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In-beam gamma rays of CSNS Back-n characterized by black resonance filter

NUCLEAR SCIENCE AND TECHNIQUES 2024年第10期35卷 1-12页

作者： Wang, Jin-Cheng Ren, Jie Jiang, Wei Ruan, Xi-Chao Liu, Ying-Yi Yang, Hao-Lan Xu, Kuo-Zhi Pan, Xin-Yi Sun, Qi Bao, Jie Huang, Han-Xiong Bai, Hao-Fan Bai, Jiang-Bo Cao, Ping Chen, Qi-Ping Chen, Yong-Hao Duan, Wen-Hao Fan, An-Chuan Fan, Rui-Rui feng, chang-qing Gu, Min-Hao Han, chang-Cai Han, Zi-Jie He, Guo-Zhu He, Yong-Cheng Hong, Yang Hu, Yi-Wei Jiang, Zhi-Jie Kang, Ling Lan, chang-Lin Li, Bo Li, feng Li, Qiang Li, Xiao Li, Yang Liu, Jie Liu, Rong Liu, Shu-Bin Liu, Yi-Na Luan, Guang-Yuan Ning, chang-Jun Qiu, Yi-Jia Ren, Wen-Kai Ren, Zhi-Zhou Song, Zhao-Hui Sun, Kang Tan, Zhi-Xin Tang, Jing-Yu Tang, Sheng-Da Wang, Li-Jiao Wang, Peng-Cheng Wang, Zhao-Hui Wen, Zhong-Wei Wu, Xiao-Guang Wu, Xuan Wu, Ze-Peng Xia, Cong Xie, Li-Kun Yi, Han Yu, Tao Yu, Yong-Ji Zhang, Guo-Hui Zhang, Hang-chang Zhang, Qi-Wei Zhang, Xian-Peng Zhang, Yu-Liang Zhang, Zhi-Yong Zhao, Mao-Yuan Zhou, Zhi-Hao Zhu, Ke-Jun Zou, Chong China Inst Atom Energy Key Lab Nucl Data Beijing 102413 Peoples R China Chinese Acad Sci Inst High Energy Phys Beijing 100049 Peoples R China Spallat Neutron Source Sci Ctr Dongguan 523803 Peoples R China Chinese Acad Sci Inst High Energy Phys State Key Lab Particle Detect & Elect Beijing 100049 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China Peking Univ Sch Phys State Key Lab Nucl Phys & Technol Beijing 100871 Peoples R China Fudan Univ Inst Modern Phys Shanghai 200433 Peoples R China Univ Sci & Technol China State Key Lab Particle Detect & Elect Hefei 230026 Peoples R China Univ Sci & Technol China Sch Nucl Sci & Technol Hefei 230026 Peoples R China Univ Sci & Technol China Dept Modern Phys Hefei 230026 Peoples R China China Acad Engn Phys Inst Nucl Phys & Chem Mianyang 621900 Peoples R China Univ Sci & Technol China USTC Archaeometry Lab Hefei 230026 Peoples R China Northwest Inst Nucl Technol Xian 710024 Peoples R China Lanzhou Univ Sch Nucl Sci & Technol Lanzhou 730000 Peoples R China Univ Sci & Technol China Inst Adv Technol Hefei 230027 Peoples R China

The back-streaming white-neutron beamline (Back-n) of the China Spallation Neutron Source is an essential neutron- research platform built for the study of nuclear data, neutron physics, and neutron applications. Many types of cross-sectional neutron-reaction measurements have been performed at Back-n since early 2018. These measurements have shown that a significant number of gamma rays can be transmitted to the experimental stations of Back-n along with the neutron beam. These gamma rays, commonly referred to as in-beam gamma rays, can induce a non-negligible experimental background in neutron-reaction measurements. Studying the characteristics of in-beam gamma rays is important for understanding the experimental background. However, measuring in-beam gamma rays is challenging because most gamma-ray detectors are sensitive to neutrons; thus, discriminating between neutron-induced signals and those from in-beam gamma rays is difficult. In this study, we propose the use of the black resonance filter method and a CeBr3 scintillation detector to measure the characteristics of the in-beam gamma rays of Back-n. Four types of black resonance filters, Ta-181, Co-59, Ag-nat, and Cd-nat, were used in this measurement. The time-of-flight (TOF) technique was used to select the detector signals remaining in the absorption region of the TOF spectra, which were mainly induced by in-beam gamma rays. The energy distribution and flux of the in-beam gamma rays of Back-n were determined by analyzing the deposited energy spectra of the CeBr3 scintillation detector and using Monte Carlo simulations. Based on the results of this study, the background contributions from in-beam gamma rays in neutron-reaction measurements at Back-n can be reasonably evaluated, which is beneficial for enhancing both the experimental methodology and data analysis.

关键词： In-beam gamma rays Back-n Black filter resonance technique In-beam gamma rays Back-n CeBr3 scintillator Black filter resonance technique C6D6 DETECTOR SYSTEM LINE

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Recent progress on the synthesis of defective UiO-66 for thermal catalysis

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Nano Research 2024年第10期17卷 8653-8670页

作者： qing feng Caoyu Yang Lin chang Guodong Li Zhiyong Tang CAS Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China School of Nanoscience and Engineering University of Chinese Academy of SciencesBeijing 100049China

Zirconium terephthalate UiO-66 has aroused great interest in catalysis since it exhibits significant flexibility and compatibility for accommodating a high number of defects as well as exceptional thermal and chemical *** now,many works have focused on the modulations of the Zr6-oxo clusters in UiO-66 in terms of diverse synthesis,advanced characterizations,and their catalytic *** achieve high catalytic efficiency,it is still highly desired for rationally constructing and modulating the Zr6-oxo clusters with exposed catalytic sites and diverse microenvironments for advanced *** this review,we provide a comprehensive summary of recent progress on the synthesis of defective UiO-66,qualitative and quantitative characterizations,as well as a logical overview of heterogeneous catalytic applications over the past few ***,the outlooks for the research paradigm of defective UiO-66 are discussed.

关键词： defective UiO-66 de novo synthesis post-synthetic treatment characterization thermal catalysis

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Screening and degradation characteristics of a tylosin-degrading strain

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Journal of Integrative Agriculture 2020年第4期19卷 1127-1136页

作者： feng chang-qing CHENG Deng-miao feng Yao QI Wei-ning JIA Zhen-hu Louise WEAVER LIU Yuan-wang LI Zhao-jun College of Life Science Shanxi Normal UniversityLinfen 041004P.R.China Key Laboratory of Plant Nutrition and Fertilizer Ministry of Agriculture and Rural Affairs/China-New Zealand Joint Laboratory for Soil Molecular EcologyInstitute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081P.R.China Institute of Environmental and Science Research Ltd. Christchurch Science CentreChristchurch 8041New Zealand

Antibiotics residues have been accumulating in the environment day by day due to overuse of *** antibiotic residues,such as tylosin(TYL),can cause serious environmental problems,which makes it important to eliminate TYL from the *** is important to eliminate TYL from the *** this study,a strain was isolated and purified from fermentation by-product that came from a TYL production *** TYL degrading strain was identified by its morphology,physiological and biochemical reactions and sequencing the PCR-amplified fragments of its 16 S r DNAcoding *** temperature,shaking speed,initial TYL concentration,p H and inoculum sizes were investigated under simulated conditions by using single factor *** results showed that TYL2,a high efficient strain was isolated and was identified as Brevibacillus *** degradation rate of TYL by this strain could reach to 75%with an initial concentration of 25 mg L^-1 within 7 days under conditions of 7%***(v/v,2×108 CFU m L^-1)at p H 7.0 and at 35°*** is interesting that this strain has a very strong ability to degrade the TYL in natural sewage with the degradation rate of 65%within 7 *** result could be helpful for the degradation of TYL and provide guidance for the degradation of other antibiotics.

关键词： antibiotics tylosin screening degrading strain B.borstelensis degradation characteristic

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Generic Modeling and Control Framework for Power Systems Dominated by Power Converters Connected Through a Passive Transmission and Distribution Grid

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 292-301页

作者： qing-chang Zhong Marcio Stefanello Department of Electrical and Computer Engineering Illinois Institute of TechnologyChicagoIL 60616USA Syndem LLC USA.M.Stefanello is with the Fundacao Universidade Federal do Pampa at AlegreteRS97546-550Brazil

In this paper,a compact mathematical model having an elegant structure,together with a generic control framework,are proposed for generic power systems dominated by power converters that are interconnected through a passive transmission and distribution(T&D)grid,by adopting the port-Hamiltonian(pH)systems theory and the fundamental circuit *** models of generic T&D lines are developed and then the model of a generic T&D grid is *** the proposed control framework,the controlled converters are proven to be passive and Input-to-State Stable(ISS).The compact mathematical model is scalable and can be applied to power systems with multiple power electronic converters with generic passive controllers,passive local loads,and different types of passive T&D lines connected in a meshed configuration without self-loops,so it is very ***,the resulting power system is proven to be ISS as *** analysis is carried out without assumptions on constant frequency/voltage,constant loads,and/or lossless networks,except the need of passivity for all parts involved,and without using the Clarke/Park transformations or the graph *** simplify the presentation,three-phase balanced systems are adopted but the results can be easily adapted for single-phase or unbalanced three-phase systems.

关键词： Input-to-State Stable(ISS) passivity,portHamiltonian(pH)systems Power electronic converters dominated power systems Synchronized and Democratized(SYNDEM)grid architecture

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Properties of collective flow and pion production in intermediate-energy heavy-ion collisions with a relativistic quantum molecular dynamics model

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Nuclear Science and Techniques 2024年第1期35卷 155-169页

作者： Si-Na Wei Zhao-qing feng School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510640China

The relativistic mean-field approach was implemented in the Lanzhou quantum molecular dynamics transport model(***). Using the ***, the properties of collective flow and pion production were investigated systematically for nuclear reactions with various isospin asymmetries. The directed and elliptic flows of the *** are able to describe the experimental data of STAR Collaboration. The directed flow difference between free neutrons and protons was associated with the stiffness of the symmetry energy, that is, a softer symmetry energy led to a larger flow difference. For various collision energies, the ratio between the π^(-) and π^(+) yields increased with a decrease in the slope parameter of the symmetry energy. When the collision energy was 270 MeV/nucleon, the single ratio of the pion transverse momentum spectra also increased with decreasing slope parameter of the symmetry energy in both nearly symmetric and neutron-rich ***, it is difficult to constrain the stiffness of the symmetry energy with the double ratio because of the lack of threshold energy correction on the pion production.

关键词： Heavy-ion collision Collective flow Pion production Symmetry energy Relativistic mean field

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Comprehensive evaluations of heat transfer performance with conjugate heat dissipation effect in high-speed rotating free-disk modeling of aero-engines

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Fundamental Research 2024年第3期4卷 611-623页

作者： Aqiang Lin Gaowen Liu Ran chang Yan Chen qing feng School of Power and Energy Northwestern Polytechnical UniversityXi'an 710129China Shaanxi Key Laboratory of Thermal Science in Aero-engine System Northwestern Polytechnical UniversityXi'an 710072China Research&Development Institute of Northwester

Thermal boundary conditions of the turbine disk cavity system are of great importance in the design of secondary air systems in *** study aims to investigate the complex heat transfer mechanisms of a rotating turbine disk under high-speed conditions.A high-speed rotating free-disk model with Dorfman empirical solutions is developed to evaluate the heat transfer performance considering various ***,the influence of compressibility,variable properties,and heat dissipation is determined using theoretical and numerical *** particular,a novel combined solution method is proposed to simplify the complex heat transfer *** results indicate that the heat transfer performance of a free disk is primarily influenced by the rotating Mach number,rotating Reynolds number,Rossby number,and wall temperature *** heat transfer temperature and Nusselt number of the free disk are strongly correlated with the rotating Mach number and rotating Reynolds *** reveals that heat dissipation is a critical factor affecting the accurate evaluation of the heat transfer performance of the turbine ***,the combined solution method can serve as a reference for future investigations of flow and heat transfer in high-speed rotating turbine disk cavity systems in aero-engines.

关键词： Aero-engine Rotating turbine disk Dimensional analysis Compressibility Heat dissipation Dorfman empirical solution

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Trace elements in magmatic and hydrothermal quartz:Implications on the genesis of the Xingluokeng Tungsten Deposit,South China

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Acta Geochimica 2024年第3期43卷 441-458页

作者： qing-qing Zhang You-Wei Chen Jian-feng Gao State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China University of Chinese Academy of Sciences Beijing 100049China

The Xingluokeng deposit is the largest gran-ite-related tungsten deposit within the Wuyi metallogenic belt in South *** Xingluokeng intrusion primarily consists of porphyritic biotite granite,biotite granite,andfine-grained *** deposit is represented by veinlet-disseminated mineralization with K-feldspathization and biotitization,alongside quartz-vein mineralization with gre-isenization and *** study investigates in-situ analyses of quartz compositions from both the intrusion and hydrothermal veinlets and *** element correlations indicate that trivalent Al^(3+)and Fe^(3+)replace Si^(4+)within the quartz lattice,with monovalent cations(such as Li^(+),Na^(+),and K^(+))primarily serving as charge *** Ge/Al ratios(<0.013)of quartz from granites suggest a mag-matic *** low Al/Ti and Ge/Ti ratios,accompanied by high Ti contents in quartz,suggest that the porphyritic biotite granite and biotite granite are characterized by rela-tively low levels of differentiation and high crystallization *** contrast,thefine-grained granite exhibits a higher degree of fractionation,lower crystallization tem-peratures,and a closer association with tungsten *** contents in quartz from quartz veins indicate Qz-Ⅰformed at temperatures above 400°C,while Qz-Ⅱto Qz-Ⅴformed at temperatures below 350°*** in different generations of quartz,as indicated by Al content and(Al+Fe)/(Li+Na+K)ratio,suggest that Qz-Ⅰprecipi-tated from a less acidicfluid with a stable pH,whereas Qz-Ⅱto Qz-Ⅴoriginated from a more acidicfluid with notable pH ***,alkaline alteration and acidic alteration supplied the essential Ca and Fe for the precipita-tion of scheelite and wolframite,respectively,highlighting a critical mechanism in tungsten mineralization at the Xin-gluokeng deposit.

关键词： Quartz Xingluokeng Tungsten deposit Trace elements South China

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Improvement for creep strength of a second-generation single crystal superalloy by design of heat treatments

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Rare Metals 2024年第1期43卷 342-350页

作者： Wan-Shun Xia Xin-Bao Zhao Jia-Chen Xu Quan-Zhao Yue qing-qing Ding Huan-chang Duan Yue-feng Gu Hong-Bin Bei Ze Zhang Institute of Superalloys Science and Technology School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China State Key Laboratory of Silicon and Advanced Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China

Design of heat treatments is related to the key technology for development of nickel-based single crystal superalloys(Ni-SXs). Based on the full understanding of the solidification characteristics, this work applies optimization design of heat treatments for a second-generation Ni-SX. Microstructure evolution and creep properties are compared in the material under conventional/standard(Std.) and optimized(Opt.) treatments. For the Std. sample,strong dendritic segregations determine inconsistent microstructure evolution in the dendritic(D) and interdendritic region(ID), while the latter serves as weak area to have the prior microcrack initiation, damaging overall performance of the alloy. The Opt. treatment applies higher homogenization temperature, leading to overall reduced segregations, while not inducing incipient melting. A lower temperature of first-step ageing is used to lower the size ofγ'particles. These help to form the more uniform microstructure in dendritic and interdendritic region and relieve the inconsistent microstructure evolution. The balanced local strength makes ID no longer as the weak area,thus restricting microcrack initiation. Great improvement of high temperature and low stress property is obtained by this progress, leading to the pronounced increase of creep rupture life under 1100 °C/140 MPa.

关键词： Single crystal superalloy Heat treatment Segregation Solidification Creep property

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Monocyte to High-density Lipoprotein Cholesterol Ratio as a Predictor of Nonalcoholic Fatty Liver Disease in Childhood Obesity

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Current Medical Science 2024年第4期44卷 692-697页

作者： Jun-feng ZHANG feng-qing CAI Xiu-cai ZHANG qing YE Department of Laboratory Medicine Children’s HospitalZhejiang University School of MedicineNational Clinical Research Center for Child HealthHangzhou310052China

Objective Inflammation is involved in the development and progression of nonalcoholic fatty liver disease(NAFLD).The monocyte to high-density lipoprotein cholesterol ratio(MHR)has emerged as a marker for various inflammation-related *** aim of the present study was to investigate the association between the MHR and NAFLD in a population with childhood *** Based on hepatic ultrasound,a total of 504 children with obesity(357 with NAFLD and 147 without NAFLD)were included in the *** correlation between the MHR and NAFLD risk factors was assessed by Pearson’s and Spearman’s *** stepwise logistic regression analyses were conducted to explore the association between the MHR and the risk of *** The MHR in patients with NAFLD was significantly greater than that in patients without NAFLD[0.52(0.44-0.67)versus 0.44(0.34-0.57),P<0.001].Multivariate stepwise logistic regression analysis demonstrated that the MHR[odds ratio(OR):1.033,95%confidence interval(CI):1.015-1.051;P<0.001]was an independent predictor of NAFLD in childhood obesity patients,as were age(OR:1.205,95%CI:1.059-1.371;P=0.005],waist circumference[OR:1.037,95%CI:1.008-1.067;P=0.012],and alanine transaminase[OR:1.067,95%CI:1.045-1.089;P<0.001].Additionally,MHR quartiles showed a significant positive association with the incidence of NAFLD after adjusting for potential confounding *** The present study showed that the MHR may serve as an available and useful indicator of NAFLD in individuals with childhood obesity.

关键词： nonalcoholic fatty liver disease obesity monocyte-to-high-density lipoprotein ratio marker

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Improving the Short-Range Precipitation Forecast of Numerical Weather Prediction through a Deep Learning-Based Mask Approach

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Advances in Atmospheric Sciences 2024年第8期41卷 1601-1613页

作者： Jiaqi ZHENG qing LING Jia LI Yerong feng School of Computer Science and Engineering/Guangdong Provincial Key Laboratory of Computational Science Sun Yat-Sen UniversityGuangzhou 510006China School of Mathematics Sun Yat-Sen UniversityGuangzhou 510275China Guangzhou Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction Guangzhou 510641China Shenzhen Institute of Meteorological Innovation Shenzhen 518038China

Due to various technical issues,existing numerical weather prediction(NWP)models often perform poorly at forecasting rainfall in the first several *** correct the bias of an NWP model and improve the accuracy of short-range precipitation forecasting,we propose a deep learning-based approach called UNet Mask,which combines NWP forecasts with the output of a convolutional neural network called *** UNet Mask involves training the UNet on historical data from the NWP model and gridded rainfall observations for 6-hour precipitation *** overlap of the UNet output and the NWP forecasts at the same rainfall threshold yields a *** UNet Mask blends the UNet output and the NWP forecasts by taking the maximum between them and passing through the mask,which provides the corrected 6-hour rainfall *** evaluated UNet Mask on a test set and in real-time *** results showed that UNet Mask outperforms the NWP model in 6-hour precipitation prediction by reducing the FAR and improving CSI *** tests also showed that different small rainfall thresholds applied to the UNet and the NWP model have different effects on UNet Mask's forecast *** study shows that UNet Mask is a promising approach for improving rainfall forecasting of NWP models.

关键词： deep learning numerical weather prediction(NWP) 6-hour quantitative precipitation forecast

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