bluuebunny/crossref_metadata_2025 huggingface dataset:
Graphene-nanoplatelets-supported NiFe-MOF: high-efficiency and ultra-stable oxygen electrodes for sustained alkaline anion exchange membrane water electrolysis
Authors: Thangavel Pandiarajan , Ha Miran , Kumaraguru Shanmugasundaram , Meena Abhishek , Singh Aditya Narayan , Harzandi Ahmad M. , Kim Kwang S.
Published: May 2020

A simple and effective strategy for fabricating high-stability alkaline anion exchange membrane water electrolyzers for large-scale hydrogen production.
A full battery system of pre-lithiated phosphorus/sulfurized pyrolyzed poly(acrylonitrile) with an effective electrolyte and improved safety
Authors: Han Xinpeng , Wang Xiaojun , Han Muyao , Sun Jie
Published: May 2020

A new and green Li3P-S battery was built and delivered a high capacity retention of 97.1% after 600 cycles.
Copper catalyzedN-formylation of α-silyl-substituted tertiaryN-alkylamines by air
Authors: Zhao Yichao , Bruce Lachlan David , Jin Jianwen , Xia Bo , Chan Philip Wai Hong
Published: May 2020

A site-selective synthetic method to prepareN-formyl amines efficiently from copper(i)-catalyzed oxidation of α-silylamines by air at room temperature is presented.
Peroxidase-like behavior and photothermal effect of chitosan-coated Prussian-blue nanoparticles: dual-modality antibacterial action with enhanced bioaffinity
Authors: Chakraborty Nayanika , Jha Diksha , Gautam Hemant K. , Roy Indrajit
Published: May 2020

Mechanism of peroxidase-like activity and photothermal effect of chitosan-coated Prussian blue nanoparticles.
Development of a metalloproteomic approach to analyse the response of Arabidopsis cells to uranium stress
Authors: Sarthou Manon C M , Revel Benoît H , Villiers Florent , Alban Claude , Bonnot Titouan , Gigarel Océane , Boisson Anne-Marie , Ravanel Stéphane , Bourguignon Jacques
Published: May 2020

Uranium is a naturally occurring radionuclide that is absorbed by plants and interferes with many aspects of their physiology and development. In this study, we used an ionomic, metalloproteomic, and biochemical approach to gain insights into the impact of uranyl ions on the proteome of Arabidopsis thaliana cells. First, we showed that most of the U was trapped in the cell wall and only a small amount of the radionuclide was found in the cell-soluble fraction. Also, the homeostasis of several essential elements was significantly modified in the cells challenged with U. Second, the soluble proteome from Arabidopsis cells was fractionated into 10 subproteomes using anion-exchange chromatography. Proteomic analyses identified 3676 proteins in the different subproteomes and the metal-binding proteins were profiled using inductively coupled plasma mass spectrometry. Uranium was detected in several chromatographic fractions, indicating for the first time that several pools of Arabidopsis proteins are capable of binding the uranyl ion in vivo. Third, we showed that the pattern of some lysine and arginine methylated proteins was modified following exposure to U. We further identified that the ribosomal protein RPS10C was dimethylated at two arginine residues in response to uranyl ion stress. Together, these results provide the first clues for the impact of U on the Arabidopsis proteome and pave the way for the future identification of U-binding proteins.
Proton conduction in two hydrogen-bonded supramolecular lanthanide complexes
Authors: Shi Zhi-Qiang , Ji Ning-Ning , Chen Wan-Yao , Li Gang
Published: May 2020

Two hydrogen-bonded supramolecular lanthanide complexes based on imidazole dicarboxylate show different proton conductivities.
Disulphide-mediated site-directed modification of proteins
Authors: Nielsen Thorbjørn , Märcher Anders , Drobňáková Zuzana , Hučko Michal , Štengl Milan , Balšánek Vojtěch , Wiberg Charlotte , Nielsen Per F. , Nielsen Thomas E. , Gothelf Kurt V. , Cló Emiliano
Published: May 2020

Site-directed addition of a single thiols handle to proteins by means of temporary disulphide rebridging of solvent exposed disulphides is obtained with a new labelling reagent.
Patterned nanofiber air filters with high optical transparency, robust mechanical strength, and effective PM2.5 capture capability
Authors: Cao Jinshan , Cheng Zhiqiang , Kang Lijuan , Lin Meng , Han Lihao
Published: May 2020

PM2.5, due to its small particle size, strong activity, ease of the attachment of toxic substances and long residence time in the atmosphere, has a great impact on human health and daily production.
Highly efficient removal of Cu(ii) by novel dendritic polyamine–pyridine-grafted chitosan beads from complicated salty and acidic wastewaters
Authors: Wang Li-Li , Ling Chen , Li Bang-Sen , Zhang Da-Shuai , Li Chen , Zhang Xiao-Peng , Shi Zai-Feng
Published: May 2020

Dendritic polyamine chitosan (CNP) beads containing 2-aminomethyl pyridine were facilely prepared for the efficient removal of Cu(ii) ions from highly acidic and salty solutions.
A stable and highly sensitive room-temperature liquefied petroleum gas sensor based on nano-cubes/cuboids of zinc antimonate
Authors: Singh Satyendra , Singh Archana , Singh Ajendra , Tandon Poonam
Published: May 2020

A new direction was explored using nanostructured zinc antimonate as a stable and highly sensitive LPG sensing material.
Anthracene derivatives as broadband nonlinear optical materials: nonlinear absorption and excited-state dynamics analysis
Authors: Zhou Wenfa , Fang Yu , Wu Xingzhi , Han Yanbing , Yang Junyi , Shen Lei , Song Yinglin
Published: May 2020

Expanding the π-bridge to adjust the molecular planarity via increasing the amount of ethylene can modulate the nonlinear optical response.
Synthesis of Schiff and Mannich bases of news-triazole derivatives and their potential applications for removal of heavy metals from aqueous solution and as antimicrobial agents
Authors: Hozien Zeinab A. , EL-Mahdy Ahmed F. M. , Abo Markeb Ahmad , Ali Laila S. A. , El-Sherief Hassan A. H.
Published: May 2020

An efficient synthesis of Schiff and Mannich bases of news-triazole derivatives under mild conditions has been developed for the removal of Pb2+, Cd2+, Ca2+, and Mg2+from aqueous solutions and as antimicrobial agents.
A quick and versatile one step metal–organic chemical deposition method for supported Pt and Pt-alloy catalysts
Authors: Jackson Colleen , Smith Graham T. , Mpofu Nobuhle , Dawson Jack M. S. , Khoza Thulile , September Caelin , Taylor Susan M. , Inwood David W. , Leach Andrew S. , Kramer Denis , Russell Andrea E. , Kucernak Anthony R. J. , Levecque Pieter B. J.
Published: May 2020

A simple, modified Metal–Organic Chemical Deposition (MOCD) method for Pt, PtRu and PtCo nanoparticle deposition onto a variety of support materials, including C, SiC, B4C, LaB6, TiB2, TiN and a ceramic/carbon nanofiber, is described.
A physical approach for the estimation of the SERS enhancement factor through the enrichment and separation of target molecules using magnetic adsorbents
Authors: Zhao Danhui , Lin Kui , Wang Lanhui , Qiu Zhigang , Zhao Xin , Du Kunze , Han Lifeng , Tian Fei , Chang Yanxu
Published: May 2020

The controllable synthesis of nanosized Fe3O4 (10–20 nm) encapsulated in different numbers of graphene layers (1–5 layers) (Fe3O4@DGL NPs) was realized through a facile and green hydrothermal reaction at a temperature as low as 200 °C.
Peat-derived hard carbon electrodes with superior capacity for sodium-ion batteries
Authors: Adamson Anu , Väli Ronald , Paalo Maarja , Aruväli Jaan , Koppel Miriam , Palm Rasmus , Härk Eneli , Nerut Jaak , Romann Tavo , Lust Enn , Jänes Alar
Published: May 2020

A synthesis method has been developed to turn peat, cheap biomass into hard carbons that demonstrate high capacity and excellent sodium storage capability as anode material in sodium-ion batteries.
Influence of liquid bridge formation process on its stability in nonparallel plates
Authors: Bian Xiongheng , Huang Haibo , Chen Liguo
Published: May 2020

The effect of liquid bridge formation process on its stability was discussed to obtain the theoretical equation for determining the stability of the liquid bridge.
New synthetic procedure for the antiviral sulfonate carbosilane dendrimer G2-S16 and its fluorescein-labelled derivative for biological studies
Authors: Gutiérrez-Ulloa Carlos , Peña-González Cornelia E. , Barrios-Gumiel Andrea , Ceña-Díez Rafael , Serramía-Lobera M. Jesús , Muñoz-Fernández M. Ángeles , Javier de la Mata F. , Sánchez-Nieves Javier , Gómez Rafael
Published: May 2020

Ethenesulfonyl fluoride (ESF) is a useful reagent to prepare sulfonate carbosilane dendrimers with antiviral properties and labelled dendrimers for biological studies.
Site-selective, catalytic, and diastereoselective sp3C–H hydroxylation and alkoxylation of vicinally functionalized lactams
Authors: Beng Timothy K. , Shearer Victoria , Davey Rachel , Redman Ivianne
Published: May 2020

Catalytic, diastereoselective, and site-selective sp3C–H hydroxylation and alkoxylation protocols featuring lactams that bear vicinal stereocenters, is described.
Low temperature conversion of levulinic acid into γ-valerolactone using Zn to generate hydrogen from water and nickel catalysts supported on sepiolite
Authors: García Adrián , Sanchis Rut , Miguel Pablo J. , Dejoz Ana M. , Pico María Pilar , López María Luisa , Álvarez-Serrano Inmaculada , García Tomás , Solsona Benjamín
Published: May 2020

Levulinic acid transformation into γ-valerolactone at 30 °C in water without molecular hydrogen addition.
Nature as a treasure trove of potential anti-SARS-CoV drug leads: a structural/mechanistic rationale
Authors: Sayed Ahmed M. , Khattab Amira R. , AboulMagd Asmaa M. , Hassan Hossam M. , Rateb Mostafa E. , Zaid Hala , Abdelmohsen Usama Ramadan
Published: May 2020

Potential drug candidates derived from natural sources are posed for the development of anti-SARS CoV-2 therapeutics.
Sc3N@Ih-C80 based donor–acceptor conjugate: role of thiophene spacer in promoting ultrafast excited state charge separation
Authors: Caballero Rubén , Servián Luis David , Gobeze Habtom B. , Fernandez-Delgado Olivia , Echegoyen Luis , D'Souza Francis , Langa Fernando
Published: May 2020

Photoinduced charge separation and dark charge recombination occurring within picoseconds is observed in newly synthesized triphenylamine–thiophene-Sc3N@Ih-C80 and triphenylamine–thiophene-C60 conjugates.
SMolESY: an efficient and quantitative alternative to on-instrument macromolecular 1H-NMR signal suppression
Authors: Takis Panteleimon G. , Jiménez Beatriz , Sands Caroline J. , Chekmeneva Elena , Lewis Matthew R.
Published: May 2020

Small Molecule Enhancement SpectroscopY (SMolESY) by computational suppression of 1H-NMR macromolecular signals: a functional replacement for on-instrument spin-echo experiments.
Mobility and versatility of the liquid bismuth promoter in the working iron catalysts for light olefin synthesis from syngas
Authors: Gu Bang , Peron Deizi V. , Barrios Alan J. , Bahri Mounib , Ersen Ovidiu , Vorokhta Mykhailo , Šmíd Břetislav , Banerjee Dipanjan , Virginie Mirella , Marceau Eric , Wojcieszak Robert , Ordomsky Vitaly V. , Khodakov Andrei Y.
Published: May 2020

Localization and migration of highly mobile and extremely efficient bismuth promoter in iron Fischer–Tropsch catalysts were elucidated using in situ methods.
Thermodynamically driven self-formation of copper-embedded nitrogen-doped carbon nanofiber catalysts for a cascade electroreduction of carbon dioxide to ethylene
Authors: Lee Jae-Chan , Kim Ji-Yong , Joo Won-Hyo , Hong Deokgi , Oh Sang-Ho , Kim Beomil , Lee Gun-Do , Kim Miyoung , Oh Jihun , Joo Young-Chang
Published: May 2020

Cu acetate/PAN nanofibers were transformed into porous C nanofibers with doped N and Cu particles,viaO2partial pressure-controlled calcination. N atoms next to Cu trigger the CO2RR by increasing the amount of CO* on the Cu, lowering the energy needed for CO dimerization.
Biological applications of water-soluble polypeptides with ordered secondary structures
Authors: Ge Chenglong , Ye Huan , Wu Fan , Zhu Junliang , Song Ziyuan , Liu Yong , Yin Lichen
Published: May 2020

Herein, recent advances in the synthesis of the water-soluble polypeptides with ordered secondary structures via ring-opening polymerization of NCA/NTA and their biological applications are described.
Influence of fluorination on electronic states and electron transport properties of Sr2IrO4 thin films
Authors: Maruyama Takahiro , Chikamatsu Akira , Katayama Tsukasa , Kuramochi Kenta , Ogino Hiraku , Kitamura Miho , Horiba Koji , Kumigashira Hiroshi , Hasegawa Tetsuya
Published: May 2020

We fabricated layered-perovskite Sr2IrO4−xF2x thin films by combining pulsed-laser deposition with topotactic fluorination and investigated the modulation of their electronic states and electron transport properties.
Adrenomedullin regulated by miRNA-574-3p protects premature infants with bronchopulmonary dysplasia
Authors: Gong Xiaohui , Qiu Jiajun , Qiu Gang , Cai Cheng
Published: May 2020

Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease (CLD) in premature infants. The present study was designed to elucidate the regulation of miRNA-547-3p on adrenomedullin (ADM) during the pathogenesis of BPD. We used Agilent Human 4x44K Gene Expression Microarrays v2 and miRCURY LNA™ microRNA Array to identify the differently expressed miRNA and its potential target genes, and certified them again by luciferase reporter gene analysis. We only retained target genes that met the following two conditions: first, coexisting in two databases, and second, expressing differences, and then identifying target genes by luciferase reporter gene analysis. Thus, we selected miRNA-574-3p and its target gene ADM for further research. We used real-time q-PCR to determine the expression of miRNA-574-3p and its target gene ADM in premature infants with BPD. We used microarray expression to analyze BPD samples and non-BPD samples and found that there were 516 differently expressed probes between them. The 516 differently expressed probes included 408 up-regulated probes and 108 down-regulated probes. The blood samples of BPD infants were detected by real-time q-PCR and found that the expression of miRNA-574-3p was decreased, while the expression of ADM was significantly increased. Luciferase reporter gene analysis showed that hsa-miR-574-3p can regulate the expression of luciferase with ADM 3′UTR, and decrease it by 61.84%. It has been reported in the literature that ADM can protect the premature infants with BPD. The target gene ADM of miRNA-574-3p may contribute to the prevention and treatment of BPD.
The serum angiotensin-converting enzyme 2 and angiotensin-(1-7) concentrations after optimal therapy for acute decompensated heart failure with reduced ejection fraction
Authors: Hisatake Shinji , Kiuchi Shunsuke , Kabuki Takayuki , Oka Takashi , Dobashi Shintaro , Fujii Takahiro , Ikeda Takanori
Published: May 2020

Objective: Elucidation of the role of angiotensin-converting enzyme (ACE) 2 (ACE2)/angiotensin (Ang)-(1-7)/Mas receptor axis in heart failure is necessary. No previous study has reported serial changes in ACE2 and Ang-(1-7) concentrations after optimal therapy (OT) in acute heart failure (AHF) patients. We aimed to investigate serial changes in serum ACE2 and Ang-(1-7) concentrations after OT in AHF patients with reduced ejection fraction (EF).

Methods: ACE2 and Ang-(1-7) concentrations were measured in 68 AHF patients with reduced EF immediately after admission and 1 and 3 months after OT. These parameters were compared with the healthy individuals at three time points.

Results: In the acute phase, Ang-(1-7) and ACE2 concentrations was statistically significantly lower and higher in AHF patients than the healthy individuals (2.40 ± 1.11 vs. 3.1 ± 1.1 ng/ml, P<0.005 and 7.45 ± 3.13 vs. 4.84 ± 2.25 ng/ml, P<0.005), respectively. At 1 month after OT, Ang-(1-7) concentration remained lower in AHF patients than the healthy individuals (2.37 ± 1.63 vs. 3.1 ± 1.1 ng/ml, P<0.05); however, there was no statistically significant difference in ACE2 concentration between AHF patients and the healthy individuals. At 3 months after OT, there were no statistically significant differences in Ang-(1-7) and ACE2 concentrations between AHF patients and the healthy individuals.

Conclusion: ACE2 concentration was equivalent between AHF patients and the healthy individuals at 1 and 3 months after OT, and Ang-(1-7) concentration was equivalent at 3 months after OT.
Design of an advanced soft‐output Viterbi algorithm detector for bit‐patterned media recording systems
Authors: Nguyen Chi Dinh
Published: May 2020

An advanced soft‐output Viterbi algorithm detector aided by extrinsic information resources is proposed for bit‐patterned media recording (BPMR) systems. These BPMR systems offer significant advantages over conventional magnetic recording systems. However, the performance system is significantly affected by a two‐dimensional interference. The proposed method improves the channel detection output under the assistance of a variety of extrinsic information sources. Especially, combining the proposed model with an adaptive scheme for extrinsic information to enhance system performance is examined. Furthermore, evaluating the worth of extrinsic information in the different signal‐to‐noise ratio (SNR) conditions is also considered in this work. The results show that the SNR gains from the proposed model are about 4 dB compared to conventional solutions at non‐misregistration.
Synchronised ambient data‐driven electromechanical oscillation modes extraction for interconnected power systems using the output‐only observer/Kalman filter identification method
Authors: Wang Lixin , Yang Deyou , Cai Guowei , Ma Jin , Tian Jie , Wang Bo
Published: May 2020

Ambient‐based oscillation modes extraction is an effective means of monitoring the small signal stability of a power system on‐line. In this study, a data‐driven approach based on output‐only observer/Kalman filter identification (O3KID) combined with the eigensystem realisation algorithm (ERA) was proposed to extract electromechanical modes (frequency, damping ratio and mode shape) from synchronised ambient data. As a key for extracting a reduced‐order state matrix using the ERA, the Markov parameters (impulse responses) are first estimated by employing O3KID on multi‐channel ambient data. O3KID makes it possible to identify the modes with the ERA using only output ambient data, while ensuring the reliability of the extractions of frequencies, damping ratios and mode shapes. The performance of the proposed method was evaluated by employing the IEEE 16‐generator 5‐area system and measured data from a real power system. The estimation results in all cases as well as comparison results with the RDT‐ERA method and NExT‐ERA method indicate that the O3KID‐ERA method is a promising method for ambient data‐driven electromechanical oscillation modes extraction.
Starting point selection approach for power system model validation using event playback
Authors: Akhlaghi Shahrokh , Zhou Ning , Chiang Hsiao‐Dong
Published: May 2020

Model validation is an essential task to determine whether a model can accurately describe the actual behaviours of a power system. Currently, major commercial software tools are equipped with an ‘event playback’ function to validate dynamic models using testing data from phasor measurement units (PMUs). Due to their limited bandwidth and low sampling rates, PMUs cannot capture the fast‐transient dynamics. As such, the playback function using the conventional approach may mistakenly invalidate an accurate model during the high‐frequency responses. To overcome the deficiency, a batch state estimation approach is proposed in this study to improve the performance of the ‘event playback’ function by focusing on low‐frequency responses in model validation. The proposed approach consists of three major steps. First, a multi‐model adaptive Kalman filter approach is used to estimate the dynamic states of the system. Second, the singular spectrum analysis (SSA) is used to detect the fault clearance time. Finally, the estimated states after the fault are used as the initial states of the ‘event playback’ to validate the dynamic model during the low‐frequency responses. The analytical basis of the proposed method is also provided by showing the existence and uniqueness of the trajectory of the underlying model. The effectiveness of the proposed approach is demonstrated using the PSS/E.
Modelling large vehicles operating speed characteristics on freeway alignment based on aggregated GPS data
Authors: Hou Wei , Lyu Nengchao , Liu Zhaoxin , Wang Xu
Published: May 2020

Operating speed is a basic measure for studying the safety of freeways. However, whether the designed speed matches the actual operating speed of large vehicles is worth studying. As such, this study included a large number of aggregated vehicle global positioning system (GPS) datasets used to analyse the actual speed of large vehicles under different alignment conditions on the freeway; and supplement the theoretical operating speed model. Using the traditional operating speed prediction model, the theoretical speed of each section was calculated. Two months of vehicle GPS data from freeways was extracted from a vehicle monitoring platform, the actual operating speed of each section was obtained. The similarities and differences between the theoretical operating speed and the actual vehicle speed on the horizontal and vertical curves were analysed and compared. The results indicate that the actual speed of large vehicles was obviously higher than the theoretical speed operating downhill. When the vehicle was operating uphill, the vehicle's actual speed was significantly lower than that of the theoretical speed. The actual vehicle operating speed data can be used as a new method for evaluating the safety of large vehicles on the freeway.
Parameter identification of a lithium‐ion battery based on the improved recursive least square algorithm
Authors: Ren Biying , Xie Chenxue , Sun Xiangdong , Zhang Qi , Yan Dan
Published: May 2020

Accurate parameter identification of a lithium‐ion battery is a critical basis in the battery management systems. Based on the analysis of the second‐order RC equivalent circuit model, the parameter identification process using the recursive least squares (RLS) algorithm is discussed firstly. The reason for the RLS algorithm affecting the accuracy and rapidity of model parameter identification is pointed out. And an improved RLS algorithm is proposed, an inner loop with the estimated parameter vector updated multiple times is inserted into the conventional RLS algorithm, so that the identification results are improved. The test platform of a single lithium‐ion battery is built. The experimental results show that the improved RLS algorithm has better tracking ability, smaller prediction error and has a moderate computational burden compared with the conventional RLS algorithm and a variable forgetting factor RLS algorithm.
Novel MTDC droop scheme with decoupled power control for enhancing frequency stabilities of weak AC systems
Authors: Li Yujun , Liu Sining , Zhu Jiebei , Yuan Xiaotian , Xu Zhao , Jia Ke
Published: May 2020

Traditional way to enable frequency support provided by MTDC system for the connected weak AC systems is to modify the power reference of each converter under standard power‐sharing droop control based on the weak grid's frequency deviations. However, this scheme artificially couples all asynchronous AC systems to tackle with the frequency disturbances of any connected AC systems, which might result in broader frequency disturbance propagations. To overcome this, this study proposes a decoupled frequency control (DFC) scheme to improve weak AC systems frequency stabilities. First, the relationship between the active power and power set points of each converter is derived by the linearization of MTDC power flow equations. Then, the frequency coupling properties of each AC system with traditional frequency control are derived, and it shows that the frequency disturbance will be propagated to all the connected AC systems with traditional control. Furthermore, the control law of each converter in the proposed DFC is developed through the defined decoupled matrix, and the independent frequency regulation characteristic of each converter can be obtained. Finally, numerical simulations have demonstrated the effectiveness of the proposed DFC scheme in events of load changes and converter loss in the main and weak AC grid.
Construction of knowledge graph of maritime dangerous goods based on IMDG code
Authors: Zhang Qi , Wen Yuan Q , Han Dong , Zhang Fan , Xiao Chang S
Published: May 2020

The International Maritime Dangerous Goods Code (IMDG Code) is the most important regulation in the international maritime transport chain of dangerous goods. Any international ship carrying dangerous goods must be strictly observed. Integrating and correlating cumbersome knowledge of IMDG Code and simplifying the query process are of great significance to the safe transportation and storage of dangerous goods. As a new method of knowledge representation and management, knowledge graph has been successfully applied in many industries. It can present the complex relationship between domain knowledge and correlate trivial and scattered knowledge, which provides a new way to solve this problem. This article starts with the knowledge system, structure, and classification of IMDG Code, and then analyses the related concepts of knowledge graph of maritime dangerous goods. Based on the above analysis, the authors construct the knowledge graph of maritime dangerous goods. It is helpful to simplify the retrieval process of dangerous goods professional knowledge, realise the automatic judgment of cargo stowage and segregation, and promote the intelligent transportation of dangerous goods.
Understanding the rotational variability of K2 targets
Authors: Krtička J. , Kawka A. , Mikulášek Z. , Fossati L. , Krtičková I. , Prvák M. , Janík J. , Skarka M. , Liptaj R.
Published: May 2020

Context. Ultraprecise space photometry enables us to reveal light variability even in stars that were previously deemed constant. A large group of such stars show variations that may be rotationally modulated. This type of light variability is of special interest because it provides precise estimates of rotational rates.

Aims. We aim to understand the origin of the light variability of K2 targets that show signatures of rotational modulation.

Methods. We used phase-resolved medium-resolution X-shooter spectroscopy to understand the light variability of the stars KIC 250152017 and KIC 249660366, which are possibly rotationally modulated. We determined the atmospheric parameters at individual phases and tested the presence of the rotational modulation in the spectra.

Results. KIC 250152017 is a HgMn star, whose light variability is caused by the inhomogeneous surface distribution of manganese and iron. It is only the second HgMn star whose light variability is well understood. KIC 249660366 is a He-weak, high-velocity horizontal branch star with overabundances of silicon and argon. The light variability of this star is likely caused by a reflection effect in this post-common envelope binary.
La tour Eiffel : le premier laboratoire d’aérodynamique en France
Authors: Wesfreid José Eduardo
Published: May 2020

Cet article décrit sommairement la recherche expérimentale de Gustave Eiffel, qui a mis en évidence la forte réduction de la trainée d’une sphère dans un écoulement à grande vitesse, accompagnant le changement occasionné par la transition de la couche limite du corps depuis l’état laminaire vers l’état turbulent (crise de trainée).

Cette découverte, mise en question initialement par Ludwig Prandtl, a été rendue possible par la conception et la réalisation par Eiffel d’un ensemble de nouvelles expériences astucieuses et de techniques innovantes créées autour de la tour Eiffel.

Un siècle après la découverte de cet effet, la compréhension de la dynamique de transition turbulente intermittente et bistable ainsi que la description des structures cohérentes instables présentes dans cette transition, restent ouvertes.
A vascular-liver chip for sensitive detection of nutraceutical metabolites from human pluripotent stem cell derivatives
Authors: Yu Fang , Goh Yeek Teck , Li Huan , Chakrapani Narmada Balakrishnan , Ni Ming , Xu Guo Lin , Hsieh Tseng-Ming , Toh Yi-Chin , Cheung Christine , Iliescu Ciprian , Yu Hanry
Published: May 2020

Human pluripotent stem cell (hPSC) is a great resource for generating cell derivatives for drug efficiency testing. Metabolites of nutraceuticals can exert anti-inflammatory effects on blood vessels. However, the concentration of nutraceutical metabolites produced in hPSC-derived hepatocytes (hPSC-HEPs) is usually low. To enable the detection of these metabolites under the in vitro environment, we have developed a co-culture model consisting of parallel co-culture chambers and a recirculating microfluidic system with minimum fluid volume, optimal cell culture environment. The model allows cells to be exposed continuously to nutraceutical metabolites. In this perfused culturing model, hPSC-derived endothelial cells and hPSC-HEPs are co-cultured without physical contact. When an anti-inflammatory nutraceutical, quercetin, was administrated to the co-culture, higher levels of quercetin metabolites were detected on-chip compared with static control. We further induced inflammation with Interleukin-1β in the co-culture model and measured interleukin 8 (IL-8) generation. The IL-8 level was suppressed more significantly by quercetin metabolites in the perfusion co-culture, as compared to static culture. This is due to enhanced metabolites production on-chip. This microfluidic co-culture model enables in vitro screening of nutraceuticals using hPSC-derived cells.
Generalized Vaidya solutions in bimetric gravity
Authors: Högås Marcus , Kocic Mikica , Torsello Francesco , Mörtsell Edvard
Published: May 2020

In general relativity, the endpoint of spherically symmetric gravitational collapse is a Schwarzschild–[(A)dS] black hole. In bimetric gravity, it has been speculated that a static end state must also be Schwarzschild–[(A)dS]. To this end, we present a set of exact solutions, including collapsing massless dust particles. For these, the speculation is confirmed.
Demonstration of the universality of molecular structures in prolate deformed nuclei
Authors: Canavan R , Freer M
Published: May 2020

The relationship between the deformed harmonic oscillator and the formation of molecular cluster structures, whereby valence neutrons are exchanged between cluster cores, is examined. It is found that there is a strong connection between the properties of the valence orbitals associated with deformed structures in the deformed harmonic oscillator and the molecular orbitals created by linear combinations of single-centre orbitals around nuclear clusters. The conclusion is that in addition to the appearance of clustering in the deformed harmonic oscillator that every prolate deformed cluster structure should have molecular orbitals built on that structure. This is demonstrated through a series of examples that range from 13C to 57Ni.
Thermodynamic-temperature data from 30 K to 200 K
Authors: Gaiser Christof , Fellmuth Bernd , Haft Norbert
Published: May 2020

New measurements of thermodynamic temperature T with Dielectric-Constant Gas Thermometry (DCGT) were performed at PTB from 50 K to 200 K. Particular care was taken to check for possible systematic sources of errors by performing experiments applying three working gases, namely helium, neon, and argon, the polarizability of which differs by a factor of up to eight. Together with former DCGT values of thermodynamic temperature the new results yield a consistent dataset in the range from 30 K to 200 K. This dataset is in good agreement with the newest results of Acoustic Gas Thermometry (AGT) and Refractive-Index Gas Thermometry (RIGT), which have quite different sources of uncertainty compared with DCGT. The combination of these DCGT, AGT, and RIGT data with the ‘Estimates of the differences between thermodynamic temperature and the ITS-90’, being as an appendix of the ‘Mise en pratique for the definition of the kelvin in the SI’ the present-day recommendation of the Consultative Committee for Thermometry, yields a new function T − T
90 versus ITS-90 temperature T
90 for the range from 35 K to 195 K, the uncertainty of which is reduced by a factor up to about four.
Algorithm for the formation of a linguistic integrated assessment of resource sustainability of an enterprise
Authors: Azarnova T V , Asnina N G , Bondarenko Yu V , Barkalov S A
Published: May 2020

The paper proposes an algorithm for the formation of a linguistic integrated assessment of the resource sustainability of an enterprise, based on the theory of extensive and intensive use of resources and methods of aggregating linguistic information using linguistic ordinal operators that formalize sequential averaging strategies for multicriteria estimation. The assessment of the extent of extensive and intensive use of resources in the work is carried out through groups of models that re ect the dependence of the resulting indicators of the enterprise on the quantity and quality of resources of various types. Quantitative indicators of the intensity of resource use are estimated by the method of chain substitutions; the Harrington function is used to switch to linguistic values. The integrated linguistic assessment obtained as a result of the work of the considered algorithm aggregates the linguistic values of the resource use intensity by all models and is interpreted as an integral indicator of resource stability, which is achieved due to intensive production factors.
Synthesis and scalarization of hierarchical vector criterion in production management problems
Authors: Sizikov A
Published: May 2020

The multicriteriality problem has many aspects. The paper is dedicated to one of them, namely: development of the methodology for building and using dynamically changing multi-level vector criteria for optimization of engineering and manufacturing complexes. The approach applied most frequently involves vector to scalar conversion of the optimization criterion. When multi-level criteria are used we have to deal with a system of embedded convolutions forming a hierarchical system of vectors. The current principles of making convolutions for such systems can be implemented in different ways depending on peculiarities of the controlled object and management goalsThis study discusses building of hierarchical criteria in mathematical setting up of engineering and manufacturing complex optimization problems. A method of forming and scalarization of a hierarchical vector criterion following a recurrent procedure based on an invariant representing a linear combination of Holder norms of partial criteria is suggested. An example of techniques usage in the development of software for multi-criterial optimization of refinery is given.
On the influence of linear blowing and constant temperature factor on the values of functionals of hypersonic aerodynamics
Authors: Bilchenko G G , Bilchenko N G
Published: May 2020

The problems of mathematical modeling of effective control of heat and mass transfer and friction on permeable cylindrical and spherical surfaces of hypersonic aircraft are considered. The systems of ordinary differential equations are obtained by A.A.Dorodnicyn generalized integral relations method to approximate the systems of partial differential equations describing laminar boundary layers on permeable cylindrical and spherical surfaces of hypersonic aircraft. The joint systems are applied in the mathematical model. The parameters of the mathematical model at the flow stagnation point are determined from the joint systems of nonlinear algebraic equations. The blowing into boundary layer, temperature factor and magnetic field are used as controls. Dependences of hypersonic aerodynamics functionals (the total heat flow, the total Newton friction force and total blowing system power) on controls (the linear blowing into boundary layer, the constant temperature factor, the constant magnetic field) are investigated. The domains of allowed values of functionals of hypersonic aerodynamics are obtained. The results of the computational experiments are presented: the dependences of total heat flow on controls; the dependences of total Newton friction force on controls; the dependences of blowing system power on controls; the mutual dependences of functionals (as the domains of allowed values “Heat and Friction”).
On the influence of linear temperature factor and constant blowing on the values of functionals of hypersonic aerodynamics
Authors: Bilchenko G G , Bilchenko N G
Published: May 2020

The problems of mathematical modeling of effective control of heat and mass transfer and friction on permeable cylindrical and spherical surfaces of hypersonic aircraft are considered. The systems of ordinary differential equations are obtained by A.A.Dorodnicyn generalized integral relations method to approximate the systems of partial differential equations describing laminar boundary layers on permeable cylindrical and spherical surfaces of hypersonic aircraft. The joint systems are applied in the mathematical model. The parameters of the mathematical model at the flow stagnation point are determined from the joint systems of nonlinear algebraic equations. The blowing into boundary layer, temperature factor and magnetic field are used as controls. Dependences of hypersonic aerodynamics functionals (the total heat flow, the total Newton friction force and total blowing system power) on controls (the constant blowing into boundary layer, the linear temperature factor, the constant magnetic field) are investigated. The domains of allowed values of functionals of hypersonic aerodynamics are obtained. The results of the computational experiments are presented: the dependences of total heat flow on controls; the dependences of total Newton friction force on controls; the dependences of blowing system power on controls; the mutual dependences of functionals (as the domains of allowed values “Heat and Friction”).
Stages and procedures for forming a method to assess reliability of the information security systems in automated systems and main areas of its implementation in the normative-technical documentation
Authors: Bokova O I , Bulgakov O M , Etepnev A S , Rogozin E A
Published: May 2020

The article completes the cycle the articles by the authors assessing reliability of information security systems from the unauthorized access to automated systems. In includes previously unpublished materials. The article discloses main directions to improve methods and procedures for assessing reliability of the information security systems from the unauthorized access to automated systems. There is modification of the traditional static method to assess the functional reliability of the information security systems from the unauthorized access to investigate their operation in the dynamic (real) functioning mode and to quantify reliability of the information security systems, including development of adequate indicators, models and algorithms. Main stages and procedures for forming the reliability assessment method were developed as a technological scheme with demonstration of the main stages to implement the proposed methods in the current normative-technical documentation.
Graphs with table constraints on reachability
Authors: Erusalimskiy I M , Pevneva K L
Published: May 2020

On directed graphs defined a new kind of reachability restriction – table constraints on reachability. Each edge of the graph assigned a certain element of the monoid. Some element of the monoid selected and fixed. This element does not equal to the unit of the monoid. This element is called forbidden. Each way on the graph is associated with characteristic – a vector, whose length is equal to the number of way edges. First element of the characteristic is equal to the element of the monoid which corresponded to the first edge of the way. Each successive element of the characteristic is equal to the previous element of the characteristics plus the value of an element of the monoid, corresponding to the next edge of the way. A way on the graph is considered as valid if the way characteristic does not contain a forbidden element. The construction of the scan-graph, which is built on the original graph, is described. The transition to the scan-graph allows you to solve the problems of the reachability on such graphs, shortest ways and random walks on the graphs with table constraints on reachability.
Formalization of the optimality criteria based on fuzzy predicates
Authors: Ledeneva T , Kaplieva N
Published: May 2020

The paper considers logical approach to solution of multi-objective optimization problems, which consists in representing a certain optimality principle in the form of a predicate with subsequent generalization in the form of a membership function of a fuzzy set of optimal solutions. The results of the study of the dependence of the optimal solution of the fuzzy multi-objective problem on the principle of optimality, functional representation and parameters of fuzzy logical connectives are presented.
Planar projection of the principal components of fractal Brownian functions
Authors: Moskalev Pavel V , Fedulova Lyudmila I , Gridneva Irina V
Published: May 2020

The error in the planar projection of the principal components of a multidimensional data array strongly depends on the number and dimension of the column vectors of this array and the correlation between the vectors. In this work, we investigate the dependence of the error on the planar projection of the principal components of fractal Brownian functions on the number of statistically independent realizations in the multidimensional data array. As a result, we show that, under certain assumptions, the number of statistically independent realizations of fractal Brownian functions coincides with the effective dimension of the projection of the principal components.
On the Huygens principle in the Puu model
Authors: Polovinkina Marina V , Polovinkin Igor P , Rabeeakh Svetlana A
Published: May 2020

We consider the macroeconomic model of T. Puu, describing the fluctuations of gross income in a given region. With a special combination of savings and investment rates, income deviations will take place only for a finite period of time, after which the income will return to a stationary state. This e˙ect is known in mathematical physics as the Huygens principle. We investigated this model using statistical methods of data analysis. The obtained results suggest that the Huygens effect hypothesis in certain historical periods of the Russian economy is plausible. We have also considered the structure of the set of stationary zeros for nontrivial solutions to a stationary equation.
Machine learning based TOF charged particle identification at BM@N detector of NICA collider
Authors: Roudnev V A , Merts SP , Nemnyugin S A , Stepanova M M
Published: May 2020

In the article results of charged particles identification for BM@N experiment being performed at NICA acceleration complex of Joint Institute for Nuclear Research are presented. A standard neural network-based technique of constructing a classificator is applied to the data sets obtained both from modelling of a realistic experimental setup and three synthetic data sets. The carried-out analysis demonstrates that the estimated data accuracy is insufficient to make a clear distinction between electrons, muons and pions, and also between -particles and deutrons. The problem could be solved by using an extra data from the detector or by improving the accuracy of the experimental data by two orders of magnitude.
On the growth speed of own values for the fourth order spectral problem with Radon–Nikodim derivatives
Authors: Shabrov Sergey A , Ilina Ol’ga M , Shaina Ekaterina A , Chechin Dmitrii A
Published: May 2020

In the present paper, the growth rate of eigenvalues for the fourth-order spectral problem with nonsmooth solutions is obtained. It arises when we apply the Fourier method to the mathematical model, describing small free vibrations of a mechanical system consisting of pivotally connected rods. We assume that at the connection points there are springs that respond to rotation, while the system is in the external environment with localized features, leading to a loss of smoothness of the solution. The analysis of the problem is based on the pointwise approach proposed by Yu. V. Pokorny, and proved to be effective in studying linear boundary problems of the second and fourth orders with continuous solutions (an exact parallel with oscilation theory of ordinary differential equations is constructed).
Formalization of scientific and technical sentences in Russian language
Authors: Vishniakov Y , Vishniakov R
Published: May 2020

The article presents the research results on the computational theory of semantic interpretation in Russian language. These interpretations represent a generalizing formalization of a scientific and technical style sentences. Furthermore, the concept of a partition system of a word scale, its classes and a method of forming partition classes is defined. We showed that the word scale corresponds to many partition systems that are specified by a special rule for selecting instances from classes. Additionally, we proposed generalized algorithms for constructing a partition system.
Graphostructural modeling of discrete-argument systems
Authors: Blyumin S L , Yu Zhbanova N , Sysoev A S
Published: May 2020

Graphostructural modeling is an effective tool for the analysis and control of social and economics systems. Graphs, hypergraphs and metagraphs are used to simulate complex hierarchical structures. In this paper we consider metagraphs and their matrices associated with 2D and 3D systems and cellular automatons; and their relationship with the transition from basic to associated models of cellular automatons. The transition to an associated model is a key step in developing the theory of discrete argument systems. In this paper with the simple examples of discrete-argument systems we demonstrate that matrix characteristics of the models, associated with such systems, are closely related to the matrix characteristics of associated metagraphs.
Mathematical modeling of uranium and hydrocarbons recovery operations
Authors: Galtsev O V
Published: May 2020

The development of uranium and hydrocarbon deposits is a rather complex technological process consisting of several related sub-processes. One of them is the dissolution of solid soil by acid (in-situ leaching). The aim of this article is to model this process at the macroscopic level. The approach is based on the detailed consideration of fundamental laws of mechanics and chemistry at the pore scale. It is clear that the mathematical model obtained at the pore scale cannot be used in practical applications, but its simple and mathematically correct form allows further approximation by a system of homogenized equations. The dynamics of the liquid and the concentration of the reagent is described by a system of Darcy equations and the convection-diffusion equation respectively, obtained by homogenization the initial microscopic problem at the pore level. To solve the system of equations numerically, the method of finite differences on a uniformly spaced staggered grid is used. Temporal and spatial discretization of the equations is carried out. The results of numerical experiments are presented. The obtained results can help to analyse the active solution front motion in a porous medium and physical and chemical processes there.
Development of algorithm for analysis of sound fragments in medical information systems
Authors: Abramov G , Korobova L , Matytsina I
Published: May 2020

The article is devoted to the recognition of sound signals, including cough jerks, using various mathematical methods. The paper presents an information system for the diagnosis of patients with pulmonary diseases. The main problem of this system is to determine the parameters of cough fragments in the monitoring record recorded with a dictaphone. Criteria of recognition of cough moments are given, the analysis of processing of sound record is carried out and results of research are systematized. This system can be used by doctors to diagnose the condition of patients, as well as to monitor the treatment process.