bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correlation between the Concentration of DNA and Electrical Bioimpedance
Authors: Hernández Angélica , Ames Gerardo , Sánchez Virginia , Gómez Modesto , Sánchez Jennifer , Pérez Nadia M , Castillo Itsi A , González César A 
Published: November 2021

AbstractBiosensors have recently been used for the identification and genetic characterization of diseases such asSalmonella, human papilloma, and breast cancer. The aim of this study was to examine the relationship between different concentrations of Deoxyribonucleic Acid (DNA) and the corresponding values of magnitude and phase of Electrical Bioimpedance (EBI). Functions that characterize the correlation of DNA with these two parameters were derived from linear regression by means of the least squares method. According to the results, it is feasible to determine the concentration of DNA from EBI measurements (at a specific frequency) of magnitude and phase, taking into account the corresponding linear functions. The present findings indicate the feasibility of using EBI measurements of magnitude and phase as a biosensor for the detection of genes associated with genetic and infectious diseases.
Simulation of impact load modulation device based on drill string vibration
Authors: Lu Xiaopeng , Liao Hualin , Wang Huajian , Niu Wenlong , Liu Jiansheng 
Published: November 2021

Abstract
The longitudinal vibration of the bottom drill string is violent and the law is complex during the deep well drilling. The vibration of the drill string brings many adverse effects on the drilling pipe fracture and bit trampoling. Generally speaking, the effective way to control the vibration of drill string is to install damping device in bottom hole. The research group proposes a device that uses the longitudinal vibration energy of the deep well drill string to modulate the impact dynamic load, which converts the vibration energy of the downhole drill string that is not conducive to drilling into the mechanical impact energy that improves the rock breaking capacity of the bit. The impact load modulation device can use the drill string to apply the “mechanical WOB” and the differential pressure between the upper and lower piston to produce the “hydraulic WOB”, The simulation results show that the adjustable range of output load is 2 ~ 7T, and the change of each time is about 2T. The modulation law of impact load under the influence of longitudinal vibration of drill string and different parameters is analyzed. Through ground experiment and simulation, the damping performance and speed-up effect of the modulation device are compared and analyzed, and the impact load output characteristics of the device are analyzed, which provides a thinking for the design of damping and pressurization tools.
Steering Wheel AGV Path Tracking Control Based on Improved Pure Pursuit Model
Authors: Wu Yiyang , Xie Zhijiang , Lu Ye 
Published: November 2021

Abstract
Aiming at the path tracking problem of the AGV transfer platform of an Optical module installing and calibrating system, this paper designs a pure pursuit control strategy in which the preview distance changes adaptively according to the current speed of AGV and the curvature of the reference path. Firstly, AGV kinematics model and pure pursuit model are established according to the geometric relationship. Then fitness function is established with tracking deviation and steering stability, and Particle swarm optimization (PSO) algorithm is used to optimize the preview distance of pure pursuit model of AGV under various working conditions. During the tracking process, AGV selects the optimal preview distance according to the curvature of the reference path and the current speed. The simulation experiment results show that the improved pure pursuit control strategy containing curvature information of reference path can improve the adaptability of AGV when it is tracking complex path, guaranteeing tracking accuracy and steering stability.
Coordination of synchronous compensators and converters to improve the commutation failure recovery performance in HVDC systems
Authors: Wu Kuayu , Zhang Jiancheng , Zhou Yongzhi , Zhu Yuhong 
Published: November 2021

Abstract
A novel control strategy of synchronous compensators and converters is proposed to increase the ability of line commutated converter (LCC) based HVDC systems to successfully recover from commutation failures (CFs). The dynamic var support is one of the most important factors, which impact the commutation process. Many synchronous compensators have been implemented to enhance the transient voltage stability for improving the CF recovery performance. However, the traditional automatic voltage regulator (AVR) of synchronous compensator may not be suitable for the commutation voltage support, because the transient var demand of converters during the CF recovery is neglected. In our work, the voltage control will be adaptively adjusted, depending on the state of converters. Case studies based on simulations in PSCAD/EMTDC show that the proposed strategy can improve the performance of fault recovery from CF.
Research on relative orientation method of oblique aerial photography based on basic matrix
Authors: Wang Zehong , Xiao Long 
Published: November 2021

Abstract
After the oblique aerial photography technology is used to collect the stereo image, it is necessary to use the relative orientation method to check the image parameters. After the rectification process is completed, the 3D software is used to draw the 3D model to meet the subsequent application requirements. The author of this paper analyzes the difficulty of the matching and aerial photography, including affine transformation cannot successful transformation, influence there covered phenomenon and characteristic finishing is difficult, the combination of fundamental matrix tilt aerial photography as a method of relative orientation, through the study of oblique aerial photography based matrix as precision control points, its aim is to continuously optimize tilt aerial photography as the content, improve the use value of collation results.
Research on Digital Twin Virtual Model of UHV Core Power Equipment
Authors: Zhang Shiling 
Published: November 2021

Abstract
In this paper, voltage equalization, corona prevention and noise reduction are studied by using finite element calculation method and multi-objective optimization algorithm for UHV substation, series compensation circuit, transmission line, DC valve hall and outdoor field. The calculation model of multi parameter and multi-objective optimization design is established, the optimal configuration parameters of voltage equalizing structure are obtained, the electric field distribution uniformity and structure rationalization are realized, the corona discharge is effectively restrained, the key technology of voltage equalizing and anti corona is solved, the cost is reduced, the efficiency is improved, and a simulation calculation and optimization design platform with independent intellectual property rights is formed. The research results have been successfully applied to UHV projects in China.
DOA Estimation of a Space-limited MIMO Radar with High Degree of Freedom
Authors: Yue Shijie , Hu Guoping , Zhan Chenghong , Zhang Yule , Zhu Mingming 
Published: November 2021

Abstract
Aiming at the problem of the small aperture of the traditional MIMO radar with virtual degrees of freedom, this paper designs a high degree of freedom space-limited MIMO radar. Both the transmitting and receiving elements of this radar adopt a sparse array structure. Array composition, the receiving array element is composed of a single array element and a uniform linear array. The number of virtual array elements can be realized by using array elements. Compared with the traditional sparse array MIMO radar with the same number of elements, the designed space-limited sparse array MIMO radar has a larger aperture. Experimental simulations verify the superiority of the space-limited MIMO radar angle estimation.
A Research on Modulation in Digital Communication System
Authors: Niu Xinyu , Wu Jingdong , Zhang Linen 
Published: November 2021

Abstract
With the development of network and communication technology in modern society, WiFi technology has become an indispensable part of people’s lives. WiFi shows its future application prospects with its wireless portability and multi-user access. This paper briefly introduces the meaning and development of WiFi technology and predicts its future development trend. The communication modulation technology QPSK, 16QAM in WiFi is described in detail, and its characteristics are compared by systemview and MATLAB software. Finally, we summarize the common techniques in WiFi.
Research on Simulation and Test of Spatial Isolation Based on Geographic Information
Authors: Wang Yuan , Tan Wei , Kong Rong , Ren Zhaorui 
Published: November 2021

Abstract
In the process of site selection for the deployment of distributed systems, in order to solve the problem of inaccurate spatial isolation simulation results caused by the large influence of complex geographic information such as terrain and weather on the propagation of radio waves, and to solve the problem of inefficient and inefficient spatial isolation testing. This paper proposes to select suitable propagation models for different geographical information in different regions, clarifies the simulation calculation method, and proposes a test method to accurately determine the direction of the transceiver antenna for the minimum spatial isolation. By comparing and analyzing the simulation calculation results and test verification results, correction parameters such as simulation system error, atmospheric absorption loss, and geological absorption loss are proposed. This article analyzes and studies the correction value of radio wave transmission loss of S-band electromagnetic signal under different geographic information conditions such as snowfall and iron ore through an example. It can provide reference values for some of the influencing factors of electromagnetic signal propagation loss under geographic information conditions, and it can improve the accuracy of the simulation calculation results of the spatial isolation under the conditions of geographic information.
Design of transceiver based on functional programming
Authors: Zhao Zhuomao , Yang Yujie , Long Xue , Cui Hongwei 
Published: November 2021

Abstract
This paper discusses the setting of transceiver based on functional programming, and decouples the differences between communication protocol and network transmission protocol from the specific business implementation. In the actual application, the service implementation is set up. When the communication protocol changes, the function can be realized only by modifying the communication protocol, which improves the readability of the program and reduces its maintenance overhead
An Improved PMF-FFT Algorithm Based on Hamming Window
Authors: Cheng Lingfeng , Ni Shuyan , Chen Shimiao 
Published: November 2021

Abstract
When the rocket uses low-orbit satellite space-based measurement and control, due to the relatively large Doppler shift in relative motion, a spread spectrum system is needed to improve anti-interference; the spread spectrum signal under high dynamic conditions often uses partial matched filtering based on FFT (PMF-FFT) algorithm, but due to the introduction of FFT, this algorithm has serious scallop loss, which affects the system’s capture performance. Through the improved method of adding a Hamming window to the system, theoretical analysis and simulation show that it effectively suppresses scallops. Loss has a certain meaning for the acquisition of spread spectrum signals.
A time-division correction method for adaptive optics system
Authors: Yuan Guangfu , Zhao Lirong , Wu Peijian , Wang Weijie 
Published: November 2021

Abstract
An adaptive optics system can measure and compensate the wavefront distortion caused by dynamic disturbance in real time. It is usually used for astronomical observation and other occasions. According to the current technology, it is only suitable for small field of view optical system or point target, but not for ground extended target detection. In order to solve this problem, a correction method is proposed: firstly, the sub aperture image of wavefront sensor is divided into several sub regions, each sub region corresponds to a certain light direction or field angle range; secondly, calculate the offset of the image feature points in each sub region, and an image with good correction effect in a field of view in this direction is obtained; the last step is to measure each sub region one by one and combine these images into a full frame image. Through comparison, it is found that the method proposed in this paper is essentially to divide the extended target into multiple point light sources for correction.
Analysis of eddy current loss in magnetic coupling based on three-dimensional finite element calculation
Authors: Wang Xiaoyue , Cai Liang , Mao Yanqin , Guo Wanjun 
Published: November 2021

Abstract
Considering the end effect, the three-dimensional finite element calculation model of the magnetic coupling is established. The three-dimensional distribution nephogram of the induced current and eddy current loss on the isolation cover is obtained, and the distribution trends of the two are consistent. The influence of size, material, and operating condition of magnetic coupling on eddy current loss is studied. The results show that the selection of isolation material with high resistivity and the reduction of isolation thickness are helpful to reduce the eddy current loss. The higher the rotating speed of the magnetic coupling, the greater the eddy current loss. At the same speed, the greater the load, the greater the magnetic declination, the smaller the eddy current loss. The research results can provide a reference for reducing energy loss and cooling structure design of magnetic coupling.
Fluid-Structure Interaction Approach to Single Particle in a Square Microchannel
Authors: Li Xiang , Lin Ying 
Published: November 2021

Abstract
Inertial microfluidic technique has been widely applied on particle/cell manipulation and detection. To understand the physical principle of this technique more detailed, the interaction of fluid and particle was studied through the Fluid-Structure Interaction (FSI) method. The equilibrium positions of finite-size particles with different diameters were simulated at moderate Reynolds numbers. The flow structure around two typical particles was analysed. The vortex in the front of the particle retards particle’s translation leading to the lag velocity increasing. Finally, the rotation velocity and the rotational-induced force analysed quantitatively to demonstrate that particle’s self-rotation significantly promotes its inertial migration.
Optimization and Application of D850 Dredge Pump Blades under Medium Coarse Sand Condition of Cutter Suction Dredger
Authors: Zhuang Haifei , Liu Mingming , Wu Yongding 
Published: November 2021

Abstract
Regarding wear issues of a dredge pump’s impeller as a cutter suction dredger transports medium coarse sand slurry, blades of the D850 dredge pump are modified and optimized, which extends the distance from the blade inlet root to the impeller suction and avoids damages of the impeller suction anti-wear ring. Analyses via computational fluid dynamics (CFD) simulation show that the head and the efficiency after blade modification have little changes compared with before optimization in the construction flow range of 10000-12000 m3/h under coarse sand condition. While it improves the flow field of impeller’s channels, decreases the vortex at the inlet root of the blades, ensures more uniform distribution of the solid particles. Meanwhile, this is beneficial to reductions of the channels’ wears. Applications from constructions show some improvements in the wears of the blade root. Through the construction data comparison, after replacing the modified impeller, dredging productivity will be increased by 15.1% and the fuel consumption per 10000 m3 will be then reduced by 11.5%.
Singularly Perturbed Solutions for a Class of Thermoelastic Weakly Coupled Problems
Authors: Bao Liping , Shuai Xin , Wu Liqun 
Published: November 2021

Abstract
Based on the basic equation of Green Lindsay (G-L) theory, the thermoelastic weak coupling problem under the basic equation is discussed, that is, two thermal relaxation parameters are added to the constitutive equation, the influence of the coupling term on the temperature field and elastic field is considered, and the asymptotic solution of the governing equation is constructed. Firstly, in order to obtain the asymptotic solution, the singularly perturbed expansion method is used.Then,combined with the corresponding boundary conditions, the partial differential equation method is used to solve the external solution and the boundary layer correction term. Secondly, in the case of weak coupling, the uniformly efficient estimation of the remainder of the asymptotic solution is obtained by using Gronwall inequality, so as to obtain the uniformly efficient of the formal asymptotic solution. Finally, the first term of the asymptotic solution is numerically analyzed by using the singularly perturbed numerical method. The present work will be conducive to the analysis of thermoelastic processes and numerical simulation of different materials in the case of weak coupling.
Review of Calibration and Improvement Methods of Light- Scattering Airborne Particle Concentration
Authors: Gao Z L , Cheng Q D , Zeng G L , Wen Y , Li G F , Chen J , Dong Y B , Ji Q Z 
Published: November 2021

Abstract
Clean environment and its internal airborne particle concentration have been paid more and more attention, the demand for use and measurement of light-scattering airborne particle counter, as the main instrument for measuring airborne particle concentration, has increased synchronously. This paper untangles the worldwide standards and specifications for calibration of light-scattering airborne particle counter, analyses the shortcomings of traditional comparative calibration method, introduces the research progress of non-traditional calibration method based on statistical analysis of membrane and scanning electron microscope, then based on the theory of discrete phase model and gas-solid fluid dynamics, puts forward two improved calibration methods to obtain more reliable "true value" of the number of the standard particles passing through the calibrated OPC, to provide an innovative idea for improving the measurement accuracy of airborne particle concentration worldwide.
Study on Micro Recoil Mechanism of the Weapon with a Nozzle and Two Chambers Separated by a Partition
Authors: Ma Longxu , Qiu Ming , Song Jie , Si Peng , Liao Zhenqiang 
Published: November 2021

Abstract
In order to improve the recoil reduction ability of the weapon without reducing the projectile velocity, the weapon with a nozzle and two chambers separated by a partition is proposed. Taking the 35 mm caliber grenade launcher as the research object, the physical model of its launching process is proposed, and the one-dimensional two-phase flow interior ballistic model is established. MacCormack difference scheme is used to calculate the coupling of multiple physical fields formed by front and rear chambers and nozzles. Compared with the calculation results obtained by using the classical interior ballistic model, the correctness of the two-phase flow interior ballistic model is verified. The effects of the charge amount in the rear chamber and the size of the air guide hole in the barrel on the internal ballistic performance of the weapon with a nozzle and two chambers separated by a partition. The calculation results show that compared with conventional weapons, the recoil impulse can be reduced with maintaining muzzle velocity, and the recoil reduction efficiency can reach 72.27%, which is of great significance for improving weapon performance.
Numerical Investigation on Radiation Effect in Transpiration Cooling
Authors: Qian Kang , Liu Taolue , He Fei , Wang Meng , Tang Longsheng , Zhou Jianxing 
Published: November 2021

Abstract
This paper proposed a numerical strategy which could achieve the coupled modeling and solving of transpiration cooling with external high-temperature gas flow and especially take the radiation effect into account. Based on the numerical strategy, the heat and mass transfer characteristics of the transpiration cooling in a high-temperature gas channel were studied, and the radiation effect and corresponding influence factors were analyzed. The results indicated that the radiative heat flux takes an important role in the heat transfer between the transpiration cooling and external high-temperature gas flow which may reach 40% under the operating condition considered in this work, and the radiation absorption from the coolant is more obvious near the downstream wall. As the wall emissivity increases, the radiation heat transfer in the downstream area of the porous wall is enhanced significantly and thereby the wall temperature there increases, as the result, the uniformity of the temperature distribution on the whole porous wall is improved to some extent.
Simulation Study on the Influence of Injector Coupling Leakage on Fuel Injection
Authors: Zhang Ziwei 
Published: November 2021

Abstract
In order to study the effect of fuel leakage of an ultra-high pressure common rail injector control valve coupling on fuel injection performance, a simulation model was established by AMESim and the accuracy was verified by fuel injection test data. The leakage law of couples with different clearances was analyzed by using numerical simulation method and then the influence of control valve coupling on fuel injection performance was analyzed. The results demonstrate that the increase of the matching clearance of the slide valve coupling makes the start time of needle valve advanced and delay its end time. The injection rate and injection duration increase with the increase of the matching clearance of slide valve coupling. The increase of the matching clearance of the control plunger coupling keeps the start time of the needle valve unchanged at first, and then delay slightly, while the end time remains unchanged at first, and then show the trend of advance. The injection rate and injection duration decrease with the increase of the matching clearance of plunger coupling.
Investigation of Huge Wave in Gas-Liquid Two-Phase Churn Flow
Authors: Zhang S , Shao Q Q , Hu B , Wang K 
Published: November 2021

Abstract
Churn flow frequently occurs in power plants, chemical engineering, petroleum, and other industrial applications. Due to its chaotic nature, churn flow has a significant influence on safety and management control. As one of the essential characteristics of churn flow, depth knowledge of the huge wave is crucial for a better understanding churn flow. However, relevant studies on these issues are still in shortage because it is difficult to capture its behaviours experimentally. In this study, we employed the high-speed camera to capture the evolution and properties of huge waves under churn flow conditions in a vertical pipe. The inner diameter of the pipe is 19 mm. Based on the observation, the flooding of the falling film in churn flow is demonstrated to be the slug/churn transition mechanism. Additionally, the liquid distribution in the cross-section of the tube is provided and discussed in detail. Compared with the existing experiment data, we carefully analyze the properties of huge waves, such as frequency and amplitude.