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Interaction forces between soft magnetic particles in uniform and non-uniform magnetic fields

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Acta Mechanica Sinica 2010年第6期26卷 921-929页

作者： Ayyoub Mehdizadeh james f.Klausner Nima Rahmatian Department of Mechanical and Aerospace Engineering University of FloridaP.O.Box 116300GainesvilleFL 32611-6300USA

The influence of the magnetization of a soft magnetic sphere on the surrounding magnetic field is measured and *** interaction force between two soft magnetic particles is directly measured using an ultra precision load sensor in uniform and non-uniform magnetic fields. The interaction force largely follows an inverse fourth power law as a function of separation distance between particle centers. At small distances,the effect of magnetization of one particle on the magnetization of its adjacent particle causes the attractive（repulsive） force to be larger（smaller） than that predicted by the inverse fourth power *** theoretical prediction based on a modified dipole model,that takes into account the coupling effect of the magnetization among soft magnetic particles,gives excellent agreement with the measured force in a uniform magnetic *** interaction force under a non-uniform applied magnetic field can be reasonably predicted using the dipole-dipole interaction model when the local magnetic field is used to determine the magnetization.

关键词： Magnetic force Magnetic charge model Magnetic dipole model Soft magnetic particle

Expanding the donor pool: Hepatitis C, hepatitis B and human immunodeficiency virus-positive donors in liver transplantation

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World Journal of Gastroenterology 2019年第47期25卷 6799-6812页

作者： james f Crismale Jawad Ahmad Division of Liver Diseases Icahn School of Medicine at Mount Sinai

Liver transplantation(LT)remains the best option for patients with end-stage liver disease but the demand for organs from deceased donors continues to outweigh the available *** advent of highly effective anti-viral treatments has reduced the number of patients undergoing LT for hepatitis C(HCV)and hepatitis B(HBV)related liver disease and yet the number of patients waiting for LT continues to increase,driven by an increase in the patients listed with a diagnosis of cirrhosis due to non-alcoholic steatohepatitis and alcoholrelated liver *** addition,human immunodeficiency virus(HIV)infection,which was previously a contra-indication for LT,is no longer a fatal disease due to the effectiveness of HIV therapy and patients with HIV and liver disease are now developing indications for *** rising demand for LT is projected to increase further in the future,thus driving the need to investigate potential means of expanding the pool of potential *** mechanism for doing so is utilizing organs from donors that previously would have been discarded or used only in exceptional circumstances such as HCV-positive,HBV-positive,and HIVpositive *** advent of highly effective anti-viral therapy has meant that these organs can now be used with excellent outcomes in HCV,HBV or HIV infected recipients and in some cases uninfected recipients.

关键词： Hepatitis C Hepatitis B Human immunodeficiency virus Liver transplantation

Modeling the Newtonian dynamics for rotation curve analysis of thin-disk galaxies

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Research in Astronomy and Astrophysics 2011年第12期11卷 1429-1448页

作者： james Q.feng C.f.Gallo Superconix Inc 2440 Lisbon AvenueLake ElmoMN 55042USA

We present an efficient, robust computational method for modeling the Newtonian dynamics for rotation curve analysis of thin-disk galaxies. With appropriate mathematical treatments, the apparent numerical difficulties associated with singularities in computing elliptic integrals are completely removed. Using a boundary element discretization procedure, the governing equations are transformed into a linear algebra matrix equation that can be solved by straightforward Gauss elimination in one step without further iterations. The numerical code implemented according to our algorithm can accurately determine the surface mass density distribution in a disk galaxy from a measured rotation curve （or vice versa）. for a disk galaxy with a typical flat rotation curve, our modeling results show that the surface mass density monotonically decreases from the galactic center toward the periphery, according to Newtonian dynamics. In a large portion of the galaxy, the surface mass density follows an approximately exponential law of decay with respect to the galactic radial coordinate. Yet the radial scale length for the surface mass density seems to be generally larger than that of the measured brightness distribution, suggesting an increasing mass-tolight ratio with the radial distance in a disk galaxy. In a nondimensionalized form, our mathematical system contains a dimensionless parameter which we call the ＂galactic rotation number＂ that represents the gross ratio of centrifugal force and gravitational force. The value of this galactic rotation number is determined as part of the numerial solution. Through a systematic computational analysis, we have illustrated that the galactic rotation number remains within 4-10% of 1.70 for a wide variety of rotation curves. This implies that the total mass in a disk galaxy is proportional to V02 Rg, with V0 denoting the characteristic rotation velocity （such as the ＂flat＂ value in a typical ro- tation curve） and Rg the radius of the galacti

关键词： galaxy: disk -- galaxies: general -- galaxies: kinematics and dynamics -- galaxies: structure -- methods: numerical and analytical

Burrowing Richardson's ground squirrels affect plant seedling assemblages via environmental but not seed bank changes

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Current Zoology 2020年第3期66卷 219-226页

作者： Levi J.Newediuk james f.Hare Department of Biological Sciences University of ManitobaWinnipegManitobaCanada R3T 2N2

In grassland ecosystems,burrowing mammals create disturbances,providing habitat for animal species and increasing plant community *** investigated whether seedling assemblages on Richardson's ground squirrel Urocitellus richardsonii mounds result from seed rearrangement or environmental changes that favor germination of certain species over *** test whether ground squirrels rearrange the seed bank by burrowing,we compared seed compositions among mounds,burrows,and undisturbed *** test whether ground squirrels change environmental conditions,we compared soil nitrate and bare ground cover on and off *** also compared seedlings that germinated on mounds with seedlings that germinated on artificial disturbances from which we removed aboveground *** nitrate and bare ground cover were significantly higher on mounds than artificial *** seed richness and abundance did not differ among mounds,burrows,and undisturbed soil,seedling richness was reduced on mounds relative to artificial *** disturbance favors seedlings that can capitalize on bare ground availability but are less able to immobilize nitrate,as opposed to perennial species that immobilize more nitrate but take longer to *** results suggest that Richardson's ground squirrels act as ecosystem engineers,although future research following succession on ground squirrel mounds is necessary to understand how they influence plant communities past the seedling stage.

关键词： burrowing disturbance ecosystem engineering Richardsons ground squirrel seed bank seedling species composition

Perceptual tolerance neighborhood-based similarity in content-based image retrieval and classification

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International Journal of Intelligent Computing and Cybernetics 2012年第2期5卷 164-185页

作者： Amir H.Meghdadi james f.Peters Electrical and Computer Engineering University of ManitobaWinnipegCanada School of Mathematics University of HyderabadHyderabadIndia

Purpose–The purpose of this paper is to demonstrate the effectiveness and advantages of using perceptual tolerance neighbourhoods in tolerance space-based image similarity measures and its application in content-based image classification and ***/methodology/approach–The proposed method in this paper is based on a set-theoretic approach,where an image is viewed as a set of local visual *** method also includes a tolerance relation that detects the similarity between pairs of elements,if the difference between corresponding feature vectors is less than a threshold 2(0,1).findings–It is shown that tolerance space-based methods can be successfully used in a complete content-based image retrieval(CBIR)***,it is shown that perceptual tolerance neighbourhoods can replace tolerance classes in CBIR,resulting in more accuracy and less ***/value–The main contribution of this paper is the introduction of perceptual tolerance neighbourhoods instead of tolerance classes in a new form of the Henry-Peters tolerance-based nearness measure(tNM)and a new neighbourhood-based tolerance-covering nearness measure(tcNM).Moreover,this paper presents a side–by–side comparison of the tolerance space based methods with other published methods on a test dataset of images.

关键词： Image similarity Nearness measure Distance measurement Content-based image retrieval(CBIR) Perceptual tolerance neighbourhoods Tolerance spaces Tolerances Measurement

Design of Poiseuille flow Controllers Using the Method of Inequalities

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International Journal of Automation and computing 2009年第1期6卷 14-21页

作者： John McKernan james f. Whidborne George Papadakis Department of Mechanical Engineering King s College London Strand Department of Aerospace Sciences Cranfield University

This paper investigates the use of the method of inequalities （MoI） to design output-feedback compensators for the problem of the control of instabilities in a laminar plane Poiseuille flow. In common with many flows, the dynamics of streamwise vortices in plane Poiseuille flow are very non-normal. Consequently, small perturbations grow rapidly with a large transient that may trigger nonlinearities and lead to turbulence even though such perturbations would, in a linear flow model, eventually decay. Such a system can be described as a conditionally linear system. The sensitivity is measured using the maximum transient energy growth, which is widely used in the fluid dynamics community. The paper considers two approaches. In the first approach, the MoI is used to design low-order proportional and proportional-integral （PI） controllers. In the second one, the MoI is combined with Mcfarlane and Glover＇s H∞ loop-shaping design procedure in a mixed-optimization approach.

关键词： Transient energy growth transient behaviour flow control Poiseuille flow method of inequalities (MoI) mixed opti-mization H∞-optimization.

In the forest vine Smilax rotundifolia,fungal epiphytes show site-wide spatial correlation,while endophytes show evidence of niche partitioning

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fungal Diversity 2015年第6期75卷 279-297页

作者： Christopher B.Zambell james f.White Graduate Program in Ecology&Evolution Rutgers UniversityNew BrunswickNJ 08901USA Department of Plant Biology&Pathology 59 Dudley RoadNew BrunswickNJ 08901USA

Endophytic and epiphytic fungal assemblages from stems of ***,a shrubby vine,were studied in order to(1)quantify differences and the degree of overlap between fungal communities of both micro-habitats,and(2)examine whether fungal assemblages are spatially correlated at the local scale(tens to hundreds of meters),in order to understand if dispersal limitation may play a role in structuring these *** was conducted over 160 m of growth along a forest *** communities showed low overlap(Bray-Curtis Similarity=0.22),with most species that were common in one habitat appearing rarely if at all in the other,and only Aureobasidium pullulans showing high frequency in *** assemblages proved to be spatially correlated along the 160 m length of the transect,and even more so when adjacent pairs of stems were considered as the unit of comparison rather than individual *** assemblages showed no significant spatial correlation along the ***,three species of endophytes showed a pattern in which abundance of colonies peaked at different heights on the *** boninense showed peak abundance at 3 cm from the stem *** sp.1 peaked at 33 cm from the stem *** isolates of *** peaked at 63 cm from the stem *** was also found that positive correlative relationships were detected between endophyte-endophyte,and epiphyte-epiphyte ***-group interactions seemed to center around crossover species that were not entirely constrained within the surface or interior.

关键词： Colletotrichum Phomopsis Phyllosticta Local dispersal Tissue preference

Semi-transparent,flexible,and electrically conductive silicon mesh by capillarity-driven welding of vapor-liquid-solid-grown nanowires over large areas

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Nano Research 2020年第5期13卷 1465-1471页

作者： Thomas A.Celano Seokhyoung Kim David J.Hill james f.Cahoon Department of Chemistry University of North Carolina at Chapel HillChapel HillNC 27599-3290USA

Bottom-up synthesis of semiconductor nanowires(NWs)by the vapor-liquid-solid(VLS)mechanism has enabled diverse technological applications for these *** metallic NWs,however,it has been challenging to form large-area interconnected NW ***,we generate centimeter-scale meshes of mechanically and electrically interconnected Si NWs by sequentially growing,collapsing,and joining the NWs using a capillarity-driven welding *** fabricate meshes from VLS-grown NWs ranging in diameter from 20 to 100 nm and find that the meshes are three-dimensional with a thickness ranging from^1 to^10 microns depending on the NW *** extinction measurements reveal that the networks are semi-transparent with a color that depends on the absorption and scattering characteristics of individual ***,active voltage contrast imaging of both centimeter-and micron-scale meshes reveals widespread electrical *** a sacrificial layer,we demonstrate that the mesh can be liberated from the growth substrate,yielding a highly flexible and transparent *** transport measurements both on the growth substrate and on liberated,flexible films reveal electrical conduction across a centimeter scale with a sheet resistance of^160-180 kΩ/square that does not change significantly upon *** the ability to encode complex functionality in semiconductor NWs through the VLS process,we believe these meshes of networked NWs could find application as neuromorphic memory,electrode scaffolds,and bioelectronic interfaces.

关键词： semiconductor nanowire conductive network flexible electronics welding thermal annealing active-voltage contrast

Commentary on“Incidence of urinary incontinence following endoscopic laser enucleation of the prostate by en-bloc and non-en-bloc techniques:a multicenter,real-world experience of 5068 patients”

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Asian Journal of Andrology 2024年第3期26卷 333-334页

作者： james f Jiang Narmina K Onder Akhil K Das Department of Urology University of California Irvine Orange CA 92868 USA

Laser enucleation of the prostate is a proven and effectivesize-independent method for the surgical management of symptomaticbenign prostatic hyperplasia(BPH)and is considered as the“goldstandard”by many *** major hurdles that stand in theway of this becoming a universally used procedure for BPH are thesteep learning curve associated with mastering the procedure andpossibility of perioperative transient *** advances inteaching methodologies have helped tackle the difficulty in learning itand increased the number of urologists utilizing the *** forthe second hurdle,transient incontinence rates postlaser enucleationof the prostate have improved with the advent of newer techniques *** et al.1 assesses the incidence of stress,urge,andmixed urinary incontinence following laser enucleation of the prostateby comparing en-bloc and non-en-bloc techniques in a multicenterseries of 5068 men with BPH.

关键词： urinary incontinence transient