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Chinese Chemical Letters 2014年第5期25卷 752-756页

作者： qing-Yun Liu qing-Yan jia ji-qin zhu Qian Shao Jun-Feng Fan Dong-Mei Wang Yan-Sheng Yin College of Chemistry and Chemical Engineering Ocean University of China College of Chemical and Environmental Engineering Shandong University of Science and Technology Institute of Marine Materials Science and Engineering Shanghai Maritime University

meso-Tetrakis（4-aminophenyl）porphyrin（TAPP） can self-assemble into nanostructures with different morphologies by a phase-transfer *** morphologies（nanospheres,nanorods and nanothorns）of porphyrin nanoaggregates could be easily tuned just by changing the concentration of porphyrin in a proper solvent at room *** images revealed the formation of highly ordered supramolecular arrays of TAPP,i.e. superlattice of TAPP molecules in nanoaggregates,which agreed well with the size of one molecule of ***–vis absorption spectra showed an obvious red shift of the Soret band of TAPP,indicating the formation of J-aggregates of TAPP in nanoaggregates.

关键词： Porphyrin Self-assembly Nanoaggregates Highly ordered Hydrogen bonding

Data-driven casting defect prediction model for sand casting based on random forest classification algorithm

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China Foundry 2024年第2期21卷 137-146页

作者： Bang Guan Dong-hong Wang Da Shu Shou-qin zhu Xiao-yuan ji Bao-de Sun Shanghai Key Lab of Advanced High-Temperature Materials and Precision Forming School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Lab of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240China Hefei Casting and Forging Factory of Anhui Heli Co. LtdHefei 230000China State Key Laboratory of Materials Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan 430074China

The complex sand-casting process combined with the interactions between process parameters makes it difficult to control the casting quality,resulting in a high scrap rate.A strategy based on a data-driven model was proposed to reduce casting defects and improve production efficiency,which includes the random forest(RF)classification model,the feature importance analysis,and the process parameters optimization with Monte Carlo *** collected data includes four types of defects and corresponding process parameters were used to construct the RF *** results show a recall rate above 90% for all *** Gini Index was used to assess the importance of the process parameters in the formation of various defects in the RF ***,the classification model was applied to different production conditions for quality *** the case of process parameters optimization for gas porosity defects,this model serves as an experimental process in the Monte Carlo method to estimate a better temperature *** prediction model,when applied to the factory,greatly improved the efficiency of defect *** show that the scrap rate decreased from 10.16% to 6.68%.

关键词： sand casting process data-driven method classification model quality prediction feature importance

A Tri-mode of Mock-Walker Cells

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Advances in Atmospheric Sciences 2024年第4期41卷 671-679页

作者： Han qin ji NIE Zhiyong MENG Laboratory for Climate and Ocean-Atmosphere Studies Department of Atmospheric and Oceanic SciencesSchool of PhysicsPeking UniversityBeijing 100871China China Meteorological Administration Tornado Key Laboratory Foshan 528061China

This work uses cloud-resolving simulations to study mock-Walker cells driven by a specified sea surface temperature(SST).The associated precipitation in the mock-Walker cells exhibits three different modes,including a single peak of precipitation over the SST maximum(mode 1),symmetric double peaks of precipitation straddling the SST maximum(mode 2),and a single peak of precipitation on one side of the SST maximum(mode 3).The three modes are caused by three distinct convective activity center migration *** indicate that the virtual effect of water vapor plays an important role in differentiating the three *** the SST gradient is large,the virtual effect may be strong enough to overcome the temperature effect,generating a low-level low-pressure anomaly below the ascending branch of the Walker cell off the *** results here highlight the importance of the virtual effect of water vapor and its interaction with convection and large-scale circulation in the Walker circulation.

关键词： Walker circulation cloud-resolving simulation virtual effect

Role of catalyst surface-active sites in the hydrogenation ofα,β-unsaturated aldehyde

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Frontiers of Chemical Science and Engineering 2024年第6期18卷 41-69页

作者： Haixiang Shi Tongming Su Zuzeng qin Hongbing ji School of Chemistry and Chemical Engineering Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification TechnologyGuangxi UniversityNanning 530004China Zhejiang Green Petrochemical and Light Hydrocarbon Transformation Research Institute Zhejiang University of TechnologyHangzhou 310014China

As an important technology in fine chemical production,the selective hydrogenation ofα,β-unsaturated aldehydes has attracted much attention in recent *** the process ofα,β-unsaturated aldehyde hydrogenation,a conjugated system is formed between>C=CC=O,leading to hydrogenation at both ends of the conjugated system,which competes with each other and results in more complex ***,improving the reaction selectivity is also difficult in industrial ***,many researchers have reported that surface-active sites on catalysts play a crucial role inα,β-unsaturated aldehyde *** review attempts to summarize recent advances in understanding the effects of surface-active sites(SASs)over metal catalysts for enhancing the process of *** construction strategies and roles of SASs for hydrogenation catalysts are *** attention has been given to the adsorption configuration and transformation mechanism ofα,β-unsaturated aldehydes on catalysts,which contributes to understanding the relationship between SASs and hydrogenation *** addition,recent advances in metal-supported catalysts for the selective hydrogenation ofα,β-unsaturated aldehydes to understand the role of SASs in hydrogenation are briefly ***,the opportunities and challenges will be highlighted for the future development of the precise construction of SASs.

关键词： α,β-unsaturatedd aldehydes hydrogenation active site cinnamaldehyde

Gas–solid reactor optimization based on EMMS-DPM simulation and machine learning

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Particuology 2024年第6期89卷 131-143页

作者： Haolei Zhang Aiqi zhu ji Xu Wei Ge State Key Laboratory of Mesoscience and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Innovation Academy for Green Manufacture Chinese Academy of SciencesBeijing 100190China

Design,scaling-up,and optimization of industrial reactors mainly depend on step-by-step experiments and engineering experience,which is usually time-consuming,high cost,and high *** numerical simulation can reproduce high resolution details of hydrodynamics,thermal transfer,and reaction process in reactors,it is still challenging for industrial reactors due to huge computational *** this study,by combining the numerical simulation and artificial intelligence(AI)technology of machine learning(ML),a method is proposed to efficiently predict and optimize the performance of industrial reactors.A gas–solid fluidization reactor for the methanol to olefins process is taken as an example.1500 cases under different conditions are simulated by the coarse-grain discrete particle method based on the Energy-Minimization Multi-Scale model,and thus,the reactor performance data set is *** develop an efficient reactor performance prediction model influenced by multiple factors,the ML method is established including the ensemble learning strategy and automatic hyperparameter optimization technique,which has better performance than the methods based on the artificial neural ***,the operating conditions for highest yield of ethylene and propylene or lowest pressure drop are searched with the particle swarm optimization algorithm due to its strength to solve non-linear optimization *** show that decreasing the methanol inflow rate and increasing the catalyst inventory can maximize the yield,while decreasing methanol the inflow rate and reducing the catalyst inventory can minimize the pressure *** two objectives are thus conflicting,and the practical operations need to be compromised under different circumstance.

关键词： Discrete particle method Artificial intelligence Machine learning Particle swarm optimization Industrial reactor optimization

Electrically-driven ultrafast out-of-equilibrium light emission from hot electrons in suspended graphene/hBN heterostructures

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International Journal of Extreme Manufacturing 2024年第1期6卷 328-338页

作者： Qiang Liu Wei Xu Xiaoxi Li Tongyao Zhang Chengbing qin Fang Luo Zhihong zhu Shiqiao qin Mengjian zhu Kostya S Novoselov College of Advanced Interdisciplinary Studies&Hunan Provincial Key Laboratory of Novel Nano-optoelectronic Information Materials and Devices National University of Defense TechnologyChangshaHunan 410073People’s Republic of China Nanhu Laser Laboratory National University of Defense TechnologyChangshaHunan 410073People’s Republic of China State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-ElectronicsShanxi UniversityTaiyuan 030006People’s Republic of China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006People’s Republic of China State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser SpectroscopyShanxi UniversityTaiyuan 030006People’s Republic of China Institute for Functional Intelligent Materials National University of SingaporeSingapore 117544Singapore Department of Materials Science and Engineering National University of SingaporeSingapore 117575Singapore

Nanoscale light sources with high speed of electrical modulation and low energy consumption are key components for nanophotonics and *** record-high carrier mobility and ultrafast carrier dynamics of graphene make it promising as an atomically thin light emitter which can be further integrated into arbitrary platforms by van der Waals ***,due to the zero bandgap,graphene is difficult to emit light through the interband recombination of carriers like conventional ***,we demonstrate ultrafast thermal light emitters based on suspended graphene/hexagonal boron nitride(Gr/hBN)*** in biased graphene are significantly heated up to 2800 K at modest electric fields,emitting bright photons from the near-infrared to the visible spectral *** eliminating the heat dissipation channel of the substrate,the radiation efficiency of the suspended Gr/hBN device is about two orders of magnitude greater than that of graphene devices supported on SiO2or *** demonstrate that hot electrons and low-energy acoustic phonons in graphene are weakly coupled to each other and are not in full thermal *** cooling ofhigh-temperature hot electrons to low-temperature acoustic phonons is enabled by the significant near-field heat transfer at the highly localized Gr/hBN interface,resulting in ultrafast thermal emission with up to 1 GHz bandwidth under electrical *** is found thatsuspending the Gr/hBN heterostructures on the SiO2trenches significantly modifies the light emission due to the formation of the optical cavity and showed a~440%enhancement inintensity at the peak wavelength of 940 nm compared to the black-body thermal *** demonstration of electrically driven ultrafast light emission from suspended Gr/hBNheterostructures sheds the light on applications of graphene heterostructures in photonicintegrated circuits,such as broadband light sources and ultrafast thermo-optic phase modulat

关键词： suspended graphene ultrafast light emitter van der Waals heterostructures thermal radiation electron–phonon interaction

Precise region semantics-assisted GAN for pose-guided person image generation

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CAAI Transactions on Intelligence Technology 2024年第3期9卷 665-678页

作者： ji Liu Zhenyu Weng Yuesheng zhu Communication and Information Security Lab Shenzhen Graduate SchoolPeking UniversityShenzhenChina School of Electrical and Electronic Engineering Nanyang Technological UniversitySingaporeSingapore

Generating a realistic person's image from one source pose conditioned on another different target pose is a promising computer vision *** previous mainstream methods mainly focus on exploring the transformation relationship between the keypoint-based source pose and the target pose,but rarely investigate the region-based human semantic *** current methods that adopt the parsing map neither consider the precise local pose-semantic matching issues nor the correspondence between two different *** this study,a Region Semantics-Assisted Generative Adversarial Network(RSA-GAN)is proposed for the pose-guided person image gen-eration *** particular,a regional pose-guided semantic fusion module is first devel-oped to solve the imprecise match issue between the semantic parsing map from a certain source image and the corresponding keypoints in the source *** well align the style of the human in the source image with the target pose,a pose correspondence guided style injection module is designed to learn the correspondence between the source pose and the target *** addition,one gated depth-wise convolutional cross-attention based style integration module is proposed to distribute the well-aligned coarse style information together with the precisely matched pose-guided semantic information to-wards the target *** experimental results indicate that the proposed RSA-GAN achieves a 23%reduction in LPIPS compared to the method without using the seman-tic maps and a 6.9%reduction in FID for the method with semantic maps,respectively,and also shows higher realistic qualitative results.

关键词： deep learning image processing

DEGREE ELEVATION AND KNOT INSERTION FOR GENERALIZED BEZIER SURFACES AND THEIR´APPLICATION TO ISOGEOMETRIC ANALYSIS

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Journal of Computational Mathematics 2024年第5期42卷 1197-1225页

作者： Mengyun Wang Ye ji Chungang zhu School of Mathematical Sciences Dalian University of TechnologyDalian 116024China Key Laboratory for Computational Mathematics and Data Intelligence of Liaoning Province Dalian 116024China

Generalized B´ezier surfaces are a multi-sided generalization of classical tensor product B´ezier surfaces with a simple control structure and inherit most of the appealing properties from B´ezier ***,the original degree elevation changes the geometry of generalized B´ezier surfaces such that it is undesirable in many applications,*** *** this paper,we propose an improved degree elevation algorithm for generalized B´ezier surfaces preserving not only geometric consistency but also parametric *** on the knot insertion of B-splines,a novel knot insertion algorithm for generalized B´ezier surfaces is also *** the proposed algorithms are employed to increase degrees of freedom for multi-sided computational domains parameterized by generalized B´ezier surfaces in isogeometric analysis,corresponding to the traditional p-,h-,and *** examples demonstrate the effectiveness and superiority of our method.

关键词： Generalized B´ezier surface Degree elevation Knot insertion Isogeometric analysis Refinement

Transitional Revenue Scheme for High-cost Generator Unit in Guangdong Electricity Market Based on Government Authorized Contracts

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 208-221页

作者： jisong zhu Baike Chen Tianyao ji Zhaoxia jing School of Electric Power Engineering South China University of TechnologyGuangzhou 510640China

High-cost generator units are at a cost disadvantage in electricity spot *** study focuses on revenue mechanisms of gas-fired units affected by power market reform in Guangdong province,*** the first time,we compare impacts on market indicators of five settlement mechanisms:feed-in tariff(FiT),location marginal price(LMP),contract for difference(CFD),direct subsidy(DS),and estimated revenue method(ERM).In particular,we design key parameters,including authorized CFD and ERM of two kinds of government authorized contracts based on traditional dispatching patterns to avoid significant profit fluctuations brought by market *** also analyze impact of factors such as climbing performance,seasonal load,and subsidy amount on the overall market and its *** of a case study show to directly subsidize gasfired units will lead higher-cost units to generate more electricity,with a resulting loss of social *** of market prices and provision of unreasonable incentives are fatal disadvantages of this subsidy *** government and policymakers should consider financial means to adjust benefits to reduce production costs and increase social ***,by case analysis,the ERM shows its stable performance in revenue of high-cost units,while we find that authorized CFD is not applicable for gas-fired units whose output is unstable as a marginal unit ***,we suggest government agencies adopt ERM to sign contracts with gas-fired units,to attain a balance between fairness and efficiency.

关键词： Guangdong electricity market high-cost generator unit settlement mechanism subsidy

Dynamic compliance of energy-saving legged elastic parallel joints for quadruped robots:design and realization

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Frontiers of Mechanical Engineering 2024年第2期19卷 45-58页

作者： Yaguang zhu Minghuan ZHANG Xiaoyu ZHANG Haipeng qin Key Laboratory of Road Construction Technology and Equipment of Ministry of Education School of Engineering MachineryChang’an UniversityXi’an 710064China State Key Laboratory of Robotics and Systems Harbin Institute of TechnologyHarbin 150001China

Achieving dynamic compliance for energy-efficient legged robot motion is a longstanding *** recent predictive control methods based on single-rigid-body models can generate dynamic motion,they all assume infinite energy,making them unsuitable for prolonged robot *** this issue necessitates a mechanical structure with energy storage and a dynamic control strategy that incorporates feedback to ensure *** work draws inspiration from the efficiency of bio-inspired muscle–tendon networks and proposes a controllable torsion spring leg *** design integrates a spring-loaded inverted pendulum model and adopts feedback delays and yield springs to enhance the delay effects.A leg control model that incorporates motor loads is developed to validate the response and dynamic performance of a leg with elastic *** model provides torque to the knee joint,effectively reducing the robot’s energy consumption through active or passive control *** benefits of the proposed approach in agile maneuvering of quadruped robot legs in a realistic scenario are demonstrated to validate the dynamic motion performance of the leg with elastic joints with the advantage of energy-efficient legs.

关键词： dynamic responsiveness energy dissipation legged locomotion parallel joints quadruped robot