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71.
This study aimed to investigate the kicking limb coordinative patterns adopted by karate practitioners (karateka) when impacting (IRK), or not impacting (NIRK) a target during a roundhouse kick. Six karateka performed three repetitions of both kicks while kicking limb kinematics were recorded using a stereophotogrammetric system. Intra-limb coordination was quantified for hip and knee flexion–extension from toe-off to kick completion, using the Continuous relative phase (CRP). Across the same time interval, thigh and shank angular momentum about the vertical axis of the body was calculated. For all trials, across all participants, CRP curve peaks and maximum and minimum angular momentum were determined. A RM-ANOVA was performed to test for differences between kicking conditions.The CRP analysis highlighted, during the central portion of both kicks, a delayed flexion of the hip with respect to the knee. Conversely, during the terminal portion of the CRP curves, the NIRK is performed with a more in-phase action, caused by a higher hip angular displacement. The NIRK is characterized by a lower angular momentum which may enhance control of the striking limb. It would seem that the issue of no impact appears to be solved through the control of all segments of the kicking limb, in contrast to the primary control of the lower leg only observed during the IRK. 相似文献
72.
Anwynne Kern 《Journal of Psychology in Africa》2013,23(4):641-644
The study investigated the perceptions of educators about Attention Deficit Hyperactivity Disorder, specifically their views on its incidence, causes and appropriate interventions in school settings. Five purposively selected educators from a private school participated in the study. Ethnographic interview was used to collect and analyze the data. The results revealed that the educators considered ADHD mainly a physiological disorder with primarily genetic and environmental causes. Regardless the educators preferred medication as the intervention method despite being aware of additional intervention methods. 相似文献
73.
《Psychoanalytic Social Work》2013,20(2):31-51
Abstract Three steps are presented to revitalize the concept of the Oedipus complex and to apply this revitalized concept to clinical work. First, a comprehensive child developmental map is constructed of the road from the early infantile genital phase to the achievement of the full Oedipus stage, integrating the diverse components of self, gender, libido, aggression, ego, superego, object relationship and adaptation. Second, specific developmental lines (e.g., separation-individuation) are magnified in a given patient for close examination to explore the relationship to that patient's overall oedipal conflicts. Third, a reciprocal interaction is fostered between the evolving conceptual framework and the emerging clinical data. The paper contains two in-depth case examples to illustrate the clinical application of these ideas. 相似文献
74.
Takato Nakamura Nobuo Saito Yoshiko Suzuki Yoichiro Nakanishi Goro Shimaoka 《Philosophical Magazine Letters》2013,93(4):161-163
Abstract New electron spin resonance (ESR) lines with g1 = 2·0017 and g2 and g3 = 2·0006 have been found in the ESR spectra of as-deposited a-Si1–x Cx:H films prepared by magnetron sputtering of silicon in the gas mixtures of methane and argon. Similarities between the observed spectra and those for the E′ centre in glassy SiO2 are discussed. 相似文献
75.
An analysis of cross-sections perpendicular to the main diagonal of a cubic elementary cell of a Samson structure–β-Mg2Al3 has been conducted. It has been proved that all skeleton atoms, i.e. which occupy their positions with probability of 100%, form a framework of hexagonal planes. These planes are a part of three domains shifted with respect to each other by one-third of the length of cube's diagonal. Space between domains is filled up by clusters with partially occupied atomic positions. For hexagonal domains, the elementary cell and positions of decorating atoms have been determined. 相似文献
76.
Yongqiang Wang Zhiwei Zhang Hu Mao Guohui Zhu Na Li 《Philosophical Magazine Letters》2013,93(7):283-291
ABSTRACTThe tensile properties of TiNi43.5Fe6.5 alloy samples having different grain sizes (0.16, 0.35, 1.7, 2.3, and 3.9?μm) and fabricated by severe plastic deformation and annealing were investigated. It was observed that both the strength and the elongation of the alloy increase with a decrease in the grain size until the average size reaches 1.7?μm. However, for average grain sizes smaller than 1.7?μm, the elongation decreases continuously with further grain refinement. On the other hand, the strain-hardening rate does not decrease with the decrease in plasticity but instead increases slightly. The poor ductility of the ultrafine-grained TiNi43.5Fe6.5 alloy is accompanied by a high degree of strain hardening. This newly observed ductility behaviour of the ultrafine-grained TiNi43.5Fe6.5 alloy is elucidated by characterising the intragranular and grain boundaries. 相似文献
77.
78.
Shen-Hung Wei 《Philosophical Magazine Letters》2013,93(10):609-619
Stainless steel (316L) and 8 mol pct Y2O3-stabilized zirconia (8Y-ZrO2) were bonded using a Ti–Ni–Ti multilayer at 1173 K (900 °C) for 1 h. Cross-sectional transmission electron microscopy specimens were prepared by an innovative focused ion beam plus lift-out technique. In addition to acicular α-Ti, the dissolution of Fe, Cr, and Ni diffusing outwards from 316L into β-Ti led to the precipitation of the omega (ω) phase with different variants in the residual Ti foil between 316L and Ni. The ω-phase was not found in the residual Ti foil between Ni and 8Y-ZrO2, while Ti2Ni precipitates were precipitated in some α-Ti grains owing to the exclusion of Ni from the β-Ti. 相似文献
79.
Highly inhomogeneous compressive plasticity in nanocrystal-toughened Zr–Cu–Ni–Al bulk metallic glass
A Zr62Cu15.5Al10Ni12.5 bulk metallic glass with a large supercooled liquid region of 90 K, produced by copper-mould casting, exhibits a high strength of 1730 MPa and superior but highly inhomogeneous plasticity under uniaxial compression at ambient temperature. Micro-X-ray diffraction shows that compressive loading facilitates crystallization in the monolithic glassy alloy, resulting in room-temperature plasticity. The plastic deformation of the Zr62Cu15.5Al10Ni12.5 BMG may be attributed to in situ precipitation of nanocrystals during compression in heavily deformed areas. 相似文献
80.
Prabir K. Mukherjee 《Philosophical Magazine Letters》2013,93(4):160-165
This article develops renormalization-group techniques to analyze the phase transition between the crystal and the rotator-V (Rv), phase in n-alkanes. An explicit free energy is constructed and it is verified that the unstable fixed point corresponds to a fluctuation-driven first-order crystal to Rv phase transition. Available experimental data are consistent with our model. 相似文献