bluuebunny/crossref_metadata_2025 huggingface dataset:
Social class, language attitudes, and language use
Authors: Liu Binmei
Published: March 2020

Few previous studies have examined the impact of social class on language attitudes and language use in mainland China. A total of 215 questionnaires were collected from a university in China for this study. The participants were classified into four social classes: upper middle class, middle middle class, lower middle class, and lower class. Then an individual interview was conducted with 10 students. Findings show that the students from the upper middle class had significantly lower attitudes toward local dialects and they had the lowest percentage of current use of dialect at home. The study adds evidence to findings of previous studies that local dialects might face certain danger of maintenance. It also shows that this change would start from people from the upper middle class. The study also points out a possible future tendency that social class privilege will play a more significant role in English learning and education.
New research on the adoption and transformation of Chinese writing
Authors: Francis Norbert
Published: March 2020

A major study has been released on the emergence in East Asia of the logographic, or logo-syllabic, writing systems inherited from Chinese writing, attending primarily to the adaptations and innovations implemented in Korea, Vietnam, Japan and by speakers of the Tai languages of Southern China and Northern Vietnam. It contributes to our understanding of the fundamental mechanisms, of how speakers of different languages transformed the character script. The book points to overarching research problems concerning the relationship between language and writing, how aspects of this relationship are based on universal principles of learning exemplified in bilingual literacy. The research questions presented by the author will ultimately help us better understand literacy learning and the nature of reading and writing ability in general.
Entre influence et coïncidence: La réminiscence du grec dans l’arabe
Authors: Sartori Manuel
Published: March 2020

Deux points de vue s’opposent concernant les débuts de la grammaire arabe: la grammaire arabe serait apparue comme une
discipline autonome ou aurait été en partie influencée par des modèles grecs (peut-être par le biais de traductions syriaques). En lien avec
ce débat, il semble particulièrement instructif d’étudier la catégorie de ʿaṭf bayān. Selon Rafael Talmon, il s’agit d’une
‘invention’ de Sībawayhi (m.180/796?) basée sur la distinction entre ṣifa (‘adjectif’) et un modificateur qui n’est pas un
adjectif mais assure une fonction adjectivale (ʿaṭf bayān). L’article tente de montrer qu’un contraste similaire peut être
trouvé dans des sources grecques (et latines) antérieures sous la forme d’une distinction entre epitheton et
epexegesis. En prenant en compte la connaissance hellénistique chez les Arabes avant et à l’époque de Sībawayhi, il est
alors possible de soutenir que l’auteur du Kitāb, faute de terminologie appropriée, a emprunté, directement ou non, la
distinction aux sources grecques. Cependant, s’il ne s’agit évidemment pas d’une pure coïncidence, l’emprunt qui a donné naissance à la
catégorie de ʿaṭf al-bayān ne doit pas être interprété comme une simple influence. Il serait peut-être préférable de le
concevoir en termes de réminiscence: la mémoire, par voie diffuse, des connaissances grecques dans la nouvelle érudition grammaticale
arabe.
Radial contractility of actomyosin rings facilitates axonal trafficking and structural stability
Authors: Wang Tong , Li Wei , Martin Sally , Papadopulos Andreas , Joensuu Merja , Liu Chunxia , Jiang Anmin , Shamsollahi Golnoosh , Amor Rumelo , Lanoue Vanessa , Padmanabhan Pranesh , Meunier Frédéric A.
Published: March 2020

Most mammalian neurons have a narrow axon, which constrains the passage of large cargoes such as autophagosomes that can be larger than the axon diameter. Radial axonal expansion must therefore occur to ensure efficient axonal trafficking. In this study, we reveal that the speed of various large cargoes undergoing axonal transport is significantly slower than that of small ones and that the transit of diverse-sized cargoes causes an acute, albeit transient, axonal radial expansion, which is immediately restored by constitutive axonal contractility. Using live super-resolution microscopy, we demonstrate that actomyosin-II controls axonal radial contractility and local expansion, and that NM-II filaments associate with periodic F-actin rings via their head domains. Pharmacological inhibition of NM-II activity significantly increases axon diameter by detaching the NM-II from F-actin and impacts the trafficking speed, directionality, and overall efficiency of long-range retrograde trafficking. Consequently, prolonged NM-II inactivation leads to disruption of periodic actin rings and formation of focal axonal swellings, a hallmark of axonal degeneration.
Wapl releases Scc1-cohesin and regulates chromosome structure and segregation in mouse oocytes
Authors: Silva Mariana C.C. , Powell Sean , Ladstätter Sabrina , Gassler Johanna , Stocsits Roman , Tedeschi Antonio , Peters Jan-Michael , Tachibana Kikuë
Published: March 2020

Cohesin is essential for genome folding and inheritance. In somatic cells, these functions are both mediated by Scc1-cohesin, which in mitosis is released from chromosomes by Wapl and separase. In mammalian oocytes, cohesion is mediated by Rec8-cohesin. Scc1 is expressed but neither required nor sufficient for cohesion, and its function remains unknown. Likewise, it is unknown whether Wapl regulates one or both cohesin complexes and chromosome segregation in mature oocytes. Here, we show that Wapl is required for accurate meiosis I chromosome segregation, predominantly releases Scc1-cohesin from chromosomes, and promotes production of euploid eggs. Using single-nucleus Hi-C, we found that Scc1 is essential for chromosome organization in oocytes. Increasing Scc1 residence time on chromosomes by Wapl depletion leads to vermicelli formation and intra-loop structures but, unlike in somatic cells, does not increase loop size. We conclude that distinct cohesin complexes generate loops and cohesion in oocytes and propose that the same principle applies to all cell types and species.
Cryo-EM reconstruction of a VPS13 fragment reveals a long groove to channel lipids between membranes
Authors: Li PeiQi , Lees Joshua Aaron , Lusk C. Patrick , Reinisch Karin M.
Published: March 2020

A single particle cryo-EM reconstruction of an ∼160-kD N-terminal fragment of the lipid transport protein VPS13 reveals an ∼160-Å long channel lined with hydrophobic residues suitable for solubilizing multiple lipid fatty acid moieties. The structure suggests that VPS13 and related proteins, like the autophagy protein ATG2, can act as bridges between organelle membranes to allow bulk lipid flow between organelles.
Electrostatic responses of anisotropic dielectric films
Authors: Deng Hai-Yao
Published: March 2020

We study the electrostatic responses (i.e. retardation effects due to the propagation of electromagnetic waves are ignored) of a linear homogeneous and anisotropic (LHA) dielectric film to an arbitrary external electrostatic potential. A set of algebraic equations has been established to calculate the polarisation charges induced in the film. In our derivation, the idea is exploited that a physical boundary can be looked upon as a region of rapid variation in polarisation rather than a simple geometric separation. With this no boundary conditions are needed in solving the relevant electrostatics problem. Our approach makes it clear that the responses consist of two contributions, one arising from the very presence of surfaces while the other existing even in an infinite medium. In light of the results, we discuss graphene plasma waves under the influence of a LHA dielectric film such as a few-layer hexagonal boron nitride. It is found that the dispersion of these waves is strongly affected by the anisotropy at wavelengths comparable to the film thickness.
Measurements of Elastic Properties of Biological Hydrogels using Atomic Force Microscopy
Authors: Alam K , Umer J , Iqbal M , Hasan A
Published: March 2020

Biological hydrogels are widely used as extracellular environment for encapsulating and growing cells. Mechanical properties of hydrogels can influence cell function, mechanotransduction and cellular behavior such as growth, migration, adhesion, differentiation and morphology. Microenvironmental modulus of hydrogels dictates cell behavior and growth. The main purpose of the current study was to determine elastic modulus of two well-known hydrogels (Agarose and Gelatin Methacryloyl) using Atomic Force Microscope (AFM). The elastic modulus was calculated from force-deflection curve obtained by indenting an indenter in the direction normal to the plane of the gel surface. The elastic moduli of the prescribed gels were found to be strongly influenced by the level of concentration in the gel. Elastic modulus of 1% agarose and 2% agarose was found comparable with 10% GelMA and 20% GelMA, respectively. Results obtained from indentation experiments and those published in the literature revealed that AFM can be successfully and confidently used to determine elastic response of hydrogels in the solid state.
Effect of Heat Treatment Temperature and Time on Preparation of Porous Walled Hollow Glass Microspheres (PWHGMs)
Authors: Ravipati Disha , Singh Shweta , Dalai Sridhar
Published: March 2020

The development of hollow glass microspheres (HGMs) with porous walls provides a unique system in which filling agents can be incorporated into the porous walled hollow glass microspheres (PWHGMs). Applications of these have been increased due to the many proposed uses for such a material. They are widely used in various fields of science and technology because of their unique properties, such as catalyst supports, photo catalysts, sorbents, gas sensors, molecular sieves, drug and bioactive delivery systems as well as chemical and biological indicators, etc. PWHGMs with their interior hollow volume and porous walls offer greater storage capacity and pathways for retaining and releasing of stored material. PWHGMs as additives can be used to increase porosity in the electrodes for more electrolyte storage in lead acid batteries and enhance the energy performance of the battery. Further, PWHGMs have potential applications in sensor materials, fuel cells, solar cell, chromatograph column fillers and as micro reactors to encapsulate Pd for catalytic hydrodechlorination of chlorophenols in water. In this research, efforts have been made to prepare PWHGMs from readily available borosilicate glass frits in the laboratory using flame spheroidisation method. The effect of heat treatment temperature and time on preparation of porous walled hollow glass microspheres was investigated. Hollow glass microspheres with wall thickness of 0.5–2 μm were fabricated from borosilicate glass frits in air-acetylene flame. The prepared microspheres were heat-treated and acid leached to produce porous walled hollow glass microspheres. According to results, suggest that heat treatment times used in this research are not as effective as the heat treatment temperatures in changing the porosity (or phase separation) in HGMs and the resulting PWHGMs.
A Review on Property Reforms for Fiber Matrix Composites through Various Surface Treatment of Fibers
Authors: Basak Reshmi , Gohil Piyush P. , Dey Sudip , Pandey Krishna Murari
Published: March 2020

The primary factor that defines the final performance of any composite material is the fiber-matrix interface. Hence, efficient amount of adhesion is needed for full-fledged performance of composite materials. When fibers are used without surface modification, they tend to produce composites with low strength. This in turn leads to weak adhesion and poor bonding between the fiber and matrix. Hence, there is a massive apprehension to alter the surface of fibers through various procedures, in order to overcome their intrinsic downsides and effectively employ these materials in countless applications. This paper deals with a review of prevailing research studies fixated on the surface treatment of fibers.
Comparative studies on the corrosion behavior of some Zr-based amorphous alloys having different compositions in nitric acid medium
Authors: Sharma Poonam , Dhawan Anil , Sharma S. K.
Published: March 2020

The corrosion studies were performed on different composition of Zr-based bulk amorphous ribbon alloys such as Zr55Cu30Ni5Al10, Zr60Nb2Cu20Ni8Al10, Zr59Nb3Cu20Ni8Al10, Zr57Nb5Cu20Ni8Al10 and Zr60Pd5Cu15Ni10Al10 alloys at room temperature. The amorphous nature of all the above mentioned alloys was confirmed by X-ray diffraction (XRD). The corrosion behavior was investigated using potentiodynamic polarization and weight loss analysis methods at room temperature. Surface morphology of these corroded samples were investigated by optical microscopy and scanning electron microscopy (SEM). The results of the investigations revealed the fact that Nb containing Zr-based bulk amorphous alloys shows better corrosion resistance among all the investigated alloys due to the presence of Nb2O5. The presence of Nb2O5 on the surface of Nb containing Zr-based bulk amorphous alloy after immersion in HNO3 medium was confirmed by X-ray photoelectron spectroscopy (XPS) techniques.
Formulation of Heat Resistant Paint from Palm Oil Based Resin by Using Nano-Silica Particles
Authors: Ahmed Basir , Suhaila Muhammad Asyraf Anbalagan Nadia , Dalour Hossen Beg Mohammad , Yunus Rosli , Abdullah Arman
Published: March 2020

Paint is the main choices of coatings for various materials, machinery and buildings. Paints formulated from renewable resources and non-toxic chemicals are in demand. The Objective of this study is to prepare and characterize heat resistant paint from palm oil based resin by using nano-silica particles. Palm oil based paint was formulated using resin prepared from cooking oil waste, varied amount of nano-ceramics particles and fixed amount of pigment. Painted samples of aluminium sheet were prepared from formulated paint, cured oven heating method. Heat resistance and corrosion resistance were performed. Sample containing 0.6% silica showed best performance under heat no visible cracks even at 140 °C. Tafel plot shows corrosion resistance with Ecorr -0.91479 V, Icorr 3.2X10−6 A, Corrosion rate 0.0328216 mmy. The best formulation of paint can be benefited in many areas such as industrial paint industry, household appliances that required high thermal resistant and eco-friendly paint.
Study of Ferrate(VI) oxidation for COD removal from wastewater
Authors: Haneef Tahir , Raza Ul Mustafa Muhammad , Farhan Yasin H.M , Farooq Shahzeb , Hasnain Isa Mohamed
Published: March 2020

Produced water (PW) is the abundant by-product of oil and gas industries. It contains several organic pollutants and needs proper treatment before its discharge. This study investigated the effectiveness of Ferrate (VI) (Fe6+) oxidation for remediation of the organic compounds produced water. A series of batch experiments were performed by ferrate oxidation method. A glass beaker of 1000 ml as reactor covered with aluminum foil was used to protect from sunlight. Produced water sample of 300 ml and a pre-decided amount of Fe6+ was added to initiate the oxidation process. All experiments were performed at constant magnetic stirrer speed of 200 rpm at room temperature. The Fe6+ dosage of 1-25 mg/l, pH 1-7, and contact time 5-90 minutes were used to determine the effectiveness of Fe6+ for organic compounds degradation. The COD removal was increased with the increase in Fe6+ dosage and contact time. The maximum COD removal was achieved with Fe6+ dosage up to 15 mg/l; further any increase in Fe6+ dosage decreased the COD removal. The same trend was observed for pH, COD removal was increased until pH 5 beyond that COD removal was decreased. Maximum 55% of COD removal was attained under optimum conditions such as pH, Fe6+ dosage, and contact time were 5, 15mg/l and 50mins respectively. The results indicate that Ferrate (VI) oxidation is a promising method for the degradation of organic compounds in produced water.
Creating a Green, Clean and Worth Living City in the Digital Period
Authors: Hoi H T , Danh N T
Published: March 2020

The world’s urban population is constantly growing and this growth will put enormous pressure on infrastructure, especially water and waste. In order to reduce infrastructure pressure, reduce CO2 emissions, greenhouse effect and to improve the quality of life of people, creating a green city is an essential solution that is being cared for by many countries. Vietnamese people are not new to green spaces, that is, villages in this Vietnam not only contain the philosophy of living in harmony with nature, but also the most concentrated expression of the style of organizing living space. In a digital age, Green City or Smart City is an indispensable trend of the urban development process that humanity is thinking about. This paper focuses on analyzing outstanding issues in Ho Chi Minh City and at the same time, it also offers some solutions to a green, clean and worth-living city here.
Method for Decomposing Accuracy of Interferometer Based on Inertial Navigation Aid
Authors: Tian Guansuo , Duan Jingjing , Li Xiaosong , Zhou Guozhe , Lv Xin , Zhou Jun
Published: March 2020

In the complex electromagnetic countermeasure environment, in order to improve the detection ability is of great significance for aircraft application. Scientific and rational decomposition of direction-finding index plays an important role in system optimizing and product performance improving. In this paper, the direction-finding accuracy of passive detection device based on aided inertial information is calculated and analyzed. The accuracy demand of passive detection device is decomposed into accuracy of the attitude control algorithm, inertial device and structure installation. Through the calculation and analysis, the index of passive detection device will be 1.93°, when the direction-finding accuracy is 2°. The analysis results show that the index decomposition method is reasonable and effective, and can meet the requirements of the overall design, which provides a basis for the overall design.
Mathematical and geometry model of a spherical gear with three degree of freedom
Authors: Wang Demin , Xu Zhenquan , Wang Jun , Lu Xianting , Wang Baichao , Wang Junsheng , Zhang Xuzhong
Published: March 2020

This paper proposes a spherical gear pair with three degrees of freedom based on meshing transmission principle. The kinematic meshing relationship between the spherical gear pair is illustrated with its pitch spheres and pitch cones. This determines that the spherical gear surface is completed with two tooth surfaces of ring-involute spherical gear and a semi-spherical bevel gear. Mathematical models and numerical results of the two tooth surfaces are presented for obtaining geometry model of the spherical gear pair with the CAD three-dimensional molding technique. This study provides the basis for future studies to design and analyze a novel spherical gear.
A multi-sensor system and its error compensation for on-machine measurement
Authors: Zhang Zhenjiu , Ren Mingjun , Liu Mingjun , Xia Linzhong , Sun Lijian
Published: March 2020

In order to enhance the accuracy and efficiency of the measurement of on-machine test, a multi-sensor system is developed in this paper. This multi-sensor system consists of a touch trigger probe and a laser displacement sensor, so this measurement system has both the characteristics of high efficiency of laser displacement sensor and high precision of trigger probe. To enhance the accuracy of this measurement system, the main errors including sensor errors and motion errors of machine tools are tested and compensated respectively. Finally, experiments are conducted to validate that this multi-sensor system is suitable for on-machine measurement of workpiece.
Multi tool path managing and NC programming aided software based on UG
Authors: Gao Zihan , Lan Yingduo , Zhang Yidu , Wu Qiong , Zhang Sentang
Published: March 2020

UG is a universal CAD and CAM software which lacks of modules for specific applications. For some specific types of workpieces, a professional software can be developed to improve programming efficiency and quality using UG application program interface. A NC programming aided software is developed through UG secondary development method with the function of reorganizing application menus, creating programs using group technology, translating and managing tool paths created by hypermill. All these functions of the aided software can increase the rang of UG applications and make it easier and more efficient for specific problems.
Model Identification and Internal Model Control for 3D Printer
Authors: Xie Ruidong , Yi Yingmin , Yang Haichuan
Published: March 2020

A 3D printer system for selective laser sintering technology is used to establish a mathematical model of the relationship between laser power and temperature by using the recursive least squares method. Based on this model, the internal model control method is used to design the controller to realize the actual 3D printer. Temperature control, simulation analysis of internal model control and traditional PID control effects. The experimental results show that the feasibility, accuracy and internal model control of the recursive least squares identification model are fast, easy to implement, robust, and only one adjustable parameter, easy to adjust.
Design and Test of Wind Plate-type Residual Membrane Hybrid Separator
Authors: Zhang Yaxin , Li Hang , Li Shaohua , Zhang Hongze
Published: March 2020

In order to realize the effective separation of the residual membrane mixture, this paper designs the wind plate-type membrane hybrid separation device, which is composed of square air box, residual film discharge, conveyor belt, wind plate, soil and orange stalks shredded final row outlet, drive shaft, residual membrane mixture inlet, drive belt wheel and driven belt wheel, through analysis to determine the drain-outlet shape, number of wind plates and wind plate materials. Experiments showed that the membrane hybrid separation rate of membrane hybrid separation device is 91.5%, which meets the requirements of agronomy and realizes the effective separation of residual membrane mixture.
Application of Augmented Reality in Thermal Control Implementation of Satellite Pipe
Authors: Zhang Wei , Chen Changyu , Meng Fanwei , Hou Jun , Qu Haibao
Published: March 2020

This paper reviews the traditional thermal control implementation of satellite pipe in AIT process. As the thermistors and heating devices are too small compared to the satellite 3D model, the 3D design input is inconvenient to use. In order to improve efficiency and quality of thermal control implementation of satellite pipe, a system based on AR technology is designed. With the help of the system, the code and specification of the thermal control components are clear at a glance, so an ordinary operator can verify the polarity correctness of the thermal control implementation and the efficiency can be doubled.
Influence of structural parameters of venturi on internal flow field changes
Authors: Lv Chuanmao , Wang Puhao , Zhang Xiaoguang , Lv Haifeng
Published: March 2020

The influence of the inlet angle and the outlet angle of the venturi on the fluid flow state in the tube was studied. The control variable method was used to simulate the flow of the fluid inside the venturi by COMSOL software. The results show that when the inlet angle changes from 10.3° to 55°, the fluid flow velocity at the throat of the universal venturi is 19.5m/s, and the pressure varies from 1121.1Pa. When the outlet angle is changed from 10.3° to 55°, the fluid flow velocity inside the venturi varies by 0.8 m/s, and the pressure varies from 6060.2 Pa. Therefore, it can be concluded that changing the angle of the outlet has a greater influence on the negative pressure at the throat of the venturi. The change in the negative pressure caused by changing the inlet angle is weak, but the flow rate changes greatly.
A study on auxiliary steam reducing device in marine nuclear power plants
Authors: Zhao Huijing , Zhao Guanhui , Ma Rui
Published: March 2020

The pressure reducing device is one of the important parts of the auxiliary steam system in marine nuclear power plants. The pressure of auxiliary steam is reduced to meet the requirements of users with low pressure steam of second-loop system. This paper proposes a new auxiliary steam pressure reducing device, which can reduce the pressure of auxiliary steam in a concentrated region, and then provide low pressure steam to users. The new auxiliary steam pressure reducing device decreases the size, simplifies the adjusting mode, and improves the stability and reliability of auxiliary steam system. At last, the unsteady-state simulation based on Jtop is carried out on the auxiliary steam pressure reducing system. The results show that, when the pressure of high-pressure steam at upstream is changed, the steam pressure is stable, which is provided to users with low pressure steam.
Bayesian Inference of Proportional Hazard Rate Model under Progressively Type-II Censored Sample
Authors: Hu Min , Ren Haiping
Published: March 2020

Statistical inference of the parameter of the proportional hazard rate model is studied based on progressive type-II censored sample. Bayesian and empirical Bayesian estimators are first obtained under a scaled squared error loss function. Then we derived a class of Bayesian shrinkage estimators motivated by the idea of Thompson’s shrinkage algorithm based on obtained estimators. Finally, a practical example and Monte Carlo simulations illustrate that the proposed Bayesian shrinkage estimators are more robust comparing to the Bayesian and empirical Bayesian estimators.
Blind identification of network protocols based on improved Apriori algorithm
Authors: Chen Yingchun , Dai Yuchen , Xue Jingliang , Dong Fang
Published: March 2020

With the development and application of network technology and private protocols, more and more unknown protocols are found in communication networks. Analysis and identification of unknown protocols has become an important and difficult problem in obtaining valuable information from data. Based on the traditional Apriori algorithm, a reduced bit string algorithm and a weight compression algorithm are proposed to identify the unknown protocols according to the characteristics of network unknown protocol data in this paper. These proposed algorithms make use of location information, matrix compression, bit string and weight compression to gradually improve the identification accuracy and the processing efficiency of unknown protocols. Experiments on simulation data and actual data demonstrate the performance of the improved algorithms in terms of identification accuracy and time efficiency.
Major crop pests identification research based on Convolutional Neural Network
Authors: Luo Lijun , Ren Yan , Gu Ling , Wang Tianjiao , Zhou Fenglin , Yang Wanyi , Zhang Hongyan , Li Dongyu , Xu Jingwen
Published: March 2020

There are many kinds of crop pests in China and they are prone to disasters. Agricultural pests pose a serious threat to crop growth, so how to effectively identify crop pests is crucial. With the development of computer vision technology and artificial intelligence, the combination of computer vision technology and classification and identification of pests has become a hot and difficult point for experts at home and abroad. In this paper, based on the bag-of-words model and the GoogLeNet model, 2200 pest images collected were used as experimental samples to study the identification of crop pests. The experimental results show that the average classification accuracy of the traditional bag-of-words model is about 56.41%, and the GoogLeNet model recognition accuracy can reach 96.35%. The GoogLeNet model based on transfer learning has higher precision and stronger anti-interference ability than the traditional bag-of-words model.
The research and development of Soldering materials applied in IGBT modules packaging
Authors: Liu Keming , Yao Erxian , Yang Jinlong , Wang Yiwen , Hu Xiaogang
Published: March 2020

Power modules have attracted much attention in the market, especially for high-voltage applications like switch mode power, automotive powertrain. As the requirement of high reliability, high-temperature operation improves, the packaging materials should develop to meet the applications with high properties. In this paper, the soldering materials such as Sn based lead free solder, SnPb solder, Ag-sinter are demonstrated. Soldering materials reliability is described on reliability testing especially for power cycling, temperature cycling testing, thermal shock testing. The concept is based on different applications and soldering process on Si power modules and SiC power modules. Important materials properties of thermal conductivity, CTE (coefficient of thermal expansion), elastic modulus, melting point are discussed. By comparison, Ag sintering process has a good application in high power modulus especially for SiC. SnAg solder also has the potential application in SiC modulus by IMC diffusion soldering technology.
Preparation and Characterization of Cross-linked Poly(lactic acid) / Poly(butylene succinate) Blends
Authors: Zhao Miao , Hu Rong-Rong , Wang Hong , Yao Shan-Shan , Jin Fan-Long
Published: March 2020

Bio-based blends were prepared via solution blending and thermal cross-linking of poly(lactic acid) (PLA) and poly(butylene succinate) (PBS) using dicumyl peroxide (DCP) as a cross-linking agent. The thermal stability, flexural properties, and fracture toughness of PLA/PBS blends were investigated. The thermal stability of the blends increased with the addition of PBS and further improved by the cross-lingking. The flexural properties of the blends decreased with the addition of PBS and increased after the cross-lingking. The impact strength of the blend cross-linked with 0.10 wt% DCP increased to 4.25 kJ/m2, which increased by 32% compared to that of pristine PLA.
Synergistic effect of OZrP on the combustion properties and thermal degradation behavior of intumescent flame retardant polylactide
Authors: Zhan Jing , Liu Xueli , Cao Chunhua
Published: March 2020

Flame retardant polylactic acid (PLA) composites were prepared and studied using melamine phosphate (MP) as an intumescent flame retardant and organophilic alpha-zirconium phosphate (OZrP) as a synergistic agent. The flammability properties of PLA composites were investigated by UL-94 tests and microscale combustion calorimetry (MCC) experiments. It’s found that the incorporation of organically modified layered OZrP can further improve the flame retardancy of PLA composites and there exists an optimum content of OZrP. The SEM results about the char indicate that more homogeneous and compact char were formed with OZrP. In addition, the effect of OZrP on thermal degradation process of PLA composites was analyzed using in situ FTIR. The results show that the addition of OZrP decreases the onset decomposition temperature, but increases thermal stability at high temperature.
Steady State Energy Flow Analysis for Energy Internet Planning
Authors: Ji Xiaoqing , Wang Fei , Song Feng , Liu Junxu , Liu Jie , Xiong Dang
Published: March 2020

The planning and design of energy Internet is an important work. The basis of this work is energy flow analysis of the design network. In this paper, the energy flow analysis model of typical gas-electricity interconnection system is established. The mismatch equations and iterative algorithm for energy flow solution are given. The effectiveness of the algorithm is verified by a typical gas-electric interconnection example.
Identification of market power abuse in China’s electricity market
Authors: Cheng Ziyun , Li Hao , Xu Huihui , Dong Li , Tao Hongyuan , Hua Huichun , Wang Shenghua
Published: March 2020

The goal of this paper is to find a method to identify violations, which is suitable for China’s electricity market. Therefore the key problems in the process were discussed, that is, the trading rules and marketization degree which were different from those of foreign countries. So this article has done the following works to solve the problems. Firstly, this paper classifies and compares the identification indexes of market power abuse, and analyzes the advantages and disadvantages of each index, based on which an index system is proposed. Secondly, An intelligent identification algorithm based on support vector machine(SVM) is introduced and improved to solve the data imbalance problem. Also, the index system and the improved SVM were combined to cover the economic principle as well as improve the identification efficiency at the same time. Taking the simulation data as an example, the rate of violation recognition reaches 100%, which indicates that the method proposed in this paper is feasible and effective.
Study of distribution network fault location based on IACA
Authors: Liu Xue , Jia Jun , Wang Jian
Published: March 2020

The probability of the distribution network fault is the highest in power network. Correct fault location of distribution network is very important for the reliability of power supply. A simplified model of distribution network is established in the paper. Then the switching function and evaluation function are introduced for distribution network fault location. Because of some defects in fault section location of distribution network in ACA(Ant Colony Algorithm), the IACA(Improvement Ant Colony Algorithm) method is proposed. The results of an example shows that the method was correct and effective.
A new precharging strategy for hybrid MMC based on HBSM and FBSM
Authors: Han Lei , Jiang Junfeng , Yao Haitao
Published: March 2020

Precharging of the modular multilevel converter (MMC) is an important basis for ensuring the normal operation of MMC-HVDC system. The hybrid MMC based on full bridge sub-module (FBSM) and half bridge sub-module (HBSM) has reliable performance in DC fault ride-through capability and is receiving more and more attention. Due to the different charging characteristics of FBSM and HBSM, the sub-modules (SMs) capacitor voltages may be different at the end of the uncontrolled precharging process. This paper introduces conventional uncontrolled precharging strategy of the hybrid MMC and points out the problems in the process. Then a three-stage precharging strategy is proposed in this paper. This strategy can eliminate the capacitor voltages imbalance of different SMs and solve the problem of unsuccessful self-taking energy of HBSM during precharging process. Finally, simulation and analysis of the uncontrolled precharging process based on the proposed strategy are carried out.
Design and Development of Miniature Non-contact Multi-range Current Sensor
Authors: Xu Aidong , Li Licheng , Li Peng , Wang Zhiming , Wu Zhibing , Hao Changjin
Published: March 2020

High-performance sensors and high-efficiency and accurate measurement technology are the basis of power grid control, monitoring, analysis and decision-making. Current monitoring devices commonly used in power systems cannot meet the need for simultaneous measurement of steady-state current and transient current. In this paper, a high-performance current sensor based on giant magnetoresistance sensor is developed, and key technologies such as sensor structure, sensor chip selection, signal processing circuit and electromagnetic compatibility are designed. The experimental results show that the micro current sensor can accurately measure the steady-state current of 1000A and the transient current of 20kA. At the same time, it has the advantages of small size, high sensitivity, large measurement range, convenient installation and high integration, which meets the measurement requirements of smart grid.
Static characteristic analysis of a transmission line detection robot
Authors: Wen Guang , Su Rui , Yao Kun , Zuo Fangjun , Wu Xuefeng , Hui Chongli
Published: March 2020

The functions of the transmission line inspection robot mainly depend on the metal structure. Whether the strength of the metal structure meets the requirements is directly related to the reliability of the robot. Taking a flying-wheel transmission line inspection robot as the research object, the static characteristics of its metal structure under common load conditions are analyzed by finite element software, and whether the strength of the structure meets the application requirements is investigated. Through analysis, it is found that the maximum working stress of the metal structure of the robot under working load appears near the left wheel pressure, and its value is less than the allowable stress of the material. With the increase of wind pressure, the maximum working stress of the mechanical structure of the robot increases.
Design of rescue equipment for high altitude electrical operation
Authors: Mao Xiaojun , Zhang Yunfeng , Wang Zhan , Pan Wangxin , Zhang Weilin , Wang Jie , Song Jingen , Hu Xiaobo
Published: March 2020

In view of the fact that there are few kinds of robots can cross over obstacles in high-altitude electric power operation. Meanwhile, the existing robots are difficult to rescue falling workers, therefore, a robot that can walk over obstacles on the power transmission line is developed to solve the difficulty of high-altitude electric power transmission line rescue. The operating environment of the rescue robot for high-altitude transmission line is analyzed, and the obstacle jumping movement and rescue mode of the rescue robot are planned. The mechanical mechanism of rescue robot is designed. The robot is simple in structure, and can bear 500kg weight. It has strong mobility and wide range of application.
Research on Computer Network Service Quality Optimization Method Based on Integration of Multiple Artificial Intelligence Technologies
Authors: Huang Yan
Published: March 2020

Computer network optimization refers to the design of network protocol according to the solution mechanism and implementation scheme given by optimization theory, so as to solve the problems of task scheduling, resource allocation, system parameter allocation and network resource deployment in the network. With the rapid expansion of the coverage of computer networks and the advent of the network era, the development of artificial intelligence has been promoted. Artificial intelligence has been widely used in computer network technology. In order to further improve the service quality of the network, not only the existing network protocols need to be evaluated, but also the network reconstruction project needs to be carried out. Based on the current situation of computer network service optimization, this paper analyzes the difficulties in the process of optimization and puts forward the corresponding countermeasures, and expounds the importance and necessity of the integration of artificial intelligence technology for the optimization of computer network service quality.
Design and Research of under-Voltage Protection Circuit for Motor Driver Chip Based on Special Integrated Chip
Authors: Luojie  , Li Wenchang , Lu Huaxiang
Published: March 2020

Intelligent power integrated circuit chips play an increasingly important role in industrial automation, domestic medical appliances, automotive electronics, especially in modern military, aerospace and other fields. Based on the analysis of the current front-end verification problem of digital application specific integrated chip, the composition and working principle of motor drive chip, the design and composition technology of undervoltage protection function module and the perfect protection circuit not only ensure that the chip can work normally under some harsh conditions, but also play a vital role in the safety of the whole system sometimes. After the motor chip is verified by the flow sheet, packaging, testing and test result analysis are carried out to further predict and adjust the function and reliability of the motor chip. On the basis of analyzing the current front-end verification problem of digital application specific integrated chip, the circuit structure is simple, no additional bandgap reference circuit is needed, and the voltage comparator circuit is also omitted.
Classification of Encrypted Text Based on Artificial Intelligence
Authors: Zhang Bo
Published: March 2020

With the development of internet, information security is essential. The traditional decryption method only works for single encryption method. New models based on Artificial Intelligence to decrypt different kinds of encryption methods. Data features were extracted by tf-idf algorithm and applied into different models. The primary models to decrypt message without knowing whether encryption methods are logistic regression, lightGBM, and ensemble algorithm to decrypt encryption data. Comparing the performance in the models based on logistic regression and lightGBM algorithm respectively, we concluded that both the accuracy and F1 score of logistic algorithm are better than those of lightGBM algorithm. We also made improvement on the model by using ensemble algorithm. A more preferable performance including the accuracy and F1 score has achieved with multiple algorithm. Therefore, ensemble algorithm is more suitable for building general model to decrypting different kinds of encryption methods.
Type Identification and Classification of Cascading Failures of Time Sections of Dispatching and Operation Based on Data Mining
Authors: Yue Junying , Li Cunbin
Published: March 2020

The probabilistic distribution of cascading outages is one of the main measures to describe the propagation of cascading outages, and to evaluate the risk of the large-scale outages of the power system. Based on the analysis of the basic principles of data mining, basic principles of dispatching and operation and basic types of cascading failures, this paper give the type identification, occurrence probability and severity degree of cascading failures to provide some references for the relative researchers.
Research on the Model Construction and Development of Computer Information Acquisition System
Authors: Deng Rui
Published: March 2020

Nowadays, the number of crimes committed by computers is increasing, so computer forensics technology has become the focus of people’s research and attention. This paper designs the module structure of the computer information acquisition system, and focuses on the realization of the key technologies of the computer information acquisition system. It discusses the application of data mining on the web, and focuses on the analysis of web text mining technology. This paper proposes a method to acquire UNIX kernel information at the user level, and introduces a utility program to acquire index node table in UNIX system. At the same time, a prototype of a professional news information acquisition system is proposed. Taking the prototype of the system as the background, the application of information acquisition on the web is realized by using relevant technologies of web information search and web text mining.
Design and Implementation of Academic Search Aggregation Engine
Authors: Yan Jun , Xu Peng , He Yu , Wang Zhi
Published: March 2020

With the rapid development of the global Internet, academic search engines have become indispensable tools for academic research like literature, papers, books, preprints, and abstracts. The total amount of network information is growing rapidly today, and the global paper output doubles every five years. For academic researchers, it is very difficult to find papers that meet the needs in a large number of articles. Additionally, as the quality of journal papers varied, finding high-quality papers and accurately locating them is getting harder and harder. Many researchers find it tiring and inefficient that when looking for research fields, they need to read through a large number of articles in search results, and manually classify them. Through the clustering algorithm and data visualization and other related technologies, the systematic integration and classification of the search papers will help the researchers to accurately locate the required articles, and can greatly reduce the time for searching the documents. Regarding the previously stated problems, this thesis designs and implements an academic search aggregation engine (referred to as “aggregation engine”) based on cloud computing and some clustering algorithms. On the one hand, the aggregation engine distributes the user’s search request to multiple academic search engines, and then collects and summarizes the paper results, thereby uniformly displaying the search results; on the other hand, from the large number of papers obtained from academic search engines, the aggregation engine analyzes their titles, abstracts, and keywords, clusters papers with similar research points, and visualize clustering results to users, so that the result can be macroscopic and intuitive, grasping all the papers and the research points they involve. This paper first introduces the research background of the subject, through the investigation of the existing search engine and the existing aggregate search engine, it analyzes the needs of the researcher and other customers for the paper search; according to the demand analysis, we proposes a system design that distribute the search request to multiple academic search engines and then aggregated results. Finally, we realised the implementation of the aggregate search engine, and verified the effectiveness of the system through tests
Research on S2B2C E-commerce Model of Fresh Agricultural Products in the Field of Social E-commerce
Authors: Fu Lijun
Published: March 2020

Traditional e-commerce is facing the problems of exhaustion of traffic, slowdown of growth and decentralization of sales channels. At this time, social e-commerce is emerging. As one of the new modes of social e-commerce, S2B2C social e-commerce model has many advantages, such as reducing the purchase cost of enterprises, improving the standardization of the products delivered. The application of S2B2C e-commerce model in retail of agricultural products can solve the problems of difficult warehousing, logistics and low standardization. Based on a brief introduction of social e-commerce and S2B2C mode, this paper analyzed and studied the S2B2C mode of fresh agricultural products from the perspective of social e-commerce, and provided the basic technical framework for the implementation of S2B2C mode.