bluuebunny/crossref_metadata_2025 huggingface dataset:
Guilin Tourism Image Perception Based on Web Text Analysis
Authors: Zhou Man , Jia Huiying , Yan Zhen
Published: June 2020

Under the background of Guilin Municipal Government’s proposal to build international tourism by 2020, this paper studies Guilin’s tourism destination perception image, and puts forward the development direction of Guilin’s tourism image in the future. In this paper, Octopus is used to customize the text review data from some popular tourism websites. A total of 14094 valid text review data are collected. Firstly, the data collected from Guilin tourism texts are pre-processed to remove duplication, word segmentation, stop words and invalid symbols. Subsequently, we use R to do word frequency statistics, draw word clouds, construct a three-tier Bayesian probability model, and use ROSTCM6 text review data to analyse emotional orientation. The results show that 78% of the tourists hold a positive attitude towards Guilin tourism. The factors affecting tourists experience are mainly divided into four aspects: natural scenery, tourism service, characteristic tourism products and commercialization degree, among which natural scenery is the most important factor. In the last, we put forward corresponding countermeasures from four aspects: increasing the propaganda of scenic spots, intensifying the development of tourism characteristic products, improving the quality of tourism service and strengthening the construction of commercial streets.
Research on Dynamic Characteristics of River Pollution Degradation Coefficient in the Main Stream of Weihe River
Authors: Zhang Haiou
Published: June 2020

In order to reveal the influence of different hydrological conditions and dynamic changes of pollution sources on the degradation coefficient of pollutants, this study took the main stream section of the Weihe River as the research object to analyze and study the dynamic characteristics of the degradation coefficient of pollutants in the river. Taking the dry year as the representative hydrological year, according to the measured data of each section of the Weihe River, the parameter estimation method based on Matlab regression analysis was used to calculate the comprehensive degradation coefficients of CODcr and NH3-N under different hydrological conditions in each section. The simulation verifies and verifies the calculation results. The results show that different comprehensive degradation coefficients of pollutants under different hydrological conditions are more in line with the actual situation of river pollutant degradation.
Analysis and Prevention of Urban River Pollution
Authors: Wang Yibo , Liu Yingxin , Huang Jinming , Wu Tongtong , Huang Jieyun
Published: June 2020

According to the principle of “nearby discharge” of waste-water treatment, with the progress of industry, the amount of pollutants discharged into urban rivers keeps increasing. Under the requirements of limited river pollution and environmental carrying capacity, the pollution situation of urban rivers needs to be explored and the ways of pollution control need to be explored. At present, most of China’s rivers are polluted, and none of the seven major river systems has been spared. The pollution sources of urban rivers include industrial pollution sources, domestic pollution sources, agricultural pollution sources, oil tankers and other pollution sources. The pollutants in urban rivers include organic pollutants, inorganic pollutants, plant nutrients and heavy metals in water. Pollution prevention and control measures of urban rivers: pollution source control, adhere to the income reduction; physical method, chemical method, biology - ecological method. In a water basin of Guangdong province as an example, some indexes because of pollution in urban river “surface water environment quality standard GB 3838-2002” V class level, basic use as mentioned in the measures for prevention and control of pollution of rivers.
The Classification and Characteristics of Black Holes
Authors: Hu Jingfu
Published: June 2020

Scientists have obtained the first image of a black hole, using Event Horizon Telescope observations of the center of the galaxy M87. The image shows a bright ring formed as light bends in the intense gravity around a black hole that is 6.5 billion times more massive than the Sun. It is consistent with what General Relativity predicts. One of the famous predictions of general relativity is that of black holes. With the birth of the first image of a black hole, this article will discuss the classification of blackholes.
Research on Noise of Tractor Cab Based on FE-SEA Method
Authors: Cheng Kexiang , Ma Xintan
Published: June 2020

The mid-frequency noise in a tractor cab is predicted, the FE-SEA hybrid model of tractor cab is established, the cab structure modal density, internal loss factor and coupling loss factor are obtained by theoretical calculation and test method, and the finite element-statistical energy analysis is simulated after loading vibration and noise excitation. Comparing the cab acoustic pressure level obtained by the simulation with the measured data, the analysis and comparison show that the result of the model using FE-SEA hybrid method in the mid-band is highly fitting with the test value, and the prediction absolute error is less than 2dB, which can be used for further analysis.
Research on New Technology of Energy Conservation and Emission Reduction Based on Environmentally Sustainable Buildings
Authors: Gao Yannan
Published: June 2020

With the continuous development of the economy, the world’s attention to environmental sustainability has risen to a new level. During the construction process, especially in the application of energy-saving and emission-reduction technologies, many key technologies for environmental protection must be combined. Organically integrate energy saving and emission reduction with environmental sustainability. All building technology emission reduction technologies must meet environmental protection standards, such as using corresponding technologies to control indoor air pollution from various building decorations, and give corresponding control and treatment. These key technologies require research today. The effectiveness and environmental sustainability of these energy saving and emission reduction technologies are the key research areas of this paper.
Application of river sediments to soil improvement in urban green space
Authors: Niu Yan , Guo Chao
Published: June 2020

At present, there are two main problems in urban green space soils. One is the change of soil properties due to human treading. The other is the invasion of guest soil and solid waste, which leads to poor soil physical status and fertility. A large amount of dredged sediment is generated every year in urban rivers, and if it is not handled properly, it will cause secondary pollution. Since the dredged sediment contains nutrients such as N and P required by plants, the dredged sediment can be applied to the problem of soil improvement in urban green space to achieve an ecological disposal effect.
Development of VCHs Transfer Mechanism and Remediation Technology in Contaminated Sites
Authors: Wei Yulu , Chen Zhiwen
Published: June 2020

In recent years, with the adjustment of China’s economic structure and the acceleration of urbanization, a large number of heavily polluting enterprises are facing shutdown and relocation, the residual volatile chlorinated hydrocarbons (VCHs) in the site become the priority pollutants in soil and groundwater due to the great threat to human body and environment. How to accurately predict the occurrence state and pollution degree of VCHs in the polluted site and put forward reasonable and targeted effective prevention and control strategy has become an international problem to be solved. The remediation technology of volatile chlorinated hydrocarbons (VCHs) in contaminated sites is introduced systematically, which will provide scientific basis for the practical remediation of contaminated sites in the future.
Measurement and Spatio-temporal evolution of China’s Regional Eco-efficiency
Authors: Li Jian , Zhang Yanran
Published: June 2020

Based on panel data from 2008 to 2017, the Super-SBM model that considers undesired output has been to measure the eco-efficiency of 30 provinces in China. Meanwhile, the spatial autocorrelation analysis is incorporated into the spatiotemporal evolution law in order to calculate the global and local Moran’s I index, and combining the Moran scatter plot to explore the spatiotemporal evolution and agglomeration characteristics of regional eco-efficiency. The results show that the overall level of China’s eco-efficiency has improved, but the regional differences are obvious, shows a gradient descending pattern of “East, Northeast, Middle and West”. The regions with familiar eco-efficiency level showed the volatility clustering phenomenon, and that the regions and their neighbors have potentially similar trends. Eco-efficiency in China was improved followed by the improvement of local polarization situation and regional differences have narrowed.
Research on the Status Quo of China’s Shipping Economy Development and Enterprise Transformation Strategy
Authors: Wang Yiqi , Song Shuxian
Published: June 2020

With the decline of the world economy, the world shipping market is facing a series of crises such as the reduction of supply, and these crises are also the dilemma faced by Chinese shipping companies. Through the analysis of the important index BDI of the international shipping market, this paper realizes the trend of the international shipping market since the crisis of financial integration, and based on this, forecasts the international shipping market. At the same time, we analyze the important index of China’s shipping industry, China’s coastal bulk freight index (CCBFI) and China’s export container freight index (CCFI), which gives us a clearer understanding of the domestic and international shipping market situation. The business model is already suitable for the current shipping market and has reached the edge of change. Finally, based on market analysis, this paper analyzes the advantages and disadvantages of China’s shipping companies, and puts forward targeted development and transformation opinions on the disadvantages.
Analysis on the Critical Speed of Drilling String in Deep Water without Riser
Authors: Fang Yong , Qian Liqin , He Yuhang , Chen Kun , Huang Zhuang , Zhan Yueming , Wang Xudong , Xia Hongwei
Published: June 2020

According to logging data of the field, while drilling in the deep water without riser, rules of motion and stress distribution of drilling string is really complicated without the constraint of riser because of the comprehensive action of working load, environmental load, movement of platform, whirl of drilling string and so on. Especially with the increase of water depth, the drill string will vibrate severely when the speed reaches the critical value, which easily causes the dynamic failure of the drill string. Based on rotor dynamics theory, this paper has established the mechanics calculation model of nonlinear support drill string without riser to analyze the influences of bearing stiffness, water depth and section size of drill string on critical speed of drilling string. The result shows that critical speed of whirl of drilling string is decreased with the increase of wall thickness; critical speed of whirl of drilling string is decreased with the increase of the length of string in water; critical speed of whirl of drilling string is increased with the increase of the stiffness of bearing. According to the results, reasonable speed of drilling string has been given to prevent resonance. The results can be used as reference for deepwater drilling operations without riser.
Optimization of aerobic composting process of Camallia oleifera Seed Cake and its fertilizer efficiency
Authors: Hu Hualin , Li Guanqiang , Song Junrong , Wei Fuxiao , Sun Chao , Wang Hong
Published: June 2020

[Objective] In order to promote the development of camellia oil processing enterprises and solve the problem of waste of camellia oil enterprises, Camallia oleifera cake that tea saponin has been removed was composted to form organic fertilizer. [Method] The D-optimal mixture design method was utilized and the seed germinate rate was defined as evaluation index. The optimized formula was obtained by establishing regression equation and response surface optimization analysis based on single factor experiments. [Results] Under the condition that fermentation bacteria agent was 1% of the mixture, the best composting process was: 74.8% of remove tea saponin of Camallia oleifera cake (dry), 12.5% of pig manure (dry), 8.0% of straw and 4.7% of rice husk. Its seed germination rate predicted value was 150.56%, which was basically consistent with the measured value 151.23%; Its total nutrient content was 5.17%, which was up to organic fertilizer standard (NY525-2012). [Conclusion] The optimized formula can be used as composting process of Camallia oleifera cake, which has good repeatability, and provide scientific basis for rational utilization of Camallia oleifera cake and development of organic fertilizer.
Isotope Geochemistry of the Shimensi Deposit, Northern Jiangxi and Its Analysis
Authors: Ye Zhanghuang , Wang Peng
Published: June 2020

The Shimensi deposit is located in the Lower Yangtze metallogenic province. It is a recently-discovered world-class tungsten-polymetallic deposit, accompanied by Cu and Mo. The orebodies are thick with gentle dipping, mainly distributed along the contact zone between the Cretaceous porphyritic biotite granite and the Neoproterozoic biotite granodiorite. The mineralization was closely linked with the zoned hydrothermal alteration, including silicification, greisenization, chloritization, carbonatization and K-feldsparization. Based on ore geology and C, H, O isotope, this paper has studied the origin and evolution of the ore-forming fluids. The δ13CV-PDB values of calcite range from -10.26‰ to -3.26‰, with an average of -7.3‰, indicating that hydrothermal fluids from which calcites precipitated were derived from the granitic magma. The H and O isotopic compositions of the quartz veins (δ18DSMOW=- 106‰ to -86‰, δ18
OSMOW(H2O)=2.2‰ to 4.5‰) suggest that the ore-forming fluids mainly had a magmatic-hydrothermal origin, but to some extents, mixed with meteoric water. The subduction of the Paleo-Pacific Plate beneath the Eurasian Plate resulted in lithospheric thickening and subsequent delamination, and the main N-S stress field in East China changed progressively to an E-W orientation during 170-135Ma. Maximal lithospheric thinning happened in the Late Mesozoic, which led to the direct contact between the crust and asthenospheric mantle. Consequently the heating from the asthenosphere on the crust trigged and widespread development of extensional structures, the intensive magmatism and mineralization in eastern China in Mesozoic. The isotopic chemistry indicates that the ore mineralization in the Shimensi deposit was closely linked with Early Cretaceous magmatism in East China.
Research on the Algorithm of Online Route Re-planning for UAV Formation
Authors: Bi Tianshu , Ye Ping , Xu Yunong
Published: June 2020

In order to solve the real-time and robust problem of online flight path re-planning when UAV encounters new threat sources in the course of navigation, an online flight route re-planning algorithm based on sparse A* algorithm is proposed. Based on the threat model of UAV, the online route re-planning strategy is analyzed. When the UAV detects a new threat in the course of navigation, according to the current position of the UAV formation and the position of the threat source, a route that can safely bypass the threat source is quickly re-planned. In order to meet the requirements of real-time and robustness, the node expansion and update strategy of the improved sparse A* algorithm and the hierarchical planning combined with the size step size are adopted. The simulation system of UAV formation navigation is established to verify the process of online route re-planning. The number of expansion nodes and convergence time of algorithm before and after the improvement are compared, and the track accuracy of fine planning based on rough planning is compared. The experimental results show that the improved algorithm can speed up the search speed and meet the real-time requirements of online route re-planning.
Analysis and Simulation of Spiral Waste Plastic Electromagnetic Cracking Reactor
Authors: Li Zhihua , Song Yingshuai , Zhao Xianbing , Hu Lihao , Su Xin
Published: June 2020

Domestic garbage contains a lot of waste plastic. Due to the stable physical and chemical structure, it may not be decomposed in the natural environment for tens to hundreds of years, so the waste plastics cause serious pollution and harm to the environment. Using electromagnetic heating technology and double-helical propulsion structure, Continuous and efficient cracking of waste plastics rector can produce useful oil, cracking gas and carbon black to achieve the purpose of high value recycling of waste plastics.
Research on Stock Prediction Model Based on Deep Learning
Authors: Zhang Haiying , Liang Qiaomei , Li Siheng , Wang Rongqi , Wu Qingqiang
Published: June 2020

In order to obtain stable returns, this paper aims to establish a quantitative model with higher prediction accuracy. According to the time series characteristics of financial data, the prediction model with financial time series data is constructed by using the time-memory sequence model LSTM, which is applied to the representative SSE 50 series stocks. And based on this, the LSTM model with Encoder-Decoder mode and a hybridized framework of LSTM with CNN are built to improve the original model. Feature extraction is performed on the input data by using CNN, and then as an input to the LSTM, the extracted features are used for sequence prediction with the LSTM model.
Construction of Life Cycle Assessment Model of Carbon Emission in Hui Cultural Tourism Destination——Taking Huangshan City as an Example
Authors: Mi Xue , Zhao Lei , Ding Nan
Published: June 2020

Tourists travel behaviours generate tourism waste, consume carbon energy, and emit carbon dioxide. To estimate and evaluate the carbon emissions and ecological environment of tourism destinations can provide data support for local tourism sustainable development programs. Considering the characteristics of the integration of Huangshan City’s Hui culture and ecological environment, a life cycle assessment model of carbon emissions from Hui culture tourism destinations is established. According to the model, this paper proposes that increasing more activities in the scenic spot, managing carbon emission of enterprises related to scenic spot, and promoting the concept of green consumption.
Study on Functional Components of Functional Food Based on Food Vitamins
Authors: Xiao Surong , Li Jingdong
Published: June 2020

The research and development of functional food ingredients of food vitamins are gradually moving towards serialization, nutrition, functionalization and standardization, and more and more high-tech applications in this area. In addition to rich basic nutrients (i.e. proteins, fats, sugars, vitamins and minerals), food also contains a wide range of bioactive substances, such as polyphenol compounds, organic sulfur compounds, phytoestrogen terpenoids, etc. At present, the research on functional ingredients of these food sources has become a hot research field in the international academic circle. This paper discusses the meaning of functional foods and their functional ingredients, and expounds the synthesis and extraction of vitamin E. At the same time, the function of compound food fiber in functional food was introduced.
Research on the Effect of Glutamine Transaminase on the Gel Properties of Mutton
Authors: Guo Yanan
Published: June 2020

Glutamine transaminase is an enzyme that can catalyse the formation of valence bonds between the ε-amino group of lysine and the γ-hydroxylamide group of glutamic acid, resulting in the polymerization of chime. In this paper, the sources, properties, mechanism of action and application of glutamine transaminase in lamb meat processing are described in combination with existing literatures. The bioavailability of its products is discussed. The results show that: glutamine transaminase, treatment the effects of temperature and reaction time on the cooking loss rate and characteristics of mutton gel are significant. The effects of glutamine transaminase, processing temperature and gellan gum on the properties of mutton gel are significant (P <0.05); temperature on glutamine transaminase There was significant interaction effect on the gel properties of mutton emulsion (P <0.05), but each factor had no significant interaction effect on the gel properties.
The Comprehensive Evaluation Method of the Human Factors in the Flight Deck Based on the Physical and Behaviour Measurements
Authors: Zhang Jiong , Wang Zhen , Lu Yanyu
Published: June 2020

There is increasing concern about the design and evaluation of the human factors in the flight deck. The study was to propose a comprehensive evaluation method of the human factors in the flight deck, combing with multiple physiological signals. The proposed comprehensive evaluation method in the flight deck are composed with the evaluation of the operators’ cognition, operational performance, control activities and workload. The cardiovascular signal, eye movement and flight parameters were recorded during task to conduct the evaluation. An experiment about the evaluation of the display elements in the flight deck was conducted to verify the proposed comprehensive method of the human factors. The results revealed the validity of the proposed method, which can give a detailed description of the operator’s workload, operational performance and cognition during the flight task.
Magnetic Drug-loaded Microcapsules Intergrating Photo thermal and Targeted Therapy
Authors: Han Yu , Gao Ying , Shan Xiaoqian
Published: June 2020

Compared with single chemotherapy, collaborative treatment can significantly improve the cure rate of malignant tumors, reduce the use of chemotherapy drugs and avoid the damage to the organs. The combination of Photo thermal therapy and chemotherapy has also become the most common treatment in recent years. In this article, we synthesized a kind of mesoporous silica with a large specific surface area and pore volume to encapsulate the Fe3O4 nanoparticles. Owing to the unique magnetic and photo thermal properties of Fe3O4 nanoparticles, the combination of PTT- chemo targeted therapy has been achieved and greatly reduces the side effects of the drugs on the human body. This novel particle will create a broader application in the future.
Research on the Value of the Basic Principles of Marxism Based on Constructivism in the New Period
Authors: Ge Chuanguang
Published: June 2020

Marxism is the product of the times, which originates from profound economic and social roots, ideological sources and practical basis. The practical, revolutionary, scientific and open features of Marxism determine its timeless value. Today’s adherence to and development of Marxism in China are the mission of the Party, the needs of the country’s development and the expectations of the people’s life. Based on constructivism, this paper analyzes the connotation of the basic principles of Marxism, fully understands its development significance, and analyzes the value of Marxism in the new era from several aspects.
Design of Fault Diagnosis System Based on Fuzzy Inference for a New Type Equipment
Authors: Wang Xin , Cui He , Ji Lu , Li Yun
Published: June 2020

Aimed at the puzzle of non-bijection between cause and symptom of the fault for a new type equipment system, the paper built the mathematical model of fuzzy inference by means of inference mecha- nism of fuzzy relation. In the paper, it designed the overall scheme of fault diagnosis system, and realized the function of system fault diagnosis by means of VC + + programming language according to the diagnosis flow of system. Through actual example validation, it shows that it satisfies the accuracy of fault diagnosis for a new type equipment system. The fault diagnosis of weapon equipment has always been an important topic for military research. With the change of war mode, higher requirements have been put forward for weapon equipment support technology. A new type of equipment is widely used in the land war, so some faults also appear one after another. In the long-term research, it is found that there is a fuzzy relationship between these fault phenomena and the causes. A fault does not correspond to a fault cause in modern mathematics, fuzzy mathematics can clarify the relationship between fault symptoms and fault causes in the equipment system. In this paper, the fuzzy fault diagnosis method is used to build a general fault diagnosis system to realize the fast and accurate analysis and diagnosis of faults.
Numerical Study of Hydrodynamic Performance of a Hydrofoil with Vibration Trailing Edge
Authors: Xu Yingbo , Tang Denghai
Published: June 2020

In order to study the influence of trailing edge vibration to the hydrodynamic performance of hydrofoil, the large eddy simulation and moving wall boundary condition methods were used to simulate the flow field of NACA66-mod hydrofoil with different trailing edge vibration amplitude(VA) and frequency. First, the numerical simulation methods are verified by comparing with experimental data. Then the flow field of hydrofoil was simulated to study the influence of vibration frequency and amplitude to hydrodynamic performance. The result shows that the vibration amplitude and frequency has significantly influence on the trailing edge vortex shedding. The intensity of the vortex increases rapidly with the vibration amplitude increasing. The lift and drag coefficients are influenced by the vibration amplitude and frequency.
Rating-Based Collaborative Filtering Using Spectral Clustering Algorithm
Authors: Yan Yongjie , Xie Hui , Ma Li
Published: June 2020

Clustering analysis has been an important area of machine learning and data mining research, it can help us know the connection between things more clearly. In recent years, the research of spectral clustering algorithm has been a new and efficient clustering analysis algorithm. In this paper, the sparsity and the real-time problem of traditional recommendation algorithms, a new recommendation algorithm based on spectral clustering is proposed. The spectral clustering process can improve the efficiency of spectral clustering algorithm. Spectral clustering can be performed offline, which will accelerate the speed of online recommendation. The experimental results on Movie lens show that the new algorithm improves recommendation quality in MAE and coverage.
Isolation and Characterization of Lipid-Producing Bacillus sp. TC14
Authors: Zheng Chaocheng
Published: June 2020

In order to obtain microbes producing microbial oil from environment, a strain, marked as TC14 was isolated by replica plating and Sudan Black staining on the selected media. Its colony is smooth; milk white, slightly transparent, round edge, sticky. Its cell is long-rod, G-, intracellular lipid granule. The results of physiological and biochemical research: catalase, denitrification and fluorescent pigment tests are negative; metachromatic granule staining, amylolysis, lecithinase tests are positive. According to its sequencing result of 16S rDNA, strain TC14 is classified and belonged to Bacillus, namely sp. TC14. The optimum inoculation temperature is 35°C and the most suitable initial pH value is 10. The intracellular lipid of strain TC14 is extracted by the way of hydrochloric acid hydrolysis and the calculated ratio of oil-production is 5.08%.
Characteristics of Splash Formed by the Impact of Liquid Jet on a Thin Liquid Film
Authors: Kang Tianyu , Qin Qin , Yao Xin , Yu Qingbo
Published: June 2020

For rotary cup granulation, the splash may occur during liquid slag falls onto the cup, which increases the risk of operation. By performing experiments for three liquids with different properties, including water, 95% ethanol and 30% glycerol-water solution, the characteristics of splash formed by the impact of liquid jet on a thin liquid film were studied. The experimental results showed that increasing the impact velocity and diameter leaded to intense splash, while increasing the viscosity and the surface tension reduced the scale of the splash.
Preparation and Performance of Binary Copper-Cobalt Based Catalyst Used for Low Temperature Selective Catalytic Reduction of NOX
Authors: Yang Hezhi , Li Zhiyuan , Tao Yong , Shang Xiangjing , Yu Qingbo
Published: June 2020

Low-temperature urea-SCR technology is a new type of low temperature denitration technology, which could achieve the removal of NOX in low temperature (50–100°C) flue gas, and avoid the ammonia escape problem of traditional NH3-SCR technology. In this paper, a series of binary Cu-Co based composite catalysts with different Cu-Co loading ratios (0.1: 0.9–0.9: 0.1) were prepared at calcination temperatures of 300–600°C, and their preparation parameters were optimized. The experimental results showed that when the calcination temperature was 500°C and the Cu-Co loading ratio was 0.9: 0.1, the Cu-Co-based binary catalyst had the highest low-temperature denitration performance. Finally, the XRD analysis of the phase composition for the Cu0.9Co0.1/NUAC catalyst was carried out in this paper.
Analysis of bioactive compounds and antioxidant capacities in different varieties of carrots
Authors: Ma Jie , Chen Chunyan , Ma Jun , Ma Wei , Yang Jiao
Published: June 2020

In this study, twelve varieties of carrots with five colors were evaluated for their levels of bioactive compounds and antioxidant capacities. Bioactive compound contents and antioxidant capacity levels were significantly different among distinct varieties. In detail, ascorbic acid contents ranged from 0.30 mg g−1DW to 0.63 mg g−1 DW, carotenoid contents ranged from 0.06 mg g−1DW to 0.54 mg g−1DW, anthocyanin contents ranged from 0.03 mg g−1DW to 6.18 mg g−1DW, proanthocyanidin contents ranged from 0.36 mg g−1DW to 1.34 mg g−1DW, flavonoid contents ranged from 1.07 mg g−1DW to 6.01 mg g−1DW, total phenolics contents ranged from 7.25 mg g−1DW to 33.25 mg g−1DW, FRAP levels ranged from 0.02 mg g−1 DW to 0.16 mg g−1DW, and ABTS levels ranged from 23.13% to 75.97%. Moreover, the highest contents of anthocyanin, proanthocyanidin, flavonoid, and total phenolics, as well as antioxidant capacity levels, all were in Tianzi (purple). While the highest contents of ascorbic acid and carotenoid were in Zishenghuang (yellow) and Zishengzi (purple with orange core), respectively. This information could be a valuable asset in the research and extension of carrots.
The Effect of Journal Misalignment on the Lubrication Performance of Partially Textured Journal Bearing with Elastic Deformation
Authors: Song Xintao , Wu Wei
Published: June 2020

In order to analyse the effects of journal misalignment and elastic deformation on the lubrication performance of partially textured journal bearing, an elastic-hydrodynamic lubrication (EHL) model was specifically established based on the steady-state Reynolds equation. Through numerical calculation, the effects of elastic deformation, degree of misalignment and misalignment angle on load capacity and overturning moment were investigated. The results show that when the degree of misalignment is large, the elastic deformation cannot be ignored. With the increase of degree of misalignment, the load capacity and overturning moment are increased. With the increase of misalignment angle, the bearing performance variations are complicated. When the misalignment angle is equal to 90°, there are two pressure peaks in the film pressure. The load capacity is the lowest, and overturning moment is the largest. The optimized partial texturing is still beneficial to the performances of bearing when journal becomes misaligned, which is attributed to the additional hydrodynamic lift.
Design and Control of Pneumatic Muscle-Driven Robot Arm Based on Bilateral Rehabilitation Training
Authors: Jiang Chi
Published: June 2020

As a new treatment method, the upper limb rehabilitation training robot can help stroke hemiplegic patients recover their upper limb motor function by providing repetitive exercises and other ways. In this paper, based on the background of bilateral rehabilitation training with pneumatic muscle-driven robot arm containing paw system, the key technology of benevolence is systematically studied, and a set of experimental system is designed to verify the research results in detail. The mechanism design of the humanoid multi-joint double-arm is completed by imitating the human arm. Pneumatic artificial muscles are used to drive the shoulder and elbow joints of the mechanical arm, and stepping motors are used to drive auxiliary motion joints. The designed mechanical arm has both flexibility and compactness in structure. This study provides a useful reference for improving the effectiveness of arm design of upper limb rehabilitation pneumatic muscle-driven robot, and is helpful to broaden the research ideas of upper limb rehabilitation robot.
An overview of impact resistance of auxetic lattice structure
Authors: Huang Xiufeng , Zhang Zhenhua , Wu Jihang
Published: June 2020

Auxetic materials have many advantages in strength and energy absorption, which have become a research focus of scholars at home and abroad. It’s of great significance to ship protection structure design that researching deeply on auxetic lattice structures. According to the unique properties of auxetic lattice structures, this paper mainly introduces the research status of the impact resistance mechanical properties of the new structure. The research status of low-speed impact, high-speed projectile impact, and explosion impact in the auxetic lattice structures is described from three aspects: theoretical, experimental and simulation studies. The research status of in-plane impact at medium and low velocities, explosive impact and projectile penetration is expounded. The effects of geometric parameters and impact velocity on deformation modes and energy absorption of structures are also analyzed. Finally, summarize the article and point out the contents in the future.
Application of Visual Simulation Technology Based on the Virtools Method in Equipment Virtual Maintenance
Authors: Wang Xin , Wang Yibo , Meng Xianggang
Published: June 2020

In this paper, 3dsmax is used to build three-dimensional model of scene and virtual equipment. Virtools is used to edit various maintenance scenes and build a virtual maintenance system consistent with the actual environment. According to the operator’s action instructions, the system shows the real-time human-computer interaction process, the state change of the model, the scene response process after the operation, which makes the virtual environment and the real installation operation consistent, and realizes the virtual maintenance training of the equipment. The virtual maintenance training system can be applied to the maintenance training in Colleges and universities, so as to reduce the loss of real equipment and improve the efficiency of equipment use.
Anti-school Bullying System Based on Voiceprint Recognition
Authors: Yu Hao
Published: June 2020

The article is devoted to the study of an Anti-school Bullying system based on Voiceprint Recognition. Through the introduction of the social background of the phenomenon of bullying and the existing relevant technological background, the design of an Anti-school Bullying system based on Voiceprint Recognition technology is introduced, and the analysis of the system is made.
Analysis of Damage and Crack Propagation in Unidirectional Composite Laminates with a Peridynamic Model
Authors: Shen Rulin , Xiong Rui , Gong Yanling
Published: June 2020

A continuous function was applied to establish a peridynamics model to study the damage of unidirectional composite laminate, a kind of transverse isotropic material with three-dimensional (3D) structure. To express the interaction of nonadjacent layers and the influence of thickness on elastic deformation and damage, this paper employed a spherical material horizon. The spherical harmonics function was applied to express the relationship of the micro-elastic modulus and the bond-fiber angle, as well as critical bond stretch and the bond-fiber angle, respectively. Spatial stress or strain conditions were employed to calculate the strain energy density and solve the bond stiffness constant. The model was verified with unidirectional multilayer composite laminate with orifice. The damage mode and the crack propagation process of laminates with orifice were also consistent with that of experimental.
Study on Surface Flashover Characteristics in SF6/CF4 Mixture
Authors: Zhai Zhixuan , Hua Yue , Xue Yuchen , Yang Songhan , Zhang Lei , Li Bo , Lin Yuan , Su Yang , Hao Wenfeng , Hu Yang , Wang Qinghao
Published: June 2020

Surface flashover characteristic of epoxy resin composite material in SF6/CF4 mix gas were studied through experimental method, and the influence of several key parameters were analyzed, such as gas pressure, SF6 mix ratio and voltage polarity. It is shown that, when the mix ratio of SF6 in the mixed gas is 40%, the flashover voltage of epoxy resin insulator can reach over 60% of the flashover voltage in SF6 with the same pressure. The synergistic effects in the needle-plate electrodes system have significant difference between positive and negative polarity. The synergistic effect for negative polarity is weaker than that in negative polarity. Comprehensive environmental requirements and surface flashover characteristics, the results provide a potential SF6 alternative for GIS equipment.
Simulation of Hot Stamping Process Based on Deform Software
Authors: Huang He , Lu Yuansan
Published: June 2020

Taking the U-shaped part of 22MnB5 ultra-high-strength steel as an example, a finite element model of hot stamping was established. The DEFORMV11.0 software was used to simulate the deformation process and the temperature field distribution of the sheet during hot forming. The results show that the temperature of the sheet varies with the different locations in the hot stamping process. The side wall of the sheet cools faster. Meanwhile, the temperature changes in the different positions of the concave mold and the convex mold are not uniform. The temperature change of the punch with the largest contact with the sheet is more obvious.
Research on the Application and Development Trend of Automation in Mechanical Manufacturing
Authors: Yin Jiankai , Yang Jianan , Huang Jingru
Published: June 2020

With the development of science and technology, automation is increasingly used in industrial production, which has greatly improved production efficiency. Based on this, this article studies the application and development trend of automation in mechanical manufacturing. First of all, automation was summarized, its concept, basic characteristics and development status were introduced, and then the application of automation technology in machinery manufacturing was analyzed, including application principles and practical applications. Next, we explained the development trend of automation in the field of machinery manufacturing, and then several problems in the current development were explained, and finally we put forward corresponding suggestions based on the above analysis. The application of automation technology has great advantages in cost control and improving the core competitiveness of the market. To ensure its long-term development, we must attach importance to the introduction of new technologies and the optimization of production quality.
Preparation and Characterization of a New Composite Adsorption Materials Composed of Two Activated Alumina and Microporous Molecular Sieve and Its Adsorption Property to Water
Authors: Zhang Haoyue , Wang Yongquan , Zhang Zhongbin , Niu Baolian
Published: June 2020

In order to improve the comprehensive performance of solid adsorption desiccant for compressed air adsorption dryer and reduce the loss rate of adsorption dryer, a new type of binary composite solid adsorption material suitable for compressed air drying is put forward. This material is composed of activated alumina (matrix) and 4A molecular sieve and 13X molecular sieve respectively in the proportions of 95%/5%, 90%/10% and 85%/15%. Static characteristic analysis is first made on three macro characteristic parameters, including the compressive strength, specific surface area and static water adsorption (60%RH). Thereafter, microscopic surface morphology analysis on composite material samples are employed. Comparative analysis result shows that, for compressed air drying, the activated alumina/13x molecular sieve with the proportion of 85%/15% is better than the 90%/10% activated alumina/4A molecular sieve composite solid adsorption material.
Lightweight Drill Pipe Based on Composite Carbon Fiber Material
Authors: Jiang Keyue , Xie Ruiheng , Yun Hanfang
Published: June 2020

At present, our country’s drilling platforms mainly use alloy high-speed shafts. Due to the long transmission torque of drill pipes, drill collars and so on, the drill pipes are subjected to excessive torque and torque during operation, which often lead to fracture failure. The working environment of the drill pipe is wet underground, which is easy to corrode due to chemical reaction with the surrounding environment, thus causing the strength of the high-speed shaft to reduce and corrode, accelerating the fracture of the drill pipe, causing a large amount of waste of engineering materials and causing more serious environmental pollution problems. Based on the defects of the metal main shaft mentioned above, carbon fiber material is used as the main material of the high-speed shaft to avoid the corrosion of the main shaft caused by the changeable environment during drilling operation. Meanwhile, it has higher compressive strength, torsional strength and high temperature resistance. The invention can reduce the cost of transportation and installation parts, consume less electric energy during operation, reduce the weight of the drilling platform itself, and reduce a large amount of unnecessary cost in the drilling industry.
Effect of Spinning Process Parameters on the Forming Quality of Inner and Outer Teeth Shaped Parts
Authors: Wu Minhui , Xu Xiao , Xia Qinxiang , Cheng Xiuquan
Published: June 2020

Deform-3d software was used to conduct numerical simulation on the spinning forming process of inner and outer teeth to study the strain distribution and material flow law during the spinning forming process. The influence of mandrel rotation speed and roller feed speed on the forming quality of inner and outer teeth profile was studied. The results show that the best forming quality of the spinning parts can be obtained under the combination of the process parameters of the mandrel rotation speed of 150r/min and the roller feed speed of 110mm/min. Compared with the experimental results, the maximum relative errors of inner and outer teeth wall thickness were 2.03% and 1.78%, which verified the reliability of the finite element model. The results can provide guidance for the finite element simulation and production of inner and outer teeth spinning forming process.
Study on the support performance of portal support under different confining pressure
Authors: Song Jiaqi , Dong An
Published: June 2020

In this paper, a certain section and hydraulic support of Hongyang No.3 coal mine are taken as the research object. The numerical model of coupling between the tunnel and hydraulic support is established by using the finite element software ABAQUS. The Mises stress of the tunnel and support under different confining pressure is analyzed. The results show that: Under different confining pressure, the maximum Mises stress appears at the arch foot of the tunnel, with the increase of confining pressure, the Mises stress at the arch foot is rising, and the increase of Mises stress at the left arch foot is greater than that at the right arch foot. The uneven stress of the tunnel increases, and the tunnel is more prone to damage. With the increase of the confining pressure, the Mises stress of the middle pillar of the portal support decreases continuously. The load is mainly borne by the columns on both sides. The middle pillar cannot play its bearing capacity, which is not conducive to the support of the tunnel.
Measurement of oxide layer thickness on 7050 aluminum alloy surface based on image processing technology
Authors: Zhang Maolin , Cai Song , Huo Yongqing , Chen Zhiren , Wu Zhilin
Published: June 2020

This paper presents a method for measuring the thickness of the oxide layer on the surface of 7050 aluminum alloy based on image processing technology. As the 7050 aluminum alloy is oxidized to different degrees at different temperatures and different holding times, its surface color will also change significantly with the degree of oxidation. The image processing method was used to obtain the gray value of the sample photos with different degrees of oxidation, and the surface oxide layer of the sample was subjected to Ar+ layer-by-layer sputter peeling. XPS analysis was performed on the peeled surface to calculate the thickness of the oxide layer. The oxidation was found. Relationship between layer thickness and gray value. The thickness of the oxide layer can be obtained by extracting the gray value of the surface of the test object. This measurement method has the advantages of low cost, non-contact, reliable measurement, convenient and fast.
Process parameters optimization of single-track laser cladding for 45 steel gear remanufacturing
Authors: Yu Tianbiao , Shi Bowen , Song Boxue
Published: June 2020

In order to research the optimal combination of process parameters for the remanufacturing of 45 steel gear with RCF104 alloy powder, three-factor and five-level orthogonal experiments of laser power, scanning speed and powder feeding speed were carried out on 45 steel substrate. The best process parameters combination was selected by considering the shape coefficient of the cladding layer, dilution rate, cladding width and cladding height. The microstructure of the cladding layer was analyzed, the horizontal and vertical microhardness of the cladding layer was measured. The results show that the optimal combination of process parameters was laser power 448 w, scanning speed 6 mm/s, powder feeding speed 9.0369 g/min. The analysis of variance shows that the laser power and scanning speed were the main factors influencing the cladding width and the scanning speed had a significant influence on the cladding height and shape coefficient. The microstructure analysis of cladding layer shows that planar crystals, cellular crystals, columnar crystals, dendrites and equiaxed crystals changed gradually from bottom to top. The average microhardness of the cladding layer was 672.2HV, which was 3.08 times of the matrix hardness.
Collaborative Filtering Recommendation Algorithm Based on User Preferences
Authors: Yan Yongjie , Xie Hui
Published: June 2020

The personalized recommendation technology provide people an effective method to solve the problem of information overload. Collaborative filtering is one of the key algorithm of recommendation technology, In this paper, the User-Movie (UM) model based on multilayer perceptron algorithm is a kind of item-based collaborative filtering recommendation algorithm. Therefore, the paper puts forward a new method to integrate item similarity in the UM model. Using Jaccard to find the similar items of current item, respectively. Experiments on the well-known datasets Epinions and Movielens show that the algorithm weighted by Jaccard in the case of sparse datasets and less neighbor achieves great improvement of prediction accuracy.