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The synthesis of fluorescent nanoclusters based on the etching reaction

Nano Research 2024年第5期17卷 4631-4638页

作者： Hongbin Lin Yitao Cao qiaofeng yao Tiankai Chen Huiting Shan Jianping Xie Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350207China Department of Chemical and Biomolecular Engineering National University of SingaporeSingapore 117585Singapore National and Local Joint Engineering Research Center of MPTES in High Energy and Safety LIBs Engineering Research Center of MTEES(Ministry of Education)and Key Laboratory of ETESPG(GHEI)South China Normal UniversityGuangzhou 510006China Tianjin Key Laboratory of Molecular Optoelectronic Sciences Key Laboratory of Integrated Organic CircuitsMinistry of EducationDepartment of ChemistrySchool of ScienceTianjin UniversityTianjin 300072China

Thiolate-protected atomically precise nanoclusters(NCs)demonstrate a series of unique luminescent characteristics attributed to their various peculiar electronic structures.Therefore,fluorescent NCs present extraordinary practical values in biosensing and bioimaging research fields.Nevertheless,restricted by the types of fluorescent NCs,there are great difficulties in promoting the development of NCs in fluorescent research areas.As a result,it is of significant necessity for researchers to develop new synthetic pathways to produce high-quality fluorescent NCs.According to the analysis about the structural characteristics of fluorescent NCs,some general features like longer motif and higher ligand-to-metal ratio can be found,consistent to some presented regularities in etching reaction.Consequently,in this work,we used Au_(25)(MHA)_(18)(MHA=6-mercaptohexanoic acid)as a model nanocluster and utilized the etching reaction to systematically explore etching products and their corresponding luminescent properties.Moreover,we also identified three main reaction processes in the entire etching reaction process,which can generate new metal nanocluster species with various fluorescent properties.Hence,the etching reaction will provide a good platform to produce new luminescent metal NC species.

关键词： etching reaction metal nanoclusters fluorescent properties fluorescent conversion

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Ligand-dependent aggregation-enhanced photoacoustic of atomically precise metal nanocluster

Aggregate

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Aggregate 2024年第1期5卷 196-203页

作者： Changlin Zhou Meng Wang qiaofeng yao Yu Zhou Chuantao Hou Jianfei Xia Zonghua Wang Jishi Chen Jianping Xie College of Chemistry and Chemical Engineering Shandong Sino-Japanese Center for Collaborative Research of Carbon NanomaterialsInstrumental Analysis Center of Qingdao UniversityQingdao UniversityQingdaoP.R.China Tianjin Key Laboratory of Molecular Optoelectronic Sciences Department of ChemistrySchool of ScienceTianjin UniversityTianjinP.R.China Qingdao Boting Hydrogen Age Ocean Technol R&D Ctr. Qingdao Boting Technol Co.Ltd.Shandong Hydrogen Times Marine Technology Co.Ltd.QingdaoP.R.China Department of Chemical and Biomolecular Engineering National University of SingaporeSingapore Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityBinhai New CityFuzhouP.R.China

Atomically precise metal nanoclusters(MNCs),as a potential type of photoacoustic(PA)contrast agent,are limited in application due to their low PA conversion efficiency(PACE).Here,with hydrophilic Au25SR18(SR=thiolate)as model NCs,we present a result that weakly polar solvent induces aggregation,which effectively enhances PA intensity and PACE.The PA intensity and PACE are highly dependent on the degree of aggregation,while the aggregation-enhanced PA intensity(AEPA)positively correlates to the protected ligands.Such an AEPA phenomenon indicates that aggregation actually accelerates the intramolecular motion of Au NCs,and enlarges the proportion of excited state energy dissipated through vibrational relaxation.This result conflicts with the restriction of intramolecular motion mechanism of aggregation-induced emission.Further experiments show that the increased energy of AEPA originates from the aggregation inhibiting the intermolecular energy transfer from excited Au NCs to their surrounding medium molecules,including solvent molecule and dissolved oxygen,rather than restricting radiative relaxations.This study develops a new strategy for enhancing the PA intensity of Au NCs,and contributes to a deeper understanding of the origin of the PA signal and the excited state energy dissipation processes for MNCs.

关键词： aggregation-enhanced photoacoustic gold nanocluster intermolecular excited state energy transfer intramolecular motion ligand effect

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Identification of chemical compositions from“featureless”optical absorption spectra:Machine learning predictions and experimental validations

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Nano Research 2023年第3期16卷 4188-4196页

作者： Tiankai Chen Jiali Li Pengfei Cai qiaofeng yao Zekun Ren Yixin Zhu Saif Khan Jianping Xie Xiaonan Wang Department of Chemical and Biomolecular Engineering National University of Singapore4 Engineering Drive 4Singapore 117585Singapore Department of Materials Science and Engineering National University of Singapore9 Engineering Drive 1Singapore 117575Singapore Singapore-MIT Alliance for Research and Technology(SMART) 1 CREATE WaySingapore 138602Singapore Department of Chemical Engineering Tsinghua UniversityBeijing 100084China

Rapid and accurate chemical composition identification is critically important in chemistry.While it can be achieved with optical absorption spectrometry by comparing the experimental spectra with the reference data when the chemical compositions are simple,such application is limited in more complicated scenarios especially in nano-scale research.This is due to the difficulties in identifying optical absorption peaks(i.e.,from“featureless”spectra)arose from the complexity.In this work,using the ultraviolet-visible(UV-Vis)absorption spectra of metal nanoclusters(NCs)as a demonstration,we develop a machine-learningbased method to unravel the compositions of metal NCs behind the“featureless”spectra.By implementing a one-dimensional convolutional neural network,good matches between prediction results and experimental results and low mean absolute error values are achieved on these optical absorption spectra that human cannot interpret.This work opens a door for the identification of nanomaterials at molecular precision from their optical properties,paving the way to rapid and high-throughput characterizations.

关键词： gold nanoclusters composition identification optical absorption machine learning convolutional neural network

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A novel topology with controllable wideband baseband impedance for power amplifiers

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Frontiers of Information Technology & Electronic Engineering 2024年第2期25卷 308-315页

作者： yao yao Zhijiang DAI Mingyu LI School of Intelligent Technology and Engineering Chongqing University of Science and TechnologyChongqing400065China School of Microelectronics and Communication Engineering Chongqing UniversityChongqing400065China

This paper presents a novel topology to control the baseband impedance of a power amplifier(PA)to avoid performance deterioration in concurrent dual-band mode.This topology can avoid pure resonance of capacitors and inductors LC,which leads to a high impedance at some frequency points.Consequently,it can be applied to transmitters that are excited by broadband signals.In particular,by adjusting the circuit parameters and increasing stages,the impedance of the key frequency bands can be flexibly controlled.A PA is designed to support this design idea.Its saturated output power is around 46.7 dBm,and the drain efficiency is>68.2%(1.8-2.3 GHz).Under concurrent two-tone excitation,the drain efficiency reaches around 40%even under 5.5 dB back-off power with the tone spacing from 10 MHz to 500 MHz.These results demonstrate that the proposed topology is capable of controlling wideband baseband impedance.

关键词： Baseband impedance Concurrent dual-band Power amplifier

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Aggregation-induced emission in luminescent metal nanoclusters

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National Science Review 2021年第6期8卷 18-20页

作者： Zhennan Wu qiaofeng yao Shuang-quan Zang Jianping Xie Department of Chemical and Biomolecular Engineering National University of Singapore Green Catalysis Center and College of ChemistryZhengzhou University Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University

Few-to hundred-atom luminescent metal nanoclusters(NCs) protected by an organic monolayer have recently emerged as a novel class of chromophores, with facile preparation,ultrafine size, low toxicity, high renal clearance and excellent photostability[1]. Luminescent metal NCs hold great promise for broad applications in lighting, imaging, sensing and therapeutics [2]; however,

关键词： GOLD COMPLEXES CLUSTERS SHINE

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New progress of small-molecule drugs in the treatment of inflammatory bowel disease

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Chinese Medical Journal 2024年第5期137卷 556-558页

作者： Dongying yao Zhihua Ran Department of Gastroenterology Zhou Pu Hospital affiliated to Shanghai University of Health&Medical SciencesShanghai 201318China

With the advent of small-molecule drugs,treatment of inflammatory bowel disease(IBD)has reached a new stage.In contrast to biologics,small-molecule drugs can be made into oral dosage forms with a short half-life and are suitable for administration 1–2 times a day.Small-molecule drugs work by inhibiting the transmission of key intracellular signaling pathways in the pathogenesis of ulcerative colitis(UC)and Crohn’s disease(CD)[Figure 1].They do not induce anti-drug antibodies in patients or lead to loss of response after treatment.

关键词： drugs treatment inflammatory

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Fresh-Keeping Decision and Coordination of Fresh Agricultural Product Supply Chain Considering Carbon Cap-and-Trade under Different Dominance

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Journal of Systems Science and Systems Engineering 2024年第1期33卷 30-51页

作者： Yang Yang Guanxin yao China Institute for Agricultural Equipment Industrial Development Jiangsu UniversityZhenjiang212013China Jiangsu Modern Logistics Research Base Yangzhou UniversityYangzhou225009China

In the context of low carbon,this paper discussed the impact of the carbon cap-and-trade policy on the fresh-keeping decision-making of two-echelon fresh agricultural product supply chains under different dominance,and designed cost-sharing contracts to coordinate the supply chain of fresh agricultural products dominated by suppliers and retailers respectively.The results showed that:dominance has no effect on the fresh-keeping decision and total revenue of fresh agricultural product supply chain,but it affects the internal income distribution,and dominance does not always bring more benefits;the implementation of carbon cap-and-trade reduces the fresh-keeping decision-making of fresh agricultural products supply chain and reduces the free-rider income of followers;the role of higher carbon trading price is twofold,which not only brings about the speculation of leading enterprises,but also promotes the application of low-carbon technologies;consumers’high preference for freshness,low-cost and high-efficiency low-carbon technology are all conducive to improving the fresh-keeping efforts and benefits of the supply chain;cost-sharing contracts can coordinate the supply chain of fresh agricultural products.

关键词： Dominant power carbon cap-and-trade policy fresh agricultural product supply chain fresh-keeping decision-making

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Analysis of influencing factors of anxiety and depression in patients with periodontitis

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World Journal of Psychiatry 2024年第1期14卷 141-147页

作者： yao Kong Department of Stomatology Xinxiang Central HospitalXinxiang 453000Henan ProvinceChina

BACKGROUND Periodontitis is a chronic oral disease caused by pathogenic microorganisms that corrode tooth tissue,form periodontal pockets,absorb alveolar bone,and finally lead to tooth loss.During treatment,patients are prone to anxiety,tension,and other negative emotions,which affect their ability to face the disease and may also lead to aggravation of the original condition and affect oral health.Therefore,it is important to improve the negative psychology of patients with periodontitis to clarify the factors that may lead to negative psychological emotions.AIM To investigate the risk factors that may lead to anxiety and depression in patients with periodontitis.METHODS One hundred patients with periodontitis were selected between March 2022 and March 2023 at our hospital.All patients were assessed with the Zung Self-rating Depression Scale(SDS)(≥53 points indicate a depressive state)and Zung Selfrating Anxiety Scale(SAS)(≥50 points indicates an anxious state).In this study,patients who experienced anxiety or depression were included in the occurrence group and those without anxiety or depression were included in the nonoccurrence group.The baseline data of the two groups were compared to explore the risk factors for anxiety and depression in patients with periodontitis.RESULTS A total of 100 patients with periodontitis were included in this study.According to the SDS,38 patients(38.00%)developed depression,with an average SDS score of(68.52±5.85)points.According to the SAS,40 patients(40.00%)developed anxiety,and the average SAS score was(72.15±4.15)points.In this study,56 patients with anxiety or depression were included.Compared with the nonoccurrence group,the occurrence group had higher ages(≥60 years),lower level of hope(low level),educational level(high school or below),disease perception(poor),and sleep disorder(yes).The negative coping dimension scores of the simplified coping style questionnaire(SCSQ)and Dental Fear Scale(DFS)in the occurrence group were higher,whereas the score of the positive coping

关键词： Periodontitis Anxiety Depression Mental state Influencing factor

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Limits of Uneven Battery Power in Modular Multilevel Converter-based Battery Energy Storage Systems

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 686-695页

作者： yao Pan Xiaofeng Sun Wei Zhao Xin Li yao Cai Institute of Electrical Engineering Yanshan UniversityQinhuangdao 066004China

For modular multilevel converter-based battery energy storage systems (MMC-BESS), uneven power among batteries of SMs will be deduced by battery aging, battery fault, etc., which will degrade performance and even lead to system failure. For maintaining the balance of capacitor voltage, this paper analyzes the limits of the uneven power of batteries, which are presented as the current limits in this paper. According to analysis, an analytical method is proposed that only the dc and fundamental frequency components of the arm current are used to calculate current limits. With the current limits it is able to evaluate the reasonability of power distribution among batteries. Meanwhile, increase of fundamental frequency component will enhance the current limits, and the dc component determines the size relationship between the absolute values of the upper and lower current limits. Finally, simulation model and experiment prototype are built for verifying the theoretical analysis and current limits calculation method, and satisfactory results are provided.

关键词： Arm current balance of capacitor voltage current limits MMC-BESS uneven power

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Reinforcement learning based adaptive control for uncertain mechanical systems with asymptotic tracking

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Defence Technology（防务技术） 2024年第4期34卷 19-28页

作者： Xiang-long Liang Zhi-kai yao yao-wen Ge Jian-yong yao School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China College of Automation&College of Artificial Intelligence Nanjing University of Post and TelecommunicationNanjing210023China

This paper mainly focuses on the development of a learning-based controller for a class of uncertain mechanical systems modeled by the Euler-Lagrange formulation.The considered system can depict the behavior of a large class of engineering systems,such as vehicular systems,robot manipulators and satellites.All these systems are often characterized by highly nonlinear characteristics,heavy modeling uncertainties and unknown perturbations,therefore,accurate-model-based nonlinear control approaches become unavailable.Motivated by the challenge,a reinforcement learning(RL)adaptive control methodology based on the actor-critic framework is investigated to compensate the uncertain mechanical dynamics.The approximation inaccuracies caused by RL and the exogenous unknown disturbances are circumvented via a continuous robust integral of the sign of the error(RISE)control approach.Different from a classical RISE control law,a tanh(·)function is utilized instead of a sign(·)function to acquire a more smooth control signal.The developed controller requires very little prior knowledge of the dynamic model,is robust to unknown dynamics and exogenous disturbances,and can achieve asymptotic output tracking.Eventually,co-simulations through ADAMS and MATLAB/Simulink on a three degrees-of-freedom(3-DOF)manipulator and experiments on a real-time electromechanical servo system are performed to verify the performance of the proposed approach.

关键词： Adaptive control Reinforcement learning Uncertain mechanical systems Asymptotic tracking

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