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Invasion syndromes:hypotheses on relationships among invasive species attributes and characteristics of invaded sites

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Journal of Arid Land 2013年第3期5卷 275-283页

作者： lora B PERKINS Robert S NOWAK Department of Natural Resource Management South Dakota State UniversityBrookings SD 57007USA Department of Natural Resources & Environmental Science University of NevadaReno NV 89557USA

As invasion science accepts that there is no single causal factor for biological invasion, the identification of groups of traits that are often associated, or ＂syndromes＂, is a logical move forward. Invasion syndromes are proposed to identify suites of site conditions （biotic and environmental） that render a site vulnerable to invasion by different types of invaders. This paper proposed four invasion syndromes which relate invader attributes （competitive ability, niche construction, phenotypic plasticity, and phenological niche separation） to the biotic characteristics （biodiversity and enemies） and environmental conditions （resource abundance and fluctuation） of invaded sites. The four invasion syndromes described in this paper are a development of hypotheses of how the many factors that influence species invasion might be associated. Invasion Syndrome 1 proposes that sites with relatively high resource abundance and high diversity should be vulnerable to invasion by species with high competitive ability. Invasion Syndrome 2 hypothesizes that sites with relatively low resource abundance and low diversity should be vulnerable to invasion by species with niche construction ability. Invasion Syndrome 3 postulates that sites with moderate or fluctuating resources and moderate diversity should be vulnerable to invasion by species with high phenotypic plasticity. Invasion Syndrome 4 hypothesizes that species introduced into a site where it has phenological niche separation from natives will not have to contend with interference from the biotic community at a site （diversity or natural enemies） and may invade where ever site environmental conditions suit its life history. Further work is needed to support, contradict, or refine these hypotheses and almost certainly will identify more invasion syndromes.

关键词： non-native competitive ability niche construction ecosystem engineering phenotypic plasticity phenological niche separation

A New Approach to Nonlinear Partial Differential Equations

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Communications in Nonlinear Science and Numerical Simulation 1997年第4期2卷 230-235页

作者： Jihuan HE (Shanghai University,Shanghai Institute of Applied Mathematics and Mechanics,Shanghai 2 0 0 0 72 ,China) Shanghai University Shanghai Institute of Applied Mathematics and Mechanics Shanghai 200072 China

In this paper,a novel method called variational iteration method is proposed to solve nonlinear partial differential equations without linearization or small *** this method,a correction functional is constructed by a general Lagrange multiplier,which can be identified via variational *** analytical solution can be obtained from its trial- function with possible unknown constants,which can be identified by imposing the boundary conditions,by successively iteration.

关键词： Nonlinear Problems Partial Differential Equations Variational Iteration Method Variational Theory

Valued Gabriel quiver of a wedge product and semiprime coalgebras

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Frontiers of Mathematics in China 2013年第5期8卷 1157-1183页

作者： Gabriel NAVARR0 Department of Computer Sciences and AI University of Granada E1 Greco s/n E-51002Ceuta Spain

We describe the valued Gabriel quiver of a wedge product of coalgebras and study the category of comodules of a semiprime coalgebra. In particular, we prove that any monomial semiprime k-tame fc-tame coalgebra is string. We also prove a version of Eisenbud-Griffith theorem for coalgebras, namely, any hereditary semiprime strictly quasi-finite coalgebra is serial.

关键词： Wedge product semiprime coalgebras representation theory,valued Gabriel quiver

Variational Iteration Method for Delay Differential Equations

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Communications in Nonlinear Science and Numerical Simulation 1997年第4期2卷 235-236页

The variational iteration method is shown to be applicable to delay differential equations for analytical approximate solutions

关键词： Variational Iteration Method for Delay Differential Equations

Inorganic arsenic： A non-genotoxic carcinogen

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Journal of Environmental Sciences 2016年第11期28卷 28-37页

作者： Samuel M.Cohen Aparajita Chowdhury lora L.Arnold Department of Pathology and Microbiology University of Nebraska Medical Center Omaha NE 68198-3135 USA.

Inorganic arsenic induces a variety of toxicities including cancer. The mode of action for cancer and non-cancer effects involves the metabolic generation of trivalent arsenicals and their reaction with sulfhydryl groups within critical proteins in various cell types which leads to the biological response. In epithelial cells, the response is cell death with consequent regenerative proliferation. If this continues for a long period of time, it can result in an increased risk of cancer. Arsenicals do not react with DNA. There is evidence for indirect genotoxicity in various in vitro and in vivo systems, but these involve exposures at cytotoxic concentrations and are not the basis for cancer development. The resulting markers of genotoxicity could readily be due to the cytotoxicity rather than an effect on the DNA itself. Evidence for genotoxicity in humans has involved detection of chromosomal aberrations, sister chromatid exchanges in lymphocytes and micronucleus formation in lymphocytes, buccal mucosal cells, and exfoliated urothelial cells in the urine. Numerous difficulties have been identified in the interpretation of such results, including inadequate assessment of exposure to arsenic, measurement of micronuclei, and potential confounding factors such as tobacco exposure, folate deficiency, and others. Overall, the data strongly supports a non-linear dose response for the effects of inorganic arsenic. In various in vitro and in vivo models and in human epidemiology studies there appears to be a threshold for biological responses, including cancer.

关键词： Arsenic Cancer Genotoxicity Cytotoxicity Regeneration Cell proliferation

Studying Formability Limits By Combining Conventional and Incremental Sheet Forming Process

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Chinese Journal of Mechanical Engineering 2021年第4期34卷 78-89页

作者： Fabio Andre lora Daniel Fritzen Ricardo Alves de Sousa Lirio Schaffer Department of Materials Engineering Federal University of Recôncavo da BahiaCampus CETENSFeira de SantanaBahia 44085-132Brazil SATC Uni-versity CriciumaBrazil Center of Mechanical Technology and Automation Department of Mechanical EngineeringUniversity of Aveiro3810-193 AveiroPortugal Federal University of Rio Grande do Sul Porto AlegreBrazil

In this work it is assessed the potential of combining conventional and incremental sheet forming processes in a same sheet of *** so-called hybrid forming approach is performed through the manufacture of a pre-forming by conventional forming,followed by incremental sheet *** main objective is analyzing strain *** pre-forming induced in the conventional forming stage will determine the strain paths,directly influencing the strains produced by the incremental *** conduct the study,in the conventional processes,strains were imposed in three different ways with distinct true *** the incremental stage,the pyramid strategy was adopted with different wall *** the experiments,the true strains and the final geometries were *** simulation was also employed for the sake of comparison and correlation with the measured *** could be observed that single-stretch pre-strain was directly proportional to the maximum incremental strains achieved,whereas samples subjected to biaxial pre-strain influenced the formability according to the degree of pre-strain ***-strain driven by the prior deep-drawing operation did not result,in this particular geometry,in increased formability.

关键词： Hybrid forming process Incremental sheet forming Strain paths Numerical simulation

Numerical simulations for G-Brownian motion

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Frontiers of Mathematics in China 2016年第6期11卷 1625-1643页

作者： Jie YANG Weidong ZHA0 School of Mathematics & Finance Institute Shandong University Jinan 250100 China

This paper is concerned with numerical simulations for the G- Brownian motion （defined by S. Peng in Stochastic Analysis and Applications, 2007, 541-567）. By the definition of the G-normal distribution, we first show that the G-Brownian motions can be simulated by solving a certain kind of Hamilton-Jacobi-Bellman （HJB） equations. Then, some finite difference methods are designed for the corresponding HJB equations. Numerical simulation results of the G-normal distribution, the G-Brownian motion, and the corresponding quadratic variation process are provided, which characterize basic properties of the G-Brownian motion. We believe that the algorithms in this work serve as a fundamental tool for future studies, e.g., for solving stochastic differential equations （SDEs）/stochastic partial differential equations （SPDEs） driven by the G-Brownian motions.

关键词： Nonlinear expectation G-Brownian motion G-normal distribu- tion Hamilton-Jacobi-Bellman (HJB) equation

Projected area and drag coefficient of high velocity irregular fragments that rotate or tumble

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Defence Technology（防务技术） 2017年第4期13卷 269-280页

作者： John F. Moxnes 0yvind Fr0 yland Ivar J. 0ye Tom I. Brate Eva Friis Gard 0degardstuen Tallak H. Risdal Norwegian Defence Research Establishment Land Systems Division P.O. Box 25 2027 Kjeller Norway Nammo Raufoss AS P.O. Box 162 2831 Raufoss Norway HPVisTech AS Bj0rnstadgutua 21 2092 Minnesund Norway

3 degrees of freedom(DOF)exterior ballistic computer models are used in fragment studies to calculate individual trajectories of each fragment based on drag coefficient and the projected(presented)area in the direction of velocity of center of *** expectation of a randomly distributed projected area is commonly used for fragments that tumble(random rotation)during *** forecast a model where the expected drag coefficient is dependent of shape and Mach *** or tumbling only affects the expected projected *** of projected areas during tumbling and rotation are *** examination of the data by Mc Cleskey(1988)indicates that the volume of the fragment to the power of2/3 is a better parameter to characterize the drag coefficient of the fragments than the maximum projected *** simulations are used to verify results and to study projected area and drag coefficient of fragments.

关键词： Fragments Form factor Mach number Drag coefficient Cauchy area Tumbling

Lattice-Boltzmann Models for Heat Transfer

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Communications in Nonlinear Science and Numerical Simulation 1997年第4期2卷 212-216页

作者： Chenghai SUN,Zujun XU,Baoguo WANG &Mengyu SHEN (Dept. of Engineering Mechanics,Tsing- hua University,Beijing,1 0 0 0 84) Department of Engineering Mechanics Tsinghua University Beijing 100084 China

A multispeed heat transfer lattice Boltzmann model is presented. The model possesses the perfect gas state equation with arbitrary special heat ratio. The macroscopic conservation equations are derived by the Chapman- Enskog *** one dimensional simulation for the sinusoidal energy distributions are compared with the theoretical results, showing good *** theoretical conductivity in the energy equation is in accordance with the simulations.

关键词： Lattice Boltzmann heat transfer perfect gas