中板在铁路运输中窜出事故分析

本文通过对《铁路货物装载加固定型方案》所装中板在运输途中窜出事故现场进行测量和分析,从车辆运行的振动形态、中板上的作用力以及中板的紧急制动状态诸方面对窜出事故因素进行了探讨。并提出了防止事故发生的装载改进措施。     

Pure bending of simply supported circular plate of transversely isotropic functionally graded material

INTRODUCTION In recent years, functionally graded materials (FGMs) have attracted more and more attention. Due to their continuously varying material properties in space on the macroscopic scale, FGMs, therefore, are usually superior to conventional fiber-matrix materi-als in mechanical behavior, especially for perform-ance under thermal loading. Now FGMs have been widely used in various fields including electronics, chemistry, optics, biomedicine, etc. Heretofore, volumes of literatu…     

动力髋螺钉和髁钢板治疗股骨粗隆间骨折

目的:观察两种股骨粗隆间骨折内固定术后疗效.方法:用国产Richard钉和髁钢板治疗不同股骨粗隆间骨折13例和15例.结果:平均愈合时间:动力髋螺钉组8周,髁钢板组9.9周.结论:内固定治疗股骨粗隆间骨折手术后早期功能锻炼安全可行,可使关节功能早期恢复,并可有效预防并发症.动力髋螺钉较髁钢板内固定更利于病人早期活动.     

钢板弹簧弯曲回弹热校形规律的定量分析

论文论述了钢板弹簧在弯曲过程中的热校形消除回弹原理,即钢板弹簧在高温下的软化与短时应力松弛综合作用机制。对弯曲回弹热校形规律进行了定量理论分析和实验验证。导出的公式可用来定量估算其它弯曲工序热校形工艺参数。采用的理论分析方法,可应用于其它种类钣金件热校形规律的研究中。     

多孔超弹性矩形板中微孔的增长

The analyses of finite deformation and stress for a hyperelastic rectangular plate with some voids under an uniaxial extension were conducted. The governing differential equations were given from the incompressibility condition of the material. The solution was approximately obtained from the minimum potential energy principle. The growth of voids was discussed. One can see that an initial central circular-cylinder void becomes an elliptic-cylinder void, but an initial non-centeral circular-cylinder void becomes an elliptic-like cylinder void and the center of void has a shift. The stress distributions along the edges of voids were given and the phenomenon of stress concentration was observed. The influences of the distribution manner and size of voids, as well as the distance between them on the growth of voids were analyzed.     

微光夜视技术的新进展

微光夜视技术经过了几十年的发展，现在已经进入了实用阶段。研发微光夜视仪在军事和民用二方面都能发挥较大作用。文中回顾了微光夜视技术发展的历史和现状，并对发展趋势进行了展望。比较了各种技术的优势和劣势，分析了各国在军事方面的应用情况，提出了研究的必要性和可实现性。     

Finite Element Analysis of Reinforced Concrete Plate Impacted by Block

A new concept of structurally dissipating rock-shed （SDR） was developed by the lab of Tonello IC and LOCIE-ESIGEC （ France）. To decide the dimension of the plate used in SDR, an ANSYS model which could simulate the impact of rock in the centre of the plate was established by Fabien Delhomme. By using this model, some finite element analyses are carried out in the present paper. Firstly, a plate impacted by a block is numerically simulated, the numerical results obtained from different mesh sizes are compared and the accuracy of the finite element model is verified. Then, the dynamic response of the plate impacted at the boundary and in the medium part is computed. By analyzing the stress in rebar, the most dangerous region of impact of plate was found. For a rectangular plate, the most dangerous region is at the corner of the plate when a block drops in. Finally, the whole deformation process of the plate under dropping block was simulated and a simplified definition （ effect zone） to describe the deformation process in different positions of plate was given. From this study, it is found that the impact only affects heavily within the effect zone.     

真实的反映与表现——试比较王昌龄的边塞诗与大伴家持的防人歌的异同

王昌龄是唐代著名边塞诗人，大伴家持是日本奈良时期著名诗人，他创作了一些防人歌。从戍边这一内容来看，王昌龄的边塞诗与大伴家持的防人歌在题材上具有一致性。但由于各自的文化背景、个性气质、艺术追求不同，王昌龄的边塞诗与大伴家持的防人歌在风格、表现手法、情与景的相互关系上又有所不同。但无论是同还是不同，王昌龄的边塞诗与大伴家持的防人歌都是真实地反映现实，表现自我的思想情感，具有很强的真实性。     

A generalized plane strain theory for transversely isotropic piezoelectric plates

INTRODUCTION For moderate thickness plate containing notches or holes, neither plane stress nor plane strain theory can describe its true deformation states (Jin and Hwang, 1989). This well known drawback has mo- tivated many analytical and numerical studies carried out to determine the effect of plate thickness on the in-plane stress distribution. Pioneering work on the along depth stress components, i.e. the K-M gener- alized plane strain theory was proposed by Kane and Mindlin (1956)…     

Alfred Wegener—From continental drift to plate tectonics

What is the nature of the force or mechanism that moves massive continents thousands of miles across? What causes violent earthquakes to displace huge landmasses abruptly? How could great mountain ranges like Himalayas and Alps rise to such incredible heights? What makes earth's interior so restless? Answers to some of these questions may lie in understanding the Earth's interior itself.