bluuebunny/crossref_metadata_2025 huggingface dataset:
Highly Selective Metal‐Free Electrochemical Production of Hydrogen Peroxide on Functionalized Vertical Graphene Edges
Authors: Zhang Ding , Tsounis Constantine , Ma Zhipeng , Djaidiguna Dominique , Bedford Nicholas M. , Thomsen Lars , Lu Xunyu , Chu Dewei , Amal Rose , Han Zhaojun
Published: November 2021

Electrochemical generation of hydrogen peroxide (H2O2) is an attractive alternative to the energy‐intensive anthraquinone oxidation process. Metal‐free carbon‐based materials such as graphene show great promise as efficient electrocatalysts in alkaline media. In particular, the graphene edges possess superior electrochemical properties than the basal plane. However, identification and enhancement of the catalytically active sites at the edges remain challenging. Furthermore, control of surface wettability to enhance gas diffusion and promote the performance in bulk electrolysis is largely unexplored. Here, a metal‐free edge‐rich vertical graphene catalyst is synthesized and exhibits a superior performance for H2O2 production, with a high onset potential (0.8 V versus reversible hydrogen electrode (RHE) at 0.1 mA cm−2) and 100% Faradaic efficiency at various potentials. By tailoring the oxygen‐containing functional groups using various techniques of electrochemical oxidation, thermal annealing and oxygen plasma post‐treatment, the edge‐bound in‐plane ether‐type (COC) groups are revealed to account for the superior catalytic performance. To manipulate the surface wettability, a simple vacuum‐based method is developed to effectively induce material hydrophobicity by accelerating hydrocarbon adsorption. The increased hydrophobicity greatly enhances gas transfer without compromising the Faradaic efficiency, enabling a H2O2 productivity of 1767 mmol gcatalyst−1 h−1 at 0.4 V versus RHE.
Rational Design of Li‐Wicking Hosts for Ultrafast Fabrication of Flexible and Stable Lithium Metal Anodes
Authors: Chang Jian , Hu Hong , Shang Jian , Fang Ruopian , Shou Dahua , Xie Chuan , Gao Yuan , Yang Yu , Zhuang Qiu Na , Lu Xi , Zhang Yao Kang , Li Feng , Zheng Zijian
Published: November 2021

The ever‐increasing development of flexible and wearable electronics has imposed unprecedented demand on flexible batteries of high energy density and excellent mechanical stability. Rechargeable lithium (Li) metal battery shows great advantages in terms of its high theoretical energy density. However, the use of Li metal anode for flexible batteries faces huge challenges in terms of its undesirable dendrite growth, poor mechanical flexibility, and slow fabrication speed. Here, a highly scalable Li‐wicking strategy is reported that allows ultrafast fabrication of mechanically flexible and electrochemically stable Li metal anodes. Through the rational design of the interface and structure of the wicking host, the mean speed of Li‐wicking reaches 10 m2 min−1, which is 1000 to 100 000 fold faster than the reported electrochemical deposition or thermal infusion methods and meets the industrial fabrication speed. Importantly, the Li‐wicking process results in a unique 3D Li metal structure, which not only offers remarkable flexibility but also suppresses the dendrite formation. Paring the Li metal anode with lithium‐iron phosphate or sulfur cathode yields flexible full cells that possess a high charging rate (8.0 mA cm−2), high energy density (300–380 Wh kg−1), long cycling stability (over 550 cycles), and excellent mechanical robustness (500 bending cycles).
CMOS‐Compatible Electronic–Plasmonic Transducers Based on Plasmonic Tunnel Junctions and Schottky Diodes
Authors: Wang Fangwei , Liu Yan , Hoang Thanh Xuan , Chu Hong‐Son , Chua Soo‐Jin , Nijhuis Christian A.
Published: November 2021

To develop methods to generate, manipulate, and detect plasmonic signals by electrical means with complementary metal–oxide–semiconductor (CMOS)‐compatible materials is essential to realize on‐chip electronic–plasmonic transduction. Here, electrically driven, CMOS‐compatible electronic–plasmonic transducers with Al–AlOX–Cu tunnel junctions as the excitation source of surface plasmon polaritons (SPPs) and Si–Cu Schottky diodes as the detector of SPPs, connected via plasmonic strip waveguides of Cu, are demonstrated. Remarkably, the electronic–plasmonic transducers exhibit overall transduction efficiency of 1.85 ± 0.03%, five times higher than previously reported transducers with two tunnel junctions (metal–insulator–metal (MIM)–MIM transducers) where SPPs are detected based on optical rectification. The result establishes a new platform to convert electronic signals to plasmonic signals via electrical means, paving the way toward CMOS‐compatible plasmonic components.
Design and Realization of Ohmic and Schottky Interfaces for Oxide Electronics
Authors: Zhang Jie , Pai Yun-Yi , Lapano Jason , Mazza Alessandro R. , Lee Ho Nyung , Moore Rob G. , Lawrie Benjamin J. , Ward T. Zac , Eres Gyula , Cooper Valentino R. , Brahlek Matthew
Published: November 2021

Understanding band alignment and charge transfer at complex oxide interfaces is critical to tailoring and utilizing their diverse functionality. Toward this goal, both Ohmic‐ and Schottky‐like charge transfers at oxide/oxide semiconductor/metal interfaces are designed and experimentally validated. A method for predicting band alignment and charge transfer in ABO3 perovskites is utilized, where previously established rules for simple semiconductors fail. The prototypical systems chosen are the rare class of oxide metals, SrBO3 with B = V–Ta, when interfaced with the multifaceted semiconducting oxide, SrTiO3. For B = Nb and Ta, it is confirmed that a large accumulation of charge occurs in SrTiO3 due to the higher energy Nb and Ta states relative to Ti. This gives rise to a high mobility metallic interface, which is an ideal epitaxial oxide/oxide Ohmic contact. On the contrary, for B = V, there is no charge transfer into the SrTiO3 interface, which serves as a highly conductive epitaxial gate metal. Going beyond these specific cases, this work opens the door to integrating the vast phenomena of ABO3 perovskites into a wide range of practical devices.
Manipulating the Crystalline Morphology in the Nonfullerene Acceptor Mixture to Improve the Carrier Transport and Suppress the Energetic Disorder
Authors: Zhang Ming , Zhu Lei , Qiu Chaoqun , Hao Tianyu , Jiang Yufeng , Leng Shifeng , Chen Jiajun , Zhou Guanqing , Zhou Zichun , Zou Yecheng , Su Xuan , Shi Zhiwen , Zhu Haiming , Zhang Yongming , Russell Thomas P , Zhu Xiaozhang , Liu Feng
Published: November 2021

Mixtures of nonfullerene acceptors (NFAs) are prepared to fine‐tune bulk heterojunction (BHJ) thin‐film morphologies. The acceptor phase resulting from these mixtures has unique physical properties with excellent optoelectronic processes that dictate the output of organic photovoltaic (OPV) devices. Remarkable short‐circuit current densities (JSC) and fill factors (FFs) are achieved due to the formation of better crystalline fibrils that suppress geminate recombination, leading to improved charge transport with enhanced crystallinity and aligned cascading energy levels confirm efficient exciton diffusion and dissociation, yielding more effective exciton recycling. The decreased Urbach energy and suppressed energetic disorder account for the improvement in the open‐circuit voltage (VOC). A maximum power conversion efficiency of 17.86% is obtained, underscoring the importance of using specific material interactions to produce a suitable morphology and manage energy loss, resulting in ideal organic solar cell (OSC) devices.
Identifying Water Oxidation Mechanisms at Pure and Titanium‐Doped Hematite‐Based Photoanodes with Spectroelectrochemistry
Authors: Zhang Jifang , Lin Qiyuan , Wang Zhenlei , Liu Haowen , Li Xuanzhang , Zhang Yuegang
Published: November 2021

Investigation of the mechanism of the water oxidation reaction for hematite photoanodes has been one of the most persistently pursued topics in the course of understanding photoelectrochemical water splitting by transition metal oxides. Unfortunately, existing experimental techniques often require over‐simplified models and theories that assume only one reaction path. In this work, however, it is proposed that water oxidation on hematite can proceed via mixed reaction paths according to spectroelectrochemical results without a priori assumptions. The true absorption signals of surface states responsible for water oxidation are isolated from subsidiary signals for undoped and Ti‐doped hematite and contrasted with those of inactive species. The evolution of absorption signals as a function of applied potential and illumination intensity highlights the non‐negligible contribution of direct hole transfer, especially for highly doped hematite.
Electrically and Optically Controllable p–n Junction Memtransistor Based on an Al2O3 Encapsulated 2D Te/ReS2 van der Waals Heterostructure
Authors: Nguyen Duc Anh , Jo Yongcheol , Tran Thi Uyen , Jeong Mun Seok , Kim Hyungsang , Im Hyunsik
Published: November 2021

The exploration of memtransistors as a combination of a memristor and a transistor has recently attracted intensive attention because it offers a promising candidate for next‐generation multilevel nonvolatile memories and synaptic devices. However, the present state‐of‐the‐art memtransistors, which are based on a single material, such as MoS2 or perovskite, exhibit a relatively low switching ratio, require extremely high electric fields to modulate bistable resistance states and do not perform multifunctional operations. Here, the realization of an electrically and optically controllable p–n junction memtransistor using an Al2O3 encapsulated 2D Te/ReS2 van der Waals heterostructure is reported. The hybrid memtransistor shows a reversible bipolar resistance switching behavior between a low resistance state and a high resistance state with a high switching ratio up to 106 at a low operating voltage (<10 V), high cycling endurance, and long retention time. Moreover, multiple resistance states are achieved by applying different bias voltages, gate voltages, or light powers. In addition, logical operations, including the inverter and AND/OR gates, and synaptic activities are performed by controlling the optical and electrical inputs. The work offers a novel strategy for the reliable fabrication of p–n junction memtransistors for multifunctional devices and neuromorphic applications.
In Situ Constructing Intermediate Energy‐Level Perovskite Transition Layer for 15.03% Efficiency HTL‐Free Carbon‐Based Perovskite Solar Cells with a High Fill Factor of 0.81
Authors: Wang Kexiang , Yin Ran , Sun Weiwei , Huo Xiaonan , Liu Jingwen , Gao Yukun , You Tingting , Yin Penggang
Published: November 2021

Hole transporting layer (HTL)‐free, all‐inorganic CsPbX3 (X: I, Br, or mixed halides), carbon‐based perovskite solar cells (C‐PSCs) show promising prospect for photovoltaic application due to their low cost, excellent stability, and theoretical high efficiency. However, the inefficient hole extraction of the carbon electrode and relatively narrow light absorption range of inorganic perovskite limit the power conversion efficiency (PCE) of this kind of PSCs. Herein, these issues are addressed through in situ constructing of an intermediate energy‐level perovskite transition layer between CsPbI2.2Br0.8 and the carbon electrode via a facile formamidinium iodide (FAI) posttreatment strategy. It is demonstrated that the (CsFA)PbI3–xBrx film is in situ formed atop inorganic perovskite due to the ions exchange between FAI and CsPbI2.2Br0.8, which can not only broaden the light absorption edge of CsPbI2.2Br0.8 from 657 to 680 nm, but also serve as a hole transfer highway between CsPbI2.2Br0.8 and the carbon electrode, mainly due to its suitable intermediate energy‐level and effective defect passivation. Consequently, the optimized HTL‐free C‐PSC achieves a champion PCE of 15.03% with an ultrahigh fill factor of 0.81. Besides, the stability of CsPbI2.2Br0.8 film (especially under humid environment) and corresponding C‐PSC are also improved.
Engineering a Versatile Spectrally Selective Absorber for Moderate‐ and Low‐Temperature Application with Gradient High‐Entropy Nitride Nanofilms
Authors: He Cheng-Yu , Zhao Peng , Qiu Xiao-Li , Liu Bao-Hua , Liu Gang , Gao Xiang-Hu
Published: November 2021

Spectrally selective absorber with superior thermal stability and optical properties is crucial for photothermal conversion applications, including evaporation, anti‐icing, medical sterilization, photothermal catalysis, and solar‐thermal power. Efforts are being made to develop entropy‐stabilized high‐entropy ceramics as high‐performance functional materials, which promise a wide range of potential applications in the fields of energy storage and conversion owing to their diverse compositions and outstanding physical and chemical properties. Herein, an entropy‐stabilized strategy is used to boost the performance of spectrally selective absorbers by carefully choosing a high‐entropy alloy (TiVCrAlZr) target with a reasonable element design, which exhibits a good solar absorptance (α = 96.1%) and low thermal emittance (ϵ = 7.8%). Long‐term thermal stability investigation demonstrates that the entropy‐stabilized absorber could endure at 400 °C for 168 h. Under the irradiation of simulated sunlight, the surface temperature of the absorber can reach up to 105 °C, which is essential for middle‐ and low‐temperature applications. Overall, this work provides significant insights into the spectral selectivity of high‐entropy alloy nitrides and offers a new strategy for designing and developing moderate and low solar selective absorbing coatings via a high‐entropy strategy.
High‐Efficiency and Stable Perovskite Solar Cells Enabled by Low‐Dimensional Perovskite Surface Modifiers
Authors: Cheng Qian , Xia Haoran , Li Xing , Wang Boxin , Li Yanxun , Zhang Xuning , Zhang Hong , Zhang Yuan , Zhou Huiqiong
Published: November 2021

While interface modification based on organic spacer cations has been proven to be a viable strategy to boost the performance of 3D perovskite solar cells, the mechanisms behind the accomplished efficiency enhancement and the selection rule for organic spacers are yet to be clarified. Herein, based on representative four ammonium halide salts featuring different chain lengths as spacer cations for the 2D perovskite surface modifier, it is shown that choosing appropriately sized spacers can lead to synergetic mediation on interfacial passivation of point and structural defects and the crystallization of 2D perovskite components in protecting the buried 3D perovskite film. As a result, promoted charge transport and extraction with suppressed charge trapping and recombination are simultaneously realized in the 3D/2D perovskite solar cells. With the optimal spacer cation phenylpropylammonium iodide (PPAI), the resultant 3D/2D devices produce a power conversion efficiency of 22.57% with a fill factor exceeding 0.8. Favorably, the PPAI‐treated devices exhibit considerable gains in stability under various external stresses.
Ternary Strategy Enabling High‐Performance Organic Solar Cells with Optimized Film Morphology and Reduced Nonradiative Energy Loss
Authors: Li Miao , Zhou Yuanyuan , Zhang Ming , Liu Yahui , Ma Zaifei , Liu Feng , Qin Ruiping , Bo Zhishan
Published: November 2021

Ternary strategy has been demonstrated to be an effective way to improve power conversion efficiency (PCE) of single‐junction organic solar cells (OSCs). Herein, high‐efficiency ternary OSCs are fabricated based on the PBDB‐T:DO‐2F binary system and acceptor IDTT‐OB with asymmetric side chains as the third component. The introduction of nonfullerene acceptors (NFAs) IDTT‐OB as a third component can efficiently increase the compatibility of the ternary system, reduce the crystallinity of DO‐2F, optimize the blend film morphology, improve the charge transport and collection, suppress the bimolecular recombination, and reduce the nonradiative energy loss (ΔEnonrad). Finally, the PBDB‐T:DO‐2F:IDTT‐OB‐based ternary device exhibits a high PCE of 14.09% with Voc of 0.87 V, Jsc of 21.47 mA cm−2, and fill factor of 75.70%, which is about 30% higher than the corresponding PBDB‐T:DO‐2F‐ and PBDB‐T:IDTT‐OB‐based binary devices. Meanwhile, the ternary device also achieves a very low ΔEnonrad of 0.22 eV. This work indicates that the ternary strategy can effectively optimize morphology of active layer, reduce nonradiative energy loss, and further improve photovoltaic performance of OSCs.
Surface Defect Classification of Steel Strip with Few Samples Based on Dual‐Stream Neural Network
Authors: Zhang Jiaqiao , Li Shihao , Yan Yan , Ni Zhonghua , Ni Hongjun
Published: November 2021

The automatic classification of surface defects is significant to the steel strip inspection system. However, influenced by the lack of samples, it is difficult to improve the classification accuracy. Herein, a novel dual‐stream neural network is proposed, which is composed by two streams of sample generation and classification training. Subsequently, numerous defect samples are generated for the classifier pretraining, and the real steel strip surface defects are classified by the transfer learning method. The experiment results demonstrate that the dual‐stream neural network has the highest classification accuracy of 99.70% among the state‐of‐the‐art classifiers, and the classification accuracy increasesd by 9.67% through generating plentiful similar images for pretraining. Moreover, the convolutional neural network (CNN) can improve the quality of generated defect images. When the number of epochs reaches 2000, the generated images are closest to the real labeled images. Finally, the cross‐validation proves that the dual‐stream neural network has excellent stability and robustness, without over‐fitting problem in the training process.
A call for the examination of multiracial students in Minority Serving Institutions
Authors: Olivo Victoria Barbosa , Cepeda Rebecca
Published: November 2021

This article describes the limited research on multiracial students at Minority Serving Institutions (MSIs). We call on scholars studying MSIs to question their conceptualizations of race and the ways they promote the assumption of monoracial identities.
Navigating involvement spaces: The impact of campus environment on multiracial identity development
Authors: Stites Alicia K. , Khan Mohammad‐Mehdi A. , Dean‐Scott Shannon R.
Published: November 2021

This article presents the experiences of Multiracial students at a Hispanic Serving Institution (HSI) and the unique challenges they face in exploring their racial identities and finding belonging.
Being multiracial in a virtual society: Seeking community and exploring identity
Authors: Luna Rachel H.
Published: November 2021

This article presents an overview of current Internet and social media trends, followed by a description of online experiences for minoritized and Multiracial students. Implications for student affairs scholarship and practice are offered.
Resolving tensions for Black–White multiracial students in master's level student affairs graduate programs
Authors: Risku Kamrie J. , Arnold Brandon T.
Published: November 2021

This article examines monoracism in master's level student affairs graduate programs and offers implications for resolving tension Multiracial students may feel based on the narratives of two Black–White Multiracial graduate students.
Emerging Characterization Techniques for Electrode Interfaces in Sulfide‐Based All‐Solid‐State Lithium Batteries
Authors: Zhao Feipeng , Zhang Shumin , Li Yanguang , Sun Xueliang
Published: November 2021

All‐solid‐state Li batteries (ASSLBs) are attracting increasing attentions due to their improved safety and high energy density compared with conventional liquid electrolyte‐based Li‐ion batteries (LIBs). ASSLBs based on sulfide solid‐state electrolytes (SEs) is one of the most popular categories, because sulfide SEs have a very competitive ionic conductivity (up to over 10−2 S cm−1 at room temperature), medium mechanical stiffness, decent contact with electrode materials, and negligible grain boundary resistance. However, interface problems between electrode materials and sulfide SEs seriously plague the development of high‐performance sulfide‐based ASSLBs. In‐depth understandings on the electrode interface problems are pivotal to propose and explore effective strategies to alleviate those issues. In recent years, diverse advanced characterization techniques have been developed, which deepen insights into the problematic interface from physical, chemical, electrochemical, and mechanochemical perspectives. Herein, electrode interfaces and their fundamental knowledge in sulfide‐based ASSLBs are first clarified. Second, various emerging characterizations are overviewed to illustrate the interfacial issues on both oxide cathode/sulfide SE and Li anode/sulfide SE interfaces. Meanwhile, advantages and disadvantages of each characterization techniques are explicated. Finally, an outlook of advanced characterizations that are specifically adapted for interface analysis in sulfide‐based ASSLBs is proposed.
Statistical inference on group Rasch mixture network models
Authors: Long Yuhang , Huang Tao
Published: November 2021

In a two‐mode network, the nodes are divided into two types (primary nodes and secondary nodes), and connections exist only between nodes of different types. In reality, in such a two‐mode network, one‐mode network connections may also exist among primary nodes, and these two kinds of networks are usually not independent and coexistent. In this paper, we first propose a group Rasch mixture network model that focuses on the connections between primary nodes and secondary nodes, while incorporating the group structure and linkage information of primary nodes. We then develop a modified expectation–maximization algorithm to estimate the proposed model with a λ‐BIC method for selecting the tuning parameter. Additionally, we provide a likelihood‐ratio test statistic to examine whether the two kinds of networks are independent and implement the leave‐one‐out method to construct a network prediction rule. Finally, we establish asymptotic results and demonstrate the numerical performance of the proposed methods using both simulations and the Last.fm dataset.
A partial EM algorithm for model‐based clustering with highly diverse missing data patterns
Authors: Browne Ryan P. , McNicholas Paul D. , Findlay Christopher J.
Published: November 2021

The expectation‐maximization (EM) algorithm for incomplete data with highly diverse missing data patterns can be computationally expensive. A partial expectation‐maximization (PEM) algorithm is developed to ease this computational burden. This PEM algorithm circumvents the need for a traditional E‐step by performing a partial E‐step that reduces the Kullback‐Leibler divergence between the conditional distribution of the missing data and the distribution of the missing data given the observed data. The PEM and EM algorithms are compared in terms of computation time and convergence on simulated data. The PEM algorithm is illustrated using a latent Gaussian mixture model to cluster a white bread sensory analysis dataset.
Identification and evolutionary analysis of the metal‐tolerance protein family in eight Cucurbitaceae species
Authors: Jiang Xinchen , Yin Junliang , Wang Lixin , Xi Keyong , Zhu Xiongmeng , Li Gang , Zhu Yongxing , Liu Yiqing
Published: November 2021

Metal‐tolerance proteins (MTPs) are divalent cation transporters and play fundamental roles in plant metal tolerance and ion homeostasis. Despite that, a systematic investigation of MTPs in Cucurbitacea is still lacking. In this study, 142 MTPs were identified from 11 released genomes of 8 Cucurbitaceae species. They were phylogenetically separated into three clusters (Zn‐cation diffusion facilitator proteins [CDFs], Fe/Zn‐CDFs, and Mn‐CDFs) and further subdivided into seven groups (G1, G5, G6, G7, G8, G9, and G12). Characterization analysis revealed that most MTPs were plasma membrane‐located hydrophobic proteins. Motif and exon/intron analysis showed that members in the same group contained similar conserved motifs and gene structures. Moreover, 98 pairs of segmental‐like duplication events were found. The nonsynonymous/synonymous substitution ratios between each pair were less than 1, implying that Cucurbitaceae MTPs were under purification selection. Expression profiling suggested that several MTP genes, such as CsCLMTP1, CmeMTP3, LsMTP3, and Cl97103MTP3, were constitutively expressed in corresponding Cucurbitaceae species, and their expression levels were not significantly altered by NaCl, drought, or pathogen infection. The expression patterns of cucumber MTP genes under Zn2+, Cu2+, Mn2+, and Cd2+ stress were studied by quantitative real‐time polymerase chain reaction and the results showed that these MTPs were induced by at least one metal ion, suggesting their involvement in metal tolerance or transportation. The identification and comprehensive investigation of MTP family members will provide a basis for the analysis of ion transport functions and ion tolerance mechanisms of Cucurbitaceae MTPs.
Information sourcing by dog owners in the UK: Resource selection and perceptions of knowledge
Authors: Kuhl Christina Ann , Dean Rachel , Quarmby Caroline , Lea Richard Graham
Published: November 2021

Background

Dogs are a popular pet in the UK. Information resources utilised by dog owners can influence welfare at acquisition and throughout a dog's lifetime. This study determined where UK dog owners source information, and how perceptions relating to pedigree dog breeding and health may influence this process.

Methods

This cross‐sectional study used online questionnaires to explore the information resources used by dog owners and their perceptions of veterinary surgeons’ and dog breeders’ knowledge.

Results

Overall, 1336 responses were collected (useable responses: 1167). Data indicated most owners conducted research before getting a dog, with the internet, books, breeders and friends or family among the most popular resources used. Preferred sources of information during a dogs’ lifetime included the internet, talking to veterinary surgeons and reading books. Veterinary surgeons were the most popular source for health advice. Pedigree dog owners perceived veterinary surgeons and breeders to be equally knowledgeable on canine inherited diseases. However, veterinary surgeons were perceived as being more knowledgeable on inherited disease screening programmes and breeders more knowledgeable on dog breeding.

Conclusion

This study highlights the information resources preferred by dog owners, providing an opportunity to maximise access to reliable sources of information to improve dog welfare.
Muon g − 2 from millicharged hidden confining sector
Authors: Bai Yang , Lee Seung J. , Son Minho , Ye Fang
Published: November 2021

Abstract

We provide a novel explanation to the muon g − 2 excess with new physics contributions at the two-loop level. In this scenario, light millicharged particles are introduced to modify the photon vacuum polarization that contributes to muon g − 2 at one additional loop. The muon g − 2 excess can be explained with the millicharged particle mass mχ around 10 MeV and the product of the multiplicity factor and millicharge squared of Nχε2 ∼ 10−3. The minimal model faces severe constraints from direct searches at fixed-target experiments and astrophysical observables. However, if the millicharged particles are also charged under a hidden confining gauge group SU(Nχ) with a confinement scale of MeV, hidden-sector hadrons are unstable and can decay into neutrinos, which makes this scenario consistent with existing constraints. This explanation can be well tested at low-energy lepton colliders such as BESIII and Belle II as well as other proposed fixed-target experiments.
Regge conformal blocks from the Rindler-AdS black hole and the pole-skipping phenomena
Authors: Kim Keun-Young , Lee Kyung-Sun , Nishida Mitsuhiro
Published: November 2021

Abstract

We study a holographic construction of conformal blocks in the Regge limit of four-point scalar correlation functions by using coordinates of the two-sided Rindler-AdS black hole. As a generalization of geodesic Witten diagrams, we construct diagrams with four external scalar fields in the Rindler-AdS black hole by integrating over two half-geodesics between the centers of Penrose diagrams and points at the AdS boundary. We demonstrate that late-time behaviors of the diagrams coincide with the Regge behaviors of conformal blocks. We also point out their relevance with the pole-skipping phenomena by showing that the near-horizon analysis of symmetric traceless fields with any integer spin in the Rindler-AdS black hole can capture the Regge behaviors of conformal blocks.
Q-balls meet fuzzballs: non-BPS microstate geometries
Authors: Ganchev Bogdan , Houppe Anthony , Warner Nicholas P.
Published: November 2021

Abstract

We construct a three-parameter family of non-extremal microstate geometries, or “microstrata”, that are dual to states and deformations of the D1-D5 CFT. These families are non-extremal analogues of superstrata. We find these microstrata by using a Q-ball-inspired Ansatz that reduces the equations of motion to solving for eleven functions of one variable. We then solve this system both perturbatively and numerically and the results match extremely well. We find that the solutions have normal mode frequencies that depend upon the amplitudes of the excitations. We also show that, at higher order in perturbations, some of the solutions, having started with normalizable modes, develop a “non-normalizable” part, suggesting that the microstrata represent states in a perturbed form of the D1-D5 CFT. This paper is intended as a “Proof of Concept” for the Q-ball-inspired approach, and we will describe how it opens the way to many interesting follow-up calculations both in supergravity and in the dual holographic field theory.
On improving NLO merging for $$ \mathrm{t}\overline{\mathrm{t}}\mathrm{W} $$ production
Authors: Frederix Rikkert , Tsinikos Ioannis
Published: November 2021

Abstract

We introduce an improvement to the FxFx matrix element merging procedure for pp →$$ t\overline{t}W $$
t

t
¯

W
production at NLO in QCD with one and/or two additional jets. The main modification is an improved treatment of jets that are not logarithmically enhanced in the low transverse-momentum regime. We provide predictions for the inclusive cross section and the $$ t\overline{t}W $$
t

t
¯

W
differential distributions including parton-shower effects. Taking also the NLO EW corrections into account, this results in the most-accurate predictions for this process to date. We further proceed to include the on-shell LO decays of the $$ t\overline{t}W $$
t

t
¯

W
including the tree-level spin correlations within the narrow-width approximation, focusing on the multi-lepton signatures studied at the LHC. We find a ∼30% increase over the NLO QCD prediction and large non-flat K-factors to differential distributions.
Diagrammar of physical and fake particles and spectral optical theorem
Authors: Anselmi Damiano
Published: November 2021

Abstract

We prove spectral optical identities in quantum field theories of physical particles (defined by the Feynman iϵ prescription) and purely virtual particles (defined by the fakeon prescription). The identities are derived by means of purely algebraic operations and hold for every (multi)threshold separately and for arbitrary frequencies. Their major significance is that they offer a deeper understanding on the problem of unitarity in quantum field theory. In particular, they apply to “skeleton” diagrams, before integrating on the space components of the loop momenta and the phase spaces. In turn, the skeleton diagrams obey a spectral optical theorem, which gives the usual optical theorem for amplitudes, once the integrals on the space components of the loop momenta and the phase spaces are restored. The fakeon prescription/projection is implemented by dropping the thresholds that involve fakeon frequencies. We give examples at one loop (bubble, triangle, box, pentagon and hexagon), two loops (triangle with “diagonal”, box with diagonal) and arbitrarily many loops. We also derive formulas for the loop integrals with fakeons and relate them to the known formulas for the loop integrals with physical particles.
Attractors with large complex structure for one-parameter families of Calabi-Yau manifolds
Authors: Candelas Philip , Kuusela Pyry , McGovern Joseph
Published: November 2021

Abstract

The attractor equations for an arbitrary one-parameter family of Calabi-Yau manifolds are studied in the large complex structure region. These equations are solved iteratively, generating what we term anN-expansion, which is a power series in the Gromov-Witten invariants of the manifold. The coefficients of this series are associated with integer partitions. In important cases we are able to find closed-form expressions for the general term of this expansion. To our knowledge, these are the first generic solutions to attractor equations that incorporate instanton contributions. In particular, we find a simple closed-form formula for the entropy associated to rank two attractor points, including those recently discovered. The applications of our solutions are briefly discussed. Most importantly, we are able to give an expression for the Wald entropy of black holes that includes all genus 0 instanton corrections.
Completing the D7-brane local gaugino action
Authors: Hamada Yuta , Hebecker Arthur , Shiu Gary , Soler Pablo
Published: November 2021

Abstract

Within the ongoing debate about de Sitter (dS) vacua in string theory, different aspects of explicit dS proposals have come under intense scrutiny. One key ingredient is D7-brane gaugino condensation, which is usually treated using effective 4d supergravity. However, it is clearly more desirable to derive the relevant scalar potential directly from a local 10d Lagrangian. Such a local 10d description captures the interactions among the various localized sources and the background fields which are smeared in the 4d Lagrangian. While progress in this endeavour has recently been made, some form of non-locality related to the 4-gaugino term has remained hidden in the available proposals. We spell out the local counterterm removing the divergence that arises when integrating out the 3-form flux and which, upon dimensional reduction, serves to reproduce the relevant part of the 4d supergravity action. This is both a step towards a more complete understanding of 10d type-IIB supergravity as well as specifically towards better control of dS constructions in string theory involving gaugino condensation.
Dark matter interacting via a massive spin-2 mediator in warped extra-dimensions
Authors: de Giorgi A. , Vogl S.
Published: November 2021

Abstract

We study dark matter interacting via a massive spin-2 mediator. To have a consistent effective theory for the spin-2 particle, we work in a warped extra-dimensional model such that the mediator(s) are the Kaluza-Klein (KK) modes of the 5D graviton. We pay close attention to dark matter annihilations into KK-gravitons. Due to the high energy behavior of longitudinal modes of spin-2 fields, these channels exhibit a tremendous growth at large center of mass energies $$ \sqrt{s} $$

s

if only one spin-2 mediator is considered. For the first time, we include the full KK-tower in this dark matter production process and find that this growth is unphysical and cancels once the full field content of the extra-dimensional theory is taken into account. Interestingly, this implies that it is not possible to approximate the results obtained in the full theory with a reduced set of effective interactions once $$ \sqrt{s} $$

s

is greater than the first graviton mass. This casts some doubt on the universal applicability of previous studies with spin-2 mediators within an EFT framework and prompts us to revisit the phenomenological allowed parameter space of gravitationally interacting scalar dark matter in warped extra-dimensions.
Matching of fracture functions for SIDIS in target fragmentation region
Authors: Chen K.B. , Ma J.P. , Tong X.B.
Published: November 2021

Abstract

In the target fragmentation region of Semi-Inclusive Deep Inelastic Scattering, the diffractively produced hadron has small transverse momentum. If it is at order of ΛQCD, it prevents to make predictions with the standard collinear factorization. However, in this case, differential cross-sections can be predicted by the factorization with fracture functions, diffractive parton distributions. If the transverse momentum is much larger than ΛQCD but much smaller than Q which is the virtuality of the virtual photon, both factorizations apply. In this case, fracture functions can be factorized with collinear parton distributions and fragmentation functions. We study the factorization up to twist-3 level and obtain gauge invariant results. They will be helpful for modeling fracture functions and useful for resummation of large logarithm of the transverse momentum appearing in collinear factorization.
Sharp $$L_p$$ estimates for paraproducts on general measure spaces
Authors: Osękowski Adam
Published: November 2021

The paper contains the identification of the $$L_p$$

L
p

norms of paraproducts, defined on general measure spaces equipped with a dyadic-like structure. The proof exploits the Bellman function method.
Carbon dioxide inhibits COVID-19-type proinflammatory responses through extracellular signal-regulated kinases 1 and 2, novel carbon dioxide sensors
Authors: Galganska Hanna , Jarmuszkiewicz Wieslawa , Galganski Lukasz
Published: November 2021

Mitogen-activated protein kinase (MAPK) signalling pathways are crucial for developmental processes, oncogenesis, and inflammation, including the production of proinflammatory cytokines caused by reactive oxygen species and upon severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. There are no drugs that can effectively prevent excessive inflammatory responses in endothelial cells in the lungs, heart, brain, and kidneys, which are considered the main causes of severe coronavirus disease 2019 (COVID-19). In this work, we demonstrate that human MAPKs, i.e. extracellular signal-regulated kinases 1 and 2 (ERK1/2), are CO2 sensors and CO2 is an efficient anti-inflammatory compound that exerts its effects through inactivating ERK1/2 in cultured endothelial cells when the CO2 concentration is elevated. CO2 is a potent inhibitor of cellular proinflammatory responses caused by H2O2 or the receptor-binding domain (RBD) of the spike protein of SARS-CoV-2. ERK1/2 activated by the combined action of RBD and cytokines crucial for the development of severe COVID-19, i.e. interferon-gamma (IFNγ) and tumour necrosis factor-α (TNFα), are more effectively inactivated by CO2 than by dexamethasone or acetylsalicylic acid in human bronchial epithelial cells. Previously, many preclinical and clinical studies showed that the transient application of 5–8% CO2 is safe and effective in the treatment of many diseases. Therefore, our research indicates that CO2 may be used for the treatment of COVID-19 as well as the modification of hundreds of cellular pathways.
Cheeger Sets for Rotationally Symmetric Planar Convex Bodies
Authors: Cañete Antonio
Published: November 2021

In this note we obtain some properties of the Cheeger set $$C_\varOmega $$

C
Ω

associated to a k-rotationally symmetric planar convex body $$\varOmega $$
Ω
. More precisely, we prove that $$C_\varOmega $$

C
Ω

is also k-rotationally symmetric and that the boundary of $$C_\varOmega $$

C
Ω

touches all the edges of $$\varOmega $$
Ω
.
Genetic and physiological characterization of sunflower resistance provided by the wild-derived OrDeb2 gene against highly virulent races of Orobanche cumana Wallr
Authors: Fernández-Aparicio Mónica , del Moral Lidia , Muños Stéphane , Velasco Leonardo , Pérez-Vich Begoña
Published: November 2021

Key message

OrDeb2 confers post-attachment resistance to Orobanche cumana and is located in a 1.38 Mbp genomic interval containing a cluster of receptor-like kinase and receptor-like protein genes with nine high-confidence candidates.

Sunflower broomrape is a holoparasitic angiosperm that parasitizes on sunflower roots, severely constraining crop yield. Breeding for resistance is the most effective method of control. OrDeb2 is a dominant resistance gene introgressed into cultivated sunflower from a wild-related species that confers resistance to highly virulent broomrape races. The objectives of this study were as follows: (i) locate OrDeb2 into the sunflower genome and determine putative candidate genes and (ii) characterize its underlying resistance mechanism. A segregating population from a cross between the sunflower resistant line DEB2, carrying OrDeb2, and a susceptible line was phenotyped for broomrape resistance in four experiments, including different environments and two broomrape races (FGV and GTK). This population was also densely genotyped with microsatellite and SNP markers, which allowed locating OrDeb2 within a 0.9 cM interval in the upper half of Chromosome 4. This interval corresponded to a 1.38 Mbp genomic region of the sunflower reference genome that contained a cluster of genes encoding LRR (leucine-rich repeat) receptor-like proteins lacking a cytoplasmic kinase domain and receptor-like kinases with one or two kinase domains and lacking an extracellular LRR region, which were valuable candidates for OrDeb2. Rhizotron and histological studies showed that OrDeb2 determines a post-attachment resistance response that blocks O. cumana development mainly at the cortex before the establishment of host-parasite vascular connections. This study will contribute to understand the interaction between crops and parasitic weeds, to establish durable breeding strategies based on genetic resistance and provide useful tools for marker-assisted selection and OrDeb2 map-based cloning.
Child marriage and infant mortality: causal evidence from Ethiopia
Authors: Garcia-Hombrados Jorge
Published: November 2021

This study assesses the causal effect of child marriage on infant mortality. Using age discontinuities in exposure to a law that raised the legal age of marriage for women in Ethiopia, the study estimates that a 1-year delay in a woman’s age at cohabitation during her teenage years reduces the probability of her first-born child dying during infancy by 3.8 percentage points. This impact is closely linked to the effect of delaying cohabitation on women’s age at first birth.
Cannon–Thurston maps for $${{\,\textrm{CAT}\,}}(0)$$ groups with isolated flats
Authors: Benjamin Beeker , Cordes Matthew , Gardam Giles , Gupta Radhika , Stark Emily
Published: November 2021

Mahan Mitra (Mj) proved Cannon–Thurston maps exist for normal hyperbolic subgroups of a hyperbolic group (Mitra in Topology, 37(3):527–538, 1998). We prove that Cannon–Thurston maps do not exist for infinite normal hyperbolic subgroups of non-hyperbolic $${{\,\textrm{CAT}\,}}(0)$$

CAT

(
0
)

groups with isolated flats with respect to the visual boundaries. We also show Cannon–Thurston maps do not exist for infinite infinite-index normal $${{\,\textrm{CAT}\,}}(0)$$

CAT

(
0
)

subgroups with isolated flats in non-hyperbolic $${{\,\textrm{CAT}\,}}(0)$$

CAT

(
0
)

groups with isolated flats. We obtain a structure theorem for the normal subgroups in these settings and show that outer automorphism groups of hyperbolic groups have no purely atoroidal $$\mathbb {Z}^2$$

Z

2

subgroups.
Jacques Tits motivic measure
Authors: Tabuada Gonçalo
Published: November 2021

In this article we construct a new motivic measure called theJacques Tits motivic measure. As a first main application, we prove that two Severi-Brauer varieties (or, more generally, two twisted Grassmannian varieties), associated to 2-torsion central simple algebras, have the same class in the Grothendieck ring of varieties if and only if they are isomorphic. In addition, we prove that if two Severi-Brauer varieties, associated to central simple algebras of period$$\{3, 4, 5, 6\}$${3,4,5,6}, have the same class in the Grothendieck ring of varieties, then they are necessarily birational to each other. As a second main application, we prove that two quadric hypersurfaces (or, more generally, two involution varieties), associated to quadratic forms of dimension 6 or to quadratic forms of arbitrary dimension defined over a base fieldkwith$$I^3(k)=0$$I3(k)=0, have the same class in the Grothendieck ring of varieties if and only if they are isomorphic. In addition, we prove that the latter main application also holds for products of quadric hypersurfaces.
No antidepressant-like acute effects of bright light on emotional information processing in healthy volunteers
Authors: Kaltenboeck Alexander , Ruzickova Tereza , Breunhölder Veronika , Zghoul Tarek , Cowen Philip J. , Harmer Catherine J.
Published: November 2021

Rationale

Bright light treatment (BLT) is an efficacious antidepressant intervention, but its mechanism of action is not well understood. Antidepressant drugs acutely affect how emotional information is processed, pushing the brain to prioritise positive relative to negative input. Whether BLT could have a similar effect is not known to date.

Objective

To test whether BLT acutely influences emotional information processing similar to antidepressant drugs, using an established healthy volunteer assay.

Methods

Following a double-blind, parallel-group design, 49 healthy volunteers (18–65 years, 26 females) were randomly allocated to 60-min BLT (≥ 10,000 lux) or sham-placebo treatment early in the morning in autumn/winter. Immediately after treatment, emotional information processing was assessed using the Oxford Emotional Test Battery, a validated set of behavioural tasks tapping into emotional information processing in different cognitive domains. Participants also completed questionnaires before and after treatment to assess changes in subjective state.

Results

The BLT group did not show significantly more positively biased emotional information processing compared to the placebo group (p > 0.05 for all measures). After adjustment for pre-treatment scores, there were also no significant post-treatment differences between groups in subjective state (p > 0.05 for all measures).

Conclusions

BLT did not show immediate effects on emotional information processing in an established healthy volunteer assay. Thus, BLT might exert its clinical effects through a different (cognitive) mechanism than other antidepressant interventions. Future studies should corroborate this finding including clinical populations and more intensive treatment regimes, and control for potential chronobiological effects.
Weak Convergence Rates for Spatial Spectral Galerkin Approximations of Semilinear Stochastic Wave Equations with Multiplicative Noise
Authors: Jacobe de Naurois Ladislas , Jentzen Arnulf , Welti Timo
Published: November 2021

Stochastic wave equations appear in several models for evolutionary processes subject to random forces, such as the motion of a strand of DNA in a liquid or heat flow around a ring. Semilinear stochastic wave equations can typically not be solved explicitly, but the literature contains a number of results which show that numerical approximation processes converge with suitable rates of convergence to solutions of such equations. In the case of approximation results for strong convergence rates, semilinear stochastic wave equations with both additive or multiplicative noise have been considered in the literature. In contrast, the existing approximation results for weak convergence rates assume that the diffusion coefficient of the considered semilinear stochastic wave equation is constant, that is, it is assumed that the considered wave equation is driven by additive noise, and no approximation results for multiplicative noise are known. The purpose of this work is to close this gap and to establish essentially sharp weak convergence rates for spatial spectral Galerkin approximations of semilinear stochastic wave equations with multiplicative noise. In particular, our weak convergence result establishes as a special case essentially sharp weak convergence rates for the continuous version of the hyperbolic Anderson model. Our method of proof makes use of the Kolmogorov equation and the Hölder-inequality for Schatten norms.