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Modeling Climate Change Impacts on the US Agricultural Exports

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Journal of Integrative Agriculture 2014年第4期13卷 666-676页

作者： ZhANG Yu-quan cai Yong-xia beach Robert h McCARL bruce A Agricultural Resource & Energy Economics and Policy ProgramRTI InternationalResearch Triangle Park Department of Agricultural Economics Texas A&M UniversityCollege Station

Climate change is expected to have substantial effects on agricultural productivity worldwide. however, these impacts will differ across commodities, locations and time periods. As a result, landowners will see changes in relative returns that are likely to induce modifications in production practices and land allocation. In addition, regional variations in impacts can alter relative competitiveness across countries and lead to adjustments in international trade patterns. Thus in climate change impact studies it is likely useful to account for worldwide productivity effects. In this study, we investigate the implications of considering rest of world climate impacts on projections of the US agricultural exports. We chose to focus on the US because it is one of the largest agricultural exporters. To conduct our analyses, we consider four alternative climate scenarios, both with and without rest of world climate change impacts. Our results show that considering/ignoring rest of world climate impacts causes significant changes in the US production and exports projections. Thus we feel climate change impact studies should account not only for climate impacts in the country of focus but also on productivity in the rest of the world in order to capture effects on commodity markets and trade potential.

关键词： climate change relative competitiveness trade agricultural sector model (ASM)

Geodesics in the Engel Group with a Sub-Lorentzian Metric——the Space-Like Case

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Chinese Annals of Mathematics,Series b 2020年第1期41卷 147-162页

作者： Qihui cai Department of Mathematics and Computer Science School of Biomedical Engineering and InformaticsNanjing Medical UniversityNanjing 211166China

Let E be the Engel group and D be a bracket generating left invariant distribution with a Lorentzian metric, which is a nondegenerate metric of index 1. In this paper, the author constructs a parametrization of a quasi-pendulum equation by Jacobi functions, and then gets the space-like hamiltonian geodesics in the Engel group with a sub-Lorentzian metric.

关键词： Sub-Lorentzian metric Engel Group Geodesics

3-D discontinuum numerical modeling of subsidence incorporating ore extraction and backfilling operations in an underground iron mine in China

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International Journal of Mining Science and Technology 2017年第2期27卷 191-201页

作者： huang Gang Kulatilake Pinnaduwa h.S.W. Shreedharan Srisharan cai Sijing Song hongqing School of Resources and Environmental Engineering Wuhan University of Technology School of Civil and Environmental Engineering University of Science and TechnologyBeijing Rock Mass Modeling and Computational Rock Mechanics Laboratories University of Arizona

An underground iron mine in China has been used as a case-study to research the subsidence due to ore extraction and backfilling during open stoping operations. A 3-D discontinuum numerical model was built incorporating geologic complexities including faults and interfaces between different lithologies,and the stoping and backfilling sequence adopted from the mine plans. The stoping was carried out in two vertically stacked horizontal layers, with a total of 16 stopes. Large displacements of up to 50 cm were observed along the roof of the stopes, and a maximum surface subsidence of 22.5 cm was *** was found to eliminate subsequent displacements and subsidence. The extraction of the upper orebody was found to influence displacements in the lower orebody. Finally, a subsidence profile was constructed to show the subsidence at all locations along the length of the surface and region of influence on the surface.

关键词： Underground iron mine Discontinuum numerical modeling Open stoping backfill Subsidence

A novel unsupervised deep learning method for the generalization of urban form

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Geo-Spatial Information Science 2022年第4期25卷 568-587页

作者： Jihong cai Yimin Chen School of Geography and Planning Sun Yat-sen UniversityGuangzhouChina

Accurate delineation of urban form is essential to understand the impacts that urbanization has on the environment and regional *** supervised classification of urban form requires a rigidly defined scheme and high-quality sample data with class *** to the complexity of urban systems,it is challenging to consistently define urban form types and collect metadata to describe ***,in this study,we propose a novel unsupervised deep learning method for urban form delineation while avoiding the limitations of conventional super-vised urban form classification *** novelty of the proposed method is the Multiscale Residual Convolutional Autoencoder(MRCAE),which can learn the latent representation of differ-ent urban form *** vectors can be further used to generalize urban form types by using Self-Organizing Map(SOM)and the Gaussian Mixture Model(GMM).The proposed method is applied in the metropolitan area of Guangzhou-Foshan,*** MRCAE model along with SOM and GMM is used to generalize the urban form types from satellite *** physical and functional properties of each urban form type are also analyzed using several auxiliary datasets,including building footprints,Points-of-Interests(POIs)and Tencent User Density(TUD)*** results reveal that the urban form map generated based on the MRCAE can explain 55%of the building height distribution and 55%of the building area distribution,which are 2.1%and 3.3%higher than those derived from the conventional convolutional *** the information of urban form is essential to urban climate models,the results presented in this study can become a basis to refine the quantification of urban climate parameters,thereby introducing the urban heterogeneity to help understand the climate response of future urbanization.

关键词： Convolutional autoencoder Self-Organizing Map(SOM) Gaussian Mixture Model(GMM) urban form clustering

Exosomes: a novel therapeutic target for Alzheimer's disease?

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Neural Regeneration Research 2018年第5期13卷 930-935页

作者： Zhi-You cai Ming Xiao Sohel h.Quazi Zun-Yu Ke Department of Neurology Chongqing General Hospital Department of Anatomy Nanjing Medical University Department of biological and health Sciences Texas A & M University-Kingsville Department of Neurology Renmin Hospital Hubei University of Medicine

Extracellular exosomes are formed inside the cytoplasm of cells in compartments known as multivesicular bodies. Thus, exosomes contain cytoplasmic content. Multivesicular bodies fuse with the plasma membrane and release exosomes into the extracellular environment. Comprehensive research suggests that exosomes act as both inflammatory intermediaries and critical inducers of oxidative stress to drive progression of Alzheimer＇s disease. An important role of exosomes in Alzheimer＇s disease includes the formation of neurofibrillary tangles and beta-amyloid production, clearance, and accumulation. In addition, exosomes are involved in neuroinflammation and oxidative stress, which both act as triggers for beta-amyloid pathogenesis and tau hyperphosphorylation. Further, it has been shown that exosomes are strongly associated with beta-amyloid clearance. Thus, effective measures for regulating exosome metabolism may be novel drug targets for Alzheimer＇s disease.

关键词： nerve regeneration microvesicle beta-amyloid tau neuroinflammation oxidative stress therapeutic target neurodegeneration dementia neural regeneration

Stability and optoelectronic property of low-dimensional organic tin bromide perovskites

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Chinese Physics b 2021年第3期30卷 483-487页

作者： J h Lei Q Tang J he M Q cai School of Science Hunan University of TechnologyZhuzhou 412007China School of Physics and Electronics Science Hunan UniversityChangsha 410082China

The toxicity and degradation of hybrid lead-halide perovskites hinder their extensive *** is thus of great importance to explore non-toxic alternative materials with excellent stability and optoelectronic *** investigate the atomic structures and optoelectronic properties of non-toxic organic tin bromide perovskites(OTbP)with one/zerodimensional(1D/0D)structures by first-principles *** calculated atomic structures show that the 1D/0D OTbPs are stable and the structure of inorganic octahedra in 0D is higher order than that in ***,the origination of exceptional purity emitting light in experiments is explained based on the calculated electronic structure.

关键词： one/zero dimensional non-toxic organic tin bromide perovskites first principle calculation stability Optoelectronic property

Parameter identification and blanking simulations of DP1000 and Al6082-T6 using Lemaitre damage model

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Advances in Manufacturing 2021年第3期9卷 457-472页

作者： Sheng cai Lin Chen Department of Vehicle Engineering College of EngineeringChina Agricultural UniversityBeijing100083People’s Republic of China CW bearing Gmbh 22113HamburgGermany

This work provides numerical and experimental investigations of blanking process,where the shear-enhanced Lemaitre’s damage model is fully characterized and successfully applied in blanking process to predict the cutting force and cutting edge geometry under different blanking process *** high strength steel DP1000 and an aluminum alloy Al6082-T6 are selected for series of *** obtain the damage parameters in Lemaitre’s damage model the flat rectangular notched specimens tensile test was conducted and the inverse parameter identification procedure was *** characterizing the crack closure parameter h in the shear enhanced Lemaitre’s damage model,an in-plane torsion test with novel specimen design was *** finite element model(FEM)of this test was established with the minimum mesh size of 0.01 mm which was consistent with the minimum mesh size in the shear zone of the FEM for blanking process *** longitudinal strain distributions of four kinds of initial notch radius or central-hole specimen were measured and compared with simulation results to validate the FEMs for these four *** analysis of blanking of a circular work piece also was performed under three *** effects of blanking conditions on sheared part morphology were *** triaxiality distribution of the blank sheet was revealed taking advantage of the successfully established *** availability of the testing method and the determination method of the parameters was investigated.

关键词： blanking Lemaitre damage model Stress triaxiality Finite element model(FEM)

MULTIPLE PARAMETERS IDENTIFICATION PRObLEMS IN RESISTIVITY WELL-LOGGING

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Chinese Annals of Mathematics,Series b 1998年第3期19卷 265-272页

作者： cai ZhIJIE Fudan Univ Dept Math Shanghai 200433 Peoples R China

In petroleum exploitation, the main aim of resistivity well-logging is to determine the resistivity of the layers by measuring the potential on the electrodes. This mathematical problem can be described as an inverse problem for the elliptic equivalued surface boundary value problem. In this paper, the author gets the expression of the derivative functions of the potential on the electrodes with respect to the resistivity of the layers. This allows us to solve the identification problem of the resistivity of the layers.

关键词： Multiple parameters identification problem Resistivity well-logging Inverse problem Equivalued surface boundary value problem

A Remark on Chen’s Theorem (Ⅱ)

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Chinese Annals of Mathematics,Series b 2008年第6期29卷 687-698页

作者： Yingchun cai Department of Mathematics Tongji University Shanghai 200092 China

Let p denote a prime and P2 denote an almost prime with at most two prime factors. The author proves that for sufficiently large x,∑p≤x p＋2=P2 1〉1.13Cx/log^2x,where the constant 1.13 constitutes an improvement of ... 详细信息

关键词： Chen's theorem Sieve Mean value theorem