bluuebunny/crossref_metadata_2025_split huggingface dataset:
Combustion behavior of mineral insulating oil with addition of flame retardants
Authors: Huang Ying , Wei Jiaqiang , Yi Jianxing 
Published: July 2020

Abstract
Mineral oil is the most commonly used liquid insulating material in oil-immersed transformer. Improving the fire performance of mineral oil can not only greatly reduce the probability of fire in transformer system, but also reduce the risk of fire. In this paper, the flash point tester, cone calorimeter and thermogravimetric analyzer were used to study and analyze the mineral oil and modified samples. The results show that the fire resistance and thermal performance of the modified insulating oil are improved.
Performance of anaerobic denitrifying upflow anaerobic sludge bed bioreactor (AD-UASB)
Authors: Wang Jundan , Ji Junyuan 
Published: July 2020

Abstract
Nitrate-containing wastewater has a severely negative impact on the ecological environment, and anaerobic denitrification process is promising biotechnology for nitrate-containing wastewater treatment. The nitrogen removal performance of anaerobic denitrifying upflow anaerobic sludge bedbioreactor (AD-UASB) and granular sludge characteristics were investigated. The results showed the maximum nitrogen removal loading rate (NRR) was reached up to 28.6 kg/(m3·d) as nitrogen loading rate (NLR) was 28.8 kg/(m3·d). At the same time, the effluent NO3
−-N concentration and total nitrogen removal efficiency of AD-UASB was 5.09 mg/L and 99.51%, and the effluent NO2
−-N concentration was as low as 10.97mg/L without obvious accumulation. As NLR was elevated to 36 kg/(m3·d), the effluent NO3
−-N and NO2
−-N concentration were sharply increased to 199.62mg/L and 453.13mg/L, respectively, Thus, the denitrifying metabolic pathway was strongly suppressed which further led to the accumulation of NO2
−-N concentration and the collapse of AD-UASB performance. The granular sludge was broken up and washed out from the reactor, and meanwhile, the concentration of MLSS and MLVSS were declined to 55.09g/L and 24.7g/L, respectively. The research can provide a beneficial reference for the anaerobic denitrification biotechnology application in nitrate-containing wastewater treatment.
A study of adsorption of Cu2+ on magnetic β-cyclodextrin pyrolysis products
Authors: Liu Jun-Hong , Liu Ying , Li Jin , Guo Jian-Hua 
Published: July 2020

Abstract
Magnetic β-cyclodextrin pyrolysis products at 500°C were prepared from β-cyclodextrin pyrolysis products as raw materials, and the adsorption performance of magnetic β-cyclodextrin pyrolysis products on Cu2+ was studied by nitrogen nitriding. this study provided a theoretical basis for the preparation of highly effective adsorbents and the prediction of their adsorption performance on Cu2+. The results show that the adsorption behavior of Cu2+ by magnetic β-cyclodextrin pyrolysis products conforms to the pseudo-second-order kinetic equation. The isothermal adsorption curve conforms to the Langmuir equation, and the maximum adsorption capacity is 405.99mg·g−1.
Research on the adsorption of Cr3+ and Cr6+ by the cracked products of β-cyclodextrin
Authors: Li Jin , Liu Junhong , Liu Ying , Guo Jianhua 
Published: July 2020

Abstract
β-cyclodextrin (β-CD) was used as raw material at different temperatures (300°C, 500°C and 700°C) the adsorption properties of β-cyclodextrin on Cr3+ and Cr6+ were researched by kinetic adsorption and isothermal adsorption. The maximum adsorption capacity and adsorption rate of β-cyclodextrin on Cr3+ and Cr6+ were compared, which provided a theoretical basis for the preparation of efficient adsorbents and the prediction of their adsorption properties on Cr3+ and Cr6+. The results show that the adsorption rate of Cr3+ and Cr6+ by β-cyclodextrin cracking products is in accordance with the Quasi First-order Kinetic model. The adsorption rate of Cr3+ by β-CD300 and β-CD500 is the same and higher than that by β-CD700. The adsorption rate of Cr6+ by β-CD300 is faster. The isotherm adsorption curves of Cr3+ and Cr6+ on β-cyclodextrin cracking products are in accordance with the Langmuir equation. The maximum adsorption capacity of Cr3+ is higher than that of Cr6+, and the maximum adsorption capacity of β-CD500 for Cr3+ and Cr6+ is 1151. 77m/g and 440. 78mg/g.
Effect Analysis of Leakage in the Middle Position and Improvement of an O-type 3-position-4-way Directional Valve with the Spool Structure
Authors: Mao Xuyao , Wu Chao , Ding Hongyuan , Li Bin , Liu Yiou 
Published: July 2020

Abstract
Although the middle position of the O-type 3-position-4-way directional valve with the spool structure is not the working position of the valve, the performance of the middle position is also one of the considerations in the system design. The leakage characteristics of the middle position affect the correctness of the final action of the external load. Leakage effects of the middle position on the action of load under 3 common working conditions were analysed. The results showed that the position of the load actuator moved towards the load direction because of the leakage. The larger the leakage, the faster the response, and the faster the moving speed; the different gaps between different valve ports aggravated the previous phenomenon. The use of a pair of pilot-operated check valves in series and a parallel bypass valve at the inlet and outlet of the actuator could effectively improve the actual cut-off effect of the directional valve.
Research on Fault Diagnosis Method of High Voltage Circuit Breaker Based on gray Relational Analysis and D-S Evidence Theory
Authors: Su Yi , Lu Yufeng , Xie Zhibiao , Wang Jialin , Luo Chuansheng 
Published: July 2020

Abstract
In this paper, a high-voltage circuit breaker diagnosis method based on gray correlation analysis and DS evidence theory is proposed for the fault diagnosis of high-voltage circuit breakers. The fault diagnosis calculation results of a high voltage circuit breaks using this method are compared with those using only gray correlation analysis. The comparison result shows that the proposed method has higher accuracy and reliability, and can accurately determine the type of faults occurring in the high-voltage circuit breaker through the monitored characteristic parameters, avoiding more subjective judgments and improving the reliability of the results.
Communication Distance Test of Pulse MWD System for Mining Mud
Authors: Gao Jun , Li Shan , Xu Qian 
Published: July 2020

Abstract
Aiming at the problem of limited communication distance when the current wireline measurement system is applied in directional drilling to realize the advanced detection and control of mine disaster factors, a mine mud pulse measurement-while-drilling (MWD) system has been developed. However, there is no means to verify and detect the communication distance of this new system in production, acceptance and testing. Based on the communication principle of mud pulse MWD system, this paper establishes a communication data model, analyzes the factors affecting the communication distance of this system, and finally, through building a test platform, tests the communication effect of the mine mud pulse MWD system by simulating the communication distance of 3000 meters. The results show that the pulse MWD system can achieve communication while drilling of 3000 meters or longer.
Optimization of the Formulation and Processing Technology of Quinoa Bread by Response Surface Methodology
Authors: Wei Wei , Wang Lihui 
Published: July 2020

Abstract
In order to ensure rich nutrition and diversified taste of bread, quinoa flour is added to provide consumers with a functional healthier bread. Through the single factor and response surface experiments, the production process of the bread was optimized. The optimal formula of quinoa bread was obtained as follows: Quinoa Powder 1%, Yeast Powder 1.00%, and Butter 5.48%. Under the formula, the sensory score of quinoa bread was 95.9.
Study on Model of Fans with Uneven Blade Spacing
Authors: Zhai Shufeng , Xiao Wanyue Hu 
Published: July 2020

Abstract
We established the CFD simulation model of unequal and equidistant blades in the paper, the pneumatic performance of fan was tested and the aerodynamic performance and aerodynamic noise of the model are analyzed. The differences between the simulation data and the experimental data are small, indicating that this simulation model is consistent with the actual situation.
Performance and Application of Virtual Reality Technology (VR) in Digital Protection of Buildings
Authors: Huang Jianfeng , Gao Hua 
Published: July 2020

Abstract
With the rapid development and continuous improvement of computer technology, more and more computer technology has become an indispensable element in social life, especially the emergence of virtual reality technology (VR), which has a very comprehensive digital performance and is involved in all major industries. VR has a very broad prospect. It can be used to perform digital performance through 3d model mode or 2d panoramic picture mode, and it can also be used in many industries through the characteristics of virtual reality technology itself. This paper mainly narrates the architecture and environment of ancient buildings and ancient villages, as well as the digital performance and application of virtual reality technology, to show the trend and number of the arrival of digital era of virtual reality technology in the near future.
Simulation and analysis of seismic response of parallel double-hole tunnel
Authors: Liu Tong , Liu Yan 
Published: July 2020

Abstract
In order to realize the seismic response analysis of the parallel double-hole tunnel, this paper takes the double-hole tunnel of an underground section of shenyang subway as the research object, USES midas-gts to establish a three-dimensional finite element numerical calculation model, and analyzes and discusses its seismic response. The results show that:Under the action of seismic wave, the maximum position of relative displacement of soil is usually at the soil boundary, and the maximum position of relative displacement of tunnel lining is usually at the tunnel entrance. Along the input direction of seismic wave, the maximum relative displacement of the tunnel is greater than the corresponding value of the other two directions.
Development and application of multi servo motor system of environmental monitoring equipment based on DSP control
Authors: Hua Xue-Hui , Ou Wen-Cai 
Published: July 2020

Abstract
This paper provides a solution of synchronous control of 10-way Panasonic A6 servo motor using DSP chip (TMS320F28379D), which can obtain good dynamic performance and motion position control accuracy. The system uses PID control algorithm to realize intelligent control of position and speed of ten servo motors, and uses database to record the dynamic data of speed, time, distance and power of each servo motor. It can be used in the driving device of environmental monitoring equipment.
Analysis of Internal Heat Transfer Characteristics of High voltage Switch Cubicle Heating Fault
Authors: Su Yi , Xie Zhibiao , Li Lu , Lu Yufeng , Wang Jialin 
Published: July 2020

Abstract
The high-voltage Switch Cubicle is an important equipment in the power system, which undertakes the connection function. There are many kinds of components and parts in the cabinet, and there are many connection contacts. It is easy to be affected by the surrounding environment, aging and corrosion and other internal and external factors. Some components and parts in bad working conditions or in abnormal conditions, especially the dynamic and static contacts of components and parts are prone to heating failure. If the heating parts cannot be identified, maintained and disposed in time, the failure probability of the switch cabinet will be greatly increased, the destructive force and influence caused by the failure will be amplified, and finally the stability of the whole power system will be affected, reliability. Based on the structure of the switch cabinet and the characteristics of the heating fault, combined with the theory of heat transfer, this paper analyzes the internal heat transfer characteristics of the heating fault of the switch cabinet, and uses the fluent software to establish a mathematical model for simulation verification, so as to provide a theoretical basis for the diagnosis of the internal heating fault of the cabinet.
Study on Closing Spring Fatigue Characteristics of High Voltage Circuit Breaker
Authors: Su Yi , Lu Yufeng , Xie Zhibiao , Wang Jialin , Luo Chuansheng 
Published: July 2020

Abstract
One of the most causing closing fault of high voltage circuit breaker is closing spring failure. In order to avoid such closing fault, this paper analyzed the relationship between energy of closing spring and its load, as well as the experiment carried out to get the minimum energy when closing. The time-varying static stress relaxation curve of closing spring force was obtained by analogy the real working condition of high voltage circuit breaker which closing spring is compressed for a long time, the operation time-varying dynamic stress relaxation curve of closing spring force was also obtained by carrying mechanical endurance test. In the end, established the model of closing spring storage life and fatigue life, closing spring life prediction and fault early warning of high voltage circuit breaker was then realized.
The Technological Process of Silver Electrode Printing on Touchscreens
Authors: Zhen Wei 
Published: July 2020

Abstract
A new type of metallic screen embedded in the non-metallic screen, with a mesh count of 230-380 mesh/inch and a wire diameter of 19 μm with an opening rate of 39%, is found through the comparative experiment. The screen has high resilience, suitable mesh count and moderate opening rate. This kind of screen can not only ensure the off-screen effect, but also ensure the high resolution of stencil and printing.
Energy Storage State Identification Of Circuit Breaker Based On Fast Extraction Of Interval Feature Of Vibration Signal
Authors: Xia Xiaofei , Lu Yufeng , Su Yi , Yang Jian , Rao Xiajin , Lu Zecheng 
Published: July 2020

Abstract
Aiming at the problems of slow feature extraction and poor real-time diagnosis of some mainstream state identification methods in actual operation, a fast feature extraction method of vibration signal interval is proposed to identify the energy storage state of circuit breaker. Firstly, according to the kurtosis wavelet modulus maxima, the starting point of the energy storage state of the circuit breaker is detected. Then, the signal envelope sum is extracted as the feature vector by marking the obvious range of envelope amplitude difference through KS test, and the feature is filtered and dimensionally reduced by the releiff-sfs method to get the optimal feature subset. At last, the fuzzy c-means clustering (KFCM) is used to pre classify the features to obtain the optimal hyperplane with the least risk, and support vector machine (SVM) is used to establish the training model for state identification. The experimental results show that the energy storage state identification algorithm proposed in this paper only needs 0.2S to extract features on the premise of ensuring the accuracy, which is of great research value for on-line monitoring of circuit breakers.
Review of underwater sound absorption materials
Authors: Dong Jianzhu , Tian Pengyu 
Published: July 2020

Abstract
Underwater sound absorption is becoming more and more important for underwater military equipment. Underwater acoustic stealth technology is constantly developing, we have conducted a research, summary and classification of underwater sound stealth materials. There are mainly four kinds of underwater acoustic stealth materials: porous materials, resonance materials, piezoelectric materials and metamaterials. We also studied the sound stealth mechanism of these materials.
Analysis of the causes of the cracking of the tee joint of the header of the utility boiler
Authors: Xie Liming , Zhang Yanfei , Zhang Xuechao , Lv Lei 
Published: July 2020

Abstract
The butt joint of the high temperature superheater inlet tee of 330MW Unit Boiler in a thermal power plant cracked. The causes of the weld cracking were analyzed by means of macroscopic morphology observation, fracture SEM inspection, microstructure inspection, mechanical property inspection and chemical composition inspection. The results show that a large number of small thermal cracks are formed in the weld due to improper welding process or operation during boiler installation. At the same time, the improper post weld heat treatment of the joint results in the high hardness of the weld, the insufficient toughness reserve and the decrease of the crack growth resistance. During the long-term operation of the boiler, under the combined action of the primary stress caused by the medium pressure in the pipe and the secondary stress caused by the expansion and contraction of the pipe system, the small crystal cracks in the weld continue to expand, which eventually leads to the macro cracks.
Cause Analysis of Leakage in 316L Stainless Steel Heat Exchanger
Authors: Zhang Xuechao , Chen Hao , Zhang Tao , Sun Yunfei 
Published: July 2020

Abstract
A large area of leakage occurred in plate heat exchanger of a power plant. The causes of leakage were analyzed by means of appearance analysis, chemical composition analysis, microstructure detection and energy spectrum analysis. The results show that Cl ion exists in the environment of the leaking heat exchanger, which has strong corrosiveness to austenitic stainless steel. At the same time, there are machining residual stress and internal stress produced by internal medium in the heat exchanger, which lead to stress corrosion and cracking.
Improved accuracy optimal tuning method for hydropower units’ governor controller
Authors: Niasse Mouhamed , Zheng Qi , Xin Ai , Quan Federico Flamenco , Saleem Adeel , Iqbal Atif 
Published: July 2020

Abstract
This paper aims to improve the model of the hydro-turbine system under the effect of water-hammer for frequency-domain studies. It brings out a novel way to overcome the accuracy limitation linked to the simple first and second-order approximations of the gate-turbine transfer function. The proposed study is based on the detailed model of the hydraulic system considering the effects of water compressibility and pipe elasticity. The improved system is controlled using particle-swarm optimization algorithm, which is shown to be very efficient in controlling the overshoot and stability of the system connected to a single machine single load test system. Step response and load disturbance are simulated. Results from our example prove that covering accurately a frequency range from 0 to over 30Hz is easily made when using this method for frequency-domain simulations of hydropower plant load-frequency control.
Simulation study on anti-sliding performance of runway surface gathered water
Authors: Zhang Longsheng , Han Gensheng , Sun Mingzhi , Liu Zhaoxu 
Published: July 2020

Abstract
In order to study the anti-sliding performance of the aircraft on the runway especially for the surface gathered water condition, a finite element method is used to establish a finite element model considered the contact between aircraft tire and road surface. The vertical deformation of tire is analyzed and compared with empirical formula to verify the feasibility of the model. The adhesion coefficient is used as the anti-sliding evaluation index, and the influence of aircraft speed, tire load, tire pressure and water film thickness on the adhesion coefficient is analyzed by model. The specific conclusions are as follows: The adhesion coefficient between the tire and surface decreases with speed increases, increases with the tire load increases, and decreases with the tire pressure increases. The adhesion coefficient decreases with the increase of water film thickness, and when the water film thickness is thin, the adhesion coefficient decreases more obviously with the increase of velocity.
Influence of Vertical Prestressed Tensioning Process on Box Girder Web
Authors: Wang An , Zhang Xiaoyu , Liu Laijun 
Published: July 2020

Abstract
In order to study the effect of vertical prestressing tension timing and sequence on the vertical stress change of concrete box girder webs, an ANSYS finite element model was established with a large-span continuous rigid frame bridge to simulate the different tensioning sequence of the vertical prestressing steel strands. This paper analyzed the reasonable time of vertical prestressed tension, the stress variation of web plate under different ways of vertical prestressed tension, and the influence of secondary vertical prestressed tension on web crack resistance. The vertical compressive stress at the bottom of the adjacent beam section is obviously smaller than that at the middle of the beam section during segmental tensioning, which leads to the problem that the difference between the free end section and the vertical compressive stress at the end of the beam section is large. During the vertical prestressing of the two lagging sections, the vertical normal stress of the web is more uniform. The maximum vertical compressive stress is 2.7% larger than the overall tension, which is 32.3% less than the maximum vertical compressive stress of the segmented tension. In the case of vertical prestress loss in the initial tension, the reasonable use of the secondary tension construction process can significantly increase the cracking load of the beam.
Cause Analysis and Preventive Measures of Cavitation Corrosion of Diesel Engine Exhaust Valve Seat
Authors: Zhang Zhigang , Dong Qingfeng , Lu Jia , Gao Runyu , Yang Fan 
Published: July 2020

Abstract
This paper analyses the formation of cavitation in the exhaust valve seat of marine diesel engine in combination with leakage of the exhaust valve seat. The paper mainly starts from the cooling water system of the diesel engine that affects cavitation. Finally, the paper puts forward some preventive measures of cavitation corrosion.
Properties of modified epoxy matrix composites reinforced by glass fiber
Authors: Chen Jian , Hang Yuwen 
Published: July 2020

Abstract
The glass fiber reinforced epoxy resin matrix composites were prepared by press molding. Experiments show that the bending strength and flexural modulus of the composite are increased by 16.2% and 21.2%, and the interlaminar shear strength is increased by 28%. The fibers of modified resin matrix composites were uniformly arranged and adhesion of the interface was decent through the scanning electron microscope.
Analysis of display whitish problem on a certain reinforced integrated computer
Authors: Zhang Bin , Li Chao 
Published: July 2020

Abstract
Aiming at the problem that the color of the display screen of a certain type of rugged integrated computer is white, the analysis and location are carried out first. By assuming a method to eliminate the problems of the main board, wiring harness and the display itself, the positioning fault exists with the LCD panel. After the test, it was found that the faulty plate was caused by the high contrast of the display control board. After a detailed analysis, the results showed that the connection of low-resistance media caused a short circuit between pins 1 and 3 in interface CN603, which had the same effect as pressing the contrast adjustment shortcut button S1. The contrast of the display control board is continuously increased, so that the display becomes white. The research in this paper enriches the cases of solving practical problems in engineering applications, and provides theoretical support and reference basis for the subsequent solving of similar problems.