bluuebunny/crossref_metadata_2025 huggingface dataset:
Piston driven converging shock waves in nonideal magnetogasdynamics of variable density
Authors: Chauhan Antim , Arora Rajan , Tomar Amit
Published: November 2021

In this article, we analyze an imploding strong shock wave problem collapsing at the axis of cylindrical piston filled with a nonideal gas of nonuniform density that is decreasing toward the axis of symmetry according to a power law. The magnetic field is considered to be present in the axial direction, and the electrical resistance is assumed to be zero. The perturbation series technique applied to the system of hyperbolic partial differential equations governing the one-dimensional adiabatic cylindrically symmetric flow of a nonideal gas in the presence of an axial magnetic field provides us a global solution and also recovers Guderley's local solution, which holds only in the neighborhood of shock collapse. All possible similarity exponents and corresponding amplitudes are found by expanding all the flow variables and shock location in powers of time. A comparison has been made between the computed values of similarity exponents with published results in the literature, and the results are in good agreement. The flow parameters and shock position have been analyzed graphically.
Enhanced van der Waals epitaxy of germanium by out-of-plane dipole moment induced from transferred graphene on TiN/AlN multilayers
Authors: Wang Xuejing , Kim Yeonhoo , Baldwin Jon K. , Jones Andrew C. , Jeong Jeeyoon , Kang Kyeong Tae , Chen Aiping , Yoo Jinkyoung
Published: November 2021

Recent advances in 3D/2D heterostructures have opened up tremendous opportunities in building highly flexible and durable optoelectronic devices. However, the inherit lack of interfacial bonding and low surface energy of van der Waals surfaces limit the nucleation and growth of 3D materials. Enhancing wettability by providing a porous buffer is effective in growing compound semiconductors on graphene while van der Waals epitaxy of Ge remains challenging. Here, the nucleation of Ge has been significantly improved from an islanded mode to granular modes by using a TiN/AlN multilayered buffer prior to Ge/graphene integration. Highly textured Ge growth with dominating (111), (220), and (311) peaks are identified by x-ray diffraction. The microstructure of the buffer TiN/AlN demonstrates a polycrystalline quality with clean interfaces between each interlayer and the substrate. Kelvin probe force microscopy measurements along the lateral TiN/AlN interface identify a potential drop corresponding to the AlN phase. This contact potential difference between TiN and AlN is the key in generating the out-of-plane dipole moment that modifies the surface energy of the monolayer graphene, resulting in enhanced wettability of the Ge adatoms nucleated on top. Surface dipole induced nucleation of 3D semiconductor thin films on 2D materials via the proper design of buffer layer is fundamentally important to enhance the 3D/2D growth toward flexible optoelectronic applications.
Enhanced spin–orbit torque in Ni81Fe19/Pt bilayer with NdNiO3 contact
Authors: Jeong Seyeop , Lee Jongmin , Lee Soogil , Park Jungmin , Lee Donghyeon , Jeong Jimin , Jang Heechan , Park Eunkang , Jo Younghun , Lee Nyun Jong , Kim Kyoung-Whan , Park Byong-Guk , Lee Sanghan , Kim Tae Heon , Kim Sanghoon
Published: November 2021

Spin orbit torque (SOT) is essential to magnetization modulation in various ferromagnet/non-magnet bilayers. In this study, we demonstrated that SOT can be enhanced in a hybrid system composed of a perovskite oxide NdNiO3 (NNO) and a Ni81Fe19/Pt bilayer. We also find that the SOT enhancement might be attributed to spin absorption at the interface between the NNO and Ni81Fe19 layers. Our findings suggest that metal-oxide hybrid structures can be promising systems for the development of efficient spin–orbitronic devices.
Role of oxygen diffusion in the dislocation reduction of epitaxial AlN on sapphire during high-temperature annealing
Authors: Cancellara Leonardo , Markurt Toni , Schulz Tobias , Albrecht Martin , Hagedorn Sylvia , Walde Sebastian , Weyers Markus , Washiyama Shun , Collazo Ramon , Sitar Zlatko
Published: November 2021

Recovery of epitaxial AlN films on sapphire at high temperatures is now an established process to produce pseudo-substrates with high crystalline perfection, which can be used to grow epitaxial structures for UV-light-emitting devices. To elucidate the elementary mechanisms taking place during the thermal treatment of MOVPE-grown films, we studied as-grown and annealed samples combining transmission electron microscopy techniques and secondary ion mass spectrometry (SIMS). By using SIMS, we find a temperature-dependent increase in the overall oxygen content of the films, which cannot be explained quantitatively with either simple bulk or pure pipe-diffusion from the sapphire substrate. Instead, we propose a lateral outdiffusion from the dislocation cores to explain qualitatively and quantitatively the presence of observed oxygen concentration plateaus. Based on the formation enthalpy of various atomic defects and complexes found in literature, we conclude that the di-oxygen/aluminum vacancy complex (VAl–2ON) is the dominant point defect controlling the annealing process. The formation of this defect at high temperatures promotes a dislocation core climb process, which causes the annihilation/fusion of the threading dislocation segments.
Analysis of semi-insulating carbon-doped GaN layers using deep-level transient spectroscopy
Authors: Wang Hongyue , Hsu Po-Chun (Brent) , Zhao Ming , Simoen Eddy , Gendt Stefan De , Sibaja-Hernandez Arturo , Wang Jinyan
Published: November 2021

Electrically active defects in carbon-doped GaN layers were studied with a metal/carbon-doped GaN (GaN:C)/Si-doped GaN (GaN:Si) MIS structure. The GaN:C layers were grown with three different carbon doping concentrations (NC). A semi-vertical metal/semi-insulator/n-type semiconductor (MIS) device was fabricated to perform deep-level transient spectroscopy (DLTS) measurements. Two electron traps E1 and E2 with energy level at EC − (0.22–0.31) eV and EC − (0.45–0.49) eV were observed. E1 and E2 are associated with a nitrogen vacancy VN-related defect in the strain field of extended defects and a nitrogen antisite defect, respectively. By changing the reverse bias voltage of the DLTS measurement, the location and relative defect concentration of the E1 and E2 traps could be verified. A dominant electron trap E3 with an unusual capture cross section was only observed in devices with an NC = 2 × 1019 cm−3 GaN:C layer. This may charge carriers from a defect band and lead to the charge redistribution in the GaN:C layer when forward biased. A hole trap H1 with energy level at EV + 0.47 eV was found for the pulse bias in the forward ON-state. H1 is suggested to correspond with the CN induced 0/+ donor level. By analyzing the schematic band diagrams across the MIS structure, the carrier transport and defect charging mechanisms underlying the DLTS transient measurements are illustrated. The identification of the trap states in the carbon-doped GaN with different NC gives further understanding on the carbon doping impact on electric characteristics of GaN power devices made on Si substrates.
Perovskite luminescent solar concentrators for photovoltaics
Authors: Xia Pengfei , Xu Shuhong , Wang Chunlei , Ban Dayan
Published: November 2021

As large-area photon collection devices designed for photovoltaics, luminescent solar concentrators (LSCs) have been proposed for more than 40 years. In recent years, the perovskite-based LSCs have received much interest for the convenient preparation process and low cost along with high quantum yields of perovskite luminophores. However, optical losses, such as non-radiative recombination loss and reabsorption loss, seriously impair the performance of LSCs and further impede the commercialization of such promising photovoltaic devices. Various strategies, such as increasing the Stokes shift and defect passivation, have been implemented to enhance the optical performance in perovskite-based LSCs. Here, we appraise the applications of perovskite luminophores in LSCs and review the typical preparation method of perovskite-based LSCs. The state-of-the-art solutions are presented to address the optical losses, leading to the demonstration of enabling high-performance perovskite-based LSCs.
The interplay between laser focusing conditions, expansion dynamics, ablation mechanisms, and emission intensity in ultrafast laser-produced plasmas
Authors: Kautz Elizabeth J. , Senor David J. , Harilal Sivanandan S.
Published: November 2021

The interplay between ultrafast laser focusing conditions, emission intensity, expansion dynamics, and ablation mechanisms is critical to the detection of light isotopes relevant to nuclear energy, forensics, and geochemistry applications. Here, we study deuterium (2Hα) emission in plasmas generated from femtosecond laser ablation of a Zircaloy-4 target with a deuterium concentration of ≈37 at. %. Changes in emission intensity, plume morphology, crater dimensions, and surface modifications were investigated for varying focusing lens positions, where the laser was focused behind, at, and in front of the target. Spatially resolved optical emission spectroscopy and spectrally integrated plasma imaging were performed to investigate emission spectral features and plume morphology. Laser ablation crater dimensions and morphology were analyzed via optical profilometry and scanning electron microscopy. The 2Hα emission intensity showed significant reduction at the geometrical focal point or when the focal point is in front of the target. For all laser spot sizes, a two-component plume was observed but with different temporal histories. At the best focal point, the plume was spherical. When the laser was focused behind the target, the plume was elongated and propagated to farther distances than for the best focal position. In contrast, when the laser was focused in front of the target, filaments were generated in the beam path, and filament-plasma coupling occurred. By focusing the laser behind the target, the amount of material removal in the laser ablation process can be significantly reduced while still generating a plasma with a sufficient 2Hα emission signal for analysis.
Doping Rh into TiO2 as a visible-light-responsive photocatalyst: The difference between rutile and anatase
Authors: Wang Jiaming , Liu Kaiwei , Zhang Boyang , Qiu Yaru , Xiang Yao , Lin Wenrui , Yang Bo , Li Bin , Ma Guijun
Published: November 2021

Incorporation of alien atoms into TiO2 is an effective means to extend its light absorption edge for utilizing solar energy sufficiently. Herein, taking rutile and anatase as precursors, respectively, Rh element was attempted to dope into TiO2 by an immersion-calcination process. The results showed that Rh species were readily immerged in the crystal structure of rutile at a temperature above 973 K, while they were constantly positioned on the surface of anatase in a separate form of Rh2O3 nanoparticle even at 1173 K. Density functional theory simulations revealed that the Rh-rutile sample owned a higher negative formation energy than Rh-anatase. Under visible light irradiation and in the presence of ascorbic acid as a sacrificial reagent, photocatalytic hydrogen evolution activity over Rh-doped rutile was about 50 times of that over Rh-doped anatase powders. The present work demonstrates the roles of the crystal phase in atom doping that eventually dominates photocatalytic activities.
A pathway to highly conducting Ge-doped AlGaN
Authors: Bagheri Pegah , Kim Ji Hyun , Washiyama Shun , Reddy Pramod , Klump Andrew , Kirste Ronny , Mita Seiji , Collazo Ramón , Sitar Zlatko
Published: November 2021

Ge doping in AlGaN was studied over a wide dopant concentration range. For high Ge concentrations, the formation of VIII–nGeIII was determined to be the main point defect limiting the conductivity. It was shown that the complex formation could be suppressed by controlling chemical potentials during growth, leading to a higher maximum achievable carrier concentration and selective stabilization of a certain complex type. Chemical potential of the growth species was varied by changing the V/III ratio and growth temperature. Free carrier concentrations as high as 4 × 1019 cm−3 were achieved in Al0.4Ga0.6N:Ge grown on sapphire substrates under “metal-rich” conditions. The ability to control the onset of self-compensation and to stabilize a certain charge state of the compensating defect is of great technological importance for application of AlGaN in various devices.
Gated reactions in discrete time and space
Authors: Scher Yuval , Reuveni Shlomi
Published: November 2021

How much time does it take for two molecules to react? If a reaction occurs upon contact, the answer to this question boils down to the classic first-passage time problem: find the time it takes for the two molecules to meet. However, this is not always the case as molecules switch stochastically between reactive and non-reactive states. The reaction is then said to be “gated” by the internal states of the molecules involved, which could have a dramatic influence on kinetics. A unified, continuous-time, approach to gated reactions on networks was presented in a recent paper [Scher and Reuveni, Phys. Rev. Lett. 127, 018301 (2021)]. Here, we build on this recent advancement and develop an analogous discrete-time version of the theory. Similar to continuous-time, we employ a renewal approach to show that the gated reaction time can always be expressed in terms of the corresponding ungated first-passage and return times, which yields formulas for the generating function of the gated reaction-time distribution and its corresponding mean and variance. In cases where the mean reaction time diverges, we show that the long-time asymptotics of the gated problem is inherited from its ungated counterpart. However, when molecules spend most of their time non-reactive, an interim regime of slower power-law decay emerges prior to the terminal asymptotics. The discretization of time also gives rise to resonances and anti-resonances, which were absent from the continuous-time picture. These features are illustrated using two case studies that also demonstrate how the general approach presented herein greatly simplifies the analysis of gated reactions.
Magnetotransport in magnetic junctions based on tilted Weyl semimetals
Authors: Xuan Mei Xiao , Chen Mingxing , Li Hai
Published: November 2021

We theoretically investigate the magnetotransport properties in magnetic junctions based on tilted Weyl semimetals and concentrate on the manifestations of the tilted effect in the differential conductance. Since the projection of the Fermi surface normal to the current direction can be enlarged by the tilted effect, the differential conductance is enhanced by increasing the tilting parameter. Moreover, due to the helical textures of Weyl fermions, the enhancement of differential conductance is robust against interfacial imperfections.
Probing functional conformation-state fluctuation dynamics in recognition binding between calmodulin and target peptide
Authors: Jaiswal Sunidhi , He Yufan , Lu H. Peter
Published: November 2021

Conformational dynamics play a crucial role in protein functions. A molecular-level understanding of the conformational transition dynamics of proteins is fundamental for studying protein functions. Here, we report a study of real-time conformational dynamic interaction between calcium-activated calmodulin (CaM) and C28W peptide using single-molecule fluorescence resonance energy transfer (FRET) spectroscopy and imaging. Plasma membrane Ca-ATPase protein interacts with CaM by its peptide segment that contains 28 amino acids (C28W). The interaction between CaM and the Ca-ATPase is essential for cell signaling. However, details about its dynamic interaction are still not clear. In our current study, we used Cyanine3 labeled CaM (N-domain) and Dylight 649 labeled C28W peptide (N-domain) to study the conformational dynamics during their interaction. In this study, the FRET can be measured when the CaM–C28W complex is formed and only be observed when such a complex is formed. By using single-molecule FRET efficiency trajectory and unique statistical approaches, we were able to observe multiple binding steps with detailed dynamic features of loosely bound and tightly bound state fluctuations. The C-domain of CaM tends to bind with C28W first with a higher affinity, followed by the binding of the CaM N-domain. Due to the comparatively high flexibility and low affinity of the N-domain and the presence of multiple anchor hydrophobic residues on the peptide, the N-domain binding may switch between selective and non-selective binding states, while the C-domain remains strongly bound with C28W. The results provide a mechanistic understanding of the CaM signaling interaction and activation of the Ca-ATPase through multiple-state binding to the C28W. The new single-molecule spectroscopic analyses demonstrated in this work can be applied for broad studies of protein functional conformation fluctuation and protein–protein interaction dynamics.
An improved study of HCO+ and He system: Interaction potential, collisional relaxation, and pressure broadening
Authors: Tonolo F. , Bizzocchi L. , Melosso M. , Lique F. , Dore L. , Barone V. , Puzzarini C.
Published: November 2021

In light of its ubiquitous presence in the interstellar gas, the chemistry and reactivity of the HCO+ ion requires special attention. The availability of up-to-date collisional data between this ion and the most abundant perturbing species in the interstellar medium is a critical resource in order to derive reliable values of its molecular abundance from astronomical observations. This work intends to provide improved scattering parameters for the HCO+ and He collisional system. We have tested the accuracy of explicitly correlated coupled-cluster methods for mapping the short- and long-range multi-dimensional potential energy surface of atom–ion systems. A validation of the methodology employed for the calculation of the potential well has been obtained from the comparison with experimentally derived bound-state spectroscopic parameters. Finally, by solving the close-coupling scattering equations, we have derived the pressure broadening and shift coefficients for the first six rotational transitions of HCO+ as well as inelastic state-to-state transition rates up to j = 5 in the 5–100 K temperature interval.
Fast quasi-centroid molecular dynamics
Authors: Fletcher Theo , Zhu Andrew , Lawrence Joseph E. , Manolopoulos David E.
Published: November 2021

We describe a fast implementation of the quasi-centroid molecular dynamics (QCMD) method in which the quasi-centroid potential of mean force is approximated as a separable correction to the classical interaction potential. This correction is obtained by first calculating quasi-centroid radial and angular distribution functions in a short path integral molecular dynamics simulation and then using iterative Boltzmann inversion to obtain an effective classical potential that reproduces these distribution functions in a classical NVT simulation. We illustrate this approach with example applications to the vibrational spectra of gas phase molecules, obtaining excellent agreement with QCMD reference calculations for water and ammonia and good agreement with the quantum mechanical vibrational spectrum of methane.
Understanding fire regimes in Europe
Authors: Galizia Luiz Felipe , Curt Thomas , Barbero Renaud , Rodrigues Marcos
Published: November 2021

Wildland fire effects are strongly associated with fire regime characteristics. Here, we developed the first European pyrogeography based on different fire regime components to better understand fire regimes across the continent. We identified four large-scale pyroregions: a non-fire-prone (NFP) pyroregion featuring nominal fire activity across central and northern Europe; a cool-season fire (CSF) pyroregion scattered throughout Europe; a fire-prone (FP) pyroregion extending mostly across southern Europe; and a highly fire-prone (HFP) pyroregion spanning across northern Portugal, Sicily, and western Balkans. Land cover analysis indicates that pyroregions were first shaped by vegetation and then by anthropogenic factors. On interannual timescales the spatial extent of pyroregions was found to vary, with NFP showing more stability. Interannual correlations between climate and burned area, fire frequency, and the length of fire period exhibited distinct patterns, strengthening in fire-prone pyroregions (FP and HFP) and weakening in NFP and CSF. Proportion of cool-season fires and large fires were related to fuel accumulation in fire-prone pyroregions. Overall, our findings indicate that such a pyrogeography should allow a more accurate estimate of the effects of climate on fire regimes while providing an appropriate framework to better understand fire in Europe.
Host genotype structures the microbiome of a globally dispersed marine phytoplankton
Authors: Ahern Olivia M. , Whittaker Kerry A. , Williams Tiffany C. , Hunt Dana E. , Rynearson Tatiana A.
Published: November 2021

Significance

Microscale interactions between marine phytoplankton and their bacterial microbiomes can influence ecosystem functioning and global biogeochemical cycling through complex exchanges of metabolites and sophisticated ecological processes. Previous investigation of the phytoplankton microbiome has not focused on the role of a host’s underlying genetic background. Through examination of a single phytoplankton species’ microbiome across the global ocean, we found that host genotype strongly influenced microbiome community composition, with associations that potentially persist across generations and ocean basins but assemble rapidly (within days). The long-term association of microbiomes with host genetic background could explain the evolution and maintenance of intricate phytoplankton–bacteria interactions.
Embodied cognition in the booth
Authors: Martín de León Celia , Fernández Santana Alba
Published: November 2021

From an enactivist perspective, cognition can be described as embodied, since it is determined by our bodily, multisensory, affective interaction with the environment, in particular by our social interaction. In recent years, interpreting has been defined as a multimodal, embodied cognitive activity of inter-lingual mediation, and research on gestures in conference interpreting has found that simultaneous interpreters, although not visible for their audience, do gesture in the booth. However, gestures in interpreting are yet understudied. This paper presents an exploratory, in-depth descriptive study with the aim of generating hypotheses about the cognitive functions of gestures in simultaneous interpreting. To this end, we investigate the different types of gesture that emerge throughout a whole process of simultaneous interpreting, in conjunction with the concurrent speech, the interpreter’s interaction with her environment and her own description of her production of mental images and gestures. The research question guiding our investigation is: What functions do the different types of gestures play in the interpreting process? The results suggest that, in the analyzed material, referential gestures tend to support the construction of meanings, while the main role of pragmatic gestures consists in helping to manage the progress of the interpreting process.
Towards a methodological toolset for the psycholinguistics of translation
Authors: Jacob Gunnar , Schaeffer Moritz , Oster Katharina , Hansen-Schirra Silvia , Allen Shanley E. M.
Published: November 2021

The manuscript provides readers with a basic methodological toolset for experimental psycholinguistic studies on
translation. Following a description of key methodological concepts and the rationale behind experimental designs in
psycholinguistics, we discuss experimental paradigms adopted from bilingualism research, which potentially constitute a
methodological foundation for studies investigating the psycholinguistics of translation. Specifically, we show that
priming paradigms possess several inherent advantages which make them particularly suitable for research on
translation. The manuscript critically discusses key methodological problems associated with such paradigms and illustrates the
opportunities they may offer for translation research, concludes with a review of past and current translation process research
highlighting ways in which these can contribute to the issues raised by cross-linguistic priming studies.
Investigating how we read translations
Authors: Walker Callum
Published: November 2021

Since its inception, Translation Studies has hinged on theoretical concepts of effects and reception, with various reader-oriented notions such as equivalent effect,skopos, acceptability and adequacy, and user-centredness, to name but a few, having pervaded the discipline for decades. Despite this preoccupation with the phenomenology of translations, we still know very little about how translations are actually experienced –writtentranslations especially. This article calls for an expansion of research into the reception and experience of source texts and their translations, reviewing the opportunities afforded by recent technological developments in eye-tracking, galvanic skin response sensors, echocardiogram monitors, and other multi-sensory devices. Using a short case study, a number of research questions and an outline of an experimental method are proposed to contrast the reading experience of two translations of the same source text, serving as a prompt for future research of this kind. By drawing inspiration from the few existing examples of research in this incipient paradigm and the considerations offered in the example, this article aims to stimulate future research to explore the vast untapped potential in this area and to arrive at a better understanding of the effects that different translation approaches yield and the potential variation in effects between source and target text.
A high OXPHOS CD8 T cell subset is predictive of immunotherapy resistance in melanoma patients
Authors: Li Chuan , Phoon Yee Peng , Karlinsey Keaton , Tian Ye F. , Thapaliya Samjhana , Thongkum Angkana , Qu Lili , Matz Alyssa Joyce , Cameron Mark , Cameron Cheryl , Menoret Antoine , Funchain Pauline , Song Jung-Min , Diaz-Montero C. Marcela , Tamilselvan Banumathi , Golden Jackelyn B. , Cartwright Michael , Rodriguez Annabelle , Bonin Christopher , Vella Anthony , Zhou Beiyan , Gastman Brian R.
Published: November 2021

Immune checkpoint inhibitor (ICI) therapy continues to revolutionize melanoma treatment, but only a subset of patients respond. Major efforts are underway to develop minimally invasive predictive assays of ICI response. Using single-cell transcriptomics, we discovered a unique CD8 T cell blood/tumor-shared subpopulation in melanoma patients with high levels of oxidative phosphorylation (OXPHOS), the ectonucleotidases CD38 and CD39, and both exhaustion and cytotoxicity markers. We called this population with high levels of OXPHOS “CD8+ TOXPHOS cells.” We validated that higher levels of OXPHOS in tumor- and peripheral blood–derived CD8+ TOXPHOS cells correlated with ICI resistance in melanoma patients. We then developed an ICI therapy response predictive model using a transcriptomic profile of CD8+ TOXPHOS cells. This model is capable of discerning responders from nonresponders using either tumor or peripheral blood CD8 T cells with high accuracy in multiple validation cohorts. In sum, CD8+ TOXPHOS cells represent a critical immune population to assess ICI response with the potential to be a new target to improve outcomes in melanoma patients.
An on-chip test structure to measure the Seebeck coefficient of thermopile sensors
Authors: Huang Peng , Fu Jianyu , Lu Yihong , Liu Jinbiao , Zhang Jian , Chen Dapeng
Published: November 2021

Thermopile sensors have a wide range of applications in consumer and industry. Seebeck coefficient is a basic thermal parameter of thermopile sensors. Extracting the Seebeck coefficient of both materials and thermocouple in thermopile sensors is of great importance. In this work, an on-chip test structure is designed. It consists of a substrate, a framework, supporting legs and a sensitive region which has a resistor serving as both heater and temperature detector. A set of on-chip test structures are fabricated along with a thermopile sensor. Its measurement results are analyzed and compared with apparatus measurement results. These results are consistent with each other, and the validity of structure is verified.
Double Power Supplies and Cross-zero Clocks Lead to Low Noises and High Efficiency in Digital Integrated Circuits
Authors: Wu Tao
Published: November 2021

Double power supplies are widely used in analog integrated circuits for the sake of power export and dynamic ranges. By contrast, single power supply and the ground line are regular in digital integrated circuits so far. In this paper, it is shown that double power supplies with cross-zero clocks help decrease the power consumption and noises in digital integrated circuits. They are firstly explained in frequency domain and then by a three-level energy system.
Practical Time Optimization of DSP Program for High-frequency Applications
Authors: Xun Zhuyu , Ding Hongfa , He Zhou
Published: November 2021

The rapid development of the high frequency power conversion techniques makes great demands on the methods that can reduce the execution time of the program effectively. This paper is aiming at reducing the execution time of the program in several aspects such as sampling, complex expressions, and so on. As one of the most widely applied methods, reducing the execution time of the program at the cost of the memory space is adopted in this paper. Furthermore, in order to confirm the feasibility and superiority of programs that are proposed in this paper, they are compared with other programs that can realize the same function in terms of the execution time.
Fault Diagnosis of Wind Turbine Generator System Based on PMI-LSSVM
Authors: Zhang Wei , Zhang Zhizhi , Yao Qi , Zhang Xiao , Liu Di , Liu Zesan , Meng Hongmin , Qin Weiming
Published: November 2021

Considering the multi-source wind power information such as wind speed, rotation speed, spindle horizontal and vertical vibration, a fault diagnosis method of wind turbine generator system based on partial mutual information (PMI) and least squares support vector machine (LSSVM) was proposed. A large amount of data containing fault status, such as blade fault, converter fault, generator fault, pitch bearing fault and yaw system fault, was analyzed. The PMI method was used to screen the characteristic parameters of the operation state of the wind turbine to identify the fault of the unit. The characteristic parameters of the wind turbine in various states were trained by LSSVM method to establish the mapping relationship between the parameter vectors of different characteristics and the fault types, so as to achieve the purpose of fault diagnosis. Besides, the different fault history data of wind turbine was used to test the fault model performance. The results compared with artificial neural network (ANN) method showed that the proposed method had good fault recognition ability and fast operation speed, which was suitable for fault diagnosis of multibrid technology wind turbine generator system, and can meet the requirements of online fault diagnosis.
Research on the Architecture of Integrated Platform of Intelligent Substation Auxiliary Monitoring System
Authors: Yang Chuankai , Wu Jingfeng , Zhao Jiansong , Zhang Xiaolan , Li Liangshu , Mu Jianxue
Published: November 2021

For the problems existing in the current substation auxiliary monitoring system, such as various types of equipment, inconsistent standards and poor interaction, the structure design scheme of integrated platform of intelligent substation auxiliary monitoring system is proposed. The structure, function and algorithm of the system are introduced in detail. Firewall isolation technology and security partition technology are adopted to ensure the security and of the system, and give consideration to the real-time data transmission. Through the use of software bus technology, multi data fusion technology and interface standardization technology, the availability and reliability of data are effectively improved and the reliability of the system is improved. Combined with the integrated monitoring platform, the characteristics of intelligent linkage technology of main and auxiliary equipment are put forward. The intelligent linkage and unified management between auxiliary equipment is realized, which effectively improves the intelligent operation and maintenance level of substation auxiliary system.
Power System Small-signal Stability Assessment Model Based on Residual Graph Convolutional Networks
Authors: Su Yinsheng , Guo Mengxuan , Yao Haicheng , Guan Lin , Huang Jiyu , Zhu Siting , Zhong Zhi
Published: November 2021

Small-signal stability (SSA) is important to power system security. A data-driven approach is established for rapid prediction of the power system oscillation characteristics. The key of the approach is the Graph Convolution Networks (GCN) with residual mechanism, which works to aggregate features from high-dimension steady-state operation information and is denoted as ResGCN (RESidual GCN) in the paper. The residual mechanism helps to overcome the network degradation phenomenon. Both the oscillation frequency and damping ratio of multiple modes can be predicted by the proposed model. The performance of the proposed scheme as well as its adaptability to the power system topological changes is verified on the IEEE 39 Bus system.
A Joint Grid-Source Planning Method Considering Adaptability of Power System
Authors: Deng Yingying , Wang Haiyan , Liu Xu’na , Chen Bo , Yang Xinting , Chen Wenye
Published: November 2021

With the large-scale renewable energy access to the power grid, the construction and operation state of the power system have been greatly changed. Therefore, the adaptability of power system to deal with the fluctuation and uncertainty of renewable energy is of great significance to ensure the safe and stable operation of the system and promote the consumption of renewable energy. Based on the structural characteristics and operation status of the power system with high proportion of renewable energy, the adaptability index of the system construction and generators capacity is proposed, which takes into account the security, validity, stability and supply-demand balance of the power system, and comprehensively evaluates the acceptance capacity of the system to the renewable energy. On this basis, a multi-objective power system planning model based on grid-source coordination considering both economy and adaptability is established. The optimal scheme is obtained through the comprehensive decision of the optimal scheme set by the nonlinear improved principal component analysis. Finally, the effectiveness of the adaptability index and the planning model is verified by an example simulation with the improved Gaver-18 system.
An Autonomous Vibration-Sensing System for Power Transmission Lines Monitoring
Authors: Meng Qingpu , Huo Fuguang , Teng Song , Ding Zushan , Gu Tun , Cao Chuang
Published: November 2021

An autonomous vibration-sensing system including of ring magnetoelectric energy scavenger, an energy management module, a plurality of wireless acceleration sensor nodes and APP mobile terminal for power transmission lines monitoring was presented. The ring-type ferrite/piezoelectric composite with strong magnetoelectric couplings and a coil wound around it is used to scavenge the electromagnetic energy around the conductor, and the energy management module successively fulfill the functions of inductive/capacitive resonance matching, rectification and voltage stabilization and storage/release of the scavenged electric energy, and then provides driving power for signal acquisition and data transmission of 4G wireless acceleration sensor nodes. Testing results show that the collected energy can fulfill the power-supplying requirements of ADXL345, and the real-time as well as historical data curves within a specified time can be acquired through 4G and narrowband internet of things technologies.
Implementation and Verification of 5G Network Slicing for Smart Grids
Authors: Sun Lei , Wang Li , Yang Peng , Zhong Yuqing , Hong Danke , Zhang Guoyi , Zhu Hailong , Qian Peng , Li Jing
Published: November 2021

In this paper, 5G slicing networks are proposed to be deployed to address the issues associated with current communication networks in power grid systems and to enable smart grid applications. 5G slice architecture and the corresponding schemes including radio resource reservation, QoS scheduling strategy, VLAN, VPN and 5QI are applied for the access network, the transport network and the core network in the system, based on which a real 5G slicing network is implemented for smart grid applications. It is shown by field trial that the performance requirement regarding service isolation, bandwidth, delay and reliability required by various smart grid applications can be satisfied using the proposed schemes in the real system.
Optimal Operation Model of Park Integrated Energy System Considering Uncertainty of Flexible Electrical, Thermal and Gas Load
Authors: Li Peifeng , Wang Wei , Wei Jun , Li Da , Long Chuan , Chen Wenye
Published: November 2021

Flexible Load (FL) of electricity, heat and gas can improve the operation economy, flexibility and reliability of PIES. Aiming at the uncertainty of FL in the actual operation of the park integrated energy system (PIES), an optimal operation model of PIES with uncertainty of FL is proposed. Firstly, the uncertainty models of shiftable electric load and transferable load response are established, respectively. And then an adjustable heat load response model considering the uncertainty of solar radiation intensity is established. On this basis, an optimal operation model of PIES considering the uncertainty of the FL with the goal of maximizing the total revenue is constructed and is solved by the enhanced-interval linear programming method. Simulation indicate that FL can improve the operating economy of PIES and renewable energy consumption.
Multi-task Transient Contingency Screening with Temporal Graph Convolutional Network in Power Systems
Authors: Su Yinsheng , Huang Jiyu , Yao Haicheng , Guan Lin , Guo Mengxuan , Zhong Zhi
Published: November 2021

Rapid transient stability assessment (TSA) is an essential requirement for power system security. In real-world applications, transient contingency screening (TCS) applies TSA approaches to address the pre-defined contingency sets under online operation conditions. TSA by time domain simulation (TDS) is time-consuming, hence we propose a high-speed temporal graph convolutional network (TGCN) that achieves TSA decisions such that a large-scale contingency set can be scanned quickly with enough precision. Based on multi-graph inputs to reflect the transient process, the TGCN utilizes the graph convolutional network (GCN) to extract topology representations and temporal convolution (TC) layers to encode temporal relations. After above graph embedding, two downstream networks are designed for stability classification and critical generator prediction, respectively. Test results on IEEE 39 Bus system demonstrate its superiority over existing models under different operation topologies, fault locations and clearing modes.
The Electric Vehicle Routing Problem with Time Windows under Travel Time Uncertainty
Authors: Wang Dan , Zhou Hong
Published: November 2021

Due to environmental friendliness, electric vehicles have become more and more popular nowadays in the transportation system. For many express companies, it is more and more important to meet the predetermined time window of customers. The uncertainty in travel times often causes uncertain energy consumption and uncertain recharging time, thus electric vehicles may miss the time windows of customers. Therefore, this paper addresses the electric vehicle routing problem with time windows under travel time uncertainty, which aims to determine the optimal delivery strategy under travel time uncertainty. To solve this problem, a robust optimization model is built based on the route-dependent uncertainty sets. However, considering the complexity of the problem, the robust model can only solve few instances including the small number of customers. Thus, a hybrid metaheuristic consisting of the adaptive large neighborhood search algorithm and the local search algorithm is proposed. The results show that the algorithm can obtain the optimal solution for the small-sized instances and the large-sized instances.
Key Techniques of SINS/DVL Integrated Navigation System
Authors: Li Wanli , Chen Mingjian , Li Yun
Published: November 2021

Doppler Velocity Log (DVL) aided Strapdown Inertial Navigation System (SINS) is commonly used for the applications of Autonomous Underwater Vehicles (AUVs). In lack of other aiding sensors, how to maintain precise integrated navigation is still a challenge issue. In this paper, the structure and basic principles of the SINS is presented. Alignment calibration of SINS and DVL, fast in-motion alignment and data fusion are key factors which has great influence on the navigation accuracy. Research efforts taken in these fields in recent years are surveyed. This paper may provide a firm foundation for the researchers in related areas.
Effect of Dynamics Control Strategy on Performance of FSEC Racing Car
Authors: Ma Lingyue
Published: November 2021

The control strategy of driving system for the distributed electric drive DRe20 car of Tongji University DIAN Racing team is developed and optimized according to the competition rules of Formula Student Electric China (FSEC). The VI-grade and Matlab Simulink cosimulation experimental platform is established to study the effects of different dynamic control strategies, such as equal distribution, open-loop electronic differential and limited slip differential, on the performance of the DRe20 racing car. The simulation platform is also used to optimize the control algorithm and the setting of different parameters in the program, then the results of simulation analysis and optimization are applied to the actual car experiment, providing a lot of reference data for the adjustment of suspension system and electronic control system of the DRe20 car. The simulation and actual test results show that the limited slip differential control strategy we developed and optimized in 2020 can give full play to the design performance of the DRe20 car, and the comprehensive performances have been improved compared with those in previous years. The optimized dynamics control strategy has been applied to Tongji DIAN Racing car during the 2020 Formula Student Electric China competition, in which Tongji DIAN Racing Team wins the championship.
Space Layout Method for Carton Conveying System Based on SOSG Matrix
Authors: Cao Weilin , Qian Jie , Li Jie , Xu Qi , Lin Yizhen , Wang Xiang
Published: November 2021

The traditional cigarette conveying system of cigarette industry adopts a one-to-one hard connection method, which has problems such as poor spatial scalability and high equipment coupling. A spatial layout method for carton conveying system based on the SOSG (Solid Orthogonal Structure Graph) matrix is proposed. Through this method, a matrix cigarette conveying system is constructed. Compared with the traditional mode, its space utilization rate is increased by 67%, equipment coupling is reduced, and the downtime rate of carton conveying line due to the shutdown of sealing machine can be reduced from 100% to 0%.
A MBD Model-driven Automatic Generation Method of On-machine Measuring Program for CNC Machining
Authors: Zhong Wenhao , Zhai Cheng , Cao Yansheng , Wang Meiqing
Published: November 2021

Aiming at the problem that the programming of on-machine measurement in CNC machining process is heavily dependent on operators and the efficiency is lower, a MBD model-driven automatic generation method of on-machine measuring program is proposed. The characteristics of measuring program is analysed and the relationship between the parameters of measuring cycle and the features of MBD model is built. The approach of PMI (product manufacturing information) data identifying and extracting is presented. The scheme for transforming the PMI data and geometric features to measuring cycle parameters is constructed. In order to make the measuring program adapt to the change of probe position which stored in different tool magazine, the way of collecting the position automatically by OPC DA protocol is provided. On the basis of the proposed methods and approaches, an on-machine measuring program generating software system has been developed. The running result of the system is given, and the feasibility and effectiveness of the method were demonstrated.
The Research on Operation Automation Model for Information Equipment
Authors: Li Danping , Chen Zhiwen , Wang Guihua , Zhou Xiaolu , Ren Ming
Published: November 2021

Privilege control is an important problem to be solved in the operation of the intranet network of military industry. Solidifying the operation process and replacing the operation personnel with machines to complete configuration changes can reduce the frequency of manual operation by privileged personnel, thus limiting the operation privilege and improving the security of intranet network. Aiming at the high security and high efficiency requirements of operation of intranet information equipment, this paper designs an operation automation mode. Aiming at the problem that it is difficult for tools to adapt to heterogeneous equipment, this paper studies the commands adaptive technology for heterogeneous equipment based on abstract atomic operation. In addition, the model and technologies are verified by a specific scene of equipment location change. The results show that the above model and technologies achieve the goal of ensuring the security of operation and improving the efficiency of operation.
The Acquisition of Position and Orientation of the Conveyor Belt Workpiece Based on the Inter Frame Difference in ROI in Camera Video
Authors: Wang Jian , Chen Ziting
Published: November 2021

Conveyor belt transfer is a widely used transportation means in industry and agriculture, with the help of the robot arms the workpiece on the belt can be picked and placed, replacing human sorters for production lines work. The position and orientation of the workpiece are important for grabbing by the robot arms. The goal of the paper was to investigate the acquisition of the position and orientation of the conveyor belt workpiece by means of the camera video overhead looking down the belt. The proposed method is the inter frame difference in nature, using the conveyor belt background as the first frame, but the other frames were not used wholly as usually, only an ROI all around the conveyor belt in the camera video was chosen, and the inter frame difference was carried out in the ROI. The ROI was of the same width as that of the belt in the video which was known in advance, while the length of the ROI was arbitrary, so one pixel in the frame was scaled to the actual length conveniently. Every read frame behind the background was computed the difference with the background in such ROI, and the four vertexes coordinates of the rectangle workpiece image on the belt were obtained when it passed the ROI, and then the distance apart from the right belt boundary was calculated due to the proportional relation between the width of workpiece and that of the ROI. Two kind workpiece orientation on the belt toward the left and right were judged using the same obtained four vertexes coordinates by means of Euclidian length, and the tilt angle was calculated by arc tangent function in favour of two narrow sides of rectangle workpiece grab. The actual test showed that the method of obtaining the position and orientation of workpiece on the belt proposed in the paper could be realized correctly.