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To clarify the progress of application of different grouting materials in airport runway engineering, the commonly used grouting materials were introduced and different kinds of grouting materials were classified, the physical and chemical properties, reaction mechanism and their mechanical properties were analyzed, and their application scenarios in airport runway engineering were summarized. Comprehensive analysis of existing studies show that cement-based grouting materials and organic polymer materials are often used for foundation reinforcement and road surface disease treatment in airport projects. Organic polymer materials have advantages of short setting time and high strength, and single-liquid cement slurry materials are widely used and suitably priced, but their working performance is poor. Due to the reason of air service nonsuspend construction, the airport runway grouting project requires slurry with good fluidity, fast hard and early strength, high solidification body strength, and certain economy. The modification of single-liquid cement slurry by adding other materials can effectively improve its various properties, and it is now widely used in airport runway grouting projects. [ABSTRACT FROM AUTHOR]

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Modern circular agriculture aims to minimize the number of external outputs for less impact on the environment in the complex ecosystem and the circular economy of the industry chains. Therefore, the green development of agriculture can be achieved to promote rural revitalization in China. However, accurate data support and parameter matching are still lacking in most operation of circular agriculture. Fortunately, the life cycle assessment can serve as an effective tool to evaluate the environmental impact of the entire chains in the product systems, further improving the circulating efficiency of the systems in recent years. In this study, an empirical investigation using the life cycle assessment was performed on the modern “straw-sheep-cropland” agro-pastoral system located in the northeast of Suzhou, Jiangsu Province, China. Six types of potential environmental impacts were evaluated from the sufficient data collection and tracking survey using the data characterization, standardization, and weighted summation, including the acidification potential, global warming potential, terrestrial ecotoxicity, human toxicity, freshwater aquatic ecotoxicity, and eutrophication potential. And then the environmental service energy was compared for the emission degradation before and after the regulation. The energy was calculated to consume the pollution dilution for a safe concentration. The results showed that fertilization was an important factor in the environmental performance of the cereal cropping subsystem during the wheat- and rice-growing seasons. The types of potential environmental impacts from the feed producing and sheep raising subsystems were more than 85% of the total impacts, which were much higher than that of the cereal cropping and organic composting subsystems. The environmental impacts of human toxicity and freshwater aquatic ecotoxicity were greater in each subsystem, whereas, that of terrestrial ecotoxicity was the least. After life cycle assessment, the annual environmental service energies of air, water, and soil to realize the emission degradation were 7.42×1010, 6.03×1016, and 1.59×1012 J, respectively, according to the threshold concentration of index pollutants. Subsequently, the scales of feed producing and organic composting subsystems were adjusted in line with the matching output with the input of successive subsystems, particularly under the steady production scale of cereal cropping and sheep raising subsystems. A simulated regulation was also conducted to optimize the parameters and key technologies. It was estimated that the annual environmental service energies of air, water, and soil were reduced by 52%, 44%, and 21%, respectively, compared with the original. In conclusion, a new system was formed with excellent sustainability and replication to evaluate and regulate the modern agro-pastoral system using the life cycle assessment. The finding can provide a strong reference for the optimal regulation of modern agricultural systems in diverse regions. In the future research, the local life cycle inventory database can be constructed for the life cycle assessment. [ABSTRACT FROM AUTHOR]

In order to solve the issue of malicious phonily occupying seats for some ticket agents or passengers in the process of air ticket sales, this paper proposed a blockchain system scheme based on the improved PoA consensus mechanism. The scheme used the alliance blockchain as a communication platform among airlines, adopted credit points and dynamic grading to build a new PoA consensus mechanism, protected passengers ' private information with hash algorithm, and achieved digital storage of ID information, registration of passengers, storage and sharing of passenger booking information for airline corporations relying on smart contracts. The prototype system trial operation shows that the system can timely detect and effectively stop the phonily occupying seats behavior. After analysis and evaluation, the program has the characteristics of privacy protection, decentralization and high security, and provides a new reference to solve the long-standing problem of phonily occupying seats in the civil aviation field. [ABSTRACT FROM AUTHOR]

The construction of high- speed rail in China improves the comprehensive transportation systems significantly, while challenging the development of domestic air transportation at the same time. Based on the timetable data from 2007 to 2014, the overlapping market of HSR and air network is identified from the perspective of direct connection between city pairs. In 2007, the overlappping network only had 21 city pairs with direct flights and highspeed trains, and the number dramatically increased to 277 in 2014. This paper first analyzes the potential influence of HSR development on airlines and its spatial distribution. Then, a random effect regression model is established to measure the ex- post effects of the entry of HSR on air passenger flows of all the 277 city- pairs, among which, 94 city- pairs connected with the three hub cities, and 183 city-pairs connected with other feeder airports in China. The results are as follows: (1) Despite the fact that HSR and air transportation systems in China are developing in parallel, the entry of HSR has caused a modal shift from air transportation. The reduction on air travel demand caused by G trains is more obvious than that of D trains. (2) The air travel demand between inter-cities within the same or nearby provinces decreases sharply. (3) Distance, GDP, and rank of airports are significant positive factors in increasing air travel demand. (4) Due to various flight networks, preference for air transport, and sensitivity to travel time in hub cities, city pairs connected with Beijing, Shanghai or Guangzhou are more competitive for air transportation than for HSR. [ABSTRACT FROM AUTHOR]

Using the precipitation isotope data observed at nine stations in the middle reach of the Yellow River Basin, the spatial and temporal distribution characteristics and environmental effect of isotope in precipitation are analyzed, the trajectories of air mass transport in this area are simulated, and the changes of the water source area and the influence of conveying process on stable isotopes in precipitation in summer half year are studied by using OLR technology. The result shows: the content of δ18O precipitation has obvious seasonal variation that it is lower in spring and summer and higher in autumn and winter; the content of δ18O in precipitation increases from southeast to northwest; the meteoric water line shows obvious transitional features, and the precipitation effect is relatively significant; the water vapor source is transported mainly through the two channels: the northwest and southeast. The water vapor from east and the thermal and dynamic properties of the Tibetan Plateau have a great influence on the sources of water vapor in the basin. The change of water vapor source region and water vapor content field in the upper and middle troposphere have good relationship with the characteristics of stable isotope. In August and September, ITCZ formed in the western Pacific makes the southeast monsoon the main water vapor channel in summer in the middle reach of the Yellow River Basin. [ABSTRACT FROM AUTHOR]

During the flight phase of civil aircraft, the airborne surveillance system provides timely and accurate weather, terrain, traffic monitoring information and collision avoidance advisory to the pilot for safe flight. This paper firstly outlines the development process and current situation of airborne surveillance system and demonstrates the architecture of new generation Integrated Surveillance System(ISS) which complies to the ARINC 768 standard, then summarizes major functions and components of ISS, finally discusses and forecasts the development trend of airborne surveillance system. [ABSTRACT FROM AUTHOR]

Airworthiness is the key to the development of China's civil aircraft CNS (Communication, Navigation and Surveillance) system. This paper analyzes and determines airworthiness requirements and verification requirements of CNS system, and presents the verification method of CNS system according to airworthiness standards, that is performing verification by flowing the verification methods, verification levels, test bench and trace process. The method proposed in this paper can also be applied in other civil aircraft avionics systems. [ABSTRACT FROM AUTHOR]

This papaer introduces the civil aviation Very High Frequency(VHF) Aircraft Communication Addressing and Reporting System(ACARS) communication system and the air-ground communication management using the ACARSIP handling mechanism based on the civil aviation VHF ACARS communication system. The ACARS communication messages handling mechanism based on DSP and FPGA is used in the civil aviation VHF ACARS communication system, and the design and implementation of up-link signal processing, down-link signal processing, Carry Sense Multiple Access(CSMA) mechanism, channel quality detecting, subnet data statistics and audit pattern is described. Finally, the ACARS communication messages handling mechanism is analyzed and summarized, and its application future is pointed out. This scheme has been applied in chinas first civil aviation ACARS data-communication system, and a stable communication quality of 100% correct rate of receiving is achived as communicating with the international civil aviation radio. [ABSTRACT FROM AUTHOR]

The ground-air communication of civil aviation is interfered by radios, which has seriously endangered the normal flight of civil airplanes. This paper proposes an airplane dynamic tracking algorithm based on the study of the interference localization. Firstly, a novel signal model to accurately estimate parameters of the airplane is proposed. A method for instantaneous Doppler frequency estimation based on peak searching of the fractional ambiguity function (FAF) is proposed, and a method of projection approximation subspace tracking based on the fractional ambiguity function (FAF-PAST) is pro-posed to estimate the azimuth angle and elevation angle. Furthermore the velocity and location of the airplane are estimated by employing array geometry. As a result, the airplane tracking is achieved in bistatic radar, laying the foundations for interference localization. The correctness and effectiveness of the proposed method are verified with the computer simulation. [ABSTRACT FROM AUTHOR]

The airliner family is a set of airliners that uses a common sub-system or components while meeting different performance or operation requirements. The airliner family can share a larger market, which is one of the key strategies for success in business. Due to the shared demand, the optimization for conceptual design of airliner family is different from that of traditional conceptual airliner design. An effective optimization method is studied for conceptual design of the airliner family. A short/medium haul airliner family is used as an example for demonstration of the method. The configurations of the airliner family are presented. A global analysis code is modified to evaluate the conceptual design. The optimization formulation for the conceptual design is presented in detail, including design variables, design constraints, and objectives. A self-adaptive evolution algorithm is used to solve the optimization problem. The results after optimization indicate that the specific design requirements for each aircraft are satisfied, and design objectives (direct operating costs) are reasonably compromised for the airliner family. [ABSTRACT FROM AUTHOR]

Due to the difficulty in obtaining information in the conceptual design phase, this paper presents a route airliner price forecast method based on I-GM(0,N) model for vacant point forecast in characteristic sequence. After selecting price-affecting factors as well as setting the Benchmark Ranking Series based on Grey Relational Analysis, the listing prices of X aircraft, a currently developed route airliner in China, is forecasted by I-GM(0,N). Proved to have good forecast and simulation results in a case study of X aircraft price forecast and price simulation of some current route airliners, this method is practical in price forecast of route airliners in conceptual design phase. [ABSTRACT FROM AUTHOR]

Fire dynamics, heat transfer and finite element analysis method were used to obtain the fire resistance of airport terminal steel structure. First, the credible and most dangerous fire scenarios of airport terminal roof were adopt. Then, the fire dynamics software FDS and the heat transfer formula were used to get the temperature rise curves in the fire affected region. Finally, the model of the structure was set up by finite element method, the load conditions and temperature rise curves were combined to calculate the mechanical properties of the structure. The result shows that the internal force of some members in the structure are increased and even close to the design strength, but the vertical displacement of the structure is relatively small to the overall span of the structure, the structure is still in safe condition. From the perspective of overall security, it is efficient to carry out the fire-resistant design of structure by its own strength, and to improve the fire-resistant properties of the structure by strengthening the integrity and increasing the number of statically indeterminate. [ABSTRACT FROM AUTHOR]