bluuebunny/crossref_metadata_2025 huggingface dataset:
Progress and perspective in mechanically robust carbon aerogels
Authors: Guo Fan , Yang Cao , Xu Zhen , Gao Chao
Published: March 2022

Carbon aerogels (CAs) are emerging carbon-based cellular materials with high porosity, low density, and a variety of functions. The combination of all these unique properties contributes to their wide applications in flexible sensors, energy devices, acoustic devices, and environmental applications. However, their wide applications are strictly limited by poor mechanical robustness. The existing conflicts between mechanical robustness and the sparse network of porous materials have never received due attention. Good robustness could ensure structural integrity and performance stability for practical applications of aerogels. Here, we discuss recently emerged strategies for optimizing mechanical robustness, including cell-wall strengthening, cell-wall orientation, pore topology control, and joint reinforcement. Particularly, we conclude advanced design principles to achieve stretching elasticity of CAs without introducing intrinsically stretchable elastomers. In addition, we briefly overview the recent applications of robust CAs and provide an outlook on the open questions for obtaining more mechanically robust CAs.
Dislocation dynamics in α-Ga2O3 micropillars from selective-area epitaxy to epitaxial lateral overgrowth
Authors: Zhang Y. J. , Wang Z. P. , Kuang Y. , Gong H. H. , Hao J. G. , Sun X. Y. , Ren F.-F. , Yang Y. , Gu S. L. , Zheng Y. D. , Zhang R. , Ye J. D.
Published: March 2022

Epitaxial lateral overgrowth (ELO) is an effective strategy to achieve metastable phased α-Ga2O3 with low dislocation densities, which is desirable for developing ultralow-loss and ultrahigh power devices, whereas the involved dislocation dynamics have not been fully exploited. In this Letter, we investigated the dislocation propagations and reactions in α-Ga2O3 micropillar arrays selectively grown by halide vapor phase epitaxy technique. Screw dislocations in α-Ga2O3 micropillars grown from the selective area epitaxy (SAE) to ELO mode exhibited an independent character with an average density of 4.5 × 106 cm−2 while the edge dislocation density was reduced to 5.3 × 108 cm−2. During the initial SAE process, the α-Ga2O3 hexagonal pyramid is developed with the observed inversion domains within the pillar cores. The successive epitaxial lateral overgrowth ELO facilitates the formation of inclined facets upon the SiO2 mask. Almost complete filtering of the underlying threading dislocation has been demonstrated in the ELO wings. Strong image forces induced by inclined free surfaces drive the propagation and reaction of threading dislocations until annihilation, which is well described by the dislocation-filtering model during the dynamic geometry transition of micropillars. These findings may pave the way for the success of the heteroepitaxy of low dislocation density α-Ga2O3 toward the development of high-performance power devices.
Thermo-mechanical aspects of gamma irradiation effects on GaN HEMTs
Authors: Rasel Md Abu Jafar , Stepanoff Sergei P. , Wetherington Maxwell , Haque Aman , Wolfe Douglas E. , Ren Fan , Pearton Stephen
Published: March 2022

We report thermal and mechanical responses accompanying electrical characteristics of depletion mode GaN high electron mobility transistors exposed to gamma radiation up to 107 rads. Changes in the lattice strain and temperature were simultaneously characterized by changes in the phonon frequency of E2 (high) and A1 (LO) from the on-state and unpowered/pinched off reference states. Lower doses of radiation improved electrical properties; however, degradation initiated at about 106 rads. We observed about 16% decrease in the saturation current and 6% decrease in the transconductance at the highest dose. However, a leakage current increase by three orders of magnitude was the most notable radiation effect. We observed temperature increase by 40% and mechanical stress increase by a factor of three at a dose of 107 rads compared to the pristine devices. Spatial mapping of mechanical stress along the channel identifies the gate region as a mechanically affected area, whereas the thermal degradation was mostly uniform. Transmission electron microscopy showed contrast changes reflecting a high vacancy concentration in the gate region. These findings suggest that localized stress (mechanical hotspots) may increase vulnerability to radiation damage by accommodating higher concentration of defects that promote the leakage current.
Spintronic terahertz emitters exploiting uniaxial magnetic anisotropy for field-free emission and polarization control
Authors: Hewett S. M. , Bull C. , Shorrock A. M. , Lin C.-H. , Ji R. , Hibberd M. T. , Thomson T. , Nutter P. W. , Graham D. M.
Published: March 2022

We explore the terahertz (THz) emission from CoFeB/Pt spintronic structures in the below-magnetic-saturation regime and reveal an orientation dependence in the emission, arising from in-plane uniaxial magnetic anisotropy (UMA) in the ferromagnetic layer. Maximizing the UMA during the film deposition process and aligning the applied magnetic field with the easy axis of the structure allow the THz emission to reach saturation under weaker applied fields. In addition, the THz emission amplitude remains at saturation levels when the applied field is removed. The development of CoFeB/Pt spintronic structures that can emit broadband THz pulses without the need for an applied magnetic field is beneficial to THz magneto-optical spectroscopy and facilitates the production of large-area spintronic emitters. Furthermore, by aligning the applied field along the hard axis of the structure, the linear polarization plane of the emitted THz radiation can be manipulated by changing the magnitude of the applied field. We, therefore, demonstrate THz polarization control without the need for mechanical rotation of external magnets.
Normal modes description of nonlinear ferromagnetic resonance for magnetic nanodots
Authors: Perna S. , Bruckner F. , Serpico C. , Suess D. , d’Aquino M.
Published: March 2022

The spatially-inhomogeneous magnetization dynamics in a cylindrical magnetic nanodot driven by ac spin-torque is analyzed. To this end, the Landau-Lifshitz-Gilbert-Slonczewski equation is reformulated as a system of coupled nonlinear ordinary differential equations which describe the time-evolution of normal modes amplitudes. This approach provides a class of models with reduced number of degrees of freedom and incremental accuracy between macrospin and full micromagnetics. By using this approach, the onset of foldover effect for fundamental and higher-order modes is demonstrated. The results are confirmed by full micromagnetic simulations.
Production and performance of commercial beef breeding females in northern Australia. 4. Factors influencing the occurrence of lactating cows becoming pregnant within 4 months of calving
Authors: McCosker K. D. , Perkins N. R. , Fordyce G. , O’Rourke P. K. , McGowan M. R.
Published: March 2022

Context Sound reproductive efficiency is a key determinant for the overall productivity of a beef breeding business. For beef breeding herds to obtain high levels of reproductive productivity, breeding females need to efficiently become pregnant while lactating. Aims This study aimed to determine and quantify the major factors associated with lactating cows becoming pregnant within 4 months of calving (P4M) in commercial beef breeding herds of northern Australia. Methods A prospective epidemiological study was conducted using 78 commercial northern Australian beef breeding herds and involved 78 000 cattle that were monitored for 3–4 years. A multivariable model-building process was employed to scrutinise the resulting dataset to identify what herd-management practices, and nutritional, environmental and individual cow factors were major determinants of lactating cows becoming pregnant within 4 months of calving (P4M) and to estimate their magnitudes of effect. Key results Overall, 41.6% of cows per production year were successful for P4M. Country type was strongly associated with 65.4%, 57.5%, 61.8% and 16.4% P4M for the Southern Forest, Central Forest, Northern Downs, and Northern Forest respectively. Between-year variability ranged between 3.3 and 11.7 percentage points. Cows calving in December–January (61%) had a substantially higher occurrence of P4M than did cows calving between July and September (15%). The difference in P4M when comparing availability of wet-season pasture protein and phosphorus was 12.7 and 20.3 percentage points respectively. Modelling of the impact of group seroprevalence and management group prevalence of recent infection with several infectious diseases was estimated, with a large negative association between group bovine viral diarrhoea seroprevalence and P4M suggested. Conclusions This study further demonstrated the substantial impact that environment, herd management practices, nutrition and disease factors can have on the reproductive performance of females. Implications To optimise the performance of females (through increasing the occurrence of cows contributing calves in consecutive years) under commercial conditions in northern Australia, herd managers should focus on maximising the proportion of cows within a herd calving at the desired time of the year, ensuring that any nutritional deficiencies and herd health issues are managed, and that cows are managed such that they are of good body condition score at the time of calving.
Evolutionary dynamics, evolutionary forces, and robustness: A nonequilibrium statistical mechanics perspective
Authors: Rao Riccardo , Leibler Stanislas
Published: March 2022

Significance

Evolution through natural selection is an overwhelmingly complex process, and it is not surprising that theoretical approaches are strongly simplifying it. For instance, population genetics considers mainly dynamics of gene allele frequencies. Here, we develop a complementary approach to evolutionary dynamics based on three elements—organism reproduction, variations, and selection—that are essential for any evolutionary theory. By considering such general dynamics as a stochastic thermodynamic process, we clarify the nature and action of the evolutionary forces. We show that some of the forces cannot be described solely in terms of fitness landscapes. We also find that one force contribution can make organism reproduction insensitive (robust) to variations.
Behavioral responses to predatory sounds predict sensitivity of cetaceans to anthropogenic noise within a soundscape of fear
Authors: Miller Patrick J. O. , Isojunno Saana , Siegal Eilidh , Lam Frans-Peter A. , Kvadsheim Petter H. , Curé Charlotte
Published: March 2022

Significance

Acoustic signals travel efficiently in the marine environment, allowing soniferous predators and prey to eavesdrop on each other. Our results with four cetacean species indicate that they use acoustic information to assess predation risk and have evolved mechanisms to reduce predation risk by ceasing foraging. Species that more readily gave up foraging in response to predatory sounds of killer whales also decreased foraging more during 1- to 4-kHz sonar exposures, indicating that species exhibiting costly antipredator responses also have stronger behavioral reactions to anthropogenic noise. This advance in our understanding of the drivers of disturbance helps us to predict what species and habitats are likely to be most severely impacted by underwater noise pollution in oceans undergoing increasing anthropogenic activities.
Enhancement of speech-in-noise comprehension through vibrotactile stimulation at the syllabic rate
Authors: Guilleminot Pierre , Reichenbach Tobias
Published: March 2022

Significance

Syllables are important building blocks of speech. They occur at a rate between 4 and 8 Hz, corresponding to the theta frequency range of neural activity in the cerebral cortex. When listening to speech, the theta activity becomes aligned to the syllabic rhythm, presumably aiding in parsing a speech signal into distinct syllables. However, this neural activity cannot only be influenced by sound, but also by somatosensory information. Here, we show that the presentation of vibrotactile signals at the syllabic rate can enhance the comprehension of speech in background noise. We further provide evidence that this multisensory enhancement of speech comprehension reflects the multisensory integration of auditory and tactile information in the auditory cortex.
Lipoproteome screening of the Lyme disease agent identifies inhibitors of antibody-mediated complement killing
Authors: Pereira Michael J. , Wager Beau , Garrigues Ryan J. , Gerlach Eva , Quinn Joshua D. , Dowdell Alexander S. , Osburne Marcia S. , Zückert Wolfram R. , Kraiczy Peter , Garcia Brandon L. , Leong John M.
Published: March 2022

Significance

Spirochetal pathogens encode an abundance of lipoproteins that can provide a critical interface with the host environment.
Borrelia burgdorferi
, the model species for spirochetal biology, must survive an enzootic life cycle defined by fluctuations between vector (tick) and vertebrate host. While
B. burgdorferi
expresses over 80 surface lipoproteins—many of which likely contribute to host survival—the
B. burgdorferi
lipoproteome is poorly characterized. Here, we generated a platform to rapidly identify targets of
B. burgdorferi
surface lipoproteins and identified two paralogs that confer resistance to antibody-initiated complement killing that may promote survival in immunocompetent hosts. This work expands our understanding of complement evasion mechanisms and points toward a discovery approach for identifying host–pathogen interactions central to spirochete pathogenesis.
Spherical nucleic acids as an infectious disease vaccine platform
Authors: Teplensky Michelle H. , Distler Max E. , Kusmierz Caroline D. , Evangelopoulos Michael , Gula Haley , Elli Derek , Tomatsidou Anastasia , Nicolaescu Vlad , Gelarden Ian , Yeldandi Anjana , Batlle Daniel , Missiakas Dominique , Mirkin Chad A.
Published: March 2022

Significance

Using SARS-CoV-2 as a relevant case study for infectious disease, we investigate the structure–function relationships that dictate antiviral spherical nucleic acid (SNA) vaccine efficacy. We show that the SNA architecture can be rapidly employed to target COVID-19 through incorporation of the receptor-binding domain, and that the resulting vaccine potently activates human cells in vitro and mice in vivo. Furthermore, when challenged with a lethal viral infection, only mice treated with the SNA vaccine survived. Taken together, this work underscores the importance of rational vaccine design for infectious disease to yield vaccines that elicit more potent immune responses to effectively fight disease.
Massive perturbations to atmospheric sulfur in the aftermath of the Chicxulub impact
Authors: Junium Christopher K. , Zerkle Aubrey L. , Witts James D. , Ivany Linda C. , Yancey Thomas E. , Liu Chengjie , Claire Mark W.
Published: March 2022

Significance

Sulfur isotopes confirm a key role for atmospheric sulfur gases in climatic cooling, mass extinction, and the demise of dinosaurs and other global biota after the Chicxulub bolide impact at the Cretaceous–Paleogene boundary. The sulfur isotope anomalies are confined to beds containing ejecta and, in the immediately overlying sediments, are temporally unrelated to known episodes of volcanism that also bracket this event, further addressing the controversial role of the Deccan Traps in the extinction.
Functional enzyme–polymer complexes
Authors: Waltmann Curt , Mills Carolyn E. , Wang Jeremy , Qiao Baofu , Torkelson John M. , Tullman-Ercek Danielle , Olvera de la Cruz Monica
Published: March 2022

Significance

The use of biological enzyme catalysts could have huge ramifications for chemical industries. However, these enzymes are often inactive in nonbiological conditions, such as high temperatures, present in industrial settings. Here, we show that the enzyme PETase (polyethylene terephthalate [PET]), with potential application in plastic recycling, is stabilized at elevated temperature through complexation with random copolymers. We demonstrate this through simulations and experiments on different types of substrates. Our simulations also provide strategies for designing more enzymatically active complexes by altering polymer composition and enzyme charge distribution.
A completely precious metal–free alkaline fuel cell with enhanced performance using a carbon-coated nickel anode
Authors: Gao Yunfei , Yang Yao , Schimmenti Roberto , Murray Ellen , Peng Hanqing , Wang Yingming , Ge Chuangxin , Jiang Wenyong , Wang Gongwei , DiSalvo Francis J. , Muller David A. , Mavrikakis Manos , Xiao Li , Abruña Héctor D. , Zhuang Lin
Published: March 2022

Significance

We present a groundbreaking advance in completely nonprecious hydrogen fuel cell technologies achieving a record power density of 200 mW/cm
2
with Ni@CN
x
anode and Co−Mn cathode. The 2-nm CN
x
coating weakens the O-binding energy, which effectively mitigates the undesirable surface oxidation during hydrogen oxidation reaction (HOR) polarization, leading to a stable fuel cell operation for Ni@CN
x
over 100 h at 200 mA/cm
2
, superior to a Ni nanoparticle counterpart. Ni@CNx exhibited a dramatically enhanced tolerance to CO relative to Pt/C, enabling the use of hydrogen gas with trace amounts of CO, critical for practical applications. The complete removal of precious metals in fuel cells lowers the catalyst cost to virtually negligible levels and marks a milestone for practical alkaline fuel cells.
Biochemical and structural characterization of an aromatic ring–hydroxylating dioxygenase for terephthalic acid catabolism
Authors: Kincannon William M. , Zahn Michael , Clare Rita , Lusty Beech Jessica , Romberg Ari , Larson James , Bothner Brian , Beckham Gregg T. , McGeehan John E. , DuBois Jennifer L.
Published: March 2022

Significance

More than 400 million tons of plastic waste is produced each year, the overwhelming majority of which ends up in landfills. Bioconversion strategies aimed at plastics have emerged as important components of enabling a circular economy for synthetic plastics, especially those that exhibit chemically similar linkages to those found in nature, such as polyesters. The enzyme system described in this work is essential for mineralization of the xenobiotic components of poly(ethylene terephthalate) (PET) in the biosphere. Our description of its structure and substrate preferences lays the groundwork for in vivo or ex vivo engineering of this system for PET upcycling.
Characterisation of Sn–3.5Ag solder/Cu joint under various reflow conditions
Authors: Georgy K. , Tikale Sanjay , Prabhu K. Narayan
Published: March 2022

The effect of reflow time and reflow temperatures on wettability and bond shear strength of Sn–3.5Ag solder alloy on a Cu substrate is assessed for reflow times of 10 s, 100 s, 300 s, 500 s and reflow temperatures of 250 °C, 270 °C, 290 °C, 320 °C. The wetting regime was found to have capillary, gravity, and viscous regimes. A microstructural study using a scanning electron microscope (SEM) with energydispersive spectroscopy revealed the presence of intermetallic compounds at the interface between the substrate and solder droplet. The bond strength of the solder joint is maximum at a reflow temperature of 250  °C and a reflow time of 10 s. Bond shear strength decreased with an increase in reflow time from 10 s to 500 s. The effect of different cooling conditions on the solder–substrate joint is also investigated.
The Cu/Fe magnetic yoke with novel interface and excellent mechanical properties by friction stir welding
Authors: Zhou Mengran , Chen Gaoqiang , Wu Jianjun , Liu Qu , Lei Bingwang , Gao Yunxi , Liu Yijun , Zhang Shuai , Shi Qingyu
Published: March 2022

A novel Fe/Cu interface with excellent mechanical properties in a magnetic yoke was fabricated by friction stir welding. This method eliminated defects that commonly form during conventional bead welding. The thick oxidisation layer at the Cu/Fe surface that formed due to fusion welding was eliminated during friction stir welding (FSW). Combined with the severe deformation introduced by FSW, the Cu/Fe interface obtained by fusion welding was hardly distinguishable due to mutual embedding at the Cu/Fe interface. The in situ digital image correlation analysis indicated that this Cu/Fe interface reconstruction also modified the deformation and crack propagation behaviours. The tensile load and displacement of the joint by FSW were remarkably improved while maintaining magnetic isolation.
Integrable nonlocal derivative nonlinear Schrödinger equations
Authors: Ablowitz Mark J , Luo Xu-Dan , Musslimani Ziad H , Zhu Yi
Published: March 2022

Integrable standard and nonlocal derivative nonlinear Schrödinger equations are investigated. The direct and inverse scattering are constructed for these equations; included are both the Riemann–Hilbert and Gel’fand–Levitan–Marchenko approaches and soliton solutions. As a typical application, it is shown how these derivative NLS equations can be obtained as asymptotic limits from a nonlinear Klein–Gordon equation.
Adaptively sketched Bregman projection methods for linear systems
Authors: Yuan Zi-Yang , Zhang Lu , Wang Hongxia , Zhang Hui
Published: March 2022

The sketch-and-project, as a general archetypal algorithm for solving linear systems, unifies a variety of randomized iterative methods such as the randomized Kaczmarz and randomized coordinate descent. However, since it aims to find a least-norm solution from a linear system, the randomized sparse Kaczmarz can not be included. This motivates us to propose a more general framework, called sketched Bregman projection (SBP) method, in which we are able to find solutions with certain structures from linear systems. To generalize the concept of adaptive sampling to the SBP method, we show how the progress, measured by Bregman distance, of single step depends directly on a sketched loss function. Theoretically, we provide detailed global convergence results for the SBP method with different adaptive sampling rules. At last, for the (sparse) Kaczmarz methods, a group of numerical simulations are tested, with which we verify that the methods utilizing sampling Kaczmarz–Motzkin rule demands the fewest computational costs to achieve a given error bound comparing to the corresponding methods with other sampling rules.
Maximum reweighted-kurtosis deconvolution: a fully blind and adaptive method for restoration of gear fault impulse trains
Authors: Wu Lei , Wang Jiaxu , Zhang Xin , Liu Zhiwen
Published: March 2022

Deconvolution based on vibration signals has been proven to be an effective tool in gear fault diagnosis. However, for many common methods, precisely restoring the fault impulse train is still a challenging task due to the great dependence on prior knowledge and the empirical determination of filter parameters. In this paper, a fully blind and adaptive method termed maximum reweighted-kurtosis deconvolution (MRKD) is proposed. A new deconvolution criterion, i.e., reweighted-kurtosis, is defined. This criterion possesses great robustness to impulse interferencesand thus has great potential to solve the problem of previous kurtosis-based methods in which a single dominant impulse is deconvolved instead of the impulse train induced by a localized fault. Furthermore, a parameter-adaptive strategy is developed to adaptively determine the appropriate filter parameters. As such, the proposed method does not require any prior knowledge of the target fault impulse train and addresses the critical issue of many common methods specifying filter parameters empirically. The proposed method is validated through simulated and real vibration signals. Comparison with the most popular deconvolution methods indicates that MRKD outperforms other methods for the restoration of a gear fault impulse train.
Constructing van der Waals heterostructures by dry-transfer assembly for novel optoelectronic device
Authors: Li Huihan , Xiong Xiaolu , Hui Fei , Yang Dongliang , Jiang Jinbao , Feng Wanxiang , Han Junfeng , Duan Junxi , Wang Zhongrui , Sun Linfeng
Published: March 2022

Since the first successful exfoliation of graphene, the superior physical and chemical properties of two-dimensional (2D) materials, such as atomic thickness, strong in-plane bonding energy and weak inter-layer van der Waals (vdW) force have attracted wide attention. Meanwhile, there is a surge of interest in novel physics which is absent in bulk materials. Thus, vertical stacking of 2D materials could be critical to discover such physics and develop novel optoelectronic applications. Although vdW heterostructures have been grown by chemical vapor deposition, the available choices of materials for stacking is limited and the device yield is yet to be improved. Another approach to build vdW heterostructure relies on wet/dry transfer techniques like stacking Lego bricks. Although previous reviews have surveyed various wet transfer techniques, novel dry transfer techniques have been recently been demonstrated, featuring clean and sharp interfaces, which also gets rid of contamination, wrinkles, bubbles formed during wet transfer. This review summarizes the optimized dry transfer methods, which paves the way towards high-quality 2D material heterostructures with optimized interfaces. Such transfer techniques also lead to new physical phenomena while enable novel optoelectronic applications on artificial vdW heterostructures, which are discussed in the last part of this review.
Design of polysaccharidic Aloe vera gel incorporated PVA/tetracycline electrospun cell culture scaffolds for biomedical applications
Authors: Allafchian Alireza , Fathi Mohammad , Jalali Seyed Amir Hossein
Published: March 2022

In this study, hybrid nanofibrous 3D scaffolds containing Aloe vera (AV), polyvinyl alcohol (PVA) and tetracycline hydrochloride (TCH) are fabricated by electrospinning for cell culture applications. The role of polysaccharides present in AV gel is found to enhance the biocompatibility of the nanofibrous scaffolds. Different combinations of the polymers were selected to produce homogenous nanofibers with favorable mean fiber diameter and tensile strength. The surface morphology of the products was studied by SEM and it is found that the mean fiber diameter is decreased to about 188 nm upon addition of the AV component. The electrospun scaffolds were investigated by FT-IR spectroscopy to reveal the chemical structure of the samples and their crystallinity was studied by XRD. The hydrophilicity of the scaffolds was tested by optical contact angle measurements and their mechanical strength was examined by tensile strength tests. It is found that PVA is the main component contributing the mechanical stability of the scaffold structure. The fabricated scaffolds presented a more pronounced inhibitory effect against Gram-positive bacterial strains of S. aureus and B. cereus. Cell culture experiments using fibroblast L929 murine cells reveals that the AV/PVA/TCH scaffolds are promising for cell growth and the cells are capable of achieving a proper cell adhesion and proliferation. The cell viability experiment by MTT assay exhibits the contributing role of AV gel to L929 cell viability on the AV/PVA/TCH scaffolds.
Cooperative effect of bimetallic MOF-derived CoNi(OH)2@NiCo2S4 nanocomposite electrocatalysts with boosted oxygen evolution activity
Authors: Zheng Lingxia , Wang Shibin , Wang Yongzhi , Zhao Zhefei , Yang Pengju , Song Jianlan , Shi Xiaowei , Zheng Huajun
Published: March 2022

Highly efficient and inexpensive electrocatalysts for oxygen evolution reaction (OER) are extensively studied for water splitting. Herein, a unique bimetallic nanocomposite CoNi(OH)2@NiCo2S4 nanosheet arrays derived from metal-organic-frameworks (MOFs, CoNi-ZIF) is simply fabricated on Ni foam, endowing large specific surface area and outstanding electrical conductivity. Compared with their single-metallic counterparts, the bimetallic composite displays dramatically low overpotential and small Tafel slope as well as outstanding catalytic stability. The overpoptential at 20 mA cm−2 for CoNi(OH)2@NiCo2S4 is only 230 mV in comparison with Ni(OH)2@Ni3S2 (266 mV), Co(OH)2@Co3S4 (294 mV) and RuO2 (η = 302 mV). First-principle calculations based on density functional theory (DFT) are carried out and reveal that the introduction of Ni in Co(OH)2 helps lowered the energy difference of ΔG
OOH*–ΔG
O*, and thereby boosting the OER reactivity. This study provides an effective approach for the rational construction of low-cost metal hybrids.
Patient-specific deep learning model to enhance 4D-CBCT image for radiomics analysis
Authors: Zhang Zeyu , Huang Mi , Jiang Zhuoran , Chang Yushi , Lu Ke , Yin Fang-Fang , Tran Phuoc , Wu Dapeng , Beltran Chris , Ren Lei
Published: March 2022

Objective. 4D-CBCT provides phase-resolved images valuable for radiomics analysis for outcome prediction throughout treatment courses. However, 4D-CBCT suffers from streak artifacts caused by under-sampling, which severely degrades the accuracy of radiomic features. Previously we developed group-patient-trained deep learning methods to enhance the 4D-CBCT quality for radiomics analysis, which was not optimized for individual patients. In this study, a patient-specific model was developed to further improve the accuracy of 4D-CBCT based radiomics analysis for individual patients. Approach. This patient-specific model was trained with intra-patient data. Specifically, patient planning 4D-CT was augmented through image translation, rotation, and deformation to generate 305 CT volumes from 10 volumes to simulate possible patient positions during the onboard image acquisition. 72 projections were simulated from 4D-CT for each phase and were used to reconstruct 4D-CBCT using FDK back-projection algorithm. The patient-specific model was trained using these 305 paired sets of patient-specific 4D-CT and 4D-CBCT data to enhance the 4D-CBCT image to match with 4D-CT images as ground truth. For model testing, 4D-CBCT were simulated from a separate set of 4D-CT scan images acquired from the same patient and were then enhanced by this patient-specific model. Radiomics features were then extracted from the testing 4D-CT, 4D-CBCT, and enhanced 4D-CBCT image sets for comparison. The patient-specific model was tested using 4 lung-SBRT patients’ data and compared with the performance of the group-based model. The impact of model dimensionality, region of interest (ROI) selection, and loss function on the model accuracy was also investigated. Main results. Compared with a group-based model, the patient-specific training model further improved the accuracy of radiomic features, especially for features with large errors in the group-based model. For example, the 3D whole-body and ROI loss-based patient-specific model reduces the errors of the first-order median feature by 83.67%, the wavelet LLL feature maximum by 91.98%, and the wavelet HLL skewness feature by 15.0% on average for the four patients tested. In addition, the patient-specific models with different dimensionality (2D versus 3D) or loss functions (L1 versus L1 + VGG + GAN) achieved comparable results for improving the radiomics accuracy. Using whole-body or whole-body+ROI L1 loss for the model achieved better results than using the ROI L1 loss alone as the loss function. Significance. This study demonstrated that the patient-specific model is more effective than the group-based model on improving the accuracy of the 4D-CBCT radiomic features analysis, which could potentially improve the precision for outcome prediction in radiotherapy.
Boosting transducer matrix sensitivity for 3D large field ultrasound localization microscopy using a multi-lens diffracting layer: a simulation study
Authors: Favre Hugues , Pernot Mathieu , Tanter Mickael , Papadacci Clément
Published: March 2022

Mapping blood microflows of the whole brain is crucial for early diagnosis of cerebral diseases. Ultrasound localization microscopy (ULM) was recently applied to map and quantify blood microflows in 2D in the brain of adult patients down to the micron scale. Whole brain 3D clinical ULM remains challenging due to the transcranial energy loss which significantly reduces the imaging sensitivity. Large aperture probes with a large surface can increase both resolution and sensitivity. However, a large active surface implies thousands of acoustic elements, with limited clinical translation. In this study, we investigate via simulations a new high-sensitive 3D imaging approach based on large diverging elements, combined with an adapted beamforming with corrected delay laws, to increase sensitivity. First, pressure fields from single elements with different sizes and shapes were simulated. High directivity was measured for curved element while maintaining high transmit pressure. Matrix arrays of 256 elements with a dimension of 10 × 10 cm with small (λ/2), large (4λ), and curved elements (4λ) were compared through point spread functions analysis. A large synthetic microvessel phantom filled with 100 microbubbles per frame was imaged using the matrix arrays in a transcranial configuration. 93% of the bubbles were detected with the proposed approach demonstrating that the multi-lens diffracting layer has a strong potential to enable 3D ULM over a large field of view through the bones.
Impact of acquisition time and misregistration with CT on data-driven gated PET
Authors: Thomas M Allan , Meier Joseph G , Mawlawi Osama R , Sun Peng , Pan Tinsu
Published: March 2022

Objective. Data-driven gating (DDG) can address patient motion issues and enhance PET quantification but suffers from increased image noise from utilization of <100% of PET data. Misregistration between DDG-PET and CT may also occur, altering the potential benefits of gating. Here, the effects of PET acquisition time and CT misregistration were assessed with a combined DDG-PET/DDG-CT technique. Approach. In the primary PET bed with lesions of interest and likely respiratory motion effects, PET acquisition time was extended to 12 min and a low-dose cine CT was acquired to enable DDG-CT. Retrospective reconstructions were created for both non-gated (NG) and DDG-PET using 30 s to 12 min of PET data. Both the standard helical CT and DDG-CT were used for attenuation correction of DDG-PET data. SUVmax, SUVpeak, and CNR were compared for 45 lesions in the liver and lung from 27 cases. Main results. For both NG-PET (p = 0.0041) and DDG-PET (p = 0.0028), only the 30 s acquisition time showed clear SUVmax bias relative to the 3 min clinical standard. SUVpeak showed no bias at any change in acquisition time. DDG-PET alone increased SUVmax by 15 ± 20% (p < 0.0001), then was increased further by an additional 15 ± 29% (p = 0.0007) with DDG-PET/CT. Both 3 min and 6 min DDG-PET had lesion CNR statistically equivalent to 3 min NG-PET, but then increased at 12 min by 28 ± 48% (p = 0.0022). DDG-PET/CT at 6 min had comparable counts to 3 min NG-PET, but significantly increased CNR by 39 ± 46% (p < 0.0001). Significance. 50% counts DDG-PET did not lead to inaccurate or biased SUV—increased SUV resulted from gating. Improved registration from DDG-CT was equally as important as motion correction with DDG-PET for increasing SUV in DDG-PET/CT. Lesion detectability could be significantly improved when DDG-PET used equivalent counts to NG-PET, but only when combined with DDG-CT in DDG-PET/CT.
Foundations of plasma catalysis for environmental applications
Authors: Bogaerts Annemie , Neyts Erik C , Guaitella Olivier , Murphy Anthony B
Published: March 2022

Plasma catalysis is gaining increasing interest for various applications, but the underlying mechanisms are still far from understood. Hence, more fundamental research is needed to understand these mechanisms. This can be obtained by both modelling and experiments. This foundations paper describes the fundamental insights in plasma catalysis, as well as efforts to gain more insights by modelling and experiments. Furthermore, it discusses the state-of-the-art of the major plasma catalysis applications, as well as successes and challenges of technology transfer of these applications.
Searches for light dark matter using condensed matter systems
Authors: Kahn Yonatan , Lin Tongyan
Published: March 2022

Identifying the nature of dark matter (DM) has long been a pressing question for particle physics. In the face of ever-more-powerful exclusions and null results from large-exposure searches for TeV-scale DM interacting with nuclei, a significant amount of attention has shifted to lighter (sub-GeV) DM candidates. Direct detection of the light DM in our galaxy by observing DM scattering off a target system requires new approaches compared to prior searches. Lighter DM particles have less available kinetic energy, and achieving a kinematic match between DM and the target mandates the proper treatment of collective excitations in condensed matter systems, such as charged quasiparticles or phonons. In this context, the condensed matter physics of the target material is crucial, necessitating an interdisciplinary approach. In this review, we provide a self-contained introduction to direct detection of keV–GeV DM with condensed matter systems. We give a brief survey of DM models and basics of condensed matter, while the bulk of the review deals with the theoretical treatment of DM-nucleon and DM-electron interactions. We also review recent experimental developments in detector technology, and conclude with an outlook for the field of sub-GeV DM detection over the next decade.
A fast approach to measuring the thickness uniformity of a homoepilayer grown on to any type of silicon wafer
Authors: Myronov Maksym , Colston Gerard , Davies Jack , Michael Laura
Published: March 2022

Optical reflection spectroscopy techniques offer a non-destructive and fast method of measuring the thickness of silicon (Si) epilayers, enabling very fast thickness uniformity mapping across the full surface of epiwafers up to 450 mm in diameter. However, their use for undoped or low doped epilayers has traditionally been constrained by a dependence on high levels of substitutional doping in the Si wafer, at values of approximately 5 × 1019 cm−3. Whilst the high dopant concentration of this wafer creates the necessary reflectance boundary for optical reflection, their commercial availability is mainly limited to the (001) surface orientation only. Optical reflectance techniques are therefore also limited in use to this orientation. In this article, an approach to measure the thickness of a Si epilayer on any Si wafer, independent of its crystallographic orientation, doping type and value, using Fourier transform infrared reflection spectroscopy is proposed and demonstrated. Because the use of non-destructive optical reflection spectroscopy is already common and well-understood within both industry and academia, this technique could easily be implemented within existing industrial and research fabrication facilities. Furthermore, this approach could be adapted, with further work, to suit other semiconductor materials and other optical reflection techniques.
An optical elevator for precise delivery of cold atoms using an acousto-optical deflector
Authors: Ferri Francesco , La Rooij Arthur , Lebouteiller Claire , Bourdel Pierre-Antoine , Baghdad Mohamed , Schwartz Sylvain , Garcia Sébastien , Reichel Jakob , Long Romain
Published: March 2022

We implement a simple method for fast and precise delivery of ultracold atoms to a microscopic device, i.e. a Fabry–Perot microcavity. By moving a single beam optical dipole trap in a direction perpendicular to the beam axis with an acousto-optical deflector, we transport up to 1 million atoms within 100 ms over 1 cm. Under these conditions, a transport efficiency above 95% is achieved with only minimal heating. The atomic cloud is accurately positioned within the microcavity and transferred into an intra-cavity optical lattice. With the addition of a secondary guiding beam, we show how residual sloshing motion along the shallow axis of the trap can be minimized.
Percolation behaviors of finite components on complex networks
Authors: Wang Fan , Dong Gaogao , Tian Lixin , Stanley H Eugene
Published: March 2022

Percolation behavior is of wide applicability and provides insight into functional structure of complex networks. Different from the percolation behaviors of giant component (GC), the finite components make one more clearly explore network percolation behaviors and critical phenomena from a microscopic perspective, especially for large-scale network systems. Here we focus on the percolation behaviors of small component π

s
with the size s = 1, 2, 3, … under different failure scenarios such as random attack, localized attack, target attack and intentional attack with limited knowledge. We find theoretically and via simulation that finite components all show the peak shape which is different from GC for random networks including random regular network, Erdős–R

e

´

nyi networks and scale-free networks. In particular, we find a new general scaling relationship between

1

s

and

1

p

max

, p
max represents the value of p (non-failure fraction of initial nodes) corresponding to the peak point of π

s
in the network. This finding also provides a potential approach for determining the critical threshold and fill the gap between finite components and GC on the percolation process.
Universal topological quantum computation with strongly correlated Majorana edge modes
Authors: Zhan Ye-Min , Chen Yu-Ge , Chen Bin , Wang Ziqiang , Yu Yue , Luo Xi
Published: March 2022

Majorana-based quantum gates are not complete for performing universal topological quantum computation while Fibonacci-based gates are difficult to be realized electronically and hardly coincide with the conventional quantum circuit models. In reference Hu and Kane (2018 Phys. Rev. Lett.
120 066801), it has been shown that a strongly correlated Majorana edge mode in a chiral topological superconductor can be decomposed into a Fibonacci anyon τ and a thermal operator anyon ɛ in the tricritical Ising model. The deconfinement of τ and ɛ via the interaction between the fermion modes yields the anyon collisions and gives the braiding of either τ or ɛ. With these braidings, the complete members of a set of universal gates, the Pauli gates, the Hadamard gate and extra phase gates for one-qubit as well as controlled-NOT (CNOT) gate for two-qubits, are topologically assembled. Encoding quantum information and reading out the computation results can be carried out through electric signals. With the sparse-dense mixed encodings, we set up the quantum circuit where the CNOT gate turns out to be a probabilistic gate and design the corresponding devices with thin films of the chiral topological superconductor. As an example of the universal topological quantum computing, we show the application to Shor’s integer factorization algorithm.
Including relativistic and primordial non-Gaussianity contributions in cosmological simulations by modifying the initial conditions
Authors: Enríquez Miguel , Hidalgo Juan Carlos , Valenzuela Octavio
Published: March 2022

We present a method to implement relativistic corrections
to the evolution of dark matter structures in Newtonian simulations
of a ΛCDM universe via the initial conditions. We take the
nonlinear correspondence between the Lagrangian (Newtonian)
evolution of dark matter inhomogeneities and the
synchronous-comoving (relativistic) matter density description, and
use it to promote the relativistic constraint as the initial
condition for numerical simulations of structure formation. In this
case, the incorporation of Primordial non-Gaussianity (PNG)
contributions as initial conditions is straightforward. We implement
the relativistic, f
NL and g
NL contributions as
initial conditions for the L-PICOLA code, and compute the power
spectrum and bispectrum of the evolved matter field. We focus
specifically on the case of largest values of non-Gaussianity
allowed at 1-σ by Planck observations (f
NL = −4.2
and g
NL = −7000). As a checkup, we show consistency with
the one-loop perturbative prescription and with a fully relativistic
simulation (GRAMSES) on the adequate scales. Our results
confirm that both relativistic and PNG features are most prominent
at very large scales and for squeezed triangulations. We discuss
future prospects to probe these two contributions in the bispectrum
of the matter density distribution.
Non-spherical dark matter structures detection
Authors: Loizeau Nicolas , Farrar Glennys R.
Published: March 2022

A rotation curve inequality that holds for spherically symmetric mass distributions is derived, and tested against the SPARC galaxy rotation curves dataset. We identify several Galaxies, e.g. NGC7793 and UGC11557, which are candidates for hosting non-spherical dark matter structures that could be detected by more precise measurements.
Spectroscopic properties and laser emission of Yb0.05Y0.20La0.12Gd0.63Ca4O(BO3)3 mixed oxyborate crystal
Authors: Han Wenjuan , Dong Liang , Zhou Youshi , Zhang Yuxia , Xu Honghao , Liu Junhai
Published: March 2022

Polarized absorption and emission cross-sections at 850–1100 nm are determined for an Yb-doped La-containing mixed oxyborate crystal of Yb0.05Y0.20La0.12Gd0.63Ca4O(BO3)3. The strongest absorption occurs at 976.8 nm for E//Y, with a cross-section of 1.83 × 10−20 cm2; for the main emission band the dominant polarization proves to be E//Z, for which the maximum cross-section amounts to 0.31 × 10−20 cm2 at 1025.8 nm. Efficient laser emission was generated with X- and Z-cut crystals in a compact plane-parallel resonator; 8.06 W of output power was obtained at 1056–1067 nm in the edge of the main emission band with an optical-to-optical efficiency of 70%; while for laser emission in the long-wavelength sideband, the output power attainable reached 9.19 W at 1080–1081 nm, the optical-to-optical and slope efficiencies being, respectively, 69% and 75%.
Effect of nucleotides and turmeric extract on blood protein and body weight of broiler kept in open cages
Authors: Tugiyanti E , Susanti E , Ismoyowati I , Rosidi R
Published: March 2022

Indonesia’s wet tropical climate is a condition that does not support the development chickens. Therefore, this study aims to analyze the effect of nucleotides and turmeric extract in basal feed on broilers’ blood protein and body weight. Data was collected using a Completely Randomized Design (CRD) with 7 treatments that comprised of negative and positive control. Meanwhile, the negative aspects include basal feed + plus Zink Bactitracin 0.1 g, while the positive control consists of N0K1, N1K0, N1K1, N2K0, and N2K1. The results showed that nucleotide supplementation and turmeric extract in the feed had no significant effect on blood PCV, TPP, albumin levels, and broiler body weights. Furthermore, blood protein increases due to the high levels of nucleotides and turmeric extract. The 5 g of nucleotide supplementation and turmeric extract produce the same broilers blood protein and body weight.