检索结果-南通市图书馆

Theoretical and experimental investigation of the resonance responses and chaotic dynamics of a bistable laminated composite shell in the dynamic snap-through mode

引用

Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 581-602页

作者： Meiqi WU Pengyu LV Hongyuan LI Jiale YAN huiling duan Wei ZHANG State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering ScienceBIC-ESATCollege of EngineeringPeking UniversityBeijing 100871China Nanchang Innovation Institute of Peking University Nanchang 330096China Department of Mechanics Guangxi UniversityNanning 530004China

The dynamic model of a bistable laminated composite shell simply supported by four corners is further developed to investigate the resonance responses and chaotic behaviors.The existence of the 1:1 resonance relationship between two order vibration modes of the system is verified.The resonance response of this class of bistable structures in the dynamic snap-through mode is investigated,and the four-dimensional(4D)nonlinear modulation equations are derived based on the 1:1 internal resonance relationship by means of the multiple scales method.The Hopf bifurcation and instability interval of the amplitude frequency and force amplitude curves are analyzed.The discussion focuses on investigating the effects of key parameters,e.g.,excitation amplitude,damping coefficient,and detuning parameters,on the resonance responses.The numerical simulations show that the foundation excitation and the degree of coupling between the vibration modes exert a substantial effect on the chaotic dynamics of the system.Furthermore,the significant motions under particular excitation conditions are visualized by bifurcation diagrams,time histories,phase portraits,three-dimensional(3D)phase portraits,and Poincare maps.Finally,the vibration experiment is carried out to study the amplitude frequency responses and bifurcation characteristics for the bistable laminated composite shell,yielding results that are qualitatively consistent with the theoretical results.

关键词： bistable laminated composite shell dynamic snap-through mode Hopf bifurcation chaotic dynamics vibration experiment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Insight into effects of egg- and soybean-derived phosphatidylcholine on non-alcoholic steatosis in mice and HepG2 cells by lipidomics

引用

Food Science and Human Wellness 2024年

作者： Zhihui Yu Chunyou Liu Yating Gao Haoran Guo huiling duan Lixin Zhang Yisheng Chen College of Food Science and Engineering Shanxi Agricultural University Institute of Food Nutrition and Safety Shanxi Agricultural University Department of Food Science and Technology Guangxi University of Science and Technology

Dietary phosphatidylcholine (PC) is an ideal source of bioactive lipids showing efficacy to alleviate non-alcoholic fatty liver disease (NAFLD). In this study， the lipidomic profiles of nonalcoholic steatosis in mice and HepG2 cells treated with PC isolated from eggs (EPC) and soybean (SPC) were evaluated. EPC and SPC could significantly ameliorate fatty liver disease by down-regulating triglyceride (TG) and diglyceride (DG) levels. Remarkably， EPC exhibited better performance in regulating the hepatic lipid profile leading to decreased PC and TG， ceramides， phosphatidylethanolamine and phosphatidylserine levels. A total of 117 and 20 lipid biomarkers in liver and HepG2 cells involved in glycerophospholipid metabolism were screened out， respectively. The regulatory mechanism of EPC may be attributed to a decrease in the expression of ACACA and SREBP-1c. EPC， via suppressing lipogenic gene expression， which was superior to that of SPC in alleviating nonalcoholic steatosis. Overall， EPC and SPC attenuated HFD-induced NAFLD by improving the hepatic lipid profile. The more significant effect observed with EPC may be attributed to its modulation of glycerophospholipid metabolism.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Droplet impact on wetted structured surfaces

引用

Applied Mathematics and Mechanics(English Edition) 2022年第3期43卷 437-446页

作者： M.MOHASAN A.B.AQEEL huiling duan Pengyu LYU Yantao YANG Department of Mechanics and Engineering Science State Key Laboratory for Turbulence and Complex Systems(SKLTCS)Beijing Innovation Center for Engineering Science and Advanced Technology(BIC-ESAT)College of EngineeringPeking UniversityBeijing 100871China Department of Mechatronics Engineering National University of Sciences and TechnologyIslamabad 44000Pakistan Center for Applied Physics and Technology(CAPT) HEDPS and IFSA Collaborative Innovation Center of MoEPeking UniversityBeijing 100871China

In this study,we numerically investigate the droplet impact onto a thin liquid film deposited on a structured surface with square pillars and cavities.The time evolution of crown geometry is strongly affected by the surface structure.When the thickness of the liquid film is larger than the structure height,the expanding speed of the crown base radius is independent of the structure width.However,if the liquid film thickness is equal to the structure height,the crown base expands slower as the structure width increases.Surface structures have strong effects on the crown height and radius,and can prevent ejected filament from breaking into satellite droplets for certain cases.For the liquid film with the thickness equal to the pillar height,both the crown height and the radius exhibit non-monotonic behaviors as the pillar width increases.There exists one pillar width which produces the smallest crown height and the largest crown radius.

关键词： droplet impact structured surface liquid film crown formation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Critical velocity in phosphorus exchange processes across the sediment-water interface

引用

Journal of Environmental Sciences 2013年第10期25卷 1966-1971页

作者： Jun Wan Ze Wang Zhijie Li huiling duan HezhongYuan State Key Laboratory for Turbulence and Complex System Department of Mechanics and Aerospace EngineeringCollege of Engineering Peking University College of Mechanics and Materials Hohai University Research Center for Eco-Environmental Sciences Chinese Academy of Sciences School of Life Sciences Nanjing University

Sediments are ultimate sinks of nutrients in lakes that record the pollution history evolutionary processes, and anthropogenic activities of a lake. However, sediments are considered as inner sources of environmental factor changes such as the variation in hydrodynamic conditions because of the nutrients they release. How does this process happen？ This study investigates a typical nutrient phosphorus （P） exchange among sediment, suspended particle matter （SPM）, and water. Compared with numerical and experimental studies, this study confirms that the critical velocity that occurs at a lower flow rate state exists in the range of 7 to 15 crn/sec. Critical velocity below the critical flow rate promotes the migration of particulate phosphorus （PP） to the SPM. On the other hand, critical velocity above the critical flow rate promotes the release of PP in water.

关键词： abrupt expansion flow critical velocity lake eutrophication phosphorus exchange

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Solid–Liquid Composites with High Impact Resistance

引用

Acta Mechanica Solida Sinica 2021年第6期34卷 911-921页

作者： Miao Yu Xiying Li Pengyu Lv huiling duan Department of Mechanics and Engineering Science College of EngineeringPeking UniversityBeijing100871China CAPT HEDPS and IFSA Collaborative Innovation Center of MoEPeking UniversityBeijing100871China

Solid–liquid composites(SLCs)with novel thermal/electronic/mechanical properties imparted by programmable and functional liquid inclusions have attracted considerable research interest in recent years,and are widely used in smart electronics and soft robotics.The feasible application of SLCs requires that they exhibit excellent static physical properties as well as dynamic impact resistance to satisfy complex service conditions,such as drops and impacts.This paper examined the impact resistance of SLCs fabricated by using microfluidic 3D printing.The results of dynamic split-Hopkinson pressure bar(SHPB)tests showed that the performance of the fabricated SLCs improved in terms of energy dissipation and impact resistance compared with pristine materials.In case of dynamic impact in the strain rates ranging from 100 to 400s−1,the SLC specimen deformed without fracture,and its energy dissipation was dominated by the viscosity of the liquid inclusions.For dynamic impact in the strain rates ranging from 500 to 800s−1,the SLC specimen fractured and its energy dissipation was determined by the volume fraction of the liquid inclusions.Thus,the energy dissipation of the SLCs could be tuned by regulating the viscosity and volume fraction of the liquid inclusions to satisfy the requirements of protection against different strain rates.Furthermore,the process of fracture of the SLCs under the dynamic SHPB tests was recorded and analyzed by using a high-speed camera.The results showed that distributed liquid inclusions changed the paths of crack propagation to enhance energy dissipation in the SLCs.This study experimentally verified the enhancement in the energy dissipation of SLCs,and provided design strategies for developing multifunctional SLCs with high impact resistance.

关键词： Solid-liquid composites(SLCs) Impact resistance Dynamic SHPB Energy dissipation Fracturing process

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Theoretical models for irradiation hardening and embrittlement in nuclear structural materials:a review and perspective

引用

Acta Mechanica Sinica 2020年第2期36卷 397-411页

作者： Xiazi Xiao Dmitry Terentyev Haijian Chu huiling duan Department of Mechanics School of Civil EngineeringCentral South UniversityChangsha 410075China Structural Materials Group Institute of Nuclear Materials ScienceSCK-CEN2400 MolBelgium Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200444China State Key Laboratory for Turbulence and Complex System Department of Mechanics and Engineering Science College of EngineeringPeking UniversityBeijing 100871China CAPT HEDPS and IFSA CollaborativeInnovation Center of MoEBIC-ESATPeking UniversityBeijing 100871China

The study of irradiation hardening and embrittlement is critically important for the development of next-generation structural materials tolerant to neutron irradiation,and could dramatically affect the approach to the design of components for advanced nuclear reactors.In addition,a growing interest is observed in the field of research and development of irradiation-resistant materials.This review aims to provide an overview of the theoretical development related to irradiation hardening and embrittlement at moderate irradiation conditions achieved in recent years,which can help extend our fundamental knowledge on nuclear structural materials.After a general introduction to the irradiation effects on metallic materials,recent research progress covering theoretical modelling is summarized for different types of structural materials.The fundamental mechanisms are elucidated within a wide range of temporal and spatial scales.This review closes with the current understanding of irradiation hardening and embrittlement,and puts some perspectives deserving further study.

关键词： Irradiation hardening Irradiation embrittlement Theoretical models Fundamental mechanisms

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

改性玉米芯制备太阳能界面蒸发体及其性能分析

引用

农业工程学报 2024年第9期40卷 236-241页

作者：段慧玲凌童付小强阚阚河海大学电气与动力工程学院南京211100

针对天然生物质材料应用于海水淡化领域,蒸发效率较低、材料容易降解等问题,采用多巴胺对天然玉米芯进行改性处理,以改性玉米芯为基底,在其表面包覆炭黑-纤维素薄膜,制备了一种集光热转换、输水、隔热于一体的太阳能界面蒸发体。对改性... 详细信息

针对天然生物质材料应用于海水淡化领域,蒸发效率较低、材料容易降解等问题,采用多巴胺对天然玉米芯进行改性处理,以改性玉米芯为基底,在其表面包覆炭黑-纤维素薄膜,制备了一种集光热转换、输水、隔热于一体的太阳能界面蒸发体。对改性玉米芯蒸发体的光学吸收性能、输水性能、接触角进行表征,并搭建了室内蒸发试验和户外蒸发试验系统,测试了改性玉米芯的蒸发性能,与天然玉米芯相比,改性玉米芯蒸发体的蒸发速率相对未改性的提升了约10.4%。对改性玉米芯蒸发体进行了30次循环试验,蒸发体均保持稳定的蒸发速率,整个循环测试中蒸发速率波动不超过1%。并且,长期工作后,蒸发体表面没有盐分沉积,没有出现材料软化、降解现象。改性玉米芯蒸发体在海水环境中能够保持良好、稳定的蒸发性能,且能够有效降低海水中的Na^(+)、K^(+)、Mg^(2+)、Ca^(2+)等离子浓度,达到世界卫生组织所规定的饮用标准中的相应限值。改性玉米芯蒸发体的制备方法简单、成本低廉、蒸发性能稳定,为扩展生物质材料在海水淡化领域的应用提供了有效途径。

关键词：改性太阳能玉米芯界面蒸发体输水性能蒸发性能长期工作稳定

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

VIBRATION OF CANTILEVERS WITH ROUGH SURFACES

引用

Acta Mechanica Solida Sinica 2009年第6期22卷 550-554页

作者： huiling duan Yahui Xue Xin Yi State Key Laboratory for Turbulence and Complex System CAPT Department of Mechanics and Aerospace Engineering College of Engineering Peking University Beijing 100871 China Division of Engineering Brown University Providence RI 02912 USA

We study the effect of surface roughness on the resonance frequency of micro-cantilever sensors. The analysis demonstrates that surface roughness can enhance, decrease or even annul the effect of surface stress on the resonance frequency, depending on the surface inclination angle and the Poisson ratio of the coating film on the cantilever.

关键词： surface roughness surface stress resonance frequency micro-cantilevers

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of the actuation waveform on the drop size reduction in drop-on-demand inkjet printing

引用

Acta Mechanica Sinica 2020年第5期36卷 983-989,I0001页

作者： Anas Bin Aqeel Muhammad Mohasan Pengyu Lv Yantao Yang huiling duan SKLTCS and Department of Mechanics and Engineering Science BIC-ESATCollege of EngineeringPeking UniversityBeijing 100871China Department of Mechatronics Engineering National University of Sciences and TechnologyIslamabadPakistan Key Laboratory of High Energy Density Physics Inertial Fusion Sciences and Application Collaborative Innovation Center of Ministry of EducationPeking UniversityBeijing 100871China

In this study the effects of the actuation waveforms on the droplet generation in a drop-on-demand inkjet printing are studied systematically by numerical simulations.Two different types of waveforms,namely the unipolar and bipolar actuations,are investigated for three fluids with different physical properties.We focus on two key parameters,which are the dwell time and the velocity amplitude.For the unipolar driving,the ejection velocity and the ejected liquid volume are both increased as the velocity amplitude becomes larger.The dwell time only has minor effects on both the ejection velocity and the ejected liquid volume.The ejection velocity decreases significantly for large liquid viscosity,while the influences of viscosity on the ejected liquid volume are much weaker.Four different droplet morphologies and the corresponding parameter ranges are identified.The droplet radius can be successfully reduced to about 40%e of the nozzle exit radius.For the bipolar waveforms,same droplet morphologies are observed but with shifted boundaries in the phase space.The minimal radius of stable droplet produced by the bipolar waveforms is even smaller compared to the unipolar ones.

关键词： Drop-on-demand inkjet printing Actuation waveform optimization Droplet ejection-Printability range

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Mechanical properties of irradiated multi-phase polycrystalline BCC materials

引用

Acta Mechanica Sinica 2015年第2期31卷 191-204页

作者： Dingkun Song Xiazi Xiao Jianming Xue Haijian Chu huiling duan State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering ScienceCollege of EngineeringPeking University CAPT HEDPS and IFSA Collaborative Innovation Center of MoEPeking University Department of Mechanics College of SciencesShanghai University Shanghai Institute of Applied Mathematics and Mechanics

Structure materials under severe irradiations in nuclear environments are known to degrade because of irradiation hardening and loss of ductility,resulting from irradiation-induced defects such as vacancies,interstitials and dislocation loops,etc.In this paper,we develop an elastic-viscoplastic model for irradiated multi-phase polycrystalline BCC materials in which the mechanical behaviors of individual grains and polycrystalline aggregates are both explored.At the microscopic grain scale,we use the internal variable model and propose a new tensorial damage descriptor to represent the geometry character of the defect loop,which facilitates the analysis of the defect loop evolutions and dislocation-defect interactions.At the macroscopic polycrystal scale,the self-consistent scheme is extended to consider the multiphase problem and used to bridge the individual grain behavior to polycrystal properties.Based on the proposed model,we found that the work-hardening coefficient decreases with the increase of irradiation-induced defect loops,and the orientation/loading dependence of mechanical properties is mainly attributed to the different Schmid factors.At the polycrystalline scale,numerical results for pure Fe match well with the irradiation experiment data.The model is further extended to predict the hardening effect of dispersoids in oxide-dispersed strengthened steels by the considering the Orowan bowing.The influences of grain size and irradiation are found to compete to dominate the strengthening behaviors of materials.

关键词： Irradiation Self-consistent method Multi-phase polycrystal Dislocation density

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：