bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of doping on the photogalvanic effect in monolayer MoSSe nanoribbons
Authors: Ji Xiao Kun , Liu Jia
Published: August 2024

Using a first-principles theoretical approach based on the non-equilibrium Green’s function formalism of density functional theory, we have investigated the linear photogalvanic effect and circular photogalvanic effect in monolayer MoSSe nanoribbons under different doping cases: pure MoSSe, Se-vacancy (VSe), S-vacancy (VSe), SSe-transposed (TSSe), Se-substituted S (SeS), and S-substituted Se (SSe). Our results demonstrate that doping reduces the spatial inversion symmetry of monolayer MoSSe, resulting in a significant increase in the photocurrent of the doped system and higher polarization sensitivity. Furthermore, we observed that the armchair direction exhibits a significantly stronger response to linearly polarized light than the zigzag direction, which is more sensitive to circularly polarized light. These findings indicate the wide range of promising applications of 2D MoSSe monolayers, such as in photodetection.
A novel vibrational sensor for high precision viscometry of liquids in wide ranges of temperature and pressure
Authors: Junker Clemens , Laesecke Arno , Meier Karsten
Published: August 2024

This report describes how the insights from the two previous studies led to a newly designed viscosity sensor that centers around a torsionally vibrating piezoelectric quartz cylinder. The main features of the sensor are line conductor electrodes for improved piezoelectric excitation of the torsional vibration of the quartz cylinder and a novel suspension of the cylinder with significantly reduced vibrational losses. The quartz cylinder itself was machined with higher accuracy and much reduced surface roughness than before. The resulting sensor is more compact, easier to assemble, and offers greater access to the liquid whose viscosity is to be determined. The sensor was incorporated and calibrated in an experimental manifold for automated measurements in a wide temperature range from 200 to 420 K with pressures up to 100 MPa. The performance of the sensor is assessed by a detailed uncertainty analysis and validated by measurements of the aromatic hydrocarbon toluene, whose viscosity is considered to be known at standard reference quality. Representative measurement results for most of the experimental temperature range are presented at standard atmospheric pressure, while results for the entire pressure range are reported at two temperatures, 303.15 and 393.15 K, at which comparisons with literature data are possible. They confirm that with an achieved 0.2% the uncertainty development goal of the sensor of less than 1% has been exceeded and is approximately by an order of magnitude improved over previous such sensors, while the repeatability of the new sensor is 0.02%.
Versatile stochastic model for predictive KMC simulation of fcc metal nanostructure evolution with realistic kinetics
Authors: Han Yong , Evans James W.
Published: August 2024

Stochastic lattice-gas models provide the natural framework for analysis of the surface diffusion-mediated evolution of crystalline metal nanostructures on the appropriate time scale (often 101–104 s) and length scale. Model behavior can be precisely assessed by kinetic Monte Carlo simulation, typically incorporating a rejection-free algorithm to efficiently handle the broad range of Arrhenius rates for hopping of surface atoms. The model should realistically prescribe these rates, or the associated barriers, for a diversity of local surface environments. However, commonly used generic choices for barriers fail, even qualitatively, to simultaneously describe diffusion for different low-index facets, for terrace vs step edge diffusion, etc. We introduce an alternative Unconventional Interaction–Conventional Interaction formalism to prescribe these barriers, which, even with few parameters, can realistically capture most aspects of behavior. The model is illustrated for single-component fcc metal systems, mainly for the case of Ag. It is quite versatile and can be applied to describe both the post-deposition evolution of 2D nanostructures in homoepitaxial thin films (e.g., reshaping and coalescence of 2D islands) and the post-synthesis evolution of 3D nanocrystals (e.g., reshaping of nanocrystals synthesized with various faceted non-equilibrium shapes back to 3D equilibrium Wulff shapes).
Effect of active loop extrusion on the two-contact correlations in the interphase chromosome
Authors: Starkov Dmitry , Belan Sergey
Published: August 2024

The population-averaged contact maps generated by the chromosome conformation capture technique provide important information about the average frequency of contact between pairs of chromatin loci as a function of the genetic distance between them. However, these datasets do not tell us anything about the joint statistics of simultaneous contacts between genomic loci in individual cells. This kind of statistical information can be extracted using the single-cell Hi-C method, which is capable of detecting a large fraction of simultaneous contacts within a single cell, as well as through modern methods of fluorescent labeling and super-resolution imaging. Motivated by the prospect of the imminent availability of relevant experimental data, in this work, we theoretically model the joint statistics of pairs of contacts located along a line perpendicular to the main diagonal of the single-cell contact map. The analysis is performed within the framework of an ideal polymer model with quenched disorder of random loops, which, as previous studies have shown, allows us to take into account the influence of the loop extrusion process on the conformational properties of interphase chromatin.
Bubble image segmentation and dynamic feature extraction in gas–liquid two-phase transient flow
Authors: Jiang Dan , Zeng Chen , Chen Wei , Guo Qing , Yan Xin
Published: August 2024

Understanding the dynamics of bubble growth and collapse during gas–liquid two-phase transient flow is crucial for minimizing pipeline wear and maintaining the normal operation of the pipeline system. This paper focuses on obtaining the bubble trajectory, movement velocity, and volume change of gas bubbles. The bubble images during the transient flow are first denoised and enhanced, then the moving target detection algorithm and watershed segmentation algorithm are used to segment the bubbles, and the contour reconstruction of the bubbles is performed using fitting to extract the relevant parameters. The movement trajectories of the bubbles are then traced by analyzing the trajectories and velocities of growth and collapse of the first bubbles during the transient flow, specifically when the flow rate of the hydraulic pipeline is 0.75 m/s. Finally, the changes in gas content during the transient flow in the pipeline under different initial flow rates are compared between the algorithm proposed here and the simulation results.
Stall flutter mitigation of an airfoil by active surface morphing
Authors: Xia Yingjie , Dai Yuting , Huang Guangjing , Yang Chao
Published: August 2024

Stall flutter is a large-amplitude, flow-induced limit cycle oscillation that poses a risk of structural failure of wings. In this paper, a numerical investigation is conducted to explore the mitigation of stall flutter using active surface morphing with a single-mode harmonic motion at a Reynolds number of 1000. The effects of oscillation position and phase on mitigation are evaluated based on the net energy gain of the airfoil over one oscillation cycle. The results show the effectiveness of active surface morphing in mitigating stall flutter, achieving a maximum of 46% reduction in energy obtained by the airfoil from the flow. The control effect is primarily attributed to the decrease in the aerodynamic moment peak during the pitch-up phase and the increase in the aerodynamic moment trough during the pitch-down phase. The former is essentially due to the large-scale clockwise vortex induced by the skin bulging in the pitch-up phase. The latter is fundamentally caused by the weakening of the trailing-edge vortex and the strengthening of the second leading-edge vortex. Finally, maps depicting the energy exchange between the flow and the airfoil system are presented to further demonstrate the control effectiveness of active surface morphing.
Effect of SiC dosage on compressive strength, flexural strength, and bond flexural strength of geopolymer mortar at high temperature
Authors: Huang Weitao , Liu Na , Li Dahai , Zhang Dalin , Yang Guoping
Published: August 2024

This paper investigates the influence of SiC dosage on the high-temperature mechanical properties (compressive strength, flexural strength, and bond flexural strength) of geopolymer mortar. The findings reveal that appropriate amount of SiC was found to improve the high-temperature mechanical properties of geopolymer mortar. Compared to the specimen without SiC, the addition of 3 wt. % SiC to the geopolymer mortar resulted in a noteworthy 14.59% increase in compressive strength at 300 °C, along with respective augmentations of 24.72% and 22.54% in flexural strength and bond flexural strength at 200 °C. Utilizing the experimental data as a foundation, a thermodynamic mathematical model was formulated, linking the strength and temperature parameters of SiC-modified geopolymer mortar. Furthermore, FTIR (Raman and Fourier transform infrared) analysis indicated that the polycondensation reaction of geopolymer mortar treated at 300 °C was promoted, and the products of displacement reaction increased, which provides a plausible explanation for the observed enhancement in compressive strength at 300 °C. Consequently, it is found that the incorporation of SiC can enhance the high-temperature mechanical properties of geopolymer mortar.
Numerical simulations of self-sustained oscillation characteristics in cavity with high-Mach-number flow disturbances
Authors: Jia Mu-Liang , Li Jin-Ping , Chen Shu-Sheng , Zeng Pin-Peng
Published: August 2024

Oscillation characteristics in a cavity are investigated under real experimental conditions through unsteady numerical simulations of the time-evolving oscillatory damping of a high-Mach-number freestream over a two-dimensional forward-facing cavity. The post-disturbance flow field is taken as the initial condition. Temporal variations in the flow field and wall resistance coefficient are obtained. The forward-facing cavity experiences underdamped oscillatory behavior when subjected to disturbances. The convergence of the oscillations is influenced by the cavity volume, with significant reductions in cavity damping observed when stagnation regions develop within the cavity. During the initial phase of disturbance, each oscillation cycle consists of gas injection and jet phases. In the former, external gas stagnates within the cavity, resulting in a gradual increase in internal density and pressure. High-temperature regions extend from the external flow into the cavity, and bow shocks approach the cavity wall, adversely affecting aerodynamic drag reduction and thermal protection for aircrafts. In the jet phase, the flow field structure resembles the opposing jet. As the gas is expelled, the internal cavity pressure decreases, forming a cold jet that envelops the cavity's surface. The temperature within the boundary layer on the surface decreases, and bow shocks are pushed away from the wall, resulting in thermal-protection and drag-reduction effects. Transitions between phases induce instability in the internal flow states within the cavity. During the transition from the gas injection phase to the jet phase, the wall drag coefficient reaches its peak value; the reverse transition results in the lowest wall drag coefficient.
Adaptive evolution of carbapenem-resistant hypervirulent
Klebsiella pneumoniae
in the urinary tract of a single patient
Authors: Song Shikai , Yang Shixin , Zheng Ruicheng , Yin Dandan , Cao Yue , Wang Yao , Qiao Lu , Bai Rina , Wang Shuge , Yin Wenjuan , Dong Yanjun , Bai Li , Yang Hui , Shen Jianzhong , Wu Congming , Hu Fupin , Wang Yang
Published: August 2024

The emergence of carbapenem-resistant hypervirulent
Klebsiella pneumoniae
(CR-hvKp) is a growing concern due to its high mortality and limited treatment options. Although hypermucoviscosity is crucial for CR-hvKp infection, the role of changes in bacterial mucoviscosity in the host colonization and persistence of CR-hvKp is not clearly defined. Herein, we observed a phenotypic switch of CR-hvKp from a hypermucoviscous to a hypomucoviscous state in a patient with scrotal abscess and urinary tract infection (UTI). This switch was attributed to decreased expression of
rmpADC
, the regulator of mucoid phenotype, caused by deletion of the upstream insertion sequence IS
Kpn26
. Postswitching, the hypomucoid variant showed a 9.0-fold decrease in mice sepsis mortality, a >170.0-fold reduction in the ability to evade macrophage phagocytosis in vitro, and an 11.2- to 40.9-fold drop in growth rate in normal mouse serum. Conversely, it exhibited an increased residence time in the mouse urinary tract (21 vs. 6 d), as well as a 216.4-fold boost in adhesion to bladder epithelial cells and a 48.7% enhancement in biofilm production. Notably, the CR-hvKp mucoid switch was reproduced in an antibiotic-free mouse UTI model. The in vivo generation of hypomucoid variants was primarily associated with defective or low expression of
rmpADC
or capsule synthesis gene
wcaJ
, mediated by IS
Kpn26
insertion/deletion or base-pair insertion. The spontaneous hypomucoid variants also outcompeted hypermucoid bacteria in the mouse urinary tract. Collectively, the IS
Kpn26
-associated mucoid switch in CR-hvKp signifies the antibiotic-independent host adaptive evolution, providing insights into the role of mucoid switch in the persistence of CR-hvKp.
Identification of a family of peptidoglycan transpeptidases reveals that
Clostridioides difficile
requires noncanonical cross-links for viability
Authors: Bollinger Kevin W. , Müh Ute , Ocius Karl L. , Apostolos Alexis J. , Pires Marcos M. , Helm Richard F. , Popham David L. , Weiss David S. , Ellermeier Craig D.
Published: August 2024

Most bacteria are surrounded by a cell wall that contains peptidoglycan (PG), a large polymer composed of glycan strands held together by short peptide cross-links. There are two major types of cross-links, termed 4-3 and 3-3 based on the amino acids involved. 4-3 cross-links are created by penicillin-binding proteins, while 3-3 cross-links are created by
L
,
D
-transpeptidases (LDTs). In most bacteria, the predominant mode of cross-linking is 4-3, and these cross-links are essential for viability, while 3-3 cross-links comprise only a minor fraction and are not essential. However, in the opportunistic intestinal pathogen
Clostridioides difficile,
about 70% of the cross-links are 3-3. We show here that 3-3 cross-links and LDTs are essential for viability in
C. difficile
. We also show that
C. difficile
has five LDTs, three with a YkuD catalytic domain as in all previously known LDTs and two with a VanW catalytic domain, whose function was until now unknown. The five LDTs exhibit extensive functional redundancy. VanW domain proteins are found in many gram-positive bacteria but scarce in other lineages. We tested seven non–
C. difficile
VanW domain proteins and confirmed LDT activity in three cases. In summary, our findings uncover a previously unrecognized family of PG cross-linking enzymes, assign a catalytic function to VanW domains, and demonstrate that 3-3 cross-linking is essential for viability in
C. difficile
, the first time this has been shown in any bacterial species. The essentiality of LDTs in
C. difficile
makes them potential targets for antibiotics that kill
C. difficile
selectively.
Nuclear poly-glutamine aggregates rupture the nuclear envelope and hinder its repair
Authors: Korsten Giel , Osinga Miriam , Pelle Robin A. , Serweta Albert K. , Hoogenberg Baukje , Kampinga Harm H. , Kapitein Lukas C.
Published: August 2024

Huntington’s disease (HD) is caused by a polyglutamine expansion of the huntingtin protein, resulting in the formation of polyglutamine aggregates. The mechanisms of toxicity that result in the complex HD pathology remain only partially understood. Here, we show that nuclear polyglutamine aggregates induce nuclear envelope (NE) blebbing and ruptures that are often repaired incompletely. These ruptures coincide with disruptions of the nuclear lamina and lead to lamina scar formation. Expansion microscopy enabled resolving the ultrastructure of nuclear aggregates and revealed polyglutamine fibrils sticking into the cytosol at rupture sites, suggesting a mechanism for incomplete repair. Furthermore, we found that NE repair factors often accumulated near nuclear aggregates, consistent with stalled repair. These findings implicate nuclear polyQ aggregate-induced loss of NE integrity as a potential contributing factor to Huntington’s disease and other polyglutamine diseases.
Integrated stress response activator halofuginone protects mice from diabetes-like phenotypes
Authors: Rai Shashank , Szaruga Maria , Pitera Aleksandra P. , Bertolotti Anne
Published: August 2024

The integrated stress response (ISR) is a vital signaling pathway initiated by four kinases, PERK, GCN2, HRI and PKR, that ensure cellular resilience and protect cells from challenges. Here, we investigated whether increasing ISR signaling could rescue diabetes-like phenotypes in a mouse model of diet-induced obesity (DIO). We show that the orally available and clinically approved GCN2 activator halofuginone (HF) can activate the ISR in mouse tissues. We found that daily oral administration of HF increases glucose tolerance whilst reducing weight gain, insulin resistance, and serum insulin in DIO mice. Conversely, the ISR inhibitor GSK2656157, used at low doses to optimize its selectivity, aggravates glucose intolerance in DIO mice. Whilst loss of function mutations in mice and humans have revealed that PERK is the essential ISR kinase that protects from diabetes, our work demonstrates the therapeutic value of increasing ISR signaling by activating the related kinase GCN2 to reduce diabetes phenotypes in a DIO mouse model.
Finite Temperature Magnetism in the Triangular Lattice Antiferromagnet KErTe2
Authors: Liu 刘 Weiwei 维维 , Zhang 张 Zheng 政 , Yan 闫 Dayu 大禹 , Li 李 Jianshu 建树 , Zhang 张 Zhitao 志涛 , Ji 籍 Jianting 建葶 , Jin 金 Feng 峰 , Shi 石 Youguo 友国 , Zhang 张 Qingming 清明
Published: August 2024

After the discovery of the ARECh2 (A = alkali or monovalent ions, RE = rare-earth, Ch = chalcogen) triangular lattice quantum spin liquid (QSL) family, a series of its oxide, sulfide, and selenide counterparts has been consistently reported and extensively investigated. While KErTe2 represents the initial synthesized telluride member, preserving its triangular spin lattice, it was anticipated that the substantial tellurium ions could impart more pronounced magnetic attributes and electronic structures to this material class. This study delves into the magnetism of KErTe2 at finite temperatures through magnetization and electron spin resonance (ESR) measurements. Based on the angular momentum

J
^

after spin-orbit coupling (SOC) and symmetry analysis, we obtain the magnetic effective Hamiltonian to describe the magnetism of Er3+ in

R

3
¯

m

space group. Applying the mean-field approximation to the Hamiltonian, we can simulate the magnetization and magnetic heat capacity of KErTe2 in paramagnetic state and determine the crystalline electric field (CEF) parameters and partial exchange interactions. The relatively narrow energy gaps between the CEF ground state and excited states exert a significant influence on the magnetism. For example, small CEF excitations can result in a significant broadening of the ESR linewidth at 2 K. For the fitted exchange interactions, although the values are small, given a large angular momentum J = 15/2 after SOC, they still have a noticeable effect at finite temperatures. Notably, the heat capacity data under different magnetic fields along the c axis direction also roughly match our calculated results, further validating the reliability of our analytical approach. These derived parameters serve as crucial tools for future investigations into the ground state magnetism of KErTe2. The findings presented herein lay a foundation for exploration of the intricate magnetism within the triangular-lattice delafossite family.
Demonstration of machine learning-assisted low-latency noise regression in gravitational wave detectors
Authors: Saleem Muhammed , Gunny Alec , Chou Chia-Jui , Yang Li-Cheng , Yeh Shu-Wei , Chen Andy H Y , Magee Ryan , Benoit William , Nguyen Tri , Fan Pinchen , Chatterjee Deep , Marx Ethan , Moreno Eric , Omer Rafia , Raikman Ryan , Rankin Dylan , Sharma Ritwik , Coughlin Michael , Harris Philip , Katsavounidis Erik
Published: August 2024

Low-latency noise regression algorithms are crucial for maximizing the science outcomes of the LIGO, Virgo, and KAGRA gravitational-wave detectors. This includes improvements in the detectability, source localization and pre-merger detectability of signals thereby enabling rapid multi-messenger follow-up. In this paper, we demonstrate the effectiveness of DeepClean, a convolutional neural network architecture that uses witness sensors to estimate and subtract non-linear and non-stationary noise from gravitational-wave strain data. Our study uses LIGO data from the third observing run with injected compact binary signals. As a demonstration, we use DeepClean to subtract the noise at 60 Hz due to the power mains and their sidebands arising from non-linear coupling with other instrumental noise sources. Our parameter estimation study on the injected signals shows that DeepClean does not do any harm to the underlying astrophysical signals in the data while it can enhance the signal-to-noise ratio of potential signals. We show that DeepClean can be used for low-latency noise regression to produce cleaned output data at latencies ~1–2 s. We also discuss various considerations that may be made while training DeepClean for low latency applications.
Inverse source problem for discrete Helmholtz equation
Authors: Novikov Roman , Lal Sharma Basant
Published: August 2024

We consider multi-frequency inverse source problem for the discrete Helmholtz operator on the square lattice

Z

d

,

d
⩾
1

. We consider this problem for the cases with and without phase information. We prove uniqueness results and present examples of non-uniqueness for this problem for the case of compactly supported source function, and a Lipshitz stability estimate for the phased case is established. Relations with inverse scattering problem for the discrete Schrödinger operators in the Born approximation are also provided.
Quantum annealer accelerates the variational quantum eigensolver in a triple-hybrid algorithm
Authors: Jattana Manpreet Singh
Published: August 2024

Hybrid algorithms that combine quantum and classical resources have become commonplace in quantum computing. The variational quantum eigensolver (VQE) is routinely used to solve prototype problems. Currently, hybrid algorithms use no more than one kind of quantum computer connected to a classical computer. In this work, a novel triple-hybrid algorithm combines the effective use of a classical computer, a gate-based quantum computer, and a quantum annealer. The solution of a graph coloring problem found using a quantum annealer reduces the resources needed from a gate-based quantum computer to accelerate VQE by allowing simultaneous measurements within commuting groups of Pauli operators. We experimentally validate our algorithm by evaluating the ground state energy of H2 using different IBM Q devices and the DWave Advantage system requiring only half the resources of standard VQE. Other larger problems we consider exhibit even more significant VQE acceleration. Several examples of algorithms are provided to further motivate a new field of multi-hybrid algorithms that leverage different kinds of quantum computers to gain performance improvements.
Numerical investigation of non-uniform arrays of directive antennas for radiation pattern analysis using spatial modulation schemes
Authors: Chellali Slimani , Khalida Ghanem , Farid Ghanem , Dhasarathan Vigneswaran , Hamza Zeraoula
Published: August 2024

This research presents a novel Non-Uniform Array (NUA) design for Spatial Modulation (SM) systems, aiming to improve Bit Error Rate (BER) performance. The NUA utilizes directional antennas with low-similarity radiation patterns, enabling the receiver to effectively distinguish between signals transmitted from different antenna elements. This enhanced signal discrimination capability directly contributes to improved system capacity and potential spectral efficiency gains for massive MIMO systems employing SM techniques. The proposed NUA was optimized for operation at 5.2 GHz, achieving a high degree of pattern distinguishability. Measured results confirm the effectiveness of the design, demonstrating good agreement with simulations. Moreover, an analysis based on the similarity of the radiation pattern was conducted
Surface-sensitive electronic structure of kagome superconductor CsV3Sb5
Authors: Zhao 赵 Zhisheng 志生 , Yao 姚 Jianghao 江浩 , Xu 徐 Rui 瑞 , Wang 王 Yuzhe 禹喆 , Liao 廖 Sen 森 , Liu 刘 Zhengtai 正太 , Shen 沈 Dawei 大伟 , Cui 崔 Shengtao 胜涛 , Sun 孙 Zhe 喆 , Wang 王 Yilin 义林 , Feng 封 Donglai 东来 , Jiang 姜 Juan 娟
Published: August 2024

We systematically study the electronic structure of a kagome superconductor CsV3Sb5 at different temperatures covering both its charge density wave state and normal state with angle-resolved photoemission spectroscopy. We observe that the V-shaped band around

Γ
¯

shows three different behaviors, referred to as α/α′, β and γ, mainly at different temperatures. Detailed investigations confirm that these bands are all from the same bulk Sb-p
z
origin, but they are quite sensitive to the sample surface conditions mainly modulated by temperature. Thus, the intriguing temperature dependent electronic behavior of the band near

Γ
¯

is affected by the sample surface condition, rather than intrinsic electronic behavior originating from the phase transition. Our result systematically reveals the confusing electronic structure behavior of the energy bands around

Γ
¯

, facilitating further exploration of the novel properties in this material.
W boson mass in NP models with an extra U(1) gauge group*
Authors: Yang 杨 Jin-Lei 金磊 , Ge 葛 Zhao-Feng 兆丰 , Yang 杨 Xiu-Yi 秀一 , Cui 崔 Sheng-Kai 生恺 , Feng 冯 Tai-Fu 太傅
Published: August 2024

The precise measurement of the W boson mass is closely related to the contributions of new physics (NP), which can significantly constrain the parameter space of NP models, particularly those with an additional

local gauge group. The inclusion of a new Z' gauge boson and gauge couplings in these models can contribute to the oblique parameters S, T, and U and the W boson mass at tree level. Considering the effects of kinetic mixing, in this study, we calculate and analyze the oblique parameters S, T, and U and the W boson mass in such NP models. We find that the kinetic mixing effects can make significant contributions to the W boson mass, and these contributions can be eliminated by redefining the gauge boson fields by removing neutral currents with charged leptons if the leptonic Yukawa couplings are invariant under the extra

local gauge group, even with nonzero kinetic mixing effects.
Stochastic scheduling of distribution power networks counting advanced adiabatic compressed air energy storage
Authors: Zhong Geyu , Jiang Pengyu , Xie Ningning , Liu Hanchen , Chang Yong , Mei Shengwei , Lin Zhihua , Chen Laijun
Published: August 2024

Advanced adiabatic compressed air energy storage (AA-CAES) has the advantages of environmental protection, low cost, and high efficiency, which is the mainstream development trend of compressed air energy storage (CAES). The feasibility and economy of distribution network scheduling strategies are affected by the volatility of new energy output and the different operation modes of AA-CAES. This study employs a stochastic planning method to model the uncertain outputs of new energy sources and incorporates the AA-CAES system into the stochastic scheduling model. The objective is to explore the impact of different operating modes of AA-CAES on the scheduling outcomes. The analysis demonstrates that operating the expansion side of AA-CAES under a fixed-pressure mode enhances the economic efficiency of the distribution network compared to a variable-pressure mode. Additionally, the fixed pressure mode offers superior regulation and output capabilities.
Coordinated control strategy for frequency support of wind farm augmented with energy storage system
Authors: Zhu Shaojie , Tao Yibin , Li Guanjun , Xu Zheng , Zhang Jianzhong
Published: August 2024

Owing to the uncontrollable and intermittent nature of wind resources, the frequency support capability of wind turbine generators has strong uncertainty. Employing energy storage systems could improve the frequency support capacity and stability of wind farms. This paper proposes a coordinated control strategy wherein wind power and energy storage collaboratively engage in frequency support operations. At the wind farm and energy storage level, the energy storage gives priority to providing the basic part of the incremental active power, and the wind turbine kinetic energy only takes the deficit. At the wind turbine level, the active power support capacity (APSC) of doubly fed induction generator (DFIG) units is proposed, based on which the coordinated control among wind turbines is designed. Simulation results are presented to validate the effectiveness of the proposed methodology.
The technology of virtual inertia control considering the state of charge of hybrid energy storage
Authors: Zhang Hua , Wang Xin , Wang Wei , Cui Yiqiong
Published: August 2024

There is an increasing amount of new energy power generation being applied in power systems. However, the new energy units have a weak inertia response capability. PV power and large-scale wind energy are linked to the grid, causing the power system’s inertia level to drop noticeably, which has a negative impact on the power system’s frequency stability. Based on this, this paper introduces the Hybrid Energy Storage System (HESS) made up of batteries and supercapacitors, beginning with the concept of power system inertia. The synchronous generator’s rotational kinetic energy is then coupled with the static energy stored in the energy storage device to give it a virtual rotational moment of inertia. Lastly, an analysis is conducted on the HESS’s virtual inertia control technology. Additionally, a sample analysis is performed. The virtual inertia of the HESS is suitably regulated to provide inertia support for the system based on the energy storage device’s state of charge.
Study on the effect of spray flow rate on pumped compressed air energy storage system
Authors: Yang Biao , Li Deyou , Fu Xiaolong , Wang Hongjie , Gong Ruzhi
Published: August 2024

Pumped compressed air energy storage technology can effectively promote the green transformation of energy structure. In this study, the effects of different spray flow rates on operational, energy, and exergy performance were analyzed and compared. It was found that as the spray flow rate increased, the variation of air temperature decreased significantly and the variation of water temperature increased slightly. The larger the spray flow rate is, the stronger the air-water heat transfer performance in the tank will be, and the higher the work consumption of the spraying device will be. When the spray flow rate increases, the air-water heat transfer performance is enhanced, and the power consumption of the spray device is higher. Therefore, when the spray flow rate increases, ηE
first increases and then decreases, and ηx
and ESD continuously increase.
Research on magnetic balance differential protection based on single-core phase-shifting transformer
Authors: Wu Jian , Xue Yushi , Shen You , Chen Lei , Kang Heng , Zheng Tao
Published: August 2024

As an efficient method for managing power flow, phase-shifting transformers have gained widespread applications in the operation of power systems. The protection of phase-shifting transformers is crucial. This paper focuses on the research of a 35kV single-core symmetric phase shifting transformer in a demonstration project. Utilizing the electromagnetic induction law, the operational characteristics of the transformer are analyzed, and the placement of the protection current transformer is determined to design a magnetic balance differential protection scheme. This scheme effectively covers interphase faults, winding lead faults, and interturn faults in the single-core phase-shifting transformer. Furthermore, a model of the single-core phase-shifting transformer is developed using the MATLAB/Simulink platform to verify the effectiveness of the proposed differential protection configuration scheme by simulating typical faults.
Design of a quick connection device for transformer respirator
Authors: Feng Shuo , Wang Yifei , Zhang Zhen , Zhang Yan
Published: August 2024

This article proposes a quick connection device for transformer respirators. The schemes are studied from four aspects: device structure, fastening method, material, and shock-absorbing spring. Through experimental comparison, suitable schemes for respirators are selected and physical objects are made. Finally, the effectiveness of the quick connect device is checked to verify its practicality and effectiveness.
Digital twins design for water cold plate using reduced order model
Authors: Degao Hou , Jiyu Qian , Tao Wei
Published: August 2024

Water cold plates are widely used for heat dissipation in electronic devices. The design of water cold plats includes fluid characterization, heat transfer analysis, and fluid-solid coupling analysis, which are mostly carried out by fluid or thermal design software simulation, resulting in low simulation efficiency. This paper proposes a water cold plate simulation method based on digital twins, which realizes the downgrading of the traditional 3D CFD simulation model to a 1D mathematical model (ROM) and greatly shortens the thermal simulation calculation time. Meanwhile, real-time mapping is established between the physical form of the cold plate and the digital twin model to visualize the traditional invisible and unmeasurable parameters. In addition, based on the external real-time measurement data, the digital twin ROM model is driven to perform calculations and output the results, thus realizing the thermal performance evaluation of the cold plate under various working conditions, which greatly improves the efficiency of thermal design and thermal simulation of electronic devices.
Improvement of the ZJ-17 machine’s separation device based on computational fluid dynamics
Authors: Yang Guanglu , Ding Meizhou , Li Chunguang , Lu Xiaoping , Zhang Jin , Li Yuliang , Zhang Dehai
Published: August 2024

The primary air stem wire separation device employed in the ZJ-17 machine features a single gas inlet, resulting in airflow instability upon entry into the cavity, leading to vortex formation and backflow. This instability adversely affects the separation efficiency of the primary air stem wire, causing significant weight discrepancies in individual cigarette production. By analyzing the stem separation device using Computational Fluid Dynamics (CFD) and conducting test verifications, the design of the primary air separator cavity is optimized, with the double arc guide rectifier identified as the final design solution. The results demonstrate that the optimized double arc-oriented rectifier device boasts a straightforward structure, ensuring stable and dependable operation. It effectively reduces the number of substandard products, enhances the neutrality and stability of cigarette weight, yields substantial economic benefits, and enhances the consistency of cigarette internal flavor absorption.
Geometric error compensation method of five-axis CNC machine tool based on improved genetic algorithm
Authors: Wei Jun , Jiang Lei , Liang Bin
Published: August 2024

A method for compensating geometric errors using an improved genetic algorithm is suggested to mitigate the impact of geometric errors on machining precision in machine tools. The initial step involves a study of the structural and geometric inaccuracies of the five-axis CNC machine tool. Subsequently, theoretical and actual kinematic models of the machine tool are formulated using the method of transformation through homogeneous coordinate matrices, and the overall positional error of the machine tool is determined. Then, the genetic algorithm is improved by narrowing the initial population range and changing the chromosome selection weight in the convergence range, leading to the implementation of error compensation calculations. Ultimately, the effectiveness of this approach is validated by simulating the manufacturing of three-dimensional curved parts in VERICUT.
Research on mechanical properties of lattice structure based on selective laser melting technology
Authors: Wu Ke , Huang Yinqi , Deng Fanghang , Cheng Ying
Published: August 2024

In this research, four lattice frameworks are characterized by different types and relative densities. Quasi-static uniaxial compression tests were performed on lattice structures, resulting in stress-strain curves for these structures while preserving the intended meaning. The findings indicate a reduction in the elastic modulus of the lattice structure from 180 GPa to below 150 MPa when compared to the solid metal structure. The yield strength and elastic modulus of the lattice structure were determined through curve analysis. The successful description of the relationship between the elastic modulus and the relative density of the lattice structure was accomplished through the utilization of the Gibson-Ashby model. The study reveals that its relative density and type primarily influence the strength of the lattice structure.
Controllable preparation of surface nanostructures on boron doped diamond by plasma etching
Authors: Li Xingyu , Ma Guanjie , Long Yuhao , Huang Jiangtao , Zhang Zongyan , Liu Fucheng , Han Peigang , He Bin
Published: August 2024

Due to the high hardness and chemical inertness of diamond, it is difficult to fabricate diamond nanostructures, especially with a high aspect ratio. Plasma etching is an attractive technology for processing diamonds due to its high anisotropic nature and fine controllability, which is of great significance to diamond machining and diamond device fabrication. In this paper, we fabricated large area and high aspect ratio diamond nanoneedle arrays on boron-doped diamond (BDD) by using a maskless inductively coupled plasma (ICP) etching process. The ICP etching was performed in hydrogen (H) and hydrogen/argon (H/Ar) plasma. Then, the influences of duration and pressure on the morphology of diamond nanostructures were studied, and the mechanism of formation of nanoneedle arrays was discussed. The research results show that ICP etching is a simple and efficient method for fabricating diamond nanostructures, which provides a promising way for the industrial fabrication of large-scale BDD nanostructures.
Study on the applicability of gasification coarse slag as admixture for cement-based materials
Authors: Li Haichao
Published: August 2024

To reduce the environmental risks caused by the accumulation of coarse slag and enhance its comprehensive utilization efficiency, this paper takes gasification coarse slag and cement as the main research objects and explores the optimal mix ratio of coarse slag in subgrade materials. By analyzing the fundamental physical and chemical properties of coarse slag and characterizing the hydration products and microstructure of the solidified slurry, the impact of coarse slag content on the strength characteristics of coarse slag-cement-based standard test blocks was investigated. The results showed that the main chemical components of the coarse slag were SiO2, Al2O3, and CaO, and the loss on ignition was 16.18%, which met the suitability requirements of the cement roadbed material. As the mixing ratio of coarse slag continues to increase, the water-cement ratio with fluidity ≥180 mm gradually increases, which would hinder the hydration process of the standard specimen, reduce the generation of hydration products such as C-S-H, destroy the dense structure of the aggregate, and reduce the material strength. When the content of gasified slag was about 15% to 20%, the structure became dense, and the strength of the coarse slag-cement-based material was higher after 28 days of hydration, which was more suitable for engineering applications.
Development of high-level applications for High Energy Photon Source booster
Authors: Peng Yuemei , Ji Daheng , Ji Hongfei , Li Nan , Lu Xiaohan , Tian Saike , Wei Yuanyuan , Xu Haisheng , Zhao Yaliang , Jiao Yi , Li Jingyi
Published: August 2024

The High Energy Photon Source (HEPS), is the first
fourth-generation storage ring light source being built in the
suburb of Beijing, China. The storage ring was designed with the
emittance lower than 60 pm.rad with a circumference of 1.36 km and
beam energy of 6 GeV. Its injector contains a 500 MeV S-band
Linac and a 454 m booster which was designed as an accumulator at
the extraction energy. In the energy ramping control design of HEPS
booster, the ramping process was programed to be able to stop and
stay at any energy between the injection energy and the extraction
energy. This feature enables us to conduct energy-dependent machine
studies and ramping curve optimization. The beam commissioning of
HEPS Linac finished in June, 2023. And the beam commissioning of
booster started in the end of July, 2023. In November 17, main
target values proposed in the preliminary design report has been
reached. The high-level applications (HLAs) are essential tools for
beam commissioning. The development of HLAs, which are based on the
framework named Python accelerator physics application set
(Pyapas), started in the end of 2021. The HEPS physics team
spent more than one year to develop and test the HLAs to meet the
requirements of beam commissioning of the booster. Thanks to the
modular design, the principle based on physical quantities, and the
ability of running simulation models online from the Pyapas,
the development efficiency and reliability of the HLAs have been
greatly improved. In particular, the principle based on physical
quantities allows us to control the beam more intuitively.
Dynamic remodeling model based on chemotaxis of slime molds
Authors: Uza Megumi , Kunita Itsuki
Published: August 2024

Social infrastructure networks, essential for daily life and economic activities, encompass utilities such as water, electricity, roads, and telecommunications. Dynamic remodeling of these systems is crucial for responding to continuous changes, unexpected events, and increased demand. This study proposes a new dynamic remodeling model inspired by biological mechanisms, focusing on a model based on the chemotaxis of slime molds. Slime molds adapt spontaneously to environmental changes by remodeling through the growth and degeneration of tubes. This capability can be applied to optimizing and dynamic remodeling social infrastructure networks. This study elucidated the chemotactic response characteristics of slime molds using biological experiments. The mold’s response was observed by considering changes in the concentration of chemicals as environmental changes, confirming that slime molds adapt to environmental changes by shortening their periodic cycles. Subsequently, based on this dynamic response, we propose a new dynamic model (oscillated Physarum solver, O-PS) that extends the existing Physarum solver (PS). Numerical simulations demonstrated that the O-PS possesses rapid and efficient path-remodeling capabilities. In particular, within a simplified maze network, the O-PS was confirmed to have the same shortest-path searching ability as the PS, while being capable of faster remodeling. This study offers a new approach for optimizing and dynamically remodeling social infrastructure networks by mimicking biological mechanisms, enabling the rapid identification of solutions considering multiple objectives under complex constraints. Furthermore, the variation in convergence speed with oscillation frequency in the O-PS suggests flexibility in responding to environmental changes. Further research is required to develop more effective remodeling strategies.
Healthy eating in globalized food environments: market access and consumer behavior in the Galápagos Islands of Ecuador
Authors: Nicholas Khristopher M , Bentley Margaret E , Terán Enrique , Thompson Amanda L
Published: August 2024

Food environments are the interface between food systems and consumers. Although market access contributes to diet intake, consumer behavior determines food acquisition practices yet is often neglected in food environment research. Implementing sustainable food system transformations in climate-vulnerable, trade-dependent settings requires effective integration of both geographic and experienced-based measures of access. This study in the Galápagos Islands (i) develops measures for geographic and experience-based food environments (EFEs) and (ii) links diet outcomes to these food environment measures independently and when interacted. Cross-sectional household data including diet recalls come from 388 participants in the Healthy Family Study from San Cristóbal Island, Galápagos in 2018. Geocoded market inventory and price data were obtained in 2018 using the Nutritional Environment Measurement Survey for Stores (n = 60). Geographic food environments were created from market scores and distribution. EFEs were based on factor analyzed consumer behavior strategies. Diet quality was defined using the global dietary recommendations score. Adjusted linear regressions tested the relationships between diet and food environment measures and included sociodemographic covariates. Interactions between geographic and EFEs were tested. This study showed that higher prioritization of convenience when food shopping was associated with lower healthy food intake. However, the relationship between food environment measures and diet is strongly modified by consumer behavior. For convenience-prioritizing households, the nearest market proved most associated with healthy diet outcomes. For households with a food-driven purchasing strategy, the preferred market was most associated with healthy diet outcomes. These findings show that market inventory can be healthful or deleterious to diets, depending on how individuals navigate their food environments. Empirical measures of food access that neglect to consider consumer behavior may fail to capture realistic representations of food environment and diet relationships. These findings underscore the importance of tailoring food system changes to incorporate context-specific consumer behavior.