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271.
分析了节点各杆最不利受力状况试验结果,测试了各杆在最不利荷栽作用下的应力状况,揭示了节点的受力性能,为3K形钢管节点的应用提供准确的试验数据。 相似文献
272.
Children who are abused at home are at an increased risk of bullying perpetration and bullying victimization. Within that context, the purpose of the present study was to test Agnew’s general strain theory and the peer deviancy training hypothesis by utilizing structural equation modeling to empirically examine pathways linking punitive parenting to bullying perpetration and bullying victimization. This study adds to the literature in two important ways. First, potential mediating linkages between punitive parenting and bullying perpetration and bullying victimization were examined, including socially withdrawn behavior and deviant peer affiliation. Second, these relationships were considered in a longitudinal sample of South Korean adolescents, which is a novel examination given that parenting in South Korea is guided largely by Confucianism which reinforces parental control, restrictiveness, and a punitive nature. Results indicate that: (1) punitive parenting is directly related to bullying perpetration but not bullying victimization; (2) punitive parenting was found to have indirect effects only on bullying perpetration; (3) deviant peer affiliation increased the likelihood of bullying perpetration and victimization; and (4) socially withdrawn behavior only affected bullying perpetration via its effect on deviant peer affiliation. 相似文献
273.
本文应用X射线衍射方法、红外光谱分析方法、扩展电阻测量方法研究了N+和N+2注入硅的应变、损伤度、扩展电阻率随注入剂量、注入深度变化的规律,形成Si3N4非晶层的条件.建立了多层的物理模型和胁变函数的数学模型,利用计算机和曲线拟合等手段,得出了合理的结论. 相似文献
274.
本文介绍一种制新型冷设备除霜检测设计的原理及制作,此项设计具有价格低、环保、节电的优点,有良好的应用前景。 相似文献
275.
In this paper, the strain energy function proposed by Shang and Cheng was generalized by introducing a nonlinear term.Void formation and growth in the interior of a sphere composed of compressible hyper-elastic material, subjected to a prescribed uniform displacement, was examined.A parametric cavitated bifurcation solution for the radial deformed function was obtained.Stability of the solution of the cavitated bifurcation equation was discussed.With the appearance of a cavity, an interesting feature of the radial deformation near the deformed cavity wall is the transition from extension to compression. 相似文献
276.
对山西省万家寨引黄入晋工程总干线7号隧洞开挖和蓄水运行的几种工况进行了非线性有限元分析.主要内容包括采用分级堆填过程模拟风积黄土层的初始应力场;应用:Duncan释放荷载思想和弹性理论面力公式进行开挖卸荷计算;采用Goodman节理单元模拟衬砌管片的接缝;应用Terzaghi松动土压力理论施加管片上压力;确定土的Duncan-Chang模型参数时,分别取原状土进行了卸载和加载试验,并比较了用2种试验获得的模型参数进行有限元变形分析的结果,多种工况的有限元分析得到了一些合理的结果. 相似文献
277.
Mathias Samson Tony Monnet Anthony Bernard Patrick Lacouture Laurent David 《Journal of sports sciences》2015,33(15):1535-1543
The aim of this study was to determine the role played by the entry-and-stretch phase in the coordination of swimming, at the different paces of race. Three national level swimmers (two men and one woman) were recorded, in lateral and bottom views, in three swimming paces: sprint (50 m and 100 m), middle-distance (200 m and 400 m) and long-distance (800 m and 1500 m). Anatomical landmark positions were obtained by manual digitalisation of the videos. Computational fluid dynamics and experimental studies (with a strain gauge balance and particle image velocimetry method) were used to measure and to calculate the external forces applied to the hand and to the forearm and to visualise the flow around the profile. Entry-and-stretch is the phase which varies the most according to the swimming pace. This phase can be decomposed into two sub-phases: one, the extension forward coordinated with the insweep of the opposite arm, and another one, the rotation downward coordinated with the upsweep. Results show that, at the three paces, this phase is not propulsive and could contribute essentially to maintain the horizontal balance of the body. 相似文献
278.
Evgeny B.Bablyuk 《出版与印刷》2015,(1):42-46
<正>It is recently obvious a wide use of printing on polymer films.This is bound up most of all with a rapid development of the industry for production of goods in colorful packaging made of polymer materials.The interest in printing on polymer films increases significantly in view of the application of new technological processes of electronic microchips manufacturing by printing methods[1-4].At 相似文献
279.
Evgeny B. Bablyuk 《出版与印刷》2015,(1)
It is recently obvious a wide use of printing on polymer films. This is bound up most of all with a rapid development of the industry for production of goods in colorful packaging made of polymer mate-rials. 相似文献
280.
Tendon stress may be one of the important risk factors for running-related tendon injury. Several methods have been used to estimate Achilles tendon (AT) loading during a human performance such as inverse dynamics (ID) and inverse dynamics-based static optimisation (IDSO). Our purpose was to examine differences between ID and IDSO estimates of AT loading during running. Kinematic data were captured simultaneously with kinetic data. Imaging of the AT cross-sectional area was performed with ultrasound for 17 healthy runners (height: 170.2 ± 6.2 cm, mass: 63.9 ± 11.0 kg, age: 21.8 ± 1.4 years). AT stress, strain, and force were estimated from both ID and IDSO approaches. The two methods resulted in minimal differences (3.6–4.7%) in estimated peak AT stress, strain, and force (P = 0.051–0.054); however, IDSO estimates were greater (32.7–36.8%) during early-stance phase of running (P = 0.000–0.008). This difference in AT load during early-stance may be due to the inability of the ID to account muscle coactivation. The similarity between the peak AT loading for ID and IDSO methods revealed that the advantage of IDSO used to estimate muscle forces had little effect on the ankle plantar flexor peak forces during running. Therefore, the use of IDSO with a higher computational cost compared with ID may not be necessary for estimating AT stress during running. 相似文献