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Prediction of Endpoint Phosphorus Content of Molten Steel in BOF Using Weighted K-Means and GMDH Neural Network

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Journal of Iron and Steel Research International 2012年第1期19卷 11-16页

作者： WANG Hong-bing XU An-jun ai Li-xiang tian Nai-yuan School of Computer and Communication Engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory of Advanced Control of Iron and Steel Process of Ministry of Education Beijing 100083China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

The hybrid method composed of clustering and predicting stages is proposed to predict the endpoint phos- phorus content of molten steel in BOF （Basic Oxygen Furnace）. At the clustering stage, the weighted K-means is performed to generate some clusters with homogeneous data. The weights of factors influencing the target are calcu- lated using EWM （Entropy Weight Method）. At the predicting stage, one GMDH （Group Method of Data Handling） polynomial neural network is built for each cluster. And the predictive results from all the GMDH polynomial neural networks are integrated into a whole to be the result for the hybrid method. The hybrid method, GMDH polnomial neural network and BP neural network are employed for a comparison. The results show that the proposed hybrid method is effective in predicting the endpoint phosphorus content of molten steel in BOF. Furthermore, the hybrid method outperforms BP neural network and GMDH polynomial neural network.

关键词： basic oxygen furnace endpoint phosphorus content K-means neural network GMDH

Interacting plexcitons for designed ultrafast optical nonlinearity in a monolayer semiconductor

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Light(Science & Applications) 2022年第5期11卷 877-887页

作者： Yuxiang Tang Yanbin Zhang Qirui Liu Ke Wei xiang’ai Cheng Lei Shi tian Jiang College of Advanced Interdisciplinary Studies National University of Defense Technology410073 ChangshaChina Key Laboratory of Micro-and NanoPhotonic Structures(Ministry of Education) and State Key Laboratory of Surface PhysicsDepartment of PhysicsFudan University200433 ShanghaiChina State Key Laboratory of High Performance Computing College of ComputerNational University of Defense Technology410073 ChangshaChina Beijing Institute for Advanced Study National University of Defense Technology100000 BeijingChina

Searching for ideal materials with strong effective optical nonlinear responses is a long-term task enabling remarkable breakthroughs in contemporary quantum and nonlinear ***,hybridized light-matter quasiparticles,are an appealing candidate to realize such ***,we explore a class of peculiar polaritons,named plasmon–exciton polaritons(plexcitons),in a hybrid system composed of silver nanodisk arrays and monolayer tungsten-disulfide(WS2),which shows giant room-temperature nonlinearity due to their deep-subwavelength localized ***,comprehensive ultrafast pump–probe measurements reveal that plexciton nonlinearity is dominated by the saturation and higher-order excitation-induced dephasing interactions,rather than the well-known exchange interaction in traditional microcavity ***,we demonstrate this giant nonlinearity can be exploited to manipulate the ultrafast nonlinear absorption properties of the solid-state *** findings suggest that plexcitons are intrinsically strongly interacting,thereby pioneering new horizons for practical implementations such as energy-efficient ultrafast all-optical switching and information processing.

关键词： nonlinearity monolayer nonlinear

Attitude Tracking Control for Rigid Spacecraft with Arbitrary Convergence Time

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Journal of Systems Science & Complexity 2024年第6期37卷 2579-2594页

作者： XU Yu-tian WU ai-Guo Guangdong Provincial Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics Harbin Institute of Technology(Shenzhen)Shenzhen 518055China Key University Laboratory of Mechanism&Machine Theory and Intelligent Unmanned Systems of Guangdong Harbin Institute of Technology(Shenzhen)Shenzhen 518055China Department of Automation Harbin Institute of Technology(Shenzhen)Shenzhen 518055China HIT Wuhu Robot Technology Research Institute Wuhu 241060China

In this paper,attitude tracking control with arbitrary convergence time for rigid spacecraft is ***,a novel time-varying sliding function is proposed to achieve free-will arbitrary time convergence when the system states reside on the sliding *** such a sliding function,an attitude tracking controller is designed to guarantee that the states of the closed-loop system converge to the sliding surface within a predetermined time in the presence of external *** free-will arbitrary time convergences of the closed-loop system and sliding function are illustrated by numerical simulations.

关键词： Attitude tracking free-will arbitrary time stability rigid spacecraft sliding mode control

Color coded metadevices toward programmed terahertz switching

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Light(Science & Applications) 2024年第7期13卷 1383-1392页

作者： Weibao He xiang’ai Cheng Siyang Hu Ziheng Ren Zhongyi Yu Shun Wan Yuze Hu tian Jiang College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangshaChina. Nanhu Laser Laboratory National University of Defense TechnologyChangshaChina. Hunan Provincial Key Laboratory of High Energy Laser Technology National University of Defense TechnologyChangshaChina. Institute for Quantum Science and Technology College of ScienceNational University of Defense TechnologyChangshaChina

Terahertz modulators play a critical role in high-speed wireless communication,non-destructive imaging,and so on,which have attracted a large amount of research ***,all-optical terahertz modulation,an ultrafast dynamical control approach,remains to be limited in terms of encoding and *** we experimentally demonstrated an optical-programmed terahertz switching realized by combining optical metasurfaces with the terahertz metasurface,resulting in 2-bit dual-channel terahertz *** terahertz metasurface,made up of semiconductor islands and artificial microstructures,enables effective all-optical programming by providing multiple frequency channels with ultrafast modulation at the nanosecond ***,optical metasurfaces covered in terahertz metasurface alter the spatial light field distribution to obtain color *** to the time-domain coupled mode theory analysis,the energy dissipation modes in terahertz metasurface can be independently controlled by color excitation,which explains the principle of 2-bit encoding *** work establishes a platform for all-optical programmed terahertz metadevices and may further advance the application of composite metasurface in terahertz manipulation.

关键词： terahertz surface excitation

Adipose mesenchymal stem cell-derived extracellular vesicles reduce glutamate-induced excitotoxicity in the retina

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Neural Regeneration Research 2023年第10期18卷 2315-2320页

作者： tian-Qi Duan Zhao-Lin Gao ai-xiang Luo Dan Chen Jian-Bin Tong Ju-Fang Huang Department of Anatomy and Neurobiology School of Basic Medical SciencesCentral South UniversityChangshaHunan ProvinceChina Hunan Province Key Laboratory of Brain Homeostasis Third Xiangya HospitalCentral South UniversityChangshaHunan ProvinceChina

Adipose mesenchymal stem cells(ADSCs)have protective effects against glutamate-induced excitotoxicity,but ADSCs are limited in use for treatment of optic nerve *** have shown that the extracellular vesicles(EVs)secreted by ADSCs(ADSC-EVs)not only have the function of ADSCs,but also have unique advantages including non-immunogenicity,low probability of abnormal growth,and easy access to target *** the present study,we showed that intravitreal injection of ADSC-EVs substantially reduced glutamate-induced damage to retinal morphology and *** addition,R28 cell pretreatment with ADSC-EVs before injury inhibited glutamate-induced overload of intracellular calcium,downregulation ofα-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid receptor(AMPAR)subunit GluA2,and phosphorylation of GluA2 and protein kinase C alpha in vitro.A protein kinase C alpha agonist,12-O-tetradecanoylphorbol 13-acetate,inhibited the neuroprotective effects of ADSC-EVs on glutamate-induced R28 *** findings suggest that ADSCEVs ameliorate glutamate-induced excitotoxicity in the retina through inhibiting protein kinase C alpha activation.

关键词： adipose mesenchymal stem cells calcium overload electroretinography excitotoxicity extracellular vesicles GluA2 glutamate protein kinase C alpha R28 cells retina retinal ganglion cell

A defect recognition model for cross-section profile of hot-rolled strip based on deep learning

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Journal of Iron and Steel Research International 2023年第12期30卷 2436-2447页

作者： tian-lun Li Wen-quan Sun An-rui He Jian Shao Chao Liu ai-bin Zhang Yi Qiang xiang-hong Ma National Engineering Research Center for Advanced Rolling and Intelligent Manufacturing University of Science and Technology BeijingBeijing100083China Academy of Machinery Science and Technology Beijing100044China School of Engineering and Applied Science Aston UniversityBirminghamB47ETUK

The cross-section profile is a key signal for evaluating hot-rolled strip quality,and ignoring its defects can easily lead to a final *** characteristics of complex curve,significant irregular fluctuation and imperfect sample data make it a challenge of recognizing cross-section defects,and current industrial judgment methods rely excessively on human decision making.A novel stacked denoising autoencoders(SDAE)model optimized with support vector machine(SVM)theory was proposed for the recognition of cross-section ***,interpolation filtering and principal component analysis were employed to linearly reduce the data dimensionality of the profile ***,the deep learning algorithm SDAE was used layer by layer for greedy unsupervised feature learning,and its final layer of back-propagation neural network was replaced by SVM for supervised learning of the final features,and the final model SDAE_SVM was obtained by further optimizing the entire network parameters via error ***,the curve mirroring and combination stitching methods were used as data augmentation for the training set,which dealt with the problem of sample imbalance in the original data set,and the accuracy of cross-section defect prediction was further *** approach was applied in a 1780-mm hot rolling line of a steel mill to achieve the automatic diagnosis and classification of defects in cross-section profile of hot-rolled strip,which helps to reduce flatness quality concerns in downstream processes.

关键词： Hot-rolled strip cross section:Curve recognition Deep learning-Stacked denoising autoencoder Support vector machine Imperfect data

Saturated absorption of different layered Bi_2Se_3 films in the resonance zone

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Photonics Research 2018年第10期6卷 I0010-I0016页

作者： JUN ZHANG tian JIANG TONG ZHOU HAO OUYANG CHENXI ZHANG ZHENG XIN ZHENYU WANG xiang’ai CHENG College of Advanced Interdisciplinary Studies National University of Defense Technology State Key Laboratory of High Performance Computing National University of Defense Technology College of Computer National Institute of Defense Technology Innovation Academy of Military Sciences PLA China

Here, we used the micro P-scan method to investigate the saturated absorption(SA) of different layered Bi_2Se_3 continuous films. Through resonance excitation, first, we studied the influence of the second surface state(SS) on SA. The second SS resonance excitation(～2.07 e V) resulted in a free carrier cross section that was 4 orders of magnitude larger than usual. At the same time, we found that the fast relaxation process of the massless Dirac electrons is much shorter than that of electrons in bulk states. Moreover, the second SS excitation resonance reduced the saturation intensity. Second, we studied the effect of the thickness on the SA properties of *** results showed that the saturation intensity was positively correlated to the thickness, the same as the modulation depth, and the thicker the Bi_2Se_3 film was, the less the second SS would influence it. This work demonstrated that by using Bi_2Se_3 as a saturable absorber through changing the thickness or excitation wavelength, a controllable SA could be achieved.

关键词：薄膜饱和强度通讯技术发展现状

Transformation mechanism of nutrient elements in the process of biochar preparation for returning biochar to soil

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Chinese Journal of Chemical Engineering 2017年第4期25卷 477-486页

作者： Shuangshuang tian Zhongxin Tan Alfreda Kasiuliene Ping ai College of Resources and Environment HuazhongAgricultural UniversityWuhan 430070China Waste Science and Technology Department of CivilEnvironmental and Natural Resources EngineeringLulea University of TechnologySE-97187 LuleaSweden College of Engineering Huazhong Agricultural UniversityWuhan 430070China

Returning biochar to soil is a heavily researched topic because biochar functions well for soil improvement. There is a significant loss of nutrients, which occurs during biochar preparation before biochar is returned to soil,thereby seriously undermining biochar＇s efficacy. Therefore, the transformation mechanisms of biochar p H,mass, nutrients and metals during pyrolysis under different atmospheres and temperatures were studied such that the best method for biochar preparation could be developed. Several conclusions can be reached：（1） a CO2 atmosphere is better than a N2 atmosphere for biochar preparation, although preparation in a CO2 atmosphere is not a common practice for biochar producers;（2） 350 ℃is the best temperature for biochar preparation because the amount of nutrient loss is notably low based on the premise of straw transferred into biochar; and（3） transforming mechanisms of pH, N, P and K are also involved in the biochar preparation process.

关键词： nutrient Transformation pyrolysis seriously alkaline premise kinetics notably thereby volatile

Parallel Reinforcement Learning-Based Energy Efficiency Improvement for a Cyber-Physical System

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IEEE/CAA Journal of Automatica Sinica 2020年第2期7卷 617-626页

作者： Teng Liu Bin tian Yunfeng ai Fei-Yue Wang Department of Automotive Engineering Chongqing UniversityChongqing 400044 the Vehicle Intelligence Pioneers Inc. Qingdao 266109China the State Key Laboratory of Management and Control for Complex Systems Institute of AutomationChinese Academy of SciencesBeijing 100190China the School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 101408China

As a complex and critical cyber-physical system(CPS),the hybrid electric powertrain is significant to mitigate air pollution and improve fuel *** management strategy(EMS)is playing a key role to improve the energy efficiency of this *** paper presents a novel bidirectional long shortterm memory(LSTM)network based parallel reinforcement learning(PRL)approach to construct EMS for a hybrid tracked vehicle(HTV).This method contains two *** high-level establishes a parallel system first,which includes a real powertrain system and an artificial ***,the synthesized data from this parallel system is trained by a bidirectional LSTM *** lower-level determines the optimal EMS using the trained action state function in the model-free reinforcement learning(RL)*** is a fully data-driven and learning-enabled approach that does not depend on any prediction and predefined ***,real vehicle testing is implemented and relevant experiment data is collected and *** results validate that the proposed EMS can achieve considerable energy efficiency improvement by comparing with the conventional RL approach and deep RL.

关键词： Bidirectional long short-term memory(LSTM)network cyber-physical system(CPS) energy management parallel system reinforcement learning(RL)