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In response to mobile terminal threats, this work is innovative, and gives practical solutions and prototype systems. The work first analyzes in detail the entire process of the generation, transmission and use of user-sensitive data within the Android system. In order to achieve resource sharing and data transmission between different applications and processes, the Android system provides a mechanism for inter-process communication based on Binder. Sensitive data is transmitted through Binder as a channel in the system. But sensitive data is carried out in the form of clear text during Binder transmission, which allows malware to easily intercept and tamper with sensitive data based on Binder communication, such as SMS content and GPS location information. In response to this problem, based on the above research, this work innovatively proposes and implements an adaptive transparent encryption protection scheme for sensitive data in the Android system from generation to use throughout the life cycle, effectively preventing sensitive data from being. The threat of theft and tampering by malicious third parties guarantees the privacy and integrity of user sensitive data during the internal transmission of the system. In addition, the system provides users with a simple and flexible operating experience, allowing users to independently protect specific types of sensitive data in specified applications, enhancing the ease of use and practicality of the system.

Based on data collected by Chinese Civil Aviation Statistic Center, the annual CO2 emissions of aircrafts during 1960–2009 were calculated, and the emission intensity and its dynamic characteristics were analyzed. The results show that the total CO2 emissions of aircrafts in China increased from 120×103 t in 1960 to 41.44×10s t in 2009. The CO2 emission intensity decreased from 2.9 kg (converted t km)−1 in 1960 to 0.96 kg (converted t km)−1 in 2009 at an average rate of 0.04 kg (converted t km)−1 per year. The average share of CO2 emissions of aircrafts on the total CO2 emissions from the sector of transportation, storage and post was 6.6% during 1980–2005, and 0.25% on the total emissions from fossil fuel combustion during 1971–2008. Citation He, J.-C., and Y.-Q. Xu, 2012: Estimation of the aircraft CO2 emissions of China’s civil aviation during 1960–2009. Adv. Clim. Change Res., 3(2), doi: 10.3724/SP.J.1248.2012.00099.

Aluminum industry is one of the most important industries in China’s nonferrous metal metallurgy industry. With the development of output in alumina and the improvement of its production technology, China’s high quality bauxite resources are difficult to meet. Under this condition, “Calcification-Carbonation Method” was put forward to deal with middle-low grade bauxite and red mud by Northeastern University, the main purpose of this method is to change the balance phase of red mud into 2CaO•SiO2 and CaCO3 with hydrometallurgical process. Through treatment by “Calcification-Carbonation Method”, A/S of the new structure red mud lowed below to 0.5 and the Na content lowed below to 0.3%, the red mud could be used in cement industry directly. This paper mainly introduced the technological idea and principle of new method, process comparison and typical experiment results is given as well.

Research on the leaching performance of fly ash of Shanxi, Chongqing and Western Inner Mongolia. Analyze the existing forms, crystallinity and package situation of Al-Si phase in fly ash from different areas by using SEM and XRD. Effect of fractionation of Al-Si phase in fly ash on the leaching performance from the view of mechanism was investigated as well. Leaching experiments and analysis indicate that: the leaching rates of Al203 in fly ash from the there different areas are 97.41%, 68.94% and 23.61% respectively, under the conditions of solid-liquid ratio 1:20, rotary speed 500rpm, leaching time 120min, sulfate concentration 20%, particle sizes −74µm. Leaching performance of fly ash in Western Inner Mongolia is better than that in other two areas. The main reason for different leaching performance of fly ash from different areas is the difference in crystallinity, encapsulated glass phase of Al-Si phase in fly ash. The crystallinity for Western Inner Mongolia is 75.98%, while there is no non-crystalline phase in fly ash from other tow areas, The average FWHM of XRD diffraction peak of Al-Si phase are 0.641, 0.3324 and 0.1107, respectively. The crystallinity of fly ash in Western Inner Mongolia is worst among the there areas, and its content of glass phase is also lowest among them, so its activity is obviously higher than that of other two areas.

The suspension and dispersion of Al(OH)3 particles in seed precipitation tank, which may affect the quality and output of alumina besides the deposit on the bottom of the tank, is one of the key steps in Bayer process. In order to solve these problems, the solids concentration profiles of Al(OH)3 particles were investigated by cold water experiments under simulated industrial conditions. The results showed that, the mixing uniformity in the whole tank improved with the increase of impeller off-bottom clearance when used the impeller of small diameter (D / T ⩽ 0.6), and it deteriorated when enlarged the impeller (D / T = 0.65 ~ 0.7). The mixing effects can be improved by increasing the impeller diameter and stirring speed, meanwhile the influence of impeller off-bottom clearance was weakened. But the impeller diameter and stirring speed should be controlled in appropriate ranges for the consideration of power consumption and mixing efficiency.

Compared with the traditional cathode structure cell, the new cathode structure cell can restrain the level fluctuations of aluminum liquid, effectively reduce polar distance and decrease cell voltage, it makes greatly electricity saving into reality. In this paper, using cold water model experiment based on principle of similitude to study the level fluctuations by anode gas disturbance, and investigate the rules of level fluctuations in new cathode structure electrolytic cell. Numerical simulation of the anode structure with Fluent was also carried out. Simulation results are basically consistent with experimental results, which can verify possibilities of using Fluent to investigate fluctuations in the interface of cell. According to the analysis of experimental data, the empirical formula of amplitude are obtained by using dimensional analysis, which are associated to a variety of material factors, operating factors, equipment factors. After the theoretical analysis, Dimensionless equation is in good agreement with experimental results.

Compared to the conventional cathode structure electrolytic cell, the new type of cathode structure electrolytic cell can effectively inhibit the fluctuation of liquid aluminum, which can reduce the polar distance, decrease cell voltage, and save energy. A cold water model was designed according to scale of 1:3 with 160KA industrial electrolytic cell to examine aluminum liquid fluctuation induced by anodic gas in the new type of cathode structure electrolytic cell. High-speed photographs of the liquid interface waves show the effect of several cell parameters such as anode-cathode distance, electrolyte level, and gas flow rate. The study shows that in the new type of cathode structure electrolytic cell, the largest interface wave height will be reduced significantly.

This paper investigates the changes of phase and apparent morphology under the combined effects of an intense magnetic field and temperature field and the effect law of different roasting conditions on the digestion performance of roasted diaspore. The results indicated that roasting pretreatment under high magnetic fields can change the microstructure and improve the digestion properties of bauxite. The reasonable roasting conditions with intense magnetic field are as follows; the roasting temperature is 550°C, roasting time is 60min and the magnetic field intensity is 6T. The digestion rate of alumina of the roasted ore is 84.17% and the digesting liquid ratio is 1.39 while the digesting temperature is 190°C with the digestion time of 60mins. The digestion rate of alumina of the roasted ore increases to higher 52.85% than that of the raw ore, but the digesting liquid ratio is decreased to lower than 0.99 of the raw ore under the above roasting conditions. The digestion temperature of roasted ore decreases by 30°C compared to the raw ore.

A wavelet-Galerkin method is proposed for the computer simulation of transient behaviors of electrical machines. To consider the interaction with the external components of the frond end of the machine such as power electronic devices, the proposed wavelet-Galerkin method is combined with a state space model to develop an integrated simulation approach. An iterative procedure is also proposed to solve simultaneously the two system equations. Numerical results of computer simulations on the transient behavior of a prototype PWM inverter-fed motor drive are used to validate the feasibility of the proposed method for transient behavior simulation of general electromagnetic devices.

With the development of continuous casting technology,the quality of billet has been paid more and more attention recently.It is very important in continuous casting to strictly control the cleanliness of molten steel,and to reduce the defects of billet.The control of flow pattern of molten steel in mold is one of the important means to increase casting efficiency and improve billet quality.Swirling flow in the submerged entry nozzle(SEN) has great effect on improving the uniformity and stability of the outflow from the nozzle in continuous casting of steel process.A new process for swirling flow generation in the SEN has been proposed.That is a rotating electromagnetic field is set up around the SEN to induce swirling flow in it by Lorentz force.In this research,the flow and temperature fields in the SEN and round billet mold with electromagnetic swirling are numerically simulated.The effects of the divergent angle of the SEN with electromagnetic swirling on the flow and temperature fields in the mold are investigated.The simulated results show that,with the increase of the coil current intensity, the magnetic flux density and the swirling flow velocity in the SEN increases.The largest swirling flow velocity in the SEN can reach about 3 m/s in coil current intensity 500 A,frequency 50 Hz.In a divergent angle of the SEN,such as 60°,when the coil current intensity increases,the impinging depth of the outflow from the nozzle reduces,the upward flow velocity and the meniscus temperature increase. While the coil current intensity increases larger than 350 A,the meniscus temperature changes little. In a certain intensity of swirling flow,such as 350 A,50 Hz,when the divergent angle of the SEN increases,the upward flow velocity and the meniscus temperature firstly increase and then decrease. In divergent angle 60°,the upward flow velocity and meniscus temperature get the largest value.In a divergent angle 60°,coil current intensity 350 A,frequency 50 Hz.with an artificial uneven flow of 0.5 m/s horizontal velocity at the inlet of the SEN,the uneven flow can be suppressed effectively.

Inconel 625 is a Ni-Cr-Mo-Nb alloy which was developed primarily for high turbine applications. The elemental addition of Nb increases the solidification temperature range, which ex- hibits a strong propensity to form interdendritic segregation. The enrichment of elements Nb and Mo at the terminal stage of solidification leads to the formation of brittle eutectic structure, i.e., +Laves phases, which becomes potential crack origin during the subsequent hot processing and application. The present work has demonstrated that, the introduction of electromagnetic field (EMF) to the so- lidification process of Inconel 625 alloy has the obvious effect on grain refinement. The EMF can also effectively influence the segregation ratio of Nb and Mo. However, the inappropriate application of electric current intensity and frequency will lead to more severe segregation of elements Nb and Mo, which causes the increment of eutectic structure volume fraction. Further analysis illustrates that both of the grain refinement and eutectic volume fraction control the tensile property at room tem- perature, increasing the yield strength and decreasing the tensile plasticity for Inconel 625 alloy. It has been proven that a proper selection of input current intensity (100 A) and frequency (8 Hz) can effectively dominate the segregation behavior during solidification process under EMF with more than 30% increase of yield strength and a minute loss of plasticity.