bluuebunny/crossref_metadata_2025_split huggingface dataset:
ReflectSim: an open-source software for teaching optical light reflection of nanostructured materials
Authors: Keene Clayton , Robertson Mark , Sarkar Gautam , King Jessica , Qiang Zhe 
Published: February 2022

Abstract
Leveraging computational resources for modern physics education has become increasingly prevalent, especially catalyzed by the COVID-19 pandemic when distance learning is widely implemented. Herein, we report an open-source software for students and instructors to on-demand simulate optical reflection behaviors of one-dimensional photonic crystals (1D-PCs), a model system for understanding light–matter interactions relevant to materials science and optical physics. Specifically, our MATLAB application, ReflectSim, employs an adapted transfer matrix method simulation and can account for the effects of several critical material design parameters, including interfacial roughness and layer geometry, to determine the reflectance spectrum of user-defined 1D-PCs. By packing our codes into a graphical user interface, this software is simple to use and bypass the requirement of any coding experiences from users, which can be widely used as an education tool in high school/undergraduate classrooms and K-12 outreach activities. We believe that ReflectSim provides great potential for assisting students in understanding optical phenomenon in nanostructured layered materials and relevant scientific concepts through enabling more engaging learning experiences.
Improvement on the uniformity of deep reactive ion etch for electrically isolated silicon-based substrates
Authors: Hu Xiao , Zhen Zhihan , Sun Guotao , Wang Qingkang , Huang Qiyu 
Published: February 2022

Abstract
Substrate-free micro-electro-mechanical systems (MEMS) devices are becoming the hotspots for microsystems. The fabrication of substrate-free MEMS devices usually involves the release of backside silicon by the inductively coupled plasma deep reactive ion etch (ICP-DRIE) process. However, when using DRIE to etch electrically isolated samples, significant non-uniformity in the etch profile were often observed. Compared to grounded silicon samples, the electrically isolated counterparts after DRIE showed a faster etch rate at the edge and a slower one in the center. This phenomenon is believed to be caused by the interaction between the deflection of charge-bearing ions entering the aperture region and the accumulated charges on the sidewall during DRIE. Simulation results with ICP showed that the electric field and ion distribution can be affected in electrically isolated substrates. After the isolated samples were electrically grounded, the charge accumulation on the sidewall was reduced and 12% etch uniformity was obtained. This technique helps in the fabrication of substrate-free MEMS devices.
Amplitude-phase modulation metasurface hologram with inverse angular spectrum diffraction theory
Authors: Su Deer , Wang Xinwei , Shang Guanyu , Ding Xumin , Burokur Shah Nawaz , Liu Jian , Li Haoyu 
Published: February 2022

Abstract
Designed metasurfaces, composed of a two-dimensional array of meta-atoms, provide an alternative approach to achieving efficient electromagnetic wave manipulation. Metasurface holography is an emerging and promising imaging technology, with improved image quality and spatial resolution compared to traditional holography. Many devices are fabricated only by coding specific phase responses of the designed metasurfaces. However, the modulation of both the amplitude and phase responses of electromagnetic waves can significantly improve the quality of the holographic image. In this paper, we employ bi-layered split rings as meta-atoms, which can fully control the transmission amplitude and phase independently. Furthermore, we present an algorithm based on the inverse angular spectrum diffraction theory to obtain the amplitude and phase information for the shape and arrangement of the meta-atoms. The proof-of-concept experiments in the microwave regime demonstrate that the inverse angular spectrum diffraction theory shows better image quality than the conventional Gerchberg-Saxton algorithm, especially when the number of meta-atoms is the same or even slightly fewer. The proposed approach provides an innovative and effective method for hologram design and expands the route to versatile applications related to holographic technologies.
Nanomechanical design strategy for single-mode optomechanical measurement
Authors: La Gala Giada , P Mathew John , Neveu Pascal , Verhagen Ewold 
Published: February 2022

Abstract
The motion of a mechanical resonator is intrinsically decomposed over a collection of normal modes of vibration. When the resonator is used as a sensor, its multimode nature often deteriorates or limits its performance and sensitivity. This challenge is frequently encountered in state-of-the-art optomechanical sensing platforms. We present a mechanical design strategy that ensures that optomechanical measurements can retrieve information on a single mechanical degree of freedom, and implement it in a sliced photonic crystal nanobeam resonator. A spectral design approach is used to make mechanical symmetries robust against practical disorder. The effectiveness of the method is evaluated by deriving a relevant figure of merit for continuous and pulsed measurement application scenarios. The method can be employed in any mechanical design that presents unwanted spurious mechanical modes. In the nanobeam platform, we experimentally show an increase of the signal to noise ratio of the mode of interest over the first spurious mode by four orders of magnitudes.
Dielectric loading method for doubly resonant enhancement of third-harmonic generation from complementary split-ring resonators
Authors: Chen Hao , Qin Zhaofu , Hu Taozheng , Chen Zhuo , Zhan Peng , Wang Zhenlin 
Published: February 2022

Abstract
Nonlinear optical response could be greatly enhanced when metasurfaces support plasmonic resonances at both fundamental and harmonic wavelengths. However, it is still challenging to fulfill the doubly resonant condition. Here, we propose a dielectric-loading method, which simply coats a conformal thin dielectric layer onto the plasmonic metasurfaces, to introduce an additional degree of freedom and make the doubly resonant condition easily fulfilled. We demonstrate that by simultaneously tuning the thickness of the coated dielectric layer and the geometrical parameters of the gold complementary split-ring resonators (CSRRs), the doubly resonant enhancement of third harmonic generation (THG) could be achieved for any given fundamental wavelengths. We also experimentally verify this concept and show that the THG intensity in the dielectric-loaded CSRRs under the doubly resonant condition could be further increased about 3 times as compared with the case of the conventional CSRRs.
Laser-assisted synthesis of Au aerogel with high-index facets for ethanol oxidation
Authors: Zhu Jiayin , Zhang Ran , Zhu Liye , Liu Xuan , Zhu Tiying , Guo Ziang , Zhao Yan 
Published: February 2022

Abstract
Gold (Au) can be used as an ideal metal electrocatalyst for ethanol and glucose oxidation reactions due to its high performance-to-cost ratio. In this paper, the Au aerogel with high-index facets was synthesized by using the laser ablation in liquid technology, which can improve the electrocatalytic activity of Au. The as-prepared Au aerogel showed excellent mass activity and specific activity toward ethanol oxidation reaction, which are 4.6 times and 2.1 times higher than Au/C, respectively. The 3D porous nature and rich defect of the Au aerogel provide more active sites. In addition, the high-index facets with under-coordinated atoms enhance the adsorption of ethanol and glucose molecules, thus improving the intrinsic catalytic activity of Au aerogel. The effect of high-index facets has also been investigated by density functional theory calculations. Furthermore, the Au aerogels also show good electrocatalytic activity and stability toward glucose oxidation reaction. These results are conducive to promote the practical application of Au in electrocatalysis.
Computer-aided detection of pulmonary nodules based on convolutional neural networks: a review
Authors: Min Yuqin , Hu Liangyun , Wei Long , Nie Shengdong 
Published: February 2022

Abstract
Computer-aided detection (CADe) technology has been proven to increase the detection rate of pulmonary nodules that has important clinical significance for the early diagnosis of lung cancer. In this study, we systematically review the latest techniques in pulmonary nodule CADe based on deep learning models with convolutional neural networks in computed tomography images. First, the brief descriptions and popular architecture of convolutional neural networks are introduced. Second, several common public databases and evaluation metrics are briefly described. Third, state-of-the-art approaches with excellent performances are selected. Subsequently, we combine the clinical diagnostic process and the traditional four steps of pulmonary nodule CADe into two stages, namely, data preprocessing and image analysis. Further, the major optimizations of deep learning models and algorithms are highlighted according to the progressive evaluation effect of each method, and some clinical evidence is added. Finally, various methods are summarized and compared. The innovative or valuable contributions of each method are expected to guide future research directions. The analyzed results show that deep learning-based methods significantly transformed the detection of pulmonary nodules, and the design of these methods can be inspired by clinical imaging diagnostic procedures. Moreover, focusing on the image analysis stage will result in improved returns. In particular, optimal results can be achieved by optimizing the steps of candidate nodule generation and false positive reduction. End-to-end methods, with greater operating speeds and lower computational consumptions, are superior to other methods in CADe of pulmonary nodules.
Enhanced plasma generation in capacitively coupled plasma using a parallel inductor
Authors: Lim Yeong-Min , He You , Lee Jaewon , Kim Ju-Ho , Kim Kyung-Hyun , Chung Chin-Wook 
Published: February 2022

Abstract
Plasma generation efficiency in a capacitively coupled plasma (CCP) at high densities or high conductivity tends to be lower due to low plasma resistance. An inductor is installed to a powered electrode in parallel to improve plasma generation efficiency at higher density in the CCP. To reduce the power loss in a system, a parallel resonance is used between the capacitance of the CCP and the inductance of the parallel inductor. When parallel resonance occurs, the impedance of the chamber, including the plasma, increases. Therefore, the current flowing in the system is expected to decrease. At the resonance, the current in the system significantly decreases, and the voltages and currents at the powered electrode significantly increase. This phenomenon indicates that the system power loss is decreased, and the power absorbed by the plasma is increased. As a result, the ion density and the voltage at the powered electrode are increased up to 66% and 25% at the parallel resonance condition, respectively. To understand these increases, a circuit model for the plasma and the parallel inductor is suggested which shows good agreement with the experimental results. This method can be applied to the CCP for improving plasma generation.
Charged particle kinetics and gas heating in CO2 microwave plasma contraction: comparisons of simulations and experiments
Authors: Vialetto L , van de Steeg A W , Viegas P , Longo S , van Rooij G J , van de Sanden M C M , van Dijk J , Diomede P 
Published: February 2022

Abstract
This work investigates kinetics and transport of CO2 microwave plasmas through simulation results from a 1D radial fluid model and experiments. Simulation results are validated against spatially resolved measurements of neutral species mole fractions, gas temperature, electron number density and temperature obtained by means of Thomson and Raman scattering diagnostics, yielding good agreement. As such, the model is used to complement experiments and assess the main chemical reactions, mass and energy transport in diffuse and contracted plasma regimes. From model results, it is found that, as pressure is raised, the inhomogeneous gas heating induces significant gradients in neutral and charged species mole fractions profiles. Moreover, the transition from diffuse to contracted plasma is accompanied by a change in the dominant charged species, which favours electron–ion recombination over dissociative attachment. Associative ionization rates increase in the plasma core from diffuse to contracted regime. These processes contribute to the increase in the peak electron number density with pressure, that determines radial plasma contraction.
Reheating in models with
non-minimal coupling
in metric and Palatini formalisms
Authors: Cheong Dhong Yeon , Lee Sung Mook , Park Seong Chan 
Published: February 2022

Abstract
We study reheating of inflationary models with general non-minimal coupling K(ϕ)R with K(ϕ) ∼ √(V(ϕ)) where R is the Ricci scalar and R is the inflaton potential. In particular, when we take the monomial potential K(ϕ) ∝ ϕ
m
with m∈ℤ+, we provide general analytic expressions for cosmological observables. We consider a wide range of non-minimal coupling ξ∈[0,∞) in metric and Palatini formalisms and derive the predictions for cosmological observables and the reheating temperature taking a general equation of state parameter w
reh.
Amplification of primordial perturbations from the rise or fall of the inflaton
Authors: Inomata Keisuke , McDonough Evan , Hu Wayne 
Published: February 2022

Abstract
The next generation of cosmic microwave background, gravitational wave, and large scale structure, experiments will provide an unprecedented opportunity to probe the primordial power spectrum on small scales. An exciting possibility for what lurks on small scales is a sharp rise in the primordial power spectrum: this can lead to the formation of primordial black holes, providing a dark matter candidate or the black holes observed by the LIGO-Virgo collaboration. In this work we develop a mechanism for the amplification of the small-scale primordial power spectrum, in the context of single-field inflation with a step-like feature in the inflaton potential.
Specifically, we consider both the upward and the downward step in the potential. We also discuss the possibility of the strong coupling between perturbations because the rapid changes of the potential derivatives with the time-dependent field value, caused by the step-like feature, could make the coupling stronger. As a result, we find that the perturbations can remain weakly coupled yet sufficiently enhanced if the step realizes the rapid changes of the potential derivatives in some fraction of an e-fold, 𝒪(𝒫ℛ
1/2) ≲ ΔN < 1, where 𝒫ℛ is the power spectrum of the curvature perturbation at that time.
We also discuss the PBH formation rate from the inflaton trapping at the local minimum, which can occur in the potential with an upward step.
Soliton boson stars, Q-balls and the causal Buchdahl bound
Authors: Bošković Mateja , Barausse Enrico 
Published: February 2022

AbstractSelf-gravitating non-topological solitons whose potential admits multiple vacua are promising candidates for exotic compact objects. Such objects can arise in several extensions of the Standard Model and could be produced in the early Universe. In this work, we focus on objects made from complex scalars (gravitating Q-balls/soliton boson stars), deriving analytic solutions in spherical symmetry and comparing them with fully numerical ones. In the high-compactness limit we find that these objects present an effectively linear equation of state, thus saturating the Buchdahl limit with the causality constraint. Far from that limit, these objects behave either as flat space-time Q-balls or (in the low-compactness limit) as mini boson stars stabilized by quantum pressure. We establish the robustness of this picture by analyzing a variety of potentials (including cosine, quartic and sextic ones).
Astrophysical constraints
on compact objects in 4D Einstein-Gauss-Bonnet gravity
Authors: Charmousis C. , Lehébel A. , Smyrniotis E. , Stergioulas N. 
Published: February 2022

Abstract
We study the properties of compact objects in a particular 4D Horndeski theory originating from higher dimensional Einstein-Gauss-Bonnet gravity. Remarkably, an exact vacuum solution is known. This compact object differs from general relativity mostly in the strong field regime. We discuss some properties of black holes in this framework and investigate in detail the properties of neutron stars, both static and in slow rotation. We find that for relatively modest deviations from general relativity, the secondary object in GW190814 is compatible with being a slowly-rotating neutron star, without resorting to very stiff or exotic equations of state. Remarkably, the equilibrium sequence of neutron stars matches asymptotically to the black hole limit, completetly closing the mass gap between neutron stars and black holes of same radius, although the stability of equilibrium solutions has yet to be determined. As a consequence, there exists a universal endpoint for the neutron star sequence, independent of the equation of state. In light of our results and of current observational constraints, we discuss specific constraints on the coupling constant that parametrizes deviations from general relativity in this theory.
Parts of Speech Tagging: A Setswana Relative
Authors: Malema Gabofetswe , Ishmael Ontiretse 
Published: February 2022

Abstract
Setswana qualificatives consists of multiple words. This makes part of speech tagging a challenging task especially for the relative part of speech. The Setswana relative has a wide variety of structure in terms of number of words, form, tense, and negation. A few studies have looked at part of speech tagging for Setswana complex parts of speech including the relative. However, these studies did not explore in detail all the different forms of a relative. In this study, we investigate the different forms of a Setswana relative and convert them into a general pattern. The relative patterns are stored in a trie data structure which is used to detect relative’s parts of speech in a given Setswana sentence. Tests show that most of the relative forms are consistent giving a performance rate of 78% for the test data. The direct relative structure gives a higher performance rate as its structure is simpler and less ambiguous compared to the indirect relative structure.
Recent Advances in Representation Learning for Electronic Health Records: A Systematic Review
Authors: Liu Xiaocong , Wang Huazhen , He Ting , Liao Yongxin , Jian Chen 
Published: February 2022

Abstract
Representation Learning (RL) aims to convert data into low-dimensional and dense real-valued vectors, so as to realize reasoning in vector space. RL is one of the important research contents in the analysis of health data. This paper systematically reviews the latest research on Electronic Health Records (EHR) RL. We searched the Web of Science, Google Scholar, and Association for Computing Machinery Digital Library for papers involving EHR RL. On the basis of literature review, we propose a new taxonomy to categorize the state-of-the-art EHR RL methods into three categories: statistics learning-based RL methods, knowledge RL methods and graph RL methods. We analyze and summarize their characteristics according to the input data form and underlying learning mechanisms. In addition, we provide evaluation strategies to verify the quality of EHR representations from both intrinsic and extrinsic perspectives. Finally, we put forward three promising research directions to promote future research. Overall, this survey aims to provide a profound overview of state-of-the-art developments in the field of EHR RL and to help researchers find the most appropriate methods.
Design of 3DOF Delta Parallel Capture Robot with High Speed and Light Weight
Authors: Jun-lin Ma , Ying Liu , Ying-kun Zhang , Cunming Hao 
Published: February 2022

AbstractFor sucking medicine bottles, according to the particularity of camber surface of the bottle and the sucker, in order to improve the speed, accuracy and stability of capture, this paper presents a 3 degree of freedom Delta parallel robot with high speed and light weight. First, coordinate system of the robot is established, kinematical equationes are obtained based on kinematics analysis and geometric parameter is determined according to specified operation space; Next, trajectory planning is proceeded applying double rounded corner door shape loop which could solve the problem of the wobbling of robot arms; Then, robot structure is designed based on lightweight theory using hollow rod and I-shaped arm; In the end, the prototype is processed with adjustable. Design results show that: capture range is 400 mm x 200 mm, maximum speed is 200 time/min, maximum acceleration is 50 m/s2. Setting operator parameter to the maximum value, repeated positioning experiment is completed. With repeated positioning accuracy 0.385 mm, it is strong evidence that the Delta parallel robot presented by this paper could capture targets accurately, even for smaller ones. The results from this study provide theoretical references for lightweight design and trajectory planning of Delta parallel robot, and because this Delta parallel robot uses only mechanical parts to make this accuracy with no electronic sensor and machine vision module, it lays the foundation for further improvement in accuracy of the Delta parallel robot.
Heat balance analysis of RSG-GAS coolant system due to cooling tower refurbishment
Authors: Sudarmono  , Sutrisno  , Bakhry Syaiful , Hastuti Endiah Puji 
Published: February 2022

Abstract
The RSG-GAS reactor is designed to operate at a power level of 30MW, as stated in the Safety Analysis Report, and currently RSG GAS has been operating for 34 years. Aging of components has been anticipated to ensure the reactor operates safely. Some parts of the structure, system and components (SSC) will experience degradation/aging and must be replaced. Cooling tower is one of them, where the sub components are maintained and tested regularly. Cooling tower aging indication are known from the decreased performance of the reactor cooling system. For this reason, it is necessary to evaluate, both in terms of measurement and calculation analysis, before and after the refurbishment. The efficiency of the cooling tower has been calculated based on the measurement results of the cooling temperature, at the RSG-GAS operation at a power level of 30 MW. From the measurement results, it can be seen that there is a difference in air velocity inlet and outlet of module 1 and module 2. As well as the working temperature of the blower is uneven, the blower temperature ranges from 60.5°C-91.9°C. So that the operation of the RSG GAS could not last long. The efficiency of the cooling tower during the day ranges from 54.72% to 73.23%. The effect of decreasing cooling tower capability can be seen from the calculation results on the performance of each module individually. while its effect on the overall performance is known from the increase in the temperature of the coolant entering the reactor from the HE. The results of the cooling temperature measurement, after refurbishment, show that the cooling tower performance has been able to dissipate heat according to the initial design.