bluuebunny/crossref_metadata_2025 huggingface dataset:
A quasi-D3-symmetrical metal chalcogenide cluster constructed by the corner-sharing of two T3 supertetrahedra
Authors: Sun Long , Zhang Hong-Yan , Zhang Jian , Jia Ying-Jie , Yu You-Zhu , Hou Juan-Juan , Wang Ying-Xia , Zhang Xian-Ming
Published: September 2020

The third type of a discrete cluster of metal chalcogenide was successfully prepared by selecting the organic base with strong alkaline and weak solvation. This work further enriches the structure chemistry of discrete supertetrahedral clusters.
Full-visible transmissive metagratings with large angle/wavelength/polarization tolerance
Authors: Deng Zi-Lan , Ye Xuan , Qiu Hao-Yang , Tu Qing-An , Shi Tan , Zhuang Ze-Peng , Cao Yaoyu , Guan Bai-Ou , Feng Naixing , Wang Guo Ping , Kapitanova Polina , Alù Andrea , Dong Jian-Wen , Li Xiangping
Published: September 2020

We introduce a transmissive perfect diffraction metagrating towards high-performance full-visible holograms with large angle/wavelength/polarization tolerance.
A one-step aqueous route to prepare polyacrylonitrile-based hydrogels with excellent ionic conductivity and extreme low temperature tolerance
Authors: Jiang Chi , Zhu Tang , Liu Huichao , Yang Guang , He Zhipeng , Wang Minjie , Ji Muwei , Cong Guangtao , Yu Jiali , Zhu Caizhen , Xu Jian
Published: September 2020

Polyacrylonitrile-based hydrogels with excellent ionic conductivity and anti-freezing properties were developedviaa one-step aqueous route and used as wearable sensors.
Preparation and multiferroicity of a novel two-dimensional material NiH2SeO4
Authors: Yu Bing , Shen Yang , Yang Shuai , Xu Dongdong , Lin Jianjun , Sun Lin , Tian Bobo , Zhu Qiuxiang , Duan Chungang , Zhao Qingbiao
Published: September 2020

We have prepared a new two-dimensional material and used first-principles calculations to predict its multiferroic properties.
Recent advances and perspectives on constructing metal oxide semiconductor gas sensing materials for efficient formaldehyde detection
Authors: Han Zejun , Qi Yuan , Yang Zhengyi , Han Hecheng , Jiang Yanyan , Du Wenjing , Zhang Xue , Zhang Jizhi , Dai Zhengfei , Wu Lili , Fletcher Cameron , Wang Zhou , Liu Jiurong , Lu Guixia , Wang Fenglong
Published: September 2020

The sensing mechanisms and effective strategies for enhancing the formaldehyde detection performance of metal oxide semiconductors have been reviewed.
The effects of driving time scales on heating in a coronal arcade
Authors: Howson T. A. , De Moortel I. , Fyfe L. E.
Published: September 2020

Context. The relative importance of alternating current (AC) and direct current (DC) heating mechanisms in maintaining the temperature of the solar corona is not well constrained.

Aims. We aim to investigate the effects of the characteristic time scales of photospheric driving on the injection and dissipation of magnetic and kinetic energy within a coronal arcade.

Methods. We conducted three-dimensional magnetohydrodynamic simulations of complex foot point driving imposed on a potential coronal arcade. We modified the typical time scales associated with the velocity driver to understand the efficiency of heating obtained using AC and DC drivers. We considered the implications for the injected Poynting flux and the spatial and temporal nature of the energy release in dissipative regimes.

Results. For the same driver amplitude and complexity, long time scale velocity motions are able to inject a much greater Poynting flux of energy into the corona. Consequently, in non-ideal regimes, slow stressing motions result in a greater increase in plasma temperature than for wave-like driving. In dissipative simulations, Ohmic heating is found to be much more significant than viscous heating. For all drivers in our parameter space, energy dissipation is greatest close to the base of the arcade, where the magnetic field strength is strongest, and at separatrix surfaces, where the field connectivity changes. Across all simulations, the background field is stressed with random foot point motions (in a manner more typical of DC heating studies), and, even for short time scale driving, the injected Poynting flux is large given the small amplitude flows considered. For long time scale driving, the rate of energy injection was comparable to the expected requirements in active regions. The heating rates were found to scale with the perturbed magnetic field strength and not the total field strength.

Conclusions. Alongside recent studies that show that power within the corona is dominated by low frequency motions, our results suggest that, in the closed corona, DC heating is more significant than AC heating.
Central discontinuous Galerkin methods on overlapping meshes for wave equations
Authors: Liu Yong , Lu Jianfang , Shu Chi-Wang , Zhang Mengping
Published: September 2020

In this paper, we study the central discontinuous Galerkin (DG) method on overlapping meshes for second order wave equations. We consider the first order hyperbolic system, which is equivalent to the second order scalar equation, and construct the corresponding central DG scheme. We then provide the stability analysis and the optimal error estimates for the proposed central DG scheme for one- and multi-dimensional cases with piecewise Pk elements. The optimal error estimates are valid for uniform Cartesian meshes and polynomials of arbitrary degree k ≥ 0. In particular, we adopt the techniques in Liu et al. (SIAM J. Numer. Anal. 56 (2018) 520–541; ESAIM: M2AN 54 (2020) 705–726) and obtain the local projection that is crucial in deriving the optimal order of convergence. The construction of the projection here is more challenging since the unknowns are highly coupled in the proposed scheme. Dispersion analysis is performed on the proposed scheme for one dimensional problems, indicating that the numerical solution with P1 elements reaches its minimum with a suitable parameter in the dissipation term. Several numerical examples including accuracy tests and long time simulation are presented to validate the theoretical results.
„Es tut mir leid“
Authors: Jutta von Campenhausen
Published: September 2020

Entschuldigungen haben in der Medizin einen schlechten Ruf. Dabei zeigen aufrichtige Worte des Bedauerns, dass der Arzt aufmerksam, empathisch und anspruchsvoll ist. Das verbessert nachweislich die Gesprächsatmosphäre. Haftungsrechtliche Folgen gibt es nicht.
Interventionelle Therapien zur Behandlung der hochgradigen Trikuspidalklappeninsuffizienz
Authors: Löw Kornelia , Hausleiter Jörg , Braun Daniel
Published: September 2020

Die Trikuspidalklappeninsuffizienz stellt eine häufige Manifestation valvulärer Herzerkrankungen dar, die sich in Abhängigkeit der Ätiologie in eine primäre und eine sekundäre Form unterteilen lässt und mit einer erhöhten Mortalität assoziiert ist. Aufgrund eines multimorbiden Patientenkollektivs und eines damit einhergehenden hohen operativen Risikos ist jedoch das in den Leitlinien empfohlene operative Vorgehen in vielen Fällen nicht umsetzbar. In den letzten Jahren wurden verschiedene interventionelle Therapieverfahren entwickelt, die 3 unterschiedliche Ansätze verfolgen: 1. Annuloplastiesysteme imitieren das chirurgische Verfahren der Ringannuloplastie mittels Raffung des Trikuspidalklappenannulus. 2. Koapationssysteme wie beispielsweise Edge-to-Edge-Verfahren bewirken eine Verringerung der Regurgitation durch Verkleinerung der Koaptationslücke auf Ebene der Klappensegel. 3. Heterotope Klappen fungieren als in die Vena cava inferior und superior eingesetzte Ventile und sollen den venösen Rückfluss in den Körperkreislauf reduzieren.
Kathetergestützte Aortenklappenimplantation
Authors: Seiffert Moritz , Ensminger Stephan
Published: September 2020

Die kathetergestützte Behandlung hat sich bei Patienten unterschiedlicher Risikoprofile mit hochgradiger symptomatischer Aortenklappenstenose als ein sehr sicheres Verfahren mit guten funktionellen Ergebnissen etabliert und ist für viele Patienten zur Behandlung der Wahl geworden. Insbesondere bei Patienten mit niedrigem operativem Risiko zeigten sich im kurzfristigen Verlauf einige Vorteile gegenüber dem operativen Aortenklappenersatz. Allerdings fielen in der mittelfristigen Nachbeobachtung kürzlich erstmals erhöhte Ereignisraten des kathetergestützten Verfahrens auf. Bei limitierten Daten zur Langzeit-Haltbarkeit der Transkatheter-Herzklappenprothesen steht insbesondere bei jüngeren Patienten die ausgewogene Diskussion der Therapieoptionen im interdisziplinären Heart Team mit dem Ziel eineslangfristigen Behandlungsplans im Vordergrund.
Kathetergestützter Mitralklappenersatz
Authors: Conradi Lenard , Lubos Edith
Published: September 2020

Die Behandlung der unterschiedlichen Formen der Mitralklappeninsuffizienz beruht gemäß aktuell geltender Leitlinien auf der Mitralklappenchirurgie, der kathetergestützten endovaskulären Edge-to-Edge-Therapie und einer medikamentösen, sowie in manchen Fällen der sekundären Mitralklappeninsuffizienz „device-basierten“ Herzinsuffizienztherapie. Derzeit gilt es, aus den bisherigen und zukünftigen Therapieoptionen ein maßgeschneidertes Konzept für die verschiedenen pathophysiologischen Varianten der Mitralklappeninsuffizienz zu etablieren. Neben diesen Konzepten haben in der jüngeren Vergangenheit Verfahren zum kathetergestützten Mitralklappenersatz („transcatheter mitral valve implantation“, TMVI) große Aufmerksamkeit erlangt. Diese Verfahren sind prinzipiell sowohl in chirurgisch-transapikaler als auch in endovaskulärer, transvenös-transseptaler Technik verfügbar.
Operative Mitralklappenrekonstruktion
Authors: Hamiko Marwan , Treede Hendrik , Reichenspurner Hermann
Published: September 2020

Die Mitralklappeninsuffizienz (MI) gehört neben der Aortenklappenstenose zu den häufigsten Klappenfehlern in den westlichen Ländern. Man unterscheidet je nach Pathologie zwischen der primären (degenerativen) und der sekundären (funktionellen) MI. Für die degenerative MI ist der therapeutische Goldstandard die chirurgisch-klappenerhaltende Korrektur des entsprechenden Klappenfehlers. Durch die Modernisierung der Herzchirurgie hat sich in den letzten Jahren zunehmend der Trend in Richtung minimal-invasiver Eingriffe gewandelt. Die in den letzten Jahren vorgestellten Methoden unterscheiden sich hauptsächlich im Zugangsweg. Der rechtsseitige anterolaterale Zugang ist aufgrund der guten Sicht auf die Mitralklappe inzwischen sowohl national als auch international als minimal-invasiver Zugang der Wahl etabliert. In wenigen spezialisierten Zentren wird darüber hinaus der videoassistierte total-endoskopische Zugangsweg mit exzellenten Ergebnissen angewendet.
Barriers to Implementing an Artificial Intelligence Model for Unplanned Readmissions
Authors: Baxter Sally L. , Bass Jeremy S. , Sitapati Amy M.
Published: September 2020

Background Electronic health record (EHR) vendors now offer “off-the-shelf” artificial intelligence (AI) models to client organizations. Our health system faced difficulties in promoting end-user utilization of a new AI model for predicting readmissions embedded in the EHR.

Objectives The aim is to conduct a case study centered on identifying barriers to uptake/utilization.

Methods A qualitative study was conducted using interviews with stakeholders. The interviews were used to identify relevant stakeholders, understand current workflows, identify implementation barriers, and formulate future strategies.

Results We discovered substantial variation in existing workflows around readmissions. Some stakeholders did not perform any formal readmissions risk assessment. Others accustomed to using existing risk scores such as LACE+ had concerns about transitioning to a new model. Some stakeholders had existing workflows in place that could accommodate the new model, but they were not previously aware that the new model was in production. Concerns expressed by end-users included: whether the model's predictors were relevant to their work, need for adoption of additional workflow processes, need for training and change management, and potential for unintended consequences (e.g., increased health care resource utilization due to potentially over-referring discharged patients to home health services).

Conclusion AI models for risk stratification, even if “off-the-shelf” by design, are unlikely to be “plug-and-play” in health care settings. Seeking out key stakeholders and defining clear use cases early in the implementation process can better facilitate utilization of these models.
Increased Incidence of Functional Constipation in Children with a History of Perianal Abscess—A Single-Center Retrospective Cohort Study
Authors: Deffaa Oliver Johannes , Gosemann Jan Hendrik , Lacher Martin , Wagner Richard
Published: September 2020

Introduction Functional constipation (FC) is a common gastrointestinal disorder affecting up to 30 % of children. Voluntary stool withholding (e.g., after painful defecation) with consecutive harder and larger stools can result in avoidance patterns. Perianal abscesses (PA) are associated with anal pain and painful stooling. We hypothesized that patients with PA have a higher incidence of subsequent FC compared with children without PA.

Materials and Methods Between January 2010 and December 2016, we retrospectively analyzed all infants (< 365 days of life) presenting at our institution with PA or unilateral inguinal hernia repair (IH; control group). We screened the clinical charts of these patients for outpatient or inpatient visits due to FC according to ROME IV criteria between 01/2010 and 10/2019. Statistical analysis was done using chi-squared test.

Results We included a total of 37 infants with PA and 118 with IH repair (controls). Mean age at presentation for PA was 3.7 ± 0.5 months compared with 4.2 ± 0.3 months at surgery for IH. In the PA group, 6/37 (16%) developed FC compared with 1/118 (1%) in the control group (p-value < 0.01). Patients with PA presented with FC at a mean age of 22.3 ± 4.6 months. Twenty-three of thirty-seven (62%) of PA patients underwent surgery. The development of FC in the PA group was independent of conservative versus surgical treatment (14 vs. 17%, p >0.05).

Conclusion Our study suggests that PA is associated with an increased risk of FC during the further course. Prophylactic stool softening in patients with PA may be considered to prevent subsequent FC.
Phenotypic Switch of Human Peritoneal Macrophages during Childhood
Authors: Schukfeh Nagoud , Elyas Amr , Viemann Dorothee , Ure Benno M. , Froemmel Stephanie , Park Joon-Keun , Kuebler Joachim F. , Vieten Gertrud
Published: September 2020

Introduction Human peritoneal macrophages are resident in the abdominal cavity where they support the specific microenvironmental regulation. We have previously observed a phenotypic switch of murine macrophages during infancy that was associated with a functional development. To investigate the age related changes in human peritoneal macrophages, we analyzed peritoneal macrophages of children undergoing laparoscopic procedures.

Materials and Methods Immunologically healthy children who received minimally invasive surgery in our department were included in this study. In all cases, the written consent was obtained. At the beginning of laparoscopy, physiologic NaCl-solution was instilled and manually removed through the umbilical trocar to gain macrophages. Lavage cells were processed for flow cytometry analysis. CD14+ myeloid cells were monitored for specific lineage marker expression.

Results A total of 21 donors (age: 7 days–18 years) were included and divided into three groups. In all age groups, 97% of myeloid cells expressed CD11b. 70% of these expressed CD14. Three subsets of CD14 cells were detected on the basis of CD14/CD16 expression (CD14 + CD16dim, CD14 + CD16inter, and CD14 + CD16high). In neonates, >80% belonged to the CD14 + CD16high subset, reducing to 30% in adolescents. In none of the cases, the M2 markers CD23 and CD25 were expressed.

Conclusion This is the first study showing that lineage marker expression of peritoneal macrophages in neonates differs from that in adults. The knowledge about neonatal tissue resident macrophages might help to understand their complex interaction and to use specific macrophage properties for therapeutic approaches.
Powering life through MitoTechnologies: exploring the bio-objectification of mitochondria in reproduction
Authors: Bühler Nolwenn , Herbrand Cathy
Published: September 2020

Mitochondria, the organelles providing the cell with energy, have recently gained greater public visibility in the UK and beyond, through the introduction of two reproductive technologies which involve their manipulation, specifically ‘mitochondrial donation’ to prevent the maternal transmission of inherited disorders, and ‘Augment’ to improve egg quality and fertility. Focusing on these two ‘MitoTechnologies’ and mobilising the conceptual framework of “bio-objectification”, we examine three key processes whereby mitochondria are made to appear to have a life of their own: their transferability, their optimisation of life processes and their capitalisation. We then explore the implications of their bio-objectification in the bioeconomy of reproduction. Drawing on publicly available material collected in two research projects, we argue that mitochondria become a biopolitical agent by contributing to the redefinition of life as something that can be boosted at the cellular level and in reproduction. Mitochondria are now presented as playing a key role for a successful and healthy conception through the development and promotion of MitoTechnologies. We also show how their “revitalising power” is invested with great promissory capital, mainly deriving from their ethical and scientific biovalue in the case of mitochondrial donation, and from the logics of assetisation, in the case of Augment.
Small transparent prism for the cross-sectional visualization for a turbulent scalar mixing layer using a water-channel PLIF method
Authors: Ukai Ryota , Suzuki Hiroki , Mochizuki Shisuke , Sakai Yasuhiko
Published: September 2020

This study introduces a simple method that enables cross-sectional visualization in the measurement of the planer-laser induced fluorescence (PLIF) method. The concentration field of the high Schmidt number scalar mixing layer generated by grid-generated turbulence is measured by a water-channel experiment in this tudy. The high Schmidt scalar mixing layer is produced by Rhodamine B aqueous solution and water. A small transparent prism, installed on the outside wall of the test section, aids in applying cross-sectional visualization. The small transparent prism is an isosceles triangular shaped prism filled with the working fluid through the test section of the water channel. The setting and details of the small transparent prism are shown in this study. By using the small transparent prism, the concentration field on the plane set into the test section is shown as a result of the cross-sectional visualization. In this result, a scalar structure like a mushroom is visualized around the mixing interface of the scalar mixing layer, as found in a previous experiment.
Design and implementation of multifunctional green induction lamp
Authors: Zhang Changyong , Yang Lixin , Tan Lang , Bai Zhihua , Liu Sheng
Published: September 2020

In order to meet the needs of society for energy-saving lamps, save energy and reduce costs, this paper designed a multi-function green sensor lamp. The system is based on microcomputer, using LED lighting technology, human body infrared sensing principle, photosensitive sensor principle and acoustic sensor principle to realize a new intelligent lighting tool for automatic control of light source lighting. The intelligent control of the illumination duration from both hardware and software enables the light control and voice-activated illumination functions, and has an anti-theft function, which can effectively improve home safety.
Two-way relaying channel with lattice forwarding and microwave power transfer
Authors: Wen Zhigang , Lv You , Li Shan , Liu Dan
Published: September 2020

In this paper, we consider a two-way relaying channel with simultaneous wireless information and power transfer. The intermediate relay station forwards lattice codes under transmit power constraint. Meanwhile, it charges user terminals for static circuit consumption and uplink transmission power. We novelly propose an iterative algorithm to maximize the sum-rate with joint beam-forming and power splitting design in MPT assisted TWRC. The method achieves the highest achievable rate compared with separate optimization designs and time switching method. Moreover, an extremely small gap between the proposed method and the outer cut-set bound is observed.
Design of tri-band chiral graphene based terahertz patch antenna
Authors: Hafdi Zakarya , Chaabi Abdelhafid , Tao Junwu
Published: September 2020

In this paper, a novel terahertz patch antenna is designed using a very thin layer of graphene as the radiating patch, to get tri-band operation. An attempt, is made to design both achiral and chiral graphene patch tri-band for 0.46/0.58/0.66-THz. The simulation has been carried out by using a full wave electromagnetic simulator based on FDTD method. We then expect these results to be of interest to scientists in the field of the interaction between the electromagnetic wave and grapheme to design potential application.
Transition model based design method investigation on laminar flow nacelle
Authors: Tao Yang , Xiong Neng , Huang Kang , Jun Lin , Wu Junqiang
Published: September 2020

Aerodynamic shape optimization of natural-laminar-flow (NLF) nacelle for lange-range wide-body transport aircraft was investigated. Perturbed class function/shape function transformation (CST) method was used to parameter the three typical generatrix of the nacelle combined with the perturbation based transfinite interpolation method to achieve surface and space grid update. The k-ω SST (shear stress transport) turbulence model and ϒ – Re
θ transition models was use to predict the transition location.The gradient based optimization method called Sequential Quadratic Programming was selected for the high efficiency. Natural laminar flow design was performed on three dimensional nacelles and about 45%∼55% laminar flow region was achieved by the optimization design.
Vehicle contact network based on fluid coupling analysis of load of operational status detection device
Authors: Tao Yang , Xiong Neng , Huang Kang , Wu Junqiang
Published: September 2020

Based on the analysis of aerodynamic load and structural strength of the vehicle contact network monitoring device, the distribution of aerodynamic moments and surface pressure of the monitoring device is calculated by means of fluid-solid coupling. The calculated load is applied to the surface of the device for structural analysis, mainly to investigate the maximum deformation and maximum equivalent stress of the device. The study found that air flow separation occurred above the ear region when driving forward, the pressure was higher, and the air flow below the ear region flowed around the ear region. The pressure difference between the upper and lower ears produced a downward force of about 150N in a single ear region, and produced a large rolling moment, after checking its connection strength with the central body to meet the requirements for use.
The generation of signal and background sky maps for ultra-high energy gamma ray source with a Monte Carlo method
Authors: Liu Jiali , He Guanda , Wang Hongyan
Published: September 2020

Studying the ultra-high energy gamma ray source is an important way to reveal the origin of the cosmic ray, which is also a main topic of many ground gamma ray experiments. To expect the observation ability during the design of the experiment, as well as to test the analyse methods in the observation, a Monte Carlo procedure for the signal and background generation is necessary. In this paper, such a procedure is introduced. And the source significance for a Blazar source Mrk421 is expected based on this procedure. Finally, an unfolding method for the source spectrum measurement is also established bashed on this Monte Carlo data, which gives fitting errors around ±10.0% both for the flux and the spectrum index.
Physical-chemical predictors of soil pollution in the megapolis
Authors: Azovtseva Natalya , Smagin Andrey , Sadovnokova Nadezhda , Kirichenko Anatoly , Lasareva Elena
Published: September 2020

The problem of quantitative assessment of soil pollution of the capital metropolis by controlling physical-chemical factors of solid and liquid phases of soil is investigated. The metals were used as an integral indicator of pollution taking into account the mass fraction and the variation of soil bulk density. Multiple regression (R2=0.91-0.95) of layered heavy metals, as well as accumulation of biophilic elements of the exchange fund from two main predictors – dispersion (effective specific surface area of solid phase, determined by the original thermal desorption method) and pH of salt extract was revealed.
A Bayesian estimation-based uncertainty quantification of flaws in steel welds detected by ultrasound phased array
Authors: He Jingran , Chen Zhijian , Luo Xuhui
Published: September 2020

Phased array ultrasonic scanning is currently the most advanced non-destructive test for detecting flaws in a steel welding. However, large uncertainty exists in the detection results. Technically, this uncertainty is induced by the sparsity of detection resolution compared to the scale of the flaws. Consequently, it is essential to enrich the resolution of detection results and quantify the corresponding statistical uncertainty before evaluating the number and equivalent of the flaws in the steel welding. In this paper an uncertainty quantification framework is built with Bayesian compressive sensing method from which the equivalent of the flaws in the steel welding with certain degree of confidence can finally be given.
Effects of chlorine atoms doping on the electronic structure of monolayer molybdenum disulfide
Authors: Wang Ruoxin
Published: September 2020

Two dimensional materials have special properties including small size effect, surface effect and quantum confinement effect caused by limited dimensionality, and their energy band can be tuned while doping by impurity elements. Recently, two dimensional transition metal dichalcogenides (TMDCs) are thought to be the most prospective material to fit Moore’s law. Among them, MoS2 is the most common and important materials in research and it might have the best photoelectric property among all known two dimensional materials. In this article, we simulated n-doped monolayer MoS2 with chlorine atoms with the method of density functional theory and studied the effect on its electronic structure like electronic density of states and energy band structures. The results showed that this chlorine doping can introduce a defect energy level in the band structure of the monolayer MoS2 and make it become n-type semiconductor. Our work lays a foundation for further research on the doping of other two-dimensional materials besides MoS2 together with the study on the materials’ electronic structure.
Cascading failure dynamic of cyber-physical power system considering malware attacks
Authors: Shen Meie , Gao Xingle , Peng Minfang
Published: September 2020

With the development of cyber-physical power system, cyber security has a serious impact on the operation of power system. In this paper, a stochastic cascading failure model considering the structural and dynamical characteristics of cyber-physical power system is proposed. The model takes into account the community structure of networks, the heterogeneity of network nodes and the complex interdependence of coupling networks. Moreover, the malware spreading in the cyber network and the power flow redistribution in the power grid are considered to describe the dynamic physical processes of the system, and a stochastic method is adopted to describe the operating state transition of network components. Simulation results indicate that the cascading failure of coupled system is the result of malware attacks repeatedly triggering the power grid, and cyber coupling will aggravate the severity of grid failure propagation.
Optimization method of acoustic measurement station placement for wide-area miss distance
Authors: Wang Yulong , Lu Xiaoxi , Liu Yanhong , Zhang Liang , Wei Chuangfei
Published: September 2020

This paper focuses on the issue of how to select the optimal deployment scheme for the dispersal of miss distance during acoustic rendezvous measurements. Firstly, the measurement theory of acoustic rendezvous is introduced, and then the error model of acoustic rendezvous measurement is deduced and theoretical analysis is carried out. Then, an error evaluation index is established based on the dispersion characteristics of miss distance. Finally, simulation experiments are conducted for the miss distance obeying uniform distribution and normal distribution. Simulation experiments verify the correctness of the method in this paper, which has important guiding significance for the miss distance test.
Flow field calibration of a newly developed Laval nozzle in 2.4m transonic wind tunnel
Authors: Liu Guangyuan , Chen Xuekong , Guo Qiuting , Shi Xiaojun
Published: September 2020

The range of Mach number of 1.3 to 1.5 is defined as low-supersonic flow in wind tunnel testing, which is necessary range for major fighters, aerospace vehicles, and missiles to reach the cruise state. It is also the most difficult test range for conventional ground simulation equipment due to sound barrier and uniformity of artificial air flows. In order to expand the test range of 2.4m transonic wind tunnel, researches on low supersonic flow filed calibration was carried out, and the geometrical parameters of perforated walls in test section were determined. Measured results of flow uniformity are compared with advanced wind tunnels using cross-shaped rake and cone-cylinder model. The results show that uniformed low supersonic flow in model testing area was obtained using newly developed nozzle together with perforated walls in 2.4m transonic wind tunnel, which effectively improve the simulation capability of the facility. Together with the capacity of 2m supersonic wind tunnel, seamless link of test data has been achieved in high speed regime, which has formed an integrated test platform for sub-, trans-, and supersonic speeds on the order of 2 meters.
Influence of the conical seamount on underwater sound propagation in a 3D shallow sea environment
Authors: Xiao Rui , Zhu Hanhao , Xue Yangyang , Jiang Hui , Chen Chao , Zhu Jun
Published: September 2020

The sound field of a 3D shallow sea environment with a conical submarine mountain is simulated and calculated using the finite element method. To verify the accuracy of the finite element calculation results, the effects of submarine mountain height and sound source depth on sound-propagation characteristics are evaluated. The simulation results indicate that owing to the reflection and concentration of acoustic energy due to the submarine mountain, before the sound wave reaches the subsea mountain, the impact of subsea mountain on the acoustic energy can reach 10 dB. In addition, the sound energy is hindered by the seamount. Therefore, the sound energy loss after the sound wave reaches the subsea mountain is higher than the sound energy loss in the absence of the seamount under the same circumstance, and the maximum is up to 20 dB. The larger the seamount height and sound source depth, the more significant the blocking and accumulation of the sound energy.
Reconstructing the multicellular structure of a developing metazoan embryo with repulsion-attraction model and cell-cell connection atlas in vivo
Authors: Guan Guoye , Tang Lei-Han , Tang Chao
Published: September 2020

Embryogenesis is a spatio-temporal multicellular evolutional process involved with intracellular biochemical activities and intercellular biophysical interactions. Reproducible and precise multicellular structures contribute to robustness of embryonic development by cell-cell communication, morphogenesis and other significant biological events. Using Caenorhabditis elegans as animal model, recently several researches established mechanical models to reconstruct the multicellular structures of this developmental system, in which cells interact via repulsive or attractive potentials inside an ellipsoidal eggshell. However, those models ignored some practical details and lack of test in depth. In this paper, we improved an in silico modeling framework based on previous models by revising formulae of interactive force and applying in vivo experimental information of eggshell shape, cell volume, cell position and cell-cell connection relationship. Cell pairs with and without empirically repeated connection were regarded to have different types of attractive force, which could help stabilize cells into their experimentally observed locations accompanied by correct neighbour relationships. Both previous models and our revised ones were tested, verified and compared to each other. Our modeling framework not only reproduces the multicellular structure patterns in an artificially compressed embryo with ∼50 cells, but also exhibits a potential to uncover active adjustments and controls on cell positioning.
Research on rapid planning of intelligent aircraft trajectory under multiple constraints
Authors: Li Fangfang , Li Zuozhi
Published: September 2020

Intelligent aircraft trajectory planning is an important support to ensure the successful completion of the mission of the aircraft, and it is also a key component of the intelligent aircraft mission planning system. Due to system performance constraints and environmental constraints, the positioning system of the intelligent aircraft cannot be accurately positioned during flight, which will cause flight errors. Excessive flight errors will lead to the failure of the mission. Therefore, error correction plays an increasingly important role in trajectory planning. This paper studies the rapid trajectory planning of intelligent aircraft under the limitation of system positioning accuracy. Based on the optimization theory, with the error generation rules and correction rules of the intelligent aircraft in flight as constraints, establishes the optimization model, and uses the fast non-dominated multi-objective optimization algorithm (NSGA-II) with elite retention strategy. This paper corrects the vertical and horizontal errors during the flight, and finally designs a reasonable intelligent aircraft trajectory that meets the minimum trajectory length and the minimum number of corrections during the flight.
Measurement of CO temperature and concentration in flat flame based on mid infrared wavelength modulation
Authors: Hu Shangwei , Tu Xiaobo , Li Meng , Chen Shuang , Yang Furong
Published: September 2020

CO in combustion products of aeroengine is a sign product of incomplete combustion. Real-time monitoring of CO can feedback combustion efficiency, which is of great significance to the design of combustion chamber and the optimization of fuel ratio of aeroengine. In this paper, based on the mid infrared absorption spectroscopy, a single optical path calibration-free wavelength modulation method is proposed to measure the temperature and concentration of CO in a flat flame. Firstly, the spectrum of light intensity signal and the amplitude frequency response of different frequencies are analysed, and the appropriate scanning frequency and modulation frequency are selected. Secondly, the equalization of Butterworth filter in DPLA is proposed to extract the first and second harmonics. The filter can effectively reduce the influence of nonlinear phase. Furthermore, calibration-free wavelength modulation method is simulated to measure CO at different temperature and concentration. Finally, CO in flat flame with different equivalence ratio at 5mm was measured for verification. The relative error between the measurement results of calibration-free wavelength modulation and that of thermocouple measurement is within 3.6% in the range of concentration 0.11% ∼ 0.24%, which verified the feasibility and effectiveness of the measurement scheme, and provided a reference for the CO concentration measurement at the outlet of aeroengine.
A proposal design for robust and broadband microwave SPPs waveguide coupler via STIRAP
Authors: Qu Xiaowei , Yin Shan , Zhang Wentao , Huang Wei
Published: September 2020

In this paper, we give a proposal to design a microwave Surface Plasmon Polaritons (SPPs) coupler, which can completely transfer energy of SPPs with robustness against varying geometrical parameters and broadband frequency range of microwave, based on Stimulated Raman Adiabatic Passage (STIRAP). The STIRAP is one of the most famous quantum coherent control methods, and most importantly it can improve the robustness of the device and energy transmission efficiency. This work is not only promising in designing robust and broadband compact microwave couplers, but also leading larger potential applications in microwave and millimeter wave communication.
Thermally controlled electromagnetically induced transparency in hybrid metal-InSb metamaterials at THz frequencies
Authors: Li Hongyang , Huang Wei , Zhang Wentao , Yin Shan
Published: September 2020

We demonstrate an active controlled electromagnetically induced transparency (EIT) device via thermal control in a hybrid metamaterial, which consists of two split-ring resonators (SRRs) with integrated InSb-metal and a cut wire (CW) in a unit cell. We can dynamically control the amplitude modulation of the EIT window, by varying the temperature of the InSb thereby changing the damping rate of the dark mode of SRRs. When the temperature of the InSb changes from 240K to 320K, the EIT window undergoes modulation from on to off, and the modulation depth reaches 86.8%. The results are not only promising in designing compact slow light devices in the terahertz regime but also leading some essential applications in terahertz communications.
A theoretical study of noxious gases storage using covalent organic frameworks (COFs)
Authors: Xia Liang , Yang Yingjian , Chan Yue
Published: September 2020

Using covalent organic frameworks (COFs) to capture noxious gas has become an increasing research interest, especially for the purpose of environmental protection. A theoretical study on the interactions of carbon monoxide (CO), sulfur dioxide (SO2) and nitric oxide (NO), respectively with COF-300 has been proposed, based on the theory of the continuum approximation using Lennard-Jones potential. We discover that COF-300 can store more SO2 in comparison to CO and NO under an increasing pressure at 77K. The present methodology is computationally efficient and can be employed in other types of gases and nano-porous materials without conceptual difficulties.
Research on coupling property of side-coupled asymmetric square-ring resonator in a plasmonic waveguide
Authors: Guo Ling , Guo Mengran , Yin Shan , Chen Shouhong , Ma Jun
Published: September 2020

The characteristics of resonant modes in the side-coupled asymmetric square-ring resonator based on a plasmonic waveguide are investigated. The 1-order modes and 2-order modes can be manipulated by adjusting the longitudinal distance Δz and transversal distance Δx of the metal block in the square air cavity. The coupling and splitting effect of the resonant modes in the asymmetric square ring resonator are exploring. The proposed structure is potential in sensing and filtering.
Three different approaches to analysis cracked ring with opposite concentrated loads
Authors: Young Lih-jier , Chen Ming-Li
Published: September 2020

Circular ring is the most useful specimen in industry. However, any small crack exists on it will cause some damage about the equipment and even more some serious disaster. As we understand plastic hinge will appear if we increase the load of the ring. The ring will collapse when there are four plastic hinges. The sequence of formation of these hinges is also depended on the location of the crack of the ring. In this paper three different approaches i.e., theoretical, numerical, and experimental will be presented. The theoretical approach is based on the linear elastic fracture mechanics (LEFM) and the method of superposition. The boundary element method (BEM) will be employed in the numerical approach. Finally, the cracked ring specimen was made of Aluminum 6061-T6 whose property is close to the ideally elastic-plastic material property in the experimental approach. The results show the consistency of these three different approaches and provide reasonable information to inspect the circular ring used in daily life.
The signed (| G |−1)-subdomination number of lollipop graphs
Authors: Shi Wei , Wu Suichao
Published: September 2020

Let G be a lollipop graph obtained by appending a cycle Cn
to a pendent vertex of a path Pm
. In this paper, the signed (| G |−1) - subdomination number of a lollipop graph G is determined by classified discussion and exhaustived method.
Prediction of the crowd behavior in campus based on time series model
Authors: Chen Liangwei , Yang Jingjing , Chen Zhigang , Huang Ming
Published: September 2020

Recognizing and understanding the behavior of the campus crowd is of great significance for improving the comprehensive management capabilities of the campus. The increasingly abundant of mobile terminal WIFI signals provide a unique data source for studying the behavior of the campus crowd. A Wifi-based personnel activity monitoring system is developed in this paper. Through monitoring and analyzing the MAC address (Media Access Control Address), RSSI (Received Signal Strength Indication) and Wireless AP (Access Point) in and around the Science Museum, Huaizhou building of Yunnan University, the association between WIFI signal and the crowd behavior is studied. Time series analysis is used to make predictions, and some valuable information about the gathering and activity status of campus crowd behavior is obtained. It provides an experimental platform for studying the dynamic behavior of people in campus or other crowd areas.
Study on nonlinear analysis of MEG in patients with brain diseases
Authors: Zhang Yiling , Zhang Yu , Chen Junwei , Yan Wei , Yuan Zizhen , Wang Jun
Published: September 2020

Magnetoencephalography (MEG) is a kind of brain function detection technology without trauma, which detects the electromagnetic physiological signal in the brain. It is widely used in depression research. We used permutation entropy, improved permutation entropy, conditional entropy to study the difference of MEG between depressed patients and healthy people, respectively. We implement three different entropy algorithms and compare the relative differences of entropy values in different brain regions of healthy people and depression patients under positive, neutral and negative emotional stimuli. The experimental results show that the relative difference of conditional entropy > the relative difference of improved permutation entropy > the relative difference of permutation entropy, and the difference of entropy value in the frontal region of human brain is the most obvious, which may provide the basis for the diagnosis of depression.
An efficient method to reduce ill-posedness for dynamic load identification in short duration wind tunnels
Authors: Wu Long , Wang Feng , Ding Zhijian , Du Yufeng , Chen Shengbing
Published: September 2020

For the inverse problem of dynamic load identification in short duration wind tunnels, high system ill-posedness is a main cause leading to instability and low accuracy. In this study, an efficient method is proposed to reduce ill-posedness and identify dynamic load stably. The load to be identified is written as superposition of specific basis functions and each basis function is determined by specific parameters. A genetic algorithm is built to solve the parameters and construct the load. Compared with Tikhonov regularization method, the basis function method proposed can reduce the ill-posedness and numerical studies demonstrate its efficiency and accuracy.
Identification of adulterated olive oil by fusion of near infrared and Raman spectroscopy
Authors: Xu Qiang , Yang Xingxing , Hu Zhui , Li Yuan , Zheng Xiao
Published: September 2020

Aiming at the identification of adulterated olive oil, based on the fusion of near-infrared and Raman data on the feature level, a model for the identification of adulterated olive oil was established.24 pure olive oil samples and 248 adulterated olive oil samples were used for model establishment in the experiment. With three parameter optimization methods, support vector machine classification and regression models were established based on fusion of near-infrared and Raman data on the feature level with canonical correlation analysis (CCA). The results showed that the accuracy of correction and prediction sets of olive oil adulteration classification model based on the fusion of near-infrared and Raman data was high, and the correlation coefficient of prediction model based on the fusion of near-infrared and Raman data reached 99.13%. The results showed that the classification and prediction models were feasible and effective in the identification of adulterated olive oils, and this work shed light on the development and applications of fusion of spectral data.
Analysis of main control factors of CBM productivity and optimization of sweet spot area in S block of Surat basin
Authors: Cui Zehong , Liu Lingli , Wang Jianjun , Xia Zhaohui
Published: September 2020

S block is located in the eastern margin of Surat basin, with large area and great difference in geological conditions. How to optimize the sweet spot development zone is the key to achieve the economic and efficient development of the block. Based on the static and dynamic data, this paper conducts the sensitivity analysis for peak gas rate of well, Estimated ultimate recovery(EUR) of well and coal reservoir geological parameters. On the precondition of coal seam permeability higher than 100md, the coal seam thickness and gas content are the main factors affecting the development effect. According to the differences of key reservoir parameters, four types of reservoirs are divided: type 1 reservoir thickness≥20m, dry-ash-free gas content≥4m3/t; type 2 reservoir Thickness ≥20m, dry-ash-free gas content between 3.6-4m3/t; type 3 reservoir thickness between 10-20m, dry-ash-free gas content between 3.2-3.6m3/t; type 4 reservoir thickness between 10-20m, dry-ash-free gas content between 2.8-3.2m3/t. Considering the reserve abundance and exploitable value, reservoirs of type 1 and 2 are considered as the development sweet spot area, which provides guidance for optimum selection of development area of coalbed methane(CBM) in S block of Surat basin.
An efficient ADMM-type algorithm for deep semi-nonnegative matrix factorization
Authors: Zhou Yijia , Xu Lijun
Published: September 2020

In this paper, we focus on deep semi-nonnegative matrix factorization (DSemiNMF) which has a wider application in the real world than traditional NMF. We propose an efficient algorithm based on the classic alternating direction method of multipliers (ADMM) for DSemiNMF. By utilizing structures in DSemiNMF, we derive an efficient updating rule for updating subproblems according to its KKT conditions. Numerical experiments are conducted to compare the proposed algorithm with state-of-the-art deep semi-NMF algorithm. Results show that our algorithm performs better and the deep model indeed results in better clustering accuracy than single-layer model.