bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluctuations of the ground surface at blasting operations on tunnel structures
Authors: Ishmamatov Matlab , Kulmuratov Nurillo , Kuldashov Nasriddin , Choriev Mirjalol , Axmedov Nasriddin
Published: August 2023

The paper considers the fluctuations of the ground surface during blasting operations on tunnel structures. To estimate the vibration levels of the soil surface, under the explosive action inside a cylindrical cavity, we will consider the plane problem of elasticity theory as a first approximation. The main purpose of the work is to determine the stress-strain state of pipelines under the influence of seismic waves. As a result of this impact, longitudinal and transverse waves will propagate in the ground. To solve the problem, the reciprocity theorem is applied, for dynamic problems of elasticity theory and the results obtained are compared by wave dynamics methods. The obtained solution makes it possible to determine the vibration levels of the soil surface that occur during explosive impacts inside the cylindrical cavity of the elastic half-space. The results can be used to assess the vibration levels of the soil surface that occur in the structures of shallow tunnels laid by drilling and blasting.
Methods of formulation and theoretical solution of the mathematical problem of designing special clothing protective against high air temperature in the “human-special clothing-environment” system
Authors: Pulatova Sabokhat , Turaeva Nafisa
Published: August 2023

The article presents the methods of formulating and theoretically solving the mathematical problem of designing special clothing that protects against high temperatures in the system “person-special clothing-outdoor environment”. To solve the problem, the human body is assumed to be a deformable cylindrical body of limited size, and special clothing is assumed to be its soft shell. The developed mathematical model makes it possible to predict the dimensions of special clothing, material thickness, cross-sectional area of the underlayer (freedom of clothing) and thermal resistance indicators at the design stage, depending on the air temperature of the external environment.
Anästhesiologische Verfahren bei abdominellen Eingriffen
Authors: Beginn Florian
Published: August 2023

Im Bereich der Gynäkologie ist der Uterus das am zweithäufigsten von Krebserkrankungen betroffene Gewebe. Im Jahr 2018 betrug die Inzidenz in Deutschland 25,9/100 000 Frauen, insgesamt gab es in diesem Jahr 10 860 Neuerkrankungen 1. Entsprechend oft werden Patientinnen mit einer solchen Erkrankung in der Abteilung des Autors während und nach operativen Eingriffen betreut. Anhand eines exemplarischen Falls werden im Folgenden die verwendeten anästhesiologischen Verfahren und ihre Besonderheiten beleuchtet.
Intramolecular Asymmetric Cyclopropanation Using Air-Stable Alkylboronic Esters
Authors: Vedani Luca , Gnägi-Lux Manuel , Dénès Fabrice , Renaud Philippe
Published: August 2023

The preparation of polysubstituted bicyclo[3.1.0]hexanes starting from air-stable substituted pent-4-en-1-ylboronic acid esters has been investigated. The method involves a Matteson homologation with LiCHCl2, leading to 1-chlorohex-5-en-1-ylboronic acid ester intermediates. The subsequent intramolecular cyclopropanation step was performed in a one-pot process. With pinacol boronic esters, the cyclopropanation step was either performed thermally at 140 °C or at 70 °C after in situ transesterification to form a catechol boronic ester. This last approach is suitable for the preparation of enantioenriched bicyclo[3.1.0]hexanes using either chiral-auxiliary control or by taking advantage of the sparteine-controlled enantioselective boroalkylation of alcohols.
A theoretical model for structure inclination angles in stratified boundary layers: Connecting turbulent scaling and Monin–Obukhov similarity theory
Authors: Huang Haojie , Li Xuebo
Published: August 2023

Although scaling laws and coherent structures have been well-studied in non-neutral boundary layer flows over a long period of time, a potential connection between them is still worth exploring. This work explores the structure inclination angle under non-neutral stratification conditions by way of a connection between turbulent scaling and Monin–Obukhov similarity theory. A model for theoretical structure inclination angles is built by extending the refined “turbulent eddy” model of H.-J. Huang [Phys. Rev. Fluids 4, 114702 (2019)] under stratified stability conditions. The variations in the inclination angle values with the stability parameter from the current model are found to be in good agreement with results from the literature, laboratory results, and atmospheric surface layer observations. In addition, the results show that increasing positive/negative buoyancy leads to increasing/decreasing inclination angles and steeper/moderate angles at higher wall-normal heights. This variation is parameterized and can be used to improve existing near-wall models.
A fully resolved smoothed particle hydrodynamics-discrete element method study of the rheology of suspensions: The role of inertia and grain shape
Authors: Li Y. T. , Guo N. , Yang Z. X. , Zhao J. D.
Published: August 2023

This paper presents a numerical study on suspensions of monodisperse non-Brownian grains in a Couette flow. The fully resolved coupled smoothed particle hydrodynamics and discrete element method is employed to model the motion of arbitrarily shaped grains in a viscous fluid. The numerical method is benchmarked against its capability in accurately handling grain–fluid hydrodynamics and inter-grain collisions. It is then used to simulate suspension flows of varying particle Reynolds and Bagnold numbers subjected to different shear rates, solid concentrations, and solid-to-fluid density ratios. A special focus is placed on the effect of grain shape with different aspect ratios and convexities on the flow behavior. Both the inertia and the grain shape are found to affect the grain–fluid and inter-grain interactions and uniquely contribute to the overall shear stress and the rheology of the suspension. The local profiles of solid concentration suggest the presence of grain layering near the boundary walls, which becomes more pronounced with higher solid concentration and inertia, and increased non-circularity in grain shape. A further examination of the pair distribution function and average particle rotation reveals a strong correlation between suspension viscosity and grain microstructure and kinematics.
The Clinical Trials Assistance Pilot: reducing the financial burden of cancer clinical trials for patients in regional New South Wales
Authors: Luiten-Apirana Pareoranga , Gendi Monica , Bernard Jai , Li Zhicheng , Edge Rhiannon , Gellert Bradley , Miller Annie , Mury Maria , Sansey Niki , Jasicki Lindsey , Stolp Sean
Published: August 2023

Objective This study investigated whether the provision of financial assistance to patients living in regional New South Wales influenced patients’ decisions to participate in a cancer clinical trial (cancer treatment or supportive care) and resulted in improved psychosocial outcomes. Methods Administrative data were collected from participants, including demographics, travel distances and the value of financial support provided. Qualitative interviews were then conducted with a subset of consenting patients who received financial assistance for a clinical trial. Results Sixty-four patients with cancer received financial support for a clinical trial, 27 (42%) of whom were interviewed. Participants whose distance to a trial site was over 400 km received almost three times as much financial support (M = A$3194.20, s.d. = A$1597.60) as participants whose distance to a trial site was between 50 and 100 km (M = A$1116.29, s.d. = $A1311.23). Half of participants indicated that receiving financial assistance influenced their decision to participate in a clinical trial, and most indicated the support alleviated the financial burden of clinical trial participation. Conclusions The provision of financial assistance to patients living in regional areas may reduce inequities in cancer clinical trial participation and improve psychosocial outcomes.
The supramolecular chemistry of protein cages and viruses
Authors: Lau Yu Heng
Published: August 2023

There are many examples of protein cages in nature, from the outer capsid shells of viruses that protect their genetic material, to simple organelle-like structures in bacteria that house enzymes within their interior. This Account serves to introduce the world of protein cages to a chemical audience, and highlight the many similarities to concepts from supramolecular chemistry, revealing how a knowledge base in chemistry can provide the foundation for valuable insights into fundamental questions and biomolecular engineering challenges in the field.
Bcl6
,
Irf2
, and
Notch2
promote nonclassical monocyte development
Authors: O’Connor Kevin W. , Liu Tiantian , Kim Sunkyung , Briseño Carlos G. , Georgopoulos Katia , Murphy Theresa L. , Murphy Kenneth M.
Published: August 2023

Ly6C
lo
monocytes are a myeloid subset that specializes in the surveillance of vascular endothelium. Ly6C
lo
monocytes have been shown to derive from Ly6C
hi
monocytes. NOTCH2 signaling has been implicated as a trigger for Ly6C
lo
monocyte development, but the basis for this effect is unclear. Here, we examined the impact of NOTCH2 signaling of myeloid progenitors on the development of Ly6C
lo
monocytes in vitro. NOTCH2 signaling induced by delta-like ligand 1 (DLL1) efficiently induced the transition of Ly6C
hi
TREML4
–
monocytes into Ly6C
lo
TREML4
+
monocytes. We further identified two additional transcriptional requirements for development of Ly6C
lo
monocytes. Deletion of BCL6 from myeloid progenitors abrogated development of Ly6C
lo
monocytes. IRF2 was also required for Ly6C
lo
monocyte development in a cell-intrinsic manner. DLL1-induced in vitro transition into Ly6C
lo
TREML4
+
monocytes required IRF2 but unexpectedly could occur in the absence of NUR77 or BCL6. These results imply a transcriptional hierarchy for these factors in controlling Ly6C
lo
monocyte development.
A note on the Kaluza–Klein theory
Authors: Li Li-Xin
Published: August 2023

We show that the Kaluza–Klein (KK) theory contains a fundamental problem: The four-dimensional metric tensor and the electromagnetic potential vector assumed in the KK theory belong to four-dimensional vector spaces that are not integrable in general, resulting that the four-dimensional physical variables and the corresponding field equations derived from the five-dimensional Einstein field equation (i.e. the four-dimensional Einstein field equation and the Maxwell equations) are not defined on a four-dimensional submanifold. That is, the four-dimensional spacetime assumed in the KK theory does not exist. No satisfactory solutions are found within the KK formalism. Perhaps the best approach to fix the problem is giving up the KK theory and looking for a new unified scheme for gravitational and electromagnetic interactions in the framework of a spacetime with extra dimensions, as having already been explored in some literature.
A SINS/GNSS/2D-LDV integrated navigation scheme for unmanned ground vehicles
Authors: Xiang Zhiyi , Zhang Tao , Wang Qi , Jin Shilong , Nie Xiaoming , Duan Chengfang , Zhou Jian
Published: August 2023

In recent years, unmanned autonomous driving technology has attracted increasing attention from people, and become a research hotspot. Currently, the integration of strapdown inertial navigation system (SINS) and global navigation satellite systems (GNSSs) is the most common and effective navigation and positioning scheme for unmanned ground vehicles (UGVs) and unmanned aerial vehicles. However, this integrated system is unable to maintain a reliable positioning solution in challenging environments due to the inherent weakness of GNSS signals and the accumulation of SINS positioning errors over time. To address this issue, this paper proposes an integrated scheme based on an asynchronous Kalman filter for SINS, GNSS and two-dimensional (2D) laser Doppler velocimeter (LDV). In the proposed scheme, the SINS and 2D-LDV are tightly coupled to improve the robustness of the integrated system, and the error parameters between the 2D-LDV and the SINS are calibrated in real time during the validity of the GNSS signal. In addition, the designed asynchronous Kalman filter method evaluates the validity of the GNSS and 2D-LDV measurements in real time based on Mahalanobis distance of innovation vector and statistical property principle. Two groups of long-distance, high-mobility vehicle experiments conducted in challenging environments verify the validity of the proposed scheme. The experimental results show that the proposed SINS/GNSS/2D-LDV integrated navigation scheme has good environmental adaptability and reliability, and can maintain high horizontal and vertical positioning accuracy despite frequent GNSS signal failures, which can meet the needs of UGVs.
Effects of vacancy concentration on the edge dislocation motion in copper by atomic simulations
Authors: Chen Wenjin , Li Run , Yao Songlin , Zhu Wenjun , Li Xiaofan , Fang Jingzhong , Wang Kun
Published: August 2023

Nonequilibirum vacancy concentration widely appears in crystals under many extreme loading conditions, but receives relatively few attentions. In this work, we systematically explore the influence of a serial of different vacancy concentrations on the edge dislocation motion in copper using molecular dynamics (MD) simulations. Our result shows that the vacancy would hinder the dislocation motion, but the mechanism depends on the detailed dislocation motion regions. In thermally activated region, its influence is mainly reflected by modifying the dynamic and static threshold stresses required for edge dislocation initiation and continuous motion. In the linear region, the hindering mechanism is gradually transformed from phonon damping to vacancy pinning with the increasing vacancy concentration. In contrasts, the dislocation structure is almost unchanged under different vacancy concentrations in the non-linear region. Under high applied stress, high vacancy concentration will cause the dislocation velocity to jump back and forth between transonic and subsonic velocities more frequently. It has been attributed to the reactions between the dislocation and vacancies. The latter may result in dislocation local constriction and climbing. Moreover, a mobility equation suitable for describing edge dislocations at different non-equilibrium vacancy concentrations is proposed, which fits the MD results well. Finally, the roles of the nonequilibirum vacancy concentration on the edge dislocation motion is interpreted using the degrading elastic property and stacking fault energy.
Quantum dots derived from two-dimensional transition metal dichalcogenides: synthesis, optical properties and optoelectronic applications
Authors: Chiu Ching-Hsueh , Chen Yu-Ting , Shen Ji-Lin
Published: August 2023

Zero-dimensional transition metal dichalcogenides (TMD) quantum dots (QDs) have attracted a lot of attention due to their interesting fundamental properties and various applications. Compared to TMD monolayers, the QD counterpart exhibits larger values for direct transition energies, exciton binding energies, absorption coefficient, luminescence efficiency, and specific surface area. These characteristics make them useful in optoelectronic devices. In this review, recent exciting progress on synthesis, optical properties, and applications of TMD QDs is highlighted. The first part of this article begins with a brief description of the synthesis approaches, which focus on microwave-assistant heating and pulsed laser ablation methods. The second part introduces the fundamental optical properties of TMD QDs, including quantum confinement in optical absorption, excitation-wavelength-dependent photoluminescence, and many-body effects. These properties are highlighted. In the third part, we discuss lastest advancements in optoelectronic devices based on TMD QDs These devices include light-emitting diodes, solar cells, photodetectors, optical sensors, and light-controlled memory devices. Finally, a brief summary and outlook will be provided.
Maxwell–Bloch equations without spectral broadening: the long-time asymptotics of an input pulse in a long two-level laser amplifier
Authors: Kotlyarov Volodymyr , Minakov Oleksandr
Published: August 2023

We study the problem of propagation of an input electromagnetic pulse through a long two-level laser amplifier under trivial initial conditions. In this paper, we consider an unstable model described by the Maxwell–Bloch equations without spectral broadening. Previously, this model was studied by Manakov in (1982 Zh. Eksp. Teor. Fiz.
83 68–75) and together with Novokshenov in (1986 Teor. Mat. Fiz.
69 40–54). We consider this model in a more natural formulation as an initial-boundary (mixed) problem using a modern version of the inverse scattering transform method in the form of a suitable Riemann–Hilbert (RH) problem. The RH problem arises as a result of applying the Fokas–Its method of simultaneous analysis of the corresponding spectral problems for the Ablowitz–Kaup–Newell–Segur equations. This approach makes it possible to obtain rigorous asymptotic results at large times, which differ significantly from the previous ones. Differences take place both near the light cone and in the tail region, where a new type of solitons is found against an oscillating background. These solitons are physically relevant, their velocities are smaller than the speed of light. The number of such solitons can be either finite or infinite (in the latter case, the set of zeros has a condensation point at infinity). Such solitons cannot be reflectionless, they are generated by zeros of the reflection coefficient of the input pulse (and not by poles of the transmission coefficient). Thus our approach shows the presence of a new phenomenon in soliton theory, namely, the boundary condition (input pulse) of a mixed problem under trivial initial conditions can generate solitons due to the zeros of the reflection coefficient, while the poles of the transmission coefficient do not contribute to the asymptotics of the solution.
D-SAT: dual semantic aggregation transformer with dual attention for medical image segmentation
Authors: Li Haiyan , Ding Jiayu , Shi Xin , Zhang Qi , Yu Pengfei , Li Hongsong
Published: August 2023

Objective. Medical image segmentation is significantly essential to assist clinicians in facilitating a quick and accurate diagnoses. However, most of the existing methods are still challenged by the loss of semantic information, blurred boundaries and the huge semantic gap between the encoder and decoder. Approach. To tackle these issues, a dual semantic aggregation transformer with dual attention is proposed for medical image segmentation. Firstly, the dual-semantic feature aggregation module is designed to build a bridge between convolutional neural network (CNN) and Transformer, effectively aggregating CNN’s local feature detail ability and Transformer’s long-range modeling ability to mitigate semantic information loss. Thereafter, the strip spatial attention mechanism is put forward to alleviate the blurred boundaries during encoding by constructing pixel-level feature relations across CSWin Transformer blocks from different spatial dimensions. Finally, a feature distribution gated attention module is constructed in the skip connection between the encoder and decoder to decrease the large semantic gap by filtering out the noise in low-level semantic information when fusing low-level and high-level semantic features during decoding. Main results. Comprehensive experiments conducted on abdominal multi-organ segmentation, cardiac diagnosis, polyp segmentation and skin lesion segmentation serve to validate the generalization and effectiveness of the proposed dual semantic aggregation transformer with dual attention (D-SAT). The superiority of D-SAT over current state-of-the-art methods is substantiated by both subjective and objective evaluations, revealing its remarkable performance in terms of segmentation accuracy and quality. Significance. The proposed method subtly preserves the local feature details and global context information in medical image segmentation, providing valuable support to improve diagnostic efficiency for clinicians and early disease control for patients. Code is available at https://github.com/Dxkm/D-SAT.
Bolt tightness monitoring using multiple reconstructed narrowband Lamb waves combined with piezoelectric ultrasonic transducer
Authors: Li Xiuquan , Liu Gaoxi , Sun Qiaolei , Chen Hongbing , Chen Lin , Zhang Minghui , Sun Xiangtao
Published: August 2023

Narrowband tone burst excitation with a carefully selected frequency is generally utilized to generate Lamb waves for mode purity, dispersion diminution and signal interpretability. Narrowband excitation exhibits saturation phenomenon and even non-monotonic trends with the development of bolt looseness. In this research, a piezoelectric ultrasonic transducer with high signal-to-noise ratio is designed and fabricated for bolt tightness monitoring. The chirp signal is utilized to drive the actuator to generate broadband Lamb waves in the connected plate, and a transfer function-based signal reconstruction algorithm is innovatively proposed to extract narrowband tone burst responses with different center frequencies from the broadband chirp response for bolt tightness monitoring. The leaked wave energy-based bolt tightness indexes (TIs) are calculated based on the extracted multiple tone burst responses and a feature-level data fusion strategy is proposed to combine the TIs for exploiting the merits of different-frequency inspecting waves for different bolt tightness conditions. The fused TI not only presents a monotonic tendency with the increasing of bolt tightness, but also tackles the low sensitivity of narrowband Lamb waves for embryo bolt looseness. The proposed method contributes a novel and stable scheme for bolt tightness monitoring and opens a new perspective for damage evaluation of structures.
Controlling qubit-oscillator systems using linear parameter sweeps
Authors: Ashhab Sahel , Fuse Tomoko , Yoshihara Fumiki , Kim Sunmi , Semba Kouichi
Published: August 2023

We investigate the dynamics of a qubit-oscillator system under the influence of a linear sweep of system parameters. We consider two main cases. In the first case, we consider sweeping the parameters between the regime of a weakly correlated ground state and the regime of a strongly correlated ground state, a situation that can be viewed as a finite-duration quench between two phases of matter: the normal phase and the superradiant phase. Excitations are created as a result of this quench. We investigate the dependence of the excitation probabilities on the various parameters. We find a qualitative asymmetry in the dynamics between the cases of a normal-to-superradiant and superradiant-to-normal quench. The second case of parameter sweeps that we investigate is the problem of a Landau–Zener sweep in the qubit bias term for a qubit coupled to a harmonic oscillator. We analyze a theoretical formula based on the assumption that the dynamics can be decomposed into a sequence of independent Landau–Zener transitions. In addition to establishing the conditions of validity for the theoretical formula, we find that under suitable conditions, deterministic and robust multi-photon state preparation is possible in this system.
Diffusion in a bicrystal: effect of water uptake through grain boundary on the degradation of halide perovskites
Authors: Yang Fuqian
Published: August 2023

In this work, we investigate the diffusion in a bicrystal strip with a constant concentration of solute atoms/molecules on free surfaces to mimic the diffusion of water molecules in a bicrystal of halide perovskites. The effect of grain boundary diffusion is incorporated in the analysis, and the equation of mass transport in the grain boundary is derived without a time-derivative term. Using the equation of mass transport in the grain boundary, a closed-form solution of the spatiotemporal evolution of the concentration of solute atoms/molecules in the bicrystal is derived. Numerical analysis of the uptake of water in a methylammonium lead iodide (MAPbI3) bicrystal is performed. The degree of degradation of the MAPbI3 bicrystal due to the uptake of water is defined as the ratio of the diffusion length of water in one of the crystal in the bicrystal to the half width of the bicrystal. The numerical results reveal that the degree of degradation of the MAPbI3 bicrystal increases with the increase of the diffusion time and there exists effect of grain size on the degree of degradation of the MAPbI3 bicrystal. The time to reach the same degree of degradation due to the uptake of water is proportional to the width of the MAPbI3 bicrystal of the same thickness, in accord with the experimental results reported in literature. This result points to the need of producing halide perovskite films of large grain sizes in order to improve the structural stability and performance of perovskite-based photovoltaic cells by limiting the structural degradation induced by water diffusion.
Quantum decay of scalar and vector boson stars and oscillons into gravitons
Authors: Nakayama Kazunori , Takahashi Fuminobu , Yamada Masaki
Published: August 2023

We point out that a soliton such as an oscillon or boson star inevitably decays into gravitons through gravitational interactions. These decay processes exist even if there are no apparent self-interactions of the constituent field, scalar or vector, since they are induced by gravitational interactions. Hence, our results provide a strict upper limit on the lifetime of oscillons and boson stars including the dilute axion star. We also calculate the spectrum of the graviton background from decay of solitons.
Late vacuum choice and slow roll approximation in gravitational particle production during reheating
Authors: Cembranos Jose A.R. , Garay Luis J. , Parra-López Álvaro , Sánchez Velázquez Jose M.
Published: August 2023

In the transition between inflation and reheating, the curvature scalar typically
undergoes oscillations which have significant impact on the density of gravitationally produced
particles. The commonly used adiabatic vacuum prescription for the extraction of produced particle
spectra becomes a non-reliable definition of vacuum in the regimes for which this oscillatory
behavior is important. In this work, we study particle production for a scalar field non-minimally
coupled to gravity, taking into account the complete dynamics of spacetime during inflation and
reheating. We derive an approximation for the solution to the mode equation during the slow-roll
of the inflaton and analyze the importance of Ricci scalar oscillations in the resulting
spectra. Additionally, we propose a prescription for the vacuum that allows to safely extrapolate
the result to the present, given that the test field interacts only gravitationally. Lastly, we
calculate the abundance of dark matter this mechanism yields and compare it to observations.
PT-symmetric electronic dimer without gain material
Authors: Tagouegni Senghor , Fotsa-Ngaffo Fernande , Kenfack-Jiotsa Aurélien
Published: August 2023

In this paper, a way of building an electronic Parity Time (




)-symmetric dimer without gain material is presented. This is achieved by capacitively coupling a pair of LZC circuits, each combining an inductance L, an imaginary resistance Z and a positive/negative capacitance C. We derive the effective Hamiltonian of the system, which commutes with the joint




operator. The eigenspectrum displays spontaneous breaking points, where the system undergoes a transition from real to complex values. The transition points are imposed by the range value of the coupling thanks to the use of a negative capacitance. Temporal charge solutions and energy propagation are also analytically and numerically investigated, and the results are compatible. In the exact phase, these quantities oscillate, whereas in the broken phase, oscillations disappear, giving place to amplification. Our results pave the way to innovative




-symmetric circuits. Applications could include, among others, optics, metamaterials, photonics and sensitive detection.
Investigation of the Rayleigh–Taylor instability in charged fluids
Authors: Zhang Weiping , Li Zhongzheng , Duan Wenshan
Published: August 2023

The present study shows that the Rayleigh–Taylor (RT) instability and its growth rate are strongly dependent on the charge-mass ratio of charged particles in a charged fluid. A higher charge-mass ratio of the charged fluid appears to result in a stronger effect of the magnetic field to suppress the RT instability. We study the RT instabilities for both dusty plasma (small charge-mass ratio of charged particles) and ion-electron plasma (large charge-mass ratio of charged particles). It is found that the impact of the external magnetic field to suppress the RT instability for ion-electron plasma is much greater than that for dusty plasma. It is also shown that, for a dusty plasma, in addition to region parameters such as the external magnetic field, region length, its gradient, as well as dust particle parameters such as number density, mass, and charge of dust particles, the growth rate of the RT instability in a dusty plasma also depends on parameters of both electrons and ions such as the number densities and temperatures of both electrons and ions.
Nondegenerate solitons of the (2+1)-dimensional coupled nonlinear Schrödinger equations with variable coefficients in nonlinear optical fibers
Authors: Yang 杨 Wei 薇 , Cheng 程 Xueping 雪苹 , Jin 金 Guiming 桂鸣 , Wang 王 Jianan 佳楠
Published: August 2023

We derive the multi-hump nondegenerate solitons for the (2+1)-dimensional coupled nonlinear Schrödinger equations with propagation distance dependent diffraction, nonlinearity and gain (loss) using the developing Hirota bilinear method, and analyze the dynamical behaviors of these nondegenerate solitons. The results show that the shapes of the nondegenerate solitons are controllable by selecting different wave numbers, varying diffraction and nonlinearity parameters. In addition, when all the variable coefficients are chosen to be constant, the solutions obtained in this study reduce to the shape-preserving nondegenerate solitons. Finally, it is found that the nondegenerate two-soliton solutions can be bounded to form a double-hump two-soliton molecule after making the velocity of one double-hump soliton resonate with that of the other one.
Progress and realization platforms of dynamic topological photonics
Authors: Yan 闫 Qiu-Chen 秋辰 , Ma 马 Rui 睿 , Hu 胡 Xiao-Yong 小永 , Gong 龚 Qi-Huang 旗煌
Published: August 2023

Dynamic topological photonics is a novel research field, combining the time-domain optics and topological physics. In this review, the recent progress and realization platforms of dynamic topological photonics have been well introduced. The definition, measurement methods and the evolution process of the dynamic topological photonics are demonstrated to better understand the physical diagram. This review is meant to bring the readers a different perspective on topological photonics, grasp the advanced progress of dynamic topology, and inspire ideas about future prospects.
Image2Brain: a cross-modality model for blind stereoscopic image quality ranking
Authors: Shen Lili , Li Xintong , Pan Zhaoqing , Sun Xichun , Zhang Yixuan , Zheng Jianpu
Published: August 2023

Objective. Human beings perceive stereoscopic image quality through the cerebral visual cortex, which is a complex brain activity. As a solution, the quality of stereoscopic images can be evaluated more accurately by attempting to replicate the human perception from electroencephalogram (EEG) signals on image quality in a machine, which is different from previous stereoscopic image quality assessment methods focused only on the extraction of image features. Approach. Our proposed method is based on a novel image-to-brain (I2B) cross-modality model including a spatial-temporal EEG encoder (STEE) and an I2B deep convolutional generative adversarial network (I2B-DCGAN). Specifically, the EEG representations are first learned by STEE as real samples of I2B-DCGAN, which is designed to extract both quality and semantic features from the stereoscopic images by a semantic-guided image encoder, and utilize a generator to conditionally create the corresponding EEG features for images. Finally, the generated EEG features are classified to predict the image perceptual quality level. Main results. Extensive experimental results on the collected brain-visual multimodal stereoscopic image quality ranking database, demonstrate that the proposed I2B cross-modality model can better emulate the visual perception mechanism of the human brain and outperform the other methods by achieving an average accuracy of 95.95

%

. Significance. The proposed method can convert the learned stereoscopic image features into brain representations without EEG signals during testing. Further experiments verify that the proposed method has good generalization ability on new datasets and the potential for practical applications.
Consequences for predator–prey dynamics caused by the presence of obstacles
Authors: Šćepanović J R , Budinski-Petković Lj , Jakšić Z M , Belić A , Vrhovac S B
Published: August 2023

In order to understand how a heterogeneous habitat affects the population dynamics of the predator–prey system, a spatially explicit lattice model consisting of predators, prey and obstacles is constructed. The model includes smart pursuit (predators to prey) and evasion (prey from predators). Both species can affect their movement by visual perception within their finite sighting range. Non-conservative processes that change the number of individuals within the population, such as breeding and physiological dying, are implemented in the model. Obstacles are represented by non-overlapping lattice shapes that are randomly placed on the lattice. In the absence of obstacles, numerical simulations reveal regular, coherent oscillations with a nearly constant predator–prey phase difference. Numerical simulations have shown that changing the probabilities for non-conservative processes can increase or decrease the period of coherent oscillations in species abundances and change the relative lag between coherent components. After introducing obstacles into the model, we observe random transitions between coherent and non-coherent oscillating regimes. In the non-coherent regime, predator and prey abundances continue to oscillate, but without a well-defined phase relationship. Our model suggests that stochasticity introduced by density fluctuations of obstacles is responsible for the reversible shift from coherent to non-coherent oscillations.
Mapping the global flows of steel scraps: an alloy elements recovery perspective
Authors: Cai Wenqiu , Geng Yong , Li Meng , Gao Ziyan , Wei Wendong
Published: August 2023

Recycling steel scraps by the use of electric arc furnace is one of the most promising approaches for the steel industry to achieve net-zero emissions. Due to the uneven distribution of global steel scraps, many countries are actively involving in the global steel scraps trade. Steel scraps contain a range of critical elements, which may be transferred across borders through international trade of steel scraps. However, existing studies have paid little attention to the global flows of steel scraps and its embodied alloy elements (AEs). This study maps the journey of global steel scraps and the embodied AEs for the period of 2000–2021 for the first time by employing trade-linked material flow analysis and social network analysis. The results indicate that the global steel scraps trade had increased during the study period, with a few core countries (such as USA, Germany, and Turkey) leading the global steel scraps network. Also, critical metals had been transferred across borders in the form of AEs through the trade of steel scraps, especially from global north countries to global south countries. The largest AE flows include Chromium (Cr), nickel (Ni), manganese (Mn) and molybdenum (Mo) flows. Other AE flows, such as cobalt (Co), vanadium (V), and niobium (Nb) flows, were less, but with high values or being regarded scarce. From a global perspective, steel scraps trade and recycling can contribute to the decarbonization efforts of the global steel industry and address resource shortages in some countries. Therefore, it is urgent to promote the overall resource efficiency of steel scraps and the embodied AEs by various efforts.
Physically-based simulation of elastic-plastic fusion of 3D bioprinted spheroids
Authors: Bahrami Hassan , Sichetti Federico , Puppo Enrico , Vettori Laura , Liu Chung Ming Clara , Perry Stuart , Gentile Carmine , Pietroni Nico
Published: August 2023

Spheroids are microtissues containing cells organized in a spherical shape whose diameter is usually less than a millimetre. Depending on the properties of the environment they are placed in, some nearby spheroids spontaneously fuse and generate a tissue. Given their potential to mimic features typical of body parts and their ability to assemble by fusing in permissive hydrogels, they have been used as building blocks to 3D bioprint human tissue parts. Parameters controlling the shape and size of a bioprinted tissue using fusing spheroid cultures include cell composition, hydrogel properties, and their relative initial position. Hence, simulating, anticipating, and then controlling the spheroid fusion process is essential to control the shape and size of the bioprinted tissue. This study presents the first physically-based framework to simulate the fusion process of bioprinted spheroids. The simulation is based on elastic-plastic solid and fluid continuum mechanics models. Both models use the ‘smoothed particle hydrodynamics’ method, which is based on discretizing the continuous medium into a finite number of particles and solving the differential equations related to the physical properties (e.g. Navier–Stokes equation) using a smoothing kernel function. To further investigate the effects of such parameters on spheroid shape and geometry, we performed sensitivity and morphological analysis to validate our simulations with in-vitro spheroids. Through our in-silico simulations by changing the aforementioned parameters, we show that the proposed models appropriately simulate the range of the elastic-plastic behaviours of in-vitro fusing spheroids to generate tissues of desired shapes and sizes. Altogether, this study presented a physically-based simulation that can provide a framework for monitoring and controlling the geometrical shape of spheroids, directly impacting future research using spheroids for tissue bioprinting.
Non-linear homomorphisms of algebras of functions are induced by thick morphisms
Authors: Khudaverdian Hovhannes
Published: August 2023

In 2014, Voronov introduced the notion of thick morphism of a (super)manifold as a tool for constructing

L

∞

L_{\infty }

-morphisms of homotopy Poisson algebras. A thick morphism generalises an ordinary smooth map, but it is not itself a map. Nevertheless, it induces a pull-back of

C

∞

C^{\infty }

functions. These pull-backs which are in general non-linear maps between algebras of functions are “non-linear homomorphisms”. By definition, this means that their differentials are algebra homomorphisms in the usual sense. The following conjecture was formulated: an arbitrary non-linear homomorphism of algebras of smooth functions is generated by some thick morphism. We prove here this conjecture in the class of formal functionals. In this way, we extend the well-known result for smooth maps of manifolds and algebra homomorphisms of

C

∞

C^{\infty }

functions and, more generally, provide an analog of classical “functional-algebraic duality” in the non-linear setting.
On the Buchstaber–Rees theory of “Frobenius 𝑛-homomorphisms” and its generalization
Authors: Khudaverdian H. , Voronov Th.
Published: August 2023

This is a survey of our results on the theory of

n
n

-homomorphisms of Buchstaber–Rees and its generalization that we obtained. In short, we are concerned with classes of linear maps between commutative rings that can be described as the “next level after ring homomorphisms” with respect to multiplicative properties. Our main tool is a construction which we call the “characteristic function” — whose functional properties encode algebraic properties of a linear map in question. Namely, if the characteristic function is polynomial of degree

n
n

, the map is an

n
n

-homomorphism in the sense of Buchstaber–Rees, and our approach simplifies their theory substantially. If the characteristic function is an irreducible rational fraction with the numerator and denominator of degrees

p
p

and

q
q

respectively, we arrive at a new notion of a “

p

|

q

p|q

-homomorphism”. Examples of

p

|

q

p|q

-homomorphisms are sums and differences of ring homomorphisms. Our construction is motivated by our earlier results in superalgebra/supergeometry concerning Berezinians and super exterior powers.
Differential calculus over graded commutative algebras and vector bundles with inner structures
Authors: Kryczka Jacob
Published: August 2023

In this note we highlight a common origin for many ubiquitous geometric structures, as well as several new ones by using only the functors of differential calculus in A.M Vinogradov’s original sense, adapted to special classes of (graded) commutative algebras. Special attention is given to the particularly simple cases of diole and triole algebras and we show the latter environment is the appropriate one to describe calculus in vector bundles in the presence of a vector-valued fiber metric.
Why we should not assume that ‘normal’ is ambiguous
Authors: Bebb Jon
Published: August 2023

There is a widespread and largely unchallenged assumption within philosophy that the word ‘normal’ is ambiguous: i.e., that it can mean different things in different contexts. This assumption appears in work within topics as varied as the philosophy of biology, medicine, justification, causation, and more. In this paper I argue that we currently lack any independent reason for adopting such an assumption. The reason that would most likely be offered in its favour requires us to ignore an alternative and equally plausible explanation for the seeming variety of different meanings that ‘normal’ is taken to have. Meanwhile, the well-known conjunction reduction test for ambiguity provides no evidence for the ambiguity of ‘normal’, and in fact suggests that maintaining this ambiguity claim is more difficult than has been initially supposed. Therefore, with the way things stand at present, it should not be assumed without argument that ‘normal’ is an ambiguous term.
Nerve Injury and Peripheral Nerve Functional Loss From Injection and Suture Needles: An Experimental Study on Rats
Authors: Fernandes Matheus Scuracchio , Viterbo Fausto , Rodrigues Lorena Delgado , di Luccas Caio Borges , de Menezes Neto Balduino Ferreira
Published: August 2023

Background

During invasive procedures involving needles, there is a chance of damage to peripheral nerves. Therefore, a method for experimentally simulating these situations is needed.

Objectives

In this study we aimed to evaluate peripheral nerve lesions caused by the entry and exit of an injection needle, nerve transfixion through a suture stitch, and the injection of saline solution and lidocaine into the nerve.

Methods

After obtaining approval from the Animal Ethics Committee, we randomly divided 36 Wistar rats, weighing approximately 250 g each, into 6 groups (control, sham, suture, needle, saline, and lidocaine groups), with 6 animals in each group. All procedures were performed on the left paws of the rats. After the procedure, walking track analysis was performed to assess the walking function of rats for 8 weeks. Four months after the procedures, we performed bilateral electrophysiological studies (measuring the latency and amplitude of the electrical impulse in the peroneal nerve). Subsequently, the rats were euthanized, and bilateral tissue samples were collected from the peroneal nerve and tibialis cranialis muscle for morphometric histological analysis.

Results

In the walking track analysis, all groups showed normalization of walking functionality after 13 days. There was little histological change between the groups, and no functional loss related to the procedures was observed.

Conclusions

Procedures involving the infusion of local anesthetic or saline solution, or suture needles, are safe with regard to peripheral nerve function loss. Accidents tend not to cause nerve impairment.
Advancing spatial ontology in evolutionary economic geography
Authors: Chu Han , Hassink Robert
Published: August 2023

Although evolutionary economic geography has been popular in economic geography, it has also been criticized for, among others, a weak geographical conceptualization, which has become evident, particularly in empirical research on related and unrelated variety. Therefore, this paper advances a spatial ontology, which is embedded in critical realism and social constructivism, and will empower evolutionary economic geography to understand and explain the impact of both economic crises and grand societal challenges on regional economic change, in a more place and scale-sensitive manner. Moreover, and relatedly, it will enable a better understanding of the main drivers of regional economic change.
Validation of the ACE [Albumin, CRP, and Endoscopy] Index in Acute Colitis: Analysis of the CONSTRUCT dataset
Authors: Grant Rebecca K , Jones Gareth-Rhys , Plevris Nikolas , Lynch Ruairi W , Brindle William M , Hutchings Hayley A , Williams John G , Alrubaiy Laith , Watkins Alan , Lees Charlie W , Arnott Ian D R
Published: August 2023

Background and Aims

In 2020 we reported the ACE Index in acute colitis which used biochemical and endoscopic parameters to predict steroid non-response on admission in patients with acute ulcerative colitis [UC]. We aimed to validate the ACE Index in an independent cohort.

Methods

The validation cohort comprised patients screened as eligible for inclusion in the CONSTRUCT study, a prospective, randomized, placebo-controlled trial which compared the effectiveness of treatment with infliximab vs ciclosporin in patients admitted with acute UC. The CONSTRUCT cohort database was reviewed at The Edinburgh IBD Unit and the same biochemical and endoscopic variables and cut-off values as those in the derivation cohort were applied to the validation cohort.

Results

In total, 800 patients were identified; 62.5% [55/88] of patients with a maximum ACE Index of 3 did not respond to intravenous [IV] steroids (positive predictive value [PPV] 62.5%, negative predictive value [NPV] 79.8%). Furthermore, 79.8% [158/198] of patients with an ACE Index of 0 responded to IV steroids [PPV 79.8%, NPV 62.5%]. Receiver operator characteristic [ROC] curve analysis produced an area under the curve [AUC] of 0.663 [p < 0.001].

Conclusions

We have now reported and externally validated the ACE Index in acute colitis in a combined cohort of over 1000 patients from across the UK. The ACE Index may be used in conjunction with clinical judgement to help identify patients admitted with active UC who are at high risk of not responding to IV steroids. Further studies are required to improve objectivity and accuracy of assessment.