bluuebunny/crossref_metadata_2025 huggingface dataset:
Serine starvation silences estrogen receptor signaling through histone hypoacetylation
Authors: Li Albert M. , He Bo , Karagiannis Dimitris , Li Yang , Jiang Haowen , Srinivasan Preethi , Ramirez Yaniel , Zhou Meng-Ning , Curtis Christina , Gruber Joshua J. , Lu Chao , Rankin Erinn B. , Ye Jiangbin
Published: September 2023

Loss of estrogen receptor (ER) pathway activity promotes breast cancer progression, yet how this occurs remains poorly understood. Here, we show that serine starvation, a metabolic stress often found in breast cancer, represses estrogen receptor alpha (ERα) signaling by reprogramming glucose metabolism and epigenetics. Using isotope tracing and time-resolved metabolomic analyses, we demonstrate that serine is required to maintain glucose flux through glycolysis and the TCA cycle to support acetyl-CoA generation for histone acetylation. Consequently, limiting serine depletes histone H3 lysine 27 acetylation (H3K27ac), particularly at the promoter region of ER pathway genes including the gene encoding ERα,
ESR1
. Mechanistically, serine starvation impairs acetyl-CoA-dependent gene expression by inhibiting the entry of glycolytic carbon into the TCA cycle and down-regulating the mitochondrial citrate exporter SLC25A1, a critical enzyme in the production of nucleocytosolic acetyl-CoA from glucose. Consistent with this model, total H3K27ac and ERα expression are suppressed by SLC25A1 inhibition and restored by acetate, an alternate source of acetyl-CoA, in serine-free conditions. We thus uncover an unexpected role for serine in sustaining ER signaling through the regulation of acetyl-CoA metabolism.
Highly selective synthesis of surface Fe
IV
=O with nanoscale zero-valent iron and chlorite for efficient oxygen transfer reactions
Authors: Li Meiqi , Li Hao , Ling Cancan , Shang Huan , Wang Hui , Zhao Shengxi , Liang Chuan , Mao Chengliang , Guo Furong , Zhou Biao , Ai Zhihui , Zhang Lizhi
Published: September 2023

High-valent iron-oxo species (Fe
IV
=O) has been a long-sought-after oxygen transfer reagent in biological and catalytic chemistry but suffers from a giant challenge in its gentle and selective synthesis. Herein, we propose a new strategy to synthesize surface Fe
IV
=O (≡Fe
IV
=O) on nanoscale zero-valent iron (nZVI) using chlorite (ClO
2
–
) as the oxidant, which possesses an impressive ≡Fe
IV
=O selectivity of 99%. ≡Fe
IV
=O can be energetically formed from the ferrous (Fe
II
) sites on nZVI through heterolytic Cl–O bond dissociation of ClO
2
–
via a synergistic effect between electron-donating surface ≡Fe
II
and proximal electron-withdrawing H
2
O, where H
2
O serves as a hydrogen-bond donor to the terminal O atom of the adsorbed ClO
2
–
thereby prompting the polarization and cleavage of Cl-O bond for the oxidation of ≡Fe
II
toward the final formation of ≡Fe
IV
=O. With methyl phenyl sulfoxide (PMS
16
O) as the probe molecule, the isotopic labeling experiment manifests an exclusive
18
O transfer from Cl
18
O
2
–
to PMS
16
O
18
O mediated by ≡Fe
IV
=
18
O. We then showcase the versatility of ≡Fe
IV
=O as the oxygen transfer reagent in activating the C-H bond of methane for methanol production and facilitating selective triphenylphosphine oxide synthesis with triphenylphosphine. We believe that this new ≡Fe
IV
=O synthesis strategy possesses great potential to drive oxygen transfer for efficient high-value-added chemical synthesis.
Interfacial Cherenkov radiation from ultralow-energy electrons
Authors: Gong Zheng , Chen Jialin , Chen Ruoxi , Zhu Xingjian , Wang Chan , Zhang Xinyan , Hu Hao , Yang Yi , Zhang Baile , Chen Hongsheng , Kaminer Ido , Lin Xiao
Published: September 2023

Cherenkov radiation occurs only when a charged particle moves with a velocity exceeding the phase velocity of light in that matter. This radiation mechanism creates directional light emission at a wide range of frequencies and could facilitate the development of on-chip light sources except for the hard-to-satisfy requirement for high-energy particles. Creating Cherenkov radiation from low-energy electrons that has no momentum mismatch with light in free space is still a long-standing challenge. Here, we report a mechanism to overcome this challenge by exploiting a combined effect of interfacial Cherenkov radiation and umklapp scattering, namely the constructive interference of light emission from sequential particle–interface interactions with specially designed (umklapp) momentum-shifts. We find that this combined effect is able to create the interfacial Cherenkov radiation from ultralow-energy electrons, with kinetic energies down to the electron-volt scale. Due to the umklapp scattering for the excited high-momentum Bloch modes, the resulting interfacial Cherenkov radiation is uniquely featured with spatially separated apexes for its wave cone and group cone.
Autism- and epilepsy-associatedEEF1A2mutations lead to translational dysfunction and altered actin bundling
Authors: Mohamed Muhaned S. , Klann Eric
Published: September 2023

Protein synthesis is a fundamental cellular process in neurons that is essential for synaptic plasticity and memory consolidation. Here, we describe our investigations of a neuron- and muscle-specific translation factor,eukaryoticElongationFactor1a2(eEF1A2), which when mutated in patients results in autism, epilepsy, and intellectual disability. We characterize threeEEF1A2patient mutations, G70S, E122K, and D252H, and demonstrate that all three mutations decrease de novo protein synthesis and elongation rates in HEK293 cells. In mouse cortical neurons, theEEF1A2mutations not only decrease de novo protein synthesis but also alter neuronal morphology, regardless of endogenous levels of eEF1A2, indicating that the mutations act via a toxic gain of function. We also show that eEF1A2 mutant proteins display increased tRNA binding and decreased actin-bundling activity, suggesting that these mutations disrupt neuronal function by decreasing tRNA availability and altering the actin cytoskeleton. More broadly, our findings are consistent with the idea that eEF1A2 acts as a bridge between translation and the actin cytoskeleton, which is essential for proper neuron development and function.
Mixed, nonclassical behavior in a classic allosteric protein
Authors: Sapienza Paul J. , Bonin Jeffrey P. , Jinasena H.P. Dinusha , Li Kelin , Dieckhaus Henry , Popov Konstantin I. , Aubé Jeffrey , Lee Andrew L.
Published: September 2023

Allostery is a major driver of biological processes requiring coordination. Thus, it is one of the most fundamental and remarkable phenomena in nature, and there is motivation to understand and manipulate it to a multitude of ends. Today, it is often described in terms of two phenomenological models proposed more than a half-century ago involving only T(tense) or R(relaxed) conformations. Here, methyl-based NMR provides extensive detail on a dynamic T to R switch in the classical dimeric allosteric protein, yeast chorismate mutase (CM), that occurs in the absence of substrate, but only with the activator bound. Switching of individual subunits is uncoupled based on direct observation of mixed TR states in the dimer. This unique finding excludes both classic models and solves the paradox of a coexisting hyperbolic binding curve and highly skewed substrate-free T–R equilibrium. Surprisingly, structures of the activator-bound and effector-free forms of CM appear the same by NMR, providing another example of the need to account for dynamic ensembles. The apo enzyme, which has a sigmoidal activity profile, is shown to switch, not to R, but to a related high-energy state. Thus, the conformational repertoire of CM does not just change as a matter of degree depending on the allosteric input, be it effector and/or substrate. Rather, the allosteric model appears to completely change in different contexts, which is only consistent with modern ensemble–based frameworks.
Light cues induce protective anticipation of environmental water loss in terrestrial bacteria
Authors: Hatfield Bridget M. , LaSarre Breah , Liu Meiling , Dong Haili , Nettleton Dan , Beattie Gwyn A.
Published: September 2023

The ecological significance of light perception in nonphotosynthetic bacteria remains largely elusive. In terrestrial environments, diurnal oscillations in light are often temporally coupled to other environmental changes, including increased temperature and evaporation. Here, we report that light functions as an anticipatory cue that triggers protective adaptations to tolerate a future rapid loss of environmental water. We demonstrate this photo-anticipatory stress tolerance in leaf-associated
Pseudomonas syringae
pv. syringae (
Pss
) and other plant- and soil-associated pseudomonads. We found that light influences the expression of 30% of the
Pss
genome, indicating that light is a global regulatory signal, and this signaling occurs almost entirely via a bacteriophytochrome photoreceptor that senses red, far-red, and blue wavelengths. Bacteriophytochrome-mediated light control disproportionally up-regulates water-stress adaptation functions and confers enhanced fitness when cells encounter light prior to water limitation. Given the rapid speed at which water can evaporate from leaf surfaces, such anticipatory activation of a protective response enhances fitness beyond that of a reactive stress response alone, with recurring diurnal wet–dry cycles likely further amplifying the fitness advantage over time. These findings demonstrate that nonphotosynthetic bacteria can use light as a cue to mount an adaptive anticipatory response against a physiologically unrelated but ecologically coupled stress.
Hedonic eating, obesity, and addiction result from increased neuropeptide Y in the nucleus accumbens during human brain evolution
Authors: Raghanti Mary Ann , Miller Elaine N. , Jones Danielle N. , Smith Heather N. , Munger Emily L. , Edler Melissa K. , Phillips Kimberley A. , Hopkins William D. , Hof Patrick R. , Sherwood Chet C. , Lovejoy C. Owen
Published: September 2023

The nucleus accumbens (NAc) is central to motivation and action, exhibiting one of the highest densities of neuropeptide Y (NPY) in the brain. Within the NAc, NPY plays a role in reward and is involved in emotional behavior and in increasing alcohol and drug addiction and fat intake. Here, we examined NPY innervation and neurons of the NAc in humans and other anthropoid primates in order to determine whether there are differences among these various species that would correspond to behavioral or life history variables. We quantified NPY-immunoreactive axons and neurons in the NAc of 13 primate species, including humans, great apes, and monkeys. Our data show that the human brain is unique among primates in having denser NPY innervation within the NAc, as measured by axon length density to neuron density, even after accounting for brain size. Combined with our previous finding of increased dopaminergic innervation in the same region, our results suggest that the neurochemical profile of the human NAc appears to have rendered our species uniquely susceptible to neurophysiological conditions such as addiction. The increase in NPY specific to the NAc may represent an adaptation that favors fat intake and contributes to an increased vulnerability to eating disorders, obesity, as well as alcohol and drug dependence. Along with our findings for dopamine, these deeply rooted structural attributes of the human brain are likely to have emerged early in the human clade, laying the groundwork for later brain expansion and the development of cognitive and behavioral specializations.
Photographing Chinese childhood
Authors: Medhurst Jessica
Published: September 2023

Photography was brought to China from Europe in the 1840s, whereby the narratives these pictures told about the country
were largely framed in pseudo-colonial terms. Although Western photographers – including Isabella Bird, Jules Itier, James Ricalton
and John Thomson – consistently characterized the camera as showing China in the most faithful way possible, these apparently
authentic representations were steeped in established Western tropes of what China was already assumed to look like. This chapter uses
this backdrop to interrogate what these photographs say about Chinese childhood, which, in the literature of the period, is
characterized as both a natural and universal condition, and as something that is incompatible with being Chinese. The chapter
discusses the switching between what the photographs’ commentaries claim the children are like and what they
should be like, as well as offering alternative readings of childhood in the pictures, focusing on ideas of
innocence, formality, and playfulness. It concludes by demonstrating the ways in which these narratives still continue in Anglophone
texts today through publication, exhibition, and academic discourse.
Soviet socialist su(pe)rrealism for children
Authors: Boškovic Aleksandar , Morse Ainsley
Published: September 2023

This chapter posits a kind of Soviet Surrealism, or “su(pe)rrealism”, in photo-illustrated Soviet children’s literature of
the interwar period. The techniques of manipulating photo-images that carried out the montage in a single frame were widely employed
in photo-illustrated children’s books published in the late 1930s. Unlike earlier Soviet children’s books, which mostly employed
photography toward “capturing real life” and promoting mass education, these late-1930s photobooks conjured a fairy-tale wonderland in
which reality is somewhat bracketed and objects are given visible agency. Instead of the “baring of the device” typical of the 1920s,
later graphic artists sought to hide the device in order to increase the naturalistic effect of photo-montaged
representations. These photographic “deformations,” effected by retouching and manipulations of scale, rendered the world of objects –
the so-called “real” world surrounding children – subtly uncanny, subject to distortion and, thus, distinctively surrealist. This turn
toward the surreal seems curiously at odds yet consonant with the totalizing culture of Stalinism – hence our suggestion of
“super-real” as an alternative designation.
From the “Children of all Lands Stories” to the “Enfants du monde” collection
Authors: Le Guen Laurence
Published: September 2023

Although it does not appear under this name on the shelves of bookshops or libraries, the literary genre of the
phototextual country portrait has an effective reality in children’s literature, with a wide variety of publications. These works are
regularly published in periods when children’s books are seen as the engine of a new pacifist humanism. They flourished in different
parts of the world after the two world wars, all carrying the same message of hope, transmitting the conviction that the world, in its
diversity and complexity, is one: our world. This article juxtaposes the works of the 1920s series “Children of all Lands Stories”, by
the American photographer and filmmaker Madeline Brandeis, with those of the “Enfants du monde” collection, carried by photographs by
French photographer Dominique Darbois, to discuss how photographs and texts are combined to offer the young reader new views of the
Other and thus promote peace between peoples through children’s literature.
In and out of focus
Authors: Druker Elina
Published: September 2023

Anna Riwkin was a Russian-Swedish photographer who contributed significantly to the growing use of photographs in
children’s picturebooks during the second half of the twentieth century. This chapter investigates the photographic techniques and
genres in Riwkin’s works for children. Using a selection of reportage portraits and photo books by her as a starting point, the
chapter discusses the relationship between words and images in photo narratives for children. During the early part of her career,
Riwkin specialized in portraits and dance photography and during the 1930s, she added journalistic work to her repertoire. Traces of
all these genres are evident in her photographic picturebooks. They express realist and documentary ambitions, aiming to capture the
perspective of the individuals portrayed, but at the same time their images are staged and embedded in a narrative, which affects
their expression and style. Riwkin’s choice to work with children’s literature also raises questions about women photographers’
position within the field of photography. How were women photographers perceived within different types of photography? Should the aim
to work with children’s books be understood in relation to the artist’s socially engaged approach or was it seen as particularly
suitable for a female photographer? Since Riwkin was one of the pioneering women photographers in Europe, the reception of her work is
of utmost interest, both when it comes to contemporary critique and the perception of her work in later photographic research.
Politics, art, and pedagogy in Edith Tudor-Hart’s photographs of children
Authors: Reynolds Kimberley
Published: September 2023

Edith Tudor-Hart, a photographer working in Britain from the 1930s to the 1950s, became exceptionally good at
photographing children. Her final series of images, published in a classroom text called Moving and
Growing (1952), were created through a collaborative method she developed
by combining her teaching experience and her training as an artist with her political conviction that photography is a democratic
medium. The results are dynamic photographs that capture children moving, risking and creating. Shortly after Moving and
Growing was published, Tudor-Hart abandoned photography and destroyed her catalogue of negatives fearing she was about to
be prosecuted as a spy. As a consequence, her work was largely forgotten, but her images and working methods deserve to be recalled
and studied. In our highly visual age, Edith Tudor-Hart’s powerful images have much to say about the relationship between photography
and images of childhood.
The mirror and multiplicity
Authors: Capshaw Katharine
Published: September 2023

Black creators in the 1970s used the photographic picturebook to recreate black identity and history. Whether tethering
images to the logic of the alphabet, as do Yusef Iman and Jean Carey Bond, or deploying images to disrupt narratives of American
history, as do Toni Morrison and June Jordan, creators recognized the multiple aesthetic and political possibilities engendered by an
assemblage of images. The photograph seeks to mirror by fixing places and people on the page; and some narratives productively pull
against closure, embracing instead the ongoing process of knowing black history through interpreting the sequence of photographs.
The Linguistic Landscape of the war
Authors: Baranova Vlada
Published: September 2023

Being immersed in a covert conflict within a censored society, the Linguistic Landscape provides valuable insights
into the dynamics of multilingual communication during war. Following the full-scale Russian invasion of Ukraine, political
involvement among ethnic minority groups in Russia has experienced a surge. The use of minority languages signifies a hidden but
significant form of protest, empowering ethnic minorities to assert their agency and political claims. Through an examination of
anti- and pro-war signs in minority languages and interviews with language activists, this study explores how these languages are
employed within the LL, revealing the motivations and attitudes of their authors. Minority languages in anti-war signs serve as
secret codes while also personalizing protests and appealing to group solidarity. However, pro-war signs also evoke solidarity and
ethnic values. Analysis of the anti- and pro-war signs illustrates their connection to other texts in minority languages,
referencing discourses and ethnic symbols within the community of speakers of a minority language.
The pragmatics of advice-giving in the media discourse
Authors: Tang Chihsia
Published: September 2023

This study investigated how the gender of the contestants in TV talent competitions affects male and female
judges’ management of their advice, exemplified by evaluative talks in two Taiwan-based talent contests. In addition to the
pragmatic configuration of the advising acts, the internal and external modifiers of the advising speech events were also analyzed
in an attempt to gain insights into whether and how the advice messages are instrumental in the construction of gender identities.
Results showed that deviating from the stereotypical gendered style of communication, the female judges utilized significantly
fewer politeness mechanisms than did their male counterparts to moderate their advice. Besides, the psychological needs and face
want of the male and female advice-receivers remarkably influenced the discursive moves of the given advice comments. These
findings suggested that in the public media discourse, the speech context outweighs the socially prescribed gendered styles of
communication on one’s advice-giving behavior.
Antigen-presenting autoreactive B cells activate regulatory T cells and suppress autoimmune arthritis in mice
Authors: Aoun Mike , Coelho Ana , Krämer Alexander , Saxena Amit , Sabatier Pierre , Beusch Christian Michel , Lönnblom Erik , Geng Manman , Do Nhu-Nguyen , Xu Zhongwei , Zhang Jingdian , He Yibo , Romero Castillo Laura , Abolhassani Hassan , Xu Bingze , Viljanen Johan , Rorbach Joanna , Fernandez Lahore Gonzalo , Gjertsson Inger , Kastbom Alf , Sjöwall Christopher , Kihlberg Jan , Zubarev Roman A. , Burkhardt Harald , Holmdahl Rikard
Published: September 2023

B cells undergo several rounds of selection to eliminate potentially pathogenic autoreactive clones, but in contrast to T cells, evidence of positive selection of autoreactive B cells remains moot. Using unique tetramers, we traced natural autoreactive B cells (C1-B) specific for a defined triple-helical epitope on collagen type-II (COL2), constituting a sizeable fraction of the physiological B cell repertoire in mice, rats, and humans. Adoptive transfer of C1-B suppressed arthritis independently of IL10, separating them from IL10-secreting regulatory B cells. Single-cell sequencing revealed an antigen processing and presentation signature, including induced expression of CD72 and CCR7 as surface markers. C1-B presented COL2 to T cells and induced the expansion of regulatory T cells in a contact-dependent manner. CD72 blockade impeded this effect suggesting a new downstream suppressor mechanism that regulates antigen-specific T cell tolerization. Thus, our results indicate that autoreactive antigen-specific naïve B cells tolerize infiltrating T cells against self-antigens to impede the development of tissue-specific autoimmune inflammation.
IL-22: Immunity’s bittersweet symphony
Authors: Duan Jinzhi , Matute Juan D. , Blumberg Richard S.
Published: September 2023

Epithelial cells play a crucial role in barrier defense. Here, Moniruzzaman et al. (2023. J. Exp. Med.https://doi.org/10.1084/jem.20230106) discovered that interleukin-22 (IL-22) represses MHC class II expression by epithelial cells with an opposite impact on chronic inflammatory disease and viral infection.
Design and analysis of ultra-low moment noise flexure pivot in space gravitational wave detectors
Authors: Shi Zhibin , Liu Yanfu , Zhao Zijing , Wang Zihan , Yan Yong , Fan Lei , Li Zizheng , Zhao Hongchao
Published: September 2023

To control the pointing accuracy of the telescope in the space gravitational wave detector at the nano-radian level, it is essential to design a flexure pivot with extremely low rotational moment nonlinearity during rotation. This study derives the theoretical equation of the nonlinear rotational moment of flexure pivot based on the beam bending strain energy equation and completes the design of ultra-low moment noise flexure pivot by integrating the structural form of conventional cross-spring flexure pivot. The nonlinear moment noise distribution in the frequency domain of three kinds of flexure pivots is then compared regarding TianQin’s circular high orbits. Then the relevant finite element simulation analysis will be performed for the flexure pivot structures, respectively, to ensure the accuracy of its rotational stiffness model and verify the correctness of nonlinear moment theory optimization through physical experiments. The results show that the optimized flexure pivot can effectively reduce the nonlinearity, and basically meet the nonlinear moment requirements in space gravitational wave detection.
Geometry of static perfect fluid space-time
Authors: Costa J , Diógenes R , Pinheiro N , Ribeiro Jr E
Published: September 2023

In this article, we investigate the geometry of static perfect fluid space-time (SPFST) on compact manifolds with boundary. We use the generalized Reilly’s formula to establish a geometric inequality for a SPFST involving the area of the boundary and its volume. Moreover, we obtain new boundary estimates for SPFST. One of the boundary estimates is obtained in terms of the Brown–York mass and another one related to the first eigenvalue of the Jacobi operator. In addition, we provide a new (simply connected) counterexample to the Cosmic no-hair conjecture for arbitrary dimension

n
⩾
4.
Development and experimental investigation of a high-precision capacitive displacement transducer of the inertial sensor for TianQin
Authors: Wang Chengrui , Bai Yanzheng , Hu Ming , Li Duo , Li Ke , Ouyang Chaoli , Qu Shaobo , Xiao Chunyu , Yang Xiaotian , Zhou Annan , Zhou Zebing
Published: September 2023

Capacitive sensing electronics are critical to space gravitational wave detection missions, providing the test mass motion information for the inertial sensor’s non-sensitive axis control and the drag-free control of the satellite. For the TianQin mission, the capacitive sensor requirement is

6.9
×

10

−
7

p
F
H

z

−
1

/

2

at 6 mHz, corresponding to a displacement noise of

1.7

n
m
H

z

−
1

/

2

. This paper presents the system design scheme, noise analysis, and performance testing of the capacitive sensor for the TianQin mission. Based on the previous work of our group, a capacitive sensing scheme based on a transformer bridge and modulation–demodulation is adopted. A transformer with a better high LQ product is fabricated, and the preamplifier current noise is reduced to further improve the performance above mHz. The amplitude stability of the AC carrier and the performance of the lock-in amplifier circuit are further improved to reduce the low-frequency

1

/

f

noise at

m
H
z

and below. Finally, a capacitive sensor prototype is developed and tested, the experimental results show that the capacitance measurement noise is better than

3
×

10

−
7

p
F
H

z

−
1

/

2

above 1 mHz and better than

6
×

10

−
7

p
F
H

z

−
1

/

2

at about

0.1

mHz

, which meets the overall performance requirement of the TianQin mission.
Derivation of MOND from Hossenfelder–Verlinde gravity
Authors: Yoon Youngsub
Published: September 2023

Verlinde proposed emergent gravity, which naturally explains the Tully–Fisher relation, an empirical relation in galaxy rotation curves. Inspired by this theory, Hossenfelder constructed a covariant formulation of Verlinde’s emergent gravity. In this work, we show that the equation of motion gains an extra acceleration in addition to the usual geodesic equation, according to Hossenfelder’s theory. Moreover, we show that the extra acceleration is precisely the square root of the Newtonian gravitational acceleration if the mass of the imposter field is negligible, thus completing the proof that Hossenfelder’s theory reduces to modified Newtonian dynamics (MOND) and determining which version of MOND it reduces to. We also obtain the value of L in Hossenfelder–Verlinde gravity theory, which is a constant, contrary to what Hossenfelder claimed. Finally, we suggest how the Newtonian limit that suitably describes our observations in Solar System is recovered in Hossenfelder’s theory, by considering the mass of the imposter field.
A large-momentum-transfer matter-wave interferometer to measure the effect of gravity on positronium
Authors: Vinelli G , Castelli F , Ferragut R , Romé M , Sacerdoti M , Salvi L , Toso V , Giammarchi M , Rosi G , Tino G M
Published: September 2023

This paper reports the study of a new interferometric configuration to measure the effect of gravity on positronium. A Mach–Zehnder matter-wave interferometer has been designed to operate with single-photon transitions and to transfer high momentum to a 200 eV positronium beam. The work shows the results and methods used to simulate the interferometer and estimate the operating parameters and the time needed to perform the experiment. It has been estimated that within less than 1 year, the acquisition time is sufficient to achieve a 10% accuracy level in measuring positronium gravitational acceleration, even with a poorly collimated beam, which is significant for theoretical models describing matter–antimatter symmetry. These results pave the way for single photon transition large momentum transfer interferometry with fast atomic beams, which is particularly useful for studies with antimatter and unstable atoms.
Underwater acoustic self-focusing and bending in conformal Mikaelian lens by pentamode metafluid
Authors: Sun Zhaoyong , Zhao Liuxian , Yang Jun
Published: September 2023

In this paper, we present the design of an arc-shaped Mikaelian lens using conformal transformation acoustics. We have derived the propagation trajectory equation for vertically incident rays within the lens. The ray trajectories inside the designed lens exhibit the feature of self-focusing as well as of deflection of the propagation direction. The microstructure design of the lens is realized using pentamode material unit cells, which provide the necessary property for underwater acoustic wave manipulation. The simulation results demonstrate that the designed lens has a good self- focusing effect and can deflect the propagation direction of incident waves at the same time. The pentamode conformal Mikaelian lens shows potential applications in underwater imaging, detection and communication.
Modeling of reactive species interphase transport in plasma jet impinging on water
Authors: Kamidollayev Tlegen , Trelles Juan Pablo
Published: September 2023

The interaction between low-temperature atmospheric pressure plasma and water is of primary relevance to an increasing number of applications, from water treatment to medicine. The interaction between an argon plasma jet and water is investigated using a three-dimensional (3D) time-dependent computational model encompassing turbulent gas flow and induced liquid motion, gas–water interface dynamics, multiphase species transport, and gas- and liquid-phase chemical reactions. A single-field approach based on the volume-of-fluid (VoF) method together with conditional volume averaging (CVA), is used to consistently describe the dynamics of the interface together with interfacial reactive mass transfer. Three CVA-based interface species transport models, based on arithmetic, harmonic, and unified mixture species diffusivities, are evaluated. Simulations of a plasma jet impinging on water at different gas flow rates are presented. The resulting deformation of the interface and the production and accumulation of hydrogen peroxide, reactive oxygen, and nitrogen species corroborate prior findings in the research literature showing that higher jet velocities and associated increased interface deformation led to the enhanced transport of reactive species across the plasma-water interface. The VoF-CVA approach appears promising for the modeling of general plasma-liquid multiphase systems.
Detailed pathway for a fast low-temperature synthesis of strongly thermochromic W-doped VO2films with a low transition temperature
Authors: Vlček Jaroslav , Kaufman Michal , Pajdarová Andrea Dagmar , Haviar Stanislav , Čerstvý Radomír , Houška Jiří , Farahani Mina
Published: September 2023

We report the discharge characteristics, and population of chosen atomic neutral (V, O and Ar) and ionic (V+, V2+, O+and Ar+) species in the discharge during low-temperature (350 °C) depositions of W-doped VOxfilms onto a 170 nm thick Y-stabilized ZrO2layer on a 1 mm thick conventional soda-lime glass. The depositions were performed using reactive deep oscillation magnetron sputtering with a pulsed O2flow control and to-substrate O2injection into a high-density plasma in front of the sputter V-W target. The pre-selected critical values of the oxygen partial pressure were in the range from 82 mPa to 92 mPa. Optical emission spectroscopy proved a relatively high density of O atoms in front of the substrate, which is important for production of the W-doped VO2films. It was found that setting of the amount of O2in the gas mixture determines not only the elemental and phase composition of the films and their deposition rate but also the crystallinity of the thermochromic VO2phase in them. The crystalline W-doped VO2films with a low transition temperature of 28 °C exhibited a high modulation of the solar energy transmittance of 8.9%. The results are important for further improvement of this new scalable sputter deposition technique for a fast (53 nm min−1at a target-substrate distance of 100 mm in this work) low-temperature synthesis of high-performance durable thermochromic VO2-based multilayer coatings designed for smart-window applications.
An interpretable health indicator for bearing condition monitoring based on semi-supervised autoencoder latent space variance maximization
Authors: Chen Xieyi , Wang Yi , Meng Lihua , Qin Yi , Tang Baoping
Published: September 2023

Effective health indicator (HI) construction can help equipment managers detect the abnormal state of rotating machinery quickly. However, although the current deep learning-based HI construction methods have good life prediction value, most of them lose the ability to detect device anomalies and little work has been done on model interpretability. Therefore, an interpretable HI construction method based on semi-supervised autoencoder (AE) latent space variance maximization (SSALSVM) was proposed to monitor the health status of bearings. In order to fully excavate degradation features inside the device and make the model focus on the encoding process, a deep convolutional neural network (DCNN) is used as the encoding layer, while only a layer of fully-connected layer is used as the decoding layer. In addition, to enable the latent space to capture the device early degradation point (EDP) successfully, an auxiliary layer is added to the output of the encoder layer. Simultaneously, for improving the sensitivity of the indicator to capture equipment abnormal state and highlight the difference between equipment health state and degradation state, the constraint of variance maximization is added into the latent space. The model optimizing process was presented by observing the projected variance of the test set in latent space of each epoch model. The validity of the proposed HI was verified by comparison experiments on two datasets.
Study on the optimization of the classification method of rolling bearing fault type and damage degree based on SFO–VMD
Authors: Jing Laixing , Bian Jun , He Xiangdong , Liu Yanqiu
Published: September 2023

Currently, rolling bearings operate in harsh environments, resulting in acquired signals with a low signal-to-noise ratio. In light of this, this paper proposes an improved variational modal decomposition(VMD) combined with refine composite multi-scale fuzzy entropy (RCMFE) and linear support vector machine (LSVM) for fault diagnosis. Firstly, the sailfish optimization (SFO) algorithm is employed to optimize the important parameter combinations in the VMD algorithm, using the envelope entropy as its objective function. The analysis includes both simulated and real measured signals with varying signal-to-noise ratios. The results demonstrate that, compared to traditional manual parameter setting and empirical modal decomposition methods, this approach effectively addresses the parameter setting issue of VMD in the signal decomposition process. Additionally, it successfully eliminates noise to extract the fault characteristic signal hidden within the original signal. Secondly, the RCMFE algorithm is introduced to overcome the problem of commonly used dimensioned and dimensionless indicators being influenced by load and speed when used as characteristic indicators. By analyzing the influence of load and speed on the RCMFE value, the results demonstrate its strong stability as a feature indicator, unaffected by these factors. For the intelligent classification of failure type and damage degree, LSVM is chosen as the classification method. Analysis results indicate that the distribution characteristics of RCMFE values align better with LSVM compared to the common radial basis function support vector machine, resulting in a significant improvement in diagnosis accuracy.
Accurate near-wall measurements in wall bounded flows with optical flow velocimetry via an explicit no-slip boundary condition
Authors: Jassal Gauresh Raj , Schmidt Bryan E
Published: September 2023

High fidelity near-wall velocity measurements in wall bounded fluid flows continue to pose a challenge and the resulting limitations on available experimental data cloud our understanding of the near-wall velocity behavior in turbulent boundary layers. One of the challenges is the spatial averaging and limited spatial resolution inherent to cross-correlation-based particle image velocimetry (PIV) methods. To circumvent this difficulty, we implement an explicit no-slip boundary condition in a wavelet-based optical flow velocimetry (wOFV) method. It is found that the no-slip boundary condition on the velocity field can be implemented in wOFV by transforming the constraint to the wavelet domain through a series of algebraic linear transformations, which are formulated in terms of the known wavelet filter matrices, and then satisfying the resulting constraint on the wavelet coefficients using constrained optimization for the optical flow functional minimization. The developed method is then used to study the classical problem of a turbulent channel flow using synthetic data from a direct numerical simulation (DNS) and experimental particle image data from a zero pressure gradient, high Reynolds number turbulent boundary layer. The results obtained by successfully implementing the no-slip boundary condition are compared to velocity measurements from wOFV without the no-slip condition and to a commercial PIV code, using the velocity from the DNS as ground truth. It is found that wOFV with the no-slip condition successfully resolves the near-wall profile with enhanced accuracy compared to the other velocimetry methods, as well as other derived quantities such as wall shear and turbulent intensity, without sacrificing accuracy away from the wall, leading to state of the art measurements in the

y
+

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1

region of the turbulent boundary layer when applied to experimental particle images.
Intelligent prediction of rolling bearing remaining useful life based on probabilistic DeepAR-Transformer model
Authors: Deng Linfeng , Li Wei , Zhang Weiqiang
Published: September 2023

Remaining useful life (RUL) prediction for rolling bearings requires highly accurate and stable long-term prediction capabilities in equipment health management, which demands that the prediction model has strong data reasoning and regression performance. However, it is difficult to accurately capture long-term dependencies via traditional convolutional neural network because the information loss and insufficient analysis are unavoidable during the feature extraction process. An end-to-end time series forecasting method called D-former for RUL prediction of rolling bearings is proposed in this paper. The method mainly consists of DeepAR and a multi-layer encoder, so it is able to extract degradation features directly from the original signal. This method has the following salient features: (1) the designed multi-head attention mechanism can highlight important feature information and realize parallel computing, so the method is extremely suitable for processing long-term time series; (2) the important time feature information is rearranged through DeepAR, so the method has the excellent domain adaptability, and it can achieve accurate prediction of rolling bearing RUL under different working conditions. The verification experiment was implemented on the IEEE PHM 2012 dataset and the XJTU-SY bearing dataset. The experimental results show that the proposed D-former method is actually superior to the existing mainstream RUL prediction methods.
A PTV-based feature-point matching algorithm for binocular stereo photogrammetry
Authors: Han Yukun , Pan Chong , Cheng Zepeng , Xu Yang
Published: September 2023

The procedure of feature matching is one of the most important components in binocular or multi-ocular stereoscopic photogrammetry. In this paper, a feature-point matching algorithm based on the technique of particle tracking velocimetry is proposed for the scenario of measuring complex surface morphology by dense-point three-dimensional reconstruction. The core idea is to mix the epipolar-line constraint of line-of-sight (LOS) with the measure of a global similarity pairing and estimate the depth of each feature point in an iterative way. Experimental test is conducted to verify the algorithm performance by measuring the surface topology of a wave-like model. The result demonstrates that the feature-point matching algorithm is superior to traditional LOS method in terms of accuracy and robustness. Moreover, replacing the first module of coarse matching in the proposed algorithm by LOS will save the computational cost significantly without sacrificing the measurement accuracy.
MARGANVAC: metal artifact reduction method based on generative adversarial network with variable constraints
Authors: Li Guang , Ji Longyin , You Chenyu , Gao Shuai , Zhou Langrui , Bai Keshu , Luo Shouhua , Gu Ning
Published: September 2023

Objective. Metal artifact reduction (MAR) has been a key issue in CT imaging. Recently, MAR methods based on deep learning have achieved promising results. However, when deploying deep learning-based MAR in real-world clinical scenarios, two prominent challenges arise. One limitation is the lack of paired training data in real applications, which limits the practicality of supervised methods. Another limitation is that image-domain methods suitable for more application scenarios are inadequate in performance while end-to-end approaches with better performance are only applicable to fan-beam CT due to large memory consumption. Approach. We propose a novel image-domain MAR method based on the generative adversarial network with variable constraints (MARGANVAC) to improve MAR performance. The proposed variable constraint is a kind of time-varying cost function that can relax the fidelity constraint at the beginning and gradually strengthen the fidelity constraint as the training progresses. To better deploy our image-domain supervised method into practical scenarios, we develop a transfer method to mimic the real metal artifacts by first extracting the real metal traces and then adding them to artifact-free images to generate paired training data. Main results. The effectiveness of the proposed method is validated in simulated fan-beam experiments and real cone-beam experiments. All quantitative and qualitative results demonstrate that the proposed method achieves superior performance compared with the competing methods. Significance. The MARGANVAC model proposed in this paper is an image-domain model that can be conveniently applied to various scenarios such as fan beam and cone beam CT. At the same time, its performance is on par with the cutting-edge dual-domain MAR approaches. In addition, the metal artifact transfer method proposed in this paper can easily generate paired data with real artifact features, which can be better used for model training in real scenarios.
3D modeling of positive streamers in air with inhomogeneous density
Authors: Guo Baohong , Ebert Ute , Teunissen Jannis
Published: September 2023

We study the effect of an inhomogeneous gas density on positive streamer discharges in air using a 3D fluid model with stochastic photoionization, generalizing earlier work with a 2D axisymmetric model by Starikovskiy and Aleksandrov (2019 Plasma Sources Sci. Technol.
28 095022). We consider various types of planar and (hemi)spherical gas density gradients. Streamers propagate from a region of density

n

0

towards a region of higher or lower gas density

n

1

, where

n

0

corresponds to

300

K

and

1

b
a
r

. We observe that streamers can always propagate into a region with a lower gas density. When streamers enter a region with a higher gas density, branching can occur at the density gradient, with branches growing in a flower-like pattern over the gradient surface. Depending on the gas density ratio, the gradient width and other factors, narrow branches are able to propagate into the higher-density gas. In a planar geometry, we find that such propagation is possible up to a gas density slope of

3.5

n

0

/

m
m

, although this value depends on a number of conditions, such as the gradient angle. Surprisingly, a higher applied voltage makes it more difficult for streamers to penetrate into the high-density region, due to an increase of the primary streamer’s radius.
Measurements of the amplitude-dependent microwave surface resistance of an Au/Nb bilayer
Authors: Oseroff Thomas , Sun Zeming , Liepe Matthias U
Published: September 2023

Surface properties are critical to the capabilities of superconducting microwave devices. The native oxide of niobium-based devices is thought to consist of a thin normal conducting layer. To improve understanding on the importance of this layer, an attempt was made to replace it with a more easily controlled gold film. A niobium sample host microwave cavity was used to measure the surface resistance in continuous wave operation at4.0GHzand5.2GHz. Sample conditions studied include temperatures ranging from1.6Kto4.2Kwith RF magnetic fields on the sample surface ranging from∼1mTto the maximum field before the superconducting properties were lost (quench field). The nominal film thickness of the gold layer was increased from0.1nmto2.0nmin five steps to study the impact of the normal layer thickness on surface resistance on a single niobium substrate. The0.1nmfilm was found to reduce the surface resistance of the sample and to enhance the quench field. With the exception of the final step from a1.5nmgold film to2.0nm, the magnitude of the surface resistance increased substantially with gold film thickness. The nature of the surface resistance field-dependence appeared to be roughly independent from the gold layer thickness. This initial study provides new perspectives and suggests avenues for optimizing and designing surfaces for resonant cavities in particle accelerators and quantum information applications.
LIF /LIB Spectroscopy of crude oil-saturated carbonate bedrock
Authors: Parvin Parviz , Dehghanpour Hamid Reza , Faani Mohamad Mahdi , Bavali Ali , Ahmadinouri Fatemeh , Ebrahimnasab Setareh
Published: September 2023

Here, laser-induced breakdown spectroscopy (LIBS) is employed to identify constituent elements distinguishing nitrogen, oxygen, sulfur (NSO), and heavy metals in crude oil-saturated carbonate bedrock. The analysis of the spectra for both the bare rock samples and the oil-saturated specimens revealed the presence of NSO and heavy metal species (Ni, V) as the characteristics of heavy compounds in crude oil. On the other hand, the laser induced fluorescence (LIF) spectra of the crude oil are obtained over various temperatures ranging 50 °C–150 °C. The light compounds demonstrate better temperature sensitivity than the heavy compounds, leading to the identification/discrimination of those compounds.