bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-precision Measurements of Cosmic Curvature from Gravitational Wave and Cosmic Chronometer Observations
Authors: He Yuan , Pan Yu , Shi Dong-Ping , Li Jin , Cao Shuo , Cheng Wei 
Published: June 2022

Abstract
Although the spatial curvature has been measured with very high precision, it still suffers from the well-known cosmic curvature tension. In this paper, we use an improved method to determine the cosmic curvature, by using the simulated data of binary neutron star mergers observed by the second generation space-based DECi-hertz Interferometer Gravitational-wave Observatory (DECIGO). By applying the Hubble parameter observations of cosmic chronometers to the DECIGO standard sirens, we explore different possibilities of making measurements of the cosmic curvature referring to a distant past: one is to reconstruct the Hubble parameters through the Gaussian process without the influence of hypothetical models, and the other is deriving constraints on Ω
K
in the framework of the non-flat Λ cold dark matter model. It is shown that in the improved method DECIGO could provide a reliable and stringent constraint on the cosmic curvature (Ω
K
= −0.007 ± 0.016), while we could only expect the zero cosmic curvature to be established at the precision of ΔΩ
K
= 0.11 in the second model-dependent method. Therefore, our results indicate that in the framework of methodology proposed in this paper, the increasing number of well-measured standard sirens in DECIGO could significantly reduce the bias of estimations for cosmic curvature. Such a constraint is also comparable to the precision of Planck 2018 results with the newest cosmic microwave background (CMB) observations (ΔΩ
K
≈ 0.018), based on the concordance ΛCDM model.
Optimization of recess-free AlGaN/GaN Schottky barrier diode by TiN anode and current transport mechanism analysis
Authors: Wu Hao , Kang Xuanwu , Zheng Yingkui , Wei Ke , Zhang Lin , Liu Xinyu , Zhang Guoqi 
Published: June 2022

Abstract
In this work, the optimization of reverse leakage current (I
R) and turn-on voltage (V
T) in recess-free AlGaN/GaN Schottky barrier diodes (SBDs) was achieved by substituting the Ni/Au anode with TiN anode. To explain this phenomenon, the current transport mechanism was investigated by temperature-dependent current–voltage (I–V) characteristics. For forward bias, the current is dominated by the thermionic emission (TE) mechanisms for both devices. Besides, the presence of inhomogeneity of the Schottky barrier height (qφ
b) is proved by the linear relationship between qφ
b and ideality factor. For reverse bias, the current is dominated by two different mechanisms at high temperature and low temperature, respectively. At high temperatures, the Poole–Frenkel emission (PFE) induced by nitrogen-vacancy (V
N) is responsible for the high I
R in Ni/Au anode. For TiN anode, the I
R is dominated by the PFE from threading dislocation (TD), which can be attributed to the decrease of V
N due to the suppression of N diffusion at the interface of Schottky contact. At low temperatures, the I
R of both diodes is dominated by Fowler–Nordheim (FN) tunneling. However, the V
N donor enhances the electric field in the barrier layer, thus causing a higher I
R in Ni/Au anode than TiN anode, as confirmed by the modified FN model.
Research and Assumption on the Grid Structure of DC Distribution Network
Authors: Zhang Zhen , Zhao Zhan , Yang Xinke , Peng Chaode , Li Bingyu , Hu Yabo , Wang Yaqian , Li Haoran , Fan Zhonghua , Zhan Lvhao 
Published: June 2022

Abstract
Based on the typical structural characteristics of DC distribution network, this paper analyzes the application scenarios of different types of DC distribution systems based on the development planning and industrial layout of some cities. The differentiated demands, load types and user-side power consumption environment in different scenarios are studied. Determine the appropriate voltage level for various scenarios, the connected source terminal, energy storage terminal, and grounding method. On the premise of considering the user-side scenarios of typical DC applications, based on different power grid structures and operation modes, the optimal network topology relationship is studied, and a multi-scenario typical DC network topology architecture suitable for urban construction is constructed.
Low-carbon economic dispatch of power system based on mobile hydrogen storage
Authors: Li Panpan , Wang Rui , Xia Shiwei , Zhang Feng 
Published: June 2022

Abstract
To alleviate the global warming crisis, carbon reduction is an inevitable trend of sustainable development. The energy carrier with Hydrogen (H2) is considered to be one of the promising choices for realizing a low-carbon economy. With the increasing penetration level of wind power generation and for well-balancing wind generaion fluctuations, this paper proposes a low-carbon economic dispatch method for power systems based on mobile hydrogen storage(MHS). The wind power surplus during off-peak load periods is first utilized to generate green H2. Afterward, the green H2 is optimally transported to multiple hydrogen storage(HS) stations for generating power electricity by flexibly controlling the electrolysis(EL), methanation(ME), carbon capture(CCS) and H2 power generation processes, in such a way the wind power is coordinated with the hydrogen production, transport and utilization to reduce the total carbon emission and minimize the operation cost of power systems. Finally the proposed power system low-carbon economic dispatch model is verified by case studies.
Cause Analysis of Abnormal Condition in Partial Discharge Test of 220kV GIS
Authors: Yang Xuefei , Li Hongkun , Wang Kai , Yao Ribin , Zhou Yi 
Published: June 2022

Abstract
With the continuous development and construction of the power grid system, 220kV GIS equipment has been widely used in ultra-high voltage substations. Before leaving the factory, GIS equipment needs to be tested for lightning impact, partial discharge, etc. to check whether there are problems in the manufacturing, assembly and other links of the equipment. This paper analyzes a 220kV GIS when the partial discharge test (factory test) occurs when the partial discharge exceeds the standard. By using the directional elimination method, the equipment fault range is determined, and the fault structure is disassembled. Analysis, X-ray flaw detection results found that the insulation There are tiny bubbles in the base, indicating that the assembly workshop has problems of technical control or lack of cleanliness. At the same time, after the insulation base has been subjected to multiple lightning strikes, due to the cumulative effect, the equipment has exceeded the standard in the partial discharge test. Finally, through the analysis of the cause of the failure, the targeted rectification measures are put forward to improve the technical management and control level of the assembly workshop.
Influence of transformer leakage inductance on DC high current generator
Authors: Liu Z Y , Li Y F , Zhou J J , Liao Y , Zhao J C , Hu S L 
Published: June 2022

Abstract
The efficiency is affected by the parameters of components in the DC high current generator. The leakage inductance of the rectifier transformer will affect the output and filtering effect of the device and reduce the power quality of the public network. To improve the output and filtering effect of the DC high current generator, the 3-phase 6-pulsation rectifier bridge arm with the transformer T-type equivalent circuit is proposed. Through the topology model of each conduction state circuit of the semiconductor components, the expressions of load output, high-order harmonic content, and transformer leakage inductance are calculated. Then the actual generator is simulated in the MATLAB-Simulink module and variation law between the primary and secondary side leakage inductance and the output DC voltage, the total harmonic distortion(THD), and the fifth harmonic content rate is obtained. Finally, the output waveform is analyzed under the rated condition. The results show that the influence of transformer leakage inductance on output efficiency and high order harmonic filtering effect can be obtained by the proposed calculation method, and the simulation results verify the validity and correctness of the theoretical analysis.
Analysis of Cascading Failure Evolution Process of High Proportion New Energy Power System
Authors: Shen Zhengwei , Sun Huadong , Zhong Wuzhi , Wang Ansi , Zhao Bing , Xu Shiyun 
Published: June 2022

Abstract
The strong randomness of new energy, the weak anti-disturbance ability of power electronic equipment, and the interactive influence of multiple uncertainties in the source, network, and load side make the cascading failure evolution process of the high-proportion new energy power system more complicated. In order to reveal the evolution process of cascading failures, based on the defined key characteristic events, this paper divides the evolution process of cascading failures of high proportion new energy power system into the initial stage, development stage, and deterioration stage, and expounds its cascading situation in stages. Based on a DC project, cases with DC system was constructed, and the evolution process of cascading failures in high-proportion new energy power systems was simulated and analyzed.
Flame morphological characteristics of buoyant jet fires under different upward inclined nozzles
Authors: zhao Jinfei , Liu Jiahao , wang Jian 
Published: June 2022

Abstract
Flame morphological characteristics of buoyant jet fires from different upward inclined conditions have been experimentally studied in current work. The ethylene fueled jet flames were produced through a round nozzle with an inner diameter of 6mm. The results show that that both the flame horizontal projection length Lph
and the vertical flame height L0
increase with the increasing of heat release rate Q. For a given Q, the Lph
decreases with the increasing of upward inclined angle, while the L0
shows an inverse trend. The fitting results demonstrate that both the Lph
and L0
can be well correlated by the dimensionless heat release rate Q*.
Numerical simulation of gas-liquid two-phase flow on an attitude control system
Authors: Zhu Fengqi , Liu Wen , Li Xiaobei , Li Zhenjiang , Yan Tiantian 
Published: June 2022

Abstract
This paper introduced an attitude control system, which used saturated carbon dioxide as a medium. Through energy conversion, the system converted the pressure energy of gas-liquid mixed carbon dioxide into velocity energy and formed supersonic flow through the nozzle to generate thrust and torque. Compared with the compressed gas attitude control system, the carbon dioxide system had a better compelling specific impulse. With the continuous consumption of the medium, a large amount of liquid carbon dioxide was transformed into a gaseous state. Simultaneously, the pressure variation was slight, which was conducive to control. With a higher initial temperature, more liquid carbon dioxide was consumed, and the thrust was more significant under the same conditions of tank volume and carbon dioxide mass; meanwhile, the faster the temperature decreased.
A fault diagnosis method for power grid based on image feature extraction
Authors: Wu Qinge , Wan Guoliang , Song Zhichao , Li Penglei 
Published: June 2022

Abstract
In order to solve the problem that the traditional power grid fault diagnosis along the railway requires a lot of manpower and material resources, this paper proposes a fault diagnosis method on the power grid along the railway based on image feature extraction. A variable function family series method is designed to extract features of faults. For the fault image denoising, a convolution filter method is used, and the number of 2 denoising layers is selected. At the same time, extracting the decomposition coefficient features and energy features of power grid image faults. Moreover, the matching diagnosis method is given. The fault is finally identified based on the similarity. To compare with the existing fault diagnosis methods, the correct diagnosis rate of the fault diagnosis method proposed is more than 92%. From experimental comparison results, this diagnosis effect not only has higher precision, stronger anti-interference ability, but also has faster diagnosis speed.
Design of multi-robot collaborative navigation and control system based on ROS and laser SLAM
Authors: Zheng Zhuoling , Gong HaoYu , Duan RuoBing , Qiu XinYu , Zou Jiajun 
Published: June 2022

Abstract
Through in-depth research in the current robot field, a design scheme of cooperative navigation and control system for multiple robots based on ROS and laser SLAM is proposed. Compared with a single robot, multi-robot cooperation can improve the operation range and efficiency, and is suitable for more diversified scenarios. The system design includes multi-machine mapping, multi-machine global and local path planning, multi-machine navigation, real-time obstacle avoidance, multi-machine dynamic task assignment. Through the centralized control structure, the robot collects the lidar data in real time to build the map in real time and realizes the integration of multi-machine map building. Then, the path planning algorithm is called to plan the path. Combined with the dynamic task allocation algorithm, the efficiency of multi-robot cooperative operation is maximized and the execution experience is provided for the implementation of other similar projects.
Object Detection and Ranging System Based on Binocular Vision
Authors: Guo Haizhou , Li Zili 
Published: June 2022

Abstract
For the Census transform stereo matching algorithm is susceptible to noise leading to mis-matching, a stereo matching algorithm based on the improved Census transform is proposed, which improves the Census transform reference value selection and incorporates the image gradient information to form the initial cost. Train the lightweight network model NanoDet to quickly detect and obtain the object position, and combine the object disparity and camera parameters to obtain the distance of the object, and transplant the system to an embedded device for practicality verification. After analyzing and verifying the experimental data, it shows that the anti-noise capability of the improved algorithm is significantly improved, and the proposed method can quickly complete the detection and ranging tasks on embedded devices with high reliability and practicality.
Research on Robust Detection System of Vehicle Attitude Fusion Features Based on Multi-Sensor Fusion
Authors: Hu Wen , Kang Longyun , Yu Zongguang 
Published: June 2022

Abstract
With the rapid development of artificial intelligence technology, the field technology of intelligent vehicles is becoming more and more mature. In order to solve the problem of difficult to extract the positional information due to the vestigial point cloud of moving vehicles acquired by LiDAR in complex traffic scenes, a real-time positional estimation method for dynamic targets based on point normal vector features of multi-sensing fusion is proposed. The least-squares fitting algorithm is used to solve the point normal vectors on the target surface, the principal component analysis is used to solve the number of cluster centers of the point normal vectors by adaptive clustering algorithm on the high-dimensional data, the clustering point fitting plane is obtained, and the mutually perpendicular planes representing the point normal vectors are selected as the X and Y axes of the coordinate system to which the target to be measured belongs, and the multi-target sensing fusion feature technology is combined with the sensing features of radar laser and vision, and the point cloud position calculation is completed. The experimental results show that the method can estimate the posture parameters of the moving vehicle in real time and exhibit good robustness.
The realization of a broadband light absorber via the synergistic effect of graphene and silicon nanostructures
Authors: Fan Jiakang 
Published: June 2022

Abstract
Due to the increasing demand for clean energy, it becomes more and more necessary to find out more efficient ways to generate clean energy. Because of this, the light conversion efficiency of different materials has been largely studied. The purpose of the study is to investigate how the silicon pyramidal nanostructures and graphene layer affect the light-absorbing performance of materials and achieve a broadband light absorber. Simulations of four experimental groups, including both with nanostructure and graphene, with nanostructure and without graphene, without nanostructure and with graphene, both without nanostructure and graphene, are done to obtain and compare the data through the method of finite difference time domain (FDTD). By analyzing the simulation results, it is found that the silicon pyramidal structures can improve the light absorption within the range of visible light. Moreover, the presence of graphene layers can improve the light absorption within the range of near-infrared to infrared light. The number of layers can also have effects on light absorption.
Laser metal deposition of Ta-10W alloy based on annular laser cladding with internal wire feeding
Authors: Cao Jiazhao , Kong Lingchao , Chen Yongxiong , Zhang Zhibin , Liang Xiubing , Xia Ming , Sun Bo 
Published: June 2022

Abstract
Laser metal deposition is a new type of laser forming technology with the advantages of small heat affected zone, low dilution rate and high bonding strength. Ta-10W is a high temperature refractory material, which often used in aerospace fields. However, the high melting point and thermal conductivity causes Ta-10W to be prone to cracks collapse during processing and forming. Annular laser cladding provides a feasible way to solve the contradiction between high temperature service performance and processing performance of Ta-10W due to its high energy density, freedom of direction and nearly 100% material utilization. In this paper, Ta-10W cladding layers without cracks and pores were successfully deposited on the Nb substrate based on the wire-annular laser cladding technology. The hardness of the cladding layer is 4 times that of the Nb substrate and the dilution rate is extremely low. The Ta-10W wire must be in the center of the annular laser, otherwise the cladding may fail to form. It is found that the larger the wire feeding speed results in the smaller the aspect ratio; while the larger scanning speed, defocus distance and laser power result in the larger aspect ratio. This work opens up a new path for the fabrication of refractory metals, which is significant for processing high temperature materials.
Study on Component Stability and Curing Process of Polyurethane Reinforcement Material
Authors: Song Weiguo , Liu Xiangyuan , Dong Hao 
Published: June 2022

Abstract
Polyurethane (PU) reinforcement material was prepared by polymeric MDI, water glass, polyether polyol, dioctyl phthalate, and the catalyst as the raw materials. The stability of the component A and the curing process of PU reinforcement material were studied by viscosity analysis, compression test, scanning electron microscopy (SEM) and transmission/diffuse reflectance infrared spectroscopy (FTIR/DRIFTS). The results show that the component A of PU reinforcement material has good stability, and the compressive strength of PU reinforcing material prepared by placing components A and B for 28 days is still above 50 MPa. Moreover, during the curing process of PU reinforcement material, the increase of the crosslinking density of the organic phase and the compressive strength of the composites are promoted by the reaction between isocyanate groups and water from the inorganic phase. At the same time, the resulting Na2CO3 in the inorganic phase is transported by water and enriches in the interphase region to form needle-like crystals.
Preparation of ZnO-BiOCl Composite and its Visible-light Photocatalytic Degradation of RhB
Authors: Hong Jin , Gang Siqi , Wang Fei , Lu Guang 
Published: June 2022

Abstract
The ZnO-BiOCl composite were prepared by a soft chemical method. And crystalline phase, morphology, optical property and photocatalytic efficiency of ZnO-BiOCl compound semiconductors were studied by XRD, SEM, DRS and RhB photodegradation under visible-light irradiation. The results showed that ZnO-BiOCl compound semiconductor was significantly more active than ZnO or BiOCl, since ZnO-BiOCl compound semiconductor may facilitate the transfer of charge carriers and retard the e--h+ recombination. Moreover, the photocatalytic degradation of RhB over ZnO-BiOCl composite sample is the highest, which is also caused by the combination of the photocatalytic performance of ZnO and the photosensitization performance of BiOCl.
Simulation analysis of thermal stress/strain of single fiber and multi-fiber composites caused by elevated environment temperature
Authors: LIN Mei , ZHANG Tiejun , FENG Yu , LIU Songjing , ZHOU Zhangwen 
Published: June 2022

Abstract
To study thermal expansion problem caused by environment temperature changes during service life, single and multi-fiber finite element models were established to investigate thermal stress/strain of composite. Single fiber model was shown that longitudinal thermal stress/strain distribution of fiber or matrix is uniform, but stress/strain distribution of transverse direction was more complex than longitudinal direction. Furthermore, longitudinal and transverse thermal stress at composite free end zone is higher than that of in inner zone. Then the influence of different fiber arrangement on thermal stress was discussed by finite element model of multi-fiber composite. It indicated that damage initiation would emerge at somewhere randomly in fiber regular arrangement model. But in fiber random arrangement model, initial damage will concentrate on interface of fiber-rich zone. In addition, thermal expansion model in this paper may provide simple and practical method to calculate thermal stress/strain, so as to prevent matrix cracking or interface debonding due to thermal stress concentration.
Analysis of the vibro-acoustic behaviours of underwater reinforced rectangular plates
Authors: Ye Jiazhi , Sun Yao 
Published: June 2022

Abstract
In this paper, the vibration and sound radiation of underwater stiffened plates with arbitrary boundary condition have been studied. The vibration of the structure is described by an improved Fourier series, the water-load acts on the structure is solved by Rayleigh integral, and the dynamic response is solved by an energy method. The results show that the increase of plate thickness and boundary constraint can enhance the vibration and sound transformation ability of underwater rectangular plate, and the mechanism is that the increase of vibration mode frequency increases the radiation efficiency of the dominant acoustic radiation mode. By analyzing the effect of stiffening mode and quantity on acoustic radiation, it can be seen that for the plate (1,1) mode, the longitudinal stiffening mode has the lowest vibration energy conversion rate, and the main mechanism is that the dominant acoustic radiation mode has the lowest radiation efficiency, while the transverse stiffening mode has the highest radiation efficiency. In addition, when the reinforcement is distributed, the natural frequency and the radiation efficiency of the corresponding dominant acoustic radiation modes of the stiffeners are reduced, the vibration- acoustic conversion of the plate showed a decreasing trend.