A class of binary digit-position sequences, obtained from the linear recurring sequence of maximal period over Galois rings of odd characteristics and admitting an effect of twofold reduction of ...period, has been found. A condition was found where sequences of some fixed linear recurring sequence of maximal period over Galois fields with such property are exhausted only by that class.
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•Laser ablation in liquid phase was used to prepare both Bi and Si based single colloids.•When mixed together, the colloids remain mainly unreacted in absence of additional ...irradiation.•Upon irradiation with laser, the mixed colloid gives rise to a new nanomaterial containing bismuth silicate phases.•The novel nanomaterial proves to be efficient photocatalyst for degrading rhodamine B and phenol.
Having a wide range of applications, bismuth silicate-based materials (BSO) attract attention of numerous researchers. Typically, they are synthesized either from active chemicals or through high-energy impact on their precursors. The present work is the first report on BSO-based nanomaterials prepared via laser processing in liquid phase in which the following two-step scheme was realized: (1) Individual colloids of Bi- and Si-based nanoparticles were obtained via ablating their metallic targets in distilled water and then mixed; (2) Post-treatment of the mixed colloid was performed with the same laser beam as in stage (1). The products obtained after drying of non-treated and post-treated mixed colloids (denoted as samples BSO and BSO_hν, respectively) were carefully characterized using a set of microscopic, spectroscopic and electrochemical analyses, after which their photocatalytic performance in presence of model organic dye (rhodamine B) and phenol was tested. The additional laser treatment was found to lead to active interaction between Bi- and Si-containing species and stimulated formation of phases with Bi-O-Si bonds. The post-irradiated sample BSO_hν showed improved stability and catalytic performance, thus opening avenues for wider use of laser processing in liquids as a method allowing for preparation of nanostructures with complex chemical composition.
The Dynamic Albedo of Neutrons (DAN) instrument on board Mars Science Laboratory has been operating successfully since the landing and has been making measurements regularly along Curiosity's ...traverse at the surface. DAN measures thermal (E < 0.4 eV) and epithermal neutrons (0.4 eV < E < ~1 keV) while operating in two different modes: active and passive. The active mode uses a pulsed neutron generator (PNG) to study the geological characteristics of the subsurface. In the passive mode, DAN measures the background neutron environment. This paper presents results of measurements in the passive mode from landing through to sol 100 and provides an interpretation of the data based on extensive Monte Carlo simulations. The main observations are summarized as follows: (1) the thermal neutron counts vary strongly along the rover traverse while the epithermal counts do not show much variation; (2) the neutrons from the Multi‐Mission Radioisotope Thermoelectric Generator (MMRTG) are a larger contributor to the DAN passive data than the Galactic Cosmic Ray (GCR)‐induced neutrons; (3) for the MMRTG neutrons, both the thermal and the epithermal counts increase as a function of the subsurface water content; (4) on the other hand, for the GCR‐induced neutrons, the thermal counts increase but the epithermal counts decrease as a function of the subsurface water content; and (5) relative contributions by the MMRTG and GCR to the DAN thermal neutron counts at the Rocknest site, where the rover was stationed from sol 59 to sol 100, are estimated to be ~60% and ~40%, respectively.
Key Points
The DAN passive mode measures the MMRTG neutrons and GCR‐induced neutrons
The thermal neutron counts show strong variability along the rover traverse
The majority of the DAN passive counts are from the MMRTG neutrons
This paper presents the results of the comparative research of combustion specifics of coal-water fuel produced from low-ash and high-ash Ukrainian flame coal. The analysis shows that the effect of ...the ash content in the coal-water fuel on the duration of the burning of a fuel drop depends on the drop size. The full combustion time of CWF drop based on the low-ash coal can be both less and longer than that of high-ash coal under the identical conditions for different equivalent diameters of the fuel drop. This specific is explained with the domination of different physical factors during the fuel combustion process.
The results of this research extend significantly our knowledge of coal-water fuel, allow understanding some issues of its combustion and are important for the design of the specialized energy facility which is used coal-water fuel as an energy source.
•Ash content in the coal-water fuel has an ambiguous effect on fuel combustion.•Burning time is the same for different ash content for a critical drop size.•Critical drop size depends on medium temperature of fire box.
One of the main indicators characterizing the quality of modern products are reliability indicators. The detection and development of effective measures to combat corrosion of aviation materials and ...structures is one of the most important areas of ensuring safety, high operational reliability and efficiency of modern aviation technology. It is one of the modern trends in the development of aviation at this stage of development of aircraft construction. This article discusses the technological aspects of the development of the use of composite materials in aircraft construction at the present stage of society development. The aircraft industry is one of the high-tech industries where modern polymer and composite materials play a decisive role. In this regard, the development of composite and polymer materials is the future of all the world aviation.
We have developed and realized a novel multichroic seashell antenna with internal bandpass filters by resonant slots and cold-electron bolometers (CEB). Slots and CEBs are connected by coplanar ...waveguides (CPW) instead of microstrip lines to realize the most reliable single-layer technology. The internal resonance is organized by a series resonance of slots with CPW and capacitances of superconductor/insulator/normal (SIN) tunnel junctions. In contrast, a conventional multichroic pixel consists of a wideband sinuous antenna coupled to TES detectors by long microstrip lines with overlap and external on-chip filters for different frequency bands. A common problem with a conventional multichroic pixel is that the beam width is frequency dependent for different frequency bands. Besides that, this system with external filters is quite large and includes long microstrip lines with unavoidable overlap and rater high losses. The multichroic seashell antenna with internal resonances avoids all these problems. The main advantage of this antenna is an opportunity to tune separate pairs of phased slots for each frequency band independently. We used pairs of λ/2 slots for 75 and 105 GHz, connected by CPW to CEBs. The connection of CPW to slots was shifted closer to the end of slots for proper RF matching. Each CEB included two SIN junctions and an absorber. SIN junctions had capacitances of 77 and 67 fF. Wave impedance of the antenna was near 50 Ohm and resistance of the absorber was matched to this value. RF testing was done at 314 mK irradiating this chip by frequency sweep of a generator from 78-118 GHz. The response curves have shown clear resonances around 75 and 105 GHz with a quality factor around 5. These experiments confirmed that the seashell antenna with the internal filters by resonant slots and CEBs could effectively be used for creating multiband elements.
Research on the combustion of coal-water fuel has grown significantly in recent years. Many experimental and numerical calculated data are available in the scientific literature. Nowadays, a large ...number of different models of the combustion of coal-water fuel have been developed for numerical research. However, there is no systematic generalization of all these data in the published results.
This article is an attempt to fill the gap in the field of such a generalization. Simple equations are obtained based on a generalization of experimental data on the combustion of coal-water fuel for engineering applications, as well as to verify already existing and new mathematical models being developed. Those equations are basic for calculation of each stage duration of “pure” coal-water fuel (without any additions) combustion parameters in still air; they take into account all metamorphic stages of source coal, the different water content in the range of 25–50% and mineral impurities content (ash) 0.5–60% in the temperature range of the oven medium 550–1000 °C.
•Main physics of combustion is described with exponent (power) functions.•Burning time depends on droplet size in exponent with constant degree 1.6•Usage of fuel ignition temperature allows simplifying empirical equations.•The effect of water, ash, and coal metamorphic stage are multiplicative.
We proposed a procedure for screening drug compounds by high-resolution mass spectrometry with atmospheric pressure laser plasma ionization (APLPI). The analytical performance of the method was ...studied on examples of five medicinal compounds: Lidocaine, Bendazole, Papaverine, Chloropyramine, and Carbamazepine. Calibration dependences were obtained in the analysis of model solutions and blood samples; sensitivity coefficients were determined. The relative standard deviation of the results is in the range 20–27%. The APLPI technique can detect promptly and reliably the studied medicinal compounds at concentrations 0.5–6 ng/mL in a sample. The sensitivity of APLPI exceeds that of atmospheric pressure electrospray ionization by 4–16 times.
The pseudopotential approach is a useful tool for the qualitative description of ion motion in inhomogeneous high-frequency electric fields, often used in mass spectrometric devices. However, in the ...theoretical study of the motion of ions in high-frequency electric fields with close frequencies, mathematical ambiguity arises, caused by the nonequivalence of different mathematical approaches. The paper considers and compares the time-dependent pseudopotential model and the model of solenoidal (vortex) pseudoforces, that is, vortex drift. The vortex drift model in high-frequency electric fields with close frequencies can be replaced by the model of ion motion in a pseudopotential varying in time. The theory of almost periodic time signals with two characteristic time scales, fast and slow, eliminates the ambiguity in selecting the correct mathematical method for describing ion motion in high-frequency electric fields.
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