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Nuclear clustering in light neutron-rich nuclei

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Nuclear Science and Techniques 2018年第12期29卷 112-127页

作者： yang Liu yan-lin ye School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking University

Clustering is a general phenomenon observed in light nuclei, especially in neutron-rich nuclei in which molecular configurations can be formed with various combinations of valence neutrons. Thus far, many theoretical models have been developed to describe nuclear clustering phenomena. These models are outlined in this review article, with an emphasis on their basic formulations and physical ingredients. In addition, various experimental tools, such as inelastic excitation and decay, transfer reactions, and resonant scattering reactions, have been applied to investigate the cluster structures inside the nucleus. Each tool possesses certain advantages and favorable applications, which are also described. In the case of neutron-rich nuclei, cluster structures may be configured as molecular states that form rotational bands with an extremely large moment of inertia and generate relatively large cluster decay width. The major experimental criteria for the identification of cluster formation are discussed herein.

关键词：轻原子核中子聚类转移反应簇结构物理成分应用程序试验性

Systematic CDCC calculations for ~11Be+p elastic scattering

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Science China(Physics,Mechanics & Astronomy) 2016年第3期59卷 70-74页

作者： Jie Chen Jian ling Lou Dan yang Pang yan lin ye School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking University School of Physics and Nuclear Energy Engineering Beihang University

Continuum discretised coupled-channels （CDCC） method with a 10Be（0＋）＋ n two-body cluster model is applied to systematically analyze the elastic scattering of the halo nucleus alBe from the proton target at various incident energies below 100 MeV/nucleon. Using the renormalized 10Be-p potential deduced from the 10Be ＋ p elastic scattering data, the differential cross sections of 11 Be ＋ p scattering are well reproduced by the CDCC calculations without any further adjustment parameters, demonstrating the applicability of this approach for describing the scattering of exotic nuclei based on the scattering of the less exotic core nuclei.

关键词： elastic scattering CDCC 11Be

Performance of a small AT-TPC prototype

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Nuclear Science and Techniques 2018年第7期29卷 138-144页

作者： Jin-yan Xu Qi-Te Li yan-lin ye Jian Gao Jia-Xing Han Shi-Wei Bai Ka-Hou Ng School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking University

A small prototype of an active-target time projection chamber detector based on the gas electron multiplier(GEM) readout technique was designed and *** calculations were performed to analyze the electric field distribution and optimize the *** particular,a guard ring installed above the GEM foil may play an important role in shaping the electric field in the gas vessel and improving the overall performance of the *** best results were obtained at a guard-ring voltage of-950 *** using a collimated a-particle source,an energy resolution of 3.6–4.0 ke V can be achieved for deposited energies of 18–21 keV,respectively.A position resolution of less 0.2 mm was observed along the electron drift direction,whereas the resolution in the readout plane was approximately 0.45 mm.A time resolution of less than 20 ns was *** using helium as the primary working gas as well as the target material,a t a elastic scattering events can be clearly imaged.

关键词：原型性能优化设计模拟计算工作气体宝石时间电子

Recent progress in subatomic particle detection technology

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Frontiers of physics 2013年第5期8卷 548-554页

作者： Zhi-Huan Li Jian-ling Lou Qi-Te Li Yu-Cheng Ge Zhe-Wei Yin yan-lin ye School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking University Beijing 100871 China

Particle detection technologies have been largely advanced in ,boratory over the past decade. A neutron sphere was built to detect the decay neutron emitted from the implanted unstable nu eleus, whereas a multi-neutron correlation spectrometer was implemented to detect the forward moving neutrons resulting from breakup reactions. Charged particle telescopes are now equipped with double sided Silicon strip detectors which have excellent energy and position resolutions. Large size gas chambers, such as resistive plate chambers, have been developed in order to achieve high Derformances related to timing or position measurements. The advances of these technologies con tribute substantially to such large science project, as LHC-CMS, and to the experiments with the radioactive nucleus beams.

关键词： subatomic particles detection nuclear physics

Control and data acquisition system for collinear laser spectroscopy experiments

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Nuclear Science and Techniques 2023年第3期34卷 64-72页

作者： Yong-Chao Liu Xiao-Fei yang Shi-Wei Bai Shu-Jing Wang Peng Zhang Yin-Shen Liu Han-Rui Hu yang-Fan Guo Zhou yan Ze-Yu Du Wen-Cong Mei Zhe-yang lin Hong-Wei Li yan-lin ye Qi-Te Li Chuang-ye He School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China China Institute of Atomic Energy(CIAE) P.O.Box 275(10)Beijing 102413China

A control and data acquisition system was implemented for the recently developed collinear laser spectroscopy *** system is dedicated to data recording,storage,processing,monitoring of the beam intensity and energy,and visualization of various *** comparison to the conventional resonance nuclear reaction system,the key technique is the precise synchronization of the detected counts with the actual scanning voltage(or probing laser frequency).The functions of the system were tested by measuring the hyperfine structure spectra of stable calcium(e.g.,^(40)Ca^(+))and radioactive potassium(e.g.,^(38)K)in the bunched and continuous modes,*** system will be routinely applied and further improved in subsequent laser spectroscopy experiments on unstable isotopes at the Beijing Radioactive Ion-beam Facility(BRIF).

关键词： Collinear laser spectroscopy Hyperfine structure Data acquisition system Voltage scanning

Investigations of Water Flow Behaviors Induced by Local Temperature Variations through a Single Rough Fracture for the Enhanced Geothermal Systems

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Journal of Thermal Science 2024年第3期33卷 1055-1064页

作者： LI Jiawei ye lin Department of Energy and Power Engineering Tsinghua UniversityBeijing100084China School of Power and Energy Northwestern Polytechnical UniversityXi’an710072China

In recent years,Enhanced Geothermal System(EGS)technologies have been applied to the geothermal resources production in the Hot Dry Rock(HDR).The core of EGS technologies is to adopt hydraulic fracturing in the reservoir to create a connected network of discrete fractures with the consideration of water as a working fluid for hydraulic fracturing and heat *** paper investigates the characteristics of water flow behaviors through a single rough fracture under different temperature and pressure conditions.A single fracture model with rough fracture surfaces is constructed and then characterized,and influences of the anisotropic factor on the average tortuosity and frictional resistance coefficient of water flow through a single fracture with rough surfaces have been compared and *** consideration of other impacting factors(temperature,pressure,fracture roughness),the impact of mass flow rate has also been *** simulation results present that changes of average tortuosity for water flow through a single rough facture are mainly affected by *** can be observed that higher temperature leads to larger average tortuosity but the frictional resistance coefficient shows an opposite *** for pressure conditions,it is found that effects of pressure on average tortuosity and frictional resistance coefficient is very small,which can be neglected under high pressure ***,the average tortuosity shows a progressively linear relationship with the mass flow *** the contrary,the frictional resistance coefficient has a negative relationship with the mass flow *** is revealed that when the mass flow rate reaches a critical point,the influences of temperature on the frictional resistance coefficient will be *** of single rough fractures with different anisotropic factors show that values of average tortuosity and frictional resistance coefficient have positive relationships with the increase

关键词： single rough fracture tortuosity frictional resistance enhanced geothermal system

Normal sperm head morphometric reference values in fertile Asian males

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Asian Journal of Andrology 2024年第3期26卷 315-320页

作者： ye-lin Jia Ying-Bi Wu lin Yu yan Zheng Ting-Ting yang yan-Yun Wang Bin Zhou lin Zhang Fu-Ping Li Laboratory of Andrology West China Second University Hospital Human Sperm BankChengdu 610000China Laboratory of Molecular Translational Medicine Center for Translational MedicineChengdu 610061China Key Laboratory of Birth Defects and Related Diseases of Women and Children(Sichuan University) Ministry of EducationChengdu 610061China NHC Key Laboratory of Chronobiology West China Second University HospitalSichuan UniversityChengdu 610000China

Sperm head morphology is crucial for male factor infertility diagnosis and assessment of male reproductive *** are available to analyze sperm head morphology,but they are limited by poor methodology comparability and *** study aimed to explore comprehensive and new normal morphometric reference values for spermatozoa heads infertile Asian *** automated sperm morphology analysis system captured 23152 stained spermatozoa from confirmed *** these samples,1856 sperm head images were annotated by three experienced laboratory technicians as“normal”.Weemployed 14 novel morphometric features to describe sperm head size(head length,head width,length/width ratio,and girth),shape(ellipse intersection over union,girth intersection over union,short-axis symmetry,and long-axis symmetry),area(head,acrosome,postacrosomal areas,and acrosome area ratio),and degrees of acrosome and nuclear *** straight-forwardmethod for the morphometric analysis of sperm by accurate visual measurements is clinically *** measured parameterspresent valuable information to establish morphometric reference intervals for normal sperm heads in fertile Asian *** detailed measurement data will be valuable for interlaboratory comparisons and technician *** vitro fertilizationand andrology laboratory technicians can use these parameters to perform objective morphology evaluation when assessing malefertilization potential.

关键词： fertile Asian males head morphometric reference value normal spermatozoa

Path-Dependent Progressive Failure Analysis for 3D-Printed Continuous Carbon Fibre Reinforced Composites

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Chinese Journal of Mechanical Engineering 2024年第4期37卷 84-93页

作者： Yuan Chen lin ye School of System Design and Intelligent Manufacturing(SDIM) Southern University of Science and TechnologyShenzhen 518055China Shenzhen Key Laboratory of Intelligent Manufacturing for Continuous Carbon Fibre Reinforced Composites Southern University of Science and TechnologyShenzhen 518055China

In order to predict the damage behaviours of 3D-printed continuous carbon fibre(CCF)reinforced composites,when additional short carbon fibre(SCF)composite components are employed for continuous printing or special functionality,a novel path-dependent progressive failure(PDPF)numerical approach is ***,a progressive failure model using Hashin failure criteria with continuum damage mechanics to account for the damage initiation and evaluation of 3D-printed CCF reinforced polyamide(PA)composites is developed,based on actual fibre placement trajectories with physical measurements of 3D-printed CCF/PA ***,an elastic-plastic model is employed to predict the plastic damage behaviours of SCF/PA ***,the accuracy of the PDPF model was validated so as to study 3D-printed CCF/PA composites with either negative Poisson's ratio or high *** results demonstrate that the proposed PDPF model can achieve higher prediction accuracies in mechanical properties of these 3D-printed CCF/PA *** analyses show that the stress distribution is generally aggregated in the CCF areas along the fibre placement paths,and the shear damage and matrix tensile/compressive damage are the key damage *** study provides a new approach with valuable information for characterising complex 3D-printed continuous fibre-matrix composites with variable mechanical properties and multiple constituents.

关键词： 3D printing Continuous carbon fibre Modelling Energy absorption Negative Poisson's ratio

Commissioning of a high-resolution collinear laser spectroscopy apparatus with a laser ablation ion source

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Nuclear Science and Techniques 2022年第1期33卷 98-106页

作者： Shi-Wei Bai Xiao-Fei yang Shu-Jing Wang Yong-Chao Liu Peng Zhang Yin-Shen Liu Han-Rui Hu yang-Fan Guo Jin Wang Ze-Yu Du Zhou yan Yun-Kai Zhang yan-lin ye Qi-Te Li Yu-Cheng Ge Chuang-ye He School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China China Institute of Atomic Energy(CIAE) P.O.Box 275(10)Beijing 102413China

Collinear laser spectroscopy is a powerful tool for studying the nuclear spins,electromagnetic moments,and charge radii of exotic *** study the nuclear properties of unstable nuclei at the Beijing Radioactive Ion-beam Facility(BRIF)and the future High Intensity Heavy-ion Accelerator Facility(HIAF),we developed a collinear laser spectroscopy apparatus integrated with an offline laser ablation ion source and a laser *** overall performance of this state-of-the-art technique was evaluated,and the system was commissioned using a bunched stable ion *** high-resolution optical spectra for the 4s ^(2)S_(1/2)→4p^(2)P_(3/2)(D2)ionic transition of ^(40;42;44;48)Ca isotopes were successfully *** extracted isotope shifts relative to ^(40)Ca showed excellent agreement with the literature *** system is now ready for use at radioactive ion beam facilities such as the BRIF and paves the way for the further development of higher-sensitivity collinear resonance ionization spectroscopy techniques.

关键词： Nuclear properties Collinear laser spectroscopy Laser-ablation ion source Photon detection Isotope shift