bluuebunny/crossref_metadata_2025_split huggingface dataset:
Minimal theory of massive gravity and constraints on the graviton
mass
Authors: De Felice Antonio , Mukohyama Shinji , Pookkillath Masroor C. 
Published: December 2021

Abstract
The Minimal theory of Massive Gravity (MTMG) is endowed non-linearly
with only two tensor modes in the gravity sector which acquire a non-zero
mass. On a homogeneous and isotropic background the theory is known
to possess two branches: the self-accelerating branch with a phenomenology
in cosmology which, except for the mass of the tensor modes, exactly
matches the one of ΛCDM; and the normal branch which instead
shows deviation from General Relativity in terms of both background
and linear perturbations dynamics. For the latter branch we study
using several early and late times data sets the constraints on today's
value of the graviton mass μ0, finding that (μ0/H
0)2 = 0.119-0.098
+0.12
at 68% CL, which in turn gives an upper bound at 95% CL as μ0 < 8.4 × 10-34 eV. This corresponds to the strongest bound on the mass of the graviton
for the normal branch of MTMG.
Testing Primordial Black Holes
with multi-band observations
of the stochastic gravitational wave background
Authors: Braglia Matteo , García-Bellido Juan , Kuroyanagi Sachiko 
Published: December 2021

Abstract
The mass distribution of Primordial Black Holes (PBHs) is affected by drops in the pressure of the early Universe plasma. For example, events in the standard model of particle physics, such as the W
±/Z
0 decoupling, the quark-hadron transition, the muon and pion becoming non-relativistic, and the annihilation of electrons and positrons, cause a suppression in the Equation of State parameter and leave peaks in the PBH mass function around 10-6, 2, 60, and 106
M
☉, respectively, in the case of a nearly scale-invariant primordial power spectrum. The superposition of unresolved mergers of such PBHs results in a stochastic gravitational-wave background (SGWB) that covers a wide range of frequencies and can be tested with future gravitational wave (GW) detectors. In this paper, we discuss how its spectral shape can be used to infer properties about inflation, the thermal history of the Universe, and the dynamics of binary formation in dense halos encoded in their merger rate formula. Although many of these physical effects are degenerate within the sensitivity of a single detector, they can be disentangled by the simultaneous observation of the SGWB at different frequencies, highlighting the importance of multi-frequency observations of GWs to characterize the physics of PBHs from the early to the late time Universe.
Wavelength-tunable picosecond laser source based on filtering and amplifying broadband dissipative soliton pulse
Authors: Li Jing , Wang Chuncan , Wang Peng , Liu Pengtao , Lan Junhao , Li Hefu 
Published: December 2021

Abstract
A method for obtaining picosecond pulse sources with continuously tunable central wavelengths is demonstrated numerically and experimentally. A dissipative soliton (DS) mode-locked erbium-doped fiber (EDF) laser based on the nonlinear polarization rotation provides the seed pulse with a flat-top spectral profile and a 55 nm spectral bandwidth. Then it is filtered by a wavelength-tunable super-Gaussian bandpass filter and amplified by two segments of EDFs with different doping concentrations. The output DS pulse from the EDF laser can be compressed from 5.532 ps to 0.291 ps by using a single-mode fiber (SMF-28e), while the pulse energy is about 1.6 nJ. Furthermore, the about 4 ps and 6.84 nJ pulses with continuously tunable central wavelengths ranging from 1535 to 1580 nm can be obtained by amplifying the spectrally filtered pulses. The tunable picosecond pulse source based on the extra-cavity filtering method is very useful for many practical applications because of its flexible wavelength control.
Dynamics of GB-speckles with a small number of scatterers
Authors: Ulyanov Sergey , Ulianova Onega , Saltykov Yury , Zaytsev Sergey , Ulyanov Alexander , Feodorova Valentina 
Published: December 2021

Abstract
A method for generating dynamic GB-speckles, formed during diffraction of focused Gaussian beams by moving virtual rough surfaces, obtained for two nucleotide sequences (the ompA genes of the Chlamydia psittaci GR9 and AMK-16 strains), is proposed. The statistical characteristics of the 1st- and 2nd-order statistics of GB-speckles, formed at a small number of scattering events, are studied. The difference in the manifestation of the Doppler effect in the dynamics of GB-speckles and for speckles, formed with a small number of scatterers, produced by light diffraction on physically-existing rough surfaces and in scattering micro-streams is revealed. The problems of interference of dynamic GB-speckles are considered. A new technique for detecting individual single nucleotide polymorphism in nucleotide sequences using the interference of dynamic GB-speckles is proposed.
Chapter 1 LHAASO Instruments and Detector technology *
Authors: Ma Xin-Hua , Bi Yu-Jiang , Cao Zhen , Chen Ming-Jun , Chen Song-Zhan , Cheng Yao-Dong , Gong Guang-Hua , Gu Min-Hao , He Hui-Hai , Hou Chao , Huang Wen-Hao , Huang Xing-Tao , Liu Cheng , Shchegolev Oleg , Sheng Xiang-Dong , Stenkin Yuri , Wu Chao-Yong , Wu Han-Rong , Wu Sha , Xiao Gang , Yao Zhi-Guo , Zhang Shou-Shan , Zhang Yi , Zuo Xiong 
Published: December 2021

Abstract
The Large High Altitude Air Shower Observatory (LHAASO) (Fig. 1) is located at Mt. Haizi (4410 m a.s.l., 600 g/cm2, 29° 21’ 27.56” N, 100° 08’ 19.66” E) in Daocheng, Sichuan province, P.R. China. LHAASO consists of 1.3 km2 array (KM2A) of electromagnetic particle detectors (ED) and muon detectors (MD), a water Cherenkov detector array (WCDA) with a total active area of 78,000 m2, 18 wide field-of-view air Cherenkov telescopes (WFCTA) and a newly proposed electron-neutron detector array (ENDA) covering 10,000 m2. Each detector is synchronized with all the other through a clock synchronization network based on the White Rabbit protocol. The observatory includes an IT center which comprises the data acquisition system and trigger system, the data analysis facility. In this Chapter, all the above-mentioned components of LHAASO as well as infrastructure are described.
Chapter 4 Cosmic-Ray Physics *
Authors: Piazzoli Benedetto D’Ettorre , Liu Si-Ming , Volpe Domenico della , Cao Zhen , Chiavassa Andrea , Piazzoli Benedetto D’Ettorre , Guo Yi-Qing , Ksenofontov Leonid T. , Martineau-Huynh Olivier , Martraire Diane , Ma Ling-Ling , Ma Xin-Hua , Stenkin Yuri , Yuan Qiang , Zeng Hou-Dun , Zhang Shou-Shan , Zhang Yi , Zhu Hui 
Published: December 2021

Abstract
In the first part of this Chapter the present state of knowledge from the observations of cosmic rays between 1013 and 1020 eV is summarized. This is not intended to be a complete review, but rather a broad overview of the relevant processes involving cosmic rays, including the astrophysical environments in which they take place. This overview mainly concerns experimental results and phenomenological aspects of their interpretation, therefore experiments’ description is not given but references to the vast bibliography are provided in the text. Some attempt is made to address the most popular explanations offered by theoretical models. The second part is devoted to the description of the LHAASO performance and of its capability to provide a response to several open questions, still unanswered, concerning cosmic rays above 1013 eV, highlighting which major steps forward in this field could be taken from LHAASO observations.
Study of ion cyclotron range of frequencies heating characteristics in deuterium plasma in the Large Helical Device
Authors: Kamio S. , Saito K. , Seki R. , Kasahara H. , Kanda M. , Nomura G. , Seki T. 
Published: December 2021

Abstract
The characteristics of ion cyclotron range of frequencies (ICRF) minority ion heating with a hydrogen minority and deuterium majority plasma were studied by ICRF modulation injection experiments in the Large Helical Device (LHD). In recent experiments with deuterium plasma, no significant increase in the neutron emission rate due to ICRF second harmonic deuteron heating was observed. Therefore, in this study, the neutron emission rate was used to refer to the information regarding the thermal ion component. Like the results of the observations of the heating efficiencies at various minority proton ratios, the experimental results showed good agreement with the simple model simulation of ICRF wave absorption. During these experiments, the accelerated minority hydrogen ions were observed by neutral particle analyzers. The counting rates of the energetic particles were higher in the lines of sight passing through the helical ripple than across the magnetic axis, and the counting rate decreased as the minority hydrogen ion ratio increased. The dependence of the minority hydrogen ion ratio on the density of the energetic ions was consistent with the experimentally observed heating efficiencies and simulations. The heating efficiency of ICRF minority ion heating could be well explained by simple model simulation in the LHD deuterium experiment.
The influence of temperature and arsenic molecular form at crystallization stage on the InAs nanostructure growth during droplet epitaxy
Authors: Chernenko N E , Balakirev S V , Eremenko M M , Solodovnik M S 
Published: December 2021

Abstract
In this work, experimental studies of the influence of the arsenic molecular form (di-or tetramers) and substrate temperature on the crystallization of In/GaAs droplet nanostructures during droplet epitaxy have been carried out. We have shown the critical influence of the temperature and arsenic molecular form on the reproducibility of the characteristics of an array of self-organizing InAs nanostructures during crystallization. We also showed that a decrease in the initial In droplet size has a positive effect on the reproducibility of the parameters of the InAs nanostructures arrays. Our work also showed important role of substrate temperature at the crystallization stage.
Estimation of thermodynamic stability of isoperiodic epitaxial structures whith GaInSbAs and GaInAsP solid solutions
Authors: Danilina E M , Paschenko A S 
Published: December 2021

Abstract
The work studied the thermodynamic stability of GaInSbAs, GaInAsP heterosystems on different substrates. The isotherms of spinodal decomposition caused by chemical changes in the internal energy of the alloy and by elastic stresses at the layer-substrate interface are obtained with the model of quasiregular solutions. It has been found that elastic stresses lead to an expansion of the region of thermodynamic stability of isoperiodic solid solutions for GaSb substrates and a decrease in the critical temperature. The developed model can be using to selection of the technological modes and parameters of epitaxial growth.
Study of In/GaAs nanodroplet formation in conditions of non-stationary supersaturation during droplet epitaxy
Authors: Dukhan D D , Balakirev S V , Chernenko N E , Eremenko M M , Solodovnik M S 
Published: December 2021

Abstract
In this paper, we present the results of kinetic Monte Carlo study of the In/GaAs growth by droplet epitaxy in conditions of non-stationary vapor supersaturation. These conditions allow achievement of the independent control of size and surface density of nanostructures. The material redistribution is realized on the surface when indium deposition is interrupted and leads to a decrease in the critical thickness of droplet formation. An average droplet size increases with increase in interruption time whereas the surface density decreases. However, additional nucleation within the wetting layer can also be observed during the growth interruptions, which makes it possible to increase the surface density of droplets.
Elastic properties of porous silicon layer of hybrid SiC/Si substrates
Authors: Eremeev I A , Koryakin A A , Kukushkin S A 
Published: December 2021

Abstract
Elastic properties of porous silicon layer of hybrid SiC/Si substrates grown by the atomic substitution method are investigated. The feature of the growth method is the formation of the macroporous silicon layer at the SiC/Si interface during growth. The elastic properties of the layer are studied using the finite element method. The biaxial modulus of the porous silicon is obtained as a function of porosity considering the different shape of the pores and presence of thin SiC boundary layer. The presence of the pores in the silicon layer adjacent to SiC results in the decrease of the elastic moduli by about 35%. However, this leads to a negligibly small change of the substrate curvature.
Method for the modification of graphite subsurface layer to a solid mixture of SiC and graphite
Authors: Grashchenko A S , Kukushkin S A , Osipov A V , Redkov A V 
Published: December 2021

Abstract
We studied the interaction of molten Si and graphite surface during annealing in different atmospheres (CO, vacuum, Ar). The studies have shown that during annealing in CO atmosphere a composite material of SiC and graphite in a thick subsurface layer of the graphite is being formed, whereas at vacuum and Ar atmosphere the modified layer is either thin or absent. The composition and structure of both the composite material itself and the interface between the composite material and the graphite matrix were investigated using the methods of scanning electron microscopy and Raman spectroscopy. Studies have shown that the composite material obtained by this method has a branched fibrous structure consisting of small tubular layers of silicon carbide interspersed with large monocrystalline grains of silicon carbide of the cubic polytype, which leads to significant strengthening of the material. Thus the proposed method can be used to form a thermal protective, chemically resistant coating on graphite surface.
Effect of Yb3+doping level on the structure and spectroscopic properties of ZnO optical ceramics
Authors: Gorokhova E , Venevtsev I , Alekseeva I , Khubetsov A , Dymshits O , Basyrova L , Oreschenko E , Eron’ko S , Muktepavela F , Kundzins K. , Zhilin A , Loiko P 
Published: December 2021

AbstractZinc oxide optical ceramics with hexagonal structure doped with 0.6 –5.0 wt% Yb were fabricated by uniaxial hot pressing of commercial oxide powders at 1180 °C in vacuum. The ceramics were characterized by X-ray diffraction, SEM, EDX, X-ray and optical spectroscopy. It is shown that Yb3+ions are distributed between C-type Yb2O3sesquioxide crystals and ZnO grain boundaries. The Yb3+doping of ZnO ceramics enhances the near-band-edge emission of zinc oxide. ZnO:Yb optical ceramics are promising for optoelectronic applications.
Quantitative analysis of metastable wurtzite phase into the self-catalyzed GaP NWs
Authors: Koval O Yu , Fedorov V V , Eliseev I E , Bolshakov A D , Kirilenko D A , Burkovsky R G , Mukhin I S 
Published: December 2021

Abstract
In this letter, we report the growth of the self-catalyzed GaP nanowires with a high concentration of wurtzite phase by molecular beam epitaxy. Formation of rotational twins and wurtzite polymorph in vertical nanowires was observed by the developed a complex approach based on the transmission electron microscopy and X-ray diffraction method. Microstructural analysis performed by high resolution transmission electron microscopy and micro-Raman spectroscopy gives us insights on the nanowire formation mechanism and vibrational properties of nanowires with mixed crystal phase. We obtained wurtzite polytype segments with thicknesses lying in the range from several tens up to 500 nm. The results of the work open new perspectives for high phase purity phosphide NWs synthesis and its fast investigation with XRD technique using a laboratory X-Ray source.
Nanostructured electrodes for supercapacitors
Authors: Yavtushenko I O , Makhmud-Akhunov M Yu , Adamovich A A 
Published: December 2021

Abstract
The paper presents the results of studies on the formation of planar capacitive systems based on nanoporous anodic oxide films and a conducting polymer. According to voltammetry data, the capacity of the systems under study was determined. The structure of the porous layers was judged by impedance spectroscopy and electron microscopy.
Study of nonlinear optical phenomena in silicon nanowires
Authors: Mastalieva V A , Neplokh V , Morozov A I , Nikolaeva A A , Gudovskikh A S , Mukhin I S , Makarov S V 
Published: December 2021

Abstract
This work studies generation of second and third harmonics in arrays of vertically oriented silicon nanowires (SiNWs) encapsulated into a silicone membrane and separated from the growth substrate. The structures were produced by plasma-chemical etching of silicon substrate resulting in a formation of homogeneous arrays of SiNWs. Such SiNW-based membranes demonstrated efficient infrared-to-visible light conversion by generation of second and third harmonic signals visible by a naked eye. This study contributes to the development of technology of optical devices based on silicon and presents a new route for visualization of infrared radiation.
Laser-induced optical nonlinearity in a Li-rich glass
Authors: Moroz A Yu , Babich E S , Kaasik V P , Lipovskii A A , Melekhin V G , Redkov A V , Tagantsev D K 
Published: December 2021

Abstract
The selective crystallization of a photosensibilized lithium silicate glass after a light emitting diode (280 nm) and a nanosecond laser (355 nm) UV irradiation and subsequent heat treatment was studied. Using a focused beam of the laser allows successive drawing regions in which the formation of silver nanoparticles after 500°C heat treatment of the glass co-doped with silver and cerium ions takes place. It is shown that this treatment is a necessary step for the growth of sodium metasilicate crystals under the second thermal treatment of the glass at 600 °C, while these regions demonstrate second optical harmonic generation of 1064 nm nanosecond laser radiation.
The influence of the surface density of oriented nickel networks on the conducting electrode’s optical transparency
Authors: Nizameev I R , Nizameeva G R , Kadirov M K 
Published: December 2021

Abstract
This study is part of the work on the creation of a transparent conductive coating based on oriented nanonetwork and submicron nickel fibres. It is devoted to finding the optimal values of electrical conductivity and optical transparency of the developed coating. In this work, we study the transmission spectra of oriented nickel networks on a glass substrate in the UV, visible and near-IR regions at different amounts of deposited metal. An exciting feature of the coating was discovered: in the range of 950 nm and above, there is a "bend" of the transmission spectrum downward. This bend (increased absorption of radiation in the near-IR region) is observed only in the presence of nickel nanonetwork and is not typical for a pure submicron network.
Conformality of a-Si:H deposited by low temperature PECVD for solar cells application
Authors: Uvarov A V , Baranov A I , Morozov I A , Kudryashov D A , Maksimova A A , Vyacheslavova E A , Gudovskikh A S 
Published: December 2021

Abstract
This work is devoted to the study of the deposition of a-Si:H by the PECVD method in continuous and pulsed regime on test structures in the form of trenches with a high aspect ratio. The thicknesses of the layers obtained in these modes were investigated by the method of scanning electron microscopy. It was shown that the layers obtained in the pulsed mode, as compared with the continuous one, have better conformity.
Double slot aerosol jet printed antenna for X-band applications
Authors: Arsenov P V , Sobolev A S , Efimov A A , Ivanov V V 
Published: December 2021

Abstract
A double slot antenna for X-band applications was designed and aerosol jet printing technology was used to fabricate the prototype with silver nano-ink on a flexible polyimide substrate. We investigated the microwave losses of printed antennas in the range from 100 kHz to 27 GHz, obtained at sintering temperatures of 200 °C and 250 °C. Double slot X-band antennas have been calculated and measured. It was found that an operating bandwidth of the printed antenna is 10% in the region of the central frequency of 10.5 GHz. Thus, the possibility of forming antennas on flexible polymer substrates with high functional characteristics by aerosol jet printing method has been demonstrated.
Terahertz detector utilizing a SiO2/Graphene/SiO2 sandwich suspended at the feed of a planar antenna
Authors: Belikov I , Rybin M , Prikhodko A , Mikhailov D , Gayduchenko I , Shurakov A , Goltsman G 
Published: December 2021

Abstract
We report on the fabrication of a terahertz detector utilizing a SiO2/graphene/SiO2 sandwich suspended at the planar antenna feed. This design of the detector aims to enhance its sensitivity via weakening of the heat sink between graphene’s phonons and those of the substrate. We achieve complete suspension of the sandwich only in case of a low fill-factor of the antenna feed area. Evaluated DC parameters of the samples are consistent with those reported in the literature. The fabrication process developed is suitable for implementing the detector proposed for signal frequencies up to several terahertz.
Analysis of the possibility of creating an acoustic velocity sensor using GaN epitaxial films
Authors: Enns Y , Kazakin A , Akulshin Y , Mizerov A , Kleimanov R 
Published: December 2021

Abstract
This paper results in results of analyzing the possibility of creating an acoustic velocity sensor using epitaxial GaN films. Technology for the fabrication of a microelectromechanical acoustic velocity sensor was developed and a prototype of the sensor was produced. The simulation of the characteristics of the obtained acoustic velocity sensors was carried out on the basis of the measured electrical characteristics, where the sensitivity and the directional pattern were determined.
Features of the formation of the frequency of the microwave excitation signal in the quantum frequency standard on rubidium atoms - 87
Authors: Grevtseva A S , Dmitriev R A , Davydov V V , Rud V Yu 
Published: December 2021

Abstract
The article discusses the main disadvantages of the current design of a quantum frequency standard based on rubidium-87 atoms. The main disadvantages of the current design of the quantum frequency standard on rubidium-87 atoms are considered. It is noted that the processes associated with light shifts in the optical part contribute to the greatest instability in the long-term operation of the quantum frequency standard. A solution is proposed to improve the design of the rubidium standard. A forecast for improving its metrological characteristics is presented. The results of experimental investigations are presented.
Development of a fiber-optic microwave signal transmissionsystem for an X-band receiving module with dual frequencyconversion
Authors: Moroz A V , Davydov V V , Gubareva D V , Rud’ V Yu 
Published: December 2021

Abstract
The article discusses the use of double frequency conversion in the receiving module of the radar. To solve the resulting interference in the feeder paths, it is proposed to use a fiber- optic transmission system. The results of experimental investigations are presented.
Silicon carbide of 4H-SiC type Schottky diode current-voltage characteristics in small-sized type metal-polymeric package SOT-89
Authors: Sedykh S V , Rybalka S B , Demidov A A , Kulchenkov E A 
Published: December 2021

Abstract
The forward and reverse current–voltage characteristics of Ti/Al/4H-SiC Schottky diode type DDSH411A91 in modern small-sized (SOT-89) type metal-polymeric package have been obtained. In forward direction (current up to 2 A) on the basis of analysis it is shown that Schottky diode corresponds to the "ideal" diode with ideality factor n=1.12 and effective Schottky barrier height φB
=1.2 eV. It is shown that reverse current-voltage characteristics (breakdown voltage 1200 V) can be well approximated by mechanism of field dependence of barrier height lowering by the presence of the intermediate layer in the form of oxide on the 4H-SiC surface.