bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative Influence of Wind Farm Reactive Power and Voltage Control Capability on Hunan Power Grid Thermal Power Spinning Reserve
Authors: Wang Ding , Xu Ming , Hu Zhen , Shen Yangwu , Hao Luxi , Zuo Jian 
Published: March 2022

Abstract
Affected by factors such as the inverse distribution of power sources and loads in the province, and the mismatch between the construction of load center power sources and load growth, the problem of voltage stability in central and southern Hunan is prominent, which mainly restricts the thermal power maximum operating capacity of the Hunan Power Grid. Under the heavy load mode, the hydro power units and thermal power units operating in the province need to reserve a certain amount of spinning reserve to response the voltage stability problems in central and southern Hunan. Thus, it leads to insufficient power supply during peak load periods. In recent years, the grid load has maintained rapid growth, and the increase in power sources is mainly the wind power. Affected by the anti-peak-shaving characteristics of wind power, the lack of wind power has aggravated the problem of insufficient power supply. Actually, the wind turbine is in a hot standby state during standby/backup, and its grid-connected converter is still in a grid-connected state within four hours. Besides, the continuous running SVG in the wind farm booster station can still be used temporarily. The above devices can provide reactive power support to the power grid during the transient process. Therefore, this paper takes the southern Hunan region as an example, and quantified the reduced thermal power requirement reserve by analyzing the reactive power support effect of the grid-connected wind farms. In this way, the power supply capacity can be improved.
Study on Galvanic Corrosion Characteristics of the Ground Grid with Different Metal Conductors in the Converter Station
Authors: Lu Yuxin 
Published: March 2022

Abstract
The galvanic corrosion of grounding net in converter station seriously affects its dispersion performance. However, the corrosion potential difference between different metal conductors will aggravate the corrosion speed of the converter station grounding network. In this paper, the variation of corrosion potential difference and corrosion current of dissimilar metals in water medium and soil medium is analyzed by experiments. In the two media, when the circuit resistance is high, the galvanic corrosion is mainly affected by ohmic polarization. Then, CDEGS simulation was used to obtain the change rule of corrosion current under different circuit resistance, and the simulation results are compared with the experimental results. The results show that with the increase of circuit resistance, the corrosion potential difference is basically unchanged, while the corrosion current decreases gradually, and when the circuit resistance increases to a certain margin, the corrosion current decreases gently. When the current density is less than 0.47A/m2, ohmic polarization can be used to approximate analyze the galvanic corrosion of dissimilar metal connections.
Research on Decoupling Simulation of Electric Platform System Based on ADAMS
Authors: Zhao Yulong , Zhang Yuan , Wang Yan , Liu Haiyang 
Published: March 2022

AbstractAiming at the problem that the cross-linking coupling between the electric cylinders affects the stable operation of the six-degree-of-freedom electric platform, the decoupling design and co-simulation verification of the electric platform are carried out. First, considering the integrity of the platform, the inertial coupling matrix of the electric platform and its characteristics are analysed; further, the overall decoupling system of the electric platform is designed based on the fuzzy decoupling network; finally, the electric platform model is constructed based on ADAMS, and the virtual platform is constructed. A co-simulation analysis was carried out to verify the effectiveness of the decoupling design of the electric platform system.
A Novel DC Circuit Breaker with Fast Breaking Capability in Full Current Range
Authors: Zhao Xiaomin , Wang Jun , Wang Yawen , Kang Qiong , Long Chen , Shen Jaming 
Published: March 2022

Abstract
With the rapid development of DC power system in recent years, more stringent requirements have been put forward for the rapid reliability of DC circuit breakers. At present, most hybrid circuit breakers widely used create artificial zero crossing by injecting current opposite to short-circuit current. However, when it comes to the small current, the injected current may reverse puncture the contacts of the high-speed mechanical switch. And this results in the difficulty of extinguishing the arc between the contacts of the high-speed mechanical switch during disconnection, prolonging the disconnection time and adversely affecting the system. This paper presents a double break DC circuit breaker structure based on double capacitor structure. In the process of current breaking, the capacitor with small capacitance is used to commutate for small current, and the double capacitor parallel method is used to complete the current transfer for large current. The working principle of the circuit breaker is analysed, and the appropriate parameters are selected through simulation.
Research on Detection Method of Insulator Image Based on Improved Faster R-CNN
Authors: Pha Samphors , Zheng Hanbo , Sun Yonghui 
Published: March 2022

Abstract
This study proposes the use of Improved Faster Region-Convolutional Neural Network (R-CNN) in target detection for insulator images in power systems. Faster R-CNN is essentially a combination of the Fast R-CNN and the Regional Proposal Network (RPN). The Faster R-CNN method, which is being used today, is an extension and improvement of the Fast R-CNN. The Improved Faster R-CNN is particularly highly effective in the detection of occluded targets and those with different aspect ratios and scales. Through the various experiments conducted in the study, it has been demonstrated that the improved Faster R-CNN is highly effective in detecting insulator images with different scales and with different aspect ratios. Furthermore, the improved Faster R-CNN is also very effective in detecting mutually occluded insulator images.
The radiation tolerance of a low voltage LDO developed for the CMS HGCAL on-detector electronics system
Authors: Irshad A. , Ceard L. 
Published: March 2022

Abstract
The CMS detector will undergo the replacement of its current endcap calorimeter by a new high granularity calorimeter (HGCAL). The new HGCAL will need to withstand much higher radiation levels than the present endcaps. This poses tight requirements on the front-end electronics, including the powering chain. As part of this chain, a low-dropout linear regulator (LDO) has been designed and prototyped for post-regulation for HGCAL, providing extremely low noise and stable power to the analog front-end. We present results from tests of the LDO, including from a detailed irradiation campaign.
Optofluidic conical microresonator for precise displacement sensing
Authors: Mohammadfam B. , Mahdieh M.H. , Veladi H. 
Published: March 2022

Abstract
In the present work we report fabrication of a compact
optical displacement sensor based on whispering gallery mode with
common materials on Polydimethylsiloxane (PDMS) medium with mold
master technique. Conical and hollow geometry of microcavity filled
with Rhodamine B-doped Glycerol as active medium. The fabricated
device can be utilized for sensing applications. Coupling junction
can be tuned so that moving the conical microcavity of about
100 μm in the axial direction is equivalent to ∼1.5 nm
shift in resonant wavelength. Also, a small change in concentration
of active medium results in a shift in the resonant wavelength which
provides the feasibility of sensing the refractive index. The
proposed structure demonstrates the ability of considerably
high-resolution sensing for fine displacement steps which is limited
by the resolution of the spectrometer (0.6 nm).
Nitrogen cycle impacts on CO2 fertilisation and climate forcing of land carbon stores
Authors: Huntingford Chris , Burke Eleanor J , Jones Chris D , Jeffers Elizabeth S , Wiltshire Andrew J 
Published: March 2022

Abstract
Anthropogenic fossil fuel burning increases atmospheric carbon dioxide (CO2) concentration, which is adjusting the climate system. The direct impact of rising CO2 levels and climate feedback alters the terrestrial carbon stores. Land stores are presently increasing, offsetting a substantial fraction of CO2 emissions. Less understood is how this human-induced carbon cycle perturbation interacts with other terrestrial biogeochemical cycles. These connections require quantification, as they may eventually suppress land fertilisation, and so fewer emissions are allowed to follow any prescribed future global warming pathway. Using the new Joint UK Land Environment Simulator-CN large-scale land model, which contributed to Coupled Model Intercomparison Project Phase 6 as the land component of the UK Earth System Model v1 climate model, we focus on how the introduction of the simulated terrestrial nitrogen (N) cycle modulates the expected evolution of vegetation and soil carbon pools. We find that the N-cycle suppresses, by approximately one-third, any future gains by the global soil pool when compared to calculations without that cycle. There is also a decrease in the vegetation carbon gain, although this is much smaller. Factorial simulations illustrate that N suppression tracks direct CO2 rise rather than climate change. The finding that this CO2-related effect predominantly influences soil carbon rather than vegetation carbon, we explain by different balances between changing carbon uptake levels and residence times. Finally, we discuss how this new generation of land models may gain further from emerging point knowledge held by the detailed ecological modelling community.
Seasonality of inundation in geographically isolated wetlands across the United States
Authors: Park Junehyeong , Kumar Mukesh , Lane Charles R , Basu Nandita B 
Published: March 2022

Abstract
Inundation area is a major control on the ecosystem services provisioned by geographically isolated wetlands. Despite its importance, there has not been any comprehensive study to map out the seasonal inundation characteristics of geographically isolated wetlands over the continental United States (CONUS). This study fills the aforementioned gap by evaluating the seasonality or the long-term intra-annual variations of wetland inundation in ten wetlandscapes across the CONUS. We also assess the consistency of these intra-annual variations. Finally, we evaluate the extent to which the seasonality can be explained based on widely available hydrologic fluxes. Our findings highlight significant intra-annual variations of inundation within most wetlandscapes, with a standard deviation of the long-term averaged monthly inundation area ranging from 15% to 151% of its mean across the wetlandscapes. Stark differences in inundation seasonality are observed between snow-affected vs. rain-fed wetlandscapes. The former usually shows the maximum monthly inundation in April following spring snowmelt (SM), while the latter experiences the maximum in February. Although the magnitude of inundation fraction has changed over time in several wetlandscapes, the seasonality of these wetlands shows remarkable constancy. Overall, commonly available regional hydrologic fluxes (e.g. rainfall, SM, and evapotranspiration) are found to be able to explain the inundation seasonality at wetlandscape scale with determination coefficients greater than 0.57 in 7 out of 10 wetlandscapes. Our methodology and presented results may be used to map inundation seasonality and consequently account for its impact on wetland functions.
Diffusion-mediated surface reactions and stochastic resetting
Authors: Bressloff Paul C 
Published: March 2022

Abstract
In this paper, we investigate the effects of stochastic resetting on diffusion in

R

d

\
U

, where

U

is a bounded obstacle with a partially absorbing surface

∂
U

. We begin by considering a Robin boundary condition with a constant reactivity κ
0, and show how previous results are recovered in the limits κ
0 → 0, ∞. We then generalize the Robin boundary condition to a more general probabilistic model of diffusion-mediated surface reactions using an encounter-based approach. The latter considers the joint probability density or generalized propagator P(x, ℓ, t|x
0) for the pair (X

t
, ℓ

t
) in the case of a perfectly reflecting surface, where X

t
and ℓ

t
denote the particle position and local time, respectively. The local time determines the amount of time that a Brownian particle spends in a neighborhood of the boundary. The effects of surface reactions are then incorporated via an appropriate stopping condition for the boundary local time. We construct the boundary value problem satisfied by the propagator in the presence of position resetting, and use this to derive implicit equations for the marginal density of particle position and the survival probability. We highlight the fact that these equations are difficult to solve in the case of non-constant reactivities, since resetting is not governed by a renewal process. We then consider a simpler problem in which both the position and local time are reset. In this case, the survival probability with resetting can be expressed in terms of the survival probability without resetting, which considerably simplifies the analysis. We illustrate the theory using the example of a spherically symmetric surface. In particular, we show that the effects of a partially absorbing surface on the mean first passage time (MFPT) for total absorption differs significantly if local time resetting is included. That is, the MFPT for a totally absorbing surface is increased by a multiplicative factor when the local time is reset, whereas the MFPT is increased additively when only particle position is reset.
Edge-mode polariton chains in the dielectric whispering gallery modes and two-dimensional material’s topological system
Authors: Chai Zhen , Wang Weiyi , Tian Zhongxing , Xu Yuting 
Published: March 2022

Abstract
Topological polaritons are a new topological phenomenon that has a combination of advantages such as strong nonlinearity, low effective mass, and topological invariants. However, the actual configurations of topological polaritons based on two-dimensional materials have not been discussed yet. In this paper, we theoretically demonstrate a Su-Schrieffer-Heeger (SSH) model (Sinev et al 2015 Nanoscale
7 11904; Dobrykh et al 2018 Phys. Rev. Lett.
121 163901; Qi et al 2020 Phys. Rev. A 102 022404) with topological polaritons by TiO2 whispering gallery modes and nanodisk arrays coupled with two-dimensional transition metal dichalcogenides (TMDCs) exciton materials. The transverse electric-polarized strong evanescent fields around the TiO2 nanodisks coupled with the TMDCs excitons for each atom can construct strong coupling between exciton-polaritons with a distinct resonant Rabi splitting dispersion of approximately 14 nm. By changing the distance between adjacent nanodisks, we observed obvious edge states for the SSH polariton chain at the wavelength of polaritons. This study paves the way toward new topological polaritons in large nonlinear devices with an edge transport based on two-dimensional materials.
Facile synthesis of Veitchia merilli coir-based porous carbon using combined chemical and physical activation routes as electrode material for energy storage
Authors: Farma R , Anugrah A P , Apriyani I , Awitdrus A 
Published: March 2022

AbstractThis study aimed to prepareVeitchia merillicoir (VMC) through pre-carbonisation process, followed by chemical activation using potassium hydroxide as an activating agent. The experiment was conducted under different pyrolytic physical activation temperatures of 650, 700, and 750 °C with the code VMS-650, VMS-700, and VMS-750 for each sample. Physical activation methods develop or modify the pore structure, specific surface area, and microstructure of activated carbon. Furthermore, the prepared VMCs were characterised using X-ray diffraction, Fourier transform infrared, scanning electron microscope, energy dispersive X-ray, and cyclic voltammetry with a symmetrical two-electrode system in 1 M H2SO4solution. The microstructure analysis showed that the VMC carbon electrode has an amorphous structure with two broad peaks at 2θangles around 26° and 44° corresponding to the (002) and (100) planes, with theLcVMS-700 having a value of 16.007 nm. The VMC electrode has a C≡C carbon bond as a functional group, which extends in bands from 2311.79 to 2373.51 cm−1. Meanwhile, the VMS-700 electrode shows a combined surface morphology of nanofibers as well as mesopores, and the energy dispersive X-ray results showed carbon content of 92.83%. The electrochemical properties of supercapacitor cells indicated this electrode had the highest specific capacitance value of 264.2 F g−1. From the obtained results, the respective physical and electrochemical properties of the carbon electrodes and supercapacitor cells showed that the activated VMC-700 at 700 °C is the optimum temperature to produce the best performance compared to 650 and 750 °C.
Spectroscopic studies on reduced graphene oxide behaviour in multi-step thermal reduction
Authors: Aditya Dominico Michael , Hardiansyah Andri 
Published: March 2022

Abstract
Graphene’s excellent electrical, mechanical, thermal and optical properties make it one of the most desirable materials for diverse applications. Nevertheless, mass producing graphene has been a challenge since the first discovery in 2004. Here, we conducted a fast, green and safe method: multi-step thermal reduction (MSTR) process combining the use of commercial microwave and conventional furnace as the first and second steps, respectively to reduce graphene oxide (GO). Both steps used common tools in a short time to minimise investment. By evaluating several characterisation methods, we show that the first step partially reduces GO by decomposing most hydroxyls, creating a double interlayer spacing distance of 9.381 Å and 3.590 Å with retained hydrophilic property. Meanwhile, the second step further decomposes oxygen functional groups, recovers structural defects and creates a porous layered structure with an average interlayer spacing distance of 3.504 Å, 3.413 Å and 3.393 Å for temperatures of 500, 650 and 800 °C, respectively. In short, MSTR is a viable option to mass produce graphene-based material with desired properties.
Size dependent local field enhancement factor of CdSe based core@shell spherical nanoparticles
Authors: Bergaga Garoma Dhaba , Ali Belayneh Mesfin , Debela Teshome Senbeta 
Published: March 2022

Abstract
We investigated the size dependent local field enhancement factor (LFEF) of CdSe@Ag and CdSe@ZnSe@Ag core/shell spherical nanoparticles theoretically and numerically within the framework of quasi-static approximation. From the potential distributions in the core, shell(s), and host medium, and using the modified Drude-Sommerfeld model, we separately obtained the expressions for LFEF of core/shell and core/spacer/shell nanocomposites. By changing the sizes of each of the components of the nanocomposites in these expressions, we found that the LFEF of CdSe@Ag increases with a decrease in the size of the core. At the same time, the resonance peaks are red shifted in the inner interface and blue shifted in the outer interface of the shell. The result also reveals that whether the shell radius is kept constant or decreased, increasing the core size produces a lower field enhancement factor showing that the core size is a crucial parameter to change the field enhancement factor of the dielectric core and metal shell nanoparticle (NP). When the spacer (ZnSe) is placed between the core (CdSe) and the shell (Ag), the resonance peaks increased with increase in the size of the core which was not observed in the case of the two layered core/shell nanocomposites having the same core and shell sizes. We also found that placing the spacer and varying the sizes of the core, the spacer, and the shell show different effects on the LFEF of the nanocomposite. The possibility of obtaining size dependent LFEF by adjusting the sizes of nanoparticles makes these nanocomposites attractive for applications in nonlinear optics, photocatalysis, and optoelectronics.
Microhardness and heat-resistance performance of ferromagnetic cobalt-molybdenum nanocrystals electrodeposited from an aqueous solution containing citric acid
Authors: Matsuda Tomoyuki , Saeki Ryusei , Hayashida Masamitsu , Ohgai Takeshi 
Published: March 2022

Abstract
Using a potentiostatic electrodeposition technique, nanocrystalline cobalt-molybdenum (Co-Mo) superalloys containing molybdenum oxide (MoOX) were synthesized from an aqueous solution containing citric acid. Molybdenum content in the alloys was controlled up to approximately 53% by adjusting the cathode potential during the alloy electrodeposition. Based on the XRD profiles and electron diffraction patterns, an amorphous-like nanocrystalline structure was observed in the alloys with high molybdenum content. XPS analysis revealed that the chemical state of electrodeposited molybdenum was almost metallic and the oxide state was also detected partially. According to the magnetization curves, the coercivity of electrodeposited Co-Mo alloys decreased down to approximately 72 Oe with increasing the molybdenum content up to around 53%. The microhardness reached 845 kgf mm−2 in the electrodeposited Co-53%Mo alloy and greatly exceeded that of pure cobalt (ca. 250–300 kgf mm−2). Heat resistance performance of the electrodeposited nanocrystalline Co-53%Mo alloy was improved by the Mo alloying effect because the recrystallization and oxidation behavior were not observed even if the annealing temperature was increased up to 700 °C.
Hydrogen adsorption behavior on AXenes Na2N and K2N: a first-principles study
Authors: Dong Shuping , Zhang Haona , Yu Shiqiang , Huang Baibiao , Dai Ying , Wei Wei 
Published: March 2022

Abstract
It is a consensus that the hydrogen economy has come to a standstill due to the lack of feasible hydrogen storage solutions, especially, the suitable hydrogen storage materials. In this work, the potential of a new kind of two-dimensional (2D) AXenes, Na2N and K2N, as hydrogen storage materials are evaluated by the first-principles calculations. In particular, we find that Na2N in T phase indicates a hydrogen storage capacity as high as 6.25 wt% with a desirable hydrogen adsorption energy of –0.167 eV per H2 molecule and a desorption temperature of 216 K, identifying T-phase Na2N to be a very promising reversible hydrogen storage material. In accordance to our results, H2–Na2N interaction causes H2 charge polarization, which is responsible for the moderate binding strength. In addition, Gibbs adsorption free energy reveals that the system will be more stable as more H2 molecules are loaded on the surface.