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Polymerization-Amplified Photoacoustic Signal by Enhancing Near-Infrared Light-Harvesting Capacity and Thermal-to-Acoustic Conversion

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Chinese Journal of Polymer Science 2022年第9期40卷 1090-1100页

作者： He-Qi Gao Jing-Tian Zhang Xin-Wen qi Di Jiao Yu-Ning Hong Ke Shan Xiang-Long Kong Dan Ding Key Laboratory of Bioactive Materials Ministry of Educationand College of Life SciencesNankai UniversityTianjin 300071China Center for AIE Research Shenzhen Key Laboratory of Polymer Science and TechnologyGuangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Materials Science and EngineeringCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen 518060China Department of Chemistry and Physics La Trobe Institute for Molecular ScienceLa Trobe UniversityMelbourneVictoria3086Australia Shandong Artificial intelligence Institute and Shandong Computer Science Center Qilu University of TechnologyJinan 250353China

As a frontier imaging technique for biomedical applications,photoacoustic(PA)imaging has been developed rapidly.The development of new design strategies and excellent PA imaging reagents to boost PA conversion is eagerly desirable for high quality PA imaging but complicated to realize.herein,we develop a new strategy in which PA imaging reagents with better properties can be easily optimized by polymerization.A series of new PA imaging reagents were designed and synthesized.The polymerization strategy can effectively promote the PA signal by specifically increasing the thermal-to-acoustic conversion efficiency.As these materials shared the same building units,the optimized effectiveness of polymerization strategy in terms of near-infrared light-harvesting capacity and thermal-to-acoustic conversion efficiency are discussed,rationally.The polymers with intense intramolecular motion exhibit an amplified PA signal by elevating thermal-to-acoustic conversion and its higher light-harvesting capability at redshifted region.The simultaneously strong PA signal and photothermal conversion efficiency of p-TTmB NPs enable precise PA imaging and effective photothermal therapy.This work highlights a simple and available design guideline of polymerization for amplifying the PA effect and optimizing existing materials.

关键词： Intramolecular motion Thermal-to-acoustic conversion Photoacoustic imaging Photothermal conversion efficiency Polymerization

Improving Yolo5 for Real-Time Detection of Small Targets in Side Scan Sonar Images

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Journal of Ocean University of China 2023年第6期22卷 1551-1562页

作者： WANG Jianjun WANG qi gao Guocheng qiN Ping he Bo Faculty of Information Science and Engineering Ocean University of ChinaQingdao 266100China

Side scan sonar(SSS)is an important means to detect and locate seafloor targets.Autonomous underwater vehicles(AUVs)carrying SSS stay near the seafloor to obtain high-resolution images and provide the outline of the target for observers.The target feature information of an SSS image is similar to the background information,and a small target has less pixel information;therefore,accu-rately identifying and locating small targets in SSS images is challenging.We collect the SSS images of iron metal balls(with a diameter of 1m)and rocks to solve the problem of target misclassification.Thus,the dataset contains two types of targets,namely,‘ball’and‘rock’.With the aim to enable AUVs to accurately and automatically identify small underwater targets in SSS images,this study designs a multisize parallel convolution module embedded in state-of-the-art Yolo5.An attention mechanism transformer and a convolutional block attention module are also introduced to compare their contributions to small target detection accuracy.The performance of the proposed method is further evaluated by taking the lightweight networks Mobilenet3 and Shufflenet2 as the backbone network of Yolo5.This study focuses on the performance of convolutional neural networks for the detection of small targets in SSS images,while another comparison experiment is carried out using traditional HOG+SVM to highlight the neural network’s ability.This study aims to improve the detection accuracy while ensuring the model efficiency to meet the real-time working requirements of AUV target detection.

关键词： side scan sonar images autonomous underwater vehicle multisize parallel convolution module attention mechanism

Waste to treasure:Reutilization of fluid catalytic cracking coke block as photothermal conversion material for water evaporation

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Particuology 2024年第5期88卷 62-70页

作者： Zhuwei gao Chengxin Li Jingjing he Zhuo Wang Xinyu qi Lan he Shihao Wang Zhongxin Liu School of Chemical Engineering and Technology Hainan UniversityHaikou 570228China TJ-YZ School of Network Science Haikou University of EconomicsHaikou 570203China School of Food Science and Engineering Hainan UniversityHaikou 570228China Key Laboratory of Advanced Materials of Tropical Island Resources of Ministry of Education Hainan UniversityHaikou 570228China Hainan Provincial Key Laboratory of Fine Chemicals Hainan UniversityHaikou 570228China

This study aims to analyze the coking process and propose an effective method for the reutilization of fluid catalytic cracking(FCC)coke block.herein,we analyzed the basic characteristics and chemical composition of FCC coke blocks.The results showed that the main components were carbon,oxygen,and aluminum,accounting for 60.8%,26.6%,and 11.5%,respectively.Under the conventional catalytic cracking reaction temperature from 500°C to 600°C,the formation of the first aromatic hydrocarbon was particularly important for the formation of coke.The condensation of oil-gas-entrained catalyst particles and their heavy components was the physical cause of coking,while the dehydrogenation condensation reaction of oil-gas heavy components was the chemical factor.In addition,the membrane prepared by powdered coke had excellent photothermal conversion ability,which could be heated to more than 110°C within 360 s under two fixed light intensities.The evaporation rate of photothermal water was 5.89 kg m 2 h−1,which has great industrial application potential.These works provide a novel and effective method of separation membrane for the reutilization of FCC coke blocks.

关键词： Coking process Reutilization of FCC coke Carbonaceous deposition Membrane Photothermal conversion

Efficient and robust CNN-LSTM prediction of flame temperature aided light field online tomography

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Science China(Technological Sciences) 2024年第1期67卷 271-284页

作者： NIU ZhiTian qi Hong SUN AnTai REN YaTao he MingJian gao BaoHai School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China Key Laboratory of Aerospace Thermophysics Ministry of Industry and Information TechnologyHarbin 150001China

Light field tomography,an optical combustion diagnostic technology,has recently attracted extensive attention due to its easy implementation and non-intrusion.However,the conventional iterative methods are high data throughput,low efficiency and time-consuming,and the existing machine learning models use the radiation spectrum information of the flame to realize the parameter field measurement at the current time.It is still an offline measurement and cannot realize the online prediction of the instantaneous structure of the actual turbulent combustion field.In this work,a novel online prediction model of flame temperature instantaneous structure based on deep convolutional neural network and long short-term memory(CNN-LSTM)is proposed.The method uses the characteristics of local perception,shared weight,and pooling of CNN to extract the threedimensional(3D)features of flame temperature and outgoing radiation images.Moreover,the LSTM is used to comprehensively utilize the ten historical time series information of high dynamic combustion flame to accurately predict 3D temperature at three future moments.A chaotic time-series dataset based on the flame radiation forward model is built to train and validate the performance of the proposed CNN-LSTM model.It is proven that the CNN-LSTM prediction model can successfully learn the evolution pattern of combustion flame and make accurate predictions.

关键词： temperature prediction convolutional neural network long short-term memory light field imaging online tomography

Ir0/graphdiyne atomic interface for selective epoxidation

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National Science Review 2023年第8期10卷 173-179页

作者： Zhiqiang Zheng Lu qi Yaqi gao Xiaoyu Luan Yurui Xue Feng he Yuliang Li Shandong Provincial Key Laboratory for Science of Material Creation and Energy Conversion Science Center for Material Creation and Energy Conversion School of Chemistry and Chemical EngineeringShandong University CAS Key Laboratory of Organic Solids Institute of ChemistryChinese Academy of Sciences School of Chemical Sciences University of Chinese Academy of Sciences

The development of catalysts that can selectively and efficiently promote the alkene epoxidation at ambient temperatures and pressures is an important promising path to renewable synthesis of various chemical products. here we report a new type of zerovalent atom catalysts comprised of zerovalent Ir atoms highly dispersed and anchored on graphdiyne(Ir0/GDY) wherein the Ir0is stabilized by the incomplete charge transfer effect and the confined effect of GDY natural cavity. The Ir0/GDY can selectively and efficiently produce styrene oxides(SO) by electro-oxidizing styrene(ST) in aqueous solutions at ambient temperatures and pressures with high conversion efficiency of ～100%, high SO selectivity of 85.5%, and high Faradaic efficiency(FE) of 55%. Experimental and density functional theory(DFT) calculation results show that the intrinsic activity and stability due to the incomplete charge transfer between Ir0and GDY effectively promoted the electron exchange between the catalyst and reactant molecule, and realized the selective epoxidation of ST to SO. Studies of the reaction mechanism demonstrate that Ir0/GDY proceeds a distinctive pathway for highly selective and active alkene-to-epoxide conversion from the traditional processes. This work presents a new example of constructing zerovalent metal atoms within the GDY matrix toward selective electrocatalytic epoxidation.

关键词： graphdiyne atom catalyst atomic interface selective epoxidation high-performance

Comparisons and Improvements of Key Operating Characteristics of Current Source Converter Applied in HVDC System

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CSEE Journal of Power and Energy Systems 2023年第5期9卷 1601-1612页

作者： Wenwen Zhang Longlong Chen Xiaoguang Wei Guangfu Tang Lei qi Chong gao Zhiyuan he the North China Electric Power University Beijing 102206China the State Key Laboratory of Advanced Power Transmission Technology Beijing Institute Of Smart EnergyBeijing 102206China the State Grid Smart Grid Research Institute Co.Ltd Beijing 102209China

Because of its controlled power factor and no commutation failure,current source converter(CSC)made up of reverse-blocking IGCTs(RB-IGCTs)offers broad application prospects in the field of HVDC system.Valve voltage and power operating range as the most important operating characteristics should be paid attention to but they are always contradictory.First,the relationship between valve voltage and modulation index is obtained.In particular,valve voltage of converter under the three typical modulation methods is compared,analyzed,and verified.Second,with the help of the independent control strategy and coordinated control strategy of both ends,power operating ranges of the three modulation methods are comprehensively analyzed and compared.Third,in order to solve power coupling at a low active power,the improved coordination control strategy at both ends in this paper is proposed and the relationships among active power,reactive power,DC current and phase angle difference are given in detail.Finally,a 500 kV/3 kA simulation system was built in PSCAD/EMTDC to obtain comparison results of the key operating characteristics of CSC under different modulation methods and the converter can realize unity power operation under random active power after adopting the improved coordinated control strategy,and DC current does not decrease to zero,verifying effectiveness of the coordinated control strategy.

关键词： Current source converter improved coordinated control strategy reverse-blocking IGCT valve voltage

Construction of a mutant of Actinoplanes sp. N902-109 that produces a new rapamycin analog

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Chinese Journal of Natural Medicines 2018年第3期16卷 210-218页

作者： HUANG he gao Ping ZHAO qi HU Hai-Feng Shanghai Institute of Pharmaceutical Industry Shanghai 201203 China Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai 200032 China

In the present study, we introduced point mutations into Ac_rap A which encodes a polyketide synthase responsible for rapamycin biosynthesis in Actinoplanes sp. N902-109, in order to construct a mutant with an inactivated enoylreductase(ER) domain, which was able to synthesize a new rapamycin analog. Based on the homologous recombination induced by double-strand breaks in chromosome mediated by endonuclease I-SceI, the site-directed mutation in the first ER domain of Ac_rapA was introduced using non-replicating plasmid pL YERIA combined with an I-SceI expression plasmid. Three amino acid residues of the active center, Ala-Gly-Gly, were converted to Ala-Ser-Pro. The broth of the mutant strain SIPI-027 was analyzed by HPLC and a new peak with the similar UV spectrum to that of rapamycin was found. The sample of the new peak was prepared by solvent extraction, column chromatography, and crystallization methods. The structure of new compound, named as SIPI-rapxin, was elucidated by determining and analyzing its MS and NMR spectra and its biological activity was assessed using mixed lymphocyte reaction(MLR). An ER domain–deficient mutant of Actinoplanes sp. N902-109, named as SIPI-027, was constructed, which produced a novel rapamycin analog SIPI-rapxin and its structure was elucidated to be 35, 36-didehydro-27-O-demethylrapamycin. The biological activity of SIPI-rapxin was better than that of rapamycin. In conclusion, inactivation of the first ER domain of rap A, one of the modular polyketide synthase responsible for macro-lactone synthesis of rapamycin, gave rise to a mutant capable of producing a novel rapamycin analog, 35, 36-didehydro-27-O-demethylrapamycin, demonstrating that the enoylreductase domain was responsible for the reduction of the double bond between C-35 and C-36 during rapamycin synthesis.

关键词： Actinoplanes sp。N902-109 Rapamycin 结构的类似物 Polyketide synthase Enoylreductase

Integrated neural tracing and in-situ barcoded sequencing reveals the logic of SCN efferent circuits in regulating circadian behaviors

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Science China(Life Sciences) 2024年第3期67卷 518-528页

作者： Meimei Liao Xinwei gao Chen Chen qi Li qingchun Guo he Huang Erquan Zhang Dapeng Ju College of Biological Sciences China Agriculture UniversityBeijing 100193China National Institute of Biological Sciences(NIBS) Beijing 102206China Chinese Institute for Brain Research Beijing 102206China School of Biomedical Engineering Capital Medical UniversityBeijing 100069China Department of Anesthesiology The Second Affiliated HospitalChongqing Medical UniversityChongqing 401336China Tsinghua Institute of Multidisciplinary Biomedical Research Tsinghua UniversityBeijing 102206China

The circadian clock coordinates rhythms in numerous physiological processes to maintain organismal homeostasis. Since the suprachiasmatic nucleus(SCN) is widely accepted as the circadian pacemaker, it is critical to understand the neural mechanisms by which rhythmic information is transferred from the SCN to peripheral clocks. here, we present the first comprehensive map of SCN efferent connections and suggest a molecular logic underlying these projections. The SCN projects broadly to most major regions of the brain, rather than solely to the hypothalamus and thalamus. The efferent projections from different subtypes of SCN neurons vary in distance and intensity, and blocking synaptic transmission of these circuits affects circadian rhythms in locomotion and feeding to different extents. We also developed a barcoding system to integrate retrograde tracing with in-situ sequencing, allowing us to link circuit anatomy and spatial patterns of gene expression. Analyses using this system revealed that brain regions functioning downstream of the SCN receive input from multiple neuropeptidergic cell types within the SCN, and that individual SCN neurons generally project to a single downstream brain region.This map of SCN efferent connections provides a critical foundation for future investigations into the neural circuits underlying SCNmediated rhythms in physiology. Further, our new barcoded tracing method provides a tool for revealing the molecular logic of neuronal circuits within heterogeneous brain regions.

关键词： circadian rhythms SCN output circuit neural tracing barcoded GFP in situ sequencing

Microstructure and microhardness of aluminium alloy with underwater and in-air wire-feed laser deposition

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International Journal of Minerals,Metallurgy and Materials 2023年第4期30卷 670-677页

作者： Ning Guo qi Cheng Yunlong Fu Yang gao Hao Chen Shuai Zhang Xin Zhang Jinlong he State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Shandong Provincial Key Laboratory of Special Welding Technology Harbin Institute of Technology at WeihaiWeihai 264209China Shandong Institute of Shipbuilding Technology Weihai 264209China School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China China Oil&Gas Pipeline Network Corporation Beijing 100101China

This study carried out the underwater and in-air wire-feed laser deposition of an aluminium alloy with a thin-walled tubular structure. For both the underwater and in-air deposition layers, both were well-formed and incomplete fusion, cracks, or other defects did not exist.Compared with the single-track deposition layer in air, the oxidation degree of the underwater single-track deposition layer was slightly higher.In both the underwater and in-air deposition layers, columnar dendrites nucleated close to the fusion line and grew along the direction of the maximum cooling rate in the fusion region(FR), while equiaxed grains formed in the deposited region(DR). As the environment changed from air to water, the width of DR and height of FR decreased, but the deposition angle and height of DR increased. The grain size and ratio of the high-angle boundaries also decreased due to the large cooling rate and low peak temperature in the water environment.Besides, the existence of a water environment benefitted the reduction of magnesium element burning loss in the DR. The microhardness values of the underwater deposition layer were much larger than those of the in-air layer, owing to the fine grains and high magnesium content.

关键词： wire-feed laser deposition microstructure magnesium element burn loss microhardness