Hengzongshu/ArticleAgent huggingface dataset:
The possibility of experimental simulation of supersonic jets expansion from spacecraft nozzles on compact experimental installations with a comparatively low capacity of vacuum pumping systems is considered. The experience of the Novosibirsk State University on the use of various variants of simulation of gas-dynamic jets is expounded.

Examples of measurements of supersonic jets that flow from supersonic nozzles to vacuum and into a highly rarefied medium are presented. The results of spectral luminescence measurements excited by a focused electron beam, longitudinal and transverse density profiles of jets using modern scanning techniques, as well as photographic images of jets using a modulated electron beam technique are considered.

The possibilities and peculiarities of each registration method are discussed.
We consider a conflict-free minimum latency data aggregation problem that occurs in different wireless networks. Given a network that is presented as an undirected graph with one selected vertex (a sink), the goal is to find a spanning aggregation tree rooted in the sink and to define a conflict-free aggregation minimum length schedule along the arcs of the tree directed to the sink. Herewith, at the same time slot, each element of the network can either send or receive at most one message. Only one message should be sent by each network element during the whole aggregation session, and the conflicts caused by signal interference should be excluded. This problem is NP-hard and remains NP-hard even in the case when the aggregation tree is given. Therefore, the development of efficient approximation algorithms is very important for this problem. In this paper, we present new heuristic algorithms based on genetic local search and variable neighbourhood search metaheuristics. We conducted an extensive simulation that demonstrates the superiority of our algorithms compared with the best of the previous approaches.
Formic acid decomposition to H2-rich gas was investigated over a CuO-CeO2/γ-Al2O3 catalyst. The catalyst was characterized by XRD, HR TEM and EDX methods. A 100% conversion of formic acid was observed over the copper-ceria catalyst under ambient pressure, at 200–300 °C, N2:HCOOH = 75:25 vol.% and flow rate 3500–35,000 h−1 with H2 yield of 98%, wherein outlet CO concentration is below the equilibrium data (<0.5 vol.%). The copper-ceria catalyst proved to be promising for multifuel processor application, and the H2 generation from dimethoxymethane, methanol, dimethyl ether and formic acid on the same catalyst for fuel cell supply.
The paper presents the results of sensitivity-based identifiability analysis of the COVID-19 pandemic spread models in the Novosibirsk region using the systems of differential equations and mass balance law.

The algorithm is built on the sensitivity matrix analysis using the methods of differential and linear algebra. It allows one to determine the parameters that are the least and most sensitive to data changes to build a regularization for solving an identification problem of the most accurate pandemic spread scenarios in the region. In our study, the problems of parameter identification using additional information about the number of daily confirmed, critical and mortality cases in the region were reduced to minimizing the corresponding misfit functions. The minimization problem was solved through the differential evolution method that is widely applied for stochastic global optimization.

The performed analysis has demonstrated that the virus contagiousness is identifiable from the number of daily confirmed, critical and recovery cases. On the other hand, the predicted proportion of the admitted patients who require a ventilator and the mortality rate are determined much less consistently. It has been shown that building a more realistic forecast requires adding additional information about the process such as the number of daily hospital admissions. It has been demonstrated that a more general COVID-19 spread compartmental model consisting of seven ordinary differential equations describes the main trend of the spread and is sensitive to the peaks of confirmed cases but does not qualitatively describe small statistical datasets such as the number of daily critical cases or mortality that can lead to errors in forecasting. A more detailed agent-oriented model has been able to capture statistical data with additional noise to build scenarios of COVID-19 spread in the region.
The dynamics of the process $ e^+e^- \to \pi^+\pi^-\pi^0 $ is studied in the energy region from 1.15 to 2.00 GeV using data accumulated with the SND detector at the VEPP-2000 $e^+e^-$ collider.

The Dalitz plot distribution and $\pi^+\pi^-$ mass spectrum are analyzed in a model including the intermediate states $\rho(770)\pi$, $\rho(1450)\pi$, and $\omega\pi^0$.

As a result, the energy dependences of the $\rho(770)\pi$ and $\rho(1450)\pi$ cross sections and the relative phases between the $\rho(770)\pi$ amplitude and the $\rho(1450)\pi $ and $\omega\pi^0$ amplitudes are obtained. The $\rho(1450)\pi$ cross section has a peak in the energy region of the $\omega(1650)$ resonance (1.55-1.75 GeV). In this energy range the contributions of the $\rho(770)\pi$ and $\rho(1450)\pi$ states are of the same order of magnitude. No resonance structure near 1.65 GeV is observed in the $\rho(770)\pi$ cross section. We conclude that the intermediate state $\rho(1450)\pi$ gives a significant contribution to the decay of $\omega (1650)\to\pi^+\pi^-\pi^0$, whereas the $\rho(770)\pi$ mechanism dominates in the decay $\omega(1420)\to\pi^+\pi^-\pi^0$.
The results of the study of collection oat samples of various ecological and geographical origin are presented. The experiments were carried out in Novosibirsk region in 1994-2018. The sources that combine the optimal density of the productive plant stand and the mass of grain from the panicle were identified according to the ripeness groups. There were 413 collection samples of spring oats studied from 42 countries of the world for 25 years. Collection varieties were evaluated in nurseries of the 2nd-3d year of study. To identify the best samples, a scoring evaluation system of the traits under consideration, i.e. the density of the productive plant stand and the mass of grain from the panicle, was used. Comparison of genotypes for these traits was carried out within a group of varieties with an equal score for the duration of the seedlings -wax ripeness period. The standard varieties Krasnoobsky and Rovesnik were studied for all 25 years, therefore, all years were divided into three groups according to the average biological yield of these varieties. The first group includes 5 years, in which the standard varieties formed a low yield - less than 300 g/m 2 . The second group includes 14 years with a standard yield of 300-600 g/m 2 . The third group includes 5 years with the most favorable conditions for the formation of a high biological yield - more than 600 g/m 2 . A significant correlation between biological productivity and panicle productivity was noted in the standard variety Krasnoobsky during the years with a medium yield and in the standard variety Rovesnik during the years with a high yield. With the traits being evaluated in points, biological productivity showed a strong positive correlation with panicle productivity in Krasnoobsky variety in all groups of years, and in Rovesnik variety only in groups of years with medium and high yield. The sources of biological productivity of oats were identified by ripeness groups: very early - VIR-14522 (Dukat, Poland); early-ripening - VIR-14223 (Ardo KR-FPTS, Czechoslovakia); mid-early - VIR-15340 (Uran, Omsk region), VIR-14729 (SG-K-93682, the Czech Republic), VIR-14588 (Gramena, Germany), VIR-14582 (Carl Theodor, Germany), VIR-15012 (Togurchanin, Tomsk region), VIR-14706 (Keeper, Great Britain), VIR-14581 (Borka, Germany), VIR-15178 (Begunok, Ulyanovsk region) and Novosibirsky 5 (Novosibirsk region); mid-ripening - VIR-14377 (Mutika 572, Omsk region), VIR-14520 (Kwant, Poland), VIR-15254 (AC Mustang, Canada), VIR-15280 (55h 2106, Moscow region) and VIR-14527 (OM 1385, Great Britain); medium-late - VIR-15065 (Irtysh 22, Omsk region), VIR-14860 (Malysh, Tyumen region) and VIR-15103 (R8N9 3037-3072, Krasnoyarsk region).
The power scaling on all-fiberized Raman fiber oscillator with brightness enhancement (BE) based on multimode graded-index (GRIN) fiber is demonstrated. Thanks to beam cleanup of GRIN fiber itself and single-mode selection properties of the fiber Bragg gratings inscribed in the center of GRIN fiber, the efficient BE is realized. For the laser cavity with single OC FBG, continuous-wave power of 334 W with an M 2 value of 2.8 and BE value of 5.6 were obtained at a wavelength of 1120 nm with an optical-to-optical efficiency of 49.6%. Furthermore, the cavity reflectivity is increased by employing two OC FBGs to scale the output power up to 443 W, while the corresponding M 2 is 3.5 with BE of 4.2. To our best knowledge, it is the highest power in Raman oscillator based on GRIN fiber.
In full and over load operating points some Francis turbines experience strong selfexcited pressure and power oscillations, which restrict the range of operation and maximum output of the turbine. Previously the authors proposed a 1D-3D two-phase model and numerical method for investigation of this phenomenon. In the present paper this model is further extended and applied to investigation of countermeasures, used for prevention of high load oscillations. First, the third phase - non-condensable air - is introduced into the model in order to investigate the effect of air admission. Then, several modifications of runner cone are examined, showing negligible effect on the amplitude and frequency of full load oscillations. Next, different modifications of runner blade shape are considered, giving different axial and circumferential velocity profiles downstream the runner. It is shown that variation of blade shape significantly affects the onset and intensity of self-excited oscillations. The obtained results indicate that proper runner design is able to eliminate high load instability without the need of air admission and reduction in turbine efficiency.
According to the results of a comprehensive sedimentological study of the core and well log data, the dissection of the bat-upper Jurassic sediments of the South of the West Siberian oil and gas basin was carried out.

Quasi-isochronous marked levels are identified. They are represented by transgressive surfaces, maximum flooding surfaces and extended carbonaceous layers. They are the basis of the performed correlation.

A number of characteristic lithological-facies sequences diagnosed by well log data was established.
The effects of asynchrony in the phenology of spring-feeding insect-defoliators and their host plants on insects’ fitness, as well as the importance of this effect for the population dynamics of outbreaking species of insects, is a widespread and well-documented phenomenon. However, the spreading of this phenomenon through the food chain, and especially those mechanisms operating this spreading, are still unclear.

In this paper, we study the effect of seasonally declined leafquality (estimated in terms of phenolics and nitrogen content) on herbivore fitness, immune parameters and resistance against pathogen by using the silver birch Betula pendula—gypsy moth Lymantria dispar—nucleopolyhedrovirus as the tritrophic system.

We show that a phenological mismatch induced by the delay in the emergence of gypsy moth larvae and following feeding on mature leaves has negative effects on the female pupal weight, on the rate of larval development and on the activity of phenoloxidase in the plasma of haemolymph. In addition, the larval susceptibility to exogenous nucleopolyhydrovirus infection as well as covert virus activation were both enhanced due to the phenological mismatch. The observed effects of phenological mismatch on insect-baculovirus interaction may partially explain the strong and fast fluctuations in the population dynamics of the gypsy moth that is often observed in the studied part of the defoliator area. This study also reveals some indirect mechanisms of effect related to host plant quality, which operate through the insect innate immune status and affect resistance to both exogenous and endogenous virus.
The Mongol–Okhotsk Belt, the youngest segment of the Central Asian Orogenic Belt, formed by the evolution and closure of the Mongol–Okhotsk Ocean. The oceanic closure formed two volcanoplutonic belts: Selenge Belt in the north and Middle Gobi Belt in the south (in present day coordinates). However, the origin and tectonic evolution of the Mongol–Okhotsk Belt in general, the origin and formation age of the Middle Gobi Belt in particular, remain enigmatic.

To better understand the history of the magmatic activity in the Middle Gobi Belt, we conducted geochemical, U–Pb geochronological, zircon Hf, whole-rock Nd isotopic analyses of volcanic and plutonic rocks of the Mandalgovi suite, the major component of the Middle Gobi Belt. Our results show that the Mandalgovi suite consists of (i) 265 ± 2 Ma biotite-granite; (ii) 250 ± 3 Ma hornblende-granitoids; (iii) their volcanic equivalents of both: and (iv) gabbro-diorites. The geochemical compositions indicate that their precursor magmas were derived from crustal source. The protoliths of the biotite and hornblende-granitoids were metagraywacke and metabasalt, respectively. They are characterized by positive whole-rock εNd(t) and zircon εHf(t) values, indicating the molten protoliths were juvenile crust.

The biotite-granites formed by remelting of fore-arc sediments by ridge subduction and later hornblende-granites were emplaced at an intra-oceanic arc by the subduction of the Mongol–Okhotsk Ocean. We conclude that the magmatic rocks of the Middle Gobi formed in an active continental margin and/or intra-oceanic arc setting.
The article discusses the trends and prospects of development of the three sectors of rural entrepreneurship: corporate, individual and family, formal and informal; analyze the transformation of household farms; an assessment of efficiency of development of small forms of agricultural production, it is concluded that the major agricultural organizations lost their dominant position.
A discrete model is constructed for calculating the Lame equation with complex boundary conditions. The model is tested on an analytical solution. A complex boundary condition arises when a microcrack is specified on one of the boundaries. Calculation of microcracks will enable better assessment of the relevance of the simulation and finding out which mechanisms will occur in the case of plasma flow heating in modern plasma and future thermonuclear installations.
Currently, approximately 3000 species of stick insects are known; however, chromosome numbers, which range between 21 and 88, are known for only a few of these insects. Also, centromere banding staining (C-banding) patterns were described for fewer than 10 species, and fluorescence in situ hybridization (FISH) was applied exclusively in two Leptynia species. Interestingly, 10-25% of stick insects (Phasmatodea) are obligatory or facultative parthenogenetic. As clonal and/or bisexual reproduction can affect chromosomal evolution, stick insect karyotypes need to be studied more intensely. Chromosome preparation from embryos of five Phasmatodea species (Medauroidea extradentata, Sungaya inexpectata, Sipyloidea sipylus, Phaenopharos khaoyaiensis, and Peruphasma schultei) from four families were studied here by C-banding and FISH applying ribosomal deoxyribonucleic acid (rDNA) and telomeric repeat probes. For three species, data on chromosome numbers and structure were obtained here for the first time, i.e., S. inexpectata, P. khaoyaiensis, and P. schultei. Large C-positive regions enriched with rDNA were identified in all five studied, distantly related species. Some of these C-positive blocks were enriched for telomeric repeats, as well. Chromosomal evolution of stick insects is characterized by variations in chromosome numbers as well as transposition and amplification of repetitive DNA sequences. Here, the first steps were made towards identification of individual chromosomes in Phasmatodea.
The question: human evolution- gradual process or a rapid discontinuous change? Whether human origin was a gradual process or a result of rapid change has been a focus of intense debate. Of particular interest is the climate change ~2.9-2.5 Ma, thought to have precipitated the separation of the genus Homo (~2.8Ma). The debate mostly concerned continuity/punctuality of the fossil record, but of course the rate of the underlying genetic change is of ultimate interest/importance. Did hominid lineage experience an increased mutation rate when a large number of hominins emerged and eventually gave rise to the split between Australopitecus/Paranthropus and Homo ? The obstacle: vague timing of conventional mutations . The difficulty in answering the above question lies in the way past mutations are timed. Conventional point mutations are assigned to specific branches of the DNA-derived phylogenetic trees. The essence of the problem is that mutations can be located within branch segments from branching point to branching point, but the exact position within the segment is principally unknown. Because the hominid DNA-derived phylogenetic tree is rather sparsely populated with branches, the precision of mutation timing is low, e.g., human-specific mutations can be positioned within ~6 My from separation from chimpanzee. The solution: NUMTs – mutations with an internal clock . NUMTs are insertions of mtDNA sequences into the nuclear genome. Unlike point mutation, each NUMTs actually represents a branch on the mtDNA phylogenic tree and thus its time of insertion can be determined as precise as their branching point can be positioned on the tree. In a sense, NUMTs are “mutations with an internal clock”, which is synchronized with the well-established mtDNA mutation evolution clock. By determining the NUMTs’ insertion time points, one can ask whether whether NUMTs were inserted at a constant rate over time or at increased rate during critical periods of evolution, according with the “punctuated evolution” model. Results : Hundreds of pseudogenes have been inserted into the human genome over the last ~60 My of which we considered the last 6 My. Various quality filters resulted in the selection of 18 NUMTs most suitable for phylogenetic analysis. Insertion times of these 18 NUMTs cluster around 2.8Ma. While timing of insertion of NUMTs is imprecise, the observation such a cluster is highly statistically significant. Discussion : It is tempting to hypothesize that accelerated insertion of NUMTs is somehow linked to the speciation process. NUMTs could be either "riders i.e., the rate of insertion could be increased by the overall higher genome flexibility during the speciation period, or "drivers", i.e. they are fixed in the population at increased rate during speciation due to increased selective pressures. If correct, the hypothesis of accelerated pseudogenization would support the idea that evolution of our genus might have been discontinuous.
High-energy particle accelerators have been crucial in providing a deeper understanding of fundamental particles and the forces that govern their interactions. To increase the energy of the particles or to reduce the size of the accelerator, new acceleration schemes need to be developed. Plasma wakefield acceleration(1-5), in which the electrons in a plasma are excited, leading to strong electric fields (so called 'wakefields'), is one such promising acceleration technique. Experiments have shown that an intense laser pulse(6-9) or electron bunch(10,11) traversing a plasma can drive electric fields of tens of gigavolts per metre and above-well beyond those achieved in conventional radio-frequency accelerators (about 0.1 gigavolt per metre). However, the low stored energy of laser pulses and electron bunches means that multiple acceleration stages are needed to reach very high particle energies(5,12).

The use of proton bunches is compelling because they have the potential to drive wakefields and to accelerate electrons to high energy in a single acceleration stage(13). Long, thin proton bunches can be used because they undergo a process called self-modulation(14-16), a particle-plasma interaction that splits the bunch longitudinally into a series of high-density microbunches, which then act resonantly to create large wakefields. The Advanced Wakefield (AWAKE) experiment at CERN17-19 uses high-intensity proton bunches-in which each proton has an energy of 400 gigaelectronvolts, resulting in a total bunch energy of 19 kilojoules-to drive a wakefield in a ten-metrelong plasma. Electron bunches are then injected into this wakefield.

Here we present measurements of electrons accelerated up to two gigaelectronvolts at the AWAKE experiment, in a demonstration of proton-driven plasma wakefield acceleration. Measurements were conducted under various plasma conditions and the acceleration was found to be consistent and reliable. The potential for this scheme to produce very high-energy electron bunches in a single accelerating stage(20) means that our results are an important step towards the development of future high-energy particle accelerators(21-22).
Interaction between the rising vapor bubbles was investigated. The experiment was carried out in acetone under natural convection on a vertical heater 2.5 mm in diameter. Overheating of the heater surface before boiling-up varied from 30 to 120 degrees at saturation pressure from 20 to 40 kPa. Experiments have shown that the field of velocity and pressure behind a rising bubble has a strong influence on the growth dynamics of vapor bubble located below. This influence depends on the distance between the bubbles and growth phase of the upper bubble. When bubbles coalescence, high acceleration (100 m/s2) of particular parts of the interphase surface are observed. When the lower bubble coalescences with the upper bubble, the vapor spreads like a jet, and as a result, a conical perturbation is formed on the opposite side of the upper bubble.
This abstract book contains abstracts of the various research ideas presented at The Second Eurasian RISK-2020 Conference and Symposium.

The RISK-2020 Conference and Symposium served as a perfect venue for practitioners, engineers, researchers, scientists, managers and decision-makers from all over the world to exchange ideas and technology about the latest innovation developments dealing with risk minimization.