bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluid shear stress induced-endothelial phenotypic transition contributes to cerebral ischemia–reperfusion injury and repair
Authors: Sun Denglian , Ma Jia , Du Lingyu , Liu Qiao , Yue Hongyan , Peng Chengxiu , Chen Hanxiao , Wang Guixue , Liu Xiaoheng , Shen Yang
Published: February 2024

Long-term ischemia leads to insufficient cerebral microvascular perfusion and dysfunction. Reperfusion restores physiological fluid shear stress (FSS) but leads to serious injury. The mechanism underlying FSS-induced endothelial injury in ischemia–reperfusion injury (IRI) remains poorly understood. In this study, a rat model of middle cerebral artery occlusion was constructed to explore cerebrovascular endothelial function and inflammation in vivo. Additionally, the rat brain microvascular endothelial cells (rBMECs) were exposed to a laminar FSS of 0.5 dyn/cm2 for 6 h and subsequently restored to physiological fluid shear stress level (2 dyn/cm2) for 2 and 12 h, respectively. We found that reperfusion induced endothelial-to-mesenchymal transition (EndMT) in endothelial cells, leading to serious blood–brain barrier dysfunction and endothelial inflammation, accompanied by the nuclear accumulation of Yes-associated protein (YAP). During the later stage of reperfusion, cerebral endothelium was restored to the endothelial phenotype with a distinct change in mesenchymal-to-endothelial transition (MEndT), while YAP was translocated and phosphorylated in the cytoplasm. Knockdown of YAP or inhibition of actin polymerization markedly impaired the EndMT in rBMECs. These findings suggest that ischemia–reperfusion increased intensity of FSS triggered an EndMT process and, thus, led to endothelial inflammation and tissue injury, whereas continuous FSS induced a time-dependent reversal MEndT event contributing to the endothelial repair. This study provides valuable insight for therapeutic strategies targeting IRI.
Evidence of strong wave turbulence and of Bolgiano temperature spectra in katabatic winds on steep slopes
Authors: Charrondière C. , Hopfinger E. J. , Brun C. , Cohard J.-M. , Sicart J.-E.
Published: February 2024

The katabatic winds on steep slopes investigated in the present study reveal a novel spectral behavior, observed in the outer part of the jet. At low wavenumbers, the one-dimensional (1D) velocity spectra show evidence of a kx−1 range for the three components of the velocity vector: Eu(kx),Ev(kx),Ew(kx)∝kx−1 [as well as for the 1D temperature spectrum Eθ(kx)∝kx−1]. This suggests the existence of strong wave turbulence. A necessary condition for strong wave turbulence to be manifest is that the flow direction wavenumber, kx, extends to much lower values than the slope normal one, kz. This is satisfied in the present field experiment where wave energy is injected at wavenumber kx=kN=(Na sin α)/uj¯, while kz∼1/Δz, with Na the ambient stratification, α the slope angle, uj¯ the maximum wind velocity, and Δz the shear layer thickness of the jet. In the inertial range, the velocity spectra exhibit a power law kx−5/3 over two decades, whereas the temperature-buoyancy spectra show evidence of a −7/5 slope in the buoyancy sub-range, followed by a −5/3 slope. The change in spectral slopes occurs at the Bolgiano scale LB that is close to the Dougherty–Ozmidov scale LOZ. The high Reynolds number based on the Taylor micro-scale, Reλ∼103, allows clear identification of the spectral laws.
Output breakdown characteristics of amorphous InGaZnO thin-film transistors at high gate voltage
Authors: Yang Huan , Huang Tengyan , Pan Wengao , Lu Lei , Zhang Shengdong
Published: February 2024

Output characteristics of top-gate amorphous InGaZnO thin-film transistors are investigated at high gate voltage. With the increasing drain voltage, an output breakdown crops up closely following a drastic uprush of drain current. Such dramatically elevated drain current derives from the self-heating (SH) effect-generated channel donors. Measured at different high gate voltages, the output breakdown occurs in either linear or saturation regime, respectively, corresponding to normally-on and normally-off transfer curve, while the SH-triggering powers are almost identical. The conductor-like channel originates from the SH-induced high donor population, while the disconnection between channel and drain is caused by a highly defective region near drain, where the hot-carrier damage is violently activated by the SH-induced high temperature and the high drain electric field in saturation regime.
Real-time in situ monitoring of dust particle growth in a low-pressure nanodusty plasma based on laser-induced photodetachment
Authors: Donders T. J. M. , Beckers J.
Published: February 2024

Particulate matter air pollution in the form of ultrafine dust is a growing global concern. In this Letter, we will use a nanodusty Ar/HMDSO plasma as a model system for a heavily contaminated gas and we present the development of a technique for real-time in situ measurements of the dust particle size. The method is based on laser-induced photodetachment of bound electrons from the surface of dust particles. These photo-released electrons are measured as an increase in the free electron density of the plasma using microwave cavity resonance spectroscopy. We show that instead of reconstructing the entire resonance profile, the temporal response of a single microwave frequency was enough to perform the measurements. More specifically, the decay timescale of the cavity response can be interpreted as the re-charging timescale of the dust particles. Then, using a stochastic model, this timescale can be modeled, which eventually retrieves the dust particle size. We found good agreement between the predicted dust particle size and the average dust particle size obtained from ex situ scanning electron microscopy measurements. This method allows for the real-time monitoring of the dust particle size and a controlled production of nanometer-scale dust particles, which gives opportunities both for fundamental dusty plasma physics and models, as well as for applications in monitoring ultrafine dust air pollution.
Perspectives on the robustness of the mechanical properties assessment of biocomposites
Authors: Chegdani Faissal , El Mansori Mohamed
Published: February 2024

Biocomposite materials made of natural plant fibers are becoming a viable alternative to the use of synthetic ones such as glass fibers, thanks to many economic, ecological, and technical benefits. However, their massive use in the industry requires optimal control of their mechanical performances, which constitutes a real scientific issue to be overcome. Indeed, biocomposites suffer from an important variability in their mechanical properties because of their multiscale structure, natural growth conditions, and various processing parameters, in addition to eventual chemical treatments. Biocomposites are also highly sensitive to the surrounding environment in terms of humidity and temperature because of the hydrophilic properties of natural plant fibers. In this context, this Perspective aims to provide a critical look at the influence of the main factors that affect the mechanical properties of biocomposites in order to suggest some possible research outlooks that could contribute to optimizing the control of these mechanical properties and expanding the use of biocomposites in industry.
Study on performance optimization of double screw-magnetic fluid combination seal
Authors: Li Zhenggui , Qing Jie , Shen Changrong , Ma Shangang , Wu Demin , Zhu Guoqing , Wang Ye , Yang Chao , He Xinyue , Su Jie
Published: February 2024

The magnetic fluid seal (MFS) is a new type of sealing method that offers the advantages of no leakage and low wear. Hence, it is widely used in rotary seals in coal, chemical, and electric power fields. However, at high speeds, the degradation and even failure of the sealing performance severely limits the application of MFS in engineering. Therefore, this study designed a combined sealing device comprising a double screw seal and MFS and optimized the pressure resistance of the screw seal using an orthogonal test in combination with the response surface optimization method. Thus, the pressure resistance could be raised to 3.1 times that before optimization. The effect of the sealing gap on the sealing pressure of the MFS was analyzed by numerical simulation, and an optimal sealing gap value of 0.2 mm was obtained. The results of the verification test showed that the performance of the combined seal was significantly better than that of MFS alone. When sealing liquids, the pressure resistance of the combined seal reached 3.3 times that of the MFS at 3000 rpm, which indicates the application potential of MFS in high-speed working conditions.
Investigation of hydrodynamic performance in a staggered multistage internal airlift loop reactor
Authors: Wang Weiwen , Pan Qingpeng , Shen Zongwang , Dong Yangshuo , Zhou Litong , Yu Zhixin , Chen Guanghui , Duan Jihai
Published: February 2024

The multistage internal airlift loop reactor (MIALR) has shown promising application prospects in gas–liquid–solid reaction systems. However, traditional MIALRs have a global circulation with strong interstage liquid-phase exchange. This paper proposes a staggered multistage internal airlift loop reactor (SMIALR) that incorporates special guide elements to create a staggered flow. Both experiments and computational fluid dynamics-population balance model simulations were conducted to investigate the hydrodynamic performances of MIALR and SMIALR. The results demonstrate that SMIALR exhibits a local circulation at each stage. Bubbles have a longer residence time in SMIALR, resulting in a 28.35%–55.54% increase in gas holdup and a 7.27%–13.69% increase in volumetric mass transfer coefficient. The gas–liquid mass transfer coefficient of SMIALR was improved by increasing the gas–liquid interfacial area. Additionally, the radial distribution of solids was found to be more uniform. This study offers insights for optimizing MIALR and provides a theoretical foundation for the design and scale-up of SMIALR.
Switchable diode effect in 2D van der Waals ferroelectric CuCrP2S6
Authors: Liu Ping , Li Yongde , Hou De , Zhu Hanpeng , Luo Hecheng , Zhou Shuang , Wei Lujun , Niu Wei , Sheng Zhigao , Mao Weiwei , Pu Yong
Published: February 2024

Two-dimensional (2D) ferroelectrics has emerged as a promising building block for nonvolatile memory devices. In this work, we demonstrate the out-of-plane ferroelectricity of 2D CuCrP2S6 (CCPS) at the room temperature and the switchable diode effect in 2D CCPS-based ferroelectric nanodevices. The spontaneous out-of-plane ferroelectric polarization switching and hysteresis loops are directly evidenced by the piezoresponse force microscopy. The intrinsic ferroelectricity originates from the non-centrosymmetric structure of 2D CCPS, which is confirmed by optical second-harmonic generation technique. A ferroelectric tunnel junction was built up by using 2D CCPS as a function layer. The observed diode-like forward rectification effect of CCPS diode is opposite to the direction of remnant polarization, which is attributed to the ferroelectric polarization modulation of Schottky barrier. Our work highlights the great potential of 2D CCPS in ultrathin ferroelectric memory device and motivates the development of multifunctional nanodevices.
Sources and mechanisms of flow loss and hydroacoustics in a pre-swirl stator pump-jet propulsor
Authors: Xu Chen , Du Zhongyuan , Mao Yijun , Zhao Yanjie , Zhao Wei , Li Mengjie
Published: February 2024

Accurately identifying sources of flow loss and hydroacoustics and clarifying the mechanism of their generation are crucial for directing the optimal design of efficient and quiet pump-jet propulsors (PJPs). In this paper, numerical simulations of steady and unsteady flow are performed for a PJP equipped with pre-swirl stationary vanes, based on which both sources of flow loss and hydroacoustics are investigated at multi-level granularity. Analyses of flow efficiency and entropy generation rate are performed to identify the sources of flow loss, and analyses of thrust fluctuation and wall pressure fluctuation are conduced to identify the sources of hydroacoustics. The results indicate that the pressure drag accounts for 76% of the total drag and is mainly contributed from the stator and the duct, but the flow efficiency of the rotor is much smaller than that of the stator and the sources of the flow loss are mainly located at three regions of the rotating blades: the leading edge, the tip, and the corner of the suction surface. The hydroacoustic sources are mainly located at the leading edge and the tip of the rotating blades due to stator–rotor and duct–rotor interactions, respectively, but the Taylor's frozen turbulence hypothesis is inappropriate to describe the wake evolution of the stationary vanes owing to the potential interaction caused by the blade rotation.
Surface diffusion on a palladium-based metallic glass
Authors: Wang Zijian , Perepezko John H.
Published: February 2024

The surface diffusion kinetics on a Pd77.5Cu6Si16.5 metallic glass is measured using a scratch smoothing method in the range of 107–57 K below the glass transition temperature. Within this temperature range, the surface diffusion coefficients are determined to vary between (8.66 ± 0.80) × 10−19 and (5.90 ± 0.60) × 10−18 m2 s−1. The corresponding activation energy is 0.93 ± 0.18 eV, which is about half the value for bulk diffusion. These measurements also corroborate the correlation between enhanced surface diffusion and liquid fragility in glasses.
Genomic ancestry and social dynamics of the last hunter-gatherers of Atlantic France
Authors: Simões Luciana G. , Peyroteo-Stjerna Rita , Marchand Grégor , Bernhardsson Carolina , Vialet Amélie , Chetty Darshan , Alaçamlı Erkin , Edlund Hanna , Bouquin Denis , Dina Christian , Garmond Nicolas , Günther Torsten , Jakobsson Mattias
Published: February 2024

Since the early Holocene, western and central Europe was inhabited by a genetically distinct group of Western Hunter-Gatherers (WHGs). This group was eventually replaced and assimilated by the incoming Neolithic farmers. The western Atlantic façade was home to some of the last Mesolithic sites of mainland Europe, represented by the iconic open-air sites at Hoedic and Téviec in southern Brittany, France. These sites are known for the unusually well-preserved and rich burials. Genomic studies of Mesolithic European hunter-gatherers have been limited to single or a few individuals per site and our understanding of the social dynamics of the last Mesolithic hunter-gatherers of Europe and their interactions with incoming farmers is limited. We sequenced and analyzed the complete genomes of 10 individuals from the Late Mesolithic sites of Hoedic, Téviec, and Champigny, in France, four of which sequenced to between 23- and 8-times genome coverage. The analysis of genomic, chronological and dietary data revealed that the Late Mesolithic populations in Brittany maintained distinct social units within a network of exchanging mates. This resulted in low intra-group biological relatedness that prevented consanguineous mating, despite the small population size of the Late Mesolithic groups. We found no genetic ancestry from Neolithic farmers in the analyzed hunter-gatherers, even though some of them may have coexisted with the first farming groups in neighboring regions. Hence, contrary to previous conclusions based on stable isotope data from the same sites, the Late Mesolithic forager community was limited in mate-exchange to neighboring hunter-gatherer groups, to the exclusion of Neolithic farmers.
Interplay between autophagy and CncC regulates dendrite pruning in
Drosophila
Authors: Tan Jue Yu Kelly , Chew Liang Yuh , Juhász Gábor , Yu Fengwei
Published: February 2024

Autophagy is essential for the turnover of damaged organelles and long-lived proteins. It is responsible for many biological processes such as maintaining brain functions and aging. Impaired autophagy is often linked to neurodevelopmental and neurodegenerative diseases in humans. However, the role of autophagy in neuronal pruning during development remains poorly understood. Here, we report that autophagy regulates dendrite-specific pruning of ddaC sensory neurons in parallel to local caspase activation. Impaired autophagy causes the formation of ubiquitinated protein aggregates in ddaC neurons, dependent on the autophagic receptor Ref(2)P. Furthermore, the metabolic regulator AMP-activated protein kinase and the insulin–target of rapamycin pathway act upstream to regulate autophagy during dendrite pruning. Importantly, autophagy is required to activate the transcription factor CncC (Cap “n” collar isoform C), thereby promoting dendrite pruning. Conversely, CncC also indirectly affects autophagic activity via proteasomal degradation, as impaired CncC results in the inhibition of autophagy through sequestration of Atg8a into ubiquitinated protein aggregates. Thus, this study demonstrates the important role of autophagy in activating CncC prior to dendrite pruning, and further reveals an interplay between autophagy and CncC in neuronal pruning.
Gentrification and access to housing in Mexico City during 2000 to 2022
Authors: Aguilar-Velázquez Daniel , Rivera Islas Iván , Romero Tecua Guillermo , Valenzuela-Aguilera Alfonso
Published: February 2024

We conducted a spatial and temporal analysis of housing patterns in Mexico City by utilizing an extensive database of 16,000 prices for flats and houses, covering the period from 2000 to 2022. Our findings reveal a striking trend: The average housing prices have quadrupled over a 20-y period, without considering inflation. In contrast, the per capita labor income of Mexican citizens has declined relative to inflation. As a result, the average family encountered four times greater challenges in accessing housing in 2015 as compared to 2005. Furthermore, our research demonstrates that areas that have undergone significant gentrification or super-gentrification contribute to a widespread increase in land value on neighboring zones, leading to the emergence of clusters of highly expensive neighborhoods.
Pyrenoid proteomics reveals independent evolution of the CO2-concentrating organelle in chlorarachniophytes
Authors: Moromizato Rena , Fukuda Kodai , Suzuki Shigekatsu , Motomura Taizo , Nagasato Chikako , Hirakawa Yoshihisa
Published: February 2024

Pyrenoids are microcompartments that are universally found in the photosynthetic plastids of various eukaryotic algae. They contain ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and play a pivotal role in facilitating CO2assimilation via CO2-concentrating mechanisms (CCMs). Recent investigations involving model algae have revealed that pyrenoid-associated proteins participate in pyrenoid biogenesis and CCMs. However, these organisms represent only a small part of algal lineages, which limits our comprehensive understanding of the diversity and evolution of pyrenoid-based CCMs. Here we report a pyrenoid proteome of the chlorarachniophyte algaAmorphochlora amoebiformis, which possesses complex plastids acquired through secondary endosymbiosis with green algae. Proteomic analysis using mass spectrometry resulted in the identification of 154 potential pyrenoid components. Subsequent localization experiments demonstrated the specific targeting of eight proteins to pyrenoids. These included a putative Rubisco-binding linker, carbonic anhydrase, membrane transporter, and uncharacterized GTPase proteins. Notably, most of these proteins were unique to this algal lineage. We suggest a plausible scenario in which pyrenoids in chlorarachniophytes have evolved independently, as their components are not inherited from green algal pyrenoids.
Towards a graded lexical inventory of multi-word combinations
Authors: Cuberos Vicente Rocío , Rosado Villegas Elisa , Mañas Navarrete Iban
Published: February 2024

Collocations have become increasingly important in our understanding of foreign language learning. When it comes to setting vocabulary learning goals, concerns about how to address collocations still arise today. This article explores the distribution of collocations in L1 and L2 Spanish production with the ultimate goal of informing the design of graded lexical inventories of multi-word combinations. To do so, we explore three defining properties of collocations in L1 and L2 production data, and across different levels of L2 proficiency: syntactic structure, semantic transparency, and the strength of association. Results indicate that there is an increase of collocational density and diversity, but that isolated features of collocations fail to predict L2 proficiency. Findings suggest the need to evaluate collocation use at a high level of granularity.
An LED-Side-Pumped Intracavity Frequency-Doubled Nd,Ce:YAG Laser Producing a 2W Q-Switched Red Beam
Authors: Shen 沈 Jianping 建平 , Xu 徐 Shaocong 少聪 , LU 芦 Peng 鹏 , Jiang 江 Rongrong 容容 , Wang 王 Wei 巍 , Zhang 张 Siwei 四维 , Xing 邢 Fengyang 凤阳 , Chen 陈 Yang 阳 , Chen 陈 Liang 亮
Published: February 2024

We report a high-average-power acousto-optic (AO) Q-switched intracavity frequency-doubled red laser based on a high-efficiency light-emitting-diode (LED) pumped two-rod Nd,Ce:YAG laser module. Under quasi-continuous wave operation conditions, a maximum output power of 1319.08 nm wavelength was achieved at 11.26 W at a repetition rate of 100 Hz, corresponding to a maximum optical efficiency of 13.9% and a slope efficiency of 17.9%. In the active Q-switched regime, the pulse energy of the laser was as high as 800 μJ at a repetition rate of 10 kHz with a pulse width of 1.5 μs. Under non-critical phase-matched KTP crystal conditions, an average power of 2.03 W of 658.66 nm through intracavity frequency-doubling was obtained at a repetition frequency of 10 kHz with a duration of 1.3 μs, and the M
2 factor was measured to be about 5.8. To the best of our knowledge, this is the highest average power of an LED-pumped AO Q-switched 1319 nm laser and intracavity frequency-doubled red laser reported to date.
Hybrid Skin-Topological Effect Induced by Eight-Site Cells and Arbitrary Adjustment of the Localization of Topological Edge States
Authors: Chen 陈 Jianzhi 健智 , Shi 史 Aoqian 奥芊 , Peng 彭 Yuchen 宇宸 , Peng 彭 Peng 鹏 , Liu 刘 Jianjun 建军
Published: February 2024

Hybrid skin-topological effect (HSTE) in non-Hermitian systems exhibits both the skin effect and topological protection, offering a novel mechanism for localization of topological edge states (TESs) in electrons, circuits, and photons. However, it remains unclear whether the HSTE can be realized in quasicrystals, and the unique structure of quasicrystals with multi-site cells may provide novel localization phenomena for TESs induced by the HSTE. We propose an eight-site cell in two-dimensional quasicrystals and realize the HSTE with eight-site nonreciprocal intracell hoppings. Furthermore, we can arbitrarily adjust the eigenfield distributions of the TESs and discover domain walls associated with effective dissipation and their correlation with localization. We present a new scheme to precisely adjust the energy distribution in non-Hermitian quasicrystals with arbitrary polygonal outer boundaries.
MWCNT Doped Reverse-Mode Polymer Network Liquid Crystals with Frequency Response Property
Authors: Li 李 Jiajun 佳峻 , Ji 姬 Dongchao 栋超 , Zhang 张 Zhibo 智博 , Yang 杨 Yanan 亚楠 , Zhang 张 Ruicong 锐聪 , Wang 王 Tianyu 天宇 , Zhang 张 Yumin 宇民 , Cao 曹 Wenxin 文鑫 , Zhu 朱 Jiaqi 嘉琦
Published: February 2024

Polymer-liquid crystals (PLCs) are common materials for smart windows. However, PLC smart windows usually require high driving voltage to maintain transparency. We synthesized a novel PLC smart film by doping multi-wall carbon nanotubes (MWCNTs) into a reverse-mode polymer network liquid crystal (R-PNLC). It is found that doping MWCNTs could effectively reduce the threshold voltage (V
th) of R-PNLC from 19.0 V to 8.4 V. Due to co-orientation between MWCNT and LC molecules, the doped R-PNLC is able to maintain a high transmittance of visible light (∼ 80%) without an applied electric field. We find that doping MWCNTs could change the frequency modulation property of R-PNLC. The doped R-PNLC exhibits a wider frequency modulation range up to 40000 Hz, while the frequency modulation of the undoped R-PNLC reached to a saturation at 23000 Hz. We also tested the electromagnetic interference (EMI) shielding efficiency of R-PNLC and find that the EMI shielding efficiency could be improved by doping only 0.01 wt% MWCNTs into the system. The total shielding effectiveness of 0.01 wt% MWCNT doped R-PNLC was up to 14.91 dB in the frequency band of 5.38–8.17 GHz. This study demonstrates that the films are potentially useful for low-energy-consumption smart windows with enhanced electromagnetic shielding capability.
Hard Superconducting Gap in PbTe Nanowires
Authors: Gao 高 Yichun 益淳 , Song 宋 Wenyu 文玉 , Yang 杨 Shuai 帅 , Yu 于 Zehao 泽昊 , Li 李 Ruidong 睿东 , Miao 苗 Wentao 文韬 , Wang 王 Yuhao 禹灏 , Chen 陈 Fangting 芳婷 , Geng 耿 Zuhan 祖汗 , Yang 杨 Lining 利宁 , Xia 夏 Zezhou 泽洲 , Feng 冯 Xiao 硝 , Zang 臧 Yunyi 运祎 , Li 李 Lin 琳 , Shang 尚 Runan 汝南 , Xue 薛 Qi-Kun 其坤 , He 何 Ke 珂 , Zhang 张 Hao 浩
Published: February 2024

Semiconductor nanowires coupled to a superconductor provide a powerful testbed for quantum device physics such as Majorana zero modes and gate-tunable hybrid qubits. The performance of these quantum devices heavily relies on the quality of the induced superconducting gap. A hard gap, evident as vanishing subgap conductance in tunneling spectroscopy, is both necessary and desired. A hard gap has been achieved and extensively studied before in III–V semiconductor nanowires (InAs and InSb). In this study, we present the observation of a hard superconducting gap in PbTe nanowires coupled to a superconductor Pb. The gap size Δ is ∼ 1 meV (maximally 1.3 meV in one device). Additionally, subgap Andreev bound states can also be created and controlled through gate tuning. Tuning a device into the open regime can reveal Andreev enhancement of the subgap conductance. These results pave the way for diverse superconducting quantum devices based on PbTe nanowires.
Universality of the quantum energy flux at the inner horizon of asymptotically de Sitter black holes
Authors: Hintz Peter , Klein Christiane K M
Published: February 2024

Recently, it was found that the energy flux of a free scalar quantum field on a Reissner–Nordström–de Sitter spacetime has a quadratic divergence towards the inner horizon of the black hole. Moreover, the leading divergence was found to be state independent as long as the spectral gap of the wave equation on the spacetime is sufficiently large. In this work, we show that the latter result can be extended to all subextremal Reissner–Nordström–de Sitter and subextremal Kerr–de Sitter spacetimes with a positive spectral gap.
A horizontally driven inverted pendulum
Authors: Cross Rod
Published: February 2024

An inverted pendulum can be stabilised by hand or by a high frequency sinusoidal vertical oscillation of the bottom end or by feedback control if a horizontal force is applied at the bottom end. The pendulum is unstable if a sinusoidal force is applied in a horizontal direction at the bottom end. It is shown in the present paper that an inverted pendulum can be stabilised if a low frequency horizontal force is applied at the bottom end to right the pendulum after it falls through a small angle. The technique requires a measurement of the fall angle but is not sensitive to the actual fall angle. The technique represents a simple example of feedback control and is more easily understood than vertical oscillation of the bottom end.
An efficient parameter-retrieval-based surrogate-assisted optimization of on-platform honeycomb absorbing structures
Authors: Yang Yiting , Yu Wen Ming , Cui Tie Jun
Published: February 2024

An electromagnetic parameter-retrieval-based surrogate-assisted optimization (PSAO) algorithm is presented to reduce radar cross section (RCS) by optimizing the on-platform honeycomb absorbing structures. To facilitate the optimization process, the honeycomb structure is transformed to an anisotropic homogeneous slab, and the effective parameters of the slab are extracted by the retrieval algorithm. A multi-fidelity model is employed to reduce the computing-time consumption, in which a Gaussian process (GP) regression model is used as the substitute for the coarse model. The GP model establishes a relationship between the geometry of the honeycomb structure and the RCS response of the target coated with the equivalent slab. Finally, the optimization result of the fine model is achieved through a space mapping strategy. The accuracy of the parameter extraction algorithm is verified by analyzing the honeycomb absorbing structure. Subsequently, the proposed optimization method is applied to a metal plate and a metal cylinder, resulting in a 10 dB reduction of RCS in broadband and wide-angle scenarios. This demonstrates the applicability of the proposed PSAO algorithm to both planar and conformal on-platform honeycomb absorbing structures. Furthermore, an NACA0015 foil is analyzed, showing an average RCS reduction of 10 dB and a minimum RCS reduction of 5 dB in the X-band. These results indicate that the PSAO approach can effectively apply to complicated targets. Additionally, the proposed method exhibits significant advantages in terms of computational accuracy and efficiency compared to the traditional genetic algorithm.
Magnetic anisotropy, magnetization reversal and switching in Ni4Nb2O9 single crystals
Authors: Martin C , Hervé L , Sedmidubsky D , Bolletta J P , Damay F , Maignan A
Published: February 2024

Ni4Nb2O9 is an insulating compensated ferrimagnet with TN
= 77 K and T
comp= 33 K. We report here the study of the magnetic anisotropy using millimeter-size crystals grown in an image furnace. The magnetization measurements, vs temperature, performed with H aligned along the three main crystallographic axes, show similar Curie–Weiss temperatures (Θp
≈ 190 K) and rather similar effective paramagnetic moments (from 3.5 μ
B to 3.6 μ
B). This suggests that the strongest magnetic interaction is the antiferromagnetic one, coupling the ferromagnetic distorted honeycomb layers and zigzag ribbons via face sharing NiO6 octahedra. This strong antiferromagnetic coupling is supported by DFT calculations that do not evidence any inter site ferromagnetic interaction, leading to total compensation between magnetic moments of both Ni2+ sites. Measurements vs magnetic field below TN
reveal an anisotropic behaviour, with square magnetization loops for H in the ab plane, whereas linear M(H) curves without hysteresis are observed for H‖c. This anisotropy between ab plane and c axis occurs also in the magnetization reversal (MR), which is observed in the ab plane only. Starting from M(H) virgin curves collected just below T
comp= 33 K with H‖a or H‖b, the memory-like effect was tested through magnetization switching induced by H or T alternating changes. Below T
comp, smaller H is needed to switch M symmetrically for H along b than along a, and, for T switching (2 K interval, constant H), a larger M change is obtained along a than along b. The comparison with ferrimagnetic oxides which exhibit MR, like spinels or rare earth orthoferrites, shows that Ni4Nb2O9 is unique since only one magnetic cation over two sites in octahedral coordination is at play, thus providing a unique platform to study M switching but also a challenge for theoretical interpretation.
Computational screening of layered metal chalcogenide materials for HER electrocatalysts, and its synergy with experiments
Authors: Sen Prasenjit
Published: February 2024

Layered materials have emerged as attractive candidates in our search for abundant, inexpensive and efficient hydrogen evolution reaction (HER) catalysts, due to larger specific area these offer. Among these, transition metal dichalcogenides have been studied extensively, while ternary transition metal tri-chalcogenides have emerged as promising candidates recently. Computational screening has emerged as a powerful tool to identify the promising materials out of an initial set for specific applications, and has been employed for identifying HER catalysts also. This article presents a comprehensive review of how computational screening studies based on density functional calculations have successfully identified the promising materials among the layered transition metal di- and tri-chalcogenides. Synergy of these computational studies with experiments is also reviewed. It is argued that experimental verification of the materials, predicted to be efficient catalysts but not yet tested, will enlarge the list of materials that hold promise to replace expensive platinum, and will help ushering in the much awaited hydrogen economy.
IRGD-modified erythrocyte membrane biomimetic temozolomide nanodots for the treatment of glioblastoma
Authors: Luo Dong , Chen Zhichao , Peng Yaonan , Liu Chaoran
Published: February 2024

The crossing of the blood-brain barrier (BBB) for conventional anticancer drugs is still a big challenge in treating glioma. The biomimetic nanoparticle delivery system has attracted increasing attention and has a promising future for crossing the BBB. Herein, we construct a multifunctional biomimetic nanoplatform using the erythrocyte membrane (EM) with the tumor-penetrating peptide iRGD (CRGDK/RGPD/EC) as a delivery, and the inner core loaded with the chemotherapeutic drug temozolomide (TMZ). The resulting biomimetic nanoparticle has perfect biocompatibility and stealth ability, which will provide more chances to escape the reticuloendothelial system (RES) entrapment, and increase the opportunity to enter the tumor site. Moreover, the decorated iRGD has been extensively used to actively targeting and deliver therapeutic agents across the BBB into glioma tissue. We show that this biomimetic delivery of TMZ with a diameter of 22 nm efficiently slowed the growth of glioblastoma multiforme (GBM) and increased the survival rate of the 30 d from 0% to 100%.
Motion-artifact-augmented pseudo-label network for semi-supervised brain tumor segmentation
Authors: Qu Guangcan , Lu Beichen , Shi Jialin , Wang Ziyi , Yuan Yaping , Xia Yifan , Pan Zhifang , Lin Yezhi
Published: February 2024

MRI image segmentation is widely used in clinical practice as a prerequisite and a key for diagnosing brain tumors. The quest for an accurate automated segmentation method for brain tumor images, aiming to ease clinical doctors’ workload, has gained significant attention as a research focal point. Despite the success of fully supervised methods in brain tumor segmentation, challenges remain. Due to the high cost involved in annotating medical images, the dataset available for training fully supervised methods is very limited. Additionally, medical images are prone to noise and motion artifacts, negatively impacting quality. In this work, we propose MAPSS, a motion-artifact-augmented pseudo-label network for semi-supervised segmentation. Our method combines motion artifact data augmentation with the pseudo-label semi-supervised training framework. We conduct several experiments under different semi-supervised settings on a publicly available dataset BraTS2020 for brain tumor segmentation. The experimental results show that MAPSS achieves accurate brain tumor segmentation with only a small amount of labeled data and maintains robustness in motion-artifact-influenced images. We also assess the generalization performance of MAPSS using the Left Atrium dataset. Our algorithm is of great significance for assisting doctors in formulating treatment plans and improving treatment quality.
Quantum random number generation using an on-chip nanowire plasmonic waveguide
Authors: Strydom C , Soleymani S , Özdemir Ş K , Tame M S
Published: February 2024

Quantum random number generators employ the inherent randomness of quantum mechanics to generate truly unpredictable random numbers, which are essential in cryptographic applications. While a great variety of quantum random number generators have been realized using photonics, few exploit the high-field confinement offered by plasmonics, which enables device footprints an order of magnitude smaller in size. Here we integrate an on-chip nanowire plasmonic waveguide into an optical time-of-arrival based quantum random number generation setup. Despite loss, we achieve a random number generation rate of

14.4

Mbits

s

−
1

using low light intensity, with the generated bits passing industry standard tests without post-processing. By increasing the light intensity, we were then able to increase the generation rate to

41.4

Mbits

s

−
1

, with the resulting bits only requiring a shuffle to pass all tests. This is an order of magnitude increase in the generation rate and decrease in the device size compared to previous work. Our experiment demonstrates the successful integration of an on-chip nanoscale plasmonic component into a quantum random number generation setup. This may lead to new opportunities in compact and scalable quantum random number generation.
CHSH Bell tests for optical hybrid entanglement
Authors: Moradi Morteza , Camilo López Carreño Juan , Buraczewski Adam , McDermott Thomas , Elisabeth Asenbeck Beate , Laurat Julien , Stobińska Magdalena
Published: February 2024

Optical hybrid entanglement can be created between two qubits, one encoded in a single photon and another one in coherent states with opposite phases. It opens the path to a variety of quantum technologies, such as heterogeneous quantum networks, merging continuous- and discrete-variable encoding, and enabling the transport and interconversion of information. However, reliable characterization of the non-local nature of this quantum state is limited so far to full quantum state tomography. Here, we perform a thorough study of Clauser–Horne–Shimony–Holt Bell inequality tests, enabling practical verification of quantum nonlocality for optical hybrid entanglement. We show that a practical violation of this inequality is possible with simple photon number on/off measurements if detection efficiencies stay above 82%. Another approach, based on photon-number parity measurements, requires 94% efficiency but works well in the limit of higher photon populations. Both tests use no postselection of the measurement outcomes and they are free of the fair-sampling hypothesis. Our proposal paves the way to performing loophole-free tests using feasible experimental tasks such as coherent state interference and photon counting.
Perfect chirality constructed by position-dependent backscattering in a whispering gallery mode microresonator
Authors: Ma Xin-Yue , Li Ming , Zhang Yan-Lei , Xu Xin-Biao , Tang Lei , Yan Cong-Hua
Published: February 2024

Unidirectional propagation of photons originated from perfect chirality meets the critical requirement for building a high-performance quantum network. However, it not only requires that the circular dipole emitter is precisely located at points of circularly polarized electric fields, which leads to non-reciprocal interactions for photons with opposite propagation directions, but also the light-emitter interaction strength should be strong enough to guarantee a π phase shift. Unfortunately, these perfect chirality points are scarce and accessible points with elliptically polarized fields result in non-ideal photon-emitter chiral interactions and emitters radiating photons bidirectionally. Meanwhile, reflection properties, phase shifts, and non-reciprocal interactions are sensitive to frequency detunings and dissipations. Here, without engineering the dipole and optimizing the distribution of the field, a scatter such as a nanotip placed at the evanescent field of a whispering gallery mode resonator (WGMR) is adopted to control the transporting properties of single photons under non-ideal chiral interactions. By properly adjusting the relative position between the nanotip and the atom or the overlap between the nanotip and the mode volume of the WGMR, amplitudes of reflected photons in different pathways are changed. Consequently, complete destructive interference appears and thus no photons are reflected. The corresponding phase shifts of π and non-reciprocal interactions are guaranteed simultaneously. Significantly, the perfect chirality reconstructed here is robust against frequency detunings and dissipations. Therefore, the atom-WGMR-nanotip structure can be regarded as a compound chiral atom with radiating photons in only one direction.
SAR dynamical mechanism affected by diminishing marginal effect based on personal fashion psychology on multi-layer contacted network
Authors: Ren Yuemei , Li Lei
Published: February 2024

People in complex systems exhibit varying capacities for social interaction because of differences in personal psychology, educational attainment, and social class. It is true that people often use different social networks and show different enthusiasm for obtaining information, but their interest in collecting information will decrease over time. Our study on Personal Fashion Psychology (PFP) has shown that when people get information, they behave in a way known as the Diminishing Marginal Effect (DME-PFP behavior). Next, we created a SAR propagation dynamics model on a multi-layer contact network to represent DME-PFP behavior using a threshold function. Then, to assess and uncover the transmission mechanism of individual behaviour, we use partition theory. A boundary phenomena is displayed by the propagation mode, as demonstrated by both theoretical analysis and simulated tests. The final size can exhibit either discontinuous first-order phase transitions or continuous second-order phase changes in individual DME-PFP behaviour. Meanwhile, through the unit transmission probability changed, the ideal DME-PFP parameters occur at the largest final adoption size. Moreover, the promotion of the propagation pattern and behaviour from continuous second-order to discontinuous first-order is facilitated by interpersonal contact. The numerical analysis and the actual models may eventually agree.
Harmonic oscillator with a step and its isospectral properties
Authors: Nasuda Yuta , Sawado Nobuyuki
Published: February 2024

We investigate the one-dimensional Schrödinger equation for a harmonic oscillator with a finite jump a at the origin. The solution is constructed by employing the ordinary matching-of-wavefunctions technique. For the special choices of a, a = 4ℓ (ℓ = 1, 2, …), the wavefunctions can be expressed by the Hermite polynomials. Moreover, we explore isospectral deformations of the potential via the Darboux transformation. In this context, infinitely many isospectral Hamiltonians to the ordinary harmonic oscillator are obtained.
Efficient light propagation algorithm using quantum computers
Authors: Cholsuk Chanaprom , Davani Siavash , Conlon Lorcán O , Vogl Tobias , Eilenberger Falk
Published: February 2024

Quantum algorithms can potentially overcome the boundary of computationally hard problems. One of the cornerstones in modern optics is the beam propagation algorithm, facilitating the calculation of how waves with a particular dispersion relation propagate in time and space. This algorithm solves the wave propagation equation by Fourier transformation, multiplication with a transfer function, and subsequent back transformation. This transfer function is determined from the respective dispersion relation, which can often be expanded as a polynomial. In the case of paraxial wave propagation in free space or picosecond pulse propagation, this expansion can be truncated after the quadratic term. The classical solution to the wave propagation requires

O
(
NlogN
)

computation steps, where N is the number of points into which the wave function is discretized. Here, we show that the propagation can be performed as a quantum algorithm with

O

logN

2

single-controlled phase gates, indicating exponentially reduced computational complexity. We herein demonstrate this quantum beam propagation method (QBPM) and perform such propagation in both one- and two-dimensional systems for the double-slit experiment and Gaussian beam propagation. We highlight the importance of the selection of suitable observables to retain the quantum advantage in the face of the statistical nature of the quantum measurement process, which leads to sampling errors that do not exist in classical solutions.
Biomass residues purification: elimination of oxygen from oxolane and its monomethylated derivatives through hydrodeoxygenation process
Authors: Koudjina Simplice , Kosar Naveen , Kpotin Gaston A , Thomas Affi Sopi , Mahmood Tariq , Atohoun Guy Y S
Published: February 2024

The persistent global demand of fossil fuels has spurred significant interest in the invention of new renewable energy sources to replace finite, non-renewable fossil fuels. Among these sustainable energy options, biomass stands out as a promising candidate as environment friendly alternative fuel. However, the organic compounds found in biomass contain a high oxygen content, leading to several undesirable characteristics in biofuels, including low energy density, less stability, high viscosity, and corrosion. Consequently, researchers have devised various upgrading techniques, with a particular emphasis on the hydrodeoxygenation (HDO) process, to enhance the quality of biofuel. In this report, we investigated the treatment of Oxolane, 2-Methyloxolane and 3-Methyloxolane via adsorption and catalytic hydrogenolysis (HDL) processes. These processes aim to remove the oxygen heteroatom from these compounds, ultimately achieving the desired purity levels. To elucidate the underlying mechanisms, we employed the B3LYP/6–31G(d) and LanL2DZ/6–31G(d) methods of DFT for reaction without or with catalysts. The hydrogenolysis, in the presence and absence of a catalyst is carried at a temperature and pressure of 523 K and 40 bar, respectively. We meticulously analyzed the variations in geometries, thermodynamic and kinetic properties to gain insights into the whole processes. For each molecule, the sequence involves ring opening of C–O bond, followed by the elimination of a water molecule. The first hydrogenolysis step yields an alcohol as a reaction intermediate, while the second hydrogenolysis step results in the formation of an alkane. Geometric parameters showed the increased reactivity of Oxolane and its derivatives in the presence of tungsten disulphide (WS2) catalyst. Chemical potential indicates the charge transfer occurred in all, and the highest charge transfer is observed in Oxolane in the presence of tungsten disulphide (WS2) catalyst.
3D chaotic mixing application for polymer production
Authors: Yagmur Dogucan , Kutlu Mustafa
Published: February 2024

Industrial mixing processes have garnered significant attention over the past decade due to the critical role that efficient and rapid mixing plays in the production of innovative materials. The methodology employed in mixing fundamentally influences the physical and chemical attributes of the resultant mixture. As such, various mixing techniques have been developed, aiming to produce polymers with tailored properties for specific applications, including tissue engineering, artificial muscles, and soft robotics. In this study, the mixing process of RTV 2710 silicone rubber and Catalyst CX catalyst was conducted using the Halvorsen, Newton-Leipnik, Hadley, and Sprott A. systems. Numerical values were derived by solving chaotic differential equations associated with each system. The speed of the DC motor driving the mixing propeller was modulated chaotically to optimize mixing efficiency. To enhance energy efficiency, energy consumption was monitored, revealing that the Hadley-2 signal was the most energy-efficient among the chaotic signals tested. Samples were prepared using SCARA(Selective Compliance Articulated Robot Arm) to trace trajectories for all chaotic systems, followed by tensile tests to evaluate their mechanical properties. The Sprott A. chaotic system yielded the highest average force and tensile strength. Furthermore, samples were produced with constant position and varying velocities—specifically Hadley 2 and Sprott A. position combined with Hadley 2 velocity—and subjected to tensile tests. The results demonstrated that the combination of Sprott A. position and Hadley 2 velocity produced samples with superior average force and tensile strength.