Spatial Jumps Research Articles

Analysis of the spatial-temporal evolution of Green and low carbon utilization efficiency of agricultural land in China and its influencing factors under the goal of carbon neutralization

Agricultural land is the most basic input factor for agricultural production and an essential component of terrestrial ecosystems, which plays a vital role in achieving carbon neutrality. Giving full play to the carbon-neutral contribution of agricultural land is a crucial part of China's economic transformation and green development. It incorporates carbon and pollution emissions from agricultural land use into the unexpected outputs of the Green and Low-carbon Utilization Efficiency of Agricultural Land (GLUEAL) evaluation system. The study utilized several advanced analytical tools, including the super-efficient Slacks-Based Measure (SBM) model, Exploratory Spatial-Temporal Data Analysis (ESTDA) method, Geodetector, and Geographically and Temporally Weighted Regression (GTWR) model. The objective was to examine the spatial-temporal evolution of GLUEAL and identify the factors that influenced it in all 31 provinces of China from 2005 to 2020. The results show that: (1) The overall spatial-temporal evolution of GLUEAL showed an increasing trend, but the disparity between provinces and regions became wider. (2) Most provinces have not yet made significant spatial and temporal jumps. They have high spatial cohesion with specific "path-dependent" characteristics. (3) The Geodetector results reveal that the Number of Rural Labor Force with Higher Education (NRLFHE) and Technology Support for Agriculture (TSA) have insufficient explanatory power on average for GLUEAL. Agricultural Economic Development Level (AEDL), Urbanization Level (UL), Multiple Crop Index (MCI), Planting Structure (PS), Degree of Crop Damage (DCD), Financial support for agriculture (FSA), and Agricultural mechanization level (AML) had stronger explanatory power on average for GLUEAL and were important factors influencing GLUEAL levels. (4) The average influence of AEDL, UL, FSA, and AML on GLUEAL changed from negative to positive. The average influence of MCI and DCD on GLUEAL was negative, and the average influence of PS on GLUEAL changed from positive to negative. This study provides a comprehensive description of the spatial and temporal evolution of GLUEAL in China. It reveals the key factors influencing GLUEAL and analyzes their spatial variations and impact patterns. These findings offer robust evidence for government policymakers to formulate policy measures for sustainable agricultural development and optimized resource allocation, promoting the transformation of agricultural land towards green and low-carbon practices and advancing the achievement of sustainable development goals.

Spatio-temporal heterogeneity of the coupling between digital economy and green total factor productivity and its influencing factors in China.

The synergy of the digital economy and green total factor productivity (TFP) is the foundation for achieving beneficial outcomes for both the economy and environment. This synergy is also the catalyst for high-quality development and sustainable economic growth in China. The study applied a modified Ellison-Glaeser (EG) index, super-efficiency slacks-based measure (SBM) with a Malmquist-Luenberger (ML) index, coupling coordination degree, and other models to explore the spatiotemporal heterogeneity of the coupling between the digital economy and green TFP from 2011 to 2020 and also analyzed the influencing factors of the coupling. The results show that the coupling between the digital economy and green TFP showed an overall upward trend from imbalance to synergy during the study period. The distribution of the synergistic coupling expanded from point-like to band-like, and there was a significant spreading pattern from the east to the center or west China. The number of cities in a transition state decreased significantly. Spatial jumps, a coupling linkage effect, and evolution in time were prominent. Additionally, the absolute difference among cities expanded. Although coupling in the west experienced the fastest growth rate, the coupling in the east and resource-based cities showed significant benefits. Coupling did not reach an ideal coordinated state, and a neutral interaction pattern remains to be formed. Industrial collaboration, industrial upgrading, government support, economic foundation, and spatial quality all positively impacted the coupling; technological innovation had a lagged effect; and environmental regulation has not reached its full potential. Further, the positive effects of government support and spatial quality performed better in the east and in non-resource-based cities. Due to the optimization of industrial structure, the coupling of the west and resource-based cities achieved better dividends; however, spatial quality needs further improvement. Therefore, the efficient coordination of China's digital economy and green TFP requires a scientific, reasonable, localized, and distinctive approach.

Investigating the Pressure Fluctuations of Hydraulic Jump in an Abrupt Expanding Stilling Basin with Roughened Bed

Stilling basins with sudden expansions are one of the energy dissipation structures. In the hydraulic jump, pressure fluctuations cause significant damages in stilling basins by cavity formation, erosion, and vibration. Roughness can also lead to changes of the behavior of stream lines and vortices. Despite the large number of works on the topic, the role of roughness in spatial hydraulic jumps is not yet fully understood. Present research aimed to study the influence of rough bed on pressure fluctuations of S-jump in abrupt expanding stilling basin. Experiments were conducted in a 0.8 m width and 12 m length flume. Channel expansions ratios were 0.33, 0.5, 0.67, and 1 within the range of Froude numbers, 2 to 9.5. The results showed that roughness decreases intensity of pressure fluctuations in an abrupt expansion stilling basin. Additionally, in sudden expanding sections, the energy loss increases, and the intensity of pressure fluctuations decrease due to the formation of lateral vortices. The reduction rate of maximum pressure fluctuation was 27%, 46%, and 58% for expansion ratio of 0.67, 0.5, and 0.33, respectively. The results revealed the clear dependence of these variables on the Froude number and the distance to the hydraulic jump toe. The maximum values of extreme pressure fluctuations occur in the range 0.609 < X < 3.385, where X is dimensionless distance from the toe of the hydraulic jump, which makes it highly advisable to reinforce the bed of stilling basins in this range.

Gutter politics: Graphic novels in the age of Trump

This article explores the ways in which US graphic novels have responded to, narrated and politically framed the Trump presidency. Analysing a generically diverse range of texts from non-fiction to science fiction, I argue that comics artists were quick to mobilize the medium’s unique qualities in the service of ideological critique. The article offers a detailed account of how publications such as Sabrina (2018), The Hard Tomorrow (2019), LaGuardia (2019) and Welcome to the New World (2020) were developed, shaped and reshaped against the backdrop of Donald Trump’s election victory and presidential term. Through an assortment of formal and stylistic devices – spatial and temporal jumps and juxtapositions afforded by panel arrangement, a weaving together of historical and contemporaneous iconography, the interplay of various textual cues and registers – these graphic novels offered complex portrayals of the impact of Trump and ‘Trumpism’ on various individuals, groups and communities. In different ways, they evidence the medium’s ability to intervene in wider political discourse, construct challenging historical and speculative narratives and offer fresh, resonant engagements with pressing issues of the day.

Experimental Analysis on the Use of Counterflow Jets as a System for the Stabilization of the Spatial Hydraulic Jump

This study presents an investigation on the use of submerged counterflow jets as a means for stabilizing the spatial hydraulic jump occurring in abruptly expanding channels. The characteristics of the flow downstream from the stilling basin and the main parameters influencing the effectiveness of the device in improving flow uniformity and reducing scouring potential are examined in laboratory tests, under several geometric configurations and hydraulic boundary conditions. The position within the stilling basin and the jet density (i.e., the number of orifices issuing the counterflow jets) were found to be important parameters influencing the performance of the device. Overall, the results indicate that this dissipation system has promising capabilities in forcing the transition from supercritical to subcritical flow, by significantly shortening the protection length needed to limit the phenomena of instability associated with spatial hydraulic jumps.

A Random Walk Approach to Transport in Tissues and Complex Media: From Microscale Descriptions to Macroscale Models.

The biological processes necessary for the development and continued survival of any organism are often strongly influenced by the transport properties of various biologically active species. The transport phenomena involved vary over multiple temporal and spatial scales, from organism-level behaviors such as the search for food, to systemic processes such as the transport of oxygen from the lungs to distant organs, down to microscopic phenomena such as the stochastic movement of proteins in a cell. Each of these processes is influenced by many interrelated factors. Identifying which factors are the most important, and how they interact to determine the overall result is a problem of great importance and interest. Experimental observations are often fit to relatively simple models, but in reality the observations are the output of complicated functions of the physicochemical, topological, and geometrical properties of a given system. Herein we use multistate continuous-time random walks and generalized master equations to model transport processes involving spatial jumps, immobilization at defined sites, and stochastic internal state changes. The underlying spatial models, which are framed as graphs, may have different classes of nodes, and walkers may have internal states that are governed by a Markov process. A general form of the solutions, using Fourier-Laplace transforms and asymptotic analysis, is developed for several spatially infinite regular lattices in one and two spatial dimensions, and the theory is developed for the analysis of transport and internal state changes on general graphs. The goal in each case is to shed light on how experimentally observable macroscale transport coefficients can be explained in terms of microscale properties of the underlying processes. This work is motivated by problems arising in transport in biological tissues, but the results are applicable to a broad class of problems that arise in other applications.

“Everything is Connected”

The paper discusses the storytelling formulas of the first season of the German series Dark (2017–2020) by focusing on the key temporal and spatial aspects of seriality in the show, such as the time frame of diegesis (story time), the temporal structure of the story (discourse and narration time) and the unique temporal installation of the series. As argued, the story and visual textuality of Dark not only transcends time and space – thus to provide us with a complex narrative set – but, by atemporal and spatial storytelling jumps, it creates a map of inconsistencies of double discontinuity fairly new to television and serial narration. By focusing on these spatial-temporal aspects of the series, the paper sketches a new approach to postmodern television formulas, while it also offers a possible interpretation to the national characteristics of the production based on the recurring theme of captivity in time.

Numerical Study of Fluctuating Pressure on Stilling Basin Slab with Sudden Lateral Enlargement and Bottom Drop

A stilling basin with sudden enlargement and bottom drop leads to complicated hydraulic characteristics, especially a fluctuating pressure distribution beneath 3D spatial hydraulic jumps. This paper used the large eddy simulation (LES) model and the TruVOF method based on FLOW-3D software to simulate the time-average pressure, root mean square (RMS) of fluctuating pressure, maximum and minimum pressure of a stilling basin slab. Compared with physical model results, the simulation results show that the LES model can simulate the fluctuating water flow pressure in a stilling basin reliably. The maximum value of RMS of fluctuating pressure appears in the vicinity of the front of the stilling basin and the extension line of the side wall. Based on the generating mechanism of fluctuating pressure and the Poisson Equation derived from the Navier–Stokes Equation, this paper provides a research method of combining quantitative analysis of influencing factors (fluctuating velocity, velocity gradient, and fluctuating vorticity) and qualitative analysis of the characteristics of fluctuating pressure. The distribution of fluctuating pressure in the swirling zone of the stilling basin and the wall-attached jet zone is mainly affected by the vortex and fluctuating flow velocity, respectively, and the distribution in the impinging zone is caused by fluctuating velocity, velocity gradient and fluctuating vorticity.

Pressure Fluctuations in the Spatial Hydraulic Jump in Stilling Basins with Different Expansion Ratio

Pressure fluctuations are a key issue in hydraulic engineering. However, despite the large number of studies on the topic, their role in spatial hydraulic jumps is not yet fully understood. The results herein shed light on the formation of eddies and the derived pressure fluctuations in stilling basins with different expansion ratios. Laboratory tests are conducted in a horizontal rectangular flume with 0.5 m width and 10 m length. The range of approaching Froude numbers spans from 6.4 to 12.5 and the channel expansion ratios are 0.4, 0.6, 0.8, and 1. The effects of approaching flow conditions and expansion ratios are thoroughly analyzed, focusing on the dimensionless standard deviation of pressure fluctuations and extreme pressure fluctuations. The results reveal that these variables show a clear dependence on the Froude number and the distance to the hydraulic jump toe. The maximum values of extreme pressure fluctuations occur in the range 0.609<X<3.385, where X is dimensionless distance from the toe of the hydraulic jump, which makes it highly advisable to reinforce the bed of stilling basins within this range.

Three-dimensional numerical study of submerged spatial hydraulic jumps

Abstract A three-dimensional numerical model was applied to simulate submerged spatial hydraulic jumps (SSHJ) downstream of a symmetric vent that discharges into a wider channel. Simulations were carried out for different aspect ratios of the vent, expansion ratios of vent width to downstream channel width, tailwater depth, and inlet Froude number. Depending on these factors, simulations indicated the formation of steady asymmetric SSHJ, oscillatory asymmetric SSHJ, and steady symmetric SSHJ, consistent with results of previous experimental studies. The model reproduced observed depth downstream of vent, jump length, and velocity profiles along channel centerline for steady symmetric SSHJ. For oscillatory asymmetric SSHJ, simulated oscillation frequencies had Strouhal numbers that varied with expansion ratio and ranged between 0.003 and 0.015. With piers downstream of the vent, oscillatory SSHJ continued to exhibit jet deflections when pier length was relatively short ( ≲ 0.2 of jump length) but became steady asymmetric for longer piers.

Directed continuous-time random walk with memory

In this paper, we are addressing the old problem of long-term nonlinear autocorrelation function versus short-term linear autocorrelation function. As continuous-time random walk (CTRW) can describe almost all possible kinds of diffusion, it seems to be an excellent tool to use. To be more precise, for instance, CTRW can successfully describe the short-term negative autocorrelation of returns in high-frequency financial data (caused by the bid-ask bounce phenomena). We observe long-term autocorrelation of absolute values of returns. Can it also be described by the CTRW model? And maybe more importantly, to what extent can it be explained by the same phenomena? To refer to these questions, we propose a new directed CTRW model with memory. The canonical CTRW trajectory consists of spatial jumps preceded by waiting times. In directed CTRW, we consider the case with positive spatial jumps only. We take into account the memory in the model as each spatial jump depends on the previous one. This model, based on simple assumptions, allowed us to obtain the general formula covering most popular types of nonlinear autocorrelation functions.Graphical abstract

Space as Storyteller. Spatial Jumps in Architecture, Critical Theory, and Literature

Space as Storyteller. Spatial Jumps in Architecture, Critical Theory, and Literature

Space as Storyteller: Spatial Jumps in Architecture, Critical Theory, and Literature by Laura Chiesa

A review of Laura Chiesa's Space as Storyteller, a book on the narrative possibilities of architectural space, with particular emphasis on the theories of Walter Benjamin, the experiments of the Futurist movement, and the contemporary architecture of such figures as Bernard Tschumi,Rem Koolhaas, and the collective Superstudio.

Space as Storyteller: Spatial Jumps in Architecture, Critical Theory, and Literature by Laura Chiesa

Space as Storyteller: Spatial Jumps in Architecture, Critical Theory, and Literature by Laura Chiesa

The hydrogen diffusion in liquid aluminum alloys from ab initio molecular dynamics.

We study the hydrogen diffusion in liquid aluminum alloys through extensive ab initio molecular dynamics simulations. At the microscopic scale, we show that the hydrogen motion is characterized by a broad distribution of spatial jumps that does not correspond to a Brownian motion. To determine the self-diffusion coefficient of hydrogen in liquid aluminum alloys, we use a generalized continuous time random walk model recently developed to describe the hydrogen diffusion in pure aluminum. In particular, we show that the model successfully accounts the effects of alloying elements on the hydrogen diffusion in agreement with experimental features.

Non-LTE models for synthetic spectra of Type Ia supernovae

Context. Type Ia supernovae (SN Ia) have become an invaluable cosmological tool as their exceptional brightness makes them observable even at very large distances (up to redshifts around z~1). To investigate possible systematic differences between local and distant SN Ia requires detailed models whose synthetic spectra can be compared to observations, and in which the solution of the radiative transfer is a key ingredient. One commonly employed method is the Feautrier scheme, which is generally very robust, but which can yield wrong results under certain conditions that frequently occur in the modelling of supernova ejecta or even in the radiatively driven expanding atmospheres of hot stars. Methods. We use a sophisticated model atmosphere code which takes into account the non-LTE effects and high velocity gradients that strongly affect the physics of SN Ia atmospheres at all wavelengths to simulate the formation of SN Ia spectra by the thousands of strong spectral lines which intricately interact with the "pseudo-continuum" formed entirely by these Doppler-shifted lines themselves. We focus to an investigation of the behavior of the Feautrier scheme under these conditions. Results. Synthetic spectra of SN Ia, a complex product of computer models replicating numerous physical processes that determine the conditions of matter and radiation in the ejecta, are affected by large spatial jumps of the line-dominated opacities and source functions for which the application of even well-established methods may harbor certain pitfalls. We analyze the conditions that can lead to a breakdown of conventional procedures and we derive for the Feautrier radiative transfer solver a modified description which yields more accurate results in the given circumstances.

SU‐D‐18C‐03: In Vivo MR Imaging Using a Combined Single‐Point Dixon and Phase‐Sensitive Inversion Recovery Technique

Purpose:To demonstrate combined single‐point Dixon water/fat separation and phase sensitive inversion recovery imaging in in vivo brain images acquired in a single scan.Methods:A single inversion recovery image is acquired with an inversion‐time (TI) selected to maximize the dynamic range of the longitudinal magnetization of the water signals and at an echo time (TE) to introduce an orthogonal phase‐difference (i.e. 90°) between the fat and water signals. In the image reconstruction, spatially smooth background phase errors due to static magnetic field inhomogeneity are estimated by applying a region growing based phase correction algorithm: the algorithm first determines spatial phase jumps of 180° and then the second spatial phase jumps of 90°. After the background phase‐errors are removed from the acquired image, phase sensitive inversion recovery (PSIR) water‐only image and a separate fat‐only image can be generated as the real and imaginary parts of the phase‐corrected image, respectively.Results:The pulse sequence was implemented on a 3T whole‐body clinical scanner and a single brain image of a healthy volunteer was acquired. The acquired image was confirmed to contain an orthogonal phase difference between water and fat boundaries and 180o phase difference between the boundaries of long and short T1‐water tissues. The background phase errors were successfully determined and removed by the proposed phase correction algorithm and uniformly separated fat‐only and PSIR water‐only images were reconstructed without artefacts.Conclusion:We demonstrated combined single‐point Dixon water/fat separation and PSIR imaging in in vivo brain images acquired in a single scan. Such images can be useful when fat suppression and enhanced T1‐contrast are desired. Potential areas of application may include imaging of the brain or myocardium.

Ab initio based understanding of diffusion mechanisms of hydrogen in liquid aluminum

Ab initio molecular dynamics simulations are used to describe the diffusion of hydrogen in liquid aluminum at different temperatures. We show that the hydrogen motion does not follow a Brownian motion caused by a broad distribution of spatial jumps that can exceed 15 times the interatomic AlH distance. This breakdown is also evidenced in the calculation of the self-part of the van Hove distribution function that is not the Gaussian expected for a Fickian process. We show that the hydrogen motion can be described well by a generalized continuous time random walk model leading to computed self-diffusion coefficients of H in liquid aluminum in good agreement with experimental ones. Finally, the impact of impurities and alloying elements is discussed.

Necessary and sufficient conditions for the presence of global potentials in space

It is shown that either the presence of a magnetic flux in a finite spatial region or jumps in the field strength are necessary to generate a global potential. The problem of detecting the magnetic Aharonov—Bohm effect is discussed.

Pressure fluctuations beneath spatial hydraulic jumps

This article deals with statistical analysis of pressure fluctuations at the bottom of spatial hydraulic jumps with abrupt lateral expansions. The effects of the channel expansion ratio and inflow condition on the power spectral and dominant frequency were examined. Pressure data were recorded for different Froude numbers ranging from 3.52 to 6.86 and channel expansion ratios ranging from 1.5 to 3.0. A sampling frequency of 100 Hz was selected. The measurements were conducted in the bed of a glass-walled laboratory flume by means of pressure transducers and data acquisition systems. Power spectra as well as dominant frequency and some other statistical characteristics of fluctuating pressure beneath hydraulic jumps were obtained. Test results were compared with those of classical jump, which indicates that the peak frequencies and intensity coefficients of pressure fluctuations are higher than those of the corresponding classical jumps.