bluuebunny/crossref_metadata_2025 huggingface dataset:
Palladium nanoparticles immobilized on COF-modified honeycomb chitosan microcapsules as catalysts for the Suzuki reaction andp-nitrophenol reduction
Authors: Wang Gongshu , Chen Zhangpei , Yan Guiyang , Hu Jianshe
Published: November 2022

CS/ZIF-8@COFa-4@Pd showed excellent activity in the Suzuki reaction and the reduction reaction ofp-NP.
Detection of salbutamol and enantioselective sensing ofl/d-lysine based on a cadmium-based coordination polymer
Authors: Jia Yuejiao , Li DeChao , Wu Nan , Su Shuai , Qie Shaowen , Hu Ming
Published: November 2022

An achiral CdII-based coordination polymer could sensitively recognize salbutamolviaa turn-on effect and distinguishl/d-lysine by different fluorescence responses.
High performance supercapacitive behaviors of oximes in a poly(aniline-co-pyrrole) based conducting polymer structure
Authors: Basili Taskın , Yildirim Kalyon Hilal , Gencten Metin , Macit Mustafa , Sahin Yucel
Published: November 2022

Novel oxime compounds and their complexes were synthesized and used as additives to poly(aniline-co-pyrrole) for the first time in the literature.
Ultrasensitive electrochemical immunoassay for screening the influenza A (H1N1) virus based on atomically Ru-dispersed nitrogen-doped carbon
Authors: Lin Jiancheng , Liu Jingjing , Xu Jin
Published: November 2022

An electrochemical immunoassay was designed based on an atomically Ru-dispersed nitrogen-doped carbon modified disposable SPCE for sensitive and specific screening of low-abundance influenza A (H1N1) virus with an innovative split-type strategy.
Supramolecular polymer network gels constructed by a pillararene-containing polymer and their applications in adhesion between semihard materials
Authors: Cheng Yujie , Lv Xiaoqing , Liang Bicong , Wei Xuehong , Wang Pi , Xia Danyu
Published: November 2022

Two types of supramolecular gels based on one kind of pillararene-containing polymer with multiple-stimuli-responsiveness were fabricated and showed strong adhesive strength in the semihard state.
Cobalt-electrocatalytic C–H hydroxyalkylation ofN-heteroarenes with trifluoromethyl ketones
Authors: He Tianyu , Liang Chaoqiang , Huang Shenlin
Published: November 2022

By merging paired electrolysis and cobalt catalysis, we have developed an electrochemical redox-neutral coupling for the synthesis ofN-heteroaryl trifluoromethyl carbinols from readily availableN-heteroarenes and trifluoromethyl ketones.
Microswimmers in vortices: dynamics and trapping
Authors: Tanasijević Ivan , Lauga Eric
Published: November 2022

We theoretically investigate the dynamics of model microswimmers in singular vortices, discover the existence of bounded orbits and use the model to successfully explain the previously observed depletion zone in bacterial suspensions.
Identification of ester-linked ubiquitylation sites during TLR7 signalling increases the number of inter-ubiquitin linkages from 8 to 12
Authors: McCrory Elisha H. , Akimov Vyacheslav , Cohen Philip , Blagoev Blagoy
Published: November 2022

The E3 ligase HOIL-1 forms ester bonds in vitro between ubiquitin and serine/threonine residues in proteins. Here, we exploit UbiSite technology to identify serine and threonine residues undergoing HOIL-1 catalysed ubiquitylation in macrophages stimulated with R848, an activator of the TLR7/8 heterodimer. We identify Thr12, Thr14, Ser20 and Thr22 of ubiquitin as amino acid residues forming ester bonds with the C-terminal carboxylate of another ubiquitin molecule. This increases from 8 to 12 the number of ubiquitin linkage types that are formed in cells. We also identify Ser175 of IRAK4, Ser136, Thr163 and Ser168 of IRAK2 and Thr141 of MyD88 as further sites of HOIL-1-catalysed ubiquitylation together with lysine residues in these proteins that also undergo R848-dependent ubiquitylation. These findings establish that the ubiquitin chains attached to components of myddosomes are initiated by both ester and isopeptide bonds. Ester bond formation takes place within the proline, serine, threonine-rich (PST) domains of IRAK2 and IRAK4 and the intermediate domain of MyD88. The ubiquitin molecules attached to Lys162, Thr163 and Ser168 of IRAK2 are attached to different IRAK2 molecules.
Polycystic ovary syndrome and iron overload: biochemical link and underlying mechanisms with potential novel therapeutic avenues
Authors: Mathew Marilyn , Sivaprakasam Sathish , Phy Jennifer L. , Bhutia Yangzom D. , Ganapathy Vadivel
Published: November 2022

Polycystic ovary syndrome (PCOS) is an endocrine and metabolic disorder in women with components of significant genetic predisposition and possibly multiple, but not yet clearly defined, triggers. This disorder shares several clinical features with hemochromatosis, a genetically defined inheritable disorder of iron overload, which includes insulin resistance, increased adiposity, diabetes, fatty liver, infertility, and hyperandrogenism. A notable difference between the two disorders, however, is that the clinical symptoms in PCOS appear at much younger age whereas they become evident in hemochromatosis at a much later age. Nonetheless, noticeable accumulation of excess iron in the body is a common finding in both disorders even at adolescence. Hepcidin, the iron-regulatory hormone secreted by the liver, is reduced in both disorders and consequently increases intestinal iron absorption. Recent studies have shown that gut bacteria play a critical role in the control of iron absorption in the intestine. As dysbiosis is a common finding between PCOS and hemochromatosis, changes in bacterial composition in the gut may represent another cause for iron overload in both diseases via increased iron absorption. This raises the possibility that strategies to prevent accumulation of excess iron with iron chelators and/or probiotics may have therapeutic potential in the management of polycystic ovary syndrome.
Strand 1A variant in neuroserpin shows increased aggregation and no loss of inhibition: implication in ameliorating polymerization to retain activity
Authors: Ansari Shoyab , Ahamad Shahzaib , Khan Abdul Burhan , Fatima Sana , Ahmad Tahif , Khan Yasmeen , Gupta Dinesh , Jairajpuri Mohamad Aman
Published: November 2022

Neuroserpin (NS) is predominantly expressed in the brain and is the primary inhibitor of tissue plasminogen activator (tPA). NS variants are associated with the neurogenerative disease termed familial encephalopathy with neuroserpin inclusion bodies (FENIB). The disease is characterized by variable age of onset and severity. The reactive center loop (RCL) insertion-based inhibitory mechanism of NS requires a coordinated conformational change leading to a shift in the strands of the β-sheet A and movement of helix F. Strand 1A is connected to the helix F at its C terminal end and with the strand 2A at its N terminal, both these domain move for accommodating the inserting loop; therefore, a variant that influences their movement may alter the inhibition rates. A molecular dynamic simulation analysis of a H138C NS variant from strand 1A showed a large decrease in conformational fluctuations as compared with wild-type NS. H138 was mutated, expressed, purified and a native-PAGE and transmission electron microscopy (TEM) analysis showed that this variant forms large molecular weight aggregates on a slight increase in temperature. However, a circular dichroism analysis showed its secondary structure to be largely conserved. Surprisingly, its tPA inhibition activity and complex formation remain unhindered even after the site-specific labeling of H138C with Alexa fluor C5 maleimide. Further, a helix F-strand 1A (W154C-H138C) double variant still shows appreciable inhibitory activity. Increasingly, it appears that aggregation and not loss of inhibition is the more likely cause of shutter region-based variants phenotypes, indicating that hindering polymer formation using small molecules may retain inhibitory activity in pathological variants of NS.
Implementation of Open Science Practices in Communication Sciences and Disorders Research With Black, Indigenous, and People of Color
Authors: Girolamo Teresa , Castro Nichol , Hendricks Alison Eisel , Ghali Samantha , Eigsti Inge-Marie
Published: November 2022

Purpose:

Open science that is truly accessible and transparent to all will enhance reproducibility. However, there are ethical and practical concerns in implementing open science practices, especially when working with populations who are systematically excluded from and marginalized in communication sciences and disorders (CSD) research, such as Black, Indigenous, and People of Color (BIPOC) from clinical populations. The purpose of this article was to discuss these concerns and present actionable steps to support open science in CSD research with BIPOC.

Conclusions:

In the movement toward open and reproducible science, the discipline of CSD must prioritize accessibility and transparency, in addition to the implementation of individual scientific practices. Such a focus requires building trust with BIPOC not only as research participants but also as valued leaders of the scientific community.
Metasurface‐inspired maintenance‐free Internet of things tags characterised in both frequency and time domains
Authors: Tashiro Masaya , Fathnan Ashif Aminulloh , Sugiura Yuta , Uchiyama Akira , Wakatsuchi Hiroki
Published: November 2022

The authors present metasurface‐inspired maintenance‐free Internet of things (IoT) tags that can be characterised not only by frequency‐domain profiles but also by time‐domain profiles. In particular, time‐domain characterisation is made possible by implementing the waveform‐selective mechanisms of recently developed circuit‐based metasurfaces that behave differently, even at the same frequency, in accordance with the pulse duration of the incident wave. The proposed designs are numerically and experimentally validated and potentially contribute to accommodating an increasing number of IoT tags within a single wireless network while reducing maintenance effort.
Effect of rotor magnetic isolation dimensions on no‐load performance of ultra‐low speed high torque spoke type permanent magnet motor
Authors: Sun Shaonan , Feng Guihong , Li Yan , Zhang Bingyi
Published: November 2022

This study investigates the effects of rotor magnetic isolation dimensions on the no‐load performance of ultra‐low speed high torque spoke type permanent magnet motor. The studied spoke type permanent magnet motor structures are shown, where the rotor magnetic isolation parts include a magnetic barrier near the air gap (MB‐NAG), a magnetic barrier near the magnetic isolation sleeve (MB‐NMIS), a magnetic isolation sleeve (MIS). The magnetic circuit model is performed and the finite element analysis method is used to analyse the no‐load performance. Through analysing no‐load performance with three MB‐NAG shapes, the way to narrow the optimise dimension range considering reducing the cogging torque and increasing the back‐EMF synchronously is concluded. The results with different MB‐NMIS and MIS dimensions show that: (a) the optimised MB‐NMIS dimensions can increase the back‐EMF with a thin MIS in a certain dimension range of MB‐NMIS, and (b) the increasing proportion of back‐EMF influenced by the MB‐NMIS is inversely proportional to the thickness of MIS. The feasibility and effectiveness of the proposed motor structure and conclusion are experimentally verified.
Digital twin‐based online tools for electric power communication system training: Online digital twin power communication system
Authors: Guan Shiqi , Hu Wenshan , Lei Zhongcheng , Zhou Hong
Published: November 2022

Electric power information has garnered particular interest in conventional electrical power systems because it plays a crucial role in the electric power industry. Additionally, electric power communication networks ensure the overall power system's reliability and safety. The concepts and techniques used in digital twin (DT)‐based online tools for electric power communication networks are introduced in this paper. Moreover, online DT tools are proposed as daily learning and training resources for both new staff and communication commissioners, which can be used for the internet and the company intranets. Users can control DT and physical equipment simultaneously, and device status can be seen in real time. The design, modelling, control principles, data collection, and visual display of the DT tools are all covered in this study. To validate the applicability of the proposed framework, a case study for optical fibre damage and the recovery process in a typical communication interruption malfunction is investigated. The research presented in this paper has the potential to provide useful tools and new paradigms for designing online DT training and education systems.
Diagnostik der Neuromyelitis-optica-Spektrum-Erkrankung (NMOSD) und der MOG-Antikörper-assoziierten Erkrankung (MOGAD)
Authors: Mewes Darius , Kuchling Joseph , Schindler Patrick , Khalil Ahmed Abdelrahim Ahmed , Jarius Sven , Paul Friedemann , Chien Claudia
Published: November 2022

Die Aquaporin-4-Antikörper-positive Neuromyelitis-optica-Spektrum-Erkrankung (engl. NMOSD) und die Myelin-Oligodendrozyten-Glykoprotein-Antikörper-assoziierte Erkrankung (engl. MOGAD) sind
Autoimmunerkrankungen des zentralen Nervensystems. Typische Erstmanifestationen sind bei Erwachsenen Optikusneuritis und Myelitis. Eine Beteiligung auch von Hirn und Hirnstamm, spätestens im
weiteren Verlauf, ist häufig. Während die NMOSD nahezu immer schubförmig verläuft, nimmt die MOGAD gelegentlich einen monophasischen Verlauf. Die Differenzialdiagnostik ist anspruchsvoll und
stützt sich auf u. a. auf radiologische und serologische Befunde. Die Abgrenzung von der häufigeren neuroinflammatorischen Erkrankung, Multiple Sklerose (MS), ist von erheblicher Bedeutung,
da sich Behandlung und langfristige Prognose von NMOSD, MOGAD und MS wesentlich unterscheiden. Die vielfältigen Symptome und die umfangreiche Diagnostik machen eine enge Zusammenarbeit
zwischen Ophthalmologie, Neurologie und Radiologie erforderlich. Dieser Artikel gibt einen Überblick über typische MRT-Befunde und die serologische Antikörperdiagnostik bei NMOSD und MOGAD.
Zwei illustrative Fallberichte aus der ärztlichen Praxis ergänzen die Darstellung.
Nanoparticles enhance delivery of treatments for prostate cancer
Authors: Johnson-Groh Mara
Published: November 2022

A combination of chemotherapy drugs delivered with nanoparticles showed success in treating prostate cancer in mice.
Electromagnetic total-f algorithm for gyrokinetic particle-in-cell simulations of boundary plasma in XGC
Authors: Hager Robert , Ku S. , Sharma A. Y. , Chang C. S. , Churchill R. M. , Scheinberg A.
Published: November 2022

The simplified δf mixed-variable/pullback electromagnetic simulation algorithm implemented in XGC for core plasma simulations by Cole et al. [Phys. Plasmas 28, 034501 (2021)] has been generalized to a total-f electromagnetic algorithm that can include, for the first time, the boundary plasma in diverted magnetic geometry with neutral particle recycling, turbulence, and neoclassical physics. The δf mixed-variable/pullback electromagnetic implementation is based on the pioneering work by Kleiber and Mischenko et al. [Kleiber et al., Phys. Plasmas 23, 032501 (2016); Mishchenko et al., Comput. Phys. Commun. 238, 194 (2019)]. An electromagnetic demonstration simulation is performed in a DIII-D-like, H-mode boundary plasma, including a corresponding comparative electrostatic simulation, which confirms that the electromagnetic simulation is necessary for a higher fidelity understanding of the electron particle and heat transport even at the low-β pedestal foot in the vicinity of the magnetic separatrix.
A review of design approaches for the implementation of low-frequency noise measurement systems
Authors: Scandurra G. , Ciofi C. , Smulko J. , Wen H.
Published: November 2022

Electronic noise has its roots in the fundamental physical interactions between matter and charged particles, carrying information about the phenomena that occur at the microscopic level. Therefore, Low-Frequency Noise Measurements (LFNM) are a well-established technique for the characterization of electron devices and materials and, compared to other techniques, they offer the advantage of being non-destructive and of providing a more detailed view of what happens in the matter during the manifestation of physical or chemical phenomena. For this reason, LFNM acquire particular importance in the modern technological era in which the introduction of new advanced materials requires in-depth and thorough characterization of the conduction phenomena. LFNM also find application in the field of sensors, as they allow to obtain more selective sensing systems even starting from conventional sensors. Performing meaningful noise measurements, however, requires that the background noise introduced by the measurement chain be much smaller than the noise to be detected and the instrumentation available on the market does not always meet the specifications required for reaching the ultimate sensitivity. Researchers willing to perform LFNM must often resort to the design of dedicated instrumentation in their own laboratories, but their cultural background does not necessarily include the ability to design, build, and test dedicated low noise instrumentation. In this review, we have tried to provide as much theoretical and practical guidelines as possible, so that even researchers with a limited background in electronic engineering can find useful information in developing or customizing low noise instrumentation.
Theoretical study of the interface engineering for H-diamond field effect transistors with h-BN gate dielectric and graphite gate
Authors: Gui Qingzhong , Wang Zhen , Cheng Chunmin , Zha Xiaoming , Robertson John , Liu Sheng , Zhang Zhaofu , Guo Yuzheng
Published: November 2022

Diamond has compelling advantages in power devices as an ultrawide-bandgap semiconductor. Using first-principles calculations, we systematically investigate the structural and electronic properties of hydrogen-terminated diamond (H-diamond) (111) van der Waals (vdW) heterostructures with graphite and hexagonal boron nitride (h-BN) layers. The graphite/H-diamond heterostructure forms a p-type ohmic contact and the p-type Schottky barrier decreases as the number of graphite layers increases. In contrast, the h-BN/H-diamond heterostructure exhibits semiconducting properties and a tunable type-II band alignment. Moreover, the charge transfer is concentrated at the interface with a large amount of charge accumulating on the C–H bonds on the H-diamond (111) surface, indicating the formation of a highly conductive two-dimensional hole gas (2DHG) layer. In a similar vein, the promising structural and electronic properties of graphite, h-BN, and H-diamond (111) in the graphite/h-BN/H-diamond (111) vdW heterostructure are well preserved upon their contact, while such heterostructure exhibits flexible band offset and Schottky contacts. These studies of interface engineering for H-diamond heterostructures are expected to advance the application of 2D materials in H-diamond field effect transistors, which is an important development in the design of surface transfer doping for 2DHG H-diamond devices.
Linear and nonlinear electro-elastic/electro-damping effect in ferroelectric ceramics
Authors: Xie Mingyu , Wang Qiangzhong , Li Faxin
Published: November 2022

The linear piezoelectric and nonlinear hysteresis behaviors of ferroelectrics are well-known and have been extensively studied. However, less attention has been paid to the variations of their mechanical properties under electric loading. In this work, using tube and cylinder specimens, three independent elastic coefficients and related internal frictions of PZT-5H ferroelectric ceramics are measured using our proposed modified piezoelectric ultrasonic composite oscillator technique (M-PUCOT) under an electric field E3 along the poling direction. Results show that under low electric fields, the elastic coefficients s11E, s66E and all internal frictions decrease linearly with E3, whereas s44E increases linearly with E3. Based on these linear results, two fifth-order tensors are defined, i.e., linear electro-elastic and linear electro-damping tensor with the reduced symbol of pikl and qikl, among which p311, p366, p344 and q311, q366, q344 are obtained in this work. When the applied electric field exceeds the coercive field (∼500 V/mm), nonlinear electro-elastic/electro-damping effect dominates, resulting in reversed butterfly curves for s11E and s66E and butterfly curves for s44E. As to the internal frictions under large bipolar fields, they seem to be a superposition of the reversed butterfly curves and a peak or valley at the coercive field. The linear electro-elastic effect in ferroelectric ceramics is caused by the reversible domain wall motions while the nonlinear electro-elastic effect is caused by non-180° domain switching and is well reproduced by a statistical model. The linear and nonlinear electro-elastic/electro-damping results obtained in this work offer new insight into the electromechanical coupling behavior of ferroelectric materials.
Dynamic properties of a self-replicating peptide network with inhibition
Authors: Gagnon Lucille G. , Czaikowski Maia E. , Peacock-López Enrique
Published: November 2022

In this paper, we report an open system consisting of three self-replicating peptides, in which peptide 1 inhibits the duplex template of peptide 2, peptide 2 inhibits duplex 3, and peptide 3 inhibits duplex 1 to complete the negative feedback loop. This interacting chemical network yields oscillations in the concentrations of all species over time and establishes a possible mechanism for pre-biotic chemical systems organization. The first focus of our analysis is the effect of altering rates of duplex formation and inhibition on oscillations. We then examine the autocatalytic rate constant in the symmetric and asymmetric cases.
Entanglement-enhanced optical atomic clocks
Authors: Colombo Simone , Pedrozo-Peñafiel Edwin , Vuletić Vladan
Published: November 2022

Recent developments in atomic physics have enabled the experimental generation of many-body entangled states to boost the performance of quantum sensors beyond the Standard Quantum Limit (SQL). This limit is imposed by the inherent projection noise of a quantum measurement. In this Perspective article, we describe the commonly used experimental methods to create many-body entangled states to operate quantum sensors beyond the SQL. In particular, we focus on the potential of applying quantum entanglement to state-of-the-art optical atomic clocks. In addition, we present recently developed time-reversal protocols that make use of complex states with high quantum Fisher information without requiring sub-SQL measurement resolution. We discuss the prospects for reaching near-Heisenberg limited quantum metrology based on such protocols.
Reduced graphene oxide grafted on p-Si photocathode as a multifunctional interlayer for enhanced solar hydrogen production
Authors: Shen Junxia , Wang Yongjie , Chen Cong , Wei Zhihe , Song Pengfei , Zou Shuai , Dong Wen , Su Xiaodong , Peng Yang , Fan Ronglei , Shen Mingrong
Published: November 2022

Photoelectrochemical (PEC) water splitting has been intensively studied as a sustainable approach to directly convert intermittent solar energy into storable hydrogen fuels. Its practical application, however, has been tethered by the trade-off between photoelectrode efficiency and stability. Herein, this work demonstrates a facile strategy to design highly efficient and stable Si photocathodes by utilizing the reduced graphene oxide (rGO) as a multifunctional interlayer to bridge the Pt catalysts and p-Si. The covalently grafted rGO layer forms a Schottky junction with p-Si allowing effective charge carrier extraction required for high efficiency, and, simultaneously, protects the Si surface and anchors Pt catalysts with enhanced stability. Consequently, the as-fabricated Pt/rGO/p-Si photocathodes exhibit an impressive PEC performance under simulated AM1.5G illumination with a high applied bias photon-to-current efficiency (ABPE) of 4.9% and stability of over 110 hours, outperforming the Pt/p-Si control sample and state-of-the-art p-Si based photocathodes. In summary, this work offers a viable path for developing high-performance solar-to-fuel conversion devices in the future.
High-performance a-ITZO TFTs with high bias stability enabled by self-aligned passivation using a-GaOx
Authors: Shi Yuhao , Shiah Yu-Shien , Sim Kihyung , Sasase Masato , Kim Junghwan , Hosono Hideo
Published: November 2022

Maintaining gate bias stability under negative bias stress (NBS) and positive bias stress (PBS) is a long-standing issue in amorphous oxide semiconductor thin-film transistors (TFTs). The passivation of the channel layer is crucial for improving device stability. We show that amorphous gallium oxide, which possesses appropriate energy levels (lower electron affinity and higher ionization potential) for indium–tin–zinc oxide (ITZO) TFTs, can be etched selectively by tetramethyl ammonium hydroxide-containing developers that enable self-alignment passivation, such as easy contact hole formation during the drain and source lithography processes. The self-aligned passivation process led to a-ITZO TFTs with high mobility (>50 cm2 V−1 s−1) and low subthreshold swing (<90 mV/dec). The threshold voltage shifts under NBS and PBS using a bias gate voltage of ±20 V for 1 h were −0.09 and 0.15 V, respectively. This passivation can obviate the need for the conventional CVD-derived passivation process by utilizing the DC sputtering of gallium oxide, which may reduce hydrogen issues.
Polarization analysis of terahertz emission from Bi-2212 cross-whisker intrinsic Josephson junction devices and their refractive index
Authors: Saito Y. , Kakeya I. , Takano Y.
Published: November 2022

Polarization analyses of the terahertz (THz) emission from Bi2Sr2CaCu2O8+δ whisker crystals used for superconducting THz emitters were conducted. The THz emission mode was estimated by a simple polarization measurement, and a simulation study was conducted to examine the validity of the polarization analysis. The refractive index of whisker crystals revealed through the polarization analyses was greater than that of bulk single crystals and agreed well with our previous THz emission report. The simulation study suggested the complex plasma excitation mode of the THz emission, and an interpretation of the refractive index obtained in this study is provided.
Three-dimensional numerical investigation on flow behaviors around a diversion dike
Authors: Gao Yangyang , Yang Haojun , Wang Lizhong , Zhao Ming
Published: November 2022

Three-dimensional numerical simulations of a flow past a non-submerged diversion dike are performed for various blockage ratios (1/6 ≤ β ≤ 1/3) and Froude numbers (0.152 ≤ Fr ≤ 0.253). The instantaneous and time-averaged flow characteristics, the evolution process of mixing layers, and the bed shear stress of the dike are analyzed. The blockage ratio β plays an important role in the momentum redistribution and turbulent kinetic energy of the diversion dike. As the blockage ratio increases, the flow velocity gradient and the vortex shedding frequency in the mixing layer significantly increase. The Froude number Fr has little effect on the flow field. A large recirculation zone is observed in the wake of the dike, and the recirculation length is more depended on the length of the dike rather than the Froude number. The bed shear stress around the dike increases significantly with the increase in the blockage ratio.
Drop impact dynamics on solid surfaces
Authors: Fang Wei , Zhang Kaixuan , Jiang Qi , Lv Cunjing , Sun Chao , Li Qunyang , Song Yanlin , Feng Xi-Qiao
Published: November 2022

Drop impact on solid surfaces widely occurs both in nature and engineering. In this Perspective, we review the recent advances in experimental, theoretical, and numerical investigations of drop impact dynamics on solid surfaces. The relevant theoretical models and numerical methods, such as the wetting transition models and the volume-of-fluid method, are briefly described. The influences of key factors on the drop impact dynamics, and the underlying mechanisms of forces and energies, are examined. Especially, we analyze the contact time for a drop impacting on a solid surface and discuss the effective strategies to tune the dynamic impact behavior. The design principles of functional surfaces and some typical applications are also discussed. Finally, Perspectives are given on future development of the drop impact dynamics and its potential applications in diverse engineering fields.
Investigation of film bulk acoustic resonators for sensing applications in liquid environment
Authors: Zhou Yu , Zou Yang , Gao Chao , Xu Qinwen , Tong Xin , Lin Binghui , Liu Yan , Soon Bo Woon , Cai Yao , Sun Chengliang
Published: November 2022

The thin film bulk acoustic resonator (FBAR) has emerged as a promising choice for liquid sensors because of its high frequency and sensitivity. To investigate the potential of FBAR devices working as the liquid sensors, we study the operating law of FBAR in liquid environments and explore the different loading effects of liquid on the shear mode and longitudinal mode. By analyzing the device and liquid interactions, we modify the Mason model of FBAR in the liquid environment. Subsequently, the influence of the piezoelectric film with different tilt angles and liquids on the characteristics of FBAR is discussed. We also prepared Sc0.2Al0.8N film-based FBAR to confirm the influence of different liquid environments on the resonant performances. The results show that the frequency drift of FBAR in the shear mode is related to density and viscosity of liquid, and the frequency drift of FBAR in the longitudinal mode is related to bulk modulus and density of liquid. The resonant frequency of FBAR in the shear mode is more sensitive with glycerol solution than that of FBAR in the longitudinal mode. This work can provide a research basis for the application of FBAR liquid sensors.
Molecular-kinetic study of multilayers gas-adsorption in a rarefied gas environment
Authors: Yu Hsinchen , Zhang Xiaoping
Published: November 2022

Gas adsorption on a solid surface commonly occurs in multiple layers. However, there has as yet been little attention paid to the molecular-kinetic processes of multilayer gas adsorption. The purpose of this study was, thus, to address this gap in the literature using simulations. The numerical approach presented herein is based on the Direct simulation Monte Carlo method and a two-way coupled-fluxes method. We found that “over-desorption” may exist in the re-balancing process of multilayer gas adsorption. In addition, the existence of transient behavior in the gas near the solid wall in the results of the two-way coupled simulations is also discussed. This work may aid the study of physical or chemical phenomena relating to a gas adsorbed onto a solid surface.
Impact of interfaces on magnetic properties of Gdx(Fe90Co10)1−x alloys
Authors: Bello Jean-Loïs , Lacour Daniel , Migot Sylvie , Ghanbaja Jaafar , Mangin Stéphane , Hehn Michel
Published: November 2022

A 5 nm thick ferrimagnetic film made of amorphous rare-earth transition-metal alloys Gdx(Fe90Co10)1-x was grown by physical vapor deposition. Its magnetic properties (coercivity, perpendicular magnetic anisotropy, and compensation composition at room temperature) were investigated for various buffer and capping layers in contact with a ferrimagnetic thin film. While Gdx(Fe90Co10)1-x appears to be amorphous for all the samples, it appears that (111) textured Cu is the best material to promote perpendicular magnetization. The large compensation composition change as a function of the magnetic film interface at room temperature is analyzed in terms of polarizability of the surrounding buffer and capping materials.
The effect of one-sided confinement on nappe oscillations in free falling liquid sheet
Authors: Bodhanwalla Hormuzd , Anghan Chetankumar , Banerjee Jyotirmay
Published: November 2022

A thin liquid sheet flowing under the effect of gravity, subjected to one-sided confinement, generates considerable oscillations. These oscillations (called nappe oscillations) are incidental to the interaction of the liquid sheet with the air enclosure present within the confinement. In this regard, a numerical study is presented here involving parametric investigations to establish the effect of the proximity of the liquid sheet to the wall and surface tension on the instability of the liquid sheet. The present study demonstrates that the confinement is responsible for the perturbations near the inlet of the sheet, which then propagates the sheet into the non-linear regime. Moreover, the study on the effect of the proximity of the wall to the liquid sheet depicts that the wall and liquid sheet interact with each other with pressure in the air cushion acting as a liaison between the two. The sheet closer to the wall evolves into the non-linear regime at a preceding time instant due to the higher rate of pressure rise in the air cushion. The liquid sheet oscillations are stabilized for higher values of the surface tension coefficient. The visualization of vortical structures reveals that the vortices are clustered in the confined space, ascending toward the inlet due to higher values of baroclinicity as the sheet gets closer to the wall. On the other hand, the vortices are sparsely distributed in the domain for higher values of the surface tension coefficient.
Mid-infrared timing jitter of superconducting nanowire single-photon detectors
Authors: Taylor Gregor G. , MacKenzie Ewan N. , Korzh Boris , Morozov Dmitry V. , Bumble Bruce , Beyer Andrew D. , Allmaras Jason P. , Shaw Matthew D. , Hadfield Robert H.
Published: November 2022

Detector timing jitter is a key parameter in advanced photon counting applications. Superconducting nanowire single-photon detectors offer the fastest timing jitter in the visible to telecom wavelength range and have demonstrated single-photon sensitivity in the mid-infrared spectral region. Here, we report on timing jitter in a NbTiN nanowire device from 1.56 to 3.5 μm wavelength, achieving a FWHM jitter from 13.2 to 30.3 ps. This study has implications for emerging time-correlated single-photon counting applications in the mid-infrared spectral region.
BULLKID: Monolithic array of particle absorbers sensed by kinetic inductance detectors
Authors: Cruciani A. , Bandiera L. , Calvo M. , Casali N. , Colantoni I. , Del Castello G. , del Gallo Roccagiovine M. , Delicato D. , Giammei M. , Guidi V. , Goupy J. , Pettinacci V. , Pettinari G. , Romagnoni M. , Tamisari M. , Mazzolari A. , Monfardini A. , Vignati M.
Published: November 2022

We introduce BULLKID, a phonon detector consisting of an array of dices acting as particle absorbers sensed by multiplexed Kinetic Inductance Detectors (KIDs). The dices are carved in a thick crystalline wafer and form a monolithic structure. The carvings leave a thin common disk intact in the wafer, acting both as holder for the dices and as substrate for the KID lithography. The prototype presented consists of an array of 64 dices of 5.4 × 5.4 × 5 mm3 carved in a 3˝ diameter, 5 mm thick silicon wafer, with a common disk of 0.5 mm thick, hosting a 60 nm patterned aluminum layer. The resulting array is highly segmented but avoids the use of dedicated holding structures for each unit. Despite the fact that the uniformity of the KID electrical response across the array needs optimization, the operation of eight units with similar features shows, on average, a baseline energy resolution of 26 ± 7 eV. This makes it a suitable detector for low-energy processes such as direct interactions of dark matter and coherent elastic neutrino-nucleus scattering.
Antiferromagnetic nodal loop and strain-controllable magnetic phase transition in monolayer MnAl
Authors: Huang Li , Zhu Jiaojiao , Wu Weikang , Cao Jin , Zhang Zeying , Jiao Yalong , Liu Yuan , Wang Liying , Yang Shengyuan A.
Published: November 2022

Exploring novel two-dimensional (2D) materials with intrinsic magnetism or topological band features is a focus of current research. Here, based on first-principles calculations, we study a 2D structure of MnAl, which, in the bulk form, is a well-known permanent magnet. We show that in 2D, MnAl can stabilize in a square lattice with single-atom thickness. The ground state is an antiferromagnet (AFM) with checkerboard type magnetic ordering and an estimated Néel temperature of 60 K. The state has large magnetic moment (∼4 μB per Mn) and sizable anisotropy (∼0.27 meV/f.u.), analogous to bulk MnAl. In the electronic band structure, the state exhibits a single type-I AFM nodal loop at the Fermi level, which is protected by mirror symmetry in the absence of spin–orbit coupling. Spin–orbit coupling opens only a small gap at the loop, preserving the band inversion feature. Furthermore, we show that a small strain (∼1%) can drive a magnetic phase transition from the checkerboard AFM to a stripe-type AFM state, accompanied by a significant change in the band structure. Our result offers an intriguing platform for exploring the interplay among magnetism, topology, and phase transitions in low dimensions.
Contribution of multiple plasmon scattering in low-angle electron diffraction investigated by energy-filtered atomically resolved 4D-STEM
Authors: Robert H. L. , Diederichs B. , Müller-Caspary K.
Published: November 2022

We report the influence of multiple plasmon losses on the dynamical diffraction of high-energy electrons, in a scanning transmission electron microscopy (STEM) study. Using an experimental setup enabling energy-filtered momentum-resolved STEM, it is shown that the successive excitation of up to five plasmons within the imaged material results in a subsequent and significant redistribution of low-angle intensity in diffraction space. An empirical approach, based on the convolution with a Lorentzian kernel, is shown to reliably model this redistribution in dependence of the energy-loss. Our study demonstrates that both the significant impact of inelastic scattering in low-angle diffraction at elevated specimen thickness and a rather straightforward model can be applied to mimic multiple plasmon scattering, which otherwise is currently not within reach for multislice simulations due to computational complexity.
Selective area epitaxy of degenerate n-GaN for HEMT ohmic contact by MOCVD
Authors: Qie Haoran , Liu Jianxun , li Qian , Sun Qian , Gao Hongwei , Sun Xiujian , Zhou Yu , Yang Hui
Published: November 2022

This Letter reports low-temperature (700 °C) growth of heavily Si-doped GaN (n++GaN) by metal-organic chemical vapor deposition with a resistivity as low as 1.9 × 10−4 Ω·cm and an atomically smooth surface. Indium adatoms added during the growth of n++GaN play an important role in improving both the surface morphology and free electron concentration. On the one hand, acting as surfactant, they greatly boost the adatoms surface mobility at low growth temperature and mitigate Si-induced anti-surfactant effect. On the other hand, they can effectively suppress the formation of compensating defects, thus contributing to an extremely high electron concentration of 2.8 × 1020 cm−3. This high-quality n++GaN was further applied to the realization of Ohmic contacts with an ultra-low contact resistance for AlGaN/GaN high electron mobility transistors. The carrier gas was carefully modulated for the selective area epitaxy (SAE) of n++GaN to facilitate the nucleation of GaN on the dielectric mask, which effectively suppressed the undesired mass transport and resulted in a uniform SAE of n++GaN in the recessed source/drain regions. A nearly defect-free interface between the n++GaN and two-dimensional electron gas channel has been also realized, and the resistance induced by the interface was only 0.03 Ω·mm. As a result, an ultra-low contact resistance of 0.07 Ω·mm has been realized. This work lays a solid foundation for further improving the performance of GaN-based RF and power devices.
Superoxide intermediate in the oxygen reduction on a zinc hydroxide model corrosion product
Authors: Nayak Simantini , Biedermann P. Ulrich , Erbe Andreas
Published: November 2022

The inhibition of the electrochemical oxygen reduction reaction (ORR) by zinc corrosion products plays an important role in the corrosion protection of galvanized steel. Hence, the electrocatalytic mechanism of the ORR on electrodeposited zinc hydroxide-based model corrosion products was investigated by in situ and operando attenuated total reflection infrared (ATR-IR) spectroscopy, supplemented by density functional theory (DFT) calculations. Model corrosion products containing flake-like crystalline Zn5(NO3)2(OH)8 were cathodically electrodeposited on germanium(100) electrodes from a zinc nitrate precursor electrolyte. Substantial amounts of the films are non-crystalline, and their surfaces predominantly consist of zinc oxide and hydroxide species, as evidenced by x-ray photoelectron spectroscopy. ATR-IR spectra show a peak at 1180 cm−1 during cathodic currents in O2-saturated NaClO4 solution. This peak is assigned to a surface-bound superoxide, the only ORR intermediate detected. Absorbance from the intermediate increases with increasing cathodic current, indicating an increase in surface concentration of superoxide intermediates at larger ORR current densities. The zinc hydroxide ages in the experiments, most likely by a transformation into zinc oxide, consistent with the observed decrease in absorbance over time of the OH bending mode of zinc hydroxide at 1380 cm−1. This aging is a time-dependent chemical process, implying that pure chemical aging is important in actual corrosion products as well. DFT calculations of adsorbed superoxide yield a Zn–O bond length similar to the bond length in Zn–O, thus enhancing superoxide interaction with undercoordinated tetrahedral Zn2+ sites on the surface. Thus, such active sites catalyze the first reduction step in the ORR.
Modulation of turbulence by dispersed charged particles in pipe flow
Authors: Zhao Yanlin , Liu Min , Li Jinzhui , Yan Yudong , Yao Jun
Published: November 2022

Turbulent gas–solid two-phase flow with electrostatic effects is studied. The turbulent pipe flow is treated using large-eddy simulation, while the particles are tracked using a Lagrangian approach. Simulations are carried out with one-way coupling, two-way coupling, and two-way coupling taking account of electrostatics, and the results are compared. The bulk Reynolds number is Reb = 44 000, and the Stokes number is St = 3.9 (dp = 5 μm). The results show that the maximum electrostatic field strength in the saturated state is found near, but not at, the wall. The electrostatic effect increases the particle concentration in the viscous sublayer (0 ≤ y+ ≤ 5) and the particle dispersion in the buffer layer (5 ≤ y+ ≤ 30). Owing to the electrostatic effect, the feedback effect of particles on the fluid is increased, which leads to increase in the average fluid velocity in the buffer layer and in the velocity fluctuations. In addition, the electrostatic effect is found to increase the turbulent kinetic energy near the wall, while this trend decreases with distance away from the wall. The areas of high- and low-speed streaks near the wall are increased by the electrostatic effect. Therefore, it can be concluded that electrostatics changes not only the particle behavior, but also the flow field.
Winter denning behaviour of striped skunks and interspecific den activity at their dens: implications for pathogen transmission
Authors: Amspacher Katelyn M. , Jiménez F. Agustín , Nielsen Clayton K.
Published: November 2022

Context Striped skunks (Mephitis mephitis) occur across a wide range of habitats in North America and co-occur with many wildlife that use similar denning structures. Few studies have quantified interspecific activity at striped skunk dens despite the concomitant implications for pathogen transmission due to direct and indirect contact at shared dens. Further, no studies have examined differences in striped skunk denning behaviour across an urban–rural gradient with various forms and degrees of human modification. Aims Our study described striped skunk denning behaviour in the lower Midwestern United States and assessed interspecific activity at dens. Methods We used radiotelemetry and camera traps to observe winter denning behaviour of radiocollared striped skunks and other sympatric species across an urban–rural gradient in southern Illinois, USA, during November–February 2018–2021. We examined correlations between striped skunks and other species captured in photos at dens. We tested for an effect of human modification on the number of dens used by striped skunks, and the effects of weather and landscape variables on striped skunk denning duration. Key results Striped skunks used 3–21 unique dens during a single winter and denned consecutively in one location for 2–59 days. All individuals were observed denning for ≥8 consecutive days. Three striped skunks participated in communal denning, and ≤3 striped skunks were observed at a den concurrently. Eleven mammalian species were observed at striped skunk dens, and other species were present in 35.3% of photos. Striped skunk presence at a den was positively associated with Virginia opossum (Didelphis virginiana) presence. Human modification had no significant effect on the number of dens used by a striped skunk. Human modification, distance to stream/shoreline, and mean daily temperature had significant negative effects on striped skunk denning duration. Conclusions We demonstrated that winter denning behaviour of striped skunks in southern Illinois, USA, fits into a latitudinal gradient of behaviour across North America, and dens are a shared resource where direct and indirect intraspecific and interspecific interactions occur. Implications Weather and landscape features influenced winter denning behaviour of striped skunks and ultimately pathogen transmission potential at dens, trends that could potentially be seen in other urban-adapted species.
Conformational dynamics of the Hsp70 chaperone throughout key steps of its ATPase cycle
Authors: Rohland Lukas , Kityk Roman , Smalinskaitė Luka , Mayer Matthias P.
Published: November 2022

The 70 kDa heat shock proteins (Hsp70s) are highly versatile molecular chaperones that assist in a wide variety of protein-folding processes. They exert their functions by continuously cycling between states of low and high affinity for client polypeptides, driven by ATP-binding and hydrolysis. This cycling is tuned by cochaperones and clients. Although structures for the high and low client affinity conformations of Hsp70 and Hsp70 domains in complex with various cochaperones and peptide clients are available, it is unclear how structural rearrangements in the presence of cochaperones and clients are orchestrated in space and time. Here, we report insights into the conformational dynamics of the prokaryotic model Hsp70 DnaK throughout its adenosine-5’-triphosphate hydrolysis (ATPase) cycle using proximity-induced fluorescence quenching. Our data suggest that ATP and cochaperone-induced structural rearrangements in DnaK occur in a sequential manner and resolve hitherto unpredicted cochaperone and client-induced structural rearrangements. Peptides induce large conformational changes in DnaK·ATP prior to ATP hydrolysis, whereas a protein client induces significantly smaller changes but is much more effective in stimulating ATP hydrolysis. Analysis of the enthalpies of activation for the ATP-induced opening of the DnaK lid in the presence of clients indicates that the lid does not exert an enthalpic pulling force onto bound clients, suggesting entropic pulling as a major mechanism for client unfolding. Our data reveal important insights into the mechanics, allostery, and dynamics of Hsp70 chaperones. We established a methodology for understanding the link between dynamics and function, Hsp70 diversity, and activity modulation.