检索结果-南通市图书馆

Programmable soft bending actuators with auxetic metamaterials

Science China(Technological Sciences) 2020年第12期63卷 2518-2526页

作者： PAN Qi chen ShiTong chen feifei ZHU XiangYang Robotics Institute School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

Soft robotics has been receiving increasing attention due to its flexibility and adaptability offered by embodied intelligence. A soft robot may undergo complex motions including stretching,contraction,bending,twisting,and their intricate *** these basic motions,bending plays a central role when a robot accomplishes tasks such as locomotion,grasping and manipulation. Although a rich repertoire of bending mechanisms has been reported,a systematic and rational design framework is still lack. In this paper,we provide a novel design strategy for soft bending actuators which allows integral modeling and design optimization. Nowadays,metamaterials are emerging as a new tool for soft robots,by encoding the desired complex motions directly within the material architectures,leading to conformable monolithic systems. We combine pneumatic actuators and flexible metamaterials to provide an alternative solution to soft bending actuators,with advantages of compact design,large bending motion,and convenient fabrication. A regular pneumatic chamber is embedded inside auxetic and non-auxetic metamaterials,and bending is generated when inflated. We carry out dimensionless analysis to identify the key design variables. To provide insight into design optimization,we develop a computation framework by modeling metamaterial structures with beam elements and the inner chamber with shell elements as an integral part,allowing efficient simulation of the coupled system. We systematically investigate how the bending angle varies with the key design variables and find the optimal design *** experimental results are well in line with the simulation,and a remarkable bending motion of 0.43°/mm is achieved.

关键词： soft robotics bending actuator auxetic metamterials negative Poisson’s ratio

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

Optimal biaxial prestretch ratios of soft dielectric elastomer actuators for maximal voltage-induced displacement

引用

Science China(Technological Sciences) 2023年第10期66卷 2871-2881页

作者： LUO Kai WU JiaNing chen feifei School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China Meta Robotics Institute Shanghai Jiao Tong UniversityShanghai 200240China

Prestretch plays an indispensable role in programming the voltage-induced deformation of dielectric elastomer actuators(DEAs).However,lacking rational design methods,the level of prestretch is usually determined through time-consuming experiments and trial-and-error *** this paper,we aim to quantitatively determine the optimal biaxial prestretch ratios for maximizing the voltage-induced displacement of *** on the Lagrange method and adjoint sensitivity analysis,we obtain the derivative of the displacement field with respect to the principal prestretch ratios,in which the nonlinearities and complex electromechanical coupling of DEAs are rigorously taken into *** derivative information allows for performing gradient-based optimization at a high convergence *** propose a comprehensive optimization framework connecting the nonlinear finite element analysis and sensitivity analysis to iteratively identify the optimal prestretch *** validate our method on two classical types of DEAs,i.e.,planar DEAs with fixed boundaries and free-standing three-dimensional dielectric elastomer minimum energy structures(DEMES).The simulation and experiment results both show that remarkable improvements in concerned displacements are obtained compared with the non-optimized designs.

关键词： dielectric elastomer prestretch ratios design optimization

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

Temperature dependent behaviors of electro-elastic properties of NdCa_(4)O(BO_(3))_(3)crystal with monoclinic symmetry

引用

Journal of Rare Earths 2022年第11期40卷 1772-1777,I0004页

作者： Guiteng Yao feifei chen Fapeng Yu Xian Zhao State Key Laboratory of Crystal Materials Center for Optics Research EngineeringShandong UniversityJinan 250100China

Rare-earth calcium oxyborate crystals(RECa_(4)O(BO_(3))_(3),RECOB,RE:rare-earth elements)are a kind of multifunctional crystal *** this work,the temperature dependent behaviors of the electroelastic constants of NdCOB crystal were investigated over the temperature range of-80-200℃,and their temperature coefficients were *** is found that NdCOB crystal possesses minimal variation of relative dielectric permittivities(<3%).The temperature coefficient of frequency for ZY cut with width shear vibration mode is in the order of 0.07×10^(-4)/℃.The temperature coefficients of the elastic compliances are obtained to be in the range of-33.0×10^(-4)/℃-32.2×10^(-4)/℃.Particularly,the sand swere found to show low temperature coefficients of the elastic compliances,i.e.1.0×10^(-4)/℃and-0.4×10^(-4)/℃,respectively,indicating the existence of zero temperature coefficient of frequency crystal ***,the electromechanical coupling factors and piezoelectric coefficients as a function of temperature were *** electromechanical coupling factor kand piezoelectric coefficient dare determined to be~30.8%and~15.2 pC/N at room temperature,*** large piezoelectric response and zero temperature coefficient of frequency indicate the potential usage of NdCOB crystal for piezoelectric frequency devices over a wide temperature range.

关键词： NdCOB Electro-elastic constants Temperature dependence Zero temperature coefficient of frequency Rare earths

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

Enhancing interaction performance of soft pneumatic-networks grippers by skeleton topology optimization

引用

Science China(Technological Sciences) 2021年第12期64卷 2709-2717页

作者： chen ShiTong WANG YuSheng LI Dechen chen feifei ZHU XiangYang Robotics Institute School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

The inherent compliance of soft materials imbues robots,generally referred to as soft robots,with particular advantages in producing adaptive and safe ***,the mainstream design paradigms of soft robots have been focused on pursuing large free motions only,usually at the expense of greatly decreased stiffness,leading to limited capability of withstanding external loads in interactive *** is a pressing need to incorporate the interaction specifications at the design stage to embody soft robots with not only proper deformability but equally importantly,considerable stiffness to perform complex tasks in practical ***,inspired by the dexterity of human hands,we propose a computational design framework for soft grippers with a focus on improving their interaction performance in power grasping or precision grasping *** design paradigm rests on attaching a relatively stiffer skeleton layer to the parametric pneumatic networks based actuator which is widely used due to the geometric advantage,and the skeleton layout is designed for customized interaction conditions by a level set based topology optimization *** expected,the optimized skeleton layouts exhibit specified structural features highly relevant to the predefined concentrated loads for precision grip or distributed loads for power grip,which physically implies the compromise between deformability and *** the interaction forces are difficult to measure in situ,we devise power and precision grasping scenarios and evaluate the critical actuation pressure of the object’s falling *** experiments qualitatively demonstrate the superiority of each specified *** work represents an initial step toward the rational design for interaction in soft robots.

关键词： soft robotics interaction grippers topology optimization

来源：

维普期刊数据库

同方期刊数据库

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

E^2KF Based Joint Multiple CFOs and Channel Estimate for MIMO-OFDM Systems over High Mobility Scenarios

引用

China Communications 2014年第A01期11卷 56-63页

作者： QIAO Jing chen Qingchun SHEN feifei KeyLabofInformationCoding&Transmission SouthwestJiaotongUniversityChengduSichuan610031China

An enhanced extended Kalman filtering （E2KF） algorithm is proposed in this paper to cope with the joint multiple carrier frequency offsets （CFOs） and time-variant channel estimate for MIMO-OFDM systems over high mobility scenarios. It is unveiled that, the auto-regressive （AR） model not only provides an effective method to capture the dynamics of the channel parameters, which enables the prediction capability in the EKF algorithm, but also suggests an method to incorporate multiple successive pilot symbols for the improved measurement update.

关键词： CFO channel estimate MIMO-OFDM

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

Modeling of 3-D Air Traffic Complexity Based on Route Structure Constraints

引用

Transactions of Nanjing University of Aeronautics and Astronautics 2019年第2期36卷 352-360页

作者： XIE Hua WU Zhe chen feifei chen Haiyan College of Civil Aviation Nanjing University of Aeronautics and AstronauticsNanjing 211106P.R.China State Key Laboratory of Air Traffic Management System and Technology Nanjing 210007P.R.China College of Computer Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106P.R.China

It is an important issue to assess traffic situation complexity for air traffic *** is a lack of systematic review of the existing air traffic complexity assessment methods,and there is no consideration of the role of airspace and traffic coordination mechanism.A new 3-D airspace complexity measurement method is proposed based on route structure constraints to evaluate the air traffic complexity ***,the model of the impact on horizontal and vertical direction for“aircraft pair”is established based on the route *** that,the coupled complexity model for 3-D airspace is given according to the modification on the model in terms of flight ***,the global model of the airspace traffic complexity is *** is proved by the experimental data from the actual operation in airspace that the proposed model can reflect the space coupling situation and complexity of *** the same time,it can precisely describe the actual operation of civil aviation in China.

关键词： air traffic management traffic complexity flight standardization aircraft pair 3-D airspace

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

Tailoring the in-plane and out-of-plane stiffness of soft fingers by endoskeleton topology optimization for stable grasping

引用

Science China(Technological Sciences) 2023年第11期66卷 3080-3089页

作者： LI Dechen chen ShiTong SONG ZeNan LIANG JiaLong ZHU XiangYang chen feifei State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Meta Robotics Institute Shanghai Jiao Tong UniversityShanghai 200240China

The intrinsic compliance of soft materials endows soft robots with great advantages to achieve large deformation and adaptive interactions in grasping ***,current soft grippers usually focus on the in-plane large deformation and load capacity but ignore the effect of out-of-plane external loads,which may lead to instability in practical *** problem calls for stiffness design along multiple directions to withstand not only in-plane interacting forces with objects,but also unexpected outof-plane *** this paper,we design a new type of soft finger by embedding an endoskeleton inside the widely-used PneuNets actuator,and the endoskeleton layout is optimized to achieve a remarkable bending deflection and limited lateral deflection under combined external in-plane and out-of-plane *** on the multi-objective topology optimization approach,the key structural features of the optimized endoskeleton are extracted and *** multi-material soft fingers are fabricated by the silicone compound mold *** and dynamic experiment results validate that the soft gripper with endoskeleton embedded exhibits remarkably improved out-of-plane stiffness,without sacrificing the in-plane bending flexibility,and leads to more stable grasping.

关键词： soft robot soft gripper stable grasping topology optimization pneumatic actuator

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

蠲痹汤含药血清调控线粒体自噬抑制白细胞介素1β诱导的关节软骨细胞损伤

引用

中国组织工程研究 2025年第14期29卷 2882-2891页

作者：郑永智陈飞飞康乾晋春阳王若秦河南省中医院关节病科河南省郑州市450000 河南省胸科医院结核内科河南省郑州市450000

背景:软骨细胞线粒体自噬的缺陷会引起细胞凋亡和基质消失等软骨细胞退行性病变的变化。目的:探讨蠲痹汤含药血清对白细胞介素1β诱导的大鼠膝关节软骨细胞炎症反应和凋亡的影响及可能作用机制。方法:50只雄性SD大鼠随机给予生理盐水、... 详细信息

背景:软骨细胞线粒体自噬的缺陷会引起细胞凋亡和基质消失等软骨细胞退行性病变的变化。目的:探讨蠲痹汤含药血清对白细胞介素1β诱导的大鼠膝关节软骨细胞炎症反应和凋亡的影响及可能作用机制。方法:50只雄性SD大鼠随机给予生理盐水、蠲痹汤低、中、高剂量(1.24,2.48,4.96 g/kg)、塞来昔布(阳性药物),连续灌胃2周后获得含药血清。①分离软骨细胞,将其随机分为对照组、白细胞介素1β组、蠲痹汤低、中、高剂量含药血清组及阳性药物血清组。CCK-8法检测细胞存活率、免疫荧光双染检测线粒体自噬水平、免疫荧光检测磷酸化腺苷酸激活蛋白激酶水平、Western blot检测PTEN诱导激酶1/Parkin通路相关蛋白和裂解的半胱氨酸蛋白酶蛋白3表达、ELISA检测炎症因子水平;②分别采用PTEN诱导激酶1 siRNA和Compound C进行干预,探究AMPK/PTEN诱导激酶1/Parkin通路在蠲痹汤含药血清调控线粒体自噬中的作用。结果与结论:①与对照组比较,白细胞介素1β组软骨细胞存活率、Ⅱ型胶原蛋白表达、磷酸化腺苷酸激活蛋白激酶、PTEN诱导激酶1、Parkin和微管相关蛋白1轻链3蛋白水平以及线粒体自噬水平明显降低(P<0.05),而裂解的半胱氨酸蛋白酶蛋白3蛋白水平、白细胞介素6、白细胞介素8和肿瘤坏死因子α水平显著升高(P<0.05);与白细胞介素1β组比较,蠲痹汤各剂量含药血清组和阳性药物血清组上述各项指标呈现相反的变化(P<0.05);②PTEN诱导激酶1 siRNA可显著抑制蠲痹汤含药血清对白细胞介素1β处理软骨细胞线粒体自噬的影响,降低蠲痹汤含药血清对白细胞介素1β诱导的软骨细胞炎症与凋亡的保护作用;Compound C逆转了蠲痹汤含药血清对白细胞介素1β处理软骨细胞中PTEN诱导激酶1/Parkin信号通路的影响。结论:蠲痹汤含药血清通过影响线粒体自噬水平来抑制软骨细胞炎症和凋亡,从而减轻白细胞介素1β诱导的软骨细胞退化,其机制可能与调控AMPK/PTEN诱导激酶1/Parkin通路有关。

关键词：蠲痹汤软骨细胞线粒体自噬腺苷酸激活蛋白激酶 AMPK PTEN诱导激酶1/Parkin

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

Circular RNA ubiquitin-associated protein 2 enhances autophagy and promotes colorectal cancer progression and metastasis via miR-582-5p/FOXO1 signaling

引用

Journal of Genetics and Genomics 2021年第12期48卷 1091-1103页

作者： feifei chen Lei Guo Jiehui Di Man Li Dong Dong Dongsheng Pei Department of Cell Biology Xuzhou Medical UniversityXuzhouJiangsu 221002China Cancer Institute Xuzhou Medical UniversityXuzhouJiangsu 221002China

Numerous circular RNAs(circ RNAs) have been identified as vital regulators in various cancers. The newly reported circular RNA ubiquitin-associated protein 2(circ UBAP2) is a critical player in cell growth and metastasis in various types of cancers, although its role in colorectal cancer(CRC) has yet to be fully elucidated. We find that circ UBAP2 is upregulated in CRC tissues and cell lines to induce autophagy both in vitro and in vivo. The effects of circ UBAP2 on migration, invasion, and proliferation may be partially related to autophagy. Mechanistically, we uncover that circ UBAP2 can directly interact with mi R-582-5 p and subsequently act as a micro RNA sponge to regulate the expression of the mi R-582-5 p target gene forkhead box protein O1(FOXO1) and downstream signaling molecules, which collectively advance the progression and metastasis of CRC. These results suggest that circ UBAP2 acts as an oncogene via a novel circ UBAP2/mi R-582-5 p/FOXO1 axis, providing a potential biomarker and therapeutic target for CRC management.

关键词： CircUBAP2 MiR-582-5p FOXO1 Autophagy Colon cancer

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

Dynamic 3D shape reconstruction under complex reflection and transmission conditions using multi-scale parallel single-pixel imaging

引用

Light(Advanced Manufacturing) 2024年第3期5卷 93-104页

作者： Zhoujie Wu Haoran Wang feifei chen Xunren Li Zhengdong chen Qican Zhang School of Electronics and Information Engineering Sichuan UniversityChengduSichuan Province 610065China

Depth measurement and three-dimensional(3D)imaging under complex reflection and transmission conditions are challenging and even impossible for traditional structured light techniques,owing to the precondition of point-to-point *** recent progress in addressing this problem,there is still no efficient and general ***,a Fourier dual-slice projection with depth-constrained localization is presented to separate and utilize different illumination and reflection components efficiently,which can significantly decrease the number of projection patterns in each sequence from thousands to ***,multi-scale parallel single-pixel imaging(MS-PSI)is proposed based on the established and proven position-invariant theorem,which breaks the local regional assumption and enables dynamic 3D *** methodology successfully unveils unseen-before capabilities such as(1)accurate depth measurement under interreflection and subsurface scattering conditions,(2)dynamic measurement of the time-varying high-dynamic-range scene and through thin volumetric scattering media at a rate of 333 frames per second;(3)two-layer 3D imaging of the semitransparent surface and the object hidden behind *** experimental results confirm that the proposed method paves the way for dynamic 3D reconstruction under complex optical field reflection and transmission conditions,benefiting imaging and sensing applications in advanced manufacturing,autonomous driving,and biomedical imaging.

关键词： Computational imaging 3D shape reconstruction 3D imaging Single-pixel imaging Light transport coefficient

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

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：