bluuebunny/crossref_metadata_2025 huggingface dataset:
An extremely tough and ionic conductive natural-polymer-based double network hydrogel
Authors: Sun Xingyue , Liang Yongzhi , Ye Lina , Liang Haiyi
Published: August 2021

A novel hydrogel composed of natural polymers exhibiting remarkable mechanical properties and conductivity is prepared by soaking a precursor hydrogel in salt solution, exploring a new pathway towards potential applications in biomedical engineering.
Photo-induced guest–host interactions produce chiral conglomerates accompanying grain boundaries in a smectic phase
Authors: Sasaki Hideaki , Abe Koudai , Sagisaka Masanobu , Yoshizawa Atsushi
Published: August 2021

The photo-inducedcis-isomer of an azobenzene trimer with odd-numbered spacers produces not only chiral conglomerates but also grain boundaries in a smectic phase of the mixture with a host liquid crystal.
Bionic optical physical unclonable functions for authentication and encryption
Authors: Wan Yongbiao , Wang Pidong , Huang Feng , Yuan Jun , Li Dong , Chen Kun , Kang Jianbin , Li Qian , Zhang Taiping , Sun Song , Qiu Zhiguang , Yao Yao
Published: August 2021

Inspired by biological diversity and uniqueness, the concept of bionic optical physical unclonable functions (PUFs) is proposed. Production is simple, low-cost, green and environmentally friendly. The extracted binary codes from bionic PUFs are random, unclonable, and robust enough for applications in entity authentication and encrypted communication.
Ketone–enol tautomerism, polymorphism, mechanofluorochromism and solid-state acidochromism of isoquinolinone–arylidenehydrazine derivatives
Authors: Wang Dan , Zhang Xinyu , Han Xiangdong , Zhou Yunbing , Lei Yunxiang , Gao Wenxia , Liu Miaochang , Huang Xiaobo , Wu Huayue
Published: August 2021

Four isoquinolinone–arylidenehydrazine derivatives with keto–enol tautomerism exhibit amazing multifunctional properties.
Cross-sections of relativistic quantum-mechanical versus those of classical magnetic resonant scattering
Authors: Loudas N. A. , Kylafis N. D. , Trümper J. E.
Published: August 2021

Context. Radiative transfer calculations in strong (few ×1012 G) magnetic fields, which are observed in X-ray pulsars, require accurate differential cross-sections of resonant scattering. While such cross-sections exist, their application is cumbersome.

Aims. Here, we compare the classical (non-relativistic) with the quantum-mechanical (relativistic) resonant differential scattering cross-sections and offer a prescription for the use of the much simpler classical expressions with impressively accurate results.

Methods. We expanded the quantum-mechanical differential cross-sections and kept the terms up to the first order in ϵ ≡ E/mec2 and B ≡ ℬ/ℬcr, where E is the photon energy and ℬcr is the critical magnetic field. We recovered the classical differential cross-sections along with the terms that are due to spin flip, which is a pure quantum-mechanical phenomenon.

Results. When adding the spin-flip terms to the polarization-dependent classical differential cross-sections by hand, we find that they are in excellent agreement with the quantum mechanical ones for all energies near resonance and all angles. We plotted both of them and the agreement is impressive.

Conclusions. We give a prescription for the use of the classical differential cross-sections for radiative transfer calculations that guarantees accurate results.
A different look at featured motor learning models: comparison exam of Gallahue’s, Fitts and Posner’s and Ann Gentile’s motor learning models
Authors: Salehi Sayed Kavos , Tahmasebi Farshid , Talebrokni Fateme Sadat
Published: August 2021

Learning motor skills follows a predictable sequence and stages. The main purpose of this study is to examine Gallahue’s motor learning model and compare it with existing featured models. Until now, several different models have been proposed by several theorists to identify and describe stages of motor learning. Fitts, P.M., and Posner, M.I. (1967.Human performance. Belmont: Brooks/Cole Pub. Co.) proposed a three-stage model for motor skill learning based on the learner’s cognitive state during the learning continuum. Gentile (1972–1978) proposed a two-stage model based on the goals of the learner. Gallahue (1972–2012) presented a three-level model with several accompanying sub-stages. In the present study, these models were compared in order to identify the best model to assist learners and practitioners. Analytical examinations showed that Gallahue’s motor learning model incorporates elements from both Fitts and Posner and Gentile models, but also provides specific guidelines and actions for instructors and practitioners along the learning continuum. Therefore, it seems to be more comprehensive and coherent (logical connection or relevant) in terms of functionality than existing models and provides specific cues for maximizing learning and meet the learner’s needs at each stage of learning.
Clozapin in der Behandlung schizophrener Psychosen
Patientencharakteristika und antipsychotische Kombinationstherapien bei einem
Behandlungsjahrgang eines psychiatrischen
Versorgungskrankenhauses
Authors: Rentrop Michael , Huhn Maximilian , Schwerthöffer Dirk
Published: August 2021

Anliegen Clozapin zeigt in vielen Untersuchungen eine überlegene
Wirksamkeit gegenüber anderen Antipsychotika. Zur Verschreibungspraxis
von Clozapin und den Charakteristika der damit behandelten Patienten gibt es
bislang wenig systematisch erhobene Daten.

Methode Retrospektive Auswertung aller 392 Behandlungsverläufe von
stationär behandelten Patienten mit schizophrenen Psychosen eines
Jahres. Detaillierte Analyse der mit Clozapin behandelten Patienten
einschließlich der Dosierungen und der zusätzlichen
Medikation.

Ergebnis Patienten mit Clozapinbehandlung weisen eine höhere
Krankheitsschwere als Patienten ohne Clozapinbehandlung auf. Sie erhalten
häufiger pharmakologische Kombinationsbehandlungen, die den
gegenwärtigen Leitlinienempfehlungen teilweise erheblich
entgegenstehen.

Schlussfolgerung Die Ergebnisse unterstreichen die ausgeprägte
Krankheitsschwere von Patienten mit einer Clozapinbehandlung und belegen
Hinweise aus der Literatur auf die begrenzte Umsetzung von Leitlinien in die
Verschreibungspraxis. Die durchgeführte Untersuchung dient als
Pilotuntersuchung einer multizentrischen Studie zur Verschreibungspraxis von
Clozapin in psychiatrischen Kliniken unterschiedlicher Regionen.
Radiology Reporting Errors: Learning from Report Addenda
Authors: Patra Anurima , Premkumar Manthreshwar , Keshava Shyamkumar N. , Chandramohan Anuradha , Joseph Elizabeth , Gibikote Sridhar
Published: August 2021

Background The addition of new information to a completed radiology report in the form of an “addendum” conveys a variety of information, ranging from less significant typographical errors to serious omissions and misinterpretations. Understanding the reasons for errors and their clinical implications will lead to better clinical governance and radiology practice.

Aims This article assesses the common reasons which lead to addenda generation to completed reports and their clinical implications.

Subjects and Methods Retrospective study was conducted by reviewing addenda to computed tomography (CT), ultrasound, and magnetic resonance imaging reports between January 2018 to June 2018, to note the frequency and classification of report addenda.

Results Rate of addenda generation was 1.1% (n = 1,076) among the 97,003 approved cross-sectional radiology reports. Errors contributed to 71.2% (n = 767) of addenda, most commonly communication (29.3%, n = 316) and observational errors (20.8%, n = 224), and 28.7% were nonerrors aimed at providing additional clinically relevant information. Majority of the addenda (82.3%, n = 886) did not have a significant clinical impact. CT and ultrasound reports accounted for 36.9% (n = 398) and 35.2% (n = 379) share, respectively. A time gap of 1 to 7 days was noted for 46.8% (n = 504) addenda and 37.6% (n = 405) were issued in less than a day. Radiologists with more than 6-year experience created majority (1.5%, n = 456) of addenda. Those which were added to reports generated during emergency hours contributed to 23.2% (n = 250) of the addenda.

Conclusion The study has identified the prevalence of report addenda in a radiology practice involving picture archiving and communication system in a tertiary care center in India. The etiology included both errors and non-errors. Results of this audit were used to generate a checklist and put protocols that will help decrease serious radiology misses and common errors.
Quantum model considers the effect of laser wavelength, intensity, and DC bias on photoemission
Authors: Patrick Chris
Published: August 2021

Calculations demonstrate the importance of laser electron heating, which can increase the quantum efficiency of photoemission.
Mixing driven by transient buoyancy flows.II. Flow dynamics
Authors: Duval W. M. B. , Zhong H. , Batur C.
Published: August 2021

The chaotic advection of the interface between two miscible liquids inside a closed cavity, generated by a damped oscillatory buoyancy-driven (BD) regular flow field, is investigated experimentally for BD mixing. The Lagrangian history of interface motion, determined using the planar laser-induced fluorescence and the photographic full-field view method, is contrasted against the Eulerian flow field measured from particle image velocimetry. Chaotic advection stretches and folds the interface at an early stage to produce an asymmetric pairwise Rayleigh–Taylor (RT) morphology (RTM) structure from long wavelength RT instability and short-time Richtmyer–Meshkov instability and its fractal interface structure at a high impulsive-Reynolds number. The mechanism of folding, from global bifurcation of the flow field, caused by a hyperbolic point, served as an organizing center for multiple vortex interactions. The intermediate-stage kinematics of the RTM structure exhibits RT mixing and shows unfolding of the lamellar structure from the net effect of stretching, folding, and molecular diffusion prior to its breakdown; and it has a probabilistic outcome of exhibiting topological transitions through a breakup of the RTM structure in phase space from necking singularity and pinch-off, indicating sensitivity to the initial conditions. The effectiveness of mixing determined from mixing efficiency is contrasted against mechanical and lamellar models of mixing. The determination of topological entropy, from an approximate Gaussian distribution of the interface length stretch, yields time scale for information decay comparable to time scale for which a low-order horseshoe map emerges from flow, indicating local chaos of the interface. The late-stage breakdown of the RTM structure from internal and wall collision drives the interaction between advection and diffusion, which indicates that critical mixing time scales as the logarithmic of Peclet number, comparable to time-periodic sine flow and blinking vortex flow chaotic mapping models.
Studies of cavitation characteristics of inducers with different blade numbers
Authors: Zhai Lulu , Li Yifan , Cui Baoling , Guo Jia , Li Xiaodi , Zhu Zuchao
Published: August 2021

The cavitation characteristics and load distributions of the inducer have great influences on the vibration characteristics of the rotating system and the whole pump. In this paper, the numerical simulations of the flow field within different inducers were carried out based on the Shear Stress Transfer (SST) k–ω turbulence model combined with the hybrid cavitation model to investigate the effects of blade numbers on the internal flow and cavitation characteristics of the model inducers. The simulation results were compared with the experimental results obtained using a closed inducer performance test rig to verify the accuracy and applicability of the numerical simulation method. The comparisons show that the three-blade inducer has better cavitation performances than the two-blade one. The simulation results of the bubble and load distributions suggest that the cavitation at low flow rates within the two model inducers occurs mainly near the leading edge of the blade tip, but at the design flow rates or higher flow rates, the cavitation within the two-blade inducer occurs along the suction surfaces near the inlet and the cavitation within the three-blade inducer occurs mainly on the inlet suction surfaces near the blade root.
Model and simulation investigation of the whole process of high-current vacuum arc burning
Authors: Zhao Shuangwei , Zhao Lihua , Huang Xiaolong , Chen Weiwei , Ning Wenjun , Wang Lijun
Published: August 2021

With the development of the power industry and the increase in the capacity of power systems, vacuum switches have been developed rapidly. The distribution characteristics of the vacuum arc can reflect the working conditions of the vacuum switch. So, it is vital to understand the distribution characteristics in the vacuum arc burning process for understanding the interruption performance of vacuum switches. Based on the 3D magnetohydrodynamic model, we investigated the high-current vacuum arc burning process by modeling and numerical simulation. The research findings show a certain correspondence between the change in plasma parameters values and the change in arc current. The distribution of plasma parameters is uniform when the current is small. The distribution of plasma parameters in the first 1/4 cycle is more uniform than in the second 1/4 cycle. The evolution characteristics of the arc plasma parameters for interruption before the arc current maximum differ significantly from those for interruption after the arc current maximum and current maximum. The results of this study can provide a reference for the design and improvement of vacuum switches.
Natural variation identifies SNI1, the SMC5/6 component, as a modifier of meiotic crossover in
Arabidopsis
Authors: Zhu Longfei , Fernández-Jiménez Nadia , Szymanska-Lejman Maja , Pelé Alexandre , Underwood Charles J. , Serra Heïdi , Lambing Christophe , Dluzewska Julia , Bieluszewski Tomasz , Pradillo Mónica , Henderson Ian R. , Ziolkowski Piotr A.
Published: August 2021

Significance

Meiotic recombination plays a fundamental role in shaping genetic diversity in eukaryotes. Extensive variation in crossover rate exists between populations and species. The identity of modifier loci and their roles in genome evolution remain incompletely understood. We explored natural variation in
Arabidopsis
crossover and identified
SNI1
as the causal gene underlying a major modifier locus. To date, SNI1 had no known role in crossover. SNI1 is a component of the SMC5/6 complex that is closely related to cohesin and condensin.
Arabidopsis sni1
and other SMC5/6 mutants show similar effects on the interference-independent crossover pathway. Hence, our findings demonstrate that the SMC5/6 complex, which is known for its role in DNA damage repair, is also important for control of meiotic crossover.
Carbon dioxide as a line active agent: Its impact on line tension and nucleation rate
Authors: Bey Romain , Coasne Benoit , Picard Cyril
Published: August 2021

Significance

The thermodynamic stability of any three-phase system involves the free energy cost of the triple line where the three phases intersect. Despite its acknowledged impact in physics, chemistry, and biology, the line tension—analogous to the well-known concept of surface tension for interfaces—remains puzzling in many aspects. In particular, even if a consensus starts to emerge for liquid/vapor equilibrium of a pure substance on a solid surface, the case of fluid mixtures remains unexplored. Here, we show thatCO2acts as a line active agent by altering significantly the line tension of water near solid surfaces. Beyond fundamental aspects, such gas-induced line tension modifications could be used in numerous practical applications where multiphase flows are involved.
Moving Dirac nodes by chemical substitution
Authors: Nilforoushan Niloufar , Casula Michele , Amaricci Adriano , Caputo Marco , Caillaux Jonathan , Khalil Lama , Papalazarou Evangelos , Simon Pascal , Perfetti Luca , Vobornik Ivana , Das Pranab Kumar , Fujii Jun , Barinov Alexei , Santos-Cottin David , Klein Yannick , Fabrizio Michele , Gauzzi Andrea , Marsi Marino
Published: August 2021

Significance

The on-demand control of topological properties with readily modifiable parameters is a fundamental step toward the design of novel electronic and spintronic devices. Here, we show that this goal can be achieved in the correlated system

BaCo

1
−
x

Ni

x

S

2

, where we succeeded in significantly changing the reciprocal space position and shape of Dirac nodes by chemically substituting Ni with Co. We prove that the tunability of the Dirac states is realized by varying the electron-correlation strength and the charge-transfer gap, both sensitive to the substitution level,

x

. Based on our finding, a class of late-transition metal compounds can be established as prototypical for engineering highly tunable Dirac materials.
Prediction in bilingual children
Authors: Karaca Figen , Brouwer Susanne , Unsworth Sharon , Huettig Falk
Published: August 2021

A wealth of studies has shown that more proficient monolingual speakers are better at predicting upcoming information during language comprehension. Similarly, prediction skills of adult second language (L2) speakers in their L2 have also been argued to be modulated by their L2 proficiency. How exactly language proficiency and prediction are linked, however, is yet to be systematically investigated. One group of language users which has the potential to provide invaluable insights into this link is bilingual children. In this paper, we compare bilingual children’s prediction skills with those of monolingual children and adult L2 speakers, and show how investigating bilingual children’s prediction skills may contribute to our understanding of how predictive processing works.
Classification of error-related potentials evoked during stroke rehabilitation training
Authors: Kumar Akshay , Pirogova Elena , Mahmoud Seedahmed S , Fang Qiang
Published: August 2021

Objective. Error-related potentials (ErrPs) are elicited in the human brain following an error’s perception. Recently, ErrPs have been observed in a novel task situation, i.e. when stroke patients perform upper-limb rehabilitation exercises. These ErrPs can be used to develop assist-as-needed (AAN) robotic stroke rehabilitation systems. However, to date, there is no reported research on assessing the feasibility of using the ErrPs to implement the AAN approach. Hence, in this study, we evaluated and compared the single-trial classification of novel ErrPs using various classical machine learning and deep learning approaches. Approach. Electroencephalogram data of 13 stroke patients recorded while performing an upper-limb physical rehabilitation exercise were used. Two classification approaches, one combining the xDAWN spatial filtering and support vector machines, and the other using a convolutional neural network-based double transfer learning, were utilized. Main results. Results showed that the ErrPs could be detected with a mean area under the receiver operating characteristics curve of 0.838, and a mean accuracy of 0.842, 0.257 above the chance level (p < 0.05), for a within-subject classification. The results indicated the feasibility of using ErrP signals in real-time AAN robot therapy with evidence from the conducted latency analysis, cross-subject classification, and three-class asynchronous classification. Significance. The findings presented support our proposed approach of using ErrPs as a measure to trigger and/or modulate as required the robotic assistance in a real-time human-in-the-loop robotic stroke rehabilitation system.
Mechanical vibration affects Gatling weapon shooting accuracy
Authors: Xu Jian , Song Lanwei , Yang Zhen
Published: August 2021

To using the Gatling fire mode to the fire accuracy, the Gatling gun fire mode was researched and it was found that the advantage of even Gatling gun. The firing mode of the Gatling weapon is clearly a turn round, several tubes firing several rounds. There are drawbacks that the faster the launch, the more the gun body tubes group shift in the direction, and resulting in the weapon missing a lot from the shooting target. There was no choice but to make compensatory moves on the firepower system. this paper the launch even mode proposed is still rotating, but it is indeed the upper and lower parts of the projectile. And the pipes are divided into two groups, and one group moves from the left, the top is in the launch state; and the other group enters from the right side, and the bottom is in the launch state. the horizontal displacement in the barrel mouth is 0.0028142m but the new methods is 1.168e-6m, and While 2000m the Gatling old scheme has 80m layout and the new Gatling gun has only 5m. The comparison with the single-tube weapon, and the even tube (4,6,8,10) has an advantage over odd tube (3,5,7,9), and it is more convenient to supply the bullet left and right or up and down.
Effect of characteristics of non-metallic inclusions on fatigue life of high-speed rail bearings based on multiple linear regression
Authors: Guo Xiaohan , Zhang Gang , Ma Canyang , Zhang Zhenqiang
Published: August 2021

In the process of smelting and manufacturing, bearing steel inevitably have defects such as non-metallic inclusions. Moreover, inclusion geometry (type, quantity, size, distribution, and shape) has a significant effect on the fatigue failure of bearing steel. In order to study effect extent of the size and distribution of inclusion on the fatigue life of bearings, this paper uses the test high-speed rail bearings LY-Z028 to research and analysis. The micro-model of contact between single inclusion and the matrix is established, and then performs ANSYS simulation on stress concentration which caused by size of single inclusion and relative surface depth. Further, multiple linear regression method is used to compare the effect extent of these two factors on the fatigue life. The results show that size of single inclusion has a greater impact on the fatigue life than relative surface depth, which can provide an effective reference for smelting and production requirements.
An improved target detection algorithm based on EfficientNet
Authors: Wu Tao , Zhu Hongjin , Fan Honghui , Zhou Hongyan
Published: August 2021

In order to improve the detection accuracy for small-scale targets in complex scenes, an improved target detection algorithm based on EfficientNet is proposed. Firstly, the EfficientNet network is used to optimize the DarkNet53 feature extraction network. Compressing the standard convolution with the depthwise separable convolution, and increasing the depth of the neural network with the residual network that can effectively achieve feature extraction, reduce the number of parameters and improve the detection speed. Secondly, a feature pyramid network is used to design four scales of features for multi-scale feature extraction, which improves the detection of small targets. The experimental results show that the YOLOv3 target detection algorithm improves the detection accuracy by 4.98% compared to the original algorithm on VOC dataset, which improves the detection accuracy and ensures real-time detection for small targets.
Fault simulation and forecast of helical cylindrical gear of reducer based on ADAMS
Authors: Tang Yerong , Liu Qingyun , Zhu Qing
Published: August 2021

Aiming at the problems that the dynamic speed and meshing force of the helical cylindrical gear of the reducer are difficult to actually measure and the test cost is high, the helical cylindrical gear transmission system of a crane reducer is used as the research object, and the 3D modeling software Solid Works is used to establish the assembly model of the gear transmission system, import the dynamic simulation software ADAMS to establish simulation model, and perform simulation analysis on it. The simulation results show that the gear speed is stable after acceleration, which is basically close to the theoretical calculation value; meshing at different multiples the gear meshing force amplitude is different at different frequencies. As the frequency multiplier increases, the amplitude shows a downward trend. Finally, Ensemble Empirical Mode Decomposition (EEMD) sample entropy and Extreme Learning Machine (ELM) are used for fault prediction to verify the effectiveness of this method. The above can provide a certain reference basis for the condition monitoring and fault prediction of the gearbox of metallurgical cranes, so as to ensure the safe operation of the crane.
Classification of underground engineering surrounding rock based on Gaussian cloud model
Authors: Teng Yun , Zhou Keping , Li Zhichao
Published: August 2021

Based on the Gaussian cloud model, an integrative evaluation method for the stability classification of surrounding rock was presented. Selecting five factors, i.e. rock quality designation, uniaxial compressive strengthen, integrality coefficient, strengthen coefficient of structural plane and seepage measurement of groundwater to be the evaluation indicators. According to the Gaussian cloud model and the information entropy theory, the data were normalized and the comprehensive certainty was calculated, then a Gaussian cloud model was obtained to classify the stability classification of surrounding rock. 14 samples of the first stage project in Guangzhou pump accumulator electricity station and 16 samples produced by the interpolation method were taken as the training samples. 12 samples of the second stage project were selected to verify the model. Compared with the artificial neural network (ANN) method and support vector machine (SVM) method, the results show the gauss cloud method has excellent performance and high prediction accuracy, and the method is of practical value, can be applied to evaluate the stability of surrounding rock in underground engineering.
Optimization analysis of dynamic characteristics of a certain car seat with rigid-flexible coupling
Authors: Fu Shaohua , Wang Shufen , Yang Duo , Kang Mengnan
Published: August 2021

Aiming at the problem of the dynamic comfort of a certain car driver’s seat, from the aspect of selecting the dynamic parameters of the seat cushion, a simulation idea for studying the dynamic comfort of the seat has been proposed. The rigid-flexible coupling dynamics model of the human body and the seat is established through the flexible processing of the seat cushion. ADAMS has been used to analyze the dynamics of the model and compare the changes in the human comfort level when the dynamic parameters of the seat cushion are changed. The optimal range for selecting its dynamic parameters has been obtained. ADAMS/Car has been used to establish a virtual model of the vehicle system, and the dynamic comfort of the model has been analyzed to obtain the human body acceleration power spectral density curve. The results indicate that the optimal selection ranges for seat cushion stiffness and damping are 14∼20N/mm and 0.3∼0.6Ns/mm, respectively. In this range, the resonance frequency of the car seat is lower than the most sensitive frequency of the human body. Use the human comfort evaluation method to verify that the result is reliable, it provides a direction for the subsequent design.
Structural dynamic response of a locomotive hydraulic damper with welding imperfections
Authors: Wang Wenlin , Zhou Zirong , Huang Bao , Du Jianming
Published: August 2021

Railway vehicle hydraulic dampers are usually subject to premature structural failures, so it is meaningful to investigate the dynamic response of its welded main structure. FEA modelling of the welded rod-and-attachment assembly with imperfections of a Chinese electric locomotive axle-box hydraulic damper is performed, and load spectra of the axle-box hydraulic damper both under nominal and actual in-service conditions are obtained. Structural dynamics response analysis of the welded rod-and-attachment assembly of the damper is then conducted by using the FEA model and load spectra, and demonstrates that all of the maximum dynamic stresses have increased by 40% or so when using the actual in-service load spectra regardless of the weld joint condition, if the weld joint is with imperfection of misalignment of rod and attachment, the maximum dynamic stress has increased by 41.46%. Therefore, railway hydraulic dampers are usually subject to actual in-service load spectra instead of the nominal load spectra used in the design process, if the damper also has got welding imperfections, the damper would be readily subject to premature failures, this is why many current railway vehicle hydraulic dampers are still subject to premature failures despite with ‘perfect’ designs. The FEA model, the structural dynamic response analysis approach and results obtained in this work would be instructive in improving damper structure design, welding quality control and inspection.
Analysis of structure and mixing characteristics of a double barrel with differential velocity based on theory and discrete element simulation
Authors: Zhao Lingying , Ye Min , Gu Hairong , Wang Qingxian , Jiao Shengjie
Published: August 2021

The double barrel (DB) is the essential functional part of continuous asphalt mixing equipment, which affects the mixing uniformity of asphalt mixture. To improve the mixing uniformity of the mixture, a double barrel with differential velocity (DBDV) was proposed. The structure of DBDV and its influence on the mixing uniformity of the mixture were described. The current double barrel is divided into single horizontal shaft DB and double horizontal shaft DBDV. The discrete element simulation is used to compare the mixing uniformity of two kinds of DB. The results show that the mixing uniformity of double horizontal shaft DBDV is better than that of the single horizontal shaft DB, proving the correctness and rationality of the above analysis.
Design on non-stop transportation plugging device for subsea pipeline
Authors: Jiang Hao , Meng Lingzhi , Niu Xuebin , Zhang Lijun , Wang Longting , Li Dawei , Xu Wenkai , Zhang Binghui
Published: August 2021

The process of plugging with pressure outside the subsea pipeline is cumbersome. The common technology cannot transport oil and gas during the maintenance process, and a new type of subsea pipeline non-stop transportation plugging technology is proposed. In this paper, an oil and gas pipeline with a diameter of 324mm and a pressure of 3MPa is taken as the research object for overall design and feasibility analysis. The anchoring and sealing performance of the packer is calculated, checked and analyzed using the element method. The results indicated that the plugging device can meet the plugging requirements of non-stop transportation of subsea oil and gas pipelines in maintenance.
Application of wireline intelligent separate-layer water injection technology in Huabei Oilfield
Authors: Zhang Xu , Zhu Ruibin , Li Gaofeng , Jiang Yan , Xiong Wei , Zhao Fei , Wang Jianning , Lin Chunqing , Liu Qilun , Li Ran
Published: August 2021

In order to increase the separate-layer water injection effect of heterogeneous sandstone reservoir in Huabei Oilfield, improve the qualified rate of water injection and reduce the workload of sealing, testing and adjustment, the wireline intelligent separate-layer water injection technology was used. This technology can remotely read the downhole water injection flow, temperature, pressure which was collected by the intelligent water distributor in real time on the ground. And it also can adjust the nozzle size of the intelligent water distributor in real time to make the sealing test and adjustment work easily. Up to now, there are 180 wells were implemented by wireline intelligent separate-layer water injection technology in Huabei Oilfield. This paper introduces the characteristics, key tools and construction auxiliary devices of the wireline intelligent separate-layer water injection technology. And it also evaluates the effect of the 33 wells which were implemented in the past year. The effective probability of 33 well groups is 92%, and that of corresponding wells is 83.8%. The cumulative oil increment is more than 277830 bbl and it has saved the cost of sealing test and adjustment work by 33.12 million yuan. The effect is remarkable on cost decreasing and benefit increasing. The wireline intelligent separate-layer water injection technology can improve the water flooding oil recovery effectively and it is helpful to the accurate development of oil reservoir. This technology has great value of application and popularization.
Design of shock-resistant miniaturized shipborne radar confluence ring
Authors: Dai Ye , Lin Fangmi , Zhu Zenghui , Chen Yang
Published: August 2021

In order to reduce the overall size of the shipborne radar and improve the reliability of signal transmission, a miniaturized design has been carried out on the shipboard radar confluence ring. The miniaturized confluence ring adopted the electric contact form that the brush wires and the conductive ring are matched. The brush wires and the conductive ring coating used high-performance noble metal electrical contact materials, and the contact force was designed to be 0.1N to ensure the reliable and effective electrical contact. In addition, the dynamic design analysis method (DDAM) was used to analyze the shock resistance of the confluence ring. The test results showed that the size of the confluence ring had been reduced, all performance indicators met the requirements, and reliable transmission of various signals could be realized; the calculation results showed that the maximum impact stress of the confluence ring was less than the yield strength of the shell material, which met the requirements of the ship equipment shock resistance design requirements. The design method and analysis results have reference value and guiding significance for the miniaturization design and shock assessment of shipborne radar confluence ring.
Adaptive fuzzy control method of hydrogen fuel cell gas supply system
Authors: Wang Weidong , Chen Jing , Xiao Chun , Cheng Nanding
Published: August 2021

This paper takes the hydrogen fuel cell gas supply system as the research object. Firstly, it analyzes the working principle of the hydrogen fuel cell and the control requirements of the gas supply system, then uses the fuzzy adaptive PID control algorithm to regulate the gas pressure of the system. Finally, Matlab/Simulink software simulation platform is used for simulation verification, and the control effects of conventional PID control and fuzzy adaptive PID control are compared. The results show that the gas supply system based on fuzzy adaptive PID control can effectively regulate the gas pressure value and has a good control effect.
Research on hidden dangers of oil-flow relay in HVDC converter transformer
Authors: Chen Kun , Yao Qixin , Huang Zengrui , Wang Ting
Published: August 2021

HVDC converter transformer oil-flow relay plays an important role in realizing non-power protection of converter transformer on-load tap changer, which can act accurately and directly affect the safe and stable operation of the whole HVDC program as well as the converter transformer itself. In this paper, the research revolves the hidden dangers of HVDC converter transformer and its identification. The paper begins with the analysis of the converter transformer operating principles of two German companies: MR and EMB. Then, the current application status and related inspection requirements of oil-flow relay are expounded. Finally, pertinent hidden danger identification and modification schemes are provided based on analysis of the danger in actual operation of oil-flow relay and its causes. The feasibility and effectiveness of the scheme are verified by the actual operation on site.
Supercapacitor hybrid energy storage system applied to photovoltaic power generation
Authors: Liu Hui , Zhu Longji
Published: August 2021

In order to solve the problem of power pulsation at the DC bus side caused by uneven illumination or load fluctuation, a hybrid energy storage system for supercapacitors is proposed. In the hybrid energy storage circuit, inductors are added to form a high-frequency filter with the supercapacitor, and the supercapacitor absorbs the high-frequency current component of the DC side. The traditional droop control strategy is adopted to effectively filter the high-frequency current component of the battery side, and the battery is responsible for processing the low-frequency current component. The simulation results show that the proposed hybrid energy storage system can reduce the voltage pulsation of the DC bus, and the response and recovery speed is faster, which can effectively suppress the power pulsation on the side of the photovoltaic DC bus.
State-of-health estimation and remaining useful life prediction of lithium-ion batteries based on extreme learning machine
Authors: Wei Meng , Ye Min , Wang Qiao , Wu Chenguang , Ma Yuchuan
Published: August 2021

Lithium-ion batteries have been widely applied in electric vehicles, accurate health state prediction of batteries is one of the key technologies to obtain optimal operation and health management. To achieve the highly accurate state of health (SOH) estimation and remaining useful life (RUL) prediction, a framework based on extreme learning machine (ELM) is proposed. Firstly, the indirect health indicators are extracted from discharge data. Then, the ELM model is proposed to estimate SOH and predict RUL. Finally, the propagation neural network based on particle swarm optimization (BPNN-PSO) is compared with the ELM method. The results show that proposed method hits lower average root mean square error for SOH and RUL.
Total ionizing dose effects on data retention characteristics of 55nm SONOS flash
Authors: Guo Xuanchen , Yue Suge , Li Jiancheng , Zhou Tao , Zha Qichao
Published: August 2021

This paper researched on the effect of different bias conditions on the data retention characteristics of 55nm SONOS flash at a high total dose of 200 Krad(Si). The results show that the degradation of SONOS flash data retention characteristics is the most serious under static bias condition. And the data error rate is positively correlated with read frequency. But overall, the total ionizing dose (TID) has little effect on the data retention characteristics of SONOS flash.
State estimation based on least square support vector
Authors: Li Jiabo , Ye Min , Gao Kangping , Wei Meng , Jiao Shengjie
Published: August 2021

As one of the important parameters of battery management system (BMS), accurate estimation of the state of charge (SOC) of lithium-ion battery (LIB) can ensure the safety of electric vehicles and improve the utilization rate of batteries. A new SOC estimation algorithm based LSSVM is applied. The battery parameters, including current and voltage, which are used as the inputs to estimate SOC. To promote the accuracy of SOC estimation, the SOC estimated at the previous time is taken as the feedback vector to estimate the SOC at the current time. The experimental results show that the proposed model can improve the estimation accuracy of SOC.
Design of intelligent supervision system for metrology center based on UWB technology
Authors: Wei Lei , Yu Jian , Zhao Xingwang , Pan Wei
Published: August 2021

With the comprehensive construction of the provincial metrology center, further digital management requirements are put forward for the daily operation and maintenance inspection work of the automated verification/testing area, the warehouse storage area, the material supporting turnover area and the temporary storage area, and the professional laboratory area. The article explains the UWB (ultra-wide band) technology and its principles and applies it to the smart supervision of the production area. It has developed functions such as basic information management, job attendance, positioning analysis, electronic fence, behavior monitoring, intelligent inspection and data analysis. The digital supervision plan has been verified in the actual production environment.
Research on reliability evaluation method of protection system based on Kaplan-Meier and GO method
Authors: Wang Ting , Chen Kun , Zhang Yanxia , Zhang Kanjun , Du Zhen’an , Xiao Fang
Published: August 2021

In the reliability analysis of the traditional substation protection system, methods such as minimum path set method, fault tree method and Markov method are mostly used. These three methods have disadvantages such as large amount of calculation and strong subjectivity in the application process. Based on the shortcomings of traditional reliability analysis methods, this paper proposes a protection system reliability evaluation method based on survival analysis plus GO method. In view of the problem of timing truncation of the failure data of the protection system and the different time of operation of the protection device, the survival analysis (Kaplan-Meier) method is used to estimate the reliability of the equipment in different time periods, and the GO method is combined to obtain the GO graph of the protection system and GO operation, and then get the reliability of the entire protection system. The results show that the method can quantitatively calculate the reliability of the relay protection system, has the advantages of simplicity, intuitiveness, and easy computer programming. It can be used to analyse the reliability of the relay protection system and guide the design, operation and maintenance of the substation.
A vision based method for humping detection in high-speed laser welding
Authors: Xue Boce , Chang Baohua , Du Dong
Published: August 2021

In this paper a vision based detection method for humping in high-speed laser welding is proposed. A high-speed imaging system is used to capture the images of melt pool in the near-infrared range and the unaffected melt pool region is extracted as the ROI (region of interest) according to the structure of images. The occurrence of humping and positions of humps are determined according to the geometric characteristics of the melt pool in the ROI. Experimental results indicate that the proposed method can detect positions of humps when humping occurs and can also avoid false detection when no humping occurs. The potential of the proposed method is demonstrated for humping control.
Numerical study of a hybrid mode-locked erbium-doped fluoride fiber laser at 2.8 μm
Authors: Luo Meizhen , Tang Pinghua , Ji Haining , Liu Bin , Peng Jie , Tan Chao , Mao Yuliang
Published: August 2021

We numerically investigate a hybrid mode-locked erbium-doped fluoride fiber laser in the mid-infrared region. Based on the coaction of nonlinear polarization rotation (NPR) and semiconductor saturable absorber mirror (SESAM), uniform mode-locked soliton pulse with 155 fs pulse duration, 14.78 kW peak power, and 2.29 nJ pulse energy can be achieved. For comparison, the single SESAM mode-locking and NPR mode-locking of the erbium-doped fluoride fiber laser are simulated, respectively. The effect of all kinds of parameters including gain fiber length, saturable energy of the gain fiber, linear cavity phase delay bias, and small-signal gain on the hybrid mode-locking laser are also investigated.
Tugboat scheduling problem in large container ports: A case study of the Singapore port
Authors: Yu Haocheng
Published: August 2021

In recent years, more and more container ports have become congested because of the large number of visiting ships to the ports. This causes a difficult dispatching and management problem for port operators, that is, the tugboat scheduling problem. To solve the problem effectively from the operational viewpoint, this study proposes an interesting tugboat scheduling problem in a large container port. A mixed-integer linear programming (MILP) model is built for the problem with the objective function of minimizing the total processing cost for container ships. We also consider the constraints of horsepower limitation of tugboats, utilization time limit of tugboats, etc. By using the commercial solver CPLEX to solve the built MILP model in a case study of the Singapore Port, the efficiency of the MILP model is presented. It takes less than 18 hours to reduce the optimality gap to a maximum of 0.9% for solving a real-size instance with 12 tugboats and 100 ships. Moreover, the results of extensive computational experiments also show the applicability and effectiveness of the MILP model to handle real-world tugging operations.
A case study of intelligent manufacturing for key components of vehicles
Authors: Liu Xiaogang , Sun Xinrong , Xu Jinli
Published: August 2021

Currently, most research on intelligent manufacturing stays at the theoretical stage, which can enhance the understanding of smart factory concepts, but it is still difficult to establish a clear strategy for the industry. In this research, cyber-physical system (CPS) is applied to connect the manufacturing equipment of the production system, so as to develop the internet of things (IoT) object layer. Furthermore, a smart factory framework consisting of IoT object layer, CPS network layer, and CPS service layer is developed, connecting the smart shop-floor and the cloud service platform through the industrial network so as to implement the integration of physical manufacturing and virtual manufacturing. This framework is applied in the production of vehicle components, and the results show that the application of this framework in an actual automobile chassis smart factory can greatly improve production efficiency and energy efficiency, reduce enterprise costs, and shorten product development cycles, accelerating the process of enterprise transformation to informatization, digitalization, and intelligence. Since this framework for intelligent manufacturing has been verified under actual conditions, it can be taken as a reference for further development of the framework for intelligent manufacturing.
A simple and effective assembly sequence design method
Authors: Shao Chao , Zhou Yuanzi , Zhang Qiang , Tang Yuhang , Jiang Jun
Published: August 2021

Assembly sequence design is a very complex problem in military enterprises due to the particularity of the military industry and the batch production. This paper proposed a method based on the existing expert knowledge and experience used to plan the assembly sequence. The method of assembly sequence design method is quantitative calculated based on five indexes, including assembly element benchmark index, assembly adjacency index, assembly process complexity index, assembly accuracy index, symmetry index of assembly primitives. And then construct geometric interference matrix to analyze the geometric feasibility of the assembly sequence. Finally, the procedure of assembly process sequence planning of flat-plate fuze is taken as an example to verify the effectiveness of this method. This method is suitable for the assemblies with less number of parts. It has been proved that this method based on the existing expert knowledge and experience, can quickly plan the assembly process sequence of parts.