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3D printing for ultra-precision machining:current status,opportunities,and future perspectives

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Frontiers of Mechanical Engineering 2024年第4期19卷 1-28页

作者： Tao HE Wai Sze YIP Edward Hengzhou YAN Jiuxing TANG muhammad.rehan Long TENG Chi Ho WONG Linhe SUN Baolong ZHANG Feng GUO Shaohe ZHANG Suet TO State Key Laboratory of Ultra-precision Machining Technology Department of Industrial and Systems EngineeringThe Hong Kong Polytechnic UniversityHong KongChina Department of Industrial and Systems Engineering The Hong Kong Polytechnic UniversityHong KongChina Department of Physics The Hong Kong University of Science and TechnologyHong KongChina School of Geosciences and Info-Physics Central South UniversityChangsha 410083China

Additive manufacturing,particularly 3D printing,has revolutionized the manufacturing industry by allowing the production of complex and intricate parts at a lower cost and with greater ***,3D-printed parts frequently require post-processing or integration with other machining technologies to achieve the desired surface finish,accuracy,and mechanical ***-precision machining(UPM)is a potential machining technology that addresses these challenges by enabling high surface quality,accuracy,and repeatability in 3D-printed *** study provides an overview of the current state of UPM for 3D printing,including the current UPM and 3D printing stages,and the application of UPM to 3D *** the presentation of current stage perspectives,this study presents a detailed discussion of the benefits of combining UPM with 3D printing and the opportunities for leveraging UPM on 3D printing or supporting each *** particular,future opportunities focus on cutting tools manufactured via 3D printing for UPM,UPM of 3D-printed components for real-world applications,and post-machining of 3D-printed ***,future prospects for integrating the two advanced manufacturing technologies into potential industries are *** study concludes that UPM is a promising technology for 3D-printed components,exhibiting the potential to improve the functionality and performance of 3D-printed products in various *** also discusses how UPM and 3D printing can complement each other.

关键词： ultra-precision machining 3D printing additive manufacturing future perspectives start-of-the-art-review

Coordinated Robust PID-based Damping Control of Permanent Magnet Synchronous Generators for Low-frequency Oscillations Considering Power System Operational Uncertainties

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1042-1051页

作者： rehan Sadiq Zhen Wang Chi Yung Chung Deqiang Gan Cunzhi Tong College of Electrical Engineering Zhejiang UniversityHangzhou 310058China The Hong Kong Polytechnic University Hong KongChina State Grid Zhejiang Electric Power Company Hangzhou 310007China

In recent years, with the growth of wind energy resources,the capability of wind farms to damp low-frequency oscillations(LFOs) has provided a notable advantage for the stabilityenhancement of the modern power grid. Meanwhile, owingto variations in the power system operating point (OP), thedamping characteristics of LFOs may be affected adversely. Inthis respect, this paper presents a coordinated robust proportional-integral-derivative (PID) based damping control approachfor permanent magnet synchronous generators (PMSGs)to effectively stabilize LFOs, while considering power system operationaluncertainties in the form of a polytopic model constructedby linearizing the power system under a given set ofOPs. The proposed approach works by modulating the DC-linkvoltage control loop of the grid-side converter (GSC) via a supplementaryPID controller, which is synthesized by transformingthe design problem into H-infinity static output feedback(SOF) control methodology. The solution of H-infinity SOF controlproblem involves satisfying linear matrix inequality (LMI)constraints based on the parameter-dependent Lyapunov functionto ensure asymptotic stability such that the minimal H-infinityperformance objective is simultaneously accomplished forthe entire polytope. The coordinated damping controllers forthe multiple wind farms are then designed sequentially by usingthe proposed approach. Eigenvalue analysis confirms the improveddamping characteristics of the closed-loop system forseveral representative OPs. Afterward, the simulation results, includingthe performance comparison with existing approaches,validate the higher robustness of the proposed approach for awide range of operating scenarios.

关键词： Permanent magnet synchronous generator(PMSG) low-frequency oscillation(LFO) proportional-integralderivative(PID) robust control H-infinity static output feed-back control linear matrix inequality(LMI)

Defect Engineering in Earth-Abundant Cu_(2)ZnSnSe_(4) Absorber Using Efficient Alkali Doping for Flexible and Tandem Solar Cell Applications

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Energy & Environmental Materials 2024年第2期7卷 249-256页

作者： muhammad.rehan Ara Cho Inyoung Jeong Kihwan Kim Asmat Ullah Jun-Sik Cho Joo Hyung Park Yunae Jo Sung Jun Hong Seung Kyu Ahn SeJin Ahn Jae Ho Yun Jihye Gwak Donghyeop Shin Photovoltaics Research Department Korea Institute of Energy Research(KIER)152-Gajeong-roYuseong-guDaejeon 34129Korea Department of Renewable Energy Engineering University of Science and Technology(UST)217-Gajeong-roYuseong-guDaejeon 34113Korea Korea Institute of Energy Technology(KENTECH) 50772 Ujeong-roNaju Jeonnam 58217Korea

To demonstrate flexible and tandem device applications,a low-temperature Cu_(2)ZnSnSe_(4)(CZTSe)deposition process,combined with efficient alkali doping,was ***,high-quality CZTSe films were grown at 480℃by a single co-evaporation,which is applicable to polyimide(PI)*** of the alkali-free substrate,Na and K alkali doping were systematically studied and optimized to precisely control the alkali distribution in *** bulk defect density was significantly reduced by suppression of deep acceptor states after the(NaF+KF)*** the low-temperature deposition with(NaF+KF)PDTs,the CZTSe device on glass yields the best efficiency of 8.1%with an improved Voc deficit of 646 *** developed deposition technologies have been applied to *** the first time,we report the highest efficiency of 6.92%for flexible CZTSe solar cells on ***,CZTSe devices were utilized as bottom cells to fabricate four-terminal CZTSe/perovskite tandem cells because of a low bandgap of CZTSe(~1.0 eV)so that the tandem cell yielded an efficiency of 20%.The obtained results show that CZTSe solar cells prepared by a low-temperature process with in-situ alkali doping can be utilized for flexible thin-film solar cells as well as tandem device applications.

关键词： alkali doping Earth-abundant Cu_(2)ZnSnSe_(4) flexible solar cells four-terminal tandem cells low-temperature process

Design and Synthesis of NiO@Co_(3)O_(4)@ZSM-5 Heterogeneous Multitask Hollow Structures for Tandem Catalysis

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Chemical Research in Chinese Universities 2024年第3期40卷 529-535页

作者： muhammad Waqas Interdisciplinary Research Center for Refining and Advanced Chemicals King Fahd University of Petroleum&MineralsDhahran 31261Saudi Arabia

Precipitation and impregnation procedures unevenly distribute metals on zeolite,limiting chemical transformation in Lewis-acid,Brönsted-acid and metal-catalyzed tandem ***,heterogeneous multitask transition metals oxides@zeolites are promising catalysts for sustainable processes;nevertheless,synthesis is fascinating and ***,the construction of purposely designed multitask materials segregated in selective shells reveals the remarkable spatial organization of metals-zeolite,resulting in them being suitable for a wide range of tandem *** synthesis of multi-site catalysts begins with a universal wet chemistry approach that yields nickel oxide(NiO)***,the NiO crystals are stabilized using cationic dodecyltrimethylammonium bromide,followed by achieving cross-linking carbon growth by emulsion polymerization of glucose in hydrothermal treatment to yield uniformed NiO@carbon spheres(NiO@CSs).Next,sequential adsorption of cobalt cations and colloidal ZSM-5(1%in H_(2)O,mass fraction),followed by calcination in air,yielded NiO@cobalt oxide@zeolite denoted as NiO@Co_(3)O_(4)@ZEO hollow *** hollowing mechanism and materials segregation within shells are revealed by scanning and transmission electron microscopy,thermogravimetric analysis,and X-ray *** finding advances the rational synthesis of heterogenous core-shell hollow structures for various gas phase catalytic tandem reactions to yield valuable chemicals.

关键词： Multifunctional Core-shell hollow spheres Gas-phase reaction Valuable chemical

An integrated land change modeler and distributed hydrological model approach for quantifying future urban runoff dynamics

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Science China Earth Sciences 2024年第10期67卷 3288-3301页

作者： Asad Hussain muhammad Waseem muhammad Ajmal muhammad Atiq Ur Rehman Tariq muhammad Jiaqing XIAO Tao YANG Pengfei SHI Institute for Disaster Risk Management School of Geographical ScienceNanjing University of Information Science and TechnologyNanjing 210044China The National Key Laboratory of Water Disaster Prevention Hohai UniversityNanjing 210098China Yangtze Institute for Conservation and Development Hohai UniversityNanjing 210098China College of Hydrology and Water Resources Hohai UniversityNanjing 210098China Centre of Excellence in Water Resources Engineering University of Engineering and TechnologyLahore 54890Pakistan Department of Agricultural Engineering Faculty of CivilAgricultural and Mining EngineeringUniversity of Engineering and TechnologyPeshawar 25120Pakistan

Climate and land use changes have a significant impact on the runoff generation process in urban environments, and these effects could get worse in the future. The combined contributions of these changes have increased the risk of ***, there is a need for integrated modeling to better understand the runoff variability, especially in small urban catchments. To quantify and separate the effects of land-use changes and climate change on the hydrological response of urban catchments with a distributed hydrological model(Storm Water Management Model, SWMM), this study introduces a new integrated approach based on the Machine Learning based land use change modeler and climate change scenarios under *** on supervised classification and land use change model analysis, accumulated impervious area increase from 22%(in2023) to 33%(in 2060) was observed in the study area. Furthermore, integrating this projected increase in imperviousness with future climate change into SWMM by considering three different scenarios i.e., S1(Climate Change), S2(Combined Land Use and Climate Change), and S3(Land use Change) resulted that climate change could cause an increase in runoff from 13.2% to18.3% in peak runoff and the contribution of land use could range from 9.1% to 18.6%. Similarly, in response to the coupled effects of climate and land-use change, the runoff would likely change from 24.53% to 39.66%. Conclusively, the study showed that despite climate change, intensive urban development by the substitution of impervious surfaces could also have a severe impact on the microclimate and hydrology of small catchments. Lastly, this study could provide a way forward for the future planning and management of water resources in small catchments which could be extended to larger catchments.

关键词： Climate change Land-use modeling Runoff simulation Percent Imperviousness TerrSet

Sentiment Analysis of Low-Resource Language Literature Using Data Processing and Deep Learning

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Computers, Materials & Continua 2024年第4期79卷 713-733页

作者： Aizaz Ali Maqbool Khan Khalil Khan rehan Ullah Khan Abdulrahman Aloraini Department of IT and Computer Science Pak-Austria Fachhochschule:Institute of Applied Sciences and TechnologyHaripur22620Pakistan Software Competence Center Hagenberg Softwarepark 32aHagenberg4232Austria Department of Computer Science School of Engineering and Digital SciencesNazarbayev UniversityAstana010000Kazakhstan Department of Information Technology College of ComputerQassim UniversityP.O.Box 1162BuraydahSaudi Arabia

Sentiment analysis, a crucial task in discerning emotional tones within the text, plays a pivotal role in understandingpublic opinion and user sentiment across diverse *** numerous scholars conduct sentiment analysisin widely spoken languages such as English, Chinese, Arabic, Roman Arabic, and more, we come to grapplingwith resource-poor languages like Urdu literature which becomes a challenge. Urdu is a uniquely crafted language,characterized by a script that amalgamates elements from diverse languages, including Arabic, Parsi, Pashtu,Turkish, Punjabi, Saraiki, and more. As Urdu literature, characterized by distinct character sets and linguisticfeatures, presents an additional hurdle due to the lack of accessible datasets, rendering sentiment analysis aformidable undertaking. The limited availability of resources has fueled increased interest among researchers,prompting a deeper exploration into Urdu sentiment analysis. This research is dedicated to Urdu languagesentiment analysis, employing sophisticated deep learning models on an extensive dataset categorized into fivelabels: Positive, Negative, Neutral, Mixed, and Ambiguous. The primary objective is to discern sentiments andemotions within the Urdu language, despite the absence of well-curated datasets. To tackle this challenge, theinitial step involves the creation of a comprehensive Urdu dataset by aggregating data from various sources such asnewspapers, articles, and socialmedia comments. Subsequent to this data collection, a thorough process of cleaningand preprocessing is implemented to ensure the quality of the data. The study leverages two well-known deeplearningmodels, namely Convolutional Neural Networks (CNN) and Recurrent Neural Networks (RNN), for bothtraining and evaluating sentiment analysis performance. Additionally, the study explores hyperparameter tuning tooptimize the models’ efficacy. Evaluation metrics such as precision, recall, and the F1-score are employed to assessthe effectiv

关键词： Urdu sentiment analysis convolutional neural networks recurrent neural network deep learning natural language processing neural networks

Enhancing PDF Malware Detection through Logistic Model Trees

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Computers, Materials & Continua 2024年第3期78卷 3645-3663页

作者： muhammad Binsawad Department of Information Systems King Abdulaziz UniversityP.O.Box 80217Jeddah21589Saudi Arabia

Malware is an ever-present and dynamic threat to networks and computer systems in cybersecurity,and because of its complexity and evasiveness,it is challenging to identify using traditional signature-based detection *** study article discusses the growing danger to cybersecurity that malware hidden in PDF files poses,highlighting the shortcomings of conventional detection techniques and the difficulties presented by adversarial *** article presents a new method that improves PDF virus detection by using document analysis and a Logistic Model *** a dataset from the Canadian Institute for Cybersecurity,a comparative analysis is carried out with well-known machine learning models,such as Credal Decision Tree,Naïve Bayes,Average One Dependency Estimator,Locally Weighted Learning,and Stochastic Gradient *** traditional structural and JavaScript-centric PDF analysis,the research makes a substantial contribution to the area by boosting precision and resilience in malware *** use of Logistic Model Tree,a thorough feature selection approach,and increased focus on PDF file attributes all contribute to the efficiency of PDF virus *** paper emphasizes Logistic Model Tree’s critical role in tackling increasing cybersecurity threats and proposes a viable answer to practical issues in the *** results reveal that the Logistic Model Tree is superior,with improved accuracy of 97.46%when compared to benchmark models,demonstrating its usefulness in addressing the ever-changing threat landscape.

关键词： Malware detection PDF files logistic model tree feature selection cybersecurity

Progress in electrocatalytic nitrate reduction for green energy:Catalyst engineering,mechanisms,and techno-economic feasibility

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Journal of Energy Chemistry 2024年第8期95卷 380-406,I0009页

作者： Hafiz muhammad Adeel Sharif Hafiz muhammad Farooq Khan Sadeeq Ullah Yuwei Wang muhammad Ahmad Bo Yang Changping Li muhammad Bilal Asif Research Center for Eco-Environmental Engineering Dongguan University of TechnologyDongguan 523808GuangdongChina College of Chemistry and Engineering Shenzhen UniversityShenzhen 518060GuangdongChina FMH College of Medicine and Dentistry LahorePakistan School of Environment and Civil Engineering Research Center for Eco-Environment EngineeringDongguan University of TechnologyDongguan 523106GuangdongChina Advanced Membranes and Porous Materials Center(AMPMC) Physical Sciences and Engineering(PSE)King Abdullah University of Science and Technology(KAUST)Thuwal 23955Saudi Arabia

Ammonia(NH_(3))is an irreplaceable chemical that has been widely demanded to keep the sustainable development of modern ***,its industrial production consumes a huge amount of energy and releases extraordinary greenhouse gases(GHGs),leading to various environmental *** the green production of ammonia is a great challenge,which has been extensively pursued in the last *** this review,the most promising strategy,electrochemical nitrate reduction reaction(e-NO_(3)RR),is comprehensively investigated to give a complete understanding of its development and mechanism and provide guidance for future ***,owing to the complex reactions and limited selectivity,a comprehensive understanding of the mechanisms is crucial to further development and ***,NO_(3)^(-)RR is a promising strategy for simultaneous water treatment and NH_(3)production.A detailed overview of the recent progress in NO_(3)^(-)RR for NH_(3)production with nontransition and transition metal based electrocatalysts is *** addition,critical advanced techniques,future challenges,and prospects are discussed to guide future research on transition metal-based catalysts for commercial NH_(3)synthesis by NO_(3)^(-)reduction.

关键词： Nitrate reduction Electrolysis Pollution to solution Transition metal catalysts Ammonia synthesis Green energy

Consequences of Rényi entropy on the thermal geometries and Hawking evaporation of topological dyonic dilaton black hole

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Communications in Theoretical Physics 2024年第2期76卷 102-110页

作者： muhammad Yasir Xia Tiecheng muhammad Usman Shahid Chaudhary Department of Mathematics Shanghai University and Newtouch Center for Mathematics of Shanghai UniversityShanghai200444China Department of Natural Sciences and Humanities University of Engineering and Technology LahoreNew CampusPakistan

The thermodynamics of black holes(BHs)has had a profound impact on theoretical physics,providing insight into the nature of gravity,the quantum structure of spacetime and the fundamental laws governing the *** this study,we investigate thermal geometries and Hawking evaporation of the recently proposed topological dyonic dilaton BH in anti-de Sitter(Ad S)*** consider Rényi entropy and obtain the relations for pressure,heat capacity and Gibbs free energy and observe that the Rényi parameter and dilaton field play a vital role in the phase transition and stability of the ***,we use Weinhold,Ruppeiner and Hendi Panahiyah Eslam Momennia models to evaluate the scalar curvature of the BH and find out that the divergence points of the scalar curvature coincides with the zero of specific ***,using Stefan–Boltzmann law,we determine that the BH without a dilaton field evaporates far more quickly compared to the dilaton BH in Ad S space.

关键词： topological dyonic dilaton black hole phase transition thermal geometry Hawking evaporation