bluuebunny/crossref_metadata_2025 huggingface dataset:
Power of wavelets in analyses of transit and phase curves in the presence of stellar variability and instrumental noise
Authors: Csizmadia Sz. , Smith A. M. S. , Kálmán Sz. , Cabrera J. , Klagyivik P. , Chaushev A. , Lam K. W. F.
Published: May 2023

Context.Stellar photometric variability and instrumental effects, such as cosmic ray hits, data discontinuities, data leaks, instrument aging, and so on, lead to difficulties in the characterisation of exoplanets. Therefore, they can impact the accuracy and precision of the modelling and the detectability of their transits, occultations, and phase curves.

Aims.This paper is aimed at improving the transit, occultation, and phase-curve modelling in the presence of strong stellar variability and instrumental noise. To this end, we invoke the wavelet formulation.

Methods.We explored the capabilities of the software package Transit and Light Curve Modeller (TLCM). It is able to perform (1) a joint radial-velocity and light-curve fit or (2) a light curve-only fit. It models the transit, occultation, beaming, ellipsoidal, and reflection effects in the light curves (including the gravity-darkening effect). Here, the red noise, stellar variability, and instrumental effects were modelled via wavelets. The wavelet fit was constrained by prescribing that the final white noise level must be equal to the average of the uncertainties of the photometric data points. This helps to avoid overfitting and regularises the noise model. The approach was tested by injecting synthetic light curves into short-cadenceKeplerdata and modelling them.

Results.The method performs well over a certain signal-to-noise (S/N) ratio. We provide limits in terms of the S/N for every studied system parameter that is needed for accurate parameter retrieval. The wavelet approach is able to manage and remove the impact of data discontinuities, cosmic ray events, and long-term stellar variability and instrument ageing, as well as short-term stellar variability, pulsation, and flares (among others).

Conclusions.We conclude that precise light-curve models combined with the wavelet method and with well-prescribed constraints on the white noise are able to retrieve the planetary system parameters, even in the presence of strong stellar variability and instrumental noise, including data discontinuities.
Determination of small-scale magnetic fields on Sun-like stars in the near-infrared using CRIRES+
Authors: Hahlin A. , Kochukhov O. , Rains A. D. , Lavail A. , Hatzes A. , Piskunov N. , Reiners A. , Seemann U. , Boldt-Christmas L. , Guenther E. W. , Heiter U. , Nortmann L. , Yan F. , Shulyak D. , Smoker J. V. , Rodler F. , Bristow P. , Dorn R. J. , Jung Y. , Marquart T. , Stempels E.
Published: May 2023

Aims. We aim to characterise the small-scale magnetic fields of a sample of 16 Sun-like stars and investigate the capabilities of the newly upgraded near-infrared (NIR) instrument CRIRES+ at the Very Large Telescope in the context of small-scale magnetic field studies. Our targets also had their magnetic fields studied with optical spectra, which allowed us to compare magnetic field properties at different spatial scales on the stellar surface and to contrast small-scale magnetic field measurements at different wavelengths.

Methods. We analysed the Zeeman broadening signature for six magnetically sensitive and insensitive Fe I lines in the H-band to measure small-scale magnetic fields on the stellar surfaces of our sample. We used polarised radiative transfer modelling and non-local thermodynamic equilibrium departure coefficients in combination with Markov chain Monte Carlo sampling to determine magnetic field characteristics and non-magnetic stellar parameters. We used two different approaches to describe the small-scale magnetic fields. The first is a two-component model with a single magnetic region and a free magnetic field strength. The second model contains multiple magnetic components with fixed magnetic field strengths.

Results. We found average magnetic field strengths ranging from ∼0.4 kG down to < 0.1 kG. The results align closely with other results from high-resolution NIR spectrographs, such as SPIRou. It appears that the typical magnetic field strength in the magnetic region is slightly stronger than 1.3 kG, and for most stars in our sample, this strength is between 1 and 2 kG. We also found that the small-scale fields correlate with the large-scale fields and that the small-scale fields are at least ten times stronger than the large-scale fields inferred with Zeeman Doppler imaging. The two- and multi-component models produce systematically different results, as the strong fields from the multi-component model increase the obtained mean magnetic field strength. When comparing our results with the optical measurements of small-scale fields, we found a systematic offset two to three times stronger than fields in the optical results. This discrepancy cannot be explained by uncertainties in stellar parameters. Care should therefore be taken when comparing results obtained at different wavelengths until a clear cause can be established.
RUBIS: A simple tool for calculating the centrifugal deformation of stars and planets
Authors: Houdayer P. S. , Reese D. R.
Published: May 2023

Aims. We present the Rotation code Using Barotropy conservation over Isopotential Surfaces (RUBIS), a fully Python-based centrifugal deformation program that is available publicly. The code has been designed to calculate the centrifugal deformation of stars and planets resulting from a given cylindrical rotation profile, starting from a spherically symmetric non-rotating model.

Methods. The underlying assumption in RUBIS is that the relation between density and pressure is preserved during the deformation process. This leads to many procedural simplifications. For instance, RUBIS only needs to solve Poisson’s equation in either spheroidal or spherical coordinates, depending on whether the 1D model has discontinuities.

Results. We present the benefits of using RUBIS to deform polytropic models and more complex barotropic structures, thus providing insights into baroclinic models to a certain extent. The resulting structures can be used for a wide range of applications, including the seismic study of models. Finally, we illustrate how RUBIS is beneficial specifically in the analysis of Jupiter’s gravitational moments through its ability to handle discontinuous models while retaining a high accuracy compared to current methods.
An Analysis of the Three Realms of Musical Performing Arts in Bel Canto
Authors: He Hao , Ng Elena
Published: May 2023

The three realms of music performance are intuition, interest, and style. Intuition is a feeling in music performance; interest is a choice that one persists in, and style is the result of effort and perception based on it. As the highest artistic achievement in the world of singing today, Bel canto (Italian: Bel canto) refers to the singing method in which the larynx blows the vocal cords with exhaled air while maintaining the inhalation position so that the open resonance cavity can resonate completely and evenly. This article, based on the research of the three realms of musical performing art, analyses the application of the three realms of musical performing art in Bel canto, aiming to let Bel canto performance better grasp the application of this art.
Information Teaching in Computer-Aided Design Course
Authors: Li Hong , Li Xuesong , Qu Zhuangzhuang
Published: May 2023

In view of the characteristics of computer-aided design courses and the particularity of teaching objects, information teaching is integrated into the teaching process, and a series of reform measures related to teaching content, teaching methods, practical teaching and assessment methods are proposed, and practice shows that students’ enthusiasm for learning is greatly improved and the teaching effect is significantly improved.
The Development of Temple Culture in Taiwan
Authors: Yeh Ming-Chao
Published: May 2023

The prevalence of temples in Taiwan is indeed a unique phenomenon. According to literature and news reports, the development of traditional religions was not encouraged during the Japanese Occupation Period and the Kuomintang administration. Rather, religious practice in Taiwan was controlled and derogated. This study investigated the structural factors affecting the flourishing development of well-known temples in Taiwan based on the religious and cultural policies from the Japanese Occupation Period to Kuomintang’s lifting of martial law. It also attempted to understand the impact of local factions and clientelism on temple culture.
Common words for Solon Evenki and Buryatia Mongolian
Authors: Wuriqimuge
Published: May 2023

The Solon Ewenki and the Buryat Mongols both belong to cross-border peoples, living in China, Mongolia and Russia. The Solon Ewenki and Buryat Mongols in China live in the China-Mongolia-Russia border areas of Hulunbuir, Inner Mongolia. There are many commonalities or similarities in history, culture, society, religion and language, especially, the common relationship shown in linguistics is more obvious. According to the first-hand language information we have, there is a certain number of shared words in Solon Ewenki and Buryat Mongolian, These common words mainly involve nouns, verbs, pronouns, adjectives and so on. Through the analysis and study of these common words, we can further scientifically explore the complex and changeable deep historical relationship between the Ewenki people and the Buryat Mongols.
Exploring the Construction of MPAcc Business Ethics and Accounting Ethics Case Library
Authors: Zhang Lijuan , Tian Zixuan , Wang Yanwei
Published: May 2023

It is difficult to support the needs of MPAcc teaching due to the insufficient number of case libraries for business ethics and accounting ethics courses. Therefore, this paper discusses the necessity of the case library from the current situation of case library construction, and analyzes the research and construction of the case library of business ethics and accounting ethics course, and proposes, some corresponding solutions to improve students’ classroom learning effect, so as to better cultivate high quality and high level applied talents, which has a certain reference role for universities to improve the subject case library.
Prevention of Venous Thromboembolism in Medical Patients with Thrombocytopenia or with Platelet Dysfunction: The Last 10 Years
Authors: Tufano Antonella , Brenner Benjamin
Published: May 2023

Current guideline recommendations for primary prophylaxis of venous thromboembolism (VTE) are based on randomized clinical trials that usually exclude subjects at a potentially high risk of bleeding complications. For this reason, no specific guideline is available for thromboprophylaxis in hospitalized patients with thrombocytopenia and/or platelet dysfunction. However, except in patients with absolute contraindications to anticoagulant drugs, antithrombotic prophylaxis should always be considered, for example, in hospitalized cancer patients with thrombocytopenia, especially in those with multiple VTE risk factors. Low platelet number, platelet dysfunction, and clotting abnormalities are also very common in patients with liver cirrhosis, but these patients have a high incidence of portal venous thrombosis, implying that cirrhotic coagulopathy does not fully protect against thrombosis. These patients may benefit from antithrombotic prophylaxis during hospitalization. Patients hospitalized for COVID-19 need prophylaxis, but frequently experience thrombocytopenia or coagulopathy. In patients with antiphospholipid antibodies, a high thrombotic risk is usually present, even in the presence of thrombocytopenia. VTE prophylaxis in high-risk conditions is thus suggested in these patients. At variance with severe thrombocytopenia (< 50,000/mm3), mild/moderate thrombocytopenia (≥ 50,000/mm3) should not interfere with VTE prevention decisions. In patients with severe thrombocytopenia, pharmacological prophylaxis should be considered on an individual basis. Aspirin is not as effective as heparins in lowering the risk of VTE. Studies in patients with ischemic stroke demonstrated that thromboprophylaxis with heparins is safe in these patients also during antiplatelet treatment. The use of direct oral anticoagulants in the prophylaxis of VTE in internal medicine patients has been recently evaluated, but no specific recommendation exists for patients with thrombocytopenia. The need for VTE prophylaxis in patients on chronic treatment with antiplatelet agents should be evaluated after assessing the individual risk of bleeding complications. Finally, the selection of patients who require post-discharge pharmacological prophylaxis remains debated. New molecules currently under development (such as the inhibitors of factor XI) may contribute to improve the risk/benefit ratio of VTE primary prevention in this setting of patients.
Human Genetic Variation in F3 and Its Impact on Tissue Factor–Dependent Disease
Authors: Park Jin K. , Brake Marisa A. , Schulman Sol
Published: May 2023

Tissue factor (TF) is the primary initiator of blood coagulation in humans. As improper intravascular TF expression and procoagulant activity underlie numerous thrombotic disorders, there has been longstanding interest in the contribution of heritable genetic variation in F3, the gene encoding TF, to human disease. This review seeks to comprehensively and critically synthesize small case–control studies focused on candidate single nucleotide polymorphisms (SNPs), as well as modern genome-wide association studies (GWAS) seeking to discover novel associations between variants and clinical phenotypes. Where possible, correlative laboratory studies, expression quantitative trait loci, and protein quantitative trait loci are evaluated to glean potential mechanistic insights. Most disease associations implicated in historical case–control studies have proven difficult to replicate in large GWAS. Nevertheless, SNPs linked to F3, such as rs2022030, are associated with increased F3 mRNA expression, monocyte TF expression after endotoxin exposure, and circulating levels of the prothrombotic biomarker D-dimer, consistent with the central role of TF in the initiation of blood coagulation.
Derivaciones quirúrgicas para artroplastia total de cadera desde la atención primaria: la utilidad de los Criterios de Uso Apropiado de la AAOS
Authors: Diaz-Ledema Claudio , Bengoa Francisco
Published: May 2023

Antecedentes Se ha comprobado que los médicos de atención primaria (MAPs) tienen falta de claridad respecto a las indicaciones para la artroplastia total de cadera (ATC), lo que hace que el proceso de derivación quirúrgica sea propenso a la variabilidad y la inconsistencia. Los Criterios de Uso Apropiado (Appropriate Use Criteria, AUC, en inglés) de la American Academy of Orthopaedic Surgeons (AAOS-AUC) son una herramienta de apoyo a la toma de decisiones basada en la evidencia que ayuda a los médicos a seleccionar para quién debe indicarse el tratamiento. Este estudio tiene como objetivo comparar la tasa de referencias quirúrgicas de ATC realizadas por MAPs utilizando la herramienta AAOS-AUC y la tasa de referencias resultantes después de la educación formal del médico basada en los estándares actuales de tratamiento de la osteoartritis.

Materiales y Métodos Usando un diseño cruzado, 22 MAPs evaluaron 2 rondas de 10 casos clínicos cada una, generando 440 encuentros clínicos simulados de pacientes con osteoartritis de cadera. En 220 encuentros simulados, el MAP decidió si una derivación quirúrgica era apropiada mediante el uso de la herramienta AAOS-AUC. En los otros 220 encuentros simulados, esa decisión se tomó utilizando el conocimiento adquirido después de la educación médica formal. Se comparó la tasa de derivaciones quirúrgicas generadas por ambas estrategias.

Resultados No hubo diferencia en la tasa de derivaciones quirúrgicas al comparar encuentros simulados utilizando la herramienta AAOS-AUC (57,3 %) y aquellos que utilizaron el juicio clínico después de la educación formal (62,7 %; p = 0,2). Tampoco se encontraron diferencias al comparar MAPs que usaron la herramienta AAOS-AUC durante su primera o segunda ronda de casos (60,7% versus 58,8%, respectivamente; p = 0,68)

Conclusión En manos de MAPs, la herramienta en línea AAOS-AUC funciona tan bien como la educación formal del médico durante el proceso de derivación quirúrgica para ATC. Es plausible considerar la AAOS-AUC una herramienta práctica de apoyo a la toma de decisiones para pacientes con artrosis de cadera evaluados en atención primaria.

Nivel de evidencia Nivel V.
Branding: too often overlooked in disruptive innovation and social purpose arenas
Authors: Aaker David
Published: May 2023

Branding is critical to disruptive innovation and social purpose programs, both strategic arenas of contemporary and future concern. Despite the progress that has been made in the last three decades, establishing branding as an imperative for business strategy, the strategic relevance and practical impact of branding for these strategic arenas is often still underappreciated, underevaluated and underused in practice. In this commentary, I explain why branding is critical for the success of disruptive innovations and societal programs while arguing that branding academics and practitioners must remain or again become more outspoken advocates of branding. We need to communicate the conceptual and practical power of branding to the thought leaders outside of marketing, many of whom are academics in other fields, and we ought to do more to convince executives and practitioners of the mission-critical role of branding beyond marketing.
Field Guide to the Reptiles of the Northern Territory
Authors: Jolly Chris , Schembri Brendan , Macdonald Stewart
Published: May 2023

A land of extremes, the Northern Territory’s arid deserts and monsoonal forests harbour some of Australia’s smallest and the world’s largest reptiles, as well as some of the world’s most venomous snakes.

Field Guide to the Reptiles of the Northern Territory is the first regional guide to the crocodiles, turtles, lizards and snakes of this megadiverse region. It presents introductions to order, family and genus; keys to family, genus and species; and species profiles, including descriptions, photos, distribution maps and notes on natural history. It features profiles for the 390 species that occur or may occur on the land and in the sea of the Northern Territory.

Extensively illustrated, this is an essential resource for wildlife enthusiasts and professional and amateur herpetologists.
A comparison of smoke modelling tools used to mitigate air quality impacts from prescribed burning
Authors: Johnson Megan M. , Garcia-Menendez Fernando
Published: May 2023

Background Prescribed fire is a land management tool used extensively across the United States. Owing to health and safety risks, smoke emitted by burns requires appropriate management. Smoke modelling tools are often used to mitigate air pollution impacts. However, direct comparisons of tools’ predictions are lacking. Aims We compared three tools commonly used to plan prescribed burning projects: the Simple Smoke Screening Tool, VSmoke and HYSPLIT. Methods We used each tool to model smoke dispersion from prescribed burns conducted by the North Carolina Division of Parks and Recreation over a year. We assessed similarity among the tools’ predicted smoke fields, areas of concern and potential population impacts. Key results The total smoke area predicted by the tools differs by thousands of square kilometres and, as such, spatial agreement was low. When translated into numbers of residents potentially exposed to smoke, tool estimates can vary by an order of magnitude. Conclusions Our analysis of an operational burning program suggests that the differences among the tools are significant and inconsistent. Implications While our analysis shows that improved and more consistent smoke modelling tools could better support land management, clear guidelines on how to apply their predictions are also necessary to obtain these benefits.
Giant worm-shaped ESCRT scaffolds surround actin-independent integrin clusters
Authors: Stempels Femmy C. , Jiang Muwei , Warner Harry M. , Moser Magda-Lena , Janssens Maaike H. , Maassen Sjors , Nelen Iris H. , de Boer Rinse , Jiemy William F. , Knight David , Selley Julian , O’Cualain Ronan , Baranov Maksim V. , Burgers Thomas C.Q. , Sansevrino Roberto , Milovanovic Dragomir , Heeringa Peter , Jones Matthew C. , Vlijm Rifka , ter Beest Martin , van den Bogaart Geert
Published: May 2023

Endosomal Sorting Complex Required for Transport (ESCRT) proteins can be transiently recruited to the plasma membrane for membrane repair and formation of extracellular vesicles. Here, we discovered micrometer-sized worm-shaped ESCRT structures that stably persist for multiple hours at the plasma membrane of macrophages, dendritic cells, and fibroblasts. These structures surround clusters of integrins and known cargoes of extracellular vesicles. The ESCRT structures are tightly connected to the cellular support and are left behind by the cells together with surrounding patches of membrane. The phospholipid composition is altered at the position of the ESCRT structures, and the actin cytoskeleton is locally degraded, which are hallmarks of membrane damage and extracellular vesicle formation. Disruption of actin polymerization increased the formation of the ESCRT structures and cell adhesion. The ESCRT structures were also present at plasma membrane contact sites with membrane-disrupting silica crystals. We propose that the ESCRT proteins are recruited to adhesion-induced membrane tears to induce extracellular shedding of the damaged membrane.
Internal ring waves in a three-layer fluid on a current with a constant vertical shear
Authors: Tseluiko D , Alharthi N S , Barros R , Khusnutdinova K R
Published: May 2023

Oceanic internal waves often have curvilinear fronts and propagate over vertically sheared currents. We present the first study of long weakly-nonlinear internal ring waves in a three-layer fluid in the presence of a horizontally uniform background current with a constant vertical shear. The leading order of this theory leads to the angular adjustment equation—a nonlinear first-order ordinary differential equation describing the dependence of the linear long-wave speed on its angle to the direction of the current. The compact ring waves, well studied in the absence of a current, correspond to the singular solution (envelope of the general solution) of this equation, and they can exist only under certain conditions. The constructed solutions reveal qualitative differences in the shapes of the wavefronts of the two baroclinic modes: the wavefront of the faster mode is elongated in the direction of the current, while the wavefront of the slower mode is squeezed. Moreover, depending on the vorticity strength, several different regimes have been identified. When the vertical shear is weak, part of the wavefront is able to propagate upstream, while when the shear is strong enough, the whole wavefront propagates downstream. A richer pattern of behaviour is observed for the slower mode. As the shear increases, singularities of the swallowtail-type may arise and, eventually, solutions with compact wavefronts crossing the downstream axis cease to exist. We show that the latter is related to the long-wave instability of the base flow. We obtain the cKdV-type amplitude equation and examine analytical expressions for its coefficients. Using this cKdV-type equation we numerically model the evolution of the waves for both modes. The initial stage of the evolution is in agreement with the leading-order predictions for the deformations of the wavefronts. Then, as the wavefronts expand, strong dispersive effects occur in the upstream direction. Moreover, when nonlinearity is enhanced, fission of waves is observed in the upstream part of the ring waves.
On the importance of excited state species in low pressure capacitively coupled plasma argon discharges
Authors: Wen De-Qi , Krek Janez , Gudmundsson Jon Tomas , Kawamura Emi , Lieberman Michael A , Zhang Peng , Verboncoeur John P
Published: May 2023

In the past three decades, first principles-based fully kinetic particle-in-cell Monte Carlo collision (PIC/MCC) simulations have been proven to be an important tool for the understanding of the physics of low pressure capacitive discharges. However, there is a long-standing issue that the plasma density determined by PIC/MCC simulations shows quantitative deviations from experimental measurements, even in argon discharges, indicating that certain physics may be missing in previous modeling of the low pressure radio frequency (rf) driven capacitive discharges. In this work, we report that the energetic electron-induced secondary electron emission (SEE) and excited state atoms play an important role in low pressure rf capacitive argon plasma discharges. The ion-induced secondary electrons are accelerated by the high sheath field to strike the opposite electrode and produce a considerable number of secondary electrons that lead to additional ionizing impacts and further increase of the plasma density. Importantly, the presence of excited state species even further enhances the plasma density via excited state neutral and resonant state photon-induced SEE on the electrode surface. The PIC/MCC simulation results show good agreement with the recent experimental measurements in the low pressure range (1–10 Pa) that is commonly used for etching in the semiconductor industry. At the highest pressure (20 Pa) and driving voltage amplitudes 250 and 350 V explored here, the plasma densities from PIC/MCC simulations considering excited state neutrals and resonant photon-induced SEE are quantitatively higher than observed in the experiments, requiring further investigation on high pressure discharges.
The effect of Ag doping on the structure, optical, and electronic properties of ZnO nanostructures deposited by atmospheric pressure MOCVD on Ag/Si substrates
Authors: Ievtushenko A , Dzhagan V , Khyzhun O , Baibara O , Bykov O , Zahornyi M , Yukhymchuk V , Valakh M , Zahn D R T , Naumenko K , Zaremba P , Zagorodnya S
Published: May 2023

Atmospheric pressure metal–organic chemical vapour deposition was used to synthesize Ag-containing ZnO nanostructures of different morphology on Si substrates coated by Ag. Ag from Ag/Si substrates and Ag from silver acetylacetonate after its decomposition were used as a catalyst for ZnO nanocrystal growth for deposition of ZnO nanostructures with different morphologies. We investigated the relation of the structural parameters and chemical composition probed by x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and Raman spectroscopy with the photoluminescence (PL) properties and electron–phonon coupling (EPC) reflected in the multi-phonon Raman spectra. The Raman and PL spectra were studied at different powers of the exciting laser radiation (P
exc). The spectral position and width of the phonon Raman peaks and the near bandgap PL band at low P
exc are supposed to be determined by the structural quality of the surfaces/boundaries of the crystallites. The intensity of the near-bandgap and defect-related PL and the magnitude of the EPC are additionally affected by the dopant concentration. Because of the large crystallite size (>30 nm, determined from XRD), the effects of phonon or electron confinement are negligible in these nanostructures. The behaviour of the position and width of phonon and PL bands with increasing P
exc indicates that the heat dissipation in the film, which is dependent on the nanostructure morphology and Ag content, plays an important role. In addition, the cytotoxicity of ZnO:Ag nanostructures was investigated by using monolayer cell cultures of epithelioid origin Madin-Darby bovine kidney and Madin-Darby canine kidney cells at a MTT assay revealing that the level of silver doping of ZnO nanostructures, their morphology, and geometric dimensions determine their toxic effects.
New approach to unimodular relativity
Authors: Tiwari S C
Published: May 2023

A thorough study and analysis on the conceptual foundations of unimodular gravity shows that this theory is essentially general relativity disguised as unimodular relativity in the literature. The main reason for this dilemma is accepting the Einsteinian paradigm: general relativistic framework, covariant divergence law for matter energy-momentum tensor, and cosmological constant as an integration constant, but introducing the artefact of unimodular description absent in Einstein’s work. A new approach is proposed in this paper in which pure unimodular relativity is defined in terms of equi-projective geodesics with the fundamental metric tensor having determinant unity and the geometric tensors constructed from them. Modification of covariant divergence law for the matter energy-momentum tensor is shown to have two new consequences. In the conventional unimodular gravity an effective cosmological term comprising of two variable scalar fields, namely, the unimodular geometric ambiguity and unimodular matter energy ambiguity, is proposed. A radical departure on the cosmological constant problem is possible assuming differing evolution of the two scalars: the Einstein equations emerge when the two ambiguities cancel each other. Secondly, in the case of pure unimodular relativity the gravitational field equations are proposed consistent with the unimodular space-time structure.
Propagation characteristics of dust density waves in an external magnetic field
Authors: Gogoi Niranjan , Das Nilakshi
Published: May 2023

Propagation of dust density waves (DDW) is theoretically investigated in a collisional plasma in the presence of an external magnetic field. The magnetic field is kept constant in a direction perpendicular to the direction of streaming ions, which is an important requirement for the self-excitation of these waves. Standard stability analysis is done to predict the conditions under which ion-drift instability may drive the DDW unstable. It is found that a minimum dust density is required to excite the wave. There exists a lower cut-off value of ion streaming velocity for the excitation of DDW which may change with the applied magnetic field and neutral gas pressure. The wave is found to behave complexly with the applied magnetic field and gets damped beyond a critical value. The results of this paper may be helpful in understanding the behavior of low-frequency dust modes as well as the background plasma both in laboratory and astrophysical environments.
Experimental study of electron cyclotron heating assisted start-up on J-TEXT
Authors: Zhang Junli , de Vries Peter C , Nagasaki Kazunobu , Xia Donghui , Jiang Wei , Yang Zhoujun , Cheng Zhifeng , Gao Li , Xu Xin , Wang Zhijiang , Wang Nengchao , Ding Yonghua , Chen Zhipeng , Chen Zhongyong , Pan Yuan
Published: May 2023

Second harmonic X-mode (X2 mode) electron cyclotron heating (ECH) assisted start-up has been studied experimentally on the J-TEXT device to determine the minimum ECH power requirements to assist breakdown and develop a better physical description of the process. Results indicate that the minimum toroidal electric field for a successful start-up on J-TEXT changed from

2.5

V

m

−
1

to

0.56

V

m

−
1

, and that injecting

300

k
W

of X2-mode ECH power can ensure robust breakdown. The critical ECH power for successful start-up was determined to be approximately

200

k
W

. At lower powers ECH was observed to cause ionization, but this did not necessarily result in successful start-up. The effects of varying ECH power, pulse-width and toroidal magnetic field on start-up were also investigated. Higher ECH power leads to quicker, stronger ionization and CIII emission, and is beneficial for burn-through. Higher pre-plasma density caused by high ECH power can decrease the required toroidal electric field for ohmic breakdown, while the enhanced CIII emission may not be good for start-up. The characteristics of the pre-plasma formed by ECH prior to application of the loop voltage were also studied. The toroidal magnetic field affects the initial location where pre-plasma forms and this also affected the subsequent tokamak start-up. The analysis of spatial density showed that the pre-plasma can radially develop at a velocity of

600

m

s

−
1

. Furthermore, it was found that injecting ECH power at the appropriate time with a low power of

150

k
W

can achieve similar pre-ionization results to the high-power case. The transition from ECH plasma to ohmic plasma suggests that the ECH assisted start-up modified the process of purely ohmic breakdown.
Study on Integrated Demand Response Strategy and System Coordination and Optimization of Park Integrated Energy System
Authors: Che Bin , Zhang Zelong , Yang Zhao , Zhang Weiqi
Published: May 2023

The need for flexibility in integrated energy systems is progressively becoming more demanding as these systems expand. Three types of demand response are introduced. An integrated demand response strategy is developed to address the situation based on an analysis based on the fundamental model of the Park Integrated Energy System. Additionally, the coordinated optimization model of the Park Integrated Energy System is created to minimize operational costs while considering a variety of restrictions.
Collaborative optimization method of the regional integrated energy system for energy cascade utilization
Authors: Fang Xin , Pan Yi , Yuan Xiaodong , Shi Mingming , Yang Jinggang , Sun Tiankui
Published: May 2023

Energy is an important resource, and its main reserves are obviously insufficient compared with consumption. The energy structure is mainly dominated by fossil energy. The pollution emissions from energy utilization are becoming more and more serious. The energy problem has seriously affected the development of new urbanization. This paper studies the optimal scheduling problem of typical urban integrated energy systems participating in different demand response methods. Based on the traditional power demand response model, the demand response model is constructed according to the equivalent thermal parameters. Its model can optimize the electricity and gas load curves and realize the balance of electricity, heat, and gas in an economical and environmentally friendly way. It can also reduce the total cost of the economic operation of the system and reduce the overall carbon emissions of the system. Through the optimization and regulation of multi-type “source-storage-load”, multi-time scale, and multi-objective joint for the distributed thermal power, the matching of thermal and electric hybrid energy and the peak and valley of the power grid can be realized.
Study on the Fitting Method of Power User Load Curve Under the Condition of Spot Operation
Authors: Du Xin , Min Rui , Liu Jian , Wang QiuHua , Zhang Lin
Published: May 2023

With the acceleration and deepening of the power market reform, the National Development and Reform Commission has issued power system reform documents to promote all industrial and commercial users to enter the power market. For the spot pilot area, the clearing and settlement time is required to be more accurate. Except for a few large industrial users, a wide range of small and medium-sized users and residents do not have the meter conditions for time-sharing measurement, and the investment in large-scale transformation of measuring equipment is huge, so the settlement basis must be obtained by fitting. This paper proposes a reverse derivation method of the user load curve. First, deducting the user curve with metering conditions from the load curve, and then calculating different types of user curves by adding weight coefficient fitting. At the same time, it proposes a method to deal with fitting deviation, which realizes the fitting of user curves without time-sharing meters, supports the needs of spot market settlement, and effectively promotes the entry of all industrial and commercial users into the market.
Research on Levitation Force Control of an Axial-flux Hybrid-Excitation Generator with PI-Based Torque Distribution
Authors: Chen Jiming , Xu Chongwang , Zhu Jingnan , Liu Jing
Published: May 2023

An asymmetric-primary axial-flux hybrid-excitation generator (APAFHG) has already been proposed to improve the starting performance of vertical axis wind turbines. However, the double-stator single-rotor structure causes a problem: different torque proportions create different rotor maglev forces, which will cause fluctuation and negatively impact the rotor bearing and even the operation of the wind power generation system. Therefore, a mathematical model considering the double-stator single-rotor structure and a proportional integral-based torque control strategy considering double-stator distribution are proposed in this paper to help APAFHG offer a good starting performance in vertical-axis wind power generation system and to stabilize maglev force generated by double-stator quadrature axis current simultaneously. Finally, the cooperation control of the maglev force and torque distribution is realized in MATLAB/Simulink, and the rotor maglev force will be relatively stable despite mechanical torque changes, which is a basis for the wind turbine to stably operate as the wind constantly fluctuates in vertical axis wind power system.
The Virtual Data-sampling Method Based on Optimal DBN for High-Scale Distributed Photovoltaic Power Generation
Authors: Zhang Hua , Li Shilong , Ding Lijie , Liu Chang , Xie Tianxiang , Huang Yan
Published: May 2023

In a distribution power grid with a high proportion of distributed photovoltaic (DP) connections, the real-time acquisition of the distributed photovoltaic power generation data is a costly and heavy task. In this paper, a virtual data sampling method based on Deep Belief Network (DBN) combined with a Second-order oscillating-firefly algorithm (SOO-FA) is proposed. It enables virtual data sampling from all distributed PV plants in a region where only one distributed PV plant has a complete data-sampling device and the other distributed PV plants have less expensive current sampling terminals. The firefly algorithm is utilized to continuously adjust and optimize the weights of the deep belief network, and the optimal DBN model is used to carry out the virtual collection of the power output data of the distributed PV equipment within the region. Finally, the proposed method has high accuracy for the PV output power by 100 distributed PV devices in the regional range in the simulation section.
Research on RIS-assisted PMU Short Packet Communication for Active Distribution Networks
Authors: Han Xiao , Li Shuanghou , Wang Dong , Liu Jinlong , Yu Jiao , Zhang Yang
Published: May 2023

Phasor measurement unit (PMU) has been widely applied in power grids. For these applications, there is usually a high requirement for data transmission delay and reliability; therefore, short data packets are often used for transmission. Therefore, a downlink communication model for reconfigurable intelligent surface (RIS) assisted multi-PMU is proposed in the paper. We propose a joint optimization problem to maximize the total achievable system rate. Finally, an alternate iterative algorithm based on SCA is proposed. The results show that the proposed algorithm can effectively improve the sum rate.
A positive and negative sequence current measuring device and method based on an electric energy metering platform
Authors: Xia Wu , Liu Youqiang , Tian Xianggui , Qin Xiankun , Shen Diqiu
Published: May 2023

At present, the current positive and negative sequence extraction methods are all based on high-performance analog-to-digital converters and need high-performance microprocessors. Or the negative sequence current measurement circuit is constructed using an analog operational amplifier, and the phase shifting method is used to achieve the measurement purpose. The above methods need to be implemented by chips with high computing power. They even need to build an additional positive sequence current measurement circuit, which makes the circuit more complex and cost-effective. This paper proposes a positive and negative sequence current measuring device and method based on the electric energy metering platform. Through the external phase, the current access device is to be measured using the power measurement value formed by the voltage channel, current channel, and multi-function measurement channel corresponding to the single-phase metering chip of the measurement unit, the included angle of phase current can be calculated, thus realizing the calculation of positive and negative sequence current. It avoids using high-performance analog-to-digital converters, effective value, frequency tracking, phase measurement, and other complex algorithms, reduces the computational requirements for MCU master chip, and reduces the development difficulty and cost.
Vibration Fundamental Frequency Amplitude Prediction of Electric Transformer by Proposed Hybrid Artificial Bee Colony Method
Authors: Wang Jianping , Li Wanlin
Published: May 2023

Existing research express by processing about the vibration signal of electric transformer cover, the corresponding fundamental frequency amplitude can be obtained, which can be used to dig the specific operation state of the electric transformer. For accurately predicting the amplitude at the fundamental frequency about cover vibration signal of electric transformer, a proposed method based on artificial bee colony is designed. But the basic artificial colony method has some defects, such as slow tracking speed and poor feature description ability. Therefore, in view of the shortcomings of the existing ABC based method, the proposed artificial bee colony method is designed, where an adversarial learning mechanism and optimizing each specific search formula is employed. The proposed ABC method improves the prediction accuracy of electric transformer cover vibration signal’s fundamental frequency amplitude. The sepcific results of experimental introduce the effectiveness of the proposed ABC method.
Analysis of magnetic field characteristics and no-load losses of three-dimensional wound core transformer
Authors: Li Min , Yao Wei , Gao Xin , Liu Cong
Published: May 2023

Three-dimensionally wound core transformers (TWCTs) are widely used because of their low iron loss. This paper investigates the triangularly arranged TWCT core structure and a conventional planar laminated core transformer’s flat “E” core structure (PLCT). First, the magnetic field structures of the two transformers are analyzed using the equivalent magnetic circuit method to study the symmetry of the three-phase reluctance. Then, using the finite element method, a three-dimensional simulation model was built to analyze the no-load performance of TWCT and PLCT with the same dimensional parameters and the same core material. The no-load flux of each coil, the induced voltage on the secondary side, and the no-load iron loss of the core are analyzed. The analysis results show that TWCT has a 7.48% lower no-load loss than PLCT, which verifies the superiority of TWCT in terms of no-load loss.
Research on the Influence of Wind Power Access on Voltage Stability of Distribution Network
Authors: Gao Chen , Feng Ruming , Wang Yuqiang , Yan Xu , Wu Xiaoqian , Han Tao , Li Qi
Published: May 2023

This paper proposes a voltage stability index suitable for distributed generation and distribution network which is derived by using the relationship between power balance and voltage balance and the impact of wind power access location, access capacity, and fault on the voltage stability. The results show that the shorter the length and the larger the wind power capacity, the more obvious its role in supporting the distribution network voltage. But the greater the negative impact of wind power’s instability on the distribution network voltage, the above factors must be comprehensively considered in network planning.
Analysis and Research on Lightning Inrush Wave Overvoltage in EHV GIS Substation transformation project
Authors: Feng Ruming , Zhao Lei , Che Chuanqiang , Wang Qiong , Tianyu  , Zhao Jun , Wang Lei
Published: May 2023

When lightning intrudes into the over-voltage in the 500 kV substation, the lightning wave will be introduced into the substation along the line, which will seriously affect the insulation level of the equipment. In this paper, firstly, the working principle, characteristics, and lightning current simulation of the ZnO arrester are described. Then, the electromagnetic transient program (EMTP-ATP) used in a 500 kV GIS substation carried out the simulation research to the lightning over-voltage, specifically studied the lightning protection effect of metal oxide arrester, compared the lightning over-voltage under the different lightning locations and operation mode, and calculated the 500kV GIS Substation under the single in single out operation mode, 500kV. The influence of different positions of lightning arresters in GIS on the magnitude of lightning over-voltage and the lightning over-voltage on the substation equipment in GIS is also described.
Transmission Line Audible Noise Prediction Based on CNN-BiLSTM-Attention Method
Authors: Huang Yuehua , Zhang Zihao , Chen Qing , Zhang Lei , Zhang Jiangong , Lan Xinsheng
Published: May 2023

High-voltage transmission lines’ audible noise parameters are impacted by a variety of multidimensional elements. in order to better the accuracy of audible noise prediction and effectively utilize the time-series properties in the observed audible noise data. In this paper, we propose a combined model of a convolutional neural network (CNN) and a bidirectional long and short-term memory network (BiLSTM)-based attention mechanism based on feature filtering for transmission line audible noise prediction. Firstly, using the transmission line real-world audible noise data as the dataset, the multidimensional factor time series parameters are optimally filtered, and high correlation feature vectors are extracted by using CNN. Secondly, the extracted feature vectors are fed into the BiLSTM for training and prediction, and the prediction performance is further improved by introducing an attention mechanism at the BiLSTM end so that the model focuses on learning more important data features. Finally, the prediction analysis using actual recorded audible noise data from a 500 kV AC transmission line in Sichuan Province demonstrates that the combined CNN-BiLSTM-Attention model suggested in this paper has a higher prediction accuracy than the BiLSTM, CNN-BiLSTM, and BiLSTM-Attention models.
Design and Test of Control System of RF Ion Source Test Platform Based on Industrial PLC
Authors: Duan Lian , Liu Zhimin , Li Yibin , Song Shihua
Published: May 2023

Combined with the experimental operation requirements of the radio frequency ion source test platform, a set of the control system is designed with S7-1200 series PLC which is based on TIA Portal and WinCC configuration software. It realizes the monitoring and management of the RF ion source performance test experiment. In order to visualize the operation of the test platform, a fully graphical monitoring interface is designed. And the system has functions such as timing control, real-time status monitoring, parameter setting, data acquisition and recording, historical data query, and alarm recording. After experimental testing, the system meets the control requirements of the ion source performance testing platform and is of great significance for the fault diagnosis and safe operation of the test platform system.
Electric-Gas Integrated Energy Dispatch Based on Multi-ob jective Gray Wolf Algorithm
Authors: Tang Guosheng , Zhao Bingyan
Published: May 2023

With the development of the energy Internet, the integrated energy network of electricity-gas interconnection has become an important research object of energy optimization. To improve the energy absorption capacity and energy utilization efficiency of renewable energy in a regional integrated energy network, a comprehensive energy multi-objective optimization model containing the power to gas (P2G) is proposed in this paper. The model considers the two objectives of pollutant emission and system operating cost, and the model is solved by the Multi-objective Grey Wolf Optimizer (MOGWO). The example shows that a P2G device can improve energy efficiency