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Reconstructed index of summer monsoon dry-wet modes in East Asia for the last millennium

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Chinese Science Bulletin 2011年第28期56卷 3019-3027页

作者： QIAN WeiHong ZHU YaFen TANG shuaiqi Monsoon and Environment Research Group School of Physics Peking University Beijing 100871 China

Monthly precipitation datasets collected at 160 stations in China as well as the monthly winds and humidity data derived from the US National Centers for Environmental Prediction (NCEP) were used to construct the relationship between six summer dry-wet modes in eastern China and the summer monsoon airflow northward advance in East Asia. A millennial series of the monsoon dry-wet index (MDWI) was reconstructed based on Wang's six summer dry-wet modes in eastern China since 950 AD. A high (low) index indicates that the strong (weak) East Asian summer monsoon airflow can reach northern (southern) China and cause above (below) normal precipitation. Interdecadal periodic variations, such as the approximate 70-year oscillation, can be found in the MDWI series. In the last millennium, northern China has experienced persistent decadal wet periods and persistent decadal dry periods. At present, the MDWI is a low period on the interdecadal time scale so above-normal precipitation is observed in southern China and below-normal precipitation in northern China.

关键词：夏季季风干湿指数东亚中国北方地区月降水量中国模式重构中国东部地区

Ruin probability in Sparre Andersen risk model with claim inter-arrival times distributed as Erlang

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Frontiers of Mathematics in China 2015年第6期10卷 1433-1447页

作者： Guangkun SUN shuaiqi ZHANG Guoxin LIU School of Science Hebei University of Technology Tianjin 300401 China School of Economics and Commerce Guangdong University of Technology Guangzhou 510520 China Department of Mathematics Shijiazhuang Tiedao University Shijiazhuang 050043 China

This article deals with the ruin probability in a Sparre Andersen risk process with the inter-claim times being Erlang distributed in the framework of piecewise deterministic Markov process （PDMP）. We construct an exponential martingale by virtue of the extended generator of the PDMP to change the measure. Some results are derived for the ruin probabilities, such as the general expressions for ruin probability, Lundberg bounds, CramerLundberg approximations, and finite-horizon ruin probability.

关键词： Sparre Andersen risk model Erlang inter-claim times ruin probability Lundberg bound Cramer-Lundberg approximation

Optimal proportional reinsurance and investment problem with jump-diffusion risk process under effect of inside information

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Frontiers of Mathematics in China 2014年第4期9卷 965-982页

作者： Jie XIONG shuaiqi ZHANG Hui ZHAO Xihuan ZENG Department of Mathematics FST University of Macao Macao China School of Economics and Commerce Guangclong University of TechnologyGuangzhou 510520 China Department of Statistics Hebei University of Technology Tianjin 300401 China Department of Mathematics Tianjin University Tianjin 300072 China Institute of Business Administration University of Macao Macao China

We study optimal investment and proportional reinsurance strategy in the presence of inside information. The risk process is assumed to follow a compound Poisson process perturbed by a standard Brownian motion. The insurer is allowed to invest in a risk-free asset and a risky asset as well as to purchase proportional reinsurance. In addition, it has some extra information available from the beginning of the trading interval, thus introducing in this way inside information aspects to our model. We consider two optimization problems： the problem of maximizing the expected exponential utility of terminal wealth with and without inside information, respectively. By solving the corresponding Hamilton-Jacobi-Bellman equations, explicit expressions for their optimal value functions and the corresponding optimal strategies are obtained. Finally, we discuss the effects of parameters on the optimal strategy and the effect of the inside information by numerical simulations.

关键词： Inside information investment reinsurance jump diffusion

A dual plasmonic core-shell Pt/[TiN@TiO_(2)]catalyst for enhanced photothermal synergistic catalytic activity of VOCs abatement

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Nano Research 2022年第8期15卷 7071-7080页

作者： Anqi Li Qianpeng Zhang shuaiqi Zhao Yanan Chong Peng Wu Yifei Li Xiaojing Jin Guangxu Chen Yongcai Qiu Shihe yang Daiqi Ye Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control School of Environment and EnergySouth China University of TechnologyGuangzhou 510006China Department of Electronic and Computer Engineering The Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina Guangzhou HKUST Fok Ying Tung Research Institute NanshaGuangzhou 511458China State Key Laboratory of Luminescent Materials and Devices South China University of TechnologyGuangzhou 510640China Guangdong Key Lab of Nano-Micro Material Research School of Chemical Biology and Biotechnology Shenzhen Graduate SchoolPeking UniversityShenzhen 518055China

Volatile organic compounds(VOCs)are ubiquitous organic pollutants affecting atmospheric environment and human *** development of new efficient and environmentally friendly materials utilizing photothermal synergistic catalysis for purification of VOCs is still ***,we design and prepare a core–shell TiN@TiO_(2)nanostructure integrating with nanoscaled Pt(Pt/[TiN@TiO_(2)])by an attractive quenching *** strong light-harvesting capability of Pt and TiN components improve light-to-heat utilization efficiency by their intrinsic surface plasmon resonance *** TiO_(2)component upon the surface and the coexisting coupling effect of Pt0 and Pt2+enhance the photocatalytic effect of the *** a result,the catalytic performance is significantly improved with toluene(120 ppm)conversion of 100%under the gas hourly space velocity of 72,000 mL·g^(−1)·h^(−1)and light illumination of 500 mW·cm^(−2).The desired catalyst thus achieves highly efficient coupling effect of photocatalysis and light-to-heat conversion for promoting VOCs abatement.

关键词： core-shell Pt/[TiN@TiO_(2)]catalyst volatile organic compounds(VOCs)abatement photothermal synergistic catalysis full spectrum sunlight utilization

单轴作用下岩石的破坏行为及声发射响应特征研究

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煤 2025年第1期34卷 27-31,37页

作者：李东杰王帅旗曹阔山西晋城沁城煤业有限责任公司山西晋城048200 华北科技学院安全工程学院河北燕郊065201

为了研究受载状态下岩石的失稳变形规律和声发射响应特征,在单轴加载作用下,对标准岩石试件进行渐进破裂直至失稳全过程的实验研究,利用RMT-301岩石力学试验系统和DS5-8B全信息声发射仪记录岩石破坏力学参数和声发射响应特征参量,借助RF... 详细信息

为了研究受载状态下岩石的失稳变形规律和声发射响应特征,在单轴加载作用下,对标准岩石试件进行渐进破裂直至失稳全过程的实验研究,利用RMT-301岩石力学试验系统和DS5-8B全信息声发射仪记录岩石破坏力学参数和声发射响应特征参量,借助RFPA 2D系统实现了该过程的数值模拟研究。研究结果表明:声发射定位事件的数量演化特征可以反映岩石破坏损伤的程度,时空演化特征可以反映岩石的实际破坏过程;受载状态下,岩石破坏失稳过程中加载应力与声发射响应特征有很好的对应关系,应力突变(激增或骤减)时,声发射累计振铃计数和声发射累积能量均出现激增;声发射累计振铃计数和声发射累积能量激增,应力不一定突变;实验室试验和数值模拟二者结果相互对比验证,深入解释了岩石的破坏变形规律和声发射响应特征;基于声发射响应特征参量建立了声发射信号与损伤的定量模型,进一步揭示了岩石的破坏行为。研究结果为岩石损伤机理研究提供了一种思路,为其他岩土工程领域或相似问题领域提供了参考和借鉴。

关键词：单轴压缩失稳变形声发射 RFPA 数值模拟定量分析

Risk assessment of large-scale winter sports sites in the context of a natural disaster

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Journal of Safety Science and Resilience 2022年第3期3卷 263-276页

作者： Jiansong Wu Yuxuan Xing Yiping Bai Xiaofeng Hu shuaiqi Yuan School of Emergency Management and Safety Engineering China University of Mining and TechnologyBeijing 100083China School of Information Technology People’s Public Security University of ChinaBeijing 100038China Safety and Security Science Section Faculty of TechnologyPolicy and ManagementTU DelftDelft2628 BXthe Netherlands

Accidents induced by natural disasters at sports sites may cause catastrophic loss of great ***,previous studies on risk assessments of sports sites have only focused on operational risk and equipment *** the frequent occurrence of extreme disasters,the risk of domino chains caused by natural disasters at large-scale events,such as large-scale winter sports sites,cannot be *** this study,a natural disaster-induced accident-chain evolution analysis model(NAEA model)is *** on the results of the NAEA model,a fuzzy Bayesian network for domino accidents triggered by an earthquake at large-scale winter sports sites was *** sensitivity analysis and scenario analysis,it was found that fire and explosion accidents and crowded stampede accidents are the main causes of serious loss in domino disaster chains in large-scale sports ***,improving the early warning capability,reliability of electrical equipment,and automatic sprinkler systems are the most effective ways to prevent and control major *** addition,an optimal safety strategy improvement analysis was performed to facilitate the decision-making of safety managers to prevent serious accidents and reduce accident loss.

关键词： Risk assessment Domino disaster chain Large-scale sports sites Bayesian network Natural disaster Fuzzy logic

Engineering Two-Phase Bifunctional Oxygen Electrocatalysts with Tunable and Synergetic Components for Flexible Zn-Air Batteries

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Nano-Micro Letters 2021年第8期13卷 175-190页

作者： Yanli Niu Xue Teng shuaiqi Gong Mingze Xu Shi-Gang Sun Zuofeng Chen Shanghai Key Laboratory of Chemical Assessment and Sustainability School of Chemical Science and EngineeringTongji UniversityShanghai 200092People’s Republic of China State Key Lab of Physical Chemistry of Solid Surface College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005People’s Republic of China

Metal-air batteries,like Zn-air batteries(ZABs)are usually suffered from low energy conversion efficiency and poor cyclability caused by the sluggish OER and ORR at the air ***,a novel bimetallic Co/CoFe nanomaterial supported on nanoflower-like N-doped graphitic carbon(NC)was prepared through a strategy of coordination construction-cation exchange-pyrolysis and used as a highly efficient bifunctional oxygen *** characterizations and density functional theory calculations reveal the formation of Co/CoFe heterostructure and synergistic effect between metal layer and NC support,leading to improved electric conductivity,accelerated reaction kinetics,and optimized adsorption energy for intermediates of ORR and *** Co/CoFe@NC exhibits high bifunctional activities with a remarkably small potential gap of 0.70 V between the half-wave potential(E_(1/2))of ORR and the potential at 10 mA cm^(-2)(E_(j=10))of *** aqueous ZAB constructed using this air electrode exhibits a slight voltage loss of only 60 mV after 550-cycle test(360 h,15 days).A sodium polyacrylate(PANa)-based hydrogel electrolyte was synthesized with strong water-retention capability and high ionic *** quasi-solid-state ZAB by integrating the Co/CoFe@NC air electrode and PANa hydrogel electrolyte demonstrates excellent mechanical stability and cyclability under different bending states.

关键词： Bifunctional electrocatalysts Oxygen electrocatalysis Zn-air battery Co/CoFe heterointerface engineering Density functional theory calculations

Performance analysis of different coding schemes for wideband vehicle-to-vehicle MIMO systems

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The Journal of China Universities of Posts and Telecommunications 2023年第6期30卷 89-98页

作者： Liang Xiaolin Rong Zhanyi Cao Wangbin Liu shuaiqi Zhao Xiongwen College of Electronic and Information Engineering Hebei UniversityBaoding 071002China Hebei Key Laboratory of Power Internet of Things Technology North China Electric Power UniversityBaoding 071003China School of Electrical and Electronic Engineering North China Electric Power UniversityBaoding 071003China School of Electrical and Electronic Engineering North China Electric Power UniversityBeijing 102206China

The signal is subjected to lots of interferences in vehicle-to-vehicle(V2V)channel propagation,resulting in receiving error ***-dimensional(2D)and three-dimensional(3D)geometrical channel models are used to depict the wideband V2V multiple-input multiple-output(MIMO)*** the channel model,Turbo code and low-density parity-check(LDPC)code are investigated for wideband V2V MIMO system,and the encoding and the decoding schemes are *** bit error rate(BER),channel capacity and outage probability of wideband V2V MIMO system using Turbo code and LDPC code are analyzed at different typical *** results show that the performance of wideband V2V MIMO system using Turbo code outperform that using LDPC *** performance is affected by transmitting and receiving speeds with the same coding *** the channel capacity of the 3D channel is larger than that of 2D channel.

关键词： geometrical channel models Turbo code low-density parity-check(LDPC)code vehicle-to-vehicle(V2V)communication wideband channels

High-capacity Bi_(2)O_(3) anode for 2.4 V neutral aqueous sodium-ion battery-supercapacitor hybrid device through phase conversion mechanism

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Journal of Energy Chemistry 2022年第2期31卷 605-615页

作者： Mingze Xu Yanli Niu Xue Teng shuaiqi Gong Lvlv Ji Zuofeng Chen Shanghai Key Lab of Chemical Assessment and Sustainability School of Chemical Science and EngineeringTongji UniversityShanghai 200092China School of Materials Science and Engineering Zhejiang Sci-Tech UniversityHangzhou 310018ZhejiangChina

Aqueous battery-supercapacitor hybrid devices(BSHs)are of great importance to enrich electrochemical energy storage systems with both high energy and power ***,further improvement of BSHs in aqueous electrolytes is greatly hampered by operating voltage and capacity *** from the conventional intercalation/de-intercalation mechanism,Bi_(2)O_(3) implements charge storage by a reversible phase conversion ***,taking Bi_(2)O_(3) electrode with wide potential window(from-1.2 to 1 V *** calomel electrode)and high capacity as battery-type anode,we propose that the overall performance of aqueous BSHs can be greatly upgraded under neutral *** paring with stable layer-structuredδ-MnO_(2) cathode,a sodium-ion Bi_(2)O_(3)//MnO_(2) BSH with an ultrahigh voltage of 2.4 V in neutral sodium sulfate electrolyte is developed for the first *** hybrid device exhibits high capacity(~215 C g^(-1) at 1 mA cm^(-2)),relatively long lifespan(~77.2%capacity retention after 1500 cycles),remarkable energy density(71.7 Wh kg^(-1)@400.5 W kg^(-1))and power density(3204.3 W kg^(-1)@18.8 Wh kg^(-1)).Electrochemical measurements combining a set of spectroscopic techniques reveal the reversible phase conversion between bismuth oxide and metallic bismuth(Bi_(2)O_(3)?Bi0)through Bi^(2+) transition phase in neutral sodium sulfate solution,which can deliver multielectron transfer up to 6,leading to the high-energy *** work sheds light on the feasibility of using Bi_(2)O_(3) electrode under neutral condition to address the issue of narrow voltage and low capacity for aqueous BSHs.

关键词： Bismuth oxide Phase conversion High voltage High capacity Battery-supercapacitor hybrid devices