bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancing sound absorption for an acoustic metastructure with extended tubes at ultra-low frequency
Authors: Li Yingli , Lin Yimin , Peng Yong
Published: September 2022

A micro-perforated plate (MPP) as a typical acoustic absorber has ideal sound absorption performance at mid-frequency. A novel metastructure with a MPP and multiple sub-cavities (MPP-MSC) is proposed to broaden the sound absorption frequency range based on Helmholtz resonance, and its sound absorption performance is studied theoretically, numerically, and experimentally. Then, the genetic algorithm is adopted to extend the effective sound absorption band by 120 Hz and reduce the structure thickness to less than 61 mm, which is about 40% thinner than the existing structures. Additionally, a perforated plate with extended tubes (PPET) and porous sound absorptive material (PSAM) are introduced into the metastructure to enhance sound absorption performance in the ultra-low and mid-frequency range. Therefore, the composite sound absorber (PP-MPP-MSC) composed of PPET, PSAM, and MPP with superior sound absorption performance is proposed. Specifically, the effective acoustic absorption frequency of the structure can be broadened to 200–1800 Hz with a maximum thickness of 61 mm. It is worth noting that the design and fabrication of PP-MPP-MSC are relatively accessible, and effective sound absorption performance can be achieved in a certain frequency range, which presents the guiding role for current noise reduction applications.
Enhancement of electrohydrodynamic force with AC bias voltage in three-electrode dielectric barrier discharge plasma actuators
Authors: Sato Shintaro , Sakurai Mahoro , Ohnishi Naofumi
Published: September 2022

A novel dielectric barrier discharge (DBD) plasma-actuator module with an exposed electrode and two covered electrodes was developed to enhance electrohydrodynamic force generation based on the concept that it separates the ionization and acceleration processes. The conventional three-electrode configuration of the DBD plasma actuator suffers from unexpected spark discharge between the exposed electrodes, thereby failing to strengthen the electric field intensity for accelerating charged particles or generating a stable ionic wind. In this study, a third electrode was embedded in the dielectric layer to prevent spark discharge. Furthermore, an alternating current (AC) waveform was employed as the bias voltage, which was applied to the third electrode, instead of the direct current (DC) voltage used in a conventional DBD plasma actuator. Induced flow visualization using particle image velocimetry technique revealed that the DC bias voltage forms a weak ionic wind in the proposed DBD plasma actuator owing to the electric field screening effect, and the ionic wind periodically appears when the polarity of the voltage is reversed by applying an AC-bias voltage. The velocity of the ionic wind increases with increasing frequency and the AC bias voltage amplitude. Also, decreasing the distance between the second and third electrodes results in ionic wind enhancement. The results obtained in this study provide insights into the drastic improvement in the performance of DBD plasma actuators with the enhancement of the electric field intensity for charged particle acceleration.
Electric field measurements of DC-driven positive streamer coronas using the E-FISH method
Authors: Strobel Lee R. , Martell Benjamin C. , Morozov Anatoli , Dogariu Arthur , Guerra-Garcia Carmen
Published: September 2022

This paper reports on electric field measurements, using the electric field-induced second harmonic (E-FISH) method, sampling the spatial structure and temporal development of DC-driven positive streamer coronas in atmospheric-pressure air at relevant timescales to examine the self-pulsating behavior of the discharge. The discharge is triggered from a point-to-plate geometry and consists of transient coronas, which bridge the inter-electrode gap and pulsate at about 3 kHz, superimposed with a persisting glow corona. The measurements presented challenge the phenomenological explanation for the pulsations based on field recovery at the anode driven by the evacuation of positive ions by electric drift effects and hint at a propagating wave-like feature from the plate-cathode to the tip-anode.
Elimination of self-oscillation between three cascaded reflectors in an X-band triaxial klystron amplifier
Authors: Yang Fuxiang , Dang Fangchao , He Juntao , Ge Xingjun , Ju Jinchuan , Zhang Xiaoping
Published: September 2022

Self-oscillation of three cascaded reflectors easily occurs in a triaxial klystron amplifier (TKA) since the TEM mode leakage cannot be cut off by a coaxial waveguide. To solve this issue, we propose a non-uniform reflector to obtain an optimal external quality factor, which indicates its minimum TEM mode leakage. The self-oscillation of three non-uniform reflectors is then suppressed by selecting a specific drift tube length between them. Moreover, different eigenfrequencies are chosen for the three improved reflectors to enhance the tolerance of the drift tube length between them. With these methods, the self-oscillation of three cascaded reflectors can be successfully eliminated, and a TKA with high output efficiency is capable of achieving a long pulse output.
A new approach to electrically detected magnetic resonance: Spin-dependent transient spectroscopy
Authors: Myers Kenneth J. , Lenahan Patrick M. , Ashton James P. , Ryan Jason T.
Published: September 2022

Electrically detected magnetic resonance (EDMR) is arguably the most sensitive method available to study electrically active point defects in semiconductor devices. Most EDMR studies have utilized spin-dependent recombination current and, thus, require p–n junctions or a photoconductive structure. Some time ago, Chen and Lang proposed and demonstrated EDMR via spin-dependent deep level transient spectroscopy in metal–oxide–semiconductor capacitors. We report on a similar and significantly simpler technique: spin-dependent transient spectroscopy (SDTS). We show that the sensitivity of this technique is independent of the resonance field and frequency. Through capacitance–voltage analysis, combined with our SDTS results, this technique can (crudely) provide information about the density of states of defects with a broad distribution of energy levels. In addition, we show that SDTS can be readily adapted to near-zero-field magnetoresistance effect measurements.
Giant power density from BiFeO3-based ferroelectric ceramics by shock compression
Authors: Zhou Zhangyang , Gao Zhipeng , Xiong Zhengwei , Liu Gaomin , Zheng Ting , Shi Yuanjie , Xiao Mingzhu , Wu Jiagang , Fang Leiming , Han Tiexing , Liang Hao , He Hongliang
Published: September 2022

Ferroelectric pulsed-power sources with rapid response time and high output energy are widely applied in the defense industry and mining areas. As the core materials, ferroelectric materials with large remnant polarization and high electrical breakdown field should generate high power under compression. Currently, lead zirconate titanate 95/5 ferroelectric ceramics dominated in this area. Due to environmental damage and limited output power of lead-based materials, lead-free ferroelectrics are highly desirable. Here, the electrical response of 0.9BiFeO3-0.1BaTiO3 (BFO-BT) ferroelectric ceramics under shock-wave compression was reported, and a record-high power density of 4.21 × 108 W/kg was obtained, which was much higher than any existing lead-based ceramics and other available energy storage materials. By in situ high-pressure neutron diffraction, the mechanism of shock-induced depolarization of the BFO-BT ceramics was attributed to pressure-induced structural transformation, and the excellent performance was further elaborated by analyzing magnetic structure parameters under high pressures. This work provides a high-performance alternative to lead-based ferroelectrics and guidance for the further development of new materials.
Coherently strained (001) β-(AlxGa1−x)2O3 thin films on β-Ga2O3: Growth and compositional analysis
Authors: Mauze Akhil , Itoh Takeki , Zhang Yuewei , Deagueros Evelyn , Wu Feng , Speck James S.
Published: September 2022

In this work, we report on the growth of (001) β-(AlxGa1−x)2O3 films in molecular beam epitaxy via metal oxide-catalyzed epitaxy. Films with Al contents up to 15% were grown and the Al content was measured with atom probe tomography. A relationship between the Al content and the out-of-plane lattice parameter was derived for both (001) and (100) orientations. Transmission electron microscopy showed no evidence of extended defects in (001) β-(AlxGa1−x)2O3, and reciprocal space maps confirmed that β-(AlxGa1−x)2O3 films were coherently strained to (001) β-Ga2O3. Sn was also demonstrated to act as a surfactant for (001) β-(AlxGa1−x)2O3 growth, allowing for high-quality, uniform films with smooth morphologies.
High-pressure structural stability and bandgap engineering of layered tin disulfide
Authors: Shi Yuyang , Song Haipeng , Li Nan , Wu Xiang , Wang Kai , Wu Ye , Ye Gonglan , Huang Haijun
Published: September 2022

Two-dimensional layered metal dichalcogenides have attracted extensive attention because of their diverse physical properties and potential applications in electronics and optoelectronics. As an eco-friendly and earth abundant semiconductor, SnS2 displays limited optoelectronic applications due to its large and indirect bandgap. Pressure is a powerful tool to tune crystal structures and physical properties of materials. Here, we systematically investigate the structural stability and optical properties of 4H-SnS2 under high pressure. The crystal structure of 4H-SnS2 is stable up to 56 GPa without structural transition and layer sliding. Continuous lattice contraction is accompanied by gradual bandgap narrowing, which is reversible after releasing pressure. The continuous and reversible modulation of the crystal structure and bandgap on 4H-SnS2 suggest promising optoelectronic applications in the range of visible light based on two-dimensional layered metal dichalcogenides.
Characteristics of sprays produced by coaxial non-swirling and swirling air–water jets with high aerodynamic Weber numbers
Authors: Liang Yifan , Johansen Lars Christian , Linne Mark
Published: September 2022

This paper describes part of an experimental study on shear-based spray formation. A laminar liquid jet was ejected inside co-annular non-swirling and swirling air streams. The aerodynamic Weber numbers (WeA) and swirl numbers (S) of the flow cases ranged from 256 to 1426 and from 0 to 3.9, respectively. The aim of this paper is to investigate how S and WeA influence the breakup of a central laminar liquid jet within the fiber-type atomization regime. High-speed shadowgraphy was utilized to visualize the spray behavior, while phase Doppler interferometry was utilized to measure the droplet size and velocity distributions. It was found that as S increases, atomization is improved in a way that the droplets are blown outward from the central axis of the nozzle. However, for some specific flow cases, the median droplet diameter (D) does not appear to be related to S. These specific flow cases are discussed in this work. For S≥0.3, the upward motion of droplets located at the central axis of the nozzle was observed, which was caused by recirculating air flows. In addition, it was found that when S increases to 2.5, recirculating air flows start to penetrate to the water exit, which momentarily stops portions of the central laminar water jets from exiting. This pattern will be called turn-off behavior in this report. In order to study the underlying mechanisms behind the turn-off behavior, proper orthogonal decomposition was performed on the shadowgrams. It was found that the timing of turn-off initiation is random.
Ultra-broadband SnSe-based photothermoelectric detector for mid-infrared gas spectroscopy
Authors: Deng Wenjie , Wang Chongwu , Dai Mingjin , Wang Fakun , Han Jiayue , Sun Fangyuan , Wang Qi Jie , Zhang Yongzhe
Published: September 2022

Seebeck effect is one of the desirable pathways for developing advanced room-temperature (RT) broadband photothermoelectric (PTE) detectors, which are important for infrared spectroscopy applications. However, achieving high performance PTE detectors utilizing materials with high Seebeck coefficient remains a great challenge and further improvements are highly desired. Herein, we introduce a layered material SnSe with high Seebeck coefficient up to 507 ± 20 μV K−1 and further demonstrate an RT ultra-broadband PTE detector ranging from a visible region to a mid-infrared (MIR) region (0.532–13.2 μm). The detector yields a high responsivity of 0.47 V W−1 and a moderate response speed of 107 ms at an excitation wavelength of 8.1 μm at zero bias, which is comparable or higher than those parameters of the commercial products. Moreover, we have retrieved absorption fingerprints of molecular gases during MIR spectroscopy by using this detector owing to its wide response range, which illustrates great potential of this type of broadband high performance PTE detector toward advanced optoelectronics applications.
Resonant cold scattering of highly vibrationally excited D2 with Ne
Authors: Perreault William E. , Zhou Haowen , Mukherjee Nandini , Zare Richard N.
Published: September 2022

To accurately map weak D2–Ne long-range interactions, we have studied rotationally inelastic cold scattering of D2 prepared in the vibrationally excited (v = 4) and rotationally aligned (j = 2, m) quantum state within the moving frame of a supersonically expanded mixed molecular beam. In contrast to earlier high energy D2–Ne collision experiments, the (j = 2 → j′ = 0) cold scattering produced highly symmetric angular distributions that strongly suggest a resonant quasi-bound collision complex that lives long enough to make a few rotations. Our partial wave analysis indicates that the scattering dynamics is dominated by a single resonant l = 2 orbital, even in the presence of a broad temperature (0–5 K) distribution that allows incoming orbitals up to l = 5. The dominance of a single orbital suggests that the resonant complex stabilizes through the coupling of the internal (j = 2) and orbital (l = 2) angular momentum to produce a total angular momentum of J = 0 for the D2–Ne complex.
Phragmén–Lindelöf type alternative results for the solutions to generalized heat conduction equations
Authors: Li Yuanfei , Chen Xuejiao
Published: September 2022

This paper investigates the spatial behavior of the solutions of the generalized heat conduction equations on a semi-infinite cylinder by means of a first-order differential inequality. We consider three kinds of semi-infinite cylinders with boundary conditions of Dirichlet type. For each cylinder, we prove the Phragmén–Lindelöf alternative for the solutions. In the case of decay, we also present a method for obtaining explicit bounds for the total energy.
Speakers’ subjective evaluation of adversity
Authors: Su Danjie
Published: September 2022

Adversative passives like Mandarin Chinesebei-passives are known to convey adversity, but what “adversity” means specifically for speakers ofbei-in conversational discourse remains unknown. Whereas previous studies examine adversity within thebei-clause, this study uses the lens concept to investigate speakers’ subjective evaluations of the event attested by the larger context beyond thebei-clause. Using a subjectivity coding scheme and the discourse adjacent alternation method, I analyzed 4,203 values of event valence of 1,401bei-utterances and 65 alternations in spontaneous talk show conversations. Results show that: (1) The same event that a speaker evaluates as “adverse” usingbei- is sometimes evaluated as “non-adverse” using non-beistructures. (2) The samebei+verb phrase that previous studies may deem “adverse” can be evaluated as “adverse” or “positive” by actual speakers. (3) 84.5% (1,184/1,401) of the time,bei-passive in conversation expresses speakers’ evaluation that a causative event is adverse for the affectee, regardless of what reality is. (4) Adversity means undesirable, disadvantageous, morally or socially wrong, empathy-deserving, and/or sympathy-deserving for speakers ofbei-. The findings indicate that the adversity thatbei-conveys is not an objective description of reality but a subjective evaluation independent of reality–the Adversity lens. This study sheds light on subjectivity and specific manifestations of adversity in conversational discourse.
Have newborn hearing screening programs been affected by the COVID-19 pandemic?
Authors: Iran Pour Mobarakeh Zahra , Mehrbakhsh Fatemeh , Amiri Mehran , Amiri Marzieh
Published: September 2022

Introduction

Due to the vital importance of early diagnosis and intervention of congenital hearing loss, the aim of this study was to compare the rate of newborn hearing screening before and after the COVID-19 pandemic quarantine.

Materials and methods

In this study, the data related to 6144 newborns during two 18-month time periods before and after the onset of the COVID-19 pandemic quarantine, was analyzed.

Results

From all visited newborns, 3770 and 2374 referred to the centre before and after the COVID-19 pandemic quarantine, respectively. There were statistically significant differences in the results of screening and the referral rate of neonates before and after the pandemic (p = 0.00). The results showed that both the residents of urban and rural regions visited for newborn hearing screening less frequently after the onset of the pandemic, but no statistically significant difference was shown between the number of boys and girls before and after the pandemic (p = 0.72).

Conclusion

Our results help gain new insights regarding the impacts of disruptive events such as pandemics on the implementation of health screening programs. Boosting public knowledge by providing families with proper education appears to be helpful in preventing the negative effects of delayed implementation of health screening programs.
ER as master regulator of membrane trafficking and organelle function
Authors: Wenzel Eva Maria , Elfmark Liv Anker , Stenmark Harald , Raiborg Camilla
Published: September 2022

The endoplasmic reticulum (ER), which occupies a large portion of the cytoplasm, is the cell’s main site for the biosynthesis of lipids and carbohydrate conjugates, and it is essential for folding, assembly, and biosynthetic transport of secreted proteins and integral membrane proteins. The discovery of abundant membrane contact sites (MCSs) between the ER and other membrane compartments has revealed that, in addition to its biosynthetic and secretory functions, the ER plays key roles in the regulation of organelle dynamics and functions. In this review, we will discuss how the ER regulates endosomes, lysosomes, autophagosomes, mitochondria, peroxisomes, and the Golgi apparatus via MCSs. Such regulation occurs via lipid and Ca2+ transfer and also via control of in trans dephosphorylation reactions and organelle motility, positioning, fusion, and fission. The diverse controls of other organelles via MCSs manifest the ER as master regulator of organelle biology.
Conformational transitions of the Spindly adaptor underlie its interaction with Dynein and Dynactin
Authors: d’Amico Ennio A. , Ud Din Ahmad Misbha , Cmentowski Verena , Girbig Mathias , Müller Franziska , Wohlgemuth Sabine , Brockmeyer Andreas , Maffini Stefano , Janning Petra , Vetter Ingrid R. , Carter Andrew P. , Perrakis Anastassis , Musacchio Andrea
Published: September 2022

Cytoplasmic Dynein 1, or Dynein, is a microtubule minus end–directed motor. Dynein motility requires Dynactin and a family of activating adaptors that stabilize the Dynein–Dynactin complex and promote regulated interactions with cargo in space and time. How activating adaptors limit Dynein activation to specialized subcellular locales is unclear. Here, we reveal that Spindly, a mitotic Dynein adaptor at the kinetochore corona, exists natively in a closed conformation that occludes binding of Dynein–Dynactin to its CC1 box and Spindly motif. A structure-based analysis identified various mutations promoting an open conformation of Spindly that binds Dynein–Dynactin. A region of Spindly downstream from the Spindly motif and not required for cargo binding faces the CC1 box and stabilizes the intramolecular closed conformation. This region is also required for robust kinetochore localization of Spindly, suggesting that kinetochores promote Spindly activation to recruit Dynein. Thus, our work illustrates how specific Dynein activation at a defined cellular locale may require multiple factors.
Vortex flow, a couple important theorems, and an introduction to distributions
Authors: Arenas-Gullo A , Martínez-Manzano F , Fernández-Nieves A
Published: September 2022

We study vortex flow and perform a number of textbook calculations to highlight inconsistencies between results when using familiar, and widely important, mathematical theorems; these include Stokes’ theorem and a theorem that often enables interchanging field notions like irrotational and conservative, and their connection to scalar potentials and their associated exact differentials. The purpose is to use the familiar setting of a fluid vortex to go beyond conventional functional analysis and introduce students to the theory of distributions. After briefly doing this, we revisit vortex flow using a distributional approach to show how all prior inconsistencies disappear, emphasizing the significance of distributions in physics.
A K-nearest neighbor indoor fingerprint location method based on coarse positioning circular domain and the highest similarity threshold
Authors: Li Xiaonian , Dai Zhicheng , He Lamei
Published: September 2022

There are two problems with traditional indoor fingerprint location methods. First, irrelevant fingerprints in a fingerprint database interfere with the matching phase, which leads to poor positioning accuracy and stability of positioning results, and second, there is a large amount of computational overhead in the matching phase. Therefore, this paper proposes a K-nearest neighbor indoor fingerprint location method based on coarse positioning circular domain and the highest similarity threshold. In this method, a circular domain is formed in a coarse positioning process to narrow the positioning range. It solves the problem of the interference of irrelevant fingerprints. At the same time, a fault-tolerant mechanism is introduced to adjust the circular domain dynamically to ensure that the coarse positioning circular domain contains high similarity reference points and improve the fault tolerance of the coarse positioning. This method consists of offline and online phases. In the offline phase, the values of the received signal strength from Bluetooth low energy are preprocessed using a Gaussian filter to construct a fingerprint database. In the online phase, irrelevant fingerprints are filtered out by using the coarse positioning method. The filtered fingerprints are then matched with a testing point by the K-nearest neighbor algorithm, and the weighted centroids of the nearest reference points are solved. Finally, the coordinate of the testing point is obtained. The experimental results show that this method can effectively improve indoor positioning accuracy when compared with the traditional K-nearest neighbor. The average positioning error of the proposed method is 0.844 m.
A wearable shear force transducer based on color spectrum analysis
Authors: McGeehan Michael , Hahn Michael , Karipott Salil , Ong Keat Ghee
Published: September 2022

The need for miniaturized shear force sensors is expanding, particularly for biomedical applications. Examples include measuring interfacial shear stresses between a human and an external device (e.g. footwear or a prosthesis). However, there are considerable challenges in designing a shear sensor for these applications due to the need for a small package, low power requirements, and resistance to interference from motion artifact and electromagnetic fields. This paper presents the design, fabrication, and characterization sensor that measures two-axis shear force by detecting displacement between a color panel and a red, green, and blue light-sensing photodiode. The sensor response to applied displacements and forces was characterized under benchtop testing conditions. We also present the design of a prototype wireless version of the sensor for integration into footwear. The sensor exhibited strong agreement with gold standard measurements for two-axis shear displacements (R
2 > 0.99, RMSE ⩽ 5.0 µm) and forces (R
2 > 0.99, RMSE ⩽ 0.94 N). This performance, along with the sensor’s scalability, miniaturized form, and low power requirements make it well-suited a variety of biomedical applications.
Enhancing the stability of environmental resistance of alloyed CdZnSeS@ZnS quantum dots by doping Ti ions into shell layer
Authors: Fang Fan , Liu Haochen , Wen Zuoliang , Liu Chenxi , Xu Bing , Zhang Zhikuan , Wang Kai , Ertugrul Mehmet , Lei Wei , Sun Xiao Wei
Published: September 2022

Colloidal quantum dots (QDs) are promising luminescent materials for display and lighting, but their stability has long been an issue. Here, we designed a passivation strategy of doping Ti ions into the shell of alloyed CdZnSeS@ZnS QDs. The results showed that Ti ions were successfully doped into the ZnS shell and the stability of QDs was improved. In the aging test, the Ti ions doped QDs maintained 51.4% of the initial performance after 90 h of aging, while the pristine QDs decreased to less than 25% of the initial value. In addition, we discuss the reasons why Ti ions doping improves the stability of QDs. Ti ions are found to form Ti–S bonds in the ZnS shell, which has high binding energy and strong oxidation resistance. Most importantly, since there is no external physical insulating coating, the optimized QDs can also be directly used in electroluminescent devices, showing great potential in electroluminescence applications.
Analysis of the plasma meniscus in a hydrogen electronegative plasma
Authors: Miyamoto Kenji , Hayashi Katuya , Hoshino Kazuo , Hatayama Akiyoshi
Published: September 2022

The emitting surface of an ion beam (plasma meniscus) in the vicinity of the extraction aperture is theoretically investigated. In the present study, the electrons, H+ ions and volume produced H− ions are contained in the electronegative plasma. By solving the one-dimensional Poisson equation, an analytical formula is obtained from the balance between the current reaching a wall and the space charge limited current of negatively charged particles. The analytical formula indicates that the distance, d
eff, between the plasma meniscus and the extraction grid includes the ratio of masses of the negative ions and electrons, which is different from that for a plasma containing electrons and single positive ions, and depends on the ratio of the negative ion density to the electron density, α. With increase in the value of α, the distance d
eff becomes shorter, and thus the penetration of the electric field for negative ion extraction into the source plasma becomes smaller. This tendency is confirmed by using a three-dimensional particle-in-cell simulation from the results of the contour map of the electrostatic potential near the plasma grid and the location of the plasma meniscus. The reasons why the distance d
eff becomes shorter with increase in the value of α are considered to be the larger space charge effect of the negative ions compared with that of the electrons and the decrease in the plasma potential.
Role of temperature on linearity and analog/RF performance merits of a negative capacitance FinFET
Authors: Jaisawal Rajeewa Kumar , Rathore Sunil , Gandhi Navneet , Kondekar Pravin N , Bagga Navjeet
Published: September 2022

Temperature plays a decisive role in semiconductor device performance and reliability analysis. The effect is more severe in a negative capacitance (NC) transistor, as the temperature modulates the ferroelectric polarization, implicitly included by the Landau coefficients (α, β, γ) in Technology Computer Aided Design (TCAD) simulations. In this paper, through TCAD simulations, the role of varying ambient temperature is investigated in the linearity and analog/radio-frequency (RF) merits of NC-FinFET. The varying temperature modulates the carrier mobility, the semiconductor bandgap, and the Landau parameter (α). We analyzed the analog/RF and linearity metrics, such as total gate capacitance (C
gg), transconductance (g
m), unity gain cut-off frequency (f
T), the transconductance-frequency product, gain-bandwidth product, higher-order transconductance (g
m2 and g
m3), voltage intercept points, third-order power intercept and intermodulation points, and 1 dB CP using well-calibrated TCAD models. Our analysis reveals that these parameters are strongly dependent on temperature and the NC span (defined by using S-curve) shrinks with the rise in temperature. Finally, a source follower and three-stage ring oscillator are designed to test the frequency compatibility of the AC simulation for varying temperatures.
Fabrication and performance analysis of high-performance cylindrical ionic polymer-metal composite actuators with various diameters
Authors: Yin Guoxiao , Yu Min , Tong Xiaojie , Wu Yuwei , Tian Chengbo , Li Yang
Published: September 2022

Ionic polymer-metal composites (IPMCs) are electroactive polymer actuators that have been used as artificial muscles and have broad application prospects. In order to further improve the actuation performance of cylindrical IPMCs, Nafion rods with different diameters were prepared by extrusion process, and cylindrical IPMCs with high-quality Pt electrode layers were prepared by electroless plating in this study. The electrochemical properties and actuation performance of cylindrical IPMCs with various diameters were investigated. The tests show that the prepared cylindrical IPMCs have excellent electromechanical properties. As diameter increases, the blocking force and counter back-relaxation ability both increase significantly. Furthermore, the IPMCs with diameter of 3.0 mm under a DC voltage exhibits a superior blocking force (323.9 mN) and excellent power density (up to 139.41 W m−3). Moreover, the thick cylindrical IPMC can lift objects 400 times its weight, demonstrating exceptional load capacity, which shows great prospect of realizing artificial muscles.
Entanglement and quantum teleportation under superposed gravitational fields
Authors: Li Yue , Zhang Baocheng , You Li
Published: September 2022

The influence of gravitational field on entanglement of bipartite states is investigated based on the recent idea of superposition states of gravitational field. Different from earlier considerations, we study the case where the gravitational field cannot be separated unitarily from the bipartite system in the final stage of the interaction. When the different gravitational field states are orthogonal, entanglement cannot be generated for an initial product state. If the different gravitational field states are non-orthogonal, entanglement can be generated and the amount of generated entanglement depends on an overlap parameter between different gravitational field states. The influence of gravitational field on the transfer of the state through quantum teleportation is also studied, which might lead to an observable effect since the quantum teleportation can be performed using macroscopic object.
High efficiency of self-assembly between exfoliated MXene and layered-double-hydroxide nanosheets in exploring high-performance oxygen evolution reaction electrocatalysts
Authors: Jin Xiaoyan , Piao Huiyan , Sun Yiyang , Choy Jin-Ho , Hwang Seong-Ju
Published: September 2022

High-performance oxygen electrocatalysts have attracted tremendous research attention because of their crucial roles in diverse renewable energy technologies such as metal–oxygen batteries, fuel cells, and water electrolyzers. In this study, a novel lattice manipulation strategy for the exploration of highly active electrocatalysts was established via self-assembly between exfoliated MXene and layered double hydroxide (LDH) nanosheets (NSs). Electrostatically-driven self-assembly between cationic Co–Fe-LDH and anionic MXene NSs yielded intimately-coupled Co–Fe-LDH–MXene nanohybrids with porous stacking structures and significant interfacial charge transfer. The self-assembled Co–Fe-LDH–MXene nanohybrid delivered excellent electrocatalyst functionality with a lowered overpotential of 252 mV at 10 mA cm−2 that is much better than those of the precursor Co–Fe-LDH and MXene NSs. The outstanding electrocatalytic activity of the self-assembled Co–Fe-LDH–MXene nanohybrid highlights a high efficacy of the self-assembly methodology in exploring high-performance electrocatalysts. In situ surface enhanced Raman scattering analysis during electrocatalysis found that the enhanced redox activity of metal cations achieved by intimate electronic coupling with ultrathin conductive MXene NSs mainly contributes to the improved performance of the Co–Fe-LDH–MXene nanohybrids for oxygen evolution reaction.
Influence of Mo+2 ion concentration on crystallization, microstructure, crystal imperfection and morphology of WO3 sprayed thin films
Authors: Al-Shomar S M , Akl Alaa Ahmed , Mansour Dorsaf , Hedhili Fekhra , Aslam Affia , Shaaban Esam R , Mahmoud Safwat A
Published: September 2022

Compositional dependence of microstructure and morphological properties of MoxW1−xO3 (0.2 ≥ x ≥ 0.0 at. %) thin films was studied. MoWO3 films were deposited by chemical spray pyrolysis technique on pre-heated glass substrates at 400 °C and the sedimentation rate was kept constant at 70 ml min−1 with the deposition time fixed at 10 min to keep the film thickness constant at about 650 ± 5 nm. The prepared thin films were studied using x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and energy dispersive x-ray analysis (EDAX) techniques. The nature of the as-deposited films displayed by XRD showed beyond a reasonable doubt that they are amorphous. After thermal annealing at 500 °C for 2 h, all samples will be transferred to a polycrystalline having a triclinic structure. The microstructural parameters of the pure and doped samples were measured, using different methods and a comparison between them to determine the accuracy percentage of the measurement of these methods. The results also showed that the average crystallite size of the films decreased from 24 to 12 nm, on the contrary the internal microstrain increased from 23 × 10−3 to 30 × 10−3 with the addition of Mo element in WO3. Field emission scanning electron microscopy (FE-SEM) analysis also revealed that Mo dopant caused significant changes in the surface morphology of the films as well as an increase in particle size with increasing molybdenum concentration. The EDX results exhibited that the percentages of the isotropic elements MoxW1−xO3 agree well with those determined by atomic weight. In general, the results obtained in this study confirm that MoxW1−xO3 with these properties, is suitable for photovoltaic and optoelectronic applications.
X-ray vision of Cu(In,Ga)Se2: from the Ga/In ratio to solar-cell performance
Authors: Ossig C , Pyrlik N , Carron R , Fevola G , Patjens S , Strelow C , Flügge J , Kolditz A , Siebels J , Garrevoet J , Spiers K , Seyrich M , Brückner D , Hagemann J , Seiboth F , Schropp A , Falkenberg G , Mews A , Schroer C G , Kipp T , Stuckelberger M E
Published: September 2022

Cost efficiency and defect passivation are the two major challenges that thin-film solar cells have to overcome for economic competitiveness. For Cu(In,Ga)Se

2

solar cells, the first is addressed by an increase of the Ga/In ratio, which widens the bandgap favorably for tandem applications and reduces the requirement of costly, rare In. The second is addressed by heavy alkali post-deposition treatments. However, the maximum device efficiency is typically achieved with a comparably low Ga/In ratio, which is in contrast to the economic interest of a higher Ga/In ratio and makes it paramount to identify, understand and mitigate the sources of local underperformance in Ga-rich cells. In this work, we investigate a series of Cu(In,Ga)Se

2

cells with varying Ga/In concentration in the absorber, using multi-modal scanning x-ray microscopy. In particular, we analyze differences in chemical composition and electrical performance on the nanoscale, with a focus on the effect of Rb. We find that In-rich cells show, along with a greater overall performance, a more homogeneous distribution of the nanoscale performance compared to the Ga-rich cells. Our analysis on Rb suggests that this effect is due to a more effective passivation of structural defects in the absorbers, i.e. voids and grain boundaries. These results shine light on the causes of the superiority of Ga-poor/In-rich absorbers and substantiate the trend to higher defect density for Ga-rich absorbers.
Taper-tip double-layer grating antenna based on SiN-on-SOI with large scale-scanning range for LiDAR
Authors: Cheng Liwen , Zhang Jiarong , Chen Zhipeng , Liu Pengfei , Chen Haitao
Published: September 2022

In this article, with the objective of reducing the emission loss, enhancing the emission directionality and scale-scanning range, without increasing the complexity of the LIDAR system, a CMOS-compatible silicon nitride taper-tip double-layer auxiliary grating antenna is proposed and investigated systematically. Compared to conventional double layer grating, the directionality exceeds 72% for wavelengths from 1450 nm to 1600 nm, with a maximum directionality of 97.5% at 1550 nm. Therefore, the far-field divergence angle of 0.0081° × 0.03° and a large field of view of 108.45° × 23.43° can be achieved when the antenna aperture is 1.6 cm × 2.5 cm. These improvements come mainly from the increasing unidirectional emission performance of the phased array by adjusting the key structural parameters of the inverted taper-tip double-layer structure.
ANGPTL2 aggravates doxorubicin-induced cardiotoxicity via inhibiting DUSP1 pathway
Authors: Liu Cheng , Chen Qiuling , Liu Huadong
Published: September 2022

Angiopoietin-like protein 2 (ANGPTL2) plays versatile roles in various cardiovascular diseases. Its connection to doxorubicin (DOX)-related cardiomyopathy, however, remains elusive. To determine the role of ANGPTL2, an adeno-associated viral vector was used to overexpress ANGPTL2 in the murine heart 4 weeks before DOX treatment (15 mg/kg). Moreover, mice were injected with adenoviral vectors to knock down ANGPTL2 in the myocardium. Echocardiography and hemodynamics were used to determine the cardiac function. The effect of ANGPTL2 and its downstream target were elucidated by applying molecular and biochemical strategies. We found that ANGPTL2 expression was significantly increased in response to DOX stimulation. Moreover, cardiac-specific ANGPTL2 overexpression exacerbated DOX-related cardiac dysfunction, myocardial apoptosis, and oxidative stress. Mechanistically, ANGPTL2 aggravated DOX-induced cardiac injury via inhibiting the dual specificity phosphatase 1 (DUSP1) pathway and DUSP1 overexpression significantly impeded DOX-induced cardiomyopathy in ANGPTL2-overexpressed mice. Altogether, ANGPTL2 aggravated DOX-related cardiac injury by suppressing the DUSP1 pathway.
The sequence context in poly-alanine regions: structure, function and conservation
Authors: Mier Pablo , Elena-Real Carlos A , Cortés Juan , Bernadó Pau , Andrade-Navarro Miguel A
Published: September 2022

Motivation

Poly-alanine (polyA) regions are protein stretches mostly composed of alanines. Despite their abundance in eukaryotic proteomes and their association to nine inherited human diseases, the structural and functional roles exerted by polyA stretches remain poorly understood. In this work we study how the amino acid context in which polyA regions are settled in proteins influences their structure and function.

Results

We identified glycine and proline as the most abundant amino acids within polyA and in the flanking regions of polyA tracts, in human proteins as well as in 17 additional eukaryotic species. Our analyses indicate that the non-structuring nature of these two amino acids influences the α-helical conformations predicted for polyA, suggesting a relevant role in reducing the inherent aggregation propensity of long polyA. Then, we show how polyA position in protein N-termini relates with their function as transit peptides. PolyA placed just after the initial methionine is often predicted as part of mitochondrial transit peptides, whereas when placed in downstream positions, polyA are part of signal peptides. A few examples from known structures suggest that short polyA can emerge by alanine substitutions in α-helices; but evolution by insertion is observed for longer polyA. Our results showcase the importance of studying the sequence context of homorepeats as a mechanism to shape their structure–function relationships.

Availability and implementation

The datasets used and/or analyzed during the current study are available from the corresponding author onreasonable request.

Supplementary information

Supplementary data are available at Bioinformatics online.
Accurate machine learning prediction of sexual orientation based on brain morphology and intrinsic functional connectivity
Authors: Clemens Benjamin , Lefort-Besnard Jeremy , Ritter Christoph , Smith Elke , Votinov Mikhail , Derntl Birgit , Habel Ute , Bzdok Danilo
Published: September 2022

Background

Sexual orientation in humans represents a multilevel construct that is grounded in both neurobiological and environmental factors.

Objective

Here, we bring to bear a machine learning approach to predict sexual orientation from gray matter volumes (GMVs) or resting-state functional connectivity (RSFC) in a cohort of 45 heterosexual and 41 homosexual participants.

Methods

 In both brain assessments, we used penalized logistic regression models and nonparametric permutation.

Results

 We found an average accuracy of 62% (±6.72) for predicting sexual orientation based on GMV and an average predictive accuracy of 92% (±9.89) using RSFC. Regions in the precentral gyrus, precuneus and the prefrontal cortex were significantly informative for distinguishing heterosexual from homosexual participants in both the GMV and RSFC settings.

Conclusions

 These results indicate that, aside from self-reports, RSFC offers neurobiological information valuable for highly accurate prediction of sexual orientation. We demonstrate for the first time that sexual orientation is reflected in specific patterns of RSFC, which enable personalized, brain-based predictions of this highly complex human trait. While these results are preliminary, our neurobiologically based prediction framework illustrates the great value and potential of RSFC for revealing biologically meaningful and generalizable predictive patterns in the human brain.
Abnormal information interaction in multilayer directed network based on cross-frequency integration of mild cognitive impairment and Alzheimer’s disease
Authors: Xue Jiayue , Yao Rong , Cui Xiaohong , Wang Bin , Wei Jing , Wu Xubin , Sun Jie , Yang Yanli , Xiang Jie , Liu Yi
Published: September 2022

Mild cognitive impairment (MCI) and Alzheimer’s disease (AD) have been reported to result in abnormal cross-frequency integration. However, previous studies have failed to consider specific abnormalities in receiving and outputting information among frequency bands during integration. Here, we investigated heterogeneity in receiving and outputting information during cross-frequency integration in patients. The results showed that during cross-frequency integration, information interaction first increased and then decreased, manifesting in the heterogeneous distribution of inter-frequency nodes for receiving information. A possible explanation was that due to damage to some inter-frequency hub nodes, intra-frequency nodes gradually became new inter-frequency nodes, whereas original inter-frequency nodes gradually became new inter-frequency hub nodes. Notably, damage to the brain regions that receive information between layers was often accompanied by a strengthened ability to output information and the emergence of hub nodes for outputting information. Moreover, an important compensatory mechanism assisted in the reception of information in the cingulo-opercular and auditory networks and in the outputting of information in the visual network. This study revealed specific abnormalities in information interaction and compensatory mechanism during cross-frequency integration, providing important evidence for understanding cross-frequency integration in patients with MCI and AD.
Haros graphs: an exotic representation of real numbers
Authors: Calero-Sanz Jorge , Luque Bartolo , Lacasa Lucas
Published: September 2022

This article introduces Haros graphs, a construction which provides a graph-theoretical representation of real numbers in the unit interval reached via paths in the Farey binary tree. We show how the topological structure of Haros graphs yields a natural classification of the real numbers into a hierarchy of families. To unveil such classification, we introduce an entropic functional on these graphs and show that it can be expressed, thanks to its fractal nature, in terms of a generalized de Rham curve. We show that this entropy reaches a global maximum at the reciprocal of the Golden number and otherwise displays a rich hierarchy of local maxima and minima that relate to specific families of irrationals (noble numbers) and rationals, overall providing an exotic classification and representation of the reals numbers according to entropic principles. We close the article with a number of conjectures and outline a research programme on Haros graphs.
Transjugular closure of a residual septal device defect: a case report
Authors: Hernandez Felipe Hernandez , Linares Vicente Jose A , Muñoz David Ibañez , Ruiz Arroyo Jose R
Published: September 2022

Background

Severe residual shunts after percutaneous closure of atrial septal defects are unusual. These patients are usually considered candidates for surgery.

Case summary

We describe the transjugular closure of a residual atrial septal defect with significant left-to-right shunt due to a malpositioned large atrial septal device in a symptomatic 74-year-old female. Transjugular access was chosen first due to the unfavourable position of the device for delivery of a new one from the femoral approach. An overlapping Figulla® Flex II 27/30 mm PFO device was successfully implanted with the guidance of 3D-transoesophageal echocardiography.

Discussion

This case demonstrates the safety and feasibility of transjugular access as an alternative to femoral or transhepatic approaches in patients with difficult atrial septal anatomies, who are usually referred for surgery.