bluuebunny/crossref_metadata_2025 huggingface dataset:
Membrane-selective nanoscale pores in liposomes by a synthetically evolved peptide: implications for triggered release
Authors: Sun Leisheng , Hristova Kalina , Wimley William C.
Published: June 2021

Peptides that form nanoscale pores in lipid bilayers have potential applications in triggered release. The peptide M159 releases macromolecular cargo from PEG-stabilized liposomes without affecting living cells.
Aldehyde-catalyzed epoxidation of unactivated alkenes with aqueous hydrogen peroxide
Authors: Triandafillidi Ierasia , Kokotou Maroula G. , Lotter Dominik , Sparr Christof , Kokotos Christoforos G.
Published: June 2021

An atropisomeric two-axis aldehyde is capable of catalysing the organocatalytic epoxidation of unactivated alkenes using hydrogen peroxide as the oxidant.
Techno-economic analysis of a two-step fermentation process for bio-butanol production from cooked rice
Authors: Ozturk Abdullah Bilal , Arasoglu Tulin , Gulen Jale , Cheng Shou , Al-Shorgani Najeeb Kaid Nasser , Habaki Hiroaki , Egashira Ryuichi , Kalil Mohd Sahaid , Yusoff Wan Mohtar Wan , Cross Jeffrey Scott
Published: June 2021

Biobutanol was produced from cooked rice by utilizing two steps: microbial saccharification followed by aerobic acetone–butanol–ethanol (ABE) fermentation. The scaled-up process was simulated via SuperPro Designer®.
EDTA-mimicking amino acid–metal ion coordination for multifunctional packings
Authors: Tao Kai , Orr Asuka A. , Hu Wen , Makam Pandeeswar , Zhang Jiahao , Geng Qiang , Li Boxin , Jakubowski Joseph M. , Wang Yancheng , Tamamis Phanourios , Yang Rusen , Mei Deqing , Gazit Ehud
Published: June 2021

An amino acid complexes with metal ions in a manner similar to EDTA, showing significant catalytic and piezoelectric properties. The results suggest that metabolic molecules can be developed as EDTA-mimic bio-chelators for various applications.
Research into the Contribution Rate of Technological Progress to the Industrial Economic Growth of Xinjiang
Authors: Wen Lu , Rong Zhang , Xiao Bai
Published: June 2021

Since the Silk Road Economic Belt initiative was put forward in 2013, the industrial structure of Xinjiang has become increasingly rationalized, and Xinjiang’s economic development has entered a stage of rapid development. Based on the Solow residual value method, this paper uses the gray correlation model to estimate the elastic coefficient of capital and labor input and calculates the contribution rate of technological progress in 25 industrial sectors in Xinjiang. The research results show that more than 50% of the industrial sector in Xinjiang contributes more than 50% to technological progress, and Xinjiang’s economy has entered a period of intensive rapid development.
How Digital Economy Helps Rural Poverty Alleviation and Rural Revitalization in China
Authors: Zhang Xun , Luo Renfei , Shi Ying , Shangguan Yanzhen
Published: June 2021

In the context of the implementation of the rural revitalization strategy, the development of the digital economy closely connects with it. The realization of rural revitalization needs to make full use of the advantages of the digital economy to promote the process of rural revitalization. The digital wave is a huge opportunity for the poor to bridge the gap between rich and poor, seize digital opportunities, share digital dividends, achieve sustainable poverty alleviation, and prevent intergenerational transmission of poverty. The article will focus on two aspects of rural e-commerce and mobile payment. Through the discussion of the aspects, this paper gives the suggestion to the government, platforms, enterprises and farmers to work together to promote agricultural development and realize industrial digitalization by using existing resources.
Analysis on Credit Risk Assessment for Accounts Receivable Supply Chain Financing Based on Credit Insurance
Authors: Bi Keran , Hua Zheng , Shi Qinwen , Zhu Yu
Published: June 2021

This paper studies the model of accounts receivable supply chain financing based on credit insurance from the perspective of banks. First of all, the paper analyzes two different financing modes of the innovative model - the pledge financing mode and the factoring financing mode. Secondly, the paper explains the sources of credit risks for accounts receivable supply chain financing under credit insurance, and the necessity of using credit insurance. The sources of credit risks mainly include: the enterprises’ comprehensive strength under systemic and non-systemic risks, status of accounts receivable, supply chain operation, performance of insurance companies, and so on. In addition, based on the credit risks explained in this paper, the risk assessment system and the credit risk assessment model are built. At the end, the paper offers three suggestions for the banks’ financing risk control: bank should carefully check the policy’s exclusions clauses; bank must carefully check the authenticity of accounts receivable; bank can use dynamic monitoring on qualification checking for financing enterprises, core enterprises and insurance companies.
The Impact of the Digital Economy on Corporate Taxation From the Perspective of Supply Chain
Authors: Zhang Chen , Gao Liting
Published: June 2021

Supply chain is the unification of modern information flow, capital flow and logistics. Corporate tax management is an important part of corporate financial management, and its management results will have a direct impact on corporate development. In the current environment of rapid social and economic development, taxation management has penetrated into the entire supply chain of an enterprise, and has played its due value to the business development of the enterprise. Based on the perspective of the supply chain, this article studies the impact of the digital economy on corporate taxation, focusing on the analysis of the problems in corporate taxation management, and puts forward relevant suggestions based on the analysis results for reference.
Clustering analysis of the distribution characteristics of unobserved economic regions in China——Based on multi-indicator panel data
Authors: Fan Yang
Published: June 2021

The existence of unobserved economy is one of the important factors affecting GDP calculation. This paper uses the provincial panel data from 2010 to 2019 in China, and adopts the method of principal component feature extraction to carry out cluster analysis on the multi-indicator panel data. This method preserves the dynamic characteristics of the panel data, calculates the comprehensive score of each eigenvalue, and gives weight to the eigenvalue by using the entropy method, so as to optimize the clustering results representing the eight indicators of the unobserved economy. Through the analysis, it is found that the regional development of China’s unobserved economy is obviously different, and each type has different influencing factors. This result has important practical significance for different regions in China to formulate differentiated unobserved economic governance policies. This also helps to make better use of resources and develop an energy-saving economy.
The impact on the equity value of listed companies pledge - A Case Study of La Chapelle
Authors: Liu Fang
Published: June 2021

With the rapid development of China’s securities market, bank loans as an important channel of enterprise financing has been unable to meet the capital needs of most enterprises, this article is based on the A-share main board listed company and equity pledge ratio as the research object, a case study of rashabel’s equity. It is concluded that the value of the company is inversely proportional to the proportion of the allocated equity. We should distribute equity reasonably, balance the power among shareholders, so as to improve the efficiency of governance and strengthen the supervision of large shareholders.
Modernization Versus Dependency Approaches to Sustainable Development--Based on the UN Report 2019
Authors: Deng Siyuan , Zhang Jingxing
Published: June 2021

The essay tends to focus on the investigation into the changing sustainable development trend. It is important to know which areas have seen the greatest progress and which areas have stalled or even regressed around the globe. The researchers will compare and combine the modernization theory and dependency theory to figure out the potential factors which result in the different levels of achievement between all the 17 sustainable development goals (SDG). The researcher team are more likely to adopt both qualitative method and quantitative method to ensure the accuracy of the conclusion. In addition, due to the fact that the primary data related to this topic is too broad to obtain, the scientific group will mostly employ secondary data from the United Nations to carry out the research. Most of the data in the essay are from various United Nations documents and reports to ensure the authenticity and objectivity of the data. It allows the researchers to pay more attention on the specific analysis. Lastly, the goal of this paper is to find out the basic laws of sustainable development by looking for the unique representative parts of the 17 SDG goals (Basic education, Food safety, Life below water, etc.) and analysing their development trends in the past few years. In addition, the researchers tend to work out suggestions and solutions to those problems.
Nonlinear relationship between carbon market and energy market
Authors: Li Yan
Published: June 2021

This paper divides the energy market into energy futures market and new energy stock market. At the same time, the closing price of Shenzhen carbon emission rights is used to represent the carbon market price, the energy futures composite index of China Securities Exchange is used to represent the energy futures market price, and the stock price of new energy listed companies is used to represent the new energy stock market price. VAR model and MSVAR model are used to empirically study the relationship between the three variables and the nonlinear relationship between them. VAR model results show that there will be more complex relationship among carbon market price, energy company stock price and energy futures price. MSVAR model shows that the energy futures market, new energy stock market and carbon market present nonlinear and structural changes, and MSVAR model can better explain the nonlinear relationship among the three markets than traditional VAR model.
Spatial and temporal characteristics of carbon emissions from livestock farming in Yunnan province by state and city
Authors: Chen Rui , Chen Ji
Published: June 2021

The livestock industry is a pillar industry of the rural economy and an important industry of the national economy in Yunnan Province, so it is important to study the spatial and temporal characteristics of carbon emissions from the livestock industry in Yunnan Province for the development of a modern, lowcarbon and recycling livestock industry. This study draws on provincial greenhouse gas emission factors to calculate the carbon dioxide equivalents generated by enteric fermentation and manure management of cattle, sheep, pigs and poultry in each state and city of Yunnan Province. The results show that: (1) the total carbon emissions from the livestock sector in Yunnan Province decreased from 25, 643, 900 t in 2008 to 24, 758, 200 t in 2018, with an average annual carbon emission of 30, 534, 500 t and an average annual growth rate of The average annual growth rate was 0.35%, showing a characteristic of “rising first then falling”. (2) In terms of spatial and temporal evolution, the layout of the low and high livestock carbon emission areas in Yunnan is stable, while the medium and high livestock carbon emission areas fluctuate frequently and the spatial and temporal differences in carbon emissions are obvious. Finally, based on the conclusions, targeted countermeasure suggestions are put forward.
Public Finance Policy and Technological Innovation in China
Authors: Li Yaling , Li Yuting , Liu Rui
Published: June 2021

Technological innovation is the core power to promote economic growth, and public financial policy plays an important role in stimulating enterprises to carry out technological innovation. The new technological revolution has not only provided opportunities but also posed serious challenges to developing countries. We must adapt to the development trend of the new technological revolution, change the traditional model of economic development, formulate new development strategies, improve existing public policies, constantly raise the level of science and technology, and embark on the road of making China a technologybased country. By analyzing the relationship between technological innovation and public financial policy, this paper draws out the shortcomings of China’s existing fiscal policy in promoting technological innovation, and makes a comparative analysis of the fiscal policy of the United States and draws on its experience, so as to get the technical innovation suggestions under China’s public financial policy.
Research on Industrial Design Method Based on Shape Symbolic Language of Stacked Stone in Yangzhou Geyuan Garden
Authors: Liu Wenming , Chen Penghui
Published: June 2021

Stone stacking represents a high concentration and replication of natural mountain landscape, while stone stacking art serves as a significant element and a key tool in traditional Chinese landscape design. This paper presents the artistic background and characteristics of stone stacking. Through the analysis of the form symbol and design method of “spring, summer, autumn and winter”, this paper proves that the application of cultural symbols in product design is effective and can be used as a method of auxiliary design.
Research and Design of Reverse Logistics Network of Used Power Battery Based on Heuristic Algorithm
Authors: He Longyu
Published: June 2021

This paper starts with the rapidity of new energy vehicles and the hazards of power battery disposal, and puts forward the importance of the construction of a reverse logistics network for used power batteries, and then analyzes the characteristics and operating modes of the reverse logistics network. Based on the results of the analysis, a heuristic is proposed. The algorithm uses a two-stage algorithm to solve the problem of waste reverse logistics location-transportation, and proposes the design and construction of a reverse logistics network for waste power batteries, so that the recycling of waste power batteries can be better carried out.
Research on the Main Body of Rural Economic Innovation Based on the Perspective of Public Policy
Authors: Hu Die , Hu Menghan , Chen Yuxue , Yuan Fang
Published: June 2021

Migrant workers, college students, urban workers, entrepreneurs and technical personnel who love agriculture and are willing to return to countryside are the main body of rural economic innovation. They are a new driving force for promoting the development of agricultural and rural economy and solving the problems of agriculture, rural areas and peasants. The government has issued several policies to encourage these people to start businesses in countryside. However, whether the policy measures have achieved the expected policy objectives and whether they can effectively promote rural economic innovation are a question worth discussing. Taking the case Han chuan City of Hubei Province as an example, this paper uses field study to show the characteristics of the main body of rural economic innovation and explore the practical effects and existing problems of policies for promoting rural economic innovation. The results show that the multiplier effect of the main body of rural economic innovation has not really been played out. The main reasons include the limitation of policy making, inadequacy implementation of policy and insufficient incentives. Finally, it is concluded that the government should strengthen the training of entrepreneurial farmers, create a favourable industrial and policy environment and encourage high level and highly skilled personnel to come to countryside.
Research on the Correlation between Technological Innovation and Value Increase of Agricultural Companies Based on the Perspective of Company Life Cycle Theory
Authors: Yu Zhu , Zheng Hua
Published: June 2021

Technological innovation should be given full play, and R&D by agricultural companies should be given guidance. Because, for the purpose of increasing listed agriculture companies’ value, promoting the industry’s development, saving energy and resources in advanced agriculture productivity, such actions are of great significance. This paper takes agriculture companies listed in China’s A-shares from 2015 to 2019 as research samples, and makes empirical research on the influence of technological innovation on the value of agriculture companies in different life cycle stages. It is found that technological innovation does not significantly increase the companies’ value in their start-up and decline stages, while the situation becomes the opposite way in growth and maturity stages.
Research on Holographic Multidimensional Evaluation System of Suppliers in Pumped Storage Enterprises
Authors: Wang Hongliang , Pang Xiaoran , Wang Yeting , Zhang Yujian , Yin Xi , Chen Tong , Yao Yang
Published: June 2021

Based on the actual background of a pumped storage company, this paper researches and builds the supplier holographic multidimensional evaluation system. By building supplier data mart, it realizes supplier data integration and visual management. By building supplier portrait system, it reflects the comprehensive performance of suppliers in different business scenarios. By applying the supplier multidimensional holographic evaluation system, from the life long perspective of supplier management, this paper realizes intelligent comparison of qualification performance verification data, bidding assistant management, real-time control of performance process, supplier recooperation assistant decision and so on, so as to assure the company’s safe and stable operation.
A Tri-band Second-order Frequency Selective Surface Designing and Analysis
Authors: Shan Gao , Gao ChunYan , Pu HongBin , Chen ChunLan
Published: June 2021

In this paper, inspired from the technique of patch–aperture–patch, a novel tri-band frequency selective surface with second-order band-pass response in each operation band is presented. The design is implemented by cascading a two-dimensional periodic array of three square loops and an array of wire grids. The proposed structure composed of three metal and two dielectric layers acts as a spatial dual band microwave filter with large band separation. The predicted FSS has the merits of broadband response, excellent stability for different incident angles, and sharp roll-off at X-, Ku- and K-band, respectively. The simulation and measurement are carried out and discussed. The measured results agree well with the simulated ones.
Path selection for wind power in China: Hydrogen production or underground pumped hydro energy storage?
Authors: Li Hui , Yao Xilong , Tachega Mark Awe , Ahmed Dulal
Published: June 2021

Hydrogen production from wind power and energy storage from wind power are considered as effective measures to overcome the problem associated with wind curtailment. However, their further development is clearly constrained by the incurred costs. Hydrogen production from offshore wind power (HPFW), hydrogen production from onshore wind power (HPNW), and underground pumped hydro energy storage from wind power (UPHESW) are considered in this paper. This paper employs a life cycle cost analysis to calculate and compare the levelized costs of hydrogen production and energy storage in China. A sensitivity analysis is conducted to evaluate the influences of different factors on levelized costs. The results show that the levelized cost of HPFW is 1.44 times that of HPNW. The levelized cost of UPHESW is lower than that of traditional pumped hydro energy storage with the same installed capacity and also lower than that of UPHESW with the smaller installed capacity. The economic competitiveness between UPHESW and HPNW depends on the installed capacity of UPHESW. If it exceeds 453 MW, UPHESW is more economical. If it remains below 453 MW, HPNW is more economical.
Simulation study of influence of the outlet elastic baffle on pressure in arc chamber during the interrupting process of low-voltage circuit breaker
Authors: Yin Nairui , Liu Hongwu , Shi Zongqian , Guan Ruiliang
Published: June 2021

In this paper, a bidirectional fluid–solid interaction method is established to investigate the influence of the outlet elastic baffle on the pressure in the arc chamber in the breaking process of a low-voltage circuit breaker. Based on the computational fluid dynamic method, the flow model in the arc chamber is established. The model of the outlet baffle, with consideration of the nonlinear behavior, is established by the finite element method. By introducing dynamic grid technology, the interaction process of deformation of the outlet baffle and arc chamber pressure can be analyzed. A simple arc extinguishing chamber with an outlet baffle is designed, and experiments with a LC oscillating circuit are carried out. By using a high-speed camera and a pressure sensor, the deformation of the baffle and the pressure of the arc chamber are measured in the breaking process. The simulation model is verified by experimental results. It is worth noting that the flutter behavior of the elastic baffle was observed in the experiments and in the numerical simulation. Through simulation analysis, it is found that the flutter behavior is caused by the first-order mode of the elastic baffle under the excitation of arc chamber pressure.
Elucidation of the molecular interactions that enable stable assembly and structural diversity in multicomponent immune receptors
Authors: Fong Lam-Kiu , Chalkley Matthew J. , Tan Sophia K. , Grabe Michael , DeGrado William F.
Published: June 2021

Significance

Receptors that separate ligand recognition and intracellular signaling into separate protein subunits are ubiquitous in immunity. These subunits mix and match to create combinatorial functional diversity. The transmembrane domains of these receptors assemble through the interaction between two acidic and one basic residue on different helices. Using computational methods to study the DAP12-NKG2C receptor complex, we identified a polar motif in which a singly-protonated Asp-Asp pair forms a carboxyl-carboxylate clamp that clasps a charged Lys side chain in the membrane. This local interaction allows dynamic variations in other regions of the helices that tolerate sequence diversity of the interacting subunits in this class of receptors, which signal through multisubunit clustering rather than propagation of rigid conformational changes through the membrane.
C1q binding to surface-bound IgG is stabilized by C1r2s2proteases
Authors: Zwarthoff Seline A. , Widmer Kevin , Kuipers Annemarie , Strasser Jürgen , Ruyken Maartje , Aerts Piet C. , de Haas Carla J. C. , Ugurlar Deniz , den Boer Maurits A. , Vidarsson Gestur , van Strijp Jos A. G. , Gros Piet , Parren Paul W. H. I. , van Kessel Kok P. M. , Preiner Johannes , Beurskens Frank J. , Schuurman Janine , Ricklin Daniel , Rooijakkers Suzan H. M.
Published: June 2021

Significance

Antibody-dependent complement activation plays a major role in various pathophysiological processes in our body, including infection, inflammation, autoimmunity, and transplant rejection. In order to activate complement, antibodies should bind to target cells and recruit complement component C1. C1 is a large, multimolecular complex that consists of the antibody recognition protein C1q and a heterotetramer of proteases (C1r2s2). Although it is believed that interactions between C1 and IgGs are solely mediated by C1q, we here show that C1r2s2proteases affect the capacity of C1q to form an avid complex with surface-bound IgG molecules. Furthermore, we demonstrate that C1q–IgG stability is influenced by IgG oligomerization and that promoting IgG oligomerization improves phagocytosis of the pathogenic bacteriumStaphylococcus aureus.
The Patterson function as auto-hologram and graph enables the direct solution to the phase problem for coherently illuminated atomistic structures
Authors: Calvo-Almazán Irene , Fenter Paul
Published: June 2021

The coherent Patterson function, derived from the coherent scattering intensities from N atoms, can be described as an auto-holographic image, i.e., the superposition of N-holographic images in which each atom serves as the source of a different reference wave, and as a mathematical graph of the unknown structure. These insights indicate that the unknown structure is significantly over-determined by the inherent information content in a Patterson function by a factor of (N − 1)/2 (for non-degenerate structures), independent of dimensionality. However, we also show that the ability to resolve the distinct features in the Patterson function depends strongly on details of the experimental design (data range, sampling frequency, and dimensionality). This re-interpretation suggests that the coherent Patterson function provides a natural context for describing the information content in coherent scattering, reveals that there is no inherent phase problem for coherently illuminated pointwise structures, and enables the design of an algorithm which retrieves the structure directly from the Patterson function, without using error metric minimization.
High-fidelity resonant tunneling passage in three-waveguide system
Authors: Ma Rui-Qiong , Shi Jian , Liu Lin , Liang Meng , Duan Zuo-Liang , Gao Wei , Dong Jun
Published: June 2021

An N-stage three-waveguide system is proposed to improve the robustness and the fidelity of the resonant tunneling passage. The analytic solutions to the tunneling dynamics at the output are derived. When the number of subsystems increases, tunneling efficiency approaches to 100% in a large range and resonant tunneling is robust against variations in the phase mismatch and peak tunneling rate.
Raman phonon anomalies in Sr(Fe1–x
Co
x
)2As2
Authors: Yang Yanxing , Zhang Hewei , Zhuang Haizheng
Published: June 2021

Phonon anomalies have been reported in iron-pnictide superconductors indicating a diverse interplay between different orders in the materials. Here, we report Raman scattering measurements on Sr(Fe1–x
Co
x
)2As2 (x = 0 and x = 0.04) single crystals in the B
2g
symmetry with respect to a 1 Fe unit cell. Upon cooling, we observe a larger split (13 cm−1) of Eg
Raman phonon modes pertaining to in-plane Fe and As displacements as the crystals undergo the tetragonal-to-orthorhombic structural phase transition, although a considerable split (9 cm−1) has been reported in Ba(Fe1–x
Co
x
)2As2. Furthermore, the splitting of Eg
phonon modes is strongly reduced upon doping. We perform an order-parameter analysis revealing a similar doping dependence of Eg
phonon splitting as reported in other compounds of the 122 family, indicating these phonon anomalies widely exist in 122 iron-based superconductors and might share the same mechanisms.
First-principles study of structural and opto-electronic characteristics of ultra-thin amorphous carbon films
Authors: Liu Xiao-Yan , Wang Lei , Tong Yi
Published: June 2021

Most amorphous carbon (a-C) applications require films with ultra-thin thicknesses; however, the electronic structure and opto-electronic characteristics of such films remain unclear so far. To address this issue, we developed a theoretical model based on the density functional theory and molecular dynamic simulations, in order to calculate the electronic structure and opto-electronic characteristics of the ultra-thin a-C films at different densities and temperatures. Temperature was found to have a weak influence over the resulting electronic structure and opto-electronic characteristics, whereas density had a significant influence on these aspects. The volume fraction of sp3bonding increased with density, whereas that of sp2bonding initially increased, reached a peak value of 2.52 g/cm3, and then decreased rapidly. Moreover, the extinction coefficients of the ultra-thin a-C films were found to be density-sensitive in the long-wavelength regime. This implies that switching the volume ratio of sp2to sp3bonding can effectively alter the transmittances of ultra-thin a-C films, and this can serve as a novel approach toward photonic memory applications. Nevertheless, the electrical resistivity of the ultra-thin a-C films appeared independent of temperature. This implicitly indicates that the electrical switching behavior of a-C films previously utilized for non-volatile storage applications is likely due to an electrically induced effect and not a purely thermal consequence.
Controlled vapor growth of 2D magnetic Cr2Se3 and its magnetic proximity effect in heterostructures*
Authors: Zhang Danliang , Yi Chen , Ge Cuihuan , Shu Weining , Li Bo , Duan Xidong , Pan Anlian , Wang Xiao
Published: June 2021

Two-dimensional (2D) magnetic materials have aroused tremendous interest due to the 2D confinement of magnetism and potential applications in spintronic and valleytronic devices. However, most of the currently 2D magnetic materials are achieved by the exfoliation from their bulks, of which the thickness and domain size are difficult to control, limiting the practical device applications. Here, we demonstrate the realization of thickness-tunable rhombohedral Cr2Se3 nanosheets on different substrates via the chemical vapor deposition route. The magnetic transition temperature at about 75 K is observed. Furthermore, van der Waals heterostructures consisting of Cr2Se3 nanosheets and monolayer WS2 are constructed. We observe the magnetic proximity effect in the heterostructures, which manifests the manipulation of the valley polarization in monolayer WS2. Our work contributes to the vapor growth and applications of 2D magnetic materials.
Method of the numerical modelling of unstationary processes in the combustion chamber of a gas turbine engine
Authors: Savchuk A T , Yakovlev A A
Published: June 2021

Estimation of the stability margins of combustion processes in the combustion chamber of a gas turbine engine is a vital task of current subsonic and supersonic propulsion engineering and this article describes the approach to its Computational Fluid Dynamics simulation. The aim of the work is to create and verify a methodology for assessing the stability regimes of combustion processes in the combustion chamber of a gas turbine engine based on an artificial simulation of the excitation of non-stationary processes in the temperature-pressure parameters using “ANSYS Fluent”. The further comparison of the computed results and the real data of the physical experiment in the model device will take place to verify the method. During the research this methodology and a software product will be developed for computing the characteristics of the combustion processes before and after the excitation of the artificial unstable process. This technique, when verified, will allow to clarify the instability limits for specific operating modes (engine stall, flame suppression, lean flameout) of existing and projected gas turbine engines. The obtained numerical results allow us to make an assumption about the fundamental possibility of obtaining convergent solutions in close according with the future experimental data.
Stress state analysis of laminated shells with piezoelectric layers based on the refined theory
Authors: Nguyen L H , Firsanov V V
Published: June 2021

This paper presents stress state analysis of composite cylindrical shells bonded piezoelectric layers in the top and bottom surfaces. The laminated smart shell is subjected to electric potential and mechanical loading. The mathematical model of electroelasticity behaviour is based on the refined theory and virtual work principle. The governing differential equations are reduced to ordinary differential equations by means of trigonometric function expansion for displacement and electric potential. Operative method is used to solution of boundary problem. Stress-strain state of smart cylinder for electromechanical loads with clamped support is provided. Numerical results are presented showing the effect of boundary layer at clamped edges and comparison between the obtained results to the classical theory of the Kirchhoff-Love type is accurate.
Sufficient conditions for H-infinity control on the finite time interval
Authors: Panteleev A V , Yakovleva A A
Published: June 2021

The article considers a problem of control of linear non-stationary continuous dynamical systems on a finite time interval. It is assumed that information about the linear output of the controlled system is available instead of the full state vector. The problem of the synthesis of H-infinity regulators is formulated. Based on the ideas of the extension principle, sufficient conditions for H-infinity control are formulated and proved, the best control law for an object and the worst control law for external disturbances with full state feedback are found. Since the exact implementation of the obtained control laws in the absence of complete information about the state is impossible, two approaches to the approximate solution of the problem are proposed. Both approaches are associated with finding an estimate of the state vector and using it in control. The first approach is based on the use of pseudoinverse matrices, which allow finding the estimate based on incoming measurements. The second approach utilizes the idea of using asymptotic observers that ensure that the estimation error tends to zero as well as the asymptotic stability of the closed-loop system. The solution of a model example is given, illustrating the application of the proposed approaches.
Moving object SINS transfer alignment time synchronization parameters estimation
Authors: Kuznetsov I M , Veremeenko K K , Zharkov M V , Pronkin A N
Published: June 2021

The main unmanned aerial vehicles launched from a carrier aircraft onboard navigation system, usually, is a strapdown inertial navigation system. The paper considers the influence of the time synchronization error in the strapdown inertial navigation system transfer alignment on a moving base task. The influence of the time synchronization error, as well as the technique of its estimation, is directly the subject of this study. SINS mathematical models are considered on the basis of error equations, the state vector, including errors of coordinates, linear velocities projections, attitude angular errors of the measuring coordinate system relative to the calculated one, accelerometers and gyro systematic errors components are extended by the angles of misalignment of two systems – unmanned aerial vehicle strapdown inertial navigation system and carrier aircraft navigation system and time delay component. The measurement vector includes the difference of the corresponding output parameters of two systems – carrier aircraft strapdown inertial navigation system or its navigation system and unmanned aerial vehicle strapdown inertial navigation system. A simulation was performed, and state vector estimates were obtained.
Tools for intellectual support of project decisions based on analyzing uncertain factors of a different nature
Authors: Bulygina O , Ivanova O
Published: June 2021

Today, the management of complex innovative projects to create new aircraft is carried out in the conditions of uncertainty, which is due to the lack of “high-quality” (complete, accurate, consistent, etc.) data on their internal and external environment. In this situation, to support the adoption of project decisions, it is advisable to use an approach based on the identification and assessment of NON-factors that have a negative meaning in natural language and deny one of the basic properties of formal systems. The authors propose a procedure for analyzing NON-factors in project risk management, based on the assessment of uncertain factors of internal and external project environment using various methods of data mining (particularly, neural fuzzy classifier, fuzzy pyramidal networks, fuzzy logic methods, fuzzy Kalman filtering algorithms). Using the proposed approach will increase the validity of decisions on the viability of such innovative projects and a set of measures for risk management.
Using pipelined control code generator as a reference system in FPGA’s selection as a hardware platform for fault-tolerance computing system
Authors: Brekhov O , Ratnikov M
Published: June 2021

One of the main features of hash functions is a significant change in the hash with any (even small) changes in the input data. Using their pipelined versions (which outputs the next hash on each clock cycle) allows to create a system that is guaranteed to respond to any failures in the process. Reference systems based on control code generators can be quickly developed and thanks to a wide range of functions, for calculating control codes, can be close to the characteristics of the developed system in terms of area and logical complexity. In this article, we propose using pipelined control code generators as reference systems in the development of fault tolerant computing systems. In this case, before or simultaneously with the development of a computing system, we need to perform a series of experiments with pipelined generators and control codes. Several versions of such reference system have been developed, each of which implements various fault tolerance techniques. The obtained protected reference systems are synthesized into the basis of available FPGAs by various software packages. Next, the results are compared and the most successful (with good results) sets are selected from FPGAs, software, and fault tolerance techniques.
Review of open-source cubesat projects
Authors: Shalashov M , Kiseleva A
Published: June 2021

Open source software and hardware plays a significant role in information technology and consumer electronics today. This paper examines the application of the open source concept to space technologies. The purpose of this review is to identify ways to apply existing license types to CubeSat open-source projects. The analysis of existing CubeSat open-source projects is carried out, the tendencies of this direction development are shown.
Development of the mathematical model for the tilt-rotor aircraft
Authors: Lelkov K S , Ulyanov D V , Surkov D A , Ushakov A N
Published: June 2021

In this paper, main challenges of the urban air mobility concept are discussed and comparison of the different aircraft types, capable of performing vertical take-off and landing for compliance to the urban aerial mobility concept is provided. The mathematical model for the tilt-rotor aircraft is derived by the Newton-Euler method. This model takes into account all the forces and moments applied to the aircraft. Aerodynamic characteristics for the developed aircraft were obtained using virtual aerodynamic blowing method. Simulation results of the tilt-rotor aircraft motion on the various flight stages, including vertical take-off and landing, horizontal flight and transition stages are presented.
Simulation of projects for creation of aircraft products for use in life cycle management systems
Authors: Mustaev I , Semivelitchenko E , Maximova N , Ivanov V , Mustaev T
Published: June 2021

The article describes the elements of modeling projects to create complex technical objects in the framework of the sociophysical approach. It is shown that the proposed approach has an advantage in comparison with the approach focused on assessing the present value of the project. It is noted that the application of the sociophysical approach opens the way to solving the problems of finding reliable interpretable solutions at all stages of the life cycle of an innovative project. A feature of the sociophysical approach associated with the use of diverse economic, technical, technological, and other information are formalized. The terminology used in the sociophysical modeling of projects is given. The concepts of cooperation between the project and the enterprise are formed within the framework of sociophysical modeling. The structure of the sociophysical models of the project is disclosed. The sociophysical definition of the technological structure of the enterprise where an innovation project realizes is given. Results confirming the efficiency of using the accumulated potentials are presented.
Composite panels design based on post-buckling state with combined loading
Authors: Mitrofanov O V , Osman M , Gavriliak V E
Published: June 2021

Buckling is possible for thin composite skins of light aircraft wing high-lift devices loaded above limit level. Aim of this work is to create a method for orthotropic panels minimal thickness definition with possible post-buckling behavior considering residual strength support. Hinge supported composite panels loaded in compression and shear jointly are considered. Method based on analytic solution of non-linear problem and design method by post-buckling state is suggested in the paper. In order to explain peculiarities of above-mentioned method examples of panels design loaded with tangential force supporting strength and stability are shown in this work. It is demonstrated that for panels minimal thickness calculation by strength, stability, and post-buckling behavior conditions corresponding linear, second- and third-degree equations in unknown thicknesses are derived. In order to develop design method by post-buckling state with combined loading analytic solution of non-linear problem using Bubnov-Galerkin method is shown in the paper. Chai criterion including all components of acting forces and stress critical values for residual strength has been used for composite package based on the conditions of combined loading. Variants of developed applied methods of design based on post-buckling state with only tangential force acting and with combined loading by compression and shear flows are shown in this work.
Mathematical methods for optimal synthesis of physical and mechanical structure of composites with required set of properties at extreme conditions
Authors: Gusev E , Bakulin V
Published: June 2021

Variational statements of composite structure with the required set of properties synthesis problems are investigated. The study of the limiting capabilities of composites to achieve required set of properties is necessarily associated with development of effective methods for finding global extremum of corresponding functionals. The article deals with problems of numerical analysis and optimal design of composite structure with required set of properties. Mathematical models describing the propagation of wave processes of various physical nature in layered-inhomogeneous structure of composite are investigated. Problems of optimal design for composite structure with required set of properties are formulated in variational formulation. Based on the theory of multi-valued mappings and methods of continuation by parameter, method for studying limiting capabilities of composites to achieve required set of properties is developed. Developed technique allows effective construction of layered composites with complex characteristics. The application of developed method of optimal synthesis for the study of limiting possibilities in reflection of energy of wave action from layered-inhomogeneous coating in given range of spectrum is considered.
Development of a small-sized electromechanical steering gear unit by simulation modeling
Authors: Norinskaya I , Guskov A , Spirin A
Published: June 2021

In this paper the results of the development of an electromechanical steering gear based on waveform reductor that provides rotary motion of the working surfaces of small-sized aerial munition are presented. Calculations of the design parameters of the components of the steering gear, the formation of the desired dynamic properties of the product are implemented by the method of simulation modeling in the Matlab Simulink environment. The model is fully parametrized. The Simulink-model contains blocks that implement signal conversion in accordance with the physical model of real equipment. The article presents the results of laboratory and flight tests of a prototype of steering gear confirming the success of the adopted circuitry solutions and the adequacy of the developed simulation model. The developed simulation model can be used as universal design tool for electromechanical steering gears.
Modelling of the process of a program compilation according to the training sample data using the collective intelligence of the simplest computers
Authors: Protasov V , Potapova Z
Published: June 2021

The description of the system intended for genetic programming and consisting of a large number of elementary computers is given. Commands and data are placed in a cell consisting of four fields – the first address field, the second address field, the arithmetic field and the result field. This architecture made it possible to place a software binary tree formed by commands and addresses into sequentially located cells of an elementary computer. This technique made it possible to simplify the crossover and mutation operators, as well as the coding of the problem without involving complex programming systems and supercomputers. In the future, it is planned to use table processors tested on complex problems of genetic programming to significantly reduce power consumption in on-board computers of aviation and space technology.
Electrospark alloying of titanium alloy aircraft engine parts
Authors: Koreshkov A , Boitsov A , Siluyanova M , Amui A , Remchukov S
Published: June 2021

The study objective is to improve the performance of titanium alloy parts used in aircraft jet engines with electrospark alloying. The technology can be used for hardening compressor rotary vanes and rod ball joints, protecting compressor blade leading edges from erosion. We studied the alloyed layer formation process and determined the layer structure and composition. The study presents experimental findings of the Ti alloy electrospark alloying as certain substances were introduced into the interelectrode gap. We also assessed the relationship between the electrospark alloying process variables and the alloyed layer surface finish.
Single-photon Mach-Zehnder interferometry for High Schools
Authors: Bondani Maria
Published: June 2021

The superposition states, allowed by quantum theory, are dramatically diverse with respect to classical states and represent the true quantum states. By using a Mach-Zehnder interferometer we experimentally show how a single photon in a polarization superposition state can produce interference. The experimental setup includes a strongly attenuated laser source, polarizing beam splitters, half-waveplates, polarizers and single-photon detectors. The experimental activity has been performed with high-school students and teachers in several different contexts.
Study on dynamic water environmental capacity of the river network in Wenhuang plain based on the hydrodynamic and water quality coupling model
Authors: Ma H B , Tian C C , Huang D J , Wang L T
Published: June 2021

The calculation of water environment capacity (WEC) is the basis of pollution control, and it is of great significance to the formulation of water environment quality management scheme meanwhile. Due to the precipitation varies with seasons, WEC has an obvious temporal dynamic feature, that is ignored in the traditional method under a single fixed hydrological condition design hydrological condition. Thus, on the basis of the hydrodynamic and water quality coupling model, the trial-and-error method was adopted to investigate the traditional and dynamic (by month) WEC of NH3-N of Wenhuang plain of Zhejiang Province in this paper. The result shows that WEC had a relatively large fluctuation during the year, of which the value was distinctly lower in dry season and the peak was present in June. It can be concluded that the dynamic algorithm was more in line with the actual circumstances compared with the traditional method.