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基于Geant4-CST联合仿真的条纹变像管光电子产生与控制

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光学学报 2024年第3期44卷 300-307页

作者：廖宇翔王子辰唐林冯俞铭赵小艳刘頔威张开春电子科技大学电子科学与工程学院太赫兹中心四川成都611731

碘化铯(CsI)光电阴极广泛应用于超快诊断中,光电子的空间分布、能量分布、时间分布等与条纹变像管的整体性能有着密切的关联。本文联合粒子仿真软件Geant4和三维电磁软件CST实现了对CsI光电阴极的光电子产生与控制过程的全动态模拟。采... 详细信息

碘化铯(CsI)光电阴极广泛应用于超快诊断中,光电子的空间分布、能量分布、时间分布等与条纹变像管的整体性能有着密切的关联。本文联合粒子仿真软件Geant4和三维电磁软件CST实现了对CsI光电阴极的光电子产生与控制过程的全动态模拟。采用Geant4软件对CsI光电阴极的光电转换过程进行建模,分析了二次电子出射能量、时间、位置、角度等发射特性;通过数据交互,统计了出射光电子的分布规律,然后将其应用于CST中建立阴极发射模型,并在CST中设计出一款弧矢、子午方向上放大倍率皆为2的各向异性聚焦条纹变像管。

关键词： X射线光学 Geant4 联合仿真碘化铯光电发射特性各向异性聚焦条纹变像管

Correlation between intrinsic dipole moment and pyroelectric coefficient of Fe-Mg tourmaline

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International Journal of Minerals,Metallurgy and Materials 2014年第2期21卷 105-112页

作者： chang-chun zhao Li-bing Liao Jie Xing School of Science China University of Geosciences School of Materials Science and Technology China University of Geosciences

Single-crystal X-ray diffraction structural data of four Fe-Mg tourmalines with different Fe contents from Xinjiang, Sichuan, and Yunnan Provinces, China, were collected at room temperature and-100oC. The intrinsic dipole moments of polyhedra and the total intrinsic dipole moment of the unit cell were calculated. By comparing the intrinsic electric dipole moments of the X, Y, Z, T, and B site polyhedra, it is found that the T site polyhedron makes the greatest contribution to the total intrinsic dipole moment. The pyroelectric coefficients of four Fe-Mg tourmalines were experimentally determined, and the influence of intrinsic dipole moments on their pyroelectric properties was inves-tigated. The experimental results show that, compared with the case at room temperature, the intrinsic dipole moments change with the total Fe content at-100oC in a completely different way. With the decrease of temperature, the total intrinsic dipole moments of tourmaline de-crease. Over the same temperature interval, the pyroelectric coefficients increase with the increase in intrinsic dipole moment.

关键词： tourmaline pyroelectricity dipole moment polyhedra

Short-term effects of cupping and scraping therapy for chronic nonspecific low-back pain:A prospective,multicenter randomized trial

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Journal of Integrative Medicine 2024年第1期22卷 39-45页

作者： Jun-yan He Xiao-yu Tu Zi-fei Yin Hui Mu Ming-jun Luo Xing-yu Chen Wei-bin Cai Xue zhao Can Peng Fan-fu Fang Can Lü Bai Li School of Traditional Chinese Medicine Naval Medical UniversityShanghai 200433China Department of Rehabilitation Medicine and Physiotherapy the First Affiliated Hospital of Naval Medical UniversityShanghai 200433China Department of Rehabilitation Medicine and Training PLA 458 HospitalGuangzhou 510602Guangdong ProvinceChina No.3 Ward of Acupuncture Rehabilitation Department Guangdong Second Traditional Chinese Medicine HospitalGuangzhou 510095Guangdong ProvinceChina

Background As one of the most common musculoskeletal ailments,chronic nonspecific low-back pain(CNLBP)causes persistent disability and substantial medical *** evidence shows that the incidence rate of CNLBP in young and middle-aged people who are demanded rapidly recovery and social contribution is *** guidelines indicate a reduced role for medicines in the management of *** The present study investigates the short-term effects of cupping and scraping therapy using a medicated balm,compared to nonsteroidal anti-inflammatory drug(NSAID)with a capsaicin plaster,in the treatment of ***,setting,participants and interventions We designed a prospective multicenter randomized clinical trial enrolling patients from January 1,2022 to December 31,2022.A total of 156 patients with CNLBP were randomized into two parallel *** sodium-sustained release tablets were administered orally to participants in the control group for one week while a capsaicin plaster was applied *** in the test group were treated with cupping and scraping using a medical device and medicated *** outcome measures Primary outcome was pain recorded using the visual analogue scale(VAS).Two secondary outcomes were recorded using the Japanese Orthopedic Association low-back pain scale(JOA)and the traditional Chinese medicine(TCM)syndrome integral scale(TCMS)as assessment *** Between baseline and postintervention,all changes in outcome metric scales were statistically significant(Plinear regression analysis,the participants’pain(VAS score)was related to their marital status,age,smoking habits and body mass *** adverse r

关键词： Chronic nonspecific low-back pain Traditional Chinese medicine Cupping and scraping therapy

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护盾式TBM隧道管片壁后豆砾石分布规律

工程科学与技术 2024年第4期56卷 150-160页

作者：吴圣智赵洪海谢宏强董宇苍方霖王明年刘越山东建筑大学土木工程学院山东济南250101 山东建筑大学建筑结构加固改造与地下空间工程教育部重点实验室山东济南250101 河北地质大学城市地质与工程学院河北石家庄050031 四川省交通勘察设计研究院有限公司四川成都610017 西南交通大学土木工程学院四川成都610031

作为管片与围岩间的连接层,TBM隧道中的豆砾石对管片受力具有重要意义。受施工技术、地质条件等影响,豆砾石填充不密实、分布不均匀的现象时常发生,导致管片出现错台、开裂、渗漏水等灾害,故探明豆砾石分布特征是分析管片受力的基础。对... 详细信息

作为管片与围岩间的连接层,TBM隧道中的豆砾石对管片受力具有重要意义。受施工技术、地质条件等影响,豆砾石填充不密实、分布不均匀的现象时常发生,导致管片出现错台、开裂、渗漏水等灾害,故探明豆砾石分布特征是分析管片受力的基础。对此,依托青岛地铁TBM隧道项目,采用地质雷达对管片壁后豆砾石分布特征进行现场测试,并进行单环管片豆砾石吹填数值模拟,分析了隧道直行段、转弯段豆砾石在管片壁后的迁移过程,讨论了地质条件、吹填压力、塌方等因素对吹填质量的影响规律。结果表明:在TBM隧道施工中,拱顶、隧底及转弯段外侧下部为豆砾石空洞多发部位,拱顶与隧底空洞长度大于1m,主要表现为层间脱空,转弯段外侧下部豆砾石空洞规模较小且不密实;地质条件越差,豆砾石出现空洞的概率及规模越大,强风化地层表现最为明显;塌方通过阻碍豆砾石迁移路径、增加碰撞耗能影响豆砾石吹填质量,但影响范围仅在塌方处;提升豆砾石吹填压力可以改善拱顶和隧底豆砾石填充状态,地质条件越好,改善程度越明显,强风化地层豆砾石吹填质量改善不明显;管片壁后豆砾石空洞按照形成原因分为3类:碰撞耗能、塌方掉块和转弯段间隙变小,并给出了3类空洞的多发部位、特征及施工控制建议。

关键词：隧道工程全断面隧道掘进机管片豆砾石分布特征

Fluid Dynamics of Flapping Insect Wing in Ground Effect

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Journal of Bionic Engineering 2014年第1期11卷 52-60页

作者： Jie Wu chang Shu Ning zhao Weiwei Yan Department of Aerodynamics Nanjing University of Aeronautics and Astronautics Nanjing 210016 P. R. China Department of Mechanical Engineering National University of Singapore 10 Kent Ridge Crescent 119260 Singapore College of Metrology and Measurement Engineering China Jiliang University Hangzhou 310018 P. R. China

The fluid dynamics of flapping insect wing in ground effect is investigated numerically in this study. To model the insect wing cross-section in forward-flight mode, the laminar flow over a NACA0012 airfoil animated by a combination of harmonic plunge and pitch rotation is considered. To implement the simulation, the proposed immersed boundary-lattice Boltzmann method is employed. By fixing the Reynolds number and the amplitude of motion, we systematically examine the influences of the distance between the foil and the ground and the flapping frequency on the flow behaviors. As compared to the situation out of ground effect, the forces for foil placed in close proximity to the ground show some differences. The mean drag coefficient is increased at low frequency and decreased at high frequency. Meanwhile, the mean lift coefficient is increased at both low and high frequencies and decreased at middle frequency. Moreover, an interesting phenomenon with oblate vortices due to vortex interaction with the ground is observed.

关键词： flapping insect wing ground effect drag reduction lift enhancement

Clinical features and prognostic analysis of the blastoid variant of mantle cell lymphoma: An analysis of 20 patients from two centers

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Cancer Pathogenesis and Therapy 2024年第1期2卷 62-64页

作者： Sai Huang Shaomei Liu Hongmei Jing Ping Chen Lili Dong Xiaoyu Hao Jian Bo Lu Sun Yu zhao Department of Hematology Senior Department of HematologyThe Fifth Medical Center of PLA General HospitalBeijing 100039China Department of Hematology The First Medical Center of PLA General HospitalBeijing 100853China Medical School of Chinese PLA General Hospital Beijing 100853China Department of Clinical Laboratory The First Medical Center of PLA General HospitalBeijing 100853China Department of Hematology Lymphoma Research CenterPeking University Third HospitalBeijing 100191China Department of Pathology The First Medical Center of PLA General HospitalBeijing 100853China

Managing Editor:Peng Lyu Mantle cell lymphoma(MCL),a relatively uncommon subtype of non-Hodgkin's lymphoma(NHL),constitutes approximately 2%-10%of NHL *** by its inertness,aggressiveness,and incurability,MCL has a med... 详细信息

关键词： lymphoma NHL Clinical

Laser-induced breakdown spectroscopy as a method for millimeter-scale inspection of surface flatness

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Plasma Science and Technology 2024年第9期26卷 148-155页

作者： Jinrui YE Yaju LI zhao ZHANG Xinwei WANG Kewei TAO Qiang ZENG Liangwen CHEN Dongbin QIAN Shaofeng ZHANG Lei YANG Xinwen MA Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000People’s Republic of China Advanced Energy Science and Technology Guangdong LaboratoryHuizhou 516000People’s Republic of China University of the Chinese Academy of Sciences Beijing 100049People’s Republic of China Key Laboratory of Atomic and Molecular Physics&Functional Materials of Gansu Province College of Physics and Electronic EngineeringNorthwest Normal UniversityLanzhou 730070People’s Republic of China Queen Mary University of London Engineering School Northwestern Polytechnical UniversityXi’an 710072People’s Republic of China

A non-contact method for millimeter-scale inspection of material surface flatness via Laser-Induced Breakdown Spectroscopy(LIBS)is investigated *** experiment is performed using a planished surface of an alloy steel sample to simulate its various flatness,ranging from 0 to 4.4 mm,by adjusting the laser focal plane to the surface distance with a step length of 0.2 *** is found that LIBS measurements are successful in inspecting the flatness differences among these simulated cases,implying that the method investigated here is *** is also found that,for achieving the inspection of surface flatness within such a wide range,when univariate analysis is applied,a piecewise calibration model must be *** is due to the complex dependence of plasma formation conditions on the surface flatness,which inevitably complicates the inspection *** solve the problem,a multivariate analysis with the help of Back-Propagation Neural Network(BPNN)algorithms is applied to further construct the calibration *** detailed analysis of the model performance,we demonstrate that a unified calibration model can be well established based on BPNN algorithms for unambiguous millimeter-scale range inspection of surface flatness with a resolution of about 0.2 mm.

关键词： laser-induced breakdown spectroscopy machine learning surface flatness

钙钛矿型CeTaN_(2)O的高压制备及其磁性和电学性质

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物理学报 2024年第8期73卷 83-89页

作者：陈兆亮卢达标叶旭斌赵浩婷张杰潘昭迟振华崔田沈瑶龙有文宁波大学物理科学与技术学院高压物理科学研究院宁波315211 中国科学院物理研究所北京凝聚态物理国家研究中心北京100190 中国科学院大学物理科学学院北京100049 中国科学院合肥物质科学研究院等离子体物理研究所合肥230031 松山湖材料实验室东莞523808

最近研究发现,AB(N,O)_(3)型钙钛矿氧氮化物具有优异的介电、铁电、光催化等性能,在光电子、能源存储和通信等领域展现出广阔的应用前景.但是,目前该类型材料的制备工艺耗时较长且产物纯度较低.本文以氧化物为前驱体、以氨基钠为氮源,... 详细信息

最近研究发现,AB(N,O)_(3)型钙钛矿氧氮化物具有优异的介电、铁电、光催化等性能,在光电子、能源存储和通信等领域展现出广阔的应用前景.但是,目前该类型材料的制备工艺耗时较长且产物纯度较低.本文以氧化物为前驱体、以氨基钠为氮源,利用六面顶压机设备所提供的高温高压环境成功制备了高纯度的钙钛矿型氧氮化物CeTaN_(2)O块体材料,并将制备时间缩短至1 h,实现了快速合成.并对其晶体结构以及物理性质进行了系统的研究.X射线粉末衍射实验和Rietveld精修结果表明,所制备的样品属于正交晶系,空间群为Pnma.X射线吸收谱测试确定了样品的电荷组态以及阴离子组合为Ce^(3+)Ta^(5+)N_(2)O.磁性和比热测试表明,样品属于反铁磁物质,磁相变温度低于2 K.电学输运性能测试表明,样品的电阻率呈现出典型的半导体行为,且符合三维变程跳跃模型.

关键词：高压合成钙钛矿氮化物反铁磁半导体

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A transient model integrating the nanoconfinement effect and pore structure characteristics of oil transport through nanopores

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Petroleum Science 2023年第6期20卷 3461-3477页

作者： Cheng Cao Bin chang zhao Yang Chao Gao School of Mathematics and Computer Science Shaanxi University of TechnologyHanzhong723001ShaanxiChina State Key Laboratory of Continental Dynamics Department of GeologyNorthwest UniversityXi'an710069ShaanxiChina Shaanxi Polytechnic Institute Sch Civil EngnXianyang712000ShaanxiChina Research Institute of Shanxi Yanchang Petroleum(Group)Co.Ltd Xi'an710075ShaanxiChina

Understanding the integrated transport behavior of oil in shale nanopores is critical to efficient shale oil development. In this paper, based on the time-dependent Poiseuille flow momentum equation, we present a novel transient model to describe oil transport in unsteady and steady states. The model incorporates the effect of the critical shift density, apparent viscosity, slip length, and alkane property, as well as pore tortuosity and surface roughness. We evaluated our model through a comparison with other models, experiments, and molecular dynamics simulations. The results show that the development rates of the volume flows of C_(6)–C_(12) alkane confined in inorganic nanopores and C_(12) alkane confined in organic nanopores were faster than that of the corresponding bulk alkane. In addition, the critical drift density positively promoted the volume flow development rate in the unsteady state and negatively inhibited the mass flow rate in the steady state. This effect was clearest in pores with a smaller radius and lower-energy wall and in alkane with shorter chain lengths. Furthermore, both the nanoconfinement effect and pore structure determined whether the volume flow enhancement rate was greater than or less than 1. The rate increased or decreased with time and was controlled mainly by the nanoconfinement effect. Moreover, as the wall energy increased, the flow inhibition effect increased;as the carbon number of alkane increased, the flow promotion effect increased. The results indicate that the proposed model can accurately describe oil transport in shale nanopores.

关键词： Nanopores Transient transport Nanoconfinement effect Tortuosity Roughness Allkane properties