bluuebunny/crossref_metadata_2025 huggingface dataset:
Some features of crustacean cultivation aquabiotechnology on the waters of energy facilities
Authors: Kalaida Marina , Khamitova Madina , Borisova Svetlana
Published: July 2021

The data on the state of the crayfish population on the territory of the Middle Volga before its regulation and after the formation of reservoirs are presented. Three stages in the state of development of aquabiotechnology of the crustaceans cultivation in the Middle Volga region have been identified. The first stage is before regulation of the Volga river. The second stage is pasture aquaculture in reservoirs with works on the targeted improvement of aquatic ecosystems. It is shown that the size-weight and ecological-biological characteristics of long-clawed crayfish before the regulation of the river and after the formation of the Kuibyshev reservoir are similar. The third stage is highlighted in connection with the expansion of biotechnologies for growing thermophilic crayfish in recirculating aquaculture systems. At the present stage, in the Kuibyshev and Nizhnekamsk reservoirs, there are narrow-clawed (Pontastacus leptodactylus Esch.) and wide-clawed crayfish (Astacus astacus L.). The catches contain crayfish of three ages: two-year-olds - about 100 mm, three-year-olds - about 150 mm, four-year-olds - about 170 mm long. The equation for the dependence of body weight on the zoological length of narrow-clawed crayfish in the Kuibyshev reservoir: y = 0.67x +81.3. The cultivation of the red claw crayfish Cherax quadricarinatus (VonMartens, 1868) on the warm waters of energy facilities can become an important element of aquaculture for the production of elite gourmet products. The equation for the dependence of body weight on the zoological length of red claw crayfish in a recirculating aquaculture system: y = 1.1x +57.3. The development of aquatic biotechnologies makes it possible to use natural crayfish populations for the creation of crayfish farms and pasture aquaculture on the basis of reservoir waters, and the use of warm waters makes it possible to grow new aquaculture objects for the industrial crayfish cultivation all year round. At the same time, natural ecosystems are not disturbed, and the rate of growth of marketable products under controlled production conditions allows not only to increase the volume of aquaculture products, but also to reduce the pressure of catch of crayfish from natural ecosystems.
Investigation of resonance phenomena in power lines supplying powerful rectifier plants
Authors: Molot Svetlana , Kovalenko Vasilina , Pylskaya Elena , Artyukhov Ivan , Stepanov Sergey
Published: July 2021

A feature of modern power supply systems is the presence of a large number of electrical devises that consume non-sinusoidal current. The examples of the devices are frequency converters or rectifiers of large unit power. But substations for supplying a group of variable frequency drives affect negatively also. Since the equivalent circuit of the power includes line inductive and capacitive elements, under certain conditions, resonant can occur in the power supply system. The model for studying a power supply system with a powerful rectifier load has been developed in the MATLAB + Simulink environment. The equivalent power line circuit is adopted in the form of a certain number of series-connected sections. The number of sections was chosen from the condition of obtaining information about all harmonics, which the electric power quality standard prescribes to analyze. The simulation results show the number of the harmonic at which the resonance occurs depends on the length of the power line. It has been found that at resonance, the maximum current harmonic circulates through the source. And at the end of the line in this moment, the current harmonic has a minimum value, while the corresponding voltage harmonic rises sharply.
Investigation of the components nature and concentration influence on carbon dioxide equilibrium in the system CaCl2-Na2CO3-NaOH-H2O by potentiometric titration
Authors: Gilfanov Bulat , Chichirov Andrey , Chichirova Natalia
Published: July 2021

The modern thermal power plants equipment requires strict deposits control on the surfaces. Such deposits are formed from impurities entering the cycle with water, the amount of which has significantly increased at modern powerful thermal power plants. At the modern level of the coolant water treatment, it is possible to exclude most of the impurities responsible for salt deposition. Analysis of various types of the sediments has shown that carbonate deposits are an integral part of them. Modern research methods (potentiometric titration in combination with methods of mathematical modelling) for carbonate, silicate, phosphate water systems have shown the existence of phase-unstable states leading to salt deposition during the coolant circulation. In this article, the carbonate system CaCl2-Na2CO3-NaOH-H2O was studied by potentiometric titration with a glass indicator electrode. The influence of the components nature (Li2CO3, Na2CO3, Ca2CO3, LiOH, NaOH, KOH, CaCl2, MgCl2) and the conditions for the existence of phase-unstable systems with varying concentrations of these components were studied. It is known that organic phosphonates are effective inhibitors of deposits in the carbonate system. In this paper, the action of two compounds of the specified class is considered. The concentration limits of their inhibitory action have been determined.
Study of the State of Surface Waters of the Northeast Caspian Sea During Development of Oil Fields
Authors: Kenzhegaliyev A. , Kulbatyrov D.K. , Kanbetov A.Sh. , Shakhmanova A.K. , Abilgaziyeva A.A.
Published: July 2021

The relevance of the research is due to the fact that the Kashagan field has resumed oil and gas production, and up to this date more than 40 million tons of oil have been produced. In this regard, the study of the state of pollution of surface waters and its dynamics is relevant. This article is aimed at detecting the state of contamination with biogenic elements, oil products, phenol, synthetic surfactants and heavy metals. The leading approach to the study of this problem is State Standard 17.1.5.04-81; The seawater sampling procedure is carried out in accordance with ISO 5667-9: 1992 and ISO 5667-2. The article presents the results of research conducted in 2019 and the dynamics of pollution with pollutants in the area of the Kashagan, Kairan and Aktoty fields in the licensed territory. At the Kashagan field, samples were taken from 14 observation stations for the study. The fields of Kairan and Aktoty are currently preserved. In this regard, 2 observation stations were studied at each of these deposits and the results were compared with the results of the previous year. Based on the data obtained, it was revealed that biogenic elements remained at the same level and below the maximum permissible concentration for the entire study period. Comparison with last years’ studies shows that in 2019, the concentration of biogenic elements was lower than 2018. The content of oil products and synthetic surfactants for the study period was higher than in 2018, but lower than the MPC for the fisheries reservoir, and the phenol content was at the level of 2018 and exceeds the maximum permissible concentration by 3 times. Heavy metals for the entire study period were at the same level, with the exception of copper and iron, the concentration of which is higher than in 2018, but less than the MPC. The materials of the article are of practical value for scientists engaged in the study of the state of the inland seas, undergraduates, doctoral students.
Digital transformation of the energy industry in the Russian economy
Authors: Galeeva Gulnaz
Published: July 2021

This study analyzes the reasons, factors and prerequisites for the development of digitalization processes in the energy industry in Russia. An overview of the Digitalization Strategy of the Russian industry, its priority goals and objectives is presented. Based on the analysis of the Energy Strategy of Russia until 2035, the main problems and threats to the development of the industry are highlighted. Among the tasks of digitalization of the energy industry in Russia, priorities are outlined: working with big data, increasing the efficiency of asset use, transforming the model of interaction with customers, optimizing the system of electricity management and distribution. The article, based on the data of the Ministry of Energy of the Russian Federation and information posted on the official websites of energy companies, collected and analyzed material on the role of digital technologies and the dynamics of their implementation in the energy complex of Russia. Energy policy priorities vary from country to country, but the role of digital technology is widely recognized. In conclusion, conclusions are drawn about the expected effects of the introduction of digital technologies in the field of operational safety of energy infrastructure facilities, an increase in the technical level of energy systems and a reduction in losses.
Design of the Heat Pipe Helium Greenhouse for the Effective Use of the Soil Heat
Authors: Matyakubov Amirhan , Saryyev Kakageldi , Nazarov Serdar , Gurbanova Gulshat
Published: July 2021

This scientific work presents the results of scientific research on the use and accumulation of solar energy for heat supply of a solar greenhouse. For a real assessment of the problem, the following information can be cited as an example: in a greenhouse with a total area of 234 m2 covered with polyethylene film must be installed, on the average, with 6-8 furnaces to provide a certain amount of warm air. One furnace consumes about 2448 m3/h of natural gas for four months, and during this time 8.6 kg of carbon dioxide (CO2) is emitted from one furnace. As a result, taking into account the payment for the consumption of natural gas, the problem of the cost of the obtained products, energy conservation, and also environmental protection is very urgent. To solve this problem, a solar greenhouse with an additional heating chamber was constructed at the research site of the State Energy Institute of Turkmenistan. In this structure, excess of solar and heat energy of the soil was accumulated in mountain stones, and carbon dioxide that emits soil (horse manure was used as a soil) was used to feed the Chlorella vulgaris suspension grown in the photobioreactor, which in its turn had a beneficial effect on its cultivation. To transfer heated air from the additional heating chamber to the solar greenhouse and the accumulated thermal energy of the soil, polyethylene pipes with holes were used. Due to the use of the heat capacity of the materials (rock stones), a two-layer coating of the structure, compaction of the northern side with wool and accumulated heat energy, it was possible to achieve a positive temperature in the solar greenhouse in the minus environmental values. The technologies and processes considered in this research are mainly renewable energies and technical (chemical reactions) solutions such as photovoltaic (PV) modules, phase exchange material (PCM), underground heat storage technologies, energy efficient heat pumps and facade materials for the better heat insulation. The obtained results of the research work can be applied in solar greenhouses, the construction of which is planned in the areas remote from the central power supply network, since heat supply is carried out using solar energy and electric lighting is implemented due to the solar panels with a built-in LED lamp. It should be borne in mind that the intensity of solar radiation on the territory of Turkmenistan fluctuates in the range of 700-800 W/m2, which indicates the huge possibilities of using solar energy.
Study of the electrophysical properties of nanostructured porous germanium as a promising material for electrodes of electrochemical capacitors
Authors: Platonov Nikolay , Suleimanov Nail , Bazarov Valery
Published: July 2021

Electrochemical capacitors (ECC) are a fast charging devices, with high power density, capacity and increased life time. Nanostructured semiconductors are now considered as the promising materials for electrodes of such devices due to its conductive properties and effective surface. One of such materials is the porous germanium which can be used as an electrode in electrochemical capacitors. In this article the novel approach based on the method of ion implantation was developed to grow these structures. This method allows to obtain a structures up to 1 μm thick. The object of this work was the investigation of the electrophysical characteristics of samples of nanostructured porous germanium (Ge) depending on the implantation dose and surface morphology. The scientific novelty of this research lies in the search the structures with the highest effective surface area and electronic conductivity, capable of multiplying the energy capacity and specific power of ECC. Methods: The samples of amorphous Ge were grown on dielectric single-crystal substrates of Al2O3. The thickness of samples was 600 and 1000 nm. The magnetron sputtering and ion implantation methods were used to growth these structures. The irradiation with Ge+ ions produced with an energy of 40 keV and the range of implantation doses varied from 2·1016 to 12•1016 ion / cm2. The study of electrical properties was carried out on the Hall installation HL55PC at the NPP KVANT in Moscow. The following parameters were measured: the sheet concentration of carriers in the near-surface layer, electrical resistance, mobility of the charge carriers, Hall coefficient. As a result, the dependences of carriers concentration and their mobility as the function of the implantation dose and thickness of the samples of nanostructured porous germanium were determined, and the results were analyzed. Results: It was found that ion implantation of single-crystal germanium leads to an increase in the carrier concentration in the near-surface layer. To sum up, the most suitable material as an electrode for ECC is the porous germanium with the maximum dose of ion implantation and the largest thickness. The maximum sheet carrier concentration that was obtained in the study for Ge is 1017 cm-2.
Directions Of Hydrogen Power Development In Tatarstan Republic
Authors: Filimonova Antonina , Chichirov Andrey , Chichirova Natalya , Filimonov Artem , Pechenkin Alexandr
Published: July 2021

Green hydrogen is a promising solution for a decarbonized energy system, and in 2020 the use of hydrogen has increased dramatically around the world. In order to draw attention to the problem of hydrogen energy in Russia and the Republic of Tatarstan, the article analyzes the development paths and main opportunities for the production, transportation, and use of hydrogen at the enterprises of Tatarstan, and calculates the economic efficiency of the “green” hydrogen production by electrolysis at TPPs with CCGTs in Tatarstan. METHODS. Research methods are based on the analysis of literature data and mathematical calculations. RESULTS. Tatarstan, as one of the leading economically developed regions of Russia, could take part in the “green” hydrogen production, the electrochemical equipment design for its production, the development of technologies for the fuel cells use, research and training of highly qualified specialists in the field of hydrogen energy. According to the calculations, the production of the most environmentally friendly hydrogen at TPPs with CCGT in Tatarstan will currently cost an average of 2 euros per kilogram, which is significantly lower than the existing market value. CONCLUSION. Tatarstan can become a competitive region for the “green” hydrogen production and distribution. The main areas of activity should be the pure hydrogen production, the industrial production of freight transport on fuel cells, the production of megawatt-class electrolysers, the utilization of hydrogen-containing petroleum gases at TPPs in gas turbines or in combined cycle power plants with fuel cells.
The Republic of Bashkortostan as an experimental test site for the production of artificial hydrocarbons
Authors: Fedorova Olga
Published: July 2021

The shifting of the oil extraction industry to the remote areas that are far from the regions with a developed petrochemical and oil refining industry implies high risks for the economic development of the latter. In the future, these enterprises may face risks of raw materials supply. So, some measures are needed to smooth out the spatial polarization of the territory in the future. For the transformation of the region’s economy, it is proposed to present the Republic of Bashkortostan as an experimental test area for the artificial hydrocarbons production for the further production of an expanded range of commercial products, including composite propellant (mixed fuel). The potential participants of the experiment are discussed in the article. For example, Chishminsky Oil Extraction Plant, which recently produces rapeseed oil and exports to the countries of the European Union and China for the production of biodiesel. For the production of ethanol, it is also proposed to use the production facilities of “Bashspirt”, located in the region. At the production site of such enterprises as the Branch of “Bashneft”, it is possible to produce various nomenclature of commercial products based on oil in concentration with artificial hydrocarbons from vegtative raw materials.
Improvement of the gas chromatographic method for diagnosing developing defects in oil-filled electrical equipment based on the analysis of furan compounds
Authors: Vu Ngoc Dan , Taneeva Alina Vyacheslavovna , Novikov Vyacheslav Fedorovich
Published: July 2021

During the operation of oil-filled electrical equipment under the influence of temperature, humidity and other negative factors, the destruction of paper insulation occurs. As a result of this destruction, furan compounds are formed, which get into the transformer oil. To identify the process of destruction of paper insulation, control of furan compounds in transformer oil is carried out by instrumental methods. Of these methods, the most widely used is gas chromatography using packed chromatographic columns, on the basis of which guidelines have been developed. To improve gas chromatographic methods for monitoring furan compounds, we used a highly efficient quartz capillary column filled with a polar stationary phase based on polyethylene glycol. The sample was injected into the injector of the chromatograph Chromos-GC1000 using an automated dosing system with a vial for 23 samples. Used transformer oil of the GK-1 brand of Almetyevsk electrical networks was taken as the object of research; The optimal retention characteristics of standard sorbates were preliminary determined, which were used as organic extractants of transformer oil and furan compounds. The effect of temperature on the process of chromatographic analysis of furfuryl alcohol and organic extractants was determined, on the basis of which it was established that the selectivity of separation is determined by the nature of intermolecular interactions in the sorbate-sorbent system, in particular, the formation of a hydrogen bond. It has been shown that the selectivity coefficient for the separation of furfuryl alcohol depends on the physicochemical nature of organic extractants, their boiling points and dipole moments and has the highest values for the analyzed pair of components: furfuryl alcohol - ethanol.
The mathematical model and a block diagram of a synchronous motor compressor unit with a system of automatic control of the excitation
Authors: Toirov Olimjon , Kamalov Tulyagan , Mirkhonov Utkir , Urokov Sardor , Jumaeva Dilnoza
Published: July 2021

The general requirements for the automatic excitation control system of synchronous motors of a compressor unit are shown, taking into account its operating modes. A mathematical model is presented, a block diagram of the excitation circuits of a synchronous motor of a compressor unit and an exciter, which characterizes the feedback of the internal properties of this part of the system in dynamics. A block diagram of a closed-loop automatic excitation control system is obtained, taking into account the elasticity of the mechanical part and a hard blow in the compressor gas pipeline. The obtained structural diagrams make it possible to determine the transfer functions of the considered system in terms of control and disturbing influences, the characteristic equation, as well as the dependencies of various frequency characteristics, which make it possible to investigate the dynamic indicators (stability, control quality, etc.) of the system.
Use of vertical geothermal heat exchanger with nanofluid for heat supply systems
Authors: Sednin Alexei , Mukhin Aliaksandr , Balakin Boris
Published: July 2021

Future district heating systems need to be more flexible and move towards a carbon-neutral generation. Compression heat pumps are foreseen to be promising future tools for district heating systems in EU countries. The paper presents the simulation data or a vertical double-pipe geothermal heat exchanger with ethylene glycol-Al2O3 as a working fluid. To simulate the operation of the heat exchanger, the STAR-CCM + CFD application was used. It has been determined the optimal volume particle concentrations of nanofluid and enhance of heat exchanger performance.
Research on the issue of using the heat of combustion products for heat supply of greenhouses
Authors: Nazarov Serdar , Rakhimov Muhammetberdi , Hojageldiyev Saparmyrat
Published: July 2021

Cultivation of agricultural crops in winter season is carried out in special greenhouses. For heating greenhouses, a huge amount of heat energy is consumed. In the conditions of Turkmenistan, up to 1500 tons of standard fuel per year is consumed to heat the greenhouse with an area 1 hectare. The increase in heating costs leads to an increase in the prices of grown products. Therefore, saving fuel energy in the greenhouses is one of the most important economic factors. Possibilities of using the heat of the combustion products of steam boilers at the Mary State Electric Power Station (Turkmenistan) for heating greenhouses are discussed in the article. For this purpose, a special contact heat exchanger is installed on the line of the outgoing combustion products of steam boilers. In the experimental facilities, water is injected from top to bottom, and combustion products move in the opposite direction. In this case, the temperature of the combustion products decreases from 120-150 °C to 30-40 °C. The temperature of the cooling water of the combustion products rises from 10-20 °C to 40-45 °C. To increase the contact surface of water and gas in a contact heat exchanger, spray-type layer conductor is used. A distinctive feature of the experimental facility is the use of local materials as a spray-type layer with a conductor. For subsoil heating of greenhouses, water is supplied with the temperature of 40 °C, and for the raise of the vegetables grown in them water is supplied with the temperature of 22-25 °C. The use of the heat of combustion products to heat greenhouses is of great importance both for saving fuel and for purifying the environment from harmful emissions.
A review on modern heat-insulating materials for improving the energy efficiency of buildings and life-support utilities
Authors: Karpov Denis , Dyudina Olga , Pavlov Mikhail
Published: July 2021

The main heat engineering characteristics of modern traditional and innovative heat-insulating materials, their advantages, and application fields are considered. Particular attention is paid to liquidceramic heat-insulating materials - thermal paints, which are now actively used for thermal insulation of facades of capital and completed construction projects, engineering and technical life support systems, installations, and separate elements. Interest in the study of this group of building materials is explained by the widespread use of heaters to improve the energy efficiency of civil and industrial buildings, as well as engineering life support systems for various purposes.
Modeling of operating modes of relay protection in electrical networks with insulated neutral
Authors: Aluynov A. , Vyatkina O. , Gracheva E. , Nemirovskiy A.
Published: July 2021

This work aims to study relay protection and automation in insulated neutral networks to identify additional criteria for choosing the type of earthing. To calculate the single-phase earth fault currents as a function of the operating modes of the electrical substation, the 10 kV network of the electrical substation was simulated in the software package. The advantages and disadvantages of centralized and non-centralized protections are shown. The paper presents the sequence of actions necessary for the correct operation of directional zero sequence protection.
Study of unsteady thermal conductivity in a multilayer rubber-metal product during post-vulcanization cooling and after-vulcanization
Authors: Kochkareva Tatyana , Zaripova Daniya , Sinitsyn Anton
Published: July 2021

The article considers analytical solutions for a non-stationary problem of heat and mass transfer in a multilayer elastomeric material. Determined are the criteria, influence the process of temperature change in the treated material. A functional relationship between the main criteria of heat transfer and the temperature of the processed material was established, which is the basic relation during the development of an engineering method for calculating an industrial installation.
Simulation of a low-voltage distribution network when arranging voltage stabilizers
Authors: Aluynov A. , Vyatkina O. , Gracheva E. , Bylanov S.
Published: July 2021

A computer algorithm for optimal voltage regulation using voltage stabilizers is presented. The applied voltage stabilizers are suitable for operation with radial distribution networks, taking into account various load models. The proposed algorithm makes the initial selection, installation, and adjustment of voltage stabilizers, which provide smooth voltage regulation throughout the network, using the existing algorithms, which are appropriately modified and optimized. The algorithm is fast, efficient, and reliable, which is confirmed by its practical application in distribution networks.
Development of an automated control system for 6/0.4 kV transformer substation with automatic transfer switch using standard IEC 61131-3
Authors: Ivanova V. , Rozhentcova N. , Gracheva E. , Udaratin A.
Published: July 2021

This work is devoted to the development of an automated transfer switch (ATS) for the 6/0.4 kV substation. The work is relevant due to the introduction of automation and the replacement of electromechanical equipment with microprocessor devices in the power systems. At the lower (field) level, automation is driven by the use of programmable logic controllers (PLCs) and various smart sensors. The possibility of using modular PLC in automation systems is considered. Developed are an algorithm and a program for the implementation of automated regulation of the application of automatic transfer switches at a substation using the recommendations of the IEC 61131.3 “Programming languages of programmable logic controllers” standard.
Experimental Investigation of Using an Electromagnetic Gearbox to Ensure Dynamic Stability
Authors: Zhidkov Alexey , Achitaev Andrey , Gracheva Elena
Published: July 2021

Small generation is constantly increasing both in Russia and around the world. At the same time, more and more urgent problems arise related to the loss of dynamic stability of rotating machines with low inertia of their rotors. The paper proposes one of the variants for solving this problem by fundamental transformation of the principles of small generation, taking into account the development of a flexible coupling between a turbine and a generator by using an electromagnetic gearbox instead of a connecting coupling. Investigations are carried out on a physical prototype of an electromagnetic gearbox with observation of real parameters.
Chiral phosphoric acid and its applications of asymmetric catalytic hydrogenation
Authors: Zhuoxin Sun
Published: July 2021

As an excellent representative of organic small molecular catalysts, chiral phosphoric acid played an important role in asymmetric catalytic hydrogenation. According to the skeleton of chiral phosphoric acid, the development and applications of chiral phosphoric acid were summarized. The applications of chiral phosphoric acid in asymmetric catalytic hydrogenation were introduced according to three kinds of hydrogen source systems used in chiral phosphoric acid catalytic reaction. It was found that chiral phosphoric acid has high activity and excellent selectivity. Chiral products with excellent yields and enantioselectivities were obtained in most reactions.
Research on textile materials for X-ray shielding
Authors: Liang Dong , Shen Fu , Bao Zizhen , Liu Yuchen , Li Honghui
Published: July 2021

X-ray radioactive rays are widely used with the continuous development of radioactive medicine and nuclear technology applications, as well as lead shielding material pollutions new no lead shielding material was needed. In this paper, the main properties of metal tungsten and bismuth as X-ray shielding materials were studied for the protection people avoid the 150 kV X-rays by the Monte Carlo method is used to study. According to simulation with 2 kg/m2, results show that performance of single metal material tungsten iron is superior to that of bismuth material. Tungsten-bismuth better than bismuth-tungsten with the case of equal-quality double-layer metal. The protection performance is better when the metal-mixed tungsten-bismuth ratio is 0.5: 0.5 or the tungsten ratio is large. The research provides effective support for the development of textile radiation protection materials.
Mechanism of Oxygen Reduction Reaction for Sulfur-Doped Graphene Catalyst: First-principles research
Authors: Li Guifa , Wang Hui
Published: July 2021

The mechanism of oxygen reduction reaction for surfur-doped graphene catalyst was investigated by first-principles calculation. Several parameters, such geometry structure, reaction energy and electronic structure were used to analyze the reaction process. The results show that the OOH molecule absorbed on S-graphene with pyridine structure exhibits chemical adsorption. But the OOH molecule on S-graphene with pyrrole structure performs physical adsorption. The adsorbed energies of OOH molecule on S-graphene prove such phenomenon. The electronic structure shows that the excellent ORR of OOH molecule on S-graphene with pyridine structure comes from their adjacent energy level of valence electron no matter in highest occupied molecular orbital (HOMO) or lowest unoccupied molecular orbital (LUMO).
Condensation polymers: synthesis, properties, and applications
Authors: Cheng Ziyi , Liu Yang , Li Zehao , Song Yixuan
Published: July 2021

With the widening of the application fields of polycondensation polymers, many types of modifiers have been used to modify the molecular structure of polycondensation polymers. In recent years, more and more researchers have focused on the study of the molecular structure modification of polycondensation polymers and gradually ignored the research on the synthesis methods and properties of polycondensation polymers. This review covers the synthesis strategies of four common polycondensation polymers in the market, including polyamide (PA), polycarbonate (PC), polyester (PET), and phenolic resin. Two general synthesis routes of PET starting from dimethyl terephthalate and terephthalic acid were suggested; the synthesis strategies of PA-66 and PA-6 were discussed; the synthesis methods of aromatic PC from bisphenol A polycarbonate by phosgene or transesterification were summarized; the general synthesis methods of thermoplastic phenolic resin and thermosetting phenolic resin were discussed. In addition, some new synthesis methods and modification methods of these polycondensation polymers were reviewed. Besides, the properties, application, and market value of these polycondensation polymers were summarized. It is hoped that it will be helpful for the new synthesis of polycondensation polymers.
Purification of tubulin and microtubules from mouse brain
Authors: Li Xiangxiao
Published: July 2021

Purified tubulin or microtubules are widely used for in vitro assays related to their function, such as activities of their modifying enzymes and motor protein activity. This paper gave a review for purification tubulin and microtubules (MTs) using two different methods. One method of purification MTs depended on polymerization and depolymerization. MTs were polymerized at 37 °C with taxol in the presence. Another method is to purify tubulin by affinity column chromatography. Stu2p, a kind of MAPs, is able to bind with C-terminal of tubulin. Recombinant Stu2p was purified from expressing bacteria. Then Stu2p was coupled with NHS-activated resins, which were used to purify tubulin from mouse brain. Tubulins purified in this way can also be polymerized at 37 °C.
Application of random walk to model temperature in 60 African cities for the 20th century
Authors: Yan Shaomin , Wu Guang
Published: July 2021

The 20th century is marked with climate change led by global warming. So far, many models have been applied to analyze the temperature change. However, a simple but interesting model, a random walk is hardly used in his regard. In this study, we use the random walk to model the temperature in the format of random walk that is the conversion of recorded temperature and the real recorded temperature in 60 African cities including 53 capitals for the 20th century. The results show that the random walk can satisfyingly model either temperature in the format of random walk or real recorded temperature although the fitted results from other climate models are unavailable for comparison in these 60 cities. As nothing else besides random numbers is involved in this modelling, the results seem somewhat counter-intuitively.
A Retinex-based Enhancement method for Ocean Remote Sensing Image
Authors: Li Tongyu , Chen Jie , Cheng Pu , Yu Lu
Published: July 2021

In order to effectively monitor important sea areas, one of the key issues is the detection of small dynamic targets such as ships. Besides monitoring the hull itself, the monitoring of small targets can also be achieved by detecting ship wakes, which means the sea image with clear texture feature is required. This paper firstly reviews the multiscale retinex (MSR) method, commonly used to enhance the image contrast. Then, it proposes a novel contrast enhancement algorithm base on the subband-decomposed multiscale retinex (SDMSR) method. Experimental results show that our proposed method can make a remarkable enhancement effect for ocean remote sensing images with clouds and whitecap, etc.
PS-InSAR based surface subsidence analysis in Changchun metropolitan area
Authors: Wang He , Mao Jiuchang , Zhao Shijun , Ning Xinguo , Wu Qiong
Published: July 2021

The monitoring of urban land surface subsidence is the main task of urban disaster prevention and mitigation. In this paper, the land surface subsidence process in Changchun metropolitan area is calculated based on PS-InSAR technology by using the SLC data of Sentinel-1B with 50 scenes within the metropolitan area of Changchun from 2016 to 2020. The results show that the metropolitan surface of Changchun is basically in a stable state, the main settlement is located in the southeast of the metropolitan around the Century Square, the maximum settlement rate is 20.45mm/a, the average settlement rate is 2.98mm/a, the correlation coefficient between the settlement results calculated by PS-InSAR and the second-class leveling verification results reaches 0.67, which indicates that the regional settlement results calculated by PS-InSAR have high reliability. The subsidence area is dominated by the geological structure of the Mesozoic Cretaceous Yaojia Formation, with many intercalations of fine silty sand rocks and locally containing medium-coarse gravel sandstone. The overall structural stability is poor, which may be the main reason for subsidence in this area.
Hydrochemical Characteristics and Evolution Laws of Shallow Groundwater in Shuangliao City
Authors: Xuguang Li , YanDai Zhao , Haiyang He
Published: July 2021

Shuangliao City is an important part of the Xiliaohe Plain, and one of the most important bases of grain production in the north of China. Therefore, it is important to ascertain the hydrochemical characteristics of groundwater and their causes and evolution laws in the Xiliaohe Plain to provide guidance to agriculture development and ecological improvement. After collection of detailed data and identification of the groundwater flow field, we studied the causes and evolution of the identified hydrochemical types by zone with mathematical statistics, correlation analysis, ion proportional coefficient and other methods. The results show that the concentrations of HCO3-, Cl-, and Na+ are relatively high, and these of Ca2+, Mg2+, SO42-, and NO3- are relatively low. The concentration of TDS increases gradually along the flow direction of groundwater, and TDS is positively correlated to the variation in concentration of Cl-, Na+, Mg2+, and SO42-. Along the flow direction of groundwater, the hydrochemistry of shallow groundwater show the evolution law from HCO3-Ca·Mg to HCO3·Cl-Na·Ca and HCO3·Cl-Na·Mg, and then to Cl·HCO3-Na·Mg. The hydrochemical types are formed mainly due to the mineral dissolution and deposition, and reaction of cation exchange and adsorption in the aquifer, and the hydrogeochemical processes include leaching, evaporation and concentration, and mixing.
A Statistical Study of lyrics of “Huar” from Northwest China
Authors: Xu Yan , Tang Qianqian , Yuan Ying
Published: July 2021

As an intangible cultural heritage, “Huar” from Northwest China is a folk song created and shared by many ethnic groups in Gansu, Qinghai and Ningxia provinces. It is a precious card of Chinese national culture. However, current research on “Huar” is mainly based on qualitative methods. This paper uses statistical methods to study the lyrics of “Huar". First, the word frequency of the lyrics of “Huar” is analysed statistically. Then, the lyrics of Hezhou Huar and Taomin Huar are compared and analysed from the perspective of quantitative linguistics ("Huar” mainly includes Hezhou Huar and Taomin Huar). By comparing three quantitative indicators, it is concluded that the lexical richness of Taomin Huar is higher than that of Hezhou Huar. Based on the frequency distribution of parts of speech, the similarities and differences of the use of parts of speech between Hezhou Huar and Taomin Huar are found. This paper uses statistical methods to analyse “Huar", which has certain research value and social value.
Side Scan Sonar Shipwreck Image Recognition Algorithm based on Transfer Learning and Deep Learning
Authors: Zhang Boyu , Wang Xiao , Li Shudong , Yang Jinghua
Published: July 2021

Current underwater shipwreck side scan sonar samples are few and difficult to label. With small sample sizes, their image recognition accuracy with a convolutional neural network model is low. In this study, we proposed an image recognition method for shipwreck side scan sonar that combines transfer learning with deep learning. In the non-transfer learning, shipwreck sonar sample data were used to train the network, and the results were saved as the control group. The weakly correlated data were applied to train the network, then the network parameters were transferred to the new network, and then the shipwreck sonar data was used for training. These steps were repeated using strongly correlated data. Experiments were carried out on Lenet-5, AlexNet, GoogLeNet, ResNet and VGG networks. Without transfer learning, the highest accuracy was obtained on the ResNet network (86.27%). Using weakly correlated data for transfer training, the highest accuracy was on the VGG network (92.16%). Using strongly correlated data for transfer training, the highest accuracy was also on the VGG network (98.04%). In all network architectures, transfer learning improved the correct recognition rate of convolutional neural network models. Experiments show that transfer learning combined with deep learning improves the accuracy and generalization of the convolutional neural network in the case of small sample sizes.
The Application of Big Data Technology in the Practical Research Work of Ideological and Political Courses
Authors: Bai Yuhong
Published: July 2021

This article analyzes the application advantages, application core and technical nature of big data technology. The author studies the specific application of big data technology in the allocation of topics, pre-class research, data collection and processing, data statistical analysis, and data rational application. This article studies how to do well in survey method training, how to improve the data management system, how to strengthen the curriculum construction of colleges and universities, and how to actively learn from successful cases. The author’s purpose is to enhance the application value of big data technology and improve the reliability of the practical survey results of ideological and political courses.
Research on the Professional anxiety of News Editors in the era of Intelligent Media
Authors: Jin Yuanke , Liu Yan
Published: July 2021

Intelligence-intensive media are in the ascendant driven by algorithms and data. New technology not only leads news editors into the intelligent era, but also has an impact on them. Artificial intelligence carves up the work of news editors, while virtual reality forces the news editing industry to change, and the new concussion of business format causes the professional anxiety of news editors. Based on the background of media intelligence, this paper analyzed the psychological mechanism of professional anxiety caused by intelligent media to news editors from three aspects: cognition, emotion and motivation, it also put forward the scientific cognitive model, the psychological model of the combination of defense and confrontation, and the efficiency improvement model of multi-agent participation.
Study on comprehensive utilization technology of low concentration coal bed methane
Authors: Xiao Lu
Published: July 2021

Aiming at the problems of low utilization rate and serious environmental pollution caused by low concentration coal bed methane emission in a coal mine, the utilization technology of low concentration coal bed methane was studied by means of field investigation and theoretical calculation, and the technical solution of comprehensive utilization of low concentration coal bed methane combining regenerative oxidation and cryogenic liquefaction was obtained, which realized the “coal and gas are co-mined and shared” and constructed the virtuous cycle development of “use to promote pumping, pumping to promote safety”. The research shows that: the low concentration coal bed methane with concentration of about 5% is converted into high temperature flue gas by regenerative oxidation, and the heat energy is extracted to realize the heating in the mining area; the coal bed methane with concentration of more than 35% is purified and liquefied into LNG product by cryogenic liquefaction, so as to realize long-distance transportation. The technology improves the utilization rate of coal bed methane in the mining area and eliminates the burning of coal for heating. The annual utilization of pure gas is 53.38 million m3, generating economic benefits of 211 million yuan and reducing CO2 equivalent by 767,000 t. The safety, economic and environmental benefits are remarkable. This technology has practical significance to improve the utilization rate of gas and promote the realization of the goal of zero gas emission.
A study on the characteristics of diatoms and ecological environment pollution in the main water of Tianjin, China
Authors: Enh Sugur , Fang Jing , Ma Pengyi , Liu Bo , Zhang Heng , Lan Dexuan , Yang Ziyao , Dolka Ping Cuo , Wang Zhifei
Published: July 2021

Twenty lake bottom surface layers mud and water samples in the Qilihai Wetland and the Beidagang Reservoir in Tianjin were taken to do diatoms analysis. More than 6000 diatoms were identified and divided into 117 species and 28 genera. Based on the calculation of DAIpo(Diatom Assemblage to organic water pollution), the water pollution level of the Beidagang Reservoir can be divided into: Xenosaprobic, β -oligosaprobic, α -oligosaprobic, β -mesosaprobic, from clear to slightly cloudy water. The water pollution level of Qilihai wetland can be divided into: extremely oligarchy dirt belt, β oligarchy dirt belt, α oligarchy dirt belt, β Medium dirt belt, that is, the water quality is clear to slightly turbid. The water quality of the Beidagang Reservoir is clearer than that of the Qilihai Wetland. The physical and chemical indexes such as EC, pH, TN, TP and CODMn were determined for the water samples, and the correlation between DAIpo and these measured values was analyzed. The results showed that the degree of water pollution detected was consistent with the conclusion obtained by diatom analysis. The results show that the water quality of the Beidagang Reservoir and the Qilihai Wetland was mildly polluted in the spring and summer of 2019, but the eutrophication is more serious.
Fluid inclusions, H-O-S isotopic characteristics and genesis of the Chambishi copper deposit, Zambia
Authors: Qiaofan Hu , Zuohai Feng , Jiangping Mo , Ke Fang
Published: July 2021

In this paper, fluid inclusions and H-O-S isotope geochemistry of the Chambishi copper deposit in Zambia are studied. According to the fluid inclusion in quartz and H-O-S isotope characteristics, it is concluded that ore-forming hydrothermal fluid is derived from mantle source and crust source magma mingling, the cause of copper precipitation, sedimentary type sulfur layered mineralization are mainly from diagenetic sulfides and seawater sulfate. Sulfate is mainly reduced by thermochemical method. The hydrothermal vein mineralization of Chambishi copper deposit is closely related to the magmatic activity in the middle Neoproterozoic, and the sedimentary stratified mineralization is mainly related to the large-scale orogeny and regional metamorphism in the late Neoproterozoic.
Big data method and its application in innovation education research
Authors: Song Yankui , Jie Chuijiao , Xu Zhijin
Published: July 2021

Big data technology is a new stage of information development. In recent years, it has been widely used in many fields, especially in social science research. This paper analyzes the development status and significance of the combination of big data technology and social science research, on the basis of summarizing and combing the concept of big data and its important role. Taking the application of big data method in the research of innovation education as an example, this paper makes a series of visualization analysis with Citespace software on the related literature with the theme of “big data and innovation education” collected by CNKI, such as annual analysis, literature source analysis, co-occurrence analysis of authors, organization analysis, keyword clustering analysis and keyword timing analysis. This paper also draws the corresponding knowledge mapping, clarifies its research status, hot spots and development trend, and provides scientific basis for the research of innovation education. Thus the paper believes that the research on big data and innovation education needs to strengthen interdisciplinary communication and cooperation, refine and deepen the research theme and content.