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A preliminary study on numerical simulation of microwave heating process for chemical reaction and discussion of hotspot and thermal runaway phenomenon

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Science China(Physics,Mechanics & Astronomy) 2009年第4期52卷 551-562页

作者： ZHAO Xiang HUANG KaMa YAN LiPing yao yuan College of Electronics and Information Engineering Sichuan UniversityChengdu 610064China Chengdu University of Information Technology Chengdu 610041China

The nonlinear process of microwave heating chemical reaction is studied by means of numerical simulation. Especially,the variation of temperature in terms of space and time,as well as the hotspot and thermal runaway phenomena are discussed. Suppose the heated object is a cylinder and the incident electromagnetic(EM) wave is plane wave,the problem turns out to be a coupling calculation of 2D multi-physical fields. The integral equation of EM field is solved using the method of moment(MoM) and the thermal conduction equation is solved using a semi-analysis method. Moreover,a method to determine the equivalent complex permittivity of reactant under the heating is presented in order to perform the calculation. The numerical results for water and a dummy chemical reaction(A) show that the hotspot is a ubiquitous phenomenon in microwave heating process. When the radius of the heated object is small,the highest temperature occurs somewhere inside the object due to the concentration of the EM wave. While the radius increases to a certain degree,the highest temperature occurs somewhere close to the surface due to the skin effect,and the whole high temperature area shows crescent-shaped. That is in accordance with basic physical principles. If the radius is kept the same in the heating process,the hotspot position of water does not change,while that of reaction A with several radius values varies. For either water or A,the thermal runaway phenomenon in which small difference of radius results in large difference of highest temperature,occurs easily when the radius is small. On the contrary,it is not evident when the radius is large. Moreover,it is notable that the highest temperature in water shows oscillating decreasing trend with the increase of radius,but in reaction A almost decreases monotonously. Further study should be performed to determine if this difference is only an occasional occurrence.

关键词： numerical simulation microwave heating chemical reaction hotspot phenomenon thermal runaway

Optimization of CHARMM force field parameters for the chalcone fragment

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Science China Chemistry 2012年第12期55卷 2580-2586页

作者： ZHANG Hui yao yuan QI XiaoLi LI ZeSheng College of Chemical and Environmental Engineering Harbin University of Science and TechnologyHarbin 150080China Academy of Fundamental and Interdisciplinary Sciences Department of Chemistry Harbin Institute of Technology Harbin 150080 China Key Laboratory of Cluster Science of Ministry of Education School of Chemistly Beijing Institute of Technology Beijing 100081China

In this work,we developed the CHARMM all-atom force field parameters for the nonstandard biological residue chalcone,followed by the standard protocol for the CHARMM27 force field *** data were generated via ab initio calculations at the MP2/6-31G* and HF/6-31G* *** reference data included interaction energies between water and the model compound F(a fragment of chalcone).Bond,angle,and torsion parameters were derived from the ab initio calculations and renormalized to maintain compatibility with the existing CHARMM27 parameters of standard *** optimized CHARMM parameters perform well in reproducing the target *** expect that the extension of the CHARMM27 force field parameters for chalcone will facilitate the molecular simulation studies of the reaction mechanism of intramolecular cyclization of chalcone catalyzed by chalcone isomerase.

关键词： CHARMM force field parameters chalcone

Helical supramolecular nanorods via sequential meticulous tailoring of noncovalent interaction and light irradiation

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Science China Chemistry 2022年第9期65卷 1749-1757页

作者： Zhenghui Liu yuan yao Xinfeng Tao Jie Wei Shaoliang Lin Shanghai Key Laboratory of Advanced Polymeric Materials Key Laboratory for Ultrafine Materials of Ministry of EducationSchool of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China

Polymers are widely recognized to entail random conformations in good solvent governed by the need for achieving the highest entropy to reach thermodynamic *** this context,it remains grand challenging to directly arrange them into ordered conformation as building blocks for further self-assembling into hierarchal ***,we report a simple yet viable strategy to progressively assemble rationally designed azobenzene-containing alternating copolymer(i.e.,poly(binaphthylspacer-azobenzene-alt-hexaethylene glycol),denoting P(BNPSAzo-alt-EG_(6))_(24))into helical supramolecular ***,P(BNPSAzo-alt-EG_(6))_(24) chains in good solvent are firstly self-assembled into helical single molecular micelles in good solvent via intramolecular π-π interaction between binaphthyl groups as well as between azobenzene ***,by simply introducing water into the solution that is allowed to dwell for a certain period of time,single molecular micelles are selfassembled into well-defined ***,these isotropic vesicles could be further transformed into anisotropic helical supramolecular nanorods with enhanced aggregate-induced emission(AIE)capability driven by repeated,light-triggered cistrans isomerization of azobenzene moieties with the retention of π-π interacted binaphthyl *** study highlights a facile route to yielding morphology-rich,functional assemblies from a single polymer via judiciously exploiting non-covalent interaction and light of different wavelength as highly effective trigger in a non-invasive manner for potential applications in controlled release and fluorescent labelling.

关键词： alternating polymer conformational organization assembly chirality transmission light response azobenzene

Increasing stiffness promotes pulmonary retention of ligand-directed dexamethasone-loaded nanoparticle for enhanced acute lung inflammation therapy

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Bioactive Materials 2023年第2期20卷 539-547页

作者： Yinglan Yu Shujie Li yuan yao Xinran Shen Lian Li yuan Huang Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial TechnologyWest China School of PharmacySichuan UniversityChengdu610041China

Inhaled nanoparticles(NPs)need to penetrate the bronchial mucosa to deliver drug payloads deeply in the lung for amplified local ***,the bronchial mucociliary barrier eliminates NPs rapidly,which considerably limits their mucosal *** this study,we find that surface ligand modification and stiffness adjustment of NPs contribute to the significantly enhanced bronchial mucosal absorption and pulmonary retention of inhaled *** utilize neonatal Fc receptor ligand(FcBP)to modify the rationally designed low stiffness NPs(Soft-NP)and high stiffness NPs(Stiff-NP)to target bronchial *** an acute lung inflammation rat model,after intranasal administration with dexamethasone-loaded NPs,Stiff-NP endowed with FcBP displays superior therapeutic *** in vitro data demonstrate that the promotion effect of FcBP to bronchial mucosal absorption of Stiff-NP dominates over *** could be attributed to the higher affinity between ligand-receptor when incorporating FcBP on the Stiff-NP ***,high stiffness modulates more actin filaments aggregation to mediate endocytosis,along with strengthened Ca2+signal to enhance ***,we highlight that FcBP-modified NPs with higher stiffness would be a potential pulmonary drug delivery system.

关键词： Pulmonary drug delivery Mucus barrier Epithelial barrier Stiffness Ligand modification Acute lung inflammation

Constrained maximum weighted bipartite matching:a novel approach to radio broadcast scheduling

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Science China(Information Sciences) 2019年第7期62卷 156-169页

作者： Shaojiang WANG Tianyong WU yuan yao Dongbo BU Shaowei CAI State Key Laboratory of Computer Science Institute of SoftwareChinese Academy of Sciences School of Computer Science and Technology University of Chinese Academy of Sciences Beijing Key Lab of Human-Computer Interaction Institute of SoftwareChinese Academy of Sciences Institute of Computing Technology Chinese Academy of Sciences

Given a set of radio broadcast programs, the radio broadcast scheduling problem is to allocate a set of devices to transmit the programs to achieve the optimal sound quality. In this article, we propose a complete algorithm to solve the problem, which is based on a branch-and-bound(BnB) algorithm. We formulate the problem with a new model, called constrained maximum weighted bipartite matching(CMBM),i.e., the maximum matching problem on a weighted bipartite graph with constraints. For the reduced matching problem, we propose a novel BnB algorithm by introducing three new strategies, including the highest quality first, the least conflict first and the more edge first. We also establish an upper bound estimating function for pruning the search space of the algorithm. The experimental results show that our new algorithm can quickly find the optimal solution for the radio broadcast scheduling problem at small scales, and has higher scalability for the problems at large scales than the existing complete algorithm.

关键词： radio broadcast scheduling branch-and-bound algorithm constrained maximum weighted bipartite matching Kuhn-Munkres algorithm strategy combinations

Investigations on lubrication characteristics of high-speed electric multiple unit gearbox by oil volume adjusting device

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2022年第12期23卷 1013-1026页

作者： Shuai SHAO Kai-lin ZHANG yuan yao Yi LIU Jun GU State Key Laboratory of Traction Power Southwest Jiaotong UniversityChengdu 610031China Suzhou shonCloud Engineering Sofiware Co.Ltd. Suzhou 215100China

In this paper,a numerical simulation model of the flow field in a gearbox with an oil volume adjusting device is established for the first time to study its influence on the lubrication characteristics of a high-speed electric multiple unit(EMU)*** moving particle semi-implicit(MPS)method is used to numerically simulate the internal flow field of the gearbox of the high-speed EMU under working *** effects of the velocity of the high-speed EMU,the immersion depth,and the oil sump temperature on the power loss of the gears and the lubricant quantity of each bearing are studied and provide an effective tool for the quantitative evaluation of the lubrication characteristics of the *** lubrication characteristics of the gearbox under different working conditions are studied when the oil volume adjusting device is closed and *** results show that the oil volume adjusting device mainly changes the amount of lubricant stirred by the output gear by changing the flow rate of lubricant from the cavity pinion(Cavity P)to the cavity gear(Cavity G),and thus affects the power loss of gears and the lubricant quantity of each bearing.

关键词： High-speed electric multiple unit(EMU) Splash lubrication Mesh-free moving particle semi-implicit(MPS)method Bearing lubrication Churning power loss Oil volume adjusting device

面向TDI技术地面验证的激光干涉仪本底噪声分析

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量子电子学报 2024年第4期41卷 649-658页

作者：左凌云师浩森姚远蒋燕义马龙生华东师范大学精密光谱科学与技术国家重点实验室上海200241

在空间引力波探测中,由于星间激光干涉臂不等,导致激光频率噪声不能共模消除,从而使微弱的引力波信号被激光频率噪声淹没。时间延迟干涉(TDI)技术通过将激光相位数据在时间上延迟,构成虚拟等臂干涉,从而能减小激光频率噪声对引力波信号... 详细信息

在空间引力波探测中,由于星间激光干涉臂不等,导致激光频率噪声不能共模消除,从而使微弱的引力波信号被激光频率噪声淹没。时间延迟干涉(TDI)技术通过将激光相位数据在时间上延迟,构成虚拟等臂干涉,从而能减小激光频率噪声对引力波信号探测的影响。为了在地面验证TDI技术能够将激光频率噪声对引力波探测的影响降低至3×10^(-7) Hz/√Hz(傅里叶频率1 mHz处),需要分析TDI地面验证系统本底噪声的主要来源。通过实验测量和计算分析,提出了面向TDI技术地面验证的激光干涉仪的重要参数设计要求,包括激光干涉臂的臂长差、激光频率稳定度、气压稳定度、激光功率稳定度以及各部件温度稳定度等。

关键词：激光技术空间引力波探测激光干涉仪噪声分析时间延迟干涉激光频率噪声

空间大数据支持的鞍山市历史文化资源交通适宜性评价

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辽宁科技大学学报 2024年第2期47卷 154-160页

作者：张何欣韩颖王松妍姚远大连市自然资源事务服务中心辽宁大连116000 辽宁科技大学土木工程学院辽宁鞍山114051 大连理工大学城市学院辽宁大连116600 易智瑞信息技术有限公司沈阳分公司辽宁沈阳110003

针对鞍山市历史文化资源开发利用以及保护管理工作中未引入地理空间信息导致绝大部分历史文化资源的地理位置不明确、社会公众极难实地探访等问题,提出一种历史文化资源交通适宜性综合评价方案。建立鞍山市历史文化资源专题地理空间数据... 详细信息

针对鞍山市历史文化资源开发利用以及保护管理工作中未引入地理空间信息导致绝大部分历史文化资源的地理位置不明确、社会公众极难实地探访等问题,提出一种历史文化资源交通适宜性综合评价方案。建立鞍山市历史文化资源专题地理空间数据库,以参观者的出行方式为出发点对传统交通通达度模型进行改进,构建参观者视角下的交通适宜性模型。在完成路网密度、站场距离2项指数计算的基础上,采用层次分析法科学确定数据合成权重,实现模型的量化计算,以模型计算结果评价鞍山市历史文化资源的交通适宜性。结果表明,参观者视角下的交通适宜性模型能够准确反映参观者多种出行方式的便捷程度;鞍山市历史文化资源的总体交通适宜性良好,有利于历史文化资源的开发利用与保护管理。

关键词：地理信息系统层次分析法历史文化资源交通适宜性

青年男性军人精神障碍者自杀未遂的危险因素分析

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职业与健康 2024年第2期40卷 205-209页

作者：徐玉林张渊阎同军徐超姚远许涛空军杭州特勤疗养中心疗养二区心理科浙江杭州310012 空军杭州特勤疗养中心疗养二区检验科浙江杭州310012 空军杭州特勤疗养中心疗养五区航空心理训练科江苏无锡214000 解放军联勤保障部队第九〇四医院精神科江苏常州213000 解放军联勤保障部队第九〇三医院急诊科浙江杭州310012

目的分析青年男性军人精神障碍者自杀未遂的危险因素,为军人自杀早期防控提供参考。方法 2021年6月—2022年3月,连续入组60例确诊精神障碍的青年男性军人,分为自杀未遂组(33例)和非自杀未遂组(27例),收集两组人员社会人口学、临床特征... 详细信息

目的分析青年男性军人精神障碍者自杀未遂的危险因素,为军人自杀早期防控提供参考。方法 2021年6月—2022年3月,连续入组60例确诊精神障碍的青年男性军人,分为自杀未遂组(33例)和非自杀未遂组(27例),收集两组人员社会人口学、临床特征资料,采用贝克抑郁自评问卷(Beck depression inventory,BDI)、失眠严重程度量表(insomnia severity index,ISI)和军人社会支持评定量表(social suport rate scale for Chinese military personnel,SSRS-M)进行评估,并对血清5-羟色胺(5-hydroxytryptamine,5-HT)和脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)浓度进行测定,比较两组之间差异,通过多因素logistic回归分析了解该类人群自杀未遂的危险因素。结果与非自杀未遂组相比,自杀未遂组既往多次住院者比例更高(57.58%vs 29.63%,P<0.05)、有更多的创伤经历(66.67%vs 40.74%,P<0.05)、自杀意念更加强烈(72.73%vs 37.04%,P<0.01),且自杀计划(90.91%vs 59.26%,P<0.01)和非自杀性自伤(non-suicidal self-injury,NSSI)行为(93.94%vs 48.15%,P<0.01)更常见,差异均有统计学意义(均P<0.05);自杀未遂组SSRS-M总分明显低于非自杀未遂组[(24.85±6.48)分vs(28.70±7.15)分,P<0.05];自杀未遂组血清BDNF浓度更低[418.26(269.18,606.62)ng/L vs537.46(412.04,784.92)ng/L,P <0.05]。Logistic回归分析显示,存在NSSI行为(OR=13.06)和低血清BDNF浓度(OR=0.97)是军人精神障碍患者自杀未遂的主要危险因素(均P<0.05)。结论 NSSI行为和低血清BDNF浓度水平可能是军人精神障碍患者发生自杀未遂的独立危险因素,可将其作为防自杀早期预警信号,对军人自杀防控有重要意义。

关键词：精神障碍自杀未遂非自杀性自伤脑源性神经营养因子