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Prospects of detecting the reactor v_(e)-Ar coherent elastic scattering with a low-threshold dual-phase argon time projection chamber at Taishan

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Radiation Detection Technology and Methods 2021年第2期5卷 297-306页

作者： Yu-Ting Wei meng-yun guan Jin-Chang Liu Ze-Yuan Yu Chang-Gen Yang Cong Guo Wei-Xing Xiong You-Yu Gan Qin Zhao Jia-Jun Li Institute of High Energy Physics CASBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China North China Electric Power University Beijing 100096China

Background We propose to measure the coherent elastic neutrino-nucleus scattering(CEvNS)using a dual-phase liquid argon time projection chamber(TPC)with 200 kg fiducial *** detector is expected to be adjacent to the JUNOTAO experiment and to be about 35 m from a reactor core with 4.6 GW thermal power at *** antineutrino flux is approximately 6×10^(12)cm^(−1)s^(−1) at this location,leading to more than 11,000 coherent scattering events per day in the fiducial *** The nuclear recoil energies concentrate in the sub-keV region,corresponding to less than ten ionization electrons in the liquid *** key question is how to veto and shield the background in the hall where the vertical overburden is about 5 *** what is the signal count rate and the background *** addition,what physical parameters can be measured what is the *** We used the Geant4 to simulate the backgrounds from cosmic ray muons and ambient radioactivity *** a veto and shielding design is *** a χ^(2) function is constructed and the sensitivity calculate package built to calculate the sensitivity of physical *** The detection of several ionization electrons can be achieved in the dual-phase TPC due to the large amplification in the gas *** a feasible detection threshold of four ionization electrons,the signal rate is 955 per *** detector is designed to be shielded well from cosmogenic backgrounds and ambient radioactivities to reach a 16%background-tosignal ratio in the energy region of *** the large CEvNS sample,the expected sensitivity of measuring the weak mixing angle sin^(2)θ_(w),and of limiting the neutrino magnetic moment are *** addition,a synergy between the reactor antineutrino CEvNS experiment and the dark matter experiment is foreseen.

关键词： Coherent elastic neutrino-nucleus scattering Dual-phase argon TPC Reactor antineutrinos

Calibration of liquid argon detector with ^(83m)Kr and ^(22)Na in different drift fields

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Radiation Detection Technology and Methods 2020年第2期4卷 147-152页

作者： Wei-Xing Xiong meng-yun guan Chang-Gen Yang Peng Zhang Jin-Chang Liu Cong Guo Yu-Ting Wei You-Yu Gan Qing Zhao Jia-Jun Li Institute of High Energy Physics Beijing 100049China University of Chinese Academy of Sciences Beijing 100049China North China Electric Power University Beijing 100096China

Introduction Liquid noble gases are widely used as targets in low background search experiments,particularly in direct dark matter search experiments.83mKr is an excellent low-energy internal calibration source for future larger liquid noble gas *** To calibrate liquid argon detector with 83mKr in different drift fields and to study the correlation between light yield and drift *** A dual-phase LAr prototype detector was designed to study the 83mKr responses in liquid argon.83mKr atoms are produced through the decay of 83Rb and introduced into the LAr detector through the circulating purification *** We report that the light yield reaches 7.26±0.02 pe/keV for 41.5 keV from 83mKr and 7.66±0.01 pe/keV for 511 keV from 22Na,as a *** stopping the fill,the rate decays of 83mKr are with a fitted half-life of 1.83±0.11 h,which is consistent with the reported value of 1.83±0.02 *** light yield that varies with the drift electric field from 0 to 200 V/cm has also been reported.

关键词： Time projection chamber Noble liquid detectors Light yield Liquid argon

Effect of Mn addition on microstructure and mechanical properties of GX40CrNiSi25-12 austenitic heat resistant steel

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China Foundry 2024年第3期21卷 205-212页

作者： guan-yu Jiang meng-wu Wu Xiao-guang Yang Hui Wang Yu-yuan Zhu Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China Hubei Longzhong Laboratory Xiangyang 441000HubeiChina Wescast Industries(China)Co. Ltd.Wuhan 430100China

Three types of steels were designed on the basis of GX40CrNiSi25-12 austenitic heat resistant steel by adding different Mn contents(2wt.%,6wt.%,and 12wt.%).Thermodynamic calculation,microstructure characterization and mechanical property tests were conducted to investigate the effect of Mn addition on the microstructure and mechanical properties of the austenitic heat resistant *** show that the matrix structure in all the three types of steels at room temperature is completely *** NbC and M_(23)C_(6)precipitate at grain boundaries of austenite *** the increase of Mn content,the number of carbides increases and their distribution becomes more *** the Mn content increases from 1.99%to 12.06%,the ultimate tensile strength,yield strength and elongation increase by 14.6%,8.0%and 46.3%,*** improvement of the mechanical properties of austenitic steels can be explained by utilizing classic theories of alloy strengthening,including solid solution strengthening,precipitation strengthening,and grain *** increase in alloy strength can be attributed to solid solution strengthening and precipitation strengthening caused by the addition of *** improvement of the plasticity of austenitic steels can be explained from two aspects:grain refinement and homogenization of precipitated phases.

关键词： austenitic heat resistant steel manganese microstructure mechanical properties

Effect of slag composition on kinetic behavior of deep deoxidation of 5 wt.% Si high-silicon austenitic stainless steel

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Journal of Iron and Steel Research International 2024年第8期31卷 1873-1885页

作者： guan-xiong Dou Han-jie Guo Jing Guo Xue-cheng Peng Qing-yun Chen School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing 100083China Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials Beijing 100083China

Based on a thermodynamic study of 5 wt.%Si high-silicon austenitic stainless steel(SS-5Si)smelting using CaF_(2)-CaO-Al_(2)0_(3)-Mg-Si0_(2) slag to obtain a low oxygen content of less than 10×10^(-4) wt.%,a kinetic mass transfer model for deep deoxidation was established through laboratory studies,and the effects of slag components and temperature on deoxidation during the slag-steel reaction process of sS-5Si were systematically *** experimental data verified the accuracy of the model *** results showed that the final oxygen content in the steel at 1873 K was mainly controlled by the oxygen content derived from the activity of SiO_(2) regulated by the[Si]-[O]equilibrium reaction in the slag system;in particular,when the slag basicity R(R=w(CaO)/w(SiO2),where w(CaO)and w(SiO_(2))are the contents of CaO and SiO_(2) in the slag,respectively)is 3,the Al2O3 content in the slag needs to be less than 2.7%.The mass transfer rate equation for the kinetics of the deoxidation reaction revealed that the mass transfer of oxygen in the liquid metal is the rate-controlling step under different slag conditions at 1873 K,and the oxygen transfer coefficient ko.m increases with increasing the slag basicity from 4.0×10^(-6)m s^(-1)(R=1)to 4.3×10^(-5) m s^(-1)(R=3).ko.m values at R=2 and R=3 are almost the same,indicating that high slag basicity has little *** integral of the mass transfer rate equation for the deoxidation reaction of SS-5Si under different slag conditions is *** total oxygen content of the molten steel decreases with increasing basicity from an initial content of 22×10^(-4) to 3.2×10^(-4) wt.%(R=3),consistent with the change in ko.m with slag *** R=2,the slag-steel reaction takes 15 min to reach equilibrium(w[O]=5.5×10^(-4) wt.%),whereas at R=3,the slag-steel reaction takes 30 min to reach equilibrium(w[0]=3.2×10^(-4) wt.%).Considering the depth of deoxidation and reaction time of SS-5Si smelting,it is recommended the slag b

关键词： Slag-steel reaction Kinetics Rate-controlling step Deep deoxidation Transfer coefficient

Characterization of sand convective motions at a vertical wall subjected to long-term cyclic loading

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Fundamental Research 2024年第2期4卷 334-343页

作者： Dawei guan Jialong Li Yee-meng Chiew Jisheng Zhang Key Laboratory of Ministry of Education for Coastal Disaster and Protection Hohai UniversityNanjing 210024China College of Harbour Coastal and Offshore EngineeringHohai UniversityNanjing 210024China Shanghai Investigation Design and Research Institute Co.LtdShanghai 200335China School of Civil and Environmental Engineering Nanyang Technological UniversitySingapore 639798Singapore

By conducting a two-dimensional experimental study,this paper aims to enhance the understanding of the mechanism of sand convective motions in the vicinity of a wall subjected to long-term cyclic lateral *** experimental tests were conducted in a rectangular sandbox with a transparent front-wall,through which the process of sand particle motions could be recorded by using a high-resolution digital *** images were processed with a high time-resolved PIV(Particle Image Velocimetry)*** on the experimental data,this work(1)presents the sand flow field in the convective zones;(2)provides means to describe the convection mechanism;(3)proposes the relationships between the loading conditions and dimensions of the region with intense sand movement;and(4)elaborates the similarity of the sand flow velocity structure within the sand convective zones.

关键词： Vibration Soil/structure interaction Deformation Particle image velocimetry Laboratory tests

General radical difluoromethylation using difluoroacetic anhydride via photoredox catalysis

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Science China Chemistry 2024年第8期67卷 2637-2646页

作者： meng He Yankai Yang Heng Zhang Zhipeng guan Zhi-Bing Dong Hong Yi Aiwen Lei School of Chemistry and Environmental Engineering Wuhan Institute of TechnologyWuhan 430205China College of Chemistry and Molecular Sciences and Institute for Advanced Studies(IAS) Wuhan UniversityWuhan 430072China

CF_(2)H-containing molecules play pivotal roles in diverse fields from medicinal chemistry to materials science. However, the application of existing CF_(2)H reagents as a source of CF_(2)H radical is limited by their reactivity and preparation. Herein, we develop a simple and general visible-light-catalyzed radical difluoromethylation reaction of alkenes, dienes, and heteroaromatics using commercially available, easy-to-handle, and low-cost difluoroacetic anhydride as the CF_(2)H reagent. This scalable protocol enables the convenient synthesis of a range of CF_(2)H-containing compounds under mild conditions, exhibiting a broad substrate scope and functional group tolerance. Potential applications are further demonstrated by gram-scale synthesis, sunlight experiments, derivatization experiments as well as the synthesis of bioactive molecules.

关键词： radical difluoromethylation alkenes/dienes/heteroaromatics difluoroacetic anhydride photoredox

Reversal of complete atrioventricular block in dialysis patients following parathyroidectomy:A case report

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World Journal of Clinical Cases 2024年第7期12卷 1313-1319页

作者： Shan-Shan Xu Li-Hai Hao Yan-meng guan Hemodialysis Center Weifang People’s HospitalWeifang 261041Shandong ProvinceChina

BACKGROUND Refractory secondary hyperparathyroidism(SHPT)is a common complication observed in patients with end-stage renal disease and can result in ectopic *** calcification involving the heart valves and the conduction system can easily lead to arrhythmias,including atrioventricular *** case report describes a maintenance hemodialysis patient with refractory SHPT resulting in a complete atrioventricular block(CAVB),which was eventually reversed to a first-degree atrioventricular *** SUMMARY We present the case of a 31-year-old Asian female who was receiving maintenance hemodialysis because of lupus *** developed SHPT,and an electrocardiogram revealed a first-degree atrioventricular ***,she underwent parathyroidectomy(PTX)with ***,a few years later,she developed SHPT again,and an electrocardiogram revealed a CAVB.A few years after the second PTX surgery,the calcification of the left atrium and left ventricle improved,and her CAVB was *** This case revealed that metastatic cardiac calcification can result in complete atrioventricular *** parathyroid surgery,calcification of the cardiac conduction system improved,leading to reversal of the atrioventricular *** is important for dialysis patients to optimize intact parathyroid hormone therapy and pay attention to calcification metastasis.

关键词： Secondary hyperparathyroidism Ectopic calcification Atrioventricular block Reversal Case report

The reservoir characteristics and their controlling factors of the sublacustrine fan in the Paleogene Dongying Formation, Bohai Sea,China

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Journal of Palaeogeography 2024年第1期13卷 127-148页

作者： Xiao-Jun Pang guan-Min Wang meng Zhao Qing-Bin Wang Xue-Fang Zhang School of Geosciences China University of Petroleum(East China)QingdaoShandong 266580China Tianjin Branch of China National Offshore Oil Corporation Limited Tianjin 300459China

Sublacustrine fan is an important element in continental lacustrine basins and is significant for reservoir exploration. Oil and gas resources have been found in the sublacustrine fan sandstone reservoirs of the Paleogene Dongying Formation in the Bohai Sea. In this study, the characteristics of the sublacustrine fan reservoirs and the controlling factors are studied using information from logging, cores, physical properties,casting thin sections, X-ray diffraction of clay minerals, vitrinite reflectance, rock pyrolysis, manometry data,and 3D seismic data. The sublacustrine fans of the Dongying Formation in the LD10, QHD34, and BZ21 structures show high-quality reservoirs with porosity >15 % and permeability >5 m D. The main controlling factors of the high-quality reservoirs are attributed to the favorable sedimentary facies type and negligible compaction,and cementation, substantial dissolution of K-feldspar, overpressure, and the development of faults and fractures. A high-quality sublacustrine fan reservoir model has been established to explain how these factors affected the physical properties. The favorable targets for oil and gas exploration in the Dongying Formation of Bohai Sea include undercompacted sandy debris flow reservoirs showing the dissolution of K-feldspar, and the reservoirs which are connected to the source rocks by faults. This study provides insights to establish the relationship between sedimentology, diagenesis and reservoir quality. The results of this study are significant for the exploration and development of the sublacustrine fan sandstone reservoirs in the Bohai Sea and analogous sandstone reservoirs elsewhere.

关键词： Sublacustrine fan High-quality reservoir Dissolution Overpressure Fault Bohai Sea

Further study on the genesis of lamellar calcite veins in lacustrine black shale--A case study of Paleogene in Dongying Depression, China

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Petroleum Science 2024年第3期21卷 1508-1523页

作者： guan-Min Wang yun-Jiao Zhang Zi-Yuan Yin Rui Zhu Zhi-Yao Hou Yu Bai School of Geosciences China University of Petroleum(East China)Qingdao266580ShandongChina

Lamellar calcite veins are prevalent in carbonate-rich,lacustrine dark *** formation mechanisms of these veins have been extensively debated,focusing on factors such as timing,depth,material source,and driving *** paper examines dark lacustrine shale lamellar calcite veins in the Paleogene strata of Dongying Depression,using various analytical techniques:petrography,isotope geochemistry,cathodoluminescence,inclusion thermometry,and electron probe *** distinct types of calcite veins have been identified:granular calcite veins and sparry calcite *** two types differ significantly in color,grain structure,morphology,and *** further investigation,it was observed that vein generation occurred from the shallow burial period to the maturation of organic matter,with a transition from granular calcite veins to sparry calcite *** granular calcite veins exhibit characteristics associated with the shallow burial period,including plastically deformed laminae and veins,the development of strawberry pyrite,the absence of oil and gas,weak fractionation in oxygen isotopes,and their contact relationship with sparry calcite *** granular calcite veins were likely influenced by the reduction of sulfate *** the other hand,sparry calcite veins with fibrous grains are antitaxial and closely linked to the evolution and maturation of organic *** contain oil and gas inclusions and show a distribution range of homogenization temperature between 90℃ and 120℃ and strong fractionation in oxygen isotopes,indicating formation during the hydrocarbon expulsion *** carbon isotope analysis of the surrounding rocks and veins suggests that the material for vein formation originates from the shale itself,specifically authigenic micritic calcite modified by the action of *** opening of horizontal fractures and vein formation is likely driven by fluid overpressure resulting from undercompaction and hydrocarb

关键词： Calcite veins Shale diagenesis Material source Formation period Formation mechanism