bluuebunny/crossref_metadata_2025 huggingface dataset:
Research and application on wellbore integrity technology for Integration of Oil Recovery, Well Completion and Drilling
Authors: Bai Xuemin , Yang Song , Yuan Xizhi , Xie Jiang , Li Weijie
Published: December 2019

Huabei oilfield has entered the middle and late periods of the development, and a series of problems such as casing damage, casing deformation, restricted measures and eccentric wear of staff and tube are gradually exposed in the development process[1,2], which affect the development benefit of oilfield, and the wellbore integrity is closely related to the development benefit. Therefore, in order to ensure the qualified wellbore conditions, huabei oilfield put forward the design concept of “Integration of Oil Recovery, Well Completion and Drilling”, the engineering design system of multi-professional coordinated and unified “Integration of Oil Recovery, Well Completion and Drilling” are constructed, the optimization design of drilling trajectory, casing and frac fluid system was carried out. The application shows that the design prolonged the life cycle of oilwell effectively, which of great significance for single well productivity improvement and benefit development.
Flocculation and sedimentation characteristic of coal slurry in coal preparation plant
Authors: Li Lingyue , Zhou Shenglun , Chen Feng , Qu Jiangjiang , Liu Chuan , Cheng Sibo
Published: December 2019

Flocculation sedimentation test was carried out on the coal slurry of the selected coal preparation plant. A mathematical correlation model of initial settling velocity, upper clarification turbidity and sediment volume with various influencing factors was established. The results show that: the initial settling velocity increases first and then decreases with the increase of flocculant concentration; when the flocculant concentration is 10g/m3, the initial settling velocity is the largest; the initial settling velocity increases with the increase of the mass ratio of coagulant and flocculant. The upper clarification turbidity decreases first and then increases with the increase of the flocculant concentration; when the flocculant concentration is 10g/m3, the supernatant has the lowest turbidity; the upper clarification turbidity decreases with the increase of the mass ratio of coagulant and flocculant. The volume of sediment increases with the increase of flocculant concentration, and increases with the increase of mass ratio of coagulant and flocculant.
Analysis of Industrial Metabolic Flux in Blast Furnace Ironmaking System
Authors: Xie Minchao , Zhao Gang , Chen Junwen , Cao Kunlun
Published: December 2019

Based on the method of industrial metabolic analysis, the methods is given in this paper. Taking the blast furnace ironmaking process of an iron and steel enterprise as an example, the material metabolic analysis of blast furnace ironmaking process is carried out. By using the calculation method of metabolic flux, the regulation model of industrial metabolic flux based on the principle of flux balance is constructed, and the material metabolic communication in the process of blast furnace ironmaking is carried out and quantity prediction. On this basis, the control method of material flux in blast furnace ironmaking process is put forward, which can provide energy saving and emission reduction measures for enterprises.
Research on rapid semi-quantitative determination of iron in pyrotechnics uesd for fireworks and firecrackers
Authors: Jun-yi Wu
Published: December 2019

This study discloses a method for rapid semi-quantitative determination of iron in pyrotechnic powder for fireworks and firecrackers based on energy dispersive X-ray fluorescence spectrometer (EDXRF), including the following steps: preparation of samples, establishment of testing methods, determination of the characteristic line fluorescence intensity values of Fe element in samples, and according to the measured fluorescence intensity values, the iron content in the pyrotechnic powder samples can be semi-quantitatively determined. The method of the study has the advantages that: (1) the method is simple to operate, and the method can be repeatedly called for testing. Only one new test method needs to be built before the sample test. After the method is established, the test can be repeated at different times without re-establishing the test method for each test. After the first establishment of the new test method, the entire test process only includes three steps: sample preparation, sample loading into the sample cup and on-board testing. (2) The detection period is extremely short. After the sample is prepared, the entire measurement process takes only about 2 minutes. (3) Labor intensity is very low and the requirements for operators are not high. (4) The method has good stability, good repeatability and high credibility.
Understanding the inconsistency between mechanism and rate constants of acetylene ozonolysis
Authors: Wang Dongtong , Zelin Wang , Zhang Shaowen
Published: December 2019

The reaction mechanism of acetylene with ozone was studied by using the complete active space self-consistent-field (CASSCF) and the CASPT2 methods. It was confirmed that the reaction follows the Criegee mechanism, yet a van de Waals complex was introduced in the mechanism. We found the master equation method is the key factor to accurately calculate the rate constants and Arrhenius parameters of this reaction, comparing to the results calculated by the traditional transition state method with steady-state assumption by Cremer which are about an order of magnitude smaller than the experimental data.
Research on clean energy complementary power generation and optimal operation in Yalong river basin
Authors: Zhang Xinshuo , Huang Weibin , Wang Feng , Chen Shijun , Guangwen MA
Published: December 2019

Based on the general situation and development status of Yalong river clean energy demonstration base, the typical wind power stations, PV power stations and hydropower stations in the downstream of Yalong river are selected for research. Firstly, the principle of wind power, photovoltaic power and hydropower complementarity was analyzed, and the complementary characteristics of this three kinds of power sources in a daily time scale were explored. Secondly, in order to maximize the consumption of clean energy, ensure the operation safety of the grid and protect the cascade hydropower benefits, a mathematical model was built with the objective of the minimum load tracking difference index and the minimum total amount of water abandoned in the dispatching period, which was solved by two-layer nested optimization solution. The results show that the cascade hydropower of Yalong river has the ability to regulate the fluctuation of wind power output in the basin. The three kinds of power supply bundled out can provide stable and high quality electricity for the grid. The last, a new strategy for cascade hydropower operation after complementation was proposed, which can promote the realization of low carbon power dispatching and the optimization of energy structure.
The marketization process of electricity purchase and power generation and its significance in China
Authors: Tang Chenghui , Zhang Fan
Published: December 2019

China’s electricity purchases and power generation have been subject to deterministic catalogue tariffs for a long time. With the continuous improvement of China’s electricity market reform, more and more parts of electricity purchase and power generation use market-based methods to determine electricity prices. This paper reviews the marketization process in China’s electricity purchase and power generation. In view of whether or not to participate in the electricity market, this paper classifies different types of electricity purchase and power generation in China. Finally, it summarizes the significance of China’s electricity purchase and power generation marketization.
Two Networking Algorithms Based on LoRa Communication Used for Private Network Construction in Energy Acquisition System
Authors: Yan Xu , Xuefeng Zhai , Weilian Shui , Jian Wang , Zhongxiao He
Published: December 2019

With the continuous improvement of acquisition quality, service quality, maintenance cost of energy acquisition system, downlink communication still lacks systematic solutions to the complex, changeable, new and weak planning application scenarios of underground garage charging pile, coal-to-electricity conversion, etc. This paper proposed two networking algorithms, BRN and MCN, based on LoRa communication used to construct the private network in energy acquisition system. With the long-distance characteristics of LoRa technology, a larger private network can be built quickly.
Chemical Analysis of High Moisture Content of Flue Gas Desulfurization Gypsum
Authors: Li Yin , Yuehua Feng , Yanyan Wang , Linhao Li
Published: December 2019

In order to solve the problem of high moisture content of flue gas desulfurization gypsum in coal-fired power plants, after eliminating the reasons of system equipment, chemical analysis of relevant samples was carried out by thermogravimetric analyzer, laser particle size analyzer, ICP and other instruments. Results show that the main reason for the high moisture content of desulfurization gypsum is the high magnesium content in limestone, which results in the faster nucleation rate of gypsum crystals and the difficulty of aggregation and growth of gypsum crystals. This increases the difficulty of dewatering gypsum with dewatering belt.
Degradation of antibiotics in water by salicylic acid modified carbon nitride photocatalytic material
Authors: Wang Hao
Published: December 2019

The misuse and abuse of antibiotics lead to water environment problems in many countries including China all over the world. There are many deficiencies in traditional ways of antibiotics degradation such as high cost, low removal efficiency, low degradation rate etc. In this paper, the modified carbon nitride was synthesized from urea and salicylic acid with thermal copolymerization. The XRD, FT-IR and TEM were used to characterize the structure and optical properties of the material. From the radical sacrificial test, the super oxide radicals were examined as the major radicals in the degradation process. The material provides a good application prospect for the photocatalyst treatment of antibiotic wastewater.
Design and Research of a Seawater Desalination Device Powered by Solar Energy and Wave Energy
Authors: Liu Yang , Chen Aiguo , Zhi Yun , Xiao Yaoyao , Zhao Yongtian , Fang Chaobin
Published: December 2019

A seawater desalination device powered by new energy sources is proposed against the high energy consumption in the fresh-water generating industry. The designed seawater desalination device utilizes the vacuum tube of its thermal piping to collect solar energy, uses the multi-effect distillation system to perform thermal desalination, and makes use of the Edinburgh duck to acquire mechanical energy and ultimately produces fresh water out of sea water. The safe and efficient device can provide fresh-water resources for a variety of offshore engineering.
Reliability Evaluation of Mechatronic Equipment Based on Evidence Theory
Authors: He Zhiyuan , Lv Weimin , Hu Wenlin
Published: December 2019

To solve the correlation problem in evidence theory, this paper proposes an evidence theory model based on Copula function and related reliability assessment methods. First, we establish a performance degradation model based on the Wiener process and calculate the PDF of the lifetime distribution. Secondly, the fuzzy C-means algorithm is used to discretize the probability density function and obtain the marginal basic reliability allocation (BPA). Finally, the fusion of multidimensional evidence variables is carried out using the improved synthesis rules based on Copula function. The example analysis shows that this method solves the evidence-related problems in traditional evidence theory, and it is more efficient than other methods in the literature.
Simulation on Penetration of Image Homing Rocket Projectiles in Steel Plate- Concrete Targets
Authors: Fang Shidong , Chen Dong , Li Yong , Wu Pan , Jiang Bin’an
Published: December 2019

In order to study the penetration performance of image homing rocket projectile in steel plate-concrete targets, firstly, according to the characteristics of projectile and target, the material constitutive models and state equation were constructed, numerical models were built and the penetration was simulated with the software of LS-DYNA. Then, on the basis of verifying the accuracy of penetration simulation models, penetrations in two typical steel plate-concrete targets were simulated under the conditions of different slant angles. The simulation results show that the rockets can penetrate through the steel plate-concrete targets. Meanwhile, the force, velocity and penetration performance of the projectile were greatly affected by the steel plate in the process of penetration, and the impact, collapse and pit opening effect on the concrete covered by the steel plate were not obvious. In a word, the image homing rocket projectile has good penetration performance in steel plate-concrete targets, which can meet the tactical and technical requirements.
Fluid-structure coupling topology optimization based on added mass method
Authors: Wang Xudong , Ren Junpeng , Wang Deshi
Published: December 2019

A wet model topology optimization method based on added mass method and bidirectional evolutionary structure optimization algorithm is proposed to maximize the natural frequency of fluid-structure coupling system. The fluid-structure coupling equation of the finite element method and the sensitivity formula of the element are analyzed simultaneously, and then the coupling optimization model is established. Under the constraints of structure volume, the weighted natural frequencies of single-objective and multi-objective of the coupled system are maximized to optimize the underwater coupled structure. The numerical results show that the evolutionary methods can be applied to this kind of problem effectively and efficiently. Besides, the optimization results of cases have smooth boundaries and the numerical stability of the optimization algorithm is good. Under constant volume constraints, the single-order natural frequency is increased by more than 380%. The results of multi-objective weighted optimization show that the weighted coefficients are final. The larger the weighting coefficient is, the closer the topological form is to the optimal result of the model.
Flexible micro-perforated panels prepared by CNC machining
Authors: Xie Dongyue , Tang Xiaoning , Hu Ming , Kong Deyi , Qian Yujie
Published: December 2019

With the advantages of light weight, thin thickness and environment friendly, the micro-perforated panel (MPP) has been widely studied for noise reduction. Maa’s model pointed out that the MPP could obtain higher sound absorption over broader frequency band when the perforations were reduced to less than 100 μm. However, it is challenging to manufacture MPPs with the aperture of approximate 100 μm, thus its potential application has been restricted. In this study, we used a computer numerical control (CNC) milling machine to process MPP. Four different kinds of raw materials including paperboard, polyethylene terephthalate (PET), polyvinyl chloride (PVC), and polycarbonate (PC) were taken to prepare micro-perforated panels (MPPs). It has been indicated that MPPs with good sound absorption properties were successfully prepared by this facile method.
Research on Fatigue Life Prediction Method of Tractor Frame
Authors: Sun Liang , Yuan Zhengwen , Zhu Shumin
Published: December 2019

Aiming at the phenomenon of a certain type of tractor frame batch fatigue damage during the three-package period, the fatigue point and damage life of frame are predicted based on finite element method and linear fatigue damage theory in this paper. The stress at each node of the frame structure is acquired through the inertial release analysis of finite element model. The correction coefficient of the simulation model is determined by correlating the virtual strain of the frame with the measured strain. Based on the measured road load, finite element analysis results and material S-N curve, the fatigue life of the frame is calculated, and the severe fatigue damage area is obtained. The simulation results are consistent with the actual statistical results.
Analysis on Data Characteristic and Mechanism of Wind Vibration Disaster of Power Transmission Line
Authors: Peng Li , Bin Liu , Tong Li , He Liu , Yongfeng Cheng , Danyu Li , Jingchao Wang , Jialun Yang , Xiangze Fei , Kunpeng Ji , Bin Zhao
Published: December 2019

In this paper, characteristic identification and mechanism analysis on wind vibration disaster of power transmission line are carried out by using the data driving method. To provide technical support for prevention and control of wind vibration disaster to power transmission line, statistics are made in this from three dimensions i.e meteorology & geology, line structure and disaster characteristics to the wind vibration data of power grid conductors. Then frequency distribution characteristics of wind vibration disasters for conductors under different parameter conditions has been analyzed, and the correlation between various factors and wind vibration disasters according to analysis results has also been discussed.
Application of Discrete Fracture Network Model in the Simulation of Massive Fracturing in Tight Oil Reservoir
Authors: Ming He Chun , Zhi Shi San , Zhanghui  , Shuai Li , Jin Chen , Ning Cheng , Duanguifu
Published: December 2019

Massive fracturing technology can form a complex fracture network and a large drainage area by multi-stage/multi-cluster perforation and injection of low viscosity fluids such as silckwater.the traditional bi-wing planar model is not applicable in the simulation of massive fracturing, and a new network model is needed. The pseudo-three-dimension (P3D) Discrete Fracture Network (DFN) model are based on self-similar solution methodology, and the fracture characteristics are then calculated numerically. we performed a comparison between DFN model and Cluster Facture model through the integration of rock mechanics, well logging and micro seismic detection technology. After the mini-fracture analysis and closure analysis, parameters like instantaneous shut-in pressure (ISIP), closure pressure and reservoir permeability were obtained. Based on these parameters, pressure history match and SRV match were performed, the result shows that DFN model works better than the Cluster Fracture model in the matching. The research proves the feasibility of DFN model in the simulation of massive fracturing in tight oil reservoirs.
A Review on the Impacts of Building Energy Consumption with a Focus on Outdoor Thermal Environments and Residents’ Habits
Authors: Cui Haibo
Published: December 2019

Energy consumption is becoming a crucial economic issue and an unsolved priority problem for policymakers around the world. The demand and supply of unsustainable energy sources significantly influence family budgets and international relations. Currently, the energy consumption is becoming an increasingly important index in the building construction. This article analyzes building models under different conditions to explore factors influencing building energy consumption in outdoor thermal environments and variables attributed to different local habits.
Application of Static Bias Game in Decision Making of International Highway Project Bidding
Authors: Lin Tao , Li Jinbei , Zhang Yang
Published: December 2019

It is an urgent and practical need for international contractors to make a thorough study of the decision-making of international highway project bidding. This paper studies the application of static Bias game model in the international project bidding which provides reference for the reasonable price decision.
Discussion on Parameter Value and Application of Foundation Bearing Capacity Calculation Formula in Code for Design of Building Foundation
Authors: Zheng Qiwen
Published: December 2019

Article 5.2 of the Code for Design of Building Foundation gives the calculation formula of foundation bearing capacity. Some parameters in the calculation formula have the same symbols in front and back references, while the meanings represented by the parameters are different, resulting in the possibility of misuse by designers in the actual application process. According to the principle of soil mechanics, this paper discusses the situation that some parameters in the calculation formula of foundation bearing capacity are easily confused, which has certain reference value for correctly understanding the application of the calculation formula of foundation bearing capacity in foundation design.
Development of Building Information Modelling in China: A Review of Policy Trends
Authors: Yang Yingnan , Zhang Yidan , Yuan Lin
Published: December 2019

Currently, compared with the technical support needed for adopting Building Information Modelling (BIM), the scholars didn’t pay sufficient efforts on sociology. This paper examines developments of BIM in the architecture, engineering, and construction (AEC) industry in China, with a particular focus on the policy support for government-industry linkages. The paper shows how different regions in China have responded to the policy initiatives, and suggests that there have been some movements towards regional diversity for the developments of BIM in China. However, questions remain as to the development and potential of truly regional governance structures for BIM and the role of universities.
Effect analysis of vacuum prepressing reinforcement of soft soil foundation
Authors: Liu Wenbin
Published: December 2019

The supercharged vacuum pre-pressure method is to increase the supercharge system on the basis of the direct vacuum pre-pressure, and to increase the pressure in the middle of the vacuum process, thus achieving the goal of saving efficiency and increasing construction costs. Based on the reinforcement project of a blowout foundation in Lianyungang, this paper analyses the process of soil surface subsidence, pour water pressure, stratified subsidence and groundwater level when the soft foundation is reinforced by supercharged vacuum prepressing method by field test method. The paper will provide data support for future actual projects.
Design Method of The New Damping Energy Dissipation Corrugated Steel Plate Shear Wall System
Authors: Duan Wen Xu , Peng Xiao-Tong , Yang Ao , Lin Chen
Published: December 2019

In order to improve the lateral stiffness of the steel frame, natural anti-buckling corrugated steel shear wall was combined with mild steel dampers, forming a new damping energy-dissipation corrugated steel plate shear wall system (DCSW). The design method of the DCSW system was proposed based on plastic analysis. To study the seismic performance of this system, the nonlinear FEM of the DCSW system was established by ABAQUS, and the analysis on bearing capacity and energy dissipation capacity was carried out. The results showed that the DCSW designed by this method had high lateral bearing capacity and energy dissipation capacity. The lateral ultimate bearing capacity increased by 50% and lateral displacement reduced by 43% with corrugated steel plate shear wall and mild steel dampers.
Application of Self-feed-back System in Dewatering-Recharge Engineering of Foundation Pit
Authors: Xiangdong Song , Guojian Miao , Chengsong Qu
Published: December 2019

The self-feed-back system consisted of information acquisition system, information processing system and control system is applied in a complicit dewatering-recharge engineering of foundation pit. This self-feed-back system is made up of wireless monitoring devices and electronic control units. The application of self-feed-back system in Heyan-road-crossing-river-passage shows good serviceability in actual project.
Comparison and Selection of Construction Methods for Shallow and Submerged Large Section Tunnels in Urban Metro
Authors: Bo Wu , Ming Lu , Wei Huang , Jie Xu , Zhongjian Nong
Published: December 2019

Shallow-buried and Deep-Excavated large-section tunnels in Urban Metro have many characteristics, such as large span, complex construction procedures, multiple disturbances to surrounding rocks, and difficult to control ground subsidence. In the process of tunnel construction, the surrounding rock geological conditions and construction procedures have a very important impact on the stability and stress distribution of the tunnel. Based on the South limb project of Xiejiacun entrance and exit section of Tiantongyuan East Station of Beijing Metro Line 17, the applicability of dynamic partition method (DPM) and double-sided pilot excavation method is studied by numerical simulation. The ground subsidence, convergence point deformation, surrounding rock stress, initial support stress and extrusion deformation of palm face are taken as the judgment basis for analysis. The conclusions of this paper are as follows: the surface settlement, vault displacement and surrounding rock stress of DPM method are smaller than those of double-sided guide tunnel method, so it is concluded that DPM method is more suitable for this project; however, the difference of displacement and internal force between DPM method and DPM method is even slight, but when DPM (10) and DPM (15) are used in the construction of right guide tunnel, the internal force and displacement will change abruptly and can be strengthened appropriately. Finally, the deformations of the face during the construction of three construction methods are discussed to verify the feasibility and safety of DPM method, which provides a basis and guidance for the smooth implementation of the project and can be used as a reference for similar projects.
Research on Deformation Control Technology of Broken Soft Rock Pre-mining Roadway
Authors: Hao Wandong , Tao Du
Published: December 2019

This paper takes the right third pre-mining roadway of Double-river Coal Mine as the research object. Based on the analysis of the deformation law of soft rock broken roadway, a composite support technology scheme combining one-time reinforcement support and surrounding rock grouting reinforcement scheme is proposed. The application shows that the deformation of the composite support roadway is significantly lower than that of the conventional support roadway used in the same environment. The deformation of the roadway is effectively controlled, which greatly reduces the amount of repair and maintenance of the roadway, and achieves safe mining of the working face.
Research on the method of quickly comparing the quality of Aluminium Powder for fireworks and firecrackers based on energy dispersive X-ray fluorescence spectrometer (EDXRF)
Authors: Jun-yi Wu
Published: December 2019

This study discloses a method for quickly comparing the quality of aluminum powder for fireworks and firecrackers based on energy dispersive X-ray fluorescence spectrometer (EDXRF), including the following steps: preparation of samples, establishment of detection methods, determination of the characteristic line fluorescence intensity values of Al element in samples, and according to the measured fluorescence intensity values, the aluminum content in the two aluminum powder samples can be directly compared and determined. The method of the study has the advantages that: (1) the method is simple to operate, and the method can be repeatedly called for testing. Only one new test method needs to be built before the sample test. After the method is established, the test can be repeated at different times without re-establishing the test method for each test. After the first establishment of the new test method, the entire test process only includes three steps: sample preparation, sample loading into the sample cup and on-board testing. (2) The detection period is extremely short. After the sample is prepared, the entire measurement process takes only about 2 minutes. (3) Labor intensity is very low and the requirements for operators are not high. (4) The method has good stability, good repeatability and high credibility.
Numerical simulation of thin film flowing down a vertical uniformly heated plane using the regularized weighted residuals model
Authors: Jiahui Zhao , Riqiang Duan
Published: December 2019

With the developed three-dimensional Regularized Weighted Residuals Model (RM), discussion on its accuracy and simulation work are conducted. It is shown that for small to moderate Reynolds number, the accuracy of RM decreases with increasing Marangoni number and decreasing Biot number of the plane. The streamwise error ratios are larger than spanwise ones and reach a maximum when Reynolds number equals 3, which is due to underestimate of Marangoni instability. The increase of Reynolds number or introducing streamwise most unstable disturbance makes film duration time longer. With increasing Reynolds number, the early stage of wave evolution becomes faster and ripples are more intensive; the final pattern is more unstable and disordered. Heat transfer efficiency reaches two peaks with increasing Reynolds number, one due to the interaction between thermal condition and flow rate, the other due to film no-rupture. Introducing streamwise most unstable disturbance makes the early stages of wave evolution longer and wave amplitude smaller in later stages. Unless Reynolds number is small enough, heat transfer efficiency decreases with the introduction of streamwise most unstable disturbance.
Application of the DOC-DPF Integrated Exhaust Particle Treatment Device for New Marine Diesel Engines
Authors: Tan Weiwei G , Aiguo Chen , Fengyang Zhang , Jinxi Zhou
Published: December 2019

Based on the analysis of the diesel engine post-processing technology line, a DOC-DPF tail gas treatment device is proposed. The exhaust system of marine diesel engine is reformed, the particulate matter purification test is carried out in the exhaust system installation DOC-DPF tail gas treatment device, and the exhaust particulate matter of the marine diesel engine is detected by the automatic smoke tester and other instruments. The results show that the new ship exhaust particulate disposal device can effectively reduce particulate emissions from ship exhaust and is suitable for ships.
Study on the Manufacturing Technology of Guangdong Hand-made Paper
Authors: Zhou Zhong , Xiaopeng Peng
Published: December 2019

Traditional paper-making technology is one of the four great inventions in ancient China. The paper is make by hand and it is found in many areas of Guangdong. Guangdong hand-made paper is mostly used as gods paper, which has special requirements for quality. In order to study Guangdong paper-making technology furtherly, and provide scientific reference for its development, we combed around the factors of materials, tools and processes through experiments, summarized and checked the historical data, then analyzed thirteen processes, such as chopping bamboo, crushing bamboo, beating pulp, papermaking, loosing paper, drying paper and so on. These processes contain rich creative wisdom and are valuable historical heritage. Guangdong hand-made paper technology coexists harmoniously with local environment, and has handed over part of the process to machinery, but its industry scale is small and its economic benefits are not high. It will face the situation of no successor and technical fault. We need to develop Guangdong hand-made paper from the perspective of culture and tourism.
Fracture analysis of casting connector for power grid equipments
Authors: Wang Jun , Feng Chao , Xie Yi , Lian Hu , Long Yi , keLi Deng , Liu Weike , Ouyang Kejian
Published: December 2019

Various failures of casting connector were discussed here. In order to analyze the failure reasons of different samples, a series of tests were carried out, such as macro check, metallographic observation and X-ray penetration method. It turned out that the material defect, casting defect and improper heat process are assigned to be the main reason, respectively. In addition, the corresponding countermeasures were also proposed to improve the quality of power grid equipments.
Study on Constitutive Equation of Cumulative Damage of HTPB Propellant
Authors: Wang Xin , Zhao Ruyan , Yang Ming
Published: December 2019

In order to analyze the interaction of creep and fatigue of composite solid propellant, and provide the basis for calculation of cumulative damage and reliability analysis of the solid rocket motor during the period of storage, the constant stress loading destruction experiment, constant stress amplitude reciprocating tensile experiment and interaction experiments are carried out, then the damage cumulative equation is fitted by the least squares method and also be verified. The results show that there is a logarithmic linear relationship between the loading stress and the creep failure time and the repeated tensile failure times. The verification illustrates that the damage equation parameters can reflect the cumulative damage of propellant well, and the error is less than 10%.
Study on negative Poisson’s ratio structure with low porosity
Authors: Cai Yiqing , Zhu Yongsheng , Yan Ke , Yuan Qianqian , Hong Jun
Published: December 2019

Most two-dimensional negative Poisson’s ratio structures are highly porous, resulting in insufficient structural bearing capacity and only for small strain conditions. In this paper, the simulation method is used to prove that the low porosity and negative Poisson’s ratio structure with concave hexagon has “incremental” behavior, and then the correctness of the simulation model is verified by experiments based on digital image technology (DIC). In addition, the effect of unit cell parameters on the negative Poisson’s ratio at the same porosity is studied. The results show that at the same porosity, the length of the unit cell has the greatest influence on the Poisson’s ratio, and the longer the unit cell, the smaller the Poisson’s ratio; at different porosity, the larger the porosity, the lager the Poisson’s ratio.
Separation performance of hydrocyclone on emulsified oil wastewater floc
Authors: Zhang Ting , Wang Xuesheng , Chen Qinzhu
Published: December 2019

In order to improve the separation effect of emulsified oil wastewater flocs, a new separation method was proposed, which used a hydrocyclone to separate emulsified oil flocs. In this paper, the velocity field, pressure loss and floc volume distribution of the two hydrocyclones were studied by numerical simulation, and the difference of the separation performance of two different structures was investigated. The results show that the separation efficiency reaches to 81.7% and 78.9% respectively; the single cone cyclone has smaller pressure loss and energy loss under the same processing capacity; as the particle size of the floc increases, the separation efficiency of the two hydrocyclones increases. This simulation provides a reference for deep treatment of emulsified oil wastewater.
Research on synthesis and properties of early strength polycarboxylate superplasticizers with different lengths of side chain
Authors: Lai Guangxing , Fang Yunhui , Shao Youzhe , Chen Zhanghua , Guo Yuanqiang
Published: December 2019

A series of early-strength polycarboxylate superplasticizers with different lengths of side chain were synthesized by methyl allyl polyoxyethylene ether (HPEG) as macromonomers with different molecular weights. The structural parameters of polycarboxylate superplasticizers were calculated by gel permeation chromatography method. The performance of the synthesized samples were characterized by hydration heat, X-ray powder diffraction and concrete test. The results show that the longer the side chain be, the better the early strength effect be, when the side chain length is greater than 67.64, the early strength of the synthesized polycarboxylate superplasticizers are better than that of a foreign multinational enterprise.
Research on Arc Spot Welding of T12 Steel
Authors: Wang Yan
Published: December 2019

This paper mainly studied the microstructure change and hardness change of manual arc spot welding of T12 steel before and after post weld heat treatment. The experiment results showed the weld microstructure of J422 and J506 electrodes, which were common structural steel electrodes, were similar under different welding current. The weld microstructure of D256 wear resistance electrode were significantly different from those of structural steel electrodes. The hardness of spot weld before heat treatment had little change except for wear resistance electrode. The hardness of wear resistance electrode was the highest under different welding current before heat treatment. After quenching, the microstructure of spot weld were changed, the dendritic crystal disappeared and the hardness were generally improved. The microstructure and hardness of structural steel electrodes and wear resistance electrode before and after heat treatment were greatly different, which were caused by the different content of carbon and alloying elements of electrodes.
Electrical properties of cement-based composites with highly dispersed carbon nanotubes
Authors: Qin Jie , Li Yanwen , Qu Jian , Sun Zhipeng , Wang Bo , Zhang Weidong
Published: December 2019

In this paper, the effects of dispersion of multi-walled carbon nanotubes (MWCNTs) on the electrical properties of cement-based composites were systematically investigated. Six different types of surfactants were selected to disperse MWCNTs in cement by sonication, and the effect of ionic nature of surfactants on the electrical resistivity of cement-based composites was investigated. Additionally, experiments were carried out to investigate the effect of dosage of MWCNTs on the piezoresistivity of cement composite under cyclic compressive loading. The results show that the ionic nature of the surfactant influence the electrical resistivity of cement-based composites obviously. Furthermore, adding MWCNTs into cement-based composites is justified to improve their conductivity and the repeatability of piezoresistivity.
Assess and Optimization of Automatic Generation Control Performances for Thermal Power Generation Units
Authors: Gao Song , Lu Kuan , Yan Qing , Sun Mengmeng , Yuan Sen , Xin Gang , Wang Jin , Wang Ming
Published: December 2019

Automatic generation control (AGC) plays an important role to maintain real time power generation and load balance, and to ensure the quality of power supply. Power system requires each power generation unit to have satisfactory AGC performance. In addition to the design of AGC control strategy, the characteristics of power generation equipment also affect its performance in AGC control. This paper introduces the assess index of AGC performance of power unit, and analyzes the reasons for the poor AGC performance. Based on the AGC control strategy of thermal power units, the paper proposes an optimization method to improve assess index of AGC performance. Through the implementation of typical industrial case studies, the effectiveness of the proposed method is validated.
Research progress of steel tube rubber concrete
Authors: Tong Shiyu , Liu Yanhua
Published: December 2019

As a new form of concrete-filled steel tube, this paper focuses on the experimental research of the axial pressure performance of steel tube rubber concrete members in recent years, explains and summarizes related research results of hysteresis behaviors and seismic performance. Then further work to be carried out is listed. Finally, the possibility and development trend of its application in practical engineering is discussed.
Research on the Calculation Method of Axial Compression of Round-end Concrete-filled Steel Tube
Authors: Wang Erlei , Xie Jianxiong , Ma Xiaochun
Published: December 2019

Round-end concrete-filled steel tube (RCFST) columns have been applied to bridge structures. There is not the formula of RCFST under axial load in code. Based on the unified theory, the basic form of strength and stability capacity correlation equations of concrete-filled steel tube under axial load is obtained through the theoretical derivation. The formula results compared with finite element simulation results show results are in good agreement.
Research on seismic design method of a beam-column joint in reinforced concrete space frame
Authors: Cui Yanwei , Li Zhenbao , Song Kun , Ma Hua , Tang Zhenyun
Published: December 2019

Earthquake action is multi-dimensional and random. Under bidirectional horizontal direction loading, the seismic capability of beam-column joints in reinforced concrete (RC) frame may be lower than the design capability under unidirectional main direction loading. Detailed calculation methods for the shear bearing capability and shearing performance of RC space joints in frames under bidirectional horizontal direction loading have not been reported. In this work, the shear mechanism and internal force calculation method of an RC space joint under bidirectional horizontal direction loading are analyzed. Furthermore, a shear capacity calculation model is established based on the strut-and-tie model. The prediction of the shear capability in this work are in good agreement with the reported experimental results. This study provides a design method for the seismic design of RC space frame joints, and provides a supplement for the seismic design method of RC space frame with “strong joints and weak members”, when they are subjected to bidirectional horizontal direction loading at the same time.
RETRACTED: Fatigue characteristic and life test of reinforced concrete T girders under cyclic loading
Authors: Zhang Jinquan , Bai Bing , Zhao Shangchuan , Zuo Xindai
Published: December 2019

Aiming at the issue of reinforced concrete girder fatigue, a typical T shaped scale model girder form is selected as the test specimen based on the real structure drawings. On the basis of designing test program reasonably, 7 same batch test girders are loaded with different constant cyclic loading amplitude. Thus according to the test data, girder failure mode, fatigue life, mechanical property evolution law as well as rebar S-N curve is discussed systematically. The result indicate that the longitudinal rod fracture is the domain failure mode of girders, which can finally induces whole specimen rupture brittlely. The mode is clear and definite in the observation. On account of all observation, the longitudinal rod stress range is more regular and stable, which seems suitable for life evaluation. Using the data obtained above, the rod S-N curve equation is calculated by linear fitting method. Result shows the data fit well and all the data lie within the normal range of deviation, which may reveal the law between cyclic load and girder fatigue life.
Research on the method of quickly identifying the types of firecracker based on energy dispersive X-ray fluorescence spectrometer (EDXRF)
Authors: Jun-yi Wu
Published: December 2019

This study discloses a method for rapidly identifying types of firecracker based on energy dispersive X-ray fluorescence spectrometer (EDXRF), including the following steps: preparation of samples, establishment of detection methods, determination of the characteristic line fluorescence intensity values of Cl and Al elements in samples, and identification of types of firecracker based on measured fluorescence intensity values. The method of the study has the advantages that: (1) the method is simple to operate, and the method can be repeatedly called for testing. Only one new test method needs to be built before the sample test. After the method is established, the test can be repeated at different times without re-establishing the test method for each test. After the first establishment of the new test method, the entire test process only includes three steps: sample preparation, sample loading into the sample cup and on-board testing. (2) The detection period is extremely short. After the sample is prepared, the entire measurement process takes only about 2 minutes. (3) Labor intensity is very low and the requirements for operators are not high. (4) The method has good stability, good repeatability and high credibility.
Prediction of Agricultural plastic agricultural plastic film use based on combined prediction model
Authors: Chen Jingmin , Li Fu , Wang Changbao , Sun Yanbin
Published: December 2019

Although increasing the yield of crops, the large-scale use of agricultural plastic film in agricultural production, has caused damage to the ecological environment. This paper analyzes the current situation of the use of plastic agricultural plastic agricultural plastic film in China from 1999 to 2015. The GM(1, 1) model and the ARIMA(0, 2, 0) model are used to predict the mulch usage, and then the optimal weight combination method is used to obtain the grey-time series combination prediction model. The results show that the accuracy of synthetic prediction model is higher than that of the single model and has better applicability. The prediction results of the combined model can be used as a reference for the scientific use and management of agricultural plastic film in China.
Preparation and characterization of a new type of 304 stainless steel metalocking key
Authors: Ge Shaoliang , Wang Yaning , Song Wendong , Ji Lili , Cai Lu , Zhang Yuejun
Published: December 2019

The preparation process of metalocking key from 304 stainless steel was studied, and the mechanical properties of raw materials and metalocking key were studied. It is found that after this preparation process, the hardness of metalocking key increases by more than 20%, the tensile strength increases by more than 50%, the yield strength increases by more than 120%, and the elastic limit increases by more than 50%. Finally, scanning electron microscope (SEM) element analysis and metallography were used to characterize the microstructure analysis. It indicated that much of the austenitic stainless steel is converted to martensite due to cold rolling, which led to the significant strengthening of metalocking key properties.
Research on Modeling and Characteristic Parameters Consistency of Retired Lithium Power Batteries
Authors: Li Lifu , Li Jifei
Published: December 2019

For retired power batteries, it is difficult for single cell to meet the power requirements, and there is a problem of poor consistency between multiples. Therefore, re-grouping and consistency assessment are required for cascade utilizaton of retired batteries. In this paper, the remaining capacity test and HPPC test of retired lithium power batteries were carried out. And then the consistency of characteristic parameters of retired batteries under different SOC conditions was compared and analyzed based on capacity, internal resistance and other parameters. The results show that as the battery discharges, the ohmic internal resistance increases, and the consistency of polarization resistance and polarization capacitance are obviously deteriorated. Therefore, it is more reasonable to group them into consistent groups according to the electrochemical parameters of retired batteries at high discharge depth. Moreover, there is no strong correlation among the characteristic parameters such as open-circuit voltage, internal resistance and capacitance. Multiple parameters are required to evaluate the consistency of retired lithium batteries.