bluuebunny/crossref_metadata_2025 huggingface dataset:
Interfacial negative biexcitons in a monolayer WS2/InGaN quantum dots heterostructure
Authors: Jin Zijing , Li Baikui , Zhao Chunyu , Zhou Chengjie , Wang Jiannong
Published: September 2024

In this work, we fabricated a Van der Waals heterostructure of monolayer (ML) WS2 and InGaN quantum dots (QDs). This heterostructure is divided into coupled and uncoupled regions based on the thickness of the inserted hBN layer. Upon measuring its PL spectra, we identified an interfacial negative biexciton, which consists of a trion in ML WS2 and an exciton in QDs, in the coupled region. This interfacial negative biexciton features the negative charge of the trion and the quantum confinement of QDs, with its relative intensity showing a strong dependence on the excitation photon energy and featuring a significant threshold. Our work highlights the effective coupling within the mixed-dimensional heterostructure, offering new prospects for the study of many-body physics.
Nonequilibrium relaxation of soft responsive colloids
Authors: López-Molina José , Groh Sebastien , Dzubiella Joachim , Moncho-Jordá Arturo
Published: September 2024

Stimuli-responsive macromolecules display large conformational changes during their dynamics, sometimes switching between states. Such a multi-stability is useful for the development of soft functional materials. Here, we introduce a mean-field dynamical density functional theory for a model of responsive colloids to study the nonequilibrium dynamics of a colloidal dispersion in time-dependent external fields, with a focus on the coupling of translational and conformational dynamics during their relaxation. Specifically, we consider soft Gaussian particles with a bimodal size distribution between two confining walls with time-dependent (switching-on and off) external gravitational and osmotic fields. We find a rich relaxation behavior of the systems in excellent agreement with particle-based Brownian dynamics computer simulations. In particular, we find time-asymmetric relaxations of integrated observables (wall pressures, mean size, and liquid center-of-mass) for activation/deactivation of external potentials, respectively, which are tunable by the ratio of translational and conformational diffusion time scales. Our work thus paves the way for studying the nonequilibrium relaxation dynamics of complex soft matter with multiple degrees of freedom and hierarchical relaxations.
Interplay of coulomb and exciton–phonon coupling controls singlet fission dynamics in two pentacene polymorphs
Authors: Arias Dylan H. , Cohen Galit , Damrauer Niels H. , Refaely-Abramson Sivan , Johnson Justin C.
Published: September 2024

Pentacene is an important model organic semiconductor in both the singlet exciton fission (SF) and organic electronics communities. We have investigated the effect of changing crystal structure on the SF process, generating multiple triplet excitons from an initial singlet exciton, and subsequent triplet recombination. Unlike for similar organic semiconductors that have strong SF sensitive to polymorphism, we find almost no quantitative difference between the kinetics of triplet pair (TT) formation in the two dominant polymorphs of pentacene. Both pairwise dimer coupling and momentum-space crystal models predict much faster TT formation from the bright singlet excited state of the Bulk vs ThinFilm polymorph, contrasting with the experiment. GW and Bethe–Salpeter equation calculations, including exciton–phonon coupling, reveal that ultrafast phonon-driven transitions in the ThinFilm polymorph compensate the intrinsically slower purely Coulomb-mediated TT formation channel, rationalizing the similarity in observed rates. Taking into account the influence of subtle structural distinctions on both the direct and phonon-mediated SF pathways reveals a predictive capability to these methods, expected to be applicable to a wide variety of molecular crystals.
Comparison of curvilinear coordinates within vibrational structure calculations based on automatically generated potential energy surfaces
Authors: Schneider Moritz , Rauhut Guntram
Published: September 2024

For floppy molecules showing internal rotations and/or large amplitude motions, curvilinear internal coordinates are known to be superior to rectilinear normal coordinates within vibrational structure calculations. Due to the myriad definitions of internal coordinates, automated and efficient potential energy surface generators necessitate a high degree of flexibility, supporting the properties arising from these coordinates. Within this work, an approach to deal with these challenges is presented, including key elements, such as the selection of appropriate fit functions, the exploitation of symmetry, the positioning of grid points, or elongation limits for different coordinates. These elements are tested for five definitions of curvilinear coordinates, with three of them being generated in an automated manner. Calculations for semi-rigid molecules, namely H2O, H2CO, CH2F2, and H2CNH, demonstrate the general functionality of the implemented algorithms. Additional calculations for the HOPO molecule highlight the benefits of these curvilinear coordinates for systems with large amplitude motions. This new implementation allowed us to compare the performance of these different coordinate systems with respect to the convergence of the underlying expansion of the potential energy surface and subsequent vibrational configuration interaction calculations.
Numerical analysis of the complete active-space extended Koopmans’s theorem
Authors: Hemmati Reza , Mostafanejad Mohammad , Ortiz J. V.
Published: September 2024

We investigate the numerical accuracy of the extended Koopmans’s theorem (EKT) in reproducing the full configuration interaction (FCI) and complete active-space configuration interaction (CAS-CI) ionization energies (IEs) of atomic and molecular systems calculated as the difference between the energies of N and (N − 1) electron states. In particular, we study the convergence of the EKT IEs to their exact values as the basis set and the active space sizes vary. We find that the first FCI EKT IEs approach their exact counterparts as the basis set size increases. However, increasing the basis set or the active space sizes does not always lead to more accurate CAS-CI EKT IEs. Our investigation supports the observation of Davidson et al. [J. Chem. Phys. 155, 051102 (2021)] that the FCI EKT IEs can be systematically improved with arbitrary numerical accuracy by supplementing the basis set with diffuse functions of appropriate symmetry, which allow the detached electron to travel far away from the reference system. By changing the exponent and the center of the diffuse functions, our results delineate a complex pattern for the CAS-CI EKT IE of LiH, which can be important for the spectroscopic studies of small molecules.
Two-dimensional ferroelastic semiconductors InXY (X = S, Se; Y = Cl, Br, I): Promising candidates for photocatalytic water splitting with tunable electronic anisotropy
Authors: Pan Lu , Wan Yu-Lu , Hu Cui-E , Zeng Zhao-Yi , Geng Hua-Yun , Chen Xiang-Rong
Published: September 2024

We have identified a class of two-dimensional ferroelastic monolayers, denoted as InXY (where X = S, Se; Y = Cl, Br, I), through first-principles calculations. The dynamic, thermal, and mechanical stabilities of these InXY monolayers are validated by phonon dispersion spectra, AIMD calculations, and elastic constants, respectively. These monolayers exhibit semiconducting behavior with bandgaps ranging from 1.94 to 2.85 eV and possess excellent ferroelasticity with strong ferroelastic signals and moderate ferroelastic switching barriers. Notably, the band edge positions of InSBr and InSI monolayers are observed to stride the water redox potentials at pH = 0, indicating their potential as photocatalysts for water splitting in acidic environments. We also explored the effects of biaxial strain on the band edge alignments and photocatalytic performance of these monolayers. Moreover, the InXY monolayers exhibit excellent anisotropic optical absorption across the visible to ultraviolet regions, along with high anisotropic carrier transport. The coupling of ferroelastic and anisotropic properties in these monolayers offers promising opportunities for designing controllable electronic devices, thereby expanding their potential applications in multifunctional materials. Our findings reveal that the InXY monolayers are promising candidates for efficient photocatalytic water splitting and controllable optoelectronic applications.
Charting the future of high forest low deforestation jurisdictions
Authors: Teo Hoong Chen , Sarira Tasya Vadya , Tan Audrey R. P. , Cheng Yanyan , Koh Lian Pin
Published: September 2024

High forest low deforestation jurisdictions (HFLDs) contain many of the world’s last intact forests with historically low deforestation. Since carbon financing typically uses historical deforestation rates as baselines, HFLDs facing the prospect of future threats may receive insufficient incentives to be protected. We found that from 2002 to 2020, HFLDs (
n
= 310) experienced 44% higher deforestation rates than their historical baselines, and 60 HFLDs underwent periods of high deforestation (deforestation rate > 0.501%) at 0.983 ± 0.649% (mean ± SD)—a rate 7.5 times higher than the 10-y historical baseline of all HFLDs. For HFLDs to receive sufficient carbon finance requires baselines that can better reflect future deforestation trajectories of HFLDs. Using an empirical multifactorial model, we show that most contemporary HFLDs are expected to undergo higher deforestation from 2020 to 2038 than their historical baselines, with 72 HFLDs likely (>66% probability) to undergo high deforestation. Over the next 18 y, HFLDs are expected to lose 2.16 Mha y
−1
of forests corresponding to 585 ± 74 MtCO
2
e y
−1
(mean ± SE) of emissions. Efforts to protect HFLD forests from future threats will be crucial. In particular, improving baselining methods is key to ensuring that sufficient financing can flow to HFLDs to prevent deforestation.
Inhibition of colorectal cancer in Alzheimer’s disease is mediated by gut microbiota via induction of inflammatory tolerance
Authors: Zhang Nan , Zhang Rui , Jiang Lei , Gao Zhaoyu , Xia Wenzhen , Ma Xiaoying , Qin Yushi , Zhang Di , Li Jiazheng , Tian Pei , Zhang Qi , Wang Wanchang , Zhang Kaixia , Xu Shan , Zhao Na , Xu Shunjiang
Published: September 2024

Epidemiological studies have revealed an inverse relationship between the incidence of Alzheimer’s disease (AD) and various cancers, including colorectal cancer (CRC). We aimed to determine whether the incidence of CRC is reduced in AD-like mice and whether gut microbiota confers resistance to tumorigenesis through inducing inflammatory tolerance using 16S ribosomal RNA gene sequencing and fecal microbiota transplantation (FMT). AD-like mice experienced a significantly decreased incidence of CRC tumorigenesis induced by azoxymethane–dextran sodium sulfate as evidenced by suppressed intestinal inflammation compared with control mice. However, FMT from age-matched control mice reversed the inhibitory effects on the tumorigenesis of CRC and inflammatory response in AD-like mice. The key bacterial genera in gut microbiota, including
Prevotella
, were increased in both the AD-like mice and in patients with amnestic mild cognitive impairment (aMCI) but were decreased in patients with CRC. Pretreatment with low-dose
Prevotella
-derived lipopolysaccharides (LPS) induced inflammatory tolerance both in vivo and in vitro and inhibited CRC tumorigenesis in mice. Imbalanced gut microbiota increased intestinal barrier permeability, which facilitated LPS absorption from the gut into the blood, causing cognitive decline in AD-like mice and patients with aMCI. These data reveal that intestinal
Prevotella
-derived LPS exerts a resistant effect to CRC tumorigenesis via inducing inflammatory tolerance in the presence of AD. These findings provide biological evidence demonstrating the inverse relationship between the incidence of AD and CRC.
Single-cell analysis via manifold fitting: A framework for RNA clustering and beyond
Authors: Yao Zhigang , Li Bingjie , Lu Yukun , Yau Shing-Tung
Published: September 2024

Single-cell RNA sequencing (scRNA-seq) data, susceptible to noise arising from biological variability and technical errors, can distort gene expression analysis and impact cell similarity assessments, particularly in heterogeneous populations. Current methods, including deep learning approaches, often struggle to accurately characterize cell relationships due to this inherent noise. To address these challenges, we introduce scAMF (Single-cell Analysis via Manifold Fitting), a framework designed to enhance clustering accuracy and data visualization in scRNA-seq studies. At the heart of scAMF lies the manifold fitting module, which effectively denoises scRNA-seq data by unfolding their distribution in the ambient space. This unfolding aligns the gene expression vector of each cell more closely with its underlying structure, bringing it spatially closer to other cells of the same cell type. To comprehensively assess the impact of scAMF, we compile a collection of 25 publicly available scRNA-seq datasets spanning various sequencing platforms, species, and organ types, forming an extensive RNA data bank. In our comparative studies, benchmarking scAMF against existing scRNA-seq analysis algorithms in this data bank, we consistently observe that scAMF outperforms in terms of clustering efficiency and data visualization clarity. Further experimental analysis reveals that this enhanced performance stems from scAMF’s ability to improve the spatial distribution of the data and capture class-consistent neighborhoods. These findings underscore the promising application potential of manifold fitting as a tool in scRNA-seq analysis, signaling a significant enhancement in the precision and reliability of data interpretation in this critical field of study.
Qki5 safeguards spinal motor neuron function by defining the motor neuron-specific transcriptome via pre-mRNA processing
Authors: Hayakawa-Yano Yoshika , Furukawa Takako , Matsuo Tsuyoshi , Ogasawara Takahisa , Nogami Masahiro , Yokoyama Kazumasa , Yugami Masato , Shinozaki Munehisa , Nakamoto Chihiro , Sakimura Kenji , Koyama Akihide , Ogi Kazuhiro , Onodera Osamu , Takebayashi Hirohide , Okano Hideyuki , Yano Masato
Published: September 2024

Many RNA-binding proteins (RBPs) are linked to the dysregulation of RNA metabolism in motor neuron diseases (MNDs). However, the molecular mechanisms underlying MN vulnerability have yet to be elucidated. Here, we found that such an RBP, Quaking5 (Qki5), contributes to formation of the MN-specific transcriptome profile, termed “MN-ness,” through the posttranscriptional network and maintenance of the mature MNs. Immunohistochemical analysis and single-cell RNA sequencing (scRNA-seq) revealed that Qki5 is predominantly expressed in MNs, but not in other neuronal populations of the spinal cord. Furthermore, comprehensive RNA sequencing (RNA-seq) analyses revealed that Qki5-dependent RNA regulation plays a pivotal role in generating the MN-specific transcriptome through pre-messenger ribonucleic acid (mRNA) splicing for the synapse-related molecules and c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) signaling pathways. Indeed, MN-specific ablation of the Qki5 caused neurodegeneration in postnatal mice and loss of Qki5 function resulted in the aberrant activation of stress-responsive JNK/SAPK pathway both in vitro and in vivo. These data suggested that Qki5 plays a crucial biological role in RNA regulation and safeguarding of MNs and might be associated with pathogenesis of MNDs.
Perpendicular crossing chains enable high mobility in a noncrystalline conjugated polymer
Authors: Coker Jack F. , Moro Stefania , Gertsen Anders S. , Shi Xingyuan , Pearce Drew , van der Schelling Martin P. , Xu Yucheng , Zhang Weimin , Andreasen Jens W. , Snyder Chad R. , Richter Lee J. , Bird Matthew J. , McCulloch Iain , Costantini Giovanni , Frost Jarvist M. , Nelson Jenny
Published: September 2024

The nature of interchain π-system contacts, and their relationship to hole transport, are elucidated for the high-mobility, noncrystalline conjugated polymer C16-IDTBT by the application of scanning tunneling microscopy, molecular dynamics, and quantum chemical calculations. The microstructure is shown to favor an unusual packing motif in which paired chains cross-over one another at near-perpendicular angles. By linking to mesoscale microstructural features, revealed by coarse-grained molecular dynamics and previous studies, and performing simulations of charge transport, it is demonstrated that the high mobility of C16-IDTBT can be explained by the promotion of a highly interconnected transport network, stemming from the adoption of perpendicular contacts at the nanoscale, in combination with fast intrachain transport.
Peer conformity and competition shape how business managers evaluate withdrawals from Russia amid the Ukraine War
Authors: Davis Christina L. , Li Jialu , Miyano Sayumi
Published: September 2024

States have long used economic sanctions in response to violations of international law as a strategy to restore order. Increasingly, firms also reject doing business with violators. In response to the war in Ukraine, hundreds of multinational corporations voluntarily withdrew from Russia, even when policymakers were still debating the extent of sanctions. How did firm managers evaluate whether to withdraw from the Russian market? Using a survey experiment with Japanese firm managers conducted three months after the Russian invasion of Ukraine in 2022, we explore how peer effects—information on what other firms are doing in response to the crisis—influence support for withdrawal of business activity with Russia. Our findings show that information about withdrawal by other firms from a diverse set of countries promotes peer conformity that increases support. In contrast, information about ongoing business with Russia by Chinese firms fosters competition that reduces support. Market exposure moderates these reactions, although the concern about peer behavior does not appear to be driven by a reputation mechanism. Our research provides insight into how business actors perceive the strategic interplay of peer influence and market dynamics in the context of geopolitical conflicts.
The effects of instruction on students’ argumentative scientific writing in a Basque medium of instruction
setting
Authors: Garro Larrañaga Eneritz , Antón Eneko , Arias-Hermoso Roberto , Carmona Unai
Published: September 2024

The present quasi-experimental study explores the effects of instruction on secondary students’ scientific
argumentative writing in a Basque medium of instruction program. Secondary students (N = 105) completed written
tasks before and after a unit on energy in their science class as part of this investigation. The experimental group
(n = 61) additionally took part in three, one-hour sessions focused on scientific argumentation via
instruction in cognitive discourse functions (Dalton-Puffer, 2013), while the control
group (n = 44) completed the unit on energy without the additional instruction on argumentation. The final corpus
of 210 texts was analysed using Toulmin’s Argumentation Pattern (1958). ANOVAs showed
that the experimental group’s use of argumentation strategies increased significantly, while the control group’s use of such
strategies did not increase. Thus, the results show that instruction on argumentation helps students to write better argumentative
compositions. These findings suggest that instruction in the use of Cognitive Discourse Functions allows for academic language
learning in bilingual education contexts. The pedagogical implications and future research directions of this study’s findings are
discussed.
One Health Approach Necessity in the Control of Highly Pathogenic Avian Influenza: An Integrated Analysis of Decision Makers’ Perspectives in Ivory Coast, Using Peter Checkland’s Soft System Methodology
Authors: Keita Ibrahima Mamby , Seck Rosalie Martine Ndew , Kouakou Christophe Yao , Ouattara Douyeri Thierry , Leyens Stephane , Irabor Thomas-Julian , Yameogo Peegdsom Simplice Assomption , De Backer Caroline , Antoine-Moussiaux Nicolas , Bonfoh Bassirou , Tiembre Isaac , Kallo Vessaly
Published: September 2024

The control of highly pathogenic avian influenza (HPAI) requires an integrated strategy. In Ivory Coast, it is decentralized and included in the health policy (as all tools, including SOPs, for managing disease prevention and control) but would lack a common vision and stable bridges for intersectoral exchanges and major health challenges joint planning. Thus the need to identify levers for action through the key sectoral decision makers’ perspectives in integrated HPAI control. A cross-sectional retrospective qualitative study, respecting ethical considerations, was carried out in May 2023 with national decision makers from the human, animal, environmental and community health sectors in Ivory Coast. Purposive sampling was guided by seven respondents based on the saturation principle. An open-ended, semi-structured interview grid based on the CATWOE components (
C
: Clients,
A
: Actors,
T
: Transformation process,
W
: Weltranschauung,
O
: Owners,
E
: Environment; Smyth D. and Checkland P. en 1975) were used to analyse the surveyed decision makers’ perspectives, using QDA
Miner4Lite
software. Findings showed four emerging perspectives, depending on the decision makers’ profile: (i) Veterinarians advocated a world better prepared to deal with HPAI, with simulation exercises (as one of the four components of the International Health Regulations monitoring framework to enable the lessons learned from a simulated public health event that can be capitalized on while strengthening the response system), joint investigations and training, creation of reactive and autonomous regional centres with enhanced technical facilities; (ii) Poultry industry (private sector) is also moving in the same direction, with the idea of common funds pre-mobilized through poultry farmer contributions to facilitate future compensation; (iii) Physicians prioritized the cross-sector sharing of digitized information in real time, the mutualization of resources and the integration of existing surveillance networks; and (iv) Environmentalists were keen to integrate aspects of other key sectors into their sectoral monitoring tools in order to be more alert and proactive in an ecological dynamic.

Information

© The Authors 2024
Ultraviolet finite resummation of perturbative quantum gravity
Authors: Morris Tim R
Published: September 2024

If the metric is chosen to depend exponentially on the conformal factor, and if one works in a gauge where the conformal factor has the wrong sign propagator, perturbative quantum gravity corrections can be partially resummed into a series of terms each of which is ultraviolet finite. These new terms however are not perturbative in some small parameter, and are not individually BRST invariant, or background diffeomorphism invariant. With appropriate parametrisation, the finiteness property holds true also for a full phenomenologically relevant theory of quantum gravity coupled to (beyond the standard model) matter fields, provided massive tadpole corrections are set to zero by a trivial renormalisation.
Lipschitz stability of an inverse conductivity problem with two Cauchy data pairs
Authors: Hanke Martin
Published: September 2024

In 1996 Seo proved that two appropriate pairs of current and voltage data measured on the surface of a planar homogeneous object are sufficient to determine a conductive polygonal inclusion with known deviating conductivity. Here we show that the corresponding linearized forward map is injective, and from this we deduce Lipschitz stability of the solution of the original nonlinear inverse problem. We also treat the case of an insulating polygonal inclusion, in which case a single pair of Cauchy data is already sufficient for the same purpose.
Interdigitated resonator based frequency selective rasorber with high selectivity
Authors: Huang Xiaojun , Li Ke , Hou Wei , Wang Yanpei , Ma Yutao
Published: September 2024

This paper investigates a highly selective frequency selective rasorber (FSR) utilizing interdigitated resonators, characterized by a passband exhibiting low insertion loss (IL) and the introduction of a second-order passband response in the lossless layer enhances selectivity on both sides of the passband. The lossy unit is implemented by inserting interdigitated resonators on an octagonal ring loaded with lumped resistors, while the lossless layer is constructed with a five-layer structure. Simulation results demonstrate a low IL value of 0.78 dB at 3.5 GHz. At vertical incidence, the S
21>−3 dB bandwidth ranges from 3.41 to 3.67 GHz, and the S
11<−10 dB range spans from 2.2 to 8.2 GHz, obtaining two absorption bands on either side of the passband, with absorption rates exceeding 80%. The operating frequency bands are 1.95–3.27 GHz and 3.8–8.4 GHz. The designed FSR exhibits polarization insensitive. To validate simulation results, a prototype FSR was fabricated and tested, with experimental data aligning with simulation results.
A novel unsupervised adaptive density-based clustering filter for remaining useful life prediction of bearings
Authors: Wang Wei , Zhou Gongbo , He Zhenzhi , Zhou Ping , Ma Guoqing , Yan Xiaodong , Ma Tianbing
Published: September 2024

Constructing the health indicator (HI) and predicting the remaining useful life (RUL) are essential steps in bearing health management. Some prediction methods depend on prior information about HIs, especially when these indicators are generated by deep learning models. However, acquiring such prior information can be challenging in practical applications. This paper introduces a novel unsupervised adaptive density-based clustering filter (UADCF) for RUL prediction of bearings, which operates without the need for prior knowledge. Firstly, a post-hoc interpretation HI model (PIHIM) is proposed to characterize the deep learning constructed HIs from the perspective of what the deep learning has done. Then, leveraging the classical density-based clustering algorithm, we introduce the UADCF for unsupervised estimation of model parameters, which can dynamically adjust density parameters based on the current conditions. Finally, we develop a prediction framework combining PIHIM and UADCF, enabling unsupervised RUL prediction of bearings. The experimental studies validate the effectiveness of the proposed method.
Speed harmonic suppression of PMSM and its application in ball screw vibration suppression
Authors: Wu Zhaoqian , Guo Wang , Liu Zhenhua , Jiang Canyang , Jiang Fei , Zhang Shaohui
Published: September 2024

The speed ripple of surface-mounted permanent magnet synchronous motor (SPMSM) causes vibration of the ball screw, which degrades the accuracy and stability of the ball screw system. The harmonic injection method can suppress the speed ripple by decreasing the speed harmonic of SPMSM. When the speed ripple is suppressed, the vibration of the ball screw is also reduced. However, large amount of calculation, complex parameter adjustment, and long suppression time limit its performance in suppressing vibration of ball screw. Therefore, in this paper, we propose a speed harmonic suppression method based on the online measurement of the transfer function from inject voltage harmonic to speed harmonic. In the proposed method, the transfer function is measured after the motor reaches a stable operating condition. And then, the designed speed harmonic controller parameters are set according to the measurement results. Compared with the existing method, the method based on online measurement has less calculation, simple parameter adjustment, fast suppression speed, and good performance in suppressing the vibration of ball screw. Experimental verifications are carried out in the forward and backward condition of the ball screw.
Study on phase-locked out-of-step fault characteristic analysis and protection of VSPSU
Authors: Lu Qinghui , Wang Xuefang , Qiao Jian , He Rufei , Ma Yiming , Yin Xianggen , Peng Yumin , Wang Wenhui
Published: September 2024

The variable-speed pumped storage unit (VSPSU) adopts flexible three-phase AC excitation, and the control dominant characteristics of the equipment are significant, which deeply affects the out-of-step (OOS) fault law and stability mechanism of VSPSU. Aiming at the OOS fault of VSPSU, this paper first defines the power angle of VSPSU and analyzes the influence of a phase-locked loop on the power angle stability of the unit. Then, the fault characteristics of the power angle instability of VSPSU are further studied. It is found that the traditional lens impedance protection scheme based on measuring the number of sliding poles has the problem that the phase-locked OOS oscillation cannot be responded to or the response is not timely. Combined with the research on the fault characteristics of power angle instability of VSPSU, an OOS protection method based on a bilateral annular blocker is proposed. The simulation results show that the proposed protection method can quickly and accurately reflect the phase-locked OOS fault of VSPSU, and meet the requirements of VSPSU for the reliability of OOS protection.
Capacity optimization configuration of multi-source independent microgrids based on TLC-GOLD-GWO algorithm
Authors: Cao Yalan , Zhang Xiaohong , Shen Zuyang
Published: September 2024

To guarantee the economic efficiency and reliability of standalone microgrids, this paper introduces an enhanced Grey Wolf optimization algorithm (GWO) [1] that leverages chaos mapping techniques, nonlinear convergence factor, and golden operator for solving multi-source capacity allocation problems. Taking the reliability of the power supply as a significant constraint, an optimization model is constructed with the minimization of the annual total economic cost as the objective function. Given the issues of local convergence and premature convergence encountered during the solution process of the fundamental Grey Wolf optimization algorithm, we employ chaotic mapping technology to address the challenge of unequal initial population distribution. Subsequently, a nonlinear convergence factor is introduced to expedite the convergence rate, enhancing the algorithm’s performance. Lastly, to update the grey wolf’s position, the golden sine operator is used, thereby refining the solution space and enhancing the effectiveness of the optimization process. The simulation outcomes reveal that the enhanced Grey Wolf optimization algorithm notably enhances the precision of the objective function, delivering superior performance. Compared to the Grey Wolf optimization algorithm and Whale optimization algorithm (WOA) [2], the enhanced algorithm demonstrates superiority in terms of reducing economic costs, enhancing the capability for global optimal search, and accelerating the optimization process.
Adaptive control strategy of VSG parameters based on improved fuzzy control
Authors: Xu Xiangyu , Ju Yusheng
Published: September 2024

A virtual synchronous generator (VSG) enables the converter output to have similar external characteristics to the synchronous generator, but its virtual rotary inertia and damping factor need to be flexibly adapted to strengthen the dynamic stability of the system. Given the shortcomings of existing adaptive strategies, this paper presents a VSG parameter adaptive control strategy based on improved fuzzy control. GRO is used to optimize the quantization factor and scale factor of the fuzzy controller, to strengthen the adaptive ability of the fuzzy controller to the rotary inertia and damping factor. Simulink simulation is used to verify the superiority of the control strategy.
Small signal stability analysis of a wind power system integrated with a multi-band supplementary damping controller
Authors: Guo Chaoyu , Li Yanzhe
Published: September 2024

With the integration of wind turbines represented by doubly-fed induction generators (DFIG) into the power system, the inertia level of the system decreases sharply, and small disturbances can easily cause low-frequency oscillation (LFO) in the system. In this paper, we propose a multi-band supplementary damping controller (MBSDC) directly applied to the active power control link of the rotor-side converter in the wind power generation system. We establish a linearized model for DFIG integrated with the power system, calculate eigenvalues, and screen out multiple electromechanical oscillation modes to be suppressed. Based on the calculation results, an MBSDC is designed to suppress LFO, and we propose a parameter-setting algorithm to enhance the suppression effect. Taking the New England 10-generator 39-bus system containing DFIG as an example for simulation verification, the results show that the MBSDC and parameter setting algorithm designed in this paper can effectively suppress LFO.
Research on multi-source separation method of partial discharge based on ABC-JADE
Authors: Wang Jinlong , Zheng Xiang
Published: September 2024

The presence of multiple PD power sources in the switchgear will produce mixed PD signals, which will bring difficulties to the subsequent signal identification work. To solve this problem, this paper uses the exponential signal model to perform hybrid separation and makes ABC (Artificial Bee Colony Algorithm)-JADE (Joint Approximative Diagonalization of Eigen matrices), i.e., the ABC algorithm is a part of the JADE algorithm, and the ABC algorithm introduces the foraging behavior of bees in the search space, which can help the algorithm better explore the solution space. The JADE algorithm is a differential evolution algorithm, which can adjust the algorithm parameters through an adaptive mechanism. In this paper, the similarity coefficient and amplitude relative error index are used to evaluate the signal separation performance, and the experimental results show that the proposed JADE-ABC algorithm can effectively separate mixed signals. The amplitude relative error and phase accuracy of the separated signal and the source signal are within a certain range, and have a certain degree of robustness.
Energy structure optimization of shandong province by 2035 under double carbon goal
Authors: Li Shuyang , Tian Xin , Yuan Zhenhua , Zhang Lina , Xu Weihao , Gao Dan
Published: September 2024

In this paper, based on the existing population size, economic development level, industrial structure, current status of energy production and consumption, and current status of electricity production and consumption in Shandong Province, the LEAP-Shandong model was constructed by using the Long-range Energy Alternatives Planning (LEAP) model as a research tool, which is used to forecast the population size, GDP, energy consumption, and electricity structure of different industries in Shandong Province up to 2035 under three scenarios: policy development scenario, energy efficiency improvement scenario, and enhanced low-carbon scenario. The result shows that the population of Shandong province is expected to peak at 10, 426, 000 by 2033, and then slowly decline; in the enhanced low-carbon scenario, with an appropriate slowdown in economic development, further optimization of industrial structure and enhancement of energy efficiency can effectively reduce the energy consumption of the terminal energy-using sector in Shandong province. Based on the results, the main recommendations for Shandong’s energy development are as follows: to build a low-carbon industrial system in Shandong in light of new development opportunities; to build a new energy development system in light of Shandong’s energy characteristics; and to promote the low-carbon transformation of Shandong’s energy in light of the new model of the energy industry.
Research progress on accounting methods for domestic and international sulfur hexafluoride greenhouse gas emissions reduction
Authors: Zhao Yue , Dong Wangchao , Ma Fengxiang , Zhu Feng , Liu Wei , Song Yumei , Zhu Shan , Chen Han
Published: September 2024

Sulfur hexafluoride (SF6) is a high-quality ultra-high voltage insulating dielectric material with unique insulation and arc-extinguishing properties, and is widely used in power companies. However, sulfur hexafluoride is the strongest known greenhouse gas and is extremely difficult to degrade, so its emissions into the atmosphere need to be strictly limited. In the process of carbon emission reduction, the first step is to conduct carbon accounting, and accounting methods for SF6 emissions at home and abroad are gradually being supplemented and improved. Although major breakthroughs have been made in various aspects of SF6 carbon accounting at home and abroad, there is a lack of comprehensive discussion of the current main progress. This article first summarizes the current process of SF6 carbon accounting under two major categories and four methods at home and abroad. After that, the boundaries of each category, quantification methods, and accounting methods under the four major methods were further compared in detail. Finally, the positive impact that these methods can bring to the company’s operations is analysed from the perspective of inventory reporting, certification application and domestic carbon market transaction profits. This article systematically explains the current research progress from the aspects of method classification, practical operation and final practical application, in order to provide theoretical support for further promoting new accounting methods in the future.
Distributed new energy access grid load voltage deviation adaptive compensation method
Authors: Xiong Xiaocui , Chen Songling , Fang Xiaoming , Zheng Tuo
Published: September 2024

Due to the sensitivity changes of compensation penalty parameters, there is a significant deviation in the load voltage of the distributed new energy access grid. Therefore, it is necessary to consider distributed energy access and design a new adaptive compensation method for grid load voltage deviation. Considering the integration of distributed new energy, an adaptive compensation model for grid load voltage deviation was constructed, and an adaptive compensation inverter for grid load pressure deviation was designed to adaptively compensate for grid load voltage deviation. The experimental results show that after adaptive compensation, the voltage deviation value is lower, which has a good compensation effect, reliability, and certain application values, reducing the operational risk of distributed new energy grids.
Downdraft Gasifier for Oil Palm Empty Bunches with Computational Fluid Dynamics
Authors: Naryanto Rizqi Fitri , Pratama Dafa Oktaditya , Delimayanti Mera Kartika , Karnowo  , Saputro Danang Dwi , Setiyawan Andri , Darsono Febri Budi
Published: September 2024

The demand for palm oil increases every year and this condition proportional to the increase in waste from the manufacture of palm oil. Therefore, this study aims to determine the potential of empty palm fruit bunches to be used as renewable energy. This research simulated Computational Fluid Dynamic (CFD) gasification with empty oil palm fruit bunches using a downdraft gasifier, then simulated with three variations of air flow rates. This is done because the air flow rate is very influential on the temperature and gasification results. The best and uniform variation was obtained at a water flow rate of 25 L/min with a resulting temperature of 28 °C to 957 °C and with an even temperature coverage in the reactor. Then in this study the syngas H2, CO, CO2 and CH4 were obtained which were not evenly distributed in the reactor at all variations of air flow rate, and for the acquisition of syngas H2, CO, CO2 and CH4 the most were obtained at variations of air flow rate of 25 L/min.
Theoretical background and results of a study on changes in oil alkalinity of diesel engines
Authors: Musurmanov Ravshan , Utaev Sobir , Turaev Abdugani
Published: September 2024

Alkalinity is a primary indicator for neutralizing insoluble impurities in oil. Alkaline additives decrease as oils interact with fuel combustion products containing significant amounts of sulfur and nitrogen. Literature data suggests that adding 2-3% of an effective ashless dispersant of a specified type can be equivalent to increasing the alkaline number of the oil by approximately 10 mg KOH/g through the addition of a metal-alkalinity additive to the oil. Based on operational study results, it can be concluded that after the first 100 hours of operation, the alkalinity value ranges from 6-4.3 mg KOH/g, and after 300 hours of operation, the alkalinity value reaches its maximum value of 2 mg KOH/g. Oils with an alkalinity of less than 2 mg KOH/g already indicate an unsatisfactory condition of the oil when lubricating the engine. To maintain the alkalinity value at a given level, it is recommended to continuously introduce tribomechanical stabilizers into the engine lubrication system.
Use of wide-width tractor units in cotton growing
Authors: Tukhtabayev M , Soliev H , Isokova Z
Published: September 2024

The article provides information on recommended traction and power balances of a cotton tractor used in sowing and cultivating 8 rows in growing of cotton seeded at 60 cm row spacing. The purpose of the research is to solve problem of aggregation of sowing and cotton cultivators with four-wheeled tractors and increase their operational-technological and technical-economic performance. According to it, conditions for aggregation of processing units with a tractor are given. The results of scientific and practical research and testing to determine and evaluate performance of machine-tractor units consisting of inter row spacing sowing and cultivators with four-wheel tractors were obtained and analyzed. The dynamics of a tractor in which all bridges are leading and moving forward at a constant speed along a sloping plane are studied. The result is traction balance equation that represents the total traction force of tractor. In particular, the issue of selection and rational aggregation of a tractor model that can be rationally aggregated with a Case-1200 pneumatic seeder has been resolved. It is determined the range of changes the traction resistance and power required to overcome it, the operating weight of tractor, mass and effective power of the Case-1200 seeder.
Some solutions to improve the efficiency and environmental safety of reservoir use
Authors: Khojiyev Aliakbar , Yuldasheva Ozodakhon , Akhmedov Ikromali , Mirkhasilova Zulfiya
Published: September 2024

Flood and landslide control and unhindered management is a global problem worldwide. In high-water years, it is advisable to control the volume of water in reservoirs, taking into account such factors as increased loads on them, due to siltation and sedimentation of soils. In particular, in years with hydrological security of more than 75%, it is necessary to direct the main part of floods and mudflows into the lower stream, for this it is recommended to keep the water level as close as possible to the level of useless volume in high water, and water pumps should operate at full capacity during the passage of floods and downpours. In years when the water consumption of the water source is above 75%, the months of April and May are considered sufficient to create water reserves in high streams. Also, in years when the water consumption of the water source is less than 50%, it is necessary to collect mudflows and floodwaters to create the necessary water supply. In such conditions, it is recommended to carry out the dynamics of stopping water discharge at high temperature as follows. It is advisable to distribute the useless volume of water between the precipitation zones of dense flow and the normal water level in the upper boeuf. Based on this, it is necessary to install “Hydraulic posts” on the upper reaches of reservoirs, with the help of which it is possible to control the transformation of water flows.
Choice justification of the fruit and berry raw materials to produce pasta of the functional purpose
Authors: Krotova I , Doyko I , Leontjev V , Reutov A , Fakhrutdinova Y
Published: September 2024

The article presents the results of the chemical composition study of the whortleberry berries (Vaccinium vitis-idaea L.) and common sea buckthorn (Hippophae rhamnoides L), naturally growing in the forest-steppe zone of the Krasnoyarsk territory. It is shown that the studied biomass contains a rich mineral-vitamin complex, represented by vitamins A, C, group B and P-active substances, as well as magnesium, iron, phosphorus. This circumstance makes it possible to recommend the indicated vegetable raw materials in the production of functional food products. Based on the use of dry powders of the meal of the berries of these plants, a recipe for functional pasta has been developed. It has been established that the introduction of 5 to 10 wt.% of dry powders of the whortleberry berries and sea buckthorn into the classic pasta dough recipe makes the organoleptic properties and nutritional value of the finished product optimal. Consumption of 100 g of the product provides the body with, mg: ascorbic acid - 10.5-21.0; P-active substances - 1.5-6.4; magnesium - 18-30; phosphorus - 9-18; iron - 0.4-1.4. The expert evaluation of organoleptic indicators revealed compliance with regulatory requirements, while the experts noted a pleasant, harmonious taste of the product.
Heat balance and efficiency calculation of a flat-plate solar collector for environmentally friendly food drying
Authors: Safarov J E , Sultanova Sh A , Mambetsheripova A A , Azimov A T
Published: September 2024

This paper deals with one of the main features of solar food drying processes. The thermal properties of the insulator, which is an important element of this process, are studied. It is found that the efficiency of this element is very sensitive to changes in climatic parameters, consistent with sunlight, slightly varying ambient temperature, comfortable humidity and any wind speed. A significant discrepancy is obtained between theoretical and experimental data on the energy of production of mathematical models that allow describing the different interactions and between the different elements of the flat plate collector and the external environment, as well as the exchange of energy and heat. Experiments describing the energy and thermal behaviour of a solar collector are carried out and examples of theoretical modelling are given. The parameters affecting the performance of a rectangular flat-plate solar collector are determined.
Wheat as a test object for determining the degree of soil contamination with petroleum products
Authors: Asfandiyarova L R , Khakimova G V , Ovsyannikova I V
Published: September 2024

Currently, the oil and gas industry remains the leader in meeting the global need for energy resources. The high intensity of hydrocarbon production naturally leads to an increase in the volume of petrochemical waste that ends up in the natural environment. In this regard, the implementation of toxicological assessment of oil-containing soils and water bodies is one of the most important environmental tasks. Biotesting allows for a quick integral assessment of the properties of a contaminated environment. This method of toxicity analysis is economical and does not require the use of special chemical reagents and equipment. The seeds of higher vegetation are the most accessible, easy to use and universal test objects. However, it is necessary to use only species that are highly sensitive to pollutants. This article is based on the results of a study of the phytotoxicity of gray forest soil contaminated with petroleum products using wheat. Experiments have shown that soil contaminated with oil waste has a strong inhibitory effect on wheat seedlings. It was found that small doses of petroleum products (0.31% oil) have a stimulating effect on seed germination in the analyzed soil.