bluuebunny/crossref_metadata_2025 huggingface dataset:
The APETALA2 homolog CaFFN regulates flowering time in pepper
Authors: Yuan Xinjie , Fang Rong , Zhou Kunhua , Huang Yueqin , Lei Gang , Wang Xiaowu , Chen Xuejun
Published: November 2021

Flowering time is an important agronomic trait that contributes to fitness in plants. However, the genetic basis of flowering time has not been extensively studied in pepper. To understand the genetics underlying flowering time, we constructed an F2 population by crossing a spontaneous early flowering mutant and a late-flowering pepper line. Using bulked segregant RNA-seq, a major locus controlling flowering time in this population was mapped to the end of chromosome 2. An APETALA2 (AP2) homolog (CaFFN) cosegregated with flowering time in 297 individuals of the F2 population. A comparison between the parents revealed a naturally occurring rare SNP (SNP2T > C) that resulted in the loss of a start codon in CaFFN in the early flowering mutant. Transgenic Nicotiana benthamiana plants with high CaFFN expression exhibited a delay in flowering time and floral patterning defects. On the other hand, pepper plants with CaFFN silencing flowered early. Therefore, the CaFFN gene acts as a flowering repressor in pepper. CaFFN may function as a transcriptional activator to activate the expression of CaAGL15 and miR156e and as a transcriptional repressor to repress the expression of CaAG, CaAP1, CaSEP3, CaSOC1, and miR172b based on a qRT-PCR assay. Direct activation of CaAGL15 by CaFFN was detected using yeast one-hybrid and dual-luciferase reporter assays, consistent with the hypothesis that CaFFN regulates flowering time. Moreover, the CaFFN gene association analysis revealed a significant association with flowering time in a natural pepper population, indicating that the CaFFN gene has a broad effect on flowering time in pepper. Finally, the phylogeny, evolutionary expansion and expression patterns of CaFFN/AP2 homologs were analyzed to provide valuable insight into CaFFN. This study increases our understanding of the involvement of CaFFN in controlling flowering time in pepper, thus making CaFFN a target gene for breeding early maturing pepper.
Grafting vigour is associated with DNA de-methylation in eggplant
Authors: Cerruti Elisa , Gisbert Carmina , Drost Hajk-Georg , Valentino Danila , Portis Ezio , Barchi Lorenzo , Prohens Jaime , Lanteri Sergio , Comino Cinzia , Catoni Marco
Published: November 2021

In horticulture, grafting is a popular technique used to combine positive traits from two different plants. This is achieved by joining the plant top part (scion) onto a rootstock which contains the stem and roots. Rootstocks can provide resistance to stress and increase plant production, but despite their wide use, the biological mechanisms driving rootstock-induced alterations of the scion phenotype remain largely unknown. Given that epigenetics plays a relevant role during distance signalling in plants, we studied the genome-wide DNA methylation changes induced in eggplant (Solanum melongena) scion using two interspecific rootstocks to increase vigour. We found that vigour was associated with a change in scion gene expression and a genome-wide hypomethylation in the CHH context. Interestingly, this hypomethylation correlated with the downregulation of younger and potentially more active long terminal repeat retrotransposable elements (LTR-TEs), suggesting that graft-induced epigenetic modifications are associated with both physiological and molecular phenotypes in grafted plants. Our results indicate that the enhanced vigour induced by heterografting in eggplant is associated with epigenetic modifications, as also observed in some heterotic hybrids.
Population genomic analysis of Aegilops tauschii identifies targets for bread wheat improvement
Authors: Gaurav Kumar , Arora Sanu , Silva Paula , Sánchez-Martín Javier , Horsnell Richard , Gao Liangliang , Brar Gurcharn S. , Widrig Victoria , John Raupp W. , Singh Narinder , Wu Shuangye , Kale Sandip M. , Chinoy Catherine , Nicholson Paul , Quiroz-Chávez Jesús , Simmonds James , Hayta Sadiye , Smedley Mark A. , Harwood Wendy , Pearce Suzannah , Gilbert David , Kangara Ngonidzashe , Gardener Catherine , Forner-Martínez Macarena , Liu Jiaqian , Yu Guotai , Boden Scott A. , Pascucci Attilio , Ghosh Sreya , Hafeez Amber N. , O’Hara Tom , Waites Joshua , Cheema Jitender , Steuernagel Burkhard , Patpour Mehran , Justesen Annemarie Fejer , Liu Shuyu , Rudd Jackie C. , Avni Raz , Sharon Amir , Steiner Barbara , Kirana Rizky Pasthika , Buerstmayr Hermann , Mehrabi Ali A. , Nasyrova Firuza Y. , Chayut Noam , Matny Oadi , Steffenson Brian J. , Sandhu Nitika , Chhuneja Parveen , Lagudah Evans , Elkot Ahmed F. , Tyrrell Simon , Bian Xingdong , Davey Robert P. , Simonsen Martin , Schauser Leif , Tiwari Vijay K. , Randy Kutcher H. , Hucl Pierre , Li Aili , Liu Deng-Cai , Mao Long , Xu Steven , Brown-Guedira Gina , Faris Justin , Dvorak Jan , Luo Ming-Cheng , Krasileva Ksenia , Lux Thomas , Artmeier Susanne , Mayer Klaus F. X. , Uauy Cristobal , Mascher Martin , Bentley Alison R. , Keller Beat , Poland Jesse , Wulff Brande B. H.
Published: November 2021

Aegilops tauschii, the diploid wild progenitor of the D subgenome of bread wheat, is a reservoir of genetic diversity for improving bread wheat performance and environmental resilience. Here we sequenced 242 Ae. tauschii accessions and compared them to the wheat D subgenome to characterize genomic diversity. We found that a rare lineage of Ae. tauschii geographically restricted to present-day Georgia contributed to the wheat D subgenome in the independent hybridizations that gave rise to modern bread wheat. Through k-mer-based association mapping, we identified discrete genomic regions with candidate genes for disease and pest resistance and demonstrated their functional transfer into wheat by transgenesis and wide crossing, including the generation of a library of hexaploids incorporating diverse Ae. tauschii genomes. Exploiting the genomic diversity of the Ae. tauschii ancestral diploid genome permits rapid trait discovery and functional genetic validation in a hexaploid background amenable to breeding.
Clinical characteristics of choroidal microvasculature dropout in normal-tension glaucoma versus nonarteritic anterior ischemic optic neuropathy: an optical coherence tomography angiography study
Authors: Shin Joong Won , Lee Jin Yeong , Lee Byung Joo , Lim Hyun Taek , Kook Michael S.
Published: November 2021

The present study investigated the characteristics of choroidal microvasculature dropout (CMvD) in eyes with nonarteritic anterior ischemic optic neuropathy (NAION) versus those in eyes with normal-tension glaucoma (NTG). This study included 27 NAION, 27 NTG, and 27 healthy control subjects. CMvD was observed in 15 eyes (55.6%) of the NAION group and 20 (74.1%) of the NTG group. The area and angular width of CMvD were significantly greater in eyes with NAION (0.278 ± 0.172 mm2 and 86.5 ± 42.3°) than in those with NTG (0.138 ± 0.068 mm2 and 35.1 ± 16.2°, p = 0.002 and p < 0.001, respectively). CMvD in eyes with NAION were distributed in 120–250° and most frequently located at the temporal region, while CMvD in eyes with NTG showed double peaks at 220–280° and 110–140° and most frequently located at the inferotemporal region. The factors associated with the discrimination of NAION from NTG were greater area of CMvD (OR, 1.181; 95% CI, 1.021–1.366; p = 0.025) and location closer to the temporal region of the CMvD (OR, 0.904; 95% CI, 0.838–0.975; p = 0.009). The clinical characteristics of CMvD differed between eyes with NAION and those with NTG. Optical coherence tomography angiography may provide an additional approach to differentiating glaucoma from NAION.
Cross flow coupled with inertial focusing for separation of human sperm cells from semen and simulated TESE samples
Authors: Rahi Amid , Kazemi Mahsa , Pishbin Esmail , Karimi Sareh , Nazarian Hamid
Published: November 2021

A triplet spiral channel coupled with cross-flow filtration has been designed and fabricated in an effort to separate sperm cells from either semen or simulated testicular sperm extraction (TESE) samples.
Systems analysis of plasma IgG intact N-glycopeptides from patients with chronic kidney diseases via EThcD-sceHCD-MS/MS
Authors: Zhang Yong , Zheng Shanshan , Mao Yonghong , Cao Wei , Zhao Lijun , Wu Changwei , Cheng Jingqiu , Liu Fang , Li Guisen , Yang Hao
Published: November 2021

In this study, we established a sample preparation procedure for the separation and purification of IgG and a rapid detection procedure for the IgG subclasses with intact N-glycopeptides using EThcD-sceHCD-MS/MS for the first time.
One pot synthesis and self-assembly of methylene blue-backboned polymers
Authors: Cai Xuetong , Ji Luyang , Tang Hao , Wang Rong , Feng Fude
Published: November 2021

Methylene blue-backboned polymers prepared via fast oxidative polymerization are self-assembled to nanovesicles and nano rings as predicted using the DPD method.
Visible-light-induced photoacid catalysis: application in glycosylation with O-glycosyl trichloroacetimidates
Authors: Zhao Gaoyuan , Li Juncheng , Wang Ting
Published: November 2021

The development of visible-light-induced photoacid catalyzed glycosylation is reported.
Protein crystallisation with air bubble templates: case of gas–liquid–solid interfaces
Authors: Tian Wenqing , Rielly Chris , Yang Huaiyu
Published: November 2021

Crystal formation on air bubble–liquid interface, as soft template to efficiently prompt nucleation of proteins.
Structurally characterised new twisted conformer for cyclen, controlled by metal ion complexation as seen in NiII and CuII complexes with halides and pseudohalides
Authors: Verma Abhineet , Bhuvanesh Nattamai , Reibenspies Joseph , Tayade Sakharam B. , Kumbhar Avinash S. , Bretosh Kateryna , Sutter Jean-Pascal , Sunkari Sailaja S.
Published: November 2021

Conformational flexibility of cyclen controlled by complexation with Ni(ii) and Cu(ii) as evidenced by structural studies.
Effect of high purity molybdenum oxide(vi) on crystal growth and OLED technology
Authors: Khomyakov Andrew , Sukhanova Ekaterina , Mozhevitina Elena , Zykova Marina , Barkanov Artem , Avetisov Roman , Yurkin Alexander , Subbotin Kirill , Lis Olga , Avetissov Igor
Published: November 2021

The strong influence of MoO3chemical purity from 99.99 wt% to 99.999 wt% on lithium triborate (LBO) and NaLa(MoO4)2crystal growth as well as on OLED technologies has been demonstrated.
Correlation between the topologically close-packed structure and the deformation behavior of metallic Cu64.5Zr35.5
Authors: Zhou Li-Li , Tian Ze-An , Liang Yong-Chao , Mo Yun-Fei , Wang Cun-Jing , Li Fang-Zuo
Published: November 2021

The deformation response of the largest standard clusters depends both on the nearest characteristics and the linking pattern between them.
The thermoelectric properties of α-XP (X = Sb and Bi) monolayers from first-principles calculations
Authors: Liu Xin , Zhang Dingbo , Chen Yuanzheng , Wang Hui , Wang Hongyan , Ni Yuxiang
Published: November 2021

Thermoelectric (TE) materials as one of the effective solutions to the energy crisis are gaining more and more interest owing to their capability to generate electricity from waste heat without generating air pollution.
Molecular dissociation and proton transfer in aqueous methane solution under an electric field
Authors: Cassone Giuseppe , Sponer Jiri , Saija Franz
Published: November 2021

Here we present a study relying upon state-of-the-art ab initio molecular dynamics simulations where a liquid aqueous methane solution is exposed to strong oriented static and homogeneous electric fields.
Triel bonds within anion···anion complexes
Authors: Michalczyk Mariusz , Zierkiewicz Wiktor , Wysokiński Rafał , Scheiner Steve
Published: November 2021

Two TrX4−ions are stabilized by unusual σ-hole triel bonds with interaction energies surpassing even 30 kcal mol−1when immersed in water solvent.
Converting mesoporous polydopamine coated MIL-125 (Ti) to a core–shell heterostructure for efficient water desalination
Authors: Zhang Hao , Wang Chaohai , Li Xiaodie , Xie Jia , Yan Xin , Qi Junwen , Sun Xiuyun , Li Jiansheng
Published: November 2021

An ultrafine anatase TiO2/carbon nanocomposite confined into N-doped mesoporous carbon (TiO2/C@NMC) prepared from mesostructured polydopamine coated MIL-125 (Ti) shows outstanding hybrid capacitive deionization performance.
Self-propelled micro/nanomotors for removal of insoluble water contaminants: microplastics and oil spills
Authors: Wang Lei , Villa Katherine
Published: November 2021

This frontier review discusses the capabilities of self-propelled micro/nanomotors for the removal of oil and plastic-based pollutants in water, including future research directions for overcoming remaining challenges.
Iron(ii)-catalyzed intermolecular aziridination of alkenes employing hydroxylamine derivatives as clean nitrene sources
Authors: Kirby Georgina , Grimaud Laurence , Vitale Maxime R. , Prestat Guillaume , Berhal Farouk
Published: November 2021

The iron-catalyzed intermolecular aziridination of alkenes with hydroxylamine derivatives is described.
3D-QSAR, molecular docking and molecular dynamics simulations analyses of a series of heteroaryldihydropyrimidine derivatives as hepatitis B virus capsid assembly inhibitors
Authors: Chen Lu , Liu Wen-Guang , Xiong Fei , Ma Chao , Sun Chen , Zhu Yi-Ren , Zhang Xing-Guang , Wang Zhong-Hua
Published: November 2021

In silicodesign of heteroaryldihydropyrimidine-based selective HBV capsid assembly inhibitors.
Copper sulfide nanostructures: easy synthesis, photocatalytic and doxorubicin anticancer drug delivery applications
Authors: Rafiee Zahra , Davar Fatemeh , Hasani Saeed , Majedi Ali , Shalan Ahmed Esmail
Published: November 2021

Copper sulfide nanostructures with different morphologies were used as a photocatalyst and antitumor drug delivery.
Supramolecular electrocatalysis of a highly efficient oxygen evolution reaction with cucurbit[6]uril
Authors: Dai Xin , Jin Xian-Yi , Ge Qingmei , Zhao Jie , Liu Mao , Cong Hang , Tao Zhu , Jiang Nan
Published: November 2021

A supramolecular ternary electrocatalyst, fabricated via the stepwise-coating of polypyrrole, rGO and cucurbit[6]uril, was developed for highly efficient oxygen evolution reaction with full electrochemical performance.
Nickel-catalyzed reductive aminocarbonylation of vinyl triflates with nitro compounds for the synthesis of α,β-unsaturated amides
Authors: Huo Yong-Wang , Yao Lingyun , Qi Xinxin , Wu Xiao-Feng
Published: November 2021

A nickel-catalyzed reductive aminocarbonylation reaction for the synthesis of α,β-unsaturated amides has been described.
Imidazole-linked porphyrin-based conjugated microporous polymers for metal-free photocatalytic oxidative dehydrogenation of N-heterocycles
Authors: Chen Yaju , Jiang Jun
Published: November 2021

The prepared imidazole-linked porphyrin-based conjugated microporous polymers enable efficiently photocatalytic oxidative dehydrogenation of N-heterocycles under mild conditions, yielding unsaturated N-heteroarenes with high yield.
Calixarene-based porous 3D polymers and copolymers with high capacity and binding energy for CO2, CH4and Xe capture
Authors: Pedrini Alessandro , Perego Jacopo , Bracco Silvia , Bezuidenhout Charl X. , Sozzani Piero , Comotti Angiolina
Published: November 2021

Calixarene-based porous polymers and copolymers with surface area of 3000 m2g−1selectively capture CO2and CH4(DH of 35 and 24 kJ mol−1, respectively) in specific sites, as revealed by microcalorimetry, breakthrough experiments and HP129Xe NMR.
Hollow CoP spheres assembled from porous nanosheets as high-rate and ultra-stable electrodes for advanced supercapacitors
Authors: Sun Li , Xie Zhenbin , Wu Aiping , Tian Chungui , Wang Dongxu , Gu Ying , Gao Yachen , Fu Honggang
Published: November 2021

Hollow CoP spheres assembled by 2D porous nanosheets (HCPS) have been fabricated based on the phosphatizing of the Co-EG precursor and used as electrode for advanced supercapacitors with high rate capability and super-long cycle stability.
Cu–ion induced self-polymerization of Cu phthalocyanine to prepare low-cost organic cathode materials for Li-ion batteries with ultra-high voltage and ultra-fast rate capability
Authors: Zhang Haichang , Zhang Rui , Liu Xingjiang , Ding Fei , Shi Chunsheng , Zhou Zhen , Zhao Naiqin
Published: November 2021

We confirmed that CuPc monomers used as cathode materials are self-polymerized when charged to a high voltage of 4.4 V. The polymerized CuPc cathode exhibits excellent high rate capability and superior long-term cycling stability.
Modifying polymer PM6 by incorporating a third component for an enhanced short-circuit current density
Authors: Tu Silong , Zhang Li , Lin Xin , Xiao Liren , Wang Wen , Ling Qidan
Published: November 2021

We  developed novel D–A–D–D1-type polymers with unequal D and A units by incorporating a third component into the backbone of PM6 for enhanced short-circuit current density.
Ester-functionalized thermally activated delayed fluorescence materials
Authors: Tasaki Hiroshi , Shikita So , Park In Seob , Yasuda Takuma
Published: November 2021

A family of thermally activated delayed fluorescence (TADF) materials functionalized with carboxylate esters is developed.
Fetuin-A regulates adipose tissue macrophage content and activation in insulin resistant mice through MCP-1 and iNOS: involvement of IFNγ-JAK2-STAT1 pathway
Authors: Chattopadhyay Dipanjan , Das Snehasis , Guria Suktara , Basu Soumyadeep , Mukherjee Sutapa
Published: November 2021

In the context of obesity-induced adipose tissue (AT) inflammation, migration of macrophages and their polarization from predominantly anti-inflammatory to proinflammatory subtype is considered a pivotal event in the loss of adipose insulin sensitivity. Two major chemoattractants, monocyte chemoattractant protein-1 (MCP-1) and Fetuin-A (FetA), have been reported to stimulate macrophage migration into inflamed AT instigating inflammation. Moreover, FetA could notably modulate macrophage polarization, yet the mechanism(s) is unknown. The present study was undertaken to elucidate the mechanistic pathway involved in the actions of FetA and MCP-1 in obese AT. We found that FetA knockdown in high fat diet (HFD) fed mice could significantly subdue the augmented MCP-1 expression and reduce adipose tissue macrophage (ATM) content thereby indicating that MCP-1 is being regulated by FetA. Additionally, knockdown of FetA in HFD mice impeded the expression of inducible nitric oxide synthase (iNOS) reverting macrophage activation from mostly proinflammatory to anti-inflammatory state. It was observed that the stimulating effect of FetA on MCP-1 and iNOS was mediated through interferon γ (IFNγ) induced activation of JAK2-STAT1-NOX4 pathway. Furthermore, we detected that the enhanced IFNγ expression was accounted by the stimulatory effect of FetA upon the activities of both cJun and JNK. Taken together, our findings revealed that obesity-induced FetA acts as a master upstream regulator of AT inflammation by regulating MCP-1 and iNOS expression through JNK-cJun-IFNγ-JAK2-STAT1 signaling pathway. This study opened a new horizon in understanding the regulation of ATM content and activation in conditions of obesity-induced insulin resistance.
K2 discovery of a circumsecondary disk transiting EPIC 220208795
Authors: van der Kamp L. , van Dam D. M. , Kenworthy M. A. , Mamajek E. E. , Pojmański G.
Published: November 2021

Context. Observations of the star EPIC 220208795 (2MASS J01105556+0018507) reveal a single, deep and asymmetric eclipse, which we hypothesise is due to an eclipsing companion surrounded by a tilted and inclined opaque disk, similar to those seen around V928 Tau and EPIC 204376071.

Aims. We aim to derive physical parameters of the disk and orbital parameters for the companion around the primary star.

Methods. The modelling is carried out using a modified version of the python package pyPplusS, and optimisation is done using emcee. The period analysis makes use of photometry from ground-based surveys, where we performed a period folding search for other possible eclipses by the disk. Parameters obtained by the best model fits are used to obtain the parameter space of the orbital parameters, while the most likely period obtained is used to constrain these parameters.

Results. The best model has an opaque disk with a radius of 1.14 ± 0.03 R⊙, an impact parameter of 0.61 ± 0.02 R⊙, an inclination of 77.01° ± 0.03°, a tilt of 36.81° ± 0.05°, and a transverse velocity of 77.45 ± 0.05 km s−1. The two most likely periods are ~290 days and ~236 days, corresponding to an eccentricity of ~0.7, allowing us to make predictions for the epochs of the next eclipses. All models with tilted and inclined disks result in a minimum derived eccentricity of 0.3, which in combination with the two other known small transiting disk candidates V928 Tau and EPIC 204376071, suggest that there may be a common origin for their eccentric orbits.
Diagnosis and management of infected arthroplasty
Authors: Pannu Tejbir S. , Villa Jesus M. , Higuera Carlos A.
Published: November 2021

Periprosthetic joint infection (PJI) is one of the most dreadful complications after THA and TKA. Though prevention is of utmost importance in PJI management, the last decade has seen many remarkable developments in PJI diagnosis, including the introduction of several standardized PJI diagnostic definitions and biomarkers. Depending on the specific clinical situation, a myriad of treatment options for PJI are offered. Our review aims to summarize the pertinent information on PJI diagnosis and synthesize literature on the different treatment methods currently used in clinical practice. One of the most accepted PJI diagnostic definitions was developed by the Musculoskeletal Infection Society (MSIS) in 2011, later modified in the 2013 International Consensus Meeting (ICM). After promising results from studies, alpha-defensins and D-dimer were recently incorporated into the 2018 ICM PJI definition. The management choices for PJI include irrigation and debridement (DAIR), one-stage exchange arthroplasty, or two-stage exchange arthroplasty, to name a few. While two-stage revision has traditionally been the treatment of choice in the United States, there has been a growing body of evidence framing one-stage revision as a comparable choice. One-stage revision should be offered in patients meeting strict selection criteria: no sinus tract, proper soft tissue available for wound closure, appropriate bone stock, a favorable identifiable organism with encouraging antibiotic sensitivities (for cement and oral suppression later), and robust immunological status. DAIR can be considered in case of early infections with sensitive infecting organisms. Patients with multiple unsuccessful revisions or those who refuse further surgical intervention for PJI can be offered antibiotic suppression. If nothing seems to work, salvage procedures (resection arthroplasty and arthrodesis) are available as a last resort. Further research is encouraged to improve on diagnostic capabilities and develop evidence on the best treatment of choice for PJI.
The momentum of models
Authors: Heller Eric J.
Published: November 2021

There are opportunities for the application of chemical physics style thinking to models central to solid state physics. Solid state physics has largely been left to its own devices by the chemical physics theory community, which is a shame. I will show here that cross fertilization of ideas is real and beneficial to science. This essay is written with the hope of encouraging young theorists with a chemical physics background to enter this rich and promising area. There are many low hanging fruit available essentially because condensed matter physics traditions, models, and standards for progress are so much different than in chemical physics. By way of a warning label, right now neither community is supporting this endeavor. I am hoping this article will help, a little. I make the apology for using mainly (but not exclusively) my own narrow experience and contributions to illustrate this essay. I understand it is only a small piece of the pie, but I do believe the message here is larger: a chemical physics mindset is complementary to the condensed matter physics mindset, and they would work best together.
Uncertainty principles for the Fourier and the short-time Fourier transforms
Authors: Poria Anirudha
Published: November 2021

The aim of this paper is to establish a few uncertainty principles for the Fourier and the short-time Fourier transforms. In addition, we discuss an analog of the Donoho–Stark uncertainty principle and provide some estimates for the size of the essential support of the short-time Fourier transform.
Particle-in-cell simulations of low-pressure air plasma generated by pulsed x rays
Authors: Zhang Hantian , Zhou Qianhong , Zhou Haijing , Sun Qiang , Song Mengmeng , Dong Ye , Yang Wei , Yao Jiansheng
Published: November 2021

When a photon pulse illuminates a cavity, photoelectrons are emitted from the surface of the cavity, thereby producing the system-generated electromagnetic pulse (SGEMP). Previously, simulations on the SGEMP in a low-pressure environment using a swarm model showed poor applicability to describe the dynamics of photoelectrons and plasmas. In this work, a 3D electromagnetic particle-in-cell with the Monte Carlo collisions model was constructed to investigate the effect of low-pressure air (0–500 mTorr) on the cavity SGEMP response. To model air plasma created by high-energy (keV) photoelectron flows, six kinds of particles (electrons, N2, O2, N2+, O2+, and O2−), as well as the elastic, ionization, attachment, and excitation collisions, were included in the model. The results showed that the peak electric field was in the order of 106 V/m. The peak electric field decreased with increasing air pressure because of dissipation of the space charge barrier (SCB) owing to the generation of secondary electron-ions. The dissipation of the SCB allowed more axially moving photoelectrons, so the fraction of transmitted current and the peak magnetic field increased. The energy conversion between the charged particles and the electromagnetic fields is discussed. Approximately 9% of the photoelectron energy was converted to electromagnetic energy for the SGEMP in vacuum. When the gas pressure increased, the electromagnetic energy conversion rate decreased. The energy relaxation of secondary electrons played an important role in the evolution of the plasma density. To validate the established simulation model, the calculated current was compared with those in the benchmark experiments.
Contractivity properties of Ornstein–Uhlenbeck semigroup for mixed q-Araki–Woods von Neumann algebras
Authors: Bikram Panchugopal , Mohanta Rajeeb R.
Published: November 2021

We study certain non-tracial von Neumann algebras generated by some self-adjoint operators satisfying mixed q-commutation relations. Such algebras are discussed in the work of Bikram et al. [“Mixed q-deformed Araki-Woods von Neumann algebras,” (submitted)]. We prove the analog of Nelson’s hypercontractivity inequality for the mixed q-Ornstein–Uhlenbeck semigroup. We also show that the mixed q-Ornstein–Uhlenbeck semigroup is ultracontractive.
Controlling the rotation of drift tearing modes by biased electrode in ADITYA-U tokamak
Authors: Macwan Tanmay , Singh Kaushlender , Dolui Suman , Kumar Ankit , Raj Harshita , Gautam Pramila , Edappala Praveenlal , Ghosh J. , Tanna R. L. , Kumar Rohit , Jadeja K. A. , Patel K. M. , Aich Suman , Kumar Sameer , Raju D. , Chattopadhyay P. K. , Sen A. , Saxena Y. C. , Pal R.
Published: November 2021

The influence of background plasma poloidal rotation on the rotation frequency of the m/n = 2/1 drift tearing mode (DTM) has been studied in ADITYA-U tokamak. The poloidal rotation velocity of the background plasma in the ion diamagnetic direction is increased or decreased by inducing an outward or inward radial electric field, respectively, through a biased-electrode placed in the edge region of the plasma. The rotation frequency of the preexisting drift tearing mode, rotating in the electron diamagnetic direction, concomitantly decreased or increased with the application of bias depending on its polarity. The positive-bias increases the background plasma rotation in the ion-diamagnetic direction from its pre-bias value, hence decreasing the DTM rotation frequency, whereas the negative bias reduces the plasma rotation velocity in the ion-diamagnetic direction, hence increasing the mode rotation. In addition to that, a short gas puff introduced during the positive and negative bias pulse further reduces the mode frequency, however, with different amplitudes in different bias-polarities. These observations suggest that the background plasma rotation contributes significantly toward the rotation of DTMs, and the rotation frequency of the magnetohydrodynamic modes can be modified by varying the poloidal rotation of the background plasma and/or the diamagnetic drift frequency.
Bubble collapse and jet formation inside a liquid film
Authors: Mahravan Ehsan , Kim Daegyoum
Published: November 2021

The cavitation of a hemispherical bubble nucleated inside a liquid film of microscale thickness and the subsequent formation of liquid jets are investigated numerically, using the compressible volume of fluid method, in particular, in the context of laser-induced forward transfer (LIFT). Because of the presence of both a solid wall and a free surface, the dynamics of the bubble differ notably from those near a solid wall alone or a free surface alone. When the liquid film is sufficiently thin, the shape of the expanded bubble becomes narrow along the axial direction, forging a stretched cone with a spike. The interface of the bubble near the spike opposite to the solid wall contracts much earlier than the other parts, leading to the separation of the spike. As a result of this separation, the collapse of the bubble is stronger, and the outward jet and inward jet along the axial direction are sharper and faster. However, as the film thickness increases, the tip separation of the bubble becomes weaker, and both outward and inward liquid jets become thicker and slower. In addition, an increase in liquid viscosity changes the bubble shape from an axially stretched cone shape to a round shape because of enhanced viscous force along the radial direction inside the thin film, which eventually results in disappearance of the inward jet. The fundamental insights elucidated in this work can serve as a quantitative design guideline for the LIFT.
Physical investigation of transient dynamic behaviors of cavitation-induced vibration over a flexible hydrofoil
Authors: Sun Tiezhi , Dong Songwen , Liu Yuanqing , Huang Huakun , Zhang Guiyong
Published: November 2021

The unsteady flow characteristics of cavitation often cause adverse effects such as vibration, noise, and erosion. With the application of new materials, the vibration and deformation of hydrofoils are increasingly obvious, and the fluid–structure interaction becomes very important. In this paper, the cavitating flow fields of a NACA 66 rigid hydrofoil and flexible hydrofoil are numerically studied. The hydroelasticity of the flexible hydrofoil is implemented by using a fluid–structure interaction method under a tight-coupling strategy. The Schnerr–Sauer model is used to describe the cavitation process, and the turbulence is resolved by the large eddy simulation method. The finite element method is used to calculate the structural deformation. Compared with the rigid hydrofoil, the flexible hydrofoil exhibits smaller and more diffuse areas of cavitation. This is because the hydrofoil hydroelasticity inhibits the development of cavitation and causes larger amplitude and more intense pressure pulsations. In addition, the hydroelasticity increases the vorticity and the flow field becomes more complex. Analysis of the turbulence characteristics of the wake flow field show that the flexible hydrofoil creates more intense turbulence and a wider velocity pulsation area in the direction of incoming flow. Finally, using dynamic mode decomposition to capture the flow field modal characteristics, we find that the energy of the flexible hydrofoil is mainly concentrated in the first two modes, producing a larger coherent structure, while the high-frequency modes contain less energy.
Manipulation of laser-accelerated proton beam spatial distribution by laser machined microstructure targets
Authors: Li D. Y. , Yang T. , Wu M. J. , Cheng H. , Li Y. Z. , Xia Y. D. , Yan Y. , Geng Y. X. , Zhao Y. Y. , Lin C. , Yan X. Q.
Published: November 2021

Experimental study of laser proton acceleration was carried out using laser machined line targets and cross targets with tens of micrometers scale. We have found that both the shape and material of the microstructure targets have significant influences on the distribution of the proton beam. For the aluminum line target, the proton beam spot expands in a direction perpendicular to the boundary of the target; while for the plastic line target, it expands parallel to the boundary of the target. Detailed PIC simulations of the aluminum target have been carried out, which show that due to the lateral transport of hot electrons and the sheath fields accumulated at the edge of the microstructure target, the divergence angle of the accelerated proton beam is changed accordingly, thereby modulating the spatial distribution: the elliptical beam spot can be obtained from the line target, and the quasi-square beam spot can be obtained from the cross target. Simulations of the plastic target indicate that the difference in the electron transport properties for the two types of targets may be the reason for the completely different beam spot shapes. This work shows that the microstructure targets can be a potential method to manipulate the spatial distribution and uniformity of the proton beam.
Quasiballistic electron transport in cryogenic SiGe HBTs studied using an exact, semi-analytic solution to the Boltzmann equation
Authors: Naik Nachiket R. , Minnich Austin J.
Published: November 2021

Silicon–germanium heterojunction bipolar transistors (HBTs) are of interest as low-noise microwave amplifiers due to their competitive noise performance and low cost relative to III–V devices. The fundamental noise performance limits of HBTs are thus of interest, and several studies report that quasiballistic electron transport across the base is a mechanism leading to cryogenic non-ideal IV characteristics that affect these limits. However, this conclusion has not been rigorously tested against theoretical predictions because prior studies modeled electron transport with empirical approaches or approximate solutions of the Boltzmann equation. Here, we study non-diffusive transport in narrow-base SiGe HBTs using an exact, semi-analytic solution of the Boltzmann equation based on an asymptotic expansion approach. We find that the computed transport characteristics are inconsistent with experiments, implying that quasiballistic electron transport is unlikely to be the origin of cryogenic non-ideal IV characteristics. Our work helps to identify the mechanisms governing the lower limits of the microwave noise figure of cryogenic HBT amplifiers.
Role of transferred graphene on atomic interaction of GaAs for remote epitaxy
Authors: Kim Hyunseok , Kim Jong Chan , Jeong Yoongu , Yu Jimyeong , Lu Kuangye , Lee Doyoon , Kim Naeun , Jeong Hu Young , Kim Jeehwan , Kim Sungkyu
Published: November 2021

Remote epitaxy is a recently discovered type of epitaxy, wherein single-crystalline thin films can be grown on graphene-coated substrates following the crystallinity of the substrate via remote interaction through graphene. Although remote epitaxy provides a pathway to form freestanding membranes by controlled exfoliation of grown film at the graphene interface, implementing remote epitaxy is not straightforward because atomically precise control of interface is required. Here, we unveil the role of the graphene–substrate interface on the remote epitaxy of GaAs by investigating the interface at the atomic scale. By comparing remote epitaxy on wet-transferred and dry-transferred graphene, we show that interfacial oxide layer formed at the graphene–substrate interface hinders remote interaction through graphene when wet-transferred graphene is employed, which is confirmed by an increase of interatomic distance through graphene and also by the formation of polycrystalline films on graphene. On the other hand, when dry-transferred graphene is employed, the interface is free of native oxide, and single-crystalline remote epitaxial films are formed on graphene, with the interatomic distance between the epilayer and the substrate matching with the theoretically predicted value. The first atomic layer of the grown film on graphene is vertically aligned with the top layer of the substrate with these atoms having different polarities, substantiating the remote interaction of adatoms with the substrate through graphene. These results directly show the impact of interface properties formed by different graphene transfer methods on remote epitaxy.
Discharge and plasma plume characterization of a 100 A-class LaB6 hollow cathode
Authors: Mazouffre S. , Joussot R. , Vincent B. , Tsikata S.
Published: November 2021

This article reports on the characterization of a laboratory model 100 A-class hollow cathode with a sintered lanthanum hexaboride (LaB6) emitter for high-power Hall thrusters. The cathode has been fired up to 70 A with xenon as working gas. The cathode architecture, test setup, ignition procedure, and power consumption are described first. The second part of this contribution comments on the current–voltage characteristics and the discharge modes obtained for discharge currents in the 30–70 A range and flow rates in the 15–30 SCCM range. The cathode operates in a spot mode at high discharge currents and in a plume mode with large oscillations at low currents and low gas flow rate. Spectral analysis shows that most frequencies reside in the 10–200 kHz range with flat and sharp distributions in plume and spot modes, respectively. Finally, we present electron temperatures and densities measured in the cathode plasma plume by means of incoherent Thomson scattering. The two quantities decrease along the axis. The density is large (up to ∼1019m−3) and increases with both the ion current and the gas flow rate. The electron temperature increases with the current and decreases with the gas flow rate. The temperature remains relatively low (<1.5 eV) in spite of large currents and applied powers.
Infrared imaging of samples in ultrahigh pressure diamond anvil cells
Authors: Patel Tarun , Drozdov A. , Minkov V. S. , Eremets M. I. , Nicol E. J. , Carbotte J. P. , Timusk T. , Tsen A. W.
Published: November 2021

We describe an experimental platform that generates infrared images of micrometer-sized samples in the high pressure region of a diamond anvil cell. Using a 2.3 μm laser as a source of radiation, the system will be particularly useful in identifying hydride superconductors, which exhibit an anomalous temperature dependence of reflectivity in the 2.3 μm region. Our system shows an intensity stability within 1% when the sample temperature is swept from 100 to 300 K. The spatial stability is of the order of a few micrometers in the same temperature range.
Effects of polymer grain boundary passivation on organic–inorganic hybrid perovskite field-effect transistors
Authors: Zhou Yuchen , Tiwale Nikhil , Yin Yifan , Subramanian Ashwanth , Rafailovich Miriam H. , Nam Chang-Yong
Published: November 2021

Despite successful applications of solution-processed organic–inorganic hybrid perovskites (OIHPs) such as archetypical methylammonium lead iodide (MAPI) in high-performance optoelectronic devices including solar cells and light emitting diodes, their application in field-effect transistors (FETs) remains relatively limited due to the unresolved issues caused by ion migration in OIHPs, such as screening of gate electric fields, lowered device on-off ratios and field-effect mobility, and large hysteresis in the FET transfer characteristics. Here, we report improved performances of the MAPI-based FET via a polymer-additive-based grain boundary (GB) passivation approach that suppresses the ion migration. Polycaprolactone (PCL) was incorporated into the MAPI FET as a GB-passivation additive as confirmed by scanning electron and atomic force microscopies. Unlike the typical n-type behavior and large transfer hysteresis in the starting, pristine MAPI FETs, the GB passivation by PCL led to a drastically reduced hysteresis in FET transfer characteristics, while hinting at an ambipolar transport and slight improvement in mobility, indicating a reduced ion migration in the PCL-incorporated MAPI FET. The effect of PCL GB passivation in suppressing ion migration was directly confirmed by the measured, increased activation energy for ion migration in the PCL-incorporated MAPI. The results not only represent the first report of the polymer-additive-based mitigation of the ion migration in the MAPI FET but also suggest potential utilities of the approach for enabling high-performance OIHP FETs and electronic devices in general.
Effectiveness of millisecond pulse discharge on hypersonic oblique shock wave
Authors: Wang Hongyu , Xie Feng , Li Jie , Yao Cheng , Yang Yanguang
Published: November 2021

The characteristics of millisecond pulse discharge in quiescent air and its effects on a Mach 6 hypersonic oblique shock over a ramp have been experimentally investigated with high-speed schlieren imaging and surface pressure measurement. The discharge between three pairs of electrodes was aligned in the direction of the airflow with pulse widths extending to a few milliseconds. The evolutionary characteristics of the energy deposition induced by the discharge pulses in quiescent air reveals that the discharge generating a significant thermal disturbance and lasting long enough may have greater control authority on hypersonic shock manipulation. In hypersonic flow, the plasma layer generated by the discharge propagates downstream and accumulates at a high penetration depth. Dilution of the ramp-induced ramp shock wave is observed under the disturbance of the plasma layer at a frequency of 100 Hz. Under repetitive pulse discharge, shock wave attenuation was demonstrated by pressure decreasing along the compression surface at the region where the plasma layer covers. The law of transient pressure distribution is acquired with the aid of the p–θ polar curve in shock wave analysis. The modification of pressure distribution indicates that the aerodynamic force of a compression surface can be controlled by deploying the control strategy.
Bilayer-passivated stable dif-TES-ADT organic thin-film transistors
Authors: Chen Yanyan , Wang Mingxiang , Zhang Dongli , Wang Huaisheng , Deng Wei , Shi Jialin , Jie Jiansheng
Published: November 2021

The active region of organic thin film transistors (OTFTs) is usually sensitive to moisture and O2 in the air ambient, which hinders their practical applications. In this study, the effects of air ambient on characteristics of unpassivated 2,8-difluoro-5,11-bis (triethylsilylethynyl) anthradithiophene (dif-TES-ADT) OTFTs are clarified. The device is much more sensitive to H2O vapor than O2, although both of which cause TFT instability. To improve the environmental stability, inkjet-printed passivation of the fluoropolymer CYTOP and UV curing adhesive are compared. It is found that the CYTOP passivation is well compatible with the organic channel while the UV curing adhesive has excellent barrier ability to both H2O vapor and O2. Then CYTOP/UV adhesive bilayer passivation combining advantages of both materials is introduced to achieve stable operation of OTFTs, which can resist saturated H2O vapor and O2 for 25 days.
On the coupling mechanism of rain–wind two-phase flow induced cable vibration: A wake-dynamics perspective
Authors: Gao Donglai , Zhang Shuai , Ning Zhichao , Chen Wen-Li , Li Hui
Published: November 2021

Large amplitude rain–wind induced vibration (RWIV) of stay cables of long-span cable-stayed bridges has been a major concern in the past three decades, yet its excitation mechanism has not been clarified thoroughly. Recent numerical simulations and experimental work showed that when the RWIV of a cable is developing, the dominant frequency of its unsteady lift forces is notably decreased, i.e., the conventional Strouhal law of cylinder flow is obeyed. In some experimental studies, however, the small-scale vortical structures, which are believed to be closely associated with the low-frequency fluctuating components, are visualized qualitatively in the cable wake during the RWIV. In the present work, the first experimental observation of the dynamic wake behind a cable during the RWIV is presented. The RWIV is reappeared based on a stay cable model supported by springs in wind tunnel tests. The dynamic characteristics of the water rivulet on the upper surface of the cable are recorded by a high-speed camera, and the detailed wake flow of the cable is captured by employing the high-speed particle image velocimetry technique. We focus on the low-frequency synchronization between the cable vibration, upper-rivulet movement, and the wake dynamics to investigate the excitation mechanism of the RWIV. A three-phase (gas–liquid–solid) coupling scenario is finally proposed to explain this interesting phenomenon as low-frequency resonance between fluids and the cable structure.
Time resolved plasma diagnostics for pulsed 2.45 GHz hydrogen discharges
Authors: Megía-Macías A. , Barrios-Díaz E. , Cortázar O. D.
Published: November 2021

A review of the last ten years of advances in temporal resolved plasma diagnostics for pulsed operated 2.45 GHz microwave-driven hydrogen discharges is presented. Special attention has been paid to the study of breakdown and decay processes where some particular phenomena are explored for application in ion sources. Measurements of plasma temperature and density using vacuum ultraviolet spectroscopy, ultra-fast photography, and ion mass spectroscopy are performed in detail, including examples and results.
Moissanite anvil cell single crystal NMR at pressures of up to 4.4 GPa
Authors: Kattinger Carsten , Guehne Robin , Tsankov Stefan , Jurkutat Michael , Erb Andreas , Haase Juergen
Published: November 2021

High-pressure anvil cell nuclear magnetic resonance (NMR) studies of single crystals are challenging, but they can offer much insight into material properties. A microcoil inside the high-pressure region that encloses the crystal offers a good signal-to-noise ratio, but special care has to be taken to warrant hydrostatic conditions or to avoid rupture of the crystal or coil. By introducing precise monitoring of the height and diameter of the pressurized sample chamber, this can be ensured, and the data reveal the behavior of the sample chamber under pressure. While its total volume is given by the compression of the enclosed pressure transmitting fluid, the aspect ratio of the cylindrical chamber changes considerably. 63Cu and 17O NMR of two differently doped single crystals of YBa2Cu3O7−δ at pressures of up to about 4.4 GPa show the function of the cell, and orientation dependent spectra prove the soundness of the arrangement.