bluuebunny/crossref_metadata_2025 huggingface dataset:
The Quantum Calculation for Valence Band Structure of Strained Zinc-blende GaN Using Six-Band Based k·p Method
Authors: Liu Yaqun , Wang Everett X. , Zhang Gary , Li Xiyue
Published: November 2021

The variations of valence band energy with stress effects in zinc-blende GaN are proposed in this paper. The calculations are based on a six-band strain dependent k·p Hamiltonian, and can be self-consistently solved by Schrödinger-Poisson equation. Accurate physical pictures are given for the quantized valence subband structure under biaxial and uniaxial stress in (001) surface along the [110] direction accounting the quantum confinement effect. The warping of the energy profile results in carrier distribution change. This research will be beneficial for improving the hole mobility and the selective of optimum stress for group-III nitride semiconductor based devices.
Study on Wear Debris Characterization of Polycarbonate Urethane (PCU) as a Bearing of Artificial Hip Joint
Authors: Lestari W D , Ismail R , Jamari J , Bayuseno A P
Published: November 2021

As with all artificial joints, wear debris is of particular concern due to its effect on both implant life and the in vivo biological reactions that can occur. The purpose of the research is to study debris characterization of PCU. Wear particle is produced from testing the PCU material using a pin on disc wear tester within 50000 cycles. This study showed that the PCU wear debris gotten from the simulator had various different shapes, including laminar and spherical types. The morphology of worn surface and wear debris analysis showed that wear mechanism of PCU were fatigue wear. Thus we conclude that PCU is expected to be a lifetime implantation of artificial joint.
Design and Research of Highly Integrated Multi-channel Tile-type T/R Module
Authors: Chen Ziran , Huang Zhi , Zhang Qi , Zhang Meng
Published: November 2021

This paper introduces a design scheme and key technology of a multi-channel tile-type T/R module. In order to meet the requirements of high reliability, miniaturization, lightweight and multi-functional integration, a vertical interconnection design method of high integrated multi-channel tile-type T / R module is proposed. LTCC technology is used to achieve high-density stacking of radio frequency devices, while bare chips are used to improve system integration and reliability. The module integrates 4 isolated transceiver channels with a size of 40mm×40mm×10mm, which significantly reduces the volume and weight compared to the traditional T/R module structure. The module simulation results prove that the design scheme is easy to implement and fault location maintenance, and the test results meet the design indicators.
Development of GIS Switch State Judgment System Based on Image Recognition
Authors: Zhao WenHan , Wen Feng , Han Chen , Chu Zhoujian , Yao Qingyue , Ji Kesong
Published: November 2021

Aiming at the fast opening and closing speed of the GIS isolation/grounding switch, manual observation is more difficult, so it is difficult to judge the current switch status. This paper proposes an OpenCV-based image identification algorithm to identify the position of the switch movable contact during the opening and closing process of the isolating switch, thereby judging the state of the isolating switch. This system uses Raspberry Pi as the main hardware core, the server drives the CMOS camera through Raspberry Pi 4B, collects image information in the GIS optical observation window, and performs simple processing, and transmits it to the Raspberry Pi 4B based on the UDP protocol as the main core. In the upper computer and adopt the target detection algorithm based on OpenCV to track the current isolation/grounding switch contact position and determine the current opening and closing state.
LFT Bond Graph for Online Robust Fault Detection and Isolation of Hybrid Multi-Source System
Authors: Boukerdja Mahdi , Radi Youness , Omprakash  , Sood Sumit , Ould-Bouamama Belkacem , Chouder Aissa , Gehin Anne-Lise , Dieulot Jean-Yves , Bressel Mathieu
Published: November 2021

Green hydrogen is undoubtedly the most promising energy vector of the future because it is captured by renewable and inexhaustible sources, such as wind and/or solar energy, and can be stored over the long in high-pressure cylinders, which can be used to feed the fuel cells to produce the electricity without emitting any pollutants. The system incorporated renewable sources and process used to produce the green hydrogen is the hybrid multi-source system (HMS). The production of hydrogen needs a reliable HMS, which always requires online monitoring for real-time Fault Detection and Isolation (FDI) because the risk of accidents in HMS and safety issues increases due to the possibility of faults. However, online monitoring of FDI is challenging due to the multi-physics dynamics of HMS and the inclusion of uncertain parameters and several disturbances. This paper proposes an online robust fault detection algorithm to detect system faults based on the properties of the graphical linear fractional transformation bond graph (LFT-BG) modeling approach. Here, the analytical redundancy relations (ARRs) and their uncertain parts extracted from the LFT-BG model are used to develop an online robust FDI algorithm for HMS. Numerical evaluations of ARRs and their uncertain parts, respectively, generate the residual signals known as “faults indicators” and their uncertain bounds known as “adaptive thresholds.” These thresholds evolve with system variables in the presence of parameter uncertainties for ensuring robust FDI for HMS to minimize false alarms. The validation of this approach is carried out using 20sim software that is familiar with BG modeling.
Study on the Electrical Conductivity of Inorganic Conductive Network in Sediments
Authors: Zhao R Y , Zhao Z W , Weng Z J , Fang Y , Jiang H L
Published: November 2021

The inorganic conductive network provides an essential channel for electron transport and supports the biogeochemical process in sediments, but the conductive mechanism of conductive network is not well understood. In this work, theory of circuit and electronics was applied to build a three-dimensional (3D) resistivity network simulation model for exploring the conductive mechanism and analysing the effect of the particle size on the conductive characteristic of inorganic conductive network. In order to simulate the real sediment environment, inorganic composites with silica (SiO2) particles as matrix using magnetite (Fe3O4) particles as fillers are constructed. The simulation results reveal that the electrical conductivity of these composites rises nonlinearly with the increasing volume fraction of conductive fillers, which is consistent with the percolation theory. Moreover, small-sized conductive particles or large-sized matrix particles are confirmed to exert a positive part in enhancing electrical conductivity of composites.
Research on Design Electrode Channel in Microfluidic Chip
Authors: yingmei Zhou , Jian Lv
Published: November 2021

In recent years, microfluidic chips have been widely used in food safety, environment detection, clinical diagnosis and biochemical. However, Digital microfluidic chips(DMF) are attracting more and more eyes because picoliter-microliter-sized sample droplets can be accurately and automatically manipulated. In this paper, a method of design electrode channel height is studied to improve the efficiency of the voltage driving.
A Flexible Solar-blind Ultraviolet Photodetector based on Carbon Nanodots
Authors: Zhu Mengru , Zhao Zhiwei , Fang Yong , Weng Zhengjin , Lei Wei
Published: November 2021

A flexible solar-blind ultraviolet (UV) photodetector based on the carbon nanodots (CNDs) was fabricated on a polyethylene terephthalate (PET) substrate. The responsivity of 1.2 mA/W is obtained for 10 V applied bias under 254 nm illumination. Further, bending tests were carried out under the 0.2% strain, and the results showed that this flexible photodetector had stable characteristics and no obviously decrease of the photocurrent. The bending performances exhibit excellent potential for the fabrication of smart and flexible photodetectors.
Researches on the Technology of Measuring Grain Moisture based on 555 Integrated Circuit
Authors: Zhiqiang Wan , Qingqing Zhang , Liang Xu
Published: November 2021

Grain is the material basis of human existence and development. Food quality has an important effect on people’s physical health for our country. Moisture content of grain has been an important factor in affecting food quaility. Every year, a substantial part of the food production is lost because of too much water contained in the food without drying. According to the annual statistics of the country’s harvest, loss of food due to drying time caused by water take up 500 - 10000000 tons, according to approximate 1.5% - 3% of the total grain output.With the development of science and technology, grain moisture detection, especially the real-time and accurate detection, has attracted more and more purchase, production, processing, storage, transportation, and attention from various aspects. Under this problem context, hardware-circuit-control system of grain moisture detection based on ATmega128 has been investigated and designed.
Study on the performance of Double-pipe phase heat exchangers in waste heat recovery with heat storage and discharge
Authors: Yan Quanying , Guo Yuan , Ma Chao
Published: November 2021

The heat transfer performance of the double-pipe phase change heat storage and exothermic device and its cycle system for waste heat recovery was studied experimentally. 10 different experimental conditions were set by adjusting the inlet temperature, inlet flow rate and heat storage time of the phase change heat storage and exothermic device to study the changes of the outlet temperature, heat exchange and the inlet and outlet temperature of the heat sink of the heat-using device. The experimental results show that the higher the inlet temperature, the higher the flow rate and the longer the heat storage time, the higher the average heat exchange and the longer the heat release time of the heat exchanging device. The phase heat exchanger designed and used in this experimental research provides a certain experimental basis and data reference, which can be used for waste heat recovery in industrial and other fields.
Research on oil-gas Pipeline Leakage Detection Method Based on Particle Swarm Optimization Algorithm Optimized Support Vector Machine
Authors: Gao Jianfeng , Zheng Yu , Ni Kai , Zhang Huaizhi , Hao Bin , Yan Jialin
Published: November 2021

In order to solve the problem of low accuracy in oil-gas pipeline leak detection, a pipeline leak detection method based on Particle Swarm Optimization (PSO) algorithm optimized Support Vector Machine (SVM) is introduced. This method uses PSO to solve the penalty factor ‘c’ and kernel function parameter ‘g’, and constructs the pipeline leakage detection model of SVM. We set up an experimental platform to collect negative pressure wave signals under different working conditions. After wavelet domain denoising and data preprocessing, four eigenvalues of Mean, Standard Deviation, Kurtosis and Skewness are extracted from the signals to form the eigenvector samples, which are taken as input of SVM, and four working conditions of normal, leakage, rise and fall are taken as output. Through experimental verification, the comprehensive performance of PSO-SVM algorithm is better than that of traditional SVM, Genetic Algorithm optimized SVM and grid search algorithm optimized SVM. The POS-SVM algorithm can be applied to the leak detection of oil-gas pipeline.
Analysis of hydrogen production capacity of off-grid photovoltaic system based on PVsyst software simulation
Authors: Li Jiantao , Li Yongguang , Zhu Boxu , Ma Xinxia
Published: November 2021

As a typical green energy, hydrogen energy has many advantages. The traditional hydrogen production methods are more polluting. However, the use of electricity generated by photovoltaic systems to produce hydrogen can not only make full use of local solar energy resources, but also achieve environmentally friendly hydrogen production. In this work, we use PVsyst software to model and simulate a 30kW off grid photovoltaic power plant in a region of Shanghai, and calculate its power generation. Combined with the energy consumption of hydrogen production equipment, we evaluated the hydrogen production capacity and pollutant emission reductions, and we also analyzed the performance ratio and power loss of photovoltaic system, which verifies the environmental protection of photovoltaic hydrogen production, and provides a reference for photovoltaic hydrogen production researchers.
The on-line detection technology of oil level in main transformer conservator of an 110kV Substation
Authors: Liu Jun , Hu Yujing , Yang Wen , Pan Xiongwen , Li Yibin , Qu Guomin , Xie Yi , Qiu Wei
Published: November 2021

The oil level of transformer conservator is related to the safe operation of transformer. There is no better way to detect the oil level of the conservator, when the indication of the oil level gauge is unclear or the jam fault. Through the selection of ultrasonic sensor, design of measurement and verification device and field practice, this paper studies and develops an on-line detection technology based on the ultrasonic principle, which can effectively and accurately detect the oil level of existing conservator types such as diaphragm, capsule and corrugated conservator, and is not limited by the detection environment.
Application of Fuzzy Control in Ocean Nuclear Power Plant Control
Authors: Dai Chunhui , Song Ping , Chen Lie , Lao Xingsheng , Zhang Kelong
Published: November 2021

In marine nuclear power plants based on molten salt reactors, the complexity of core nuclear reactions, fuel fluidity, and the “false” water level characteristics of the steam generator water level make it unrealistic to establish an accurate mathematical model, so it is difficult to implement traditional PID control methods. This has increased substantially. The fuzzy control has a good solution to this feature. Therefore, combined with the fuzzy control that does not depend on the precise mathematical model of the controlled object, the fuzzy controller of the nuclear power plant is designed, and the control research of the core power is obtained respectively through MATLAB/Simulink simulation. It shows that the designed fuzzy controller can achieve good control of nuclear power plants.
Comparison and research of acoustic emission testing standards for atmospheric storage tank
Authors: Zhang Shuxin , Wang Weibin , Yang Yufeng , Zhang Qiang , Wu Gang , Luo Jinheng , Dong Xunchang
Published: November 2021

The acoustic emission testing standards ASTM E1930, BS EN 15856, JB/T 10764 and Q/SY GD 0211 for atmospheric storage tank are compared and analysed. Combined with production practice, the revision direction and reference suggestions of acoustic emission testing standards for atmospheric tank were proposed.
Applicability of single sample method to test strength parameters of sandstone
Authors: Li Shaoan , Li Wenxia , Hu Yunlei , Zhang Tao , Shi Xiangchao
Published: November 2021

The single sample method allows the mechanical parameters of rocks to be obtained with very few rock samples; however, the method has not been widely used. This is mainly because the yield point of the single sample method is more difficult to control than the conventional triaxial compressive test and the effect of the different control methods on the measured data is not well understood. The single sample method obtains the strength parameters of the rock by loading a single rock sample with multiple stages of confining pressure. Multistage loading tests are divided into peak strength control and long-term strength control according to yield point control. In this study, multistage loading tests of sandstone were carried out to obtain strength parameters using long-term strength control. The results show that sandstones undergo seriously brittle damage in conventional triaxial compressive tests. Although the sandstones have been rigorously selected, they still vary considerably, and long-term strength points are more difficult to control. The error of strength parameters of sandstone obtained using the single sample method may exceed 20% compared to those obtained by conventional triaxial compressive tests. So this method must be used with caution for sandstones.
Research on Special Support Technology of Gob-side Entry Retaining with Filling the Non-roadway Side in the Thin Coal Seam
Authors: Feng Renjun
Published: November 2021

By taking a certain mining area of No.2 coal seam in a coal mine as the research object, special support technology of gob-side entry retaining with filling the non-roadway side was researched. Based on the geologic features of this mining area, support method of gob-side entry retaining was proposed. The method replaced the dense wood prop with single prop, and cooperated intersection hinge roof. The support parameters were calculated, and time-space coordination between each support process was researched. The field measured data showed that this support method had a remarkable effect and strictly controlled the deformation of gob-side entry. This research formed a support system and mining system based on this condition. It has important reference meaning to safe and efficient mining coal resource with similar geologic condition.
Influence of Soft Segment Molecular Structure on Physicochemical Properties of Cellulose Nanocrystals based Polyurethane
Authors: Zhang Maolan , Wang Jiale , Li Yan , Lu Xiujuan , Liao Xiaoling , Zeng Guoming
Published: November 2021

SPUs are commonly used in clinic due to their good biocompatibility and can respond to different external stimuli. Among them, introducing CNCs into PUs to prepare water-driven PUs had attracted increasing attention. Herein, we report two new types of CNCs based PU nanocomposites by chemically cross-linking CNCs and PDLLA soft segment with flexible PEG chain or rigid piperazine ring structures. Specifically, the prepared nanocomposites were characterized by their morphology, chemical structure, thermal property, hydrophilicity as well as crystallinity, and the results showed that regardless of the molecular structure of the PDLLA, chemically cross-linking CNCs and PDLLA could significantly improve their compatibility. In addition, when the soft segment contains hydrophilic flexible sections, ie, PEG 200, the compatibility of CNCs with PU and crystallinity of obtained materials were better, and when the PDLLA contains a rigid cyclic structure, the thermal stability of obtained CNCs based PU would be more excellent. These results suggest that we can design the soft segment molecular structure of CNCs based PU to meet the performance requirements of different biomedical applications.
Study on Oil Absorption Properties of Magnetic Chitosan Stearic Acid Compound
Authors: Zhang Ya , Wang Yuyi , Nie Wen , Zheng Han , Wang Qihao , Long Yunqian
Published: November 2021

The magnetic chitosan-stearic acid compound was prepared for using chitosan and stearic acid. The morphology, structure and hydrophobic property of the magnetic chitosan-stearic acid compound were characterized. The influences of oil type and temperature on its oil absorption performance were determined. The results shows that the magnetic chitosan-stearic acid compound has a fluffy structure with a contact angle of 133.65°, indicating that the compound has a good hydrophobic property. Different oils have various impact on the oil absorption performance of the magnetic chitosan-stearic acid compound. The magnetic chitosan-stearic acid compound has the best oil absorption to crude oil, with an oil absorption rate of 4.12 g/g. With the increase of temperature, the oil absorption rate first increases and then decreases. There is an optimal temperature for oil absorption, with a temperature of 40°C.
Preparation of Self-leveling Mortar Based on Anhydrite-II Phosphogypsum
Authors: Zhang Yu , Yang Jiahao , Liu Yu , Liu Bin , Zhao Fengqing
Published: November 2021

The construction material from anhydrite-II phosphogypsum is dense in structure and has good water resistance. But its disadvantages are low hydration activity and long setting time. In this work, anhydrite-II phosphogypsum is modified by adding a composite activator, which is made of sulfuric acid modified steel slag, β-hemihydrate gypsum and calcium aluminate cement. With this, the hydration rate of anhydrite-II phosphogypsum is clearly increased and setting time shortened. The performance of self leveling mortar prepared is as per JC/T 1023-2021, with softening coefficient of 0.8.
Oxygen and methyl co-modified carbon nitride for enhanced photocatalytic dagradation
Authors: Liu Wenwen , Xu Kaiqin , Peng Renfu , Xie Fang , Chen Huan
Published: November 2021

Carbon nitride (C3N4) is a promising photocatalytic material to degrade various pollutants. However, the degradation activity is restricted by the limited light absorption and fast recombination of photoinduced carriers. Herein, a structure modification strategy by introducing a functional reagent during the polymerization process was adopted. The structure, composition and morphology of prepared materials were investigated by X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy. Benefiting from the implantation of oxygen and methyl groups in triazine unit of C3N4, enhanced light absorption and effective carrier separation are achieved. As a result, the modified C3N4 exhibits a significant enhanced degradation activity and the optimal rate constant of modified C3N4 for Acid Red 9 degradation is 5.83 times that of pristine C3N4. The work demonstrates the effect of structure modification in C3N4 for enhancing degradation activity.
The effect of interfacial engineering on the deactivation resistance of nickel-based catalysts for dry reforming of methane
Authors: Zhang Jinmiao , Zheng Mudi , Zhou Yuqing , Gao Xingyuan
Published: November 2021

Methane dry reforming reaction (DRM) can convert CO2 and CH4, two kinds of greenhouse gases with very stable chemical properties, to produce syngas, which can be used to synthesize valuable industrial products. Nickel-based catalysts have been widely used in DRM because of their low cost and good catalytic activity. However, nickel application is limited by such as high-temperature metal sintering, carbon deposition and catalyst poisoning, which restricts the industrial application in DRM reaction. Compared with single metal nickel, the selective doping of multi metals and supports shows higher catalytic activity and anti poisoning tolerance due to changing the chemical and structural properties of the catalyst by enhancing the alloy effect and the force between metal and support. This paper mainly reviews the catalysts with anti-coking, anti-sintering and anti-sulfur poisoning by tuning the metal-metal interaction and metal-support interaction (MSI) in DRM. The modification strategies in interfacial engineering and structure-performance relationship are discussed, and the existing difficulties and future development of Ni-based catalysts are proposed.
The influence of vapor on the particle transport in high humid neighborhood environment
Authors: Mei Dan , Xu Xuemei
Published: November 2021

The particle transport characteristics have a significant effect on the exposure of residents and pedestrians to traffic pollutants in the street canyon. Around the lakeside environment, the diffusion of water vapor affects the flow characteristics of the gas mixture, which has a considerable influence on particle transport in the street canyon. A computational domain containing water bodies from which droplets were emitted by evaporation, a lakeside avenue and architectural groups were constructed. The RNG k-ε turbulence model and discrete phase model were applied to study the velocity, pressure, density of the airflow and particle transport characteristics in the street canyon with the absolute humidity increase (AHI) of 0, 3.8×10-4 g/kg, 1.7×10-3 g/kg, 3.1×10-3 g/kg. The saturated vapor pressure on the surface of droplets was modified by the pressure correction equation, which can limit the evaporation rate of the droplets. The simulation results demonstrated that, the diffusion of vapor could reduce the airflow velocity and increase the air pressure and density. The particle concentration in the street canyon increased with the AHI. Most of the pathogens in the air are transmitted with the flow of particle, and the study has some guiding significance to prevent the transmission of viruses.
White-Light-Emitting Control via Lead-free Perovskite Material
Authors: Xie YueLin , Chen Tingxuan , Li Henan , Fang Shaofan
Published: November 2021

In recent years, the emerging lead-free halide perovskites are attracting great attention in the field of the optical detection and luminescence due to its inherent strong light absorption and high balanced carrier on transmission characteristics. This experiment attempts to explore the way of grinding to prepare the white light emitting materials that does not contain lead. Low dimensional lead-free copper-based halide luminescent materials are prepared by controlling the molar ratio of a series of lead-free perovskite materials Cs3Cu2I5 and CsCu2I5. As-synthesized powder samples are characterized by powder X-ray diffraction (XRD), photoluminescence spectrum (PL), photoluminescence excitation spectrum (PLE) and photoluminescence quantum yield (PLQY) and other characterization methods. We successfully prepare the white powder sample by controlling the molar ratio of reactants (CsI:CuI=1:3). We measure the Commission Internationale de l’Eclairage (CIE) chromaticity coordination of PL spectra for the samples which can be regulated by the ratio of reactants. Moreover, it is demonstrated that acetone can effectively promote the reaction of reactants. These findings make this material be a stable and environmentally friendly white luminescent material, which has the potential to be used in white LED applications.
Study on Crystallization Behavior of Polypropylene Induced by Nucleating Agent
Authors: Wang Lanhua , Liu Qi , Yu Haitian , Wu Xi , Xu Shufei
Published: November 2021

The melting and recrystallization behavior of -iPP crystal induced by β -nucleating agent was studied. A new type of α-modification has been developed by self-seeding process. The growth process of these crystals is just like “photographic development process.” Crystalline phase transformation and the memory effect caused by local order was observed during the melting and annealing process. A high temperature is sufficient to destroy the local order and the β-nucleating agent efficiently induces formation of β-form.
Luminescent Properties of a Novel Mn2+ doped 3CaO-CaF2-2SiO2 Glasses
Authors: Zhang Ning , Man Shiqing
Published: November 2021

The transition metal Mn2+ ions doped materials have been widely reported for the luminescent properties for its broad emission band from green to red due to the spin-forbidden 4T1→6A1 transitions. To investigate the luminescent properties of Mn2+ ions in cuspidine glass, the 3CaO-CaF2-2SiO2 glasses doped with different Mn2+ concentration were prepared with traditional melt-quenching method. The luminescence emission spectra, excitation spectra and luminescence decay curves were recorded and analyzed. The tunable broadband emission from orange to red was obtained. The luminescence intensity and lifetime of Mn2+: 4T1 level showed different quenching points with the increasing of Mn2+ concentration. All these results indicate that Mn2+ doped 3CaO-CaF2-2SiO2 glass could be applied as light conversion material for solid-state lighting applications.
Three-point bending study on the microscopic fracture behavior of pre-oxidized Cr-coated Zr-4 alloys
Authors: Du Mingyue , Wang Chenxue , Jiang Jishen , Ma Xianfeng
Published: November 2021

In this study, an in situ three-point bending test was carried out to study the mechanical properties and cracking behavior of the Cr-coated Zr-4 alloy considering the effect of pre-oxidation. The results showed that high temperature pre-oxidation led to the formation of intermetallic ZrCr2 at the coating/substrate interface and an α-Zr(O) layer beneath the interface. During the three-point bending test, the Cr coating and Zr-4 substrate showed good plastic deformation. However, the brittle intermetallic ZrCr2 diffusion layer exhibited cracks in the early stage, which accelerated the crack penetration to the Cr coating and the Zr-4 substrate, leading to the pre-failure of the pre-oxidized sample.
Effects of dodecyl benzene sulfonic acid between hydrate particles and droplets
Authors: Zhao Shuai , Li Mingzhong , Geng Kaili , Liu Chenwei , Wei Zhe , Wu Shuai
Published: November 2021

In order to understand the effect of Dodecyl benzene sulfonic acid (DBSA) on the aggregation mechanism of hydrate, the interaction between cyclopentane (CyC5) hydrate particles and droplets under different concentrations of DBSA and different temperatures was measured by micro mechanical force device (MMF). The mass concentration range of DBSA used in the experiment is 0.0001% ~ 0.05%, and the experimental temperature is 1°C and 5°C, respectively. The experimental results show that DBSA can effectively reduce the interfacial tension between oil and water, thus reducing the adhesion between hydrate particles and droplets and preventing hydrate aggregation. In the experimental concentration range, the higher the concentration of DBSA, the stronger the ability to reduce the adhesion. The adhesion can be reduced by 97.56% at 1°C and 90.95% at 5°C. The change trend of the adhesion with the concentration is almost the same at the two temperatures.
Preparation of high-temperature resistant and environment friendly dust suppressant
Authors: Zhou Yilai , Wu Lin , Tong Ling , Liu Ying , Yang Xiaoyu , Zhang Baoguo , Liao Zhiyuan , Chen Ao , Hu Ya
Published: November 2021

In order to make the grindability of the semi-coke better, some manufacturers choose to dry the semi-coke at a higher temperature after the preparation. The existing dust suppressants in the market fail due to the high temperature in the drying process, causing extremely serious dust in the plant, which greatly endangers the health of workers. A high-temperature resistant and environment friendly dust suppressant is developed to solve the above problem. This dust suppressant can exist stably at 120 °C, and it has excellent dust suppression performance.
Corrosion Study of Carbon Steel in Carbonated BUMEA-2EE Nonaqueous Solution
Authors: Liu Fang , Du Xiaoqian , Wang Lemeng , Fu Dong
Published: November 2021

Different effort has been attempted to reduce the equipment corrosion of CO2absorption using chemical solvents. In this paper, the corrosion of carbon steel in carbonated 2-(butylamino)ethanol (BUMEA)-2-ethoxyethanol (2EE) non-aqueous solution was studied by using a CHI602E electrochemical analyser. The polarization behaviour and corrosion rate of carbon steel in non-aqueous blends of BUMEA-2EE were investigated. The influence of temperature, the mass fraction of BUMEA (wBUMEA) and CO2loading (α) on the corrosion rate were clarified.
Study on the mechanism of hydrate adhesion on the surface of rocks and minerals
Authors: Wei Zhe , Li Mingzhong , Lu Yanchen , Liu Chenwei , Wu Shuai , Zhao Shuai
Published: November 2021

Natural gas hydrate is mainly enriched in the low temperature and high pressure environment such as the extremely cold permafrost zone and the polar continental shelf, which is a renewable energy with great development value. The analysis of the adhesion mechanical properties of gas hydrate on the surface of rock and mineral is of great significance for the correct evaluation and effective control of the influence of gas hydrate on sedimentary layers. In this paper, an experimental device for visualizing the adhesion of hydrate wall under atmospheric pressure was built to directly test the adhesion strength of hydrate on the rock wall. The influence mechanism of the microstructure of rock wall and the types of rock minerals on the adhesion strength of hydrate was studied. It was found that the adhesion strength of hydrate on the sandstone wall was greater than that of carbonate rock salt. The higher the surface roughness of rock and mineral, the higher the adhesion strength of hydrate.
Preparation of reduced graphene oxide and its application in chromium-free inorganic insulating coating for oriented silicon steel
Authors: Liu Ying , Wu Lin , Tong Ling , Yang Xiaoyu , Chen Ao , Zhou Yilai , Liao Zhiyuan , Zhang Baoguo , Hu Ya
Published: November 2021

In the fields of military industry, national defence and major engineering, oriented silicon steel is an indispensable material, but the chromium-containing insulating coating coated on its surface is harmful to the environment and humans. Due to poor performance, the industrialization of chromium-free inorganic coating is hindered. To improve the corrosion resistance of chromium-free inorganic insulating coating for oriented silicon steel, reduced graphene oxide (rGO) was prepared by the hydrothermal reduction method and added to the basic chromium-free inorganic insulating coating composed of small-particle silica sol, large-particle silica sol and aluminium dihydrogen phosphate to obtain rGO-containing coating. Scanning electron microscopy (SEM) and Raman spectroscopy were used to analyse the microscopic morphology and structural characteristics of rGO. Electrochemical impedance spectroscopy (EIS) and Tafel polarization curves were used to test the corrosion resistance of the coating. The results show that the prepared rGO has a multi-layer structure with a smaller size than graphene oxide (GO) and can be dispersed in water-based coatings. And rGO can reduce the corrosion current density of the coating by two orders of magnitude, and improve the corrosion resistance of the coating.
Research progress of carbon-assisted etching of silicon nanostructures
Authors: Yang Xiaoyu , Tong Ling , Wu Lin , Zhang Baoguo , Liao Zhiyuan , Chen Ao , Zhou Yilai , Liu Ying , Hu Ya
Published: November 2021

Silicon nanostructures are attracting growing attention due to their properties and promising application prospects in solar energy conversion and storage devices, thermoelectric devices, lithium-ion batteries, and biosensing technologies. The large-scale and low-cost preparation of silicon nanostructures is critical for silicon-based advanced functional devices commercialization. In this paper, the feasibility and mechanism of silicon nanostructure fabricated by non-metallic carbon catalytic etching, as well as the currently existing problems and future development trend are reviewed.
Analysis on Flow Field Characteristics of Airfoil in Pitching Motion
Authors: Yin Rui , Huang Jing , He Zhi-Yuan
Published: November 2021

Based on CFD, the flow field characteristics of NACA4412 airfoil are analyzed under pitching motion, and its aerodynamic characteristics are interpreted. The results show that streamline changes on the upper surface of the airfoil play a decisive role in the aerodynamic characteristics. The interaction between the vortex leads to fluctuations in the lift and drag coefficients. Under a big angle of attack, the secondary trailing vortex on the upper surface of the airfoil adheres to the trailing edge of the airfoil, resulting in an increased drag coefficient. Under a small angle of attack, the secondary trailing vortex can break away from the airfoil. The lift coefficient reaches the maximum value of 2.961 before the airfoil is turned upside down, and the drag coefficient reaches the maximum value of 1.515 after the airfoil is turned upside down, but the corresponding angles of attack of the two are equal.
Research on used power battery cutting parameters optimization for low carbon and high efficiency
Authors: Chen Jia , Jiang Zhigang
Published: November 2021

The cutting process of used power battery is a key step for recycling its materials, and it is energy-intensive and high carbon emission process. To reduce the carbon emissions of the used power battery cutting process, the relationship between the carbon emissions of the cutting process and its process parameters was analyzed based on the safety requirements. Next, the multi-objective optimization model for cutting process parameters is established with the goal of minimum carbon emissions and shortest cutting time, which takes into account the constraints of the cutting device’s and the safety requirements. For the strong nonlinear characteristics of the optimization model, an improved PSO algorithm is used to solve the model. A case study of cutting a certain type of used power battery is illustrated to verify the validity of the established model.
Study on Mutual Feedback Mechanism and Stability Control of Toppling Slope and Tunnels with High Excavation Rate
Authors: Zheng Huifeng , Zheng Shuo , Chen Yi , Wu Guanye , Zhou Yong
Published: November 2021

During the construction of large-scale hydropower projects in deep mountain gorge areas of the Western China, the difficulties, such as uncontrollable large deformation, great deformation caused by small disturbance, are often encountered in the process of implementation. In particular, due to the limitation of topography, geological conditions and the layout of structures, the slope and dense tunnel group with large section need to be excavated simultaneously in the toppling rock mass. The feedback action mechanism between slope and tunnel excavation is complicated and the deformation control of toppling rock is difficult, which leads to great challenges to engineering construction. In MW hydropower project in west of China, the intake slope, the spillway channel slope, four headrace tunnels, and the sand flushing tunnel, as well as the construction traffic tunnel are arranged in Huishi Ridge on the left bank, where two high slopes and six lager cross-section tunnels are simultaneously excavated and the excavation rate in the toppling deformation rock mass is over 50%, moreover, the lateral coverage thickness of tunnel body is less than the diameter of the tunnel, which leads to the great difficulty of stability control. The excavation stability and safe of the thin mountain ridge is the vital issue to the success of the whole project. Based on the study of the physical and mechanical parameters of toppling rock mass of MW HPP, the mutual feedback mechanism of toppling slope and tunnel group is revealed, an excavation method involving horizontal partitioning, vertical layering, reserving rock plug and reasonable skipping warehouse is proposed. Monitoring results shows that the slope and surrounding rock of the tunnels are stable during the operation period. The research of this paper based on the MW HPP can provide reference for other similar projects.
Thermodynamic Research on the Precipitation of Ti2O3, TiN and TiC in Continuous Casting of Titanium Microalloyed Steel
Authors: Zhao Tengfei , Zheng Xiang , Huang Dongjian , Zhu Zhenghai , Yin Zhihong
Published: November 2021

The composite precipitation of Ti2O3 + TiN during continuous casting has an important influence on the microstructure and properties of the slab. In order to study the precipitation conditions of Ti2O3, TiN and TiC second phase in titanium microalloyed steel, the solid-liquid phase line temperature, the initial precipitation temperature of different second phase, the equilibrium and actual solubility product of Ti2O3, TiN and TiC at different temperatures are calculated, and the precipitation rules of titanium microalloyed steel in liquid steel and two-phase region are analyzed. The results show that: Ti2O3 and TiN can precipitate in molten steel, and the precipitation order of Ti2O3 is prior to that of TiN, while TiC does not precipitate. Due to the enrichment of Ti, O, C and N in the liquid phase during solidification, the equilibrium precipitation conditions of Ti2O3 and TiN are reached when the temperature is lower than 1469°C of the liquidus, and the precipitation begins at the initial stage of solidification. When the temperature in the two-phase region is lower than 1332°C, the precipitation of TiC begins.
Research on fatigue failure mode and failure theory of rubber
Authors: Wang Zhanbin
Published: November 2021

The rubber products are usually used in the condition of periodically complicated stresses, and their anti-fatigue function is simultaneously dependent on their viscoelasticity and the emergence and propagation of cracks directly effecting on the life of rubber products. Therefore, the research on fatigue failure of rubber products has important significance to improve their durability and safety. The research on fatigue failure of rubber has important significance to improve the durability and safety of rubber products. The fatigue failure mechanism of natural rubber was explained from the point of molecular motion theory and phenomenological theory. The application of test research methods in the study of rubber fatigue microstructure and the influence of environmental factors on the fatigue properties of natural rubber were studied, and the future development direction of natural rubber fatigue was also forecasted.
Research on Application of Hydrocyclone Microbubbles Generator in Flotation of Oil-Water Emulsion
Authors: Wang Quan , Chen Yong , Huang Jiaxuan , Gao Bingcong , Chen Ying
Published: November 2021

With the improvement of environmental protection requirements, economical and efficient oily wastewater treatment methods have become a research hotspot. At the same time, the characteristics of microbubbles (large specific surface area, high zeta potential, rises slowly) make it very widely used in various fields, including the treatment of oily wastewater. There are many methods to generate microbubbles, and each method has its own applicable fields. In order to better apply microbubbles to the separation of emulsified, the experiment used a hydrocyclone to produce microbubbles. The ability of microbubbles to separate oil-water emulsions verified by the method of combining visual processing with oil content testing. The experiment shows that the hydrocyclone can generate a large number of small-sized microbubbles, and the microbubbles are stable in the emulsion for more than 30 minutes. In addition, the microbubbles can better float the emulsified oil and concentrate it on the water surface. After the treatment of microbubbles, the oily wastewater can be easily separated from oil.
Effect of Limestone Powder on Mechanical Properties of Engineering Cementitious Composites
Authors: Zhou Jianwei , Yu Baoying , Kong Yaning , Yang Wen , Cheng Baojun
Published: November 2021

The effect of limestone powder replacing fly ash on the mechanical properties of engineering cementitious composites was investigated. The results showed that the water demand of engineering cementitious composites due to partial replacement of fly ash by limestone powder, but the water demand of the system decreased when the replacement ratio reached 100%. The flexural strength of the specimen appears to decrease with increasing age due to incomplete replacement of lime powder. The toughness of the specimen can be significantly improved due to the complete replacement of fly ash by limestone powder.
Influence of Temperature Control of Coke Oven on Life Cycle of Refractories
Authors: Fang Hongming , Qu Likai , Wang Shijie , Han Jun , Wu Xiaoxiong , Cheng Xin , Zhang Lei , Che Peilin , Hu Anni
Published: November 2021

Different stages of the oven drying are analyzed by the theory of molecular diffusion and crystal change in oven drying process. It’s pointed that in order to ensure uniform expansion and gray seam integrity, the speed of spreading to the outside about within water should be in accordance with the speed of evaporation about surface moisture in the drying period, heating up too quickly will easily lead to extending drying period and destroying masonry rigor. The expansion of silica brick is mainly from the volume effect form with the transition between the allotrope in the expansion period, the heating rate of crystal transformation point must be strictly controlled. At the same time, quartz content should be higher, lesser residual quartz content will be better. The hot state engineering period is consistent with the construction schedule, the construction sequence can’t be reversed, and it is not recommended at this stage to extend the construction period. Effective control of the heating rate of the three stages above lays a solid foundation to extend the oven life.
Force Analysis of Logging Cable in Deep Well
Authors: Zhang Wenzhe , Feng Jiajia , Gao Shan , Wang Zhongzheng , Cheng Jiarui
Published: November 2021

With the increase of deep wells, high temperature and high pressure wells and complex wells, the demand for logging is also increasing. Wireline logging is an important technical means to obtain downhole data in the process of petroleum testing. This paper establishes a cable mechanics model by analyzing the main influencing factors of the cable force in the inclined well section or the vertical well section. Calculate the lifting power of the tool. Through logging calculation, the force change law of the downhole cable and tool string is obtained when the wellhead pressure changes.
Estimation of False Data Injection Attacks for Load Frequency Control Systems
Authors: Ye Jun
Published: November 2021

False data injection attacks (FDIAs) against the load frequency control (LFC) system can lead to unstable operation of power systems. In this paper, the estimation problem of the FDIAs for the LFC system in the presence of external disturbances is investigated. The LFC system model under FDIAs against frequency and tie-line power measurements is established. Then an attack estimation scheme combining the attack observer (AO) and technique is proposed to minimize the effect of external disturbance on estimation errors. The uniform boundedness of the state and attack estimation errors is proved using Lyapunov stability theory. Finally, a two-area interconnected power system is simulated to demonstrate the effectiveness of the proposed attack estimation algorithms.
Fracture Failure Analysis of the Energy Storage Spring of the Circuit Breaker in the 110kV Substation
Authors: Wang Jun , Huang Rong , Hu Haiqing , Cao Xianhui , Chen Junjun , Feng Chao , Liu Weike , Hu Yujing
Published: November 2021

Through a macro inspection, chemical composition analysis, hardness inspection, graphite carbon inspection and energy spectrum analysis, the reason for the break of the energy storage spring of the circuit breaker in a 110kV substation are analyzed. The results show that poor manufacturing technology and anti-corrosion technology of the spring are the main reason for its fracture. Corresponding control measures are put forward to avoid similar failures from happening again.
Off-line Parameter Identification of Permanent Magnet Synchronous Motor
Authors: Chen Ying , Chen Dongdong , Li Zongwei , Lei Hongdan , Zhu Hongguan
Published: November 2021

This paper first explains the necessity of off-line parameter identification of permanent magnet synchronous motors, and then introduces the identification methods and principles of the stator resistance, stator d/q axis inductance and back-EMF coefficient of permanent magnet synchronous motors. An identification method of stator d/q axis inductance injected with high frequency voltage is proposed. Finally, based on the MBD development model, the proposed identification method is modeled by Matlab/Simulink and the code is generated for experiments. The results verified the accuracy and feasibility of the proposed method well.