bluuebunny/crossref_metadata_2025 huggingface dataset:
A Probe into Cultivation Path of Students’ Ability in Innovative Digital Technology Design Based on Design Thinking
Authors: Meina Wang , Fan Wu , Kaining Meng , Yang Luo
Published: February 2021

Having risen to the height of the future development of the country, the cultivation of innovative digital technology design talents has become the general trend of the development of the education industry of the world. How to cultivate students’ innovative ability is a huge challenge for the current education circle. Design thinking is a creative problem-solving thinking model and methodology separated from design. The Paper started with the essence of design thinking. The application and practice of all institutions on the innovation process of design thinking were analyzed, and its modes and ideas in the fields of industry, commerce, and design were combined. The innovative curriculum design was carried out based on the five foundations of the design thinking model of Stanford University, and the operability of teaching links, the iterative cycle of the process, and the effectiveness of students’ hands-on actions were emphasized. In the Paper, effective operation guidance for the cultivation of students’ innovation ability was provided. Besides, a cyclic and iterative co-creation ecosystem in colleges and universities can be built to link the integration of industry and education with digital technology design innovation. In the Paper, the “three innovations” (creativity, innovation, entrepreneurship) were focused to explore a new path to cultivate students’ ability in innovative digital technology design, which is of great significance to the cultivation of innovative talents in digital technology design, the reform of teaching forms, and teaching contents.
Digital experience design of qinhuai lantern based on user journey map
Authors: nannan Li , zhangping Lu , mingzhu Li , ying Ding
Published: February 2021

This research extends the design concepts and research methods of user journey maps to the field of intangible cultural heritage, and selects the typical lotus lantern material package in Qinhuai lanterns as an example to explore the digital experience design of lanterns. On-site research methods are used to understand users, define target users and build personas. AEIOU recording framework is used to record user behavior, analyze and reorganize user behavior with card classification, and summarize user behavior flow. The Likert Smiley Scale is used to ask children to evaluate specific behaviors, get emotional curves, and summarize design opportunities from the perspective of valley filling. Given the pain points in the experience of the target user children and the indirect user parents, the lotus lantern material package is digitally redesigned from four perspectives of materials, connection methods between materials, functions and storage to meet the users' emotional experience. This research method and process have certain reference significance for experience design research on the same type of intangible cultural heritages.
Distribution of Triarrhena lutarioriparia and its reserve characteristics of nitrogen and phosphorus in Dongting Lake
Authors: Xu Youze , Fu Guangyi , Tang Nan , He Zhonghao , Jian Lincheng , Zhao Yuanyuan
Published: February 2021

Triarrhena lutarioriparia, a typical and most abundant macrophyte in Dongting lake wetland, was in the state of abandonment following the papermaking industry revocation in the lake basin. In order to provide scientific basis for precise management of T. lutarioriparia, the T. lutarioriparia distribution charateristics in Dongting Lake and its storage characteristics of nutrients were investigated in this study. Remote sensing interpretation results showed that the total area of T. lutarioriparia in Dongting Lake wetland was 58, 450 ha, 48.31% of which distributed in South Doting Lake wetlands. The nutrients contents were significantly different in T. lutarioriparia tissues, ranking in the descending order of spikes (TN 27.90 mg/g, TP 3.46 mg/g)>leaves (TN 16.38 mg/g, TP 2.11 mg/g)>stems (TN 5.38 mg/g, TP 0.85 mg/g). The total P quantities in each T. lutarioriparia tissue were ranked in the order: stems (560.26 t)>leaves (396.52 t)>spikes (284.67 t), while the total N quantities were within the range of 2170.02-2801.3 t. It was estimated that about 7712.99 t of TN and 1241.45 t of TP were annually removed from Dongting Lake by reaping T. lutarioriparia. The nutrients stored in the dead tissues of T. lutarioriparia might possess non-negligible impact on the water quality of Doting Lake.
Research on InSAR Monitoring Precision Analysis of Coal Mining Influence Based on Long Time Sequence
Authors: Gao Junhai , Gao Rongjiu , Chen Lisheng , Han Yongbin , Yan Jiancheng , Li Xingli
Published: February 2021

In this paper, in view of the scope of coal mining subsidence, the magnitude of subsidence deformation and the impact on buildings (structures), InSAR technology is selected for monitoring, time series analysis method combined with D-InSAR method for processing, and Sentinel- 1 Satellite IW data and RADARSAT-2 satellite XF data have been monitored for four years in the mining-affected area and its surrounding areas. The results show that there are obvious subsidence ranges on the surface of the current mining area and the unstable settlement area. The Shen District has been in a stable state in recent years, and the time sequence analysis for more than 3 years has verified the high accuracy and reliability of the monitoring results. The analysis of the monitoring results shows that the InSAR technology can be used for mining subsidence monitoring, especially when determining the subsidence boundary and whether it is stable or not, it has its technical superiority.
Spatio-temporal variation analysis of snow cover in China-Pakistan Economic Corridor based on remote sensing technology
Authors: Zhang Fan , Zhang ZhiHua
Published: February 2021

Based on the MODIS10A2 snow product data from 2001 to 2019, the characteristics of annual variation, interannual variation and spatial distribution of snow cover in China Pakistan Economic Corridor from 2001 to 2019 are analyzed by using remote sensing technology. The result shows that: the snow-cover in a year generally starts from the middle of October, and the snow cover area reaches the maximum value in January of the next year, and reaches the minimum value in July. From 2001 to 2019, the snow area of China-Pakistan Economic Corridor generally showed a decreasing trend. The distribution of snow in the China-Pakistan Economic Corridor is extremely uneven. The northern area is obviously more than that in the south. The mountainous and plateau areas are with high frequency of snow cover, and the plains are areas with low frequency of snow-cover. Permanent snow-cover is relatively low. Few, mainly concentrated in the Karakoram Mountains, in terms of distribution range, mainly distributed in 4452-8378 m.
Review on remediation of contaminated groundwater by Fe0-PRB technology
Authors: Zhang Xiaohui , Wang Xiaodong , Sun Xianfeng
Published: February 2021

PRB technology is a new groundwater remediation technology, which is currently in the pilot test stage in China. Zero-valent iron is one of the most commonly used fillers in permeable reaction walls. In this paper, the principle and structure of PRB technology, the working principle of zero-valent iron in PRB, the preparation method and the optimization and improvement of application technology, the application examples at home and abroad and the prospect of PRB technology are introduced.
Research on the Impact Test and Control Countermeasures of Residential Elevator Operation Noise
Authors: Peng Hong , Lv Zhong , Chen Mingfeng
Published: February 2021

The influence of the residential elevator operating noise on the indoor personnel of the adjacent elevator room is becoming more and more prominent. Through on-site testing of a household in Chongqing affected by elevator noise, the noise distribution in key areas affected by elevator noise was experimentally studied, and compared with the current standard limits. Combined with the noise spectrum characteristics, the experimental analysis obtained the noise spectrum diagrams of different areas such as elevator machine rooms, corridors and bedrooms. It is believed that low-frequency noise has a greater impact on the residential acoustic environment. Combined with the noise propagation path of elevators, the technical measures and improvement schemes for noise reduction of elevator equipment operation noise are proposed, which can provide reference for the design and improvement of residential acoustic environment.
Study on the Design of Avocado-fiber Skincare Knitted Underwear
Authors: Wang Shi , Li Junjia , Zhao Fu
Published: February 2021

With the continuous changes taken place in people’s lifestyles, functional underwear has drawn attention from more consumer groups. Skincare, comfortable knitted underwear fabrics can be made by adding refined avocado oil into viscose to yield fibers and then blending it with other fibers such as acrylic and wormwood fiber. This article first introduces the moisture-retaining principles, raw material selection, and skincare property of avocado-fiber knitted fabric, and discusses the comfortability of the fabric, the requirements of underwear fitness, the style design optimization, and the functional area partitioning, aiming to provide design ideas for the development of the new skincare functional knitted underwear.
Settlement simulation of soft clay in the subway under dynamic load based on Midas GTS NX
Authors: Cao Quan , Hang Yu
Published: February 2021

The subway has become the main way for people to travel nowadays. The saturated soft clay area has a large population and subway construction is the most extensively distributed. The saturated soft clay foundation will settle under the dynamic load of the subway train, which will affect the service life and structural safety. To study the settlement characteristics of soft clay under the dynamic load of the subway, a three-dimensional dynamic finite element model was established based on the finite element software Midas GTS NX, and the soft clay under the normal design speed (80 km/h) and the high-speed (120 km/h) were compared and analyzed. The research results show that the higher the train speed, the larger the lateral influence range of the surface settlement trough, but the settlement decreases with the increase of the subway running speed. The settlement of the subway line after one year of operation is about 45mm, and the settlement after 20 years is about 58mm. The growth rate of the settlement prediction curve decreases gradually, and the settlement increment is very small for a long time in the later period of operation.
Analysis of urban spatial cognition in Luzhou city based on city image theory
Authors: Lu Lin , Jiang Peijia , Zhang Xu , Zhao Yu
Published: February 2021

This paper uses the methods of picture recognition, sketch map and questionnaire to understand the citizens’ evaluation of Luzhou’s urban environment, obtain the overall city image and influencing factors to explore the spatial composition and city characteristics of Luzhou.Based on the analysis of the deficiencies in the process of urban development, this paper puts forward some appropriate suggestions to construct a good city image of luzhou city space.
Design on smart water meter system based on Cloud Computing
Authors: Feng Xiye , Zang Dawei , Yan Lelin , Xie Wenfeng , Zhu Hailin , Yin Xiaoyan , Xu Meihui
Published: February 2021

The smart water meter based on cloud computing is a new instrument that uses modern sensor technology, communication technology and modern microelectronics technology to measure water volume, transfer water data and settle transactions. The traditional water meter only has the function of flow collection and pointer mechanical display of water consumption. Compared with traditional water meter, smart water meter has great progress. With the development of wireless transmission technology and mobile communication network, remote water meter technology begins to develop rapidly.
Comparison of Vertical Breast Displacement during Rope Skipping, Walking, Jogging and Running
Authors: Sheng X , Chen X , Li Y , Sun G , Xie H
Published: February 2021

In order to investigate the effect of exercise modality and bra type on vertical breast displacement, seven participants with similar ages and body types were selected to take part in this study. Three-dimensional motion capture system (NDI Optotrak Certus) was used to collect the data of vertical breast displacement when participants were walking at the speed of 5 km/h, jogging at the speed of 7.5 km/h, running at the speed of 10 km/h on a treadmill, and rope skipping at the frequency of twice per second. It was found that there was no significant difference in vertical breast displacement between rope skipping, jogging and running. And the vertical breast displacement when wearing sports bra is significantly less than everyday bra in four exercise modalities. The results of this study might be useful for designing special sports bra for rope skipping modality.
Taiwan’s Ecological Footprint, 2012-2018
Authors: Lee Yung-Jaan , Wu Po-Shu , Chai Lei
Published: February 2021

The Ecological Footprint (EF) is a measurement broadly adopted by the international community to measure the progress toward sustainability. Taiwan’s EF methods refer to the annual reports of the Global Footprint Network (GFN). Therefore, the calculation method closely follows international trends and is updated accordingly. Since the first calculation of Taiwan’s EF in 1998, Taiwan’s EF has been revised several times. At present, the EF from 1994 to 2011 can be obtained. The purpose of this study is to update Taiwan’s EF from 2012 to 2018. This study divides the biologically productive lands into six categories. Since there are two different data sources for fishing grounds and carbon emissions, Taiwan’s EF can be calculated with four different results. Overall, Taiwan’s EF shows a slow downward trend from 2012 to 2018. Furthermore, Taiwan’s carbon footprint accounted for about 70% of the EF, followed by the cropland footprint, which accounted for about 20% of the EF. Compared with global trends, Taiwan’s carbon footprint is about 10% higher than the global carbon footprint, indicating that Taiwan’s carbon emissions are higher than the global average. With the global emphasis on carbon reduction, Taiwan needs to focus on improving carbon emissions.
The influence of carbonitriding conditions on microstructure and mechanical properties of 25CrMo4 low-alloy steel
Authors: Ghanem Abdelkarim , Terres Mohamed Ali
Published: February 2021

Carbonitriding is an important industrial process applied for the improvement of the mechanical characteristics of the component of many steels employed in several machines parts like cam shafts, crank shafts and gears to enhance fatigue strength and wear resistance. In this study, the influence of the gaseous carbonitriding on the enhancement of surface characteristics and mechanical properties was investigated using different parameters for low alloy steel. The analysis and characterization of the treated material were carried out employing optical microscopy (OM) and scanning electron microscopy (SEM) and X-ray diffraction methods (retained austenite and residual stresses). Microhardness and tensile tests were performed and the fracture mechanisms of the various materials were ultimately examined and discussed. The main contribution of this research work is to show and optimize the selection of the appropriate parameters for this kind of steel in industrial field. Diffusion mechanism and microstructure proved that the process of high temperature gas carbonitriding allowed enhancing the mechanical properties of material. This process resulted in a rise of the yield strengths and a loss in a pronounced ductility associated with the brittle intergranular fracture surface caused by the nitride precipitation in the grain boundaries.
Wie wird man Uniklinikum? Neue Wege des Medizinstudiums in Deutschland
Authors: Welzel J. , Breuer G. , Geilen C. C. , Raap U. , Schley G. , Schultz E. , Schwarz S. , Stadler R. , Thieme D. , Zouboulis C. C.
Published: February 2021

Die Nachfrage nach Studienplätzen der Humanmedizin übersteigt seit vielen Jahren deutlich das Angebot der staatlichen Medizinfakultäten in Deutschland. Durch den zunehmenden Ärztemangel steigt auf der anderen Seite der Bedarf an ausgebildeten Medizinerinnen und Medizinern. Um diese Lücke zu schließen, wurden in den letzten Jahren zahlreiche Möglichkeiten neu eröffnet, in Deutschland Humanmedizin zu studieren. Neben Neugründungen von Fakultäten sind insbesondere Kooperationen von Kliniken mit europäischen Universitäten und Privatuniversitäten zu nennen. Dieser Beitrag gibt eine Übersicht über die Optionen und Rahmenbedingungen.
Risikostratifizierung für Therapieentscheidungen bei Rheumatoider Arthritis
Authors: Albrecht Katinka , Regierer Anne , Strangfeld Anja
Published: February 2021

Um für die Behandlung der rheumatoiden Arthritis unter der Vielzahl an zugelassenen krankheitsmodifizierenden Antirheumatika die geeignete Therapie auszuwählen, werden Patienten anhand ihres Risikos für einen ungünstigen Krankheitsverlauf stratifiziert. Die Auswahl geeigneter Parameter zur Risikostratifizierung werden in dieser Übersichtsarbeit dargestellt. Beim heutigen Therapieziel einer Remission sind hohe Krankheitsaktivität, Funktionseinschränkungen, Begleiterkrankungen und Übergewicht relevante Faktoren für einen ungünstigen Verlauf. Weitere Einflussfaktoren auf die Therapieentscheidung wie Begleiterkrankungen, Infektionsrisiko und spezielle Risikokonstellationen wie vorausgegangene schwerwiegende Infektionen oder Malignome werden in diesem Artikel diskutiert.
Netzimplantation bei der Chirurgie der Hiatushernie und beim Reflux – Pro
Authors: Nickel Felix , Cizmic Amila , Müller-Stich Beat P.
Published: February 2021

Die Netzaugmentation wird bei der chirurgischen Versorgung der Hiatushernien trotz zahlreicher Vorteile immer noch kontrovers diskutiert. Das Ziel der optimalen chirurgischen Versorgung der symptomatischen Hiatushernien ist es, die fehlerhafte Lage des Magens und anderer nach thorakal verlagerter Organe dauerhaft zu korrigieren und die Notwendigkeit einer riskanteren Reoperation zu verringern. Um zu beurteilen, ob beim Hiatushernienrepair eine Netzaugmentation durchgeführt werden soll, bedarf es einer gründlichen Abwägung des Nutzens im Sinne der Vermeidung von symptomatischen Rezidiven und Reoperationen im Verhältnis zum Risiko netzassoziierter Komplikationen. In dieser Übersichtsarbeit wird eine detaillierte Evaluation der aktuell verfügbaren Evidenz für das Thema Netzaugmentation dargestellt. Die Schlussfolgerung der Übersichtsarbeit ist, dass die Netzaugmentation bei großen Hiatushernien (> 5 cm) und/oder bei paraösophagealer Beteiligung routinehaft eingesetzt
werden sollte. Dadurch werden die Rezidivraten sowie der Bedarf an komplexen Reoperationen mit hohem Komplikationsrisiko verringert. Netzassoziierte Komplikationen sind selten und bei adäquater Implantationstechnik und geeigneten Netzmaterialien weitgehend vermeidbar. Zur weiteren Verbesserung der Evidenzlage sollte es in Zukunft mehr validierte Register- und randomisiert kontrollierte Studien geben.
Ergebnisse der Einführung eines Antibiotic-Stewardship-Programms im stationären Bereich am Beispiel der ambulant erworbenen Pneumonie des Kindes- und Jugendalters
Authors: Haase R. , Baier J. , Cristofolini M. , Scheller K. , Moritz S.
Published: February 2021

Hintergrund Ambulant erworbene („pediatric community-acquired“) Pneumonien des Kindesalters (pCAP) führen häufig zur Anwendung von Antibiotika und Einweisung ins Krankenhaus. Allerdings werden vorhandene Leitlinien in Diagnostik und Therapie nicht immer konsequent durchgesetzt. Die im letzten Jahrzehnt in vielen Krankenhäusern eingeführten Antibiotic-Stewardship-Programme können das Management der pCAP ohne Qualitätsverlust verbessern.

Fragestellung Die vorliegende Analyse untersucht, inwiefern die Implementierung eines Antibiotic-Stewardship (ABS)-Programms konkret die Leitlinien-Adhärenz bei gleichbleibender therapeutischer Sicherheit verbesserte.

Material und Methoden Retrospektive Patientenakten-basierte Analyse des Managements der pCAP bei Kindern im Alter von 90 Tagen bis zum vollendeten 18. Lebensjahr von Januar 2017 bis März 2020 in einer Universitätskinderklinik vor und nach Umsetzung eines ABS-Maßnahmenbündels, bestehend aus Standarderstellung, fortlaufender Schulung und kontinuierlichem ABS-Support.

Ergebnisse Insgesamt wurden 230 Patienten in die Analyse eingeschlossen (145 vor und 85 nach Intervention). Der Anteil nicht indizierter Antibiotikabehandlungen sank von 26 % auf 10 % (p < 0,05) und der nicht rationalen Antibiotikaanwendungen von 64 % auf 27 % (p < 0,05) bei gleichbleibendem Gesamtanteil von mit Antibiotika stationär behandelten Kindern. Darüber hinaus wurde ein Rückgang von Dosierungsfehlern von 17 % auf 10 % (p < 0,05) und der mittleren antibiotischen Behandlungsdauer von 10 auf 7 Tage (p < 0,05) gesehen. Die Verweildauer im Krankenhaus unterschied sich zwischen beiden Gruppen nur unwesentlich. Ein Anstieg von Therapieversagen oder Wiederaufnahmen aufgrund respiratorischer Infektionen wurde nicht beobachtet.

Schlussfolgerung In Übereinstimmung mit der Literatur konnten wir zeigen, dass ABS-Programme ein geeignetes und sicheres Mittel zur Verbesserung der stationären Therapie der pCAP darstellen. Sie verbessern die Umsetzung klinischer Leitlinien und führen zu einem rationaleren Antibiotikaeinsatz ohne Verschlechterung der Behandlungsergebnisse. Langfristige Effekte derartiger Programme sollten in multizentrischen Untersuchungen analysiert werden.
Management of Intussusceptions Secondary to Pathological Lead Points in Infants and Children
Authors: Ghritlaharey Rajendra K.
Published: February 2021

Objectives

This study was undertaken to investigate and review the age, sex, clinical presentation, surgical procedures done, major postoperative complications, and the final outcome of infants and children operated for intussusceptions secondary to pathological lead points (PLPs).

Materials and Methods

This is a single-institution, retrospective study and included infants and children below the age of 12 years who were operated for the secondary intussusceptions. This study was conducted at author's Department of Paediatric Surgery during the last 20 years; from January 1, 2000 to December 31, 2019.

Results

During the study period, 200 infants and children were operated for the intussusceptions, and 23 (11.5%) of them were operated for the intussusceptions secondary to PLPs. This review comprised 18 (78.26%) boys and 5 (21.73%) girls, and consisted of infants (n = 9, 39.13%) and children of 1 to 5 years of age (n = 7, 30.43%) and 6 to 12 years of age (n = 7, 30.43%). The age at presentation ranged from 3 months to 10 years, with the mean age of 41.47 ± 40.06 months. Clinically, all the children presented with features of acute intestinal obstruction. Ultrasonography (USG) examination of the abdomen revealed the diagnosis of intussusception in all of them but not able to document the PLPs as a cause for it. During the exploratory laparotomies, gangrenous bowel was detected in 15 (65.21%) cases. PLPs causing intussusceptions were Meckel's diverticulum (n = 17, 73.91%), begin ileal growth (n = 4, 17.39%), benign ileal polyp (n = 1, 4.34%), and caecal lymphoma (n = 1, 4.34%). Surgical procedures were executed in the following order of frequency: (1) resection of segment of ileum including PLP, and ileoileal anastomosis (n = 13, 56.52%); (2) resection of segment of ileum including PLP, caecum and part of ascending colon, and ileoascending anastomosis (n = 5, 21.73%); (3) Meckel's diverticulectomy (n = 3, 13.04%); and (4) resection of segment of ileum including PLP and terminal ileostomy (n = 2, 8.69%). This study documented two (8.69%) deaths in postoperative period.

Conclusion

Meckel's' diverticulum was the commonest pathology for the secondary intussusceptions in infants and children and documented most frequently during infancy. Half of the secondary intussusceptions occurred within 24 months of age. Bowel resection was required in more than 85% of the cases during the surgical procedures.
Heptagon-Containing Saddle-Shaped Nanographenes: Self-Association and Complexation Studies with Polycyclic Aromatic Hydrocarbons and Fullerenes
Authors: David Arthur H. G. , Míguez-Lago Sandra , Cruz Carlos M. , Cuerva Juan M. , Blanco Victor , Campaña Araceli G.
Published: February 2021

Supramolecular interactions between molecules of the same or different nature determine to a great extent the degree of their applicability in many fields of science. To this regard, planar polycyclic aromatic hydrocarbons (PAHs) and their nanometric congeners, nanographenes (NGs), as well as positively curved ones, as for instance corannulene, have been extensively explored. However, negatively curved saddle-shaped NGs have remained a curiosity to date within this field. Therefore, here we communicate the first systematic study on the supramolecular behavior of heptagon-containing hexa-peri-hexabenzocoronene analogues. Thus, their self-association and host–guest complexation processes with both flat and curved PAHs, and fullerenes have been studied by means of 1H and 13C NMR titrations in solution, identifying C70 as one of the guests with the highest association constant among all the ones tested.
Plasma Exchange in Refractory Acute Disseminated Encephalomyelitis Associated with COVID-19: Technical Challenges in a Developing Country
Authors: Raut Sumantra Kumar , Sarkar Mihir , Khemka Arpita , Datta Kalpana , Nandi Mousumi , Biswas Durba , Sutar Dipankar , Banerjee Arundhati
Published: February 2021

Evaluation of acquired demyelinating syndrome (ADS) without diagnostic biomarkers results in diagnostic and therapeutic challenges in pediatric population. Immune-mediated ADS of childhood responds well to steroid and intravenous immunoglobulin (IVIg) and in refractory cases with plasma exchange. Novel coronavirus disease 2019 (COVID-19) coinfection in such cases imposes technical challenges in management. An 11-year-old girl with quadriparesis and loss of vision and a magnetic resonance imaging (MRI) brain showing acute demyelinating encephalomyelitis (ADEM) and cerebrospinal fluid examination being noncontributory responded well with plasma exchange after failing steroid and IVIg is described. Coinfection with COVID-19 mandating personal protection in a temperate country imposed technical challenges in her management.
Evaluation of the Effect of Conventional Rhinoplasty with Autospreader Flap and Let-Down Technique on Nasal Functions
Authors: Taş Burak Mustafa , Erden Burak
Published: February 2021

Let-down technique, in which high septal strip resection is performed, and conventional rhinoplasty using autospreader flaps were compared regarding nasal functions with Nasal Obstruction Symptom Evaluation (NOSE) and Sinonasal Outcome Test-22 (SNOT-22) quality-of-life scale questionnaires. A total of 54 patients who were included in the study were divided into two groups: group 1 (autospreader group; n = 27) and group 2 (let-down group; n = 27). Open technical septorhinoplasty operation using an autospreader flap was performed in group 1. Let-down rhinoplasty was applied in group 2. NOSE and SNOT-22 scales were filled for the groups in the preoperative and postoperative periods and were compared. Postoperative values were found to be significantly lower than preoperative values in both groups (p < 0.001). When the groups were compared in between, no significant difference was seen according to the scales (p > 0.05). There was also no significant difference between the groups regarding age and gender. Although there was no significant difference between the two techniques, both NOSE and SNOT-22 quality-of-life scales have shown improvement both in conventional rhinoplasty with autospreader flap and let-down technique.
Effects of wing-to-body mass ratio on insect flapping flights
Authors: Xu Ru , Zhang Xiangdong , Liu Hao
Published: February 2021

Bio-flyers of insects, birds, and bats are observed to have a broad range of wing-to-body mass ratio (WBMR) from 0.1% to 15%. The WBMR and wing mass distribution can lead to large inertial forces and torques in fast-flapping wings, particularly in insect flights, comparable with or even greater than aerodynamic ones, which may greatly affect the aerodynamic performance, flight stability, and control, but still remain poorly understood. Here, we address a simulation-based study of the WBMR effects on insect flapping flights with a specific focus on unraveling whether some optimal WBMR exists in balancing the flapping aerodynamics and body control in terms of body pitch oscillation and power consumption. A versatile, integrated computational model of hovering flight that couples flapping-wing-and-body aerodynamics and three degree of freedom body dynamics was employed to analyze free-flight body dynamics, flapping aerodynamics, and power cost for three typical insects of a fruit fly, a bumblebee, and a hawkmoth over a wide range of Reynolds numbers (Re) and WBMRs. We found that the realistic WBMRs in the three insect models can suppress the body pitch oscillation to a minimized level at a very low cost of mechanical power. We further derived a scaling law to correlate the WBMR with flapping-wing kinematics of stroke amplitude (Φ), flapping frequency (f), and wing length (R) in terms of ΦRf2−1, which matches well with measurements and, thus, implies that the WBMR-based body pitch minimization may be a universal mechanism in hovering insects. The realistic WBMR likely offers a novel solution to resolve the trade-off between body-dynamics-based aerodynamic performance and power consumption. Our results indicate that the WBMR plays a crucial role in optimization of flapping-wing dynamics, which may be useful as novel morphological intelligence for the biomimetic design of insect- and bird-sized flapping micro-aerial vehicles.
On current blockade upon analyte translocation in nanopores
Authors: Wen Chenyu , Zhang Shi-Li
Published: February 2021

Nanopore sensing primarily concerns quantifying the amplitude and shape of blockage current as well as the frequency of translocation events by analyzing the variation of the ionic current upon analyte translocation in a nanopore that represents an extremely simple device structure. To facilitate such an analysis, most reported physical-phenomenological models focus on geometrical factors. Here, we systematically analyze several other factors that may influence the amplitude and waveform of the blockage current. Our theoretical analysis starts with an analytical model based on geometry. It is then extended to include effects of surface conductance, electroosmotic flow, ionic concentration polarization, and induced charge on nanopore membranes. This approach allows for the examination of related electrokinetic and electrohydrodynamic aspects of analyte translocation in nanopores. The model results are confirmed using numerical simulation. The principal outcome of our theoretical scrutiny includes the identification of the respective determinatives of various factors as well as criteria for safely neglecting some of them when correlating the amplitude and waveform of blockage current to the properties of the translocating analyte. Our attempt to categorize these factors can be of practical implications in understanding the translocation process and for developing advanced data analysis algorithms as an effort to promote nanopore sensor applications.
Anisotropic in-plane dielectric and ferroelectric properties of tensile-strained BaTiO3 films with three different crystallographic orientations
Authors: Raeder Trygve M. , Holstad Theodor S. , Nylund Inger-Emma , Einarsrud Mari-Ann , Glaum Julia , Meier Dennis , Grande Tor
Published: February 2021

Ferroelectric properties of films can be tailored by strain engineering, but a wider space for property engineering can be opened by including crystal anisotropy. Here, we demonstrate a huge anisotropy in the dielectric and ferroelectric properties of BaTiO3 films. Epitaxial BaTiO3 films deposited on (100), (110), and (111) SrTiO3 substrates were fabricated by chemical solution deposition. The films were tensile-strained due to thermal strain confirmed by the enhanced Curie temperature. A massive anisotropy in the dielectric constant, dielectric tunability, and ferroelectric hysteresis loops was observed depending on the in-plane direction probed and the orientation of the films. The anisotropy was low for (111) BaTiO3, while the anisotropy was particularly strong for (110) BaTiO3, reflecting the low in-plane rotational symmetry. The anisotropy also manifested at the level of the ferroelectric domain patterns in the films, providing a microscopic explanation for the macroscopic response. This study demonstrates that the properties of ferroelectric films can be tailored not only by strain but also by crystal orientation. This is particularly interesting for multilayer stacks where the strain state is defined by the boundary conditions. We propose that other materials can be engineered in a similar manner by utilizing crystal anisotropy.
Analog of electromagnetically induced transparency in metasurfaces composed of identical dielectric disks
Authors: Jamilan Saeid , Semouchkin George , Semouchkina Elena
Published: February 2021

An analog of electromagnetically induced transparency was revealed in metasurfaces (MSs), composed from identical dielectric resonators of simple cylindrical shapes. It was detected in numerical experiments at optical and microwave frequencies and confirmed by real experiments in the microwave range. The main specific of the observed phenomenon was its appearance at frequencies of electric dipolar resonances (EDRs) in MS elements, when total reflection of incident waves instead of transmission was expected. Investigations of electric field distributions in MSs allowed for detecting several Fano resonances caused by interaction between background radiation defined by incident waves, and radiation produced by oscillations of resonance fields in dielectric particles. The characteristics for EDR changes in phases of resonance oscillations by π radians were found controlling the transitions from constructive to destructive interference between participating wave processes. The onset of destructive interference was marked by sharp jumps by π radians in the spectra of signal phases. Performed analysis revealed that zero signals at Fano resonances, observed in the gaps between resonators, arranged along the electric field direction, could serve as indicators of realizing the conditions necessary for the transparency of MSs. These conditions included the elimination of the presence of background radiation and thus of interaction between trespassing waves and MSs.
Investigation of coherence properties of white light emission of tungsten lamp additionally excited with laser radiation
Authors: Hanulia T. , Oleszko M. , Tomala R. , Strek W.
Published: February 2021

The coherence properties of white light emission of a tungsten incandescent lamp additionally excited with laser radiation are investigated. The degree of spatial coherence is determined from measurements of the contrast of interference fringe patterns obtained for a tungsten bulb as the light source. It is demonstrated that the degree of spatial coherence of an incandescent lamp is increased by additional excitation of the filament with focused laser radiation. Furthermore, the degree of spatial coherence can be adjusted by selecting the voltage applied to the filament. Such light sources can find applications in imaging techniques where precise control of spatial coherence of illumination is required.
Interface degradation and field screening mechanism behind bipolar-cycling fatigue in ferroelectric capacitors
Authors: Do M. T. , Gauquelin N. , Nguyen M. D. , Blom F. , Verbeeck J. , Koster G. , Houwman E. P. , Rijnders G.
Published: February 2021

Polarization fatigue, i.e., the loss of polarization of ferroelectric capacitors upon field cycling, has been widely discussed as an interface related effect. However, mechanism(s) behind the development of fatigue have not been fully identified. Here, we study the fatigue mechanisms in Pt/PbZr0.52Ti0.48O3/SrRuO3 (Pt/PZT/SRO) capacitors in which all layers are fabricated by pulsed laser deposition without breaking the vacuum. With scanning transmission electron microscopy, we observed that in the fatigued capacitor, the Pt/PZT interface becomes structurally degraded, forming a 5 nm–10 nm thick non-ferroelectric layer of crystalline ZrO2 and diffused Pt grains. We then found that the fatigued capacitors can regain the full initial polarization switching if the externally applied field is increased to at least 10 times the switching field of the pristine capacitor. These findings suggest that polarization fatigue is driven by a two-step mechanism. First, the transient depolarization field that repeatedly appears during the domain switching under field cycling causes decomposition of the metal/ferroelectric interface, resulting in a non-ferroelectric degraded layer. Second, this interfacial non-ferroelectric layer screens the external applied field causing an increase in the coercive field beyond the usually applied maximum field and consequently suppresses the polarization switching in the cycled capacitor. Our work clearly confirms the key role of the electrode/ferroelectric interface in the endurance of ferroelectric-based devices.
Multiple ion temperature effects on collisionless magnetic reconnection
Authors: Mao Aohua , Wang Zhibin
Published: February 2021

Plasmas with a component of low-temperature (colder) ions are frequently observed in solar-terrestrial space with plasmaspheric and ionospheric origins. In addition, in fusion plasmas, massive fueling in the burning plasma provides a colder ion source in the fueling region. Therefore, such mixtures of multiple-temperature ions are common and inevitable in plasmas. In this paper, we focus on multiple ion temperature effects on magnetic reconnection by two-dimensional particle-in-cell simulations. Two typical scenarios are discussed. From group 1 runs, it can be found that if the colder ion density is increased but the warmer ion density is kept the same, the reconnection rate is reduced and the onset of the fast reconnection is delayed, mainly due to the mass-loading effect. Meanwhile, an additional spatial scale is introduced by the multi-temperature ions to form a nested structure of diffusion regions of the electrons, as well as colder and warmer ions, which are demagnetized (inflow) and remagnetized (outflow) in different spatial positions and accelerated to different levels. For the three species, the closer accessible position from the X-point is that the higher speed can be reached by acceleration in the diffusion regions. On the other hand, from group 2 runs, it can be found that if one keeps the total background ion density fixed while only changing the ratio of the warmer to the colder ions, the mass-loading effect can then be ignored. As the colder ion proportion increases, the peak inflows and outflows of both warmer and colder ions are getting higher as more ions can get closer to the X-point, leading to the rise of the reconnection rate with reconnection characteristics undergoing a transition from the warmer ion dominant to the colder ion dominant.
Two types of corner states in two-dimensional photonic topological insulators
Authors: Li Mingxing , Wang Yueke , Lu Mengjia , Sang Tian
Published: February 2021

Higher-order topological insulators, which go beyond the conventional bulk-boundary correspondence, have become a hot research topic in recent years. In this paper, we propose a two dimensional second-order topological photonic crystal based on a C4 symmetric lattice. By tuning the distance between the dielectric cylinders, the topological phase transition of the structure is realized, one edge state and two types of corner states (one topological and one trivial corner state) are found. Our findings provide an evolution of bulk–corner–edge–corner–bulk in a hierarchy of dimensions, which enriches the study of corner states in photonic systems. Besides, we distinguish two corner states by discussing robustness and mode area, and we verify the topological corner state can be embedded in the bulk states, forming a bound state in continuum by simulation.
Simulation-based study of COVID-19 outbreak associated with air-conditioning in a restaurant
Authors: Liu Han , He Sida , Shen Lian , Hong Jiarong
Published: February 2021

COVID-19 has shown a high potential of transmission via virus-carrying aerosols as supported by growing evidence. However, detailed investigations that draw direct links between aerosol transport and virus infection are still lacking. To fill in the gap, we conducted a systematic computational fluid dynamics (CFD)-based investigation of indoor airflow and the associated aerosol transport in a restaurant setting, where likely cases of airflow-induced infection of COVID-19 caused by asymptomatic individuals were widely reported by the media. We employed an advanced in-house large eddy simulation solver and other cutting-edge numerical methods to resolve complex indoor processes simultaneously, including turbulence, flow–aerosol interplay, thermal effect, and the filtration effect by air conditioners. Using the aerosol exposure index derived from the simulation, we are able to provide a spatial map of the airborne infection risk under different settings. Our results have shown a remarkable direct linkage between regions of high aerosol exposure index and the reported infection patterns in the restaurant, providing strong support to the airborne transmission occurring in this widely reported incident. Using flow structure analysis and reverse-time tracing of aerosol trajectories, we are able to further pinpoint the influence of environmental parameters on the infection risks and highlight the need for more effective preventive measures, e.g., placement of shielding according to the local flow patterns. Our research, thus, has demonstrated the capability and value of high-fidelity CFD tools for airborne infection risk assessment and the development of effective preventive measures.
r2SCAN-D4: Dispersion corrected meta-generalized gradient approximation for general chemical applications
Authors: Ehlert Sebastian , Huniar Uwe , Ning Jinliang , Furness James W. , Sun Jianwei , Kaplan Aaron D. , Perdew John P. , Brandenburg Jan Gerit
Published: February 2021

We combine a regularized variant of the strongly constrained and appropriately normed semilocal density functional [J. Sun, A. Ruzsinszky, and J. P. Perdew, Phys. Rev. Lett. 115, 036402 (2015)] with the latest generation semi-classical London dispersion correction. The resulting density functional approximation r2SCAN-D4 has the speed of generalized gradient approximations while approaching the accuracy of hybrid functionals for general chemical applications. We demonstrate its numerical robustness in real-life settings and benchmark molecular geometries, general main group and organo-metallic thermochemistry, and non-covalent interactions in supramolecular complexes and molecular crystals. Main group and transition metal bond lengths have errors of just 0.8%, which is competitive with hybrid functionals for main group molecules and outperforms them for transition metal complexes. The weighted mean absolute deviation (WTMAD2) on the large GMTKN55 database of chemical properties is exceptionally small at 7.5 kcal/mol. This also holds for metal organic reactions with an MAD of 3.3 kcal/mol. The versatile applicability to organic and metal–organic systems transfers to condensed systems, where lattice energies of molecular crystals are within the chemical accuracy (errors <1 kcal/mol).
Role of 3d–4f exchange interaction and local anti-site defects in the magnetic and magnetocaloric properties of double perovskite Ho2CoMnO6 compound
Authors: Mazumdar Dipak , Das I.
Published: February 2021

The strong coupling between 3d and 4f based magnetic sublattices in double perovskite (DP) compounds results in various exotic complex magnetic interactions, and the ground state contains multiple fascinating and remarkable magnetic states. In this article, we have performed a detailed investigation of the crystal structure, magnetic, and magnetocaloric properties of the ordered monoclinic polycrystalline double perovskite Ho2CoMnO6 (HCMO) compound. A study of the magnetization dynamics employing temperature and magnetic field shows a powerful correlation between Ho and Co/Mn sublattices. Due to the presence of the ferromagnetic superexchange interaction in between Co2+−O−Mn4+ networks, the system undergoes an ordered state at the transition temperature, TC≈77K. Below TC, a clear compensation point continued by negative magnetization is noticed in the virgin state of the compound. The reduction of the saturation magnetization (MS) in the hysteresis curves (M-H) can be explained by the existence of local anti-site defects or disorders and anti-phase boundaries in the system. Temperature dependence of magnetic entropy change (−ΔS) curves shows a maximum value of 13.4 J/kg K for ΔH=70kOe at a low temperature along with a noticeable inverse magnetocaloric effect. Moreover, the material holds reasonable values of magnetocaloric parameters. The absence of thermal hysteresis along with a large value of |ΔS| makes the system a potential candidate for low temperature as well as liquid nitrogen temperature-based magnetic refrigeration. Additionally, our experimental findings should encourage further detailed studies on the complex 3d–4f exchange interaction in the double perovskite system.
Temperature-dependent collective magnetization reversal in a network of ferromagnetic nanowires
Authors: Lendínez Sergi , Pearson John E. , Hoffmann Axel , Novosad Valentyn , Jungfleisch M. Benjamin
Published: February 2021

The collective behavior of geometrically frustrated magnetization in connected networks of ferromagnetic nanowires, known as artificial spin ice, leads to complex magnetotransport behavior in those structures. Here, we present temperature- and current-dependent magnetotransport studies on a connected square artificial spin-ice system and correlate our observations to micromagnetic simulations. We find that the field at which the lattice magnetization collectively switches increases as the temperature is lowered. Our experimental findings highlight the importance of the global and local temperatures for the onset of a collective magnetization reversal in the connected system. These studies may also provide useful insights into novel storage concepts and applications in neuromorphic computing.