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Grating‐like anechoic layer for broadband underwater sound absorption

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International journal of Mechanical System Dynamics 2022年第3期2卷 265-277页

作者： Chenlei Yu Mingyu Duan Wei He Xin Chen Fengxian Xin Tian j.lu State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi'an Jiaotong UniversityXi'anChina MOE Key Laboratory for Multifunctional Materials and Structures School of Aerospace EngineeringXi'an Jiaotong UniversityXi'anChina Department of Advanced Manufacturing and Robotics College of EngineeringPeking UniversityBeijingChina Xi'an Modern Chemistry Research Institute Xi'anChina State Key Laboratory for Mechanics and Control of Mechanical Structures College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjingChina MIIT Key Laboratory of Multifunctional Lightweight Materials and Structures College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjingChina

To address the challenging task of effective sound absorption in the low and broad frequency band for underwater structures,we propose a novel grating‐like anechoic layer by filling rubber blocks and an air backing layer into metallic *** metallic gratings are incorporated into the anechoic layer as a skeleton for enhanced viscoelastic dissipation by promoting shear deformation between rubber and metal *** introduction of an air backing layer releases the bottom constraint of the rubber,thus intensifying its deformation under acoustic *** on the homogenization method and the transfer matrix method,a theoretical model is developed to evaluate the sound absorption performance of the proposed anechoic layer,which is validated against finite element simulation *** is demonstrated that a sound absorption coefficient of the grating‐like anechoic layer of 0.8 can be achieved in the frequency range of 1294-10000 *** the importance of sound absorption at varying frequencies,the weighted average method is subsequently used to comprehensively evaluate the performance of the anechoic ***,with structural density taken into consideration,an integrated index is proposed to further evaluate the acoustic properties of the proposed anechoic ***,the backing conditions and the boundary conditions of finite‐size structures are *** results provide helpful theoretical guidance for designing novel acoustic metamaterials with broadband low‐frequency underwater sound absorption.

关键词： underwater sound absorption broadband transfer matrix method rubber coating

Hardness-thermal stability synergy in nanograined Ni and Ni alloys:Superposition of nanotwin and low-energy columnar boundary

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journal of Materials Science & Technology 2023年第6期137卷 123-131页

作者： F.H.Duan Y.Lin Q.Li j.H.luan j.lu j.Pan Y.Li Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Laboratory of Nanomaterials&Nanomechanics Department of Mechanical EngineeringCity University of Hong KongHong KongChina State Key Laboratory of Material Processing and Die&Mould Technology and School of Materials Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China Department of Materials Science and Engineering City University of Hong KongHong KongChina Centre for Advanced Structural Materials Greater Bay Joint DivisionShenyang National Laboratory for Materials ScienceCity University of Hong Kong Shenzhen Research InstituteShenzhen 518057China City U-Shenzhen Futian Research Institute Shenzhen 518045China

Refining grains into nanoscale can significantly strengthen and harden metallic materials;however,nanograined metals generally exhibit low thermal stability,hindering their practical *** this work,we exploit the superposition of the contribution of nanotwins,low-angle grain boundaries,and microalloying to tailor superior combinations of high hardness and good thermal stability in Ni and Ni *** the nanotwinned Ni having a twin thickness of∼2.9 nm and grain size of 28 nm,it exhibits a hardness over 8.0 GPa and an onset coarsening temperature of 623 K,both of which are well above those of nanograined ***/Mo microalloying can further improve the onset coarsening temperature to 773 K without comprising *** analyses reveal that high hardness is achieved via strengthen-ing offered by extremely fine ***,the superior thermal stability is mainly ascribed to the low driving force for grain growth induced by the low-angle columnar boundary architecture and to the additional pinning effect on the migration of twin/columnar boundaries provided by minor Re/Mo *** present work not only reveals a family of nanotwinned metals possessing the combination of ultra-high hardness and high thermal stability but also provides a strategy for tailoring properties of metallic materials by pairing low-angle grain boundaries and twin boundaries.

关键词： Nanotwin Thermal stability Hardness Low-angle grain boundary Microalloying

The combined effects of grain and sample sizes on the mechanical properties and fracture modes of gold microwires

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journal of Materials Science & Technology 2019年第1期35卷 76-83页

作者： H.K.Yang K.Cao Y.Han M.Wen j.M.Guo Z.L.Tan j.lu Y.lu Hong Kong Branch of National Precious Metals Material Engineering Research Center City University of Hong Kong Department of Mechanical and Biomedical Engineering City University of Hong Kong State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals Sino-platinum Metals Co.Ltd Center for Advanced Structural Materials City University of Hong Kong Shenzhen Research Institute

Hall-Petch relation was widely applied to evaluate the grain size effect on mechanical properties of metallic material. However, the sample size effect on the Hall-Petch relation was always ignored. In the present study, the mechanical test and microstructure observation were performed to investigate the combined effects of grain and sample sizes on the deformation behaviors of gold microwires. The polycrystalline gold microwires with diameter of 16 ?m were annealed at temperatures from 100°C to 600°C, leading to different ratios(t/d) of wire diameter(t) to grain size(d) from 0.9 to 16.7. When the t/d was lower than 10, the yield stress dropped fast and deviated from the Hall-Petch relation. The free-surface grains played key role in the yield stress softening, and the volume fraction of free-surface grains increased with the t/d decreasing. Furthermore, the effects of t/d on work-hardening behaviors and fracture modes were also studied. With t/d value decreasing from 17 to 3.4, the samples exhibited necking fracture and the dislocation pile-ups induced work-hardening stage was gradually *** the t/d value further decreasing(t/d lure, and the work-hardening capability lost. As the gold microwire for wire bonding is commonly applied in the packaging of integrated circuit chips, and the fabrication of microwire suffers multi-pass cold-drawing and annealing treatments to control the grain size. The present study could provide instructive suggestion for gold microwire fabrication and bonding processes.

关键词： Gold microwire Wire bonding Tensile testing Grain size Hall-Petch relationship

Carbon ion radiotherapy boost in the treatment of glioblastoma:a randomized phase Ⅰ/Ⅲ clinical trial

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Cancer Communications 2019年第1期39卷 39-50页

作者： Lin Kong jing Gao jiyi Hu Rong lu jing Yang Xianxin Qiu Weixu Hu jiade j.lu Department of Radiation Oncology Shanghai Proton and Heavy Ion CenterFudan University Shanghai Cancer CenterShanghai 201321P.R.China Department of Radiation Oncology Shanghai Proton and Heavy Ion CenterPudong4365 Kangxin RoadShanghai 201321P.R.China

Background: Glioblastoma (GBM) is a highly virulent tumor of the central nervous system, with a median survival < 15 months. Clearly, an improvement in treatment outcomes is needed. However, the emergence of these mal... 详细信息

Background: Glioblastoma (GBM) is a highly virulent tumor of the central nervous system, with a median survival luoro-ethyl-tyrosine positron emission tomography [MET/FET PET] or magnetic resonance imaging [MRI] and detection of serologic immune markers). We hypothesize that the induction CIRT boost will result in a greater initial tumor-killing ability and prime the tumor microenvironment for enhanced immunologic tumor clearance, resulting in an expected 33% improvement in OS rates. Discussion: The prognosis of GBM remains grim. The mechanism underpin

关键词： Glioblastoma Anaplastic astrocytoma Carbon ion radiotherapy Proton radiotherapy Temozolomide Overall survival Progression-free survival Toxicity Serologic immune response O-6-methylguanine-DNA methyltransferase

Delayed plasticity during spherical nanoindentation of an iron-chromium-aluminum alloy:Effect of ferric ion irradiation

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journal of Materials Science & Technology 2023年第36期167卷 228-236页

作者： Y.Zhang C.W.Li j.L.jiang j.F.Gu H.Wang Y.D.jia G.Wang X.G.An Q.Wang j.lu Institute of Materials Shanghai UniversityShanghai 200072China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Department of Mechanical Engineering City University of Hong KongKowloonSARChina Science and Technology on Reactor Fuel and Materials Laboratory Nuclear Power Institute of ChinaChengdu 610041China Interdisciplinary Materials Research Center Institute for Advanced StudyChengdu UniversityChengdu610106China

Spherical nanoindentation of an iron-chromium-aluminum alloy was conducted to study the effect of ferric-ion(Fe 3+)irradiation on the time-dependent plasticity behavior in the surface layers of this *** was observed that the initiation of plasticity by the appearance of displacement burst or“pop-in”event occurred after a period of waiting time in the apparent elastic regime and that Fe^(3+)irradiation at 360°C and up to∼0.5 displacements per atom could make it happen under the lower applied loads but with a reduced *** the experimental data,an activation volume and activation energy were extracted for the delayed *** results show that Fe^(3+)-irradiation significantly reduced its acti-vation volume from∼3.05 b 3 to∼1.75 b 3(where b=Burgers vector),but slightly increased its activation energy from∼0.65 to∼0.71 *** the other hand,high-resolution scanning transmission electron mi-croscopy observations reveal that the irradiation at the elevated temperature created interstitial atom pair onto the(100)habit plane that can serve as the nucleation site of a100dislocation loop while elim-inating the pre-existing ***,it is indicated that heterogeneous nucleation of the dislocation loop was predominant in the delayed plasticity initiation of this alloy and that the nucleation of the interstitial-type dislocation loop was involved due to Fe^(3+)-irradiation.

关键词： Spherical nanoindentation Delayed plasticity FeCrAl alloy Fe^(3+)-irradiation

Universality of quenching-partitioning-tempering local equilibrium model

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journal of Materials Science & Technology 2022年第29期124卷 116-120页

作者： j.Z.Zhang L.Y.Zeng X.W.Zuo j.F.Wan Y.H.Rong N.Min j.lu N.L.Chen Department of Mechanical Engineering City University of Hong KongGreater Bay Joint DivisionShenyang National Laboratory for Materials ScienceTat Chee AvenueKowloonHong KongChina Shanghai Key Laboratory of Materials Laser Processing and Modification School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Laboratory for Microstructures Shanghai UniversityShanghai 201900China CityU-Shenzhen Futian Research Institute Shenzhen 518045China

*** As typical 3rd generation advanced high strength steels(AHSSs),quenching and partitioning(Q&P)steel has attracted lots of attention for excellent performance in strength-ductility[1–5].With absorbing carbon partitioning as the core idea of Q&P process,quenching-partitioning-tempering(Q-P-T)process was proposed with emphasis on precipitation strengthening for better combination of strength and ductility[6–10].

关键词： tempering strength ductility

Ultra-High Strength and Good Ductility in Nanostructured TWIP Steel by Means of Surface Mechanical Attrition Treatment

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Ultra-High Strength and Good Ductility in Nanostructured TWI...

Re-irradiation Using Intensity-Modulated Radiation Therapy of Locally Recurrent Nasopharyngeal Carcinoma

The 16th Annual Conference of Hong Kong Society of Theoretical and Applied Mechanics 2012、The 1st Mainland-Hong Kong Youth Forum on Mechanics 2012、The 8th Shanghai-Hong Kong Forum on Mechanics and Its Application 2012

作者： H.N.Kou j.lu Department of Mechanical and Biomedical Engineering City University of Hong KongHong KongChina Department of Mechanical Engineering The Hong Kong Polytechnic University

Strength and ductility are two main exclusive mechanical properties for steels and alloys. Responding to energy saving strategy and lightweight engineering,TWIP(twinning induced plasticity) steel has attracted extensive attention for its excellent combination of high strength and good *** the development of nanocrystalline materials,high strength can be obtained by grain ***,the elongation of materials usually greatly decreases at the same time. Therefore,in this study we introduced a newly developed surface mechanical attrition treatment (SMAT) technology,by which the yield strength is greatly increased in the bulk nanostructured TWIP steel and simultaneously accompanied by sufficient *** excellent mechanical properties primarily results from a variety of twinning configurations caused by severe plastic *** nanostructured TWIP steel processed by SMAT shows a great potential in optimizing strength-ductility combination for future research and its application in automobile industry.

关键词： Ultra-High Strength and Good Ductility in Nanostructured TWIP Steel by Means of Surface Mechanical Attrition Treatment

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Re-irradiation Using Intensity-Modulated Radiation Therapy o...

PhaseⅠ/Ⅱtrial evaluating concurrent carbon-ion radiotherapy plus chemotherapy for salvage treatment of locally recurrent nasopharyngeal carcinoma

第六届全国鼻咽癌学术大会

作者： Ivan WK Thmn jiade j.lu Department of Radiation Oncology National University Cancer InstituteNational University Health SystemNational University of Singapore

＜正＞Purpose:Local recurrences of nasopharyngeal carcinoma（NPC） may be salvaged by re-irradiation using conventional technique,but with significant *** modulated radiation therapy（IMRT） provides potentially improvement in therapeutic ratio by reducing dose to normal *** aim of this study is to address the efficacy and toxicity profile of IMRT for a cohort of patients with locally recurrent NPC. Methods and Materials:Between August 2003 and june 2009,seventy patients with histologically proven locally recurrent NPC were treated with *** time to recurrence was 30 months after the completion of conventional radiation to definitive ***-seven percent of the cases had rT3-4 *** minimal planned dose was 59.4-60 Gy in 1.8-2 Gy per daily fractions to the gross disease with margins,with or without chemotherapy. Results:The median dose to the tumor bed was 70 Gy（range 50-77.4 Gy）.Sixty-five patients received planned radiation therapy,and 5 patients received doses between *** a median follow-up of 25 months,the 2-,and 3-year locoregional recurrence-free,disease-free survival（DFS）,and overall survival（OS） rates were 65.8%vs.49.3%,65.8%,vs.47.6%,and 67.4%vs.51.9%,respectively. Moderate to severe late toxicities were noted in 25 patients（35.7%）.Eleven patients（15.7%） had posterior nasal space ulceration,17（24.3%） developed cranial nerve palsies,12（17.1%） had trismus,and 12（17.1%） suffered *** grade 5 toxicity *** disease-free interval and advanced T-classification at presentation were adverse prognostic factors. Conclusion:Re-irradiation with IMRT provides reasonable long-term control in patients with locally recurrent NPC with acceptable profile of adverse-effects.

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Chinese journal of Cancer 2016年第12期35卷 743-753页

作者： Lin Kong jing Gao jiyi Hu Weixu Hu Xiyin Guan Rong lu jiade j.lu Department of Radiation Oncology Shanghai Proton and Heavy Ion CenterFudan University Shanghai Cancer HospitalShanghai 200321P.R.China. Department of Radiation Oncology Shanghai Proton and Heavy Ion CenterShanghai 200321P.R.China. Department of Outpatient Clinic Shanghai Proton and Heavy Ion CenterShanghai 200321P.R.China. Shanghai Proton and Heavy Ion Center 4365 Kangxin RoadPudongShanghai 201315P.R.China.

Background: After deinitive chemoradiotherapy for non-metastatic nasopharyngeal carcinoma(NPC), more than 10% of patients will experience a local recurrence. Salvage treatments present signiicant challenges for locally recurrent NPC. Surgery, stereotactic ablative body radiotherapy, and brachytherapy have been used to treat locally recurrent NPC. However, only patients with small-volume tumors can beneit from these treatments. Re-irradiation with X-ray—based intensity-modulated radiotherapy(IMXT) has been more widely used for salvage treatment of locally recurrent NPC with a large tumor burden, but over-irradiation to the surrounding normal tissues has been shown to cause frequent and severe toxicities. Furthermore, locally recurrent NPC represents a clinical entity that is more radioresistant than its primary counterpart. Due to the inherent physical advantages of heavy-particle therapy, precise dose delivery to the target volume(s), without exposing the surrounding organs at risk to extra doses, is highly feasible with carbon-ion radiotherapy(CIRT). In addition, CIRT is a high linear energy transfer(LET) radiation and provides an increased relative biological efectiveness compared with photon and proton radiotherapy. Our prior work showed that CIRT alone to 57.5 Gy E(gray equivalent), at 2.5 Gy E per daily fraction, was well tolerated in patients who were previously treated for NPC with a deinitive dose of IMXT. The short-term response rates at 3–6 months were also acceptable. However, no patients were treated with concurrent chemotherapy. Whether the addition of concurrent chemotherapy to CIRT can beneit locally recurrent NPC patients over CIRT alone has never been addressed. It is possible that the beneits of high-LET CIRT may make radiosensitizing chemotherapy unnecessary. We therefore implemented a phase I/II clinical trial to address these questions and present our methodology and *** and design: The maximal tolerated dose(MTD) of re-treatment usi

关键词： Recurrent nasopharyngeal cancer Carbon ion radiotherapy Re-irradiation Salvage therapy Chemotherapy