bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling of Contra-Rotating and Ducted Propellers via Coupling of a Vortex-Lattice with a Finite Volume Method
Authors: Gu Hua , Kinnas Spyros A.
Published: January 2022

This paper describes a general numerical method of analyzing propeller hydrodynamic performance, with emphasis on contra-rotating (CRP) and ducted propellers. The main difficulty in this analysis is the complexity of the interaction between the two blade rows, in the case of a CRP, and between the propeller and the surrounding duct, in the case of a ducted propeller. The current method couples a Vortex-Lattice Method (VIM) applied to each of the blade rows of the CRP or the propeller inside the duct, with a Finite Volume Method (FVM) based Euler solver applied to the global flow-field, in order to account for the interactions mentioned above. The VIM solver (MPUF-3A) solves for the potential flow in the vicinity of the propeller and predicts the pressures, forces and moments, and cavity patterns on the blades. The FVM solver (GBFLOW-3X/3D) converts the pressure forces on the blades to body forces inside the flow domain and then solves the Euler equations with respect to the total velocity field and pressure. By subtracting the propeller-induced velocities, from the total flow, the "effective wake" is determined. For CRPs, the "effective wake" for each blade row includes the interaction with the other blade row. For ducted propellers, the "effective wake" includes the interaction with the duct. The "effective wake" is then provided to the VIM solver for a new round of body force computation. This iterative process between the VIM and the FVM is repeated until convergence. Several validations of results from the current numerical method with those of other computational methods and with those measured in experiments are presented.
Design of an Advanced Waterjet
Authors: Facinelli William A. , Becnel Alan J. , Purnell John G. , Blumenthal Robert F.
Published: January 2022

State-of-the-art computer programs have been used to design a water jet for marine propulsion applications. The design was accomplished in an iterative process between a potential-flow design code and a folly viscous, three-dimensional computational fluid dynamics analysis program. These tools were first directed at the evaluation of three options: a single rotating blade row plus a stator; a rotating blade set consisting of main blades and splitter blades, plus a stator; and two co-rotating blade rows (an inducer and a kicker) plus a stator. In the second step of the design process, the single rotor/stator concept was optimized to maximize efficiency while matching a given design point. The resulting design is predicted to have much improved cavitation performance compared with a design accomplished with older techniques. Other advantages are reduced weight, shorter length, and lower manufacturing cost.
A Coupled RANS/VLM Approach for Multi-component Propulsor Analysis
Authors: Lee Sing-Kwan , Chen Hamn-Ching
Published: January 2022

This paper describes an ongoing effort to integrate Computational Fluid Dynamic methods into a system for predicting the performances of multi-component propulsors in a turbulent ship flow environment. These methods include a Reynolds-Averaged Navier-Stokes (RANS) code for ship turbulent flow calculations and a Vortex-Lattice Method (VLM) based program MPUF3A for sheet cavitating propeller flow analyses. The combination of these methods provides a new level of realism for modeling the flow field around a ship with thick turbulent boundary layers and multi-component propulsor/hull interaction. The bottlenecks caused by inadequate grid generation methods and a lack of code integration, which have prevented the use of these numerical methods for practical configurations in design time frame, have been substantially alleviated by the incorporation of zonal calculation techniques, advanced gridding tools, and a chimera gridding method that allows arbitrary grid block overlap.

Validations of the calculation method were performed for a contra-rotating propeller, CR404 system, and a series 60, CB = 0.6, ship hull with a MAU propeller. Comparisons of the computational results to the measurement data are documented in this paper. Also, to demonstrate the predictive capability of the method, simulations were carried out for the series 60 ship hull with a single propeller and a contrarotating propeller under model and full scale conditions.
Flow Analysis, Design and Testing of Ducted Propellers
Authors: Zondervan Gert-Jan , Hoekstra Martin , Holtrop Jan
Published: January 2022

This paper addresses the design and the testing of ducted propellers and illustrates how flow analysis can be used as a support. After a review of the working principles of a ducted propeller system by referring to well-known theoretical analyses, it describes developments in computational methods. In particular, a numerical code simulating the viscous flow around a ducted propeller system in open water shows promising results. Since propellers in ducts are designed as quasi-open propellers, the estimation of the effective advance speed, influenced by the velocity field induced by the duct, is an important aspect. New estimates for dividing the induced flow field into a propeller and a duct contribution are given, which lead to better correspondence with experimental information. Polynomials describing the performance of the B-4-70 propeller in nozzle 19A are also provided, in addition to an empirical relation for the virtual pitch of the Ka-series propellers. Model testing of ducted propellers is evaluated against numerical simulation tools. It is concluded that, in spite of rapid developments in computational fluid dynamics, the propulsive performance of ducted propellers can still most accurately be assessed by model tests.
Design, Fabrication and Testing of the Composite Pitch-Adapting (Flex) Propellers
Authors: Chen Benjamin Y.H. , Neely Stephen K. , Michael Thad J. , Gowing Scott , Szwerc Richard P. , Buchler Dirk , Schult Reinert
Published: January 2022

Pitch adapting (Flexible) composite propellers offer the potential for improved performance over metal propellers in cavitation and vibration performance while reducing weight and manufacturing cost. As the propeller rotates in the non-uniform (circumferentially-varying) flow field, the blade deforms in response to the hydrodynamic loading, resulting in reduced cavitation and hull vibration. Using high-performance carbon fiber reinforced plastic (CFRP) as a blade material not only reduces the propeller weight but also increases the strength. The design and the analysis of two sets of rigid and flexible composite propellers are addressed. The fabrication was performed by A.I.R. using CFRP. The tests were carried out at the NSWCCD 36-in water tunnel. The test results show that the powering and cavitation performance of flexible propellers can be better than those of rigid propellers.
PTFE Faced Bearings for Marine Applications
Authors: Knox Robert T. , Simmons John E.L.
Published: January 2022

PTFE faced bearing technology, already established for hydro generator use, has been further developed for civil and military marine applications. The paper describes this type of bearing and the advantages compared with conventional babbitt. Details of testing and a description of a PTFE-faced thrust bearing supplied for the Japanese Techno Super Liner project are also presented.
Conversion of a Whitemetal/Oil System to Water Lubricated Bearings
Authors: Shaw John
Published: January 2022

Over fifty years ago, ship owners moved from open water lubricated stern tube bearings to oil-lubricated white metal bearings. Improvements in sealing technology encouraged this move. White metal bearings in a closed oil system offered a proven technology, which provided for predictable and controlled wear life and reduced

Recently, improvements in materials and bearing design have resulted in greater options in water-lubricated stern tube bearings that provide improved wear life. To eliminate any source of stern tube oil pollution and reduce risks associated with seal damage, some owners have made the decision to convert existing ships with oil-lubricated stern tubes to water-lubricated stern tubes.

This paper outlines the process used in converting a stern tube operating on oil-lubricated bearings to water-lubricated bearings through the experience of a recent conversion completed in China.
Teatro e ecologia: mudança de escalas ou de paradigma?
Authors: Sermon Julie
Published: January 2022

O artigo expõe os conceitos de antropoceno e ecologia na relação com a arte teatral, para problematizar possibilidades que artistas têm de produzir ideias e valores em consonância com a urgência ecológica nas relações individuais e coletivas entre os seres humanos e a natureza. Por meio de três caminhos, como meios de constituir as relações cênicas no teatro, a autora questiona sobre as ações humanas, seus limites e alcances na relação com as transformações globais planetárias, possíveis de serem representadas e sensibilizadas em cena, desde o tema, o projeto cenográfico e espacial ao projeto estético.
Teatro de animação, cultura popular e cosmovisão ecológica
Authors: Souza Andreia de Oliveira
Published: January 2022

O presente artigo relata parte de alguns processos artísticos que a autora desenvolveu com a Cia. Teatro da Recusa de 2017 a 2021 nos quais a temática sustentabilidade foi pensada sob a perspectiva da cosmovisão ecológica com enfoque na valorização da cultura popular brasileira. Esses processos que partiram da observação e pesquisa etnográfica resultaram na montagem de cinco trabalhos nas mais diversas técnicas do teatro de animação; manipulação de luva, vara (mamulengos), boneco gigante, híbridos, manipulação direta e de balcão, repertório este que servirá para propor reflexões sobre teatro de animação diversidade cultural, vivências e convivências.
Immunotherapy Approaches in T-Cell Lymphoma: Highlights From SOHO 2021
Authors: Valla, PharmD, BCOP Kelly
Published: January 2022

At the 2021 SOHO Annual Meeting, Maksim Mamonkin, PhD, of Baylor College of Medicine, reviewed progress in immunotherapy for T-cell lymphoma. Kelly Valla, PharmD, BCOP, of Winship Cancer Institute of Emory University, discusses key insights from this session for advanced practitioners.
Shared Decision-Making in Managing Breakthrough Cancer Pain in Patients With Advanced Cancer
Authors: Brant, PhD, APRN, AOCN, FAAN Jeannine , Wujcik, PhD, RN, FAAN Debra , N. Dudley, PhD William , Petok, MSW, LSW Alison , Worster, MD Brooke , Jones, MSN, NP Diane , Bosket, RN, BSN, OCN Kim , Brady, MSN, AGNP, APRN Christian , Tompkins Stricker, PhD, RN, ANP-BC Carrie
Published: January 2022

Background: Pain is a significant problem in patients with cancer. Breakthrough cancer pain contributes to the pain experience, but it is often underassessed and underrecognized. Shared decision-making (SDM), where patient preferences, goals, and concerns are discussed and integrated into a shared decision, can potentially foster earlier identification of pain, including breakthrough cancer pain, and improve pain management. Objectives: To explore the use of SDM to evaluate its impact on cancer pain management. Methods: This prospective, multisite study engaged patients with advanced cancer to explore the use of SDM in managing cancer pain using a digital platform with an expanded pain assessment. Decision preferences were noted and incorporated into care. Outcomes included pain and patient-perceived pain care quality. Results: 51 patients with advanced cancer enrolled in the study. The mean pain score was 5 out of 10 throughout the three study time points. 88% of patients experienced breakthrough cancer pain of severe intensity at baseline and approximately 70% at visits two and three. The majority of breakthrough cancer pain episodes lasted longer than 30 minutes. The majority (86%) of participating patients desired shared decision-making or patient-driven decision-making. Most patients expressed satisfaction with the level of shared decision-making in managing their cancer pain. Breakthrough cancer pain remained significant for most patients. Conclusions: SDM incorporated into pain discussions has the potential to improve pain outcomes, but significant challenges remain in managing breakthrough cancer pain.
Emerging Treatment Options for Advanced or Recurrent Endometrial Cancer
Authors: Halla, FNP-C Kimberly
Published: January 2022

Endometrial cancer is the most common cancer of the female reproductive organs. The American Cancer Society estimates that there will be over 65,950 new cases diagnosed in 2022. According to the National Comprehensive Cancer Network (NCCN) Guidelines, response rates in the front-line setting are approximately 40% to 62%. Prior to the recent U.S. Food and Drug Administration (FDA) approvals of immunotherapy, there had been no standard of care for women after failing front-line carboplatin and paclitaxel. In May 2017, the FDA approved single-agent pembrolizumab in microsatellite instability high (MSI-H)/mismatch repair deficient (dMMR) endometrial cancer patients following failure of systemic therapy. Then, in September 2019, the FDA approved pembrolizumab and lenvatinib for women who are not MSI-H or are MMR-proficient. This approval was based on KEYNOTE-146 and Study 111. Among 94 non–MSI-H women, 80% of those treated with pembrolizumab and lenvatinib had tumor shrinkage, and 38.3% had objective response by RECIST 1.1 as assessed by an independent radiology committee. The median duration of response was not reached, with 69% being progression free at 6 months. Grade 3/4 treatment-related adverse events (AEs) occurring in > 20%, including fatigue, hypertension, and gastrointestinal AEs. With supportive care, early identification, and intervention, the side effect profile was manageable, with only 21% discontinuing treatment due to AEs.
Antibiotic Therapy and Gastrointestinal Graft-Versus-Host Disease in the Allogeneic Stem Cell Transplantation Population
Authors: Thomas, MSN, APRN, FNP-C, AOCNP Jessica , Bowe, MSN, APRN, ANP-C Christi , E. Dains, DrPH, JD, APRN, FNP-BC, FNAP, FAANP Joyce
Published: January 2022

Purpose: Hematopoietic stem cell transplantation patients undergo rigorous courses of myeloablative chemotherapy that increase vulnerability for infections. Complications can arise in the form of graft-vs.-host disease (GvHD) manifesting in various organs, including the skin, lung, liver, and gastrointestinal (GI) tract. Antibiotic therapy is generally begun in order to prevent further complications from infection but may increase the risk for acute GI GvHD. Studies that investigated antibiotic therapy and the subsequent occurrence of GI GvHD in allogeneic stem cell transplantation (aSCT) patients were reviewed. Methods: PubMed, Scopus, and CINAHL databases were utilized. Articles published between January 1, 2009, and December 15, 2019, were included in this review. A total of 1,142 articles were retrieved. Duplicates, reviews, letters to the editors, irrelevant interventions/outcomes, and non-English articles were excluded. Inclusion criteria included individuals who were undergoing an aSCT and received antibiotic therapy. A total of seven articles were included for this review after applying the inclusion and exclusion criteria. Results: The use of broad-spectrum antibiotics increased the risk of developing GI GvHD. Stool analysis when available showed a decrease in the diversity of the gut microbiome, which in turn led to the increase in acute GvHD. Implications: The increased risk of GvHD may have implications for the standard of care therapy, which includes treatment, for infections during SCTs. Providers will need to weigh the risk vs. benefit of antibiotic therapy and exercise judicious selection of antibiotics prior to engraftment.
The Advanced Practitioner’s Role in Treating Patients With Hematologic Malignancies: Highlights From SOHO 2021
Authors: C. Geppner, MLS, CTTS, PA-C Alexis
Published: January 2022

Welcome to highlights from the ninth annual meeting of the Society of Hematologic Oncology (SOHO), presented virtually September 8 to September 11, 2021. This supplement to JADPRO provides an overview of selected lectures from the SOHO conference with the aim of educating advanced practitioners on cutting-edge advances, clinical applications, and novel biological and therapeutic approaches for patients with hematologic malignancies. Our objective is to promote research, education, prevention, and optimal patient care. In this edition, we highlight notable presentations from the SOHO conference in leukemia, lymphoma, myeloma, and related hematologic malignancies.
Employees’ Attitude Toward Women Managers in the UAE: Role of Socio-Demographic Factors
Authors: Nayeem Mohammed Abdul
Published: January 2022

This study aims to understand and examine the relationship between socio-demographic factors and the attitudes toward women managers in the context of the United Arab Emirates (UAE). This research paper is an exploratory research and we have taken into consideration a basic framework to understand the relationship that exists among different factors responsible for different perceptions and attitudes toward women managers. The literature review has focused on the various overarching perspectives of women managers and the attitudes formed by different societal actors. The paper draws mainly from the Social Learning Theory of Albert Bandura (1977). A sample of 213 employees was drawn to understand the relationship. The respondents were administered the well-established (Women as Managers Survey) WAMS questionnaire to get responses on various dimensions. Multivariate Regression Analysis using SPSS 26.0 version was applied to analyze the data.

The findings of the study are parallel to previous works such that age, work experience, and educational level found support to the hypothesized relationship whereas gender and marital status did not. Limitations and future direction along with practical implications and recommendations are also given to draw suitable inferences.
L’entrée des jeunes actifs dans l’animation socioculturelle : évolutions du rapport au travail durant le processus de socialisation professionnelle
Authors: Virgos Julien
Published: January 2022

This article explores changes in the “relationship to work” (Paugam, 2000; Longo, 2011; Longo & Bourdon,
2016) among young entrants in the field of youth work across the stages of “professional socialization”
(Hughes, 1996; Author 1, 2020) associated with the first years of practice. It explores the experiences of
17 young youth workers, based on comprehensive interviews conducted during ethnographic fieldwork
carried out in nine youth services organizations based in the Toulouse region of France. A combination
of thematic analysis and temporal bracketing supports cross-case analysis of the collected professional
trajectory narratives, revealing a four-part typology of how young workers develop their relationship to
work. The article identifies the three main factors at play as employment and working conditions, access
to occupational training, and relationships with managers in the workplace.
Compositional and planning peculiarities of estates of the highest nobility located in the remote counties of St. Petersburg governorate
Authors: Shuvaeva Evgeniia Yurievna
Published: January 2022

The object of this research is the estates of the highest nobility formed in the XVIII – early XX centuries in remote counties of the St. Petersburg governorate (Luzhsky, Gdovsky, Yamburgsky, Novoladozhsky) and partly in the border territories of Vyborg and Novgorod governorates. The subject of this research is the compositional and planning peculiarities typical to estates of the highest nobility, substantiated by the initial variants of landscape-geographical placement. The article is aimed at determination of the patterns of formation of compositional and planning structures of estates of the highest nobility, depending on the conditions of their initial landscape-geographical location. Such dependence reveals the characteristic features of the unique type of estates that belonged to the higher echelons society. Estates of the highest nobility in the remote counties of the governorate have not been previously studied as a separate typological unit, neither the correlation of their compositional and planning solution with the initial landscape situation. The author describes the estates that typologically belong to the remote estates of the highest nobility and located on the banks of large and small rivers, lakes, alongshore the Gulf of Finland, as well as on terrain without natural water bodies. Analysis is conducted on the initial landscape situations of placement, compositional and planning components of the complexes, as well as common patterns. On the example of particular estates(Nadbelje, Khrevitsy, Rapti, Valgovitsy), the author reveals the compositional and planning structure along with general principles of their formation in each typological group.
The formation of basic approaches of anthropological theater and theatrical anthropology
Authors: Stepanova Polina Mikhailovna
Published: January 2022

This article reveals the basic techniques and approaches formed at the dawn of two important and relevant vector of interaction between theater and cultural anthropology in modern theater art, anthropological theater and theatrical anthropology. The goal of this research lies in the analysis of basic techniques and terms that emerged at the early stages of establishment of practical and theoretical approaches towards studying the ritual and theatrical forms. P. Brook's expeditions raised the question of the key elements of theatrical art. For achieving the result, the English the director and screenwriter used bodily techniques and work with space and objects existing in ritual forms. E.Barba, while working in Amazon jungle, resorted to the tactics of participant observer B. Malinowski. The technique of cultural exchange, which appeared in 1970s, is used by K. Kazimierzczuk and modern Polish anthropological theater. The methods of cultural anthropology underlies the formation and development of new ways of interaction and communication between the actors and audience. The experimental works of Peter Brook and Eugenio Barba of the 1970s are analyzed from the perspective of using the methods of cultural anthropology by stage directors. Anthropological theater and theatrical anthropology reveal to modern practitioners and theorists of theatrical art a wide variety of unique methods of work with corporeal nature of the actor, and become the foothold for the development of new relations between the actor-performer and viewer-copartner in performative practices and multicultural phenomena.
Methodological peculiarities of organizing work in the profession-oriented pedagogical class
Authors: Arslanova Minzilya Nazifovna , Dorofeev Andrei Viktorovich , Sultanova Lyaisan Firdavisovna , Sytina Nadezhda Stepanovna , Zheltova Olesya Vladimirovna
Published: January 2022

The subject of this research is the arrangement of educational process in in the profession-oriented pedagogical class. The goal lies in explication of methodological peculiarities of working with high school students for professional self-determination and formation of their readiness to study at the pedagogical university. Leaning on the principles of multidimensional and nonlinear arrangement of educational process, humanistic orientation, unity of collective and individual forms of organizing the activity, as well as focus on the development of socially successful personality, the author outlines the methodological peculiarities of arrangement of educational environment of high school students in the “School – University” system. The project paradigm is implemented from the perspective of personality-oriented and subject-activity approaches in the four main modules of variable part of the curriculum of the profession-oriented pedagogical class: 1) “In the world of pedagogical profession”; 2) “The learned person: practical psychology of cognition”; 3) “I find myself in pedagogical profession; 4) “Learn who you truly are”. Readiness of high school students for project activity implies the abilities to search for data and establish correlations, create a project, analyze the problem field of research, find alternative solutions, and assess the acquired results. Project and game methods meet the goals of professional self-determination of high school students. The article presents the experience of functioning of the profession-oriented pedagogical class as the joint project of the Department of Pedagogy and Psychology of Bashkir State Pedagogical University named after M. Akmulla and School No. 113 named after Hero of the Soviet Union Ivan Ignatievich Rybalko (Ufa). Methodological recommendations on organizing the educational process in the profession-oriented pedagogical class can be applied in the senior middle school.
Remote supervision of autonomous agricultural machines: Concepts and feasibility
Authors:   Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB, R3T 5V6 Canada, Edet Uduak , Mann Danny ,   Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB, R3T 5V6 Canada
Published: January 2022

The scientific literature provides a description of various models depicting autonomous agricultural machines working to complete typical field operations. Many of the models involve some form of automation interface that is used by the machine owner to supervise the operation of the machine from a remote location. The objective of this study was to interview experts in the design of autonomous agricultural machines (university researchers, entrepreneurs, and leaders in the agricultural machinery sector) to ascertain their opinions about future autonomous agricultural machines, particularly related to how such machines will be supervised by the machine’s owner. Of the four remote supervision concepts described by participants (within the field, close to the field, from the farm office, and outside the farm site), the close-to-the-field remote supervision concept was determined to be the most viable concept. Designers were divided on the idea of providing real-time live video on the automation interface, however, most of them believed that having live video would reassure the farmer that everything was going well. Desktop computer, tablet and phone were the main devices recommended as tools for remote supervision (i.e., the hardware on which to display the automation interface), with tablet perhaps being the preferred alternative.
Electromagnetic wave propagation characteristics of oblique incidence nonlinear ionospheric Langmuir disturbance
Authors: Yang Li-Xia , Liu Chao , Li Qing-Liang , Yan Yu-Bo ,   College of Electronic Information Engineering, Anhui University, Hefei 230031, China,   Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui University, Hefei 230031, China,   Key Laboratory of Radio Environmental Characteristics and Modeling Technology, China Institute of Radio Wave Propagation, Qingdao 266107, China
Published: January 2022

Based on the generalized Zakharov model, a numerical model of electromagnetic wave propagating in the ionosphere at different angles is established by combining the finite difference time domain (FDTD) method of obliquely incident plasma with the double hydrodynamics equation and through equivalently transforming the two-dimensional Maxwell equation into one-dimensional Maxwell equation and the plasma hydrodynamics equation. In this paper. the dominant equation of Z-wave in obliquely incident nonlinear ionospheric plasma having been analyzed and deduced, the FDTD algorithm suitable for calculating the propagation characteristics of ionospheric electromagnetic wave is deduced. The simulation results prove the accuracy and effectiveness of this method for the Langmuir disturbance caused by electromagnetic wave heating the ionosphere at a small inclination angle. The results show that under small angle incidence, the high-power high-frequency electromagnetic wave excites the Langmuir wave near the O-wave reflection point in the ionospheric plasma. At the same time, the wave particle interaction causes the O-wave to convert into Z-wave and propagate into the higher region of the ionosphere. In this work, the electromagnetic wave propagation characteristics are further studied based on ionospheric plasma, which is helpful in laying the foundation of numerical algorithm for comprehensively and in depth analyzing the influence of ionospheric Langmuir disturbance on ionospheric radio wave propagation characteristics.
Generation and control of structural color in asymmetric coaxial cavity
Authors: Qian Qi-Sheng , Liu Hui-Yan , Zha Yong-Peng , Ni Hai-Bin ,   School of Electronics and Information Engineering, Nanjing University of Information Engineering, Nanjing 210044, China,   Jiangsu Key Laboratory of Meteorological Observation and Information Processing, Nanjing 210044, China
Published: January 2022

Metal nanostructures have great potential for generating and regulating structural color. In this paper, an array structure based on silver nano asymmetric coaxial cavity is designed to study the influence of ring cavity on the generation and regulation of structural color. The ordered array of asymmetric coaxial cavity is simulated by the finite difference time domain method, and the influence of structural parameters on structural color is obtained. The results show that by adjusting the depth, opening size and thickness of coaxial cavity, the rich structural colors can be produced. The experimental results and the simulation results are basically consistent with each other. Compared with the coaxial cavity with symmetrical structure, the asymmetric metal nanostructure proposed in this work has good adjustability in color display, and has potential applications in color imaging, high-resolution imaging, anti-counterfeiting, and so on.
Flow feature extraction models based on deep learning
Authors: Zhan Qing-Liang , Ge Yao-Jun , Bai Chun-Jin ,   College of Transportation and Engineering, Dalian Maritime University, Dalian 116026, China,   State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China
Published: January 2022

Extraction and recognition of the features of flow field is an important research area of fluid mechanics. However, the wake flow field of object immersed in fluid is complicated in the case of medium- and high-Reynolds number, thus it is difficult to extract and recognize the key features by using traditional physical models and mathematical methods. The continuous development of deep learning theory provides us with a new method of recognizing the complex flow features. A new method of extracting the features of the flow time history is proposed based on deep learning in this work. The accuracy of four deep learning model for feature recognition is studied. The results show that the proposed model can identify different characteristics of the wake time history and object shapes accurately. Some conclusions can be obtained below (i) The model based on convolutional layers has higher accuracy and is suitable for analyzing the features of flow time history data. (ii) The residual convolutional network, with a deeper structure and more complex inter-layer structure, has highest accuracy for feature recognition. (iii) The proposed method can extract and recognize the flow features from the perspective of physical quantities time history, which is a high-accuracy method, and it is an important new way to study the features of flow physical quantities.
A phase-field model for in-situ reaction process of metal-matrix composite materials
Authors: Guo Can , Kang Chen-Rui , Gao Ying , Zhang Yi-Chi , Deng Ying-Yuan , Ma Chao , Xu Chun-Jie , Liang Shu-Hua ,   School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048, China,   Material Research Center, CITIC Dicastal Co., Ltd, Qinhuangdao 066000, China
Published: January 2022

The in-situ reaction is an important method of preparing metal matrix composites: it can produce more uniform distribution of the reinforcement particles and more excellent structure of the phase boundary between the particles and the matrix. Therefore, the kinetics of in-situ reaction process deserves to be further studied. However, as the in-situ reaction is a rapid random process under high-temperature condition, it is difficult to observe the reaction process of metal-matrix composite materials experimentally. In this work, we propose a new phase-field model to describe the in-situ reaction process, and investigate the nucleation kinetic processes of in-situ reaction under different physical conditions. We find that the nucleation rate increases with the augment of curvature radius and noise intensity, and the size distribution of the particles is more uniform under the conditions of a small curvature radius and strong noise. With the increase of the undercooling, the nucleation rate first increases and then decreases, which is consistent with the classical nucleation theory.
Monte Carlo simulation of bond percolation on square lattice with complex neighborhoods
Authors: Xun Zhi-Peng , Hao Da-Peng ,   School of Material Sciences and Physics, China University of Mining and Technology, Xuzhou 221116, China
Published: January 2022

Based on an effective single cluster growth algorithm, bond percolation on square lattice with the nearest neighbors, the next nearest neighbors, up to the 5th nearest neighbors are investigated by Monte Carlo simulations. The bond percolation thresholds for more than 20 lattices are deduced, and the correlations between percolation threshold \begin{document}$p_{\rm c}$\end{document} and lattice structures are discussed in depth. By introducing the index \begin{document}$\xi = \displaystyle\sum\nolimits_{i} z_{i} r_{i}^{2} / i$\end{document} to remove the degeneracy, it is found that the thresholds follow a power law \begin{document}$p_{\rm c} \propto \xi^{-\gamma}$\end{document}, with \begin{document}$\gamma \approx 1$\end{document}, where \begin{document}$z_{i}$\end{document} is the ith neighborhood coordination number, and \begin{document}$r_{i}$\end{document} is the distance between sites in the i-th coordination zone and the central site.
Two-proton emission from excited states of proton-rich nuclei
Authors: Xing Feng-Zhu , Cui Jian-Po , Wang Yan-Zhao , Gu Jian-Zhong ,   Department of Mathematics and Physics, Shijiazhuang Tiedao University, Shijiazhuang 050043, China,   Institute of Applied Physics, Shijiazhuang Tiedao University, Shijiazhuang 050043, China,   China Institute of Atomic Energy, Beijing 102413, China
Published: January 2022

The effective liquid drop model (ELDM) and the generalized liquid drop model (GLDM) are extended to the case of studying the two-proton (2p) radioactivity from the excited states of proton-rich nuclei. It is shown that the experimental 2p decay half-lives are reproduced well by the ELDM and the GLDM. Then, the 2p decay half-lives of excited states of some nuclei that are not yet available experimentally are predicted by the two models, which are useful for searching for the new 2p decay candidates in future. Meanwhile, the above predicted half-lives are analyzed and compared with those given by the unified fission model (UFM). Next, the influence of the uncertainties of the decay energy and the angular momentum on the half-lives are analyzed in the frame of the two models by taking the 2p radioactivity of the 21+ isomeric state of 94Ag for example. It is found that the half-lives go up with the increase of the angular momentum, following the law of the quadratic function. Furthermore, the strong dependence of the half-lives on the decay energy suggests that it is important and necessary to measure accurately the mass value of the parent nucleus and the daughter nucleus and the excitation energy. Finally, it is necessary to point out that the existence of the 2p radioactivity in the 21+ isomeric state of 94Ag remains to be a mystery. Moreover, although the 2p radioactivity is observed from the higher excited states of 17Ne and 18Ne, the relevant hypotheses have not yet been further tested experimentally. The construction of a new generation of radioactive ion beam facilities, such as the high intensity heavy-ion accelerator facility (HIAF), is expected to be used to uncover the nature of the 2p radioactivity in the 21+ isomeric state of 94Ag and further test the hypotheses of the 2p decay from the higher excited states of 17Ne and 18Ne. On the other hand, some microscopic models, such as the shell model, need to be further developed by including some necessary physical factors, such as the tensor force, three-body force and accurate pairing force, to describe the mechanism of the 2p emission of the excited states more reasonably. In summary, more nuclear structure information can be extracted by studying the 2p radioactivity of the excited states. It is worth studying further although it is rather difficult to observe.
Interference suppression method in optical feedback-cavity enhanced absorption spectroscopy technology
Authors: Cheng Tong , Yang Tian-Yue , Gong Ting , Guo Gu-Qing , Qiu Xuan-Bing , Li Chuan-Liang , Zhao Gang , Ma Wei-Guang ,   Shanxi Engineering Research Center of Precision Measurement and Online Detection Equipment, School of Applied Science, Taiyuan University of Science and Technology, Taiyuan 030024, China,   State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China
Published: January 2022

In this paper, an efficient method of suppressing interference is presented in an optical feedback-cavity enhanced absorption spectroscopy (OF-CEAS) system. The Ariy function is used to analyze the interference signal in the transmission cavity mode signal. It is found that the interference signal in system originates from multiple reflections of the beam in the mirror, which is verified by replacing three kinds of cavity front mirrors with different thickness values. The result obtained by the Ariy function is used as a background signal, and the absorption spectrum signal can be obtained by making its difference from the absorption signal of the measured gas. This method effectively avoids the frequency error caused by the inability to measure the background signal and the absorption signal at the same time in the OF-CEAS system. Finally, the absorption characteristics of acetylene gas at 1.53 μm are measured. Based on the signal-to-noise ratio, the detection sensitivity of the system is evaluated to be 7.143 × 10–8 (1σ). Experiments show that this method is effective in improving the detection sensitivity of OF-CEAS system.
Strong coupling of single plasmonic nanoparticles and nanogaps with quantum emitters
Authors: Yan Xiao-Hong , Niu Yi-Jie , Xu Hong-Xing , Wei Hong ,   Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China,   School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China,   School of Physics and Technology, Wuhan University, Wuhan 430072, China,   Songshan Lake Materials Laboratory, Dongguan 523808, China
Published: January 2022

In cavity quantum electrodynamics, when the interaction between quantum emitter and cavity mode is strong enough to overcome the mean decay rate of the system, it will enter into a strong coupling regime, thereby forming part-light part-matter polariton states. Strong coupling can serve as a promising platform for room temperature Bose-Einstein condensation, polariton lasing, single photon nonlinearity, quantum information, etc. Localized surface plasmons supported by single metal nanostructures possess extremely small mode volume, which is favorable for realizing strong coupling. Moreover, the nanoscale dimensions of plasmonic structures can facilitate the miniaturization of strong coupling systems. Here, the research progress of strong plasmon-exciton coupling between single metal nanoparticles/nanogaps and quantum emitters is reviewed. The theory background of strong coupling is first introduced, including quantum treatment, classical coupled oscillator model, as well as the analytical expressions for scattering and photoluminescence spectra. Then, strong coupling between different kinds of plasmonic nanostructures and quantum emitters is reviewed. Single metal nanoparticles, nanoparticle dimers, and nanoparticle-on-mirror structures constitute the most typical plasmonic nanostructures. The nanogaps in the latter two systems can highly concentrate electromagnetic field, providing optical nanocavities with smaller mode volume than single nanoparticles. Therefore, the larger coupling strength can be achieved in the nanogap systems, which is conducive to strong coupling at the single-exciton level. In addition, the active tuning of strong coupling based separately on thermal, electrical and optical means are reviewed. The energy and oscillator strength of the excitons in transition metal dichalcogenide (TMDC) monolayers are dependent on temperature. Therefore, the strong coupling can be tuned by heating or cooling the system. The excitons in TMDC monolayers can also be tuned by electrical gating, enabling electrical control of strong coupling. Optically tuning the quantum emitters provides another way to actively control the strong coupling. Overall, the research on active tuning of strong plasmon-exciton coupling is still very limited, and more investigations are needed. Finally, this review is concluded with a short summary and the prospect of this field.
Non-dipole effects on angular distribution of photoelectrons in sequential two-photon double ionization of Ar atom and K+ ion
Authors: Ma Kun , Zhu Lin-Fan , Xie Lu-You ,   School of Information Engineering, Huangshan University, Huangshan 245041, China,   Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China,   College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070, China
Published: January 2022

Owing to the development of XUV and X ray of the free-electron lasers, the photoelectron angular distribution in the sequential two-photon double ionization has received increasing attention of theorists and experimentalists, because it provides the valuable information about the electronic structure of atom or molecule systems and allows the obtaining of additional information about mechanisms and pathways of the two-photon double ionization. In this paper, the expression of the sequential two-photon double ionization process of the photoelectron angular distributions, including the non-dipole effects, is obtained based on the multi-configuration Dirac-Fock method and the density matrix theory, and the corresponding calculation code is also developed. Based on the code, the sequential two-photon double ionization process of the 3p and 2p shells of Ar atom and K+ ion are studied, in which, the dipole and the non-dipole parameters of photoelectron angular distribution are investigated systematically. It is found that the angular distributions of the first- and second-step electrons in sequential two-photon double ionization are similar and the two photoionization processes affect each other. Near the ionization threshold, the photoionization cross-sections and anisotropy parameters for the 3p shell and the 2p shell show a large difference. While away from the threshold, the cross-section and angular anisotropy parameters of the 3p and 2p shells show similar behaviors. At the position of Cooper minimum of the photoionization cross section, the contribution of the electric dipole is suppressed, and the non-dipole effect is obvious. The non-dipole effect leads to a forward-backward asymmetric distribution of photoelectrons relative to the direction of incident light. The results of this paper will be helpful in studying the nonlinear processes of photon and matter interaction in the XUV range.
Back-projection method with fast time-delay correction for photoacoustic tomography reconstruction based on a focused sound field model
Authors: Luo Xiao-Fei , Wang Bo , Peng Kuan , Xiao Jia-Ying ,   Department of Biomedical Engineering, School of Basic Medical Science, Central South University, Changsha 410083, China
Published: January 2022

Photoacoustic tomography is a rapidly developing imaging technology, which can provide structural and functional information of biological tissues. It can integrate the advantage of high optical contrast from optical imaging with those from high penetration depth from ultrasound imaging. However, the existing back-projection algorithm in photoacoustic tomography equates the ultrasonic transducer scanning around the target to a point detector, which leads to a notable tangential blur in the eccentric imaging regions, and thus seriously degrading the image quality. In this paper, we propose a novel photoacoustic tomography reconstruction algorithm, which employs a focused sound field equivalent model to overcome the sound field distortion caused by the transducer’ finite aperture effect and can quickly and effectively restore the elongated tangential resolution in the eccentric imaging regions. Simulation results show that for the target with a diameter of 5 mm and a distance of 6 mm from the rotation center, the tangential resolution is improved by at least twice. Experimental results show that this method can effectively restore the image tangential blur in the off-center regions, where the tiny structures of complex targets can be detected. This new method provides a valuable alternative to the conventional back-projection method and plays an important guiding role in the design of photoacoustic tomography systems based on circle/sphere scanning.
Research progress on biological effects of cell membrane under infrared and terahertz irradiation
Authors: 薄文斐  , 车嵘  , 孔磊  , 张明洁  , 张晓波
Published: January 2022

Irradiation of terahertz electromagnetic wave including its short-wave band in infrared wave shows broad and important application prospects in biological science due to its noninvasive and nonionizing nature. Cell membrane is an important biological barrier for keeping cell integrity and homeostasis, and it is also the cellular structure that electromagnetic fields are firstly on in the case of terahertz irradiation. The responses of cell membrane to the electromagnetic fields are the mechanisms for most of the biological effects of terahertz irradiation. This paper at first expatiates the application safety of terahertz irradiation and its new application prospects in life medicine, neural regulation and artificial intelligence. Then, it systematically expatiates on the researches and developments in the biological effects of cell membrane under terahertz electromagnetic irradiation from the following four aspects: dielectric response characteristics of phospholipid membrane to terahertz electromagnetic irradiation, transmembrane transport of ions through membrane ion channel proteins under the irradiation, transmembrane transport of macromolecules and ions through phospholipid membrane under the irradiation, and the potential applications and role of biological effects of cell membrane under the irradiation. Meanwhile, the scientific discoveries that terahertz electromagnetic irradiation is able to activate voltage-gated calcium channels, voltage-gated potassium channels and active transport calcium channels in cell membrane and to create hydrophilic pores on the phospholipid membrane of cell membrane are introduced. At last, the summary and the directions of future efforts for the researches on the biological effects of cell membrane under terahertz irradiation are discussed.