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Model construction and numerical simulation of arterial remodeling after stent implantation with variations of cell concentration

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Medicine in Novel Technology and Devices 2022年第4期16卷 51-59页

作者： Yu Zhang shiliang chen Hanbing Zhang chenyang Ma Tianming Du Aike Qiao Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation Beijing University of TechnologyBeijing100124China

Differences in concentration of molecules can cause different molecular diffusion.This issue has not been well studied in the vascular remodeling process with regards to is-stent restenosis.This study designed and built a model to explore the effect of differences in vascular cell concentration on vascular remodeling.Finite element analysis(FEA)models and the agent-based models(ABMs)were established to simulate the damage and proliferation process of vascular smooth muscle cells(VSMCs)caused by coronary artery stent implantation.The FEA model simulated the expansion of the stent in the coronary artery,the tensile stress was captured and imported into the ABM,and the damaged VSMCs proliferated to reduce their damage level.VSMCs were randomly distributed within a defined domain,and the number of VSMCs in a unit volume(or area)was defined as the concentration of VSMCs.VSMCs with the smallest concentration of VSMCs will preferentially proliferate,which simulates the cell proliferation affected by the concentration of VSMCs.The results showed that after stent implantation,VSMCs proliferated gradually from the severely damaged stent area to the lumen until the artery reached a steady state.By comparison,the loss of arterial lumen and the number of newly grown VSMCs were greater in the presence of the concentration than in its absence.Cells made full use of the lumen space under the influence of concentration differences,so the concentration was of great significance to vascular remodeling.

关键词： Numerical simulation Agent-based model Finite element method Vascular remodeling Cell concentration

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Effects ofiron and temperature on solubility of light rare earth sulfates in multicomponent system of Fe2(SO4)3-H3PO4-H2SO4 synthetic solution

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Journal of Rare Earths 2020年第11期38卷 1243-1250,I0004页

作者： shiliang chen Longsheng Zhao Meng Wang Zongyu Feng Chao Xia Yang Xu Xiaowei Huang National Engineering Research Center for Rare Earth Materials GRINM Group Co.Ltd.Beijing 100088China Grirem Advanced Materials Co. Ltd.Beijing 100088China General Research Institute for Nonferrous Metals Beijing 100088China School of Metallurgy Northeastern UniversityShenyang 110819China

Numerous light rare earth elements(LREE)minerals containing Fe and P were processed by sulfuric acid roasting method,and the leaching solution mainly comprises LREE sulfate,Fe2(SO4)3,H3PO4,and H2SO4,however,the solubility data of LREE sulfates in this system is few.This work studies the solubility of LREE sulfates in independent LREE sulfate system RE2(SO4)3-Fe2(SO4)3-H3 PO4-H2SO4(RE=La,Ce,Pr or Nd)and mixed LREE sulfates system(La,Ce,Pr,Nd)2(SO4)3-Fe2(SO4)3-H3 PO4-H2SO4 at different temperature(25-65℃)and concentrations of Fe2(SO4)3(Fe2 O3,0-50.13 g/L),H2SO4(0.5 mol/L),and H3 PO4(P2 O5,20.34 g/L)based on the industrial operating condition at low liquid and solid ratio 2:1.The solubility of each LREE sulfate in the independent system(La2 O3,12.25-20.88 g/L;CeO2,41.93-62.35 g/L;Pr6 O11,37.34-56.69 g/L;Nd2 O3,26.60-37.63 g/L)is much higher than that of the mixed system(La2 O3,6.95-11.03 g/L;CeO2,10.63-21.51 g/L;Pr6 O11,11.56-20.36 g/L;Nd2 O3,12.36-19.79 g/L)under the same other conditions.The results also indicate that,in the two systems,both Fe and the temperature have negative effects on the solubility of LREE sulfates.That may occur due to the complication reactions between the complexes of RESO4+and Fe(SO4)2-.However,the influence degree of temperature and iron concentration on the LREE sulfates solubility varies in the two systems and among different LREE species.This research is of theoretical significance for optimizing the conditions of the sulfuric acid process for recovering the LREE from the mixed LREE bearing minerals as well as the single LREE containing secondary rare earth scraps.

关键词： Rare earth sulfate Solubility Ferric sulfate Sulfuric acid Phosphoric acid

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Green synthesis of ceria powders with special physical properties by carbon dioxide carbonization

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Journal of Rare Earths 2018年第10期36卷 1084-1089页

作者： Zongyu Feng Xiaowei Huang Meng Wang Xu Sun Yang Xu Qiannan Xue shiliang chen National Engineering Research Center of Rare Earth Materials General Research Institute for Non-ferrous Metals Grirem Advanced Materials Co. Ltd.

In order to improve the application values of Ce element, in this paper, rare earth chloride solution was used as raw material, the pH value was controlled by inorganic alkali, the ceria powders with special physical properties were prepared by carbon dioxide carbonization method. According to characterization of SEM, XRD, and TG-DSC, Ce（OH）3 prepared at pH = 7.5 exhibits smaller particle size than that prepared at other conditions. CeO2 precursor obtained by direct carbonization of Ce（OH）3 shows smaller particle size and narrow size distribution, CeO2 precursor forms at first by carbonization of Ce（OH）3 with the continuous addition of CO2 gas,and the chemical component is indicated to be Ce2 O（CO3）2·6 H2 O.Cubic phase CeO2 powders are obtained by calcined at 750 ℃ for 4 h. The mean particle size D（50） is0.941 μm, and particle size distribution is smaller than 1. The microscopic appearance is homogeneous,with a spherical-like shape and a grain size of 200-500 nm. The light quality characteristics of sedimentation volume and accumulation density are obviously better than those of carbonate precipitation products. The carbonization method can be used not only to obtain ultra-fine rare earth oxides with fine particle size, narrow distribution and high dispersion properties, but also to achieve the reuse of carbon dioxide greenhouse gas.

关键词： Carbon dioxide Carbonization method Ceria Green Special physical properties Rare earths

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杂质锌对顶吹炉铜熔炼系统的影响

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有色金属（冶炼部分） 2024年第3期 19-25页

作者：李林山陈世梁张磊樊友奇铜陵有色金属集团控股有限公司安徽铜陵244100 安徽工业大学冶金工程学院安徽马鞍山243032

鉴于杂质锌对顶吹炉生产中产品质量和生产率的不利影响,系统研究了入炉精矿中锌含量对铜熔炼顶吹炉系统冰铜、炉渣、烟尘的影响。结果表明,随着入炉精矿中锌的平均品位由0.88%上升至3.59%:冰铜中锌含量由0.68%上升至2.16%,不利于后续降... 详细信息

鉴于杂质锌对顶吹炉生产中产品质量和生产率的不利影响,系统研究了入炉精矿中锌含量对铜熔炼顶吹炉系统冰铜、炉渣、烟尘的影响。结果表明,随着入炉精矿中锌的平均品位由0.88%上升至3.59%:冰铜中锌含量由0.68%上升至2.16%,不利于后续降低吹炼渣及精炼渣中铜含量;电炉渣中的锌含量由2.02%上升至5.80%,将导致更多的含锌铁尖晶石固相在高温下析出,使炉渣熔化温度出现升高趋势;上升烟道烟尘中锌含量增至3.34%,含锌物相增加将引入高熔点、高黏度锌铁尖晶石,诱发半熔融状或致密坚硬的结瘤物产生,难以破碎清除;电收尘系统烟尘率由0.96%提升至6.88%,烟尘中锌含量由4.25%增至8.44%,增加电收尘系统负担,降低除尘效率。

关键词：杂质锌烟尘冰铜炉渣上升烟道

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澜沧江——湄公河流域干旱趋势及其对生态系统碳固定的影响

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地理学报 2024年第3期79卷 747-764页

作者：陈世亮李霞钱钊晖王绍强王苗苗刘侦海李卉夏烨赵紫祺李亭谕朱彤彤陈璇蒋赟浩谷鹏中国地质大学(武汉)地理与信息工程学院区域生态过程与环境演变湖北省重点实验室武汉430074 自然资源部国土碳汇智能监测与空间调控工程技术创新中心武汉430074 生态环境部对外合作与交流中心北京100035 中国地质大学(武汉)生物地质与环境地质国家重点实验室武汉430074 中国科学院地理科学与资源研究所中国科学院生态系统网络观测与模拟重点实验室北京100101 福建省农业科学院数字农业研究所福州350000

全球变暖导致干旱事件频发,强度不断增大,对陆地生态系统碳收支产生了重大影响。本文评估了2000—2019年澜沧江—湄公河(澜湄)流域的干旱趋势,并通过标准化异常指数(SAI)、标准化降水蒸散指数(SPEI)、潜在蒸散(PET)、饱和水汽压差(VPD)... 详细信息

全球变暖导致干旱事件频发,强度不断增大,对陆地生态系统碳收支产生了重大影响。本文评估了2000—2019年澜沧江—湄公河(澜湄)流域的干旱趋势,并通过标准化异常指数(SAI)、标准化降水蒸散指数(SPEI)、潜在蒸散(PET)、饱和水汽压差(VPD)和土壤水分(Soil_w)评价了干旱对该流域净生态系统生产力(NEP)的影响。结果表明:①2000—2019年澜湄流域向暖干化发展,主要受降水减少的影响,近1/4的区域遭受了中度以上干旱,其中2009—2016年间干旱事件频发,干旱热点地区位于澜沧江上游和湄公河中下游地区;②尽管澜湄流域碳汇整体上随着气候变暖而增加,但干旱年份植被光合作用降低,生态系统呼吸增加,导致2005年、2010年和2019年湄公河流域生态系统碳源汇发生转变,其中2010年干旱使得GPP减少5.68%,生态系统呼吸增加3.15%,NEP呈现重度异常;③干旱对流域NEP普遍具有滞后效应,整体滞后时间为1~4个月,面积占比为57.82%;④不同水文气候要素对NEP的影响表现出显著的空间差异,其中澜湄流域NEP与VPD整体呈负相关,云南省、缅甸西部、柬埔寨和越南南部的NEP与SPEI呈正相关,而青藏高原NEP主要受到土壤干旱的影响。干旱对澜湄流域生态系统碳固定的影响存在显著的空间异质性,量化干旱对碳固定的影响可以为气候变暖背景下澜湄流域不同地区的生态管理提供参考。

关键词：干旱固碳速率净生态系统生产力澜湄流域标准化降水蒸散指数地理加权回归

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多重力学刺激作用下新内膜重塑模型构建和数值模拟研究

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北京生物医学工程 2024年第2期43卷 118-126页

作者：杨煜佳张晗冰陈诗亮乔爱科北京工业大学环境与生命学部北京100124

目的支架植入造成血管内膜损伤引起新内膜重塑。本文旨在构建支架植入后力学刺激新内膜重塑模型,探讨支架植入后动脉应力和壁面切应力对新内膜重塑的影响及新内膜重塑过程中的血管应力分布。方法建立支架植入模型、支架段血流模型,计算... 详细信息

目的支架植入造成血管内膜损伤引起新内膜重塑。本文旨在构建支架植入后力学刺激新内膜重塑模型,探讨支架植入后动脉应力和壁面切应力对新内膜重塑的影响及新内膜重塑过程中的血管应力分布。方法建立支架植入模型、支架段血流模型,计算支架植入后血管壁力学刺激;通过促生长因子g描述力学刺激与细胞增殖的关系,并构建细胞增殖迁移模型,模拟细胞聚集形成新内膜过程。模拟动脉应力、壁面切应力单独作用下新内膜重塑,以探讨两种力学刺激作用效果的差异;模拟动脉应力和壁面切应力共同作用下新内膜重塑过程,得到重塑过程血管应力分布的变化。结果在动脉应力作用下,新内膜集中在支架段,对支架段管腔影响更大;在壁面切应力作用下新内膜重塑范围更广,除支架段还包括上、下游。新内膜重塑会使血管壁应力峰值和高应力区域减小,重塑后血管壁应力峰值由0.277 MPa下降至0.098 MPa,高应力区域体积减少了64.6%。结论新内膜重塑模型可得到支架植入后血管形貌和应力的动态变化。不同力学刺激作用下,新内膜位置与重塑速度有显著性差异,具有不同特征。新内膜可对血管壁起到一定程度的支撑作用,使血管壁的高应力区域明显减少。

关键词：新内膜重塑支架内再狭窄数值模拟壁面切应力动脉应力生物力学

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AI enhances drug discovery and development

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National Science Review 2024年第3期11卷 52-54页

作者： Fang Bai shiliang Li Honglin Li Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology ShanghaiTech University Lingang Laboratory Innovation Center for AI and Drug Discovery East China Normal University

The advent of the third wave of artificial intelligence(AI) heralds a new era in drug discovery. AI-powered techniques can be characteristic of identifying features that are difficult for humans to interpret from big ...

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不同应力水平对支架降解影响的有限元分析

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北京生物医学工程 2024年第3期43卷 229-235,241页

作者：张晗冰杜田明张艳萍陈诗亮刘圣文乔爱科北京工业大学环境与生命学部北京100124 中国医学科学院阜外医院心内科北京100032

目的建立多种腐蚀因素共同作用的支架降解模型,探究不同应力水平对可降解支架的降解行为及服役性能的影响。方法基于连续损伤力学原理,通过在有限元框架下为独立单元设置腐蚀属性和材料属性,对支架降解过程中的力学强度和几何变化进行模... 详细信息

目的建立多种腐蚀因素共同作用的支架降解模型,探究不同应力水平对可降解支架的降解行为及服役性能的影响。方法基于连续损伤力学原理,通过在有限元框架下为独立单元设置腐蚀属性和材料属性,对支架降解过程中的力学强度和几何变化进行模拟,由此建立均匀腐蚀、应力腐蚀及点腐蚀多种因素共同作用下的支架动态降解模型。分别将支架扩张至血管直径的1.05、1.1、1.2倍为支架提供不同的应力水平,对三种不同工况的降解过程进行数值模拟,分析降解过程中的支架形态、质量损失率及服役时间等。结果支架植入后的应力水平会对其服役性能产生显著影响。随着扩张比的增加,三种应力水平下支架断裂的时间分数分别为0.95、0.82和0.78,断裂时的质量损失率分别为73%、63%和60%。降解过程中由应力腐蚀主导移除的单元数量分别为112、125和139;应力腐蚀作为主导因素的时间分数分别为0.93、0.82和0.78。血管塌陷的时间分数分别为0.83、0.72和0.68,并且血管塌陷发生在支架失去其几何完整性之前。结论对于可降解支架,选择恰当的扩张比对获得良好的支架治疗效果有重要影响。高扩张比在更好维持管腔通畅性的同时也通过提高花冠处的应力水平使局部应力腐蚀作用增加,从而缩短了支架的服役时间,导致其更容易发生不均匀降解。

关键词：可降解支架植入扩张比应力腐蚀支撑性有限元分析

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Numerical investigation of sinusoidal pulsating gas intake to intensify the gas-slag momentum transfer in the top-blown smelting furnace

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International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 301-314页

作者： Zhanghao Wan shiliang Yang Desong Kong Dongbo Li Jianhang Hu Hua Wang State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming University of Science and TechnologyKunming 650093China Southwest Copper Branch Yunnan Copper Co.Ltd.Kunming 650102China

The variation characteristics of bubble morphology and the thermal-physical properties of bubble boundary in the top-blown smelting furnace were explored by means of the computational fluid dynamics method.The essential aspects of the fluid phase(e.g.,splashing volume,dead zone of copper slag,and gas penetration depth)were explored together with the effect of sinusoidal pulsating gas intake on the momentum-transfer performance between phases.The results illustrated that two relatively larger vortices and two smaller vortices appear in the bubble waist and below the lance,respectively.The expansion of larger ones as well as the shrinking of smaller ones combine to cause the contraction of the bubble waist.Compared to the results of the case with a fixed gas injection velocity(V_(g)=58 m/s),the splashing volume and dead zone volume of the slag under the V_(g)=58+10sin(2πt)condition are reduced by 24.9%and 23.5%,respectively,where t represents the instant time.Gas penetration depth and slag motion velocity of the latter are 1.03 and 1.31 times high-er than those of the former,respectively.

关键词： top-blown smelting furnace pulsed flow volume of fluid penetration depth splashing volume

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Utilization of recycled solid waste as ecological reclamation materials based on plant growth experiments and soil quality analysis

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Journal of Mountain Science 2024年第3期21卷 820-834页

作者： QIN Xiaochun NI Anchen YANG Dongxiao XING Wenhu LIU shiliang College of Civil Engineering Beijing Jiaotong UniversityBeijing 100044China Shanxi Road&Bridge Construction Group Co. LtdShanxi 030006China School of Environment Beijing Normal UniversityBeijing 111875China

During the highway construction,a large number of spoil areas will be generated while a large amount of waste slag and soil could not be rationally utilized.Besides,the vegetation recovery is slow in the spoil areas due to the soil depletion.Aiming at recycling the solid waste,the sieved engineering waste slag with local red clay and corn straw biochar was supplied to solve the problem of insufficient nutrients in engineering waste slag and soil.In addition,planting experiments of alfalfa(Medicago sativa L.)and Amorpha fruticosa L.combined with physical and chemical experiments were carried out to prove the feasibility of the novel improved substrate for the reclamation of spoil areas.The results show that the substrate's improvement effect is mainly affected by the soil to slag ratio and the biochar content.The improvement effect of soil matrix in highway spoil area decreases with the increase of the waste slag content,especially when the soil-slag ratio is less than 3,and the promotion of plants is limited.On the contrary,the improvement effect is proportional to the biochar content(3%-8%).But it is noted that the Cu and Pb in the soil will exceed the clean limit corresponding to the Nemero soil pollution index level when the biochar content is 8%.Therefore,it is recommended that the soil-slag ratio should be≥3,and the biochar content should reach 3%-5%.This research provides experimental basis and technical support for utilizing solid waste resources in the reclamation of highway spoil areas.

关键词： Highway Spoil area Waste slag Modified soil Ecological reclamation

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