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Modified astrophysical S-factor of 12C+12C fusion reaction at sub-barrier energies

Chinese Physics C 2020年第11期44卷 189-207页

作者： Y.J.li X.Fang B.Bucher K.A.li l.h.ru X.D.Tang China Institute of Atomic Energy Beijing 102413China Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China Idaho National laboratory Idaho FallsID 83415USA Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

The 12C+12C fusion reaction plays a crucial role in stellar evolution and *** main open reaction channels includeα,p,n,and *** more than a half century of efforts,large differences remain among the experimental data of this reaction measured using various *** this work,we analyze the existing data using a statistical *** calculation shows the following:1)the relative systematic uncertainties of the predicted branching ratios decrease as the predicted ratios increase;2)the total modified astrophysical S-factors(S^* factors)of the p andαchannels can be obtained by summing the S^* factors of their corresponding ground-state transitions and the characteristicγrays,while taking into account the contributions of the missing channels to the *** applying corrections based on branching ratios predicted by the statistical model,an agreement is achieved among the different data sets at Ecm>4 MeV,while some discrepancies remain at lower energies,suggesting the need for better measurements in the near *** find that the S^* factor recently obtained from an indirect measurement is inconsistent with the direct measurement value at energies below 2.6 *** recommend upper and lower limits for the 12C+12C S^* factor based on the existing models.A new 12C+12C reaction rate is also recommended.

关键词： carbon burning 12C+12C fusion statistical model quasi-molecular resonance astrophysical S-factor reaction rate stellar evolution

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Studies of the 2α and 3α channels of the ^(12)C+^(12)C reaction in the range of E_(c.m.)=8.9 MeV to 21 MeV using the active target Time Projection Chamber

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Chinese Physics C 2022年第10期46卷 116-125页

作者： X.Y.Wang N.T.Zhang Z.C.Zhang C.G.lu T.l.Pu J.l.Zhang l.M.Duan B.S.Gao K.A.li Y.T.li Y.Qian l.h.ru B.Wang X.D.Xu h.Y.Zhao W.P.lin Z.W.Cai B.F.Ji Q.T.li J.Y.Xu X.D.Tang Joint department for nuclear physics Institute of Modern Physics and Lanzhou UniversityChinese Academy of SciencesLanzhou 730000China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China Key laboratory of Radiation Physics and Technology of the Ministry of Education Institute of Nuclear Science and TechnologySichuan UniversityChengdu 610064China School of Physics and State Key laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China

The ^(12)C+^(12)C fusion reaction was studied in the range of E_(c.m.)=8.9 to 21 MeV using the active-target Time Projection *** full information on all tracks of the reaction products,cross sections of the^(12)C(^(12)C,^(8)Be)^(16)O_(g.s.)channel and the ^(12)C(^(12)C,3a)^(12)C channel could be measured down to the level of a few *** ^(12)C(^(12)C,^(8)Be)^(16)O_(g.s.)reaction channel was determined to be 10_(-8)^(+24) mb at E_(c.m.)=11.1 MeV,supporting the direct a transfer reaction *** ^(12)C(^(12)C,3α)^(12)C reaction channel was studied for the first time using an exclusive *** result does not confirm the anomaly behavior reported in the previous inclusive measurement by Kolata et al.[***.C 21,579(1980)].Our comparisons with statistical model calculations suggest that the 3 a channel is dominated by the fusion evaporation process at E_(c.m.)>19 *** additional contribution of the 3 a channel increases the fusion reaction cross section by 10% at energies above 20 *** also find that an additional reaction mechanism is needed to explain the measured cross section at E_(c.m.)hich point the statistical model prediction vanishes.

关键词： fusion cross section Coulomb barrier Time Projection Chamber active target

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Development of a novel Eu^(3+)-doped tantalate red-emitting phosphor for w-lEDs application

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Journal of Rare Earths 2024年第8期42卷 1479-1488,I0003页

作者： Fan Zeng Jingjing ru Bing Zhao Feiyun Guo Jianzhong Chen College of Chemistry and Materials Fujian Province University Key Laboratory of Green Energy and Environment CatalysisNingde Normal University.Ningde352100China School of Environment and Resources School of Carbon Neutral and Modern IndustryFujian Normal UniversityFuzhou350007China College of Information and Mechanical&Electrical Engineering Ningde Normal UniversityNingde352100China College of Chemistry Fuzhou UniversityFuzhou350108China

Two novel phosphors liBa_(4(1-x))Eu_(4x)Ta_(3)O_(12)(h-lBTO:xEu^(3+)) and li_(0.25)Ba_(1-x)Eu_(x)Ta_(0.75)O_(3)(C-lBTO:xEu^(3+))were prepared successfully by a molten salt *** transformation between these two structures was realized by changing the sintering temperature or changing the Eu^(3+) ions concentration,which was also demonstrated by the X-ray diffraction(XRD),scanning electron microscopy(SEM),diffuse reflectance spectra(DRS),and photoluminescence excitation(PlE) analyses,Both the sintering temperature and the Eu^(3+)ions doping concentration have significant impact on the formation of the crystal *** these phosphors sintered at 1023 K exhibit two major luminescence lines at 594 and 614 nm under nearuV light of 395 nm excitation,corresponding to Eu^(3+)ions typical transitions of ^(5)D_(0)→^(7)F_(1) and ^(5)D_(0)→^(7)F_(2).The optimum concentration of Eu^(3+) ions is 9 mol% for C-lBTO:xEu^(3+) samples and the quenching interaction type is the nearest-neighbor ion *** thermal stability of the C-lBTO:0.09Eu^(3+)sample was investigated in detail and the device application further suggests that C-lBTO:0.09Eu^(3+) can be used as a red phosphor for near-UV excited w-lEDs in lighting.

关键词： Phosphor Tantalate lED device Rare earths

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high-risk factors for delirium in severely ill patients and the application of emotional nursing combined with pain nursing

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World Journal of Psychiatry 2024年第7期14卷 1027-1033页

作者： hong-ru li Yu Guo Emergency Intensive Care Unit The Fourth Affiliated Hospital of Soochow University(Suzhou Dushu Lake Hospital)Suzhou 215000Jiangsu ProvinceChina

BACKGROUND Delirium is a neuropsychiatric syndrome characterized by acute disturbances of consciousness with rapid onset,rapid progression,obvious fluctuations,and preventable,reversible,and other *** with delirium in the intensive care unit(ICU)are often missed or misdiagnosed and do not receive adequate *** To analyze the risk factors for delirium in ICU patients and explore the applica-tion of emotional nursing with pain nursing in the management of *** General data of 301 critically ill patients were retrospectively collected,including histories(cardiovascular and cerebrovascular diseases,hypertension,smoking,alcoholism,and diabetes),age,sex,diagnosis,whether surgery was performed,and patient origin(emergency/clinic).Additionally,the duration of sedation,Richmond Agitation Sedation Scale score,combined emotional and pain care,ven-tilator use duration,vasoactive drug use,drainage tube retention,ICU stay du-ration,C-reactive protein,procalcitonin,white blood cell count,body tempe-rature,Acute Physiology and Chronic health Evaluation II(APAChE II)score,and Sequential Organ Failure Assessment score were recorded within 24 h after ICU *** were assessed for delirium according to confusion assessment method for the ICU,and univariate and multivariate logistic regre-ssion analyses were performed to identify the risk factors for delirium in the *** Univariate logistic regression analysis was performed on the 24 potential risk factors associated with delirium in ICU *** results showed that 16 risk factors were closely related to delirium,including combined emotional and pain care,history of diabetes,and patient *** logistic regression analysis revealed that no combined emotional and pain care,history of diabetes,emergency source,surgery,long stay in the ICU,smoking history,and high APAChE II score were independent risk factors for de-lirium in ICU *** Patients

关键词： Critical illness Delirium Risk factor Intensive care unit Emotional nursing Pain nursing

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Reconstruct recent multi-population migration history by using identical-by-descent sharing

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Journal of Genetics and Genomics 2024年第6期51卷 642-651页

作者： Wenxiao Zhang Kai Yuan ru Wen haifang li Xumin Ni School of Mathematics and Statistics Beijing Jiaotong UniversityBeijing 100044China The Stanley Center for Psychiatric Research Broad Institute of MIT and HarvardCambridgeMA 02142USA Baidu Incorporated Beijing 100085China

Identical-by-descent(IBD)is a fundamental genomic characteristic in population genetics and has been widely used for population history ***,limited by the nature of IBD,which could only capture the relationship between two individuals/haplotypes,existing IBD-based history inference is constrained to two *** this study,we propose a framework by leveraging IBD sharing in multipopulation and develop a method,MatrixiBD,to reconstruct recent multi-population migration ***,we employ the structured coalescent theory to precisely model the genealogical process and then estimate the IBD sharing across multiple *** our model,we establish a theoretical connection between migration history and IBD *** method is rigorously evaluated through simulations,revealing its remarkable accuracy and ***,we apply MatrixiBD to Central and South Asia in the human Genome Diversity Project and successfully reconstruct the recent migration history of three closely related populations in South *** taking into account the IBD sharing across multiple populations simultaneously,MatrixlBD enables us to attain clearer and more comprehensive insights into the history of regions characterized by complex migration dynamics,providing a holistic perspective on intricate patterns embedded within the recent population migration history.

关键词： Population genetics IBD sharing Migration history Structured coalescent theory Gene flow

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Application of surfactant for improving leaching process of weathered crust elution-deposited rare earth ores

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Journal of Rare Earths 2024年第1期42卷 181-190,I0007页

作者： Fang Zhou lisen Zhang Zhiwei Wang Yixin Zhang ru'an Chi Xiaoyan Wu Key laboratory for Green Chemical Process of Ministry of Education Wuhan Institute of TechnologyWuhan430073China

Weathered crust elution-deposited rare earth ores(WREOs)in China are the main source of medium and heavy rare earths in the *** order to improve the seepage and the mass transfer of traditional ammonium salt leaching process of WREOs,surfactants were added in the ammonium sulfate leaching solution and the ammonium chloride leaching *** leaching kinetics,the mass transfer process,and the adhesion work reduction factor calculated from the interfacial properties were studied to reveal the strengthening mechanism of *** the presence of the tested five surfactants,cetyl trimethyl ammonium bromide(CTAB),dodecyl trimethyl ammonium bromide(DTAB),sodium dodecyl sulfate(SDS),sodium oleate and oleic acid,the permeability of WREOs is improved,the rare earth(RE)leaching efficiency increase and the impurity aluminum(Al)leaching efficiency decrease,indicating its promotional effect on the leaching process of ***,CTAB shows a better leaching enhancement,and the optimal addition dosage is 0.4 g/l for the two ammonium salt leaching agent *** kinetics analysis shows the internal diffusion controls model of RE and Al leaching process,and the leaching kinetics equations of RE and Al related to CTAB concentration were obtained for the two ammonium salt leaching *** to the chromatographic plate theory,the mass transfer efficiency of RE increases with the CTAB concentration increasing until 0.4 g/l,which confirms that the optimal CTAB addition is 0.4 g/*** adhesion work and adhesion work reduction factor indicate more favorable permeation as well as the leaching process.

关键词： Weathered crust elution-deposited rare earth ores Surfactant Kinetics Mass transfer

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Effect of cold-working on corrosion induced damage in lug joints

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Defence Technology（防务技术） 2024年第6期36卷 175-182页

作者： Ramanath M.N Chikmath l. Murthy h. Department of Aerospace Engineering Indian Institute of Technology-MadrasChennai 600036India Department of Aeronautical Engineering KLS Gogte Institute of TechnologyBelagavi 590008India

lug joints are preferred joineries for transferring heavy loads to parent components in aerospace *** experience corrosion due to environmental conditions,improper surface finishes and rubbing displacement between the pin and *** causes damage of different sizes and shapes near the *** degradation due to corrosion-induced damage is modelled as a through-pit at one of the identified critical locations through stress *** effect of this pit on fatigue crack initiation life is ***-hole is pre-stressed by cold-working and the benefits of inducing plastic wake on the intended performance of the lug joint during the damages due to corrosion are brought out and compared with non-cold-worked *** analysis is performed on this lug joint with *** results obtained highlight the benefits of cold-working and the methodology can be extended to damage growth and analyse the effect of surface treatments for better structural integrity of components of aerospace vehicles.

关键词： lug joint Corrosion Crack initiation Cold-working Structural integrity

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hydrogen-based mineral phase transformation mechanism investigation of pyrolusite ore

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International Journal of Minerals, Metallurgy and Materials 2024年第11期31卷 2445-2457页

作者： Wang, ruofeng Yuan, Shuai li, Yanjun Gao, Peng li, ru School of Resources and Civil Engineering Northeastern University Shenyang China National-local Joint Engineering Research Center of high-efficient exploitation technology for Refractory Iron Ore Resources Shenyang China

Pyrolusite comprises the foremost manganese oxides and is a major source of manganese production. An innovative hydrogen-based mineral phase transformation technology to pyrolusite was proposed, where a 96.44% distribution rate of divalent manganese (Mn2+) was observed at an optimal roasting temperature of 650°C, a roasting time of 25 min, and an h2 concentration of 20vol%; under these conditions. The manganese predominantly existed in the form of manganosite. This study investigated the generation mechanism of manganosite based on the reduction kinetics, phase transformation, and structural evolution of pyrolusite and revealed that high temperature improved the distribution rate, and the optimal kinetic model for the reaction was the random nucleation and growth model (reaction order, n = 3/2) with an activation energy (Ea) of 24.119 kJ·mol−1. Throughout the mineral phase transformation, manganese oxide from the outer layer of particles moves inward to the core. In addition, pyrolusite follows the reduction sequence of MnO2 → Mn2O3 → Mn3O4 → MnO, and the reduction of manganese oxides in each valence state simultaneously proceeds. These findings provide significant insight into the efficient and clean utilization of pyrolusite.

关键词： reduction pyrolusite phase transformation microstructural evolution

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Spalling characteristics of high-temperature treated granitic rock at different strain rates

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1280-1288页

作者： l.F.Fan Q.h.Yang X.l.Du The Key laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing100124China

The dynamic spalling characteristics of rock are important for stability analysis in rock *** paper presented an experimental investigation on the dynamic spalling characteristics of granite with different temperatures and strain rates.A series of dynamic spalling tests with different impact velocities were conducted on thermally treated granite at different *** dynamic spalling strengths of granite with different temperatures and strain rates were determined.A model was proposed to correlate the dynamic spalling strength of granite,high temperature and strain *** results show that the spalling strength of granite decreases with increasing ***,the spalling strength of granite with a higher strain rate is larger than that with a lower strain *** proposed model can describe the relationship among dynamic spalling strength of granite,high temperature and strain rate.

关键词： Dynamic spalling characteristics high temperature Strain rate Dynamic loading Granite

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hWD-YOlO: A New Vision-Based helmet Wearing Detection Method

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Computers, Materials and Continua 2024年第3期80卷 4543-4560页

作者： Sun l. li h. Wang l. College of Information Science and Technology Beijing University of Technology Beijing 100124 China Chinese Institute of Coal Science Beijing 100013 China State Key laboratory for Intelligent Coal Mining and Strata Control Beijing 100013 China Engineering Research Center of Digital Community of Ministry of Education Beijing 100124 China

It is crucial to ensure workers wear safety helmets when working at a workplace with a high risk of safety accidents, such as construction sites and mine tunnels. Although existing methods can achieve helmet detection in images, their accuracy and speed still need improvements since complex, cluttered, and large-scale scenes of real workplaces cause server occlusion, illumination change, scale variation, and perspective distortion. So, a new safety helmet-wearing detection method based on deep learning is proposed. Firstly, a new multi-scale contextual aggregation module is proposed to aggregate multi-scale feature information globally and highlight the details of concerned objects in the backbone part of the deep neural network. Secondly, a new detection block combining the dilate convolution and attention mechanism is proposed and introduced into the prediction part. This block can effectively extract deep features while retaining information on fine-grained details, such as edges and small objects. Moreover, some newly emerged modules are incorporated into the proposed network to improve safety helmet-wearing detection performance further. Extensive experiments on open dataset validate the proposed method. It reaches better performance on helmet-wearing detection and even outperforms the state-of-the-art method. To be more specific, the mAP increases by 3.4%, and the speed increases from 17 to 33 fps in comparison with the baseline, You Only look Once (YOlO) version 5X, and the mean average precision increases by 1.0% and the speed increases by 7 fps in comparison with the YOlO version 7. The generalization ability and portability experiment results show that the proposed improvements could serve as a springboard for deep neural network design to improve object detection performance in complex scenarios. Copyright © 2024 The Authors. Published by Tech Science Press.

关键词： attention mechanism deep learning feature extraction Object detection safety helmet wearing detection

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