We read with great interest Deng et al.’s study 1 comparing sextant(6-core)and 12-core systematic biopsy in theMRI-targeted era,which valuably challenges the“more cores=higher accuracy”dogma by proposing a precisio...We read with great interest Deng et al.’s study 1 comparing sextant(6-core)and 12-core systematic biopsy in theMRI-targeted era,which valuably challenges the“more cores=higher accuracy”dogma by proposing a precision sampling strategy based on prostate cancer’s spatial distribution,aligning with personalized diagnosis trends.展开更多
The Martian core mainly contains iron,nickel and some light elements.However,controversies remain about the structure and chemical composition of the Martian core due to a lack of samples and marsquake data.Recently,t...The Martian core mainly contains iron,nickel and some light elements.However,controversies remain about the structure and chemical composition of the Martian core due to a lack of samples and marsquake data.Recently,the InSight lander collected long-term marsquake data,which improved the Martian interior structure model.B ased on the preliminary analysis of marsquake data,Mars has a molten liquid core with a radius of around 1700 km.As the Martian core has a smaller density and lower temperature than pure iron at corresponding pressure and temperature conditions,some light elements are introduced to reduce the density and liquidus temperature.With various methods for seismic analysis,in-situ high-pressure and high-temperature experiments,and first-principal calculations,the Martian core composition and evolution models have been updated in the past few years.Here,we review those studies on the light elements in the Martian core from four aspects including(1)high-temperature and high-pressure experiments,(2)marsquake data,(3)mineral physics model with molecular dynamics simulations and(4)cosmochemistry investigation.We discussed the effect of different light elements on the Martian core s density,sound velocity and liquidus temperature.Moreover,the review examines the varieties,abundances and forms of light elements in the Martian core.展开更多
Within contemporary healthcare systems, professional identity among specialized nurses serves as a pivotal intrinsic factor influencing the development of their core competencies. This review synthesizes existing rese...Within contemporary healthcare systems, professional identity among specialized nurses serves as a pivotal intrinsic factor influencing the development of their core competencies. This review synthesizes existing research, revealing that professional identity positively impacts the development of core competencies through multiple pathways, including psychological drive, behavioral facilitation, teamwork, and career stability. Building on this analysis, this paper proposes systematic enhancement strategies from four dimensions: education and training, organizational environment, cultural development, and individual growth, aiming to provide a reference for nursing practice and professional development.展开更多
Low reactivity and appropriate wettability between molten superalloys and ceramic materials are crucial for the production of high-quality superalloy castings.The sessile-drop experiment was employed to systematically...Low reactivity and appropriate wettability between molten superalloys and ceramic materials are crucial for the production of high-quality superalloy castings.The sessile-drop experiment was employed to systematically investigate the interfacial reaction and wettability between the 4777DS1 superalloy and SiO_(2)-based ceramic core at various temperatures(1,480℃,1,500℃,1,520℃,and 1,550℃).The wetting behavior and interfacial reaction products at different temperatures were analyzed by scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),and X-ray diffraction(XRD).The interfacial reaction process and products were discussed,and the thermodynamic behavior and interfacial reaction mechanisms were elucidated.The results demonstrate that the wetting behavior and interfacial reaction between the 4777DS1 alloy and the ceramic core are significantly influenced by temperature.The wettability angle exhibits a trend of initial decrease followed by an increase with rising temperature,reaching a maximum of 139°at 1,480℃,indicating poorer wettability of the 4777DS1 superalloy with the ceramic core and better casting properties at this specific temperature.The most intense interfacial reaction occurs at 1,520℃,resulting in the formation of the main interfacial reaction products such as Al_(2)O_(3),SiO_(2),and HfO_(2).Additionally,some crystal-like products rich in Si and Hf distribute on the reaction layer.展开更多
In permafrost regions of the QinghaiXizang Plateau,embankments of the Qinghai-Xizang Highway and Qinghai-Xizang Railway experiencing roadside water accumulation exhibit more pronounced engineering deteriorations.A wid...In permafrost regions of the QinghaiXizang Plateau,embankments of the Qinghai-Xizang Highway and Qinghai-Xizang Railway experiencing roadside water accumulation exhibit more pronounced engineering deteriorations.A widely accepted view is that the accumulated water adjacent to the embankment possesses substantial thermal energy,which accelerates the degradation-even disappearance-of the underlying permafrost.Moreover,the presence of roadside water keeps the embankment soil in a persistently high-moisture state,thereby making the frozen-soil embankment more susceptible to deformation under traffic loading.However,in the permafrost regions of the QinghaiXizang Plateau,deteriorations of embankments affected by roadside water are more commonly manifested as undulating pavement surfaces,and extensive crack networks appear on the embankment crest even where thermosyphons are installed.These manifestations are not fully consistent with the deterioration mechanisms proposed by existing viewpoints.We propose the hypothesis that temperature gradients,formed due to the freezing and thawing processes between the roadside wateraffected soil and the roadbed soil,lead to moisture migration under the influence of temperature gradients,resulting in frost heave and thaw settlement in the roadbed soil.To validate this hypothesis,we conducted the following investigations sequentially.Initially,we selected a roadbed with a thermosyphon(TPCT)system,which has a significant cooling effect,as the study object.By analyzing the temperature monitoring data of the roadbed section,the temperature variance was calculated to identify the time nodes where the temperature gradient of the roadbed soil was maximum and minimum.Subsequently,corresponding roadbed temperature distribution maps were drawn,illustrating the changes in the temperature and position of the lowtemperature core near the TPCT over time.Furthermore,using small-scale indoor model experiments,we qualitatively concluded that moisture in the soil migrates toward the TPCT due to the temperature gradient.Thereafter,combining borehole water content data and precipitation data from the sloped terrain construction site,the formation mechanisms and timing characteristics of roadside water accumulation were analyzed.Ultimately,by integrating the ground temperature data,air temperature data,roadside water formation mechanisms,and the operating characteristics of the TPCT,it was concluded that roadside water,while in a thawed state during TPCT operation,acts as a supplementary source for moisture migration in the roadbed soil.This migration leads to cracking in the TPCT roadbed.Therefore,this study reveals a novel damage mechanism:asynchronous freeze-thaw processes induce temperature gradients,which drive the migration of roadside water into the roadbed and are responsible for the cracking damage.展开更多
[Objectives]To investigate the clinical efficacy of core stability training combined with conventional rehabilitation in the functional recovery of patients suffering from chronic low back pain.[Methods]A randomized c...[Objectives]To investigate the clinical efficacy of core stability training combined with conventional rehabilitation in the functional recovery of patients suffering from chronic low back pain.[Methods]A randomized controlled trial design was employed in this study.Ninety patients with chronic low back pain were recruited and randomly assigned to either a control group(n=45),which received conventional rehabilitation,or an experimental group(n=45),which received conventional rehabilitation combined with core stability training.Both groups underwent treatment for 6 weeks.Assessments were conducted using the visual analogue scale(VAS),Oswestry disability index(ODI),and finger-to-floor test prior to treatment,6 weeks following treatment,and during the follow-up period,respectively.[Results]Prior to treatment,no statistically significant differences were observed between the two patient groups in terms of general information and various baseline measurements(P>0.05).Following 6 weeks of treatment and throughout the follow-up period,both groups demonstrated significant improvements in VAS scores,ODI scores,and lumbar anteflexion range of motion compared to baseline measurements(P<0.05).Notably,the magnitude of improvement in the experimental group exceeded that of the control group,with this inter-group difference reaching statistical significance(P<0.05).No serious adverse reactions were reported during the treatment process.[Conclusions]Core stability training combined with conventional rehabilitation can significantly enhance the alleviation of pain and functional impairments in patients suffering from chronic low back pain.This approach holds valuable implications for the optimization of rehabilitation treatment protocols.展开更多
IR64 is an elite Xian/indica variety developed by International Rice Research Institute(IRRl)in 1985,which has been the most widely grown variety and core breeding parent in South/Southeast Asia(Mackill and Khush,2018...IR64 is an elite Xian/indica variety developed by International Rice Research Institute(IRRl)in 1985,which has been the most widely grown variety and core breeding parent in South/Southeast Asia(Mackill and Khush,2018).IR64 has been utilized to develop stress-tolerant(such as drought-adapted and submergenceresistant)near-isogenic lines,underscoring its great potential in agricultural genomics(Tanaka et al.,2020).展开更多
As an essential component of terrestrial carbon sinks,lake sediments store vast quantities of both organic carbon(OC)and inorganic carbon(IC).However,the spatiotemporal relationship between the OC and IC in sediments ...As an essential component of terrestrial carbon sinks,lake sediments store vast quantities of both organic carbon(OC)and inorganic carbon(IC).However,the spatiotemporal relationship between the OC and IC in sediments and their responses to climate change remains unclear,which hinders the comprehensive understanding of carbon dynamics in lake ecosystems.This study systematically analyzes the spatiotemporal dynamics of carbon burial across the Tibetan Plateau using surface sediments from 119 lakes and sediment cores from four representative lakes.Results show that OC burial dominates in humid and dry sub-humid zones,whereas IC burial prevails in arid and semi-arid regions.This distribution reflects the influences of lake and catchment productivity and water chemistry on OC and IC patterns.Sediment cores confirm that these factors have consistently affected lake carbon burial over the past century.Specifically,in humid and dry sub-humid zones,increased precipitation enhances watershed productivity and sedimentation,promoting coupled OC and IC burial.In arid and semi-arid regions,wind-driven dust supplies nutrients and alters water chemistry,also driving coupled OC and IC burial.Based on these findings,the carbon sink capacity of lake sediments on the Tibetan Plateau is projected to increase under the“warming and wetting”trend.展开更多
General Information Journal of Chinese Pharmaceutical Sciences(JCPS)is a peer-reviewed bimonthly journal founded in 1992.JCPS has been indexed in the Core Journals of China's science and technology field.At presen...General Information Journal of Chinese Pharmaceutical Sciences(JCPS)is a peer-reviewed bimonthly journal founded in 1992.JCPS has been indexed in the Core Journals of China's science and technology field.At present it has been included by Chemical Abstracts(CA),UIPD,Index of Copurnicus(IC),CABI,SCOPUS,JSTChina,DOAJ,EBSCO,CSTPCD,Chinese Science Citation Database(CSCD),the Chinese National Knowledge Infrastructure(CNKI)and World Journal Clout Index(WJCI)Report.展开更多
The purpose of this study is to gain perspectives on introducing IBCTL(International Baccalaureate Certificate in Teaching and Learning)into graduate school of teacher education in Japan,which are currently providing ...The purpose of this study is to gain perspectives on introducing IBCTL(International Baccalaureate Certificate in Teaching and Learning)into graduate school of teacher education in Japan,which are currently providing advanced teacher training programs aimed at cultivating student agency,a comprehensive set of skills necessary for children living in the future,as advocated by the Organisation for Economic Co-operation and Development(OECD)Education 2030 Project.To achieve this goal,I examined the curriculum and structure that are important for IB teacher training and the introduction of IBCTL.I attempted to achieve this goal by examining the curriculum being developed at a graduate school of teacher education attempting to implement IBCTL and the creation of a syllabus based on that curriculum through lesson planning.As a result,I examined the curriculum and structure as a perspective for introducing IBCTL into graduate school of teacher education in Japan,where advanced teacher training is required.I found that a core curriculum and structure that incorporates the core of the IBCTL into the core of graduate school of teacher education programs is important for implementing an IB education that is aligned with the advancement of teacher training and the development of student agency.展开更多
In this study,copper extraction from low-grade oxide-sulfide ores was investigated using a leaching method combined with response surface methodology(RSM)to optimize operational conditions and assess leaching kinetics...In this study,copper extraction from low-grade oxide-sulfide ores was investigated using a leaching method combined with response surface methodology(RSM)to optimize operational conditions and assess leaching kinetics.Given copper's extensive industrial applications,sustainable recovery from low-grade ores is critical.Five key parameters-acid concentration,leaching time,particle size,temperature,and solids percentage-were identified as major influences on copper recovery.The results revealed that leaching time and solids percentage,along with interactions between temperature-time and temperature-solids percentage,had the most significant effects.Optimal conditions for 80% copper recovery while minimizing iron recovery below 3% included an acid concentration of 1.21 mol L^(-1),a leaching time of 108 min,a particle size of 438μm,a temperature of 45℃,and a solids percentage of 18.2%.Leaching kinetics were analyzed using shrinking core models,with the Dickinson model best describing the process,showing an activation energy of 32.63 kJ mol^(-1),indicative of mixed diffusion and chemical reaction control.The final kinetic model effectively predicted the influence of key parameters.These findings highlight the importance of optimizing process variables and selecting suitable kinetic models to enhance extraction efficiency,reduce costs,and improve sustainability in copper recovery.展开更多
Rational design of non-noble electrocatalysts with high performance for oxygen evolution reaction(OER)still remains a challenge.In this study,a ZIF-derived electrocatalyst(Co@Fe-P)with a core-shell structure is design...Rational design of non-noble electrocatalysts with high performance for oxygen evolution reaction(OER)still remains a challenge.In this study,a ZIF-derived electrocatalyst(Co@Fe-P)with a core-shell structure is designed by using Co-compounds as the core and PO_(4)^(3-)decorated Fe-compounds as the shell.The inner Co-core and outer Fe-shell are connected through Co-O-Fe and Fe-O-P linkage.The Co@Fe-P electrocatalyst exhibits an enhanced performance for OER with a low overpotential(280 mV),low Tafel slope(41.9 mV dec^(-1))at 10 mA cm^(-2),and a 60-h durability.The electron transfer from the CoOOH-core to the FeOOH-shell is greatly facilitated,which improves the OER activity of Co@Fe-P kinetically.Theoretical calculations indicate that the interaction of Co-O-Fe and Fe-O-P in Co@Fe-P reduces the overlap between the O 2p and Fe 3d orbitals,which greatly facilitates the transformation from*OH to*O during the OER process via the adsorbate evolution mechanism(AEM)pathway.This finding provides insight for the design of efficient electrocatalysts for OER.展开更多
The GRACE(Gravity Recovery and Climate Experiment)space mission recorded temporal variation characteristics of the global gravity field at decadal timescales.The gravity data have been shown to capture the dynamics of...The GRACE(Gravity Recovery and Climate Experiment)space mission recorded temporal variation characteristics of the global gravity field at decadal timescales.The gravity data have been shown to capture the dynamics of flows within the outer core and their effects on the core-mantle boundary.We first aim to remove global surface process gravity signals from the GRACE data.We then construct the global core magnetic field according to the CHAOS-7 model.Finally,we apply the blind source separation method to decompose the processed gravity signals and core magnetic signals and compute the power spectral density of the gravity and magnetic field signals by using the Lomb-Scargle periodogram approach.We have discovered a signal cycle(of~6 years)in the principal components of the core magnetic and gravity signals,potentially as a result of deep Earth processes.The main principal components of the core magnetic and gravity signals reveal that the variation trends in the second-order time derivative of the core magnetic field are similar to those in the gravity field.After 2014,the second-order time derivative of the core magnetic field exhibited linear and rapid change characteristics,which were the same as the change in the gravity field and are consistent with existing research results.展开更多
The development of human settlements(HS)in coastal cities is an integral component and a vital pathway toward building a strong marine power.It is also an essential requirement for achieving the coordinated developmen...The development of human settlements(HS)in coastal cities is an integral component and a vital pathway toward building a strong marine power.It is also an essential requirement for achieving the coordinated development of HS systems in these cities.In this study,we constructed an indicator system to analyze the coupling coordination degree(CCD)of HS systems in coastal cities in the Bohai Rim region of China(CCBRR).This study is based on five systems and employs methods such as the entropy weight method,CCD model,spatial trend surface analysis,and geographic detector to examine comprehensively the spatial and temporal patterns of CCD in 17 CCBRR during the period 2011–2022,as well as to explore their influencing factors.The findings are as follows:(1)Temporally,the CCD is high and exhibits a slow increasing trend,with distinct stage characteristics.(2)Spatially,the distribution of CCD reveals a“one core,many strengths”structural pattern.(3)Moreover,socioeconomic factors are the dominant force driving the CCD of the internal HS systems in the CCBRR.(4)Finally,we constructed a coupling coordination driving mechanism for HS in the CCBRR with the aim of providing scientific references and path choices for the high-quality and coordinated development of the CCBRR along with the implementation of the new quality productive forces regionalization.展开更多
Liquid core reduction(LCR)technology,originally developed for continuous thin-slab casting,allows space for a submerged entry nozzle in a mold while improving production efficiency.Recent experimental attempts explore...Liquid core reduction(LCR)technology,originally developed for continuous thin-slab casting,allows space for a submerged entry nozzle in a mold while improving production efficiency.Recent experimental attempts explore the implementation of LCR in regular slab casting processes.However,regular slabs(2–3 times thicker than thin slabs)face critical challenges in terms of excessive deformation and stress concentration under external forces,which induce intermediate cracks and thus hinder successful LCR adoption in regular slab production.This study evaluates the feasibility of LCR for producing regular slabs and identifies optimal reduction parameters to prevent crack initiation.A three-dimensional thermal–mechanical coupled model is proposed using the finite element method(FEM),integrated with the equivalent replacement liquid steel(ERLS)method and the normalized Cockcroft–Latham damage model,to achieve quantitative prediction of intermediate crack risk during the LCR process.The ERLS model simulates the extrusion flow and expulsion behavior of the liquid core,and its accuracy is validated against actual production measurements.To identify the critical damage value leading to intermediate crack initiation,this study conducts a consistency analysis between high-temperature tensile tests and FEM-based simulations using damage models.Based on this value,crack prediction is performed for Q355 slabs with cross-sectional dimensions of 170 mm×1450 mm.Using the prediction results,an optimal reduction scheme is determined,wherein the second segment accounts for 50%of the total reduction,the third segment for 32.5%,and the fourth segment for 17.5%,with the theoretical value of maximum reduction being 34 mm.These results provide actionable guidelines for the potential implementation of LCR in regular slab-casting systems.展开更多
The paper presents the results of geomechanical and CT-based studies of deformation,fracture and filtration processes in reservoir rocks of the Arctic shelf gas condensate field.The experimental study combines(i)deter...The paper presents the results of geomechanical and CT-based studies of deformation,fracture and filtration processes in reservoir rocks of the Arctic shelf gas condensate field.The experimental study combines(i)determination of mechanical properties,(ii)true triaxial physical modeling of near-wellbore filtration and geomechanical processes,(iii)triaxial sand production studies,and(iv)digital CT-analysis of the rock matrix and sand particles.Based on true triaxial physical modeling,the relationships between permeability,rock deformation,and stresses around a horizontal well during drawdown were determined.Hollow cylinder-type tests were used to determine the stress conditions for sand release initiation,the intensity of sand production under varying stress states,and the total volume of sand produced.Digital particle size analysis of the matrix and released sand provided insights into the dominant mechanisms of hole failure during sand production.A significant strength anisotropy of reservoir rocks was identified,suggesting that drawdown in horizontal wells could lead to asymmetric bottomhole zone fracture,initiated at the upper and lower points on the wellbore contour.The obtained results allowed to determine(i)the drawdowns required to maintain wellbore stability in the given reservoir interval;(ii)the optimal parameters of downhole gravel filter screens for sand control;(iii)to identify the prevailing type of wellbore fracture and to localize failure initiation points on the wellbore walls.The results highlight the importance of integrating modern laboratory core analysis methods to enhance the development of complex reservoirs and reduce the risks of fractures and sand production in weakly cemented formations.展开更多
Distribution transformers play a vital role in power distribution systems,and their reliable operation is crucial for grid stability.This study presents a simulation-based framework for active fault diagnosis and earl...Distribution transformers play a vital role in power distribution systems,and their reliable operation is crucial for grid stability.This study presents a simulation-based framework for active fault diagnosis and early warning of distribution transformers,integrating Sample Ensemble Learning(SEL)with a Self-Optimizing Support Vector Machine(SO-SVM).The SEL technique enhances data diversity and mitigates class imbalance,while SO-SVM adaptively tunes its hyperparameters to improve classification accuracy.A comprehensive transformer model was developed in MATLAB/Simulink to simulate diverse fault scenarios,including inter-turn winding faults,core saturation,and thermal aging.Feature vectors were extracted from voltage,current,and temperature measurements to train and validate the proposed hybrid model.Quantitative analysis shows that the SEL–SO-SVM framework achieves a classification accuracy of 97.8%,a precision of 96.5%,and an F1-score of 97.2%.Beyond classification,the model effectively identified incipient faults,providing an early warning lead time of up to 2.5 s before significant deviations in operational parameters.This predictive capability underscores its potential for preventing catastrophic transformer failures and enabling timely maintenance actions.The proposed approach demonstrates strong applicability for enhancing the reliability and operational safety of distribution transformers in simulated environments,offering a promising foundation for future real-time and field-level implementations.展开更多
目的探究乳腺癌保乳术后美学效果客观评价工具BCCT.core(breast cancer conservative treatment.cosmetic results,BCCT.core)与日本乳腺癌学会(Japanese breast cancer society,JBCS)主观评价量表评分之间的一致性,为BCCT.core在临床...目的探究乳腺癌保乳术后美学效果客观评价工具BCCT.core(breast cancer conservative treatment.cosmetic results,BCCT.core)与日本乳腺癌学会(Japanese breast cancer society,JBCS)主观评价量表评分之间的一致性,为BCCT.core在临床应用提供可靠的循证依据。方法自2021年1月至2024年12月,甘肃中医药大学第三附属医院纳入107例接受乳腺癌保乳术的患者,其中传统保乳手术46例(43%)、整形保乳手术34例(32%)、腔镜保乳手术27例(25%)。通过BCCT.core软件对患者术后胸部正面照片进行自动化美学分析,同时3名乳腺外科医师使用JBCS量表进行评分。采用组内相关系数(ICC)评估医师间评分的一致性;Spearman等级相关系数对BCCT.core软件评分与医师评分进行相关性分析。结果医师间评分呈现中等一致性(ICC相关系数为0.63);BCCT.core软件评分与3名医师评分均值表现出高度相关性(Spearman's rho=0.87,P<0.001)。与医师使用JBCS量表评价相比,BCCT.core软件操作简便,高效,评价标准化以及结果可重复等优势。因此,在临床应用中,BCCT.core软件能够节省时间及人力物力成本。结论BCCT.core软件的评价结果与医师主观评分具有高度相关性和可比性,其客观性及可靠性使其可作为乳腺癌保乳术后美学效果评价的辅助工具。展开更多
文摘We read with great interest Deng et al.’s study 1 comparing sextant(6-core)and 12-core systematic biopsy in theMRI-targeted era,which valuably challenges the“more cores=higher accuracy”dogma by proposing a precision sampling strategy based on prostate cancer’s spatial distribution,aligning with personalized diagnosis trends.
基金financially supported by the National Natural Science Foundation of China(grant no.42120104005)Guizhou Provincial 2021 Science and Technology Subsidies(grant no.GZ2021SIG)+1 种基金Guizhou Provincial Science and Technology Projects(grant nos.ZK[2024]087GCC[2023]060)。
文摘The Martian core mainly contains iron,nickel and some light elements.However,controversies remain about the structure and chemical composition of the Martian core due to a lack of samples and marsquake data.Recently,the InSight lander collected long-term marsquake data,which improved the Martian interior structure model.B ased on the preliminary analysis of marsquake data,Mars has a molten liquid core with a radius of around 1700 km.As the Martian core has a smaller density and lower temperature than pure iron at corresponding pressure and temperature conditions,some light elements are introduced to reduce the density and liquidus temperature.With various methods for seismic analysis,in-situ high-pressure and high-temperature experiments,and first-principal calculations,the Martian core composition and evolution models have been updated in the past few years.Here,we review those studies on the light elements in the Martian core from four aspects including(1)high-temperature and high-pressure experiments,(2)marsquake data,(3)mineral physics model with molecular dynamics simulations and(4)cosmochemistry investigation.We discussed the effect of different light elements on the Martian core s density,sound velocity and liquidus temperature.Moreover,the review examines the varieties,abundances and forms of light elements in the Martian core.
文摘Within contemporary healthcare systems, professional identity among specialized nurses serves as a pivotal intrinsic factor influencing the development of their core competencies. This review synthesizes existing research, revealing that professional identity positively impacts the development of core competencies through multiple pathways, including psychological drive, behavioral facilitation, teamwork, and career stability. Building on this analysis, this paper proposes systematic enhancement strategies from four dimensions: education and training, organizational environment, cultural development, and individual growth, aiming to provide a reference for nursing practice and professional development.
基金supported by the fund of State Key Laboratory of Clean and Efficient Turbomachinery Power Equipment(No.DEC8300CG202210353EE280297)the China Postdoctoral Science Foundation(No.2021M692555)+1 种基金the Shaanxi Province Qinchuangyuan‘Scientists+Engineers’Team Building Project(No.2023KXJ-266)the Fundamental Research Funds for the Central Universities(No.xzy012023145)。
文摘Low reactivity and appropriate wettability between molten superalloys and ceramic materials are crucial for the production of high-quality superalloy castings.The sessile-drop experiment was employed to systematically investigate the interfacial reaction and wettability between the 4777DS1 superalloy and SiO_(2)-based ceramic core at various temperatures(1,480℃,1,500℃,1,520℃,and 1,550℃).The wetting behavior and interfacial reaction products at different temperatures were analyzed by scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),and X-ray diffraction(XRD).The interfacial reaction process and products were discussed,and the thermodynamic behavior and interfacial reaction mechanisms were elucidated.The results demonstrate that the wetting behavior and interfacial reaction between the 4777DS1 alloy and the ceramic core are significantly influenced by temperature.The wettability angle exhibits a trend of initial decrease followed by an increase with rising temperature,reaching a maximum of 139°at 1,480℃,indicating poorer wettability of the 4777DS1 superalloy with the ceramic core and better casting properties at this specific temperature.The most intense interfacial reaction occurs at 1,520℃,resulting in the formation of the main interfacial reaction products such as Al_(2)O_(3),SiO_(2),and HfO_(2).Additionally,some crystal-like products rich in Si and Hf distribute on the reaction layer.
基金supported by the Major Science and Technology Project of Gansu Province(Grant No.24ZD13FA003 and 23ZDWA005)National Natural Science Foundation of China(Grant No.42371140,42301163,41971087 and 42272332)the program of the State Key Laboratory of Cryospheric Science and Frozen Soil Engineering,CAS(No.CSFSEZZ-2411)。
文摘In permafrost regions of the QinghaiXizang Plateau,embankments of the Qinghai-Xizang Highway and Qinghai-Xizang Railway experiencing roadside water accumulation exhibit more pronounced engineering deteriorations.A widely accepted view is that the accumulated water adjacent to the embankment possesses substantial thermal energy,which accelerates the degradation-even disappearance-of the underlying permafrost.Moreover,the presence of roadside water keeps the embankment soil in a persistently high-moisture state,thereby making the frozen-soil embankment more susceptible to deformation under traffic loading.However,in the permafrost regions of the QinghaiXizang Plateau,deteriorations of embankments affected by roadside water are more commonly manifested as undulating pavement surfaces,and extensive crack networks appear on the embankment crest even where thermosyphons are installed.These manifestations are not fully consistent with the deterioration mechanisms proposed by existing viewpoints.We propose the hypothesis that temperature gradients,formed due to the freezing and thawing processes between the roadside wateraffected soil and the roadbed soil,lead to moisture migration under the influence of temperature gradients,resulting in frost heave and thaw settlement in the roadbed soil.To validate this hypothesis,we conducted the following investigations sequentially.Initially,we selected a roadbed with a thermosyphon(TPCT)system,which has a significant cooling effect,as the study object.By analyzing the temperature monitoring data of the roadbed section,the temperature variance was calculated to identify the time nodes where the temperature gradient of the roadbed soil was maximum and minimum.Subsequently,corresponding roadbed temperature distribution maps were drawn,illustrating the changes in the temperature and position of the lowtemperature core near the TPCT over time.Furthermore,using small-scale indoor model experiments,we qualitatively concluded that moisture in the soil migrates toward the TPCT due to the temperature gradient.Thereafter,combining borehole water content data and precipitation data from the sloped terrain construction site,the formation mechanisms and timing characteristics of roadside water accumulation were analyzed.Ultimately,by integrating the ground temperature data,air temperature data,roadside water formation mechanisms,and the operating characteristics of the TPCT,it was concluded that roadside water,while in a thawed state during TPCT operation,acts as a supplementary source for moisture migration in the roadbed soil.This migration leads to cracking in the TPCT roadbed.Therefore,this study reveals a novel damage mechanism:asynchronous freeze-thaw processes induce temperature gradients,which drive the migration of roadside water into the roadbed and are responsible for the cracking damage.
文摘[Objectives]To investigate the clinical efficacy of core stability training combined with conventional rehabilitation in the functional recovery of patients suffering from chronic low back pain.[Methods]A randomized controlled trial design was employed in this study.Ninety patients with chronic low back pain were recruited and randomly assigned to either a control group(n=45),which received conventional rehabilitation,or an experimental group(n=45),which received conventional rehabilitation combined with core stability training.Both groups underwent treatment for 6 weeks.Assessments were conducted using the visual analogue scale(VAS),Oswestry disability index(ODI),and finger-to-floor test prior to treatment,6 weeks following treatment,and during the follow-up period,respectively.[Results]Prior to treatment,no statistically significant differences were observed between the two patient groups in terms of general information and various baseline measurements(P>0.05).Following 6 weeks of treatment and throughout the follow-up period,both groups demonstrated significant improvements in VAS scores,ODI scores,and lumbar anteflexion range of motion compared to baseline measurements(P<0.05).Notably,the magnitude of improvement in the experimental group exceeded that of the control group,with this inter-group difference reaching statistical significance(P<0.05).No serious adverse reactions were reported during the treatment process.[Conclusions]Core stability training combined with conventional rehabilitation can significantly enhance the alleviation of pain and functional impairments in patients suffering from chronic low back pain.This approach holds valuable implications for the optimization of rehabilitation treatment protocols.
基金supported by the Natural Science Foundation of Anhui Province(2408085MC058 and 2308085QC91)National Natural Science Foundation of China(32301783and U21A20214)+5 种基金Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS CSIAF-202303)Nanfan special project,CAAS(YYLH2309,YBXM2322,YYLH2401)Scientific Innovation 2030 Project(2022ZD0401703)CAAS Innovative Team Award,Science and Technology of Innovative research program of Anhui Province(202423m1005002)National Key Research and Development Program of China(2023YFD1200900)the Natural Science Foundation General Program of Hebei Province(C2024204242).
文摘IR64 is an elite Xian/indica variety developed by International Rice Research Institute(IRRl)in 1985,which has been the most widely grown variety and core breeding parent in South/Southeast Asia(Mackill and Khush,2018).IR64 has been utilized to develop stress-tolerant(such as drought-adapted and submergenceresistant)near-isogenic lines,underscoring its great potential in agricultural genomics(Tanaka et al.,2020).
基金National Natural Science Foundation of China,No.42225105,No.42201175The China Postdoctoral Science Foundation,No.2023M733605。
文摘As an essential component of terrestrial carbon sinks,lake sediments store vast quantities of both organic carbon(OC)and inorganic carbon(IC).However,the spatiotemporal relationship between the OC and IC in sediments and their responses to climate change remains unclear,which hinders the comprehensive understanding of carbon dynamics in lake ecosystems.This study systematically analyzes the spatiotemporal dynamics of carbon burial across the Tibetan Plateau using surface sediments from 119 lakes and sediment cores from four representative lakes.Results show that OC burial dominates in humid and dry sub-humid zones,whereas IC burial prevails in arid and semi-arid regions.This distribution reflects the influences of lake and catchment productivity and water chemistry on OC and IC patterns.Sediment cores confirm that these factors have consistently affected lake carbon burial over the past century.Specifically,in humid and dry sub-humid zones,increased precipitation enhances watershed productivity and sedimentation,promoting coupled OC and IC burial.In arid and semi-arid regions,wind-driven dust supplies nutrients and alters water chemistry,also driving coupled OC and IC burial.Based on these findings,the carbon sink capacity of lake sediments on the Tibetan Plateau is projected to increase under the“warming and wetting”trend.
文摘General Information Journal of Chinese Pharmaceutical Sciences(JCPS)is a peer-reviewed bimonthly journal founded in 1992.JCPS has been indexed in the Core Journals of China's science and technology field.At present it has been included by Chemical Abstracts(CA),UIPD,Index of Copurnicus(IC),CABI,SCOPUS,JSTChina,DOAJ,EBSCO,CSTPCD,Chinese Science Citation Database(CSCD),the Chinese National Knowledge Infrastructure(CNKI)and World Journal Clout Index(WJCI)Report.
文摘The purpose of this study is to gain perspectives on introducing IBCTL(International Baccalaureate Certificate in Teaching and Learning)into graduate school of teacher education in Japan,which are currently providing advanced teacher training programs aimed at cultivating student agency,a comprehensive set of skills necessary for children living in the future,as advocated by the Organisation for Economic Co-operation and Development(OECD)Education 2030 Project.To achieve this goal,I examined the curriculum and structure that are important for IB teacher training and the introduction of IBCTL.I attempted to achieve this goal by examining the curriculum being developed at a graduate school of teacher education attempting to implement IBCTL and the creation of a syllabus based on that curriculum through lesson planning.As a result,I examined the curriculum and structure as a perspective for introducing IBCTL into graduate school of teacher education in Japan,where advanced teacher training is required.I found that a core curriculum and structure that incorporates the core of the IBCTL into the core of graduate school of teacher education programs is important for implementing an IB education that is aligned with the advancement of teacher training and the development of student agency.
基金Open Access funding enabled and organized by Projekt DEAL.
文摘In this study,copper extraction from low-grade oxide-sulfide ores was investigated using a leaching method combined with response surface methodology(RSM)to optimize operational conditions and assess leaching kinetics.Given copper's extensive industrial applications,sustainable recovery from low-grade ores is critical.Five key parameters-acid concentration,leaching time,particle size,temperature,and solids percentage-were identified as major influences on copper recovery.The results revealed that leaching time and solids percentage,along with interactions between temperature-time and temperature-solids percentage,had the most significant effects.Optimal conditions for 80% copper recovery while minimizing iron recovery below 3% included an acid concentration of 1.21 mol L^(-1),a leaching time of 108 min,a particle size of 438μm,a temperature of 45℃,and a solids percentage of 18.2%.Leaching kinetics were analyzed using shrinking core models,with the Dickinson model best describing the process,showing an activation energy of 32.63 kJ mol^(-1),indicative of mixed diffusion and chemical reaction control.The final kinetic model effectively predicted the influence of key parameters.These findings highlight the importance of optimizing process variables and selecting suitable kinetic models to enhance extraction efficiency,reduce costs,and improve sustainability in copper recovery.
基金financially supported by the National Natural Science Foundation of China(Nos.22372143 and 22208281)the Hebei Natural Science Foundation(Nos.B2023203001 and B2025203050)the Science Research Project of Hebei Education Department(BJK2024122)。
文摘Rational design of non-noble electrocatalysts with high performance for oxygen evolution reaction(OER)still remains a challenge.In this study,a ZIF-derived electrocatalyst(Co@Fe-P)with a core-shell structure is designed by using Co-compounds as the core and PO_(4)^(3-)decorated Fe-compounds as the shell.The inner Co-core and outer Fe-shell are connected through Co-O-Fe and Fe-O-P linkage.The Co@Fe-P electrocatalyst exhibits an enhanced performance for OER with a low overpotential(280 mV),low Tafel slope(41.9 mV dec^(-1))at 10 mA cm^(-2),and a 60-h durability.The electron transfer from the CoOOH-core to the FeOOH-shell is greatly facilitated,which improves the OER activity of Co@Fe-P kinetically.Theoretical calculations indicate that the interaction of Co-O-Fe and Fe-O-P in Co@Fe-P reduces the overlap between the O 2p and Fe 3d orbitals,which greatly facilitates the transformation from*OH to*O during the OER process via the adsorbate evolution mechanism(AEM)pathway.This finding provides insight for the design of efficient electrocatalysts for OER.
基金the National Natural Science Foundation of China(Grant Nos.42274003,41974007,and 41774019).
文摘The GRACE(Gravity Recovery and Climate Experiment)space mission recorded temporal variation characteristics of the global gravity field at decadal timescales.The gravity data have been shown to capture the dynamics of flows within the outer core and their effects on the core-mantle boundary.We first aim to remove global surface process gravity signals from the GRACE data.We then construct the global core magnetic field according to the CHAOS-7 model.Finally,we apply the blind source separation method to decompose the processed gravity signals and core magnetic signals and compute the power spectral density of the gravity and magnetic field signals by using the Lomb-Scargle periodogram approach.We have discovered a signal cycle(of~6 years)in the principal components of the core magnetic and gravity signals,potentially as a result of deep Earth processes.The main principal components of the core magnetic and gravity signals reveal that the variation trends in the second-order time derivative of the core magnetic field are similar to those in the gravity field.After 2014,the second-order time derivative of the core magnetic field exhibited linear and rapid change characteristics,which were the same as the change in the gravity field and are consistent with existing research results.
基金National Natural Science Foundation of China,No.42201221,No.42471246Liaoning Province Natural Science Foundation Project,No.2023-MS-254+1 种基金Liaoning Province Social Science Planning Fund Project,No.L22CJY016Dalian Federation of Social Sciences,No.2022dlskzd037。
文摘The development of human settlements(HS)in coastal cities is an integral component and a vital pathway toward building a strong marine power.It is also an essential requirement for achieving the coordinated development of HS systems in these cities.In this study,we constructed an indicator system to analyze the coupling coordination degree(CCD)of HS systems in coastal cities in the Bohai Rim region of China(CCBRR).This study is based on five systems and employs methods such as the entropy weight method,CCD model,spatial trend surface analysis,and geographic detector to examine comprehensively the spatial and temporal patterns of CCD in 17 CCBRR during the period 2011–2022,as well as to explore their influencing factors.The findings are as follows:(1)Temporally,the CCD is high and exhibits a slow increasing trend,with distinct stage characteristics.(2)Spatially,the distribution of CCD reveals a“one core,many strengths”structural pattern.(3)Moreover,socioeconomic factors are the dominant force driving the CCD of the internal HS systems in the CCBRR.(4)Finally,we constructed a coupling coordination driving mechanism for HS in the CCBRR with the aim of providing scientific references and path choices for the high-quality and coordinated development of the CCBRR along with the implementation of the new quality productive forces regionalization.
基金financially supported by the Na-tional Natural Science Foundation of China (No.52474355)the Fundamental Research Funds for the Central Uni-versities,China (No.N25DCG006).
文摘Liquid core reduction(LCR)technology,originally developed for continuous thin-slab casting,allows space for a submerged entry nozzle in a mold while improving production efficiency.Recent experimental attempts explore the implementation of LCR in regular slab casting processes.However,regular slabs(2–3 times thicker than thin slabs)face critical challenges in terms of excessive deformation and stress concentration under external forces,which induce intermediate cracks and thus hinder successful LCR adoption in regular slab production.This study evaluates the feasibility of LCR for producing regular slabs and identifies optimal reduction parameters to prevent crack initiation.A three-dimensional thermal–mechanical coupled model is proposed using the finite element method(FEM),integrated with the equivalent replacement liquid steel(ERLS)method and the normalized Cockcroft–Latham damage model,to achieve quantitative prediction of intermediate crack risk during the LCR process.The ERLS model simulates the extrusion flow and expulsion behavior of the liquid core,and its accuracy is validated against actual production measurements.To identify the critical damage value leading to intermediate crack initiation,this study conducts a consistency analysis between high-temperature tensile tests and FEM-based simulations using damage models.Based on this value,crack prediction is performed for Q355 slabs with cross-sectional dimensions of 170 mm×1450 mm.Using the prediction results,an optimal reduction scheme is determined,wherein the second segment accounts for 50%of the total reduction,the third segment for 32.5%,and the fourth segment for 17.5%,with the theoretical value of maximum reduction being 34 mm.These results provide actionable guidelines for the potential implementation of LCR in regular slab-casting systems.
基金supported by the Russian Science Foundation(Grant No.23-77-01037,https://rscf.ru/en/project/23-77-01037/).
文摘The paper presents the results of geomechanical and CT-based studies of deformation,fracture and filtration processes in reservoir rocks of the Arctic shelf gas condensate field.The experimental study combines(i)determination of mechanical properties,(ii)true triaxial physical modeling of near-wellbore filtration and geomechanical processes,(iii)triaxial sand production studies,and(iv)digital CT-analysis of the rock matrix and sand particles.Based on true triaxial physical modeling,the relationships between permeability,rock deformation,and stresses around a horizontal well during drawdown were determined.Hollow cylinder-type tests were used to determine the stress conditions for sand release initiation,the intensity of sand production under varying stress states,and the total volume of sand produced.Digital particle size analysis of the matrix and released sand provided insights into the dominant mechanisms of hole failure during sand production.A significant strength anisotropy of reservoir rocks was identified,suggesting that drawdown in horizontal wells could lead to asymmetric bottomhole zone fracture,initiated at the upper and lower points on the wellbore contour.The obtained results allowed to determine(i)the drawdowns required to maintain wellbore stability in the given reservoir interval;(ii)the optimal parameters of downhole gravel filter screens for sand control;(iii)to identify the prevailing type of wellbore fracture and to localize failure initiation points on the wellbore walls.The results highlight the importance of integrating modern laboratory core analysis methods to enhance the development of complex reservoirs and reduce the risks of fractures and sand production in weakly cemented formations.
文摘Distribution transformers play a vital role in power distribution systems,and their reliable operation is crucial for grid stability.This study presents a simulation-based framework for active fault diagnosis and early warning of distribution transformers,integrating Sample Ensemble Learning(SEL)with a Self-Optimizing Support Vector Machine(SO-SVM).The SEL technique enhances data diversity and mitigates class imbalance,while SO-SVM adaptively tunes its hyperparameters to improve classification accuracy.A comprehensive transformer model was developed in MATLAB/Simulink to simulate diverse fault scenarios,including inter-turn winding faults,core saturation,and thermal aging.Feature vectors were extracted from voltage,current,and temperature measurements to train and validate the proposed hybrid model.Quantitative analysis shows that the SEL–SO-SVM framework achieves a classification accuracy of 97.8%,a precision of 96.5%,and an F1-score of 97.2%.Beyond classification,the model effectively identified incipient faults,providing an early warning lead time of up to 2.5 s before significant deviations in operational parameters.This predictive capability underscores its potential for preventing catastrophic transformer failures and enabling timely maintenance actions.The proposed approach demonstrates strong applicability for enhancing the reliability and operational safety of distribution transformers in simulated environments,offering a promising foundation for future real-time and field-level implementations.
文摘目的探究乳腺癌保乳术后美学效果客观评价工具BCCT.core(breast cancer conservative treatment.cosmetic results,BCCT.core)与日本乳腺癌学会(Japanese breast cancer society,JBCS)主观评价量表评分之间的一致性,为BCCT.core在临床应用提供可靠的循证依据。方法自2021年1月至2024年12月,甘肃中医药大学第三附属医院纳入107例接受乳腺癌保乳术的患者,其中传统保乳手术46例(43%)、整形保乳手术34例(32%)、腔镜保乳手术27例(25%)。通过BCCT.core软件对患者术后胸部正面照片进行自动化美学分析,同时3名乳腺外科医师使用JBCS量表进行评分。采用组内相关系数(ICC)评估医师间评分的一致性;Spearman等级相关系数对BCCT.core软件评分与医师评分进行相关性分析。结果医师间评分呈现中等一致性(ICC相关系数为0.63);BCCT.core软件评分与3名医师评分均值表现出高度相关性(Spearman's rho=0.87,P<0.001)。与医师使用JBCS量表评价相比,BCCT.core软件操作简便,高效,评价标准化以及结果可重复等优势。因此,在临床应用中,BCCT.core软件能够节省时间及人力物力成本。结论BCCT.core软件的评价结果与医师主观评分具有高度相关性和可比性,其客观性及可靠性使其可作为乳腺癌保乳术后美学效果评价的辅助工具。
