Featured Column — DATA PAPER

     Chinese Physics B begins to accept and publish “Data Papers” in 2021. 

     Aiming to promote the sharing and reuse of physical data, the Data Paper is dedicated to publishing experimental, theoretical, and computational data (dataset or database) with high quality and reuse value in physics. The data will be deposited in an accredited data repository, and data records are linked in the Data Paper to facilitate data access.

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    High-throughput identification of one-dimensional atomic wires and first principles calculations of their electronic states
    Feng Lu(卢峰), Jintao Cui(崔锦韬), Pan Liu(刘盼), Meichen Lin(林玫辰), Yahui Cheng(程雅慧), Hui Liu(刘晖), Weichao Wang(王卫超), Kyeongjae Cho, and Wei-Hua Wang(王维华)
    Chin. Phys. B, 2021, 30 (5): 057304.   DOI: 10.1088/1674-1056/abdb1a
    Abstract855)   HTML22)    PDF (910KB)(604)      
    Low dimensional materials are suitable candidates applying in next-generation high-performance electronic, optoelectronic, and energy storage devices because of their uniquely physical and chemical properties. In particular, one-dimensional (1D) atomic wires (AWs) exfoliating from 1D van der Waals (vdW) bulks are more promising in next generation nanometer (nm) even sub-nm device applications owing to their width of few-atoms scale and free dandling bonds states. Although several 1D AWs have been experimentally prepared, few 1D AW candidates could be practically applied in devices owing to lack of enough suitable 1D AWs. Herein, 367 kinds of 1D AWs have been screened and the corresponding computational database including structures, electronic structures, magnetic states, and stabilities of these 1D AWs has been organized and established. Among these systems, unary and binary 1D AWs with relatively small exfoliation energy are thermodynamically stable and theoretically feasible to be exfoliated. More significantly, rich quantum states emerge, such as 1D semiconductors, 1D metals, 1D semimetals, and 1D magnetism. This database will offer an ideal platform to further explore exotic quantum states and exploit practical device applications using 1D materials. The database are openly available at http://www.dx.doi.org/10.11922/sciencedb.j00113.00004.
    Evaluation of performance of machine learning methods in mining structure—property data of halide perovskite materials
    Ruoting Zhao(赵若廷), Bangyu Xing(邢邦昱), Huimin Mu(穆慧敏), Yuhao Fu(付钰豪), and Lijun Zhang(张立军)
    Chin. Phys. B, 2022, 31 (5): 056302.   DOI: 10.1088/1674-1056/ac5d2d
    Abstract626)   HTML8)    PDF (1248KB)(607)      
    With the rapid development of artificial intelligence and machine learning (ML) methods, materials science is rapidly entering the era of data-driven materials informatics. ML models serve as the most crucial component, closely bridging material structure and material properties. There is a considerable difference in the prediction performance of different ML methods for material systems. Herein, we evaluated three categories (linear, kernel, and nonlinear methods) of models, with twelve ML algorithms commonly used in the materials field. In addition, halide perovskite was chosen as an example to evaluate the fitting performance of different models. We constructed a total dataset of 540 halide perovskites and 72 features, with formation energy and bandgap as target properties. We found that different categories of ML models show similar trends for different target properties. Among them, the difference between the models is enormous for the formation energy, with the coefficient of determination (R2) range 0.69-0.953. The fitting performance between the models is closer for bandgap, with the R2 range 0.941-0.997. The nonlinear-ensemble model shows the best fitting performance for both the formation energy and the bandgap. It shows that the nonlinear-ensemble model, constructed by combining multiple weak learners, effectively describes the nonlinear relationship between material features and target property. In addition, the extreme gradient boosting decision tree model shows the most superior results among all the models and searches for two new descriptors that are crucial for formation energy and bandgap. Our work provides useful guidance for the selection of effective machine learning methods in the data-mining studies of specific material systems. The dataset that supported the findings of this study is available in Science Data Bank, with the link https://www.doi.org/10.11922/sciencedb.01611.
    Integral cross sections for electron impact excitations of argon and carbon dioxide
    Shu-Xing Wang(汪书兴) and Lin-Fan Zhu(朱林繁)
    Chin. Phys. B, 2022, 31 (8): 083401.   DOI: 10.1088/1674-1056/ac6336
    Abstract525)   HTML0)    PDF (3591KB)(156)      
    Electron-impact excitation integral cross sections play an important role in understanding the energy transfer processes in many applied physics. Practical applications require integral cross sections in a wide collision energy range from the excitation threshold to several keV. The recently developed BE-scaling method is able to meet the demands of integral cross sections for dipole-allowed transitions while the prerequisite relies on the accurate generalized oscillator strengths. Fast electron and x-ray scatterings are the conventional experimental techniques to approach the generalized oscillator strengths, and the joint study by both methods can provide credible cross-checks. The validated generalized oscillator strengths can then be used to extrapolate optical oscillator strengths by fitting the data with the Lassettre formula. The fitted curve also enables the integration of generalized oscillator strengths over the whole momentum transfer region to obtain the BE-scaled integral excitation cross sections. Here, experimental measurements by both fast electron and x-ray scattering of argon and carbon dioxide are reviewed. The integral cross sections for some low-lying states are derived from the cross-checked generalized oscillator strengths for the first time. The integral cross sections presented in this paper are openly available at https://doi.org/10.11922/sciencedb.01466.
    Measurement of 232Th (n,γ) cross section at the CSNS Back-n facility in the unresolved resonance region from 4 keV to 100 keV
    Bing Jiang(姜炳), Jianlong Han(韩建龙), Jie Ren(任杰), Wei Jiang(蒋伟), Xiaohe Wang(王小鹤), Zian Guo(郭子安), Jianglin Zhang(张江林), Jifeng Hu(胡继峰), Jingen Chen(陈金根), Xiangzhou Cai(蔡翔舟), Hongwei Wang(王宏伟), Longxiang Liu(刘龙祥), Xinxiang Li(李鑫祥), Xinrong Hu(胡新荣), and Yue Zhang(张岳)
    Chin. Phys. B, 2022, 31 (6): 060101.   DOI: 10.1088/1674-1056/ac5394
    Abstract501)   HTML3)    PDF (2248KB)(164)      
    The neutron capture cross section of 232Th was measured at the neutron time-of-flight facility Back-n of China Spallation Neutron Source (CSNS) for the first time. The measurement was performed with 4 hydrogen-free deuterated benzene C6D6 liquid scintillation detectors, in the ES#2 experiment station on the beam line, at a distance of about 76 m from the neutron-production assembly. The total energy detection principle in combination with the pulse height weighting technique (PHWT) was applied to analyze the measured data. Results of the 232Th (n,γ) reaction cross section in the unresolved resonance region from 4 keV to 100 keV were obtained, which shows a good agreement with the existing experimental data from EXFOR, as well as with the evaluated data from the ENDF/B-VIII.0 and CENDL-3.1. In addition, the excitation function of 232Th (n,γ)233Th reaction in the unresolved resonance region was theoretically calculated by using the code TALYS-1.95. By fitting the experimental cross section and theoretical data, the average parameters in the unresolved resonance region were extracted. The datasets are openly available at http://dx.doi.org/10.11922/sciencedb.j00113.00015.
    New experimental measurement of natSe(n, γ) cross section between 1 eV to 1 keV at the CSNS Back-n facility
    Xin-Rong Hu(胡新荣), Long-Xiang Liu(刘龙祥), Wei Jiang(蒋伟), Jie Ren(任杰), Gong-Tao Fan(范功涛), Hong-Wei Wang(王宏伟), Xi-Guang Cao(曹喜光), Long-Long Song(宋龙龙), Ying-Du Liu(刘应都), Yue Zhang(张岳), Xin-Xiang Li(李鑫祥), Zi-Rui Hao(郝子锐), Pan Kuang(匡攀), Xiao-He Wang(王小鹤), Ji-Feng Hu(胡继峰), Bing Jiang(姜炳), De-Xin Wang(王德鑫), Suyalatu Zhang(张苏雅拉吐), Zhen-Dong An(安振东), Yu-Ting Wang(王玉廷), Chun-Wang Ma(马春旺), Jian-Jun He(何建军), Jun Su(苏俊), Li-Yong Zhang(张立勇), Yu-Xuan Yang(杨宇萱), Sheng Jin(金晟), and Kai-Jie Chen(陈开杰)
    Chin. Phys. B, 2022, 31 (8): 080101.   DOI: 10.1088/1674-1056/ac6ee2
    Abstract498)   HTML0)    PDF (2402KB)(148)      
    The 74Se is one of 35 p-nuclei, and 82Se is a r-process only nucleus, and their (n, γ) cross sections are vital input parameters for nuclear astrophysics reaction network calculations. The neutron capture cross section in the resonance range of isotopes and even natural selenium samples has not been measured. Prompt γ-rays originating from neutron-induced capture events were detected by four C6D6 liquid scintillator detectors at the Back-n facility of China Spallation Neutron Source (CSNS). The pulse height weighting technique (PHWT) was used to analyze the data in the 1 eV to 100 keV region. The deduced neutron capture cross section was compared with ENDF/B-VIII.0, JEFF-3.2, and JENDL-4.0, and some differences were found. Resonance parameters were extracted by the R-matrix code SAMMY in the 1 eV-1 keV region. All the cross sections of natSe and resonance parameters are given in the datasets. The datasets are openly available at http://www.doi.org/10.11922/sciencedb.j00113.00019.
    Energy levels and magnetic dipole transition parameters for the nitrogen isoelectronic sequence
    Mu-Hong Hu(胡木宏), Nan Wang(王楠), Pin-Jun Ouyang(欧阳品均),Xin-Jie Feng(冯新杰), Yang Yang(杨扬), and Chen-Sheng Wu(武晨晟)
    Chin. Phys. B, 2022, 31 (9): 093101.   DOI: 10.1088/1674-1056/ac7a12
    Abstract433)   HTML7)    PDF (905KB)(258)      
    Theoretical calculations of the energy levels and magnetic dipole transition parameters for the 1s22s22p3 and 1s22p5 configurations of nitrogen isoelectronic sequence with Z=21-30 are performed using multi-congfiguration Dirac-Fock (MCDF) method. Based on the relativistic computational code GRASP2k compiled within the framework of MCDF method, the electron correlations, Breit interaction and QED effects are well treated in detail. The energy levels, line strengths and transition rates of magnetic dipole transition are obtained and compared with the experimental data available. For most cases, good agreements are achieved and the relative differences of them are less than 0.114%, 8.43% and 9.80%, respectively. The scaling laws of the fine structure splitting and transition rate are obtained on the isoelectronic sequence and the corresponding physical mechanisms are discussed. The data sets for tables are openly available at https://www.doi.org/10.57760/sciencedb.j00113.00022.
    Magnetic properties of oxides and silicon single crystals
    Zhong-Xue Huang(黄忠学), Rui Wang(王瑞), Xin Yang(杨鑫), Hao-Feng Chen(陈浩锋), and Li-Xin Cao(曹立新)
    Chin. Phys. B, 2022, 31 (8): 087501.   DOI: 10.1088/1674-1056/ac70c2
    Abstract427)   HTML6)    PDF (915KB)(297)      
    The magnetic properties of single crystals Si, SrTiO3, LaAlO3, MgO, and (La,Sr)(Al,Ta)O3 were investigated systematically. Three origins of the magnetizations of these crystals, namely, an intrinsic diamagnetic, a paramagnetic, and a ferromagnetic contribution, have been found to influence the magnetic signals measured on the crystals, in some important application scenarios such crystals being served as substrates with the magnetic thin film epitaxially grown on. Quantitative analyses methodologies were developed and thorough investigations were performed on the crystals with the intrinsic materials parameters thus revealed, especially that the intrinsic diamagnetic susceptibility differential dχdia/dT were identified quantitatively for the first time in SrTiO3, LaAlO3, MgO, and (La,Sr)(Al,Ta)O3. The paramagnetic contribution is found to be the key in terms of the magnetic properties of the crystals, which in turn is in fact a consequence of the 3d impurities doping inside the crystal. All the intrinsic materials parameters are given in this paper as datasets, the datasets are openly available at https://www.doi.org/10.57760/sciencedb.j00113.00028.
    Neutron activation cross section data library
    Xiao-Long Huang(黄小龙), Zhi-Gang Ge(葛智刚), Yong-Li Jin(金永利), Hai-Cheng Wu(吴海成), Xi Tao(陶曦),Ji-Min Wang(王记民), Li-Le Liu(刘丽乐), Yue Zhang(张玥), and Xiao-Fei Wu(吴小飞)
    Chin. Phys. B, 2022, 31 (6): 060102.   DOI: 10.1088/1674-1056/ac657e
    Abstract426)   HTML6)    PDF (860KB)(191)      
    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. The full evaluated dataset containing the evaluated activation cross sections is openly available at http://doi.org/10.57760/sciencedb.j00113.00024.
    Measurements of the 107Ag neutron capture cross sections with pulse height weighting technique at the CSNS Back-n facility
    Xin-Xiang Li(李鑫祥), Long-Xiang Liu(刘龙祥), Wei Jiang(蒋伟), Jie Ren(任杰), Hong-Wei Wang(王宏伟), Gong-Tao Fan(范功涛), Jian-Jun He(何建军), Xi-Guang Cao(曹喜光), Long-Long Song(宋龙龙),Yue Zhang(张岳), Xin-Rong Hu(胡新荣), Zi-Rui Hao(郝子锐), Pan Kuang(匡攀), Bing Jiang(姜炳),Xiao-He Wang(王小鹤), Ji-Feng Hu(胡继峰), Jin-Cheng Wang(王金成), De-Xin Wang(王德鑫),Su-Yalatu Zhang(张苏雅拉吐), Ying-Du Liu(刘应都), Xu Ma(麻旭), Chun-Wang Ma(马春旺),Yu-Ting Wang(王玉廷), Zhen-Dong An(安振东), Jun Su(苏俊), Li-Yong Zhang(张立勇),Yu-Xuan Yang(杨宇萱), Wen-Bo Liu(刘文博), Wan-Qing Su(苏琬晴),Sheng Jin(金晟), and Kai-Jie Chen(陈开杰)
    Chin. Phys. B, 2022, 31 (3): 038204.   DOI: 10.1088/1674-1056/ac48fd
    Abstract416)   HTML3)    PDF (3383KB)(229)      
    Silver indium cadmium (Ag-In-Cd) control rod is widely used in pressurized water reactor nuclear power plants, and it is continuously consumed in a high neutron flux environment. The mass ratio of 107Ag in the Ag-In-Cd control rod is 41.44%. To accurately calculate the consumption value of the control rod, a reliable neutron reaction cross section of the 107Ag is required. Meanwhile, 107Ag is also an important weak r nucleus. Thus, the cross sections for neutron induced interactions with 107Ag are very important both in nuclear energy and nuclear astrophysics. The (n,γ) cross section of 107Ag has been measured in the energy range of 1-60 eV using a back streaming white neutron beam line at China spallation neutron source. The resonance parameters are extracted by an R-matrix code. All the cross section of 107Ag and resonance parameters are given in this paper as datasets. The datasets are openly available at http://www.doi.org/10.11922/sciencedb.j00113.00010.
    State-to-state integral cross sections and rate constants for the N+(3P)+HD→NH+/ND++D/H reaction: Accurate quantum dynamics studies
    Hanghang Chen(陈航航), Zijiang Yang(杨紫江), and Maodu Chen(陈茂笃)
    Chin. Phys. B, 2022, 31 (9): 098204.   DOI: 10.1088/1674-1056/ac7e3a
    Abstract411)   HTML1)    PDF (983KB)(91)      
    The reactive collisions of nitrogen ion with hydrogen and its isotopic variations have great significance in the field of astrophysics. Herein, the state-to-state quantum time-dependent wave packet calculations of N$^{+}$($^{3}$P)$+{\rm HD}\to {\rm NH}^{+}$/ND$^{+} +{\rm D/H}$ reaction are carried out based on the recently developed potential energy surface [Phys. Chem. Chem. Phys. 21 22203 (2019)]. The integral cross sections (ICSs) and rate coefficients of both channels are precisely determined at the state-to-state level. The results of total ICSs and rate coefficients present a dramatic preference on the ND$^{+}$ product over the NH$^{+}$ product, conforming to the long-lived complex-forming mechanism. Product state-resolved ICSs indicate that both the product molecules are difficult to excite to higher vibrational states, and the ND$^{+}$ product has a hotter rotational state distribution. Moreover, the integral cross sections and rate coefficients are precisely determined at the state-to-state level and insights are provided about the differences between the two channels. The present results would provide an important reference for the further experimental studies at the finer level for this interstellar chemical reaction. The datasets presented in this paper, including the ICSs and rate coefficients of the two products for the title reaction, are openly available at https://www.doi.org/10.57760/sciencedb.j00113.00034.
    Electron excitation processes in low energy collisions of hydrogen-helium atoms
    Kun Wang(王堃), Chuan Dong(董川), Yi-Zhi Qu(屈一至), Ling Liu(刘玲), Yong Wu(吴勇),Xu-Hai Hong(洪许海), and Robert J. Buenker
    Chin. Phys. B, 2022, 31 (12): 123401.   DOI: 10.1088/1674-1056/aca14c
    Abstract391)   HTML1)    PDF (603KB)(241)      
    The electron excitation processes of $\rm H(1s) + He(1s^{2}) \to H(2s/2p) + He(1s^{2})$ are studied in impact energy range of 20—2000 eV/u by using the quantum-mechanical molecular orbital close-coupling (QMOCC) method. Total and state-selective cross sections have been obtained and compared with the available theoretical and experimental results. The results agree well with available measurements in the overlapping energy regions overall. The comparison of our results with other theoretical calculations further demonstrates the importance of considering a sufficient number of channels. The datasets presented in this paper, including the excitation cross sections, are openly available at https://www.doi.org/10.57760/sciencedb.j00113.00083.
    Atlas of dynamic spectra of fast radio burst FRB 20201124A
    Bo-Jun Wang(王铂钧), Heng Xu(胥恒), Jin-Chen Jiang(姜金辰), Jiang-Wei Xu(徐江伟), Jia-Rui Niu(牛佳瑞), Ping Chen(陈平), Ke-Jia Lee(李柯伽), Bing Zhang(张冰), Wei-Wei Zhu(朱炜玮), Su-Bo Dong(东苏勃), Chun-Feng Zhang(张春风), Hai Fu(傅海), De-Jiang Zhou(周德江), Yong-Kun Zhang(张永坤), Pei Wang(王培), Yi Feng(冯毅), Ye Li(李晔), Dong-Zi Li(李冬子), Wen-Bin Lu(鲁文宾), Yuan-Pei Yang(杨元培), R. N. Caballero, Ce Cai(蔡策), Mao-Zheng Chen(陈卯蒸), Zi-Gao Dai(戴子高), A. Esamdin(艾力·伊沙木丁), Heng-Qian Gan(甘恒谦), Jin-Lin Han(韩金林), Long-Fei Hao(郝龙飞), Yu-Xiang Huang(黄玉祥), Peng Jiang(姜鹏), Cheng-Kui Li(李承奎), Di Li(李菂), Hui Li(李辉), Xin-Qiao Li(李新乔), Zhi-Xuan Li(李志玄), Zhi-Yong Liu(刘志勇), Rui Luo(罗睿), Yun-Peng Men(门云鹏), Chen-Hui Niu(牛晨辉), Wen-Xi Peng(彭文溪), Lei Qian(钱磊), Li-Ming Song(宋黎明), Jing-Hai Sun(孙京海), Fa-Yin Wang(王发印), Min Wang(汪敏), Na Wang(王娜), Wei-Yang Wang(王维扬), Xue-Feng Wu(吴雪峰), Shuo Xiao(肖硕), Shao-Lin Xiong(熊少林), Yong-Hua Xu(徐永华), Ren-Xin Xu(徐仁新), Jun Yang(杨俊), Xuan Yang(杨轩), Rui Yao(姚蕊), Qi-Bin Yi(易祁彬), You-Ling Yue(岳友岭), Dong-Jun Yu(于东俊), Wen-Fei Yu(余文飞), Jian-Ping Yuan(袁建平), Bin-Bin Zhang(张彬彬), Song-Bo Zhang(张松波), Shuang-Nan Zhang(张双南), Yi Zhao(赵一), Wei-Kang Zheng(郑伟康), Yan Zhu(朱岩), and Jin-Hang Zou(邹金航)
    Chin. Phys. B, 2023, 32 (2): 029801.   DOI: 10.1088/1674-1056/aca7ed
    Abstract380)   HTML10)    PDF (1500KB)(256)      
    Fast radio bursts (FRBs) are highly dispersed millisecond-duration radio bursts,[1,2] of which the physical origin is still not fully understood. FRB 20201124A is one of the most actively repeating FRBs. In this paper, we present the collection of 1863 burst dynamic spectra of FRB 20201124A measured with the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The current collection, taken from the observation during the FRB active phase from April to June 2021, is the largest burst sample detected for any FRB so far. The standard PSRFITs format is adopted, including dynamic spectra of the burst, and the time information of the dynamic spectra, in addition, mask files help readers to identify the pulse positions are also provided. The dataset is available in Science Data Bank, with the link https://www.doi.org/10.57760/sciencedb.j00113.00076.
    Measuring stellar populations, dust attenuation and ionized gas at kpc scales in 10010 nearby galaxies using the integral field spectroscopy from MaNGA
    Niu Li(李牛) and Cheng Li(李成)
    Chin. Phys. B, 2023, 32 (3): 039801.   DOI: 10.1088/1674-1056/acb0ba
    Abstract358)   HTML7)    PDF (1004KB)(245)      
    As one of the three major experiments of the fourth-generation Sloan Digital Sky Survey (SDSS-IV), the Mapping Nearby Galaxies at Apatch Point Observatory (MaNGA) survey has obtained high-quality integral field spectroscopy (IFS) with a resolution of 1-2 kpc for ~104 galaxies in the local universe during its six-year operation from July 2014 through August 2020. It is crucial to reliably measure the physical properties of the different components in each spectrum before one can use the data for any scientific study. In the past years we have made lots of efforts to develop a novel technique of full spectral fitting, which estimates a model-independent dust attenuation curve from each spectrum, thus allowing us to break the degeneracy between dust attenuation and stellar population properties when fitting the spectrum with stellar population synthesis models. We have applied our technique to the final data release of MaNGA, and obtained measurements of stellar population properties and emission line parameters, as well as the kinematics and dust attenuation of both stellar and ionized gas components. In this paper we describe our technique and the content and format of our data products. The whole dataset is publicly available in Science Data Bank with the link https://doi.org/10.57760/sciencedb.j00113.00088.
    Relativistic calculations on the transition electric dipole moments and radiative lifetimes of the spin-forbidden transitions in the antimony hydride molecule
    Yong Liu(刘勇), Lu-Lu Li(李露露), Li-Dan Xiao(肖利丹), and Bing Yan(闫冰)
    Chin. Phys. B, 2022, 31 (8): 083101.   DOI: 10.1088/1674-1056/ac6ee1
    Abstract347)   HTML0)    PDF (888KB)(145)      
    Calculations on the spectroscopic constants and transition properties of the first three states (${\rm a}^{1}\Delta $, ${\rm b}^{1}\Sigma^{+}$, and X$^{3}\Sigma^-$) of the SbH molecule were performed under the relativistic framework using the exact two-component Hamiltonian (X2C). The potential energy curves in the Franck-Condon region were computed and compared with the previous values. Furthermore, the transition dipole moments for the weak spin-forbidden transitions (${\rm b}0^{+}$-X$_{1}0^{+}$, ${\rm b}0^{+}$-X$_{2}$1, X$_{1}0^{+}$-X$_{2}$1, and X$_{2}$1-${\rm a}$2) were reported. The spontaneous radiative lifetime of the ${\rm b}^{1}\Sigma^{+}$ ($\upsilon '=0$) state was calculated as 163.5 $\pm$ 7.5 μs, which is in reasonable agreement with the latest experimental value of 173 $\pm$ 3 μs. The spontaneous radiative lifetimes of the X$_{2}$1 ($\upsilon '=0$) state and the ${\rm a}$2 ($\upsilon '=0$) state were calculated to be 48.6 s and $\sim 8 $ ms, respectively. Our study is expected to be a benchmark transition property computation for comparison with other theoretical and experimental results. The datasets presented in this paper, including the transition dipole moments, are openly available at https://dx.doi.org/10.11922/sciencedb.j00113.00018.
    Time-resolved K-shell x-ray spectra of nanosecond laser-produced titanium tracer in gold plasmas
    Zhencen He(何贞岑), Jiyan Zhang(张继彦), Jiamin Yang(杨家敏), Bing Yan(闫冰), and Zhimin Hu(胡智民)
    Chin. Phys. B, 2023, 32 (1): 015202.   DOI: 10.1088/1674-1056/ac8e95
    Abstract342)   HTML3)    PDF (1274KB)(137)      
    A study of a nanosecond laser irradiation on the titanium-layer-buried gold planar target is presented. The time-resolved x-ray emission spectra of titanium tracer are measured by a streaked crystal spectrometer. By comparing the simulated spectra obtained by using the FLYCHK code with the measured titanium spectra, the temporal plasma states, i.e., the electron temperatures and densities, are deduced. To evaluate the feasibility of using the method for the characterization of Au plasma states, the deduced plasma states from the measured titanium spectra are compared with the Multi-1D hydrodynamic simulations of laser-produced Au plasmas. By comparing the measured and simulated results, an overall agreement for the electron temperatures is found, whereas there are deviations in the electron densities. The experiment-theory discrepancy may suggest that the plasma state could not be well reproduced by the Multi-1D hydrodynamic simulation, in which the radial gradient is not taken into account. Further investigations on the spectral characterization and hydrodynamic simulations of the plasma states are needed. All the measured and FLYCHK simulated spectra are given in this paper as datasets. The datasets are openly available at http://www.doi.org/10.57760/sciencedb.j00113.00032.
    LAMOST medium-resolution spectroscopic survey of binarity and exotic star (LAMOST-MRS-B): Observation strategy and target selection
    Jiao Li(李蛟), Jiang-Dan Li(李江丹), Yan-Jun Guo(郭彦君), Zhan-Wen Han(韩占文), Xue-Fei Chen(陈雪飞), Chao Liu(刘超), Hong-Wei Ge(葛宏伟), Deng-Kai Jiang(姜登凯), Li-Fang Li(李立芳), Bo Zhang(章博), Jia-Ming Liu(刘佳明), Hao Tian(田浩), Hao-Tong Zhang(张昊彤), Hai-Long Yuan(袁海龙), Wen-Yuan Cui(崔文元),Juan-Juan Ren(任娟娟), Jing-Hao Cai(蔡靖豪), and Jian-Rong Shi(施建荣)
    Chin. Phys. B, 2023, 32 (1): 019501.   DOI: 10.1088/1674-1056/ac9362
    Abstract315)   HTML3)    PDF (3317KB)(196)      
    LAMOST-MRS-B is one of the sub-surveys of LAMOST medium-resolution ($R\sim7500$) spectroscopic survey. It aims at studying the statistical properties (e.g., binary fraction, orbital period distribution, mass ratio distribution) of binary stars and exotic stars. We intend to observe about 30000 stars ($10 {\rm mag}\leq G < 14.5$ mag) with at least 10 visits in five years. We first planned to observe 25 plates around the galactic plane in 2018. Then the plates were reduced to 12 in 2019 because of the limitation of observation. At the same time, two new plates located at the high galactic latitude were added to explore binary properties influenced by the different environments. In this survey project, we set the identified exotic and low-metallicity stars with the highest observation priorities. For the rest of the selected stars, we gave the higher priority to the relatively brighter stars in order to obtain high quality spectra as many as possible. Spectra of 49129 stars have been obtained in LAMOST-MRS-B field and released in DR8, of which 28828 and 3375 stars have been visited more than twice and ten times with $\rm SNR \geq 10$, respectively. Most of the sources are B-, A-, and F-type stars with $\rm -0.6< [Fe/H] < 0.4 $ dex. We also obtain 347 identified variable and exotic stars and about 250 stars with $\rm [Fe/H] <-1$ dex. We measure radial velocities (RVs) by using 892233 spectra of the stars. The uncertainties of RV achieve about $1$ ${\rm km \cdot s^{-1}}$and $10$ ${\rm km \cdot s^{-1}}$ for 95% of late- and early-type stars, respectively. The datasets presented in this paper are available at http://www.doi.org/10.57760/sciencedb.j00113.00035.
    Evaluating thermal expansion in fluorides and oxides: Machine learning predictions with connectivity descriptors
    Yilin Zhang(张轶霖), Huimin Mu(穆慧敏), Yuxin Cai(蔡雨欣), Xiaoyu Wang(王啸宇), Kun Zhou(周琨), Fuyu Tian(田伏钰), Yuhao Fu(付钰豪), and Lijun Zhang(张立军)
    Chin. Phys. B, 2023, 32 (5): 056302.   DOI: 10.1088/1674-1056/accdca
    Abstract284)   HTML6)    PDF (1865KB)(274)      
    Open framework structures (e.g., ScF3, Sc2W3O12, etc.) exhibit significant potential for thermal expansion tailoring owing to their high atomic vibrational degrees of freedom and diverse connectivity between polyhedral units, displaying positive/negative thermal expansion (PTE/NTE) coefficients at a certain temperature. Despite the proposal of several physical mechanisms to explain the origin of NTE, an accurate mapping relationship between the structural-compositional properties and thermal expansion behavior is still lacking. This deficiency impedes the rapid evaluation of thermal expansion properties and hinders the design and development of such materials. We developed an algorithm for identifying and characterizing the connection patterns of structural units in open-framework structures and constructed a descriptor set for the thermal expansion properties of this system, which is composed of connectivity and elemental information. Our developed descriptor, aided by machine learning (ML) algorithms, can effectively learn the thermal expansion behavior in small sample datasets collected from literature-reported experimental data (246 samples). The trained model can accurately distinguish the thermal expansion behavior (PTE/NTE), achieving an accuracy of 92%. Additionally, our model predicted six new thermodynamically stable NTE materials, which were validated through first-principles calculations. Our results demonstrate that developing effective descriptors closely related to thermal expansion properties enables ML models to make accurate predictions even on small sample datasets, providing a new perspective for understanding the relationship between connectivity and thermal expansion properties in the open framework structure. The datasets that were used to support these results are available on Science Data Bank, accessible via the link https://doi.org/10.57760/sciencedb.j00113.00100.
    Theoretical study of electron-impact broadening for highly charged Ar XV ion lines
    Chao Wu(吴超), Xiang Gao(高翔), Yu-Hao Zhu(朱宇豪), Xiao-Ying Han(韩小英), Bin Duan(段斌),Ju Meng(孟举), Song-Bin Zhang(张松斌), Jun Yan(颜君), Yong Wu(吴勇), and Jian-Guo Wang(王建国)
    Chin. Phys. B, 2023, 32 (5): 053101.   DOI: 10.1088/1674-1056/acb769
    Abstract235)   HTML4)    PDF (1069KB)(241)      
    Spectral line widths produced by collisions between charged particles and emitters are of special interest for precise plasma spectroscopy. The highly charged Ar XV ion is demonstrated to have strong intrashell electron interactions, which manifest as an atomic system with many resonance structures, due to the quasi-degeneracy of orbital energies. In this paper we use the relativistic R-matrix method to investigate the electron-impact broadening of highly charged Ar XV ion spectral lines under the impact approximation. It is found that the results considering resonance structures are significantly different from those of the distorted wave approach. Furthermore, we propose a new empirical formula with a correction term to take into account the effect of resonances for electron-impact widths over a relatively wide range of plasma conditions. The corresponding fitting parameters of the new empirical formula for all 47 calculated transitions are also given with an estimated accuracy within 1%, which should be convenient for practical applications. The dataset that supported the findings of this study is available in Science Data Bank, with the link https://doi.org/10.57760/sciencedb.j00113.00101.
    Asymmetry parameters in single ionization of He, Ne by XUV pulses
    Jian-Ting Lei(雷建廷), Xuan Yu(余璇), Guo-Qiang Shi(史国强), Chen-Yu Tao(陶琛玉), Shao-Hua Sun(孙少华), Shun-Cheng Yan(闫顺成), Xin-Wen Ma(马新文), Jing-Jie Ding(丁晶洁), and Shao-Feng Zhang(张少锋)
    Chin. Phys. B, 2023, 32 (5): 053205.   DOI: 10.1088/1674-1056/aca6d9
    Abstract229)   HTML7)    PDF (1713KB)(150)      
    Fully differential cross-sections of single ionization of He and Ne atoms are studied by linearly polarized extreme ultraviolet (XUV) photons in the energy range of 22.1 eV-43.7 eV, using a reaction microscope. Photoelectron angular distributions and the $\beta $ asymmetry parameters for He 1s$^{2}$ electrons prove the reliability of our experiment, and the $\beta $ asymmetry parameters extracted from the angular distributions of Ne 2p$^{6}$ electrons are obtained. By comparing with different theoretical calculations, it is found that the contribution of the electron correlation effect in Ne 2p$^{6}$ single ionization becomes increasingly important as the incident photon energy increases, while the relativistic effect is relatively low in the whole incident energy range. Our experimental $\beta $ asymmetry parameters may serve as a significant reference to test the most elaborated theories in the field. The datasets presented in this paper, including the photoelectron angular distributions and $\beta $ asymmetry parameters, are openly available at https://doi.org/10.57760/sciencedb.j00113.00073.
    Mutual neutralization in low-energy collisions of Na+ + H- ions
    Kun Wang(王堃), Chuan Dong(董川), Yizhi Qu(屈一至), Yong Wu(吴勇), Xiaohe Lin(林晓贺), and Robert J. Buenker
    Chin. Phys. B, 2023, 32 (8): 083103.   DOI: 10.1088/1674-1056/acd624
    Abstract216)   HTML2)    PDF (768KB)(115)      
    The low-energy mutual neutralization (MN) reactions Na+ + H- →Na(nl) + H have been studied by employing the full quantum-mechanical molecular-orbital close-coupling (QMOCC) method over a wide energy range of 10-3-103 eV/u. Total and state-selective cross sections have been investigated and compared with the available theoretical and experimental data, and the state-selective rate coefficients for the temperature range of 100-10000 K have been obtained. In the present work, all the necessary highly excited states are included, and the influences of rotational couplings and 10 active electrons are considered. It is found that in the energy below 10 eV/u, the Na(4s) state is the most dominant exit state with a contribution of approximately 78% to the branch fraction, which is in best agreement with the experimental data. For energies above 10 eV/u, the MN total cross section is larger than those obtained in other theoretical calculations and shows a slow decreasing trend because the main exit states change, when the energy is above 100 eV/u, the dominant exit state becomes the Na(3p) state, while the Na(4s) state becomes the third most important exit state. The datasets presented in this paper, including the potential energy curve, the radial and rotational couplings, the total and state-selective cross sections, are openly available at https://doi.org/10.57760/sciencedb.j00113.00112.