期刊文献+
共找到625篇文章
< 1 2 32 >
每页显示 20 50 100
Comment on Alhojairi et al. (2024) ‘Assessment of nurses’ workplace silence behavior motives: A cross-sectional study’
1
作者 Tina Vuohijoki 《International Journal of Nursing Sciences》 2025年第2期200-201,共2页
Dear Editor,I am writing in response to the article“Assessment of nurses’workplace silence behavior motives:A cross-sectional study”by Alhojairi et al.published in the September 2024 issue of the International Jour... Dear Editor,I am writing in response to the article“Assessment of nurses’workplace silence behavior motives:A cross-sectional study”by Alhojairi et al.published in the September 2024 issue of the International Journal of Nursing Sciences[1].This is a letter written by a nurse with 10 years of clinical work experience and a personal interest in team dynamics.I appreciate the authors'recommendations on mitigating workplace silence among nurses to enhance clinical work development,and I believe their proposals could be expanded further. 展开更多
关键词 cross sectional study enhance clinical work developmentand motives clinical work development team dynamics workplace silence nurses mitigating workplace silence
暂未订购
Frailty,multimorbidity and quality of life in an ageing population in Africa:a cross-sectional,population-based study in rural and urban Rwanda
2
作者 Michael Boah Callixte Cyuzuzo +6 位作者 Francois Uwinkindi Chester Kalinda Tsion Yohannes Carolyn Greig Justine Davies Lisa R Hirschhorn Alemayehu Amberbir 《Family Medicine and Community Health》 2025年第4期79-87,共9页
Objective As populations age,multimorbidity and frailty have emerged as major health challenges.While their associations with disability and mortality are well documented,their impact on quality of life(QoL)in sub-Sah... Objective As populations age,multimorbidity and frailty have emerged as major health challenges.While their associations with disability and mortality are well documented,their impact on quality of life(QoL)in sub-Saharan Africa remains underexplored.We examined the associations between frailty,multimorbidity and QoL among older adults in Rwanda.Design A cross-sectional population-based study.Multimorbidity was defined as having two or more chronic conditions,including hypertension,diabetes,heart disease and mental health conditions.Frailty scores were derived using the Fried phenotype,and QoL was measured using the European Health Instrument Survey-Quality of Life index(scaled 0%–100%).Sequential linear regression models were used to examine independent associations.Setting Rural and urban settings of Rwanda.Participant We analysed data from 4369 adults(≥40 years).Results The mean QoL score was 48.2%(±15.6).Frailty and multimorbidity prevalence were 14.5%(95%CI 13.5 to 15.6)and 55.2%(95%CI 53.7 to 56.6),respectively,while 55.0%(95%CI 53.3 to 56.3)were classified as prefrail.Frailty and multimorbidity are independently associated with poorer QoL.Compared with robust individuals,prefrail and frail individuals experienced a 3.66(95%CI−4.63 to–2.70)and 7.30(95%CI−8.76 to–5.83)percentage point reduction in QoL,respectively.Multimorbidity was associated with a 4.66%(95%CI−5.54 to–3.79)point decrease in QoL.Impairments in activities of daily living partly mediated these associations.Conclusions Frailty and multimorbidity showed a strong negative association with QoL,with frailty having a stronger effect.These findings underscore the need for age-responsive healthcare strategies,including frailty screening and integrated chronic care,to enhance QoL among older adults in Rwanda. 展开更多
关键词 quality life qol quality life FRAILTY cross sectional study sub saharan africa population based study MULTIMORBIDITY rural urban settings
原文传递
Kitchen Ventilation Attenuate the Association of Solid Fuel Use with Sarcopenia: A Cross-Sectional and Prospective Study
3
作者 Yinghao Yuchi Wei Liao +8 位作者 Jia Qiu Ruiying Li Ning Kang Xiaotian Liu Wenqian Huo Zhenxing Mao Jian Hou Lei Zhang Chongjian Wang 《Biomedical and Environmental Sciences》 2025年第4期511-515,共5页
Rapid population aging has led to an increased focus on age-related conditions such as sarcopenia.causing loss of muscle mass and strength^([1,2]). Sarcopenia is associated with adverse outcomes,including falls, funct... Rapid population aging has led to an increased focus on age-related conditions such as sarcopenia.causing loss of muscle mass and strength^([1,2]). Sarcopenia is associated with adverse outcomes,including falls, functional decline, frailty, and mortality, which can lower the quality of life and shorten lifespan^([1,2]). 展开更多
关键词 rapid population aging functional decline cross sectional study SARCOPENIA prospective study population aging solid fuel use muscle mass
暂未订购
Association between arterial stiffness and geriatric status:results of cross-sectional study
4
作者 Alexandra V Luzina Ksenia A Eruslanova +3 位作者 Sergey R Gilyarevsky Nadezhda K Runikhina Yulia V Kotovskaya Olga N Tkacheva 《Journal of Geriatric Cardiology》 2025年第11期941-947,共7页
Arterial stiffness is considered an important indicator reflecting age-related changes in the vascular wall[1]and the risk of developing comorbidities,[2]primarily cardiovascular diseases.[3]Cardiovascular diseases re... Arterial stiffness is considered an important indicator reflecting age-related changes in the vascular wall[1]and the risk of developing comorbidities,[2]primarily cardiovascular diseases.[3]Cardiovascular diseases remain the leading cause of death worldwide.Many factors influence the rate of arterial aging.Research results have confirmed that arterial wall stiffness increases with an increasing number of risk factors,[4]as each of them acts independently through various mechanisms,adversely affecting the structure and function of the cardiovascular system. 展开更多
关键词 arterial stiffness geriatric status cross sectional study arterial wall stiffness vascular wall cardiovascular diseases cardiovascular diseases risk factors age related changes
暂未订购
A Comparative Analysis of Subtyping Methodologies on Cross-sectional sMRI Data
5
作者 Shirui Zhang Baitong Zhang +14 位作者 Kun Zhao Zhuangzhuang Li Pan Wang Dawei Wang Chengyuan Song Jie Lu Zengqiang Zhang Hongxiang Yao Tong Han Chunshui Yu Bo Zhou Ying Han Xi Zhang Pindong Chen Yong Liu 《Neuroscience Bulletin》 2025年第9期1689-1695,共7页
Dear Editor,Growing clinical evidence shows that brain disorders are heterogeneous in phenotype,genetics,and neuropathology[1].Diagnosis and treatment tend to be affected by symptom presentation and the heterogeneity ... Dear Editor,Growing clinical evidence shows that brain disorders are heterogeneous in phenotype,genetics,and neuropathology[1].Diagnosis and treatment tend to be affected by symptom presentation and the heterogeneity of pathology,potentially hindering clinical trials in the development of medical treatment.Brain-based subtyping studies utilize magnetic resonance imaging(MRI)and data-driven methods to discover the subtypes of diseases,providing a new perspective on disease heterogeneity. 展开更多
关键词 magnetic resonance imaging brain disorders magnetic resonance imaging mri clinical trials subtyping methodologies disease heterogeneity cross sectional data
原文传递
Low-transition rates in human immunodeficiency virus-infected adolescents:A cross-sectional mixed study of pediatric to adult care transition in Uganda
6
作者 Agnes Batangira Emmanuel Otieno +1 位作者 Arthur Kiconco Bukiriro Robert Basaza 《World Journal of Clinical Pediatrics》 2025年第4期196-209,共14页
BACKGROUND Transition is a critical period for adolescents as they begin to assume responsibility for their own health.Similarly,the shift from pediatric to adult healthcare represents a vulnerable phase,marked by uni... BACKGROUND Transition is a critical period for adolescents as they begin to assume responsibility for their own health.Similarly,the shift from pediatric to adult healthcare represents a vulnerable phase,marked by unique challenges in adolescent health care.Despite its importance,only a few studies have explored healthcare transition among adolescents in Uganda.AIM To identify factors associated with the transition to adult human immunodeficiency virus(HIV)-centered care among adolescents attending HIV/AIDS clinics in Uganda.METHODS A cross-sectional mixed-methods study was conducted among 265 adolescents,randomly selected from three antiretroviral therapy(ART)clinics,using a structured questionnaire.Focus group discussions and key informant interviews were conducted.Individuals aged 10-20 years who were actively enrolled in the ART program between January 4,2022 and January 30,2023 were recruited.The primary outcome of interest was the transition to adult care.Bivariate and multivariate analyses were performed for quantitative data,while content analysis was used to analyze qualitative data.RESULTS The prevalence of transition to adult care was 40.6%.Most participants were male(53.6%)and fell within the 13-15 age group(35.6%).Multivariate logistic regression analysis identified several factors significantly associated with transition to adult care:Age group 10-12 years[prevalence ratio(PR)=2.525,95%CI:2.121-2.944,P=0.002],Age group 13-15 years(PR=1.900,95%CI:1.196-3.416,P=0.001),successful viral load suppression(PR=1.534,95%CI:1.173-1.648,P=0.016),disclosure of HIV status to relatives(PR=5.001,95%CI:3.411-3.611,P=0.000),being prepared for transitioning(PR=5.417,95%CI:3.468-7.135,P=0.041)and having skilled pediatric caregivers(PR=3.724,95%CI:2.084-4.105,P=0.005).CONCLUSION Transition to adult care among adolescents was low.Improving transition outcomes may require strengthening individual support within the family context and integrating transition-focused care into existing specialized clinical settings to enhance the delivery of adolescent-friendly services. 展开更多
关键词 Human immunodeficiency virus-infected adolescents Pediatric to adult care transition cross section study Human immunodeficiency virus epidemiology Multidisciplinary team Uganda
暂未订购
Analysis of Factors Influencing Insomnia and Construction of a Prediction Model:A Cross-sectional Survey on Rescuers 被引量:3
7
作者 SAI Xiao Yong CHEN Qiao +3 位作者 LUO Ting Gang SUN Yuan Yuan SONG Yu Jian CHEN Juan 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2020年第7期502-509,共8页
Objective To determine the factors influencing insomnia and construct early insomnia warning tools for rescuers to informbest practices for early screening and intervention.Methods Cluster sampling was used to conduct... Objective To determine the factors influencing insomnia and construct early insomnia warning tools for rescuers to informbest practices for early screening and intervention.Methods Cluster sampling was used to conduct a cross-sectional survey of 1,133 rescuers from one unit in Beijing,China.Logistic regression modeling and R software were used to analyze insomniarelated factors and construct a PRISM model,respectively.Results The positive rate of insomnia among rescuers was 2.74%.Accounting for participants’age,education,systolic pressure,smoking,per capita family monthly income,psychological resilience,and cognitive emotion regulation,logistic regression analysis revealed that,compared with families with an average monthly income less than 3,000 yuan,the odds ratio(OR)values and the[95%confidence interval(CI)]for participants of the following categories were as follows:average monthly family income greater than 5,000 yuan:2.998(1.307–6.879),smoking:4.124(1.954–8.706),and psychological resilience:0.960(0.933–0.988).The ROC curve area of the PRISM model(AUC)=0.7650,specificity=0.7169,and sensitivity=0.7419.Conclusion Insomnia was related to the participants’per capita family monthly income,smoking habits,and psychological resilience on rescue workers.The PRISM model’s good diagnostic value advises its use to screen rescuer early sleep quality.Further,advisable interventions to optimize sleep quality and battle effectiveness include psychological resilience training and smoking cessation. 展开更多
关键词 Rescuers INSOMNIA Influencing factors cross sectional survey Prediction model
暂未订购
Channel Measurement and Analysis of Human Body Radar Cross Section in26 GHz ISAC Systems 被引量:1
8
作者 DUAN Hongyu WANG Mengyang +4 位作者 DUO Hao HE Danping MA Yihua LU Bin ZHONG Zhangdui 《ZTE Communications》 2025年第2期3-10,共8页
Radar cross section(RCS)plays a critical role in modeling target scattering characteristics and enhancing the precision of target detection and localization in integrated sensing and communication(ISAC)systems.This pa... Radar cross section(RCS)plays a critical role in modeling target scattering characteristics and enhancing the precision of target detection and localization in integrated sensing and communication(ISAC)systems.This paper investigates the human body RCS at 26 GHz via multiangle channel measurements under different clothing conditions.Based on calibrated electromagnetic(EM)parameters,the RCS characteristics of the human body in far-field conditions are analyzed using ray-tracing(RT)simulations.Some suggestions for the design of ISAC systems are also discussed.The results provide a solid theoretical foundation and practical reference for the modeling of target scattering characteristics for ISAC channels. 展开更多
关键词 channel measurement human body radar cross section integrated sensing and communication RAY-TRACING
在线阅读 下载PDF
A substitution measurement for cross section of ^(65)Cu(γ,n)^(64)Cu reaction using ^(nat)Cu and ^(63)Cu targets by quasi-monoenergetic γ beams at SLEGS
9
作者 Pu Jiao Zi-Rui Hao +18 位作者 Zhi-Cai Li Qian-Kun Sun Long-Xiang Liu Hang-Hua Xu Yue Zhang Meng-Die Zhou Wen Luo Yu-Xuan Yang Sheng Jin Kai-Jie Chen Shan Ye Zhen-Wei Wang Yu-Ting Wang Hui-Ling Wei Yao Fu Kun Yu Hong-Wei Wang Gong-Tao Fan Chun-Wang Ma 《Nuclear Science and Techniques》 2025年第12期294-303,共10页
To overcome the difficulty and high cost of some specific isotopic targets,a substitution method was proposed to measure the cross section of the(γ,n)reactions.Considering that the natural copper element(^(nat)Cu)onl... To overcome the difficulty and high cost of some specific isotopic targets,a substitution method was proposed to measure the cross section of the(γ,n)reactions.Considering that the natural copper element(^(nat)Cu)only has^(63)Cu and^(65)Cu isotopes,the^(65)Cu(γ,n)^(64)Cu reaction was taken as an example to test the substitution method.Using quasi-monoenergeticγbeams provided by the Shanghai Laser Electron Gamma Source(SLEGS)of the Shanghai Synchrotron Radiation Facility(SSRF),^(nat)Cu(γ,n)was measured from E_(γ)=11.09 MeV to 17.87 MeV.Furthermore,based on the^(63)Cu(γ,n)reaction measured using the same experimental setup at SLEGS,^(65)Cu(γ,n)^(64)Cu was extracted using the substitution method.The abundance variation of natural copper,showing a significant influence on the cross section,was also investigated.The results were compared to the existing experimental data measured by bremsstrahlung and positron annihilation in-flight sources,and the TALYS 2.0 predictions.Theγstrength function(γSF)of^(65)Cu was obtained from the^(65)Cu(γ,n)data,and the reaction cross section of^(64)Cu(n,γ)was further calculated. 展开更多
关键词 Photoneutron cross section Flat-efficiency detector Laser Compton scattering γrays SLEGS Substitution measurement Copper isotopes
在线阅读 下载PDF
New measurement of ^(165)Ho neutron capture cross sections
10
作者 Su-Ya-La-Tu Zhang Yong-Shun Huang +7 位作者 Wei Jiang Jie Ren Rui-Rui Fan De-Xin Wang Chun-Lei Zhang Guo Li Dan-Dan Niu Mei-Rong Huang 《Nuclear Science and Techniques》 2025年第9期1-8,共8页
The neutron capture cross section for^(165)Ho was measured at the backstreaming white neutron beam line(Back-n)of the China Spallation Neutron Source(CSNS)using total energy detection systems,composed of a set of four... The neutron capture cross section for^(165)Ho was measured at the backstreaming white neutron beam line(Back-n)of the China Spallation Neutron Source(CSNS)using total energy detection systems,composed of a set of four C_(6)D_(6)scintillator detectors coupled with pulse height weighting techniques.The resonance parameters were extracted using the multilevel multichannel R-matrix code SAMMY to fit the measured capture yields of the^(165)Ho(n,γ)reaction in the neutron energy range below100 eV.Subsequently,the resonance region’s capture cross sections were reconstructed based on the obtained parameters.Furthermore,the unresolved resonance average cross section of the^(165)Ho(n,γ)reaction was determined relative to that of the standard sample^(197)Au within the neutron energy range of 2 keV to 1 MeV.The experimental data were compared with the recommended nuclear data from the ENDF/B-VIII.0 library,as well as with results of calculations performed using the TALYS-1.9 code.The comparison revealed agreement between the measured^(165)Ho(n,γ)cross sections and these data.The present results are crucial for evaluating the^(165)Ho neutron capture cross section and thus enhance the quality of evaluated nuclear data libraries.They provide valuable guidance for nuclear theoretical models and nuclear astrophysical studies. 展开更多
关键词 HOLMIUM Neutron capture reaction cross section Total energy detection principle C6D6 scintillator detector China Spallation Neutron Source
在线阅读 下载PDF
Spin-Orbit State-Resolved Differential Cross Sections of S(^(1)D)+HD Reaction
11
作者 Yu Li Heilong Wang +3 位作者 Zhirun Jiao Hongtao Zhang Chunlei Xiao Xueming Yang 《Chinese Journal of Chemical Physics》 2025年第5期582-586,I0147,共6页
Here,we report the spin-orbit state-resolved differential cross sections(DCSs)for the prototype barrierless reaction S(^(1)D)+HD.Both product channels,namely H+SD(^(2)Π_(3/2,1/2))and D+SH(^(2)Π_(3/2,1/2)),were measu... Here,we report the spin-orbit state-resolved differential cross sections(DCSs)for the prototype barrierless reaction S(^(1)D)+HD.Both product channels,namely H+SD(^(2)Π_(3/2,1/2))and D+SH(^(2)Π_(3/2,1/2)),were measured by high-resolution crossed molecular beam experiments.The DCSs of the two product channels show an overall forward-backward symmetry,in accordance with statistical model predictions.However,the DCSs for different spin-orbit manifolds show different preferences in forward or backward scattering directions at the same collision energies.This study reveals that,even though the title reaction proceeds via the long-lived complex mechanism,the spin-orbit coupling effects in the product channels play an important role in the reaction process. 展开更多
关键词 Barrierless reaction Spin-orbit effects crossed molecular beam Differential cross sections
在线阅读 下载PDF
Absolute Cross Sections for Direct and Dissociative Ionizations of Oxygen Molecule Measured by 350-8000 eV Electron Impact
12
作者 Weizhe Huang Taj Wali Khan +3 位作者 Yuting Zhang Enliang Wang Xu Shan Xiangjun Chen 《Chinese Journal of Chemical Physics》 2025年第2期164-171,I0039,共9页
The direct and dissociative ionizations of oxygen molecule are investigated experimen-tally by electron collision with energies from 350 eV to 8000 eV.The absolute ionization cross sections for the product ions(O_(2)^... The direct and dissociative ionizations of oxygen molecule are investigated experimen-tally by electron collision with energies from 350 eV to 8000 eV.The absolute ionization cross sections for the product ions(O_(2)^(2+),O_(2)^(2+)O^(+),O^(2+),and their total)and two Coulomb explosion channels(O^(+)+O^(+)and O^(2+)+O^(+))are obtained by putting the data of O^(2+)on the scale of Ar+from O_(2)and Ar gases mixed with a fixed relative flow ratio of 1:1.The experimental errors are assessed by taking uncertainties of various factors into account.The present absolute cross sections are well consistent with the previous data in the overlapped energy range below 1000 eV. 展开更多
关键词 Electron collision Absolute ionization cross section Oxygen molecule
在线阅读 下载PDF
Investigations of inelastic cross sections of H_(2)O molecule by He^(2+) and C^(6+) projectiles with energy range around the Bragg peak
13
作者 Guo-Zhuang Li Cheng-Ye Sun +5 位作者 Rui Cheng Yan-Shi Zhang Liang-Wen Chen Sheng Zhang Xin-Xia Li Lei Yang 《Nuclear Science and Techniques》 2025年第2期141-154,共14页
Inelastic collisions are the dominant cause of energy loss in radiotherapy.In the energy range around the Bragg peak,single ionization(SI)and single-electron capture(SC)are the primary inelastic collisions that lead t... Inelastic collisions are the dominant cause of energy loss in radiotherapy.In the energy range around the Bragg peak,single ionization(SI)and single-electron capture(SC)are the primary inelastic collisions that lead to energy loss.This study employs the classical trajectory Monte Carlo method to study the SI and SC processes of H_(2)O molecules using He^(2+) and C^(6+) projectiles in the energy range of 10 keV/u to 10 MeV/u.The total cross sections,single differential cross sections,impact parameter dependence of SI and SC,and fragmentation cross sections were investigated.Results illustrate that the cross section for SI is the highest when the projectile energy is close to the Bragg peak energy.When the projectile energy is below the Bragg peak energy,the ionized electrons in the forward direction dominate,and the removal of electrons can be associated with large impact parameters.As the projectile energy increases,the emission angle of the electrons gradually transitions from small angles(60°~120°)to large angles(60°~120°),and the removal of electrons is associated with small impact parameters.The energy distributions of the ionized electron are similar when the projectile energy is equal to,below or above the Bragg peak energy.The fragmentation cross sections after SI and SC in the energy range around the Bragg peak were also estimated. 展开更多
关键词 Classical trajectory Monte Carlo Heavy ion-water molecule collision Inelastic cross sections
在线阅读 下载PDF
Measurement of^(232)Th(p,x)^(225)Ac reaction cross section at CSNS APEP facility up to 80 MeV
14
作者 Bing Jiang Bin-Bin Tian +2 位作者 Han-Tao Jing Qi-Fan Dong Lu Guo 《Nuclear Science and Techniques》 2025年第3期167-177,共11页
The radioisotope actinium-225(^(225)Ac)has been successfully used for targeted alpha therapy in preclinical and clinical applications because of its excellent nuclear characteristics.Medium-and high-energy proton-spal... The radioisotope actinium-225(^(225)Ac)has been successfully used for targeted alpha therapy in preclinical and clinical applications because of its excellent nuclear characteristics.Medium-and high-energy proton-spallation reactions on thorium are the most important methods for producing^(225)Ac.This study examines the possibility of producing^(225)Ac by irradiating thorium oxide with medium-energy protons.Thorium-oxide sheets were irradiated with 40-,50-,60-,70-,and 80-Me V protons on the Associated Proton-beam Experiment Platform(APEP)of the China Spallation Neutron Source(CSNS).The cross sections for the formation of^(225)Ac were measured using the activation method and offline gamma-ray spectrometric technique.The experimental results were compared with the existing data from EXFOR as well as the theoretical data from the TALYS-based evaluated nuclear-data library.Based on the experimental cross section and theoretical calculations,the production yield of^(225)Ac in the irradiated thorium targets was examined.The results showed that APEP can produce sufficient quantities of^(225)Ac for purification and clinical therapy.This work is the first measurement of proton-induced nuclearreaction cross sections at the CSNS APEP. 展开更多
关键词 ^(232)Th target Proton irradiation ^(225)Ac producing cross section
在线阅读 下载PDF
The quadratic B-spline curve fitting for the shape of log cross sections 被引量:2
15
作者 任洪娥 吴妍 朱哓明 《Journal of Forestry Research》 SCIE CAS CSCD 2006年第2期150-152,共3页
This paper describes a new method for simulation of the cross section shape of log. The self-developed MQK3102 log shape recognizing machine was used to acquire the finite discrete sampling points on the cross section... This paper describes a new method for simulation of the cross section shape of log. The self-developed MQK3102 log shape recognizing machine was used to acquire the finite discrete sampling points on the cross section of log and those points were fitted with the quadratic B-spline parametric curve. This method can clearly stimulate the real shape of the log cross section and is characterized by limited sampling points and high speed computing. The computed result of the previous curve does not affect the next one, which may avoid the graphic distortion caused by the accumulative error. The method can be used to simulate the whole body shape of log approximately by sampling the cross sections along the length direction of log, thus providing a reference model for optimum saw cutting of log. 展开更多
关键词 Quadratic B-spline curve cross section shape LOG Computer simulation Optimum saw cutting
在线阅读 下载PDF
Electrospinning of FeNiCo/carbon nanofibers:a new paradigm for lightweight microwave absorbers
16
作者 Yuan Wenpei Qu Lin +3 位作者 Wang Yajing Liu Pengyu Zhang Yanlan Wang Yongzhen 《新型炭材料(中英文)》 北大核心 2026年第1期234-252,共19页
With the rapid development of modern electronic technology,the demand for high-performance microwave absorption materials has increased dramatically.In order to meet this demand,the electrospinning of FeNiCo/carbon na... With the rapid development of modern electronic technology,the demand for high-performance microwave absorption materials has increased dramatically.In order to meet this demand,the electrospinning of FeNiCo/carbon nanofiber(FeNiCo/CNF)composites with excellent microwave absorption properties was developed,and their potential as high frequency microwave absorption materials was evaluated.Experiment showed that FeNiCo/CNFs achieve a minimum reflection loss(RL_(min))of−55.5 dB with a matching thickness of only 1.6 mm.Microstructure analysis and electromagnetic parameter testing showed that the excellent microwave absorbing properties were mainly due to the combined effect of the network structure of carbon nanofibers and the FeNiCo alloy.This interaction promotes multiple reflections and the efficient absorption of microwaves.Computer simulation also showed that the FeNiCo/CNF composites produce an excellent radar cross-section reduction in typical radar operating frequency bands,which validates their potential application in stealth technology.This is a new concept in the development of high-performance microwave absorption materials. 展开更多
关键词 ELECTROSPINNING ALLOY Composite nanofibers Radar cross section Microwave absorption
在线阅读 下载PDF
Linear relationship between reactivity and the reciprocal of uranium concentration in thermal-spectrum molten salt re
17
作者 Chang-Qing Yu Gui-Feng Zhu +7 位作者 Shu-Yang Jia Yang Zou Rui Yan Jian Guo Ya-Fen Liu Bo Zhou Xue-Chao Zhao Xiao-Han Yu 《Nuclear Science and Techniques》 2026年第2期208-222,共15页
Knowing the precise relationship between fuel loading and reactivity is essential for guiding reactor criticality extrapolation and online refueling in molten salt reactors(MSRs).This study aims to explore and explain... Knowing the precise relationship between fuel loading and reactivity is essential for guiding reactor criticality extrapolation and online refueling in molten salt reactors(MSRs).This study aims to explore and explain the linear relationship between reactivity and the reciprocal of uranium concentration in thermal-spectrum MSRs.By applying neutron balance theory,we analyzed the neutron absorption cross sections of various nuclides in single-lattice models with varying fuel concentrations.Our findings reveal a simple linear correlation between reactivity and the reciprocal of uranium concentration,which can be explained from the perspective of nuclear reaction cross sections that adhere to the 1/v law in the thermal neutron spectrum.Furthermore,we identified that the neutron absorption single-group cross sections of structural materials and carrier salts exhibit an approximately linear relationship with the fission single-group cross section of ^(235) U;similarly,the reciprocal of ^(235)U’s fission cross section exhibits an approximately linear relationship with uranium concentration.This linear relationship deviates as the volume fraction of molten salt increases,due to a greater proportion of neutrons being captured in the resonance energy spectrum.However,it remains valid for molten salt volume fractions up to 25%and demonstrates broad applicability in the physical design and operation of thermal molten salt reactors. 展开更多
关键词 Molten salt reactor REACTIVITY Uranium concentration cross sections LINEAR
在线阅读 下载PDF
Investigation of the production of ^(152)Tb and ^(155)Tb terbium radioisotopes with europium targets
18
作者 C.Yalçın 《Nuclear Science and Techniques》 2026年第2期183-193,共11页
In recent years,terbium radioisotopes have been investigated for their potential therapeutic and diagnostic applications in nuclear medicine.This study aimed to investigate the production of ^(152) Tb and ^(155) Tb by... In recent years,terbium radioisotopes have been investigated for their potential therapeutic and diagnostic applications in nuclear medicine.This study aimed to investigate the production of ^(152) Tb and ^(155) Tb by alpha-induced reactions in detail,with a specific focus on determining the optimum production parameters and testing existing nuclear models.Given the limited number of experiments conducted on reactions related to terbium isotope production,it is necessary to perform theoretical calculations of cross sections over a wide energy range to gain a detailed understanding of terbium isotope production.To achieve this objective,the cross sections of the ^(151)Eu(α,n)^(154) Tb reactions were calculated up to 60 MeV using the TALYS computer code with 432 different combinations of optical model parameters,level density,and strength function models.The theoretical reaction cross-section results were compared with the experimental results in the literature.The best input parameters were determined using the Threshold Logic Unit method,and these parameters were used in all isotope production calculations.Once the optimal model combination was determined,the total activity production and isotopic fraction of ^(152) Tb and ^(155) Tb isotopes were calculated in detail for beam energies of 17–50 MeV,different irradiation times,and varying ^(151) Eu and ^(153) Eu target thicknesses. 展开更多
关键词 Terbium radioisotopes Medical isotope production Alpha-induced reactions cross section Threshold logic unit method
暂未订购
Generalized reduced R-matrix theoretical analysis of the^(5)He system
19
作者 Xu Han Tao Ye +4 位作者 Zhen-Peng Chen Hai-Rui Guo Wei-Li Sun Zhi-Hao Sun Hao-Yang Fan 《Nuclear Science and Techniques》 2026年第4期188-201,共14页
Based on the generalized reduced R-matrix theory,the R-matrix analysis code(RAC program)was used to analyze the experimental data of all the nuclear reaction channels related to the 5 He system.The current calculation... Based on the generalized reduced R-matrix theory,the R-matrix analysis code(RAC program)was used to analyze the experimental data of all the nuclear reaction channels related to the 5 He system.The current calculations provide accurate and reliable evaluation data and are in good agreement with the experimental data.In this study,self-consistent evaluation data for each reaction were obtained using multi-channel and multi-energy fitting.In particular,the error propagation theory of generalized least squares was used to determine the error of the evaluation data and the covariance matrix of the integral cross section.This R-matrix analysis for the 5 He system has three features.First,for the first time,the error in the evaluation data of the T(d,n)^(4)He reaction cross section and the covariance matrix of the integral cross section are provided.Second,we used only one set of R-matrix parameters to depict the reaction cross section of each reaction channel of the 5 He system for the entire energy region in our work.Third,in this evaluation,we considered some of the latest measured experimental data,especially after 2000.The T(d,n)^(4)He reaction cross section at 0.1 MeV and below was carefully studied.The effect of different energy levels in T(d,n)^(4)He was analyzed,with the energy levels 3/2^(+)making a major contribution to the cross section,and the role of the S-wave and P-wave from 3/2~-determines the lean forward trend of the angular distributions at 0.01–0.1 MeV. 展开更多
关键词 R-matrix theory Nuclear reaction cross section Evaluation of data Generalized least squares ^(5)He system
在线阅读 下载PDF
Production of proton-rich isotopes of Pu,Cm,Bk,Ds,Cn,Fl by fusion evaporation reactions with^(40)Ar projectile
20
作者 Qing-Qing Yao Tian-Liang Zhao Xiao-Jun Bao 《Nuclear Science and Techniques》 2026年第3期119-131,共13页
The evaporation residual cross sections(ERCSs)of these reactions were calculated by using^(144)Sm,^(160,164)Dy,^(165)Ho,^(166)Er,^(169)Tm,^(171,174)Yb,^(175)Lu,^(176-180)Hf,^(181)Ta,^(180,182)W and^(187)Re targets wit... The evaporation residual cross sections(ERCSs)of these reactions were calculated by using^(144)Sm,^(160,164)Dy,^(165)Ho,^(166)Er,^(169)Tm,^(171,174)Yb,^(175)Lu,^(176-180)Hf,^(181)Ta,^(180,182)W and^(187)Re targets with^(40)Ar projectiles in the theoretical framework of the dinuclear system(DNS)model.The de-excitation process of the compound nucleus was theoretically calculated using two different statistical models,namely the statistical model 1 and statistical model 2(GEMINI++model).The calculated ERCSs were also compared with the experimental data.The ERCSs of synthesizing new proton-rich nuclides were investigated based on the fusion evaporation reaction.Predictions were made for the ERCSs of new isotopes of Pu,Cm and Bk in the heavy nuclei region,while the new isotopes of Ds,Cn and Fl are predicted in the superheavy nuclei region of Z≥104. 展开更多
关键词 Dinuclear system model Evaporation residue cross section Proton-rich nuclides
在线阅读 下载PDF
上一页 1 2 32 下一页 到第
使用帮助 返回顶部