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Strain Growth in Containment Vessels

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Transactions of Tianjin University 2006年第B09期12卷 193-198页

作者： DONG q LI q M ZHENG j Y School of Mechanical Aerospace and Civil Engineering The University of Manchester PO Box 88 Manchester M60 1QD UK Institute of Chemical Machinery Zhejiang University Hangzhou 310027 China

Strain growth is a phenomenon observed in containment vessels subjected to internal blast loading. The elastic response of the vessel may become larger in a later stage compared to its response during the initial stage. The dynamic responses of infinitely long cylindrical containment vessels subjected to uniformly-distributed internal blast loading are studied using LS-DYNA. The development of bending modes and the interaction between the breathing mode and bending modes are observed. The methodology developed for dynamic elastic buckling analysis is employed to study the strain growth phenomenon in explosion containment vessels. It is shown that the dynamic instable vibration of a containment vessel is the basic mechanism of strain growth.

关键词： strain growth containment vessel dynamic response impulsive loading

Universal basis underlying temperature, pressure and size induced dynamical evolution in metallic glass-forming liquids

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Chinese Physics B 2024年第1期33卷 134-142页

作者：张华平范蓓蓓吴佳琦李茂枝 Department of Physics Beijing Key Laboratory of Opto-electronic Functional Materials&Micro-nano DevicesRenmin University of ChinaBeijing 100872China Songshan Lake Materials Laboratory Dongguan 523808China Key Laboratory of quantum State Construction and Manipulation Renmin University of ChinaBeijing 100872China

The dramatic temperature-dependence of liquids dynamics has attracted considerable scientific interests and efforts in the past decades, but the physics of which remains elusive. In addition to temperature, some other parameters, such as pressure, loading and size, can also tune the liquid dynamics and induce glass transition, which makes the situation more complicated. Here, we performed molecular dynamics simulations for Ni_(50)Zr_(50) bulk liquid and nanodroplet to study the dynamics evolution in the complex multivariate phase space, especially along the isotherm with the change of pressure or droplet size. It is found that the short-time Debye–Waller factor universally determines the long-time relaxation dynamics no matter how the temperature, pressure or size changes. The basic correlation even holds at the local atomic scale. This finding provides general understanding of the microscopic mechanism of dynamic arrest and dynamic heterogeneity.

关键词： metallic glass-forming liquids structure relaxation dynamical heterogeneity Debye–Waller factor

Enhanced angiogenesis in porous poly(ε-caprolactone) scaffolds fortified with methacrylated hyaluronic acid hydrogel after subcutaneous transplantation

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Biomaterials Translational 2024年第1期5卷 59-68页

作者： Yang H. Zheng M. Zhang Y. Li C. Lai j.H.C. Zhang q. Chan K.W.Y. Wang H. Zhao X. Yang Z. Xu C. Department of Biomedical Engineering City University of Hong Kong Hong Kong Center for Pluripotent Stem Cell Research and Engineering Research Institute of Tsinghua Guangdong Province Guangzhou China Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic University Hong Kong

A composite scaffold composed of a porous scaffold and hydrogel filling can facilitate engraftment, survival, and retention in cell transplantation processes. This study presents a composite scaffold made of poly(ε-caprolactone) (PCL) and methacrylated hyaluronic acid (MeHA) hydrogel and describes the corresponding physical properties (surface area, porosity, and mechanical strength) and host response (angiogenesis and fibrosis) after subcutaneous transplantation. Specifically, we synthesise MeHA with different degrees of substitution and fabricate a PCL scaffold with different porosities. Subsequently, we construct a series of PCL/MeHA composite scaffolds by combining these hydrogels and scaffolds. In experiments with mice, the scaffold composed of 3% PCL and 10–100 kDa, degree of substitution 70% MeHA results in the least fibrosis and a higher degree of angiogenesis. This study highlights the potential of PCL/MeHA composite scaffolds for subcutaneous cell transplantation, given their desirable physical properties and host response. © 2024, Chinese Medical Multimedia Press Co Ltd. All rights reserved.

关键词： angiogenesis cell transplantation hyaluronic acid poly(ε-caprolactone) scaffold

新型含(卤代)烷氧基类双酰胺化合物的合成、杀虫活性及构效关系研究

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有机化学 2024年第5期44卷 1584-1591页

作者：刘吉永吴明慧相君成庞怀林李斌吕亮沈阳农业大学植物保护学院沈阳110866 南通泰禾化工股份有限公司江苏南通226407 上海晓明检测技术服务有限公司上海200335

为了发现结构新颖、活性优异、环境友好的新型杀虫剂,以环丙氟虫胺为先导化合物,在其苯胺部分引入(卤代)烷氧基单元,设计合成了一系列未见文献报道的新型含(卤代)烷氧基类双酰胺化合物,其结构经过^(1)H NMR、^(13)C NMR和HRMS确证.初步... 详细信息

为了发现结构新颖、活性优异、环境友好的新型杀虫剂,以环丙氟虫胺为先导化合物,在其苯胺部分引入(卤代)烷氧基单元,设计合成了一系列未见文献报道的新型含(卤代)烷氧基类双酰胺化合物,其结构经过^(1)H NMR、^(13)C NMR和HRMS确证.初步的生物活性测试结果表明,大部分化合物对小菜蛾表现出优异的杀虫活性,其中N-[2-溴-4-(全氟丙烷-2-基)-6-(二氟甲氧基)苯基]-3-[N-(环丙甲基)苯甲酰胺基]-4-氟苯甲酰胺(4a)、N-[2-溴-4-(全氟丙烷-2-基)-6-(三氟甲氧基)苯基]-3-[N-(环丙甲基)苯甲酰胺基]-4-氟苯甲酰胺(4b)、N-(2-溴-6-(二氟甲氧基)-4-(全氟丙烷-2-基)苯基)-3-(N-(环丙基甲基)苯甲酰胺基)-2-氟苯甲酰胺(4h)、N-[2-溴-6-(二氟甲氧基)-4-(全氟丙烷-2-基)苯基]-3-[4-氰基-N-(环丙基甲基)苯甲酰胺]-2-氟苯甲酰胺(4j)~N-(3-((2-溴-6-(二氟甲氧基)-4-(全氟丙烷-2-基)苯基)氨基甲酰基)-2-氟苯基)-N-(环丙基甲基)异烟酰胺(4o)、N-(3-((2-溴-6-(二氟甲氧基)-4-(全氟丙烷-2-基)苯基)氨基甲酰基)-2-氟苯基)-N-(环丙基甲基)-2,4-二氟苯甲酰胺(4q)和N-(3-((2-溴-6-(二氟甲氧基)-4-(全氟丙烷-2-基)苯基)氨基甲酰基)-2-氟苯基)-N-(环丙基甲基)-2-氟异烟酰胺(4t)在1mg/L浓度下显示出100%的杀虫活性.同时,化合物4a不仅对小菜蛾和二化螟的杀虫活性接近于环丙氟虫胺,而且对苜蓿蚜和朱砂叶螨的杀虫活性也较高,表现出比环丙氟虫胺更广的杀虫谱,其田间试验正在进行中.

关键词：双酰胺化合物合成杀虫活性构效关系

Novel method for random vibration analysis of single-degree-of-freedom vibroimpact systems with bilateral barriers

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Applied Mathematics and Mechanics(English Edition) 2019年第12期40卷 1759-1776页

作者： Lincong CHEN Haisheng ZHU j.q.SUN College of Civil Engineering Huaqiao UniversityXiamen 361021Fujian ProvinceChina School of Engineering University of CaliforniaMercedCA 95343U.S.A

The vibroimpact systems with bilateral barriers are often encountered in ***,the dynamics of the vibroimpact system with bilateral barriers is full of *** closed-form solutions were *** this paper,we propose a novel method for random vibration analysis of single-degree-of-freedom(SDOF)vibroim-pact systems with bilateral barriers under Gaussian white noise excitations.A periodic approximate transformation is employed to convert the equations of the motion to a con-tinuous *** probabilistic description of the system is subsequently defined through the corresponding Fokker-Planck-Kolmogorov(FPK)*** closed-form station-ary probability density function(PDF)of the response is obtained by solving the reduced FPK equation and using the proposed iterative method of weighted residue together with the concepts of the circulatory probability flow and the potential probability ***,the versatility of the proposed approach is demonstrated by its application to two typical *** that the solution obtained by using the proposed method can be used as the benchmark to examine the accuracy of approximate solutions obtained by other methods.

关键词： bilateral barrier vibroimpact system weighted residue method iterative random vibration

Macroscopic and microscopic mechanical behaviors of climbing tendrils

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Acta Mechanica Sinica 2019年第3期35卷 702-710页

作者： q.Guo j.j.Dong Y.Liu X.H.Xu q.H.qin j.S.Wang Tianjin Key Laboratory of Modern Engineering Mechanics Department of MechanicsTianjin UniversityTianjin 300054China State Key Laboratory of Nonlinear Mechanics (LNM) Institute of MechanicsChinese Academy of ScienceBeijing 100080China Research School of Engineering Australian National UniversityCanberraACT 2601Australia

Tendril-bearing climbing plants must recur to the tendril helices with chiral perversion or dual chirality for climbing and to obtain sun exposure. Despite researchers' prolonged fascination with climbing tendrils since Darwin's time and even earlier, why the soft and slender tendrils can bear heavy loads such as the self-weight of a plant or additional load caused by rain remains elusive. In this paper, we take towel gourd tendrils as an example and investigate the macroscopic and microscopic mechanical behaviors of tendrils through experiments and simulations. Our study indicates that the tendril filament exhibits rubber-like hyperelastic behaviors and can particularly endure large elongation, which is mainly attributed to the superelasticity of the cellulose fibril helix contained in the cell wall. Combination of the tendril helical structure with dual chirality or chiral perversion at a macroscale and a cellulose filament helix at a subcellular level creates superior elasticity for biological species relying on support and climbing. This study provides deep insight into the structure-property relationship of climbing tendrils, and the relationship is useful for the bioinspired design of composite systems with superior elasticity.

关键词： Climbing tendril Mechanical behaviors Structure-property relationship Large elongation

A subspace expanding technique for global zero finding of multi-degree-of-freedom nonlinear systems

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Applied Mathematics and Mechanics(English Edition) 2020年第5期41卷 769-784页

作者： Zigang LI jun jIANG LingHONG j.q.SUN Department of Mechanics School of ScienceXi’an University of Science and TechnologyXi’an 710054China State Key Laboratory for Strength and Vibration Xi’an Jiaotong UniversityXi’an 710049China Department of Mechanical Engineering School of EngineeringUniversity of CaliforniaMercedCA 95343U.S.A.

A subspace expanding technique(SET) is proposed to efficiently discover and find all zeros of nonlinear functions in multi-degree-of-freedom(MDOF) engineering systems by discretizing the space into smaller subdomains, which are called cells. The covering set of the cells is identified by parallel calculations with the root bracketing method. The covering set can be found first in a low-dimensional subspace, and then gradually extended to higher dimensional spaces with the introduction of more equations and variables into the calculations. The results show that the proposed SET is highlyefficient for finding zeros in high-dimensional spaces. The subdivision technique of the cell mapping method is further used to refine the covering set, and the obtained numerical results of zeros are accurate. Three examples are further carried out to verify the applicability of the proposed method, and very good results are achieved. It is believed that the proposed method will significantly enhance the ability to study the stability, bifurcation,and optimization problems in complex MDOF nonlinear dynamic systems.

关键词： spatial discretization subspace expanding technique(SET) parallel computing subdivision global zero finding

A highly-efficient method for stationary response of multi-degree-of-freedom nonlinear stochastic systems

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Applied Mathematics and Mechanics(English Edition) 2020年第6期41卷 967-982页

作者： Lincong CHEN j.q.SUN College of Civil Engineering Huaqiao UniversityXiamen 361021Fujian ProvinceChina Key Laboratory for Intelligent Infrastructure and Monitoring of Fujian Province Jimei Avenue 668Xiamen 361021Fujian ProvinceChina Department of Mechanical Engineering School of EngineeringUniversity of CaliforniaMercedCA 95343U.S.A.

Analytical and numerical studies of multi-degree-of-freedom(MDOF) nonlinear stochastic or deterministic dynamic systems have long been a technical *** paper presents a highly-efficient method for determining the stationary probability density functions(PDFs) of MDOF nonlinear systems subjected to both additive and multiplicative Gaussian white noises. The proposed method takes advantages of the sufficient conditions of the reduced Fokker-Planck-Kolmogorov(FPK) equation when constructing the trial solution. The assumed solution consists of the analytically constructed trial solutions satisfying the sufficient conditions and an exponential polynomial of the state variables, and delivers a high accuracy of the solution because the analytically constructed trial solutions capture the main characteristics of the nonlinear system. We also make use of the concept from the data-science and propose a symbolic integration over a hypercube to replace the numerical integrations in a higher-dimensional space, which has been regarded as the insurmountable difficulty in the classical method of weighted residuals or stochastic averaging for high-dimensional dynamic systems. Three illustrative examples of MDOF nonlinear systems are analyzed in detail. The accuracy of the numerical results is validated by comparison with the Monte Carlo simulation(MCS) or the available exact solution. Furthermore, we also show the substantial gain in the computational efficiency of the proposed method compared with the MCS.

关键词： stationary response multi-degree-of-freedom(MDOF)nonlinear system Fokker-Planck-Kolmogorov(FPK)equation least square method

共享社会经济路径(SSP1~5)中国及分省经济预估数据集_v2

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气候变化研究进展 2024年第4期20卷 498-503页

作者：杨聿铭翟建青苏布达景丞姜彤郭欢欢南京信息工程大学地理科学学院/灾害风险管理研究院南京210044 南京信息工程大学气候与环境治理研究院南京210044 中国气象局国家气候中心北京100081 中国科学院新疆生态与地理研究所荒漠与绿洲生态国家重点实验室乌鲁木齐830011 江苏第二师范学院地理科学学院南京210013

随着全球经济快速增长,特别是基于传统工业化模式的增长,增加了化石燃料的使用,造成气候变暖和极端天气事件增加[1]。在追求短期经济利益的压力下,一些政府可能忽视或延迟实施必要的环境保护和气候治理措施。加之快速城市化和工业化导... 详细信息

随着全球经济快速增长,特别是基于传统工业化模式的增长,增加了化石燃料的使用,造成气候变暖和极端天气事件增加[1]。在追求短期经济利益的压力下,一些政府可能忽视或延迟实施必要的环境保护和气候治理措施。加之快速城市化和工业化导致对煤炭、石油等化石能源的需求激增,温室气体大量排放,气候进一步恶化,气候治理的难度加大。快速经济增长常常伴随着对自然资源的消耗,包括水资源、森林、矿产等,这不仅直接破坏了自然环境,还会降低这些生态系统对气候变化的适应能力和减缓作用。气候风险研究在应对气候变化方面发挥着关键作用,它包括对未来气候条件的预估,评估气候变化对环境、经济和社会的潜在影响,以及制定适应和减缓气候变化的策略。

关键词：工业化模式未来气候极端天气事件气候变化化石燃料气候治理环境保护快速城市化