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Searching for^(76)Ge neutrinoless double beta decay with the CDEX-1B experiment

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Chinese Physics C 2024年第10期48卷 11-22页

作者： Bing-Tao Zhang Jun-Zheng Wang Li-Tao Yang Qian Yue Ke-Jun Kang Yuan-Jing Li Hai-Peng An C.Greeshma Jian-Ping Chang Yun-Huan Chen Jian-Ping Cheng Wen-Han Dai Zhi Deng Chang-Hao Fang Xin-Ping Geng Hui Gong Qiu-Ju Guo Xu-Yuan Guo Li He Sheng-Ming He Jin-Wei Hu Han-Xiong Huang Tu-Chen Huang Hai-Tao Jia Xi Jiang S.Karmakar Hao-Bin Li Jian-Min Li Jin Li Qian-Yun Li Ren-Ming-Jie Li Xue-Qian Li Yu-Lan Li Yi-Fan Liang Bin Liao Fong-Kay Lin Shin-Ted Lin Jia-Xuan liu shu-kui liu Yan-Dong liu Yu liu Yuan-Yuan liu Zhong-Zhi liu Hao Ma Yu-Cai Mao Qi-Yuan Nie Jin-Hua Ning Hui Pan Ning-Chun Qi Jie Ren Xi-Chao Ruan Ze She Manoj Kumar Singh Tian-Xi Sun Chang-Jian Tang Wei-You Tang Yang Tian Guang-Fu Wang Li Wang Qing Wang Yu-Feng Wang Yun-Xiang Wang Henry-Tsz-King Wong Shi-Yong Wu Yu-Cheng Wu Hao-Yang Xing Rui Xu Yin Xu Tao Xue Yu-Lu Yan Nan Yi Chun-Xu Yu Hai-Jun Yu Jian-Feng Yue Ming Zeng Zhi Zeng Feng-Shou Zhang Lei Zhang Zhen-Hua Zhang Zhen-Yu Zhang Kang-Kang Zhao Ming-Gang Zhao Ji-Fang Zhou Zu-Ying Zhou Jing-Jun Zhou Key Laboratory of Particle and Radiation Imaging(Ministry of Education)and Department of Engineering Physics Tsinghua UniversityBeijing 100084 Department of Physics Tsinghua UniversityBeijing 100084 Institute of Physics Academia SinicaTaipei 11529 NUCTECH Company Beijing 100084 YaLong River Hydropower Development Company Chengdu 610051 College of Nuclear Science and Technology Beijing Normal UniversityBeijing 100875 College of Physics Sichuan UniversityChengdu 610065 School of Physics Peking UniversityBeijing 100871 Department of Nuclear Physics China Institute of Atomic EnergyBeijing 102413 Sino-French Institute of Nuclear and Technology Sun Yat-sen UniversityZhuhai 519082 School of Physics Nankai UniversityTianjin 300071 Department of Physics Banaras Hindu UniversityVaranasi 221005 Department of Physics Beijing Normal UniversityBeijing 100875

We operated a p-type point contact high purity germanium(PPCGe)detector(CDEX-1B,1.008 kg)in the China Jinping Underground Laboratory(CJPL)for 500.3 days to search for neutrinoless double beta(0νββ)decay of^(76)Ge.A total of 504.3 kg⋅day effective exposure data was *** anti-coincidence and the multi/single-site event(MSE/SSE)discrimination methods were used to suppress the background in the energy region of interest(ROI,1989–2089 keV for this work)with a factor of 23.A background level of 0.33 counts/(keV⋅kg⋅yr)was *** lower limit on the half life of^(76)Ge 0νββdecay was constrained as T_(1/2)^(0ν)>1.0×10^(23)yr(90%C.L.),corresponding to the upper limits on the effective Majorana neutrino mass:<3.2–7.5 eV.

关键词： neutrinoless double beta decay CDEX point-contact germanium detector ^(76)Ge

Commentary:brain endothelial GSDMD as a novel target for brain disorders associated with BBB damage

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Chinese Journal of Natural Medicines 2024年第7期22卷 580-581页

作者： liu kui PANG Tao State Key Laboratory of Natural Medicines New Drug Screening and Pharmacodynamics Evaluation CenterChina Pharmaceutical UniversityNanjing 210009China

The blood-brain barrier(BBB)is a highly selective and critical interface between the blood and the central nervous system(CNS),essential for maintaining the microenvironment necessary for normal brain function and homeostasis[1].The BBB is primarily formed by brain endothelial cells(bECs),pericytes,and astrocytes,and it operates in concert with microglia/macrophages and neurons[2,3]to constitute the neurovascular unit(Fig.1).Disruption of the BBB or the presence of systemic inflammation can precipitate or exacerbate various CNS pathologies,including Alzheimer’s disease[4],amyotrophic lateral sclerosis[5],Huntington’s disease[6]and multiple sclerosis.

关键词： Brain endothelial cells GSDMD Blood-brain barrier Natural products Neuroinflammation Brain disorders

Identification of anomalous fast bulk events in a p-type point-contact germanium detector

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Nuclear Science and Techniques 2022年第5期33卷 53-67页

作者： Ren-Ming-Jie Li shu-kui liu Shin-Ted Lin Li-Tao Yang Qian Yue Chang-Hao Fang Hai-Tao Jia Xi Jiang Qian-Yun Li Yu liu Yu-Lu Yan Kang-Kang Zhao Lei Zhang Chang-Jian Tang Hao-Yang Xing Jing-Jun Zhu College of Physics Sichuan UniversityChengdu 610065China Key Laboratory of Particle and Radiation Imaging(Ministry of Education)and Department of Engineering Physics Tsinghua UniversityBeijing 100084China

The ultralow detection threshold,ultralow intrinsic background,and excellent energy resolution of ptype point-contact germanium detectors are important for rare-event searches,in particular for the detection of direct dark matter interactions,coherent elastic neutrino-nucleus scattering,and neutrinoless double beta *** bulk events with an extremely fast rise time are observed in the CDEX-1B *** report a method of extracting fast bulk events from bulk events using a pulse shape simulation and reconstructed source experiment *** data and the distribution of X-rays generated by intrinsic radioactivity verified that the fast bulk experienced a single hit near the passivation *** performance of this germanium detector indicates that it is capable of single-hit bulk spatial resolution and thus provides a background removal technique.

关键词： p-type point-contact germanium detector Dark matter Pulse shape analysis Anomalous fast bulk events

An eikonal equation-based earthquake location method by inversion of multiple phase arrivals

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Science China Earth Sciences 2024年第6期67卷 1802-1817页

作者： Gaoyue LAO Dinghui YANG Shaolin liu Guiju DONG Wenshuai WANG kui liu National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China School of Earth Sciences Yunnan UniversityKunming 650091China Department of Mathematical Sciences Tsinghua UniversityBeijing 100084China School of Mathematics and Statistics Ningxia UniversityYinchuan 750021China

The precise determination of earthquake location is the fundamental basis in seismological community,and is crucial for analyzing seismic activity and performing seismic *** arrivals are generally used to practically determine earthquake ***,first-arrival traveltimes are not sensitive to focal ***,they cannot accurately constrain focal *** improve the accuracy,researchers have analyzed the depth phases of earthquake *** traveltimes of depth phases are sensitive to focal depths,and the joint inversion of depth phases and direct phases can be implemented to potentially obtain accurate earthquake ***,researchers can determine earthquake locations in layered *** layered models can only represent the first-order feature of subsurface structures,the advantages of joint inversion are not fully explored if layered models are *** resolve the issue of current joint inversions,we use the traveltimes of three seismic phases to determine earthquake locations in heterogeneous *** three seismic phases used in this study are the first P-,sPg-and *** calculate the traveltimes of the three seismic phases by solving an eikonal equation with an upwind difference scheme and use the traveltimes to determine earthquake *** verify the accuracy of the earthquake location method by the inversion of three seismic phases,we take the 2021 M_(S)6.4 Yangbi,Yunnan earthquake as an example and locate this earthquake using synthetic and real seismic *** tests demonstrate that the eikonal equation-based earthquake location method,which involves the inversion of multiple phase arrivals,can effectively improve earthquake location accuracy.

关键词： Earthquake location Eikonal equation Fast marching method Heterogeneous model

Recovery of cyanophycin granule polypeptide from activated sludge: carbon source dependence and aggregation-induced luminescence characteristics

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Frontiers of Environmental Science & Engineering 2024年第2期18卷 25-34页

作者： kui Zou Hongyuan liu Bo Feng Taiping Qing Peng Zhang College of Environment and Resources Xiangtan UniversityXiangtan 411105China

In the sewage treatment process,facilitating the conversion of pollutants into value-added resources holds great potential for reducing the amount of greenhouse gas emissions and promoting economic *** granule polypeptide(CGP),a recently discovered high value-added biopolymer present in activated sludge,has provided new avenues for the recovery of ***,the mechanisms that regulate CGP synthesis and the characteristics of this biopolymer in activated sludge remain unclear thus *** study investigated the synthesis of CGP,polyhydroxyalkanoates(PHA),and alginate-like exopolysaccharides(ALE)in various microbial aggregates under different carbon sources feeding *** results showed that the CGP yields was superior that of PHA and ALE when subjected to identical carbon source feeding ***,biofilm was more conducive to CGP accumulation than floc *** with glucose and methanol,sodium acetate significantly enriched the CGP synthetase-encoding gene(cphAabundance=~17419),resulting in the highest CGP yield(average 107.1 mg/g MLSS)in both biofilm and floc *** study is the first to reported the characteristic fluorescence of CGP(Ex/Em=~360/450 nm)caused by the aggregated luminescence of arginine on the side ***,this study highlights the potential application of CGP as a fluorescent material and offers insights into CGP recovery from activated sludge in wastewater treatment plants.

关键词： Cyanophycin Polyhydroxyalkanoate Alginate-like exopolysaccharides Bioresource recovery Aggregation-induced luminescence

High‑accuracy measurement of Compton scattering in germanium for dark matter searches

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Nuclear Science and Techniques 2022年第12期33卷 75-87页

作者： Hai‑Tao Jia Shin‑Ted Lin shu‑kui liu Hsin‑Chang Chi Muhammed Deniz Chang‑Hao Fang Peng Gu Xi Jiang Yi‑Ke shu Qian‑Yun Li Yu liu Ren‑Ming‑Jie Li Chen‑Kai Qiao Chang‑Jian Tang Henry Tsz‑King Wong Hao‑Yang Xing Li‑Tao Yang Qian Yue Yu‑Lu Yan Kang‑Kang Zhao Jing‑Jun Zhu College of Physics Sichuan University610065 ChengduChina Department of Physics National Dong Hwa University97401 ShoufengHualienChina Department of Physics Dokuz Eylül University35160 BucaİzmirTurkey Institute of Physics Academia Sinica11529 TaipeiChina Key Laboratory of Particle and Radiation Imaging(Ministry of Education)and Department of Engineering Physics Tsinghua University100084 BeijingChina Institute of Nuclear Science and Technology Sichuan University610065 ChengduChina

Compton scattering with bound electrons contributes to a significant atomic effect in low-momentum transfer,yielding background structures in direct light dark matter searches as well as low-energy rare event *** report the measurement of Compton scattering in low-momentum transfer by implementing a 10-g germanium detector bombarded by a^(137)Cs source with a radioactivity of 8.7 mCi and a scatter photon captured by a cylindrical NaI(Tl)detector.A fully relativistic impulse approximation combined with multi-configuration Dirac–Fock wavefunctions was evaluated,and the scattering function of Geant4 software was replaced by our calculation *** measurements show that the Livermore model with the modified scattering function in Geant4 is in good agreement with the experimental *** is also revealed that atomic many-body effects significantly influence Compton scattering for low-momentum transfer(sub-keV energy transfer).

关键词： Compton scattering experiment Germanium detector Atomic many-body effects Geant4 Dark matter

Viscoacoustic generalized screen propagator in constant-Q model

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Petroleum Science 2024年第4期21卷 2356-2369页

作者： Zhong-kui Dai Jia-Chun You Xing-Guo Huang Wei liu College of Geophysics Chengdu University of Technology College of Instrumentation and Electrical Engineering Jilin University

When seismic waves propagate through the geological formation, there is a significant loss of energy and a decrease in imaging resolution, because of the viscoacoustic properties of subsurface medium. This profoundly impacts seismic wavefield propagation, imaging and interpretation. To accurately image the true structure of subsurface medium, the consensus among geophysicists is to no longer treat subsurface medium as ideal homogeneous medium, but rather to incorporate the viscoacoustic properties of subsurface medium. Based on the generalized screen propagator using conventional acoustic wave equation(acoustic GSP), our developed method introduces viscoacoustic compensation strategy, and derives a one-way wave generalized screen propagator based on time-fractional viscoacoustic wave equation(viscoacoustic GSP). In numerical experiments, we conducted tests on two-dimensional multi-layer model and the Marmousi model. When comparing with the acoustic GSP using the acoustic data, we found that the imaging results of the viscoacoustic GSP using the viscoacoustic data showed a significant attenuation compensation effect, and achieved imaging results for both algorithms were essentially consistent. However, the imaging results of acoustic GSP using viscoacoustic data showed significant attenuation effects, especially for deep subsurface imaging. This indicates that we have proposed an effective method to compensate the attenuated seismic wavefield. Our application on a set of real seismic data demonstrated that the imaging performance of our proposed method in local areas surpassed that of the conventional acoustic GSP. This suggests that our proposed method holds practical value and can more accurately image real subsurface structures while enhancing imaging resolution compared with the conventional acoustic GSP. Finally, with respect to computational efficiency, we gathered statistics on running time to compare our proposed method with conventional Q-RTM, and it is evid

关键词： One-way wave equation Viscoacoustic wave equation Generalized screen propagator Attenuation and dispersion effects

Numerical simulations for radon migration and exhalation behavior during measuring radon exhalation rate with closed-loop method

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Nuclear Science and Techniques 2024年第1期35卷 81-95页

作者： Ming Xia Yong-Jun Ye shu-Yuan liu School of Resources Environment and Safety Engineering University of South ChinaHengyang 421001China Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy University of South ChinaHengyang 421001China

Accurate measurements of the radon exhalation rate help identify and evaluate radon risk regions in the *** these measurement methods,the closed-loop method is frequently ***,traditional experiments are insufficient or cannot analyze the radon migration and exhalation patterns at the gas–solid interface in the accumulation *** CFD-based technique was applied to predict the radon concentration distribution in a limited space,allowing radon accumulation and exhalation inside the chamber intuitively and *** this study,three radon exhalation rates were defined,and two structural ventilation tubes were designed for the *** consistency of the simulated results with the variation in the radon exhalation rate in a previous experiment or analytical solution was *** effects of the vent tube structure and flow rate on the radon uniformity in the chamber;permeability,insertion depth,and flow rate on the radon exhalation rate and the effective diffusion coefficient on back-diffusion were *** on the results,increasing the inser-tion depth from 1 to 5 cm decreased the effective decay constant by 19.55%,whereas the curve-fitted radon exhalation rate decreased(lower than the initial value)as the deviation from the initial value increased by approximately 7%.Increasing the effective diffusion coefficient from 2.77×10^(-7) to 7.77×10^(-6) m^(2) s^(-1) made the deviation expand from 2.14 to 15.96%.The conclusion is that an increased insertion depth helps reduce leakage in the chamber,subject to notable back-diffusion,and that the closed-loop method is reasonably used for porous media with a low effective diffusion coefficient in view of the back-diffusion *** CFD-based simulation is expected to provide guidance for the optimization of the radon exhalation rate measurement method and,thus,the accurate measurement of the radon exhalation rate.

关键词： Radon exhalation Numerical simulation Accumulation chamber

Multidomain Hybrid Direct DG and Central Difference Methods for Viscous Terms in Hyperbolic-Parabolic Equations

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NUMERICAL MATHEMATICS-THEORY METHODS AND APPLICATIONS 2024年第1期17卷 1-36页

作者： Yuan, Weixiong liu, Tiegang Zhang, Bin Cao, kui Wang, Kun Beihang Univ LMIB Beijing 100191 Peoples R China Beihang Univ Sch Math Sci Beijing 100191 Peoples R China

A class of multidomain hybrid methods of direct discontinuous Galerkin (DDG) methods and central difference (CD) schemes for the viscous terms is proposed in this paper. Both conservative and nonconservative coupling modes are discussed. To treat the shock wave, the nonconservative coupling mode automatically switch to conservative coupling mode to preserve the conservative property when discontinuities pass through the artificial interface. To maintain the accuracy of the hybrid methods, the Lagrange interpolation polynomials and their derivatives are reconstructed to handle the coupling cells in the DDG subdomain, while the values of ghost points for the CD subdomain are calculated by the approximate polynomials from the DDG methods. The linear stabilities of these methods are demonstrated in detail through von-Neumann analysis. The multidomain hybrid DDG and CD methods are then extended to one- and two-dimensional hyperbolic-parabolic equations. Numerical results validate that the multidomain hybrid methods are high-order accurate in the smooth regions, robust for viscous shock simulations and capable to save computational cost.

关键词： Direct discontinuous Galerkin central difference schemes multidomain hybrid methods viscous terms hyperbolic-parabolic equations FINITE-ELEMENT-METHOD DISCONTINUOUS GALERKIN METHOD NAVIER-STOKES EQUATIONS CONSERVATION-LAWS EFFICIENT IMPLEMENTATION DG/FV METHODS CONVERGENCE RATE ORDER SCHEMES APPROXIMATIONS