检索结果-南通市图书馆

Anthropomorphic hand based on twisted-string-driven da Vinci’s mechanism for approaching human dexterity and power of grasp

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

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2022年第10期23卷 771-782页

作者： Yong-bin JIN shao-wen cheng Yan-yan YUAN Hong-tao WANG Wei YANG Center for X-Mechanics Zhejiang UniversityHangzhou 310027China ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang UniversityHangzhou 311200China State Key Laboratory of Fluid Power and Mechatronic System Zhejiang UniversityHangzhou 310027China Institute of Applied Mechanics Zhejiang UniversityHangzhou 310027China

Designing anthropomorphic prosthetic hands that approach human-level performance remains a great *** prosthetics are still inferior to human hands in several important properties, such as weight, size, fingertip force,grasp velocity, and active and passive dexterities. We present a novel design based on the under-actuated da Vinci’s mechanism driven by a flexible twisted string actuator(TSA). The distributed drive scheme allows structural optimization using a motion capture database to reproduce the natural movement of human hands while keeping adaptability to free-form objects. The application of TSA realizes a high conversion from motor torque to tendon contraction force while keeping the structure light,flexible, and compact. Our anthropomorphic prosthetic hand, consisting of six active and 15 passive degrees of freedom, has a weight of 280 g, approximately 70% of that of a human hand. It passed 30 of the 33 Feix grasp tests on objects in daily living and retained a loading capacity of 5 kg. This simple but intelligent mechanism leads to excellent stability and adaptability and renders feasible wide applications in prosthetics and in service robots.

关键词： Anthropomorphic hand da Vinci’s mechanism Twisted string actuator(TSA) Intelligent mechanism Principal component analysis(PCA)

The Crystallization Behavior of L-Poly(lactic acid)/Polypropylene Blends:The Acceleration for Both L-Poly(lactic acid)and Polypropylene

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第6期42卷 775-786页

作者： Shuang-cheng Li Wei-Jia Zhou wen-Jie Wu Jun shao Shui-Liang Chen Hao-Qing Hou Sheng Xiang College of Chemistry&Chemical Engineering and Nanofiber Engineering Center of Jiangxi Province Jiangxi Normal UniversityNanchang330022China National Engineering Research Center for Carbohydrate Synthesis/Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education Jiangxi Normal UniversityNanchang330022China wenzhou Institute University of Chinese Academy of SciencesWenzhou325001China

For a polymer/polymer dismissible blend with two crystallizable components,the crystallization behavior of different components and the reciprocal influences between different crystals are interesting and important,but did not investigate in *** this study,the L-poly(lactic acid)/polypropylene(PLLA/PP)blends with different weight ratios were prepared by melt mixing and the crystallization behavior of the blends were *** showed that the crystalline structures of PLLA and PP were not altered by the *** the crystallization of PLLA,both the diffusion of chain segments and crystallization rate were enhanced under the existence of PP *** the crystallization of PP,its crystallization rate was depressed under the existence of amorphous PLLA molecular *** the PP crystallized from the existence of PLLA crystals,although the diffusion rate of PP was reduced by PLLA crystals,the nucleation positions were obviously enhanced,which accelerated the formation of PP *** investigation would supply more basic data for the application of PLLA/PP blend.

关键词： L-poly(lactic acid) Polypropylene Blends Crystalization behavior Crystallization acceleration

Macroscopic model and statistical model to characterize electromagnetic information of a digital coding metasurface

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第03期11卷 159-171页

作者： Rui wen shao Jun Wei Wu Zheng Xing Wang Hui Xu Han Qing Yang Qiang cheng Tie Jun Cui Institute of Electromagnetic Space Southeast University State Key Laboratory of Millimeter Waves Southeast University Peng cheng Laboratory Pazhou Laboratory(Huangpu)

A digital coding metasurface is a platform connecting the digital space and electromagnetic wave space, and has therefore gained much attention due to its intriguing value in reshaping wireless channels and realizing new communication architectures. Correspondingly, there is an urgent need for electromagnetic information theory that reveals the upper limit of communication capacity and supports the accurate design of metasurface-based communication systems. To this end, we propose a macroscopic model and a statistical model of the digital coding metasurface. The macroscopic model uniformly accommodates both digital and electromagnetic aspects of the meta-atoms and predicts all possible scattered fields of the digital coding metasurface based on a small number of simulations or measurements. Full-wave simulations and experimental results show that the macroscopic model is feasible and accurate. A statistical model is further proposed to correlate the mutual coupling between meta-atoms with covariance and to calculate the entropy of the equivalent currents of digital coding metasurface. These two models can help reconfigurable intelligent surfaces achieve more accurate beamforming and channel estimation, and thus improve signal power and coverage. Moreover, the models will encourage the creation of a precoding codebook in metasurface-based direct digital modulation systems, with the aim of approaching the upper limit of channel capacity. With these two models, the concepts of current space and current entropy, as well as the analysis of information loss from the coding space to wave space, is established for the first time, helping to bridge the gap between the digital world and the physical world, and advancing developments of electromagnetic information theory and new-architecture wireless systems.

关键词： electromagnetic information theory current entropy current space digital coding metasurface macroscopic model statistical model

The clinical relevance of MBL2 gene polymorphism and sepsis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2018年第3期11卷 251-254页

作者： shao-wen cheng Li-Na Xian Zhi-Xing Lin Xue Ao Jun-Yi Yao Ying-Qing Li Yong-Yan Li Xiu-Ru Li Wei-cheng Wang Chuan-Zhu Lyu Ying Li Nanjing Medical University NanjingJiangsuChina Trauma Center The First Affiliated Hospital of Hainan Medical UniversityHaikou HainanChina Intensive Care Unit The First Affiliated Hospital of Hainan Medical UniversityHaikou HainanChina Intensive Care Unit Haikou Hospital Affiliated to Xiangya School of MedicineCentral South UniversityHaikou HainanChina hainan medical university Haikou 571199HainanChina

Objective:To detect the clinical relevance of mannose-binding lectin 2(MBL2) gene polymorphism and sepsis in Chinese lived in Hainan ***: Blood samples from 57 patients with sepsis and 69 patients without sepsis were collected in the ICU of several large hospitals in Hainan province. Genomic DNA was extracted from whole blood and then PCR purification product was sequenced and typed by 3730 sequencing analyzer. The concentration of MBIL2 in serum was detected by ***: We found that genotype and allele distributions in two groups were in accordance with the Hardy-Weinberg Equilibrium. The frequency of GA genotype was significantly higher than that in non-sepsis group(P=0.013). A allele frequency in sepsis group was also much higher than that in non-sepsis group(P=0.028).Logister regression analysis showed that the patients who carried A allele were more prone to get sepsis than G allele carrier(P=0.014, OR=2,550, 95%CI=1.207-5.386). The MBL2 level in serum of sepsis patients with genotype GG and GA was significantly lower than that in non-sepsis group(P<0.05). In sepsis group, the MBL2 serum level of patients with genotype GA was obviously lower than that in patients with genotype GG(P<0.05).Conclusions: The variation of rs 1800450 G→A increased the incidence of sepsis and decreased the level of MBL2 in serum.

关键词： Mannose-binding lectin 2 Polymorphism Sepsis

Flow characteristics and bubble statistics during the fragmentation process of the ingested main cavity in plunging breaking waves

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

Journal of Hydrodynamics 2024年第3期36卷 546-555页

作者： wen-bin Zhang Wei-wen Zhao De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China

Plunging breaking waves play an important role in the exchange of heat,momentum,and mass between the atmosphere and *** this paper,a series of direct numerical simulations is conducted to investigate the fragmentation process of the ingested main cavity in plunging breaking *** two-phase Navier-Stokes equations are solved using the finite-volume method based on adaptive refinement *** free surface is captured using a geometrical volume of fluid *** 2-D,3-D simulations are *** flow fields at different stages of wave breaking are presented and quantitative analysis for bubbles is *** 2-D instantaneous vorticity field and local velocity field are visualized to discuss the general flow characteristics during the fragmentation *** a 2-D parametric study is conducted to investigate the differences in the flow characteristics during the fragmentation process under different wave parameters including initial wave steepness(ε),Bond number(Bo),and Reynolds number(Re).3-D vortex structures are shown to further investigate the mechanisms behind the differences in the flow *** bubble size distributions under two different initial wave steepness are also discussed with their relationship to the fragmentation process of the ingested main *** research offers a significant understanding of the distinct procedures and fundamental dynamics involved in wave breaking,enhancing our comprehension of this intricate event.

关键词： Plunging breaking waves multiphase flow bubble statistics

Spin asymmetry and dipole moments inτ-pair production with ultraperipheral heavy ion collisions

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

Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 15-21页

作者： Dingyu shao Bin Yan Shu-Run Yuan cheng Zhang Department of Physics Center for Field Theory and Particle PhysicsFudan UniversityShanghai 200433China Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Fudan UniversityShanghai 200433China Shanghai Research Center for Theoretical Nuclear Physics National Natural Science Foundation of China(NSFC)and Fudan UniversityShanghai 200438China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China School of Physics Peking UniversityBeijing 100871China

The anomalous magnetic(MDM)and electric(EDM)dipole moments of theτlepton serve as crucial indicators of new physics beyond the standard *** azimuthal angular asymmetry as a novel tool in ultraperipheral collisions(UPCs),we attain unparalleled precision in the study of these key *** by the highly linear polarization of coherent photons,this method uniquely enables both the MDM and EDM to contribute to the cos 2φangular distribution in similar ***,our approach substantially narrows the parameter space,excluding more than half of it compared to expected UPC-based measurements reliant solely on the total *** method not only provides improved constraints but also minimizes the need for additional theoretical assumptions,and offers a novel avenue to probe the EDM effects.

关键词： ultraperipheral collisions magnetic and electric dipole moments spin asymmetry

同方期刊数据库

Propagation Properties of Shock Waves in Polyurethane Foam based on Atomistic Simulations

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第1期31卷 117-129页

作者： Zhiqiang Hu Jianli shao Shiyu Jia Weidong Song cheng Wang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

Porous materials are widely used in the field of protection because of their excellent energy absorption *** this work,a series of polyurethane microscopic models are established and the effect of porosity on the shock waves is studied with classical molecular dynamics ***,shock Hugoniot relations for different porosities are obtained,which compare well with the experimental *** pores collapse and form local stress wave,which results in the complex multi-wave structure of the shock *** microstructure analysis shows that the local stress increases and the local velocity decreases gradually during the process of pore collapse to complete ***,it leads to stress relaxation and velocity *** shock stress peaks can be fitted with two exponential functions,and the amplitude of attenuation coefficient decreases with the increase of ***,the pore collapse under shock or non-shock are discussed by the entropy increase rate of the *** energy is dissipated mainly through the multiple interactions of the waves under *** energy is dissipated mainly by the friction between atoms under non-shock.

关键词： Polyurethane foam Shock wave Attenuation Atomistic simulation

On the global smooth solutions of 3D incompressible Hall-MHD equations

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 319-327页

作者： YUE Gao-cheng SUN wen-da School of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 211106China

The present paper is devoted to the well-posedness issue for the 3D incompressible Hall-MHD system obtained from kinetic models. Our analysis strongly relies on the use of the Fourier analysis. We establish the global existence of smooth solutions for a class of large initial data, this result implies the initial velocity and magnetic field can be arbitrarily large.

关键词： 3D Hall-MHD well-posedness Fourier analysis

Differential Operator Approach to■quantum Groups and Their Oscillator Representations

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第5期40卷 1360-1374页

作者： Zhao Bing FAN Ji cheng GENG shao Long HAN College of Mathematical Science Harbin Engineering UniversityHarbin 150001P.R.China

For a quasi-split Satake diagram,we define a modified q-Weyl algebra,and show that there is an algebra homomorphism between it and the corresponding■quantum *** other words,we provide a differential operator approach to■quantum ***,the oscillator representations of■quantum groups are *** crystal basis of the irreducible subrepresentations of these oscillator representations are constructed.

关键词： ■quantum group differential operator oscillator representation crystal basis