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Combining reinforcement learning with mathematical programming:An approach for optimal design of heat exchanger networks

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Chinese Journal of Chemical Engineering 2024年第5期69卷 63-71页

作者： Hui Tan Xiaodong Hong Zuwei liao Jingyuan Sun Yao Yang Jingdai Wang Yongrong Yang State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310027China ZJU-Hangzhou Global Scientific and Technological Innovation Center Hangzhou 311215China

Heat integration is important for energy-saving in the process *** is linked to the persistently challenging task of optimal design of heat exchanger networks(HEN).Due to the inherent highly nonconvex nonlinear and combinatorial nature of the HEN problem,it is not easy to find solutions of high quality for large-scale *** reinforcement learning(RL)method,which learns strategies through ongoing exploration and exploitation,reveals advantages in such ***,due to the complexity of the HEN design problem,the RL method for HEN should be dedicated and designed.A hybrid strategy combining RL with mathematical programming is proposed to take better advantage of both *** insightful state representation of the HEN structure as well as a customized reward function is introduced.A Q-learning algorithm is applied to update the HEN structure using theε-greedy *** results are obtained from three literature cases of different scales.

关键词： Heat exchanger network Reinforcement learning Mathematical programming Process design

Microstructured Cantilever Probe on Optical Fiber Tip for Microforce Sensor

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Photonic Sensors 2024年第2期14卷 89-99页

作者： Famei WANG Changrui liao Mengqiang ZOU Dejun LIU Haoqiang HUANG Chao LIU Yiping WANG Shenzhen Key Laboratory of Ultrafast Laser Micro/Nano Manufacturing Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education/Guangdong ProvinceCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen 518060China Shenzhen Key Laboratory of Photonic Devices and Sensing Systems for Internet of Things Guangdong and Hong Kong Joint Research Centre for Optical Fibre SensorsState Key Laboratory of Radio Frequency Heterogeneous IntegrationShenzhen UniversityShenzhen 518060China School of Electronics Science Northeast Petroleum UniversityDaqing 163318China

Benefiting from the great advances of the femtosecond laser two-photon polymerization(TPP)technology,customized microcantilever probes can be accurately 3-dimensional(3D)manufactured at the nanoscale size and thus have exhibited considerable potentials in the fields of microforce,micro-vibration,and microforce *** this work,a controllable microstructured cantilever probe on an optical fiber tip for microforce detection is demonstrated both theoretically and *** static performances of the probe are firstly investigated based on the finite element method(FEM),which provides the basis for the structural *** proposed cantilever probe is then 3D printed by means of the TPP *** experimental results show that the elastic constant k of the proposed cantilever probe can be actively tuned from 2.46N/m to 62.35N/*** force sensitivity is 2.5nm/μN,the Q-factor is 368.93,and the detection limit is ***,the mechanical properties of the cantilever probe can be flexibly adjusted by the geometric configuration of the ***,it has an enormous potential for matching the mechanical properties of biological samples in the direct contact mode.

关键词： Optical fiber sensor microforce sensing microstructured cantilever two-photon polymerization

Learning to Branch in Combinatorial Optimization With Graph Pointer Networks

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 157-169页

作者： Rui Wang Zhiming Zhou Kaiwen Li Tao Zhang Ling Wang Xin Xu Xiangke liao IEEE the Xiangjiang Laboratory and the College of Systems Engineering National University of Defense TechnologyChangsha 410073China the Institute of Automation Chinese Academy of SciencesBeijing 100190China the College of Systems Engineering National University of Defense TechnologyChangsha 410073 the Hunan Key Laboratory of Multi-Energy System Intelligent Interconnection Technology Changsha 410073China the Department of Automation Tsinghua UniversityBeijing 100084China the College of Intelligence Science and Technology National University of Defense TechnologyChangsha 410073China the College of Computer Science and Technology National University of Defense TechnologyChangsha 410073China

Traditional expert-designed branching rules in branch-and-bound(B&B) are static, often failing to adapt to diverse and evolving problem instances. Crafting these rules is labor-intensive, and may not scale well with complex *** the frequent need to solve varied combinatorial optimization problems, leveraging statistical learning to auto-tune B&B algorithms for specific problem classes becomes attractive. This paper proposes a graph pointer network model to learn the branch rules. Graph features, global features and historical features are designated to represent the solver state. The graph neural network processes graph features, while the pointer mechanism assimilates the global and historical features to finally determine the variable on which to branch. The model is trained to imitate the expert strong branching rule by a tailored top-k Kullback-Leibler divergence loss function. Experiments on a series of benchmark problems demonstrate that the proposed approach significantly outperforms the widely used expert-designed branching rules. It also outperforms state-of-the-art machine-learning-based branch-and-bound methods in terms of solving speed and search tree size on all the test instances. In addition, the model can generalize to unseen instances and scale to larger instances.

关键词： Branch-and-bound(B&B) combinatorial optimization deep learning graph neural network imitation learning

阿托品滴眼液不同浓度与给药频率对儿童近视患者瞳孔直径、调节幅度及泪膜功能的影响

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海军军医大学学报 2024年第4期45卷 487-494页

作者：胡泊肖婷廖梦霏陈西嘉曾晓黎易姝重庆市人民医院眼科重庆400016

目的探讨不同浓度与给药频率的阿托品滴眼液对儿童近视患者瞳孔直径、调节幅度及泪膜功能的影响。方法选择2018年1月至2021年1月我院接诊的280例近视儿童的左眼数据进行研究。采用随机信封法将患儿分为4组(A、B、C、D组),每组70例(70眼)... 详细信息

目的探讨不同浓度与给药频率的阿托品滴眼液对儿童近视患者瞳孔直径、调节幅度及泪膜功能的影响。方法选择2018年1月至2021年1月我院接诊的280例近视儿童的左眼数据进行研究。采用随机信封法将患儿分为4组(A、B、C、D组),每组70例(70眼)。A组患儿给予0.01%阿托品滴眼液每晚睡前滴眼1次(双眼),B组给予0.01%阿托品滴眼液隔天晚上睡前滴眼1次(双眼),C组给予0.02%阿托品滴眼液每晚睡前滴眼1次(双眼),D组给予0.02%阿托品滴眼液隔天晚上睡前滴眼1次(双眼),每次1滴。比较4组患儿用药前及用药后4、8、12个月的瞳孔直径、调节幅度、等效球镜度、眼轴长度、前房深度、泪膜功能及不良反应发生情况。结果用药前,4组患儿的瞳孔直径、调节幅度、等效球镜度、眼轴长度、前房深度、泪膜脂质层厚度差异均无统计学意义(均P>0.05)。4组患儿用药前后瞳孔直径、调节幅度、等效球镜度、眼轴长度、前房深度、泪膜脂质层厚度比较差异均无统计学意义(均P组间>0.05),各组用药前后不同时间点瞳孔直径、调节幅度、等效球镜度、眼轴长度、前房深度、泪膜脂质层厚度的变化趋势相同(均P时间>0.05)。4组患儿在用药后各时间点瞳孔直径、等效球镜度均大于用药前,调节幅度均小于用药前(均P0.05),用药后12个月时各组眼轴长度均大于用药前(均P0.05)。各时间点瞳孔直径、调节幅度、等效球镜度、眼轴长度、前房深度、泪膜脂质层厚度组间比较差异均无统计学意义(均P>0.05),且不同疗法与用药时间无交互作用(均P交互>0.05)。用药后1个月内,4组均有部分患儿出现畏强光症状,按意向性分析(ITT)统计分别为A组12例(17.14%)、B组11例(15.71%)、C组16例(22.86%)和D组13例(18.57%),组间比较差异无统计学意义(P>0.05);按符合方案分析(PP)统计分别为A组12例(18.18%)、B组10例(15.62%)、C组14例(20.90%)和D组11例(16.42%),组间比较差异无统计学意义(P>0.05)。还有部分患儿在用药1个月内出现近视阅读模糊症状,按ITT统计分别为A组7例(10.00%)、B组4例(5.71%)、C组6例(8.57%)和D组8例(11.43%),组间比较差异无统计学意义(P>0.05);按PP统计分别为A组5例(7.58%)、B组3例(4.69%)、C组6例(8.96%)和D组5例(7.46%),组间比较差异无统计学意义(P>0.05)。结论质量分数为0.01%、0.02%的阿托品滴眼液每日点眼与隔日点眼对近视儿童的瞳孔直径、调节幅度、等效球镜度的影响趋势一致,且用药后不良反应发生情况无明显差异。

关键词：阿托品浓度给药频率儿童近视

Characterization, preparation, and reuse of metallic powders for laser powder bed fusion: a review

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International Journal of Extreme Manufacturing 2024年第1期6卷 52-91页

作者： Xiaoyu Sun Minan Chen tingting Liu Kai Zhang Huiliang Wei Zhiguang Zhu Wenhe liao School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094People’s Republic of China

Laser powder bed fusion(L-PBF) has attracted significant attention in both the industry and academic fields since its inception, providing unprecedented advantages to fabricate complex-shaped metallic components. The printing quality and performance of L-PBF alloys are infuenced by numerous variables consisting of feedstock powders, manufacturing process,and post-treatment. As the starting materials, metallic powders play a critical role in infuencing the fabrication cost, printing consistency, and properties. Given their deterministic roles, the present review aims to retrospect the recent progress on metallic powders for L-PBF including characterization, preparation, and reuse. The powder characterization mainly serves for printing consistency while powder preparation and reuse are introduced to reduce the fabrication *** powder characterization and preparation methods are presented in the beginning by analyzing the measurement principles, advantages, and limitations. Subsequently, the effect of powder reuse on the powder characteristics and mechanical performance of L-PBF parts is analyzed, focusing on steels, nickel-based superalloys, titanium and titanium alloys, and aluminum alloys. The evolution trends of powders and L-PBF parts vary depending on specific alloy systems, which makes the proposal of a unified reuse protocol infeasible. Finally,perspectives are presented to cater to the increased applications of L-PBF technologies for future investigations. The present state-of-the-art work can pave the way for the broad industrial applications of L-PBF by enhancing printing consistency and reducing the total costs from the perspective of powders.

关键词： laser powder bed fusion powder characterization powder preparation powder reuse

Distributed Secondary Control Based on Dynamic Diffusion Algorithm for Current Sharing and Average Voltage Regulation in DC Microgrids

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 597-607页

作者： Dawei liao Fei Gao Daniel J.Rogers Wentao Huang Dong Liu Houjun Tang Department of Electrical Engineering Shanghai Jiao Tong UniversityShanghaiChina Department of Engineering Science University of OxfordOxford OX12JDU.K. IEEE

This paper introduces a distributed secondary control scheme for achieving current sharing and average voltage regulation objectives in a DC *** proposed scheme employs a dynamic diffusion algorithm(DDA)instead of the consensus algorithm to enable distributed communication among *** help understand DDA,the relation of DDA and other diffusion algorithms is discussed in detail and its superiority is shown by comparison with diffusion and consensus ***,considering the discrete nature and different sampling time of the digital controller and communication network,a z-domain model of the entire DC microgrid is *** influence of communication and secondary control parameters on the system stability is *** on the established model,the tolerable communication rates are ***-time simulations conducted on the OPAL-RT platform validate the effectiveness of the proposed scheme,showcasing its advantages in terms of convergence speed and stability.

关键词： Cooperative control DC microgrid diffusion algorithm discrete-time modeling distributed secondary control

Synergy of heterogeneous Co/Ni dual atoms enabling selective C-O bond scission of lignin coupling with in-situ N-functionalization

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Journal of Energy Chemistry 2024年第5期92卷 16-25页

作者： Baoyu Wang Jinshu Huang Hongguo Wu Ximing Yan Yuhe liao Hu Li National Key Laboratory of Green Pesticide Key Laboratory of Green Pesticide&Agricultural BioengineeringMinistry of EducationState-Local Joint Laboratory for Comprehensive Utilization of BiomassCollege of Pharmacy&Center for R&D of Fine ChemicalsGuizhou UniversityGuiyang 550025GuizhouChina Guangxi Key Laboratory of Green Chemical Materials and Safety Technology Beibu Gulf UniversityQinzhou 535011GuangxiChina Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640GuangdongChina

Selective cleavage of Csp^(2)-OCH_(3)bond in lignin without breaking other types of C-O bonds followed by N-functionalization is fascinating for on-purpose valorization of ***,a Co/Ni-based dual-atom catalyst CoNiDA@NC prepared by in-situ evaporation and acid-etching of metal species from tailor-made metal–organic frameworks was efficient for reductive upgrading of various lignin-derived phenols to cyclohexanols(88.5%–99.9%yields),which had ca.4 times higher reaction rate than the single-atom catalyst and was superior to state-of-the-art heterogeneous *** synergistic catalysis of Co/Ni dual atoms facilitated both hydrogen dissociation and hydrogenolysis steps,and could optimize adsorption configuration of lignin-derived methoxylated phenols to further favor the Csp^(2)-OCH_(3)cleavage,as elaborated by theoretical ***,the CoNi_(DA)@NC catalyst was highly recyclable,and exhibited excellent demethoxylation performance(77.1%yield)in real lignin monomer *** in-situ cascade conversion processes assisted by dual-atom catalysis,various high-value N-containing chemicals,including caprolactams and cyclohexylamines,could be produced from lignin.

关键词： Biomass conversion Heterogeneous catalysis Lignin Dual-atom catalyst Selective C-ocleavage

CNN-LSTM based incremental attention mechanism enabled phase-space reconstruction for chaotic time series prediction

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Journal of Electronic Science and Technology 2024年第2期22卷 77-90页

作者： Xiao-Qian Lu Jun Tian Qiang liao Zheng-Wu Xu Lu Gan Bidding and Purchasing Center University of Electronic Science and Technology of ChinaChengdu611731China Yibin Research Institute University of Electronic Science and Technology of ChinaYibin644000China School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu611731China

To improve the prediction accuracy of chaotic time series and reconstruct a more reasonable phase space structure of the prediction network,we propose a convolutional neural network-long short-term memory(CNN-LSTM)prediction model based on the incremental attention ***,a traversal search is conducted through the traversal layer for finite parameters in the phase ***,an incremental attention layer is utilized for parameter judgment based on the dimension weight criteria(DWC).The phase space parameters that best meet DWC are selected and fed into the input ***,the constructed CNN-LSTM network extracts spatio-temporal features and provides the final prediction *** model is verified using Logistic,Lorenz,and sunspot chaotic time series,and the performance is compared from the two dimensions of prediction accuracy and network phase space ***,the CNN-LSTM network based on incremental attention is compared with long short-term memory(LSTM),convolutional neural network(CNN),recurrent neural network(RNN),and support vector regression(SVR)for prediction *** experiment results indicate that the proposed composite network model possesses enhanced capability in extracting temporal features and achieves higher prediction ***,the algorithm to estimate the phase space parameter is compared with the traditional CAO,false nearest neighbor,and C-C,three typical methods for determining the chaotic phase space *** experiments reveal that the phase space parameter estimation algorithm based on the incremental attention mechanism is superior in prediction accuracy compared with the traditional phase space reconstruction method in five networks,including CNN-LSTM,LSTM,CNN,RNN,and SVR.

关键词： Chaotic time series Incremental attention mechanism Phase-space reconstruction

Identification of Shell Color-Associated Genes Using Mantle Branch-Specific RNA Sequencing of Yellow-Colored Line of Pearl Oyster Pinctada fucata martensii

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Journal of Ocean University of China 2024年第4期23卷 1076-1086页

作者： PENG Haiming liao Yongshan YANG Chuangye MKUYE Robert DENG Yuewen YUE Chenyang Fisheries College Guangdong Ocean UniversityZhanjiang 524088China Pearl Research Institute Guangdong Ocean UniversityZhanjiang 524088China Guangdong Science and Innovation Center for Pearl Culture Zhanjiang 524088China Pearl Breeding and Processing Engineering Technology Research Center of Guangdong Province Zhanjiang 524088China Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture Zhanjiang 524088China

The yellow-colored line of pearl oyster Pinctada fucata martensii displays a yellow prismatic layer and a white nacreous layer that can be used as an ideal model for research on shell color ***-Raman spectroscopy and transcriptome analyses were performed to explore the potential molecular mechanism underlying the phenotype *** micro-Raman spectroscopy results indicate that the prismatic layer exhibits distinct characteristic peaks of carotenoids,while these peaks are not prominent in the nacreous *** the transcriptome comparison of the central zone of mantle and mantle edge tissue,which function in nacreous and prismatic layer formation,respectively,935 significantly differentially expressed genes(DEGs)were identified,with 385 genes upregulated and 227 genes downregulated(|log_(2)(Fold change)|>1 and false discovery rate<0.05)in the mantle edge *** these genes,some were associated with melanoma/melanogenesis,such as tyrosinase,zinc metalloprotease,glutathione S-transferase,and ATP-binding cassette sub-family;some were associated with the carotenoid-related pathway,including scavenger receptors,cytochrome P450 and lipoprotein *** associated with porphyrin metabolism,including porphobilinogen deaminase,and copper/zinc superoxide dismutase,and genes associated with shell matrix protein,including amorphous calcium carbonate binding protein,shematrin,PIF,and collagen,also exhibited significantly different *** is speculated that the different colours between prismatic layer and nacreous layer in the yellow-colored line of *** might be resulted from melanin,carotenoids and porphyrin metabolism,while genes related to shell structure and biomineralization might also affect *** results provide new insights to understand the mechanism of shell color formation in mollusca.

关键词： Pinctada fucata martensii shell coloration transcriptome