bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal error estimates of a Crank–Nicolson finite element projection method for magnetohydrodynamic equations
Authors: Wang Cheng , Wang Jilu , Xia Zeyu , Xu Liwei
Published: February 2022

In this paper, we propose and analyze a fully discrete finite element projection method for the magnetohydrodynamic (MHD) equations. A modified Crank–Nicolson method and the Galerkin finite element method are used to discretize the model in time and space, respectively, and appropriate semi-implicit treatments are applied to the fluid convection term and two coupling terms. These semi-implicit approximations result in a linear system with variable coefficients for which the unique solvability can be proved theoretically. In addition, we use a second-order decoupling projection method of the Van Kan type [Van Kan, SIAM J. Sci. Statist. Comput. 7 (1986) 870–891] in the Stokes solver, which computes the intermediate velocity field based on the gradient of the pressure from the previous time level, and enforces the incompressibility constraint via the Helmholtz decomposition of the intermediate velocity field. The energy stability of the scheme is theoretically proved, in which the decoupled Stokes solver needs to be analyzed in details. Error estimates are proved in the discrete L∞(0, T; L2) norm for the proposed decoupled finite element projection scheme. Numerical examples are provided to illustrate the theoretical results.
Policy and Newly Confirmed Cases Universally Shape the Human Mobility during COVID-19
Authors: Li Kehan , Li Chao , Xiang Yinfeng , He Fengxiang , He Shibo , Chen Jiming , Fang Yi , Tao Dacheng , Sun Youxian
Published: February 2022

Understanding how human mobility pattern changes during the COVID-19 is of great importance in controlling the transmission of the pandemic. This pattern seems unpredictable due to the complex social contexts, individual behaviors, and limited data. We analyze the human mobility data of over 10 million smart devices in three major cities in China from January 2020 to March 2021. We find that the human mobility across multi-waves of epidemics presents a surprisingly similar pattern in these three cities, despite their significant gaps in geographic environments and epidemic intensities. In particular, we reveal that the COVID-19 policies and statistics (i.e., confirmed cases) dominate the human mobility during the pandemic. Thus, we propose a universal conditional generative adversarial network based framework to estimate human mobility, integrating COVID-19 statistics and policies via a gating fusion module. Extensive numerical experiments demonstrate that our model is generalizable for estimating human mobility dynamics accurately across three cities with multi-waves of COVID-19. Beyond, our model also allows policymakers to better evaluate the potential influences of various policies on human mobility and mitigate the unprecedented and disruptive pandemic.
Generation of random chordal graphs using subtrees of a tree
Authors: Şeker Oylum , Heggernes Pinar , Ekim Tinaz , Taşkın Z. Caner
Published: February 2022

Chordal graphs form one of the most studied graph classes. Several graph problems that are NP-hard in general become solvable in polynomial time on chordal graphs, whereas many others remain NP-hard. For a large group of problems among the latter, approximation algorithms, parameterized algorithms, and algorithms with moderately exponential or sub-exponential running time have been designed. Chordal graphs have also gained increasing interest during the recent years in the area of enumeration algorithms. Being able to test these algorithms on instances of chordal graphs is crucial for understanding the concepts of tractability of hard problems on graph classes. Unfortunately, only few published papers give algorithms for generating chordal graphs. Even in these papers, only very few methods aim for generating a large variety of chordal graphs. Surprisingly, none of these methods is directly based on the “intersection of subtrees of a tree” characterization of chordal graphs. In this paper, we give an algorithm for generating chordal graphs, based on the characterization that a graph is chordal if and only if it is the intersection graph of subtrees of a tree. Upon generating a random host tree, we give and test various methods that generate subtrees of the host tree. We compare our methods to one another and to existing ones for generating chordal graphs. Our experiments show that one of our methods is able to generate the largest variety of chordal graphs in terms of maximal clique sizes. Moreover, two of our subtree generation methods result in an overall complexity of our generation algorithm that is the best possible time complexity for a method generating the entire node set of subtrees in an “intersection of subtrees of a tree” representation. The instances corresponding to the results presented in this paper, and also a set of relatively small-sized instances are made available online.
New endoscopic capsule vs upper gastrointestinal endoscopy in preoperative work-up of obese candidate for bariatric surgery: Relevance of a pilot study in the COVID-19 era
Authors: Galloro Giuseppe , Musella Mario , Siciliano Saverio , Berardi Giovanna , Vitiello Antonio , Velotti Nunzio , Rizzello Fernando , Gionchetti Paolo , Calabrese Carlo
Published: February 2022

Background and study aims Obesity represents a major health concern; bariatric surgery is the most effective treatment reducing and maintaining weight loss. The role of a routine esophagogastroduodenoscopy (EGD) prior bariatric surgery is still debated. Moreover, in this scenario of COVID-19 pandemic, EGD is even more questionable due to the procedural risk of viral transmission. A new model of video-endoscopic capsule (VEC) recently has been introduced as a good alternative to the EGD. The aim of this study was to determine if this new capsule is an adequate diagnostic alternative to EGD in the work-up of patients selected for bariatric surgery, particularly in the setting of COVID-19.

Patients and methods From January to November 2020, 27 patients selected for bariatric surgery were enrolled in this pilot study to assess for noninferiority of VEC compared to EGD in detection of upper gastrointestinal disease.

Results VEC had sensitivity, specificity, and positive and negative predictive values in identification of significant lesions of 91.3 %, 83.33 %, 98.01 %, and 51.57 %, respectively, compared with EGD as the standard criterion. The accuracy was 90.51 % (95 % CI, 73.75 %-98.18 %) and the chi-square statistic is 0.1153 (P = 0.73).

Conclusions Our report confirms the diagnostic noninferiority of VEC in preoperative work-up of patients selected for bariatric surgery, compared to EGD. This is very important, particularly during the COVID-19 pandemic, given the high risk of contamination with EGD. Larger multicenter studies are required to confirm our preliminary results.
Stereoselective Domino Reactions in the Synthesis of Spiro Compounds
Authors: Benaglia Maurizio , Greco Sandro J. , Westphal Regina , Venturini Filho Eclair , Medici Fabrizio
Published: February 2022

This review summarizes the latest developments in asymmetric domino reactions, with the emphasis on the preparation of spiro compounds. Discussions on the stereoselectivity of the transformations, the reaction mechanisms, the rationalization of the stereochemical outcome, and the applications of domino reactions to the synthesis of biologically active molecules and natural products are included when appropriate.

1 Introduction

2 Asymmetric Domino Reactions

2.1 Domino Reactions Initiated by Michael Reactions

2.2 Domino Reactions Initiated by Mannich Reactions

2.3 Domino Reactions Initiated by Knoevenagel Reactions

2.4 Domino Reactions Initiated by Cycloaddition Reactions

2.5 Domino Reactions Initiated by Metal Insertion

2.6 Other Mechanisms

3 Conclusion
Synthetic Studies on Chromone Natural Products: The Preusso­chromones
Authors: Koert Ulrich , Beller Marc Paul
Published: February 2022

Total syntheses of preussochromones A, D, E, and F and structural revisions of preussochromones E and F are reviewed, demonstrating the use of α-keto esters and α,β-diketo esters as valuable reactants in stereoselective cyclization reactions in total synthesis.

1 Introduction

2 The Route to Preussochromone D

3 Synthesis and Structural Revision of Preussochromones E and F

4 Total Synthesis of Preussochromone A

5 Conclusion
Nonsurgical Rhinoplasty: Long-Term Follow-Up of High G′ HA Nasal Injections
Authors: Bertossi Dario , Magagnotto Nicola , Chirumbolo Salvatore , D'Souza Alwyn , Nocini Riccardo
Published: February 2022

Rhinoplasty is one of the most requested aesthetic procedures performed by plastic surgeons world-wide and nonsurgical rhinoplasty is becoming the gold standard in aesthetic nasal treatment. Follow-up clinical examinations were performed on all 107 patients, being a safe and predictable technique with a high degree of satisfaction for the patients. Nonsurgical rhinoplasty using hyaluronic acid is an effective, fast, and safe nasal reshaping procedure with a high degree of patient satisfaction. Generally, due to the gradual reabsorption of the filler, the results last up to 8 to 12 months after treatment, making it a valid minimally invasive alternative to surgical rhinoplasty. Consequently, to maintain the effects it is necessary to repeat the treatment once a year.
The Effect of Renting in Cropland on Livelihood Choices and Agricultural Commercialization: A Case Study from Rural Vietnam
Authors: Schulte Oliver , Nguyen Trung Thanh , Grote Ulrike
Published: February 2022

This paper investigates the role of land rental markets in livelihood choices using data from 792 farming households in rural Vietnam. First, we cluster households according to livelihood strategies and estimate the determinants of the respective decision. In a second step, we analyze the contribution of rented land in linking smallholders to output markets. Our results suggest that rented land can provide smallholders with an opportunity to increase their agricultural activities and avoid resorting to less remunerative activities such as agricultural wage labor. Moreover, rented crop area increases the probability of market participation as well as the quantity of sales. Our results point to the need for a further liberalization of land rental markets specifically targeted at households that have been excluded from more remunerative livelihood strategies previously. Supporting these households to have access to the assets required to cultivate the additional area is thus recommended.
Effects of anisotropic surface drift diffusion on the strained heteroepitaxial nanoislands subjected to electromigration stressing
Authors: Ogurtani Tarik Omer , Celik Aytac , Oren Ersin Emre
Published: February 2022

A systematic study based on self-consistent dynamical simulations is presented for the morphological evolutionary behavior of an isolated thin Ge/Si nanoisland (quantum dot) on a rigid substrate exposed to electromigration forces. This morphological evolution is basically induced by the anisotropic surface drift diffusion, driven by the capillary forces, the lattice mismatch stresses, and the wetting potential. In this study, we have mainly focused on the size and shape development kinetics of quantum dots, known as the “Stranski–Krastanov” (SK) morphology, influenced by applied electromigration stresses. Emphasis is given to the effects of rotational symmetry associated with the anisotropic diffusivity in 2D space (i.e., quantum wires in 3D). The pointed bullet-shaped “Stranski–Krastanov” islands with high aspect ratios, ξ = 0.77, are formed at the cathode edge, while the whole nanoisland slightly creeps out of the initial computational domain. The favorable configuration of the Ge20/Si80 alloy test module, which resulted in ζ = 0.37 enhancement in the contour surface area, has a dome shape attached to the [010] top surface of the Si substrate with a zone axis of {010}/⟨001⟩. The anisotropic surface diffusion dyadic has a fourfold rotational symmetry axis [001] lying on the (001) plane of the Si substrate, and its major axis is tilted at about ϕ = 45° from the applied electrostatic field extended along the longitudinal axis [100] of the substrate. This particular experiment resulted in a SK singlet peak with a small satellite with a very small aspect ratio of ≅0.2 that may be appropriate for the conception of quantum optoelectronic devices or inter-band structures to generate photoelectrons having large energy spectra, thereby increasing the efficiency of photovoltaics exposed to solar radiations.
Minimal mechanism for cyclic templating of length-controlled copolymers under isothermal conditions
Authors: Juritz Jordan , Poulton Jenny M. , Ouldridge Thomas E.
Published: February 2022

The production of sequence-specific copolymers using copolymer templates is fundamental to the synthesis of complex biological molecules and is a promising framework for the synthesis of synthetic chemical complexes. Unlike the superficially similar process of self-assembly, however, the development of synthetic systems that implement templated copying of copolymers under constant environmental conditions has been challenging. The main difficulty has been overcoming product inhibition or the tendency of products to adhere strongly to their templates—an effect that gets exponentially stronger with the template length. We develop coarse-grained models of copolymerization on a finite-length template and analyze them through stochastic simulation. We use these models first to demonstrate that product inhibition prevents reliable template copying and then ask how this problem can be overcome to achieve cyclic production of polymer copies of the right length and sequence in an autonomous and chemically driven context. We find that a simple addition to the model is sufficient to generate far longer polymer products that initially form on, and then separate from, the template. In this approach, some of the free energy of polymerization is diverted into disrupting copy–template bonds behind the leading edge of the growing copy copolymer. By additionally weakening the final copy–template bond at the end of the template, the model predicts that reliable copying with a high yield of full-length, sequence-matched products is possible over large ranges of parameter space, opening the way to the engineering of synthetic copying systems that operate autonomously.
Photoassisted ionization spectroscopy of few implanted bismuth orbitals in a silicon-on-insulator device
Authors: Stockbridge K. , Deßmann N. , Eless V. , Peach T. , Murdin B. N. , Clowes S. K.
Published: February 2022

The electrically detected orbital spectrum of a mesoscopic silicon device containing a small number of donors has been investigated. The device was fabricated on silicon-on-insulator with an optically active channel containing 6×105 substitutional bismuth centers introduced by ion implantation. The 1s(A1)→2p± orbital transition at the energy associated with isolated bismuth donors was detected via a change in photocurrent when illuminated by THz light from a free electron laser. The spectral dependence on bias, temperature, and laser intensity is explored to determine optimum conditions for detecting orbital transitions in smaller devices with fewer donors. These results suggest that photo-induced impact ionization can offer a route for the spectroscopic detection of few impurities providing a useful tool for the development of solid-state quantum technologies.
Computer-aided characterization of ferroelectric phase transitions and domain structures using polarizing light microscopy
Authors: Fan Jinhui , Lu Xiaoyan , Cao Wenwu
Published: February 2022

Optical microscopy is an essential characterization technique that is used as an initial step in the study of domain structures and phase transitions of ferroelectric materials. Image analysis aided by advanced computer algorithms is urgently required to enable an improved accuracy and higher efficiency of data processing. In this study, an automatic full-angle light intensity detection algorithm is developed to study polarizing light microscopy images of domain structures and the phase evolution process is decoded using the scale invariant feature transform method. This data processing algorithm is then used to characterize the phase transition process in relaxor ferroelectric PMN-0.29PT single crystals with complex domain structures. An emerging in-plane tetragonal phase is tracked during the rhombohedral (R) to tetragonal (T) phase transition, which is associated with peaks present in the temperature-dependent dielectric curve. Compared to the traditional polarizing light microscopy characterization method, this computer-aided algorithm enables a quicker and more informative analysis of domain evolutions in ferroelectric single crystals.
Effects of oblique irradiation on the onset of phototactic bioconvection
Authors: Panda M. K. , Sharma Preeti , Kumar Sandeep
Published: February 2022

The linear stability of a suspension of phototactic algae is investigated numerically with particular emphasis on the effects of angle of incidence of the illuminating oblique collimated irradiation. The solutions show a transition of the most unstable mode from stationary to overstable state or vice versa for certain parameters at the variation in angle of incidence. Furthermore, a transition from mode 2 to mode 1 instability is observed at the variation of angle of incidence for some parameter values. Oscillatory instabilities are also frequently observed in the rigid upper surface case at the increment in angle of incidence.
Double-probe atomic force microscopy for observing spatiotemporal dynamics in a photochromic thin film
Authors: Suzui Hirotsugu , Uchiyama Kazuharu , Takase Keito , Nakagomi Ryo , Kono Luna , Uchida Kingo , Chauvet Nicolas , Horisaki Ryoichi , Hori Hirokazu , Naruse Makoto
Published: February 2022

Photochromic diarylethenes undergo reversible isomerization upon alternate irradiation with ultraviolet and visible light, having excellent thermal stability and durability. Thus, in combination with localized light, they are expected to exhibit intelligent functions based on light–matter composite systems at the nanometer-scale. In previous work, the formation of a clear open-ring/closed-ring boundary was observed on the surface of photochromic diarylethene thin-film crystals by simultaneously irradiating visible and ultraviolet light. To examine dynamic processes of the boundary formation, we developed a multi-probe atomic force microscope allowing simultaneous and continuous observations at different spatial positions. In this study, we developed atomic force microscopy containing two independent probe tips that allow simultaneous observation at spatially different positions. We used a unique method to control two probes in close proximity to achieve measurements at arbitrary positions. We have correlated the structural changes on the surface of photochromic thin films with the movement of the phase boundary at the crystal surface caused by photoisomerization under simultaneous broad visible and ultraviolet light irradiation. We also measured inhomogeneous expansion of nanometer-scale photoisomerizations due to local photoexcitation. This study paves the way for the elucidation of phenomena in the dynamic optical processes of crystals and for understanding versatile spatiotemporal dynamics in two- and three-dimensional optoelectronic structures within a nanometer scale.
Atomic-scale insights into the colossal barocaloric effects of neopentyl glycol plastic crystals
Authors: Li Fangbiao , Li Min , Niu Chang , Wang Hui
Published: February 2022

Neopentyl glycol has become an important candidate material for solid-state refrigeration in the future because of its environmental protection, high energy efficiency, high stability, and economy. However, the complete micro-dynamic mechanism remains to be established, which restricts its further applications. In this work, we investigate one representative material-plastic crystal neopentyl glycol (NPG) by means of large-scale molecular dynamics simulation. It is found that NPG exhibits colossal barocaloric effects (CBCEs) with high isothermal entropy changes and potentially large adiabatic temperature changes, which closely relates to the reversible order disorder change in NPG's molecular orientation, in which the non-bond interaction between molecules plays a key role. Further analysis of orientational dynamics and hydrogen bond energy during phase transition along with pressure dependent thermal conductivity sheds light on the underlying microscopic mechanism. Our work reveals the molecular mechanism of CBCEs in NPG as a prototypical plastic crystal, providing valuable insight into achieving practical caloric materials in future cooling technology.
Modulation of spin Seebeck effect by hydrogenation
Authors: Ogata K. , Kikkawa T. , Saitoh E. , Shiomi Y.
Published: February 2022

We demonstrate the modulation of spin Seebeck effect (SSE) by hydrogenation in Pd/YIG bilayers. In the presence of 3% hydrogen gas, SSE voltage decreases by more than 50% from the magnitude observed in pure Ar gas. The modulation of the SSE voltage is reversible, but the recovery of the SSE voltage to the prehydrogenation value takes a few days because of a long time constant of hydrogen desorption. We also demonstrate that the spin Hall magnetoresistance of the identical sample reduces significantly with hydrogen exposure, supporting that the observed modulation of spin current signals originates from hydrogenation of Pd/YIG.
Variations in leaf and stem traits across two elevations in subtropical forests
Authors: Zhu Liwei , Zhang Yaxing , Ye Huiying , Li Yanqiong , Hu Weiting , Du Jie , Zhao Ping
Published: February 2022

Understanding the variations in plant traits across elevations may provide valuable insights into the species structure and function of forests and their responses to climate change. To explore the patterns of trait variation across elevations, we analysed 14 leaf and stem traits associated with resource acquisition and stress tolerance in Schima superba Gardner & Champion, Castanopsis chinensis (Sprengel) Hance, and Pinus massoniana Lambert trees at two elevations in a subtropical forest in southern China. Wood density increased, whereas crown width, leaf water potential at 0700 hours (ΨL-0700), and leaf δ18O decreased in high-elevation plants. Vessel diameter, daily maximum sap flux density, leaf δ13C, and leaf C and N concentrations per unit mass were comparable across elevations. We found species-specific variations in specific leaf area, midday leaf water potential, and leaf P concentration across elevations. Decreasing crown width with increasing elevation was associated with decreasing leaf δ18O and ΨL-0700, suggesting that higher stomatal conductance may moderate the loss of carbon assimilation. We elucidated the adaptive strategies of plants in response to environmental change, and showed that physiological traits varied in coordination with structural traits. Future studies incorporating multi-dimensional trait analyses can improve our understanding of the responses of forest ecosystems to climate change and global warming.
Impacts of hydrological conditions on the activities of soil enzymes in temperate floodplain forest sites
Authors: Frymark-Szymkowiak Anna , Karliński Leszek
Published: February 2022

Context The development and survival of floodplain forests are dependent on the occurrence of seasonal flooding that provides soil moisture and nutrient availability suitable for the development of soil microorganisms, which are the main sources of soil enzymes involved in the decomposition and mineralisation of soil organic matter. Aims We compared the soil enzyme activities of a floodplain forest in the Lower Vistula Valley, Poland, cut off for 80 years from the river by artificial embankment, and of two other floodplain forests located in close vicinity and subjected to seasonal flooding. We hypothesised that inhibiting the inflow of the river water to the floodplain forest will alter the soil water and mineral conditions, decreasing the activity of extracellular soil enzymes. Methods Enzyme activity, soil moisture content, and pH were monitored for 3 years in the upper soil level (0–30 cm). The activities of soil β-glucosidase, acid phosphatase, alkaline phosphatase, and nonspecific dehydrogenase were determined by spectrophotometry. Key results Inhibition of floods decreased soil moisture, the concentrations of carbon, nitrogen, and phosphorus, as well as the activity of soil enzymes. Conclusions Forest site and soil depth, but not season, had significant effects on soil chemical and biological features. Soil enzyme activities were significantly positively correlated with soil moisture and the levels of total and organic carbon, total nitrogen, and available phosphorus, as well as the carbon/nitrogen ratio. Implications This information is essential for the protection and restoration of riverine habitats destroyed by human activity.
Annual NO and N
Authors: Lin Feng , Zhang Yaojun , McDaniel Marshall D. , Liu Shuwei , Zou Jianwen
Published: February 2022

Context Overuse of N fertiliser in vegetable cropping systems is known to release of nitric and nitrous oxide to the atmosphere in China. Optimisation of N fertilisation regimes has the potential to mitigate NO and N2O emissions from these N-rich systems. Aims We investigated the effects of different N fertilisation regimes on NO and N2O emissions, and vegetable yields, with particular efforts to estimate annual direct emission factors of NO and N2O under different N fertilisation regimes in greenhouse vegetable fields. Methods Annual NO and N2O fluxes were taken simultaneously using the static chamber-based method from a greenhouse vegetable system in south-east China with four N fertiliser treatments: (1) no N fertiliser (control); (2) chemical N fertiliser application (CF); (3) organic N fertiliser application (OF); and (4) organic-chemical mixed N fertiliser application (MF). Key results N fertilisers significantly increased NO and N2O emissions. Direct emission factors of N fertiliser for NO and N2O were the largest for MF, with an average of 0.99% and 0.67%, respectively. Vegetable yields were only significantly enhanced under OF treatment. Conclusions Relative to the use of chemical N fertiliser, the application of organic-chemical mixed N fertiliser showed not to be effective for mitigating NO and N2O emissions. Instead, sole application of organic N fertiliser was a viable option to enhance vegetable yields but without increasing NO and N2O emissions in greenhouse vegetable systems. Implications Substituting the use of chemical N fertiliser with organic N fertiliser input could benefitvegetable production but without stimulating NO and N2O emissions from vegetable cropping systems in sub-tropical China.
Butterfly eyespots evolved via cooption of an ancestral gene-regulatory network that also patterns antennae, legs, and wings
Authors: Murugesan Suriya Narayanan , Connahs Heidi , Matsuoka Yuji , Das Gupta Mainak , Tiong Galen J. L. , Huq Manizah , Gowri V. , Monroe Sarah , Deem Kevin D. , Werner Thomas , Tomoyasu Yoshinori , Monteiro Antónia
Published: February 2022

Significance

Where do butterfly eyespots come from? One of the long-standing questions in the field of evolution concerns addressing where novel complex traits come from. Here we show that butterfly eyespots, a novel complex trait, likely originated from the redeployment of a preexisting gene-regulatory network regulating antennae, legs, and wings, to novel locations on the wing.
Modeling the instantaneous normal mode spectra of liquids as that of unstable elastic media
Authors: Schirmacher Walter , Bryk Taras , Ruocco Giancarlo
Published: February 2022

Significance

We present a theory, based on an unstable elasticity model with thermally fluctuating elastic constants, which explains the salient features of the instantaneous normal mode (INM) spectrum of a numerically simulated liquid over a large range of temperatures. The INM spectrum of a liquid is obtained in a molecular dynamics (MD) simulation by considering the harmonic eigenvalue spectrum of the potential energy, taken at a given instant (snapshot). Because the INM spectrum records the curvatures of the fluctuating potential landscape of the liquid, an understanding of this spectrum may pave the way toward understanding the liquid to glass transformation process.
Epistatic genetic interactions govern morphogenesis during sexual reproduction and infection in a global human fungal pathogen
Authors: Sun Sheng , Roth Cullen , Floyd Averette Anna , Magwene Paul M. , Heitman Joseph
Published: February 2022

Significance

Cellular development is regulated by a complex web of signaling pathways that respond to both intracellular and extracellular cues. Morphological transitions in pathogenic fungi, such as those observed during sexual reproduction or in response to the host environment, offer tractable models for understanding the principles that govern eukaryotic cell development and morphogenesis. Using the human fungal pathogen
Cryptococcus deneoformans
as a model and applying quantitative trait locus analysis, we defined genes and gene–gene interactions involved in the yeast–hyphal transition and titanization, two morphological developments that are important for adaptation, pathogenesis, and evolution of this fungal pathogen. Our study highlights the conservation and complexity of key signaling pathways in regulating cell development in fungi, as well as other eukaryotes.
Intense Turkish-Dutch bilingualism leads to intense Turkish-Dutch mixing
Authors: Backus Ad , Demirçay Derya
Published: February 2022

Codeswitching in the Turkish migration settings in Western Europe has been studied almost since the beginning of
the labor migration that formed these communities. The patterns of codeswitching have gradually become more complex, which is
demonstrated with reference to data from the Netherlands. Initially it was limited to the insertion of Dutch words into Turkish
utterances, largely needed to fill lexical gaps. Gradually, as a new generation grew up with Dutch education, living most of their
lives in a Dutch social environment, codeswitching patterns grew in complexity, with an increase in alternation between Dutch and
Turkish utterances. Often, these and other patterns are attested in the speech of the same people at the same time, within a
single conversation: they represent a bilingual speech style.

The most recent investigations into Turkish-Dutch codeswitching show how this increasing intensity of bilingualism
in the community has led to increasing integration of the languages in everyday in-group bilingual speech. Of all switches, a
relatively small percentage is taken up by the insertion of content words into either language; yet, codeswitching is not always
straightforward alternation between Turkish and Dutch utterances. Instead, utterances often contain chunks from both languages.
This phenomenon will be illustrated in this article and explained through a usage-based perspective that privileges a
processing-based over a structuralist account, but crucially ties this account to an understanding of the social motivations that
make this kind of bilingual speech possible, or even desired.
Gender in Dutch/Portuguesecodeswitching
Authors: Greidanus Romaneli Miriam , Boers Ivo H. G. , Parafita Couto M. Carmen
Published: February 2022

This study focuses on unveiling the strategies involved in gender assignment in codeswitching between two
gendered languages: Dutch (common/neuter gender) and Portuguese (masculine/feminine gender). We draw on naturalistic speech
(n = 32 speakers), elicited production (n = 35) as well as intuitional data
(n = 57) from Dutch/Portuguese bilinguals stemming from three communities in Paraná, Southern Brazil, aiming
to disentangle the relative roles of linguistic and extralinguistic factors on gender assignment. In unilingual Dutch, we find
that Dutch/Portuguese bilinguals overgeneralize common determiners and adjectives to neuter nouns, similarly to other Dutch
bilinguals outside the Netherlands (Clyne 1977; Clyne and Pauwels 2013; Folmer 1991; Giesbers 1997). In codeswitched
constructions, however, speakers assign common and masculine gender as defaults, in line with the prediction that speakers of
language pairs with no gender values in common prefer gender defaulting in mixed constructions (Klassen 2016). While extralinguistic factors such as age and relative use of the languages shaped
unilingual Dutch production, the patterns during codeswitching were conventionalized across the speaker sample.
Infinite bound states and hydrogen atom-like energy spectrum induced by a flat band
Authors: Zhang Yi-Cai , Zhu Guo-Bao
Published: February 2022

In this work, we investigate the bound-state problem in a one-dimensional spin-1 Dirac Hamiltonian with a flat band. It is found that the flat band has significant effects on the bound states. For example, for Dirac delta potential gδ(x), there exists one bound state for both the positive and negative potential strength g. Furthermore, when the potential is weak, the bound-state energy is proportional to the potential strength g. For square well potential, the flat band results in the existence of infinite bound states for arbitrarily weak potential. In addition, when the bound-state energy is very near the flat band, the energy displays a hydrogen atom-like spectrum, i.e. the bound-state energies are inversely proportional to the square of the natural number n (e.g., E

n
∝ 1/n
2, n = 1, 2, 3, …). Most of the above nontrivial behaviors can be attributed to the infinitely large density of states of the flat band and its ensuing 1/z singularity of the Green function. The combination of a short-ranged potential and flat band provides a new possibility to get an infinite number of bound states and a hydrogen atom-like energy spectrum. In addition, our findings provide some useful insights and further our understanding of the many-body physics of the flat band.
Penetration of plasma jet into porous dielectric layer: confirmed by surface charge dissipation of silicone rubber
Authors: Li Shuang , Fu Yongqiang , Guo Xinzheng , Li Jianjun , Zhang Ruobing
Published: February 2022

The penetration of plasma in the porous structure is important for its application in plasma catalysis, plasma medicine, etc. In this paper, the penetration of plasma species in the porous kaolin layer was investigated. The silicone rubber was chosen as a probe and the inorganic porous dielectric layer was constructed with granular kaolin coated on the surface of silicone rubber. AC and pulsed plasma jets were applied to the silicone rubber, and the surface charge dissipation of bulk silicone rubber was measured to characterize the changes of surface property caused by the plasma penetration. The results showed that plasma could penetrate the porous dielectric layer on the silicone rubber and interact with the surface of silicone rubber, thus accelerating the surface charge dissipation of the bulk silicone rubber. The increase of shallow traps and surface conductivity after plasma treatment was the main reason for the acceleration of surface charge dissipation. The surface charge dissipation is enhanced with the increase of treatment time and the generating voltage of plasma. The surface charge dissipation declined for silicone rubber with a thicker kaolin layer due to the blocking of the kaolin layer on the interaction of plasma and the silicone rubber. For the same kind of plasma, the charge dissipation rate was linearly related to plasma dose which was represented by the energy density of plasma applied on the coated silicone rubber. At the same energy density, the surface charge dissipation of silicone rubber after pulsed plasma treatment was faster than that of AC plasma.
Assessing the relaxation mechanisms contributions on magnetoimpedance effect in YIG/W bilayers
Authors: Santos J G S , Silva E F , Gamino M , Ferreira A , Vaz F , Bohn F , Correa M A
Published: February 2022

Damping parameter plays a key role in the magnetization dynamics of ferri/ferromagnetic materials with potential technological applications. Experimentally the damping parameter can be estimated from the linewidth of the ferromagnetic resonance experiment, which is altered by distinct mechanisms associated with extrinsic contributions, such as spin pumping and two-magnon scattering mechanisms. Here we perform a systematic investigation of the magnetization dynamics through magnetoimpedance effect in Y5Fe3O12(t

Y
I
G

)/W(100 nm) bilayers having t

YIG
between 25 and 125 nm. By modifying the YIG thickness, we explore the contributions of such extrinsic mechanisms to α

eff
. From the structural features, quasi-static magnetic properties, and ferromagnetic resonance results, we interpret our findings for the magnetization dynamics. Our results disclose that the bilayer structure allows us to explore the magnetoimpedance effect in a wide range of frequency and magnetic fields, providing insights on the effective damping parameter.
Thermodefect voltage in graphene nanoribbon junctions
Authors: Aydin Alhun , Sisman Altug , Fransson Jonas , Black-Schaffer Annica M , Dutta Paramita
Published: February 2022

Thermoelectric junctions are often made of components of different materials characterized by distinct transport properties. Single material junctions, with the same type of charge carriers, have also been considered to investigate various classical and quantum effects on the thermoelectric properties of nanostructured materials. We here introduce the concept of defect-induced thermoelectric voltage, namely, thermodefect voltage, in graphene nanoribbon (GNR) junctions under a temperature gradient. Our thermodefect junction is formed by two GNRs with identical properties except the existence of defects in one of the nanoribbons. At room temperature the thermodefect voltage is highly sensitive to the types of defects, their locations, as well as the width and edge configurations of the GNRs. We computationally demonstrate that the thermodefect voltage can be as high as 1.7 mV K−1 for 555–777 defects in semiconducting armchair GNRs. We further investigate the Seebeck coefficient, electrical conductance, and electronic thermal conductance, and also the power factor of the individual junction components to explain the thermodefect effect. Taken together, our study presents a new pathway to enhance the thermoelectric properties of nanomaterials.
Barium titanate-enhanced hexagonal boron nitride inks for printable high-performance dielectrics
Authors: Kim Hyunho , Arbab Adrees , Fenech-Salerno Benji , Yao Chengning , Macpherson Ryan , Kim Jong Min , Torrisi Felice
Published: February 2022

Printed electronics have been attracting significant interest for their potential to enable flexible and wearable electronic applications. Together with printable semiconductors, solution-processed dielectric inks are key in enabling low-power and high-performance printed electronics. In the quest for suitable dielectrics inks, two-dimensional materials such as hexagonal boron nitride (h-BN) have emerged in the form of printable dielectrics. In this work, we report barium titanate (BaTiO3) nanoparticles as an effective additive for inkjet-printable h-BN inks. The resulting inkjet printed BaTiO3/h-BN thin films reach a dielectric constant (ε
r) of ∼16 by adding 10% of BaTiO3 nanoparticles (in their volume fraction to the exfoliated h-BN flakes) in water-based inks. This result enabled all-inkjet printed flexible capacitors with C ∼ 10.39 nF cm−2, paving the way to future low power, printed and flexible electronics.
Highly stable Pt–Co bimetallic catalysts prepared by atomic layer deposition for selective hydrogenation of cinnamaldehyde
Authors: Wang Kaiying , He Xiaoqing , Wang Jee-Ching , Liang Xinhua
Published: February 2022

Pt–Co bimetallic catalysts were deposited on γ-Al2O3 nanoparticles by atomic layer deposition (ALD) and were used for selective hydrogenation of cinnamaldehyde (CAL) to cinnamyl alcohol (COL). High resolution transmission electron microscopy, hydrogen temperature‐programmed reduction, x-ray diffraction, and x-ray photoelectron spectroscopy were used to identify the strong interaction between Pt and Co. The obtained catalysts with an optimal Pt/Co ratio achieved a COL selectivity of 81.2% with a CAL conversion of 95.2% under mild conditions (i.e., 10 bar H2 and 80 °C). During the CAL hydrogenation, the addition of Co on Pt significantly improved the activity and selectivity due to the synergetic effects of Pt–Co bimetallic catalysts, resulted from the transfer of electrons from Co to Pt, which can stabilize the carbonyl groups. The obtained Pt–Co bimetallic catalysts also showed excellent stability due to the strong interaction between the metal nanoparticles and the alumina support. Negligible losses in the activity and selectivity were observed during the recycling experiments, showing the potential for practical applications.
Simple self-organization-based synthesis of gold nanoparticle-implanted ZnO aerogels with good sensing performance to gaseous ethanol
Authors: Xu Kang , Wang Qingqing
Published: February 2022

Simple fabrication of metal-modified oxide aerogels is expected but remains challenging. This work presents a sample one-pot synthesis method for gold nanoparticle (NP) implanted ZnO (Au–ZnO) aerogels just by sequentially adding (CH3COO)2Zn and NaBH4 solutions into a pre-prepared Au colloidal solution. The typically fabricated Au–ZnO aerogels are constituted by ZnO networks implanted with uniform Au NPs. The Au NPs had a size of about 100 nm, and the ZnO nanochains in the networks were about 10 nm in thickness. Further, the proportion of the Au NPs in the final aerogels could be tuned by using different amounts of the Zn precursors. Furthermore, a mechanism based on metal oxidation and oriented connection growth (a self-organization process) has been presented for describing the formation of such Au–ZnO aerogels. In the typical formation, the Zn2+ ions first convert into ZnO beads, and then are self-organized to form networks wrapping the colloidal Au NPs under the effect of linker molecules, and this matches well with the observed experimental results. Most importantly, these Au–ZnO aerogels show great structurally enhanced gas sensing properties to gaseous ethanol compared with a pure ZnO film. They have a fast response (about 30 s), a high selectivity, and quantitative sensing to the target gas. This work has provided a simple preparation method for Au–ZnO aerogels, and also shows their great potential in gas sensing applications.
In situ plasma cleaning of large-aperture optical components in ICF
Authors: Li Yuhai , Bai Qingshun , Guan Yuheng , Zhang Peng , Shen Rongqi , Lu Lihua , Liu Hao , Yuan Xiaodong , Miao Xinxiang , Han Wei , Yao Caizhen
Published: February 2022

The organic contamination damage of large-aperture optical components limits laser energy improvement of inertial confinement fusion (ICF). In situ cleaning of large-aperture optical components via low-pressure plasma is expected to remove organic contaminants from the optical surface. Herein, low-pressure air plasma equipment was proposed and used on surfaces of SiO2 sol–gel antireflection (AR) films in situ by conducting experiments. Its electrical discharge parameters were investigated and optimized during plasma cleaning. Plasma diffusion characteristics and homogeneity in large-aperture windows were analyzed by optical emission spectroscopy. Dramatic degradation in the optical properties of components was observed after organic contamination for 5 h. Transmittance, laser-induced damage threshold and surface morphology observation results demonstrated that low-pressure air plasma removed the organic contaminants from the surface of sol–gel AR films without causing damage and metal contamination. After plasma cleaning, the hydrophilicity of the films increased significantly due to the increase in the polar components of surface free energy. The mechanism of plasma cleaning organic contaminants was confirmed by x-ray photoelectron spectroscopy measurements. These salient results provide a new alternative method for removing organic contaminants in situ from large-aperture optical components and a foundation for improving the energy output of the ICF system.
The Inverse Eigenvalue Problem for a Class of Sub-periodic Generalized Jacobi Matrices
Authors: Wang Qingqing , Jiao Lixin
Published: February 2022

The inverse eigenvalue problem of matrix has practical significance in engineering and scientific calculation. In this paper, the inverse eigenvalue problem of sub-periodic generalized Jacobi matrices is studied. Two eigenvalues and corresponding eigenvectors are used to construct generalized Jacobi matrices. The existence and uniqueness conditions of the solution are discussed, the solution algorithm for the inverse problem is given, and the effectiveness of the algorithm is verified by a numerical example.
Research on decoupling technology of fast mirror platform based on state space feedback
Authors: Yu Yang , Zhang Honggang , Gao Junke , Zuo Shouyin , Shi Pengjie
Published: February 2022

Aiming at the influence of the nonlinearity of the motor of the fast mirror platform mechanism and the complex coupling between the platform azimuth and pitch frames on the fast mirror mechanism, a decoupling control technology based on state space feedback is proposed in this paper. Firstly, according to the dynamic model of the azimuth and pitch frame of the fast mirror platform, the state space equation is established, and the state space variables of the system are obtained. The constructed feedback system is connected in series with the original system to obtain a pseudo linear system, so that the original coupled nonlinear multi output system is transformed into two linear decoupled single input single output subsystems, In order to eliminate the complex coupling of the azimuth and pitch frame of the fast mirror platform mechanism. Finally, the system simulation platform is established in Matlab/Simulink. The results show that the decoupling technology of fast mirror platform based on state space feedback designed in this paper can effectively reduce the coupling between platform azimuth and pitch frames and improve the stability accuracy of the platform.
Detection Method of Distribution Transformer Based on Intelligent Switching Line Switch
Authors: Fang Jian , Zhang Min , Mo Wenxiong , Huang Bai , He Jiaxing , Lin Xiang
Published: February 2022

Automatic and intelligent detection of distribution transformer is an important condition to ensure distribution network zero defect operation. The traditional distribution transformer quality detection system has low integration and automation, and a single function mode, which cannot meet the intelligent detection under different test scenarios. This paper introduces the basic principle of intelligent switching line, and develop a special automatic switching device according to the actual detection process. On this basis, an intelligent switching line switching device is designed according to the test requirements of distribution transformer. Finally, the actual test results show that the proposed distribution transformer detection method based on intelligent switching line switch can significantly reduce the detection time and improve the detection efficiency of distribution transformer.