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Particuology 2015年第6期13卷 25-30页

作者： jiecheng yang Chuan-Yu Wu Michael Adams School of Chemical Engineering University of Birmingham Birmingham BI5 2Tr UK Department of Chemical and Process Engineering University ofSu-rrey Guildford GU2 ZXH UK

Particle interactions play a significant role in controlling the performance of dry powder inhalers （DPIs）, which mainly arise through van der Waals potentials, electrostatic interactions, and capillary forces. Our aim is to investigate the influence of electrostatic charge on the performance of DPIs as a basis for improv- ing the formulation of the particle ingredients. The mixing process of carrier and active pharmaceutical ingredient （API） particles in a vibrating container is investigated using a discrete element method （DEM）. The number of APl particles attaching to the carrier particle （i.e., contact number） increases with increas- ing charge and decreases with increasing container size. The contact number decreases with increasing vibrational velocity amplitude and frequency. Moreover, a mechanism governed by the electrostatic force is proposed for the mixing process. This mechanism is different from that previously proposed for the mixing process governed by van der Waals forces, indicating that long-range and short-range adhesive forces can result in different mixing behaviours.

关键词： Electrostatic Particle mixing Dry powder inhaler Discrete element method

Sand storms:CFD analysis of Reynolds stress and collision stress of particles near sand bed

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Particuology 2010年第4期8卷 325-331页

作者： Yu Zhang jiecheng yang Dayou Liu Xiaolin Wei Lixin Yu Institute of Mechanics Chinese Academy of Sdences Beijing 100190 China

Sand storm is a serious environmental threat to humans. Sand particles are transported by saltation and suspension, causing soil erosion in one place and deposition in another. In order to prevent and predict sand storms, the causes and the manners of particle motions must he studied in detail. In this paper a standard k-8 model is used for the gas phase simulation and the discrete element method （DEM） is used to predict the movements of particles using an in-house procedure. The data are summarized in an Eulerian-Eulerian regime after simulation to get the statistical particle Reynolds stress and particle collision stress. The results show that for the current case the Reynolds stress and the air shear stress predominate in the region 20-250 mm above the initial sand bed surface. However, in the region below 3 ram, the collision stress must be taken into account in predicting particle movement.

关键词： Particle Reynolds stress Collision stress Sand bed DEM

CFD-DEM simulation of three-dimensional aeolian sand movement

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Science China(Physics,Mechanics & Astronomy) 2010年第7期53卷 1306-1318页

作者： yang jiecheng ZHANG Yu LIU DaYou WEI XiaoLin Key Laboratory of Environmental Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China

A three-dimensional CFD-DEM model is proposed to investigate the aeolian sand *** results show that the mean particle horizontal velocity can be expressed by a power function of *** probability distribution of the impact and lift-off velocities of particles can be described by a log-normal function,and that of the impact and lift-off angles can be expressed by an exponential *** probability distribution of particle horizontal velocity at different heights can be described as a lognormal function,while the probability distribution of longitudinal and vertical velocity can be described as a normal *** comparison with previous two-dimensional calculations shows that the variations of mean particle horizontal velocity along the heights in two-dimensional and three-dimensional models are ***,the mean particle density of the two-dimensional model is larger than that in reality,which will result in the overestimation of sand transportation rate in the two-dimensional *** study also shows that the predicted probability distributions of particle velocities are in good agreement with the experimental results.

关键词： aeolian sand movement CFD DEM three-dimensional simulation

Mechanistic analysis of solid-liquid flow during injection

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Particuology 2019年第3期17卷 136-145页

作者： Jie Cai Chuan-Yu Wu Yu Guo jiecheng yang Xiaobao Zhao Department of Chemical and Process Engineering University of Surrey Guildford GU2 7XH UK School of Energy and Mechanical Engineering Nanjing Normal University Nanjing 210042 China School of Aeronautics and Astronautics. Zhejiang University Hangzhou 310058 China

Direct injection of retinal cells into patients' eyes is a new and improved therapeutic method to address cataracts, but one challenge is that the survival rate of cells during injection is very low. To solve this problem, in this study, the force distribution on retinal cells in injectors with two needle shapes was analysed by coupling the discrete element method with computational fluid dynamics and implementation of an immersed boundary method. Two injectors were considered: one with a straight needle and the other with a curved needle. The velocities of retinal cells in the injector with a straight needle were slightly higher than those in the injector with a curved needle. In addition, injection speed greatly affected the force distribution on retinal cells, with the retinal cells near the piston subjected to the highest forces during injection. The forces on retinal cells strengthened with increases in both retinal cell concentration and piston displacement.

关键词： Retinal cells Force distribution Injection DEM-CFD Immersed boundary method

Three-dimensional DEM-CFD analysis of air-flow-induced detachment of API particles from carrier particles in dry powder inhalers

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Acta Pharmaceutica Sinica B 2014年第1期4卷 52-59页

作者： jiecheng yang Chuan-Yu Wu Michael Adams School of Chemical Engineering University of BirminghamBirmingham B152TTUK Department of Chemical and Process Engineering University of SurreyGuildford GU27XHUK

Air flow and particle-particle/wall impacts are considered as two primary dispersion mechanisms for dry powder inhalers(DPIs).Hence,an understanding of these mechanisms is critical for the development of *** this study,a coupled DEM-CFD(discrete element method-computational fluid dynamics)is employed to investigate the influence of air flow on the dispersion performance of the carrier-based DPI formulations.A carrier-based agglomerate is initially formed and then dispersed in a uniformed air *** is found that air flow can drag API particles away from the carrier and those in the downstream air flow regions are prone to be ***,the influence of the air velocity and work of adhesion are also *** is shown that the dispersion number(i.e.,the number of API particles detached from the carrier)increases with increasing air velocity,and decreases with increasing the work of adhesion,indicating that the DPI performance is controlled by the balance of the removal and adhesive *** is also shown that the cumulative Weibull distribution function can be used to describe the DPI performance,which is governed by the ratio of the fluid drag force to the pull-off force.

关键词： Dry powder inhaler Dispersion Detachment Air flow DEM-CFD

X-ray phase-sensitive microscope imaging with a grating interferometer:Theory and simulation

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Chinese Physics B 2022年第9期31卷 652-657页

作者： jiecheng yang Peiping Zhu Dong Liang Hairong Zheng Yongshuai Ge Research Center for Medical Artificial Intelligence Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Platform of Advanced Photon Source Technology R&D Laboratory of X-ray Optics and TechnologyBeijing Synchrotron Radiation FacilityInstitute of High Energy PhysicsChinese Academy of SciencesBeijing100049China Beijing Advanced Innovation Center for Imaging Theory and Technology Capital Normal UniversityBeijing 100048China Paul C Lauterbur Research Center for Biomedical Imaging Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China4.Paul C Lauterbur Research Center for Biomedical ImagingShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

A general theoretical framework is presented to explain the formation of the phase signal in an x-ray microscope integrated with a grating interferometer,which simultaneously enables the high spatial resolution imaging and the improved image *** using this theory,several key parameters of phase contrast imaging can be predicted,for instance,the fringe visibility and period,and the conversion condition from the differential phase imaging(DPI)to the phase difference imaging(PDI).Additionally,numerical simulations are performed with certain x-ray optical components and imaging *** with the available experimental measurement[***.113063105(2018)]demonstrates the accuracy of this developed quantitative analysis method of x-ray phase-sensitive microscope imaging.

关键词： x-ray phase contrast imaging x-ray microscope grating interferometer

Model-driven CT reconstruction algorithm for nano-resolution x-ray phase contrast imaging

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Chinese Physics B 2024年第7期33卷 646-650页

作者：谭雨航蔡学宝杨杰成苏婷郑海荣梁栋朱佩平葛永帅 Research Center for Medical Artificial Intelligence Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Institute of Electronic Paper Displays South China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou 510006China Paul C Lauterbur Research Center for Biomedical Imaging Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China

The low-density imaging performance of a zone plate-based nano-resolution hard x-ray computed tomography(CT)system can be significantly improved by incorporating a grating-based Lau interferometer. Due to the diffraction, however,the acquired nano-resolution phase signal may suffer splitting problem, which impedes the direct reconstruction of phase contrast CT(nPCT) images. To overcome, a new model-driven nPCT image reconstruction algorithm is developed in this study. In it, the diffraction procedure is mathematically modeled into a matrix B, from which the projections without signal splitting can be generated invertedly. Furthermore, a penalized weighted least-square model with total variation(PWLSTV) is employed to denoise these projections, from which nPCT images with high accuracy are directly *** experiments demonstrate that this new algorithm is able to work with phase projections having any splitting distances. Moreover, results also reveal that nPCT images of higher signal-to-noise-ratio(SNR) could be reconstructed from projections having larger splitting distances. In summary, a novel model-driven nPCT image reconstruction algorithm with high accuracy and robustness is verified for the Lau interferometer-based hard x-ray nano-resolution phase contrast imaging.

关键词： splitting phase image reconstruction algorithm grating interferometer

CMOS图像传感器质子位移损伤效应实验与分析

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光学学报 2024年第13期44卷 297-305页

作者：杨洁铖殷倩郭刚张艳文李理钟向丽湘潭大学材料科学与工程学院湖南湘潭411105 中国原子能科学研究院国家原子能机构抗辐照应用技术创新中心北京102413

为了分析不同能量质子辐射引发的位移损伤对CMOS图像传感器(CIS)参数影响的差异,以商用CIS为研究对象,在中国原子能科学研究院回旋加速器上开展了50 MeV和90 MeV质子辐照实验,分析了不同能量及注量的质子辐照下器件的暗信号、热像素和... 详细信息

为了分析不同能量质子辐射引发的位移损伤对CMOS图像传感器(CIS)参数影响的差异,以商用CIS为研究对象,在中国原子能科学研究院回旋加速器上开展了50 MeV和90 MeV质子辐照实验,分析了不同能量及注量的质子辐照下器件的暗信号、热像素和随机电码信号(RTS)等参数的退化规律。实验结果表明:平均暗信号的增加可以用位移损伤剂量等效,而相同位移损伤剂量下50 MeV质子辐照后表现出更大的暗信号非均匀性(DSNU)和热像素。像素间RTS现象是质子辐照后不同类型的缺陷所导致的。计算机辅助设计技术(TCAD)模拟结果表明深能级的点缺陷导致载流子浓度更高的热产生率,且团簇缺陷产生率高于简单点缺陷,产生率的不同导致像素间暗信号产生差异,进而产生DSNU和RTS现象。

关键词： CMOS图像传感器质子暗信号随机电码信号缺陷

用于氚产生率在线测量的小型背靠背锂玻璃探测器

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强激光与粒子束 2024年第10期36卷 101-105页

作者：安力杨杰成肖军韩子杰蒋励郭海萍中国工程物理研究院核物理与化学研究所四川绵阳621900

为了实现强伽马场环境下的造氚率在线测量,研制了小型“背靠背”6Li/7Li玻璃探测器。每块锂玻璃闪烁体的尺寸为3.0 mm×3.0 mm×0.4 mm,闪烁体之间及侧面采用0.5 mm二氧化钛作为反射层,整体尺寸为4.0 mm×4.0 mm×1.3 mm。7Li玻璃探测... 详细信息

为了实现强伽马场环境下的造氚率在线测量,研制了小型“背靠背”6Li/7Li玻璃探测器。每块锂玻璃闪烁体的尺寸为3.0 mm×3.0 mm×0.4 mm,闪烁体之间及侧面采用0.5 mm二氧化钛作为反射层,整体尺寸为4.0 mm×4.0 mm×1.3 mm。7Li玻璃探测器测量伽马产生的信号作为6Li玻璃探测器的伽马本底扣除。通过对标准60Co源的伽马射线脉冲幅度谱测量,验证了两个闪烁体对伽马场响应的一致性;在反应堆热中子孔道处和252Cf中子源直照等强伽马环境下测量了脉冲幅度谱,获得的中子伽马信噪比都大于1,表明可以有效扣除伽马本底。验证实验研制的锂玻璃探测器在强伽马场环境下仍能有效甄别伽马,可用于聚变堆和聚变-裂变混合堆实验包层模块内造氚率高精度在线测量。

关键词：强伽马场造氚率在线测量锂玻璃探测器

动物性食品中磺胺类药物残留检测方法研究进展

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畜牧与兽医 2019年第6期51卷 134-139页

作者：杨杰程刘丁溪郭抗抗周宏超西北农林科技大学动物医学院

磺胺类药物是一类人工合成广谱抗菌药物,因为其疗效好且价格相对低廉,在动物养殖和疾病防治中应用较为广泛。但这类药物在使用后易以原型排出,且大剂量、长时间使用时会造成其在动物产品中的残留,对人的健康和环境造成危害。对动物性食... 详细信息

磺胺类药物是一类人工合成广谱抗菌药物,因为其疗效好且价格相对低廉,在动物养殖和疾病防治中应用较为广泛。但这类药物在使用后易以原型排出,且大剂量、长时间使用时会造成其在动物产品中的残留,对人的健康和环境造成危害。对动物性食品中磺胺类药物残留的检测是保证产品食用安全和减少环境污染的重要措施。磺胺类药物由于种类多、使用广泛、在不同动物性产品中的残留情况也不相同,在对其残留进行检测时,应选择合适方法对样品进行处理和检测。本文介绍了样品前处理的常用方法,如液液萃取等传统方法和固相萃取法、固相微萃取法以及基质固相分散法等的原理、优缺点等。对动物性食品中磺胺类药物的检测,应用较多的是高效液相色谱法、毛细管电泳法放射免疫法、免疫传感器发和酶联免疫法等,可使实现对产品中药物残留的定性和定量检测,但是也存在需要专门仪器、检测时间相对较长的问题;快速检测方法最常用的就是胶体金免疫层析方法,可以实现对中多种磺胺类药物的快速和定性的检测,是食品种抗菌药物检测技术研究的一个发展方向。通过对动物性食品中抗微生物残留进行初步筛查,确定为阳性的样品在进行实验室的定量检测,是保证产品安全、可操作的基本程序。研究高通量、敏感、快速、操作简便的动物性食品中磺胺类药物残留检测技术,也是一个重要方面。

关键词：动物性食品磺胺类药物残留样品处理检测