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Relationship between physical activity and specific working memory indicators of depressive symptoms in university students
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作者 Qun Zhao Xing Wang +6 位作者 Shu-Fan Li Peng Wang Xiang Wang Xin Xin Suo-Wang Yin Zhao-Song Yin Li-Juan Mao 《World Journal of Psychiatry》 SCIE 2024年第1期148-158,共11页
BACKGROUND The detection rate of depression among university students has been increasing in recent years,becoming one of the main psychological diseases that endangers their physical and mental health.According to st... BACKGROUND The detection rate of depression among university students has been increasing in recent years,becoming one of the main psychological diseases that endangers their physical and mental health.According to statistics,self-harm and suicide,for which there is no effective intervention,are the second leading causes of death.AIM To explore the relationship between different elements and levels of physical activity and college students’depression-symptom-specific working memory indicators.METHODS Of 143 college students were analyzed using the Beck Depression Self-Rating Scale,the Physical Activity Rating Scale,and the Working Memory Task.RESULTS There was a significant difference between college students with depressive symptoms and healthy college students in completing verbal and spatial working memory(SWM)tasks correctly(all P<0.01).Physical Activity Scale-3 scores were significantly and positively correlated with the correct rate of the verbal working memory task(r=0.166)and the correct rate of the SWM task(r=0.210)(all P<0.05).There were significant differences in the correct rates of verbal and SWM tasks according to different exercise intensities(all P<0.05)and different exercise durations(all P<0.05),and no significant differences in the correct rates of verbal and SWM tasks by exercise frequency(all P>0.05).CONCLUSION An increase in physical exercise among college students,particularly medium-and high-intensity exercise and exercise of 30 min or more,can improve the correct rate of completing working memory tasks. 展开更多
关键词 Physical activity Depression symptoms University students Working memory
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The Study of the Physical Properties and Energy Sources of Five Luminous Type Ibc Supernovae
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作者 白松瑶 王涛 +3 位作者 王善钦 甘文沛 王浏毅 梁恩维 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第12期34-56,共23页
In this paper,we study five luminous supernovae(LSNe)Ibc(SN 2009ca,ASASSN-15mj,SN 2019omd,SN 2002ued,and SN 2021bmf)whose peak absolute magnitudes M_(peakare)≈-19.5 to-21 mag by fitting their multi-band light curves(... In this paper,we study five luminous supernovae(LSNe)Ibc(SN 2009ca,ASASSN-15mj,SN 2019omd,SN 2002ued,and SN 2021bmf)whose peak absolute magnitudes M_(peakare)≈-19.5 to-21 mag by fitting their multi-band light curves(LCs)with different energy source models.We find that SN 2009ca might be powered by the^(56)Ni model since the required^(56)Ni mass(0.56 M_(⊙))is comparable to those of energetic SNe Ic,while the rest four SNe cannot be accounted for the^(56)Ni model since their derived^(56)Ni masses are(?)1 M_(⊙)or the ratios of the^(56)Ni mass to the ejecta mass are larger than 0.2.This indicates that some LSNe might be powered by^(56)Ni decay,while most of them need additional energy sources.We then use the magnetar plus^(56)Ni model and the fallback plus^(56)Ni model to fit the LCs of the four LSNe that cannot be explained by the^(56)Ni model,finding that the two models can account for the four SNe,and the derived parameters are comparable to those of LSNe or superluminous SNe in the literature,if they were(mainly)powered by magnetars or fallback.We suggest that the magnetar plus^(56)Ni model is more reasonable than the fallback plus^(56)Ni model,since the validity of the fallback plus^(56)Ni model depends on the value of accretion efficiency(η)and favors a largeηvalue,and the magnetar plus^(56)Ni model yields smallerχ^(2)/dof values.It should be pointed out that,however,the fallback plus^(56)Ni model is still a promising model that can account for the four SNe in our sample as well as other LSNe. 展开更多
关键词 Stars-(stars:)supernovae general-stars MAGNETARS
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Influence of physical education on anxiety, depression, and selfesteem among college students
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作者 Hai-Yan Fu Jing Wang Jia-Xi Hu 《World Journal of Psychiatry》 SCIE 2023年第12期1121-1132,共12页
BACKGROUND Physical education is pivotal in our country’s education reform.Urban schools have notably enhanced the intensity of physical education in recent years.However,the effects of physical education on students... BACKGROUND Physical education is pivotal in our country’s education reform.Urban schools have notably enhanced the intensity of physical education in recent years.However,the effects of physical education on students'anxiety,depression,and self-esteem levels,as well as their interrelations,remain unexplored.Compared with the domestic norms,SAS and SDS scores were higher,and SES scores were lower(P<0.05).Among the participants,210(43.93%)had PARS-3 scores below 20,94(19.67%)had scores of 20-42,and 174(36.40%)had scores above 42.After adjusting for daily sleep time,gender,being an only child,major,father’s educational background,mother’s educational background,and family residence,PARS-3 scores were independent influencing factors for anxiety,depression,and low self-esteem(P<0.05).The AUC of PARS-3 scores predicting anxiety,depression,and low self-esteem were 0.805(0.760-0.849),0.799(0.755-0.843),and 0.831(0.788-0.874),respectively.The sensitivities were 0.799,0.801,and 0.748,and the specificities were 0.743,0.716,and 0.814,respectively.PARS-3 was negatively correlated with SAS and SDS scores(r=-0.566,-0.621,both P<0.001)and positively correlated with SES scores(r=-0.621,P<0.001).SES scores were negatively correlated with SAS and SDS scores(r=-0.508,r=-0.518,both P<0.001).CONCLUSION The amount of physical activity is negatively correlated with anxiety and depression degree and positively correlated with self-esteem degree. 展开更多
关键词 Physical education STUDENT ANXIETY DEPRESSION SELF-ESTEEM INFLUENCE
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Correlation and pathways of behavioral activation systems mediating physical activity level and depressive symptoms among college students
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作者 Jiang-Hua Zhu Shu-Fan Li +4 位作者 Peng Wang Xin Xin Qun Zhao Si-Cheng Chen Xing Wang 《World Journal of Psychiatry》 SCIE 2023年第10期784-792,共9页
BACKGROUND Depression is a common mental disorder among college students.The main symptoms include being persistent low mood,sad emotional experiences,lack of pleasure,listlessness,and impaired cognitive function acco... BACKGROUND Depression is a common mental disorder among college students.The main symptoms include being persistent low mood,sad emotional experiences,lack of pleasure,listlessness,and impaired cognitive function accompanied by tendencies of self-harm and suicide.AIM To clarify the pathways and effects of the behavioral activation system between physical activity and depressive symptoms in college students with depressive symptoms.METHODS This cross-sectional research screened 3047 college students.Of these,472 had depressive symptoms,with a depression detection rate of 15.49%.Furthermore,442 college students with depressive symptoms were analyzed.A one-way analysis of variance and Pearson’s correlation,linear regression,and structural equation modeling analyses were used to explore the correlations and pathways of the interactions between the variables.RESULTS Depressive symptoms were significantly negatively correlated with physical activity(r=-0.175,P<0.001),the behavioral activation system(r=-0.197,P<0.001),and drive(r=-0.113,P=0.017).Furthermore,it was negatively correlated with fun-seeking(FS)(r=-0.055,P=0.251);however,it was not significant.Physical activity was significantly positively correlated with reward responsiveness(RR)(r=0.141,P=0.003)and drive(r=0.124,P=0.009)and not significantly positively correlated with FS(r=0.090,P=0.058).The mediating effect of RR between physical activity and depressive symptoms was significant[B=-0.025,95%confidence interval(95%CI):-0.051 to-0.008,P=0.001].The direct and total effects of physical activity on depressive symptoms and were significant(B=-0.150,95%CI:-0.233 to-0.073,P<0.001;B=-0.175,95%CI:-0.260 to-0.099,P<0.001),respectively.CONCLUSION As physical activity levels increased,depression scores among college students decreased.The mediating effect of RR between physical activity and depressive symptoms was significant.Therefore,colleges and universities should encourage college students with depression to increase their physical activity and improve their behavioral activation system.Particular attention should be paid to RR,which may reduce the prevalence of depressive symptoms. 展开更多
关键词 College students Physical activity Depressive symptoms Behavioral activation system Mediating role
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Effects of sports on school adaptability, resilience and cell phone addiction tendency of high school students
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作者 Li-Qiang Zhang Hui-Na Gao 《World Journal of Psychiatry》 SCIE 2023年第8期563-572,共10页
BACKGROUND Sport help promote healthy physical and mental development of high school students.To date,there have been few studies on the effect of sport on school adaptability,resilience and cell phone addiction tende... BACKGROUND Sport help promote healthy physical and mental development of high school students.To date,there have been few studies on the effect of sport on school adaptability,resilience and cell phone addiction tendency of high school students.AIM To explore the effects of sports on school adaptability,resilience and cell phone addiction of high school students.METHODS A stratified random sampling method was used to select 600 students from two high schools in Lhasa,and Physical Activity Rating Scale,School Adjustment Scale for High School Students,Chinese Adolescents Resilience Scale,and Mobile Phone Addiction Index were used for field questionnaire survey.RESULTS Sport was positively correlated with school adaptability and resilience(P<0.01),school adaptability was positively correlated with resilience(P<0.01)and cell phone addiction was negatively correlated with sports,school adaptability and resilience(P<0.01).The direct effect of sport on cell phone addiction was significant(P<0.001),accounting for 20.51%of the total effect.The mediating effect of school adaptability on sport and cell phone addiction was significant(P<0.001),accounting for 17.38%and 35.36%of the total effect value,respectively.School adjustment and resilience had a significant chain-mediated effect on sport and cell phone addiction(P<0.001),accounting for 26.75%of the total effect.CONCLUSION Sport affected the cell phone addiction tendency of senior high school students through the mediating effect of school adaptability and resilience,and through the chain mediation effect of both. 展开更多
关键词 Sport High school students School adaptability RESILIENCE Cell phone addiction
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The relationship between transport-to-school habits and physical activity in a sample of New Zealand adolescents 被引量:1
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作者 Chiew Ching Kek Enrique García Bengoechea +1 位作者 John C.Spence Sandra Mandic 《Journal of Sport and Health Science》 SCIE 2019年第5期463-470,共8页
Objectives:Adolescents using active transport(AT)to school have higher levels of physical activity(PA)compared with motorized transport(MT)users.This study compared school day and weekend day PA in adolescents using A... Objectives:Adolescents using active transport(AT)to school have higher levels of physical activity(PA)compared with motorized transport(MT)users.This study compared school day and weekend day PA in adolescents using AT,MT,or combined AT and MT(AT + MT)to travel to school.Methods:Adolescents(n= 314;age:14.7±1.4 years;32.8% boys)from Dunedin(New Zealand)wore an accelerometer for 7 days and completed a self-reported survey regarding mode of transport to school(73 AT,56 AT + MT,and 185 MT).Data were analyzed using t tests,analysis of variance,and χ2 tests.Results:Although the proportion of adolescents meeting PA guidelines significantly differed among transport groups(AT,47.9%;AT + MT,46.4%;MT,33.5%;p=0.048;overall,39.2%),the observed differences were due mainly to girls.Compared with MT,AT and AT+MT engaged in more moderate-to-vigorous PA(MVPA)per day(AT:61.2 ± 23.2 min;AT+MT:59.6 ± 21.7 min;MT:52.5 ± 19.6 min;p = 0.004;p<0.001,adjusted for gender),per school day and before school.Immediately after school(15:00-16:00),AT engaged in significantly more MVPA compared with AT + MT and MT.No differences in MVPA between the groups were observed in the late afternoon/early evening period during school days or on weekend days.Conclusion:Compared with MT users,adolescent girls using AT or AT + MT accumulated more MVPA during school commute time.AT + MT to school is also a plausible way to increase adolescent girls’ PA when AT only is not feasible. 展开更多
关键词 ACCELEROMETER ADOLESCENT Physical activity SCHOOLS Transportation WALKING
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The rise of supercapacitor diodes:Current progresses and future challenges
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作者 马鸿云 马凌霄 +1 位作者 毕华盛 兰伟 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期10-20,共11页
Supercapacitor has been widely known as a representative electrochemical energy storage device with high power density and long lifespan.Recently,with the deeper understanding of its charge storage mechanism,unidirect... Supercapacitor has been widely known as a representative electrochemical energy storage device with high power density and long lifespan.Recently,with the deeper understanding of its charge storage mechanism,unidirectional-charging supercapacitor,also called supercapacitor diode(CAPode),is successfully developed based on the ion-sieving effect of its working electrode towards electrolyte ions.Because CAPode integrates mobile ion and mobile electron in one hybrid circuit,it has a great potential in the emerging fields of ion/electron coupling logic operations,human–machine interface,neural network interaction,and in vivo diagnosis and treatment.Accordingly,we herein elucidate the working mechanism and design philosophy of CAPode,and summarize the electrode materials that are suitable for constructing CAPode.Meanwhile,some other supercapacitor-based devices beyond CAPode are also introduced,and their potential applications are instructively presented.Finally,we outline the challenges and chances of CAPode-related techniques. 展开更多
关键词 supercapacitor diode ion-sieving effect ion/electron coupling circuit logic operation
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Epitaxial growth of ultrathin gallium films on Cd(0001)
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作者 李佐 石明霞 +2 位作者 姚钢 陶敏龙 王俊忠 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期722-727,共6页
Growth and electronic properties of ultrathin Ga films on Cd(0001) are investigated by low-temperature scanning tunneling microscopy(STM) and density functional theory(DFT) calculations. It is found that Ga films exhi... Growth and electronic properties of ultrathin Ga films on Cd(0001) are investigated by low-temperature scanning tunneling microscopy(STM) and density functional theory(DFT) calculations. It is found that Ga films exhibit the epitaxial growth with the pseudomorphic 1×1 lattice. The Ga islands deposited at 100 K show a ramified shape due to the suppressed edge diffusion and corner crossing. Furthermore, the majority of Ga islands reveal flat tops and a preferred height of three atomic layers, indicating the electronic growth at low temperature. Annealing to room temperature leads to not only the growth mode transition from electronic growth to conventional Stranski–Krastanov growth, but also the shape transition from ramified islands to smooth compact islands. Scanning tunneling spectroscopy(STS) measurements reveal that the Ga monolayer exhibits metallic behavior. DFT calculations indicate that all the interfacial Ga atoms occupy the energetically favorable hcp-hollow sites of the substrate. The charge density difference analysis demonstrates that the charge transfer from the Cd substrate to the Ga atoms is negligible, and there is weak interaction between Ga atoms and the Cd substrate. These results shall shed important light on fabrication of ultrathin Ga films on metal substrates with novel physical properties. 展开更多
关键词 gallium films electronic growth STM/STS density functional theory
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Image segmentation of exfoliated two-dimensional materials by generative adversarial network-based data augmentation
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作者 程晓昱 解晨雪 +6 位作者 刘宇伦 白瑞雪 肖南海 任琰博 张喜林 马惠 蒋崇云 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期112-117,共6页
Mechanically cleaved two-dimensional materials are random in size and thickness.Recognizing atomically thin flakes by human experts is inefficient and unsuitable for scalable production.Deep learning algorithms have b... Mechanically cleaved two-dimensional materials are random in size and thickness.Recognizing atomically thin flakes by human experts is inefficient and unsuitable for scalable production.Deep learning algorithms have been adopted as an alternative,nevertheless a major challenge is a lack of sufficient actual training images.Here we report the generation of synthetic two-dimensional materials images using StyleGAN3 to complement the dataset.DeepLabv3Plus network is trained with the synthetic images which reduces overfitting and improves recognition accuracy to over 90%.A semi-supervisory technique for labeling images is introduced to reduce manual efforts.The sharper edges recognized by this method facilitate material stacking with precise edge alignment,which benefits exploring novel properties of layered-material devices that crucially depend on the interlayer twist-angle.This feasible and efficient method allows for the rapid and high-quality manufacturing of atomically thin materials and devices. 展开更多
关键词 two-dimensional materials deep learning data augmentation generating adversarial networks
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Evolution of molecular structure of TATB under shock loading from transient Raman spectroscopic technique
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作者 Hongliang Kang Xue Yang +5 位作者 Wenshuo Yuan Lei Yang Xinghan Li Fusheng Liu Zhengtang Liu Qijun Liu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期613-620,共8页
By combination of the transient Raman spectroscopic measurement and the density functional theoretical calculations,the structural evolution and stability of TATB under shock compression was investigated.Due to the im... By combination of the transient Raman spectroscopic measurement and the density functional theoretical calculations,the structural evolution and stability of TATB under shock compression was investigated.Due to the improvement in synchronization control between two-stage light gas gun and the transient Raman spectra acquisition,as well as the sample preparation,the Raman peak of the N-O mode of TATB was firstly observed under shock pressure up to 13.6 GPa,noticeably higher than the upper limit of 8.5 GPa reported in available literatures.By taking into account of the continuous shift of the main peak and other observed Raman peaks,we did not distinguish any structural transition or any new species.Moreover,both the present Raman spectra and the time-resolved radiation of TATB during shock loading showed that TATB exhibits higher chemical stability than previous declaration.To reveal the detailed structural response and evolution of TATB under compression,the density functional theoretical calculations were conducted,and it was found that the pressure make N-O bond lengths shorter,nitro bond angles larger,and intermolecular and intra-molecular hydrogen bond interactions enhanced.The observed red shift of Raman peak was ascribed to the abnormal enhancement of H-bound effect on the scissor vibration mode of the nitro group. 展开更多
关键词 TATB Raman spectra Structural evolution Shock loading
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An improved TDE technique for derivation of 2D turbulence structures based on GPI data in toroidal plasma
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作者 王威策 程钧 +12 位作者 石中兵 严龙文 黄治辉 弋开阳 吴娜 何钰 邹千 陈熙 张文 陈建 聂林 季小全 钟武律 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第3期131-137,共7页
This paper reports an improved time-delay estimation(TDE)technique for the derivation of turbulence structures based on gas-puff imaging data.The improved TDE technique,integrating an inverse timing search and hierarc... This paper reports an improved time-delay estimation(TDE)technique for the derivation of turbulence structures based on gas-puff imaging data.The improved TDE technique,integrating an inverse timing search and hierarchical strategy,offers superior accuracy in calculating turbulent velocity field maps and analyzing blob dynamics,which has the power to obtain the radial profiles of equilibrium poloidal velocity,blob size and its radial velocity,even the fluctuation analysis,such as geodesic acoustic modes and quasi-coherent mode,etc.This improved technique could provide important 2D information for the study of edge turbulence and blob dynamics,advancing the understanding of edge turbulence physics in fusion plasmas. 展开更多
关键词 gas-puff imaging TDE method TURBULENCE velocity field map
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Decompositions of the Kadomtsev-Petviashvili equation and their symmetry reductions
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作者 陈孜童 贾曼 +1 位作者 郝夏芝 楼森岳 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期150-159,共10页
Starting with a decomposition conjecture,we carefully explain the basic decompositions for the Kadomtsev-Petviashvili(KP)equation as well as the necessary calculation procedures,and it is shown that the KP equation al... Starting with a decomposition conjecture,we carefully explain the basic decompositions for the Kadomtsev-Petviashvili(KP)equation as well as the necessary calculation procedures,and it is shown that the KP equation allows the Burgers-STO(BSTO)decomposition,two types of reducible coupled BSTO decompositions and the BSTO-KdV decomposition.Furthermore,we concentrate ourselves on pointing out the main idea and result of Bäcklund transformation of the KP equation based on a special superposition principle in the particular context of the BSTO decompositions.Using the framework of standard Lie point symmetry theory,these decompositions are studied and the problem of computing the corresponding symmetry constraints is treated. 展开更多
关键词 Kadomtsev-Petviashvili(KP)equation decomposition Bäcklund transformation symmetry reduction
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Core-level spectroscopy of the photodissociation process of BrCN molecule
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作者 周坤 王涵 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期176-182,共7页
Fewest-switches surfacing hopping(FSSH) simulations have been performed with the high-level multi-reference electronic structure method to explore the coupled electronic and nuclear dynamics upon photoexcitation of cy... Fewest-switches surfacing hopping(FSSH) simulations have been performed with the high-level multi-reference electronic structure method to explore the coupled electronic and nuclear dynamics upon photoexcitation of cyanogen bromide(BrCN). The potential energy surfaces(PES) of BrCN are charted as functions of the Jacobi coordinates(R, θ). An indepth examination of the FSSH trajectories reveals the temporal dynamics of the molecule and the population changes of the lowest twelve states during BrCN's photodissociation process, which presents a rich tapestry of dynamical information.Furthermore, the carbon K-edge x-ray absorption spectroscopy(XAS) is calculated with multi-reference inner-shell spectral simulations. The rotation of the CN fragment and the elongation of the C–Br bond are found to be the reason for the peak shifting in the XAS. Our findings offer a nuanced interpretation for inner-shell probe investigations of BrCN, setting the stage for a deeper understanding of the photodissociation process of cyanogen halides molecules. 展开更多
关键词 x-ray absorption spectroscopy PHOTODISSOCIATION fewest-switches surface hopping
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Holevo bound independent of weight matrices for estimating two parameters of a qubit
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作者 牛畅 郁司夏 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期137-143,共7页
Holevo bound plays an important role in quantum metrology as it sets the ultimate limit for multi-parameter estimations,which can be asymptotically achieved.Except for some trivial cases,the Holevo bound is implicitly... Holevo bound plays an important role in quantum metrology as it sets the ultimate limit for multi-parameter estimations,which can be asymptotically achieved.Except for some trivial cases,the Holevo bound is implicitly defined and formulated with the help of weight matrices.Here we report the first instance of an intrinsic Holevo bound,namely,without any reference to weight matrices,in a nontrivial case.Specifically,we prove that the Holevo bound for estimating two parameters of a qubit is equivalent to the joint constraint imposed by two quantum Cramér–Rao bounds corresponding to symmetric and right logarithmic derivatives.This weightless form of Holevo bound enables us to determine the precise range of independent entries of the mean-square error matrix,i.e.,two variances and one covariance that quantify the precisions of the estimation,as illustrated by different estimation models.Our result sheds some new light on the relations between the Holevo bound and quantum Cramer–Rao bounds.Possible generalizations are discussed. 展开更多
关键词 quantum metrology quantum Fisher information Holevo bound quantum multi-parameter estimation
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An Evidence-Based CoCoSo Framework with Double Hierarchy Linguistic Data for Viable Selection of Hydrogen Storage Methods
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作者 Raghunathan Krishankumar Dhruva Sundararajan +1 位作者 K.S.Ravichandran Edmundas Kazimieras Zavadskas 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2845-2872,共28页
Hydrogen is the new age alternative energy source to combat energy demand and climate change.Storage of hydrogen is vital for a nation’s growth.Works of literature provide different methods for storing the produced h... Hydrogen is the new age alternative energy source to combat energy demand and climate change.Storage of hydrogen is vital for a nation’s growth.Works of literature provide different methods for storing the produced hydrogen,and the rational selection of a viable method is crucial for promoting sustainability and green practices.Typically,hydrogen storage is associated with diverse sustainable and circular economy(SCE)criteria.As a result,the authors consider the situation a multi-criteria decision-making(MCDM)problem.Studies infer that previous models for hydrogen storage method(HSM)selection(i)do not consider preferences in the natural language form;(ii)weights of experts are not methodically determined;(iii)hesitation of experts during criteria weight assessment is not effectively explored;and(iv)three-stage solution of a suitable selection of HSM is unexplored.Driven by these gaps,in this paper,authors put forward a new integrated framework,which considers double hierarchy linguistic information for rating,criteria importance through inter-criteria correlation(CRITIC)for expert weight calculation,evidence-based Bayesian method for criteria weight estimation,and combined compromise solution(CoCoSo)for ranking HSMs.The applicability of the developed framework is testified by using a case example of HSM selection in India.Sensitivity and comparative analysis reveal the merits and limitations of the developed framework. 展开更多
关键词 Hydrogen storage methods double hierarchy hesitant fuzzy linguistic term set evidence theory CoCoSo method sustainability circular economy
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Geometries and electronic structures of Zr_(n)Cu(n=2–12) clusters: A joint machine-learning potential density functional theory investigation
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作者 王一志 崔秀花 +3 位作者 刘静 井群 段海明 曹海宾 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期595-602,共8页
Zr-based amorphous alloys have attracted extensive attention because of their large glassy formation ability, wide supercooled liquid region, high elasticity, and unique mechanical strength induced by their icosahedra... Zr-based amorphous alloys have attracted extensive attention because of their large glassy formation ability, wide supercooled liquid region, high elasticity, and unique mechanical strength induced by their icosahedral local structures.To determine the microstructures of Zr–Cu clusters, the stable and metastable geometry of Zr_(n)Cu(n=2–12) clusters are screened out via the CALYPSO method using machine-learning potentials, and then the electronic structures are investigated using density functional theory. The results show that the Zr_(n)Cu(n ≥ 3) clusters possess three-dimensional geometries, Zr_(n)Cu(n≥9) possess cage-like geometries, and the Zr_(12)Cu cluster has icosahedral geometry. The binding energy per atom gradually gets enlarged with the increase in the size of the clusters, and Zr_(n)Cu(n=5,7,9,12) have relatively better stability than their neighbors. The magnetic moment of most Zr_(n)Cu clusters is just 1μB, and the main components of the highest occupied molecular orbitals(HOMOs) in the Zr_(12)Cu cluster come from the Zr-d state. There are hardly any localized two-center bonds, and there are about 20 σ-type delocalized three-center bonds. 展开更多
关键词 geometries and electronic structures magnetic and chemical bonds machine learning potentials Zr–Cu clusters
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Effect of overheating-induced minor addition on Zr-based metallic glasses
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作者 杨福 薄振兴 +7 位作者 黄瑶 王雨田 孙博阳 鲁振 孙保安 柳延辉 汪卫华 潘明祥 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期118-125,共8页
Melt treatment is well known to have an important influence on the properties of metallic glasses(MGs).However,for the MGs quenched from different melt temperatures with a quartz tube,the underlying physical origin re... Melt treatment is well known to have an important influence on the properties of metallic glasses(MGs).However,for the MGs quenched from different melt temperatures with a quartz tube,the underlying physical origin responsible for the variation of properties remains poorly understood.In the present work,we systematically studied the influence of melt treatment on the thermal properties of a Zr50Cu36Al14 glass-forming alloy and unveiled the microscopic origins.Specifically,we quenched the melt at different temperatures ranging from 1.1Tl to 1.5Tl(Tl is the liquidus temperature)to obtain melt-spun MG ribbons and investigated the variation of thermal properties of the MGs upon heating.We found that glass transition temperature,Tg,increases by as much as 36 K,and the supercooled liquid region disappears in the curve of differential scanning calorimetry when the melt is quenched at a high temperature up to 1.5Tl.The careful chemical analyses indicate that the change in glass transition behavior originates from the incorporation of oxygen and silicon in the molten alloys.The incorporated oxygen and silicon can both enhance the interactions between atoms,which renders the cooperative rearrangements of atoms difficult,and thus enhances the kinetic stability of the MGs. 展开更多
关键词 metallic glass thermal properties melt treatment OVERHEATING oxygen content
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Shock Raman spectra and structural transformation of powdered TKX-50 by the plate impact experiments combined with real-time Raman detection
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作者 Xue Yang Qijun Liu +3 位作者 Yundan Gan Lei Yang Zhengtang Liu Fusheng Liu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期158-162,共5页
As an energetic material of great interest,the work capacity of dihydroxylammonium 5,5’-bistetrazole-1,1’-diolate(TKX-50)has been questioned recently.Although some research groups have explored the reasons for the l... As an energetic material of great interest,the work capacity of dihydroxylammonium 5,5’-bistetrazole-1,1’-diolate(TKX-50)has been questioned recently.Although some research groups have explored the reasons for the low working ability of TKX-50,the plane impact experiment on powdered TKX-50 is obviously closer to the practical application,and the conclusions based on this are more guiding.Hence,we performed shock Hugoniot measurements of powdered TKX-50 between 5.65 and 16.29 GPa.The plane impact experiments of powdered TKX-50 were carried out and the shocked Raman spectra were collected.By Raman spectroscopy analysis,a new peak of powdered TKX-50 was found between19.47 GPa and 24.96 GPa,which may be caused by decomposition/phase transition and was related with the low work capacity. 展开更多
关键词 Powdered TKX-50 HUGONIOT RAMAN DECOMPOSITION Phase transition
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Quantitative determination of the critical points of Mott metal–insulator transition in strongly correlated systems
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作者 牛月坤 倪煜 +4 位作者 王建利 陈雷鸣 邢晔 宋筠 冯世平 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期647-652,共6页
Mottness is at the heart of the essential physics in a strongly correlated system as many novel quantum phenomena occur in the metallic phase near the Mott metal–insulator transition. We investigate the Mott transiti... Mottness is at the heart of the essential physics in a strongly correlated system as many novel quantum phenomena occur in the metallic phase near the Mott metal–insulator transition. We investigate the Mott transition in a Hubbard model by using the dynamical mean-field theory and introduce the local quantum state fidelity to depict the Mott metal–insulator transition. The local quantum state fidelity provides a convenient approach to determining the critical point of the Mott transition. Additionally, it presents a consistent description of the two distinct forms of the Mott transition points. 展开更多
关键词 critical point metal–insulator transition local quantum state fidelity strongly correlated system quasiparticle coherent weight
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Lobe-dominatedγ-Ray Emission of Compact Symmetric Objects
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作者 Ying-Ying Gan Hai-Ming Zhang +2 位作者 Xing Yang Ying Gu Jin Zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第2期196-205,共10页
Theγ-ray emitting compact symmetric objects(CSOs)PKS 1718-649,NGC 3894,and TXS 0128+554 are lobedominated in the radio emission.In order to investigate theirγ-ray radiation properties,we analyze the~14yr Fermi/LAT o... Theγ-ray emitting compact symmetric objects(CSOs)PKS 1718-649,NGC 3894,and TXS 0128+554 are lobedominated in the radio emission.In order to investigate theirγ-ray radiation properties,we analyze the~14yr Fermi/LAT observation data of the three CSOs.They all show the low luminosity(1041-1043 erg s-1)and no significant variability in theγ-ray band.Theirγ-ray average spectra can be well fitted by a power-law function.These properties ofγ-rays are clearly different from theγ-ray emitting CSOs CTD 135 and PKS 1413+135,for which theγ-rays are produced by a restarted aligned jet.In the L_(γ)-Γ_(γ)plane,the three CSOs are also located at the region occupied by radio galaxies(RGs)while CTD 135 and PKS 1413+135 display a similar feature to blazars.Together with a similar radio emission property toγ-ray emitting RGs Cen A and Fornax A,we speculate that theγ-rays of the three CSOs stem from their extended mini-lobes.The broadband spectral energy distributions of the three CSOs can be well explained by the two-zone leptonic model,where theirγ-rays are produced by the inverse Compton process of the relativistic electrons in extended regions.By extrapolating the observed Fermi/LAT spectra to the very high energy band,we find that TXS 0128+554 among the three CSOs may be detected by the Cherenkov Telescope Array in the future. 展开更多
关键词 GALAXIES active-galaxies jets-radio continuum galaxies-gamma-rays GALAXIES
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