bluuebunny/crossref_metadata_2025 huggingface dataset:
CuGBasis: High-performance CUDA/Python library for efficient computation of quantum chemistry density-based descriptors for larger systems
Authors: Tehrani Alireza , Richer Michelle , Heidar-Zadeh Farnaz
Published: August 2024

CuGBasis is a free and open-source CUDA®/Python library for efficient computation of scalar, vector, and matrix quantities crucial for the post-processing of electronic structure calculations. CuGBasis integrates high-performance Graphical Processing Unit (GPU) computing with the ease and flexibility of Python programming, making it compatible with a vast ecosystem of libraries. We showcase its utility as a Python library and demonstrate its seamless interoperability with existing Python software to gain chemical insight from quantum chemistry calculations. Leveraging GPU-accelerated code, cuGBasis exhibits remarkable performance, making it highly applicable to larger systems or large databases. Our benchmarks reveal a 100-fold performance gain compared to alternative software packages, including serial/multi-threaded Central Processing Unit and GPU implementations. This paper outlines various features and computational strategies that lead to cuGBasis’s enhanced performance, guiding developers of GPU-accelerated code.
The CXSFIT spectral fitting code: Past, present and future
Authors: Delabie E. , O’Mullane M. G. , von Hellermann M. , Whiteford A. , Horton L. D. , Zastrow K. D. , Menmuir S. , Litherland-Smith E. , Meigs A. , Biewer T. M. ,   EUROfusion Tokamak Exploitation Team,   JET Contributors
Published: August 2024

Magnetically confined plasma experiments generate a wealth of spectroscopic data. The first step toward extracting physical parameters is to fit a spectral model to the often complex spectra. The CXSFIT (Charge eXchange Spectroscopy FITting) spectral fitting code was originally developed for fitting charge exchange spectra on JET from the late 1980s onward and has been further developed over decades to keep up with the needs of the users. The primary use is to efficiently fit a large number of spectra with many constrained Gaussian spectral lines of which the physical parameters can be coupled in a user-friendly manner. More recent additions to the code include time-dependent couplings between parameters, flexible background subtraction, and a non-linear coupling scheme between fit parameters. The latter was a pre-requisite for implementing Zeeman and motional Stark effect multiplets in the library of spectral features. The ability to save and replay “fit recipes,” even when multiple iterations are required, has ensured the traceability of the results and is one of the keys to the longevity and success of the code. The code is also in use on other tokamaks (AUG, ST-40) and to fit data from other spectroscopic diagnostics on JET. In this paper, we document the current capabilities and philosophy behind the structure of the code, including some of the algorithms used to calculate spectral features numerically efficiently. We also provide an outline of how CXSFIT could be transferred into a framework that would be able to meet the spectral fitting requirements of future devices, such as ITER.
Giant tunneling resistance and robust switching behavior in ferroelectric tunnel junctions of WS2/Ga2O3 heterostructures: The influence of metal–semiconductor contacts
Authors: Wei Dong , Guo Gaofu , Yu Heng , Li Yi , Ma Yaqiang , Tang Yanan , Feng Zhen , Dai Xianqi
Published: August 2024

The ferroelectric tunneling junctions (FTJs) are widely recognized as one of the non-volatile memories with significant potential. Ferroelectricity usually fades away as materials are thinned down below a critical value, and this problem is particularly acute in the case of shrinking device sizes, thus attracting attention to two-dimensional ferroelectric materials (2DFEMs). In this work, we designed 2D ferroelectric Ga2O3-based FTJs with out-of-plane polarization, and the influence of metal–semiconductor contact in the electrode region on the system is considered. Here, using density functional theory combined with the non-equilibrium Green's function approach to quantum transport calculations, we demonstrate robust ferroelectric polarization-controlled switching behavior between metallic and semiconducting states in Ga2O3/WS2 ferroelectric heterostructures. The potential barrier of the metal–semiconductor contact in the electrode region is lower than that of the intrinsic material, thereby resulting in an increased probability of electron tunneling. Our results reveal the crucial role of 2DFEMs in the construction of FTJs and highlight the significant impact of electrode contact types on performance. This provides a promising approach for developing high-density ferroelectric memories based on 2D ferroelectric semiconductor heterostructures.
Stable optical response during electron–phonon equilibration in laser-excited gold
Authors: Ndione P. D. , Weber S. T. , Rethfeld B. , Gericke D. O.
Published: August 2024

We study the optical response of solid gold driven by ultrashort pulses of visible light by tracking the conduction band density and damping rates. While we find rapid changes in optical properties during and shortly after the laser excitation, we obtain an almost unchanged reflectivity during the stage of electron–phonon temperature equilibration. These predictions are in good agreement with experimental data and exhibit a strong compensation of damping mechanisms as a source for the stable response, although electron and ion temperatures change significantly. Considering the complex interplay of damping processes in solid gold, our model gives a more fundamental interpretation of optical measurements than existing approaches.
Beyond lithium-ion batteries: Are effective electrodes possible for alkaline and other alkali elements? Exploring ion intercalation in surface-modified few-layer graphene and examining layer quantity and stages
Authors: Lin Yu-Hsiu , Mendoza-Cortes Jose L.
Published: August 2024

In the pursuit of reliable energy storage solutions, the significance of engineering electrodes cannot be overstated. Previous research has explored the use of surface modifiers (SMs), such as single-side fluorinated graphene, to enhance the thermodynamic stability of ion intercalation when applied atop few-layer graphene (FLG). As we seek alternatives to lithium-ion batteries (LIBs), earth-abundant elements like sodium and potassium have emerged as promising candidates. However, a comprehensive investigation into staging intercalation has been lacking thus far. By delving into staging assemblies, we have uncovered a previously unknown intercalation site that offers the most energetically favorable binding. Here, we study the first three elements in both alkali (Li, Na, K) and alkaline (Be, Mg, Ca) earth metals. Furthermore, the precise mechanism underlying this intercalation system has remained elusive in prior studies. In our work, we employed density functional theory calculations with advanced hybrid functionals to determine the electrical properties at various stages of intercalation. This approach has been proven to yield more accurate and reliable electrical information. Through the analysis of projecting density of states and Mulliken population, we have gained valuable insights into the intricate interactions among the SM, ions, and FLG as the ions progressively insert into the structures. Notably, we expanded our investigation beyond lithium and explored the effectiveness of the SM on ions with varying radii and valence, encompassing six alkali and alkaline earth metals. Additionally, we discovered that the number of graphene layers significantly influences the binding energy. Our findings present groundbreaking concepts for material design, offering diverse and economically viable alternatives to LIBs. Furthermore, they serve as a valuable reference for fine-tuning electrical properties through staging intercalation and the application of SMs.
ACE: A general-purpose non-Markovian open quantum systems simulation toolkit based on process tensors
Authors: Cygorek Moritz , Gauger Erik M.
Published: August 2024

We describe a general-purpose computational toolkit for simulating open quantum systems, which provides numerically exact solutions for composites of zero-dimensional quantum systems that may be strongly coupled to multiple, quite general non-Markovian environments. It is based on process tensor matrix product operators (PT-MPOs), which efficiently encapsulate environment influences. The code features implementations of several PT-MPO algorithms, in particular Automated Compression of Environments for general environments comprised of independent modes as well as schemes for generalized spin boson models. The latter includes a divide-and-conquer scheme for periodic PT-MPOs, which enable million time step simulations for realistic models. PT-MPOs can be precalculated and reused for efficiently probing different time-dependent system Hamiltonians. They can also be stacked together and combined to provide numerically complete solutions of small networks of open quantum systems. The code is written in C++ and is fully controllable by configuration files, for which we have developed a versatile and compact human-readable format.
3d orbital electron tunning and crystal engineering enables high-capacity vanadium oxide for aqueous ammonium ion batteries
Authors: Lu Tzu-Hao , Liu Qiyu , Yi Ang , Liu Hao , Yu Yanxia , Lu Xihong
Published: August 2024

Vanadium pentoxide (V2O5) has shown great potential as the electrode for aqueous ammonium ion batteries (AAIBs) owing to its good electrochemical reversibility and high theoretical capacity. However, the electrochemical performance of V2O5 is seriously limited by the weak NH4+ adsorption capability and insufficient active sites of vanadium oxide originated from the unsuitable 3d orbital electron state. Herein, the strategy of a 3d orbital electron tunning and crystal engineering is used to increase the ammonium ion storage capacity of V2O5 electrode. The experimental results show that the modified 3d orbital state of V4+ (t2g1) can effectively increase the active sites of V2O5. Therefore, the as-prepared N-VO exhibits a high specific capacity of 249.3 mA h g−1 at 1.0 A g−1 and 69.5 mA h g−1 at 10.0 A g−1, superior to other reported anode material for AAIBs. Noticeably, the prepared resultant quasi-solid-state ammonium ion battery can display considerable cycling stability with capacity retention of 87.9% after a long cycle life of 10 000 cycles at 1 A g−1 and impressive mechanical flexibility with no capacity decay after cycling at different bending angles.
Phase transition kinetics and sublayer optimization of HfO2/ZrO2 superlattice ferroelectric thin films
Authors: Wang Yufan , Zhu Chuqian , Sun Huajun , Wang Wenlin , Zou Lanqing , Yi Yunhui , Xu Jiyang , Ren Jiawang , Hu Sheng , Ye Lei , Cheng Weiming , He Qiang , Miao Xiangshui
Published: August 2024

The sublayer thickness of superlattices, as a key factor affecting lattice integrity, interface defects, and strain, deserves in-depth studies about its impact on improving ferroelectric properties. This study described and analyzed the performance of HfO2/ZrO2 superlattices with various sublayer thicknesses. It can be concluded that the structure of the thicker layers will guide the trend of the phase composition of the entire device: when ZrO2 layers are thicker, the superlattices will exhibit antiferroelectricity due to the higher content of the tetragonal phase (t-phase); when HfO2 layers become thicker, the fraction of the monoclinic phase (m-phase) will increase, leading to a decrease in ferroelectricity and an increase in leakage current. In this way, the device with a 1:1 HfO2/ZrO2 thickness ratio was optimized to have the largest remanent polarization and the lowest leakage current. Maintaining the same thickness ratio of the HfO2/ZrO2 superlattices, it was found that HfO2/ZrO2 superlattices with thinner sublayers exhibited a larger remanent polarization (Pr) value due to increased interlayer distortion. On the contrary, the thicker sublayers reduced leakage current, which was beneficial for improving the device lifespan.
A novel subgrid-scale stress model considering the influence of combustion on turbulence: A priori and a posteriori assessment
Authors: Wang Yicun , Luo Kun , Xiao Hualin , Jin Tai , Xing Jiangkuan , Fan Jianren
Published: August 2024

Most classical turbulence models were proposed and developed based on non-reacting flows without considering the effects of combustion on turbulence. The flow structure in turbulent combustion is more complex, creating challenges to the applicability of traditional turbulence models. Given this, a novel flame surface and k-equation-based gradient model (FKGM) considering combustion effects is proposed for the modeling of the subgrid-scale (SGS) stress in large eddy simulation (LES). The SGS stress is calculated based on the SGS kinetic energy (kSGS) and normalized velocity gradient. The velocity gradient incorporates first-order gradients at multiple stencil locations and considers the anisotropy of the stress near the flame surface. The FKGM model is first validated by the a priori analysis based on the direct numerical simulation (DNS) database of a premixed swirling flame. The closure terms of the kSGS equation are well validated, and the predicted SGS stress using the FKGM model achieves good agreement with the filtered DNS results. In the a posteriori LES study, the FKGM model demonstrates better performance compared with the traditional dynamic Smagorinsky model and velocity gradient model, providing more accurate predictions for mean and fluctuation velocities. The error analysis for SGS kinetic energy is further conducted by comparing the LES results with the DNS data, and the results indicate that the underestimation of the generation term of the kSGS equation is the main source of error.
Isolation of individual Er quantum emitters in anatase TiO2 on Si photonics
Authors: Ji Cheng , Pettit Robert M. , Gupta Shobhit , Grant Gregory D. , Masiulionis Ignas , Sundaresh Ananthesh , Deckoff–Jones Skylar , Olberding Max , Singh Manish K. , Heremans F. Joseph , Guha Supratik , Dibos Alan M. , Sullivan Sean E.
Published: August 2024

Defects and dopant atoms in solid state materials are a promising platform for realizing single photon sources and quantum memories, which are the basic building blocks of quantum repeaters needed for long distance quantum networks. In particular, trivalent erbium (Er3+) is of interest because it couples C-band telecom optical transitions with a spin-based memory platform. In order to produce quantum repeaters at the scale required for quantum networks it is imperative to integrate these necessary building blocks with mature and scalable semiconductor processes. In this work, we demonstrate the optical isolation of single Er3+ ions in CMOS-compatible titanium dioxide (TiO2) thin films monolithically integrated on a silicon-on-insulator photonics platform. Our results demonstrate an initial step toward the realization of a monolithically integrated and scalable quantum photonics package based on Er3+ doped thin films.
Microwave magnetic excitations in U-type hexaferrite Sr4CoZnFe36O60 ceramics
Authors: Kempa M. , Bovtun V. , Repček D. , Buršík J. , Kadlec C. , Kamba S.
Published: August 2024

Microwave (MW) transmission, absorption, and reflection loss spectra of the ferrimagnetic U-type hexaferrite Sr4CoZnFe36O60 ceramics were studied from 100 MHz to 35 GHz at temperatures between 10 and 390 K. Nine MW magnetic excitations with anomalous behavior near ferrimagnetic phase transitions were revealed. They also change under the application of the weak bias magnetic field (0–700 Oe) at room temperature. Six pure magnetic modes are assigned to dynamics of the magnetic domain walls and inhomogeneous magnetic structure of the ceramics, to the natural ferromagnetic resonance (FMR), and to the higher-frequency magnons. Three modes are considered the magnetodielectric ones with the dominating influence of the magnetic properties on their temperature and field dependences. The presence of the natural FMR in all ferrimagnetic phases proves the existence of the non-zero internal magnetization and magnetocrystalline anisotropy. Splitting of the FMR into two components without magnetic bias was observed in the collinear phase and is attributed to a change in the magnetocrystalline anisotropy during phase transition. The high-frequency FMR component critically slows down to phase transition. At room temperature, FMR splitting and essential suppression of the higher-frequency modes were revealed under the weak bias field (300–700 Oe). The highly nonlinear MW response and FMR splitting are caused by the gradual evolution of the polydomain magnetic structure to a monodomain one. The high number of magnetic excitations observed in the MW region confirms the suitability of using hexaferrite Sr4CoZnFe36O60 ceramics as MW absorbers, shielding materials and highly tunable filters.
Hysteresis related to ion migration rather than ferroelectric polarization in MAPbI3
Authors: Zou Yihui , Ding Yi , Hu Haihua , Zhang Jingji , Li Huilin , Lin Ping , Wang Peng , Wu Xiaoping , Xu Lingbo , Cui Can
Published: August 2024

Understanding ferroelectric characteristic is crucial, especially for elucidating the existence of ferroelectric and its relationship with hysteresis in hybrid organic–inorganic perovskites. Our focus is to evaluate the ferroelectric properties of MAPbI3 perovskite films by suppressing the rotation of the MA+ ions through the substitution of TMA+ cations. Our findings indicate that both MAPbI3 and MA0.85TMA0.15PbI3 exhibit non-ferroelectric properties at room temperature, which persist even after external polarization treatment. Further analysis reveals that the hysteresis in J–V characteristics is associated with ion migration phenomena. The external polarization treatment aids in releasing electrons from defect states, enabling them to revert to their original lattice sites. As a result, devices subjected to polarization treatment exhibit reduced hysteresis and enhanced photovoltaic performance.
Specific line shape of the lowest frequency Raman scattering modes of triethylene glycol
Authors: Ozama Koshi , Amo Yuko , Kameda Yasuo , Usuki Takeshi , Umebayashi Yasuhiro , Watanabe Hikari
Published: August 2024

For both dielectric spectroscopy and light scattering spectra, the relaxation modes in the microwave region have been characterized by the Debye relaxation model, which is determined by the peak frequency, or by an empirically extended model (e.g., Cole–Davidson and Kohlrausch–Williams–Watts), which has the appropriate line shape. For light scattering from glass-forming liquids, the general line shape is a broader high frequency side in comparison with Debye relaxation. However, for triethylene glycol (TEG) in liquid form at room temperature, the lowest frequency Raman scattering (LFR) mode shows a peak at about 3.0 GHz, which is narrower than that expected for the Debye relaxation. With increasing temperature, this peak exhibits a significant blueshift and begins to resemble the Debye relaxation shape, indicating that the LFR mode of TEG is also a relaxation mode. The narrowing of the LFR mode of TEG is suggested to be caused from the increased non-whiteness of the fluctuation correlations due to increased hydrogen bonding. This is a consequence of breaking the Debye relaxation model’s approximation of the overdamping and narrowing limits in the GHz region, which was found in this study by analyzing the relaxation modes of Raman scattering using the multiple random telegraph model for evaluating thermal bath correlation. The analysis results show that the LFR relaxation times of TEG and the main dielectric relaxation overlap only by 333 K. However, the second LFR mode and β-relaxation at higher frequencies coincide over a wide temperature range, suggesting that they are corresponding modes.
Assessment of physiological and biochemical responses of chilli (Capsicum annuum) varieties in floating bed cultivation for adaptation to waterlogged areas of Bangladesh
Authors: Al-Imran Md. , Karmaker Dipalok , Mitra Shawon , Haider Ishita , Rahman Md. Alimur , Das Subroto K.
Published: August 2024

Chilli (Capsicum annuum) is an important spice crop in Bangladesh. This crop is very sensitive to waterlogging. Floating agriculture is an innovative system led by the local people of the southern region of Bangladesh, in which seedlings of vegetables are produced in low-lying areas using different aquatic macrophytes. An experiment was carried out to evaluate the viability of chilli cultivation in waterlogged areas, based on physiological and biochemical responses using floating agriculture. Eight different chilli varieties were subjected to floating agriculture in two different agronomic seasons. A soil-based chilli cultivation system was also trialled, to compare the utility of this method. To evaluate the performance of chilli in floating beds, plant water status, photosynthetic parameters, and leaf tissue concentrations of Na+, K+, NO3− and PO43−, chlorophyll, ascorbic acid and proline were assessed. This study shows that macrophytes utilised in floating beds provide favourable conditions for chilli cultivation under waterlogged conditions. Among the different varieties, Sakata 653 in summer and Jhilik in winter responded better than others. As the performance of chilli in the floating agriculture system was satisfactory in comparison with soil-based cultivation, floating agriculture can be an alternative agronomic method for chilli cultivation in waterlogged areas of Bangladesh.
Evolving dual-trait EPSP synthase variants using a synthetic yeast selection system
Authors: Reed Kevin B. , Kim Wantae , Lu Hongyuan , Larue Clayton T. , Guo Shirley , Brooks Sierra M. , Montez Michael R. , Wagner James M. , Zhang Y. Jessie , Alper Hal S.
Published: August 2024

The enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) functions in the shikimate pathway which is responsible for the production of aromatic amino acids and precursors of other essential secondary metabolites in all plant species. EPSPS is also the molecular target of the herbicide glyphosate. While some plant EPSPS variants have been characterized with reduced glyphosate sensitivity and have been used in biotechnology, the glyphosate insensitivity typically comes with a cost to catalytic efficiency. Thus, there exists a need to generate additional EPSPS variants that maintain both high catalytic efficiency and high glyphosate tolerance. Here, we create a synthetic yeast system to rapidly study and evolve heterologous EPSP synthases for these dual traits. Using known EPSPS variants, we first validate that our synthetic yeast system is capable of recapitulating growth characteristics observed in plants grown in varying levels of glyphosate. Next, we demonstrate that variants from mutagenesis libraries with distinct phenotypic traits can be isolated depending on the selection criteria applied. By applying strong dual-trait selection pressure, we identify a notable EPSPS mutant after just a single round of evolution that displays robust glyphosate tolerance (K
i
of nearly 1 mM) and improved enzymatic efficiency over the starting point (~2.5 fold). Finally, we show the crystal structure of corn EPSPS and the top resulting mutants and demonstrate that certain mutants have the potential to outperform previously reported glyphosate-resistant EPSPS mutants, such as T102I and P106S (denoted as TIPS), in whole-plant testing. Altogether, this platform helps explore the trade-off between glyphosate resistance and enzymatic efficiency.
Global preventive feedback of powerful radio jets on galaxy formation
Authors: Cen Renyue
Published: August 2024

Firmly anchored on observational data, giant radio lobes from massive galaxies hosting supermassive black holes can exert a major negative feedback effect, by endowing the intergalactic gas with significant magnetic pressure hence retarding or preventing gas accretion onto less massive halos in the vicinity. Since massive galaxies that are largely responsible for producing the giant radio lobes, this effect is expected to be stronger in more overdense large-scale environments, such as protoclusters, than in underdense regions, such as voids. We show that by redshift

z
=
2

halos with masses up to

(

10

11

to

12

,

10

12

to

13

)

M
⊙

are significantly hindered from accreting gas due to this effect for radio bubble volume filling fraction of

(
1.0
,
0.2
)

, respectively. Since the vast majority of the stars in the universe at

z

<

2 to 3 form precisely in those halos, this negative feedback process is likely one major culprit for causing the global downturn in star formation in the universe. It also provides a natural explanation for the rather sudden flattening of the slope of the galaxy rest-frame UV luminosity function around

z
∼
2

. A cross-correlation between protoclusters and Faraday rotation measures may test the predicted magnetic field. Inclusion of this external feedback process in the next generation of cosmological simulations may be imperative.
Twistor theory of the Chen–Teo gravitational instanton*
Authors: Dunajski Maciej , Tod Paul
Published: August 2024

Toric Ricci–flat metrics in dimension four correspond to certain holomorphic vector bundles over a twistor space. We construct these bundles explicitly, by exhibiting and characterising their patching matrices, for the five–parameter family of Riemannian ALF metrics constructed by Chen and Teo. The Chen–Teo family contains a two–parameter family of asymptotically flat gravitational instantons. The patching matrices for these instantons take a simple rational form.
Effective anisotropic dynamics in group field theory cosmology
Authors: Oriti Daniele , Wang Yi-Li
Published: August 2024

We study the emergent dynamics of an anisotropic Universe in the context of group field theory condensate cosmology, with a scalar field playing the role of a relational clock. According to different definitions of ‘isotropy’, two anisotropic condensate states are considered and the Bianchi-like dynamics of cosmological anisotropic observables, as well as their quantum fluctuations, are analysed. We find that both anisotropic states become isotropic at late time, reproducing an effective Friedmann dynamics, while anisotropies give small but non-negligible contributions at earlier times, closer to the cosmic bounce.
On the implementation of acollinearity in PET Monte Carlo simulations
Authors: Toussaint Maxime , Loignon-Houle Francis , Auger Étienne , Lapointe Gabriel , Dussault Jean-Pierre , Lecomte Roger
Published: August 2024

Objective. Acollinearity of annihilation photons (APA) introduces spatial blur in positron emission tomography (PET) imaging. This phenomenon increases proportionally with the scanner diameter and it has been shown to follow a Gaussian distribution. This last statement can be interpreted in two ways: the magnitude of the acollinearity angle, or the angular deviation of annihilation photons from perfect collinearity. As the former constitutes the partial integral of the latter, a misinterpretation could have significant consequences on the resulting spatial blurring. Previous research investigating the impact of APA in PET imaging has assumed the Gaussian nature of its angular deviation, which is consistent with experimental results. However, a comprehensive analysis of several simulation software packages for PET data acquisition revealed that the magnitude of APA was implemented as a Gaussian distribution. Approach. We quantified the impact of this misinterpretation of APA by comparing simulations obtained with GATE, which is one of these simulation programs, to an in-house modification of GATE that models APA deviation as following a Gaussian distribution. Main results. We show that the APA misinterpretation not only alters the spatial blurring profile in image space, but also considerably underestimates the impact of APA on spatial resolution. For an ideal PET scanner with a diameter of 81 cm, the APA point source response simulated under the first interpretation has a cusp shape with 0.4 mm FWHM. This is significantly different from the expected Gaussian point source response of 2.1 mm FWHM reproduced under the second interpretation. Significance. Although this misinterpretation has been found in several PET simulation tools, it has had a limited impact on the simulated spatial resolution of current PET scanners due to its small magnitude relative to the other factors. However, the inaccuracy it introduces in estimating the overall spatial resolution of PET scanners will increase as the performance of newer devices improves.
Preparation and reliability performance evaluation of electro-spun strain sensing membrane
Authors: Mohamadi Parian , Zaman Shahood uz , Mohsenzadeh Elham , Cochrane Cedric , Koncar Vladan
Published: August 2024

The development of textile-based strain sensors signifies a new era for diverse e-textile applications spanning various fields, including health monitoring and sensing equipment. Over decades, the sensor field has experienced significant advancements, incorporating enhancements in sensing accuracy, resolution, measurement range, and robustness, among other aspects. Our article initially focuses on the creation of textile-based strain membrane sensors customized for a range of industrial applications, such as air filter clogging detection and airflow analysis. In the subsequent part of the study, the reliability and washability performance of the sensing membrane, without mechanical damage, were investigated. To achieve this, thermoplastic polyurethane nanofibers were utilized to fabricate a textile sensory membrane. Subsequently, this membrane air transparent (low-pressure drop) and highly resilient was used as a substrate to print strain gauge tracks using carbon conductive ink, with the aid of a flexible printed circuit board printer. The resulting samples underwent comprehensive evaluation for reliability and washability. Prototype membranes were subjected to twelve wash cycles in a top-loading washing machine to assess washing reliability. Both the mechanical and electromechanical properties of the strain membrane sensors were examined both before and after the washing process. The gauge factor of the straight line decreased from 18.14 (region I) and 86.03 (region II) to 20.22 after washing. This value reduced from 0.88 and 4.20 to 0.33, and from 13 and 2.77 to 3.29 and 0.81 for the big zigzag and small zigzag, respectively. Similarly, electrical resistance change after 12 wash cycles was negligible with maximum change 1.12. These results indicate that sensors maintain their functionality even after exposure to multiple washing cycles. In conclusion, it can be inferred that textile-based sensory membranes are well-suited for industrial applications aiming at the measurement of low and high-speed airflows subject to rigorous washing and other potential mechanical stresses.
Speckle reduction in digital holography with Non-local means filter based on the structural similarity
Authors: Chen Honghui , Chen Li , Xie Zhaoqian , Wen Kunhua
Published: August 2024

Speckle noise limits the application of digital holography across various fields. This paper proposes a Non-local means filter method to suppress speckle noise by determining the weight of each traversed pixel based on the structural similarity between image blocks centered on the target and traversed pixels. Experimental results show that, compared to other typical digital image processing methods, this method can significantly reduce the speckle noise and exhibits a clear advantage across various metrics. These results indicate that the proposed method holds significant development potential in the field of speckle noise reduction.
Frozen condition of quantum coherence
Authors: Bai Zhaofang , Du Shuanping
Published: August 2024

Quantum coherence as an important physical resource plays the key role in implementing various quantum tasks, whereas quantum coherence is generally nonincreasing under incoherent operations. In this paper, we analyse under which dynamical conditions the l
1-norm or the relative entropy of coherence can remain unchanged under strictly incoherent operations (freezing coherence). We provide a detailed analysis of their structure together with exact geometric conditions of freezing coherence. It reveals a remarkable feature: any strictly incoherent operation freezing coherence can be decomposed as a convex combination of unitary operations. This partially answers an open question named unitary decomposition of doubly-stochastic quantum operations [M. A. Nielsen and I. L. Chuang, Quantum Computation and Quantum Information, (Cambridge University Press, Cambridge, 2000)]. Based on this analysis, we also give a complete classification of coherent states from operational coherence theory. This builds the counterpart of entanglement classification under LOCC.
Design and investigation of a terahertz hollow-core fiber with double-layer ring core for OAM mode transmission
Authors: Chen Xiangmei , Yan Dexian , Qiu Jianzhong , Zhu Zhenghan , Li Xiangjun , Zhang Le , Sun Shuai , Li Jining
Published: August 2024

A terahertz hollow-core fiber having a double-layer ring core is presented and investigated to support OAM mode transmission. These two annular cores will work as two separate OAM transmission spaces that are not interfered with and can support more OAM mode transmissions. A numerical model has been developed to assess the transmission performances of EH and HE modes in the 0.3∼0.4 THz frequency band. Using only a single material to design the suggested fiber, 22 (in) + 58 (out) OAM modes can be stably transmitted at 0.36 THz. Neighboring EH and HE modes in the identical OAM family can obtain effective refractive index differences of more than 10−4. Furthermore, the designed fiber demonstrates excellent transmission properties, with the highest mode purities in the inner and outer rings being 92.22% and 93.78%, respectively. In the inner ring the effective mode field area is between 5.37 × 106 and 1.79 × 107 μm2, while in the outer ring, it is between 8.95 × 106 and 1.58 × 107 μm2. The HE1,1 mode has the smallest change in dispersion, with values of 2.76 and 0.87 ps THz−1 cm−1 in two high refractive index transmission ring cores, respectively. Additionally, the isolation (ISO) parameter is also analyzed. These mode characteristics indicate that the fiber structure has significant potential for applications in high-capacity terahertz communication systems.
Clock noise evaluation of space-based gravitational wave detectors based on time-delay interferometry
Authors: Lu Xiao-Yu , Wang Ya-Jie , Li Zhi-Gang
Published: August 2024

The heterodyne measurements are adopted in space-based gravitational wave detectors to detect gravitational wave signals in the millihertz range. Due to the difficulty in maintaining the equal distance between these spacecrafts in the detector, laser phase noise is a main noise in the detection process, so time-delay interferometry combination is adopted to eliminate this noise by synthesizing virtual equal arm interferometry. However, when conducting heterodyne laser interferometry measurements in space-based gravitational wave detection, clock noise is also introduced into the measurement, but the analytical results of clock noise have been ignored in previous studies. Based on time-delay interferometry combination, we analyze the impact of clock noise and provide analytical results of the total noise in various data combinations. Through this result, we evaluate the required clock accuracy of 10−16 for the gravitational wave detector when clock noise is not reduction, so the analytical result can more intuitively reflect how the clock noise effects the sensitivity of the detector.
Structural, optical spectroscopic, and density functional theory calculations of squaraine dye for organic electronic applications
Authors: Hassanien A M , Darwish A A A , Alharbi Abdulrahman Faraj , Abahussain Abdulaziz A M , Hermi Sabrine , Mrad Mohamed Habib
Published: August 2024

The structural, optical spectroscopic, and density functional theory calculations of 2,4-Bis[4-(N,N-diisobutylamino)−2,6-dihydroxyphenyl] squaraine dye (SQ) are promising investigations that can be useful in photochemical mechanisms explanation and in designing promising chemosensors. The nature of the bonds, the chemical composition of SQ, crystallographic structure, morphology, and quality characteristics were explored by FTIR, XRD, and SEM investigations. The crystallite size, the dislocation density, and the lattice strain were found to be 57.3 nm, 3.045 × 10−4 nm−2, and 3.065 × 10−3, respectively. The spectrum behavior of the absorbance and molar absorption coefficient spectra of SQ in DCM with three concentrations were analyzed to get some important optical properties of SQ dye. The determined optical gap transition equals

E

g
a
p

o
p
t

=
1.81

eV
.

Quantum chemical computations and optimized molecular geometries identified where electrophilic attacks are likely and analyzed the molecule’s electrostatic potential. Using DFT calculations at the B3LYP/6-31+G(d,p) level, the electronic structure of the squaraine molecule was confirmed, showing a HOMO–LUMO gap of 1.73 eV. MEP analysis indicated that the oxygen atoms are electron-rich, suggesting potential for hydrogen bonding and electrophilic interactions.
Novel nonlinear wave transitions and interactions for (2+1)-dimensional generalized fifth-order KdV equation
Authors: Li Yan , Yao Ruoxia , Lou Senyue
Published: August 2024

The (2 + 1)-dimensional generalized fifth-order KdV (2GKdV) equation is revisited via combined physical and mathematical methods. By using the Hirota perturbation expansion technique and via setting the nonzero background wave on the multiple soliton solution of the 2GKdV equation, breather waves are constructed, for which some transformed wave conditions are considered that yield abundant novel nonlinear waves including X/Y-Shaped (XS/YS), asymmetric M-Shaped (MS), W-Shaped (WS), Space-Curved (SC) and Oscillation M-Shaped (OMS) solitons. Furthermore, distinct nonlinear wave molecules and interactional structures involving the asymmetric MS, WS, XS/YS, SC solitons, and breathers, lumps are constructed after considering the corresponding existence conditions. The dynamical properties of the nonlinear molecular waves and interactional structures are revealed via analyzing the trajectory equations along with the change of the phase shifts.
Nonexistence of Majorana fermions in Kerr-Newman type spacetimes with nontrivial charge*
Authors: Zhang 张 He-Qun 鹤群 , Zhang 张 Xiao 晓
Published: August 2024

We show that the Dirac equation is separated into four differential equations for time-periodic Majorana fermions in Kerr-Newman and Kerr-Newman-(A)dS spacetimes. Although they cannot be transformed into radial and angular equations, the four differential equations yield two algebraic identities. When the electric or magnetic charge is nonzero, they conclude that there is no differentiable time-periodic Majorana fermions outside the event horizon in Kerr-Newman and Kerr-Newman-AdS spacetimes, or between the event horizon and the cosmological horizon in Kerr-Newman-dS spacetime.
Traceable characterisation of fibre-coupled single-photon detectors
Authors: Arabskyj Luke , Dolan Philip R , Parke Adam L , Santana Ted S , Hall Simon R G , Porrovecchio Geiland , Smid Marek , Lucamarini Marco , Chunnilall Christopher J
Published: August 2024

The detection of single photons plays an essential role in advancing single-photon science and technologies. Yet, within the visible/near-infrared spectral region, accurate fibre-based optical power measurements at the few-photon level are not yet well-established. In this study, we report on a fibre-based setup, enabling traceable optical power measurements at the few-photon level in this spectral region. The setup was used to calibrate the detection efficiency (DE) of four single-photon avalanche diode (SPAD) detectors. The relative standard uncertainties on the mean DE values obtained from repeat fibre-to-detector couplings ranged from 0.67% to 0.81% (k = 2). However, the relative standard deviation of DE values, which ranged from 1.38% to 3.20% (k = 2), poses a challenge for the metrology of these devices and applications that require high accuracy and repeatability. We investigated the source of these variations by spatially mapping the response of a detector’s fibre connector port, using a focused free-space beam, allowing us to estimate the detector’s spatial non-uniformity. In addition, we realise a novel calibration approach for fibre-coupled SPADs in a free-space configuration, enabling a direct comparison between the fibre-based setup and the National Physical Laboratory’s established free-space facility using a single SPAD. Finally, we investigated alternative coupling methods, testing the repeatability of different fibre-to-fibre connectors in addition to direct fibre-to-detector couplings: SPADs from three manufacturers were tested, with both single-mode and multi-mode fibre.
Research status and application of 304/Q235 stainless steel clad plate
Authors: Liang Shun , Wang Xingxing , Chen Yuhang , Ni Hongjun , Zhu Yu
Published: August 2024

Due to the increasing severity of corrosion and impact on the bridge deck, the material requirements for railroad steel bridges are becoming more stringent. The 304/Q235 stainless steel composite steel plate has gained attention as a new material due to its excellent corrosion resistance and mechanical properties. This is particularly relevant for the large span of the railroad steel bridge across the river and sea. This paper analyzes the research and application of various process methods used in the preparation of 304/Q235 composite plate, including electroslag welding-hot rolling composite method, laser welding, multi-layer explosive welding process, stirring friction welding, laser cladding, and hot press bonding process method. The advantages, disadvantages, and effects of each method are summarized. The study demonstrates that improving the comprehensive performance of stainless steel composite steel plates is a bottleneck in the industry. Therefore, accurately selecting the combination of stainless steel composite steel plate and optimizing the manufacturing process are the key focuses for the industry. This text provides a useful reference for the future development direction of composite steel. It also offers theoretical and practical support for promoting the research and application of stainless steel composite steel plates.
The modulation of characteristics in AlGaN/GaN High electron mobility transistors (HEMTs) using multiple field plate technology
Authors: Tao Yujian , Sun Weihao , Zhong Rong
Published: August 2024

This study utilizes ATLAS-TCAD to investigate and propose a multiple electrode extension AlGaN/GaN HEMT. It explores different electrode extension structures combined with variations in plate dimensions to improve device operating capability and electrical breakdown. The study examines the electrical breakdown behavior, channel electric field distribution, output transfer characteristics, threshold frequency (Ft), and peak oscillation frequency (Fmax) under different electrode extension structures. The research demonstrates that the introduction of electrode extension structures can effectively modulate the distribution of channel electric fields. The electrode extension structure has minimal impact on the device’s transfer characteristics and output current. The dimension of the gate electrode extension significantly affects the reduction of the cutoff frequency, whereas the source electrode extension has almost no impact on the cutoff frequency. The introduction of the electrode extension structure leads to a decrease in the maximum oscillation frequency. As the dimension of the electrode extension increases, the decreasing trend slows down, with the gate electrode extension showing a greater reduction trend than the source terminal connected to the electrode extension. The proposed source-gate multiple electrode extension (SSG-FP) structure exhibits superior breakdown characteristics, with an improvement of approximately 750 V compared to the structure without electrode extensions. The optimized gate plate dimensions are 0.75 μm, the dimension of the primary source electrode extension is 3.1 μm, and the dimension of the secondary source electrode extension is 4.1 μm. The device exhibits a threshold frequency (Ft) of 17.86 GHz and a peak oscillation frequency (Fmax) of 58.6 GHz. These findings provide guidance for designing HEMT devices with electrode extension structures.
Study on the effect of carbonation treatment on concrete wash water
Authors: Lin Zhiyu , Lin Jiming
Published: August 2024

Wash water is a by-product of ready-mixed concrete production and currently lacks scientific recycling measures due to its high alkalinity and suspended solids content. To address this issue, this project investigated a novel approach utilizing a self-designed carbonation device. This device effectively carbonates the wash water, enabling its subsequent integration into cement mortar to assess its impact. A comprehensive analysis of the wash water was carried out using a variety of techniques. The findings from XRD, SEM-EDS, and ICP tests revealed that the carbonation triggers reactions in the hydration products of the wash water, leading to the formation of calcium carbonate, and TG analysis revealed a carbon sequestration rate of 16.11%. Notably, particle size analysis demonstrated that the calcium carbonate particles produced were nanosized, which could fill the tiny voids in the cement mortar, thereby enhancing its compressive strength. The strength test of the cement mortar showed that the compressive strength of the cement mortar mixed with carbonated wash water was improved, which increased by 13% compared with the control group.
Blue luminescence properties of Y2Sn2O7: Ce3+ transparent glass-ceramics
Authors: Xu Shengnan , Zhang Hongbo
Published: August 2024

Using the melt-crystallization technique, Y2Sn2O7: Ce3+ transparent glass-ceramics were prepared, and the crystalline phase was determined to be Y2Sn2O7 by XRD. It was discovered that the transparent glass-ceramics had a transmittance of up to 77.0% in the visible spectrum. The samples had the highest emission intensity at a concentration of 0.5% when excited at 340 nm. The Ce2O3 doped transparent glass-ceramics with the crystalline phase of Y2Sn2O7 can obtain better blue light emission, which is promising for applications in solid-state lighting and displays.
Effect of crosslinker molecular weight on the characteristics of thermoelectric ionogels
Authors: Dong Zixian , Tang Jihe , Chen Shanshan
Published: August 2024

The present study investigates an ionic thermoelectric gel with adjustable functionality through the manipulation of crosslinker molecular weight. The thermoelectric properties of 2-hydroxyethyl acrylate (2-HEA) ionogels, prepared using PEGDA200, PEGDA575, and PEGDA1000 as crosslinkers, were thoroughly examined. Furthermore, dynamic thermal mechanical analysis (DMA) and X-ray diffraction (XRD) techniques were employed to elucidate the underlying reasons for variations in the thermoelectric material properties resulting from changes in crosslinker molecular weight. Notably, the thermoelectric gel synthesized with PEGDA575 exhibited a remarkable thermal power output of 19.19 mV•K-1 along with a tensile capacity of 231%. Additionally, the developed ionic thermoelectric capacitor demonstrated an impressive energy density of 4.288 J•m−2, thereby showcasing its potential application in flexible low-grade heat energy recovery devices.