bluuebunny/crossref_metadata_2025 huggingface dataset:
Mass contents of natural radioactive elements in the main types of rocks of the Mesozoic sediments of the West-Siberian Plate and their comparative assessment with the contents in the deposits of some sedimentary basins of the former USSR
Authors: Turyshev Viacheslav
Published: July 2020

The average and boundary contents of natural radioactive elements in sandy, aleuritic, argillaceous, mixed and carbonaceous types of sedimentary rocks of the main groups of productive strata of the Jurassic-Cretaceous age of Western Siberia are estimated; a comparison of the obtained values of the contents of radioelements with their contents in sedimentary deposits of some regions of the former USSR is performed.
Math modeling of particle movements in a friction separator
Authors: Potapov Valentin , Afanasyev Anatoliy , Potapov Vladimir , Frolov Sergei , Franyuk Ekaterina
Published: July 2020

A mathematical model of particles movement of separated material in a friction separator is proposed. It includes equations of their movement at each stage of separation (along a rough inclined plane, on a curvilinear part of a springboard, impact of a particle on the surface of a drum, free motion before leaving the separation zone), and differential equations of particle movement in circulating air flow created by a rotating drum; Each of these phases of motion is described by a system of equations obtained on the basis of basic laws of mechanics. An analysis of a particle motion along aslope plane was carried out on the basis of the law on energy changes. Depending on the ratios of the recovery factor and instantaneous friction, being random variables and also the coordinates of a point impact the particle is possible to move along different trajectories with different initial conditions. The mathematical model of the process of separation of loose multicomponent materials on a friction drum-shelf separator makes it possible to investigate comprehensively the process of separation of particles on friction and elastic properties and to optimize the operating modes of the apparatus at relatively low costs without using macaques and prototypes and investigate them experimentally. On the basis of analysis of the proposed theories of particles motion, the main ways are formulated of further improvement of methodology for designing and creating friction devices.
Calculation of productivity of multi-section trawls for extraction of ferromanganese nodules
Authors: Rakhutin Maxim , Kashirsky Alexey , Lagunova Yuliya
Published: July 2020

A mathematical model of the operational productivity of trawls for the extraction of ferromanganese nodules from the bottom of the World Ocean is proposed. On the example of the previously proposed cassette trawl, the analysis of the influence of the main factors on the value of operational productivity is carried out.
Determination of the working area of a hydraulic excavator
Authors: Shestakov Victor , Bezkorovainyy Pavel , Franz Tatyana
Published: July 2020

The relevance of the work is due to the need of the design departments involved in the design of hydraulic excavators in techniques that reduce the mass of excavators while providing the required technological capabilities. Existing methods are aimed at determining the size of working equipment on the condition of providing a given working area. The methods are based on an algorithm for calculating the boundaries of the working area for the input dimensions of the boom, stick and bucket, if the obtained boundaries do not correspond to the specified ones, then the dimen-sions of the equipment are adjusted and the calculations are repeated. The boundaries of the working zone determined by these algorithms do not take into account the power capabilities - the bucket can be at a given point, but the realized forces on the teeth do not ensure separation of the rock. The article discusses the methodology in which possible digging efforts are calculated at all points where the bucket can be located.

Results. For a hydraulic excavator with working equipment “direct shov-el”, a mathematical model for calculating digging forces, an algorithm and a program in algorithmic language have been developed to determine possible forces in the elements of the working equipment.
Study of the efficiency of conveyors of mining transport systems of mining complexes
Authors: Bobojanov Maxsud. Kalandarovich , Ziyodulla Oripovich Eshmurodov , Ismoilov Muhriddin Tulkin ugli , Arziev Eldor Izam ugli , Togaeva Gulnoza Ziyodullaevna
Published: July 2020

The current stage of development of open-pit mining is characterized by mining operations at great depths. Increasing the depth of quarries leads to an increase in the volume and distance of transportation of overburden and ore. Therefore, the task of building energy-efficient transport systems, improving the efficiency of existing belt conveyors of mining transport systems is one of the most urgent tasks. The article examines the efficiency of belt conveyors in mining transport systems mining complexes . Various electric drive systems that can be used on conveyors are compared. We have studied the relative inclination that affects the efficiency of conveyors, as well as parameters related to energy consumption, such as the speed of the belt or the width of the belt, as well as design methods. Various methods of controlling adjustable and non-adjustable electric drives and drag distribution effects drag distribution depending on the flow, the dependence of the belt tilt speed range on the flow, the dependence of power on the flow and the influence of gravity, the energy consumption of the conveyor system is calculated for different traction forces.
Investigations of electrophysical monitoring in a full-scale experiment to clean soil contaminated with oil
Authors: Prostov Sergey , Shabanov Evgeniy
Published: July 2020

This article presents the main results of the study of electrophysical processes occurring in the zone of electrical processing during the cleaning of soils from oil pollution. The main conclusions are formulated about the processes occurring in the electric processing zone by changing the relative electrical resistance of the soil, which was measured using microprobe sensors. A comparative analysis of the results of a laboratory experiment on the electrochemical cleaning of contaminated soil in a tank is carried out with the results of a full-scale experiment conducted on a plot of a soil mass in real conditions, but artificially contaminated with oil products (gasoline, used oil. Using single measurements of electrical resistivity by microprobe sensors, the spread of the pollutant in the soil was clarified , the relationship between the physical properties of the array and its electrical wire is established conductive properties. Confirmed high efficiency of this type of control in the study of complex processes occurring in the contaminated ground array.
Ecosystems’ economic assessment in the context of different climatic zones
Authors: Yurak Vera , Emelyanova Evgenia , Kostromina Tatyana
Published: July 2020

The failure of the key approach to assessing the value of natural goods, based only on the assessment of providing value, provoked the emergence of the ecosystem services’ theory. In addition to providing services of nature this theory includes supporting, regulating and social or cultural services. This approach provoked further adjustment of the state regulation system in the way of developing the market of ecosystem services, considering the full range of services provided by nature to society, for the organization of a transparent mechanism for the use of natural resources and ecosystem services. However, to date, in the Russian Federation this approach has not received legislation support, but the academic community is actively working on this aspect and even suggests adding the value of ecosystem services in the methodology for assessing the national wealth. The economic assessment of real and potential damages from ecosystems’ degradation using the theory of ecosystem services becomes extremely important for the development of an algorithm for optimal natural resource management at various levels of state regulation. The results of the study are the identified boundaries of economic assessment of the value of ecosystems (soil and forest) in the context of 1) valuation methods and 2) climatic zones in order to identify the most valuable ecosystems for simplifying the processes of natural resource management.
Waste management based on circular economy principles
Authors: Guman Olga , Wegner-Kozlova Ekaterina
Published: July 2020

Waste management has strategic implications in contemporary world. The demand in combination of economic development with environmental safety is urging to focus on capacities of non-linear economy. Waste management should redirect its efforts to reduction, recycling and treatment techniques, which view the wastes as resources. The goal of this paper is to study theoretical and practical issues of waste management based on circular economy principles from perspective of cross-disciplinary eco-economic collaboration.
The special principles of development of the corporate information system for hi-tech products
Authors: Vinogradova Ekaterina Yurievna , Galimova Anna Igorevna , Andreeva Svetlana Leonidovna
Published: July 2020

In article describes the problem of lack of accounting of specifics of production and estimation of cost of hi-tech production at development and deployment of a corporate information system. Creation of Hi-Tech products on the basis of application of unique productions demands special approach to assessment of their cost that results in impossibility of direct transferring of the existing models to practice of their activity. Authors offer the special principles of creation of a corporate information system by production of hi-tech production taking into account its features. Such approach will allow to carry out the most exact forecasting of cost of production at a stage of its planning and also positive influence of use of the offered principles on efficiency of use of financial resources of the enterprises for production of hi-tech production is noted.
Quality analysis of the Earth remote sensing data in the surface runoff modeling for failure prediction at the tailing dumps
Authors: Rybnikov Petr , Smirnov Alexander
Published: July 2020

The tailing dump operation periodically leads to the failures. A number of failures that have occurred is related to the underestimation of the exposure to atmospheric precipitations (heavy rains, heavy snowmelt, etc.) on the tailings dams. The studies performed during the previous 50 years indicate the need to consider the climate change when calculating both the long-term average and storm runoff and substantiating the engineering solutions in the tailing dump design. The digital elevation models (DEMs) can be used as a basis for solving the problems of hydrological and hydrogeological modeling. Due to the diversity of such models, it is necessary to develop a methodology for its preparation, evaluate the necessary degree of the material post-processing, and determine the time frame for research.
Peptide Cyclization at High Concentration
Authors: Raj Monika , Wills Rachel D. , Adebomi Victor T.
Published: July 2020

The emergence of cyclic peptides as pharmaceuticals has led to an eruption of new methodologies for macrocyclization. However, the cyclization of peptides at high concentrations presents a challenge due to the production of side products like dimers and oligomers. This factor is more pronounced with the cyclization of peptides composed of fewer than seven amino acids, thus has created a need for a new synthetic strategy. Herein, we will elucidate a new chemoselective method termed ‘CyClick’ that works in an exclusively intramolecular fashion preventing the formation of commonly occurring side products such as dimers and oligomers, even at relatively high concentration.

1 Introduction

2 Known Methodologies

3 Novel CyClick Chemistry

4 Conclusion and Outlook
Quantitative X-ray photoelectron spectroscopy explained for specialists and non-experts
Authors: Mandel Savannah
Published: July 2020

Researcher breaks down X-ray photoelectron spectroscopy for non-experts to increase accuracy and efficiency of use.
Fabrication and sensing characterization of an S-tapered fiber probe
Authors: Wang Guanjun , Li Zhuang , Wang Jun , Shen Jian , Zhang Meiqin , Huang Mengxing
Published: July 2020

This paper presents and analyzes S-tapered fiber probe structures. Cutting a conventional S-tapered fiber and coating its ends with gold film forms a highly reliable reflective layer. We acquire the reflection spectrum and use it to determine the refractive index (RI) sensitivity of this structure for various RIs and temperatures. The experimental results suggest that this S-tapered fiber probe structure has a maximum RI sensitivity of 1441 nm/RI unit in the RI range of 1.336–1.340 and a temperature sensitivity of about 0.7537 nm/°C. In addition, we analyze in detail the mechanism responsible for these high sensitivities.
A review of renewable energy generation using modified titania for photocatalytic water splitting
Authors: Aziz Aljar Mona A. , Zulqarnain Muhammad , Shah Afzal , Akhter Mohammad Salim , Iftikhar Faiza Jan
Published: July 2020

Hydrogen is contemplated as a promising renewable source of energy as compared to the fast depleting fossil fuels. The splitting of water for the generation of hydrogen is a perspective approach to produce sustainable fuel. Titanium dioxide is the most commonly used catalyst, the performance of which depends upon its electronic surface structure, bandgap, and type of radiation. This review article summarizes the state of the art developments about the photocatalytic activity of titanium dioxide for hydrogen production from the splitting of water. Special attention has been devoted to the addition of sacrificial reagents, metal/non-metal doping ions, and composite semiconductors in titania for absorbing visible light and enhancing charge separation on a catalyst surface for efficient energy generation of hydrogen fuel from water splitting.
Downscaling of sample entropy of nanofluids by carbon allotropes: A thermal lens study
Authors: Swapna M. S. , Raj Vimal , Sreejyothi S. , Satheesh Kumar K. , Sankararaman S.
Published: July 2020

The work reported in this paper is the first attempt to delineate the molecular or particle dynamics from the thermal lens signal of carbon allotropic nanofluids (CANs), employing time series and fractal analyses. The nanofluids of multi-walled carbon nanotubes and graphene are prepared in base fluid, coconut oil, at low volume fraction and are subjected to thermal lens study. We have studied the thermal diffusivity and refractive index variations of the medium by analyzing the thermal lens (TL) signal. By segmenting the TL signal, the complex dynamics involved during its evolution is investigated through the phase portrait, fractal dimension, Hurst exponent, and sample entropy using time series and fractal analyses. The study also explains how the increase of the photothermal energy turns a system into stochastic and anti-persistent. The sample entropy (S) and refractive index analyses of the TL signal by segmenting into five regions reveal the evolution of S with the increase of enthalpy. The lowering of S in CAN along with its thermal diffusivity (50%–57% below) as a result of heat-trapping suggests the technique of downscaling sample entropy of the base fluid using carbon allotropes and thereby opening a novel method of improving the efficiency of thermal systems.
One-step fabrication of a superhydrophobic copper surface by nano-silver deposition
Authors: Zhu Jiyuan , Zhang Langping , Dai Xuanjun , Zhou Bin
Published: July 2020

A bionic superhydrophobic coating with good corrosion resistance was prepared by one-step nano-silver deposition on a copper substrate. The superhydrophobic surface was covered with petal-like and coral-like micro/nano-structures. With the highest water contact angle of 169.9°, the superhydrophobic coating has good superhydrophobicity. The surface morphology, chemical composition, and wettability of the samples were characterized by scanning electron microscopy, Fourier transformed infrared, x-ray diffraction, and water contact angle measurement. The corrosion resistance tests showed a significant improvement on the superhydrophobic sample.
Study on track–soil traction using discrete element method simulation and soil bin test
Authors: Zhou Linxuan , Gao Jingwei , Cheng Pan , Hu Cheng
Published: July 2020

The soil ground with low moisture content has the mechanical properties of low viscosity and high friction, which have a great influence on the traveling of a tracked vehicle. In this paper, a movement model of the rigid track on low moisture soil is established based on the discrete element method (DEM) simulation. The soil simulation model was verified by the triaxial compression test. The traction simulation of the track under different vertical stress was carried out, and the traction performance of the track was analyzed by combining with the results of the soil bin test. The analysis shows that the tractive effort increases with the increase in vertical stress. The tractive effort distribution of the track is basically the same as the shape of the bottom of the track, and the tractive effort on both sides of the track cannot be ignored. The average error of tractive effort in simulation is 3.94%. DEM simulation can reproduce the mechanical properties and the discontinuous nature of low moisture soil particles under dynamic load, which is suitable for the numerical study of the interaction between the track and soil.
Rayleigh–Taylor instability in porous media under sinusoidal time-dependent flow displacements
Authors: Elgahawy Y. , Azaiez J.
Published: July 2020

Linear stability analysis and nonlinear simulations have been carried out to analyze the Rayleigh–Taylor instability in homogeneous porous media under time-dependent flow displacements. The flow processes consist of a sinusoidal time-dependent velocity characterized by its period (T) and amplitude (Γ) and ensure that the same amount of fluid is injected over a full flow period. A new, more efficient approach to determine instability characteristics has been developed for the stability analysis of these time-dependent injection flows and showed a growth rate that varies in time like the displacement velocity. The effects of the period T and amplitude Γ as well as the fluids’ viscosity (R) and density differences (ΔG) have been analyzed. Consistent with constant injection displacements, a larger ΔG leads to stronger instabilities. Furthermore, it is found that a larger R tends to attenuate the instability during extraction and soaking periods and to enhance it during injection. This study also revealed that for a given total injection time, the time-dependent flow can be less or more unstable than its constant injection counterpart. In particular, for Γ < −1, larger periods lead to stronger instabilities with longer more developed fingers. For Γ > 1, on the other hand, it is found that larger periods tend to attenuate the instability resulting in a smaller number of fingers and a more diffused front. Flows with unit amplitude (Γ = 1) exhibit the same qualitative trends as but are overall more unstable than their counterparts with Γ > 1.
Internode elongation pattern, internode diameter and hormone changes in soybean (Glycine max) under different shading conditions
Authors: Zhang Rui , Shan Fuxin , Wang Chang , Yan Chao , Dong Shoukun , Xu Yao , Gong Zhenping , Ma Chunmei
Published: July 2020

Internode length and diameter in soybean (Glycine max (L.) Merr.) are closely associated with lodging. The pattern of internode elongation and increase in internode diameter and factors involved were studied in two soybean cultivars, HN48 (tall-stem cultivar) and HN60 (dwarf cultivar), in the growing seasons of 2017 and 2018. Four treatments included natural lighting, shading of the apical meristem, covering of all internodes with aluminium foil, and whole-plant shading with plastic shading nets. When the number of internodes (N) on the main stem was >3, internode N began to elongate. Internode N – 1 exhibited the most rapid elongation, and internode N – 2 elongated slowly. Internode N – 3 stopped elongating, but the increase in internode diameter did not cease as internode elongation stopped. Shading the soybean apical meristem, the stem, and the whole plant all led to internode elongation. Different shading conditions did not alter the pattern of internode elongation. Soybean stem and apical meristem were both light-sensitive tissues. With an increase in shading, internode length increased, whereas internode diameter decreased. Contents of gibberellic acid (GA3) and salicylic acid in the stem also increased, but abscisic acid content decreased. Shading reduced the size of starch grains but increased the number of osmiophilic granules in the chloroplast. Elevated GA3 level was the main cause of the changes in internode length and diameter induced by shading. These results suggest that reduction in GA3 synthesis and enhancement in carbohydrates formation could a strategy for soybean plants to avoid lodging.
A corpus study ofkasama‘companion’ in Tagalog
Authors: Klimenko Sergei
Published: July 2020

This paper presents a corpus-based study of a number of different types of previously undescribed constructions formed with the Tagalog nounkasama‘companion’. Apart from independent and attributive uses,kasamafrequently occurs as the predicate of an adjunct clause that can introduce a comitative participant, a semantically depictive secondary predicate, an event-oriented adjunct, or a predicative complement. The study analyses the frequency ofkasamain all of these types of constructions and looks into their specific properties. This includes: the semantic distinction between additive and inclusory constructions withkasama; animacy agreement between arguments ofkasamain additive constructions; variation in case marking of arguments ofkasama; the preponderance of the absence of linkers – commonly known to introduce adverbial clauses in Tagalog – which are used to attach thekasamaclause to the main clause; attested controllers of thekasamaclause; positions available for thekasamaclause in the sentence. Variation in case marking and compatibility with linkers suggests a classification of Tagalog adjunct clauses similar to that of Tagalog adverbials and prepositions. There is also some evidence to believe thatkasamais being grammaticalized as a preposition. Comitative and semantically depictive constructions withkasama, which account for a quarter of the corpus sample, have never been studied before, despite the fact that Tagalog is included in several typological studies on comitative and depictive constructions.
Is inhibition involved in the processing of opaque compound words?
Authors: Park Juana , Sana Faria , Gagné Christina L. , Spalding Thomas L.
Published: July 2020

We examined whether inhibition skills were recruited during the processing of compound words. Using an individual differences perspective, we analyzed whether participants’ scores on the Stroop test predicted performance on lexical decision tasks involving compound words varying in their level of semantic opacity. The results show that inhibition is involved in the comprehension of fully opaque (e.g.,hogwash) and fully transparent (e.g.,blueberry) compound words, but we found no evidence for such an effect in the comprehension of partially opaque compound words (e.g.,strawberry,jailbird).
Negotiating embodied space in anxiety narratives
Authors: Knapton Olivia
Published: July 2020

In recent years, studies from social/cultural geography and social psychology have shown the importance of the subjective experience of space in anxiety disorders. This study investigates how lived space in anxiety is discursively negotiated in interactional narratives, with a focus on the co-construction of time, physical space and epistemic modality, and the ways in which metaphors contribute to the representation of spatial experience. The data are two case studies taken from television programmes in which a figure in the public eye is being interviewed about their experiences of anxiety. The analysis showcases two distinct kinds of lived space in anxiety, one in which the self is continually moving through a space experienced as too expansive, and another in which other people/entities are moving around the self in a space experienced as too small. Both experiences involve spatial responses that serve to bring some relief from anxiety. The analysis also has methodological implications by exemplifying how metaphors feed into spatial gestalts that are collaboratively constructed as narratives unfold in situated interaction.
A mixed-method analysis of image-schematic metaphors in describing anger, anxiety, and depression
Authors: Yu Yating , Tay Dennis
Published: July 2020

The importance of metaphor in psychotherapy and counseling has been shown by a growing number of studies.
Image-schematic metaphors, which derive from experience of sensory processes and space, are potential resources for
conceptualizing major themes like anger, anxiety, and depression in therapeutic discourse. To test the potential correlation
between image-schematic metaphors and the themes of anger, anxiety, and depression, this study employs a mixed-method approach,
integrating corpus linguistics techniques, discourse analysis, and statistical analysis, to examine a specialized corpus of
therapeutic transcripts which contains approximately three million words. The findings show that containment, force,
path, and vertical orientation are the most frequent types of image-schematic metaphors for describing the
therapeutic themes of anger, anxiety, and depression in the corpus, and there is a significant correlation between the two
variables (i.e., “types” and “themes”). This study has implications for how image-schematic metaphors can be used to facilitate
the descriptions of anger, anxiety, and depression in therapeutic conversations.
The ‘transformative’ power of ‘integrated metaphor’ in counselling
Authors: Ferrari Federica
Published: July 2020

Given the centrality of metaphor in the (re)structuring of experience (Burns,
2005; Loue, 2008; Roffman, 2008)
and of bodily experience to the notion of conceptual metaphor in cognitive theory (Lakoff
& Johnson, 2003 [1980]; Lakoff, 1993; Gibbs, 2006), this paper investigates the ‘transformative power’ of metaphor in ‘talking cure’
practices – Counselling and Psychotherapy – to implement its application potential. An experimental integrated “metaphor-based and
-driven” model is presented by adapting textual identification procedures (Steen, 1999;
Ferrari, 2007; Pragglejaz, 2007) to an
integrated psychological approach (Rogers, 2003 [1951]; Perls, 1951) in order to
further develop metaphor transformation guidelines. The ‘M’ psycho-test had been created to evaluate the power of metaphor in
counselling sessions in a diachronic perspective, providing both qualitative and quantitative data. Some preliminary cases (e.g.
‘the frog’, ‘eating’, ‘the hare’, ‘the desolated land’) are presented, with relative Transformational score, as examples of test
application and metaphor potential. Test evidence has allowed for quantitative and qualitative observations. The evidence gathered
shows: (1) Applying a metaphor-based experimental integrated approach can offer alternative for action in the practice; (2)
Measuring the transformational power of metaphor through ‘M’ psycho-test can offer further degree of awareness for both counsellor
and client.
Rewriting burnout as metaphor
Authors: Johnson Carissimo Melissa
Published: July 2020

Today’s healthcare professionals shoulder consequences of budget cuts, staff shortages, longer hours and a
growing, aging patient population. To address support for both patients and staff in this challenging context, the kidney dialysis
unit of a major Italian hospital was chosen for a three-phase pilot study of Metaphoric Affect Processing (MAP). MAP is a
metaphor-based interview technique designed to enhance wellbeing in hospital settings by facilitating the identification,
verbalization and regulation of affect as metaphor. The subject of this article is Phase 1 of the study, which focused on
mitigation of burnout symptoms among peritoneal and hemodialysis nurses. In Phase 1, nurses were offered weekly group sessions of
MAP training. All participants learned to use codified, “poetic” dialogue to explore, share and metaphorically “rewrite”
present-moment feelings. By the end of training, a number of nurses also qualified as MAP facilitators themselves. Nurses’
pre-training burnout levels were measured in subcategories of depressive anxiety, loss of empathy, and reduced sense of personal
achievement. Assessment after MAP training confirmed nurses’ self-reports of having engaged metaphor to address these aspects of
burnout, reducing stress levels, increasing empathy among colleagues and expanding perspective. Phase 1 outcomes suggest that MAP
may be an effective intervention to boost wellbeing for healthcare workers at high risk for burnout, and merits further study.
This article also offers an overview of MAP’s early development with patient populations in cancer treatment and acute care
psychiatric settings.
Cause analysis of transverse breakage of ultra high-strength steel shell after hydraulic blasting test
Authors: Wang H Y , Wang X , Yao Ch Ch , Liang X P , Zh Ren Zh , Chen X Y , Zhou F L , Wi Tong Sh
Published: July 2020

To ensure product quality, the inspection and analysis were carried out on the ultra high-strength steel welded shell with transverse rupture after qualified hydraulic blasting test. Firstly, we carried out spot investigation of hydraulic blasting test, breakage morphological analysis, investigation on production technology, reexamination of wall-thickness and X-ray film of welding joint; in case of different opinions on fast analysis, then, we carried out contrast detection and analysis on stripe of fracture, metallographic analysis on cross section of welding joint, TEM detection and analysis on fracture, and inspection and analysis on welding size and offset. The analysis results showed that, the transverse rupture of test sample after hydraulic blasting test was caused by the failure of part incomplete joint penetration on welding joint, which was due to welding arc deviation. Therefore, with the improvements of welding equipments, tooling and operation methods to prevent radial and weld offset, the welding quality was assured and improved.
The influences of annealing on surface morphology and microstructure of NdFeB thin film
Authors: Guo Z Z , Cao J W , Yan D M , Liu F F , Zhang C , Guo J B , Fu Y D
Published: July 2020

NdFeB thin films are produced by DC magnetron sputtering. The influences of annealing on surface morphology and microstructure of NdFeB thin films are studied in this paper. The result shows that the formation of Nd2Fe14B is prevented by depositing film directly on the substrates. Nd2Fe14B phase exists in crystalline films with Mo as a buffer layer and protective layer. Mo is a good material for being a buffer layer and protective layer. The (110) oriented texture of Mo is formed on (100) mirror polished Si after annealing. The deposited films are amorphous. SEM results show that the grain size is fine and uniform after annealing. Atomic Force Microscope investigation reveals that the film is smoother and denser after annealing. It is found that the films are still amorphous with annealing temperature below 400 °C, and the films begin to crystallize after annealing at 500 °C; the films annealed at 600 °C are fully crystallized.
Investigations on the influence of one and two-sided jet deflector on acoustic environment of multi-nozzle launch vehicle at lift-off
Authors: Xing Ch L , Le G G , Zhao Ch F , Zheng H
Published: July 2020

To study the acoustic environment of multi-jet impinging the jet deflector when the launch vehicle takes off, a compressible flow model of gas-air is established. The turbulence equation of scale-adaptive simulation (SAS) and the acoustic analogy method (FW-H) are solved numerically by using the second-order Roe scheme. The jet noise of a single rocket engine is numerically simulated. The error between numerical results and experimental data is within 3dB, and the reliability of the numerical method is verified. On this basis, the flow field and acoustic environment of the multi-nozzle launch vehicle are studied, and the effects of the jet deflector configurations on the acoustic environment of the vehicle are analyzed. The results show that, compared with the one-sided jet deflector, the two-sided jet deflector can reduce the overall sound pressure level around the vehicle by up to 6.6%. For the one-sided jet deflector, the overall sound pressure level of the receivers at the outlet of the jet deflector is larger than that of the other side. The analysis method and research results in this paper provide reference for predicting the acoustic environment of the launch vehicle and improving the acoustic environment.
The design of low-velocity penetrating equipment for high-energy explosives
Authors: Mei FENG
Published: July 2020

Accident scenarios involving explosive workers handling cased charges can result in low-velocity impact incidents. A series of low-velocity penetrating safety researches and experiments should be performed to high-energy explosives, and to determine whether such a penetrating impact can cause ignition and violent reaction, and to demonstrate heat generation mechanisms of low-velocity penetrations. This design of low-velocity penetrating equipment seeks to imitate the accident scenarios, perform safety researches and experiments, and demonstrate heat generation mechanisms of low-velocity penetrating for high-energy explosive. The structure design, controller design, control software design and test effects were elaborated in this paper.
Research on joint simulation technology of fire dynamics and servo control of self-propelled antiaircraft gun during moving
Authors: Gao X K , Gu B , Zhou C J , Liu J
Published: July 2020

Taking self-propelled anti-aircraft gun as the research object, this paper presents a joint simulation method of shooting dynamics and servo control during the course of self-propelled anti-aircraft gun. Aiming at the matching between structural parameters and servo control parameters of self-propelled anti-aircraft gun, an evaluation and optimization design method is proposed. The platform of the joint simulation system of dynamics and servo control is mainly composed of road-body-turret dynamics model, fire control module, elevation control compensation module, azimuth control compensation module and motor module. The control compensation module realizes the control strategy by PID (Proportional-Integral-Differential) control of position and speed loop. The motor module achieves the system control torque output through the current loop and the motor. These modules constitute the joint simulation design model of dynamics and servo control. By comparing the output of the simulation system with the actual firing test results of self-propelled antiaircraft gun, the effectiveness of the method is verified by the firing line error analysis under different experimental conditions. This method can be used to evaluate the tracking accuracy of the system at the design stage, which is helpful to reduce the development cost and shorten the development period.
Numerical simulation for high speed oblique water entry of different density projectiles
Authors: Mu Q , Xiong T H , Wang K J , Yi W J , Jun G
Published: July 2020

To explore the effects of material density on the cavitation flow field of a projectile entering water at an oblique angle at 300m/s, numerical simulations were conducted. The model was based on the finite volume method, VOF (Volume Of Fluid) multiphase model, Schnerr-Sauer cavity model, SST(Shear Stress Transfer) k-ω turbulence model and dynamic mesh method. The evolution laws of cavity shape, motion characteristics and hydrodynamic characteristics of water entry are analyzed. The research results show that the numerical calculation method can effectively simulate the change of cavity shape during the water entry of the projectile. The larger the density is, the smaller the diameter of the cavity formed after entering water is; the longer the cavity is, and the smaller the diameter of the cavity opening is; The peak value of pressure on the surface of projectile with different density is the same at the moment of entering water, but the projectile with larger density experiences a slower rate of the surface pressure decline; Moreover, the larger the density, the smaller the acceleration peak value of the projectile at the moment of entering the water, the slower the velocity decay after entering the water, and the deeper underwater at the same time.
Continuous sliding mode control for gun position servo system
Authors: Zhang Gaosheng , Zhang Zhipeng , Han Chongwei , Gu Shuanghao , Wang Tianshi , Zhang Pengfei
Published: July 2020

With the development of military technology and changes in the war situation, modern warfare has higher requirements for the accuracy and speed of gun firing. The control performance of the gun position servo system directly affects the accuracy and speed of the gun firing. In order to improve performance of the gun, the sliding mode control is investigated for the gun position servo system. Sliding mode control has advantages of simple structure and good robustness against uncertain system parameters and disturbance. But discontinuous sign function in the classical sliding mode control method will lead to chattering of the system. To address the shortcoming of chattering in the traditional sliding mode control, a continuous sliding mode control algorithm is investigated in this paper. Finally, numerical simulations are performed to illustrate the efficiency of the theoretical results.
Research on muzzle dynamic analysis of an overhead weapon station with the viscoelastic elastomer damper
Authors: Mao B Q , Wang Z Q , Chang L , Yang Y Y , Xu Z H , Han X P
Published: July 2020

Live firing tests are difficult to realize, thus it is not clear whether the viscoelastic elastomer damper can effectively reduce the recoil force and recoil displacement, which determines the firing accuracy of the overhead weapon station. This paper constructed a rigid-flexible coupling dynamics model of overhead weapon station with the viscoelastic elastomer damper. The dynamic simulation parameters of the damper were determined according to the static pressure test results. A characterization method of the firing dispersion of the overhead weapon station was then proposed. Additionally, the influences of the viscoelastic elastomer damper and the spring damper on the muzzle dynamic characteristics and firing dispersion of the overhead weapon station were studied. The results show that: the recoil displacement and the recoil-return time with the viscoelastic elastomer damper were respectively reduced by 69.83% and 33.50% compared to the spring damper; By contrast the spring damper, the horizontal and vertical dispersion standard deviations of the overhead weapon station with the viscoelastic elastomer damper at different firing conditions were respectively decreased an average of 39.48% and 43.68%, while the firing dispersion was increased by an average of 41.89%. These results prove that the viscoelastic elastomer damper can significantly reduce and shorten the recoil displacement and the recoil time of the machine gun overhead weapon station, effectively reduce the muzzle jump and improve the firing accuracy of the overhead weapon station.
New evaluation method for shared firing table of two ammunition types
Authors: Zhongxiang’ Xu , Lixin Chen
Published: July 2020

In this paper, a statistical function is proposed for the test of Shared Firing Table of two ammunition types, regarding the problems of two common evaluation methods of Shared Firing Table in evaluating Shared Firing Table of two ammunition types, based on basic concept of Shared Firing Table and the difference in characteristic values of dispersion ellipses of two ammunition types at drop point, and the maximum allowable value between two dispersion ellipse centers and the criterion of test evaluation are derived from the preset probability value of two ammunition types group dropping into dispersion ellipse overlapping region; through application of relevant sample size calculation formula and OC (Operating Characteristics) curve (OC curve), the relationship between the test efficiency and the minimum test sample size is solved, so as to provide an effective means for the decision and planning of sample size before test and the determination of test efficiency after test; and the validity and practicability of Shared Firing Table evaluation method established herein are verified by comparing the shooting test results of 1 group x 7 shoots, and the firing table of basic howitzer type - explosive warhead bomb.
Simulations on the reactive material projectile coated by explosively formed penetrator
Authors: Ma H B , Guo H G , Su Ch H , Zheng Y F
Published: July 2020

A typical shaped charge structure enhanced by reactive material projectile is established by AUTODYN-2D software. The formation and penetration processes of reactive inner core-wrapped compound EFP are simulated and analyzed. The results show that the segment liner with thick axis and thin edge becomes a penetrator with a lower velocity in the axis and a higher velocity in the edge under the shaped charge effects, which leads to EFP flipping forward and coating the reactive material projectile. The impacts between liner and reactive material projectile further increase the velocity difference between the axis and the edge, resulting in a better coating effect. The formation process is divided into three phases, including impact, coating and stretching. Then, the damage process contains penetration and deflagration of the following reactive material projectile. The liner thickness difference, curvature radius of the segment liner and radius of the reactive sphere all have important influences on formation and penetration of the reactive inner core-wrapped compound EFP.
Study on the functional rule of exploding foil multi-point synchronous explosive
Authors: Qin G Sh , Wang K X , Cao H Y , Wang Y , Zhou M , Tong H H
Published: July 2020

In order to study the effect of series initiation and parallel initiation on multi-point synchronous initiation of EFI (Exploding Foil Initiator, EFI), two-point series and two-point parallel electric explosion, three-point series and three-point parallel electric explosion of exploding foil were tested in this paper. The electrical explosion parameters for synchronous initiation of exploding foil two-point in series and two-point in parallel were tested also. The electric explosion parameters of exploding foil varies with the initiation voltage were analyzed. The effects of series initiation and parallel initiation on the performance of exploding foil multi-point synchronous initiation were obtained. The initiation sensitivity test of three-point series EFI and four-point hybrid EFI was carried out. The experimental results agree well with the analysis law. The research results show that series initiation is beneficial to improve the consistency of initiation conditions at each point on the condition of exploding foil multi-point initiation, is beneficial to improve the synchronization of multi-point initiation. But it’s adverse to the full release of system energy when the number of series initiation points is large. Parallel initiation is beneficial to improve the system energy utilization. But the explosion synchronization relatively poor when system energy is low. The explosion synchronization of exploding foil will be better when system energy increase. It’s benefits to increase the consistency of initiation conditions at each point of exploding foil, benefit to increase the system energy utilization and reduce system firing energy that adopt reasonable combination of series and parallel, when the number of initiation point is large and system energy is sufficient.
Explosive synthesis: novel intrinsically safe method and application with micro-channel reactor
Authors: Weifei Yu , Zhiyong Wei , Ruijuan Xu , Mei Feng , Sen Li , Guangcheng Yang
Published: July 2020

Novel Micro-channel method was introduced into explosive synthesis process. The method was discussed hereby with its intrinsic safety including marvelous inner-structure, high heat-transfer efficiency, and high mass-transfer efficiency compared to traditional kettle-based method. Micro-channel reactor for explosive synthesis was established with high precision control, the temperature difference of oil flow between import and export of micro-channel reactors was measured to be no more than 3°C, and the flux fluctuation of reactant flow were measured to be no more than 0.1ml/min. Micro-channel reactor was experimented with TATB explosive synthesis process. Nitration reaction showed no residue of raw material PG and 91.62% HPLC area of target material TNPG, alkoxylation reaction showed no residue of raw material TNPG and 98.01% HPLC area of target material TETNB, amination reaction showed 5.28% HPLC area of raw material and output of target material TATB. It was concluded to be verifiable including micro-channel method, the apparatus, and application in TATB synthesis process
Experimental study on thermomechanical behaviour of polyurea under dynamic compressive loading
Authors: Liu Q , Wang Ch J , Zhang Y L , Chen P W , Su J J , Zhang F
Published: July 2020

Polyurea is one kind of protective materials, which has been extensively used to enhance the survivability of structures under blast loading. To study the thermomechanical behavior of polyurea, compressive tests are conducted using a split Hopkinson pressure bar (SHPB) apparatus at high strain rates. An infrared thermograph is employed to observe the temperature rise. The experimental results show that the compressive stress strain response of polyurea presents a sensitivity of strain rate and strain. In addition, the deformation energy can transform to heating resulting in temperature increases under dynamic loading. Thus, the thermal softening decreases the mechanical behavior of polyurea, corresponding to temperature rise. The strain rate and length of strike bar can remarkably influence the variation about temperature rise.
Numerical simulation to determine the shaped charge jet-slug interface
Authors: Jing Y D , Chen Q , Chang B , Xue B , Tang Ch , Shu D Y , Liu F W
Published: July 2020

In order to determine the interface of shaped charge jet-slug, numerical simulation of the shaped charge jet forming process is carried out by non-liner finite element numerical simulation. A plurality of gauge points is arranged in the thickness of the liner, and the velocity and pressure time history of different gauge points is obtained in the jet forming stage. The result show that in the process of shaped charge jet formation, obvious velocity and pressure difference in gauge point is observed. By dividing the boundary between the slug and jet of different sets of gauge points, the corresponding area of jet and slug can be determined on the liner. The numerical simulation to determine the shaped charge jet-slug interface can be used to evaluate the performance of different shaped charge design and provide guidance for shaped charge design.