bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards a framework of enforcing resilient operation of cyber‐physical systems with unknown dynamics
Authors: Nguyen Luan , Gupta Vijay
Published: April 2021

Ensuring that safety‐critical cyber‐physical systems (CPSs) continue to satisfy correctness and safety specifications even under faults or adversarial attacks is very challenging, especially in the presence of legacy components for which accurate models are unknown to the designer. Current techniques for secure‐by‐design systems engineering do not provide an end‐to‐end methodology for a designer to provide real‐time assurance for safety‐critical CPSs by identifying system dynamics and updating control strategies in response to newly discovered faults, attacks or other changes such as system upgrades. We propose a new methodology, along with an integrated framework implemented in MATLAB to guarantee the resilient operation of safety‐critical CPSs with unknown dynamics. The proposed framework consists of three main components. The runtime monitor evaluates the system behaviour on‐the‐fly against its correctness specifications expressed as signal temporal logic formulas. The model synthesiser incorporates a sparse identification approach that is used to continually update the plant model and control policies to adapt to any changes in the system or the environment. The decision and control module designs a controller to ensure that the correctness specifications are satisfied at runtime. For evaluation, we apply our proposed framework to ensure the resilient operations of two CPS case studies.
JCa2Co: A joint cascade convolution coding network based on fuzzy regional characteristics for infrared and visible image fusion
Authors: Xu Zhao , Liu Gang , Xiao Gang , Tang Lili , Li Yanhui
Published: April 2021

To facilitate the extraction of source image information, and preserve the consistency of heterogeneous regional features, a multiscale image fusion method based on a joint cascaded convolutional coding network (JCa2Co) is proposed. The JCa2Co network can retain vast quantities of information from source images in a multiscale perspective. The approach includes an encoder, a fusion layer and decoder. In the fusion layer, the Fuzzy Regional Characteristics (FRC) scheme is considered, and the multiscale feature maps are extracted from image subregions to ensure regional image consistency. Firstly, a joint cascaded encoder is used to extract multiscale features of the source image, in which the output of each layer is connected to every other layer. The fusion layer based on FRC is then performed to fuse each scale feature. Finally, the fused image is reconstructed by the decoder. In addition, to verify the regional consistency of the fused image, a regional consistency measure is proposed. Experiments are performed on the TNO Image Fusion Database. The experimental results exhibit that the proposed JCa2Co method has better comprehensive performance than the eight state‐of‐the‐art fusion methods. Moreover, it can effectively integrate meaningful information in infrared and visible images and has excellent performance in objective evaluation and visual quality, which is beneficial to target recognition and tracking.
Design and analysis of a high‐integration and low‐loss bearingless flywheel motor in vehicle
Authors: Yang Fan , Yuan Ye , Meng Gaojun , Yan Libin
Published: April 2021

This study investigates an outer rotor bearingless flywheel motor for flywheel batteries in vehicle that exhibits the advantages of high integration and low loss due to outer rotor direct‐drive and bearingless technologies. A hybrid excitation outer rotor bearingless flywheel motor with four‐degrees‐of‐freedom radial suspension and permanent magnet bias is also proposed, further improving the advantages of high integration and low loss. In addition, suspension force density is ameliorated and suspension–torque coupling is reduced through structure design. To verify the aforementioned advantages of hybrid excitation outer rotor bearingless flywheel motor, its working principles are introduced and its electromagnetic characteristics are analyzed using the finite element method. Comparisons with 12/8 ORBFM are also conducted by focusing on suspension loss and suspension force density.
Complex vector fitting toolbox: a software package for the modelling and simulation of general linear and passive baseband systems
Authors: Spina Domenico , Ye Yinghao , Deschrijver Dirk , Bogaerts Wim , Dhaene Tom
Published: April 2021

Complex vector fitting (CVF) is a robust method to efficiently and accurately model general linear and passive baseband systems. Such models are important for the analysis and design of modern electronic and optical communication systems. This letter introduces an efficient toolbox implementation of the CVF algorithm. The effectiveness of the code is illustrated on a suitable application example.
Improved CRC aided BP decoding for polar codes
Authors: Hong Sungkwon , Chung Jong‐Moon
Published: April 2021

In this letter, a modified message passing algorithm to prevent short cycles in the factor graph is proposed and combined with a relaxation technique to improve the performance of cyclic redundancy check aided belief propagation decoding for polar codes. Numerical results show that the proposed scheme can achieve a 0.7 dB coding gain, for the code rate of 0.5 at the block error rate of 10−5 with a comparable average number of iterations over the pure belief propagation decoding scheme when the code block length is 1024.
Chance‐constrained operation of the water‐energy nexus with conflicting objectives
Authors: Gao Ning , Wang Cheng , Liu Nian , Bi Tianshu
Published: April 2021

This paper focuses on the short‐term operation of the water‐energy nexus, where the energy sectors include electricity, natural gas, and heating power. The uncertainties of the renewable generation outputs and the heterogeneous load demands are considered, and their impacts on the operation of the water‐energy nexus are characterised through chance‐constrained modelling. Meanwhile, to achieve a reasonable trade‐off among different conflicting operation goals, such as the out‐of‐the‐pocket energy production costs and the water consumption amount, a bi‐objective decision‐making framework is established. The intractable chance constraints are converted into tractable ones under practical assumptions on the distributions of the uncertainties, where the Gaussian Mixture Model is used to fit the probability density distribution of wind power generation. The nonlinearities and nonconvexities in the proposed model are replaced by their convex approximations. An iterative penalty method is devised to recover the solution feasibility with respect to the original model. A fair compromise between the two conflicting objectives is obtained by the means of Nash bargaining. Simulation results verify the necessity and effectiveness of the proposed model and methods.
Performance analysis and optimization of polarized on‐body relay channels
Authors: Liu Lingfeng , Jin Jiabin , Zhang Peng , Xia Qin , Jiang Nan , Liu Zhiwei , Zhang Xiaoyan
Published: April 2021

On‐body propagation channels show significant polarization selectivity that has dominant impacts on the on‐body link quality in wireless body area networks. For on‐body relay channels over long distances across the body, the antenna polarization configurations of the relaying nodes are crucial to determine the relay performance, thereby requiring polarization optimization schemes. In this article, narrow band flat‐fading on‐body channels at 2.484 GHz are measured to analyse their polarization distribution above the skin under static postures. The measured on‐body channels show full‐space polarization convergence and dispersion, which are modelled by an extended 3 by 3 channel polarization matrix, and a statistical channel model is also proposed. Multi‐hop polarized on‐body relay channels are analysed on the relay link capacity, which shows polarization dependency between adjacent hop channels when relaying nodes are mounted by linearly polarized antennas. Both regular and iterative polarization selection algorithms are then designed to optimise the antenna polarization configuration of the nodes. Simulations based on the proposed polarization distribution model show significant link capacity increases for two‐hop and tfhree‐hop on‐body relay channels by the optimization algorithms. The results confirm the necessity of proper polarization selection schemes for on‐body relay channels.
Promising unconventional plant raw materials for food production
Authors: Belokurova Elena , Derkanosova Anna , Dombrovskaya Yana , Malyutina Tatyana
Published: April 2021

Article contains information about new technologies of flour and bakery products on the basis of multicomponent structure products or the flour composite mixes executed from a flour of pumpkin and a thistle, a dry leaf of a stevia and dry lactulose, and also mixes from different types of grain, such as: corn, buckwheat, rice, millet.
Prospects for use of new sources of dietary fibers in the technology of flour confectionery products
Authors: Samokhvalova Olga , Oliinyk Svitlana , Kasabova Kateryna , Stepankova Galyna , Bolkhovitina Olena
Published: April 2021

The rationale for enrichment of flour confectionery products with dietary fibers was shown and the use of plant raw materials by-products, namely wheat germ oil cake and beet fibers as the sources of such dietary fibers, was justified. The content of nutrients, the quantitative and qualitative composition of dietary fibers as well as the granulometric composition were determined in the studied additives. The functional and technological properties of additives such as water absorbing ability depending on water temperature and duration of swelling and fat binding capability were studied.
Influence of sodium alginate on the formation of the structure of the products from chopped and minced meat
Authors: Vasyukova Anna , Kononenko Marina , Moshkin Alexander , Vasyukov Maxim , Kushnarenko Anatoly , Binkovskaya Olga
Published: April 2021

The paper presents the results of using algae as a natural additive to chopped semi-finished meat products. The optimal ratio is set by means of the design method and the results of organoleptic assessment. The mathematical models that help to determine the optimal values of the factors and C, W and T (concentration of the components, moisture content and duration of mincing) are obtained.
Coordinating metal Mn2+ and Ni2+ compounds with acetylsalicylic acid: the influence on the cardiorespiratory system
Authors: Chuyan Elena , Ravaeva Marina , Cheretaev Igor , Mironyuk Irina , Chornobay Svitlana , Birukova Elena
Published: April 2021

The paper researches the effect of manganese (АCMn2+) and nickel (АCNi2+) acetylsalicylates in doses of 5 and 10 mg/kg on the characteristics of the rats’ cardiorespiratory system. It is ascertained that coordinating metal compounds with the acetylsalicylic acid have a more pronounced biological effect in comparison with a monocompound of the acetylsalicylic acid; this makes the further search for coordinating compounds’ effects more promising.
Efficiency of application in diets of high-productive cows of Actisaf SC 47
Authors: Aristov Alexander , Esaulova Lidia , Zuev Nikolay , Gorbunova Natalya
Published: April 2021

The paper discusses the technology of growing, keeping and feeding dairy cows in the conditions of Zolotaya Niva LLC, one of the largest high-tech dairy complex in the Smolensk region, a European type for the production of raw cow milk, which has the status of pedigree producer. The structure of the feed and the quality of mixing are determined by means of the Pennsylvania sorting system, the level of feed on the sieves is in line with the normative. The results of the production experiment on feeding dairy cows with Actisaf Sc 47, which has a probiotic effect, indicate better digestibility of the feed when the additive is introduced, the use of the drug contributes to: reducing ketone bodies in milk, the beneficial effect of improved feeding, by including yeast on the health of animals, improving the health of the udder, manifested in a decrease in somatic cells in milk. The milk yield with the use of the additive is increased, the milk protein is also increased, since its absorption in the rumen is improved. With the use of additives, the appetite and eatability of the feed improves, so in the group before feeding the probiotic, the percentage of feed residue on the feed table is higher than in the experiment. Dry matter intake is 4.32% higher when feeding supplements, while feed conversion is increased. Saving feed costs per 1 kg of milk is 0.97 rubles. Saving feed costs per year for a livestock of 1800 animals will amount to 523,800 rubles.
Enterosorbent based on montmorillonite as a promising tool in the treatment and prevention of intestinal disorders in pigs
Authors: Zuev Nikolay , Bukhanov Vladimir , Kuzubova Elena , Krut Ulyana , Shaydorova Galina , Radchenko Alexandra , Oleinikova Irina
Published: April 2021

The article discusses the treatment and prevention of feed toxicosis of pigs. A composition based on montmorillonite-containing minerals is considered as a promising enterosorbent in combination with the drug vievitin in the treatment of pig dysentery. Studies have shown that the complex use of vievitin with a sorbent by giving individually in 100 ml of drinking water at doses of 5.6 (second group) and 11.1 (third group) mg/kg body weight for vievitin and 400 mg/kg body weight bodies for the sorbent provided a high therapeutic effect in the treatment of piglets suffering from dysentery. Recovery, respectively, was 90.8 and 93.8%.
Instrumental diagnostic methods applied for orchiectomy in cockerels
Authors: Shambazova Svetlana
Published: April 2021

Any common surgical procedure, including orchiectomy in cockerels, requires perfect knowledge in topography and syntopy of the organ the surgery is performed on. This also implies acquiring the necessary information via the application of a number of instrumental methods such as diagnostic roentgenography and diagnostic sonography. Both methods have positive (intravital, painless and quick procedure) as well as negative (possible flaws in diagnostics due to age peculiarities) aspects.
Bovhyaluronidaze azoximer as an antimicrobial alternative in companion animals
Authors: Nazarova Anna , Semenov Boris , Kozitcyna Anna , Guseva Veronika , Kuznetsova Tatiana , Videnin Vladimir
Published: April 2021

Antimicrobial resistance formation in various bacteria is a serious biosafety threat. In this regard, the important issue in medical and veterinary fields is not only the rational use of antibacterial drugs, but also the search for ways to significantly reduce the need for antibiotics. Three studies designed to research into these challenges are described. The results indicated that (1) the bacteriuria presences in 62.4 +/-4.1% of urine samples obtained from companion animals (the microflora count in urine samples is estimated from ’++’ to ’Entire Field-of-View’); (2) 16.3 +/-4.0% of samples from companion animals showed bacteria with low antibiotics sensitivity, and 8.1 +/-3.0% of samples contained bacteria resistant to 30 antibiotics included in the susceptibility test; (3) the Bovhyaluronidaze azoximer reduce antimicrobial therapy duration statistically significant (p=0.0089). The studies were conducted at the facilities of St. Petersburg State University of Veterinary Medicine and Bars veterinary clinic chain in St. Petersburg, Russia. A randomized clinical trial of Bovhyaluronidaze azoximer effect on course of disease and treatment duration of acute and chronic prostatitis and urocystitis, including complicated by urolithiasis, was conducted in 54 dogs. Animals were randomly assigned to intervention (n=34) and control (n=20) groups. Animals of both groups received the antimicrobial therapy. Interventional group patients additionally received Bovhyaluronidaze azoximer in the form of rectal suppositories. The antimicrobial therapy mean duration in intervention group animals took 14.88 +/-4.98 days, in control group animals — 18.65 +/-5.40 days. The study findings imply that bacteriuria is widely prevalent in companion animals and antimicrobial resistance is increasing issue in veterinary medicine. Bovhyaluronidaze azoximer contributes to microcirculation restore and increases the bioavailability of antibacterial drugs at the site of infection. This makes its relevant for use in the complex treatment for septic and inflammatory processes. This allows to reduce the antimicrobial course duration (and completely decline antibiotic therapy in some cases) and prevent the formation of chronic inflammation and infection sites.
Analysis of 5G Non-Orthogonal Technology Application on Smart Grid
Authors: Liu Gang , Lu Huixian , Jin Mingsong , Yu Peng
Published: April 2021

Fifth generation (5G) wireless communication networks are being deployed worldwide at present, which not only enhances transmission ability with wide bandwidth for wireless mobile communication, but also enables 5G to promote a new digital, network and intelligence for all industry. Power communication has unique requirement and feature for itself, and with more and more power and other energy terminal devices need to access network, the current air access technology is difficult to satisfy the requirements. The 5G had carried out many key technology researches, including air interface and network technology, which establish solid basement for 5G standard and 5G+industry application. The article focuses on 5G Non-Orthogonal Multiple-Access (NOMA) technology, especially PDMA, and illustrates technology application scheme with power collection requirement as an example. It can be seen that NOMA can enhance network capability greatly for power communication, and improve transmission cover ability.
Generation Revenue Regulation and Incentive Contract Design in Electricity Market
Authors: Chen Baike , Rong Yuxia , Jing Zhaoxia
Published: April 2021

In order to curb market power, encourage investment and redistribute welfare, revenue regulation should be carried out in electricity market. The incentive contract represented by the Contract for Difference is a kind of regulation. This paper proposes a Government Authorized Contract based on Revenue Estimation Method (REM) from the perspective of regulating generation revenue. First, the principle and design of the Vesting Contract in Singapore electricity market is employed, analyzing its limitations in regulation. Then, the incentive contract based on REM is presented in four steps. Finally, the IEEE30 node classic system is adopted to demonstrate the proposed model, showing that it can promote generators to bid rationally.
Research on inertial response control technology of high voltage direct hanging energy storage system
Authors: Yan Huaidong , Li Haoyuan , Cai Lihua , Hu Anping , Liu Zhao
Published: April 2021

The high voltage direct hanging energy storage system can effectively solve the problems of fluctuation and intermittence caused by environmental factors, and improve the ability of power system to absorb new energy. By controlling the energy storage, the new energy station has certain inertia and damping characteristics, so that the new energy power station can be connected to the grid friendlier. Starting from the time scale division method of inertial response control, this paper studies the energy demand of inertial response of large-scale new energy power station in different time scales, and gives the inertial response control strategy under different time scales. The model of high voltage direct hanging energy storage system is established, and the inertia response characteristics control technology is verified.
Research on power prediction of photovoltaic power station based on similar hour and LM-BP neural network
Authors: Zhang Qiang , Liu Gang , Wei Xiangzhong
Published: April 2021

Aiming to solve the problem of low precision of traditional photovoltaic power forecast method under abrupt weather conditions. In this paper, a high-precision photovoltaic power prediction method based on similarity time and LM-BP neural network is proposed. Firstly, the factors affecting the output power of photovoltaic power station are analyzed, and the short-term output power model of photovoltaic power station is established based on similar day and LM-BP neural network. Then, from the perspective of model training efficiency and prediction accuracy, the deficiencies in the short-term power prediction of photovoltaic power stations based on similar days and LM-BP algorithm are analyzed. Secondly, the prediction model of LM-BP neural network based on similar hours is established. Finally, Jiaxing photovoltaic power station is taken as an example for simulation verification. The simulation results show that the proposed method has high accuracy in predicting photovoltaic power under abrupt weather conditions.
Front-end Solar Temperature And Humidity Control System
Authors: Dai Haocheng
Published: April 2021

Solid dehumidification is one of the important components of the dehumidification air-conditioning system. As an important method of solid dehumidification, the dehumidification performance and regeneration performance of fixed-bed dehumidification have an important impact on the operation and energy saving of the dehumidification air-conditioning system. In view of the high air temperature and high humidity in South China, our design organically combines dehumidification fixed beds, semiconductor refrigeration devices, foam ceramic insulation panels and double-glazed windows. We have designed a photovoltaic-driven modular solar temperature regulating and dehumidifying purification wall suitable for building dehumidification. The dehumidification window can use daytime solar radiation to regenerate the dehumidification fixed bed after absorbing moisture, reducing the energy consumption of regeneration. At the same time, the design can also use semiconductor refrigeration devices to adjust the temperature and humidity of the window inlet air to improve the window's dehumidification and regeneration performance. We tested and studied the dehumidification and regeneration performance of the device under different working conditions through experimental tests, which provided a basis for the engineering application and theoretical analysis of the device.
Image processing based on the detection of external defects of fan tower Weld
Authors: Wu Ren , Sun Yuan
Published: April 2021

With the continuous development of wind power generation technology and the continuous increase in the demand for electric energy, the height of the fan tower is more and more demanding. It is very important to detect the weld produced in the welding process of fan tower. In this paper, an algorithm for weld defect detection based on traditional image processing and convolutional neural network is proposed. Firstly, the traditional image processing algorithm is used to gray the weld image collected by industrial camera. Then, the gray image of welding seam is enhanced to improve the visual effect and clear the image, which is convenient for further processing and analysis of the image by computer. Finally, the image is used as the input of the trained convolution neural network to judge whether there are defects outside the weld.
Optimized Design of Precision EDM Machine Tool based on CAE Simulation and Modal Testing Technology
Authors: Liu Jianyong , Cai Yanhua , Zhang Haifeng , Ding Liantong
Published: April 2021

For precision EDM equipment, in addition to the static stiffness of the body of the machine, the dynamic characteristics of the body and the ambient temperature are also the key factors that affect the machining accuracy of the workpieces. In this paper, through the modal simulation analysis of the machine tool that with the sheet metal shell, the weak points of the EDM machine tool are determined. Through thermal stress simulation analysis, the thermal deformation law of the workpieces mounting table is determined, and a solution to reduce thermal deformation is proposed. Through machine tool ODS (operating deflection shapes) test and analysis, the weak links of the machine tool's body in actual processing are determined. Through the above optimization analysis, the foundation has been laid for improving the dynamic and static accuracy of the precision machine tool. The research method in this paper makes up for the deficiency of the machine tool design method based on static stiffness.
Differential Selective Etching of Functional Groups Strategy for Preparation of Organic Hollow Porous Silica
Authors: Li Jie , Zhang Jia , Wen ZhuoQiong , Yu Cui , Li XiaoPeng
Published: April 2021

In this study, different structural of organic hollow porous silica were prepared based on differential selective etching of functional groups strategy, using ammonia as catalyst, cetyltrimethylammonium bromide (CTAB) as pore-forming agent and emulsifier, cyano silica (CN-SiO2) or vinyl silica (V-SiO2) formed by hydrolysis condensation of 2-cyanoethyl triethoxysilane (CTES) or vinyl triethoxysilane (VTES) were used as cores, NH-SiO2 prepared by 3-aminopropyl triethoxysilane (APTES), SH-SiO2 prepared by mercaptopropyl trimethoxysilane (MPTMS) and UD-SiO2 prepared by urea-propyl triethoxysilane (UPTES) as shells, separately. The morphology and structure of the products were characterized by scanning electron microscopy(SEM) and transmission electron microscopy(TEM). The study results showed that CN-SiO2 as core was considered to be benefit for the preparation of organic hollow porous silica compared to V-SiO2 as core. In addition, core-shell structure obtained from CN-SiO2NH-SiO2 tend to be changed into hollow porous structure in alkaline condition on account of differential selective etching of functional groups strategy.
Rapid in situ determination of ClO2 in drinking water by improved solid DPD spectrophotometry
Authors: Zhang Qianqian , Jia Lijun , Hao Tianli , Zeng Ke
Published: April 2021

This research aims to realize the rapid detection of ClO2 content in drinking water by adopting improved solid DPD. This method is fast and convenient with low cost and less waste liquid. The results show that this method has good precision and sensitivity. The linear correlation coefficients of the cubic regression equation were all greater than 0.999. The detection limit of the method was 0.002mg/L ClO2. The relative standard deviations (RSD) of seven parallel tests were between 1.37% and 8.87%, and the relative errors were small. The recovery rate was 96.67~110%. The method could be used for the direct determination of water samples with a mass concentration of 0.02mg/L~2.00mg/L in drinking water after ClO2 disinfection.
Sequence component direction element based on power frequency variation
Authors: Liangzhi Sun , Kaili Jia , Pi Jia , Lixiao Jiang , Zijian Chen
Published: April 2021

Unlike the relatively stable network structure of the transmission and distribution network, under the new distribution network, resulting in errors in the impedance tuning of the fault directional element, misjudgment of the fault directional element, and a decrease in sensitivity. For this reason, this paper proposes a sequence component adaptive fault directional element based on power frequency variation. The sequence impedance amplitude is calculated through the measured values of the voltage sequence component and the current sequence component of the relay location. Then the phase angle of the setting impedance is determined according to various sequence components in the system. It improves the problem that the setting impedance of power frequency distance directional element is greatly affected by the amplitude and phase angle fluctuation of distribution system impedance and line impedance. The reliability and stability of the sequence component adaptive fault directional element based on the power fresquency variation are verified by Matlab simulation.
Non-intrusive load decomposition model based on Group Bayesian optimization and post-processing
Authors: Zhukui Tan , Bin Liu , Qiuyan Zhang , Chao Ding , Houpeng Hu
Published: April 2021

Non-intrusive load decomposition can decompose the power consumption of a single appliance from the household bus data, which is of great significance for users to adjust their own power consumption strategy. In order to solve the problem of large amount of computation in hyperparameter optimization of load decomposition model based on deep residual network, a Group Bayesian optimization method is proposed. This method can obtain better hyperparameter combination with less computational cost. In addition, in order to solve the problem of irrelevant activation of the model decomposition results, an improved post-processing method is proposed to improve the comprehensive performance of the model. Finally, the public data set REFIT is used to verify the proposed method, and the results show that the proposed method has a low decomposition error.
Research on Cooperative Communication Technology to Improve Capacity and Reliability of Integrated Energy System
Authors: Liu Gang , Lu Huixian
Published: April 2021

The integrated energy system makes full use of renewable resources such as local photovoltaics, fully considers the difference and complementarity of load types in the region, and realizes the efficient, economic and clean utilization of regional energy from the dimensions of time and space. The existing communication system of the integrated energy system has become a constraint on business development. First, the communication rate is low and the system capacity is limited. After the terminal collects various energy information, a large amount of data needs to be uploaded, which puts huge pressure on the communication bandwidth. The second is poor reliability and high operation and maintenance costs. The current communication technology is single, equipment and networking costs are high. Aiming at the abovementioned pain points, an opportunistic relay cooperation technology and scheme based on signaling measurement is proposed. Theoretical analysis and simulation results show that the above scheme can improve the performance of the cooperative diversity system while reducing conflicts.
Analysis and Research on Flow Characteristics of Hot Water Pipeline System
Authors: Yingzhe Hou , Hao Wu , Xiaozhe Yan , Haoqiang Zhu , Haitao Gao , Yiming Hu , Qiguan Cui , Jinying Xiong , Longyu Zhou
Published: April 2021

Based on the CFD numerical simulation method, a pipe model was established to study the internal flow characteristics of two different specifications of hot water pipe system, and the related information of the flow field was obtained, such as the internal pressure, flow velocity and flow rate. The results showed that the smoother the pipeline transition was, the smaller the velocity uniformity coefficient would be, and the higher flow field uniformity means the smaller pressure and velocity fluctuations. Therefore, the pipeline vibration will be smaller, and the flow characteristics are greatly improved.
Study on the evaluation method and influencing factors of fracture conductivity of hydraulic fracturing support in shale reservoir
Authors: Shun-li Yin , Tian-lin Zhuang , Li-yong Yang , Yun-peng Jia , Xue-wei Liu , Yu Liu , Tao Zhao
Published: April 2021

The conductivity of supporting fractures is an important parameter to evaluate the hydraulic fracturing effect of shale reservoirs, and its size is affected by many factors. In this paper, the proppant is optimized and evaluated on the basis of real rock slab simulation and actual construction proppant test. The laboratory experimental study on the influence of proppant type, sand concentration, proppant embedding and fracturing fluid residue on propping fracture conductivity is carried out, the results show that the average conductivity of 40 / 70 mesh proppant is about 7.15d · cm at 5kg / m2 sand concentration under the condition of reservoir closure pressure of about 50MPa, which can basically meet the requirements of main fracture conductivity of Kong 2 shale reservoir in Dagang Oilfield; the damage of guar gum fracturing fluid and proppant embedment are two important factors that cause the great decline of conductivity of rock slab, and the damage of guar gum fracturing fluid has a great influence on the conductivity, reaching about 50%; the stronger the mud is (the higher the clay content is), the greater the embedment degree of proppant is, and the greater the loss of conductivity is; for the same lithology, the proppant particle size has little damage to the conductivity, and the sand concentration has a greater impact on the conductivity. The larger the sand concentration is, the smaller the loss of the conductivity is.
Investment Prospect and Risk Analysis of Energy and Power Sector in Greece
Authors: Wenjing Ruan , Xinxin Feng , Hanxiong Xiao
Published: April 2021

Greece’s superior location advantages make it a key gateway for global energy enterprises to open the European market. At present, the consolidation of energy security in Greece provides investment opportunities for Chinese energy and power companies. However, it also faces risks such as the strengthening of the EU’s foreign investment review. This paper proposes that policy should be further strengthened at the national level, in order to guide domestic energy. At the same time, the enterprises must improve investment strategies and strengthen the construction of transnational operation capacity.
Research on Decision Methods for Technical Solutions Based on Grey-correlation degree to Vapor Recovery of Refined Oil Terminals
Authors: Jia Yuanming , Zhou Yiying , Deng Hongmei , li Jing
Published: April 2021

In the process of decision on technical solution to vapor recovery of refined oil terminals, the grey-correlation analysis (GCA) is introduced to optimise technical solutions by building a multi-target decision model and using the sequencing of weighted grey-correlation degree (GCD) of evaluation solution as judgment criteria, to determine the priorities of solutions, and the effectiveness of the decision method is verified by a practical example.
Analysis of the adiabatic process by using the thermodynamic property diagram of water vapor
Authors: Yarong Wang , Peirong Wang
Published: April 2021

In the steam power plant, the working medium used for energy transformation is water vapor. The thermodynamic properties of water vapor are usually obtained by using water vapor tables and charts. Adiabatic process of water vapor is widespread in engineering applications. The adiabatic process is realized without heat addition or rejection and the entropy of the working medium during a reversible adiabatic process remains constant. During an adiabatic expansion process, superheated steam turns into saturated vapor , and further into wet vapor, the pressure and the temperature of the steam decreases. The entropy during a irreversible adiabatic process increases. In general, when analyzing the thermodynamic process of water vapor, we first determine the state parameters by using charts and tables, and then make relevant calculations according to the first law of thermodynamics.
Patientin mit Schwangerschaft, Borderline-Organisation und schwerer Polytoxikomanie
Authors: Brokatzky Stefan
Published: April 2021

Zielsetzung Ziel dieser Arbeit war es, die Komplexität von Schwangerschaft und Sucht durch ein Fallbeispiel einer Patientin mit schwerer Polytoxikomanie, Borderline-Organisation sowie den Verlauf der Schwangerschaft und die frühe Phase nach der Geburt vorzustellen. Dabei ging es v. a. um die Frage, wie eine langfristige Behandlung mit einem mehrstufigen, multiprofessionellen und multimodalen Setting aussehen könnte. Die Arbeit zeigt zudem Konflikte an Schnittstellen auf und wie wichtig die Kommunikation innerhalb des Teams und fachübergreifend war.

Intervention Qualifizierte stationäre Entgiftungsbehandlung von Benzodiazepinen, Phenothiazin, Lyrica Venlafaxin und Reduktion von Methadon mit anschließender Umstellung auf Buprenorphin sowie ergänzender kombinierter ärztlicher, psychodynamischer Einzel- und Gruppentherapie und einem pflegerischen DBT-S Einzel- und Gruppensetting. Außerdem wurde schon während der Schwangerschaft zusätzlich zum stationären Behandlungsteam ein fächerübergreifendes Behandlungsteam aus Gynäkologen, Kinderärzten, Kinder- und Jugendpsychiatern sowie der Kinder- und Erwachsenenschutzbehörde (KESB, in Deutschland Jugendamt) zusammengestellt und schon zu Beginn wurde eine langfristige Behandlung mit stationärem, teilstationärem und ambulantem Intervall geplant.

Ergebnis Im Laufe der fast 3-jährigen Behandlung und 5 Jahre späteren katamnestischen Nachuntersuchung konnte zunächst unter 8 mg Buprenorphin eine Abstinenz von illegalen Substanzen erzielt werden. Im Verlauf sogar vollständige Abstinenz ohne Substitution. Dies konnte durch ein erneutes Interview und Drogenscreening im Jahr 2020 bestätigt werden. Außerdem konnte im Rahmen der fächerübergreifenden Arbeit ein stabiles soziales Umfeld und ein Wiedereinstieg ins Berufsleben erreicht werden.

Diskussion Trotz der anfänglich häufigen Rückfälle konnte durch den Erhalt der therapeutischen Beziehung (z. B. mittels Time-out auf die Akutstation, Verlängerung einer Wochenendbeurlaubung oder Neuverhandlung der Behandlungsvereinbarung) unter Fortsetzung der Einzelpsychotherapie und Bezugspflege mit Einbezug der Rückfälle, gegenseitiges Vertrauen und Wertschätzung geschaffen werden. Dafür war allerdings viel supervisorische Arbeit innerhalb des Teams, aber auch fächerübergreifend notwendig, da sich die extreme innerer Welt der Patientin häufig in unterschiedlicher Art und Weise im multiprofessionellen Team zeigte und dadurch zu Konflikten führte, die passager das Verlassen der Neutralität verlangten. Ferner waren für diese Art der Behandlung enorme Ressourcen notwendig sowohl zeitlich als auch personell.
White Sage (Salvia apiana)–a Ritual and Medicinal Plant of the Chaparral: Plant Characteristics in Comparison with Other Salvia Species
Authors: Krol Agata , Kokotkiewicz Adam , Luczkiewicz Maria
Published: April 2021

Salvia apiana, commonly known as white sage, is an aromatic evergreen subshrub of the chaparral, commonly found in coastal plains in California and Baja California. It has been traditionally used by the Chumash people as a ritual and medicinal plant and used as a calmative, a diuretic, and a remedy for the common cold. However, until recently, relatively little has been known about the composition and biological activity of white sage. Phytochemical studies on S. apiana revealed the presence of substantial amounts of essential oil, accompanied by a variety of triterpenes, C23 terpenoids, diterpenes, and flavonoids. Extracts of the plant have been shown to exhibit antioxidative, antimicrobial, and cytotoxic effects. The influence of white sage constituents on the nervous system, including GABA, opioid, and cannabinoid receptors, has also been documented. The review aimed to compile information on the taxonomy, botany, chemical composition, and biological activities of S. apiana. White sage was compared with other representatives of the genus in terms of chemical composition. The differences and similarities between S. apiana and other sage species were noted and discussed in the context of their therapeutic applications. Reports on ethnomedicinal uses of white sage were confronted with reports on chemistry, bioactivity, and bioavailability of S. apiana constituents. Finally, a critical assessment of the available data was made and perspectives for the use of white sage preparations in modern phytomedicine were discussed.
Design parameters for field-free spin–orbit torque switching of perpendicular synthetic antiferromagnets
Authors: Chen BingJin , Lourembam James , Chung Hong Jing , Lim Sze Ter
Published: April 2021

We report micromagnetic simulations of spin–orbit torque (SOT) induced magnetization switching of a ferromagnetic layer with perpendicular anisotropy in the absence of an external magnetic field. Field-free switching is achieved by antiferromagnetic interlayer exchange coupling (IEC) between two perpendicular ferromagnetic layers. At appropriate IEC values and an SOT current density exceeding the critical value (Jc), magnetization reversal can be achieved within sub-ns. The complete magnetization reversal of the synthetic antiferromagnetic free layer occurs upon removing the current pulse. Higher damping is preferred for the proposed switching scheme, as Jc decreases with the increase of damping. Remarkably, we also found that Jc has a parabolic dependence on the nanomagnet's diameter, with the vertex occurring at 90 nm.
Polarization switching in Bi0.8La0.2FeO3 films with ferroelectric/semiconductor heterojunctions
Authors: Liu Lin , Lei Lin , Lu Xiaomei , Mei Fang , Zhou Min , Hu Xueli , Yan Shuo , Huang Fengzhen , Zhu Jinsong
Published: April 2021

Bi0.8La0.2FeO3 (BLFO) films are deposited directly on low-resistance Si (100) substrates by the pulsed laser deposition method. Compared with the typical hysteresis loops of ferroelectric films, those of the BLFO/Si samples, with almost horizontal upper and lower ends, severely shrink in the center part, and the coercive voltage is extremely small. A systematic analysis of the dielectric and ferroelectric characteristics reveals that a p–n junction forms between BLFO and Si, with oxygen vacancies accumulating near the interface. The polarization switching is accompanied by the change of the interface barrier and the migration of charged defects. This work provides a reference for the direct growth of ferroelectric films on silicon substrates and is of great significance for the development of the silicon-based electronic devices.
Carbon quantum dots by submerged arc discharge in water: Synthesis, characterization, and mechanism of formation
Authors: Chao-Mujica F. J. , Garcia-Hernández L. , Camacho-López S. , Camacho-López M. , Camacho-López M. A. , Reyes Contreras D. , Pérez-Rodríguez A. , Peña-Caravaca J. P. , Páez-Rodríguez A. , Darias-Gonzalez J. G. , Hernandez-Tabares L. , Arias de Fuentes O. , Prokhorov E. , Torres-Figueredo N. , Reguera E. , Desdin-García L. F.
Published: April 2021

Carbon quantum dots (CQDs) are novel nanostructures that have great potential as fluorescent markers due to their multi-fluorescence, down and up converted emission, resistance to photobleaching, and biocompatibility. Here, we report the synthesis of fluorescent CQDs by the submerged arc discharge in water method. We discuss the method's simplicity, natural phases’ separation, and scalability. The produced CQDs size distribution was in the range of 1–5 nm. High-resolution transmission electron microscopy images and their fast Fourier transformation allowed the analysis of the CQDs’ internal structure. The absorption and fluorescence spectra of the as-produced CQDs were analyzed. The UV-Vis spectrum shows a single band with a maximum located at 356 nm. The photoluminescence emission presents two consistent bands with maxima located in the ranges of 320–340 nm (band A) and 400–410 nm (band B). To these emission bands correspond two bands in the excitation spectra located at 275 nm (band A) and 285 nm (band B). The fluorescence quantum yield was assessed as ∼16% using Rhodamine 6G as reference. The capabilities of the produced CQDs as fluorescent markers for in vitro studies were also evaluated by setting them in contact with a cell culture of L929 murine fibroblasts. Control and CQD-treated cell cultures were visualized under a fluorescence microscope. Finally, the mechanism of formation of these nanostructures by top-down methods is discussed, and a general model of formation is proposed.
Quasi-objective coherent structure diagnostics from single trajectories
Authors: Haller George , Aksamit Nikolas , Encinas-Bartos Alex P.
Published: April 2021

We derive measures of local material stretching and rotation that are computable from individual trajectories without reliance on other trajectories or on an underlying velocity field. Both measures are quasi-objective: they approximate objective (i.e., observer-independent) coherence diagnostics in frames satisfying a certain condition. This condition requires the trajectory accelerations to dominate the angular acceleration induced by the spatial mean vorticity. We illustrate on examples how quasi-objective coherence diagnostics highlight elliptic and hyperbolic Lagrangian coherent structures even from very sparse trajectory data.
Wideband reflection wavelength tuning by bending of cholesteric liquid crystal elastomer films
Authors: Kishino Masayuki , Akamatsu Norihisa , Taguchi Ryo , Kubo Shoichi , Hisano Kyohei , Tsutsumi Osamu , Shishido Atsushi
Published: April 2021

Cholesteric liquid crystal elastomers (CLCEs), which exhibit selective reflection derived from a helical molecular structure, are receiving a great deal of attention because they deform largely due to the cross-linked polymer chains. Reflection wavelength of a CLCE film can be tuned by mechanical stretching that induces a change in the helical pitch. However, stretch-induced reflection wavelength tuning has some issues such as a large load required and a limited tuning range. In this paper, reflection wavelength of a CLCE film is tuned facilely and widely by bending. Outward and inward bendings cause blue and red shifts, respectively. Bending–buckling load required for the reflection tuning is much lower than stretching one, which is proved experimentally and theoretically. By considering the bending behavior of materials, we can impose large strain on a CLCE film and tune reflection wavelength over 300 nm, which is almost the whole region of visible light. This wideband reflection wavelength tuning by low-load bending leads to expanding applications of CLCEs.
Droplet ejection by electrowetting actuation
Authors: Vo Quoc , Tran Tuan
Published: April 2021

Fast contact-line motion of a droplet spreading on a solid substrate under the electrowetting effect generates strong capillary waves on the droplet's surface. The capillary waves may be strong enough to induce ejection of a satellite droplet from the primary one. In this study, we show that the size of the satellite droplet and the ejection time are not only dependent on the contact-line velocity, which directly relates to the applied voltage enabling the electrowetting effect, but are also affected by the ejection dynamics. We derive a theoretical model of the criteria for droplet ejection and experimentally verify the proposed criteria for wide ranges of viscosity, droplet size, and the applied voltage.
Growth defects in heteroepitaxial diamond
Authors: Lebedev Vadim , Engels Jan , Kustermann Jan , Weippert Jürgen , Cimalla Volker , Kirste Lutz , Giese Christian , Quellmalz Patricia , Graff Andreas , Meyer Frank , Höfer Markus , Sittinger Volker
Published: April 2021

In focus of this report are the mechanisms of formation, propagation, and interaction of growth defects in heteroepitaxial diamond films along with their impact on the optical emission properties of N- and Si-vacancy (NV and SiV) color centers. Here, we analyze and discuss the properties of incoherent grain boundaries (IGBs) and extended defects in a nitrogen- and boron-doped heterodiamond nucleated and grown on Ir(001) via bias-enhanced nucleation and chemical vapor deposition techniques. We show that the low-angle IGBs alter the structural and optical emission properties of NV and SiV complexes by subduing NV emission and supporting the formation of interstitial Si-vacancy complexes dominating in the faulted IGB regions. We also demonstrate that the IGB-confined threading dislocations are responsible for the vertical transport and incorporation of Si impurities in thick layers, leading to an enhanced SiV emission from the IGBs.