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A new methacrylic monomer, 3,5-bis[2-(N-ethylanilino)ethoxy]benzyl methacrylate (MBA), has been synthesized. Methacrylic copolymers with different content of bi-chromophore fragments in the side chain were obtained by radical copolymerization of methyl methacrylate and MBA, followed by azo-functionalization reaction. The composition of the obtained copolymers was established, and their thermal properties were determined. Thin films of synthesized copolymers were prepared by spin-coating and the nonlinear optical characteristics of the obtained materials were investigated.

The authors have formulated macrokinetic models of thermal decomposition of dolomite that vary in the number of the considered effective chemical processes, the mechanism of evacuation of carbon dioxide, the dependent/independent behavior of chemical reactions, and the number of parameters. The models were used as basic ones for approximating experimental data on the thermal decomposition of dolomite. The experiments on dolomite decomposition were conducted with a Q-1000 derivatograph of the MOM Company at a rate of heating of the samples of 5, 10, and 20 K/min, and also in a quasi-thermal regime. Based on the array of experimental data, the authors have determined the parameters of dolomite-decomposition models. An analysis of the adequacy of the models to the experimental data has been made. It has been shown that taking account of the series character of decomposition of dolomite and calcite in two reactions does not result in the improvement of the approximation accuracy of experimental data. The approximation accuracy of experimental data corresponds to the accuracy of approximated experimental data, with the models with 5 to 7 parameters exhibiting no noticeable advantages over 3- and 4-parametric models. However, the model with 2 parameters shows much lower accuracy. The models whose parameters were set according to the dynamic dolomite-decomposition data satisfactorily describe quasi-isothermal decomposition regime too; however, in modeling the latter, it is expedient to set the model′s parameters according to the data of quasi-isothermal experiments.

Heteroleptic cadmium(ii) carboxylates with anions of pentafluorobenzoic (pfb), benzoic (bz), and 2-furancarboxylic (fur) acids were prepared by the crystallization from aqueous solutions. The cadmium(ii) pentafluorobenzoate-benzoate complex is structurally similar to the starting compound [Cd(pfb)(H2O)4]n • n(pfb): bz anions are involved in the cationic 1D polymer {[Cd(bz)(H2O)3]n}n+, whereas pfb anions are outer-sphere. The pentafluorobenzoate-2-furan-carboxylate compound [Cd(fur)(pfb)(H2O)2]n•n(H2O) is a 1D coordination polymer. The heteroleptic TbIII complex [Tb2(bz)2(pfb)4(H2O)2(EtOH)2]•2Hbz has a molecular structure. The supramolecular crystal structures of the new compounds are stabilized by non-covalent interactions.

В статье демонстрируется асимметрия между темпоральными значениями слов со значением ‘близкого’ и ‘далекого’, и анализируются ее семантические источники. Одно из основных проявлений этой асимметрии—предпочтительная референция к будущему у слов со значением ‘близкого’ (ср. близкие каникулы = ‘каникулы в будущем’) и к прошлому у слов со значением ‘далекого’ (ср. далекие годы = ‘годы в прошлом’). Однако эта общая тенденция осложняется другими факторами. Для кратких форм прилагательного близкий темпоральное употребление характерно (Близок день нашей победы), а для кратких форм далекого—нет (?Далек день нашей победы). Для предикативного наречия близко невозможно употребление в темпоральном значении с предлогом до (*До Нового года близко), характерное для наречий далеко и недалеко (До Нового года еще далеко / уже недалеко). Интересно, что в таком употреблении временная референция далеко меняется: оно указывает не на прошлое, а на будущее. У дейктических наречий тут и там распределение временной референции в таксисном значении обратное: тут чаще указывает на прошлое, а там—на будущее: Иду я по улице, и тут мне навстречу медведь vs. Скоро весна, а там и лето. Однако асимметрия сохраняется: тут указывает на немедленное следование, а там—на большие временные промежутки.

As part of the creation of a unique T-15MD tokamak with a magnetic field of 2 T and an aspect ratio of 2.2, the first one of a series (8 pieces) of microwave setups of a megawatt power level for electron–cyclotron plasma heating and current drive was developed and successfully tested. The setup includes a gyrotron, power supplies, a microwave radiation transmission line, and a fast (response time is no more than 10 μs) gyrotron emergency protection system. The generation regime was experimentally demonstrated with the parameters 1 MW/30 s/82.6 GHz for an efficiency of 57%.

We study the possibility of using the technology of 3D photopolymer printing with subsequent metallization of working surfaces for developing electrodynamic components of microwave devices. The technology applicability is considered by examples of mockups of a profiled helical waveguide for a microwave undulator of a Compton free-electron laser and a periodic slow-wave system of a backward-wave oscillator with a ribbon electron beam. The results of “cold” measurements of the parameters of these electrodynamic systems are presented and good agreement with the simulation results is obtained, which confirms the prospects of using additive technologies for developing components of the vacuum microwave electronic devices.

The reaction of Cd(NO3)2 · 4H2O and Eu(NO3)3 · 6H2O or Tb(NO3)3 · 6H2O with potassium 3,5-di-tert-butylbenzoate (Kbzo) and N-donor ligands (1,10-phenanthroline (phen), 2,4-lutidine (2,4-lut), 3,4-lutidine (3,4-lut), phenanthridine (phtd), 2,3-cyclododecenopyridine (cdpy), acridine (acr)) afforded heterometallic LnCd2 complexes: [EuCd2(bzo)7(EtOH)2(phen)] (2), [LnCd2(bzo)7(2,4-lut)4] (Ln = Eu (3), Tb (4)), [EuCd2(bzo)7(H2O)2(2,4-lut)2] · MeCN (5), [EuCd2(NO3)(bzo)6(EtOH)2(2,4-lut)2] (6), [EuCd2(bzo)7(H2O)(EtOH)(3,4-lut)2] · 5EtOH (7), 3[EuCd2(bzo)7(H2O)2(phtd)2] · 4phtd (8), [EuCd2(bzo)7(EtOH)3(cdpy)] (9), 2[EuCd2-(bzo)2(EtOH)4] · acr (10). The structures of complexes 2, 3, and 5–10 were determined by single-crystal X-ray diffraction. The isostructurality of complexes 3 and 4 was confirmed by powder X-ray diffraction. The structure of the trinuclear {Ln2Cd} metal core is stable and independent of the type of peripheral ligands coordinated to cadmium atoms. Photoluminescent properties of compounds 3 and 4 were studied.

T cells play a vital role in combatting SARS-CoV-2 and forming long-term memory responses. Whereas extensive structural information is available on neutralizing antibodies against SARS-CoV-2, such information on SARS-CoV-2-specific T-cell receptors (TCRs) bound to their peptide–MHC targets is lacking. Here we determine the structures of a public and a private TCR from COVID-19 convalescent patients in complex with HLA-A2 and two SARS-CoV-2 spike protein epitopes (YLQ and RLQ). The structures reveal the basis for selection of particular TRAV and TRBV germline genes by the public but not the private TCR, and for the ability of the TCRs to recognize natural variants of RLQ but not YLQ. Neither TCR recognizes homologous epitopes from human seasonal coronaviruses. By elucidating the mechanism for TCR recognition of an immunodominant yet variable epitope (YLQ) and a conserved but less commonly targeted epitope (RLQ), this study can inform prospective efforts to design vaccines to elicit pan-coronavirus immunity., Structural immunology is critical in understanding the interplay between the immune response and the infective agent but such studies in T cells and SARS-CoV-2 lag behind those of antibodies and B-cell receptors. Here the authors assess recognition of SARS-CoV-2 spike epitopes and their natural variants by public and private T cell receptors.

To discuss the nature of the compositional heterogeneity of the peridotite massifs of the Polar Urals (Russia), the geochemical study by LA-ICP-MS of pyroxenes and amphiboles from these mantle formations was performed. The trace element compositions in clinopyroxenes indicate the existence of the mantle protolith of two types. The first protolith type, represented by lherzolites and diopside harzburgites, was originated from the partial melting (5%–10%) under the spinel fades conditions, while the second one, represented by diopside harzburgites, was formed under the polybaric partial melting (17%–19%) under garnet and spinel fades conditions. Subsequently, the mantle peridotite protolith was subject to fluid-induced partial melting in the suprasubduction setting that was resulted in the formation of harzburgites. Being affected by penetrating melts and fluids peridotites experienced the refertilization (LREE enrichment of clinopyroxenes) and high-temperature hydratation with subsequent development of pargasite and Mg amphibole. The high-T fluid-induced metamorphism at the subduction zone was accompanied by the formation of metaperidotites with clinochlore and REE-depleted tremolite.

The catalytic activity of synthesized by the template method mesoporous silica doped with dysprosium and modified with nickel (Dy-Ni/MPS) in the hydrogenation of benzene, ethylbenzene and xylenes has been studied. The catalyst is characterized by various techniques such as TEM, SEM, BET, XRD, ICP, XRF analyses. It is shown that the presence of dysprosium in the MPS structure increases the activity of the catalyst. The catalytic activity of the catalyst (Dy-Ni/MPS) has been explored in hydrogenation reaction of benzene derivatives with excellent conversion (96–100%) at low pressure.

Background In the recent years, the overall trends in hospital admission and mortality of interstitial lung disease (ILD) are unknown. In addition, there was some evidence that interstitial lung disease death rate highest in the winter but this finding was only available in one study. This study will investigate the trend and seasonal variations in hospital admission and mortality rates of ILD from 2006 to 2016. Method From the Nationwide Inpatient Sample database, we collected all cases with the International Classification of Diseases (ICD)-9 or ICD-10 codes of ILD excluding identifiable external causes (drug, organic or inorganic dusts) from 2006 to 2016. Hospitalization rates of each year were calculated based on U.S Census population data. Monthly hospitalization and in-hospital mortality rates were analyzed by seasonal and trend decomposition. Subgroups of idiopathic interstitial fibrosis (IPF), acute respiratory failure (ARF), pneumonia were analyzed. Results From 2006 to 2016, all-cause hospital admission rate of patients with interstitial lung disease (ILD) and IPF-only subgroup declined but their overall mortality remained unchanged (except IPF subgroup and acute respiratory failure subgroup). Acute respiratory failure related admission account for 23% of all causes and pneumonia 17.6%. Mortality of ILD in general and subgroup of ILD with ARF was highest in winter, up to 8.13% ± 0.60 and 26.3% ± 10.2% respectively. The seasonal variations of hospital admission and mortality of ILD in general was not changed when infectious pneumonia cases were ruled out. All cause admission rates were highest in months from January to April. Subgroup analysis also showed seasonal variations with highest hospitalization rates for all subgroups (IPF, ARF, pneumonia) in the months from December to April (winter to early Spring). Conclusion From 2006 to 2016, admission rates of ILD of all causes and IPF subgroup declined but in-hospital mortality of ILD of all causes remained unchanged. Mortality of IPF subgroup and acute respiratory failure subgroup trended down. All-cause hospital admissions and mortality of ILD have a strong seasonal variation. Hospitalization rates for all subgroups (IPF, ARF, pneumonia) were highest in the months from December to April.

The reaction products of [Cd(piv)2] (piv is–O2CBut) with isoquinoline (iqn), 2,4-lutidine (lut), phenanthridine (phend), 2,3-cyclododecenopyridine (cpy), and triethylamine (Et3N) were synthesized and their structures were determined. The steric factors were found to play a more important role in cadmium(ii) pivalate complexes compared to 3d metal carboxylates in the +2 oxidation state. The reaction of [Cd(piv)2] with isoquinoline produces only the mononuclear complex [Cd(piv)2(iqn)3] (1). The reaction of [Cd(piv)2] with pyridine derivatives bearing a bulky substituent at the α position is accompanied by the formation of symmetrical dinuclear complexes of the composition [Cd2(piv)4(L)2]. In the complexes with L = lut (2) or phend (3), the cadmium(ii) atoms are linked by two chelating-bridging carboxylate groups; in the complex with L = cpy (4), by four bidentate-bridging groups. The reaction of [Cd(piv)2] with Et3N in a solution of MeCN gives the centrosymmetric linear trinuclear complex [Cd3(piv)6(Et3N)2] (6); in a mixture of benzene and hexane, the ionic compound (HEt3N)[Cd2(piv)5(H2O)] (7). The crystal structures of all synthesized compounds were determined by X-ray diffraction.

Conditions for chemical assembly of new heterometallic trinuclear pivalates [Cd2M(piv)6L2] (M = Mg, Ca, or Sr; piv is pivalate) were found. Reactions with the nonchelating ligand 2,4-lutidine (lut) gave the crystals of heterometallic complexes [Cd2M(piv)6(lut)2] (M = Mg (1), Ca (2), and Sr (3)). With the chelating ligand 1,10-phenanthroline (phen), only the homometallic dimer [Cd2(piv)4(phen)2] (4) was obtained under these conditions. Yet heterometallic trinuclear complexes with 1,10-phenanthroline ([Cd2Mg(piv)6(H2O)(phen)2] (5), [CaCd2(piv)6(phen)2] (6), and [Cd2Sr(piv)6(phen)2]∙2MeCN (7)) were synthesized by reactions of phen with complexes 1—3. For all the complexes obtained, the molecular and crystal structures as well as the details of their molecular architecture were determined. The thermal behavior of aqua complex 5 was studied by TG and DSC. The complex eliminated the water molecule between 130 and 180 °C with a high endothermic effect (Q = 101 kJ mol–1) due to (1) intramolecular hydrogen bonds that stabilize its molecular architecture and (2) subsequent structural rearrangements.

The results of shear tests on in the presence of adfreeze bonding between frozen soils having different compositions and metal billets coated with protective paints are presented. The investigations showed that the coatings reduce the adfreeze bond strength by 35%, which makes heaving of metal pile foundations less likely.

Two difurazanyl ethers, 3,3′-dinitrofurazanyl ether (FOF-1) and 3,3′-dicyanofurazanyl ether (FOF-2), have been studied in respect of the thermal decomposition, burning behavior, and vapor pressures. The burning rate of the high-energetic FOF-1 has been measured to reach 44 mm/s at pressure of 10 MPa. The temperature distribution in the combustion wave of FOF-1 has been recorded at low pressures, which allows obtaining the dependence of surface temperature on pressure. Vapor pressures and thermal decomposition of FOF-1 and FOF-2 have been studied in isothermal conditions. Analysis of the data obtained shows that combustion of FOF-1 is controlled by gas-phase reactions.

UDC 621.391.822 In this work, we study the spectrum SiD of natural (thermal and shot) current noise of the p-n junction and the Schottky barrier in the case where their current-voltage characteristic has a nonideality coefficient η exceeding unity. The results obtained with the help of a special experimental setup are presented and explained using an equivalent scheme, which takes into account the presence of the series resistance of the diode base and contacts, as well as the possibility of existence of the leakage current. It is theoretically proven and experimentally confirmed that the van der Ziel relation SiD =2 q (ID +2 Is), which is used for calculating the current-noise spectrum of an “ideal” junction with η =1 , cannot be used for η> 1 (here, q is the elementary charge, ID is the current across the junction, and Is is the junction saturation current). The previously obtained results are generalized using the Gupta theorem for the thermal-noise spectrum in the nonlinear resistive systems and are confirmed experimentally. It is found that the noise-current spectrum is given by the formula SiD =( 2 q/η )( ID +2 Is), which is a modification of the van der Ziel relation for the case of an arbitrary value of the nonideality coefficient. The obtained formula for SiD is experimentally tested by measuring the noise spectrum of the δ-doped Schottky diode, which is in thermodynamic equilibrium with the surrounding medium.

The paper presents the calculation of the power combiner of coherent microwave signals. The combiner is based on the Talbot effect in an oversized rectangular waveguide. Parameters of the combiner fed by one source were simulated and experimentally confirmed.

We report on the decomposition of the molecular contribution to the optically heterodyne-detected optical Kerr effect (OHD-OKE) in benzonitrile C6H5CN in the process of double-pulse laser excitation. The pump pulses with linear orthogonal polarizations, controllable intensities and timing enable us to manipulate the amplitudes of various molecular responses due to the fact that the OHD-OKE signal is formed by the superposition of independent third-order responses associated with each pump pulse. We apply this technique to detect the intermolecular response selectively by using an excitation scenario with suppression of orientational and intramolecular responses. A detailed comparative analysis of third-order optical responses indicates strongly that the double-pulse excitation of the OHD-OKE is the useful spectroscopic technique to obtain precise information on the intermolecular spectrum in liquids.

Results of laboratory tests of interaction between models of boring piles and a frozen soil and their comparison with data derived from field tests of boring piles are cited. The physical pattern of the interaction is examined.

A method of measuring the power of subterahertz and terahertz radiation using resonant tunneling diodes is proposed, based on a recording of the change in their current-voltage characteristics. The possibility of extending microwave methods into this radiation band is demonstrated. It is shown that, based on such a diode, one can detect microwave radiation over a wide range of intensities of extremely high-frequency fields.