Dynamic Change Process Research Articles

The Dynamic Heterogeneous Relationship between Urban Population Distribution and Built Environment in Xi’an, China: A Case Study

The interaction between the population and built environment is a constant topic in urban spaces and is the main driving force of urban evolution. Understanding urban population distribution and its relationship with the built environment could provide guidance for urban planning, traffic, and disaster management. Following this line of thought, this study conducted an empirical analysis in Xi’an, a rapidly developing western city in China. Well-permeated mobile phone location data were used to represent the spatiotemporal dynamics of the population, and the built environment was characterized from five perspectives—transportation, location, building, greenery, and land use—using multisource geospatial data. Finally, the dynamic heterogeneous influence of built environment factors on population distribution was examined using multiscale geographically weighted regression (MGWR). Overall, the influencing coefficients exhibited a significant dynamic changing process from a temporal perspective and simultaneously demonstrated spatial nonstationarity. Moreover, the specific findings about the influence of each built environment factor facilitate a deeper insight into dynamic population distribution and its determinants.

Changes in oscillatory and nonlinear dynamic processes of microcirculation in patients with obliterating atherosclerosis of lower limb arteries after revascularization

Aim: To study the nature of changes in oscillatory and nonlinear dynamic processes in the skin microcirculatory system by laser Doppler flowmetry in patients with obliterating atherosclerosis of the lower limbs arteries (OALLA) after limb revascularization.Material and Methods. 27 male patients with OALLA before and after endovascular revascularization of the affected limb (median age 63.0 [60.0; 69.0] years) were studied. Microcirculation (MC) of the foot skin with assessment of nonlinear dynamic processes and spectral wavelet analysis of blood flow fluctuations was studied by laser Doppler flowmetry. The normalized amplitude indices of blood flow fluctuations were determined in frequency ranges reflecting: endothelial, neurogenic, myogenic, respiratory, pulse factors of hemocirculation. Bypass parameters and nutritive blood flow were assessed. An occlusion test was performed to determine capillary blood flow reserve. The study of nonlinear dynamic processes included assessment of fractal dimension, entropy determination and phase portrait analysis.Results. Limb revascularization in patients with OALLA resulted in improvement of the clinical picture accompanied by statistically significant increase in nutritive blood flow (+9.7%) and reserved dilatation potential of microvessels (+43.2%), decrease in arteriolo-venular blood shunting (–5.0%) and venous plethora (–14.3%). The analysis of nonlinear dynamic processes of the MC showed that after angioplasty, along with the remaining deficit of oscillatory processes energy, there was a decrease in the fractal dimension index (–14.3%), indicating the limitation of lability of the functional system of the microvascular bed. At the same time, an increase in the chaotization of the regulatory mechanisms of the peripheral blood flow was established.Conclusions. The results showed positive functional changes of the MC system associated with the improved clinical picture in patients with OALLA after limb revascularization. At the same time, changes in the nonlinear dynamics parameters indicate a compensatory increase in the chaotization of the system together with the remaining limitation of its functional lability and the energy deficit of oscillatory processes.

Renal ischemia-reperfusion injury in rabbits evaluated with quantitative susceptibility mapping: an animal study.

There were no effective noninvasive methods to diagnose renal ischemia-reperfusion injury (IRI), which is a major clinical problem. The objective of this study was to explore the feasibility of the quantitative susceptibility mapping (QSM) technique in evaluating the dynamic changes in the renal IRI process. A total of 36 New Zealand rabbits were randomly assigned to the IRI group (n=30) and the sham group (n=6). All rabbits underwent magnetic resonance imaging (MRI) examination, including T2-weighted imaging and QSM before the operation (pre-IRI) and 1, 12, 24, and 48 h after the operation (IRI-1h, IRI-12h, IRI-24h, and IRI-48h, respectively). Regions of interest were manually delineated in the outer medulla. All specimens were stained with hematoxylin and eosin (HE) and glutathione peroxidase 4 (GPX4). The pathological score of renal injury and the average optical density value of GPX4 were calculated. The repeated measurement analysis of variance (ANOVA) and Spearman correlation analysis were used to compare the differences between the susceptibility values and determine the correlation. In the IRI group, the susceptibility values of the outer medulla at the pre-IRI, IRI-1h, IRI-12h, IRI-24h, and IRI-48h time points were (42.83±7.83)×10-3, (-5.33±6.28)×10-3, (6.50±3.94)×10-3, (12.00±3.74)×10-3, and (22.00±6.81)×10-3 ppm, respectively. The susceptibility values significantly differed among the different time points (P<0.001). The susceptibility values had a negative correlation with the scores of cell edema (ρ=-0.61; P=0.002) and the average optical density value of GPX4 (ρ=-0.70; P<0.001). The susceptibility values had a positive correlation with iron content (ρ=0.79; P<0.001), the scores of cell necrosis (ρ=0.71; P<0.001), interstitial inflammation (ρ=0.60; P=0.002), cast (ρ=0.75; P<0.001), and the total pathological score of renal injury (ρ=0.51; P=0.01). QSM can be used as a noninvasive method to assess the dynamic changes of the outer medulla in the early stage of renal IRI in rabbits.

Effects of microstructure on the retention of proton conductivity of Nafion/SiO2 composite membranes at elevated temperatures:An in situ SAXS study

The operating temperature of modified Nafion membranes remains too low to satisfy the requirements for high-temperature proton exchange membrane fuel cells (HT-PEMFCs) because most can only operate well below 120 °C. In this article, we prepare a series of Nafion/SiO2 composite membranes with different contents of doped silica nanoparticles by in situ growth of SiO2 nanoparticles near the –SO3H group. The water dynamic change process and the functional properties of Nafion/SiO2 composite membranes are studied and found to correlate well with structural parameters, such as crystallinity and average chain spacing. Also, microstructure information including the phase separation structure changes, structural complexity, and ion cluster fraction of Nafion/SiO2 composite membranes at different temperatures are investigated using synchrotron-based in situ small angle X-ray scattering (SAXS). Differing from expectations, the amount of water in the Nafion/SiO2 composite membranes may not be the decisive factor to maintain proton conductivity at relatively high temperatures. Instead, the complexity or connectivity of the proton transport channel may play a more important role in the effective proton transfer inside the composite membranes, which also provides valuable guidance and insight for the development of novel HT-PEM materials with well-designed ion transport pathways in the future.

A universal grain‐size distribution of soil with scaling invariance

AbstractSoils are composed of wide‐ranged grains and grain size distribution (GSD) is the fundamental characteristic determining the physical and hydraulic properties. Previously we have proposed a GSD function for various soils. However, the remarkable discrepancy in the distribution occurs in some soils, which not only limits the applicability of the function but also raises doubt as to the possibility of a universal GSD function. In this study we modify the GSD function to a general form of P(D) ~ D−μexp(−D/Dc)n, which introduces a new exponent n for the grain size scale. It turns out that this modification has eliminated the discrepancies and universally applies to a great variety of soils from around the world (hence to be a universal GSD function, UGSD). The exponent n is proved to be a scaling factor of grain size in log‐scale and divides soils into three categories of n &lt; 1 n &gt; 1, and n = 1. Furthermore, soils of surface processes (e.g., erosion, tillage, desertification, landslides, avalanches, deposition, and sediment transportation) remain in the same category and preserve the UGSD function. Thus, the UGSD not only provides parameters μ and Dc as synthetic indices for soil properties (e.g., as indices for spatial heterogeneity or variables for pedotransfer functions), but also describes texture changes in dynamic processes. The UGSD function represents a ‘conservative law’ underlying soil genesis and processes, which fills the knowledge gaps related to the lack of universally applicable indices for soil properties, and thus has universal applications in soil classification, spatial variability, as well as dynamical processes.

High Performance Graphene-C60 -Bismuth Telluride-C60 -Graphene Nanometer Thin Film Phototransistor with Adjustable Positive and Negative Responses.

Graphene is a promising candidate for the next-generation infrared array image sensors at room temperature due to its high mobility, tunable energy band, wide band absorption, and compatibility with complementary metal oxide semiconductor process. However, it is difficult to simultaneously obtain ultrafast response time and ultrahigh responsivity, which limits the further improvement of graphene photoconductive devices. Here, a novel graphene/C60 /bismuth telluride/C60 /graphene vertical heterojunction phototransistor is proposed. The response spectral range covers 400-1800nm; the responsivity peak is 106 A W-1 ; and the peak detection rate and peak response speed reach 1014 Jones and 250 µs, respectively. In addition, the regulation of positive and negative photocurrents at a gate voltage is characterized and the ionization process in impurities of the designed phototransistor at a low temperature is analyzed. Tunable bidirectional response provides a new degree of freedom for phototransistors' signal resolution. The analysis of the dynamic change process of impurity energy level is conducted to improve the device's performance. From the perspective of manufacturing process, the ultrathin phototransistor (20-30nm) is compatible with functional metasurface to realize wavelength or polarization selection, making it possible to achieve large-scale production of integrated spectrometer or polarization imaging sensor by nanoimprinting process.

Myanmar's Land Cover Change and Its Driving Factors during 2000-2020.

Land use/cover change (LUCC) research occupies an important place in the study of global change. It is important for the ecological protection and long-term development of a place. Current research is lacking in the study of dynamic changes at the national level in Myanmar over long time periods and sequences. Quantitative research on the driving factors of LUCC is also lacking. This paper uses the GLC_FCS30 (Global Land-Cover product with Fine Classification System) dataset and socio-economic statistical data in Myanmar to conduct the study. The dynamic change process of LUC (land use/cover) was investigated using the land use dynamic degree, land use transfer matrix, and Sankey diagram. Principal component analysis was used to derive the main drivers of LUCC. The drivers were quantified using multiple linear stepwise regression analysis and specific factors were analyzed. The spatial scope of the study is Myanmar, and the temporal scope is 2000-2020. Results: (1) In 2020, the spatial distribution of LUC in Myanmar shows predominantly forests and croplands. Forests account for 56.64% of the country's total area. Agricultural land accounts for 25.59% of the country's total area. (2) Over the time scale of the study, the trend of LUCC in Myanmar showed significant shrinkage of evergreen broad-leaved forest and deciduous broad-leaved forest (a total shrinkage of -3.34 × 104 km2) and expansion of the other land types. (3) Over the time scale of the study, the dynamic changes in LUCC in Myanmar most occurred as an interconversion between two land types, such as between cropland and deciduous broad-leaved forest, evergreen broad-leaved forest and shrubland, deciduous broad-leaved forest and shrubland, evergreen broad-leaved forest and evergreen needle-leaved forest, and evergreen broad-leaved forest and deciduous broad-leaved forest. (4) The dynamics of LUC in Myanmar is mainly influenced by the socio-economic level of the country. Among them, the impact of agricultural level is the most obvious. Specifically, Myanmar's LUCC is mainly driven by urban population, urbanization rate, industrial value added, food production, and total population. Our research will enable the Myanmar government to make more scientific and rational land management and planning and to make more informed decisions. After understanding the basic situation of LUCC in Myanmar, the hydrological effects, biodiversity changes, and ecological service function changes due to land change in the region can be explored. This is the direction of future research.

Levels of Decision-Making Determinants in the European Council of the EU in 2010–2022

The European Union has been recognised as an international system whose decisions and actions are conditioned by environmental determinants, which is a dynamic process of change. The article attempts to explain the EU’s decisions based on the conclusions of the European Council in 2010–2022. 93 documents containing the conclusions of the European Council adopted during that period were analysed. It was found that the determinants of EU decisions and actions function – firstly – at the international system level and, secondly, at the level of the domestic systems of the Member States. In addition, the article: 1) reconstructed the discussion in the science of international relations on behavioural determinants, 2) reconstructed the perception of determinants in the conclusions of the European Council; 3) a model for organising the analysis of the determinants of the decisions of the European Council was proposed.

Improving Nonlinear Model Predictive Control Laws via Implicit Q-Learning

This paper presents an implicit Q-Learning scheme to improve the performance of nonlinear model predictive control laws while providing a stability guarantee. The control space of this learning-based method is restricted to the admissible control set of a Lyapunov-based nonlinear model predictive controller. The effectiveness of this method is demonstrated on a highly nonlinear chemical process system with practical significance. It is shown that learning-based controller derived with this method improves the performance of a sub-optimal baseline controller beyond what is possible by supervised learning approximation approaches. This scheme offers a promising new paradigm for improving model-based controllers that deteriorate due to the dynamic process changes typically encountered in real-world systems.

Transformation of the higher education system: Current and emerging global trends

In the context of unfolding global processes of the post-industrialization, informatization and the growth of knowledge components of economic development, the higher education system as an element of the economic and cultural compound of the countries and states acts as a moderating medium between all socio-economic subsystems of modern society. With the impact of global processes, the national higher education system assesses and neutralizes global risks, where it is possible, and creates sustainable trends of their effective adaptation. Regardless of the devotion level of the regional educational system and regardless of the priorities of the state educational system, it is impossible to exclude diffusion of the trends, tendencies and the global technologies. That is why, for the higher education systems of countries, the transformation of higher education systems in these conditions involves the adoption of a special model of such transformation – converged, which allows to identify the most dynamic, effective and relevant processes of change and to detect on this basis the main objectives of transformation and mechanisms for its implementation. With the expansion of information and technological processes in the society and in the aspect of the increasing restrictions of social mobility, the higher education takes on new meanings and new significance. In a globalized environment, the transformation of the autonomous higher education systems implicates the adoption of the specific model of transformation – the converged one. From these perspectives, the appreciation of the impact of global trends and tendencies to the transformation of stable patterns and links between the higher education economy seems to be a promising subject of research.

Violence and posttraumatic change (PTC).

The purpose of this study was to explore the ways in which Canadian victims and survivors of violent crime describe and make sense of their posttraumatic experience(s). This qualitative study drew on open-ended responses from a mixed methods online survey with Canadian victims and survivors of violent crime (N = 435). Participants in the online survey identified as women (n = 335), men (n = 95), or two-spirit, nonbinary, or gender queer (n = 5); and had experienced partner violence (35%, n = 154), sexual violence (32%, n = 141), homicide or other violent death of a family member (22%, n = 96); or other types of violence (10%, n = 44). Additionally, in-depth narrative interviews were completed with a subsample of survey participants (n = 71). Analyses resulted in multiple themes organized into three broad categories: (a) negative posttraumatic changes, (b) positive posttraumatic changes, and (c) resistance to the language of posttraumatic growth. Results suggest the importance of approaching the posttraumatic experience with a focus on perceptions of change rather than growth. The concept of "posttraumatic change" is more responsive to the dynamic process of change that victims and survivors of violence experience, which is often difficult to frame with language focused exclusively on stress or growth. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Macro-Structural Change in Relation to Micro-Discursive Storytelling: Qatari Nationality as a Resource for the Construction of Professional Identity

Combining insights from the sociology of education and from discourse-based work on identities within contexts of organizational change, we aim to tease out how topdown structural changes can be related to micro-discursive identity work. Selecting the case of the Qatari university context – which currently takes up a pivotal position in a nation-wide transformative agenda that targets both society and economy – we engage in an empirical investigation of a corpus of interviews with Qatari junior academics. We draw on ‘positioning analysis’ (Bamberg, 1997) to scrutinize the linguistic specificities of the interviewees’ individual stories and their construction of professional identities. In the analyses, we show an emergent pattern of similar identity work in some of the interviewsin our dataset. In particular, these interviewees explicitly draw on their nationality when discussing their career journeys, thus constructing a very specific version of their professional identity. We argue that this can be considered as emblematic of the academic profession as it is being shaped in current-day Qatar, and we claim that this type of analysis can reflexively capture some of the complexities of the dynamic change processes in higher education institutions as well as in organizational contexts in general.

Analysis of grain tribology and improved grinding temperature model based on discrete heat source

A high grinding temperature will cause thermal damage to a workpiece surface and deterioration of surface integrity, which is the bottleneck of grinding. The present grinding temperature theoretical model is based on grain homogeneity and the continuous heat source distribution in the grinding zone. However, the random change in interference between the effective grains and a workpiece during the machining process causes a change in the grain tribological properties, resulting in varying transient grinding temperatures. Based on the current situation, the grain tribological mechanism and an improved temperature model based on a discrete heat source are proposed to reveal the temperature variation law of a workpiece in an actual grinding process. First, the surface topography model of a grinding wheel is established based on the geometric characteristics of grains, and the determination mechanism of effective grains is revealed. Furthermore, the interference mechanical behavior of the grains and workpiece is analyzed according to the kinematic law of grains in the sliding, plowing, and cutting stages. The mechanical model and specific grinding energy model at different stages are established, and the thermal distribution mechanism of effective grains is revealed. Finally, a temperature field mathematical model of a discrete heat source is established, and numerical simulation is performed to demonstrate the dynamic temperature change process of different grains. A new experimental method for measuring temperature at different positions of the workpiece with a bipolar thermocouple array is designed, and a regional numerical simulation and experimental temperature comparison method is innovatively proposed. Experimental results show that the grinding temperature measured under different cutting depth conditions is in good agreement with the numerical results, and the variation law is consistent. The minimum error in 64 groups of experimental measuring and numerical calculation comparison zones can reach 4.9%, and the proportion of zones with errors less than 10% can approach 86%. This study will provide a theoretical basis for the accurate suppression of workpiece surface thermal damage and the development of precision grinding in engineering discipline and machinery industry.

Dynamic analysis of epileptic causal brain networks based on directional transfer function

Epilepsy is a neurological disease with disordered brain network connectivity. It is important to analyze the brain network mechanism of epileptic seizure from the perspective of directed functional connectivity. In this paper, causal brain networks were constructed for different sub-bands of epileptic electroencephalogram (EEG) signals in interictal, preictal and ictal phases by directional transfer function method, and the information transmission pathway and dynamic change process of brain network under different conditions were analyzed. Finally, the dynamic changes of characteristic attributes of brain networks with different rhythms were analyzed. The results show that the topology of brain network changes from stochastic network to rule network during the three stage and the node connections of the whole brain network show a trend of gradual decline. The number of pathway connections between internal nodes of frontal, temporal and occipital regions increase. There are a lot of hub nodes with information outflow in the lesion region. The global efficiency in ictal stage of α, β and γ waves are significantly higher than in the interictal and the preictal stage. The clustering coefficients in preictal stage are higher than in the ictal stage and the clustering coefficients in ictal stage are higher than in the interictal stage. The clustering coefficients of frontal, temporal and parietal lobes are significantly increased. The results of this study indicate that the topological structure and characteristic properties of epileptic causal brain network can reflect the dynamic process of epileptic seizures. In the future, this study has important research value in the localization of epileptic focus and prediction of epileptic seizure.

Deduction of sudden rainstorm scenarios: integrating decision makers' emotions, dynamic Bayesian network and DS evidence theory

Event scenarios serve as the basis for emergency decision making after sudden disasters, and the accuracy of scenario deduction directly determines the effectiveness of emergency management implementation. On July 20, 2021, an exceptionally heavy rainstorm disaster occurred in Zhengzhou, Henan Province, China, causing serious urban waterlogging, river floods, flash floods and landslides and resulting in major casualties and property losses:14.79 million people affected, 398 people killed or missing (380 people in Zhengzhou) and a direct economic loss of 120.06 billion RMB. In order to investigate the complex evolution process of this disaster, a dynamic Bayesian network, evidence theory and emotion update mechanism are integrated to develop an efficient and effective scenario deduction model, with an emphasis on combining subjective and objective factors. In this model, more attention is given to subjective factors such as decision makers' emotions. The elements of scenario deduction are classified into the situation status, meteorological factor, emergency activities, decision makers' emotions and emergency goals, the coupling relationship between the elements are comprehensively analyzed, and the influence of these elements on the evolution mechanism of the rainstorm disaster is investigated, so as to facilitate targeted emergency management measures for the rescue operations. The empirical results show that the proposed dynamic Bayesian network can effectively simulate the dynamic change process of scenario deduction, the improved Dempster–Shafer evidence theory can reduce the subjectivity of the model in dealing with the uncertainty of the evolution process, and the emotion update mechanism can adequately quantify and decrease the influence caused by the emotional changes of decision makers. The model may better replicate actual events, and it may apply to the scenario deduction of other disasters, making an impact on the study of sudden catastrophes.

Design of extended Kalman filter observer coupled to ammonia cross-sensitivity model for an SCR system

Commercial diesel vehicles that comply the China/EURO VI emission regulations are generally equipped with selective catalytic reduction (SCR) systems for reducing [Formula: see text] emission and [Formula: see text] sensors at its downstream for accurate closed-loop control. However, [Formula: see text] sensors have significant ammonia cross-sensitivity pushing up their readings. Moreover, for the closed-loop control of SCR systems effectively estimating the critical states from the [Formula: see text] sensor readings remains a further challenge. In this paper, an ammonia cross-sensitivity model with segmented sin and quadratic composite functions describing high frequency characteristics is established by analyzing the experimental data of an SCR system. A control-oriented three-states model of an SCR system is established, and based on it an extended Kalman filter (EKF) observer coupled to the ammonia cross-sensitivity model is proposed. The simulation results show that from the [Formula: see text] sensor readings the EKF observer can effectively estimate the deterioration trend of the [Formula: see text] and [Formula: see text] emissions, and describe the dynamic change process of the ammonia coverage rate. The experimental results under the four non-excitation cycles show that the EKF observer can effectively estimate the deterioration trend, that the average estimated accuracy of [Formula: see text] and [Formula: see text] during their deterioration stage can respectively reach 86.16% and 54.87%, and that the observer has better robustness to disturbances from the operating conditions.

A novel water use efficiency model based on stomata coupling crop growth and farmland water cycle processes in arid area

Water use efficiency (WUE) determined by water-carbon coupling process is important to evaluate the relationship between crop growth and water consumption. Aiming to provide a novel WUE dynamic evaluating method at field scale, we developed a crop WUE model based on stomata, which coupled the processes of crop growth and farmland water cycle. In previous work, we developed a stomatal conductance model in which crop stomatal conductance could be described by its relationship to meteorological factors, soil water and salinity. In this study, we coupled crop transpiration and photosynthesis based on stomata. Furthermore, the model described the daily crop growth and hydrological processes. As a result, the developed model could simulate the dynamic changes of crop canopy evapotranspiration (ET), canopy photosynthesis, dry matter accumulation and assimilation distribution, soil water movement, soil salt transport and WUE of farmland ecosystems on a daily scale. Three years field experimental data were used to calibrate the developed model. The results showed that the model could simulate the variation of agricultural hydrology processes properly in sunflower field on the daily scale, with determination coefficient (R2) and Nash-Sutcliffe efficiency coefficient (NSE) of ET, transpiration and WUE all close to 0.60. R2 and NSE of net ecosystem productivity above 0.74 and 0.68, respectively. And the coupling model had a good performance in simulating the dynamic change process of soil moisture and salt with the R2 and NSE above 0.71 and 0.61, respectively. Sensitivity analysis of model parameters showed that the selection of the extinction coefficient had a great influence on the accuracy of the model and the accurate description of soil resistance parameters played a crucial role in the accurate quantification of ET. The developed field WUE model can provide novel method to evaluate daily hydrological processes, agricultural productivity and WUE dynamics.

Realizing common prosperity: The action logic of social entrepreneurship community mobilization in rural tourism

The effective participation of rural residents in tourism social entrepreneurship can improve their quality of life and promote community transformation. Hence, it is important to understand the strategies and process of community mobilization by social entrepreneurs. This study focuses on the strategy of village cadre, who play the dual roles of an entrepreneur and a policy implementer to mobilize community residents to participate in collective tourism entrepreneurship and the mechanism for changing residents’ attitudes in a rural China context, by using the longitudinal research method of nonparticipatory observation and 50 interviews conducted in Yuanjia Village, Shaanxi Province. The results show that the community mobilization of social entrepreneurs has not been accomplished overnight but has undergone a 3-stage dynamic process of change. These results indicate that social enterprises should incorporate indigenous people into their value network in the early stage of tourism development and continue to explore the mechanism of affiliating residents with benefits, so as to further increase residents’ in-depth participation. Residents play the dual roles of producer and collaborator in tourism social entrepreneurship and work with social entrepreneurs to promote the sustainable development of rural tourism and achieve common prosperity.

Effect of Aeration on Blockage Regularity and Microbial Diversity of Blockage Substance in Drip Irrigation Emitter

Aerated drip irrigation is rendered as a new water-saving irrigation method based on drip irrigation technology, which is endowed with the function of effectively alleviating the problem of rhizosphere hypoxia in crop soil, enhancing the utilization rate of water and fertilizer; as a result, it improves the harvest and quality of crops. However, clogged emitters are important indexes, among others, that pose an influence to the service effect and life duration of drip irrigation systems. At present, the working principle and mechanism of the influence of air feeding on the blockage of drip irrigation emitters remain unclear. Therefore, based on the two gas filling methods of the micro/nano bubble generator and Venturi injector, the dynamic change process for the average flow ratio of an air-filled drip irrigation emitter was studied by the method of emitter plugging test. 16S rRNA sequencing was used to analyze the microbial diversity of the emitter plugs. The results show that the air injection can pose influence on the clogging procedure of drip irrigation emitters, and more importantly, it makes the distribution of blocked emitters more uniform, thus improving the uniformity of the system. Different filling methods have different effects on the blockage of the emitter. Among them, the blockage time of drip irrigation system under the micro/nano aerated drip irrigation (MAI) mode is 5.73 times longer than that under unaerated drip irrigation (UVI), and similarly, Venturi gas drip irrigation (VAI) is close to that under UVI. The filling method changed the microbial diversity of the blockage in the emitter. Among them, the number of operational taxonomic unit (OTU) unique to MAI was 2.1 times that of UVI, and the number of OTU unique to VAI was 1.3 times that of UVI. Meanwhile, gas addition will inhibit the growth of Nitrospirae and Proteobacteria microbial communities and promote the growth of Firmicutes and Actinobacteria microbial communities. Furthermore, the increase in microbial extracellular polymer in the plugging material of the emitter was inhibited and the plugging process of the emitter was slowed down. The research results are of great significance in the disclosure of the clogging mechanism of drip irrigation emitter and constructing the green, anti-blockage technology of aerated drip irrigation.

Dynamic Process of Structural Change in Graphene Irradiated by Swift Heavy Ions

Dynamic Process of Structural Change in Graphene Irradiated by Swift Heavy Ions