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Optimizing mechanical properties of HIPS fabricated with low-cost desktop 3D printers:investigating the impact of process parameters

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Advances in Manufacturing 2024年第2期12卷 379-395页

作者： jin-Ting Xu Guang-Wei Zhang Man-Man Chen School of Automotive Engineering Dalian University of TechnologyDalian116024People’s Republic of China

Recently,low-cost desktop three-dimensional(3D)printers,employing the fused deposition modeling(FDM)technique,have gained widespread ***,most users cannot test the strength of printed parts,and little information is available about the mechanical properties of printed high-impact polystyrene(HIPS)parts using desktop 3D *** this study,the user-adjustable parameters of desktop 3D printers,such as crisscross raster orientation,layer thickness,and infill density,were *** experimental plans were designed using the Box-Behnken method,and tensile,3-point bending,and compression tests were carried out to determine the mechanical responses of the printed *** prediction models of the process parameters were regressed to produce the optimal combination of process *** experimental results showcase that the crisscross raster orientation has significant effects on the flexural and compression strengths,but not on the tensile *** an increase in the layer thickness,the tensile,flexural,and compression strengths first decreased and then increased,reaching their minimum values at approximately 0.16 mm layer *** addition,they all increased with an increase of infill *** was demonstrated that when the raster orientation,layer thickness,and infill density were 13.08°/–76.92°,0.09 mm,and 80%,respectively,the comprehensive mechanical properties of the printed HIPS were *** results can help end-users of desktop 3D printers understand the effects of process parameters on the mechanical properties,and offer practical suggestions for setting proper printing parameters for fabricating HIPS parts.

关键词： Desktop three-dimensional(3D)printers Fused deposition modeling(FDM) High-impact polystyrene(HIPS) Process parameters

Prescribed Performance Tracking Control of Time-Delay Nonlinear Systems With Output Constraints

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1557-1565页

作者： jin-Xi Zhang Kai-Di Xu Qing-Guo Wang IEEE the State Key Laboratory of Synthetical Automation for Process Industries Northeastern UniversityShenyang 110819China Institute of Artificial Intelligence and Future Networks Beijing Normal UniversityZhuhai 519087 Guangdong Key Laboratory of Artificial Intelligence and Multi-Modal Data Processing Beijing Normal University-Hong Kong Baptist University United International CollegeZhuhai 519087

The problem of prescribed performance tracking control for unknown time-delay nonlinear systems subject to output constraints is dealt with in this paper. In contrast with related works, only the most fundamental requirements, i.e., boundedness and the local Lipschitz condition, are assumed for the allowable time delays. Moreover, we focus on the case where the reference is unknown beforehand, which renders the standard prescribed performance control designs under output constraints infeasible. To conquer these challenges, a novel robust prescribed performance control approach is put forward in this ***, a reverse tuning function is skillfully constructed and automatically generates a performance envelop for the tracking error. In addition, a unified performance analysis framework based on proof by contradiction and the barrier function is established to reveal the inherent robustness of the control system against the time delays. It turns out that the system output tracks the reference with a preassigned settling time and good accuracy,without constraint violations. A comparative simulation on a two-stage chemical reactor is carried out to illustrate the above theoretical findings.

关键词： Nonlinear systems output constraints prescribed performance reference tracking time delays

Configuration Synthesis and Grasping Performance Analysis of Multi-Loop Coupling Capture Mechanism for Launch and Recovery of Torpedo-Shaped Autonomous Underwater Vehicle

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China Ocean Engineering 2024年第3期38卷 453-466页

作者： ZHANG Guo-xing XIA Xin-lu GUO jin-wei School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China

Research of capture mechanisms with strong capture adaptability and stable grasp is important to solve the problem of launch and recovery of torpedo-shaped autonomous underwater vehicles(AUVs).A multi-loop coupling capture mechanism with strong adaptability and high retraction rate has been proposed for the launch and recovery of torpedo-shaped AUVs with different morphological ***,the principle of capturing motion retraction is described based on the appearance characteristics of torpedo-shaped AUVs,and the configuration synthesis of the capture mechanism is carried out using the method of constrained chain ***,the screw theory is employed to analyze the degree of freedom(DoF)of the capture ***,the 3D model of the capture mechanism is established,and the kinematics and dynamics simulations are carried *** with the capture orientation requirements of the capture mechanism,the statics and vibration characteristics analyses are carried ***,considering the capture process and the underwater working environment,the motion characteristics and hydraulics characteristics of the capture mechanism are ***,a principle prototype is developed and the torpedo-shaped AUVs capture experiment is *** work provides technical reserves for the research and development of AUV capture special equipment.

关键词： capture mechanism torpedo-shaped AUVs configuration synthesis launch and recovery grasping performance analysis

Stereoselective Self-Assembly of Chiral Metalla[2]Catenanes and Lemniscular Macrocycles

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CCS Chemistry 2024年第8期6卷 2000-2010页

作者： Shu-jin Bao Hai-Ning Zhang Guo-Xin jin Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials State Key Laboratory of Molecular Engineering of PolymersDepartment of ChemistryFudan UniversityShanghai 200433

Designing and stereoselectively constructing chiral mechanically interlocked molecules(MIMs)is a goal that many chemists are pursuing due to their potential in the development of functional molecular machines involved in catalysis,sensing,and chiroptical ***,the synthesis of enantiopure supramolecular entities with crystallographic structures remains ***,the stereoselective self-assembly of chiral metalla[2]catenanes interlocked by two D-shaped macrocycles was realized by combining long binuclear half-sandwich organometallic Cp*Rh^(III)(Cp*=η^(5)-pentamethylcyclopentadienyl)clip and ditopic monodentate ligand incorporating L-leucine *** resulting metalla[2]catenane displayed unique co-conformational mechanical helical chirality characteristics arising from the chirality transfer of the chiral ***,decreasing the length of the binuclear Cp*Rh^(III)clip and adjusting the steric hindrance of the amino-acid side chains(L-alanine and L-phenylalanine)in the ligands resulted in two lemniscular macrocycles with left-handed(M)-twisted conformational *** the best of our knowledge,the synthesized macrocycles are the first family of homochiral abnormal lemniscate-shaped organometallic macrocycles featuring figure-eight ***[2]catenanes and macrocycles with opposite chirality were also generated by employing corresponding D-amino acid ligands,as evidenced by single-crystal X-ray diffraction,nuclear magnetic resonance,mass,and circular dichroism *** present study demonstrates that homochiral MIMs can be accessed readily using amino acid–containing ligands through rational molecular design.

关键词： stereoselective synthesis chirality metallacatenanes twisted macrocycles aminoacid residues

Do brood parasitic Common Cuckoos develop brood patches during the breeding season?

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Avian Research 2024年第3期15卷 363-368页

作者： Jun-Seo Go Hae-Ni Kim Sue-Jeong jin Myeong-Chan Cha Heesoo Lee jin-Won Lee Korea Institute of Ornithology&Department of Biology Kyung Hee University02447SeoulRepublic of Korea Bird Research SaeZiP 12504YangpyeongRepublic of Korea

Many birds develop brood patches on their ventral apterium under hormonal regulation to effectively transmit body heat to eggs during *** developed patch has several characteristics,including de-feathering,vascularization,and ***,little is known about whether avian brood parasites that do not incubate their eggs exhibit brood patch development during the breeding *** this study,we measured the size of the ventral apterium in 114 Common Cuckoos(Cuculus canorus)captured in the field throughout the breeding season and examined the appearance of the ventral apterium to confirm the development of brood *** also examined whether morphological traits and various factors correlated with the size of the ventral apterium(sternal apterium and abdominal apterium)and how it changed during the breeding *** found no clear signs of brood patch development in Common Cuckoos captured throughout the breeding season,indicating that they likely did not develop brood patches on the ventral apterium during this *** also found that ventral apterium size was positively correlated with wing length and body *** addition,Common Cuckoos with newly growing feathers on the boundary of the ventral apterium with pteryla were frequently observed as seasons progressed to the *** conclusion,Common Cuckoos exhibit neither brood patch development nor the vestigial characteristics of ancestral brood patches,except for the growth of feathers on boundary the ventral *** studies examining brood patches across different groups of avian brood parasites are valuable for enhancing our understanding of the developmental and physiological adaptations of avian brood parasites.

关键词： Brood parasitism Brood patch Common Cuckoo Pterylosis Re-feathering Ventral apterium

Flexible nanoimprint lithography enables high-throughput manufacturing of bioinspired microstructures on warped substrates for efficient III-nitride optoelectronic devices

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Science Bulletin 2024年第13期69卷 2080-2088页

作者： Siyuan Cui Ke Sun Zhefu Liao Qianxi Zhou Leonard jin Conglong jin Jiahui Hu Kuo-Sheng Wen Sheng Liu Shengjun Zhou Center for Photonics and Semiconductors School of Power and Mechanical EngineeringWuhan UniversityWuhan 430072China The Institute of Technological Sciences Wuhan UniversityWuhan 430072China Department of Mechanical and Mechatronics Engineering University of WaterlooWaterloo ONN2L 3G1Canada Jiangxi SMTC Semiconductor Co. Ltd.Nanchang 330096China

III-nitride materials are of great importance in the development of modern optoelectronics,but they have been limited over years by low light utilization rate and high dislocation densities in heteroepitaxial films grown on foreign substrate with limited refractive index contrast and large lattice ***,we demonstrate a paradigm of high-throughput manufacturing bioinspired microstructures on warped substrates by flexible nanoimprint lithography for promoting the light extraction *** design a flexible nanoimprinting mold of copolymer and a two-step etching process that enable high-efficiency fabrication of nanoimprinted compound-eye-like Al2O3 microstructure(NCAM)and nanoimprinted compound-eye-like SiO_(2)microstructure(NCSM)template,achieving a 6.4-fold increase in throughput and 25%savings in economic costs over stepper projection *** to NCAM template,we find that the NCSM template can not only improve the light extraction capability,but also modulate the morphology of AlN nucleation layer and reduce the formation of misoriented GaN grains on the inclined sidewall of microstructures,which suppresses the dislocations generated during coalescence,resulting in 40%reduction in dislocation *** study provides a low-cost,high-quality,and high-throughput solution for manufacturing microstructures on warped surfaces of III-nitride optoelectronic devices.

关键词： Flexible nanoimprint lithography Bioinspired Micro-and nano-manufacturing III-nitride epitaxy Optoelectronic devices

FeNi Prussian blue analogues on highly graphitized carbon nanosheets as efficient glucose sensors

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Rare Metals 2024年第6期43卷 2730-2738页

作者： jin-Hang Xue Qiu-Hong Sun Cheng Han Yuan-Dong Yang Shao-Jie Xu Qi-Peng Li jin-Jie Qian College of Life and Environmental Science Wenzhou UniversityWenzhou 325000China College of Chemistry and Materials Engineering Wenzhou UniversityWenzhou 325000China College of Chemistry and Chemical Engineering Zhaotong UniversityZhaotong 657000China

Meeting the continuous glucose monitoring requirements of individuals necessitates the research and development of sensors with high sensitivity and *** this study,a straightforward strategy was proposed for synthesizing ultra-thin oxygen-rich graphitized carbon nanosheets(denoted as GCS-O).These nanosheets are obtained by calcining a topologically two-dimensional indium-based coordination ***,the growth of FeNi Prussian blue analogue(PBA)on GCS-O effectively introduces active sites and increases the nitrogen content within the carbonaceous *** resulting FeNi-PBA/GCS-O composite exhibits excellent glucose sensing performance with a broad linear range of 1 to 1300μmol·L^(-1).Meanwhile,it also achieves a high sensitivity of 2496μA·mmol^(-1)·L·cm^(-2),a limit of detection of 100nmol·L^(-1)(S/N=3),and commendable long-term *** relatively simple synthesis process,exceptional sensitivity,and satisfactory electrochemical sensing performance of FeNi-PBA/GCS-O open up new directions for biosensor applications.

关键词： Coordination polymer Carbon nanosheet Prussian blue analogue Surface reconstruction Glucose oxidation

Coordinate Rule of Law Efforts in Both Domestic and Foreign-Related Matters

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Social Sciences in China 2024年第1期45卷 71-88页

作者： Huang jin Academy for the Rule of Law China University of Political Science and Law

Taking a coordinated approach to promoting the rule of law at home and in matters involving foreign parties stands as one of the essentials of Xi jinping Thought on the Rule of *** profound essence of this concept is predominantly articulated through the dialectic nexus between the rule of law at home and in matters involving foreign parties and the foundational necessities and underlying principles for their coordinated *** concept is intellectually rooted in the legal theory of socialist rule of law with Chinese characteristics,the theory of major-country diplomacy with Chinese characteristics,modern progressive theories of international law,and the exemplary facets of traditional Chinese *** is aligned with contemporary trends and in harmony with the need to take a holistic approach to imperatives at home and *** philosophy underscores the approach to building a human community with a shared future through the rule of law,guaranteeing the fruition of national strategic *** resonates with profound contemporary,integrative,international,and strategic ***,the focus should be on fostering the development of foreign-related rule of law,maintaining the correct equilibrium between the dyad of rule of law in domestic and foreign-related *** is imperative to augment strategic design and institutional construction in the realm of rule of law on issues related to foreign parties,step up research on and practical application of international law,and reinforce the cultivation of legal professionals in this area to take a coordinated approach to advance the rule of law at home and in matters involving foreign parties.

关键词： comprehensive law-based governance rule of law in domestic matters foreignrelated rule of law rule of law in international matters

Tau truncation in the pathogenesis of Alzheimer's disease:a narrative review

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Neural Regeneration Research 2024年第6期19卷 1221-1232页

作者： Dandan Chu Xingyue Yang jing Wang Yan Zhou jin-Hua Gu jin Miao Feng Wu Fei Liu Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology ProductsCoinnovation Center of NeuroregenerationNantong UniversityNantongJiangsu ProvinceChina Department of Pharmacology School of PharmacyNantong UniversityNantongJiangsu ProvinceChina Department of Biochemistry and Molecular Biology School of MedicineNantong UniversityNantongJiangsu ProvinceChina Department of Clinical Pharmacy Affiliated Maternity and Child Health Care Hospital of Nantong UniversityNantong UniversityNantongJiangsu ProvinceChina Laboratory of Animal Center Nantong UniversityNantongJiangsu ProvinceChina Department of Neurochemistry Inge Grundke-Iqbal Research FloorNew York State Institute for Basic Research in Developmental DisabilitiesStaten IslandNYUSA

Alzheimer's disease is characterized by two major neuropathological hallmarks—the extracellularβ-amyloid plaques and intracellular neurofibrillary tangles consisting of aggregated and hyperphosphorylated Tau *** studies suggest that dysregulation of the microtubuleassociated protein Tau,especially specific proteolysis,could be a driving force for Alzheimer's disease *** physiologically promotes the assembly and stabilization of microtubules,whereas specific truncated fragments are sufficient to induce abnormal hyperphosphorylation and aggregate into toxic oligomers,resulting in them gaining prion-like *** addition,Tau truncations cause extensive impairments to neural and glial cell functions and animal cognition and behavior in a fragment-dependent *** review summarizes over 60 proteolytic cleavage sites and their corresponding truncated fragments,investigates the role of specific truncations in physiological and pathological states of Alzheimer's disease,and summarizes the latest applications of strategies targeting Tau fragments in the diagnosis and treatment of Alzheimer's disease.

关键词： Alzheimer's disease cleavage site diagnosis marker neurofibrillary tangles phosphorylation Tau Tau aggregation therapy truncation