Relative Fluctuations Research Articles

Reservoir characteristics and potential of a shallow-marine multi-level fan in the Miocene Huangliu Fm. within the DF1-1 gas field (Yinggehai Basin, S China)

Deep-marine fans receive much attention because of their high potential for hydrocarbon exploration. Shallow-marine fans are much rarer and less well investigated. Particularly the formation and reservoir distribution of shallow-marine multi-level submarine fans are still hardly understood. Integration of data from cores, well logs, 3D seismics, in combination with analyses of thin-sections, porosity and permeability of Member 1 of the Miocene Huangliu Formation in the DF1-1 Gas Field of the Yinggehai Basin (S China) has provided much new information on the characteristics, development, and hydrocarbon potential of the reservoirs in such a type of fan. The study indicates that the IIb Gas Level of this member is built of three 5th-order sequences. The fan consists of channels, levees, ‘overbank’ sand sheets, and pro-fan silt- and mudstones. The development of this fan was controlled mainly by alternating subcritical and supercritical gravity flows, sediments supply and relative sea-level fluctuations. The NW-SE running channels occur on three slightly different levels that form 3 zones with chutes-and-pools morphology, which results in a multi-level submarine fan with zones of different sand thickness. The sand content of the channels and sand sheets is commonly higher than 50%. The reservoir sands underwent intermediate compaction and show mainly primary intergranular pores with short contacts. The porosity is 13.7–19.5% and the permeability ranges from 3.2 to 14.2 mD. The best reservoirs are the sand sheets, followed by channel sediments. The various reservoirs are commonly not interconnected due to lithological and stratigraphic traps. A new reservoir distribution model of submarine fans could thus be developed, which will facilitate oil and gas exploration.

The buffering effect of a paper-based storage enclosure made from functional materials for preventive conservation

Storage enclosures made of paper-based materials are commonly used to store and classify archival documents for their hygrothermal buffering effect. However, there is little information about papermaking and quantitative studies on such an effect. Aiming to assess the feasibility of using the enclosure to buffer temperature and relative humidity fluctuations, without any detrimental effect on the collections, this paper reports four measurements and a feasibility assessment: thermophysical properties of the enclosure material, hygroscopic properties of the material, air change rate of the enclosure, buffering effect in a climate chamber and the assessment of safeguarding collections without causing any detrimental effect. The measurement results show that the enclosure can buffer macro-environmental fluctuations, which was considered sufficient to mitigate temperature and humidity fluctuations from the room environment and to secure a condition inside that is safe for the collections. The paper-based material determines the buffering capacity of the enclosure, and an appropriate air change rate ensures average temperature and relative humidity inside the enclosure at a controllable level and prevents off-gassing accumulation. This work provides assurance that using enclosures is an effective approach to collection storage and establishes a significant basis for further heat–air–moisture simulation and energy-saving optimisation study in the service operation.

Gypsum-Based Humidity-Control Material: Preparation, Performance and Its Impact on Building Energy Consumption.

This paper introduces a new type of gypsum-based humidity-control material. The material combines gypsum-silica gel humidity-control material with 20% sepiolite powder activated by calcium chloride. Both experimental and simulation studies were conducted to assess its humidity-control performance. The experimental results indicate that gypsum-based humidity-control material has the property of absorbing moisture in high-humidity environments and releasing moisture in low-humidity environments. Moreover, both environmental temperature and relative humidity (RH) have an impact on the material's humidity-control performance. At a relative humidity of 97.4%, the maximum equilibrium moisture content of the material is 0.225 g/g, which is 1.4 times that of the gypsum-silica gel humidity-control material and 4.5 times that of pure gypsum material. The simulation results indicate that gypsum-based humidity-control material effectively mitigates indoor relative humidity fluctuations and maintains indoor air relative humidity within a narrow range. Furthermore, the material has the potential to reduce building energy consumption. This is especially evident under climate conditions with large temperature and relative humidity differences between day and night, such as in Beijing, Paris, and Atlanta. The maximum potential energy-saving rate in Beijing can reach up to 19.31%.

Fluctuations of formin binding in the generation of membrane patterns

Circular actin waves that propagate on the substrate-attached membrane of Dictyostelium cells separate two distinct membrane domains from each other: an inner territory rich in phosphatidyl-(3,4,5) trisphosphate (PIP3) and an external area decorated with the PIP3-degrading 3-phosphatase PTEN. During wave propagation, the inner territory increases at the expense of the external area. Beyond a size limit, the inner territory becomes unstable, breaking into an inner and an external domain. The sharp boundary between these domains is demarcated by the insertion of an actin wave. During the conversion of inner territory to external area, the state of the membrane fluctuates, as visualized by dynamic landscapes of formin B binding. Here we analyze the formin B fluctuations in relation to three markers of the membrane state: activated Ras, PIP3, and PTEN.

Bounds on nonequilibrium fluctuations for asymmetrically driven quantum Otto engines.

For a four-stroke asymmetrically driven quantum Otto engine with working medium modeled by a single qubit, we study the bounds on nonequilibrium fluctuations of work and heat. We find strict relations between the fluctuations of work and individual heat for hot and cold reservoirs in arbitrary operational regimes. Focusing on the engine regime, we show that the ratio of nonequilibrium fluctuations of output work to input heat from the hot reservoir is both upper and lower bounded. As a consequence, we establish a hierarchical relation between the relative fluctuations of work and heat for both cold and hot reservoirs and further make a connection with the thermodynamic uncertainty relations. We discuss the fate of these bounds also in the refrigerator regime. The reported bounds, for such asymmetrically driven engines, emerge once both the time-forward and the corresponding reverse cycles of the engine are considered on an equal footing. We also extend our study and report bounds for a parametrically driven harmonic oscillator Otto engine.

Properties of fluorescent chiral carbon microspheres and nanodots synthesized by a one-step hydrothermal method

Fluorescent carbon microspheres (CMSs) and carbon nanodots (CNDs) synthesized together in one pot have received much attention in the past decade. Here we report the use of L- and D-ascorbic acids (AA) to prepare CMSs with different chirality and CNDs with different fluorescent emission by the hydrothermal method. The CMSs emit a blue light while the CNDs emit a green one under 365 nm UV light. The reaction conversions of CMSs prepared with this method are over 25% when the reaction temperature is above 180°C. Circular dichroism, specific rotation, and photoluminescence of CMSs were measured. The analyses show that the L- and D-AA-based CMSs exhibit different chiral spectra. The graphene-like structures of CMSs are revealed by Raman spectroscopy. A possible formation mechanism of the CMSs and CNSs is proposed. In addition, the CMSs after calcination were found to achieve higher electrical and thermal conductivities comparable to those of the commercial carbon black. Photoluminescence analyses of CNDs show that the relative fluctuation between the blue and green emissions determines the shifting of blue and green hybrid color of the synthesized CNDs. D-AA derived CNDs show a higher quantum yield (QY) close to 1% and a stronger green emission. The blue-emitting CNDs and the green-emitting ones could be separated with the larger green CNDs kept inside the dialysis tube.

Optimal Ordering Decisions in Portfolio Procurement Considering Spot Price Fluctuation

This paper studies a newsvendor’s optimal ordering decisions in portfolio procurement from long-term contracts and spot purchases. In portfolio procurement, the newsvendor can order commodities in a long-term contract to meet market demand, and the excess demands can be supplemented from the spot market. Firstly, the newsvendor’s optimal ordering quantity in long-term contracts to maximize the expected profits is achieved when the spot price fluctuation is not considered. Furthermore, the newsvendor’s optimal ordering quantity is derived when the spot price fluctuation is considered. The research will show that the newsvendor’s optimal ordering decisions change with market parameters. Spot price fluctuation has a significant influence on optimal ordering decisions in portfolio procurement. This research uses the method of relative fluctuation of spot price and long-term contract price, which is more applicable in practice. It is shown that the newsvendor’s optimal ordering quantity in a long-term contract increases with the spot price fluctuation, which implies that price fluctuation in the spot market leads to a greater order quantities in long-term contracts. Moreover, it is proven that the newsvendor’s expected profit obtained from portfolio procurement decreases with increasing spot price fluctuation. Finally, this is verified by numerical experiments, and several management insights are suggested.

The Late Paleozoic Ice Age in western equatorial Pangea: Context for complex interactions among aeolian, alluvial, and shoreface sedimentary environments during the Late Pennsylvanian – early Permian

The evolution of depositional environments in the Late Pennsylvanian-early Permian of the Paradox Basin in Utah, USA, is investigated through detailed sedimentological and high-resolution sequence stratigraphic analyses, in order to define a model of landscape evolution, to discuss the stratigraphic model, and to evaluate the significance of the cyclicity in the paleoclimatic context. Forty high-resolution cycles integrated in 15 minor and two major cycles are observed for the first time throughout the Late Pennsylvanian-early Permian units. A-three steps landscape evolution is recognized. First, the lower Cutler beds, mainly corresponded to a marine environment, with longshore bar, subtidal, tidal, mouth-bar, and with locally fluvial deposits. The upper part of the lower Cutler beds also contains an aeolian dune. Second, the Cedar Mesa Sandstone, corresponded to broad erg deposits which are present across the entire study area, whereas longshore bar, subtidal, mouth-bar, and some fluvial deposits are mainly preserved in the northern part of the studied area. Third, the Organ Rock Formation records decreasing aeolian dune field preservation. To the south, the aeolian environments are interbedded with shoreface deposits, whereas to the north, fluvial deposits with some mouth-bars are more developed. Semi-arid climatic conditions persisted, as indicated by the presence of calcretes. Everywhere in these three steps, root traces within sandstone bars indicate that a soil was once present above the sand dunes. This new model of landscape evolution documents complex interactions between aeolian, fluvial and marine environments within the entire Permian succession of the Paradox Basin. High-resolution stratigraphic analyses allow to discuss the significance of the cyclicity in a scenario that take into consideration sea-level variation in the Late Paleozoic Ice Age paleoclimatic context. This Late Pennsylvanian to early Permian succession reflects both relative sea-level fluctuations and the variability of sediment supply.

Petrography and geochemistry of the Permian-Triassic boundary interval, Kangjiaping section, South China: Implication for the drastic marine environment change

The Permian-Triassic transitional interval exposed well at Kangjiaping section, northwestern Hunan, South China, contains microbialites, oolitic and oncolitic limestones intercalated with vermiculate micritic limestones in the Lower Triassic overlying the uppermost Permian bioclastic limestones, which provides an excellent opportunity to study the environmental changes after the end-Permian mass extinction (EPME) and the origins and environmental significance of these various anomalous sediments. In this paper, we describe in detail the petrographic and geochemical characteristics of these anomalous sediments, together with the reconstruction of the marine environment after the EPME. The continental margin weathering was significantly enhanced after the EPME, indicated by the higher concentrations of terrigenous minerals, Th, Sc, Sr, and rare earth elements in the Lower Triassic carbonates than in the uppermost Permian bioclastic limestones. Indicators such as V/(V + Ni) and Ni/Co ratios suggest that the oxygen content of shallow seawater significantly decreased after the EPME. While, most samples from the Kangjiaping section preserve a negative cerium anomaly, indicating the shallow seawater was still oxygenated both before and after the EPME. In addition, the abnormally rapid carbonate precipitation rate indicates a supersaturation state with respect to calcium carbonate in the shallow seawater after the EPME, but the depth and salinity of seawater and climate indicated by different microfacies are still different. Under the setting of a rapid transgression after the EPME, the microbialites first deposited on the platform with the exclusion of grazers at the beginning of the Early Triassic, followed by the oncolites formed when the climate turned humid with a relative sea-level rise. The oolites were primarily deposited in an arid climate with a relative sea-level fall, and the salinity and hydrodynamics of seawater controlled the ooids’ grain sizes. In contrast, the (vermiculate) micritic limestones were mainly formed in a humid climate with a relative sea-level rising and more terrigenous inputs. Therefore, the periodic relative sea-level fluctuation and arid-humid climate alternations play a vital role in the evolution and repeat stacking of various microfacies in the Kangjiaping section.

Multimerizations, Aggregation, and Transfer Reactions of Small Numbers of Molecules.

Chemical equilibria of multimerizations in systems with small numbers of particles exhibit a behavior seemingly at odds with that observed macroscopically. In this paper, we apply the recently proposed expression of equilibrium constant for binding, which includes cross-correlations in reactants' concentrations, to write an equilibrium constant for the formation of clusters larger than two (e.g., trimer, tetramer, and pentamer) as series of two-body reactions. Results obtained by molecular dynamics simulations demonstrate that the value of this expression is constant for all concentrations and system sizes, as well as at an onset of a phase transition to an aggregated state, where densities in the system change discontinuously. In contrast, the value of the commonly utilized expression of equilibrium constant, which ignores correlations, is not constant and its variations can reach few orders of magnitude. Considering different paths for the same multimer formation, with elementary reactions of any order, yields different expressions for the equilibrium constant, yet, with exactly the same value. This is also true for routes with essentially zero probability to occur. Existence of different expressions for the same equilibrium constant imposes equalities between averages of correlated, along with uncorrelated, concentrations of participating species. Moreover, a relation between an average particle number and relative fluctuations derived for two-body reactions is found to be obeyed here as well despite couplings to additional equilibrium reactions in the system. Analyses of transfer reactions, where association and dissociation events take place on both sides of the chemical equation, further indicate the necessity to include cross-correlations in the expression of the equilibrium constant. However, in this case, the magnitudes of discrepancies of the uncorrelated expression are smaller, likely because of partial cancellation of correlations, which exist on both the reactant and product sides.

Evaluation of Watershed Water Quality Management According to Flow Conditions through Factor Analysis and Naïve Bayes Classifier

Previous studies on water quality assessment for watershed management have predominantly focused on specific seasonal or annual average values, rather than considering water quality variations based on flow fluctuations. It is crucial to identify the water quality characteristics within a watershed by incorporating flow conditions to establish a customized watershed management approach over different time periods. In this study, a vulnerability analysis was conducted to attain the target water quality (TWQ) in 22 watersheds within the Nakdong River system in South Korea. Additionally, factor analysis (FA) was employed to analyze the characteristics of water quality fluctuations in relation to flow conditions. The FA results categorized the pollution source characteristics of the 22 watersheds into various types, indicating the need for specific pollution source management strategies. These findings enabled an initial decision-making process regarding which water pollution sources to prioritize based on flow conditions. Moreover, detailed analyses of pollution sources were performed for watersheds, where achieving TWQ was challenging. Subsequently, a data-based prediction model was developed using the naïve Bayes classification model to determine the likelihood of achieving TWQ. As a result, this study proposes a technique for water quality management in watersheds by introducing a water quality excess probability model, which employs data-based analysis instead of traditional numerical modeling for watershed water quality assessment and proactive prediction. The study discusses the potential of various data-based tools to reduce development and analysis time, providing a powerful alternative to physical-based models that require extensive input data and are time-consuming. To advance future studies, the establishment of comprehensive water environment big data, improvement of real-time monitoring systems within watersheds, and advancements in spatial and temporal observation technologies are emphasized as essential for the development of an advanced watershed management system.

Characteristics and Geological Significance of High-Frequency Cycles in Salinized Lake Basins: The Paleogene Kumugeliemu Group in the Xinhe Area, Northern Tarim Basin

Salinized lake basins have distinctive sedimentary response characteristics, similar to marine shallow-water carbonate platforms. High-frequency cycles can also be used to reveal more sedimentological information, such as relative lake-level fluctuations, lithofacies sequence combinations, and paleogeographic evolution. In this article, a comprehensive study on the stratigraphic shelf delineation and high-frequency cycles of the Paleozoic Kumugeliemu Group in Xinhe area, northern Tarim Basin, was performed using drilling cores, logging curves, and seismic analyses. As a result of the study, the following data were obtained: the three sets of marker beds in the Kumugeliemu Group in the study area could be divided into a bottom sandstone component (E1-2 km1), a lower gypsum mudstone component (E1-2 km2), a salt rock component (E1-2 km3), and an upper gypsum mudstone component (E1-2 km4) by petrology vertical overlay combination and isochronous tracking correlation, which constituted two third-order cycles (ESQ1, ESQ2). They were further divided into seven fourth-order cycles (Esq1–Esq7). Due to the droughty and saline lacustrine depositional system background, the internal rock fabric changed frequently and showed a periodic vertical overlay pattern. Stratified gypsum salt, gypsum mud (sand) rock, and gypsum rock were used as the cycle interface. A single cycle was mainly characterized by an upward shallower depositional sequence of rapid lake transgression followed by a slow lake regression, composed of massive sandstone–lamellar mudstone–lime dolomite–gypsum rock, massive sandstone–lamellar mudstone–gypsum rock (gypsum salt), massive sandstone–massive gypsum mud (sand) rock–gypsum rock, and other cycle structure types. The complete sedimentary cycle was superposed by a single cycle and compared by the inter-well thickness difference, indicating that the study area had a paleogeomorphology pattern of “West-Low–East-High”. The thickness of the cycles decreased gradually from bottom to top vertically, and five sedimentary stages were determined, i.e., freshwater, brackish, brackish water, salt lake, and semi-saltwater, reflecting the evolutionary process of increasing salinity, lake basin filling, and gradual salinization and shrinkage.

Toward vendor-independent measurement of cerebral venous oxygenation: Comparison of TRUST MRI across three major MRI manufacturers and association with end-tidal CO2.

Cerebral venous oxygenation (Yv ) is a valuable biomarker for a variety of brain diseases. T2 relaxation under spin tagging (TRUST) MRI is a widely used method for Yv quantification. In this work, there were two main objectives. The first was to evaluate the reproducibility of TRUST Yv measurements across MRI scanners from different vendors. The second was to examine the correlation between Yv and end-tidal CO2 (EtCO2 ) in a multisite, multivendor setting and determine the usefulness of this correlation to account for variations in Yv caused by normal variations and physiological fluctuations. Standardized TRUST pulse sequences were implemented on three scanners from major MRI vendors (GE, Siemens, Philips). These scanners were located at two research institutions. Ten healthy subjects were scanned. On each scanner, the subject underwent two scan sessions, each of which included three TRUST scans, to evaluate the intrasession and intersession reproducibility of Yv . Each scanner was also equipped with a capnograph device to record the EtCO2 of the subject during the MRI scan. We found no significant bias in Yv measurements across the three scanners (P = 0.18). The measured Yv values on the three scanners were also strongly correlated with each other (intraclass correlation coefficients > 0.85, P < 0.001). The intrasession and intersession coefficients of variation of Yv were less than 4% and showed no significant difference among the scanners. In addition, our results revealed that (1) within the same subject, Yv increased with EtCO2 at a rate of 1.24 ± 0.17%/mmHg (P < 0.0001), and (2) across different subjects, individuals with a higher EtCO2 had a higher Yv , at a rate of 0.94 ± 0.36%/mmHg (P = 0.01). These results suggest that (1) the standardized TRUST sequences had similar accuracies and reproducibilities for the quantification of Yv across the scanners, and (2) recording of EtCO2 may be a useful complement to Yv measurement to account for CO2 -related physiological fluctuations in Yv in multisite, multivendor studies.

Microstructural and Mechanical Behavior Investigations of Nb-Reinforced Mg–Sn–Al–Zn–Mn Matrix Magnesium Composites

This research focuses on the fabrication and characterization of TAZ532-xNb composites, employing high-purity, micron-sized powders of Mg, Sn, Al, Zn, Mn, and Nb as the raw materials. These powders were subjected to a paraffin coating process aimed at mitigating oxidation. The formation of composites was achieved via hot pressing and was followed by surface preparation and analysis using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). An X-ray diffraction (XRD) study was conducted to identify the microstructural phases. Quantitative assessments including the theoretical density, actual density, and relative density were computed, and their fluctuations in relation to the increasing Nb reinforcement ratio were scrutinized. Furthermore, the mechanical attributes of the composites, such as hardness and tensile strength, were assessed via experimental procedures. The absence of oxygen-related peaks in the XRD patterns endorsed the successful execution of the paraffin coating technique and protective gas atmosphere during sintering. The detection of α-Mg, Mg2Sn, MgZn, Mg17Al12, and Nb phases within the Nb-reinforced composite patterns authenticated the formation of the intended phases. Notably, the relative density values of the composites surpassed 95%, indicating efficient sintering. SEM results disclosed a densely packed microstructure, with Nb reinforcement particles evenly distributed along the grain boundaries, devoid of particle clustering or significant grain growth. These composites manifested exceptional wetting characteristics, which can be attributed to the employment of Mg alloy as the matrix material. EDS data confirmed the proportions of Nb within the composites, aligning with the quantities incorporated during fabrication. The composites showcased an increase in microhardness values with the escalating Nb reinforcement ratio, credited to the harder constitution of Nb particles in comparison to the matrix alloy. Concurrently, tensile strength showed a significant improvement with the increment in Nb reinforcement, while elongation values peaked at a specific Nb reinforcement level. The positive evolution of tensile strength properties was ascribed to the escalated Nb reinforcement ratio, grain size, and consequent higher sample densities.

Particle pump-out induced by trapped electron mode turbulence in electron cyclotron heated plasmas on XuanLong-50 spherical torus

Particle pump-out effects induced by low-frequency (<200 kHz) density fluctuations were observed in solely electron cyclotron wave (ECW)-heated plasmas on the spherical torus XuanLong-50 (EXL-50) without a central solenoid. The intensity of the relative density fluctuations increases with increasing ECW power and decays when the ECW is turned off while sustaining the plasma current. The electron densities are maintained relatively high and steady when the density fluctuations are completely absent, indicating that the outward transport of electrons is dominated by the particle pump-out effect of the ECW. The density fluctuations are modulated by a supersonic molecular beam injection pulse and the modulation amplitude decreases with increasing electron density at the same ECW injection power and decreasing ECW power at the same electron density, respectively. Analysis revealed that a critical value of electron temperature gradient (ETG) triggers the density fluctuations, and the intensity of the relative density fluctuations is positively correlated with the ETG and approximately inversely proportional to the effective collision frequency. With plasma parameters similar to those of EXL-50 experiments, the HD7 code simulations demonstrate that trapped electron mode (TEM) turbulence can be excited by ETG higher than the critical value observed in the experiment. In addition, the dependence of the mode growth rate (supposed to be proportional to the saturation level of fluctuations in quasi-linear theory) and the measured intensity of the density fluctuations is comparable. The simulated outward particle flux integrated over the poloidal wave number spectrum is significant and proportional to ETG. These observations demonstrate that the density fluctuation is TEM turbulence, which is driven by ETG and induces particle pump-out when the electron density/effective electron collision frequency is low. The potential relevance of this work with the controls of plasma profiles, impurities, helium ash, and heat transport in future reactors of similar low effective collision frequency is also discussed.

A reference-free dual-comb spectroscopy calibrated by passive devices

Dual-comb spectroscopy has enabled new approaches for optical precision measurements. Although Doppler-limited resolution can be achieved over long-time scales across a large bandwidth, the development of dual-comb spectroscopy is hindered by strict demands for light source stability. Typically, expensive and complex self-reference systems are required to lock the carrier-envelope offset frequency (fceo) of the laser. Additionally, simply locking the repetition frequency (frep) to a radio frequency reference source still results in residual relative timing jitter between light sources. Here we extracted the relative fceo fluctuation between the frep-locked lasers from the high-precision passive notch filtering characteristics of the phase-shifted fiber Bragg grating and then eliminated it through online phase calibration. By introducing a passive broadband Fabry–Perot cavity with excellent thermal wavelength stability, we subsequently corrected residual relative timing jitter with online wavelength calibration, and the standard deviation of the relative wavelength drift was reduced to less than 0.4 pm within the full operating range. The spectral profile can also be extracted and removed by the Fabry–Perot cavity through intensity calibration. By calibrating these three dimensions, we built a reference-free post-calibration dual-comb spectroscopy and used this powerful tool to measure the Fabry–Perot cavity resonance peaks, the notch filtering narrow band of phase-shifted fiber Bragg gratings, and the absorption characteristics of hydrogen cyanide gas. The system achieves a spectral resolution of 0.8 pm over a bandwidth of more than 100 nm. This low-cost and convenient scheme provides new ideas for the application of dual-comb spectroscopy systems.

Oscillating Solitons and ac Josephson Effect in Ferromagnetic Bose-Bose Mixtures.

Close to the demixing transition, the degree of freedom associated with relative density fluctuations of a two-component Bose-Einstein condensate is described by a nondissipative Landau-Lifshitz equation. In the quasi-one-dimensional weakly immiscible case, this mapping surprisingly predicts that a dark-bright soliton should oscillate when subject to a constant force favoring separation of the two components. We propose a realistic experimental implementation of this phenomenon which we interpret as a spin-Josephson effect in the presence of a movable barrier.

Anisotropic flow and flow fluctuations of identified hadrons in Pb–Pb collisions at sqrt{s_{textrm{NN}}} = 5.02 TeV

The first measurements of elliptic flow of π±, K±, textrm{p}+overline{textrm{p}} , {textrm{K}}_{textrm{S}}^0 , Lambda +overline{Lambda} , ϕ, {Xi}^{-}+{overline{Xi}}^{+} , and {varOmega}^{-}+{overline{varOmega}}^{+} using multiparticle cumulants in Pb–Pb collisions at sqrt{s_{textrm{NN}}} = 5.02 TeV are resented. Results obtained with two- (v2{2}) and four-particle cumulants (v2{4}) are shown as a function of transverse momentum, pT, for various collision centrality intervals. Combining the data for both v2{2} and v2{4} also allows us to report the first measurements of the mean elliptic flow, elliptic flow fluctuations, and relative elliptic flow fluctuations for various hadron species. These observables probe the event-by-event eccentricity fluctuations in the initial state and the contributions from the dynamic evolution of the expanding quark–gluon plasma. The characteristic features observed in previous pT-differential anisotropic flow measurements for identified hadrons with two-particle correlations, namely the mass ordering at low pT and the approximate scaling with the number of constituent quarks at intermediate pT, are similarly present in the four-particle correlations and the combinations of v2{2} and v2{4}. In addition, a particle species dependence of flow fluctuations is observed that could indicate a significant contribution from final state hadronic interactions. The comparison between experimental measurements and CoLBT model calculations, which combine the various physics processes of hydrodynamics, quark coalescence, and jet fragmentation, illustrates their importance over a wide pT range.

Ensemble nonequivalence and Bose–Einstein condensation in weighted networks

The asymptotic (non)equivalence of canonical and microcanonical ensembles, describing systems with soft and hard constraints respectively, is a central concept in statistical physics. Traditionally, the breakdown of ensemble equivalence (EE) has been associated with nonvanishing relative canonical fluctuations of the constraints in the thermodynamic limit. Recently, it has been reformulated in terms of a nonvanishing relative entropy density between microcanonical and canonical probabilities. The earliest observations of EE violation required phase transitions or long-range interactions. More recent research on binary networks found that an extensive number of local constraints can also break EE, even in absence of phase transitions. Here we study for the first time ensemble nonequivalence in weighted networks with local constraints. Unlike their binary counterparts, these networks can undergo a form of Bose–Einstein condensation (BEC) producing a core–periphery structure where a finite fraction of the link weights concentrates in the core. This phenomenon creates a unique setting where local constraints coexist with a phase transition. We find surviving relative fluctuations only in the condensed phase, as in more traditional BEC settings. However, we also find a non-vanishing relative entropy density for all temperatures, signalling a breakdown of EE due to the presence of an extensive number of constraints, irrespective of BEC. Therefore, in presence of extensively many local constraints, vanishing relative fluctuations no longer guarantee EE.

A simple approach to determine loss of physiological complexity in heart rate series

There are several ways to assess complexity, but no method has yet been developed for quantitatively calculating the ‘loss of fractal complexity’ under pathological or physiological states. In this paper, we aimed to quantitatively evaluate fractal complexity loss using a novel approach and new variables developed from Detrended Fluctuation Analysis (DFA) log-log graphics. Three study groups were established to evaluate the new approach: one for normal sinus rhythm (NSR), one for congestive heart failure (CHF), and white noise signal (WNS). ECG recordings of the NSR and CHF groups were obtained from PhysioNET Database and were used for analysis. For all groups Detrended Fluctuation Analysis scaling exponents (DFAα 1, DFAα 2) were determined. Scaling exponents were used to recreate the DFA log-log graph and lines. Then, the relative total logarithmic fluctuations for each sample were identified and new parameters were computed. To do this, we used a standard log-log plane to standardize the DFA log-log curves and calculated the differences between the standardized and expected areas. We quantified the total difference in standardized areas using parameters called dS1, dS2, and TdS. Our results showed that; compared to the NSR group, DFAα 1 was lower in both CHF and WNS groups. However, DFAα 2 was only reduced in the WNSgroup and not in the CHFgroup. Newly derived parameters: dS1, dS2, and TdS were significantly lowerin the NSR group compared to the CHF and WNS groups. The new parameters derived from the DFA log-log graphs are highly distinguishing for congestive heart failure and white noise signal. In addition, it may be concluded that a potential feature of our approach can be beneficial in classifying the severity of cardiac abnormalities.