Dear Editor,Psoriasis,a chronic inflammatory cutaneous condition,is characterized by the development of red plaques with silvery scales,significantly affecting patients'quality of life and mental health[1].This co...Dear Editor,Psoriasis,a chronic inflammatory cutaneous condition,is characterized by the development of red plaques with silvery scales,significantly affecting patients'quality of life and mental health[1].This condition is thought to affect approximately 2%of the Western population,with diagnosis peaking in early adulthood[2].Vitamin D,a fat-soluble vitamin,is essential for phospho-calcium metabolism,calcium homeostasis,and bone health.展开更多
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
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
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
Accurate fission cross-sectional data for actinide nuclides are critical for nuclear energy,astrophysics,and defense applications.Traditional detectors,such as fission chambers,face limitations in achieving sub-3% unc...Accurate fission cross-sectional data for actinide nuclides are critical for nuclear energy,astrophysics,and defense applications.Traditional detectors,such as fission chambers,face limitations in achieving sub-3% uncertainty owing to particle identification challenges and dynamic range constraints.The time projection chamber(TPC)can record both the energy deposition dE/dx and the three-dimensional track of an event,providing the ability to identify particles and fission fragments.Based on this characteristic,we developed a novel TPC,INPC-TPC,featuring a symmetrical dual-chamber structure and gas electron multiplier(GEM)-based readout technology.The dual-chamber design isolates fission fragments and recoils protons,thereby reducing the dynamic range requirements of a single chamber,whereas the GEM ensures high spatial resolution and stable gain.Experiments conducted at the Chinese Spallation Neutron Source(CSNS)Back-n white neutron beamline validated the performance of the proposed detector.The INPC-TPC demonstrated effective fission fragment identification through particle energy-length correlation measurements and accurately measured the neutron beam spot size with a diameter relative error of<2%.The results highlight the capability of the system to achieve high-precision measurements of neutroninduced fission cross sections,particularly for ^(235)U and ^(238)U.展开更多
Wide-field mesoscopy provides the capabilities of cortex-wide field of view(FOV),cellular resolution and high frame rate for neuronal imaging in the mouse brain.However,inherent background fluorescence degrades the im...Wide-field mesoscopy provides the capabilities of cortex-wide field of view(FOV),cellular resolution and high frame rate for neuronal imaging in the mouse brain.However,inherent background fluorescence degrades the image quality and hinders neuronal signal extraction.To address this problem,we first introduce a cortex-wide,high-resolution lineillumination mesoscope with a moving slit designed for in vivo mouse brain imaging.This system achieves a 6.6×6.6 mm FOV,microscale cellular resolution,a high frame rate of 10 Hz,as well as the background rejection ability.Furthermore,we integrated patterned illumination into the system to enhance the background suppression.Experimental results show that the proposed system successfully captures neurodynamics in the living mouse brain.Compared with conventional wide-field mesoscopes,the cortex-wide patterned line-illumination mesoscope(PLIM)achieves a threefold increase in the signal-to-background ratio(SBR).With patterned illumination integrated,the SBR enhancement further reaches four-anda-half-fold.展开更多
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
在联合国《2030年可持续发展议程》及其17项可持续发展目标的背景下,践行可持续发展已成为公共机构的核心责任。其中,图书馆借助馆藏资源、主题展览、专项活动、共享服务以及种子图书馆、创客空间、修理咖啡馆等创新举措积极提升公众环...在联合国《2030年可持续发展议程》及其17项可持续发展目标的背景下,践行可持续发展已成为公共机构的核心责任。其中,图书馆借助馆藏资源、主题展览、专项活动、共享服务以及种子图书馆、创客空间、修理咖啡馆等创新举措积极提升公众环保意识,在推动可持续生活方式上发挥着至关重要的作用。为推动不同背景下的绿色图书馆规划、实施与评估,当地时间2026年1月27日,国际图联环境可持续性与图书馆专业组(ENSULIB Section)正式发布《国际图联绿色图书馆指南》(IFLA Guidelines for Green Libraries)。展开更多
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
Measuring cross sections of nuclear reactions,such as the so-called“Holy Grail”reaction,^(12)C(σ,γ)^(16)O,is essential for understanding stellar nucleosynthesis but presents significant challenges due to extremely...Measuring cross sections of nuclear reactions,such as the so-called“Holy Grail”reaction,^(12)C(σ,γ)^(16)O,is essential for understanding stellar nucleosynthesis but presents significant challenges due to extremely low cross sections.Key challenges include significant energy loss as ions penetrate the target material,limiting measurements to thin target layers.To overcome these obstacles,we propose a novel method,the in-target energy loss compensating(eLOC)method,specifically designed for gas targets,which utilizes a gas-filled magnetic field and accelerating electric fields to compensate for ion energy loss in the target.Simulations show that this approach significantly enhances the effective target thickness by over 140 times in the case of the“Holy Grail”reaction with an inverse-kinematics setup.This eLOC method may provide a powerful new tool for obtaining critical data in nuclear astrophysics,thereby advancing our understanding of stellar nucleosynthesis and the origins of elements in the universe,as well as benefiting other related fields such as isotope production.展开更多
Let M be a compact n-manifold of positive sectional curvature.We will review classical results on the fundamental group of M,a motivation on the c(n)-cyclic conjecture that the fundamental group of M contains a cyclic...Let M be a compact n-manifold of positive sectional curvature.We will review classical results on the fundamental group of M,a motivation on the c(n)-cyclic conjecture that the fundamental group of M contains a cyclic subgroup of index bounded above by c(n),a constant depending only on n,and we will survey partial results(up to date)on the c(n)-cyclic conjecture.展开更多
To uncover the decision-making mechanisms and evolutionary dynamics of multiple stakeholders in highway noise pollution control,a three-party evolutionary game model involving the government,operators,and the public i...To uncover the decision-making mechanisms and evolutionary dynamics of multiple stakeholders in highway noise pollution control,a three-party evolutionary game model involving the government,operators,and the public is constructed.The operation period is divided into different stages for differentiated analysis.A simulation analysis was performed on the Lituo sinking section of the Beijing-Hong Kong-Macao Highway to assess the impact of variations in critical elements on the system.The results indicate that the Lituo sinking section of the Beijing-Hong Kong-Macao Highway is currently in its early stage of development,with the corresponding strategies being active regulation,excessive emissions,and supervision.When the cost of the government’s active regulation decreases from 1×10^(5) to 5×10^(4) yuan,the system converges more rapidly toward the active regulation strategy.When the cost of the operator’s excessive emissions increases from 14.08×10^(6) to 20.00×10^(6) yuan,the system drives the operator toward the standardized emission strategy.In addition,when the cost of public supervision decreases from 15×10^(4) to 5×10^(4) yuan and the compensation paid by operators to the public increases from 1.288×10^(6) to 2.576×10^(6) yuan,the system converges more quickly toward the supervision strategy.The cost of the operator’s excessive emissions serves as the core decision variable for achieving the ideal equilibrium in the three-party game involving government active regulation,operator standardized emissions,and public supervision.展开更多
Generalised reduced masses with a set of equations governing the three relative motions between two of 3-bodies in their gravitational field are established,of which the dynamic characteristics of 3-body dynamics,fund...Generalised reduced masses with a set of equations governing the three relative motions between two of 3-bodies in their gravitational field are established,of which the dynamic characteristics of 3-body dynamics,fundamental bases of this paper,are revealed.Based on these findings,an equivalent system is developed,which is a 2-body system with its total mass,constant angular momentum,kinetic and potential energies same as the total ones of three relative motions,so that it can be solved using the well-known theory of the 2-body system.From the solution of an equivalent system with the revealed characteristics of three relative motions,the general theoretical solutions of the 3-body system are obtained in the curve-integration forms along the orbits in the imaged radial motion space.The possible periodical orbits with generalised Kepler’s law are presented.Following the description and mathematical demonstrations of the proposed methods,the examples including Euler’s/Lagrange’s problems,and a reported numerical one are solved to validate the proposed methods.The methods derived from the 3-body system are extended to N-body problems.展开更多
Climate model prediction has been improved by enhancing model resolution as well as the implementation of sophisticated physical parameterization and refinement of data assimilation systems[section 6.1 in Wang et al.(...Climate model prediction has been improved by enhancing model resolution as well as the implementation of sophisticated physical parameterization and refinement of data assimilation systems[section 6.1 in Wang et al.(2025)].In relation to seasonal forecasting and climate projection in the East Asian summer monsoon season,proper simulation of the seasonal migration of rain bands by models is a challenging and limiting factor[section 7.1 in Wang et al.(2025)].展开更多
The single electron capture processes in Si^(3,4+)+He collisions have been investigated theoretically employing the two-center atomic orbital close-coupling method in the energy range 0.01-100 keV/u.Total and state-se...The single electron capture processes in Si^(3,4+)+He collisions have been investigated theoretically employing the two-center atomic orbital close-coupling method in the energy range 0.01-100 keV/u.Total and state-selective electron capture cross sections for the dominant and subdominant reaction channels are calculated and compared with the available experimental and theoretical data.For the total charge transfer cross sections,the present results show better agreements with the available experimental data than the other theoretical ones in the overlapping energy region for both collision systems.For the state-selective cross sections,the present results for 3s and 3p states are in general agreement with the previous MOCC results in the low energy region for both collision systems.Furthermore,the cross sections for electron captured to the 3d,4l and 5l(l=0,1,...,n-1)states of Si^(2+)and Si^(3+)ions are first provided in a broad energy region in our work.These results are useful for the investigations in astrophysics.The datasets presented in this paper,including the total and state-selective electron capture cross sections of Si^(3,4+)+He collisions in 0.01-100 ke V/u,are openly available at https://doi.org/10.57760/sciencedb.j00113.00257.展开更多
In this paper,the Jiangxi section of the red army's long march is taken as the research object to construct a red cultural heritage corridor.Introducing the theory of heritage corridor,on the basis of its hierarch...In this paper,the Jiangxi section of the red army's long march is taken as the research object to construct a red cultural heritage corridor.Introducing the theory of heritage corridor,on the basis of its hierarchical decomposition and comparative judgment,a hierarchy model of the red cultural heritage corridor resource is established.The comprehensive scores of each factor are obtained through expert scoring,and the overall pattern of red army corridor is constructed as"ring-shape-point".New ideas for protection and utilization as well as protection implementation measures are proposed,and the spiritual and cultural connotations of long march in Jiangxi are fully explored.This could help the social and economic development of the areas along the long march of red army in Jiangxi,and promote the integrated utilization and coordinated development of resources in the red cultural heritage corridor region.展开更多
In this editorial,we comment on a recent article by Chen et al,that addressed the effect of intraoperative injection of esketamine on postoperative analgesia and postoperative rehabilitation after cesarean section.Poo...In this editorial,we comment on a recent article by Chen et al,that addressed the effect of intraoperative injection of esketamine on postoperative analgesia and postoperative rehabilitation after cesarean section.Poor management of postcesarean pain is associated with decreased maternal care for the baby,longer hospitalization,and higher risk of developing postpartum depression.Esketamine is a more potent S-enantiomer of ketamine which has shown promising analgesic and antidepressant properties for managing post-cesarean pain and depression in clinical studies.However,due to its potential adverse effects on the neurological and hemodynamic status of patients,it is recommended that its usage in low doses should be limited to cesarean candidates experiencing unbearable pain.Before any recommendation for routine perioperative use of esketamine,more standardized clinical trials are needed to strengthen our existing knowledge of its effectiveness in reducing postpartum pain and depression.展开更多
To overcome the limitations of low efficiency and reliance on manual processes in the measurement of geometric parameters for bridge prefabricated components,a method based on deep learning and computer vision is deve...To overcome the limitations of low efficiency and reliance on manual processes in the measurement of geometric parameters for bridge prefabricated components,a method based on deep learning and computer vision is developed to identify the geometric parameters.The study utilizes a common precast element for highway bridges as the research subject.First,edge feature points of the bridge component section are extracted from images of the precast component cross-sections by combining the Canny operator with mathematical morphology.Subsequently,a deep learning model is developed to identify the geometric parameters of the precast components using the extracted edge coordinates from the images as input and the predefined control parameters of the bridge section as output.A dataset is generated by varying the control parameters and noise levels for model training.Finally,field measurements are conducted to validate the accuracy of the developed method.The results indicate that the developed method effectively identifies the geometric parameters of bridge precast components,with an error rate maintained within 5%.展开更多
The integration of image analysis through deep learning(DL)into rock classification represents a significant leap forward in geological research.While traditional methods remain invaluable for their expertise and hist...The integration of image analysis through deep learning(DL)into rock classification represents a significant leap forward in geological research.While traditional methods remain invaluable for their expertise and historical context,DL offers a powerful complement by enhancing the speed,objectivity,and precision of the classification process.This research explores the significance of image data augmentation techniques in optimizing the performance of convolutional neural networks(CNNs)for geological image analysis,particularly in the classification of igneous,metamorphic,and sedimentary rock types from rock thin section(RTS)images.This study primarily focuses on classic image augmentation techniques and evaluates their impact on model accuracy and precision.Results demonstrate that augmentation techniques like Equalize significantly enhance the model's classification capabilities,achieving an F1-Score of 0.9869 for igneous rocks,0.9884 for metamorphic rocks,and 0.9929 for sedimentary rocks,representing improvements compared to the baseline original results.Moreover,the weighted average F1-Score across all classes and techniques is 0.9886,indicating an enhancement.Conversely,methods like Distort lead to decreased accuracy and F1-Score,with an F1-Score of 0.949 for igneous rocks,0.954 for metamorphic rocks,and 0.9416 for sedimentary rocks,exacerbating the performance compared to the baseline.The study underscores the practicality of image data augmentation in geological image classification and advocates for the adoption of DL methods in this domain for automation and improved results.The findings of this study can benefit various fields,including remote sensing,mineral exploration,and environmental monitoring,by enhancing the accuracy of geological image analysis both for scientific research and industrial applications.展开更多
There is an urgent need for the application of broadband Microwave Absorption(MA)structures on the leading edges of aircraft wings,which requires the MA structures to possess both the broadband MA performance and grea...There is an urgent need for the application of broadband Microwave Absorption(MA)structures on the leading edges of aircraft wings,which requires the MA structures to possess both the broadband MA performance and great surface conformability.To meet these requirements,we designed and fabricated a flexible bioinspired meta-structure with ultra-broadband MA,thin thickness and excellent surface conformality.The carbonyl iron powder-carbon nanotubes-polydimethylsiloxane composite was synthesized by physical blending method for fabricating the MA meta-structure.Through geometry-electromagnetic optimal design by heuristic optimization algorithm,the meta-structure mimicking to the nipple photonic nanostructures on the eyes of moth can achieve ultra-broadband MA performance of 35.14 GHz MA bandwidth(reflection loss≤–10 dB),covering 4.86–40.00 GHz,with thickness of only 4.3 mm.Through simple fabrication processes,the meta-structure has been successfully fabricated and bonded on wings’leading edges,exhibiting excellent surface conformability.Furthermore,the designed flexible MA meta-structure possesses significant Radar Cross-Section(RCS)reduction capability,as demonstrated by the RCS analysis of an unmanned aerial vehicle.This flexible ultra-broadband MA meta-structure provides an outstanding candidate to meet the radar stealth requirement of variable curvature structures on aircraft.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.82573974 and 82373475)to Z.Y.
文摘Dear Editor,Psoriasis,a chronic inflammatory cutaneous condition,is characterized by the development of red plaques with silvery scales,significantly affecting patients'quality of life and mental health[1].This condition is thought to affect approximately 2%of the Western population,with diagnosis peaking in early adulthood[2].Vitamin D,a fat-soluble vitamin,is essential for phospho-calcium metabolism,calcium homeostasis,and bone health.
基金supported by the Natural Science Foundation of Shanxi Province(202203021212205)Shanxi Province Major Science and Technology Special Project‘Jiebang Guashuai’Project(202101120401008)+1 种基金National Natural Science Foundation of China(52371231)Key R&D Program of Shanxi Province(202302040201008).
文摘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.
基金supported by the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2020261)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA02010000)the Young Potential Program of the Shanghai Institute of Applied Physics,Chinese Academy of Sciences(No.SINAP-YXJH-202412)。
文摘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.
文摘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.
基金supported by the auspices of the Youth Doctoral Talent Incubation Program of the Second Affiliated Hospital of Army Medical University(No.2024YQB060)。
文摘Accurate fission cross-sectional data for actinide nuclides are critical for nuclear energy,astrophysics,and defense applications.Traditional detectors,such as fission chambers,face limitations in achieving sub-3% uncertainty owing to particle identification challenges and dynamic range constraints.The time projection chamber(TPC)can record both the energy deposition dE/dx and the three-dimensional track of an event,providing the ability to identify particles and fission fragments.Based on this characteristic,we developed a novel TPC,INPC-TPC,featuring a symmetrical dual-chamber structure and gas electron multiplier(GEM)-based readout technology.The dual-chamber design isolates fission fragments and recoils protons,thereby reducing the dynamic range requirements of a single chamber,whereas the GEM ensures high spatial resolution and stable gain.Experiments conducted at the Chinese Spallation Neutron Source(CSNS)Back-n white neutron beamline validated the performance of the proposed detector.The INPC-TPC demonstrated effective fission fragment identification through particle energy-length correlation measurements and accurately measured the neutron beam spot size with a diameter relative error of<2%.The results highlight the capability of the system to achieve high-precision measurements of neutroninduced fission cross sections,particularly for ^(235)U and ^(238)U.
基金support from the National Natural Science Foundation of China(Grant No.61971256)。
文摘Wide-field mesoscopy provides the capabilities of cortex-wide field of view(FOV),cellular resolution and high frame rate for neuronal imaging in the mouse brain.However,inherent background fluorescence degrades the image quality and hinders neuronal signal extraction.To address this problem,we first introduce a cortex-wide,high-resolution lineillumination mesoscope with a moving slit designed for in vivo mouse brain imaging.This system achieves a 6.6×6.6 mm FOV,microscale cellular resolution,a high frame rate of 10 Hz,as well as the background rejection ability.Furthermore,we integrated patterned illumination into the system to enhance the background suppression.Experimental results show that the proposed system successfully captures neurodynamics in the living mouse brain.Compared with conventional wide-field mesoscopes,the cortex-wide patterned line-illumination mesoscope(PLIM)achieves a threefold increase in the signal-to-background ratio(SBR).With patterned illumination integrated,the SBR enhancement further reaches four-anda-half-fold.
基金supported by Science Challenge Project(No.TZ20180001)。
文摘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.
文摘在联合国《2030年可持续发展议程》及其17项可持续发展目标的背景下,践行可持续发展已成为公共机构的核心责任。其中,图书馆借助馆藏资源、主题展览、专项活动、共享服务以及种子图书馆、创客空间、修理咖啡馆等创新举措积极提升公众环保意识,在推动可持续生活方式上发挥着至关重要的作用。为推动不同背景下的绿色图书馆规划、实施与评估,当地时间2026年1月27日,国际图联环境可持续性与图书馆专业组(ENSULIB Section)正式发布《国际图联绿色图书馆指南》(IFLA Guidelines for Green Libraries)。
基金supported by the National Natural Science Foundation of China(Nos.12175064 and U2167203)Hunan Outstanding Youth Science Foundation(No.2022JJ10031)。
文摘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.
基金supported by the the National Key R&D Program of China (Grant Nos.2023YFA1606900 and 2022YFA1602301)the National Natural Science Foundation of China (Grant Nos.12235003,12435010,and 12147101)+3 种基金the Guangdong Major Project of Basic and Applied Basic Research (Grant No.2020B0301030008)the STCSM (Grant No.23590780100)the Natural Science Foundation of Shanghai (Grant No.23JC1400200)the China Postdoctoral Science Foundation (Grant No.2024M760483)。
文摘Measuring cross sections of nuclear reactions,such as the so-called“Holy Grail”reaction,^(12)C(σ,γ)^(16)O,is essential for understanding stellar nucleosynthesis but presents significant challenges due to extremely low cross sections.Key challenges include significant energy loss as ions penetrate the target material,limiting measurements to thin target layers.To overcome these obstacles,we propose a novel method,the in-target energy loss compensating(eLOC)method,specifically designed for gas targets,which utilizes a gas-filled magnetic field and accelerating electric fields to compensate for ion energy loss in the target.Simulations show that this approach significantly enhances the effective target thickness by over 140 times in the case of the“Holy Grail”reaction with an inverse-kinematics setup.This eLOC method may provide a powerful new tool for obtaining critical data in nuclear astrophysics,thereby advancing our understanding of stellar nucleosynthesis and the origins of elements in the universe,as well as benefiting other related fields such as isotope production.
文摘Let M be a compact n-manifold of positive sectional curvature.We will review classical results on the fundamental group of M,a motivation on the c(n)-cyclic conjecture that the fundamental group of M contains a cyclic subgroup of index bounded above by c(n),a constant depending only on n,and we will survey partial results(up to date)on the c(n)-cyclic conjecture.
基金The Natural Science Foundation of Heilongjiang Province(No.LH2023E011)Open Fund of National Key Laboratory of Green and Long-Life Road Engineering in Extreme Environment in Changsha University of Science and Technology(No.kfj230105).
文摘To uncover the decision-making mechanisms and evolutionary dynamics of multiple stakeholders in highway noise pollution control,a three-party evolutionary game model involving the government,operators,and the public is constructed.The operation period is divided into different stages for differentiated analysis.A simulation analysis was performed on the Lituo sinking section of the Beijing-Hong Kong-Macao Highway to assess the impact of variations in critical elements on the system.The results indicate that the Lituo sinking section of the Beijing-Hong Kong-Macao Highway is currently in its early stage of development,with the corresponding strategies being active regulation,excessive emissions,and supervision.When the cost of the government’s active regulation decreases from 1×10^(5) to 5×10^(4) yuan,the system converges more rapidly toward the active regulation strategy.When the cost of the operator’s excessive emissions increases from 14.08×10^(6) to 20.00×10^(6) yuan,the system drives the operator toward the standardized emission strategy.In addition,when the cost of public supervision decreases from 15×10^(4) to 5×10^(4) yuan and the compensation paid by operators to the public increases from 1.288×10^(6) to 2.576×10^(6) yuan,the system converges more quickly toward the supervision strategy.The cost of the operator’s excessive emissions serves as the core decision variable for achieving the ideal equilibrium in the three-party game involving government active regulation,operator standardized emissions,and public supervision.
文摘Generalised reduced masses with a set of equations governing the three relative motions between two of 3-bodies in their gravitational field are established,of which the dynamic characteristics of 3-body dynamics,fundamental bases of this paper,are revealed.Based on these findings,an equivalent system is developed,which is a 2-body system with its total mass,constant angular momentum,kinetic and potential energies same as the total ones of three relative motions,so that it can be solved using the well-known theory of the 2-body system.From the solution of an equivalent system with the revealed characteristics of three relative motions,the general theoretical solutions of the 3-body system are obtained in the curve-integration forms along the orbits in the imaged radial motion space.The possible periodical orbits with generalised Kepler’s law are presented.Following the description and mathematical demonstrations of the proposed methods,the examples including Euler’s/Lagrange’s problems,and a reported numerical one are solved to validate the proposed methods.The methods derived from the 3-body system are extended to N-body problems.
文摘Climate model prediction has been improved by enhancing model resolution as well as the implementation of sophisticated physical parameterization and refinement of data assimilation systems[section 6.1 in Wang et al.(2025)].In relation to seasonal forecasting and climate projection in the East Asian summer monsoon season,proper simulation of the seasonal migration of rain bands by models is a challenging and limiting factor[section 7.1 in Wang et al.(2025)].
基金supported by the National Key Research and Development Program of China(Grant No.2022YFA1602504)the National Natural Science Foundation of China(Grant Nos.12274040 and U2430208)。
文摘The single electron capture processes in Si^(3,4+)+He collisions have been investigated theoretically employing the two-center atomic orbital close-coupling method in the energy range 0.01-100 keV/u.Total and state-selective electron capture cross sections for the dominant and subdominant reaction channels are calculated and compared with the available experimental and theoretical data.For the total charge transfer cross sections,the present results show better agreements with the available experimental data than the other theoretical ones in the overlapping energy region for both collision systems.For the state-selective cross sections,the present results for 3s and 3p states are in general agreement with the previous MOCC results in the low energy region for both collision systems.Furthermore,the cross sections for electron captured to the 3d,4l and 5l(l=0,1,...,n-1)states of Si^(2+)and Si^(3+)ions are first provided in a broad energy region in our work.These results are useful for the investigations in astrophysics.The datasets presented in this paper,including the total and state-selective electron capture cross sections of Si^(3,4+)+He collisions in 0.01-100 ke V/u,are openly available at https://doi.org/10.57760/sciencedb.j00113.00257.
基金Supported by the Humanities and Social Science Research Project of Jiangxi Provincial Universities(YS23104).
文摘In this paper,the Jiangxi section of the red army's long march is taken as the research object to construct a red cultural heritage corridor.Introducing the theory of heritage corridor,on the basis of its hierarchical decomposition and comparative judgment,a hierarchy model of the red cultural heritage corridor resource is established.The comprehensive scores of each factor are obtained through expert scoring,and the overall pattern of red army corridor is constructed as"ring-shape-point".New ideas for protection and utilization as well as protection implementation measures are proposed,and the spiritual and cultural connotations of long march in Jiangxi are fully explored.This could help the social and economic development of the areas along the long march of red army in Jiangxi,and promote the integrated utilization and coordinated development of resources in the red cultural heritage corridor region.
文摘In this editorial,we comment on a recent article by Chen et al,that addressed the effect of intraoperative injection of esketamine on postoperative analgesia and postoperative rehabilitation after cesarean section.Poor management of postcesarean pain is associated with decreased maternal care for the baby,longer hospitalization,and higher risk of developing postpartum depression.Esketamine is a more potent S-enantiomer of ketamine which has shown promising analgesic and antidepressant properties for managing post-cesarean pain and depression in clinical studies.However,due to its potential adverse effects on the neurological and hemodynamic status of patients,it is recommended that its usage in low doses should be limited to cesarean candidates experiencing unbearable pain.Before any recommendation for routine perioperative use of esketamine,more standardized clinical trials are needed to strengthen our existing knowledge of its effectiveness in reducing postpartum pain and depression.
基金The National Natural Science Foundation of China(No.52338011,52378291)Young Elite Scientists Sponsorship Program by CAST(No.2022-2024QNRC0101).
文摘To overcome the limitations of low efficiency and reliance on manual processes in the measurement of geometric parameters for bridge prefabricated components,a method based on deep learning and computer vision is developed to identify the geometric parameters.The study utilizes a common precast element for highway bridges as the research subject.First,edge feature points of the bridge component section are extracted from images of the precast component cross-sections by combining the Canny operator with mathematical morphology.Subsequently,a deep learning model is developed to identify the geometric parameters of the precast components using the extracted edge coordinates from the images as input and the predefined control parameters of the bridge section as output.A dataset is generated by varying the control parameters and noise levels for model training.Finally,field measurements are conducted to validate the accuracy of the developed method.The results indicate that the developed method effectively identifies the geometric parameters of bridge precast components,with an error rate maintained within 5%.
文摘The integration of image analysis through deep learning(DL)into rock classification represents a significant leap forward in geological research.While traditional methods remain invaluable for their expertise and historical context,DL offers a powerful complement by enhancing the speed,objectivity,and precision of the classification process.This research explores the significance of image data augmentation techniques in optimizing the performance of convolutional neural networks(CNNs)for geological image analysis,particularly in the classification of igneous,metamorphic,and sedimentary rock types from rock thin section(RTS)images.This study primarily focuses on classic image augmentation techniques and evaluates their impact on model accuracy and precision.Results demonstrate that augmentation techniques like Equalize significantly enhance the model's classification capabilities,achieving an F1-Score of 0.9869 for igneous rocks,0.9884 for metamorphic rocks,and 0.9929 for sedimentary rocks,representing improvements compared to the baseline original results.Moreover,the weighted average F1-Score across all classes and techniques is 0.9886,indicating an enhancement.Conversely,methods like Distort lead to decreased accuracy and F1-Score,with an F1-Score of 0.949 for igneous rocks,0.954 for metamorphic rocks,and 0.9416 for sedimentary rocks,exacerbating the performance compared to the baseline.The study underscores the practicality of image data augmentation in geological image classification and advocates for the adoption of DL methods in this domain for automation and improved results.The findings of this study can benefit various fields,including remote sensing,mineral exploration,and environmental monitoring,by enhancing the accuracy of geological image analysis both for scientific research and industrial applications.
基金supported by the Basic Research Development Program of China(No.JCKY2021607B036)the National Natural Science Foundation of China(No.52275512).
文摘There is an urgent need for the application of broadband Microwave Absorption(MA)structures on the leading edges of aircraft wings,which requires the MA structures to possess both the broadband MA performance and great surface conformability.To meet these requirements,we designed and fabricated a flexible bioinspired meta-structure with ultra-broadband MA,thin thickness and excellent surface conformality.The carbonyl iron powder-carbon nanotubes-polydimethylsiloxane composite was synthesized by physical blending method for fabricating the MA meta-structure.Through geometry-electromagnetic optimal design by heuristic optimization algorithm,the meta-structure mimicking to the nipple photonic nanostructures on the eyes of moth can achieve ultra-broadband MA performance of 35.14 GHz MA bandwidth(reflection loss≤–10 dB),covering 4.86–40.00 GHz,with thickness of only 4.3 mm.Through simple fabrication processes,the meta-structure has been successfully fabricated and bonded on wings’leading edges,exhibiting excellent surface conformability.Furthermore,the designed flexible MA meta-structure possesses significant Radar Cross-Section(RCS)reduction capability,as demonstrated by the RCS analysis of an unmanned aerial vehicle.This flexible ultra-broadband MA meta-structure provides an outstanding candidate to meet the radar stealth requirement of variable curvature structures on aircraft.
