Influence Of Spatial Structure Research Articles

Research on the Influence of Spatial Structure on Carbon Emission Synergy of Urban Agglomeration—Based on the Development Process of Yangtze River Delta Urban Agglomeration in China

Carbon emissions, as an indicator of green economic development in urban agglomerations, are closely related to the degree of coordinated development between cities. Additionally, urban agglomerations, as a highly developed form of urban space, are widely regarded as a more efficient, energy-saving, and land-saving urbanization method. This article constructs an urban agglomeration network based on relevant data from listed companies in the Yangtze River Delta urban agglomeration with practical connections between cities and uses social network analysis methods and a fixed effects model to calculate the impact of overall and individual network indicators of urban agglomerations on urban carbon emissions and collaborative emission reduction of urban agglomerations. The regression results indicate that the centrality of individual cities has a significant negative correlation with the intensity of urban carbon emissions, with a coefficient of −0.067. The centrality of core cities has a significant positive impact on the collaborative emission reduction of urban agglomerations, with a coefficient of 0.0138. The impact of network density on the collaborative emission reduction of urban agglomerations shows an inverted U-shaped curve. Based on the analysis results, the paper explores the spatial structure construction method and industrial development control strategy based on urban agglomeration collaborative emission reduction.

Mesoscopic evolution and kinetic properties of dense granular flow crystallization under continuous shear induction

The influence of spatial structure on the kinetic response of discrete soft matter is critical. The exploration is not limited to structural evolution, jamming point, phase transition, etc. However, the mesoscopic response under continuous loading has always been difficult to make progress in experiments. In this study, we explored the mesoscopic evolution and properties of the ordered structure in dense granular flow under continuous shear by experiments and simulations. It shows that the crystal structure of the particles develops simultaneously inward from the boundary of the shearing cell. Two morphological clusters formed one after another within a 2D cylindrical layer parallel to the boundary. At the single-particle level, continuous strain is found to make the crystallization process within the cylindrical layers an evolution of chain-like polycrystalline to monocrystal structures. Compared to oscillatory shear, splicing or fusion is the way to reach the final state from the transition state under continuous shear rather than epitaxial growth. Due to continuous shear, the symmetry of the crystal switches between hexagonal close-packed (HCP) and face-centered cubic (FCC) and is dynamically balanced in the flow. We also describe the switching path. The results show that HCP in flow is more favored by the environment than FCC.

Polychaete (Annelida) Diversity Patterns in Southern Gulf of Mexico: The Influence of Spatial Structure and Environmental Variables

A comprehensive database was built to examine the spatial diversity patterns of polychaete species from the continental shelf in Southern Gulf of Mexico. Using Cluster and nMDS analysis we found the composition of polychaete species to be different between the terrigenous and carbonate regions of the Gulf. To test the relative importance of spatial and environmental components in the polychaetae community structure in the Southern Gulf of Mexico, we examined the spatial relationships between polychaetae assemblages and environmental variables over broad geographical scales. A distance-based redundancy analysis (dbRDA) and variation partitioning was used to quantify the relative importance of these explanatory variables on the spatial variations of species richness and composition. Variation partitioning is an important tool to investigate the importance of spatial structure to species distribution in communities, but it has not yet been used in marine ecosystems. The significance level of spatial and environmental components to the distribution of polychaete species showed that the combined effect of spatial processes and sediment characteristics explained a higher percentage of variance than those parameters could alone.

Influence of spatial structure on protein damage susceptibility: a bioinformatics approach

Aging research is a very popular field of research in which the deterioration or decline of various physiological features is studied. Here we consider the molecular level, which can also have effects on the macroscopic level. The proteinogenic amino acids differ in their susceptibilities to non-enzymatic modification. Some of these modifications can lead to protein damage and thus can affect the form and function of proteins. For this, it is important to know the distribution of amino acids between the protein shell/surface and the core. This was investigated in this study for all known structures of peptides and proteins available in the PDB. As a result, it is shown that the shell contains less susceptible amino acids than the core with the exception of thermophilic organisms. Furthermore, proteins could be classified according to their susceptibility. This can then be used in applications such as phylogeny, aging research, molecular medicine, and synthetic biology.

Spatial Heterogeneity Analysis of PM2.5 Concentration in Central Plains Economic Region

The research of the spatial heterogeneity of PM2.5 concentration in an area, is of great significance for understanding its regional spatial distribution structure, exploring the transmission relationship between regions, in order to formulate joint prevention and control measures within the entire area. Based on the daily monitoring data of PM2.5 concentration in the Central Plains Economic Region in 2019, this paper utilizes cluster analysis to divide the regional PM2.5 concentration into 5 classes, builds their spatial semi-variogram model, and then utilizes interpolation analysis method to study the regional overall distribution characteristics and transmission law. The results show that the PM2.5 concentration in the Central Plains Economic Region has a medium or higher spatial autocorrelation. The critical value of the overall PM2.5 concentration in the area is 150 μg/m3, as the overall PM2.5 concentration less than the value, the PM2.5 in a region mainly comes from local emissions, as the overall PM2.5 concentration higher than the value, the influence of spatial structure on the distribution of PM2.5 concentration is gradually obvious. PM2.5 has a certain degree of spatial transmission, which mainly includes two routes as Puyang-Xingtai and Puyang-Zhengzhou, and the transmission intensity of the former is greater than the latter.

Топокліматичні особливості садово-паркових композиційних груп у парках міста Львова

Проаналізовано історико-стильовий генезис урбанізованих ландшафтів і формування системи садово-паркових насаджень міста Львова. Досліджено вплив місцевих ландшафтних геосистем і геофізичних процесів у них на формування топокліматичних характеристик парків. З'ясовано еколого-біологічні відмінності та особливості формування просторових природних явищ у певній садово-парковій композиції. Встановлено, що вивчення топокліматичних відмінностей потрібно починати із розгляду потоків сонячної радіації, температури повітря та ґрунту, атмосферних опадів і вітру. Проаналізовано територіальні еколого-біологічні відмінності та особливості формування просторових природних явищ залежно від потоків речовини та енергії. Виявлено вузькі амплітуди температури в геокомплексах вершин, середини і підніжжя схилів, бар'єрний вплив на міграцію та місцеву трансформацію повітряних мас, що впливає на специфіку піднаметового фітоценозу. Охарактеризовано врахування топокліматичних характеристик для підвищення комфортності розвитку садово-паркових композиційних груп. Відзначено, що поверхня пагорбів разом з мереживом стежок, прокладених на схилах, піддається ерозії та потребує зменшення та регулювання рекреаційного навантаження. Окреслено негативні явища, які сукупно із віковим чинником та відсутністю належного агротехнічного догляду впливають на умови місцезростання та розвиток паркових насаджень.

Influence of spatial structure on properties of rice kernel as compared with its flour and starch in limited water

Insight into the architecture and the interaction between components in fully mature rice are difficult to study but are important to its processing technology and quality control as it is mainly consumed as the whole kernel. In this study, different microscopy techniques were combined to explain the differences of rheological and thermal properties between rice kernel and its flour even though they had the same compositions. The area and positions of the endothermic peaks of starch, flour, and kernel were different. The uneven distribution of starch granules and part of the protein bodies were observed by a scanning electron microscope. The regional distribution and spatial structure of starch granules and cell walls showed the restriction effect of kernel structure of rice. The clear fluorescence by a confocal laser scanning microscope showed that the protein bodies and cell walls formed barriers in rice to delay the hydration and limit the expansion of starches. Overall, the structural form of rice is closely related to its physicochemical properties.

Recreational Business District boundary identifying and spatial structure influence in historic area development: A case study of Qianmen area, China

Tourism development is a useful strategy in historic area renewal, especially for Recreational Business District (RBD) development. However, there is also a challenge in maintaining a balance between protection and development. This study aims to put forward a method to identify the boundary of RBD based on Internet big data in a famous historic area in China. To reconcile heritage conservation with people's behavior, the authors applied a space syntax method to obtain an understanding of space in this historic area and explored the relationship between spatial structure and RBD development based on the axial map in a series of time periods: 1950, 1990, 2002 and 2016. The authors found that RBD has spatial advantages for aggregating people flows and subsequent business in the historic area. Additionally, a positive influence between spatial structure and RBD development was found. Finally, some proposals for balancing between historic preservation and RBD development were put forth.

Inconvertible p-tert-butylthiacalix[4]arene-core-star polystyrene conformers

Inconvertible star polystyrene conformers were synthesized by ATRP using initiators of different conformations from p-tert-butylthiacalix[4]arene. The influence of spatial structures of the star polystyrene conformers on properties was investigated.

Antenna Spatial Structure Influence on Communication System Capacity in Consideration of Transmitting Antenna Rotation

Questions of technical implementation of communication system with different antenna spatial structures are discussed. The paper reviews the design of a system for data transmission from a rotating object to the ground receiving station with various spatial MIMO antenna structures. Different variants of the onboard antenna array with a different number of antennas are investigated. Values of the channel matrix for the communication system for the object rotating around the longitudinal axis are calculated. Transmission rate averaged over the period of rotation according to the position of the object on the trajectory and spatial structure of the ground receiving station is calculated.

Influence of Spatial Structures of 316L Stainless Steel on its Cavitation Erosion Resistance

Cavitation erosion performance of modified macroscopic internal structure 316L stainless steel was investigated. The samples processed by means of SLM method were subjected to cavitation erosion test. The scanning electron microscope Philips 30/ESEM was used to examine morphology of eroded surface.

Influence of spatial structure with no explicit luminance information on lightness perception

Influence of spatial structure with no explicit luminance information on lightness perception

Evolution of Host Life-History Traits in a Spatially Structured Host-Parasite System

Most models for the evolution of host defense against parasites assume that host populations are not spatially structured. Yet local interactions and limited dispersal can strongly affect the evolutionary outcome, because they significantly alter epidemiological feedbacks and the spatial genetic structuring of the host and pathogen populations. We provide a general framework to study the evolution of a number of host life-history traits in a spatially structured host population infected by a horizontally transmitted parasite. Our analysis teases apart the selective pressures on hosts and helps disentangle the direct fitness effect of mutations and their indirect effects via the influence of spatial structure on the genetic, demographic, and epidemiological structure of the host population. We then illustrate the evolutionary consequences of spatial structure by focusing on the evolution of two host defense strategies against parasitism: suicide upon infection and reduced transmission. Because they bring no direct fitness benefit, these strategies are counterselected or selectively neutral in a nonspatial setting, but we show that they can be selected for in a spatially structured environment. Our study thus sheds light on the evolution of altruistic defense mechanisms that have been observed in various biological systems.

Temporal grouping in figure-ground segregation and the influence of spatial structure

Temporal grouping in figure-ground segregation and the influence of spatial structure

Weighted local sharing and local clearing for multimodal optimisation

Local sharing is a method designed for efficient multimodal optimisation that combines fitness sharing with spatially structured populations and elitist replacement. In local sharing, the bias towards sharing and the influence of spatial structure is controlled by the deme (neighbourhood) size. This introduces an undesirable trade-off; to maximise the sharing effect large deme sizes must be used, but the opposite must be true if one wishes to maximise the influence of spatial population structure. This paper introduces two modifications to the local sharing method. The first alters local sharing so that parent selection and fitness sharing operate at two different spatial levels; parent selection is performed within small demes, while the effect of fitness sharing is weighted according to the distance between individuals in the entire population structure. The second method replaces fitness sharing within demes with clearing to produce a method that we call local clearing. The proposed methods, as tested on several benchmark problems, demonstrate a level of efficiency that surpasses that of traditional fitness sharing and standard local sharing. Additionally, they offer a level of parameter robustness that surpasses other elitist niching methods, such as clearing. Through analysis of the local clearing method, we show that this parameter robustness is a result of the isolated nature of the demes in a spatially structured population being able to independently concentrate on subsets of the desired optima in a fitness landscape.

Assortative mating and mutation diffusion in spatial evolutionary systems

The influence of spatial structure on the equilibrium properties of a sexual population model defined on networks is studied numerically. Using a small-world-like topology of the networks as an investigative tool, the contributions to the fitness of assortative mating and of global mutant spread properties are considered. Simple measures of nearest-neighbor correlations and speed of spread of mutants through the system have been used to confirm that both of these dynamics are important contributory factors to the fitness. It is found that assortative mating increases the fitness of populations. Quick global spread of favorable mutations is shown to be a key factor increasing the equilibrium fitness of populations.

Source–sink dynamics sustain central stonerollers (Campostoma anomalum) in a heavily urbanized catchment

Summary1. The influence of spatial structure on population dynamics within river–stream networks is poorly understood. Utilizing spatially explicit analyses of temporal genetic variance, we tested whether persistence of central stonerollers (Campostoma anomalum) reflects differences in habitat quality and location within a highly modified urban catchment in southwestern Ohio, U.S.A.2. Estimates of genetic diversity did not vary with habitat quality. Nevertheless, evidence of weak but temporally stable genetic structure, location‐dependent effective population sizes and rates of immigration among sites, together suggest that persistence of central stonerollers within the catchment may be attributable to source–sink dynamics driven by habitat heterogeneity.3. Under this scenario, migrant‐pool colonization from areas of relatively high habitat quality in the upper catchment sustains the presence of central stonerollers at degraded sites in the main stem and dampens population subdivision within the catchment. However, because intact habitat is restricted to the upper portion of the catchment, it is not possible to preclude net downstream dispersal as a mechanism contributing to source–sink dynamics. The slight genetic structure that persists appears to reflect weak isolation by distance diminished by high rates of immigration.4. This study suggests that without a systems perspective of the conditions that sustain populations in degraded waterways, environmental assessments may underestimate levels of impairment. Conservation and management of stream fishes could be improved by maintaining habitat in areas that are net exporters of migrants or by remediation of impaired habitat.

Influence of spatial structure on the maintenance of sexual reproduction

We include spatial extension into a model for the maintenance of sexual reproduction introduced recently. The model is based on a broad spectrum of resources, which regrow slowly. Other key features of the model are that sexual reproduction sets in when resources become scarce and that only a few genotypes can coexist locally. The extension of the model to several patches in space is done in two different ways. Model A is based on central egg deposition and allows migration of juveniles into all patches. Model B has a one-dimensional array of patches with migration only between neighboring patches. The main findings are that wide dispersal favors asexuals, while for slower migration there is a wide range of parameter values for which sexually reproducing species always win against asexuals. These results are conform with major patterns for the distribution of parthenogenesis in animals and plants, i.e. the prevalence of parthenogenetic reproduction in minute species, which are easily dispersed by physical forces, such as protists and small metazoans including e.g. bdelloid rotifers, tardigrades and nematodes.

Long-Term Influence of the Spatial Structure of an Initial State on the Dynamics of a Forest Growth Model: A Simulation Study Using the Capsis Platform

Spatially explicit individual-based models are used more often in forest modeling, especially because they take into account the influence of the spatial structure on the dynamics. However, they are potentially very sensitive to the initial spatial structure used for a simulation, which can be problematic if the initial state is not known or is simulated in an unrealistic way.The aim of this article is to study this sensitivity to initial spatial structure in the case of the “Mountain” model, an individual-based model of irregular spruce stands implemented in the Capsis platform.To characterize the influence of the initial spatial structure on the dynamics of the model, the authors simulated different initial spatial structures and compared the results of long-term simulations. They showed that the initial spatial structure can highly influence the dynamics of the model, not only during the first cycle of the evolution but also in the very long term in the evolution of the next generations. They also illustrated how some disturbances, such as a periodic gap opening through storms, can modify both the long-term dynamics of the stand and the duration of the influence of the initial spatial structure.

Influence of Spatial Structure on Accuracy of Interpolation Methods

Effectiveness of precision agriculture depends on accurate and efficient mapping of soil properties. Among the factors that most affect soil property mapping are the number of soil samples, the distance between sampling locations, and the choice of interpolation procedures. The objective of this study is to evaluate the effect of data variability and the strength of spatial correlation in the data on the performance of (i) grid soil sampling of different sampling density and (ii) two interpolation procedures, ordinary point kriging and optimal inverse distance weighting (IDW). Soil properties with coefficients of variation (CV) ranging from 12 to 67% were sampled in a 20‐ha field using a regular grid with a 30‐m distance between grid points. Data sets with different spatial structures were simulated based on the soil sample data using a simulated annealing procedure. The strength of simulated spatial structures ranged from weak with nugget to sill (N/S) ratio of 0.6 to strong (N/S ratio of 0.1). The results indicated that regardless of CV values, soil properties with a strong spatial structure were mapped more accurately than those that had weak spatial structure. Kriging with known variogram parameters performed significantly better than the IDW for most of the studied cases (P < 0.01). However, when variogram parameters were determined from sample variograms, kriging was as accurate as the IDW only for sufficiently large data sets, but was less precise when a reliable sample variogram could not be obtained from the data.