Yumen oil sands were chosen as the experimental material to separated oil from oil sands through wet-grinding by light oil and washing treatment by washing agent. The tailing sands were characterized by XRD. The factors includingamount of light oil, amount of washing agent, concentration of washing agent, reaction temperature were also studied. The results showed under the reaction conditions of mass ratio of naphtha to oil sands 0.15, mass ratio of washing agent to oil sands 1.5, concentration of washing agent 8%,reaction temperature 80 ℃, the oil recovery could be up to 96.5%.

With the development of science and technology, more and more materials are coming out, at the same time,the demand for materials is increasing. Rare earth luminescent nanomaterials are different from conventional ones. They have the advantages of good physical and chemical stability, high temperature resistance, narrow luminescence band and high color purity which makes they show good prospect of applications in so many fields, such as light emitting devices, imaging and medicine and have become one of the hot spots. In this paper, the preparation and application of rare earth luminescent nanomaterials are reviewed, and the problems that need to be solved and the development prospects are discussed.

Liquefied petroleum gas belongs to dangerous gas, once the leakage occurs, the consequences are serious. So its security problem is very important. According to the characteristics of LPG leakage, a physical model of leakage and diffusion in the limited space was established, and the diffusion process of the gas leakage was simulated. The internal flow field of the diffusion process was analyzed through simulation results, and the different of the diffusion processes were compared under the different relative humidity. The results showed that due to the moving eddy in the air, the velocity vector of the gas diffusion change from one side was higher than the other side to the other side was higher. The increase of wind speed would accelerate the generation and movement of the eddy, and the concentration distribution of C₃H₈ would change acutely. When the air relative humidity increased, the gas descended faster, and in the plane below the leakage point, the humidity increased, the concentration of C₃H₈ was higher, the alarm time of the liquefied petroleum gas alarm device would be shortened.

The growth of sulfate reducing bacteria (SRB) under different magnetic field strength was studied by using microbial method. The corrosion rate of X100 steel in simulated solution of SRB steel under different magnetic field strength was calculated by the method of weight loss. It was found that the magnetic field could inhibit the growth of SRB, and the stronger the magnetic field intensity was, the stronger the inhibition effect was; The magnetic field could inhibit the corrosion rate of X100 steel, and the corrosion rate of X100 steel first decreased and then increased with the increase of magnetic field strength. When the magnetic field strength was 5 mT, the corrosion rate was the smallest. The influence of static magnetic field on the survival rate of microbe and the corrosion rate of metals were briefly introduced. A new idea for the inhibition of microbial corrosion in pipeline was proposed.

According to the application characteristics of current hard cable in cementing quality logging in cased wells, a variety of stress state in the logging is analyzed. Based on the principle of mechanical balance, a mathematical model of cable head tension during hard cable logging is established,and the calculation method of cable head tension is put forward.On this basis, the changes of cable head tension are calculated simulatelythrough the VBA programming examples.The influence of cable logging speed, hard cable length, and size structure on the cable head tension and depth are researched. The results show that the parameters of the well body structure is the decisive factor determining the distribution of the cable head tension and the depth of the cable, and the effect of increasing hard cable length and reducing hard cable outer diameter of cable on logging depth is not obvious.

In order to solve the problem that the pressure drop curve or the pressure recovery curve made by measured data was not fitting well with the classic model curve in low permeability reservoir, on the basis of previous studies and nonlinear flow of power law model, the method of differential discrete was used to build a quick and precise method for calculating the pressure, and the calculation method of dynamic permeability and conductivity was also investigated in detail. The factor of pressure curve model was analyzed by using control variable method. The result showed that the bigger the powerlaw index was, the greater the bending upwards magnitude of the pressure curve model was; with the coefficient of the wellbore storage and skin factor becoming larger, the reservoir fluid in low permeability reservoir cost more time to flow into steady flow; for closed boundary reservoir, the pressure model curve upturns and the reservoir resolution points were very clear. The pressure curve and the pressure derivative curve intersected. For the constant pressure boundary reservoir, it was on the contrary with the closed boundary reservoir, but after the fluid flows into the quasi steady state of radial flow, model curves were a cluster of parallel inclined lines.

The model and numerical simulation of three-dimensional non-isothermal for sol-gel reaction process of preparing PP/TiO₂ nanocomposites between mixing and reaction process in twin screw extruder were established by POLYFLOW software with the finite element method. The effects of screw speed, screw pitch and precursor concentration on the preparation of PP/TiO₂ nanocomposites reaction process about mixing efficiency and reaction rate were analyzed. The results showed that the increasing pitch which enhanced the temperature of polymer and improved mixing efficiency in twin screw extruder contributes to the reaction process. The increasing screw speed and precursor concentration were not conducive to the reaction, because of the drop of the fractional conversion.

This paper presents a control strategy of obstacle avoidance for nonfully constrainedmobilerobots in unknown environment.The avoidance of unexpected obstacles is consideredin a reactive way by following the contour of the obstacles.The robot backwardsmotions are avoided and the robot heading is always in the direction of thegoal point facilitating the obstacle handling. The stability of obstacle avoidance is analyzed under the reasonable conditions. Finally, the goodperformance and the feasibility of this approach are shown through several experimental results.

The 8 representative financial indexes were selected to do an empirical study on the financial performance of the real estate listed corporation in 2013 for understanding the financial situation of the real estate industry. Firstly, the scores and ranks of the financial performance of the enterprises were obtained by using the factor analysis method, then the paired samples T test was done on the top ten and the last ten enterprise performance score. The results showed that the effect of profit ability and development ability were obvious to enterprise performance, but the effect of the operation ability and the cash ability were existed, but the effect was not obvious.  

Cost-efficiency is a key factor affecting comprehensive competitive ability of commercial banks. The stochastic frontier analysis method was used combining with the CobbDouglas function to estimate the costefficiency value of 16 listed commercial banks of our country in 2005-2013, and then to the panel data which were obtained by the horizontal longitudinal analysis. The results showed that the cost-efficiency was affected by factors such as size and configuration, the level of cost-efficiency of city commercial banks, national joint-stock commercial banks and state-owned commercial banks was reducing. Thus suggested that large commercial banks needed to learn the experience of efficient management from the small and medium-sized commercial banks in such aspects as manpower, configuration and technology, at the same time, the small and medium-sized commercial banks should also learn the experience of scale expansion and accumulation of strength from the big commercial banks. Banks should foster strengths and circumvent weaknesses in order to further improve cost efficiency and achieve better and faster new growth.