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Effects of combustion temperature on the optical properties of brown carbon from biomass burning

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Journal of Environmental Sciences 2024年第3期137卷 302-309页

作者： Peng Gao Rule Deng Song Jia yue Li Xuefei wang Qian xing School of Chemistry Sciences University of Chinese Academy of SciencesBeijing 100049China College of Chemistry and Materials Engineering Beijing Technology and Business UniversityBeijing 100048China

Biomass burning has been known as one of main sources of Brown Carbon(BrC)in atmosphere.In this study,by controlling the combustion temperature at 250℃,350℃,and 450℃,the methanol soluble organic carbon(MSOC)and methanol insoluble carbon(MISC)from pine wood burning was collected by impinger.UV–Vis,excitation emission matrix(EEM),TEM and FTIR spectra were applied to investigate the properties of BrC collected.For MSOC at 250℃ and 350℃,all the spectral profiles of UV–Vis absorption and excitation emission matrix are almost the same,while the EEM of MSOC at 450℃ are different from that of the other two.For MISC fuorescence was observed only in the case of 450℃.In the FTIR spectra,with the temperature increasing the peaks associated to the oxygen-contained functions was weakened,indicating the formation of the fuorophores with larger conjugated system,especially aromatic hydrocarbons.Our results show that biomass combustion at low temperature produces more oxygen-riched BrC,which possesses relatively lower light absorption,while at high temperature produces more aromatics hydrocarbons with relatively strong light absorption.The results of this work are helpful to trace the source of brown carbon and optimize biomass energy utilization.

关键词： Biomass burning Combustion temperature Methanol-soluble brown carbon EEM Impinger

基于网络药理学及体外实验探究野蚕豆根抗氧化活性及其作用机制

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天然产物研究与开发 2024年第1期36卷 155-166页

作者：刘鑫澜朱朋艳马金蓉王星月韦茜高艳梅张冬英袁文娟云南农业大学食品科学技术学院云南农业大学理学院昆明650201 云南省红河州食品药品检验所蒙自661199

利用网络药理学和体外实验探讨野蚕豆根抗氧化活性物质基础及作用机制。首先,采用DPPH法、ABTS法、清除羟自由基法对野蚕豆根进行体外抗氧化实验验证;通过TCMSP数据库和文献搜索筛选出野蚕豆根中的活性物质,同时收集其作用靶点;借助OMIM... 详细信息

利用网络药理学和体外实验探讨野蚕豆根抗氧化活性物质基础及作用机制。首先,采用DPPH法、ABTS法、清除羟自由基法对野蚕豆根进行体外抗氧化实验验证;通过TCMSP数据库和文献搜索筛选出野蚕豆根中的活性物质,同时收集其作用靶点;借助OMIM、GeneCards数据库获得氧化应激相关疾病靶点;将野蚕豆根成分靶点与氧化应激靶点取交集,通过STRING数据库构建蛋白互作网络(protein-protein interaction networks,PPI);利用R语言对交集靶点进行基因本体(GO,Gene Ontology)富集分析和京都基因与基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)富集分析;借助AutoDock 1.5.7软件对核心成分及关键靶点基因进行分子对接,通过Pymol进行可视化操作;利用蛋白质免疫印迹(Western blot)检测进行机制验证。结果显示,野蚕豆根提取物对DPPH自由基、ABTS自由基和羟基自由基有一定的清除能力,其半数抑制浓度(IC_(50))分别为0.166、0.054和0.180 mg/mL;从野蚕豆根中共筛选出22个活性成分,86个成分靶点以及84个交集靶点,其中包括STAT3、HSP90AA1、HDAC1等23个核心靶点;GO富集分析共得到了3386个条目,主要包括碳水化合物结合、核受体活性等分子功能。KEGG富集分析共得到了211个条目,主要包括PI3K-Akt信号通路、化学致癌-受体激活等通路;分子对接结果显示,野蚕豆根中活性成分与核心靶点间结合效应较强,结合能均小于-1.2 kcal/mol;Western blot结果表明,野蚕豆根提取物能明显上调p-PI3K蛋白及p-Akt蛋白的表达。本研究初步表明野蚕豆根提取物可通过激活PI3K-Akt信号通路从而发挥抗氧化作用,为后期野蚕豆根抗氧化活性的研究与应用提供理论依据及参考。

关键词：野蚕豆根抗氧化活性网络药理学分子对接体外实验作用机制

Reinforcement Learning-Based Dynamic Order Recommendation for On-Demand Food Delivery

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Tsinghua Science and Technology 2024年第2期29卷 356-367页

作者： xing wang Ling wang Chenxin Dong Hao Ren Ke xing Department of Automation Tsinghua UniversityBeijing 100080China School of Mechanical and Automotive Engineering Qingdao Hengxing University of Science and TechnologyQingdao 266100China Meituan Beijing 100015China

On-demand food delivery(OFD)is gaining more and more popularity in modern society.As a kernel order assignment manner in OFD scenario,order recommendation directly influences the delivery efficiency of the platform and the delivery experience of riders.This paper addresses the dynamism of the order recommendation problem and proposes a reinforcement learning solution method.An actor-critic network based on long short term memory(LSTM)unit is designed to deal with the order-grabbing conflict between different riders.Besides,three rider sequencing rules are accordingly proposed to match different time steps of the LSTM unit with different riders.To test the performance of the proposed method,extensive experiments are conducted based on real data from Meituan delivery platform.The results demonstrate that the proposed reinforcement learning based order recommendation method can significantly increase the number of grabbed orders and reduce the number of order-grabbing conflicts,resulting in better delivery efficiency and experience for the platform and riders.

关键词： on-demand food delivery order recommendation reinforcement learning actor-critic network long short term memory

High-efficiency crystalline white organic lightemitting diodes

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Light(Science & Applications) 2024年第4期13卷 747-759页

作者： Yijun Liu Feng Zhu yue wang Donghang Yan State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China. School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China. State Key Laboratory of Supramolecular Structure and Materials Jilin UniversityChangchun 130012China

Crystalline white organic light-emitting diodes(C-WOLEDs)are promising candidates for lighting and display applications.It is urgently necessary,however,to develop energy-saving and high-efficiency C-WOLEDs that have stable and powerful emission to meet commercial demands.Here,we report a crystalline host matrix(CHM)with embedded nanoaggregates(NA)structure for developing high-performance C-WOLEDs by employing a thermally activated delayed fluorescence(TADF)material and orange phosphorescent dopants(Phos.-D).The CHM-TADFNA-D WOLED exhibit a remarkable EQE of 12.8%,which is the highest performance WOLEDs based on crystalline materials.The device has a quick formation of excitons and a well-designed energy transfer process,and possesses a fast ramping of luminance and current density.Compared to recently reported high-performance WOLEDs based on amorphous material route,the C-WOLED achieves a low series-resistance Joule-heat loss ratio and an enhanced photon output,demonstrating its significant potential in developing the next-generation WOLEDs.

关键词： diodes dopant crystalline

Holographic Polymer Nanocomposites with High Refractive Index Modulation by Doping Liquid Crystal E6M

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Chinese Journal of Polymer Science 2024年第7期42卷 926-935,I0006页

作者： Meng-Yun wang yue Zhang Dan wang Ming Yao Yi-Xuan wang xing-Ping Zhou Hai-Yan Peng Xiao-Lin Xie Key Laboratory of Material Chemistry for Energy Conversion and Storage Ministry of EducationSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan430074China State Key Laboratory of Materials Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan430074China National Anti-counterfeit Engineering Research Center Huazhong University of Science and TechnologyWuhan430074China

Holographic optical elements(HOEs)based on polymer composites have become a research hot spot in recent years for augmented reality(AR)due to the significant improvement of optical performance,dynamic range,ease of processing and high yield rate.Nevertheless,it remains a formidable challenge to obtain a large field of view(FOV)and brightness due to the limited refractive index modulation.Herein,we report an effective method to tackle the challenge by doping an epoxy liquid crystal termed E6M,which enables a large refractive index modulation of 0.050@633 nm and low haze of 5.0%at a doping concentration of 5 wt%.This achievement may be ascribed to the improved molecular ordering of liquid crystals within the holographic polymer composites.The high refractive index modulation can endow transmission-type holographic polymer composites with a high diffraction efficiency of 96.2%at a small thickness of 5μm,which would promise the design of thin and lightweight AR devices.

关键词： Polymer nanocomposites Holography AR/VR Refractive index modulation Liquid crystal

Cancer stem cell-immune cell crosstalk in the tumor microenvironment for liver cancer progression

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Frontiers of Medicine 2024年第3期18卷 430-445页

作者： yue Ma Hongwei Lv Fuxue xing Wei Xiang Zixin Wu Qiyu Feng Hongyang wang Wen Yang Cancer Research Center First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei230027China National Center for Liver Cancer Naval Medical University(Second Military Medical University)Shanghai201805China International Co-operation Laboratory on Signal Transduction Eastern Hepatobiliary Surgery HospitalNaval Medical University(Second Military Medical University)Shanghai200438China Shanghai Key Laboratory of Hepato-biliary Tumor Biology Shanghai200438China Key Laboratory of Signaling Regulation and Targeting Therapy of Liver Cancer Ministry of EducationShanghai200438China

Crosstalk between cancer cells and the immune microenvironment is determinant for liver cancer progression.A tumor subpopulation called liver cancer stem cells(CSCs)significantly accounts for the initiation,metastasis,therapeutic resistance,and recurrence of liver cancer.Emerging evidence demonstrates that the interaction between liver CSCs and immune cells plays a crucial role in shaping an immunosuppressive microenvironment and determining immunotherapy responses.This review sheds light on the bidirectional crosstalk between liver CSCs and immune cells for liver cancer progression,as well as the underlying molecular mechanisms after presenting an overview of liver CSCs characteristic and their microenvironment.Finally,we discuss the potential application of liver CSCs-targeted immunotherapy for liver cancer treatment.

关键词： liver cancer cancer stem cell immune cell immunotherapy

High speed laser cladding as a new approach to prepare ultra-high temperature ceramic coatings

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Journal of Advanced Ceramics 2024年第2期13卷 143-154页

作者： Qiyao Deng Pengfei He Chuan Sun Yang Li yue xing Yujie wang Jinglong Li Xiubing Liang Xin wang Yujie Zhou Yujun Cai National-Local Joint Engineering Laboratory of Intelligent Manufacturing Oriented Automobile Die&Mould Tianjin University of Technology and EducationTianjin 300222China Defense Innovation Institute Academy of Military ScienceBeijing 100071China School of mechanical engineering Tianjin University of Technology and EducationTianjin 300222China Scientific and Technological Innovation Center Beijing 100012China

Ultra-high temperature ceramic(UHTC)coatings are used to protect the hot-end components of hypervelocity aerocrafts from thermal ablation.This study provides a new approach to fabricate UHTC coatings with high speed laser cladding(HSLC)technology,and places more emphasis on investigating the formation mechanism,phase compositions,and mechanical properties of HSLC-UHTC coatings.Results show that a well-bonded interface between the coating and the tantalum alloy substrate can be formed.The coating is mainly composed of(Zr,Ta)C ceramic solid solution phase with a content of higher than 90% by volume and Ta(W)metal solid solution phase.At a relatively high powder feeding rate,the ZrC ceramic phase appears in the coating while a dense ZrC UHTC top layer with a thickness of up to~50μm is successfully fabricated.As for the mechanical properties of the HSLC coatings,the fracture toughness of the coating decreases with the increase of powder feeding rate.The increase of carbide solid solution phase can significantly improve the high temperature microhardness(552.7±1.8 HV0.5@1000℃).The innovative design of HSLC ZrC-based coatings on refractory alloys accomplishes continuous transitions on microstructure and properties from the substrate to the UHTC top layer,which is a very promising candidate scheme for thermal protection coating.

关键词： high speed laser cladding(HSLC) ultra-high temperature ceramic(UHTC) thermal protection coating microstructure mechanical properties

Switching,explosion,and chaos of multi-wavelength soliton states in ultrafast fiber lasers

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 82-90页

作者： Zhi-Zeng Si yue-yue wang Chao-Qing Dai College of Optical Mechanical and Electrical EngineeringZhejiang A&F UniversityLin’an 311300China

Because of the complexity and difficulty of realizing a multi-wavelength soliton state,reports on its internal dynamic characteristics are scarce.In this study,the switching and periodic soliton explosion processes of the multi-wavelength soliton state in a negative dispersion passively mode-locked fiber laser are realized.The generation of the multi-wavelength soliton state undergoes the process of noise,oscillation,and stable mode-locking,and the splitting and annihilation of solitons with different group velocities directly impact the generation and disappearance of three wavelengths.Positive and negative dispersion lead to different group velocities of solitons.The presence and displacement of solitons with different group velocities cause soliton collisions,which lead to soliton explosions.A soliton experiences relative phase oscillation,chaos,and oscillation,as well as convergence and separation before and after an explosion.With an increase in parameters related to pump power,single-soliton oscillation,multi-wavelength solitons,and chaos are found in experiments and simulations,proving the relevance and reliability between simulation and experimental results.This work promotes the dynamical study of multi-soliton collisions in nonlinear science and the development of chaos theory in multi-comb lasers.

关键词： multi-wavelength fiber laser soliton explosion chaos state switching real-time dynamics

An end‐to‐end infant brain parcellation pipeline

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Intelligent Medicine 2024年第2期4卷 65-74页

作者： Limei wang yue Sun Weili Lin Gang Li Li wang Department of Radiology and Biomedical Research Imaging Center UNC-Chapel HillNew Caledonia27599USA

Objective Accurate infant brain parcellation is crucial for understanding early brain development;however,it is challenging due to the inherent low tissue contrast,high noise,and severe partial volume effects in infant magnetic resonance images(MRIs).The aim of this study was to develop an end-to-end pipeline that enabled accurate parcellation of infant brain MRIs.Methods We proposed an end-to-end pipeline that employs a two-stage global-to-local approach for accurate parcellation of infant brain MRIs.Specifically,in the global regions of interest(ROIs)localization stage,a combination of transformer and convolution operations was employed to capture both global spatial features and fine texture features,enabling an approximate localization of the ROIs across the whole brain.In the local ROIs refinement stage,leveraging the position priors from the first stage along with the raw MRIs,the boundaries of the ROIs are refined for a more accurate parcellation.Results We utilized the Dice ratio to evaluate the accuracy of parcellation results.Results on 263 subjects from National Database for Autism Research(NDAR),Baby Connectome Project(BCP)and Cross-site datasets demonstrated the better accuracy and robustness of our method than other competing methods.Conclusion Our end-to-end pipeline may be capable of accurately parcellating 6-month-old infant brain MRIs.

关键词： Infant brain parcellation Isointense magnetic resonance image Convolutional neural networks Transformer