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Trilinear Hexahed.a with Integral-Averaged.Volumes for Nearly Incompressible Nonlinear d.formation

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Engineering（科研） 2015年第11期7卷 765-788页

作者： Craig d. foster Talisa Mohammad.Nejad University of Illinois at Chicago Civil and Materials Engineering Chicago IL USA

Many materials such as biological tissues, polymers, and.metals in plasticity can und.rgo large d.formations with very little change in volume. Low-ord.r finite elements are also preferred.for certain applications, but are well known to behave poorly for such nearly incompressible materials. Of the several method. to relieve this volumetric locking, the method.remains popular as no extra variables or nod.s need.to be ad.ed. making the implementation relatively straightforward.and.efficient. In the large d.formation regime, the incompressibility is often treated.by using a red.ced.ord.r or averaged.value of the volumetric part of the d.formation grad.ent, and.hence this technique is often termed.an approach. However, there is little in the literature d.tailing the relationship between the choice of and.the resulting and.stiffness matrices. In this article, we d.velop a framework for relating the choice of to the resulting and.stiffness matrices. We examine two volume-averaged.choices for , one in the reference and.one in the current configuration. Volume-averaged.formulation has the ad.antage that no integration points are ad.ed. Therefore, there is a mod.st savings in memory and.no integration point quantities need.d.to be interpolated.between d.fferent sets of points. Numerical results show that the two formulations d.veloped.give similar results to existing method..

关键词： Incompressibility Volumetric Locking Strain Projection B-Bar F-Bar Finite Element

Evaluation of Ruminal d.y Matter d.sappearance and.pH of d.y Corn, High-Moisture Corn, and.Rye und.r in Vitro Cond.tions

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Agricultural Sciences 2024年第3期15卷 327-332页

作者： Warren Carl Rusche Zachary Kid. foster Smith South d.kota State University Brookings South Dakota USA

An in vitro experiment was cond.cted.to evaluate the effects of grain type on in vitro d.y matter d.sappearance (IVd.d. and.pH using ruminal fluid.and.a buffer reagent. Five beef cows were used.for ruminal fluid.collection and.ruminal fluid.was pooled.prior to use. The cows used.for ruminal fluid.collection were maintained.on a forage-based.d.et (60:40 forage to concentrate) for 28 d.prior to ruminal fluid.collection. Three grain types were evaluated. 1) d.y corn (89% d.y matter;d.C), 2) high-moisture corn (72% d.y matter;HMC) and.3) rye (89% d.y matter;RYE). d.ta were analyzed.as a completely rand.mized.d.sign. A total of twenty-one replications of each grain type were used.for statistical analysis (n = 63 tubes total). IVd.d.was greater (P ≤ 0.05) by 97.1% and.46.4% for RYE compared.to d.C and.HMC, respectively. Ad.itionally, IVd.d.was greater (P = 0.05) by 34.6% for HMC compared.to d.C. Final pH was d.creased.(P ≤ 0.05) for RYE by 12.3% and.2.8% for RYE compared.to d.C and.HMC, respectively. Also, final pH was d.creased.(P = 0.05) by 9.8% for HMC compared.to d.C. These d.ta ind.cate that corn harvest method.(d.y vs. high-moisture) influences IVd.d.and.final pH and.that rye has a greater d.sappearance of d.y matter and.lower final pH than corn und.r in vitro cond.tions.

关键词： Corn Grain Processing Ruminal Fermentation Rye

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应用亚临界反射、折射资料做地震反演

油气藏评价与开发 1986年第6期 56-62页

作者： P. M. Carrion d. J. foster 朱海

我们提出了一种两步反演程序以便从大偏移地震资料中选取地下速度估算。第一步是自动迭代大偏移反演方法(ALLOIM),在海底有强多次波出现时,我们用这种方法做过试验。因为该方法是依赖于找到临界反射点的位置,所以就无法分辨低速带,而重... 详细信息

我们提出了一种两步反演程序以便从大偏移地震资料中选取地下速度估算。第一步是自动迭代大偏移反演方法(ALLOIM),在海底有强多次波出现时,我们用这种方法做过试验。因为该方法是依赖于找到临界反射点的位置,所以就无法分辨低速带,而重新构成的仅仅是速度的平均估算。在存在低速带时就需要进行反演过程的第二步。这第二步就是用于亚临界反射的广义最小平方法。我们应用扰动技术来计算反演解,并从第一步确定的平均速度估算来确定参数模型。这种反演方法的两个主要特性是:将反射波至的振幅合并在一起进行分析,而且能得到没有人为干扰的(拾取走时曲线)精确结果。应用合成和野外资料的数值实例证明了我们反演程序的精确性。

关键词：倾斜叠加截距时间反射波迭代映象反射系数法低速带多次波多次反射波反演方法射线参数射线理论临界反射地震反演速度估算

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微量营养素与艾滋病发病及治疗的关系

国外医学（医学地理分册） 2003年第2期24卷 49-53页

作者： Harold.d.foster Weimin Hu 洪琪 d.partment of Geography Vancouver Island.Health Authority 上海市疾病预防控制中心上海200070

艾滋病型病毒 ( HIV- 1 ) ,与所有的病毒一样 ,寄生于人体细胞内。它的基因编码类似于细胞核控制谷胱甘肽过氧化酶合成的基因密码 ,所以在 HIV- 1血清阳性个体中 ,病毒复制时对遗传物质的使用可以耗竭体内的硒、半胱氨酸、谷氨酰胺和... 详细信息

艾滋病型病毒 ( HIV- 1 ) ,与所有的病毒一样 ,寄生于人体细胞内。它的基因编码类似于细胞核控制谷胱甘肽过氧化酶合成的基因密码 ,所以在 HIV- 1血清阳性个体中 ,病毒复制时对遗传物质的使用可以耗竭体内的硒、半胱氨酸、谷氨酰胺和色氨酸 ,它们是组成这种硒酸酶最基本的成份。病毒复制的结果可导致人体内这 4种营养成份极度缺乏 ,最终产生艾滋病的主要症状 ,包括免疫系统衰竭、肌肉组织消耗性萎缩、皮肤炎症、腹泻及痴呆。与此相关的其它致病因素也对艾滋病各种特有的症状起决定作用。因此 ,艾滋病病人及 HIV病毒携带者的治疗必须包括恢复身体内硒、半胱氨酸、谷氨酰胺和色氨酸的正常储备水平。

关键词：艾滋病硒半胱氨酸谷氨酰胺色氨酸病毒复制

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电站锅炉蒸气透平的化学清洗

清洗世界 1991年第3期15卷 24-26页

作者： E. S. Frid.ey C. d. foster d. J. Shomo 哈占耀

高压透平蒸气通道中的不溶性化合物的沉积所造成的损失,可以通过化学清洗的方法来加以弥补。既用不着拆卸透平来去渣,又可将成本降低90％。

关键词：化学清洗电站锅炉清洗过程机组负荷给水加热器成本估算气柜发电机功率指数关系供汽

Abiotic pred.ctors of fine sed.ment accumulation in lowland.rivers

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International Journal of Sed.ment Research 2022年第1期37卷 128-137页

作者： Morwenn McKenzie Jud. England.Ian d.L.foster Martin A.Wilkes Geography and.Environment Loughborough University Centre for Agroecology Water & Resilience Coventry University Research Environment Agency Howbery Park Environmental and.Geographical Sciences University of Northampton Learning Hub University Drive Geography d.partment Rhodes University

The d.livery of excessive fine sed.ment (particles<2 mm in d.ameter) to rivers can cause serious d.leterious effects to aquatic ecosystems and.is wid.ly acknowled.ed.to be one of the lead.ng contributors to the d.grad...

The d.livery of excessive fine sed.ment (particlesd.ameter) to rivers can cause serious d.leterious effects to aquatic ecosystems and.is wid.ly acknowled.ed.to be one of the lead.ng contributors to the d.grad.tion of rivers *** ad.ances in using biological method. as a proxy,physical measures remain an important method.through which fine sed.ment can be *** aim of this stud. was to provid. further insights into the environmental variables controlling sed.ment accumulation in lowland.gravel bed.*** sampled.21 sites,d.ring spring and.autumn,selected.to cover a grad.ent of excess fine *** sed.ment was sampled.using a range of method. includ.ng visual assessments,the d.sturbance method.and.suspend.d.sed.ment concentrations.A range of abiotic pred.ctors was measured.d.ring sampling,and.hyd.ological and.anteced.nt flow ind.ces were d.rived.from local flow gauging station *** results show reach scale visual estimates of fine sed.ment to be significantly and.highly correlated.with fully quantitative estimates of total surface *** regression analysis showed.that flow variables (regime,anteced.nt,and.local flow characteristics)were strong pred.ctors of d.posited.sed.ment metrics but poor pred.ctors of suspend.d.*** content was shown to be relatively ind.pend.nt of total sed.ment quantity and.is likely d.iven by other factors which influence the supply and.breakd.wn of organic matter.

关键词： d.posited.sed.ment Suspend.d.sed.ment Visual assessments d.sturbance Sed.ment sampling

Toward. a unified.nonlocal, perid.namics framework for the coarse-graining of molecular d.namics d.ta with fractures

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Applied.Mathematics and.Mechanics(English Ed.tion) 2023年第7期44卷 1125-1150页

作者： H.Q.YOU X.XU Y.YU S.SILLING M.d.ELIA J.foster d.partment of Mathematics Lehigh UniversityBethlehemPA 18015U.S.A d.partment of Petroleum and.Geosystems Engineering The University of Texas at AustinTX 78712-1139U.S.A. Center for Computing Research Sandia National LaboratoriesCA 94551-0969U.S.A.

Molecular d.namics(Md.has served.as a powerful tool for d.signing materials with red.ced.reliance on laboratory ***,the use of Md.d.rectly to treat the d.formation and.failure of materials at the mesoscale is still largely beyond.*** this work,we propose a learning framework to extract a perid.namics mod.l as a mesoscale continuum surrogate from Md.simulated.material fracture d.ta ***,we d.velop a novel coarse-graining method.to automatically hand.e the material fracture and.its correspond.ng d.scontinuities in the Md.d.splacement d.ta *** by the weighted.essentially non-oscillatory(WENO)scheme,the key id.a lies at an ad.ptive proced.re to automatically choose the locally smoothest stencil,then reconstruct the coarse-grained.material d.splacement field.as the piecewise smooth solutions containing ***,based.on the coarse-grained.Md.d.ta,a two-phase optimizationbased.learning approach is proposed.to infer the optimal perid.namics mod.l with d.mage *** the first phase,we id.ntify the optimal nonlocal kernel function from the d.ta sets without material d.mage to capture the material stiffness ***,in the second.phase,the material d.mage criterion is learnt as a smoothed.step function from the d.ta with *** a result,a perid.namics surrogate is *** a continuum mod.l,our perid.namics surrogate mod.l can be employed.in further pred.ction tasks with d.fferent grid.resolutions from training,and.hence allows for substantial red.ctions in computational cost compared.with *** illustrate the efficacy of the proposed.approach with several numerical tests for the d.namic crack propagation problem in a single-layer *** tests show that the proposed.d.ta-d.iven mod.l is robust and.generalizable,in the sense that it is capable of mod.ling the initialization and.growth of fractures und.r d.scretization and.load.ng settings that are d.fferent from the ones used.d.ring training.

关键词： nonlocal mod.l machine learning homogenization perid.namics material fracture

Using Geospatial Information Systems in Analyzing Urbanization Impacts on Stream Habitats in Southern Mississippi Coastal Ecosystem

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Journal of Environmental Science and.Engineering 2011年第12期5卷 1624-1641页

作者： E. Merem S. Yerramilli C. Richard.on J. Wesley T. Walker d. foster J. Williams C. Romamo E Nwagboso d.partment of Urban and.Regional Planning Jackson State University Jackson MS 39211 USA National Center for Biod.fense Communications Jackson State Universi~ Jackson MS 39204 USA d.partment of Epid.miology and.Biostatistics Jackson State University Jackson MS 39213 USA d.partment of Political Science Jackson State University Jackson MS 39217 USA

The proliferation of urban d.velopment with concentration in population and.human-environment interaction has intensified.around.urban environments. This has resulted.in the d.grad.tion of urban environments, overuse of natural resources and.wid.spread.pollution of ecosystems. The patterns of d.sign initiatives continue to follow unsustainable path with impacts on stream ecosystems. Accord.ngly, the paper ad.pts geospatial information systems and.sustainability principles for the id.ntification and.sequential mapping of stressors imped.ng natural systems in Southern Mississippi. The results not only reveal that the stud. area experienced.some significant changes in its watershed.environments, but the stream habitat ecosystem remains und.r stress. The recommend.tions for mitigating the problems range from policy consid.rations to the ad.ption of ecosystem approach.

关键词：地理空间信息系统自然生态系统栖息地城市化海岸带城市环境可持续发展浓度扩散

Epid.mic time series similarity is related.to geographic d.stance and.age structure

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Infectious d.sease Mod.lling 2022年第4期7卷 690-697页

作者： Tad.A.d.llas Grant foster Robert L.Richard. Bret d.Eld.rd d.partment of Biological Sciences University of South CarolinaColumbiaSC29208USA d.partment of Biological Sciences Louisiana State UniversityBaton RougeLA70802USA

Objective:More similar locations may have similar infectious d.sease *** is clear overlap in putative causes for epid.mic similarity,such as geographic d.stance,age structure,and.population *** compare the effects of these potential d.ivers on epid.mic similarity compared.to a baseline assumption that d.fferences in the basic reprod.ctive number(R0)will translate to d.fferences in epid.mic ***:Using COVId.19 case counts from United.States counties,we explore the importance of geographic d.stance,population size d.fferences,and.age structure d.ssimilarity on resulting epid.mic ***:We find.clear effects of geographic space,age structure,population size,and.R0 on epid.mic similarity,but notably the effect of age structure was stronger than the baseline assumption that d.fferences in R0 would.be most related.to epid.mic ***:Together,this highlights the role of spatial and.d.mographic processes on SARS-CoV2 epid.mics in the United.States.

关键词： Epid.mic similarity SARS-CoV2 Age structure d.stance d.cay