bluuebunny/crossref_metadata_2025 huggingface dataset:
DSC, FTIR Studies of Borophosphate Glasses doped with SrO, Li2O
Authors: Thipperudra Anand , Manjunatha S , Pushpalatha H L , Prashanth Kumar M
Published: June 2021

A series of five samples of Borophosphate glasses doped with SrO and Li2O within the composition of 20(B2O3) + 30(P2O5) + x (SrO) + (50-x) (Li2O) where x = 10, 20, 30, 40 & 50. The Glass Samples were prepared by the melt quenching technique, and the samples were annealed to remove if any thermal strains present. Glasses were characterized by DSC studies in the temperature ranges from 423-673K to determine the glass transition temperature (Tg). Here Tg increases linearly with SrO mole fractions, the FTIR study shows the existence of different structural and functional group of B2O3, P2O5 such as BPO4, BO3 and BO4 units in the network. Borophosphate glasses containing SrO and Li2O, which exhibits different IR bands, related to SrO structural units.
On Indirect Excitation of Lateral Vibrations of the Table of the Electrodynamic Stand Suspended on Viscoelastic Shock Absorbers
Authors: Safarov I.I. , Teshaev M.Kh. , Nuriddinov B.Z. , Ablokulov Sh.Z. , Ruzimov A.
Published: June 2021

Modern machines and aerospace facilities are equipped with rather complex, multi-link high-level vibration protection systems. Therefore, it is of interest to carry out work on the formation of dynamic models of vibration-protective properties of the apparatus, taking into account the properties of their real design features. The plane-parallel motion of a viscoelastic suspended rigid body with an axis of symmetry and imitating the motion of the table of an electrodynamic stand is considered. In the calculated dynamic scheme, the action of the suspension membranes and the hanging shock absorber is represented as the action of some linear springs. It is assumed that a periodic perturbing force (the action of a pulsating magnetic field) directed vertically is applied at the body’s center of gravity. Nonlinear integro-differential equations of motion are compiled, in expansions of trigonometric functions and power series, only small second2 nd order are kept. The method of averaging is used to reduce to normal coordinates. The conditions for indirect excitation of axial lateral vibrations (torsional vibrations about the horizontal axis) under the stability of the parametric resonance of the vertical are obtained. Formulas providing the suspendet object are obtained.
Effect on Doping of EDTA on Structural, Optical and Mechanical Properties of KDP Crystal
Authors: Dholariya A M , Raval K G
Published: June 2021

Single crystal of Potassium Dihydrogen Orthophosphate (KDP, KH2PO4) pure and doped with EDTA (Ethylenediaminetetraacetic acid, [CH2N (CH2CO2H)2]2) have been successfully grown by slow evaporation method at room temperature with deionized water as a solvent with a aim to improve the properties of KDP crystal. The concentration of EDTA was 0.1mol%. The Energy Dispersive X-ray Analysis (EDAX) confirms the presence of EDTA in grown crystals. A tetragonal structure of crystals was confirmed and the value of lattice parameter was calculated by X–Ray diffraction (XRD) analysis. Optical energy band gap was determined by UV-VIS Spectroscopy. Raman Spectroscopy studies structural mode of bond in pure and EDTA doped KDP crystal. Microhardness of the crystals was measured with different dwell time and different load using Vicker microhardness tester.
A Comparison Study on Shape Parameter Selection in Pattern Recognition by Radial Basis Function Neural Networks
Authors: Tavaen S , Kaennakham S
Published: June 2021

This study investigates three choices of shape parameter selection when the so-called Radial Basis Function (RBF) is used. Under the problem of pattern recognition via RBF-Neural Network using RC-algorithm, three RBFs are focussed on; Gaussian (GA), Multiquadric (MQ), and Compactly-Supported (CS1). Two pattern recognition cases are tested and the best choice of shape parameter is validated using Model-Selection Criteria (MSC).
Propagation of Natural Waves on a Multilayer Viscoelastic Cylindrical Body Containing the Surface of a Weakened Mechanical Contact
Authors: Ishmamatov M R , Avezov A X , Ruziyev T R , Boltayev Z I , Kulmuratov N R
Published: June 2021

In this work, the study of the problems associated with the propagation of natural waves in multilayer viscoelastic cylindrical bodies with a weakened mechanical contact is discussed. A detailed analysis of well-known works devoted to this problem is given. A mathematical formulation, a technique, and an algorithm for studying the damping properties of natural waves in multilayered cylindrical mechanical systems with a weakened mechanical contact are developed. The solution of the considered problem was obtained by the method of separating the variables based on the theory of potential functions (special functions).The complex roots (phase velocities) of the dispersion transcendental equation for given wavenumbers are determined numerically by the Muller method. The phase and group velocities of a structurally heterogeneous mechanical system at various geometric and physical-mechanical parameters for the elements of the mechanical system are investigated. It was established that the real parts of the wave velocity will increase by only a few percent, and the imaginary parts for structurally heterogeneous mechanical systems radically change; the phase velocities (real parts of the complex velocity) of natural waves with an increasing wave numbers around the cylinder circumference of structurally heterogeneous mechanical systems first decrease and then begin to increase. A mechanical effect was discovered for structurally heterogeneous mechanical systems, which provides damping for the waves of the mechanical system as a whole.
Maximizing Common Data Rate of collection Tree in Energy-Harvesting Wireless Sensor Networks
Authors: Li-yong Yuan
Published: June 2021

Energy-harvesting wireless sensor network (EH-WSN) has the capability of capturing energy from environment and providing perpetual data services. In many applications of EH-WSN such as environmental protection, building monitoring, industrial internet of things, nodes are required to report sensed data to the sink with high common data rate to improve monitoring accuracy. In order to improve the common data rate of collection tree-based network, this paper studies collection tree construction for maximizing common data rate. We propose a collection tree construction scheme named hybridMCDRT which consists of a heuristic construction algorithm, an iterative optimization algorithm and “detour problem” elimination algorithm. The simulation results show that the proposed scheme can obtain higher common data rate than the existing methods.
Discovering Internet of Things (IoT) Applications for Health Monitoring During the Outbreak of Infectious Disease
Authors: Wei Yingjue , Gan Peiping , Chen Liangguang , Huang Guangyuan , Meng Dan , Huang Qiuju , Jiang Tao
Published: June 2021

This research aims to discover the Internet of Things (IoT) technologies and applications available for health monitoring during infectious disease outbreaks. Currently studies about IoT and health monitoring are reviewed to identify applications. Then we randomly selected 100 valuable comments from top five online shops’ using reports of Internet of things devices as the basis of the data analysis. Technology acceptance model (TAM) and familiarity and trust model1 (FTM1) were further conducted on these using reports to value why IoT technologies and applications is ‘perceived usefulness’ and ‘perceived ease of use’ used for health management. We found IoT applications are ready widely used in health management fields. There were significant positive advantages for ease of use. IoT applications were significant positive advantages for infectious disease symptom monitoring.
Research on Application of wireless Communication System in Middleware of Internet of Things
Authors: Li Yijie , xu Liqun
Published: June 2021

With the popularization of mobile communication technology and Internet of things, wireless data transmission operation occupies an important position. Massive data generated by the Internet of things system is applied to the Internet of things system by wireless communication network and wireless resource management. Wireless network communication technology is the use of radio waves for data transmission, is a new type of communication information system, for the future development of communication system has established the direction. The wireless communication system is introduced into the middleware of the Internet of things system to improve the security and reliability of the Internet of things and ensure the timely and effective dissemination of information and data in the Internet of things system.
Sensor deviation anomaly trend prediction based on phase space reconstruction and Support Vector Regression
Authors: Renjie Han , Dong Song , Yujie Li
Published: June 2021

Ship combat systems are developing in the direction of integration and intelligence, and the integration also brings problems such as difficulty in predicting abnormal sensor trends in combat systems. The failure characteristics of sensors in combat systems are highly secretive, and it is difficult to detect and deal with system equipment failures by relying on empirical qualitative or single-indicator testing methods. In order to safeguard the ship’s combat capability and make reasonable maintenance decisions, it is important to study more accurate prediction methods. This article proposes a method for predicting sensor deviation anomaly trends based on phase space reconstruction and Support Vector Regression(SVR), taking sensors in naval combat systems as typical research objects. Firstly, a phase space reconstruction is performed on the sensor deviation time series data to increase the accuracy of subsequent prediction; then a SVR prediction model is built, and the model is trained and optimised using the reconstructed data; finally, the constructed prediction model is compared with the regular SVR model and BP neural network model to verify that the constructed model has higher prediction accuracy.
A novel correction weighted localization algorithm for quadrilateral ranging
Authors: Zhang Yaling , Zhao Lishuai , Zhou Ran , Yuan Jiaozhi , Zhang Lijun , Yang Bo
Published: June 2021

Localization technologies based on received signal strength indication (RSSI) have been widely used in indoor localization, however, RSSI is disturbed by transmitted power of equipment, infinite interference source and so on. To overcome this drawback, this paper proposes a novel correction weighted localization algorithm for quadrilateral ranging. The algorithm uses Gaussian-moving average filtering (GMAF) to process the data and regularized least square estimation to estimate the parameters of the log-normal shadowing model. Then, a weighted correction factor is introduced to locate the target node. Finally, the simulation and experimental results verify the accuracy and robustness of the proposed algorithm.
Structural crack localization and identification based on FBG
Authors: Chen Yong , Chen Yawu , Jiang Tao
Published: June 2021

The current structural crack detection still suffers from the problems of single detection target, inability to achieve true acoustic emission crack signal separation, and poor portability of the sensing system. To address this phenomenon, in this paper, based on the use of fast blind source signal separation, combined with the designed structural crack sensing detection model, we will first coarsely localize the crack location area, and within this area, we will use the designed structural multi-crack parameter identification algorithm to achieve the multi-crack location identification purpose. The experimental results show that the proposed method achieves an average localization accuracy of 1.95 cm and a localization time delay of about 25 ms. It provides a feasible method for structural crack detection.
Characteristics and Analysis of fiber Fabry-Perot Force Sensor
Authors: Song Zengyu , Wang Ning , Zhu Yong , Wang Jiang
Published: June 2021

In this paper, a new optical fiber Fabry-Perot force sensor structure was designed based on the extrinsic optical fiber Fabry-Perot sensor. The sensor had the advantages of small size, high temperature and high pressure resistance, and had good resistance to strong electromagnetic interference. It can measure the friction force on the heat transfer pipe of steam generator in the harsh environment. The transmission characteristics of the sensor were analysed, and the performance of the sensor was simulated. Theoretically, the sensitivity of the sensor can reach 2.591 nm/N, and the minimum resolution can reach 11.309 N.
Density of condensates of two-component Bose-Einstein condensates restricted between two planar walls
Authors: Thu Nguyen Van , Song Pham The , Le Nguyen Thi
Published: June 2021

The density of condensates of a binary mixture of Bose gases restricted by two parallel planar walls is investigated within the framework of Cornwal-Jackiw-Tomboulis effective action approach in improved Hartree-Fock approximation. It results that the density of condensates strongly depend not only on the distance between two walls but also on the interspecies interaction strength and they are equal their expectation values of the field operators after adding a term associated with the quantum fluctuations.
Thermodynamic properties of Cu3Au alloy
Authors: Tan Pham Duy
Published: June 2021

Based on the general expression of the Helmholtz free energy of alloys with Ll2 structure obtained in previous works, we calculate the equations of the long-range order (LRO) parameter, and order-disorder transition (ODT) temperature in the Cu3Au alloy, and obtained thermodynamic quantities of Cu3Au alloy as simple functions of temperature and LRO-parameter, at pressures P = 0. Numerical results of the linear thermal expansion coefficient, isochoric and isobaric heat capacities, isothermal and adiabatic bulk modulus, are in good agreement with experiments.
The influence of confined acoustic phonon on the quantum Peltier effect in doped semiconductor superlattice in the presence of electromagnetic wave
Authors: Hung Le Thai , Quynh Nguyen Thi Lam , Anh Nguyen Thi Nguyet , Bau Nguyen Quang
Published: June 2021

Based on the kinetic equation method, the quantum Peltier effect has been theoretically studied under the influence of confined acoustic phonon in doped semiconductor superlattice in the presence of the electromagnetic wave (laser radiation). There were complicated dependences of the analytical expression of the Peltier coefficient (PC) on quantities such as doped concentration of the superlattice, amplitude of the laser radiation, the cyclotron frequency of electrons and temperature of the system. In detailed consideration, the quantum number m was changed in order to characterize the influence of confined acoustic phonon. When setting the m to zero, we obtained the results that corresponded to the case of unconfined phonon. The theoretical results have been numerically evaluated and discussed for the GaAs:Si/GaAS:Be doped semiconductor superlattice (DSS). We found the oscillation of the PC according to enhancement of cyclotron frequency of electrons. Moreover, position of resonant peaks has shifted under the influence of phonon confinement. In the case of low doped concentration (n D), the PC decreased in non-linear way; then it reached a negative constant in high n D value. The non-linear change of the PC also has been detected when investigating its dependence on the laser amplitude. All numerical results have shown that the magnitude of the PC decreased due to the increase of phonon confinement effect. In short, the confinement of acoustic phonon caused the change of the quantum Peltier effect in DSS of GaAs:Si/GaAS:Be in quantitatively as well as qualitatively.
Temperature dependence of the correlation function in EXAFS spectra: Application to Cu-Ag alloys
Authors: Duc N B , Tho V Q , Hiep T P
Published: June 2021

Correlation ratios between the mean square displacement (MSD), mean square relative displacement (MSRD), and correlated displacement function were studied in extended X-ray absorption fine structure spectra (EXAFS). The expressions of MSD, MSRD, and correlation function were determined using Debye models. Hardy problems due to many-particles effects were considered and replaced by a calculation based on the effective anharmonic potential, including the interaction of absorbing and scattering atoms with their nearest neighbours atoms. Based on the Debye-Waller factor, the difference between MSRD and MRD was analyzed, and their ratios have calculated. The methods were applied to fcc crystals and their alloys. Numerical results for Cu, Ag crystals and CuAg50 alloys agreed with experimental values and other studies.
Phase diagram of the half-filled Anderson-Falicov-Kimball model with Coulomb disorder
Authors: Yen Nguyen Thi Hai , Tuan Hoang Anh
Published: June 2021

We derive the electronic phase diagram of the half-filled Anderson - Falicov-Kimball model with Gaussian distribution for impurities and box distribution for Coulomb disorder via dynamical mean field theory combined with typical medium theory. We show that the metal and the Mott insulator regions shrink as the strength of Coulomb disorder increases. The influence of the difference distributions (the box and the Gaussian) for impurities is also considered.
Construction of dimeric hTSPO protein model using homology modeling and molecular dynamics
Authors: Lai Hien T T , Nguyen Toan T
Published: June 2021

A model for the dimeric form of the human TSPO (hTSPO) protein is constructed homologically using the RsTSPO dimer template. Then, Molecular dynamics simulation of 1μs is carried out on the model to investigate its stability as well as to study its various physicochemical properties. Our model shows good stability, with various important conserved residues involving in monomer–monomer interactions, in good agreements with available experimental data. Several functioning motifs are well demonstrated. This model hence can serve as a good basis for further study of this system as well as for discoveries of candidate radioligands targeting TSPO protein as a biotracer for medical imaging of brain inflamation.
The connection between ADT and evolutionary methods in product development
Authors: Soltész László , Nagy Szilárd
Published: June 2021

This paper presents similarities and connection points of Autogenetic Design Theory (ADT) and evolutionary methods. During a short historical overview, ADT is positioned in a timeline. The authors show where common issue points between the two approaches are. Then demonstrate how to use these methods, to avoid a long progress of iteration and tests of several versions and directions. Via an example study of truck floor design, benefits of evolutionary methods are highlighted and made understandable for readers.
Project Management Success Factors
Authors: Venczel T B , Berényi L , Hriczó K
Published: June 2021

There is a high need – especially in industrial organizations – to launch successful products and services. Therefore, it is crucial to understand what are the key factors in project success. The motivation of the research is to examine, if there is a model that can be applied to predict future project success; preferably in the automotive engineering and manufacturing environment. The paper aims to study project success literature and understand the differences and similarities between project success and project management success. Also, highlight the importance of the application of convenient models, to define success factors and link them with success criteria. Without a proper definition of success, success factors, and success criteria, the right success model cannot be chosen; therefore, the risk for an unsuccessful launch is higher. Applying a proper success model forecasts future project success. The first section of the paper introduces project success management, afterward literature review given differentiating project success, project management success, and success models. The overview highlights the importance of proper success factors and criteria definitions supported by success factor model application to increase the likelihood of successful project implementation.
Review of Mobility Scenarios Generators for Vehicular Ad-Hoc Networks Simulators
Authors: Boucetta Sara Imene , Guichi Youcef , Johanyák Zsolt Csaba
Published: June 2021

The most used technology for ITS (Intelligent Transportation System) is VANET (Vehicular Ad-hoc NETworks) which is a subclass of MANET (Mobile Ad-hoc NETworks).VANET enables wireless communication between vehicles as well as RSU (Road Side Units), by using the standard 802.11p channels bandwidth to transmit all sort of information to each vehicle, within the range of the communication, providing passengers with plethora of safety, comfort and traffic monitoring applications. These networks are characterized by the predictable motion nature of vehicles which allows to predict the future locations of the nodes. They are also known for their varying topology through time, due to the changing number of nodes and the lane-constrained mobility patterns and their reduced power consumption requirements. However, the implementation, deployment and testing of VANET implies significant cost and requires a huge experimental platform. Therefore, computer simulation seems to be one of the best alternatives to test VANET communication protocols, before their deployment. However, the correct simulation of these networks requires to have access to a large number of heterogeneous mobility and traffic scenarios. Several research works try to solve these issues by creating mobility models that tend to accurately generate trace-files, that reflect the true nature of road traffic motion. This paper reviews these existing solutions and the need to develop them into intelligent tools, capable of faithfully reflecting human driving behavior in computer simulation scenarios designed to accurately test VANETs.
Industry 4.0 and Modern Maintenance in Today’s Hungarian Vehicle Industry
Authors: Juhász L , Pokorádi L
Published: June 2021

This paper presents survey results conducted in the domestic automotive industry. In this context, current trends in the maintenance sector were examined. In particular, the effects of smart manufacturing and modern devices on maintenance were addressed. The authors analysed the given responses and looked for correlations between them.
Inlet shape optimization of pneumobile engine pneumatic cylinder using CFD analysis
Authors: Černák M. , Michalec M. , Valena M. , Ranuša M.
Published: June 2021

The aim of this study is to minimize minor losses in cap-end ports of a pneumatic cylinder used in pneumobil vehicle engine. Six geometry arrangements of intake ports, including the currently used version, were designed assuming conventional machining technology. Boundary conditions for the analysis were acquired from experimental measurement. The air flow was analyzed by 3D stationary CFD analysis in ANSYS Fluent for all designs. Pressure drop was used as the evaluation criteria. Two best configurations according to the obtained results were optimized using ANSYS Fluent Adjoint Solver. The pressure drop was reduced by 81.1% using this method. The obtained results will be used for design of solid geometry customized for production by lost wax casting process.
The potential of vehicle cooling systems
Authors: Bencs P , Alktranee M
Published: June 2021

Vehicle engine cooling systems have several functions. Excess heat removal from the engine helps to rapidly cool it, quickly reach operating temperature, maintain a constant engine operating temperature, and provide heat to the vehicle’s passenger compartment. Developments in the automotive industry, such as hybrid and electric vehicles, now also involve the temperature management of battery packs. Currently, the coolant used in cooling systems is water or an equivalent substance. Water as a coolant has low thermal conductivity. Therefore, researchers are trying to use nano-liquid as a coolant in the cooling system. Better results are expected by use of this alternative. Nano-liquids contain metal particles that enhance thermal transfer properties, so current and future cooling systems could operate more efficiently. Adding phase change materials to the cooling and air handling systems will result in better efficiency in future vehicles. In the case of hybrid and electric vehicles, the addition of thermoelectric generators to cooling and exhaust systems increase efficiency. Present developments help increase a vehicles’ usability and the possibility of achieving greater efficiency.
AVL Boost: a powerful tool for research and education
Authors: Bellér G , Árpád I , Kiss J T , Kocsis D
Published: June 2021

AVL Boost is a fully integrated simulation software in the field of internal combustion engines. At the University of Debrecen, it has been roughly a year since the launch of the Partnership Program with AVL Advanced Simulation Technologies. Although 2020 made us face unusual and unexpected challenges, the use of Boost has begun both in research projects and in engineering courses. The software provides a wide range of applications in engine performance, tailpipe emissions and acoustics. It is inherently appropriate only for internal combustion engines including both spark-ignition and compression-ignition engines. However, with a link to other AVL software packages (e.g. Cruise or Fire), hybrid vehicles can be studied too. Boost enables the user to perform a solely computational approach, as well as the comparison of experimental findings with simulation results. The software offers a high level of flexibility of the fuel type and fuel composition, including the possibility to use both conventional and alternative fuels. Our paper provides an overview of the software including a general introduction, a review of selected publications from recent years and a discussion of the application of Boost, in engineering courses and student projects.
Comparative carbon footprint analysis of residents of wooden and non-wooden houses in Finland
Authors: Ottelin Juudit , Amiri Ali , Steubing Bernhard , Junnila Seppo
Published: June 2021

Sustainable forest management and harvested wood products together can create a growing carbon sink by storing carbon in long-lived products. The role of wood products in climate change mitigation has been studied from several perspectives, but not yet from a consumer’s view. In this study, we examine the impact of wooden housing on consumer carbon footprints in Finland. We use the 2016 Finnish Household Budget Survey and Exiobase 2015, a global multi-regional input-output model. The sample size is 3700 households, of which 45% live in a wooden house. We find that residents of wooden houses have a 12(±3)% (950 kg CO2-eq/year) lower carbon footprint on average than residents of non-wooden houses, when income, household type, education of the main income provider, age of the house, owner-occupancy and urban zone are controlled in regression analysis. This is not fully explained by the impact of the construction material, which suggests that the residents of wooden houses may have some features in their lifestyles that lower their carbon footprints further. In addition, we find that an investment in a new wooden house in an urban area has a strong reducing impact on a consumer’s carbon footprint, while investments in other types of housing have a weaker or no reducing impact. Our findings support wooden housing as a meaningful sustainable consumption choice.
Quantifying the indirect effects of urbanization on urban vegetation carbon uptake in the megacity of Shanghai, China
Authors: Wei Shuyun , Chen Qiuji , Wu Wanben , Ma Jun
Published: June 2021

Urbanization causes the expansion of urban land and changes to urban environments, both of which have significant impacts on the carbon uptake of urban vegetation. Although previous studies have proposed that the impact of the changes in the environmental conditions of vegetation carbon uptake by urban expansion are generally indirect, the processes of this impact are still unclear. In this study, we quantified the indirect effects of urbanization on urban vegetation carbon uptake for unchanged vegetation areas. We extracted unchanged vegetation areas based on multisource remote sensing data from the Google Earth Engine cloud computing platform. The influence of urbanization on vegetation carbon uptake and urban environmental factors in 2004, 2010, and 2016 along with the urban–rural gradient was calculated. In addition, we investigated the relative contribution of urban environmental factors to vegetation carbon uptake to study the relationship between them using a boosted regression tree method. The results showed that urbanization promoted vegetation carbon uptake, which varied with different years in Shanghai. Besides, the promoting effect of urbanization on the carbon uptake of vegetation was mainly due to the increase in temperature and the fragmentation of vegetation landscape patterns in Shanghai. The changes of soil moisture and radiation had little effect on the vegetation carbon uptake. Among the influencing factors, the relative contribution of the vegetation landscape pattern to vegetation carbon uptake was about 85%. Considering the crucial role of landscape patterns in the carbon uptake of vegetation, urban managers should consider reducing the negative influence of urbanization on vegetation through landscape design, which will further promote the sustainable development of urban ecology.
Application of Dynamic Control Theory in Intelligent Control System for Asphalt Pavement Construction
Authors: Zhang Lili , Huang Jianping , Wang Shuai
Published: June 2021

The intelligent control system for asphalt pavement construction can achieve the data collection, transmission, analysis and early warning during the entire construction process, including mixing, transporting, paving and rolling, by installing data collecting equipment and building the remote monitoring platform. It can effectively improve the construction quality control level. However, the quality control method adopted by the system still has some shortcomings and can’t meet the requirements of dynamic quality control. Therefore, this paper infuses dynamic control theory to improve the existing system quality control method. And, the practicability and effectiveness of the proposed method are verified through case analysis in this paper.
Construction and Application of Virtual Experiment Teaching System for Integrated Mapping of Unmanned Ship
Authors: He Yuanrong , Sun Ruping , Wang Yuli , Nie Dewei , Wang Weisen
Published: June 2021

At present, China’s water pollution situation is still very serious, and water pollution prevention is an important part of ecological environment protection, and water quality monitoring and pollution traceability are the basis of prevention and control work. Unmanned ship system uses GNSS intelligent navigation and positioning technology, automatic obstacle avoidance technology, real-time communication technology, sonar sounding technology and manual control technology, etc., by collecting underwater terrain, water quality information and underground pipe detection, it can complete water quality detection unmanned, intelligent and efficient. In this paper, the system architecture and measurement principle of unmanned equipment are comprehensively expounded, and based on WebGL and virtual simulation technology, an open unmanned equipment virtual simulation training system is constructed, which can directly carry out assembly training of unmanned aircraft and unmanned ship and flight control training of unmanned aircraft on the Web side. Finally, the feasibility and development prospect of unmanned equipment in sewage monitoring are discussed with an application example.
A Method of Identifying the Critical Source Areas for Phosphorus Loss in Geological Phosphorus-rich Watersheds
Authors: Wang Chensheng , Xue Qianqian , Chen Honghan
Published: June 2021

The principal cause of eutrophication in some freshwater systems is diffuse phosphorus (P) loss. The identification of critical source areas (CSAs) is identified to be the most effective way to minimize the difficulty of nonpoint source (NPS) P pollution management in watersheds. How to efficaciously identify CSAs for phosphorus loss in geological phosphorus-rich (GPR) watersheds is still a challenging hassle. An assessment approach primarily based on QGIS was applied to assess the risk of P loss and identified CSAs for a case study in the Huangbai River watershed of south China, which is a typical geological P-rich (GPR) watershed. In the modified P ranking scheme, total soil P (TP) content in various land use types was used as a source factor; the topographic index (TI) and distance-to-streams were considered as transport factors. P index calculation results showed that 92.2% of the watershed was low risk area, while 7.8% for medium and high risk of P loss. Meanwhile, higher risk areas were associated with the shorter distances from the stream, higher TI, and higher soil P content. Also, CSAs are normally located in phosphate mining sites and concentrated arable land in the karst mountainous areas. The introduction of a simplified P index scheme provides a convenient and practical tool to target CSAs for P loss from GPR areas in data-poor watersheds, thus assisting decision makers to implement remediation actions as to reduce P loss to sensitive waterbodies.
Optimal Configuration Method for EV Charging Station in Distribution Network Considering User Adjustment under V2G mode
Authors: Huang Minfa , Xiang Baolin , Peng Juanjuan , Zhang Lu
Published: June 2021

The existing charging piles planning method of distribution network does not consider the influence of user participation in regulation. Hence, an optimal planning method of electric vehicle charging piles in V2G mode is proposed, considering users’ influence of regulation. An EV charging pile planning model is established to minimize the investment and operation cost of distribution network and charging station, and the genetic algorithm with elitist retention strategy is used to solve the model. The examples show the effectiveness of the proposed method.
Analysis of temperature threshold in flight test
Authors: Zhang Ying , Wang Bin , Liu Xinyu , Ni Ping , Yan Wenhui
Published: June 2021

The annual, seasonal, monthly and daily distribution characteristics, as well as the occurrence and duration of air temperature at Yan Liang Airport were statistical analysis by Matlab software using surface meteorological observation air temperature data from May 2014 to May 2019. It is discussed that the average temperature threshold distribution ranges from 10-25°C in spring, 25-35°C in summer, 15-25°C in autumn and 0-15°C in winter. It showed a good negative correlation with the temperature and relative humidity and it passed the significance test. The daily difference of temperature is positively correlated with the cloud amount. When the total cloud cover is 8-10 amounts, the daily difference of temperature is about 4°C. When the total cloud cover is less than 7 amounts, the daily difference of temperature is 9-10°C. When the total cloud cover is 0-3 amounts, the daily difference of temperature is 9-10°C. Statistics founds that the lowest temperature of Yan Liang Airport in the past 5 years was -13.2 °C, and the highest temperature was 41.8 °C. The minimum temperature occurred in January and the maximum temperature occurred in July. The daily minimum temperature occurred from 05:00 to 07:00 and the daily maximum temperature occurred from 15:00 to 16:00. The corresponding conclusions can provide a scientific basis for the decision of the “window” for a certain subject of flight test. Improve the utilization of meteorological resources and the efficiency that also ensure the progress of the test flight.
Preparation and properties of polystyrene composites modified by macromolecule flame retardant DOPO-HQ
Authors: Chen Qi , Xu Wei , Zhang Yingqiang
Published: June 2021

A macromolecular flame retardant was firstly the group reaction of DOPO-HQ. The modified polystyrene ADOPO-HQ-co-PS was prepared by copolymerization of macromolecular flame retardant and styrene. Its chemical structure was analyzed by Fourier transform infrared (FT-IR). PS composite was prepared by adding it to the experimental formula, and the cone-shaped calorimetry experiment was carried out on the material. The results show that it has a better flame retardant performance than DOPO-HQ. The smoke generation rate is very small, the highest is 0.2m2/s, the CO production is very small, the highest is 0.007g/s, and the mass loss is the highest is 0.14g/s, which shows that the material is more environmentally friendly and stable during combustion.
Gasification Characteristics of Lignite in a Fluidized Bed Gasifier
Authors: Li Xuefeng , Yan Zhenhua , Zhang Qingping , Gao Bo , Chen Hao , Luo Hairong
Published: June 2021

Steam gasification experiment of lignite was carried out in a fluidized-bed gasifier, Effects of bed temperature, steam flow rate and particle size on the gasification behaviors were explored. Gasification behaviors of lignite with/without minerals were compared. When the bed temperature increased, the carbon conversion and gasification efficiency increased, H2 and CO Content increased, CO2 content decreased, and CH4 content kept essentially unchanged. When steam flow increased, the carbon conversion, gas yield and gasification efficiency increased, the content of H2, CO and CO2 in the syngas increased while the CH4 content decreased. In this experiment, compared to the bed temperature and the steam flow, particle size showed only slightly influence on the gasification process. After removing the minerals, weight loss of lignite sample was almost same as the raw lignite, but the pyrolysis rate of the lignite with no minerals accelerated. In the experiment, although the carbon conversion kept no change, the content of H2 and CO2 decreased, CO content increased and CH4 content fallen slightly. From the above, the inherent minerals in the lignite showed a positive influence on the gasification process, which improved the composition of the syngas.
Analysis and Evaluation of Power Grid Loss Reduction from the Perspective of Operation Inspection Based on Risk Theory
Authors: Tao He , Wanli Zhai , Yihuan Feng
Published: June 2021

The use of electric energy has become an indispensable and important part in people’s daily life and production, but there is a certain line loss rate in the process of electric energy transmission. Line loss is the power consumption of transmission lines and equipment in power grid, which is an important skillful index to measure the power loss level of power supply enterprises, and also reflects the power system design, operation, management and economic benefit level of enterprises. Line loss is an important skillful index to measure the power loss level of power supply enterprises, and it is also the embodiment of power system design, operation, management and economic benefit level of enterprises. At present, the scale and scope of power grid construction are constantly expanding, which makes the loss of power and energy increase, and affects the economic benefits of distribution network operation. Based on risk theory, this paper analyzes and evaluates the existence and composition of power loss in the process of power transmission and theft, and puts forward effective measures to reduce power loss in the operation and inspection, so as to more effectively improve the utilization rate of power and economic benefits.
Research and application of profile control and water shutoff technology in fractured sandstone reservoir based on system analysis method
Authors: Pei Guohui
Published: June 2021

Huoshaoshan Oilfield is a sandstone reservoir with severe heterogeneity. After years of enhanced water flooding, the reservoir conditions have changed greatly. Based on the research results of fine reservoir description, the key to successful industrial application of large-scale water shutoff and profile control is to select suitable water shutoff and profile control agents and improve injection technology and evaluation technology. This technology has become a leading technology for improving water flooding recovery in the development of extra-high water cut stage in Huoshaoshan Oilfield, with remarkable economic benefits. In this paper, the main factors affecting the performance of pre-gel system and the flow experiment used to test its performance index are described by systematic analysis method, and the construction effect of well group H1194 is briefly introduced.
Study on the Mechanism of the Influence of Soil Water Content on Cold Resistance of Thermophilic Crops Based on Principal Component Analysis
Authors: Chen Xuehong
Published: June 2021

Soil water content is one of the external factors of plant life, and the cold tolerance of plants is often transferred by this factor. The purpose of this paper is to study the mechanism of soil moisture content affecting the cold resistance of thermophilic crops based on principal component analysis. This paper uses MODIS1B data to obtain the day and night surface temperature difference and albedo parameters; combined with the soil moisture data measured by meteorological stations during the same period, the thermal inertia method is used to establish an empirical model of thermal inertia-soil water content. In addition, the mechanism of the influence of soil water content on the cold resistance of temperature-loving crop rubber and citrus during the low temperature period is discussed, which provides a basis for winter irrigation and antifreeze. The experimental results of this paper show that the vegetation index has a greater impact on the model, so the thermal inertia method has a higher accuracy in monitoring bare soil moisture content. Among them, when the temperature-loving crop rubber soil moisture content is 30%, the cold resistance mechanism reaches the maximum Good, and when the citrus soil water content reaches 22%, its cold resistance mechanism is the best.
Domestic Waste Management in Chengdu from the Perspective of Environmental Governance
Authors: Zhan Ti , Liu Xinjie
Published: June 2021

Classification, recovery and disposal of domestic garbage at source has become an international popular garbage disposal method. Domestic waste classification management has become an important part of urban environmental governance, and improving domestic waste classification management is also an important prerequisite for building a green ecological city. Based on the investigation of domestic waste classification management in Chengdu in recent years, this paper recognizes the understanding and practice of domestic waste classification in Chengdu residents. Therefore, it is known that there are some problems in Chengdu’s domestic waste classification management, such as limited coverage, unclear classification standards, disunity of classification collection containers, insufficient publicity and guidance, and weak awareness of domestic waste classification among citizens. According to the existing problems in the management of domestic waste classification in Chengdu, some measures are put forward, such as perfecting the system design, clarifying the standard of waste classification, strengthening publicity and improving the enthusiasm and initiative of people to participate in waste classification.
HER2-Low Breast Cancers
Authors: Zhang Huina , Katerji Hani , Turner Bradley M , Hicks David G
Published: May 2021

Objectives

Recent clinical trials have demonstrated significant clinical benefits from novel therapeutic compounds in breast cancer patient with human epidermal growth factor receptor 2 (HER2) immunohistochemical (IHC) score of 1+ or 2+ and negative in situ hybridization (ISH) result. A new concept of “HER2-low” breast cancer has been proposed and applied in the recent and ongoing clinical trials. In this article, we review the literature on the topic of HER2-low breast cancer.

Methods

A literature search in PubMed was performed using key words related to HER2-low breast cancer. Major relevant studies that were presented in international breast cancer conferences were also included.

Results

HER2-low breast cancer is currently defined as breast cancer with HER2 IHC score of 1+ or 2+ and negative ISH result. It likely represents a group of tumors with significant biological heterogeneity. Reports of clinical activity using the next generation of HER2-targeting antibody-drug conjugates in HER2-low breast cancers suggest that some strategies of targeting HER2 might be effective in this patient population while raising considerable concerns over limitations in our current testing methodologies and our ability to accurately identify such patients.

Conclusions

The promising efficacy of novel HER2-targeted therapy in advanced HER2-low breast cancers has raised the possibility for changing the clinical interpretation of HER2 status in breast cancer to include a HER2-low category; however, the definition of HER2-low breast cancer, the corresponding reliable and accurate quantitative HER2 testing methodology, and the biology of HER2-low breast cancer remain poorly defined.
Assortativity and Bias in Epidemiologic Studies of Contagious Outcomes: A Simulated Example in the Context of Vaccination
Authors: Zivich Paul N , Volfovsky Alexander , Moody James , Aiello Allison E
Published: May 2021

Assortativity is the tendency of individuals connected in a network to share traits and behaviors. Through simulations, we demonstrated the potential for bias resulting from assortativity by vaccination, where vaccinated individuals are more likely to be connected with other vaccinated individuals. We simulated outbreaks of a hypothetical infectious disease and vaccine in a randomly generated network and a contact network of university students living on campus. We varied protection of the vaccine to the individual, transmission potential of vaccinated-but-infected individuals, and assortativity by vaccination. We compared a traditional approach, which ignores the structural features of a network, with simple approaches which summarized information from the network. The traditional approach resulted in biased estimates of the unit-treatment effect when there was assortativity by vaccination. Several different approaches that included summary measures from the network reduced bias and improved confidence interval coverage. Through simulations, we showed the pitfalls of ignoring assortativity by vaccination. While our example is described in terms of vaccines, our results apply more widely to exposures for contagious outcomes. Assortativity should be considered when evaluating exposures for contagious outcomes.
Ginsenoside Rh1 attenuates ovalbumin-induced asthma by regulating Th1/Th2 cytokines balance
Authors: Li Qiang , Zhai Chunmiao , Wang Guodong , Zhou Jia , Li Weiguang , Xie Liquan , Shi Zhanli
Published: May 2021

Ginsenoside Rh1 (Rh1) has anti-inflammatory effects in asthma mice, but the underlying mechanism remains unclear. BALB/c mice were sensitized and challenged with ovalbumin (OVA) to construct asthma model. Mice received Rh1 or tiotropium bromide 0.5 h before OVA challenge. Airway morphology and airway remodeling were assessed by HE staining and Masson's trichrome staining, respectively. Th1/Th2 cytokines in serum or broncho alveolar lavage fluid (BALF) were measured by ELISA kits. Rh1 significantly alleviated the lung resistance and airway resistance, and reduced the number of total inflammation cells, eosinophils, neutrophils, and lymphocytes in BALF of the asthmatic mice. The morphological changes and collagen deposition of airway were also reduced by Rh1 in asthmatic mice. The increase of Eotaxin, IL-4, IL-5, IL-13, and IL-33 and the decrease of IL-12 and IFN-γ in both BALF and serum of OVA exposed mice were reversed by Rh1. Rh1 attenuates OVA-induced asthma in the mice model by regulating Th1/Th2 cytokines balance.