bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the distribution characteristics of “Characteristic Ring” in irregular cross-section ventilation roadway
Authors: Ding Cui
Published: August 2020

In order to study the airflow distribution in irregular cross-section roadway, the numerical simulation method were carried out to simulate the influence of hemispheres with radius of 100mm, 200mm, 300mm, and 400mm placed in different positions in the roadway on the distribution of “characteristic rings”. The results showed that concave body is not the key factor influencing the distribution of “characteristic ring” in ventilation roadway. Convex body is the key factor influencing the distribution of “characteristic ring”, the greater the ventilation velocity, the smaller the velocity gradient in the stable zone and the velocities in the stable area are more closely to the average velocity. As the increase of ventilation velocity, the velocity gradient is larger in transition zone. The size and position of the convex and concave bodies are not the key factors influencing the velocity distribution on the central axis of cross-section.
Spatial-Temporal Pattern of Novel Coronavirus Pneumonia (COVID-19) in Europe
Authors: Wang Wei
Published: August 2020

Fighting the Novel Coronavirus Pneumonia (COVID-19) is an urgent task and major concern in the world. As the core of public health events, Epidemiology is most concerned with spatial-temporal pattern. Based on the statistical data, this paper discusses the impact range and spread trend of the epidemic in Europe. The significance and suggestions for multi-scale assessment of the epidemic severity are put forward.
Industry Analysis of Recycling Application of Organic Waste Pyrolysis Co-production
Authors: Wen Enlong , Yang Wang , Xian Chunmei , Jian Liu , Fang Zhen , Huang Kun , Hu Chuntao
Published: August 2020

Pyrolysis technology is a new development direction in recent years, through the specific analysis of the technology in the industry, to guide the development of technology and enterprise investment. According to the application of the technology in the industry, the application of technology, market size, national industrial policy, industry barriers and market competition are analyzed comprehensively. The results show that the first, organic waste pyrolysis technology has a high operating cost and has no obvious advantages in market competition compared with incineration. The second, technology is not mature enough, poor reliability and stability. Third, the lack of relevant industrial policies on pyrolysis technology has an adverse impact on the promotion and application of technology. Fourthly, as a new environmental protection and green treatment method, pyrolysis is being paid more and more attention by relevant departments and enterprises.
Efficient Decomposition of Perfluorinated Compounds In a High Photon Flux UV/sulfite system
Authors: Gu Yurong , Dong Zijun , Chen Haijie , Li Yongbing
Published: August 2020

Perfluorinated compounds (PFCs) have attracted increasing attention due to their global distribution, high chemical stability and persistence. Hydrated electron (eaq
-) is a strong reductant, and is reported promising for recalcitrant organic pollutants decomposition. In this study, eaq
- based photodecompositon of several PFCs in a high photon flux UV/sulfite system was investigated. Perfluorosulfonic acids (PFSAs) and perfluorocarboxylic acids (PFCAs) decomposition in the studied system were 1∼2 orders of magnitude faster than that in previously studied BDD electrooxidation and UV/KI photoreduction systems. Kinetic study revealed the observed rate constant (Kobs) of both PFSAs and PFCAs increased with the increase of carbon chain length. In mixed PFCAs or PFSAs solution, decomposition of each PFCAs or PFSAs was suppressed due to the competition of eaq
-.
Numerical investigation of porous surface parameters on the performance of micro-channel reactor for hydrogen production by methanol steam reforming
Authors: Feng Yanbing , Li Xingzhan , Zheng Yueqing , Cui Hailong
Published: August 2020

To enhance the energy conversion of a micro-channel reactor with a porous surface for hydrogen production, the effects of structural parameters of the porous surface (surface area ratio, ratio of depth-diameter and distribution of pores) on the comprehensive performance of the reactor are numerically investigated. The CFD model is established to simulate the process of hydrogen production in the micro-channel reactor with a porous surface. Then, a series of numerical simulations with different structural parameters of porous surface are carried out. The distribution fields of flow rate, temperature, pressure and gas concentration can be obtained through the numerical analysis. Results indicate that with the increase of surface area ratio, the methanol conversion and hydrogen production rate is greatly improved, while the ratio of depth-diameter and distribution of pores have little effect on the performance. When the reaction temperature is 290 °C, the methanol conversion rate of the micro-channel reactor with a porous surface can reach above 90%.
Cadmium phytoremediation potential of Gnaphalium affine D. Don and physiological response in metal tolerance
Authors: Li Qiqian , Liu Xuhui , Qin Yongrong
Published: August 2020

In this study, the plant growth, physiological responses and phytoremediation potential of the herbaceous plant Gnaphalium affine D. Don were evaluated in varying extents of Cd contaminated soil and 40 days cultivation. The results demonstrated that the plant had a high Cd tolerance of up to 300 mg.kg-1 in which Cd content in roots and shoots reached a maximum of 733.9 and 404.6 mg.kg-1 respectively. Cd exposure enhances the malondialdehyde (MDA) level and antioxidative response (SOD, POD and CAT) in shoots of Gnaphalium affine D. Don. The bioconcentration factor (BCF) values in all treatments were greater than 1 and the translocation factor (TF) values were almost 2 at the high Cd concentration treatments. These findings indicated that Gnaphalium affine D. Don as a Cd-accumulator can be considered as a potential candidate for phytoremediation in Cd polluted sites.
Numerical calculation and analysis of parameters of collapsible loess treatment on composite foundation based on FLAC3D
Authors: Min Youwei
Published: August 2020

Combined composite foundation technology is one of the research directions for dealing with collapsible loess foundation in the northwest region. Under the vertical load of rigid-flexible composite foundation reinforcement, considering the relevant factors of rigid pile, flexible pile, cushion, etc., a FLAC3D finite element model was established for numerical analysis. The results of the research show that the length of rigid piles is the main factor affecting bearing capacity and settlement, and the main function of flexible pile lengths is to improve the strength of shallow soils and eliminate the collapsibility of loess. This paper provides a reference basis for the study of the combined composite foundation mechanism.
Construction of Fixed Bed Reactor and Catalytic Performance of the PS-ILs Enabled by Immobilized Ionic Liquids for Esterification
Authors: Zhang Jun , Wang Yanfang , Zhao Zhiping
Published: August 2020

Polystyrene (PS) microspheres, prepared by suspension polymerization, were applied to synthesize chloromethylated polystyrene microspheres (PS-CH2Cl) by chloromethylation. PS-CH2Cl was then used for the immobilization of acidic ionic liquid to prepare immobilized ionic liquid polystyrene microspheres (PS-ILs) as catalyst, thus avoiding the difficulty of ionic liquid separation. The structure of PS-ILs was characterized by SEM and FT-IR. PS-ILs was loaded in a fixed-bed reactor to catalyze the esterification of acetic acid and n-butanol. The experimental results indicated that the catalyst had good catalytic performance. The conversion rate of acetic acid was about 81.58% after 4 h reaction in the fixed-bed reactor.
Study on the Local Stability of Unidirectional Buckling Members of a New Type of Section Steel
Authors: Haiqiang Dai
Published: August 2020

The paper investigates the unidirectional buckling performance of lipped thin-walled U-shaped steel using numerical simulation with the finite strip program CUFSM. The local stability of the steel under compression at the opening side is studied. 33 different members are selected, each with a length of 2.5 m. All the members are divided into four series, and each series is used to investigate the influence of one parameter: the ratio of web height-to-upper flange width, the ratio of lipped height-to-upper flange width, the ratio of lower flange width-to-web height and the thickness of the plate. The laws of buckling stress, buckling mode and half-wave length of the member are analyzed. Finally, this paper gives a reasonable value range for these four parameters, according to which a reasonable cross section can be designed in the actual project, so that it can meet the needs of the actual project and has a certain economic index.
Heat Transfer Simulation of Large Caliber Gun Barrel
Authors: zhen Wang , jin Wei
Published: August 2020

During the continuous firing of artillery, the inner wall of the barrel will experience a continuous rise of temperature, which has much to do with the ambient temperature and the way it cools. For artillery using combustible cartridge, the temperature rise of the barrel’s interior wall will have a great impact on the safety of combustible cartridge during successive shots. The finite element model of gun barrel was established by ANSYS software while the convection heat transfer in the inner and outer walls of the barrel and the heat transfer in the barrel wall were simulated. This paper observed the temperature variation of the inner and outer wall of the barrel under different ambient temperatures and different cooling methods, revealing that the higher the ambient temperature, the faster the barrel temperature rises. Different cooling methods have little influence on the inner wall temperature, which would emerge long after shooting. The research provided theoretical basis for the safe use of combustible cartridge cases.
Study on the influence of barriers in the diffusion process of liquid hydrogen leakage
Authors: Wang Yawen , Chen Yanwei , Zhao Huiping , Xiong Yanyi
Published: August 2020

Based on the computational fluid dynamics method, a numerical model of large-scale liquid hydrogen leakage and diffusion is established. By simulating the diffusion process of hydrogen cloud when the obstacle is located at different positions, we get the motion law of cloud and the important time parameters of Cloud Diffusion reaching the dangerous range (combustible concentration). Compared with the process of liquid hydrogen leakage and diffusion under barrier-free conditions, it was found that setting an obstacle in the wind direction of the leakage port can accelerate the diffusion speed of the hydrogen cloud. The time to reduce the cloud concentration below the flammable range is reduced by 15%, therefor, can decrease the risk of fire; however, setting barrier in the downwind direction will lead to the accumulation of hydrogen cloud near the ground, and the time when the cloud concentration drops below the flammable range is 64% longer than the barrier-free working conditions, the possibility of serious secondary accidents was increased.
Comparison of Physiological and Biochemical Characteristics of Grafting ‘Lingfengnuo’ and ‘Guan litchi’
Authors: Shi Meng-Jiao , Wu San-Lin , Li Jing-Bai , Yin Juan , Liu Fang
Published: August 2020

In this experiment, the optimal grafting combination was obtained by comparing the physiological and biochemical characteristics of the rootstock ‘Dahongpao’ with scion ‘Lingfengnuo’ and ‘Guan litchi’. The results showed that the soluble protein content and the enzyme activity of POD in the rootstock-scion combination of ‘Dahongpao’ and ‘Lingfengnuo’ were higher than those of ‘Dahongpao’ and ‘Guan litchi’, with higher affinity and better adaptability to the environmental and climatic conditions in Leshan area.
Releasing control of nitrogen and phosphorus from contaminated sediment covered with aluminum-zirconium modified zeolite
Authors: Shunli Ning , Siyuan Hong , Shilong Shen , Hui Qiu , Chun-lei Zhang
Published: August 2020

In this paper, aluminum and zirconium based metal compounds were used to modify natural zeolite to produce Al-Zr modified zeolite (AZMZ). The adsorption performance, micro morphology and releasing control effect of AZMZ on nitrogen and phosphorus from sediment were tested. Test results show that the adsorption performance of natural zeolites on ammonia nitrogen and phosphate in water was significantly improved after Al-Zr modification. The adsorption model is chemical adsorption, and follows the quasi second-order kinetic equation and Langmuir model. The saturated adsorption capacity of 0.5 to 1.0 mm size of AZMZ for ammonia nitrogen and phosphate in water is 8.40 mg/g and 3.10 mg/g respectively. AZMZ has the potential to be used as in-situ covering materials to control the release of nitrogen and phosphorus from sediment. The average release rate was resduced by the increasing thickness of AZMZ. When the covering thickness of AZMZ reaches 0.5 cm, the releasing rate of nitrogen and phosphorus in the sediment can be effectively controlled. When the AZMZ thickness reaches 1.0 cm, the releasing reduction rate of nitrogen and phosphorus in the sediment are 89.1% and 75.3% respectively.
The study of influencing factors to straw mixed with livestock manure anaerobic fermentation
Authors: Peng Lei , Liu Shengyong , Chu Yajun , Jie Libin , Pan Yibo
Published: August 2020

Anaerobic fermentation of mixed raw materials is an effective method to solve the single raw material fermentation instability and adjust the carbon to nitrogen ratio during the fermentation process. In this study, manure and straw were used as mixed fermentation raw materials. The effects of mixed raw material types, total solid concentration, inoculum types and inoculation ratio on gas production efficiency were studied. The experimental results show that the total TS has the greatest effect on the biogas gas production effect. The pig manure and rice stalks are used as the mixed raw materials. The total TS is set to 10%. The inoculum is selected from the biogas slurry. The inoculation ratio is 30%. The gas rate is 0. 61 L/(L . d). The influence of four factors on gas production performance is: total solid concentration> fermentation raw material> types of inoculum> inoculation ratio. The test results have certain reference significance for anaerobic digestion of mixed raw materials.
Evaluation of bearing capacity of reinforced stone arch bridge based on static load test
Authors: Hu Chuanwen , Luo Wenbo , Chen Shunchao
Published: August 2020

In order to evaluate the stress and working performance of a reinforced stone arch bridge, the load test of the bridge is carried out. Static load test is to test the stress and displacement of each section of the main arch ring under the action of partial load and medium load. The results show that under the action of various loads, the check coefficients of deflection and strain of this bridge do not exceed the specification limit of 1.0 of masonry arch bridge, the actual working performance of the structure is good, the maximum value of relative residual strain and relative residual deformation are 11.11% and 8.21% respectively, and they do not exceed the standard allowable value of 20%, and the whole bridge is in the elastic deformation stage. The test results show that the reinforcement method of thickening the main arch ring has good application value, can effectively improve the service level of the old bridge and prolong the safety service life, and has obvious social and economic benefits.
RHBr/RGO composite material as an enhanced sensing platform can detect Cu2+ with high selectivity
Authors: Sun Peng , Xu Kaibing , Guang Shanyi , Xu Hongyao
Published: August 2020

This work reports a simple and efficient electrochemical detection method, using RHBr / RGO nanocomposite electrode material modified GCE to detect trace Cu2+. A simple and effective assembly method is used to prepare RHBr/RGO composite materials. After characterization by DPV and EIS, we discussed and optimized some factors that affect the detection of chemical sensors. Then DPV was used to evaluate the analytical performance of RHBr/RGO/GCE in the detection of Cu2+. Using optimal experimental factors, the linear response range of the sensor to Cu2+ concentration is 4×10−7∼1×10−5 M, and the detection limit is 3.9 nM (S/N = 3).
Properties of biochar from wood and textile
Authors: Han Tianhao
Published: August 2020

Due to population growth and economic activities, the increasing of generation and unreasonable disposal of waste biomass have been payed more attention than before. Traditional disposal methods may lead to environmental issues such as contaminating water and soil. This study explores the possibility of utilizing waste biomass to prepare biochar which can be used as addition in cementitious composites. This presents an obvious opportunity to recycle waste biomass as a construction material and use at large scale. In this study, wood and textile are feedstocks to prepare biochar and investigate their characterization. This study researched the information of different biochar by some basic parameters such as yield and water absorption. The pyrolysis of wood, textile and food waste was implemented to make different biochar. Meanwhile, the temperature was different according to these materials. 500°C of pyrolysis temperature was used to make wood and food biochar and 400°C and 300°C were for wood and textile biochar. The result explained that with increasing of temperature, the yield of wood and textile biochar was reduced.
Simulation Study on the Explosion Characteristics of Premixed Hydrogen-air Mixtures
Authors: Xiong Yanyi , Ma Yiwei , Zhao Huiping , Hu Yang
Published: August 2020

In order to study the explosion characteristics of hydrogen in the air and the influence of concentration on the explosion characteristics of hydrogen, the fire and explosion of small-scale hydrogen cloud with different concentration are simulated. The distribution of explosion characteristic parameters, such as overpressure, temperature and velocity, as well as the change rule with time, are obtained. The explosion characteristic parameters in horizontal and vertical directions are discussed The results show that under the influence of the ground and gravity, oblate elliptical fireballs with horizontal direction larger than vertical direction are formed in the early stage of ignition development. With the continuous combustion, they develop into hemispherical fireballs with the diameter of the ground and spread around. The influence of concentration on the law of fire and explosion is studied, and the maximum overpressure under different concentration is obtained, which provides support for building the fire field model of liquid hydrogen leakage. It is also of great significance for the evaluation of explosion hazards and the design of corresponding protection system.
Isolated carbonate platform reservoir multiple grouped discrete fracture network modelling
Authors: Zeng Xing , Song Heng , Xu Anzhu , Liang Xiuguang , He Congge , Liu Yunyang , Li Changhai , Luo Erhui , Chen Song
Published: August 2020

The fracture distribution on isolated carbonate platform is complicate congregation, it is necessary to accurately characterize fracture for oilfield development purpose. Based on the imaging logging fracture interpretation, this study analyzed the fracture grouping condition by sedimentary facies belt, also evaluated corresponding fracture intensity and orientation parameters; the fracture orientation trend for azimuth continuously changes fracture group can be established using the fracture group azimuth parameter; the intensity property calculation of each fracture group was carried out by Sequential Gaussian Simulation method under the seismic curvature volume control; each group’s discrete fracture network calculated from fracture intensity property and the analyzed fracture parameters accurately described the fracture distribution and orientation, the all groups together upscaled fracture property model shows permeability which consistent with with geological concept. This study shows: fracture features significant differentiated in each sedimentary facies belt on isolated carbonate platform, reservoir fracture can be characterized reasonably and accurately by azimuth trend control, thus lay the foundation for the reservoir simulation.
Study on the catalytic performance of Ag-P/HZSM-5 Catalyst for n-heptane at different reaction temperature and residence time
Authors: Miao Guangfa
Published: August 2020

One of the key technologies for the catalytic cracking of alkanes to produce low-carbon alkenes is the development of high-efficiency catalyst. This research prepared Ag-P/HZSM-5 and it had good regeneration performance. The continuous reaction regeneration experiment was carried out on the circulating fluidized bed experimental device, and the catalytic performance of n-heptane was investigated under the conditions of different reaction temperature and different residence time. The results showed that the conversion and yield of each product increased gradually with the increase of residence time, and the conversion rate of the reaction increased rapidly with the increase of reaction temperature. This can provide a basis for the research and development of new catalysts.
Research on prediction model of construction period of overhead line project based on BP neural network
Authors: Luo Kewei
Published: August 2020

With the stable development of economy and society, the power load increases year by year, so the power transmission company needs to build enough transmission lines to ensure the power supply. Overhead line project is the most commonly used form of transmission line, but the overhead line project often encounters the situation that cannot be completed on time, which affects the satisfaction of users’ electricity demand. Therefore, it is necessary to reasonably predict the construction period of the overhead line project, so as to provide a reasonable reference for the formulation of the production plan of the grid company. Firstly, this paper analyses the key factors that affect the construction period of overhead line project. Based on the BP neural network method, the construction period prediction model of overhead line project is established. The accuracy of the prediction is high.
Physicochemical characterization of pineapple peel wine
Authors: Zhang Li , Lu Wencai , Yuan Yuan , Wang Xiaofang , Zhou Wei , Liao Liangkun , Li Jihua
Published: August 2020

Pineapple peel was used for the elaboration of wine as an alternative to traditional fruit wine. The evolution of quality parameters of the wine throught the whole winemaking process was monitored. Significant changes occurred over the winemaking process were noted. Results pointed out that the utilization of pineapple peel in the fermentation of fruit wines was a viable alternative, which not only made full use of fruit waste resources, but also developed a new product into the market.
Research on Simulation Analysis of Valveless Hydraulic Servo System
Authors: Yahya Al-tayari Abdulmajid Mohammed , Siyu Chen
Published: August 2020

The hydraulic transmission technology is widely used in the industrial field. With the continuous development of microelectronic technology, valveless electro-hydraulic servo technology came into being. Aiming at the problems such as slow response speed and poor displacement tracking accuracy, this paper builds a simulation model of the forward and reverse displacement of the valveless electro-hydraulic servo system, and uses AMESim and simulink software to build the hydraulic part simulation and motor part simulation of the system respectively. A fuzzy PID controller is introduced and simulation is performed with the addition of the fuzzy PID controller to improve the overall performance of the valveless electro-hydraulic servo system.
Single-pole grounding fault location method for flexible HVDC transmission lines
Authors: Bian Jingfei , Dong Weiguang , Liu Jiongdei
Published: August 2020

One of the key problems of flexible HVDC transmission line is HVDC transmission fault location. A fault location method based on an improved traveling wave natural frequency flexible HVDC transmission line single-pole ground fault is proposed. The integrated empirical mode is used to decompose the fault signal to obtain the required traveling wave component, and then the improved MUSIC algorithm is used, according to the frequency spectrum analysis obtains the natural main frequency, and uses the relationship between the natural frequency and the fault distance to gain the fault location. Finally, use PSCAD to build simulation for simulation test and combine MATLAB fault location algorithm program to get the fault distance. The simulation results show that the proposed ranging algorithm is not affected by transition resistance and fault distance, and can accurately obtain the fault point distance, which shows the feasibility and effectiveness of the proposed fault ranging method.
Application of regional energy criterion in the prevention and control of coal mine rockburst
Authors: Meng Fanbao , Huang Jing , Xiao Peng , Pang Da , Jing Honghai
Published: August 2020

The current coal mine dynamic disasters severely restrict the high production and efficiency of coal mines. How to use modern mechanics to predict the rockburst scientifically and accurately has been paid more and more attention. In this study, the mechanism of coal mine rockburst is studied by the theory of fracture mechanics, the evolution process of coal mine rockburst is revealed from the energy point of view, the regional energy criterion of coal mine rockburst risk is established. The distribution of stress and plastic zone in the field is analyzed by FLAC3D. Based on theoretical analysis, the elastic energy cloud chart is established by using the FISH command to simulate the energy accumulation of roadway excavation. The results show that the tendency criterion of rockburst based on elastic strain energy well reflects the stage rule of damage evolution in the process of mining stress evolution, which provides an effective test basis for evaluating the risk of rockburst through energy parameters in the engineering field. This research has a certain theoretical guidance and practical value l significance for the prevention of rockburst.
Risk identification method of power grid division based on power flow entropy
Authors: Yangyu Hu , Qidi Huo , Xiaojun Tang , Meng Chen
Published: August 2020

This research introduced a new way to identify the weak area of power grid by the maximum entropy increase. The stable quantification of grid is judged by weighted power flow entropy index. The index of weighted power flow entropy can quantitatively evaluate the ordered stability degree of system key facts. A large number of simulation calculations of IEEE39 node system show that when the entropy of weighted power flow increases to 40-50% or more, the power grid is easy to enter the self-organized critical state, that is, the risk of blackout increases significantly. This paper studies the influence of the load growth in different regions on the entropy index of the whole system, and selects the region with the largest entropy increase as the weak region. The feasibility and effectiveness of the proposed method are verified by taking an actual power grid as an example.
Study on the application of ultra-high pressure hydraulic slotting in low permeability coal seam
Authors: Li Chengcheng
Published: August 2020

In view of the difficulty in solving the problem of coalbed methane drainage and mining connection in Wangpo coal mine, a new layout method of slotted hole and common hole is put forward by adopting the ultra-high pressure hydraulic slotting technology and combining with the characteristics of coal seam. The drilling construction technology and construction process are optimized. The amount of coal discharged by slotted hole is statistically analyzed, and the gas drainage concentration and extraction of common hole in slotted hole are investigated. The results show that the ultra-high pressure hydraulic slotting radius is 1.60m ∼ 2.26m, the average gas extraction concentration of slotted borehole is 54.88%, the pure gas extraction of slotted borehole is 51.4% higher than that of ordinary borehole, and the time of reaching the standard is 37.5% ∼ 50%. Therefore, the ultra-high pressure hydraulic slotting technology can better solve the problem of increasing permeability of low permeability coal seam, and provide a new way for the prevention and control of coal mine gas disaster.
Study on the Combined Conditioning Effect of High Efficiency Dehydration of River Sediment
Authors: Lin Jieli , Huang Minyi , Xie Zhihao , Liu Guohui , Zhu Haocheng , Yu Renrong
Published: August 2020

It is the most difficult problem for treating river sediment through the work of the whole river regulation. How to solve the problem of low efficiency of river sediment dewatering has become an urgent problem. In this paper, the sediment from the river of Chencun town in Foshan was chosen as the research object. Different kinds of conditioners were selected for single factor experiment, compound conditioning experiment of inorganic coagulants and organic flocculants, and combined conditioning experiment of adding self-made conditioner. The sedimentation speed, the turbidity and the water content were measured for analysis of the change of dehydration performance. The results showed that the effect of CPAM conditioning was the best in case of single factor experiment with the speed of 1.76 cm.min−1, the turbidity of 0.82 mg.L−1 and the water content of 60.21%. The lowest water content was under 60% in case of compound conditioning. When self-made PSM was combined with inorganic and organic conditioning for the sediment, the water content became 43.15% where the speed and the turbidity were equal to 2.80 cm.min−1, 0.23 mg.L−1, respectively. Therefore, the combined conditioning scheme not only improved the dehydration rate of sediment, but also improved the degree of sediment dehydration, which achieved the goal of high efficiency dehydration and low cost.
Research on Integration of Digital Protection of “Cultural Relics” Architecture and Virtual Reality Technology
Authors: Hua Gao , Jianfeng Huang
Published: August 2020

With the rapid development of science and technology, virtual reality technology has increasingly important value and significance in various fields. At present, the traditional digital protection techniques of cultural sites are through manual repair, construction and restoration, or in the form of text, pictures, film and television materials to protect the site. These digital protection methods are too simple, the data is not stored for a long time and is particularly vulnerable to damage. Therefore, it is urgent to find and apply a suitable digital technology. This paper is a study of the integration of digital protection of “cultural relics” and virtual reality technology.
Research of Ecological Landscape Assessment System Based on UAV
Authors: zhaoming Wang
Published: August 2020

This paper is taking the Baise-Leye and Molin highway as the study area, using UAV technique to investigate the eco-environment. With the advancement of computer technology, especially the development of remote sensing technology, the paper is using the UAV technique in the field of highway engineering will be more profound. The authors are taking the UAV image to extract model. The authors carry out highway environment simulation analysis.
Study on Operation Mode of High Speed Express
Authors: Meng Xiangru
Published: August 2020

With the rapid development of China’s market economy, the specialization of the industry tends to mature, and the modern logistics industry also presents a new development trend. Freight is an important link in modern. As a great artery of our national economy, railway plays an important role in modern logistics system. The demand for fast freight and high value-added transportation is increasing rapidly, which will promote the development of railway and bring opportunities and challenges to railway. Consumers can choose express delivery through high-speed rail transport, the railway sector can also transport express delivery to promote profit growth. This paper first analyzes the connotation of the operation mode of high-speed express delivery, analyzes the related enterprises of high-speed express delivery, compares and analyzes the existing three operation modes of self-organization, agent cooperation and strategic alliance, and puts forward the development countermeasures of highspeed express delivery in China.
Research on Indoor Patrol Robot Location based on BP Neural Network
Authors: Dong Liguo , Lv Junhao
Published: August 2020

With the development of science and technology, patrol robots play a more and more important role in indoor monitoring. It is the location of the abnormal situation that the most important task of the patrol robot is to display accurately, so studying its location is of vital significance. In the case of known indoor maps, it is indispensable for patrol robots to select the odometer which achieves accurate positioning. The traditional odometer is mainly realized by means of displacement, laser signal or multi-sensor fusion. However, the positioning often fails due to problems such as mechanical structure, error accumulation, power consumption and heating. In addition, the phenomenon that peripherals occupy limited robot resources is also prominent. To this end, this paper proposes to use BP neural network instead of sensors to obtain the odometer. This method is that the laser data, constructing the map of the robot, and the BP neural network determined are combined to achieve precise positioning and reduce development costs. Experiments have proved that this method may be used to improve the endurance of the robot battery in addition to accurate positioning.
A summary of research on customized bus route optimization for commuter needs
Authors: Lang Guoling
Published: August 2020

In order to solve the problems of inadequate existing road resources, rapid development of motor vehicles, and low comfort of traditional buses, a humanized customized bus is proposed, in which the network of customized buses is a key part of its operation. This article mainly summarizes the optimization of the customized bus line network at domestic and abroad, and finally draws the conclusion of this article.
Simulation study on Multi-parameter Detection method of polluted Water quality based on Sponge City
Authors: Zhong Wei , Zhao Xinfei
Published: August 2020

With the accelerated pace of urbanization, the construction of sponge cities is particularly essential for maintaining the ecological environment. Given the traditional multiparameter detection of heavily polluted water quality in cities, there are many problems, such as long completion time, low accuracy, high cost. A multi-parameter detection method of water quality based on the random forest classification algorithm is proposed. Through the analysis of urban heavily contaminated water quality, the probability synthesis matrix of heavily polluted water quality index is obtained by combining the water quality fluctuation probability of a single parameter and the dynamic correlation coefficient of multi-parameters. The membership function of the fluctuation of the treated water quality index is obtained, and the weak correlation among the water quality indexes is removed by the obtained membership function, and the strong relationship characteristic quantity of the water quality index is obtained, which is input into the random forest classifier to complete the multi-parameter detection of river water quality.
Research on Rapid Vegetation Extraction Based on UAV image in Desert and Gobi Area
Authors: zhaoming Wang
Published: August 2020

In this study, high-resolution uav platform and motion structure modeling technology were used to research. Based on uav-image, vegetation coverage was automatically estimated by decision tree algorithm, and superimposed with DEM data to analyze the spatial distribution characteristics of vegetation in gobi region and its relationship with terrain. The results show that, based on the high definition image of UAV, the uav high precision image analysis platform is used to extract the sparse vegetation coverage in the Gobi region, and good accuracy is obtained. The use of uav image data has a good applicability for analyzing the sparse vegetation distribution characteristics in the Gobi region.
Solution of seepage field in different soil layers of concrete dam foundation by flow net method
Authors: Zhang Miao , Yao Duoxi , Lu Haifeng , Wang Hang
Published: August 2020

Because of the seepage problem of concrete dam foundation, the water head, pore water pressure, hydraulic gradient and seepage velocity of each point in the seepage field are obtained by drawing flow net, and finally the seepage flow is obtained to predict the seepage of dam foundation. In this paper, the flow net diagram is used to solve the pore water pressure at the fixed point of the dam foundation soil layer under three different conditions: homogeneous isotropy, homogeneous anisotropy and layered soil. The calculation accuracy of the flow net method is verified through the calculation with the finite difference software FLAC3D numerical analysis. The results indicated that the pore water pressure of the three kinds of dam foundation soil layers calculated by the flow net method is more similar from that calculated by the numerical method, which indicates that the flow net method has high accuracy and can be used in some engineering practice with difficult modeling.
Study on Transformation and Migration of Antimony Impurity in Wet Recovery of Waste Lead Paste
Authors: Cao Huiqiu
Published: August 2020

The existing forms of antimony impurities in lead paste were analyzed, and the migration and transformation rules of antimony impurities in the process of recovering waste lead paste by leaching with organic acid system were studied. The experimental results show that when the dosage of leaching agent is constant, the more impurities transfer to the filtrate with the extension of reaction time. The conversion rate of antimony is relatively high, reaching about 97.0%. Cycle experiments show that with the increase of cycle times, the antimony content in the liquid phase decreases. By the third cycle, the proportion of antimony entering the filtrate is only 38%, and most antimony impurities enter the solid phase.
LCA evaluation system and benefit analysis of green Highway technology
Authors: Li Feifei
Published: August 2020

Aiming at the problem of all kinds of green road technology is difficult to compare with, energy conservation and emissions reduction from the technical feasibility and economic benefits, etc. Build green road technologies LCA evaluation system is put forward, and with G312 Suzhou western engineering comprehensive benefit analysis as an example, the comprehensive benefit of the most significant, have scale, resource investment suitable green road technologies; the breakthrough and innovation of technical bottleneck problem is the fundamental power to promote the development of green highway. The premise of integrating green concept into the whole life cycle of highway construction is not only the preliminary planning layout research according to local conditions, but also the basis of reasonable selection of suitable green highway technology.
Application of Enzyme Technology in Food Processing and Testing
Authors: Tianfei Dong
Published: August 2020

The enzyme itself is a catalyst, which can undergo hydrolysis reaction, oxidation reaction and synthesis reaction, and the safety and reaction efficiency of enzyme technology are relatively high. The effective application of enzyme technology in food processing and food testing can improve processing efficiency and testing efficiency. Research and analyze the specific application of enzyme technology in food processing and testing, and explore the application value of enzyme technology. It can promote the further development of enzyme technology and has a positive significance for promoting the long-term healthy development of my country’s food processing industry.
The bitter truth about gate-based quantum algorithms in the NISQ era
Authors: Leymann Frank , Barzen Johanna
Published: August 2020

Implementing a gate-based quantum algorithm on an noisy intermediate scale quantum (NISQ) device has several challenges that arise from the fact that such devices are noisy and have limited quantum resources. Thus, various factors contributing to the depth and width as well as to the noise of an implementation of a gate-based algorithm must be understood in order to assess whether an implementation will execute successfully on a given NISQ device. In this contribution, we discuss these factors and their impact on algorithm implementations. Especially, we will cover state preparation, oracle expansion, connectivity, circuit rewriting, and readout: these factors are very often ignored when presenting a gate-based algorithm but they are crucial when implementing such an algorithm on near-term quantum computers. Our contribution will help developers in charge of realizing gate-based algorithms on such machines in (i) achieving an executable implementation, and (ii) assessing the success of their implementation on a given machine.
Perovskite solar cell performance assessment
Authors: Unger Eva , Paramasivam Gopinath , Abate Antonio
Published: August 2020

Astounding progress in achieved power conversion efficiencies of solar cells based on metal-halide perovskite semiconductors has been achieved. Viable assessment of the long-term device performance is, therefore, now the most critical aspect to reliably predict device’s long-term performance. Standard testing protocols to enable cross-laboratory comparison need to be established and adopted. Apart from protocols targeting the assessment of device performance and stability, procedures to investigate potential meta-stabilities in devices under different operation conditions are required to describe degradation mechanisms. This understanding will guide further optimization of materials and devices. In this perspective, we emphasize the importance of wide-spread reporting of experimental data in common databases to keep track of the state-of-the-art of perovskite solar cell performance and stability achieved.
Hybrid photoanodes for visible light-driven water oxidation: the beneficial and detrimental effects of nickel oxide cocatalyst
Authors: Longchin Pimchanok , Mitoraj Dariusz , Reyes Oliver Mendoza , Adler Christiane , Wetchakun Natda , Beranek Radim
Published: August 2020

Hybrid photoanodes comprising polymer-based light absorbers coupled to oxygen-evolving cocatalysts represent a promising, yes still underdeveloped, approach to photoelectrochemical splitting of water into hydrogen and oxygen. In this study, we investigate nickel oxide (NiO
x
) nanoparticles as a water oxidation catalyst in hybrid photoanodes based on polymeric carbon nitride (CN
x
) supported on electron-collecting mesoporous TiO2 support. The performance of the resulting TiO2–CN
x
/NiO
x
photoanodes is evaluated with respect to our previous results on hybrid TiO2–CN
x
photoanodes modified with IrO
x
and CoO(OH)
x
cocatalysts. The deposition of NiO
x
into TiO2–CN
x
photoanodes enhances significantly the photocurrent (from <8 μA to >250 μA cm–2 at 1.23 V vs. RHE) under visible light irradiation (λ > 420 nm, ∼200 mW cm−2) and triggers the photoelectrocatalytic oxygen evolution. No oxygen evolution was observed without a cocatalyst. As compared to photoanodes modified with IrO
x
or CoO(OH)
x
, the TiO2–CN
x
/NiO
x
photoanodes excel by the very negative photocurrent onset potential (0 V vs. RHE), which we ascribe to good hole-extracting properties of NiO
x
. However, the comparatively low Faradaic efficiencies for oxygen evolution (∼18%) and dramatically decreased operational stability of the photoanodes indicate that the extracted holes do not efficiently oxidize water to dioxygen, but instead accumulate in the NiO
x
particles and increase thus the oxidative photodegradation of the photoanodes. Our study highlights the fact that employing outstanding electrocatalysts like NiO
x
in photoelectrochemical water-splitting systems does not necessarily lead to satisfactory results, especially when the photoelectrode cannot be operated at optimal pH due to light absorber stability issues.
Minimum weight disk triangulations and fillings
Authors: Benjamini Itai , Lubetzky Eyal , Peled Yuval
Published: August 2020

We study the minimum total weight of a disk triangulation using vertices out of{1,…,n}\{1,\ldots ,n\}, where the boundary is the triangle(123)(123)and the(n3)\binom {n}3triangles have independent weights, e.g. Exp(1)\mathrm {Exp}(1)or U(0,1)\mathrm {U}(0,1). We show that for explicit constantsc1,c2>0c_1,c_2>0, this minimum isc1log⁡nn+c2log⁡log⁡nn+Ynnc_1 \frac {\log n}{\sqrt n} + c_2 \frac {\log \log n}{\sqrt n} + \frac {Y_n}{\sqrt n}, where the random variableYnY_nis tight, and it is attained by a triangulation that consists of14log⁡n+OP(log⁡n)\frac 14\log n + O_{P}(\sqrt {\log n})vertices. Moreover, for disk triangulations that are canonical, in that no inner triangle contains all but O(1)O(1)of the vertices, the minimum weight has the above form with the law ofYnY_nconverging weakly to a shifted Gumbel. In addition, we prove that, with high probability, the minimum weights of a homological filling and a homotopical filling of the cycle(123)(123)are both attained by the minimum weight disk triangulation.
Bicuspid aortic valve and aortopathy: novel prognostic predictors for the identification of high-risk patients
Authors: Longobardo Luca , Carerj Scipione , Bitto Alessandra , Cusmà-Piccione Maurizio , Carerj Maria Ludovica , Calabrò Maria Pia , Di Bella Gianluca , Licordari Roberto , Squadrito Francesco , Khandheria Bijoy K , Zito Concetta
Published: August 2020

Aims

Bicuspid aortic valve (BAV) may be complicated by aortic aneurysms and dissection. This study aimed to evaluate the prognostic efficacy of markers from cardiac imaging, as well as genetic and new biomarkers, to early predict aortic complications.

Methods and results

We re-evaluated after a mean time of 48 ± 11 months 47 BAV patients who had undergone previous echocardiography for evaluation of aortic stiffness and 2D aortic longitudinal strain (LS) (by speckle-tracking analysis), and who had given a blood sample for the assessment of a single-nucleotide polymorphism of elastin gene (ELN rs2 071307) and quantification of elastin soluble fragments (ESF). Surgical treatment of aortic aneurysm/dissection was the primary endpoint, and an aortic dimension increase (of one or more aortic segments) ≥1 mm/year was the secondary endpoint. Nine patients underwent surgical treatment of ascending aorta (AA) aneurysms. Out of the 38 patients who did not need surgical intervention, 16 showed an increase of aortic root and/or AA dimension ≥1 mm/year. At multivariate Cox regression analysis, an impaired AA LS was an independent predictor of aortic surgery [P = 0.04; hazard ratio (HR) 0.961; 95% confidence interval (CI) 0.924–0.984] and aortic dilatation (P = 0.007; HR 0.960; 95% CI 0.932–0.989). An increased quantity of ESF was correlated (P = 0.015) with the primary endpoint at univariate Cox regression analysis but it did not keep statistical significance at multivariate analysis.

Conclusion

In BAV patients, impairment of elastic properties of the AA, as assessed by 2D LS, is an effective predictor of aortic complications.