Abstract: Multi-model adaptive control, as an improved method of classical adaptive control, can effectively solve the control performance issues for the complex systems with large parameter uncertainties. It has attracted increasing attention from scholars, and a vast array of research results have been achieved in theory and practice. According to the different synthesis methods of multiple local controllers corresponding to the multiple local models, the multi-model adaptive control scheme can be divided into different categories. This paper provides a survey of weighted multi-model adaptive control (WMMAC). The basic idea of the WMMAC is to adopt the method of “divide and conquer”; multiple local models and corresponding multiple local controllers are established offline, and the control outputs of local controllers are integrated online, such that the global control law can be formed. The WMMAC is a promising method to achieve strong robustness and a self-adaptive ability for control systems. First, we presented the development process and the main problems of the WMMAC. Then, the research status of control systems and the latest progress were shown, including model set construction and weighting algorithm design. To improve the rationality of model set construction, WMMACs with self-tuning model and even a dynamic model set have been developed. Meanwhile, to reduce the calculation burden, a new weighting algorithm has been designed, which is based on the model output errors of the multi-model adaptive control system. Especially for system stability analysis, which has always been a recognized problem in the WMMAC system, some research results have been obtained. The proof of system stability in the general sense has been given preliminarily by introducing the theory of virtual equivalent system. This paper gave a review of WMMAC in the order of the variation on the structure, the development of algorithms and its applications. Furthermore, the main problems in the control system were analyzed, and some potential research directions, which are the difficulties and emphases of future research including model set, weight calculation, disturbance rejection, stability, were pointed out.
Abstract: Production scheduling is one of the key technologies in steel manufacturing process. It plays a significant role in reducing the production cost and improving the production efficiency of iron and steel enterprises. In recent years, with the rapid development of intelligent steel-manufacturing technology, production scheduling has attracted increasing attention and become a research hotspot in the field of iron and steel metallurgy. The process of production scheduling in the process of steelmaking?continuous casting was summarized and discussed through reviews of previous researches, and the characteristics and application scopes of various methods were compared and classified. Typical cases of the computer-aided scheduling system in domestic and overseas steelmaking plants were discussed, and the characteristics of each system were studied and analyzed comparatively. On the basis of the previous studies, forward-looking strategies and a methodology of production scheduling were proposed for the future study of steelmaking?continuous casting process. For static scheduling, a new concept “rules + algorithm” was proposed, and a scheduling model construction method based on the production mode optimization of a steel mill was developed for a domestic special-steelmaking plant as a case study. For dynamic scheduling, multi-process collaboration was suggested, and a collaborative control method based on multi-agent was proposed. This method was developed for multi-process control, quality control, and scheduling control of the steelmaking-continuous casting process. An optimized and effective method for modeling and solving is one of the important means to solve the production-scheduling problem, aiming at improving the levels of setting up production plan and the feasibility of production planning. Meanwhile proposed method for modeling and solving can strengthen the on-site real-time control in steel mills and is of great significance to realize stable, orderly, and continuous operation in steelmaking-continuous casting process.
Abstract: At present, the steel industry has become the focus of air pollution prevention and control. To solve the difficulty in collecting PM2.5 fine particles and achieving ultra-low emission of dust, based on the method of computational fluid dynamics-discrete phase model (CFD-DPM), the influence of different magnetic field forms, such as magnetic field generated by magnetic fiber and high-gradient magnetic field, on the performance of PM2.5 collection in the iron and steel industry was studied. Through X-ray diffraction (XRD) analysis, it was found out that the dust produced in the iron and steel industry production process has magnetic characteristics due to the presence of Fe3O4 and elemental Fe, furthermore, the method of using magnetic field to enhance the PM2.5 collection performance of single fiber was proposed. The results show that the magnetic field generated by the magnetic fiber will form a gravitational region around the fiber, and the high-gradient magnetic field will form two gravitational regions and two repulsive regions around the fiber. In terms of the collection ability, when particle diameter dp between 0.5 and 1.0 μm, inlet velocity v≤0.2 m·s?1, the collection ability of magnetic fiber under the high-gradient magnetic field is stronger than that of the single magnetic fiber. If magnetic field intensity H=0.5 T, magnetic induction intensity B=0.01 T, and v=0.1 m·s?1, the high-gradient magnetic field can improve the single fiber collection efficiency by 28.32 times as much as the original; if B=0.01 T, v=0.1 ms?1, the magnetic field generated by the magnetic fiber can improve the single fiber collection efficiency by 4.037 times as much as the original. In terms of the collection law, in the magnetic field generated by the magnetic fiber, when the magnetic flux density B≥0.03 T, the collection efficiency of magnetic single fiber on PM2.5 decreases with the increase of inlet velocity speed and then tends to be stable. When B<0.03 T, the collection efficiency decreases with the inlet velocity speed. The collection efficiency increases with the increase of dust particle size. For the high-gradient magnetic field, the single fiber collection efficiency of PM2.5 particles also decreases with the increase of inlet velocity speed. When v>0.4 ms?1, the collection efficiency is 0. The larger B is, the faster the collection efficiency decreases. The collection efficiency increases first and then decreases with a increase in dust particle size.
Abstract: With the development of the iron and steel industry, the amount of NOx emissions is increasing year by year, and this causes environmental pollution in forms such as acidic rain and photochemical smog, which greatly threatens human health and social development. The iron and steel industry is one of the major sources of NOx emissions, accounting for more than 10% of the total NOx emissions, and the iron ore sintering process is one of the major sources of NOx emissions in the iron and steel industry, as it accounts for more than 50% of the total emissions of iron and steel plants. Hence, it is extremely urgent to reduce NOx emissions under the current high requirements of environmental protection. Since sintering gas is characterized by large volume, high dust and oxygen content, low NOx concentration, and the presence of SO2, available technologies used in De-NOx have the disadvantages of low efficiency and high investment and cost. Presently, how to cost-effectively reduce the NOx emission of the iron ore sintering process is a new challenge in the iron and steel industry. In the sintering process, NOx is mainly generated in the combustion of solid fuels, which is affected by the existing states of coarse solid fuels. Hence, the combustion behaviors of uncovered and coated coarse coke breeze and the effects of their addition methods on the NOx emission and the bonding strength of the sinter were investigated by the visible micro sintering and combustion equipment. Then, the optimal existing state of coarse coke breeze was explored by sinter pot tests. The results show that compared with the uncovered coarse coke breeze, the NOx emission decreases by 56% when coarse coke breeze is coated with calcium ferrite fines. As the coarse coke breeze is separated and controlled to be in an uncovered state, then it is added into the sintering materials after first mixing process, NOx emission increases by about 56% and the strength of the sinter decreases. The maximum concentration of NOx and conversion rate of N element decrease by 8% and 27%, respectively, when the coke breeze is a coated state by controlling in the size of 0.50?3.15 mm, respectively. The sinter indexes are also improved.
Abstract: With steel slag and biomass waste material as the research object, biomass waste material was modified by metal oxide in steel slag to obtain ecological activated carbon. The influences of steel slag type, grinding time of steel slag, and the amount of steel slag ultrafine powder on the formaldehyde degradation performance of ecological activated carbon were studied. The chemical composition of steel slag, mineral composition of steel slag, particle size distribution of steel slag, structural composition of steel slag ultrafine powder, the pore structure of ecological activated carbon, and the microstructure of ecological activated carbon were characterized by X-ray fluorescence X-ray diffraction, laser particle size distribution analysis, Fourier-transform infrared spectroscopy, Brunauer-Emmett-Teller analysis, and scanning electron microscopy, respectively. The results show that the prepared ecological activated carbon show good formaldehyde degradation performance and reasonable economy; the degradation rate of formaldehyde after 10 h is 57.5%; when steel slag is electric furnace slag, the grinding time of the steel slag is 90 min, and the amount of steel slag ultrafine powder is 20 g. High contents of Fe and Mn were present in the electric furnace slag. Iron promoted the concentration of a large amount of formaldehyde in the porous structure of activated carbon, and Mn catalyzes the degradation of enriched formaldehyde, realizing the synergistic effect of adsorption degradation and catalytic degradation. Appropriately extending the grinding time of the steel slag can significantly reduce the particle size of the steel slag ultrafine powder and improve the particle size distribution uniformity of the steel slag ultrafine powder, which is beneficial to increasing the degradation area of steel slag ultrafine powder, activated carbon, and formaldehyde. An appropriate amount of steel slag ultrafine powder can improve the pulverization rate of ecological activated carbon and offset the decline of activated carbon adsorption performance due to the decrease of porosity and specific surface area of the activated carbon.
Abstract: The lead-cooled fast reactor (LFR), which features advanced technical maturity and enhanced safety, is an important part of the fourth-generation nuclear power system of China. The superior safety of the LFR results from the choice of a relatively inert coolant, the lead or lead-bismuth eutectic (LBE), which can be rather corrosive to common metallic structural materials. Furthermore, there is basically no cladding material available for the LFR. Austenitic stainless steels feature a combination of excellent corrosion resistance, proper strength, and good workability, and materials such as 316Ti and 15-15Ti, which have been used in the sodium-cooled fast reactor (SFR), are viewed as promising candidate materials for LFR cladding applications. Elements of Cr and Si have been found capable of improving the corrosion resistance of 316Ti and 15-15Ti to LBE. However, as ferrite-forming elements, the influences of Cr and Si on the microstructural stability of 316Ti and 15-15Ti are still unclear. In this work, 316Ti-based materials with various Cr and Si contents were studied through thermodynamic simulation and microstructural characterization. Specifically, the equilibrium phase constitutions of the austenitic stainless steels were investigated by thermodynamic simulation using Thermo-Calc. The solidification microstructures and precipitates of Cr- and Si-bearing austenitic stainless steels were studied by optical microscopy (OM), scanning electronic microscopy (SEM), electronic differential system (EDS), and X-ray diffraction (XRD). The results show that Cr and Si can decrease the solidus and liquidus temperatures of alloys and induce the precipitation of δ-phase. For alloy 18Cr?2.0Si?15Ni, the maximum contents of Cr and Si are determined to be no more than 18.8% and 2.55%, respectively, which hinders δ-phase precipitation. In the ingot of 20Cr?2.0Si, δ-phase is found to be located within dendrites in a skeleton morphology, with a volume fraction of 8.6%, whereas in the ingot of 18Cr?2.5Si, δ-phase precipitates between dendrites, with a volume fraction of 3.4%. Moreover, this work also evaluates two kinds of austenitic stainless steel solidification path criteria.
Abstract: The mold is the core component of a continuous caster, and the complex metallurgical behavior in the mold is the primary factor determining the quality of continuous casting slabs. The numerical simulation method based on meshing, such as the finite element method, has become an important method to study the complex heat transfer and mechanical behavior in the mold. With in-depth research, the meshing-based numerical simulation method has been found incapable of accurately reconstructing the solidified shell shape of slabs and tracing the liquid-solid phases coexisting region, and addressing some complex problems such as large deformation and crack propagation is difficult. To investigate the feasibility of the meshless method for solving the solidification process of continuous casting billet, according to the moving least square method and variational principle, a two-dimensional unsteady transient heat transfer mathematical model of billet solidification process in mold was established based on element-free Galerkin method. In this work, an arrangement of the uniform, increased density, and randomly distributed nodes was used to calculate the change of temperature field during the billet solidification process. The calculation results of the element-free Galerkin method were compared with the reference solution and the numerical solution of the finite element method. The results show that the element-free Galerkin method outperforms the finite element method in terms of accuracy, adaptability, and mesh-dependence. The study results provide references for applying the meshless method to the numerical calculation of heat transfer, solidification, and stress/strain behaviors in the continuous casting process.
Abstract: During the production of Al-killed titanium-alloyed interstitial free steel, to reduce defects in cold rolled sheets and decrease the influence of inclusions on the properties of the steel, it is important to clarify the distribution of inclusions in the thickness direction of IF (interstitial free) steel along the slab. In this study, standard metallographic techniques were employed to analyze the total oxygen and nitrogen by performing scanning electron microscopy, energy spectroscopy, automatic scanning electron microscopy, and original morphology analysis. The results show that the average mass fractions of T.O and N are 1.6 × 10?5 and 1.7 × 10?5, respectively, and the T.O for the 1/8 thickness from the inner arc is 2.0 × 10?5, while the content of N for between the 1/4 and 3/8 thickness from the inner arc is 1.8 × 10?5. A total of 1177 inclusions were counted. More than 70% of inclusions are within 5 μm in size, and the average size of inclusions in the thickness direction is 2.8 μm. The sizes of inclusions for the 3/8 thickness from both the inner and outer arcs are larger at 4.0 μm and 4.4 μm, respectively. The amount of precipitation of TiN is large in the slab center, and there are mainly Al2O3 and Al2O3–TiOx near the inner and outer arc surfaces with sizes between 5 and 10 μm. Al2O3–TiN distributes irregularly in the 1/4 thickness from the inner and outer arcs, and the size fluctuates between 3 and 5 μm. The size of TiN during solidification fluctuates between 3 and 6 μm. TiN precipitates in the liquid and δ phase of the solidification front when the solidification rate is between 0.646 and 0.680, and the size fluctuates between 3 and 6 μm.
Abstract: Developing new technologies that can utilize CO2 as a resource or reduce CO2 emission is an urgent need in the iron and steel industry. The Ruhrstahl-Heraeus (RH) refining process can effectively remove gas and inclusions from molten steel by applying a high vacuum and intense circulation flow of the molten steel. Meanwhile, at the steelmaking temperature, CO2 can react with carbon in the molten steel to generate CO bubbles, and this enhances the molten bath stirring strength. Therefore, a technology involving the use of CO2 as the lifting gas in RH refining was proposed. To study the applicability of CO2 in RH refining, the favorable conditions and limits of CO2 decarburization under vacuum conditions were analyzed through thermodynamics. Meanwhile, an industrial test platform for CO2 as RH lifting gas was set up, and the effects of CO2/Ar as lifting gas on the refining process of molten steel were comparatively studied through industrial tests. The results show that if only the reaction between CO2 and carbon is considered, CO2 can still oxidize carbon elements when the carbon content is less than 1.8×10?6. However, CO2 selectively oxidizes carbon and aluminum in molten steel. When the aluminum content is below a certain level, CO2 mainly participates in a decarburization reaction; otherwise, CO2 will cause certain aluminum loss. Therefore, if the new process is adopted, the timing and amount of aluminum alloy addition should be considered. In addition, CO2 can be used as RH lifting gas to obtain a dehydrogenation effect equivalent to or even better than that of Ar. Meanwhile, injecting the same amount of CO2 did not cause a large temperature drop of molten steel; therefore, CO2 has the potential to be used as RH lifting gas to complete refining.
Abstract: Nuclear-grade zirconium alloys are characterized by large deformation resistance, poor fluidity, strong viscosity, and narrow forming temperature range. They are widely used in the nuclear industry and are a good choice for structural components and fuel cladding materials for nuclear power reactors. Reasonable process parameters and tooling design are very important for the production of zirconium alloy products with excellent performance. Simulation is an important technical means in plastic forming process and tool structure optimization. A prerequisite for accurate simulation is to determine precise boundary conditions, such as friction factors in plastic forming process. In this study, the friction factors under the lubrication condition of Zr-4 alloy were determined by ring compression and extrusion simulation method. The reasons for the difference in friction factors measured by the two methods were discussed. The results show that when the roughness of the die (anvil) is Ra = 0.6 μm and the experimental temperature is 700?800 ℃, the friction factor between the Zr-4 alloy and the die obtained by the ring compression is 0.18?0.27, and the friction factor increases with increasing in the experimental temperature. When the extrusion temperature is 750 ℃, the average friction factor of hot-extrusion obtained by extrusion simulation is 0.35. The reason for the large difference in the test results is that the shear rate of the lubricant in the extrusion process is much larger than that of the ring compression experiment, and the compressive stress of the lubricant in the extrusion process is about twice that in the ring compression experiment, which leads to an increase in the lubricant viscosity so that the friction factor is higher. The friction factor obtained by the ring compression method is more suitable for hot working conditions such as the forging of Zr-4 alloys.
Abstract: With the advantages of both Cu and Al, including high conductivity, good corrosion resistance, low density, and easy connectivity, Cu–Al-laminated composites become a substitute for copper plates which can be applied widely in the fields of telecommunication, the petrochemical industry, transportation, decorative buildings, and the aerospace, national defense, and military industries. Cu–Al-laminated composites can be prepared via various methods, such as the explosive combined method, rolling combined method, and cast-rolling combined method. However, all these methods are limited because of the complicated metal surface treatment which poses a restriction on the development of this kind of plate. To resolve this issue, a new process of horizontal continuous casting composite forming (HCCF) for bimetal composite plates with an interface of metallurgical bonding, which is regarded as a short and more efficient process, was presented in this paper. Cu–Al composite plates with a section size of 70 mm × 24 mm (width × thickness) were fabricated, whose feasible preparation parameters were further studied, along with the investigation of the microstructure and properties of the composite plate. The results show that consisting of intermetallic compounds and eutectic phase, an interfacial layer is formed during the preparation and formation of the Cu–Al composite plate. Layer II of θ is formed via a solid–liquid transition during the solidification of liquid Al on the solid Cu plate. With the Cu atoms continuously diffusing into the Al liquid, layer I of γ is formed via a solid–solid transition with a certain content of Cu atoms, while layer III of α + θ is formed via eutectic transformation under the eutectic temperature. Making of Cu–Al intermetallic compounds, Layer I and layer II are the main areas of crack generation and expansion, thus, the thickness of the interface layer plays an important role that can control bonding strength. The temperature distribution of the composite Cu–Al plate during solidification is optimized by adjusting the parameters and controlling the formation of the composite layer. Therefore, a reasonable matching of the process parameters is the key to improving the microstructure of the composite layer and increasing the bond strength of the clad plate.
Abstract: With the development of offshore oil and gas fields, the oil–water two-phase mixing flow-transmission technology has been widely used in subsea pipelines. The high water cut and multiphase flow regime induce harsh and complex corrosion conditions; hence, mild steels combined with corrosion inhibitors are used in the construction of offshore pipelines for corrosion control. However, corrosion failure cases show that severe localized corrosion constantly occurs at the oil–water interface in oil–water mixed transmission pipelines, and the understanding of the mechanism and inhibition effect of corrosion inhibitors is limited. Moreover, laboratory studies on CO2 corrosion problems in oil–water mixed transmission pipelines usually consider only pure-water systems to simulate the corrosive environment. These studies seldom regard the effect of the oil phase on the corrosion process even though the actual production and transportation of fluids often involves multiphase mixed media. The oil phase is one of the important factors that affect corrosion behavior. Studies on the impact of the oil phase on the inhibition effect of corrosion inhibitor are still relatively lacking. Further studies on the inhibition effect of corrosion inhibitor in oily corrosive environments of oil–water mixed transmission pipelines are needed. In this study, the inhibition effect and mechanism of a corrosion inhibitor at the oil–water two-phase interface under flow conditions were investigated using the rotating cylindrical electrode (RCE) technique combined with electrochemical methods (electrochemical impedance spectroscopy and polarization curve analysis), laser scanning confocal microscopy, scanning electron microscopy, and UV-VIS spectrophotometry. The results reveal that 100 mg·L?1 of seventeen alkenyl amide ethyl imidazoline quaternary ammonium salt as a corrosion inhibitor in carbon steel for an aqueous phase of the oil–water two-phase stratified medium exhibits significant inhibition effect, and the corrosion inhibition efficiency reachs 99%. However, the effective mass fraction of the corrosion inhibitor decreases to 31% before mixing at the oil–water interface because of the presence of oil. As a result, the corrosion inhibition efficiency is only 83%, and the inhibition effect is poor; moreover, the corrosion of carbon steels cannot be effectively controlled. Further, significant groove corrosion is observed at the oil–water interface. Therefore, the corrosion of the sample in the oil area is slight, and the inhibitor can effectively inhibit the corrosion of X65 steel in the water area.
Abstract: In recent years, the automotive industry has become increasingly demanding for the strength of hollow structural parts. To meet the strength and toughness requirements, major automakers have begun to use high-strength steel for the production of automotive hollow structural parts, and the hydroforming process is the most economical way to achieve this purpose. However, studies on the hydroforming process of high-strength steel in the industry are few. To guide the production of high-strength steel hydroformed parts, the deformation behavior of DP590/DP780 high-strength steel welded tube during hydroforming was investigated in this study. The cross section of the circumferential direction of the tube was observed by scanning electron microscopy to determine the microstructure of the base metal. The sizes of the weld and the heat-affected zone of the tube were determined by VMHT30M microhardness tester to study the hydroforming fracture behavior. The deformation behavior of DP590/DP780 high-strength steel welded tube during hydroforming was studied by a tube hydroforming test machine. The experimental results are as follows: the fracture pressure of the tube during the bulging process is larger than the fracture pressure obtained by the theoretical calculation formula, and the rupture position is located in the base metal area near the weld and heat-affected zone. With the increase of the tube diameter and the length-to-diameter ratio, the maximum expansion ratio of the tube exhibits a downward trend. In the process of free bulging, the weld area of the tube is basically not thinned. The position of the minimum thickness is located in the heat-affected zone of the tube and the transition zone of the base body; the wall thickness reduction rate is the largest at the highest point of the bulging region, and the closer to the tube clamping zone, the smaller the wall thickness reduction rate. Finally, the following conclusions can be drawn: the hydroforming experiment of the tube can accurately obtain the mechanical properties of the tube. Improving the welding quality could help to control the failure rupture position. A reasonable selection of the length-to-diameter ratio of the tube is beneficial to the tube overall performance. It is beneficial to reduce the risk of cracking of the hydroformed part by reasonably controlling the thickness reduction rate of each part.
Abstract: In the process of tandem cold rolling of nonoriented silicon steel strip, it is imperative to design the control strategy and initial values of the edge drop control efficiency coefficient to achieve automated control in the edge drop by shifting tapered work roll. To obtain these values, intensive modeling is needed to study not only the effects of work roll deformation, metal transverse flow, and inter-stand deformation on tapered work roll shifting at one stand but also the effects of different work roll shifting values at the upstream stand on the edge drop at downstream stand. These intensive calculations have to be performed by an accurate numerical model with a high cost/effective ratio. Based on the metal transverse flow theory at the edge drop zone, a numerical model was built in this study, in which the lateral flow was treated as a pure shear increment inside the rolling region, so that building a stiffness matrix in the lateral direction was not needed and modeling cost was saved. Additionally, inter-stand deformation was considered. Considering the proportional ratio of the strip was broken by the tapered work roll shifting, the longitudinal strain at the strip edge was considerably lower than the strain at the center, which leaded to shrinking and thinning near the edge. It was proved that the coupled model can provide results, which were obtained through industrial experiments, with higher accuracy compared with the original one. Successive calculations of two stands were conducted to reveal the control effectiveness of different tapered work roll shifting values at upstream stand on the downstream stand. It has been observed that the edge drop control region is the widest at the 1st stand, and its width successively reduces at the 2nd and 3rd stands. Based on this rule, a control strategy based on a three-point measure instead of a single point was proposed, and it was proved to be more effective than the one-point measure used in industrial applications.
Abstract: The flapping-wing aerial vehicle (FWAV) is a new kind of aerial vehicle that imitates the flapping wings of birds or insects during flight and has the advantages of flexible flight, high flight efficiency, and good concealment compared with the fixed-wing and the rotary-wing aerial vehicles. Therefore, the FWAV has attracted considerable attention in recent years. However, the flight mechanism of the FWAV is complex and has many motion parameters with strong coupling. Thus, establishing a precise and practical motion model is difficult. At the same time, given the limited weight and load capacity of small FWAVs, it cannot carry accurate but heavy positioning equipment. Thus, many problems in autonomous flight control of FWAVs need to be addressed at this stage. For the fixed-height flight of FWAVs, an indoor fixed-height control system based on off-board monocular vision was designed. First, image sequences of the FWAV were obtained using the off-board monocular camera. Then, the ground station software based on Qt received the images, detected the light-emitting feature point on the FWAV, and obtained the pixel coordinates of the feature point on each image using the OpenCV image processing algorithms. On the basis of the Kalman filter, the image state estimator of the feature point was established to reduce the environmental interference and solve the temporal missing data problem of the feature point. Finally, the conventional and single-neuron PID control systems were established, where the motor speed of the FWAV was controlled by Bluetooth, to achieve image-based indoor fixed-height flight of the FWAV. Experimental results show that the fixed-height flight control system designed in this study can keep the image coordinates of the feature point of the FWAV at the center of the camera image. For the step signal, the response speed of the single-neuron PID control system is slightly slower than that of the conventional PID control system. However, the control accuracy of the single-neuron PID control system is better than that of the conventional PID controller, with a maximum relative error of 3%.
Monthly, started in 1955 Supervising institution：Ministry of Education Sponsoring Institution：University of Science and Technology Beijing Editorial office：Editorial Department of Chinese Journal of Engineering Publisher：Science Press Chairperson：Ren-shu Yang Editor-in-Chief：Ai-xiang Wu ISSN 2095-9389CN 2095-9389
