bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of Microphone Coupling and Zero-Point Calibration Model for Non-Resonant Photoacoustic Spectroscopy
Authors: Sun Liqiang , Cui Fangxiao , Wang Anjing 
Published: February 2024

Abstract
Dissolved Gas Analysis (DGA) of transformer insulation oil is an effective method for monitoring transformer operating conditions and diagnosing faults. Photoacoustic spectroscopy (PAS) is widely employed for online dissolved gas analysis in transformer oil. The positioning of the pressure equalization hole within the sound field significantly impacts the microphone’s sensitivity when coupled with the photoacoustic cell in non-resonant photoacoustic spectroscopy. The static temperature and humidity characteristics inside the photoacoustic cell also have a notable influence on the microphone’s output signal. Consequently, an analysis is performed to explore the relationship between the sensitivity of the photoacoustic spectrometer and temperature/humidity, leading to the optimization of the system configuration based on the microphone parameters. Moreover, the photoacoustic zero-point signal is influenced by the temperature and humidity levels within the photoacoustic cell. To address this problem, air mixtures at different humilities are measured, resulting in the establishment of a zero-point model for the background signal in Photoacoustic Spectroscopy (PAS). Subsequently, the experimental detection of acetylene under various humidity mixtures is conducted, successfully extracting effective signals for the measurement of 5 ppm acetylene gas. These results serve as evidence showcasing the efficacy of both the proposed structural optimization and zero-point model put forth in this study.
Intelligent residual film recovery machine monitoring and control system
Authors: Wang Zifan , Jian Jianming , Tang Xiuying , Niu Changhe , Wang Meng , Wu Kai , Tian Ziyang 
Published: February 2024

Abstract
Domestic residue recovery machines in China still follow the traditional towed mechanical model, lacking automation and intelligent features. Under the key R&D project of Xinjiang Autonomous Region, our team has developed integrated intelligent agricultural machinery for cotton straw crushing and residue recovery. This research covers the monitoring and control system, including PLC control and communication, working parameter monitoring and adjustment, algorithmic control of electro-hydraulic actuators, and human-machine interface display. Compared to traditional models, this machine replaces the conventional chain-driven mechanical structure and diesel tractor traction power with a fully hydraulic integrated suspension drive and power system. Sensors, PLC, and a touch screen are utilized for real-time monitoring and display of parameters. Hardware components like electromagnetic switch valves, electro-hydraulic proportional valves, hydraulic cylinders, and software elements such as PLC programs and intelligent control algorithms are employed for electro-hydraulic switching and proportional control of certain working parameters and mechanisms. All parameter information is consolidated in the PLC host and expansion modules and displayed and controlled on the human-machine interface. The system was installed on the first-generation machine for indoor testing, revealing that the monitoring and control system used on the first-generation machine achieves parameter detection and adjustment of the actuating mechanisms. It incorporates more advanced functions compared to traditional residue recovery machines. However, there is still ample room for improvement in the overall intelligence of the machine. The control system’s structure requires adjustment, and certain functionalities of the overall mechanical structure and working components need optimization or upgrading. Detailed enhancements to the entire system will be made in the next-generation machine.
Study on electromagnetic dosimetry of the power cable in electric vehicle
Authors: Dong Xuwei , Gao Yunshan 
Published: February 2024

Abstract
To calculate the induced fields in the human body of the driver in an electric vehicle, the power cables of the electric vehicle are taken as the electromagnetic exposure source. The finite elements method is used to construct the electromagnetic environment model, which consists of the vehicle body, the power cables, and the driver body. The maximal values of the magnetic flux density inside the driver’s trunk and head are 4.63 μT and 0.12 μT, respectively. The maximal induced electric field intensity values are 670 mV/m and 99.7 mV/m, respectively. All values are below the safety limits of the ICNIRP. The results show that the electromagnetic environment induced by the power cables is safe for the driver. The study could provide a reference for improving electromagnetic exposure standards for electric vehicles.
Development of new pocket distribution network inspection equipment
Authors: Lin Lin , Su Weiwei , Wang Qinyang , Ge Qin 
Published: February 2024

Abstract
This paper aims to explore a new intelligent inspection mode of pocket distribution network equipment, which realizes rapid and comprehensive inspection and inspection by using terminal +N intelligent sensors and partial discharge detection and infrared temperature measurement technology as the core. First, this paper introduces the background and motivation of the new mode, and emphasizes the limitations of the existing traditional inspection methods and the problems that need to be improved. Then, the design and manufacture of pocket devices are described in detail, including key aspects such as sensor integration, portability and user-friendliness. Finally, the paper summarizes the research results and emphasizes the potential benefits and future research directions of this new intelligent inspection model.
Research and application of relay protection setting calculation for SFC system of pumped storage power station
Authors: Shi Fangfang , Yang Chao , Zhang Zehui , Zhang Zhaohui , Xu Kezheng 
Published: February 2024

Abstract
Pumped storage is a key way to meet the regulatory needs of the power system. Currently, SFC starting has become the main starting method for large pumped storage power plants. This article introduces the typical structure and operation principle of SFC in pumped storage power plants. Based on existing guidelines, the relay protection configuration and setting principles of the SFC system in pumped storage power plants are elaborated. Starting from engineering practice, a relay protection setting calculation scheme for SFC input and output transformers is proposed and put into operation on site, ensuring the reliable and stable operation of the SFC system in pumped storage power plants.
Grasping characteristics of SMA bionic flexible dexterous hand
Authors: Song Hailong , Ren Tingting , Ni Yingqian , Wen Shanlin , Wang Cai , Zhang Wenbin 
Published: February 2024

Abstract
In order to achieve the mechanical performance of grasping objects with SMA bionic flexible hands, a tendon finite element modeling method is proposed in this article to meet the mechanical requirements of the tendon being subjected to only axial forces and not radial forces. By using finite element dynamic simulation and experimental testing methods, the mechanical characteristics of the SMA bionic hands during the grasping process are analyzed and validated. A finite element dynamic simulation model of the SMA bionic hand grasping process is established to study the overall stress characteristics and contact forces of each phalanx, revealing the grasping characteristics of the bionic hand under SMA driving conditions. By creating a physical prototype of the SMA bionic hand, grasping of different objects is achieved. The results show that the stress in the grasping state of the bionic hand does not exceed 21 MPa, the sum of contact forces is 22 N, the theoretical grasping force is 13 N, and the prototype can grasp objects within a diameter range of 70 mm.
Energy management strategy of urban rail hybrid energy storage system based on fuzzy logic system
Authors: Meng Qinglu , Wang Siming 
Published: February 2024

Abstract
Energy management is an important link in the effective functioning of hybrid energy storage systems (HESS) within urban rail trains. This factor significantly impacts the operational stability and economic efficiency of urban rail systems. Safety issues arise from DC bus voltage fluctuations due to varying train conditions. To address these issues, this paper proposes an energy management strategy for the urban rail HESS, which builds upon a traditional double closed-loop control strategy. This strategy incorporates a fuzzy logic system to regulate power distribution parameters and discharge thresholds dynamically. Real-time monitoring of the state of charge (SOC) of the energy storage device informs the decision-making process, utilizing a fuzzy inference system to effectively regulate power and energy distribution in response to the distinct characteristics of batteries and super-capacitors. This approach aims to mitigate power fluctuations within the traction network. To validate the effectiveness of the proposed energy management strategy, the study conducts a comprehensive simulation experiment using MATLAB/Simulink. The simulation results confirm the efficacy of the proposed strategy, highlighting its potential to enhance the stability and overall performance of urban rail train operations.
Visualization of the vortex structure formation of a long-lived afterglow arising in a symmetrical pulsed discharge
Authors: Kudryavtsev Anatoly A. , Yuan Chengxun , Zhao Shixin , Astafiev Alexander M. , Shabanov Gennady D. , Chirtsov Alexander S. 
Published: February 2024

Abstract
A visualization of the emerging toroidal vortex in the long-lived afterglow of a high-current symmetrical pulse discharge with an electrolyte anode has been carried out. The visualization of the emerging vortex flow was carried out using the laser knife method using a powerful 10 W laser, which formed a flat divergent beam, which was reflected from dust particles in the atmosphere. For greater contrast, water vapor was let in into the region of the discharge and the emerging afterglow, which moved synchronously with the emerging afterglow vortex. The laser beam reflected from small water vapor droplets made it possible to visualize the gas flow, which was then filmed with a high-speed video camera. The presented data clearly show that the emerging afterglows are able to retain their volume for a long time precisely due to the formation of a vortex structure.
Investigation of lift enhancement through circulation control for distributed propulsion
Authors: Guo Longkai , Zhao Qing , Sun Yunzheng , Zhu Yaowu , Su Shijia , Da Xingya 
Published: February 2024

Abstract
To meet the design requirements for high lift airfoils, an optimization design platform was established using the SNOPT (Sparse Nonlinear Optimizer) method. Two airfoils were designed to achieve both low-speed takeoff/landing and high-speed cruise performance. A comparison between the self-designed airfoils and mature airfoils was carried out at different operating conditions, and the airfoil that met the target requirements was selected. Subsequently, an integrated design of ducted-fan/wing was conducted to study the effect of integrated constraints on the lift augmentation of the wing with the action of the propeller. The results showed that under the integrated layout, the ducted-fan significantly changed the flow velocity field from the front of the inlet and the tail jet, which to some extent changed the upper surface circulation of the wing. Compared with the pure wing, the maximum lift increase was up to 332 %.
Deposition of vertical carbon nanostructures by microwave plasma source on nickel and alumina
Authors: Marinov S , Ivanov I , Popov G , Abrashev M , Kiss’ovski Zh 
Published: February 2024

Abstract
Vertical carbon nanostructures on metal and ceramic substrates are deposited successfully using planar microwave plasma source at frequency of 2.45 GHz. The PECVD (Plasma Enhanced Chemical Vapor Deposition) with microwave surface wave discharge is applied because it produces a dense plasma providing efficient decomposition of the methane and creation of a large number of reactive particles which results in lower substrate temperature for graphene deposition compared to CVD method. Optimization of the gas mixture of H2, Ar and CH4, and the gas pressure in the chamber results in a homogeneous graphene structures deposition on the substrates of Ni-foil, Ni-foam and alumina ceramics at substrate temperatures ∼600 °C. The plasma parameters of surface wave discharge such as gas temperature, electron temperature and density are obtained by measuring OH-band and Ar-lines using optical emission spectroscopy. The morphology of the vertical carbon structures is obtained using SEM analysis and the characteristics of the graphene layers were determined by Raman spectroscopy.
Effect of the beam oscillation on the structure and mechanical properties of electron beam welded joints of Ti6Al4V and Al6082-T6 alloys
Authors: Kaisheva D , Dunchev V , Anchev A , Stoyanov B , Ormanova M , Atanasova M , Todorov V 
Published: February 2024

Abstract
The results of electron beam welding of Ti6Al4V and Al6082-T6 alloys are presented. The influence of electron-beam scanning geometry on the structure and mechanical properties of the welded joint is studied. Two kinds of samples were investigated – the first specimen was welded without beam oscillation and the second one was obtained using an oscillating electron beam following a circular trajectory of scanning with an oscillation radius of 0.2 mm. X-ray diffraction (XRD) method was used for the determination of the phase composition of the welded joints. The microstructure of the welded joints was studied using Scanning electron microscopy (SEM). Energy-dispersive X-ray spectroscopy (EDX) was applied for the chemical composition investigation. Tensile experiments and microhardness measurements were performed to study the mechanical properties of the welded joints. The sample welded without the application of an oscillating beam showed higher values for the yield strength and tensile strength. The values measured for the microhardness within the welded seam are about 450 HV0.05 in both cases. However, the application of a beam oscillation leads to a significant increase in the micro-hardness of the heat affected zone at the Ti-based alloy. The measured values reached 627 HV0.05.
Spectroscopic ellipsometry modelling of thin AuSn films and nanostructures as plasmonics materials
Authors: Todorov R , Hristova-Vasileva T , Milushev G , Milanov E 
Published: February 2024

Abstract
A considerable interest in nanostructured thin films from intermetallic compounds of noble metals (Ag and Au) and post-transition metals is raised due to their unique plasmonic properties, which makes them potential materials for application in photonics, catalysis and biosensing systems. In this work the possibility for deposition of polycrystalline AuSn thin films was investigated, as thin films with the same composition and different thicknesses (10-100 nm) were obtained by co-depositing of Au and Sn metals. The chemical composition was determined by X-ray microanalysis. The X-ray diffraction patterns indicated formation of the intermetallic compound AuSn in the thin films. The complex permittivity ε = ε′ - i.ε″ of the thin AuSn films as function of the thickness was investigated by spectroscopic ellipsometry. The possibility for application of nanostructures from the AuSn intermetallic compound as suitable substrates for the needs of surface-enhanced Raman and fluorescence spectroscopy in the spectral interval 2.8 - 4.7 eV was analysed.
Investigation of properties of novel multilayer Cr/CrN/CrTiN/CrTiAlN hard coating with four bilayers
Authors: Chitanov V , Zlatareva E , Kolchev S , Cholakova T , Kolaklieva L , Kakanakov R , Pashinski C 
Published: February 2024

Abstract
A novel multilayer Cr/CrN/CrTiN/CrTiAlN hard coating with four bilayers was developed by reactive closed field unbalanced magnetron sputtering (CFUBMS). The substrate temperature was kept in the range of 170 °C to 200 °C. The reactive gas flow was controlled by Optical Emission Monitoring. A thickness of 1.8 μm was determined using a calotester. The morphology and chemical composition were studied by electron microscopy (SEM and EDS). Nanohardness of 34.1 GPa and a modulus of elasticity of 386 GPa were determined using the nanoindentation technique. The scratch test against a diamond Rockwell indenter did not show features indicating poor adhesion. The reciprocating wear test revealed strong resistance to wear, and a coefficient of friction of 0.19 was determined. The developed multilayered hard coating showed optimal mechanical properties for industrial applications on instruments of low-temperature materials.
Structure and mechanical properties of TiCN-ZrCN multilayer coatings
Authors: Kolchev St , Cholakova T , Kolaklieva L , Kakanakov R , Bahchedjiev Ch , Chitanov V , Zlatareva E 
Published: February 2024

Abstract
The present study is focused on the design, deposition and characterization of nanoscale multilayer TiCN/ZrCN coatings obtained by cathodic-arc PVD technique. The multilayer coatings with the bilayer period’s thickness of 12 nm, 20 nm and 32 nm were deposited on stainless steel and high-speed steel substrates at temperature of 320°C in a mixture of N2 and CH4 gases. Scanning electron microscopy equipped with energy dispersive x-ray spectroscopy, was employed to investigate the top surface morphology, cross-sectional morphology, bilayer thickness and structure of the coatings. Mechanical properties were investigated via Calotester, Nanoindentation tester, Scratch tester and Tribometer. The SEM/EDS cross-sectional analysis revealed a columnar morphology and well expressed multi-layered periodic structure. All the multilayer samples demonstrated an increase in hardness and well fracture resistance ability in comparison to TiCN and ZrCN monolayer coatings. The highest nanohardness of 41GPa and better wear resistance for the coatings with bilayer period of 12 nm was determined. The results of the study show that a reduction in the thickness of the individual sub-layers has a significant impact on the mechanical properties of the coatings.
Characterization of program and erase speed of memory capacitors with nanolaminated HfO2/Al2O3 stacks for application in non-volatile memories
Authors: Spassov D , Paskaleva A , Ivanov Tz , Stanchev T 
Published: February 2024

Abstract
The programming and erase performance of atomic layer deposited HfO2/Al2O3 memory stacks is investigated depending on the thickness of the tunnel oxide and the annealing of the structures. The as-grown stacks require applying of voltage pulses with duration of about 10-3 s for a measurable electron trapping (programming). The time dependence of the electron trapping process is quite sharp initially - the increase of the charging time from 4×10-4 s to 4×10-3 s provides more than 80% of the saturation value of the trapped charge obtained at durations above 1 s. The annealing increases the time needed for the onset of the electron trapping. For the chosen voltage amplitudes the programming characteristics does not depend on the tunnel oxide thickness. The electron detrapping (erase) is observed even at durations of ~10-7 s, but with a low efficiency. The erase characteristics is more gradual then the program one, and shows some dependence on tunnel oxide and annealing. The complete erase is achieved for times comparable to those for programming the cell. Erase pulses with duration > 10-2 s results to accumulation of positive charge in the capacitors.
Investigation on the fine structure of the B
1∏ − c
3∑+ complex in KRb
Authors: Stoyanov V , Pashov A 
Published: February 2024

Abstract
The fine structure of the transitions in the (X, υ″ = 0 → (B, c), υ′ = 2) band system in K85Rb is studied by using selective Doppler-free spectroscopy techniques. Energy shifts of the perturbed levels due to spin-spin, spin-rotation and spin-orbit interactions were analyzed and modeled within the effective Hamiltonian approach. Molecular and coupling constants were determined, which successfully model the experimental observations.
A compact frequency-selective absorber with optical transparency
Authors: Deng Kewen , Li Feipeng , Wang Xingyu , Feng Jiqiang , Xu Chen 
Published: February 2024

Abstract
This article proposes a new method for designing an optical transparent frequency-selective surface absorber using indium tin oxide (ITO) conductive film with different sheet resistances. This novel optical transparent frequency-selective absorber exhibits excellent optical transparency, ensuring a visible light transmittance exceeding 76%. Simultaneously, it exhibits broadband absorption characteristics covering the entire X-Ku band, with an absorption rate exceeding 90%. Due to the simplicity of the design, the overall structure is easily processable, and the desired product can be rapidly fabricated using laser etching equipment without adding any lumped elements in the design. Simulation and experimental results indicate that the S11–10 dB frequency range of the frequency-selective absorber is 7.7–18.4 GHz, with a transmission frequency range below −3 dB between 26.7–29.4 GHz. The findings suggest that this structure holds potential applications in microwave stealth design requiring optical transparency and high-throughput satellite communication scenarios.
Influence of the pore size on optical and mechanical properties of ecoflex sponges
Authors: Kocaman Kabil Fatmanur , Oral Ahmet Yavuz 
Published: February 2024

Abstract
Silicone polymers have various applications such as sensors, energy harvesters, soft robotics, prosthetics and implants. Ecoflex has become one of the most remarkable silicone polymers due to its special mechanical properties which include extreme stretchability and biocompatibility. In recent years, interest in porous silicone elastomers has increased in order to improve the absorption, flexibility and chemical activity of the material by increasing the surface area. In this study, porous Ecoflex 00-30 silicone elastomer material was prepared by using the low-cost sugar molding technique and its mechanical, optical and surface properties were investigated. In addition, we report on the influence of pore size on these properties of Ecoflex. Our results demonstrate that the Ecoflex material, which has a porous structure, has a more flexible structure. We have observed that the Ecoflex’s stretchability increased with pore size, especially in the 420–850 μm range.