Three-level System Research Articles

Land scale division and multifunctional evaluation for Fuping County, China, based on DEM-based watershed analysis.

Land is the spatial background and basic carrier of human survival and development. The study of land function evaluation at different scales can promote the harmonious coexistence of humans and nature. Taking Fuping County, Hebei Province, China, as an example, this study establishes the theoretical framework of county-level land scale division using a digital elevation model (DEM)-based watershed analysis method and establishes the theory and methodological system of land function evaluation from the perspective of the characteristic scale. The multifunctionality of the land was evaluated using the Carnegie-Ames-Stanford approach (CASA), the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model and comprehensive index evaluation. By using the methods of DEM-based watershed analysis, dominant factor differentiation and layer superposition, a three-level scale system of 'subwatershed scale-land chain scale-land segment scale' and a multifunctional multiscale evaluation index system containing 18 evaluation indices were established. The single-function and multifunction evaluation results of land at different scales were obtained by the comprehensive index method and Getis-Ord Gi* index method. The accuracy of land function evaluation results mainly depends on the selection of the measurement scale. The land measurement scale determined by DEM-based watershed analysis is close to the intrinsic scale of land function evaluation. The scale effect of land function in different temporal and spatial ranges is also evident and shows obvious spatial heterogeneity and difference. At larger scales, individual functions show synergistic effects.

Vortex beam induced spatial modulation of quantum-optical effects in a coherent atomic medium

We have studied two-dimensional absorption, gain, and corresponding refractive index profiles in a ladder-type three-level atomic system interacting with three coherent fields. One is a weak probe field considered as a plane wave, while the other two are the control fields taken as two Laguerre–Gaussian doughnut beams. Position dependence of two vortex beams induces the spatially modulated coherence at the condition of resonance, which enables us to obtain space-dependent absorption, transparency, gain without inversion (GWI), and refractive index enhancement in the present scheme. The azimuthal modulation of coherence effects is attributed to the presence of optical angular momentum of the vortex beams. Under the influence of an additional travelling wave field with the presence of two vortex beams, the present model leads us to obtain an ultra-large enhancement of refractive index at the resonant detuning of the fields. This phenomenon makes the atom-field system to play the equivalent role of a high-refractive-index prism. The role of near dipole–dipole (NDD) interaction on the modulation of position-dependent coherence effects has also been investigated. It has been shown that, without any inclusion of the travelling wave field in the system, the phenomenon of resonant enhancement of refractive index may also occur in the presence of NDD effect. The new way of generating spatially controlled GWI and nonlinear refractive index enhancement is specific to the present model. This work seems to be useful for finding its applications in spatially modulated coherence controlled electromagnetically induced transparency-based quantum devices like quantum optical memory, switches, and quantum logic gates, where the refractive index switching phenomenon is a prerequisite.

Developing a geographical-meteorological indicator system and evaluating prediction models for alveolar echinococcosis in China.

Geographical and meteorological factors have been reported to influence the prevalence of echinococcosis, but there's a lack of indicator system and model. To provide further insight into the impact of geographical and meteorological factors on AE prevalence and establish a theoretical basis for prevention and control. Principal component and regression analysis were used to screen and establish a three-level indicator system. Relative weights were examined to determine the impact of each indicator, and five mathematical models were compared to identify the best predictive model for AE epidemic levels. By analyzing the data downloaded from the China Meteorological Data Service Center and Geospatial Data Cloud, we established the KCBIS, including 50 basic indicators which could be directly obtained online, 15 characteristic indicators which were linear combination of the basic indicators and showed a linear relationship with AE epidemic, and 8 key indicators which were characteristic indicators with a clearer relationships and fewer mixed effects. The relative weight analysis revealed that monthly precipitation, monthly cold days, the difference between negative and positive temperature anomalies, basic air temperature conditions, altitude, the difference between positive and negative atmospheric pressure anomalies, monthy extremely hot days, and monthly fresh breeze days were correlated with the natural logarithm of AE prevalence, with sequential decreases in their relative weights. The multinomial logistic regression model was the best predictor at epidemic levels 1, 3, 5, and 6, whereas the CART model was the best predictor at epidemic levels 2, 4, and 5.

On the coupling of three-level quantum refrigerators in the weak coupling limit

We propose a model of two identical autonomous quantum refrigerators that interact through their qubits coupled to cold thermal baths. We consider the same specific disposition for each refrigerator related to a three-level system coupled to different thermal baths and, in turn, to a qubit as the object to be cooled. By coupling the two systems, we show that under certain conditions on the model parameters, the devices can operate in the regime of an independent autonomous quantum refrigerator or be subject to an adjustment of the thermodynamic performances. We further investigate the correlations induced by the interaction between the two refrigerators, and illustrate their behavior with respect to their thermodynamic performances. We have found that adjusting the different interaction constants of the model can lead to an evolution of the quantum correlations of the two machines that is inversely related to the behavior of the thermodynamic quantities of both refrigerators. However, this is not necessarily the case when the temperatures of the model are considered as the reference parameters.

Gain-assisted quantum heat engine based on electromagnetically induced transparency

We propose a scheme to realize a gain-assisted quantum heat engine (QHE) based on electromagnetically induced transparency (EIT), which consists of a three-level Λ-type atomic system interacting with two thermal reservoirs and a coupling field. The gain without inversion is induced to the system via spontaneously generated coherence (SGC) between two lower levels. The SGC has significantly affect on the system’s dynamics, resulting in an enhancement of the emission cross-section and spectral brightness of the QHE.

Sustainable Financing for Transport Infrastructure: An Integral Approach for the Russian Federation

The development of global transport infrastructure is a crucial aspect of economic growth and prosperity. In this study, the main trends in the development of global transport infrastructure are analyzed, with a focus on the state and trends in the functioning of the national transport infrastructure of the Russian Federation. By identifying key problems and determinants of financial growth, a preliminary decomposition is made to guide future development. Proceeding from the fact that the innovative development of Russia’s transport infrastructure should occur through state stimulation of the development of intellectual and partnership relationships and the formation of a digital environment for managing projects for its innovative transformation at the state level, this study identifies the goals, methods, and levels of ensuring the implementation of innovative transformations in transport infrastructure. Consideration of the historical aspects of the formation of the modern economy and comprehension of the mechanisms of state management and tools to ensure innovative transformations in the sphere of transport allowed us to identify three stages (dogmatic, strategic regulation, and innovative integration) of transformation regarding the theory of the state management for the innovative development of transport infrastructure in Russia. Taking into account the content of these periods of transformation allowed us to detail the specifics of the modern stage; highlight the shortcomings; and propose theoretical and methodological foundations for revising the provisions of the state regulation of innovative development in transport infrastructure. To determine the effectiveness of the processes of the state regulation of innovation activity in the transport industry, we propose a model for assessing the effectiveness of innovation activity in the transport complex, which is presented in the form of a three-level parametric system, where the first group of indicators allows us to assess the innovation activity of economic entities in the transport industry; the second allows us to assess innovation potential; and the third allows us to assess the effectiveness of innovation. The novelty of the proposed model is the consideration of the principles of dynamism, perspective, and expediency, and its application allows us to establish the level of innovative development in transport infrastructure. An important factor in ensuring the sustainable development of a country’s economy and forming its positive image in the world is its financial attractiveness. Therefore, the assessment of financial attractiveness is a priority task for the development of modern sustainable transport infrastructure in Russia.

Parametric analysis and comprehensive multi-criteria evaluation of double-stage organic Rankine cycle

Double-stage organic Rankine cycle (DORC) is a more effective mechanism of circulation for recovering heat released from industrial wastewater. It is crucial to determine the optimum operating circumstances for the DORC system, and its effectiveness cannot be effectively assessed by applying a single objective evaluation approach. The AHP-entropy analysis method is utilized to establish a three-level assessment system, taking into account several indicators, in order to execute a thorough study of the DORC system. Eight organic fluids, including R113, R124, R1233zd(E), etc, are chosen as the working mediums of the DORC system. The results demonstrate that the heat source temperature exists maximum value that match the working fluids under the impact of the pinch point temperature difference and the critical temperature of the working medium. When the evaporation pressure increases, the whole system performance improves, according to the AHP-entropy analysis of the operating state that corresponds to the single goal optimum value. When the critical temperature of the working medium is approximately 50 °C above the hot water temperature for a given heat source, the system performs more effectively. Additionally, when the heat source temperature is close to the critical temperature of the eight organic fluids, the DORC system operates more effectively.

Azimuthal modulation of light propagation through 1DPCs via efficient nonlinear frequency mixing

The present study aims to investigate the transmitted and reflected light beams from a one-dimensional defect photonic crystal (1DPC) composed of a three-level ladder-type quantum system. The lower leg of the ladder scheme is driven by a weaker probe beam, while the upper leg is driven by a stronger control beam. Unlike natural atoms, this type of model with broken symmetry permits the generation of a sum-frequency signal beam between the majority of higher and lower quantum states, resulting in the formation of a cyclic closed-loop arrangement for the interaction between light and matter. The Laguerre Gaussian (LG) field with strong coupling and a weak probe light interact with the quantum system. A new weak signal light is produced as a result of the system’s symmetric breakdown, and the medium becomes azimuthal dependent. We investigate the spatial dependence of the transmitted and reflected light from a defect 1DPC by using azimuthal modulation of the LG light. Additionally, we will discuss how the absorption spectrum’s spatial modulation varies with winding numbers. We discover that in certain regions, the gain can be realized without population inversion under certain specified parametric parameters.

Goos–Hänchen shifts in a V-type three-level atomic system interacting with squeezed vacuum

This study explores the Goos–Hänchen (GH) shift phenomenon within a cavity hosting a V-type three-level atomic system, engaged with two independent broadband squeezed baths. Our exploration encompasses a thorough analysis of the lateral shifts in both reflected and transmitted light beams, with a focus on the impact of critical factors, i.e, coupling field strength, incoherent pumping field strength, and squeezed vacuum intensity. Our results reveal an interplay of these parameters, resulting in distinctive negative and positive GH shifts in both reflected and transmitted light. In addition, a remarkable enhancement of GH shifts at specific angles of incidence is observed, presenting a wide-ranging modulation across diverse system parameters. This study not only enriches the understanding of the GH shift in complex atomic systems but also highlights the potential for the manipulation of these lateral shifts by fine-tuning key variables of the system, and contributes valuable insights to the broader field of optical phenomena in quantum systems.

Resource and environmental carrying capacity study of Kubai Coalfield in Xinjiang based on RS and GIS

The study of resource and environmental carrying capacity (RECC) is critical to the ecological environmental protection and sustainable development of mining areas. Using multi-source remote sensing data such as Landsat5 and Landsat8, as well as socioeconomic statistics, the impact mechanism of the Kubai Coalfield's RECC was analyzed using the theory of Driving-Pressure-State-Impact-Response (DPSIR), and a three-level evaluation index system of 1-5-18 was proposed. The cloud model enhanced Analytic Hierarchy Process (AHP) was used to estimate the weight value of each assessment index. The Kubai Coalfield's RECC was calculated by superimposing the weights of different variables, and the contributing elements and changing trends of the RECC were investigated. The RECC of the Kubai Coalfield is highest in the east, second highest in the west, and lowest in the center, according to the results. The vegetation cover of the mining area has a direct impact on the RECC, and mining activity is the primary cause of the change in carrying capacity; however, coal mining has a lagging effect on the RECC. The study's findings serve as a guide for the quantitative assessment of RECC of Xinjiang's environmentally vulnerable mining sites and offer theoretical justification for the approach taken in the study of RECC of mining areas and the preservation of ecological environment sources.

Phase and detuning control of the unidirectional reflection amplification based on the broken spatial symmetry.

In order to achieve the tunable unidirectional reflection amplification in a uniform atomic medium that is of vital importance to design high-quality nonreciprocal photonic devices, we propose a coherent closed three-level Δ-type atomic system by applying a microwave field, and a strong coupling field of linear variation along the x direction to control a probe field. In our scheme, the linearly increased coupling field destroys the spatial symmetry of probe susceptibility and effectively suppresses the reflection of one side; the microwave field constructs closed loop transitions to amplify the probe field and causes phase changes. The numerical simulation indicates that the unidirectional reflection amplification is sensitive to the relative phase ϕ and the coupling detuning Δc. Our results will open a new route toward harnessing optical non-reciprocity, which can provide more convenience and possibilities in the experimental realization.

Peculiarities of legal regulation of the tax system of local self-government bodies in the Republic of Poland

The article is devoted to the analysis of the peculiarities of the legal regulation of the tax system of local self-government bodies in the Republic of Poland.
 It is shown that the modern system of local taxes began to form in the 90s of the last century, together with the restoration of the institution of local self-government. Despite the constitutional enshrinement of the right of all local self-government bodies to determine the amount of local taxes, ordinary legislation grants tax powers exclusively to the lowest link in the three-level system - the commune. Financing of the functions and powers of local self-government bodies of voivodships and poviats takes place through deductions from national taxes and fees. The author focuses on the existence of a distinction between the terms "local taxes” and "taxes of local self-government bodies” in the Polish doctrine of tax law. Local taxes are taxes that, by virtue of the law, are a permanent, indefinite and exclusive source of income for local budgets. Meanwhile, taxes of local self-government bodies are payments in respect of which local self­government bodies have tax powers. In light of the accepted criteria, for example, inheritance and gift tax is a local tax, but cannot be called a tax of local governments. Funds from this tax are fully credited to the budget of the territorial community, but local self-government bodies do not have tax authority over it. The list of local taxes is contained in the Law "On Local Taxes and Fees”. However, in reality, this list is incomplete and does not include a number of local taxes that are regulated by other legislative acts. In general, the list of local taxes is quite voluminous, in which only real estate tax, vehicle tax, forest tax and agricultural tax belong to the taxes of local self-government bodies. They meet the formal and material criteria that characterize the "own income” of local self-government units, while others only meet the formal criteria.

Controllable optical bistability and multistability in a V-type three-level atomic system interacting with two broadband independent squeezed baths

In this study, we investigate the optical bistability (OB) and optical multistability (OM) phenomena within a V-type three-level atomic system interacting with two independent broadband squeezed baths confined in a unidirectional cavity. Our analysis reveals that the transition between OB and OM is influenced by the strength of the control field and the intensity of the squeezed vacuum. Notably, the impact of each of these factors on the transition exhibits distinct characteristics. Furthermore, we explore the effects of additional system parameters, such as the incoherent pumping rate and cooperation parameter. Our findings emphasize the crucial roles played by these parameters in shaping the observed results. Specifically, we observe that variations in the incoherent pumping rate and cooperation parameter contribute significantly to the system’s OB and OM behavior, further underscoring the multifaceted nature of the studied atomic system. This comprehensive investigation not only elucidates the intricate interplay between key parameters but also unveils the sensitivity of the system to variations in control field strength, intensity of the squeezed vacuum, incoherent pumping rate, and cooperation parameter.

Bloch sphere analog of qudits using Heisenberg-Weyl Operators

We study an analogous Bloch sphere representation of higher-level quantum systems using the Heisenberg-Weyl operator basis. We introduce a parametrization method that will allow us to identify a real-valued Bloch vector for an arbitrary density operator. Before going into arbitrary d-level (d ≥ 3) quantum systems (qudits), we start our analysis with three-level ones (qutrits). It is well known that we need at least eight real parameters in the Bloch vector to describe arbitrary three-level quantum systems (qutrits). However, using our method we can divide these parameters into four weight, and four angular parameters, and find that the weight parameters are inducing a unit sphere in four-dimension. And, the four angular parameters determine whether a Bloch vector is physical. Therefore, unlike its qubit counterpart, the qutrit Bloch sphere does not exhibit a solid structure. Importantly, this construction allows us to define different properties of qutrits in terms of Bloch vector components. We also examine the two and three-dimensional sections of the sphere, which reveal a non-convex yet closed structure for physical qutrit states. Further, we apply our representation to derive mutually unbiased bases (MUBs), characterize unital maps for qutrits, and assess ensembles using the Hilbert-Schmidt and Bures metrics. Moreover, we extend this construction to qudits, showcasing its potential applicability beyond the qutrit scenario.

Identifying the system of value factors of green consumer choice

To justify the production of green products, it is necessary to anticipate the choice of consumers toward products with different environmental friendliness. Therefore, it is necessary to understand the factors that determine this choice, particularly value factors. The study is based on the idea that a consumer is stimulated to eco-consumption by a set of values, not excluding individualist values; and the influence of values is mediated by motives. The purpose of the study is to develop the theoretical foundations of constructing a three-level system of value factors of green consumption on the example of office paper consumption. As a result, the study formed a system of factors containing preferences, motives, and values of office paper consumers. According to the proposed approach, for each respondent, quantitative characteristics of the elements of the system of factors were determined through a survey, which made it possible to identify correlation relationships between the elements. A pilot study was used to test the proposed approach to constructing a value factors system. The results of the pilot survey showed a positive connection between eco-friendliness of consumer preferences – through motives – with such values as “Nature,” “Self-development,” “Country success,” and “Social power.” This finding provides additional justification for the assumption that individuals are driven to green consumption not only by socially oriented values but also by individualistic values. Identifying the value factors of green consumption will allow predicting consumer behavior and influencing it through targeted marketing offers.

Prediction of the biodegradation of chemicals using OECD QSAR Toolbox software

Introduction. The development of integrated approaches to testing, assessment of the hazard and exposure risk of chemicals on human health and the environment is one of the priorities of preventive toxicology. An integrated approach involves various combinations of methods in silico, in chemico, in vitro, ex vivo, in vivo for hazard assessment. In the Russian Federation, in silico methods are often perceived with skepticism, mainly due to the lack of their legal status, weak methodological base and insufficient training of specialists. In order to expand the methodological base, the possibility of predicting the stability of chemicals in biotic conditions using the OECD QSAR Toolbox software was studied.
 Material and methods. The OECD QSAR Toolbox software version 4.4.1., OECD guidelines on the assessment of biodegradation of chemicals.
 Results. The world community and the OECD have developed and implemented a three-level system for chemicals biodegradation testing, which includes tests for readily biodegradation (OECD Guidelines 301 A, 301 B, 301 C, 301 D, 301 E, 301 F, 306, 310), tests to determine the potential biodegradability (OECD Guidelines 302 A, 302 B, 302 C, 304 A) and model systems tests (OECD Guidelines 303 A, 303 B).
 To test the capabilities of the program, 24 endpoints were selected. They are the determination of biodegradability (%) by BOD, DOC, CO2, CH4 releases in OECD tests 301 A, 301 B, 301 C, 301 D, 
 302 C, 302 B, biodegradability (%) in sediments and soil, bioconcentration factors for more than 100 organic chemicals of various structures.
 The parameters were calculated using the analog method, followed by mandatory interpretation of the data obtained by an expert. When predicting the biodegradability of chemicals, it is necessary to perform a series of calculations using different tests (OECD tests 301 A, 301 B, 301 C, 301 D, 301 E, 302 B are preferred) and grouping methods followed by a comprehensive assessment of the results obtained, taking into account not only the structural similarity of substances and analogues, but also the quality of the experimental data used. When predicting biodegradability by BOD values, it is advisable to use the OECD 301 C test. The proportion of tested substances whose biodegradability could be estimated by BOD values is about 50% in the OECD 301 C test, which is primarily due to the presence of a significant amount of experimental data. The calculation of bioconcentration factors seems to be promising. For about 45% of the tested substances, it was possible to calculate bioconcentration coefficients with good correlation with experimental data. Biodegradation in soil (% and half-life) can be predicted only for a very limited range of compounds (10% of the tested substances), which is due to the difficulty of selecting structurally similar analogues with experimental data. The method is not applicable for predicting the biodegradation of salts, organometallic compounds, polymer molecules and mixed products.
 Conclusion. The Russian Register of Potentially Hazardous Chemical and Biological Substances has developed a methodological guide for predicting the stability of chemicals in biotic conditions using the OECD QSAR Toolbox software. The document presents algorithms for calculating biodegradability (%) according to OECD tests 301, 302, 303; BOD, bioconcentration factors and biodegradability (%) in soil.

Quantum Zeno effect: A qutrit controlled by a qubit

For a three-level system monitored by an ancilla, we show that the quantum Zeno effect can be employed to control quantum jump for error correction. Further, we show that we can realize cNOT gate, and effect dense coding and teleportation using a three-level system with an ancilla. We believe that this work paves the way to generalize the control of a qudit.

Robust and high-efficiency dynamical method of enantio-specific state transfer.

We propose a simple dynamical method to realize fast enantio-specific state transfer (ESST) of chiral molecules. Driven by three external electromagenetic fields, the chiral molecules are modeled as cyclic three-level systems, where the overall phase differs by π for the left- and right-handed chiral molecules. We unveil that the ESST is allowed when the amplitudes of three Rabi frequencies in the cyclic three-level systems are equal. Our method is robust and highly efficient in the sense that the external fields can have arbitrary waveforms. This thus provides the opportunity of simplifying the experimental implementations of ESST through pulse design.

Enhancement of fault ride-through capability of three-level NPC converter-based HVDC system through robust nonlinear control strategy

Voltage source converter-based high-voltage direct current (VSC-HVDC) transmission systems are becoming increasingly popular for long-distance power transmission due to their numerous advantages. However, the fault ride-through (FRT) capabil-ity of VSC-HVDC systems during AC faults remains a key challenge that needs to be addressed to ensure their uninterrupted operation under challenging grid conditions. This paper presents and analyzes a novel nonlinear control scheme based on a robust sliding mode control approach to improve the FRT capability of VSC-HVDC systems. The proposed control scheme based on the modification of the converter’s active power to make it more sensitive to any changes in voltage magnitude at the points of common coupling (PCCs) on the AC side. This helps to maintain the DC voltage sta-bility and prevent the converter from tripping during AC faults. The performance of the proposed control scheme is evaluated using a series of ex-perimental investigations using a digital signal processor (DSP) within Processor-in-the-Loop (PIL) quasi-real-time simulation. The PIL simulations closely examine the system’s response to AC faults with varying remaining voltages and durations. The results demonstrate that the proposed control scheme can effectively improve the FRT capability of VSC-HVDC systems and ensure their stable operation during AC faults.

Influence of phase diffusion on atomic grating in a three-level ladder-type system in lower-level microwave-driven scheme

In this paper, we consider a scheme for electromagnetically induced grating (EIG) in a three-level ladder-type system. A microwave field of finite bandwidth making a standing-wave pattern is applied on lower levels. In addition, we have also introduced an indirect pump in our system. A weak probe field is then applied to study the effects of phase diffusion associated with the microwave control field on EIG. It is found that phase diffusion associated with the strong microwave control field strongly affect the diffraction. We have incorporated the effect of different system parameters such as the strength of the microwave field, indirect pumping mechanism, interaction length, and detuning in the weak probe field. Interestingly, the stronger microwave control field retrieves the loss in diffraction intensity caused by the phase diffusion. Our results show that the introduction of detuning in the optical probe field results in the enhancement of the phase grating effect. Furthermore, our results show that an optimized indirect pump field can slightly improve the first-order diffraction intensities both in the absence and presence of phase diffusion.