Comprehensive study of selection-value lines of zucchini on the level of damage by the yellow mosaic virus (ZYMV) and manifestation of other diseases

The work is aimed at the selection of linear samples of zucchini (Cucurbita pepo L. var. Giromontia Duch.) with increased complex resistance to abiotic factors of cultivation – zucchini yellow mosaic virus (ZYMV), powdery mildew, bacteriosis and other viral pathogens. Selection studies on choosing virus-resistant zucchini lines from the United Kingdom, Italy, the United States and Spain have identified a number of important correlations levels of resistance to ZYMV and to harmful microorganisms and viruses, belonging to other genera. The assessment of the resistance of the selected zucchini lines to the complex of studied diseases was performed on a 9-point scale of the classifier of the Council for Mutual Economic Assistance (CMEA). In total, during 2017–2019, 20 lines of zucchini were studied in the field. According to the complex resistance to all pathogens (zucchini yellow mosaic virus, green speckled mosaic, white mosaic and cucumber mosaic, bacteriosis and fusarium wilt), four lines have been identified – LZ 17-11, RVL-19, LZ 17-45 and LZ 17-49, which were resistant at the level of points 7 and 9 on the scale of CMEA. The possibility of selecting potentially resistant linear zucchini genotypes for ZYMV based on correlations with the manifestation of other diseases that occurred in the field has been confirmed. The highest level of correlation 0.59<rp<1.0) is observed when comparing the degree of powdery mildew development and symptoms of ZYMV (17 statistically confirmed values of the pairwise correlation coefficient or 80.95 %). A similar indicator for the pair “bacteriosis/ZYMV” is 14 statistically confirmed values of the pairwise correlation coefficient or 66.67 % (–1.0<rp<0.99), and for the pair “field viruses of other origin/ZYMV” – 11 values, which is 52.38 % (–1.0<rp<0.93). Zucchini samples were identified, in which statistically significant correlations were observed for all pairs of comparative traits. Among them, the variety-standard Chaklun and 4 more lines – LZ 17-1, LZ 17-8, LZ 17-50 and LZ 17-44 (–1.0<rp<0.92). The analysis of correlations shows a complex genetic organization of signs of resistance in zucchini lines to the studied pathogens and a high dependence of the manifestation of these signs on the response of the genotype of the line. One of the proofs of this experimental fact is that in all comparative pairs of indicators of the degree of development of certain diseases there are linear genotypes with both positive and negative values of Pearson correlation coefficients (rp). The high level of statistically significant correlations revealed gives grounds for wide use of correlation analysis in selection work for choosing lines potentially resistant to the complex of the most common diseases in vegetable agrocenoses

Frequency Dispersion of Impedance in a Molten Electrolyte

<p>It is an experimental fact that the impedance of an electrolyte as usually measured (by conductance bridge in a two electrode cell) is dependent on the frequency of the applied voltage. A quantity of fundamental physical significance in the elucidation of the structure of an electrolyte is the mobility of the conducting species. In order to know the mobilities of conducting species it is necessary to know the resistance of the particular electrolyte. However in order to establish the nature of the electrolyte i.e. its structure, resistance measurements are required which are precise and accurate and the variation of resistance (conductance) with temperature must be accurately know.</p>

Frequency Dispersion of Impedance in a Molten Electrolyte

<p>It is an experimental fact that the impedance of an electrolyte as usually measured (by conductance bridge in a two electrode cell) is dependent on the frequency of the applied voltage. A quantity of fundamental physical significance in the elucidation of the structure of an electrolyte is the mobility of the conducting species. In order to know the mobilities of conducting species it is necessary to know the resistance of the particular electrolyte. However in order to establish the nature of the electrolyte i.e. its structure, resistance measurements are required which are precise and accurate and the variation of resistance (conductance) with temperature must be accurately know.</p>

Influence of Air Dissolved in Hydraulic Oil on Cavitation Erosion

This article gives experimentally evidence that cavitation erosion in hydraulic components like valves and pumps is caused by vapour cavitation not gas or pseudo cavitation. In fact, the free air content which is released by vapour and gas cavitation reduces the erosion significantly. In order to clearly separate the different cavitation types, a test rig with a specially designed reservoir with integrated degassing capability is presented. As flow geometry a valve model with realistic dimensions and under realistic operating conditions was used, which ensures very high transferability of the results to the reality of hydraulic components in practical applications and typical operating conditions. A total of 4 five-hour long tests are performed and analysed. The quantification of the cavitation erosion is determined by the mass loss of the copper samples. The experimental results show a 4.4–5.1 times higher mass loss in tests with air-free oil compared to tests with air-saturated or oversaturated hydraulic oil. The experimental fact that air-free hydraulic oil causes significantly more cavitation erosion than normal (saturated) hydraulic oil, and its implications are discussed. The conclusion can be drawn, that further developments of hydraulic components and systems towards the use of air-free oil or increasing power densities will be disproportionately challenged by cavitation erosion.

The theory on thing's limits. Part 2: A brief analysis of the new knowledge of Newton's first law

According to the norm of identifying truth in this theory, and Newton's first law which is a basis that can look at the overall situation. By virtue of the electron storage ring as an experimental fact, it is pointed out: Only in reality can there be inertia, and vice versa. Inertia represents the continuity of the development of thing. As the speed gradually approaches to the c, the particle's mass also approaches to zero along with its static mass, which is the energy shrinkage effect of high-speed particles, and also the primary factor causing the spectrum redshift. Therefore, the Big Bang theory is wrong. All photons are produced from the high-density particles through electromagnetic radiations. Wherever there is fluctuation, there must be mass, and vice versa. This is the correct understanding of "wave-particle duality". No matter the high-speed electrons or the photons produced by them all have different static masses, but their charge-mass ratio is always the same physical constant, and not affected by relativistic effects and electromagnetic radiations. Which constitutes the internal mechanism of the uncertainty principle and conforms to the experimental facts related to it. It can be proved that in a constant magnetic field, the high-speed electron or photon with a relatively large curvature radius, which has a high moving speed and less mass, energy and wave frequency. Since Einstein used the absolute space-time established by Newton as the criterion and came to the conclusion that relative space-time was curved, then he should no longer make circular arguments, that was, used the relative space-time as the criterion, to change the unit length and time established by the absolute space-time.

Interaction of N-acetylneyraminic acid with surface of silica with fructose in aqueous solution

Quantum chemical simulation of the adsorption of N acetylneuraminic acid (NANA) on the surface of silica with the participation of the fructose molecule by the method of density functional theory B3LYP, 6-31G (d, p) was done. The influence of the solvent was taken into account in the supermolecular and continuum approximations, and a cluster approach was used for the adsorption complexes. NANA adsorption of the hydrated silica surface was considered as a process of replacement of water molecules on the silica surface by adsorbate molecules. Two schemes of influence of fructose molecule on NANA adsorption are considered. According to the first scheme, the hydrated NANA molecule interacts with the hydrated silicon-fructose adsorption complex. According to the second scheme, the cluster of hydrated silica interacts with the hydrated NANA-fructose complex. The energy of intermolecular interaction according to the scheme 1 is -9.2 kJ / mol, which is significantly lower compared to the same value with the participation of glucose or sucrose (-20.5 and -86.2 kJ / mol). Scheme 2 proved to be a thermodynamically unfavorable process, as its energy effect is +6.9 kJ / mol, in contrast to similar processes for glucose (-21.8) and sucrose (-87.7 kJ / mol). This confirms the experimental fact of the interaction of substances in a mixture of NANA with carbohydrates in relation to the interaction with silica in comparison with the interaction of substances with silica separately.

Computational analysis the relationships of energy and mechanical properties with sensitivity for FOX-7 based PBXs via MD simulation

Molecular dynamics (MD) simulations have been applied to investigate 1, 1-diamino-2, 2-dinitroethene (FOX-7) crystal and FOX-7 (011)-based polymer-bonded explosives (PBXs) with four typical polymers, polyethylene glycol (PEG), fluorine-polymer (F 2603 ), ethylene-vinyl acetate copolymer (EVA) and ester urethane (ESTANE5703) under COMPASS force field. Binding energy ( E bind ), cohesive energy density (CED), initiation bond length distribution, RDG analysis and isotropic mechanical properties of FOX-7 and its PBXs at different temperatures were reported for the first time, and the relationship between them and sensitivity. Using quantum chemistry, FOX-7 was optimized with the four polymers at the B3LYP/6-311++G(d,p) level, and the structure and RDG of the optimized composite system were analysed. The results indicated that the binding energy presented irregular changes with the increase in temperature. The order of binding ability of different binders to the FOX-7 (011) crystal surface is PEG > ESTANE5703 > EVA > F 2603 . When the temperature increases, the maximum bond length ( L max ) of the induced bond increases and the CED decreases. This result is achieved in agreement with the known experimental fact that the sensitivity of explosives increases with temperature, and they can be used as the criterion to predict the sensitivity of explosives. The descending order of L max is FOX-7 > F 2603 > ESTANE5703≈EVA > PEG. The intermolecular interactions between FOX-7 and the four polymers were mainly weak hydrogen bonding and van der Waals interactions, and these interactions helped to reduce the bond length of C-NO 2 , leading to a decrease in the sensitivity of FOX-7. The addition of polymers can effectively improve the mechanical properties of explosives. Among the four polymers, EVA has the best effect on improving the mechanical properties of FOX-7 (011). At the same temperature, the modulus can be used to predict the sensitivity of high-energy materials. Cauchy pressure can predict the sensitivity of non-brittle energetic materials. The nature of the interaction between FOX-7 and the four polymers is hydrogen bonding and van der Waals force, of which hydrogen bonding is the main one. These studies are meaningful for the formulation design and sensitivity prediction of FOX-7 and its PBXs.

Capacitance creep and recovery behavior of magnetorheological elastomers

As a novel conductive elastomer, magnetorheological elastomers (MREs) featuring both high sensitivity and wide working range have been employed as a new sensing material for flexible tactile sensors. Their sensing mechanism, that is, the spatial distribution rearrangement of particles under compression, completely differs from their conventional counterparts. The piezo-capacitive effect of MREs resulting from the unique mechanism of particles rearrangement is actually a response to the microscopic mechanical movement of particles. This nature brings a core concern on the intrinsic relationship between their mechanical and electrical properties. This study illuminates them from the perspective of electrical creep and recovery behavior of MREs. We give a meaningful analysis for the capacitance creep-recovery mechanism. The experimental fact strongly demonstrated that the particles rearrangement was the direct cause, while the strain creep was an indirect cause. All the behaviors were well interpreted by an evolution mechanism of the particles rearrangement driven by the mechanical strain creep of the flexible matrix under constant pressure. In simpler terms, the electrical creep was induced by the mechanical creep. We further explored the creep effect in practical applications and found a “self-healing” behavior, which indicated that the MRE sensors could obtain a stable sensing capability after a pre-processing.

Asymmetric Dinuclear Lanthanide(III) Complexes from the Use of a Ligand Derived from 2-Acetylpyridine and Picolinoylhydrazide: Synthetic, Structural and Magnetic Studies

A family of four Ln(III) complexes has been synthesized with the general formula [Ln2(NO3)4(L)2(S)] (Ln = Gd, Tb, Er, and S = H2O; 1, 2 and 4, respectively/Ln = Dy, S = MeOH, complex 3), where HL is the flexible ditopic ligand N’-(1-(pyridin-2-yl)ethylidene)pyridine-2-carbohydrazide. The structures of isostructural MeOH/H2O solvates of these complexes were determined by single-crystal X-ray diffraction. The two LnIII ions are doubly bridged by the deprotonated oxygen atoms of two “head-to-head” 2.21011 (Harris notation) L¯ ligands, forming a central, nearly rhombic {LnIII2(μ-OR)2}4+ core. Two bidentate chelating nitrato groups complete a sphenocoronal 10-coordination at one metal ion, while two bidentate chelating nitrato groups and one solvent molecule (H2O or MeOH) complete a spherical capped square antiprismatic 9-coordination at the other. The structures are critically compared with those of other, previously reported metal complexes of HL or L¯. The IR spectra of 1–4 are discussed in terms of the coordination modes of the organic and inorganic ligands involved. The f-f transitions in the solid-state (diffuse reflectance) spectra of the Tb(III), Dy(III), and Er(III) complexes have been fully assigned in the UV/Vis and near-IR regions. Magnetic susceptibility studies in the 1.85–300 K range reveal the presence of weak, intramolecular GdIII∙∙∙GdIII antiferromagnetic exchange interactions in 1 [J/kB = −0.020(6) K based on the spin Hamiltonian Ĥ = −2J(ŜGd1∙ ŜGd2)] and probably weak antiferromagnetic LnIII∙∙∙LnIII exchange interactions in 2–4. Ac susceptibility measurements in zero dc field do not show frequency dependent out-of-phase signals, and this experimental fact is discussed for 3 in terms of the magnetic anisotropy axis for each DyIII center and the oblate electron density of this metal ion. Complexes 3 and 4 are Single-Molecule Magnets (SMMs) and this behavior is optimally observed under external dc fields of 600 and 1000 Oe, respectively. The magnetization relaxation pathways are discussed and a satisfactory fit of the temperature and field dependencies of the relaxation time τ was achieved considering a model that employs Raman, direct, and Orbach relaxation mechanisms.

Mathematical modeling of strength characteristics of chromium ferritic-martensitic steels

To predict the chemical composition of heat-resistant high-chromium steels with ferritic-martensitic structure (HFMS) (with the number of alloying elements up to 10 and the same number of parameters of production and heat treatment technology), a mathematical model is needed. In this work, I searched for the dependences of the yield strength and ultimate strength of HFMS on the content of alloying elements and test temperature without analyzing technological factors due to their uniformity. Analysis of the samples from ten steel grades was carried out on the basis of the experimental data including 63 tensile tests at 20 – 720 °С. Regression multiplicative dependencies are proposed to take into account exponential and power-law form through the corresponding factors: solid solution and dispersion hardening, total temperature softening of the steel, carbon content, total molybdenum and tungsten content, and strengthening effect of manganese. Estimates of the effect of nitrogen and silicon on the predicted strength characteristics have shown that a factor that takes into account the effect of nitrogen improves the model and is necessary in the general formula, and introduction of a factor that takes into account silicon content, worsens the model. Introduction of a silicon factor in the formula may be necessary in analysis of steels with high silicon content (type EP-823). The experimental fact of a close relationship between yield strengths and tensile strengths for the studied HFMS steels made it possible to use for the yield strength the form of equation and forecast for the ultimate strength, which differs only by coefficients in variables. Deviation of the calculated model yield strengths and tensile strengths from experimental is 13 – 18 %. An example of analysis of the yield strength behavior of steels with experimental chemical compositions is given. It is shown that the dependences found for the yield strength and tensile strength are stable with respect to the increase of experimental data matrix: with an increase in the number of experiments from 94 and higher, the coefficient of variation V monotonously decreases up to a maximum array size of 299 experiments.