bluuebunny/crossref_metadata_2025 huggingface dataset:
Deep Neck Contouring through the Ages
Authors: Su-Genyk Peiyi , Quatela Vito
Published: March 2024

Deep neck contouring can achieve dramatic results in young and old patients. Both genetic predisposition and aging contribute to the malposition of deep neck structures and a poorly contoured neckline. Depending on the patient's anatomy, deep neck contouring should involve a combination of submental liposuction, platysmaplasty, subplatysmal fat lipectomy, resection of the anterior belly of the digastric muscle, and either cautery or resection of the submandibular glands. Resorption of the facial bony skeleton that occurs with aging affects the ultimate postoperative mandibular contour, and postoperative results thus differ in the young versus old patient. In patients in which there is concern for excess skin laxity, a concurrent facelift is necessary to excise excess neck skin. This article includes a discussion on how a combination of aging and genetics influence a patient's neck anatomy, critical preoperative considerations prior to performing deep neck contouring, intraoperative technique, and adjunct procedures that can further improve a patient's neckline.
Targeted Neonatal Echocardiography: Basics of Knobology 101
Authors: Surak Aimann , Altit Gabriel , Singh Yogen
Published: March 2024

Targeted neonatal echocardiography (TNE) is essential when approaching hemodynamic instability in neonates. Competency in this field requires standardized training, including robust hands-on experience. Proficiency in understanding the key elements of ultrasound knobology is indispensable for optimal acquisition of imaging. This is a narrative review summarizing the key elements of knobology in TNE. Literature review was mainly done through PubMed. There was no funding allocated for the production of this manuscript.

Key Points
The associative ionization of N(2P) + O(3P)
Authors: Shuman Nicholas S. , Miller Thomas M. , Ard Shaun G. , Viggiano Albert A.
Published: March 2024

The rate constant of the associative ionization reaction N(2P) + O(3P) → NO+ + e− was measured using a flow tube apparatus. A flowing afterglow source was used to produce an ion/electron plasma containing a mixture of ions, including N2+, N3+, and N4+. Dissociative recombination of these species produced a population of nitrogen atoms, including N(2P). Charged species were rejected from the flow tube using an electrostatic grid, subsequent to which oxygen atoms were introduced, produced either using a discharge of helium and oxygen or via the titration of nitrogen atoms with NO. Only the title reaction can produce the NO+ observed after the introduction of O atoms. The resulting rate constant (8 ± 5 ×10−11 cm3 s−1) is larger than previously reported N(2P) + O disappearance rate constants (∼2 × 10−11 cm3 s−1). The possible errors in this or previous experiments are discussed. It is concluded that the N(2P) + O(3P) reaction proceeds almost entirely by associative ionization, with quenching to the 2D or 4S states as only minor processes.
Nonlinear beat wave decay of Kelvin/diocotron waves on a two-dimensional vortex
Authors: Dubin Daniel H. E. , Kabantsev A. A. , Driscoll C. F.
Published: March 2024

We describe theory and experiments investigating nonlinear beat wave decay of diocotron modes on a nonneutral plasma column (or Kelvin waves on a vortex). Specifically, a Kelvin/diocotron pump wave varying as Ap exp [i(lpθ−ωpt)] decays into two waves: a Kelvin/diocotron daughter wave with exponentially growing amplitude Ad(t), mode number ld<lp, and frequency ωd; and an exponentially growing “beat wave” with mode number lb and frequency ωb. Nonlinear wave–wave coupling requires lb=lp−ld and ωb=ωp−ωd. The new theory simplifies and extends a previous weak-turbulence theory for the exponential growth rate of this instability, by instead using an eigenmode expansion to describe the beat wave as a wavepacket of continuum (Case/van Kampen) modes. The new theory predicts the growth rate, the nonlinear frequency shift (both proportional to Ap2), and the functional form of the beat wave, with amplitude proportional to ApAd*(t). Experiments observe beat wave decay on electron plasma columns for a range of mode numbers up to lp=5 and ld = 4, with results in quantitative agreement with the theory, including the ld = 1 case for which measured growth rates are negligible, as expected theoretically.
The influence of an externally applied electric field on residual microparticle charge in a spatio-temporal afterglow plasma
Authors: van Huijstee J. C. A. , Blom P. , Beckers J.
Published: March 2024

The residual charge of dust particles in spatial and temporal afterglow plasmas is relevant in many fundamental research fields and technological applications. It has been shown in both spatial and temporal afterglow plasmas that the presence of an externally applied electric field can greatly influence the residual dust particle charge. However, this has not yet been explored in a combined spatiotemporal afterglow plasma. In this work, the influence of an externally applied electric field on the residual microparticle charge is, therefore, investigated in a spatiotemporal afterglow plasma. It is found that the measured charge is predominantly affected by changes to the spatial component of the spatiotemporal afterglow when an electric field is applied, while the influence on the temporal component seems to be significantly less relevant. Our results contribute to an improved understanding of particle (de-)charging in afterglow plasmas and are highly relevant to the design of applications in which afterglow plasmas are present and where the charge of dust particles needs to be controlled for the sake of (nano)contamination control.
Evaporation of acoustically levitated ouzo droplets
Authors: Fang Zilong , Taslim Mohammad E. , Wan Kai-Tak
Published: March 2024

An ouzo droplet is a multicomponent liquid comprising ethanol, water, and anise oil, each possessing distinct thermophysical properties, volatility, and mutual miscibility. Evaporation leads to the complex physicochemical process of coupled mass and heat transfer, spontaneous emulsification, and liquid–liquid phase separation, known as the ouzo effect. An acoustically levitated ouzo droplet undergoes five characteristic stages of evaporation based on temporal temperature variation. Such levitated droplet shows a significantly longer lifespan upon evaporation because of the thermal isolation in air, as well as a drastic initial cooling. Sessile droplets, on the other hand, have heat transferred from the surroundings via the substrate to replenish latent heat of vaporization. A conductive substrate thus helps the droplet to stay close to the ambience and a shorter lifespan. A rudimentary theoretical model based on dimensional analysis is developed and shows consistency with measurements.
Proton tunneling in the dissociation of H2+ and its asymmetric isotopologues driven by circularly polarized THz laser pulses
Authors: Tian Yidian , Liu Kunlong , Wang Yuchen , Zhou Yueming , Lu Peixiang
Published: March 2024

Light-induced deprotonation of molecules is an important process in photochemical reactions. Here, we theoretically investigate the tunneling deprotonation of H2+ and its asymmetric isotopologues driven by circularly polarized THz laser pulses. The quasi-static picture shows that the field-dressed potential barrier is significantly lowered for the deprotonation channel when the mass asymmetry of the diatomic molecule increases. Our numerical simulations demonstrate that when the mass symmetry breaks, the tunneling deprotonation is significantly enhanced and the proton tunneling becomes the dominant dissociation channel in the THz driving fields. In addition, the simulated nuclear momentum distributions show that the emission of the proton is directed by the effective vector potential for the deprotonation channel and, meanwhile, the angular distribution of the emitting proton is affected by the alignment and rotation of the molecule induced by the rotating field.
Experimental characterization of SiCH+via single-photon ionization of gas-phase SiCH
Authors: Chen N. L. , Gans B. , Boyé-Péronne S. , Hartweg S. , Garcia G. A. , Loison J.-C.
Published: March 2024

SiCH and its cation have consistently emerged as predicted species in models of silicon chemistry within the interstellar medium, although they remain unobserved in space. Hindered by their intrinsic instability, no spectroscopic insights have been gleaned concerning the SiCH+ cation. In this study, we present experimental measurements on the SiCH+ cation through single-photon ionization spectroscopy of the SiCH radical within the 8.0–11.0 eV range. Gas-phase SiCH radicals were generated through chemical reactions involving CHx (x = 0–3) and SiHy (y = 0–3) within a microwave discharge flow-tube reactor. Employing a double imaging photoelectron/photoion coincidence spectrometer on the DESIRS beamline at the SOLEIL synchrotron, we recorded mass-selected ion yield and photoelectron spectra. From the analysis of the photoelectron spectrum supported by ab initio calculations and Franck–Condon simulations, the adiabatic ionization energies for the transitions from the X2Π ground electronic state of SiCH toward the X+3Σ− and A+3Π electronic states of SiCH+ have been derived [8.935(6) and 10.664(6) eV, respectively, without spin–orbit correction]. The contribution from the less stable isomer HSiC has been explored in our analysis and ruled out in our experiments.
Introducing the concept of generalized thermal diffusivity to understand coupled heat–charge transport in ionic solutions
Authors: Cappai Antonio , Dettori Riccardo , Marini Federica , Melis Claudio , Colombo Luciano
Published: March 2024

A theoretical framework addressing the coupled thermal and charge transport phenomena in ionic solutions is here developed. Starting from the microscopic definitions of thermal and charge currents from Onsager formulation of non-equilibrium thermodynamics, a unique, very general and compact form of the governing differential equation for the evolution of a temperature profile is derived. In particular, the concept of generalized thermal diffusivity is introduced to capture the overall effect of the coupling between heat and charge transport in a single phenomenological coefficient as well as to shed light on the non-equivalent situations of concurrent or discordant heat and charge currents. To validate our theoretical framework, an ionic salt solution of NaCl in water is investigated.
Dual topologies of myotomal collagen XV and Tenascin C act in concert to guide and shape developing motor axons
Authors: Nemoz-Billet Laurie , Balland Martial , Gilquin Laurent , Gillet Benjamin , Stévant Isabelle , Guillon Emilie , Hughes Sandrine , Carpentier Gilles , Vaganay Elisabeth , Sohm Frédéric , Misiak Vladimir , Gonzalez-Melo Mary-Julieth , Koch Manuel , Ghavi-Helm Yad , Bretaud Sandrine , Ruggiero Florence
Published: March 2024

During development, motor axons are guided toward muscle target by various extrinsic cues including extracellular matrix (ECM) proteins whose identities and cellular source remain poorly characterized. Here, using single-cell RNAseq of sorted GFP
+
cells from
smyhc1:gfp
-injected zebrafish embryos, we unravel the slow muscle progenitors (SMP) pseudotemporal trajectory at the single-cell level and show that differentiating SMPs are a major source of ECM proteins. The SMP core-matrisome was characterized and computationally predicted to form a basement membrane–like structure tailored for motor axon guidance, including basement membrane–associated ECM proteins, as collagen XV-B, one of the earliest core-matrisome gene transcribed in differentiating SMPs and the glycoprotein Tenascin C. To investigate how contact-mediated guidance cues are organized along the motor path to exert their function in vivo, we used microscopy-based methods to analyze and quantify motor axon navigation in
tnc
and
col15a1b
knock-out fish. We show that motor axon shape and growth rely on the timely expression of the attractive cue Collagen XV-B that locally provides axons with a permissive soft microenvironment and separately organizes the repulsive cue Tenascin C into a unique functional dual topology. Importantly, bioprinted micropatterns that mimic this in vivo ECM topology were sufficient to drive directional motor axon growth. Our study offers evidence that not only the composition of ECM cues but their topology critically influences motor axon navigation in vertebrates with potential applications in regenerative medicine for peripheral nerve injury as regenerating nerves follow their original path.
Steering lithium and potassium storage mechanism in covalent organic frameworks by incorporating transition metal single atoms
Authors: Cao Yingnan , Xu Qing , Sun Yi , Shi Jixin , Xu Yi , Tang Yongfu , Chen Xiudong , Yang Shuai , Jiang Zheng , Um Han-Don , Li Xiaopeng , Wang Yong
Published: March 2024

Organic electrodes mainly consisting of C, O, H, and N are promising candidates for advanced batteries. However, the sluggish ionic and electronic conductivity limit the full play of their high theoretical capacities. Here, we integrate the idea of metal-support interaction in single-atom catalysts with π–d hybridization into the design of organic electrode materials for the applications of lithium (LIBs) and potassium-ion batteries (PIBs). Several types of transition metal single atoms (e.g., Co, Ni, Fe) with π–d hybridization are incorporated into the semiconducting covalent organic framework (COF) composite. Single atoms favorably modify the energy band structure and improve the electronic conductivity of COF. More importantly, the electronic interaction between single atoms and COF adjusts the binding affinity and modifies ion traffic between Li/K ions and the active organic units of COFs as evidenced by extensive in situ and ex situ characterizations and theoretical calculations. The corresponding LIB achieves a high reversible capacity of 1,023.0 mA h g
−1
after 100 cycles at 100 mA g
−1
and 501.1 mA h g
−1
after 500 cycles at 1,000 mA g
−1
. The corresponding PIB delivers a high reversible capacity of 449.0 mA h g
−1
at 100 mA g
−1
after 150 cycles and stably cycled over 500 cycles at 1,000 mA g
−1
. This work provides a promising route to engineering organic electrodes.
The circadian molecular clock in the suprachiasmatic nucleus is necessary but not sufficient for fear entrainment
Authors: Bussi Ivana L. , Ben-Hamo Miriam , Salazar Leon Luis E. , Casiraghi Leandro P. , Zhang Victor Y. , Neitz Alexandra F. , Lee Jeffrey , Takahashi Joseph S. , Kim Jeansok J. , de la Iglesia Horacio O.
Published: March 2024

We show that nocturnal aversive stimuli presented to mice while they are eating and drinking outside of their safe nest can entrain circadian behaviors, leading to a shift toward daytime activity. We also show that the canonical molecular circadian clock is necessary for fear entrainment and that an intact molecular clockwork in the suprachiasmatic nucleus, the site of the central circadian pacemaker, is necessary but not sufficient to sustain fear entrainment of circadian rhythms. Our results demonstrate that entrainment of a circadian clock by cyclic fearful stimuli can lead to severely mistimed circadian behavior that persists even after the aversive stimulus is removed. Together, our findings support the interpretation that circadian and sleep symptoms associated with fear and anxiety disorders are, in part, the output of a fear-entrained clock, and provide a mechanistic insight into this clock.
Phenotypic screen of sixty-eight colorectal cancer cell lines identifies CEACAM6 and CEACAM5 as markers of acid resistance
Authors: Michl Johanna , White Bobby , Monterisi Stefania , Bodmer Walter F. , Swietach Pawel
Published: March 2024

Elevated cancer metabolism releases lactic acid and CO
2
into the under-perfused tumor microenvironment, resulting in extracellular acidosis. The surviving cancer cells must adapt to this selection pressure; thus, targeting tumor acidosis is a rational therapeutic strategy to manage tumor growth. However, none of the major approved treatments are based explicitly on disrupting acid handling, signaling, or adaptations, possibly because the distinction between acid-sensitive and acid-resistant phenotypes is not clear. Here, we report pH-related phenotypes of sixty-eight colorectal cancer (CRC) cell lines by measuring i) extracellular acidification as a readout of acid production by fermentative metabolism and ii) growth of cell biomass over a range of extracellular pH (pHe) levels as a measure of the acid sensitivity of proliferation. Based on these measurements, CRC cell lines were grouped along two dimensions as “acid-sensitive”/“acid-resistant” versus “low metabolic acid production”/“high metabolic acid production.” Strikingly, acid resistance was associated with the expression of
CEACAM6
and
CEACAM5
genes coding for two related cell-adhesion molecules, and among pH-regulating genes, of
CA12
. CEACAM5/6 protein levels were strongly induced by acidity, with a further induction under hypoxia in a subset of CRC lines. Lack of CEACAM6 (but not of CEACAM5) reduced cell growth and their ability to differentiate. Finally, CEACAM6 levels were strongly increased in human colorectal cancers from stage II and III patients, compared to matched samples from adjacent normal tissues. Thus, CEACAM6 is a marker of acid-resistant clones in colorectal cancer and a potential motif for targeting therapies to acidic regions within the tumors.
Characterizations of vacuum solutions of f(R) − gravity in space-times admitting Z tensor of Codazzi type
Authors: Syied Abdallah Abdelhameed , De Uday Chand , Bin Turki Nasser , Vîlcu Gabriel-Eduard
Published: March 2024

In this work, characterizations of vacuum solutions of f(R)-gravity are established in a space-time whose Z tensor is of Codazzi type. We prove that the associated covector of a (PZS)
n
space-time is an eigenvector of the Ricci tensor, with an eigenvalue equals zero. Additionally, it satisfies compatibility conditions with both the Riemann and Weyl tensors. It is proved that a (PZS)
n
space-time satisfying f(R)-gravity vacuum solutions is a generalized Friedmann-Robertson-Walker space-time. If n = 4, it becomes a Friedmann-Robertson-Walker space-time.
Characterization of plastic scintillator samples produced by a university-SME Collaboration
Authors: Akgün Bora , Öztürk Sertaç , Nurdan Kıvanç , Özcan V Erkcan , Ünel N Gökhan , Kolbaşı Asuman , Elibollar Emre , Ünal Arda , Kandemir Mustafa , Şahin Yağızhan , Kara Burak , Akbulut Zeynep , Koyutürk Cengizhan , Kaçar Hazal Candan , Özkan Sungur , Yüksel Efe Mert
Published: March 2024

Scintillator samples are synthesized by a university-SME collaboration and the light yield, light emission and light transmission properties are studied with the aim of determining the fluor content that gives the highest light yield. Three plastic scintillator samples with different fluor additives are produced and their optical properties are found to be comparable with a high-light-yield EJ-204 reference sample. Amongst the three, the sample with 0.75% PPO + 0.75 %PTP and 0.04% POPOP + 0.04% Bis-MSB provides the highest light yield. The authors plan to use the same fluor additive concentration to produce application-specific scintillators that are not commercially available for nuclear reactor monitoring and medical applications.
Boosting asymmetric measurement-device-independent quantum key distribution via numerical-analysis technology
Authors: Li Zijian , Zheng Bingbing , Zhang Heqian , Zhang Zhenrong , Wei Kejin
Published: March 2024

Asymmetric measurement-device-independent quantum key distribution (MDI-QKD) enables building a scalable, high-rate quantum network with an untrusted relay in real-world scenarios. In this study, we improve the performance of asymmetric MDI-QKD using numerical analysis techniques. Simulation results show a twofold increase in tolerance to basis misalignment compared to the previous state-of-the-art method. Specifically, for instances of substantial basis misalignment, the key rate increases by an order of magnitude, and the maximum communication distance extends by 20 km. Our work significantly enhances the robustness and feasibility of asymmetric MDI-QKD, thereby promoting the widespread deployment of MDI-QKD networks.
Magnetic moments of astrophysical neutrinos
Authors: Kopp Joachim , Opferkuch Toby , Wang Edward
Published: March 2024

We study the impact of neutrino magnetic moments on astrophysical neutrinos, in particular
supernova neutrinos and ultra-high energy neutrinos from extragalactic sources. We show that
magnetic moment-induced conversion of Dirac neutrinos from left-handed states into unobservable
right-handed singlet states can substantially change the flux and flavour composition of these
neutrinos at Earth. Notably, neutrinos from a supernova's neutronisation burst, whose flux can be
predicted with 𝒪(10%) accuracy, offer a discovery reach to neutrino magnetic moments
 ∼ few × 10-13
μB
, up to one order of magnitude below current limits. For
high-energy neutrinos from distant sources, for which no robust flux prediction exists, we show
how the flavour composition at Earth can be used as a handle to establish the presence of
non-negligible magnetic moments, potentially down to few× 10-17
μB
if the
measurement can be performed on neutrinos from a single source. In both cases, the sensitivity
strongly depends on the galactic (intergalactic) magnetic field profiles along the line of
sight. Therefore, while a discovery is possible down to very small values of the magnetic moment,
the absence of a discovery does not imply an equally strong limit. We also comment on the
dependence of our results on the right-handed neutrino mass, paying special attention to the
transition from coherent deflection by a classical magnetic field to incoherent scattering on
individual scattering targets. Finally, we show that a measurement of Standard Model Dirac
neutrino magnetic moments, of order 10-19
μB
, could be possible under rather optimistic,
but not completely outrageous, assumptions using flavour ratios of high-energy astrophysical
neutrinos.
Bottle-shaped second harmonic generation with adjustable locations
Authors: Hu Xiaokang , Sheng Yan , Zhao Ruwei , Liu Shan , Xu Tianxiang , Chen Feng
Published: March 2024

Nonlinear photonic crystals (NPCs) have been widely used for studying nonlinear wave behaviors and in many applications requiring generation of light at new frequencies. In particular, the nonlinear photonic structures can be smartly designed to facilitate multiple functions in a single crystal. Here we show how to design a two-dimensional NPC to realize bottle-shaped second harmonic generation from a fundamental Gaussian beam with adjustable converging properties. The influences of structural parameters on the bottle beam generation are also investigated. These results are important for playing full potentials of NPCs and provide a convenient way to generate special beam at new frequencies with controllable properties.
On the existence and stability of traversable wormhole solutions with novel shapefunctions in the framework of
F(R,Lm)
gravity
Authors: Chaudhary Sourav , Kumar Jitendra , Maurya S K , Kiroriwal Sweeti , Aziz Abdul
Published: March 2024

In this work, we have explored wormhole (WH) solutions in

F
(
R
,

L

m

)

gravity by assuming the Morris–Thorne WH metric and

F
(
R
,

L

m

)
=

R

2

+
(
1
+
γ
R
)

L

m

, where γ is the free model parameter. We determined the WH solutions by utilizing two newly developed shape functions (SF) that satisfy all basic conditions for a WH’s physical validity. We also observe that the null energy condition (NEC) behaves negatively. Finally, for both models, we use the volume integral quantifier (

V
I
Q

) and Tolman–Oppenheimer–Volkoff (TOV) equation to determine how much exotic matter is needed near the WH throat and the stability of the WH. The extensive detailed discussions of the matter components have been done via graphical analysis. The obtained WH geometries meet the physically acceptable conditions for a stable wormhole.
Astronomical Test with CMOS on the 60 cm Telescope at the Xinglong Observatory, NAOC
Authors: Mu Hai-Yang , Fan Zhou , Zhu Yi-Nan , Zhang Yu , Wu Hong
Published: March 2024

This work shows details of an evaluation of an observational system comprising a complementary metal-oxide-semiconductor detector, 60 cm telescope and filter complement. The system’s photometric precision and differential photometric precision, and extinction coefficients were assessed through observations of Supersky flat fields, open clusters, standard stars and exoplanets. Photometry was precision achieved at the 0.02 mag level, with differential photometry of 0.004 mag precision. Extinction was found to agree with previous studies conducted at Xinglong Observatory. Ultimately, the results demonstrate this observing system is capable of precision scientific observations with a charge-coupled device across the optical wavelengths.
Pulsed interactions unify reaction–diffusion and spatial nonlocal models for biological pattern formation
Authors: Colombo Eduardo H , Martinez-Garcia Ricardo , Calabrese Justin M , López Cristóbal , Hernández-García Emilio
Published: March 2024

The emergence of a spatially organized population distribution depends on the dynamics of the population and mediators of interaction (activators and inhibitors). Two broad classes of models have been used to investigate when and how self-organization is triggered, namely reaction–diffusion and spatially nonlocal models. Nevertheless, these models implicitly assume smooth propagation scenarios, neglecting that individuals interact many times by exchanging short and abrupt pulses of the mediating substance. A recently proposed framework has made advances in properly accounting for these short-scale fluctuations by applying a coarse-graining procedure on the pulse dynamics. In this paper, we generalize the coarse-graining procedure and apply the extended formalism to new scenarios in which mediators influence individuals’ reproductive success or their motility. We show that, in the slow- and fast-mediator limits, pulsed interactions recover, respectively, the reaction–diffusion and nonlocal models, providing a mechanistic connection between them. Furthermore, at each limit, the spatial stability condition is qualitatively different, leading to a timescale-induced transition where spatial patterns emerge as mediator dynamics becomes sufficiently fast.
Experimental research on the thermal performance of the dry conduction plate for multi-point electronic chips
Authors: Zhou Jie , Zhan Dongdong , Qian Jiyu , Wei Tao
Published: March 2024

This paper designs a dry conductive heat dissipation method using several parallel heat pipes to solve the difficulty of the thermal management problem of multi-point electronic chips. The heat sources are distributed along the heat pipe, whose heat is efficiently conducted from the middle to the cold plate on the two sides. The effect of gravity, flow rate, and heat source distributions on the heat transfer performance is studied. The testing data indicated that gravity has less effect on the conduction performance of heat pipes for the cooling on two sides. As the heat sources concentrate in the centre, the heat pipe temperature difference between the centre and the side increases under the same transmission power. The results demonstrated that the two-side cooling and multi-point distribution heat conduction method is conducive to improving the thermal management capability under different inclination angles.
Research on multi-objective parameter optimization of split flow dual flash thermodynamic cycle
Authors: Huang Zheng , Zhang Yanting , Wang Lin , Xu Jingyu , Zheng Yunlong
Published: March 2024

In addition to considering the intermediate pressure variables, the split flow double flash thermodynamic cycle also needs to consider the operating conditions and split flow coefficient of the cycle. Traditional algorithms require too much computation and have a longer response time. Faced with sudden operating conditions or changes in production conditions, it is difficult to quickly re-optimize the intermediate parameters of the split flow double flash thermal cycle and carry out corresponding system control. This article uses intelligent optimization algorithms instead of global search methods to optimize multi-objective parameters in a split flow double flash thermodynamic cycle. By summarizing and analyzing the characteristics of algorithms such as SIO, EA, and ANN, it is believed that the GWO algorithm in the SIO class is the most suitable for multi-objective parameter optimization of the split flow double flash thermal cycle. It is combined with the SA optimization algorithm to propose the SA-GWO algorithm with faster optimization speed and higher optimization accuracy, taking the initial position of the wolf pack as the optimization objective. Combined with the cycle thermodynamic model, a multi-objective parameter optimization model for the split flow double flash thermal cycle is established.
Research on capacity optimization of new energy hybrid energy storage system of high-speed railway
Authors: Li Guangyao , Yuan Jiaxin , Gan Dongliang
Published: March 2024

With the fast expansion of electrified railways, the need for energy is growing. Thus, improving railway coupling and interconnection, new energy, and energy storage is critical to support low-carbon and green railway development. Therefore, this paper proposes an optimal configuration method for the access capacity of wind power generation system (WPGS), photovoltaic power system (PVPS), and hybrid energy storage system (HESS) in the traction power supply system (TPSS) of high-speed railways. Firstly, the HESS’s mathematical model is developed, then the high-speed railway TPSS’s economic optimization operating model is built, and a HESS energy management approach is presented, taking the energy management strategy parameters and model capacity configuration parameters as the optimization variables. The mixed integer linear programming approach is used to resolve the actual example with the least daily operational cost of the high-speed rail system as the optimization goal, and the optimal capacity of WPGS, PVPS, and HESS is obtained. Finally, through comparison and analysis, it is verified that the economic benefit is the highest when the distributed complementary energy system covering WPGS, PVPS, and HESS is connected to the traction substation, and 10.47% of the daily expenditure is saved.
Evaluation method of distributed photovoltaic maximum access capacity based on ADMM
Authors: Wu Zihao , Fan Yujiao , Li Wei
Published: March 2024

With the increasing penetration rate of distributed photovoltaics in the distribution network, new requirements are put forward for the operation and control of distribution networks. In order to ensure that the distribution network can operate stably within a safe range, it is important to evaluate the maximum capacity of the distribution network that can be connected to distributed photovoltaics. Considering the high cost of centralized computing, high communication requirements, and poor reliability, it is difficult to adapt to the actual needs of the distribution network with large-scale access to distributed photovoltaics. Therefore, this paper proposes an ADMM-based distributed PV maximum access capacity evaluation method. This method takes the distributed photovoltaic access capacity and the active power loss of the distribution network line as the objective function and considers the power flow equation constraints, node voltage constraints, and line current carrying capacity constraints of the distribution network. By simplifying the model, the non-convex optimization problem is transformed into a convex quadratic programming problem, and the ADMM algorithm is used to solve the distributed solution to obtain the access strategy of distributed PV in various regions under different operating conditions. Finally, the IEEE-33 system is used as an example to simulate the calculation, and the experimental results verify the correctness and effectiveness of the method.
Study on overvoltage suppression method of phase modulation of hydroelectric generating units and its cooperative optimization in new energy grid
Authors: Xu Weiguang , Wang Jiakun , Ji Supeng
Published: March 2024

When a significant portion of renewable energy is transmitted to the power grid through high voltage direct current, when the monopolar blocking occurs, as a result of the converter station’s filter and reactive power compensation equipment’s influence, overvoltage will be generated, which will cause harm to the new energy station, and even lead to large-scale new energy grid disconnection. This paper initially examines the mechanism behind overvoltage in a new energy power grid and then puts forward a method to restrain overvoltage by using phase modulation operation of hydroelectric generating units. To improve the phase modulation capability of hydroelectric generating units and optimize the utilization of new energy sources, this paper proposes a particle swarm optimization to determine the optimal phase modulation capacity. Finally, this paper builds an example of the PSASP platform to verify the correctness and effectiveness of collaborative optimization.
Short-term PV power prediction study based on FCM-BiGRU
Authors: Yin Pan , Wang Hui , Xiao Jieping , Zhou Weichao , Shao Bowei , Li Wenliang
Published: March 2024

Addressing the issue of large prediction error in short-term load prediction of existing neural network models, this study proposes a short-term load forecasting approach that combines fuzzy C-mean clustering and a two-way gated recurrent neural network model. Fuzzy C-mean clustering is first applied to cluster the original data into three typical days, and the grouped data are trained using a bidirectional gated recurrent neural network model for load prediction. The conclusive experiment demonstrates that the proposed approach introduced in this study exhibits a high prediction accuracy in the context of short-term photovoltaic output forecasting, and there is also a substantial error reduction compared with the existing neural network methods.
Fault diagnosis of building electrical system based on compressed perception theory
Authors: Xie Sijia
Published: March 2024

Building electrical systems in modern buildings are increasingly playing a pivotal role in bringing people the convenience of life, at the same time, the building electrical system will inevitably fail. And the research of intelligent fault diagnosis algorithms for this field is still in its infancy. At this stage, the accuracy and reliability of fault monitoring and diagnosis of most building electrical systems are yet to be improved. Aiming at the current lack of effective diagnosis of faults in the building electrical system, this paper takes the fault situation of the electrical system in the building as the main object of research, and simulates the common building electrical faults through the comprehensive experimental platform of the building electrical, taking into account the problem of low diagnostic efficiency of the building electrical system. This paper puts forward a fault diagnostic algorithm based on the combination of compressed perception and the K-nearest neighbor algorithm, which is aimed at improving the diagnostic efficiency of building electrical system faults. The results show that the proposed fault diagnosis algorithm can not only improve the accuracy of fault classification but also shorten the time of fault classification, which greatly improves the fault diagnosis efficiency.
A method for identifying the operating state of deteriorated insulators based on partial discharge signal reconstruction algorithm and spatial electric field distribution law
Authors: Li Yong , Wang Siqi , Yang Li , Zeng Chen , Wang Ming , Chen Yao
Published: March 2024

In order to improve the accuracy of identifying the working status of degraded insulators and thereby contribute to preventive maintenance and repair, this proposes a method for identifying the operating status of deteriorated insulators based on a partial discharge signal reconstruction algorithm and spatial electric field distribution law. Firstly, the partial discharge signal of the deteriorated insulator is obtained through capacitive sensor technology and clustering analysis algorithm. Then, the mapping features between the partial discharge signal and the electric field distribution are extracted using the SN-EMD algorithm to determine the spatial electric field distribution on the surface of the insulator. Finally, a state recognition model is established based on the hidden Markov model to identify the operating status of deteriorated insulators. The experimental results show that the method designed in this paper has superior performance in terms of accuracy.
Short-term prediction of photovoltaic power generation based on ICEEMDAN-SE-GAPSO-LSTM
Authors: Wu Shuai , Jiang He , Gao Qingzhong
Published: March 2024

This study proposes an improved adaptive noise-complete ensemble empirical mode decomposition (ICEEMDAN), sample entropy (SE), and genetic particle swarm optimization (GAPSO) algorithm-based short-term solar power forecast model. The photovoltaic power data is first decomposed using the ICEEMDAN algorithm to produce a number of eigenmode components with various properties. The sample entropy of each component is then calculated, and the components with similar sample entropy values are combined to create new modal components. These new modal components are then input into the GAPSO-optimized LSTM model for prediction, and the prediction results of each component are summed and reconstructed to produce the final prediction. The results completely validate the efficacy and dependability of the suggested method, using the measured data from a photovoltaic power station in Xinjiang, China as an example.
Facile synthesis of NiCo2 O4/rGO nanowire array electrodes for supercapacitor cathodes
Authors: Dong Chen , Wei Mingrui , Yang Lan , Liu Yihui
Published: March 2024

In this study, NiCo2O4/rGO nanowire arrays (NWAs) were effectively synthesized, and these arrays were subsequently employed as components in supercapacitors. The phase structure of the materials was analyzed using X-ray diffraction spectroscopy, and the morphology of the materials was observed by scanning and transmission electron microscopy. By comparing with NiCo2O4 nanowire arrays without graphene oxide, it was found that the surface of NiCo2O4 arrays grown directly on nickel foams had a large number of accumulations, whereas the surface agglomerations of NiCo2O4/rGO nanowire arrays complexed with reduced graphene oxide were significantly improved. The NiCo2O4/rGO electrode with improved agglomeration phenomenon shows better performance. The specific capacitance of NiCo2O4/rGO NWAs is 2311 F·g-1 at 1 A·g-1 and remains at 1211 F·g-1 even at 50 A·g-1. In addition, the capacitance retention of this material could reach 83.5 % after 3,000 cycles at 10 A·g-1, demonstrating excellent multiplicative performance and cycling stability.
Wind power anomaly data detection based on unsupervised methods
Authors: Zhang Hao , Tang Qingfeng , Xu Du , Li Xiaofei
Published: March 2024

During the actual operation of the wind turbine, a large number of abnormal data will be generated due to environmental or human factors, which will have a great impact on the condition assessment and output prediction. In order to make wind energy a reliable source of energy, it is very important to establish an efficient and accurate wind power detection model. Therefore, it becomes essential to identify abnormal data for a more precise evaluation of wind turbine performance. Based on the data mining clustering technology K-means algorithm, this paper introduces an unsupervised abnormal wind power detection algorithm combining the variational autoencoders (VAE) model. The focus of this abnormal wind power detection method is primarily on assessing the reconstruction error, which, in turn, generates an abnormality score for wind power data. This score is then used to determine the presence of abnormal wind power data. Finally, the wind power data in 2021 is tested.
Research on distributed photovoltaic power prediction method based on reinforcement learning
Authors: Wang Chengjing , Zhang Haitao , Chen Zhenxing
Published: March 2024

The distributed photovoltaic power prediction is of great significance for reasonably adjusting and optimizing the power generation plan in the dispatching system. When using machine learning algorithms to construct photovoltaic power prediction models, there are usually problems such as poor prediction accuracy under default hyperparameters and high cost of human experience parameter adjustment experiments. Therefore, a reinforcement learning algorithm based on the long short-term memory network model (SARSA-LSTM) is proposed. Firstly, the reinforcement learning SARSA algorithm is used to tune the hyperparameters of LSTM automatically. Then, the optimal hyperparameter combination is used for regression prediction of photovoltaic power. The experiment compared the model results under default hyperparameters, Bayesian optimization, and grid search optimization hyperparameters. The results showed that the SARSA-LSTM proposed in this paper has better training efficiency and prediction performance compared to other models, which can meet the needs of practical prediction applications.
Application of magnetic flux leakage method in the crimping inspection of carbon fiber conductor
Authors: Zhang Hang , Du Zhiye , Liu Yazhi
Published: March 2024

Compared with steel core aluminum strand wire, carbon fiber composite core wire has many excellent characteristics such as large flow capacity, good heat resistance, light weight, but its mechanical properties are poor, and the unqualified crimping quality is easy to lead to wire breakage accidents, which greatly affects its popularization. For this reason, a scheme for the detection of crimping defects of carbon fiber composite mandrel based on magnetic leakage method is proposed. Firstly, the finite element analysis model of the clamping fixture was established, and then the magnetic pole distance k and radial air gap n of the magnetic leakage testing device were explored. Based on the signal-to-noise ratio under the two typical defect conditions of fracture and low pressure, the most suitable excitation structure parameters of the magnetic leakage device were obtained. The results show that when k=55mm and n=3.5mm, the signal-to-noise ratio of MFL detection device reaches the best effect. The research results are of great significance to the quality inspection of compacts of carbon fiber composite mandrel.
Combined navigation system for substation inspection robot based on DGPS/DR multi-sensor fusion
Authors: Yan Yu , Yu Xi , Liao Jianbin , Liu Liangyu , Gong Jie , Yang Yingwei
Published: March 2024

To realize the routine inspection work of the capacitor tower inspection operation robot on the capacitor tower in the substation, and to guarantee the accuracy and safety of the robot’s movement in the substation, a multi-sensor combination navigation system and the corresponding Kalman fusion filter are designed. Combined with the overall structure of the substation and the working environment of the inspection robot, the navigation and positioning requirements of the robot are analyzed and compared, and the multi-sensor combination positioning technology using a combination of DGPS, attitude sensors and velocity sensors is determined. The Kalman fusion filter based on the constant velocity model is used to fuse the positioning information of multiple sensors, and more accurate and reliable navigation information is obtained compared with the single-sensor positioning system. According to the working environment of the substation, an outdoor planar robot mobile navigation experiment is carried out to collect the positioning information of multiple sensors and carry out data fusion processing to verify the accuracy and robustness of multi-sensor combination navigation and positioning.
Protection adaptability analysis method for photovoltaic grid-connected generating system
Authors: Chen Yongxin , Liu Zhichang , Yang Zengli , Yin Xianggen , Wang Jing , Zhang Kanjun , Li Hengxuan , Yao Wei
Published: March 2024

Inverter power sources such as photovoltaic inverters and SVG have unique fault characteristics compared to traditional synchronous motors due to their unique power generation methods, circuit topology, and low-voltage traversal control strategies. The power grid faces various adverse effects due to the ongoing expansion of photovoltaic power station (PV power station) capacity. How to comprehensively analyze the impact of photovoltaic power stations above 1000 MW on power grid relay protection has become a problem. Therefore, a protection adaptability analysis method for photovoltaic grid-connected generating systems is proposed, which is suitable for engineering analysis before the connection of large-capacity PV power stations to ensure the safety of the power system. And it is found that current differential protection exhibits better adaptability than distance protection.
AC-DC breakdown characteristics of oil-paper insulation at low temperature
Authors: Zhang Jinfeng , Han Guozheng , Hao Lingyan
Published: March 2024

New energy sources such as wind energy are mainly distributed in low temperature areas such as high altitude and high dimensionality in inland China, which has higher requirements for the low-temperature insulation characteristics of power equipment. This poses higher demands for the low-temperature insulation capabilities of power equipment. However, the existing research on the low temperature breakdown characteristics of oil-impregnated paper is limited. In this study, the authors constructed an AC-DC combined power supply and a specialized low-temperature breakdown testing platform. Various oil-impregnated paper samples with different moisture contents were prepared. The paper investigated the AC-DC breakdown characteristics of these samples under low-temperature conditions, focusing on the effects of temperature, moisture content, and DC component on the breakdown strength. The findings serve as a valuable design reference for the application of oil-impregnated power equipment in low-temperature environments.
An accelerated modelling method of full-bridge modular multilevel converter considering dead-time
Authors: Pan Keying , Jing Hang , Xu Jianzhong , Li Fucun , Zhang Yan , Sun Yuntao
Published: March 2024

To avoid short-circuits of the same side switching of power converters, the dead time is of significance in the pulse trigger gating signal for full bridge modular multilevel converter (FB-MMC). However, the previous equivalent models use the binary resistance switching model to equivalent the switching state which is impossible to simulate the switching with dead time, and the detailed model (DM) with higher levels is time-consuming and inefficient in electromagnetic transient (EMT) simulation. To address this problem, based on the state-space averaging method, a speed-up average value model (AVM) of FB-MMC considering dead time is proposed. Firstly, the working state of FB-MMC is obtained through analysing the switching states with dead time and is classified into three cases according to the capacitor. Secondly, derived from state-space equation, the three cases are integrated into a unified model by introducing the duty cycle, and then the equivalent controlled source is used as the interface circuit between the external grid and capacitor. Finally, a 49-level two-terminal MMC-HVDC system consisting of FB-MMC is constructed in PSCAD / EMTDC simulations, showing that the proposed AVM compared with DM has high accuracy and operation efficiency.