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Ultra-wide band gap and wave attenuation mechanism of a novel star-shaped chiral metamaterial

Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1261-1278页

作者： Shuo WANG Anshuai WANG Yansen WU Xiaofeng LI yongtao sun Zhaozhan ZHANG Qian DING G.D.AYALEW Yunxiang MA Qingyu LIN Department of Mechanics Tianjin University Tianjin Key Laboratory of Nonlinear Dynamics and Control Tianjin University State Key Laboratory of Metastable Materials Science and Technology Yanshan University

A novel hollow star-shaped chiral metamaterial(SCM) is proposed by incorporating chiral structural properties into the standard hollow star-shaped metamaterial, exhibiting a wide band gap over 1 500 Hz. To broaden the band gap,solid single-phase and two-phase SCMs are designed and simulated, which produce two ultra-wide band gaps(approximately 5 116 Hz and 6 027 Hz, respectively). The main reason for the formation of the ultra-wide band gap is that the rotational vibration of the concave star of two novel SCMs drains the energy of an elastic wave. The impacts of the concave angle of a single-phase SCM and the resonator radius of a two-phase SCM on the band gaps are studied. Decreasing the concave angle leads to an increase in the width of the widest band gap, and the width of the widest band gap increases as the resonator radius of the two-phase SCM increases. Additionally,the study on elastic wave propagation characteristics involves analyzing frequency dispersion surfaces, wave propagation directions, group velocities, and phase velocities. Ultimately, the analysis focuses on the transmission properties of finite periodic structures. The solid single-phase SCM achieves a maximum vibration attenuation over 800, while the width of the band gap is smaller than that of the two-phase SCM. Both metamaterials exhibit high vibration attenuation capabilities, which can be used in wideband vibration reduction to satisfy the requirement of ultra-wide frequencies.

关键词： metamaterial ultra-wide band gap wave propagation vibration suppression O421 + .5 74H45

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Design and Wave Propagation Characterization of Starchiral Metamaterials

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Acta Mechanica Solida Sinica 2022年第2期35卷 215-227页

作者： Yajun Xin Han Wang Cong Wang Jinxin Yao Qian Ding Haoqiang Gao Shuliang Cheng yongtao sun Key Laboratory of Green Construction and Intelligent Maintenance for Civil Engineering of Hebei Province Yanshan UniversityQinhuangdao 060000China Hebei Province Low-Carbon and Clean Building Heating Technology Innovation Center Yanshan UniversityQinhuangdao 060000China Department of Mechanics and Tianjin Key Laboratory of Nonlinear Dynamics and Control Tianjin UniversityTianjin 300072China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China

Metamaterials with simple artificial topological properties made from industrially produced single-phase materials have extraordinary innovation and challenge.In this paper,we investigated wave propagation characteristics of a hexastarchiral lattice metamaterial with periodic assemblies and used the finite element(FE)method to study the band gap properties.Then,in order to understand the mechanism of band gaps,we discussed the mode shapes of unit cells and found that the bending of the ligament and the overall rotation have a high correlation with the generation of omnidirectional band gaps.The relationships bet ween geometric parameters and band gap properties have also been systematically studied,which demonstrated that the band gaps of the proposed metamaterial could be reasonably predicted through the evolution of geometric parameters.Finally,the transmission characteristics of finite sandwich panel structures composed of periodic unit cells were calculated to verify the correctness of the band gap simulation results,which proved that the proposed artificial metastructure has potential application value in vibration and noise reduction projects.

关键词： Hexastarchiral lattice metamaterials Band gap properties Finite element method Rotational resonance

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Nonlinear dynamic response and stability analysis of the stapes reconstruction in human middle ear

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应用数学和力学:英文版 2023年第10期44卷 1739-1760页

作者： Lele WANG Liang WANG Yueting ZHU Zhanli LIU yongtao sun Jie WANG Hongge HAN Shuyi XIANG Huibin SHI Qian DING Department of Mechanics Tianjin UniversityTianjin 300350China Tianjin Key Laboratory of Nonlinear Dynamics and Control Tianjin UniversityTianjin 300350China Department of Otolaryngology Head and Neck SurgeryTianjin Children's HospitalTianjin UniversityTianjin 300400China School of Aerospace Engineering Tsinghua UniversityBeijing 100084China Department of Otolaryngology Head and Neck Surgery Beijing Tongren HospitalCapital Medical UniversityBeijing 100730China Key Laboratory of Otolaryngology Head and Neck Surgery Ministry of EducationBeijing 100730China Beijing Engineering Research Center of Audiological Technology Beijing 100730China

Stapes fracture causes hearing loss and instability in the middle ear hearing system(MEHS). The material used in the stapes reconstruction restores stapes, but the effects of the nonlinear material parameters on the stability of the MEHS are still unknown. To address this challenge, the nonlinear dynamic response and stability of the stapes reconstruction are investigated using a multi-degree-of-freedom mechanical model. The material parameters of the implant are tentatively determined by analyzing the natural frequencies of the undamped system. The dynamical properties of the MEHS are characterized under different external excitations. The approximate solution of the MEHS near the resonant frequency is derived through the multiple-time-scale method(MTSM). The results show that the nonlinear stiffness of the material has little influence on the MEHS in the healthy state, but it causes resonant phenomena between the ossicle and the implant in the pathological state.

关键词： crus fracture of stapes stapes reconstruction dynamic analysis bifurcation analysis multiple-time-scale method(MTSM)

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Nonlinear dynamic behavior of a flexible asymmetric aero-engine rotor system in maneuvering flight

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Chinese Journal of Aeronautics 2020年第10期33卷 2633-2648页

作者： Tian GAO Shuqian CAO yongtao sun Department of Mechanics Tianjin UniversityTianjin 300354China Tianjin Key Laboratory of Nonlinear Dynamics and Control Tianjin 300354China National Demonstration Center for Experimental Mechanics Education Tianjin UniversityTianjin 300354China

Aero-engine rotor systems installed in aircraft are considered to have a base motion.In this paper,a flexible asymmetric rotor system is modeled considering the nonlinear supports of ball bearings and Squeeze Film Dampers(SFDs),and the dynamic characteristics of the rotor system under maneuvering flight are systematically studied.Effects of the translational accelerative motions,the angular motions and the pitching flight with combined translational and angular motions on nonlinear dynamic behavior of the rotor system are investigated.The results show that,due to the nonlinear coupled effects among the rotor,ball bearings and SFDs,within the first bending resonance region,responses of the rotor show obvious nonlinear characteristics such as bistable phenomenon,amplitude jumping phenomenon and non-synchronous vibration.Translational acceleration motion of the aircraft leads to axis offset of the rotor system and thus results in the reduction and the final disappearance of the bistable rotating speed region.The pitching angular motion mainly affects rotational vibration of the rotor system,and thus further induces their transverse vibrations.For the pitching flight with combined translational and angular motions,a critical flight parameter is found to correspond to the conversion of two steady responses of the rotor system,in which one response displays small amplitude and synchronous vibration,and the other shows large amplitude and non-synchronous vibration.

关键词： Aero-engine rotor system Ball bearings Maneuvering flight Nonlinear dynamics Squeeze film dampers

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Moving Toward a Functional Cure for HIV-1

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Infectious Diseases & Immunity 2021年第3期1卷 161-168页

作者： Wen Kang yongtao sun Department of Infectious Diseases Tangdu HospitalThe Fourth Military Medical UniversityXi’an 710038China

Despite the recent success of suppressing human immunodeficiency virus 1(HIV-1)replication in the peripheral blood with antiretroviral therapy,elimination of the provirus from infected cells remains challenging because the virus can integrate into the host genome and become a latent proviral reservoir.The removal of these latent viral reservoirs from tissue containing infected resting memory CD4+T cells remains a major barrier to developing a cure for HIV-1.Several novel strategies have recently been developed for curing HIV infection.These include stem cell transplantation with CCR5-D32 mutated cells,initial antiretroviral treatment in the very early stage of HIV infection,gene editing to excise the HIV genome or generate CCR5-mutated HIV-1-resistant cells,“shock-and-kill”to reactivate latent HIV using latency reversal agents combined with enhanced immune clearance methods,and an emerging“block-and-lock”strategy to reactivate latent HIV using latency reversal agents combined with enhanced immune clearance methods.However,the high risks and limitations to scale-up in clinics,as well as poor performance in clinical trials,have hampered these efforts.This review aims to describe the present efforts that are being made to combat HIV latency,and critically discuss the limitations and future of the cure for HIV-1.

关键词： HIV Block-and-lock Deep latency HIV latency Shock-and-kill Transcriptional reactivation

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Dynamic web service composition based on OWL-S

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Science in China(Series F) 2006年第6期49卷 843-863页

作者： Jing DONG yongtao sun Sheng YANG Kang ZHANG Department of Computer Science University of Texas at Dallas Richardson TX 75083 USA American Airlines 4333 Amon Carter Blvd Fort Worth TX 76155 USA

Composing existing web services for enterprise applications may enable higher level of reuse. However the composition processes are mostly static and lack of support for runtime redesign. In this paper, we describe our approach to the extension of the OWL-S ontology framework for dynamic web service composition. We raise the level of abstraction and propose an abstract service layer so that web services can be composed at the abstract service level instead of the concrete level. Each abstract service is attached with an instance pool including all instances of the abstract service to facilitate fail-over and dynamic compositions.

关键词： web service instance pool abstract service ontology dynamic composition

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3.5%NaCl环境中S32205双相不锈钢与N09925镍基合金的钝化膜特征及耐蚀性

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腐蚀与防护 2024年第6期45卷 15-20页

作者：卢道胜刘慧枫孙永涛董社霞杜宇峰林学强中海油田服务股份有限公司天津分公司天津300451 中国石油大学(华东)材料科学与工程学院青岛266580

采用莫特肖特基(Mott-Schottky)分析方法、电化学阻抗谱(EIS)和X射线光电子能谱(XPS)等,对比研究了S32205双相不锈钢和N09925镍基合金在3.5%NaCl溶液中的钝化膜特征和耐蚀性。结果表明:N09925镍基合金表面钝化膜的缺陷密度低于S32205双... 详细信息

采用莫特肖特基(Mott-Schottky)分析方法、电化学阻抗谱(EIS)和X射线光电子能谱(XPS)等,对比研究了S32205双相不锈钢和N09925镍基合金在3.5%NaCl溶液中的钝化膜特征和耐蚀性。结果表明:N09925镍基合金表面钝化膜的缺陷密度低于S32205双相不锈钢,两种材料表面的钝化膜中均存在Fe和Cr元素富集,主要成分为Cr和Fe的氧化物和氢氧化物;S32205双相不锈钢表面钝化膜中含有少量金属Ni,N09925镍基合金表面钝化膜中Ni含量较高,还含有Ni的氧化物和氢氧化物;N09925镍基合金的阻抗值更高,其膜层电阻和电荷传递电阻均高于S32205双相不锈钢,N09925镍基合金表面钝化膜的保护性高于S32205双相不锈钢。

关键词： S32205双相不锈钢 N09925镍基合金钝化膜电化学测试 X射线光电子能谱(XPS)

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HBsAg Loss with Peg-interferon Alfa-2a in Hepatitis B Patients with Partial Response to Nucleos(t)ide Analog:New Switch Study

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Journal of Clinical and Translational Hepatology 2018年第1期6卷 25-34页

作者： Peng Hu Jia Shang Wenhong Zhang Guozhong Gong Yongguo Li Xinyue Chen Jianning Jiang Qing Xie Xiaoguang Dou yongtao sun Yufang Li Yingxia Liu Guozhen Liu Dewen Mao Xiaoling Chi Hong Tang Xiaoou Li Yao Xie Xiaoping Chen Jiaji Jiang Ping Zhao Jinlin Hou Zhiliang Gao Huimin Fan Jiguang Ding Dazhi Zhang Hong Ren Department of Infectious Diseases The Second Affiliated Hospital of Chongqing Medical UniversityChongqingChina Department of Infectious Diseases Henan Provincial People's HospitalZhengzhouChina Department of Infectious Diseases Huashan HospitalFudan UniversityShanghaiChina Department of Infectious Diseases The Second Xiangya Hospital of Central South UniversityChangshaChina Department of Infectious Diseases The First Affiliated Hospital of Harbin Medical UniversityHarbinChina International Medical Department Beijing YouAn HospitalCapital Medical UniversityBeijingChina Department of Infectious Diseases The First Affiliated Hospital of Guangxi Medical UniversityNanningChina Department of Infectious Diseases Ruijin HospitalShanghai Jiaotong University School of MedicineShanghaiChina Department of Infectious Diseases Shengjing Hospital of China Medical UniversityShenyangChina Department of Infectious Diseases Tangdu HospitalFourth Military Medical UniversityXi'anChina Department of Infectious Diseases General Hospital of Ningxia Medical UniversityYinchuanChina Department of Infectious Diseases Shenzhen Third People's HospitalShenzhenChina Department of Infectious Diseases Xiangya Hospital Central South UniversityChangshaChina Liver Disease Department The First Affiliated Hospital of Guangxi University of Chinese MedicineNanningChina Liver Disease Department Guangdong Hospital of Traditional Chinese MedicineGuangzhouChina Center of Infectious Diseases West China HospitalSichuan UniversityChengduChina Liver Disease Department The Sixth People's Hospital of HangzhouZhejiangChina Liver Disease Department Beijing Ditan HospitalCapital Medical UniversityBeijingChina Department of Infectious Diseases Guangdong General HospitalGuangzhouChina Center of Liver Diseases The First Affiliated Hospital of Fujian Medical UniversityFuzhouChina International Center for Liver Disease Treatment 302 Hospital of PLABeijingChina Department of Infectious Diseases and Hepatology Unit Nanfang Ho

Background and Aims:Hepatitis B surface antigen(HBsAg)loss is seldom achieved with nucleos(t)ide analog(NA)therapy in chronic hepatitis B patients but may be enhanced by switching to finite pegylated-interferon(Peg-IFN)alfa-2a.We assessed HBsAg loss with 48-and 96-week Peg-IFN alfa-2a in chronic hepatitis B patients with partial response to a previous NA.Methods:Hepatitis B e antigen(HBeAg)-positive patients who achieved HBeAg loss and hepatitis B virus DNA<200 IU/mL with previous adefovir,lamivudine or entecavir treatment were randomized 1:1 to receive Peg-IFN alfa-2a for 48(n=153)or 96 weeks(n=150).The primary endpoint of this study was HBsAg loss at end of treatment.The ClinicalTrials.gov identifier is NCT01464281.Results:At the end of 48 and 96 weeks'treatment,14.4%(22/153)and 20.7%(31/150)of patients,respectively,who switched from NA to Peg-IFN alfa-2a cleared HBsAg.Rates were similar irrespective of prior NA or baseline HBeAg seroconversion.Among those who cleared HBsAg by the end of 48 and 96 weeks'treatment,77.8%(14/18)and 71.4%(20/28),respectively,sustained HBsAg loss for a further 48 weeks.Baseline HBsAg<1500 IU/mL and week 24 HBsAg<200 IU/mL were associated with the highest rates of HBsAg loss at the end of both 48-and 96-week treatment(51.4%and 58.7%,respectively).Importantly,extending treatment from 48 to 96 weeks enabled 48.3%(14/29)more patients to achieve HBsAg loss.Conclusions:Patients on long-term NA who are unlikely to meet therapeutic goals can achieve high rates of HBsAg loss by switching to Peg-IFN alfa-2a.HBsAg loss rates may be improved for some patients by extending treatment from 48 to 96 weeks,although the differences in our study cohort were not statistically significant.Baseline and on-treatment HBsAg may predict HBsAg loss with Peg-IFN alfa-2a.

关键词： Antiviral therapy Peg-interferon Nucleos(t)ide treated Chronic hepatitis B

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Defined organic-octamolybdate crystalline superstructures derived Mo_(2)C@C as efficient hydrogen evolution electrocatalysts

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Chinese Chemical Letters 2024年第6期35卷 201-205页

作者： Jiao Li Chenyang Zhang Chuhan Wu Yan Liu Xuejian Zhang Xiao Li yongtao Li Jing sun Zhongmin Su School of Materials Science and Engineering Jilin Jianzhu UniversityChangchun 130018China School of Chemical and Environmental Engineering Changchun University of Science and TechnologyChangchun 130022China

Hydrogen evolution electrocatalysts derived from metal-organic crystalline frameworks can inherit the merits of ordered and adjustable structures with high surface area.In this paper,organic-octamolybdate crystalline superstructures(OOCS)with a fixed stoichiometric ratio of Mo_(8)(L)_(2) and high Mo content(>40 wt%)were synthesized using flexible ligands with controllable lengths(named as OOCS-1-3).Then,molybdenum carbides coated with carbon layers as electrocatalysts(Mo_(2)C@C-1-3)can be obtained directly from a one-step high-temperature carbonization process using OOCS-1-3 as precursors.As a typical example,Mo_(2)C@C-3 exhibits satisfactory hydrogen evolution activity with a low overpotential of 151 m V(1.0 mol/L KOH)at 10 m A/cm^(2) and stability for 24 h.The electrocatalytic activity is mainly from the synergistic interactions between the carbon layers and molybdenum carbide species.Furthermore,compared with the initial content of C,N,Mo in OOCS and Mo_(2)C@C,the catalytic activity increases with the N amount.This work makes organic-octamolybdate crystalline superstructures used as general precursors to product high Mo content electrocatalysts applied in energy storage and conversion fields.

关键词： Molybdenum carbides Electrocatalysts Organic-octamolybdate crystalline superstructures Synergistic interactions Hydrogen evolution reaction(HER)

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氧化锌纳米颗粒和四环素复合胁迫对好氧颗粒污泥处理低碳源废水的影响

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水处理技术 2024年第7期50卷 66-71,78页

作者：孙熠李永涛四川交通职业技术学院 611130 西南石油大学四川成都610500

为明确新污染物氧化锌纳米颗粒(ZnO NP)和四环素抗生素(TCA)复合胁迫对好氧颗粒物污泥处理低C/N废水的影响,构建了小试规模的颗粒污泥反应器,探究了ZnO NP和TCA复合影响对AGS处理低C/N废水的影响,分析了出水水质、污泥特征及微生物群落... 详细信息

为明确新污染物氧化锌纳米颗粒(ZnO NP)和四环素抗生素(TCA)复合胁迫对好氧颗粒物污泥处理低C/N废水的影响,构建了小试规模的颗粒污泥反应器,探究了ZnO NP和TCA复合影响对AGS处理低C/N废水的影响,分析了出水水质、污泥特征及微生物群落特征的变化,揭示了ZnO NP和TCA复合胁迫对AGS的影响机制。结果表明,ZnO NP和TCA复合胁迫对AGS处理低C/N废水具有拮抗作用。ZnO NP和TCA复合暴露组别内,出水COD和溶解性磷酸盐(SOP)浓度分别为42.8~53.4 mg/L和1.95~2.36 mg/L,对应去除效率分别下降至75.1%~78.5%和70.3%~75.6%,远低于ZnO NP和TCA单一暴露组别。ZnO NP和TCA复合胁迫降低了AGS污泥浓度总固体(TS)至5.5~5.8 g/L,挥发性固体/TS至0.61~0.64,但刺激胞外聚合物(EPS)含量至91.6~93.4 mg/g。此外,ZnO NP和TCA复合胁迫提高了EPS内蛋白质(PN)和多糖(PS)含量,并提高PN/PS。酶活性分析表明ZnO NP和TCA复合胁迫降低了与污染物和营养盐去除相关的关键酶活性。微生物群落结构分析ZnO NP和TCA复合胁迫降低了属水平上与反硝化相关的Tsukamurella、unclassified f_Comamonadaceae、Micropruina和Microbacterium的相对丰度。ZnO NP和TCA复合胁迫产生的生态毒性对AGS具有严重影响。研究结果为理解新污染物ZnO NP和TCA复合胁迫的环境风险具有一定的理论意义。

关键词：好氧颗粒污泥氧化锌纳米颗粒四环素微生物群落

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