bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.
Large variations in global irrigation withdrawals caused by uncertain irrigation efficiencies
Authors: Puy Arnald , Lankford Bruce , Meier Jonas , van der Kooij Saskia , Saltelli Andrea 
Published: February 2022

Abstract
An assessment of the human impact on the global water cycle requires estimating the volume of water withdrawn for irrigated agriculture. A key parameter in this calculation is the irrigation efficiency, which corrects for the fraction of water lost between irrigation withdrawals and the crop due to management, distribution or conveyance losses. Here we show that the irrigation efficiency used in global irrigation models is flawed for it overlooks key ambiguities in partial efficiencies, irrigation technologies, the definition of ‘large-scale’ irrigated areas or managerial factors. Once accounted for, these uncertainties can make irrigation withdrawal estimates fluctuate by more than one order of magnitude at the country level. Such variability is larger and leads to more extreme values than that caused by the uncertainties related with climate change. Our results highlight the need to embrace deep uncertainties in irrigation efficiency to prevent the design of shortsighted policies at the river basin-water-agricultural interface.
China’s power transformation may drastically change employment patterns in the power sector and its upstream supply chains
Authors: Zhou Sili , Chen Bin , Wei Wendong , Liu Zhaohui , Song Song , Feng Kuishuang , Li Jiashuo 
Published: February 2022

Abstract
China’s power sector, as the major CO2 emitter, has experienced significant restructuring that has had profound impacts on employment in both power and its upstream sectors. Combining input–output and structural path analysis, we quantified the direct and indirect impacts of power transformation on employment in China between 2012 and 2017. Direct employment in the power generation sector witnessed a net growth of 0.12 million, while over 10 times that number of jobs (1.40 million) have been lost in the upstream sectors, mainly in coal mining and washing, finance, oil and gas extraction and transportation. Among the top 10 critical paths, the share of employment driven by solar and wind power increased to 12.31% in 2017, more than nine times that in 2012. Furthermore, three scenarios have been set up to evaluate the employment patterns in 2030 and 2050. Under the 1.5 °C scenario, projection shows that the power sector could support over 5 million jobs in 2050, with more than 80% of these being related to renewable energy. Policy suggestions for a just transition, such as resettlement of laid-off workers and job transfer in upstream industries, are comprehensively discussed.
Statistics of the maximum and the convex hull of a Brownian motion in confined geometries
Authors: De Bruyne Benjamin , Bénichou Olivier , Majumdar Satya N , Schehr Grégory 
Published: February 2022

Abstract
We consider a Brownian particle with diffusion coefficient D in a d-dimensional ball of radius R with reflecting boundaries. We study the maximum M

x
(t) of the trajectory of the particle along the x-direction at time t. In the long time limit, the maximum converges to the radius of the ball M

x
(t) → R for t → ∞. We investigate how this limit is approached and obtain an exact analytical expression for the distribution of the fluctuations Δ(t) = [R − M

x
(t)]/R in the limit of large t in all dimensions. We find that the distribution of Δ(t) exhibits a rich variety of behaviors depending on the dimension d. These results are obtained by establishing a connection between this problem and the narrow escape time problem. We apply our results in d = 2 to study the convex hull of the trajectory of the particle in a disk of radius R with reflecting boundaries. We find that the mean perimeter ⟨L(t)⟩ of the convex hull exhibits a slow convergence towards the perimeter of the circle 2πR with a stretched exponential decay

2
π
R
−

⟨

L

(

t

)

⟩

∝

R

(

D
t

)

1
/
4

e

−
2

2
D
t

/
R

. Finally, we generalise our results to other confining geometries, such as the ellipse with reflecting boundaries. Our results are corroborated by thorough numerical simulations.
Justification of the Technology of Construction of Mine Shafts for the Conditions of the Maly Kuibas Deposit
Authors: Kalmykov V N , Zubkov A A , Volkov P V , Kulsaitov R V 
Published: February 2022

Abstract
The technology of construction of mine shafts for the conditions of the Maly Kuibas deposit is presented. The dimensions of the cross-section of the mine shafts are selected. The parameters of drilling and blasting operations have been calculated. Selected equipment for drilling holes in the borehole and loading the blasted rock mass. The lifting parameters were determined, the ropes were selected, and the lifting machines were selected. The technological schemes and methods of construction of shafts are considered. Designs of mine headframes are proposed.
Assessment of the Possibility of Using ROV in the Mode of Joint Traffic with the Support Vessel
Authors: Kostenko V V , Mokeeva I G 
Published: February 2022

Abstract
The correspondence of the characteristics of the propulsion and steering complex (PSC) to the values required to compensate for the response of the communication cable determines the efficiency of using tethered underwater vehicles. The report assesses the requirements for the thrust characteristics of the PSC, which ensures the maneuvering of the vehicle relative to the carrier or garage in the mode of movement of the complex along an extended bottom object. The assessment is based on the results of calculating the tension of the communication cable in the stream, due to the joint movement of the tethered system “carrier-garage-vehicle”. This tension, together with the hydrodynamic resistance of the apparatus body, determine the requirements for the thrust characteristics of the PSC, as well as for the power supply system of the complex as a whole. An algorithm is proposed for calculating the tension of the communication cable between the vehicle and carrier in a stationary flow, based on the equation of a chain line and numerical integration of the equations of an inextensible flexible thread. An example of using the proposed methodology for calculating the variants of a tethered system is given.