bluuebunny/crossref_metadata_2025_split huggingface dataset:
Light – current characteristics of high-power pulsed semiconductor lasers (1060 nm) operating at increased (up to 90 °C) temperatures
Authors: Gavrina P.S. , Podoskin A.A. , Fomin E.V. , Veselov D.A. , Shamakhov V.V. , Slipchenko S.O. , Pikhtin N.A. , Kop’ev P.S. 
Published: January 2021

AbstractPulsed radiative characteristics of high-power semiconductor lasers based on an asymmetric InGaAs/AlGaAs/GaAs heterostructure with an active region including two quantum wells and a gradient waveguide on the side of the p-emitter are studied. It is shown that the use of the proposed design allows efficient laser operation under pumping by 100-ns current pulses in the temperature range 25 – 90 °C. The lasers with a Fabry – Perot cavity 2900 μm long demonstrated peak powers of 62 W (injection current 123 A) and 43 W (122 A) at temperatures of 25 and 90 °C, respectively. It is found that at room temperature and currents of ∼50A, a decrease in the cavity length to 600 μm does not cause a decrease in the output power with respect to the power of lasers with a long (2900 μm) cavity. An increase in temperature to 90 °C at high injection currents leads to a sharp decrease in the radiative efficiency of lasers with a short (600 μm) cavity and to the change of their operation regime to the two-band lasing.
A genome-scale CRISPR screen reveals factors regulating Wnt-dependent renewal of mouse gastric epithelial cells
Authors: Murakami Kazuhiro , Terakado Yumi , Saito Kikue , Jomen Yoshie , Takeda Haruna , Oshima Masanobu , Barker Nick 
Published: January 2021

Significance
Wnt activation is critically important during both early development and throughout adulthood for the maintenance and regeneration of tissue-resident stem cells. However, the underlying mechanism regulating Wnt-dependent epithelial renewal and differentiation in the stomach remains poorly understood. Here we apply genome-scale CRISPR-Cas9 knockout screening to three-dimensional ex vivo stomach organoids to reveal important mechanistic insight into Wnt-dependent epithelial renewal in mouse gastric epithelia. Our organoid-based screening strategy can be readily applied to a wide variety of organoids derived from different sources, potentially providing important insights on multiple biological phenomena.
Human subjects exploit a cognitive map for credit assignment
Authors: Moran Rani , Dayan Peter , Dolan Raymond J. 
Published: January 2021

Significance
Credit assignment (CA) to relevant actions poses a challenge because one is often flooded with reward feedback that is not easily causally attributed. We addressed this issue in a reinforcement learning framework wherein choice is mutually controlled by value-caching model-free (MF) and prospective, planning model-based (MB) systems. We find knowledge, stored in a cognitive map, filters exuberant reward feedback to guide CA in both systems but based on different attribute dimensions. In MF, CA is boosted for outcomes that are relevant (causally related) to one’s choice, whereas in MB, CA is enhanced for outcomes that attract greater attention during the deliberation process that preceded a choice. We consider normative and mechanistic accounts, including how these processes are instrumental to adaptation.
Evolutionarily stable strategies in stable and periodically fluctuating populations: The Rosenzweig–MacArthur predator–prey model
Authors: Grunert Katrin , Holden Helge , Jakobsen Espen R. , Stenseth Nils Chr. 
Published: January 2021

Significance
Many evolutionary studies of ecological systems assume, explicitly or implicitly, ecologically stable population dynamics. Ecological analyses typically assume, on the other hand, no evolution. We study a model (using predator–prey dynamics as an example) combining ecology and evolution within the same framework. For this purpose, we use the evolutionarily stable strategies (ESSs) framework, emphasizing that evolutionary change, in general, will occur as a result of mutant strategies being able to invade a population. The significance of our contribution is to derive mathematical conditions for the existence of an ESS in a periodically limit-cycle ecological system.
Major alterations in the mononuclear phagocyte landscape associated with COVID-19 severity
Authors: Kvedaraite Egle , Hertwig Laura , Sinha Indranil , Ponzetta Andrea , Hed Myrberg Ida , Lourda Magda , Dzidic Majda , Akber Mira , Klingström Jonas , Folkesson Elin , Muvva Jagadeeswara Rao , Chen Puran , Gredmark-Russ Sara , Brighenti Susanna , Norrby-Teglund Anna , Eriksson Lars I. , Rooyackers Olav , Aleman Soo , Strålin Kristoffer , Ljunggren Hans-Gustaf , Ginhoux Florent , Björkström Niklas K. , Henter Jan-Inge , Svensson Mattias ,   Karolinska KI/K COVID-19 Study Group, Sandberg John Tyler , Bergsten Helena , Björkström Niklas K , Brighenti Susanna , Buggert Marcus , Butrym Marta , Chambers Benedict J , Chen Puran , Cornillet Martin , Cuapio Angelica , Lozano Isabel Diaz , Dzidic Majda , Emgård Johanna , Flodström-Tullberg Malin , Gorin Jean-Baptiste , Gredmark-Russ Sara , Haroun-Izquierdo Alvaro , Hertwig Laura , Kalsum Sadaf , Klingström Jonas , Kokkinou Efthymia , Kvedaraite Egle , Ljunggren Hans-Gustaf , Marquardt Nicole , Lourda Magdalini , Maleki Kimia T , Malmberg Karl-Johan , Michaëlsson Jakob , Mjösberg Jenny , Moll Kirsten , Muvva Jagadeeswara Rao , Norrby-Teglund Anna , Medina Laura M Palma , Parrot Tiphaine , Radler Lena , Ringqvist Emma , Sandberg Johan K , Sekine Takuya , Soini Tea , Svensson Mattias , Tynell Janne , von Kries Andreas , Wullimann David , Perez-Potti André , Rivera-Ballesteros Olga , Maucourant Christopher , Varnaite Renata , Akber Mira , Berglin Lena , Brownlie Demi , Loreti Marco Giulio , Sohlberg Ebba , Kammann Tobias , Henriksson Elisabeth , Strålin Kristoffer , Aleman Soo , Sönnerborg Anders , Dillner Lena , Färnert Anna , Glans Hedvig , Nauclér Pontus , Rooyackers Olav , Mårtensson Johan , Eriksson Lars I , Persson Björn P , Grip Jonathan , Unge Christian 
Published: January 2021

Significance
While broad efforts toward getting an overview of immune cell and soluble factor alterations in COVID-19 are under way, a deep and comprehensive understanding of the mononuclear phagocyte system, including circulating progenitors, is still largely lacking. This study provides a reference for the mononuclear phagocyte response to SARS-CoV-2 infection and unravels mononuclear phagocyte dysregulations associated with severe COVID-19.
Tocopherol controls D1 amino acid oxidation by oxygen radicals in Photosystem II
Authors: Kumar Aditya , Prasad Ankush , Sedlářová Michaela , Kale Ravindra , Frankel Laurie K. , Sallans Larry , Bricker Terry M. , Pospíšil Pavel 
Published: January 2021

Significance
During oxygenic photosynthesis Photosystem II is damaged by reactive oxygen species (ROS). It is known that α-tocopherol protects the photosystem from a subset of this oxidative damage. The sites that were protected and the mechanisms leading to protein damage had not been determined. Herein, we identify the ROS responsible for damage on the reducing side of Photosystem II, the protein residues that are damaged by these ROS, and we propose a model localizing α-tocopherol within the photosystem yielding the observed protection.
Microbes in biogeochemical cycles: a perspective on climate resilient agriculture
Authors: Gurung Aditi , Mattoo Rohini 
Published: January 2021

Abstract
Microorganisms, which are ubiquitous players in all major agro-ecosystems, play important roles in biogeochemical cycles. Due to anthropogenic activities and current practices of agriculture, there has been interference in the natural cycling of essential elements and nutrients. A harmony in the functioning of natural biogeochemical cycles in the soil is essential for maintaining all life on Earth. Therefore, usage of beneficial soil microorganisms is important for sustaining agriculture due to poor soil health conditions that prevail because of excessive chemical inputs both in the past and present to increase crop yields. In this review, we focus on how the terrestrial soil microbes are involved in the interplay between biogeochemical cycles, sustainable agricultural practices, and climate change. We have highlighted the mechanisms by which microbes, through aiding the mineralization processes, support plant growth in cycling of carbon, nitrogen, phosphorus, and sulfur. Microorganisms further support plant growth to adapt to climate change although few specific mechanisms are known, but many others by which they aid plants remain enigmatic. Despite the various gaps that remain, we advocate that coupling biogeochemical cycles research with sustainable agricultural practices using plant-microbe interchange is highly warranted. Therefore, to feed a growing global population and to preserve ecosystem functions, we propose that the agricultural practices should be conducted in a manner to regulate greenhouse gases release and safeguard our environmental resources due to climate change.
Double-objective optimization of electro-thermal (E-T) micro-actuator for fiber switch
Authors: Chen Hao , Wang Xin-jie , Cao Yun , Wang Jiong , Xi Zhan-wen , Nie Wei-rong 
Published: January 2021

Abstract
In this paper, a novel optimization method, in which composed of the genetic algorithm, particle swarm optimization (GA–PSO) and improved gradient descent algorithm, are used to conduct a double-objective optimization for the U-shaped actuator. In the procedure of optimization, two objectives, i.e. force and displacement, and four main sizes are utilized. Before, the deep reactive-ion etch (DRIE) technology is applied to the fabrication of the U-shaped actuator. When different voltages are applied on the actuator, the displacement obtained from numerical calculation always shows a good agreement with that from experiment by edge detection algorithm. Similar phenomenon can be also seen when an external force supplied by the nanoindentation system FemtoTools in the experiment is loaded on the actuator. Based on the validated simulation model of the U-shaped actuator, the improved gradient descent method ensures its displacement very close to 50 µm (target displacement) while the GA–PSO algorithm is used to maximize the output force. In this procedure, the hybrid optimization method implemented by Matlab is incorporated into ANSYS simulation. Preliminary analysis shows that the displacement and force of the particles in each iteration concentrate together with the iteration growing. Fine convergence, whose velocity only depends on the number of particle in the algorithm, is also found in each optimization. Furthermore, the optimized actuators have homologous value of the size variables. At 15 V voltage, the displacement and largest output force of the U-shaped actuator are 2 mN and 50.1 µm, respectively. Finally, an actuator with 30% improvement of the output force is obtained when the displacement condition is meet. According to the optimization result and further parametric scanning simulation analysis, the design range and fabrication error of the sizes of the U-shaped actuator are obtained.
Rotational speed measurements of small spherical particles driven by acoustic viscous torques utilizing an optical trap
Authors: Lamprecht Andreas , Goering Christoph , Schaap Iwan A T , Dual Jurg 
Published: January 2021

Abstract
Two orthogonal standing acoustic waves, generated by piezoelectric excitation, can form a two-dimensional pressure field in microfluidic devices. A phase difference of the excitation waves can be employed to rotate spherical µm-sized silica particles by a torque mediated through the viscous boundary δ around the particle. The measurement of the rotational rate is, so far, limited to high-speed cameras and their frame rate, and gets increasingly difficult when the sphere gets smaller. We report here a new method for measuring the rotational rate of µm sized spherical particles. We utilize an optical trap with high-speed position detection to overcome the frame rate limitation of wide field image recording. The power spectrum of an optically trapped, rotating particle reveals additional peaks corresponding to the rotational frequencies—compared to a non-rotating particle. We validate our method at low rotational rates against high-speed video observation. To demonstrate the potential of this method we addressed a recent controversy about the rotation of particles with a relatively large viscous boundary layer δ. We measured steady-state rotational rates up to 229 Hz (13.8 × 103 rpm) for a particle with a radius R ≈ δ. Recent numerical research suggests that in this regime the existing theoretical approach (valid for

R
≫
δ

) overpredicts the steady-state rotational rate by a factor of 10. With our new method we also confirm the numerical results experimentally.
A combined laboratory and synchrotron in-situ photoemission study of the rutile TiO2 (110)/water interface
Authors: Byrne Conor , Zahra Khadisha M , Dhaliwal Simran , Grinter David C , Roy Kanak , Garzon Wilson Q , Held Georg , Thornton Geoff , Walton Alex S 
Published: January 2021

Abstract

In-situ analysis of the TiO2/water interface via near ambient pressure–x-ray photoelectron spectroscopy (NAP–XPS) is demonstrated in both a lab based system (NAP-cell configuration) and synchrotron endstation (backfill configuration). Ultra-thin wetting layers of liquid water (∼10 nm) are formed on a rutile TiO2 surface with minimal contamination present in addition to unique insight during the growth of the liquid films as indicated via NAP–XPS, in-situ sample temperature and background vapour pressure monitoring. Chemical changes at the solid/liquid interface are also demonstrated via healing of Ti3+ surface defect states. Photon depth profiling of the as grown liquid layers indicate that the formed films are ultra-thin (∼10 nm) and likely to be continuous in nature. This work demonstrates a novel and flexible approach for studying the solid/liquid interface via NAP–XPS which is readily integrated with any form of NAP–XPS system, thereby making a critical interface of study available to a wide audience of researchers for use in operando electrochemical and photocatalytic research.
Corrigendum: Role of the electron–phonon coupling in tuning the thermal boundary conductance at metal-dielectric interfaces by inserting ultrathin metal interlayers (2021 J. Phys.: Condens. Matter
33 085702)
Authors: Oommen Shany Mary , Pisana Simone 
Published: January 2021

Abstract
Some typographical errors were made in the original version of the manuscript associated with the value of the electron–phonon coupling constant for Ta, which are corrected here.
Feature extraction method of rolling bearing based on adaptive divergence matrix linear discriminant analysis
Authors: Shi Mingfeng , Cao Zheng , Liu Yongbin , Liu Fang , Lu Siliang , Li Guoli 
Published: January 2021

Abstract
Status feature extraction is crucial to bearing fault diagnosis and the maintenance of rotating machinery. There are many challenges in extracting the effective status features from vibration signals for bearing fault diagnosis. A linear discriminant analysis (LDA) based on an adaptive divergence matrix (ALDA) is proposed to extract the status features of rolling bearings in this paper. The main idea of the method is that the sample clustering evaluation index (SI) is used to adjust the weight of the within-class divergence matrix of the LDA algorithm to reduce the cross or overlap among different types of samples, especially for the marginal samples. In the method, vibration signals of the rolling bearing under different running conditions are acquired, and the original features, such as time domain and frequency domain, are extracted from the vibration signals. Then, the optimal exponential weight of the within-class divergence matrix of the LDA is selected with the maximum SI. The optimal fusion status features of the bearing under different conditions were extracted by the ALDA algorithm from the original features. Finally, the fusion features were identified by the support vector machine classifier to verify the effectiveness of the proposed method. The experimental results show that the bearing status features extracted by ALDA can be used to identify the bearing status effectively.
Low-threshold upconverted single-mode lasing from CdS hexagonal microcavities
Authors: Mi Yang , Kong Lei , Wu Yaoyao , Shi Jinchun , Luo Sheng-Nian 
Published: January 2021

Abstract
Upconversion micro/nanolasers are promising in fundamental physics research and practical applications. However, due to the limitation of gain medium and cavity quality, such lasers still suffer from a high lasing threshold (P
th). Herein, upconverted whispering-gallery-mode lasing by two-photon absorption is achieved from CdS microplatelets with single-mode emission and low threshold (∼1.2 mJ cm−2). The threshold is three times lower than the best reported value in previous CdS upconversion lasers. Moreover, wavelength-tunable upconverted single-mode lasing is demonstrated from 510.4 to 518.9 nm with narrow linewidths around 0.85 nm, which is further verified through numerical simulations. In addition, the size-dependent lasing behavior is realized from single-mode to multimode oscillation; the corresponding lasing threshold decreases with increasing cavity edge length (L), following a P
th ∝ 1/L
2 relationship. These results underscore the promise of CdS microplatelets for developing chip-level frequency upconversion lasers.
Tailored negative/positive photoresponse of BP via doping
Authors: Liu Yue , Tan Yang , Liu Yanran , Jiang Xiantao , Zhang Han , Chen Feng 
Published: January 2021

Abstract
Black phosphorus (BP) is a promising material for photodetectors due to its excellent and broadband photoresponse. To realize a wide application of BP in photodetection, there is a continuous eagerness for new approaches to tailor photoresponse of BP for a specific purpose, such as high sensitivity and switching of negative/positive responses. Here, we demonstrate that the ion irradiation with controllable conditions can enhance the photoresponsivity of BP for two orders compared to the pristine one, and can select the positive/negative photoresponse of the BP. The range of the tailored photoresponse covers the whole optical spectrum, ranging from the visible (532 nm) to the mid-infrared (10 μm). This work shows a pathway to modulate the photoresponse of BP, which opens new possibilities for potential photonic applications.
Ultralow dark current infrared photodetector based on SnTe quantum dots beyond 2 μm at room temperature
Authors: Feng Yajun , Chang Huicong , Liu Yingbo , Guo Nan , Liu Junku , Xiao Lin , Li Lishuo 
Published: January 2021

Abstract
Quantum dots (QDs) are promising materials used for room temperature mid-infrared (MIR) photodetector due to their solution processing, compatibility with silicon and tunability of band structure. Up to now, HgTe QDs is the most widely studied material for MIR detection. However, photodetectors assembled with HgTe QDs usually work under cryogenic cooling to improve photoelectric performance, greatly limiting their application at room temperature. Here, less-toxic SnTe QDs were controllably synthesized with high crystallinity and uniformity. Through proper ligand exchange and annealing treatment, the photoconductive device assembled with SnTe QDs demonstrated ultralow dark current and broadband photo-electric response from visible light to 2 μm at room temperature. In addition, the visible and near infrared photo-electric performance of the SnTe QDs device were well maintained even standing 15 d in air. This excellent performance was due to the effective protection of the ligand on surface of the QDs and the effective transport of photo-carriers between the SnTe interparticles. It would provide a new idea for environmentally friendly mid-IR photodetectors working at room temperature.
Boosting an anapole mode response through electromagnetic interactions beyond near-field limit in individual all-dielectric disk-ring nanostructures
Authors: Deng Yan-Hui , Yang Zhong-Jian , Hu Ma-Long , Du Xiao-Jing , He Jun 
Published: January 2021

Abstract
Anapole modes of all-dielectric nanostructures hold great promise for many nanophotonic applications. However, anapole modes can hardly couple to other modes through far-field interactions, and their near-field enhancements are dispersed widely inside the nanostructures. These facts bring challenges to the further increasing of the response of an anapole mode. Here, we theoretically show that an anapole mode response in a dielectric nanostructure can be boosted through electromagnetic interactions with the coupling distance of a wavelength scale, which is beyond both the near-field and far-field limits. The all-dielectric nanostructure consists of a disk holding an anapole mode and a ring. Both analytical calculations and numerical simulations are carried out to investigate the electromagnetic interactions in the system. It is found that the electric dipoles associated with the fields of the anapole mode on the disk undergo retardation-related interactions with the electric dipoles associated with the ring, leading to the efficiently enhanced response of the anapole mode. The corresponding near field enhancement on the disk can reaches more than 90 times for a slotted silicon disk-ring nanostructure, where the width of the slot is 10 nm. This enhancement is about 5 times larger than that of an individual slotted disk. Our results reveal the greatly enhanced anapole mode through electromagnetic couplings in all-dielectric nanostructures, and the corresponding large field enhancement could find important applications for enhanced nonlinear photonics, near-field enhanced spectroscopies, and strong photon–exciton couplings.
A spectrally bright wavelength-switchable vacuum ultraviolet source driven by quantum coherence in strong-field-ionized molecules
Authors: Wan Yuexin , Liu Zhaoxiang , Yao Jinping , Xu Bo , Chen Jinming , Zhang Fangbo , Zhang Zhihao , Qiao Lingling , Cheng Ya 
Published: January 2021

Abstract
We report generation of spectrally bright vacuum ultraviolet (VUV) and deep UV (DUV) coherent radiations at the wavelengths of 192 nm, 198 nm and 204 nm. These DUV/VUV radiations originate from resonant four-wave mixing assisted by quantum coherence in tunnel-ionized CO molecules. The electronic coherence is created when the pump pulses resonantly excite electronic transitions of CO+. The technique allows for the selective switch of DUV/VUV wavelengths provided by the abundant energy levels of molecular ions. The developed source can have arbitrary polarization states by manipulating the polarization of the pump pulse. It also exhibits a spectral bandwidth of 5∼7 cm−1, a divergence angle of 3∼5 mrad, a pulse duration of ∼10 ps, and a photon flux of ∼1010 photons/s. The superior temporal and spectral properties give rise to a broadband Raman comb in the DUV/VUV region.
Abundant wave solutions to two novel KP-like equations using an effective integration method
Authors: Ghanbari Behzad , Kuo Chun-Ku 
Published: January 2021

Abstract
In this work, two new nonlinear evolution equations arising from the B-type Kadomtsev-Petviashvili equation, called BKP-like equations, are investigated. The integration technique that used in this paper to determine the exact solutions of the equation is the generalized exponential rational function method. The examined models may be extended to diversify problems in natural phenomena, such as ocean waves. After applying the aforesaid method, abundant wave solutions are formally generated with some free parameters to exhibit various versions of propagations of traveling solitary waves. Notably, upon choosing appropriate values to free parameters, some kink and periodic waves are demonstrated in 3D figures and 2D contour plots. Most of all, the results show that free parameters drastically influence the existence of all kinds of traveling waves, including nature, profile, and stability. The method used in this paper can be easily adopted in other similar equations in mathematical physics.