bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence by the hub vortex on the instability of the tip vortices shed by propellers with and without winglets
Authors: Posa A. , Broglia R.
Published: November 2022

Large-eddy simulations on a cylindrical grid consisting of 5 × 109 points are reported on both conventional and winglets propellers with and without a downstream shaft. Comparisons are focused on the influence by the hub vortex on the process of instability of the tip vortices. They demonstrate that in straight ahead conditions, this influence is actually quite limited for both propellers. The presence of the hub vortex at the wake core results in only a slight upstream shift of the instability of the tip vortices. Meanwhile, the development of the instability of the hub vortex is always delayed, compared to that of the tip vortices, and the former keeps coherent further downstream of their breakup. The results of this study highlight that the hub vortex is not a major source of instability of the tip vortices. Therefore, simplified configurations with no hub vortex, often adopted in the literature, can also provide a good approximation of the process of instability of the tip vortices shed by actual propellers. In contrast, the instability of the tip vortices could be the trigger of that of the hub vortex, whose development is slower. Therefore, experimental and computational studies aimed at analyzing the dynamics of the hub vortex should be designed accordingly, extending to further downstream distances.
Spectroscopic signatures of states in the continuum characterized by a joint experimental and theoretical study of pyrrole
Authors: Mukherjee Madhubani , Ragesh Kumar T. P. , Ranković Miloš , Nag Pamir , Fedor Juraj , Krylov Anna I.
Published: November 2022

We report a combined experimental and theoretical investigation of electron–molecule interactions using pyrrole as a model system. Experimental two-dimensional electron energy loss spectra (EELS) encode information about the vibrational states of the molecule as well as the position and structure of electronic resonances. The calculations using complex-valued extensions of equation-of-motion coupled-cluster theory (based on non-Hermitian quantum mechanics) facilitate the assignment of all major EELS features. We confirm the two previously described π resonances at about 2.5 and 3.5 eV (the calculations place these two states at 2.92 and 3.53 eV vertically and 2.63 and 3.27 eV adiabatically). The calculations also predict a low-lying resonance at 0.46 eV, which has a mixed character—of a dipole-bound state and σ* type. This resonance becomes stabilized at one quanta of the NH excitation, giving rise to the sharp feature at 0.9 eV in the corresponding EELS. Calculations of Franck–Condon factors explain the observed variations in the vibrational excitation patterns. The ability of theory to describe EELS provides a concrete illustration of the utility of non-Hermitian quantum chemistry, which extends such important concepts as potential energy surfaces and molecular orbitals to states embedded in the continuum.
An efficient analytical model and experiments of 3D electromagnetic force of permanent magnet electrodynamic suspension system
Authors: Wu Chuan , Li Guanchun , Wang Dong , Xu Jie
Published: November 2022

Electrodynamic suspension (EDS) with a linear permanent magnet Halbach array, which can be used in ultrahigh-speed maglev systems, has gained increasing attention in recent years. However, inefficient calculation methods of electromagnetic forces restrict the stability research of EDS systems. Hence, an efficient 3D analytical model of the electromagnetic force is established in the paper based on an improved analytical model of the source magnetic field excited by the Halbach array, and then the application conditions of the model are studied. Finally, the analytical results are compared with the experimental results, which are provided by the experiments carried out on a high-speed rotating experiment platform with a flywheel. The results show that the proposed model can shorten the computation time of electromagnetic force to less than 10 ms and the relative errors of analytical results are around 5% under the conditions ①wp/τ≥2.5, wd/wp≥1.5 or ②wp/τ≥4, wd/wp≥1 (τ is the pole pitch of the Halbach array, wp is the width of the permanent magnet, wd is the width of the conducting plate). The analytical model meets the engineering requirements and can provide a reference for further stability research and experiments on EDS systems.
Response to “Comment on ‘Even-order harmonic generation from nonlinear Thomson backscatter in a tightly focused Gaussian laser pulse’” [Phys. Plasmas 29, 114703 (2022)]
Authors: Hong Xue-Ren , Shi Ke , Li Ya-Nan , Wei Dou , Tang Rong-An , Sun Jian-An , Duan Wen-Shan
Published: November 2022

In a recent Comment, Chang et al. [Phys. Plasmas 29, 114703 (2022)] have studied the electron dynamics for an electron accelerating in a tightly focused Gaussian laser pulse with the higher order correction terms, and it is found that the initial position of the electron is the reason why the electron is pushed to the −z axis at the end. In this Reply, the electron dynamics and its nonlinear Thomson backscattering in a tightly focused Gaussian laser pulse with the higher order correction terms are presented, and it is found that the result is consistent with the lowest order approximation case in our paper [Hong et al., Phys. Plasmas 29, 043102 (2022)]. Meanwhile, it is also found that when the longitudinal deceleration effect of the ponderomotive force on the electron introduced by the falling part of the tightly focused laser pulse is greater than the longitudinal acceleration effect of the rising part, the electron that is initially stationary will be slightly pushed to the −z axis at the end, which can well explain the “return” phenomenon of the electron in the longitudinal direction both in our paper and in the Comment.
Voltage-sensor movements in the Eag Kv channel under an applied electric field
Authors: Mandala Venkata Shiva , MacKinnon Roderick
Published: November 2022

Voltage-dependent ion channels regulate the opening of their pores by sensing the membrane voltage. This process underlies the propagation of action potentials and other forms of electrical activity in cells. The voltage dependence of these channels is governed by the transmembrane displacement of the positive charged S4 helix within their voltage-sensor domains. We use cryo-electron microscopy to visualize this movement in the mammalian Eag voltage-dependent potassium channel in lipid membrane vesicles with a voltage difference across the membrane. Multiple structural configurations show that the applied electric field displaces S4 toward the cytoplasm by two helical turns, resulting in an extended interfacial helix near the inner membrane leaflet. The position of S4 in this down conformation is sterically incompatible with an open pore, thus explaining how movement of the voltage sensor at hyperpolarizing membrane voltages locks the pore shut in this kind of voltage-dependent K
+
(K
v
) channel. The structures solved in lipid bilayer vesicles detail the intricate interplay between K
v
channels and membranes, from showing how arginines are stabilized deep within the membrane and near phospholipid headgroups, to demonstrating how the channel reshapes the inner leaflet of the membrane itself.
The role of word frequency in the L2 acquisition of variable patterns
Authors: van de Weijer Jeroen , Sloos Marjoleine , Wei Weiyun
Published: November 2022

Second language acquisition often involves the acquisition of stable patterns in a target language. Here we
investigate how the acquisition of a variable pronunciation pattern, viz. the pronunciation of the semisuffix -man
in professional names in English (e.g. policeman, businessman) is related to the lexical
frequency of the words concerned. The pronunciation of this suffix varies between a full vowel and a reduced one in a lexically
unpredictable manner (i.e. some words with -man tend to have schwa, others a full vowel, and still others vary
between the two). To test how the pronunciation of such words is acquired in a second language, we carried out a picture naming
experiment in which Chinese subjects were asked to pronounce them. The results show that the pronunciation of this semisuffix is
especially related to the educational status of subjects (major vs. non-major).
Metaphorical conceptualizations of cancer treatment in English and Chinese languages
Authors: Chow Mei-Yung Vanliza , Littlemore Jeannette
Published: November 2022

Cross-cultural variation in the metaphors that are employed by healthcare researchers and professionals when discussing cancer care is a potential impediment to the sharing of expertise. By identifying patterns in the metaphorical language used in these contexts, we can reveal differences in how healthcare practitioners understand cancer and its treatments, thus enabling more effective intercultural communication in the field of oncology. To this end, the use of metaphor in collocations of the word ‘treatment’ in nursing journals published in British English, mainland Chinese, and Taiwanese Chinese is compared. Our analysis reveals differences regarding the agency given to the cancer, its treatment, and the patient; the interrelatedness of different bodily functions and organs; and the emphasis that is placed on the course of treatment as a whole as opposed to its individual stages.
“Fish die of number, animals of footprints, but humans by mouths [words]!”
Authors: Haokip Pauthang
Published: November 2022

This paper discusses the cultural knowledge of Thadou-Kuki which constitutes one of the least explored genres of language use, with the hope that it will remain a source of information for future generation speakers and scholars. The paper provides examples of the vast pool of knowledge that lies underneath the traditional culture. It discusses two types of cultural knowledge in Thadou-Kuki, namely, material and oral culture transmitted from one generation of speakers to the other; these have not received the kind of attention that they deserve. The study shows how both material and oral culture are fast disappearing due to onslaughts from different quarters: the shift from traditional to a more sedentary lifestyle, the shift from traditional religion to Christianity, and finally the shift from traditional modes of entertainment to modern forms of entertainment. Many of the phenomena discussed in the paper apply to many of the other languages spoken in the hills of Northeast India, which are faced with similar threats.
Kwame Nkrumah’s construction of ‘the African people’ via the Unite or Perish myth
Authors: Nartey Mark
Published: November 2022

Employing Wodak’s discourse-historical approach, this paper examines how Ghana’s independence leader – Kwame
Nkrumah – in his creation of the Unite or Perish myth constructed ‘the African people’ in a manner in sync with populist
performance. It argues that Nkrumah’s discourse, in its focus on the formation of a Union Government of Africa as the only means
of Africa’s peace, progress, security and survival in the post-independence era, can be characterized as a form of populist
rhetoric that presupposes an antagonistic relationship between two homogeneous social groups. To this end, the paper analyzes
three discursive strategies utilized by Nkrumah in promoting anti-establishment sentiments while celebrating or valorizing ‘the
ordinary people’: nomination and predication of social actors and actions, the construction of a man of the people image and the
exploitation of familiarity and historical memory. It concludes with a discussion on the implications of the study for political
discourse analysis in terms of the interrelationship between political myth and populist performance.
Mitigating requesting acts by deaf Jordanian adults
Authors: Nahar Al-Ali Mohammed , Shatat Salsabeel M.
Published: November 2022

The purpose of this study is to investigate the linguistic mitigating devices that deaf Jordanian adults use when making requests. To this end, a sample of 52 people (of whom 26 were hearing and 26 were deaf) was collected through a Discourse Completion Task (DCT). It was found that the two groups of participants showed variations in the way they structured their request acts and spelled them out. This was evident in the deaf group’s obvious underuse of certain request mitigation strategies and the lexico-grammatical items mapping them; in the absence of some strategies (i.e., sweetener, promise of reward, hint, and threat); and in the underassessment of social distance, relative power, and degree of imposition. This inappropriate use of requesting acts by deaf participants is attributed to their inadequate linguistic, pragma-linguistic and socio-pragmatic competence. The study concludes with some suggestions how to improve the Jordanian educational system for the deaf.
The role of prior and actual situational context in conversational routines produced by Chinese learners of English
Authors: Wang Yuqi
Published: November 2022

This study aims to investigate the effects of English proficiency (EP) and study-abroad (SA) experience on routine production among 143 Chinese university English learners. The interplay of learners’ mastery of prior context (PC) and actual situational context (ASC) knowledge reflected their productive competence of routines (PCR). Participants were divided into three groups based on their EP levels and length of SA experience: high EP without SA, low EP without SA, and high EP with SA. A pilot study with 41 American native speakers was conducted to determine the target response set as the baseline. A seven-item computer-animated production task was used to elicit routines that revealed learners’ mastery of ASC and PC knowledge. The findings revealed that EP was only necessary for learners’ PC knowledge and PCR. SA experience, alongside SA and EP interaction, had a significant impact on both sides of ASC and PC knowledge, as well as learners’ overall PCR.
Situated co-operative creativity
Authors: Due Brian L.
Published: November 2022

A highly important societal aspect of language use are pragmatic creative acts and interactions. The ability to,
through multimodal interaction, create something new, is primordial for human sociality. In this paper, I propose a theoretical
model that enables detailed analysis of situated co-operative creative actions as these naturally emerge in interactional
situations. First, I develop the theoretical model by extrapolating from Charles Goodwin’s theory of co-operative action. I then
illustrate the model through detailed analysis of a single case where participants interact in a video-mediated robotic context.
The model is situated within ethnomethodological multimodal conversation analysis and based on video ethnographic data. This
research contributes to the field of creativity and human pragmatic action by providing an applicable model for Situated
Co-Operative Creativity, the SCOC model, which can be used for detailed analysis of everyday creativity.
Demographic Characteristics of Convicted Child Sexual Abusers in South of Sweden, Between 2013 and 2018: A Pilot Study
Authors: Stiernströmer Emelie , Väfors Fritz Marie , Mellgren Caroline , Khoshnood Ardavan
Published: November 2022

This study evaluates variables concerning demographic characteristics for all adult male offenders convicted of Child Sexual Abuse (CSA) aged 0–17 in Malmö, Sweden between 2013 and 2018. All convictions (n = 18) based on court documents from the District Court, the Court of Appeals and information from the Swedish Tax Agency were reviewed. A total of 30 victims were identified. Frequency analyses show that the most common features were that of a single offender, averaging 25 years old, with a non-Swedish background and a high school degree. The predominately extrafamilial CSA (i.e. committed by an acquaintance to the family) occurred in a private setting and consisted of penetrative acts. Girls averaging 13 years old were abused multiple times, under fear and pressure. Although assumptions based on these results are preliminary, they provide a clearer image of the typical circumstances under which CSA occurred within this time frame and geographical location. This study is a first attempt to construct an overview of demographic characteristics of CSA. As more data are gathered from this region, more sophisticated analyses can be conducted, providing stronger generalizations. Information of this kind may be important for research, classification of offender profiling and in case linking.
Exploring the small mass limit of stationary black holes in theories with Gauss–Bonnet terms
Authors: Fernandes Pedro G S , Mulryne David J , Delgado Jorge F M
Published: November 2022

In this work we examine the small mass limit of black holes (BHs), with and without spin, in theories where a scalar field is non-minimally coupled to a Gauss–Bonnet (GB) term. First, we provide an analytical example for a theory where a static closed-form solution with a small mass limit is known, and later use analytical and numerical techniques to explore this limit in standard scalar-GB theories with dilatonic, linear and quadratic-exponential couplings. In most cases studied here, we find an inner singularity that overlaps with the event horizon of the static BH as the small mass limit is reached. Moreover, since solutions in this limit possess a non-vanishing Hawking temperature, a naked singularity is expected to be reached through evaporation, raising questions concerning the consistency of these theories altogether. On the other hand, we provide for the first time in this context an example of a coupling where the small mass limit is never reached, thus preferred from the point of view of cosmic censorship. Finally, we consider BHs with spin and numerically investigate how this changes the picture, using these to place the tightest upper bounds to date on the coupling constant for the dilatonic and linear theories, with

α
‾

<
1

km.
A Birman–Schwinger principle in galactic dynamics: ESI, Vienna, 07–11 February 2022
Authors: Kunze Markus
Published: November 2022

These are the (somewhat extended) lecture notes for four lectures delivered at the spring school during the thematic programme ‘Mathematical Perspectives of Gravitation beyond the Vacuum Regime’ at ESI Vienna in February 2022.
Universal signature of quantum entanglement across cosmological distances
Authors: Brahma Suddhasattwa , Berera Arjun , Calderón-Figueroa Jaime
Published: November 2022

Although the paradigm of inflation has been extensively studied to demonstrate how macroscopic inhomogeneities in our Universe originate from quantum fluctuations, most of the established literature ignores the crucial role thatentanglementbetween the modes of the fluctuating field plays in its observable predictions. In this paper, we import techniques from quantum information theory to reveal hitherto undiscovered predictions for inflation which, in turn, signals how quantum entanglement across cosmological scales can affect large scale structure. Our key insight is that observable long-wavelength modes must be part of anopen quantum system, so that the quantum fluctuations can decohere in the presence of an environment of short-wavelength modes. By assuming the simplest model of single-field inflation, and considering the leading order interaction term from the gravitational action, we derive auniversal lower boundon the observable effect of such inescapable entanglement. Although this signal is too weak for direct detection in the foreseeable future, we discuss the importance of its theoretical implications.
Radial recombination for rigid rotational alignment of images and volumes
Authors: Rangan Aaditya V
Published: November 2022

A common task in single particle electron cryomicroscopy (cryo-EM) is the rigid alignment of images and/or volumes. In the context of images, a rigid alignment involves estimating the inner product between one image of N × N pixels and another image that has been translated by some displacement and rotated by some angle γ. In many situations the number of rotations γ considered is large (e.g.

), while the number of translations considered is much smaller (e.g.

). In these scenarios a naive algorithm requires

operations to calculate the array of inner products for each image pair. This computation can be accelerated by using a Fourier–Bessel basis and the fast Fourier transform, requiring only

operations per image pair. We propose a simple data driven compression algorithm to further accelerate this computation, which we refer to as the ‘radial SVD’. Our approach involves linearly recombining the different rings of the original images (expressed in polar coordinates), taking advantage of the singular value decomposition (SVD) to both compress the images and optimize a certain measure of angular discriminability. When aligning multiple images to multiple targets, the complexity of our approach is

O
(
N
(
log
(
N
)
+
H
)
)

per image pair, where H is the rank of the SVD used in the compression above. A very similar strategy can be used to accelerate volume alignment, using a spherical harmonic based compression, which we will refer to as a ‘degree SVD’. The advantage gained by these approaches depends on the ratio between H and N; the smaller H is the better. In many applications H can be quite a bit smaller than N while still maintaining accuracy. We present numerical results in a cryo-EM application demonstrating that the radial and degree SVD can help save a factor of 5–10 or more for both image and volume alignment.
Towards precise and accurate calculations of neutrinoless double-beta decay
Authors: Cirigliano V , Davoudi Z , Engel J , Furnstahl R J , Hagen G , Heinz U , Hergert H , Horoi M , Johnson C W , Lovato A , Mereghetti E , Nazarewicz W , Nicholson A , Papenbrock T , Pastore S , Plumlee M , Phillips D R , Shanahan P E , Stroberg S R , Viens F , Walker-Loud A , Wendt K A , Wild S M
Published: November 2022

We present the results of a National Science Foundation Project Scoping Workshop, the purpose of which was to assess the current status of calculations for the nuclear matrix elements governing neutrinoless double-beta decay and determine if more work on them is required. After reviewing important recent progress in the application of effective field theory, lattice quantum chromodynamics, and ab initio nuclear-structure theory to double-beta decay, we discuss the state of the art in nuclear-physics uncertainty quantification and then construct a roadmap for work in all these areas to fully complement the increasingly sensitive experiments in operation and under development. The roadmap includes specific projects in theoretical and computational physics as well as the use of Bayesian methods to quantify both intra- and inter-model uncertainties. The goal of this ambitious program is a set of accurate and precise matrix elements, in all nuclei of interest to experimentalists, delivered together with carefully assessed uncertainties. Such calculations will allow crisp conclusions from the observation or non-observation of neutrinoless double-beta decay, no matter what new physics is at play.
Successive phase transitions of the spin–orbit-coupled metal Cd2Re2O7 probed by high-resolution synchrotron x-ray diffraction
Authors: Hirai Daigorou , Fukui Atsuhito , Sagayama Hajime , Hasegawa Takumi , Hiroi Zenji
Published: November 2022

The 5d pyrochlore oxide superconductor Cd2Re2O7 (CRO) has attracted significant interest as a spin–orbit-coupled metal (SOCM) that spontaneously undergoes a phase transition to an odd-parity multipole phase by breaking the spatial inversion symmetry due to the Fermi liquid instability caused by strong spin–orbit coupling. Despite the significance of structural information during the transition, previous experimental results regarding lattice deformation have been elusive. We have conducted ultra-high resolution synchrotron radiation x-ray diffraction experiments on a high-quality CRO single crystal. The temperature-dependent splitting of the 0 0 16 and 0 0 14 reflections, which are allowed and forbidden, respectively, in the high-temperature cubic phase I (space group Fd–3m), has been clearly observed and reveals the following significant facts: inversion symmetry breaking and tetragonal distortion occur simultaneously at T
s1 = 201.5(1) K; the previously believed first-order transition between phase II (I–4m2) and phase III (I4122) at T
s2 ∼120 K consists of two close second-order transitions at T
s2 = 115.4(1) K and T
s3 ∼ 100 K; there is a new orthorhombic phase XI (F222) in between. The order parameters (OPs) of these continuous transitions are uniquely represented by a two-dimensional irreducible representation Eu
of the Oh
point group, and the OPs of phase XI are a linear combination of those of phases II and III. Each phase is believed to correspond to a distinct odd-parity multipole order, and the complex successive transitions observed may be the result of an electronic phase transition that resolves the Fermi liquid instability in the SOCM.
Liquid holdup modeling analysis in horizontal gas–liquid slug flow
Authors: Wei Furong , Liang Yujiao , Pang Bin , Li Xiaoting , Wang Fan , Zhu Yan , Zhao Ning
Published: November 2022

In slug flow, the wetted wall fraction and liquid holdup of the liquid film section are key parameters affecting the mass transfer and radial velocity distribution of the liquid film, the friction pressure drop, the momentum transfer between the two phases, and heat transfer characteristics. A modified wetted wall fraction and liquid holdup model based on the modified apparent rough surface (MARS) model is proposed in this study, which considers the friction coefficient and shear stress on the gas–wall, liquid–wall and gas–liquid interfaces and introduced the modified average interface velocity of the liquid film. Air–water slug flow experiments were in a 50 mm diameter acrylic glass pipe equipped with a high-speed camera. The edge detection operator was optimized to obtain the wetted wall fraction and liquid holdup at the liquid film section based on image analysis technology. A comparative analysis of the model performance shows that the mean absolute percentage error (MAPE) of the wetted wall fraction model is 9.4%, and the 96.1% relative deviations are within the ±20% error band. The MAPE of the liquid holdup model is 8.04%, and 93.4% relative error is within the ±25% error band. The modified MARS model has good prediction ability for the wetted wall fraction and liquid holdup of the gas–liquid slug flow.
Siamese multiscale residual feature fusion network for aero-engine bearing fault diagnosis under small-sample condition
Authors: Hou Zhao-Guo , Wang Hua-Wei , Lv Shao-Lan , Xiong Ming-Lan , Peng Ke
Published: November 2022

Implementing condition monitoring and fault diagnosis of aero-engine bearings is crucial to ensure that aircraft operate safely and reliably. In engineering practice, the fault data for aero-engine bearings are extremely limited. However, the traditional fault diagnosis methods have two shortcomings under extremely small sample conditions: (1) they have limited diagnostic performance and generalization ability, and (2) they do not mine fault information sufficiently or efficiently. This article proposes a Siamese multiscale residual feature fusion network (SMSRFFN) for aero-engine bearing fault diagnosis under small-sample conditions to overcome the weaknesses above. In the proposed SMSRFFN, the training samples are first paired according to the matching rules to realize the expansion of the sample size. Second, a multiscale residual feature extraction network (MSRFEN) is constructed to excavate the fault features of different scales and speed up the convergence speed of the network. Then, a multiscale attention mechanism feature fusion module (MSAMFFM) is designed to achieve efficient fusion of fault features at different scales. Finally, the distance of the input sample is measured based on the fused deep feature representation to identify the fault state of the aero-engine bearing. The proposed SMSRFFN is evaluated using three bearing fault data and also compared with some state-of-the-art small-sample diagnostic methods. The experimental results demonstrate the effectiveness and superiority of the proposed SMSRFFN in mining fault information and improving diagnosis accuracy under extremely small sample conditions.
Cyclic transitions of DNA origami dimers driven by thermal cycling
Authors: Chen Zhekun , Chen Kuiting , Xie Chun , Liao Kangchao , Xu Fei , Pan Linqiang
Published: November 2022

It is widely observed that life activities are regulated through conformational transitions of biological macromolecules, which inspires the construction of environmental responsive nanomachines in recent years. Here we present a thermal responsive DNA origami dimers system, whose conformations can be cyclically switched by thermal cycling. In our strategy, origami dimers are assembled at high temperatures and disassembled at low temperatures, which is different from the conventional strategy of breaking nanostructures using high temperatures. The advantage of this strategy is that the dimers system can be repeatedly operated without significant performance degradation, compared to traditional strategies such as conformational transitions via i-motif and G-quadruplexes, whose performance degrades with sample dilution due to repeated addition of trigger solutions. The cyclic conformational transitions of the dimers system are verified by fluorescence curves and AFM images. This research offered a new way to construct cyclic transformational nanodevices, such as reusable nanomedicine delivery systems or nanorobots with long service lifetimes.
The influence of humidity on positive streamer propagation in long air gap
Authors: Starikovskiy A Yu , Bazelyan E M , Aleksandrov N L
Published: November 2022

A 2D numerical simulation of the positive streamer properties was performed in 9–12 cm plane-to-plane air gaps for various pressures and water vapor contents. It was shown that an increase in air humidity leads to hampering the streamer development and to increasing the average critical electric field required for bridging the discharge gap. The effect of humidity was most profound at atmospheric pressure and decreased with decreasing pressure. The influence of water content on the streamer properties was explained by a decrease in the streamer channel conductivity due to dissociative recombination of electrons with positive hydrated ions and enhanced three-body electron attachment to O2 molecules. The calculated critical electric field and streamer velocity in humid air gaps were compared with available experimental data.
Emission and capture characteristics of electron trap (E
emi = 0.8 eV) in Si-doped β-Ga2O3 epilayer
Authors: Qu Haolan , Chen Jiaxiang , Zhang Yu , Sui Jin , Gu Yitian , Deng Yuxin , Su Danni , Zhang Ruohan , Lu Xing , Zou Xinbo
Published: November 2022

By deep level transient spectroscopy (DLTS), emission and capture behaviors have been explicitly investigated for a single electron trap in a Si-doped β-Ga2O3 epilayer. Trap characteristics including activation energy for emission (E
emi = 0.8 eV), capture cross-section of 6.40 × 10−15 cm2 and lambda-corrected trap concentration (N
Ta) of 2.48 × 1013 cm−3 were revealed, together with non-emission region width (λ = 267.78 nm). By isothermal DLTS, in addition to the impact of temperature, electric-field-enhanced trap emission kinetics were studied. When a relatively low electric field was applied (E ⩽ 1.81 × 105 V cm−1 at 330 K), emission kinetics of the trap was modeled to comply with phonon-assisted tunneling, whereas the emission process was regarded to be dominated by direct tunneling for a relatively high electric field (E ⩾ 1.81 × 105 V cm−1 at 330 K). A thermal-enhanced capture process has also been disclosed and quantitatively studied, where a capture barrier energy of 0.15 eV was extracted.
The new formulation of Hamiltonian second order continuous systems of Riemann-Liouville fractional derivatives
Authors: Alawaideh Yazen M , Al-khamiseh Bashar M
Published: November 2022

In this study, we first generalized the Hamilton formulation for continuous systems with second-order fractional derivatives and applied it to Podolsky’s generalized electrodynamics. Then, we compared the outcomes to those obtained using Dirac’s approach. This approach was primarily intended to validate Podolsky’s generalized electrodynamics. Using this technique, a combined Riemann-Liouville fractional derivative operator and a fractional variational theory are produced. Fractional Euler equations and fraction Hamilton equations are created using the fraction variational notion. The Hamiltonian equations of motion are compatible with the Euler–Lagrange equations.
Seizure onset zone classification based on imbalanced iEEG with data augmentation
Authors: Zhao Xuyang , Sole-Casals Jordi , Sugano Hidenori , Tanaka Toshihisa
Published: November 2022

Objective. Identifying the seizure onset zone (SOZ) in patients with focal epilepsy is the critical information required for surgery. However, collecting this information is challenging, time-consuming, and subjective. Some machine learning methods reduce the workload of clinical experts in intracranial electroencephalogram (iEEG) visual diagnosis but face significant challenges because interictal iEEG clinical data often suffer from a significant class imbalance. We aim to generate synthetic data for the minority class. Approach. To make the clinically imbalanced data suitable for machine learning, we introduce an EEG augmentation method (EEGAug). The EEGAug method randomly selects several samples from the minority class and transforms them into the frequency domain. Then, different frequency bands from different samples are used to compose new data. Finally, a synthetic sample is generated after converting the new data back to the time domain. Main results. The imbalanced clinical iEEG data can be balanced and applied to machine learning models using the method. A one-dimensional convolutional neural network model is used to classify the SOZ and non-SOZ data. We compare the EEGAug method with other data augmentation methods and another method of class-balanced focal loss function, which is also used for solving the data imbalance problem by adjusting the weights between the minority and majority classes. The results show that the EEGAug method performs best in most data. Significance. Data imbalance is a widespread clinical problem. The EEGAug method can flexibly generate synthetic data for the minority class, yielding synthetic and raw data with a high distribution similarity. By using the EEGAug method, clinical data can be used in machine learning models.
Evaluation of ecological environment carrying capacity of mineral resources exploitation - Take Shenzhen as an example
Authors: Qin Jianqiao , Liu Hao , Zhao Huarong , Gu Fuxing , Jiang Donghang , Zhu Zhixi , Hou Jinxiang
Published: November 2022

The assessment of eco-environmental carrying capacity is the focus of planning environmental impact assessment and an important basis for determining whether the planning can be implemented. Based on the theory and method of ECO-environmental impact assessment, this paper applies the analytic hierarchy process (AHP) to analyze the ecological resilience, resource-environment carrying capacity and mining pressure of mineral resources. A comprehensive evaluation model of environmental impact of mineral resources exploitation is established. Taking Shenzhen City, Guangdong Province as an example, the difference of eco-environmental carrying capacity of the main planned mining areas is evaluated. The results show that the pressure bearing degree of most of the assessed blocks is less than 1, indicating that the pressure on the ecosystem is less than the carrying capacity. The ecosystem is not easy to change and can be restored to the original state in a short time after change, and the ecosystem can maintain normal development. This is of great guiding significance to the scientific formulation of mineral resources exploitation strategy.
Magnetic activated carbon optimization using response surface approach for Cr(VI)
Authors: Yao Wenxuan , Tai Dezhi , Zeng Honghu , Zhang Hua , Huang Haiyi
Published: November 2022

Magnetic activated carbon (Fe3O4-AC) is made using Fe3O4 and activated carbon as primary materials to adsorb Cr(VI) in simulated wastewater. The Response Surface Method (RSM) optimizes the experimental parameters (pH, temperature, initial solution concentration, and activated carbon dosage). The impacts of various elements are explored to determine the ideal reaction conditions for maximum elimination. According to the data, the interaction between pH and the other three parameters is exceptionally significant (P<0.0001) in the experimental response. Furthermore, a maximum removal rate of 83.88 percent may be attained at pH=2, temperature 62°C, starting Cr(VI) concentration 179mg/L, and activate carbon dosage 0.14g/50mL.
Application of a modified graphite paste electrode to the detection of fluorene in fuscous latices
Authors: Liu Yu , Luo Qi , Tian Qiping , Xu Wen , Hu Huili , Shi Li
Published: November 2022

A graphite paste electrode (GPE) was obtained by immobilizing graphene, and the electrocatalytic activity of fluorene (Flu) was studied. The voltammetric behavior using graphene-modified GPE showed an irreversible redox reaction for Flu-ACN-KClO4. A good linear correlation between anodic I and C
Flu ranged within 8–300 ng mL−1. Therefore, we recommend a facile synthesis of modified GPE impregnated with Flu, which matched the concept of analytical minimalism. The electrochemical detection method combined with portable potentiostat is promising to be used for the field tests of Flu in fuscous latices as well as other polycyclic aromatic hydrocarbons.
Management and suggestion of ecological flow guarantee of key rivers and lakes in the Yangtze River Basin
Authors: Deng Zhimin , Shen Dandan , Zhang Keke
Published: November 2022

In this paper, inter-provincial key rivers and lakes (KRLs) and their ecological flow (eco-flow) targets that have been issued and implemented, were taken as the research object. Based on the daily data of eco-flow at each control section, the eco-flow guarantee situation of the KRLs from 2020 to 2021 was analyzed, showing that except Dashadian section, the eco-flow at other sections was all up to the standard. And the reason of target dissatisfaction is that the discharge of two power stations located in the upstream of Dashadian section did not meet the requirements due to their maintenance. Moreover, the accomplishments and problems of eco-flow management were summarized. Furthermore, in the terms of dispatching management, monitoring and early warning, supervision and management, and further research, suggestions and measures were put forward to provide reference for the follow-up eco-flow management.
Analysis uneven selective catalytic reduction flow field of coal-fired units under the situation of double carbon
Authors: Meng Fanliang , Wang Xueli , Qiu Huahai , Feng Qianwei
Published: November 2022

With the implementation of China’s carbon peaking and carbon neutralization strategy and the accelerating transformation of energy structure, higher requirements are put forward for the carbon reduction and operation and maintenance capacity of coal-fired units. Based on the analysis of the uneven Selective catalytic reduction flow field of a coal-fired unit in a power plant, the field tests under different conditions are used to study the inlet flow field distribution and outlet NOx concentration distribution of the denitration device of the unit, and the targeted optimization, adjustment of ammonia injection branch pipe is carried out, which effectively solves the uneven Selective catalytic reduction denitration flow field and can provide reference for similar units.
Big data analytics for adaption to climate change
Authors: Wang Haijing , Wang Yaping
Published: November 2022

Big data analytics (BDA) has the 5-v benefit of volume, variety, veracity, velocity, and value and has the potential to help adaptation to climate change. This paper reports the preconditions for designing the BDA system specifically for adapting to climate change, the designing of this BDA system, and the actual performance. In terms of layers, the components of the BDA system have five integrated layers: the persistent layer, the distributed data storage indexing layer, the web-based data analytics layer, the web-based layer responding to web-based requesting portals, and the web portal layers for specialist administrators to make responses. The BDA system includes the primary database, the sectoral database, and the integration process. The BDA generally met the preconditions and the goals of improving the adaptation capacity to climate change. The trial use of this BDA covered seven provinces in terms of geographic areas and covered preventing flood, tracing diseases caused by climate change, zoning and planning urban areas, and other fields in terms of content. The actual performance indicates that this BDA system functions well as to the speed of processing, the soundness of analysis, and the accuracy of data. However, there is still a need to improve its capacity to spot and detect erroneous but non-conflicting data.
A study of the urban heat island effect in Guangzhou
Authors: Tang Chi Fong
Published: November 2022

As the world economy continues to grow and energy consumption increases, the global climate is gradually warming. Among them, the economic activities in metropolitan areas are more intense compared to other areas, forming an urban heat island effect where the temperature in the urban area is higher than that in the surrounding areas. This article selects Guangzhou, a rapidly developing city in southern China over the past two decades, as a case study. Surface temperature data for five time periods, namely 2000, 2005, 2010, 2015 and 2020, are collected to analyse how Guangzhou is affected by the urban heat island effect and its relationship with land use status and population density. The results of the article found that the urban heat island effect in Guangzhou is very obvious, mainly in the central and southern parts of the city, where the spatial distribution and evolution of land use type and population density are significantly related to the intensity of the heat island effect. In the future, Guangzhou can alleviate the impact of climate change and urban heat island effect by rationally planning urban layout, optimizing urban ecological environment, improving the material of urban underlying surface and actively developing renewable energy.
Research on the measurement of contribution value of scientific and technological talents in China’s mining industry——Innovative application based on “Cobb Douglas production function method”
Authors: Xie Tianheng , Zhu Xueyi
Published: November 2022

This paper aims to determine the contribution value of scientific and technological talents from Mining to national economic development, with data collecting on the correlations between the national Mining and the national economic development from 2005 to 2019, comprising the added value, the capital formation and the total wages and growth rate of the Mining. Through the Cobb-Douglas production function method, the contribution index of Mining talents was confirmed. Combining this index with high-tech talents, the contribution value of Mining science and technology talents was calculated and determined by using big date and informatization method. The results show that in 2005, the contribution value of scientific and technological talents in China’s mining industry in enterprise scientific and technological research and development was 2288.4 yuan / person year, which increased to 3821.1 yuan / person year in 2018, with an average annual increase of 4.01%, 16 years average 7011.1 yuan / person year. This value is much lower than the contribution of capital, and its output elasticity (index) is only 7.42% of capital. However, this is the result of the scientific and technological talents in the mining industry with the value of selfless dedication. It is the real motivation and purpose of the author to write this paper: appeal to the state, society and enterprises to increase the scientific and technological investment in the mining industry and constantly improve the conditions and treatment of scientific and technological talents in the mining industry.
Ecological study on native plant diversity in Kuwait desert ecosystem
Authors: Ahmed Modi , Saleh Abeer Al , Dousari Noor Al
Published: November 2022

The scarcity and irregularity of rainfall and the prevalence of strong northwesterly winds in Kuwait have a significant influence on the stability of the fragile ecosystem. The Aeolian landforms constitute most of the landscapes in Kuwait. Naturally grown native shrubs and trees can provide potential shelter to the soil surface in desert areas. To identify the characteristics of dominant perennial plant species, sediments of desert and saline (sabkhas) nabkha formed around different types of desert and halophytes plants are studied. Haloxylon salicornicum, Nitraria retusa, Cyperus conglomerates, Panicum turgidum, Rhanterium epapposum, Calligonum polygonoides, Stipagrostis plumosa Lycium shawii, Astragalus spinosus, Convolvolus oxyphyllus, Tamarix aucheriana, Halocnemum strobilaceum, and Citrullus colocynthis are landmarks characterizing the Arabian deserts and coastal salt marshes. The analyses of soil samples around the native plants showed that each native plants has its characteristics. The sediments of desert nabkhas differ from coastal nabkhas (Nitraria sp., Halocnemum sp., and Tamarix sp.). The sediments of coastal nabkha were characterized by lower pH, higher moisture content, total dissolved salts, and conductivity levels than desert nabkhas. Maximum mobile sediments were trapped by N. retusa, T. aucheriana, H. salicornicum, C. colocynthis, and L. shawii because of their ability to develop wider and longer nabkhas than other native plants. The vegetated dunes can trap maximum mobile sediments from 0.5 to 10.5 tons thus cost-saving per plant is estimated to be from 0.3 to 7.3 USD.
Changes in land use land cover within the Jukskei River basin and its implications on the water availability
Authors: Moeketsi P. , Nkhonjera G.K. , Alowo R.
Published: November 2022

South Africa is just slowly emerging from its past turbulent history with some of its population still not able to access some of the basic services such as water. This study was aimed at evaluating changes in land use land cover within the Jukskei River basin and its implications on the water availability. The study used Archydro tools on ArcMap of the ArcGIS program to delineate the Jukskei River catchment, then, used the delineated catchment to clip off the land use land cover (LULC) maps for the periods 1990, 2014 and 2020. The total area of the catchment was determined to be 800 km2, and land use practices were assessed for 1990, 2014 and 2020 LULC maps. The major land use classifications found within the catchment were agriculture, bare-land, forests, grassland, settlements (built-up area), mines, waterbodies, and wetlands. The study showed that settlements accounted for the greatest portion of the Jukskei River catchment, compared to other land use categories. The runoff was determined for the 2, 5, 10 and 20 years return periods. The study showed that runoff increased by 8.33% due to 2020 land uses (70% imperviousness), from those values calculated for 1990 and 2014 land uses which had 60.87 and 61.58% imperviousness respectively. Therefore, the results revealed that a large quantity of water (runoff) is generated in the catchment and then surrendered into the Limpopo River and eventually wasted into the Indian Ocean. The study also showed that an increase in imperviousness due to land use practices resulted in an increase in surface runoff, thus having negative implications on the catchment’s water availability.