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Equipartition and retrieval of Green's function

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Earthquake Science 2010年第5期23卷 397-402页

作者： Richard L.weaver Department of Physics University of Illinois

Physical and mathematical arguments are presented for equipartition as the statistical state achieved by a ran- dom field, independent of its sources, in the limit of enough scattering. The arguments are simplest for the case of thermally excited fields, but are shown to apply also, with caveats, in non-equilibrium acoustics and seismology. Practical implications are discussed.

关键词： noise correlation equipartition elastic waves information entropy

Re-engineering artificial muscle with microhydraulics

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Microsystems & Nanoengineering 2017年第1期3卷 278-285页

作者： Jakub Kedzierski Eric Holihan Rafmag Cabrera Isaac weaver Massachusetts Institute of Technology Lincoln Laboratory LexingtonMA 02420USA

We introduce a new type of actuator,the microhydraulic stepping actuator(MSA),which borrows design and operational concepts from biological muscle and stepper *** offer a unique combination of power,efficiency,and scalability not easily achievable on the *** actuator works by integrating surface tension forces produced by electrowetting acting on scaled droplets along the length of a thin *** muscle,MSAs have liquid and solid functional components and can displace a large fraction of their *** 100μm pitch MSA presented here already has an output power density of over 200 W kg^(−1),rivaling the most powerful biological muscles,due to the scaling of surface tension forces,MSA’s power density grows quadratically as its dimensions are reduced.

关键词： artificial muscle electrowetting linear actuator microactuator microsystem microhydraulic stepping actuator

Functional diversity of small-mammal postcrania is linked to both substrate preference and body size

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Current Zoology 2020年第5期66卷 539-553页

作者： Lucas N.weaver David M.Grossnickle Department of Biology Life Sciences BuildingUniversity of WashingtonSeattleWA 98195USA

Selective pressures favor morphologies that are adapted to distinct ecologies,resulting in trait partition!ng among ***,the effects of these selective pressures vary across taxa,especially because morphology is also influenced by factors such as phylogeny,body size,and functional *** this study,we examine how these factors impact functional diversification in *** has been proposed that trait partitioning among mammalian ecomorphotypes is less pronoun ced at small body sizes due to biomecha nical,energetic,and environ mental factors that favor a"generalist"body plan,whereas larger taxa exhibit more substantial functional *** title this the Diverge nee Hypothesis(DH)because it predicts greater morphological divergence among ecomorphotypes at larger body *** test DH by using phylogenetic comparative methods to examine the postcranial skeletons of 129 species of taxonomically diverse,small-tomedium-sized(<15 kg)mammals,which we categorize as either"tree-dwellers"or"ground-dwellers."In some analyses,the morphologies of ground-dwellers and tree-dwellers suggest greater between-group differentiation at larger sizes,providing some evidence for ***,this trend is n either particularly strong nor supported by all an *** stead,a more pronoun ced patter n emerges that is distinct from the predictions of DH:within-group phenotypic disparity increases with body size in both ground-dwellers and tree-dwellers,driven by morphological outliers among"medium'-sized ***,evolutionary increases in body size are more closely linked to increases in within-locomotor-group disparity tha n to in creases in betwee n-group *** discuss biomechanical and ecological factors that may drive these evolutionary patter ns,and we emphasize the significant evolutionary influences of ecology and body size on phenotypic diversity.

关键词： adaptive landscapes ecomorphology morphometries phenotypic diversity phylogenetic comparative methods trait partitioning

Effect of ceria surface facet on stability and reactivity of isolated platinum atoms

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Nano Research 2022年第7期15卷 5922-5932页

作者： Bochuan Song Shuxin Si Asiye Soleymani Yan Xin Helena E.Hagelin-weaver Department of Chemical Engineering University of FloridaGainesville 32611USA National High Magnetic Field Laboratory Florida State UniversityTallahassee 32310USA

Well-defined surface structures and uniformity are key factors in exploring structure–activity relationships in heterogeneous catalysts.A modified atomic layer deposition method and three well-defined CeO_(2) nanoshapes,octahedra with(111)surfaces,cubes exposing(100)facets,and rods with(100)and(110)surface facet terminations,were utilized to synthesize ultra-low loading Pt/CeO_(2) catalysts and allow investigations on the influence of ceria surface facet on isolated Pt species under reducing conditions.A mild reduction temperature(150℃)reduces the initial platinum ions present on the surfaces of the ceria support but preserves the isolated Pt atoms on all ceria surface *** contrast,a reduction temperature of 350°C,reveals very different interactions between the initial single Pt atoms and the various ceria surface facets,leading to dissimilar and nonuniform Pt ensembles on the three ceria *** isolate facet dependent Pt–CeO_(2) interactions and avoid variations between Pt species,the Pt1/CeO_(2) catalysts after reduction at 150°C were subjected to CO oxidation *** isolated Pt atoms on the CeO_(2) octahedra and cubes are less active in the CO oxidation reaction,compared with Pt on CeO_(2) *** the case of Pt on the CeO_(2) octahedra this is due to strongly bound CO blocking active sites together with a stable CeO_(2)(111)surface limiting the oxygen supply from the *** the CeO_(2) cubes,some Pt is not available for reaction and CO is bound strongly on the available Pt *** addition,the Pt catalysts supported on the CeO_(2) cubes are not stable with time on *** isolated Pt atoms on the CeO_(2) rods are considerably more active under these conditions and this is due to a weaker Pt–CO bond strength and more facile reverse oxygen spillover from the defect-rich(110)surfaces of the rods due to the lower energy of oxygen vacancy formation on this CeO_(2) *** Pt supported on the CeO_(2) rods is also remarkably stable with t

关键词： single atom catalyst CeO_(2)shapes facet effects Pt1/CeO_(2) diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)

Amino acid fortified diets for weanling pigs replacing fish meal and whey protein concentrate:Effects on growth,immune status,and gut health

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Journal of Animal Science and Biotechnology 2015年第3期6卷 330-339页

作者： Yan Zhao Alexandra C weaver Vivek Fellner Robert L Payne Sung Woo Kim Department of Animal Science North Carolina State University Evonik Corp

Background： Limited availability of fish meal and whey protein concentrate increases overall feed costs. Availability of increased number of supplemental amino acids including Lys, Met, Thr, Trp, Val, and lie allows replacing expensive protein supplements to reduce feed costs. This study was to evaluate the effect of replacing fish meal and/or whey protein concentrate in nursery diets with 6 supplemental amino acids on growth performance and gut health of post-weaning pigs. Treatments were 1） FM-WPC： diet with fish meal （FM） and whey protein concentrate （WPC）; 2） FM-AA： diet with FM and crystalline amino acids （L-Lys, L-Thr, L-Trp, DL-Met, L-Val, and L-lie）; 3） WPC-AA： diet with WPC and crystalline amino acid; and 4） AA： diet with crystalline amino acid. Results： Pigs in FM-AA, WPC-AA, and AA had greater （P 〈 0.0.5） ADG and gain：feed than pigs in FM-WPC during wk ] （phase 1）. Plasma insulin concentration of pigs in AA tended to be greater （P = 0.064） than that of FM-WPC at the end of wk 1 （phase 1）. Plasma concentrations of IgG in AA was lower （P 〈 0.05） compared with WPC-AA and FW, and FM-AA had lower （P 〈 0.05） IgG concentration than WPC-AA at the end of wk 1 （phase 1）. Concentration of acetate in cecum digesta in FM-AA tended to be greater （P = 0.054） than that of FM-WPC and WPC-AA. Concentration of isovalerate in cecum digesta of pigs in FM-AA was greater （P 〈 0.05） than that of FW and WPC-AA. Conclusions： This study indicates that use of 6 supplemental amino acids can replace fish meal and/or whey protein concentrate without adverse effects on growth performance, immune status, and gut health of pigs at d 21 to 49 of age. Positive response with the use of 6 supplemental amino acids in growth during the first week of post-weaning may due to increased plasma insulin potentially improving uptake of nutrients for protein synthesis and energy utilization. The replacement of fish meal and/or whey protein concentrate with 6 supplemental amino acids could decrease the

关键词： Amino acid Fish meal Growth performance Pig Whey protein concentrate

Improving efficiency of sow productivity: nutrition and health

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Journal of Animal Science and Biotechnology 2013年第3期4卷 187-194页

作者： Sung Woo Kim Alexandra C weaver Yan Bin Shen Yan Zhao Department of Animal Science North Carolina State UniversityNorth Carolina Raleigh 27695 USA

This reviews research focused to understand the nutrient requirement and balance to meet the needs of fetal growth,mammary growth,and milk *** summary will handle how feeding strategies can be adjusted according to the nutrient needs for a sow to enhance productivity and *** research data used in this summary are based on the studies conducted by the authors between 1996 and *** requirements of sows are affected by stage of gestation and parity of *** antioxidant concentrations need to be re-evaluated for its sufficiency in sow diets especially to prevent excessive oxidative stress during late gestation and *** feeding sows,consideration of phase feeding of gestating sows and parity feeding of lactating sows could enhances production longevity and health of *** of selected nutrients and additives seems to help productivity and health of sows.

关键词： Colostrum Gestation Lactation Milk Nutrition Pig

Loving her into well-being one day at a time: Narratives of caring for daughters with eating disorders

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Open Journal of Nursing 2012年第4期2卷 406-419页

作者： Kathryn weaver Faculty of Nursing University of New Brunswick Fredericton Canada

When a child is diagnosed with an eating disorder, parents are expected to help the child recover. Yet, parents often feel under-prepared and alone, their experiences inadequately known to healthcare professionals. The research aim was to examine the meaning to parents of caring for a child with an eating disorder. Qualitative interviews with 29 parents were analyzed and the parents’ experiences were represented by a collective story of loving her into well-being one day at a time which consisted of two themes: Running on nerves and caring through transformational activism. Running on nerves included threads of feeling lost, traumatized, scarred, and disengaged that mitigated as parents engaged in transformational activism processes directed toward helping themselves, their child, and other parents and children. The findings illustrate the importance of hearing parents’ stories in order to create supportive healing environments and to build capacity within families and health care systems.

关键词： Eating Disorder Parents Narrative Analysis Transformational Activism

The Traveling Wave Reactor: Design and Development

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Engineering 2016年第1期2卷 88-96页

作者： John Gilleland Robert Petroski Kevan weaver Terra Power LLC

The traveling wave reactor （TWR） is a once-through reactor that uses in situ breeding to greatly reduce the need for enrichment and reprocessing. Breeding converts incoming subcritical reload fuel into new critical fuel, allowing a breed-burn wave to propagate. The concept works on the basis that breed-burn waves and the fuel move relative to one another. Thus either the fuel or the waves may move relative to the stationary observer. The most practical embodiments of the TWR involve moving the fuel while keeping the nuclear reactions in one place-sometimes referred to as the standing wave reactor （SWR）. TWRs can operate with uranium reload fuels including totally depleted uranium, natural uranium, and low-enriched fuel （e.g., 5.5% 23sU and below）, which ordinarily would not be critical in a fast spectrum. Spent light water reactor （LWR） fuel may also serve as TWR reload fuel. In each of these cases, very efficient fuel usage and significant reduction of waste volumes are achieved without the need for re- processing. The ultimate advantages of the TWR are realized when the reload fuel is depleted uranium, where after the startup period, no enrichment facilities are needed to sustain the first reactor and a chain of successor reactors. TerraPower＇s conceptual and engineering design and associated technolo- gy development activities have been underway since late 2006, with over 50 institutions working in a highly coordinated effort to place the first unit in operation by 2026. This paper summarizes the TWR technology： its development program, its progress, and an analysis of its social and economic benefits.

关键词： Nuclear energyElectricity generationAdvanced reactorTraveling wave reactorSustainability

Enhanced cortical bone expansion in Lgals3-deficient mice during aging

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Bone Research 2018年第1期6卷 95-106页

作者： Kevin A.Maupin Kevin weaver Alexis Bergsma Cheryl Christie Zhendong A.Zhong Tao Yang Bart O.Williams Center for Cancer and Cell Biology Program for Skeletal Disease and Tumor Microenvironment Van Andel Research Institute

Imbalances between bone formation and bone resorption, which can occur due to aging or sex hormone deprivation, result in decreased bone mass and an increased risk of fracture. Previous studies have suggested that the β-galactoside binding lectin,galectin-3, is involved in bone remodeling. We compared bone parameters of mice having null alleles of the galectin-3 gene(Lgals3-KO) with those of their wild-type littermates. Lgals3 deficiency increased cortical bone expansion at 36 weeks(wk) and preserved or enhanced bone mass in both male and female mutant mice. In addition, female Lgals3-KO mice were protected from age-related loss of trabecular bone. Histomorphometry and ex vivo primary cell differentiation assays showed increased osteoblastogenesis with little-to-no effect on osteoclastogenesis, suggesting the increased bone mass phenotype is primarily due to increased anabolism. Our study identifies galectin-3 as a negative regulator of bone formation and suggests that disruption of galectin-3 may be useful in preventing bone loss during aging.

关键词： Lgals3-KO their wild-type Histomorphometry