The multistage goal programming model is popular to model the defense projects portfolio optimization problem in recent years. However, as its high-dimensional variables and large-scale solution space, the addressed model is hard to be solved in an acceptable time. To deal with this challenge, we propose an improved differential evolution algorithm which combines three novel strategies i.e. the variables clustering based evolution, the whole randomized parameters, and the child-individual based selection. The simulation results show that this algorithm has the fastest convergence and the best global searching capability in 6 test instances with different scales of solution space, compared with classical differential evolution algorithm (CDE), genetic algorithm (GA) and particle swarm optimization (PSO) algorithm.

The technology of Reinforced soil has been widely used in civil engineering, its theory has some development . However, there is nearly any study about the theory of Geogrid-reinforced fly ash .In this paper, study the interface characteristics between fly ash and geogrid through the pull-out test,reach the following conclusions:the size of normal stress and water impact the interface parameters between the geogrid and fly ash;the interface friction coefficient between Geogrid and fly ash is small,adding gravel to fly ash can improve the interface friction coefficient between geogrid and fly ash.

Geogrid-reinforced retaining wall is widely used in civil engineering, the role of geogrid reinforcement and the calculations of reinforcement material in the retaining wall design need further refinement.This paper analyzes the fly ash retaining wall with and without reinforcement by using finite element software of FLAC3D,studys the impact of geogrid-reinforced function on the stability of fly ash retaining wall ,gets the design parameters of geogrid-reinforced fly ash retaining wall.The numerical results show that: the fly ash retaining walls' safety factor is lower when its height is greater than 6m,reinforcement is needed for fly ash retaining wall to improve its safety factor to ensure the stability of retaining wall.Simulate and analyze the 8m high geogrid reinforced fly ash retaining wall,the results show that: increasing the reinforcement spacing can increase the lateral and vertical displacement of geogrid reinforced fly ash retaining wall, the maximum vertical displacement of retaining wall is in the upper wall,maximum lateral displacement occurs in the lower parts of the retaining wall;the reasonable distance of 8m high fly ash retaining wall is 0.8m.

Microorganisms to improve oil recovery technology is a comprehensive technology of using beneficial activities and metabolites to enhance oil recovery. The obvious effect of field application and good economic benefits make it be active in the field of oilfield development in the long term. In this paper, through indoor experiments in different concentrations of microorganisms bacteria, different concentrations of nutrient solution and function time, evaluate oil sands de-oiling efficiency. Based on test results, optimize the compound of bacteria that from different sources and find out when the ratio of field and lab bacteria is 1:7, the de-oiling efficiency reach the peak of 86.47%, which further expand the mechanism of microorganisms enhanced oil recovery.