bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlation lengths in nanoconfined water and transport properties
Authors: Kumar Shubham , Bagchi Biman
Published: May 2022

We report the existence of disparate static and dynamic correlation lengths that could describe the influence of confinement on nanoconfined water (NCW). Various aspects of viscous properties, such as anisotropy and viscoelasticity, of NCW are studied by varying the separation distance “d” between two confining hydrophobic plates. The transverse component of the mean square stress exhibits slow spatial decay (measured from the surface) beyond ∼1.8 nm, which was not reported before. The static correlation length obtained from fitting the exponential decay of the transverse mean-square stress with d is 0.75 nm, while the decay time of the stress–stress time correlation function gives a dynamic correlation length of only 0.35 nm. The shortness of the dynamic correlation length seems to arise from the low sensitivity of orientational relaxation to confinement. In the frequency-dependent viscosity, we observe a new peak at about 50 cm−1 that is not present in the bulk. This new peak is prominent even at 3 nm separations. The peak is absent in the bulk, although it is close to the intermolecular –O–O–O– bending mode well known in liquid water. We further explore the relationship between diffusion and viscosity in NCW by varying d.
Photoionization and core resonances from range-separated density-functional theory: General formalism and example of the beryllium atom
Authors: Schwinn Karno , Zapata Felipe , Levitt Antoine , Cancès Éric , Luppi Eleonora , Toulouse Julien
Published: May 2022

We explore the merits of linear-response range-separated time-dependent density-functional theory (TDDFT) for the calculation of photoionization spectra. We consider two variants of range-separated TDDFT, namely, the time-dependent range-separated hybrid (TDRSH) scheme, which uses a global range-separation parameter, and the time-dependent locally range-separated hybrid (TDLRSH), which uses a local range-separation parameter, and compare with standard time-dependent local-density approximation (TDLDA) and time-dependent Hartree–Fock (TDHF). We show how to calculate photoionization spectra with these methods using the Sternheimer approach formulated in a non-orthogonal B-spline basis set with appropriate frequency-dependent boundary conditions. We illustrate these methods on the photoionization spectrum of the Be atom, focusing, in particular, on the core resonances. Both the TDRSH and TDLRSH photoionization spectra are found to constitute a large improvement over the TDLDA photoionization spectrum and a more modest improvement over the TDHF photoionization spectrum.
Observational study on drag reduction of continental-shelf bottom boundary layer
Authors: Qian Suhui , Zhang Jicai , Wang Daosheng , Wang Ya Ping
Published: May 2022

Long-term and high-frequency observing of the oceanic bottom boundary layer was implemented using a seabed-mounted tripod equipped with multiple high-frequency instruments in a semidiurnal tide-dominated channel around the Zhoushan Islands, China. The estimated turbulent parameters, e.g., turbulent intensity, friction velocity, and bottom drag coefficient, varied with quarter-diurnal frequency. The amplitudes of turbulent intensity, bottom stress, and friction velocity were larger in spring tide than those in neap tide. As the Reynolds number increased from 103 to 105, the measured bottom drag coefficient initially increased, peaked at a Reynolds number of approximately 1.4 × 105, and then decreased. The observed drag reduction is similar to the variations of drag coefficient of cross-flow around a circular cylinder and the fluid friction of the pipe flow in the transitional state, which can provide a necessary and important proof for further theoretical and experimental investigations. Several plausible explanations are raised for this reduction: the stratification caused by the gradient of salinity or sediment suspension and the occurrence of recirculation vortices generated by seabed topography.
Fluorescent molecular rotor probes nanosecond viscosity changes
Authors: Caporaletti Federico , Bittermann Marius R. , Bonn Daniel , Woutersen Sander
Published: May 2022

Viscosity is a key property of liquids, but it is difficult to measure in short-lived, metastable samples due to the long measuring times required by conventional rheology. Here, we show how this problem can be solved by using fluorescent molecular rotors. The excited-state fluorescence decay rate of these molecules is sensitive to the viscosity of their local environment, and by combining pulsed laser excitation with time-resolved fluorescence detection, we can measure viscosities with a time resolution of a few ns. We demonstrate this by measuring in real time the viscosity change in glycerol induced by a nanosecond temperature jump. This new approach makes it possible to measure the viscosity of extremely short-lived states of matter.
A perspective on ab initio modeling of polaritonic chemistry: The role of non-equilibrium effects and quantum collectivity
Authors: Sidler Dominik , Ruggenthaler Michael , Schäfer Christian , Ronca Enrico , Rubio Angel
Published: May 2022

This Perspective provides a brief introduction into the theoretical complexity of polaritonic chemistry, which emerges from the hybrid nature of strongly coupled light–matter states. To tackle this complexity, the importance of ab initio methods is highlighted. Based on those, novel ideas and research avenues are developed with respect to quantum collectivity, as well as for resonance phenomena immanent in reaction rates under vibrational strong coupling. Indeed, fundamental theoretical questions arise about the mesoscopic scale of quantum-collectively coupled molecules when considering the depolarization shift in the interpretation of experimental data. Furthermore, to rationalize recent findings based on quantum electrodynamical density-functional theory (QEDFT), a simple, but computationally efficient, Langevin framework is proposed based on well-established methods from molecular dynamics. It suggests the emergence of cavity-induced non-equilibrium nuclear dynamics, where thermal (stochastic) resonance phenomena could emerge in the absence of external periodic driving. Overall, we believe that the latest ab initio results indeed suggest a paradigmatic shift for ground-state chemical reactions under vibrational strong coupling from the collective quantum interpretation toward a more local, (semi)-classically and non-equilibrium dominated perspective. Finally, various extensions toward a refined description of cavity-modified chemistry are introduced in the context of QEDFT, and future directions of the field are sketched.
Perspectives on an exhausted medical radiation practitioner workforce: emotional labour and the impact of compassion fatigue
Authors: Ku Min , Cavanagh Jillian , Bartram Timothy , Halvorsen Beni
Published: May 2022

As the COVID-19 pandemic in Australia reaches its peak, medical radiation practitioners (MRPs) are at capacity both physically and emotionally. High workloads and stress impact the mental wellbeing of MRPs, with suppression of feelings and emotions resulting in experiences of compassion fatigue. From a MRP workforce perspective, the long-term cost of the pandemic has yet to be realised. MRPs need to be supported to prevent unintended health consequences. Robust management interventions will be required to support the MRP workforce to manage and hopefully mitigate compassion fatigue transitioning out of the pandemic.
Fluorescent assay for carbendazim determination using aptamer and SYBR Green I
Authors: Shi Yuzheng , Xie Xicheng , Wang Lumei , Wang Linzheng , Li Lingyun , Yan Zhiyu , Shen Guoqing
Published: May 2022

This paper describes a fluorometric assay for the determination of carbendazim (CBZ) in aqueous samples based on an unmodified CBZ-specific aptamer and the fluorescent intercalator SYBR Green I (SG-I). The CBZ aptamer has double-stranded parts and G-quadruplex spatial structures, which can be recognized by SG-I. It leads to strong fluorescent emission of SG-I. In the presence of CBZ, the aptamer will bind to CBZ to form stable compounds due to its specific affinity. This will induce the conformational change of the aptamer. SG-I will then detach from the aptamer, leading to the decrease of its fluorescence. Therefore, the concentration of CBZ is determined through the changes in fluorescence of the system. This fluorometric biosensor for CBZ detection is constructed with a linear range from 3.58 to 230 nM with a limit of detection (LOD) of 3.58 nM. With great sensitivity and selectivity, this assay is efficient and convenient with a < 40 min operation time. Meanwhile, the average recovery of CBZ is 99.87–101.77% in the application of actual water samples with relative standard deviations (RSD) ranging from 1.97 to 2.63%.
Short daily ultraviolet exposure enhances intrinsic water-use efficiency and delays senescence in Micro-Tom tomato plants
Authors: Mannucci Alessia , Scartazza Andrea , Santaniello Antonietta , Castagna Antonella , Santin Marco , Quartacci Mike Frank , Ranieri Annamaria
Published: May 2022

Ultraviolet (UV) radiation, unless present at high doses, is recognised as a regulator of plant growth and some specific processes. The present study investigated the influence of short daily UV irradiation (15 min/day, 11 days) on leaf gas exchange and some biochemical and molecular markers of leaf senescence (such as stomata movements, chlorophyll breakdown, anthocyanin production, senescence-associated genes) in Micro-Tom tomato plants. The UV-induced reduction of gs (stomatal conductance) during the treatment was associated with the modified expression of some genes involved in the control of stomatal movements. We hypothesise a two-step regulation of stomatal closure involving salicylic and abscisic acid hormones. The temporal changes of gs and Anet (net photosynthetic CO2 assimilation rate) along with the pigment behaviour, suggest a possible delay of leaf senescence in treated plants, confirmed by the expression levels of genes related to senescence such as SAG113 and DFR. The UV potential to induce a persistent partial inhibition of gs without severely affecting Anet led to an increased iWUE (intrinsic water-use efficiency) during the 11-day treatment, suggesting a priming effect of short daily UV radiation towards drought conditions potentially useful in reducing the excess water use in agriculture.
Diffusion MRI–guided theta burst stimulation enhances memory and functional connectivity along the inferior longitudinal fasciculus in mild cognitive impairment
Authors: Chen Yu-Chin , Ton That Viet , Ugonna Chidi , Liu Yilin , Nadel Lynn , Chou Ying-hui
Published: May 2022

Significance

Noninvasive theta burst stimulation (TBS) guided by brain white matter tractography is a promising approach to strengthen resting-state functional connectivity of the hippocampus and increase associative memory performance in individuals with mild cognitive impairment. With this approach, our findings add insight into how TBS propagates from the superficial stimulation site to the hippocampus along the inferior longitudinal fasciculus. Results of this study provide an innovative platform for developing a noninvasive hippocampal stimulation protocol that has great potential in enhancing memory function in mild cognitive impairment.
A quantitative synthesis of soil microbial effects on plant species coexistence
Authors: Yan Xinyi , Levine Jonathan M. , Kandlikar Gaurav S.
Published: May 2022

Significance

Understanding the processes that maintain plant diversity is a key goal in ecology. Many previous studies have shown that soil microbes can generate stabilizing or destabilizing feedback loops that drive either plant species coexistence or monodominance. However, theory shows that microbial controls over plant coexistence also arise through microbially mediated competitive imbalances, which have been largely neglected. Using data from 50 studies, we found that soil microbes affect plant dynamics primarily by generating competitive fitness differences rather than stabilizing or destabilizing feedbacks. Consequently, in the absence of other competitive asymmetries among plants, soil microbes are predicted to drive species exclusion more than coexistence. These results underscore the need for measuring competitive fitness differences when evaluating microbial controls over plant coexistence.
Mitigating climate disruption in time: A self-consistent approach for avoiding both near-term and long-term global warming
Authors: Dreyfus Gabrielle B. , Xu Yangyang , Shindell Drew T. , Zaelke Durwood , Ramanathan Veerabhadran
Published: May 2022

Significance

This study clarifies the need for comprehensive CO
2
and non-CO
2
mitigation approaches to address both near-term and long-term warming. Non-CO
2
greenhouse gases (GHGs) are responsible for nearly half of all climate forcing from GHG. However, the importance of non-CO
2
pollutants, in particular short-lived climate pollutants, in climate mitigation has been underrepresented. When historical emissions are partitioned into fossil fuel (FF)- and non-FF-related sources, we find that nearly half of the positive forcing from FF and land-use change sources of CO
2
emissions has been masked by coemission of cooling aerosols. Pairing decarbonization with mitigation measures targeting non-CO
2
pollutants is essential for limiting not only the near-term (next 25 y) warming but also the 2100 warming below 2 °C.
Interfacial engineering of plasmonic nanoparticle metasurfaces
Authors: Deng Shikai , Park Jeong-Eun , Kang Gyeongwon , Guan Jun , Li Ran , Schatz George C. , Odom Teri W.
Published: May 2022

Significance

Molecules interacting with metallic nanostructures can show tunable exciton-plasmon coupling, ranging from weak to strong. One factor that influences the interactions is the spatial organization of the molecules relative to the localized plasmon-enhanced electromagnetic fields. In this work, we show that the arrangement of aromatic dye molecules can be tuned within plasmonic hotspots by interfacial engineering of nanoparticle surfaces. By controlling the local chemical and physical interactions, we could modulate lasing thresholds. Surface-functionalized plasmonic metasurfaces open prospects for programmable light-matter interactions at the nanoscale.
Tumor-induced double positive T cells display distinct lineage commitment mechanisms and functions
Authors: Schad Sara E. , Chow Andrew , Mangarin Levi , Pan Heng , Zhang Jiajia , Ceglia Nicholas , Caushi Justina X. , Malandro Nicole , Zappasodi Roberta , Gigoux Mathieu , Hirschhorn Daniel , Budhu Sadna , Amisaki Masataka , Arniella Monica , Redmond David , Chaft Jamie , Forde Patrick M. , Gainor Justin F. , Hellmann Matthew D. , Balachandran Vinod , Shah Sohrab , Smith Kellie N. , Pardoll Drew , Elemento Olivier , Wolchok Jedd D. , Merghoub Taha
Published: May 2022

Transcription factors ThPOK and Runx3 regulate the differentiation of “helper” CD4+ and “cytotoxic” CD8+ T cell lineages respectively, inducing single positive (SP) T cells that enter the periphery with the expression of either the CD4 or CD8 co-receptor. Despite the expectation that these cell fates are mutually exclusive and that mature CD4+CD8+ double positive (DP) T cells are present in healthy individuals and augmented in the context of disease, yet their molecular features and pathophysiologic role are disputed. Here, we show DP T cells in murine and human tumors as a heterogenous population originating from SP T cells which re-express the opposite co-receptor and acquire features of the opposite cell type’s phenotype and function following TCR stimulation. We identified distinct clonally expanded DP T cells in human melanoma and lung cancer by scRNA sequencing and demonstrated their tumor reactivity in cytotoxicity assays. Our findings indicate that antigen stimulation induces SP T cells to differentiate into DP T cell subsets gaining in polyfunctional characteristics.
Gravitational wave memory and the wave equation
Authors: Garfinkle David
Published: May 2022

Gravitational wave memory and its electromagnetic analog are shown to be straightforward consequences of the wave equation. From Maxwell’s equations one can derive a wave equation for the electric field, while from the Bianchi identity one can derive a wave equation for the Riemann tensor in linearized gravity. Memory in both cases is derived from the structure of the source of those wave equations.
UniMAP: model-free detection of unclassified noise transients in LIGO-Virgo data using the temporal outlier factor
Authors: Ding J , Ng R T , McIver J
Published: May 2022

Data from current gravitational wave detectors contains a high rate of transient noise (glitches) that can trigger false detections and obscure true astrophysical events. Existing noise-detection algorithms largely rely on model-based methods that may miss noise transients unwitnessed by auxiliary sensors or with exotic morphologies. We propose the unicorn multi-window anomaly-detection pipeline: a model-free algorithm to identify and characterize transient noise leveraging the temporal outlier factor (TOF) via a multi-window data-resampling scheme. We show this windowing scheme extends the anomaly detection capabilities of the TOF algorithm to resolve noise transients of arbitrary morphology and duration. We demonstrate the efficacy of this pipeline in detecting glitches during LIGO and Virgo’s third observing run, and discuss potential applications.
Simplified Peltier heat pump
Authors: Ficker T
Published: May 2022

A simplified version of the Peltier heat pump has been described and its prototype subjected to experimental testing. The core of the prototype consists of the thermoelectric module TEC1-12714S which is commonly available on the electro market. The simplified Peltier heat pump has shown effective functioning within the temperature difference of ΔT = 20  °C between the cold and hot sides of the used module. Although the presented prototype of the Peltier heat pump does not seem to be practical in thermal building technology, its utilization for illustrating the principle of thermoelectric effect within physical lectures or as an experimental device for measuring its coefficient of performance in student laboratories may be useful.
On-line mechanical life prediction method for a conventional circuit breaker based on multi-parameter particle swarm optimization-support vector regression using vibration detection
Authors: Sun Shuguang , Wen Zhitao , Zhang Wei , Wang Jingqin , Gao Hui
Published: May 2022

For on-line mechanical condition monitoring of conventional circuit breakers, based on the analysis of vibration signal measurements and the generation principle in the circuit breaker breaking motion process, the time parameters for mechanism action with clear physical meaning are correlated with vibration events. Thus, an on-line mechanical life prediction method based on vibration detection and multi-parameter support vector regression (MP-SVR) optimized by particle swarm optimization is proposed. This method aims to use the action time parameter as the main monitoring parameter to reflect the degradation of mechanical conditions and the life failure criterion. First, the complete MPs of life degradation are obtained through the designed on-line measurement algorithm for the action time parameter and the assisted time-domain features of vibration signals in the corresponding time. Then, a quantitative life prediction model is constructed based on MP-SVR. Finally, the degraded MPs are used as input to the prediction model to predict the remaining mechanical life. Our experiment shows that this on-line model for life evaluation is definitely effective and practical in engineering applications.
AFM microfluidic cantilevers as weight sensors for live single cell mass measurements
Authors: Chien Chen-Chi , Jiang Jiaxin , Gong Bin , Li Tao , Gaitas Angelo
Published: May 2022

Reliably measuring small mass changes at the single-cell level is challenging. In this manuscript, we report the use of microfluidic cantilevers in liquid with sub-nanogram scale weight sensing capability for the measurement of cellular mass changes of living single cells. With this instrumentation, we were able to perform fast mass measurements within 3 min. We show results of mass measurements of polystyrene and metal beads of various sizes (smallest weight measured at 280 ± 95 pg) and live single-cell mass measurements in a physiologically relevant environment. We also performed finite element analysis to simulate and optimize the structural design and materials of cantilevers. Our simulation results indicate that using polymer materials, such as SU8 and polyimide, could improve the minimal detectable mass by three-fold compared to conventional silicon cantilevers. The simulations also suggest that smaller dimensions of length, width, and thickness would improve the mass detection capability of microfluidic cantilevers.
Optimized and standardized circular-coil systems for homogeneous magnetic field generation
Authors: Lu Yiwei , Yang Yong , Wang Rumeng , Zhang Ming
Published: May 2022

There is an increasting demand for homogeneous magnetic fields (HMFs) as an exposure resource for electrical immunity tests, biomedical experiments, etc. The design of conventional HMF generators, such as Helmholtz and Barker coils, only focuses on the field homogeneity at the coil center, which leads to limitations in the available HMFworkspace. In this paper, based on a comprehensive definition of the HMF, optimized circular three-coil and four-coil systems are analysed through an optimization method. By standardizing the coil parameters to the HMF parameters, it is easy to scale the coil systems to the desired HMF. In addition, two sets of concise formulae are presented as practical design tools. Compared to Barker coils, the proposed optimized coil systems enable a reduction in both total electrical power and conductor mass by 14.9%–33.6%. Numerical simulations and experimental tests are implemented to show the effectiveness of the theoretical results and the improvement in coil performance.
Reduction of the lasing threshold in optically pumped AlGaN/GaN lasers with two-step etched facets
Authors: Cuesta Sergi , Denaix Lou , Castioni Florian , Dang Le Si , Monroy Eva
Published: May 2022

We report a two-step process to obtain smooth and vertical {10−10} m-plane facets in AlGaN/GaN separate confinement heterostructures designed to fabricate ultraviolet lasers emitting at 355 nm. The process combines inductively coupled plasma reactive ion etching with crystallographic-selective wet etching using a KOH-based solution. The anisotropy in the wet etching allows the fabrication of flat, parallel facets without degradation of the multilayer ensemble. The optical performance of the lasers is strongly improved (reduction of the lasing threshold by a factor of two) when using the two-step process for the definition of the cavity, in comparison to cavities fabricated by mechanical cleaving.
Three studies in high-Tc cuprates
Authors: Marino E C
Published: May 2022

We investigate three fundamental issues in the physics of high-Tc cuprates, from the perspective of a recently proposed comprehensive theory for these materials. (a) Orbital ordering × superconductivity. The first issue is the detailed microscopic mechanism that produces an attractive interaction between holes in high-Tc cuprates. (b) Dispersion relation × pseudogap order parameter. The second issue refers to the existence of a pseudogap order parameter, which would be different from zero all over the pseudogap phase and would vanish elsewhere. (c) Chemical potential × quantum critical point location. The third issue concerns the debate as to whether the quantum critical point, located where the pseudogap transition line T*(x) meets the T = 0 axis is inside the superconducting dome or at its boundary. We obtain clearcut solutions for the three issues.
The enhancement of the optical properties of CdS/PMMA by adding fullerence C60
Authors: Maged Fatma Abdel , Mansour A F
Published: May 2022

The C60/CdS//PMMA nanocomposites were synthesized via the casting method. Prepared samples were analyzed by XRD, SEM, TEM, and FTIR analysis. UV–visible spectroscopy was used to evaluate optical properties of CdS//PMMA& C60/CdS//PMMA nanocomposite. The Eg decreased from 2.65 eV to 2 eV with the increment CdS content. The C60 nanoparticles have a significant influence, The absorption of C60 CdS/PMMA nanocomposite is enhanced compared to CdS/PMMA Fullerene is an effective strategy for improving CdS photocatalytic performance. This enhancement is due to the electronic transition of π to π* for C60 and n to π* between the n orbit of the CdS and C60. Degradation efficiency is 17% for CdS/PMMA, and 33% for C60/CdS/PMMA nanocomposite. Thus C60/CdS/PMMA can be used for optoelectronic devices, solar cell applications and photocatalytic activity.
Anomalous transport for multispecies reactive system with first order decay: time-fractional model
Authors: Chaudhary Manish , Singh Mritunjay Kumar
Published: May 2022

The prediction of pollutant migration and its concentration variation in the subsurface hydrology is vitally requisite for the assessment and restorative treatment of polluted groundwater system. Pollutant migration for the multispecies reactive system cannot be reliably investigated by classical form of convection-dispersion equation (CDE), due to the presence of more than one reactive species. This paper establishes a time-fractional model for multispecies reactive system under the first order sequential reaction network to understand the anomalous or non-Fickian migration phenomenon for reactive pollutants. At present, most of the fractional models are presented for the classical CDE to investigate migration phenomenon for single species system, not for the multispecies reactive system due to the complexity of the modelled framework. The impact of fractional derivative model is analysed for variable dependent migration parameters and constant parameters, both for the multispecies reactive migration phenomenon. The fractional derivative is expressed in the Caputo sense and to handle the non-linearity of problem, Homotopy perturbation method (HPM) is adopted. The advantage of this method, to get the solutions, is that the HPM is independent of small parameters required for the deformation process as used in other existing perturbation techniques, which make it much more convenient to use for non-linear systems. The impact of the fractional derivative index and other migration parameters is graphically depicted for the reactive species and significant influence of fractional term is observed. The derived solutions are then validated by using the corresponding solutions obtained by other existing well-established methods to ensure the convergence of the HPM solutions. As there do not exist any solutions for such fractional models for multispecies reactive system, this study may be advantageous to convey better understanding for the anomalous or non-Fickian migration for reactive pollutants and their remediation planning in the groundwater resources.
Study of electronic and optical response of Zn-CeO2 using first principle and experimental investigations
Authors: Aslam Shamim , Amiza Ms , Siddig Abubaker , Al Zayed Nasser Saleh , Ramay Shahid M , Saleem Murtaza
Published: May 2022

Ceria (CeO2) is an important material mainly for microelectronic and fuel-cell applications due to having high dielectric constant and good catalytic properties. The first principle and experimental investigations were carried out to study the effect of Zn incorporation on the electronic and optical response of CeO2. Density of states spectra depict the prominent hybridization of Ce–f and O–p states while band structure reveals the decrease in bandgap with the incorporation of metallic Zn content in ceria structure. X-ray diffraction analysis detects the crystalline traces of CeO2 in pristine and doped thin films. Field emission scanning electron micrographs and energy dispersive x-ray spectra of synthesized thin films present the uniform distribution of grains with clear grain boundaries with expected elemental contents. The experimental observations comparatively follow the trend of simulation curves. Optical studies demonstrate a clear increment in absorption coefficient, optical conductivity, and real epsilon with Zn incorporation in ceria which makes these compositions favorable for applications in modern electronic devices.
Chiral symmetry protected topological nodal superconducting phase and Majorana Fermi arc
Authors: Lu Mei-Ling , Wang Yao , Zhang He-Zhi , Chen Hao-Lin , Cui Tian-Yuan , Luo Xi
Published: May 2022

With an external in-plane magnetic field, we show the emergence of a topological nodal superconducting phase of the two-dimensional topological surface states. This nodal superconducting phase is protected by the chiral symmetry with a non-zero magnetic field, and there are corresponding Majorana Fermi arcs (also known as flat band Andreev bound states) connecting the two Majorana nodes along the edges, similar to the case of Weyl semimetal. The topological nodal superconductor is an intermediate phase between two different chiral superconductors, and is stable against the effects of substrates. The two-dimensional effective theory of the nodal superconducting phase also captures the low energy behavior of a three-dimensional lattice model which describes the iron-based superconductor with a thin film geometry. The localizations of the Majorana nodes can be manipulated through external in-plane magnetic fields, which may introduce a non-trivial topological Berry phase between them.
Variational approximation methods for long-range force transmission in biopolymer gels
Authors: Wang Haiqin , Xu Xinpeng
Published: May 2022

The variational principle of minimum free energy (MFEVP) has been widely used in research of soft matter statics. The MFEVP can be used not only to derive equilibrium equations (including both bulk equations and boundary conditions), but also to develop direct variational methods (such as Ritz method) to find approximate solutions to these equilibrium equations. We apply these variational methods to study long-range force transmission in nonlinear elastic biopolymer gels. It is shown that the slow decay of cell-induced displacements measured experimentally for fibroblast spheroids in three-dimensional fibrin gels can be well explained by variational approximations based on the three-chain model of biopolymer gels.
Final bound-state formation effect on dark matter annihilation *
Authors: Wang Xinyu , Zhong Fucheng , Luo Feng
Published: May 2022

If two annihilation products of dark matter (DM) particles are non-relativistic and couple to a light force mediator, their plane wave functions are modified due to multiple exchanges of the force mediator. This gives rise to the final state Sommerfeld (FSS) effect. It is also possible that the final state particles form a bound state. Both the FSS effect and final bound-state (FBS) effect need to be considered in the calculation of the DM relic abundance. The annihilation products can be non-relativistic if their masses are comparable to those of the annihilating DM particles. We study the FSS and FBS effects in the mass-degenerate region using two specific models. Both models serve to illustrate different partial-wave contributions in the calculations of the FSS and FBS effects. We find that the FBS effect can be comparable to the FSS effect when the annihilation products couple strongly with a light force mediator. Those effects significantly modify the DM relic abundance.
First operations with caesium of the negative ion source SPIDER
Authors: Sartori E. , Agostini M. , Barbisan M. , Bigi M. , Boldrin M. , Brombin M. , Casagrande R. , Dal Bello S. , Dan M. , Duteil B.P. , Fadone M. , Grando L. , Maistrello A. , Pavei M. , Pimazzoni A. , Poggi C. , Rizzolo A. , Shepherd A. , Ugoletti M. , Veltri P. , Zaniol B. , Agnello R. , Agostinetti P. , Antoni V. , Aprile D. , Candeloro V. , Cavallini C. , Cavazzana R. , Cavenago M. , Chitarin G. , Cristofaro S. , Dalla Palma M. , Delogu R. , De Muri M. , Denizeau S. , Fellin F. , Ferro A. , Gasparrini C. , Jain P. , Luchetta A. , Manduchi G. , Marconato N. , Marcuzzi D. , Mario I. , Milazzo R. , Pasqualotto R. , Patton T. , Pilan N. , Recchia M. , Rigoni-Garola A. , Segalini B. , Siragusa M. , Spolaore M. , Taliercio C. , Toigo V. , Zagorski R. , Zanotto L. , Zaupa M. , Zuin M. , Serianni G.
Published: May 2022

The negative-ion based neutral beam injector for heating and current drive of the ITER plasma (ITER HNB) is under development, at present focusing on the optimization of the full-scale plasma source in the SPIDER test stand. The production of H− or D− ions in the ion source is based on the low work function surfaces obtained by caesium evaporation. This paper describes the caesium conditioning procedure and the corresponding beam performances during the first operation of SPIDER with caesium. Technical solutions to overcome present limitations of the test stand are described. The influence of source parameters on the caesium effectiveness was investigated in short beam pulse operation; with total radio-frequency (RF) power of 400 kW and filling pressure below 0.4 Pa, and a limited number of extraction apertures, a negative ion current density of about 200 A m−2 was extracted in hydrogen, with beam energy lower than 60 keV. Beam optics and beam uniformity were assessed thanks to the acceleration of isolated ion beamlets. A possible procedure to accelerate a uniform beam was demonstrated at low RF power. The results obtained in this first investigation provided key indications on the operation of one of the largest existing sources of accelerated negative hydrogen-like ions.
A humidity compensation method for a temperature and humidity sensor
Authors: Yang Yuchuan , Liang Xiuxiu , Hong Ting , Li Xin
Published: May 2022

This paper introduces the method of humidity compensation in the temperature and humidity sensor to improve the measurement accuracy of humidity. The nonlinearity of humidity and humidity affected by temperature are compensated in circuit and data processing respectively. On the circuit, the sampling principle and the structure of the operational amplifier in the design are introduced. The data processing is mainly polynomial fitting of the chip test data by MATLAB software, so as to improve the humidity measurement accuracy. After the final fitting, the humidity error can reach ±1.5RH in the range of 10 °C to 50 °C.
Design and Implementation of a Direct Memory Access ControllerBased on Microcontroller Unit
Authors: Lu Chao , Yang Haosen , Wu Qi
Published: May 2022

With increasing IoT technology, the application of MCU is becoming more and more extensive, and higher requirements are put forward for the functions and data processing capabilities of MCU. This trend means the amount of data that the MCU needs to process in the system has increased sharply, so this paper proposes a hardware design scheme for a DMA controller based on the AHB-Lite protocol to replace the MCU to transfer data to improve system performance. The controller supports 8 transfer channels and adopts the method of fixed priority level arbitrating to select channels. The channel source and destination data width and burst type are configurable. In the process of data burst transfer, the condition of crossing the 1K address boundary is taken into consideration. At the same time, the design adopts the method that 8 transfer channels share a buffer FIFO to optimize the area of the controller.
Study on Short Circuit Current Calculation of EHV Overhead Line-GIL Hybrid Line
Authors: Jia Honggang , Yan Na , Wang Wei , Wang Zhe , Sun Yi , Xu Yiqing , Lu Shan
Published: May 2022

GIL electrical parameters are different from overhead lines. With the increasing application of GIL in actual projects, the influence of GIL needs to be considered when calculating the short-circuit current of the power grid. In this paper, the calculation of three-phase short-circuit current is carried out for the EHV double-circuit overhead line on the same tower with GIL. First, the electrical parameters of EHV GIL are calculated. The positive sequence resistance, reactance and capacitance values of a typical GIL are calculated. Secondly, EMTP-ATP software is used to modelling and simulation. The influence of GIL length on the short-circuit current and the position of short-circuit fault is studied respectively. Finally, the influence of the GIL unit length modelling accuracy and the grounding mode of the metal shell on the short-circuit current is studied. The research results of this paper can provide a theoretical reference for GIL simulation modelling and the evaluation of the impact of system short-circuit current.
Methods for increasing the conversion efficiency of solar cells
Authors: Wang Yuxuan
Published: May 2022

Solar energy is the most promising new energy. It is inexhaustible, and the use of solar energy will not damage the earth’s ecology and environment; Safe, no pollution, low utilization cost, and not restricted by geographical conditions. The solar cell converts light energy into electrical energy and transmits it to the load. When the non-uniform semiconductor (PN junction) is irradiated with light of appropriate wavelength, the electromotive force is generated inside the semiconductor due to the action of the internal field. Solar cell is a semiconductor photovoltaic element that converts light energy into electrical energy, using the photovoltaic effect of semiconductor. The main focus of solar cell design is to increase their conversion efficiency. This paper focuses on methods for increasing the conversion efficiency of solar cells, which can lead to more efficient energy for space technology. The conversion efficiency of a solar cell is defined as the ratio of the output electrical energy to the incident light energy. This paper focuses on the following methods to increase the conversion efficiency: enabling the solar cells to correspond to a wider spectrum and gradient doping. We have found that some of these methods can be applied to different solar cell materials. They are also quite realizable and can be put into practical production.
Fault identification of fan blade based on improved ResNet-18
Authors: Zhang Hengfu , Wang Fang
Published: May 2022

With the continuous development of the wind industry, wind turbine blade failure causes wind turbine shutdown, which damages the revenue of wind power. In order to more effectively detect the damage on the surface of wind turbine blade. By comparing ResNet-18 /50, VGG-19 and GoogLeNet models, ResNet-18 has the advantages of short training time and high accuracy. Therefore, ResNet-18 convolutional neural network is selected as the basic network, and a deep learning training and detection model is built based on MATLAB. In order to further optimize the model, multiple convolution kernel is selected for the main branch of residual structure of ResNet-18 to extract features, and add 3×3 pool layer, it is used to improve the learning ability of the model. In addition, Aadm, Sgdm and Rmsprop optimization algorithms are added to further improve the robustness of the model. Experiments show that the classification and recognition accuracy of the improved ResNet-18 model for fan blades is 94.17%, which is 2.5% higher than that of the original model. The improved ResNet-18 model has good recognition effect,it improves a faster and more accurate solution for fan blade surface damage identification in complex weather environment.
Analysis and Research of Pin Void for High Voltage Intelligent Power Module
Authors: Hua Qing , Wang Huanyu , Pan Zhijian , Zhang Tuming , Feng Yuxiang
Published: May 2022

Pin void is one of the key factors affecting the reliability of intelligent power module. It is difficult to accurately identify and measure whether it is a pin void and its size through X-ray equipment. This paper investigates the pin void analytical method of high voltage intelligent power module. An effective combinatorial analysis method is provided. Besides, pin void is compared and studied with different situations of reflow soldering, pin pressure bar and pin type in this research. The effects of different situations of these parameters on pin void are evaluated.
Design of Magnetic Levitation Shaftless Contra-Rotating Propeller and Feasibility Analysis of Drive System
Authors: Fang Xiaoyi
Published: May 2022

In order to solve the problems of vibration, noise, shaft seal and complex structure of the marine propeller, the author proposes a new type of magnetic levitation(Maglev) shaftless contra-rotating propeller(CRP), analyzes the mechanical structure design and component layout of the propeller, and uses 3D modeling software to model and assemble components. The propeller is mainly composed of rotors, shroud, stator winding, sensors, control circuit and other components, and its control system is further divided into a levitation system and drive system. Then the drive system of the propeller is studied, its mathematical model is analyzed, and the drive system model is built in MATLAB/Simulink to analyse the feasibility of the propeller drive system, and a PID controller is added to make the system have good dynamic response performance.
Research on multi-fault diagnosis method and test platform of main transmission Machinery of wind Turbine based on electrical signal
Authors: Shi Qiong , Zhou JingCi , Xiang JianPing , Shi YangChun
Published: May 2022

An optimised design was carried out based on the original semi-physical simulation system for the main drive chain of a wind turbine. The input of upper computer simulating wind condition, the safety control of electrical signal and vibration signal acquisition module, relay and AC contactor and dual motor control were added. Simultaneously, the simulation schemes of some common faults on the main drive of wind turbines were also designed in order to perform the experimental simulation of the single fault and multi fault. The primary purpose of simulation is to use practical approaches(such as FFT,EMD)to analyze the changes of the fault signals based on the collected electrical signals, and to determine whether there is a fault through comparison and theoretical analysis. In addition, it aimed for verifying the feasibility of electrical signals under multi-fault conditions, and discussing advantages of electrical signals over vibration signals.
Failure analysis of smoke lampblack machine crack
Authors: Kong Huanping , Jiang Tao , Zhao Kai , Liu Changkui
Published: May 2022

The smoke lampblack machine cracked in use. Through macro and micro morphology observation, energy spectrum detection, metallographic examination and finite element simulation calculation and analysis, the failure nature and reason of the smoke lampblack machine were determined. The results showed that the cracking property was corrosion fatigue, and the cracking of the smoke lampblack machine was caused by the damage of the protective layer in the vibration environment. It was suggested that the surface protection of smoke lampblack machine should be strengthened and the structural design of stress concentration should be improved.
Control system of the CYRCé beamlines
Authors: Maazouzi C. , Adam T. , Bouquerel E. , Pellicioli M. , Schuler J. , Rousseau M. , Traykov E. , Graehling P.
Published: May 2022

The first two extension beamlines from the CYRCé cyclotron have been developed and recently commissioned at IPHC Strasbourg. One beamline is devoted to radiobiological experiments, the PRECy project, while the other one is for testing silicon detector modules in the framework of the CMS experiment. The development of the control system of these beamlines is reported in this paper.
Drive beam sources and longitudinal shaping techniques for beam driven accelerators
Authors: Lemery F. , Andonian G. , Doebert S. , Ha G. , Lu X. , Power J. , Wisniewski E.
Published: May 2022

Linear colliders are an attractive platform to explore
high-precision physics of newly discovered particles. The recent
significant progress in advanced accelerator technologies has
motivated their applications to colliders which has been discussed
in the alegro workshop. In this paper we discuss structure
wakefield acceleration, namely collinear wakefield acceleration and
two-beam acceleration. We especially discuss available drive and
witness beam sources based on L and S-band radiofrequency
technology, and also summarize available and forthcoming
longitudinal shaping techniques to improve the overall acceleration
efficiency via the transformer ratio.
Cluster mean field plus density matrix renormalization theory for the Bose Hubbard models
Authors: Gaude Pallavi P , Das Ananya , Pai Ramesh V
Published: May 2022

The cluster mean-field with density matrix renormalization (CMFT + DMRG) method which combines the simplicity of the mean-field theory and the numerical power of the density-matrix renormalization group method is applied to understand the quantum phases of the one-dimensional Bose–Hubbard models. We show that the CMFT + DMRG method is an effective numerical technique with moderate computational resources to determine relevant order parameters and correlation functions of large one-dimensional systems. We apply the CMFT + DMRG for the Bose Hubbard and extended Bose Hubbard models to account for the superfluid, Mott insulator, and density wave phases in these models. Our results are in good agreement with the known phase diagram of these models, demonstrating the efficacy of this method.
Three-fold way of entanglement dynamics in monitored quantum circuits
Authors: Kalsi T , Romito A , Schomerus H
Published: May 2022

We investigate the measurement-induced entanglement transition in quantum circuits built upon Dyson’s three circular ensembles (circular unitary, orthogonal, and symplectic ensembles; CUE, COE and CSE). We utilise the established model of a one-dimensional circuit evolving under alternating local random unitary gates and projective measurements performed with tunable rate, which for gates drawn from the CUE is known to display a transition from extensive to intensive entanglement scaling as the measurement rate is increased. By contrasting this case to the COE and CSE, we obtain insights into the interplay between the local entanglement generation by the gates and the entanglement reduction by the measurements. For this, we combine exact analytical random-matrix results for the entanglement generated by the individual gates in the different ensembles, and numerical results for the complete quantum circuit. These considerations include an efficient rephrasing of the statistical entangling power in terms of a characteristic entanglement matrix capturing the essence of Cartan’s KAK decomposition, and a general result for the eigenvalue statistics of antisymmetric matrices associated with the CSE.
The discrete random energy model and one step replica symmetry breaking
Authors: Derrida Bernard , Mottishaw Peter
Published: May 2022

We solve the random energy model when the energies of the configurations take only integer values. In the thermodynamic limit, the average overlaps remain size dependent and oscillate as the system size increases. While the extensive part of the free energy can still be obtained by a standard replica calculation with one step replica symmetry breaking, it is no longer possible to recover the overlaps in this way. A possible way to adapt the replica approach is to allow the sizes of the blocks in the Parisi matrix to fluctuate and to take complex values.