bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical investigation into rotating instability and the vortex structure near the tip in a transonic compressor rotor
Authors: Chen Zhiyang , Xiang Haiping , Lin Feng , Wu Yanhui , Yang Fan
Published: August 2024

An unsteady simulation with a full-annular computed domain was conducted to explore the flow unsteadiness near the tip region and the mechanism of rotating instability (RI) in the transonic rotor. The numerical static pressure signals were monitored at the tip region. RI was identified by a frequency hump in the spectrum of the static pressure signal in a small mass flow coefficient with a narrow range of 0.9510–0.9174. The cross-power spectrum of two static pressure signals obtained in adjacent passages showed that the circumferential propagation speed of RI decreased with the decrease in the mass flow coefficient. The relative circumferential propagation speed of RI of the prominent mode order was −0.65 to −0.61 times the rotor speed. Details of the flow field near the tip showed that a new vortex structure was induced by the interaction of the tip leakage vortex and the shock wave, which was called as tip secondary vortex (TSV). The TSV was the key parameter to the formation of RI. The impact of the TSV on the pressure side surface generated a low-pressure area and changed the tip load of the adjacent blade. RI is result of the propagation of the interaction between the TSV and the tip load.
Waveguide-based microscope slide for label-free high-resolution imaging
Authors: Yang Songlin , Sun Qihao , Cao Yurong , Ye Yong-Hong , Zhang Jiayu
Published: August 2024

Waveguide-based total internal reflection fluorescence microscopy has been widely adopted due to its excellent signal-to-noise ratio over a large field of view. However, with the increasing demand for label-free imaging, waveguide-based evanescent light scattering microscopy (ESM) has also garnered significant attention. Here, we present a low-cost waveguide-based microscope slide that offers easier integration with conventional optical microscopy. This microscope slide uses an incoherent light source coupled to a lithium tantalate (LT) planar waveguide to generate an evanescent light that illuminates samples located within a few hundred nanometers of the waveguide surface. We perform its application for imaging chromium nanoholes and polystyrene nanospheres, demonstrating its label-free, high-resolution, high-contrast imaging performance. LT waveguide microscope slides provide a simple and effective solution for ESM.
Polyelectrolyte mixture enables electrowetting liquid lens with large optical power tuning range
Authors: Jiang Meng , Peng Qi-Xian , Wang Hai-Feng , Liu Shu-Bin , Li Lei
Published: August 2024

Electrowetting liquid lenses have aroused considerable interest among researchers in a variety of industrial applications and wetting sciences. However, conventional electrowetting liquid lenses face significant limitations in their optical power tuning range due to contact angle saturation. To address this issue, our research introduces a polyelectrolyte mixture (PM) composed of ammonium polyphosphate and potassium chloride, which enables a broad optical power tuning range for electrowetting liquid lenses. Through a comprehensive analysis involving viscosity, Raman spectrum, and contact angle measurements, we offer additional insights into the interdisciplinary mechanism of the PM in enhancing the electrowetting effect. Our investigation elucidates how the conformation of the polyelectrolyte and the formation of hydrogen bonds at varying concentrations can impact the electrowetting gain. By optimizing the electrowetting concentration of the PM (12.5 wt. % ammonium polyphosphate and 7.5 wt. % potassium chloride), we achieve a liquid lens with an extensive tuning range (−37.97 to +18.71 D) at 0–45 V, featuring a substantial aperture (6.4 mm) and a low threshold voltage (10 V). This PM formulation effectively mitigates contact angle saturation, thereby offering promising applications and paving the way for the development of liquid lenses with a significantly enhanced optical power tuning capacity.
A large net carbon loss attributed to anthropogenic and natural disturbances in the Amazon Arc of Deforestation
Authors: Csillik Ovidiu , Keller Michael , Longo Marcos , Ferraz Antonio , Rangel Pinagé Ekena , Görgens Eric Bastos , Ometto Jean P. , Silgueiro Vinicius , Brown David , Duffy Paul , Cushman K. C. , Saatchi Sassan
Published: August 2024

The Amazon forest contains globally important carbon stocks, but in recent years, atmospheric measurements suggest that it has been releasing more carbon than it has absorbed because of deforestation and forest degradation. Accurately attributing the sources of carbon loss to forest degradation and natural disturbances remains a challenge because of the difficulty of classifying disturbances and simultaneously estimating carbon changes. We used a unique, randomized, repeated, very high-resolution airborne laser scanning survey to provide a direct, detailed, and high-resolution partitioning of aboveground carbon gains and losses in the Brazilian Arc of Deforestation. Our analysis revealed that disturbances directly attributed to human activity impacted 4.2% of the survey area while windthrows and other disturbances affected 2.7% and 14.7%, respectively. Extrapolating the lidar-based statistics to the study area (544,300 km
2
), we found that 24.1, 24.2, and 14.5 Tg C y
−1
were lost through clearing, fires, and logging, respectively. The losses due to large windthrows (21.5 Tg C y
−1
) and other disturbances (50.3 Tg C y
−1
) were partially counterbalanced by forest growth (44.1 Tg C y
−1
). Our high-resolution estimates demonstrated a greater loss of carbon through forest degradation than through deforestation and a net loss of carbon of 90.5 ± 16.6 Tg C y
−1
for the study region attributable to both anthropogenic and natural processes. This study highlights the role of forest degradation in the carbon balance for this critical region in the Earth system.
Prostate cancer–induced endothelial-cell-to-osteoblast transition drives immunosuppression in the bone–tumor microenvironment through Wnt pathway–induced M2 macrophage polarization
Authors: Yu Guoyu , Corn Paul G. , Mak Celia Sze Ling , Liang Xin , Zhang Miao , Troncoso Patricia , Song Jian H. , Lin Song-Chang , Song Xingzhi , Liu Jingjing , Zhang Jianhua , Logothetis Christopher J. , Melancon Marites P. , Panaretakis Theocharis , Wang Guocan , Lin Sue-Hwa
Published: August 2024

Immune checkpoint therapy has limited efficacy for patients with bone-metastatic castration-resistant prostate cancer (bmCRPC). To improve immunotherapy for bmCRPC, we aimed to identify the mechanism of bmCRPC-induced changes in the immune microenvironment. Among bmCRPC patients, higher levels of a 32-gene M2-like macrophage signature in bone metastasis samples correlated with shorter overall survival. Immunohistochemistry showed that CD206-positive (CD206
+
) macrophages were enriched in bmCRPC bone biopsy specimens compared with primary tumors or lymph node metastases. In preclinical osteogenic prostate cancer (Pca) xenograft models, CD206
+
macrophages were recruited to areas with tumor-induced bone. RNA sequencing (RNAseq) analysis showed higher expression of an M2-like gene signature, with activated canonical and noncanonical Wnt pathways, in tumor-associated macrophages isolated from osteogenic tumors (bone-TAMs) than in TAMs isolated from nonosteogenic tumors (ctrl-TAMs). Mechanistic studies showed that endothelial cells (ECs) that had undergone EC-to-osteoblast (EC-to-OSB) transition, the precursors of tumor-induced OSBs, produced paracrine factors, including Wnts, CXCL14, and lysyl oxidase, which induced M2 polarization and recruited M2-like TAMs to the bone–tumor microenvironment (bone-TME). Bone-TAMs suppressed CD8
+
T cells’ proliferation and cytolytic activity, and these effects were partially reversed by treating bone-TAMs with Wnt inhibitors. Genetic or pharmacological inhibition of Pca–induced EC-to-OSB transition reduced the levels of M2-like macrophages in osteogenic tumors. Our study demonstrates that Pca–induced EC-to-OSB transition drives immunosuppression in the bone-TME, suggesting that therapies that reduce Pca–induced bone formation may improve immunotherapeutic outcomes for bmCRPC.
Superoxide radicals mediated by high-spin Fe catalysis for organic wastewater treatment
Authors: Li Yanxiao , Zhang Dongpeng , Wang Pengfei , Qu Jinyong , Zhan Sihui
Published: August 2024

Water resources are indispensable basic resources and important environmental carriers; the presence of organic contaminants in wastewater poses considerable risks to the health of both humans and ecosystems. Although the Fenton-like reactions using H
2
O
2
as the oxidant to destroy organic pollutants are attractive, there are still challenges in improving reaction activity under neutral or even alkaline conditions. Herein, we designed a H
2
O
2
activation pathway with O
2
•−
as the main active species and elucidated that the spin interaction between Fe sites and coordinated O atoms effectively promotes the generation of the key intermediate Fe–*OOH. Furthermore, we successfully captured and analyzed the Fe–*OOH intermediate by in situ Raman spectroscopy. When applying FBOB to a continuous-flow reactor, CIP removal efficiency remained at around 90% within 600 min of continuous operation, achieving excellent efficiency, stability, and pH tolerance in removing pollutants.
Development and initial validation of a yes/no vocabulary test for North Sámi
Authors: Gyllstad Henrik , Kupisch Tanja , Lloyd-Smith Anika
Published: August 2024

This paper accounts for the development and initial validation of a yes/no vocabulary test of North Sámi called
North Sámi Vocabulary Test (NSVT). North Sámi (NS) is an Indigenous language spoken in northern Scandinavia. Being an endangered
language, NS is in need of revitalisation efforts. One contribution is the provision of proficiency assessment tools. We
administered a 75-item NSVT version (50 real verbs and 25 pseudoverbs) to users of North Sámi in Sweden and Norway
(N = 289). Evidence of high item- and person-based reliability and separation indices were observed, as well
as support for a number of validity facets. High correlations existed between NSVT scores and self-reported and rated spoken
proficiency. The NSVT provides quick and reliable assessment of vocabulary knowledge and an indication of overall language
proficiency in North Sámi.
Hate, prejudice and conspiracy theories
Authors: Beringuy Adriano , Alvim Leandro Guimarães Marques
Published: August 2024

The Internet serves as a dynamic and expansive space where numerous groups seek to exchange and disseminate their views. Some of those groups aim to promote hateful ideologies, bigotry, conspiracy theories while externalizing their anger. To achieve this, a spectrum of online platforms is utilized, ranging from mainstream social networks to underground forums. Notably, imageboards stand out as fertile ground where these ideologies flourish, due to anonymity, community engagement, and a plethora of hateful content. This study endeavors to examine the prevalence of bigotry in these spaces within the Brazilian context. Natural language processing algorithms provide the possibility to explore discursive features of massive text sets, extracting latent information and patterns in a relatively simple and automated way. This study shows how prejudice forms the basis of the different discourses found in Brazilian imageboards. Notably, these discourses not only echo historically rooted hateful ideologies but also assimilate conspiratorial perspectives and instances of bigotry emanating from non-Brazilian imageboards.
How quotation marks do mockery in online politicized discourse
Authors: Robles Jessica S. , Xiong Bingjuan
Published: August 2024

This article analyzes online comments responding to viral sociopolitical events in different languages, across
different social media platforms. We use discourse analytic methods to inspect how quotation marks are systematically deployed to
intensify denigrations of opposing political identities and positions in the context of political disagreements. We show how
quotation marks are used in situated online interactions to convey a skeptical, derisive stance toward quoted content while
positioning one’s reasonable perspective against an unreasonable, illegitimate other. This online discursive practice provides
insights into how ordinary politics are engaged (or rather, not seriously engaged) when people participate in
mockery in disputative online discourse.
X-ray circular dichroism measured by cross-polarization x-ray transient grating
Authors: Rouxel Jérémy R , Mincigrucci Riccardo , Fainozzi Danny , Masciovecchio Claudio
Published: August 2024

Measuring natural circular dichroism in the x-ray regime to extract stereochemical information from chiral molecules in solution remains a challenge. This is primarily due to technical limitations of the existing synchrotron sources, which hinder access to measurements of local chirality by exploiting core hole electronic transitions. In response to this challenge, we propose an alternative approach: utilizing XFEL-based cross-polarization x-ray transient grating (XTG). This method provides an indirect means to measure x-ray circular dichroism (XCD). Notably, our findings reveal that the signal emerges only once the excited cores have undergone dephasing through relaxation. XTG is now routinely measured in the XUV regime and has recently been made available for hard x-rays. Free electron lasers now offer polarization controls, and XTG can be extended to various polarization states for the two pump beams, making XCD measured by XTG feasible with the current state-of-the-art technology.
Anisotropy-driven magnetic phase transitions in SU(4)-symmetric Fermi gas in three-dimensional optical lattices
Authors: Unukovych Vladyslav , Sotnikov Andrii
Published: August 2024

We study an SU(4)-symmetric ultracold fermionic mixture in a cubic optical lattice with a variable tunneling amplitude along one particular crystallographic axis in the crossover region from the two- to three-dimensional spatial geometry. To theoretically analyze the emerging magnetic phases and physical observables, we describe the system within the framework of the Fermi–Hubbard model and apply dynamical mean-field theory. We show that in two limiting cases of anisotropy, there are two phases with different antiferromagnetic orderings in the zero temperature limit and we determine a region of their coexistence. We also study the stability regions of different magnetically ordered states and density profiles of the gas in the harmonic optical trap.
Ionization by radiative energy transport vs. impact ionization in energetic atomic collisions
Authors: Jacob A , Müller C , Voitkiv A B
Published: August 2024

We explore a mechanism for ionization in high-velocity (but not yet relativistic) collisions of light atomic particles, one of which being initially in an excited internal state. This mechanism is driven by the generalized Breit interaction and proceeds via radiative energy transport between the colliding particles which has an extremely long range. A comparison of this mechanism with those which are ‘standard’ for high-velocity collisions shows that it can play a noticeable role in collisions with excited target atoms.
Simulation of deflection and photon emission of ultra-relativistic electrons and positrons in a quasi-mosaic bent silicon crystal
Authors: E Ibañez-Almaguer Paulo , Rojas-Lorenzo Germán , Márquez-Mijares Maykel , Rubayo-Soneira Jesús , B Sushko Gennady , V Korol Andrei , V Solov’yov Andrey
Published: August 2024

A comprehensive numerical investigation has been conducted on the angular distribution and spectrum of radiation emitted by 855 MeV electron and positron beams while traversing a ‘quasi-mosaic’ bent silicon (111) crystal. This interaction of charged particles with a bent crystal gives rise to various phenomena such as channeling, dechanneling, volume reflection, and volume capture. The crystal’s geometry, emittance of the collimated particle beams, as well as their alignment with respect to the crystal, have been taken into account as they are essential for an accurate quantitative description of the processes. The simulations have been performed using a specialized relativistic molecular dynamics module implemented in the MBN Explorer package. The angular distribution of the particles after traversing the crystal has been calculated for beams of different emittances as well as for different anticlastic curvatures of the bent crystals. For the electron beam, the angular distributions of the deflected particles and the spectrum of radiation obtained in the simulations are compared with the experimental data collected at the Mainz Microtron facility. For the positron beam such calculations have been performed for the first time. We predict significant differences in the angular distributions and the radiation spectra for positrons versus electrons.
Magnetic field enhanced laser absorption on a metallic surface incorporated with shape-dependent nanostructures
Authors: Simon Moses , Chauhan Prashant
Published: August 2024

This communication proposes an analytical model to investigate the nanoparticle-based nonlinear absorption phenomenon associated with an obliquely incident p-polarized laser beam on a metallic surface. In this scheme, the surface is ingrained with noble-metal spherical nanoparticles and cylindrical nanoparticles in the presence of an external static magnetic field. The absorption of laser energy in the presence of nanoparticles (NPs) is attributed to surface plasmon resonance and enhanced magnetic-field effects. The absorption phenomenon is significantly enhanced by the incorporation of nanostructures and a magnetic field. The ellipticity characterizing parameter, which significantly influences the resonant frequency of different nanometric structures, has also been analysed and discussed. The effects of varying the magnetic field intensity, incident angle, size, and spacing of the NP were examined to determine their influence on the anomalous absorption of the laser. Furthermore, a direct dependency was found between the absorption coefficient and transmission coefficient of the incident laser, as well as the dimensions of the NPs. Several applications have direct relevance to this study, including biosensors such as DNA sensors and immunosensors, photothermal therapy, photoacoustic imaging, optoelectronic devices, solar cells, and surface-enhanced Raman spectroscopy.
Vibronics of multi-material nanopillared membranes and impact on the thermal conductivity
Authors: Yang Lina , Hussein Mahmoud I
Published: August 2024

Atomic motion in nanopillars standing on the surface of a silicon membrane generates vibrons, which are wavenumber-independent phonons that act as local resonances. These vibrons couple with the vast majority of the phonon population, including heat-carrying phonons, traveling along the base membrane causing a reduction in the in-plane lattice thermal conductivity. In this work, we examine isolated silicon and gallium nitride nanopillars and for each compare the vibrons density of states (DOS) to those of phonons in an isolated version of the silicon membrane. We show that while the conformity of the phonon-vibron DOS distribution between the two components across the full spectrum is a key factor in reducing the thermal conductivity of the assembled nanostructure, the presence of an intense vibron population at more dominant low frequencies plays a competing role. We report predictions from molecular dynamics simulations showing lower thermal conductivities for a silicon membrane with gallium-nitride nanopillars compared to a silicon membrane with silicon nanopillars.
Design and experiment of a lightweight cloud particle imager
Authors: Cai Lele , Liu Lei , Zeng Qingwei , Wang Peng
Published: August 2024

Accurate in-situ measurement of cloud microphysical parameters such as particle diameter, number concentration and droplet spectrum distribution are of great significance in cloud physics, climate change, numerical weather forecasting and weather modification. This work describes the design and characterization of a newly developed in situ measurement instrument for cloud and fog named lightweight cloud particle imager (LCPI). The basic measurement principle of LCPI is based on scattering light imaging of particles in a dark field. A ring LED lighting source was designed to improve the image quality. Field measurements were carried out at a high-altitude research station on Lushan Mountain. The measured size distributions showed good agreement with parallel measurements of a cloud droplet spectrometer (fog monitor-120). The field data also showed that LCPI was able to measure the size distribution of cloud droplets from 5 to 300 μm with a high spatial resolution. In addition, another observation experiment carried out in the Tuli River weather station showed that LCPI also had the ability to acquire clear images of ice crystal particles larger than 10 μm. Thus, LCPI provides an opportunity to simultaneously quantify the microphysical structure of different cloud types.
Research on traffic sign detection algorithm based on improved SSD in complex environments
Authors: Zhang Hong , Zhang Wei , Wang Wanqi , Li Xinlong , Zhang Anyu
Published: August 2024

In complex traffic sign environments, detection challenges include uneven size distribution, insufficient valid information, and difficulties in identifying targets under resource constraints, leading to missed and false detections. This study proposes an enhanced lightweight traffic sign detection algorithm based on single shot multibox detector (SSD). By replacing the original backbone network with MobileNetV2, the model is streamlined to have fewer parameters, which improves generalization in complex environments. This modification significantly boosts the recall rate, achieving a better balance between precision and recall. By introducing the feature pyramid network combined with the convolutional block attention module attention mechanism, the detailed and semantic information between deep and shallow layers is fully integrated, reducing the loss of feature information, thus enhancing the strengthening of key information of traffic signs and the adaptability to different scales of traffic signs. Finally, by integrating the cross-attention mechanism, the algorithm’s anti-interference ability in complex environments is improved, and the positioning accuracy of traffic signs is enhanced by capturing the dependency between different positions. Through ablation experiments and comparative experiments on a public traffic sign dataset, our improved SSD algorithm achieved an mean average precision (mAP) of 89.97%. Compared with the original algorithm, the mAP increased by 12.41%, the recall rate increased by 18.38%, and the sum of precision and recall F1 increased by 14.6%. These improvements significantly enhance the performance of traffic sign detection in complex environments, thereby meeting the performance requirements of traffic sign detection.
A quantum artificial bee colony algorithm based on quantum walk for the 0–1 knapsack problem
Authors: Huang Yuwei , Zhou Tianai , Xu Gang , Wang Lefeng , Lu Yong , Ma Li , Zhang Kejia , Chen Xiu-bo
Published: August 2024

Based on the characteristics of the quantum mechanism, a novel quantum walk artificial bee colony algorithm is proposed to promote performance. Firstly, the discrete quantum walk is an approach taken to search for new food sources in the updated phase for employed bees and onlooker bees, which can enhance the probability of the target solution to extend the exploration capability. Secondly, the food source selection policy of the onlooker bees changes, from roulette selection to tournament selection, to boost exploitation and convergence speed. Finally, the novel algorithm is brought forward, along with the approach to analyze 0–1 knapsack problems. The experimental results prove that our algorithm can overcome the premature phenomenon and perform better in the areas of search capability, convergence speed, and stability performance. The performance is superior to that of the conventional artificial bee colony algorithm, as well as the genetic algorithm, in a set of 0–1 knapsack problems.
Superconductivity investigation of (Bi, Pb)-2223 added with different nanoferrites and their composites
Authors: Najem Ahmad , Habanjar K , Awad R , Anas M , Matar M
Published: August 2024

In this study, the impact of different types of nanoferrites additions of Zn0.5Ni0.5Fe2O4 and Ba0.4Sr0.4Ca0.2Fe12O19 nanoparticles and their nanocomposite of (Zn0.5Ni0.5Fe2O4)0.5 (Ba0.4Sr0.4Ca0.2Fe12O19)0.5 on the structural and normal state resistivity of Bi1.6Pb0.4Sr2Ca2Cu3O10, ((Bi,Pb)-2223) superconducting phase were systematically investigated. The samples were synthesised using high purity oxide powders via a solid-state reaction approach. Based on the Rietveld analysis of x-ray diffraction (XRD) data, the tetragonal structure of (Bi,Pb)-2223 was established to be the predominant phase for all composite samples of the three nano-additions’ contents. However, a little change to the lattice parameters (

a

and

c

) was obtained. Furthermore, the small amounts (0.04 wt%) of Ba0.4Sr0.4Ca0.2Fe12O19 and (Zn0.5Ni0.5Fe2O4)0.5(Ba0.4Sr0.4Ca0.2Fe12O19)0.5 improved the development of the (Bi,Pb)-2223 phase. The volume fraction of the (Bi,Pb)-2223 phase increased from 86.47% to 88.73% and 88.69%, respectively. Then, it declined to 74.25% and 71.48% upon rising x to 0.40 wt%, respectively, as well as for Zn0.5Ni0.5Fe2O4 nanoparticles up to 0.40 wt%. SEM images verify the host superconducting matrix’s granular structure for all three nanoadditions up to 0.40 wt%. The existence of three nano additions in the host superconductor matrix is verified by employing energy dispersive x-ray (EDX) and x-ray photoelectron spectroscopy (XPS) analysis. The measurements for the resistivity dependency of temperature presented that, as compared to the pure sample (Tc = 108.67 K), the nano-(Zn0.5Ni0.5Fe2O4)
x
added in the (Bi,Pb)-2223 phase exhibits more negative impact than it is with the other two additions. In contrast, the nano-(Ba0.4Sr0.4Ca0.2Fe12O19)
x
has the highest value of Tc with a value of 110.95 K at x = 0.04 wt%. Furthermore, the superconducting transition width (∆Tc) improved for all composite samples except for the sample at x = 0.04 wt%, for Ba0.4Sr0.4Ca0.2Fe12O19 and (Zn0.5Ni0.5Fe2O4)0.5 (Ba0.4Sr0.4 Ca0.2Fe12O19)0.5 which showed the sharpest transition width. This suggests that their addition is anticipated to act as artificial pinning centers and strengthen the coupling between the grains in the (Bi,Pb)-2223 ceramic.
Weak lensing constraints on dark matter-baryon interactions with 𝖭-body simulations and machine learning
Authors: Zhang Chi , Zu Lei , Chen Hou-Zun , Tsai Yue-Lin Sming , Fan Yi-Zhong
Published: August 2024

We investigate the elastic scattering cross section between dark matter and protons using the DES Year 3 weak lensing data.
This scattering induces a dark acoustic oscillation structure in the matter power spectra.
To address non-linear effects at low redshift, we utilize principal component analysis alongside a limited set of N-body simulations,
improving the reliability of our matter power spectrum prediction.
We further perform a robust Markov Chain Monte Carlo analysis
to derive the upper bounds on the DM-proton elastic scattering cross-section,
assuming different velocity dependencies.
Our results, presented as the first Frequentist upper limits, are compared with the ones obtained by Bayesian approach.
Compared with the upper limits derived from the Planck cosmic microwave background data,
our findings from DES Year 3 data exhibit improvements of up to a factor of five.
In addition, we forecast the future sensitivities of the China Space Station Telescope,
the upcoming capabilities of this telescope could improve the current limits by approximately one order of magnitude.
Displacement versus velocity memory effects from a gravitational plane wave
Authors: Achour Jibril Ben , Uzan Jean-Philippe
Published: August 2024

This article demonstrates that additionally to the well-known velocity memory effect, a vacuum gravitational plane wave can also induce a displacement memory on a couple of test particles. A complete classification of the conditions under which a velocity or a displacement memory effect occur is established. These conditions depend both the initial conditions of the relative motion and on the wave profile. The two cases where the wave admits a pulse or a step profile are treated. Our analytical expressions are then compared to numerical integrations to exhibit either a velocity or a displacement memory, in the case of these two families of profiles. Additionally to this classification, the existence of a new symmetry of polarized vacuum gravitational plane wave under Möbius reparametrization of the null time is demonstrated. Finally, we discuss the resolution of the geodesic deviation equation by means of the underlying symmetries of vacuum gravitational plane wave.
Riemann–Hilbert approach and soliton solutions for the Lakshmanan–Porsezian–Daniel equation with nonzero boundary conditions
Authors: Wang Yilin , Li Biao
Published: August 2024

We construct the Riemann–Hilbert problem of the Lakshmanan–Porsezian–Daniel equation with nonzero boundary conditions, and use the Laurent expansion and Taylor series expansion to obtain the exact formulas of the soliton solutions in the case of a higher-order pole and multiple higher-order poles. The dynamic behaviors of a simple pole, a second-order pole and a simple pole plus a second-order pole are demonstrated.
Anomaly detection for atomic clocks using unsupervised machine learning algorithms
Authors: Chen Edwin , Charbonneau André , Gertsvolf Marina , Wang Yunli
Published: August 2024

Atomic clocks are the most accurate timekeeping instruments in the world and play a crucial role in numerous applications, notably in satellite navigation. Nonetheless, the accuracy of these clock signals is subject to anomalies, highlighting the importance of anomaly characterization and detection. In our study, we identify three types of anomalies in the phase data of atomic clocks—outliers, phase jumps and inflection points, and also frequency jumps in the frequency data, which corresponds to the inflection points. The novelty of our work lies in the application of machine learning methods for atomic clock anomaly detection (AD), as opposed to traditional algorithms. We introduce a variety of unsupervised AD and change point detection (CPD) algorithms from the realms of statistics and machine learning, propose a customized thresholding function for AD, and evaluate AD and CPD algorithms on both synthetic and real-world atomic clock data. Our experiments reveal that the subsequence local outlier factor algorithm achieves excellent performance in detecting outliers and phase jumps, but struggles with inflection points. Crucially, we found that the application of a CPD algorithm specifically for detecting the frequency jumps in frequency data substantially improves performance. Our study adopts unsupervised machine learning methods for AD provides robust detection strategies, thereby contributing an expanded understanding of the use of machine learning for clock data monitoring.
Enhancing electrochemical performance of lithium-ion batteries with diverse nanomaterials
Authors: Cui Zijun
Published: August 2024

Although lithium-ion batteries (LIBs) can be widely used, there are some challenges such as safety risks, lower energy density compared to fossil fuels, high cost, long charging times and limited range in electric vehicles. Nanomaterials, with their unique properties and surface effects, can effectively address these challenges and improve the electrochemical performance of LIBs. This research introduces six types of nanomaterials used in LIBs, including TiS3 nanoflakes, ZnMn2O4 nanobundles, ZrO2 surface-modified cathode material, nitrogen-doped carbon fibers with tin (Sn) nanoparticles, carbon nanosheets, and nanostructured bismuth-carbon composites. These recent advancements in nanomaterials can improve electrochemical performance of LIBs, such as specific capacity, cycling ability and stability. The study offers some innovative insights and approaches in using nanomaterials and synthesizing them for emerging battery technologies. In addition, this research is wished to provide a fresh perspective and methodology that can advance the performance and design of LIBs, and provide a new design approach for nanomaterials.
Comparative study of direct solid-gas carbonation and direct aqueous carbonation for carbon capture and storage
Authors: Wang Jack
Published: August 2024

Carbon dioxide (CO2) is a significant contributor to global warming and environmental issues, necessitating the development of practical storage solutions. As an alternative to CO2 storage in subsurface formations, mineral carbonation, which offers long-term CO2 storage and advantages like thermodynamics and energy economy, is gaining popularity. Also, the possible repurposing of carbonated solid waste in the building and construction industry contributes to the reduction of CO2. However, large-scale implementation of natural mineral carbonation remains a challenge. This study investigates the comparative advantages and disadvantages of direct solid-gas and direct aqueous carbonation, two carbon capture and storage (CCS) methods for combating atmospheric CO2 emissions. The research focuses on reaction kinetics, capture efficiency, recovery efficiency, leakage security, and cost-effectiveness. Both methods have the potential to capture CO2 efficiently, but they differ in their effectiveness and feasibility. Direct solid-gas carbonation exhibits higher reaction rates and capture efficiency, while direct aqueous carbonation has lower energy requirements and is easier to implement at ambient temperature and pressure. Further research is essential to fully understand the comparative merits and drawbacks of direct solid-gas and aqueous carbonation and devise strategies to minimize their environmental impact. Furthermore, to ensure economic feasibility, future research should focus on lowering CO2 sequestration costs, increasing the scale of captured CO2 usage in industrial processes, and developing a circular economy by transforming captured CO2 into valuable metal carbonates.
How new nanomaterials can improve the performance of lithium batteries
Authors: Wu Zhiyi
Published: August 2024

In recent years, lithium batteries have become energy storage methods in many fields for their advantages of high energy density, and many fields such as civil electric vehicles, electronic products, and aerospace rely on lithium batteries. At present, the performance demand for lithium batteries in electric vehicles is increasing, and finding ways to improve the performance of lithium batteries has become a top priority. Since silicon has the highest theoretical specific capacity, carbon nanotube technology is relatively mature, and the research and development prospects of new negative electrode materials for nano-batteries are broad. This paper analyzes the different influences of nano-silicon-based materials, carbon nanotubes modified by new materials and new negative nano-lithium materials on lithium batteries from nanomaterials. And summarize their respective roles to help readers further understand the application of nanomaterials in lithium batteries. It is designed to help readers further understand the application of nanomaterials in lithium batteries.
Study on the performance of lithium iron phosphate battery based on its application in transportation field
Authors: Lu Yingjie
Published: August 2024

The technology of lithium iron phosphate batteries is increasingly becoming developed and stable as a result of the new energy sector’s quick and steady development. With its unique performance advantages and characteristics, lithium iron phosphate battery occupies a large market share and has a wide range of application scenarios. This paper analyzes the specific application scenarios of lithium iron phosphate batteries in the field of transportation and derives the specific performance advantages of lithium iron phosphate batteries. Lithium iron phosphate battery has high energy density, high safety, high cycle life, high-temperature adaptability and other performance advantages. In addition, Lithium iron phosphate batteries are also inexpensive and kind to the environment. Therefore, lithium iron phosphate batteries can better meet the demand for battery applications in the field of transportation. At the same time, these advantages also make the lithium iron phosphate battery in other areas such as communication energy storage and peak energy storage have a high application value. By specifically studying the advantages of lithium iron phosphate, I believe that we can further promote the market application of lithium iron phosphate batteries and provide a method of reference for other batteries.
The effects of herbs on the runoff and sediment-producing mechanism in Jinyang Ancient City
Authors: Shang Ruihua , Gu Ruifang , Han Pengju , Liu Weiwei
Published: August 2024

To study the effects of herbs on the runoff and sediment producing mechanism of Jinyang Ancient City, this study used the method of field artificial rainfall experiments to compare the earthen sites slope effects on the runoff producing, sediment producing, and soil infiltration of the plant slope surface in different periods. The conclusions are as follows. The phenomenon of petrichor was related to the withered herb coverage on the surface of the slope. The fluctuation amplitude of the soil volume moisture content was related to its distance to the surface. The runoff producing effects of different slopes were in descending order of Bare Soil slope, Fresh Herbs slope, and Withered Herbs slope. The sediment producing effects were in descending order of Bare Soil slope, Withered Herbs slope, and Fresh Herbs slope. The sediment yield intensity was positively correlated with runoff intensity, but its variation peak lagged slightly behind the latter. The runoff intensity and sediment yield was influenced by the dual effects of rainfall intensity and rainfall time, and sometimes the impact of rainfall time was higher than that of rainfall intensity. A research assistance in can be hopefully provided in this study on protecting earthen sites from rainfall erosion through plant covering.
Beyond earth: Evaluating SiC and GaN as next-generation semiconductors for Venus exploration
Authors: Wang Junbo
Published: August 2024

This paper evaluates Silicon Carbide (SiC) and Gallium Nitride (GaN) as potential wide-bandgap semiconductor materials for Venus’ surface exploration. Both materials possess properties advantageous for withstanding Venus’ extreme conditions. Through an in-depth comparison, the study examines stability, energy efficiency, and integration levels of both materials. Although GaN showcases superior electron mobility and potential for high energy efficiency, it confronts challenges in large-scale circuit integration due to its limited wafer size and intricacies in device structure design. Conversely, SiC-based processors have demonstrated operability at high temperatures, with performance comparable to computers used in previous space missions. While neither material currently achieves the processing prowess of past space exploration computers, the study recommends SiC for Venus exploration due to its demonstrated capabilities and higher potential for integration. The paper concludes that optimized SiC processors hold promise for future Venusian surface missions.
A review of SLAM techniques and applications in unmanned aerial vehicles
Authors: Fang Ruinan , He Peidong , Gao Yangyang
Published: August 2024

Simultaneous Localisation and Mapping (SLAM) is a foundational idea in the field of robotics. It involves the processing of sensor signals and the optimisation of pose-graphs. SLAM has found several applications in various domains, including but not limited to courier services, agriculture, environmental monitoring, and military operations, particularly with the use of Unmanned Aerial Vehicles (UAVs). There exist several applications. This work aims to provide a comprehensive analysis of three Simultaneous Localization and Mapping (SLAM) algorithms, namely CNN-SLAM, Linearized Kalman Filter (LKF), and Extended Kalman Filter (EKF). Additionally, it will explore the utilisation of SLAM algorithms in Unmanned Aerial Vehicles (UAVs) by examining its use in precision agriculture, geological surveys, and Emergency Scenarios. This section will outline certain issues that SLAM algorithms may encounter in relation to wide area applications, real-time processing and efficiency, robustness, and dynamic objects within the environment. Ultimately, this study will undertake a comparative analysis of the merits and drawbacks associated with the three algorithms, while also putting up potential remedies for the aforementioned issues.
Developments of heavy metal removal methods during the latest decade based on Citespace analysis
Authors: Zhai Yuhao
Published: August 2024

Heavy metal pollution has been one of the most important issues all around the world. Millions of people caught serious diseases because of such pollutions. Thus, many research focused on heavy metal removal, and several reviews had been made. However, most of them pay attention to a certain field. This research used mega data to offer a general view of the development of heavy metal removal in the past decade. With the help of software of Citespace, the clustering chart, timeline and landscape of certain topics are made from the Web of Science Core Collection between 2013 and 2023. From the clustering charts, we discovered the most popular topics in recent years, which are “Biosorption” “Adsorption” “Microalgae” “Electrocoagulation” “Biochar” and “Water treatment”. Also, we analyzed clusters one by one, and give a brief introduction of some of the most popular keywords of each topic. From the timelines, developments of each topic are given. We can conclude that “Biosorption” and “Biochar” are gaining more attention, while “Adsorption” is less and less popular. “Microalgae”, “Electrocoagulation” and “Water treatment” have stable popularity. This article is aimed to introduce a new method of analyzing data and up-to-date information in heavy metal removal to readers.
Experimental study on classification and identification method for fault signals of mining steel wire ropes
Authors: Zhou Zeyang , Zhang Mingzhu , Tian Jie , Huang Jingwen
Published: August 2024

In the coal mining production process, wire ropes play a crucial role as the main tool for transporting personnel and materials in the entire coal mine hoisting system, and their fault identification is particularly critical. To address the problem of fault identification of mining wire ropes, a recognition model design combining K Singular Value Decomposition (SVD) with Genetic Algorithm (GA) optimized Support Vector Machine (SVM) is proposed. Firstly, K Singular Value Decomposition is used to denoise the collected wire rope damage signals. Feature vectors are extracted from the denoised and reconstructed signals to form the feature set of wire rope damage. Genetic Algorithm is utilized to select the optimal parameters of the Support Vector Machine and train it to obtain the optimal identification model for wire rope damage. Simulation and experimental results show that compared with wavelet thresholding and Empirical Mode Decomposition (EMD) denoising algorithms, the method using K Singular Value Decomposition for denoising achieves a signal-to-noise ratio of 25.166dB and a root mean square error of 0.805. Compared with Particle Swarm Optimization (PSO) optimized Support Vector Machine identification model, the identification rate of the Support Vector Machine identification model optimized by Genetic Algorithm is higher, reaching 96.67%. This method realizes accurate identification of different damage signals of wire ropes, which is conducive to ensuring the safe and efficient production of coal mines.
Review on low power design of digital integrated circuits
Authors: Hu Weijun
Published: August 2024

With the rapid development of science and technology, integrated circuit (IC) plays an increasingly important role in our daily life. Moreover, due to the increasing reduction of chip process size, the IC had greatly improved on its integration and performance. However, because of the improvement of the system complexity and the widely applied to various mobile devices, power consumption becomes an important limitation of the development in chip design. Power consumption not only affects the chip package type and cost, but also causes the increasing of chip temperature, which will directly affect the reliability of chips. On the other hand, high power consumption will also harm the stability of chips. Low power design are becoming more and more imminent, so low-power design are becoming a tendency of designing digital integrated circuits. This paper firstly introduces the importance of nowadays IC research, some background principles and research process of integrated circuits, then analyses the current challenges of designing low-power ICs and also research the power consumption of digital integrated circuits, later explores and analyses the low-power design methods in two different ways. And finally summarize the research status on low-power design circuits with some relevant personal views and the vision to the future are also put forward.
3D packaging and Moore’s Law
Authors: Yuan Yifan
Published: August 2024

This paper describes how the semiconductor industry has seen steady improvements in key metrics such as performance, power consumption, and area, but as the semiconductor industry shrinks in device size and the technical challenges of ever-increasing performance demands, it is critical to improve chip performance for maximizing the operating frequency of individual ICs and reducing their power consumption. But when talking about improving chip performance, it is important not to focus solely on the individual integrated circuit (IC), but to evaluate it as part of the overall system. For example, as microprocessor frequency increases, so does the demand for main memory data. However, if the connections between the chips that transfer data to the processor do not keep pace with the increase in performance, these connections can become a bottleneck in the performance of the entire system. Instead, this paper describes a typical architecture for semiconductor 3D integration, highlights the technology choices for 3D integration implementation, and analyzes and explains the design challenges it presents. After outlining the above, this paper also analyzes the applications and achievements of 3D integration technology in recent years.
Direct position determination algorithm based on wideband array signal model in external illuminator system
Authors: Lin Guorui , Jiang Yuan , Hu Kejia , Zhao Lei , He Shuming
Published: August 2024

Target location and tracking are among the most critical applications for external illuminator systems. Most traditional array signal direct position determination (DPD) techniques are based on narrowband signals. With the advancement of communication technology, various wideband signals are extensively utilized in communication systems, leading to the failure of some traditional DPD techniques. To address this issue, this article proposes a new DPD algorithm for wideband array signals. First, we suppress the direct wave (DW) interference in the received signal. Then, a cost function for the target coordinate is constructed based on the Maximum Likelihood (ML) criterion, and a phase matching matrix is created for the problem of unknown signal transmission time. Finally, the position estimation is obtained from the peak of the cost function. Simulation results demonstrate that the proposed algorithm outperforms traditional two-step localization methods based on the time difference of arrival of signals, particularly in cases where DW interference is present in the received signal.