Conversion-type electrode materials hold significant promise for potassium-ion batteries(PIBs)due to their high theoretical capacities,yet their practical deployment is hindered by sluggish kinetics and irreversible s...Conversion-type electrode materials hold significant promise for potassium-ion batteries(PIBs)due to their high theoretical capacities,yet their practical deployment is hindered by sluggish kinetics and irreversible structural degradation.To overcome these limitations,we propose a rationally engineered nanoreactor architecture that stabilizes defect-rich MoS_(2)via interlayer incorporation of a carbon monolayer,followed by encapsulation within a nitrogen-doped carbon shell,forming a MoSSe@NC heterostructure.This tailored structure synergistically accelerates both K^(+)diffusion kinetics and electron transfer,enabling unprecedented rate performance(107 mAh g^(-1)at 10 Ag^(-1))and ultralong cyclability(86.5%capacity retention after 1200 cycles at 3 A g^(-1)).Mechanistic insights reveal a distinctive“adsorption-conversion”pathway,where sulfur vacancies on exposed S-Mo-S basal planes act as preferential K^(+)adsorption sites,effectively suppressing parasitic phase transitions during intercalation.In situ X-ray diffraction and transmission electron microscopy corroborate the structural reversibility of the conversion reaction,with the carbon matrix dynamically accommodating strain while preserving electrode integrity.This work not only advances the understanding of defect-driven interfacial chemistry in conversion-type materials but also provides a versatile strategy for designing high-performance anodes in next-generation PIBs through heterostructure engineering.展开更多
Background:Disaster mental health outcomes of individuals may be affected by the families they inhabit,with effects rippling through the entire family system.Existing research on the experience of children in disaster...Background:Disaster mental health outcomes of individuals may be affected by the families they inhabit,with effects rippling through the entire family system.Existing research on the experience of children in disasters has typically been limited to examining single individuals or,at most,family dyads.Research is needed to explore interactions within families as a whole,including interactions among multiple family members,as well as with community entities in a broad systems approach with dynamic analysis of family systems over time.The purpose of this study was to combine quantitative and qualitative data using structured diagnostic interviews and accompanying open-ended narratives of family members(spouses and children)of survivors of the 9/11 attacks.Methods:This study examined 60 members in 25 families of employees affected by the 9/11 attacks on New York City’s World Trade Center,using a mixed methods approach,collecting quantitative data using full assessments of psychiatric disorders and qualitative data from detailed personal disaster narratives.The employees were a highly 9/11 trauma-exposed group,with about one-fourth developing posttraumatic stress disorder(PTSD).The employees’exposures and PTSD did not regularly appear to propagate straightforwardly to psychopathology in their spouses or children.Based on the impact of disaster experience,4 illustrative families were selected for narrative and family systems analyses.Results:Qualitative analysis of their narratives suggested distinct family system patterns or archetypes that may reflect different ways that families cope with disaster.Conclusion:Findings suggest that family systems and family dynamics may influence not only disaster trauma-exposed members but also other family members in supporting one another and coping with the disaster,with interactions with outside community influences adding further complexity.This information may help guide disaster response efforts to provide psychosocial support targeted to specific family patterns.展开更多
Objectives:At the time of the bombing of the federal building in Oklahoma City,Oklahoma(OKC),it was the deadliest terrorist attack in the United States of America.Available research on this incident,and in general,has...Objectives:At the time of the bombing of the federal building in Oklahoma City,Oklahoma(OKC),it was the deadliest terrorist attack in the United States of America.Available research on this incident,and in general,has been quantitative,using deductive methods.The purpose of the current study was to systematically examine professional disaster response workers’emotions elicited spontaneously and in detail as they were experienced over time after a major disaster.This qualitative study will add to existing knowledge of psychopathology and the psychosocial effects of disasters on professional responders,which have not been explored by prior quantitative studies.Methods:A volunteer sample of 181 rescue and recovery workers for the 1995 bombing of the OKC Murrah Federal Building was interviewed approximately 3 years after the bombing.These responders were asked open-ended questions to elicit undirected responses in their own words.In these interviews,they were prompted to describe their feelings at 3 distinct time points:upon their arrival at the bombing scene(“immediately”),in the first 1 week following the bombing,and currently at the time of the interview(“now”).Results:Data items were coded into the 5 themes:Anticipation,Shock and awe,Negative reactions,Positive reactions,and Emotionally unengaged/unaffected.The emotional themes of the responders mapped into 2 conceptual domains.The first domain is related to common human responses to horrible events such as the bombing.The second domain is related to the professional identities of the disaster responders.Conclusions:Specific aspects of the professional responder roles asserted themselves,shaping their emotional responses distinctly from those of the bomb blast survivors.This study identified both negative and positive emotions,which may help identify risk for or resistance to posttraumatic stress disorder(PTSD).展开更多
Background:While quantitative research has determined that emotional distress and psychiatric illness among frontline healthcare workers increased with the COVID-19 pandemic,detailed qualitative data describing their ...Background:While quantitative research has determined that emotional distress and psychiatric illness among frontline healthcare workers increased with the COVID-19 pandemic,detailed qualitative data describing their personal experiences are needed in order to make appropriate plans to address provider mental health in future pandemics.This study aims to further explore the psychological effects of the pandemic on COVID-19 ICU clinicians and administrators through focus groups.Methods:Two separate 2-h focus groups of physicians were conducted,one with frontline faculty clinicians and another with administrators.Qualitative data analysis was conducted.Results:In September and November 2023,volunteer samples were recruited from the pulmonary and critical care medicine division of The University of Texas Southwestern physicians who served during the pandemic primarily as clinicians(N=6)or in major administrative roles(N=5).Perceptions of both administrators’and clinicians’pandemic experiences were coded into the same 7 qualitative themes:planning,sense of community and isolation,disparities and inequalities,communication and listening,leadership,effects of the pandemic,and emotional/psychiatric/coping responses.Effects of the pandemic were the most coded theme in both groups;second was disparities and inequalities for clinicians and pandemic planning for administrators.Thematic content is summarized separately for clinicians and administrators,illustrated with representative quotes.Conclusion:This study adds detailed qualitative findings to enrich existing quantitative knowledge on frontline COVID-19 workers’emotional responses.Both clinicians and administrators identified helpful and non-helpful institutional responses.These findings are consistent with prior studies of disaster worker experiences and may help to inform efforts to address provider mental health in future pandemics.展开更多
Open pit mining operations generate significant spoil dumps that need to be characterised for stability to identify potentially unstable slopes.However,the current subjective practice for spoil characterisation often ...Open pit mining operations generate significant spoil dumps that need to be characterised for stability to identify potentially unstable slopes.However,the current subjective practice for spoil characterisation often involves tedious and risky field work.To this end,this study demonstrated the use of periodically acquired unmanned aerial vehicle(UAV)-based images over a coal mine spoil dump in New South Wales,Australia.A granular approach that captures the variability of each truck offload pile on a dump was adopted through morphology-based segmentation and ensemble algorithm-based classification which consolidates predictions from multiple classifiers.Overall accuracy of over 90% in the material characterisation based on the classification framework was achieved.The two-dimensional classification outcome was then transformed into three-dimensional(3D)block models using a point-based interpolation approach for stability analysis.The factor of safety derived from the granular approach offered improved assessment of failure risk compared to the conventional approaches,which treat the entire dump as a uniform category.This rapid classification and assessment method proposed in this study will help reduce the uncertainty associated with the variability of spoil dumps in slope stability assessments,thereby enhancing the safety and efficiency of mining operations.展开更多
Minor errors in the spoil deposition process,such as placing stronger materials with higher shear strength over weaker ones,can lead to potential dump failure.Irregular deposition and inadequate compaction complicate ...Minor errors in the spoil deposition process,such as placing stronger materials with higher shear strength over weaker ones,can lead to potential dump failure.Irregular deposition and inadequate compaction complicate coal spoil behaviour,neces-sitating a robust methodology for temporal monitoring.This study explores using unmanned aerial vehicles(UAV)equipped with red-green-blue(RGB)sensors for efficient data acquisition.Despite their prevalence,raw UAV data exhibit temporal inconsistency,hindering accurate assessments of changes over time which could be attributed to radiometric errors.To this end,the study introduces an empirical line calibration with invariant targets(ELC-IT),for precise calibration across diverse scenes,particularly in the context of UAV imagery used to monitor the evolving nature of spoil dumps.To evaluate the effec-tiveness of this calibration approach,accuracy assessment of an object-based classification is conducted on both calibrated and uncalibrated data.This classification involves several steps:performing segmentation,carrying out feature extraction,and integrating the extracted features and ground truth labels collected over the time period of UAV image capture into machine learning pipelines.Calibrated RGB data exhibit a substantial performance advantage,achieving a 90.7%overall accuracy for spoil pile classification using ensemble(subspace discriminant),representing a noteworthy 7%improvement compared to classifying uncalibrated data.The study highlights the critical role of data calibration in optimising UAV effectiveness for spatio-temporal mine dump monitoring.These findings play a crucial role in informing and refining sustainable management practices within the domain of mine waste management.展开更多
This study investigated the validity and sensitivity of a custom-made shoelace tensile testing system.The aim was to analyze the distribution pattern of shoelace tension in different positions and under different tigh...This study investigated the validity and sensitivity of a custom-made shoelace tensile testing system.The aim was to analyze the distribution pattern of shoelace tension in different positions and under different tightness levels during running.Mechanical tests were conducted using 16 weights,and various statistical analyses,including linear regression,Bland-Altman plots,coefficient of variation,and intraclass correlation coefficient,were performed to assess the system’s validity.Fifteen male amateur runners participated in the study,and three conditions(loose,comfortable,and tight)were measured during an upright stance.The system utilized VICON motion systems,a Kistler force plate,and a Photoelectric gate speed measurement system.Results showed a linear relationship between voltage and load at the three sensors(R2≥0.9997).Bland-Altman plots demonstrated 95%prediction intervals within±1.96SD from zero for all sensors.The average coefficient of variation for each sensor was less than 0.38%.Intraclass correlation coefficient values were larger than 0.999(p<0.0001)for each sensor.The peak tension of the front shoelace was greater than that of the front and middle when the shoelace was loose and tight.The rear shoelace had the highest tension force.The study also found that shoelace tension varied throughout the gait cycle during running.Overall,this research provides a novel and validated method for measuring shoelace tensile stress,which has implications for developing automatic shoelace fastening systems.展开更多
We use the Fe Kα emission in X-rays from non-equilibrium ionizing plasmas as a probe to explore the dust in supernova remnants(SNRs). We applied our model to Cassiopeia A(Cas A), a well-studied SNR with plenty of obs...We use the Fe Kα emission in X-rays from non-equilibrium ionizing plasmas as a probe to explore the dust in supernova remnants(SNRs). We applied our model to Cassiopeia A(Cas A), a well-studied SNR with plenty of observational data as a test. We use Chandra Advanced CCD Imaging Spectrometer 980 ks data of Cas A, and AtomDB v3.0.9, an atomic database for X-ray plasma spectral modeling, to fit 248 spectra. A two-temperature model is adopted to describe the physical conditions of shocked ejecta and iron-rich plasma. We measure the Fe Kα flux ratio and the centroid difference of the dust and gas contributions. We find strong 6.4 keV line emission components, which indicates that iron-rich dust can survive within Cas A's shocked ejecta. We also find that the Fe Kα complex demonstrates an apparent double-hump structure in some Fe–K rich regions, which may be caused by both dust and multi-ejecta structure in Cas A. The results of Fe Kα structures are consistent with our model for a dust cloud embedded in multi-phase ejecta and suggest the presence of both dust sputtering and drag effects in those regions. It is currently still limited by the low spatial and spectrum resolution for the current X-ray detectors, but should be more useful when the new generation, high-resolution X-ray telescopes come into service.展开更多
With increased computational power, reverse-time prestack depth migration（RT-PSDM） has become a preferred imaging tool in seismic exploration, yet its use has remained relatively limited in ground-penetrating radar...With increased computational power, reverse-time prestack depth migration（RT-PSDM） has become a preferred imaging tool in seismic exploration, yet its use has remained relatively limited in ground-penetrating radar（GPR） applications. Complex topography alters the wavefield kinematics making for a challenging imaging problem. Model simulations show that topographic variation can substantially distort reflection amplitudes due to irregular wavefield spreading, attenuation anomalies due to irregular path lengths, and focusing and defocusing effects at the surface. The effects are magnified when the topographic variations are on the same order as the depth of investigation––a situation that is often encountered in GPR investigations. Here, I use a full wave-equation RT-PSDM algorithm to image GPR data in the presence of large topographic variability relative to the depth of investigation. The source and receiver wavefields are propagated directly from the topographic surface and this approach inherently corrects for irregular kinematics, spreading and attenuation. The results show that when GPR data are acquired in areas of extreme topography, RT-PSDM can accurately reconstruct reflector geometry as well as reflection amplitude.展开更多
Twinning and detwinning behavior,together with slip behavior,are studied in a textured AZ31 magnesium alloy under compressive and tensile strains along the rolling direction(RD)after each interrupted mechanical test v...Twinning and detwinning behavior,together with slip behavior,are studied in a textured AZ31 magnesium alloy under compressive and tensile strains along the rolling direction(RD)after each interrupted mechanical test via quasi in-situ electron backscattered diffraction technique.The results show that twinning firstly takes place under the compressive strain along the RD.With the increasing compressive strain,{1012}tensile twins firstly nucleate,then propagate,and finally thicken.While under a reversed tensile strain along the RD,detwinning occurs.No nucleation happens during detwinning.Thus,tensile twins can detwin at lower tensile strain,followed by thinning,shortening,and vanishing.Slips are also activated to accommodate the plastic deformation.In the matrix,prismatic slip can only dominate at relatively high strains.Otherwise,basal slip dominates.While in the twins,prismatic slip can activate at lower strains,which is ascribed to the texture reorientation.展开更多
Background: Self-efficacy has been identified as an important determinant of youth's behavior change including physical activity(PA) participation. However, the dimensionality check of a PA self-efficacy scale has...Background: Self-efficacy has been identified as an important determinant of youth's behavior change including physical activity(PA) participation. However, the dimensionality check of a PA self-efficacy scale has rarely been conducted in China. The current study aims to examine(1) the unidimensionality of a shortened Chinese version of PA self-efficacy scale(S-PASESC);(2) the measurement invariance of S-PASESC across gender and levels of education;(3) the latent factor mean difference between gender and levels of education;(4) the direct effects of self-efficacy on PA by different gender and education levels; and(5) the comparisons of the direct effects of self-efficacy on PA across gender and education levels.Methods: The participants were 5 th through 11 th grade public school students recruited from 7 cities located in different geographic regions of China. The final data include a total of 3003 participants(49.7% boys) who have completed the scales.Results: Confirmatory factor analysis(CFA) test supported the unidimensionality of S-PASESC. The S-PASESC is invariant across gender and 3 levels of education at both configural, full metric, and full scalar levels. Findings from latent mean comparisons showed that boys reported higher PA self-efficacy than girls. Students' perceived PA self-efficacy tend to decrease from elementary to high school. Finally, self-efficacy positively related to PA by groups of different gender and education levels and the relationship between self-efficacy and PA is stronger among middle school boys than girls.Conclusion: Findings suggest S-PASESC is a valid scale for measuring Chinese students' PA self-efficacy.展开更多
Background： Active educational video games （AVGs） appear to have a positive effect on elementary school students＇ motivation leading to enhanced learning outcomes. The purpose of this study was to identify the eff...Background： Active educational video games （AVGs） appear to have a positive effect on elementary school students＇ motivation leading to enhanced learning outcomes. The purpose of this study was to identify the effectiveness of an AVG on elementary school students＇ science knowledge learning, physical activity （PA） level, and interest-based motivation. Methods： In this randomized controlled study, 53 elementary school students were assigned to an experimental condition or a comparison condition. The experimental condition provided an AVG learning environment, whereas the comparison condition was based on sedentary educational video games. Results： The results of repeated measures analysis of variance （ANOVA） on the knowledge test showed that students in both groups performed better on the post-test than they did on the pre-test （p 〈 0.001, η2 = 0.486）, and their post-test scores did not differ significantly. The experimental condition provided a more active environment since the students＇ average heart rates （HRs） were in the Target-Heart-Rate-Zone （HR = 134 bpm）, which was significantly higher than the average HR （103 bpm） from the comparison condition （t = 7.212, p 〈 0.001）. Students in the experimental condition perceived a higher level of situational interest than their counterparts in the comparison group （p 〈 0.01, and η2 = 0.301）. Conclusion： These results suggest that AVGs benefit children more in terms of PA and motivation than traditional video games by providing an enjoyable learning experience and sufficient PA.展开更多
Introduction:Since 2015 is the year of FinTech in Taiwan,it is worth investigating the challenges that emerged when banks were encouraged to invest in FinTech companies for collaboration.This study aims to identify th...Introduction:Since 2015 is the year of FinTech in Taiwan,it is worth investigating the challenges that emerged when banks were encouraged to invest in FinTech companies for collaboration.This study aims to identify the strategic considerations in the process of searching for FinTech investment targets.Case description:This study used a case study investigation of a top-5 bank in Taiwan.The major data sources include the meeting notes of the FinTech investment task force and interviews with the team members.Co-opetition theory was adopted as the theoretical framework and interview questions were derived from the PARTS strategies in co-petition theory.The results relate to:(1)the strategic goals of FinTech investment,(2)the added value from FinTech companies,(3)criteria in selecting candidates in the same FinTech area,(4)choosing to work as either a cooperator or a competitor,and(5)barriers from policies and regulations.Discussion and evaluation:This study has several findings:(1)regulations and policies shape FinTech’s development;(2)banks,technology companies,and customers are not“FinTech ready;”(3)Compare top-down with bottom up strategies;(4)banks and FinTech companies have complex relationships;(5)it is unlikely that Taiwan will produce FinTech disruptors in the near future.Conclusion:The findings and discussion can benefit researchers and administrators in finance-related industries.More studies are desired to observe long-term development in terms of how companies collaborate or compete in specific FinTech areas.展开更多
The structural integrity of mine dumps is crucial for mining operations to avoid adverse impacts on the triple bottom-line.Routine temporal assessments of coal mine dumps are a compliant requirement to ensure design r...The structural integrity of mine dumps is crucial for mining operations to avoid adverse impacts on the triple bottom-line.Routine temporal assessments of coal mine dumps are a compliant requirement to ensure design reconciliation as spoil off-loading continues over time.Generally,the conventional in-situ coal spoil characterisation is inefficient,laborious,hazardous,and prone to experts'observation biases.To this end,this study explores a novel approach to develop automated coal spoil characterisation using unmanned aerial vehicle(UAV)based optical remote sensing.The textural and spectral properties of the high-resolution UAV images were utilised to derive lithology and geotechnical parameters(i.e.,fabric structure and relative density/consistency)in the proposed workflow.The raw images were converted to an orthomosaic using structure from motion aided processing.Then,structural descriptors were computed per pixel to enhance feature modalities of the spoil materials.Finally,machine learning algorithms were employed with ground truth from experts as training and testing data to characterise spoil rapidly with minimal human intervention.The characterisation accuracies achieved from the proposed approach manifest a digital solution to address the limitations in the conventional characterisation approach.展开更多
Using marble samples from the Nikani Ghar marble and Nowshera Formation from Northern Pakistan the determination of the temperature of metamorphism was undertaken with the help of calcite-dolomite solvus geothermomete...Using marble samples from the Nikani Ghar marble and Nowshera Formation from Northern Pakistan the determination of the temperature of metamorphism was undertaken with the help of calcite-dolomite solvus geothermometer. Two types of marbles, that is, calcite-dolomite marble and quartz-bearing calcite-dolomite marble were selected. Petrographic and scanning electron microscope analysis of dolomite samples indicated different grain sizes. X-ray diffraction technique indicated the calcites MgCO3 content up to 7.93 mol.%. Nikani Ghar marble samples have shown lower contents of MgCO3 as compared to samples from Nowshera Formation. The calcite-dolomite-quartz marble has also showed relatively lower MgCO3 content and hence rather low temperature （-500 ℃）. The temperature reached during peak metamorphism of the investigated marble occurrence, based on calcitedolomite solvus was 628 ℃. Metamorphic temperatures derived from the present study were shown as a linear graph and values were in good agreement with the published literature.展开更多
Textured magnesium alloys usually exhibit anisotropic mechanical behavior due to the asymmetric activation of different twinning and slipping modes.This work focuses on the pyramidal slip responses of rolled AZ31 magn...Textured magnesium alloys usually exhibit anisotropic mechanical behavior due to the asymmetric activation of different twinning and slipping modes.This work focuses on the pyramidal slip responses of rolled AZ31 magnesium alloy under two loading conditions,compressive and tensile loading along the normal direction.Under the condition where the compressive loading direction is closely parallel to the c-axis of the unit cell,tensile twinning and basal slips are prohibited, dislocations then active and tend to accumulate at grain boundaries and form dislocation walls.Meanwhile,these dislocations exhibit zigzag morphologies,which result from the cross-slip from {10■1} first-order pyramidal plane to {11■2} second-order pyramidal plane,then back to {10■1} first-order pyramidal plane.Under the condition where tensile twins are prevalent,{10■1} first-order and {11■2} second-order pyramidal dislocations are favorable to be activated.Both types of dislocations behave climb-like dissociations onto the basal plane,forming zigzag dislocations.展开更多
基金financially supported by the supported by Shandong Provincial Natural Science Foundation(ZR2024MB108)Taishan Young Scholar Program(tsqn202312312)Excellent Young Scholars of the Shandong Provincial Natural Science Foundation(Overseas)(2023HWYQ-112)。
文摘Conversion-type electrode materials hold significant promise for potassium-ion batteries(PIBs)due to their high theoretical capacities,yet their practical deployment is hindered by sluggish kinetics and irreversible structural degradation.To overcome these limitations,we propose a rationally engineered nanoreactor architecture that stabilizes defect-rich MoS_(2)via interlayer incorporation of a carbon monolayer,followed by encapsulation within a nitrogen-doped carbon shell,forming a MoSSe@NC heterostructure.This tailored structure synergistically accelerates both K^(+)diffusion kinetics and electron transfer,enabling unprecedented rate performance(107 mAh g^(-1)at 10 Ag^(-1))and ultralong cyclability(86.5%capacity retention after 1200 cycles at 3 A g^(-1)).Mechanistic insights reveal a distinctive“adsorption-conversion”pathway,where sulfur vacancies on exposed S-Mo-S basal planes act as preferential K^(+)adsorption sites,effectively suppressing parasitic phase transitions during intercalation.In situ X-ray diffraction and transmission electron microscopy corroborate the structural reversibility of the conversion reaction,with the carbon matrix dynamically accommodating strain while preserving electrode integrity.This work not only advances the understanding of defect-driven interfacial chemistry in conversion-type materials but also provides a versatile strategy for designing high-performance anodes in next-generation PIBs through heterostructure engineering.
基金supported by National Institute of Mental Health(NIMH)Grant MH68853the National Memorial Institute for the Prevention of Terrorism(MIPT)and Office of State and Local Government Coordination and Preparedness,US Department of Homeland Security MIPT106-113-2000-020.
文摘Background:Disaster mental health outcomes of individuals may be affected by the families they inhabit,with effects rippling through the entire family system.Existing research on the experience of children in disasters has typically been limited to examining single individuals or,at most,family dyads.Research is needed to explore interactions within families as a whole,including interactions among multiple family members,as well as with community entities in a broad systems approach with dynamic analysis of family systems over time.The purpose of this study was to combine quantitative and qualitative data using structured diagnostic interviews and accompanying open-ended narratives of family members(spouses and children)of survivors of the 9/11 attacks.Methods:This study examined 60 members in 25 families of employees affected by the 9/11 attacks on New York City’s World Trade Center,using a mixed methods approach,collecting quantitative data using full assessments of psychiatric disorders and qualitative data from detailed personal disaster narratives.The employees were a highly 9/11 trauma-exposed group,with about one-fourth developing posttraumatic stress disorder(PTSD).The employees’exposures and PTSD did not regularly appear to propagate straightforwardly to psychopathology in their spouses or children.Based on the impact of disaster experience,4 illustrative families were selected for narrative and family systems analyses.Results:Qualitative analysis of their narratives suggested distinct family system patterns or archetypes that may reflect different ways that families cope with disaster.Conclusion:Findings suggest that family systems and family dynamics may influence not only disaster trauma-exposed members but also other family members in supporting one another and coping with the disaster,with interactions with outside community influences adding further complexity.This information may help guide disaster response efforts to provide psychosocial support targeted to specific family patterns.
文摘Objectives:At the time of the bombing of the federal building in Oklahoma City,Oklahoma(OKC),it was the deadliest terrorist attack in the United States of America.Available research on this incident,and in general,has been quantitative,using deductive methods.The purpose of the current study was to systematically examine professional disaster response workers’emotions elicited spontaneously and in detail as they were experienced over time after a major disaster.This qualitative study will add to existing knowledge of psychopathology and the psychosocial effects of disasters on professional responders,which have not been explored by prior quantitative studies.Methods:A volunteer sample of 181 rescue and recovery workers for the 1995 bombing of the OKC Murrah Federal Building was interviewed approximately 3 years after the bombing.These responders were asked open-ended questions to elicit undirected responses in their own words.In these interviews,they were prompted to describe their feelings at 3 distinct time points:upon their arrival at the bombing scene(“immediately”),in the first 1 week following the bombing,and currently at the time of the interview(“now”).Results:Data items were coded into the 5 themes:Anticipation,Shock and awe,Negative reactions,Positive reactions,and Emotionally unengaged/unaffected.The emotional themes of the responders mapped into 2 conceptual domains.The first domain is related to common human responses to horrible events such as the bombing.The second domain is related to the professional identities of the disaster responders.Conclusions:Specific aspects of the professional responder roles asserted themselves,shaping their emotional responses distinctly from those of the bomb blast survivors.This study identified both negative and positive emotions,which may help identify risk for or resistance to posttraumatic stress disorder(PTSD).
文摘Background:While quantitative research has determined that emotional distress and psychiatric illness among frontline healthcare workers increased with the COVID-19 pandemic,detailed qualitative data describing their personal experiences are needed in order to make appropriate plans to address provider mental health in future pandemics.This study aims to further explore the psychological effects of the pandemic on COVID-19 ICU clinicians and administrators through focus groups.Methods:Two separate 2-h focus groups of physicians were conducted,one with frontline faculty clinicians and another with administrators.Qualitative data analysis was conducted.Results:In September and November 2023,volunteer samples were recruited from the pulmonary and critical care medicine division of The University of Texas Southwestern physicians who served during the pandemic primarily as clinicians(N=6)or in major administrative roles(N=5).Perceptions of both administrators’and clinicians’pandemic experiences were coded into the same 7 qualitative themes:planning,sense of community and isolation,disparities and inequalities,communication and listening,leadership,effects of the pandemic,and emotional/psychiatric/coping responses.Effects of the pandemic were the most coded theme in both groups;second was disparities and inequalities for clinicians and pandemic planning for administrators.Thematic content is summarized separately for clinicians and administrators,illustrated with representative quotes.Conclusion:This study adds detailed qualitative findings to enrich existing quantitative knowledge on frontline COVID-19 workers’emotional responses.Both clinicians and administrators identified helpful and non-helpful institutional responses.These findings are consistent with prior studies of disaster worker experiences and may help to inform efforts to address provider mental health in future pandemics.
基金supported by the Australian coal industry's research(Grant No.C29048).
文摘Open pit mining operations generate significant spoil dumps that need to be characterised for stability to identify potentially unstable slopes.However,the current subjective practice for spoil characterisation often involves tedious and risky field work.To this end,this study demonstrated the use of periodically acquired unmanned aerial vehicle(UAV)-based images over a coal mine spoil dump in New South Wales,Australia.A granular approach that captures the variability of each truck offload pile on a dump was adopted through morphology-based segmentation and ensemble algorithm-based classification which consolidates predictions from multiple classifiers.Overall accuracy of over 90% in the material characterisation based on the classification framework was achieved.The two-dimensional classification outcome was then transformed into three-dimensional(3D)block models using a point-based interpolation approach for stability analysis.The factor of safety derived from the granular approach offered improved assessment of failure risk compared to the conventional approaches,which treat the entire dump as a uniform category.This rapid classification and assessment method proposed in this study will help reduce the uncertainty associated with the variability of spoil dumps in slope stability assessments,thereby enhancing the safety and efficiency of mining operations.
基金supported by the Australian Coal Industry's Research Program(ACARP)(C29048).
文摘Minor errors in the spoil deposition process,such as placing stronger materials with higher shear strength over weaker ones,can lead to potential dump failure.Irregular deposition and inadequate compaction complicate coal spoil behaviour,neces-sitating a robust methodology for temporal monitoring.This study explores using unmanned aerial vehicles(UAV)equipped with red-green-blue(RGB)sensors for efficient data acquisition.Despite their prevalence,raw UAV data exhibit temporal inconsistency,hindering accurate assessments of changes over time which could be attributed to radiometric errors.To this end,the study introduces an empirical line calibration with invariant targets(ELC-IT),for precise calibration across diverse scenes,particularly in the context of UAV imagery used to monitor the evolving nature of spoil dumps.To evaluate the effec-tiveness of this calibration approach,accuracy assessment of an object-based classification is conducted on both calibrated and uncalibrated data.This classification involves several steps:performing segmentation,carrying out feature extraction,and integrating the extracted features and ground truth labels collected over the time period of UAV image capture into machine learning pipelines.Calibrated RGB data exhibit a substantial performance advantage,achieving a 90.7%overall accuracy for spoil pile classification using ensemble(subspace discriminant),representing a noteworthy 7%improvement compared to classifying uncalibrated data.The study highlights the critical role of data calibration in optimising UAV effectiveness for spatio-temporal mine dump monitoring.These findings play a crucial role in informing and refining sustainable management practices within the domain of mine waste management.
基金Funding from the U.S.Army Research Laboratory under agreement No.W911NF-14–2–0005 with Dr.Joe Labukas as project manager supported co-author JMFFunding by the Office of Naval Research grant No.N000141210967 with Dr.David A.Shifler as scientific officer supported co-author LGBThe Bruker Dimension Icon AFM utilized in this work is located in the Boise State University Surface Science Laboratory(SSL),which is part of the FaCT Core Facility,RRID:SCR_024733,that receives support from the National Institutes of Health under the Institutional Development Awards Program of the National Institute of General Medical Sciences via grants#P20GM148321 and P20GM103408,the former of which also partially supports co-authors CME and PHD.
文摘This study investigated the validity and sensitivity of a custom-made shoelace tensile testing system.The aim was to analyze the distribution pattern of shoelace tension in different positions and under different tightness levels during running.Mechanical tests were conducted using 16 weights,and various statistical analyses,including linear regression,Bland-Altman plots,coefficient of variation,and intraclass correlation coefficient,were performed to assess the system’s validity.Fifteen male amateur runners participated in the study,and three conditions(loose,comfortable,and tight)were measured during an upright stance.The system utilized VICON motion systems,a Kistler force plate,and a Photoelectric gate speed measurement system.Results showed a linear relationship between voltage and load at the three sensors(R2≥0.9997).Bland-Altman plots demonstrated 95%prediction intervals within±1.96SD from zero for all sensors.The average coefficient of variation for each sensor was less than 0.38%.Intraclass correlation coefficient values were larger than 0.999(p<0.0001)for each sensor.The peak tension of the front shoelace was greater than that of the front and middle when the shoelace was loose and tight.The rear shoelace had the highest tension force.The study also found that shoelace tension varied throughout the gait cycle during running.Overall,this research provides a novel and validated method for measuring shoelace tensile stress,which has implications for developing automatic shoelace fastening systems.
基金supported by a GRF grant of the Hong Kong Government under HKU 17304524.
文摘We use the Fe Kα emission in X-rays from non-equilibrium ionizing plasmas as a probe to explore the dust in supernova remnants(SNRs). We applied our model to Cassiopeia A(Cas A), a well-studied SNR with plenty of observational data as a test. We use Chandra Advanced CCD Imaging Spectrometer 980 ks data of Cas A, and AtomDB v3.0.9, an atomic database for X-ray plasma spectral modeling, to fit 248 spectra. A two-temperature model is adopted to describe the physical conditions of shocked ejecta and iron-rich plasma. We measure the Fe Kα flux ratio and the centroid difference of the dust and gas contributions. We find strong 6.4 keV line emission components, which indicates that iron-rich dust can survive within Cas A's shocked ejecta. We also find that the Fe Kα complex demonstrates an apparent double-hump structure in some Fe–K rich regions, which may be caused by both dust and multi-ejecta structure in Cas A. The results of Fe Kα structures are consistent with our model for a dust cloud embedded in multi-phase ejecta and suggest the presence of both dust sputtering and drag effects in those regions. It is currently still limited by the low spatial and spectrum resolution for the current X-ray detectors, but should be more useful when the new generation, high-resolution X-ray telescopes come into service.
基金The Herbette Fondation at the University of Lausanne, Switzerland
文摘With increased computational power, reverse-time prestack depth migration（RT-PSDM） has become a preferred imaging tool in seismic exploration, yet its use has remained relatively limited in ground-penetrating radar（GPR） applications. Complex topography alters the wavefield kinematics making for a challenging imaging problem. Model simulations show that topographic variation can substantially distort reflection amplitudes due to irregular wavefield spreading, attenuation anomalies due to irregular path lengths, and focusing and defocusing effects at the surface. The effects are magnified when the topographic variations are on the same order as the depth of investigation––a situation that is often encountered in GPR investigations. Here, I use a full wave-equation RT-PSDM algorithm to image GPR data in the presence of large topographic variability relative to the depth of investigation. The source and receiver wavefields are propagated directly from the topographic surface and this approach inherently corrects for irregular kinematics, spreading and attenuation. The results show that when GPR data are acquired in areas of extreme topography, RT-PSDM can accurately reconstruct reflector geometry as well as reflection amplitude.
基金support from the US Department of Energy,Office of Basic Energy Science under Award no.DE-SC0016333.
文摘Twinning and detwinning behavior,together with slip behavior,are studied in a textured AZ31 magnesium alloy under compressive and tensile strains along the rolling direction(RD)after each interrupted mechanical test via quasi in-situ electron backscattered diffraction technique.The results show that twinning firstly takes place under the compressive strain along the RD.With the increasing compressive strain,{1012}tensile twins firstly nucleate,then propagate,and finally thicken.While under a reversed tensile strain along the RD,detwinning occurs.No nucleation happens during detwinning.Thus,tensile twins can detwin at lower tensile strain,followed by thinning,shortening,and vanishing.Slips are also activated to accommodate the plastic deformation.In the matrix,prismatic slip can only dominate at relatively high strains.Otherwise,basal slip dominates.While in the twins,prismatic slip can activate at lower strains,which is ascribed to the texture reorientation.
基金supported by a grant from the National Social Science Foundation of China (No. 13CTY031)
文摘Background: Self-efficacy has been identified as an important determinant of youth's behavior change including physical activity(PA) participation. However, the dimensionality check of a PA self-efficacy scale has rarely been conducted in China. The current study aims to examine(1) the unidimensionality of a shortened Chinese version of PA self-efficacy scale(S-PASESC);(2) the measurement invariance of S-PASESC across gender and levels of education;(3) the latent factor mean difference between gender and levels of education;(4) the direct effects of self-efficacy on PA by different gender and education levels; and(5) the comparisons of the direct effects of self-efficacy on PA across gender and education levels.Methods: The participants were 5 th through 11 th grade public school students recruited from 7 cities located in different geographic regions of China. The final data include a total of 3003 participants(49.7% boys) who have completed the scales.Results: Confirmatory factor analysis(CFA) test supported the unidimensionality of S-PASESC. The S-PASESC is invariant across gender and 3 levels of education at both configural, full metric, and full scalar levels. Findings from latent mean comparisons showed that boys reported higher PA self-efficacy than girls. Students' perceived PA self-efficacy tend to decrease from elementary to high school. Finally, self-efficacy positively related to PA by groups of different gender and education levels and the relationship between self-efficacy and PA is stronger among middle school boys than girls.Conclusion: Findings suggest S-PASESC is a valid scale for measuring Chinese students' PA self-efficacy.
文摘Background： Active educational video games （AVGs） appear to have a positive effect on elementary school students＇ motivation leading to enhanced learning outcomes. The purpose of this study was to identify the effectiveness of an AVG on elementary school students＇ science knowledge learning, physical activity （PA） level, and interest-based motivation. Methods： In this randomized controlled study, 53 elementary school students were assigned to an experimental condition or a comparison condition. The experimental condition provided an AVG learning environment, whereas the comparison condition was based on sedentary educational video games. Results： The results of repeated measures analysis of variance （ANOVA） on the knowledge test showed that students in both groups performed better on the post-test than they did on the pre-test （p 〈 0.001, η2 = 0.486）, and their post-test scores did not differ significantly. The experimental condition provided a more active environment since the students＇ average heart rates （HRs） were in the Target-Heart-Rate-Zone （HR = 134 bpm）, which was significantly higher than the average HR （103 bpm） from the comparison condition （t = 7.212, p 〈 0.001）. Students in the experimental condition perceived a higher level of situational interest than their counterparts in the comparison group （p 〈 0.01, and η2 = 0.301）. Conclusion： These results suggest that AVGs benefit children more in terms of PA and motivation than traditional video games by providing an enjoyable learning experience and sufficient PA.
文摘Introduction:Since 2015 is the year of FinTech in Taiwan,it is worth investigating the challenges that emerged when banks were encouraged to invest in FinTech companies for collaboration.This study aims to identify the strategic considerations in the process of searching for FinTech investment targets.Case description:This study used a case study investigation of a top-5 bank in Taiwan.The major data sources include the meeting notes of the FinTech investment task force and interviews with the team members.Co-opetition theory was adopted as the theoretical framework and interview questions were derived from the PARTS strategies in co-petition theory.The results relate to:(1)the strategic goals of FinTech investment,(2)the added value from FinTech companies,(3)criteria in selecting candidates in the same FinTech area,(4)choosing to work as either a cooperator or a competitor,and(5)barriers from policies and regulations.Discussion and evaluation:This study has several findings:(1)regulations and policies shape FinTech’s development;(2)banks,technology companies,and customers are not“FinTech ready;”(3)Compare top-down with bottom up strategies;(4)banks and FinTech companies have complex relationships;(5)it is unlikely that Taiwan will produce FinTech disruptors in the near future.Conclusion:The findings and discussion can benefit researchers and administrators in finance-related industries.More studies are desired to observe long-term development in terms of how companies collaborate or compete in specific FinTech areas.
基金supported by the Australian Coal Industry's Research Program(ACARP)[C29048].
文摘The structural integrity of mine dumps is crucial for mining operations to avoid adverse impacts on the triple bottom-line.Routine temporal assessments of coal mine dumps are a compliant requirement to ensure design reconciliation as spoil off-loading continues over time.Generally,the conventional in-situ coal spoil characterisation is inefficient,laborious,hazardous,and prone to experts'observation biases.To this end,this study explores a novel approach to develop automated coal spoil characterisation using unmanned aerial vehicle(UAV)based optical remote sensing.The textural and spectral properties of the high-resolution UAV images were utilised to derive lithology and geotechnical parameters(i.e.,fabric structure and relative density/consistency)in the proposed workflow.The raw images were converted to an orthomosaic using structure from motion aided processing.Then,structural descriptors were computed per pixel to enhance feature modalities of the spoil materials.Finally,machine learning algorithms were employed with ground truth from experts as training and testing data to characterise spoil rapidly with minimal human intervention.The characterisation accuracies achieved from the proposed approach manifest a digital solution to address the limitations in the conventional characterisation approach.
基金the financial support extended by the Higher Education Commission (HEC),Pakistan and National Academy of Sciences (USA),project ID 131,under the PAK-USA S & T Cooperation Program,Award (No.0521315)the HEC,Pakistan for their support in the form of “International Research Support Initiative Program (IRSIP)” to conduct a part of research at Department of Earth Sciences,University of Cambridge,UnitedKingdomfinancial support extended by the Directorate of S & T,KP regarding minerals upgradation
文摘Using marble samples from the Nikani Ghar marble and Nowshera Formation from Northern Pakistan the determination of the temperature of metamorphism was undertaken with the help of calcite-dolomite solvus geothermometer. Two types of marbles, that is, calcite-dolomite marble and quartz-bearing calcite-dolomite marble were selected. Petrographic and scanning electron microscope analysis of dolomite samples indicated different grain sizes. X-ray diffraction technique indicated the calcites MgCO3 content up to 7.93 mol.%. Nikani Ghar marble samples have shown lower contents of MgCO3 as compared to samples from Nowshera Formation. The calcite-dolomite-quartz marble has also showed relatively lower MgCO3 content and hence rather low temperature （-500 ℃）. The temperature reached during peak metamorphism of the investigated marble occurrence, based on calcitedolomite solvus was 628 ℃. Metamorphic temperatures derived from the present study were shown as a linear graph and values were in good agreement with the published literature.
基金supported by the Bejing Municipal Natural Science Foundation (No.2214072)the Interdisciplinary Research Project for Young Teachers of USTB (Fundamental Research Funds for the Central Universities) (FRF-IDRY-20-034)the Office of China Postdoctoral Council under Award No.YJ20200248。
文摘Textured magnesium alloys usually exhibit anisotropic mechanical behavior due to the asymmetric activation of different twinning and slipping modes.This work focuses on the pyramidal slip responses of rolled AZ31 magnesium alloy under two loading conditions,compressive and tensile loading along the normal direction.Under the condition where the compressive loading direction is closely parallel to the c-axis of the unit cell,tensile twinning and basal slips are prohibited, dislocations then active and tend to accumulate at grain boundaries and form dislocation walls.Meanwhile,these dislocations exhibit zigzag morphologies,which result from the cross-slip from {10■1} first-order pyramidal plane to {11■2} second-order pyramidal plane,then back to {10■1} first-order pyramidal plane.Under the condition where tensile twins are prevalent,{10■1} first-order and {11■2} second-order pyramidal dislocations are favorable to be activated.Both types of dislocations behave climb-like dissociations onto the basal plane,forming zigzag dislocations.
