bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on Strengthening Process of Laser Additive Remanufacturing of Mill Housing
Authors: Huo Lijun , Zhang Yong , Qu Xiukun , Tang Rongjiang , Zhang Quanhong 
Published: March 2021

Abstract
Based on the analysis of the wear mechanism of the mill housing, the results show that the main failure forms of the mill housing are corrosion wear and stress wear. Therefore, it is proposed to remanufacture and repair the housing to improve the hardness and impact resistance of the wear part of the housing. In order to strengthen the wear resistance of the wear part of the housing, Fe45+5%WC alloy powder was prepared to strengthen the wear resistance of the worn part of the housing. The sample of the alloy layer was produced by high power semi-conductor laser, the hardness, impact toughness and surface PT were tested, and the microstructure was observed by metallographic and EDS experiments. The results show that the alloy layer has high hardness and wear resistance, and the grains are fine and the alloy layer is metallurgical bonded to the substrate. The 3500mm reversing mill housing was repaired by laser re-manufacturing technology, and it was found that the alloy layer had good bonding and surface hardness was improved, thus strengthening the housing.
A novel silicone rubber key automatic assembly system using placement machine
Authors: Ma Xiaosong , Zhang Yukun , Wu Keye , Tang Changhua , Ming Zihao , Zhong Zhengqi , Wang Hua 
Published: March 2021

Abstract
Silicone rubber key is an on and off component assembled on PCB. However, the assembly of silicone rubber key has been by manual and it is low efficiency and higher labor cost. In order to solve this problem a new assembly method by using the surface mount placement machine is invented. The main improvement of this new products is that human work can be completely replaced. And the advantage of the new invention is that the production line does not need to change for the surface mount assembly. The only change is the placement nozzle which is to suck the component and then assembly the silicone rubber key on the PCB. Furthermore, the newly designed vibration materials loading device is equipped to increase the production rate.
Enhanced the dielectric and tunable properties of Pb0.3Sr0.7TiO3 and (Bi1.5Zn0.5)(Nb0.5Ti1.5)O7 trilayer film through adjusting heat treatment process
Authors: Hou Shuang , Li Xiuneng , Ma Yijian , Tang Jianfu , Wu Xujing 
Published: March 2021

Abstract
Pb0.3Sr0.7TiO3(PST) and Bi1.5Zn0.5Nb0.5Ti1.5O7 (BZNT) thin films were deposited on Pt/Ti/SiO2/Si substrates by Sol-gel and radio frequency (rf) magnetron sputtering, respectively. The dielectric and tunable properties of thin films were investigated as a function of heat treatment processes. It’s found that the heat treatment process at the appropriate temperature and time can be used to obtain a good thin film. The film has the best comprehensive dielectric properties by annealing at 650°C for 45min, the figure of merit (FOM) is 20.1.
Effects of Stone-Wales and vacancy defects in fracture behavior of defective graphene
Authors: Zhang Cheng , Zhou Jiang , Zhang Cheng-Wei , Chen Xiao-Fei 
Published: March 2021

Abstract
Graphene has much higher mechanical strength than other materials, but can be significantly influenced by the vacancy defect or Stone-Wales defect in the lattices. In this paper, we use molecular dynamics simulation to study the effects of vacancy and Stone-Wales defects in fracture behavior of the defective graphene. The results show that the fracture strength of graphene is more sensitive to the vacancy defects than that of Stone-Wales defect. When the defect is located in the center of graphene, the fracture strength of defect graphene is less than that of defect-free graphene. When the defect is far away from the center of graphene, the fracture strength of defect graphene will be enhanced, even greater than that of defect-free graphene. This study may help to understand the properties of graphene with defect, but also show the potential for graphene-based materials in engineering.
MWCNT/Nafion/Lead Ionophore Modified Electrode for The Detection of Trace Pb2+ in Coastal Seawater
Authors: Wang Cong , Qiu Chengjun , Qu Wei , Zhuang Yuan , Ya Fudong , Yan Yirou 
Published: March 2021

Abstract
Lead ions in coastal seawater will be enriched in marine organisms, further to endanger human health, so it is essential to conduct detection with high-sensitivity and high-selectivity for lead ions concentration in seawater. In this paper, multi-walled carbon nanotubes (MWCNT)/Nafion/lead ionophore electrode modification materials have been prepared therefore to obtain modified glassy carbon electrodes by a coating method. In order to define trace levels of Pb2+, differential pulse stripping voltammetry (DPSV) was used. Moreover, the experimental conditions i.e. accumulation potential, concentration, pH, accumulation time were in optimized condition. Thereby, results show that the peak current which was obtained in the range of 3~100 μg·L−1 for Pb2+ have a linear relationship with concentration corresponded, with the detection limits of 1.2 μg·L−1 for Pb2+. The modified electrode was used to determine the Pb2+ content in the coastal seawater of the Maowei Sea, and the recovery rate was between 90.4%~104.7%, which provided a novel approach of detection to define trace Pb2+ in seawater.
Application of Virtual Reality Technology in Oral English Teaching for College English Majors
Authors: Li Xi , Xie Ying 
Published: March 2021

Abstract
The purpose of this paper is to construct the application ideas of oral English Teaching for College English Majors based on virtual reality technology, so that the virtual reality technology can enable the education environment, improve the personalized learning experience, and make the oral teaching of College English major conform to the needs of information age, artificial intelligence era and 5G era.
Weather monitoring system based on STM32 and OneNet Internet of Things platform
Authors: Ji Zhenglin , Bin Ren 
Published: March 2021

Abstract
The weather monitoring system is based on the Internet of things platform, which is used to monitor the computer room and other places with strict requirements on environmental factors (such as temperature and humidity). It is of great significance to study how to obtain external meteorological information and internal environmental factors, to conduct visual design, and to deal with abnormal data alarm. The weather monitoring system designed in this paper USES STM32F103ZET6 as the main control chip, and the atk-esp8266 and SIM800C as the auxiliary module, and USES the tft-lcd LCD module as the display (to achieve the purpose of meteorological visualization), develop in the ‘keil u Vision4’ development environment using the C programming language.
Research on the Decision-making of Processing method of Scrap Iron and Steel on Case-Based Reasoning
Authors: Xiong Yingqing , Liu Yi , Chen Yan 
Published: March 2021

Abstract
Recycling of scrap iron and steel is the key steps to realize the sustainable development of iron and steel industry. Considering the existing processing methods of crap iron and steel are extensive, and the processing depends on the experience of the staff or manual measurement, which is easy to cause resource waste and secondary pollution. Aiming at the difficulty of the processing decision-making of scrap iron and steel, a method of scrap iron and steel processing technology decision-making based on case reasoning is proposed. After analysing the sources and classification of the scrap iron and steel, and combining with the main processing methods, the modular case base is founded. Extracting the key features of scrap iron and steel, and using the entropy weight method and analytic hierarchy process (AHP) to calculate the weight of each characteristic element, the comprehensive similarity of the index of case is calculated to obtain the processing method. The feasibility and effectiveness of the decision method are verified by taking the scrap iron and steel processing of a metal resource company as an example.
Precision Control Technology and Device for Miniature Bearing Assembly
Authors: Li Yingang , Li Fei , Pu Yang , Zhu Haitian , Ma Guocai , Jin Xin 
Published: March 2021

Abstract
The traditional assembly equipment of tension link components has a degree of automation and few types of equipment, which have a greater impact on the assembly quality, assembly accuracy, and assembly efficiency of the linkage mechanism. This article firstly combines the current assembly status of the tension connecting rod components in my country and proposes a high-precision press-fitting method for connecting rods with continuous clamping, alignment, press-fitting, and pre-tightening actions. Secondly, an assembly platform for high-precision automatic press-fitting of tension connecting rods was developed and designed, and the structure design of the high-precision tension connecting rod press-fitting platform and the working principle of each module were explained, including a non-destructive clamping mechanism, a two-degree-of-freedom macro-motion platform, and vision alignment module, and other designs. Then through the assembly force experiment, the distribution of the bearing press-fitting force is obtained. The platform can increase the assembly coaxially of the 10mm inner bearing to within 5μm.
The Features of English Discourse in Mechanical Manufacturing and the Exploration of Translation Strategies
Authors: Zhang Chaofeng 
Published: March 2021

Abstract
The analysis of the English discourse of mechanical manufacturing reveals that it is characterized with the professional vocabulary, concise expression and prominent key points. Exploration of the discourse translation strategy shows that it should retain its professional characteristics, achieve flexible translation connotation and rationalize the logic, further to ensure that the value of the discourse is accurately transmitted, and the English medium can be effectively applied in the field of mechanical manufacturing.
Application of Fuzzy Comprehensive Method and Analytic Hierarchy Process in the Evaluation of Network Security Level Protection Research
Authors: Zhi Wei-Wei , Zhou Xin-Xing , Yang Lei 
Published: March 2021

Abstract
The data center is the country’s key information infrastructure and an important cornerstone for the development of informatization. Only by ensuring the security of the data center can the security of important data or sensitive information of the information system be guaranteed. Data center network security level protection evaluation is an important technique and means to check whether the data center is safe. At present, the traditional methods of graded protection evaluation mainly have the problems of differences in understanding of safety indicators, ambiguity of judgments, uncertainty of judgment intervals, and unreasonable division of evaluation indicator weights. In view of the above problems, this paper proposes a method for evaluating the protection of data center network security levels based on fuzzy synthesis and AHP. This method classifies and divides the evaluation indicators in Isobao 2.0 into specific weights, determines the evaluation interval, and achieves quantitative and standardization., Objective grade protection evaluation method. Finally, the method is used to realize the evaluation of the network security level protection of a data center, and an objective and fair evaluation conclusion is given.
Face verification algorithm based on Angular Margin triplet
Authors: Wang Ning , Meng Tao , Chen Xiaoyong , Yuan Dunlei , Yue Qihong , Liu Xiangqian 
Published: March 2021

Abstract
In recent years, the face recognition algorithm based on CNN mainly focuses on the improvement of loss function. This paper improves the softmax loss function from two aspects: one is to normalize the weight and features of the loss function, the other is to introduce in class cosine similarity judgment on the basis of the original loss function. These improvements eventually make the distribution of features within the class closer and the distance between classes as far as possible. The recognition accuracy and generalization ability of the network are enhanced.
Study of hygroscopic expansion of anode readout boards of gaseous detectors based on FR4
Authors: Bortfeldt J. , Dubinin F. , Iengo P. , Samarati J. , Zhukov K. 
Published: March 2021

Abstract
The problem of hygroscopic expansion of FR4 based large-size PCBs is discussed using the example of Micromegas detector. The readout electrodes of the detector located on the anode printed circuit board assumed to have precise dimensions. During the production and delivery process, the readout PCB is exposed to different temperature and humidity conditions. As a result, the PCB size differs from the nominal one at the moment of assembly of the detector. The problem appears to be relevant for any other large-size gaseous detectors with the readout structure based on FR4.

The swelling of two test PCB samples during water absorption is studied. The size of the samples is 650× 500× 0.5 mm3. Both samples have copper strips on one side. The second side is naked on sample 1 and fully covered with a copper layer on sample 2.

The elongation of the samples from dry conditions to 50% RH is measured. The influence of the copper layers on the absorption rate and the value of equilibrium elongation is discussed. It is shown that elongation of sample 1 follows the Fick's law while the absorption process in sample 2 is more complicated. The coefficient of linear hygroscopic expansion of sample 1 is measured and discussed.
Pathways of climate resilience over the 21st century
Authors: Schleussner Carl-Friedrich , Pfleiderer Peter , Andrijevic Marina , Vogel Martha M , Otto Friederike E L , Seneviratne Sonia I 
Published: March 2021

Abstract
The impacts of climate change are affecting human societies today. In parallel, socio-economic development has increased the capacity of countries around the global to adapt to those impacts although substantial challenges remain. Ongoing climate change will continue to result in a pressure to adapt, while socio-economic development could make it easier to do so. Countries’ effectiveness in fostering climate resilience will depend on the pace of both developments under different socio-economic and emission pathways. Here we assess trajectories of adaptation readiness in comparison with the continued emergence of hot days as a proxy for climate change hazards for different emission and socio-economic pathways over the 21st century. Putting the future evolution of both indices in relation to the observed dynamics over the recent past allows us to provide an assessment of the prospects of future climate resilience building beyond what has been experienced to date. We show that only an inclusive and sustainable stringent mitigation pathway allows for effective climate resilient development over the 21st century. Less inclusive or fossil-fuel driven development will not allow for improvements in resilience building beyond the recent past. Substantial differences emerge already in the 2020s. Our findings underscore the paramount importance of achieving the Paris Agreement goals to enable climate-resilient, sustainable development.
Analytical solution of the SIR-model for the temporal evolution of epidemics: part B. Semi-time case
Authors: Schlickeiser R , Kröger M 
Published: March 2021

Abstract
The earlier analytical analysis (part A) of the susceptible–infectious–recovered (SIR) epidemics model for a constant ratio k of infection to recovery rates is extended here to the semi-time case which is particularly appropriate for modeling the temporal evolution of later (than the first) pandemic waves when a greater population fraction from the first wave has been infected. In the semi-time case the SIR model does not describe the quantities in the past; instead they only hold for times later than the initial time t = 0 of the newly occurring wave. Simple exact and approximative expressions are derived for the final and maximum values of the infected, susceptible and recovered/removed population fractions as well the daily rate and cumulative number of new infections. It is demonstrated that two types of temporal evolution of the daily rate of new infections j(τ) occur depending on the values of k and the initial value of the infected fraction I(0) = η: in the decay case for k ⩾ 1 − 2η the daily rate monotonically decreases at all positive times from its initial maximum value j(0) = η(1 − η). Alternatively, in the peak case for k < 1 − 2η the daily rate attains a maximum at a finite positive time. By comparing the approximated analytical solutions for j(τ) and J(τ) with the exact ones obtained by numerical integration, it is shown that the analytical approximations are accurate within at most only 2.5 percent. It is found that the initial fraction of infected persons sensitively influences the late time dependence of the epidemics, the maximum daily rate and its peak time. Such dependencies do not exist in the earlier investigated all-time case.
Research on the Influence on Briquette Characteristics by Blended Coal Preparation
Authors: Guan Duojiao , Liu Siyu , Tang Meiling , Dong Yingnan 
Published: March 2021

Abstract
The characteristics of briquette were not the simple superpose of the fractional coals, and its character was obviously different with the fractional coals. In this paper the research on the influence of the proportion upon volatile, ignition and heat value was done. The experiment results are of great significance to improve the mix proportion and make the mix proportion more clear and reasonable.
Coordinated allocation method of opportunity constraints for thermal power units considering source load uncertainty
Authors: Guan Duojiao , Liu Siyu , Qian Xiaoyi , Ye Peng 
Published: March 2021

Abstract
Cogeneration units usually adopt the “heat based electricity” as the main operation mode in heating season, which will lead to the shortage of peak load regulation capacity and a large number of wind abandonment in power grid.
Therefore, a stochastic optimal allocation method of thermal power units is proposed for the uncertainty of wind power output and load. The wind power prediction method based on interval discretization is adopted. On this basis, the chance constraint model of thermal power unit based on wind heat complementary and heat storage device configuration is proposed, and the coordinated scheduling solution strategy based on real coded quantum evolution is proposed. Finally, the proposed coordinated scheduling strategy is applied to typical thermal power units to verify its effectiveness.
Research on Emergency Method of Power Cyber-Physics Risk Area
Authors: Gao Feng , Zheng Zhuang , Chen Kun 
Published: March 2021

Abstract
With increasing emphasis on the economics of power system operation, economic costs have gradually become an important issue to be considered in the research of risk emergency methods. Although the above method of removing the load of key nodes can effectively suppress the spread of risks, this method is also accompanied by a large amount of load loss, which causes economic waste. In response to this problem, considering the state and topology of the system risk area, this paper proposes emergency measures for node injection power adjustment and load shedding. At the same time, it comprehensively considers the effects and costs of emergency measures, puts forward economic and safety evaluation indicators, and builds an emergency model for cyber-physical power system risk areas. Finally, the differential evolution algorithm is used to optimize the emergency model, and the emergency method for cyber-physical power system risk areas with the best control effect and the lowest control cost is obtained.
ESPRIT-based fast broadband measurement method
Authors: Wang Kai , Zuo Yue , Wang Xingcai , Li Dianyang , Cao Hanwen 
Published: March 2021

Abstract
As the penetration rate of power electronic devices in the power system is getting higher and higher, the broadband characteristics of electrical quantities are becoming more and more significant, and it has caused new network-related stability problems. The monitoring frequency band range and response speed of power system signals are proposed New requirements. This paper uses the super-resolution characteristics of spatial spectrum estimation to propose a short-time window wide frequency measurement method, and estimates the number of signal frequency components through the kurtosis of the signal singular value, and proposes a method based on ESPRIT. The fast broadband data measurement method has shorter response time and higher resolution for fast-changing broadband signals, and at the same time improves the performance of this method in the case of lower signal-to-noise ratio.
Research on distribution network investment allocation method considering actual demand and investment benefit
Authors: Wang Qian , Wang Ronghua , Wan Mingyong , Du Ying , He Puyu , Chen Jinyong , Du Le 
Published: March 2021

Abstract
under the new situation, improving the quality and efficiency has become an important means to enhance the core competitiveness of power grid enterprises and ensure the steady improvement of business efficiency. Distribution network is an important part of the power grid of power grid enterprises, and the current distribution network investment distribution lacks scientific quantitative basis. Therefore, how to scientifically plan the scale of power grid investment and improve the efficiency and efficiency of power grid investment is the foundation to ensure the safe and stable, efficient and economic operation of power grid, and it is also a practical problem to be solved.
Research and simulation of line overvoltage in HVDC transmission system
Authors: Liu Zifa , Wen Xingya 
Published: March 2021

Abstract
The distribution of heavy load area and resource area is seriously unbalanced in China. HVDC transmission system project with long-distance and large capacity transmission characteristics has practical significance in today’s social development. Firstly, this paper discusses the basic knowledge of over-voltage in DC transmission system and analyzes the formation mechanism of internal overvoltage, and enumerates and analyzes the common overvoltage faults at AC side and DC side. Secondly, the electromagnetic simulation software PSCAD/EMTDC is selected to build the model, and CIGRE HVDC standard control model strategy is adopted in each module. Finally, the simulation analysis is carried out, mainly aiming at the AC bus grounding fault of converter station, and the overvoltage waveform under fault condition is recorded. The over-voltage characteristics of rectifier side and inverter side under AC bus fault of converter station are compared and analyzed, which provides reliable suggestions for overvoltage and insulation coordination in future design projects.