for Au-Au collision at 200 GeV using RQMD （relativistic quantum molecular dynamics） with and without fin...The centrality, azimuthal and rapidity dependence of two-particle transverse-momentum correlations are studied for Au-Au collision at 200 GeV using RQMD （relativistic quantum molecular dynamics） with and without final hadron re-scattering models. The influences of the re-scattering effects on the measured correlations are discussed. The results are compared with those from current heavy ion experiments.展开更多
The centrality and energy dependence of rapidity correlation patterns are studied in Au＋Au collisions by using AMPT with string melting, RQMD and UrQMD models. The behaviors of the shortrange correlation （SRC） and ...The centrality and energy dependence of rapidity correlation patterns are studied in Au＋Au collisions by using AMPT with string melting, RQMD and UrQMD models. The behaviors of the shortrange correlation （SRC） and the long-range correlation （LRC） are presented clearly by two spatial-position dependent correlation patterns. For centrality dependence, UrQMD and RQMD give similar results as those in AMPT, i.e., in most central collisions, the correlation structure is flatter and the correlation range is larger, which indicates a long range rapidity correlation. A long range rapidity correlation showing up in RQMD and UrQMD implies that parton interaction is not the only source of long range rapidity correlations. For energy dependence, AMPT with string melting and RQMD show quite different results. The correlation patterns in RQMD at low collision energies and those in AMPT at high collision energies have similar structures, i.e. a convex curve, while the correlation patterns in RQMD at high collision energies and those in AMPT at low collision energies show flat structures, having no position dependence. Long range rapidity correlation presents itself at high energy and disappears at low energy in RQMD, which also indicates that long range rapidity correlations may come from some trivial effects, rather than the parton interactions.展开更多
The quark combination mechanism of hadron production is applied to nucleus-nucleus collisions at the CERN Super Proton Synchrotron （SPS） and the BNL Alternating Gradient Synchrotron （AGS）.The rapidity spectra of i...The quark combination mechanism of hadron production is applied to nucleus-nucleus collisions at the CERN Super Proton Synchrotron （SPS） and the BNL Alternating Gradient Synchrotron （AGS）.The rapidity spectra of identified hadrons and their spectrum widths are studied.The data of π -,K±,φ,Λ,Λ,Ξ - and Ξ＋ at 80 and 40 A GeV,and in particular at 30 and 20 A GeV where the onset of deconfinement is suggested to happen,are consistently described by the quark combination model.However,at AGS 11.6 A GeV below the onset,the π±,K±and Λ spectra cannot be simultaneously explained,indicating the disappearance of the intrinsic correlation of their production in the constituent quark level.The collision-energy dependence of the rapidity spectrum widths of the constituent quarks,and the strangeness of the hot and dense quark matter produced in heavy ion collisions,are obtained and discussed.展开更多
Based on inspection data,the authors analyze and summarize the main types and distribution characteristics of tunnel structural defects.These defects are classified into three types:surface defects,internal defects,an...Based on inspection data,the authors analyze and summarize the main types and distribution characteristics of tunnel structural defects.These defects are classified into three types:surface defects,internal defects,and defects behind the structure.To address the need for rapid detection of different defect types,the current state of rapid detection technologies and equipment,both domestically and internationally,is systematically reviewed.The research reveals that surface defect detection technologies and equipment have developed rapidly in recent years.Notably,the integration of machine vision and laser scanning technologies have significantly improved detection efficiency and accuracy,achieving crack detection precision of up to 0.1 mm.However,the non-contact rapid detection of internal and behind-the-structure defects remains constrained by hardware limitations,with traditional detection remaining dominant.Nevertheless,phased array radar,ultrasonic,and acoustic vibration detection technologies have become research hotspots in recent years,offering promising directions for detecting these challenging defect types.Additionally,the application of multisensor fusion technology in rapid detection equipment has further enhanced detection capabilities.Devices such as cameras,3D laser scanners,infrared thermal imagers,and radar demonstrate significant advantages in rapid detection.Future research in tunnel inspection should prioritize breakthroughs in rapid detection technologies for internal and behind-the-structure defects.Efforts should also focus on developing multifunctional integrated detection vehicles that can simultaneously inspect both surface and internal structures.Furthermore,progress in fully automated,intelligent systems with precise defect identification and real-time reporting will be essential to significantly improve the efficiency and accuracy of tunnel inspection.展开更多
In general,the rapid growth of α-Fe clusters is a challenge in high Fe-content Fe-based amorphous alloys,negatively affecting their physical properties.Herein,we introduce an efficient and rapid post-treatment techni...In general,the rapid growth of α-Fe clusters is a challenge in high Fe-content Fe-based amorphous alloys,negatively affecting their physical properties.Herein,we introduce an efficient and rapid post-treatment technique known as ultrasonic vibration rapid processing(UVRP),which enables the formation of high-density strong magnetic α-Fe clusters,thereby enhancing the soft magnetic properties of Fe_(78)Si(13)B_(9) amorphous alloy ribbon.展开更多
Rice(Oryza sativa L.)plays a pivotal role in global food security,yet its breeding is constrained by its long generation time and seasonality.To enhance rice breeding efficiency and meet future food demands,we have de...Rice(Oryza sativa L.)plays a pivotal role in global food security,yet its breeding is constrained by its long generation time and seasonality.To enhance rice breeding efficiency and meet future food demands,we have developed a vertical hydroponic breeding system integrated with light-emitting diodes(LEDs)light-ing in a closed plant factory(PF),which significantly accelerates rice growth and generation advance-ment.The results show that indica rice can be harvested as early as after 63 days of cultivation,a 50%reduction compared with field cultivation,enabling the annual harvesting of 5-6 generations within the PF.A hyperspectral imaging(HSI)system and attenuated total reflectance infrared(ATR-IR)spec-troscopy were further employed to characterize the chemical composition of the PF-and field-cultivated rice.Metabolomics analysis with ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)and gas chromatography-mass spectrometry(GC-MS)revealed that,com-pared with the field-cultivated rice,the PF-cultivated rice exhibited an up-regulation of total phenolic acids along with 68 non-volatile and 19 volatile metabolites,such as isovitexin,succinic acid,and methylillicinone F.Overall,this study reveals the unique metabolic profile of PF-cultivated rice and high-lights the potential of PFs to accelerate the breeding of crops such as rice,offering an innovative agricul-tural strategy to support food security in the face of global population growth and climate change.展开更多
Low–angle submarine landslides pose a greater threat to offshore infrastructure compared to those with steep sliding angles.Understanding the preparation and triggering mechanism of these low–angle submarine landsli...Low–angle submarine landslides pose a greater threat to offshore infrastructure compared to those with steep sliding angles.Understanding the preparation and triggering mechanism of these low–angle submarine landslides remains a significant challenge.This study focuses on a deformed low–angle submarine landslide in the shelf–slope break of the Pearl River Mouth Basin,South China Sea,integrating sedimentology,geophysics,and geotechnology to investigate potential failure mechanisms.The architecture and deformation characteristics of the submarine landslide were elucidated by analyzing multibeam and seismic data.Within the context of the regional geological history and tectonic framework,this study focuses on the factors(e.g.,rapid sedimentation,fluid activity,and earthquakes)that potentially contributed to the submarine slope failure.Furthermore,a series of stability evaluations considering the effects of rapid sedimentation and earthquakes was conducted.Our findings indicate that the most probable triggering mechanism involves the combined effects of sedimentation controlled by sea–level fluctuations,high–pressure gas activity,and seismic events.The high–pressure gas,which acts as a long–term preconditioning factor by elevating pore pressures and reducing shear resistance within the sediment,accumulated beneath the upper and middle sections of the low–permeability stratum that was formed during sea–level rise and ultimately evolved into the sliding mass.The overpressure generated by gas accumulation predisposed the submarine slope to instability,and a frequent or moderate earthquake ultimately initiated local failure.This study enhances the mechanistic understanding of low–angle slope failures in the shelf–slope break zone and provides critical insights for assessing marine hazard risks.展开更多
Weathering steel exhibits excellent corrosion resistance and is widely used in bridges,towers,railways,highways,and other engineering projects that are exposed to the atmosphere for long periods of time.However,before...Weathering steel exhibits excellent corrosion resistance and is widely used in bridges,towers,railways,highways,and other engineering projects that are exposed to the atmosphere for long periods of time.However,before the formation of stable rust layers,weathering steel is prone to liquid rust sagging and spattering,leading to environmental pollution and city appearance concerns.These factors limit the application and development of weathering steel.In this study,a rapid and environmentally friendly method was de-veloped by introducing alloying elements,specifically investigating the role of Sn in the rapid stabilization of rust layers in marine atmo-spheric environments.The rust layer formed on weathering low-alloy steel exposed to prolonged outdoor conditions and laboratory im-mersion experiments was explored using electron probe micro-analyzer(EPMA),micro-Raman,X-ray photoelectron spectroscopy(XPS),and electrochemical measurements.Results showed an optimal synergistic effect between Sn and Cr,which facilitated the accelerated densification of the rust layer.This beneficial effect enhanced the capability of the rust layer to resist Cl^(-)erosion and improved the protec-tion performance of the rust layer.展开更多
Rapid screening of inorganic arsenic(iAs)in groundwater used for drinking by hundreds of millions of mostly rural residents worldwide is crucial for health protection.Most commercial field test kits are based on the G...Rapid screening of inorganic arsenic(iAs)in groundwater used for drinking by hundreds of millions of mostly rural residents worldwide is crucial for health protection.Most commercial field test kits are based on the Gutzeit reaction that uses mercury-based reagents for color development,an environmental concern that increasingly limits its utilization.This study further improves the Molybdenum Blue(MB)colorimetric method to allow for faster screening with more stable reagents.More importantly,a portable three-channel colorimeter is developed for screening iAs relative to the WHO drinking water guideline value(10μg/L).Adding the reducing reagents in sequence not only prolongs the storage time to>7 days,but also accelerates the color development time to 6 min in conjunction with lowering the H_(2)SO_(4) concentration in chromogenic reagents.The optimal pH ranges from 1.2 to 1.3 and is achieved by acidifying groundwater to 1%(V/V)HCl.With detection limits of 3.7μg/L for inorganic arsenate(iAs(V))and 3.8μg/L for inorganic arsenite(iAs(Ⅲ)),testing groundwater with-10μg/L of As has a precision<20%.The method works well for a range of phosphate concentrations of 48-950μg/L(0.5-10μmol/L).Concentrations of total_iAs(6-300μg/L),iAs(V)(6-230μg/L)and iAs(Ⅲ)(0-170μg/L)for 14 groundwater samples from Yinchuan Plain,Pearl River Delta,and Jianghan Plain,are in excellent agreements(linear regression slope:0.969-1.029)with the benchmark methods.The improved chemistry here lays the foundation for the MB colorimetric method to become a commercially viable screening tool,with further engineering and design improvement of the colorimeter.展开更多
BACKGROUND Esophageal squamous cell carcinoma is a major histological subtype of esophageal cancer.Many molecular genetic changes are associated with its occurrence.Raman spectroscopy has become a new method for the e...BACKGROUND Esophageal squamous cell carcinoma is a major histological subtype of esophageal cancer.Many molecular genetic changes are associated with its occurrence.Raman spectroscopy has become a new method for the early diagnosis of tumors because it can reflect the structures of substances and their changes at the molecular level.AIM To detect alterations in Raman spectral information across different stages of esophageal neoplasia.METHODS Different grades of esophageal lesions were collected,and a total of 360 groups of Raman spectrum data were collected.A 1D-transformer network model was proposed to handle the task of classifying the spectral data of esophageal squamous cell carcinoma.In addition,a deep learning model was applied to visualize the Raman spectral data and interpret their molecular characteristics.RESULTS A comparison among Raman spectral data with different pathological grades and a visual analysis revealed that the Raman peaks with significant differences were concentrated mainly at 1095 cm^(-1)(DNA,symmetric PO,and stretching vibration),1132 cm^(-1)(cytochrome c),1171 cm^(-1)(acetoacetate),1216 cm^(-1)(amide III),and 1315 cm^(-1)(glycerol).A comparison among the training results of different models revealed that the 1Dtransformer network performed best.A 93.30%accuracy value,a 96.65%specificity value,a 93.30%sensitivity value,and a 93.17%F1 score were achieved.CONCLUSION Raman spectroscopy revealed significantly different waveforms for the different stages of esophageal neoplasia.The combination of Raman spectroscopy and deep learning methods could significantly improve the accuracy of classification.展开更多
The core-surface flow is crucial for understanding the dynamics of the Earth's outer core and geomagnetic secular variations.Conventional core flow models often use a single set of spherical harmonic coefficients ...The core-surface flow is crucial for understanding the dynamics of the Earth's outer core and geomagnetic secular variations.Conventional core flow models often use a single set of spherical harmonic coefficients to represent the flow both inside and outside the tangent cylinder,inherently imposing continuity across the tangent cylinder around the solid inner core.To address this limitation,we present a core-surface flow inversion framework based on physics-informed neural networks.This framework employs distinct neural network representations for the flow inside and outside the tangent cylinder,allowing for discontinuities as the flow crosses the tangent cylinder.Additionally,it incorporates secular acceleration data to constrain the temporal evolution of the core flow.Using this inversion framework,we derive a new core-surface flow model spanning 2001 to 2024 from a geomagnetic model,incorporating the latest magnetic data from Swarm satellites and Macao Science Satellite-1.The recovered model reveals persistent large-scale circulation linked to westward drift,significant temporal variations in the equatorial Pacific,and distinct jet-like structures at the poles.The inversion also reveals a large-scale wave pattern in equatorial azimuthal flow acceleration,corresponding to observed geomagnetic jerks and likely resulting from quasi-geostrophic magneto-Coriolis waves.Additionally,the framework infers small-scale magnetic fields at the core-mantle boundary,highlighting split flux concentrations and localized high-latitude patches.展开更多
Drug-eluting magnesium(Mg)alloy stents have a slower degradation rate and lower restenosis rate compared with uncoated stents,demonstrating good clinical efficacy.However,the release of anti-hyperplasia drugs from coa...Drug-eluting magnesium(Mg)alloy stents have a slower degradation rate and lower restenosis rate compared with uncoated stents,demonstrating good clinical efficacy.However,the release of anti-hyperplasia drugs from coatings delays endothelial tissue repair,thus leading to late stent thrombosis.To address these issues,a dual self-healed coating with various biological properties was fabricated on magnesium fluoride/polydopamine(MgF_(2)/PDA)-treated Mg alloys by spraying-assisted layer-by-layer(LBL)self-assembly of chitosan(CS),gallic acid(GA),and 3-aminobenzeneboronic acid-modified hyaluronic acid(HA-ABBA).The LBL coating,approximately 1.50μm thick,exhibited a uniform morphology with good adhesion strength(~1065 mN).The annual corrosion rate(Pi)of LBL samples was~1400 times slower than that of the Mg substrate,due to the physical barrier function provided by MgF_(2)/PDA layers and the dual self-healed ability of LBL layers.The rapid self-healing ability(with a healing period of~4 h under dynamic/static conditions)resulted from the synergistic interplay between the recombination of diverse chemical bonds within the LBL coating and the coordination of LBL-released GA with Mg2+,as corroborated by computer simulations.Compared with the drug-eluting coatings,the LBL sample demonstrated substantial advantages in anti-oxidation,anti-denaturation of fibrinogen,anti-platelet adhesion,anti-inflammation,anti-hyperplasia,and promoted-endothelialization.These benefits effectively address the limitations associated with drug-eluting coatings.展开更多
Short process forming techniques for brazing and soldering materials can shorten the process,improve product quality,and increase production efficiency,which has received much attention from welding researchers.This r...Short process forming techniques for brazing and soldering materials can shorten the process,improve product quality,and increase production efficiency,which has received much attention from welding researchers.This review mainly summarized the research reports on short process forming techniques for brazing and soldering materials.Firstly,the traditional process and its shortcomings were presented.Secondly,the latest research of short process forming technologies,such as continuous casting technique,atomization powder technique,solder ball forming technique,and rapid solidification technique,was summarized,and the traditional forming performance of several brazing and soldering materials was introduced.Finally,the current restrictions and research trends of short process forming technique for brazing and solder materials were put forward,providing theoretical guidance and reference for related research and technique development in brazing and soldering field.展开更多
BACKGROUND At the end of December 2019,the world faced severe acute respiratory syndrome-coronavirus 2(SARS-CoV-2),which led to the outbreak of coronavirus disease 2019(COVID-19),associated with respiratory issues.Thi...BACKGROUND At the end of December 2019,the world faced severe acute respiratory syndrome-coronavirus 2(SARS-CoV-2),which led to the outbreak of coronavirus disease 2019(COVID-19),associated with respiratory issues.This virus has shown significant challenges,especially for senior citizens,patients with other underlying illnesses,or those with a sedentary lifestyle.Serological tests conducted early on have helped identify how the virus is transmitted and how to curb its spread.The study hypothesis was that the rapid serological test for SARS-CoV-2 antibodies could indicate the immunoreactive profile during the COVID-19 pandemic in a university population.AIM To conduct active surveillance for serological expression of anti-SARS-CoV-2 antibodies in individuals within a university setting during the COVID-19 pandemic.METHODS This sectional study by convenience sampling was conducted in a large university in Niteroi-RJ,Brazil,from March 2021 to July 2021.The study population consisted of students,faculty,and administrative staff employed by the university.A total of 3433 faculty members,60703 students,and 3812 administrative staff were invited to participate.Data were gathered through rapid serological tests to detect immunoglobulin(Ig)M and IgG against SARS-CoV-2.Theχ²or Fisher's exact test was used to conduct statistical analysis.A 0.20 significance level was adopted for variable selection in a multiple logistic regression model to evaluate associations.RESULTS A total of 1648 individuals were enrolled in the study.The proportion of COVID-19 positivity was 164/1648(9.8%).The adjusted logistic model indicate a positive association between the expression of IgM or IgG and age[odds ratio(OR)=1.16,95%CI:1.02-1.31](P<0.0024),individuals who had been in contact with a COVID-19-positive case(OR=3.49,95%CI:2.34-5.37)(P<0.001),those who had received the COVID-19 vaccine(OR=2.33,95%CI:1.61-3.35)(P<0.001)and social isolation(OR=0.59,95%CI:0.41-0.84)(P<0.004).The likelihood of showing a positive result increased by 16%with every ten-year increment.Conversely,adherence to social distancing measures decreased the likelihood by 41%.CONCLUSION These findings evidenced that the population became more exposed to the virus as individuals discontinued social distancing practices,thereby increasing the risk of infection for themselves.展开更多
基金Supported by Natural Science Foundation of Hebei Province under Grant No. A2012210043
文摘In this paper,the gluon distribution is extracted from the KLR-AdS/CFT saturation model and used to investigate net-baryon and net-kaon rapidity distributions in ultrarelativistic heavy-ion collisions.With the same parameters of the saturation model fitting to HERA data and an χ 2 analysis of the overall constant C,the theoretical results are in good agreement with RHIC data in Au+Au collisions at √ s = 0.2 TeV.Then,we present the predictive results for net-baryon rapidity distributions in central Pb+Pb collisions at LHC energies of √ s = 2.76,3.94,and 5.52 TeV,and give the corresponding values of dN/dy for net-baryon at y = 0.
基金the National Natural Science Foundation of China(Grant Nos.1137506211547312 and 11275068)+2 种基金the project sponsored by SRF for ROCSSEMand the Doctoral Scientific Research Foundation(Grant No.11447109)
文摘Rapidity distributions of both E895 proton data at AGS energies and NA49 net proton data at SPS energies can be described reasonably well with a potential version of the Ur QMD in which mean-field potentials for both pre-formed hadrons and confined baryons are considered, with the help of a traditional coalescence afterburner in which one parameter set for both relative distance R_0 and relative momentum P_0,(3.8 fm, 0.3 Ge V/c), is used. Because of the large cancellation between the expansion in R_0 and the shrinkage in P_0 through the Lorentz transformation, the relativistic effect in clusters has little effect on the rapidity distribution of free(net) protons. Using a Woods-Saxon-like function instead of a pure logarithmic function as seen by FOPI collaboration at SIS energies, one can fit well both the data at SIS energies and the Ur QMD calculation results at AGS and SPS energies. Further, it is found that for central Au+Au or Pb+Pb collisions at top SIS, SPS and RHIC energies, the proton fractions in clusters are about33%, 10%, and 0.7%, respectively.
基金Supported by the Excellent Youth Foundation of Hubei Scientific Committee (Grant No. 2006ABB036)the Educational Commission of Hubei Province of China (Grant No. Z20081302)and the Natural Science Foundation of China Three Gorges Uni-versity (Grant No. 2003C02)
文摘The features of nuclear stopping power and multi-hadron production systematically are studied by making an analysis of rapidity distributions of pion and proton at AGS, SPS and RHIC in this work. It is found that nuclear stopping power increases linearly with project rapidity yp at AGS and SPS, but that is not liner at RHIC. It is argued that the average rapidity loss is saturated at central rapidity region at RHIC. For pion distribution, it is found that the phase space of pion distribution distributes uniformly in the longitudinal direction,and a linear relationship of <βγ >L with log s is given at AGS and SPS. Non-uniform flow model may explain the features of the distribution at AGS and SPS, but may not ex- plain those of at RHIC.
基金Supported by National Natural Science Foundation of China (90503001, 10610285, 10775056)
文摘The centrality, azimuthal and rapidity dependence of two-particle transverse-momentum correlations are studied for Au-Au collision at 200 GeV using RQMD （relativistic quantum molecular dynamics） with and without final hadron re-scattering models. The influences of the re-scattering effects on the measured correlations are discussed. The results are compared with those from current heavy ion experiments.
基金Supported by National Natural Science Foundation of China (10775056, 10835005, 11005054)
文摘The centrality and energy dependence of rapidity correlation patterns are studied in Au＋Au collisions by using AMPT with string melting, RQMD and UrQMD models. The behaviors of the shortrange correlation （SRC） and the long-range correlation （LRC） are presented clearly by two spatial-position dependent correlation patterns. For centrality dependence, UrQMD and RQMD give similar results as those in AMPT, i.e., in most central collisions, the correlation structure is flatter and the correlation range is larger, which indicates a long range rapidity correlation. A long range rapidity correlation showing up in RQMD and UrQMD implies that parton interaction is not the only source of long range rapidity correlations. For energy dependence, AMPT with string melting and RQMD show quite different results. The correlation patterns in RQMD at low collision energies and those in AMPT at high collision energies have similar structures, i.e. a convex curve, while the correlation patterns in RQMD at high collision energies and those in AMPT at low collision energies show flat structures, having no position dependence. Long range rapidity correlation presents itself at high energy and disappears at low energy in RQMD, which also indicates that long range rapidity correlations may come from some trivial effects, rather than the parton interactions.
基金Supported by National Natural Science Foundation of China (11175104,10947007,10975092)
文摘The quark combination mechanism of hadron production is applied to nucleus-nucleus collisions at the CERN Super Proton Synchrotron （SPS） and the BNL Alternating Gradient Synchrotron （AGS）.The rapidity spectra of identified hadrons and their spectrum widths are studied.The data of π -,K±,φ,Λ,Λ,Ξ - and Ξ＋ at 80 and 40 A GeV,and in particular at 30 and 20 A GeV where the onset of deconfinement is suggested to happen,are consistently described by the quark combination model.However,at AGS 11.6 A GeV below the onset,the π±,K±and Λ spectra cannot be simultaneously explained,indicating the disappearance of the intrinsic correlation of their production in the constituent quark level.The collision-energy dependence of the rapidity spectrum widths of the constituent quarks,and the strangeness of the hot and dense quark matter produced in heavy ion collisions,are obtained and discussed.
文摘Based on inspection data,the authors analyze and summarize the main types and distribution characteristics of tunnel structural defects.These defects are classified into three types:surface defects,internal defects,and defects behind the structure.To address the need for rapid detection of different defect types,the current state of rapid detection technologies and equipment,both domestically and internationally,is systematically reviewed.The research reveals that surface defect detection technologies and equipment have developed rapidly in recent years.Notably,the integration of machine vision and laser scanning technologies have significantly improved detection efficiency and accuracy,achieving crack detection precision of up to 0.1 mm.However,the non-contact rapid detection of internal and behind-the-structure defects remains constrained by hardware limitations,with traditional detection remaining dominant.Nevertheless,phased array radar,ultrasonic,and acoustic vibration detection technologies have become research hotspots in recent years,offering promising directions for detecting these challenging defect types.Additionally,the application of multisensor fusion technology in rapid detection equipment has further enhanced detection capabilities.Devices such as cameras,3D laser scanners,infrared thermal imagers,and radar demonstrate significant advantages in rapid detection.Future research in tunnel inspection should prioritize breakthroughs in rapid detection technologies for internal and behind-the-structure defects.Efforts should also focus on developing multifunctional integrated detection vehicles that can simultaneously inspect both surface and internal structures.Furthermore,progress in fully automated,intelligent systems with precise defect identification and real-time reporting will be essential to significantly improve the efficiency and accuracy of tunnel inspection.
基金supported by the Major Science and Technology Project of Zhongshan City(No.2022AJ004)the Key Basic and Applied Research Program of Guangdong Province(Nos.2019B030302010 and 2022B1515120082)Guangdong Science and Technology Innovation Project(No.2021TX06C111).
文摘In general,the rapid growth of α-Fe clusters is a challenge in high Fe-content Fe-based amorphous alloys,negatively affecting their physical properties.Herein,we introduce an efficient and rapid post-treatment technique known as ultrasonic vibration rapid processing(UVRP),which enables the formation of high-density strong magnetic α-Fe clusters,thereby enhancing the soft magnetic properties of Fe_(78)Si(13)B_(9) amorphous alloy ribbon.
基金supported by the National Key Research and Development Program(2023YFF1001500)the Local Financial Funds of National Agricultural Science and Technology Center,Chengdu(NASC2022KR02,NASC2023TD08,NASC2021ST08,NASC2021PC04,NASC2022KR07,NASC2022KR06,and NASC2023ST04)+2 种基金the Agricultural Science and Technology Innova-tion Program(ASTIP-34-IUA-01,ASTIP-34-IUA-02,ASTIP-IUA-2023003,and ASTIP2024-34-IUA-09)the Central Public-interest Scientific Institution Basal Research Fund(Y2023YJ07 and SZ202403)the Sichuan Science and Technology Program(2023YFN003,2024NSFC1261,2023YFQ0100,and 2023ZYD0089).
文摘Rice(Oryza sativa L.)plays a pivotal role in global food security,yet its breeding is constrained by its long generation time and seasonality.To enhance rice breeding efficiency and meet future food demands,we have developed a vertical hydroponic breeding system integrated with light-emitting diodes(LEDs)light-ing in a closed plant factory(PF),which significantly accelerates rice growth and generation advance-ment.The results show that indica rice can be harvested as early as after 63 days of cultivation,a 50%reduction compared with field cultivation,enabling the annual harvesting of 5-6 generations within the PF.A hyperspectral imaging(HSI)system and attenuated total reflectance infrared(ATR-IR)spec-troscopy were further employed to characterize the chemical composition of the PF-and field-cultivated rice.Metabolomics analysis with ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)and gas chromatography-mass spectrometry(GC-MS)revealed that,com-pared with the field-cultivated rice,the PF-cultivated rice exhibited an up-regulation of total phenolic acids along with 68 non-volatile and 19 volatile metabolites,such as isovitexin,succinic acid,and methylillicinone F.Overall,this study reveals the unique metabolic profile of PF-cultivated rice and high-lights the potential of PFs to accelerate the breeding of crops such as rice,offering an innovative agricul-tural strategy to support food security in the face of global population growth and climate change.
基金supported by NSFC Shiptime Sharing Project(Nos.42349302,and 42149905)the Hubei Provincial Natural Science Foundation of China(No.2024AFB515)+4 种基金the National Natural Science Foundation of China(Nos.42207173,41831280,and 42176071)the National Key R&D Program of China(No.2024YFC3082500)the Shandong Provincial Natural Science Foundation of China(No.ZR2022QD002)the Shandong Provincial Taishan Scholar Construction Project(No.tsqn202507091)the Shandong Provincial Young Innovators Team(No.2024KJH183).
文摘Low–angle submarine landslides pose a greater threat to offshore infrastructure compared to those with steep sliding angles.Understanding the preparation and triggering mechanism of these low–angle submarine landslides remains a significant challenge.This study focuses on a deformed low–angle submarine landslide in the shelf–slope break of the Pearl River Mouth Basin,South China Sea,integrating sedimentology,geophysics,and geotechnology to investigate potential failure mechanisms.The architecture and deformation characteristics of the submarine landslide were elucidated by analyzing multibeam and seismic data.Within the context of the regional geological history and tectonic framework,this study focuses on the factors(e.g.,rapid sedimentation,fluid activity,and earthquakes)that potentially contributed to the submarine slope failure.Furthermore,a series of stability evaluations considering the effects of rapid sedimentation and earthquakes was conducted.Our findings indicate that the most probable triggering mechanism involves the combined effects of sedimentation controlled by sea–level fluctuations,high–pressure gas activity,and seismic events.The high–pressure gas,which acts as a long–term preconditioning factor by elevating pore pressures and reducing shear resistance within the sediment,accumulated beneath the upper and middle sections of the low–permeability stratum that was formed during sea–level rise and ultimately evolved into the sliding mass.The overpressure generated by gas accumulation predisposed the submarine slope to instability,and a frequent or moderate earthquake ultimately initiated local failure.This study enhances the mechanistic understanding of low–angle slope failures in the shelf–slope break zone and provides critical insights for assessing marine hazard risks.
基金support of the National Natural Science Foundation of China(No.52171063).
文摘Weathering steel exhibits excellent corrosion resistance and is widely used in bridges,towers,railways,highways,and other engineering projects that are exposed to the atmosphere for long periods of time.However,before the formation of stable rust layers,weathering steel is prone to liquid rust sagging and spattering,leading to environmental pollution and city appearance concerns.These factors limit the application and development of weathering steel.In this study,a rapid and environmentally friendly method was de-veloped by introducing alloying elements,specifically investigating the role of Sn in the rapid stabilization of rust layers in marine atmo-spheric environments.The rust layer formed on weathering low-alloy steel exposed to prolonged outdoor conditions and laboratory im-mersion experiments was explored using electron probe micro-analyzer(EPMA),micro-Raman,X-ray photoelectron spectroscopy(XPS),and electrochemical measurements.Results showed an optimal synergistic effect between Sn and Cr,which facilitated the accelerated densification of the rust layer.This beneficial effect enhanced the capability of the rust layer to resist Cl^(-)erosion and improved the protec-tion performance of the rust layer.
基金the National Key R&D Program of China(No.2021YFA0715900)the National Natural Science Foundation of China(No.41831279)+2 种基金the Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks(No.ZDSYS20220606100604008)the Guangdong Province Bureau of Education(No.2020KCXTD006)the Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control(No.2023B1212060002).
文摘Rapid screening of inorganic arsenic(iAs)in groundwater used for drinking by hundreds of millions of mostly rural residents worldwide is crucial for health protection.Most commercial field test kits are based on the Gutzeit reaction that uses mercury-based reagents for color development,an environmental concern that increasingly limits its utilization.This study further improves the Molybdenum Blue(MB)colorimetric method to allow for faster screening with more stable reagents.More importantly,a portable three-channel colorimeter is developed for screening iAs relative to the WHO drinking water guideline value(10μg/L).Adding the reducing reagents in sequence not only prolongs the storage time to>7 days,but also accelerates the color development time to 6 min in conjunction with lowering the H_(2)SO_(4) concentration in chromogenic reagents.The optimal pH ranges from 1.2 to 1.3 and is achieved by acidifying groundwater to 1%(V/V)HCl.With detection limits of 3.7μg/L for inorganic arsenate(iAs(V))and 3.8μg/L for inorganic arsenite(iAs(Ⅲ)),testing groundwater with-10μg/L of As has a precision<20%.The method works well for a range of phosphate concentrations of 48-950μg/L(0.5-10μmol/L).Concentrations of total_iAs(6-300μg/L),iAs(V)(6-230μg/L)and iAs(Ⅲ)(0-170μg/L)for 14 groundwater samples from Yinchuan Plain,Pearl River Delta,and Jianghan Plain,are in excellent agreements(linear regression slope:0.969-1.029)with the benchmark methods.The improved chemistry here lays the foundation for the MB colorimetric method to become a commercially viable screening tool,with further engineering and design improvement of the colorimeter.
基金Supported by Beijing Hospitals Authority Youth Programme,No.QML20200505.
文摘BACKGROUND Esophageal squamous cell carcinoma is a major histological subtype of esophageal cancer.Many molecular genetic changes are associated with its occurrence.Raman spectroscopy has become a new method for the early diagnosis of tumors because it can reflect the structures of substances and their changes at the molecular level.AIM To detect alterations in Raman spectral information across different stages of esophageal neoplasia.METHODS Different grades of esophageal lesions were collected,and a total of 360 groups of Raman spectrum data were collected.A 1D-transformer network model was proposed to handle the task of classifying the spectral data of esophageal squamous cell carcinoma.In addition,a deep learning model was applied to visualize the Raman spectral data and interpret their molecular characteristics.RESULTS A comparison among Raman spectral data with different pathological grades and a visual analysis revealed that the Raman peaks with significant differences were concentrated mainly at 1095 cm^(-1)(DNA,symmetric PO,and stretching vibration),1132 cm^(-1)(cytochrome c),1171 cm^(-1)(acetoacetate),1216 cm^(-1)(amide III),and 1315 cm^(-1)(glycerol).A comparison among the training results of different models revealed that the 1Dtransformer network performed best.A 93.30%accuracy value,a 96.65%specificity value,a 93.30%sensitivity value,and a 93.17%F1 score were achieved.CONCLUSION Raman spectroscopy revealed significantly different waveforms for the different stages of esophageal neoplasia.The combination of Raman spectroscopy and deep learning methods could significantly improve the accuracy of classification.
基金supported by the National Natural Science Foundation of China (12250012,42250101)the Macao Foundation。
文摘The core-surface flow is crucial for understanding the dynamics of the Earth's outer core and geomagnetic secular variations.Conventional core flow models often use a single set of spherical harmonic coefficients to represent the flow both inside and outside the tangent cylinder,inherently imposing continuity across the tangent cylinder around the solid inner core.To address this limitation,we present a core-surface flow inversion framework based on physics-informed neural networks.This framework employs distinct neural network representations for the flow inside and outside the tangent cylinder,allowing for discontinuities as the flow crosses the tangent cylinder.Additionally,it incorporates secular acceleration data to constrain the temporal evolution of the core flow.Using this inversion framework,we derive a new core-surface flow model spanning 2001 to 2024 from a geomagnetic model,incorporating the latest magnetic data from Swarm satellites and Macao Science Satellite-1.The recovered model reveals persistent large-scale circulation linked to westward drift,significant temporal variations in the equatorial Pacific,and distinct jet-like structures at the poles.The inversion also reveals a large-scale wave pattern in equatorial azimuthal flow acceleration,corresponding to observed geomagnetic jerks and likely resulting from quasi-geostrophic magneto-Coriolis waves.Additionally,the framework infers small-scale magnetic fields at the core-mantle boundary,highlighting split flux concentrations and localized high-latitude patches.
基金supported by the National Key Research and Development Program of China(No.2021YFC2400703)the Key Scientific and Technological Research Projects in Henan Province(Nos.232102311155 and 232102230106)Zhengzhou University Major Project Cultivation Special Project(No.125-32214076).
文摘Drug-eluting magnesium(Mg)alloy stents have a slower degradation rate and lower restenosis rate compared with uncoated stents,demonstrating good clinical efficacy.However,the release of anti-hyperplasia drugs from coatings delays endothelial tissue repair,thus leading to late stent thrombosis.To address these issues,a dual self-healed coating with various biological properties was fabricated on magnesium fluoride/polydopamine(MgF_(2)/PDA)-treated Mg alloys by spraying-assisted layer-by-layer(LBL)self-assembly of chitosan(CS),gallic acid(GA),and 3-aminobenzeneboronic acid-modified hyaluronic acid(HA-ABBA).The LBL coating,approximately 1.50μm thick,exhibited a uniform morphology with good adhesion strength(~1065 mN).The annual corrosion rate(Pi)of LBL samples was~1400 times slower than that of the Mg substrate,due to the physical barrier function provided by MgF_(2)/PDA layers and the dual self-healed ability of LBL layers.The rapid self-healing ability(with a healing period of~4 h under dynamic/static conditions)resulted from the synergistic interplay between the recombination of diverse chemical bonds within the LBL coating and the coordination of LBL-released GA with Mg2+,as corroborated by computer simulations.Compared with the drug-eluting coatings,the LBL sample demonstrated substantial advantages in anti-oxidation,anti-denaturation of fibrinogen,anti-platelet adhesion,anti-inflammation,anti-hyperplasia,and promoted-endothelialization.These benefits effectively address the limitations associated with drug-eluting coatings.
基金National Key Research and Development Program(2021YFB3401101)。
文摘Short process forming techniques for brazing and soldering materials can shorten the process,improve product quality,and increase production efficiency,which has received much attention from welding researchers.This review mainly summarized the research reports on short process forming techniques for brazing and soldering materials.Firstly,the traditional process and its shortcomings were presented.Secondly,the latest research of short process forming technologies,such as continuous casting technique,atomization powder technique,solder ball forming technique,and rapid solidification technique,was summarized,and the traditional forming performance of several brazing and soldering materials was introduced.Finally,the current restrictions and research trends of short process forming technique for brazing and solder materials were put forward,providing theoretical guidance and reference for related research and technique development in brazing and soldering field.
文摘BACKGROUND At the end of December 2019,the world faced severe acute respiratory syndrome-coronavirus 2(SARS-CoV-2),which led to the outbreak of coronavirus disease 2019(COVID-19),associated with respiratory issues.This virus has shown significant challenges,especially for senior citizens,patients with other underlying illnesses,or those with a sedentary lifestyle.Serological tests conducted early on have helped identify how the virus is transmitted and how to curb its spread.The study hypothesis was that the rapid serological test for SARS-CoV-2 antibodies could indicate the immunoreactive profile during the COVID-19 pandemic in a university population.AIM To conduct active surveillance for serological expression of anti-SARS-CoV-2 antibodies in individuals within a university setting during the COVID-19 pandemic.METHODS This sectional study by convenience sampling was conducted in a large university in Niteroi-RJ,Brazil,from March 2021 to July 2021.The study population consisted of students,faculty,and administrative staff employed by the university.A total of 3433 faculty members,60703 students,and 3812 administrative staff were invited to participate.Data were gathered through rapid serological tests to detect immunoglobulin(Ig)M and IgG against SARS-CoV-2.Theχ²or Fisher's exact test was used to conduct statistical analysis.A 0.20 significance level was adopted for variable selection in a multiple logistic regression model to evaluate associations.RESULTS A total of 1648 individuals were enrolled in the study.The proportion of COVID-19 positivity was 164/1648(9.8%).The adjusted logistic model indicate a positive association between the expression of IgM or IgG and age[odds ratio(OR)=1.16,95%CI:1.02-1.31](P<0.0024),individuals who had been in contact with a COVID-19-positive case(OR=3.49,95%CI:2.34-5.37)(P<0.001),those who had received the COVID-19 vaccine(OR=2.33,95%CI:1.61-3.35)(P<0.001)and social isolation(OR=0.59,95%CI:0.41-0.84)(P<0.004).The likelihood of showing a positive result increased by 16%with every ten-year increment.Conversely,adherence to social distancing measures decreased the likelihood by 41%.CONCLUSION These findings evidenced that the population became more exposed to the virus as individuals discontinued social distancing practices,thereby increasing the risk of infection for themselves.
