bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on spatial variability of soil nutrient and the evaluation of soil quality based on GIS
Authors: Xiao Hai , Tan Chunhong
Published: April 2020

In this study, geostatistics and GIS were applied to analyze the spatial variability of soil nutrient and the soil quality combined with the research variability property and spatial data in research area. The purpose of this paper is to study the spatial variability regulations between soil quality conditions and soil nutrient. The results show that the spatial variability degree of organic matter (OM), total nitrogen (TN), available potassium (AK), available phosphorus (AP), alkaline nitrogen (AN) and pH is 42%, 33%, 31%, 67%, 58% and 13%. pH is weak variability, TN and AK is low variability, all OM, AP and AN are moderate variability. The spatial distribution of soil nutrient is different, but there are some relationships in partial area.
Correlation Analysis between the Control Degree of the Construction Project Department to the Labor Subcontracting Team and the Construction Quality
Authors: Daxiao XU , Dongming XU , Pengfei LI
Published: April 2020

As the labor subcontracting team is the most basic organizational unit on the construction site, which can have an impact on quality, safety, construction period and cost, the management of the labor subcontracting team by the construction project department is a very important part of the project management. The construction quality of construction engineering is also a hot issue studied by many scholars. From the existing research results, we can know that there are many factors that affect the construction quality. This paper sets up the concept of control degree, which indicates the comprehensive management level of the construction project department to the labor subcontracting team, establishes the control degree and construction quality evaluation system, and calculates the weight and comprehensive score of each evaluation index of the control degree and construction quality evaluation system by using entropy weight method. The correlation between control degree and construction quality is analyzed by using SPSS software, which provides reference for construction project management.
Investigation of the Effect of Fissure Angle and Temperature on the Strength and Deformation of Rock-like Material
Authors: Hongwei Wang , Qiang Ge , Lizhuang Cui , Yongyan Wang , Jianguang Li
Published: April 2020

In order to investigate the effect of fissure and temperature on deep-seated rock, uniaxial compression experiments were conducted on rock-like material with different fissure angle at different temperatures. We investigated the influence of fissure angle and temperature on strength and the influence of fissure on failure mode of the rock. Also, we simulated the uniaxial compression experiment of rock-like material with ABAQUS. The results of experiments and simulations confirmed that the strength of rock-like material decreased with increasing temperatures and the strength decreased first then increased with increased fissure angle. The crack initiation started from the tips of the pre-existing fissure and we could speculate via the simulation that the reason of the crack initiation was stress concentration on fissure tips.
Research on optimization design of underground garage comprehensive pipeline based on BIM technology
Authors: Li Pengfei , Yu Yingxia , Xu Daxiao
Published: April 2020

In order to explore the layout of the underground garage comprehensive pipeline and optimize the layout of the underground, this paper takes the complex large underground garage project as the research background, establishes a 3D visual information model by using BIM technology, and proposes the corresponding optimization principle and optimization process to optimize the design of the comprehensive pipeline in the complex area of the underground garage. On the premise of satisfying the use function of the pipeline and the internal height of the underground garage, it also takes into account the beauty and other requirements. The application of the optimized model in this study to guide construction fully meets the acceptance requirements, reflects the superiority of BIM technology, and has good practical guidance significance.
Research on construction technology of frame structure in construction engineering
Authors: Wu Wei
Published: April 2020

With the rapid development of the construction industry, the building technology needs to be improved day by day. The application of reinforced concrete frame structure is suitable for all kinds of projects for its strong seismic capacity, good integrity and durability. This paper introduces the characteristics of the frame structure, discusses the problems existing in the two important works of reinforcement and formwork, and introduces the correct construction technology. Finally, it expounds the construction method of the frame structure of the construction engineering, and the affectivity was demonstrated in concrete frame structure cases.
Design towards the conversion between land sports and ice sports in infield space of arena
Authors: Qiao Lin , Liu Deming
Published: April 2020

In order to speed up the realization of the development goal of “300 million people participate in winter sports“, winter sports facilities have been built all over the country. The construction of arena combined with ice sports is also one of the measures to increase ice sports facilities. The article compares the arena combined with ice sports to the common arena, and analyzes its advantages. In view of the special characteristics of ice and land sports, the article summarizes the main factors that need to be coordinated in design and technical aspects of ice sports arenas from the aspects of site, athlete’s room, equipment room, site structure and thermal environment, and comes up with design strategies.
Key Technologies of Metro Construction in Complex Geological Areas
Authors: Hongbo Li , Gelin Liu
Published: April 2020

In recent years, China's underground rail transit has developed rapidly, especially with the construction of urban subway tunnels, submarine traffic lanes, water conservancy and hydropower, and municipal public tunnels. The construction of underground tunnels by shield method has been widely used. However, in some complex geology, the construction of the shield method still encounters many problems, including ultra-shallow covering and connecting through the group houses. How to solve these practical engineering problems is a topic that people are very concerned about. Based on this, this paper has carried out related research work on three common problems, including the ultra-shallow soil-pressure-balanced shield lake bottom tunnelling technology, the shield tunnelling control technology for the close-crossing group buildings, and the construction technology of complex geological and extra-large subway stations. Through the review of existing cases and theoretical research, it provides references for similar construction problems in the future.
Airport Passenger Throughput Forecast Based on PSO-SVR Model
Authors: Li Yuanxun , Jiang Xiushan
Published: April 2020

Accurate prediction of airport passenger throughput can provide a scientific basis for airport construction, aircraft procurement, and route planning. Based on the characteristics of airport passenger throughput, the support vector regression machine prediction model based on particle swarm optimization (PSO-SVR) is proposed. First, the conditional attributes and decision attributes are selected in the historical data of airport passenger throughput. Secondly, the particle swarm optimization algorithm is embedded to optimize the kernel function parameters and penalty factors. Finally, the support vector regression machine is used to predict the airport passenger throughput in the next year. Beijing Capital, Shanghai Pudong, Guangzhou Baiyun and Chengdu Shuangliu were selected as examples to verify the validity of the model. And compared with the moving average method, exponential smoothing method, ARIMA precision. The results show that the PSO-SVR model improves the prediction accuracy, and the average absolute percentage errors for the four airport throughput forecasts are 3.21%, 4.37%, 2.38, and 4.43%, respectively.
Analysis of Causes of Bank Collapse in Jiangxinzhou Section of the Lower Reaches of the Yangtze River
Authors: Cheng Xiaobing , Li Wangsheng
Published: April 2020

The Jiangxinzhou section is located in the Wuhu-Nanjing section of the lower reaches of the Yangtze River. It is the throat section connecting the downstream 12.5m deepwater channel and the middle reaches of the Yangtze River “645 Project” project. In the river section, the first phase of the channel improvement of the river section from Jiangxinzhou to Wujiang was implemented from 2009 to 2010. Since the implementation of the project, the left bank of Pengxingzhou to Jiangxinzhou in the river section has repeatedly collapsed during the construction period and after the handover. The effects of the revetment project and the overall problems are adverse. This paper analyzes the external environment and internal factors of the 11 collapses on the left edge of Jiangxinzhou from Pengxingzhou from 2009 to 2015. It summarizes the characteristic parameters of several bank collapses and studies the types of bank collapse. The mode of its collapse was explored. Combined with the research results of collapse type and collapse mode, the principles and key points of bank protection are proposed.
Study on flow characteristics of rough undulating single fracture based on CFD
Authors: Liang Shu
Published: April 2020

The cubic law is the basic law to describe the seepage in the cracks of parallel plates. However it can not be directly used to describe rough undulating fracture. By using the method of computational fluid dynamics, the law of water flow in rough undulating fractures with different roughness, fracture width, hydraulic gradient and fracture length is studied. The cubic law is modified and the mathematical formula of equivalent fracture width is established.
Impact of Efficient Logistics and E-WOM regarding Online Purchase Intentions of University Students in Karachi
Authors: Asghar Shayaan , Mahmud Bahri
Published: April 2020

The study aimed to determine relationship among trustworthiness, reverse logistics, relevance, quality, timeliness and customers purchase intention. The online outline had been scattered to 15 universities in Pakistan with electronic long range informal communication framework and email. The study samples were Pakistanis who were general online purchasers. The selected respondents were online buyers who usually did shopping online in Pakistan. The respondents were from different universities from Karachi which included students from various faculties. Information was used factual procedures of variable investigation, relapse and connection. The factual system was used SPSS programme. The descriptive analysis was used to analyse statistical research. Meanwhile, total of 200 different questionnaires were presented to target population. The result showed reverse logistics, trustworthiness and timeliness had significant influenced on buyer purchase intension. Besides, quality and relevance had no significant with buyers purchase intention. The substantial investment is needed by policy makers to ensure that reverse logistics is developed in an effective manner.
Optimization of Air Logistics Transport Network of YTO Express
Authors: Tong Zeping , Meng Fanyue
Published: April 2020

In order to improve the overall level and long-term development of YTO Express, according to the development strategy and planning of YTO Express logistics, this paper puts forward the construction of Hub-and-Spoke air logistics transport network with core hub airport, and optimizes YTO Express transport network. Firstly, the cluster analysis function of SPSS is used to divide the region of the air node, and then the center of gravity method is used to select the regional hub point, and the core hub airport and the regional hub airport are determined, so as to design the final transport network, which is conducive to the sustainable development of YTO Express, and improve the proportion of YTO Express in the air field.
3D Numerical Simulation of the Influence of Drilling-blasting Subway Construction on Subgrade Settlement
Authors: Yu Yongyan , Wang Jiliang , Du Tianling , Liu Ying
Published: April 2020

Based on the tunnel between Junfeng road-Xiliuzhuang of Qingdao metro, the tunnel excavation model is established by FLAC3D software. The established calculation model mainly includes:(1) Free field boundary conditions are adopted around and at the bottom of the model;(2) The blasting load is simulated by triangle pulse wave;(3) According to the peak value V of the surface velocity, the peak value Pmax
of the velocity in the triangular pulse wave is calculated by Sadovsky formula;(4) The calculation results show that the vertical settlement of subgrade is more significant when compared with horizontal settlement;(5) the calculation results are in good agreement with the field monitoring data. It shows that the method can simulate the dynamic characteristics of the model and reflect the dynamic response of subgrade settlement.
Study on the evolution of dynamic performance of high-speed EMU after long-term service
Authors: Wang Qi , Cui Tao , Shi Junjie , Sang Hutang
Published: April 2020

In order to find the influence of wheel and rail wear about dynamic performance of the high-speed railway vehicle in the actual operation process, a high dimensional strong nonlinear dynamic model of the high-speed vehicle is established, and measured wheel profile is used to characterize contact geometry between wheel and rail, and relationship between stiffness of steering rubber joint and dynamic performance of railway vehicle is studied in different wheel/rail wear state. Results show, With the increment of wheel and rail wear and equivalent conicity, that stability of hunting motion of vehicle decreases, stability and safety of the vehicle all deteriorate. Moreover, with the increment of longitudinal steering joint stiffness, critical speed, lateral stability and safety of vehicles increases gradually. When it goes above 17.5MN/m, with the increments of critical speed, lateral stability and safety tend to be stable. With the increment of lateral steering joint stiffness, critical speed of vehicle tends to increase first and then decrease, and finally tends to be stable around 5MN/m, which reaches the maximum when the stiffness is 2.5MN/m. Lateral stiffness of steering joint has little influence on lateral stability of the vehicle; At low equivalent conicity, vehicle running safety decreases slightly with the increment of lateral stiffness of steering joint, while equivalent conicity increases, the vehicle running safety deteriorates sharply with the increase of lateral stiffness of steering joint. In conclusion, in order to adapt to different equivalent conicity, the optional range of longitudinal stiffness of steering joint is suggested to concentrated in 5∼17.5MN/m, while its lateral stiffness is suggested to be within 2∼5MN/m.
Economic Development Advantages of Low-Carbon Economy under Waterway Transportation
Authors: Jing Mei , Zheng Weigang
Published: April 2020

With the continuous deepening of economic development, ecological hidden hazards such as environmental pollution are gradually emerging. Global warming, over-exploitation of energy, land desertification, and other problems are emerging. It is urgent to grasp the direction of national environmental protection policy support, and take the advantages and disadvantages of low-carbon economy development as the primary merit index for industry development.

Firstly, this paper expounds the internal relationship between water transport and low-carbon economy. Then it objectively examines and analyzes the difficulties and reasons of the development of waterway transportation economy in low-carbon economy. Next, it is pointed out that the water transport system under the background of low-carbon economy is an inevitable choice. Finally, the paper summarizes the advantages of the economic development of waterway transportation, and puts forward the corresponding optimization countermeasures according to the actual situation, which provides an effective guarantee for deepening the low-carbon behavior of transportation.
Pricing and Advance Ordering Strategy for Prefabricated Building Assembler
Authors: Jiang Wen , Shi Kanfeng
Published: April 2020

This paper studies an advance order strategy for prefabricated building assembler. We study how advance strategy affect assembler’s profit, and assembler how to choose strategy to meet consumer demand. In contrast to much of the literature, we introduce time sensitivity of consumer into the demand function, and divide prefabricated components into standard and nonstandard components to highlight the characteristics of prefabricated building. Furthermore, we present two different order strategies. In one strategy, assembler orders all components once costumers’ order arrives in one time, consumer have longer waiting time. In another strategy, assembler orders standard components in advance and orders nonstandard components until consumers’ order arrives. Our results show that assembler can make decision in different situations to achieve optimal profit, and satisfy consumer demand.
Analysis of precipitation time characteristics in key water demand period of main crops in Western Guanzhong
Authors: Qu Tong , Xia Cong , Huang Lingmei
Published: April 2020

Based on the daily precipitation data of seven meteorological stations in the western part of Guanzhong area from 1970 to 2016, the time characteristics of precipitation series are analysed by using the methods of sliding t-test, wavelet analysis and R/S. The results showed that the annual precipitation, summer maize and winter wheat precipitation in the key water demand period generally showed no significant downward trend, and there is no significant mutation point. It will maintain the change characteristics consistent with the recent historical period in the future, which provides certain reference for the regional water resources planning and reasonable allocation, agricultural planting structure adjustment, and irrigation system improvement.
Spatial-temporal Variations in Lakes in Central Yunnan Province from 1987 to 2017
Authors: Lv Jie , Yuan Xiping , Gan Shu
Published: April 2020

Lake spatial-temporal variations are sensitive records of climate and environmental changes, directly reflecting global changes. Lakes have great ecological and economic benefits, which play an important role in improving the ecological environment of the river basin, regulating surface and underground runoff, irrigating farmland, breeding aquatic animals and plants, maintaining biodiversity, flood control and disaster reduction, and producing and drinking water. In this paper, we took lakes in central Yunnan province as the research object, based on Landsat TM, ETM+ and OLI remote sensing images data in the period from 1987 to 2017, the vectorized boundary of 5 lakes with areas greater than 30 km2 in central Yunnan were obtained by artificial visual interpretation technology and the causes of lake variations were analysed. Several conclusions can be drawn from the present study: (1) From 1987 to 2017, the total lake area in central Yunnan increased from 603.86km2 to 605.71km2.(2) During the study period, the lake area in central Yunnan increased as a whole, but also showed obvious spatial differences. According to the change of lake area, the study area can be divided into three types: stable, expanding and shrinking. Dian chi lake area is a lake area expanding area. Yang zonghai lake area is a shrinking lake area. (3) Influenced by the complex natural and cultural environment in the study area, the reasons for the change of lake area in different areas are different.
Risk Assessment of Marine Hydrodynamics for Coastal Engineering
Authors: Gao Feng , Wang Yue , Zhao Xu , Xu Ya-nan , Tan Zhong-hua
Published: April 2020

Risk assessment in marine hydrodynamics is an important part of ocean disaster and risk analysis. Its key scope lies in the identification of hydrodynamic risk factors and the forecast of their severity which is one of the most effective approaches to improve disaster protection capability, control risk and reduce damage and loss during a disaster. Haikou Bay is located off the north coast of Hainan Island, within Qiongzhou Strait, and close to the South China Sea.The most significant marine hydrodynamic disasters in the waters of Haikou Bay include storm surge, extreme waves and tsunami. The Holland wind and Monte Carlo method were integrated to predict storm surge elevation, and the SWAN model with the Pearson method was used to calculate the extreme waves and using USGS source parameters to predict tsunami waves. High water surface elevations are 3.75m, 3.02m and 2.68 with a return period of 500, 100 and 50 year respectively at Xiuying; an extreme water surge up to 4.42m from the Probable Maximum Storm Surge analysis; significant wave heights present with different return periods and wave directions; the maximum tsunami wave amplitude reaches 2.25m in case of all fault plates under a 9.0 earthquake.
Optimal Pricing and Assembly Rate for Prefabricated Construction Assembler with Subsidy Policy
Authors: Jiang Wen , Qi Xian
Published: April 2020

With the development of the construction industry, assembly construction has received an increasing number of attention. The government introduced subsidy policy to promote prefabricated construction. We have considered subsidy into the traditional prefabricated construction, in which case decision on retail pricing and construction assembly rate will be complicated. We discussed the impact of subsidy policy on assembler pricing and assembly rate. The paper finds that subsidy policy can lower the retail price of prefabricated construction and increase the assembly rate, the assembler must control the cost factor for increasing assembly rate within a certain range to obtain higher profit.
Fuzzy evaluation method of pipeline passing through dike based on Uncertain Analytic Hierarchy Process
Authors: Ma Ying , chen Xiaozhen
Published: April 2020

In view of the characteristics of many factors influencing the safety risk of the pipeline through the embankment, which are hierarchical and uncertain, this paper combines the uncertain analytic hierarchy process (AHP) and fuzzy operation to establish a fuzzy comprehensive evaluation model. The uncertainty analytic hierarchy process (AHP) was used to determine the weight of the evaluation indicators, considering the uncertainty of the relative importance of the evaluation indicators at the same level, the credibility of experts and the degree of difference. According to the principle of maximum membership degree, the evaluation grade of the pipeline is determined. Finally, the feasibility of this method is verified by combining with specific engineering examples to reduce the potential loss and provide the safety management of the pipeline.
Analysis of spatial-temporal differentiation and influence factors of construction land expansion of the urban agglomeration in central Yunnan
Authors: Lin Yilin , Zhao Junsan , Zhang Meng , Chen Guoping
Published: April 2020

This paper takes the plateau mountain city: the urban agglomeration in central Yunnan as the research area, 2000-2015 as the research period, and measure and analyze the spatio-temporal differentiation of construction land expansion in the urban agglomeration based on the calculation of kernel density. Use the spatial autocorrelation model to analyze the spatial autocorrelation patterns of construction land on the 1 km × 1 km grid scale, and then use the GIS spatial analysis technique to study the local aggregation area at the p<0.05 significance level of the construction land in relation to natural and social driving factors. The result shows that the growth and distribution of urban construction land in this urban agglomeration is affected by natural social factors and land policies, and the area of construction land is growing rapidly. The areas with large distribution density of construction land at four time points are mainly located in flat dam area in the central and eastern part of the urban agglomeration, and mountain in the northern part. The spatial distribution of construction land in this urban agglomeration from 2000 to 2015 is mainly represented by two patterns: high-high aggregation and low-low aggregation. The topographical features dominated by plateau mountains affect the local spatial clustering of the construction land. At 4 time points, the elevation is 1000∼3000 m, the slope is between 2°-25° and the sunny slope area is the area with the largest distribution and the most concentrated area of the construction area. The farther away from the water system and the road, the local space gathering area of construction land is decreasing.
Applicability Analysis of Drought Index in Shandong Province
Authors: Shen ZhenTao , Zhao Qiang , Yao Tian
Published: April 2020

The frequent occurrence of drought disasters restricts the agricultural development of Shandong Province. To analyze the drought situation in Shandong Province reasonably, the selection of drought index is particularly important. In this paper, the standardized precipitation index SPI, precipitation Z index and precipitation anomaly Pa of each city in the dry years of Shandong Province were calculated, and the drought of Shandong Province was analyzed by ArcGIS software. The applicability of the three drought indices in Shandong Province was compared. The results show that: in November 2010, the SPI index was better reflected in the drought, the Z index did not show the mega-arid area, and the Pa index exaggerated the drought in some cities; in March 2011, the Z-index showed that most cities were Light drought, SPI index reflects better than the Pa index for drought; in August 2014, Pa index monitoring showed that more than half of the cities were light drought, Z index showed that most cities were moderately dry, and the SPI index monitoring results were similar to the actual drought conditions; In October 2015, the Z index showed that more than half of the cities had no drought. The monitoring results of the Pa index for some cities were opposite to the actual ones. The monitoring results of the SPI index were consistent with the actual drought conditions.
Spatial pattern analysis of Higher Geographical Education in China
Authors: Qiang Zhao , Qian Gao , Pengyu Ran
Published: April 2020

In order to analyze the spatial pattern of higher education in geography science in China, the data of geographic science colleges and universities and the total population and GDP of each region were established in 2007, 2011 and 2016, based on ArcGIS 10.3 spatial analysis and formulas such as extreme value ratio, discrete coefficient, geographic concentration index and related analysis methods. The research shows that the gap in the scale of inter-provincial development of geography science majors in China is gradually increasing, but the distribution imbalance of institutions is gradually decreasing. The spatial pattern is formed by the combination of topography, population, economy, and policy. There are still some problems today. Finally, the countermeasures and suggestions for promoting the rational development of the spatial pattern of higher education in geography science are put forward.
Mountain flooding analysis based on SCS-CN model – A case study in Mingxi, China
Authors: He Xinyue , Chen Chao , Liu Yue
Published: April 2020

Flood and waterlogging disaster occurs frequently, which seriously threatens people’s life and properties. The SCS-CN model takes into account the characteristics of various factors such as rainfall, soil type, land use, soil moisture and surface runoff. In this paper, the SCS-CN model is introduced to the analysis of flood inundation in mountain areas. Firstly, remote sensing data, land use status map, topographic map are used to obtain land-use type, slope and other data. Then, watershed analysis is carried out based on SCS-CN model to obtain runoff data. Finally, based on rainfall data, the inundated area is estimated, and the spatial and temporal distribution characteristics of inundation area were analyzed from the perspective of land use. The experimental results of Mingxi county in Fujian province, China show that this method is effective for the analysis of flood inundation in mountainous areas.
Study on the Spatial-temporal Differentiation and Driving Mechanism of Ecological Vulnerability in Zhangye City
Authors: Jun Luo , Xuebin Zhang , Hongmei Ding
Published: April 2020

Based on the “Sensitivity-Pressure-Resilience” evaluation model, combined with the spatial principal component (SPA) analysis method of GIS, we evaluated the ecological vulnerability of Zhangye City in 2000, 2005 and 2010, then we used geographical detector model to analyse the main driving factors of the ecological vulnerability. The results showed that: 1. The ecological vulnerability of Zhangye City was higher in the West and lower in the East. The average value of ecological vulnerability index was 0.45, which was mild fragile, ecological vulnerability index was the highest in Linze county, and the lowest in Minle county. 2. The overall ecological vulnerability showed a trend of improvement from 2000 to 2010, due to the increase of precipitation in 2005, the ecological vulnerability index was higher than that of 2000 and 2010. 3. Geographical detector results showed that six factors could explain the ecological vulnerability, which ranked as: rainfall in flood season (0.1138) > temperature in high temperature season (0.1116) > elevation (0.0581) > vegetation coverage (0.0532) > topographic relief (0.0411) > biological abundance index (0.0384), and the interaction of the 6 factors had a stronger explanatory power to the ecological vulnerability.
Printing temperature effects on the structural and mechanical performances of 3D printed Poly-(phenylene sulfide) material
Authors: Magri A El , Vaudreuil S , Mabrouk K El , Touhami M Ebn
Published: April 2020

Fused Deposition Modeling (FDM) is the most popular and widely used additive manufacturing techniques for plastic materials. In FDM, the Z-height of the object is achieved by depositing extruded polymer layer upon layer. To reduce the time and cost of printed parts requiring specific properties, many processing parameters can be adjusted to optimize the FDM process. Among those is the nozzle temperature. In this study, Poly-(phenylene sulfide) (PPS) was chosen because of its mechanical performance, making it attractive for high-performance applications. In this work, the impact of printing temperature on the mechanical and structural properties of printed parts was carefully tested. Results show that a 340°C printing temperature yield the parts with the highest tensile properties, with a degree of crystallinity superior to as-received PPS.
Dosimetric investigation for the new BEBIG cobalt 60 source used in brachytherapy using Monte Carlo N-Particles eXtended code (MCNPX)
Authors: Elboukhari S , Yamni K , Ouabi H , Bouassa T , Mlouk L A
Published: April 2020

The purpose of this work is to calculate the parameters of the 60Co-source model: Co0.A86 newly introduced to the HDR brachytherapy, and to validate the MCNPX code in Monte Carlo investigation, the radial dose function, and function of anisotropy are calculated in water as recommended in the report of HEBD working group (AAPM&ESTRO). The results obtained in this study agree will with the data published in previous studies.
Design of high-performance perovskite solar cells adapted to the tandem configuration
Authors: Laalioui Saida , Alaoui Kawtar Belrhiti , Assali Kassem El , Ikken Badr , Outzourhit Abdelkader
Published: April 2020

Thin film based solar cells offer the added advantage of presenting a low temperature coefficient of power and are usually suggested for hot climates. Perovskite solar cells have reached today a record efficiency of 25.2%. In addition, they demonstrated a great compatibility to be used as the top cell in tandem cells, either with CIGS, CZTS, perovskite or silicon heterojunction (HIT) as the bottom cell. The purpose of this work is to design and analyse the selected planar perovskite solar cells (PSCs) reaching high power conversion efficiency and stability with layers configuration of glass substrate/FTO/TiO2/MAPbI(3-x)Clx/CuSCN/Au, using the SCAPS-1D software. The thickness of MAPbI(3-x)Clx and FTO was varied from 0.4 μm to 1.4 μm and from 0.02 μm to 0.5 μm respectively and the best results are observed at 1.1 μm of perovskite absorber and 0.05 FTO μm. The best performances of this device architecture, calculated with SCAPS software are cell efficiency of 27.79% with an open circuit of 1.2 V, a short circuit current of 26.04 mA/cm2 and a fill factor of 88.85%.
Noncovalent functionalization of carbon nanotubes by polyaniline molecules: Raman analysis
Authors: Chenouf Jamal , Boutahir Mourad , Fakrach Brahim , Rahmani Abdelhai , Chadli Hassane , Rahmani Abdelali
Published: April 2020

Polyaniline/single-walled carbon nanotube composite (PANI4@SWCNT) has been studied theoretically by means of Raman spectroscopy calculations. We evidence that the structural organization of the nanohybrid systems depends on the diameter of carbon nanotubes. To study the stability of PANI4 molecules encapsulated in the cavity of the SWCNTs, the optimum configurations of PANI4 inside carbon nanotubes are derived from minimum energy calculations using a convenient Lennard-Jones expression. We discussed also two important Raman features of SWCNTs before and after encapsulation of PANI4 including the G-band and the radial breathing mode (RBM) taking into account its metallic or semiconducting character. The G-band shift suggests a significant charge transfer between the PANI4 and the nanotubes.
Enhancement of localized surface plasmon resonances of silver nanoparticles array upon the presence of graphene coatings: LSPR biosensor
Authors: Barghouti Mohamed El , Akjouj Abdellatif , Mir Abdellah
Published: April 2020

We study, in this article, the resonance of localized surface plasmon (LSPR) on silver nanoparticles (AgNPs) deposited on a glass substrate and coated with a graphene. The resonance peaks in the absorption spectra of the nanostructure SiOx/AgNPs/Graphene, show significantly different profiles such as the thickness of the graphene, and the refractive index of the surrounding environment which is, gradually, varied. Numerical simulation reveals that movements in plasmon resonance peaks result from coupling between the AgNPs networks and the covering graphene layer. In addition, the LSPR modes shift to red from 412 nm to 548 nm when the thickness of the graphene layer deposited on silver nanoparticles changes from 0.34 nm to 9 nm. Light coupled with LSPR modes propagating along a AgNPs-graphene interface is calculated and compared to a conventional AgNPs-based LSPR biosensor. The result of the comparison depicts an improvement in the sensitivity of the biosensor from 26 to 106 nm/RIU.
Effects of refractory nitride reinforcements on the microstructure, densification and microhardness of Ti6Al4V-based binary composites produced by spark plasma sintering
Authors: Abe J O , Popoola A P I , Popoola O M , Ajenifuja E
Published: April 2020

The effects of different refractory nitrides: aluminium nitride (AlN), titanium nitride (TiN) and hexagonal boron nitride (h-BN) reinforcements on the microstructure, densification and microhardness characteristics of spark plasma sintered Ti6Al4V-based binary composites were studied. The microstructure was examined by optical microscopy, densification was evaluated according to the method of Archimedes and the microhardness of the sintered composites was measured by Vickers microhardness tester. The SPS technique was successfully used to consolidate Ti6Al4V powder and 3 wt.% nanoparticles of AlN, TiN and h-BN respectively. The binary composites produced attained nearly full theoretical densification (98.22 to 99.54%) due to enough diffusional mass transport ensuing in solidly bonded compact of the matrix and the refractory nitride reinforcements. Ti6Al4V-3h-BN composite gave the optimal combination of relative densification and microhardness values of 99.54% and 7.03 GPa which exceeds 200% that of the monolithic alloy and about 48% superior to both composites with TiN and AlN reinforcements.
Study on application of adhesives for Carbon Fiber Composites connection in High-speed Rail
Authors: Yan Jiangyi , Deng Qian
Published: April 2020

At present, the high-speed train mainly made up of carbon fiber composites adopts a new flame-retardant multi-material system. It is necessary to select adhesives for the Adhesive bonding structures of different materials in order to meet the overall technical and performance requirements of high-speed trains. Through this research, mechanical performance data of several structural adhesives and sealant adhesives are obtained when they are bonded to the high-speed trains with carbon fiber composite material as the main body. Finally, the optimum adhesives for bonding different material systems in the high-speed trains are determined under different operational aging environments, which also provides data support for the formulation of connection specifications for carbon fiber reinforced composites in the field of high-speed railway. In addition, a multi-dimensional data reduction method is proposed for the analysis of sealant performance data, which is very helpful for the future analysis of big data of adhesives.
Life prediction of multi-pit-crack interaction in pressure vessel
Authors: Zijie Zou , Zhongbao Qin , Qi Liu
Published: April 2020

During the service of pressure vessel, there are many kinds of structural damage. The main defect is pitting caused by corrosion of loaded materials, cracks are formed because of stress concentration in the pit position, and crack propagation leads to crack leakage. As an important parameter to characterize cracks, fatigue life is widely used in engineering to judge the safety and reliability of mechanical structures. In this paper, based on the two-parameter pit-crack model, the fatigue life of pressure vessel with multiple pits-cracks is discussed by using ANSYS finite element analysis software. The results show that the fatigue life of pressure vessels decreases with the existence of multiple pits and cracks, but with the increase of pit-crack spacing, the effect decreases gradually until it returns to a stable state. The effect of pit parameters and the ratio of crack length to depth on fatigue life has obvious interval effect. This paper can be used as a reference for failure assessment of multi-pit-crack pressure vessels.
Development of Decision Support System for Solving the Machine Selection Problem in an Intermittent Manufacturing System Design
Authors: Buathong P , Vilasdaechanont A
Published: April 2020

Capacity planning, which is integral to resource selection and allocation, is an important task in manufacturing system design. As budget is limited, investment in resources must be done carefully and appropriately in order to achieve desired capacity and system efficiency. One of the most expensive and valuable resources in the manufacturing system is machinery. Therefore, selecting an appropriate machine is of high significance. Among many types of manufacturing systems, intermittent manufacturing system is complex, yet flexible. The intermittent manufacturing system enables manufacturers to produce multiple products using multiple processes and multiple machines. The system comprises a network of multiple types of multi-process machines. A machine selection problem in the context of the intermittent manufacturing system is a delicate process, as it must correspond appropriately with production complexities. To alleviate this problem, we develop a decision support system for solving the machine selection problem in an intermittent manufacturing system design. We study several manufacturing systems producing multiple types of products with various multi-process machines to lay out the framework. This decision support system consists of four main parts, namely; data entry, data conversion, optimization model and report. To solve the machine selection problem, an optimization technique is used to identify the optimal number of machines and the allocation of production process of each machine. The objective of this optimization problem is to minimize total production costs (machine cost and operating cost) while maintaining production capacity and other production constraints. The decision support system is developed for and validated with the manufacturing company.
Adaptive sliding mode control of electro-hydraulic servo system based on RBF network
Authors: Zhou S H , Wang H , Li J , Lan L Y
Published: April 2020

In order to solve the steady-state error in position tracking control for electro-hydraulic servo universal testing machine, caused by uncertain parameters in the system model, an adaptive sliding mode control strategy based on RBF neural network is proposed for this situation. This paper utilizes the adaptive ability of RBF neural network to improve the control quality of the electro-hydraulic position servo system. The strategy has three parts: the equivalent control, the reaching law control and the compensation control based on RBF network. Simulations verify that the control system can track the reference curve well with unknown parameters.
Researches on suppliers selection based on improved AHP-TOPSIS method
Authors: Wang Xinchen , Ma Yanhua , Gao Pengfei , Zhai Lu , Gu Bing
Published: April 2020

Selection of supplier can be considered as the significant strategic decision for company’s competitive advantage. Generally, the scales of criteria for selection were used to evaluate the performance of suppliers. But the traditional criteria are limited to reflect the comprehensive ability of the suppliers. Meanwhile, the quantitative scale, which is used to evaluate the suppliers, is too subjective to describe the real station of suppliers. Therefore, the improved analytic hierarchy process (AHP) is conducted to reanalyze the criteria and distribute the weight for each criterion. Technical for order preference by similarity to ideal solution (TOPSIS) used to calculate the relative proximity for each supplier and rank them based on the corresponding information. Finally, the calculate process is programmed by Excel VBA and MATLAB respectively. The two results show the same ranking order, which verify the improved AHP-TOPSIS method can effectively guide company to select supplier.
User requirement and usability testing framework for information system development: case study of financial institution
Authors: Thatawong P O , Jiamsanguanwong A
Published: April 2020

Due to the fact that financial institution has its limited competency in developing the information system, outsourcing is often used to support the information system development which same as the case study of the issuing documents system in financial institute. The financial institution has received customer’s complaints regarding the mistake of issuing documents caused by the system functionality and human error in operations. Thus, the purpose of this study is to design framework of user requirement and usability testing for information system development to prevent the error in system functionality and set some quality checking process of documents before delivery to customer to prevent mistakes from human error in work operation. System Usability Scale showed that after proposed the framework of user requirement and usability testing to employees who related with the system development, their level of satisfaction toward the framework and non-framework of user requirement and usability testing raise up to 30.93% and 20%, respectively. After six months of implemented quality checking process of documents revealed zero complaints from customers regarding to the mistake of issuing documents.
Research on welding deformation of side beam of freight train bogie
Authors: Liyana  , Suliang  , Wangwen
Published: April 2020

The welding deformation directly affects the production quality and service life of the bogie, so controlling welding deformation is an important engineering problem in the production process of the bogie. In this paper, the side beam of freight train bogie is taken as the research object, the heat source of the local joint mode is checked based on the thermal elastic-plastic theory and the plastic strains are extracted to establish the inherent strain database with the welding simulation software.Then, the welding deformation of the whole side beam is carried out by using the inherent strain method based on thermal elastic-plastic theory. By quantitative analysis of the displacement deformation, the results show that simulation numerical results are similar to factory experimental data. At the same time the rationality and reliability of the established inherent strain database are verified. It is also proved that the inherent strain method based on thermal elastic-plastic theory is a fast and effective way to predict the welding deformation, which provides technical support for the prediction and control of the welding deformation of the whole frame of the fast freight train.
Research on Vehicle Exterior Fire Suppression Techniques
Authors: Deng Gaoshou , Lin Runing , Shi Xiaoxiang , Zhang Wen , Chen Hui
Published: April 2020

This paper studies automatic vehicle exterior fire detection and suppression techniques. The main difficulties include: 1) complex and changeable environment outside the vehicle; 2) low sensitivity of the fire detector; 3) quick dissipation of fire extinguishing agent in the open space outside the vehicle; 4) extinguishing agent nozzle blocking due to dust and sand. This paper selects a special ultra-fine dry powder fire extinguishing agent for automobiles to design the protective nozzle and to study the automatic detection controller with the functions of condition monitoring and fault diagnosis, with an aim to improve fire suppression reliability. Based on the virtual and real vehicle tests, it is verified that the fire extinguishing effect of the designed system meets the design requirements.
Design path of hybrid bean planting machine based on human-machine symbiosis aesthetics theory
Authors: Zhao Aili , Guo Zhanbin , Wang Liming , Qu Qingfeng , Qin Haibin
Published: April 2020

Based on the theoretical study on the creative design theory of hybrid bean planting machinery, and combined with the aesthetic characteristics of hybrid bean planting machinery modeling of perceptual engineering-promoted symbiosis mechanism, an innovative design path based on man-machine symbiosis aesthetics of hybrid bean planting machinery was constructed to realize the innovative design style of hybrid bean planting machinery under the background of intelligent age, and thus improving the design level of agricultural machinery finishing.
Structural analysis of performance optimization of high g accelerometer chip
Authors: Chen Jiajun , Li Haojie
Published: April 2020

Accelerometers based on micro-electromechanical systems (MEMS) technology are widely used due to their high cost performance and easy integration. However, there are still weaknesses in the mutual limitation of sensitivity and natural frequency in ordinary MEMS acceleration-sensitive structures. In this paper, a new type of piezoresistive acceleration-sensitive structure is optimized. The specific parameters are optimized by finite element simulation. Finally, the natural frequency of the sensitive unit reaches 2.039MHz and the sensitivity reaches 0.546μV / g.