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Wave interaction for a generalized higher-dimensional boussinesq equation describing the nonlinear Rossby waves

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Journal of Oceanology and Limnology 2024年第5期42卷 1415-1424页

作者： rong su Penghao JI Xiaojun YIN College of Science Inner Mongolia Agricultural UniversityHohhot 010018China

Based on an algebraically Rossby solitary waves evolution model,namely an extended(2+1)-dimensional boussinesq equation,we firstly introduced a special transformation and utilized the Hirota method,which enable us to obtain multi-complexiton solutions and explore the interaction among the *** wave functions are then employed to infer the influence of background flow on the propagation of Rossby waves,as well as the characteristics of propagation in multi-wave running ***,we generated stereogram drawings and projection figures to visually represent these *** dynamical behavior of these solutions is thoroughly examined through analytical and graphical ***,we investigated the influence of the generalized beta effect and the Coriolis parameter on the evolution of Rossby waves.

关键词： Rossby wave boussinesq equation Complexiton solution Breather solution

Numerical Simulation of Droplet Generation in Coaxial Microchannels

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Fluid Dynamics & Materials Processing 2024年第3期20卷 487-504页

作者： Zongjun Yin rong su Hui Xu School of Mechanical Engineering Anhui Institute of Information TechnologyWuhu241100China

In this study,numerical simulations of the pinching-off phenomena displayed by the dispersed phase in a continuous phase have been conducted using COMSOL Multiphysics(level-set method).Four flow patterns,namely“drop flow”,“jet flow”,“squeeze flow”,and“co-flow”,have been obtained for different flow velocity ratios,channel diameter ratios,density ratios,viscosity ratios,and surface *** flow pattern map of two-phase flow in coaxial microchannels has been obtained accordingly,and the associated droplet generation process has been critically discussed considering the related frequency,diameter,and pinch-off *** particular,it is shown that the larger the flow velocity ratio,the smaller the diameter of generated droplets and the shorter the pinch-off *** pinch-off length of a droplet is influenced by the channel diameter ratio and density *** changes in viscosity ratio have a negligible influence on the droplet generation pinching *** an increase in surface tension,the frequency of generation and pinch-off length of droplets decrease,but for small surface tension the generation diameter of droplet increases.

关键词： Droplet generation characteristics coaxial microchannels flow patterns pinch-off length

Identification of high oxygen-consuming substances in stormwater drainage systems illicitly connected with sewage system

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Journal of Environmental Sciences 2024年第4期138卷 132-140页

作者： Chen Xu Zuxin Xu Wenhai Chu Shanshan Wu rong Xiao Lei su State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China Ministry of Education Key Laboratory of Yangtze River Water Environment Tongji UniversityShanghai 200092China Guangzhou Resource Environmental Protection Technology Co. Ltd.Guangzhou 510030China

The dissolved oxygen content in water is an important indicator for assessing the quality of the water environment,and maintaining a certain amount of dissolved oxygen is essential for the healthy development of the ecological *** a water body is anoxic,the activity of anaerobic microorganisms increases and organic matter is decomposed to produce a large number of blackening and odorizing substances,resulting in black and odorous water bodies,which is a very common and typical phenomenon in ***,there is still a relatively universal occurrence of illicitly connected stormwater and sewage pipes in the urban drainage pipe network in China,which makes oxygen-consuming substances be directly discharged into rivers through stormwater pipes and consume the dissolved oxygen in the water bodies,resulting in an oxygen deficiency of the *** induces seasonal or year-round black and stink phenomena in urban ***,identifying high oxygen-consuming substances,which lays the foundation for the subsequent removal of oxygen-consuming substances,is *** a series of comparisons of water quality indicators and analysis of organic characteristics,it was found that the oxygen consumption capacity of domestic sewage was higher than that of industrial wastewater in the selected area of this study,and the oxygen-consuming substances of domestic sewage were small molecular amino *** comparing 20 conventional free amino acids,it was found that seven of them consumed oxygen easily,and compared with chemical oxygen consumption,biological oxygen consumption was in a leading position.

关键词： Urban drainage system Oxygen-consuming substances Domestic sewage Amino acid

Temporal and Spatial Trends in HIV Positivity Rate for VCT Clinics—China,2015–2022

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China CDC weekly 2024年第1期6卷 6-11页

作者： Yi Liu rong su Dongmin Li Shaorong Wang Mengjie Han National Center for AIDS/STD Control and Prevention Chinese Center for Disease Control and PreventionBeijingChina

Introduction:Human immunodeficiency virus(HIV)voluntary counseling and testing(VCT)clinics play a critical role in identifying and diagnosing HIV *** study aimed to describe the trend of HIV positivity rate(HPR)among Chinese VCT clinics between 2015 and ***:This study utilized data from the China Information System for Disease Control and Prevention to analyze the trend in the HPR for VCT clinics from 2015 to *** HPR was calculated by dividing the number of newly-reported HIV cases by the number of HIV tests,multiplied by 100%.To identify temporal and spatial trends in the HPR,we employed joinpoint regression analysis and the Getis-Ord hotspot ***:From 2015 to 2022,VCT clinics in China performed a total of 22,075,386 HIV tests,leading to the identification of 260,353 HIV cases,resulting in a HPR of 1.18%.The HPR consistently declined over the study period,with an average annual percent change(AAPC)of−7.5%(95%confidence interval:−12.6%,−2.2%,P<0.05).The number of HPR hotspots also decreased from 41 in 2015 to 23 in *** HPR hotspots were primarily located in Yunnan,Sichuan,Guangdong,and Guangxi provincial-level administrative divisions(PLADs).Among the 31 PLADs,16 showed a significant decrease in HPR during the study period(AAPC<0,PAAPC<0.05).Conclusions:VCT clinics in China have played a significant role in identifying HIV *** declining HPR observed in these clinics may indicates the progress has been made in some degree in mitigating HIV among high-risk ***,it is crucial to further improving the utilization of VCT clinics for HIV testing.

关键词： VCT dividing Spatial

Controllable Ring-opening Polymerization ofδ-Valerolactone Catalyzed by Quinolinyl-Urea/MTBD Systems

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Chinese Journal of Polymer Science 2024年第8期42卷 1103-1110页

作者： Xin-Yu Liu Liang Zhu su-Yun Jie bo-Geng Li State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310058China

Due to their excellent biocompatibility and biodegradability,aliphatic polyesters are widely used in the biomedical,packaging and agricultural fields,which are usually accessed by the ring-opening polymerization(ROP)of lactones and the catalysts particularly play an important *** a series of quinolinyl-urea catalysts have been synthesized via the reaction between isocyanate and aminoquinoline with an amino group at different substitution positions and *** combination with 7-methyl-1,5,7-triazabicyclo[4,4,0]dec-5-ene(MTBD)as a cocatalyst and benzyl alcohol(BnOH)as an initiator,1-(3,5-bis(trifluoromethyl)phenyl)-3-(quinolin-3-yl)urea(3-QU)was observed to be most active for the ROP ofδ-valerolactone(δ-VL).The polymerization conditions were optimized by varying the type of organic base,catalyst concentration and reaction *** changing the ratio of[M]_0/[I],linear polyvalerolactones(PVLs)with different molecular weights and narrow molecular weight distribution were *** kinetic and chain extension experiments were carried out to prove the"living"/controllable *** the NMR experiments were used to support the proposal of possible mechanism.

关键词： Quinolinyl-urea Ring-opening polymerization PVL

Steam disinfection enhances bioaccessibility of metallic nanoparticles in nano-enabled silicone-rubber baby bottle teats,pacifiers,and teethers

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Journal of Environmental Sciences 2024年第2期136卷 161-171页

作者： Yu su BinWang Xin Tong Shuchuan Peng Sijin Liu Baoshan Xing rong Ji State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China School of Resources and Environmental Engineering Hefei University of TechnologyHefei 230009China State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Stockbridge School of Agriculture University of MassachusettsAmherstMA 01003USA

Nano-enabled silicone-rubber articles for feeding or chewing could be a source of metallic nanoparticles(NPs)directly exposed to infants and young ***,the impact of steam disinfection on release of NPs and the related potential risks to children's health are ***,we investigated contents and form of Ag and Zn in 57 nano-enabled silicone-rubber baby bottle teats,pacifiers,and teethers of seven countries and examined the impacts of steam disinfection on in vitro bioaccessibility(IVBA)of Ag and Zn in the *** 89%articles had a mixture of Ag-and Zn-containing NPs and the teethers had relatively high Ag and Zn contents(up to 501 and 254μg/g,respectively).Steam disinfection caused rubber decomposition into micro(nano)plastics(0.54-15.7μm)and NP release from the interior of bulk rubber and micro-sized plastics,thus enhancing the IVBA of Ag and Zn by up to 5.5 *** findings provide insights into mechanisms for NP release by steam *** oral exposure risk assessment suggested low health concerns on individual metal release,our study points out the need to assess the potential health risks of child co-exposure to metallic NPs and micro(nano)plastics.

关键词： Silicone rubber Metallic nanoparticles Micro(nano)plastics Bioaccessibility Children's health

Understanding adversarial attacks on observations in deep reinforcement learning

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Science China(Information Sciences) 2024年第5期67卷 69-83页

作者： You QIAOBEN Chengyang YING Xinning ZHOU Hang su Jun ZHU bo ZHANG Department of Computer Science and Technology Beijing National Research Center for Information Science and Technology Tsinghua-Bosch Joint Center for Machine Learning Institute for Artificial Intelligence Tsinghua University Peng Cheng Laboratory

Deep reinforcement learning models are vulnerable to adversarial attacks that can decrease the cumulative expected reward of a victim by manipulating its observations. Despite the efficiency of previous optimization-based methods for generating adversarial noise in supervised learning, such methods might not achieve the lowest cumulative reward since they do not generally explore the environmental ***, a framework is provided to better understand the existing methods by reformulating the problem of adversarial attacks on reinforcement learning in the function space. The reformulation approach adopted herein generates an optimal adversary in the function space of targeted attacks, repelling them via a generic two-stage framework. In the first stage, a deceptive policy is trained by hacking the environment and discovering a set of trajectories routing to the lowest reward or the worst-case performance. Next, the adversary misleads the victim to imitate the deceptive policy by perturbing the observations. Compared to existing approaches, it is theoretically shown that our adversary is strong under an appropriate noise level. Extensive experiments demonstrate the superiority of the proposed method in terms of efficiency and effectiveness, achieving state-of-the-art performance in both Atari and MuJoCo environments.

关键词： deep learning reinforcement learning adversarial robustness adversarial attack

Preparation of CIP@TiO_(2) composite with broadband electromagnetic wave absorption properties

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 197-205页

作者： Qiang su Hanqun Wang Yunfei He Dongdong Liu Xiaoxiao Huang bo Zhong School of Materials Science and Engineering Harbin Institute of TechnologyWeihaiWeihai 264209China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China

Scholars aim for the improved impedance matching (Z) of materials while maintaining their excellent wave absorption properties. Based on the hydrolysis characteristics of isopropyl titanate, a simple preparation process for the coating of carbonyl iron powder(CIP) with TiO_(2) was designed. Given the TiO2coating, the Z of the CIP@TiO_(2) composite was adjusted well by decreasing the dielectric constant. Moreover, the interfacial polarization of CIP@TiO_(2) was enhanced. Ultimately, the electromagnetic-wave (EMW) absorption property of the CIP@TiO_(2)composite was improved substantially, the minimum reflection loss reached-46.07 dB, and the effective absorption bandwidth can reach 8 GHz at the composite thickness of 1.5 mm. Moreover, compared with CIP, the oxidation resistance of CIP@TiO_(2)showed remarkable improvement. The results revealed that the oxidation starting temperature of CIP@TiO_(2) as about 400℃,whereas the uncoated CIP had an oxidation starting temperature of approximately 250℃. Moreover, the largest oxidation rate temperature of CIP@TiO_(2) increased to around 550℃. This work opens up a novel strategy for the production of high-performance EMW absorbers via structural design.

关键词： carbonyl iron@titanium dioxide electromagnetic-wave absorption impedance matching oxidation resistance

Machine learning and neural network supported state of health simulation and forecasting model for lithium-ion battery

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Frontiers in Energy 2024年第2期18卷 223-240页

作者： Nan QI Kang YAN Yajuan YU Rui LI rong HUANG Lai CHEN Yuefeng su Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China Department of Energy and Environmental Materials School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing Electric Vehicle Co. Ltd.Beijing 100176China

As the intersection of disciplines deepens,the field of battery modeling is increasingly employing various artificial intelligence(AI)approaches to improve the efficiency of battery management and enhance the stability and reliability of battery *** paper reviews the value of AI methods in lithium-ion battery health management and in particular analyses the application of machine learning(ML),one of the many branches of AI,to lithium-ion battery state of health(SOH),focusing on the advantages and strengths of neural network(NN)methods in ML for lithium-ion battery SOH simulation and *** is one of the important branches of ML,in which the application of NNs such as backpropagation NN,convolutional NN,and long short-term memory NN in SOH estimation of lithium-ion batteries has received wide *** so far have shown that the utilization of NN to model the SOH of lithium-ion batteries has the advantages of high efficiency,low energy consumption,high robustness,and scalable *** the future,NN can make a greater contribution to lithium-ion battery management by,first,utilizing more field data to play a more practical role in health feature screening and model building,and second,by enhancing the intelligent screening and combination of battery parameters to characterize the actual lithium-ion battery SOH to a greater *** in-depth application of NN in lithium-ion battery SOH will certainly further enhance the science,reliability,stability,and robustness of lithium-ion battery management.

关键词： machine learning lithium-ion battery state of health neural network artificial intelligence