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Single-atom Fe-N_(5)catalyst for high-performance zinc-air batteries

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Nano Research 2022年第9期15卷 8056-8064页

作者： Le Li yin-Juan Chen hao-Ran xing Na Li Jia-Wei Xia xing-Yue Qian Hui Xu Wei-Zuo Li Feng-Xiang yin Guang-Yu He Hai-Qun Chen Key Laboratory of Advanced Catalytic Materials and Technology Advanced Catalysis and Green Manufacturing Collaborative Innovation CenterSchool of Petrochemical EngineeringChangzhou UniversityChangzhou 213164China

Developing innovative and efficient non-precious-metal-group(non-PMG)electrocatalysts is crucial for the wide use of zinc-air batteries(ZABs).Herein,a single-atom catalyst(termed as Fe-N-C/rGO SAC)with unique five N-coordinated Fe(Fe-N_(5))centers is prepared by pyrolyzing the composite of zeolitic-imidazolate-frameworks-8(ZIF-8)and graphene oxide(GO).Specifically,the individual Fe site is stabilized by four equatorial and one axial N atoms donated by the N-doped carbon matrix and imidazole ring,respectively,thus forming an asymmetric electron depletion zone over the metal center,which can effectively promote the generation of reactive intermediates and accelerate the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)processes for *** rechargeable liquid ZAB with Fe-N-C/rGO catalyst exhibits an extremely high energy density(928.25 Wh·kg^(−1)),a remarkable peak power density(107.12 mW·cm^(−2)),and a long cycle life(400 h).Additionally,the corresponding flexible solid-state ZAB displays superior foldability and remarkable cycling *** work provides both experimental and theoretical guidance for rational design of non-PMG electrocatalyst-driven ZABs.

关键词： N-doped hierarchical porous carbon/rGO composite single-atom electrocatalyst five N-coordinated Fe(Fe-N_(5))singleatom sites zinc-air battery density functional theory(DFT)study

Molecular dynamics study on microscale residual stress of graphene/aluminum nanocomposites by selective laser sintering

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Rare Metals 2022年第11期41卷 3677-3683页

作者： xing-Nan hao Xia Liu Department of Engineering Mechanics Beijing University of TechnologyBeijing100124China

The fabrication of graphene/metal matrix composites by selective laser sintering(SLS)technique has been extensively studied;however,the complex micros truc ture and residual stress limit their further ***,the sinterin... 详细信息

关键词： stress residual composites

Cyclic-Auto-Correlation Based Timing Estimation Algorithm for Time-Frequency Overlapping Multi-Carrier Signals

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Journal of Electronic Science and Technology 2020年第3期18卷 223-233页

作者： xing Zhang Jian-hao Hu National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of ChinaChengdu 610054

In recent years,the time-frequency overlapping multi-carrier signal has been a novel and valuable topic in blind signal processing,especially in the non-cooperative receiving *** there is little related research in public published *** paper proposes two timing estimation algorithms,which are non-data-aided and based on the cyclic auto-correlation *** order to evaluate the performance of the proposed algorithms,the theoretical bound of the timing estimation is *** to the analyses and simulation results,the effectiveness of the proposed algorithms has been *** shows that MethodⅠhas better performance than MethodⅡ.However,MethodⅡdoes not need prior information,so it has a wider range of applications.

关键词： Cyclic auto-correlation orthogonal frequency division multiplexing(OFDM) time-frequency overlapping signal timing estimation

The Increasing Role of Synergistic Effects in Carbon Mitigation and Air Quality Improvement, and Its Associated Health Benefits in China

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Engineering 2023年第1期20卷 103-111页

作者： Jie Wang Xi Lu Pengfei Du haotian Zheng Zhaoxin Dong Zihua yin Jia xing Shuxiao Wang Jiming hao State Key Joint Laboratory of Environment Simulation and Pollution Control School of the EnvironmentTsinghua UniversityBeijing 100084China Institute for Carbon Neutrality Tsinghua UniversityBeijing 100084China Beijing Laboratory of Environmental Frontier Technologies Tsinghua UniversityBeijing 100084China State Environmental Protection Key Laboratory of the Sources and Control of Air Pollution Complex Beijing 100084China

A synergistic pathway is regarded as a critical measure for tackling the intertwined challenges of climate change and air pollution in China. However, there is as yet no indicator that can comprehensively reflect such synergistic effects;hence, existing studies lack a consistent framework for comparison. Here, we introduce a new synergistic indicator defined as the pollutant generation per gross domestic product (GDP) and adopt an integrated analysis framework by linking the logarithmic mean Divisia index (LMDI) method, response surface model (RSM), and global exposure mortality model (GEMM) to evaluate the synergistic effects of carbon mitigation on both air pollutant reduction and public health in China. The results show that synergistic effects played an increasingly important role in the emissions mitigation of SO_(2), NOx, and primary particulate matter with an aerodynamic diameter no greater than 2.5 μm (PM2.5), and the synergistic mitigation of pollutants respectively increase from 3.1, 1.4, and 0.3 Mt during the 11th Five-Year Plan (FYP) (2006–2010) to 5.6, 3.7, and 1.9 Mt during the 12th FYP (2011–2015). Against the non-control scenario, synergistic effects alone contributed to a 15% reduction in annual mean PM2.5 concentration, resulting in the prevention of 0.29 million (95% confidential interval: 0.28–0.30) PM2.5-attributable excess deaths in 2015. Synergistic benefits to air quality improvement and public health were remarkable in the developed and population-dense eastern provinces and municipalities. With the processes of urbanization and carbon neutrality in the future, synergistic effects are expected to continue to increase. Realizing climate targets in advance in developed regions would concurrently bring strong synergistic effects to air quality and public health.

关键词： Synergistic effects Indicator Carbon mitigation Air pollution control Spatial and temporal disparities

Defined Contribution Pension Planning with the Return of Premiums Clauses and HARA Preference in Stochastic Environments

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Acta Mathematicae Applicatae Sinica 2023年第2期39卷 396-423页

作者： hao CHANG xing-jiang CHEN School of Mathematical Sciences Tiangong UniversityTianjin 300387China Department of Mathematical Sciences School of EngineeringComputer and Mathematical SciencesAuckland University of TechnologyAucklandNew Zealand

This paper studies a defined contribution(DC)pension fund investment problem with return of premiums clauses in a stochastic interest rate and stochastic volatility *** practice,most of pension plans were subject to the return of premiums clauses to protect the rights of pension members who died before *** the mathematical modeling,we assume that a part of pension members could withdraw their premiums if they died before retirement and surviving members could equally share the difference between accumulated contributions and returned *** suppose that the financial market consists of a risk-free asset,a stock,and a zero-coupon *** interest rate is driven by a stochastic affine interest rate model and the stock price follows the Heston’s stochastic volatility model with stochastic interest *** fund managers have different risk preferences,and the hyperbolic absolute risk aversion(HARA)utility function is a general one including a power utility,an exponential utility,and a logarithm utility as special *** are concerned with an optimal portfolio to maximize the expected utility of terminal wealth by choosing the HARA utility function in the *** using the principle of dynamic programming and Legendre transform-dual theory,we obtain explicit solutions of optimal *** special cases are also derived in ***,a numerical simulation is provided to illustrate our results.

关键词： defined contribution pension plan return of premiums clauses stochastic interest rate HARA preference Legendre transform-dual theory stochastic optimal control

Cleaning space debris with a space-based laser system

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Chinese Journal of Aeronautics 2014年第4期27卷 805-811页

作者： Shen Shuangyan Jin xing Chang hao State Key Laboratory of Laser Propulsion Equipment Academy

High-energy pulsed laser radiation may be the most feasible means to mitigate the threat of collision of a space station or other valuable space assets with orbital debris in the size range of 1–10 cm. Under laser irradiation, part of the debris material is ablated and provides an impulse to the debris particle. Proper direction of the impulse vector either deflects the object trajectory or forces the debris on a trajectory through the upper atmosphere, where it burns up. Most research concentrates on ground-based laser systems but pays little attention to space-based laser *** are drawbacks of a ground-based laser system in cleaning space debris. Therefore the placement of a laser system in space is proposed and investigated. Under assumed conditions,the elimination process of space debris is analyzed. Several factors such as laser repetition frequency, relative movement between the laser and debris, and inclination of debris particles which may exercise influence to the elimination effects are discussed. A project of a space-based laser system is proposed according to the numerical results of a computer study. The proposed laser system can eliminate debris of 1–10 cm and succeed in protecting a space station.

关键词： Laser ablation Laser system Orbital transfer Space-based Space debris

Effect of sub-acute exposure to TiO_2 nanoparticles on oxidative stress and histopathological changes in Juvenile Carp (Cyprinus carpio)

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Journal of Environmental Sciences 2009年第10期21卷 1459-1466页

作者： hao Linhua WANG Zhenyu xing Baoshan College of Environmentul Science and Engineering Ocean University of China Qingdao 266100 China. First Institute of Oceanography State Oceanic Administration Qingdao 266061 China. Department of Plant Soil and Insect Sciences University of Massachusetts Amherst MA 01003 USA.

Increasing application of nanotechnology highlights the need to clarify and understand nanotoxicity. Mammalian and in vitro studies have raised concerns about the toxicity of titanium dioxide nanoparticles （TiO2-NPs）, but there are limited data on ecotoxicity to aquatic organisms. In this work, the sub-acute toxicity of TiO2-NPs to carp （Cyprinus carpio） was assessed. Superoxide dismutase （SOD）, catalase （CAT） and peroxidase （POD） activities and lipid peroxidation （LPO） levels in liver, gill and brain tissues of carps varied with concentration of TiO2-NPs suspensions and exposure time （up to 8 d）. As a result, 100 and 200 mg/L TiO2-NPs caused statistically significant decrease in SOD, CAT and POD activities and significant increase in LPO levels in tissues （P 〈 0.05）, suggesting that the fish exposed to these two concentrations of TiO2-NPs suffered from the oxidative stress. The extent of depletion of antioxidant enzymes activities and the elevation of LPO in the liver was the greatest, indicating that the liver might be the most susceptible organ to TiO2-NPs exposure. In addition, carps had gill pathologies including edema and thickening of gill lamellae as well as gill filaments, and liver pathologies including necrotic and apoptosis hepatocytes after exposed to 100 and 200 mg/L TiO2-NPs for 20 d. These results indicated a potential risk from TiO2-NPs released into the aqueous environment.

关键词： TiO2 nanoparticles carp sub-acute toxicity oxidative stress histopathology

Development and prospect of near-infrared spectroscopy-assisted schizophrenia diagnosis based on bibliometrics

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World Journal of Psychiatry 2025年第1期15卷 7-11页

作者： Yan Zhang hao-Yu xing Juan Yan Administration Office Lishui Second People’s HospitalLishui 323060Zhejiang ProvinceChina Department of Medical Engineering The Affiliated Mental Health Center&Hangzhou Seventh People's HospitalZhejiang University School of MedicineHangzhou 310013Zhejiang ProvinceChina Quality Control Office The Affiliated Mental Health Center&Hangzhou Seventh People's HospitalZhejiang University School of MedicineHangzhou 310013Zhejiang ProvinceChina

In this editorial,we comment on the recent article by Fei et al exploring the field of near-infrared spectroscopy(NIRS)research in schizophrenia from a bibliometrics *** recent years,NIRS has shown unique advantages in the auxiliary diagnosis of schizophrenia,and the introduction of bibliometrics has provided a macro perspective for research in this *** the opportunities brought about by these technological developments,remaining challenges require multidi-sciplinary approach to devise a reliable and accurate diagnosis system for ***,NIRS-assisted technology is expected to contribute to the division of methods for early intervention and treatment of schizophrenia.

关键词： Bibliometrics Schizophrenia Near-infrared spectroscopy Diagnostic technique Data analysis

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 *** a kernel order assignment manner in OFD scenario,order recommendation directly influences the delivery efficiency of the platform and the delivery experience of *** paper addresses the dynamism of the order recommendation problem and proposes a reinforcement learning solution *** actor-critic network based on long short term memory(LSTM)unit is designed to deal with the order-grabbing conflict between different ***,three rider sequencing rules are accordingly proposed to match different time steps of the LSTM unit with different *** test the performance of the proposed method,extensive experiments are conducted based on real data from Meituan delivery *** 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