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Managing Climate Change Risk in China's Agricultural Sector: The potential for an Integrated Risk Management Framework

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Journal of Integrative Agriculture 2014年第7期13卷 1418-1431页

作者： kevin Z.chen Claire Hsu International Food policy Research Institute-Beijing Office

Climate change poses a serious threat to the future food security of China, which is among the most disaster-prone countries in the world. This paper discusses the implications of climate change for China＇s agricultural sector. Its main objectives are to identify the agricultural risks associated with climate change, to introduce a conceptual framework for agricultural climate risk management and to enumerate key adaptation strategies, challenges, and recommendations.

关键词： climate change food security risk management agricultural development

A stock assessment for Illex argentinus in Southwest Atlantic using an environmentally dependent surplus production model

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Acta Oceanologica Sinica 2018年第2期37卷 94-101页

作者： WANG Jintao chen Xinjun kevin W.Staples chen Yong College of Marine Sciences Shanghai Ocean University Shanghai 201306 China National Distant-water Fisheries Engineering Research Center Shanghai Ocean University Shanghai 201306 China Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources of Ministry of Education Shanghai Ocean University Shanghai 201306 China School of Marine Sciences University of Maine Orono Maine 04469 USA Collaborative Innovation Center for National Distant-water Fisheries Shanghai 201306 China

The southern patagonian stock（SpS） of Argentinian shortfin squid, Illex argentinus, is an economically important squid fishery in the Southwest Atlantic. Environmental conditions in the region play an important role in regulating the population dynamics of the I. argentinus population. This study develops an environmentally dependent surplus production（EDSp） model to evaluate the stock abundance of I. argentines during the period of 2000 to 2010. The environmental factors（favorable spawning habitat areas with sea surface temperature of 16–18°C） were assumed to be closely associated with carrying capacity（K） in the EDSp model. Deviance Information Criterion（DIC） values suggest that the estimated EDSp model with environmental factors fits the data better than a Schaefer surplus model without environmental factors under uniform and normal *** EDSp model estimated a maximum sustainable yield（MSY） from 351 600 t to 685 100 t and a biomass from 1 322 400 t to1 803 000 t. The fishing mortality coefficient of I. argentinus from 2000 to 2010 was smaller than the values of F（0.1） and F（MSY）. Furthermore, the time series biomass plot of I. argentinus from 2000 to 2010 shows that the biomass of *** and this fishery were in a good state and not presently experiencing overfishing. This study suggests that the environmental conditions of the habitat should be considered within squid stock assessment and management.

关键词： Illex argentinus stock assessment Schaefer surplus production model environmental factors Southwest Atlantic

Evaluation of different Krylov subspace methods for simulation of the water faucet problem

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Nuclear Science and Techniques 2021年第5期32卷 1-16页

作者： Hong-Yang Wei kevin Briggs Victor Quintanilla Yi-Tung chen Department of Mechanical Engineering University of NevadaLas VegasNV 89154USA

In this study,a one-dimensional two-phase flow four-equation model was developed to simulate the water faucet *** performance of six different Krylov subspace methods,namely the generalized minimal residual(GMRES),transpose-free quasi-minimal residual,quasi-minimal residual,conjugate gradient squared,biconjugate gradient stabilized,and biconjugate gradient,was evaluated with and without the application of an incomplete LU(ILU)factorization preconditioner for solving the water faucet *** simulation results indicate that using the ILU preconditioner with the Krylov subspace methods produces better convergence performance than that without the ILU *** the GMRES demonstrated an acceptable convergence performance under the Krylov subspace methods without the *** velocity and pressure distribution in the water faucet problem could be determined using the Krylov subspace methods with an ILU preconditioner,while GMRES could determine it without the need for a ***,there are significant advantages of using an ILU preconditioner with the GMRES in terms of *** different Krylov subspace methods showed similar performance in terms of computational efficiency under the application of the ILU preconditioner.

关键词： Water faucet problem Krylov subspace methods ILU preconditioner

Food safety regulatory systems in Europe and China:A study of how co-regulation can improve regulatory effectiveness

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Journal of Integrative Agriculture 2015年第11期14卷 2203-2217页

作者： kevin chen WANG Xin-xin SONG Hai-ying Beijing Office International Food Policy Research Institute School of Economics and International Trade Zhejiang University of Finance and Economics International Business Administration College Zhejiang International Studies University

Food safety has received a great deal of attention in both developed and developing countries in recent years. In China, the numerous food scandals and scares that have struck over the past decade have spurred significant food safety regulatory reform, which has been increasingly oriented towards the public-private partnership model adopted by the Europe Union＇s （EU） food safety regulatory system. This paper analyzes the development of both the EU＇s and China＇s food safety regu- latory systems, identifies the current challenges for China and additionally considers the role of public-private partnership. The success of co-regulation in the food regulatory system would bring significant benefits and opportunities for China. Finally, this paper recommends additional measures like training and grants to improve the private＇s sector effectiveness in co-regulating China＇s food safety issues.

关键词： food safety co-regulation public-private partnership Food Safety Law of China European Union China

Development of barium@alginate adsorbents for sulfate removal in lithium refining

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Frontiers of Chemical Science and Engineering 2021年第1期15卷 198-207页

作者： Lisa Xu Kaifei chen George Q.chen Sandra E.Kentish Gang(kevin)Li Department of Chemical Engineering The University of MelbourneParkvilleVIC 3010Australia

The demand for lithium has been steadily growing in recent years due to the boom of electric *** purity lithium is commonly used in the manufacture of battery grade lithium *** residuals originating from acid leaching of lithium ores must be limited to below 20 mg·L^(−1) during *** are methods to remove sulfate such as membrane processing and chemical precipitation using barium ***,membrane separation is unable to achieve the required purity while chemical precipitation often causes secondary contamination with barium and requires extra filtration processes that lead to increased processing *** this study,we developed a polymeric matrix entrapped with barium ions as a novel adsorbent to selectively adsorb sulfate in aqueous *** adsorbent was prepared by dropwise injection method where alginate droplets were crosslinked with barium to form hydrogel *** a typical scenario,the microcapsules had a diameter of 3 mm and contained 5 wt-%*** microcapsules could successfully reduce sulfate concentration in a solution from 100 to 16 mg·L^(−1),exceeding the removal ***,the microcapsules were mechanically unstable in the presence of an excess amount of ***,calcium ions were added as a secondary crosslinking agent to improve the integrity of the *** two-step Ca/Ba@alginate microcapsules showed an exceptional adsorption performance,reducing the sulfate concentration to as low as 0.02 mg·L^(−1).Since the sulfate selective microcapsules can be easily removed from the aqueous system and do not result in secondary barium contamination,these Ca/Ba@alginate adsorbents will find applications in ultra-refining of lithium in industry.

关键词： barium@alginate microcapsules dropwise injection sulfate removal lithium

Optimising Body Layout Design of Limbed Machines

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Journal of Bionic Engineering 2007年第2期4卷 117-122页

作者： Shu-jun Zhang Jin Tong kevin Hapeshi Dong-hui chen Computing Department Gloucestershire University Cheltenham GL50 2HR UK Key Laboratory of Terrain-Machine Bionics Engineering （Ministry of Education China） Jilin University Changchun 130022 P. R. China

This paper presents our efforts to explain why mammals have large thigh muscles while insects have small ones. After a discussion of this observation a definition of body foot ratio is defined which describes how animals stand and how their legs are arranged. To investigate the mechanics, we present a closed optimum solution of the body foot ratio for a 2D two-leg walking machine. A multi-walker is used as a case for 3D general analysis, and the numerical simulation is presented. Both 2D and 3D case studies can explain the above observations of mammals and insects. These findings can also be used as a guide for the design of man-made limbed machines.

关键词： bio-inspiration body design walking machine limbed machine

Constrained control of free piston engine generator based on implicit reference governor

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Science China(Information Sciences) 2018年第7期61卷 40-56页

作者： Xun GONG Ilya KOLMANOVSKY Emanuele GARONE kevin ZASECK Hong chen State Key Laboratory of Automotive Simulation and Control Jilin University Department of Aerospace Engineering University of Michigan Ecole polytechnique Universite Libre de Bruxelles

The free piston engine generator(FpEG) is a novel power plant concept for series hybrid electric vehicles(HEV) that requires reliable control to regulate piston motion and guarantee safe operation during load transitions. This paper focuses on the control and constraint enforcement in a FpEG using a reference governor. A discrete, implicit, control oriented model describing the piston motion in a two-stroke twocylinder FpEG at the turnaround point is derived based on energy balance and a feedback controller is designed to track the desired turnaround position by regulating fuel. An implicit reference governor is developed to guarantee safe piston motion by managing the load transitions. The reference governor utilizes Newton’s method applied to an implicit nonlinear model for response prediction and a bisection search algorithm to enforce the constraints for all the future time instants by adjusting the reference ***, the error in applying one iteration of Newton’s method in predicting the response of the implicit nonlinear system is estimated and accounted for in constraint tightening to guarantee that constraints are robustly enforced. The simulation results show that the feedback control scheme incorporating the developed implicit reference governor can effectively enforce the prescribed constraints during load transition.

关键词： free piston engine generator implicit system reference governor Newton’s method error bound

A DEA-TOpSIS METHOD FOR MULTIpLE CRITERIA DECISION ANALYSIS IN EMERGENCY MANAGEMENT

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Journal of Systems Science and Systems Engineering 2009年第4期18卷 489-507页

作者： Ye chen kevin W. LI Haiyan XU Sifeng LIU College of Economies and Management Nanjing University of Aeronautics and Astronautics Nanjing Jiangshu 210016 China Odette School of Business University of Windsor Windsor Ontatio N9B 3P4 Canada Department of Systems Design Engineering University of Waterloo Waterloo Ontario N2L3G1 Canada

A hybrid approach of DEA （data envelopment analysis） and TOpSIS （technique for order performance （preference） by similarity to ideal solution） is proposed for multiple criteria decision analysis in emergency management. Two DEA-based optimization models are constructed to facilitate identifying parameter information regarding criterion weights and quantifying qualitative criteria in TOpSIS. An emergency management case study utilizing data from the Emergency Management Australia （EMA） Disasters Database is provided to demonstrate the feasibility of the proposed analysis procedure.

关键词： Multiple criteria decision analysis multiple criteria ranking DEA TOpSIS emergency management

BUILDING CLIMATE-RESILIENT FOOD SYSTEMS IN EAST AND SOUTHEAST ASIA:VULNERABILITIES,RESpONSES AND FINANCING

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Frontiers of Agricultural Science and Engineering 2023年第1期10卷 16-30页

作者： Yunyi ZHOU Ziqi chen kevin Z.chen China Academy for Rural Development and School of public Affairs Zhejiang UniversityHangzhou 310058China International Food policy Research Institute Washington DC 20005USA

Food system resilience to climate change is uniquely imperative for bringing Sustainable Development Goals within reach and leaving no one *** systems in East and Southeast Asia are interacting with planetary boundaries and are adversely affected by extreme weather-related events.A practical question for East and Southeast Asian stakeholders is how to foster climate-resilient food systems in the face of lingering food system vulnerabilities and policy *** paper reviews food system vulnerabilities and policy responses to climate *** the policy-based review,this paper compares the economy-wide and agriculture-specific targets of low-carbon development across East and Southeast *** China and member states of the Association of Southeast Asia Nations as case studies,multilevel policies in building and financing climate-resilient food systems are further *** findings confirm significant differences in agriculture-specific emission goals and public financing supports across East and Southeast Asian *** an objective to break practical barriers and finance climate-resilient food systems for the future,this paper recommends defining agriculture-specific greenhouse gas emission goals,reorienting the public finance scheme and enhancing mechanisms for the synergy of public and private resources.

关键词： food systems climate change East policy resilience and Southeast Asia