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Recyclable hydrolyzed polymers of intrinsic microporosity-1/Fe_(3)O_(4) magnetic composites as adsorbents for selective cationic dye adsorption

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Frontiers of Chemical Science and Engineering 2024年第2期18卷 113-125页

作者： Feng Zhang Shuainan Xu Xiumei Geng Meixia shan Yatao Zhang School of Chemical Engineering Zhengzhou UniversityZhengzhou 450001China

Polymers of intrinsic microporosity shows great potential for dye adsorption and magnetic Fe_(3)O_(4) are easy to be *** this work,hydrolyzed polymers of intrinsic microporosity-1/Fe_(3)O_(4) composite adsorbents were prepared by phase inversion and hydrolysis process for cationic dye *** chemical structure and morphology of the composite adsorbents were systematically characterized by several characterization *** methylene blue as the target dye,the influences of solution pH,contact time,initial dye concentration,and system temperature on the methylene blue adsorption process were *** incorporation of Fe_(3)O_(4) particle into hydrolyzed polymers of intrinsic microporosity-1 endow the adsorbent with high magnetic saturation(20.7 emu·g^(–1))which allows the rapid separation of the ***,the adsorption process was simulated by adsorption kinetics,isotherms and thermodynamics to gain insight onto the intrinsic adsorption *** addition,the composite adsorbents are able to selectively adsorb cationic dyes from mixed dyes *** polymers of intrinsic microporosity/Fe_(3)O_(4) shows only a slight decrease for methylene blue adsorption after 10 adsorption/regeneration cycles,demonstrating the outstanding regeneration *** high adsorption capacity,outstanding regeneration ability,together with simple preparation method,endow the composite adsorbents great potential for selective removal of cationic dyes in wastewater system.

关键词： polymers of intrinsic microporosity magnetic adsorbent cationic dye adsorption

Recent research progress in the mechanism and suppression of fusion welding-induced liquation cracking of nickel based superalloys

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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 1072-1088页

作者： Zongli Yi Jiguo shan Yue Zhao Zhenlin Zhang Aiping Wu Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China College of Engineering China Agricultural UniversityBeijing 100091China State Key Laboratory of Clean and Efficient Turbomachinery Power Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing 100084China School of Material Science and Engineering Southwest Jiaotong UniversityChengdu 610031China

Nickel-based superalloys are extensively used in the crucial hot-section components of industrial gas turbines,aeronautics,and astronautics because of their excellent mechanical properties and corrosion resistance at high *** welding serves as an effective means for joining and repairing these alloys;however,fusion welding-induced liquation cracking has been a challenging *** paper comprehensively reviewed recent liquation cracking,discussing the formation mechanisms,cracking criteria,and *** recent investigations,regulating material composition,changing the preweld heat treatment of the base metal,optimizing the welding process parameters,and applying auxiliary control methods are effective strategies for mitigating *** promote the application of nickel-based superalloys,further research on the combination impact of multiple elements on cracking prevention and specific quantitative criteria for liquation cracking is necessary.

关键词： nickel-based superalloy fusion welding liquation cracking cracking mechanism cracking suppression

Uncertainty and disturbance estimator-based model predictive control for wet flue gas desulphurization system

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Chinese Journal of Chemical Engineering 2024年第3期67卷 182-194页

作者： shan Liu Wenqi Zhong Li Sun Xi Chen Rafal Madonski School of Energy and Environment Key Laboratory of Energy Thermal Conversion and Control of Ministry of EducationSoutheast UniversityNanjing 210096China Faculty of Automatic Control Electronics and Computer ScienceSilesian University of TechnologyGliwise 44-100Poland

Wet flue gas desulphurization technology is widely used in the industrial process for its capability of efficient pollution *** desulphurization control system,however,is subjected to complex reaction mechanisms and severe disturbances,which make for it difficult to achieve certain practically relevant control goals including emission and economic performances as well as system *** address these challenges,a new robust control scheme based on uncertainty and disturbance estimator(UDE)and model predictive control(MPC)is proposed in this *** UDE is used to estimate and dynamically compensate acting disturbances,whereas MPC is deployed for optimal feedback regulation of the resultant *** viewing the system nonlinearities and unknown dynamics as disturbances,the proposed control framework allows to locally treat the considered nonlinear plant as a linear *** obtained simulation results confirm that the utilization of UDE makes the tracking error negligibly small,even in the presence of unmodeled *** the conducted comparison study,the introduced control scheme outperforms both the standard MPC and PID(proportional-integral-derivative)control strategies in terms of transient performance and ***,the results reveal that a lowpass-filter time constant has a significant effect on the robustness and the convergence range of the tracking error.

关键词： Desulphurization system Disturbance rejection Model predictive control Uncertainty and disturbance estimator Nonlinear system

Influence of Incomplete Soil Plugs on Bearing Capacities of Bucket Foundations in Clay

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China Ocean Engineering 2024年第1期38卷 144-155页

作者： LI Hui-shan LIU Run YANG Xu LIAN Ji-jian State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation Tianjin UniversityTianjin 300072China School of Civil Engineering Tianjin UniversityTianjin 300072China Institute of Marine Energy and Intelligent Construction Tianjin University of TechnologyTianjin 300384China

Due to the uneven seabed and heaving of soil during pumping,incomplete soil plugs may occur during the installation of bucket foundations,and the impacts on the bearing capacities of bucket foundations need to be *** this paper,the contact ratio(the ratio of the top diameter of the soil plug to the diameter of the bucket)and the soil plug ratio(the ratio of the soil heave height to the skirt height)are defined to describe the shape and size of the incomplete soil ***,finite element models are established to investigate the bearing capacities of bucket foundations with incomplete soil plugs and the influences of the contact ratios,and the soil plug ratios on the bearing capacities are *** results show that the vertical bearing capacity of bucket foundations in homogeneous soil continuously improves with the increase of the contact ***,in normally consolidated soil,the vertical bearing capacity barely changes when the contact ratio is smaller than 0.75,while the bearing capacity suddenly increases when the contact ratio increases to 1 due to the change of failure *** contact ratio hardly affects the horizontal bearing capacity of bucket ***,the moment bearing capacity improves with the increase of the contact ratio for small aspect ratios,but hardly varies with increasing contact ratio for aspect ratios larger than ***,the reduction coefficient method is proposed based on this analysis to calculate the bearing capacities of bucket foundations considering the influence of incomplete soil *** comparison results show that the proposed reduction coefficient method can be used to evaluate the influences of incomplete soil plug on the bearing capacities of bucket foundations.

关键词： bucket foundation incomplete soil plug uniaxial bearing capacity contact ratio soil plug ratio

Disturbances rejection optimization based on improved two-degree-of-freedom LADRC for permanent magnet synchronous motor systems

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Defence Technology（防务技术） 2024年第3期33卷 518-531页

作者： Chenggang Wang Jianhu Yan Wenlong Li Liang shan Le Sun School of Automation Nanjing University of Science and TechnologyNanjing 210094China

Permanent magnet synchronous motor(PMSM)speed control systems with conventional linear active disturbance rejection control(CLADRC)strategy encounter issues regarding the coupling between dynamic response and disturbance suppression and have poor performance in suppressing complex nonlinear *** order to address these issues,this paper proposes an improved two-degree-of-freedom LADRC(TDOF-LADRC)strategy,which can enhance the disturbance rejection performance of the system while decoupling entirely the system's dynamic and anti-disturbance performance to boost the system robustness and simplify controller parameter *** models that consider total disturbances are developed to design the TDOF-LADRC speed controller ***,to evaluate the control performance of the TDOF-LADRC strategy,its stability is proven,and the influence of each controller parameter on the system control performance is *** on it,a comparison is made between the disturbance observation ability and anti-disturbance performance of TDOF-LADRC and CLADRC to prove the superiority of TDOF-LADRC in rejecting ***,experiments are performed on a 750 W PMSM experimental platform,and the results demonstrate that the proposed TDOF-LADRC exhibits the properties of two degrees of freedom and improves the disturbance rejection performance of the PMSM system.

关键词： Permanent magnet synchronous motor(PMSM) Active disturbance rejection control(ADRC) Disturbance observer Two-degree-of-freedom control Anti-disturbance

Spherical Confinement Generates Entropic Force to Accelerate Polymer Chain Detachment

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Chinese Journal of Polymer Science 2024年第3期42卷 407-416,I0010页

作者： Yu-shan Zheng Jian-Ping Zhou Yan Xu Kai Li Mechanical Engineering Xinjiang UniversityUrumqi 830002China

To understand the dynamic process of polymer detachment, it is necessary to determine the mean detachment time of a single breakable link, which is modeled as a spring. Normally, this time can be viewed as the escape of a Brownian particle from the potential well of the spring. However, as the free dangling length of the polymer chain increases, the conformational entropy of the chain is affected by geometric confinement. It means that the wall exerts a repulsive force on the chain, resulting in accelerated link detachment from a macroscopic perspective. In this work, we investigate the effect of entropy on the detachment rate in the case where the substrate is spherical. We demonstrate that spherical confinement accelerates chain detachment both inside and outside the sphere. An analytical expression for the mean detachment time of breakable links is given, which includes an additional pre-factor that is related to the partition function. Additionally, we analyze the expressions for entropic forces inside the sphere, outside the sphere, and on a flat wall, comparing their magnitudes to explain the difference in mean detachment time.

关键词： Polymer detachment Breakable link Entropic force Mean first passage time

Herbivore and native plant diversity synergistically resist alien plant invasion regardless of nutrient conditions

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Plant Diversity 2024年第5期46卷 640-647页

作者： Liping shan Meng Hou Key Laboratory of Wetland Ecology and Environment State Key Laboratory of Black Soils Conservation and UtilizationNortheast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102China

Alien plant invasion success can be inhibited by two key biotic factors:native herbivores and plant ***,few studies have experimentally tested whether these factors interact to synergistically resist invasion success,especially factoring in changing global environments(*** enrichment).Here we tested how the synergy between native herbivores and plant diversity affects alien plant invasion success in various nutrient *** this purpose,we exposed alien plant species in potmesocosms to different levels of native plant diversity(4 vs.8 species),native generalist herbivores,and high and low soil nutrient *** found that generalist herbivores preferred alien plants to native plants,inhibiting invasion success in a native *** inhibition was amplified by highly diverse native ***,the amplified effect between herbivory and native plant diversity was independent of nutrient *** results suggest that a higher diversity of native communities can strengthen the resistance of native generalist herbivores to alien plant invasions by enhancing herbivory *** synergistic effect remains in force in nutrient-enriched habitats that are always invaded by alien plant *** results shed light on the effective control of plant invasions using multi-trophic means,even in the face of future global changes.

关键词： Biological invasion Biotic resistance Diversity conservation Plant-herbivore interactions Resource availability Global change

Prompt learning in computer vision: a survey

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Frontiers of Information Technology & Electronic Engineering 2024年第1期25卷 42-63页

作者： Yiming LEI Jingqi LI Zilong LI Yuan CAO Hongming shan shanghai Key Laboratory of Intelligent Information Processing School of Computer ScienceFudan UniversityShanghai 200438China Institute of Science and Technology for Brain-Inspired Intelligence Fudan UniversityShanghai 200433China MOE Frontiers Center for Brain Science Fudan UniversityShanghai 200433China shanghai Center for Brain Science and Brain-Inspired Technology Shanghai 201210China

Prompt learning has attracted broad attention in computer vision since the large pre-trained visionlanguagemodels (VLMs) exploded. Based on the close relationship between vision and language information builtby VLM, prompt learning becomes a crucial technique in many important applications such as artificial intelligencegenerated content (AIGC). In this survey, we provide a progressive and comprehensive review of visual promptlearning as related to AIGC. We begin by introducing VLM, the foundation of visual prompt learning. Then, wereview the vision prompt learning methods and prompt-guided generative models, and discuss how to improve theefficiency of adapting AIGC models to specific downstream tasks. Finally, we provide some promising researchdirections concerning prompt learning.

关键词： Prompt learning Visual prompt tuning(VPT) Image generation Image classification Artificial intelligence generated content(AIGC)

Design and verification of an FPGA programmable logic element based on Sense-Switch pFLASH

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Frontiers of Information Technology & Electronic Engineering 2024年第4期25卷 485-499页

作者： Zhengzhou CAO Guozhu LIU Yanfei ZHANG Yueer shan Yuting XU No.58 Research Institute China Electronics Technology Group CorporationWuxi 214035China

This paper proposes a kind of programmable logic element(PLE)based on Sense-Switch pFLASH *** programming Sense-Switch pFLASH,all three-bit look-up table(LUT3)functions,partial four-bit look-up table(LUT4)functions,latch functions,and d flip flop(DFF)with enable and reset functions can be *** PLE uses a choice of operational logic(COOL)approach for the operation of logic functions,it allows any logic circuit to be implemented at any ratio of combinatorial logic to *** intrinsic property makes it close to the basic application specific integrated circuit(ASIC)cell in terms of fine granularity,thus allowing ASIC-like cell-based mappers to apply all their optimization *** measuring Sense-Switch pFLASH and PLE circuits,the results show that the“on”state driving current of the Sense-Switch pFLASH is about 245.52μA,and that the“off”state leakage current is about 0.1 *** programmable function of PLE works *** delay of the typical combinatorial logic operation AND3 is 0.69 ns,and the delay of the sequential logic operation DFF is 0.65 ns,both of which meet the requirements of the design technical index.

关键词： Field programmable gate array(FPGA) Programmable logic element(PLE) Boolean logic operation Look-up table Sense-Switch pFLASH Threshold voltage