bluuebunny/crossref_metadata_2025 huggingface dataset:
Mid and long-term hydrological classification forecasting model based on KDE-BDA and its application research
Authors: Liu Yong , Yin Zhijie , Zhang Ying , Wang Qin
Published: November 2019

In view of the uncertainties in the current mid and long-term hydrological forecast results, a mid and long-term hydrological classification forecasting model based on KDE-BDA is built and its application research is performed. The kernel density estimation method (KDE) is used to improve the distribution density function estimation method in the conventional Bayesian discriminant method (BDA). Based on this, a mid and long-term hydrological classification prediction model based on KDE-BDA was built. An example of its application is demonstrated in the runoff forecast of the Danjiangkou Reservoir in the autumn of September. The results show that different forecasting factors have different forecasting ability for runoff classification (flood, normal, dry). Among them, the 500hPa height field factor has higher forecasting ability for the Danjiangkou runoff category (flood, normal, dry), and the 100hPa height field factor, SST and circulation characteristics have a good indication of the runoff’s flood state. The results of Half-Brier score show that the combined forecasting model combines the forecasting advantages of each factor, so the forecasting effect is the best. The pass rate in the simulation period was 89.8%, and the pass rate in the inspection period was 87.5%. The simulation and forecast results were relatively stable.
Research on Solar Energy Resources in Hexi Region of Gansu Province
Authors: Dan Wu , Tingting Meng
Published: November 2019

The excessive exploitation and utilization of non-renewable resources by humans has caused a lot of energy depletion, which has caused great changes in the climate system and has a great impact on human production and life. The development and utilization of new energy by human beings has become a hot issue in recent years. As the most important renewable green energy source, solar energy resources have been widely used in many countries and regions. The paper analyzes the solar radiation in the Hexi region for about 21 years in time and space to analyze the availability of solar energy resources in Hexi area.
Experimental study on energy-saving of highway tunnel lighting with symmetric lamp distribution
Authors: Yang Chao , Fan Shijuan
Published: November 2019

In order to study the energy-saving of highway tunnel lighting experimentally with low cost, a similar tunnel model was designed and used for the lighting experiment. Yanlieshan highway tunnel was selected as the study object. On the basis of the tunnel structure sizes (TSS) and the selected LED lamps, the optimized symmetric lamp installation parameters (OSLIPs) for energy-saving were obtained with the lighting parameters optimization model (LPOM) on symmetric lamp distribution (SLD) from reference. Based on the TSS and the OSLIPs, a simulation experiment of the tunnel lighting was accomplished with DIALux. A similar tunnel model was designed and built according to the TSS and similarity theory, and a tunnel model lighting experiment with SLD was carried out. The road-surface-illuminance (RSI) data of the tunnel model lighting experiment were compared with the simulation experiment results. The comparison of horizontal RSI from the two methods coincide well, which proves the LPOM is correct, the lighting experimental study with similar tunnel model is feasible and the experiment method in this study is valid.
Research on Chongqing Mountain Flood Disaster Risk Assessment System Based on AHP-GIS
Authors: Qianzhu Zhang , Huoming Zhou , Yang Lu , Ruiyi Zhao , Qiang Gao , Jianmei Yan , Kun Sun
Published: November 2019

The risk of mountain flood disasters is the fundamental factor restricting the occurrence of disasters. The analysis and assessment of disaster risks is the basis for disaster risk management. Through the investigation of mountain flood disasters from 2013 to 2015, the basic information such as hydrometeorology, topography, socio-economic and mountain flood disaster prevention and control situation in mountain flood disaster prevention and control areas were found out. Taking the city of mountains-Chongqing as an ex-ample, this paper considered the results of mountain flood disaster investigation and evaluation in recent years, and divided the risk evaluation indicators into two types of first-level indicators: rainfall and under-lying surface, and the secondary indicators were subdivided into comprehensive rainstorm indicators, critical rainfall, topographic relief, land use convergence capacity, soil texture and river network density. Using AHP to set the weight coefficient of each level indicators, those showed that heavy rain conditions, critical rainfall and topographic relief were important factors impacting the mountain flood disasters, and the land use convergence capacity had the minimum weight coefficient. Through GIS superposition analysis, the risk index of mountain flood disasters in the region were obtained. The western, southeastern and northeastern Chongqing were high risk areas for mountain flood disasters, which provided decision-making basis for mountain flood disaster risk management.
Experimental Study of High Purity CO2 Concentration from Syngas by a Dual-bed Six-step Pressure Swing Adsorption Process
Authors: Chou Cheng-Tung , Hsu Tsai-Feng , Shen Chen-Yu , Lee Shao-Hua , Yang Hong-Sung
Published: November 2019

With the industry development, the concentration of greenhouse gas increases year by year. Consequently, how to reduce the emission of greenhouse gas has become an important issue all over the world. This research is the experimental study of concentrating high purity CO2 from syngas after oxy-fuel combustion by a dual-bed six-step pressure swing adsorption (PSA) process. The composition of feed gas used in the process was simulated as 95% CO2, with N2 balanced. We chose UOP 13X zeolite as the adsorbent according to the adsorption capacity and selectivity of CO2 over N2 comparing to other adsorbents studied. The breakthrough and desorption curves were discussed by changing different feed flow rate and temperature. Next the carbon dioxide was purified by a dual-bed six-step PSA process. After exploring the effects of variables on performance of PSA process, we found the best operating conditions for obtaining high purity carbon dioxide among our experiments. The best operating conditions are feed pressure 3.45 atm, countercurrent depressurization pressure 0.48 atm and purge to feed ratio 0.105. The experimental results of best conditions are 99.94% purity and 42.84% recovery of carbon dioxide at bottom product, energy consumption 0.304 GJ/tonne CO2 and productivity 0.136 kg CO2/kg adsorbenth.
Study on Evaluation System of Green Landfill Based on Life Cycle —— Illustrated by the Case of Hangzhou Tianziling Landfill
Authors: Bingru Zheng , Die Chen , Chi Guan
Published: November 2019

Recently, the environmental problems of Hangzhou Tianziling Landfill have brought great troubles to the lives of nearby residents. Landfill is the main method of garbage disposal. The requirement of green environment protection about landfill is becoming higher and higher, and the way in which the important indicators affects the environmental of landfill has also followed by lots of interest. In this paper, on the basis of the whole life cycle evaluation index system of landfill, the evaluation index of green landfill is increased, and then the evaluation index system of green landfill based on the whole life cycle is constructed by using hierarchical analysis method. Using Hangzhou Tianziling Landfill as a case to establish the practical model; establishing the hierarchical index weight and calculating it. Comparing the weight of each index shows that the proportion of odor concentration in environmental protection index is largest, and finally the comprehensive evaluation score of Hangzhou Tianziling Landfill based on life cycle is obtained.
Stability Control of Surrounding Rock in Large-Section Weak- and Thick-Coal Open-cutting Roadway in Deep Mine
Authors: Fan Jihong , Shen Shibao , Tao Guangzhe , Dai Desheng , Wu Jilu
Published: November 2019

In view of the supporting problems in the large-section weak- and thick-coal open-cutting roadway in the deep coal mines, this paper adopts numerical simulation, theoretical analysis, and field measurement to study the deformation and failure law of the surrounding rock and explore corresponding control measures. The results show that: 1) The surrounding rock of open-cutting roadways is divided into a fracture-through zone, a fracture development zone, and a micro-fracture zone. When the width of the roadway is 12 m, the maximum height of the fracture-through zone is 2.6 m, and the two-side fracture zone is 1.1 m, and the height of fracture-through zone of the top plate is 1.5 m. 2) Considering the actual geological production conditions, this paper proposes the control measures combining high-strength bolt support, large-diameter anchor cable support, and single column reinforcement, and expounds its control mechanism. In addition, on-site industrial test verifies the rationality of the supporting plan.
Research on the Influencing Factors of National Energy Economy Based on Fixed Effect Model
Authors: Jinghao Jia , Jianhong Cheng
Published: November 2019

This paper analyzes and studies the influencing factors of national energy economy. By constructing a fixed effect model and taking China as an example, it makes a statistical analysis of the influencing factors of China’s national energy economic efficiency. This paper Introduce China’s empirical data from 2000 to 2010 to deepen the understanding of energy issues, and then analyze the inherent causes of the situation from the actual situation of the country. This study can quantitatively analyze the status quo and differences of energy economic efficiency among countries and regions, and study the relationship between its influencing factors on energy economic efficiency, which can promote the sustainable and coordinated development of the country.
Research on Land Use Ecological Security Pattern Construction of Hilly Cities in Hunan
Authors: Zhai Duanqiang , Xia Huiwen
Published: November 2019

The Landsat satellite image of Liuyang City was selected in June 2018, and the land use landscape type map was generated based on RS and GIS technology. The landscape index was calculated by the FRAGSTATS to analyse the landscape pattern of urban land use in Hunan hilly areas, and the minimum cumulative distance model was used to construct the urban ecological pattern. The results showed that: ①The most dominant landscape types in the city area were forest lands with high degree of aggregation and cluster distribution. The fragmentation of landscape types in urban areas was obvious, especially the grassland fragmentation. ②There are few landscape types in the city area, and there are obvious dominant landscapes. ③The article builds an ecological security pattern by searching for ecological sources, corridors and nodes, and guarantees the ecological security of hilly urban cities.
Effect of C/N on removal of chlorpyrifos in constructed wetland system
Authors: Fan Zhiyu , Sun Xuefei , Quan Yue , Zhu Weihong , Jin Mingji
Published: November 2019

This study used C/N as a variable to investigate the removal effect of chlorpyrifos and the microbial community structure in the constructed system. As a result, with the increase of C/N within the range of 2-20, the removal rate of chlorpyrifos, the system matrix and the concentration of chlorpyrifos in plants all increased. The diversity of microbial community in the system was significantly affected by C/N. When C/N was 5, the microbial community diversity was the most abundant. Proteobacteria and Alphaproteobacteria were the dominant phylum and class.
A Review of Fundamental Research on Hydraulic Fracturing of Glutenite Reservoirs in China
Authors: Bin Xie , Bin Zeng , Guodong Wu , Zhaozhong Yang , Jianlin Chen , Jigang Meng , Xiaogang Li
Published: November 2019

There are abundant tight oil and gas resources in glutenite reservoirs in China, and hydraulic fracturing is essential for developing this kind of resources. At present, the basic scientific problems involved in hydraulic fracturing of glutenite reservoirs, including simulation of fracture propagation, proppant transport and fracture conductivity, are not systematically clarified yet. The deficiencies of existing research ideas and methods are summarized, then suggested solutions and development prospects are proposed. The analysis shows that for the fracture propagation experiment, the establishment of a scalable glutenite sample preparation method and the experimental parameter conversion method is an urgent problem to be solved. The particle flow code (PFC) method has advantages in simulating the fracture propagation in microscopic scale. However, the simulation of fracture propagation in oilfield scale faces the problem of cross-scale calculation, so establishing a fast and effective cross-scale simulation method is very important. For the proppant transport experiment, the key is to develop plates with unidirectional filtration and different roughness to simulate the hydraulic fracture surface of glutenite reservoirs. The CFD-DEM coupling method to simulate the proppant transport has a good prospect, but it is necessary to consider the special properties of the glutenite reservoirs, and improve the mathematical model and explore corresponding solution method. The key to the experimental research of the fracture conductivity is to make samples that meet the size and shape requirements. Downhole drilled core, man-made rock and 3D printing technique can be adopted for sample procession. For computer simulation of conductivity prediction, combining PFC with CFD method to predict the conductivity of glutenite is an important exploration direction in the future.
Study on the factors affecting the spatial distribution of heavy metal elements
Authors: Chen Fangyuan , Chen Xinmin , Zhu Fan , Sun Qi
Published: November 2019

The contents of As, Cr, Cu, Zn and Pb in soils of the central urban area of Nanjing Jiangbei New area are analyzed by interpolation analysis. The effects of pH value, soil texture and heavy metal species on the contents of heavy metals are studied. The results show that the contents of heavy metals in the study area are more than 1.5 to 6.3 times of the soil background value in Jiangsu Province. The content of heavy metal Cr is 31.92∼95.38 mg/kg, and some areas have already exceeded the control value of the second type of construction land in China, 78 mg/kg. The pH value is inversely proportional to the total heavy metal content, which indicates that it is more difficult to enrich heavy metal ions in alkaline environment. The soil texture in this area is dominated by sand grains, and the spatial distribution of sand grain content decreases from southwest to northeast. The clay content is positively correlated with the heavy metal content except Zn. The main forms of the five kinds of heavy metals in soil are residues, reaching 73.86%∼88.15%, and with the increase of heavy metals content in soil, the proportion of residual decreases.
Syntheses of Biodegradable Polylactides Catalyzed by Aluminum Complexes bearing Phenanthrene Derivatives for Polymerization of Lactides
Authors: Li Dongni , Gao Bo , Li Yanhui , Duan Qian
Published: November 2019

A methylaluminum Schiff base compound 1 bearing phenanthrene derivatives was made and used in the ROP of LA. Compound 1 was characterized by NMR and elemental analysis. Compound 1 with isopropyl alcohol exhibited good activity towards the polymerization experiment of LA. The ROP is in a coordination-insertion mechanism.
Lysimachia christinae polysaccharide mediated facile synthesis of gold-silver alloy nanoparticles for catalytic reduction of 4-nitrophenol
Authors: Liang Miao , Zhang Guo , He Yuan , Hou Pei , Li Meng , Lv Bin
Published: November 2019

We report here an environmentally benign and facile approach for the synthesis of gold-silver alloy nanoparticles. This approach involves the co-reduction of HAuCl4 and AgNO3 by employing Lysimachia christinae polysaccharide as both reductant and stabilizer without the introduction of any other surfactant. The formed gold-silver alloy nanoparticles exhibited relatively narrow distribution and good stability. Generation of the gold-silver alloy nanoparticles were observed by UV-vis spectroscopy, transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The reaction of 4-nitrophenol reduction was employed to evaluate the catalytic property of gold-silver alloy nanoparticles, and it was found that the alloy nanoparticles χ
Au = 0.5) have better catalytic performance than the corresponding monometallic nanoparticles.
Research on Substation Comprehensive Investment Demand Evaluation Model under the Background of Electricity Reform
Authors: Yang Zhilong , Liu Yamin , Xu Qinghua , Shi Xiaokun , Liu Hang
Published: November 2019

Based on the background of electricity transmission and distribution price reform, this paper focuses on the substation assets, through the influence analysis of reform policies to the power grid company operation and management, aimed at the high quality development of the company and power grid, to establish the substation comprehensive investment demand evaluation index system, specify the index calculation methods and evaluation principles, construct the substation comprehensive investment demand evaluation model, collect the actual data of a power grid company’s substations, measure and calculate, and put forward the substation investment and construction advice according to the results of the measurement, to assist the company for investment decision making.
Dynamic Analysis of Gearbox Transmission System Based on ADAMS Traction Locomotive
Authors: Lei Lei , Sui Yunan , Tianmin Guan
Published: November 2019

In order to verify the rationality of the design of the gearbox transmission system of the traction locomotive, based on the ADAMS software, the 3D model of the gearbox transmission system is established in CREO 3.0, and the dynamic model of the gearbox transmission system is built into the ADAMS for simulation. Analysis, the dynamic meshing force between the gears, the force of the bearing on the box, etc., and the obtained simulation values are compared with the theoretical values. The results show that the results obtained by ADAMS simulation fluctuate around the theoretical value, which verifies the reasonable design of the traction locomotive gearbox transmission system.
Stepwise Approach in Lagged Variables Time Series Modeling: A Simple Illustration
Authors: Yanti Yusma , Rahardiantoro Septian
Published: November 2019

Modeling approach in time series data commonly used to forecast the response variable based on the pattern of the predictor variables. The complicated cases occurred when in the model need the lagged variables from these variables. It can increase the number of predictor variables in the model. In this research, the increasing of number of predictor handled by the stepwise method in the regression analysis approach. All possible lag from the variables generated before the stepwise take action to choose the appropriate variables in the model. The illustration in this research based on the advertising-sales relationship of 36 consecutive months. Result of the model can determine the significance predictor variables in the model, and also can give the appropriate goodness of fit criteria for forecasting.
Book Embeddings of Infinite Sequences of Extended Periodic Regular Graphs
Authors: Pinontoan Benny , Titaley Jullia
Published: November 2019

A graph is extended periodic if it can be made up by gluing identical pieces together with a graph which is isomorphic to or subgraph of that piece, in a circular fashion. We consider an infinite sequence Hn
of extended periodic 4-regular graphs and an infinite sequence Mn
of extended periodic 5-regular graphs. A book is a collection of half-planes called pages, all having a common boundary called the spine. A book embedding of a graph G is to put the vertices of G on the spine and each edge of G is contained in one page. The minimum pages needed to embed a graph G into a book is called pagenumber of G. We determine the pagenumbers of Hn
and Mn
to be three.
A New 4-D Hyperchaotic System with Four-Scroll Hidden Attractor, Its Properties and Bifurcation Analysis
Authors: Dolvis L G , Vaidyanathan S , Jacques K , Sambas A , Sukono  , Mamat M
Published: November 2019

This paper announces a new four-dimensional hyperchaotic system with a four-scroll attractor and discusses its dynamic properties such as Lyapunov exponents, phase portraits, Kaplan-Yorke dimension and equilibrium points. Our calculations show that the new hyperchaotic system has no equilibrium point and hence it exhibits hidden attractor. Our new hyperchaotic system has three nonlinearities in total. A detailed bifurcation analysis has been presented for the new hyperchaotic system with four-scroll hidden attractor. Specifically, we discussed bifurcation analysis such as route to four-scroll hyperchaos, coexisting bifurcation, multistability, two parameter Lyapunov exponents and antimonotonicity.
The assessment of Danau Kota Lake water quality using chemometrics approach
Authors: Juahir Hafizan , Ghazali Adiana , Ismail Azimah , Mohamad Mahadzirah , Hamzah Firdaus Mohamad , Sudianto Sunardi , Mohd Lasim Mohd Lokman , Shahriz Mohamed Aidi
Published: November 2019

Danau Kota Lake is public attraction area, located in the middle area of Kuala Lumpur. An excessive count of visitors visiting the lake has weakening the lake water quality. The present study was driven to evaluate the lake water quality for environmental conservation. Some water quality and metals data were in-situ measured whereas some were collected for laboratory analysis. BOD, OG, AN and TC are identified as major pollutants towards Danau Kota Lake water quality. The decreasing concentration of DO and increasing of turbidity towards the deeper lake water column has been deteriorated the living water communities and caused hypoxic condition in the bottom water of Danau Kota Lake. Spatial variation of metals in the lake sediment has evidenced the accumulation of metals in the middle part of the lake area due to the sedimentation process. Based on PCA, the possible pollutant sources for this lake are the organic pollutants from the wastewater and industrial pollutants as well as the abundance of suspended algae. Since the water quality of Danau Kota Lake has marked some issues, the present study may assist Kuala Lumpur City Council to prevail the lake water quality challenge promptly by cost saving and in efficient manner.
Study on the properties of improved adsorbent of nitrogen oxides
Authors: Wang Fang , Li Mingjun
Published: November 2019

In this paper, sodium bentonite, zeolite and other natural minerals are used to make adsorption materials, and physical and chemical adsorption are combined to improve the adsorption efficiency of NOx. The adsorbents were modified by loading additives with high catalytic capacity for NO. Results showed that the improved adsorbent has high adsorption to NO, making NO easy to be oxidized into NO2 by the loaded metal oxides, thus NOx can be highly adsorbed and purified at room temperature.
Microstructure and Mechanical Properties of Selective Laser Melting 0Cr18Ni9 Stainless Steel
Authors: Huang Shuai , Guo Shaoqing , Zhou Biao , Liu Wei , Li Neng , Zhang Guohui , Chen Bingqing , Zhang Xuejun
Published: November 2019

The 0Cr18Ni9 samples were prepared by laser selective melting technique, and the effects of different power and scanning speed on the microstructure evolution were observed. Through the observation of the microstructure and the analysis of the densification test results, the optimum process parameter was 280W, 960mm/s. The tensile strength (678MPa) and yield strength (554MPa) of the transverse tensile specimens formed under this condition are higher than that of the longitudinal specimens. However, the longitudinal specimen is more plastic than the transverse specimen.
Study on Leaching Mechanism and Safety Evaluation of Lead and Zinc Contaminated Soil
Authors: Zhang Hua
Published: November 2019

Taking the tailing pond of the Qiaokou lead-zinc mine in Hunan province as the research object, the lead-zinc-contaminated soil was leached by citric acid, and the phase characteristics of the contaminated soil before and after leaching were analyzed by SEM-EDS, combined with BCR. The continuous extraction method was used to study the occurrence of four kinds of heavy metals in contaminated soil, and then analyze the potential migration and transformation ability and migration law to evaluate the potential hazards of heavy metals to the surrounding environment, and to repair the lead and zinc tailings pond. Provide theoretical basis and technical support with governance.
Terminal Vapor Recovery of Oil Tankers in China: Current Issues and Promotion Strategies
Authors: Li Yue , Cheng Jinxiang , Mao Ning , Xu Honglei , Zheng Chaohui , Li Mingjun
Published: November 2019

Terminal vapor recovery, a widely-applied technology for emission control on vapors of gasoline and other fuels at terminals, can effectively reduce the VOCs (volatile organic compounds) during the cargo loading procedure of oil tankers. This paper aims to provide a systematic analysis of the current situation and main issues of vapor recovery technology, proposals of basic principles, general strategies and specific tasks and programs for the promotion of the technology, as well as a reference for decision-making on the further development of terminal vapor recovery system in China.
Experimental Studies of Heat Transfer and Corrosion Resistance of Ni-W-P Coating under Supercritical Water
Authors: Ren L , Cheng Y H , Han Z T , Yang J Y , Tian X H
Published: November 2019

As the post-processing method of equipment and tubes is seldom used in the field of super-critical water (SCW), as well as the high cost and low heat transfer performance of some of the materials, more up-to-date methods were developed to inhibit oxidation of SCW. In this work, the ternary Ni-W-P coating was deposited on the sample surface. Structure and composition of ternary Ni-W-P coating were profoundly analyzed with scanning electron microscopy (SEM), energy disperse spectroscopy (EDS) and X-ray diffraction (XRD). Additionally, thermal conductivity meter was specially employed to study the performance of heat transfer behaviour, by means of heat-resistance method. After oxidation of SCW, amorphous Ni-W-P coating crystallizes to some extent and oxidation resistance of coating can be convincing. Nevertheless, the diffusion of metal cations and the growth of oxides are the vital factors inhibiting the oxidation of SCW. Furthermore, the thermal conductivity of ternary Ni-W-P coating decreases with the increase of tungsten content and the coating unquestionably shows better heat transfer performance in the field of nuclear waste disposal and transport.
Microstructure and properties of Cr12MoV die steel by laser quenching with different power
Authors: Yu Liu , Yuanpeng Tian , Hui Zhang , Haijing Zhang , Yang Li
Published: November 2019

In this paper, laser quenching on the surface of Cr12MoV cold-work die steel was carried out by CO2 laser. The laser scanning speed was 800mm/min, and the laser powers were 1200W, 1400W, 1600W and 1800W respectively. Thickness, microstructure, hardness, XRD, friction and wear properties of the quenched layer were investigated after laser quenching with different power. The results show that the thickness and martensite content in quenched layer increase gradually with the increase of laser power. The hardness of quenched layers have an increase firstly and a later decrease along with laser power. When the laser power is 1600W, the maximum hardness is 662.9HV. When the power is 1800W, microfusion appears on the surface, and the hardness of the quenching layer decreases. The wear volume of the sample first rises and then falls along with laser power. The minimum wear volume is 0.09mm3 at 1600W, and the wear volume is reduced by 92% of the original sample. Therefore, scanning speed of 800mm/min and laser power of 1600W can get the best microstructure and properties.
Preparation and properties of polycarboxylate superplasticizer with high water-retaining property
Authors: Li Xianghe , Hou Huanhuan , Wen Qingru , Guan Mengqin , Guo Xinqi
Published: November 2019

In this paper, ethyl glucose (Glc), 2-amino-4-methyl-5-phospho-3-pentenoate (AMEPA) and p-toluene sulfonic acid (PTS) were esterified, and the esterified products were polymerized with acrylic acid (AA), 4-hydroxybutylvinyl polyoxyethylene ether (VPEG), initiator (APS) and chain transfer agent (ME) in free radical solution to prepare polycarboxylate superplasticizer with high water retention. The performance test results show that the product has high water-reducing ratio and better workability when applied to concrete, which can effectively retain the moisture in concrete and ensure the stability of concrete fluidity.
Study on Mechanical Properties of Composites with Regular Distribution of Single Layer Ellipsoid Particles
Authors: Chen Keying , Zeng Liangcai , Chai Yufeng , Chen Juan
Published: November 2019

The impact of the size distribution of the reinforced particles on the mechanical properties of composite materials is studied, according to the corresponding parameters, the finite element model of the composites on the model of Al based SiC composites is established. With the method of finite element simulation, the surface displacement and stress distribution of particle reinforced composites whose surface is pressed by a line uniformly load is solved, the effects of reinforced particles buried depth, length to diameter ratio, the young’s modulus ratio of matrix and particles, and rotation angle on the mechanical properties of composites are also analyzed The article outlines concrete influences of the structure parameters and spatial distribution parameters of particles which distribute in the composites on the surface displacement and stress distribution of the composites.
Study on friction characteristics of micro-arc oxidation modification layer of titanium alloy surface in seawater environment
Authors: Xingsheng Lao , Xufeng Zhao , Yong Liu , Chunhui Dai , Wei Wang
Published: November 2019

In order to study the effect of surface microarc oxidation modification on the comprehensive properties of titanium alloys in seawater environment, the metallographic structure of titanium alloy Microarc oxidation modified surface layer and the basic physical parameters such as hardness, thickness and roughness were measured, and the PTFE, filled with 15% glass fiber +5% were filled with 25% fiberglass. The PTFE of graphite and the PTFE filled with 60% tin bronze were tested for friction by friction pair materials, and the wear amount and roughness of titanium alloy and Microarc oxidation modified surface layer were test in simulated sea water as 3.5% Nacl solution, and the results showed that the surface modification of titanium alloy by Microarc oxidation could significantly improve its hardness. The surface roughness can reach 3.2μm, and the friction coefficient of different matching pairs is small, while the surface wear of microarc oxidation modification is less than that of substrate wear.
Synthesis and corrosion Resistance of silane coupling agent modified graphene oxide/waterborne polyurethane
Authors: Shu S S , Wu L , Liu J M , Liu Y , Hu Y , Xu J H , Wang L
Published: November 2019

In this paper, graphene oxide (GO) is used as a matrix, and it is modified with a silane coupling agent (KH550) to prepare modified GO. The GO/waterborne polyurethane composite coatings with different contents are prepared by chemical grafting, and their structural characterization tests are carried out. The results show that the silane coupling agent can effectively modify GO, and the surface of the modified GO has more oxygen-containing functional groups. The added modified GO can effectively enhance the corrosion resistance of the coating, and the corrosion resistance of the composite coating was optimal when the mass fraction is 0.03%, and 5% corrosion occurs after 48 h, and the total corrosion time reaches 120h.
Preparation and molten salt corrosion behaviors of TiO2/Al2O3/Incone1625 composite coatings on the surface of Q235 alloy at 900 °C
Authors: Chen Tuchun , Bai Lingyun , Wen Kunkun
Published: November 2019

Sol-gel method combined with plasma surfacing was used to prepare TiO2/Al2O3/Incone1625 composite coatings on the surface of Q235 alloys. To investigate the corrosion resistance of this coatings, samples with Incone1625 single coating and TiO2/Al2O3/Incone1625 composite coating were corroded with NaCl and Na2SO4 salts with the weight ration of 1:1at 900 °C in air for 24 h. Molten salt corrosion thermodynamic results show the composite coatings caused lower oxidation weight gain than the sample with single coating. Combination of XRD and SEM results illustrates that the surface and cross-sectional morphology were composed of an outermost loose and cracked NiO and iron oxides layer for the Incone1625 coated sample. For the composite coating sample, the oxide film was composed of more compact NiO and Cr2O3 as the main layer. There were inner oxidation regions for both samples, but region for sample with composite coating was more thinner than that for sample with single coating. This work shows that TiO2/Al2O3/Incone1625 composite coating improves the molten salt corrosion resistance properties of the Q235 alloy at 900 °C by promoting the formation of the protective Cr2O3 film on the sample surface.
Optimization and transformation of 300MV units steel ball coal mill Pulverizing System
Authors: Wang Wenlan , Bai Xionghuai , Liang Wanku
Published: November 2019

Comprehensive treatment,we should have a test on the 300 MV unit steel ball coal mill pulverizing system.At the same time,analyze the main operating parameters before modification.Transform the pulverizing system and optimize the run mode of the pulverizing system by comprehensive treatment.So we can control the pulverizing unit consumption under 30KWh/t.It makes the pulverizing system in the best state.Then we can ensure its economic and safe operation.
Prediction model of blast furnace molten iron temperature based on GRA-DE-KELM
Authors: Hu Kaifei , Hu Qinghe , Liu Guangyue , Zhang Shuang
Published: November 2019

Aiming at the inherent defects of the traditional blast furnace temperature model, a prediction model of blast furnace molten iron temperature based on GRA-DE-KELM is proposed. Because the blast furnace ironmaking process is extremely complex and has the characteristics of multivariable, nonlinear, and strong coupling, the traditional modeling method cannot meet the requirements of high precision prediction of molten iron temperature. Firstly, because the parameters affecting the temperature of molten iron have strong correlation, in order to reduce the complexity of modeling and improve the performance of the model, it is necessary to extract the main parameters affecting the temperature of molten iron. In this paper, the GRA (gray relation analysis) method is used to analyze the input variables and determine the input variables of the model. Then the KELM (kernel extreme learning machine) prediction model is established by combining the analyzed variables, and DE (differential evolution) algorithm is used to optimize the model kernel parameters. Finally, the model is trained and tested using field-acquired data and compared to traditional predictive models. The results show that the model can quickly and accurately predict the molten iron temperature, and has a good guiding significance for the actual regulation of blast furnace temperature.
Robust L2-L∞ Filtering for LPV Systems with Distributed Delays
Authors: Li Yanhui , Fan Zhe
Published: November 2019

The linear parameter-varying(LPV) systems with distributed delays are studied by the robust filter design problem. Firstly, the parameter-dependent Lyapunov theory is used to propose the L
2-L
∞ performance criterion of time-delay correlation. Introducing the projection to understand the coupling between the Lyapunov parameter matrix and the system parameter matrix, and obtaining the L
2-L
∞ performance criterion which is easier to solve. Then the sufficient conditions for the existence of the filter are obtained. The parameterized linear matrix inequality(PLMIs) with infinite dimension is converted to LMIs with finite dimension by using approximate basis function and network technology. Finally, the feasibility of this method is verified by numerical simulation.
Functional Surface Reasoning Strategies in Product Growth Design
Authors: Ning Ma , Bo Yang , Junzhi Shang , Changqing Gao
Published: November 2019

Based on the systematic analysis on the principles of conceptual design, the key technologies of functional surface reasoning in product growth design are discussed. Firstly, the basic concept of product growth design, functional surface as well as Generalized Positioning Principle (GPP) are given. Secondly, the functional design principles based on function surface reasoning are proposed, in which three reasoning rules on relationships among functional surfaces are developed. Thirdly, by transferring the product motion into its relative mechanical transmission, functional-surfaces relationship reasoning strategies are put forward based on kinematic joints. Those methods offer good analyses and descriptions of the orderly evolution process of the product function and structure, in a proper sequence from functional requirements to functional models, then to product motion transmission chain, finally to functional surface pairs constructing the product motion transmission chain. Finally, an example is given to verify the effectiveness of the proposed method.
Enhance the Mechanical Strength of Metal Plates by Processing the Shape of the Bulge
Authors: Han Zhiyou , Chen Yongdang
Published: November 2019

The shape change of spherical bulge can affect the mechanical strength of sheet metal parts. The strength contrast experiment between the local bulge plate and the flat plate was designed to analyze the influence and mechanism on mechanical strength from local bulge shape change. The experiment took an approach measuring the combined displacement and stress of each unit on the stressed surface and the central axis under the same thickness and load to compare the difference of mechanical strength. The results show that the bulge plate brings maximum stress and maximum displacement less than 6% of the plate, smaller mean stress and displacement, lower content of strong stress and high deformation unit, and it is more obvious when the load direction is the same as the bulge direction. The method can provide a new idea for enhancing the mechanical strength of components and reducing the amount of material used in equipment manufacturing.
Numerical simulation of supercritical carbon dioxide turbine thermal stress based on multiphysics coupling method
Authors: Wu Jun , Li Yubing , Zhao Zhenxing , Lin Yuansheng , Bai Fan , Wang Wei
Published: November 2019

Supercritical carbon dioxide Brayton cycle has significant advantages such as high efficiency, low cost and small size. Turbine is a key turbomachinery in the supercritical carbon dioxide Brayton cycle system. It works in the harsh environment of high pressure, high speed and high temperature gradient. The huge thermal stress is an important cause of the turbine structure failure. In this paper, the thermal stress analysis is conducted for a supercritical carbon dioxide turbine with an output of 200 kW and a rotational speed of 40,000 rpm. In order to consider the coupling relationship between the temperature field and the structural stress field, the flow-thermal-solid coupling analysis method is applied to calculate the thermal stress of the supercritical carbon dioxide turbine impeller. The results of thermal deformation and thermal stress analysis of the turbine impeller are obtained by the numerical simulation. The high stress region not only appears in the geometrical structure, but also in the region with large temperature gradient. The analysis results show that the maximum equivalent stress appears at the fillet between the turbine impeller and the seal with a value of 324 MPa. This value is less than the yield limit of the material at 500 °C. The turbine impeller structure meets the strength design requirements.
Fatigue Simulation Analysis of Semi-open Thick-walled Cylinder under Cyclic Loading
Authors: Ren Junpeng , Yue Pengfei , Wang Xudong
Published: November 2019

The fatigue of the gun barrel is an important factor affecting the life of the gun barrel. The gun barrel is simplified into a semi-open thick-walled cylindrical container. The stress form and load type are analyzed according to the internal ballistic model of the artillery. The model is set to simulate the initial boundary conditions and load parameters, and the fatigue response of the gun barrel under different cyclic load impacts is compared and analyzed. The results show that the fatigue danger zones of the different load strengths are basically the same, and the load strength has the fatigue life of the gun barrel. The greater the impact, the life of the body under the strong charge load is reduced by 59.81% compared with the life of the positive charge. In the design and test of the gun barrel, the life of the body under the strongest load is used as the evaluation standard.
The Research on the Intergration of Individual Parking Garages into Underground System
Authors: Yang Feng , Zhu Shikun , Du Linheng , Zhang Changdong
Published: November 2019

The current situation of parking system caused by the increase of domestic car ownership rate is analyzed. The advantages and disadvantages of the present mechanical parking garage are introduced. A single import and export in the parking garage will cause congestion and the user will wait for too long. Aiming at the shortage of the existing mechanical parking garage, a new combinable underground parking system is designed which utilizes multiple combinations of parking garages and sets up multiple lifting parking trays. Through analysis, this new underground parking system will greatly improve the space utilization rate and reduce the parking time.
Research on the Application Status and Development Trend of Automatic Control Technology in Industrial Field
Authors: Gao Kang
Published: November 2019

With the growing maturity of automatic control theory, various automatic control systems have found wide applications in the industrial field. Starting with an overview of the current development of automatic control technology, this paper introduces the application of automatic control technology and analyzes its development trend by presenting four typical industrial automation application scenarios, including industrial boiler control, control of thermal power plants, electronic automatic assembly and intelligent control of temperature.
Dynamic path planning based on variable step size rolling window derivation and obstacle prediction
Authors: Liu Bo , Wang Xiaoping , Zhou Wen , Zhou Wei , Chang Yipeng , Cai Qiang
Published: November 2019

Aiming at the problem of dynamic path planning for UAVs in complex environment, a path planning algorithm combining dynamic obstacle trajectory estimation and variable step rolling window deduction is proposed. When the dynamic obstacle distance is close to the UAV, the Kalman filter is used to estimate the dynamic obstacle trajectory. Then the window deduction is performed to judge the track area of the deduction window, so that the algorithm has certain "forward-looking". In turn, the window step size, the flight speed of the drone and the flight direction are changed, and the avoidance of the dynamic obstacle is completed, and the final goal is reached by the rolling plan. The experimental analysis shows that the algorithm can complete the dynamic path planning of UAVs in complex environment in real time.
Study on Force Interaction System of Upper Limb Rehabilitation Robot
Authors: Wang Xiaoming , Yu Hongliu , Li Kejing , Dong Qi , Huang Xiaohai
Published: November 2019

This paper designed a novel human-machine interaction system for a Center-control upper limb rehabilitation robot. This proposed system integrates control system, force interaction system, the graphical user interface and virtual reality system based on motion intention recognition technology, control technology and servo drive technology. Emphasis is placed on the research of force interaction system, which can identify the patient’s motion intention and provide the required torque for rehabilitation training. Two functional tests have been done to verify that the human-machine interaction system of the upper limb rehabilitation robot can safely and effectively complete the assistance function in the active training, and can assist patients with certain muscle strength to complete the active rehabilitation training.
Fracture failure analysis of an escalator driving chain
Authors: Ren Facai , Liu Xiaochang , Liang Xiao , Wu Xinghua
Published: November 2019

The fracture failure causes of an escalator driving chain were analyzed by the optical microscope and scanning electron microscope analysis. The surface decarbonization of the driving chain plate can be observed. From the macro and micro analysis of the fracture surface, the fracture of the driving chain is caused by fatigue.
RESEARCH ON INTELLIGENT TRUNCATION TECHNOLOGY OF SAFETY MARGIN STATE IN POWER OPERATION SYSTEM
Authors: Liu Wei , Hu Pan , Bo Jue , Wang Danni , Sun Junwei
Published: November 2019

The traditional safety margin state technology has low reliability in the case of continuous failure. By analyzing the influence of branch disconnection on node voltage and line load, the fault status events of safety margin components are screened. Then, according to the method of single circuit breaking, the overload circuit of power operation system is judged. And set the setting value of relaying protection, calculate the safety margin of component disconnection, and complete the intelligent truncation technology design of the safety margin state of power operation system. The n-3 fault state space is truncated, and the experimental results show that the intelligent truncation technology of power operation system safety margin state can effectively improve the reliability of the analysis results
RESEARCH ON THE INTELLIGENT RECONSTRUCTION METHOD OF HARMONIC SIGNAL UNDER MULTI-OBJECTIVE FAULT INTERFERENCE
Authors: Yu Kaiji , Yang Pu , Liu Ruiyun
Published: November 2019

At present, most of the research on the intelligent reconstruction of harmonic signal of power grid focuses on the reconstruction of signal. However, many signal processing does not require accurate signal reconstruction. For example, in the problem of harmonic reconstruction of the power grid, if the harmonic signal of the power grid can be detected directly from the intelligent reconstruction data, there is no need to reconstruct the original harmonic signal. In order to use the network harmonic signal reconstruction algorithm to directly extract the required characteristic quantity from the sampling value to complete the signal detection task. Therefore, the research on the intelligent reconstruction method of harmonic signal under multi-objective fault interference is proposed. The sparse degree and reconstruction matrix of harmonic signals of the power grid are determined through the intelligent reconstruction framework of harmonic signals of the power grid, and an algorithm for the reconstruction of harmonic signals of the power grid is proposed to realize the reconstruction of harmonic signals of the power grid. Simulation results show that this method has high precision in detecting harmonic signal and high precision in detecting harmonic signal.