bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Process Parameters on Structure and Mechanical Properties of Friction Stir Welding Joint of 5052 Aluminum Alloy
Authors: Zhou Zejie , Huang Zhichao 
Published: August 2019

Abstract
2.5 mm thick sheets of AA5052 were welded using friction stir welding technology. The effects of welding speed, rotational speed of pin, length of pin, single-side and double-side welding process on the morphology, microstructure and mechanical properties of welded joints were studied and analyzed. The failure mode was studied. The results show that the joints with good mechanical properties and without welding defects can be welded when the rotational speed of pin is 500-1200r/min and the welding speed is 100-480mm/min. The microstructure of weld nugget is mainly composed of α phase solid solution and β phase particles. The process parameters of friction stir welding have great influence on the static strength of welded joints. The static strength increases with the increasing of rotational speed of pin, however decreases with the increasing of welding speed. The peak load of the double-side welding increases by 30% compared with the single-side welding. The length of pin has little effect on the tensile strength. The tensile fracture of the single-side welding is located in the weld nugget zone, whereas the fracture of double-side welding is located in the base material zone.
Effect of Heat Treatment on the Microstructure and Wear Resistance of NiCrMoV Steel
Authors: Wang Hongxing , Wang Zhangzhong , Xue Yajun , Wang Cangsheng , Lv Zhe , Yue Bao 
Published: August 2019

Abstract
The effect of an applied load within a 50-200 N range, speed of 10-45 mm/s, and sliding of 10-120 min on the wear behavior of a NiCrMoV low alloy steel quenched in air at 1123-1323 K, followed by tempering at 873 K, was investigated. The material’s microstructure was further studied. The wear was measured using a ball-on-disc type wear machine at room temperature under dry sliding conditions. The micromorphology, worn surface and debris were investigated using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results indicate that all the tempered specimens’ microstructure of the NiCrMoV low alloy steel consists of ferrite and carbide and that the grain size increases with an increase in quenching temperature. The friction coefficient and mass loss increased with an increase in the applied load, the sliding speed and time, as well an increase in quenching temperature. The friction coefficient and mass loss significantly increased at a load of 200 N. The worn surface of all the specimens revealed a discontinuous adherent layer. Furthermore, the microstrucure revealed that the specimens underwent a combination of delamination, plastic deformation, fatigue, and oxidation. The wear mechanism involves predominantly adhesion with a mixture mode of abrasive, adhesion, and oxidation.
Morphological Characterization and Chemical Bond Identification of Collagen-coated Native Silk Fibroin Fibers Using Chemical Method
Authors: Lu Yao , Hao Zhixiu 
Published: August 2019

Abstract
Native silk fibroin (SF) fiber has been widely researched as the materials for tissue engineering scaffolds for its robust mechanical properties. Collagen is the main component of extra cellular matrix (ECM) and has remarkable biocompatibility, so it is often utilized to coat native SF scaffolds for improving the cell adhesion. However, there is lack of feasible methodology for coating collagen on the native SF fibers. In this paper we coated collagen on the native SF fibers by creating amide bonds between the carboxyls from native SF and the amino groups from collagen. Morphological characterization (including 3D surface roughness S
q, S
pq and S
vq,) and chemical bond identification (including amide bond and carboxyl) of the native SF and collagen-coated SF fibers were performed. The results indicated the chemical method could integrally coat collagen on native SF fibers. The chemical modification on the surface and collagen concentration had no significant influence on the 3D roughness. The coated and uncoated groups had high similarity in position of characteristic peaks of chemical bonds.
The Evolution of Microstructures and Mechanical Properties of SnAgCu/Cu Weld Interface during Isothermal Aging
Authors: Chen Haiyan , Huang Liyang , Guo Li 
Published: August 2019

Abstract
Based on the model of the diffusion flux ratio of Cu and Sn at the Cu/Cu3Sn/Cu6Sn5/Sn interface, the evolution of microstructures, the behavior of formation and growth of intermetallic compound (IMC) for Sn95.5Ag3.8Cu0.7 solder aged at 150 °C were studied. The nano indentation was applied to measure the hardness and elastic modulus of the IMC. The tensile strength and the low cyclic fatigue properties of the weld joint were also measured. The results showed that the thickness increments of Cu3Sn and Cu6Sn5 phases of IMC are mainly controlled by diffusion mechanism. The growth rates of Cu3Sn and Cu6Sn5 are 7.86×10-19 m2/s and 7.80×10-17 m2/s, respectively. The hardness and elastic modulus of IMC enhance with increasing aging time. For 24h aging time, the microstructure of the Cu6Sn5 keeps scalloped shape and the elastic modulus of IMC layer are similar to the copper substrate, which result in high fatigue resistance of the welded joint and its tensile strength of 69.50 MPa. With the mechanical hardening cumulative effects resulting from aging and cyclic strain, the fatigue performance and tensile strength of the welded joint gradually worse with the further increase of the aging time.
Study on Stress-strain Constitutive Relationship of Super-long-age Plastic Concrete under Triaxial Compression
Authors: Hu Liangming , Zhu Junfu , Jia Xin , Zhang Changhui , Gao Danying 
Published: August 2019

Abstract
The triaxial stress-strain relationship of super long-aged (540d) plastic concrete mixed with clay and bentonite was studied. According to the test, the stress-strain curves of plastic concrete under different confining pressures are obtained. It is found that the stress-strain curves under the lateral confining pressure are basically the same (0.4 MPa, 0.6 MPa), (0.4 MPa, 0.8 MPa), and the slope of the rising section is basically the same. Compared with the peak pressure ratio (0.2 MPa, 0.4 MPa), the lateral confining pressure is larger. In addition, the calculation formula of the peak secant elastic modulus and the triaxial compressive stress-strain relationship in accordance with the lateral pressure of plastic concrete are also proposed. The fourth-order polynomial mathematical model. The establishment of the mathematical model provides a basis for the development of plastic concrete specifications and triaxial compression performance numerical analysis, and further promotes the engineering application of plastic concrete.
Research on Cost-effective New Alloy Cast Iron
Authors: Sun Dong , Zhang Lingfeng , Xiong Yi , Ren Fengzhang 
Published: August 2019

Abstract
Cast iron is the basic material of the manufacturing industry. It has excellent casting processability and good shock absorption and wear resistance, so it is widely used. With the awareness of energy conservation and environmental protection, the defects of low energy and high consumption of traditional materials are gradually revealed. They are gradually being replaced by new alloy cast iron. This paper introduces the latest developments in new alloy cast iron production technology in recent years in detail, involving iron purification, furnace selection, melt ratio, chemical composition control, inoculant type and application, and stress relief annealing. And this paper analyzes the strengthening mechanism of cast iron, puts forward the problems and solutions in the production process, and expounds the development trend of cast iron production technology and the prospect of China’s cast iron industry.
The Synthesis of Magnesium-aluminium Spinel for Catalytic Hydrolysis of Carbonyl Sulphur at the Middle Temperature
Authors: Shangguan Ju , Liu Yanxia , Wang Zexing , Xu Yikun 
Published: August 2019

Abstract
The influences of the physical and chemical properties for the catalyst materials on the hydrolysis catalytic activity of carbonyl sulphur (COS) and the anti-oxygen property will be crucial to removing COS from gas at moderate temperature. The magnesium-aluminium spinel for catalytic hydrolysis of COS was synthesized by the dry mixing of pseudo boehmite with MgO. The performances of the prepared catalyst were characterized by XRD, nitrogen isothermal adsorption (BET), CO2-TPD, and the COS hydrolysis activities were measured in fix-bed reactor with the change of space velocity, temperature, COS concentration and O2. The results showed that the MgAl2O4 synthesized by mixing of pseudo boehmite with MgO and then calcining at 873K is feasible. By comparison with γ-Al2O3 catalyst, the synthesized MgAl2O4 catalyst possesses more pore volume and diameter so as to improve the diffusion rate of reactant and product of COS hydrolysis. MgAl2O4 spinel catalyst showed the better catalytic activity of COS hydrolysis, combining the advantages of γ-Al2O3 and MgO. As a result, MgAl2O4 catalyst in itself not only helps to improve the catalytic activity of COS, but also helps to enhance the anti-oxygen poisoning property.
Development of High-voltage Standard Current Transformer with Three Phases in One Enclosure Based on Shielding and Balanced Winding
Authors: Liu Gang , Ai Bing , Zhang Jiefu , Liu Kun , Xiao Lingyue , Zhang Fuzhou 
Published: August 2019

Abstract
When three-phase testing method is applied to test errors of three-phase combined transformers on site, many testing devices are needed while laboratory space is limited. Therefore, narrowing down the space that testing devices occupied appears to be crucial. This article designed and developed the gas-insulated high-voltage standard current transformer with all three phases in one enclosure. Its characteristics is that double shielding and shielding combined with balancing winding are used separately to restrain the influence of leakage current and magnetic field on the error of standard current transformer. Moreover, the article carried out the effect of leakage current and magnetic field on the error of standard current transformer. The results show that the influence of leakage current on the error of standard current transformer is less than 1/10 of the error limit. The influence of adjacent phase current on standard current transformer is less than 1/10 of the error limit. The high voltage standard current transformer with three phases in one enclosure, designed and developed in this article, is capable of testing errors of 10 kV three-phase combined transformers for measurement on the field with three-phase testing method.
Analysis of Natural Mordant to B. mori Silk Fabrics Dyeing with Tea Extract
Authors: Huang Xiaocui , Liu Chen 
Published: August 2019

Abstract
Tea pigments as biological materials were extracted in this paper. Applications of turmeric and tannic acid during the silk dyeing with tea extract were studied. By changing mordant dyeing methods, concentration of mordant, dye solution pH value and dyeing concentration, we tried to study the effect of natural mordant. The results showed that two kinds of mordant were more suitable for pre-mordant. When the tannic acid was 5 g/L, the turmeric was 0.025 g/L, and the dye solution pH value was 5, the dyeing effect was optimal. Furthermore, when the dyeing concentration was diluted 5 times, the dyed fabric color was fuller. With the optimum mordant dyeing process conditions, the colors fastness to washing were acceptable.
Research on the Multi-factor Aging Resistance for the materials of Composite Poles
Authors: Li Panfeng , Wu Xiong , Feng Bing , Xie Fang 
Published: August 2019

Abstract
A multi-factor faster aging test with 5000h was carried to evaluate the aging resistance of running composite tower materials outdoor, which accelerates aging test includes different factors such as solar aging, mechanical aging, electrical aging, heat aging and environmental aging of materials. The flexural modulus retention rates of resin-based and resin-system composite samples decrease with aging time, except for the sample made of isophthalic unsaturated polyester, the flexural modulus retention rates of other composite samples are above 90%. Meanwhile, the modulus of the unsaturated polyester resin and E44 epoxy resin decreased significantly, the modulus retention of unsaturated polyester rate was 88% after aging test, and the damage flextural strength for E44 epoxy based glass fiber composite sample was 92%, while the bending strengh retention ratioes of other composite materials were higher than 96%. The multi-factor accelerated aging test results show that the modified polyurethane resin and vinyl resin have good aging resistance, and meet the application for composite materials’ poles and crossarms outdoor.
Design of Indoor Position System Based on DWM1000 Modules
Authors: Pan Dawei , Yu Yunhua 
Published: August 2019

Abstract
The traditional indoor position system is realized with laser scanners and cameras. The methods need complex calculation and have poor real-time and high cost. In this paper the UWB position technology is used to realize the indoor position system with TDOA. The platform of position system is based on DWM1000 modules, and the software and hardware are developed independently. The test result shows that the system has good reliability and feasibility and the position accuracy is within ±10cm.
Technical Study on the Rock Wool/Polyurethane Composite Insulation Board and Its External Insulation System for Ultra-low Energy Consumption Buildings
Authors: Lu Guozhong , Zheng Xuesong , Zhang Jiayang 
Published: August 2019

Abstract
Ultra-low energy consumption buildings refer to the buildings which adapt to the climate characteristics and natural conditions, use the envelope structure with high thermal insulation and air tightness performance as well as efficient fresh air heat recovery technology to minimize the heating and cooling demand of buildings, and make full use of renewable energy to provide comfortable indoor environment with less energy consumption. As a key part of the ultra-low energy consumption building technology system, the external wall heat transfer coefficient K value is much higher than the external wall heat transfer coefficient required by the current ordinary energy-saving buildings in China. In order to achieve the thermal insulation performance required by the ultra-low energy consumption buildings, higher requirements are put forward for the thermal insulation materials and external thermal insulation system of building envelope. In this research, a new type of thermal insulation material for external wall of buildings which combines rigid polyurethane and rock wool is developed, and its application technology in ultra-low energy consumption building external wall thermal insulation system is also studied.
Optimization of Technical Parameters of CO2 Inerting Goaf in 7271 Working Face of Yaoqiao Mine
Authors: Cheng Genyin , Liu Yifan , Si Junhong 
Published: August 2019

Abstract
Aiming at the problem of fire prevention and extinguishment in the 7271 working face of Yaoqiao Mine, the carbon dioxide inerting method was used to establish the influencing factors system, which combining injecting pipeline parameters, mining technical parameters and inerting gas physical parameters. Numerical simulation method was used to study the influence of different gas injection depth and different gas injection volume on the distribution of carbon dioxide flow field in the goaf. The range of gas injection parameters is determined by hierarchical simulation experiment; Taking comparative experiment between parameters obtain the optimal carbon dioxide fire prevention and inerting parameters for the 7271 working face to study injection depth and injection volume. Experiments show that the width of the oxidation zone reduced by 56m after inerting the goaf, and the width of the asphyxiation zone increased by 29m.
Reliability Assessment of RIC Neutron Flux Measurement System
Authors: Sun Lingyu , Liu Ce , Zhu Lili 
Published: August 2019

Abstract
Nuclear power core neutron flux measurement system is a special tool for real-time accurate measurement of nuclear reactors, which requires not only high technically demanding, but also has high requirements for reliability. Compared with the advanced level in foreign countries, there is still a certain gap between the reliability and stability of domestically produced products. Taking the prefabricated water level monitoring system as an example, this paper adopts the risk priority number method to carry out the failure mode and impact analysis, and divides the system into various agreements. Level, a detailed analysis of all possible failure modes, causes of failure, severity of consequences, probability of occurrence, and degree of damage. Meanwhile, the reliability prediction model is established to carry out quantitative analysis. According to the fmea result and the reliability prediction model, more serious failure modes and modules with higher failure rate are discussed. Based on this, the design improvement direction of the water level monitoring system of the core operation state monitor is proposed.
Structure and Protective Properties of Ti-containing Organic-inorganic Hybrid Film on Stainless Steel Surface
Authors: Lian Xueting , Gao Jin , Guo Feifei , Li Xiaogang 
Published: August 2019

Abstract
In this paper, a dense structure of Ti-containing organic-inorganic hybrid transparent film was prepared on the surface of 304 stainless steel by sol-gel method combined with organic-inorganic hybridization theory. The basic properties and corrosion resistance of the hybrid film showed a unimodal change with the increase of the precursor content. When the molar ratio of the precursor to tetrabutyl titanate was about 0.75, the hybrid film obtained had the best performance. The microstructure of the film was analyzed by SEM and AFM technology. The Ti-containing organic – inorganic hybrid film was denser than the Si-containing hybrid film and epoxy film, which resulted in better salt spray resistance and EIS performance.
High Resolution Sequence Stratigraphic Division and Isochronous Framework Establishment in Wuerxun-baer Sag
Authors: Wang Qi 
Published: August 2019

Abstract
High-resolution sequence stratigraphy and related technical methods have been widely used in the analysis of complex and changeable continental petroliferous basins in China in recent years. At present, the main fields of oil and gas exploration in Hailaer Basin have been transferred to lithologic reservoirs, so it is very important to find lithologic traps and analyze the favorable formation conditions of lithologic traps. The tectonic evolution, sequence stratigraphic framework and tectonic control over the sedimentary system of Nantun Formation have been studied in depth by predecessors. However, the division accuracy of Nantun Formation can only reach the level of system tract, and the distribution characteristics of sand bodies and source-reservoir allocation under high-resolution sequence framework are seldom studied. Therefore, on the basis of predecessors’research, the author synthetically uses the related technology and methods of high-resolution sequence stratigraphy, and according to the sequence boundary characteristics reflected by drilling, core, seismic and logging data, establishes the high-resolution sequence stratigraphic framework through fine division and correlation of base-level cycles at various levels. The distribution law of sand body under its control and the source-reservoir allocation relationship favorable to lithologic trap formation are studied in order to have important guiding significance for further tapping the potential of lithologic reservoir.
Properties of Gypsum Composites with Straw Fillers
Authors: Regulska K , Repelewicz A 
Published: August 2019

Abstract
Results of tests of physical and mechanical properties of gypsum composites with organic fillers, in the form of cut straw are presented at the paper. The conducted tests aimed at determining the influence of gypsum mixtures composition and the manner of filler’s preparation on the quality of composites. Strength and thermal properties, natural radioactivity and susceptibility to biological corrosion have been examined. The results were interesting. Moreover using straw as a component of gypsum mixtures is particularly friendly for natural environment.
Passive Adaptive Robot Obstacle Analysis and Optimization
Authors: Sun Lingyu , Liu Xiaoya , Li Zhilong 
Published: August 2019

Abstract
In order to improve the obstacle performance of robots in complex terrain environment, a crawler passive adaptive robot is proposed, which is mainly composed of car body module and track module. The link mechanism of the track module has a degree of freedom, and the carbon fiber material has the characteristics of light weight and high rigidity. The obstacle course of the crawler module is introduced, and the mathematical model is established. The obstacle obstacle ability is analyzed. On this basis, the optimization parameters and the objective function are proposed. The rod length parameters of the linkage mechanism are optimized by matlab. The analysis and simulation motion analysis of the optimized linkage mechanism verify the rationality of the obstacle performance and structural parameter design of the robot.
Research on Critical Technical Elements Recognition Method Based on AHP
Authors: Sun Lingyu , Zhu Lili , Liu Ce , Liu Xiaoya , Li Zhilong 
Published: August 2019

Abstract
The assessment of technology-readiness level is widely used in the multi-disciplinary manufacturing field. The identification of critical technical elements is a key step in the assessment of technology-ready level, and it is an important guarantee to reduce risks in the project or product development process and reduce development costs. The identification of traditional critical technical elements generally adopts the expert scoring method. Through discussion, the list of critical technical elements of final consistency is obtained. The results are subjective and uncertain, resulting in the loss or redundancy of critical technical elements, which directly affects the key to technical readiness. Quantitative identification of technical elements. To this end, this paper proposes a method for identifying critical technical elements using the AHP principle. Firstly, the judgment matrix is established according to the criterion and the importance degree scale. The consistency matrix is used to check and adjust the judgment matrix according to the consistency ratio. Then the summation method and the square root method are used to solve the importance of each sub-technical element. Finally, according to the importance degree. Quantitative evaluation results identify critical technical elements and validate their validity by example pairs. The results show that the method combines qualitative analysis with quantitative analysis and has good engineering application value.