检索结果-南通市图书馆

State of the art in movement around a remote point:a review of remote center of motion in robotics

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mechanical Engineering 2024年第2期19卷 1-28页

作者： Wuxiang ZHANG Zhi WANG Ke ma Fei LIU Pengzhi CHENG Xilun DING School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Ningbo Institute of Technology Beihang UniversityNingbo 315832China Intelligent Aerospace manufacturing Engineering Technology Co. Ltd.Beijing 100191China

The concept of remote center of motion(RCM)is pivotal in a myriad of robotic applications,encompa-ssing areas such as medical robotics,orientation devices,and exoskeletal *** efficacy of RCM technology is a determining factor in the success of these robotic *** paper offers an exhaustive review of RCM technologies,elaborating on their various methodologies and practical *** delves into the unique characteristics of RCM across different degrees of freedom(DOFs),aiming to distill their fundamental *** addition,this paper categorizes RCM approaches into two primary classifications:design based and control *** are further organized according to their respective DOFs,providing a concise summary of their core *** upon the understanding of RCM’s versatile capabilities,this paper then transitions to an in-depth exploration of its applications across diverse robotic *** this review,we critically analyze the existing research challenges and issues that are inherently present in both RCM methodologies and their *** discussion is intended to serve as a guiding framework for future research endeavors and practical deployments in related areas.

关键词： remote center of motion mechanism robotics medical robot orientation device exoskeleton

Uniform decomposition of velocity gradient tensor

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1期36卷 24-34页

作者： Chenxi ma Chaoqun Liu Department of mathematics University of Texas at ArlingtonArlingtonTXUSA

In this paper,the principal decomposition of the velocity gradient tensor[∇v]is discussed in 3 cases based on the discriminant∆:∆0 with 3 distinct real eigen values,and∆=0 with 1 or 2.distinct real eigen *** velocity gradient tensor can also be classified as rotation point,which can be decomposed into three parts,i.e.,rotation[R],shear[S]and stretching/compression[SC],and non-rotation point,we defined a new resistance term[L],and the tensor can be decomposed into three parts,i.e.,resistance[L],shear[S]and stretching/compression[SC].Example matric are also displayed to demonstrate the new *** of principal decomposition between 3 different cases,and between Resistance and Liutex will also be discussed.

关键词： Velocity gradient Liutex resistance fluid kinematics

VOC emitted by biopharmaceutical industries:Source profiles,health risks,and secondary pollution

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 Environmental Sciences 2024年第1期135卷 570-584页

作者： Jiawei ma Lin Li State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China univ.rsity of Chinese Academy of Sciences Beijing 100049China National Engineering Laboratory for VOCs Pollution Control material&Technology University of Chinese Academy of SciencesBeijing 101408China

The biopharmaceutical industry contributes substantially to volatile organic compounds(VOCs)emissions,causing growing concerns and social developmental *** study conducted an on-site investigation of the process-based emission of VOCs from three biopharmaceutical *** the workshops of the three enterprises,2. VOCs were detected,which could be sorted into 4 classes:hydrocarbons,aromatic hydrocarbons,oxygen-containing compounds,and nitrogen-containing *** were the main components of waste gases,accounting for 44.13%-77.85%of the overall ***-based source profiles were compiled for each process unit,with the fermentation and extraction units of tiamulin fumarate being the main source of VOC *** heptanone,vinyl acetate,diethylamine,propylene glycol methyl ether(PGME),and benzene were screened as priority pollutants through a fuzzy comprehensive evaluation *** level concentration simulation results of the Gauss plume diffusion model demonstrated that the diffusivity of VOCs in the atmosphere was relatively high,indicating potential non-carcinogenic and carcinogenic risks 1.5-2.km ***,the process-based formation potentials of ozone and secondary organic aerosols(SOAs)were determined and indicated that N-methyl-2.pyrrolidone,dimethyl heptanone,and PGME should be preferentially controlled to reduce the ozone formation potential,whereas the control of benzene and chlorobenzene should be prioritized to reduce the generation of *** results provide a basis for understanding the characteristics of VOC emission by biopharmaceutical industries and their diffusion,potentially allowing the development of measures to reduce health risks and secondary pollution.

关键词： Biopharmaceutical Volatile organic compound Priority pollutant Exposure risk Secondary pollution

Stimuli-evoked NOergic molecules and neuropeptides at acupuncture points and the gracile nucleus contribute to signal transduction of propagated sensation along the meridian through the dorsal medulla-thalamic pathways

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Medicine 2024年第5期22卷 515-522页

作者： Sheng-xing ma Lundquist Institute for Biomedical Innovation Harbor-University of California at Los Angeles(UCLA)Medical CenterTorranceCA 90502USA Department of Obstetrics and Gynecology David Geffen School of Medicine at UCLA and Harbor-UCLA Medical CenterTorranceCA 90502USA

Numerous studies from different international groups have demonstrated that sensations can be propagated along acupuncture channel *** propagated sensation along the channel pathway(PSCP)can be elicited by electroacupuncture(EA),transcutaneous electrical nerve stimulation(TENS),manual acupuncture(ma),and heat applied to distal acupuncture points(acupoints).Nitric oxide(NO)levels were reported to be elevated in the gracile nucleus and skin regions near to the EA sites,with higher levels at acupoints associated with an enhanced expression of NO synthase and transient receptor potential vanilloid type *** stimuli,EA,ma,TENS,and heat,have been used to elicit axonal reflexes,which increase local release of NO and neuropeptides such as calcitonin gene related ***,the sensation of PSCP along the body surface occurs only ipsilaterally to the stimulated acupoints in various human studies,which does not support the involvement of the spinal-thalamic pathway,which would involve cross over transmission of the *** gracile nucleus receives ascending input from the sciatic nerve and responds to somatosensory stimulation mainly on the ipsilateral side via the dorsal column *** at Zusanli(ST36)increases NO release and expression of NO synthase mainly in the ipsilateral side of the gracile nucleus,while the cardiovascular effects and analgesic responses to EA at ST36 are changed by influences of l-arginine-derived NO synthesis in the ipsilateral gracile nucleus in *** stimuli-induced release of NOergic molecules and neuropeptides exist high levels in the acupoints,which contain rich neuronal components and blood *** NOergic molecules at acupoints cause axon reflexes during the stimuli,which elevate cutaneous blood *** NOergic molecules and local blood flow may spread over acupoints one after another along the meridian lines differing from nerve pathways following the stimuli to induce *** same types of stimula

关键词： Axon reflex Nitric oxide Biophysical approaches Calcitonin related polypeptide Dorsal funiculus tract Meridian system

Effect of heat treatment on the microstructure,mechanical properties and fracture behaviors of ultra-high-strength SiC/Al-Zn-Mg-Cu composites

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and materials 2024年第10期31卷 2233-2243页

作者： Guonan ma Shize Zhu Dong Wang Peng Xue BolüXiao Zongyi ma Shi-changxu Innovation center for Advanced materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Centre of Excellence for Advanced materials Dongguan 523808China

A high-zinc composite,12.ol%SiC/Al-13.3 Zn-3.2. Mg-1.07Cu(wt%),with an ultra-high-strength of 781 MPa was success-fully fabricated through a powder metallurgy method,followed by an extrusion *** effects of solid-solution and aging heat treat-ments on the microstructure and mechanical properties of the composite were extensively *** with a single-stage sol-id-solution treatment,a two-stage solid-solution treatment(470℃/1 h+480℃/1 h)exhibited a more effective solid-solution strengthen-ing owing to the higher degree of solid-solution and a more uniform *** to the aging hardness curves of the com-posite,the optimized aging parameter(100℃/2. h)was *** the aging temperature and time resulted in finer and more uniform nanoscale precipitates but only yielded a marginal increase in tensile *** fractography analysis revealed that intergranu-lar cracking and interface debonding were the main fracture mechanisms in the ultra-high-strength SiC/Al-Zn-Mg-Cu *** regions,such as the SiC/Al interface containing numerous compounds and the precipitate-free zones at the high-angle grain boundaries,were identified as significant factors limiting the strength enhancement of the *** compounds,including MgO,MgZn2.and Cu5Zn8,reduced the interfacial bonding strength,leading to interfacial debonding.

关键词： metal matrix composites heat treatment interfacial reaction mechanical properties fracture mechanism

Bio-Based Waterborne Poly(Vanillin-Butyl Acrylate)/MXene Coatings for Leather with Desired Warmth Retention and Antibacterial Properties

在线全文

学校读者我要写书评

暂无评论

Engineering 2024年第5期36卷 250-263页

作者： Jianzhong ma Li ma Lei Zhang Wenbo Zhang Qianqian Fan Buxing Han College of Bioresources Chemical and materials Engineering Shaanxi University of Science and TechnologyXi’an 710021China Xi’an Key Laboratory of Green Chemicals and Functional materials Xi’an 710021China College of Chemistry and Chemical Engineering Shaanxi University of Science and TechnologyXi’an 710021China Shaanxi Collaborative Innovation center of Industrial Auxiliary Chemistry and Technology Shaanxi University of Science and TechnologyXi’an 710021China Institute of Chemistry Chinese Academy of SciencesBeijing 100190China

This study presents a solvent-free,facile synthesis of a bio-based green antibacterial agent and aromatic monomer methacrylated vanillin(MV)using *** resulting MV not only imparted antibacterial properties to coatings layered on leather,but could also be employed as a green alternative to petroleum-based carcinogen styrene(St).Herein,MV was copolymerized with butyl acrylate(BA)to obtain waterborne bio-based P(MV-BA)miniemulsion via miniemulsion ***,MXene nanosheets with excellent photothermal conversion performance and antibacterial properties,were introduced into the P(MV-BA)miniemulsion by ultrasonic *** the gradual solidification of P(MV-BA)/MXene nanocomposite miniemulsion on the leather surface,MXene gradually migrated to the surface of leather coatings due to the cavitation effect of ultrasonication and amphiphilicity of MXene,which prompted its full exposure to light and bacteria,exerting the maximum photothermal conversion efficiency and significant antibacterial *** particular,when the dosage of MXene nanosheets was 1.4 wt%,the surface temperature of P(MV-BA)/MXene nanocomposite miniemulsioncoated leather(PML)increased by about 15℃ in an outdoor environment during winter,and the antibacterial rate against Escherichia coli and Staphylococcus aureus was nearly 100%under the simulated sunlight treatment for 30 ***,the introduction of MXene nanosheets increased the air permeability,water vapor permeability,and thermal stability of these *** study provides a new insight into the preparation of novel,green,and waterborne bio-based nanocomposite coatings for leather,with desired warmth retention and antibacterial *** can not only realize zerocarbon heating based on sunlight in winter,reducing the use of fossil fuels and greenhouse gas emissions,but also improve ability to fight off invasion by harmful bacteria,viruses,and other microorganisms.

关键词： MXene nanosheets Vanillin Styrene substitute Leather coating Photothermal conversion Warmth retention Antibacterial properties

Two-Dimensional Metallophthalocyanine Nanomaterials for Electrocatalytic Energy Conversion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy & Environmental materials 2024年第4期7卷 364-385页

作者： Xinqi Wang Shaohui Sun Jiahao Yao Hao Wan Renzhi ma Wei ma School of Chemical Engineering and Zhongyuan Critical Metals Laboratory Zhengzhou University Research center for materials Nanoarchitectonics (maNA) National Institute for Materials Science (NIMS)

Crowing energy demand drives the rapid development of clean and reliable energy *** the past years,the exploration of novel materials with considerable efficiency and durability has drawn attention in the area of elec... 详细信息

关键词： conjugated nanostructure electrocatalysis 2. metallophthalocyanines

Supported Recyclable Metal-free Frustrated Lewis Pair Catalyst for Catalytic Hydrogenation of Substituted Pyridines to Piperidines

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese univ.rsities 2024年第4期40卷 682-689页

作者： ma Shaohua TANG Zhiyong CAS Key Laboratory for Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing100190P.R.China univ.rsity of Chinese Academy of Sciences Beijing100049P.R.China

The construction of heterogeneous frustrated Lewis pairs(FLPs)catalysts is crucial for realizing highly efficient and recyclable pyridines catalytic *** this work,we prepared a recyclable heterogenous FLPs catalyst CMP-BF with conjugated microporous polymer CMP-ethynyl as the support via self-catalyzed 1,1-carboboration reaction with commercial Lewis acid B(C_(6)F_(5))_(3).The as-synthesized CMP-BF demonstrates superior heterogenous catalytic hydrogenation performance(conversion>99%),and considerable stability(84%conversion after three cycles)in recyclable hydrogenation of 2.*** work provides insights into the fabrication and catalytic application of recyclable heterogenous FLP catalysts.

关键词： Pyridine hydrogenation Frustrated Lewis pair Conjugated microporous polymer

Spatial Distribution Pattern and Influencing Factors of Bed-and-breakfasts(B&Bs)from the Perspective of Urban-rural Differences:A Case Study of Jiaodong Peninsula,China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Geographical Science 2024年第4期34卷 752-763页

作者： WANG Xinyue ma Qian management College Ocean University of ChinaQingdao 266100China

There are significant differences between urban and rural bed-and-breakfasts(B&Bs)in terms of customer positioning,economic strength and spatial *** identifying the differences in spatial characteristics and influencing factors of each type,is essential for creating urban and rural B&B agglomeration *** study used density-based spatial clustering of applications with noise(DBSCAN)and the multi-scale geographically weighted regression(MGWR)model to explore similarities and differences in the spatial distribution patterns and influencing factors for urban and rural B&Bs on the Jiaodong Peninsula of China from 2.10 to *** results showed that:1)both urban and rural B&Bs in Jiaodong Peninsula went through three stages:a slow start from 2.10 to 2.15,rapid development from 2.15 to 2.19,and hindered development from 2.19 to ***,urban B&Bs demonstrated a higher development speed and agglomeration intensity,leading to an increasingly evident trend of uneven development between the two sectors.2.The clustering scale of both urban and rural B&Bs continued to expand in terms of quantity and *** B&B clusters characterized by a limited number,but a higher likelihood of transitioning from low-level to high-level *** the number of rural B&B clusters steadily increased over time,their clustering scale was comparatively lower than that of urban B&Bs,and they lacked the presence of high-level clustering.3)In terms of development direction,urban B&B clusters exhibited a relatively stable pattern and evolved into high-level clustering centers within the main urban ***,rural B&Bs exhibited a more pronounced spatial diffusion effect,with clusters showing a trend of multi-center development along the coastline.4)Transport emerged as a common influencing factor for both urban and rural B&Bs,with the density of road network having the strongest explanatory power for their spatial *** terms of differences,populati

关键词： urban-rural bed-and-breakfasts(B&Bs) spatiotemporal evolution density-based spatial clustering of applications with noise(DBSCAN)model multi-scale geographically weighted regression(MGWR) Jiaodong Peninsula China