bluuebunny/crossref_metadata_2025 huggingface dataset:
Renal-clearable porous hollow copper iron oxide nanoparticles for trimodal chemodynamic-photothermal-chemo anti-tumor therapy
Authors: Feng Kai , Xu Zhengtao , Wang Yuhan , Wu Xiyao , Xiong Fucheng , Ruan Yiling , Wu Xiaojing , Ye Linqian , Su Dong , Yu Jing , Sun Xiaolian
Published: January 2023

Cisplatin-loaded porous hollow copper iron oxide nanoparticles (PHCuFeNPs/Pt) synthesized via galvanic reaction can effectively kill tumors by synergizing chemodynamic-photothermal-chemotherapy.
Lithium anthraquinoids as catalysts in the ROP of lactide and caprolactone into cyclic polymers
Authors: Ruiz Martínez Cristina , Pérez Juana M. , Arrabal-Campos Francisco M. , Rodríguez-Diéguez Antonio , Choquesillo-Lazarte Duane , Martínez-Lao Juan A. , Ortuño Manuel A. , Fernández Ignacio
Published: January 2023

New lithium anthraquinoids 2b–d active in the synthesis of cyclic PLA and cyclic PCL have been synthesized and fully characterized.
Dumbbell-like polyionic complexes of dendronized poly(ethylene glycol): synthesis and self-assembly studies
Authors: Khatuntsev Sergey , Fanova Anastasiia , Fetin Petr , Kaberov Leonid I. , Girbasova Nina , Lezov Alexey A. , Zorin Ivan , Bilibin Alexander
Published: January 2023

Synthesis and self-organization studies of polyionic complexes of linear–dendritic copolymers based on polyethylene glycols bearing aspartic dendrons with terminal amino and carboxylic groups.
Ultrathin black TiO2 nanosheet-assembled microspheres with high stability for efficient solar-driven photocatalytic hydrogen evolution
Authors: Wang Chunyan , Kang Xin , Liu Jiancong , Wang Dongxu , Wang Nan , Chen Jie , Wang Jing , Tian Chungui , Fu Honggang
Published: January 2023

We applied a small amine molecule protective agent to synthesize high-thermally stable black TiO2 with high specific surface area, broad optical absorption, and increased charge separation, which exhibits excellent photocatalytic performance.
A natural polymer with desirable self-healing and recyclable, antibacterial, and adhesive properties based on turpentine monomer
Authors: Wang Shanshan , Zhou Yuemin , Wang Yuqi , Dong Fuhao , Liu He , Xu Xu
Published: January 2023

A natural polymer with good self-healing, recyclable, antibacterial, and adhesive properties was designed and prepared with thioctic acid and turpentine monomers.
A general protocol for stereoselective construction of enaminyl sulfonyl fluorides
Authors: Chen Liu-Yang , Rakesh K. P. , Qin Hua-Li
Published: January 2023

A simple, efficient, and mild reaction of 2-chloroprop-2-ene-1-sulfonyl fluoride (CESF) with amines was developed, affording a variety of highly functionalized enaminyl sulfonyl fluorides in good to excellent yields (56–96%).
Viable production of hydrogen and methane from polluted water using eco-friendly plasmonic Pd–TiO2 nanocomposites
Authors: Mbrouk Omar , Fawzy M. , El-Shafey H. M. , Saif M. , Abdel Mottaleb M. S. A. , Hafez H.
Published: January 2023

A mechanistic schematic diagram of the occurred reactions in the photoreaction; the Pd–TiO2 plasmonic photocatalysts demonstrate promising dual functional materials generation of helpful fuel gases from the destruction of organic matter.
Correction: The influence of electron utilization pathways on photosystem I photochemistry in Synechocystis sp. PCC 6803
Authors: Smolinski Sharon L. , Lubner Carolyn E. , Guo Zhanjun , Artz Jacob H. , Brown Katherine A. , Mulder David W. , King Paul W.
Published: January 2023

Correction for ‘The influence of electron utilization pathways on photosystem I photochemistry in Synechocystis sp. PCC 6803’ by Sharon L. Smolinski et al., RSC Adv., 2022, 12, 14655–14664, https://doi.org/10.1039/d2ra01295b.
Compact hydrophilic electrophiles enable highly efficacious high DAR ADCs with excellent in vivo PK profile
Authors: Ochtrop Philipp , Jahzerah Jahaziel , Machui Paul , Mai Isabelle , Schumacher Dominik , Helma Jonas , Kasper Marc-André , Hackenberger Christian P. R.
Published: January 2023

Compact phosphonamidate building blocks enable the simple construction of homogeneous DAR8 ADCs from native antibodies and hydrophobic payloads. The resulting ADCs exhibit excellent in vivo stability, clearance rates and antitumor activity.
High-throughput identification of materials for silicon tandem solar cells
Authors: Zhao Yanzhen , Yao Zhikun , Liu Chang , Ren Wei , Hautier Geoffroy , Burton Lee A.
Published: January 2023

High-throughput ab initio calculations are employed to identify the most promising materials for Si tandem solar cells from over 100 000 candidates.
Magnetic properties of a soft magnetic elastomer based on antioxidant magnetic composite particles and a water-soluble polymer matrix
Authors: Si Xiaodong , Luo Mingliang , Li Mingzhong , Ma Yuben , Huang Yige , Ge Yunzhi
Published: January 2023

A soft magnetic elastomer, called a magnetorheological elastomer (MRE), based on a polyacrylamide (PAM) modified carbonyl iron particle (P-CIP) composite and a water-soluble PAM matrix was designed and prepared.
Controllable vacancy strategy mediated by organic ligands of nickel fluoride alkoxides for high-performance aqueous energy storage
Authors: Shi Wei , Meng Zeshuo , Xu Zijin , Xu Jian , Sun Xucong , Nan Haoshan , Zhang Chenxu , Yu Shansheng , Hu Xiaoying , Tian Hongwei
Published: January 2023

Controllable vacancy engineering strategy plays a significant role in the rational design of electrochemical energy conversion and storage.
Design of carbon dots as nanozymes to mediate redox biological processes
Authors: He Qian , Zhang Liyun
Published: January 2023

Fluorescent carbon dot nanozymes with multi-enzyme activities can mediate redox biological processes. Various strategies which mimic natural enzymes can be used to improve their catalytic activity and specificity.
A review on borate bioactive glasses (BBG): effect of doping elements, degradation, and applications
Authors: Abodunrin Oluwatosin David , El Mabrouk Khalil , Bricha Meriame
Published: January 2023

Mecanisme for HAp layer deposition on bioglasses based on silicate and borate 3D structure.
Fluorescent phosphine oxide-containing hyperbranched polyesters: design, synthesis and their application for Fe3+detection
Authors: Sun Jian , Hong Yu-Lin , Fang Xiu-Qin , Wang Chang , Liu Cheng-Mei
Published: January 2023

Herein, fluorescent phosphorus-containing hyperbranched polyesters (HBPs) were synthesizedviathe solvent-free polycondensation of phosphine oxide-based AB2monomer (A: carboxyl or ester; B: hydroxyl) by adding trimethylolpropane as the core for the first time.
Experimental determination of metals generated during the thermal failure of lithium ion batteries
Authors: Buston Jonathan E. H. , Gill Jason , Lisseman Rebecca , Morton Jackie , Musgrove Darren , Williams Rhiannon C. E.
Published: January 2023

This work describes the deliberate failure of lithium-ion cells, and subsequent analysis of both the smoke and near field residue for the metals commonly found in battery cathodes.
Replication in Evidence-Based Aphasia Treatments
Authors: Karidas Stephanie , Hinckley Jacqueline J. , Brekher Izabelle
Published: January 2023

Purpose:

A critical review was completed to evaluate replication of aphasia treatments that have been vetted and accepted on the American Speech-Language-Hearing Association Practice Portal.

Method:

The electronic databases Academic Search Premier, ProQuest Central, CINAHL Complete, and ERIC were searched for relevant articles using treatment names as keywords. Coders compared stimuli, material, design, and statistical analysis to pilot treatment approaches. Each study was coded as direct, conceptual, failed, or no replication.

Results:

Eighteen treatment approaches were selected for this review. A total of 188 articles met the inclusion criteria. Results revealed that 14 out of 18 treatment approaches were somehow replicated. Direct replications as the most valuable replication type for affirming previously found results were represented in only 1.5% of all studies (3/188). Failed direct replication were at 2% overall (4/188). Conceptual replications were more common across treatment approaches, but also represented at a low level with 22.8% (43/188). The majority of studies were coded as no replication attempt with 73.4%.

Discussion:

A critical factor in developing an evidence-based practice is the existence of replicated results for treatment. Replication evaluates the reproducibility of an author's or authors' research methodology and resulting outcomes and helps to ensure that observed treatment effects are reproducible. For an evidence-based treatment to be implemented or used in any clinical setting, it must be one that can be replicated. Direct and conceptual replications of aphasia treatment approaches were found to be alarmingly low considering the importance of replication in our field. It is recommended that replication should become more valued and mainstreamed in aphasia research. A replication database that compiles and maintains treatment manuals for replication purposes can increase the accessibility and acceptability of replications for researchers.
A dynamic relative displacement evaluation method for extra‐high voltage transformer withstanding short‐circuit impact
Authors: Ou Qiang , Luo Longfu , Li Yong , Lin Yantao , Tian Ye
Published: January 2023

The extra‐high voltage (EHV) transformer winding disks are subjected to dynamic electromagnetic forces caused by short‐circuit currents. These periodically decaying impact forces may endanger the safety of the transformer. The winding constraint conditions around the circumference are different due to the influence of axial pressure structures and magnetic boundaries. Moreover, this difference becomes more evident as the voltage and capacity increase. To investigate the spatial differences and time effects of EHV transformer short‐circuit faults, this paper proposes a reliability evaluation method based on dynamic relative displacement (DRDEM) for the first time. Firstly, the suitable and efficient analysis method is summarized by comparing the deviation among different calculated impedances and the measured value. Then, the space‐time effect of windings is obtained by the static magnetic field and dynamic structural field based on equivalent compression supports. Furthermore, a 50 MVA/110 kV transformer is designed for the destructive short‐circuit test to simulate the short‐circuit ability feature of the EHV transformer. The disassembly phenomena after all the tests indicate that the DRDEM is more adaptable in characterizing the winding ability to withstand short circuit when investigating the spatial differences and time effects.
A Xanthoceras sorbifolium crack segmentation method based on an improved level set
Authors: Zhang Dan , Li Tieshan , Philip Chen C.L. , Wang Li
Published: January 2023

The dehiscence of the Xanthoceras sorbifolium (X. sorbifolium) may lead to seeds jump out and economic loss. The shape and the degree of the crack will provide the relevant elements for the study of the X. sorbifolium dehiscence and duly picked. Therefore, an improved level set method is proposed for X. sorbifolium crack segmentation. The problems of intensity inhomogeneity and so on, which pose challenges for accurate crack segmentation. The local Gaussian distribution fitting method has a good segmentation effect, but it is sensitive to the initial contour and does not use gradient information, which affects the accurate location of the edge. Aiming at the above problems and the scene of crack segmentation, this paper firstly adopts histogram threshold method to obtain the initial contour automatically. Secondly, the energy function is constructed by combining local and edge information. Finally, the double‐well potential function is used to reduce the oscillation and distortion of the method. In this paper, the experiment results show that the average boundary precision is 88.25% and average segmentation time of each image is 12.7s of the proposed method. After comprehensive analysis of IoU and boundary recall, the method in this paper achieves better results.
Bedeutung des differenzierten
Säuglingsbefunds
Authors: Ginsberg Iris
Published: January 2023

Indikationen zur Osteopathie beim jungen Säugling. Bedeutung
der Einbeziehung der Mutter/des Vaters des Säuglings
bei Befundung und Behandlung. Differenzierter neurologischer
Befund und Palpationsbefund. Bedeutung des Re-Befunds.
The link between foreign institutional owners and multinational enterprises’ environmental outcomes
Authors: Ellimäki Pia , Aguilera Ruth V. , Hurtado-Torres Nuria Esther , Aragón-Correa J. Alberto
Published: January 2023

Many institutional investors claim to be leaders in their commitment to sustainability, yet their real impact is undetermined. We look at the relationship between the presence of foreign institutional owners and the firm’s environmental outcomes in terms of performance and innovation. We argue that foreign institutional owners seek to mitigate their exposure to reputational risks by encouraging their investee firms to move towards better environmental performance. However, these owners are less likely to engage in long-term investments derived from environmental innovations. We examine these paradoxical motivations in the context of multinational enterprises (MNEs) in the chemical industry across 33 countries in emerging and developed markets and further explore how these investee firms’ international diversification affects these relationships. Our findings contribute to international corporate governance and sustainability research by uncovering that, contrary to institutional owners’ popular claims, foreign institutional owners have a positive effect on their investees’ environmental performance, but their influence is not statistically significant on environmental innovation. Specifically, the influence of foreign institutional owners on environmental performance is strong for MNEs with a low level of international diversification and marginal for those with a higher level of internationalization; meanwhile, domestic institutional owners are committed to advancing both environmental performance and innovation in their MNE investees. In sum, we show that environmental concerns are still quite localized.
Motivations for user satisfaction of mobile fitness applications: An analysis of user experience based on online review comments
Authors: Ahn Hyeongjin , Park Eunil
Published: January 2023

Considering that mobile fitness applications are one of the necessities in our lives, the user perspective toward the application is a prominent research topic in both academia and industry with the goal of improving such services. Thus, this study applies two different natural language processing approaches, bag-of-words, and sentiment analysis, to online review comments of the applications to examine the effects of user experience elements. The review dataset collected from 16,461 users, after pre-processing, revealed the notable roles of perceived affection and hedonic values in determining user satisfaction with the application, whereas the effect of user burden on satisfaction was marginal. Several implications, as well as limitations of the study, were examined incorporating the findings with the statistical results.
Cosmic particles probe ancient archeological site
Authors: Johnson-Groh Mara
Published: January 2023

Muons from space were used to map the 600-year-old defensive wall surrounding Xi’an, China, to aid restoration efforts.
Conceptual design of a GEM (gas electron multiplier) based gas Cherenkov detector for measurement of 17 MeV gamma rays from T(D, γ)5He in magnetic confinement fusion plasmas
Authors: Putignano O. , Croci G. , Muraro A. , Cancelli S. , Caruggi F. , Gorini G. , Grosso G. , Kushoro M. H. , Marcer G. , Nocente M. , Cippo E. Perelli , Rebai M. , Rigamonti D. , Tardocchi M.
Published: January 2023

The only method for assessing the fusion power throughput of a deuterium–tritium (DT) reactor presently relies on determining the absolute number of 14 MeV neutrons produced in the DT plasma. An independent method, developed and investigated during the recent DT campaign at the Joint European Torus, is based on the absolute counting of 17 MeV gamma rays produced by the competing T(D, γ)5He reaction that features a very weak branching ratio (about 3–6 × 10−6) when compared to the main T(D, n)4He reaction. The state-of-the-art spectrometer used for gamma-ray measurements in magnetic confinement fusion plasmas is LaBr3(Ce) scintillator detectors, although they require significant neutron shielding to extract a relatively weak gamma-ray signal from a much more abundant neutron field. A better approach relies on a gamma-ray detector that is intrinsically insensitive to neutrons. We have advanced the design of a gamma-ray counter based on the Cherenkov effect for gamma-rays whose energy exceeds 11 MeV, optimized to work in the neutron-rich environment of a steady-state, magnetically confined fusion plasma device. The gamma-rays interact with an aluminum window and extract electrons that move into the radiator emitting photons via the Cherenkov effect. Since the Cherenkov light consists of few photons (25 on average) in the far UV band (100–200 nm), a pre-amplifier is required to transport the photons to the neutron-shielded location, which may be a few meters away, where the readout elements of the detector, either a silicon or standard photomultiplier tube, are placed. The present work focuses on the development of a scintillating GEM (Gas Electron Multiplier) based pre-amplifier that acts as a Cherenkov photon pre-amplifier and wavelength shifter. This paper presents the result of a set of Garfield++ simulations developed to find the optimal GEM working parameters. A photon gain of 100 is obtained by biasing a single GEM foil to 1 kV.
High-resolution micro-cavity filling sensing by fiber optic interferometry
Authors: Jadidi Majid Fazeli , Gholamvand Zahra , Cross Graham L. W.
Published: January 2023

In the last decade, new potential applications of micro- and nano-products in telecommunication, medical diagnostics, photovoltaic, and optoelectronic systems have increased the interest to develop micro-engineering technologies. Injection molding of polymeric materials is a recent method being adapted for serial manufacturing of optic components and packaging at the micro- and nano-scale. Quality assurance of replication into small cavities is an important but underdeveloped factor that is needed to ensure high production efficiency in any micro-fabrication industry. In this work, we introduce a fiber-based interferometric measurement sensor to monitor the cavity filling of optical microstructures fabricated into a macroscopic molding die. The interferometer was capable of resolving melt front motion into the microcavity to the point of complete filling as verified by atomic force microscopy. Despite the low reflectivity of the transparent polymer and unoptimized reflected light collection optics, this system is capable of monitoring polymer movement during the course of filling and detecting the completion of the process. The simplicity and flexibility of the technology could allow eventual instrumentation of injection molds, embossing, and nanoimprint tooling suitably modified with a small optical window to accommodate light from an optical fiber. This would provide a solution to the challenging problem of monitoring local, nanometer scale filling processes.
Attractor radius for fractional Lorenz systems and their application to the quantification of predictability limits
Authors: Wang Yejuan , Wei Zhiqiang , Feng Guolin
Published: January 2023

Quantifying the predictability limits of chaotic systems and their forecast models has attracted much interest among scientists. The attractor radius (AR) and the global attractor radius (GAR), as intrinsic properties of a chaotic system, were introduced in the most recent work (Li et al. 2018). It has been shown that both the AR and GAR provide more accurate, objective metrics to access the global and local predictability limits of forecast models compared with the traditional error saturation or the asymptotic value. In this work, we consider the AR and GAR of fractional Lorenz systems, introduced in Grigorenko and Grigorenko [Phys. Rev. Lett. 91, 034101 (2003)] using the Caputo fractional derivatives and their application to the quantification of the predictability limits. A striking finding is that a fractional Lorenz system with smaller Σ, which is a sum of the orders of all involved equal derivatives, has smaller attractor radius and shorter predictability limits. In addition, we present a new numerical algorithm for the fractional Lorenz system, which is the generalized version of the standard fourth-order Runge–Kutta scheme.
Ultra-low noise, bi-polar, programmable current sources
Authors: Mrozowski M. S. , Chalmers I. C. , Ingleby S. J. , Griffin P. F. , Riis E.
Published: January 2023

We present the design process and implementation of fully open-source, ultra-low noise programmable current source systems in two configurations. Although originally designed as coil drivers for Optically Pumped Magnetometers (OPMs), the device specifications make them potentially useful in a range of applications. The devices feature a bi-directional current range of ±10 and ±250 mA on three independent channels with 16-bit resolution. Both devices feature a narrow 1/f noise bandwidth of 1 Hz, enabling magnetic field manipulation for high-performance OPMs. They exhibit a low noise of 146 pA/Hz and 4.1 nA/Hz, which translates to 15 and 16 ppb/Hz noise relative to full scale.
Efficient organic terahertz generator with extremely broad terahertz molecular vibrational mode-free range
Authors: Shin Bong-Rim , Yu In Cheol , Shin Myeong-Hoon , Jazbinsek Mojca , Rotermund Fabian , Kwon O-Pil
Published: January 2023

For nonlinear optical materials to be applicable as efficient broadband terahertz (THz) wave generators, low absorption with wide transparency in the THz frequency range is highly important. In this study, we report efficient organic THz wave generators, 2-(4-hydroxystyryl)-1-methylquinolinium 4-bromobenzenesulfonate (OHQ-BBS) single crystals. Interestingly, the OHQ-BBS crystals exhibit a wide molecular vibrational mode-free range in the THz frequency region from 1.7 to 5.1 THz with an absorption coefficient of <20 mm−1. By optical rectification employing 130 fs pump pulses at 1300 nm wavelength, the OHQ-BBS crystals generate extremely broad, dimple-free THz waves in the range of 1.2–5.5 THz. Additionally, a THz electric field that is 20 times higher than the field generated from the widely used ZnTe inorganic crystal is achieved. Therefore, the OHQ-BBS single crystals are highly promising materials for diverse THz photonic applications.
Modified equivalent circuit for coplanar dielectric barrier discharge considering undischarged areas
Authors: Cui Zhitong , Liu Qiaojue , Cai Zhikun , Wang Jieming , Wu Qunfang
Published: January 2023

Coplanar dielectric barrier discharge has a wide range of potential applications in the domains of material surface modification and other areas by producing a thin layer of diffuse plasma with high power density in the air. For a thorough examination of essential variables and discharge properties of coplanar dielectric barrier discharge plasma, an equivalent circuit model is essential. In this paper, a modified equivalent circuit for coplanar dielectric barrier discharge (CDBD) that took into account both the undischarged part and the parasitic capacitance was developed and discussed. The results showed that in the diffusion phase, the discharge area fraction grew quickly with voltage and caused a significant drop in plasma impedance and burning voltage. As the applied voltage increased, the discharge area fraction tended to saturate, the burning voltage slowly rose, and a lot of micro-discharges with greater diameters were present on the dielectric surface during the saturation phase.
Modeling and analysis of a metal rubber vibration isolation system considering the nonlinear stiffness characteristics
Authors: Liu Yujun , Liu Jing , Pan Guang , Huang Qiaogao
Published: January 2023

In this study, the complete design process of a metal rubber isolator using a numerical method applied in automobile underwater gliders (AUGs) is researched. A ring-like metal rubber isolator that has the potential to reduce the vibration of the AUGs is proposed. In the numerical design method, the equivalent cantilever beam model is used to identify the mechanical properties of the metal rubber isolator, whose accuracy is verified by experiment. The static stiffness and dynamic stiffness are gained through a fitting method, considering different mass loadings. Different material parameters of a metal rubber isolator, such as relative densities, wire diameters, wire spiral pitch diameters, and mass loading from the power system, greatly influence the mechanical properties and stiffness characteristic. The vibration isolation performance of a metal rubber isolator applied in the AUG is evaluated by a nonlinear single degree of freedom dynamic model, which is solved by the harmonic balance method. The linear stiffness component of the metal rubber isolator is the main influence factor for the vibration isolation performance. The nonlinear stiffness component could shift the isolation frequency.
Spontaneously excited longitudinal backward waves in dusty plasmas
Authors: Saitou Yoshifumi
Published: January 2023

A spontaneously excited longitudinal backward dust wave was experimentally examined. Dust particles were confined in a vertical glass cylinder. The spontaneously excited wave propagated downward. A dispersion relation was obtained by measuring the wavenumber and phase velocity. The dispersion relation showed that the wave consisted of two different modes, including a backward wave. The Trivelpiece–Gould (TG) mode was invoked as a dispersion relation to explain the backward wave, although the cyclotron angular frequency, ωc, appearing in the TG mode was replaced with ωa ∼ ωpd, where ωpd is the dust angular frequency. The experimental results were compared with the calculated dispersion relation, including the TG mode. The group velocity of the spontaneously excited backward wave is larger than the value predicted with the TG mode. It is necessary to explain the backward wave to modify the TG mode model or to construct a new model.
High-precision muography in archaeogeophysics: A case study on Xi’an defensive walls
Authors: Liu Guorui , Luo Xujia , Tian Heng , Yao Kaiqiang , Niu Feiyun , Jin Long , Gao Jinlei , Rong Jian , Fu Zhiqiang , Kang Youxin , Fu Yuanyong , Wu Chun , Gao Heng , Gong Jiangbo , Zhang Weixiong , Luo Xiaogang , Liu Chunxian , Tian Xiangsheng , Yu Minghai , Wu Feng , Chen Jingjing , Liu Juntao , Liu Zhiyi
Published: January 2023

Muography is a rapidly developing and non-destructive tomographic technology that uses cosmic ray muons. Due to the natural presence and deeper penetration of cosmic ray muons, scientists have performed various pioneer studies in fields, such as customs security, the internal imaging of volcanoes, scientific archaeology, and others. With unique advantages, muography has gained increasing attention from archaeologists as a novel and innovative tool to investigate large-scale archaeological sites. This approach may be especially helpful for identifying endangered cultural relics and monuments. In the work, we employ a compact, rugged, and portable muon imaging system, CORMIS (COsmic Ray Muon Imaging System), deployed at up to six measurement locations to perform a case study of three-dimensional muography in Xi’an city, China. Cultural cities, such as Xi’an, have long histories and could benefit from innovative techniques used to investigate, conserve, and protect large historical sites. In this paper, we present in detail a high resolution survey on a rampart of a Xi’an defensive wall in demand of urgent protection. The survey data are carefully processed with advanced statistical methods newly introduced in muography, and the results indicate density anomalies inside the rampart with unprecedented levels of precision. The density anomalies are potential safety hazards and need to be eliminated as soon as possible. The successful implementation of this survey significantly encourages more engagement on the tangible application of high-precision 3D muography in archaeological investigations and protection projects around the world.
Topological nature of the Parker magnetostatic theorem
Authors: Low B. C.
Published: January 2023

The two-plate initial boundary-value problem of Parker is reviewed, treating the relaxation of a 3D magnetic field prescribed with an arbitrary topology to a terminal force-free field in a cold, viscous, electrically perfect fluid conductor. Anchored by their foot-points at the perfectly conducting rigid plates, the relaxing field preserves its topology. The Parker magnetostatic theorem states that for most prescribed field topologies, the terminal field must embed current sheets. The elements of this theorem are reviewed and analyzed to relate this initial boundary-value problem to (i) the variational problem for a force-free field of a given topology and (ii) the direct construction of a force-free field in terms of its pair of Euler flux functions. New insights and understanding are presented on the theorem as the compelling basis of the Parker theory of solar coronal heating.
Different effects of external force fields on aging Lévy walk
Authors: Chen Yao , Wang Xudong
Published: January 2023

Aging phenomena have been observed in numerous physical systems. Many statistical quantities depend on the aging time ta for aging anomalous diffusion processes. This paper pays more attention to how an external force field affects the aging Lévy walk. Based on the Langevin picture of the Lévy walk and the generalized Green–Kubo formula, we investigate the quantities that include the ensemble- and time-averaged mean-squared displacements in both weak aging ta≪t and strong aging ta≫t cases and compare them to the ones in the absence of any force field. Two typical force fields, constant force F and time-dependent periodic force F(t)=f0sin⁡(ωt), are considered for comparison. The generalized Einstein relation is also discussed in the case with the constant force. We find that the constant force is the key to causing the aging phenomena and enhancing the diffusion behavior of the aging Lévy walk, while the time-dependent periodic force is not. The different effects of the two kinds of forces on the aging Lévy walk are verified by both theoretical analyses and numerical simulations.
The full viscous quantum hydrodynamic system in one dimensional space
Authors: Sun Wenlong , Li Yeping , Han Xiaoying
Published: January 2023

A viscous quantum hydrodynamic system for particle density, current density, energy density, and electrostatic potential, coupled with a Poisson equation, is studied in spatial one dimensional real line. The system is self-consistent in the sense that the electric field, which forms a forcing term in the momentum and energy equations, is determined by the coupled Poisson equation. First, the existence and uniqueness of the stationary solution is proved in an appropriate Sobolev space. Then, exponential stability of the stationary solution is established by constructing an a priori estimate. Since the techniques for classical hydrodynamic equations are not applicable here due to the quantum term, the existence of a local-in-time solution is obtained by showing the existence of local-in-time solutions of a reformulated system via the iteration method.
An integrated and scalable experimental system for nitrogen-vacancy ensemble magnetometry
Authors: Song Shupei , Li Xining , Zhu Xinyi , Chen Bao , Yu Zhifei , Xu Nanyang , Chen Bing
Published: January 2023

Nitrogen-vacancy (NV) centers in diamond are extremely promising solid-state spin quantum sensors for magnetic field in recent years. The rapid development of NV-ensemble magnetometry has put forward higher requirements for high-speed data acquisition, real-time signal processing and analyzing, etc. However, the existing commercial instruments are bulky and expensive, which brings extra complexity to the weak magnetic field detection experiment and hinders the practicality and miniaturization of NV-ensemble magnetometry. Here, we report on an integrated and scalable experimental system based on a field-programmable-gate-array (FPGA) chip assisted with high-speed peripherals for NV-ensemble magnetometry, which presents a compact and compatible design containing high-speed data acquisition, oscilloscopes, signal generator, spectrum analyzer, lock-in amplifier, proportional-integral-derivative feedback controller, etc. To verify its applicability and reliability in experiments, various applications, such as optical magnetic resonance detection, optical cavity locking, and lock-in NV magnetometry, are conducted. We further realize the pump-enhanced magnetometry based on NV center ensembles using the optical cavity. Through the flexible FPGA design approach, this self-developed device can also be conveniently extended into atomic magnetometer and other quantum systems.
The traceability method of electronic transformer calibrators based on time series-weighted correlation degree extension integrating Hilbert phase-shift
Authors: Chen Mianzhou , Li Hongbin , Du Yufei , Zhang Chuanji
Published: January 2023

The traceability method directly affects the reliability and accuracy of the measurement of electronic transformers. The stability and unreliable traceability performance of analog devices would affect the traditional analog differential method. Thus, we propose a digital differential method combining a time series-weighted correlation degree extension integrating Hilbert phase-shift of four-term continuous third-derivative Nuttall window function, effectively suppressing the end effect problem and realizing the high-precision addition of the differential. Results of simulation experiments showed that the differential’s deviation was <10−10, much less than that (1.32 × 10−4) due to the analog differential. The voltage and current ratio difference’s combined standard uncertainty was 5.01 × 10−5 and 5.08 × 10−5, respectively, and 0.1718′ in the phase error. Finally, an automatic traceability detection system was constructed. Compared with the traditional method, the accuracy and stability of the automatic system were better and could meet the traceability requirements for 0.05-accuracy electronic voltage transformer calibrator.
Generation of 2D and 3D acoustic lattices in midair using polygonal active diffraction gratings
Authors: Paez-Amaya Darby , Muelas-Hurtado Ruben D. , Ealo Joao L. , Volke-Sepúlveda Karen
Published: January 2023

This paper presents a method to generate two- and three-dimensional periodic or quasi-periodic acoustic lattices in air using polygonal active diffraction gratings. The radiated field depends on design parameters and is well predictable in terms of a superposition of oblique plane waves, with very good agreement with simulations and experiments. Our device represents a simple and efficient approach for producing acoustic lattices with attractive advantages, such as planar single-sided geometry, simple electronics, axial steering, and broadband operation. The design is scalable and compatible with other scientific applications, such as microfluidic platforms.
Advanced fiber in-coupling through nanoprinted axially symmetric structures
Authors: Yermakov Oleh , Zeisberger Matthias , Schneidewind Henrik , Kim Jisoo , Bogdanov Andrey , Kivshar Yuri , Schmidt Markus A.
Published: January 2023

Here, we introduce and demonstrate nanoprinted all-dielectric nanostructures located on fiber end faces as a novel concept for the efficient coupling of light into optical fibers, especially at multiple incidence angles and across large angular intervals. Taking advantage of the unique properties of the nanoprinting technology, such as flexibly varying the width, height, and gap distance of each individual element, we realize different polymeric axial-symmetric structures, such as double-pitch gratings and aperiodic arrays, placed on the facet of commercial step-index fibers. Of particular note is the aperiodic geometry, enabling an unprecedentedly high average coupling efficiency across the entire angular range up to 80°, outperforming regular gratings and especially bare fibers by orders of magnitude. The excellent agreement between simulation and experiment clearly demonstrates the quality of the fabricated structures and the high accuracy of the nanoprinting process. Our approach enables realizing highly integrated and ready-to-use fiber devices, defining a new class of compact, flexible, and practically relevant all-fiber devices beyond the state-of-art. Applications can be found in a variety of cutting-edge fields that require highly efficient light collection over selected angular intervals, such as endoscopy or quantum technologies. Furthermore, fiber functionalization through nanoprinting represents a promising approach for interfacing highly complex functional photonic structures with optical fibers.
Voltage-gated spin-orbit torque switching in IrMn-based perpendicular magnetic tunnel junctions
Authors: Lu Jiaqi , Li Weixiang , Liu Jiahao , Liu Zhaochun , Wang Yining , Jiang Congzheng , Du Jiabo , Lu Shiyang , Lei Na , Peng Shouzhong , Zhao Weisheng
Published: January 2023

In this work, IrMn-based perpendicular magnetic tunnel junctions (MTJs) are investigated. By inserting a thin W layer at an antiferromagnet/ferromagnet (AFM/FM) interface, we enhance the annealing temperature to 355 °C and obtain a high tunnel magnetoresistance ratio of 127%. Subsequently, field-free spin–orbit torque (SOT) switching of perpendicular MTJ is realized thanks to the in-plane exchange bias generated at the AFM/FM interface. Moreover, by applying a gate voltage, a coercive field is effectively decreased due to the voltage-controlled magnetic anisotropy (VCMA) effect. Finally, through the interplay of the SOT and VCMA effects, the critical switching current density is dramatically reduced by 73% (to 2.4 MA/cm2) and the total writing power consumption is decreased by 84% when a gate voltage of 0.76 V is applied. These findings pave the way for the practical applications of the IrMn-based perpendicular MTJs in low-power magnetic random-access memory.
Hybrid simulations of the decay of reconnected structures downstream of the bow shock
Authors: Gingell I. , Schwartz S. J. , Kucharek H. , Farrugia C. J. , Fryer L. J. , Plank J. , Trattner K. J.
Published: January 2023

Observations by Magnetospheric Multiscale have demonstrated that magnetic reconnection occurs at Earth's bow shock, typically at thin current sheets arising from plasma instabilities and turbulence in the shock transition region. Observational surveys of both the shock transition and the magnetosheath downstream suggest that the number of current sheets in these regions may not be strongly dependent on the shock Mach number MA or the angle between the upstream magnetic field and shock normal (θBn). This result is somewhat surprising given that quasi-parallel and high Mach number shocks tend to have a more disordered and non-stationary structure. In order to investigate how shock reconnection manifests across different parameters, we perform a series of hybrid (fluid electron, kinetic ion) particle-in-cell simulations across a range of Mach numbers and orientations. Given that hybrid simulations cannot resolve electron-scale current sheets and reconnection, these simulations isolate an ion-scale mechanism for shock reconnection driven by an ion–ion beam instability in the foot. We find that this mechanism is strongly constrained to quasi-parallel shocks across all simulated Mach numbers. By quantifying reconnection using the area occupied by plasma on closed magnetic field lines, we find the number of reconnecting structures and closed field area increase with MA and decrease with θBn in the upstream and ramp regions. Downstream of the shock, however, we find a similar result to observational surveys: within the subset of quasi-parallel shocks, the decay rate of the closed field area (and hence thin current sheets) is not strongly dependent on upstream shock parameters.
Atomistic understanding of the influences of defects on the spall damage of aluminum under multiple shock loadings
Authors: Zhou Tingting , Zhang Qian , Yin Jianwei , He Anmin , Wang Pei
Published: January 2023

The spall damage of solid single crystal Al with initial defects such as voids or He bubbles under multiple decaying shock loadings is studied by molecular dynamics simulations. After the first shock compression and release, plenty of sparse defects in the void collapsed regions and a few disordered atoms surrounding He bubbles are formed in the Al-void and Al–He samples, respectively. The spall mechanism for the Al-void sample is the nucleation–growth–coalescence of voids originated from the defects at the early stage of damage and from the regions without defects at the late stage. Under second shock loading, the first spall region is compressed and the compression extent is dependent on the shock intensity; however, the density after complete compression is lower than the initial value. Meanwhile, a new spall region is formed due to the interaction of the second incident rarefaction wave with the one reflected from the surface of the first spall region into the sample, when the shock intensity is relatively strong. The new spall region exhibits lower spall strength for the samples with initial defects than that for the perfect sample. Additionally, respallation occurs in the first spall region after compression under the strong second shock, its damage evolution is strongly influenced by the defects formed after compression, and the spall strength is much lower than that of first spallation. For the Al–He sample, the spall mechanism is always dominated by the expansion-merging of He bubbles, with the fastest damage development and the lowest spall strength.
A combined melt-stretching and quenching setup for experimental studies of polymer crystallization under complex flow-temperature environments
Authors: Li Hanchuan , Ye Qiuyang , Sun Jiahui , Cui Shanlin , Zhang Zhen , Liu Chuntai , Shen Changyu , Wang Zhen
Published: January 2023

A combined melt-stretching and quenching setup is designed and developed to allow experimental investigations of polymer crystallization under the complex flow-temperature environments comparable to those encountered in the actual industrial processing. The melt-stretching proceeds by two drums rotating in the opposite directions with simultaneous recording of a stress–strain curve, where the Hencky strain and strain rate (≤233 s−1) are adjustable over a large range. After stretching, liquid N2 is used as a cooling medium to quench the free-standing melt, which is sprayed directly to the deformed melt driven by an electric pump. To ensure a high cooling efficiency, a three-way solenoid valve is employed to execute a sequential control of the liquid N2 flow direction to reduce the boil-off of liquid N2 before entering the sample chamber. The melt cooling rate depends on the liquid N2 flow rate controlled by a flow valve, which is up to 221 °C/s when quenching the isotactic polypropylene (iPP) melt with a thickness of 0.28 mm at 150 °C. Two independent temperature control modules are designed to meet the requirements of different stages of melt-stretching and quenching. To verify the capability of the setup, we have performed the melt-stretching and quenching experiments on iPP samples. The setup is demonstrated to be a valuable new tool to study polymer crystallization under coupled flow-cooling fields.
Spectroscopic snapshot for neutral water nonamer (H2O)9: Adding a H2O onto a hydrogen bond-unbroken edge of (H2O)8
Authors: Zheng Huijun , Zhang Yang-Yang , Wang Tiantong , Jiang Shuai , Yan Wenhui , Wang Chong , Zhao Ya , Hu Han-Shi , Yang Jiayue , Zhang Weiqing , Wu Guorong , Dai Dongxu , Li Gang , Li Jun , Yang Xueming , Jiang Ling
Published: January 2023

Structural characterization of neutral water clusters is crucial to understanding the structures and properties of water, but it has been proven to be a challenging experimental target due to the difficulty in size selection. Here, we report the size-specific infrared spectra of confinement-free neutral water nonamer (H2O)9 based on threshold photoionization, using a tunable vacuum ultraviolet free-electron laser. Distinct OH stretch vibrational fundamentals in the 3200–3350 cm−1 region are observed, providing unique spectral signatures for the formation of an unprecedented (H2O)9 structure evolved by adding a ninth water molecule onto a hydrogen bond-unbroken edge of the (H2O)8 octamer with D2d symmetry. This nonamer structure coexists with the five previously identified structures that can be viewed as derived by inserting a ninth water molecule into a hydrogen bond-broken edge of the D2d/S4 octamer. These findings provide key microscopic information for systematic understanding of the formation and growth mechanism of dynamical hydrogen-bonding networks that are responsible for the structure and properties of condensed-phase water.
The effect of wave frequency drift on the electron nonlinear resonant interaction with whistler-mode waves
Authors: Artemyev Anton V. , Albert Jay M. , Neishtadt Anatoli I. , Mourenas Didier
Published: January 2023

Electron resonant interaction with electromagnetic whistler-mode waves plays a crucial role for electron flux dynamics in planetary magnetospheres. One of the most intense types of whistler-mode waves consists of chorus waves generated via nonlinear resonant interaction with hot anisotropic electrons and propagating with time-varying (drifting) wave frequency. Electron nonlinear resonant interactions with such waves in a dipole magnetic field are well described analytically within the Hamiltonian approach under the approximation of monochromatic waves (of constant frequency). This paper aims to generalize this description to waves with drifting frequency. We show how frequency drift modifies two main nonlinear resonant effects: phase trapping and phase bunching. The obtained results contribute to the development of the Hamiltonian approach for wave–particle resonant interactions.
Measured viscosity characteristics of Fe3O4 ferrofluid in magnetic and thermal fields
Authors: Li Wangxu , Li Zhenggui , Han Wei , Li Yibin , Yan Shengnan , Zhao Qin , Chen Fang
Published: January 2023

The rheological mechanisms governing the viscosity characteristics of nano-ferrofluids are very complicated; there is no universal theoretical treatment that explains the dependence of the ferrofluid viscosity on the flow, magnetic, and temperature fields. Thus, determining the viscosity characteristics of ferrofluids in various physical fields is of great theoretical and practical significance. This study explores experimentally the relationship between the ferrofluid viscosity and temperature, magnetic-field strength, and magnetic-field inclination. A special experimental bench on which the magnetic field and temperature can be precisely controlled is designed and constructed. It is found that the ferrofluid viscosity is negatively correlated with temperature. Increasing the percentage of the magnetic particles in the ferrofluid increases the viscosity at any given temperature. Ferrofluids are shown to exhibit the magnetic–viscosity phenomenon: under the action of a magnetic field, the viscosity increases until a magnetic viscosity saturation value is reached. Increasing the magnetic field inclination can aggravate the magnetic–viscosity phenomenon but does not change the saturation value. Contrary to the naïve Hall theory but in agreement with earlier phenomenological studies, the magneto-viscous effect is greater with horizontal than with vertical magnetic fields. Simultaneous exposure to temperature and magnetic fields is investigated; the two fields appear to act independently on the viscosity. The magnetic viscosity saturation value is not affected by temperatures in the range of 30–60 °C.