bluuebunny/crossref_metadata_2025 huggingface dataset:
Whistler Waves Above the Lower Hybrid Frequency in the Ionosphere and Their Counterparts in the Magnetosphere
Authors: Xia Zhiyang , Chen Lunjin , Horne Richard B. , Bortnik Jacob
Published: April 2022

In this study, we report the statistical properties of whistler mode lower hybrid (LH) emissions in the ionosphere, which have structureless spectra with a lower frequency boundary that matches the variation of the local lower hybrid resonance frequency fLHR. A potential source for the LH emissions is identified as the high‐frequency plasmaspheric hiss (HFPH) in the magnetosphere. We use Detection of Electromagnetic Emissions Transmitted from Earthquake Regions and Van Allen Probes data to perform a statistical study of the wave power distribution of the LH emissions and HFPH. Both LH and HFPH emissions show a similar frequency range, a similar invariant magnetic latitude range, and have similar trends in magnetic local time (stronger wave intensity on the dayside) and in the auroral electrojet (AE) index (stronger wave intensity for higher AE condition). A ray tracing simulation is also performed to demonstrate the propagation of HFPH waves from the magnetosphere into the ionosphere as LH waves.
Using VLF Transmitter Signals at LEO for Plasmasphere Model Validation
Authors: Usanova M. E. , Reid R. A. , Xu W. , Marshall R. A. , Starks M. J. , Wilson G. R.
Published: April 2022

This study presents analysis of very low frequency (VLF) transmitter signal measurements on the Very‐Low‐Frequency Propagation Mapper (VPM) CubeSat in low‐Earth orbit. Six months of satellite operation provided good data coverage, used to build global statistical maps of VLF power distribution. The power distribution above four powerful transmitters is used as input for ray tracing to study signal propagation to the conjugate hemisphere in two plasmaspheric density models. The ray tracing results are further compared with VPM measurements to determine which model provides better agreement with observations. As ray propagation largely depends on the background plasma density distribution, this indirect method can be used for plasmaspheric density model validation as an alternative to multipoint in situ plasma measurements that may not be readily obtainable. In addition, it can be used to investigate Landau damping and ducted versus non‐ducted propagation of VLF signals.
Astrocytes derived from ASD individuals alter behavior and destabilize neuronal activity through aberrant Ca2+ signaling
Authors: Allen Megan , Huang Ben S. , Notaras Michael J. , Lodhi Aiman , Barrio-Alonso Estibaliz , Lituma Pablo J. , Wolujewicz Paul , Witztum Jonathan , Longo Francesco , Chen Maoshan , Greening David W. , Klann Eric , Ross M. Elizabeth , Liston Conor , Colak Dilek
Published: April 2022

The cellular mechanisms of autism spectrum disorder (ASD) are poorly understood. Cumulative evidence suggests that abnormal synapse function underlies many features of this disease. Astrocytes regulate several key neuronal processes, including the formation of synapses and the modulation of synaptic plasticity. Astrocyte abnormalities have also been identified in the postmortem brain tissue of ASD individuals. However, it remains unclear whether astrocyte pathology plays a mechanistic role in ASD, as opposed to a compensatory response. To address this, we combined stem cell culturing with transplantation techniques to determine disease-specific properties inherent to ASD astrocytes. We demonstrate that ASD astrocytes induce repetitive behavior as well as impair memory and long-term potentiation when transplanted into the healthy mouse brain. These in vivo phenotypes were accompanied by reduced neuronal network activity and spine density caused by ASD astrocytes in hippocampal neurons in vitro. Transplanted ASD astrocytes also exhibit exaggerated Ca2+ fluctuations in chimeric brains. Genetic modulation of evoked Ca2+ responses in ASD astrocytes modulates behavior and neuronal activity deficits. Thus, this study determines that astrocytes derived from ASD iPSCs are sufficient to induce repetitive behavior as well as cognitive deficit, suggesting a previously unrecognized primary role for astrocytes in ASD.
5-Aminolevulinic acid overcomes hypoxia-induced radiation resistance by enhancing mitochondrial reactive oxygen species production in prostate cancer cells
Authors: Owari Takuya , Tanaka Nobumichi , Nakai Yasushi , Miyake Makito , Anai Satoshi , Kishi Shingo , Mori Shiori , Fujiwara-Tani Rina , Hojo Yudai , Mori Takuya , Kuwada Masaomi , Fujii Tomomi , Hasegawa Masatoshi , Fujimoto Kiyohide , Kuniyasu Hiroki
Published: April 2022

Background

The naturally occurring amino acid 5-aminolevulinic acid (5-ALA) is a precursor of protoporphyrin IX (PpIX) biosynthesised in the mitochondria. When accumulated PpIX is excited by light (wavelength of 625–635 nm), reactive oxygen species (ROS) are generated. Here, we investigated whether 5-ALA may increase the sensitisation of prostate cancer (PCA) cells to radiotherapy through the generation of ROS via its metabolite, PpIX.

Methods

Effect of 5-ALA on PC-3 and DU-145 PCA cell lines treated with ionising radiation (IR) was examined in vitro and in vivo with assessment by clonogenic assay, mitochondrial function and ROS production under normoxia or hypoxia condition.

Results

5-ALA enhanced intra-mitochondrial ROS production immediately after exposure to IR and decreased mitochondrial membrane potential via increase of intra-cellular PpIX. IR with 5-ALA induced mitochondrial dysfunction and increased ATP production, switching energy metabolism to the quiescence. Under hypoxic condition, ROS burst and mitochondrial dysfunction were induced by IR with 5-ALA resulting reducing cancer stemness and radiation resistance.

Conclusion

These results suggest that combined therapy with 5-ALA and radiation therapy is a novel strategy to improve the anti-cancer effects of radiation therapy for PCA.
Precise orientation control of a liquid crystal organic semiconductor via anisotropic surface treatment
Authors: Han Moon Jong , Wei Dayan , Yun Hee Seong , Lee Seong-hun , Ahn Hyungju , Walba David M. , Shin Tae Joo , Yoon Dong Ki
Published: April 2022

We report a three-dimensional (3D) molecular orientation control of a liquid crystal organic semiconductor (LC-OSC) based on the long-range ordering characteristic of an LC material. To this end, a synthetic LC-OSC molecule, MeOPh-BTBT-C8, with a fluidic nematic (N) phase that is essential for alignment control over a large area and a smectic E (SmE) phase showing high ordering, was prepared. A simple flipping of a sandwich cell made of the LC-OSC material between the top and bottom substrates that have uniaxial–planar degenerated alignment as well as crossed rubbing directions responds to the given surface anchoring condition and temperature gradient. Optical observation of the alignment-controlled LC-OSC was carried out by polarized optical microscopy (POM), and the corresponding charge carrier mobility was also measured by fabricating organic field-effect transistors (OFETs). Our platform offers a facile approach for multidirectional and multifunctional organic electronic devices using the stimulus–response characteristics of LC materials.
Hydrogen isotope effect on self-organized electron internal transport barrier criticality and role of radial electric field in toroidal plasmas
Authors: Kobayashi T. , Shimizu A. , Nishiura M. , Ido T. , Satake S. , Tokuzawa T. , Ii Tsujimura T. , Nagaoka K. , Ida K.
Published: April 2022

Self-organized structure formation in magnetically confined plasmas is one of the most attractive subjects in modern experimental physics. Nonequilibrium media are known to often exhibit phenomena that cannot be predicted by superposition of linear theories. One representative example of such phenomena is the hydrogen isotope effect in fusion plasmas, where the larger the mass of the hydrogen isotope fuel is the better the plasma confinement becomes, contrary to what simple scaling models anticipate. In this article, threshold condition of a plasma structure formation is shown to have a strong hydrogen isotope effect. To investigate the underlying mechanism of this isotope effect, the electrostatic potential is directly measured by a heavy ion beam probe. It is elucidated that the core electrostatic potential transition occurs with less input power normalized by plasma density in plasmas with larger isotope mass across the structure formation. This observation is suggestive of the isotope effect in the radial electric field structure formation.
Metformin is associated with favorable outcomes in patients with COVID-19 and type 2 diabetes mellitus
Authors: Ma Zhiyuan , Patel Nishit , Vemparala Pranathi , Krishnamurthy Mahesh
Published: April 2022

Coronavirus disease 2019 (COVID-19) is a new pandemic the entire world is facing since December of 2019. Several risk factors are identified in developing severe disease and one of which is preexisting type 2 diabetes mellitus. Metformin is known to have host-directed anti-viral and anti-inflammatory properties. However, whether these effects offer lower mortality remains unclear. In this retrospective study, we aim to address whether metformin use prior to admission decreases mortality in patients with COVID-19 and pre-existing type 2 diabetes mellitus. A total of 1356 hospitalized patients with COVID-19 and pre-existing type 2 diabetes mellitus was analyzed by multivariable regression. Covariates that potentially confound the association were further adjusted using propensity score matching or inverse probability of treatment weighting. We found that metformin therapy prior to admission in patients with COVID-19 and type 2 diabetes mellitus was significantly associated with less primary outcome events including in-hospital mortality and hospice care enrollment with an odds ratio (OR) of 0.25 (95% CI 0.06–0.74) and less in-hospital length of stay, compared to the non-metformin group. Our results provide supporting evidence that metformin may confer increased survival in patients with COVID-19 and type 2 diabetes mellitus treated with metformin prior to hospitalization.
Helicity-dependent dissociative tunneling ionization of CF4 in multicycle circularly polarized intense laser fields
Authors: Fujise H. , Uemura M. , Hasegawa H. , Ikeya D. , Matsuda A. , Morishita T. , Madsen L. B. , Jensen F. , Tolstikhin O. I. , Hishikawa A.
Published: April 2022

Three-dimensional electron–ion coincidence momentum imaging reveals that the dissociative tunneling ionization of tetrafluoromethane (CF4) is sensitive to the helicity of the circularly polarized laser fields.
A novel and portable electrochemical sensor for 5-hydroxymethylfurfural detection using silver microdendrite electrodeposited paper-based electrode
Authors: Upan Jantima , Lerdsri Jamras , Soongsong Jittrapun , Mool-am-kha Pijika , Sridara Tharinee , Reanpang Preeyaporn , Jakmunee Jaroon
Published: April 2022

A lab-made screen-printed carbon electrode was fabricated on poster paper and modified with silver microdendrites for the determination of 5-hydroxymethylfurfural in honey.
A guanidino-γ-cyclodextrin superdimer generates a twin receptor for phosphate dimers assembled by anti-electrostatic hydrogen bonds
Authors: Saridakis Emmanuel , Kasimati Eleni-Marina , Yannakopoulou Konstantina , Mavridis Irene M.
Published: April 2022

In aqueous phosphate solutions, per(6-guanidino)-γ-cyclodextrin forms a dimer-within-a-dimer via successive dimerisation steps. The resulting supermolecules are ideal receptors for phosphate dimers.
Efficient ammonia synthesis via electroreduction of nitrite using single-atom Ru-doped Cu nanowire arrays
Authors: Tran Ngoc Quang , Duy Le Thai , Truong Dai Cao , Nguyen Le Bao Thu , Phan Bach Thang , Cho Yunhee , Liu Xinghui , Lee Hyoyoung
Published: April 2022

Isolated Ru single-atoms on a Cu nanowire array on a three-dimensional copper foam electrode were synthesized for the highly active and selective electrocatalytic reduction of NO2− ions to value-added NH3.
An AIE fluorescent sensor for rapid and selective detection of phosgene
Authors: Da-xue Li , Dan Li , Liang Zong , Yan-hua Xiao , Shao-hui Sui , Bo Zhuang , Rui Li , Hong-ling Zhen , Jian Li , Zhi-ping Huang , Zhi-gang Jiang , Wei-hui Wu
Published: April 2022

Herein, a sensor of TPE-phos has been rationally designed for phosgene detection via formation of TPE-CN and an AIE fluorescence ‘light-up’.
Effect of Na+ and K+ on the cucurbituril-mediated hydrolysis of a phenyl acetate
Authors: Rad Nazar , Sashuk Volodymyr
Published: April 2022

Cucurbit[7]uril accelerates acid hydrolysis and screens the reaction centre from the neighbouring group. The coordination of alkali metal cations to the macrocycle portal uncompetitively reduces the catalytic activity.
One-step side-by-side 3D printing constructing linear full batteries
Authors: Ding Junwei , Zheng Huaiyang , Ji Xiaoyan
Published: April 2022

A universal one-step side-by-side 3D printing approach to construct linear full batteries on different substrates is proposed. This work provides a new strategy to design different linear full batteries with high performance.
Correction: Enhanced ionic conduction in composite polymer electrolytes filled with plant biomass “lignin”
Authors: Liu Zitong , Shikinaka Kazuhiro , Otsuka Yuichiro , Tominaga Yoichi
Published: April 2022

Correction for ‘Enhanced ionic conduction in composite polymer electrolytes filled with plant biomass “lignin”’ by Zitong Liu et al., Chem. Commun., 2022, DOI: 10.1039/d1cc07148c.
Correction: Enabling methanol oxidation by an interacting hybrid nanosystem of spinel Co3O4 nanoparticle decorated MXenes
Authors: Baruah Kashmiri , Deb Pritam
Published: April 2022

Correction for ‘Enabling methanol oxidation by an interacting hybrid nanosystem of spinel Co3O4 nanoparticle decorated MXenes’ by Kashmiri Baruah et al., Dalton Trans., 2022, 51, 4324–4337, DOI: 10.1039/D1DT03671H.
Coal-derived graphene quantum dots with a Mn2+/Mn7+ nanosensor for selective detection of glutathione by a fluorescence switch-off–on assay
Authors: Kundu Aayushi , Maity Banibrata , Basu Soumen
Published: April 2022

Coal derived GQDs-Mn2+/Mn7+ nanosensor for the sensitive detection of GSH.
Identifying molecular fluorophore impurities in the synthesis of low-oxygen-content, carbon nanodots derived from pyrene
Authors: Kothalawala Nadeesha L. , Kim Sang Won , Kim Namhee , Henderson Collan J. , Seol Minsu , Yang Fuqian , Kwak Seung-Yeon , Hwang Kyu Young , Son Won-Joon , Shin Hyeon-Jin , Choi Hyeonho , Kim Byeong-Su , Kim Doo Young
Published: April 2022

Determination of the formation of bright molecular fluorphores during the synthesis of pyrene-derived CNDs, through extensive separation and systematic characterization.
CO2 uptake prediction of metal–organic frameworks using quasi-SMILES and Monte Carlo optimization
Authors: Ahmadi Shahin , Ketabi Sepideh , Qomi Mahnaz
Published: April 2022

The first report of quasi-SMILES-based QSPR models for CO2 capture of MOFs based on experimental data.
Cocrystallization tailoring radiative decay pathways for thermally activated delayed fluorescence and room-temperature phosphorescence emission
Authors: Liu Kun , Li Shuai , Fu Liyuan , Lei Yilong , Liao Qing , Fu Hongbing
Published: April 2022

We achieve TADF or dual-emissive TADF/RTP by tailoring the substitution positions of bromine atoms in binary organic D–A-type CT cocrystals, which offers a wonderful insight in modulating radiative decay pathways of organic CT cocrystals.
Characterizing North Carolina's Deaf and Hard of Hearing Infants and Toddlers: Predictors of Vocabulary, Diagnosis, and Intervention
Authors: Campbell Erin , Bergelson Elika
Published: April 2022

Purpose:

This study sought to (a) characterize the demographic, audiological, and intervention variability in a population of Deaf and Hard of Hearing (DHH) children receiving state services for hearing loss; (b) identify predictors of vocabulary delays; and (c) evaluate factors influencing the success and timing of early identification and intervention efforts at a state level.

Method:

One hundred DHH infants and toddlers (aged 4–36 months) enrolled in early intervention completed the MacArthur–Bates Communicative Development Inventories, and detailed information about their audiological and clinical history was collected. We examined the influence of demographic, clinical, and audiological factors on vocabulary outcomes and early intervention efforts.

Results:

We found that this sample showed spoken language vocabulary delays (production) relative to hearing peers and showed room for improvement in rates of early diagnosis and intervention. These delays in vocabulary and early support services were predicted by an overlapping subset of hearing-, health-, and home-related variables.

Conclusions:

In a diverse sample of DHH children receiving early intervention, we identify variables that predict delays in vocabulary and early support services, which reflected
both
dimensions that are immutable, and those that clinicians and caretakers can potentially alter. We provide a discussion on the implications for clinical practice.

Supplemental Material:

https://doi.org/10.23641/asha.19449839
Deep image retrieval using artificial neural network interpolation and indexing based on similarity measurement
Authors: Ahmad Faiyaz
Published: April 2022

In content‐based image retrieval (CBIR), primitive image signatures are critical because they represent the visual characteristics. Image signatures, which are algorithmically descriptive and accurately recognized visual components, are used to appropriately index and retrieve comparable results. To differentiate an image in the category of qualifying contender, feature vectors must have image information's like colour, objects, shape, spatial viewpoints. Previous methods such as sketch‐based image retrieval by salient contour (SBIR) and greedy learning of deep Boltzmann machine (GDBM) used spatial information to distinguish between image categories. This requires interest points and also feature analysis emerged image detection problems. Thus, a proposed model to overcome this issue and predict the repeating pattern as well as series of pixels that conclude similarity has been necessary. In this study, a technique called CBIR‐similarity measure via artificial neural network interpolation (CBIR‐SMANN) has been presented. By collecting datasets, the images are resized then subject to Gaussian filtering in the pre‐processing stage, then by permitting them to the Hessian detector, the interesting points are gathered. Based on Skewness, mean, kurtosis and standard deviation features were extracted then given to ANN for interpolation. Interpolated results are stored in a database for retrieval. In the testing stage, the query image was inputted that is subjected to pre‐processing, and feature extraction was then fed to the similarity measurement function. Thus, ANN helps to get similar images from the database. CBIR‐SMANN have been implemented in the python tool and then evaluated for its performance. Results show that CBIR‐SMANN exhibited a high recall value of 78% with a minimum retrieval time of 980 ms. This showed the supremacy of the proposed model was comparatively greater than the previous ones.
Advanced orthogonal opposition‐based learning‐driven dynamic salp swarm algorithm: Framework and case studies
Authors: Wang Zongshan , Ding Hongwei , Yang Jingjing , Wang Jie , Li Bo , Yang Zhijun , Hou Peng
Published: April 2022

Salp swarm algorithm (SSA) is a relatively new bio‐inspired meta‐heuristic optimization algorithm that mimics the navigating and foraging behavior of salps in oceans. This paper presents an orthogonal quasi‐opposition‐based learning‐driven dynamic SSA (OBDSSA) for solving global optimization problems. The proposed methodology integrates orthogonal quasi‐opposition‐based learning (OQOBL) tactic and dynamic learning (DL) strategy with SSA to improve its performance. The OQOBL technique is used to enrich the exploration and development capability of the canonical SSA to help the salp chain jump out of local optimum, while the DL mechanism is applied to the basic approach to expand the neighborhood searching capabilities of the search agents. To investigate the proposed operators and OBDSSA algorithm, 18 widely used benchmark functions and parameter extraction problem of photovoltaic (PV) model have been experimented upon. The comparisons reveal that OBDSSA outperforms all competitors, including the standard SSA, SSA variants, and other state‐of‐the‐art algorithms. Finally, the developed approach is applied to path planning and obstacle avoidance (PPOA) tasks in autonomous mobile robots (AMR) and satisfactory results are obtained.
Event‐triggered H∞$\mathcal {H}_\infty$ synchronization of directed and switched coupled stochastic delayed neural networks with multi‐weights
Authors: Lin Shanrong , Liu Xiwei , Huang Yanli
Published: April 2022

This essay is devoted to studying synchronization problem of directed and switched coupled stochastic delayed neural networks with multi‐weights (SCSDNNMWs) via designing a novel event‐triggered protocol. The proposed model is based on stochastic delayed neural network with directed coupling, and multiple coupling matrices with switching express intricate and changing communication channels. Since the external disturbances are likely to cause network topologies change, fixed and accurate values of coupling matrices are difficult to obtain, while the above model has more advantages of characterizing this real network. Besides, zero eigenvalue of different coupling matrices are represented by the corresponding normalized left eigenvectors (NLEVec), which is hard to establish yet especially when designing necessary Lyapunov functions. The authors' essay deduces that if the Chebyshev distance among NLEVec of multiple coupling matrices is less than a permissible deviation limit based on a weighted set of these NLEVec, then several event‐triggered synchronization and synchronization criteria are established. The effectiveness of these results are verified by several given examples.
An equilibrium‐based model to investigate market performance of power‐based electricity market
Authors: Rahmati Iman , Akbari Foroud Asghar
Published: April 2022

The conventional model of the day‐ahead electricity markets employs an energy‐based approach to manage the competition among the players. Under this format, it is assumed that everything (including the demand and output power of the generating units) is constant during each hour. This assumption greatly simplifies the market, and it is widely incorporated over the globe. However, it leads to mismatches in the real‐time operation. With the increase in the share of intermittent sources, such mismatches get higher amplitude and become more threatening for market performance and system security. Power‐based modelling of the electricity market (PbM), which has been introduced as a remedy to eliminate mismatches in real‐time operation, has been scrutinized. The previous comparisons between the conventional model and PbM generally deploy a rigid approach based on the existence of perfect competition. They assume that all the generation companies offer their maximum capacity and marginal cost into the market. Moreover, they model a single‐side auction in which only the supply side is actively involved in the market. In order to develop the previous studies on PbM, an equilibrium environment to model the players’ interactions within a competitive market has been employed. Employment of an equilibrium model brings the benefits of modelling a double‐side market and can simulate the strategic behaviour of the market players on both sides within a partially competitive electricity market. The equilibrium model provides empirical insight on how changing the market structure to PbM affects players’ behaviour and shifts the market equilibrium and provided some unreported attributes of PbM. The study is based on a real‐world network of the Gilan province in northern Iran.
Special transformer sharing mode: Utilizing special transformers of buildings to supply power for charging stations
Authors: Zhang Yongjun , Yang Jingxu , Li Qinhao , Deng Wenyang , Xie Xiaoyu
Published: April 2022

In view of the limited capacity for public transformers to accept electric vehicles (EVs) and the large cost of putting in new transformers to supply power in the parking lot of urban buildings, a special transformer sharing mode (STSM) is proposed, where charging station operators utilize the special transformers of buildings to supply power for charging stations. To enhance the applicability of STSM, single regulation and joint regulation methods for the charging price strategy of charging stations are put up, and the mathematical model of joint regulation is focused on. First of all, a joint regulation mechanism is established, in which EVs are guided to charge off‐peak and off‐station through the joint regulation. Secondly, integrating charging fees, queuing costs, and transfer costs, the equivalent charging prices for EV users are put forward. Based on the difference of the equivalent charging prices, transfer probability model for EVs’ charging periods and charging stations is proposed. Furthermore, the overall objective of joint regulation is built based on the net income of all parties. And an optimization method for the joint regulation of charging prices is proposed. Then, regulation lifting ratio is put forward to reflect the superiority of joint regulation over single regulation. Based on this, an evaluation model for joint station diameter threshold is established. The practical result proves that through single regulation and joint regulation, approximately 200–500 additional EVs can be powered, which will result in significant savings in infrastructure construction and investment costs.
A new passive islanding detection technique for a microgrid based on transient energy
Authors: Hasan Saady , Saleh Sherif S.
Published: April 2022

A new passive islanding detection technique based on transient energy that is measured and analysed at targeted distributed generation (DG) or the point of common coupling (PCC) is presented. The proposed technique measures the superimposed components and then calculates the transient active energy (TAE) and the transient reactive energy (TRE). Using the relation between TAE and the TRE, the relay can determine the islanding situation even in a worst‐case operational scenario, and this is a notably shorter response time according to the current standards. The performance of the proposed technique is simulated in the MATLAB environment. Islanding and non‐islanding scenarios for different power match conditions and types of DGs are simulated. The evaluation of the simulation results shows that the proposed technique identifies the islanding with a less than zero power mismatch, operates accurately under the condition of load variation, and does not conflict with the power system operation during normal conditions. It removes the passive technique drawbacks by having a tiny non‐detection zone (NDZ) and a faster response.
Improvement of voltage adaptability for decentralised doubly‐fed induction generator wind power system based on nine‐switch converter
Authors: Hu Zhishuai , Ren Yongfeng , He Jinwei , Xue Yu , Yun Pingping
Published: April 2022

This paper proposes a method to improve the voltage adaptability of doubly fed induction generator (DFIG) wind turbines in a decentralised scenario by incorporating a nine‐switch converter (NSC). With the proposed scheme, the DFIG can realise low voltage ride‐through (LVRT) and continuous operation under the grid voltage harmonic, drop, and rise. The topology of the NSC‐DFIG system is introduced and is used to solve the circuit model. Control strategies for voltage compensation and current compensation are based on the circuit model. The corresponding voltage compensation scheme and the NSC DC voltage control scheme were designed according to the specific capacity configuration of the NSC in this study. To reduce the DC‐side voltage of the NSC, a third harmonic‐injection modulation method and a dynamic modulation ratio allocation strategy were incorporated. Simulations under four power grid voltage conditions were used to validate the scheme. This method can improve the voltage adaptability for decentralised DFIG wind power systems, which can enable their successful interactions with the power grid.
Multi‐target pair‐matching method based on angle information in transmit/receive‐receive synergetic High Frequency Surface Wave Radar
Authors: Bai Yang , Wu Xiaochuan , Deng Weibo , Zhang Xin
Published: April 2022

In the past few decades, the target location methods in transmit/receive‐receive (T/R‐R) synergetic High Frequency Surface Wave Radar (HFSWR) have received extensive attention from the signal processing community. However, there are few studies on the method of parameter pair‐matching for multi‐target scene. In this paper, a computationally efficient multi‐target pair‐matching method based on angle information only in T/R‐R synergetic HFSWR is developed. The proposed method is realised by dealing with three vectors composed of the first column, the first row and diagonal entries of the correlation matrix, instead of performing the singular value decomposition (SVD) of the correlation matrix. Simultaneously, the proposed method is a computationally efficient subspace algorithm, which only uses the angle information to complete the purpose of multi‐target pair‐matching. The simulation results are presented to demonstrate the effectiveness of the proposed method.
Discovery of a thin lithium plateau among metal-poor red giant branch stars
Authors: Mucciarelli A. , Monaco L. , Bonifacio P. , Salaris M. , Deal M. , Spite M. , Richard O. A. , Lallement R.
Published: April 2022

The surface lithium abundance, A(Li), of warm metal-poor dwarf stars exhibits a narrow plateau down to [Fe/H] ~ −2.8 dex, while at lower metallicities the average value drops by 0.3 dex with a significant star-by-star scatter (called ‘lithium meltdown’). This behaviour is in conflict with predictions of standard stellar evolution models calculated with the initial A(Li) provided by the standard Big Bang nucleosynthesis. The lower red giant branch (LRGB) stars provide a complementary tool to understand the initial A(Li) distribution in metal-poor stars. We have collected a sample of high-resolution spectra of 58 LRGB stars spanning a range of [Fe/H] between ~−7.0 dex and ~−1.3 dex. The LRGB stars display an A(Li) distribution that is clearly different from that of the dwarfs, without signatures of a meltdown and with two distinct components: (a) a thin A(Li) plateau with an average A(Li) = 1.09 ± 0.01 dex (σ= 0.07 dex) and (b) a small fraction of Li-poor stars with A(Li) lower than ~0.7 dex. The A(Li) distribution observed in LRGB stars can be reconciled with an initial abundance close to the cosmological value by including an additional chemical element transport in stellar evolution models. The required efficiency of this transport allows us to also match the Spite plateau lithium abundance measured in the dwarfs. The emerging scenario is that all metal-poor stars formed with the same initial A(Li), but those that are likely the product of coalescence or that experienced binary mass transfer show lower A(Li). We conclude that the A(Li) in LRGB stars is qualitatively compatible with the cosmological A(Li) value and that the meltdown observed in dwarf stars does not reflect a real drop in the abundance at birth.
Ligament reconstruction using a semitendinosus tendon graft for proximal tibiofibular joint disorder: Case report
Authors: Okubo Atsushi , Kajikawa Yoshiteru , Nakajima Shun , Watanabe Nobuyoshi , Yotsumoto Tadahiko , Oshima Yasushi , Iizawa Norishige , Majima Tokifumi
Published: April 2022

We report our case of ligament reconstruction for treatment of proximal tibiofibular joint disorder using a semitendinosus tendon graft. A 21-year-old male college soccer player with no remarkable history of injury had been suffering from pain at the lateral aspect of the left knee when playing soccer. At another hospital, the patient was diagnosed with a lateral meniscus injury and cartilage injury of the external condyle of the tibia and underwent partial resection of the meniscus and bone drilling. However, his symptoms continued, and he was referred to our institution. Instability of the left proximal tibiofibular joint and pain were noted during weight-bearing dorsiflexion of the ankle. We diagnosed the case as a proximal tibiofibular joint disorder and surgically treated it by dissecting the proximal portion of the semitendinosus tendon, creating one transfibular and two transtibial tunnels, and then reconstructing the proximal tibiofibular ligament using the harvested semitendinosus tendon graft. The patient was allowed to run at postoperative 2 months, with no pain occurring while squatting at postoperative 3 months, subsequently resuming soccer at postoperative 8 months. The proximal tibiofibular joint disorder is a relatively rare pathology, and diagnosis and conservative treatment are often difficult. Although various surgical treatments are known, the clinical outcome of our case has been successful after reconstructing the anterior and posterior proximal tibiofibular ligaments using a semitendinosus tendon graft.
Women’s work on small change: privately issued currency by women in mid-17th century London
Authors: Ben-Or Idit
Published: April 2022

This paper focuses on privately issued currencies by women in mid-17th century London. These currencies appeared across England as part of a large wave of minting which began during the English Civil War as a result of severe shortages of low value coinage (‘small change’), used for purposes of petty trade. In London alone over 4200 tradesmen and businesses issued tokens, only around 140 of these issuers were women. The tokens are a rare visual and material source on the daily life of working women and their self-representation. By contextualizing the issuers’ occupations and token designs within the history of women’s legal status, this paper will demonstrate that token issuers were likely not under the status of married women. The paper examines who these women issuers were, their occupations, and the legal status that enabled them to become independent active agents within the new commercial sphere of tokens. The paper will demonstrate that the artifact of tokens issued by women is extraordinary within the phenomenon, though the line of work these women did was not unique in the period. The ability of women to represent themselves on a token was likely a direct result of their legal status and the commercial rights it entailed.
Characterizing speed of sound in the spine for focused ultrasound
Authors: Piccone Ashley
Published: April 2022

Ultrasound therapeutic techniques in vertebrae will need to account for the different bone microstructure
Time-dependent quantum wave packet calculation for reaction S−(2P)+H2(1Σg+)→SH−(1Σ)+H(2S) on ab Initio potential energy surface
Authors: Ma Hong-yu , Zhang Cheng-yuan , Song Yu-zhi , Ma Feng-cai , Li Yong-qing
Published: April 2022

The time-dependent wave packet propagation method was applied to investigate the dynamic behaviours of the reaction S−(2P)+H2(1Σg+)→SH−(1Σ)+H(2S) based on the electronic ground state (2A′) potential energy surface of the SH2− ionic molecule. The collision energy dependent reaction probabilities and integral cross sections are obtained. The numerical results suggest that there are significant oscillation structures over all the studied range of the collision energies. The vibrational excitation and rotational excitation of the diatomic reagent H2 promote the reactivity significantly as suggested by the numerical total reaction probabilities with the initial rotational quantum number of j = 0, 2, 4, 6, 8, 10, and the vibrational quantum number v = 0, 1, 2, 3, 4. The numerical integral cross sections are quite consistent with the experimental data reported in previous work.
Full-dimensional potential energy surfaces of ground (X̃2 A′) and excited (Ã2 A″) electronic States of HCO and absorption spectrum
Authors: Chen Qixin , Han Shanyu , Hu Xixi , Xie Daiqian
Published: April 2022

In this work, high-fidelity full-dimensional potential energy surfaces (PESs) of the ground (X̃2 A′) and first doublet excited (Ã2 A″) electronic states of HCO were constructed using neural network method. In total, 4624 high-level ab initio points have been used which were calculated at Davidson corrected internally contracted MRCI-F12 level of theory with a quite large basis set (ACV5Z) without any scaling scheme. Compared with the results obtained from the scaled PESs of Ndengué et al., the absorption spectrum based on our PESs has slightly larger intensity, and the peak positions are shifted to smaller energy for dozens of wavenumbers. It is indicated that the scaling of potential energy may make some unpredictable difference on the dynamical results. However, the resonance energies based on those scaled PESs are slightly closer to the current available experimental values than ours. Nevertheless, the unscaled high-level PESs developed in this work might provide a platform for further experimental and theoretical photodissociation and collisional dynamic studies for HCO system.
Suppression of ambient temperature-caused drift in a laser power stabilization system with a liquid crystal variable retarder in atomic gyroscopes
Authors: Niu Yue , Duan Lihong , Zhang Jingxin , Huang Jiong , Zhai Yueyang , Quan Wei
Published: April 2022

Laser power stabilization systems with liquid crystal variable retarders have been employed in miniaturized atomic gyroscopes for the merits of low power consumption and easy integration. However, the long-term power drift of the system output with ambient temperature significantly decreases the long-term performance of atomic gyroscopes. Here, we demonstrated a method of dynamic closed-loop control based on the combination of optical power drift and ambient temperature modeling. For a continuous 45 min operation within an ambient temperature variation range of 23.7–25.3 °C, the relative Allan deviation of the output optical power was decreased by one order of magnitude from 2.29 × 10−4 to 3.35 × 10−5 after 100 s averaging time. The long-term stability of the system was significantly improved. In addition, the scheme requires no additional thermal control device, preventing the introduction of extra electromagnetic interference, which is desirable in a miniaturized atomic gyroscope.
Lost electron energy distribution of electron cyclotron resonance ion sources
Authors: Izotov I. , Skalyga V. , Tarvainen O.
Published: April 2022

To ensure further progress in the development of electron cyclotron resonance ion sources (ECRISs), deeper understanding of the underlying physics is required. The electron energy distribution (EED), which is crucial for the performance of an ECRIS, still remains obscure. The present paper focuses on the details of a well-developed technique of measuring the EED of electrons escaping axially from the magnetically confined plasma of an ECRIS. The method allows for better than 500 eV energy resolution over a range of electron energies from 4 keV to over 1 MeV. We present detailed explanation of the experimental procedure and the following data processing peculiarities with examples and discuss possible reasons of energetic electron losses from the magnetic trap, in particular the role of RF pitch angle scattering. Finally, an experimental method of approximating the confined EED based on the measurement of escaping electrons is described.
Numerical investigation of regimes of current transfer to anodes of high-pressure arc discharges
Authors: Santos D. F. N. , Almeida N. A. , Lisnyak M. , Gonnet J.-P. , Benilov M. S.
Published: April 2022

Unified 1D numerical modeling of high-pressure high-current arc discharges is revisited. Two regimes of current transfer to anodes are investigated. The “passive anode” regime occurs for low and moderate anode surface temperatures Ta. The energy flux from the plasma to the anode surface, qpl, depends on Ta rather weakly in this regime and may be conveniently expressed in terms of the local current density jc, and the so-called anode heating voltage Uh. Uh is independent of the arc length and the cathode surface temperature, although it weakly varies with jc between approximately 6 and 8.5 V for jc in the range from 105 to 108 A m−2. In the “active anode” regime, qpl is higher than in the passive anode regime and varies with Ta. The active anode regime may occur on hot refractory anodes, such as those of high-intensity discharge lamps, when Ta exceeds approximately 3000 K and the thermionic electron emission from the anode comes into play. The latter causes an increase in the electron density near the anode. One consequence is the increase in the electron energy transport from the bulk plasma to the near-anode layer by electron heat conduction. The other effect contributing to increase in qpl is the formation of a negative near-anode space-charge sheath with a positive voltage drop. In non-stationary simulations, the active regime occurs via the development of a thermal instability similar to that causing the appearance of spots on thermionic arc cathodes. The occurrence of the active regime is strongly affected by parameters, in particular, by the distance between the anode surface and the cooling fluid.
Adiabatic theory for the area-constrained Willmore flow
Authors: Zhang Jingxuan
Published: April 2022

In this paper, we develop an adiabatic theory for the evolution of large closed surfaces under the area-constrained Willmore (ACW) flow in a three-dimensional asymptotically Schwarzschild manifold. We explicitly construct a map, defined on a certain four-dimensional manifold of barycenters, which characterizes key static and dynamical properties of the ACW flow. In particular, using this map, we find an explicit four-dimensional effective dynamics of barycenters, which serves as a uniform asymptotic approximation for the (infinite-dimensional) ACW flow, so long as the initial surface satisfies certain mild geometric constraints (which determine the validity interval). Conversely, given any prescribed flow of barycenters evolving according to this effective dynamics, we construct a family of surfaces evolving by the ACW flow, whose barycenters are uniformly close to the prescribed ones on a large time interval (whose size depends on the geometric constraints of initial configurations).
Stochastic Ginzburg–Landau equation on a half-line driven by the multiplicative noise
Authors: Juarez-Campos B. , Kaikina E. I. , Vázquez-Esquivel A. V.
Published: April 2022

We consider the stochastic nonlinear Ginzburg–Landau equations driven by the multiplicative noise on the half-line with Neumann brown-noise boundary conditions. We establish the existence and uniqueness of a solution to an initial-boundary value problem with values in Sobolev space H1. We are also interested in the regularity behavior of the solution, especially near the origin, where the boundary data are highly irregular.
Simulation of primary current distribution in Tesla-type pulse generators
Authors: He Shi , Li Jun-na , Wang Yong-liang , Cui Guang-xi , Chen Xu-liang , Qiu Ai-ci
Published: April 2022

In a Tesla-type pulse generator, self-inductance of the primary coil is a crucial parameter to determine the final oscillating condition. However, the accurate value of this inductance might be changed due to the uneven primary current distribution caused by practical configuration of the primary side. Consequently, in order to precisely design the transformer, it is helpful to evaluate the primary inductance based on electromagnetic simulation instead of conventional approximate calculation. In this paper, a simulation model based on the finite integration technique is established to solve the uneven primary current problem. A primary coil with multiple contacting points is designed, and hexahedral mesh generation of the coil is also discussed. Hence, a series of verification tests using different primary structures are performed to support the results of simulation. Both results of the simulation model and the verification test presented that the variation of the primary inductance will affect the performance of the generator, and the number of contacting points is the main cause to determine the maximum current density of the coil.
Inverse Hartmann test for radius of curvature measurement in a corneal topography calibration sphere
Authors: Jalife-Chavira J. M. , Trujillo-Schiaffino G. , Mendoza-Villegas P. G. , Salas-Peimbert D. P. , Anguiano-Morales M. , Corral-Martínez L. F. , Tornero-Martínez N.
Published: April 2022

In this article, the use of a square Hartmann screen test to measure the radius of curvature of a corneal topography calibration test sphere is presented. The proposed technique is based on the image formation principle by specular reflection on convex reflective surfaces. Applying an inverse Hartmann test, a de-magnified virtual image (Hartmanngram) is obtained; considering their own scaled reference screen plate, a zonal wavefront retrieval approach is used and the radius of curvature obtained. Experimental setup along the obtained results is presented. A simulated spherical wavefront is used as a method to evaluate the error in the wavefront reconstruction. Since the measurements of radius of curvature fits in to ISO 10343, through suitable modifications the proposed method is potentially applicable in small F/# convex specular surfaces, as is the case in keratometry and corneal topography measurements.
Spin–vibronic coupling in the quantum dynamics of a Fe(III) trigonal-bipyramidal complex
Authors: Dakua Kishan Kumar , Rajak Karunamoy , Mishra Sabyashachi
Published: April 2022

The presence of a high density of excited electronic states in the immediate vicinity of the optically bright state of a molecule paves the way for numerous photo-relaxation channels. In transition-metal complexes, the presence of heavy atoms results in a stronger spin–orbit coupling, which enables spin forbidden spin-crossover processes to compete with the spin-allowed internal conversion processes. However, no matter how effectively the states cross around the Franck–Condon region, the degree of vibronic coupling, of both relativistic and non-relativistic nature, drives the population distribution among these states. One such case is demonstrated in this work for the intermediate-spin Fe(III) trigonal-bipyramidal complex. A quantum dynamical investigation of the photo-deactivation mechanism in the Fe(III) system is presented using the multi-configurational time-dependent Hartree approach based on the vibronic Hamiltonian whose coupling terms are derived from the state-averaged complete active space self-consistent field/complete active space with second-order perturbation theory (CASPT2) calculations and spin–orbit coupling of the scalar-relativistic CASPT2 states. The results of this study show that the presence of a strong (non-relativistic) vibronic coupling between the optically bright intermediate-spin state and other low-lying states of the same spin-multiplicity overpowers the spin–orbit coupling between the intermediate-spin and high-spin states, thereby lowering the chances of spin-crossover while exhibiting ultrafast relaxation among the intermediate-spin states. In a special case, where the population transfer pathway via the non-relativistic vibronic coupling is blocked, the probability of the spin-crossover is found to increase. This suggests that a careful modification of the complex by incorporation of heavier atoms with stronger relativistic effects can enhance the spin-crossover potential of Fe(III) intermediate-spin complexes.