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Chinese Physics B 2020年第4期29卷 391-396页

作者：王一郭祥魏节敏杨晨罗子江王继红丁召 College of Big Data and Information Engineering Guizhou UniversityGuiyang 550025China Power Semiconductor Device Reliability Research Center of the Ministry of Education Guizhou UniversityGuiyang 550025China Key Laboratory of Micro-Nano-Electronics of Guizhou Province Guiyang 550025China School of Information Guizhou University of Finance and EconomicsGuiyang 550025China

GaAs multiple concentric nano-ring structures(CNRs)are prepared with multistep crystallization procedures by droplets epitaxy on GaAs(001)to explore the influence of different initial crystallization temperatures on CNRs morphology.Atomic force microscope(AFM)images show that GaAs nanostructures are more likely to form elliptical rings due to diffusion anisotropy.Meanwhile,with the increase of initial crystallization temperature,the inner ring height and density of CNRs are increased,and outer rings are harder to form.In addition,the mechanism of formation of CNRs is discussed by classical nucleation theory and diffusion theory.The method can be used to calculate the diffusion activation energy of gallium atoms(0.7±0.1 eV)on the GaAs(001)surface conveniently.

关键词： concentric nano-ring structures crystallization temperature activation energy of diffusion

Analysis of Vibration and Noise of Induction Motor Equipped with concentric Single-Double-Layer Star-Delta Winding

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Chinese Journal of Electrical Engineering 2019年第1期5卷 36-46页

作者： Zechen Li Chong Di Xiaohua Bao Hefei University of Technology School of Electrical Engineering and AutomationHefei 230009China Department of Electrical Engineering LUT School of Energy SystemsLappeenranta University of TechnologyLappeenranta 53851Finland

Compared with changing the structure of a motor that has been manufactured,changing the type of stator winding is an economical and time-saving method to reduce the vibration and noise.Thus,a concentric single-double-layer star-delta(CSDLSD)winding for an induction motor is described in this paper with the aim of reducing the noise of the motor.By planning the turns relationship between the two parts of the winding,the harmonic component of the air-gap magnetic field can be decreased.Besides this,through adjusting the turns ratio in each slot of concentric winding per phase respectively,the waveform of the air-gap magnetic field becomes closer to a sinusoidal type.Three motors equipped with the CSDLSD winding and another two types of stator winding were analyzed.The theoretical analysis and the two-dimensional finite element method(2D-FEM)were combined to study the relationship between the harmonics of the air-gap magnetic field and the stator winding.Finally,a 2D fast Fourier transformation(2D-FFT)method was used to obtain the time-frequency spectrum of the air-gap flux density and electromagnetic excitation force,and compared with a natural vibration wave.The noise distribution was obtained using the harmonic response.The results of the theoretical analysis,2D-FEM,2D-FFT,and harmonic response corroborate each other such that the motor applying CSDLSD winding could reduce both the vibration and noise.

关键词： Induction motor concentric single-double-layer star-delta winding 2D-FFT vibration

An analytic solution and investigation of character of viscoelastic fluids in double-gap concentric cylinder rheometer

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Science China Mathematics 1995年第12期38卷 1510-1519页

作者：黄军旗刘慈群 Department of Resources and Environmental Sciences Beijing Normal University Beijing 100875 China Institute of Porous Flow and Fluid Mechanics Chinese Academy of Sciences Langfang 102801 China

An analytical solution to annular pipe flow of the second fluid and Maxwell fluid is given using Weber integral transform. The formulas can be used to analyse the behavior of unsteady flow of viscoelastic fluid in annular pipe, especially to analyse the flow character of double-gap concentric cylinder rheometer. It is found by computation that when the outer cylinder is in simple periodic motion, there are step junctions along the history curve of Maxwell fluid’s velocity and shear stress, and at step junctions both amplitude and phase of oscillatory wave vary sharply; when the outer cylinder makes uniform rotation, the velocity and shear stress of Maxwell fluid exhibit rhombic wave oscillation, and its period is in close parabolic relation with material constant H.

关键词： viscoelastic fluid concentric cylinder rheometer analytical solution character analysis.

SATELLITE-BASED ANALYSIS ON THE concentric EYEWALL REPLACEMENT CYCLES OF SUPER TYPHOON MUIFA (1109)

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Journal of Tropical Meteorology 2016年第3期22卷 330-340页

作者：朱雪松余晖毛卓成徐明谈建国 Shanghai Institute of Meteorological Science Shanghai 200030 China Shanghai Typhoon Institute/CMA Shanghai 200030 China Shanghai Urban Environment Meteorology Center Shanghai 200135 China Institute of Heavy Rain/CMA Wuhan 430074 China

Multisatellite data is used to analyze the characteristics of three eyewall replacement cycles(ERCs) during the lifetime of Typhoon Muifa(1109).Spiral rainbands evolutions,concentric eyewall(CE) structure modes,CE durations,and intensity changes are discussed in detail.In addition,an ERC evolution model of Typhoon Muifa is given.There are four main findings.(1) The outer spiral rainband joins end to end to form the outer eyewall after it disconnects from the original(inner) eyewall.The inner eyewall weakens as the outer eyewall becomes axisymmetric and is intensified.The contraction of the outer eyewall causes the inner eyewall to dissipate rapidly.Finally,the ERC ends with an annular eyewall or spiral rainbands.(2) Although the CE duration times of Typhoon Muifa's three ERCs covered a large range,the CE structures were all maintained for approximately 5 h from the formation of the axisymmetric outer eyewall to the end of the cycle.(3) There is no obvious precipitation reflectivity in the eye or moat region for the subsidence flow.The convection within the two eyewalls is organized as a radially outward slope with increasing height.(4) Typhoon intensity estimation results based on ADT may not explain the intensity variations associated with ERC correctly,while the typhoon's warm core data retrieved from AMSU-A works well.

关键词： satellite data super typhoon concentric eyewall eyewall replacement cycle intensity variations

Training Effect of Isotonic concentric and Eccentric Contraction of Elbow Flexors in Different Combinations

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北京体育大学学报 1995年第S2期18卷 56-60页

作者： LAI Liuming YANG Jingyi (31 years old, lecturer)

In order to determine a rational protocol for isotonic training from macroscopic angle, five training protocols were designed, particularly protocols composed of pure eccentric contraction with heavy resistance in different propotions. The study results indicated that the protocol mixed with faster speed eccentric training,being more rational than traditional isotonic training and pure isotonic eccentric training, had the most all - round effects(including change of musle size, isotonic strength, musle power and et al. ). The protocol principle mixed with faster speed eccentric training may be widely used in rehabilitation and sports training,especially in the sports events of strength resistance. The significance to study the ratio of eccentric contaction to concentic contraction was suggested.

关键词： rehabilitation of musle function strength training eccentic concentric isokinetic musle power

Walking and Aerobic Capacity in Old Adults after concentric and Eccentric Endurance Exercise at Self-Selected Intensities

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Health 2014年第8期6卷 654-663页

作者： Mandy L. Gault Mark E. T. Willems Department of Sport & Exercise Sciences University of Chichester Chichester UK

Self-selected exercise intensity can be a useful exercise prescription tool for older adults;however, it is not known if it can elicit improvements in walking and aerobic capacity. In older adults, effects of concentric or eccentric endurance exercise at self-selected walking speed were examined on 1-mile indoor walk performance, predicted maximum oxygen uptake and physiological parameters. Twenty-four older adults (67 ± 4 years) completed 3 × 30 min treadmill walks per week for 12-weeks on level (LTW, n = 11, 0%) or downhill (DTW, n = 13, ﹣10%) treadmill gradient at a self- selected speed, which progressed every 4 weeks. Maximal oxygen uptake was predicted using a 1-mile walk at 4-week intervals with physiological responses recorded using a portable metabolic system. One-mile walking speed increased from baseline following 8- and 12-weeks (12 weeks: LTW: 13% ± 6%, DTW: 14% ± 9%,

关键词： Ageing concentric Endurance Exercise Eccentric Endurance Exercise Self-Selected Intensity Aerobic Capacity

Concept Development and Implementation of Family Care/Caring Theory in concentric Sphere Family Environment Theory

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Open Journal of Nursing 2015年第9期5卷 749-757页

作者： Naohiro Hohashi Junko Honda Division of Family Health Care Nursing Department of Nursing Graduate School of Health Sciences Kobe University Kobe Japan

Caring is directed toward a variety of things. One of them is thought to be the concept of “family caring” aimed at families. This study attempts to clarify family caring and develop Family Care/ Caring Theory (FCCT), with the aim of implementing it in conjunction with an existing family nursing theory, the concentric Sphere Family Environment Theory (CSFET). In Japan and in Hong Kong, family ethnography (including formal interviews) was conducted. As a result, the item “family health care nurses and their colleagues” was added to the family external environment of the CSFET. In the family environment, evidence was obtained to the effect that the family system unit is cared for by the nursing professional, and conversely the family system unit cares for the nursing professional, in a circular transaction. Observing the two-dimensional plane formed by the structural distance and functional distance, family caring assumes a structure of concentric circles, and according to transactions, the structural distance and functional distance between the nursing professional and family system unit are gradually approached, and through deepening of mutual trust maintain an appropriate distance. Moreover observing the three-dimensional space-time continuum which is created through addition of the temporal distance, family caring forms a helical structure. As transactions are repeated along the temporal axis, the family system unit’s self-actualization of other individuals and the self-actualization of the nursing professional are realized. Through these processes, a family care/caring relationship is reinforced and established. This is the concept of FCCT. Through future utilization in clinical settings this will be empirically substantiated, and it will be necessary to continue making creative corrections and revisions.

关键词： Family Caring Family Care/Caring Theory (FCCT) concentric Sphere Family Environment Theory (CSFET) Family Health Care Nurses and Their Colleagues

Improvement of Camera Calibration Accuracy Based on Periodic Arrangement Characteristics of Calibration Target Pattern

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天津大学学报：英文版 2017年第6期23卷 582-590页

作者： Qingguo Tian Yunpeng Li Jinjiang Wang Tianyu Chang School of Precision Instruments and Opto-Electronics Engineering Tianjin UniversityTianjin 300072China Key Laboratory of Opto-Electronics Information Technology of Ministry of Education Tianjin 300072China

Conventional camera calibration that employs calibration targets is a commonly used method to acquire a camera's intrinsic and/or extrinsic parameters. The calibration targets are usually designed as periodic arrays of simple high-contrast patterns that provide highly accurate world coordinate system points and the corresponding image pixel coordinate system points. The existing pixel coordinate extraction algorithms can reach a sub-pixel level; however, they treat each single pattern in one image as an independent individual, which makes it difficult to further improve extraction accuracy. In this paper, a novel method is proposed by utilizing the periodic arrangement characteristics of the calibration target pattern as a global constraint to improve the calibration accuracy. Based on a camera's pinhole model, the intersection point of two fitted curves is used as an optimized pixel point to replace the initial one. Following the pixel coordinate optimization procedures, experiments were performed using real data from a 3D laser line scanner and a dynamic precision calibration target. Our results show that the relative errors of camera homography matrix elements obtained by the proposed optimization method were reduced compared with the commonly used method. The average coordinate measurement accuracy can be improved by nearly 0.05 mm. It is shown that the proposed optimization method can enhance the camera calibration accuracy,especially when the extracted pixels are of poorer precision.

关键词： Camera calibration Pixel coordinate optimization Periodic arrangement characteristic Intersection point concentric circle control point

Acute effects of static stretching on peak and end-range hamstring-to-quadriceps functional ratios

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World Journal of Orthopedics 2015年第9期6卷 719-726页

作者： Ufuk Sekir Ramiz Arabaci Bedrettin Akova Department of Sports Medicine Medical Faculty of Uludag University Department of Physical Education and Sport Education Faculty of Sport SciencesUludag University

AIM: To evaluate if static stretching influences peak and end-range functional hamstring-to-quadriceps(H/Q) strength ratios in elite women athletes. METHODS: Eleven healthy female athletes in an elite competitive level participated to the study. All the participants fulfilled the static stretching or non-stretching(control) intervention protocol in a randomized design on different days. Two static unassisted stretching exercises, one in standing and one in sitting position, were used to stretch both the hamstring and quadriceps muscles during these protocols. The total time for the static stretching was 6 ± 1 min. The isokinetic peak torque measurements for the hamstring and quadriceps muscles in eccentric and concentric modes and the calculations for the functional H/Q strength ratios at angular velocities of 60°/s and 180°/s were made before(pre) and after(post) the control or stretching intervention. The strength measurements and functional strength ratio calculations were based during the entire- and end-range of knee extension.RESULTS: The pre-test scores for quadriceps and hamstring peak torque and end range values were not significantly different between the groups(P > 0.05). Subsequently, although the control group did notexhibit significant changes in quadriceps and hamstring muscle strength(P > 0.05), static stretching decreased eccentric and concentric quadriceps muscle strength at both the 60°/s and 180°/s test speeds(P concentric hamstring muscle strength at both the 60°/s and 180°/s test speeds(P 0.05). Furthermore, the functional H/Q strength ratios exhibited no significant alterations during the entire and end ranges of knee extension both in the static stretching or the control intervention(P > 0.05

关键词： Elite women athletes Eccentric concentric Static stretching Functional hamstring-to-quadriceps ratio Muscle strength

Factors Affecting the Perception of Family Functioning among Couples in Child-Rearing Japanese Families

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Open Journal of Nursing 2015年第5期5卷 407-415页

作者： Junko Honda Yuuri Nakai Shota Kakazu Naohiro Hohashi Division of Family Health Care Nursing Department of Nursing Graduate School of Health Sciences Kobe University Hyogo Japan Department of Nursing Faculty of Health Sciences School of Medicine Kobe University Hyogo Japan

In family healthcare nursing, the family system unit (i.e., a group in which the members, seen as a whole, mutually interact) is the target of care. As nurses tend to obtain family-related information from particular family members in the clinical setting, when assessing families, they often confront the issue of the differences between the theoretical level and methodological level. Although this issue needs resolving for evidence-based family nursing practice, sufficient research is lacking on the methodology related to family assessment. The present study aimed to clarify the factors that affected evaluation of family functioning among couples. Semi-structured interviews were conducted with 10 child-rearing families (couples) using the Survey of Family Environment (SFE) as a family functioning scale. Content analysis identified 12 factors that affected discrepancies in the couples’ evaluations and eight factors that affected agreement in those evaluations. These factors were classified into three categories: factors concerning family or family members;factors concerning questions related to the SFE;and factors concerning the view of the family as a whole. The results of this study should contribute to the development of family assessment tools and effective methods for evaluation of family care.

关键词： Family Functioning Discrepancy Survey of Family Environment (SFE) Japan concentric Sphere Family Environment Theory (CSFET)