bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetic trap formation during the breakdown of high pressure gases in strong magnetic fields
Authors: Omarov O A , Omarova N O , Omarova P Kh , Kurbanismailov V S 
Published: November 2019

Abstract
Formation of hot plasma in strong magnetic fields during the breakdown of high-pressure gases in short gaps was studied experimentally. The breakdown occurs as a result of interaction of monoenergetic electron beam with dense plasma (n ∼ 6·1022 m−3). As a result of the spark channel formation and its explosive expansion inside the gap, the magnetic field in the anode and cathode regions becomes more intense, while between the electrodes it becomes weaker due to the expansion of the channel plasma. Thus, the axially symmetrical magnetic-mirror-type system is formed, which is similar to the magnetic trap. Formation of this system leads to the reduction of energy losses accompanied by a simultaneous increase in the plasma thermal energy, that is, to a considerable increase in its conductivity and temperature.
Propagation of microwave surface-wave-sustained discharge in air
Authors: Zhukov V I , Karfidov D M , Sergeichev K F 
Published: November 2019

Abstract
The propagation dynamics of the gas microwave discharge front in a quartz tube filled with air is studied experimentally. The discharge is initiated and sustained by the dipolar mode (m = 1) of the propagating surface electromagnetic wave (SEW). The discharge front propagation regime was experimentally discovered, which is characterized by the arrest of propagation of the discharge front, the plasma decay and the subsequent resumption of the translational motion, but at a lower propagation velocity. The distributions of the SEW electric field and the integrated discharge luminosity along the plasma column are measured. The mean plasma density in the tube was estimated using data on the measured SEW wavelengths and the dispersion relation.
Parameters of plasma bunches generated in a long mirror trap under conditions of gyromagnetic autoresonance
Authors: Andreev V V , Novitsky A A , Umnov A M 
Published: November 2019

Abstract
Temporal evolution of the spectrum and intensity of bremsstrahlung generated by the plasma bunches formed in a symmetric long mirror trap under conditions of gyromagnetic autoresonance was studied experimentally in detail. Bremsstrahlung was detected by two identical detectors installed in the axial and radial directions with respect to the stationary magnetic field. The results show that the radiation is spatially inhomogeneous. The parameters of the spectra measured in the radial direction strongly depend on the amplitude of the pulsed magnetic field, while the spectra measured in the longitudinal direction are determined mainly by the ECR conditions in the phase of filling the trap with the primary plasma. The integrated intensities, obtained with allowance for the refined form factors of the generated bunches recorded using the high-speed photochronography, made it possible to determine the number of primary plasma particles trapped in the autoresonance mode.
Plasma technology for surface processing of the ruthenium pacemaker electrodes
Authors: Martynenko Yu V , Budaev V P 
Published: November 2019

Abstract
For pacemaker electrodes, the surface structure elements should be nanometer-sized in order to reduce the capacitive electrical resistance coupling of the electrode with the myocardium tissue. It is proposed to test several approaches. One of them is the creation of the “fuzz” nanostructure on the titanium surface accompanied by the subsequent ruthenium deposition onto this structure. Another one is the formation of the “fuzz” nanostructure on the layer of pre-deposited ruthenium. Such approaches contribute to developing new technology for manufacturing the electric cardiac pacemakers with improved characteristics.
Features of using plasma flows to compensate the aerodynamic drag of mini-satellites moving in the ionosphere
Authors: Nosachev L V , Skvortsov V V , Urusov A Yu , Uspenskii A A , Flaxman J Sh 
Published: November 2019

Abstract
The possibilities of using plasma flows formed in electric jet engines (EJE) are considered. One of the variants of the EJE construction are ion sources with multi-cell ion-optical systems used to compensate the aerodynamic drag of mini-satellites in the Earth’s ionosphere with the aim of ensuring long-term operation of the latter at low flight altitudes (∼180–220 km). The analysis of methods of simulation of the operation of such engines together with air intakes under ground conditions is given. The possibility of using plasma-ion sources producing molecular beams of nitrogen or air ions with low (orbital) flight speeds as a source of the free flow in the simulations is considered. A source with volumetric ionization of the working gas and electron oscillation in the magnetic field in a chamber between the walls held at the cathode potential and a large multi-cell aperture of the ion–optical system is used to create the flow. The results of the studies of the operation of a plasma–ion engine (PIE) together with air intake obtained by the gas-dynamic simulation method are presented. The possibility of a high performance of the engine under non-standard conditions is shown. It is found that a stable operation of the PIE can be realized at pressures of 6⋅10−5–10−4 Torr in its chamber, which is important for matching the engine with the air intake.
On the issue of quantum theory of the Fresnel reflection
Authors: Veklenko B A 
Published: November 2019

Abstract
A new method for solution of the quantum electrodynamics equations is proposed. This method makes it possible to avoid the procedure of breaking the quantum correlators and bridges the gap between the theories of Maxwell gases and the theories of superconductivity and superfluidity. As an example, the quantum theory of the Fresnel reflection is considered. It is shown that, even outside the scattering layer, there are the photon states correlated with the scattering layer by means of the quantum correlations. In particular, such photons form two reflected beams previously unknown.
Generation of fast electrons in pulsed discharge plasma in helium
Authors: Shibkov V. M 
Published: November 2019

Abstract
The results of experimental studies of the distribution function of fast electrons under conditions of non-equilibrium plasma of a pulsed discharge in helium are presented. It was established by various methods that at the initial stage of the discharge, when the reduced electric field exceeds the critical value, a beam of fast electrons is generated. The beam energy depends on the applied voltage to the discharge gap, and helium pressure.
Hypersonic plasma flows created by a pulse capillary discharge
Authors: Pashchina A S 
Published: November 2019

Abstract
The possibility of producing by a pulsed capillary discharge the quasi-stationary high-speed plasma flows in a wide range of Mach numbers (M=3-20), electron number densities (ne
∼1011-1015 cm-3) and temperatures (Te
∼3-10 eV), rotational and vibrational temperatures (Tr
=3800-6000 K and Tv
=9000-15000 K), which can be used for setting up plasma aerodynamic experiments on small laboratory facilities, is shown. The most suitable for this purpose is a mode close to supersonic outflow into a vacuum, the transition to which occurs when the total pressure ratio exceeds N = p
0/p
∞ >5·103. This mode permits to obtain wide-aperture flows (D >10 cm) with spatially extended weakly inhomogeneous segments sufficient to accommodate tested bodies of a centimeter scale.
Pulsed plasma jet interaction with a metal targets
Authors: Pashchina A S , Klimov A I , Belov N K , Tolkunov B N , Kh Timirbulatov V 
Published: November 2019

Abstract
The results of experimental studies of the interaction of plasma jets, created by a pulsed capillary discharge with an evaporating wall, with metal targets are presented. It is shown that the main mechanism of targets destruction is the material melting and the subsequent removal of the melt under the dynamic pressure of the plasma jet. The main sources of energy transmitted to the target are: the high-speed flow of high-enthalpy plasma created inside the capillary, and the fluxes of charged particles accelerated in the near-electrode layers. The energy transport provided by charged particles does not exceed ∼0.1–0.2 of the total energy input onto the target. The enthalpy transport is capable to provide heat flux densities of ∼5-6 kW/mm2, an order of magnitude exceeding the values achievable in welding arcs.
Determination of the fraction of electrical energy released in the oncoming supersonic airflow using long spark discharge
Authors: Saveliev A S 
Published: November 2019

Abstract
In present work an indirect measurement of the fraction of stored electrical energy, that by initiating long spark discharge of submicrosecond duration transforms into air heating, that moves near the surface of an aerodynamic model at supersonic speed with Mach number M = 2, was carried out. Using the Particle Image Velocimetry method the flow velocity behind the front of an induced quasi-cylindrical shock wave that occurs when heat is released with long spark discharge was measured. This process was modeled in a two-dimensional formulation using a numerical simulation with OpenFOAM package. By comparing the data obtained in the experiment and in the numerical simulation the value of the fraction of stored electrical energy, which goes to the local heating of air, was determined.
Impact of homogeneous and ionization unstable glow discharge plasma on a shock wave in air
Authors: Erofeev A.V. , Lapushkina T.A. , Azarova O.A. 
Published: November 2019

Abstract
The work is aimed at exploring the possibility of control of strong shock waves up to their completely destruction. The impact on shock waves by creating a region of gas-discharge plasma in propagation media is proposed. A diffuse or ionization unstable discharge with the ionization strata of different scale on the path of a shock wave propagation is organized. As a result, the shock wave propagates over the region of homogeneous highly non-equilibrium plasma or over the medium of layered structure with higher degree of ionization and electron temperature in the layers. Numerical simulation of the propagation of a shock wave over the region of energy impact was carried out on the basis of the systems of Euler and Navier-Stokes equations with the flow parameters obtained in the experiment. The homogeneous plasma region was simulated by a rarefied gas region with increased temperature and constant pressure. The area formed by the ionization unstable discharge was simulated by a thermally stratified gas area. The strong influence of the ionization of the propagation medium on the transformation of the shock wave with the formation of a new shock wave configuration is shown. Stratification of the medium leads to a distortion of this configuration up to complete destruction of it.
Nanosecond volume discharge in the flow with diffracting shock wave in the rectangular channel
Authors: Znamenskaya I , Tatarenkova D , Kuli-zade T 
Published: November 2019

Abstract
New effects of plasma redistribution shock wave (M = 2.8–3.4) diffraction on an obstacle at flow ionization with pulse volume discharge are presented. The obstacle has size 48.0 × 6.2x1.9 mm3 and consist of forward facing and backward facing steps on the wall. Localization of the nanosecond combined discharge plasma (with pre-ionization in the volume) in non-stationary gas flow was visualized with plasma glow imaging. It is shown that the discharge images visualize flow evolution structure, mainly - zones of reduced density. Image are compared with 2D CFD simulation.
Numerical simulations on MHD break in hypersonic flow
Authors: Bityurin V.A. , Bocharov A.N. , Popov N.A. 
Published: November 2019

Abstract
One of possible effect of electromagnetic field on the high-speed ionized airflow is considered. Namely, deceleration of the flying body due to interaction of the electric current induced around the body with the magnetic field generated by on-board magnetic system is studied. The principal scheme of magnetohydrodynamic interaction over the flat plate is presented. The goal of the study is to demonstrate the deceleration effect in terms of standard aerodynamic drag. Two test cases are considered: small-scale (lab-scale) interaction zone size and large-scale (space-scale) one.
The primary result of the study is a feasibility to increase the total drag of the body in more than order of magnitude relative to the original one. The effect can be achieved by means of practically reasonable magnetic field amplitudes. Common for both cases is that the total drag grows as the magnetic field increases. The difference between two cases is that significantly smaller magnetic fields are required in space-scale case to increase aerodynamic drag than in the lab-scale case. In any case, the drag control could be used as a potential for high-speed flow control.
Early transformation of the Chinese power sector to avoid additional coal lock-in
Authors: Wang Huan , Chen Wenying , Bertram Christoph , Malik Aman , Kriegler Elmar , Luderer Gunnar , Després Jacques , Jiang Kejun , Krey Volker 
Published: November 2019

Abstract
Emission reduction from the coal-dominated power sector is vital for achieving China’s carbon mitigation targets. Although the coal expansion has been slowed down due to the cancellation of and delay in new construction, coal-based power was responsible for over one third of China’s energy-related CO2 emissions by 2018. Moreover, with a technical lifetime of over 30 years, current investment in coal-based power could hinder CO2 mitigation until 2050. Therefore, it is important to examine whether the current coal-based power planning aligns with the long-term climate targets. This paper introduces China’s Nationally Determined Contribution (NDC) goals and an ambitious carbon budget along with global pathways well-below 2 degrees that are divided into five integrated assessment models, which are two national and three global models. We compare the models’ results with bottom-up data on current capacity additions and expansion plans to examine if the NDC targets are in line with 2-degree pathways. The key findings are: 1. NDC goals alone are unlikely to lead to significant reductions in coal-based power generation. On the contrary, more plants may be built before 2030; 2. this would require an average of 187–261 TWh of annual coal-based power capacity reduction between 2030 and 2050 to achieve a 2 °C compatible trajectory, which would lead to the stranding of large-scale coal-based power plants; 3. if the reduction in coal power can be brought forward to 2020, the average annual coal-based power reduction required would be 104–155 TWh from 2020 to 2050 and the emissions could peak earlier; 4. early regulations in coal-based power would require accelerated promotion of alternatives between 2020 and 2030, with nuclear, wind and solar power expected to be the most promising alternatives. By presenting the stranding risk and viability of alternatives, we suggest that both the government and enterprises should remain cautious about making new investment in coal-based power sector.
Evidence for accelerated weathering and sulfate export in high alpine environments
Authors: Crawford John T , Hinckley Eve-Lyn S , Litaor M Iggy , Brahney Janice , Neff Jason C 
Published: November 2019

Abstract
High elevation alpine ecosystems—the ‘water towers of the world’—provide water for human populations around the globe. Active geomorphic features such as glaciers and permafrost leave alpine ecosystems susceptible to changes in climate which could also lead to changing biogeochemistry and water quality. Here, we synthesize recent changes in high-elevation stream chemistry from multiple sites that demonstrate a consistent and widespread pattern of increasing sulfate and base cation concentrations or fluxes. This trend has occurred over the past 30 years and is consistent across multiple sites in the Rocky Mountains of the United States, western Canada, the European Alps, the Icelandic Shield, and the Himalayas in Asia. To better understand these recent changes and to examine the potential causes of increased sulfur and base cation concentrations in surface waters, we present a synthesis of global records as well as a high resolution 33 year record of atmospheric deposition and river export data from a long-term ecological research site in Colorado, USA. We evaluate which factors may be driving global shifts in stream chemistry including atmospheric deposition trends and broad climatic patterns. Our analysis suggests that recent changes in climate may be stimulating changes to hydrology and/or geomorphic processes, which in turn lead to accelerated weathering of bedrock. This cascade of effects has broad implications for the chemistry and quality of important surface water resources.
Research on discrimination algorithm of electric energy substitution user based on logistic regression model
Authors: Chen Jihuan , Lu Yudong , Liu Qiang , Li Lei , Miao Bo 
Published: November 2019

Abstract
The current power grid is found with low visiting efficiency, information integration difficulty and other problems in case of promotion of electric energy substitution. The big data technology is featured by high efficiency, high speed and convenience in terms of information processing, so it can realize the precise localization and differentiated marketing objectives of each enterprise. This paper, based on the analysis of energy consumption status of current power grid user and by means of “industry-field-user” architectural analysis, classifies user as per industry and equipment characteristics and combines with existing data of current power grid to exploit the energy consumption and electricity use characteristics of electric energy substitution user and build discrimination model of electric energy substitution user so as to improve the working efficiency and economic benefit of power grid business.
Research and Application of Prussian Blue in Modern Science
Authors: Chiang Yen-Hsin 
Published: November 2019

Abstract
Recently, the attention to Prussian Blue has been aroused in the next generation applications in many areas, due to its specific advantages. However, the development of Prussian blue remains significant challenges. For example, nowadays, it can effectively improve the electrochemical performance of ions batteries. Herein, we summarize the recent advances and applications materials on the progress of the study and application of Prussian Blue in several area, including storage, electrochemistry, photochemical, medical. Special attentions were given on the following items: Prussian Blue Sensor, Ionic batteries and Hydrogen storage. The superior chemical nature of Prussian Blue makes Prussian Blue important in many areas.
Systematic Study on Hydraulic Cylinder of Farmland DTH Drilling Machine
Authors: Chen Yiwei , Ma Yongshuang , Zhang Xiaolei 
Published: November 2019

Abstract
Connecting and unloading rod is one of the important processes in the drilling process of DTH drilling rig. The unloading device not only affects the operator’s labor intensity and safety, but also affects the efficiency of drilling rig and the service life of drilling rod. Therefore, the research and design of unloading rod structure is of great significance to improve the efficiency of DTH drilling rig. Firstly, the selection of unloading rod hydraulic cylinder is analyzed, including the calculation of main parameters, cylinder design, piston design and calculation, cushioning and exhaust device. Secondly, the clamp rod hydraulic cylinder is designed and calculated, including the structure of the clamp rod cylinder, the clamp force calculation of the clamp rod cylinder and the wall thickness calculation of the clamp rod cylinder. Finally, we set the structure and parameters correctly to increase the efficiency of the hydraulic cylinder of the down-the-hole drill in the field operation.
Research on Parallel Control Strategy of Virtual Synchronous Generators with same capacity
Authors: Wang Yanan , Yan Pengbo 
Published: November 2019

Abstract
In view of the public AC bus’s frequency stability problem of traditional droop control parallel inverters when load fluctuate frequently, virtual synchronous generator, VSG, is presented in this paper to instead traditional droop control in inverters parallel. The frequency stability of the public AC bus is improved and the output power is divided equally. In view of the VSG parallel preliminary synchronization, a preliminary synchronization method is designed based on phase-locked loop to realize the same phase between the VSG output voltage and public AC bus before paralleling. The simulation and experimental results verify the effectiveness of the proposed control strategy.
Application of Fuzzy Mathematics Evaluation Method in Prediction of Comprehensive Efficiency of Low Efficiency Oil Wells
Authors: Li Xiaofeng 
Published: November 2019

Abstract
In the process of oilfield development, due to long-term continuous mining and changes in geological conditions, oil-inefficient wells will be gradually produced. This phenomenon is unavoidable. How to optimize the low-efficiency oil wells with comprehensive mining potential according to the actual development situation, so as to achieve effective treatment of low-efficiency oil wells, this approach is of great significance to ensure and improve the overall economic benefits of the oilfield. In this paper, the fuzzy mathematics method and the statistical weighting theory are used for comprehensive analysis. The weight of the evaluation index is predicted by determining the comprehensive adjustment potential of the low-efficiency oil well, and then the low-efficiency oil well comprehensive adjustment potential prediction evaluation model and method are established, and then the practical application is carried out. The method can provide a basis for judging the comprehensive adjustment measures for the development of low-efficiency oil wells in oil fields.
The propagation research of hydraulically created fractures in coal seams based on discrete element method
Authors: Lu Yanjun , Han Jinxuan , Shelepov V.V , Wang Qiang , Zhu Yongsheng , Guo Junfeng , Zhang Liang , Han Wei 
Published: November 2019

Abstract
Coalbed methane (CBM) is clean unconventional energy that can be exploited with stimulation treatment to realize commercial value, and hydraulic fracturing is the key technology for increasing CBM production. The simulation of hydraulic fractures is an important research content that can guide the engineering practice to achieve the purpose of increasing production. Based on the distribution characteristic of cleats in coal, the research on the propagation of hydraulic fractures is carried out via Discrete element method (DEM). The simulated results show that: hydraulic fractures mainly propagate along the cleats towards the maximum principal stress. The fracture network can be formed due to the intersection of face cleats and butt cleats that can propagate at certain pressure. During the injection process of fracturing fluid, the pressure at injection point decreases with the fracture propagation until the pressure tends to be stable. With the increase of injection rate and fracturing fluid viscosity at the same condition, the maximum aperture of hydraulic fracture increases, while the length of principal hydraulic fracture shortens. Therefore, to achieve the purpose of forming hydraulic fracture network in coal seams with cleats, low viscosity fracturing fluid and low injection rate need be applied to the fracturing technology. As the cleat density increases, the number of branch fractures increases, but the length of principal hydraulic fracture becomes short. Long and narrow hydraulic fractures are easily formed in coal seams with lower cleat density.