bluuebunny/crossref_metadata_2025 huggingface dataset:
Students’ mathematical communication skills through vlog in project-based learning based on the unity of sciences
Authors: Fitriani Ulliya , Rohman Ahmad Aunur
Published: March 2021

This study aims to determine the increase in mathematical communication skills of students of UIN Walisongo Semarang using mathematics teaching materials that apply Project Based Learning through vlogs based on unity of sciences. The importance of mathematical communication skills can help students more easily communicate the results of their mind on mathematical problems through symbols, diagrams, tables, or the other media. Mathematical communication skills make it easier for students as prospective teachers to convey messages in the form of mathematical concepts, principles, and objects. Students who have mathematical communication skills have an easy understanding of the level of understanding the concepts and application of mathematics in everyday life. Mathematical communication skills can be honed through a learning process that involves groups in creating and completing a project. Giving projects in the form of vlogs trains students in communicating and expressing their ideas or truths and can inspire others to do the same on the vlogs that have been made. Project-based learning through vlogs with Islamic values as the implementation of the unity of knowledge can instill a paradigm that all knowledge is one interconnected unit, sourced from the verses of Allah, both qauliyah and kauniyah verses, so that it is getting higher. Owned mathematical knowledge, makes someone who studies mathematics more faith in Allah. The results showed that there was an increase in the mathematical communication skills of mathematics education students by using a project-based learning model through vlogs based on science unity.
Mathematical critical thinking ability: the effect of scale difference on integral
Authors: Romadiastri Y , Saleh M , Saminanto
Published: March 2021

The aim of this research was to examine the effects on students’ critical thinking skills on integral subject when the lecturer presented problems using different scales on the X and Y axis. This type of research is a qualitative descriptive research. The research subjects were 76 mathematics education students who attended Calculus 2 class. In this study, the 76 students were given four questions to solve and then their critical thinking ability scores were sought. Based on this score, 6 people were selected to be interviewed to find out more deeper about how students’ critical thinking skills in various categories. Data were collected through documentation of student’s work, observation, and interviews. The results showed an effect on students, that is, they met almost all indicators of critical thinking skills. In addition, students become more careful and thorough in solving the problems given. The critical thinking skills arises because the problems presented to students are related to several concepts in the previous materials.
The influence of quarted card and virtual laboratory media on students’ critical thinking ability
Authors: Muliawati Dian Iga , Norra Bunga Ihda
Published: March 2021

Excretory System Material requires interesting and effective media in learning to obtain maximum cognitive abilities. The purpose of this research is to determine the effect of the quartet card and virtual laboratory media on students’ critical thinking ability. This research is quantitative research with an experimental method using a non-parametric analysis Sign test. The research design used was the Nonequivalent Control Group Design with a purposive sampling technique. The instrument used was 18 questions pretest and posttest. The results obtained from the average value of the pretest and posttest of the highest critical thinking ability were obtained by the class with the media using the quartet card 24.038, then the class using the virtual laboratory media was 21.043, and the lowest average score was the control class 18.05. Thus, it can be concluded that there is a positive effect of learning with the quartet card and virtual laboratory media on students’ critical thinking ability in the excretory system material.
Linear and non-linear refractive indices in curved space
Authors: Hadi Miftachul , Deta Utama Alan , Husein Andri Sofyan
Published: March 2021

The refractive index and curved space relation is formulated using the Riemann-Christoffel curvature tensor. As a consequence of the fourth rank tensor of the Riemann-Christoffel curvature tensor, we found that the refractive index should be a second rank tensor. The second rank tensor of the refractive index describes a linear optics. It implies naturally that the Riemann-Christoffel curvature tensor is related to the linear optics. In case of a non-linear optics, the refractive index is a sixth rank tensor, if susceptibility is a fourth rank tensor.
Evaluation of several cumulus parameterization schemes for daily rainfall predictions over Palembang City
Authors: Satya O C , Arsali  , Kaban H , Irfan M , Rahmasari K , Monica C , Sari D R , Alensi N , Mandahiling P M
Published: March 2021

The daily rainfall prediction calculated from four Cumulus schemes i.e.: Kain-Fritsch (KF), New Tiedtke (NT), Grell 3D ensemble (G3D), and Betts-Miller-Janjic (BMJ) had been tested for compliance with daily observation data for 90 days (1 Dec 2018 to 28 Feb 2019) from three observer stations in Palembang city: BMKG-Kenten (Kenten), BMKG-SMB2 (SMB2) and Unsri Bukit Besar (UBB). The test results show that the BMJ cumulus scheme provides better suitability for 19 out of 45 unique indicators for rainfall event indicator (REI) groups and for as many as 13 out of 27 unique indicators for rainfall intensity indicator (RII) groups. The four schemes are able to provide the good performance for each on different indicators and stations, however, in general the BMJ scheme gives the best performance in predicting daily rainfall over Palembang city.
Existence and uniqueness of the boussinesq equations for MHD convection
Authors: Tafrikan M , Ghani M
Published: March 2021

This paper is concerned with the Boussinesq-MHD system with constant viscosity, thermal diffusivity, and electrical conductivity. The existence of this Boussinesq-MHD system was estimated by Littlewood-Paley decomposition, Bony’s para product and commutator estimates. Meanwhile, the uniqueness was estimated by Gronwall inequality. In this paper, the space is the optimal Sobolev spaces for the Boussinesq-MHD system.
Investigation of oral malodor prevention by dentifrices as measured by VSC reduction
Authors: Zsiska Marianne , Schneiderman Eva , Jin Yingkun , Farrell Svetlana , Grender Julie
Published: March 2021

The oral malodor reduction efficacy of dentifrices containing stannous fluoride (SnF2) or zinc plus arginine (Zn/Arg) was evaluated using a halimeter to measure volatile sulfur compounds (VSCs) in two randomized, controlled, single-blind, cross-over pilot clinical trials. Study 1 (N = 16) had five 1100 ppm F dentifrices and five treatment periods: negative control (NC): 0.243% sodium fluoride (NaF); SnF2 A: 0.454% SnF2 + pyrophosphate; SnF2 B: 0.454% SnF2 + sodium hexametaphosphate; SnF2 C: 0.454% SnF2 + citrate; and SnF2 D: experimental 0.454% SnF2 with increased bioavailable Sn. Study 2 (N = 16) had four 1450 ppm F dentifrices and four treatment periods: NC: 0.1% NaF + 0.76% sodium monofluorophosphate; Zn/Arg: NaF + zinc + arginine; SnF2 E: 0.454% SnF2 + 0.078% NaF + sodium hexametaphosphate; SnF2 F: 0.454% SnF2 + 0.078% NaF + citrate. Each period took 96 h; baseline (day 0) morning to day 4 morning. Subjects brushed 2x/day with the treatment dentifrice. VSC levels were measured in the morning, prior to morning brushing, on days 0 and 4. Changes in VSC scores from day 0 to day 4 were assessed using a mixed-model analysis of covariance for cross-over studies. In study 1, SnF2 dentifrices B, C and D showed statistically significant reductions (31.3%, 24.8%, 34%, respectively) in VSC scores versus baseline (p < 0.001); the benefits of these treatments versus NC and SnF2 dentifrice A were statistically significant (p ⩽ 0.001). In study 2, SnF2 dentifrices E and F showed statistically significant reductions (31.2%, 22.1%, respectively) in VSC scores versus baseline (p ⩽ 0.010); the benefits of these treatments versus NC and the Zn/Arg dentifrice were statistically significant (p ⩽ 0.035). The Zn/Arg dentifrice showed a significant increase of 35.2% (p < 0.001) in VSC scores versus baseline. These studies demonstrated that SnF2 dentifrices can provide significant oral malodor reductions, but the benefit is formulation dependent. The presence of SnF2 is not sufficient to ensure efficacy. The Zn/Arg dentifrice increased VSC levels, indicating greater malodor.

Clinical Trial Numbers: 20190429 and 20191028
Research on Anti-Interference Screening of On-line Measurement of Battery Ageing under Smart Grid Big Data
Authors: Fan Xinxin , Yan Hongmei
Published: March 2021

By analyzing the traditional operation and maintenance mode of substation batteries, the paper proposes a new remote online maintenance and management system for batteries based on smart grids, which changes the traditional maintenance method of using discharge load meters to check offline battery discharge packs. Single battery online voltage inspection, internal resistance test, and dynamic equalization, as well as battery pack remote online verification discharge and equalization charging, real-time monitoring of battery aging, promote intelligent, efficient, and unmanned maintenance battery status in substations, Provide strong technical and program guarantees.
Numerical study on hydraulic characteristics of improved X-shaped FGP
Authors: Xue Yang , Xu Lingjun , Wang CaiPin
Published: March 2021

The three dimensional numerical simulation was carried out for flood discharge and energy dissipation process of five improved X-shaped FGPs in hydropower project by using coupled Level set and VOF model and RNG k-ε turbulent model. The change laws of flow pattern, water surface profile and velocity distribution of X-shaped FGP and lock chamber were gained. The results of numerical simulation were compared with the model test data and good agreement was found. It validated the numerical simulation method is reliable, It can provide strong references for the design of energy dissipation and shape optimization of practical project, the results from computation can be supplement for experiment.
Research on Multiple Demand Response in Integrated Energy System Containing Power, Gas and Heat
Authors: Zhang Pan , Zhu Haidong , Zhao Jing , Zhang Tingyu , Huang Baole
Published: March 2021

Integrated demand response provides an important direction for realizing the bidirectional-interaction between supply and demand in the integrated energy system. In view of the differences in the time, space, cost and other aspects of users’ demand for multi-energy, a integrated demand response method based on the energy pricing strategy of the integrated energy system is proposed. Firstly, the characteristics of integrated demand response resources are analyzed, and various integrated demand response models are established. Secondly, based on the nodal energy price, considering the energy response potential, and taking the user energy cost as the optimization goal, an energy cost model that takes into account the load change of the user’s integrated demand response is established. Finally, an example is used to analyze the multi-energy load response under the integrated energy system nodal energy price strategy, which is beneficial to promote the rational use of energy by multi-energy users and reduce energy costs.
Construction Crane Detection under Transmission Line Based on Improved Vibe Algorithm
Authors: Li Xinwen , Lu Li
Published: March 2021

In this paper, the moving object detection part of crane’s illegal construction detection under transmission line is studied, and two scenes are simulated. The Visual background extraction (Vibe) algorithm is selected as the moving object detection algorithm used in this paper. For the problems of the algorithm, including ghost phenomenon in detection results and the the presence of falsely detected foreground points under dynamic background, the Vibe algorithm is improved by the reconstructed background model, dynamic radius threshold and connected domain analysis. Results of the experiment show that ghost area in the detection results of the improved Vibe algorithm can quickly disappear, and the number of falsely detected foreground points is significantly reduced. Compared with the original Vibe algorithm, the average value of the comprehensive evaluation index F1 is increased by 5.8%, and the detection effect of moving object is significantly improved.
Design of Photoelectric Amplification Circuit for Laser Fuze
Authors: Zhang Yulong , Guo Yachao , He Guanglin
Published: March 2021

A photodetection system based on the PIN photodetector was proposed in order to amplify the weak narrow pulse echo signals received in the laser fuze without distortion. The circuit model of this photodetection system includes a preamplifier circuit, a main amplifier circuit. Computer simulations were carried out in the MULTISIM and TINA environment, and the gain of the photoelectric amplification circuit was 119.9dB and the bandwidth was 89.46MHz. The simulation results show that the optoelectronic receiving system realizes the low-noise and high-gain broadband application, which meets the designed requirements.
Application Research of Customer Side Integrated Energy Service System Based on Machine Learning
Authors: Luo Yizhao , Zhan Chao , Liu YuLuan , Yu Huang , Li Ronggui
Published: March 2021

With the emergence of Internet, big data, cloud computing, block chain technology and other high-tech technologies, the integrated energy service mode including more clean energy and micro grid technology has quietly begun. This paper defines the connotation and value of integrated energy services, and constructs the theoretical framework of comprehensive energy services evaluation system based on the traditional balanced scorecard. This paper analyzes the current situation of domestic and foreign energy markets and the scope of comprehensive services. Finally, the difficulties and challenges faced by the energy integrated service industry are analyzed, and the after tax internal rate of return is 11.2%, which provides a reference for the transformation of energy enterprises.
Dual Microcomputer Excitation Regulator Data Follow and Fault Switching
Authors: Zhang Zhentao , Yu Meizhen , Wen Zhang , Zhang Lei
Published: March 2021

In this paper, the generator excitation regulator as the control object, studies the data tracking between the dual microcomputer excitation control system and bumpless transfer, in order to ensure the system real-time data tracking, the accuracy of fault detection and quick failover, especially the design of the control system of a redundant hot standby based on double DSP, through the eCAN communication network data through the eCAN network to follow, mailbox function complete dual data tracking, the proper use of the DSP interrupt service subroutine for fault identification, finally using DSP rich software functions of fault alarm and switching. The experimental test of generator excitation regulator of above ideas developed data follow and fault based switching system, operation results show that: the typical faults in the excitation conditions, system data real-time, accurate tracking, disturbance of high fault free switching, system reliability and maintainability improve.
Study on the comprehensive benefit evaluation model of energy storage for the development of clean energy city
Authors: Wang Xiao , Chen Gang , Wang Baolin , Sun Yan
Published: March 2021

The establishment of clean energy based power supply mode is an important direction of urban energy development in China. The realization of clean energy structure depends on large-scale energy storage technology, so reasonable evaluation of energy storage construction for the development of clean energy city has important practical significance. Under this background, this paper designs the comprehensive benefit index evaluation system of energy storage considering three dimensions of social benefit, economic benefit and environmental benefit; Secondly, TOPSIS evaluation method based on entropy weight method is used to build a comprehensive evaluation model of energy storage for clean energy city development; At last, Taking Urumqi City as an example, the validity of the model is verified.
Research on Urban Clean Energy System Evolution Model Based on Grey Theory
Authors: Lu Yingwei , Gu Ming , Bai Xiaolei , Wei Geran
Published: March 2021

Energy is an important factor of restricting environmental problems. In order to achieve energy transformation, improve energy utilization efficiency and establish a power supply model based on clean energy, vigorously develop clean energy is an important direction of domestic energy development. This paper constructs a multi-energy load prediction model based on grey GM (1, 1) for urumqi clean energy system and calculates the urumqi as an example of the proposed model. On the one hand, this paper can verify the effectiveness of the model for this problem, on the other hand, this paper can obtain the power generation, power consumption of the whole society, typical daily wind, light output curve and typical daily load curve of urumqi during the “14th and 5th” period, so as to provide references for further local energy planning.
First-principles study on the geometric, electronic and thermodynamic properties of the CsPbI3 (001) surfaces
Authors: Yang Kun , Zhang Yikun , Lu Haotian
Published: March 2021

The structural, electronic and energetic properties of the cubic perovskite CsPbI3 (001) surfaces are studied using first-principles calculations. Two types of terminations (CsI- and PbI2-terminated surfaces) are investigated. Our calculations suggest that the PbI2 termination is smoother than the CsI termination. The surface stability analysis indicates that the CsI-terminated surface is more energetically stable. The band gaps of the CsI and PbI2 terminations are determined to be 1.664 and 1.452 eV, respectively, which are larger than that of the CsPbI3 bulk.
Application of Local Materials in the Renovation Design of Local Buildings
Authors: Wu Chuntao
Published: March 2021

In the process of urbanization, the gradual loss of the characteristics of traditional villages caused by the destruction of environmental resources calls for the attention to return to pursue the essence of traditional village architecture as well as traditional building renovation and environmental coordination. Through the study of the characteristics, craftsmanship and aesthetics of the local materials, the transformation and design of the local buildings with the theory of oriental design are used to show the coexistence of the local customs, architectural characteristics and natural environment. Through the experimental study on the application of local materials in this paper, the design strategy of local materials for the transformation of traditional buildings is summarized to protect and inherit Chinese local buildings, which has a deep developmental significance to the transformation and application architectures in future.
Discussion on Short-Term Dynamic Economic Dispatch of Renewable Energy High Penetration Power Grid
Authors: Xu He
Published: March 2021

Before the widespread use of alternative energy sources, economic dispatch only included traditional thermal power units, which needed to consume a large amount of non-renewable energy and produce polluting emissions such as carbon, sulfur and nitrogen. In the current situation of increasingly serious energy crisis, wind energy has become an important representative of new energy. However, wind energy is difficult to predict, so that the output power of wind turbines cannot be dispatched and distributed as expected, and the intermittent and random nature of wind energy will also bring security and stability threats to the entire grid after large-capacity wind power is connected to the grid. Therefore, it is necessary to study a reasonable short-term economic dispatching energy saving plan including wind farms. Therefore, in-depth analysis of the coordination and interaction mechanism between high-penetration distributed power sources and other dispatching resources, and discussion of reasonable optimal dispatching methods are of great significance for promoting the consumption of high-penetration distributed renewable energy and improving the safe and economic operation of the power grid.
Experimental Study on Heat Distribution of High-Voltage Cable Terminals under Operating Conditions
Authors: Xu Minhu , Guo Yun , Zhang Kexin , Zhang Hang , Shang Shulei , Zhao Xiangyu
Published: March 2021

The insulation failure of the outdoor terminal of the high-voltage cross-linked polyethylene (XLPE) cable has a significant impact on the operation stability of the power grid. Effective evaluation of its thermal state is of great significance to predicting its insulation failure. The paper uses infrared thermal imaging to analyse the thermal field distribution characteristics of the outdoor terminal surface under different ambient temperatures. Test results, theoretical calculations and simulation results all show that the thermal steady-state temperature of the inner and outer layers of the sheath shows a non-linear increase with the increase of the current carrying capacity of the cable, which verifies the correctness of the model, so this model can be used to predict And analyse the temperature distribution of the actual 10kV cable cold shrink terminal at the thermal steady state.
Research on Planning and Optimal Operation of Variable Speed Pumped Storage
Authors: Yao Weiwei , Deng Changhong
Published: March 2021

Combining hydropower market economy and safe dispatching, the paper puts forward a mathematical model for optimal dispatching of variable-speed hydropower generating units, and an online transaction mode that takes into account energy saving and consumption reduction. The power generation sequencing method is determined according to the unit quotation method, and energy consumption indicators are introduced according to reservoir storage. Water volume, etc., adopt a differentiated power plan, open power generation rights trading, and adjust the trading market to ensure the economic benefits of hydropower plants while achieving the goals of energy conservation and environmental protection.
Comparative Study of Chinese and Foreign Ship Power Systems
Authors: Zhang Huachao , Luan Fengkai
Published: March 2021

With the current further exploration of the ocean by mankind, the shipbuilding industry is also receiving greater attention, and the shipbuilding industry needs to carry out deeper structural optimization and technological innovation. As the core of the ship, the ship power system is directly linked to the upper and lower limits of the entire ship. The pros and cons of the power system technology not only relates to the operation of the entire ship, but also directly affects the sustainability, reliability and stability of the ship. This article discusses and researches the ship power system at home and abroad, and analyzes the current development trend of the ship industry power system.
Investigation and Research on the Status Quo of Informatization Development at Home and Abroad
Authors: Zhang Huachao , Xu Haoyuan
Published: March 2021

With the further advancement of the digital age, informatization has become the current most mainstream trend and has attracted widespread attention from the public. As a decisive measure for the country to increase its talent pool and cultivate innovative talents, it plays a vital role in promoting national development and enhancing international competitiveness. This article draws on the strategic measures and policies of French education informatization to analyze the current situation of education informatization in China and look forward to the prospects of the education informatization industry.
Fabrication of MnSn(OH)6@MoS2 Core-Shell Nanostructure with Excellent Supercapacitive Performance
Authors: Lu Qixiao , Kumar Sachin , Chen Tingxuan , Zhu Ling
Published: March 2021

Three-dimensional (3D) core-shell structure of MnSn(OH)6 nanobox with MoS2 nanosheet is grown by series of simple steps for supercapacitor application. This core-shell is composited of MnSn(OH)6 nanobox as core and MoS2 nanosheet as shell. As-synthesized electrode material was characterized by Field emission scanning electron microscope (FESEM), energy dispersive spectroscopy (EDS) and transmission electron microscope (TEM). As-fabricated MnSn(OH)6@MoS2 electrode exhibited redox behavior with excellent specific capacitance of 1176 F g−1 at a current density of 4 A cm−2. These findings make MnSn(OH)6@MoS2 a better alternative source for energy storage devices.
Applicability Evaluation of Noise Reduction Materials in Substation
Authors: Hu Sheng , Chen Wei , Zhao Ruidun , Lu Ling , Cao Hao , Peng Jiwen
Published: March 2021

The noise reduction materials of substation need to meet the practicability, technology maturity, economic reliability, security and other factors. Based on the preliminary establishment of the evaluation index system for the applicability of noise reduction materials, this project uses analytic hierarchy process to determine the weight of the evaluation factors at all levels of the index system by using the rationality of the evaluation index system, the relative importance of the evaluation factors (weights) and the rationality of the assignment method. The applicability evaluation model of substation noise reduction materials is established.
The Role and Effects of Thermal Radiation on the Non-equilibrium Heat Transfer in a Porous Filled Enclosure
Authors: Chen Yiwei , Chen Yuanyuan , Xu Xuecheng
Published: March 2021

In this paper, the temperature differential between the solid and liquid phases in considering of combined conduction-convection-radiation heat transfer in porous media is investigated. Simultaneous solution of the solid and fluid energy equations encompasses local thermal nonequilibrium, with volumetric radiative heat flux needed in the solid-phase energy equation. The two energy equations together with the radiative heat transfer equation are simultaneously solved using the Chebyshev spectral method. The influences of the Planck numbers, the optical thicknesses, the scattering albedos, and the emissivities of the bounding walls on the thermal behavior are investigated. The results show that: (1) When Pl increases above 20, the effect of radiation on the flow and thermal field can be ignored. (2) Changing ⌖L
has a significant effect on the solid phase temperature while, the effect is little on the fluid phase temperature. (3) For ω = 1.0, the distribution of θS
− θf
seems to be centrally symmetric. (4) θS
− θf
are always positive except for εW
= 1.0.
The Knowledge Graph of Chinese Cadre Education and Training Research--Based on the Bibliometric Analysis of CSSCI Sources from 2001 to 2020
Authors: Zhang Tian , Huang Xin , Liu Ping , Fu Quanbao
Published: March 2021

Cadre education and training is a leading, basic, and strategic project for the construction of the cadre team, providing strong leadership and cadre team guarantee for party building and national development in all periods. In the past 20 years, fruitful results have been achieved in research in related fields of education and training of Chinese cadre. This paper analyses 308 CSSCI papers with the help of Citespace software and found that the existing research focuses on three aspects: the history of cadre education, the improvement of the effect of cadre education and training, and the strategy of cadre education and training. It is found that the correlation between the research topics is insufficient, the research results are relatively independent, and the quantitative analysis results are insufficient. It is concluded that research on the theory of cadre education and training, research on policies of cadre education and training, and research on the construction of the cadre education and training system with Chinese characteristics in the new era should be the focus of the next cadre education and training research.
Application of Carbon fiber-reinforced plastic composite material in automotive bumper
Authors: Liu Yiheng
Published: March 2021

The emission problem of these traditional gasoline vehicles has become more and more serious. To reduce emission, an important method is to reduce the weight of the car. In this study, a standard model of a vehicle bumper is used to conduct the experiment on lightweight bumper design. The material simulated in the model of the bumper is CFRP material. The angle of each laminate of CFRP material and the layout of the laminate structure contains six layers are modeled in Hypermesh software. Then CFRO material is used to replace the traditional aluminum and reduce the weight of the front bumper component.
A finite-element method for analysing solid expansion process and supervising material selection
Authors: Wang Zhixing , Li Xiucheng , Zhang Hesong , Shang Chengjia , Wang Xuemin
Published: March 2021

Solid expansion technology is regarded as one of the revolutionary technologies that will change the future development of petroleum and gas industry. However, in the process of material selection of expandable tubular, there is always a contradiction between excessive expansion force and insufficient strength of expansion tube, which restricts the application and development of this technology to a great extent. In order to analyze the expansion performance of expansion tubes made of different materials, and the expansion conditions with different friction coefficients, different materials, different expansion cones and rates, finite element models were established by ABAQUS software in this paper to simulate the expansion tubes of several specifications. By comparing the experimental and simulation results, the reliability of the model analysis is demonstrated by the small error range. The influence of material mechanical properties, friction coefficient on expansive force after expansion were analyzed. Moreover, the material selection principle of expandable tubular is also discussed.
Simulation Research on Temperature Field of IN 625 Alloy by Micro-arc Plasma Additive Manufacturing Using Gaussian Heat Source
Authors: Yuan Xiaojing , Guan Xiaohu Chen Ning , Wang Xuping , Guo Xiaohui
Published: March 2021

As a rising star in the field of additive manufacturing, micro plasma additive manufacturing technology has attracted more and more attention because of its unique heat source advantages. However, the simulation method based on micro plasma additive manufacturing technology is not mature enough to reveal the law and guide the experiment. In this paper, the single pass single-layer cladding process of in625 alloy manufactured by micro arc plasma additive is simulated by computer simulation method. The temperature field distribution in the manufacturing process of micro arc plasma additive is studied and the thermal process of characteristic points is output. The results show that: the finite element simulation method can better restore the heat source moving process of micro arc plasma additive manufacturing, and the Gaussian surface heat source has good applicability in the micro arc plasma additive manufacturing. The simulation results can provide theoretical basis and data support for the organizational evolution in the manufacturing process of micro arc plasma additive.
The influence of the development of new energy vehicles on the environment from the game perspective
Authors: Wang Ruiqian
Published: March 2021

In order to alleviate environmental problems such as air pollution, this paper starts from the new energy automobile industry and analyzes the behavior strategies between the government and consumers, two stakeholders of new energy automobiles, through the dynamic game model. The following conclusions can be drawn from the utility function. First, theoretically, the government will not provide any financial subsidies for new-energy vehicles. Second, consumers’ behavioral strategies are influenced by financial subsidies, vehicle purchase taxes, and the utility and cost of purchasing new energy vehicles or traditional vehicles. Therefore, the government should pay attention to the social level in order to achieve the maximum of social utility. On the one hand, the government should enhance the continuity of subsidy policies for consumers who buy new energy vehicles and strengthen the supervision of the implementation of subsidy policies. On the other hand, the government should play a positive role of its own credibility to the public and improve the awareness of environmental protection among car buyers. And consumers should constantly improve the sense of responsibility for environmental protection, so that the two can cooperate with each other and make contributions to environmental protection.
The elasto-plastic analysis of the structure of a main factory building by setting up the isolation device
Authors: Tao Xue
Published: March 2021

The lead damper is a kind of energy dissipating device with stable hysteretic performance, good shock absorption performance and simple structure. To study the lead damper damping effect in the main machine hall, the nonlinear finite element analysis software ABAQUS is adopted to analyze the seismic performance of a main machine hall with lead damper under the action of the rare earthquake and compare the elastic-plastic analysis results under the action of different seismic wave in this paper. The results show the structural seismic performance has been improved significantly, “no collapse under strong earthquake” can be achieved, A successful engineering case was provided for the application of lead damper in the damping design of main machine hall structures.
Prediction of Insulator Pollution Flashover Voltage Based on Data Mining Technology
Authors: Zhou Hongmin , Chen Yutong
Published: March 2021

The pollution flashover of insulators is of great significance to the safe and stable operation of power grids. Therefore, studying the pollution flashover voltage of insulators has very important guiding value for the external insulation prevention of power grids. For this reason, this article has obtained the flashover voltage under different salt densities and gray densities through manual pollution tests. Data mining technology is now widely used. In order to better apply data mining to the insulation flashover voltage prediction,this paper adopts the support vector machine regression method in data mining technology to establish a prediction model to predict the insulator pollution flashover voltage. Through this method, the flashover voltage of the insulator can be predicted in time, which is of great significance for maintaining the safe and stable operation of the power system.
Synthesis and Electrochemical Performances of Iron Oxalate-Multiwalled Carbon Nanotubes Composite Anode for Lithium-ion batteries
Authors: Li Yongjia , Gao Geng , Wang Qianwen , Zhang Keyu , Yao Yaochun
Published: March 2021

Iron oxalate, a widely used anode material in lithium-ion batteries for nearly 10 years, has been developed as promising candidates for anode materials owning to their higher electrochemical reactivity, outstanding cyclability, lower cost and environmental friendliness. In this paper, the iron oxalate-multiwalled carbon nanotubes (FeC2O4@C) composite was successfully synthesized by electrostatic self-assembly technique and the influence of special structure on lithium storage ability was also explored. The results show that the multiwalled carbon nanotubes are embedded inside the rod-like particles of FeC2O4 and also threaded on surface of the multilayer structure. Coupled with excellent structural stability and enhanced Li+ ion diffusion coefficient, FeC2O4@C exhibits suggests superior long-term stability (a reversible specific capacity of 970 mAh g−1 after 50 cycles at 0.5 A g−1) and satisfactory rate capability (824.06 mAh g−1, 770.47 mAh g−1 and 688.60 mAh g−1 at 1, 2, 3 and 5 A g−1, respectively).
Experimental investigation of high-temperature creep properties parameters in 2520 steel
Authors: Wu Hongliang , Zou Haiping , Yu Xiaohong
Published: March 2021

The creep properties parameters of 2520 steel have been investigated by high temperature creep experiments. It shows that the steady-state creep rate of 2520 steel under 700°C (150MPa, 170MPa, 180MPa), 725°C (150MPa, 170MPa, 180MPa), 750°C (150MPa, 170MPa, 180MPa) are 2.34339×10−3 h1, 2.8203×10−3 h1, 3.0559×10−3 h−1, 3.84×10−3 h−1, 8.2678×10−3 h−1, 1.215×10−2 h1, 3.58376×10 h−1, 5.23867×10−2 h−1, 6.48349×10−2 h−1, respectively. The stress index of 2520 steel under 700°C, 725°C, 750°C are 1.459, 6.2866, 3.216, respectively. And the apparent activation energy of 2520 steel is 478.81 kJ/mol. The results of this study can provide some technical references for the safety management of 2520 steel.
Research on Nozzle Flow Field and Performance of Water Ramjet at Large Depth
Authors: Wang Jiawen , Wang Rui , Yao Zhong , Sun Yanhu , Qi Xiaobin
Published: March 2021

For coprecipitating vehicle, water ramjet is an ideal way to reduce drag. In this paper, the performance of water ramjet at large depth and the flow field structure at nozzle are simulated and analyzed. Through the numerical simulation method of underwater Jet flow, this paper studies the development process of flow field at the initial stage and the parameters variation with time of Jet flow in steady state when the working depth is 200meters. The results show that at the beginning of the jet flow, the water blocking effect seriously prevents the development of the gas bubble, and the gas bubble turns over at the nozzle outlet, and expands in length and width. The unsteady process of ‘necking expansion necking’ occurs repeatedly at the nozzle outlet, with the pressure, velocity and temperature change dramatically near the nozzle outlet. When the flow field is fully developed, the pressure, density, flow rate and thrust of the nozzle outlet fluctuate repeatedly with time, and finally tend to a stable value after many oscillations.
Research Status of Oil Water Separation and Oil Absorption Materials -- Visual Analysis of Literature Based on Web of Science Database
Authors: Yang Chenxi , Wang Jian , Zhang Haiou
Published: March 2021

To understand the latest research progress, research trends and future research hotspots of oil-water separation and oil absorption materials for oil spill and oily wastewater at home and abroad, through the web of science core collection database, Based on the literature analysis tools of web of Science (WOS) database, vosviewer visual analysis software and origin, the published literatures on oil-water separation materials and oil absorption materials were quantitatively analyzed in terms of the number of papers published at different times, the top 10 countries (regions), research institutions, research directions, journal sources, etc. The results show that: with the growth of time, the number of papers published gradually increases; China, the United States and India rank the top three, among which China accounts for 40% of the total, indicating that China is in the leading position in this field; among them, Chinese institutions are in the absolute leading position; chemistry, materials and engineering are the most concerned research directions.
Research and Design of Phase Change Energy Storage Water Intake Device
Authors: Liu Zichuan , Cao Xuewei , Zhou Changqing , Yun Hanfang , Liu Zhipeng
Published: March 2021

With the gradual aggravation of desertification, aquatic plants are very rare, rain is scarce, and the air is very dry in desert areas, which poses unprecedented challenges to the survival of local residents. In order to solve the crisis of lack of fresh water, the research on air water intake was carried out, and the corresponding design of air purification device was carried out. The benefit and feasibility of the air purification device were analyzed by using the model and software.
Analysis and Research on Standard System and Technical Requirements of Jib Crane
Authors: Zhao Wei , Ning Weiting
Published: March 2021

Jib crane is one of the most important crane types. It has been widely used in lifting heavy load in ports, shipbuilding, hydropower construction, nuclear power construction, equipment manufacturing, railway, construction and metallurgy industries and so on. China is a leading manufacturer, user and exporter of jib crane, therefore this research will compare, analyze and study the standard system and technical requirements of jib crane between China, other countries or regions as well as international field.
Reduction of Modal Vibration Effect in Load Identification of a Train Bogie Frame
Authors: Ma Shuang , Sun Shouguang , Jin Xincan , Wang Ning , Wang Binjie
Published: March 2021

In order to identify the external applied load on train bogie frame, the load response measured by sensor, e.g. strain gauges, is used in engineering practice. However, it is difficult to model the load-response correlation precisely since the bogie frame system characteristic is complicated, especially, it contains many modal vibration effects. The commonly used linear load-response correlation assumption thus deviates from the truth especially at resonant frequencies. A new approach to reduce the modal vibration effect from the load response based on single degree of freedom assumption is proposed in this article. The approach is applied on real measurement of Beijing Subway train bogie frame and the reduction performance is verified.
Distributed Photovoltaic Short-Term Power Prediction Based On Genetic Algorithm Optimized BP Neural Network
Authors: Zhou Baili , Yan Dandan , Xiong Lianying , Li Yumei , Zhang Yufan
Published: March 2021

With the rapid development of the world economy, energy demand is increasing.Photovoltaic power generation has the advantages of green, environmental protection and renewable, and the proportion of photovoltaic power generation, a new reusable clean energy in the power generation system, has shown a steady increase;However, the power output of photovoltaic power generation systems is affected by many factors, presenting a high degree of uncertainty and volatility, which brings high difficulties to the large-scale grid-connected operation of photovoltaic power generation.Aiming at the shortcomings of existing photovoltaic power generation forecasting, this paper builds a photovoltaic power station power prediction model based on genetic algorithm and BP neural network algorithm, and uses photovoltaic power station operation examples to verify the validity of the model.By using the global search capability of genetic algorithm to optimize the initial weights and thresholds of BP neural network, the prediction accuracy of photovoltaic power generation is improved, which can provide a reference for photovoltaic power generation prediction engineering practice.
RETRACTED: Stability analysis of distributed smart grid based on machine learning
Authors: Li Chenghan
Published: March 2021

Decentralized Smart Grid (DSG) is a new technology proposed to power networks with elastic nodes. It can realize dynamic electricity price demand response without large-scale transformation of the infrastructure.In order to analyze the system stability of DSG, six representative machine learning classification models were applied to analyze the stability data of 10,000 samples of the 4-node system. Combined with the requirements of power system security, stability and economic performance, the effect of each classification model on the stability prediction of DSG system was tested.The test results showed that the model with a Gaussian kernel basis function kernel support Vector machine (RBF SVM) was suitable for data analysis, with the accuracy up to 97.10% and the F metric up to 0.977.CART decision tree model is suitable for real-time forecasting of power system. Under the requirement of ensuring real-time forecasting, its accuracy can reach 84.90% and F metric can reach 0.882. Its modeling and prediction calculation requirements are only 0.98% and 1.59% of that of RBF SVM model respectively.
Effect of Ni-Cr-Fe powder formulation on performance of porous materials based on Ink-jet Printing technology
Authors: Gu Hai , Sun Jianhua , Zhang Jie , Xu Yuanyuan , Jiang Jie , Li Bin
Published: March 2021

Ni-Cr-Fe porous material has the advantages of high temperature resistance, corrosion resistance and good permeability. It has good application prospect and development value as filtration, sound absorption, energy absorption and biological functional materials. In this paper, Ni-Cr-Fe as the main raw material, and PVP, carbon powder, starch as additives, using In-kjet printing molding process, the proportion of raw materials and additives as different levels of orthogonal experiment, the optimal formula was studied. The optimum combination of parameters was obtained by means of open porosity test, hardness test, compression test and comprehensive factor balance analysis. The results showed that the ratio of Ni-Cr-Fe was 20:50:30, carbon powder was 3%, PVP was 15%, and starch was 0.8%. The technological process of preparing Ni-Cr-Fe porous materials by Ink-jet printing technology is discussed in detail, and the adhesive formula and ink formula suitable for Ni-Cr-Fe powder material are provided, which provides practical proof for the indirect pore forming theory of binder.
Study on forming accuracy of ZrO2 ceramic materials prepared by DLP technology
Authors: Sun Jianhua , Gu Hai , Jiang Jie , Xu Yuanyuan , Li Bin , Zhang Jie
Published: March 2021

DLP technology is one of the 3D printing methods for ceramic materials, and its forming accuracy is affected by the preparation of ceramic slurry, debinding and sintering process. In view of three different slurry preparation methods and solid content, the flow characteristics of slurry were studied. The reasonable debinding and sintering process was formulated, and the debinding and sintering treatment were carried out. The influence of slurry preparation methods on the forming accuracy of green parts and sintered parts was found out. The results show that with the increase of solid content, the viscosity of slurry also increases and the fluidity becomes worse. Increasing milling time and rotating speed can improve the flow characteristics of the slurry with 70% zirconia solid content. The C method can not only increase the solid content of the slurry, but also reduce the shrinkage of the sintered parts and improve the dimensional accuracy of the sintered parts.
Research on Low-Carbon Living Landscape Garden Environment Design under the Concept of Green Environmental Protection
Authors: Deng Guiyan
Published: March 2021

The scientific and reasonable design of garden landscape is one of the important means to solve the problem of environmental pollution, and it is also an important means to promote scientific and reasonable garden design and planning. In-depth and systematic investigation and analysis of current garden planning and design ideas and plans, combined with the current era background, put forward ideas for garden landscape design based on environmental protection. This idea will help improve the planning and design of green and environmentally friendly ecological gardens, build a healthy life with energy saving and emission reduction, and guide the healthy development of cities. The thesis focuses on the application of low-carbon concepts in modern urban landscape ecology, and specifically points out a variety of landscape design methods.