A Study of High-Temperature and High-Pressure Experiment of Correlativity between Deformational System of Au-Bearing Rocks and Element Adjustment

Modelling of migration and accumulation of elements Au and Ag in rocks under temperatures of 350–450°C and a confining pressure of 300 MPa and axial pressure of 100–150 MPa is conducted. It is found that the contents of gold and silver get higher in metallic sulphides such as pyrite, chalcopyrite and sphalerite as well as in quartz and muscovite, and get lower in chlorite, biotite, seriate, albite and calcite, showing that tectono-dynamics is one of the important factors for petrogenesis and metallogenesis.

A three-dimensional nonlinear reduced-order predictive joint model

Mechanical joints can have significant effects on the dynamics of assembled structures.However,the lack of efficacious predictive dynamic models tot joints hinders accurate prediction of their dynamic behavior.The goal of our work is to develop physics-based,reduced-order,finite element models that are capable of replicating the effects of joints on vi- brating structures.The authors recently developed the so-called two-dimensional adjusted lwan beam element(2-D AIBE) to simulate the hysteretic behavior of bolted joints in 2-D beam structures.In this paper,2-D AIBE is extended to three-di- mensional cases by formulating a three-dimensional adjusted lwan beam element(3-D AIBE).hupulsive loading experi- ments are applied to a jointed frame structure and a beam structure containing the same joint.The frame is subjected to ex- citation out of plane so that the joint is under rotation and single axis bending.By assuming that the rotation in the joint is linear elastic,the parameters of the joint associated with bending in the flame are identified from acceleration responses of the jointed beam structure,using a multi-layer teed-torward neural network(MLFF).Numerieal simulation is then per- formed on the frame structure using the identified parameters.The good agreement between the simulated and experimental impulsive acceleration responses of the frame structure validates the efficacy of the presented 3-D AIBE,and indicates that the model can potentially be applied to more complex structural systems with joint parameters identified from a relatively simple structure.

Design of Lower Limbs Powered Exoskeleton

In order to lighten the burden of health care workers and help people with Lower limb insufficiency to do rehabilitation training, this paper designs a model named exoskeletons rehabilitation robot to simulate the human gait, including exoskeletons and scooter structure, and designs the driver module. Finally, this paper uses Workbench software to do the stress and strain analysis, which validates the reliability of the whole design.

Recent Advances on the Corrosion Resistance of Low-Density Steel:A Review

This paper reviews the previous literature on the alloy composition design of low-density steel(LDS),focusing on the eff ect of Al,Mn,Ni,and other alloy elements on the formation of the steel matrix and second phase,and provides classifi cation.The microstructure of LDS after processing includes the matrix structure,к-carbide,and B2(FeAl,NiAl,or MnAl)phase of ferritic LDS,austenitic LDS,and dual-phase LDS.The infl uence of alloy elements on the corrosion resistance of LDS is derived from the addition of Al and Mn for metallurgy.Additionally,the infl uence of Cr and Mo addition on the corrosion resistance improvement was studied.The electrochemical properties of the corrosion process in LDS are discussed.Further,the microstructure of LDS aff ects the corrosion resistance properties including pitting corrosion,hydrogen embrittlement,and SCC(stress corrosion cracking).Finally,future research directions are proposed.