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Coupled conditional nonlinear optimal perturbations and their application to ENSO ensemble forecasts

Science China Earth Sciences 2024年第3期67卷 826-842页

作者： Wansuo DUAN Lei HU rong FENG LASG Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

Limitations are existed in current ensemble forecasting initial perturbation methods for describing the interactions among various spheres of the Earth system. In this study, a new method is proposed, namely, the coupled conditional nonlinear optimal perturbation(C-CNOP) method, which incorporates multisphere interactions much appropriately. The El Nino-Southern Oscillation(ENSO) is a typical ocean-atmosphere “coupling”(or “interaction”) phenomenon. The C-CNOP method is applied to ensemble forecasting of ENSO. It is demonstrated that the C-CNOP method can generate coupled initial perturbations(CPs) that appropriately consider initial ocean-atmosphere coupling uncertainty for ENSO ensemble forecasts. Results reveal that the CPs effectively improve the ability of ENSO ensemble-mean forecasts in both temporal variability of Nio3.4 sea surface temperature anomalies(SSTAs) and spatial variability of ENSO mature-phase SSTAs. Notably, despite the weakest ocean-atmosphere coupling strength in the tropical Pacific occurring during the boreal spring and summer, CPs still capture the uncertainties of this weak coupling when ENSO predictions are initialized at these seasons. This performance of CPs significantly suppresses the rapid increase of ENSO prediction errors due to the high ocean-atmosphere coupling instability during these seasons, and thus effectively extends the lead time of skillful ENSO forecasting. hence, the C-CNOP method is a suitable initial perturbation approach for ENSO ensemble forecast that can describe initial ocean-atmosphere coupling uncertainty. It is expected that the CCNOP method plays a significant role in predictions of other high-impact climate phenomena, and even future Earth system predictions.

关键词： Ensemble forecast Multisphere interaction Initial perturbations ENSO

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A passive sampler for synchronously measuring inorganic and organic pollutants in sediment porewater:Configuration and field application

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Journal of Environmental Sciences 2024年第2期136卷 201-212页

作者： Pei Lei Mingying Chen Nan rong Wenzhong Tang Hong Zhang School of Environment Nanjing Normal UniversityNanjing 210023China State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China South China Institute of Environmental Sciences Ministry of Ecology and EnvironmentGuangzhou 510530China State Environmental Protection Key Laboratory of Water Environmental Simulation and Pollution Control Guangzhou 510530China University of Chinese Academy of Sciences Beijing 100049China

In situ measurement of multiple pollutants coexisting in sediment porewater is an essential step in comprehensively assessing the bioavailability and risk of pollutants,but to date,this needs to be better developed.In this study,a passive sampler,consisting of an“I-shaped”supporting frame and inorganic/organic sampling units,incorporating equilibrium dialysis theory and kinetic/equilibrium sorption principle,was developed for the synchronous measurement of inorganic(e.g.,phosphorus and metal(loid)s)and organic pollutants(e.g.,parent and substituted PAHs).The equilibrium time and sampling rates were explored in laboratory tests to support in situ application.Profiles of pollutants in porewater within a vertical resolution of centimeters,i.e.,1 cm and 2 cm for inorganic and organic pollutants,respectively,were obtained by field deployment of the sampler for further estimation of diffusive fluxes across the sediment-water interface.The results suggested that the role of sediments for a specific pollutant may change(e.g.,from“sink”to“source”)during the sampling time.This study demonstrated the feasibility of synchronous measurement of inorganic and organic pollutants in sediment porewater by the passive sampler.In addition,it provided new insight for further investigation into the combined pollution effects of various pollutants in sediments.

关键词： Passive sampling Bioavailability Polycyclic aromatic hydrocarbons Combined pollution Diffusive flux

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Visible-Light-Driven Four-Component Radical Relay Aminocarbonylation of Unactivated Alkenes

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Chinese Journal of Chemistry 2024年第9期42卷 990-996页

作者： Bin Lu Feng-Shuo Bao Zi-Wei he Wen-Jing Xiao Jia-rong Chen Engineering Research Center of Photoenergy Utilization for Pollution Control and Carbon Reduction College of ChemistryCentralChina Normal University152 LuoyuRoadWuhanHubei 430079China Wuhan Institute of Photochemistry and Technology 7North Bingang RoadWuhanHubei 430083China Key Laboratory of Organo-Pharmaceutical Chemistry of Jiangxi Province Gannan Normal UniversityGanzhouJiangxi 341000China

Catalytic four-component radical carbonylation of unactivated alkenes has recently been recognized as a robust protocol for rapid construction of various structurally diverse carbonyl compounds.Given the significance of fluorine-containing groups,this reaction class has been extensively applied to assembly of a variety of perfluoroalkyl carboxylic acid derivatives by transition metal catalysis.herein,we report a visible-light-driven radical relay 1,2-perfluoroalkylation aminocarbonylation of unactivated alkenes using CO gas as carbonyl source and 4CzIPN as organic photocatalyst.A wide range of alkenes and amines were well tolerated,providing the valuableβ-perfluoroalkylated amides with generally good yields and high chemoselectivity.

关键词： Visible light Photoredox catalysis Radical aminocarbonylation Multicomponent reaction Carbon monoxide Unactivated alkenes AmidesIReactionmechanisms

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Vibration Control of A Flexible Marine Riser System Subject to Input Dead Zone and Extraneous Disturbances

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China Ocean Engineering 2024年第2期38卷 271-284页

作者： ZHOU Li WANG Guo-rong WAN Min School of Mechatronic Engineering Southwest Petroleum UniversityChengdu 610500China Energy Equipment Institute Southwest Petroleum UniversityChengdu 610500China National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500China

An observer-based adaptive backstepping boundary control is proposed for vibration control of flexible offshore riser systems with unknown nonlinear input dead zone and uncertain environmental disturbances.The control algorithm can update the control law online through real-time data to make the controller adapt to the environment and improve the control precision.Specifically,based on the adaptive backstepping framework,virtual control laws and Lyapunov functions are designed for each subsystem.Three direction interference observers are designed to track the timevarying boundary disturbance.On this basis,the inverse of the dead zone and linear state transformation are used to compensate for the original system and eliminate the adverse effects of the dead zone.In addition,the stability of the closed-loop system is proven by Lyapunov stability theory.All the system states are bounded,and the vibration offset of the riser converges to a small area of the initial position.Finally,four examples of flexible marine risers are simulated in MATLAB to verify the effectiveness of the proposed controller.

关键词： adaptive backstepping control disturbance observer flexible marine riser input dead zone vibration control

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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 cases.This study aimed to describe the trend of HIV positivity rate(HPR)among Chinese VCT clinics between 2015 and 2022.Methods: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 2022.The 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 analysis.Results: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%,Phe number of HPR hotspots also decreased from 41 in 2015 to 23 in 2022.These 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(AAPChe declining HPR observed in these clinics may indicates the progress has been made in some degree in mitigating HIV among high-risk populations.Therefore,it is crucial to further improving the utilization of VCT clinics for HIV testing.

关键词： VCT dividing Spatial

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U-Net Models for Representing Wind Stress Anomalies over the Tropical Pacific and Their Integrations with an Intermediate Coupled Model for ENSO Studies

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Advances in Atmospheric Sciences 2024年第7期41卷 1403-1416页

作者： Shuangying Du rong-Hua Zhang Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao266071China School of Marine Sciences Nanjing University of Information Science and TechnologyNanjing210044China Laosan Laboratory Qingdao266237China University of Chinese Academy of Sciences Beijing100049China

El Niño-Southern Oscillation(ENSO)is the strongest interannual climate mode influencing the coupled ocean-atmosphere system in the tropical Pacific,and numerous dynamical and statistical models have been developed to simulate and predict it.In some simplified coupled ocean-atmosphere models,the relationship between sea surface temperature(SST)anomalies and wind stress(τ)anomalies can be constructed by statistical methods,such as singular value decomposition(SVD).In recent years,the applications of artificial intelligence(AI)to climate modeling have shown promising prospects,and the integrations of AI-based models with dynamical models are active areas of research.This study constructs U-Net models for representing the relationship between SSTAs andτanomalies in the tropical Pacific;the UNet-derivedτmodel,denoted asτUNet,is then used to replace the original SVD-basedτmodel of an intermediate coupled model(ICM),forming a newly AI-integrated ICM,referred to as ICM-UNet.The simulation results obtained from ICM-UNet demonstrate their ability to represent the spatiotemporal variability of oceanic and atmospheric anomaly fields in the equatorial Pacific.In the ocean-only case study,theτUNet-derived wind stress anomaly fields are used to force the ocean component of the ICM,the results of which also indicate reasonable simulations of typical ENSO events.These results demonstrate the feasibility of integrating an AI-derived model with a physics-based dynamical model for ENSO modeling studies.Furthermore,the successful integration of the dynamical ocean models with the AI-based atmospheric wind model provides a novel approach to ocean-atmosphere interaction modeling studies.

关键词： U-Net models wind stress anomalies ICM integration of AI and physical components

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Practical effect of different teaching modes in teaching gastrointestinal surgery nursing

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World Journal of Gastrointestinal Surgery 2024年第1期16卷 166-172页

作者： Xiao-Juan rong Zhen Ning Department of Nursing Medical College in Jiangxi University of TechnologyNanchang 330098Jiangxi ProvinceChina

BACKGROUND With the continuous development and progress of medical technology,the position of surgical nursing in the field of clinical medicine is becoming in-creasingly prominent.As an important branch of the surgical field,the nursing requirements and difficulty of gastrointestinal surgery are also increasing.In order to improve the teaching quality of nursing care in gastrointestinal surgery,many educators and researchers are actively exploring new teaching methods.Among them,the teaching method case-based learning(CBL),scene-simulated learning(SSL),task-based learning(TBL),combining self-evaluation and training mode is considered as an effective method.This method aims to help students to better master knowledge and skills and improve their comprehensive quality by cultivating their self-evaluation ability.AIM To explore the practical effect of CBL-SSL-TBL combined with training mode and student self-assessment in nursing teaching of gastrointestinal surgery.METHODS Seventy-one nursing interns in our hospital from December 2020 to December 2021 were selected.According to different teaching modes,they were divided into observation group CBL-SSL-TBL combined with training mode combined with student self-assessment and control group(conventional teaching mode),of which 36 were in observation group and 35 were in control group.The results of operational skills,theoretical knowledge,nursing students'satisfaction,learning effectiveness questionnaire and teaching effect were compared between the two groups.RESULTS Compared between the two groups,the operational skills and theoretical knowledge scores of the observation group were higher than those of the control group,and the difference was statistically significant(Phe two groups,the total satisfaction ratio of the observation group was higher than that of the control group,the difference was statistically significant(Phe two groups,the observation group was lower than the control group in the questionnaire results

关键词： Gastrointestinal surgery Nursing teaching Teaching model Practical effect Learning ability

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Learning in games:a systematic review

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Science China(Information Sciences) 2024年第7期67卷 133-159页

作者： rong-Jun QIN Yang YU National Key Laboratory for Novel Software Technology Nanjing University Polixir Technologies

Game theory studies the mathematical models for self-interested individuals. Nash equilibrium is arguably the most central solution in game theory. While finding the Nash equilibrium in general is known as polynomial parity arguments on directed graphs(PPAD)-complete, learning in games provides an alternative to approximate Nash equilibrium, which iteratively updates the player's strategy through interactions with other players. Rules and models have been developed for learning in games, such as fictitious play and no-regret learning. Particularly, with recent advances in online learning and deep reinforcement learning,techniques from these fields greatly boost the breakthroughs in learning in games from theory to application.As a result, we have witnessed many superhuman game AI systems. The techniques used in these systems evolve from conventional search and learning to purely reinforcement learning(RL)-style learning methods,gradually getting rid of the domain knowledge. In this article, we systematically review the above techniques,discuss the trend of basic learning rules towards a unified framework, and recap applications in large games.Finally, we discuss some future directions and make the prospect of future game AI systems. We hope this article will give some insights into designing novel approaches.

关键词： non-cooperative games learning in games no-regret learning reinforcement learning superhuman AI

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Testing Linearity in Functional Partially Linear Models

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 875-886页

作者： Fan-rong ZHAO Bao-xue ZHANG School of Mathematical Sciences Shanxi UniversityTaiyuan 030006China School of Statistics Capital University of Economics and BusinessBeijing 100070China

For the functional partially linear models including flexible nonparametric part and functional linear part,the estimators of the nonlinear function and the slope function have been studied in existing literature.How to test the correlation between response and explanatory variables,however,still seems to be missing.Therefore,a test procedure for testing the linearity in the functional partially linear models will be proposed in this paper.A test statistic is constructed based on the existing estimators of the nonlinear and the slope functions.Further,we prove that the approximately asymptotic distribution of the proposed statistic is a chi-squared distribution under some regularity conditions.Finally,some simulation studies and a real data application are presented to demonstrate the performance of the proposed test statistic.

关键词： asymptotic theory functional partially linear model Nadaraya-Watson estimate test statistic

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Market-based solution in China to finance the clean from the dirty

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Fundamental Research 2024年第2期4卷 324-333页

作者： Haoqi Qian rong Ma Libo Wu Institute for Global Public Policy Fudan UniversityShanghai 200433China LSE-Fudan Research Centre for Global Public Policy Fudan UniversityShanghai 200433China School of Economics Fudan UniversityShanghai 200433China Shanghai Institute for Energy and Carbon Neutrality Strategy Fudan UniversityShanghai 200433China

Financial incentives play a key role in promoting renewable energy investments that can help China achieve the‘dual carbon’goal.The national emissions trading scheme(ETS)and the renewable energy portfolio standard(RPS)are two existing market-based policy instruments that can generate stable expected returns for low-carbon projects.This paper studies the interactive distribution effects of these two market-based instruments.We use the micro-level thermal power plant data to investigate the abatement effects of the national ETS,in which the details show that the existing rate-based ETS will result in higher negative impacts on power units,whose installed capacities are smaller than 400 MW.The interactive distribution effects between the two markets will occur when the permit allocation standards of the national ETS become stricter than the existing ones.Provinces in Eastern China and Northern China will face high pressure on costs in both ETS and RPS markets.When the levels of the permit allocation standards are set as 70%of the existing ones and the carbon price is assumed to be 200 yuan/ton in 2030,the annual market size of the national ETS will be nearly 100 billion yuan,and the annual market size is predicted to be 250 billion yuan.In the existing rate-based national ETS,the China Certified Emission Reduction(CCER)mechanism will have an offsetting effect,which should be taken into serious consideration during the policy-making processes in the future.

关键词： Emission trading scheme Renewable energy portfolio standard Green finance Policy interactions China certified emission reduction Distribution effect

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