bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial mapping of exciton transition energy and strain in composition graded WS2(1−x)Se2x monolayer
Authors: Jalouli Alireza , Kilinc Muhammed , Wang Peijian , Zeng Hao , Thomay Tim
Published: September 2020

We studied the optical properties of a composition graded WS2(1−x)Se2x alloy monolayer. A symmetric gradual composition gradient from a Se-rich center to the relatively less Se-rich edges of an equilateral triangle shaped flake is confirmed by Raman mapping. Photoluminescence (PL) mapping shows a large 100 meV variation in the exciton energy, resulting from the composition dependent bandgap variation and carrier localization. The alloying leads to symmetry breaking and large nonlinear optical susceptibility. Second harmonic generation (SHG) mapping was carried out to study the non-linear properties and additionally to determine the lattice strain of the alloy flake. In contrast to PL and Raman mappings, SHG intensity is found to be spatially uniform. However, polarization dependent SHG reveals a unidirectional strain parallel to the (zigzag) edge of the flake, in addition to the sixfold symmetry expected from the transition metal dichalcogenide (TMD) lattice. Our results suggest potential applications of composition graded TMD alloys as ultra-compact color-tunable light sources and miniaturized spectrometers.
Broadband acoustic silencer with ventilation based on slit-type Helmholtz resonators
Authors: Nguyen Huy , Wu Qian , Xu Xianchen , Chen Hui , Tracy Sharon , Huang Guoliang
Published: September 2020

Recently, sound attenuation with ventilation is highly needed in many practical applications. In this study, we report on a subwavelength acoustic silencer, named double-layer acoustic silencer (DAS), based on compactly assembled slit-type Helmholtz resonators (SHRs) for low-frequency broadband sound insulation while preserving ventilation. A simple yet insightful theoretical model is first established to characterize the sound insulation performance in terms of transmission loss (TL) and used for microstructure designs of the DAS. The fluctuating TL of the DAS, inevitably produced by the SHR resonances, is then mitigated and optimized via the introduction of viscosity and proper SHR frequency detuning. The overall TL is numerically investigated and experimentally observed to reach beyond 30 dB over the target working band of 0.48–0.95 kHz, with a maximum exceeding 50 dB. In addition, the proposed design also provides perfect ventilation when deployed in a duct environment, due to the straight and conserved airflow cross section. We believe that the proposed acoustic silencer design and its associated theoretical model pave the way for designing and optimizing highly efficient low-frequency subwavelength acoustic liners and silencers.
Electrostatic-doping-controlled phase separation in electron-doped manganites
Authors: Xu Dong-Dong , Ma Ru-Ru , Zhang You-Shan , Deng Xing , Zhang Yuan-Yuan , Zhu Qiu-Xiang , Zhong Ni , Tang Xiao-Dong , Xiang Ping-Hua , Duan Chun-Gang
Published: September 2020

The coexistence of distinct insulating and metallic phases within the same manganite sample, i.e., phase separation scenario, provides an excellent platform for tailoring the complex electronic and magnetic properties of strongly correlated materials. Here, based on an electric-double-layer transistor configuration, we demonstrate the dynamic control of two entirely different phases—canted G-type antiferromagnetic metal and C-type antiferromagnetic charge/orbital ordered insulator phase—in electron-doped system Ca1−xCexMnO3 (x = 0.05). The reversible metal-to-insulator transition, enhanced colossal magnetoresistance (∼ 27 000% for Vg = 3.0 V), and giant memory effect have been observed, which can be attributed to an electronic phase separation scenario manipulated by a tiny doping-level-variation of less than 0.02 electrons per formula unit. In addition, the controllable multi-resistance states by the combined application of magnetic and electrostatic fields may serve as an indicator to probe the dynamic multiphase competition of strongly correlated oxides. These results offer crucial information to understand the physical nature of phase separation phenomena in manganite systems.
Impact shock origin of diamonds in ureilite meteorites
Authors: Nestola Fabrizio , Goodrich Cyrena A. , Morana Marta , Barbaro Anna , Jakubek Ryan S. , Christ Oliver , Brenker Frank E. , Domeneghetti M. Chiara , Dalconi M. Chiara , Alvaro Matteo , Fioretti Anna M. , Litasov Konstantin D. , Fries Marc D. , Leoni Matteo , Casati Nicola P. M. , Jenniskens Peter , Shaddad Muawia H.
Published: September 2020

Significance

The origin of diamonds in ureilites is still a debated issue among the scientific community, with significant implications for the sizes of early Solar System bodies. We investigated three diamond-bearing ureilites by a multimethodological approach using scanning electron microscopy, micro X-ray diffraction, transmission electron microscopy, and micro-Raman spectroscopy, with the aim of determining the origin of the diamonds. Our results show that formation of both microdiamonds and nanodiamonds in ureilites can be explained by impact shock events on a small planetesimal and does not require long growth times at high static pressures within a Mercury- or Mars-sized body.
Fast behavioral feedbacks make ecosystems sensitive to pace and not just magnitude of anthropogenic environmental change
Authors: Gil Michael A. , Baskett Marissa L. , Munch Stephan B. , Hein Andrew M.
Published: September 2020

Significance

Human activities can alter the behavior of wildlife. Although behavior is known to affect species interactions and demography, behavioral feedbacks are often absent from the types of population models used to understand how ecosystems respond to anthropogenic change. We show that incorporating empirically measured fish feeding behavior into dynamical models of a coral reef alters how the ecosystem responds to fishing. Fish behavior can cause ecosystem collapse in response to less fishing but also, unexpectedly, to subtle differences in the pace at which fishing increases. Behavioral mechanisms similar to those included in our model are present in many ecological systems, and our findings suggest these mechanisms could inform both fundamental understanding and management strategies in such systems.
Nuclear receptor REVERBα is a state-dependent regulator of liver energy metabolism
Authors: Hunter A. Louise , Pelekanou Charlotte E. , Adamson Antony , Downton Polly , Barron Nichola J. , Cornfield Thomas , Poolman Toryn M. , Humphreys Neil , Cunningham Peter S. , Hodson Leanne , Loudon Andrew S. I. , Iqbal Mudassar , Bechtold David A. , Ray David W.
Published: September 2020

Significance

The circadian clock protein REVERBα is proposed to be a key regulator of liver metabolism. We now show that REVERBα action is critically dependent on metabolic state. Using transgenic mouse models, we show that the true role of REVERBα is to buffer against aberrant responses to metabolic perturbation, rather than confer rhythmic regulation to programs of lipid synthesis and storage, as has been thought previously. Thus, in the case of liver metabolism, the clock does not so much drive rhythmic processes, as provide protection against mistimed feeding cues. Understanding how the clock is coupled to metabolism is critical for understanding metabolic disease and the impacts of circadian disruptors such as shift work and 24-h lifestyles.
Roboticizing fabric by integrating functional fibers
Authors: Buckner Trevor L. , Bilodeau R. Adam , Kim Sang Yup , Kramer-Bottiglio Rebecca
Published: September 2020

Significance

Fabrics are key materials for a variety of applications that require flexibility, breathability, small storage footprint, and low weight. While fabrics are conventionally passive materials with static properties, emerging technologies have provided many flexible materials that can respond to external stimuli for actuation, structural control, and sensing. Here, we improve upon and process these responsive materials into functional fibers that we integrate into everyday fabrics and demonstrate as fabric-based robots that move, support loads, and allow closed-loop controls, all while retaining the desirable qualities of fabric. Robotic fabrics present a means to create smart adaptable clothing, self-deployable shelters, and lightweight shape-changing machinery.
Generation of thermofield double states and critical ground states with a quantum computer
Authors: Zhu D. , Johri S. , Linke N. M. , Landsman K. A. , Huerta Alderete C. , Nguyen N. H. , Matsuura A. Y. , Hsieh T. H. , Monroe C.
Published: September 2020

Significance

Our experiment prepares two types of nontrivial quantum states on a trapped ion quantum computer: the thermofield double state of the transverse-field Ising model at arbitrary temperature and the quantum critical state of the zero-temperature model. We use techniques motivated by the quantum approximate optimization algorithm, and we implement a hybrid quantum–classical optimization loop to prepare the quantum critical state. Our results pave the way for exploring strongly correlated models at finite temperature and teleportation protocols inspired by black hole physics.
Adaptive introgression from maize has facilitated the establishment of teosinte as a noxious weed in Europe
Authors: Le Corre Valérie , Siol Mathieu , Vigouroux Yves , Tenaillon Maud I. , Délye Christophe
Published: September 2020

Significance

The emergence of noxious weeds poses a serious threat to agricultural production. Understanding their origin and evolution is therefore of major importance. Here we analyzed the intriguing case of teosinte, a wild relative of maize originating from Mexico that recently emerged as an invasive weed in maize fields in Europe. Patterns of genetic variation revealed extensive genetic introgression from maize adapted to temperate latitudes into European teosintes. Introgressed genomic regions harbored a key flowering time gene and an herbicide resistance gene. Our results exemplify how adaptive introgression can drive the evolution of a crop’s wild relative into a weed. Hybridization is an evolutionary force that should not be underestimated when forecasting invasiveness risks.
Global COVID-19 pandemic demands joint interventions for the suppression of future waves
Authors: Li Ruiyun , Chen Bin , Zhang Tao , Ren Zhehao , Song Yimeng , Xiao Yixiong , Hou Lin , Cai Jun , Xu Bo , Li Miao , Chan Karen Kie Yan , Tu Ying , Yang Mu , Yang Jing , Liu Zhaoyang , Shen Chong , Wang Che , Xu Lei , Liu Qiyong , Bao Shuming , Zhang Jianqin , Bi Yuhai , Bai Yuqi , Deng Ke , Zhang Wusheng , Huang Wenyu , Whittington Jason D. , Stenseth Nils Chr. , Guan Dabo , Gong Peng , Xu Bing
Published: September 2020

Significance

By linking seasonality of climate and changing human behavior, we demonstrate that collaboration on global efforts for prompt and intensive intervention is fundamental to coping with future pandemic waves of COVID-19. We propose that this collaboration can be started in locations with typically high population density and international travel, followed by other high-risk locations. We believe this tiered intervention strategy can greatly integrate global efforts and is effective and practical to improve the global emergency response to COVID-19 and many other infectious diseases.
Genetic nurturing, missing heritability, and causal analysis in genetic statistics
Authors: Shen Hao , Feldman Marcus W.
Published: September 2020

Significance

Correlation between genotypes and phenotypes can be produced by genetic nurturing, namely the effect of parents’ genotypes on their offspring’s phenotypes through the parents’ phenotypes. Population subdivision and assortative mating can give rise to correlations between genotypes and phenotypes similar to those due to genetic nurturing. Variances and correlations may not reveal causal relationships in the presence of these complexities. We analyze mechanistic models of genetic nurturing, population subdivision, and assortative mating and compare these with results obtained within the framework of modern causal analysis. Our results clarify statistical signals emanating from correlations between nontransmitted alleles and offspring phenotypes and reveal difficulties with standard linear models in the interpretation of heritability, in particular, the concept of missing heritability.
Indic Religiosity Scale: Developing and Validating an Indian Religiosity Scale
Authors: Jayakumar Tulsi , Verma Anshul
Published: September 2020

The religiosity of one of the world's most populous countries and of its people who constitute the largest diaspora in the world – India, has been ill-researched and ill-captured. A religiosity scale that is grounded in a theoretical understanding of the Indic religions –
religions which originated in India – needs to be developed. This scale should demonstrate validity and reliability, besides being parsimonious. An Indic Religiosity Scale based on the commonalities of the major Indic religions – Hinduism, Jainism, Sikhism and Buddhism –
is developed and validated as a measure for crosscultural studies on religiosity. A 15-item construct with five factors emerged as a valid and reliable measure of religiosity. The five factors include Way of Life; Belief in Rebirth, Karma and Destiny; Existence of Supreme Power; Importance
of Prayer and Purposeful Life. The Indic Religiosity Scale (IRS) – with its parsimony and ease of use – can be used in multiple managerial contexts and organizational settings including cross-cultural settings, involving religiosity as a construct.
COPA silences STING
Authors: Rivara Sophie , Ablasser Andrea
Published: September 2020

Two studies published in this issue of JEM, by Lepelley et al. (https://doi.org/10.1084/jem.20200600) and Deng et al. (https://doi.org/10.1084/jem.20201045), and two additional manuscripts by Mukai et al. (https://doi.org/10.1101/2020.05.20.107664 Preprint v1) and Steiner et al. (https://doi.org/10.1101/2020.07.09.194399 Preprint v1) demonstrate that COPA syndrome–associated high interferon titers are linked to mutations in COPA preventing STING’s retrieval from the Golgi back to the ER and thereby causing chronic immune activation.
TiO2 modified orthocortical and paracortical cells having enhanced photocatalytic degradation and photoreduction properties
Authors: Chen Wendou , Zhang Hui , Chen Tianyu , Yang Limeng , Wu Hailiang , Tong Zhi , Mao Ningtao
Published: September 2020

In this study, cortical cells resultant from wool fibers were loaded with TiO2 nanoparticles in a hydrothermal process and were then engineered as organic-nonorganic hybrid composite photocatalysts for both photodegradation of organic dyes and photoreduction of heavy metal ions. The microstructure and photocatalytic properties of TiO2 modified cortical cells (i.e. both orthocortical and paracortical cells) were systematically characterized using a series of analytical techniques including FESEM, TEM, element analysis, Mott–Schottky curve, BET specific surface area, Zeta potentials, as well as XRD, FTIR, XPS, DRS, PL, UPS, EDS and ESR spectra. Their photocatalytic performance and trapping experiments of the TiO2 modified cortical cells were measured in the photodegradation of methylene blue (MB) dye and Congo Red (CR) dye as well as the photoreduction of Cr(VI) ions under visible light irradiation. It was found that anatase TiO2 nanoparticles were chemically grafted on the surface of the two cortical cells via O–Ti4+/O–Ti3+ bonds, and that TiO2 nanoparticles were formed inside the orthocortical cells in the hydrothermal process. The TiO2 modified orthocortical and paracortical cells possessed much higher photocatalytic efficiency than the commercially available TiO2 nanoparticle powder, Degussa P25, in the photodegradation of cationic MB dye and photoreduction of Cr(VI) ions, while their photocatalytic efficiency in the photodegradation of anionic CR dye is smaller because of their greater negative Zeta potentials and photogenerated holes as the main reactive radical species. In comparison with the TiO2 modified paracortical cells, the higher photocatalytic efficiency of the TiO2 modified orthocortical cells was demonstrated in the photodegradation of MB dye solution and this might be due to both the S-doped TiO2 nanoparticles infiltrated into the naturally hydrophilic orthocortical cells and the primary reactive radical species of photogenerated holes being trapped in the cells.
Patient-adaptable intracranial pressure morphology analysis using a probabilistic model-based approach
Authors: Rashidinejad Paria , Hu Xiao , Russell Stuart
Published: September 2020

Objective: We present a framework for analyzing the morphology of intracranial pressure (ICP). The analysis of ICP signals is challenging due to the non-linear and non-Gaussian characteristics of the signal dynamics, inevitable corruption by noise and artifacts, and variations in ICP pulse morphology among individuals with different neurological conditions. Existing frameworks make unrealistic assumptions regarding ICP dynamics and are not tuned for individual patients.Approach: We propose a dynamic Bayesian network for automated detection of three major ICP pulsatile components. The proposed model captures the non-linear and non-Gaussian dynamics of ICP morphology and further adapts to a patient as the individual’s ICP measurements are received. To make the approach more robust, we leverageevidence reversaland present an inference algorithm to obtain the posterior distribution over the locations of pulsatile components.Main results: We evaluate our approach on a dataset with over 700 h of recordings from 66 neurological patients, where the pulsatile components were annotated by prior studies. The algorithm obtains accuracies of 96.56%, 92.39%, and 94.04% for the detection of each pulsatile component in the test set, showing significant improvement over existing approaches.Significance: Continuous ICP monitoring is essential in guiding the treatment of neurological conditions such as traumatic brain injuries. An automated approach for ICP morphology analysis is a step towards enhancing patient care with minimal supervision. Compared to previous methods, our framework offers several advantages. It learns the parameters that model each patient’s ICP in an unsupervised manner, resulting in an accurate morphology analysis. The Bayesian model-based framework provides uncertainty estimates and reveals interesting facts about the ICP dynamics. The framework can readily be applied to replace existing morphological analysis methods and support the use of ICP pulse morphological features to aid the monitoring of pathophysiological changes of relevance to the care of patients with acute brain injuries.
Dielectric, impedance and modulus spectroscopy of Pb(Zr0.52−x
Ce
x
Ti0.48)O3 (x = 0.00, 0.10) ferroelectric ceramics
Authors: Tiwari Balgovind , Babu T , Choudhary R N P
Published: September 2020

Lead zirconate titanate (PZT) ceramics of morphotropical phase boundary (MPB) composition shows enhanced physical properties on modification with suitable ions. In this work, Pb(Zr0.52-xCe
x
Ti0.48)O3, x = 0.00, 0.10 (PZCT) ferroelectric ceramics have been synthesized by solid state synthesis route. The ferroelectric nature of samples is confirmed by their transition of phase from the ferroelectric phase to the paraelectric phase. At 1 MHz frequency, the Curie temperature (T
c
) of the material is slightly decreased to ∼375 °C from ∼377 °C. But at the aforementioned frequency, the magnitude of relative dielectric constant (ϵ

r
) has been enhanced to ∼282 from ∼264 due to the substitution of cerium (Ce+4) ions at the zirconium site. Even at higher frequencies ranging from 1 kHz to 1 MHz, Ce modified PZT has shown negligible tangent loss (tan δ) upto 350 °C. The electrical response of the material is mainly governed by grain interiors only not by grain boundaries and electrode-interface. Electric modulus formalism analysis confirmed the occurrence of non-Debye type of electrical relaxation phenomenon in the material. The electrical conduction of the material is a thermally activated phenomenon, and it is governed by Jonscher's power law. The decrease in resistance of the compounds, with rise in temperature, indicate their semiconductor behavior (i.e. negative temperature coefficient of resistance behavior) at higher temperatures.
The vimentin cytoskeleton: when polymer physics meets cell biology
Authors: Patteson Alison E , Carroll Robert J , Iwamoto Daniel V , Janmey Paul A
Published: September 2020

The proper functions of tissues depend on the ability of cells to withstand stress and maintain shape. Central to this process is the cytoskeleton, comprised of three polymeric networks: F-actin, microtubules, and intermediate filaments (IFs). IF proteins are among the most abundant cytoskeletal proteins in cells; yet they remain some of the least understood. Their structure and function deviate from those of their cytoskeletal partners, F-actin and microtubules. IF networks show a unique combination of extensibility, flexibility and toughness that confers mechanical resilience to the cell. Vimentin is an IF protein expressed in mesenchymal cells. This review highlights exciting new results on the physical biology of vimentin intermediate filaments and their role in allowing whole cells and tissues to cope with stress.
Non-linear extended MHD simulations of type-I edge localised mode cycles in ASDEX Upgrade and their underlying triggering mechanism
Authors: Cathey A. , Hoelzl M. , Lackner K. , Huijsmans G.T.A. , Dunne M.G. , Wolfrum E. , Pamela S.J.P. , Orain F. , Günter S.
Published: September 2020

A triggering mechanism responsible for the explosive onset of edge localised modes (ELMs) in fusion plasmas is identified by performing, for the first time, non-linear magnetohydrodynamic simulations of repetitive type-I ELMs. Briefly prior to the ELM crash, destabilising and stabilising terms are affected at different timescales by an increasingly ergodic magnetic field caused by non-linear interactions between the axisymmetric background plasma and growing non-axisymmetric perturbations. The separation of timescales prompts the explosive, i.e. faster than exponential, growth of an ELM crash which lasts

∼
500
 
μ

s

. The duration and size of the simulated ELM crashes compare qualitatively well with type-I ELMs in ASDEX Upgrade. As expected for type-I ELMs, a direct proportionality between the heating power in the simulations and the ELM repetition frequency is obtained. The simulations presented here are a major step forward towards predictive modelling of ELMs and of the assessment of mitigation techniques in ITER and other future tokamaks.
Design of flow cytometer liquid circuit control system based on incremental PID algorithm
Authors: Yu Lihua , Song Shuxiang
Published: September 2020

In the application and design of the flow cytometry, the problem of controlling the flow rate of liquid sample should be considered, which is directly related to the test performance of the instrument. In this paper, a flow cytometer liquid path controlling system based on incremental PID algorithm is designed. The STM32F429 is used as the core control chip, and a negative feedback correction network is introduced. At the same time, the incremental PID algorithm is used to control the speed of electronic motor. Combining with the hardware circuit, the automatic regulation and control of the flow rate of liquid path sample are realized. The experimental results show that the real-time sample flow can approach to the set value quickly and stably after the sampling started in this system. When different target values are set, the error between the measured value and the set value is less than 3%. The system is simple in design, high accuracy and stability, and can meet the requirements of intelligent control and high efficiency and precision in modern industrial instruments.
Analysis on vibration coupling characteristics of high-speed gears in two-shift AMT
Authors: Sun Danting , Song Qiang , Zhang Wei
Published: September 2020

In order to study the vibration coupling influence of no-load gear on the loaded gear with the driving motor speed increasing for pure electric vehicles, a two-shift automated mechanical transmission (AMT) is researched. Nonlinear dynamic models of the shift II gear pair and the coupled relationship between the two gear pairs are established. Vibration characteristics of the shift II gear pair under different speeds are analysed. The results show that the multi-gear coupling vibration makes the system easier to enter into complex multi-period motion or chaos at high speed, thus increasing the noise of the drive system.
Research on erosion model based on AISI 8630
Authors: Rong Xin , Zhu Hongwu
Published: September 2020

Subsea oil tree is the key equipment for offshore oil and gas extraction, and erosion will cause wall-thinning phenomenon of equipment, which will decrease the equipment’s pressure-bearing capacity and cause great safety risks. In this paper, a new erosion model is proposed by studying the erosion law of the common material (AISI 8630) in subsea tree. The mechanism of erosion is explained by observing the change in the surface micro-morphology of the erosion pit photographed by scanning-electron microscope. The effect of five factors including particle size, particle impact velocity, particle impact angle, particle concentration and impact duration on the erosion are also investigated. And the AISI 8630 erosion model is obtained through data analysis. By comparing the results of experiment and numerical simulation, it is found that the simulation error of the AISI 8630 erosion model is the smallest between four common erosion models. So, it can be concluded that the AISI 8630 erosion model can be used to study the erosion of underwater tree.
Reduced conservation error of kinetic energy using a Runge-Kutta algorithm with reduced numerical dissipation
Authors: Suzuki Hiroki , Hasebe Koudai , Hasegawa Yutaka , Ushijima Tatsuo
Published: September 2020

This paper describes an approach that reduces the error in the conservation law of velocity fluctuation intensities and turbulent kinetic energy resulting from a numerical analysis of incompressible flow. The optimized fourth-order Runge-Kutta method used to analyze acoustic problems in previous studies was used here to reduce the numerical dissipation. In order to strictly validate the conservation law of velocity fluctuation intensities and turbulent kinetic energy, the authors used a periodic box filled with an inviscid flow, where velocity fluctuation intensities and turbulent kinetic energy could be analytically held. By using the optimized Runge-Kutta method, the numerical dissipation, which is the error in conservation laws, is of the order of 1/100. The reduction in the numerical dissipation shown in this study increased with an increasing time increment. To investigate the effect of numerical dissipation, higher-order statistics of turbulent kinetic energy were calculated. This study also derived a simple mathematical form to estimate the conservation error of higher-order statistics for turbulent kinetic energy.
Influence of synthetic jet in crossflow configuration on heat transfer enhancement
Authors: Xiang Liping , Liu Yueyue , Huang Kunrong , Huang Yi
Published: September 2020

A two-dimensional computational model was developed to investigate the effect of synthetic jet interaction with crossflow in channel on the cooling of heat wall. A range of parametric studies by varying membrane oscillating amplitudes and inlet velocities of channel was conducted. The resulting complex, conjugate heat dissipation was analysed. The synthetic jet interacts with the channel flow and gives rise to heat dissipation enhancement at the heated wall. The upstream heat transfer deteriorates in the jet hole, and the heat transfer in the downstream region has improved.
The design of pneumatic manipulator for optical shaft production line
Authors: Jin Zuoyong , Meng Lijun
Published: September 2020

Manipulator is a powerful tool for human to work safely, realize production automation and improve labor productivity. On the basis of summarizing the research and development status of manipulator, this paper comprehensively analyzes the function of pneumatic carrying manipulator on optical axis production line, and combines the actual project of the enterprise to design the mechanical and electrical integration of pneumatic carrying manipulator. This paper analyzes the performance requirements and working characteristics of pneumatic conveying manipulator and combines with the characteristics of optical shaft production line. I comprehensively analyzed and designed the mechanical structure, drive system, transmission mode and its stability of the manipulator.
A new model to resolve technical problems
Authors: Zhang Shijun , Zhang Teng , Wang Haijie
Published: September 2020

The Algorithm for Inventive Problem Solving (ARIZ) is a very good tool to solve complicated problems. However, it is fussy to get a specific solution under the guides of ARIZ in the Theory of Inventive Problem Solving (TRIZ). A novel approach to getting solutions for inventive problem solving in TRIZ is shown in this paper. A model named 5-R model of finding specific solutions was developed. 5-R model has four steps to obtain specific suggested solutions for technical problems. Reason-occurred-analysis is the first step in this new model. Then a clear statement of the Ideal Final Result is used to encourage breakthrough thinking and get solutions to the problem. After that, suggested resolutions can be obtained with the Contradiction Matrix, the Physical Contradiction, the Substance-Field, the Effects, Function Analysis, System Enhancement route, and Substance-Field Analysis. Finally, a reasonable specific solution for innovative problem solving can be gotten using resource analysis. 5-R model is not difficult to learn and remember. 5-R model improves the efficiency of getting solutions with TRIZ. Finally, a practical engineering problem was solved using this now model successfully.
Research on electro-hydraulic control technology of train with long distance self-moving equipment
Authors: Song Tao , Zhang Fan
Published: September 2020

Aiming at the problems of manual laying of tracks, sliding car and dropping lanes in the process of traditional train transportation of winch traction equipment, this paper presents a long-distance self-moving equipment train, which is powered by hydraulic pressure, self-contained track, highly integrated train self-moving, walking deviation, anti-dropping and other functions, so as to realize the striding forward movement of the whole equipment train driven by the traction device. Innovative adopt of loop liquid supply, multiple group remote control and other technologies, and using multi-master control, and high reliability, strong anti-interference CAN (Controller Area Network) fieldbus real-time control network, it ensures the synchronous and smooth lifting of the train, and it moves forward with the self-moving traction device. Thereby, the automatic system development and demonstration application of the fully mechanized mining equipment can be realized.
Stability evaluation of transmission tower above the goaf by fuzzy comprehensive evaluation method and analytic hierarchy process
Authors: Qi Wenyan , Ye Fang , Qi Wenyue , Li Tian , Guan Sensen , Fu Siwei , Zhang Xunda , Chen Shaoyu
Published: September 2020

Combination of the load-bearing conditions, the tower shape and service time, and the geological and basic conditions of the service environment of the tower, various factors that influence the stability of the towering tower near goaf were classified by using fuzzy comprehensive evaluation method and AHP, and the influence factor model was established. The impact factors were evaluated from low to high, the influence of the geological and basic conditions of the service environment is maximal, and determined the approximate rock roadway is stable and no measures need to take to improve the stability of the tower.
Numerical study on temperature distribution of the hot-plate under induction heating
Authors: Wang Jin , Chen Xing , Sun Baoshou
Published: September 2020

In this paper, a novel method based on electromagnetic heating theory is introduced to achieve a stable and uniform temperature distribution on the target surface of the hot-plate. The heat process of hot-plate is divided into two stages. At first, the thin layer of S45C was coated on the surface of the hot-plate by thermal spraying. Due to skin effect, coated S45C layer can be considered as heat source in terms of the law of electromagnetic heating. Secondly, the hot-plate made of pure aluminium with a high thermal conductivity can be employed to reduce the temperature difference. Finally, the target surface temperature of the hot-plate is stabilized at specific temperature by changing the holding current.
Analysis of the mechanical coupling characteristics of a monolithic tri-axis MEMS gyroscope
Authors: Wang Yue , Chen Zhiyong , Zhou Bin , Wei Qi , Zhang Rong
Published: September 2020

The mechanical coupling characteristics of a monolithic tri-axis micro-electromechanical gyroscope have an important effect on the performance of the gyroscope, and the coupling is directly related to the processing error. This paper introduces the structure and principle of a monolithic tri-axis micro-electromechanical gyroscope, establishes a dynamic coupling model, and studies the mechanical coupling problem caused by beam width errors. The finite element analysis tool was used to simulate the harmonic response of the gyroscope structure with beam width error. The driving-to-sensing and sensing-to-sensing coupling characteristics, the equivalent coupling angular rate of the driving mode to each sensing mode, and the cross-coupling coefficients between the sensing modes are investigated. The coupling error under unit beam width error are obtained and can be used as a reference for the structural design of the single-chip tri-axis gyroscope and the precision requirements for processing.
Development and experimental research of a test bench for sliding friction and bending fatigue
Authors: Yan Yutao , Gao Lianqi , Liu Zhenyu , Zhang Zhao
Published: September 2020

In order to research the fatigue damage characteristics of components under the coupling of sliding friction and bending fatigue. A test bench of the coupling of sliding friction and bending fatigue was developed based on the analysis of the principle of bending fatigue and friction experiment. The test bench mainly includes drive module, load application module, data collection and processing module. The single sliding friction test, single bending fatigue test, coupling test of sliding friction and bending fatigue can be carried out by this test bench. The three functions of test bench were carried out by 45steel experiment. The rationality and validity of the test bench were well verified by experimental measurement. The results show that the variation of life curve of coupling of sliding friction and bending fatigue is consistent with that of standard rotary bending fatigue life curve. The fatigue life of specimens is reduced on account of the effect of sliding friction. Under the low bending load, the influence of sliding friction effect on fatigue life is more significant. The fracture has typical characteristics of fatigue striations and dimples morphology.
Design of a side-feed rectangular waveguide helical array antenna with fan-beam radiation characteristics
Authors: Wu Donghua , Liu Xiankai , Luan Jin , Jiang Fujie , Tian Yi , E Yungang
Published: September 2020

In the millimeter wave train-ground communication system of high-speed maglev train, train-mounted antennas are required to have the characteristics of miniaturization, wide band, circular polarization, and fan-beam radiation. A side-feed rectangular waveguide helical array antenna is designed to meet these requirements in this paper. Short axial-mode helical antenna which has compact structure and circularly polarized radiation characteristics is used as the unit antenna. To realize fan-beam radiation characteristics, this array is composed of 2×15 unit antennas. All elements are fed by a rectangular waveguide which is divided into two rectangular waveguides from the side direction of the antenna. By properly designing the length of the coupling probe in the feed system, an equal excitation amplitude distribution can be realized for all unit antennas. The radiation phase of the unit antenna can be adjusted by rotating the helix arounding its axis to realize in-phase radiation of all elements. An array antenna with a center frequency of 38.0 GHz was designed through simulation. Simulation results show that the antenna has a gain of 22.1dB, an axial ratio of 2.09dB, an elevation plane beam width of 4.4°, an azimuth plane beam width of 30.1° at 38.0GHz. In the band of 37.0-39.0GHz, the reflection coefficient of this antenna is less than -15dB, the antenna gain is greater than 21.5dB and the axial ratio is less than 2.0dB which meet the design requirements of train-mounted antenna in the millimeter wave train-ground communication system.
Low-voltage distribution network topology verification method based on Revised Pearson correlation coefficient
Authors: Lou Bing , Li Cailong , Deng Jun , Zhu Linjie , Yang Cong , Chen Wujun
Published: September 2020

Due to the high cost and low real-time reliability of low-voltage distribution network topology checking by manual field verification, an online verification method based on revised Pearson correlation coefficient with error expectation values and KNN algorithm is proposed. Firstly, the Pearson correlation coefficient with error expectation values is used to judge the similarity between the user’s voltage curve and the transformer substation voltage curve, then the user with incorrect household relationship is found to perform re-verification. For performing re-verification, the user sample set is generated based on the data of GIS system and the Technical Guidelines for Distribution Network Planning and Design, and the K-Nearest Neighbor (KNN) algorithm is used to find out the correct station to which area the user belongs. Finally, based on the results of the manual field verification, the correctness of the algorithm verification is judged.
Analysis and implementation of SDH protocol in 10Gbps POS signal
Authors: Wei Ying , Huang Jiawei , Ling Liuyi
Published: September 2020

The data transmission network based on synchronous digital Hierarchy (SDH) can fundamentally solve the problems of capacity, quality, network management, security and so on in the network transmission of IP services. POS (Packet Over SDH) technology is a way to implement IP service in SDH data transmission network. An analytical solution of SDH protocol with Stratix5 FPGA as the core is studied. According to the SDH standard defined by ITU-T, the analytical circuit of SDH protocol in 10Gbps POS signal is designed on FPGA. The circuit is divided into data receiving module, line overhead module, channel spending module and status register output module, to complete data receiving, information extraction, and output of state information and net load data. The results of functional simulation and board level test show that the scheme is accurate, efficient and consistent with the standard, which can provide some reference value for the development of SDH technology.
Design and implementation of a security system based on ADSL access technology
Authors: Zhao Qiuying , He Huiwen , Chuai Yunzhi , Huang Hui , Huang Yinan
Published: September 2020

Taking the network switching equipment and the microcontroller as the core, a security system based on ADSL access technology is designed with the embedded method. The structure and communication mode of the security system are studied from three aspects: network switching equipment configurations, network communication module design of uplink equipment and communication module design of ADSL access equipment. The system can establish security monitoring points on existing telephone lines, which can not only meet the security protection requirements of high bandwidth, long transmission distance and information security, but can also reach the level of several kilometres. Furthermore, it can greatly reduce construction costs and operation costs of security system, and effectively realize the logistic support ability of security system.
AC sampling method based on improved half-wave Fourier algorithm
Authors: Mu Yuzhuang , Cao Hanwen , Liu Jieyu
Published: September 2020

This paper analyses the hardware structure of AC sampling measurement system and the basic principle of half wave Fourier algorithm in AC sampling measurement device. The hardware structure of AC sampling system is introduced. At the same time, the half-wave Fourier algorithm is improved. The improved half-wave Fourier algorithm can eliminate the error caused by the attenuation of aperiodic components. The accuracy of AC sampling is greatly enhanced. Finally, by comparing the amplitude and phase Angle errors calculated by the algorithms, the ability of the new algorithm to eliminate errors is proved.
Faults analysis of lightning stroke-caused flashover in 220 kV double-circuit transmission lines on the same tower
Authors: Zhou Luyao , Shen Jian , Liu Haojun , Wu Min , Wang Shaohua , Zhang Jichuan
Published: September 2020

In this paper, four-phase simultaneous lightning stroke-caused faults have been analysed, which occurred in double-circuit transmission lines on the same tower. According to the fault patrol circumstance, lightning information data, fault recording imformation, ATP-EMTP transient simulation analysis, it can be determined that the four-phase flashover faults were caused by backflashover. The specific process was: lightning stroke top or ground line of 75# tower. The lightning current was shunted by the ground wire and the tower, and was injected into the earth through the grounding device, cause high electric potential to rise on the top of 75# tower, and backflashover overvoltage formed across the insulators of phase B and phase C, leading to insulators flashover and simultaneous trip-out.
Design of power parameter monitor system based on Android mobile phone
Authors: Xie Honghu , Shao Hangjun , Chen Qiong
Published: September 2020

With the continuous development of power technology, real-time and accurate monitoring of power parameters in the power grid to ensure safe and stable operation of power transmission has become a hot topic of research today. The power parameter measuring instrument can realize multifunctional detection, the overall design and the combination of hardware technology and software technology, connect the mobile phone APP and hardware through WiFi transmission, and display the transmission data in real time on the smart phone terminal. Select STM32F103 as the microprocessor, adopt software synchronous sampling method, control 16-bit high-precision AD conversion chip ADS8556 for AD sampling, and then process the data by discretization method and FFT harmonic analysis algorithm, and finally send the data to The display on the Android mobile phone can realize the measurement of single-phase AC voltage and current RMS value, active power, power factor, frequency and other power parameters, and has a harmonic analysis function. The measurement data is displayed by the smartphone terminal. Tested by a test platform composed of BD-3D multi-function calibrator, the results show that its performance indicators meet the design requirements.
Study of Coal-to-Electricity Project influences on electric distribution systems in North Hebei Province in China
Authors: Zhao Min , Li Shunxin , Qin Lihan , Lyu Xin , Chen Xiangyu , Xiao Dong , Ding Jianmin , Li Xiaorong , Liu Li , Quan Luyao
Published: September 2020

Coal-to-Electricity Projects are being carried on in North China in order to reduce air pollution. These projects have brought many challenges to present electric distribution networks. Therefore, this paper focuses on how the practical electric distribution systems act facing a large quantity of electric heating integration and how to improve the behaviours. Field researches are conducted covering all cities in North Hebei Province. The current problems in planning, operation and investment of the power distribution networks supporting Coal-to-Electricity Projects are founded, and the reasons are analysed. The suggestions on the above three aspects are put forward accordingly. Case study on the distribution system in Xianghe County is conducted, and the effectiveness of the proposed approaches are verified. This study may give reference on Coal-to-Electricity related electric distribution work for other places and for the future, and also guide practical planning, operation and investment of power distribution systems on special issues.
Optimized design of DC shielding fittings for ±800kV UHV converter station
Authors: Zhang Wei , Yang Guohua , Wang Wenhao , Li Junhui , Fu Jianghao , Li Yongjie , Gao Ronggang
Published: September 2020

This paper studies the structure of the shielding device of DC device in the UHV converter station. Through simulation analysis, the electric field distribution on the surface of the shielding device is calculated to find the factors that affect the maximum field strength and the maximum electric field of the shielding device at different opening sizes and flange radius. By optimizing the structure and using a lantern-shaped shielding device, the maximum electric field strength on the surface of the shielding device of the same size can be reduced by more than 15%. The research of this project is of guiding significance for the design of shielding devices of UHV DC engineering in high altitude areas, and of great significance for promoting the progress and development of UHV DC transmission technology.
Simultaneous measurement of target distance and azimuth in four quadrant detection
Authors: Sun He , Zhang Yanmei , Li Huan
Published: September 2020

Realize the synchronous solution of target azimuth information and distance information in narrow pulse laser high-speed detection process to improve the time efficiency of detection system. A high-speed analog-to-digital (A/D) sampling chip, field-programmable gate array (FPGA) and related hardware circuit are used to establish a high-speed sampling and signal processing hardware system by performing related program configuration on each chip. Related algorithms such as pulse laser ranging method and azimuth resolution method based on four-quadrant detector are applied. At the same time, the denoising method based on Gauss white noise is adopted. Related simulation experiments and measured experiments are carried out. The simulation and experimental results show that the system realizes the synchronous solution of target azimuth information and distance information during the narrow pulse laser high-speed detection process, in which the distance error is not more than 1% and the azimuth error is not more than 5% and improve resource utilization rate.
On-line charging and discharging control of lithium ion battery
Authors: Wang Hong , Huang Bin , Zhang Wenhua , Zheng Mingcai , Luo Zhijun , Yin Qiang
Published: September 2020

In order to use lithium battery as energy storage device in DC operating power supply system, and optimize the performances of lithium ion battery such as efficiency, etc., an on-line charging and discharging control scheme for lithium ion battery in DC operating power supply is proposed. Firstly, the internal equivalent state of lithium ion battery is estimated by the output voltage and current of lithium ion battery. Secondly, the expected charging and discharging state and current value of lithium ion battery is determined by the internal equivalent state of lithium ion battery. Finally, the output voltage of AC/DC converter is adjusted according to the internal equivalent state of lithium ion battery and the expected charging and discharging state and current value. The actual charging and discharging current of lithium ion battery is forced to tend to the expected current value, so as to optimize the performances of lithium ion battery. Theoretical analysis and case study show that the scheme is feasible.