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Flume Experiment Investigation on Propagation Characteristics of Tidal Bore in A Curved Channel

China Ocean Engineering 2023年第1期37卷 131-144页

作者： FAN Jun TAO Ai-feng SHI mo-quan LI Ying PENG Ji Key Laboratory of Ministry of Education for Coastal Disaster and Protection Hohai UniversityNanjing 210098China College of Harbour Coastal and Offshore EngineeringHohai UniversityNanjing 210098China The Adminstrative Committee of Nantong Haimen Sanchang Industrial Park Nantong 226121China Zhejiang University of Water Resources and Electric Power Hangzhou 310018China China Renewable Energy Engineering Institute Beijing 100120China

Tidal bore is a special and intensive form of flow movement induced by tidal effect in estuary areas, which has complex characteristics of profile, propagation and flow velocity. Although it has been widely studied for the generation mechanism, propagation features and influencing factors, the curved channel will complicate the characteristics of tidal bore propagation, which need further investigation compared with straight channel. In this study, the flume experiments for both undular and breaking bores’ propagation in curved channel are performed to measure the freesurface elevation and flow velocity by ultrasonic sensors and ADV respectively. The propagation characteristics,including tidal bore height, cross-section surface gradient, tidal bore propagation celerity, and flow velocity are obtained for both sides of the curved channel. And three bore intensities are set for each type of tidal bores. The freesurface gradients are consistently enlarged in high-curvature section for undular and breaking bores, but have distinct behaviors in low-curvature section. The spatial distributions of tidal bore propagation celerity and flow velocity are compared between concave and convex banks. This work will provide experimental reference for engineering design of beach and seawall protection, erosion reduction and siltation promotion in estuary areas with the existence of tidal bores.

关键词： tidal bore curved channel flume experiment propagation celerity bore intensity

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Risk preferences and the low-carbon agricultural technology adoption:Evidence from rice production in China

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Journal of Integrative Agriculture 2023年第8期22卷 2577-2590页

作者： MAO hui quan Yu-rong FU Yong Northwest Institute of Historical Environment and Socio-Economic Development Shaanxi Normal UniversityXi'an 710119P.R.China College of Economics and Management Nanjing Agricultural UniversityNanjing 210095P.R.China

Climate change which is mainly caused by carbon emissions is a global problem affecting the economic development and well-being of human ***-carbon agriculture is of particular significance in slowing down global warming and reaching the goal of“carbon peak and carbon neutrality”.Therefore,taking straw incorporation as an example,this paper aims to investigate the impact of risk preferences on farmers’low-carbon agricultural technology(LCAT)*** on a two-phase micro-survey data of 1038 rice farmers in Jiangsu,Jiangxi,and Hunan provinces,this paper uses experimental economics methods to measure farmers’risk aversion and loss aversion to obtain the real risk preferences information of the *** also explore the data to examine the actual LCAT adoption behavior of *** results revealed that both risk aversion and loss aversion significantly inhibit farmers’LCAT adoption:more risk-averse or more loss-averse farmers are less likely to adopt *** is further found that crop insurance,farm scale and governmental regulations can alleviate the negative impact of risk aversion and loss aversion on farmers’LCAT ***,we propose that local governments need to promote low-carbon agricultural development by propagating the benefits of LCAT,extending crop insurance,promoting appropriate scale operations,and strengthening governmental regulations to promote farmers’LCAT adoption.

关键词： risk preferences crop insurance farm scale governmental regulations low-carbon agricultural technology

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Homotopic Mapping Solving Method for Perturbed Mechanism of Western Boundary Undercurrents in Equator Pacific

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Chinese Geographical Science 2006年第4期16卷 347-350页

作者： mo Jiaqi WANG hui LIN Wantao Department of Mathematics Anhui Normal University Wuhu 241000 China Division of Computational Science E-Instilutes of Shanghai Universities Shanghai Jiaotong University Shanghai 200240 China Department of Mathematics Huzhou Teachers College Huzhou 313000 China Chinese Academy of Meteorological Sciences Beijing 100081 China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The perturbed boundary undercurrent is an exceptional event in the tropical atmosphere and ocean. It is a complicated nonlinear system. Its appearance badly affects not only natural conditions such as climate and environment, but also global economic development and human living, and brings about many calamities. Thus there is very attractive study on its rules in the international academic circles. Many scholars made more studies on its local and whole behaviors using different methods, such as self-anamnestic principle, Fokker-Plank Equation method, higher order singular pedigree and predictable study, rapid change on boundary, indeterminate adaptive control, multi-eogradient method and so on. Nonlinear perturbed theory and approximate method are very attractive studies in the international academic circles. Many scholars considered a class of nonlinear problems for the ordinary differential equation, the reaction diffusion equations, the boundary value of elliptic equation, the initial boundary value of hyperbolic equation, the shock layer solution of nonlinear equation and so on. In this paper, a class of perturbed mechanism for the western boundary undercurrents in the equator Pacific is considered. Under suitable conditions, using a homotopic mapping theory and method, we obtain a simple and rapid arbitrary order approximate solution for the corresponding nonlinear system. For example, a special case shows that using the homotopic mapping method, there is a high accuracy for the computed value. It is also provided from the results that the solution for homotopic mapping solving method can be used for analyzing operator for perturbed mechanism of western boundary undercurrents in the equator Pacific.

关键词： undercurrent perturbation approximate solution equator Pacific

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Singularly Perturbed Solution of Coupled model in Atmosphere-ocean for Global Climate

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Chinese Geographical Science 2008年第2期18卷 193-196页

作者： mo Jiaqi LIN Wantao WANG hui Department of Mathematics Anhui Normal University Wuhu 241000 China Division of Computational Science E-Institutes of Shanghai Universities at SJTU Shanghai 200240 China Huzhou Teachers College Huzhou 313000 China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Chinese Academy ofMeteorological Sciences Beijing 100081 China

A box model of the interhemispheric thermohaline circulation (THC) in atmosphere-ocean for global cli-mate is considered. By using the multi-scales method, the asymptotic solution of a simplified weakly nonlinear model is discussed. Firstly, by introducing first scale, the zeroth order approximate solution of the model is obtained. Sec-ondly, by using the multi-scales, the first order approximate equation of the model is found. Finally, second order ap-proximate equation is formed to eliminate the secular terms, and a uniformly valid asymptotic expansion of solution is decided. The multi-scales solving method is an analytic method which can be used to analyze operation sequentially. And then we can also study the diversified qualitative and quantitative behaviors for corresponding physical quantities. This paper aims at providing a valid method for solving a box model of the nonlinear equation.

关键词： atmosphere-ocean El Nino-Southern Oscillation singular perturbation approximate solution

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Thickness Effect on (La_(0.26)Bi_(0.74))_2Ti_4O_(11) Thin-Film Composition and Electrical Properties

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Chinese Physics Letters 2018年第2期35卷 66-70页

作者： hui-Zhen Guo An-quan Jiang State Key Laboratory of ASIC & System School of MicroelectronicsFudan University

Highly oriented（00l）（La_（0.26）Bi_（0.74））_2Ti_4O_（11 ）thin films are deposited on（100） SrTiO_（3 ）substrates using the pulsed laser deposition *** grains form a texture of bar-like arrays along Sr Ti O_3110directions for the film thickness above 350 nm,in contrast to spherical grains for the reduced film thickness below 220 nm.X-ray diffraction patterns show that the highly ordered bar-like grains are the ensemble of two lattice-matched monoclinic（La,Bi）_4Ti_3O_（12 ）and TiO_（2 ）components above a critical film ***,the phase decomposes into the random mixture of Bi_2Ti_2O_（7 ）and Bi_4Ti_3O_（4 ）spherical grains in thinner *** critical thickness can increase up to 440 nm as the films are deposited on LaNiO_3-buffered SrTiO_（3 ）*** electrical measurements show the dielectric enhancement of the multi-components,and comprehensive charge injection into interfacial traps between（La,Bi）_4Ti_3O_（12 ）and TiO_（2 ）components occurs under the application of a threshold voltage for the realization of high-charge storage.

关键词： Bi Ti Thin-Film Composition and Electrical Properties LNO La

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The predicted effects of climate change on local species distributions around Beijing,China

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Journal of Forestry Research 2020年第5期31卷 1539-1550页

作者： Lichun mo Jiakai Liu hui Zhang Yi Xie School of Economies and Management Beijing Forestry UniversityBeijingPeople’s Republic of China School of Nature Conservation Beijing Forestry UniversityBeijingPeople’s Republic of China

To assist conservationists and policymakers in managing and protecting forests in Beijing from the effects of climate change,this study predicts changes for 2012–2112 in habitable areas of three tree species—Betula platyphylla,Quercus palustris,Platycladus orientalis,plus other mixed broadleaf species—in Beijing using a classification and regression tree niche model under the International Panel on Climate Change’s A2 and B2 emissions scenarios(SRES).The results show that climate change will increase annual average temperatures in the Beijing area by 2.0–4.7℃,and annual precipitation by 4.7–8.5 mm,depending on the emissions scenario *** changes result in shifts in the range of each of the *** suitable areas for distributions of *** and *** will decrease in the *** model points to significant shifts in the distributions of these species,withdrawing from their current ranges and pushing southward towards central *** of the ranges decline during the initial 2012–2040 period before shifting southward and ending up larger overall at the end of the 88-year *** mixed broadleaf forests expand their ranges *** *** forests,on the other hand,expand their range *** results indicate that climate change and its effects will accelerate significantly in Beijing over the next 88 *** stress is likely to be a major limiting factor on the distribution of forests and the most important factor affecting migration of species into and out of existing nature *** is a potential for the extinction of some ***,long-term vegetation monitoring and warning systems will be needed to protect local species from habitat loss and genetic swamping of native species by hybrids.

关键词： Climate change Classification and regression tree Plant distribution Scenario A2 and B2 Simulation analysis

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Territorial suitability assessment and function zoning in the Jiuzhaigou earthquake-stricken area

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Journal of mountain Science 2019年第1期16卷 195-206页

作者： YU hui QIANG Miao LIU Shao-quan Institute of mountain Hazards and Environment Chinese Academy of Sciences University of Chinese Academy of Sciences Chengdu Pidu Disstrict Mianshi Foreign Language School

An earthquake in the Jiuzhaigou area caused numerous secondary disasters, such as rolling stones, land collapse, landslides and debris flow, which badly affected the safety of human settlements and influenced the spatial layout of the post-disaster reconstruction. Therefore, carrying out assessments of land and identifying a suitable zone for human habitats were very important. This research creates the territorial suitability assessment and function zoning conceptual model in the earthquake-stricken area, and the new methods of the territorial suitability evaluation system were used to divide the spatial functional zones of the earthquake stricken area, which provide a theoretical guidance and decisionmaking basis for the reconstruction of the disaster area. The results showed that:(1) The Jiuzhaigou earthquake-stricken area comprises of an ecological area that has a high level of importance to the ecosystem. In the earthquake-stricken area, 65% of national land is at an altitude of 3000-4000 m, and therefore not suitable for a high level of intensive reconstruction, but reconstructed in an eco-friendly manner.(2) The zone suitable for reconstruction comprises mainly of the river valley and the flat terrain of western parts. The land with low suitability is mainly located on steep terrain, such as highmountains and low gullies. The geographic and geomorphic conditions limit the spread of a suitable reconstruction zone.(3) The earthquake-stricken area mainly comprises of a tourism industry gathering area, population gathering area, agriculture and animal husbandry development area, and ecological preservation area with areas of 76 km^2, 44 km^2, 1591 km^2 and 7512 km^2, respectively. Scientifically zoning the reconstruction areas using scientific evaluation may provide guidance for the location of reconstruction sites.

关键词： Jiuzhaigou valley Earthquake-stricken area Territorial suitability Function zoning

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A kind of biomimetic control method to anthropomorphize a redundant manipulator for complex tasks

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Science China(Technological Sciences) 2020年第1期63卷 14-24页

作者： mo Yang JIANG ZhiHong LI hui YANG Hong HUANG Qiang School of Mechatronic Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Advanced Innovation Center for Intelligent Robots and Systems Beijing 100081China Key Laboratory of Biomimetic Robots and Systems Ministry of EducationBeijing 100081China Institute of Manned Spacecraft System Engineering China Academy of Space TechnologyBeijing 100080China

It is an urgent problem for robots to operate complex tasks with some unknown motion mechanisms caused by the strong coupling of force and motion. However, humans can perform complex tasks well due to their natural evolution and postnatal training. A novel biomimetic control method based on a human motion mechanism with high movement adaptability is proposed in this paper. The core is to present a novel variable-parameter compliance controller based on human operation mechanisms with an action-planning method derived from optimization by human motion, and the main contribution is to change the parameters of compliance controller according to human operating intention synchronized with humanoid motion;this change could establish a humanoid map between the force and motion for a seven degree-of-freedom redundant manipulator to deal with the unknown motion mechanism in complex tasks, so the redundant manipulator can operate complex tasks with high performance. Sufficient experiments were performed, and the results validated the effectiveness of the proposed algorithm.

关键词： redundant manipulator biomimetic control humanoid mapping complex task

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On infinite arithmetic progressions in sumsets

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Science China Mathematics 2023年第12期66卷 2669-2682页

作者： Yong-Gao Chen quan-hui Yang Lilu Zhao School of Mathematical Sciences and Institute of Mathematics Nanjing Normal UniversityNanjing 210023China School of Mathematics and Statistics Nanjing University of Information Science and TechnologyNanjing 210044China School of Mathematics Shandong UniversityJinan 250100China

Let k be a positive *** by D_(1/k)the least integer d such that for every set A of nonnegative integers with the lower density 1/k,the set(k+1)A contains an infinite arithmetic progression with difference at most d,where(k+1)A is the set of all sums of k+1 elements(not necessarily distinct)of *** and Li(2019)conjectured that D_(1/k)=k~2+o(k~2).The purpose of this paper is to confirm the above *** also prove that D_(1/k)is a prime for all sufficiently large integers k.

关键词： infinite arithmetic progressions sumsets primes circle method

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Science Letters:Nitrogen doping of activated carbon loading Fe_2O_3 and activity in carbon-nitric oxide reaction

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第5期8卷 707-711页

作者： WAN Xian-kai ZOU Xue-quan SHI hui-xiang WANG Da-hui Institute of Environmental Engineering Zhejiang University Hangzhou 310027 China

Nitrogen doping of activated carbon loading Fe2O3 was performed by annealing in ammonia, and the activity of the modified carbon for NO reduction was studied in the presence of oxygen. Results show that Fe2O3 enhances the amount of surface oxygen complexes and facilitates nitrogen incorporation in the carbon, especially in the form of pyridinic nitrogen. The modified carbon shows excellent activity for NO reduction in the low temperature regime （〈500℃） because of the cooperative effect of Fe2O3 and the surface nitrogen species.

关键词： Activated carbon Nitric oxide Doping Iron oxides Catalytic reduction

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