bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatially targeting and regulating tumor-associated macrophages using a raspberry-like micellar system sensitizes pancreatic cancer chemoimmunotherapy
Authors: Li Ting , Chen Dong , Liu Houqin , Tao Yuan , He Xuan , Zang Shuya , Li Jiaxin , Zhang Ling , Li Man , Liu Ji , He Qin
Published: July 2022

GD@PP/Wtmn mediates polarization of TAMs and tumor cell killing, activating antitumor immunity for enhancing antitumor effects.
Diastereomerically pure rarely functionalized alkenoyl dihydropyrans, 1,6-diketones, and cyclopentanes from acetylene gas and ketones
Authors: Tatarinova Inna V. , Lobanova Natal'ya A. , Ushakov Igor’ A. , Schmidt Elena Yu. , Trofimov Boris A.
Published: July 2022

Alkenoyl dihydropyrans stereoselectively assembled from acetylene gas, ketones and aldehydes in two steps are diastereoselectively transformed into difficult-to-access, rarely functionalized 1,6-diketones and cyclopentanes.
Structural design and control of photocatalytic nitrogen-fixing catalysts
Authors: Xia Yujiao , Xu Yunyun , Yu Xingyu , Chang Kun , Gong Hao , Fan Xiaoli , Meng Xianguang , Huang Xianli , Wang Tao , He Jianping
Published: July 2022

In this paper, we mainly discuss the structure and design of photocatalytic nitrogen-fixing materials, such as introducing various vacancies on the catalyst surface, conducting element doping and constructing heterojunctions.
A starch-regulated adhesive hydrogel dressing with controllable separation properties for painless dressing change
Authors: Yang Minwei , Fei Xu , Tian Jing , Xu Longquan , Wang Yi , Li Yao
Published: July 2022

Herein, we report a starch-regulated adhesive hydrogel dressing. It can achieve rapid separation through the dissociation competition mechanism of polar small molecules, which greatly facilitate dressing replacement.
Mechanically active small intestinal submucosa hydrogel for accelerating chronic wound healing
Authors: Chen Xiao-Ya , Wang Yi , Ma Shi-Qing , Huang Yi-Qian , Jing Wei , Wei Peng-Fei , Yu Xue-Qiao , Zhao Bo
Published: July 2022

The treatment of chronic wounds is still a challenge worldwide.
Temperature dependent scintillation properties and mechanisms of (PEA)2PbBr4 single crystals
Authors: van Blaaderen Jacob Jasper , Maddalena Francesco , Dang Cuong , Birowosuto Muhammad Danang , Dorenbos Pieter
Published: July 2022

Low temperature optical and scintillation characterisation of PEA2PbBr4 single crystals, based on which two potential scintillation mechanisms are proposed.
Fixing the powerhouse: genetic engineering of mitochondrial DNA
Authors: Mutti Christian , Silva-Pinheiro Pedro , Minczuk Michal
Published: July 2022

Mitochondria are complex factories that provide our cells with most of the energy we need to survive and perform daily tasks. They comprise their own small genome, mitochondrial DNA (mtDNA), which contains genes for parts of the energy-producing machinery. Mutations in mtDNA can lead to mitochondrial diseases, which are a devastating group of heterogenous inheritable diseases that can develop at any stage of life. Despite rapid developments in genome engineering for nuclear DNA, the incompatibility of certain techniques in mitochondria has meant that the field of mitochondrial genome modification has been impeded for many years. However, recent advances in mtDNA engineering techniques, such as programmable nucleases and base editors, will allow for a deeper understanding of the processes taking place in mitochondria and improve the prospects of developing treatments for mitochondrial diseases.
Testing the homogeneity of type Ia Supernovae in near-infrared for accurate distance estimations
Authors: Müller-Bravo T. E. , Galbany L. , Karamehmetoglu E. , Stritzinger M. , Burns C. , Phan K. , Iáñez Ferres A. , Anderson J. P. , Ashall C. , Baron E. , Hoeflich P. , Hsiao E. Y. , de Jaeger T. , Kumar S. , Lu J. , Phillips M. M. , Shahbandeh M. , Suntzeff N. , Uddin S. A.
Published: July 2022

Since the discovery of the accelerating expansion of the Universe more than two decades ago, Type Ia Supernovae (SNe Ia) have been extensively used as standardisable candles in the optical. However, SNe Ia have shown to be more homogeneous in the near-infrared (NIR), where the effect of dust extinction is also attenuated. In this work, we explore the possibility of using a low number of NIR observations for accurate distance estimations, given the homogeneity at these wavelengths. We found that one epoch in J and/or H band, plus good gr-band coverage, gives an accurate estimation of peak magnitudes in the J (Jmax) and H (Hmax) bands. The use of a single NIR epoch only introduces an additional scatter of ∼0.05 mag for epochs around the time of B-band peak magnitude (Tmax). We also tested the effect of optical cadence and signal-to-noise ratio (S/N) in the estimation of Tmax and its uncertainty propagation to the NIR peak magnitudes. Both cadence and S/N have a similar contribution, where we constrained the introduced scatter of each to < 0.02 mag in Jmax and < 0.01 in Hmax. However, these effects are expected to be negligible, provided the data quality is comparable to that obtained for observations of nearby SNe (z ≲ 0.1). The effect of S/N in the NIR was tested as well. For SNe Ia at 0.08 < z ≲ 0.1, NIR observations with better S/N than that found in the CSP sample is necessary to constrain the introduced scatter to a minimum (≲0.05 mag). These results provide confidence for our FLOWS project that is aimed at using SNe Ia with public ZTF optical light curves and few NIR epochs to map out the peculiar velocity field of the local Universe. This will allow us to determine the distribution of dark matter in our own supercluster, Laniakea, and to test the standard cosmological model by measuring the growth rate of structures, parameterised by fD, and the Hubble-Lemaître constant, H0.
Fast algorithm for simulating light curves of stars at extreme magnification affected by microlensing
Authors: Diego J. M.
Published: July 2022

We present a fast algorithm aimed at reproducing the light curves of distant stars undergoing microlensing near critical curves. The need for these type of algorithms has been motivated by recent observations of microlensing events of distant stars at high redshift and involving extreme magnification factors. The algorithm relies on a low-resolution computation of the deflection field due to an ensemble of microlenses near critical curves and takes advantage of the gradually varying nature of the deflection field to infer the magnification of the unresolved images. The algorithm is capable of resolving microlenses at cosmological distances with planet-sized masses, as well as typical background luminous stars of a few solar radii. Using this algorithm, light curves covering decades of relative motion between the source and the web of microcaustics, at nanoarcsec resolution, can be reproduced within a matter of minutes on a basic laptop. Classic inverse ray tracing simulations at the same resolution would take days or weeks to produce, consuming massive computational resources.
An analytical approach to evaluating magnetic-field closure and topological changes in FRC devices
Authors: Ahsan T. , Cohen S. A.
Published: July 2022

We describe mathematical methods based on optimizing a modified non-linear flux function (MFF) to evaluate whether odd-parity perturbations affect the local closure of magnetic field lines in field-reversed configurations. Using the MFF methodology, quantitative formulas are derived that provide the shift of the field minimum and the threshold for field-line opening, a discontinuous change in field topology.
Ferroelectric diode characteristic and tri-state memory in self-assembled BiFeO3 nanoislands with cross-shaped domain structure
Authors: Zhou Xiang , Sun Haoyang , Luo Zhen , Zhao Haoyu , Liang Deshan , Jafri Hasnain Mehdi , Huang Houbing , Yin Yuewei , Li Xiaoguang
Published: July 2022

Exotic polarization domain configurations in BiFeO3 nanoislands have recently been achieved, promising for exploring next-generation nanoelectronics. Here, different from the earlier reported BiFeO3 nanoislands with a very thin cross-shaped domain wall on LaAlO3 substrates, we observed the cross-shaped domains with a downward polarization separating quad-domains with an upward polarization, which is confirmed by spherical aberration corrected scanning transmission electron microscopy and piezoresponse force microscopy. Interestingly, the cross- and quad-domains show diode-like transport behaviors but with different rectification directions owing to their different polarization orientations. Specifically, an intriguing two-step ferroelectric polarization switching can be realized, which locally results in a tri-state nonvolatile memory. These results broaden the understanding of the interesting polarization configurations in BiFeO3 nanoislands and highlight their potential as high-density information storage.
Investigation of flame structure and precessing vortex core instability of a gas turbine model combustor with different swirler configurations
Authors: Mardani Amir , Asadi Benyamin , Beige Amir A.
Published: July 2022

Numerical simulation of a dual-swirl gas turbine model combustor is performed under cold and reacting flow conditions using a three-dimensional unsteady Reynolds-averaged Navier–Stokes approach. A multi-species chemical mechanism is used in this study for the analysis of the numerous radicals participating in the ignition process and the flame structure. The other objective of this study is to investigate the flow field under different injector configurations, including both co-rotating and counter-rotating swirler arrangements, different swirl intensities, and vane areas. A comparison of the results with experimental data shows that the predicted velocity and temperature profiles follow the experimental data reasonably. In these studies, a precessing vortex core is found in the shear layer of the inner recirculation zone for all injector arrangements considered, and a co-rotating vortex exists in the outer shear layer for some of these arrangements. OH mass fraction field shows that the reactions take place mostly near the vortex core. Furthermore, it is shown that the build-up process of H2O2 and CH2O inside the cold jet has an important effect on combustion initiation. In addition, the formation and consumption of the H atoms in the recirculation zones and the balance between OH and H2O2 are shown to have important roles in the flame formation process. Finally, the precession frequency of the PVC is found to scale almost linearly with the spatial gradient of swirl velocity in the inner swirler and almost independent from the inclusion of the combustion reactions.
War and peace between electrostatic and van der Waals forces regulate translational and rotational diffusion
Authors: Matyushov Dmitry V.
Published: July 2022

In the Stokes–Einstein picture, diffusion of a Brownian particle or a molecule in a liquid solvent is caused by unbalanced fluctuations of osmotic forces on different sides of the particle. When the particle carries a charge or a higher multipolar moment, this picture is amended by fluctuations of electrostatic forces producing dielectric friction. Dielectric friction slows down both the translational and rotational diffusion. While this picture is well established and is physically sound, standard theories grossly overestimate the magnitude of dielectric friction for small dipolar solutes and larger colloidal particles, such as proteins. Motivated by recent simulation studies, this Perspective discusses the interplay between osmotic (van der Waals) and electrostatic forces in promoting molecular and colloidal diffusion. Much can be learned about microscopic friction mechanisms from statistical and dynamical correlations between osmotic and electrostatic forces.
Probing the charge and heat transfer channels in optically excited graphene — transition metal dichalcogenide hybrids using Johnson noise thermometry
Authors: Majumdar Aniket , Kakkar Saloni , Anil Nivedith Kuttikunnummal , Paul Tathagata , Phanindra Sai T. , Watanabe Kenji , Taniguchi Takashi , Ghosh Arindam
Published: July 2022

Graphene (Gr)–transition metal dichalcogenide (TMDC) hybrids are promising platforms for achieving sensitive and ultra-fast photodetection. The process of photo-detection in such van der Waals hybrids is usually dictated by the formation of excitons followed by the transfer of charge and energy from the TMDC layer to graphene, but they have not been explored simultaneously in the same device before. In this work, we have investigated optically excited Gr–WS2 (tungsten disulfide) heterostructures using both standard electrical transport and Johnson noise thermometry. At large negative gate voltages, the experimentally observed photoresponse cannot be explained from conventional photogating but was found to host an increase in electron temperature as large as ∼4 K. Time dependence of the transport and the noise reveals that the change in temperature and photoresistance can originate from distinct microscopic processes. The findings can be exploited for the development of Gr–TMDC based ultra-fast bolometers.
Non-monotonic changes in conductance of Bi(111) films induced by Cs adsorption
Authors: Denisov N. V. , Matetskiy A. V. , Zotov A. V. , Saranin A. A.
Published: July 2022

Effects of Cs adsorption on the conductance of Bi(111) films were studied using scanning tunneling microscopy (spectroscopy) observations and in situ transport measurements at low temperatures. Based on the obtained results and the known data on the Bi(111) electronic band structure, Cs-induced modifications of the band structure were shown to control the changes in the Bi(111) film conductance. Adsorbed Cs atoms donate electrons to Bi(111), causing the shifting of the system Fermi level upward along the energy scale. Due to the peculiarities of the Bi(111) band structure, the density of states at the Fermi level, which is directly related to the carrier density, varies non-monotonically with shifting of the Fermi level. Conductance changes in the same way with Cs coverage, namely, decreases almost twice at 0.011 ML of Cs, restores to the initial value at 0.025 ML of Cs, and grows gradually up to 0.167 ML; the maximal coverage when adsorbed Cs remains an assembly of the individual adatoms. Thus, Cs adsorption shows up as an effective tool to tune the electronic and transport properties of the Bi(111) films. The results also prove an effective surface characteristic of the electron transport in the Bi films.
Information theory: A foundation for complexity science
Authors: Golan Amos , Harte John
Published: July 2022

Modeling and inference are central to most areas of science and especially to evolving and complex systems. Critically, the information we have is often uncertain and insufficient, resulting in an underdetermined inference problem; multiple inferences, models, and theories are consistent with available information. Information theory (in particular, the maximum information entropy formalism) provides a way to deal with such complexity. It has been applied to numerous problems, within and across many disciplines, over the last few decades. In this perspective, we review the historical development of this procedure, provide an overview of the many applications of maximum entropy and its extensions to complex systems, and discuss in more detail some recent advances in constructing comprehensive theory based on this inference procedure. We also discuss efforts at the frontier of information-theoretic inference: application to complex dynamic systems with time-varying constraints, such as highly disturbed ecosystems or rapidly changing economies.
Genetic architecture of dispersal and local adaptation drives accelerating range expansions
Authors: Deshpande Jhelam N. , Fronhofer Emanuel A.
Published: July 2022

Contemporary evolution has the potential to significantly alter biotic responses to global change, including range expansion dynamics and biological invasions. Models predicting range dynamics often make highly simplifying assumptions about the genetic architecture underlying relevant traits. However, genetic architecture defines evolvability and higher-order evolutionary processes, which determine whether evolution will be able to keep up with environmental change or not. Therefore, we here study the impact of the genetic architecture of dispersal and local adaptation, two central traits of high relevance for range expansions, on the dynamics and predictability of invasion into an environmental gradient, such as temperature. In our theoretical model we assume that dispersal and local adaptation traits result from the products of two noninteracting gene-regulatory networks (GRNs). We compare our model to simpler quantitative genetics models and show that in the GRN model, range expansions are accelerating and less predictable. We further find that accelerating dynamics in the GRN model are primarily driven by an increase in the rate of local adaptation to novel habitats which results from greater sensitivity to mutation (decreased robustness) and increased gene expression. Our results highlight how processes at microscopic scales, here within genomes, can impact the predictions of large-scale, macroscopic phenomena, such as range expansions, by modulating the rate of evolution.
A highly efficacious live attenuated mumps virus–based SARS-CoV-2 vaccine candidate expressing a six-proline stabilized prefusion spike
Authors: Zhang Yuexiu , Lu Mijia , Mahesh K C , Kim Eunsoo , Shamseldin Mohamed M. , Ye Chengjin , Dravid Piyush , Chamblee Michelle , Park Jun-Gyu , Hall Jesse M. , Trivedi Sheetal , Chaiwatpongsakorn Supranee , Kenny Adam D. , Murthy Satyapramod Srinivasa , Sharma Himanshu , Liang Xueya , Yount Jacob S. , Kapoor Amit , Martinez-Sobrido Luis , Dubey Purnima , Boyaka Prosper N. , Peeples Mark E. , Li Jianrong
Published: July 2022

With the rapid increase in SARS-CoV-2 cases in children, a safe and effective vaccine for this population is urgently needed. The MMR (measles/mumps/rubella) vaccine has been one of the safest and most effective human vaccines used in infants and children since the 1960s. Here, we developed live attenuated recombinant mumps virus (rMuV)–based SARS-CoV-2 vaccine candidates using the MuV Jeryl Lynn (JL2) vaccine strain backbone. The soluble prefusion SARS-CoV-2 spike protein (preS) gene, stablized by two prolines (preS-2P) or six prolines (preS-6P), was inserted into the MuV genome at the P–M or F–SH gene junctions in the MuV genome. preS-6P was more efficiently expressed than preS-2P, and preS-6P expression from the P–M gene junction was more efficient than from the F–SH gene junction. In mice, the rMuV-preS-6P vaccine was more immunogenic than the rMuV-preS-2P vaccine, eliciting stronger neutralizing antibodies and mucosal immunity. Sera raised in response to the rMuV-preS-6P vaccine neutralized SARS-CoV-2 variants of concern, including the Delta variant equivalently. Intranasal and/or subcutaneous immunization of IFNAR1
−/−
mice and golden Syrian hamsters with the rMuV-preS-6P vaccine induced high levels of neutralizing antibodies, mucosal immunoglobulin A antibody, and T cell immune responses, and were completely protected from challenge by both SARS-CoV-2 USA-WA1/2020 and Delta variants. Therefore, rMuV-preS-6P is a highly promising COVID-19 vaccine candidate, warranting further development as a tetravalent MMR vaccine, which may include protection against SARS-CoV-2.
Identification of a nematic pair density wave state in Bi
2
Sr
2
CaCu
2
O
8+x
Authors: Chen Weijiong , Ren Wangping , Kennedy Niall , Hamidian M. H. , Uchida S. , Eisaki H. , Johnson Peter D. , O’Mahony Shane M. , Davis J. C. Séamus
Published: July 2022

Electron-pair density wave (PDW) states are now an intense focus of research in the field of cuprate correlated superconductivity. PDWs exhibit periodically modulating superconductive electron pairing that can be visualized directly using scanned Josephson tunneling microscopy (SJTM). Although from theory, intertwining the
d
-wave superconducting (DSC) and PDW order parameters allows a plethora of global electron-pair orders to appear, which one actually occurs in the various cuprates is unknown. Here, we use SJTM to visualize the interplay of PDW and DSC states in Bi
2
Sr
2
CaCu
2
O
8+x
at a carrier density where the charge density wave modulations are virtually nonexistent. Simultaneous visualization of their amplitudes reveals that the intertwined PDW and DSC are mutually attractive states. Then, by separately imaging the electron-pair density modulations of the two orthogonal PDWs, we discover a robust nematic PDW state. Its spatial arrangement entails Ising domains of opposite nematicity, each consisting primarily of unidirectional and lattice commensurate electron-pair density modulations. Further, we demonstrate by direct imaging that the scattering resonances identifying Zn impurity atom sites occur predominantly within boundaries between these domains. This implies that the nematic PDW state is pinned by Zn atoms, as was recently proposed [Lozano
et al.
,
Phys. Rev. B
103, L020502 (2021)]. Taken in combination, these data indicate that the PDW in Bi
2
Sr
2
CaCu
2
O
8+x
is a vestigial nematic pair density wave state [Agterberg
et al. Phys. Rev. B
91, 054502 (2015); Wardh and Granath arXiv:2203.08250].
Explaining the difficulty with L2 acquisition of scope
interpretation by speakers of a scope-rigid language
Authors: Kimura Takayuki
Published: July 2022

This study explores the L2 acquisition of quantifier scope
in English, a notably difficult property to acquire by speakers of a
scope-rigid language like Japanese. This study examines the
knowledge of universal quantifiers in English that Japanese Learners
of English (JLEs) have, focusing on the distributivity and
collectivity of the quantifiers. Results of a picture-based
acceptability judgment task showed that JLEs had problems with scope
judgments and interpreted every NP as a
distributive/collective quantifier akin to all
NPPL
in the grammar of English native
speakers. Thus, this study implies that issues with the L2
acquisition of scope ambiguity are rooted in a problem with the
reassembly of quantificational features of universal quantifiers, in
accord with Lardiere
(2008, 2009).
Definiteness and argument position in the interpretation of bare
nouns
Authors: Stern Michael C. , Dayal Veneeta , Martohardjono Gita , Chen Ming , Madsen II Christen N.
Published: July 2022

We investigate the hypothesis that nouns in article-less
languages are unambiguous with respect to definiteness, an
unambiguity that is evident in the interpretation of ungrammatical
“bare” or article-less singular nouns in L2 English. Specifically,
we tested the hypothesis that bare nouns in L2 English are
interpreted as definite, administering an acceptability judgment
task to intermediate L2 learners of English whose native language is
Mandarin. We used sentences containing bare singular nouns in
different syntactic positions and discourse contexts. We found bare
subjects to be most acceptable in contexts that required definites,
while bare objects were acceptable across contexts. Bare nouns in L2
English are argued to be unambiguous, following a systematic pattern
determined by argument position and discourse context.
Transfer of prosodic representation
Authors: Ingham Jacqueline
Published: July 2022

This study examines the spoken suppliance of inflectional
morphology by L1 Bengali speakers of L2 English in the phonological
framework of the Prosodic Transfer Hypothesis (Goad, White, & Steele, 2003; Goad & White, 2004;
Goad & White,
2006, et seq.). Data from a semi-spontaneous elicitation task
suggests that, at lower levels of proficiency, production of
inflection is partially conditioned by the stem vowel in terms of
vowel length and the voicing status of the stem-final consonant.
This finding is proposed to be indicative not only of transfer of L1
prosodic representations, but also transfer of L1 word minimality
requirements and moraic structure below the level of the prosodic
word. Evidence of such transfer is arguably visible when there is a
mismatch between word minimality and the distribution of syllable
weight in the L1 and L2.
Interference-based and capacity-based approaches to working
memory in second language sentence processing
Authors: Cunnings Ian
Published: July 2022

The role that working memory may play in explaining
potential differences between native and non-native sentence
processing has been increasingly debated. In this chapter, I discuss
how the conceptualisation of working memory is crucial to our
understanding of its role in second language processing. In
particular, I compare capacity-based approaches that focus on
working memory resources and interference-based approaches that
focus on memory encoding and retrieval. After reviewing evidence for
both approaches to working memory, I argue that interference-based
accounts provide a promising approach for examining the role of
working memory in second language processing. Although I focus on
non-native sentence processing, I also touch on related issues in
second language acquisition.
Heritage language speakers inform the critical period hypothesis
for first and second language acquisition
Authors: Montrul Silvina
Published: July 2022

This chapter considers how heritage language speakers,
bilinguals exposed to their L1 since birth either exclusively or
simultaneously with the majority language, shed new light on the
role of age in language acquisition. Investigating the ultimate
attainment of bilinguals with early and late exposure to their L1
and L2 helps disentangle how the roles of previous linguistic
knowledge and of quantity and quality of input interact with age of
onset of bilingualism. Comparing the linguistic and processing
abilities of heritage speakers and L2 learners allows us to
understand how the timing of input interacts with situational
factors and elucidates the developmental schedule of different
modules of the grammar. Early exposure is critical for aspects of
phonology, syntax, and morphology.
Evidentiality and the QUD
Authors: Gyuris Beáta
Published: July 2022

The aim of the paper is to sketch a unified account of the denotation of talán ‘perhaps’
in Hungarian, which appears in declaratives and polar interrogatives encoding assertions and questions. It is suggested for
the first time that talán is not only an inferential or conjectural evidential, but also makes reference to
the current question under discussion. The account explains some interpretational effects of talán, including
the absence of the “interrogative flip” or the obligatory rhetorical question readings of polar interrogatives without
constituent focus, which are discussed here for the first time.
Relationship between risk factors of hearing loss and the results of otoacoustic emission in newborns
Authors: Bagheri Fereshteh , Miresmaeili Zeinab , Ahmadpour-kacho Mousa , Ziatabar Ahmadi Zohreh
Published: July 2022

Objective

Congenital hearing loss is a disabling and multi-factorial disease that affects on newborn and children. This study aims to demonstrate the relationship between risk factors for hearing loss and the results of Otoacoustic emission in Iranian newborns.

Methods

We have retrospectively considered 536 newborns admitted to the Audiology Department of a Children’s Hospital in the north of Iran. Transient Evoked Otoacoustic Emissions (TEOAEs) was recorded during the first week of birth, and the risk factors of hearing loss were collected.

Results

We found that parent relatives and family history were significantly correlated with OAEs refer results. Moreover, hyper-bilirubinemia indicated a significant correlation only with first right OAEs. There was a significant correlation between gender and first left and right OAEs. Other risk factors such as seizure, transient tachypnoea of the newborn (TTN) and respiratory distress syndrome (RDS), and lip cleft had a significant correlation with first left and right OAEs results; however, these correlations were not relatively highlighted.

Conclusions

Generally, our data confirm that hearing screening is an absolute necessity in the greater number of newborns. People who got consanguineous marriages should be aware of high incidence of the congenital hearing loss due to parent relatives and family history.
Atmospheric micro-sized cold plasma jet created by a long and ultra-flexible generator with sputtered gold thin film electrode
Authors: Wang Tao , Wang Jiahao , Wang Shengquan , Chen Sile , Wang Xin , Yang Weizhi , Li Meng , Shi Liping
Published: July 2022

Atmospheric cold plasma jets with various configurations have drawn intense interests in diverse applications, such as surface modification and endoscopic applications. In this paper, a long and ultra-flexible micro-sized cold plasma jet generator is presented and its characteristics are analyzed. The generator mainly consists of two concentric silicone tubes with the inner one acting as the gas channel and the outer one acting as insulating layer of heat and high voltage. Gold thin film was sputtered on the circular surface of inner tube to work as the electrode as well as separation layer of ultraviolet radiation. Electrical, optical and thermal characteristics of this generator were investigated. Cold microplasma jet can be generated and ejected to the ambient air with the length varied from 0.1 m to 2.5 m, and it can impact on the finger without electric and heat sensation. Optical emission spectra analysis indicated that reactive species like OH and O atoms were generated in the plasma. This device exhibits ultra-flexible property which can be arbitrarily bent and plugged into complex and deep environment. Localized internal surface modification of polyvinyl chloride tube using this microplasma jet was also demonstrated and the result showed that surface wettability can be greatly improved after plasma treatment. This generator shows great potential for internal surface processing, plasma endoscopic and maskless lithography applications.
A numerical modeling approach to estimate the piezoresistance of diffused resistors with experimental validation
Authors: Meena K V , Mathew Ribu , Ravi Sankar A
Published: July 2022

Silicon piezoresistive sensors have been widely used for many applications in recent decades. Monocrystalline silicon resistors are realized using an ion-implantation or a thermal diffusion process with a Gaussian or complementary error function profile. However, over the years, most researchers have neglected the doping concentration profile of the piezoresistor in the modeling stages resulting in erroneous responses that are far removed from experimental results of fabricated resistive sensors. In the present work, we propose a simulation approach to accurately estimate the piezoresistance of thermally diffused resistors with a non-uniform doping profile. We have modeled the diffused resistor as a parallel combination of several small slices, each having a unique piezoresistive coefficient. Three different slicing strategies were investigated to evaluate the impact of the piezoresistive coefficients, the electrical resistivity of the resistor slices, and the stress profile across the thickness of the resistor embedded in an accelerometer device. The cumulative impact of these parameters on the sensor’s overall sensitivity is evaluated. Further, we have also studied the influence of the accelerometer’s flexure thickness on the sensor’s sensitivity. It is observed from the simulation results that one of the slicing strategies with more slices at the surface of the resistor results in less than 1% error compared to the experimental results of an accelerometer device with a 60 µm flexure thickness.
Microfluidic biochip platform sensitized by AgNPs for SERS based rapid detection of uric acid
Authors: Mishra Shubham , Goel Sanket , Dwivedi Prabhat K
Published: July 2022

Herein, a novel microfluidic-biochip enabled with surface enhanced Raman spectroscopy (SERS) as a readout has been demonstrated for uric acid (UA) detection as point-of care (POC) device. Three different biochip designs (D1, D2 and D3) containing pillars in a microchannel with different bending ratios were conceived and optimized for various mixing parameters using a multiphysics simulation tool. The microchannel, integrated with pillars, provide pressure perturbation, sharp corners, and variation in bending ratio improves phase shift and mixing index. Subsequently the microfluidic-biochips were fabricated by a combination of photo-and soft-lithography, and bonding strength between two Polydimethylsiloxane substrates were found stable up to a flow rate of 1.8 ml min−1. Further to realize SERS activity in the microfluidic-biochip, cubic shape silver nanoparticles (AgNPs), with an average size ∼68 nm, were synthesized using poly-ol method. The SERS activity was optimized by simultaneously flowing AgNPs and crystal violet (CV) dye of 10−6M, with double inlet in the reservoir and highest sensitivity was achieved in the D3 biochip. Further, D3 biochip was employed for detection of extended concentrations of CV and UA. The enhancement factor limit of detection and relative standard deviation was found to be 2 × 107, 8.9 × 10−11 and 2.7% respectively for CV and 3.1 × 103, 3.2 × 10−7 and 2.9% respectively for UA. Interference of UA with lactic acid has been tested and device was able to detect signature peaks of both biomarkers up to 50 × 10−9 M concentration. Thus, the developed microfluidic-biochip device has potential to be used in a POC setting for onsite detection of biomarkers.
Preparation of β-Ga2O3 films on off-angled sapphire substrates and solar-blind ultraviolet photodetectors
Authors: Zhu Yuxia , Li Yuewen , Xiu Xiangqian , Sun Xinyu , Xie Zili , Tao Tao , Chen Peng , Liu Bin , Ye Jiandong , Zhang Rong , Zheng Youdou
Published: July 2022

β-Ga2O3 films have been prepared on (0001) sapphire substrates with different off-axis angles toward

<
11

2
ˉ

0
>

by sol–gel method and the solar-blind ultraviolet photodetectors (PDs) with metal-semiconductor-metal structure have been fabricated on these films. The effects of off-angled sapphire substrates on the surface morphology and crystal quality of β-Ga2O3 films have been systematically investigated. All the results indicate that to some extent the larger off-angled sapphire substrate could lead to the smoother surface morphology and higher crystal quality of β-Ga2O3 films. Reduction in the numbers of in-plane rotational domains for β-Ga2O3 films on off-angled substrates may result in the above-mentioned improvement, which have been confirmed by x-ray diffraction ϕ-scan. β-Ga2O3 film grown on ∼7° off-angled sapphire substrate has (

400

) preferred orientation with the single-domain growth mode. Besides, the performance of β-Ga2O3 PDs fabricated on different off-angled substrates show the same trend with changing the off-axis angles. The β-Ga2O3 PD fabricated on ∼7° off-angled sapphire substrate has excellent optical characteristics with large photocurrent to dark current ratio of 430.53 and high UV–visible rejection ratio of 1.42 × 103. These results would be helpful for improving the crystal-quality of hetero-epitaxy β-Ga2O3 films by using off-angled sapphire substrates and fabricating the cost-effective mass-producible solar-blind ultraviolet PDs by sol–gel method.
Pressure effect on magnetism and valence in ferromagnetic superconductor Eu(Fe0.75Ru0.25)2As2
Authors: Nix Zachary , Zhao Jiyong , Alp Esen E , Xiao Yuming , Zhang Dongzhou , Cao Guang-Han , Vohra Yogesh K , Bi Wenli
Published: July 2022

Eu(Fe0.75Ru0.25)2As2 is an intriguing system with unusual coexistence of superconductivity and ferromagnetism, providing a unique platform to study the nature of such coexistence. To establish a magnetic phase diagram, time-domain synchrotron Mössbauer experiments in 151Eu have been performed on a single crystalline Eu(Fe0.75Ru0.25)2As2 sample under hydrostatic pressures and at low temperatures. Upon compression the magnetic ordering temperature increases sharply from 20 K at ambient pressure, reaching ∼49 K at 10.1 GPa. With further compression, the magnetic order is suppressed and eventually collapses. Isomer shift values from Mössbauer measurements and x-ray absorption spectroscopy data at Eu L
3 edge show that pressure drives Eu ions to a homogeneous intermediate valence state with mean valence of ∼2.4 at 27.4 GPa, possibly responsible for the suppression of magnetism. Synchrotron powder x-ray diffraction experiment reveals a tetragonal to collapsed-tetragonal structural transition around 5 GPa, a lower transition pressure than in the parent compound. These results provide guidance to further work investigating the interplay of superconductivity and magnetism.
Optimized photoelectric characteristics of MAPbCl3 and MAPbBr3 composite perovskite single crystal heterojunction photodetector
Authors: Liu Chao , Chen Hang , Lin Ping , Hu Haihua , Meng Qingyu , Xu Lingbo , Wang Peng , Wu Xiaoping , Cui Can
Published: July 2022

MAPbBr3 single crystal (SC) thin layer was successfully grown on MAPbCl3 SC substrate to form perovskite SC heterojunction. Planar structure electrodes are deposited by thermal evaporation on the surfaces of MAPbCl3, MAPbBr3, and SCs heterojunction, respectively to evaluate their photoelectric performance. The SC heterojunction device exhibits excellent unidirectional conductivity in the voltage-current curves. Meanwhile, the current–time curves prove that SC heterojunction devices can effectively utilize the advantages of MAPbCl3 and MAPbBr3, possessing relatively low dark current (∼300 nA), which is comparable to the dark current of MAPbCl3, but very high photocurrent (∼3500 nA), which is equivalent to the photocurrent of MAPbBr3. Rather than the photocurrent overshot and decay occurring at the exposure of light illumination in the MAPbBr3 device, the photocurrent is extremely stable without overshot and decay in the SC heterojunction device. The light-to-dark ratio of the SC heterojunction device is twice that of MAPbCl3 device and three times that of MAPbBr3 device. Furthermore, the detectivity of the heterojunction device reaches as high as

∼

7

×

1

0

11

 Jones

, an order of magnitude higher than MAPbCl3 and MAPbBr3. The excellent characteristics of SC heterojunction further expand the practical application prospect of perovskite materials.
Simulating the Dicke lattice model and quantum phase transitions using an array of coupled resonators
Authors: Leng Si-Yun , Lü Dong-Yan , Yang Shuang-Liang , Ma Ming , Dong Yan-Zhang , Zhou Bo-Fang , Zhou Yuan
Published: July 2022

A proposal for simulating the Dicke-Lattice model in a mechanics-controlled hybrid quantum system is studied here. An array of coupled mechanical resonators (MRs) can homogeneously interact with a group of trapped Bose–Einstein condensates (BECs) via the gradient magnetic field induced by the oscillating resonators. Assisted by the classical dichromatic radio-wave fields, each subsystem with the BEC-MR interaction can mimic the Dicke type spin-phonon interaction, and the whole system is therefore extended to a lattice of Dicke models with the additional adjacent phonon-phonon hopping couplings. In view of this lattice model with the Z
2 symmetry, its quantum phase transitions behavior can be controlled by this periodic phonon-phonon interactions in the momentum space. This investigation may be considered as a fresh attempt on manipulating the critical behaviors of the collective spins through the external mechanical method.
Patient behavior detection based on time-frequency fusion of FMCW radar
Authors: Xu Zhimeng , Zhang Shanshan , Chen Liangqin , Wu Zhenbin
Published: July 2022

This paper proposes a novel time-frequency feature fusion method to recognise patients’ behaviours based on the Frequency Modulated Continuous Wave (FMCW) radar system, which can locate patients as well as recognise their current actions and thus is expected to solve the shortage of medical staff caused by the novel coronavirus pneumonia (COVID-19). To recognise the patient’s behaviour, the FMCW radar is utilised to acquire point clouds reflected by the human body, and the micro-Doppler spectrogram is generated by human motion. Then features are extracted and fused from the time-domain information of point clouds and the frequency-domain information of the micro-Doppler spectrogram respectively. According to the fused features, the patient’s behaviour is recognised by a Bayesian optimisation random forest algorithm, where the role of Bayesian optimisation is to select the best hyper-parameters for the random forest, i.e. the number of random forest decision trees, the depth of leaves, and the number of features. The experimental results show that an average accuracy of 99.3% can be achieved by using the time-frequency fusion with the Bayesian optimisation random forest model to recognise six actions.
Characterization of absolute cavity radiometers for traceability to SI of solar irradiance
Authors: Balenzategui J L , de Lucas J , Cuenca J , González-Leiton A , Molero M , Fabero F , Silva J P , Mejuto E , Muñoz R , Arce A , Prieto E
Published: July 2022

Solar-type cavity radiometers are instruments of the highest metrological level for measuring solar direct normal irradiance. To ensure their traceability and performance, they are periodically compared to the World Group of Standards, which realizes the World Radiometric Reference (WRR), in the International Pyrheliometer Comparisons (IPCs). Additionally, they can be characterized in an absolute way, with direct traceability to SI units and with their measurement uncertainty calculated. This paper describes the different techniques and procedures applied for the characterization and calibration of solar cavity radiometers, with the main results obtained to date in the case of an Automatic Hickey–Frieden (AHF) radiometer. Voltmeters, resistors, temperature sensors and the area of the precision apertures have been calibrated, while the effective absorptance, temperature coefficients, optical scattering and non-equivalence factor have been evaluated. The temperature dependence of the electrical current in the cavity heater has also been analysed. The resulting corrections obtained for the AHF by characterization are compatible with the WRR factors obtained by this instrument in the past IPCs. An uncertainty of 0.42% (k = 1) has been obtained, and this paper discusses further improvements that may be able to reduce this figure to the desired expanded uncertainty of U = 0.1% (k = 2).
Bayesian approach to pyrometry during intercritical annealing of advanced high strength steel
Authors: Suleiman Fatima K , Lin Kaihsiang , Tsang Roger , Daun Kyle J
Published: July 2022

Precise thermal control during intercritical annealing is essential to the production of advanced high strength steels (AHSS). Measuring the temperature of the steel strip through pyrometry requires detailed knowledge of the spectral emissivity of the steel strip, which is imperfectly known since it varies with wavelength, direction, temperature, surface roughness, and oxidation, the latter depending on alloy composition and processing conditions. This study presents a Bayesian pyrometry methodology in which temperature and spectral emissivity are described as unknown stochastic variables that are inferred simultaneously. Additional information about the spectral emissivity obtained through ex situ characterization are incorporated into the inference through maximum likelihood priors. While standard pyrometry methods provide a point estimate of surface temperature, the Bayesian framework infers the posterior probability density, which will allow galvanizers to better assess the reliability of the pyrometrically-inferred temperature.
Optimal placement of distribution-level synchrophasor sensors for distribution system
Authors: Chen Tengpeng , Liu Fangyan , Chen Xuebing , Sun Lu , Amaratunga Gehan A J
Published: July 2022

This paper proposes a new method for the placement of the important synchrophasor sensors, the distribution-level phasor measurement units (DPMUs). A new objective function is developed to achieve minimization of distribution system state estimation errors where the limited number of DPMUs, the zero injection buses, the limited DPMU channels and the supervisory control and data acquisition measurements are taken into account. The A-optimal experimental design criterion is used to formulate the proposed objective function and constraints. The state estimates are obtained by using the maximum likelihood estimator where both Gaussian and non-Gaussian measurement noise scenarios are studied. The performance of the proposed method is demonstrated by simulations on IEEE 34-bus and 123-bus distribution systems.
Stable and flexible photodetector based on liquid-phase exfoliated titanium disulfide nanosheets
Authors: Liao Yanmo , Huang Zongyu , Qiao Hui , Zhou Yang , Yang Han , Qi Xiang
Published: July 2022

Herein, the TiS2 nanosheets (NSs) are prepared from the TiS2 bulk by the liquid-phase exfoliation to fabricate photoelectrochemical-type (PEC) photodetector. SEM images and Raman spectra show the successful acquisition of the TiS2 NSs. The as-prepared TiS2 photodetector shows self-powered ability with an applicable photoresponsivity that is about 0.37 μA W−1 under zero bias potential and 80 mW cm−2 visible light, and the response time of rise is 0.67 s and the decay time is 2.81 s. In this case, the photodetector is made of ITO-coated polyethylene terephthalate (PET), so it can maintain stable performance under the bending conditions. These results display that the as-prepared photodetector has excellent photoelectric properties, which facilitates the development of TiS2 NSs in optoelectronic devices.
Third quadrant overvoltage ruggedness of p-gate GaN HEMTs
Authors: Yuan Lifeng , Zhou Feng , Jin Yulei , Yang Qunsi , Xu Weizong , Ren Fangfang , Zhou Dong , Chen Dunjun , Zhang Rong , Zheng Youdou , Lu Hai
Published: July 2022

Overvoltage ruggedness is an essential reliability requirement for non-avalanche AlGaN/GaN power devices against inductive transient spikes in the OFF-state breakdown events. In this work, we first report the 3rd-quadrant (i.e. source-to-drain reverse operation) overvoltage ruggedness of the p-gate GaN high-electron-mobility transistors (HEMTs) by performing static current–voltage (I–V) sweeps and dynamic unclamped inductive switching (UIS) experiments. Both experimental results reveal an inferior breakdown performance of the device under 3rd-quadrant blocking conditions, including a low static voltage of 57 V and a dynamic breakdown voltage (BV) of 155 V. In particular, this transient voltage is evidently degraded from 155 V to 114 V (i.e. a 26% reduction) by increasing the load current, which is significantly different from the stable BV (1.4 kV) achieved in the 1st-quadrant dynamic breakdown. Such unusual degradation behavior can be explained by the trapping-related carrier transport mechanism, which is supported by temperature-dependent breakdown characteristics. Further numerical simulations, de-capsulation failure analyses and repeated UIS experiments are carried out to study the failure mechanism and gain insight into the overvoltage capability of the device. These results suggest that the rational design of the p-gate GaN HEMTs with the desired 3rd-quadrant overvoltage ruggedness requires careful consideration, especially in reverse conduction events.