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Landscape garden design is an important design foundation course for undergraduate students of landscape architecture in China, but the current classroom teaching has the problem of limited spatial dimension of the course. This paper proposes a virtual scene model construction method through the computer software with the creation of the need to display the scene. This virtual reality technology has immersive, interactive, and risqué characteristics. This paper focuses on the key points of virtual reality technology, discusses the specific implementation method of virtual reality technology in the "landscape garden design" course, and introduces the interactive control principle. The results of the research show that virtual reality technology to assist teaching can cultivate students' spatial thinking and enhance students' spatial simulation experience, greatly reducing the cost of traditional teaching.

In this paper, we discuss the teaching effects of augmented reality (AR) technology in German instruction. We conducted one prestudy and three formal studies on German learners in China's mainland and Taiwan region. In the formal studies, a total of 120 students participated in the survey, allowing us to compare the differences in interest in learning between AR picture books and traditional picture books. A total of 114 students took part in the survey, which enabled us to compare the contribution of AR picture books to teaching when students' satisfaction and German proficiency were different. To improve satisfaction, 514 students participated in the survey regarding the influence of the interactive narrative design effect and peer learning on satisfaction with using AR picture books. The results suggest that when learning German with AR picture books, satisfaction is the key construct that determines students' learning states.

In response to the growing trend of internationalisation in education, it is important to consider approaches to help international students integrate in their new settings. One possible approach involves the use of e-Learning tools, such as virtual worlds and gamification. To maximise the potential effectiveness of such tools, it may be beneficial to involve international students in a technological codesign process. This paper develops an inclusive design process based on the definitions of Inclusive Design outlined by the SMARTlab and IDRC teams, as part of a co-design specification in practice, gathering specific information about the needs of Chinese students in Ireland at University College Dublin (UCD) through a questionnaire and an empathy-driven design approach. From the responses of questionnaire, we found that students would find beneficial many features that virtual environments can provide (e.g., 3D campus tours and virtual lectures). We also found that collaborative, social activities were a more popular way to potentially increase language and cultural understanding than structured courses. Finally, we learned that the incorporation of game-like elements in virtual environments requires careful planning: while this may be effective in increasing user engagement with information, users do not want to have to be successful in games in order to gain access to essential resources or information. Based on these specific needs provided by these Chinese students themselves, a virtual campus (VC) which was created in a unique virtual platform called Terf® has been constructed.

The increase of international exchange in education triggers strong demand for learning English language skills in various academic disciplines among Chinese students, which brings up a wide implementation of EAP (English for academic purposes) learning in universities in China. However, the teaching and learning result do not seem to be as satisfactory. A key factor to the disappointing situation is the lack of suitable textbooks. Currently, most of the few domestically designed EAP textbooks only focus on the reading and writing and cannot meet the learners' needs of overall (listening, speaking, reading and writing) development. The adoption of textbooks designed abroad was found unable to cater to the needs and language proficiency of the learners in China. There is an urgent need of constructing localized textbook for EAP learning in Chinese context. Previous frameworks on textbook design are mainly based on linguistic theories, which though offer theoretical support of language study from the perspective of learning subjects did not pay attention to the interconnection of factors within the learning environment. This paper proposes the application of eco-education theory to the design of a localized EAP textbook. It stresses the importance of the interrelations between textbook, editor, researcher, teacher and student during the process of designing a localized textbook so as to promote a healthy and sustainable development of EAP learning in Chinese context.

An improvement in cognitive performance through brain games play is implicit yet progressive. It is necessary to explore factors that potentially accelerate this improvement process. Like various other significant yet unexplored aspects, it is equally essential to establish a performative (fusion of accuracy and efficiency) insight about players' cognition (memory, vision, and analytics) among the different modes of brain games. This paper presents empirical research that investigates the impact of different modes of brain games (single vs. multiplayer) upon the players' cognitive performance. An accumulated result of the research revealed that the cognitive performance in memory stimulating and visual activity-oriented brain games play significantly boosts during multiplayer mode. Similarly, cognitive accuracy in analytical brain gameplay also increases during the multiplayer mode; however, it's rather inefficient. In addition, both the components of cognitive performance in single-player mode are reported as negatively correlated, while in the multiplayer mode it's rather contrary.

This paper outlines and describes the effectiveness of a virtual learning environment (VLE) as a grammar learning resource for first year students at a university in southern China over two academic years. The resource, named the Independent Grammar Study Scheme (IGSS), offered short grammar exercises that were completed over a 14-week period by two cohorts of year one students. The results of this study suggest that IGSS was successful in raising the grammar test scores of participants in both 2018 and 2019; that IGSS was more beneficial to students with lower English proficiency in 2018 but not in 2019; and that the VLE has been of great benefit to the university and to around one thousand students thus far.

The purpose of this research was to explore the relationships between design, learning, and translanguaging in a 3D collaborative virtual learning environment for adolescent learners of Chinese and English. We designed an open-ended space congruent with ecological and dialogical perspectives on second language acquisition. In such a space, sense-making is contingent on the relational dynamics of place, activities, and artefacts. These spaces encourage meaning-making in situ, manipulation of virtual objects within places, and coordination among players. Our investigation looked at how learners of Chinese and English collaborated on a project in which they decorated a virtual living room. The findings suggest that socioculturally bounded places afford unique learning opportunities. Firstly, learning occurred through "referencing", which is the mutual clarification of a virtual object's meaning, position, and function, in relatively stabilised places, such as a museum, and secondly, learning occurred through coordination between verbal instruction and object manipulation in more adaptive places, which we call eco-dialogical learning. We also found a strong relationship between translanguaging and object manipulation. We conclude the paper from the perspective of how the eco-dialogical model resulted in designs that promoted cognition and interactivity.

With the adjustment of energy structure, the utilization of hydrogen energy has been widely attended. China's carbon neutrality targets make it urgent to change traditional coal-fired power generation. The paper investigates the combustion of pulverized coal blended with hydrogen to reduce carbon emissions. In terms of calorific value, the pulverized coal combustion with hydrogen at 1%, 5%, and 10% blending ratios is investigated. The results show that there is a significant reduction in CO2 concentration after hydrogen blending. The CO2 concentration (mole fraction) decreased from 15.6% to 13.6% for the 10% hydrogen blending condition compared to the non-hydrogen blending condition. The rapid combustion of hydrogen produces large amounts of heat in a short period, which helps the ignition of pulverized coal. However, as the proportion of hydrogen blending increases, the production of large amounts of H2O gives an overall lower temperature. On the other hand, the temperature distribution is more uniform. The concentrations of O2 and CO in the upper part of the furnace increased. The current air distribution pattern cannot satisfy the adequate combustion of the fuel after hydrogen blending. [ABSTRACT FROM AUTHOR]

This paper describes the development of an aero control experiment apparatus (ACEA) for use in aerospace control practical courses. The ACEA incorporates a systematic multihierarchy learning and teaching method, and was designed to improve aerospace engineering students' understanding of unmanned aerial vehicle (UAV) control systems. It offers a number of standard experimental modules at three levels: component, system, and simulation and evaluation. The software and hardware design methods used in the modules were chosen to allow students to conduct experiments in a simple, more hands-on manner. As a result, they were able to select or reconfigure their experiments and so continuously improve their skills and extend the ACEA itself. The practical curriculum module-s-grouped in three skill levels of basic experiments, case study, and independent design--were applied in a 3-year M.Sc. course, UAV Control Systems. The marking criteria created to evaluate students' achievements are presented, along with some results of this evaluation.

This paper uses the finite-volume community ocean model (FVCOM) coupled with the simulating waves nearshore (SWAN) in a wave–current–sediment model to simulate the tidal current field, wave field, and suspended sediment concentration (SSC) field in the sea area near Weifang Port, China. The three-dimensional water-and-sediment model was modified by introducing a sediment-settling-velocity formula that considers the effect of gradation. Next, the SSCs calculated by the original and modified models were compared with the measured data. The SSCs calculated by the modified model were closer to the measured data, as evidenced by the smaller mean relative error and root-mean-square error. The results show that the modified coupled wave–current–sediment model can reasonably describe the hydrodynamic characteristics and sediment movement in the sea area near Weifang Port, and the nearshore SSCs calculated by the modified model were higher than those calculated by the original model. [ABSTRACT FROM AUTHOR]

The concept of geological engineering-integrated fracturing is widely applied in the conventional and unconventional reservoirs, aiming to achieve efficient and economic development. There is no doubt that fine reservoir evaluation is the basis and core of geological engineering-integrated fracturing. Therefore, in this paper, we performed a series of investigations on the basis of formation fine evaluation by using RoqScan technology. Firstly, the physical parameters of the target well located in Daniudi Gas Field were evaluated by a laboratory test and logging interpretation. Next, the composition and function of the RoqSCAN tool were introduce in detail. Furthermore, the elements, minerals, and rock mechanical parameters of the target well were evaluated by the RoqSCAN tool. Finally, the fine reservoir model was established on the basis of fine formation evaluation. Moreover, we conducted a series of research on porosity and principal stress of the target formation to compare the difference between the fine model and the conventional model. Based on the fine reservoir model, the acid-fracturing design and numerical simulation were further investigated. The results of experiments and numerical simulation mainly achieved the following findings: 1. The porosity and permeability of the target formation indicated that it was a tight, low-permeability reservoir; 2. According to the comparison of the distribution for different parameters in the target well, the modeling with fine reservoir evaluation had higher accuracy than the traditional modeling; 3. Based on the fine evaluation results, acid fracturing is recommended as a stimulation method to enhance the productivity of the target formation. This study provides an essential method for the integrated fracturing design of geological engineering. [ABSTRACT FROM AUTHOR]

Three Dimensional or 3D virtual reality has become increasingly popular in many areas, especially in building a digital campus. This paper introduces a virtual campus, which is based on a 3D model of The Tourism and Culture College of Yunnan University (TCYU). Production of the virtual campus was aided by Human Factor and Ergonomics (HF&E), an application which provided a convenient, comfortable, practical and simple environment for users. TCYU, in Lijiang, China, occupies approximately 800 acres. Set in a parkland environment, it is a modern campus with a rich architectural style based on local Naxi houses with gray tiles and white painted walls. Because it is very large for a virtual campus, the scale and complexity of models have been simplified. They have also been reduced for ease of loading the computer program by three means: Object-Oriented Modeling (OOM), textures and portal-connectors, and many easy-to-use tools have been created which support different input hardware and avatars to help the user tour the campus from different perspectives. Testing results show that the virtual system can run smoothly on the general personal computer.

High-altitude rockfalls, as one of the major geological disasters in mountains, is highly concerned about the study of failure mechanisms and disaster prevention and mitigation. In August 2020, the Babaoshan cliff in Yanhe County, Guizhou collapsed and falling rocks hit agricultural vehicles on the road and damaged residents' houses below. Based on on-site investigation, three rockfall types of tension-rotating, tension-shear-falling, compression-shear exist in the study area, and the compression-shear rockfall can conform to the chain law of rockfall. The paper used the dynamic analysis software Rocpro-3D to simulate and invert the movement characteristics and impact range of rockfall at Babaoshan cliff. The results show that: 1) the hazardous zone, which is about 95 m wide and 175 m long, was formed by the rockfall at R1 and covered localized roads and houses below, with the covered probability of 20%, 17% respectively; 2) the terrains on the rockfall paths in two rockfall disaster events are mainly characterized by stepped shape and overall flat angle respectively, and the behaviors are mainly characterized by ejection and rolling respectively, meanwhile, the times to reach the road and houses were 17 s and 24.3 s, respectively, in addition, the protruding rock mass below the rockfall location gives the falling rock horizontal velocity and good movement space, which will make the falling rock move further away; 3) the different rockfall directions reflect different terrain combinations, simulation inversions reveal that different terrain combinations have significant control over the distance and shape of the rockfall trajectories. And, it was found that the more times a falling rock is rebounded, the greater the energy obtained; 4) the probabilities of falling rocks at H1, H2, H3 invading residential areas are respectively 8.67%, 20%, 19.33%, meanwhile invading road zone are respectively 10.67%, 15.33%, 9.33%. At least one point or several points stopped within the zone of the affected houses in the rockfall disaster event 2 in three prediction of the rockfall impact range, which indicates that there is a great risk that this house will continue to be affected by disasters after rockfalls occur within the steep cliff area above. [ABSTRACT FROM AUTHOR]

This paper is based on the surface defects of casting billets in the production process of nonoriented silicon steel plates at a steel plant in North China. Taking the parameters of a slab mold in the nonoriented silicon steel production process as a prototype, the flow field characteristics of the mold under the same section, different drawing speed and immersion depth were systematically studied by using a LES (large eddy simulation) and VOF (volume of fluid) coupling algorithm. The results show that under the current conditions, when the critical slag entrapment speed increases from 1.0 m/min to 1.2 m/min, the nozzle insertion depth increases linearly with the critical slag entrapment speed, while when the nozzle insertion depth exceeds 130 mm, the increasing effect of further increasing the nozzle insertion depth on the critical slag entrapment speed begins to decrease. When the drawing speed of continuous casting is kept constant at 1.4 m/min, the abnormal fluctuation height of the steel slag interface is significantly improved when the angle of the water nozzle is increased from 15° to 20°, and the proportion of slag entrapment is also reduced from 0.376% to 0.015%. When the nozzle angle is 25°, the slag entrapment ratio is reduced to 0%, and the steel slag interface also ensures a certain activity. The numerical simulation results were applied to the industrial site, and the slag inclusion rate and crack rate of the billet in the continuous casting process of nonoriented silicon steel were obviously improved after the optimization process. [ABSTRACT FROM AUTHOR]

As underground engineering extends into the western and deeper regions of China, more and more Luohe Formation sandstone layers will be encountered, which have weak cementation and high water content. It is a significant challenge to apply the open TBM, and the support system is crucial in determining whether TBM can excavate quickly and safely. Therefore, in order to optimize the support scheme, this paper analyzes the pore structure and porosity through CT scanning, the results indicate that the volume percentage of pores ≥34 μm is 2.3% and 1.5%, respectively, the large pore apertures are predominant, the surrounding rock has strong permeability, and there is a high risk of rock burst and roof collapse accidents, hence requiring reinforced support measures. On this basis, numerical simulations were conducted to evaluate the support effectiveness. The results show that replacing the "bolt + mesh" with a "bolt + cable + mesh + steel belt", and replacing the top three bolts with 7.3 m anchor cables, can better control the deformation and provide sufficient thrust force for the TBM, ensuring excavation speed. After the implementation of this scheme at the Kekegai coal mine in Shaanxi, China, the TBM excavation speed increased by 70%, from the previous 10 m/day to 17 m/d, significantly reducing the project duration and construction costs. [ABSTRACT FROM AUTHOR]

Shale oil represents a relatively new form of unconventional oil and gas resource, and the extensive exploration and development of shale oil resources carry significant implications for China's oil and gas supply and demand dynamics. At present, within the realm of low-maturity shale oil extraction technologies, the reservoir must be subjected to elevated temperatures ranging between 400 to 60 °C. Prolonged exposure of wellbores to such high temperatures can result in a substantial decrease in cement strength, the formation of microcracks due to cement cracking, and damage stemming from thermal stresses on the casing. Casing damage stands out as a prominent factor contributing to wellbore integrity failures and well shutdowns within the context of shale oil development. Given the limited natural energy reservoirs of shale oil formations, it becomes necessary to supplement the reservoir's energy during the development process. Furthermore, shale oil exhibits high viscosity and poor flowability, and conventional water injection methods yield limited efficacy. This situation can induce significant shifts in the stress field and rock mechanical parameters, potentially activating specific formations and complicating the load dynamics on the casing. Consequently, the risk of failure increases. In light of these considerations, this study uses numerical simulations to study the integrity of high-temperature injection and production wellbores in shale oil and aims to encompass a comprehensive evaluation and analysis of the principal factors that influence casing damage, the fluctuations in thermal stress, and the yield strength of various steel grades of casings exposed to alternating stress conditions. Subsequently, this paper developed a model for simulating the temperature and pressure within shale oil and steam injection wellbores to support engineering design analysis. The research results indicate that the application of pre-stress results in a significant increase in stress at the casing pipe head while causing a noticeable decrease in stress within the pipe wall. When N80 casing is used, the entire casing experiences thermal stresses surpassing the casing's yield limit. Stress concentration may arise at both ends of the external seal, potentially leading to casing contraction, shear failure, and, under non-uniform stress conditions, casing bending deformation. The temperature of steam injection significantly influences the temperature field of the casing wall, with stress values experiencing a marked reduction when the steam injection temperature decreases from 350 °C to 200 °C, underscoring the substantial impact of temperature on casing thermal stress. As the steam injection process advances along with injection-production cycles, shear stresses at the interface can exceed the bond strength, resulting in relative slippage between the cement and the casing. The bonding force between the wellbore and the cement primarily depends on the interface's friction, particularly in the context of friction during wellhead lifting. This study endeavors to determine rational injection and production parameters under varying conditions, optimize completion methods, reduce casing damage, and extend the casing's operational life; it aims to offer critical technical support for the safe and efficient development of shale oil resources. [ABSTRACT FROM AUTHOR]

This paper reports on the effects an experimental English as a Foreign Language (EFL) program in Second Life (SL) had on Chinese student EFL learning. The study took an evaluative approach using quasi-experimental design with participants from one Chinese university and one American university in the southeastern United States. Results indicated significant main effects between a control group and the SL group on EFL measures, as well as significant gains in total score and several subcomponents between pre-test and post test. Further analysis using a post study survey, students' blog posting, and interview transcripts revealed that the SL_EFL Program had a positive impact on students' EFL learning.

Research into learning technology has developed a reputation for being driven by rhetoric about the revolutionary nature of new developments, for paying scant attention to theories that might be used to frame and inform research, and for producing shallow analyses that do little to inform the practice of education. Although there is theoretically-informed research in learning technology, this is in the minority, and has been actively marginalised by calls for applied design work. This limits opportunities to advance knowledge in the field. Using three examples, alternative ways to engage with theory are identified. The paper concludes by calling for greater engagement with theory, and the development of a scholarship of learning technology, in order to enrich practice within the field and demonstrate its relevance to other fields of work.

With the ongoing development and deployment of medium-low speed maglev vehicles in China, it has become common to increase operational speeds from 100 km/h up to 140 km/h or even 160 km/h, necessitating further studies and simulation models to understand the implications of these changes. This paper analyzes medium-speed maglev vehicle-track-girder coupling dynamic performance at a speed of 160 km/h. First, a field dynamics experiment is carried out on the Changsha Maglev Express with a running speed of 80–140 km/h. Then we introduce the distributed coupling simulation platform for maglev transportation system (MTS-DCSP) and the vehicle-track-girder coupling model, taking into account the complex vehicle structure, the guideway structure, and the Proportion Integral Differential (PID) levitation control system. Together, this platform and model can conduct a simulation of the complete process at scale and at all degrees of freedom to obtain accurate results. Our analysis of the results gives an accurate portrayal of the coupling dynamics properties and validates the coupling model. The results from the field experiments together with the coupling simulation demonstrate that the medium-speed maglev train can operate safely and stably within the range of 140–160 km/h. While at 140 km/h, however, the Sperling ride quality index (RQI) is about 2.5, which is within the Excellent grade range, at a speed of 160 km/h, the Sperling ride quality index can increase to as high as 2.74, which is a grade of Good. Therefore, it is necessary to optimize the parameters of the secondary suspension system to improve the ride comfort of the maglev vehicle at 160 km/h. [ABSTRACT FROM AUTHOR]

Summary: The proportion of groundwater‐related diseases in the operational high‐speed railway tunnels in China is increasing and rapid and accurate disease monitoring is urgently needed. Therefore, it is a new attempt to monitor 5‐ to 10‐m water‐bearing anomalies in operating tunnel structures by using train‐borne transient electromagnetic method. The stationary interference source train tracks in the tunnel environment have serious electromagnetic interference to the monitoring of water‐bearing anomalies. Thus, this paper combines numerical simulations and indoor experiments to carry out research on the minimum water‐bearing anomalies that can be monitored at such close distances by train‐borne transient electromagnetic method under electromagnetic interference from train tracks. First, a comparative study of the electromagnetic characteristics of the water‐bearing anomalies when their own parameters change is carried out by numerical simulation, followed by a comparative analysis of the electromagnetic response of the water‐bearing anomalies under the interference of train tracks. For the missing electromagnetic response of the coil‐metal‐anomaly in the numerical simulation, a full‐scale physical model experiment is conducted to obtain the time range of the three interferences. Also in the experiments, the feasibility of existing instruments for close range water‐bearing anomalies detection is verified by comparing different transient electromagnetic instruments. Finally, the minimum water‐bearing anomalies that can be monitored in close proximity under the interference of train tracks are obtained experimentally. [ABSTRACT FROM AUTHOR]

In recent years, the regulation of double-round monopoly for super platforms has rapidly become a key instrument of the anti-monopoly practice for Internet platforms in China. This paper aims to explore the evolutionary mechanism of double-round monopoly by using evolutionary game theory and constructing a four-party evolutionary game model that includes a super platform, an incumbent platform, a startup platform, and a government regulator, based on considering the micro-dynamic interactions between subjects and the main influencing factors of the evolutionary mechanism using numerical simulation. This study illustrates that the decisions made by each subject and its probability changes affect the evolution rate of double-round monopoly. Depending on the probability of double-round monopoly in the market, government regulators need to be flexible in switching between strict and less-strict regulation strategies to evolve the system to a more desirable, stable state. As well, we conclude that the regulatory strength of the government regulator, the cross-border magnitude of the super platform, the innovation incentive subsidy of the startup platform, and the synergistic risk cost of the incumbent platform have more significant effects on the evolutionary process of double-round monopoly. Therefore, it is suggested that government regulators should focus on the cross-border magnitude of super platforms to safeguard the rights and interests of incumbent platforms and startup platforms in order to allow for fair competition. At the same time, they should also adjust the regulation intensity by the evolution of double-round monopoly in the market, in order to realize real-time dynamic regulation with the mutual coordination of multiple entities. [ABSTRACT FROM AUTHOR]

In this paper, the finite-element (FE) method combined with smoothed particle hydrodynamic (SPH) method is used to simulate the bird strike process, and a new type of tail leading edge structure is designed. This kind of bird is represented by the SPH model, and the structure is simulated by traditional Lagrangian elements. The design for the novel structure can be described as incorporating a triangular reinforcement component into traditional tail leading edge structure. Numerical simulations of bird strikes with the novel structure indicate that the anti-bird-strike capacity of the new type of tail leading edge is greatly enhanced. Then, the corresponding bird strike tests are carried out to verify the numerical simulation model. The simulation results are in good agreement with the test results, indicating that the SPH-FE coupling method gives a useful tool for predicting the deformation and damage behavior of aircraft structure under bird impact, and for the design of bird-strike-resistant structure. Finally, through bird strike simulation and test of the horizontal tail leading edge with the new design of commercial aircraft, it can be observed that the front beam does not penetrate, which indicates that the new design meets the requirements of the China Civil Aviation Regulations (CCAR) Part 25 on the certification of the bird strike resistance of the wing leading edge. [ABSTRACT FROM AUTHOR]

A large number of drainage pipes and canals in China have been in disrepair for a long time and there have been problems such as leakage and corrosion. In response to these problems, this paper studies a non-excavation technology for repairing the arched canal structure—the in-situ spraying method. To study the influence of the original canal structure on the mechanical characteristics of the lining structure by in-situ spraying and the restraint effect on the lining structure, a field model test with a similar ratio of 1:2 was conducted in the field test pit. By conducting four stages of three-point concentrated load loading tests, the mechanical characteristics of the lining structure were investigated to reveal the influence of the canal structure on the force of the lining structure. The test results show that: the maximum crack width of the newly added lining structure is 0.27 mm and the normal service ultimate bearing capacity of the arched structure repaired by H-70 reaches 150 kN; comparing the loading test and the numerical simulation results, the difference between the two vault displacement results is 4.65% and the results are relatively consistent. The displacement of the bottom of the lining structure is small and the participation of the bottom plate is small, while the displacement of the upper arch structure of the lining is significantly larger than the lateral displacement, indicating that the canal structure can effectively limit the lateral displacement of the newly added lining and that the canal structure is greatly reduced. The bending moment of the lining structure is improved and the restraint effect on the arch foot is more obvious. This paper proposes the use of H-70 to repair arched canal structures by the in-situ spraying method and seeks to prove the feasibility of this method and fill the gap of research in this area. This paper provides the structural design basis and experimental knowledge for the construction of the repair method, which has important practical significance for the pipeline repair project in the future. [ABSTRACT FROM AUTHOR]

The pilot is the main person in charge of taxiing safety while moving on the airport surface. The visual separation and speed adjustment are directly related to safety and efficiency of airport surface operation. According to the actual taxiing procedures and airport control rules in China, this paper proposes a novel microscopic simulation model based on the pilots' visual separation. This model is also built by refining the aircraft taxiing procedures at intersections. The observation range, the separation judgment, pilots' visual distance, rate of proximity and the intention for speed governing are discussed as parameters in the model. The rules for aircraft separation judgment, pilots' autonomous speed governing, and position updates are also set up and discussed. The proposed simulation can accurately simulate the acceleration and deceleration intentions under different motion trends while reproducing the motion process including the following acceleration, following deceleration and delayed deceleration caused by separation changes. The results demonstrate that the number of conflicts can be reduced to 50% based on visual separation adjustment of 50 s when the convergence angle is 30°. The pilot's visual distance is inversely proportional to the fluctuation range of the speed of the rear aircraft, the proximity rate of the front and rear aircraft and the probability of conflict. The simulation results of this model conform to the actual taxiing routes and control rules, which provides technical support for improving the safety level of airport surface operation and presents certain reference value and practicability. [ABSTRACT FROM AUTHOR]

Loess landslides are a major geological disaster in the southeastern Qinghai Province, causing huge economic losses and casualties. The particularity of loess determines the disaster initiation mechanism, disaster mode, genetic mechanism, and complexity of the evolution process. This paper studies the deformation and stability analysis of the Quwajiasa large-scale multislip loess landslide in the Yellow River Basin from the perspective of field investigation, Interferometric Synthetic Aperture Radar (InSAR) monitoring, and numerical simulation. This study determines the deformation characteristics and genetic mechanism of the landslide through on-site field investigation, then quantitatively evaluates the overall deformation of the landslide using InSAR monitoring, locates the strong deformation area, and finally determines the control relationship between the two sliding surfaces on the landslide deformation using FLAC3D numerical simulation, obtaining the stability coefficient of the two sliding surfaces. The landslide is divided into seven engineering geological zones. The deformation history of the landslide is studied using InSAR technology. Results show that the landslide can be divided into significant deformation areas and no significant deformation areas. Two strong deformation areas are found. The FLAC3D numerical simulation results show that the deformation and stability of the right side of landslide are controlled by sliding surface 1, and the deformation and stability of the left side are controlled by sliding surface 2. The landslide is in an unstable state overall. The research done in this paper proposes a basis for the treatment of the Quwajiasa landslide. [ABSTRACT FROM AUTHOR]

This study aims to provide useful insights for the Chinese government in dealing with healthcare fraud by creating an evolutionary game model that involves hospitals, third-party entities, and the government based on the government reward and punishment mechanism. This paper analyzes the evolutionary stability of each participant's strategy choice, discusses the influence of each element on the tripartite strategy choice, and further analyzes the stability of the equilibrium point in the tripartite game system. The results show that (1) the government increasing fines on hospitals is conducive to compliant hospital operations, and the incentive mechanism has little effect on such operations; (2) the lack of an incentive mechanism for third parties results in false investigations by third parties; and (3) rewards from higher levels of government promote strict supervision by local governments, but that the high cost of supervision and rewards for hospitals inhibits the probability of strict supervision. Finally, Matlab 2020a is used for simulation analysis to provide a reference for the government to improve the supervision of healthcare fraud. [ABSTRACT FROM AUTHOR]

The application and economic efficiency evaluation mode of traditional composition in the field of modern music cannot meet the needs of various types of music in China, especially Guqin music. Based on this, this paper studies the big data simulation model of Guqin sound synthesis and plucking based on computer composition technology. The computer composition technology uses the discrete dynamic modeling technology of complex system to complete the computer simulation of Guqin sound through the analysis of the correlation between Guqin music data and realizes the storage and analysis of the generated Guqin sound data. In addition, the technology can analyze the data information of composition mode in the piano sound plucking simulation model with the classical Guqin music data stored in the cloud system over the years and then feed it back to relevant professionals for verification. The experimental results show that the Guqin sound simulation model can efficiently compare and analyze the melody and other data of classical Guqin sound with the simulated Guqin sound and can realize secondary data mining. This paper studies the application of computer composition method based on discrete dynamic modeling technology in Guqin sound simulation, which has certain reference significance for improving the cloud data in China's modern music field and the intelligent construction of Guqin sound data cloud storage system. [ABSTRACT FROM AUTHOR]

Ordovician limestone water on the floor is a serious threat to the safety of coal mine production in the Weibei coalfield, and prediction of the floor failure depth is the key for evaluating the mining conditions under pressure. This paper combines the hydrogeological conditions of the no. 5 coal seam and uses the FLAC3D program to determine the floor failure depth under two-factor (mining depth and width) and multifactor (mining depth, width, and height) conditions via numerical calculations and analysis. We obtain the fitting formula for the floor failure depth and analyze the influence of various factors on it. The results show that when the mining width does not exceed 200 m, the mining width has the greatest influence on the floor failure depth, followed by mining depth and mining height. In this paper, the working face floor failure depths measured values of 18 flat seams in China are taken as samples for comparison with the values calculated via empirical formulas and fitting formulas, and the maximum and minimum absolute errors and relative errors are analyzed. The nonlinear fitting regression formulas offered in this paper are found to provide strong predictive value, high accuracy, and a relatively small error range. The reliability and rationality of the models are further verified, thus providing a reference for future mining operations under safe aquifer water pressure conditions in the Weibei coalfield. [ABSTRACT FROM AUTHOR]

To explore the mixed traffic characteristics of vehicles and aircraft on the airport surface and solve the problem of real-time conflict detection at key intersections. According to the actual taxiing procedures and airport control rules in China, this paper focus on abstracting the mixed motion process of aircraft and vehicles in the maneuvering area, defining the convergent cross-safety operation scenario. To quantify the driver's attention to safety separation and the degree of conservatism in adjusting speed, the vehicle deceleration rate and acceleration rate are defined with α as the exponent. Under the same spacing, the vehicle deceleration rate is directly proportional to α, and α is named the vehicle safety sensitivity. At the same time, the rules of speed change of vehicles and aircraft will be designed, and a convergent operation model of aircraft and vehicles will be proposed. Based on real-time speed and separation dynamic assessment of safety and efficiency under different traffic strategies, the computer simulation results show that vehicle safety sensitivity and deceleration rules determine the sequence of vehicles and aircraft when they are passing through in the short term and can affect the proportion of mixed traffic flow in the long run. The safety probability of vehicles passing the intersection first is negatively correlated with vehicle safety sensitivity, while the safety probability of aircraft passing the intersection first is correlated positively with vehicle safety sensitivity. The efficiency of passing without conflict with mixed traffic has an inverse relationship with vehicle safety sensitivity. When the vehicle safety sensitivity takes the value in the interval [0.4, 0.6], a mixed traffic flow with higher safety and efficiency, better stability, and a balanced ratio of locomotives can be obtained. [ABSTRACT FROM AUTHOR]

Green, healthy and sustainable development is the development direction of China's agriculture, and stable fertilizer has become the first choice for orchard fertilizer. In this paper, in order to improve the working performance of the combined fertilizer application device of 2KF-30 type orchard stable fertilizer deep applicator, the matching degree of the combined operation of scraper and auger was taken as the research objective, and theoretical analysis, numerical simulation, and experimental verification were combined to carry out the research. Applying fuzzy theory, the comprehensive qualified rate weighted by the uniformity of fertilization and the qualified rate of fertilization was proposed as the evaluation index. The scraper shaft speed, scraper space, spiral conveyor speed, and spiral conveyor pitch were selected as the test factors, and the comprehensive qualified rate of fertilization for the combined fertilization device was taken as the evaluation index. The test design was carried out by single-factor and response surface method tests, and numerical simulations were conducted by discrete element software to analyze the optimal combination of fertilizer application parameters. The test results were analyzed based on the numerical simulation of discrete element software. The testbed was set up to verify the above optimal results. The results showed that the maximum error between the physical test and the numerical simulation was 8.67%, the minimum error was 1.75% and the overall mean error between the physical test value of the combined fertilizer application pass rate and the predicted value of the quadratic regression equation was 5.99%, which can meet the operational performance requirements of the fertilization device. The research results can provide a theoretical basis for the design and improvement of the deep fertilizing machine for orchard manure. [ABSTRACT FROM AUTHOR]

This paper analyzes the development prospects of zinc-nickel battery industry, further investigates the industry competition in existing markets by mathematical modeling, calculates the equilibrium price and profit of the oligarch competition by using the method of Stackelberg equilibrium and Nash equilibrium, and makes a comparison between them. Then, we study and model the case of renting and selling simultaneously. In addition, we also study the impact of futures prices on the zinc-nickel battery companies and carry out numerical simulation. At the end of this paper, we analyze the location of zinc-nickel battery enterprises and the industry development under the COVID-19 pandemic. The finding show that the reduction of raw material cost is of great help to the development of the zinc-nickel battery industry. [ABSTRACT FROM AUTHOR]

In China, MgO-based expansive agent (MEA) has been used for concrete shrinkage compensation and cracking control for over 40 years. The expansive behavior of MEA in cementitious materials could be manipulated to some extent by adjusting the calcination process of MEA and influenced by the restraint condition of the matrix. It is key to investigate the factors related to deformation and cracking resistance so that the desired performance of MEA in certain concrete structures could be achieved. This paper reviews the influence of key parameters such as hydration reactivity, dosage, and calcination conditions of MEA, the water-to-binder ratio, supplementary cementitious material, aggregates, and curing conditions on the deformation and cracking resistivity of cement paste, mortar, and concrete with an MEA addition. The numerical simulation methods and deformation prediction models are then summarized and analyzed for more reasonable estimations. [ABSTRACT FROM AUTHOR]

Hydraulic fracturing is a necessary measurement to realize the commercial exploitation of oil and gas, but its application in multilayered thin tight sandstone gas reservoirs is still not perfect, which usually have thin gas layers mixed with complex intervals, and shows a dramatic variation in geological and geomechanical properties in the vertical direction. When conventional hydraulic fracturing methods are applied to this kind of reservoir, it is hard to get proper fracture propagation, especially for fracture height control. Facing this situation, this paper proposes a numerical study of the hydraulic fracturing mechanism and analyzes its influencing factors in the multilayered thin tight sandstone gas reservoir. Relying on a real reservoir in the Ordos Basin in China, relevant geological and geomechanical parameters of major gas layers and interlayers are obtained. According to these parameters, the hydraulic fracturing simulation in the multilayered thin tight gas reservoir model is carried out, based on which, the sensitivity analysis of different geological and fracturing parameters which affect the fracture propagation is performed. Furthermore, a real low-production well after fracturing in this kind of reservoir is selected as an example, and based on the analysis, an optimized fracturing scheme is proposed to adapt to the characteristics of the reservoir. According to the comparison of fracturing and production simulations, the optimized fracturing scheme can prevent hydraulic fractures from breaking through thin interlayers, control the fracture height, and prevent fractures from communicating strata with a high water-bearing layer. At the same time, with the same amount of proppant and fracturing fluid, longer fracture length and better fracture conductivity are created, so that the productivity of the optimized fracture has been greatly improved. [ABSTRACT FROM AUTHOR]

In recent years, the state has put forward a grand plan to develop nuclear power in order to control environmental pollution and carbon emissions. In nuclear power plants, mechanical seals for reactor coolant pump play an important role in nuclear power safety production. However, China cannot independently produce such mechanical seals, and they are blocked by foreign related technologies, which has seriously affected China's nuclear power development plan and the overall safety of China's nuclear power operation. Under this background, this paper studies the friction performance of the shaft seal of the reactor coolant pump, uses the sensor to obtain the data of friction factors such as low-pressure leakage, effectively monitors the low-pressure leakage through calculation and simulation modeling, truly reflects the operating state of the reactor coolant pump, and provides a new research direction and experimental basis for further analysis of the friction performance of the shaft seal of the reactor coolant pump. The results show that under the joint action of the pressure difference and the force generated by the deformation of the moving ring plate, the cone angle formed on the seal end face is 1300.9 μ convergence gap of rad. When the inlet water temperature is 65°C, the leakage rate is 1867.8 L/h. The deformation of the moving ring deformation ring plate can hinder the increase of the deformation cone angle of the moving ring. The greater the thickness of the moving ring deformation ring plate, the greater the seal leakage rate. The inlet temperature of the sealing medium and the friction performance of the material also have an impact on the sealing performance. [ABSTRACT FROM AUTHOR]

The mountainous area of southwest China is characterized by significant topography and complex geological conditions, which pose great challenges to the airport's site selection, construction, and safe operation. Suining Anju Airport, one of the key projects under construction in southwest China, is essential in alleviating and dredging the air passenger flow in Sichuan Province. Because the overlying quaternary strata's physical and mechanical properties, thickness, and distribution range are fairly different in the longitudinal and transverse directions, the Anju Airport's foundation in the hilly area has typical inhomogeneity. Large-scale excavation and filling pose a challenge to the ground stability of the airport. To comprehensively monitor Anju Airport's uneven ground subsidence during the construction period, this paper selected SAR image data collected by the Sentinel-1A satellite from May 2018 to June 2021 to extract time-series ground subsidence measurements based on the SBAS-InSAR method. Furthermore, based on the simulation of roadbed filling in the airport's parallel slide fill area, the dynamic evolution analysis of soil stress field and internal subsidence caused by roadbed filling activities was carried out to further reveal the occurrence mechanism of ground subsidence. The monitoring results show that the subsidence centers of Anju Airport are mainly distributed in the filling areas, and the average annual subsidence is −20~−75 mm/yr from May 2018 to June 2021. Comparative analysis with in situ data indicates that the RMSE of InSAR monitoring results was ±6.12 mm. The numerical simulation shows that the subsidence of the airport parallel slide is mainly caused by a load of subgrade filling body and the compression of its weight. The results of this study can provide reference methodology and data support for the construction and future safe operation of Suining Anju Airport. [ABSTRACT FROM AUTHOR]