bluuebunny/crossref_metadata_2025 huggingface dataset:
More accurate ro-vibrational energies for SiF
+(X
1Σ+) molecule
Authors: Yanar Hilmi
Published: February 2022

The most appropriate potential energy function for the X
1Σ+ state of SiF+ molecule has been specified by comparing the vibrational energies obtained via special cases of the general molecular potential (GMP) which are Morse, improved Rosen-Morse, modified Rosen-Morse, improved Manning-Rosen and Tietz potentials with the vibrational energies obtained in the presence of improved generalized Pöschl-Teller (IGPT) potential and experimental data. It has been shown that the improved Rosen-Morse potential is better than the other well-known potential energy functions in fitting experimental energies of SiF
+(X
1Σ+) molecule. By using relativistic rotational-vibrational energy eigenvalue relation for Rosen-Morse potential in improved form which is acquired by solving the Dirac equation under the GMP and Pekeris type approximation, the more accurate ro-vibrational energies of SiF
+(X
1Σ+) molecule have been obtained. It has been demonstrated for SiF
+(X
1Σ+) molecule that in order to procure more proper ro-vibrating energies for the SiF
+(X
1Σ+) molecule, a Pekeris-type approach to the centrifugal term is better than the improved Greene-Aldrich in getting more accurate ro-vibrational energies.
BOSS Correlation Function analysis from the Effective Field Theory of Large-Scale Structure
Authors: Zhang Pierre , D'Amico Guido , Senatore Leonardo , Zhao Cheng , Cai Yifu
Published: February 2022

After calibrating the predictions of the Effective Field
Theory of Large-Scale Structure against several sets of simulations,
as well as implementing a new method to assert the scale cut of the
theory without the use of any simulation, we analyze the Full Shape
of the BOSS Correlation Function. Imposing a prior from Big Bang
Nucleosynthesis on the baryon density, we are able to measure all
the parameters in ΛCDM + massive neutrinos in normal
hierarchy, except for the total neutrino mass, which is just
bounded. When combining the BOSS Full Shape with the Baryon
Acoustic Oscillation measurements from BOSS, 6DF/MGS and eBOSS, we
determine the present day Hubble constant, H
0, the present day
matter fraction, Ωm, the amplitude of the primordial power
spectrum, A
s, and the tilt of the primordial power spectrum,
n
s, to 1.4 %, 4.5 %, 23.5% and 7.6% precision,
respectively, at 68 %-confidence level, finding H
0=68.19 ±
0.99 (km/s)/Mpc, Q
m=0.309± 0.014, ln (1010
A
s
)=3.12+0.21
-0.26 and n
s=0.963+0.062
-0.085, and we
bound the total neutrino mass to 0.87 eV at 95 %-confidence
level. These constraints are fully consistent with Planck results
and the ones obtained from BOSS power spectrum analysis. In
particular, we find no tension in H
0 or σ8 with Planck
measurements, finding consistency at 1.2σ and 0.6σ,
respectively.
Possibility of Searching for Accreting White Dwarfs with the Chinese Space Station Telescope
Authors: Xie Wei , Chen Hai-Liang
Published: February 2022

Accreting WDs are very important for the studies of binary evolution, binary population synthesis and accretion physics. So far, there are a lot of accreting WD binaries with low accretion rates, such as cataclysmic variables, detected by different surveys. However, few accreting WD binaries with high accretion rates have been detected. In this paper, we studied the spectrum properties of accreting WD binaries and investigated whether accreting WD binaries with high accretion rates can be detected by the Chinese Space Station Telescope (CSST). We found that some accreting WD binaries with high accretion rates can be distinguishable from other types of stars with (NUV − y, u − y), (NUV − r, u − g), (NUV − i, u − g), (NUV − z, u − g) and (NUV − y, u − g) color–color diagrams. Therefore, some accreting WD binaries with high accretion rates can be detected by the CSST.
Fast-ion transport and toroidal rotation response to externally applied magnetic perturbations at the ASDEX Upgrade tokamak
Authors: Cano-Megias P. , Viezzer E. , Galdon-Quiroga J. , Sanchis L. , Garcia-Munoz M. , Cruz-Zabala D.J. , McDermott R.M. , Rivero-Rodriguez J.F. , Snicker A. , Suttrop W.A. , Willensdorfer M.
Published: February 2022

This paper studies the effect of 3D magnetic perturbations (MPs) on fast-ion confinement, and its impact on the toroidal rotation velocity profile. Two low collisionality H-mode experiments carried out at the ASDEX Upgrade tokamak have been analysed. The two discharges feature different magnetic field helicity (q
95), and differences in the velocity-space and level of fast-ion losses are observed. A new analysis technique has been developed that sheds light on the dependencies between fast-ion losses and toroidal rotation, providing for the first time correlation patterns resolved in radius and velocity space of the lost fast-ions. The correlation intensifies towards the plasma edge and is strongly dependent on the orbit topology of the lost fast-ions. The ASCOT orbit following code has been used to characterize the fast-ion resonant transport and beam driven torques, using the vacuum approach and including plasma response (PR). The change of the toroidal canonical momentum, which serves as figure of merit for resonant fast-ion transport, has been calculated with ASCOT. The beam geometry and q
95 are found to have a strong impact on the fast-ion transport and losses. The fast-ion transport induced by the MPs affects the beam driven torques. The effect of the changes of the j × B and collisional torques on plasma rotation is analysed using the torques simulated by ASCOT and simple momentum balance calculations. For the low q
95 = 3.8 discharge, which benefits from a resonant amplification, we find excellent agreement with the measured variation of the toroidal velocity. For the high q
95 = 5.5 discharge, the inclusion of the PR improves the comparison with experimental data with respect to the vacuum estimation, but still some differences with experiments are observed. This suggests that other non-resonant effects could play a role for the determination of the toroidal rotation profile.
A study of non-linear Langevin dynamics under non-Gaussian noise with quartic cumulant
Authors: Jana Chandan
Published: February 2022

We consider a non-linear Langevin equation in presence of non-Gaussian noise originating from non-linear bath. We claim, the parameters in the Langevin equation are not physical. The physical parameters are obtained from a path-integral description of the system, where the Langevin parameters are related to the physical parameters by renormalisation flow equations. Then we compute both numerically and analytically the velocity two point function and show that it saturates to the bath temperature even in presence of non-linearity. We also find the velocity four point function numerically and show that it saturates to the analytically evaluated thermal velocity four point function when the non-linear fluctuation–dissipation relation (FDR) Chakrabarty and Chaudhuri (2019 SciPost Phys.
7 013) is satisfied. When the non-linear FDR, which is a manifestation of time reversibility of thermal bath, is violated then the system does not seem to thermalise. Rather, its velocity four point function settles to a steady state.
Microcanonical conditioning of Markov processes on time-additive observables
Authors: Monthus Cécile
Published: February 2022

The recent study by De Bruyne et al (2021 J. Stat. Mech. 123204), concerning the conditioning of the Brownian motion and of random walks on global dynamical constraints over a finite time-window T, is reformulated as a general framework for the ‘microcanonical conditioning’ of Markov processes on time-additive observables. This formalism is applied to various types of Markov processes, namely discrete-time Markov chains, continuous-time Markov jump processes and diffusion processes in arbitrary dimension. In each setting, the time-additive observable is also fully general, i.e. it can involve both the time spent in each configuration and the elementary increments of the Markov process. The various cases are illustrated via simple explicit examples. Finally, we describe the link with the ‘canonical conditioning’ based on the generating function of the time-additive observable for finite time T, while the regime of large time T allows us to recover the standard large deviation analysis of time-additive observables via the deformed Markov operator approach.
Research and Analysis on Cavitation of Different Structures of Cone Valve Ports in Pure Water
Authors: Zhou Xinjian , Liu Siyu , Lu Yongfeng , Zhang Hongbing , Shao Hongbin , Tian Yan
Published: February 2022

In order to study the cavitation problem of the pure water medium hydraulic poppet valve, a three-dimensional model of the poppet control valve under a rated pressure of 31.5MPa was established with the help of Soildworks software, and the poppet valve port model was simplified into a two-dimensional symmetrical model with AutoCAD software. Based on the FLUENT software, the liquid-gas two-phase flow simulation of the cavitation phenomenon in the flow field of the poppet valve is carried out, and the cavitation distribution and intensity change rules of the three valve port structures at three opening degrees are obtained. The results show that for the pure water medium hydraulic cone valve, the cavitation distribution in the new stepped structure is significantly reduced and the strength is significantly reduced under the same opening degree.
Terminal Iterative Learning Scheme for Consensus Problem in Multi-Agent Systems with State Constraints
Authors: Zhang Yan , Luo Zijian , Xiong Wenjun
Published: February 2022

In this paper, we investigate the consensus problem of multi-agent systems with state constraints. To achieve the consensus effectively, the terminal iterative learning approach is proposed. This learning strategy is designed without the tracking error. And the consensus state is obtained by the the information interaction between agents. Meanwhile, the constraint condition holds in terms of our learning strategy. It shows the consensus conditions ensure the achievement of the constraints. Finally, a numerical simulation is given to illustrate the effectiveness of the main results.
Design of Intelligent Garbage Classification System Based on Internet of Things Technology
Authors: Tan Yanping , Guo Wei , Yang Ke , Huang Jingjing , Yang Zhengping
Published: February 2022

With the increasingly prominent problem of environmental pollution, it is extremely urgent to carry out garbage classification. This paper designs an intelligent garbage classification system based on Internet of Things technology, The system is mainly composed of relay driving circuit, infrared induction, metal detection and humidity detection modules. Single chip microcomputer and multi-channel sensors are used to collect and process related data to realize metal garbage recovery, dry garbage and wet garbage classification and delivery, and the collected related data are displayed on the display screen through serial communication. The experimental results show that the system has the characteristics of simple structure, stable performance and convenient operation, which provides a feasible solution for the current garbage classification and treatment.
Accelerated Life Test Technology Based on Unilateral Confidence Estimation
Authors: Cao Yaolong , Zhao Hailong , Xi Shanbin , Peng Hao
Published: February 2022

The test principle, test type and test model of accelerated life test, as well as the data processing method of unilateral confidence estimation are introduced. Taking the enhanced field effect transistor as an example, a reasonable accelerated life test scheme is formulated by selecting the appropriate accelerated test model and stress conditions. After the test, the life characteristic value of the device under normal stress level is calculated according to Arrhenius equation and unilateral confidence estimation method. Through research, an accelerated life test method for processing non failure data is provided.
The Analysis of High-Speed Low-Power Dynamic Comparators
Authors: Chen Zhenxiang , Ni Yuheng , Xiong Zhenghao
Published: February 2022

This article reviews 5 different articles on optimizing comparators and focuses on their innovations. Many innovative methods are used to get a higher comparison speed, lower power consumption and degraded noise comparator. Many novel methods such as connecting the conventional two-stage dynamic comparator to a transconductance-enhanced latching stage, adding a charge pump to the Miyahara’s comparator, engendering two propagating edges in two inverter loops and measuring the distance between the two edges to compare different input voltage and using an inverter-based input pair which is powered by a floating reservoir capacitor can significantly achieve these goals. What’s more, a three-stage feedforward fully dynamic comparator with an extra parallel feedforward path, which is a completely innovatory and newly designed comparator, is also proposed.
Research on intelligent lighting mode based on implicit humancomputer interaction
Authors: Pei Yuezhou , Wang Qi
Published: February 2022

In this paper, through the research based on implicit interaction elements, the important role of autonomous implicit feedback in intelligent lighting scenes is pointed out, and the lighting control method based on IILCM mode is proposed. The autonomous implicit feedbacks lighting system which is consisted of two components with sensors and MCU is designed and implemented. Describes the hardware structure and software module functions of the system, as well as the design principles of intelligent lighting products in the implicit interactive mode. The experiment shows that, for different users, the system can effectively adjust its brightness output adaptively, which can greatly reduce the burden of users using the equipment, and meet the requirements of the implicit interactive mode for light source brightness control.
Simulation and optimization for pressing system of hydraulic brick press based on AMESim
Authors: Zheng HongBo , Li MingJun , Wang ZhouLin
Published: February 2022

In order to solve the problems of impact vibration and roar in the working process of the automatic hydraulic brick press, a simulation model of the hydraulic system was established based on AMESim, and the dynamic simulation analysis of the upper cylinder was carried out to find out the cause of the problem. It was solved by installing a deceleration circuit and improving a pressure relief circuit. Finally, the optimized hydraulic system was simulated and verified, and the results proved that the optimized hydraulic system achieved the desired effect.
Design of various parts of multi-joint bionic fish equipment
Authors: Shang Qingli
Published: February 2022

The multi-joint bionic fish has a convenient and stable structure, small size, and can be used in different occasions. At present, it can be used in normal underwater activities and can effectively solve the difficult problem of underwater exploration. The equipment consists of six parts in total: fish wing forward device, fish wing movement linkage device, single joint connection device, fish tail stabilization device, fish body bending and direction changing device, and driving device. Satisfying the basic requirements can solve the problem of underwater operations.
Troubleshooting and Improvement of Mechanical Overspeed Shutdown of Diesel Generator
Authors: Tang Ran , Wang Shuren , Xiao Biao , Wang Heng
Published: February 2022

This paper introduced the components and functions of control components of a ship automatic power station, with an analysis of the control principle of such station. The fault treatment method and troubleshooting process are elaborated based on mechanical overspeed automatic shutdown fault of the generator. Finally, in view of the problem of 4K6 relay, appropriate improvement measures are proposed.
Research on Fault Diagnosis Technology Based on Deep Learning
Authors: Wang Haisheng , Wei Jian , Li Pengjin
Published: February 2022

This paper introduces the basic theory, research status and challenges of fault diagnosis technology based on deep learning, and expounds the great application prospect of fault diagnosis technology based on deep learning.
Full-Waveform Inversion for Subsurface Penetrating Radar based on Adaptive Bilateral Total Variation Regularization
Authors: Cao Laibao , Liu Tao , Shen Mengmeng , Wang Yujun , Huang Chunlin
Published: February 2022

Full-waveform inversion (FWI) of subsurface penetrating radar (SPR) is one of the most promising techniques for quantitative reconstruction of high-resolution dielectric properties distribution. However, due to the incomplete observation data of surface detection, there is significant ill-posedness in inversion and the inversion accuracy is lower than expected. In this paper, an FWI method for SPR data with adaptive bilateral total variation (ABTV) regularization is proposed. The method utilizes ABTV regularization to supplement the data constraints and retains the anomaly body boundary information. In addition, the regularization function of adaptive weight factor matrix is designed for the limitation of the standard bilateral total variation (BTV) regularization, which considers both the smoothing effect and the edge preservation effect. Synthetic experiment shows that the proposed method can reconstruct the permittivity distribution more accurately from 2-D SPR data.
A distributed photoelectric sensing and simulation training method for the UAV swarm
Authors: Liu Rang , Wu Jian , Zhao Yanjie , Liu Changqing
Published: February 2022

Aiming at the shortage of the training samples in the process of target recognition of the UAV swarm distributed photoelectric sensing system, the distributed photoelectric sensing and training technology based on the loop simulation is studied. This paper discussed the hardware architecture and software architecture of distributed photoelectric sensing and training system, as well as the design of distributed video splicing and target recognition algorithm. Finally, a simple distributed photoelectric sensing hardware in the loop simulation training system applied to UAV cluster was built in the laboratory, and the feasibility of this technology was verified by experiments.
A way to synchronize clocks with the FlexRay bus
Authors: Pang Fengying , Huang Min , Mi Zhaoyang , Zhang Huimin
Published: February 2022

In order to ensure that different systems work together under the same clock, it is necessary to propose a unified time management system and a unified time benchmark, this paper studies the method of clock synchronization based on FlexRay bus, which has been verified by the laboratory to achieve clock synchronization by FlexRay bus, with synchronization accuracy of less than 10us.
Research on the Convergence Application of Satellite Mobile Communication and Wireless Ad Hoc Network
Authors: Cao Lei , Yang Xing
Published: February 2022

The article analyzes the networking modes and main features of satellite mobile communications and wireless ad hoc networks, and proposes to build a dual-function terminal of satellite mobile communications and wireless ad hoc networks. By merging the respective advantages of the two communication modes, the application range of satellite mobile communication can be further expanded, and finally exemplified typical application scenarios.
Polynomial chaos expansion for uncertainty analysis and global sensitivity analysis
Authors: Chen Ming , Zhang Xinhu , Shen Kechun , Pan Guang
Published: February 2022

Uncertainty analysis has received increasing attention across all kinds of scientific and engineering fields recently. Uncertainty analysis is often conducted by Monte Carlo simulation (MCS), while with low convergence rate. In this paper, numerical test examples as benchmarks and engineering problems in practice are studied by polynomial chaos expansion (PCE) and compared with the solutions got by MCS. Results show that PCE approach establishes accurate surrogate model for complicated original model with efficiency to conduct uncertainty analysis and global sensitivity analysis. What’s more, sparse PCE is able to tackle problem of high dimension with efficiency. Hence PCE approach can be applied in uncertainty analysis and global sensitivity analysis of engineering problems with efficiency and effectiveness.
Impact Damage Characteristics of Quartz Fiber and NOMEX Paper Honeycomb Sandwich Panel composite materials
Authors: Zhou Xiang , MA Zhandong , Liu Xiaofei
Published: February 2022

To provide a reference for practical engineering application of fiber composite materials, this work researches on the impact resistance of type-B quartz fiber/modified cyanate ester composite material laminates and NOMEX paper honeycomb sandwich panels. Firstly, low-speed impact tests are carried out on the quartz fiber laminates and the NOMEX paper honeycomb sandwich panels by setting different parameters to analyze the impact energy and punch mass on impact damage; secondly, based on the experimental results, impact responses are analyzed; and the damage morphology of the two composite materials is observed through visual inspection and with the aid of the CT scanning technology. The results show that according to time-load curves, the NOMEX paper honeycomb sandwich panels have two peak load moments, respectively corresponding to the moments when the upper and lower panels are penetrated; the quartz fiber laminates show three different types of failures, namely substrate cracking, fiber fracture and delamination. As for the NOMEX paper honeycomb sandwich panels, two types of damage are found: fiber fracture and honeycomb core extrusion fracture. When the punch mass is constant, the greater the impact energy is, the more serious the damage is; and when the impact energy is constant, the greater the punch mass is, the more serious the damage is.
Applications of Metal-Organic Framework Materials
Authors: Chai Wenkui , Shen Youhong , Wang Jiahe , Zhang Geling
Published: February 2022

Metal-organic framework (MOFs) is a new group of porous crystal materials with ultra-high porosity. Its extraordinary surface area, fine and adjustable void surface characteristics and potential industrial-scale scalability make it an attractive target for further research. By searching for the data, we have integrated and summarized the important applications of MOF materials in many fields, such as catalysis, and its enclosed single metal or bimetallic ions provide efficient and synergistic catalytic ability; In adsorption, the special ionic liquid absorbent overcomes the shortcomings of other materials, greatly improves the chemical stability, reduces the corrosivity, and makes the process more environment-friendly and controllable. However, there are still many challenges, and the high cost and complicated preparation process are urgent problems to be solved at present. We need to have a deeper understanding of the growth mechanism of MOF films, improve their quality and thermoelectric stability, and combine them into low-cost polymer films through more reliable theoretical models to eliminate the defects of MOF materials as much as possible. We will continue to pay attention to the development of MOF materials, summarize the advantages of MOF materials, find out the shortcomings, and propose solutions to provide ideas and references for future research.
Numerical Simulation Research on Slow cook-off of Warhead of DNAN-based Melt-cast Explosive
Authors: Zhang Kebin , Li Wenbin
Published: February 2022

RBOE explosive is a new type of DNAN-based insensitive melt-cast explosive with good thermal safety. In order to study the response characteristics of RBOE explosives under slow cook-off conditions, this study carried out a numerical simulation study of slow cook-off for the ϕ35mm×116mm RBOE cylindrical warhead. According to the thermal decomposition characteristics of each component of the explosive, the thermal reaction model of the RBOE explosive was established. Numerical simulation of RBOE warhead cook-off was carried out at a heating rate of 1K/min; the internal temperature rise curve, phase change cloud diagram and ignition cloud diagram of the warhead were obtained, and the thermal response characteristics of the RBOE explosive were analyzed.
Applications and Future Developments of Flexible Organic Light-emitting Diode
Authors: Lei Buyu , Li Ruowei , Wu Jingyao , Yan Ran
Published: February 2022

With the rapid development of display technology, human beings have more and more stringent requirements for display products, e.g., their light weight, thinness, flexible performances, and versatility. Contemporarily, the flexible organic light-emitting diode (OLED) technology and its derived multi-layer structure tend to be wearable, light, and responsive in a short time. Although flexible OLED technology is popular, there are still many problems that needs to be addressed, e.g., new raw materials, rough flexible substrate, and low efficiency in workmanship, resulting in poor luminescence, rough and inflexible products. In this paper, a new type of flexible fiber display system is proposed by combining OLED with conductive optical fiber. This paper comprehensively introduces the mechanism, manufacturing technology and structure of this new type of flexible OLED. It covers various scopes like Internet information communication, real-time positioning, and medical assistance, etc. Despite some challenges and limitations, this product possesses a variety of advantages in terms of its convenience and flexibility, which makes the exploitation of a large range of applications probable. Therefore, it is highly expected that these promising prospects of development will stimulate the further progress in display fabrication, which helps to facilitate people’s lives in the future. These results shed light on the significance of developments of flexible OLED technology.
Research on the Progress of VOCs Adsorption by Biomass Nanocomposites
Authors: Wei Qing , Yang Jie , Tian Changan , Zhang Zhongmin , Zhang Xuan , Zhang Zhixin , Li Dong
Published: February 2022

The avoidance and control of the air is forthcoming, and its deterioration sources have a wide range of origin. Among them, the emission of VOCs is worthy of our attention. Its source is very wide, which seriously define the improvement of green chemical industry in our country. There are many types of VOCs, and when the concentration is too high, it will cause serious harm to the human body. Therefore, the avoidance and control of VOCs gas has become one of the current research tosspots. In this paper, several methods for alter VOCs gas are related, and it is found that adsorption is more economical and safer, and the core is the preparation of adsorbents. At the same time, the preparation of high-performance VOCs adsorbents based on TiO2 as the matrix and manganese-based as the raw material of biomass waste is also prospected.
A study on the capture of a droplet impact on a fiber
Authors: Gu Wenquan , Bai Zhishan
Published: February 2022

The phenomenon of droplets captured by fibers is ubiquitous and plays an important role in natural and industrial applications. This study focused on the impact process during a droplet impact on a fiber and established a physical model to describe this process. The critical velocity of capture above which the droplet might not be captured after the impact was deduced according to this model and the influence factors were investigated. These findings will be helpful to elucidate the mechanism of the impact between droplets and fibers and optimize the design of coalescence applications.
The effect of magnetic field on freezing point of water
Authors: Li YanMin , Lin HaiFei , Yang ZhenDong
Published: February 2022

Cold storage technology can realize energy storage and release according to demand and balance the power grid by “shifting peak and filling valley”. Ice cold storage system has the outstanding advantages of large cold storage density and simple system, and is the frontier direction of current cold storage technology research and application. However, there are some problems such as low phase transition temperature of cold storage medium and high energy consumption under cold storage condition. The research shows that magnetic field can increase the freezing point of water and aqueous solution by about 3.0-5.0K, which is beneficial to further increase the economic benefit and save energy in refrigeration condition based on the refrigeration demand.
The effects of temperature on surfactant solution: A molecules dynamics simulation
Authors: Feng Pang , Wang Linlin
Published: February 2022

We use molecules dynamics simulation to investigate the effects of temperature on surfactant solution, both the microcosmic and macroscopic performance of the surfactant solution. Results show that the increase of temperature has bidirectional influence on the capability of the surfactant solution. From the microscopic point of view, the thermophoresis of the free water molecules has arisen in the forward of the temperature, which causes the hydrogen bonding between molecules fracture and reconnection. And the micelles keep close to and detached from each other for these. From a macro perspective, viscosity will decrease with temperature. But when the temperature is about 392.15K, the viscosity-temperature curve will have a peak value. Combining the micro results and macro results of the molecules dynamics simulation, we can clearly draw a conclusion that the effects of temperature on the surfactant solution never are monotonic.
Poly-amino-based ionic liquids coupled with semi-coke for biogas upgrading
Authors: Chen Yang , Liu Mei , Qu Zhihui , Su Ziwei
Published: February 2022

Poly-amino-based ionic liquid (IL) [TETAH]+[BF4]- was mixed with sodium hydroxide solution for CO2 separation from biogas in a spray scrubber packed with modified semi-coke. A CO2 absorption capacity of 0.92mol was achieved when controlling the outlet CO2 concentration below 3 vol%. The porous structure of semi-coke contributed to improving CO2 absorption. Nitric acid oxidation and heat treatment could increase the specific surface area, enlarge the intrinsic pores and develop more micropores. Semi-coke firstly oxidized by nitric acid and then with heat treatment could not only exhibit higher specific surface area and more porous structure, but also show less degree of graphitization, which was suggested as possible to increase the reactivity to CO2. It was assumed that the absorption system in this research showed promising application in CO2 separation from biogas as well as waste treatment.
Density Functional Theory Calculation of Electronic Structure of Fe-N-C, Fe-O-C, Fe-P-C, Fe-S-C Single-atom Catalysts Systems
Authors: Ping JiangLu
Published: February 2022

Single atom catalysts (SACs) have emerged as a novel class of heterogeneous catalysts which exhibit superior catalytic performance in various reaction, CO oxidation, CO2 conversion, oxygen reduction reaction (ORR), etc. It is challenging to explore electronic structure and catalytic mechanics of SACs when the single metal atom is bonding with different dopants via experimental methods, which influence the catalytic efficiency directly. In this paper, Density Functional Theory (DFT) calculations, an ab initio simulation methods, have been carried out to investigate the properties of Fe-N-C, Fe-O-C, Fe-P-C, and Fe-S-C with oxo or hydroxyl group, four common SACs models. Geometry structure of Fe-N-C, Fe-O-C, Fe-P-C, Fe-S-C, and after each has bonded with oxo or hydroxyl group are studied. Formation energy of the Single Atom Catalyst (SAC), oxygen formation energy, and hydrogen atom transfer energy of the four SACs models are also calculated. In order to investigate the electronic structure of the four SACs, we examined the HOMO LUMO gap values for each system. In addition, we plotted the corresponding HOMO and LUMO orbitals of each SACs models and with oxo or hydroxyl group. Through analyzing the data, I anticipated that Fe-N-C model is the easiest to synthesis and the most stable among the four models. Our work discloses the microscopic property of SACs and provides valuable suggestions to experimental scientists.
Research and development of intelligent safety sensor integration devices for autonomous driving
Authors: Liu Shijie , Ma Zhaoyou , Guo Xinming , Zhuang Xucai , Chen Yonghong , Wu Jianqing , Xing Jianping
Published: February 2022

Grasping the status of vehicles timely and accurately is the key to avoid traffic accidents and collecting data from multi-sensors is significant for development of road-side intelligent sensor technology. In this paper, LiDAR (Light Detection and Ranging) and camera sensors are tested, and the sensor data can be processed and analyzed, and the display can be integrated. In this paper, a multi-sensor data acquisition integration device based on Raspberry Pi is proposed, which can realize the optimal processing of data and simultaneous acquisition display function. This method avoids the tedium of using an IPC and improves the efficiency of data acquisition and sensor integration.
Line average wind speed measurement system of roadway cross-section based on ultrasonic transit time Difference
Authors: li Tao
Published: February 2022

Aiming at the problems of low measurement accuracy, poor adaptability, and lack of real-time online measurement methods for roadway section average wind speed, combined with the characteristics of roadway section, based on the characteristics of time difference caused by ultrasonic propagation in forward and reverse flow medium, high-energy ultrasonic transmission and long-distance transit are realized by adopting automatic tracking correction technology of transmission frequency and high-pressure pulse drive technology. program-controlled filter amplification technology and peak hold technology are used to achieve high quality processing of received signals. Accurate measurement of ultrasonic transit time is realized by adopting AD high-speed sampling time positioning technology, floating threshold time difference measurement technology and circuit time delay self-determination measurement technology, and finally realizes the measurement of the average wind speed of the roadway cross-section line. The measurement system is tested on the gas flow standard device, and the measurement accuracy meets and exceeds the requirements of relevant standards. Compared with the current technical means for measuring cross-section wind speed in roadways, the system has the advantages of one-time measurement of average line wind speed, high accuracy, strong adaptability and real-time on-line monitoring.
Study on Counterweight Structure with Buffer Device
Authors: Feng Shuangchang , Liang Yanchun , Zhang Pengzhao , Chen Jie
Published: February 2022

At present, a buffer device is installed at the bottom of the elevator shaft to buffer the falling counterweight. When the elevator hits the buffer, the buffer absorbs or consumes the kinetic energy and potential energy of the elevator, so as to make the elevator or counterweight slow down safely until it stops. The corresponding counterweight is fixedly installed at the bottom of the elevator shaft. However, the counterweight installed at the bottom of the elevator shaft has certain disadvantages. In order to overcome the defects of the above existing technology, a counterweight structure with buffer device is studied in this paper. Compared with the prior art, the structure has the advantages of reducing construction time, high safety, simple structure, etc., and has universal popularization significance.
Online monitoring and early warning technology for the status of earth wire for overhead line
Authors: Feng Chao , Yang Rui , Cao Xianhui , Liu Weike , He Shuyuni , Ouyang Kejian , Jia Zhiwei , Xie Yi , Wang Jun
Published: February 2022

Overhead lines for wind power transmission in the southern region have the characteristics of large tower-line elevation, across thick ice areas, harsh natural environments, and difficult maintenance. Unpredictable line breakage accidents often occur, affecting the stability of the social power supply. This paper designs and introduces a technology based on intelligent perception technique for online monitoring of the earth wire, which can realize long-term real-time online monitoring of the state of the earth wire of overhead lines and solve the problem of line monitoring from wind power transmission and fault inspection and troubleshooting. Now the test and monitoring work of an overhead transmission line has been completed during the ice period, and the test results show that the technology has good monitoring performance.
Research on Condition Evaluation Algorithm of Oil-immersed Transformer Based on Naive Bayes
Authors: Yong Mingchao , Xue Jianmin , Wang Weijie , Wang Bangtian , Lv Lidong , Wang Qingshan , Shi Hongguang , Wu Bingxin , Chen Bogen
Published: February 2022

The improved three ratio method is a general algorithm for condition evaluation of oil immersed transformer. It has high accuracy in pre-test and laboratory analysis. However, the accuracy of DGA online monitoring data is not high, resulting in the decline of the positive judgment rate of transformer condition evaluation using the improved three ratio method, which is difficult to support the development requirements of transformer intelligence. To solve this problem, a DGA state evaluation method based on Naive Bayesian algorithm is proposed. The algorithm first performs preprocessing such as median filtering on the DGA online monitoring data to remove invalid data, then uses a triple composed of three conditional attributes to describe the characteristics of the DGA data, and finally calculates the a priori probability of training samples and the a posteriori probability of test samples by naive Bayesian algorithm for state evaluation. The verification of the algorithm on the measured data set shows that the accuracy of the algorithm is better than the improved three ratio method, and the algorithm is feasible and effective
S-type speed control curve based on the number of pulses
Authors: Zhang Zhizheng , Yu Yuanhua
Published: February 2022

The stepper motor is a kind of motor that converts electrical pulse signals into corresponding angular displacements or linear displacements, with high accuracy and easy control. According to the characteristics of stepper motor controlled by pulses, this paper designs an S-type speed control method based on the number of pulses, then tests and analyzes it in a motion system which controlled by STM32. The results show that: the change of the speed for the motion system is compared. It is stable and basically conforms to the designed quadratic function curve, and there is no out-of-step phenomenon in the test. While retaining the great stability and acceleration performance of S-type acceleration and deceleration, this control method greatly reduces the calculation difficulty. It is more suitable for microcontrollers and embedded control systems.
Robust Visual Place Recognition Method for Robot Facing Drastic Illumination Changes
Authors: Li Zhen , Zhou Lin , Lin Zeqin
Published: February 2022

The robustness of visual place recognition determines the accuracy of the SLAM to construct the environmental map. However, when the robot moves in the outdoor environment for a long time, it must face the challenge of drastic illumination changes (time shift, season or rain and fog weather factors), which leads to the robot’s ability to identify places is greatly restricted. This paper proposes a method for visual place recognition that is more robust to severe illumination changes. First, a generative adversarial network is introduced into visual SLAM to enhance the quality of candidate keyframes, and consistency of geographic locations corresponding to images before and after quality enhancement is evaluated, and then the image descriptor with illumination invariance is established for the robot's new observation image and keyframes of the map. Finally, the performance of the method in this paper is tested on the public dataset. The experimental results show that this method is conducive to improving the quality of environmental map nodes, and enables the robot to show a highly robust ability for visual place recognition in the face of severe illumination changes, which provides a powerful tool for robot to build an accurate environmental map.
An Ultra-low Power Off Chip Capacitor-less LDO With High Transient Response
Authors: Zhang Zihang , Xin Xiaoning , Chuai Rongyan , Han Meng
Published: February 2022

This paper presents a low-dropout linear regulator (LDO) with ultra-low power high transient response. This LDO adopts GAP-dynamic-bias circuit to achieve quiescent current as low as 242nA under 0-20mA load. A transient enhancement circuit based on window comparator is used to sense the output voltage change and further enhance the transient response. The circuit is designed and implemented using TSMC0.18um technology, and is verified by simulation using Spectre software. The simulation results show that when the load changes in the range of 10uA-20mA with a 1ns transition edge, the slowest overshoot and undershoot recovery times are only 2.36us and 2.15us. In the input voltage range of 2.5-3.6V, the linear regulation rate and load regulation rate are 0.479mV/V and 2.61nv/mA, respectively.
Measuring the orbital angular momentum mode of vortex beam based on phase matching sequence
Authors: Li Zhaohui , Xue Wenying
Published: February 2022

Measuring the orbital angular momentum(OAM) mode of vortex beams is of great significance in applications based on vortex beams.we propose a method of phase matching characteristics of vortex beams to measure the OAM mode. The method first use a high-speed spatial light modulator(SLM) to sequentially load a set of helical phase sequence images, so that the vortex beam is modulated by this SLM. Then obtain the modulated optical field through pinhole filtering, and then the synchronized tilt phase modulation is performed by the 4f system and high-speed SLM. When the OAM mode of vortex beam is opposite to the topological charge of helical phase image, that is, the incident vortex beam degenerates to the fundamental Gaussian mode beam,and through our optical system, the output plane obtained a indicating spot with the position related to the OAM mode. The Simulation and experimental results show that the method obtains a clear OAM mode indicating spot on the final output plane, which verifies the theoretical derivation.
An implantable loop antenna with Hilbert curve structures
Authors: Huang Jinfeng , Li Aoran
Published: February 2022

In this work, an implantable loop antenna with Hilbert curve structures is proposed. This antenna uses Hilbert curves to achieve extremely small electrical dimensions. In addition, we use magnesium instead of copper in the antenna structure, as it is healthier than copper. The proposed antenna covers a frequency band ranging from 765 to 1143 MHz (S11< -10 dB), a high efficiency (1.5%), and a maximum realized gain of -15.42 dBi. It is a promising candidate for implantable capsule antenna in medical devices.
Design of Intelligent Anti-suffocation System in Vehicle
Authors: Li ZHENG , Cao YUN , Jin ZHULE
Published: February 2022

With the progress of society, more and more families take cars as the main means of transportation. At the same time, due to the negligence of some parents, there are more and more suffocation accidents caused by children left in the car and adults resting in the car. At present, the research can only detect people who are moving around in the car, but not those who are resting in the car. At present, many systems are detecting and alerting, rather than directly solving the problem. The people left in the car with engine cut off and all the doors closed.The capacity of the car battery is very small, which requires the system operates with minimal power consumption. This problem is not considered in the current relevant research. To solve the above problems, this paper designs a system based on low power consumption dual microprocessor, combined with power management program, equipped with carbon dioxide sensor, temperature sensor and camera, which has low power consumption and can detect people resting and staying in the car at the same time. The system can effectively solve the shortcomings of the current research in view of the two situations of people resting and staying in the car at the same time.
AFESSD: Object Detector for Natural Gas Pipeline Construction Scene
Authors: Yang Zhen , Zheng Qinhao , Zhou Jie , Yin Zhijian
Published: February 2022

Object detection is a challenging task in computer vision, which aims to classify and locate objects. SSD (Single Shot MultiBox Detector) is one of the classical algorithms in the current object detection field, which uses multiple feature maps with different scales to detect all objects in an image. Based on SSD, in this paper, we propose an improved AFESSD for object detection in natural gas pipeline construction scene: Firstly, the attention mechanism module is introduced; Secondly, Feature Fusion Block and Feature Enhancement Block are designed to achieve high-to-low level feature information fusion and enhancement. Finally, we verify AFESSD on two object detection datasets of natural gas pipeline construction scene. Experimental results on the first dataset demonstrate that SSD and AFESSD achieve 81.35% and 83.13% mean average precision (mAP) respectively. On the second dataset, SSD and AFESSD achieve 50.55% and 50.99% mAP respectively. Therefore, AFESSD improves SSD’s object detection accuracy in natural gas pipeline construction scene.
Spine Image Segmentation Based on U-Net and Atrous spatial pyramid pooling
Authors: Yang Zhen , Chen Long , Fu Ting , Yin Zhijian , Yang Fan
Published: February 2022

In the past ten years, deep learning has achieved remarkable results in the area of natural image segmentation, and has gradually turned to the field of medical image segmentation. The precise segmentation of spine images can be used for early screening of spondylopathy, which is convenient for early detection and treatment of patients. Aiming at the segmentation of the spine image by the U-Net network, which structure will lead to large model calculation, network overfitting, image size, noise information and other issues. This paper introduces a new method based on spatial pyramid pooling module ASpp on U-Net network and applies the proposed network structure to the segmentation of the spine image. The model is first enhanced by the Spp module and Densenet data; secondly, the U-Net encoding and decoding structure is adopted, and the deep separable convolution is used. This method greatly reduces the complexity and computation of the model, and uses a rectangular convolution kernel to increase the computation of the model in a small amount. Based on the volume, the receptive field of the convolution operation is expanded; finally, in order to effectively enhance the segmentation area of the image, the SE-Net attention mechanism module is added to the lateral connection. The method proposed in this paper conducts ablation experiments on a public dataset of spine images and compares it with the U-Net network. The method proposed IOU in this paper can reach 72%, and the F1-score can reach 0.92. The comparison of the experimental results of spine medical image datasets shows that the method proposed in this paper can effectively improve the accuracy and accuracy of spine image segmentation.