bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent developments in the synthesis of chemically modified nanomaterials for use in dielectric and electronics applications
Authors: Tawade Bhausaheb V , Apata Ikeoluwa E , Singh Maninderjeet , Das Priyanka , Pradhan Nihar , Al-Enizi Abdullah M , Karim Alamgir , Raghavan Dharmaraj
Published: December 2020

Polymer nanocomposites (PNC) have attracted enormous scientific and technological interest due to their applications in energy storage, electronics, biosensing, drug delivery, cosmetics and packaging industry. Nanomaterials (platelet, fibers, spheroids, whiskers, rods) dispersed in different types of polymer matrices constitute such PNC. The degree of dispersion of the inorganic nanomaterials in the polymer matrix, as well as the structured arrangement of the nanomaterials, are some of the key factors influencing the overall performance of the nanocomposite. To this end, the surface functionalization of the nanomaterials determines its state of dispersion within the polymer matrix. For energy storage and electronics, these nanomaterials are usually chosen for their dielectric properties for enhancing the performance of device applications. Although several reviews on surface modification of nanomaterials have been reported, a review on the surface functionalization of nanomaterials as it pertains to polymer dielectrics is currently lacking. This review summarizes the recent developments in the surface modification of important metal oxide dielectric nanomaterials including Silicon dioxide (SiO2), titanium dioxide (TiO2), barium titanate (BaTiO3), and aluminum oxide (Al2O3) by chemical agents such as silanes, phosphonic acids, and dopamine. We report the impact of chemical modification of the nanomaterial on the dielectric performance (dielectric constant, breakdown strength, and energy density) of the nanocomposite. Aside from bringing novice and experts up to speed in the area of polymer dielectric nanocomposites, this review will serve as an intellectual resource in the selection of appropriate chemical agents for functionalizing nanomaterials for use in specific polymer matrix so as to potentially tune the final performance of nanocomposite.
Hundreds-GeV Au ion generation by 1022–24 W cm−2 laser pulses interacting with high-Z grain doped gas
Authors: Zhao N , Zou D B , Jiang X R , Yu T P , Yu M Y , Liu K , Huang T W , Zhang H , Wu S Z , Hu L X , Zhang G B , Yin Y , Shao F Q , Zhuo H B , Zhou C T
Published: December 2020

Collision of intermediate-energy heavy ions is an important way to investigate the state of high-density nuclear matter and formation of quark gluon plasmas. In this paper, we demonstrate from two-dimensional particle-in-cell simulations that hundreds-GeV Au79+ ions can be generated by ultrashort ∼1022–24 W cm−2 lasers interacting with high-Z grain doped gas. Under extremely intense laser field, strong γ-ray radiation has resulted in massive laser energy loss, and the invoked radiation reaction trapping of electrons weakens the heavy ion acceleration. However, due to hole-boring acceleration and multi-body expansion acceleration of high-Z grains, the energy conversion efficiency from laser to heavy ions is still up to 32%. Our results might provide an effective routine to carry out the experimental explorations of heavy-ion collisions by using hundreds-petawatt laser facilities.
Observation and control of quantized scattering halos
Authors: Chatelain G , Dupont N , Arnal M , Brunaud V , Billy J , Peaudecerf B , Schlagheck P , Guéry-Odelin D
Published: December 2020

We investigate the production of s-wave scattering halos from collisions between the momentum components of a Bose–Einstein condensate released from an optical lattice. The lattice periodicity translates in a momentum comb responsible for the quantization of the halos’ radii. We report on the engineering of those halos through the precise control of the atom dynamics in the lattice: we are able to specifically enhance collision processes with given center-of-mass and relative momenta. In particular, we observe quantized collision halos between opposite momenta components of increasing magnitude, up to 6 times the characteristic momentum scale of the lattice.
Interlayer Hebbian plasticity induces first-order transition in multiplex networks
Authors: Kachhvah Ajay Deep , Dai Xiangfeng , Boccaletti Stefano , Jalan Sarika
Published: December 2020

Adaptation plays a pivotal role in the evolution of natural and artificial complex systems, and in the determination of their functionality. Here, we investigate the impact of adaptive interlayer processes on intra-layer synchronization in multiplex networks. The considered adaptation mechanism is governed by a Hebbian learning rule, i.e., the link weight between a pair of interconnected nodes is enhanced if the two nodes are in phase. Such adaptive coupling induces an irreversible first-order transition route to synchronization accompanied with a hysteresis. We provide rigorous analytic predictions of the critical coupling strengths for the onset of synchronization and de-synchronization, and verify all our theoretical predictions by means of extensive numerical simulations.
Position distribution calculation of annihilation radiations and bremsstrahlung x rays in water during irradiation of positive muons: a Monte Carlo simulation study
Authors: Hirano Yoshiyuki , Yamamoto Seiichi , Kawamura Naritoshi , Ninomiya Kazuhiko
Published: December 2020

Range, momentum and deviation of momentum determinations of muons are important for quality assessment (QA) of beams. Imaging of annihilation radiations emitted from positrons decayed from positive muons and that of bremsstrahlung x-rays emitted from positrons and secondary electrons from positive muons are possible methods of imaging muons. However, the energies and intensities as well as position distributions of these radiations have not been obvious. Thus we calculated the energy spectrum and the distributions of annihilation radiations as well as bremsstrahlung x-rays produced in water during irradiation of positive muons using Monte Carlo simulation. The calculations were conducted for 84.5 MeV /c positive muons, which is the same beam condition used in an experimental facility at the Japan Proton Accelerator Research Complex (J-PARC). We were able to calculate the energy spectrum as well as the position distributions of annihilation radiations and bremsstrahlung x-rays. The energy spectrum showed a broad distribution of bremsstrahlung x-rays, mainly from decayed positrons with an energy range up to 50 MeV with higher intensity in low-energy bremsstrahlung x-rays. The spectrum also showed a sharp peak at 511-keV from annihilation radiations. The position distribution of annihilation radiations was wider than those of the bremsstrahlung x-rays. The position distribution of the bremsstrahlung x-rays were nearly identical to the Cerenkov-light position distribution emitted by the decayed positrons in water. We conclude that imaging of bremsstrahlung x-rays from decayed positrons by using an x-ray camera is a promising method for the QA of positive muons and that higher spatial resolution images of positron distributions will be measured than those measured by annihilation radiations.
Impact of varying preparation methods of colloidal suspensions on droplet desiccation patterns on hydrophobic and hydrophilic substrates
Authors: Khatun Ammara , Haque Samiul , Tarafdar Sujata , Dutta Tapati
Published: December 2020

The patterns left by desiccating droplets of colloidal solutions form an integral part of a gamut of applications in technology, medicine and fundamental science. While almost all attention is reserved for understanding flow dynamics of drying droplets and the resulting dried droplet pattern with respect to variation of a host of parameters, there is almost a total absence of any discussion on the importance of the ‘mixing methods’ of solute and solvent during solution preparation. We demonstrate in this work, that desiccation patterns of colloidal solutions show an amazing variation in details, depending on the manner of solution preparation. The variation is achieved by simple mechanical treatment, namely magnetic stirring and ultrasonication, and for different stirring times. The suitable explanation of the striking variation in the dried droplets on both hydrophilic and hydrophobic substrates lead us to propose that the stirring time corresponding to a particular method adopted for solution preparation, results in varying degrees of paring of aggregates. We establish that a homogeneous colloidal solution can only be achieved by mixing for a minimum time t

std
, that is a function of a particular mixing procedure and a given solute-solvent combination. The prepared solution may then be used in different applications to obtain faithful standard results.
Multisoliton solutions with even numbers and its generated solutions for nonlocal Fokas–Lenells equation
Authors: Fan Rong , Zhang Zhao , Li Biao
Published: December 2020

In this letter, we investigate multisoliton solutions with even numbers and its generated solutions for nonlocal Fokas–Lenells equation over a nonzero background. First, we obtain 2n-soliton solutions with a nonzero background via n-fold Darboux transformation, and find that these soliton solutions will appear in pairs. Particularly, 2n-soliton solutions consist of n ‘bright’ solitons and n ‘dark’ solitons. This phenomenon implies a new form of integrability: even integrability. Then interactions between solitons with even numbers and breathers are studied in detail. To our best knowledge, a novel nonlinear superposition between a kink and 2n-soliton is also generated for the first time. Finally, interactions between some different smooth positons with a nonzero background are derived.
Novel fast-switching LIGBT with P-buried layer and partial SOI*
Authors: Wang Haoran , Duan Baoxing , Sun Licheng , Yang Yintang
Published: December 2020

A novel silicon-on-insulator lateral insulated gate bipolar transistor (SOI LIGBT) is proposed in this paper. The proposed device has a P-type buried layer and a partial-SOI layer, which is called the BPSOI-LIGBT. Due to the electric field modulation effect generated by the P-type buried layer and the partial-SOI layer, the proposed structure generates two new peaks in the surface electric field distribution, which can achieve a smaller device size with a higher breakdown voltage. The smaller size of the device is beneficial to the fast switching. The simulation shows that under the same size, the breakdown voltage of the BPSOI LIGBT is 26% higher than that of the conventional partial-SOI LIGBT (PSOI LIGBT), and 84% higher than the traditional SOI LIGBT. When the forward voltage drop is 2.05 V, the turn-off time of the BPSOI LIGBT is 71% shorter than that of the traditional SOI LIGBT. Therefore, the proposed BPSOI LIGBT has a better forward voltage drop and turn-off time trade-off than the traditional SOI LIGBT. In addition, the BPSOI LIGBT effectively relieves the self-heating effect of the traditional SOI LIGBT.
Effect of cell-nanostructured substrate interactions on the capture efficiency of HeLa cells
Authors: Kong Jinlong , Liu Yang , Du Xiangbin , Wang Kaiqun , Chen Weiyi , Huang Di , Wei Yan , Mao Haiyang
Published: December 2020

Circulating tumor cells (CTCs) are regarded as an effective biomarker for cancer detection, diagnosis and prognosis monitoring. CTCs capture based on nanostructured substrates is a powerful technique. Some specific adhesion molecule antibody coated on the surface of nanostructured substrates, such as EpCAM, is commonly used to enhance the CTCs capture efficiency. Substrate nanotopographies regulate the interaction between the substrates and captured cells, further influencing cell capture efficiency. However, the relationship between cell capture efficiency and cell–substrate interaction remains poorly understood. Here, we explored the relationship between cell capture efficiency and cell–substrate interaction based on two sets of nanostructures with different nanotopographies without antibody conjugation. Given the urgent demand for improving the capture efficiency of EpCAM-negative cells, we used HeLa (EpCAM-negative) cells as the main targets. We demonstrated that HeLa cells could be more effectively captured by two nanostructural substrates, especially by double-layer composite nanoforests. Therefore, the morphological and migrating interaction between HeLa cells and distinct substrates was associated with cell capture efficiency. Our findings demonstrated the potential mechanism for optimizing the nanotopography for higher capture efficiency, and provide a potential foundation for cancer detection, diagnosis and treatment.
How do weather and climate change impact the COVID-19 pandemic? Evidence from the Chinese mainland
Authors: Fan Jing-Li , Da Yabin , Zeng Bin , Zhang Hao , Liu Zhu , Jia Na , Liu Jue , Wang Bin , Li Lanlan , Guan Dabo , Zhang Xian
Published: December 2020

The COVID-19 pandemic continues to expand, while the relationship between weather conditions and the spread of the virus remains largely debatable. In this paper, we attempt to examine this question by employing a flexible econometric model coupled with fine-scaled hourly temperature variations and a rich set of covariates for 291 cities in the Chinese mainland. More importantly, we combine the baseline estimates with climate-change projections from 21 global climate models to understand the pandemic in different scenarios. We found a significant negative relationship between temperatures and caseload. A one-hour increase in temperatures from 25 °C to 28 °C tends to reduce daily cases by 15.1%, relative to such an increase from −2 °C to 1 °C. Our results also suggest an inverted U-shaped nonlinear relationship between relative humidity and confirmed cases. Despite the negative effects of heat, we found that rising temperatures induced by climate change are unlikely to contain a hypothesized pandemic in the future. In contrast, cases would tend to increase by 10.9% from 2040 to 2059 with a representative concentration pathway (RCP) of 4.5 and by 7.5% at an RCP of 8.5, relative to 2020, though reductions of 1.8% and 18.9% were projected for 2080–2099 for the same RCPs, respectively. These findings raise concerns that the pandemic could worsen under the climate-change framework.
BLUES iteration applied to nonlinear ordinary differential equations for wave propagation and heat transfer
Authors: Berx Jonas , Indekeu Joseph O
Published: December 2020

The iteration sequence based on the BLUES (Beyond Linear Use of Equation Superposition) function method for calculating analytic approximants to solutions of nonlinear ordinary differential equations with sources is elaborated upon. Diverse problems in physics are studied and approximate analytic solutions are found. We first treat a damped driven nonlinear oscillator and show that the method can correctly reproduce oscillatory behavior. Next, a fractional differential equation describing heat transfer in a semi-infinite rod with Stefan–Boltzmann cooling is handled. In this case, a detailed comparison is made with the Adomian decomposition method, the outcome of which is favourable for the BLUES method. As a final problem, the Fisher equation from population biology is dealt with. For all cases, it is shown that the solutions converge exponentially fast to the numerically exact solution, either globally or, for the Fisher problem, locally.
Semiclassical treatment of quantum chaotic transport with a tunnel barrier
Authors: Bento Pedro H S , Novaes Marcel
Published: December 2020

We consider the problem of a semiclassical description of quantum chaotic transport, when a tunnel barrier is present in one of the leads. Using a semiclassical approach formulated in terms of a matrix model, we obtain transport moments as power series in the reflection probability of the barrier, whose coefficients are rational functions of the number of open channels M. Our results are therefore valid in the quantum regime and not only when M ≫ 1. The expressions we arrive at are not identical with the corresponding predictions from random matrix theory, but are in fact much simpler. Both theories agree as far as we can test.
Research on Cleansing and Drying System of Rice Husk before Pyrolysis
Authors: Luan Zhenhui , Chen Tao , Zhang Liming
Published: December 2020

Rice husk gasification technology has been concerned by many scholars at home and abroad. Because the rice husk contains too much impurities and dust, too much air is mixed into the combustion, which affects the purity of pyrolysis gas, causing difficulties in gas purification, blockage and corrosion of pipelines and other problems. In order to improve the quality of rice husk pyrolysis gas, the authors designed a cleansing and drying system of rice husk before pyrolysis. This paper analyzed the design principle of the system, designed the structure of screw conveyor and the dryer, determined the structure parameters of the system. The study indicates that the system can cleanse and dry the rice husk into the system, and can be used as a pretreatment device for rice husk pyrolysis.
Study on the Quantitative Measurement Technique of the Micro Fracture Surface
Authors: Liu Xiaolan , Zheng Yong , Ma Yongqian
Published: December 2020

The quantitative study on the distribution of cracks and micro cracks is a major problem in the study of reservoir properties of tight and lithologic regions In view of this problem, the present study is to evaluate the cracks by indirect method, and the direct evaluation method is lack of micro cracks This paper tries to combine the results of electronic scanning electron microscopy and image data processing method, which can directly test the density of micro cracks The test results prove that the method is convenient and feasible, and has a strong reference value for engineering practice and scientific research.
Theoretical and Empirical Analysis on the Transformation of Energy Consumption New Mode
Authors: Zhao Liujun , Wang Yinan , Lin Liu , Jie Li
Published: December 2020

The innovation of energy consumption modes plays an important role in solving energy development problems of China. This paper proposes a theoretical system for the transformation of energy consumption modes. Through the analysis of four elements of energy consumption mode, and their internal and external influence factors, four types of energy consumption new mode are derived, namely, integrated, sharing, intelligent and green patterns. These new modes present the features of digitalization, marketization, high efficiency, electrification and cleaning in the future. Finally, a transformation analysis index system is built to evaluate and prospect the future energy consumption modes. The new energy consumption modes in the future show the features of ‘technology before the market’. The main features of energy consumption modes are digital and efficient in the early stage. In the later period, the characteristics of cleaning, marketization and electrification are obvious.
Optimization of Heavy Metal Cu(II) Adsorption by Cotton Straw Biochar Using Response Surface Methodology
Authors: Hu Xuefei , Liu Chong , Yue Shengru , Li Fayong , You Yongjun , Wang Shan
Published: December 2020

Box–Behnken response surface optimization design was used to improve the process of Cu(II) removal from water by cotton straw biochar (CSBC). The pH of the solution, and the dosage and temperature of the CSBC were set as the three influencing factors. The Cu(II) equilibrium adsorption amount was taken as the response value. The quadratic polynomial model between the equilibrium adsorption amount and the above factors was established, optimal adsorption conditions were determined, and model fitting on the thermodynamic adsorption process was conducted under optimal conditions. The results showed that the amount and temperature of CSBC were the significant factors. When the pH was 6.00, the amount of CSBC was 0.20 g/l, the temperature was 45 °C, and adsorption capacity of CSBC to Cu(II) was the largest. The adsorption model conformed to the Freundlich isotherm equation. The adsorption of Cu(II) by CSBC belonged to a multimolecular layer adsorption, and the adsorption effect was significant. As a green, efficient, and cheap adsorbent, CSBC can be used to remove Cu(II) from wastewater.
Plugging Performance Evaluation of Nanoemulsion in Ultrafine Drilling and Completion Fluid by Pressure Conduction Method
Authors: Ye Yan , Sheng Yong , Zhang Qingwen , Luo Wei , Zhou Fujian
Published: December 2020

The paper is proposed to introduce nanoemulsion into the ultra-drilling completion fluid system to improve the plugging performance. The pressure conduction method was used to evaluate the plugging properties of tight sandstone, the evaluation results showed that the fluid loss of ultrafine drilling and completion fluid with nanoemulsion was reduced to 6.3 mL, and the pressure difference between the upstream and downstream reaches 0.29 MPa Plugging Property of ultrafine drilling and completion fluid with nanoemulsion is double higher than without nanoemulsion, and was 2.96 times higher than only nanoemulsion. The nano-emulsion and micro-nano solid particles in the ultrafine drilling fluid can seal the plugging layer after entering the pore throat, it can play a role in retarding pressure transmission and filtrate intrusion, and enhancing the plugging effect. The experimental results provide a certain reference value for the follow-up study of the sealing properties of the nanoemulsion.
Wellbore Stabilization Technology for Fractured Formation in Shunbei No.5 Fault
Authors: Li Shuanggui , Liu Jingtao , Yu Yang , Zhong Wenjian
Published: December 2020

Basic geological background, drilling fluid formulation optimization and field application were carried out aiming at the technical problems of multiple blocks in Shunbei Oilfield when collapsing strata and collapsing and blocking frequently. The lithology of the fracture zone is non-clay minerals. After the drilling fluid or filtrate is eroded, the self-developed pore network is easily pressurized and connected, which reduces the adhesion of the bedding interface, which in turn induces large-scale spalling and slump stuck. Based on the mechanism of the instability of the borehole wall, a submicron-micron (0.1-100μm) comprehensive and effective plugging is proposed to prevent drilling fluid or filtrate from invading the formation pores and fractures around the well, and at the same time ensure that the drilling fluid has an efficient rock-carrying solution. The technical achievements carried out on-site tests at Shunbei No. 5, based on the original Sikai high-temperature polysulfonate drilling fluid, optimized the indoor formulation, and developed a wellbore stable drilling fluid suitable for broken formations. During the application process, there were no drilling accidents such as block blockage, which was the shortest record of drilling time in the reservoir section of the block.
Evaluation and Improvement of the Coupled Effect of High-temperature Corrosion-erosion on Water Wall Tubes
Authors: Qin Ming , Jin Jun , Yan Mingqi , Tan Yaping , Liu Hui
Published: December 2020

Low-alloy and heat-resistant steel generally shows good anti-corrosion performance. Also unlike CFB boiler, there is little serious erosion happening in furnace of the pulverized coal boiler due to the low particle concentration. But when subjected to the coupled effect of high-temperature corrosion-erosion, serious failures would occur. This study analyzed the reason for eroded failure of water wall tubes of a 660 MW supercritical boiler with pulverized coal combustion, concluding that such failure resulted from the coupled effect of high-temperature corrosion-erosion. Analysis of the failed sample determined that failure was caused by the combination of high-temperature corrosion-erosion and the rate of failure was faster than that occurring solely by erosion. The numerical simulation result also showed that the H2S concentrations of the fault areas are much higher than others which are coincide with the fact. Furthermore, the study proposed the way of improving the situation for the special four-wall tangential firing through numerical simulation.
Emergy Analysis of Agricultural Ecosystem in Shouguang City, Shandong Province
Authors: Mu Lin , Wang Yan , Zhao Tianhong , Ma Jian
Published: December 2020

By using the method of emergy analysis, this paper analyzed agricultural industrial structure and the emergy input, output and emergy index of agricultural ecosystem in Shouguang City from 2007 to 2016, which reflected the development trend of agricultural ecosystem. The results showed that the total emergy input of agricultural ecosystem in Shouguang City from 2007 to 2016 was in a downward trend, and the change trend of total emergy output was in a downward and then upward trend. From the emergy index, the economic input of agricultural ecosystem in Shouguang City was large, the environmental utilization was not sufficient, but the pressure on the environment was small, and the agricultural ecosystem in Shouguang City was in a sustainable state Continuous development status.
Market Status and Development Prospects of Virtual Power Plants
Authors: Ying Zhiwei , Yu Tao , Huang Yupeng , Liu Dunnan , Jia Heping , Chen Chunyi
Published: December 2020

With the development of new energies and smart grids, virtual power plants (VPPs) have gradually attracted the academia and industries all over the world. VPPs, which are expected to become the supporting framework of smart grid technologies considering new energy integration, break the boundary between power generation side and power consumption side in traditional power systems and makes full use of advanced technical means such as network communication, intelligent measurement and intelligent decision. The concept and characteristics of VPPs are first introduced as well as the market status and demonstration projects of VPPs in different countries. Then, the development prospects of VPPs are pointed out from the aspects of market scope, smart grid construction, demand side response, power trading curve and market potential. Finally, in terms of the unification of the concept, profit model, market potential, and market mechanism, the corresponding solutions to the urgent challenges of VPPs are proposed.
Simulation Research on Performance of Synchronous DC Converter Considering Temperature Rise Effect
Authors: Zhou Ke , Yang Qianwen , Wang Xiao
Published: December 2020

In this paper, the effect of temperature rise of MOSFET on output performance of synchronous dc converter is studied. Firstly, the power loss calculation method and thermal resistance equivalent circuit of switching devices are analyzed, and mathematical modeling is carried out for the conduction mode and change rule of junction temperature, housing temperature and radiator temperature of switching devices, and the MOSFET temperature rise model is built in Matlab environment, and the temperature rise curves of different parts of MOSFET switching devices are obtained. By means of the model, the effect of temperature rise on the output and control signal of the synchronous DC converter is studied. The simulation results show that the effect of temperature rise on the switching device will increase the internal resistance of the switching device, decrease the gate opening voltage and reduce the output voltage. In the real circuit design, it is necessary to leave a margin for the above parameters to ensure an ideal output.
Assessment of the Impact of the Forecast Uncertainty of Wind and Photovoltaic Generation on Large-scale Power Transmission
Authors: Dai Sai , Ding Qiang , Yuan Kaiming , Hou Yanqiu , Lin Jikeng
Published: December 2020

In this paper, we proposed a method to assess the impact of the uncertainty of forecast error of wind and photovoltaic generation on power transmission. First, we proposed a probabilistic model to characterize the uncertainty of the forecast error and established an index system to assess the performance of the transmission system in various aspects. Second, we adopted the Latin hypercube sampling technique to obtain the expectation and the variance of the assessment indices. Third, we introduced a sensitivity method to measure the variation of the probabilistic characteristics of the assessment indices propagated from the variation of the forecast error. Finally, we used a stochastic multi-attribute decision-making method to make the ranking of all renewable power plants by the comprehensive influence of the uncertainty of forecast error on them. With this ranking, it is able to judge which renewable power plant’s forecast accuracy should be improved in order to most effectively control the error of the power transmission. The effectiveness of the proposed models and methods are briefly verified by a case.
Adaptability Analysis and Optimization of Oil Well Energy Saving Motor
Authors: Zheng Yong
Published: December 2020

Motor is the core energy consumption node of mechanical mining system, and also the key point of energy saving potential of mechanical mining system. At present, there are two main problems in the use of matching motor of mechanical oil production system: one is that the types of oil well motor are complex and the performance index is uneven; the other is that the oil well working conditions are complex and diverse, and there is no basis for motor selection.

In view of the above problems, in order to reduce the power consumption of high energy consumption motor, improve the rationality and scientificity of oil well energy-saving motor selection and matching work, effectively improve the operation efficiency of mechanical production system and reduce energy consumption, the adaptability of oil well energy-saving motor is carried out. Taking the energy-saving motor of oil pumping unit as the research object, through no-load, locked rotor, pumping unit simulated load, field calibration and other testing means This paper evaluates the comprehensive quality of the energy-saving motor of oil well from the systematic point of view, and studies the optimization method of the matching between the energy-saving motor and the pumping unit.
Effect of Wind Turbine Blade Profile Surface Roughness on Ice Accretion – A Numerical Case Study
Authors: Jin Jia Yi , Virk Muhammad S.
Published: December 2020

A parametric numerical study of wind turbine blade profile surface roughness has been carried out to investigate its effects on boundary layer characteristics and accreted ice growth. DU96-W-180 blade profile is used in this paper. Multiphase numerical analysis has been performed at glaze ice conditions for three different surface roughness values: Shin et al. surface roughness model and two specific roughness values (0.03m and 0.0003m). Study shows that surface roughness considerably effects the shear stresses as well as heat fluxes, which results a variation of ice accretion in rate and shape. Results show that accreted ice mass and ice thickness increases with the increase of surface roughness.
Traveling-Wave-Based Fault Location Method for Hybrid Distribution Network Mixed with Three-Phase and Phase to Phase Supply Lines
Authors: Xinyu Zhang , Yu Nie , Chuanzong Zhao , Wei Du , Yanan Wang , Zhigang WANG , Yanbing LIU
Published: December 2020

In China, a hybrid distribution network mixed with three-phase main lines and phase to phase supply lines can be found in many MV distribution networks due to lower cost of using two lines from three-phase main lines as well as lower cost of phase to phase transformer. For such a hybrid distribution network it is a challenge for traditional fault location techniques. This paper presents a traveling wave fault location method based on double-terminal measurement techniques. The proposed method analyses the traveling wave propagation mechanism of both aerial mode and zero mode components for a fault. The method then determines which mode component is used for the fault location according to fault types. The method has been developed and assessed on a typical distribution network using ATP power network simulation tool. The tests were conducted under various fault scenarios. The results show that zero mode component is more effective for a fault on the phase of three-phase main lines which is not linked to the phase to phase supply lines. However for a phase-to-phase fault, aerial mode component is more effective. For the remaining fault types, either aerial or zero mode component can be used.
A Novel Electromagnetic Flowmeter for Liquid Metal of Nuclear Reactors
Authors: Li Xuejing
Published: December 2020

Electromagnetic flowmeters (EMFM) play an important role in the cooling process of nuclear reactors, especially when the coolant is liquid metal. According to the working principle of the electromagnetic flowmeter, it is necessary to use a large-sized magnet to provide a uniform magnetic field, but this is very difficult for a core with limited space. This paper proposes a novel electromagnetic flowmeter with a single cylindrical permanent magnet. Compared with the conventional flowmeter, the volume of this electromagnetic flowmeter is greatly reduced. This paper perfects the theory of this single magnet flowmeter and compares it with the experimental results.
Study on Mechanical Performance of Connection jointsIn Novel Modular Steel Structure Buildings
Authors: Hu Qi , Lin Bing , Xie Yonglan , Chen Wenqiang
Published: December 2020

The overall mechanical performance of modular steel structure buildings are largely determined by the mechanical performance of the connection joints between the adjacent modules. In this paper, a novel connection joints between the adjacent modules is taken as research object, which has the advantages of convenient construction and assembly. By means of FEA, three models including the joint model, the model of adding ribs and the model of increasing beam height are calculated, and the experimental results were compared. The finite element model uses solid elements to simulate the detail structure of joints and contact elements to the contact relationship between components. The research results show that the results of finite element analysis are in good agreement with the experimental results in terms of deformation state and bearing capacity, and the accuracy of the finite element model is verified. The finite element model established in this paper can simulate the stress state of various parts of the joint which can make up for the shortage of the experimental measurement.
Portable Soil Electrical Conductivity Sensor System Based on Electromagnetic Pulsed Eddy Current method
Authors: Zhang Qi , Fu Yingchun
Published: December 2020

Soil salinization is one of the major environmental geological concerns around the world. The rapid survey of soil conductivity is urgent to reflect the salinization degree in time, while current methods rely on lab-test or electronic probe-based ones, which are not efficient on saving cost and improving efficiency. In this paper, a new electrical conductivity sensor based on electromagnetic pulsed eddy current strategy is proposed to meet the purpose of rapid and efficient survey of soil conductivity. Relevant software was also designed and tested. To facilitate the in-field test, a portable system was constructed.
Research on Outburst Prevention Method in Deep Coal Road Strip Area
Authors: Wang ZHonghua
Published: December 2020

Aiming at the prevention of outburst in the strip area of deep coal roadways with high geostress, it proposed a method for prevention of outburst in the strip area of coal roadways in which the pressure relief floor roadway is pre-excavated, and it is applied in Fengcheng mining area. The application shows that the method has obvious anti-outburst effects, technical and economic benefits, and broad application prospects.
Peculiarities of the floristic composition and phytocenotic spectra of the prospective conservation area “Siverga” (Tyumen Oblast, Russia)
Authors: Kapitonova O A , Lysenko T M
Published: December 2020

The coastal zone of the Lake Siverga (Tyumen Oblast, Russia) is characterized by a high level of floristic and phytocenotic diversity, which significantly increases the conservation status of the prospective protected area “Siverga”, limited by the coastline of the lake. Twelve vascular plants species included into the Red List of the Tyumen Oblast have been found on the surveyed territory. The plant communities, which are extremely rare in the region, have been observed on the coastal salt marshes; these communities have been previously noted only in the southern areas of the European part of Russia. Taking into account these results, we argue for expanding the boundaries of the protected natural area, which must include the floodplain areas and slopes of the floodplain terrace adjacent to the lake water area.
Regulation of reproduction rate in terrestrial placental mammals
Authors: Vekhnik Victoria A.
Published: December 2020

Mechanisms of regulation of reproduction are studied in a limited number of mammalian species, but these studies are extremely important for the conservation of rare animals. This study is a review of the data on reproductive biology of over 120 mammalian species. Four hierarchical levels of regulation of reproduction rate in mammalian females are identified: regulation of the number of embryos, regulation of the oestrous cycle, regulation of the number of females participating in reproduction, and regulation of reproduction rate at the population level. This classification makes it possible to draw a number of conclusions: (1) the mechanisms of reproductive regulation may be similar in distant taxonomic groups; (2) completely different regulatory mechanisms can be realized simultaneously in the same species at various levels; (3) the higher the level of regulation, the greater the number of individuals participating; (4) the nutritional factor is of integral importance and affects reproduction rate at all levels; (5) at the population level, the mechanism of anticipatory reproduction evolves, being a natural regulatory mechanism. The studies of reproductive restrictions in males may appear as a fruitful area for obtaining new data about regulation of reproduction rate in populations. The role of male reproductive activity in the regulation of reproduction seems highly underestimated.
Research of industrial noise impact to the urban environment on the example of enterprises of north industrial unit of Togliatti city of Russia
Authors: Vasilyev A V
Published: December 2020

Environmental noise impact is increasing every year and may cause serious negative problems for inhabitants of urban territories and for specially protected natural areas. Industrial noise is one of the main noise sources of the urban territories of modern towns. On the territory of Togliatti city of Russia the part of the Middle Volga Integrated Biosphere Reserve is located. Results of analysis of environmental noise sources on the territory of north industrial unit of Togliatti city are considered. Methods of analysis of environmental noise in Russia are analysed. Results of measurements of environmental noise in the zone of north industrial unit of Togliatti city are presented. Practically in all noise measuring the exceeding noise values were determined. Measurement results of noise characteristic directly in the territories of industrial enterprises are showing that the main noise sources, especially in low frequency range, are power plants. Noise map of the territory of the north industrial unit of Togliatti city have been developed. In total, it is possible to make a conclusion about the existing of real problem of increased noise impact of industrial enterprises to the population.
Driving Characteristics Analysis of Light-duty Vehicle RDE Test in Plain and Plateau
Authors: Lyu H , Li J , Fu T
Published: December 2020

In this paper, 8 real-driving emission (RDE) tests were conducted by using a portable emission measurement system (PEMs), and the intensity value was defined to quantitatively express the driving intensity of vehicles. Four plains RDE experiment and four plateau RDE driving characteristics were analysed. At the same time, the transient characteristics of plain test 3 and plateau test 2 with close and stable driving intensity and plain test 1 with high driving intensity were compared. Results show that compared with the plain RDE test, driving intensity of plateau RDE test overall is low, and the frequent acceleration and deceleration times of the plateau RDE test in the urban section are few, besides the acceleration is relatively large. The intensity of driving can have a big impact on pollutant emissions, especially in highway section. The acceleration of the plateau RDE test in the urban section is large, and the CO emission is high due to the climatic conditions and road conditions. Therefore, the frequent acceleration process of the plateau test in the urban section should be paid special attention to when the vehicle is conducting calibration test. In conclusion, from a test method point of view, the driving intensity of the RDE test should be required; From the point of view of calibration development, we should focus on the condition of high driving intensity.
Research on the Recognition of Infrasound Signal of Nuclear Explosion by SVM and CNN
Authors: Wu Yunhui , Zhang Jiemin , Chen Xingmin , Zou Shiya , Yang Ming
Published: December 2020

Infrasound monitoring is a nuclear test monitoring technology of the CTBTO’s international monitoring system. In order to improve the accuracy rate of atmospheric infrasound signal recognition, the recognition effectiveness of convolutional neural network(CNN) and support vector machine(SVM) are studied. According to the features of nuclear explosion infrasound, the related features are extracted from other types of signals. SVM model and CNN model are used in the experiment, and a method is designed to improve the recognition efficiency. It converts infrasound signals into images, and then uses CNN to recognize them, and the learning process is improved by combining with GAN. Compared with SVM method based on artificial design features, the experimental results show that in the case of small training data set, CNN with improved learning process can dig out the potential features of signals, and has the same recognition ability as SVM. But the recognition ability of nuclear explosion and chemical explosion is slightly better than that of SVM.
Prediction of the Optimum Conditions for Hydraulic Cleaning Process of Typical Organic Foulants on the Membrane Surface
Authors: Luo Huijia , Guo Yangyang , Wang Zhan
Published: December 2020

In order to systematically analyse the impacts of stirring speed, temperature and cleaning duration on the membrane flux during hydraulic cleaning, a series of experiments were carried out with the PAN MF membrane and SA solution. Through comparative analysis, it is found that the membrane flux increases with the increase of temperature and stirring speed, but there is a critical value for cleaning duration. Considering the swelling, dissolution and redeposition of foulants, a formula to predict the instantaneous membrane flux during hydraulic cleaning is proposed. This method was used to successfully predict the instantaneous permeate flux of the membrane during the hydraulic cleaning process on the membrane fouled with different foulants. This method can be embedded into the automatic cleaning program and will greatly save cleaning time and improve production efficiency.
Development of High Pressure and Constant Low Flow Test System for Hydraulic Support Safety Valve
Authors: Yi-cun Niu
Published: December 2020

The existing test equipment for safety valve with low-flow start and overflow closure characteristics of hydraulic support cannot provide the test conditions stipulated in relevant standards, which affects the accuracy of test results. Aiming at the shortage of the existing test equipment, a test system of high pressure and low flow rate of safety valve with hydraulic support is designed, and a technical solution of using straight line driver to push the plunger cylinder to realize high pressure and low flow rate of liquid supply is put forward. The simulation software AMESim was used to construct the virtual prototype of the test system, and the simulation analysis was carried out to determine the main parameters and the influencing rules of the rigidity of the liquid supply velocity. Based on the simulation study, prototype trial production, flow calibration and field experiment were completed. The experimental results showed that the instantaneous output flow fluctuation of the test system was within the range of ±10% of the rated value of 40ml/min, and the output flow fluctuation range was reduced by 25% compared with the existing way.
Creating a Humanistic Community under the Concept of Dialectical Deep Ecology: Constraints and Optimizations Go Hand in Hand
Authors: Yidan Liu , Qiao Ning
Published: December 2020

This paper discusses the implementation strategies of creating an eco-community in the new era from an overall perspective of ecological philosophy. First, based on the review and dialectical analysis of relevant research on eco-community and deep ecology, it points out the dilemma we are facing in the process of eco-community construction, the lack of implementation guidance between theory and practice in China, and the applicability of ecological philosophy perspective. It then proposes a coping attitude to create a people-oriented community under the overall ecological view; second, this paper makes a targeted analysis of the typical cases and gets some innovation inspiration; finally, based on the above theoretical and practical analysis, from the ecological, economic and social aspects, the paper puts forward the strategies of creating an eco-community with both constraints and optimization, to provide help for the transition stage of completing self-realization of ecological consciousness. This paper aims to jump out of the narrow humanism, start from the overall ecosystem to the concrete operation of creating a community, to better implement ecological strategies, and guide the community to complete the upgrade and transformation.
Dynamic beam-steering of graphene-based terahertz cross Yagi–Uda antenna with a theoretical approach
Authors: Moshiri Seyyed Mohammad Mehdi , Nozhat Najmeh , Khodadadi Maryam
Published: December 2020

In this paper, for the first time, a dynamic tunable graphene-based cross Yagi–Uda antenna in the terahertz region has been investigated comprehensively by two numerical methods and analytical analysis. To verify the accuracy of the analytical solution based on the coupled dipole method to obtain the directivity pattern, two numerical methods of finite-element and finite-difference time-domain have been used. Numerical results are well matched with the theoretical ones. By introducing the tunable cross Yagi–Uda antenna with graphene-coated spheres, different directivity radiation patterns such as omni-, vertical and horizontal bi- and quad-directional have been obtained with the maximum directivities of 2.42, 12.4, 12.3, and 10.5 dBi, respectively. Moreover, the effect of different element shapes including cube and cylinder on the directivity and radiation efficiency has been studied. Also, the new idea of multiple-access and controlling the user’s access to the radiated optical electromagnetic waves from the transmitting antenna has been studied as an optical wireless on-chip link. Finally, the effect of structural parameters on the directivity of the proposed antenna has been surveyed with the tolerance of ±5% to investigate the imperfections that may appear in the fabrication process.