With the development of society and the economy, there is an increasing demand for surface treatment techniques that can efficiently utilize metal materials to obtain good performances in the fields of mechanical engineering and the aerospace industry. The laser metal deposition (LMD) technique for cladding has become a research focus in recent years because of its lower dilution rate, small heat-effect zone and good metallurgical bonding between the coating and substrate. This paper reviews the simulation technology for the melt pool’s grain growth mechanism, temperature and stress distribution that are directly related to defect formation in LMD technology. At the same time, the defect suppression method and the performance improvement method of the cladded layer in LMD technology are introduced. Finally, it is pointed out that the active selection of materials according to the required performance, combined with the controllable processing technology, to form the corresponding microstructure, and finally, to actively realize the expected function, is the future development direction of LMD technology.

Spectral drift of any origin consisting of detectors and nuclear electronics affects the long-term stability in a gamma-ray spectrometer, which is essential to maintaining the high quality of gamma energy spectra. The feedback regulation according to the quantity of spectral drift can restore the system’s stability. A new algorithm for spectral drift calculation is given in this paper. A digital logic unit is developed in a FPGA chip based on the algorithm, and a MCU coordinating with it can fast calculate the spectral drift within only less than 110 instruction periods.

A direct numerical simulation of single plume flow in thermal convection with polymers was carried out in a domain with 1:3 as the width to height ratio. The heat transport ability is weakened by adding polymers within the here-investigated governing parameter range. However, it is promoted when the maximum polymer extension L is increased. The distribution of vertical velocity and temperature indicates that the plume in the polymer solution case is speeded up and widens bigger as compared to that in the Newtonian fluid case. Inside the plume, polymer chains tend to release energy at the position where the velocity is decelerated. The ratio of Nusselt numbers (Nu/NuNew) shows the power-law scaling relation with the governing parameter L2/Wi in polymer solution cases, which is only applicable for moderate Wi and small L. The present study can give direct insight into the observation about plumes in turbulent thermal convection experiments. It is therefore useful for the analysis of heat transport in thermal convection with polymers.

The paper describes a method to forecast the cohesive zone of blast furnace whose shape is very important for the quality of iron and the efficiency of iron-making industry. This method builds a model that can be observed during the operation of iron making. The model considers that during the chemical reaction the ore, the coke and the gas abide by two equations: the equation of conservation of mass and the equation of heat conservation. Based on this presumption, by dividing the blast furnace into a series of homocentric circles in the height direction and resolving the equations in every homocentric circle with its own parameters, we can get the relationship between temperature and height of the inner blast furnace. And then, according to the fusibility character of the ore, we can forecast the shape and position of the cohesive zone. Finally, the paper visualizes the cohesive zone of blast furnace and discusses some results achieved through the application of such method to a real blast furnace.