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Recently, Bazhanov and Sergeev have described an Ising-type integrable model which can be identified as a sinh-Gordon-type model with an infinite number of states but with a real parameter q. This model is the subject of Sklyanin's Functional Bethe Ansatz. We develop in this paper the whole technique of the FBA which includes: (1) Construction of eigenstates of an off-diagonal element of a monodromy matrix. The most important ingredients of these eigenstates are the Clebsh-Gordan coefficients of the corresponding representation. (2) Separately, we discuss the Clebsh-Gordan coefficients, as well as the Wigner's 6j symbols, in details. The later are rather well known in the theory of 3 D indices. Thus, the Sklyanin basis of the quantum separation of variables is constructed. The matrix elements of an eigenstate of the auxiliary transfer matrix in this basis are products of functions satisfying the Baxter equation. Such functions are called usually the Q-operators. We investigate the Baxter equation and Q-operators from two points of view. (3) In the model considered the most convenient Bethe-type variables are the zeros of a Wronskian of two well defined particular solutions of the Baxter equation. This approach works perfectly in the thermodynamic limit. We calculate the distribution of these roots in the thermodynamic limit, and so we reproduce in this way the partition function of the model. (4) The real parameter q, which is the standard quantum group parameter, plays the role of the absolute temperature in the model considered. Expansion with respect to q (tropical expansion) gives an alternative way to establish the structure of the eigenstates. In this way we classify the elementary excitations over the ground state. [ABSTRACT FROM AUTHOR]

This paper proposes a quick and straightforward technique for estimating the insertion loss (IL) of earplugs measured on an acoustical test fixture (ATF) using a commercial impedance tube. In this method, the earplug's acoustic properties (i.e., its transmission loss and the reflection coefficient of its medial surface) are determined from its transfer matrix measured using the three-microphones impedance tube method modified here for the current application. The IL is then estimated using a one-dimensional analytical model of open and occluded earcanals based on the wavefield decomposition theory. The method is evaluated numerically and experimentally from 50 Hz to 6.5 kHz. The numerical study allows for verifying the accuracy of the proposed approach in comparison to a simplified model of an ATF earcanal excited by normal incidence plane wave and diffuse field excitation. The experimental evaluation, which involves six earplugs (including five commercially available ones) representing various earplug families, demonstrates the accuracy of the estimation method, yielding results with a maximum difference of 3 dB compared to ATF measurements, on average, among the tested earplugs. [ABSTRACT FROM AUTHOR]

The compressive-equivalent source method (C-ESM) can reconstruct the sound field radiated by sparsely distributed sound sources with a reduced number of sensors. To ensure the performance of the C-ESM, the transfer matrix between the sensors and equivalent point sources should exhibit sufficient incoherence. Given that the configuration of the sensor array affects this incoherence condition, concern regarding the sensor array design would arise. To address such concern, this paper proposes a sensor array design approach. The primary objective of this approach is to minimize the mean coherence of the transfer matrix within the developed iterative framework, providing the incoherence condition required by the C-ESM. Subsequently, the designed sensor array is utilized by the C-ESM for the reconstructions. The effectiveness and practicality of the proposed approach are validated through numerical simulations and experiments. [ABSTRACT FROM AUTHOR]

We present an analysis of a three-layered structure used for both launching and detecting picosecond acoustic waves. To enhance the optical sensitivity to the acoustic disturbances, a cavity is designed, which acts as a Fabry–Perot interferometer. We use analytic modeling based on dual optical and acoustic transfer matrix formalism to analyze the coupled optical and acoustic wave propagation. Assuming a three-layer transducer made of an optical cavity sandwiched between two thin metallic layers, the model allows for mastering of the coupled optical and acoustic responses, which leads to an optimum design of the structure, and it highlights the various acoustic contributions to the reflectivity changes. The sensitivity of this three-layered structure to acoustic disturbances is compared to the numerical predictions we performed for the standard opto-acoustic transducer made of a single metallic layer. [ABSTRACT FROM AUTHOR]

The estimation of RxC ecological inference contingency tables from aggregate data is one of the most salient and challenging problems in the field of quantitative social sciences, with major solutions proposed from both the ecological regression and the mathematical programming frameworks. In recent decades, there has been a drive to find solutions stemming from the former, with the latter being less active. From the mathematical programming framework, this paper suggests a new direction for tackling this problem. For the first time in the literature, a procedure based on linear programming is proposed to attain estimates of local contingency tables. Based on this and the homogeneity hypothesis, we suggest two new ecological inference algorithms. These two new algorithms represent an important step forward in the ecological inference mathematical programming literature. In addition to generating estimates for local ecological inference contingency tables and amending the tendency to produce extreme transfer probability estimates previously observed in other mathematical programming procedures, these two new algorithms prove to be quite competitive and more accurate than the current linear programming baseline algorithm. Their accuracy is assessed using a unique dataset with almost 500 elections, where the real transfer matrices are known, and their sensitivity to assumptions and limitations are gauged through an extensive simulation study. The new algorithms place the linear programming approach once again in a prominent position in the ecological inference toolkit. Interested readers can use these new algorithms easily with the aid of the R package lphom. [ABSTRACT FROM AUTHOR]

In this paper, we conducted a detailed investigation on the evolution of a partially coherent generalized Hermite cosh-Gaussian beam (PCGHchGB) through a gradient-index medium. Analytical formula for a PCGHchGB propagating in the gradient-index medium is obtained based on ABCD transfer matrix and generalized diffraction integral formula. We discuss the periodic changes of the corresponding beam through the gradient-index medium by performing numerical examples. Our obtained results demonstrate that the gradient-index parameter of media and the initial beam parameters, such as the coherence width, beam waist width, decentered beam parameter, and beam orders, affect the evolution characteristics on the intensity distribution of the PCGHchGB in the gradient-index medium. The results of this work could be beneficial for applications in optical communication and nonlinear optics. [ABSTRACT FROM AUTHOR]

Over the past years, Surface Plasmon Resonance (SPR) has been used in various domains including medical diagnostics, chemical and biological sensing, and environmental monitoring. SPR-based biosensors have more advantages than other optical biosensors due to their rapid, label-free, and targeted detection capabilities. There have been challenges to designing SPR biosensors with enhanced performance and improved environmental adaptability, including considerations such as prism-metal bonding, biomolecule adhesion, and oxidation protection. This paper presents sensitivity and performance enhancement in an SPR biosensor based on Kretschmann configuration while using a low refractive index CaF2 glass prism, a zinc oxide (ZnO) layer, a gold-silver alloy (Au10Ag90), and a single layer of 2D graphene. Theoretical analysis shows that the use of a CaF2 prism and the alloy gives a good sensitivity of 280 ∘ / RIU . The sole addition of a ZnO layer improves this sensitivity to 320 ∘ / RIU . Further addition of a graphene layer to make the final proposed structure CaF2/ZnO/Au10Ag90/graphene/SM, improves sensitivity to 340 ∘ / RIU , giving a figure of merit value of 60.28 / RIU and a quality factor value of 102.48 / RIU . Despite supporting the SPR mode and enhancing sensitivity, ZnO improves prism-alloy bonding while graphene promises better biomolecule adhesion and improved oxidation protection. Overall, our proposed structure has better sensing performance compared to other designs in the literature. The high sensitivity makes our proposed biosensor suitable for the detection of tiny cancer bio-markers in body fluids, enabling early medical interventions. [ABSTRACT FROM AUTHOR]

In this article, we propose a novel surface plasmon resonance (SPR) sensor design with the combination of two-dimensional (2D) nanomaterials including copper, nickel, and graphene, along with a bonding layer of black phosphorous, to achieve significant enhancements in plasmonic performance. Theoretical analysis of the parameters has been performed using the Fresnel equations and Transfer Matrix method, based on the Kretschmann setup. For the CaF2 Prism/Cu/Ni/Graphene/BP/Sensing-Medium configuration, the optimized performance parameters include an angular sensitivity of 410°/RIU, a detection accuracy of 0.33789°, a figure of merit (FOM) of 138.538 RIU/deg, and a limit of detection of 2.439 for the medium being sensed at 633 nm. The utilization of both graphene and BP proves advantageous in increasing the SPR sensor's sensitivity since BP and graphene possess stronger adsorption energy, making it a more suitable candidate for actively binding biomolecules. The proposed device showcases considerable potential for the detection of large-sized molecules such as secretary vesicles and lysosomes. The numerical simulation has been performed in the COMSOL Multiphysics and MATLAB environment. [ABSTRACT FROM AUTHOR]

The non-reciprocal behavior of defect modes of a one-dimensional photonic crystal with two Weyl-semimetal-based defects is investigate by applying the transfer matrix method. The transmission spectrum of the structure exhibits two distinct defect modes. The study shows that these defect modes can be adjusted by altering the thickness of the Weyl semimetal layers and the modulus of the axial vector $ \vec{b} $ b → for both forward- and backward-impinging cases. The peak transmission and frequency of the defect modes are found to be dependent on the thickness of the Weyl semimetal layers, the magnitude of the axial vector $ \vec{b} $ b → , and the impinging direction of the incoming beam. Additionally, the quality factor of the defect modes changes with the thickness of the Weyl semimetal layers and the magnitude of the axial vector $ \vec{b} $ b → but is largely unaffected by reversing the impinging direction of the incoming beam. [ABSTRACT FROM AUTHOR]

The Shaanxi section is the central region of the Loess Plateau. Its unique wetland environment plays an indispensable role in regional ecological environment security. Clarifying the characteristics of wetland changes in the region is an important prerequisite for wetland management and protection. This study, based on the remote sensing data of the Shaanxi section of the Loess Plateau, analyzed the changes in the wetland area and type transfer in this region in 1980, 1990, 2000, 2010 and 2020 using the wetland dynamic degree model, the Markov transfer matrix, the landscape pattern index, and centroid analysis. The results showed that, from 1980 to 2020, the total wetland area and natural wetland area in the Shaanxi section of the Loess Plateau continued to shrink, decreasing by 79.35 km2 and 80.50 km2, respectively, while the artificial wetland area increased by 1.14 km2. Among the regions, Xi'an experienced the most significant reduction, with a total decrease of 83.04 km2 over 40 years, followed by Xianyang City, where the wetland area decreased by 6.50 km2. In contrast, the wetland areas of Yulin City, Weinan City, Yan'an City, Baoji City and Tongchuan City increased slightly. From 1980 to 2020, the change in the wetland types in the Shaanxi section of the Loess Plateau was mainly characterized by transfers between beach lands and river canals. River canals are the primary type of wetland in this region. The degree of fragmentation is the highest in reservoir potholes, while marshes have the largest clumpiness index. Over the same period, the centroid of the wetlands in the Shaanxi section of the Loess Plateau moved from south to north as a whole, although, between 1990 and 2000, the centroid position remained relatively stable. These results provide a theoretical basis and data support for wetland monitoring and protection in the Shaanxi section of the Loess Plateau and also provide a reference for the protection and sustainable development of other inland wetland resources in arid and semi-arid regions. [ABSTRACT FROM AUTHOR]

Taking the northern slope of the Tianshan Mountains (NSTM) in Xinjiang as the research area, this study analyzes the changes in the Production–Living–Ecological (P-L-E) Spaces and their Ecological Environmental Effects, providing a basis for optimizing the spatial pattern of the P-L-E Spaces and regional ecological environment protection in this area. Based on land use data and DEM data, various methods were used for analysis. These methods include the land use transfer matrix, ecological environment quality index, hot spot analysis, ecological contribution rate, and Terrain Position Index. The analysis focused on changes in the spatial pattern of the P-L-E Spaces from 1980 to 2020. It also examined the spatiotemporal distribution of ecological environment quality (EEQ). Furthermore, it explored the differentiation characteristics of EEQ in terrain gradients. The conclusions are as follows: (1) On the NSTM, Ecological Space decreased while Production and Living Space expanded. From 1980 to 2020, Agricultural Production Space increased rapidly. Industrial Production Space also saw rapid growth during this period. Urban Living Space expanded significantly from 1980 to 2020. Rural Living Space experienced steady growth over the same period. Forest Ecological Space initially increased but later decreased. Water Ecological Space showed an initial increase followed by a decrease from 1980 to 2020. (2) The EEQ first remained stable, declined slightly from 2000 to 2010, improved significantly, and then deteriorated from 2010 to 2020. The distribution of EEQ exhibits a "high in the northwest, low in the southeast" pattern. EEQ hot spots on the NSTM are concentrated in the Tianshan Mountains, with clustering increasing in both northern and southern areas. Cold spots are found in the southern, eastern, and northern NSTMs, with aggregation strengthening in the south and north and slightly weakening in the east. Hot spots of EEQ changes on the NSTM show stable distribution, with stronger aggregation from 2000 to 2020. However, aggregation of cold spots has gradually weakened, yet noticeable aggregation persists throughout the study period. (3) There is a significant gradient difference in EEQ distribution. Higher terrain gradients have a higher EEQ. From 1980 to 2020, lower terrain gradients saw improvement, while higher gradients experienced deterioration. The EEQ on the NSTM has declined, showing significant spatial differences, with better quality on the northern side than the southern side. Future efforts should focus on restoring the environment at lower gradients, mitigating deterioration at higher gradients, and enhancing water conservation in the Tianshan Mountains. [ABSTRACT FROM AUTHOR]

Analysis of the driving mechanisms of wetland change can help identify spatial differences in the mechanisms affecting various elements, enabling a more scientific approach to the conservation and utilization of wetlands. This study investigated the impacts of natural and anthropogenic factors on the spatiotemporal evolution of the Altay and Greater and Lesser Khingan Mountains areas using Landsat satellite image data from 1980 to 2018 and fieldwork data from 2019 to 2020. A transfer matrix, correlation analysis, and dynamic characteristics were applied to calculate and analyze the transformation types and areas of wetland resources across all consecutive periods. Finally, the dominant factors influencing the spatiotemporal evolution of the wetland were explored and revealed using the drought index (Standardized Precipitation Index, SPEI) and statistical almanacs. The results showed: (1) From 1980 to 2018, the wetlands area in the Altay Mountains exhibited a decreasing trend, whereas the wetlands area in the Greater and Lesser Khingan Mountains showed an increasing trend. The primary type of wetland transfer in the Altay Mountains was grassland, whereas in the Greater and Lesser Khingan Mountains regions, the primary types of wetland transfer were grassland and forestland. The wetlands area transferred out of the Altay Mountain region was larger than the area of wetland types transferred into during 2010–2018, whereas the wetland areas of the Greater and Lesser Khingan Mountain areas showed the opposite trend. (2) From 1980 to 2018, the wetland ecosystem types in the Altay Mountains exhibited the highest dynamic and conversion degrees of the channels. Similarly, the mountain areas of the Greater Khingan Mountains showed the highest dynamic and conversion degrees of marshes and channels among the wetland types. In addition, the mountainous areas of the Lesser Khingan Mountains showed the highest dynamic and conversion degrees for reservoirs and rivers. (3) Natural driving factor analysis revealed that the SPEI values in the Altay Mountains and the Greater and Lesser Khingan Mountains areas exhibited an increasing trend, indicating that the climate has been warm and humid over the past 30 years and that the expansion of cropland and human-made wetland areas has been significantly influenced by human activities. Therefore, the wetland areas of the Greater and Lesser Khingan Mountains in the northeast are strongly influenced by human activities, whereas the wetland in the Altay Mountains in the northwest is strongly influenced by the climate. [ABSTRACT FROM AUTHOR]

The transmission spectrum of a twin-waveguide cavity is systematically analyzed based on coupled mode theory, using the transfer matrix method (TMM). The results show that the traveling-wave transmission spectra of the twin-waveguide cavity is entirely determined by the coherent coupling effect involving the parameters of the effective refractive indices of the upper and lower waveguides, the coupling length Lc, and the ratio of the cavity length L to the coupling length (L/Lc). Filters with single, double, or triple-notch filtering could be obtained by choosing an appropriate L/Lc value. When the facet reflection is taken into consideration, the traveling-wave transmission spectrum is modified by the Fabry––Perot (FP) resonance, making it a standing-wave transmission spectrum. As a result, resonance splitting has been observed in the transmission spectrum of twin-waveguide resonators with high facet reflectivity. Further analysis shows that such an abnormal resonance phenomenon can be attributed to the destructive interference between the two FP resonance modes of the upper and lower waveguide through coherent coupling. In addition, narrow bandwidth amplification has also been observed through asymmetric facet reflections. Undoubtedly, all these unique spectral characteristics should be beneficial to the twin-waveguide cavity, achieving many more functions and being widely used in photonic integration circuits (PICs). [ABSTRACT FROM AUTHOR]

This work investigates the interaction between water waves and multiple ice shelf fragments in front of a semi-infinite ice sheet. The hydrodynamics are modelled using shallow water wave theory and the ice shelf vibration is modelled using Euler–Bernoulli beam theory. The ensuing multiple scattering problem is solved in the frequency domain using the transfer matrix method. The appropriate conservation of energy identity is derived in order to validate our numerical calculations. The transient scattering problem for incident wave packets is constructed from the frequency domain solutions. By incorporating multiple scattering, this paper extends previous models that have only considered a continuous semi-infinite ice shelf. This paper serves as a fundamental step towards developing a comprehensive model to simulate the breakup of ice shelves. [ABSTRACT FROM AUTHOR]

We used the transfer matrix method to investigate the conditions supporting the existence of directional bulk waves in a two-dimensional (2D) phononic crystal. The 2D crystal was a square lattice of unit cells composed of rectangular subunits constituted of two different isotropic continuous media. We established the conditions on the geometry of the phononic crystal and its constitutive media for the emergence of waves, which, for the same handedness, exhibited a non-zero amplitude in one direction within the crystal's 2D Brillouin zone and zero amplitude in the opposite direction. Due to time-reversal symmetry, the crystal supported propagation in the reverse direction for the opposite handedness. These features may enable robust directional propagation of bulk acoustic waves and topological acoustic technology. [ABSTRACT FROM AUTHOR]

The enhancement of regional comprehensive development ability is significantly impacted by the study on the implementation effect of regional integration strategies. The integration strategy's impact on urban development during COVID-19 in the Yangtze River Delta(YRD) is unclear. According to prior industrial transfer theory, Hefei, Anhui's capital, is difficult to transfer industries, and other YRD cities push industry integration in Anhui. This study employs the theory of economic and land resource use to examine the resilience of the industrial economy during an epidemic by using industrial land as a representation of industrial economic development. The three cities in Anhui—Wuhu, Maanshan, and Chuzhou (Wu-ma-Chu) were selected as the research area. The study employed the UNet deep learning method to detect the land use types in Wu-ma-Chu. The land transfer matrix and the standard deviation ellipse were utilised to research the alterations in industrial land use and the spatial distribution of industrial output value, respectively. The results showed that the industrial land in Machu continued to grow during the outbreak, highlighting the resilience of the region's industrial economy. During 2019–2022, the elliptical ring of industrial output value is distributed in Nanjing, revealing the radiating role of Nanjing in integrating into the integration of the YRD. This confirms China's YRD integration strategy, strengthens regional economic resilience, and encourages coordinated regional economic development. [ABSTRACT FROM AUTHOR]

The small-signal stability of high voltage direct current (HVDC)-connected wind farms (WFs) is a challenging issue in modern power systems. The relative stability, i.e., the stability margin, of such a typical multiple-input multiple-output (MIMO) system is quite difficult to be quantified. This paper evaluates the relative stability of HVDC-connected WFs using a new stability index based on the ν-gap metric. We first develop a MIMO model represented by a transfer function matrix of the HVDC-connected WFs. Then, a new stability index, i.e., the robust stability margin, based on the ν-gap metric is proposed to quantify the relative stability of such a MIMO system. Finally, we propose a method to compute the stable region of control parameters based on the corresponding stability criterion of ν-gap metric. Case studies are given to demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

AbstractTo achieve multiple low-frequency topological interface modes (TIMs) while maintaining lightweight and load-bearing capacities in metamaterial beams, we propose novel topological beams equipped with double quasi-zero-stiffness (QZS) resonators. Following the introduction of the negative stiffness (NS) mechanism, we derived the dispersion relations of the topological beams with double QZS resonators using the transfer matrix method (TMM), and performed comparative and parametric analyses of stiffness ratio on folded Dirac cones (DCs) and locally resonant band gaps (LRBGs). Thanks to the NS mechanism and the double degrees of freedom (DOFs) in the QZS resonators, we can realize double low-frequency DCs (< 500 Hz) in metamaterial beams. It is notable that adjusting the stiffness of oblique springs can tune the resonators’ effective stiffness, implying that we can custom the frequency of DCs and LRBGs by adjusting the QZS resonator. By altering the distance between two QZS resonators, we obtain two topologically distinct unit cells. Transmission simulations confirm the presence of multiple low-frequency TIMs at the interface between these two domains. We also find that the effect of mass and geometric defects at various positions on TIMs is minimal. The proposed metamaterial beams could inspire innovative low-frequency vibration energy harvesters and lightweight topological devices. [ABSTRACT FROM AUTHOR]

Due to the advantages of Laplace domain in both time and frequency domains, the dynamic analysis and control tools in engineering software like MATLAB and Python have been designed based on it. Dynamic analysis of structures requires determination of the overall transfer matrix, which is obtained by multiplying the structure's transfer matrix (TM) with the load TM. With the input vector of unit intensity white-noise processes and the overall TM, the structural responses can be obtained. Furthermore, having the load TM is crucial for implementation of active control systems. In this article, the TM of along-wind loads was estimated for a tall building using the proper orthogonal decomposition (POD) method and the genetic algorithm (GA). To evaluate the effectiveness of the proposed approach, an example of a tall building was provided. The wind load cross-power spectral matrix (XPSD) was decomposed using POD technique, followed by the truncation of higher loading modes. Subsequently, the loading TM was derived by estimating the target non-linear functions with linear transfer functions through GA technique. Then, the responses of the structure were computed using the loading TM. The results demonstrated the efficacy of the proposed method in acquiring the loading TM and predicting wind-induced responses. [ABSTRACT FROM AUTHOR]

Liquid crystal polymers (LCP) and polytetrafluoroethylene (PTFE) were in situ fibrillated to produce polyethylene terephthalate (PET)/LCP/PTFE composites using a simple and scalable extrusion drawing techniques. The PET/LCP/PTFE composites included high-aspect-ratio PTFE fibrils and rod-like LCP fibrils. The simultaneous in situ fibrillation of LCP and PTFE exerted synergistic effects on crystalline behaviour and viscosity of PET, especially for mechanical properties of PET and its foam. The tensile strength of PET/LCP/PTFE composites and impact strength representing improvements of 34% and 62% over those of PET. The improved mechanical properties can be attributed to the simultaneous abundance of orienting rod-like rigid LCP fibrils and tangling flexible PTFE fibrils in the PET matrix, which contributed to stress transfer from matrix to fibrils. A simultaneously in situ fibrillated PET/LCP/PTFE composite foam was fabricated using a batch foaming system with supercritical CO2 as blowing agent. The cell diameter of this foam decreased by 23% over that of standard PET foam, while its cell density increased twofold. The smaller cell diameter of PET/LCP/PTFE foam and superior mechanical properties of PET matrix collectively led to the good mechanical properties of PET/LCP/PTFE foam. Specifically, the compressive strength of the PET/LCP/PTFE foam represents a 35% increase over that of PET foam. [ABSTRACT FROM AUTHOR]

A novel metamaterial periodic multi-span beam with elastic supports and local resonators is designed and studied. The vibration characteristics of the designed metamaterial multi-span beam structure are investigated by the spectral element method (SEM) combined with the transfer matrix method (TMM). The accuracy and feasibility of the theoretical methods are validated by the finite element method (FEM) and vibration experiment. It is demonstrated that the metamaterial periodic multi-span beam with elastic supports can produce local resonance bandgaps in the low-frequency regions and Bragg bandgaps in the middle- and high-frequency regions. For some support stiffnesses, the amplitudes and widths of the bandgaps for the proposed structure are larger than those of the metamaterial multi-span beam with simply supported boundaries. Thus, the positions and ranges of the Bragg bandgaps can be adjusted by changing the stiffness of the elastic supports so as to improve the vibration reduction performance of the structure. [ABSTRACT FROM AUTHOR]

In recent years, much attention has been paid to integrated photonics devices based on nonlinear media. A generalization of the transfer matrix method to problems in plane-parallel layered media with quadratic and cubic nonlinearity is proposed. The incident radiation can be either a monochromatic wave or a non-monochromatic pulse. Previously, such problems could only be solved using grid methods. The proposed approaches significantly expand the range of applicability of matrix methods and are drastically superior in efficiency to the well-known grid methods. [ABSTRACT FROM AUTHOR]

We report a reflection based multimode fiber surface plasmon resonance (SPR) sensor utilizing a high index silicon layer between silver metal and sensing medium layer. Theoretical studies have been carried out to optimize the suitable width of material layer to sense refractive index (RI) of the analyte surrounding the optical fiber sensing region using the transfer matrix method. The RI sensitivity of the proposed SPR sensor has been experimentally verified to reach 4774 nm/RIU with figure of merit of 36.07 and resolution of 6.28 × 10−5at 1.38 RI. Furthermore, the large thermo-optic coefficient and thermal expansion coefficient of the silicon layer has enhanced the experimental temperature sensitivity of the SPR sensor to 1.76 nm/°C. [ABSTRACT FROM AUTHOR]

ZrP2O7 ceramics exhibit poor mechanical properties after firing, as a major drawback. In this study, ZrP2O7 matrix composites reinforced with high silica fibers were prepared through pressureless sintering by varying the content and length‐to‐diameter ratio of the high silica fibers added to ZrP2O7 powder. After heat treatment at 1200‒1300°C, the room temperature flexural strength of the ZrP2O7 matrix composites with different amounts high silica fibers having different aspect ratios was 14.9‒45.2 MPa, the bulk density was 1.90‒3.03 g·cm−3, the apparent porosity was 2.37%‒39.39%, and the room temperature thermal conductivity was.47‒.95 W/(m·K). With an increase in the heat‐treatment temperature, driven by sintering and fiber crystallization, strength of the interfacial layer between the fibers and the matrix inside the ZrP2O7 matrix composites decreased and then increased. The transfer and blocking effects of the interface enabled effective transfer of the stress of the matrix to the fiber‐reinforced phase and prevented crack extension. The problem of inherent crystallization affecting high silica fibers at high temperatures was relieved by the ZrP2O7 ceramic matrix composites. [ABSTRACT FROM AUTHOR]

Truck suspension is a vital component supporting the weight of the vehicle body and plays an important role in transferring wheel load and isolating external vibration. The uneven load distribution between the middle and rear wheels of a tri-axle heavy truck will directly affect the driving stability and safety of the vehicle. To enhance the truck's wheel load distribution performance and ride comfort, this paper proposes a new coupling suspension system, including an anti-synchronous middle and rear axle hydraulically interconnected suspension (MR-HIS) and the front axle conventional independent suspension (CIS). Considering the load-bearing characteristics of the middle and rear wheels of the tri-axle heavy truck, a five-degree-of-freedom (5-DOF) half-vehicle model of the truck equipped with MR-HIS is constructed. Further, the dynamics equations of the mechanical-hydraulic coupling system are established according to the impedance transfer matrix method and mechanical-hydraulic boundary conditions, and the truck body motion modes are completely decoupled. The modal analysis demonstrates that compared with CIS the proposed MR-HIS system can reduce the body bounce modal stiffness, increase the modal damping ratio, and enhance the dynamic coupling performance of middle and rear wheels. Subsequently, the frequency response analysis is adopted to evaluate the load distribution and vibration isolation performance of the MR-HIS. The comparison analysis results indicate that the proposed MR-HIS system significantly improves the load balance distribution between the middle and rear wheels and suppresses the load transfer to the front wheel, thus the handling stability of the truck is improved. Meanwhile, the body vibration frequency response analysis shows that the MR-HIS can effectively isolate external vibration and improve driving comfort of the tri-axle heavy truck. [ABSTRACT FROM AUTHOR]

Vibration characteristic is an important factor affecting the motion of rocket in the launcher and its firing performance. In this paper, a rocket-launcher coupling dynamics model is proposed by applying the transfer matrix method for multibody systems. Considering manufacturing error and nonlinear contact force, the dynamics equations of the rocket-launcher coupling system during the whole process of firing are deduced. Combined with the dynamics model and equations, a dynamics simulation system is developed with uncertain parameters. The uncertain parameter description scheme and probability sampling scheme are proposed to obtain dynamics characteristic and firing performance of the system. The relevant tests are carried out to verify simulation results. Then, the factors affecting the firing performance are discussed. In view of the analysis results, the influence weight of initial disturbance on firing precision is 85% under the condition of full-loading continuous firing, and the swing angular velocity of rocket at muzzle is the main influence factor. [ABSTRACT FROM AUTHOR]

This work aims to investigate the sensitivity to disturbance for the bidirectional multiple-vehicle following (BDM) V2V vehicular platoon. A disturbance term is introduced into the control input, and a closed-loop equation about the spacing error is derived. The sensitivity of error propagation to disturbance is defined based on the error transfer function matrix, and the sensitivities to external disturbance and the motion of the leading vehicle have been analyzed in the frequency domain and validated by model simulations. The affecting factors, including communication topology, control gains, and weights for acceleration communication, have been analyzed. It is revealed that the communication topology plays a significant role in reducing the sensitivities of error propagation to disturbance, and the effects on the sensitivity to external disturbance and the motion of the leading vehicle are roughly opposite. The spacing control gain plays a more important role in reducing the sensitivity compared with the speed following control gain, especially for the sensitivity to external disturbance. More weight should be distributed to vehicles that are relatively nearer to the current vehicle for the purpose of reducing the sensitivities. [ABSTRACT FROM AUTHOR]

Drawing upon the fundamental principles of mixture continuum and thermodynamics, a planar P wave incident model for layered unsaturated soil is formulated. Employing the Helmholtz vector decomposition principle, the wave field within the layered unsaturated soil is analyzed using the transfer matrix method, accounting for the influence of thermal effects. A conversion matrix for the wave amplitude coefficients in layered unsaturated soil layers is derived in the bedrock-layered unsaturated soil system. An analytical solution is obtained for the seismic response in layered unsaturated soil under the action of thermal effect. Numerical calculations are employed to analyze the effect of thermal physical parameters, including temperature and solid relative heat, on ground motion within layered unsaturated soil. A substantial disparity exists in the magnification factors for surface displacement obtained under the modeling of the two theories with thermal effect and thermo-free effects, and the displacement amplifying coefficient of the layered unsaturated foundation under thermal effect is different from that of the homogeneous unsaturated soil foundation. The influence of solid relative heat on the displacement amplifying coefficient is primarily determined by the thermal stability of the soil, while the impact of the thermal expansion coefficient on this factor is intricately linked to the magnitude of solid relative heat within the soil. As the saturation grows, the horizontal and vertical displacement amplifying coefficient rises continuously. The orders of arrangement of soft and hard soil layers, temperature, and frequency have noteworthy effects on the displacement amplifying coefficient. [ABSTRACT FROM AUTHOR]

In this paper, an effective numerical Bernstein polynomials operational matrix is exploited to study the nonlinear forced vibration of fractional viscoelastic curved beam with viscoelastic nonlinear boundary conditions, for the first time. The Caputo fractional derivative is employed to incorporate viscoelastic material having nonlinear behavior. Based on Euler–Bernoulli beam theory and von Kármán geometric nonlinearity, the governing equation of viscoelastic curved beam which is a nonlinear integro-partial fractional differential equation is introduced. Based on the collocation method of Bernstein polynomials approximation, the generalized integer-order operational matrices of differentiation and integration as well as fractional-order operational matrix of differentiation are derived. Using Bernstein polynomials operational matrices (BPOM), the nonlinear static problem is discretized; then, it is solved via Newton's method. To compute the linear vibration mode, the linear vibration problem is discretized via BPOM and it is solved as a linear eigenvalue problem. Discretized by the Galerkin approximation, the fractional-order nonlinear integro-partial differential equation is transformed into a nonlinear fractional-order duffing-type equation. The fractional-order duffing equation is discretized using BPOM resulting nonlinear eigenvalue problem, which can be easily solved by pseudo-arc length continuation algorithm. The effects of the Caputo fractional derivative order, foundation parameters, amplitude of initial curvature, viscoelastic parameters and amplitude of excitation force on the nonlinear forced vibration of the viscoelastic beam are investigated through a detailed parametric study. The proposed procedure is supportive in the analysis and design of curved viscoelastic structure with non-classical viscoelastic boundary conditions under the dynamic mechanical loads. [ABSTRACT FROM AUTHOR]

Purpose: To present a paraxial method to estimate the influence of variations in ocular biometry on changes in refractive error (S) at a population level and apply this method to literature data. Methods: Error propagation was applied to two methods of eye modelling, referred to as the simple method and the matrix method. The simple method defines S as the difference between the axial power and the whole‐eye power, while the matrix method uses more accurate ray transfer matrices. These methods were applied to literature data, containing the mean ocular biometry data from the SyntEyes model, as well as populations of premature infants with or without retinopathy, full‐term infants, school children and healthy and diabetic adults. Results: Applying these equations to 1000 SyntEyes showed that changes in axial length provided the most important contribution to the variations in refractive error (57%–64%), followed by lens power/gradient index power (16%–31%) and the anterior corneal radius of curvature (10%–13%). All other components of the eye contributed <4%. For young children, the largest contributions were made by variations in axial length, lens and corneal power for the simple method (67%, 23% and 8%, respectively) and by variations in axial length, gradient lens power and anterior corneal curvature for the matrix method (55%, 21% and 14%, respectively). During myopisation, the influence of variations in axial length increased from 54.5% to 73.4%, while changes in corneal power decreased from 9.82% to 6.32%. Similarly, for the other data sets, the largest contribution was related to axial length. Conclusions: This analysis confirms that the changes in ocular refraction were mostly associated with variations in axial length, lens and corneal power. The relative contributions of the latter two varied, depending on the particular population. [ABSTRACT FROM AUTHOR]

Short-wave communication, operating within the frequency range of 3–30 MHz, is extensively employed for long-distance communication because of its extended propagation range and robustness. The ionosphere undergoes complex transformations when influenced by the geomagnetic field, evolving into an uneven and anisotropic electromagnetic medium. This complex property makes the transmission of electromagnetic fields within the ionosphere extremely complex, posing significant challenges for accurately evaluating electromagnetic scattering phenomena. To address the aforementioned challenges, this paper proposes a new method for calculating short-wave ionospheric scattering based on a complex anisotropic multilayer medium transmission matrix. Firstly, by utilizing the characteristic changes of ionospheric electron density with height, the ionization layer is divided into multiple horizontal thin layers, each with an approximately uniform electron density, forming a multilayer horizontal anisotropic structure. Subsequently, the scattering characteristics of electromagnetic waves in the ionosphere were calculated using the transmission matrix approach. The results calculated using this method are consistent with actual measurement values and superior to traditional short-wave ionospheric transmission calculation methods. [ABSTRACT FROM AUTHOR]

This study employed a data-driven approach involving the creation and training of a deep neural network model to swiftly compute spectral data for nano-photonic devices. Initially, the transfer matrix method was utilized to compute transmission and reflection spectra for one million layered materials composed of SiO2/Si3N4. These spectra were then used as the training data for the deep neural network. Remarkably, despite using a training set that represented just one billionth of all possible samples within the design space, the resulting model displayed exceptional accuracy. More than 99.71% of the predictions demonstrated a standard error below 1%. This method represents a significant advancement over traditional design approaches, as it drastically reduces the complexity for designers. Moreover, the deep neural network model is less than 1 megabyte in size, making it easy to integrate into micro-optoelectronic devices. [ABSTRACT FROM AUTHOR]

The local resonance phononic crystals have advantages in obtaining low frequency band gaps, while the local resonance band gap obtained by traditional structures is inconvenient for engineering applications due to its narrow width. In this manuscript, a theoretical framework for the design and analysis of the Outward Hierarchical Local Resonance Euler Beam (OHLREB) structure has been introduced, which considers the foundational constraints, non-rigid interfaces, and the damping characteristics of the coating layer, leading to a significant enhancement in the low-frequency band gap properties. To analyze the band gap properties of OHLREB, the improved transfer matrix method is derived to obtain the band structure, and the spectral element method is applied to calculate the frequency response function. Furthermore, the band gap mechanism is investigated based on modal analysis of primitive cell and the time domain analysis and energy period analysis of OHLREB structure. The results indicate that improved transfer matrix method can offer a more streamlined and transparent process for solving eigenvalues and determining attenuation intervals, which can be used for the theoretical analysis of band gap regulation. It overcomes the constraints of traditional approaches by reducing the computational burden associated with matrix inversions and multiplications, thereby enhancing the efficiency of band gap analysis. The band gap mechanism investigation demonstrates that the energy conversion period is considerably longer than the load period in band gap frequency, leading to multiple conversions of the kinetic energy of the scatterer and the elastic strain energy of the coating layer within a single energy cycle, which leads to the strong local resonance and results in the attenuation of elastic waves in the band gap range. The parameter analysis is carried out to reveal the regulation laws of band gap, the results reveal that band gap intervals and attenuation efficiency can be optimized to obtain low frequency and broadband by configurating properly the control parameters, such as the matrix reaction modulus, interface stiffness, the coating layer damping, and the scatterer combination. Based on the analysis results, the design and control directions for obtaining the wider and lower frequency band gaps are given. The conclusions obtained in this manuscript can provide theoretical support and practical design perspectives for multi-frequency vibration control field. [ABSTRACT FROM AUTHOR]

An optical biosensor designed using a Nanocomposite/Defect/Nanocomposite multilayer 1D photonic crystal is proposed for malaria diagnosis. The defect layer represents blood samples corresponding to various stages of malaria. Employing the Transmission Matrix Method (TMM), we analyse the impact of two kind of nanocomposite (NC) layers: silver-doped TiO2 and silver-doped SiO2. Comparative analyses involving varying thickness and fill factor of NC layers indicate increased sensitivity with higher fill factors and thickness, albeit with a decrease in transmission. Further, we explore the influence of incident angle (TM & TE mode) on sensing performance, revealing enhanced sensitivity at higher angles. The maximum sensitivity peaks are reported to be 1074 nm/RIU and 1064 nm/RIU for the mentioned NC layer cases. This biosensor promises enhanced sensitivity and potential for advanced malaria diagnostics. [ABSTRACT FROM AUTHOR]

Studying the spatiotemporal evolution and driving forces behind construction land amidst the intricate ecological and geological setting on the eastern edge of the Qinghai–Tibet Plateau offers invaluable insights for local sustainable development in a landscape transition zone and ecologically fragile area. Using construction land data from four phases, spanning 1990 to 2020, in Mianning County, this study employs methodologies like the Landscape Expansion Index (LEI) and land use transfer matrix to delineate the spatiotemporal evolution characteristics of construction land. A comprehensive set of 12 influencing factors across five categories—geomorphology, geological activity, climate, river and vegetation environment, and social economy—were examined. The Geographically Weighted Regression (GWR) model was then employed to decipher the spatial distribution pattern of construction land in 1990 and 2020, shedding light on the driving mechanisms behind its changes over the three decades. The research reveals distinct patterns of construction land distribution and evolution in Mianning County, shaped by the ecological and geological landscape. Notably, the Anning River wide valley exhibits a concentrated and contiguous development mode, while the Yalong River deep valley showcases a decentralized development pattern, and the Dadu River basin manifests an aggregation development mode centered around high mountain lakes. Over the study period, all three river basins witnessed varying degrees of construction land expansion, transitioning from quantitative expansion to qualitative enhancement. Edge expansion predominantly characterizes the expansion mode, complemented by leapfrog and infilling modes, accompanied by conversions from cropland and forest land to construction land. An analysis of the spatial pattern and drivers of construction land change highlights human-induced factors dominating the Anning River Basin, contrasting with natural factors prevailing in the Yalong River Basin and the Dadu River Basin. Future efforts should prioritize climate change considerations and environmental capacity, aiming for an ecologically resilient spatial pattern of construction land. [ABSTRACT FROM AUTHOR]

This study meticulously investigates landscape alterations within the Mu Us Sandy Land, a critical region for desertification control in China. The research dissects the dynamic characteristics and inter-conversion of landscape elements across eleven distinct periods by employing multi-source remote sensing imagery spanning 1963 to 2020, alongside visual interpretation, random forest classification, and the desertification difference index (DDI). The analysis uncovers significant landscape transformations within the Mu Us Sandy Land over the past six decades, following a precise chronological sequence. A pivotal shift occurred around 1986, characterized by opposing trends within fixed and shifting sandy land. The earlier stage (pre-1986) witnessed a substantial decrease (66.9%) in the fixed sandy land area, accompanied by a corresponding rise (38.7%) in shifting sandy land. Conversely, the later stage (post-1986) era exhibited a remarkable increase (309.7%) in fixed sandy land, alongside a significant decline (78.9%) in shifting sand land coverage. This study identifies two stages of landscape transformation: a pre-1986 phase dominated by the conversion of fixed sandy land to semi-fixed sandy land and a post-1986 reversal toward shifting sand land into fixed sandy land. These sequential transformations have shaped the landscape pattern alterations observed in the Mu Us Sandy Land since 1963. The dramatic landscape improvements observed after 1986 can be primarily attributed to the implementation and continued investment in large-scale ecological restoration projects. This study's findings, which reveal the intricate landscape dynamics and their implications for ecosystem management, provide a scientific foundation for refining and formulating comprehensive strategies to control desertification and manage the Mu Us Sandy Land's unique ecosystem. [ABSTRACT FROM AUTHOR]

Precast slab bridges are an attractive option for short- to medium-span bridges; however, the presence of longitudinal joints and concrete overlays adds great complexity to the transverse load distribution (TLD) analysis. Currently, one of the most commonly used methods for simplified analysis relies on the semiempirical formulas provided in AASHTO LRFD Bridge Design Specifications; yet, these formulas have certain limitations in their applicability. This study presents an algorithm based on the transfer matrix method (TMM) to determine the TLD of precast slab bridges. A connection model utilizing shear-and-torsion spring hinges (STSHs) is proposed to simulate the structural behavior of shear keys and the overlay of precast slab bridges in TLD calculations. The transfer matrices and transfer equations between slabs and between joints are established. The TLD for slabs is then computed by introducing boundary conditions and solving transfer equations. In addition, the finite-element method (FEM), along with the existing field tests of two different bridges, is used to verify the accuracy and validity of the proposed method. The study concludes that the TMM shows high algorithmic efficiency compared to the FEM modeling procedure and better precision and applicability than the semiempirical equations provided in AASHTO LRFD. Moreover, extended parametric studies are conducted on the effects of the thickness of concrete overlay and the relative flexibility coefficients of slabs on the TLD of bridges. [ABSTRACT FROM AUTHOR]

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The mainstream basin of the Tarim River serves as a vital ecological security barrier that prevents the merging and expansion of deserts and an important strategic corridor directly linking Qinghai and Xinjiang. With society's development and climate change, ecological issues such as river interruption, vegetation degradation, and land desertification in the basin have notably intensified, and the ecological security is facing a critical test. Exploring the characteristics of landscape changes and their driving factors within the basin is crucial in improving the ecological environment system's management. Based on land use data from 1980 to 2020, this study analyzed the characteristics of the spatiotemporal changes and pattern evolution of the landscape through a landscape transfer matrix and landscape pattern indices. It further revealed the impact factors of the landscape pattern through canonical correspondence analysis. The results showed that (1) in 1980–2020, the areas of desert, forest, farmland, and settlement landscapes increased, while the area of grassland landscape decreased, and the water landscape showed an "increasing–decreasing–recovery" pattern. The landscape transition types mainly included the transition from grassland to desert; mutual transitions among farmland, grassland, and forests; mutual transitions between water and grassland; and the transition from farmland to settlements. (2) The overall landscape pattern demonstrated increased fragmentation, shape complexity, and evenness with decreased aggregation. Furthermore, different landscapes exhibited distinct characteristics of landscape pattern changes; for instance, grassland landscape showed severe fragmentation, while desert landscape displayed the strongest dominance. (3) The landscape pattern was a result of the combined impact of natural and human factors, with the soil thickness (SOT), road density (ROD), annual actual evapotranspiration (AAE), population density (POD), and mean annual temperature (MAT) exhibiting significant influences. Specifically, the settlement and farmland landscapes were mainly influenced by the mean annual relative humidity (MAH), POD, GDP density (GDP), and distance to artificial water (DAW); the forest, grassland, and water landscapes were mainly influenced by the SOT, soil organic matter content (SOM), AAE, ROD, elevation (ELE), MAT, slope (SLP), and distance to natural water (DNW); and the desert landscape was mainly influenced by the DAW, DNW, SLP, AAE, SOT, SOM, and ROD. These findings can provide a scientific reference for landscape management and restoration, as well as sustainable social and economic development, in the mainstream basin of the Tarim River. [ABSTRACT FROM AUTHOR]

Background and objectives: Land use and land cover change (LULCC) directly affects the human living environment and economic society by influencing ecosystem services. This study explores the complex relationship between LULCC and ecosystem services in the Dongting Lake region of China. Methods: The analysis incorporates the transfer matrix analysis of LULCC, ecosystem service value (ESV) accounting, Mann-Kendall mutation test, gray correlation, and path analysis. This study explored the spatial and temporal characteristics of LULCC and ecosystem services and revealed the comprehensive impacts of LULCC on ecosystem services from the perspective of factor interactions. Findings: The findings reveal that open water (OW) area and farmable land are the dominant land use types transferring in and out of the study area, with significant interconversion observed among open water area, wetland (WL), arable land (AL), and forest land (FL). Water conservation, waste disposal, climate regulation, and biodiversity conservation emerge as the most crucial ecosystem services in the study area. The study identifies consistent patterns of abrupt changes in LULCC and ESV across six analyzed time periods. Forest land exhibits the most substantial direct influence on climate regulation, gas exchange, soil formation and protection, conservation of biodiversity, rawmaterials, and recreation and leisure. Additionally, forest land, wetland, arable land, and openwater area contribute significantly to the total ESV, with forest land being the dominant factor influencing the spatial differentiation of ecosystem services in the Dongting Lake region. Conclusion: The research reveals the consistency of ecosystem services and LULCC trends in the Dongting Lake area. LULCC is a complex process influenced by multiple factors, in which the conversion between ecological and nonecological land use has a significant impact, and the complex coupling and coordination among LULCC drivers together influence ecosystem services. Furthermore, LULCC alters the structure and scale of ecosystems, resulting in alterations in the ESV. [ABSTRACT FROM AUTHOR]

This study aims to enhance the accuracy and reliability of low-cost sensors for measuring fine dust concentrations. Sensors used to measure the concentration of fine dust particles are expensive and the transfer function that adjusts the number of dust particles to dust concentration is complex and not well-known. Previous research has utilized singular-value-decomposition to obtain effective transfer matrices, but noise information measured by low-cost sensors is also transmitted. In this study, by using long short-term memory as filter for noise suppression, we effectively mimicking the data flow measured by expensive reference device. Experimental results show that existing filters suppress noise by approximately 20%, while the proposed long short-term memory filter achieves around 50% noise suppression. Furthermore, in discontinuous operations, five times repetitive learning of initial data reduced the relative error in initial data to within 10%, significantly reducing the initial delay. [ABSTRACT FROM AUTHOR]

The poverty-stricken counties on the Qinghai-Tibet Plateau are characterized by ecological vulnerability and ecological degradation, which are vulnerable to economic development and human activities, thereby leading to frequent alterations of Land carbon sink changes. Therefore, it is of great significance to study the changes of land carbon sink capacity during the process of eradication of extreme poverty in poverty-stricken counties. Using remote sensing images and socio-economic data, this paper constructed land transfer matrix and land carbon sink model to analyze the changes of land carbon sink capacity in poverty-stricken counties and identified the relevant impact factors through geographic detectors. The results show significant changes in carbon sink-type land and a continuous decrease in the snow area, resulting in an obvious trend of grassland area decrease and barren area increase. Land carbon sink capacity of poverty-stricken counties during the eradication of extreme poverty is higher with an added value of 2.74 times than that before this period. Using the geographic detector to analyze the related factors, strong explanatory power was found in cash crops per capita, share of secondary industry, population density and per capita savings on the changes of carbon sink capacity in poverty-stricken counties. [ABSTRACT FROM AUTHOR]

This paper presents triangular core fiber for single-mode operation. The fiber supports single mode at a wavelength of 1550-nm, and it has an extremely large mode area of 2000 μm². With peak power of 85.4-kW at 1550 nm wavelength, fiber design demonstrates undistorted delivery of 100 fs laser pulses. We have used Transfer matrix method to analyse the fiber. The splitstep Fourier method has been used to solve the non-linear Schrodinger equation. Raman's response and self-steepening have also been taken in to account. In this paper, we report the numerical demonstration of propagation of 100-fs pulse with peak power of 85.4-kW at 1550-nm wavelength through 2.5 m long fiber. The ratio of dispersion length to nonlinear length has been kept as 1 for the delivery of undistorted pulses. [ABSTRACT FROM AUTHOR]

Bimetal clad planar waveguide having polyaniline polymer as a guiding layer is proposed and studied for biosensing applications. The dispersion relation and reflectivity of the proposed sensor is obtained using transfer matrix method. The sensing performance and stability of proposed waveguide-based sensor is optimized using different volume fraction of Ag–Au bimetal. The volume fraction 1 represents pure Ag metal coating waveguide that shows maximum sensing performance in our all considered cases. In this case, maximum obtain sensitivity, detection accuracy and quality parameter is 74.140, 11.199 and 559.970°/RIU respectively, at the cover refractive index 1.410. Since, resonance angle and full width at half maxima of resonance peak decreases with increase of Ag metal percentage in Ag–Au bimetal therefore the presence of Au metal decreases the sensing performance of the sensor. Hence, a small volume fraction of Au metal is recommended for higher sensitivity with stability. [ABSTRACT FROM AUTHOR]

This paper investigates the influence of soil with finite depth on the vibrational behavior of a multi-span continuous beam resting on an elastic foundation. The simplified model of the Timoshenko beam supported on soil with finite depth is established, introducing the foundation displacement decay function. The numerical solution of the continuous beam's vibration response on the elastic foundation is obtained by using the transfer matrix method (TMM) and fourth-order Runge-Kutta method (RK4). Taking a two-span continuous beam as an illustrative example, the validity of the calculation theory is validated by comparing it with the outcomes obtained from the finite element method (FEM). Utilizing numerical computation and parametric analysis, the vibration response of continuous beams is evaluated in terms of its influence by various factors such as soil thickness, viscous damping coefficient of the soil, subgrade reaction coefficient, and span ratio. The findings indicate that the inertial motion of the soil with a finite depth significantly reduces the continuous beam's inherent frequency and enhances the structure's resonance effect. The rise of the subgrade response coefficient increases the system's resonant frequency while decreasing the displacement response amplitude. The ratio between the adjacent spans determines the effect of beam span vibration energy transfer to adjacent spans. In addition, compared with the span directly excited by a concentrated harmonic load, the impact of soil thickness, subgrade reaction coefficient, and viscous damping, the coefficient of the soil is more significant on the indirect influence span of a continuous beam. [ABSTRACT FROM AUTHOR]

Numerous researchers have dedicated efforts toward enhancing the efficiency of solar cells, particularly through the utilization of multi-junction or tandem solar cell configurations. However, a common approach employed by many researchers involves the use of the standard absorption formula (SAF) to determine the transmitted spectrum from the top cell to illuminate the bottom cells. The SAF method relies on conventional absorption calculations, neglecting reflection, refraction, and parasitic absorption losses. In this study, the transfer matrix (TRM) method, which accounts for reflection and refraction losses and an interference effect, is reported for the accurate calculation of a filtered spectrum. A comparative analysis between the SAF and TRM approaches reveal that the TRM technique provides a more accurate representation of the transmitted spectrum, particularly when considering reflection, refraction, and parasitic absorption losses. The primary aim of this research is to precisely predict the efficiency of tandem configurations by integrating multiple low-bandgap semiconductor bottom cells (BCs) with a top cell (TC) based on high-bandgap perovskite (PVK). Furthermore, the optimization of current matching is achieved by adjusting the thicknesses of the top absorber layer (TAL) and bottom absorber layer (BAL) based on the obtained filtered spectra. Tandem devices optimized using the TRM approach exhibit superior performance, achieving efficiencies of 28.72% (PVK/c-Si), 27.88% (PVK/CIGS), and 29.99% (PVK/PVK). This comparative investigation underscores the importance of considering reflection and refraction losses in tandem solar cell design and highlights the effectiveness of the TRM technique in enhancing device performance. [ABSTRACT FROM AUTHOR]

We assess the cavity molecular dynamics method for the calculation of vibrational polariton spectra using liquid water as a specific example. We begin by disputing a recent suggestion that nuclear quantum effects may lead to a broadening of polariton bands, finding instead that they merely result in anharmonic red shifts in the polariton frequencies. We go on to show that our simulated cavity spectra can be reproduced to graphical accuracy with a harmonic model that uses just the cavity-free spectrum and the geometry of the cavity as input. We end by showing that this harmonic model can be combined with the experimental cavity-free spectrum to give results in good agreement with optical cavity measurements. Since the input to our harmonic model is equivalent to the input to the transfer matrix method of applied optics, we conclude that cavity molecular dynamics cannot provide any more insight into the effect of vibrational strong coupling on the absorption spectrum than this transfer matrix method, which is already widely used by experimentalists to corroborate their cavity results. [ABSTRACT FROM AUTHOR]

A semiclassical method is presented for the calculation of Feshbach resonance positions and widths. This approach, based on semiclassical transfer matrices, relies only on relatively short trajectory fragments, thus avoiding problems associated with the long trajectories needed in more straightforward semiclassical techniques. Complex resonance energies are obtained from an implicit equation that is developed to compensate for the inaccuracy of the stationary phase approximation underlying the semiclassical transfer matrix applications. Although this treatment requires calculation of transfer matrices for complex energies, an initial value representation method makes it possible to extract such quantities from ordinary real-valued classical trajectories. This treatment is applied to obtain positions and widths for resonances in a model two-dimensional system, and the results are compared to those obtained from accurate quantum mechanical calculations. The semiclassical method successfully captures the irregular energy dependence of resonance widths that vary over a range of more than two orders of magnitude. An explicit semiclassical expression for the width of narrow resonances is also presented and serves as a simpler, useful approximation for many cases. [ABSTRACT FROM AUTHOR]