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Homogenization of Reynolds Equation by Two-Scale Convergence

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Chinese Annals of Mathematics,Series B 2007年第3期28卷 363-374页

作者： peter wALL Department of Mathematics Lule University of TechnologyS-971 87 Lule Sweden.

To increase the hydrodynamic performance in different machine elements, as e.g. journal bearings and thrust bearings, during lubrication it is important to understand the influence of surface roughness. In this connection one encounters homogenization of the incompressible Reynolds equation, where the roughness of the lubricated surface is assumed to be periodic. This problem has recently been studied in more engineering- oriented papers by using the formal method of multiple scale expansion. In this paper, we rigorously prove both homogenization and corrector results by using two-scale convergence, which may be regarded as a justification of the formal multiple scale expansion method described above. Moreover, some numerical illustrations and results are presented.

关键词： Homogenization Two-scale convergence Reynolds equation Lubrication

Mass spectrometry based proteomics,background,status and future needs

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Protein & Cell 2012年第9期3卷 641-647页

作者： peter Roepstorff Department of Biochemistry and Molecular Biology University of Southern Denmark Campusvej 55DK 5230 Odense MDenmark

An overview of the background for proteomics and a description of the present state of art are given with a description of the main strategies in *** advantages and limitations of the two major strategies,2D-gel based and LC-MS based,are discussed and a combination for the two,CeLC-MS is described.A number of challenging problems which have been solved using different proteomics strategies including the advantage of organell enrichment or modifications specific peptide isolation to get deeper into the proteome are *** the present status and future needs discussed.

关键词： proteomics 2D-PAGE LC-MS isoforms phosphorylation

Non-Achievability of Metal-Insulator Transition in Two-Dimensional Systems

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Chinese Physics Letters 2006年第4期23卷 946-949页

作者： A. John peter Zhejiang Institute of Modern Physics Zhejiang University Hangzhou 310027

we present a simple demonstration of the nonfeasibility of metal-insulator transition in an exactly two-dimensional （2D） system. The Hartree-Fock potential in the 3D system is suitably modified and presented for the 2D case. The many body effects are included in the screening function, and binding energies of a donor are obtained as a function of impurity concentration so as to find out the possible way leading metal-insulator transition in the 2D system. while solving for the binding energy for a shallow donor in an isolated well of a GaAs/Ga1-x Als As superlattice system within the effective mass approximation, it leads to unphysical results for higher concentrations. It shows that the phase transition, the bound electron entering into the conduction band whereby （H）min=0, is not possible beyond this concentration. The results suggest thai a phase transition is impossible in 213 systems, supporting the scaling theory of localization. The results are compared with the existing data available and discussed in the light of existing literature.

关键词： MOTT TRANSITION QUANTUM-wELLS ELECTRON-GAS 2 DIMENSIONS LOCALIZATION

The N-formyl peptide receptors: contemporary roles in neuronal function and dysfunction

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Neural Regeneration Research 2020年第7期15卷 1191-1198页

作者： peter J.G. Cussell Margarita Gomez Escalada Nathaniel G.N. Milton Andrew w.J. Paterson Centre for Biomedical Science Research School of Clinical and Applied Sciences Leeds Beckett University

N-formyl peptide receptors(FPRs)were first identified upon phagocytic leukocytes,but more than four decades of research has unearthed a plethora of non-myeloid roles for this receptor *** are expressed within neuronal tissues and markedly in the central nervous system,where FPR interactions with endogenous ligands have been implicated in the pathophysiology of several neurodegenerative diseases including Alzheimer's disease and Parkinson's disease,as well as neurological cancers such as *** the homeostatic function of FPRs in the nervous system is currently undefined,a variety of novel physiological roles for this receptor family in the neuronal context have been posited in both human and animal *** developments in recent years have implicated FPRs in the process of neurogenesis and neuronal differentiation which,upon greater characterisation,could represent a novel pharmacological target for neuronal regeneration therapies that may be used in the treatment of brain/spinal cord injury,stroke and *** review aims to summarize the recent progress made to determine the physiological role of FPRs in a neuronal setting,and to put forward a case for FPRs as a novel pharmacological target for conditions of the nervous system,and for their potential to open the door to novel neuronal regeneration therapies.

关键词： Alzheimer's disease formyl peptide receptor neural regeneration neuroblastoma neurodegeneration neuroinflammation neuronal differentiation stroke

Assessment of limiting dietary amino acids in broiler chickens offered reduced crude protein diets

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Animal Nutrition 2022年第3期10卷 1-11页

作者： Craig w.Maynard Michael T.Kidd peter V.Chrystal Leon R.McQuade Bernie V.McInerney peter H.Selle Sonia Y.Liu Center of Excellence for Poultry Science University of ArkansasFayettevilleAR72701United States Poultry Research Foundation Faculty of ScienceThe University of Sydney425 Werombi RoadCamdenNSW2570Australia School of Life and Environmental Sciences Faculty of ScienceThe University of SydneySydneyNSW2006Australia Australian Proteome Analysis Facility Macquarie UniversitySydneyNSW2109Australia Sydney School of Veterinary Science Faculty of ScienceThe University of SydneySydneyNSW2006Australia

As lowering crude protein(CP)in poultry diets continues to minimize amino acid excess,it is important to understand the limiting order of amino acids and the impact of their ***,a pair of experiments were conducted to observe the effects of individual amino acid deletions on growth performance,carcass traits,and nutrient *** experiments involved 3 control diets based on wheat and soybean meal,including a 210.0 g/kg CP industry control(IC),186.7 g/kg CP positive control(PC)supplemented with feed-grade amino acids to match the IC amino acid profile,186.7 g/kg CP negative control(NC)with reducing N corrected apparent metabolizable energy(AMEN)by 0.5 MJ/kg and removing feed-grade amino acids beyond L-Lys-HCl,DL-Met,and L-Thr from *** deletion diets where the following supplemented amino acids were individually removed from the PC:Val,Ile,Leu,Trp,Arg,His,Phe t Tyr,glycine equivalence(Glyequi),Pro,and Energy(0.5 MJ/kg reduction in AMEN of the PC).All diets were formulated to contain similar concentrations of digestible Lys,total sulfur amino acid(TSAA)and *** diets were offered to broiler chickens from 15 to 22 d postehatch in a cage study(Exp.1)to gain digestibility and nutrient utilization data;whereas they were offered from 15 to 35 d post ehatch in a floor-pen study(Exp.2)to gain performance and carcass yield *** removal of supplemented Val,Arg,and Ile resulted in reduction on broiler performance(Pwheat-soybean meal diets,but that Ile and Glyequi may potentially limit breast and thigh development.

关键词： Amino acid Broiler chicken Crude protein Low protein diet

Bayesian methods in reporting and managing Australian clinical indicators

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world Journal of Clinical Cases 2015年第7期3卷 625-634页

作者： peter P Howley Stephen J Hancock Robert w Gibberd Sheuwen Chuang Frank A Tuyl School of Mathematical and Physical Sciences\Statistics The University of Newcastle Health Services Research Group Faculty of HealthThe University of Newcastle School of Health Care Administration Health Policy and Care Research CenterTaipei Medical University

Sustained clinical improvement is unlikely without appropriate measuring and reporting techniques. Clinical indicators are tools to help assess whether a standard of care is being met. They are used to evaluate the potential to improve the care provided by healthcare organisations(HCOs). The analysis and reporting of these indicators for the Australian Council on Healthcare Standards have used a methodology which estimates, for each of the 338 clinical indicators, the gains in the system that would result from shifting the mean proportion to the 20 th centile. The results are used to provide a relative measure to help prioritise quality improvement activity within clinical areas, rather than simply focus on "poorer performing" HCOs. The method draws attention to clinical areas exhibiting larger between-HCO variation and affecting larger numbers of patients. HCOs report data in six-month periods, resulting in estimated clinical indicator proportions which may be affected by small samples and sampling variation. Failing to address such issues would result in HCOs exhibiting extremely small and large estimated proportions and inflated estimates of the potential gains in the system. This paper describes the 20 th centile method of calculating potential gains for the healthcare system by using Bayesian hierarchical models and shrinkage estimators to correct for the effects of sampling variation, and provides an example case in Emergency Medicine as well as example expert commentary from colleges based upon the reports. The application of these Bayesian methods enables all collated data to be used, irrespective of an HCO's size, and facilitates more realistic estimates of potential system gains.

关键词： Clinical indicators Improvement System gains Bayesian Statistical models

THE USE OF PLANE wAVES TO APPROXIMATE wAVE PROPAGATION IN ANISOTROPIC MEDIA

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Journal of Computational Mathematics 2007年第3期25卷 350-367页

作者： Tomi Huttunen peter Monk Department of Physics University of KuopioP.O.Box 1627FIN-70211 KuopioFinland Department of Mathematical Sciences University of DelawareNewarkDE 19716USA

In this paper we extend the standard Ultra weak Variational Formulation （UwVF） of Maxwell＇s equations in an isotropic medium to the case of an anisotropic medium. we verify that the underlying theoretical framework carries over to anisotropic media （however error estimates are not yet available） and completely describe the new scheme. we then consider TM mode scattering, show how this results in a Helmholtz equation in two dimensions with an anisotropic coefficient and demonstrate how to formulate the UwVF for it. In one special case, convergence can be proved. we then show some numerical results that suggest that the UwVF can successfully simulate wave propagation in anisotropic media.

关键词： Ultra weak Maxwell Plane wave Anisotropic medium.

FUNCTIONAL POLYHYDROXYALKANOATES SYNTHESIZED BY MICROORGANISMS

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Chinese Journal of Polymer Science 2000年第5期18卷 389-396页

作者： peter H.Yu Open Laboratory of Chiral Technology Hong Kong Polytechnic University Hong Kong China

Many bacteria have been found to synthesize a family of polyesters termed polyhydroxyalkanoate, abbreviated as PHA. Some interesting physical properties of PHAs such as piezoelectricity, non-linear optical activity, biocompatibility and biodegradability offer promising applications in areas such as degradable packaging, tissue engineering and drug delivery. Over 90 PHAs with various structure variations have been reported and the number is still increasing. The mechanical property of PHAs changes from brittle to flexible to elastic, depending on the side-chainlength of PHA. Many attempts have been made to produce PHAs as biodegradable plastics using various microorganisms obtained from screening natural environments, genetic engineering and mutation. Due to the high production cost, PHAs still can not compete with the nondegradable plastics, such as polyethylene and polypropylene. Various processes have been developed using low cost raw materials for fermentation and an inorganic extraction process for PHA purification. However, a super PHA production strain may play the most critical role for any large-scale PHA production. Our recent study showed that PHA synthesis is a common phenomenon among bacteria inhabiting various locations, especially oil-contaminated soils. This is very important for finding a suitable bacterial strain for PHA production. In fact, PHA production strains capable of rapid growth and rapid PHA synthesis on cheap molasses substrate have been found on molasses contaminated soils. A combination of novel properties and lower cost will allow easier commercialization of PHA for many applications.

关键词： polyhydroxybutyrate polyhydroxyalkanoate biopolymer polyester

Adaptive nonlinear model predictive control design of a flexible-link manipulator with uncertain parameters

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Acta Mechanica Sinica 2017年第3期33卷 529-542页

作者： Fabian Schnelle peter Eberhard Institute of Engineering and Computational Mechanics University of Stuttgart

This paper presents a novel adaptive nonlinear model predictive control design for trajectory tracking of flexible-link manipulators consisting of feedback linearization, linear model predictive control, and unscented Kalman filtering. Reducing the nonlinear system to a linear system by feedback linearization simplifies the optimization problem of the model predictive controller significantly, which, however, is no longer linear in the presence of parameter uncertainties and can potentially lead to an undesired dynamical behaviour. An unscented Kalman filter is used to approximate the dynamics of the prediction model by an online parameter estimation, which leads to an adaptation of the optimization problem in each time step and thus to a better prediction and an improved input action. Finally, a detailed fuzzy-arithmetic analysis is performed in order to quantify the effect of the uncertainties on the control structure and to derive robustness assessments. The control structure is applied to a serial manipulator with two flexible links containing uncertain model parameters and acting in three-dimensional space.

关键词： Model predictive control Feedback linearization Unscented Kalman filter Flexible-link manipulator Fuzzy-arithmetical analysis