bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of particle mass inhomogeneity on the two-dimensional Rayleigh–Bénard system of Yukawa liquids: A molecular dynamics study
Authors: Kaur Pawandeep , Ganesh Rajaraman
Published: November 2021

The effect of particle mass inhomogeneity on the evolution of macroscale fluid flow in the Rayleigh–Bénard system of two-dimensional Yukawa liquids is studied using “first principles” classical molecular dynamics simulations. We find that Rayleigh–Bénard convection cells (RBCCs) formed in the quasi-steady-state become unstable at later times as a result of introducing a small fraction (≤2% of the total particles) of particle mass inhomogeneity in a Yukawa system made up of point particles of uniform charges. The unstable RBCCs, after passing through several intermediate states, give rise to a unidirectional shear flow in the direction perpendicular to the external gravity. Depending on the fraction and phase space of the particle mass inhomogeneity introduced in the system, the unidirectional shear flow further evolves to give shearless parallel flow. We use single or dual particle mass distributions of various forms, such as Gaussian distribution, Dirac-delta distribution, or a combination of both, around different mean values in order to introduce particle mass inhomogeneity. The role of system size on the emergence of various intermediate fluid flow states is also investigated. Furthermore, by introducing an inhomogeneity in charge commensurate with mass inhomogeneity, we demonstrate the robustness of our findings. Finally, for the case of decreasing correlation strength and for otherwise identical parameters, it is shown that the particle mass inhomogeneity fails to generate shear flows from RBCCs in 2D Yukawa liquids.
WSe2/Pd Schottky diode combining van der Waals integrated and evaporated metal contacts
Authors: Wu Hao , Yan Zhong , Xie Zhenda , Zhu Shining
Published: November 2021

Metal–semiconductor junctions are at the heart of modern electronics. Various two-dimensional materials (2D) based electronic devices have been reported. However, Ohmic contacts between evaporated metal contacts and semiconducting 2D materials are still hard to achieve. Thus, design and fabrication of Schottky diodes based on layered WSe2 remain challenging. Here, we report a doping-free strategy to achieve Ohmic contacts in WSe2 diodes via van der Waals (vdW) contacts. We designed and fabricated vertical WSe2/Pd Schottky diodes, in which Ohmic and Schottky junctions can be realized simultaneously via vdW contacts and evaporated contacts, respectively. The specific contact resistance of the vdW contact is about 74.5 kΩ·μm2. The Schottky diodes exhibit strong rectification behavior with rectification ratio up to 105.
Designing circle swimmers: Principles and strategies
Authors: Cao Zhiyu , Jiang Huijun , Hou Zhonghuai
Published: November 2021

Various microswimmers move along circles rather than straight lines due to their swimming mechanisms, body shapes, or hydrodynamic effects. In this paper, we adopt the concepts of stochastic thermodynamics to analyze circle swimmers confined to a two-dimensional plane and study the trade-off relations between various physical quantities, such as precision, energy cost, and rotational speed. Based on these findings, we predict principles and strategies for designing microswimmers of special optimized functions under limited energy resource conditions, which will bring new experimental inspiration for designing smart motors.
Experimental evaluation of the 2D non-classical ohmic transport model for electrons in the hollow cathode plume
Authors: Georgin Marcel P. , McDonald Michael S.
Published: November 2021

A generalized Ohm’s law, including nonclassical electron collisions, is evaluated with experimentally measured plasma properties to infer electron streamlines in a hollow cathode plume. The analysis of the transport equation shows that large radial electric fields are sustained in the plume, in qualitative agreement with earlier experimental work. Through Ohm’s law, these dominant radial forces result in a highly divergent electron flow field. The electron current density determined from this flow field is not divergence free, within the statistical experimental uncertainty (contradicting current conservation). Several possibilities for this unexpected finding are analyzed and ruled out as physically plausible explanations for our findings. Since the divergence of the current density cannot be accounted for within the existing framework for electron transport in the cathode plume, the underlying inertia-less assumption of Ohm’s law is revisited. An analysis of inertial forces shows that they are significant in the near plume region of the cathode, contradicting the initial assumption. It is suggested that electron inertia cannot be neglected in the near plume region and that including it may result in less divergent streamlines and the proper conservation of current.
Field-free programmable spin logics based on spin Hall effect
Authors: Zhao M. K. , Wan C. H. , Luo X. M. , Wang Y. Z. , Ma T. Y. , Yang W. L. , Zhang Y. , Yin L. , Yu G. Q. , Han X. F.
Published: November 2021

Spin logics provide a shortcut toward logic-in-memory architectures. Here, using a T-type magnetic stack with a perpendicular magnetic layer, an in-plane layer, and a spacing layer in between, we can switch both the in-plane and perpendicular layers and independently control their magnetization without an external magnetic field. By initializing magnetization of the in-plane layer, we can further control chirality (clockwise and counterclockwise) of the current-dependence of perpendicular magnetization. Based on these properties and the majority gate theory, we experimentally construct five Boolean logic gates in a single device in the desired field-free condition, which steps forward to practical spin–orbit torque logics.
Multiqubit entanglement and quantum phase gates with epsilon-near-zero plasmonic waveguides
Authors: Li Ying , Argyropoulos Christos
Published: November 2021

Multiqubit entanglement is extremely important to perform truly secure quantum optical communication and computing operations. However, the efficient generation of long-range entanglement over extended time periods between multiple qubits randomly distributed in a photonic system remains an outstanding challenge. This constraint is mainly due to the detrimental effects of decoherence and dephasing. To alleviate this issue, we present engineered epsilon-near-zero (ENZ) nanostructures that can maximize the coherence of light–matter interactions at room temperature. We investigate a practical ENZ plasmonic waveguide system, which simultaneously achieves multiqubit entanglement in elongated distances, extended time periods, and, even more importantly, independent of the emitters' positions. More specifically, we present efficient transient entanglement between three and four optical qubits mediated by ENZ with results that can be easily generalized to an arbitrary number of emitters. The entanglement between multiple qubits is characterized by computing the negativity metric applied to the proposed nanophotonic ENZ configuration. The ENZ response is found to be substantially advantageous to boost the coherence between multiple emitters compared to alternative plasmonic waveguide schemes. Finally, the super-radiance collective emission response at the ENZ resonance is utilized to design a high fidelity two-qubit quantum phase gate that can be used in various emerging quantum computing applications.
Cryo infrared spectroscopy of N2 adsorption onto bimetallic rhodium–iron clusters in isolation
Authors: Klein Matthias P. , Ehrhard Amelie A. , Huber Maximilian E. , Straßner Annika , Fries Daniela V. , Dillinger Sebastian , Mohrbach Jennifer , Niedner-Schatteburg Gereon
Published: November 2021

We investigated the N2 adsorption behavior of bimetallic rhodium–iron cluster cations [RhiFej(N2)m]+ by means of InfraRed MultiplePhotoDissociation (IR-MPD) spectroscopy in comparison with density functional theory (DFT) modeling. This approach allows us to refine our kinetic results [Ehrhard et al., J. Chem. Phys. (in press)] to enhance our conclusions. We focus on a selection of cluster adsorbate complexes within the ranges of i = j = 3–8 and m = 1–10. For i = j = 3, 4, DFT suggests alloy structures in the case of i = j = 4 of high (D2d) symmetry: Rh–Fe bonds are preferred instead of Fe–Fe bonds or Rh–Rh bonds. N2 adsorption and IR-MPD studies reveal strong evidence for preferential adsorption to Rh sites and mere secondary adsorption to Fe. In some cases, we observe adsorption isomers. With the help of modeling the cluster adsorbate complex [Rh3Fe3(N2)7]+, we find clear evidence that the position of IR bands allows for an element specific assignment of an adsorption site. We transfer these findings to the [Rh4Fe4(N2)m]+ cluster adsorbate complex where the first four N2 molecules are exclusively adsorbed to the Rh atoms. The spectra of the larger adsorbates reveal N2 adsorption onto the Fe atoms. Thus, the spectroscopic findings are well interpreted for the smaller clusters in terms of computed structures, and both compare well to those of our accompanying kinetic study [Ehrhard et al., J. Chem. Phys. (in press)]. In contrast to our previous studies of bare rhodium clusters, the present investigations do not provide any indication for a spin quench in [RhiFej(N2)m]+ upon stepwise N2 adsorption.
Ring population statistics in an ice lattice model
Authors: Khosravi Ali , Lasave Jorge , Koval Sergio , Tosatti Erio
Published: November 2021

We calculate the distribution probability of hexagonal six-site rings in the disordered state of a cubic or hexagonal ice lattice model with ice rules perfectly obeyed. The mean-field distribution obtained is in significant agreement with those, slightly different among them, obtained by Monte Carlo simulations of the cubic or hexagonal model. The results are discussed in connection with the equilibrium and non-equilibrium transition from disorder to ferroelectric proton order.
Nanosized and metastable molybdenum oxides as negative electrode materials for durable high-energy aqueous Li-ion batteries
Authors: Yun Jeongsik , Sagehashi Ryota , Sato Yoshihiko , Masuda Takuya , Hoshino Satoshi , Rajendra Hongahally Basappa , Okuno Kazuki , Hosoe Akihisa , Bandarenka Aliaksandr S. , Yabuuchi Naoaki
Published: November 2021

Significance

This study describes a high-energy and durable aqueous battery system with metastable and nanosized Mo-based oxides used as high-capacity negative electrodes. A wider electrochemical window is achieved with concentrated aqueous electrolytes through which highly reversible Li storage without the decomposition of water molecules is achieved for the Mo-based oxides. A full cell with an Mn-based oxide shows good capacity retention over 2,000 cycles. X-ray absorption spectroscopy reveals that the solid-state redox reaction of Mo ions reversibly proceeds in aqueous electrolytes for the metastable Mo oxide. This study opens a way to develop high-energy, durable, and safe batteries on the basis of metastable and nanosized oxides with aqueous electrolyte solutions.
Defective cytokinin signaling reprograms lipid and flavonoid gene-to-metabolite networks to mitigate high salinity in
Arabidopsis
Authors: Abdelrahman Mostafa , Nishiyama Rie , Tran Cuong Duy , Kusano Miyako , Nakabayashi Ryo , Okazaki Yozo , Matsuda Fumio , Chávez Montes Ricardo A. , Mostofa Mohammad Golam , Li Weiqiang , Watanabe Yasuko , Fukushima Atsushi , Tanaka Maho , Seki Motoaki , Saito Kazuki , Herrera-Estrella Luis , Tran Lam-Son Phan
Published: November 2021

Significance

The regulatory roles of cytokinin (CK) signaling on metabolic plasticity of plant response to salt stress remain widely unknown. A comprehensive metabolome and transcriptome analysis of CK-signaling–defective
Arabidopsis thaliana histidine-containing phosphotransfer protein ahp2,3,5
and type-B
Arabidopsis response regulator arr1,10,12
triple mutants under nonsaline and saline conditions revealed that CK signaling induces a reprogramming of gene-to-metabolite networks involved in
Arabidopsis
response to salinity. CK signaling modulates prestress and poststress accumulations of sugars, amino acids, and anthocyanins as well as membrane lipid reprogramming as an emerging mechanism of salinity adaptation in
Arabidopsis
. Our results provide insights into CK-signaling–mediated regulation of gene-to-metabolite networks in response to salt stress, enabling the efficient application of CK biology in stress tolerance-oriented plant biotechnology.
Molecular structure of an open human K
ATP
channel
Authors: Zhao Chen , MacKinnon Roderick
Published: November 2021

Significance

ATP-sensitive potassium channel (K
ATP
) modulates membrane excitability according to the intracellular metabolic state: a high ATP/ADP ratio increases excitability by closing the K
+
channel pore, while a low ATP/ADP ratio reduces excitability by opening it. Such intricate regulation is achieved by allowing ATP and ADP to act upon two different subunits in K
ATP
that exert opposing effects on the channel’s gate. Previous structural studies have focused on conformations of K
ATP
with a closed pore. This paper presents a structure of K
ATP
with an open pore and points to a specific mechanism of allosteric regulation.
On the origin of 2nd person prefix #tV- in Trans-Himalayan languages
Authors: Pons Marie-Caroline
Published: November 2021

Two 2nd person verbal indexation forms are reconstructed back to Proto-Trans-Himalayan (PTH): a suffix #-n(a)(Bauman 1975;DeLancey 1989,2014;H. Sun 1983,1995;van Driem 1993;Watters 2002), and a prefix #tV- (Watters 2002;Jacques 2012;DeLancey 2011a,2014). While #-n(a)is in paradigmatic distribution with other suffixal forms, the prefixal position of #tV-raises the question of its functional origin.

DeLancey (2011a,2014: 23) suggests hypothetically that #tV- finds its origin either in a non-finite nominalization or in an irrealis nominalization, “ideal for an impersonal 2nd person use: ‘One might [speak]’ rather than ‘You will [speak].’”

Through the comparison of cognatetV- possessive andtV- nominalizer prefixes found in rGyalrongic, Kuki-Naga (Ao), and Sinitic, I propose that 2nd person #tV- can be traced back to a nominal possessive modifier such asone’sorsomeone’s: aman-type of R-impersonals (Malchukov & Siewierska 2011). Spreading to verbs, #tV- was used as a nominalizer indexing the notional S or A argument. With nouns and verbs alike, the referent of the possessor, whether 1st, 2nd, or 3rd person, was specific (Siewierska 2011: 62), accessible in discourse, anaphorically or deictically, regardless of the presence of a coreferential overt noun-phrase. The prefix #tV- started to be used in particular to address 2nd person indirectly, a development likely triggered by pragmatic motivations, i.e. politeness, before being reanalyzed as a 2nd person indexation marker.
Epistemic calibration
Authors: Koskinen Emmi , Stevanovic Melisa
Published: November 2021

Sometimes a division has been made between expressions of knowledge and expressions of emotion, but in the actual instances of interaction, they are deeply intertwined. In this paper we investigate the relationship between these expressions through the notions of affiliation and epistemics. More specifically, we analyze the phenomenon of ‘epistemic calibration’ in response to tellings of personal experience, where recipients fine-tune the strength of their access claims and the degree of their generalizations to be in line with their epistemic statuses in relation to those of the tellers. Drawing on a dataset of Finnish quasi-natural conversations with neurotypical participants and participants diagnosed with Asperger syndrome, we explore how such calibration is done in practice. Our analysis points to different challenges in epistemic calibration, which, we argue, play an important role in influencing the hearing of these responses as less than fully affiliative.
An NR2F1-specific agonist suppresses metastasis by inducing cancer cell dormancy
Authors: Khalil Bassem D. , Sanchez Roberto , Rahman Tasrina , Rodriguez-Tirado Carolina , Moritsch Stefan , Martinez Alba Rodriguez , Miles Brett , Farias Eduardo , Mezei Mihaly , Nobre Ana Rita , Singh Deepak , Kale Nupura , Sproll Karl Christoph , Sosa Maria Soledad , Aguirre-Ghiso Julio A.
Published: November 2021

We describe the discovery of an agonist of the nuclear receptor NR2F1 that specifically activates dormancy programs in malignant cells. The agonist led to a self-regulated increase in NR2F1 mRNA and protein and downstream transcription of a novel dormancy program. This program led to growth arrest of an HNSCC PDX line, human cell lines, and patient-derived organoids in 3D cultures and in vivo. This effect was lost when NR2F1 was knocked out by CRISPR-Cas9. RNA sequencing revealed that agonist treatment induces transcriptional changes associated with inhibition of cell cycle progression and mTOR signaling, metastasis suppression, and induction of a neural crest lineage program. In mice, agonist treatment resulted in inhibition of lung HNSCC metastasis, even after cessation of the treatment, where disseminated tumor cells displayed an NR2F1hi/p27hi/Ki-67lo/p-S6lo phenotype and remained in a dormant single-cell state. Our work provides proof of principle supporting the use of NR2F1 agonists to induce dormancy as a therapeutic strategy to prevent metastasis.
Key comparison BIPM.RI(I)-K3 of the air-kerma standards of the ARPANSA, Australia, and the BIPM in medium-energy x-rays
Authors: Burns D T , Kessler C , Hanlon M , Bailey T , Oliver C , Butler D
Published: November 2021

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Subsequent comparison of measurements of neutron source emission rate (2016-17) - CCRI(III)-K9.AmBe.2
Authors: Roberts N J , Thiam C , Capogni M , Silvi L
Published: November 2021

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Entanglement between two gravitating universes
Authors: Balasubramanian Vijay , Kar Arjun , Ugajin Tomonori
Published: November 2021

We study two disjoint universes in an entangled pure state. When only one universe contains gravity, the path integral for the nth Rényi entropy includes a wormhole between the n copies of the gravitating universe, leading to a standard ‘island formula’ for entanglement entropy consistent with unitarity of quantum information. When both universes contain gravity, gravitational corrections to this configuration lead to a violation of unitarity. However, the path integral is now dominated by a novel wormhole with 2n boundaries connecting replica copies of both universes. The analytic continuation of this contribution involves a quotient by

Z

n

replica symmetry, giving a cylinder connecting the two universes. When entanglement is large, this configuration has an effective description as a ‘swap wormhole’, a geometry in which the boundaries of the two universes are glued together by a ‘swaperator’. This description allows precise computation of a generalized entropy-like formula for entanglement entropy. The quantum extremal surface computing the entropy lives on the Lorentzian continuation of the cylinder/swap wormhole, which has a connected Cauchy slice stretching between the universes—a realization of the ER = EPR idea. The new wormhole restores unitarity of quantum information.
A dielectrophoresis-based microfluidic chip for trapping circulating tumor cells using a porous membrane
Authors: Farasat Malihe , Chavoshi Seyede Maede , Bakhshi Atin , Valipour Aref , Badieirostami Majid
Published: November 2021

Circulating tumor cells (CTCs) have been widely considered as novel biomarkers for the clinical diagnosis of cancer. CTCs are the cells detached from the parent tumors and shed into the blood stream to initiate tumor metastasis. Although CTCs are rare, their detection in one’s blood sample is essential for cancer early diagnosis and for starting the treatment procedure. Here, we introduce a novel method for trapping CTCs using dielectrophores, which effectively employs pores of a replaceable porous membrane as CTC traps. The applied dielectrophoretic force efficiently traps and holds CTCs in a stable position and further enables us to perform various on-chip analysis with them. First, using finite element method, the performance of the system was simulated for different physical conditions. Then, the chip was fabricated and its trapping performance was experimentally validated. Cells were entered into the microchannel and trapped in the pores of a polydimethylsiloxane membrane. The proposed microfluidic chip is capable of detecting rare cells in a large cell population.
Entanglement and coherence in a hybrid Laguerre–Gaussian rotating cavity optomechanical system with two-level atoms
Authors: Singh S K , Peng Jia-Xin , Asjad Muhammad , Mazaheri M
Published: November 2021

We theoretically investigate quantum entanglement and coherence in a hybrid Laguerre–Gaussian rotating cavity optomechanical system with two-level atoms, where cavity and mechanical modes are coupled through the exchange of orbital angular momentum. Our study shows that the injection of atoms with a suitable choice of the physical parameters can significantly improve the degree of optomechanical entanglement in all aspects. In the study of quantum coherence research, we show more comprehensively the negative and positive effects of atoms on the coherence. The result obtained is that only when the atom is significantly off-resonant to driving field, the coupling strength in between the atoms and light field increases and the quantum coherence can be enhanced, otherwise it will reduce quantum coherence. In addition, the atomic decay suppresses quantum coherence phenomenon.
Determination of positive anode sheath in anodic carbon arc for synthesis of nanomaterials
Authors: Chopra N S , Raitses Y , Yatom S , Muñoz Burgos J M
Published: November 2021

In the atmospheric pressure anodic carbon arc, ablation of the anode serves as a feedstock of carbon for production of nanomaterials. It is known that the ablation of the graphite anode in this arc can have two distinctive modes with low and high ablation rates. The transition between these modes is governed by the power deposition at the arc attachment to the anode and depends on the gap between the anode and the cathode electrodes. Probe measurements combined with optical emission spectroscopy are used to analyze the voltage drop between the arc electrodes. These measurements corroborated previous predictions of a positive anode sheath (i.e. electron attracting sheath) in this arc, which appears in both low and high ablation modes. However, the positive anode sheath was determined to be ∼3–8 V, significantly larger than ∼0.5 V predicted by previous models. Thus, there are apparently other physical mechanisms not considered by these models that force the anode sheath to be electron attracting in both ablation regimes. Another key result is a relatively low electron temperature (∼0.6 eV) obtained from OES using a collisional radiative model. This result partially explains a higher arc voltage (∼20 V) required to sustain the arc current of 50–70 A than predicted by existing simulations of this discharge.
Recent advancements in flexible and wearable sensors for biomedical and healthcare applications
Authors: Wang Yan , Yang Ben , Hua Zhekun , Zhang Junyao , Guo Pu , Hao Dandan , Gao Yushan , Huang Jia
Published: November 2021

With the increasing awareness of personal health management in recent decades, various types of flexible and wearable body sensors have been developed. Thanks to the superiority of advanced wearable technologies, including miniaturization, portability, stretchability, comfort, intelligent human-machine interface, etc, flexible and wearable body sensors hold great promise for next generation biomedicine and healthcare applications. Unfortunately, the data precision, response speed, sensitivity and selectivity, durability, compatibility with flexible substrates, and preparation techniques still need to be enhanced and refined to meet the requirements of clinical evaluations or even commercialization. According to working principles, flexible and wearable sensing platforms can be roughly divided into four categories: physical sensors, chemical sensors, biosensors, and the combination of different types of sensors. Here, a brief review focused on the recent developments of these flexible and wearable sensors applied especially to biomedicine and healthcare is presented. In addition, the existing challenges and potential opportunities ahead in flexible and wearable sensor technologies are discussed. Finally, an outlook of wearable sensing platforms in biomedicine and healthcare is proposed. We hope this review can provide guidance for superior flexible and wearable sensing technologies in the future and can provide an outlook for commercial wearable sensors.
Cross-comparison of diagnostic and 0D modeling of a micro-hollow cathode discharge in the stationary regime in an Ar/N2 gas mixture
Authors: Remigy Alice , Kasri Salima , Darny Thibault , Kabbara Hiba , William Ludovic , Bauville Gérard , Gazeli Kristaq , Pasquiers Stéphane , Santos Sousa João , De Oliveira Nelson , Sadeghi Nader , Lombardi Guillaume , Lazzaroni Claudia
Published: November 2021

A micro-hollow cathode discharge (MHCD) operated in Ar/N2 gas mixture, working in the normal regime, was studied both experimentally and with a 0D (volume-averaged) model in this work. This source provides high electron densities (up to 1015 cm−3) at low injected power (1 W). To understand the mechanisms leading to the production of N atoms, the densities of electrons, N atoms and argon metastable atoms (Ar*) were monitored over a wide range of experimental conditions. Electrons, N atoms and Ar* densities were probed by means of optical emission spectroscopy, vacuum ultra violet Fourier transform spectroscopy and tunable diode laser absorption spectroscopy, respectively. Measurements showed that using a smaller hole diameter enables to work with less injected power, while increasing the power density inside the hole and, subsequently, increasing the densities of excited species. Varying the percentage of N2 in the gas mixture highlighted that, up to 80%, the density of N atoms increases although the dissociation rate drops. Looking at the processes involved in the production of N atoms with the help of the 0D model, we found that at very low N2 fraction, N atoms are mostly produced through dissociative electron-ion recombination. However, adding more N2 decreases drastically the electron density. The density of N atoms does not drop thanks to the contribution of Ar* atoms, which are the main species dissociating N2 between 5% and 55% of N2 in the gas mixture. A reasonable agreement is found between the experiments and the model results. This study shows that, with this MHCD, it is possible to significantly modify the production of N atoms when modifying the physical parameters, making it particularly relevant for applications requiring a N atoms source, such as nitride deposition.
Highly responsive multi-flow pattern generation by multi-electrode plasma actuator using a single power supply
Authors: Sugimoto Kosuke , Ogata Satoshi
Published: November 2021

A dielectric-barrier-discharge plasma actuator (DBD-PA) is an active flow-control device that uses ionic wind generated by electrohydrodynamic forces. A DBD-PA controls fluid motion and offers quick response without the need for moving parts. Previous studies have proposed methods for generating various flow patterns with a DBD-PA for fluid control. This paper presents a method for generating multiple flow patterns using a multi-electrode DBD-PA that is driven by a single-channel high-voltage power supply with a relay circuit. In contrast, conventional methods of realizing multiple flow patterns involve the use of a multi-channel power supply. Hence, they have the disadvantage of requiring a complicated power supply system. The proposed method succeeded in realizing several induced-flow modes involving the generation of a directionally controllable wall jet, various sizes of vortices, and an upward jet by altering the switching frequency and switching ratio. In addition, our experimental results indicate that the proposed method can control the flow pattern with a significantly short response time. The direction of the wall jet can be switched within tens to hundreds of milliseconds. Therefore, the proposed method combines simplicity and versatility and is expected to facilitate the realization of multifunctional active flow control in various flow fields, such as flow turbulent boundary layer control, thermal diffusion control, gas mixing, and flame-stability enhancement.
Plasmon modes in N-layer silicene structures
Authors: Men Nguyen Van
Published: November 2021

We investigate the plasmon properties in N-layer silicene systems consisting of N, up to 6, parallel single-layer silicene (SLS) under the application of an out-of-plane electric field, taking into account the spin–orbit coupling within the random-phase approximation. Numerical calculations demonstrate that N undamped plasmon modes, including one in-phase optical (Op) and (N − 1) out-of-phase acoustic (Ac) modes, continue mainly outside the single-particle excitation area of the system. As the number of layers increases, the frequencies of plasmonic collective excitations increase and can become much larger than that in SLS, more significant for high-frequency modes. The Op (Ac) plasmon mode(s) noticeably (slightly) decreases with the increase in the bandgap and weakly depends on the number of layers. We observe that the phase transition of the system weakly affects the plasmon properties, and as the bandgap caused by the spin–orbit coupling equal that caused by the external electric field, the plasmonic collective excitations and their broadening function in multilayer silicene behave similarly to those in multilayer gapless graphene structures. Our investigations show that plasmon curves in the system move toward that in SLS as the separation increases, and the impacts of this factor can be raised by a large number of layers in the system. Finally, we find that the imbalanced carrier density between silicene layers significantly decreases plasmon frequencies, depending on the number of layers.
Contact time of impacting droplets on a superhydrophobic surface with tunable curvature and groove orientation
Authors: Guo Chunfang , Liu Lei , Liu Changwan
Published: November 2021

Regulating the impact dynamics of water droplets on a solid surface is of great significance for some practical applications. In this study, the droplet impingement on a flexible superhydrophobic surface arrayed with micro-scale grooves was investigated experimentally. The surface was curved into cylindrical shapes with certain curvatures from two orthogonal directions, where axial and circumferential grooves were formed, respectively. The effects of curvature diameter and Weber number, as well as the orientation of grooves on droplet spreading and retracting dynamics were analyzed and explained. Results show that the circumferential grooves promote the spreading of a droplet in the azimuthal direction, where the droplet rebounds from the surface with a stretched shape. This mechanism further reduces the contact time of impacting droplets on the superhydrophobic surface compared to the other curving mode.
A review of radiation doses and associated parameters in Western Australian mining operations (2018–20)
Authors: Ralph Martin I , Cattani Marcus
Published: November 2021

In the 2019–20 reporting period, 19 mining operations in Western Australia were identified as having workers who were likely to be exposed to ionising radiation stemming from naturally occurring radioactive materials, 17 of which, known hereinafter as reporting entities (REs), were required to submit an annual report of the dose estimates of their workforce to the mining regulatory authority. In 2018 the International Commission for Radiological Protection published the revision of the dose coefficients (DCs) for occupational intakes of radionuclides of the uranium-238 and thorium-232 decay series, in ICRP-137 and ICRP-141. The 2019–20 annual reports are the first to apply the revised DCs to estimate worker doses. The mean effective dose (ED) reported by the 17 REs increased by 32.4% to 0.94 mSv in 2019–20 from 0.71 mSv reported in 2018–19, indicating that the mean ED is approaching the 1 mSv annual dose estimate at which regulatory intervention should be considered. The mean committed effective dose (CED) from inhalation of dusts containing long-lived alpha-emitting (LLα) nuclides has increased by 35% from 0.40 mSv in 2018–19 to 0.54 mSv in 2019–20. The maximum CED from LLα increased by 16.3% from 3.20 mSv in 2018–19 to 3.72 mSv in 2019–20. The authors consider that, in the absence of other explanations provided by the REs, the increase is largely attributable to the revised DC’s published in ICRP-137 and ICRP-141, but highlight that there are significant variations between REs that make a generalised conclusion problematic. The maximum reported ED in 2019–20 was 6.0 mSv, an increase of 36.4% from 2018 to 2019 (4.4 mSv). The 2019–20 reporting period is the first time in a decade in which mine worker EDs have been elevated to the point that EDs have exceeded 5 mSv, a level at which personal monitoring and additional institutional controls are required.
From coarse to fine: an augmented reality-based dynamic inspection method for visualized railway routing of freight cars
Authors: Yi Bing , Sun Renkai , Long Liu , Song Yongfeng , Zhang Yinggui
Published: November 2021

The dynamic inspection of railway routes for freight cars transporting cargo that is out of gauge is a challenge. One possible way is using the inspection frame installed in the inspection train to simulate the whole procedure for cargo transportation, which requires a lot of manpower and material resources as well as time. To overcome the above problem, this paper proposes an augmented reality-based dynamic inspection method for visualized railway routing of freight cars with out-of-gauge cargo. First, an envelope model of the dynamic moving train with out-of-gauge cargo is generated using the orbital spectrum of the railway, and the envelope model is matched with a piece of homemade calibration equipment located at the position of the railway that needs to be inspected. Then, the structure from motion algorithm is used to reconstruct the environment where the virtual envelope model occludes the buildings or equipment along the railway. Finally, the distance function is adopted to calculate the distance between the obstacle and the envelope of the out-of-gauge freight car, determining whether the freight car can pass a certain line. The experimental results show that the proposed method performs well for the route selection of out-of-gauge cargo transportation with low cost, high precision, and high efficiency. Moreover, the digital data of the environments along the railway and the envelope of the freight car can be reused, which will increase the digitalization and intelligence for route selection of out-of-gauge cargo transportation.
Regulating oxygen vacancies in Co3O4 by combining solution reduction and Ni2+ impregnation for oxygen evolution reaction
Authors: Tang Jinyu , Yao Lu , Ren Xiaoru , Shao Zhiyu , Cai Minmin , Gao Lu , Wu Xiaofeng
Published: November 2021

Oxygen vacancies are considered to be an important factor to influence the electronic structure and charge transport of electrocatalysts in the field of energy chemistry. Various strategies focused on oxygen vacancy engineering are proved to be efficient for further improving the electrocatalytic performance of Co3O4. Herein, an optimal Co3O4 with rich oxygen vacancies have been synthesized via a two-step process combining solution reduction and Ni2+ impregnation. The as-prepared electrocatalyst exhibits an enhanced oxygen evolution performance with the overpotential of 330 mV at the current density of 10 mA cm−2 in alkaline condition, which is 84 mV lower than that of pristine one. With the increasing of oxygen vacancies, the charge transfer efficiency and surface active area are relatively enhanced reflected by the Tafel slope and double-layer capacitance measurement. These results indicate that combination of solution reduction and heteroatom doping can be a valid way for efficient metal oxides-based electrocatalyst development by constructing higher concentration of oxygen vacancy.
Degradation performance and mechanism toward methyl orange via nanoporous copper powders fabricated by dealloying of ZrCuNiAl metallic glassy precursors
Authors: Gu Lingyu , Wang Shushen , Hui Xidong , Li Fudong , Lin Hengfu , Wu Kaiming
Published: November 2021

The catalyst of nanoporous Cu (NP-Cu) powders, with the chemical composition of Cu79.63Ni6.85O13.53 (at%), was successfully fabricated by dealloying of Zr–Cu–Ni–Al metallic glassy precursors. The as-prepared NP-Cu powders, co-existing with Cu2O phase on Cu ligament surface, had a three-dimensional network porous structure. The NP-Cu powders/H2O2 system showed superior catalytic degradation efficiency toward azo dyes in both acidic (pH 2) and neutral (pH 7) environments. Moreover, the cyclic tests indicated that this powder catalyst also exhibited good durability. A novel degradation mechanism of NP-Cu powders/H2O2 was proposed: the high degradation performance in acidic environment was mainly derived from heterogeneous reaction involved with a specific pathway related to Cu3+ to produce HO·, while in neutral environment it was primarily resulted from homogeneous reaction with the generation of HO· from the classical Cu-based Fenton-like process. This work indicates that the NP-Cu powders have great potential applications as catalysts for wastewater treatments.
Bottom-up nanoscale patterning and selective deposition on silicon nanowires
Authors: Mohabir Amar T , Aziz Daniel , Brummer Amy C , Taylor Kathleen E , Vogel Eric M , Filler Michael A
Published: November 2021

We demonstrate a bottom-up process for programming the deposition of coaxial thin films aligned to the underlying dopant profile of semiconductor nanowires. Our process synergistically combines three distinct methods—vapor–liquid–solid nanowire growth, selective coaxial lithography via etching of surfaces (SCALES), and area-selective atomic layer deposition (AS-ALD)—into a cohesive whole. Here, we study ZrO2 on Si nanowires as a model system. Si nanowires are first grown with an axially modulated n-Si/i-Si dopant profile. SCALES then yields coaxial poly(methyl methacrylate) (PMMA) masks on the n-Si regions. Subsequent AS-ALD of ZrO2 occurs on the exposed i-Si regions and not on those masked by PMMA. We show the spatial relationship between nanowire dopant profile, PMMA masks, and ZrO2 films, confirming the programmability of the process. The nanoscale resolution of our process coupled with the plethora of available AS-ALD chemistries promises a range of future opportunities to generate structurally complex nanoscale materials and electronic devices using entirely bottom-up methods.
Reduction of EUV resist damage by neutral beam etching
Authors: Kim Gyo Wun , Chang Won Jun , Kang Ji Eun , Kim Hee Ju , Yeom Geun Young
Published: November 2021

Even though EUV lithography has the advantage of implenting a finer pattern compared to ArF immersion lithography due to the use of 13.5 nm instead of 193 nm as the wavelength of the light source, due to the low energy of EUV light source, EUV resist has a thinner thickness than conventional ArF resist. EUV resist having such a thin thickness is more vulnerable to radiation damage received during the etching because of its low etch resistance and also tends to have a problem of low etch selectivity. In this study, the radiation damage to EUV resist during etching of hardmask materials such as Si3N4, SiO2, etc using CF4 gas was compared between neutral beam etching (NBE) and ion beam etching (IBE). When NBE was used, after the etching of 20 nm thick EUV resist, the line edge roughness increase and the critical dimension change of EUV resist were reduced by ∼1/3 and ∼1/2, respectively, compared to those by IBE. Also, at that EUV etch depth, the root mean square surface roughness value of EUV resist etched by NBE was ∼2/3 compared to that by IBE on the average. It was also confirmed that the etching selectivity between SiO2, Si3N4, etc and EUV resist was higher for NBE compared to IBE. The less damage to the EUV resist and the higher etch selectivity of materials such as Si3N4 and SiO2 over EUV resist for NBE compared to IBE are believed to be related to the no potential energy released by the neutralization of the ions during the etching by NBE.
Fatigue and its effect on the piezopotential properties of gallium nitride nanowires
Authors: Zhang Jin , Du Yao
Published: November 2021

The gallium nitride (GaN) nanowires (NWs) in piezotronic applications are usually under cyclic loading, which thus may inevitably suffer the mechanical fatigue. In this paper, the fatigue behaviours of defective GaN NWs are investigated by using molecular dynamics (MD) simulations. Our results show no significant changes in the molecular structures of GaN NWs until their final failure during the fatigue process. The final fracture occurring in the GaN NWs under fatigue loading is triggered by the crack that unusually initiates from the NW surface. The GaN NW with a smaller defect concentration or under the fatigue load with a smaller amplitude is found to possess a longer fatigue life. In addition, the ultimate fatigue strain of GaN NWs can be significantly increased by reducing the defect concentration of NWs. The material parameters including elastic constants, piezoelectric coefficients, and dielectric constants of GaN NWs in the fatigue test are evaluated through MD simulations, all of which are found to keep almost unchanged during the fatigue process. These material parameters together with the band gaps of GaN NWs extracted from first-principles calculations are employed in finite element calculations to investigate the piezopotential properties of GaN NWs under fatigue loading. No significant changes are found in the piezopotential properties of GaN NWs during the fatigue process, which indicates the long-term dynamic reliability of GaN NWs in piezotronic applications.
Citrate-capped gold nanoparticles with a diameter of 14 nm alter the expression of genes associated with stress response, cytoprotection and lipid metabolism in CaCo-2 cells
Authors: Wusu Adedoja Dorcas , Sibuyi Nicole Remaliah Samantha , Moabelo Koena Leah , Goboza Mediline , Madiehe Abram , Meyer Mervin
Published: November 2021

Advancements in nanotechnology have provided insight into the unique opportunities for the application of nanomaterials such as gold nanoparticles (AuNPs) in medicine due to their remarkable properties, which includes low toxicity, large surface area, and the ease of synthesis and conjugation to other molecules. Therefore, AuNPs are often preferred for bio-applications. Citrate-capped AuNPs (cAuNPs) have been reported to be non-cytotoxic and are used in numerous studies as drug delivery vehicles to treat various diseases. However, the limitations of bioassays often used to assess the toxicity of AuNPs have been well documented. Herein, we investigate the cytotoxicity of 14 nm cAuNPs in the human colorectal adenocarcinoma (Caco-2) cell line. Treatment conditions (i.e. dose and exposure time) that were established to be non-toxic to Caco-2 cells were used to investigate the effect of cAuNPs on the expression of a Qiagen panel of 86 genes involved in cytotoxicity. Out of 86 studied, 23 genes were differentially expressed. Genes involved in oxidative stress and antioxidant response, endoplasmic reticulum (ER) stress and unfolded protein response, heat shock response, and lipid metabolism were more affected than others. While low concentrations of 14 nm cAuNPs was not cytotoxic and did not cause cell death, cells treated with these nanoparticles experienced ER and oxidative stress, resulting in the activation of cytoprotective cellular processes. Additionally, several genes involved in lipid metabolism were also affected. Therefore, 14 nm cAuNPs can safely be used as drug delivery vehicles at low doses.
High-performance plasmonic lab-on-fiber sensing system constructed by universal polymer assisted transfer technique
Authors: Wang Guangrong , Wang Lei , Cheng Zhan , Chen Dan , Zhang Xuemin , Wang Tieqiang , Wang Qi , Fu Yu
Published: November 2021

Plasmonic lab-on-fiber (LOF) system has become an emerging sensing platform for the realization of miniaturized and portable plasmonic sensors. Herein, a facile and efficient polymer assisted transfer technique was reported for the preparation of plasmonic LOF systems. The proposed plasmonic LOF system was constructed through transferring plasmonic arrays to the end surface of optical fibers using polylactic acid as the sacrificial layer. The morphology of the transferred plasmonic arrays maintains excellent consistency with the original arrays. Importantly, the as-prepared plasmonic LOF system also possesses outstanding sensing performance in refractive index sensing and quantitative label-free biosensing applications. Additionally, the proposed polymer assisted transfer technique shows broad universality for various plasmonic arrays. Together with the above features, it is believed that the polymer assisted transfer technique will show great potential for the application of future plasmonic LOF systems.