检索结果-南通市图书馆

Systematic Elastostatic Stiffness Model of Over-Constrained Parallel Manipulators Without Additional Constraint Equations

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2024年第4期37卷 258-276页

作者： Chao Yang Wenyong Yu Wei Ye Qiaohong Chen Fengli Huang College of Mechanical and Electrical Engineering Jiaxing UniversityJiaxing 314001ZhejiangChina Zhejiang Siekon Transmission Technology Co. Ltd.Jiaxing 314001ZhejiangChina National and Local Joint Engineering Research Center of Reliability Analysis and Testing for Mechanical and Electrical Products Zhejiang Sci-Tech UniversityHangzhou 310018ZhejiangChina School of Computer science and Technology Zhejiang Sci-Tech UniversityHangzhou 310018ZhejiangChina

The establishment of an elastostatic stiffness model for over constrained parallel manipulators(PMs),particularly those with over constrained subclosed loops,poses a challenge while ensuring numerical *** study addresses this issue by proposing a systematic elastostatic stiffness model based on matrix structural analysis(MSA)and independent displacement coordinates(IDCs)extraction *** begin,the closed-loop PM is transformed into an open-loop PM by eliminating constraints.A subassembly element is then introduced,which considers the flexibility of both rods and *** approach helps circumvent the numerical instability typically encountered with traditional constraint *** IDCs and analytical constraint equations of nodes constrained by various joints are summarized in the appendix,utilizing multipoint constraint theory and singularity analysis,all unified within a single coordinate ***,the open-loop mechanism is efficiently closed by referencing the constraint equations presented in the appendix,alongside its elastostatic *** proposed method proves to be both modeling and computationally efficient due to the comprehensive summary of the constraint equations in the Appendix,eliminating the need for additional *** example utilizing an over constrained subclosed loops demonstrate the application of the proposed *** conclusion,the model proposed in this study enriches the theory of elastostatic stiffness modeling of PMs and provides an effective solution for stiffness modeling challenges they present.

关键词： Parallel manipulator Elastostatic stiffness model Matrix structural analysis Subassembly element Independent displacement coordinates

维普期刊数据库

Outstanding proton conductivity over wide temperature and humidity ranges and enhanced mechanical, thermal stabilities for surface-modified MIL-101-Cr-NH2/Nafion composite membranes

在线全文

学校读者我要写书评

暂无评论

GREEN ENERGY & ENVIRONMENT 2024年第11期9卷 1734-1746页

作者： Li, Xu Zhang, Dongwei Chen, Si Geng, Yingzhao Liu, Yong Qian, Libing Chen, Xi Li, Jingjing Fang, Pengfei He, Chunqing Wuhan Univ Sch Phys & Technol Key Lab Nucl Solid State Phys Hubei Prov Wuhan 430072 Peoples R China Hubei Univ sci & Technol Sch Nucl Technol & Chem & Biol Xianning 437100 Peoples R China Foshan Univ Sch Mat Sci & Hydrogen Energy Guangdong Key Lab Hydrogen Energy Technol Foshan 528000 Peoples R China

High-performance proton exchange membranes are of great importance for fuel cells. Here, we have synthesized polycarboxylate plasticizer modified MIL-101-Cr-NH2 (PCP-MCN), a kind of hybrid metal organic framework, which exhibits a superior proton conductivity. PCP-MCN nanoparticles are used as additives to fabricate PCP-MCN/Nafion composite membranes. Microstructures and characteristics of PCP-MCN and these membranes have been extensively investigated. Significant enhancement in proton conduction for PCP-MCN around 55 degrees C is interestingly found due to the thermal motion of the PCP molecular chains. Robust mechanical properties and higher thermal decomposition temperature of the composite membranes are directly ascribed to strong intermolecular interactions between PCP-MCN and Nafion side chains, i.e., the formation of substantial acid-base pairs (-SO3 ...H+-NH-), which further improves compatibility between additive and Nafion matrix. At the same humidity and temperature condition, the water uptake of composite membranes significantly increases due to the incorporation of porous additives with abundant functional groups and thus less crystallinity degree in comparison to pristine Nafion. Proton conductivity (sigma) over wide ranges of humidities (30 100% RH at 25 degrees C) and temperatures (30 98 degrees C at 100% RH) for prepared membranes is measured. The sigma in PCPMCN/Nafion composite membranes is remarkably enhanced, i.e. 0.245 S/cm for PCP-MCN-3wt.%/Nafion is twice that of Nafion membrane at 98 degrees C and 100% RH, because of the establishment of well-interconnected proton transport ionic water channels and perhaps faster protonation- deprotonation processes. The composite membranes possess weak humidity-dependence of proton transport and higher water uptake due to excellent water retention ability of PCP-MCN. In particular, when 3 wt.% PCP-MCN was added to Nafion, the power density of a single-cell fabricated with this composite membrane reaches imp

关键词： Nafion composite membrane Surface-modified MIL-101-Cr-NH2 Proton conductivity Single-cell performance METAL-ORGANIC FRAMEWORK FUEL-CELLS GRAPHENE OXIDE HYBRID MEMBRANE NAFION MATRIX ACID DURABILITY SUPERPLASTICIZERS ANNIHILATION DENSITY

Study on preparation,characterization and application of mixed-colorants thermochromic microcapsules

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第5期88卷 89-97页

作者： Lan Zhou Jingpeng Ye Qinze Cai Guojin Liu Mehran Dadgar Guocheng Zhu Guoqing Zhang College of Textile science and Engineering (International Institute of Silk) Zhejiang Sci-Tech UniversityHangzhou310018China School of Materials science& Engineering Zhejiang Sci-Tech UniversityHangzhou310018China Department of Textile University of NeyshaburAdib BoulevardKhorasan Razavi ProvinceIran Zhejiang Charming Dyeing and Finishing Co. LtdJiaxing314500China Zhejiang Provincial Innovation Center of Advanced Textile Technology Shaoxing312000China

In order to expand the color-change range and make the discoloration temperature suitable for the daily textiles,a new formulation of mixed-colorants thermochromic core material is designed,in which crystal violet lactone(CVL)is the basic color former,bisphenol A(BPA)is the developer,especially the solvent-based dye and dodecyl dedecanoate are used as the extended dye and the solvent,*** electron microscope(SEM),differential scanning calorimeter(DSC)and thermogravimetric analyzer(TGA)were applied to study the morphology,encapsulation rate,non-isothermal crystallization behavior and thermal stability of the mixed-colorant thermochromic microcapsules(MCTMs)prepared by in-situ *** results show that MCTMs have good sphericity,uniform particle size,good thermal stability and the encapsulation rate can reach 86.73%.Under the non-isothermal conditions,the encapsulation of formaldehyde-melamine resin wall material can slightly reduce the crystallization rate of the solvent,but does not affect the relative crystallinity,thermal properties and discoloration sensitivity of the core *** the variety of ambient temperatures in the range of 20–35℃,the printed cotton fabrics with MCTMs could change color reversibly between different tones with good reliability and durability,and exhibit more gorgeous colors than the common thermochromic materials.

关键词： Thermochromic microcapsule Color-change range Phase-change material Crystallization behavior

An integrative risk assessment approach to enhancing patient safety in Continuous Renal Replacement Therapy (CRRT)

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 SAFETY sciENCE AND RESILIENCE 2024年第3期5卷 344-354页

作者： Saad, Ahmed Alsadi, Juman Al-Absi, Dima Tareq Almulla, Muhra Simsekler, Mecit Can Emre Sadeq, Ahmed Adel Omar, Fahad Basha, Mazhar Khatab, Islam Abu Khater, Noha Molesi, Andrea Anwar, Siddiq Khalifa Univ sci & Technol Dept Management Sci & Engn POB 127788 Abu Dhabi U Arab Emirates Sheikh Shakhbout Med City Dept Pharm Abu Dhabi U Arab Emirates Sheikh Shakhbout Med City Crit Care Dept Abu Dhabi U Arab Emirates Sheikh Shakhbout Med City Dept Internal Med Abu Dhabi U Arab Emirates

Continuous Renal Replacement Therapy (CRRT) serves as an intervention strategy for the management of acute kidney injury (AKI) in critically ill patients. However, owing to its complex nature and the potential for complications, the implementation of CRRT demands continuous monitoring to prevent patient safety risks. This study aims to identify and validate prevalent risks linked to CRRT within a real-world clinical setting, intending to propose preventive measures grounded in expert insights. To systematically categorize and visually depict the risks, their consequences, preventive measures, and recovery controls, our study employed the Bowtie method in conjunction with the Systems Engineering Initiative for Patient Safety (SEIPS) model. In addition to considering patient-related factors that exhibit variability among critically ill individuals, our key findings showed that the most influential risks impacting the effective delivery of CRRT are incidents of clotted filters, bleeding risks arising from the necessity of anticoagulation for filter efficacy, vascular catheter-related bloodstream infections, variations in proficiency levels among healthcare professionals regarding CRRT modalities, especially in operating the CRRT machines, high nursing workload, frequent nursing turnover, occurrences of hypophosphatemia, variability in CRRT prescribing patterns, and issues related to communication among stakeholders. This research sheds light on the primary risks associated with CRRT and provides practical and viable strategies for effective management. Furthermore, the Bowtie diagram developed as part of this study serves as a valuable tool for visually representing the healthcare system and facilitating the identification of system-related risks within healthcare settings.

关键词： Patient safety Risk management CRRT Continuous Renal Replacement Therapy Acute kidney injury Bowtie method SEIPS CRITICALLY-ILL PATIENTS ANTICOAGULATION DESIGN

Some Physical Properties of CuTlSe Alloy

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 Materials science & Technology 2001年第2期17卷 229-232页

作者： A.Abdel All Physics Department, faculty of science , Helwan University, Cairo, Egypt K.A.Sharaf Physics Department, faculty of science, Al-Azhar University for Girls, Cairo, Egypt A.Elshafie Physics Department, faculty of science, Menoufia University, She Helwan Univ Fac Sci Dept Phys Cairo Egypt Al Azhar Univ Girls Dept Phys Fac Sci Cairo Egypt Menoufia Univ Fac Sci Dept Phys Shibin Al Kawm Egypt

The structure and optical properties of Cu0.1Tl2Se3 alloy was studied. X-ray analysis showed that the polycrystalline powder consists of a mixture of two phases Cu3jTlSe2 (monoclinic) and TISe (tetragonal). Chalcopyrite phase CuTISe2 can be obtained by annealing the powder at 250'C for 1 h. Thin film with a monoclinic phase of Cu3TlSe2 was obtained for the thick film (0.7 um). The optical parameters a, n, k, e' and e' and the energy gap were calculated. The thermoelectric power measurements showed that S has a positive polarity over the whole range of temperature.

关键词： Cu Some Physical Properties of CuTlSe Alloy

维普期刊数据库

DMT:A model detecting multispecies of tea buds in multi-seasons

在线全文

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2024年第1期17卷 199-208页

作者： Taojie Yu Jianneng Chen Zhiwei Chen Yatao Li Junhua Tong Xiaoqiang Du School of Mechanical Engineering Zhejiang Sci-Tech UniversityHangzhou 310018China Key Laboratory of Transplanting Equipment and Technology of Zhejiang Province Hangzhou 310018China

In China,tea products made from fresh leaves characterized by one leaf with one bud(1L1B)are classified as“Famous Tea”,which has better taste and higher economic value,but suffers from a labor *** at picking automation,existing studies focus on visual detection of 1L1B,but algorithm validation is limited to a specific variety of tea sprouting in a certain harvest season at a certain location,which limits the engineering application of developed tea picking robots working in various natural tea *** address this gap,a deep learning model DMT(detecting multispecies of tea)based on YOLOX-S was proposed in this *** DMT network takes YOLOX-S as a baseline and adds ECA-Net to the CSP Darknet and FPN of *** average precision(AP),precision,and recall of DMT are 94.23%,93.39%,and 88.02%,respectively,for detecting 1L1B sprouting in spring;93.92%,93.56%,and 87.88%,respectively,for detecting 1L1Bsprouting in *** experimental results are better than those of the five current object detection *** fine-tuning the DMT network with another dataset composed of multiple tea varieties,the DMT network can detect 1L1B for different varieties of tea in multiple picking *** results can promote the engineering application of picking automation of fresh tea leaves.

关键词： tea buds detection model multispecies of tea multi-season

Phase induced localization transition

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 Physics B 2024年第10期33卷 362-365页

作者： Tong Liu Xingbo Wei Youguo Wang School of science Nanjing University of Posts and TelecommunicationsNanjing 210003China Department of Physics and Key Laboratory of Optical Field Manipulation of Zhejiang Province Zhejiang Sci-Tech UniversityHangzhou 310018China

Localization phenomenon is an important research field in condensed matter ***,due to the complexity and subtlety of disordered systems,new localization phenomena always emerge *** example,it is generally believed that the phase of the hopping term does not affect the localization properties of the system,so the calculation of the phase is often ignored in the study of ***,we introduce a quasiperiodic model and demonstrate that the phase change of the hopping term can significantly alter the localization properties of the system through detailed numerical simulations,such as the inverse participation ratio and multifractal *** phase-induced localization transition provides valuable information for the study of localization physics.

关键词： phase localization quasiperiodic

维普期刊数据库

The Influence of the Closure of the East Paleo-Tethys Ocean on Southern South China: Evidences from Kinematics and 40Ar/39Ar Geochronology of the Rongxian Ductile Shear Zone in Southeastern Guangxi

在线全文

学校读者我要写书评

暂无评论

ACTA GEOLOGICA SINICA-ENGLISH EDITION 2024年第5期98卷 1125-1140页

作者： Huang, Wenqiang Li, Saisai Xin, Liangwei Feng, Zuohai Zhang, Hongrui Geng, Jieli Liu, Kun Shi, Chunyan Guilin Univ Technol Collaborat Innovat Ctr Explorat Nonferrous Met Dep Guilin 541004 Guangxi Peoples R China Guilin Univ Technol Coll Earth Sci Guilin 541004 Guangxi Peoples R China Chinese Acad Geol sci Inst Geol Beijing 100037 Peoples R China Guilin Univ Technol Coll Tourism & Landscape Architecture Guilin 541004 Guangxi Peoples R China

The Triassic was a crucial period in the tectonic evolution of the South China Block. Research on tectonic deformation during this period provides information on intracontinental orogenic mechanisms in South China. In this study, alongside thermochronological analyses, we examine the macroscopic and microscopic structural features of the Rongxian ductile shear zone, located south of the Darongshan granite in the southeastern part of Guangxi Province, on the southern margin of South China. Sinistral shear is indicated by the characteristics of rotated sigma-type feldspar porphyroclasts, stretching lineations defined by elongated quartz grains and the orientations of quartz c-axes. LA-ICP-MS U-Pb dating of zircons from two samples of granitic mylonite and one of granite yielded ages of ca. 256 Ma. Furthermore, two samples of granitic mylonite yield muscovite Ar-40/Ar-39 plateau ages of 249-246 Ma. These results indicate that the Rongxian ductile shear zone resulted from Early Triassic deformation of the late Permian Darongshan granite. This deformation was likely related to the closure of the eastern Paleo-Tethys Ocean and the subsequent collision of the South China and Indochina blocks, during the early stage of the Indosinian orogeny.

关键词： ductile shear zone Ar-40/Ar-39 geochronology Triassic South China Block East Paleo-Tethys Ocean AILAOSHAN SUTURE ZONE ULTRAHIGH-TEMPERATURE METAMORPHISM ARC/BACK-ARC ASSEMBLAGES PLATE TECTONIC CYCLE TRUONG SON BELT VOLCANIC-ROCKS INDOSINIAN COLLISION PLASTIC-DEFORMATION MESOZOIC GRANITOIDS GRANULITE ENCLAVES

Davidson base as an appropriate base for the shell model in the case of 1p- and 1h- nuclei

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第10期76卷 94-100页

作者： Hadi Sobhani Yan-An Luo Amir Jalili Hassan Hassanabadi School of Physics Nankai University Department of Physics Zhejiang Sci-Tech University Institute of Theoretical Physics Faculty of Physics University of Warsaw Institute of Actuarial science and Data Analytics UCSI University

This study endeavors to develop an improved set of basis functions for nuclear shell-model calculations. The shell model, a well-established approach to understanding nuclear structure,typically employs the harmonic oscillator potential within the mean-field approximation. Given the extensive validation and consistency of harmonic oscillator results with experimental data,we propose a modification by incorporating a centrifugal term that converges toward the Davidson potential. This potential has been extensively studied, and we aim to extract relevant experimental data for the simplest cases in the shell model, namely one-particle and one-hole nuclei. A comprehensive comparison between the Davidson-based results and the harmonic oscillator calculations is presented to demonstrate the effectiveness of the new basis functions.

关键词： beta decay gamma transition nuclear structure shell-model calculations