As an important link in the development of modern quality education,art education is one of the methods to guide students to have a diversified vision.Under the background of multiculturalism,we need to explore the co...As an important link in the development of modern quality education,art education is one of the methods to guide students to have a diversified vision.Under the background of multiculturalism,we need to explore the connotation and value of art education with the concept of“three highs and four new,”so that students can realize interdisciplinary and cross-cultural cognition through an immersive experience and practical operation in a wide range of multicultural situations,and to develop the knowledge of art education with the concept of“three highs and four new.”Based on the multicultural background,this paper focuses on the integration of multiculturalism into the reform practice of“student-centered”in colleges and universities,so as to cultivate art talents adapted to the multicultural background,in order to achieve the great mission of“three highs and four new”and better lead the innovative development of art education in colleges and universities.展开更多
Polymerflooding is an effective method widely applied for enhancing oil recovery(EOR)by reducing the mobility ratio between theinjected water and crude oil.However,traditional polymers encounter challenges in high sali...Polymerflooding is an effective method widely applied for enhancing oil recovery(EOR)by reducing the mobility ratio between theinjected water and crude oil.However,traditional polymers encounter challenges in high salinity reservoirs due to their salt sensitivity.Toovercome this challenge,we synthesized a zwitterion polymer(PAMNS)with salt-induced tackifying property through copolymerization ofacrylamide and a zwitterion monomer,methylacrylamide propyl-N,N-dimethylbutylsulfonate(NS).NS monomer is obtained from thereaction between 1,4-butanesultone and dimethylamino propyl methylacrylamide.In this study,the rheological properties,salt responsiveness,and EOR efficiency of PAMNS were evaluated.Results demonstrate that PAMNS exhibits desirable salt-induced tackifyingcharacteristics,with viscosity increasing up to 2.4 times as the NaCl concentration reaches a salinity of 30×10^(4)mg L^(-1).Furthermore,highvalence ions possess a much stronger effect on enhancing viscosity,manifested as Mg^(2+)>Ca^(2+)>Na^(+).Molecular dynamics simulations(MD)andfluid dynamics experiment results demonstrate that PAMNS molecules exhibit a more stretched state and enhanced intermolecularassociations in high-salinity environments.It is because of the salt-induced tackifying,PAMNS demonstrates superior performance inpolymerflooding experiments under salinity ranges from 5×10^(4)mg L^(-1)to 20×10^(4)mg L^(-1),leading to 10.38–19.83%higher EOR thantraditional polymers.展开更多
Based on the reanalysis data of global 500hPa geopotential height (NCEP NCAR CDAS-1) and tropical Pacific SSTs, the characteristics of global subtropical highs and their response to tropical eastern Pacific SST are i...Based on the reanalysis data of global 500hPa geopotential height (NCEP NCAR CDAS-1) and tropical Pacific SSTs, the characteristics of global subtropical highs and their response to tropical eastern Pacific SST are investigated. Results show that global subtropical highs respond to SST consistently. Subtropical high intensity correlates to the 3 months leading SST maximally. The relationship between SST and 500hPa height stands out in low latitudes. The time for 500hPa height reaching maximuxn correlation to SST is 2 months later in latitude of 10 degree and 9 months in latitude of 30 degree than equatorial zone. And the response of atmospheric circulation over extratropic performs as wave train, and the response is more significant in the condition of warmer SST. Persistence of SSTs and subtropical highs changes obviously from season to season. Minimum persistence of subtropical highs in September and October may relate to the low persistence of SSTs in August and September.展开更多
Money flowing into commodities-one analyst called it a "commodity pandemonium" - powered cotton futures to new rally highs last week in holiday-shortened trading.
The effects of the sea surface temperature (SST) anomalies in the tropical western Pacific on the atmospheric circulation anomalies over East Asia are simulated by the IAP-GCM with an observed and idealized distributi...The effects of the sea surface temperature (SST) anomalies in the tropical western Pacific on the atmospheric circulation anomalies over East Asia are simulated by the IAP-GCM with an observed and idealized distributions of the SST anomalies in the tropical western Pacific,respectively.Firstly,the atmospheric circulation anomalies during July and August,1980 are simulated by three anomalous experiments including the global SST anomaly experiment,the tropical SST anomaly experiment and the extratropical SST anomaly experiment,using the observed SST anomalies in 1980.It is shown that the SST anomalies in the tropical ocean greatly influence the formation and maintenance of the blocking high over the northeastern Asia,and may play a more important role than the SST anomalies in the extratropical ocean in the influence on the atmospheric circulation anomalies.Secondly,the effects of the SST anomalies in the tropical western Pacific on the atmospheric circulation anomalies over East Asia are also simulated with an idealized distribution of the SST anomalies in the tropical western Pacific.The simulated results show that the negative anomalies of SST in the tropical western Pacific have a significant effect on the formation and maintenance of the blocking high over the northeastern Asia.展开更多
Previous work showed that some tropical cyclones （TCs） in the western Pacific Ocean undergo sudden track reversal, and the onset, maintenance and decay of blocking highs （BHs） coexisted with 19 of the studied TCs ...Previous work showed that some tropical cyclones （TCs） in the western Pacific Ocean undergo sudden track reversal, and the onset, maintenance and decay of blocking highs （BHs） coexisted with 19 of the studied TCs with sudden track reversal. In these cases, the phase relations between the BH, the continental high （CH）, the subtropical high （SH） and the suddenly reversed TCs could be classified into types A, B, C and D. Types C and D were the focal point of this follow-up study, in which Typhoon Pabuk （2007） and Lupit （2009） were employed to conduct numerical simulations. The results showed that the reversed tracks of Pabuk （2007） and Lupit （2009） could have been affected by the BH, particularly in terms of the turning location and the trend of movement after turning. Specifically, the two main features for Pabuk （2007） in the BH perturbations were the deflection of its turning point and a distinct anticlockwise rotation. Lupit （2009） deviated to the southwest and finally made landfall in the Philippines, or experienced further eastward movement, in the perturbed BH. The impact mechanisms can be attributed to the change in the vorticity field transported from the BH, leading to an intensity variation of midlatitude systems. BHs may have a positive feedback effect on the strength of the westerly trough （TR）, as indicated by a weakened and strengthened TR corresponding to negative and positive BH perturbations, respectively.展开更多
BACKGROUND High-sensitivity cardiac troponin(hs-cTn)levels are frequently elevated in elderly patients presenting to the emergency department for non-cardiac events.However,most studies on the role of elevated hs-cTn ...BACKGROUND High-sensitivity cardiac troponin(hs-cTn)levels are frequently elevated in elderly patients presenting to the emergency department for non-cardiac events.However,most studies on the role of elevated hs-cTn in elderly populations have investigated the prognostic value of hs-cTn in patients with a specific diagnosis or have assessed the relationship between hs-cTn and comorbidities.AIM To investigate the in-hospital prognosis of consecutive elderly patients admitted to the Internal Medicine Department with acute non-cardiac events and increased hs-cTnI levels.METHODS In this retrospective study,we selected patients who were aged≥65 years and admitted to the Internal Medicine Department of our hospital between January 2019 and December 2019 for non-cardiac reasons.Eligible patients were those who had hs-cTnI concentrations≥100 ng/L.We investigated the independent predictors of in-hospital mortality by multivariable logistic regression analysis.RESULTS One hundred and forty-six patients(59%female)were selected with an age range from 65 to 100(mean±SD:85.4±7.61)years.The median hs-cTnI value was 284.2 ng/L.For 72(49%)patients the diagnosis of hospitalization was an infectious disease.The overall in-hospital mortality was 32%(47 patients).Individuals who died did not have higher hs-cTnI levels compared with those who were discharged alive(median:314.8 vs 282.5 ng/L;P=0.565).There was no difference in mortality in patients with infectious vs non-infectious disease(29%vs 35%).Multivariable analysis showed that age(OR 1.062 per 1 year increase,95%CI:1.000-1.127;P=0.048)and creatinine levels(OR 2.065 per 1 mg/dL increase,95%CI:1.383-3.085;P<0.001)were the only independent predictors of death.Mortality was 49%in patients with eGFR<30 mL/min/1.73 m2.CONCLUSION Myocardial injury is a malignant condition in elderly patients admitted to the hospital for non-cardiac reasons.The presence of severe renal impairment is a marker of extremely high in-hospital mortality.展开更多
According to the characteristics of complex terrain and bad geological conditions in the southwest mountainous area of China, it is proposed that cast-in situ double-block ballastless track with layers and blocks stru...According to the characteristics of complex terrain and bad geological conditions in the southwest mountainous area of China, it is proposed that cast-in situ double-block ballastless track with layers and blocks structure should be adopted preferentially in the subgrade section of high-speed railway, which is conducive to the construction, prolongation of service life and maintenance of the ballastless track. Based on the finite element model, the dynamic performance, structural strength and stability of double-block ballastless track under high earthquake-intensity action are analyzed. The analysis shows that the relative displacement between the base slab of ballastless track and the subgrade may occur under 9 degree earthquake action. A new CRTS double-block ballastless track structure with a concave-convex structure between the base slab and the subgrade is proposed in the subgrade section, and its additional stress and relative displacement under earthquake are analyzed. The results show that the additional stress and relative displacement of the new ballastless track structure and the subgrade under 9-degree earthquake actions are small, which meet the high stability requirements of high-speed railway.展开更多
Dual carbon goals are closely related to high-quality green development.The government has required that dual car-bon goals be included in ecological civilization construction’s overall layout.Achieving carbon peak a...Dual carbon goals are closely related to high-quality green development.The government has required that dual car-bon goals be included in ecological civilization construction’s overall layout.Achieving carbon peak and carbon neutrality is a broad and profound systemic economic and social transformation.China is facing the“three highs and one short”challenges and requires the“five carbon implementations”to achieve dual carbon goals.The core of dual carbon goals is a new round of industrial competition,and the world is laying out dual carbon goals as the starting point and competing for a new round of technological high ground.展开更多
BACKGROUND Addressing the growing challenge of hospitalizing chronic multimorbid patients,this study examines the strain these conditions impose on healthcare systems at a local level,focusing on a pilot program.Chron...BACKGROUND Addressing the growing challenge of hospitalizing chronic multimorbid patients,this study examines the strain these conditions impose on healthcare systems at a local level,focusing on a pilot program.Chronic diseases and complex patients require comprehensive management strategies to reduce healthcare burdens and improve patient outcomes.If proven effective,this pilot model has the potential to be replicated in other healthcare settings to enhance the management of chronic multimorbid patients.AIM To evaluate the effectiveness of the high complexity unit(HCU)in managing chronic multimorbid patients through a multidisciplinary care model and to compare it with standard hospital care.METHODS The study employed a descriptive longitudinal approach,analyzing data from the Basic Minimum Data Set(BMDS)to compare hospitalization variables among the HCU,the Internal Medicine Service,and other services at Antequera Hospital throughout 2022.The HCU,designed for patients with complex chronic conditions,integrates a patient-centered model emphasizing multidisciplinary care and continuity post-discharge.RESULTS The study employed a descriptive longitudinal approach,analyzing data from the BMDS to compare hospitalization variables among the HCU,the Internal Medicine Service,and other services at Antequera Hospital throughout 2022.The HCU,designed for patients with complex chronic conditions,integrates a patient-centered model emphasizing multidisciplinary care and continuity post-discharge.CONCLUSION This study demonstrates the effectiveness of the HCU in managing patients with complex chronic diseases through a multidisciplinary approach.The coordinated care provided by the HCU results in improved patient outcomes,reduced unnecessary hospitalizations,and better management of patient complexity.The superiority of the HCU compared to standard care is evident in key outcomes such as fewer readmissions and higher patient satisfaction,reinforcing its value as a model of care to be replicated.展开更多
Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage p...Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage poses challenges for the performance and stability of air electrodes.In this work,a novel high-entropy perovskite oxide La_(0.2)Pr_(0.2)Gd_(0.2)Sm_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF)is proposed and investigated as an air electrode in RSOC.The electrochemical behavior of HE-LSCF was studied as an air electrode in both fuel cell and electrolysis modes.The polarization impedance(Rp)of the HE-LSCF electrode is only 0.25Ω·cm^(2) at 800℃ in an air atmosphere.Notably,at an electrolytic voltage of 2 V and a temperature of 800℃,the current density reaches up to 1.68 A/cm^(2).The HE-LSCF air electrode exhibited excellent reversibility and stability,and its electrochemical performance remains stable after 100 h of reversible operation.With these advantages,HE-LSCF is shown to be an excellent air electrode for RSOC.展开更多
Based on the daily Japanese 55-yr reanalysis data,this study analyzes the maintenance mechanism for 53 boreal winter blocking highs around the Ural Mountains(UBHs)during 1958-2018 based on the atmospheric energy budge...Based on the daily Japanese 55-yr reanalysis data,this study analyzes the maintenance mechanism for 53 boreal winter blocking highs around the Ural Mountains(UBHs)during 1958-2018 based on the atmospheric energy budget equations.After decomposing the circulation into background flow,low-frequency anomalies,and high-frequency eddies,it was found that the interaction between the background flow and low-frequency anomalies is conducive to the maintenance of the UBHs.Due to the southwestward gradient in the climatological mean air temperature over the Eurasian continent,it is easy for the air temperature anomalies as well as the wind velocity anomalies in the middle and lower troposphere induced by the UBHs to facilitate the positive conversion of baroclinic energy associated with the background flow into the UBHs.Likewise,the conversion of barotropic energy associated with the background flow is also evident in the upper troposphere,in which the climatological mean westerlies have evident southward gradient to the northwest of Lake Baikal and southwestward gradient over Barents Sea.Note that the conversion of baroclinic energy associated with the background flow is dominant throughout the lifecycle of UBHs,acting as the major contributor to the maintenance of the UBHs.Although transient eddies facilitate maintenance of the UBHs via positive conversion of barotropic energy in the middle and upper troposphere,they hinder the maintenance of UBHs via negative conversion of baroclinic energy in the lower troposphere.The diabatic heating anomalies tend to counteract the local air temperature anomalies in the middle and lower troposphere,which damps the available potential energy of UBHs and acts as a negative contributor to the UBHs.展开更多
The reform stems from honesty and determination. Since 2005, organ donation and transplantation in China has undergone thorough reform, which complies with legislation requirements and ethical principles established b...The reform stems from honesty and determination. Since 2005, organ donation and transplantation in China has undergone thorough reform, which complies with legislation requirements and ethical principles established by the World Health Organization(WHO). Reform in China has demonstrated the unwavering confidence and utmost determination of the Chinese government and the Chinese transplantation community. The year 2015 marked a historic turning point when voluntary donations from Chinese citizens became the sole legitimate source for organ transplantation. Since 2015, China has gradually established and refined the “Chinese Mode” and “China System” for organ donation and transplantation, fulfilling its political pledge of reform, and has garnered international recognition, and fostered a social culture which promotes organ donation. This article reviewed the history of reform on organ donation and transplantation in China, presented a new pattern of establishment of organ donation system in the new era of the country, and the direction of advances in the future.展开更多
Lightweight high/medium-entropy alloys(H/MEAs)possess attractive properties such as high strength-to-weight ratios,however,their limited room-temperature tensile ductility hinders their widespread engi-neering impleme...Lightweight high/medium-entropy alloys(H/MEAs)possess attractive properties such as high strength-to-weight ratios,however,their limited room-temperature tensile ductility hinders their widespread engi-neering implementation,for instance in aerospace structural components.This work achieved a transfor-mative improvement of room-temperature tensile ductility in Ti-V-Zr-Nb MEAs with densities of 5.4-6.5 g/cm3,via ingenious composition modulation.Through the systematic co-adjustment of Ti and V contents,an intrinsic ductility mechanism was unveiled,manifested by a transition from predominant intergranular brittle fracture to pervasive ductile dimpled rupture.Notably,the modulated deformation mechanisms evolved from solitary slip toward collaborative multiple slip modes,without significantly compromising strength.Compared to equimolar Ti-V-Zr-Nb,a(Ti1.5V)3ZrNb composition demonstrated an impressive 360%improvement in elongation while sustaining a high yield strength of around 800 MPa.Increasing Ti and V not only purified the grain boundaries by reducing detrimental phases,but also tai-lored the deformation dislocation configurations.These insights expanded the applicability of lightweight HEAs to areas demanding combined high strength and ductility.展开更多
GH4169 joints manufactured by Linear Friction Welding(LFW)are subjected to tensile test and stair-case method to evaluate the High Cycle Fatigue(HCF)performance at 650℃.The yield and ultimate tensile strengths are 58...GH4169 joints manufactured by Linear Friction Welding(LFW)are subjected to tensile test and stair-case method to evaluate the High Cycle Fatigue(HCF)performance at 650℃.The yield and ultimate tensile strengths are 582 MPa and 820 MPa,respectively.The HCF strength of joint reaches 400 MPa,which is slightly lower than that of Base Metal(BM),indicating reliable quality of this type of joint.The microstructure observation results show that all cracks initiate at the inside of specimens and transfer into deeper region with decrease of external stress,and the crack initiation site is related with microhardness of matrix.The Electron Backscattered Diffraction(EBSD)results of the observed regions with different distances to fracture show that plastic deformation plays a key role in HCF,and the Schmid factor of most grains near fracture exceeds 0.4.In addition,the generation of twins plays a vital role in strain concentration release and coordinating plastic deformation among grains.展开更多
Up-and-coming high-temperature materials,refractory high entropy alloys,are suffering from lower oxidation resistance,restricting their applications in the aerospace field.In this study,two novel treatments of Al-depo...Up-and-coming high-temperature materials,refractory high entropy alloys,are suffering from lower oxidation resistance,restricting their applications in the aerospace field.In this study,two novel treatments of Al-deposited and remelted were developed to refine the microstructure and enhance the oxidation resistance of refractory high entropy alloy using electron beam freeform fabrication(EBF3).Finer and short-range ordering structures were observed in the remelted sample,whereas the Al-deposited sample showcased the formation of silicide and intermetallic phases.High-temperature cyclic and isothermal oxidation tests at 1000℃ were carried out.The total weight gain after 60 h of cyclic oxidation decreased by 17.49%and 30.46%for the remelted and deposited samples,respectively,compared to the as-cast state.Oxidation kinetics reveal an evident lower mass gain and oxidation rate in the treated samples.A multilayer oxide consisting of TiO_(2)+Al_(2)O_(3)+SiO_(2)+AlNbO_(4) was studied for its excellent oxidation resistance.The oxidation behavior of rutile,corundum and other oxides was analyzed using first principles calculations and chemical defect analysis.Overall,this research,which introduces novel treatments,offers promising insights for enhancing the inherent oxidation resistance of refractory high entropy alloys.展开更多
The Early Cambrian Yuertusi Formation(Є_(1)y)in the Tarim Basin of China deposits a continuously developed suite of organic-rich black mudstones,which constitute an important source of oil and gas reservoirs in the Pa...The Early Cambrian Yuertusi Formation(Є_(1)y)in the Tarim Basin of China deposits a continuously developed suite of organic-rich black mudstones,which constitute an important source of oil and gas reservoirs in the Paleozoic.However,its hydrocarbon generation and evolution characteristics and resource potential have long been constrained by deeply buried strata and previous research.In this paper,based on the newly obtained ultra-deep well drilling data,the hydrocarbon generation and expulsion model ofЄ_(1)y shale was established by using data-driven Monte Carlo simulation,upon which the hydrocarbon generation,expulsion,and retention amounts were calculated by using the diagenetic method.The research indicates that theЄ_(1)y shale reaches the hydrocarbon generation and expulsion threshold at equivalent vitrinite reflectances of 0.46%and 0.72%,respectively.The cumulative hydrocarbon generation is 68.88×10^(10)t,the cumulative hydrocarbon expulsion is 35.59×10^(10)t,and the cumulative residual hydrocarbon is 33.29×10^(10)t.This paper systematically and quantitatively calculates the hydrocarbon expulsion at various key geological periods for theЄ_(1)y source rocks in the study area for the first time,more precisely confirming that the black shale of theЄ_(1)y is the most significant source rock contributing to the marine oil and gas resources in the Tarim Basin,filling the gap in hydrocarbon expulsion calculation in the study area,and providing an important basis for the formation and distribution of Paleozoic hydrocarbon reservoirs.The prospect of deep ultra-deep oil and gas exploration in the Tarim Basin is promising.Especially,the large area of dolomite reservoirs under the Cambrian salt and source rock interiors are the key breakthrough targets for the next exploration in the Tarim Basin.展开更多
This study presents a machine learning-based method for predicting fragment velocity distribution in warhead fragmentation under explosive loading condition.The fragment resultant velocities are correlated with key de...This study presents a machine learning-based method for predicting fragment velocity distribution in warhead fragmentation under explosive loading condition.The fragment resultant velocities are correlated with key design parameters including casing dimensions and detonation positions.The paper details the finite element analysis for fragmentation,the characterizations of the dynamic hardening and fracture models,the generation of comprehensive datasets,and the training of the ANN model.The results show the influence of casing dimensions on fragment velocity distributions,with the tendencies indicating increased resultant velocity with reduced thickness,increased length and diameter.The model's predictive capability is demonstrated through the accurate predictions for both training and testing datasets,showing its potential for the real-time prediction of fragmentation performance.展开更多
In the context of global warming,it is anticipated that both the intensity and the frequency of future global extreme high precipitation(EHP)and extreme high temperature(EHT)events will increase.To evaluate the future...In the context of global warming,it is anticipated that both the intensity and the frequency of future global extreme high precipitation(EHP)and extreme high temperature(EHT)events will increase.To evaluate the future extreme climate changes in the Asian arid region and Tibetan Plateau,this study applied the NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP-CMIP6)to assess the changes in EHP(Rx5d and R95pTOT)and EHT(TX90p and TXx)under different emission scenarios in the 21st century.Findings suggest that both the frequency and the intensity of the extreme indices will increase,exhibiting accelerated growth under higher emission scenarios,particularly under the SSP5-8.5 emission scenario.It is suggested that the growth of EHT and EHP in the early subperiod of the 21st century(2026-2045)will be relatively moderate,with small differences between different emission scenarios.However,by the middle subperiod of the 21st century(2041-2060),the differences between different emission scenarios will become larger than the 2035s and the growth will become more intense.In western central Asia,TX90p,TXx,Rx5d,and R95pTOT increase by 9.7%-14.2%(13.3%-24.7%),1.3℃-1.7℃(1.6℃-2.7℃),6.5%-8.9%(8.2%-8.8%),and 18.1%-27.0%(25.6%-30.0%)by the early(middle)subperiod;in eastern central Asia,TX90p,TXx,Rx5d,and R95pTOT increase 8.1%-12.0%(11.3%-21.1%),1.4℃-1.8℃(1.9℃-2.9℃),7.4%-9.7%(10.4%-13.8%),and 20.2%-29.3%(32.0%-40.8%)by the early(middle)subperiod;and over the Tibetan Plateau,TX90p,TXx,Rx5d,and R95pTOT increase 12.5%-17.4%(17.0%-31.0%),1.2℃-1.5℃(1.6℃-2.5℃),7.2%-10.0%(9.9%-15.0%),and 26.6%-33.1%(36.1%-55.3%)by the early(middle)subperiod.展开更多
Metal Additive Manufacturing(MAM) technology has become an important means of rapid prototyping precision manufacturing of special high dynamic heterogeneous complex parts. In response to the micromechanical defects s...Metal Additive Manufacturing(MAM) technology has become an important means of rapid prototyping precision manufacturing of special high dynamic heterogeneous complex parts. In response to the micromechanical defects such as porosity issues, significant deformation, surface cracks, and challenging control of surface morphology encountered during the selective laser melting(SLM) additive manufacturing(AM) process of specialized Micro Electromechanical System(MEMS) components, multiparameter optimization and micro powder melt pool/macro-scale mechanical properties control simulation of specialized components are conducted. The optimal parameters obtained through highprecision preparation and machining of components and static/high dynamic verification are: laser power of 110 W, laser speed of 600 mm/s, laser diameter of 75 μm, and scanning spacing of 50 μm. The density of the subordinate components under this reference can reach 99.15%, the surface hardness can reach 51.9 HRA, the yield strength can reach 550 MPa, the maximum machining error of the components is 4.73%, and the average surface roughness is 0.45 μm. Through dynamic hammering and high dynamic firing verification, SLM components meet the requirements for overload resistance. The results have proven that MEM technology can provide a new means for the processing of MEMS components applied in high dynamic environments. The parameters obtained in the conclusion can provide a design basis for the additive preparation of MEMS components.展开更多
基金2022 Hunan Provincial General Higher Education School Teaching Reform Research Key Project“Research and Practice of Innovative Art Talent Cultivation Mode in Local Comprehensive Colleges and Universities Under the Strategy of‘Three Highs and Four New’”(Project number:HNJG-2022-0108)。
文摘As an important link in the development of modern quality education,art education is one of the methods to guide students to have a diversified vision.Under the background of multiculturalism,we need to explore the connotation and value of art education with the concept of“three highs and four new,”so that students can realize interdisciplinary and cross-cultural cognition through an immersive experience and practical operation in a wide range of multicultural situations,and to develop the knowledge of art education with the concept of“three highs and four new.”Based on the multicultural background,this paper focuses on the integration of multiculturalism into the reform practice of“student-centered”in colleges and universities,so as to cultivate art talents adapted to the multicultural background,in order to achieve the great mission of“three highs and four new”and better lead the innovative development of art education in colleges and universities.
基金support of the National Natural Science Foundation of China(No.52120105007)the National Key Research and Development Program of China(2019Y FA0708700)are gratefully acknowledged.
文摘Polymerflooding is an effective method widely applied for enhancing oil recovery(EOR)by reducing the mobility ratio between theinjected water and crude oil.However,traditional polymers encounter challenges in high salinity reservoirs due to their salt sensitivity.Toovercome this challenge,we synthesized a zwitterion polymer(PAMNS)with salt-induced tackifying property through copolymerization ofacrylamide and a zwitterion monomer,methylacrylamide propyl-N,N-dimethylbutylsulfonate(NS).NS monomer is obtained from thereaction between 1,4-butanesultone and dimethylamino propyl methylacrylamide.In this study,the rheological properties,salt responsiveness,and EOR efficiency of PAMNS were evaluated.Results demonstrate that PAMNS exhibits desirable salt-induced tackifyingcharacteristics,with viscosity increasing up to 2.4 times as the NaCl concentration reaches a salinity of 30×10^(4)mg L^(-1).Furthermore,highvalence ions possess a much stronger effect on enhancing viscosity,manifested as Mg^(2+)>Ca^(2+)>Na^(+).Molecular dynamics simulations(MD)andfluid dynamics experiment results demonstrate that PAMNS molecules exhibit a more stretched state and enhanced intermolecularassociations in high-salinity environments.It is because of the salt-induced tackifying,PAMNS demonstrates superior performance inpolymerflooding experiments under salinity ranges from 5×10^(4)mg L^(-1)to 20×10^(4)mg L^(-1),leading to 10.38–19.83%higher EOR thantraditional polymers.
基金supported by National Natural Science Foundation of China (49635190).
文摘Based on the reanalysis data of global 500hPa geopotential height (NCEP NCAR CDAS-1) and tropical Pacific SSTs, the characteristics of global subtropical highs and their response to tropical eastern Pacific SST are investigated. Results show that global subtropical highs respond to SST consistently. Subtropical high intensity correlates to the 3 months leading SST maximally. The relationship between SST and 500hPa height stands out in low latitudes. The time for 500hPa height reaching maximuxn correlation to SST is 2 months later in latitude of 10 degree and 9 months in latitude of 30 degree than equatorial zone. And the response of atmospheric circulation over extratropic performs as wave train, and the response is more significant in the condition of warmer SST. Persistence of SSTs and subtropical highs changes obviously from season to season. Minimum persistence of subtropical highs in September and October may relate to the low persistence of SSTs in August and September.
文摘Money flowing into commodities-one analyst called it a "commodity pandemonium" - powered cotton futures to new rally highs last week in holiday-shortened trading.
基金This study was supported by the major applied project 'KY85-10' of Chinese Academy of Sciences
文摘The effects of the sea surface temperature (SST) anomalies in the tropical western Pacific on the atmospheric circulation anomalies over East Asia are simulated by the IAP-GCM with an observed and idealized distributions of the SST anomalies in the tropical western Pacific,respectively.Firstly,the atmospheric circulation anomalies during July and August,1980 are simulated by three anomalous experiments including the global SST anomaly experiment,the tropical SST anomaly experiment and the extratropical SST anomaly experiment,using the observed SST anomalies in 1980.It is shown that the SST anomalies in the tropical ocean greatly influence the formation and maintenance of the blocking high over the northeastern Asia,and may play a more important role than the SST anomalies in the extratropical ocean in the influence on the atmospheric circulation anomalies.Secondly,the effects of the SST anomalies in the tropical western Pacific on the atmospheric circulation anomalies over East Asia are also simulated with an idealized distribution of the SST anomalies in the tropical western Pacific.The simulated results show that the negative anomalies of SST in the tropical western Pacific have a significant effect on the formation and maintenance of the blocking high over the northeastern Asia.
基金supported by the National Natural Science Foundation of China(Grant No.41230421)the 973 project(Grant Nos.2015CB452802 and 2013CB430101)of the Ministry of Science and Technology,China
文摘Previous work showed that some tropical cyclones （TCs） in the western Pacific Ocean undergo sudden track reversal, and the onset, maintenance and decay of blocking highs （BHs） coexisted with 19 of the studied TCs with sudden track reversal. In these cases, the phase relations between the BH, the continental high （CH）, the subtropical high （SH） and the suddenly reversed TCs could be classified into types A, B, C and D. Types C and D were the focal point of this follow-up study, in which Typhoon Pabuk （2007） and Lupit （2009） were employed to conduct numerical simulations. The results showed that the reversed tracks of Pabuk （2007） and Lupit （2009） could have been affected by the BH, particularly in terms of the turning location and the trend of movement after turning. Specifically, the two main features for Pabuk （2007） in the BH perturbations were the deflection of its turning point and a distinct anticlockwise rotation. Lupit （2009） deviated to the southwest and finally made landfall in the Philippines, or experienced further eastward movement, in the perturbed BH. The impact mechanisms can be attributed to the change in the vorticity field transported from the BH, leading to an intensity variation of midlatitude systems. BHs may have a positive feedback effect on the strength of the westerly trough （TR）, as indicated by a weakened and strengthened TR corresponding to negative and positive BH perturbations, respectively.
文摘BACKGROUND High-sensitivity cardiac troponin(hs-cTn)levels are frequently elevated in elderly patients presenting to the emergency department for non-cardiac events.However,most studies on the role of elevated hs-cTn in elderly populations have investigated the prognostic value of hs-cTn in patients with a specific diagnosis or have assessed the relationship between hs-cTn and comorbidities.AIM To investigate the in-hospital prognosis of consecutive elderly patients admitted to the Internal Medicine Department with acute non-cardiac events and increased hs-cTnI levels.METHODS In this retrospective study,we selected patients who were aged≥65 years and admitted to the Internal Medicine Department of our hospital between January 2019 and December 2019 for non-cardiac reasons.Eligible patients were those who had hs-cTnI concentrations≥100 ng/L.We investigated the independent predictors of in-hospital mortality by multivariable logistic regression analysis.RESULTS One hundred and forty-six patients(59%female)were selected with an age range from 65 to 100(mean±SD:85.4±7.61)years.The median hs-cTnI value was 284.2 ng/L.For 72(49%)patients the diagnosis of hospitalization was an infectious disease.The overall in-hospital mortality was 32%(47 patients).Individuals who died did not have higher hs-cTnI levels compared with those who were discharged alive(median:314.8 vs 282.5 ng/L;P=0.565).There was no difference in mortality in patients with infectious vs non-infectious disease(29%vs 35%).Multivariable analysis showed that age(OR 1.062 per 1 year increase,95%CI:1.000-1.127;P=0.048)and creatinine levels(OR 2.065 per 1 mg/dL increase,95%CI:1.383-3.085;P<0.001)were the only independent predictors of death.Mortality was 49%in patients with eGFR<30 mL/min/1.73 m2.CONCLUSION Myocardial injury is a malignant condition in elderly patients admitted to the hospital for non-cardiac reasons.The presence of severe renal impairment is a marker of extremely high in-hospital mortality.
基金supported by China Railway Eryuan Engineering Group Co.,Ltd。
文摘According to the characteristics of complex terrain and bad geological conditions in the southwest mountainous area of China, it is proposed that cast-in situ double-block ballastless track with layers and blocks structure should be adopted preferentially in the subgrade section of high-speed railway, which is conducive to the construction, prolongation of service life and maintenance of the ballastless track. Based on the finite element model, the dynamic performance, structural strength and stability of double-block ballastless track under high earthquake-intensity action are analyzed. The analysis shows that the relative displacement between the base slab of ballastless track and the subgrade may occur under 9 degree earthquake action. A new CRTS double-block ballastless track structure with a concave-convex structure between the base slab and the subgrade is proposed in the subgrade section, and its additional stress and relative displacement under earthquake are analyzed. The results show that the additional stress and relative displacement of the new ballastless track structure and the subgrade under 9-degree earthquake actions are small, which meet the high stability requirements of high-speed railway.
文摘Dual carbon goals are closely related to high-quality green development.The government has required that dual car-bon goals be included in ecological civilization construction’s overall layout.Achieving carbon peak and carbon neutrality is a broad and profound systemic economic and social transformation.China is facing the“three highs and one short”challenges and requires the“five carbon implementations”to achieve dual carbon goals.The core of dual carbon goals is a new round of industrial competition,and the world is laying out dual carbon goals as the starting point and competing for a new round of technological high ground.
基金Supported by Fundación Progreso y Salud,No.AP-0306-2022-C3-F2.
文摘BACKGROUND Addressing the growing challenge of hospitalizing chronic multimorbid patients,this study examines the strain these conditions impose on healthcare systems at a local level,focusing on a pilot program.Chronic diseases and complex patients require comprehensive management strategies to reduce healthcare burdens and improve patient outcomes.If proven effective,this pilot model has the potential to be replicated in other healthcare settings to enhance the management of chronic multimorbid patients.AIM To evaluate the effectiveness of the high complexity unit(HCU)in managing chronic multimorbid patients through a multidisciplinary care model and to compare it with standard hospital care.METHODS The study employed a descriptive longitudinal approach,analyzing data from the Basic Minimum Data Set(BMDS)to compare hospitalization variables among the HCU,the Internal Medicine Service,and other services at Antequera Hospital throughout 2022.The HCU,designed for patients with complex chronic conditions,integrates a patient-centered model emphasizing multidisciplinary care and continuity post-discharge.RESULTS The study employed a descriptive longitudinal approach,analyzing data from the BMDS to compare hospitalization variables among the HCU,the Internal Medicine Service,and other services at Antequera Hospital throughout 2022.The HCU,designed for patients with complex chronic conditions,integrates a patient-centered model emphasizing multidisciplinary care and continuity post-discharge.CONCLUSION This study demonstrates the effectiveness of the HCU in managing patients with complex chronic diseases through a multidisciplinary approach.The coordinated care provided by the HCU results in improved patient outcomes,reduced unnecessary hospitalizations,and better management of patient complexity.The superiority of the HCU compared to standard care is evident in key outcomes such as fewer readmissions and higher patient satisfaction,reinforcing its value as a model of care to be replicated.
基金supported by Fundamental Research Funds for the Central Universities(2023KYJD1008)the Science Research Projects of the Anhui Higher Education Institutions of China(2022AH051582).
文摘Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage poses challenges for the performance and stability of air electrodes.In this work,a novel high-entropy perovskite oxide La_(0.2)Pr_(0.2)Gd_(0.2)Sm_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF)is proposed and investigated as an air electrode in RSOC.The electrochemical behavior of HE-LSCF was studied as an air electrode in both fuel cell and electrolysis modes.The polarization impedance(Rp)of the HE-LSCF electrode is only 0.25Ω·cm^(2) at 800℃ in an air atmosphere.Notably,at an electrolytic voltage of 2 V and a temperature of 800℃,the current density reaches up to 1.68 A/cm^(2).The HE-LSCF air electrode exhibited excellent reversibility and stability,and its electrochemical performance remains stable after 100 h of reversible operation.With these advantages,HE-LSCF is shown to be an excellent air electrode for RSOC.
基金Supported by the National Natural Science Foundation of China(42088101,42025502,41575057,and 41975063)Qing Lan Project of Jiangsu Province,China。
文摘Based on the daily Japanese 55-yr reanalysis data,this study analyzes the maintenance mechanism for 53 boreal winter blocking highs around the Ural Mountains(UBHs)during 1958-2018 based on the atmospheric energy budget equations.After decomposing the circulation into background flow,low-frequency anomalies,and high-frequency eddies,it was found that the interaction between the background flow and low-frequency anomalies is conducive to the maintenance of the UBHs.Due to the southwestward gradient in the climatological mean air temperature over the Eurasian continent,it is easy for the air temperature anomalies as well as the wind velocity anomalies in the middle and lower troposphere induced by the UBHs to facilitate the positive conversion of baroclinic energy associated with the background flow into the UBHs.Likewise,the conversion of barotropic energy associated with the background flow is also evident in the upper troposphere,in which the climatological mean westerlies have evident southward gradient to the northwest of Lake Baikal and southwestward gradient over Barents Sea.Note that the conversion of baroclinic energy associated with the background flow is dominant throughout the lifecycle of UBHs,acting as the major contributor to the maintenance of the UBHs.Although transient eddies facilitate maintenance of the UBHs via positive conversion of barotropic energy in the middle and upper troposphere,they hinder the maintenance of UBHs via negative conversion of baroclinic energy in the lower troposphere.The diabatic heating anomalies tend to counteract the local air temperature anomalies in the middle and lower troposphere,which damps the available potential energy of UBHs and acts as a negative contributor to the UBHs.
文摘The reform stems from honesty and determination. Since 2005, organ donation and transplantation in China has undergone thorough reform, which complies with legislation requirements and ethical principles established by the World Health Organization(WHO). Reform in China has demonstrated the unwavering confidence and utmost determination of the Chinese government and the Chinese transplantation community. The year 2015 marked a historic turning point when voluntary donations from Chinese citizens became the sole legitimate source for organ transplantation. Since 2015, China has gradually established and refined the “Chinese Mode” and “China System” for organ donation and transplantation, fulfilling its political pledge of reform, and has garnered international recognition, and fostered a social culture which promotes organ donation. This article reviewed the history of reform on organ donation and transplantation in China, presented a new pattern of establishment of organ donation system in the new era of the country, and the direction of advances in the future.
基金supported by the National Natural Science Foundation of China(Nos.51925103,52271149,52171159)the Innovation Program of Shanghai Municipal Education Commission(No.2021-01-07-00-09-E00114)+5 种基金the Natural Science Foundation of Shanghai(22ZR1422500)the Innovation Program of Shanghai Science and Technology(No.23520760700)the Aviation Foundation(No.2023Z0530S6004)the Fund of the State Key Laboratory of Solidification Processing in NWPU(No.SKLSP202221)the financial support from Program 173(No.2020-JCIQ-ZD-186-01)the Space Utilization System of China Manned Space Engineering(No.KJZ-YY-NCL08).
文摘Lightweight high/medium-entropy alloys(H/MEAs)possess attractive properties such as high strength-to-weight ratios,however,their limited room-temperature tensile ductility hinders their widespread engi-neering implementation,for instance in aerospace structural components.This work achieved a transfor-mative improvement of room-temperature tensile ductility in Ti-V-Zr-Nb MEAs with densities of 5.4-6.5 g/cm3,via ingenious composition modulation.Through the systematic co-adjustment of Ti and V contents,an intrinsic ductility mechanism was unveiled,manifested by a transition from predominant intergranular brittle fracture to pervasive ductile dimpled rupture.Notably,the modulated deformation mechanisms evolved from solitary slip toward collaborative multiple slip modes,without significantly compromising strength.Compared to equimolar Ti-V-Zr-Nb,a(Ti1.5V)3ZrNb composition demonstrated an impressive 360%improvement in elongation while sustaining a high yield strength of around 800 MPa.Increasing Ti and V not only purified the grain boundaries by reducing detrimental phases,but also tai-lored the deformation dislocation configurations.These insights expanded the applicability of lightweight HEAs to areas demanding combined high strength and ductility.
基金supported by the National Natural Science Foundation of China(Nos.52074228,52305420,and 51875470)the China Postdoctoral Science Foundation(No.2023M742830)。
文摘GH4169 joints manufactured by Linear Friction Welding(LFW)are subjected to tensile test and stair-case method to evaluate the High Cycle Fatigue(HCF)performance at 650℃.The yield and ultimate tensile strengths are 582 MPa and 820 MPa,respectively.The HCF strength of joint reaches 400 MPa,which is slightly lower than that of Base Metal(BM),indicating reliable quality of this type of joint.The microstructure observation results show that all cracks initiate at the inside of specimens and transfer into deeper region with decrease of external stress,and the crack initiation site is related with microhardness of matrix.The Electron Backscattered Diffraction(EBSD)results of the observed regions with different distances to fracture show that plastic deformation plays a key role in HCF,and the Schmid factor of most grains near fracture exceeds 0.4.In addition,the generation of twins plays a vital role in strain concentration release and coordinating plastic deformation among grains.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFF0609000)National Natural Science Foundation of China(Grant Nos.52171034 and 52101037)Postdoctoral Fellowship Program of CPSFara(No.GZB20230944).
文摘Up-and-coming high-temperature materials,refractory high entropy alloys,are suffering from lower oxidation resistance,restricting their applications in the aerospace field.In this study,two novel treatments of Al-deposited and remelted were developed to refine the microstructure and enhance the oxidation resistance of refractory high entropy alloy using electron beam freeform fabrication(EBF3).Finer and short-range ordering structures were observed in the remelted sample,whereas the Al-deposited sample showcased the formation of silicide and intermetallic phases.High-temperature cyclic and isothermal oxidation tests at 1000℃ were carried out.The total weight gain after 60 h of cyclic oxidation decreased by 17.49%and 30.46%for the remelted and deposited samples,respectively,compared to the as-cast state.Oxidation kinetics reveal an evident lower mass gain and oxidation rate in the treated samples.A multilayer oxide consisting of TiO_(2)+Al_(2)O_(3)+SiO_(2)+AlNbO_(4) was studied for its excellent oxidation resistance.The oxidation behavior of rutile,corundum and other oxides was analyzed using first principles calculations and chemical defect analysis.Overall,this research,which introduces novel treatments,offers promising insights for enhancing the inherent oxidation resistance of refractory high entropy alloys.
基金supported by the CNPC Science and Technology Major Project of the Fourteenth Five-Year Plan(2021DJ0101)the National Natural Science Foundation of China(U19B600302,41872148)。
文摘The Early Cambrian Yuertusi Formation(Є_(1)y)in the Tarim Basin of China deposits a continuously developed suite of organic-rich black mudstones,which constitute an important source of oil and gas reservoirs in the Paleozoic.However,its hydrocarbon generation and evolution characteristics and resource potential have long been constrained by deeply buried strata and previous research.In this paper,based on the newly obtained ultra-deep well drilling data,the hydrocarbon generation and expulsion model ofЄ_(1)y shale was established by using data-driven Monte Carlo simulation,upon which the hydrocarbon generation,expulsion,and retention amounts were calculated by using the diagenetic method.The research indicates that theЄ_(1)y shale reaches the hydrocarbon generation and expulsion threshold at equivalent vitrinite reflectances of 0.46%and 0.72%,respectively.The cumulative hydrocarbon generation is 68.88×10^(10)t,the cumulative hydrocarbon expulsion is 35.59×10^(10)t,and the cumulative residual hydrocarbon is 33.29×10^(10)t.This paper systematically and quantitatively calculates the hydrocarbon expulsion at various key geological periods for theЄ_(1)y source rocks in the study area for the first time,more precisely confirming that the black shale of theЄ_(1)y is the most significant source rock contributing to the marine oil and gas resources in the Tarim Basin,filling the gap in hydrocarbon expulsion calculation in the study area,and providing an important basis for the formation and distribution of Paleozoic hydrocarbon reservoirs.The prospect of deep ultra-deep oil and gas exploration in the Tarim Basin is promising.Especially,the large area of dolomite reservoirs under the Cambrian salt and source rock interiors are the key breakthrough targets for the next exploration in the Tarim Basin.
基金supported by Poongsan-KAIST Future Research Center Projectthe fund support provided by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(Grant No.2023R1A2C2005661)。
文摘This study presents a machine learning-based method for predicting fragment velocity distribution in warhead fragmentation under explosive loading condition.The fragment resultant velocities are correlated with key design parameters including casing dimensions and detonation positions.The paper details the finite element analysis for fragmentation,the characterizations of the dynamic hardening and fracture models,the generation of comprehensive datasets,and the training of the ANN model.The results show the influence of casing dimensions on fragment velocity distributions,with the tendencies indicating increased resultant velocity with reduced thickness,increased length and diameter.The model's predictive capability is demonstrated through the accurate predictions for both training and testing datasets,showing its potential for the real-time prediction of fragmentation performance.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program[grant number 2019QZKK0101]。
文摘In the context of global warming,it is anticipated that both the intensity and the frequency of future global extreme high precipitation(EHP)and extreme high temperature(EHT)events will increase.To evaluate the future extreme climate changes in the Asian arid region and Tibetan Plateau,this study applied the NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP-CMIP6)to assess the changes in EHP(Rx5d and R95pTOT)and EHT(TX90p and TXx)under different emission scenarios in the 21st century.Findings suggest that both the frequency and the intensity of the extreme indices will increase,exhibiting accelerated growth under higher emission scenarios,particularly under the SSP5-8.5 emission scenario.It is suggested that the growth of EHT and EHP in the early subperiod of the 21st century(2026-2045)will be relatively moderate,with small differences between different emission scenarios.However,by the middle subperiod of the 21st century(2041-2060),the differences between different emission scenarios will become larger than the 2035s and the growth will become more intense.In western central Asia,TX90p,TXx,Rx5d,and R95pTOT increase by 9.7%-14.2%(13.3%-24.7%),1.3℃-1.7℃(1.6℃-2.7℃),6.5%-8.9%(8.2%-8.8%),and 18.1%-27.0%(25.6%-30.0%)by the early(middle)subperiod;in eastern central Asia,TX90p,TXx,Rx5d,and R95pTOT increase 8.1%-12.0%(11.3%-21.1%),1.4℃-1.8℃(1.9℃-2.9℃),7.4%-9.7%(10.4%-13.8%),and 20.2%-29.3%(32.0%-40.8%)by the early(middle)subperiod;and over the Tibetan Plateau,TX90p,TXx,Rx5d,and R95pTOT increase 12.5%-17.4%(17.0%-31.0%),1.2℃-1.5℃(1.6℃-2.5℃),7.2%-10.0%(9.9%-15.0%),and 26.6%-33.1%(36.1%-55.3%)by the early(middle)subperiod.
基金funded by the National Natural Science Foundation of China Youth Fund(Grant No.62304022)Science and Technology on Electromechanical Dynamic Control Laboratory(China,Grant No.6142601012304)the 2022e2024 China Association for Science and Technology Innovation Integration Association Youth Talent Support Project(Grant No.2022QNRC001).
文摘Metal Additive Manufacturing(MAM) technology has become an important means of rapid prototyping precision manufacturing of special high dynamic heterogeneous complex parts. In response to the micromechanical defects such as porosity issues, significant deformation, surface cracks, and challenging control of surface morphology encountered during the selective laser melting(SLM) additive manufacturing(AM) process of specialized Micro Electromechanical System(MEMS) components, multiparameter optimization and micro powder melt pool/macro-scale mechanical properties control simulation of specialized components are conducted. The optimal parameters obtained through highprecision preparation and machining of components and static/high dynamic verification are: laser power of 110 W, laser speed of 600 mm/s, laser diameter of 75 μm, and scanning spacing of 50 μm. The density of the subordinate components under this reference can reach 99.15%, the surface hardness can reach 51.9 HRA, the yield strength can reach 550 MPa, the maximum machining error of the components is 4.73%, and the average surface roughness is 0.45 μm. Through dynamic hammering and high dynamic firing verification, SLM components meet the requirements for overload resistance. The results have proven that MEM technology can provide a new means for the processing of MEMS components applied in high dynamic environments. The parameters obtained in the conclusion can provide a design basis for the additive preparation of MEMS components.
