bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance Evaluation of Penstock By-Pass System Modification on HEPP (Hydro Electric Power Plant) with CFD Analysis to Optimize Power Consumption
Authors: Harpendi  , Sugianto  , Wijanarko Dwi , Caesarendra Wahyu
Published: June 2021

This paper proposes a feasibility test for the performance modification of the penstock by-pass system using CFD (Computational-Fluid-Dynamic) simulations to optimize the energy use of the water-cooling system. The main advantage of this modification is the power savings of 45%-50%. This modification of the by-pass system is carried out with the aim that the final flowrate and pressure of modification can replace the Main-Water-Supply-Pump (MWSP) operation function in the unit’s main cooling system. CFD simulation is carried out on the impact of a pressure drop of 40-4 bar with a flow of 0.3 m3/s on the by-pass pipe flow of the existing penstock system and the condition of the pipe modification to be carried out. The numerical simulation results show that the MWSP network structure can accept load flow pressures varying 40-4 bar. This simulation refers to the conditions in HEPP Saguling Indonesia and can be applied to others.
Design of BOOST converter based on CN3306 chip
Authors: Linbo Gan , Anfei Xu , ziqiang Xi , xiaogang Du
Published: June 2021

CN3306 is a current mode fixed frequency PWM boost type multiple battery charging management integrated circuit. This article introduces the basic principles and characteristics of CN3306, and designs a boost circuit based on the characteristics of CN3306 chip with stable voltage, small ripple range and low power consumption. Explained in detail how to select peripheral circuit parameters and the practical application of CN3306 in BOOST circuit, and use the PSIM simulation software to build a photovoltaic power generation system model for simulation verification, the result reached the expected value.
Comprehensive Evaluation Indexes Framework and Evaluation Method for Substation Site Selection
Authors: Um Saony , Zhang Yiyi , Li Bin , Zhu Yun
Published: June 2021

The optimal planning of substation location is very significant for the construction of a reliable and reasonable power system, for this purpose, the comprehensive evaluation index system and the evaluation method are researched. Firstly, for the optimal layout of substation location an evaluation index system, which covers four aspects, i.e., security, economy, environment and operation, is established. Then, with a comprehensive consideration of the subjective weights and the objective weights, optimal combination weighting based on moment estimation theory is used to determine the optimal combination weight of each index. On this basis, an improved grey relational analysis method is proposed through a combination of grey relational analysis and cosine sorting method, to determine the optimal site selection more accurately and reasonably. Finally, using the proposed evaluation index system and evaluation method, the location of the newly added substation location in Phnom Penh power system is researched and the conclusion that Plan I should be taken as the location for the newly added substation is attained. The effectiveness and feasibility of the proposed evaluation index system and evaluation method are verified by the attained conclusion. Moreover, it shows that it has good application value for the optimization of substation location planning.
Self Powered Circuit with Composite Energy Storage for Monitoring Terminal in Distribution Network
Authors: Wang Yang , Xi Wenbing , Chen Jian , Chen Ming , Hu Sheng
Published: June 2021

In this paper, a self powered circuit with composite energy storage for monitoring terminal in distribution network is proposed, which is consist of a rectifier circuit, DC/DC converter and composite energy storage. Firstly, the self powered circuit obtained energy by CT (Current Transformer) from the lines in distribution network. Then, the expected DC voltage was obtained by rectifier circuit and regulated by DC/DC converter. To enhance the power supply reliability, composite energy storage is applied, which is regulated by coordinated control. To verify the effectiveness, a simulation model was built in MATLAB, and the result are satisfactory.
Research on cooperative optimal scheduling of industrial park microgrid considering controllable load
Authors: Liang Jishen , Kang Li , Zhang Hongye
Published: June 2021

This article uses a multi-objective Q-learning algorithm to study the collaborative optimization dispatching of the combined cooling, heating and power(CCHP) microgrid in the industrial park considering controllable load. First of all, the article establishes a microgrid collaborative optimization scheduling model with controllable load based on the optimization goals of minimizing microgrid operation and maintenance costs and minimizing polluting gas emissions. Secondly, the article introduces the solution method and steps of multi-objective Q-learning algorithm based on Pareto ranking method in multi-objective collaborative optimization of microgrid. Finally, the article takes an industrial park as an example and uses a multi-objective Q learning algorithm to solve the model. The calculation example analysis shows the effectiveness of the collaborative optimization model and solution method established in the article. The participation of controllable load in collaborative optimization can reduce the operation and maintenance cost of the microgrid, at the same time, it can reduce the load fluctuation of the microgrid and improve the power quality of the microgrid.
Optimal Scheduling Model of Virtual Power Plant and Thermal Power Units Participating in Peak Regulation Ancillary Service in Northeast China
Authors: Zhang Hongpeng , Li Dan , Tian Zengyao , Guo Liang , Chen Jie
Published: June 2021

In recent years, the rapid development of wind power generation and the low load growth rate have brought challenges to the peak regulation of power grid in Northeast China. In order to solve the peak regulation problem, virtual power plant (VPP) is proposed to participate in the peak regulation auxiliary service market in Northeast china, especially for deep peak regulation. Firstly, two modes of peak regulation in Northeast China are introduced in this paper, which are thermal power unit and VPP. With the definition of the peak regulation capacity for VPP, the Optimal Scheduling Model of VPP participating in peak regulation ancillary service is established. The simulations are carried out in MATLAB. The results show that the economy of peak regulation is significantly improved in peak regulation auxiliary service based on VPP.
Research on Optimal Design of Double Stator Low-speed High-torque Synchronous Motor Based on Surrogate Model
Authors: Chen Yang , Zhang Fengge , Yu Siyang , Jin Shi
Published: June 2021

Optimizing double stator low-speed high-torque synchronous motor (DSLHSM) with many parameters is difficult and time-consuming, so an optimization design method suitable for multi-parameter problems was proposed. Through the method, the design optimization of DSLHSM can be more effective, and the optimization time is greatly shortened. Firstly, the optimization variables were selected after the sensitivity of the key parameters of average torque and torque ripple was analysed by using design of experiments (DOE) and analysis of variance (ANOVA). Secondly high-precision dynamic surrogate models of average torque and torque ripple were established based on response surface model (RSM), and then the objective function was established according to the surrogate model and the genetic algorithm (GA) as well as the sequential subspace optimization method (SSOM) was used to solve the objective function step by step. Finally, the optimal solution was substituted into the finite element simulation model. The target performances of the motor before and after optimization were compared and analysed. The results proved the effectiveness and correctness of the optimization design method.
Research on the Modelling of a Single-winding Bearingless Permanent Magnet Brushless DC Motor
Authors: Tu Xiaowan , Bu Wenshao , Zeng Qian
Published: June 2021

This paper studies the radial suspension force mathematical model of a single-winding bearingless permanent magnet brushless DC motor, which provides a theoretical basis for the precise control of a single-winding motor. First, the physical structure of the single-winding BL-BLDC motor and the principle of radial suspension force generation are introduced. Then, the equivalent magnetic circuit method is used to establish the electromagnetic relationship inside the motor and the virtual displacement method is used to derive and calculate the mathematical model of the radial suspension force. The radial suspension force of the motor is composed of the force generated by the suspension force winding and the unbalanced magnetic pull force generated by the motor rotor deviating from the center position. Finally, the finite element analysis software is used to model and simulate the single-winding motor to analyze the change of the suspension force amplitude under different currents and the influence of different eccentric displacements on the unbalanced magnetic tension of the motor. The results show that the error between the simulation results obtained by the FEA and the theoretical calculation results of the mathematical model is small, which verifies the correctness of the radial suspension force mathematical model of the single-winding BL-BLDC motor.
Experimental assessment of swelling potential in montmorillonite soils
Authors: Pérez J C , Ruge J C , Rojas J P , Orjuela J A , Cáceres J R
Published: June 2021

The study of the physicochemical activity of clays is essential to understand the mechanical-hydraulic behavior. The experimental analysis of the expansivity of soils is linked to the content of clay minerals present in the tactoid tissue, which affect is directly in proportion to the volumetric change that soil may undergo. This work aims to carry out an analysis to understand the expansive behavior of the proposed clay materials, using different techniques, both conventional and modern. For this purpose, the bentonite clay used with a majority montmorillonite component was analyzed through petrographic tests and images analysis. The samples with a base material and different contents of montmorillonite were prepared. Montmorillonite is a clay mineral with a very high swelling potential because even when it was used in low proportions on a sandy base material, the influence of the material is strong and the expansivity remained high.
Applications of the method of lines for modeling the physical phenomenon of heat conduction
Authors: Nolasco Serna C , Afanador Garcia N , Guerrero Gómez G
Published: June 2021

It is claimed that most of the fundamental principles that govern the physical phenomena of interest in engineering applications can be described by differential equations. Therefore, the ability to analyze, solve and understand differential equations is essential for decision-making in the applied areas. In this sense, studying efficient methods to solve differential equations is a fundamental contribution in advancing the understanding of relevant physical models in engineering applications. The purpose of this research allowed to study the differential equation associated with Fourier’s heat transfer law and calculate its solution by two different methods than the traditional method. From this context, the study is related to the phenomenon of heat conduction in a metal bar under ideal conditions to later carry out its application in a particular case. First, the solution of the differential equation that models the physical phenomenon derived from the use of Fourier’s physical heat law is calculated with the use of statistical tools; then, a solution scheme is implemented using method of lines. Given the nature of the investigation, the solutions by both methods are compared about what is expected in the physical interpretation of Fourier’s law.
Design and simulation of conformal cooling for a die-casting mold insert
Authors: Shu Lei , Zhang Zhengwen , Ren Zhihao , Zhang Tao
Published: June 2021

Traditional cooling channels make the mold have defects of poor cooling and low efficiency. Selective laser melting(SLM) can be used to produce the mold with conformal cooling channels. In this paper, the design and simulation of conformal cooling channles for a die-casting mold insert are carrried out. Compared with traditional cooling channels, the distribution of conformal cooling channels is closer to the die surface to be cooled and the cooling is more effective. After 5 s of simulation analysis, the effective cooling efficiency is 54.83%, and the temperature distribution on the die surface is more uniform. The die-casting mold insert with conformal cooling channels is fabricated by XDM 250.
Design of an Airtightness Detection Device for Infusion Connector with Automatic Loading/Unloading Function
Authors: Peng Yi Hang , Yan Chen Ting , Peng Liu Xue
Published: June 2021

Based on the production and detection procedures of a medical infusion connector, the original detection device was innovatively designed, and an airtightness detection device with automatic loading/unloading function was developed, in an effort to improve the loading/unloading efficiency and airtightness detection efficiency of the infusion connector and complete the automatic detection task at rate of 20-30 ones per min. The basic device composition of this infusion connector was introduced, and the basic structural features and working principles of each device were analyzed. The importance was attached to the calculation methods for key dimensions that influenced the detection quality and material loading, and in this way, while the batch material loading was realized, the difficulties in the airtightness detection and automatic sorting of finished products were solved. The original manual material loading was converted into automatic material loading and the frequency of simultaneous airtightness detection was increased, which reduced the amount of labor used, improved the overall production efficiency and lowered the production cost.
Design of multifunctional combined walking aid
Authors: Gu Jie , Wang Jingyuan , Sun Ming , Wu Qing
Published: June 2021

In view of the lack of a portable walking aid with multiple functions in the current market, a multifunctional combined walking aid is designed. The device is based on raspberry pie, and controls the whole device through human-computer interaction of touch screen; the dynamic and non dynamic switching is realized through disassembly structure, which can have the advantages of walking aid and crutch structure; a stacked connection structure is designed, which can realize the functions of folding and drug storage in a cylindrical structure at the same time; a vertical driving wheel is adopted, which can realize the function of folding and drug storage. The independent driving of two wheels enables the user to enter the control position from the rear side of the walking aid. The experimental results of the prototype show that the device has the advantages of strong functionality, convenient operation and broad application prospects.
Analysis of Dynamic Characteristics of 6-PSS Parallel Mechanism Considering Spherical Hinge Clearance
Authors: Kun Zhao , Daiping Song
Published: June 2021

This paper is based on a new type of 6-PSS parallel mechanism. Firstly, considering the clearance between the kinematic pair connecting the upper platform and the link, establish a kinematic model considering the spherical hinge clearance. Then, based on the Lankarani-Nikravesh(L-N) contact model and the modified Coulomb friction model calculate the contact force when the spherical elements contact, which is equivalent to the center of the corresponding member as the generalized external force. Apply for Newton Euler method with Lagrange Multiplier to establish the dynamics model of the parallel mechanism with clearance. Finally, the R-K method is used to solve the dynamic equation and analyze the influence of different spherical hinge gap sizes on the dynamic characteristics of the mechanism.
Analysis of electromagnetic characteristics of a new electromagnetic ejection device
Authors: Ren Shi-da , Feng Gang , LI Teng-da , Yang Hui
Published: June 2021

Electromagnetic ejection technology is a new launching technology which uses electromagnetic force to accelerate the projectile to ultra-high sound speed. This technology can break through the speed limit of traditional gunpowder launching, and realize the accurate control of exit speed by controlling the excitation pulse current.

Four track electromagnetic launcher is a special enhanced electromagnetic launcher, which has many advantages that dual track electromagnetic launcher does not have. Its development greatly promotes the application of electromagnetic launch technology in aerospace field. In this paper, according to the practical needs of electromagnetic space launch technology, a simple four orbit electromagnetic launch device is designed and established; the finite element analysis of the model is carried out, and the electromagnetic and current characteristics are simulated, and the skin effect and proximity effect of current are obviously observed; the theoretical analysis and formula derivation of inductance gradient are carried out, and finally two kinds of inductance gradient are proposed based on the finite element theory simulation A simple example is given.
Born-Oppenheimer Molecular Dynamics of OH Radical in the SiC Grains in the Reaction-Sintered Silicon Carbide
Authors: Yang Xiaocui , Zhu Nannan , Zhao Rongxing
Published: June 2021

Born-oppenheimer molecular dynamics is an effective method to analyze machining mechanism of some advanced manufacturing techniques, which was introduced to investigate the absorption of OH radical on different β-SiC surfaces in the reaction-sintered silicon carbide. During the plasma oxidation-assisted polishing of reaction-sintered silicon carbide, absorption of the OH radical in the SiC grains was one of the most important process, because hardness of the SiC grains was obviously higher than that of the Si grains. the born-oppenheimer molecular dynamics model to investigate the absorption process of the OH radical was constructed firstly, which could form the foundation for the further simulation and analysis. Secondly, absorption of the OH radicals in the Si-face, those in the C-face, and those in the asymmetric face were investigated successively, which included the absorption process and the oxide product. Finally, comparisons of the absorption of the OH radical in the different faces were conducted, which aimed to further understand the plasma oxidation-assisted polishing of reaction-sintered silicon carbide. Simulation result of born-oppenheimer molecular dynamics was propitious to promote the machining level of reaction-sintered silicon carbide and promote its practical application.
Covariance transformation method for polar integrated navigation
Authors: Zhang Yongjian , Wang Lin , Wei Guo , Yu Xudong , Gao Chunfeng
Published: June 2021

The aircraft flying the trans-arctic routes faces the problem that the changes of navigation frames will affect the navigation accuracy. To solve this problem, taking Inertial Navigation System/Global Navigation Satellite System (INS/GNSS) integrated navigation system as an example, an integrated navigation method based on covariance transformation is proposed. This method aims at finding the transformation relationship of the system error state and the covariance between different navigation frames. The experiment and semi-physical simulation results show that the covariance transformation algorithm can effectively solve the filtering instability caused by the changes of the navigation frame. Compared with the non-covariance transformation, the system state error is reduced by an order of magnitude.
Cross-section Effect on Mechanical Properties of Al A356 Alloy Tensile Specimens
Authors: Hu Xinping , Li Ruixin , Wang Qing
Published: June 2021

Tensile testing is an effective method to evaluate the mechanical property of aluminum alloys. In the present work, two types of standard tensile specimens with round (RD) and rectangular (RT) cross-sections were cast in the same permanent die and their solidification characteristics, microstructures, and mechanical performances were studied. The equilibrium solidification and Scheil solidification models of the studied A350 alloy were calculated by Pandat software. The experimental solidification and cooling temperature analysis revealed that the solidification platform and supercooling of the RD sample were 3 seconds wider and 1.2 °C bigger than those of the RT one. The microstructural analysis expressed that the mean grain diameter and secondary dendrite space of RD were 1.52 and 0.75 um smaller than those of RT; hence, the strength and elongation of RD were better than those of RT. Brinell hardness tests and differential scanning calorimetry were also carried out. According to the obtained data, the round specimen was selected for tensile test because of its superior performance.
Vibration Response Testing and Evaluation of A Hydropower Station’s Gate
Authors: Peng Ding , Gaofeng Yue , Pengxiang YU , Chuansheng Yang , Shudong Gong , Lei Guan
Published: June 2021

We use standard vibration source to verify the method that vibration displacement was obtained by filter and integral in frequency domain. The feasibility and reliability of this method was confirmed. A gate’s vibration response such as acceleration, dynamic stress and displacement was tested. The vibration acceleration is less than 3 m/s2, the vibration displacement is less than 0.25 mm, and the dynamic stress is less than 153.2 MPa. In the initial stage of the gate lifting, the maximum vibration displacement over the standard requirements. Vibration evaluation of the gate was given by the acceleration, displacement and dynamic stress.
Research on the reform of automobile testing curriculum under the background of intelligent
Authors: Lijunling  , Xingzhihui
Published: June 2021

Under the background of intelligent manufacturing, the teaching and implementation of automobile testing course should keep pace with The Times. Detection course of automobiles is a particularly strong practical transportation professional course, this article mainly analyzes the automobile detection course of original defects in the teaching method, raise the significance of the integration of teaching and teaching methods, teaching means reform practice, through the reform to improve the students’ interest in learning, practice ability, flexible use of theoretical knowledge ability to solve practical problems, It is conducive to the cultivation of applied talents. It is conducive to the cultivation of intelligent manufacturing talents.
Intelligent control system for flocculation of water supply
Authors: Fan Kaiguo , Xu Yang
Published: June 2021

Flocculation which affects the quality of water supply is the main step of water treatment. The most commonly used control method for flocculation is the streaming current detection-based control method using a single-loop feedback. However, the traditional control system cannot adapt to the change of raw water’s quality, the set value of streaming current can only be adjusted manually. In order to solve this problem, an intelligent control system for flocculation of water supply is designed based on the neural network and fuzzy control to adjust the set value of streaming current and tune the control parameters automatically in this study. The experimental results show that the proposed intelligent control system can control the flocculant dosage accurately. It is of great significance to improve the quality of water supply and reduce the cost of water treatment.
The Enlightenment on Emergency Management of Elevator
Authors: An Ziliang , Wang Ning , Li Zhihui , Bai Dingsong , Gan Ningli , Huang Yuxin
Published: June 2021

Elevator is not only a means of transportation for people, but also a symbol of national science and technology. With the hot topic in the field of elevator safety, the public awareness of elevator emergency management has increased remarkably. In response to the current fragmentation dilemma of elevators in China, elevator information management system is integrated by Multi department and the operating information is pushed by APP software, so the elevator accidents would be processed effectively.
A data-driven fusion model for energy consumption prediction of hot extrusion forming
Authors: Yang Dan , Li HongCheng , Luo Rong , Liu Yitong , Cao Huajun
Published: June 2021

Hot extrusion forming is widely used to process lightweight parts in automobile, aircraft manufacturing, and subway industry. However, hot extrusion forming is an energy-intensive process with high environmental emissions. Because hot extrusion forming is a complex thermal-mechanical coupling process, it is difficult to develop its energy consumption prediction model based on the process mechanism. With the increasing application of data intelligent acquisition, this paper proposed a fusion data model integrating bagging enhanced ELM (Extreme Learning Machine) and GPR (Gaussian Process Regression) using their entropy weight. The energy-related data collected by energy management system are purified using the local outlier factor (LOF) algorithm and Rrelief F method. The bootstrap sampling method is used to obtain the training set and test set from the processed data. Then, the ELM and GPR are improved by the bagging algorithm for constructing the B-ELM learning model and the B-GPR learning model. Furthermore, the entropy weight method is used to further integrate the B-ELM and the B-GPR. Finally, an experiment validates the accuracy and reliability of the proposed model.
A steel classification algorithm based on surface defects
Authors: Qinge Wu , Ziming An , Lintao Zhou , Hu Chen , Yingbo Lu , Zhiyuan Ma
Published: June 2021

In the research of image recognition and classification, image retrieval, image data mining, and so on, feature extraction is the basic work, among which the texture feature of an image is of great significance to describe the content of the image. In this paper, an extraction method of steel texture features based on a gray co-occurrence matrix is presented, and the influence of various structural parameters on the structure is analyzed. The feature extraction of specific texture images based on a gray level co-occurrence matrix is realized, and the data classification is carried out by using a probabilistic neural network.
Based on Pearson correlation coefficient and Monte Carlo simulation method, the calculation formula of frictional resistance is optimized for soft shaft bending and pulling of steel wire
Authors: Wang Tengfei , Li Jian , Liu Yisheng
Published: June 2021

The main content of this study is based on Pearson correlation coefficient and Monte Carlo simulation method to optimize the frictional resistance calculation formula for pushing and pulling flexible wire shafts in different bending states. According to the calculation formula and experimental data of the frictional resistance of the soft shaft bending of the wire, in order to improve the calculation accuracy, the Pearson correlation coefficient test is carried out by f f=μDβPyn
/1 + y2
SPSS software, and the coefficient β and the corresponding friction f between the shaft core and the sheath are very relevant at all angles, so the size of the β can be adjusted to make the calculation of friction f more accurate. The parameters and parameters of the formula β modified by the Monte Carlo simulation method, and the frictional resistance formula of the flexible wire rope shaft at different angles is optimized. The optimized formula is calculated with an overall error of 2.3260%, which is 1.5637% lower than the original total error of 3.8898%, and is suitable for soft shaft friction with different diameters at a certain calculation angle.
Research on Geometric Error Prediction of High Speed Dry Cutting Gear Hobbing Based on MPGA and BPNN
Authors: Hou Yuehui , Yan Chunping , Chen Jianlin , Chen Liang
Published: June 2021

The geometric error of high-speed dry cutting gear hobbing is affected by many factors, such as process parameters, gear hobbing machine tools and hobs, and it is difficult to predict. This paper uses the vibration of the hob spindle to predict the geometric error, and builds a geometric error prediction model for high-speed dry cutting gear hobbing based on multiple population genetic algorithms and BP neural network. This model comprehensively considers the influence of the hob spindle speed, feed rate and hob spindle vibration on the geometric errors of high-speed dry cutting gear hobbing, which can provide a useful reference for the improvement of gear machining geometric accuracy. Through the experiment, it is concluded that adding the hob spindle vibration during the machining process as the model input can obtain more accurate prediction results of the geometric error of the hobbing machining. Compared with the traditional BP neural network prediction model, this model has better prediction ability.
Research on Multiple Signal Synthesis Methods in Space Electromagnetic Environment Simulation
Authors: Yuan Wang , Wei Tan , Lidong Cui , Ying Li
Published: June 2021

This paper proposes three spatial electromagnetic signal environment concepts from three levels: general electromagnetic signal environment, relative electromagnetic signal environment and electronic warfare signal environment. It can solve the difficult problem of comprehensive, accurate and targeted description of the electromagnetic environment in the space electromagnetic environment simulation of the spacecraft. This paper studies the synthesis method of various types of signals contained in the three electromagnetic signal environments in a certain area, and provides a reference for the accurate simulation of the dynamic and intuitive, hierarchical electromagnetic environment situation in a certain area of space.
Research on the Updating Method of Vehicle Frame Finite Element Model
Authors: Lu Zhen , Yang Zengjie , Yang Zhongliang
Published: June 2021

First, the strain gauges were pasted on the front and back tie rods of the vehicle for the sake of calibration. Under the designated working conditions, the strain data of the tie rods were collected via a data acquisition unit (DEWESoft). Meanwhile, the pressure of suspension cylinder was measured, the force distribution ratio of front axle and back axle was respectively calculated through the strain data and cylinder pressure data, and the calculation formula of the distribution ratio was obtained. The calculation results were verified through a traction test of the complete vehicle. In the end, the finite element model was updated according to the test data, followed by the analysis of the structural stiffness and strength. The method proposed in this paper will considerably contribute to the improvement of finite element analysis accuracy of the complete vehicle, and moreover, it can be promoted in the design of other similar structures, with a certain reference significance.
The influence of gravity load on the accuracy of mesh reflector antenna
Authors: Wang Lipeng , Zhang Xin , Hu Jianfeng , Yang Zhao , Xiao Yong
Published: June 2021

Space large deployable mesh antennas are the focus of research in the aerospace field. There is a high requirement for the reflector surface accuracy of the mesh antenna in orbit. Due to the low stiffness of the truss cable net system, the deformation of the flexible mesh surface under the ground gravity load cannot be ignored. Therefore, it is the key technology to ensure the accuracy of on orbit cable network reflector that accurately predict the difference of reflector under gravity load and microgravity load. This study establishes the mechanical model of the cable-truss system. The Newton Iterative Method is used to solve the nodal nonlinear equilibrium equation in the gravity load, and the deformation of the antenna mesh surface under the gravity load is obtained.
Development of a ceramic double thick GEM detector for transmission measurements at the VESUVIO instrument at ISIS
Authors: Cancelli S. , Muraro A. , Perelli Cippo E. , Romanelli G. , Abba A. , Chen Y. , Grosso G. , Gorini G. , Hu Z. , Lai C.-C. , Mc Cormack O. , Robinson L. , Svensson P.-O. , Tardocchi M. , Hall-Wilton R. , Xie Y. , Zhijia S. , Zhou J. , Zhou X. , Croci G.
Published: June 2021

Neutron spallation sources always require new instrument upgrades and innovations in order to improve the quality of their experiments. In this framework, the capability to accurately measure total neutron cross sections at the VESUVIO instrument at the ISIS Facility can be boosted by a tailored transmission detector. For this reason, the first double ceramic thick GEM detector has been realised.
Detectors based on GEM technology are broadly developed thanks to their characteristics, such as good spatial resolution (< 0.5 mm), good detection efficiency, high rate capability (MHz/mm2) and a possible coverage area of some meters at low costs. This article shows the realisation of a GEM detector made of a 10B4C cathode, two ceramic thick GEM foils and a padded anode, as well as the device characterisation on the VESUVIO beam line, where stability, γ-sensitivity, imaging capability and sample analysis have been studied.
The successful results confirm that the ceramic thick GEM detector performs well in thermal and epithermal neutron detection and it will allow the scientific user community of the instrument to perform better quality transmission measurements so as to determine more accurate total neutron cross section of condensed-matter systems.
Prototype of simultaneous bidirectional data-transmitter in 65 nm CMOS
Authors: Kishishita T. , Krüger H.
Published: June 2021

This article presents a design and implementation of an I/O
circuit block capable of simultaneous bidirectional
data-transmission in CMOS integrated circuits. Merging
data-transmitter and receiver into common bonding pad is feasible
not only to reduce the number of transmission lines from a
considerable number of chips, but also to realize more
area-efficient data handling in consequence of flexible inter-chip
communication. This feature is attractive from the viewpoint of
detector systems in high energy experiments, in which reducing
materials such as cables from silicon trackers in inner vertex
layers is of major importance to suppress multiple-scattering and to
achieve good overall detector performances. The circuit block
presented here is designed on the basis of a current subtraction
circuit and two distinct current-mode logic drivers. Its principle
is also applicable to widely-used low-voltage differential signal
drivers and easy for process migration. The prototype chip was
fabricated in a 65 nm CMOS technology. Working principle has been
demonstrated in preliminary laboratory testing.
Calculation of a food consumption nitrogen footprint for Germany
Authors: Klement Laura , Bach Martin , Geupel Markus , Breuer Lutz
Published: June 2021

Reactive nitrogen (Nr) that is released to the environment has several negative implications for the atmosphere, hydrosphere, biodiversity and human health. A nitrogen (N) footprint is a measure that can help to assess and communicate the impact of personal lifestyle and consumption choices regarding their influences on Nr losses. The N-Calculator tool was developed to estimate this footprint. However, underlying loss factors for the food sector in the N-Calculator rely on data from the US, for which the calculator was originally established. Since the conditions in agriculture and the food industry differ significantly between the US and other countries, and the fact that the food sector is considered the main source of Nr losses in the N-Calculator, a revision of the N-Calculator is required if applied to other countries. Here we present a revised N-Calculator for Germany that is based on German food production data. In this study, virtual nitrogen factors describe the losses of nitrogen in a supply chain. Losses were calculated for 20 plant-based products, 17 feed materials, 18 compound feeds and 14 animal-based products. The N footprint varies considerably between products. While plant-based products amount to a weighted average of 3.4 g N loss per kg product, animal-based products cause significantly higher losses with 40.5 g N loss per kg. Overall, the average N footprint for the German consumer is calculated to be at 9.94 kg per capita and year. To validate the results, the individual categories were scaled up to the national level and then compared with statistical data on N flows in Germany. In general, the results showed good agreement with key production figures and the overall N budget for Germany. Furthermore, some improvements are proposed to increase the informative value and user acceptance of an N-Calculator.
Research on Large Deformation Mechanism and Countermeasures of Shallow Buried Soft Rock Tunnel with Abundant Water
Authors: Yuan Qing , Chen Shihao , Xiao Jing , Xiong Qihuan , Zhang Ziping
Published: June 2021

In view of the obvious deformation characteristics of shallow buried soft surrounding rock tunnels affected by excavation disturbance, this article takes a Tunnel as the engineering background and combines the geological conditions of the tunnel to carry out on-site monitoring and analysis of surrounding rock deformation after tunnel excavation. The deformation after excavation has the characteristics of fast deformation speed, long duration and large deformation. In addition, the excavation position and step have an important influence on the settlement of the vault and the convergence of the surrounding rock. The settlement of the vault and the convergence of the surrounding rock caused by the excavation of the upper and middle steps account for 61.16% and 63.34% of the total deformation respectively. Through the analysis of large deformation and collapse phenomenon, it is known that the large deformation mechanism in the cave mainly includes soft rock plastic flow and progressive loosening expansion. The soft rock plastic flow caused phenomena such as side wall bulging, top pressure and steel arch distortion, and the progressive loosening and expansion caused the collapse of the tunnel face and surface cracks. Finally, according to the principles of the New Austrian Method, temporary support (transverse bracing + vertical bracing) + grouting anchor pipe + spray-mixing coordinated support was used to construct the pipe shed at the same time, and the support was optimized, the leading small conduit was encrypted, and added Measures such as temporary invert and lock-foot anchor pipe have successfully dealt with the large deformation section of the collapse, and the treatment effect is good, which can provide reference and reference for similar projects.
Temperature stress analysis of the overlong concrete structure in the basement of the Shangshenbei block project in Hunnan New City
Authors: Zhao Ran , Wang Kai Wei
Published: June 2021

This paper is based on a typical project in Shenyang Shangshenbei Block Project, using Midas software to analyze the temperature stress of the basement concrete structure and the temperature stress changes of various parts of the basement, combining the conditions and characteristics of the concrete structure cracks, and putting forward optimization suggestions and effective resistance. Cracking measures, through the implementation of measures, effectively reduced the occurrence of cracks and ensured the stability of the structure.
Sr-Nd Isotope Composition of Uraniferous Leucogranites in the Gaudeanmus area, Central Damara Belt, Namibia
Authors: Chen Jinyong , Fan Honghai , Wang Shengyun , Gu Dazhao
Published: June 2021

The leucogranite-hosted uranium deposit in Namibia is a well-known intrusive uranium deposit in the world. In this paper, a systematic study of Sr-Nd isotopes has been carried out on uranium mineralized leucogranites in the Gaudeanmus area, Namibia. The results show that uranium bearing leucogranites were formed in the post-orogenic extensional environment, the εNd(t) values of the rock are from -13.5 to -17.4, with the initial 87Sr/86Sr ratios of 0.73035 ∼ 0.79345; and the ages of two-stage Nd model are between 2.32 ∼ 2.63 Ga. The Sr-Nd isotopic geochemical results of the pre-Damara basement, Damara sequence and uraniferous leucogranites indicate that the contribution of uranium rich pre-Damara basement to the ore-forming materials is dominant during the main metallogenic epoch of magmatic crystallization differentiation, while the extra uranium mineralization at the later hydrothermal stage may be from the primary uranium minerals such as uranite and coffinite.
Study on diagenesis and diagenetic evolution of reservoir in Wuerxun depression
Authors: Peng Wei , Zhou Yue
Published: June 2021

Wuerxun depression is one of the main oil-bearing depressions in the middle of the Hailar District Basin with high exploration degree. With the deepening of exploration degree, the pore structure and distribution law of tight reservoir in trough are not clear. In this paper, through the combination of quantitative and qualitative, micro and macro, following the idea of “phenomenon characterization, essence exploration, law summary”, the diagenesis analysis and diagenetic evolution of tight reservoirs are studied to find areas with relatively good reservoir properties in the depression, which provides theoretical basis for tight reservoir exploration. Diagenesis controls the formation, evolution and distribution of the reservoir. The diagenesis of the reservoir in this area mainly includes compaction, cementation and dissolution, thus forming five kinds of secondary dissolution pores (intergranular dissolution pore, feldspar and debris dissolution pore, mold pore, interstitial dissolution pore and dissolution fracture). Vertically, the physical properties of the reservoir are generally poor, but the reservoir is well developed locally. The reservoir is well developed at 1300-1900m and 2300-2700m in Wuerxun depression.
Study on the Factors Affecting the Design of Deep Backfill Foundation Pit and the Factors Affecting Soil Construction Disturbance
Authors: Yu-Chen JI , Jun Ao , Bin Wang , Jian-Dong Niu
Published: June 2021

Water is an indirect construction disturbance factor, which has important influence on the stability evaluation and analysis of foundation pit slope engineering. The study is mainly aimed at the deep backfill, the mechanical parameters are not uniform, and the effect of water on its mechanical parameters is great. The mechanical parameters of the backfill under different moisture content were measured by static triaxial shear test. The results show that the cohesion, internal friction angle and shear strength of the backfill are attenuated with the raise of the water content, the cohesion and internal friction angle of the attenuation law showed a linear re-gentle trend, and the shear strength of the decay trend gradually slowed down. The simulation results show that the mechanical parameters of backfill are reduced with the increasing number of saturation-dehydration cycles. The first degree of decay is the most significant, and finally tends to a certain value. The connection between the deterioration coefficient and the cycles follows the negative exponential function, and the mathematical expression of water deterioration was obtained finally. The study analyzes the damage mechanism of water in the construction disturbance, which has some theoretical support for the stability evaluation and disaster mitigation of the foundation pit.
Hydrophobic Modification of a Slag-based Geopolymer Coating
Authors: Zhu Chunyan , Guo Yaoxiang , Wen Zhiwen , Zhou Yu , Zhang Liangwei , Wang Zhihan , Fang Yuan , Long Wujian
Published: June 2021

The durability of geopolymer coatings is significantly influenced by water infiltration. In order to reduce the ingress of water, a slag-based geopolymer was modified respectively using methylsilicone oil (MSO) and organic silicon agent (OSO). For the characterization of the surface interaction between geopolymer and liquid, the contact angle, surface energy and critical surface energy of geopolymer were measured by a novel and accurate bubble method. Results show that surface hydrophobic modification of geopolymer is completely achieved by MSO modifier due to the increasing contact angle on the surface of geopolymer and the surface energy of geopolymer decrease to a certain extent. The critical surface energy curve is not only can describe wetting performance of the geopolymer, but also can predict the wetting feature of a specific liquid on the surface of the geopolymer intuitively and quickly.
Construction Characteristics and Design Strategy of the “Constant-holistic Shadow” in Mountainous Urban Area in Hot Summer Zone
Authors: Liu Yingqi , Gong Zhaoxian , Luo Guohui , Li Yinan
Published: June 2021

The sunlight in summer is generally strong in hot summer zone, so the long-lasting shadow is conducive to people’s outdoor activities for a long time. Creating a space with “Constant-holistic Shadow” has become an important way to improve the outdoor thermal comfort. However, with special shadowing condition featuring in a varied topography with big vertical height, the sunshine shadowing formation in mountainous urban area is significantly different from that of plain area. Therefore, it is necessary to take the special shadowing conditions into consideration in exploring the influence and relevance on the “Constant-holistic Shadow” construction. This paper analyzed the characteristics of outdoor spatial morphology and shadow forming elements in mountainous urban areas, revealed the correlation between the characteristics and “Constant-holistic Shadow” space, and expounded the main design strategies of “Constant-holistic Shadow” space in mountainous urban areas so as to provide ideas and strategic guidance for more effective construction of “Constant-holistic Shadow” space in mountainous urban areas.
Physical model test study on the working performance of integrated foundation pit supporting structure
Authors: Liu Zhan-Bo , Ren Jin-Ming , Li Shu-Yi , Wang Jun-Jie
Published: June 2021

The integration of underground single structure and retaining structure is a new type of foundation pit support, and its working performance needs to be further studied. The physical model test was carried out on the diaphragm wall structure of “two walls in one” in this paper. The soil settlement and the earth pressure of the outside of the foundation pit and the stress of the integrated supporting structure were analyzed when the excavation depth is different. The analysis showed that the settlement of soil behind the wall gradually increased with the increase of excavation depth of the foundation pit. when it was 1H

e
away from the diaphragm wall, the maximum of soil settlement occurred, which was 0.08%H

e
(H

e
is the maximum excavation depth). With the increase of excavation depth, the state changed from static to active. Under the same condition, the bending moment of the wall increased first and then decreased with the depth. The reverse bending point is near 1.23H

e
.
Study on the influence of tectonism on bauxite mineralization and exploration: a case study of the Luoyang Yellow River Basin, China
Authors: Sun Fengyu , Zhou Qikai , Cao Gaoshe
Published: June 2021

With the increasing demand for mineral resources, the exploration work needs to be strengthened, and the factors affecting the layout of exploration projects need to be further studied. In this paper, the bauxite deposits in the Luoyang Yellow River Basin, Western Henan, are the research objects. According to the geological background and mining characteristics, the influence of tectonism on bauxite mineralization and exploration is comprehensively analyzed. The comprehensive exploration methods (such as geology analysis, drilling engineering, geophysical prospecting, and testing) are used to evaluate the metallogenic prospect of the study area. Through field practice, good prospecting results have been achieved.