bluuebunny/crossref_metadata_2025 huggingface dataset:
Constraints on the mass and on the atmospheric composition and evolution of the low-density young planet DS Tucanae A b
Authors: Benatti S. , Damasso M. , Borsa F. , Locci D. , Pillitteri I. , Desidera S. , Maggio A. , Micela G. , Wolk S. , Claudi R. , Malavolta L. , Modirrousta-Galian D.
Published: April 2021

Context. Observations of young close-in exoplanets are providing initial indications for the characteristics of the population and clues to the early stages of their evolution. Transiting planets at young ages are also key benchmarks for our understanding of planetary evolution via the verification of atmospheric escape models.

Aims. We performed radial velocity (RV) monitoring of the 40 Myr old star DS Tuc A with HARPS at the ESO-3.6 m to determine the planetary mass of its 8.14-day planet, which was first revealed by the NASA TESS satellite. We also observed two planetary transits with HARPS and ESPRESSO at ESO-VLT to measure the Rossiter-McLaughlin (RM) effect and characterise the planetary atmosphere. We measured the high-energy emission of the host with XMM-Newton observations to investigate models for atmospheric evaporation.

Methods. We employed a Gaussian Processes (GP) regression to model the high level of the stellar activity, which is more than 40 times larger than the expected RV planetary signal. GPs were also used to correct the stellar contribution to the RV signal of the RM effect. We extracted the transmission spectrum of DS Tuc A b from the ESPRESSO data and searched for atmospheric elements and molecules either by single-line retrieval and by performing cross-correlation with a set of theoretical templates. Through a set of simulations, we evaluated different scenarios for the atmospheric photo-evaporation of the planet induced by the strong XUV stellar irradiation.

Results. While the stellar activity prevented us from obtaining a clear detection of the planetary signal from the RVs, we set a robust mass upper limit of 14.4 M⊕ for DS Tuc A b. We also confirm that the planetary system is almost (but not perfectly) aligned. The strong level of stellar activity hampers the detection of any atmospheric compounds, which is in line with other studies presented in the literature. The expected evolution of DS Tuc A b from our grid of models indicates that the planetary radius after the photo-evaporation phase will be 1.8–2.0 R⊕, falling within the Fulton gap.

Conclusions. The comparison of the available parameters of known young transiting planets with the distribution of their mature counterpart confirms that the former are characterised by a low density, with DS Tuc A b being one of the less dense. A clear determination of their distribution is still affected by the lack of a robust mass measurement, particularly for planets younger than ~100 Myr.
Symmetry and scaling limits for matching of implicit surfaces based on thin shell energies
Authors: Iglesias José A.
Published: April 2021

In a recent paper by Iglesias et al. [Found. Comput. Math. 18 (2018) 891–927] a variational model for deformations matching a pair of shapes given as level set functions was proposed. Its main feature is the presence of anisotropic energies active only in a narrow band around the hypersurfaces that resemble the behavior of elastic shells. In this work we consider some extensions and further analysis of that model. First, we present a symmetric energy functional such that given two particular shapes, it assigns the same energy to any given deformation as to its inverse when the roles of the shapes are interchanged, and introduce the adequate parameter scaling to recover a surface problem when the width of the narrow band vanishes. Then, we obtain existence of minimizing deformations for the symmetric energy in classes of bi-Sobolev homeomorphisms for small enough widths, and prove a Γ-convergence result for the corresponding non-symmetric energies as the width tends to zero. Finally, numerical results on realistic shape matching applications demonstrating the effect of the symmetric energy are presented.
A Comprehensive Functional Analysis in Patients after Atrial Switch Surgery
Authors: Vollmer Daniela , Hornung Andreas , Wiegand Gesa , Apitz Christian , Latus Heiner , Hofbeck Michael , Sieverding Ludger
Published: April 2021

Background Long-term course after atrial switch operation is determined by increasing right ventricular (RV) insufficiency. The aim of our study was to investigate subtle functional parameters by invasive measurements with conductance technique and noninvasive examinations with cardiac magnetic resonance imaging (CMR).

Methods We used invasive (pressure–volume loops under baseline conditions and dobutamine) and noninvasive techniques (CMR with feature tracking [FT] method) to evaluate RV function. All patients had cardiopulmonary exercise testing (CPET).

Results From 2011 to 2013, 16 patients aged 28.2 ± 7.3 (22–50) years after atrial switch surgery (87.5% Senning and 12.5% Mustard) were enrolled in this prospective study. All patients were in New York Heart Association (NYHA) class I to II and presented mean peak oxygen consumption of 30.1 ± 5.7 (22.7–45.5) mL/kg/min. CMR-derived end-diastolic volume was 110 ± 22 (78–156) mL/m2 and RV ejection fraction 41 ± 8% (25–52%). CMR-FT revealed lower global systolic longitudinal, radial, and circumferential strain for the systemic RV compared with the subpulmonary left ventricle. End-systolic elastance (Ees) was overall reduced (compared with data from the literature) and showed significant increase under dobutamine (0.80 ± 0.44 to 1.89 ± 0.72 mm Hg/mL, p ≤ 0.001), whereas end-diastolic elastance (Eed) was not significantly influenced (0.11 ± 0.70 to 0.13 ± 0.15 mm Hg/mL, p = 0.454). We found no relevant relationship between load-independent conductance indices and strain or CPET parameters. Conductance analysis revealed significant mechanical dyssynchrony, higher during diastole (mean 30 ± 4% baseline, 24 ± 6% dobutamine) than during systole (mean 17 ± 6% baseline, 19 ± 7% dobutamine).

Conclusions Functional assessment of a deteriorating systemic RV remains demanding. Conductance indices as well as the CMR-derived strain parameters showed overall reduced values, but a significant relationship was not present (including CPET). Our conductance analysis revealed intraventricular and predominantly diastolic RV dyssynchrony.
Infinitely many multi-vortex solutions of the magnetic Ginzburg–Landau equation with external potentials in R2
Authors: Wei Juncheng , Wu Yuanze
Published: April 2021

In this paper, we consider the magnetic Ginzburg–Landau equation with external potentials μV(x) for the type II superconductors. We prove, by reduction arguments, that under suitable conditions on V(x), the magnetic Ginzburg–Landau equation with external potentials in R2 has infinitely many multi-vortex solutions for μ > 0 being sufficiently small.
Poling effect on the electrostrictive and piezoelectric response in CH3NH3PbI3 single crystals
Authors: Li Weiwei , Man Zhenyong , Zeng Jiangtao , Zheng Liaoying , Zeng Huarong , Zhao Kunyu , Li Guorong , Kassiba Abdelhadi
Published: April 2021

Methylammonium lead triiodide perovskites (MAPbI3) have demonstrated a large electrostrictive strain up to 1%, which was theoretically proved to be related to the additional defects under applied bias voltages. However, as this effect was detected only at a low frequency, we explored the electrostrictive response at a higher frequency (4 kHz) by using ac poling at 1 Hz. In such conditions, the electrostrictive coefficient was evaluated at –45.7 nm2 V−2, i.e., quite larger than the results under dc poling or in unpoled samples. The occurrence of a high-frequency electrostrictive effect may be correlated with the defects that rise in the ac poled samples from the ion migration under reverse bias as it was also demonstrated from the shift of the dielectric loss peak in the considered systems. In parallel to the electrostrictive effect, the piezoelectric response shows a drastic increase after the ac and dc poling due to the lattice distortion induced by the applied electric field. Based on the above approach, the achieved electrostrictive and piezoelectric responses at 4 kHz in MAPbI3 may open opportunities in the area of actuators, energy-harvesting, and micro-electromechanical systems.
Symmetry transformations of extremals and higher conserved quantities: Invariant Yang–Mills connections
Authors: Accornero Luca , Palese Marcella
Published: April 2021

We characterize symmetry transformations of Lagrangian extremals generating “on shell” conservation laws. We relate symmetry transformations of extremals to Jacobi fields and study symmetries of higher variations by proving that a pair given by a symmetry of the lth variation of a Lagrangian and by a Jacobi field of the sth variation of the same Lagrangian (with s < l) is associated with an “off shell” conserved current. The conserved current associated with two symmetry transformations is constructed, and as a case of study, its expression for invariant sets of Yang–Mills connections on Minkowski space-times is obtained.
Parallel optically detected magnetic resonance spectrometer for dozens of single nitrogen-vacancy centers using laser-spot lattice
Authors: Cai Mingcheng , Guo Zhongzhi , Shi Fazhan , Li Chunxing , Wang Mengqi , Ji Wei , Wang Pengfei , Du Jiangfeng
Published: April 2021

We develop a parallel optically detected magnetic resonance (PODMR) spectrometer to address, manipulate, and read out an array of single nitrogen-vacancy (NV) centers in diamond in parallel. In this spectrometer, we use an array of micro-lenses to generate a 20 × 20 laser-spot lattice (LSL) on the objective focal plane and then align the LSL with an array of single NV centers. The quantum states of NV centers are manipulated by a uniform microwave field from a Ω-shape coplanar coil. As an experimental demonstration, we observe 80 NV centers in the field of view. Among them, magnetic resonance (MR) spectra and Rabi oscillations of 18 NV centers along the external magnetic field are measured in parallel. These results can be directly used to realize parallel quantum sensing and multiple times speedup compared with the confocal technique. Regarding the nanoscale MR technique, PODMR will be crucial for a high throughput single molecular MR spectrum and imaging.
Multi-fluid and kinetic models of partially ionized magnetic reconnection
Authors: Jara-Almonte J. , Murphy N. A. , Ji H.
Published: April 2021

Magnetic reconnection in partially ionized plasmas is a ubiquitous and important phenomenon in both laboratory and astrophysical systems. Here, simulations of partially ionized magnetic reconnection with well-matched initial conditions are performed using both multi-fluid and fully-kinetic approaches. Despite similar initial conditions, the time-dependent evolution differs between the two models. In multi-fluid models, the reconnection rate locally obeys either a decoupled Sweet–Parker scaling, where neutrals are unimportant, or a fully coupled Sweet–Parker scaling, where neutrals and ions are strongly coupled, depending on the resistivity. In contrast, kinetic models show a faster reconnection rate that is proportional to the fully-coupled, bulk Alfvén speed, vA⋆. These differences are interpreted as the result of operating in different collisional regimes. Multi-fluid simulations are found to maintain νniL/vA⋆≳1, where νni is the neutral–ion collision frequency and L is the time-dependent current sheet half-length. This strongly couples neutrals to the reconnection outflow, while kinetic simulations evolve to allow νniL/vA⋆<1, decoupling neutrals from the reconnection outflow. Differences in the way reconnection is triggered may explain these discrepancies.
Ta-doped SrTiO3 epitaxial thin film: A promising perovskite for optoelectronics
Authors: Arya Mamta , Kumar Shammi , Hasina Dilruba , Ojha Sunil , Arora Alisha , Malik Vivek Kumar , Mitra Anirban , Som Tapobrata , Dhar Sankar
Published: April 2021

SrTiO3 is a wide bandgap cubic perovskite oxide and displays many exotic properties, i.e., transparent conductivity, photocatalysis, metallicity, ferroelectricity, superconductivity, colossal magnetoresistance, two-dimensional electron gas, etc., due to the manipulations of defect chemistry and constituent elements via impurity doping. This paper reports on the intricacy of the structural and optoelectronic properties of the epitaxially stabilized 5 at. % Ta-doped SrTiO3 (001) thin films on LaAlO3 (001) substrates by systematically varying the growth temperature and oxygen partial pressure during the pulsed laser deposition process. The influences of Ta dopant and growth parameters on the epitaxial quality of these layers are understood by determining the dopant location and its concentration in the SrTiO3 lattice. The complex relationships of optical and electronic properties on growth parameters, dopant concentration, and single crystal quality of the films are demonstrated. The observed low resistivity (∼5 × 10−3 Ω cm) and high optical transparency (∼85%–90%) of optimized Ta-doped SrTiO3 films offer it as an exciting material for next generation transparent optoelectronics.
Implementation and data processing of a five-channel microwave interferometer with high temporal resolution and low noise on Sino-UNIted Spherical Tokamak
Authors: Su Pengjuan , Zhong Heng , Tan Yi , Gao Zhe , Zai Yingqi , Liu Haiqing , Zeng Long , Zhu Xiang , Ling Bili , Cheng Zhengbo , Liu Wenbin , Wang Shouzhi , Wang Binbin
Published: April 2021

A five-channel microwave interferometer with high temporal resolution and high phase resolution has been developed for measuring electron density profiles and fluctuations on the Sino-UNIted Spherical Tokamak. A correction algorithm, based on the low signal amplitude detection, is proposed to eliminate the fringe jump errors. The correction algorithm achieves an accuracy of 92%. The density profile is reconstructed through the Park-matrix method, with the geometry of magnetic surfaces calculated by the equilibrium fitting. The reconstructed density profiles for discharges with supersonic molecular beam injection are in good agreement with the results of another 94 GHz single-channel horizontal interferometer and the Langmuir probes. The temporal resolution of the system is 0.5 µs and the line-integrated electron density resolution is 1 × 1015 m−2, which benefits from the single sideband modulation technique. Therefore, the multichannel interferometer system is capable of studying the details of the high-frequency (up to 200 kHz) density fluctuation such as that in the minor disruption event.
Lindblad parameters from high resolution spectroscopy to describe collision-induced rovibrational decoherence in the gas phase—Application to acetylene
Authors: Aerts Antoine , Vander Auwera Jean , Vaeck Nathalie
Published: April 2021

Within the framework of the Lindblad master equation, we propose a general methodology to describe the effects of the environment on a system in the dilute gas phase. The phenomenological parameters characterizing the transitions between rovibrational states of the system induced by collisions can be extracted from experimental transition kinetic constants, relying on energy gap fitting laws. As the availability of these kinds of experimental data can be limited, this work relied on experimental line broadening coefficients, however still using energy gap fitting laws. The 3 μm infrared spectral range of acetylene was chosen to illustrate the proposed approach. The method shows fair agreement with available experimental data while being computationally inexpensive. The results are discussed in the context of state laser quantum control.
Effect of surface contact angle on the wall impingement of a power-law liquid jet
Authors: Li Penghui , Yang Lijun , Fu Qingfei
Published: April 2021

This study theoretically investigated the impinging liquid sheet, formed by a power-law liquid jet obliquely encroaching on a wall surface. Based on the control volume method, the governing equations of the liquid sheet were established through force balance analysis at the curved edge. To solve the governing equations, energy conservation in the theoretical model was also considered throughout the impinging process. Typical working conditions were selected to validate the theoretical predictions. The results showed that the theoretical inner counter of liquid sheet agreed well with experimental data. Based on the theoretical model, influence of rheological parameters, surface contact angle, and surface tension coefficient are discussed, respectively. It is concluded that the surface contact angle could affect liquid sheet size by changing the total surface tension force at the rim, as well as the surface energy variation in the energy conservation equation.
Blue and green double band luminescent carbon quantum dots: Synthesis, origin of photoluminescence, and application in white light-emitting devices
Authors: Chen Xifang , Wu Wenhui , Zhang Wenxia , Wang Ziye , Fu Zhenjin , Zhou Lei , Yi Zao , Li Gongfa , Zeng Liangcai
Published: April 2021

Carbon quantum dots (CQDs) have become an excellent candidate for light-converting phosphors. However, it is a challenge to develop white emission CQDs and overcome the agglomeration in the process of solid-state CQDs. Here, white fluorescence CQDs with graphite core structure were synthesized by a one-step hydrothermal method from 1,3-dihydroxynaphthalene and hydrochloric acid. The photoluminescence spectra and surface structure characterization along with UV-Vis absorption spectrum, photoluminescence excitation, and time-resolved photoluminescence spectra together reveal the luminescence of CQDs stems from carbon-oxygen-related surface fluorophores. The principle of solvent similarity compatibility is an effective thought to choose isolating matrix material for the sake of overcoming the agglomeration of CQDs in the process of forming solid film. Solid-state white light emitting device (WLED) was fabricated using the CQDs embedded in polymethyl methacrylate matrix as a single white-light converter excited by a 365 nm UV-LED chip. The fabricated WLED based on CQDs is cold white light source with CIE coordinates (0.3122, 0.3429) and with CCT of 6428 K.
On the characterization of constitutive equations for third-grade viscous Korteweg fluids
Authors: Gorgone Matteo , Rogolino Patrizia
Published: April 2021

We consider a model of a third-grade viscous Korteweg-type fluid in three space dimensions and apply the extended Liu procedure in order to explicitly solve the constraints imposed by the entropy principle on the nonlocal constitutive relations. We detail the algorithm we use and are able to characterize the material functions involved in the constitutive equations. In a natural way, the application of the extended Liu procedure allows us to recover an extra-term in the entropy flux, preserving all the features of third-grade viscous Korteweg-type fluids. Moreover, a further constraint, in order to avoid that at equilibrium only very special phase boundaries are admissible, is investigated.
Modifications in the nanoparticle-protein interactions for tuning the protein adsorption and controlling the stability of complexes
Authors: Kumar Sugam , Saha Debasish , Takata Shin-ichi , Aswal Vinod K. , Seto Hideki
Published: April 2021

We report the pathways to suppress or enhance the protein adsorption on nanoparticles and thereby control the stability of the nanoparticle-protein complexes with the help of selective additives. This has been achieved by tuning the electrostatic interaction between the nanoparticles and proteins, in the presence of surfactant and multivalent counterions. The preferential binding of the proteins with the surfactant and multivalent ions induced charge reversibility of nanoparticles can lead to adsorption of an otherwise non-adsorbing protein and vice versa. The findings are demonstrated for anionic silica nanoparticles and two globular proteins [lysozyme (cationic) and bovine serum albumin (BSA) (anionic)] as model systems, in the presence of two ionic surfactants [anionic sodium dodecyl sulfate (SDS) and cationic dodecyltrimethylammonium bromide (DTAB)], and ZrCl4 as multivalent salt. Small-angle neutron scattering with the unique advantage of contrast variation has been used to probe the role of individual components in the multi-component system. It is shown that the non-adsorbing behavior of BSA with silica nanoparticles changes into adsorbing in the presence of oppositely charged DTAB surfactant, whereas the strong adsorbing behavior of lysozyme on nanoparticles modifies to be non-adsorbing in the presence of oppositely charged SDS surfactant. The presence of multivalent counterions (ZrCl4) leads the charge reversal of the nanoparticles, transforming the lysozyme from adsorbing to non-adsorbing, and no significant change in the behavior of BSA. The results presented can find potential applications in the field of nanobiotechnology.
Modulated rotating waves and triadic resonances in spherical fluid systems: The case of magnetized spherical Couette flow
Authors: Garcia F. , Giesecke A. , Stefani F.
Published: April 2021

The existence of triadic resonances in the magnetized spherical Couette system is related to the development of modulated rotating waves, which are quasiperiodic flows understood in terms of bifurcation theory in systems with symmetry. In contrast to previous studies in spherical geometry, the resonant modes are not inertial waves but related to the radial jet instability, which is strongly equatorially antisymmetric. We propose a general framework in which triadic resonances are generated through successive Hopf bifurcations from the base state. The study relies on an accurate frequency analysis of different modes of the flow, for solutions belonging to two different bifurcation scenarios. The azimuthal and latitudinal nonlinear coupling among the resonant modes is analyzed and interpreted using spherical harmonics, and the results are compared with previous studies in spherical geometry.
Some remarks on the early history of vibrating Leidenfrost drops
Authors: Stewart Seán M.
Published: April 2021

Leidenfrost drops often exhibit symmetric shape-oscillations when placed onto curved substrates. We give some brief remarks on vibrations found in liquids floating over highly heated surfaces for the overlooked period from the late 1700s up to the work of Holter and Glasscock in 1952 [J. Acoust. Soc. Am. 26, 253 (1952)]; the latter pair were incorrectly credited as the first to observe such behavior in Leidenfrost drops.
Review of Scientific Instruments New Products
Authors: Mandelis Andreas
Published: April 2021

In order to supplement manufacturers’ information, this department will welcome the submission by our readers of brief communications reporting measurements on the physical properties of materials which supersede earlier data or suggest new research applications.
Local controllability and optimality
Authors: Avakov E. R. , Magaril-Il’yaev G. G.
Published: April 2021

The concept of local controllability is introduced for a dynamical system; sufficient conditions for such controllability are presented. As a consequence, necessary conditions for a local infimum in an optimal control problem are obtained. These strengthen Pontryagin’s maximum principle and extend it to more general classes of problems.

Bibliography: 8 titles.
A strengthening of the Bourgain-Kontorovich method: three new theorems
Authors: Kan I. D.
Published: April 2021

Consider the set

of irreducible denominators of the rational numbers representable by finite continued fractions all of whose partial quotients belong to some finite alphabet

. Let the set of infinite continued fractions with partial quotients in this alphabet have Hausdorff dimension

satisfying

. Then

contains a positive share of positive integers. A previous similar result of the author of 2017 was related to the inequality

; in the original 2011 Bourgain-Kontorovich paper,

.

Bibliography: 28 titles.
Continuing the discussion about ecological futures for the lower Murray River (Australia) in the Anthropocene
Authors: Finlayson C. Max , Gell Peter A. , Conallin John
Published: April 2021

The lower Murray River (Australia) has been subject to considerable change from human activities, including the conversion of a variable flow system to one with regulated water levels and the conversion of the estuary to a freshwater system. These conditions will face further pressures owing to reduced flows and higher sea levels associated with climate change. Policy decisions to retain present target conditions could be reconsidered to improve habitat conditions for wetlands, native fish and waterbirds. Contrary to many views, this would be permissible under the Ramsar Convention and, by increasing the diversity of conditions, may assist managers to retain functional systems. This paper encourages a new conversation across the broader community to develop pathways to prepare for emerging pressures on the riverine ecosystems, and move into anthropogenic futures for the Lower Murray.
Reaction intensity partitioning: a new perspective of the National Fire Danger Rating System Energy Release Component
Authors: Fujioka Francis M. , Weise David R. , Chen Shyh-Chin , Kim Seung Hee , Kafatos Menas C.
Published: April 2021

The Rothermel fire spread model provides the scientific basis for the US National Fire Danger Rating System (NFDRS) and several other important fire management applications. This study proposes a new perspective of the model that partitions the reaction intensity function and Energy Release Component (ERC) equations as an alternative that simplifies calculations while providing more insight into the temporal variability of the energy release component of fire danger. We compare the theoretical maximum reaction intensities and corresponding ERCs across 1978, 1988 and 2016 NFDRS fuel models as they are currently computed and as they would be computed under the proposed scheme. The advantages and disadvantages of the new approach are discussed. More study is required to determine its operational implications.
Stress-dependent activation of myosin in the heart requires thin filament activation and thick filament mechanosensing
Authors: Park-Holohan So-Jin , Brunello Elisabetta , Kampourakis Thomas , Rees Martin , Irving Malcolm , Fusi Luca
Published: April 2021

Significance

The efficiency of the heart as a pump depends on an autoregulatory mechanism, the Frank–Starling law of the heart, that potentiates the strength of contraction in response to an increase in ventricular filling. Disruption of this mechanism compromises the ability of the heart to pump blood, potentially leading to heart failure. We used fluorescent probes on myosin in heart muscle cells to investigate the molecular basis of the Frank–Starling mechanism. Our results show that the stronger contraction of heart muscle at longer lengths is due to a calcium-dependent interfilament signaling pathway that links stress sensing in the myosin-containing filaments with calcium activation of the actin-containing filaments. This pathway can potentially be targeted for treating heart failure.
Blighia sapida (akee apple).
Authors: Areces-Berazain Fabiola
Published: April 2021

A datasheet on Blighia sapida covering, as an economically important tree, its taxonomy, importance, silviculture, distribution, biology and ecology, uses, products and pests.
Black holes in asymptotic safety with higher derivatives: accretion and stability analysis
Authors: Zuluaga Fabián H. , Sánchez Luis A.
Published: April 2021

We review steady spherically symmetric accretion onto a renormalization group improved Schwarzschild space-time, which is a solution to an asymptotically safe theory (AS) containing high-derivative terms. We use a Hamiltonian dynamical system approach for the analysis of the accretion of four types of isothermal test fluids: ultra-stiff fluid, ultra-relativistic fluid, radiation fluid, and sub-relativistic fluid. An important outcome of our study is that, contrary to the claim in a recent work, there are physical solutions for the accretion of an ultra-relativistic fluid in AS, which include subsonic, supersonic, and transonic regimes. Furthermore, we study quantum corrections to the known stability of the accretion in general relativity (GR). To this end, we use a perturbative procedure based on the continuity equation with the mass accretion rate being the perturbed quantity. Two classes of perturbations are studied: standing and traveling waves. We find that quantum gravity effects either enhance or diminish the stability of the accretion depending on the type of test fluid and the radial distance to the central object.
Effective field theory approach to lepton number violating τ decays *
Authors: Liao Yi , Ma Xiao-Dong , Wang Hao-Lin
Published: April 2021

We continue our endeavor to investigate lepton number violating (LNV) processes at low energies in the framework of effective field theory (EFT). In this work we study the LNV tau decays

, where

and

denote the lowest-lying charged pseudoscalars

. We analyze the dominant contributions in a series of EFTs from high to low energy scales, namely the standard model EFT (SMEFT), the low-energy EFT (LEFT), and the chiral perturbation theory (

). The decay branching ratios are expressed in terms of the Wilson coefficients of dimension-five and -seven operators in SMEFT and the hadronic low-energy constants. These Wilson coefficients involve the first and second generations of quarks and all generations of leptons; thus, they cannot be explored in low-energy processes such as nuclear neutrinoless double beta decay or LNV kaon decays. Unfortunately, the current experimental upper bounds on the branching ratios are too weak to set useful constraints on these coefficients. Alternatively, if we assume the new physics scale is larger than 1 TeV, the branching ratios are well below the current experimental bounds. We also estimate the hadronic uncertainties incurred in applying

to

decays by computing one-loop chiral logarithms and attempt to improve the convergence of chiral perturbation by employing dispersion relations in the short-distance part of the decay amplitudes.
Improved Qsofa Algorithm Based on PPG Wearable Device
Authors: Liu Yepeng , Yu Xiaoxiao , Luo Xin , Liu Ziyu , He Yu
Published: April 2021

This paper designs an improved Qsofa algorithm based on photoplethysmography measurement technology. The algorithm is mainly used to achieve accurate measurement of the subject’s heart rate and blood pressure and a more refined Qsofa health score. In terms of health data processing, this paper uses a combination of data threshold and mean stabilization algorithms to significantly improve measurement accuracy. In terms of health analysis, this paper greatly reduces the difficulty of the GCS coma evaluation method in the traditional Qsofa algorithm, and at the same time makes the final score of the evaluation more detailed in the same level, so as to more accurately show the health status of the subjects.
Chongqing Transportation Network Simulation and Research Based on Floyd Algorithm
Authors: Long Xin
Published: April 2021

In recent years, research on complex networks is in full swing, and transportation networks are also an important part of the research on complex networks. Since the 21st century, people’s living standards have increased substantially, transportation plays a key role in our lives, and public transportation is an indispensable product of transportation in modern cities, and it greatly facilitates people’s life and travel. This time, the Floyd algorithm is used to improve and apply the complex network, and MATLAB and pajek software are used to simulate, and the empirical research on Chongqing’s bus network is carried out. It is concluded that Chongqing’s bus network has small-world characteristics. With certain help, it can provide reference for the construction plan for relevant people.
An Analysis Method of Ship Traffic Section Flow Based on Big Data
Authors: Yi-fan Liu
Published: April 2021

Traffic flow has important research value for traffic planning and traffic management. In waterway traffic, the cross-sectional flow of ships also has important application value in ship safety management, navigation rule making, bridge and wharf construction, and ship driver decision-making. In order to fully explore the characteristics of ship traffic flow in the big data environment, this paper studies the analysis method of ship cross-section flow based on big data. First of all, in order to ensure the accuracy of calculation and reduce the calculation time to improve calculation efficiency, based on AIS big data optimization data processing method, complete data storage strategy and construction of data management mechanism. Then, the ship section flow analysis algorithm is proposed and implemented. Finally, based on the ship section flow analysis algorithm, a ship section flow analysis and statistics system is constructed to complete the flow calculation and information statistics. The research results of this paper make the relevant analysis of ship traffic flow more convenient and faster, and have greater application value for waterway traffic planning and management.
Numerical Simulation of Axial Pressure Bearing Capacity of Building Concrete Short Column Based on Finite Element Analysis
Authors: Musen Lin
Published: April 2021

Based on the ANSYS finite element platform, considering the geometric parameters and calculation method of the short column Axis material of concrete building, a numerical model of the Axial bearing capacity of concrete building under the finite element analysis is established. On the basis of the model, the load displacement curves of concrete bearing concrete bearing short column Axial pressure under the characteristics of different straps are analyzed, the standard values are set, and the concrete compression strength is set. The concrete conditions and numerical model simulation are established. Feasibility analysis, Through the test results and its specific test content to judge, put forward the test results of the matching method and strategy, give a personal opinion and test description.
Mobile Robot Path Planning Algorithm Based on Improved A Star
Authors: Zhang Lei , Li Yuan
Published: April 2021

With the rapid development of artificial intelligence, path planning has become one of the key technologies in the application of mobile robots. Although the A star(A*)path planning algorithm can plan a collision-free path, there are still shortcomings such as the path is not optimal, too many redundant points, and not smooth enough. Aiming at the deficiencies of the A* algorithm, an improved A* algorithm is proposed. Firstly improved A* algorithm divides the distance between adjacent nodes in the path planned by A* algorithm. Then we use the two-way optimization method to delete useless nodes, short the path length and reduce the number of inflection points. Finally, a cubic spline function is introduce d to smooth the path. The simulation results show that the improved A* algorithm is effectively optimized in terms of path length, number of inflection points and smoothness.
Research on Intelligent Blending Method of Matcha Based on Improved PID Control Algorithm
Authors: Chen Kai , Yu Jie , Hao Miao , Zhang Chengmei , Yang Bing , Tan Hong , Wang Yajie
Published: April 2021

Most of the existing Matcha blending is done manually, which is inefficient and leads to uneven tea products. To solve this problem, this paper proposes an intelligent blending method based on improved PID control algorithm. In this paper, considering the various factors that affect the quality of tea, without affecting the quality of the product, taking the lowest cost of the enterprise as the constraint goal, the basic combination model is constructed by using PID control algorithm. Since the selection of PID parameters will affect the output of the model, this paper introduces particle swarm optimization algorithm to optimize the PID controller parameters globally, so that the PID controller can achieve the ideal control index, and finally determine the optimal combination of Matcha. The experimental results show that the method proposed in this paper can effectively realize the intelligent blending of Matcha, and maximize the cost of tea factory, effectively improve the income of Matcha products, which is conducive to the further development of tea companies.
A comparison between the wrapper and hybrid methods for feature selection on biology Omics datasets
Authors: Guo Chirui , Li Qiuhan
Published: April 2021

Classification problem in biological Omics data has gained in popularity in recent years. In consideration of the high dimension of the Omics dataset, the importance of feature selection technology becomes apparent. Feature selection can not only improve the classification accuracy but also avoid overfitting which is a common issue in machine learning. There are three main categories of feature selection methods: filter methods, wrapper methods, and hybrid methods. Yet it is difficult for researchers to choose among them. In this study, we conducted a comprehensive comparison for filter methods, wrapper methods, and hybrid methods. Specifically, we selected information gain as the filter method, genetic algorithm, and binary particle swarms optimization as the wrapper methods, IG-GA and IG-BPSO as the hybrid methods for comparison. The experimental results show that the IG-BPSO, a hybrid method, has the highest classification accuracy among these feature selection methods on three Omics datasets.
A Deep Learning-Based Hybrid Feature Selection Approach for Cancer Diagnosis
Authors: Wu Haoran
Published: April 2021

Feature selection plays an important role in machine learning-based classification tasks, especially in high dimensional data, such as biological omics datasets. Recent research has begun to explore the use of deep learning to accomplish this task as a step in feature representation. In this research, we developed a deep learning-based hybrid feature selection approach combing Sparse Autoencoder (SAE) and Logistic Regression-Recursive Features Elimination (LR-RFE) and evaluated our method on TCGA miRNA datasets. The results show that our proposed hybrid method achieves a better performance compared to other comparison methods.
Research Photocatalytic Water-splitting based on big data mining technology
Authors: Li Hexi , Chen Gengyun , Xiang Fengshun
Published: April 2021

Visible photocatalytic water splitting is an effective way to solve the global energy and environmental crisis, and its green and environmentally friendly properties are worth researching. In this paper, we extracted 8395 articles from the core collection of Web of Science from 1991 to 2020. Visual analysis of the data by various software, such as Excel, Origin, Citespace V, reflected the following results. First, the number of related papers has increased exponentially, reaching a peak in 2018, with a total of 1508; next, among all countries, China has published the most papers and cooperated most closely with other countries; additionally, in terms of journals, Applied Catalysis B: Environment has the largest number of publications in the field of visible light catalytic cracking of water, and Journal of the American Chemical Society has the highest number of co-citations in this field, researchers can focus on these journals; finally, MAEDA K, ZHANG J, and WANG Y are ideal collaborators in this field. “Application and modification of graphite phase carbon nitride,” “application and modification of Z-scheme photocatalyst,” and “band structure engineering” are the hottest research frontiers in this field and represent the future development direction of this field.
SDAE-based feature selection method for biological Omics data
Authors: Jiang Zhangqi
Published: April 2021

The advancement of Omics technology has led to a surge in molecular and cell profiling data for mechanism study. Large amount of data and complex data structure pose a great challenge to data analysis. Modern machine learning methods such as deep learning are expected to take advantage such big data for accurate disease prediction or other related tasks. However, large feature number may bring large amount redundant information and adversely affect the accuracy of a classifier. To this end, feature selection methods can remove redundant information and help the model achieve higher accuracy by selecting informative features. In this paper, we propose a two-step deep learning-based method combining stacked denoising autoencoders (SDAE) with SVM-RFE to accomplish the task of feature selection. We compared our method with other related methods and the results showed that our approach achieved a better performance than other methods when using the TCGA datasets.
Multi-Scale Context Enhanced Network for Monocular Depth Estimation
Authors: Wang Wenju , Ning Yue
Published: April 2021

Monocular depth estimation is a classical computer vision task. At present, most CNN methods cannot effectively combine high-level and low-level features, leading to the loss of details and blurring of boundaries. To solve the problem, we propose a Multi-Scale Context Enhanced Network (MCEN) to learn more abundant context and expand its receptive field for high-accuracy estimation. Our method employs CRE-HRNet (Context and Receptive Enhanced High-Resolution Network) with four branches ranging from low-dimension to high-dimension features to obtain richer contextual information and extract multi-scale features. It then uses RM (Refinement Module) adopting the residual dilated convolution to retains detailed information and improve the receptive field. Finally, non-local block enables our network to capture the longdistance context through its special non-local operation. Experiments with the NYU Depth V2 dataset show its outstanding performance.
Research on Multi-Angle Face Detection Method Based on Improved YOLOV2 Algorithm
Authors: Zhang Huanping , Cao Hanhua , Liu Zhendan , Zhou Yuhuai , Wang Yujuan
Published: April 2021

Face detection based on the YOLOV2 algorithm can achieve a higher level of accuracy and show a faster detection speed. Therefore, the YOLOV2 algorithm appears more frequently in the field of target real-time detection. The traditional YOLOV2 algorithm uses the Darknet-19 network. Based on this, this paper builds a new network by merging the residual network (ResNet). In addition, in order to further make up for the defects exposed by the YOLOV2 algorithm in face detection, we change the weight of the loss function and implement an image enhancement scheme on the training set. The YOLOV2 algorithm and the improved YOLOV2 algorithm are compared and tested on the Wider Face dataset, and then we use face data sets from different angles to test the performance of the algorithm. According to the analysis of the experimental results, the improved YOLOV2 algorithm can show higher accuracy and robustness in multi-angle face detection.
Application and Optimization of Algorithm Recommendation in Mobile Audio APP
Authors: Zhang Jieyi , Kong Dehua
Published: April 2021

A major feature of mobile audio applications compared with traditional radio stations is that they can enhance the direct connection between users and programs through capturing and analyzing all kinds of data, and make personalized recommendation and accurate transmission to users. Algorithmic recommendation system has different classification, different mobile audio applications based on user positioning and product characteristics, flexible use of a variety of algorithm recommendation methods in the platform. At the same time, the negative effects of algorithm recommendation can not be ignored.
Research on target tracking algorithm based on information entropy feature selection and example weighting
Authors: Bing Huang Chao , Hui Li Ting
Published: April 2021

An improved algorithm based on information entropy feature selection and sample weighting is proposed to solve the drift problem when the multi-instance learning (MIL) target tracking algorithm is updating classifier. Algorithm based on Boosting framework, adopt the method of MIL as sample selection, the positive and negative samples collected around the target area, to extract the image feature is compressed and weak classifier. Based on maximum entropy principle from a number of weak classifier to select several optimal classifier, the resulting strong classifier can be used to track the location of the next frame target. The results show that the algorithm is robust to target occlusion and fast motion.
An improved deep reinforcement learning approach for the dynamic job shop scheduling problem with random job arrivals
Authors: Luo Bin , Wang Sibao , Yang Bo , Yi Lili
Published: April 2021

Deep reinforcement learning (DRL) method is a powerful way to solve the dynamic job shop scheduling problems (DJSSP). However, these DRL approaches are dispatching rules-based, meaning they are problem-specific, dependent on experience, and code effort. We propose a double loop deep Q-network (DLDQN) method with exploration loop and exploitation loop to solve DJSSP under random job arrivals, aiming to minimize the makespans of DJSSP. Simultaneously, by integrating into a single agent scheduling system, the proposed method could avoid complicated dispatching rules, enhancing the proposed method’s versatility. The experiment results have confirmed the superiority of our method compared to other algorithms.
A Multi-angle Improved Small Sample Clustering Algorithm
Authors: Bin Xiao , Chang Liu
Published: April 2021

The random selection of initial clustering centers, outliers, and the differences between attributes will affect the clustering effect of k-means. This article first uses the elbow method to determine the number of categories and then uses the square difference radius method to select the cluster seed center to optimize the cluster center’s reselection. Finally, the entropy method is used to calculate the difference between attributes. The results show that when the number of categories remains the same and abnormal data is added, the improved clustering algorithm from multiple perspectives is more accurate and stable for small sample data with small dimensions and large differences between categories.
A Multi-objective optimized node deployment algorithm for Wireless Sensor Networks Based on the Improved ABC
Authors: Liu Pingshan , Fang Junli , Huang Hongjun
Published: April 2021

In the Internet of Things(IoT) for smart fire applications, sensors are deployed at different places and collect multiple types of data during their work time. Since the coverage of a sensor is limited, how to deploy sensors is important to reduce the number of sensors and improve the quality of wireless sensor networks(WSNs) service. The service quality and network lifetime of wireless sensor networks also are dramatically varied across different coverage and node deployment strategies. There are two crucial problems in WSNs, i.e. node deployment with lowest cost, and coverage optimization with maximum coverage rate, need to be solved. In this research, we focus on the problem of coverage optimization and node deployment. Based on the binary coverage probability model, we develop the joint binary coverage probability model and Improved Artificial Bee Colony(IABC) algorithm. The result of simulation shows that our proposed deployment algorithm have a greater coverage ratio in the case of fewer iterations when the volume of deployed sensors is the same compared with the standard ABC algorithm.