Photoneutron cross-section(PNCS)data are important in various current and emerging applications.Although a few sophis-ticated methods have been developed,there is still an urgent need to study the PNCS data.In this st...Photoneutron cross-section(PNCS)data are important in various current and emerging applications.Although a few sophis-ticated methods have been developed,there is still an urgent need to study the PNCS data.In this study,we propose the extraction of PNCS distributions using a combination of gamma activation and reaction yield ratio methods.To verify the validity of the proposed extraction method,experiments for generating^(62,64)Cu and^(85m,87m)Sr isotopes via laser-induced pho-toneutron reactions were performed,and the reaction yields of these isotopes were obtained.Using the proposed extraction method,the PNCS distributions of^(63)Cu and^(86)Sr isotopes(leading to^(85m)Sr isotope production)were successfully extracted.These extracted PNCS distributions were benchmarked against available PNCS data or TALYS calculations,demonstrating the validity of the proposed extraction method.Potential applications for predicting the PNCS distributions of the 30 iso-topes are further introduced.We conclude that the proposed extraction method is an effective complement to the available sophisticated methods for measuring and evaluating PNCS data.展开更多
In this review, we highlight some recent methodological and theoretical develop- ments in estimation and testing of large panel data models with cross-sectional dependence. The paper begins with a discussion of issues...In this review, we highlight some recent methodological and theoretical develop- ments in estimation and testing of large panel data models with cross-sectional dependence. The paper begins with a discussion of issues of cross-sectional dependence, and introduces the concepts of weak and strong cross-sectional dependence. Then, the main attention is primarily paid to spatial and factor approaches for modeling cross-sectional dependence for both linear and nonlinear （nonparametric and semiparametric） panel data models. Finally, we conclude with some speculations on future research directions.展开更多
The calculation methods of production cross sections of γ-rays for thermal-neutron captures are briefly presented. The check of intensity balance is made. The examples are given to illustrate its application.
Radar cross section(RCS)is an important attribute of radar targets and has been widely used in automatic target recognition(ATR).In a passive radar,only the RCS multiplied by a coefficient is available due to the unkn...Radar cross section(RCS)is an important attribute of radar targets and has been widely used in automatic target recognition(ATR).In a passive radar,only the RCS multiplied by a coefficient is available due to the unknown transmitting parameters.For different transmitter-receiver(bistatic)pairs,the coefficients are different.Thus,the recovered RCS in different transmitter-receiver(bistatic)pairs cannot be fused for further use.In this paper,we propose a quantity named quasi-echo-power(QEP)as well as a method for eliminating differences of this quantity among different transmitter-receiver(bistatic)pairs.The QEP is defined as the target echo power after being compensated for distance and pattern propagation factor.The proposed method estimates the station difference coefficients(SDCs)of transmitter-receiver(bistatic)pairs relative to the reference transmitter-receiver(bistatic)pair first.Then,it compensates the QEP and gets the compensated QEP.The compensated QEP possesses a linear relationship with the target RCS.Statistical analyses on the simulated and real-life QEP data show that the proposed method can effectively estimate the SDC between different stations,and the compensated QEP from different receiving stations has the same distribution characteristics for the same target.展开更多
A twin gridded ionization chamber with dual parameter data acquisition sys-tem is used to study neutron induced charged particle emission reaction.The angulardistribution and cross section of n-particles from the <...A twin gridded ionization chamber with dual parameter data acquisition sys-tem is used to study neutron induced charged particle emission reaction.The angulardistribution and cross section of n-particles from the <sup>64</sup>Zn（n,α）<sup>61</sup>Ni reaction are meas-ured at neutron energy 5 MeV.展开更多
To satisfy the requirements of nuclear reaction cross sections in nuclear engineering applications and nuclear physics studies,the Neutron Activation Cross Section Data Library has been established.818 target nuclei i...To satisfy the requirements of nuclear reaction cross sections in nuclear engineering applications and nuclear physics studies,the Neutron Activation Cross Section Data Library has been established.818 target nuclei including unstable target or isomeric target nuclei are considered in this library.The induced neutron energy range region is between 10^(-5)eV and 20 MeV.The standard ENDF-6 format is adopted,including general information,reaction cross sections,multiplicities,and so on.The recommended reaction cross sections were obtained using UNF code system and FDRR nuclear model codes or systematic analysis based on available experimental data.展开更多
Residential water use is gradually becoming the focus in China's municipal water supply planning and management in recent years.Little is known,however,about the residential water use in modern China due to the tr...Residential water use is gradually becoming the focus in China's municipal water supply planning and management in recent years.Little is known,however,about the residential water use in modern China due to the transition of economy and enhancement of management on water conservation.In order to better understand the characteristics of residential water use in North China,a model for identifying the determinants of residential water use was established and analyzed by using panel data and cross-section data methodologies.Then Taiyuan city,the capital city of Shanxi Province in Northern China was selected as a case study.Both the analyses and field investigation indicate that the relatively slow increase of residential water use in recent years may result from the implementation of strict laws and regulations on water conservation.And through the investigation, first-hand information about water consumption pattern,water reuse/conservation,people's attitude toward water quantity and quality,etc.have been obtained.展开更多
基金This work was supported by the National Key R&D Program of China(No.2022YFA1603300)the National Natural Science Foundation of China(Nos.U2230133)+2 种基金the Independent Research Project of the Key Laboratory of Plasma Physics,CAEP(No.JCKYS2021212009)the Open Fund of the Key Laboratory of Nuclear Data,CIAE(No.JCKY2022201C152)Hengyang Municipal Science and Technology Project(No.202150054076).
文摘Photoneutron cross-section(PNCS)data are important in various current and emerging applications.Although a few sophis-ticated methods have been developed,there is still an urgent need to study the PNCS data.In this study,we propose the extraction of PNCS distributions using a combination of gamma activation and reaction yield ratio methods.To verify the validity of the proposed extraction method,experiments for generating^(62,64)Cu and^(85m,87m)Sr isotopes via laser-induced pho-toneutron reactions were performed,and the reaction yields of these isotopes were obtained.Using the proposed extraction method,the PNCS distributions of^(63)Cu and^(86)Sr isotopes(leading to^(85m)Sr isotope production)were successfully extracted.These extracted PNCS distributions were benchmarked against available PNCS data or TALYS calculations,demonstrating the validity of the proposed extraction method.Potential applications for predicting the PNCS distributions of the 30 iso-topes are further introduced.We conclude that the proposed extraction method is an effective complement to the available sophisticated methods for measuring and evaluating PNCS data.
基金Supported by the National Natural Science Foundation of China(71131008(Key Project)and 71271179)
文摘In this review, we highlight some recent methodological and theoretical develop- ments in estimation and testing of large panel data models with cross-sectional dependence. The paper begins with a discussion of issues of cross-sectional dependence, and introduces the concepts of weak and strong cross-sectional dependence. Then, the main attention is primarily paid to spatial and factor approaches for modeling cross-sectional dependence for both linear and nonlinear （nonparametric and semiparametric） panel data models. Finally, we conclude with some speculations on future research directions.
文摘The calculation methods of production cross sections of γ-rays for thermal-neutron captures are briefly presented. The check of intensity balance is made. The examples are given to illustrate its application.
基金supported by the National Natural Science Foundation of China(61931015,62071335)the Science and Technology Program of Shenzhen(JCYJ20170818112037398)the Technological Innovation Project of Hubei Province of China(2019AAA061).
文摘Radar cross section(RCS)is an important attribute of radar targets and has been widely used in automatic target recognition(ATR).In a passive radar,only the RCS multiplied by a coefficient is available due to the unknown transmitting parameters.For different transmitter-receiver(bistatic)pairs,the coefficients are different.Thus,the recovered RCS in different transmitter-receiver(bistatic)pairs cannot be fused for further use.In this paper,we propose a quantity named quasi-echo-power(QEP)as well as a method for eliminating differences of this quantity among different transmitter-receiver(bistatic)pairs.The QEP is defined as the target echo power after being compensated for distance and pattern propagation factor.The proposed method estimates the station difference coefficients(SDCs)of transmitter-receiver(bistatic)pairs relative to the reference transmitter-receiver(bistatic)pair first.Then,it compensates the QEP and gets the compensated QEP.The compensated QEP possesses a linear relationship with the target RCS.Statistical analyses on the simulated and real-life QEP data show that the proposed method can effectively estimate the SDC between different stations,and the compensated QEP from different receiving stations has the same distribution characteristics for the same target.
基金The project supported by the National Natural Science Foundation of China and China National Nuclear Corporation
文摘A twin gridded ionization chamber with dual parameter data acquisition sys-tem is used to study neutron induced charged particle emission reaction.The angulardistribution and cross section of n-particles from the <sup>64</sup>Zn（n,α）<sup>61</sup>Ni reaction are meas-ured at neutron energy 5 MeV.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11934004 and U1832201)the Science Challenge Project (Grant No. TZ2016005)the CAEP Foundation (Grant No. CX2019022)
文摘To satisfy the requirements of nuclear reaction cross sections in nuclear engineering applications and nuclear physics studies,the Neutron Activation Cross Section Data Library has been established.818 target nuclei including unstable target or isomeric target nuclei are considered in this library.The induced neutron energy range region is between 10^(-5)eV and 20 MeV.The standard ENDF-6 format is adopted,including general information,reaction cross sections,multiplicities,and so on.The recommended reaction cross sections were obtained using UNF code system and FDRR nuclear model codes or systematic analysis based on available experimental data.
文摘Residential water use is gradually becoming the focus in China's municipal water supply planning and management in recent years.Little is known,however,about the residential water use in modern China due to the transition of economy and enhancement of management on water conservation.In order to better understand the characteristics of residential water use in North China,a model for identifying the determinants of residential water use was established and analyzed by using panel data and cross-section data methodologies.Then Taiyuan city,the capital city of Shanxi Province in Northern China was selected as a case study.Both the analyses and field investigation indicate that the relatively slow increase of residential water use in recent years may result from the implementation of strict laws and regulations on water conservation.And through the investigation, first-hand information about water consumption pattern,water reuse/conservation,people's attitude toward water quantity and quality,etc.have been obtained.
