检索结果-南通市图书馆

Crack elimination and strength enhancement mechanisms of selective laser melted Si-modified Al−Mn−Mg−Er−Zr alloy

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2024年第8期34卷 2431-2441页

作者： Jiang yu Yao-xiang GENG Hong-bo JU zhi-jie ZHANG Jun-hua XU School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China Department of Mechanical Engineering CEMMPRE-Centre for Mechanical Engineering Materials and ProcessesUniversity of CoimbraCoimbraPortugal

In order to increase the processability and process window of the selective laser melting(SLM)-fabricated Al−Mn−Mg−Er−Zr alloy,a novel Si-modified Al−Mn−Mg−Er−Zr alloy was *** effect of Si alloying on the surface quality,processability,microstructure,and mechanical properties of the SLM-fabricated alloy was *** results showed that introducing Si into the Al−Mn−Mg−Er−Zr alloy prevented balling and keyhole formation,refined the grain size,and reduced the solidification temperature,which eliminated cracks and increased the processability and process window of the *** maximum relative density of the SLM-fabricated Si/Al−Mn−Mg−Er−Zr alloy reached 99.6%.The yield strength and ultimate tensile strength of the alloy were(371±7)MPa and(518±6)MPa,*** values were higher than those of the SLM-fabricated Al−Mn−Mg−Er−Zr and other Sc-free Al−Mg-based alloys.

关键词： selective laser melting Al−Mn−Mg−Er−Zr−Si alloy surface roughness processability mechanical properties

Reinforcement learning based adaptive control for uncertain mechanical systems with asymptotic tracking

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4期34卷 19-28页

作者： xiang-long Liang zhi-kai Yao Yao-wen Ge Jian-yong Yao School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China College of Automation&College of Artificial Intelligence Nanjing University of Post and TelecommunicationNanjing210023China

This paper mainly focuses on the development of a learning-based controller for a class of uncertain mechanical systems modeled by the Euler-Lagrange *** considered system can depict the behavior of a large class of engineering systems,such as vehicular systems,robot manipulators and *** these systems are often characterized by highly nonlinear characteristics,heavy modeling uncertainties and unknown perturbations,therefore,accurate-model-based nonlinear control approaches become *** by the challenge,a reinforcement learning(RL)adaptive control methodology based on the actor-critic framework is investigated to compensate the uncertain mechanical *** approximation inaccuracies caused by RL and the exogenous unknown disturbances are circumvented via a continuous robust integral of the sign of the error(RISE)control *** from a classical RISE control law,a tanh(·)function is utilized instead of a sign(·)function to acquire a more smooth control *** developed controller requires very little prior knowledge of the dynamic model,is robust to unknown dynamics and exogenous disturbances,and can achieve asymptotic output ***,co-simulations through ADAMS and MATLAB/Simulink on a three degrees-of-freedom(3-DOF)manipulator and experiments on a real-time electromechanical servo system are performed to verify the performance of the proposed approach.

关键词： Adaptive control Reinforcement learning Uncertain mechanical systems Asymptotic tracking

Probiotics intervention in colorectal cancer:From traditional approaches to novel strategies

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2024年第1期137卷 8-20页

作者： Suki Ha xiang Zhang Jun yu Institute of Digestive Disease and Department of Medicine and Therapeutics State Key Laboratory of Digestive DiseaseLi Ka Shing Institute of Health SciencesThe Chinese University of Hong KongHong Kong SARChina

The intestine harbors a large population of microorganisms that interact with epithelial cells to maintain host healthy physiological *** intestinal microbiota engage in the fermentation of non-digestible nutrients and produce beneficial metabolites to regulate host homeostasis,metabolism,and immune *** disruption of microbiota,known as dysbiosis,has been implicated in many intestinal diseases,including colorectal cancer(CRC).As the third most common cancer and the second leading cause of cancer-related death worldwide,CRC poses a significant health *** is an urgent need for novel interventions to reduce CRC incidence and improve clinical *** the intestinal microbiota has emerged as a promising approach for CRC prevention and *** research efforts in CRC probiotics primarily focus on reducing the incidence of CRC,alleviating treatment-related side effects,and potentiating the efficacy of anticancer therapy,which is the key to successful translation to clinical *** paper aims to review the traditional probiotics and new interventions,such as next-generation probiotics and postbiotics,in the context of *** underlying mechanisms of probiotic anti-cancer effects are also discussed,including the restoration of microbial composition,reinforcement of gut barrier integrity,induction of cancer cell apoptosis,inactivation of carcinogens,and modulation of host immune *** paper further evaluates the novel strategy of probiotics as an adjuvant therapy in boosting the efficacy of chemotherapy and *** all the promising findings presented in studies,the evaluation of potential risks,optimization of delivery methods,and consideration of intra-patient variability of gut microbial baseline must be thoroughly interpreted before bench-to-bedside translation.

关键词： colorectal cancer probiotics gut microbiota dysbiosis adjuvant therapy immune modulation gut barrrier

Mean field game of optimal relative investment with jump risk

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2024年第5期67卷 1159-1188页

作者： Lijun Bo Shihua Wang xiang yu School of Mathematics and Statistics Xidian UniversityXi'an 710126China School of Mathematical Sciences University of Science and Technology of ChinaHefei 230026China Department of Applied Mathematics The Hong Kong Polytechnic UniversityHong KongChina

In this paper,we study the n-player game and the mean field game under the constant relative risk aversion relative performance on terminal wealth,in which the interaction occurs by peer *** the model with n agents,the price dynamics of underlying risky assets depend on a common noise and contagious jump risk modeled by a multi-dimensional nonlinear Hawkes *** a continuum of agents,we formulate the mean field game problem and characterize a deterministic mean field equilibrium in an analytical form under some conditions,allowing us to investigate some impacts of model parameters in the limiting model and discuss some financial ***,based on the mean field equilibrium,we construct an approximate Nash equilibrium for the n-player game when n is sufficiently *** explicit order of the approximation error is also derived.

关键词： relative performance contagious jump risk mean field game with jumps mean field equilibrium approximate Nash equilibrium

Hydrodynamic Performance of An Integrated System of Breakwater and A Multi-Chamber OWC Wave Energy Converter

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第4期38卷 543-556页

作者： NING De-zhi ZHANG xiang-yu WANG Rong-quan ZHAO Ming State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China Dalian Key Laboratory of Offshore Renewable Energy Dalian University of TechnologyDalian 116024China School of Computing Engineering and MathematicsUniversity of Western SydneyPenrith NSW 2751Australia

A multi-chamber oscillating water column wave energy converter(OWC-WEC)integrated to a breakwater is *** hydrodynamic characteristics of the device are analyzed using an analytical model based on the linear potential flow theory.A pneumatic model is employed to investigate the relationship between the air mass flux in the chamber and the turbine *** effects of chamber width,wall draft and wall thickness on the hydrodynamic performance of a dual-chamber OWC-WEC are *** results demonstrate that the device,with a smaller front wall draft and a wider rear chamber exhibits a broader effective frequency *** device with a chamber-width-ratio of 1:3 performs better in terms of power ***,results from the analysis of a triplechamber OWC-WEC demonstrate that reducing the front chamber width and increasing the rearward chamber width can improve the total performance of the *** the number of chambers from 1 to 2 or 3 can widen the effective frequency bandwidth.

关键词： oscillating water column power extraction efficiency potential flow theory wave energy converter multi-chamber

Moyamoya syndrome may result from psoriasis: Four case reports

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第10期12卷 1830-1836页

作者： zhi-Ying Chen Xiao-Qin yu yuan-yuan xiang Ling-Hua Liu Xiao-Ping Yin Department of Neurology The Affiliated Hospital of Jiujiang UniversityJiujiang 332000Jiangxi ProvinceChina Department of Dermatology The Affiliated Hospital of Jiujiang UniversityJiujiang 332000Jiangxi ProvinceChina

BACKGROUND Moyamoya syndrome(MMS)is a group of diseases that involves more than one underlying disease and is accompanied by moyamoya vascular *** is a chronic immune skin disease closely linked to high blood pressure and heart ***,psoriasis-related MMS has not been *** SUMMARY We collected data on patients with stroke due to MMS between January 2017 and December 2019 and identified four cases of *** histories,imaging,and hematological data were *** average age of the initial stroke onset was 58.25±11.52 years;three cases of hemorrhagic and one case of ischemic stroke were *** average duration from psoriasis confirmation to the initial MMS-mediated stroke onset was 17±3.56 *** MMS-related stenoses involved the bilateral cerebral arteries:Suzuki grade III in one case,grade IV in two cases,and grade V in one *** elevated plasma interleukin-6 levels were observed in four *** patients had abnormally elevated immunoglobulin E levels,and two had *** four patients received medication instead of *** an average follow-up time of 2 years,two causing transient ischemic attacks occurred in two patients,and no hemorrhagic events *** Psoriasis may be a potential risk factor for *** with psoriasis should be screened for MMS when they present with neurological symptoms.

关键词： Moyamoya syndrome Psoriasis Stroke Interleukin-6 Immune Hypertension Case report

Transition-Metal-Free Allylic Defluorination Cross-Electrophile Coupling Employing Rongalite

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

Chinese Journal of Chemistry 2024年第12期42卷 1360-1366页

作者： xiang-Long Chen Chun-Yan Wu Dong-Sheng Yang Bo-Cheng Tang Huai-yu Wang zhi-Cheng yu Anling Li Yan-Dong Wu An-Xin Wu National Key Laboratory of Green Pesticide International Joint Research Center for Intelligent Biosensor Technology and HealthCollege of ChemistryCentral China Normal UniversityWuhanHubei 430079China state Key Laboratory of Chemical Biology and Drug Discovery Department of Applied Biology and Chemical Technology The HongKong Polytechnic UniversityKowloonHong Kong SARChina Department of Clinical Laboratory Center for Gene Diagnosisand Program of Clinical Laboratory MedicineZhongnan Hospital of Wuhan UniversityWuhanHubei 430062China

Comprehensive Summary The conversion of CF3-alkenes to gem-difluoroalkenes using reductive cross-coupling strategy has received much attention in recent years,however,the use of green and readily available reducing salt to mediate these reactions remains to be *** this work,a concise construction of gem-difluoroalkenes,which requires neither a catalyst nor a metal reducing agent,was ***,a safe and inexpensive industrial product,was employed as both a radical initiator and *** procedure was compatible with both linear and cyclic diaryliodonium salts,enabling a wide variety of substrates(>70 examples).The utility of this approach was demonstrated through gram-scale synthesis and efficient late-stage functionalizations of anti-inflammatory drugs.

关键词： Defluoroarylation Transition metal free gem-Difluoroalkenes Rongalite Single electron transfer C-C coupling Redox reactions Cross-coupling

NFT Security Matrix:Towards Modeling NFT Ecosystem Threat

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

Computer Modeling in Engineering & Sciences 2024年第6期139卷 3255-3285页

作者： Peng Liao Chaoge Liu Jie Yin zhi Wang xiang Cui Key Laboratory of Trustworthy Distributed Computing and Service Beijing University of Posts and TelecommunicationsBeijing100876China Zhongguancun Laboratory Beijing100094China Institute of Information Engineering Chinese Academy of SciencesBeijing100085China

Digital assets have boomed over the past few years with the emergence of Non-fungible Tokens(NFTs).To be specific,the total trading volume of digital assets reached an astounding$55.5 billion in ***,numerous security concerns have been raised by the rapid expansion of the NFT *** holders are exposed to a plethora of scams and traps,putting their digital assets at risk of being ***,academic research on NFT security is scarce,and the security issues have aroused rare *** this study,the NFT ecological process is comprehensively *** process falls into five different stages encompassing the entire lifecycle of ***,the security issues regarding the respective stage are elaborated and analyzed in depth.A matrix model is proposed as a novel contribution to the categorization of NFT security *** data are collected from social networks,the Ethereum blockchain,and NFT markets to substantiate our claims regarding the severity of security concerns in the NFT *** this comprehensive dataset,nine key NFT security issues are identified from the matrix model and then subjected to qualitative and quantitative *** study aims to shed light on the severity of NFT ecosystem security *** findings stress the need for increased attention and proactive measures to safeguard the NFT ecosystem.

关键词： Non-fungible token blockchain cyber security

A lithium–tin fluoride anode enabled by ionic/electronic conductive paths for garnet-based solid-state lithium metal batteries

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

Rare Metals 2024年第2期43卷 575-587页

作者： Lei Zhang Qian-Kun Meng xiang-Ping Feng Ming Shen yu-Qing Zhang Quan-Chao Zhuang Run-Guo Zheng zhi-yuan Wang Yan-Hua Cui Hong-yu Sun Yan-Guo Liu School of Materials Science and Engineering Northeastern UniversityShenyang110819China School of Resources and Materials Northeastern University at QinhuangdaoQinhuangdao066004China School of Materials and Physics China University of Mining&TechnologyXuzhou221116China Institute of Electronic Engineering China Academy of Engineering PhysicsMianyang621900China

The high energy density and stability of solid-state lithium metal batteries(SSLMBs)have garnered great ***-type oxides,especially Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO),with high ionic conductivity,wide electrochemical window,and stability to Li metal anode,are promising solid-state electrolyte(SSEs)materials for ***,Li/LLZTO interface issues including high interface resistance,inhomogeneous Li deposition,and Li dendrite growth have hindered the practical application of ***,a multi-functional Li–SnF_(2) composite anode with Li,LiF,and Li-Sn alloy was specifically designed and *** composite anode improves the wettability to LLZTO,constructing an intimate contact interface between it and ***,ionic/electronic conductive paths in situ formed at the interface can effectively uniform Li deposition and suppress Li *** solid-state symmetric cell exhibits low interface resistance(11Ω·cm^(2)) and high critical current density(1.3 mA·cm^(−2))at 25℃.The full SSLMB based on LiFePO_(4) or LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2) cathode also shows stable cycling performance and high rate *** work provides a new composite anode strategy for achieving high-energy density and high-safety SSLMBs.

关键词： Solid-state lithium metal batteries(SSLMBs) Lithium-tin fluoride anode Ionic/electronic conductive Interface resistance Lithium dendrite