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Adaptive State-Dependent Diffusion for Derivative-Free Optimization

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1241-1269页

作者： Bjorn Engquist Kui Ren yunan Yang Department of Mathematics and the Oden Institute The University of TexasAustinTX 78712USA Department of Applied Physics and Applied Mathematics Columbia UniversityNew YorkNY10027USA Department of Mathematics Cornell UniversityIthacaNY 14853USA

This paper develops and analyzes a stochastic derivative-free optimization strategy.A key feature is the state-dependent adaptive *** prove global convergence in probability with algebraic rate and give the quantitative results in numerical examples.A striking fact is that convergence is achieved without explicit information of the gradient and even without comparing different objective function values as in established methods such as the simplex method and simulated *** can otherwise be compared to annealing with state-dependent temperature.

关键词： Derivative-free optimization Global optimization Adaptive diffusion Stationary distribution Fokker-Planck theory

Risk Assessment of Multi-Hazards in Hangzhou: A Socioeconomic and Risk Mapping Approach Using the CatBoost-SHAP Model

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INTERNATIONAL JOURNAL OF DISASTER RISK SCIENCE 2024年第4期15卷 640-656页

作者： Yu, Bofan Yan, Jiaxing Li, yunan Xing, Huaixue China Univ Geosci Wuhan Inst Geol Survey Wuhan 430074 Peoples R China China Geol Survey Nanjing Ctr Nanjing 210016 Peoples R China

As the global push for sustainable urban development progresses, this study, set against the backdrop of Hangzhou City, one of China's megacities, addressed the conflict between urban expansion and the occurrence of urban geological hazards. Focusing on the predominant geological hazards troubling Hangzhou-urban road collapse, land subsidence, and karst collapse-we introduced a Categorical Boosting-SHapley Additive exPlanations (CatBoost-SHAP) model. This model not only demonstrates strong performance in predicting the selected typical urban hazards, with area under the curve (AUC) values reaching 0.92, 0.92, and 0.94, respectively, but also, through the incorporation of the explainable model SHAP, visually presents the prediction process, the interrelations between evaluation factors, and the weight of each factor. Additionally, the study undertook a multi-hazard evaluation, producing a susceptibility zoning map for multiple hazards, while performing tailored analysis by integrating economic and population density factors of Hangzhou. This research enables urban decision makers to transcend the "black box" limitations of machine learning, facilitating informed decision making through strategic resource allocation and scheduling based on economic and demographic factors of the study area. This approach holds the potential to offer valuable insights for the sustainable development of cities worldwide.

关键词： Hangzhou city Multi-hazard risk assessment Machine learning Machine learning interpretability Socioeconomic analysis Urban sustainability development SUSTAINABLE URBAN-DEVELOPMENT SOCIAL VULNERABILITY SUBSIDENCE CHINA

Large eddy simulation study on drag reduction performance of array-based plasma synthetic jet actuators

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Chinese Journal of Aeronautics 2024年第10期37卷 118-135页

作者： yunan WANG Zhenbing LUO Wei XIE Yan ZHOU Qiang LIU Wenqiang PENG Yinxin ZHU College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China

Large Eddy Simulation(LES)is first used to investigate the drag reduction effect of an array-based configuration of Plasma Synthetic Jet Actuators(PSJAs)on a hemisphere in supersonic inflow,and analyze the effect of energy allocation and array angle on the drag reduction performance of opposing Plasma Synthetic Jet(PSJ)in this *** simulation results have been compared with experimental data,confirming the validity of the simulation *** results show that different energy allocations have a significant effect on the drag of the ***,the effect of the change in array angle on the drag of the hemisphere is not as noticeable as the effect caused by energy *** regions between the two PSJAs occur,which undermine the effectiveness of drag *** Turbulent Kinetic Energy(TKE)regions primarily concentrate on the core region of the jet and downstream of the bow *** influence of the array angle on TKE is most evident in the downstream region of the exits of the PSJs on both *** evolution of the coherent structures reveals that as the PSJ intensity decreases,the largescale vortices progressively break up into smaller-scale vortices,and energy is also transferred from large-scale structures to small-scale structures.

关键词： Plasma synthetic jet Shock wave Large eddy simulation Drag reduction Flow control

Bio-soft matter derived from traditional Chinese medicine:Characterizations of hierarchical structure,assembly mechanism,and beyond

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Journal of Pharmaceutical Analysis 2024年第6期14卷 823-839页

作者： Guiya Yang Yue Liu Yuying Hu Yue Yuan yunan Qin Quan Li Shuangcheng Ma School of Traditional Chinese Medicine Beijing University of Chinese MedicineBeijing102488China Institute for Control of Chinese Traditional Medicine and Ethnic Medicine National Institutes for Food and Drug ControlBeijing100050China Tianjin Key Laboratory of Therapeutic Substance of Traditional Chinese Medicine School of Chinese Materia MedicaTianjin University of Traditional Chinese MedicineTianjin301617China Collaborative Innovation Center for Advanced Organic Chemical Materials Co-constructed by the Province and Ministry Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional MoleculesCollege of Chemistry and Chemical EngineeringHubei UniversityWuhan430062China

Structural and functional explorations on bio-soft matter such as micelles,vesicles,nanoparticles,aggregates or polymers derived from traditional Chinese medicine(TCM)has emerged as a new topic in the field of *** discovery of such cross-scaled bio-soft matter may provide a unique perspective for unraveling the new effective material basis of TCM as well as developing innovative medicine and *** the rapid rise of TCM-derived bio-soft matter,their hierarchical structure and assembly mechanism must be unambiguously probed for a further in-depth understanding of their pharmacological *** this review,the current emerged TCM-derived bio-soft matter assembled from either small molecules or macromolecules is introduced,and particularly the unambiguous elucidation of their hierarchical structure and assembly mechanism with combined electron microscopic and spectroscopic techniques is *** pros and cons of each technique are also *** future challenges and perspective of TCM-derived bio-soft matter are outlined,particularly the requirement for their precise in situ structural determination is highlighted.

关键词： Electron microscopy Spectroscopy Traditional Chinese medicine Bio-soft matter Structural characterization

Constructing thermoresponsive PNIPAM-based microcarriers for cell culture and enzyme-free cell harvesting

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Chinese Chemical Letters 2024年第7期35卷 412-416页

作者： yunan Yuan Zhimin Luo Jie Chen Chaoliang He Kai Hao Huayu Tian CAS Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China College of Chemistry and Chemical Engineering Xiamen UniversityXiamen 361005China Jilin Biomedical Polymers Engineering Laboratory Changchun 130022China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361005China

The development of large-scale cell cultivation and non-invasive cell harvesting is highly desired in various fields,including biological regeneration and pharmaceutical *** using traditional microcarriers for cell culture,trypsinization is often necessary during cell collection,leading to partial cells *** this work,we developed a thermoresponsive glass microcarrier modified with poly(γ-propargyl-L-glutamate)(PPLG)and poly(N-isopropylacrylamide)(PNIPAM).We utilized these microcarriers for three-dimensional cell culture and enzyme-free cell harvesting,and the results indicated that the prepared microcarriers exhibited excellent non-invasive cell culture performance.

关键词： Microcarrier Temperature-responese PNIPAM Polymers Cell culture

Interactions of phenol and benzaldehyde in electrocatalytic upgrading process

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Chinese Chemical Letters 2024年第2期35卷 464-468页

作者： Lan Liang Chuanbin Wang Xukai Lu yunan Sun Beibei Yan Ning Li Guanyi Chen Li'an Hou School of Environmental Science and Engineering Tianjin Key Lab of Biomass/Wastes UtilizationTianjin UniversityTianjin 300350China School of Mechanical Engineering Tianjin University of CommerceTianjin 300134China Georgia Tech Shenzhen Institute Tianjin UniversityShenzhen 518071China High Tech Inst Beijing Beijing 100085China

Biomass pyrolysis oil can be improved effectively by electrocatalytic hydrogenation(ECH).However,the unclear interactions among different components lead to low bio-oil upgrading efficiency in the conversion ***,benzaldehyde and phenol,as common compounds in bio-oil,were chosen as model *** interactions between the two components were explored in the ECH process by combining experiments and theoretical *** showed that phenol could accelerate the conversion of benzaldehyde in the *** selectivity of benzyl alcohol was increased from 60.9%of unadded phenol to 99.1%with 30 mmol/L phenol concentration at 5 *** inhibited the ECH of *** the presence of benzaldehyde,the conversion rate of phenol was below 10.0%with no cyclohexanone and cyclohexanol formation at 5 *** density functional theory(DFT)calculations revealed that the phenol could promote the adsorption of benzaldehyde and facilitate the targeted conversion of benzaldehyde on the active site by lowering the reaction energy *** research on the interaction between phenol and benzaldehyde in the ECH provides a theoretical basis for the application of ECH in practical bio-oil upgrading.

关键词： Interaction Bio-oil Electrocatalytic hydrogenation Phenol Benzaldehyde

Data collection of wireless sensor network based on trajectory optimization of laser-charged UAV

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High-Confidence Computing

High-Confidence Computing 2024年第2期4卷 116-128页

作者： Chuanwen Luo Jian Zhang Jin Qian Yi Hong Zhibo Chen yunan Hou Xiujuan Zhang Yuqing Zhu School of Information Science and Technology Beijing Forestry UniversityBeijing 100083China Engineering Research Center for Forestry-Oriented Intelligent Information Processing of National Forestry and Grassland Administration Beijing 100083China College of Information Engineering Taizhou UniversityTaizhou 225300China School of Computer Science Qufu Normal UniversityRizhao 276826China Research Center of Applied Mathematics and Machine Intelligence Zhejiang LabHangzhou 311121China Department of Computer Science California State UniversityCA 90032USA

Unmanned Aerial Vehicle(UAV)can be used as wireless aerial mobile base station for collecting data from sensors in UAV-based Wireless Sensor Networks(WSNs),which is crucial for providing seamless services and improving the performance in the next generation wireless ***,since the UAV are powered by batteries with limited energy capacity,the UAV cannot complete data collection tasks of all sensors without energy replenishment when a large number of sensors are deployed over large monitoring *** overcome this problem,we study the Real-time Data Collection with Lasercharging UAV(RDCL)problem,where the UAV is utilized to collect data from a specified WSN and is recharged using Laser Beam Directors(LBDs).This problem aims to collect all sensory data from the WSN and transport it to the base station by optimizing the flight trajectory of UAV such that realtime data performance is ensured It has been proven that the RDCL problem is *** address this,we initially focus on studying two sub-problems,the Trajectory Optimization of UAV for Data Collection(TODC)problem and the Charging Trajectory Optimization of UAV(CTO)problem,whose objectives are to find the optimal flight plans of UAV in the data collection areas and charging areas,*** we propose an approximation algorithm to solve each of them with the constant ***,we present an approximation algorithm that utilizes the solutions obtained from TODC and CTO problems to address the RDCL ***,the proposed algorithm is verified by extensive simulations.

关键词： Wireless sensor networks Laser-charged UAV Trajectory optimization Data collection

Universal transfer of full-class metal electrodes for barrier-free two-dimensional semiconductor contacts

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InfoMat 2024年第1期6卷 96-107页

作者： Mengyu Hong Xiankun Zhang Yu Geng yunan Wang Xiaofu Wei Li Gao Huihui Yu Zhihong Cao Zheng Zhang Yue Zhang Academy for Advanced Interdisciplinary Science and Technology School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijingthe People's Republic of China Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of EducationUniversity of Science and Technology BeijingBeijingthe People's Republic of China

Metal–semiconductor contacts are crucial components in semiconductor *** two-dimensional transition-metal dichalcogenide semiconductors can sustain transistor scaling for next-generation integrated ***,their performance is often degraded by conventional metal deposition,which results in a high barrier due to chemical disorder and Fermi-level pinning(FLP).Although,transferring electrodes can address these issues,they are limited in achieving universal transfer of full-class metals due to strong adhesion between pre-deposited metals and ***,we propose a nanobelt-assisted transfer strategy that can avoid the adhesion limitation and enables the universal transfer of over 20 different types of *** contacts obey the Schottky–Mott rule and exhibit a FLP of S=*** the electron and hole contacts show record-low Schottky barriers of 4.2 and 11.2 meV,*** a demonstration,we construct a doping-free WSe_(2) inverter with these high-performance contacts,which exhibits a static power consumption of only 58 *** strategy provides a universal method of electrode preparation for building high-performance post-Moore electronic devices.

关键词： metal electrode transfer metal–semiconductor contacts Schottky barrier two-dimensional semiconductors

The Toxic Effects of Strong Chlorin Disinfectant on Mangroves and Emission Thresholds

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Open Journal of Ecology 2024年第2期14卷 114-124页

作者： yunan Yang Nan Zhou Xinyu Liu School of Space and Environment Beihang University Beijing China

In this study, based on the simulated discharge results of chemical disinfectants, hypocotyl germination concentration gradient pre-test and concentration gradient determination experiment were set up respectively. Laboratory cultivation was conducted to compare and analyze the root germination and germination indexes, three mangrove hypocotyls of Kandelia candel (Linn.) Druce, Ceriopstagal C.B. Rob. and Bruguiera sexangula var. Rhynchopetalas’ efficiency of cumulative root germination, cumulative germination and the cumulative expansion of the second pair of leaves, one-way analysis of variance was used to obtain the tolerance threshold of three mangrove hypocotyls to strong chlorin disinfectant. The study determined that the by-products of strong chlorin disinfectant, the toxic threshold concentrations of Kandelia candel (Linn.) Druce, Ceriopstagal C.B. Rob. and Bruguiera sexangula var. rhynchopetala are close to 0.55 mg/L, 0.55 mg/L and 0.25 mg/L, respectively. This concentration range is lower than the average concentration of 1.183 mg/L of active chlorine emitted from strong chlorine concentrate during pond clearing in high-level shrimp ponds, indicating that transient emissions of strong chlorine concentrate during pond clearing can have a toxic effect on mangrove plants. The strength of tolerance of the embryonic axes of the three mangrove species to effective chlorine contamination was, Ceriopstagal C.B. Rob. stronger than Bruguiera sexangula var. rhynchopetala, and Kandelia candel (Linn.) Druce is the weakest.

关键词： Strong Chlorin Toxicity Threshold Germination of Mangrove Hypocotyls One-Way Analysis of Variance