bluuebunny/crossref_metadata_2025_split huggingface dataset:
Asymmetric Hetero-Diels–Alder Reaction of 4-Phenyl-1,2,4-triazole-3,5-dione with 2,4-Dienyl Carboxylic Acids
Authors: Ukaji Yutaka , Sato Yu , Ukei Takahiro , Tsugeno Hiromasa , Suga Takuya , Soeta Takahiro 
Published: July 2023

AbstractThe enantioselective hetero-Diels–Alder reaction of the cyclic azo compound 4-phenyl-1,2,4-triazole-3,5-dione with 2,4-dienyl carboxylic acids was performed using tartaric acid ester as the chiral auxiliary. The corresponding cycloadducts were obtained with enantioselectivities of up to 76% ee. The cis-carboxylic acid produced could be converted into the corresponding cis- and trans-methyl esters by varying the reaction conditions.
Greenium, credit rating, and the COVID-19 pandemic
Authors: Arat Emre , Hachenberg Britta , Kiesel Florian , Schiereck Dirk 
Published: July 2023

AbstractWe analyze green and conventional bonds during regular market periods and within times of extreme volatility, the COVID-19 pandemic. We find a negative premium (greenium) of 1.6 bp before the outbreak of COVID-19, but during the times of extreme market stress, this greenium widens to 3.5 bp as our results show a significant outperformance of green bonds. The results indicate that green bonds are more resilient during risk-off periods than non-green bonds. In addition, the greenium effect is moderated by the issuer's country environmental performance as the greenium is more pronounced for issuers from non-green countries prior to COVID-19. We do not find differences between green and non-green countries since COVID-19.
Lagrangian and Hamiltonian formulations of asymmetric rigid body, considered as a constrained system
Authors: Deriglazov Alexei A 
Published: July 2023

AbstractThis work is devoted to a systematic exposition of the dynamics of a rigid body, considered as a system with kinematic constraints. Having accepted the variational problem in accordance with this, we no longer need any additional postulates or assumptions about the behavior of the rigid body. All the basic quantities and characteristics of a rigid body, as well as the equations of motion and integrals of motion, are obtained from the variational problem by direct and unequivocal calculations within the framework of standard methods of classical mechanics. Several equivalent forms for the equations of motion of rotational degrees of freedom are deduced and discussed on this basis. Using the resulting formulation, we revise some cases of integrability, and discuss a number of peculiar properties, that are not always taken into account when formulating the laws of motion of a rigid body.
Seeing the invisible: convection cells revealed with thermal imaging
Authors: Guido Renzo , Dutra Mateo , Monteiro Martín , Martí Arturo C 
Published: July 2023

Abstract
Fluid instabilities are ubiquitous phenomena of great theoretical and applied importance. In particular, an intriguing example is the thermocapillary or Bénard-Marangoni instability which occurs when a thin horizontal fluid layer, whose top surface is free, is heated from below. In this phenomenon, after passing a certain temperature difference threshold, the fluid develops a regular pattern, usually hexagonal, of convection cells known as Bénard convection. In general, this pattern is not visible to the naked eye unless specific tracers are incorporated into the fluid. The use of thermal imaging is a simple alternative not only for directly observing this phenomenon but also for obtaining valuable quantitative information, such as the relationship between the critical wavelength and the thickness of the fluid layer. Here, we propose an experiment specially suited for laboratory courses in fluid mechanics or nonlinear physics that involves the use of thermal cameras, or appropriate smartphone accessories, to study Bénard convection.
Optical absorption spectra of GaSb/GaAs quantum-ring-with-dot structures and their potential for intermediate band solar cells
Authors: Kunrugsa Maetee 
Published: July 2023

Abstract
Optical absorption spectra of GaSb/GaAs quantum-ring-with-dot structures (QRDSs) are calculated using Fermi’s golden rule by which the electronic states involved in the optical transitions are obtained from the eight-band k ⋅ p method. The absorption spectra of multi-stacked QRDS layers show that the interband and intraband transitions are favorable to intermediate band solar cells (IBSCs). A drift-diffusion model with rate equations for a solar cell containing multi-stacked QRDS layers is formulated based on the absorption spectra. The external quantum efficiency (EQE) determined by the model with the AM1.5 solar spectrum and additional infrared light demonstrates that the confined hole states in the quantum ring (QR) parts of the QRDSs effectively function as an IB. The more efficient two-step photon absorption indicated by the enhancement of the EQE also suggests the potential of QRDSs for the IBSCs.
Effect of CF4 additive on dynamic surface charge deposited on dielectric by helium atmospheric pressure plasma jet
Authors: Han Wen-Hu , Zhang Bo , Guo Wang , Sun Yu-Hao , Fan Lei , Yang Xiong , Sun Ming-Yang , Zhao Hang , Zhang Guan-Jun 
Published: July 2023

Abstract
The addition of active trace components to non-thermal plasmas effectively enhances their chemical activity and has attracted considerable academic attention in the plasma community. It is essential to quantitatively estimate the effect of active addition on the properties of the plasma–surface interaction (PSI). In this study, we focus on the fundamental properties of dynamic surface charge deposited by a He-atmospheric pressure plasma jet (APPJ) with 0%–2% CF4 additive. The charge distribution is measured by a reflective optical measurement platform based on linear electro-optic effect, and is calculated with surface charge density inversion algorithm. Results show that a higher CF4 concentration can shrink the region of surface charge accumulation. Polarity effect is observed in aspects of maximum charge density when the CF4 concentration gradually rises. The negative charge deposition is suppressed by the addition of CF4, nearly disappearing at 2% concentration. While the maximum density of positive charge rises to ∼25 nC cm−2 at 0.5% CF4 before it decreases to ∼10 nC cm−2. The dispersions of total surface charge at 0.5% and 1.5% additives indicate the unstable periodic bombardment of ionization waves in He/CF4 APPJ. The double effect of CF4 additive on the surface charges by He-APPJ is also discussed. These results provide fresh and deep insights into the interaction between dielectric surface modification and ionization waves that occurs in other plasmas processing fed with composite gases.
Electron spin resonance study on the 4f honeycomb quantum magnet YbCl3
Authors: Sichelschmidt Jörg , Häußler Ellen , Vinokurova Ekaterina , Baenitz M , Doert Thomas 
Published: July 2023

Abstract
The local magnetic properties of Yb3+ in the layered honeycomb material YbCl3 were investigated by electron spin resonance on single crystals. For in-plane and out-of-plane field orientations the g-factor shows a clear anisotropy (

g
∥

=
2.97
(
8
)

and

g
⊥

=
1.53
(
4
)

), whereas the low temperature exchange coupling and the spin relaxation display a rather isotropic character. At elevated temperatures the contribution of the first excited crystal field level (

21
±
2

meV) dominates the spin relaxation.
An adaptive selective ensemble algorithm for fault classification
Authors: Zhang Xiaotao , Li Jiangcheng , Liu Fulong , Chen Wei , Dong Limin 
Published: July 2023

Abstract
With the aim of improving the classification performance of a single extreme learning machine (ELM) for fault diagnosis, an adaptive selective ensemble classification algorithm is proposed based on the idea of ensemble learning. The proposed algorithm achieves better classification performance than a single model and the selected ELM subnetworks are selected adaptively and the ensemble weights of selected ELM subnetworks are calculated adaptively, which avoids the complex process of manually selecting subnetworks and calculating ensemble weights. First, a regularized error weight adjustment ELM is constructed by introducing regularization parameters and error weight adjustment matrix to a standard ELM, where the error weight adjustment matrix is obtained by the method of adaptive Gaussian kernel density estimation. Then, discrepancy subnetworks are constructed using six different activation functionsand the ensemble weights of subnetworks are obtained adaptively according to the normalized ratio of mean and variance of subnetwork F-scores to achieve the ensemble of subnetworks. Finally, the adaptive selective ensemble classification algorithm is validated using the UCI dataset and experimental acoustic emission signals of gearbox faults. The results show that the adaptive selective ensemble method can improve the stability and accuracy of classification algorithms and the achieved classification accuracy for experimental acoustic emission was 0.9773.
A new mechanical compound fault diagnosis method based on morphological filter and RLS
Authors: Xue Zhuo , He Dan , Ni ZeXing , Wang Xiufeng 
Published: July 2023

Abstract
Mechanical compound fault diagnosis is a thorny issue in the industry. To overcome this problem, a method named morphological filter—recursive least squares (MF-RLS) is proposed in this paper. In the proposed method, MF-RLS is used to sequentially separate the different fault impulse features by decomposing the observed signal into a series of iterative morphological filtering components (IMFCs). First, the measured signal is decomposed into different scales by the multi-scale MF. Then, the product of kurtosis and envelope harmonic-to-noise ratio index is used to select the best IMFC. Finally, the IMFC is input to RLS to separate other fault features. After continuous iterations, the separation and extraction of the compound fault impulse features are achieved. The simulation and experiment of the mechanical compound fault have verified the effectiveness of the proposed method.
SOI-based 12 × 12 arrayed waveguide grating for fiber Bragg grating interrogation system
Authors: Li Ting , Yuan Pei , Li Shufeng , Li Ke , Zhu Lianqing 
Published: July 2023

Abstract
Fiber Bragg grating (FBG) interrogator is a scientific instrument that can indirectly monitor physical quantities such as temperature and pressure by detecting the center wavelength of FBG. The arrayed waveguide grating (AWG), one of the fundamental parts of the FBG interrogation system, is essential for driving the downsizing of the system and high-speed rate. In this paper, a 12-channel silicon on insulator based AWG with an average 3 dB bandwidth of 2.23

nm

, insertion loss of less than 5 dB, and crosstalk of −16.64 dB is designed and fabricated for a photonic integrated FBG interrogation system. The wavelength resolution of the FBG interrogation system of this AWG is 8

pm

, and the wavelength accuracy measured in the dynamic range of 0.8

nm

is 10.59

pm

. This AWG can be well used in FBG interrogation systems.
Radio-immune response modelling for spatially fractionated radiotherapy
Authors: Cho Young-Bin , Yoon Nara , Suh John H , Scott Jacob G 
Published: July 2023

Abstract

Objective. Radiation-induced cell death is a complex process influenced by physical, chemical and biological phenomena. Although consensus on the nature and the mechanism of the bystander effect were not yet made, the immune process presumably plays an important role in many aspects of the radiotherapy including the bystander effect. A mathematical model of immune response during and after radiation therapy is presented. Approach. Immune response of host body and immune suppression of tumor cells are modelled with four compartments in this study; viable tumor cells, T cell lymphocytes, immune triggering cells, and doomed cells. The growth of tumor was analyzed in two distinctive modes of tumor status (immune limited and immune escape) and its bifurcation condition. Main results. Tumors in the immune limited mode can grow only up to a finite size, named as terminal tumor volume analytically calculated from the model. The dynamics of the tumor growth in the immune escape mode is much more complex than the tumors in the immune limited mode especially when the status of tumor is close to the bifurcation condition. Radiation can kill tumor cells not only by radiation damage but also by boosting immune reaction. Significance. The model demonstrated that the highly heterogeneous dose distribution in spatially fractionated radiotherapy (SFRT) can make a drastic difference in tumor cell killing compared to the homogeneous dose distribution. SFRT cannot only enhance but also moderate the cell killing depending on the immune response triggered by many factors such as dose prescription parameters, tumor volume at the time of treatment and tumor characteristics. The model was applied to the lifted data of 67NR tumors on mice and a sarcoma patient treated multiple times over 1200 days for the treatment of tumor recurrence as a demonstration.
Implementation of cross-scale plane micro-scratching process driven by hybrid piezoelectric actuation
Authors: Su Qi , Sun Jianhua , Deng Jie , Liu Yingxiang , Zhang Shijing 
Published: July 2023

Abstract
The atomic force microscope tip-based mechanical machining technique has been used to fabricate complex micro-structures successfully. However, the machining scope and depth are limited, which holds back this technique severely. This work presents the design and evaluation of a piezoelectric manufacturing system (PMS) for implementation of cross-scale (large scale and high resolution) plane micro-scratching. The PMS has the two-dimensional (2D) micro-machining ability with depths up to 0.98 μm in the millimeter machining scope through the combination of a travel range XY positioning stage and a three-degree-of-freedom (3-DOF) sandwich piezoelectric manipulator. The tracing property of the PMS is feasible for large scale machining by controlling the multi-axis cooperative motion of the 2-DOF stage. The experiments show that the micro-triangles and micro-circles arrays with dimensions from 40 μm to 400 μm are machined successfully. The deviations of the position determination and machined depths for all the micro-structures are less than 5%. Further, it is verified that the manipulator has potential to be used in vibration-assisted cutting to improve machining quality. To sum up, the PMS shows great prospects in the applications of machining cross-scale and large depth planar micro-structures.
Study on helium gas bubble levitation in high field superconducting magnet
Authors: Wei Junwen , Huang Ziyi , Lei Zhiwen , Wu Qiong , Wang Yifan , Kang Xuyang , Li Zi , Yan Zhiyong , Yan Yufan , Jiang Donghui , Qu Timing , Tan Yunfei 
Published: July 2023

Abstract
The abnormal temperature rise and early quench often happened to the high field superconducting magnet, especially when the magnetic field is higher than 20 T. This phenomenon is attributed to helium gas bubbles levitation in the special high magnetic field environment. So, it is very important to accurately identify the formation and distribution of helium gas bubbles levitation for the development of high field superconducting magnet. In this paper, a new analytical method based on pressure is proposed to analysis the formation conditions and the spatial distribution of helium gas bubbles levitation. And a no-insulation REBCO insert coil was also developed to study the phenomenon of helium gas bubbles levitation. The REBCO insert coil was tested in high magnetic field produced by a water-cooled magnet. The new analytical method was used to simulate the formation conditions of helium gas bubbles levitation and the temperature distribution of the REBCO insert.
Investigation of electronic and optical properties of alkali atom doped CuInSe2 using density functional theory
Authors: Sharma Shikha , Khan Karina , Soni Mamta , Ahuja Ushma , Soni Amit , Sahariya Jagrati 
Published: July 2023

Abstract
In this study, the effect of alkali metal (Rb, Cs) doping on the electronic structure of CuInSe2 chalcopyrite have been investigated. The electronic structure of pure and doped chalcopyrites has been interpreted in terms of energy bands and density of states. The doping of Rb and Cs increases the band gap of CuInSe2 from 0.81 eV and attains its maximum value of 1.16 eV with 25% doping of Rb at Cu site. The forbidden gap of doped compounds is found to be suitable for optoelectronic and photovoltaic applications. Therefore, the investigations of various optical properties such as, dielectric tensors, absorption, reflection and refraction spectra, for Cu1−xAxInSe2 (A = Rb, Cs; x = 0, 0.125 and 0.25) compounds are performed to understand the optical performance of all these compounds. The imaginary part of dielectric tensor of pure and doped CuInSe2 are explained with the help of the various inter-band transitions. The refractive index for CuInSe2 is found to be 2.60 which reduces to 2.40 and 2.53 for Cu0.75Rb0.25InSe2 and Cu0.75Cs0.25InSe2 compounds, respectively. All investigations for Cu1−xAxInSe2 (A = Rb, Cs; x = 0, 0.125 and 0.25) compounds have been carried out using density functional theory. Present study shows that doping of Rb and Cs enhances the optoelectronic response of CuInSe2 for its utilization in photovoltaic and optoelectronic applications.
Dynamical behaviors of vertical-cavity surface-emitting lasers with an embedded saturable absorber subjected to an on-off keying (OOK) current modulation
Authors: Temgoua Loannis Pavel Gauss , Mbé Jimmi Hervé Talla , Woafo Paul 
Published: July 2023

Abstract
We numerically study the dynamics of VCSEL-SA when modulated by an analog on-off keying (OOK) current. It is found that the laser gives a pulse-like response when operated below the threshold current. After the threshold current, which is in the excitable phase, the laser generates single spikes (phasic spiking) and a series of spikes (tonic spiking) wherein the amplitude of the spikes varies as the form of the current. Complex dynamics such as bursting oscillations and chaotic dynamics are successfully generated at low frequencies (few MHz). After this excitable phase, the laser copies the OOK current with underdamped oscillations generated during the OFF phase of the OOK current.
Geometric eccentricity effect on thickness-shear vibration of an elliptical flexoelectric crystal plate
Authors: Zheng Yang , Sun Zhenbo , Huang Bin , Guo Yan 
Published: July 2023

Abstract
In this paper, a thickness-shear vibration model for a two-dimensional finite flexoelectric crystal plate with slowly varying thickness and elliptical cross section is presented. The influences of eccentricity and flexoelectricity on the fundamental frequencies of thickness-shear vibration and electric potential distributions under short circuit boundary condition are investigated. The proposed model uses the first order McLaughlin series to approximate the elliptical function and the first derivative of elliptical function is ignored since the plate thickness varies slowly. For the finite plate, the symmetric mode in length and antisymmetric mode in thickness are adopted for the displacement function. In addition, only the shear strain gradient through the thickness is used in the mathematical model for the thin and long flexoelectric crystal plate. By implementing the variational principle, the governing equations are obtained and further solved by the Galerkin method. The obtained frequencies of thickness-shear mode are expressed in terms of eccentricity and length-to-thickness ratio. The results show that the eccentricity has great influence on the nondimensional fundamental frequencies. A small reduction in eccentricity results in significant increment of the nondimensional frequency implying that it is possible to increase the fundamental frequency by changing the cross section of the elliptical flexoelectric plate. The flexoelectric effect is also found to affect the nondimensional frequency and electric potential distribution significantly. Thus, for accurate design of nano/micro scale high precision and high frequency flexoelectric/piezoelectric devices, flexoelectricity must be taken into consideration.
Method of generating roughening paths for shoe soles based on monocular encoded structured light
Authors: Song Limei , Xiang Zhonghao , Wang Yinan , Yang Yangang , Zhu Xinjun , Huang Haozhen 
Published: July 2023

Abstract
In this paper, we propose a monocular encoded structured light-based path generation method for sole roughening, and the obtained paths are used to guide a six-degree-of-freedom (DOF) robot for automatic roughening, which greatly improves the quality and efficiency of roughening. First, we selected monocular structured light as the vision system. To improve the calibration and reconstruction accuracy of the projector, we used an improved Three-Wavelength Phase-Shift Profilometry technique (TWPSP) to calibrate the projector, and the accuracy was improved by 26.29% compared with the conventional method. Then, we proposed a Three Coordinate Scanning Weighted-Principal Component Analysis (TCSW-PCA) algorithm as the path planning system. The experimental results show that the six-DOF-robot can automatically roughen different types of soles according to the generated roughening paths, and the processing efficiency and finished product quality of our proposed method of automatic roughening are better than other roughening methods, with an average improvement of 42% in roughening effect and an average improvement of 30.52% in roughness.
UV-Vis spectroscopic and colorimetric anion detection and fluorescence properties of new 3-amino-4-hydroxybenzenesulfonic acid-based Schiff bases depending on the strength and position of the electron donor substitution
Authors: Yildiz Elif Akhuseyin , Pepe Yasemin , Erdener Diğdem , Karatay Ahmet , Boyacioglu Bahadir , Ünver Hüseyin , Yapar Gönül , Demir Neslihan , Yıldız Mustafa , Elmali Ayhan 
Published: July 2023

AbstractIn this study, 3-amino-4-hydroxybenzenesulfonic acid-based imine compounds; 3-(2,5-dihydroxybenzylideneamino)-4-hydroxybenzenesulfonic acid (1), 3-(2,4-dihydroxybenzylideneamino)-4-hydroxybenzenesulfonic acid (2) and 4-hydroxy-3-(2-hydroxy-3-methoxybenzylideneamino)-4-hydroxybenzenesulfonic acid (3) was synthesized. The compounds were analyzed using various spectroscopy methods, and the experimental UV–vis data matched the theoretical predictions. The compound1displayed lower stability, higher reactivity, and easier photoexcitation due to a smaller HOMO-LUMO energy gap. The investigated compounds1-3showed promise as chemosensors for anions, providing visible detection in daylight conditions. The compound3exhibited selective fluorescence at specific wavelengths. The compounds1-3interacted with DNA through electrostatic interactions. Also, compounds1-3showed higher antioxidant activity than BHT. However, fluorescence measurements indicated that the emission signals were strongly influenced by the position and strength of the electron-donating group. Adding a hydroxy or methoxy moiety near the -OH group on the phenyl ring decreased the fluorescence signal due to intersystem crossing and intramolecular charge transfer mechanisms, respectively. These findings were supported by femtosecond transient absorption spectroscopy measurements. The results emphasize the significance of substituents in imines derived from 3-amino-4-hydroxybenzenesulfonic acid in determining their biological activities, as well as their optical and sensor properties.