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Frictional shear stress of ZnO nanowires on natural and pyrolytic graphite substrates

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Friction 2022年第12期10卷 2059-2068页

作者： Lizhen HOU Maofen HOU Tursunay YIBIBULLA james Lee MEAd Sergej FATIKOW Shiliang WANG Han HUANG Key Laboratory of Low-dimensional Quantum Structures and Quantum Control of Ministry of Education School of Physics and Electronic ScienceHunan Normal UniversityChangsha 410081China School of Physics and Electronics Central South UniversityChangsha 410083China division Microrobotics and Control Engineering Department of Computing ScienceUniversity of OldenburgOldenburg D-26129Germany School of Mechanical and Mining Engineering The University of QueenslandBrisbaneQLD 4072Australia

The friction behaviour of ZnO nanowires on natural graphite(NG)and highly oriented pyrolytic graphite(HOPG)substrates was tested in ambient conditions by use of optical microscopy based *** on the step-free and waviness-free NG substrate exhibit a diameter-independent nominal frictional shear stress of 0.48 MPa,and this provides a benchmark for studying how the surface topography of graphite influences nanowire *** on the HOPG substrate present a significant diameter-dependent frictional shear stress,increasing from 0.25 to 2.78 MPa with the decrease of nanowire diameter from 485 to 142 *** waviness of HOPG has a limited effect on the nanowire friction,as a nanowire can fully conform to the *** surface steps on the HOPG can significantly enhance the nanowire friction and lead to a much higher frictional shear stress than that on NG due to mechanical blocking and the presence of a Schwoebel barrier at step *** surface steps,however,can also generate small wedge-shaped gaps between a nanowire and substrate,and thus reduce the nanowire *** the decrease in nanowire diameter,the capacity for the nanowire to better conform to the substrate reduces the length of the wedge-shaped gaps,leading to the observed increase in nanowire *** results have improved our understanding of the unique friction behaviour of *** an improved understanding is expected to benefit the design and operation of nanowire-friction-based devices,including bio-inspired fibrillar adhesives,soft grippers,rotary nanomotors,and triboelectric nanogenerators.

关键词： frictional shear stress nanowires graphite surface step waviness

Hematologic and biochemical reference intervals for specific pathogen free 6-week-old Hampshire-Yorkshire crossbred pigs

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Journal of Animal Science and Biotechnology 2014年第3期5卷 286-290页

作者： Caitlin A Cooper Luis E Moraes james d Murray Sean d Owens department of Animal Science University of California department of Population Health and Reproduction University of California department of Pathology Microbiology and ImmunologySchool of Veterinary MedicineUniversity of California One Shields AvenueDavisCA 95616USA

Background： Hematologic and biochemical reference intervals depend on many factors, including age. A review of the literature highlights the lack of reference intervals for 6-wk-old specific pathogen free （SPF） Hampshire-Yorkshire crossbred pigs. For translational research, 6-wk-old pigs represent an important animal model for both human juvenile colitis and diabetes mellitus type 2 given the similarities between the porcine and human gastrointestinal maturation process. The aim of this study was to determine reference intervals for hematological and biochemical parameters in healthy 6-wk-old crossbred pigs. Blood samples were collected from 66 clinically healthy Hampshire-Yorkshire pigs. The pigs were 6 wks old, represented both sexes, and were housed in a SPF facility. Automated hematological and biochemical analysis were performed using an AdVIA 120 Hematology System and a Cobas 6000 C501 Clinical Chemistry Analyzer. Results： Reference intervals were calculated using both parametric and nonparametric methods. The mean, median, minimum, and maximum values were calculated. Conclusion： As pigs are used more frequently as medical models of human disease, having reference intervals for commonly measured hematological and biochemical parameters in 6-wk-old pigs will be useful. The reference intervals calculated in this study will aid in the diagnosis and monitoring of both naturally occurring and experimentally induced disease. In comparison to published reference intervals for older non SPF pigs, notable differences in leukocyte populations, and in levels of sodium, potassium, glucose, protein, and alkaline phosphatase were observed.

关键词： Biochemical analytes Hematology Pigs Reference interval SPF

Optical wavelength meter with machine learning enhanced precision

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Photonics Research 2023年第3期11卷 420-430页

作者： GAZI MAHAMUd HASAN MEHEdI HASAN PENG LIU MOHAMMAd RAd ERIC BERNIER TREVOR james HALL Photonic Technology Laboratory Advanced Research ComplexUniversity of OttawaK1N 6N5 OntarioCanada Huawei Technologies Canada KanataK2K 3J1 OntarioCanada

A photonic implementation of a wavelength meter typically applies an interferometer to measure the frequencydependent phase shift provided by an optical delay *** work shows that the information to be retrieved is encoded by a vector restricted to a circular cone within a 3d Cartesian object *** measured data belong to the image of the object space under a linear orthogonal *** impairments result in broken orthogonal symmetry,but the mapping remains *** circular cone is retained as the object space,which suggests that the conventional conic section fitting for the wavelength meter application is a premature reduction of the object space from R^(3)to R^(2).The inverse map,constructed by a learning algorithm,compensates impairments such as source intensity fluctuation and errors in delay time,coupler transmission,and photoreceiver sensitivity while being robust to *** simple algorithm does not require initial estimates for all parameters except for a broad bracket of the delay;further,weak nonlinearity introduced by uncertain delay can be corrected by a robust golden search *** phase-retrieval process is invariant to source power and its *** demonstrate that,to the extent that the ten parameters of the interferometer model capture all significant impairments,a precision limited only by the level of random noise is *** to measured data collected from a fabricated Si_(3)N_(4)wavelength meter,greater than an order of magnitude improvement in precision compared with the conventional method is achieved.

关键词： delay circular invariant

Anti-plane (SH) waves diffraction by an underground semi-circular cavity:analytical solution

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Earthquake Engineering and Engineering Vibration 2010年第3期9卷 385-396页

作者： Luo Hao vincent W. Lee Liang Jianwen HNTB Corporation Santa Ana CA 92707-8797 USA Sonny Astani department of Civil and Environmental Engineering University of Southern California Los Angeles CA 90089-2531 USA department of Civil Engineering Tianjin University Tianjin 300072 China

diffraction of a two-dimensional （2d） semi-circular cavity in a half-space under incident SH-waves is studied using the classic wave function expansion method with a new de-coupling technique. This so-called ＂improved cosine half- range expansion＂ algorithm exhibits an excellent performance in reducing displacement residual errors at two rim points of concern. The governing equations are developed in a manner that minimizes the residues of the boundary conditions. detailed derivation and analysis procedures as well as truncation of infinite linear governing equations are presented. The semi-circular cavity model presented in this paper, due to its simple profile, is expected to be used in seismic wave propagation studies as a benchmark for examining the accuracies of various analytical or numerical methods for mixed-boundary wave propagation problems.

关键词： plane SH waves diffraction, semi-circular cavity half-space improved cosine half-range expansion

Work conjugate pair of stress and strain in molecular dynamics

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International Journal of Smart and Nano Materials 2016年第3期7卷 144-178页

作者： Leyu Wang james d.Lee Cing-dao Kan Center for Collision Safety and Analysis College of ScienceGeorge Mason UniversityFairfaxVAUSA department of Mechanical and Aerospace Engineering the George Washington UniversityWashingtonDC 20052USA

Certain stress and strain form a thermodynamic conjugate pair such that their strain energy equals to a scalar-valued potential *** atomistic stresses and strains are analytically derived based on the work conjugate *** is numerically verified with both two-body and three-body potentials that the atomistic Kirchhoff stress,first-order Piola–Kirchhoff stress and second-order Piola–Kirchhoff stress are conjugates to atomistic logarithmic strain,deformation gradient and Lagrangian strain,*** stress at 0 K based on original volume is the special form of atomistic Kirchhoff stress for pair *** is numerically verified that Hencky strain is not conjugate to any stress.

关键词： Thermodynamic conjugacy logarithmic strain atomistic stress deformation gradient strain energy interatomic potential Tersoff potential atomistic first-order Piola-Kirchhoff stress atomistic second-order Piola-Kirchhoff stress atomistic Kirchhoff stress virial stress

Global variation in skin injures and skincare practices in extremely preterm infants

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World Journal of Pediatrics 2023年第2期19卷 139-157页

作者： Pranav Jani Umesh Mishra Julia Buchmayer Rajesh Maheshwari daphne d’Çruz Karen Walker duygu Gözen Krista Lowe Audrey Wright james Marceau Mihaela Culcer Archana Priyadarshi Adrienne Kirby james EMoore Ju Lee Oei Vibhuti Shah Umesh Vaidya Abdelmoneim Khashana Sunit Godambe Fook Choe Cheah Wen-Hao Zhou Xiao-Jing Hu Muneerah Satardien Faculty of Medicine and Health The University of SydneySydneyNSWAustralia department of Neonatology Westmead HospitalWestmeadNSW2145Australia Comprehensive Center for Pediatrics Department of Pediatrics and Adolescent MedicineDivision of NeonatologyPediatric Intensive Care and NeuropediatricsMedical University of ViennaViennaAustria department of Newborn Care Royal Prince Alfred HospitalCamperdownNSWAustralia Council of International Neonatal Nurses BostonMAUSA The George Institute for Global Health SydneyNSWAustralia Sydney Institute for Women Children and Their FamiliesSydneyNSWAustralia Pediatric Nursing department Florence Nightingale Faculty of Nursingİstanbul University-CerrahpaşaIstanbulTurkey The National Health and Medical Research Council Clinical Trials Centre University of SydneySydneyNSWAustralia Connecticut Children’s division of Neonatal-Perinatal Medicine Connecticut Children’s Medical CenterHartfordCTUSA UCONN School of Medicine FarmingtonCTUSA The Royal Hospital for Women RandwickNSWAustralia School of Women’s and Children’s Health University of New South WalesRandwickNSWAustralia department of Paediatrics and Institute of Health Policy Management and EvaluationMount Sinai HospitalTorontoCanada department of Pediatrics King Edward Memorial HospitalPuneIndia Pediatrics Suez Canal UniversityIsmailiaEgypt divisional director for Clinical Governance Women’sChildren’s and Clinical SupportImperial College Healthcare NHS TrustLondonUK department of Pediatrics Faculty of MedicineUniversiti KebangsaanBangiMalaysia Hospital Canselor Tuanku Muhriz Jalan Yaacob LatifBandar Tun RazakKuala LumpurMalaysia department of Neonatology and Vice President Children’s Hospital of Fudan UniversityShanghaiChina Vice director of Nursing department Children’s Hospital of Fudan UniversityShanghaiChina department of Paediatrics and Child Health Tygerberg HospitalCape TownSouth Africa University of Stellenbosch Cape TownSouth Africa

Background Globally,are skincare practices and skin injuries in extremely preterm infants comparable?This study describes skin injuries,variation in skincare practices and investigates any association between *** A web-based survey was conducted between February 2019 and August *** skin injuries and describing skincare practices in extremely preterm infants were the main *** association between skin injuries and skincare practices was established using binary multivariable logistic regression adjusted for *** Responses from 848 neonatal intensive care units,representing all geographic regions and income status groups were *** dermatitis(331/840,39%)and medical adhesive-related skin injuries(319/838,38%)were the most common *** a local skincare guideline reduced skin injuries[medical adhesive-related injuries:adjusted odds ratios(aOR)=0.63,95%confidence interval(CI)=0.45–0.88;perineal injuries:aOR=0.66,95%CI=0.45–0.96;local skin infections:OR=0.41,95%CI=0.26–0.65;chemical burns:OR=0.46,95%CI=0.26–0.83;thermal burns:OR=0.51,95%CI=0.27–0.96].Performing skin assessments at least every four hours reduced skin injuries(abrasion:aOR=0.48,95%CI=0.33–0.67;pressure:aOR=0.51,95%CI=0.34–0.78;diaper dermatitis:aOR=0.71,95%CI=0.51–0.99;perineal:aOR=0.52,95%CI=0.36–0.75).Regional and resource settings-based variations in skin injuries and skincare practices were *** Skin injuries were common in extremely preterm *** in practice and improved surveillance appears to reduce the occurrence of these *** evidence regarding optimal practices is needed to reduce skin injuries and minimize practice variations.

关键词： Extremely premature infants Injuries Neonatal intensive care unit Skin care Wounds

The development of a high-performance Ni-superalloy additively manufactured heat pipe

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Advances in Manufacturing 2022年第4期10卷 610-624页

作者： Sheng Li Khamis Essa james Carr States Chiwanga Andrew Norton Moataz M.Attallah School of Electromechanical Engineering Guangdong University of TechnologyGuangzhou 510006People’s Republic of China School of Engineering University of BirminghamEdgbastonBirmingham B152TTUK Henry Moseley X-ray Imaging Facility Henry Royce Institute for Advanced MaterialsDepartment of MaterialsUniversity of ManchesterManchester M139PLUK European Thermodynamics Ltd 8 Priory Business ParkWistow RoadKibworthLeicestershire LE80RXUK Rolls-Royce plc P.O.Box 31Derby DE248BJUK School of Metallurgy and Materials University of BirminghamEdgbastonBirmingham B152TTUK

Additively manufacturing(AM)has been used to manufacture fine structures with structured/engineered porosity in heat management *** this study,laser powder bed fusion(LPBF)was used to manufacture a high-performance Ni-superalloy heat pipe,through tailoring LPBF process parameters to fabricate thin wall and *** using novel laser scanning strategies,wick structure heat pipes with maximised surface-area-to-volume ratio,fine features size around 100µm,and controlled porosity were successfully *** and X-ray microtomography(micro-CT)were used to investigate the 3d structure of the void space within the *** test results showed that most of the heat pipes made by LPBF had better performance than the conventionally manufactured *** study also investigated the influences of the process parameters on the porosity volume fraction and the feature *** results showed that LPBF process could fabricate thin structure due to the change of melt pool contact *** relationship between process parameters and bead size reported in this study could help design and manufacture heat pipe with complex fine structure.

关键词： Laser powder bed fusion(LPBF) Heat pipe Melt pool Microtomography(micro-CT)

Impact of source tissue and ex vivo expansion on the characterization of goat mesenchymal stem cells

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Journal of Animal Science and Biotechnology 2015年第2期6卷 230-251页

作者： Nuradilla Mohamad-Fauzi Pablo J Ross Elizabeth A Maga james d Murray department of Animal Science University of California Institute of Ocean and Earth Sciences University of Malaya department of Population Health and Reproduction University of California

Background： There is considerable interest in using goats as models for genetically engineering dairy animals and also for using stem cells as therapeutics for bone and cartilage repair. Mesenchymal stem cells （MSCs） have been isolated and characterized from various species, but are poorly characterized in goats. Results： Goat MSCs isolated from bone marrow （BM-MSCs） and adipose tissue （ASCs） have the ability to undergo osteogenic, adipogenic and chondrogenic differentiation. Cytochemical staining and gene expression analysis show that ASCs have a greater capacity for adipogenic differentiation compared to BM-MSCs and fibroblasts. different methods of inducing adipogenesis also affect the extent and profile of adipogenic differentiation in MSCs. Goat fibroblasts were not capable of osteogenesis, hence distinguishing them from the MSCs. Goat MSCs and fibroblasts express Cd90, Cd105, Cd73 but not Cd45, and exhibit cytoplasmic localization of OCT4 protein. Goat MSCs can be stably transfected by Nucleofection, but, as evidenced by colony-forming efficiency （CFE）, yield significantly different levels of progenitor cells that are robust enough to proliferate into colonies of integrants following G418 selection. BM-MSCs expanded over increasing passages in vitro maintained karyotypic stability up to 20 passages in culture, exhibited an increase in adipogenic differentiation and CFE, but showed altered morphology and amenability to genetic modification by selection. Conclusions： Our findings provide characterization information on goat MSCs, and show that there can be significant differences between MSCs isolated from different tissues and from within the same tissue. Fibroblasts do not exhibit trilineage differentiation potential at the same capacity as MSCs, making it a more reliable method for distinguishing MSCs from fibroblasts, compared to cell surface marker expression.

关键词： Adipose Bone marrow Characterization differentiation Goat Mesenchymal stem cells

Are trends in SeaWiFS chlorophyll time-series unusual relative to historic variability

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Acta Oceanologica Sinica 2010年第2期29卷 1-4页

作者： james A Yoder Maureen A Kennelly Scott C doney Ivan d Lima Woods Hole Oceanographic Institution Woods Hole MA 02540 USA Graduate School of Oceanography University of Rhode Island Narragansett RI 02882 USA

For selected locations in the Atlantic and Pacific Ocean, we compared surface ocean chlorophyll time series extracted from SeaWiFS imagery from 1997-2004 with the results of an ocean coupled circulation and biogeochemical model covering the period 1958-2004. during the 1997-2004 time period, linear trends in model and satellite time series were significantly correlated at most of the 44 sites we studied. Eleven sites were selected for further study, and we used the longer time series of the model to assess whether trends observed during the SeaWiFS period at these 11 sites were unusual in relation to those observed over the longer historical period covered by the model. The results show that the trends observed during the SeaWiFS period were not unusual and fell well within the range in magnitude of linear trends observed in other 8-year periods of model output. This result implies that the SeaWiFS satellite ocean color time series is not yet sufficiently long, on its own, to directly observe any long term changes in phytoplankton chlorophyll that may be occurring in the surface waters of the open ocean as a result of increased ocean stratification linked to global climate changed.

关键词： SeaWiFS trends climate change chlorophyll biogeochemical model ENSO