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The paper presents the results of large-scale experimental and simulation study of the propagation of premixed near the lower flammability limit hydrogen-air spherical flame. Experiments were carried out in a cylindrical volume of 4.5 m3 covered with thin polyethylene film. The effect of buoyancy and stability of the flame ball in the unconfined volume are studied experimentally and numerically. Numerical analysis of the problem shows that the flame ball becomes unstable after some period of stable propagation that qualitatively corresponds with experimental results. The effect of chemistry in a flame ball propagation process is studied numerically. A comparison of experimental results and numerical simulations are presented. A comparison of numerical simulations with and without chemistry is shown. The subject and results of the study are of critical importance for the industrial explosion safety and hydrogen safety of nuclear power plants.

The article presents numerical simulation of the propagation of hydrogen-air flame in adiabatic conditions and with the heat absorbtion on the wall. The results of experiments in a cylindrical shell of 4.5 m3 are compared with the results of numerical simulation. The quantitative agreement between the experimental and numerical results is achieved. It is shown that the numerical model of the combustion with the heat losses under the conditions of the experiment may account the heat losses as an integral effect of the heat absorbtion.

Background Issues of hydrogen explosion safety are extremely relevant. Search for solutions requires both experimental and computational methods. Aim To experimentally study the turbulent combustion of hydrogen-air mixtures and to test the CABARET-COMBUSTION CFD calculation code using the obtained data. Materials and methods The study includes experiments conducted in a facility representing a large diameter pipe, as well as numerical simulation of deflagration combustion. Results The calculated data on the flame front propagation velocity and pressure dynamics at the shock wave front are consistent with experimental results. Conclusion The obtained results indicate the potential of using the CABARET-COMBUSTION CFD code in the numerical solution of hydrogen-air mixture combustion problems. This code and its testing on data obtained with high-quality diagnostics will increase the predictive capabilities of supercomputer simulation for the analysis of hypothetical accidents at a qualitatively new level.

The passage of laser radiation through a scattering medium is studied experimentally. A method of determining the optical characteristics of a scattering media is proposed. The method is based on the measurements of time distributions of the intensity of ultrashort laser pulses for two layer thicknesses of the medium to be studied. The measurements are carried out with the use of a single-photon counting system. The proposed method is used to determine the absorption and scattering coefficients of a model medium from the experimental data.

The high brightness and photostability of the green fluorescent protein StayGold make it a particularly attractive probe for long-term live-cell imaging; however, its dimeric nature precludes its application as a fluorescent tag for some proteins. Here, we report the development and crystal structures of a monomeric variant of StayGold, named mBaoJin, which preserves the beneficial properties of its precursor, while serving as a tag for structural proteins and membranes. Systematic benchmarking of mBaoJin against popular green fluorescent proteins and other recently introduced monomeric and pseudomonomeric derivatives of StayGold established mBaoJin as a bright and photostable fluorescent protein, exhibiting rapid maturation and high pH/chemical stability. mBaoJin was also demonstrated for super-resolution, long-term live-cell imaging and expansion microscopy. We further showed the applicability of mBaoJin for neuronal labeling in model organisms, including Caenorhabditis   elegans and mice. mBaoJin is a monomeric derivative of the bright and photostable green fluorescent protein StayGold. mBaoJin offers favorable photophysical properties for use in diverse protein tagging and subcellular labeling applications.

Large-scale detectors consisting of a liquid scintillator target surrounded by an array of photo-multiplier tubes (PMTs) are widely used in the modern neutrino experiments: Borexino, KamLAND, Daya Bay, Double Chooz, RENO, and the upcoming JUNO with its satellite detector TAO. Such apparatuses are able to measure neutrino energy which can be derived from the amount of light and its spatial and temporal distribution over PMT channels. However, achieving a fine energy resolution in large-scale detectors is challenging. In this work, we present machine learning methods for energy reconstruction in the JUNO detector, the most advanced of its type. We focus on positron events in the energy range of 0–10 MeV which corresponds to the main signal in JUNO – neutrinos originated from nuclear reactor cores and detected via the inverse beta decay channel. We consider the following models: Boosted Decision Trees and Fully Connected Deep Neural Network, trained on aggregated features, calculated using the information collected by PMTs. We describe the details of our feature engineering procedure and show that machine learning models can provide the energy resolution σ=3% at 1 MeV using subsets of engineered features. The dataset for model training and testing is generated by the Monte Carlo method with the official JUNO software.

The results of tests of vertically loaded long bored piles in clayey soils by the immersion jack method are obtained. The peculiarities of soil resistance formation under the lower end and along the lateral surface of piles are shown. The necessity of calculation of such piles on the soil by the second limit state with consideration of the pile shaft compressibility is substantiated. A methodology for calculating the settlement of a single pile and determining the allowable load thereon at a given settlement of the pile head based on the kinematic scheme of including the soil base and the pile shaft in the work upon pile loading is developed. The results of numerical studies on the basis of pile tests on an actual object are presented.

We present the experimental observation of the reduction of multiple scattering of high-energy positively charged particles during channeling in single crystals. According to our measurements the rms angle of multiple scattering in the plane orthogonal to the plane of the channeling is less than half that for non-channeled particles moving in the same crystal. In the experiment we use focusing bent single crystals. Such crystals have a variable thickness in the direction of beam propagation. This allows us to measure rms angles of scattering as a function of thickness for channeled and non-channeled particles. The behaviour with thickness of non-channeled particles is in agreement with expectations whereas the behaviour of channeled particles has unexpected features.

Fluctuating asymmetry (FA) is often proposed as an early warning indicator of subtle changes in plant functioning. Here, we tested whether leaf FA responds consistently to the alleviation of cold stress in three boreal willow species—Salix caprea, S. myrsinifolia and S. phylicifolia. We enclosed 10 naturally growing individuals of each species in open‐top chambers at budburst and compared their leaf traits to those of unenclosed control plants after leaf development had ceased. All measurements were conducted blind to treatment. Willows in open‐top chambers showed a 9% increase in specific leaf area, indicating that the 1°C–2°C warming within chambers affected leaf development. However, neither leaf length nor FA responded significantly to the warming treatment. FA also did not differ among species or individual plants, suggesting that it may reflect statistical noise rather than a reliable biological signal in this context. These findings add to growing concerns that many reported FA responses to environmental change may result from confirmation bias—an issue that can be mitigated by adopting blind measurement protocols. We tested whether leaf fluctuating asymmetry (FA) responds to experimental warming in three boreal willow species using open‐top chambers and blind measurements. While warming increased specific leaf area, neither leaf length nor FA showed significant responses, and FA did not differ among species or individuals. These results suggest that FA may represent statistical noise rather than a reliable indicator of environmental stress.

Spring ephemeral plants represent a unique ecological category of herbaceous plants, characterized by early blooming and vivid flowers with significant ornamental value. Understanding the adaptive strategies of spring ephemerals is crucial for the introduction and cultivation of early spring plants, as well as for optimizing light energy utilization and nutrient cycling within ecosystems. We evaluated 26 functional traits across four spring ephemerals and four spring non-ephemeral plants along an elevation gradient. By establishing a plant functional trait network, we examined the adaptation strategies of early spring plants at different elevations and compared the differences in adaptation strategies between two types of plants. Spring ephemerals exhibited higher concentrations of carbon and nitrogen, lower concentrations of carbohydrates, higher edge density and modularity in trait networks, and stronger linkages between defense traits. Plants at higher elevations demonstrated higher leaf dry matter content and leaf total flavonoid concentration, and lower nitrogen concentration, influenced by temperature, precipitation, and soil nutrients. These results demonstrated that spring ephemerals have a strong nutrient uptake capacity, and adopt resource competition strategies to rapidly accumulate nutrients and reproduce. The plants at higher elevations adopt more conservative strategies, with trait networks showing increased modularity, edge density, and closer correlations among traits to enhance resource utilization. This study provides new insights into the adaptive strategies of spring ephemerals by demonstrating how plants allocate resources for growth and defense through the regulation of trait variation and correlations among traits.