bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of RHO zeolite with different cations for CO2/CO separation in pressure swing adsorption
Authors: Liang Dan , Hu Yunfeng , Bao Qiang , Zhang Jian , Sun Penglai , Feng Jiawei , Xu Ming , Zhang Hongsheng
Published: March 2021

A series of cation‐exchanged RHO zeolites, including H‐RHO, Li‐RHO, Na‐RHO, K‐RHO, Cs‐RHO, Cd‐RHO and Pb‐RHO, were prepared, and the samples were characterised by X‐ray diffraction, scanning electron microscopy, energy dispersive X‐ray spectroscopy, thermogravimetric analysis, inductive coupled plasma emission spectrometer and N2‐BET. The CO2 and CO adsorption behaviours of the samples were measured at 298 K and 0–10 bar. The Langmuir equation was used to fit adsorption isotherms to compare the separation effect of these RHO zeolites. The results show that extra‐framework cations can effectively adjust the pore size of RHO. Not only it depends on the size of the cation radius, but other factors also play an important role, such as the position of the cation. Besides, compared with CHA structure, RHO structure has better CO2/CO separation performance. In all researched cationic forms of RHO, Li‐RHO, Cd‐RHO and Pb‐RHO have excellent CO2/CO separation effects. Among them, the pore size of Cd‐RHO is significantly reduced, thereby restricting the entry of CO more effectively, ultimately leading to greater shape selectivity. Cd‐RHO not only has the highest CO2 saturated adsorption capacity and CO2 working capacity but also has relatively excellent CO2/CO selectivity, resulting in the sorbent selection parameter (S) is also the largest.
Model predictive control of a hybrid stacked multicell converter with voltage balancing and fault tolerance capability
Authors: Xu Shuai , Sun Zhenyao , Yao Chunxing , Liu Kang , Ma Guangtong
Published: March 2021

Due to the merits of low conduction losses and superior output power quality, a hybrid stacked multicell converter (HSMC) was put forward as a competitive alternative in the medium/low‐voltage high‐efficiency applications. A nine‐level HSMC (9L‐HSMC) can be seen as a combination of a five‐level SMC (5L‐SMC) and two‐level half‐bridge, and proper modulation and control strategy are essential for the HSMC to obtain the optimal output performance. This work develops a finite control‐set model predictive control (MPC) strategy for 9L‐HSMC to balance the capacitor voltages and maintain the desired outputs, rendering the absence of the linear regulator and pulse width modulation (PWM) modulator possible. The fault‐tolerant operation can also be achieved flexibly when open‐circuit faults occur at active bidirectional switches in the 5L‐SMC bridge, and the performance is verified by simulations. Finally, experiments under several typical operating conditions are implemented to verify the effectiveness of 9L‐HSMC with the developed MPC strategy.
Analysis of multi‐constellation GNSS receiver performance utilizing 1‐st side‐lobe signal on the use of SSV for KPS satellites
Authors: Ji Gun‐Hoon , Shin Heon , Won Jong‐Hoon
Published: March 2021

A numerical analysis is conducted for assessing the feasibility on the use of Global Navigation Satellite System (GNSS) receivers for Korea Positioning System (KPS) satellites in space service volume (SSV). KPS is planned to provide a navigation and timing service by constructing seven satellites over the Korean Peninsula, which will orbit above the GNSS constellation in SSV. The major problems caused by such orbital characteristics include reduced satellite visibility due to poor geometric diversity and weak signals, causing an increase in the user range error (URE). To address these constraints, this study considers multi‐GNSS and 1‐st side‐lobe signal utilization scenarios. More specifically, the GNSS satellite visibility, geometric dilution of precision, carrier‐to‐noise ratio, URE, and navigation error for KPS satellites in SSV are analysed through a numerical simulation. A trade‐off between visibility and received signal power as well as their effects on positioning accuracy is analysed to describe the utility of side‐lobe signals. Finally, based on numerical analysis of the simulation results, this verifies the applicability of GNSS SSV for KPS satellites through multi‐GNSS and side‐lobe utilization scenarios.
(208) Lacrimosa: A case that missed the Slivan state?
Authors: Vokrouhlický D. , Ďurech J. , Hanuš J. , Ferrais M. , Jehin E. , Benkhaldoun Z.
Published: March 2021

Context.The largest asteroids in the Koronis family (sizes ≥25 km) have very peculiar rotation state properties, with the retrograde- and prograde-rotating objects being distinctly different. A recent re-analysis of observations suggests that one of the asteroids formerly thought to be retrograde-rotating, 208 Lacrimosa, in reality exhibits prograde rotation, yet other properties of this object are discrepant with other members this group.

Aims.We seek to understand whether the new spin solution of Lacrimosa invalidates the previously proposed model of the Koronis large members or simply reveals more possibilities for the long-term evolutionary paths, including some that have not yet been explored.

Methods.We obtained additional photometric observations of Lacrimosa, and included thermal and occultation data to verify its new spin solution. We also conducted a more detailed theoretical analysis of the long-term spin evolution to understand the discrepancy with respect to the other prograde-rotating large Koronis members.

Results.We confirm and substantiate the previously suggested prograde rotation of Lacrimosa. Its spin vector has an ecliptic longitude and latitude of (λ,β) = (15° ± 2°, 67° ± 2°) and a sidereal rotation periodP= 14.085734 ± 0.000007 h. The thermal and occultation data allow us to calibrate a volume equivalent size ofD= 44 ± 2 km of Lacrimosa. The observations also constrain the shape model relatively well. Assuming uniform density, the dynamical ellipticity is Δ = 0.35 ± 0.05. Unlike other large prograde-rotating Koronis members, Lacrimosa spin is not captured in the Slivan state. We propose that Lacrimosa differed from this group in that it had initially slightly larger obliquity and longer rotation period. With those parameters, it jumped over the Slivan state instead of being captured and slowly evolved into the present spin configuration. In the future, it is likely to be captured in the Slivan state corresponding to the proper (instead of forced) mode of the orbital plane precession in the inertial space.
Research on Forecasting Method of Distribution Network Investment Scale of Municipal Power Supply Enterprise Considering Power Supply Division and Cost Difference Level
Authors: Quanfeng Gou , Jie Yang , Fei Zhou , Lin Hu , Guangxiu Yu , Qian Li , Le Du
Published: March 2021

In recent years, in order to adapt to the situation of rapid economic and social development, my country’s power supply companies have invested large-scale funds to build distribution networks, and upgraded urban and rural power grids, effectively supporting the rapid growth of power demand and the reliability of power supply. Continuous improvement of power quality. While the scale of investment in the distribution network continues to remain high, problems such as focusing on investment and neglecting revenue, focusing on project establishment and neglecting management also exist to varying degrees. Therefore, reasonably predicting the scale of investment in the distribution network and improving the lean management level of the investment and construction of the distribution network have become key issues that power supply companies need to solve. This paper takes my country’s municipal power supply companies as the research object, combines the actual business development of the company’s distribution network investment planning, and fully considers the impact of the company’s power supply district management and the level of cost differences on the investment scale of the distribution network, and builds a fit on this basis. The distribution network investment planning forecast model of the actual business work of the enterprise guides the municipal power supply enterprises to improve the lean management level of the distribution network investment and construction.
Research on China’s Energy External Dependence and Energy Strategy
Authors: Lulu Yu , Zhao Li
Published: March 2021

After the reform and opening up, with the rapid development of economy and science and technology, high-tech products such as high-speed railway, train, aircraft, missile and rocket appear in response to the times. As people’s living standards develop, they have a high consumption demand towards energy. For example, coal gas and natural gas take the place of firewood, and various new energy such as wind energy, tidal energy and solar energy emerge. China is now seeing a rapid industrialization. Although the amount of China’s energy is large, the rigid demand of energy remains tense in supply and demand. Relatively speaking, China has a high energy external dependence, thus a series of measures were launched such as greatly advocating the implementation of new energy and reducing the exploitation quantity of coal properly. This paper will analyze the import and export data of various kinds of energy from 2015 to 2019 and calculate the external dependence level in 2019. After analyzing the current situation in China and consulting the national policies and information, the author will put forward suggestions on the current situation of China’s energy.
Exploration of Intellectual Property Protection Strategies for Cross-border E-commerce
Authors: Lin ChunYi
Published: March 2021

Abstract—

The continued advancement of the “One Belt, One Road” strategy, coupling with the rapid development of the Internet, has provided a convenient online platform for cross-border e-commerce enterprises. China’s cross-border e-commerce enterprises have made unprecedented progress. However, at the same time, the problem of intellectual property infringement in cross-border e-commerce has become increasingly prominent, seriously restricting the development of China’s cross-border e-commerce enterprises. On the basis of analyzing the intellectual property strategy of enterprises.

This paper describes the necessity of creating an intellectual property strategy for cross-border e-commerce enterprises, and proposes strategies for building relevant intellectual property strategies aimed at the weak awareness of intellectual property and the copycatting of enterprise products, which are common in the operation of cross-border e-commerce enterprises in China.
Concentration Polarization of High Concentration Solution in Sub-nm Nanopore
Authors: Ji Anping , Chen Yunfei
Published: March 2021

The behavior of ion transport through the sub-nm nanopores on the film is is different from the behavior of bulk behavior. Many intriguing phenomena in ionic transport are the key to the design and fabrication of solid-state nanofluidic devices. However, ion transport through the sub-nm nanopores is not yet clearly understood. We investigate ionic transport of sub-nm nanopore from the perspective of conductance by the method of MD. The results show that the ion concentration polarization phenomenon is heavily dependent on the external electric field and the size constraints of nanopores. At the same time, ion concentration polarization also has a profound effect on ion conductance. These conclusions indicate that ion concentration polarization has an important influence on ion transport, and help a new understanding of the design of nanofluidic devices.
Determination of Limited Aritolonchic Acid A Content in Xinqin Granules by Capillary Electrophoresis
Authors: Liu Fang , Liu Haixing , Han Likun
Published: March 2021

The paper investigated the determination of limited aritolonchic acid A content in Xinqin granules by capillary electrophoresis. The buffer was 30 mmol/L borax solution containing 3% ethanol. The voltage was 16 kV and UV detection wavelength was 250 nm. The aritolonchic acid A content in Xinqin granules was 2.87 mg/g(RSD=2.9%) (n=6). The recovery of aritolonchic acid A in Xinqin granules sample was in the range of 84.5%-126.7% (n=5). The average recovery was 105.9% (n=5). The new method is fit for the determination of limited aritolonchic acid A content in Xinqin granules.
Effects of manganese on growth and development of peanut (Arachis hypogaea L.) seedlings
Authors: Liu Ying , Chen Jingye , Li Xiaohao , Xue Yingbin
Published: March 2021

The effects of different menganses (Mn) concentrations on the growth and development of peanut seedlings were analysed in the present study. The results showed that the main root length, lateral root number, plant height, dry weight of aboveground and underground parts of peanut seedlings were all influenced by the concentrations of Mn obviously. Moreover, the growth of peanut could be significantly promoted at low concentration of Mn (150 μmol/L), while inhibited by high concentration of Mn (900 μmol/L). Therefore, these conclusions could help us to understand the most suitable concentration range of Mn for the growth of peanut, and could also analyze the specific performance of the harm of Mn toxicity on peanut, so as to lay a theoretical foundation for improving the yield of peanut and expanding the cultivation area.
An Intelligent Emotion Device Design Based on the Way of Relieving Psychological Pressure for Chinese Internet Employees
Authors: Qi Yang
Published: March 2021

With the rapid development of Internet companies, a large amount of capital has been continuously invested into this field and the companies have entered a new stage of development. However, the psychological pressure on their employees has continued to increase and various extreme events have emerged one after another, arousing heated social debates. Based on the background, it is worthy to discuss and research how to help Internet workers relieve their psychological pressure and benefit from humanistic practices in business. To explore novel and effective ways to relieve stress for these employees, intelligent interactive devices combine the healing design and feature multi-sensory integration, so as to promote the efficiency of employees and the long-term development of Internet companies.
Using AI to Improve Corporate Governance
Authors: Lin Chien-Cheng , Chang Shih-Feng
Published: March 2021

This paper mainly discusses the relationship between corporate governance and dynamic business performance in semiconductor industry. Although there have been many discussions on the relationship between corporate governance and corporate performance in the past, there is no consistent conclusion. We intend to analyze and compare the corporate governance variables group, the expression of long-term performance and the differences between upstream, midstream and downstream of semiconductor industry. In addition, because the existing problems of corporate governance can not be solved by the current rigid system, we attempt to cut in from the perspective of AI and propose the effect of automatic warning.
Extraction method of weak underwater acoustic signal based on the combination of wavelet transform and empirical mode decomposition
Authors: Shi Junbing , Wang Yingmin , Zhang Xiaoyong , Yang Libo
Published: March 2021

When studying underwater acoustic exploration, tracking and positioning, the target signals collected by hydrophones are often submerged in strong intermittent noise and environmental noise. In this paper, an algorithm that combines empirical mode decomposition and wavelet transform is proposed to achieve the efficient extraction of target signals in the environment with strong noise. First the calibration of baseline drift is performed on the algorithm, and then it is decomposed into different intrinsic mode functions via empirical mode. The wavelet threshold processing is conducted according to the correlation coefficient of each mode component and the original signal, and finally the signals are reconstructed. The simulation and experiment results show that compared with the conventional empirical mode decomposition method and wavelet threshold method, when the signal-to-noise ratio is low and there exist high-frequency intermittent jamming and baseline drift, the combined algorithm can better extract the target signal, laying the foundation for direction-of-arrival estimation and target positioning in the next step.
Influence de la pression de compactage sur les caractéristiques physiques et la durée de combustion de combustible à base de sciure de bois et de liant végétal
Authors: Augou Ovo Sandrine Flora , Ouattara Souleymane , Kouakou Conand Honoré , Kouadio Koffi Clément , Assande Aka Alexandre , Emeruwa Edjikémé
Published: March 2021

Ce travail s’inscrit dans le cadre du recyclage des déchets industriels (sciure de bois). L’élaboration du charbon de bois et la production de la sciure de bois par les scieries en Côte d’Ivoire entraînent des problèmes environnementaux, climatiques et sanitaires. La présente étude propose, une solution palliative à ces problèmes à partir de l’élaboration de charbon dénommé biocharbon, réalisé avec ces déchets. Cependant, le problème prédominant est la pression de compactage optimale pour confectionner les combustibles. Le but de cette étude est de déterminer cette pression de compactage. Les matières premières utilisées sont la sciure de bois de l’Iroko (Chlorophora excelsa) carbonisée et l’amidon de manioc (Manioht exculenta) transformé en empois d’amidon (EA). Pour les agglomérer, quatre formulations de rapport EA/Sb égale à 0,75, 0,87, 1 et 1,125 sont employés avec une pression de compactage variant de 100 à 500 kPa par pas de 100. Les résultats obtenus à partir des essais montrent que les biocharbons élaborés avec la formulation de rapports 0,75 ne sont pas bien consolidés quelque soit la pression de compactage. Ceux de rapport 1,125 ne nécessitent pas de pression de compactage et ceux de rapport 0,87 et 1 se consolident à 500 kPa. Concernant la masse volumique, elle augmente avec la pression de compactage et on observe une perte de matière pour le rapport 1,125 lorsque la pression est supérieure à 300 kPa. Les essais de combustion révèlent la présence d’odeurs et un dégagement de fumée pour les biocharbons de rapport 1,125. Ainsi, pour l’élaboration des biocharbons, les rapports 0,87 et 1 sous une pression de compactage de 500 kPa sont à retenir pour la formulation idéale.
Aufsuchende zahnärztliche Versorgung von Kindern und Jugendlichen mit Pflegegrad oder Eingliederungshilfe – eine Auswertung von Abrechnungsdaten der KZBV
Authors: Schmidt Peter , Fricke Oliver , Schulte Andreas G.
Published: March 2021

Hintergrund Bislang liegen keine Daten vor, inwieweit Kinder und Jugendliche, die einen Pflegegrad haben oder Eingliederungshilfe beziehen (KiJu-PflEh), bei einer aufsuchenden zahnmedizinischen Betreuung und Versorgung berücksichtigt wurden.

Ziel Die Untersuchung von Abrechnungsdaten der Kassenzahnärztlichen Bundesvereinigung (KZBV) zur Inanspruchnahme von Leistungen bei KiJu-PflEh, die zur Behandlung durch einen Zahnarzt aufgesucht wurden.

Material und Methode Auf der Basis von sechs Leistungspositionen (Abrechnungsjahr 2019) wurde von der KZBV eine Filterung der GKV-Versicherten (0–17 Jahre) durchgeführt. Die generierten Datensätze der Studiengruppe (KiJu-PflEh) und der Kontrollgruppe (alle KiJu) wurden zur Aufbereitung anonymisiert der UW/H zur Verfügung gestellt.

Ergebnis Die Studiengruppe umfasste 1602 KiJu-PflEh (mittleres Alter: 11,6 Jahre). Das Geschlechterverhältnis von ♂ zu ♀ war 2:1. Bei 56,0% der KiJu-PflEh wurde eine Befunderhebung oder Beratung abgerechnet. Die Inanspruchnahme individualprophylaktischer (IP) Maßnahmen war wie folgt: Erhebung eines Mundhygienestatus – IP1 (47,5%), Mundgesundheitsaufklärung – IP2 (46,1%), Lokale Fluoridierung der Zähne – IP4 (63,1%), Fissurenversiegelung je Zahn – IP5 (30,1%). Im Vergleich zu KiJu wurden bei KiJu-PflEh statistisch signifikant weniger individualprophylaktische Maßnahmen abgerechnet und ausgeführt (KiJu: 85,7%; KiJu-PflEh: 46,7%).

Schlussfolgerung Erstmals wurde aufgezeigt, dass KiJu-PflEh im Vergleich zu Gleichaltrigen der Allgemeinbevölkerung ungenügend zahnmedizinisch betreut und versorgt sind. Eine Intensivierung ist dringend angeraten, da KiJu-PflEh zur Personengruppe mit einem erhöhten Kariesrisiko zählen. Um gezielt Präventionsangebote für alle KiJu-PflEh zu implementieren, sind auch medizinische Informationen notwendig. Daher ist die Einführung einer Zentraldatenbank, die eine zahn- und allgemeinmedizinische Vernetzung ermöglicht, anzustreben. Ferner besteht ein Bedarf an wissenschaftlichen Projekten zur Erhebung von kariesepidemiologischen Primärdaten bei KiJu-PflEh, um die vorliegenden Aussagen dieser Pilotuntersuchung zu verifizieren.
Homozygous Missense Mutation on Exon 22 of PKHD1 Gene Causing Fatal Autosomal Recessive Polycystic Kidney Disease
Authors: Sathyan Sajina , Pournami Femitha , Madhavilatha Gopala Krishna , Tuteja Amrit , Nandakumar Anand , Prabhakar Jyothi , Jain Naveen
Published: March 2021

Autosomal recessive polycystic kidney disease, described as a congenital hepatorenal fibrocystic syndrome, is a significant inherited cause of end stage renal failure in children with reported incidence of 1 in 20,000 live births. The clinical spectrum is wide. Antenatal findings of echogenic reniform enlarged kidneys associated with evidence of intrauterine renal failure in the form of severe oligoamnios are pathognomonic. Postnatal illness ranges from fatal respiratory failure due to pulmonary hypoplasia in neonates to chronic kidney disease in children, or later presentation of ductal plate malformation and portal hypertension. Advances in genetic diagnostic techniques have allowed recognition of genotypes. We report a novel homozygous missense variant on exon 22 of PKHD1 gene (chr6:51915067G > A; c.2167C > T) that results in the amino acid substitution of cysteine for arginine at codon 723 (p.Arg723Cys). The affected neonate presented with antenatal anhydramnios, classical radiological features, and severe hypoxic respiratory failure likely due to pulmonary hypoplasia and succumbed. The parents were found to be heterozygous carriers. Detection of the specific variant in the proband facilitated prenatal investigation in the next pregnancy.
Surgical Cutdown Avoids Vascular Complications in Transcatheter Aortic Valve Replacement in Calcified and Small Femoral Arteries
Authors: Burri Melchior , Ruge Hendrik , Erlebach Magdalena , Lange Rüdiger
Published: March 2021

Background Third-generation transcatheter heart valves (THV) are predominantly implanted through a percutaneous, transfemoral access. To reduce vascular complications, we selectively performed surgical vascular access (cutdown) in patients with particular calcified or small femoral arteries. We aim to review our experience with this approach.

Methods All patients who underwent transfemoral transcatheter aortic valve replacement (TAVR) with a third-generation THV at our institution between March 2014 and April 2019 were included in the study. All available computerized tomography studies were reassessed for access vessel diameter and visual graduation of calcifications. Vascular complications are reported according to Valve Academic Research Consortium-2 criteria.

Results A total of 944 patients were included. Among them, 879 patients underwent a percutaneous access and 65 patients underwent surgical cutdown. Also, 459 Evolut R/PRO and 420 Sapien 3/ultra were implanted percutaneously and 40 Evolut R/PRO and 25 Sapien 3 were implanted with a surgical cutdown. Patients with surgical cutdown were older (80.0 ± 7.5 vs. 83.8 ± 7.5 years, p < 0.001), had smaller femoral arteries (8.0 ± 1.6 vs. 7.6 ± 1.6 mm, p = 0.034) and more severe vessel calcifications (17.5 vs. 1.0%, p < 0.001). Procedure time was similar for cutdown and percutaneous access (64.0 vs. 64.5 minutes, p = 0.879). With percutaneous access, 80 major vascular complications (10%) occurred, whereas with surgical cutdown, no major vascular complications occurred (p < 0.005). No wound infection occurred after surgical cutdown. The mean length of stay was 8 days in both groups.

Conclusion Surgical cutdown for vascular access avoids vascular complications in patients with small or severely calcified femoral arteries.
Experience with Diagnosis and Management of Distal Radioulnar Joint Instability
Authors: Hearon Bernard F. , Frantz Lisa M. , Helsper Elizabeth A. , Morris Harry A.
Published: March 2021

Objective The aim of this study is to review our cumulative experience with diagnosis and treatment of distal radioulnar joint (DRUJ) instability and to present our treatment algorithm.

Materials and Methods Retrospective review identified 112 patients who had 126 episodes of care for DRUJ instability at a single institution over a 21-year period. Those diagnosed acutely or subacutely were treated with immobilization of the wrist and elbow for 6 weeks, while those with chronic instability had anatomic reconstruction of the dorsal and palmar radioulnar ligaments with tendon autograft or an alternative arthroscopic treatment with our thermal annealing technique. Short-term treatment failures and surgical complications were recorded. Nonparametric statistical tests were used to analyze key long-term outcome measures including ulnar wrist pain and DRUJ stability indicated by the dorsopalmar stress test.

Results At mean 7-year follow-up, eight patients in the acute-injury cohort had statistically significant improvements in wrist pain and DRUJ instability (p < 0.001). In both the 22-patient anatomic reconstruction cohort and the 37-patient arthroscopically treated group, there were also statistically significant improvements in wrist pain and DRUJ stability (p < 0.001) at mean 9-year follow-up. The majority of patients in all three groups was satisfied with treatment outcome, though some required secondary procedures.

Conclusion Early clinical diagnosis of DRUJ instability using the dorsopalmar stress test provides an opportunity for effective nonsurgical treatment. For chronic presentation, we recommend our arthroscopic thermal annealing technique for mild or moderate instability and open anatomic reconstruction of the radioulnar ligaments for severe instability.

Level of Evidence This is a Level IV, therapeutic study.
Correction: Active teachers’ perceptions on the most suitable resources for teaching history
Authors: Guerrero-Romera Catalina , Sánchez-Ibáñez Raquel , Escribano-Miralles Ainoa , Vivas-Moreno Verónica
Published: March 2021

A Correction to this paper has been published: https://doi.org/10.1057/s41599-021-00768-z
Strongly anisotropic field emission from highly aligned carbon nanotube films
Authors: Fairchild S. B. , de Assis Thiago A. , Park J. H. , Cahay M. , Bulmer J. , Tsentalovich D. E. , Ang Yee Sin , Ang L. K. , Ludwick J. , Back T. C. , Pasquali M.
Published: March 2021

The field electron emission properties of carbon nanotube (CNT) films composed of densely packed and highly aligned CNTs were investigated. The CNT films were produced by a continuous film casting process and are spooled into long lengths with the CNTs aligned lengthwise in the film. The anisotropic nature of the CNT film morphology was confirmed by performing specific conductivity measurements in directions both parallel and perpendicular to the aligned CNT microstructure. Field emission experiments were performed on 5 and 10 mm wide films that were mechanically cut into small samples and then vertically mounted so that the emission occurred from the film edge. The films were mounted with the aligned CNT microstructure oriented either parallel or perpendicular to the direction of the applied electric field. The highest emission currents were produced by films mounted in the parallel alignment configuration. Additional experiments were performed on films that were folded, which eliminated surface irregularities at the film edge due to the cutting process. SEM imaging performed at the ridge of the folded film before and after field emission (FE) experiments showed that films mounted in the parallel alignment configuration had minimal surface damage after FE, while films mounted in the perpendicular alignment configuration showed substantial damage. The effective emission area and field enhancement factor were extracted from the FE data using the orthodox Fowler–Nordheim theory. Folded CNT film cathodes mounted in the parallel alignment configuration produced the highest emission currents, while demonstrating a larger emission area and lower field enhancement factor.
Controlling structure of materials derived from spinodally decomposing liquids
Authors: Arabjamaloei Rasoul , Shah Rajas Sudhir , Bryant Steven , Trifkovic Milana
Published: March 2021

Arresting morphological evolution of spinodally decomposing heterogeneous mixtures via the addition of colloidal particles has resulted in the discovery of new classes of bicontinuous materials, viz., bicontinuous interfacially jammed emulsion gels (bijels) and most recently bicontinuous intraphase jammed emulsion gels (bipjels). Here, we demonstrate how the extent of particle wettability and particle–particle interactions govern the ultimate structure formed. We present the multi-phase lattice Boltzmann method (LBM) integrated with a discrete particle model with two particle–particle collision models, the classic hard-sphere model and a new bonding collision model, to predict the final state of spinodally decomposing fluid mixtures containing solid particles. We show that the elastic collision model yields either the formation of emulsions or bijels, while only the bonding collision model on particles with preferential wettability for one phase can predict bipjels formation. In the case of bipjels, a delicate balance between the dynamics of evolving interface and the strength of particle–particle aggregates is required to restrict the interfacial motion. These results are consistent with experimental findings, suggesting that the presence of smaller particles with high particle–particle interactions can yield the formation of bipjels and consequent isolation of hierarchically porous materials.
Ferromagnetism in two-dimensional CrTe2 epitaxial films down to a few atomic layers
Authors: Sun Yizhe , Yan Pengfei , Ning Jiai , Zhang Xiaoqian , Zhao Yafei , Gao Qinwu , Kanagaraj Moorthi , Zhang Kunpeng , Li Jingjing , Lu Xianyang , Yan Yu , Li Yao , Xu Yongbing , He Liang
Published: March 2021

Two-dimensional (2D) van der Waals ferromagnetic materials have attracted intense attention due to their potential impact on both fundamental and applied research studies. Recently, a new 2D ferromagnet CrTe2, prepared by mechanical exfoliation or chemical vapor deposition, has gained interest due to its novel magnetic properties. In this work, high quality CrTe2 epitaxial thin films were prepared on GaAs (111)B substrates using solid source molecular beam epitaxy, with the thickness varying from 35 to 4 monolayers (MLs). The magnetic easy axis of all the films is oriented along the c-axis. A Curie temperature of 205 K is found in the 35 ML CrTe2 film, measured by the temperature-dependent anomalous Hall resistance (RAHE). Importantly, even when the film thickness decreases to 4 MLs, a robust out-of-plane ferromagnetism with a Curie temperature of 191 K has been demonstrated. This finding could pave the way for investigating the fundamental studies in 2D ferromagnetism and has great significance in device applications.
Selective area heteroepitaxy of low dislocation density antiphase boundary free GaAs microridges on flat-bottom (001) Si for integrated silicon photonics
Authors: Shi Bei , Song Bowen , Taylor Aidan A. , Brunelli Simone Suran , Klamkin Jonathan
Published: March 2021

Integrating III–V gain elements in the silicon photonics platform via selective area heteroepitaxy (SAH) would enable large-scale and low-cost photonic integrated circuits. Here, we demonstrate antiphase boundary (APB)-free gallium arsenide (GaAs) microridges selectively grown on flat-bottom (001) silicon (Si) inside a recess. This approach eliminates the need for etching the patterned Si to form trapezoid or v-groove shapes, often leveraged for eliminating APBs. A low surface dislocation density of 8.5 × 106 cm−2 was achieved for 15-μm-wide GaAs microridges, quantified by electron channeling contrast imaging. The avoidance of APBs is primarily due to their self-annihilation, influenced by the sufficiently low temperature GaAs nucleation and subsequent higher temperature buffer overgrowth. Dislocation filtering approaches, namely, thermal cycle annealing and strained-layer superlattices, have been applied to effectively reduce the dislocation density. SAH of GaAs on trapezoidal-shaped Si pockets is also reported to illustrate the differing growth conditions for GaAs on (001) and (111) Si microplanes.
A strategy for the design of magnetic memories in bubble-hosting magnets
Authors: Wu Yaodong , Kong Lingyao , Wang Yihao , Li Junbo , Xiong Yimin , Tang Jin
Published: March 2021

Magnetic memories based on localized magnetic objects with high performance are potentially applicable to future memory devices. In such devices, binary data bits “1” and “0” are suggested to be represented by skyrmions or skyrmion bubbles and ferromagnetic gaps, respectively. However, thermal fluctuations and interactions between skyrmions can induce interruptions in the stored data, and additional pinning sites must be fabricated. Here, we suggest that a pinning site-free magnetic memory, called skyrmion-bubble-based memory, can be realized in bubble-hosting magnets. In skyrmion-bubble-based memory, topologically trivial bubbles are used to replace ferromagnetic gaps to represent the other binary bits. A data bitstream can, thus, be represented by a skyrmion-bubble chain, and interactions between two neighbored magnetic objects can naturally suppress undesired motion of data bits. Further, a single skyrmion-bubble chain representing a data bitstream is realized experimentally in a typical bubble-hosting material, Fe3Sn2 nanostripe.
Signatures of light-induced nonadiabaticity in the field-dressed vibronic spectrum of formaldehyde
Authors: Fábri Csaba , Halász Gábor J. , Cederbaum Lorenz S. , Vibók Ágnes
Published: March 2021

Nonadiabatic coupling is absent between the electronic ground X and first excited (singlet) A states of formaldehyde. As laser fields can induce conical intersections between these two electronic states, formaldehyde is particularly suitable for investigating light-induced nonadiabaticity in a polyatomic molecule. The present work reports on the spectrum induced by light—the so-called field-dressed spectrum—probed by a weak laser pulse. A full-dimensional ab initio approach in the framework of Floquet-state representation is applied. The low-energy spectrum, which without the dressing field would correspond to an infrared vibrational spectrum in the X-state, and the high-energy spectrum, which without the dressing field would correspond to the X → A spectrum, are computed and analyzed. The spectra are shown to be highly sensitive to the frequency of the dressing light allowing one to isolate different nonadiabatic phenomena.
Incremental vibrational configuration interaction theory, iVCI: Implementation and benchmark calculations
Authors: Schröder Benjamin , Rauhut Guntram
Published: March 2021

The implementation of an algorithm for the determination of vibrational state energies based on a many-body expansion within the framework of configuration interaction theory is presented. An efficient evaluation of the increments within this approach is realized by an iterative configuration selection scheme. The new algorithm is characterized by low memory demands and an embarassingly parallel workload. The convergence of the expansion has been studied for a series of small molecules of increasing size, namely, formaldehyde, ketene, ethylene, and diborane. A threshold function has been employed to reduce the number of increments for high orders of the expansion. Benchmark calculations with respect to customary configuration-selective vibrational configuration interaction calculations are provided.
Source of two-dimensional electron gas in unintentionally doped AlGaN/GaN multichannel high-electron-mobility transistor heterostructures
Authors: Lingaparthi R. , Dharmarasu N. , Radhakrishnan K. , Ranjan A. , Seah Tian Long Alex , Huo Lili
Published: March 2021

Unintentionally doped (UID) AlGaN/GaN-based multichannel high electron mobility transistor (MC-HEMT) heterostructures have been demonstrated on the SiC substrate using plasma-assisted molecular beam epitaxy. The MC-HEMT heterostructure with a GaN channel thickness of 100 nm resulted in a cumulative two-dimensional electron gas (2DEG) concentration of 4.3 × 1013 cm−2 across six GaN channels. The sample showed sheet resistances of 170 Ω/sq. and 101 Ω/sq. at room temperature and 90 K, respectively. The source of 2DEG in the buried GaN channels of the heterostructure was investigated. The C–V measurements conducted on UID MC-HEMTs excluded the possibility of the valence band being the source of 2DEG and the consequent formation of two-dimensional hole gas at the buried GaN-channel/AlGaN-barrier interfaces. A comparison of the experimentally obtained 2DEG concentration with the simulated data suggests the presence of donor-like trap states, situated at 0.6 to 0.8 eV above the valence band at the buried GaN-channel/AlGaN-barrier interfaces, which act as the source of 2DEG in UID MC-HEMT heterostructures.
Striving for impartiality
Authors: Wilson Lauren , Walsh Dave
Published: March 2021

In the context of interpreter-assisted police interviews (IAPIs) it is essential for both police officers and
interpreters to maintain impartiality at all times. However, there are numerous obstacles on the way towards achieving this
fundamental goal. The present study examines whether and how the different conflicts in communication are constructed and
controlled within the different phases of police interviews, using a self-administered questionnaire that explores the perceptions
of police officers and interpreters. Three areas of conflict pertinent to impartiality were identified: role,
trust and emotion. The differing assumptions about the roles of police officers and
interpreters, and the respective differing expectations, appear to create barriers in the achievement of trust and in the working
relationship as a whole, which may well affect the aim of IAPIs (i.e. to gather reliable information) and alter the interview
outcomes. In addition, both police officers and interpreters have strong emotional experiences during IAPIs; however, neither
group appear to make conscious efforts to engage in coping strategies.
“We'll be Able to Take Care of Ourselves” – A Qualitative Study of Client Attitudes Toward Implementing Buprenorphine Treatment at Syringe Services Programs
Authors: Frost Taeko , Deutsch Sarah , Brown Shoshana , Lemien Ellen , Cunningham Chinazo O. , Fox Aaron D.
Published: March 2021

Background

Syringe services programs (SSPs) complement substance use disorder treatment in providing services that improve the health of people who use drugs (PWUD). Buprenorphine treatment is an effective underutilized opioid use disorder treatment. Regulations allow buprenorphine prescribing from office-based settings, potentially including SSPs although few studies have examined this approach. Our objective was to assess the attitudes among PWUD toward the potential introduction of buprenorphine treatment in an SSP.

Methods

In this qualitative study, we recruited 34 participants who were enrolled at a New York City-based SSP to participate in one of seven focus group sessions. The focus group facilitators prompted participants to share their thoughts in five domains: attitudes toward (1) medical clinics; (2) harm reduction in general; (3) SSP-based buprenorphine treatment; (4) potential challenges of SSP-based treatment; and (5) logistical considerations of an SSP-based buprenorphine treatment program. Four researchers analyzed focus group transcripts using thematic analysis.

Results

Of the 34 participants, most were white (68%), over the age of 40 years old (56%), and had previously tried buprenorphine (89%). Common themes were: 1) The SSP is a supportive community for people who use drugs; 2) Participants felt less stigmatized at the SSP than in general medical settings; 3) Offering buprenorphine treatment could change the SSP's culture; and 4) SSP participants receiving buprenorphine may be tempted to divert their medication. Participants offered suggestions for a slow intentional introduction of buprenorphine treatment at the SSP including structured appointments, training medical providers in harm reduction, and program eligibility criteria.

Conclusion

Overall, participants expressed enthusiasm for onsite buprenorphine treatment at SSPs. Research on SSP-based buprenorphine treatment should investigate standard buprenorphine treatment outcomes but also any effects on the program itself and medication diversion. Implementation should consider cultural and environmental aspects of the SSP and consult program staff and participants.
Eigen microstates and their evolutions in complex systems
Authors: Sun Yu , Hu Gaoke , Zhang Yongwen , Lu Bo , Lu Zhenghui , Fan Jingfang , Li Xiaoteng , Deng Qimin , Chen Xiaosong
Published: March 2021

Emergence refers to the existence or formation of collective behaviors in complex systems. Here, we develop a theoretical framework based on the eigen microstate theory to analyze the emerging phenomena and dynamic evolution of complex system. In this framework, the statistical ensemble composed of M microstates of a complex system with N agents is defined by the normalized N × M matrix
A
, whose columns represent microstates and order of row is consist with the time. The ensemble matrix
A
can be decomposed as

A
=

∑

I
=
1

r

σ

I

U

I

⨂

V

I

, where

r
=
min
(
N
,
M
)

, eigenvalue σ

I
behaves as the probability amplitude of the eigen microstate
U

I
so that

∑

I
=
1

r

σ

I

2

=
1

and
U

I
evolves following
V

I
. In a disorder complex system, there is no dominant eigenvalue and eigen microstate. When a probability amplitude σ

I
becomes finite in the thermodynamic limit, there is a condensation of the eigen microstate
U

I
in analogy to the Bose–Einstein condensation of Bose gases. This indicates the emergence of
U

I
and a phase transition in complex system. Our framework has been applied successfully to equilibrium three-dimensional Ising model, climate system and stock markets. We anticipate that our eigen microstate method can be used to study non-equilibrium complex systems with unknown order-parameters, such as phase transitions of collective motion and tipping points in climate systems and ecosystems.
A novel multifunctional electronic calibration kit integrated by MEMS SPDT switches*
Authors: Wang Shan-Shan , Wu Qian-Nan , Gao Yue-Sheng , Yu Jian-Gang , Cao Qian-Long , Han Lu-Lu , Li Meng-Wei
Published: March 2021

Design and simulation results of a novel multifunctional electronic calibration kit based on microelectromechanical system (MEMS) single-pole double-throw (SPDT) switches are presented in this paper. The short-open-load-through (SOLT) calibration states can be completed simultaneously by using the MEMS electronic calibration, and the electronic calibrator can be reused 106 times. The simulation results show that this novel electronic calibration can be used in a frequency range of 0.1 GHz–20 GHz, the return loss is less than 0.18 dB and 0.035 dB in short-circuit and open-circuit states, respectively, and the insertion loss in through (thru) state is less than 0.27 dB. On the other hand, the size of this novel calibration kit is only 6 mm × 2.8 mm × 0.8 mm. Our results demonstrate that the calibrator with integrated radio-frequency microelectromechanical system (RF MEMS) switches can not only provide reduced size, loss, and calibration cost compared with traditional calibration kit but also improves the calibration accuracy and efficiency. It has great potential applications in millimeter-wave measurement and testing technologies, such as device testing, vector network analyzers, and RF probe stations.
Accurate Deep Potential model for the Al–Cu–Mg alloy in the full concentration space*
Authors: Jiang Wanrun , Zhang Yuzhi , Zhang Linfeng , Wang Han
Published: March 2021

Combining first-principles accuracy and empirical-potential efficiency for the description of the potential energy surface (PES) is the philosopher’s stone for unraveling the nature of matter via atomistic simulation. This has been particularly challenging for multi-component alloy systems due to the complex and non-linear nature of the associated PES. In this work, we develop an accurate PES model for the Al–Cu–Mg system by employing deep potential (DP), a neural network based representation of the PES, and DP generator (DP-GEN), a concurrent-learning scheme that generates a compact set of ab initio data for training. The resulting DP model gives predictions consistent with first-principles calculations for various binary and ternary systems on their fundamental energetic and mechanical properties, including formation energy, equilibrium volume, equation of state, interstitial energy, vacancy and surface formation energy, as well as elastic moduli. Extensive benchmark shows that the DP model is ready and will be useful for atomistic modeling of the Al–Cu–Mg system within the full range of concentration.
C band microwave damage characteristics of pseudomorphic high electron mobility transistor*
Authors: Li Qi-Wei , Sun Jing , Li Fu-Xing , Chai Chang-Chun , Ding Jun , Fang Jin-Yong
Published: March 2021

The damage effect characteristics of GaAs pseudomorphic high electron mobility transistor (pHEMT) under the irradiation of C band high-power microwave (HPM) is investigated in this paper. Based on the theoretical analysis, the thermoelectric coupling model is established, and the key damage parameters of the device under typical pulse conditions are predicted, including the damage location, damage power, etc. By the injection effect test and device microanatomy analysis through using scanning electron microscope (SEM) and energy dispersive spectrometer (EDS), it is concluded that the gate metal in the first stage of the device is the vulnerable to HPM damage, especially the side below the gate near the source. The damage power in the injection test is about 40 dBm and in good agreement with the simulation result. This work has a certain reference value for microwave damage assessment of pHEMT.
Learning design for the natural resonance concept of the rope system with a “Gambo”
Authors: Kurniawan E , Aminah N S , Harjana
Published: March 2021

Gambo as a traditional stringed musical instrument from Mbojo tribe (NTB) is increasingly missing its existence among the younger generation. This instrument has never been used as a media for learning physics, even though it can show the phenomena of vibration, waves and sound. This paper aims to explain the learning design of contruction the concept of natural resonance using a gambo system and involving advanced spectrum applications of smartphone and evidence the effectiveness of its implementation based on student understanding about the concept and its responses. The learning activity is guided inquiry which involves 28 senior high school students of Kota Bima grade XI. Data was collected through document studies and concept understanding tests. The results of test were analyzed using descriptive statistics and using the normalized gain test, while the analysis of student responses to learning activities used a likert scale. Based on studies and research results, it was concluded that the learning of the natural resonance concept of the string system using Gambo has been well designed and can be implemented easily and effectively. Understanding of students’ concepts increases significantly, and gets a good response from students.