bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluid-structure interaction dynamic analysis of large civil aircraft tank sloshing
Authors: Xu Chengliang , Xu Feng 
Published: May 2024

Abstract
To meet the requirements of passengers, the tank volume of large civil aircraft is gradually increasing, which brings certain risks. Under different 0 pertaining conditions during the flight, the liquid in the tank will cause structural failure and affect the aircraft’s safety. Therefore, based on the assumption of an ideal fluid, the smooth particle method (SPH) combined with the finite element method (FEM) is used to establish the coupling dynamic equation between the tank and the liquid. The effects of sloshing impact on the water tank under different filling rates were studied, and the influences of the water wave shape, the center of gravity shift, stress distribution, and deformation of the tank were obtained. The results show that the mass accumulation of water particles occurs in the acceleration stage, the relative center of gravity changes greatly in less water, and the accumulated liquid greatly influences the tank under the action of inertia. The more liquid in the tank is, the more the impact effect on the tank increases. The analysis results provide some reference for the analysis and design of tank anti-sway plates and flight attitude adjustment.
Joint stress of a hinged platform composed of eight boxes
Authors: Zhao Jiancheng , Zhang Bihui , An Hao , Sun Rui 
Published: May 2024

Abstract
The box-type hinged platform has important applications in ocean engineering. In this paper, a multi-module assembled box-type platform is described. The mid-section load of the platform is numerically simulated based on the three-dimensional velocity potential theory and the indirect time-domain method through the hydrodynamic module AQWA in ANSYS. The stress of the hinged joints of platforms was performed using finite element analysis software in ANSYS software. The results show that: (1) In irregular waves, the shear force and bending moment in the middle section of the platform increases with the increase of the significant wave height; (2) Under the same towing scheme, the stress of the hinged joints between box platforms shows an increasing trend with the increase of wave level. Under the same wave working condition, the stress at the uniaxial nut of the hinged joints is relatively high, which is prone to fracture.
Computations on fall of the leaning tower with considering air resistance
Authors: Xie Cuili 
Published: May 2024

Abstract
The free fall of a sphere was studied by considering air buoyancy and resistance. After selecting the reasonable drag coefficient formula recommended by the literature, partial differential formulas on the motion of balls falling in the Leaning Tower of Pisa are solved. The variation process of acceleration, velocity and displacement over time during the falling process of two spheres is obtained. The research results indicate that the kinematics of free fall considering air resistance is different from that neglecting air resistance. Air Resistance must be considered in the free fall of the solid ball after 0.3005 seconds. In the free fall of the leaning tower, air resistance makes the solid ball land at 0.4418 seconds which is earlier than the hollow. The variation of the acceleration of a solid ball with time can be described by a second-order function a=-0.115t2
-0.022t+9.801. Velocity does not satisfy the product of acceleration and time but can be described as a polynomial function of the velocity variation with time v = c1t2
+ c2t + c3
. About the relationship between displacement and time, for a solid sphere, displacement is proportional to 1.9526 power of time h=5.4945t1.9526
, while for a hollow sphere, it cannot be expressed by a function. The relationship between air resistance and velocity during the falling process of an iron ball satisfies a polynomial function Fd
=c1v2
-c2v+c3
rather than a simple relationship where air resistance is directly proportional to the first or second power of speed, which was used in many papers as a reasonable assumption.
Performance investigation of doped multi-layer graphene nanoribbon as interconnects in modern technology nodes
Authors: Wu Qixiao , Pan Zhongliang 
Published: May 2024

Abstract
In this paper, the performance of intercalation doped multilayer graphene nanoribbons (MLGNR) with modern technology nodes is meticulously investigated. An unconditionally stable FDTD method is used to analyze the transient output of the circuit. Several cases of MLGNR interconnects under different doping materials, stacking directions and contact modes have been discussed. With multiple experiments carried out, it is shown that the Li-doped MLGNR interconnect with vertical stacking orientation has the most outstanding performance, which has the least delay compared with the traditional Cu interconnect and other counterparts in 3-nm and 5-nm nodes. In summary, the Li-doped vertically stacked MLGNR is very promising for carbon nano interconnects in the next generation of integrated circuits.
The Impact and analysis of nuclear power plant’s steam extraction and heating modification on the turbine
Authors: Li Shuaishuai , Qu Tianzuo , Wang Dalin 
Published: May 2024

Abstract
A certain nuclear power unit uses the circulating water heated by the steam extraction from the high-pressure cylinder exhaust pipe of the steam turbine through modification, and the pressurized heating circulating water is supplied to the outside of the plant. As it is the first large-scale model of steam extraction heating in domestic nuclear power, the heating will have a certain impact on the steam turbine. Therefore, it is necessary to analyze the impact of large-scale steam extraction on the steam turbine and propose corresponding countermeasures to provide relevant references for subsequent nuclear power extraction and heating modification.
Heat exchange characteristics between u-shaped butted well and reservoir
Authors: Qu Yanlin , Li Fengming , Wang Zhaoliang 
Published: May 2024

Abstract
The geothermal resources in Shandong are relatively abundant. However, due to geological conditions, the high pressure of formation water reinjection makes it difficult and costly to achieve a 1:1 ratio of formation water extraction/reinjection during geothermal resource extraction. This causes waste of formation water resources and does not meet environmental protection requirements. The U-shaped butted well heat exchanger at the bottom of the well can achieve “heat extraction without water extraction”, effectively solving the problems of difficult formation water reinjection, pipeline reservoir corrosion, and reservoir damage in Shandong. Therefore, to explore the heat exchange characteristics between the U-shaped butted well heat exchanger at the bottom of the well and the reservoir, it is necessary to study various parameters of the heat exchanger operation. To better reflect the heat transfer status between the butted well and the soil, FLUENT software was used for simulation. Through simulation, the operation diagram of the generator after the comprehensive renovation was analyzed, guiding the operation of the U-shaped butted well heat exchanger.
Synthesis of biomass nitrogen-doped catalysts and their electrocatalytic performance in fuel cells
Authors: Ren Guohong , Sun Wei , Chen Yuting , Liu Chunyu , Song Kangle , Liu Xiaohong , Liu Zhongsu 
Published: May 2024

Abstract
At present, biomass materials have the characteristics of low cost, stability, and relatively high activity, which is expected to replace platinum-based (Pt) materials as cathode catalysts. In this paper, Zn, Fe-N-C catalyst materials and Fe-N-C catalyst were composited by high-temperature calcination. Their crystal and morphological structures were featured by X-ray diffraction instruments (XRD) and scanning electron microscopy (SEM). Their activity and stability to oxygen reduction were tested by an electrochemical workstation, and it was found that Zn, Fe-N-C catalyst materials had the best performance. The investigation of this paper can furnish an effective method for oxygen reduction reaction catalysts.
Analysis of the correlation between GIS partial discharge current waveform and charge quantity with UHF signals
Authors: Qian Hanming , Zeng Xiangjun , Zhou Ke , Zhang Wei 
Published: May 2024

Abstract
The Ultra-High Frequency (UHF) method, as a crucial technology for online GIS monitoring, struggles with the issue of being unable to accurately reflect the number of partial discharges, which poses a significant challenge for this technique. To examine the relationship between partial discharge waveforms, charge quantity, and UHF signals, a physical field model of partial discharge is developed using finite element simulation software, allowing a comparison of the peak-to-peak values of UHF signals with the parameters of the partial discharge current. Research demonstrates a roughly linear relationship between the peak-to-peak values of UHF signals and the magnitude of the partial discharge current but no definitive connection with the discharge quantity. These significant findings guide the quantitative detection of partial discharges in electrical equipment using the UHF method.
Active power control of wind turbine based on fuzzy pitch control
Authors: Liu Chengzhi , Li Qiang , Wang Chenggen , Xv Tianyi , Gu Wei , Yin Minghui 
Published: May 2024

Abstract
With the continuous increase in wind power penetration rate, wind turbine generators (referred to as WTGs or wind turbines) need to have the capability of active power control (APC) to respond to grid power commands. To reduce the burden of pitch control on wind turbines, existing studies have adopted a technological approach that uses variable-speed operation of the wind rotor instead of pitch control. Typically, pitch control is only initiated at the speed boundaries to limit variable-speed operation within the speed range. However, due to the influence of factors such as wind speed, rotor speed and control parameters, there is a noticeable saturation phenomenon in pitch control at the speed boundaries, which can affect the variable-speed process of the wind rotor and APC performance within the speed range. Therefore, this paper determines whether blade pitch adjustment needs to be performed in advance when the wind turbine operates within the speed range based on the rotor speed state. This avoids the pitch action at the speed boundaries and the associated pitch saturation problem. The results show that the proposed method in this paper reduces the frequency of the rotor speed reaching the speed boundaries by performing pitch actions within the speed range. This alleviates the influence of pitch saturation on the variable-speed process of the wind rotor, as well as the occurrence of overspeed and electromagnetic power drop, thereby improving the APC performance of the wind turbine.
Design and testing of a high-performance solar LED streetlight
Authors: Peng Manman , Li Chaoqun , Li Junmin 
Published: May 2024

Abstract
This paper presents the development and validation of a high-performance solarpowered charging streetlight. Our controller incorporates various charging modes, including MPPT charging, constant current charging, and constant voltage charging, and the controller can automatically change the charging mode based on the battery level. The streetlight can achieve brightness adjustment through PWM adjustment. The controller turns off the streetlights once the battery voltage reaches the over-discharge protection voltage. However, turning off the streetlights inevitably results in a voltage rebound above the over-discharge protection voltage. Consequently, the streetlights enter a cycling pattern of illumination and extinguishment. We have addressed this issue by incorporating a voltage rise threshold in the controller program, effectively preventing the streetlights from cycling between illumination and extinguishment. The MCU (Micro Controller Unit) can output multiple sets of PWM waves, where each set can control the on/off state of an LED light group. Combining multiple LED groups enables the driving and control of high-power LED street lights. We designed and constructed two solar-powered LED lighting systems to demonstrate the practicality of our approach. Extensive long-term outdoor field tests validate the robust performance of our control system.
Transformer parameter estimation in distribution network based on deformable transformer
Authors: Sun Zhiqing , Xuan Yi , ZikaiCao  , Liu Jian , Dai Tiechao , Liu Weihao , Ye Gangjin , Liang Yundan , Huang Jianping , Huang Yi , Fan Libo , Liu Xingye , Zhang Jiansong , Jin Minhao , Huang Jiabin 
Published: May 2024

Abstract
With the large number of distributed power sources and the dynamic change of load, the abnormal parameters of distribution transformers become more and more complicated. So it is particularly important to estimate their parameters accurately. For a low voltage distribution network with a limited number of measuring equipment, a Transformer parameter estimation method based on a Deformable Transformer is proposed in this paper. Firstly, a Transformer parameter estimation model based on a Deformable Transformer network is established by using historical measurement data. Then, a quality evaluation method of parameter estimation is proposed to test the accuracy of parameter estimation. Finally, the effectiveness of the proposed method is verified by practical data.
Evaluation of heat transfer correlations for two-phase flow boiling in twisted tapes inserted tubes
Authors: He Yan , Tang Chao , Chen Dongsheng 
Published: May 2024

Abstract
Many experimental researches were conducted in the twisted tapes inserted tubes, and many correlations were proposed and evaluated. However, most of the evaluations were based on specific experimental data, and the number of correlations evaluated was limited in each paper. This paper conducted a review of correlations and experimental investigations of the two-phase flow boiling heat transfer coefficient for twisted tapes inserted tubes, the key forms of the 5 correlations were reviewed, and the prediction accuracy of the 5 correlations was evaluated against the 508 published experimental data. This paper proposed a new correlation which has a MAD of 17.2%, 10.2% lower than the best existing correlation.
Periodic sampling and count rate correction of the low energy X-ray telescope on board the Insight- Hard X-ray modulation telescope
Authors: Li W. , Lu J.B. , Zhao X.F. , Cui W.W. , Yang Y.J. , Chen Y. 
Published: May 2024

Abstract
The Low Energy X-ray Telescope (LE) is an important
instrument of the Insight-Hard X-ray Modulation Telescope
(Insight-HXMT), which performs scanning and point observation in the
soft X-ray energy band (0.7–13 keV). Since its launch in 2017,
it has conducted a large number of scientific observations and
achieved significant astronomical discoveries. LE is composed of
three detector boxes and an electronic control box. The data
acquisition system of LE is designed to use periodic sampling, which
solves the problem of unstable noise peaks. Data loss may occur when
observing X-ray bursts, and periodic sampling provides a method of
correcting light curves. In addition, in the South Atlantic Anomaly
(SAA) or where the count rate of the particle monitor on the
Insight-HXMT is very high, LE automatically switches into SAA
operating mode, and only a small number of events are
recorded. After data correction, the light curves can be estimated
to expand the astronomical achievements of LE.
Precipitation exacerbates spatial heterogeneity in the propagation time of meteorological drought to soil drought with increasing soil depth
Authors: Hu Chen , Xia Jun , She Dunxian , Wang Gangsheng , Zhang Liping , Jing Zhaoxia , Hong Si , Song Zhihong 
Published: May 2024

Abstract
The propagation of meteorological droughts to soil droughts poses a substantial threat to water resources, agricultural production, and social systems. Understanding drought propagation process is crucial for early warning and mitigation, but mechanisms of the propagation from meteorological drought to soil drought, particularly at varying soil depths, remain insufficiently understood. Here, we employ the maximum correlation coefficient method and the random forest (RF) model to investigate the spatiotemporal patterns and drivers of propagation time (PT) from meteorological drought to soil drought at four different depths across China from 1980 to 2018. Our findings reveal consistently higher PT in northern China and lower PT in southern China across varying soil depths, with more pronounced spatial heterogeneity with increasing soil depth. Furthermore, we identify temperature and precipitation as determinants of spatial patterns of PT in surface and deeper soil layers, respectively. Additionally, precipitation emerges as the dominant factor influencing changes in PT between different soil layers. Our study highlights a discernible shift in PT drivers from temperature to precipitation as soil depth increases and the significant impact of precipitation on exacerbating spatial heterogeneity in PT. This study contributes to an enhanced comprehension of the propagation process from meteorological drought to soil drought at different depths, which can aid in establishing practical drought mitigation measures and early warning systems.
Tunable polarization-independent and angle-insensitive ultra-broadband terahertz absorber with vanadium dioxide
Authors: Dong Liang , Xiang Huanqi , Zhu Lei , Wang Yun , Rong Miaoxin 
Published: May 2024

Abstract
In this paper, a tunable ultra-broadband terahertz metamaterial absorber is proposed based on the phase transition material of vanadium dioxide (VO2). The absorber cell consists of a petal-like monolayer vanadium dioxide, a dielectric layer, and a metal layer. The terahertz absorption bandwidth of more than 90% absorptance reaches 4.2 THz, which covers from 1.99 to 6.19 THz, and a relative bandwidth attains to 102.7%. By changing the conductivity of VO2, the absorbance of this structure can be dynamically adjusted from 2.4% to 98.96%. The physical mechanism of the perfect absorption in this paper is investigated by the impedance matching theory and electric field distributions. The results show that the strong coupling effect in the petal-like structure contributes to the broadening of the absorption spectrum, and the absorber is polarization-insensitive and wide-angle incidence-insensitive due to the symmetry of the cell structure. The metamaterial absorber designed in this paper is expected to have a wide range of applications in the fields of terahertz imaging, stealth, sensing and detection.
The Unique Job
Authors: Williams Abiodun 
Published: May 2024

AbstractThe first chapter outlines the formal responsibilities of the unique job of UN Secretary-General, and the Secretary-General’s different roles, including as a mediator of conflict, an administrator, and an initiator of ideas, policies, and norms. It provides an overview of the dynamic relationship between the Secretary-General and the Security Council, which is important for the UN’s activities, especially in managing international peace and security. It includes an account of the process that led to Kofi Annan’s appointment as Secretary-General after the United States (US) decided for largely domestic reasons to veto a second term for his predecessor, Boutros Boutros-Ghali. It examines Annan’s bold vision for the Secretary-Generalship which emphasized that the UN, founded in the name of “We the peoples,” must advance their interests in development, security, and human rights. It explains how Annan used the “bully pulpit” to articulate a global agenda, to resist the pressure of powerful member states, and to influence global public opinion.
Conflict Prevention
Authors: Williams Abiodun 
Published: May 2024

AbstractChapter 2 considers Kofi Annan’s initiatives relating to the primary purpose of the UN, which is to prevent war and to strengthen means for conflict resolution. He regarded preventing deadly conflicts as vital for the preservation of human life and for promoting sustainable development and human rights. It examines his ideas on moving the UN “from a culture of reaction to a culture of prevention” and how he tried to apply them in the organization’s work. It includes a case study of his successful mediation between Nigeria and Cameroon over the disputed Bakassi Peninsula that prevented a war between the two countries. The chapter also discusses his role in providing clear remedies to the deficiencies of UN peacekeeping, and in establishing the UN’s Peacebuilding Architecture consisting of the Peacebuilding Commission, the Peacebuilding Fund, and the Peacebuilding Support Office to support sustainable peace.
Pollinator shift ensures reproductive success in a camouflaged alpine plant
Authors: Huang Tao , Song Bo , Chen Zhe , Sun Hang , Niu Yang 
Published: May 2024

Abstract

Background and Aims
There are intrinsic conflicts between signalling to mutualists and concealing (camouflaging) from antagonists. Like animals, plants also use camouflage as a defence against herbivores. However, this can potentially reduce their attractiveness to pollinators.

Methods
Using Fritillaria delavayi, an alpine camouflaged plant with inter-population floral colour divergence, we tested the influence of floral trait differences on reproduction. We conducted pollination experiments, measured floral morphological characteristics, estimated floral colours perceived by pollinators, analysed floral scent and investigated reproductive success in five populations.

Key Results
We found that the reproduction of F. delavayi depends on pollinators. Under natural conditions, a flower-camouflaged population had 100 % fruit set and similar seed set to three out of four yellow-flowered populations. Bumblebees are important pollinators in the visually conspicuous yellow-flowered populations, whereas flies are the only pollinator in the flower-camouflaged population, visiting flowers more frequently than bumblebees. The camouflaged flowers cannot be discriminated from the rock background as perceived by pollinators, but may be located by flies through olfactory cues.

Conclusions
Collectively, our results demonstrate that the flower-camouflaged population has different reproductive traits from the visually conspicuous yellow-flowered populations. A pollinator shift from bumblebees to flies, combined with high visitation frequency, compensates for the attractiveness disadvantage in camouflaged plants.