bluuebunny/crossref_metadata_2025_split huggingface dataset:
Online measurement of distributed capacitance in distribution network
Authors: Zhang Xiuhua 
Published: November 2020

Abstract
The distributed capacitance current of distribution network is the main factor of single-phase grounding current. In the current engineering, the distributed capacitance current is mostly measured by testing the distributed capacitance. Using the volt and ampere relationship of capacitor element can be indirectly realizing the test of distributed capacitance current. Most of the existing distributed capacitance measurement methods use the total impedance of the system to replace the distributed capacitance, which is easily to cause measurement error. Based on the analysis of the distribution network operation, this paper proposes an online measurement technology of distribution network which can precisely test the distributed capacitance. The physical engineering model is established, and the simulation research and design is carried out. The research shows that the online test technology of distributed capacitance can control the test accuracy below 1%, which can effectively make up for the deficiency of the existing distributed capacitance testing technology. It can realize the online detection of the distributed capacitance current of the distribution network, and ensure the operation safety.
Research on Diagnosis and Evaluation of Power Grid Enterprise Management Development Based on Combined Weight TOPSIS Theory
Authors: Du Ying , Wang Chao , Jie Jiao , Zhang Jiyuan , Chen Chao 
Published: November 2020

Abstract
At present, the operation and management of power grid enterprises is facing a complicated situation. Facing the new market-oriented reform situation and development trend, power grid companies must strengthen the awareness of input and output efficiency, fully integrate the key factors that determine investment and cost allocation and the evaluation results of enterprise production and operation, and do a good job in production and operation and grid development. This paper takes the county companies in the S area as the empirical analysis object, proposes a power grid management development evaluation index system, and combines the analytic hierarchy process(AHP) and the entropy weight method(EWM) to determine the weight, uses the TOPSIS theory to comprehensively evaluate the actual situation of the county companies, and through comparative analysis, The rationality of the indicator system and evaluation method is verified, and it can provide support and reference for further improving the level of fine investment management.
Eddy Current Testing in Service of the Boiler Heating Surface Tube Elbow in Thermal Power Plants
Authors: Liu Yunlong , Xie Ameng , Shen Dingjie , Yang Xiangwei 
Published: November 2020

Abstract
According to the characteristics of closed ends, tight tube screen and narrow testing spaces of the eddy current testing in service of the boiler heating surface tube elbow in thermal power plants, an external placed saddle eddy current testing probes which could be used to test the small diameter austenitic stainless steel tube elbow was designed. Then the comparative sample tube was processed in accordance with the eddy current testing technical standards. Through the sample testing and the applications in thermal power plants, the results show that the designed saddle-shaped eddy current detecting probe device has high detection sensitivity and reliability for linear defects above 0.2 mm and hole defects above Φ1.4 mm. It can realize the non-destructive testing in service of the austenitic stainless steel tube elbow, which has more serious oxidation, corrosion and more focused stress.
Study on Line Loss Status Classification Based on Decision Tree
Authors: Haibo Tan , Bingxiang Luo , Mouhai Liu , Guang Guo , Xiong Xie 
Published: November 2020

Abstract
Line loss rate is the ratio of power loss to power supply in a certain period of time, and it is an important index to assess the technical economy of power grid. In recent years, with the increasing scale of power grid construction and the aging of power lines, the traditional monitoring methods with simple logic judgment can not meet the accurate judgment status of line loss, so it is urgent to effectively improve the lean management level of transmission and transformation line loss abnormality. In order to realize the automatic classification of line loss anomalies machine learning algorithm is proposed, the paper takes 1500 transmission line loss data as training samples, builds a line loss anomaly classification model based on decision tree, and realizes the accurate classification of line loss anomaly causes. Meanwhile, the paper uses KNN, support vector machine and decision tree algorithm to identify the anomaly for comparing the accuracy of different machine learning algorithms, and uses MATLAB software to verify the algorithm. The experimental results show that the comprehensive the recognition accuracy of decision tree for line loss anomaly is the highest, reaching 88.9%, 60% for support vector machine and 82% for KNN. This is of great significance to the realization of lean line loss management and has a high engineering value.
Classifying and coding system of turbine parts based on internal and external codes
Authors: Ma Lyuzhou 
Published: November 2020

Abstract
Based on the smooth implementation of PDM in enterprises, this paper focuses on the system structure of classification and coding system, puts forward the concept of internal and external codes, and develops a product classification and coding system based on internal and external codes with reference to various classification coding systems at home and abroad. Internal and external codes are used separately in different department of the enterprise and their function is different, so it can solve the past problem of long codes and make the value of every code fully utilized. It is shown from the application that internal and external codes can meet the requirements of PDM for the classification and coding of turbine parts and contribute to its successful implementation in the enterprises.
Molecular dynamics simulation of pore - containing single crystal magnesium stretching along different crystalline orientations
Authors: Tang Jinqi , Yao Junping 
Published: November 2020

Abstract
The uniaxial stretching process of single crystal magnesium containing holes was simulated by molecular dynamics method, and the influence of the stretching crystal orientation on the growth and deformation of the holes was studied. Tensile simulations of different crystal orientations show that the microscopic mechanism of void growth and deformation in single crystal magnesium was different. For the orientation of the [1210] crystal, there will be small holes in the crystal at first, and with the process of loading, the polymerization of large and small holes will make the holes grow and then lead to the failure of the material. For the [0001] crystal orientation, the deformation mechanism was different from the former. In the early stage, it was caused by dislocation movement and stacking fault deformation, while in the later stage, it was mainly caused by twin nucleation and growth.
Solid-liquid Diffusion Interconnection Method Based on Cu-In Secondary Micro Nano Layer
Authors: Xiao Jin , Zhai Qian , Zhang Bin , Li Wuchu 
Published: November 2020

Abstract
A solid-liquid diffusion interconnection method based on Cu-In secondary micro nano layer is proposed. The substrate surfaces of two copper indium secondary micro nano layers with special morphology are contacted with each other, and the contact area is heated to carry out solid-liquid interconnection. The special morphology of copper indium micro nano layer includes copper needle layer and indium micro layer coated on it. During interconnection, liquid indium infiltrates copper needle layer and forms intermetallic compound with good plasticity. The microstructure, intermetallic compounds and shear strength of the interface were analyzed by scanning electron microscope (SEM), transmission electron microscope (TEM) and welding strength tester. The results show that this solid-liquid interconnection method can obtain good interconnection quality and it is of great significance to green packaging.
Extraction and surface activity of tea saponin from Pu’er tea seeds
Authors: Yang Zhi , Li Wenyi 
Published: November 2020

Abstract
Tea saponin was extracted from Pu’er Tea seeds using the ultrasound-ethanol method, the factors influencing the extraction rate were investigated, the extract was characterized and identified, and then the surface activity of the obtained tea saponin was explored from the aspects of surface tension, foamability and foam stability and detergency. The results show that the optimal extraction conditions include extraction time: 80 min, temperature: 70°C, liquid-solid ratio: 8:1, critical micelle concentration (CMC): 0.05%, and the surface tension is 30.01 mN/m under CMC concentration; the tea saponin has excellent foamability, high foam stability and strong detergency under CMC concentration.
Simulation Study of Area Effect at Shock Initiation of Shield Explosive
Authors: Jiang Lei , Li Ruibo , Qin Zhen , Xue Yan 
Published: November 2020

Abstract
To get the rule of area effect changing with diameter, velocity and height of projectile and thickness and material of target, the process of projectile perpendicular impacting target was simulated by AUTODYN and the pressure and velocity of observing points that set at the opposite side of hitting were analysed. And then simulation value and calculation value of experience formula in existence were compared. The result shows that experience formula is feasible, which provides a new method for the study of shield explosive shock initiation.
Structure design of camellia oleifera fruit sheller by EBD method
Authors: Meng Jie , Li Ang , Liang Xi 
Published: November 2020

Abstract
In this paper, through the analysis of the characteristics of camellia oleifera fruit (COF), a sheller with low damage rate of tea seeds, easy to manufacture and integrating shelling and screening functions is designed based on environment based design (EBD) method. The main structure of the COF sheller is designed and calculated. This design can provide a reference for the research of related machinery in camellia oleifera industry.
Evaluation of a robust Gel System for Water Shutoff in Large Aperture Fractures
Authors: Wu Qianhui , Ge Jijiang 
Published: November 2020

Abstract
Polymer gels for water shutoff usually base on high concentration and high molecular weight of hydrolyzed polyacrylamide (HPAM). It would lead to a high injection pressure during blocking the large aperture fractures in tight reservoirs. The in-situ polymerization of monomer gel (IPMG) has been investigated in this study. The properties of high strength and long-term thermal stability could greatly extend gel conformance control duration. The gelation time of IPMG can up to 24 hours at the temperature of 65°C. In addition, the gel strength with formulations based on Na montmorillonite (Na-MMT) was much better than that without it. The flooding experiments have shown that the robust gel has a high rupture pressure when blocking the fractures. Another benefit of the gel is a long-lasting decrease permeability of the fracture even after experiencing long time flooding.
Numerical simulation of internal flow and adsorption process in an activated carbon canister for ORVR system
Authors: Zhong Xianglin , Liu Daming , Li Yaqi , Zhen Xudong , Lu Shaoyun 
Published: November 2020

Abstract
In the vehicle fuel evaporation control system, the activated carbon canister is the core component and plays a vital role in the performance of the entire system. In this paper, a numerical simulation of the internal flow and adsorption process of an activated carbon canister used in an ORVR system was conducted to analyze the influence of the structure of the canister on the flow distribution and adsorption process. The research results showed that in the adsorption process, the flow through the activated carbon layer belonged to laminar flow, which was conducive to the full absorption of butane by activated carbon. In the desorption process, the flow velocity reached 0.05-0.09m/s. The higher flow velocity was beneficial to the desorption of the activated carbon. In the initial adsorption stage, due to the high flow velocity through the inlet, the butane concentration distribution was non-uniform, and the activated carbon under the inlet saturated faster than other positions. The activated carbon released heat during the adsorption process. The temperature at each monitor point showed a trend of fast increasing first and then slowly decreasing. The adsorption capacity of each monitor point increased significantly in the early stage of the adsorption process, while in the later stage tended to be stable. The adsorption capacity of butane was directly affected by the temperature of the activated carbon layer. The higher temperature was not conducive to the adsorption process.
Laboratory study on high-efficiency viscosity reducer in high temperature and salinity of heavy oil reservoir
Authors: Du Huili , Chen Fuhan , Guo Li , Zhao Ziyin , Chen Xi , Tang Yajuan , Lei Xiaoyang , Su Na , Zhang Tiantian 
Published: November 2020

Abstract
The Z70 reservoir of Huabei Oilfield is the typical heavy oil reservoir of high viscosity and high contents of gum and asphaltine, while there exists a serious problem that the effect of water injection is poor. In this paper, to increase oil displacement efficiency and improve reservoir development effects, the performance of seven different types of surfactants was studied, which combined with reservoir temperature and oil properties. Then, the emulsifying ability of the system was quantitatively characterized by water diversion rate combined with Turbiscan Lab. At the same time, the performance such as interfacial activity and static adsorption loss was studied under reservoir condition to obtain the viscosity reducing product with high-efficiency emulsification. considering the performance such as interfacial activity and static adsorption loss, the viscosity reducing product with high-efficiency emulsification was preferred for high-temperature and high-salt heavy oil reservoirs. Thus, the surfactant experiment was carried out to test the performance and applicability. one kind of surfactant, nonionic-amphoteric-anionic, was selected, which showed good dispersity and could form super-low interfacial tension with the crude oil of fault block Z70 in Huabei Oilfield. The interfacial tension reached 5×10−4mN/m when the concentration of the surfactants was 0.5%. And the No.1 combined system showed preferable emulsion performance with crude oil which stood for 30 minutes with no water precipitating out. It also provided, after 180 minutes, the emulsion system was completely demulsified, which could be re-emulsified after slight shaking. Good viscosity reducing property was showed with the oil-water ratio range of 1:1∼1:9, which viscosity reduction rate was more than 99.5%. furthermore, low static adsorption loss was showed when the adsorption capacity was less than 4.4mg/g. The experiments indicated that No.1 non-ionic-amphoteric-anionic composite surfactant could be determined to be the efficient viscosity reducer for fault block Z70 in Huabei Oilfield.
Study on the variation law of interlayer interference in injection-well
Authors: liu Guo-hua 
Published: November 2020

Abstract
In order to solve the problem of flow rate and pressure change in the stratified injection well test process, that is, when the flow rate of one layer is adjusted, the flow rate of other layers also changes. The adjusted layer changes when other layers are adjusted, and the wellhead pressure also changes. Therefore, through the research of this problem, find out the interference coefficient and pressure change, realize efficient allocation, and provide ideas and basis for new flow allocation mode.
Study on ultraviolet absorption characteristics of SF6 decomposition components
Authors: Shiling Zhang , Qiang Yao 
Published: November 2020

Abstract
Establish the UV spectrum database of the SF6 characteristic decomposition components: Based on the previous research and simulation analysis, obtain the UV spectrum of the SF6 characteristic decomposition components, and establish the corresponding database. Through the analysis of a large number of actual test data, the ultraviolet spectrum database of SO2, CS2 and H2S is obtained and established to realize the quantitative analysis of SO2, CS2 and H2S. The detection accuracy of H2S and the SO2 reaches 10−6 level, and that of the CS2 reaches 10−9 level, realizing the low concentration quantitative detection of SF6 characteristic components. The detection of SO2, CS2 and H2S in gas insulated equipment can effectively predict and diagnose the occurrence of partial discharge fault, partial overheating fault and solid insulation fault in gas insulated equipment. As the symbol gas, the generation of H2S directly indicates the occurrence of more serious partial overheating or partial discharge fault, while SO2 is the characteristic component gas. The occurrence of CS2 indicates that there may be a local fault involving solid insulating medium in the equipment. The detection of three gases can provide important conditions for on-line monitoring of gas insulated equipment.
Study on the Method of Measuring the Molecular Weight of Polycarboxylate Water Reducer by Gel Chromatography
Authors: Shao Youzhe , Li Geli , Wu Chuandeng , Fang Yunhui , Guo Yuanqiang , Lin Tianxing 
Published: November 2020

Abstract
The effects of the type of mobile phase and its flow rate, column temperature, and detector temperature on the chromatographic peak separation and molecular weight test results of polycarboxylate water-reducer were studied. A method for measuring the molecular weight of polycarboxylic acid water-reducing agent by gel chromatography was established, and the accuracy of the method was verified by using two dextran standard substances of standard sample 2, standard sample 3. The results show that a 0.1 mol/L sodium nitrate solution containing 0.05% sodium azide should be selected as the mobile phase, the flow rate is 0.8-0.9 mL/min, and the column temperature and the detector temperature are 35-40 °C. It has been verified that the relative errors of the molecular weight test results of standard sample 2 and standard sample 3 are all less than 5%, and the MP, Mn, and Mw values measured by this measurement method are close to the true values.
Study on adsorption of Pb(II) and Cr(VI) by MMT/St-g-P(DMC-AA)
Authors: Zhang Caining , Wang Xuman 
Published: November 2020

Abstract
By applying methacryloyloxyethyl trimethyl ammonium chloride (DMC) and acrylic acid (AA) as the monomers, starch (St) as the main chain polymer, the composite MMT/St-g-P(DMC-AA) was prepared. Applied the composite as the adsorbent, Pb(NO3)2 (Pb(II)) and K2CrO7 (Cr(VI) ) as the adsorbates, the effects of adsorption time and the initial haevy metal ions concentrations on the adsorption capacities were studied. The adsorption data were evaluated by adsorption kinetics models. The experimental results showed that the adsorption capacities for heavy metal ions increased with the increasing of adsorption time, and then saturated after 60 min. And adsorption capacities for Pb(II) and Cr(VI) were 140.79 mg/g and 32.25 mg/g, respectively. The adsorption capacities also increased with the increase of initial concentrations. The adsorption data of Pb(II) and Cr(VI) by MMT/St-g-P(DMC-AA) were well described by the pseudo-second-order kinetic model.
The effect of polymer type on the performance of gels
Authors: Zhang Tianci , Zhao Qingchen , Guo Hongbin , Ge Jijiang 
Published: November 2020

Abstract
Owing to the formation heterogeneity, the difference of mobility between sweeping phsse and formation fluids, gravity segregation, the sweeping phase usually flows along the high permeability zone, which leads to the poor oil recovery. In general, gelling systems are used into the reservoir conformance improvement. The properties of gels are different for the different composition of gelling systems. In this paper, three polymers with different AMPS content were used to investigate the effect of polymer type on the performance of polymer gels. In addition, methenamine(MA) and hydroquinone(HQ) were employed as crosslinkers, thiourea(TH) was used as oxygen scavenger to improve the stability of polymers and gels. And the gelation time, strength and syneresis rate of gels were characterized respectively. The results showed that the stability of polymer and gel was enhanced with the increase of AMPS content, and the gelation time was increased with the increment of AMPS content. And an ultrastable thermal-resistance and salt-tolerance gel was developed with the AM/AMPS copolymer (AMPS content equals 70%), the syneresis rate was less 10% after heat treatment under the harsh conditions (temperature=130°C, salinity=223802.8mg/L) for 150 days.
Section model test analysis of gate
Authors: Chang-hong Wang , Guang-lu Wang 
Published: November 2020

Abstract
It is a common hydraulic problem to study the characteristics of the discharge flow and the energy dissipation and scour prevention of the downstream of the hub. At present, many hydro junction projects under construction are located in canyon reach, and the layout of hydro junction is limited by terrain conditions. Therefore, it is necessary to study and analyze the general layout scheme and discharge capacity through experiments. The key technologies and objectives of this kind of section model are put forward, which can be used for reference and guidance in the development of similar cross-section model tests.
In situ growth of Ni(OH)2 nanoflakes on Ni foam as binder-free electrode for electrochemical pseudocapacitor
Authors: Liu Yu , Liu Ning , Hu Junping , Xu Chengyong , Wang Sujie , Du Guoping 
Published: November 2020

Abstract
In this work, a facile one-step hydrothermal method has been adopted to prepare Ni(OH)2 directly deposited on Ni foam in ultrapure water. The phase structure and morphology composition of the in-situ grown Ni(OH)2/Ni foam (NF) were analyzed using an X-ray diffractometer (XRD) and scanning electron microscope with energy disperse spectroscopy (SEM-EDS). The results indicate that Ni(OH)2 nanoflakes uniformly in-situ grown on Ni foam construct a hierarchical structure, which in favour of full infiltration with electrolyte, and also beneficial to the reliable stability of the Ni(OH)2/NF electrode. While being employed as an integrated binder-free electrode for electrochemical pseudocapacitor, the Ni(OH)2/NF shows a high specific capacitance of 1470.8 F/g at 2.5 A/g in 2 M KOH. This work demonstrates a highly-simple and cost-effect approach for designing binder-free electrodes for high-performance electrochemical pseudocapacitor.
The theoretical study on formation energy of zinc-blende and wurtzite ZnO1-x
S
x
alloys
Authors: Luo Minghai 
Published: November 2020

Abstract
A theoretical study on formation energy of zinc-blende (ZB) and wurtzite (WZ) ZnO1-x
S
x
has been carried out with the first-principles methods and the Alloy Theoretic Automated Toolkit (ATAT). The cluster expansion approach was used to describe the disordered alloys, for x = 1/6, 1/3, 1/2, 2/3, and 5/6. With the analysis of the formation energy, the WZ structure is thermodynamically more stable than ZB structure at all temperatures and alloy compositions, which is in agreement with experiments.