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Based on modal decomposition, an explicit formula for edge resonance solution in circular cylinders is presented here. Using the bi-orthogonality relation and singular value decomposition, the method could get the exact edge resonance frequency of circular cylinders. The calculation results are compared with numerical simulation results for verification.

Two methods based on modal decomposition in circular cylinders are presented here. One is based on bi-orthogonality relation and the other is based on boundary discretization for mode matching. The two methods are comprised in numerical implementation and the efficiencies are evaluated.

As the competition for steel department becoming fierce, the custom bring forward more district requirement. When deal with the quality dissidence, jingtang company find many dissidence is result in elongation does not meet the set point, bring too much economic damnify. So the author analyzed the technology of elongation and the control system, tested the stiffness of the tempermill, finally optimized the control system and the minimum roll force and the tension of temper according the analysis result, find a property technology for this kind of strip to product.

The paper introduced the Bayesian networks briefly and discussed the algorithm of transforming fault tree into Bayesian networks at first, then regarded the structures impaired caused by tunnel blasting construction as a example, introduced the built and calculated method of the Bayesian networks by matlab. Then assumed the probabilities of essential events, calculated the probability of top event and the posterior probability of each essential events by the Bayesian networks. After that the paper contrast the characteristics of fault tree analysis and the Bayesian networks, Identified that the Bayesian networks is better than fault tree analysis in safety evaluation in some case, and provided a valid way to assess risk in metro construction.

The coarsening kinetics of main strengthening phase γ′ and the growth behavior of grain boundary carbides have been investigated on NiCr20TiAl alloy aged at 550~750°C for 200~10,000h. The precipitates of NiCr20TiAl alloy at standard heat treatment condition are γ′, M7C3, M23C6 and MC. The coarsening of γ′ precipitates proceeds by Ostwald ripening controlled by volume diffusion in the alloy. Grain boundary carbides M23C6 and M7C3 increase with ageing times and temperatures. The morphologies of precipitates after long-time ageing almost remain the same as that at standard heat treatment condition except 750°C.

This paper presents the experimental and numerical results of the ultimate bearing capacity of partially overlapped tubular N-joints, which have circular hollow section (CHS) brace members welded to a square hollow section (SHS) chord member. Two partially overlapped N-joints were tested to failure under overlapping brace axial loading and chord axial loading. The failure mode of specimen N1 was the overlapping brace local bucking, and the failure mode of specimen N2 was the chord face plastification with chord side wall buckling. Meanwhile, weld fracture occurred on both specimens. Then, making use of finite element package program ANSYS, in which twenty nodes solid element was employed and the weld was simulated, elastic-plastic large deflection finite element analysis of the experimental joints was conducted. The experimental data were compared with the results acquired by finite element analysis and it was proved that ANSYS is feasible to simulate the connecting weld and analyze the static behavior of partially overlapped CHS-to-SHS welded N-joints.

Brief description of the basic idea of semi-rigid joints is given. Several types of joints are showed combined with the development of the study in recent years. The classification and design methods of semi-rigid joints in steel structure design specifications of the USA , Europe , Canada , Hong Kong are introduced and discussed. Several problems to be studies and the way of further research directions are given.

Zinc oxide (ZnO) microrods were grown by the floating zone method, the as-grown ZnO microrods have uniform size. Scanning electron microscope image reveals that the ZnO microrods are grown with a hexagonal structure, well faceted ends and side surfaces. Most of ZnO microrods have diameters of about 20-30 mm and lengths of about 1-2 mm. Polarizing microscopy image of ZnO microrods shows that they have high crystal quality. The X-Ray diffraction pattern shows that microrods have vertical orientation and the crystal structure of ZnO is wurtzite type. At low exciting intensity, ultra violet range emission was found and the growth process of ZnO microrods was discussed.

The article was based upon analysis of the front-and-back surface vibration velocity of the working surface by monitoring the blasting operation at hidden digging section of Jiaozhou Bay cross-harbour tunnel in Tuandao road exit ramp. Research shows that the maxim-um value of the surface blasting vibration velocity appears on the front and back of the ground ,raging from 2 m to 7 m ,just above the working surface instead of the ground just above of the working surface. However, the surface vibration velocity generates behind the working surface was 1.2 to 1.4 times greater than the one generates at the front of the working surface. The front-and-back surface vibration velocity tends to be flattening on the ground which was more than 20 m away from the working surface, just above it.