bluuebunny/crossref_metadata_2025 huggingface dataset:
A corpus-based comparison of linguistic markers of stance and genre in the academic writing of novice and advanced engineering learners
Authors: Barbara Siu Wing Yee , Afzaal Muhammad , Aldayel Hessah Saleh
Published: February 2024

Stance-taking in academic writing plays a crucial role in enabling tertiary academic writers to express their positions about their topics and other voices. Based on a corpus linguistic analysis of academic reports by civil and environmental engineering (CEE) undergraduate students and student papers in the Michigan Corpus of Upper-Level Student Papers (MICUSP), this article investigates the use of stance markers in the genres of persuasive and argumentative writing as well as analytical explanatory writing. This study compares the stance markers used by L2 engineering students (Hong Kong University) and native engineering students (U.S. University) to investigate the genre-specific lexical stance patterns used by academic writers. This study found that stance within the CEE reports and MICUSP was expressed through approximative hedges and boosters, code glosses, and adversative and contrast connections, pointing to a specific developmental trajectory as academic writers. Non-native engineering students were found to use a significantly smaller number of approximative, self-mention, and evidential verb hedges. In addition, they tend to use a more significant number of modal hedges compared to native English speakers. The CEE students’ reports also tended to be characterized by the underuse of boosters, contrastive connectors, emphasis, and counter-expectancy markers. However, the study found no significant difference in the use of exemplification markers between the CEE and MICUSP. The findings of this study support the construction of the academic stance as a process of delimiting one’s perspective. This is achieved by deploying selected stance features to account for other scholarly perspectives.
Assessing the factors influencing the intention to use information and communication technology implementation and acceptance in China’s education sector
Authors: Shahzad Muhammad Farrukh , Xu Shuo , Baheer Rimsha
Published: February 2024

Information and communication technology (ICT) has become increasingly important worldwide in education. This study aims to recognize the factors that influence the intention to use information and communication technology (ITUICT) and its acceptance in the education sector in China. A literature review was conducted to ascertain the potential factors such as perceived awareness, information acquisition, trustworthiness, social influence, and regulatory support that could affect the acceptance and ITUICT. For results, a survey was conducted on a sample of 381 university employees in China using a convenience sampling approach. The collected data were analyzed using partial least squares-structural equation modeling (PLS-SEM). The results show that individual factors such as perceived awareness, information acquisition, trustworthiness, social influence, and regulatory support significantly impact the ITUICT. Additionally, trustworthiness positively moderates the relationship among perceived awareness, information acquisition, social influence, regulatory support, and ITUICT. Policymakers and educators can use the findings of this study to enhance the adoption of ICT in China’s education sector. The results of this study suggest that it is important to provide educational sector employees with training and support to increase their use of ICT technology. Furthermore, this paper offers theoretical progression to create a supportive organizational culture and provide the educational sector with the necessary technological resources to facilitate the use of ICT.
Constructing and validating the museum product creativity measurement (MPCM): dimensions for creativity assessment of souvenir products in Chinese urban historical museums
Authors: Cheng Hui , Sun Xu , Xie Jing , Liu Bing-Jian , Xia Liang , Luo Shi-Jian , Tian Xin , Qiu Xiao , Li Wei , Li Yang
Published: February 2024

As museums continue to play an increasingly significant role in the preservation, innovation, and dissemination of cultural heritages, the products sold in their souvenir shops have become a vital carrier of cultural and creative industries. The creativity of these products has drawn intensive attention from various industries. However, the evaluation of museum products’ creativity still lacks objectivity, scientific rigour, and systematisation. This study aims to construct a contextual and comprehensive measurement model to evaluate the creativity of products purchased in souvenir shops affiliated with urban historical museums in China. Based on the literature, ten related hypotheses were introduced, and a conceptual model was illustrated. Six relevant dimensions and 28 corresponding indicators were identified, and then a 7-point Likert-styled questionnaire was developed. An online survey was conducted, which invited 931 participants to take part. Among them, 708 responses are valid (rate 76.05%). The overall reliability of the survey is 0.96 (Cronbach’s α). Then, exploratory factor analysis, confirmatory factor analysis and a structural equation modelling analysis using SPSS and SmartPLS were conducted. The results supported most hypotheses proposed by this study and confirmed the validity of the museum product creativity measurement (MPCM). The validated instrument comprises five dimensions: Affect, Usefulness, Aesthetics, Cultural Values and Novelty, with a total of 21 indicators. Additionally, the findings revealed that Aesthetics mediates Affect, and Cultural Values mediate Usefulness. Moreover, a negative moderating effect of Educational Level on the perception of Cultural Values was detected.
Long-unburnt stands of snow gum (Eucalyptus pauciflora Sieber ex Spreng) are exceedingly rare in the Victorian Alps: implications for their conservation and management
Authors: Morgan John W. , Shackleton Michael , Walker Zac C.
Published: February 2024

The nature of Australia’s high mountains is changing. Recent, repeated landscape-scale fires have burnt much of the subalpine forests dominated by snow gum (Eucalyptus pauciflora). Long-unburnt snow gum forests are important for ecosystem services, have socio-cultural benefits, and conservation values, but they are now exceedingly rare, comprising <1% of snow gum forests in the Victorian Alps. We identify where long-unburnt snow gum stands persist in the Victorian Alps and outline why management intervention is necessary to protect unburnt refuges and, more broadly, to allow mature/adult stands (such as occur on the Baw Baw Plateau) to develop into future old forests.
Solving taxonomic species complexes of Stevia (Eupatorieae, Asteraceae) in southern central Andes: a morphometric and statistical approach
Authors: Rodríguez-Cravero Juan F. , Grossi Mariana A. , Salgado Vanina G. , Gutiérrez Diego G.
Published: February 2024

The South American central Andes have a great richness of Asteraceae, where the genus Stevia (Eupatorieae, Piqueriinae) is also especially diverse. The taxonomy of Stevia species in the southern part of the central Andes pose a challenge because of the unclear delimitation among the species and overlap of morphological characters. Two species complexes were identified for the region comprising north Argentina and southern Bolivia. In this study, our objectives were to employ morphometric analyses to assess the delimitation of taxa within the Stevia alpina Griseb. and Stevia chamaedrys Griseb. complexes. We aimed to identify informative morphological characters and gain insight into the identity of species in each group. To accomplish this, we utilised cluster analysis, principal-component analysis, non-metric multidimensional scaling and univariate analyses to evaluate 37 morphological traits. In total, 200 specimens were examined, covering the entire geographic distribution of each species complex. We found support for the recognition of nine species: Stevia alpina, S. breviaristata Hook. & Arn., S. chamaedrys, S. mandonii Sch.Bip., S. mercedensis Hieron., S. minor Griseb., S. potrerensis Hieron., S. procumbens Hieron. and S. vaga Griseb. A new combination and status is proposed for S. tarijensis Hieron., incorporating it as a variety of S. mandonii, and S. centinelae Cabrera and S. crassicephala Cabrera are merged as synonyms under the name S. alpina. Two neotypes are designated for the names S. mercedensis and S. potrerensis.
Constraining the graviton mass with the NANOGrav 15 year data set
Authors: Wu Yu-Mei , Chen Zu-Cheng , Bi Yan-Chen , Huang Qing-Guo
Published: February 2024

The recently detected stochastic signal by several pulsar timing array collaborations, offers an opportunity to scrutinize the fundamental properties of gravity, including the potential mass of the graviton. In this study, we analyze the North American Nanohertz Observatory for Gravitational Waves 15 year data set to search for a stochastic gravitational wave background with modified Hellings–Downs correlations predicted by massive gravity. While the Bayesian analysis comparing the massive gravity to massless gravity within the effective searchable mass range of

m

g

∈
[
3
×

10

−
25

,
8
×

10

−
24

]

e
V
c

−
2

does not yield an explicit upper bound as all the Bayes factors are smaller than 3, the combined consideration of the minimum frequency inherent in a massive gravity and the observed spectrum leads to an upper limit of

m

g

<
8.2
×

10

−
24

e
V
c

−
2

.
Maximal submergence in dense granular suspensions
Authors: Williams Hollis
Published: February 2024

How far can a person sink downwards in quicksand? Experience would seem to suggest that there is low risk of submerging completely, but it is not easy to demonstrate this because of the complex rheology of granular suspensions. We study several mathematical models for the sinking of a vertical cylinder downwards into quicksand, finding that an approach with a buoyancy equation modified by drag force gives an unphysical answer. We instead argue that our proposed conclusion is supported by considering the dynamics of vibration-induced compactification of liquid-saturated granular suspensions. We compare quicksand with other non-Newtonian fluids, emphasising that in this case the same model does not apply and that the risk of drowning could be much more significant. We finish by suggesting some relevant experiments that can be performed in a classroom setting.
On mathematical problems of two-coefficient inverse problems of ultrasonic tomography
Authors: Goncharsky Alexander V , Romanov Sergey Y , Seryozhnikov Sergey Y
Published: February 2024

This paper proves the theorem of uniqueness for the solution of a coefficient inverse problem for the wave equation in (with two unknown coefficients: speed of sound and absorption. The original nonlinear coefficient inverse problem is reduced to an equivalent system of two uniquely solvable linear integral equations of the first kind with respect to the sound speed and absorption coefficients. Estimates are made, substantiating the multistage method for two unknown coefficients. These estimates show that given sufficiently low frequencies and small inhomogeneities, the residual functional for the nonlinear inverse problem approaches a convex one. This solution method for nonlinear coefficient inverse problems is not linked to the limit approach as frequency tends to zero, but assumes solving the inverse problem using sufficiently low, but not zero, frequencies at the first stage. For small inhomogeneities that are typical, for instance, for medical tasks, carrying out real experiments at such frequencies does not present major difficulties. The capabilities of the method are demonstrated on a model inverse problem with unknown sound speed and absorption coefficients. The method effectively solves the nonlinear problem with parameter values typical for tomographic diagnostics of soft tissues in medicine. A resolution of approximately 2 mm was achieved using an average sounding pulse wavelength of 5 mm.
Bayesian view on the training of invertible residual networks for solving linear inverse problems
*
Authors: Arndt Clemens , Dittmer Sören , Heilenkötter Nick , Iske Meira , Kluth Tobias , Nickel Judith
Published: February 2024

Learning-based methods for inverse problems, adapting to the data’s inherent structure, have become ubiquitous in the last decade. Besides empirical investigations of their often remarkable performance, an increasing number of works address the issue of theoretical guarantees. Recently, Arndt et al (2023 Inverse Problems
39 125018) exploited invertible residual networks (iResNets) to learn provably convergent regularizations given reasonable assumptions. They enforced these guarantees by approximating the linear forward operator with an iResNet. Supervised training on relevant samples introduces data dependency into the approach. An open question in this context is to which extent the data’s inherent structure influences the training outcome, i.e. the learned reconstruction scheme. Here, we address this delicate interplay of training design and data dependency from a Bayesian perspective and shed light on opportunities and limitations. We resolve these limitations by analyzing reconstruction-based training of the inverses of iResNets, where we show that this optimization strategy introduces a level of data-dependency that cannot be achieved by approximation training. We further provide and discuss a series of numerical experiments underpinning and extending the theoretical findings.
A mixture of Si3N4 powder and SiO2 sand as a novel DC arc quenching medium for improvement of the current-limiting performance of a model electric fuse
Authors: Kodama Naoto , Yokomizu Yasunobu , Takenaka Waku
Published: February 2024

A current-limiting and consequent direct current (DC) arc interruption requires an increase in arc resistance

r

a
r
c

for a DC fuse. Flattery silica (SiO2) sand has been used as an arc quenching medium in fuses for decades. However, there are few reports about a novel arc quenching medium which enables more

r

a
r
c

increases compared to flattery SiO2 sand. This paper uniquely selected a novel arc quenching medium based on the following material properties: (1) electrical resistivity and thermal conductivity in the solid phase, (2) the possibility of

r

a
r
c

increasing in the gas phase, (3) the possibility of electrical insulation after re-solidification, and (4) the cost of materials. As a result, we originally selected a powder mixture of silicon-nitride (Si3N4) and flattery SiO2 sand as a promising novel arc quenching medium. Therefore, DC interruption experiments were performed using a Si3N4/flattery SiO2 sand powder mixture under different Si3N4 concentration conditions. As a result of 1000 A DC arc quenching experiments, the utilization of Si3N4 powder with the flattery SiO2 sand successfully increased the arc resistance

r

a
r
c

during the arc quenching process. The increasing Si3N4 concentration exhibited a further increase in

r

a
r
c

during the arc quenching process. As a result of the

r

a
r
c

increase, the arc quenching time was significantly shortened to 30 ms for 30 wt.% Si3N4 conditions from 54 ms for the SiO2 sand conditions. In addition, utilization of Si3N4 powder achieved high insulation resistance over few MΩ after DC arc interruption. The above results clearly indicate that utilization of Si3N4 powder with flattery SiO2 sand can increase the DC interruption performance of the fuse.
Low temperature Raman spectroscopic study of anharmonic and spin-phonon coupled quasi-two dimensional rare earth based francisites
Authors: Manna P , Kanthal S , Das A , Banerjee A , Bandyopadhyay S
Published: February 2024

Mineral francisites Cu3Bi(SeO3)2O2Cl are unique compounds with interesting quasi two-dimensional structure along with fascinating magnetic properties. The magnetic properties can be fine-tuned when non-magnetic Bi is replaced by a suitable rare earth (RE) metal. It is because of the inclusion of additional magnetic sub-centre RE apart from Cu. Temperature dependent Raman spectroscopy measurements in RE based francisites [Cu3RE(SeO3)2O2Cl, shortly RECufr] were performed in the range of 11 K–295 K. Among the three studied RECufr (LaCufr, NdCufr, and DyCufr) compounds, the properties of phonon vibration vary from moderate (in DyCufr) to weak (in LaCufr) spin phonon coupled and the absence of spin phonon coupling (SPC) (i.e. strictly anharmonic in nature) was observed in NdCufr and the reason for this observation has been provided. More specifically, two Raman-active phonons soften below the antiferromagnetic ordering temperature of TN
≈ 39 K in DyCufr compound, indicating the existence of moderate SPC. This trend of phonon vibration is correlated with magnetic properties, particularly field induced metamagnetic transition (MMT). Strong MMT enabled DyCufr develops SPC, while weak MMT enabled NdCufr is unable to develop SPC.
Full-field static and dynamic strain measurement by an inverse conjugate beam method with two-type sensor placement
Authors: Zhang Qingqing , Li Ruixiao , Tian Kang , Gao Qiang
Published: February 2024

This paper presents a novel inverse conjugate beam method (ICBM) to full-field static and dynamic strain measurement using long-gauge fiber Bragg grating (FBG) and vision sensors. By applying reverse analysis of conjugate beam theory, the ICBM establishes a displacement–strain transformation model that effectively explains the correlation between displacement, distributed strain and desired strain. The static and dynamic strain can be reconstructed directly by combining the monitored displacement and strain responses at the displacement monitoring locations. The vision sensor is employed to complement the installed long-gauge strain sensor for monitoring the displacement of the location without a long-gauge sensor. This method helps overcome the difficulty of monitoring the full-bridge strain due to insufficient sensors or inaccessible monitoring positions. At the same time, according to this method, it is necessary to use the displacement from the visual sensor to determine the residual stiffness of each unit as prior information for the ICBM. Both numerical studies and laboratory tests are carried out on a simply supported beam for conceptual verification. The results demonstrate that the proposed ICBM successfully achieves static and dynamic strain response reconstruction at displacement monitoring locations.
Exponential rate of decay of correlations of equilibrium states associated with non-uniformly expanding circle maps
Authors: Garibaldi Eduardo , Inoquio-Renteria Irene
Published: February 2024

In the context of expanding maps of the circle with an indifferent fixed point, understanding the joint behavior of dynamics and pairs of moduli of continuity

(
ω
,
Ω
)

may be a useful element for the development of equilibrium theory. Here we identify a particular feature of modulus Ω (precisely

lim

x
→

0
+

sup

d

Ω
(
d
x
)
/
Ω
(
d
)
=
0

) as a sufficient condition for the system to exhibit exponential decay of correlations with respect to the unique equilibrium state associated with a potential having ω as modulus of continuity. This result is derived from obtaining the spectral gap property for the transfer operator acting on the space of observables with Ω as modulus of continuity, a property that, as is well known, also ensures the Central Limit Theorem. Examples of application of our results include the Manneville–Pomeau family.
Insights into dynamic switching behavior and electric field distribution of depletion-mode GaN HEMT with bonding pad over active layout
Authors: Guo Lijian , Zhou Feng , Xu Weizong , Ren Fangfang , Zhou Dong , Chen Dunjun , Zhang Rong , Zheng Youdou , Lu Hai
Published: February 2024

Bonding pad over active (BPOA) layout, which stacks traditional horizontal structure pad electrodes vertically above the active area, is an area-effective device architecture and packaging-enabled solution for GaN-based high electron mobility transistors (HEMTs). In this work, the dynamic switching and electric field distribution of such layout, as well as associated capacitance–voltage and trapping characteristics, are comprehensively studied on D-mode GaN-on-sapphire HEMT by performing numerical simulations. In terms of different pad electrodes covering the active area, BPOA is composed of various structures such as gate-related and drain-related BPOAs (i.e. G-BPOA and D-BPOA), among which G-BPOA exhibits inferior switching characteristics due to the additional introduction of Miller capacitance that prolongs the device switching, while breakdown voltage of D-BPOA is 400–900 V lower than other BPOA counterparts due to the interplay between D-BPOA and the drain electrode. Furthermore, the effects of trap capture cross section and trap density on switching characteristics are evaluated. These results highlight the differences in electrical characteristics of various structures within the BPOA layout, and provide valuable insights into BPOA device design and performance improvement.
Phenomenological studies on magnetic and mechanical remanence effects in magnetorheological fluids
Authors: Wiener Thomas , Offenzeller Christina , Martetschläger David , Wimmer David , Spirowski Thomas , Jakoby Bernhard
Published: February 2024

Although magnetorheological fluids (MRF) have been used in science and engineering for many decades and several products based on this technology are known, there is still no consistent routine that properly takes into account major effects in the material. The aim of this work is to establish a series of steps, from the preparation of the fluid through the demagnetization routine to the choice of the angular evaluation point, which will allow to achieve stable and reproducible results regarding the material’s response to magnetic fields and mechanical actuation. As a major result of this work, a general demagnetization routine and a method for subsequent reproducible evaluation accounting for the long-term time-dependent behavior of the MRF were identified. Our efforts are aimed at exploring the following targets and questions: how can a stable initial state be ensured? Why is the initial measurement of MRF commonly hardly reproducible? How can reproducible measurements for characterizing the material be obtained? For each of these items, we developed procedures or suggest measures and discuss to what extent they solve the underlying issues and what had to be left for future investigations.
Nanoribbons of large-gap quantum spin Hall insulator: electronic structures and transport properties
Authors: Wu Meimei , Hua Chenqiang , Song Biyu , Zhi Guo-Xiang , Niu Tianchao , Zhou Miao
Published: February 2024

Two-dimensional Bi grown on semiconductor substrate, a large-gap quantum spin Hall insulator characterized by a (p

x
, p

y
)-orbital hexagonal lattice, has been theoretically proposed and experimentally confirmed. Here, by combining tight-binding modeling with first-principles calculations, we investigate the electronic structures and quantum transport properties of Bi nanoribbons (NRs), focusing on the topological edge states for nanoelectronics. We reveal that band gap emerges due to the quantum confinement, and the gaps size depends crucially on the width and edge shape: for zigzag NRs, the gap decreases monotonically with the increase of width; while for armchair NRs, it can be categorized into three subgroups with band-gap hierarchies of

E

g

(
3
p
−
1
)

>

E

g

(
3
p
)

>

E

g

(
3
p
+
1
)

, so that the overall relation is an oscillating dependence dumped by 1/width decay. Quantum transport calculations demonstrate that the conductance is quantized to 2

e

2

/

h

, and an applied gate voltage can efficiently regulate the conductance plateau, originating from the interplay between gate voltage and topological gaps. Furthermore, the quantized conductance remains robust against strong disorder, suggesting the unique advantage of topological states for electronic transport. This work not only provides fundamental insights into the electronic properties of topological insulator nanostructures, but also sheds light on the potential applications of exotic states for quantum devices compatible with semiconductor technology.
Conserved vectors and symmetry solutions of the Landau–Ginzburg–Higgs equation of theoretical physics
Authors: Khalique Chaudry Masood , Lephoko Mduduzi Yolane Thabo
Published: February 2024

This paper is devoted to the investigation of the Landau–Ginzburg–Higgs equation (LGHe), which serves as a mathematical model to understand phenomena such as superconductivity and cyclotron waves. The LGHe finds applications in various scientific fields, including fluid dynamics, plasma physics, biological systems, and electricity-electronics. The study adopts Lie symmetry analysis as the primary framework for exploration. This analysis involves the identification of Lie point symmetries that are admitted by the differential equation. By leveraging these Lie point symmetries, symmetry reductions are performed, leading to the discovery of group invariant solutions. To obtain explicit solutions, several mathematical methods are applied, including Kudryashov’s method, the extended Jacobi elliptic function expansion method, the power series method, and the simplest equation method. These methods yield solutions characterized by exponential, hyperbolic, and elliptic functions. The obtained solutions are visually represented through 3D, 2D, and density plots, which effectively illustrate the nature of the solutions. These plots depict various patterns, such as kink-shaped, singular kink-shaped, bell-shaped, and periodic solutions. Finally, the paper employs the multiplier method and the conservation theorem introduced by Ibragimov to derive conserved vectors. These conserved vectors play a crucial role in the study of physical quantities, such as the conservation of energy and momentum, and contribute to the understanding of the underlying physics of the system.
Nonlocal symmetries, soliton-cnoidal wave solution and soliton molecules to a (2+1)-dimensional modified KdV system
Authors: Wang Jianyong , Ren Bo
Published: February 2024

A (2+1)-dimensional modified KdV (2DmKdV) system is considered from several perspectives. Firstly, residue symmetry, a type of nonlocal symmetry, and the Bäcklund transformation are obtained via the truncated Painlevé expansion method. Subsequently, the residue symmetry is localized to a Lie point symmetry of a prolonged system, from which the finite transformation group is derived. Secondly, the integrability of the 2DmKdV system is examined under the sense of consistent tanh expansion solvability. Simultaneously, explicit soliton-cnoidal wave solutions are provided. Finally, abundant patterns of soliton molecules are presented by imposing the velocity resonance condition on the multiple-soliton solution.
Two-dimensional-lag complex logistic map with complex parameters and its encryption application
Authors: Zhang 张 Fangfang 芳芳 , Wu 武 Jinbo 金波 , Kou 寇 Lei 磊 , Ma 马 Fengying 凤英 , Wu 吴 Liming 黎明 , Zhang 张 Xue 雪
Published: February 2024

With the rapid development of internet technology, security protection of information has become more and more prominent, especially information encryption. Considering the great advantages of chaotic encryption, we propose a 2D-lag complex logistic map with complex parameters (2D-LCLMCP) and corresponding encryption schemes. Firstly, we present the model of the 2D-LCLMCP and analyze its chaotic properties and system stability through fixed points, Lyapunov exponent, bifurcation diagram, phase diagram, etc. Secondly, a block cipher algorithm based on the 2D-LCLMCP is proposed, the plaintext data is preprocessed using a pseudorandom sequence generated by the 2D-LCLMCP. Based on the generalized Feistel cipher structure, a round function F is constructed using dynamic S-box and DNA encoding rules as the core of the block cipher algorithm. The generalized Feistel cipher structure consists of two F functions, four XOR operations, and one permutation operation per round. The symmetric dynamic round keys that change with the plaintext are generated by the 2D-LCLMCP. Finally, experimental simulation and performance analysis tests are conducted. The results show that the block cipher algorithm has low complexit, good diffusion and a large key space. When the block length is 64 bits, only six rounds of encryption are required to provide sufficient security and robustness against cryptographic attacks.
Consistency between domain wall oscillation modes and spin wave modes in nanostrips
Authors: Dong 董 Xinwei 新伟 , Wu 吴 Zhenjiang 振江
Published: February 2024

Investigations on domain wall (DW) and spin wave (SW) modes in a series of nanostrips with different widths and thicknesses have been carried out using micromagnetic simulation. The simulation results show that the frequencies of SW modes and the corresponding DW modes are consistent with each other if they have the same node number along the width direction. This consistency is more pronounced in wide and thin nanostrips, favoring the DW motion driven by SWs. Further analysis of the moving behavior of a DW driven by SWs is also carried out. The average DW speed can reach a larger value of ∼140 m/s under two different SW sources. We argue that this study is very meaningful for the potential application of DW motion driven by SWs.
Atomistic understanding of capacity loss in LiNiO2 for high-nickel Li–ion batteries: First-principles study
Authors: Peng 彭 Shuai 率 , Chen 陈 Li-Juan 丽娟 , He 何 Chang-Chun 长春 , Yang 杨 Xiao-Bao 小宝
Published: February 2024

Combining the first-principles calculations and structural enumeration with recognition, the delithiation process of LiNiO2 is investigated, where various supercell shapes are considered in order to obtain the formation energy of Li
x
NiO2. Meanwhile, the voltage profile is simulated and the ordered phases of lithium vacancies corresponding to concentrations of 1/4, 2/5, 3/7, 1/2, 2/3, 3/4, 5/6, and 6/7 are predicted. To understand the capacity decay in the experiment during the charge/discharge cycles, deoxygenation and Li/Ni antisite defects are calculated, revealing that the chains of oxygen vacancies will be energetically preferrable. It can be inferred that in the absence of oxygen atom in high delithiate state, the diffusion of Ni atoms is facilitated and the formation of Li/Ni antisite is induced.
Non-Gaussian quantum states generated via quantum catalysis and their statistical properties
Authors: Zhang 张 Xiao-Yan 晓燕 , Yang 杨 Chun-Yan 春燕 , Wang 王 Ji-Suo 继锁 , Meng 孟 Xiang-Guo 祥国
Published: February 2024

A new kind of non-Gaussian quantum catalyzed state is proposed via multiphoton measurements and two-mode squeezing as an input of thermal state. The characteristics of the generated multiphoton catalysis output state depends on the thermal parameter, catalyzed photon number and squeezing parameter. We then analyze the nonclassical properties by examining the photon number distribution, photocount distribution and partial negativity of the Wigner function. Our findings indicate that nonclassicality can be achieved through the implementation of multiphoton catalysis operations and modulated by the thermal parameter, catalyzed photon number and squeezing parameter.
Robust T
c in element molybdenum up to 160 GPa
Authors: Wu 吴 Xinyue 新月 , Guo 郭 Shumin 淑敏 , Guo 郭 Jianning 鉴宁 , Chen 陈 Su 诉 , Wang 王 Yulong 煜龙 , Zhang 张 Kexin 可欣 , Zhu 朱 Chengcheng 程程 , Liu 刘 Chenchen 晨晨 , Huang 黄 Xiaoli 晓丽 , Duan 段 Defang 德芳 , Cui 崔 Tian 田
Published: February 2024

Element superconductors with the single atoms provide clean and fundamental platforms for studying superconductivity. Although elements with d electrons are usually not favored by conventional BCS, the record superconducting critical temperature (T
c) in element scandium (Sc) has further ignited the intensive attention on transition metals. The element molybdenum (Mo) with a half-full d-orbital is studied in our work, which fills the gap in the study of Mo under high pressure and investigates the pressure dependence of superconductivity. In this work, we exhibit a robust superconductivity of Mo in the pressure range of 5 GPa to 160 GPa via high-pressure electrical transport measurements, the T
c varies at a rate of 0.013 K/GPa to 8.56 K at 160 GPa. Moreover, the superconductivity is evidenced by the T
c shifting to lower temperature under applied magnetic fields, and the upper critical magnetic fields are extrapolated by the WHH equation and GL equation; the results indicate that the maximum upper critical magnetic field is estimated to be 8.24 T at 137 GPa. We further investigate the superconducting mechanism of Mo, the theoretical calculations indicate that the superconductivity can be attributed to the strong coupling between the electrons from the partially filled d band and the phonons from the frequency zone of 200–400 cm−1.
Coexistence of Dirac and Weyl points in non-centrosymmetric semimetal NbIrTe4
Authors: Liu 刘 Qingxin 清馨 , Fu 付 Yang 阳 , Ding 丁 Pengfei 鹏飞 , Ma 马 Huan 欢 , Guo 郭 Pengjie 朋杰 , Lei 雷 Hechang 和畅 , Wang 王 Shancai 善才
Published: February 2024

Using angle-resolved photoemission spectroscopy and density functional theory calculations methods, we investigate the electronic structures and topological properties of ternary tellurides NbIrTe4, a candidate for type-II Weyl semimetal. We demonstrate the presence of several Fermi arcs connecting their corresponding Weyl points on both termination surfaces of the topological material. Our analysis reveals the existence of Dirac points, in addition to Weyl points, giving both theoretical and experimental evidences of the coexistence of Dirac and Weyl points in a single material. These findings not only confirm NbIrTe4 as a unique topological semimetal but also open avenues for exploring novel electronic devices based on its coexisting Dirac and Weyl fermions.
B meson rare decays in the TNMSSM*
Authors: Chen 陈 Hai-Xiang 海翔 , Cui 崔 Sheng-Kai 生恺 , Zhu 朱 Ning-Yu 宁宇 , Zhang 张 Zhao-Yang 兆阳 , Hu 胡 Huai-Cong 怀聪
Published: February 2024

We investigate the two loop electroweak corrections to B meson rare decays

and

in the minimal supersymmetry standard model (MSSM) extension with two triplets and one singlet (TNMSSM). The new particle contents and interactions in the TNMSSM can affect the theoretical predictions of the branching ratios

and

, and the corrections from two loop diagrams to the process

can reach around

. Considering the latest experimental measurements, the numerical results of

and

in the TNMSSM are presented and analyzed. The findings indicate that the results in the TNMSSM can fit the updated experimental data well, and the new parameters

, clearly affect the theoretical predictions of

and

.
Thermodynamic properties and phase diagram of quark matter within non-extensive Polyakov chiral SU (3) quark mean field model
Authors: Singh Dhananjay , Kumar Arvind
Published: February 2024

In the present study, we applied Tsallis non-extensive statistics to investigate the thermodynamic properties and phase diagram of quark matter in the Polyakov chiral SU(3) quark mean field model. Within this model, the properties of the quark matter were modified through the scalar fields

, vector fields

, ϕ, and Polyakov fields Φ and

at finite temperature and chemical potential. Non-extensive effects were introduced through a dimensionless parameter q, and the results were compared to those of the extensive case (

). In the non-extensive case, the exponential in the Fermi-Dirac (FD) function was modified to a q-exponential form. The influence of the q parameter on the thermodynamic properties, pressure, energy, and entropy density, as well as trace anomaly, was investigated. The speed of sound and specific heat with non-extensive effects were also studied. Furthermore, the effect of non-extensivity on the deconfinement phase transition as well as the chiral phase transition of

and s quarks was explored. We found that the critical end point (CEP), which defines the point in the

phase diagram where the order of the phase transition changes, shifts to a lower value of temperature,

, and a higher value of chemical potential,

, as the non-extensivity is increased, that is,

1.
Molecular components in J/ψ and ρ-π puzzle*
Authors: Guo 郭 Xing-Dao 星导 , Chen 陈 Dian-Yong 殿勇 , Li 李 Xue-Qian 学潜 , Yuan 苑 Zhong-Yuan 仲元 , Sang 桑 Shijing 士晶
Published: February 2024

Motivated by the large branching fractions of

and the light exotic candidates, we found that there may exist molecular states composed of

and

, which correspond to

and

observed a few decades ago. The branching fractions of

and

to various

and

channels were estimated in the molecular scenario. In addition, the large branching fractions of

indicate sizable molecular components in the

state. Thus, we consider

as the superposition of the

,

, and

molecular states. These molecular components have a significant impact on the light hadron decays of

, which may elucidate the long standing

puzzle.
Research on optical fiber current transducer using nv center in diamond
Authors: Song Qiang , Yang Lu , Zhang Dingqu , Dang Sanlei , Xing Likun , Liu Jing
Published: February 2024

Diamond nitrogen-vacancy (NV) center has been widely employed in experimental magnetic field measurement using continuous wave optical detection magnetic resonance (ODMR), which makes it possible for current sensing. An optical fiber current transducer prototype using an NV center is built for electric power application. The DC measurement with an error of less than 4% within 500 A is realized, in which the error of 50 A to 450 A is better than 2%, and the low-frequency AC measurement is preliminarily realized. In this essay, the accuracy of low current measurement is primarily affected by system noise, while the accuracy of heavy current is mainly affected by the width of the ODMR resonance peak. Optimizing the optical path as well as sensing structure meanwhile updating the demodulation algorithm of the measured data is the following work to improve the measurement accuracy.
A coordination control strategy for parallel-connected boost converters in dc microgrid
Authors: Lin Jinwei , Wang Dongsheng , Zhang Le , Ji Tao , Wang Hui
Published: February 2024

Due to the constant power loads (CPLs), the system damping of the DC microgrid is reduced, which will lead to the collapse of bus voltage. In addition, the errors of current sharing amplify due to different line impedances. To address these issues, a hybrid coordination control strategy is proposed for parallel-connected boost converters, which realizes stable control and maintains the accuracy of the current distribution. Firstly, a passivity-based control (PBC) with a proportional-integral (PI) regulator is developed. The virtual damping-based PBC enhances the system damping and the PI regulator eliminates errors. On this basis, a secondary voltage control (SVC) featuring simplicity and weak dependence on communication is introduced to remove the errors of current distribution. Finally, the hybrid coordination control strategy is verified by RT-LAB-based hardware in the loop (HIL) experiment.
Analysis of Microphone Coupling and Zero-Point Calibration Model for Non-Resonant Photoacoustic Spectroscopy
Authors: Sun Liqiang , Cui Fangxiao , Wang Anjing
Published: February 2024

Dissolved Gas Analysis (DGA) of transformer insulation oil is an effective method for monitoring transformer operating conditions and diagnosing faults. Photoacoustic spectroscopy (PAS) is widely employed for online dissolved gas analysis in transformer oil. The positioning of the pressure equalization hole within the sound field significantly impacts the microphone’s sensitivity when coupled with the photoacoustic cell in non-resonant photoacoustic spectroscopy. The static temperature and humidity characteristics inside the photoacoustic cell also have a notable influence on the microphone’s output signal. Consequently, an analysis is performed to explore the relationship between the sensitivity of the photoacoustic spectrometer and temperature/humidity, leading to the optimization of the system configuration based on the microphone parameters. Moreover, the photoacoustic zero-point signal is influenced by the temperature and humidity levels within the photoacoustic cell. To address this problem, air mixtures at different humilities are measured, resulting in the establishment of a zero-point model for the background signal in Photoacoustic Spectroscopy (PAS). Subsequently, the experimental detection of acetylene under various humidity mixtures is conducted, successfully extracting effective signals for the measurement of 5 ppm acetylene gas. These results serve as evidence showcasing the efficacy of both the proposed structural optimization and zero-point model put forth in this study.
Intelligent residual film recovery machine monitoring and control system
Authors: Wang Zifan , Jian Jianming , Tang Xiuying , Niu Changhe , Wang Meng , Wu Kai , Tian Ziyang
Published: February 2024

Domestic residue recovery machines in China still follow the traditional towed mechanical model, lacking automation and intelligent features. Under the key R&D project of Xinjiang Autonomous Region, our team has developed integrated intelligent agricultural machinery for cotton straw crushing and residue recovery. This research covers the monitoring and control system, including PLC control and communication, working parameter monitoring and adjustment, algorithmic control of electro-hydraulic actuators, and human-machine interface display. Compared to traditional models, this machine replaces the conventional chain-driven mechanical structure and diesel tractor traction power with a fully hydraulic integrated suspension drive and power system. Sensors, PLC, and a touch screen are utilized for real-time monitoring and display of parameters. Hardware components like electromagnetic switch valves, electro-hydraulic proportional valves, hydraulic cylinders, and software elements such as PLC programs and intelligent control algorithms are employed for electro-hydraulic switching and proportional control of certain working parameters and mechanisms. All parameter information is consolidated in the PLC host and expansion modules and displayed and controlled on the human-machine interface. The system was installed on the first-generation machine for indoor testing, revealing that the monitoring and control system used on the first-generation machine achieves parameter detection and adjustment of the actuating mechanisms. It incorporates more advanced functions compared to traditional residue recovery machines. However, there is still ample room for improvement in the overall intelligence of the machine. The control system’s structure requires adjustment, and certain functionalities of the overall mechanical structure and working components need optimization or upgrading. Detailed enhancements to the entire system will be made in the next-generation machine.
Study on electromagnetic dosimetry of the power cable in electric vehicle
Authors: Dong Xuwei , Gao Yunshan
Published: February 2024

To calculate the induced fields in the human body of the driver in an electric vehicle, the power cables of the electric vehicle are taken as the electromagnetic exposure source. The finite elements method is used to construct the electromagnetic environment model, which consists of the vehicle body, the power cables, and the driver body. The maximal values of the magnetic flux density inside the driver’s trunk and head are 4.63 μT and 0.12 μT, respectively. The maximal induced electric field intensity values are 670 mV/m and 99.7 mV/m, respectively. All values are below the safety limits of the ICNIRP. The results show that the electromagnetic environment induced by the power cables is safe for the driver. The study could provide a reference for improving electromagnetic exposure standards for electric vehicles.
Development of new pocket distribution network inspection equipment
Authors: Lin Lin , Su Weiwei , Wang Qinyang , Ge Qin
Published: February 2024

This paper aims to explore a new intelligent inspection mode of pocket distribution network equipment, which realizes rapid and comprehensive inspection and inspection by using terminal +N intelligent sensors and partial discharge detection and infrared temperature measurement technology as the core. First, this paper introduces the background and motivation of the new mode, and emphasizes the limitations of the existing traditional inspection methods and the problems that need to be improved. Then, the design and manufacture of pocket devices are described in detail, including key aspects such as sensor integration, portability and user-friendliness. Finally, the paper summarizes the research results and emphasizes the potential benefits and future research directions of this new intelligent inspection model.
Research and application of relay protection setting calculation for SFC system of pumped storage power station
Authors: Shi Fangfang , Yang Chao , Zhang Zehui , Zhang Zhaohui , Xu Kezheng
Published: February 2024

Pumped storage is a key way to meet the regulatory needs of the power system. Currently, SFC starting has become the main starting method for large pumped storage power plants. This article introduces the typical structure and operation principle of SFC in pumped storage power plants. Based on existing guidelines, the relay protection configuration and setting principles of the SFC system in pumped storage power plants are elaborated. Starting from engineering practice, a relay protection setting calculation scheme for SFC input and output transformers is proposed and put into operation on site, ensuring the reliable and stable operation of the SFC system in pumped storage power plants.
Grasping characteristics of SMA bionic flexible dexterous hand
Authors: Song Hailong , Ren Tingting , Ni Yingqian , Wen Shanlin , Wang Cai , Zhang Wenbin
Published: February 2024

In order to achieve the mechanical performance of grasping objects with SMA bionic flexible hands, a tendon finite element modeling method is proposed in this article to meet the mechanical requirements of the tendon being subjected to only axial forces and not radial forces. By using finite element dynamic simulation and experimental testing methods, the mechanical characteristics of the SMA bionic hands during the grasping process are analyzed and validated. A finite element dynamic simulation model of the SMA bionic hand grasping process is established to study the overall stress characteristics and contact forces of each phalanx, revealing the grasping characteristics of the bionic hand under SMA driving conditions. By creating a physical prototype of the SMA bionic hand, grasping of different objects is achieved. The results show that the stress in the grasping state of the bionic hand does not exceed 21 MPa, the sum of contact forces is 22 N, the theoretical grasping force is 13 N, and the prototype can grasp objects within a diameter range of 70 mm.