bluuebunny/crossref_metadata_2025_split huggingface dataset:
HYDROGEN SULFIDE IN NUCLEOPHILIC SUBSTITUTION REACTIONS OF HYDROXY GROUPS IN AROMATIC ALCOHOLS
Authors: Okhlobystina Aleksandra V. , Okhlobystin Andrey O. , Berberova Nadezhda T. , Burmistrova Daria A. 
Published: November 2018

Most methods of obtaining aromatic thiols are based on nucleophilic substitution reactions at halogen derivatives of aromatic hydrocarbons when used as nucleophilic reagents sodium thiolate, thiourea or potassium xanthate at high temperatures, pressure and in the presence of catalysts. The direct reaction of nucleophilic substitution of OH-groups in the phenols, pyrocatechol and benzyl alcohol to the HS-group in conditions of one-electron reducrion of hydrogen sulfide in acetonitrile and pyridinium ionic liquid was investigated for the first time. The proposed reactions proceed at room temperature and atmospheric pressure. The use of "green" solvent - ionic liquid - reduces the syntheses time in а half, improves ecological safety friendliness of the process and reduces the consumption of reagents. The main positive feature of these studies is not only ecological safety of reactions of nucleophilic substitution (due to the lack of harmful byproducts), but the use of electrochemical reactions in ionic liquid media, that is very relevant in modern science in terms of new environmental technologies development.
For citation:
Okhlobystina A.V., Okhlobystin A.O., Berberova N.T., Burmistrova D.A. Hydrogen sulfide in nucleophilic substitution reactions of hydroxy groups in aromatic alcohols. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 9-10. P. 36-41
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Solid-phase concentration of calcium ions with mineral sorbents in creation of anti-icing materials
Authors: Dzhigola Lyudmila A. , Syutova Elizaveta A. 
Published: November 2018

The results of an experimental study of calcium ion adsorption processes carried out on various mineral sorbents of natural origin are presented. The sorption properties of the selected objects were studied and the possibility of their use as combined anti-icing materials was evaluated. In the work were investigated technological indicators of the quality of sorbents - the pH of the zero-charge point, the sorption capacity of sorbents and the optimum pH interval to determine the sorption activity of mineral raw materials on calcium ion. Analysis of the adsorption isotherms of calcium ions by the mineral sorbents studied makes it possible to note that the adsorption equilibrium on the clay is established more rapidly than on the opal of the marl type and marl. At the same time, the maximum absorption capacity of clay and marl has close values, which is related to the structure of the sorbent surface and the mineral composition of the materials. Opal of the marl type has a more developed surface, which is illustrated by a much higher absorption capacity and is confirmed by the values of the specific surface area. The obtained experimental data were processed using Freundlich, Langmuir, Temkin, and Dubinin-Radushkevich models. When describing the adsorption equilibrium of calcium ions on mineral sorbents, the Freyndlich isotherm is a more rigorous model, which indicates the presence of a large number of active centers and their exponential distribution on the surface of sorbents. The quantitative characteristics of the adsorption capacity of sorbents, found by adsorption models, made it possible to identify the optimum conditions of processes, establish a relationship between the values of the sorption of calcium ions by their structure and the porosity of the materials. It has been established that opal of marl type is the most effective carrier for producing anti-icing materials.
For citation:
Dzhigola L.A., Syutova E.A. Solid-phase concentration of calcium ions with mineral sorbents in creation of anti-icing materials. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 9-10. P. 98-104
APPLICATION OF ADSORPTION MODELS FOR DESCRIPTION OF BALANCES IN THE SYSTEMS «CATIONS OF COPPER (II) AND LEAD (II) – NATURAL MATERIALS OF ASTRAKHAN REGION »
Authors: Dzhigola Lyudmila A. , Sadomtseva Olga S. , Shakirova Victoria V. , Kargina Kristina V. , Syutova Elizaveta A. , Razgovorov Pavel B. , Nagornov Roman S. 
Published: November 2018

I
In the work there were studied the regularities of extracting copper (II) and lead (II) cations from aqueous solutions with the help of natural sorbents from the Astrakhan region such as the marl of the Baskunchak deposit, the Kamennyy yar deposit and the clay of the Volzhsky deposit. A comparative study was made of the applicability of the adsorption models of Langmuir, Freindlich, Temkin, and Dubinin-Radushkevich to describe the experimental adsorption isotherms of these cations on the surface of aluminosilicates. The constants and parameters of the equations corresponding to these models are determined. A comparison of the regression coefficients shows that the Temkin model is suitable for describing the adsorption equilibria in the "M2+ -clay" systems. The Freundlich model most adequately describes the experimental data on adsorption in the "M2+ -marl/opoka" systems, which reveals the heterogeneous surface of both of these materials with a large number of energetically dissimilar active centers. The regression coefficients found in this case by the Langmuir model are small; the boundary conditions for the description of systems with a monomolecular coating are not observed. The Dubinin-Radushkevich model was also used to describe the process of concentrating lead (II) compounds on the marl surface of the Baskunchak deposit and the Kamennyy Yar deposit. The calculated values of the free energy of adsorption were 11.2 (opoka) and 4.17 kJ/mol (marl). The process of fixing lead cations on these natural sorbents in the Astrakhan region proceeds according to the ion-exchange mechanism. The adsorption activity of Cu2+, Pb2+ ions on the surface of sorbents is confirmed by the calculated values of Gibbs energy and entropy. The endothermic nature of the processes taking place with the participation of the clay of the Volzhsky deposit and the Kamennyy Yar deposit is explained by the considerable energy expenditure for the dehydration of the surface groups of sorbents.
For citation:
Dzhigola L.A., Sadomtseva O.S., Shakirova V.V., Kargina K.V., Syutova E.A., Razgovorov P.B., Nagornov R.S. Application of adsorption models for description of equilibria in systems cations of copper (II) and lead (II) – natural materials of Astrakhan region. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 9-10. P. 105-112
HYDROGEN PRESSURE, SOLVENT AND CATALYST NATURE INFLUENCE ON THE 2-CHLORO-4-NITROANILINE HYDROGENATION REGULARITIES
Authors: Klimushin D.M. , Krasnov A.I. , Filippov D.V. , Sharonov N.Yu. 
Published: November 2018

The 2-chloro-4-nitroaniline liquid-phase hydrogenation kinetics on supported palladium and platinum catalysts differing in the nature of the carrier and the active metal content was studied for the first time. The experiment was carried out at elevated hydrogen pressures in the range of 9 - 12 atm and 303 K in solvents 2-propanol-water and ethyl acetate in the reactor such as Vishnevsky autoclave. The main kinetic parameters of the reaction have been determined, and the influence of various parameters on the regularities of the process has been established. It is shown that an increase in the active metal content in the catalyst leads to an increase in the rate of the hydrogenation reaction of 2-chloro-4-nitroaniline. When using platinum supported catalysts, the rate of hydrogenation of 2-chloro-4-nitroaniline is significantly higher than when using supported palladium catalysts. The replacement of the liquid phase of the catalyst system with 2-propanol by ethyl acetate adversely affects the reaction rate. The influence of the catalytic system nature and composition on the target product dehalogenation degree was determined. It was found that when carrying out the reaction at elevated hydrogen pressures, it is preferable to use low-percentage platinum catalysts, rather than palladium catalysts, since the former provide less dehalogenation of the target product.
For citation:
Klimushin D.M., Krasnov A.I., Filippov D.V., Sharonov N.Yu. Hydrogen pressure, solvent and catalyst nature influence on 2-chloro-4-nitroaniline hydrogenation regularities. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 9-10. P. 30-35
STABILITY OF COORDINATION COMPOUNDS OF SOME d-METAL IONS WITH SUCCINIC ACID ANION IN AQUEOUS-ETHANOL SOLVENTS
Authors: Tukumova Natalia V. , Usacheva Tatiana R. , Thuan Tran Thi Dieu , Sharnin Valentin A. , Giancola Concetta 
Published: November 2018

The paper provides an overview of own data on complexation of nickel (II), cobalt (II) and cooper (II) ions with succinic acid anion in water-organic mixed solvents. Proper data are compared with data reported in literature for d-metal complexes with anions of maleic and succinic acids. The effect of aqueous ethanol solvent compositions on the stability of coordination compounds of M2+ with succinic acid anion as well as on рК values of stepwise succinic acid dissociation was carried out by a potentiometric titration at ionic strength of 0.1 maintained with sodium perchlorate at 298.15 ± 0.10 K. Mono ligand complexes of Ni2+, Co2+ and Cu2+ ions with succinic acid anion become stronger when ethanol content rises. In aqueous solutions Cu2+ ion forms stronger complexes with succinic and maleic acid anions than Ni2+ and Co2+ ions. In the studied water - ethanol solution this ratio is maintained for complexes with succinic acid anion, but a water-isopropanol solvent exerts leveling effect on the stability of complexes of nickel (II) and cobalt (II). An increase in the stability of complexes of d-metal with anions of maleic and succinic acids is due to the destabilization of the ligand with increasing ethanol concentration. The principal contribution of the changes in the solvation state of ligand is a typical for the stability changes of d-metal complexes with amine, glycinate, and acetate type ligands in water-organic mixed solvents.
For citation:
Tukumova N.V., Usacheva T.R., Thuan Tran Thi Dieu, Sharnin V.A., Giancola C. Stability of coordination compounds of some d-metal ions with succinic acid anion in aqueous-ethanol solvents. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 9-10. P. 15-22
SYNTHESIS OF MAGNETIC NANOPARTICLES FROM SPENT PICKING LIQUORS IN AQUEOUS SATURATED SOLUTION OF CALCIUM HYDROXIDE
Authors: Vu Minh X. , Le Ha T. T. , Pham Lan T. , Pham Nam H. , Le Huong T. M. , Le Lu T. , Nguyen Dung T. 
Published: November 2018

Spent pickling liquor is a considered hazardous waste because of its very high level of acidity and high metal concentration, and the conventional neutralization method regenerates an excessive quantity of sludge that poses a serious problem concerning to the landfill disposal and risk of ground water contamination. Therefore, recovery of spent pickling liquor is necessary. Several approaches have been investigated for spent pickling liquor recovery, but they are generally costly and lead to produce various iron salts or oxides which have a limited value. In the present study, we explore the potential of using spent pickling liquor as iron precursor for the synthesis of magnetic nanoparticles. Here, Fe3O4 nanoparticles were prepared easily by oxidation-precipitation from spent hydrochloride acid pickling liquors in aqueous saturated solution of calcium hydroxide at room temperature, in the air, and under suitable speed of rotation. The FT-IR, XRD and TEM results shown that monodisperse Fe3O4 nanoparticles in the size range of 10-25 nm were obtained, with a high level of crystallinity. The BET surface area was about 46 m2 g-1. The synthesized Fe3O4 nanoparticles exhibited the superparamagnetic behavior with relatively high saturation magnetization, Ms = 73 emu/g. The synthesis procedure of magnetic nanoparticles revealed here will provide a new possibility for spent pickling liquors recovery more effectively.
For citation:
Vu Minh X., Le Ha T. T., Pham Lan T., Pham Nam H., Le Huong T. M., Le Lu T. Nguyen Dung T. Synthesis of magnetic nanoparticles from spent picking liquors in aqueous saturated solution of calcium hydroxide. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 9-10. P. 59-63
Distributed adaptive neural consensus tracking control of MIMO stochastic nonlinear multiagent systems with actuator failures and unknown dead zones
Authors: Wu Zumin , Wu Yuefei , Yue Dong 
Published: November 2018

SummaryThis paper focuses on the leader‐following consensus control problem of stochastic multiagent systems with unknown input dead‐zone nonlinearity, unknown actuator failures, and nonlinear dynamics. A distributed adaptive neural consensus tracking controller is presented for stochastic multiagent systems directions under directed graphs, which can achieve predefined synchronization error bounds. By mainly activating an auxiliary robust control component for pulling back the transient escaped from the neural active region, a multiswitching robust neuroadaptive controller in the neural approximation domain can achieve globally uniformly ultimately bounded tracking stability of multiagent systems recently. By constructing a smooth dead‐zone inverse and applying the dynamic surface control technique, distributed consensus controllers are developed to guarantee that the trajectories of synchronization error converge to a small neighborhood of the origin. Two simulation examples are provided to illustrate the effectiveness and advantage of the proposed control scheme.
Personalized Hydrogels for Engineering Diverse Fully Autologous Tissue Implants
Authors: Edri Reuven , Gal Idan , Noor Nadav , Harel Tom , Fleischer Sharon , Adadi Nofar , Green Ori , Shabat Doron , Heller Lior , Shapira Assaf , Gat‐Viks Irit , Peer Dan , Dvir Tal 
Published: November 2018

AbstractDespite incremental improvements in the field of tissue engineering, no technology is currently available for producing completely autologous implants where both the cells and the scaffolding material are generated from the patient, and thus do not provoke an immune response that may lead to implant rejection. Here, a new approach is introduced to efficiently engineer any tissue type, which its differentiation cues are known, from one small tissue biopsy. Pieces of omental tissues are extracted from patients and, while the cells are reprogrammed to become induced pluripotent stem cells, the extracellular matrix is processed into an immunologically matching, thermoresponsive hydrogel. Efficient cell differentiation within a large 3D hydrogel is reported, and, as a proof of concept, the generation of functional cardiac, cortical, spinal cord, and adipogenic tissue implants is demonstrated. This versatile bioengineering approach may assist to regenerate any tissue and organ with a minimal risk for immune rejection.
Balancing Scattering Channels: A Panoscopic Approach toward Zero Temperature Coefficient of Resistance Using High‐Entropy Alloys
Authors: Shafeie Samrand , Guo Sheng , Erhart Paul , Hu Qiang , Palmqvist Anders 
Published: November 2018

AbstractDesigning alloys with an accurate temperature‐independent electrical response over a wide temperature range, specifically a low temperature coefficient of resistance (TCR), remains a big challenge from a material design point of view. More than a century after their discovery, Constantan (Cu–Ni) and Manganin (Cu–Mn–Ni) alloys remain the top choice for strain gauge applications and high‐quality resistors up to 473–573 K. Here, an average TCR is demonstrated that is up to ≈800 times smaller in the temperature range 5–300 K and >800 times smaller than for any of these standard materials over a wide temperature range (5 K < T < 1200 K). This is achieved for selected compositions of AlxCoCrFeNi high‐entropy alloys (HEAs), for which a strong correlation of the ultralow TCR is established with the underlying microstructure and its local composition. The exceptionally low electron–phonon coupling expected in these HEAs is crucial for developing novel devices, e.g., hot‐electron detectors, high‐Q resonant antennas, and materials in gravitational wave detectors.
Recent Advances in Smart Wearable Sensing Systems
Authors: Lou Zheng , Wang Lili , Shen Guozhen 
Published: November 2018

AbstractWearable technology with widespread public attention has generated tremendous economic and social impact, resulting in changes in healthcare procedures and personal lifestyle. Smart wearable sensing systems, as an important type of device in wearable technology which can detect various stimuli relevant to biological species or specific environments, have recently seen a large increase in both commercialization and research. Over the past few years, the research direction in this field has focused mainly on the development of flexible, lightweight, self‐powered, miniaturized, and integrated wearable systems. The recent progress and advantages of smart wearable sensing systems for their use in practical electronic applications are summarized herein. An overview of different strategies for smart wearable sensing systems, such as flexible/stretchable substrate and conductors, active materials, wireless communication and displays, and power supplies, is presented. Moreover, the potential applications and challenges of the smart sensing systems are briefly discussed and highlighted.
Ion Therapy: A Novel Strategy for Acute Myocardial Infarction
Authors: Yi Min , Li Hekai , Wang Xiaoya , Yan Jianyun , Gao Long , He Yinyan , Zhong Xinglong , Cai Yanbin , Feng Weijing , Wen Zhanpeng , Wu Chengtie , Ou Caiwen , Chang Jiang , Chen Minsheng 
Published: November 2018

AbstractAlthough numerous therapies are widely applied clinically and stem cells and/or biomaterial based in situ implantations have achieved some effects, few of these have observed robust myocardial regeneration. The beneficial effects on cardiac function and structure are largely acting through paracrine signaling, which preserve the border‐zone around the infarction, reduce apoptosis, blunt adverse remodeling, and promote angiogenesis. Ionic extracts from biomaterials have been proven to stimulate paracrine effects and promote cell–cell communications. Here, the paracrine stimulatory function of bioactive ions derived from biomaterials is integrated into the clinical concept of administration and proposed “ion therapy” as a novel strategy for myocardial infarction. In vitro, silicon‐ enriched ion extracts significantly increase cardiomyocyte viability and promote cell–cell communications, thus stimulating vascular formation via a paracrine effect under glucose/oxygen deprived conditions. In vivo, by intravenous injection, the bioactive silicon ions act as “diplomats” and promote crosstalk in myocardial cells, stimulate angiogenesis, and improve cardiac function post‐myocardial infarction.
Design of Single‐Molecule Multiferroics for Efficient Ultrahigh‐Density Nonvolatile Memories
Authors: Yang Qing , Zhong Tingting , Tu Zhengyuan , Zhu Lin , Wu Menghao , Zeng Xiao Cheng 
Published: November 2018

AbstractIt is known that an isolated single‐molecule magnet tends to become super‐paramagnetic even at an ultralow temperature of a few Kelvin due to the low spin switching barrier. Herein, single‐molecule ferroelectrics/multiferroics is proposed, as the ultimate size limit of memory, such that every molecule can store 1 bit data. The primary strategy is to identify polar molecules that possess bistable states, moderate switching barriers, and polarizations fixed along the vertical direction for high‐density perpendicular recording. First‐principles computation shows that several selected magnetic metal porphyrin molecules possess buckled structures with switchable vertical polarizations that are robust at ambient conditions. When intercalated within a bilayer of 2D materials such as bilayer MoS2 or CrI3, the magnetization can alter the spin distribution or can be even switched by 180° upon ferroelectric switching, rendering efficient electric writing and magnetic reading. It is found that the upper limit of areal storage density can be enhanced by four orders of magnitude, from the previous super‐paramagnetic limit of ≈40 to ≈106 GB in.−2, on the basis of the design of cross‐point multiferroic tunneling junction array and multiferroic hard drive.
A Robust Artificial Synapse Based on Organic Ferroelectric Polymer
Authors: Tian Bobo , Liu Lan , Yan Mengge , Wang Jianlu , Zhao Qingbiao , Zhong Ni , Xiang Pinghua , Sun Lin , Peng Hui , Shen Hong , Lin Tie , Dkhil Brahim , Meng Xiangjian , Chu Junhao , Tang Xiaodong , Duan Chungang 
Published: November 2018

AbstractMemristors with history‐dependent resistance are considered as artificial synapses and have potential in mimicking the massive parallelism and low‐power operation existing in the human brain. However, the state‐of‐the‐art memristors still suffer from excessive write noise, abrupt resistance variation, inherent stochasticity, poor endurance behavior, and costly energy consumption, which impedes massive neural architecture. A robust and low‐energy consumption organic three‐terminal memristor based on ferroelectric polymer gate insulator is demonstrated here. The conductance of this memristor can be precisely manipulated to vary between more than 1000 intermediate states with the highest OFF/ON ratio of ≈104. The quasicontinuous resistive switching in the MoS2 channel results from the ferroelectric domain dynamics as confirmed unambiguously by the in situ real‐time correlation between dynamic resistive switching and polarization change. Typical synaptic plasticity such as long‐term potentiation and depression (LTP/D) and spike‐timing dependent plasticity (STDP) are successfully simulated. In addition, the device is expected to experience 1 × 109 synaptic spikes with an ultralow energy consumption for each synaptic operation (less than 1 fJ, compatible with a bio‐synaptic event), which highlights its immense potential for the massive neural architecture in bioinspired networks.
Mass transfer effects on biodegradation of methylene blue by immobilized cell in a packed bed bioreactor
Authors: Habibi Alireza , Narimani Rad Khatere 
Published: November 2018

AbstractAerobic degradation of methylene blue by a pure culture of Ralstonia eutropha was studied by both freely suspended cells and kissiris‐immobilized packed bed reactors. Kissiris as a cell support matrix favored the retention of the cells in the packed bed reactor during of the methylene blue biodegradation process. The biodegradation experiments showed that the kissiris‐packed bed reactor had higher performance in removal of the dyestuff for initial concentrations equal or higher than 150 mg L−1 when compared with the freely suspended cells. To evaluate the effect of mass transfer phenomena in the immobilized system, mass balance of methylene blue for a single kissiris piece was applied to derive expressions correlating the methylene blue concentration in the bulk liquid medium and inside of the bioparticle. Kinetics studies revealed a self‐inhibitory effect of methylene blue on its biodegradation at concentrations higher than 85.76 mg L−1 in the free cell and 190.1 mg L−1 for immobilized system. The mass transfer modeling indicated the protective role of the support from cells against the inhibitory role of methylene blue is related to both external and internal mass transfer limitations in the immobilized system. In the kissiris packed bed reactor, the effectiveness value was higher than unity for initial methylene blue concentration of 150 mg L−1.